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He, Fenjin. "Substrate Concentration, Calcium Concentration and κ-Casein Hydrolysis in Milk Coagulation". DigitalCommons@USU, 1990. https://digitalcommons.usu.edu/etd/5364.
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Milk coagulation consists of four overlapping phases: enzymic hydrolysis, micelle aggregation, gelation and syneresis. The objectives of this study were to determine the effects of added CaCl2 on milk coagulation and the relationship between enzymic hydrolysis and micelle aggregation with substrate at different concentrations.
Addition of CaCl2 to milk is widely practiced in industry and in laboratories. This changes calcium concentration, pH and ionic strength. It is impossible to separate these three variables and investigate each one independently.
Addition of low levels of CaCl2 shortens coagulation time and increases curd firming rate. Low levels of CaCl2 also accelerate the enzymic hydrolysis process. Calcium ions increase hydrolysis rate, but this effect is much smaller than that of lowered pH. Increase of ionic strength due to addition of CaCl2 has an adverse effect on enzymic hydrolysis. This dominates at high CaCl2 concentration, and the overall coagulation process slows down. Adding CaCl2 also promotes micelle aggregation. However, aggregation is retarded by high levels of added CaCl2.
Results of this study show that about 90% of the κ-casein is hydrolyzed for diluted milk (1/3) to coagulate. Samples at normal concentration (12 g NDM/100 ml solution) require only 60% conversion of κ-casein to para-κ-casein. Addition of CaCl2 significantly decreases this percentage. This suggests a different aggregation and gelation process in samples containing added CaCl2
When pepstatin A is used to stop enzymic hydrolysis at different times, different degrees of κ-casein conversion are obtained. Micelles aggregate even at very low percentages of hydrolysis. Previous reports have stated that a micelle cannot participate in aggregation until almost all of its κ-caseins have been hydrolyzed.
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Vatansever, Aysun. "Bioflocculation Of Activated Sludge In Relation To Calcium Ion Concentration." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606304/index.pdf.
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Bioflocculation, which can be defined as aggregation of bacterial flocs, has important implications on the physical characteristics of sludge. It is especially critical to settling and dewatering systems which impacts the overall economy of the process greatly. One of the most common problems in activated sludge systems to negatively influence the settleability is sludge bulking which can be defined as non-settling situation of microbial mass.
The first objective of this research is to investigate the effect of calcium ion on sludge bulking in a phosphorus deficient medium and the second objective is to improve the settling, dewatering, and pumping of activated sludge by adjusting the calcium (Ca) ion concentration of the feed. For this purpose, 7 semi-continuous laboratory scale activated sludge reactors were operated with a mixed aerobic culture. The reactors had 8 days of sludge residence time and aerated with air pumps to provide a dissolved oxygen concentration of at least 3 mg/L. All the analyses were conducted after the reactors reached steady state condition.
In the first part of the research, the effect of strictly phosphorus-limited medium on bulking of activated sludge was studied at different calcium ion concentration. Three reactors were set up having 5, 10 and 20 meq/L calcium concentrations. From the results it was observed that, phosphorus deficiency caused viscous bulking independent from the calcium ion concentration. It was found out that bulking of activated sludges due to phosphorus deficiency could be cured by the addition of phosphorus. Furhermore, microorganisms starved for phosphorus, seemed to accumulate polyphosphate granules when they were exposed to a phosphorus source.
In the second part of the study, the effect of calcium ion on physical, chemical and surface chemical properties of activated sludge was investigated at 4 different concentrations (0.27, 5, 10 and 20 meq/L) under sufficient phosphorus concentration. Calcium addition resulted in significant changes in the quantity and quality of extracellular polymeric substances (EPS). Total EPS increased depending on the calcium concentration. Carbohydrate content of EPS dominated over the protein content for calcium concentration of 5 meq/L and above. The amount of calcium ions incorporated into the sludge floc matrix also increased with the dose of calcium added. Settleability and dewaterability of sludge improved significantly at 5 meq/L dose of calcium. However, settleability did not change any further with increasing calcium dose, whereas dewaterability increased for all increasing calcium concentrations. Sludge viscosity also decreased considerably at 5 meq/L concentration indicating better pumpability but it did not change further above 10 meq/L calcium addition.
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MacMillan, Debbi. "Role of the sarcoplasmic reticulum in nitric oxide induced modulation of cytoplasmic calcium in rabbit aortic smooth muscle cells." Thesis, University of Strathclyde, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248585.
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Price, Edmund E. 1954. "Response of Freshwater and Saltwater Toxicity Test Species to Calcium and Salinity Concentrations Encountered in Toxicity Tests." Thesis, University of North Texas, 1989. https://digital.library.unt.edu/ark:/67531/metadc331168/.
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The responses of freshwater (Daphnia magna. Pimephales promelas) and saltwater (Mysidopsis bahia. Cyprinodon variegatus) toxicity test species to elevated calcium concentrations and changing salinity conditions were investigated. The use of salinity as a criterion for selection between saltwater and freshwater test species was investigated by conducting both calcium and salinity toxicity tests.
Salinity was determined to be an inappropriate criterion under conditions encountered in this study.
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Clarke, Sonia Dawn. "Design and synthesis of novel spectroscopic indicators of cystosolic free calcium concentration." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335750.
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Wilsdorf, Robert Ernst. "Evaluating the seasonal changes in calcium concentration and distribution in apple fruit after application of different calcium fertilisation strategies." Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/17790.
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Thesis (MScAgric)--Stellenbosch University, 2011.<br>ENGLISH ABSTRACT: Localized calcium (Ca) deficiencies frequently develop independent from total Ca supply and total fruit Ca concentration. Bulk mineral analyses is therefore not completely suitable for determination of the susceptibility of fruit in developing Ca-linked fruit physiological disorders like bitter pit, as it supplies insufficient information regarding the spatial accumulation of Ca within the fruit. Additional Ca is applied either as soil or foliar applications, where soil applications are applied either after fruit set (pre-harvest) or in the period after harvest. The contribution of these different methods of Ca application to the total Ca concentration in "Braeburn" fruit was quantified over three consecutive growing seasons. Foliar applications have been proven to be successful in suppressing bitter pit development and improving the Ca status of the fruit. The effectiveness of different formulations of foliar Ca products in influencing these parameters was also determined. Furthermore, the distribution pattern of fruit Ca resulting from different application strategies was mapped using particle induced X-ray emission technology.
In the "Braeburn" trial, mineral analyses indicated no significant differences between treatments in terms of Ca concentration at 80 days after full bloom (dafb). However, when soil applications occurred with active root growth (visually monitored), treatments differed significantly 80 dafb. Weekly foliar Ca applications from 28 dafb resulted in higher fruit Ca concentrations 80 dafb than a pre-harvest soil Ca application (January, 2010). A possible explanation for the inefficiency of pre-harvest soil Ca is the disintegration of xylem vessels from 40 dafb (before root uptake) for sensitive cultivars such as Braeburn. Bitter pit initiation has been shown to occur in the earlier part of the season. This, together with a reduced Ca supply to the fruit early in the season due to xylem disintegration (for sensitive cultivars), indicates the importance of early season foliar Ca applications. PIXE analyses were used to establish the radial Ca distribution in apples. Ca was concentrated in the skin and core, with very low values in the outer cortex. PIXE results indicated fruit Ca concentrations to be the lowest in the pre-harvest soil application treatment. This was in agreement with mineral analyses results. Ca enriched areas resulting from effective Ca delivery via the vascular bundles, had a profound effect on fruit Ca concentrations in the immediate core and cortex. At harvest, this effect was much more subtle and emphasizes the importance of untimely xylem rupturing on eventual fruit Ca concentration. At 80 dafb, treatments where foliar Ca was applied showed higher Ca concentrations in the outer cortex (where symptoms of bitter pit typically occur).
Calflo™ fruit had significantly higher Ca concentrations in "Braeburn" compared to fruits from Foliar GS™ and GG™ treatments. Calflo™ and Calcimax™ had a higher active Ca percentage (12%) compared to Foliar GSTM and GGTM (10%). Adding the Lecithin™ (surfactant) to Calcimax™ is not recommended as it did not improve its uptake.
In "Golden Delicious", the commercial spray program of seven, weekly foliar applications (Calcinit™) resulted in fruit with significantly higher Ca concentrations compared to other treatments.<br>AFRIKAANSE OPSOMMING: Kalsium (Ca) tekorte ontstaan gewoonlik in gelokaliseerde areas in die appelvrug en ontwikkel dikwels ten spyte van voldoende totale vrug Ca. Minerale analises van heel vrugte verskaf dus nie genoeg inligting aangaande die verspreiding van Ca in die vrug wanneer die ontwikkelling van fisiologiese defekte soos bitterpit ter sprake is nie. Addisionele Ca word gewoonlik aangewend as blaar- of grondtoedienings, waar grondtoedienings tipies voor-oes (net na set) of in die na-oes periode, toegedien word. Die bydraes van die verskillende toedieningsmetodes tot die totale Ca konsentrasie van "Braeburn" appels is geëvalueer oor drie agtereenvolgende seisoene. Blaartoedienings van Ca word algemeen gebruik om die voorkoms van bitterpit te beheer en die Ca konsentrasie van die vrug te verhoog. Die effektiwiteit van `n reeks blaartoedienings-produkte om hierdie faktore te verbeter, is ook ondersoek. Die spesifieke verspreiding van die Ca in die vrug is gekarteer na gelang van elke toediening deur middel van PIXE-analises (Particle induced X-ray emission).
In die "Braeburn" proef was daar geen beduidende verskille in terme van vrug Ca konsentrasie op 80 dnvb (dae na volblom) nie. Daarteenoor, was daar wel beduidende verskille by 80 dnvb toe grond toedienings saam met aktiewe wortelgroei geskied het (visuele inspeksie). Weeklikse blaartoedienings vanaf 21 dnvb het gelei tot vrugte met betekenisvol hoër Ca konsentrasies as die behandeling waar grondtoedienings slegs voor-oes geskied het (Januarie 2010). `n Moontlike oorsaak vir die oneffektiwiteit van voor-oes grondtoedings is die vroeë disintigrasie van xileem vesels in die vrug (soms voor 40 dnvb en voor die aanvang van wortelopname) in sensitiewe kultivars soos "Braeburn". Hierdie vroeë inhibering van Ca voorsiening, tesame met die vroeë inisiasie van bitterpit, beklemtoon die belangrikheid van blaarbespuitings vroeg in die seisoen. Die PIXE-analises wat aangewend is om die radiale verspreiding van Ca in die vrug te bepaal het getoon dat Ca meestal in die skil en kern van die vrug gekonsentreer was, met baie lae konsentrasies in die buitenste korteks. Die laagste Ca konsentrasies is waargeneem in vrugte van die behandeling waar voor-oes Ca slegs as `n grondtoediening geskied het. Hierdie waarneming is in ooreenstemming met die mineraalanalise resultate. Ca verykte areas, afkomstig van die naby geleë vaatbundels (xileem vesels), het egter die grootste effek op vrug Ca konsentrasie gehad. Hierdie effek was nie so groot by oes nie en beklemtoon dus die belangrikheid van die funksionaliteit van die vaatbundels. Blaartoedienings kon die Ca konsentrasie in die buitenste korteks suksesvol verhoog - waar simptome van bitterpit tipies voorkom.
Die Calflo™ behandeling het beduidende hoër Ca konsentrasies gehad as die Foliar GS™ en GG™ behandelings. Die Calflo™ en Calcimax™ behandelings het `n hoër aktiewe Ca persentasie (12%) relatief tot die Foliar GS™ en GG™ (10%) behandelings bevat. Die byvoeging van Lecithin™ by Calcimax™ word nie aanbeveel nie, omdat dit geensins Ca opname vermeerder het nie.
In die "Golden Delicious" proef het die kommersiële behandeling (Sewe weeklikse spuite van Calcinit™) gelei tot vrugte met die hoogste Ca konsentrasie van al die behandelings.
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Efanov, Alexander. "Stimulation of insulin secretion independently from changes in cytosolic free Ca²⁺-concentration : studies with imidazolines and inositol polyphosphates /." Stockholm, 1999. http://diss.kib.ki.se/1999/91-628-3876-8/.
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Guérineau, Nathalie. "Diversité des modes de régulation de la concentration de calcium cytosolique dans les cellules endocrines de l'hypophyse antérieure." Bordeaux 2, 1992. http://www.theses.fr/1992BOR28211.
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Trafford, Andrew William. "Local and global measurements of intracellular calcium concentration during spontaneous and triggered propagating calcium waves in single rat ventricular myocytes." Thesis, University of Liverpool, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307663.
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Huang, Alice. "Calcium-sensing Receptor Mediated Control of CYP27B1 Promoter-dependent Gene & Protein Expression: Complex Extracellular Ca2+ Concentration Dependence." Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/20127.
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Changes in extracellular Ca2+ (Ca2+o) differentially modulate 25-hydroxyvitamin D3 1α-hydroxylase (1αOHase; encoded by CYP27B1) mRNA and protein levels in cell types including the renal proximal tubule (inhibitory), parathyroid, and skeletal osteoblasts (stimulatory) to control 1,25-dihydroxyvitamin D3 synthesis. We hypothesised that the calcium-sensing receptor (CaSR) mediated Ca2+o concentration-dependent control of 1αOHase, either directly through Ca2+o, or through the local production of parathyroid hormone related peptide (PTHrP). To investigate promoter activity, I transfected a firefly luciferase reporter gene under the control of the 1501 bp human CYP27B1 promoter into HEK-293 cells that stably expressed the CaSR (HEK-CaSR cells) and measured luciferase activities from cells exposed to various Ca2+o concentrations. CYP27B1 promoter-controlled luciferase expression exhibited a biphasic Ca2+o-dependent response in luciferase activity and protein that peaked with a 2-fold increase from basal levels at around 3.0 mM Ca2+o in HEK-CaSR cells. This response was absent in HEK-293 cells and was shifted to the left or right in the presence of the CaSR positive allosteric modulator, cinacalcet, or negative allosteric modulator, NPS-2143, respectively, indicating that both the stimulatory and inhibitory phases were CaSR-mediated. Firefly luciferase and 1αOHase mRNA levels obtained from quantitative RT-PCR exhibited a monophasic Ca2+o-dependent increase and suggests that the stimulatory phase arises from increased mRNA expression, whereas the inhibitory phase arises from reduced protein levels. Inhibitor and mutational studies suggested that the stimulatory phase was dependent on Gq/11 signalling, whereas the inhibitory phase requires MEK and PKC-dependent phosphorylation of the crucial T888 site of the CaSR's C-terminal tail.
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Lecoq, Xavier. "Etude de l'hydratation à concentration contrôlée du silicate tricalcique ca#3sio#5 et des caractéristiques de ses produits de réaction." Dijon, 1993. http://www.theses.fr/1993DIJOS063.
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Un dispositif expérimental a été élaboré pour maintenir constante, tout au long de l'hydratation du silicate tricalcique (C3s) en suspension diluée, la concentration en hydroxyde de calcium de la solution. Dans le domaine de concentration en hydroxyde de calcium de la solution étudiée, entre 6 et 36 mmol/l, les courbes d'avancement traduisent toutes une période de nucléation de l'hydrosilicate de calcium (c-s-h), une période de croissance individuelle des germes de c-s-h à la surface du c#3s (période accélérée) et une période d'épaississement de la couche de c-s-h recouvrant le c#3s (période décélérée). La cinétique de l'hydratation dépend essentiellement du nombre de germes initiaux de c-s-h précipites à partir des ions accumules en solution pendant la période de dissolution pure du c#3s et du mode de croissance des c-s-h. Il a été mis en évidence la formation, a partir du c#3s, de deux c-s-h de stœchiométrie et de structure différentes. L’un précipite pour 0<cao<22 mmol/l, l'autre pour 22<cao<36 mmol/l. La structure de l'un et de l'autre dérive de celle de la tobermorite. Leur formation se différencie par des modes de croissance différents se traduisant par des morphologies différentes.
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Groshong, Kimberly Ann. "Modeling the Effect of Calcium Concentration and Volumetric Flow Rate Changes on the Growth of Rimstone Dam Formations Due to Calcium Carbonate Precipitation." University of Akron / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=akron1220067458.
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Van, Hemelrijck Mieke, Karl Michaëlsson, Jakob Linseisen, and Sabine Rohrmann. "Calcium Intake and Serum Concentration in Relation to Risk of Cardiovascular Death in NHANES III." Uppsala universitet, Ortopedi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-199913.
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BACKGROUND: Evidence for an association between calcium intake and risk of cardiovascular death remains controversial. By assessing dietary intake, use of supplements, and serum levels of calcium, we aimed to disentangle this link in the third National Health and Nutrition Examination Survey (NHANES III). METHODS: Mortality linkage of NHANES III to death certificate data for those aged 17 years or older (n = 20,024) was used to estimate risk of overall cardiovascular death as well as death from ischemic heart disease (IHD), acute myocardial infarction (AMI), heart failure (HF), and cerebrovascular disease (CD) with multivariate Cox proportional hazards regression analysis. RESULTS: About 10.0% of the population died of cardiovascular disease and the majority (5.4%) died of IHD. There was increased risk of overall CVD death for those in the bottom 5% of serum calcium compared to those in the mid 90% (HR: 1.51 (95% CI: 1.03-2.22)). For women there was a statistically significant increased risk of IHD death for those with serum calcium levels in the top 5% compared to those in the mid 90% (HR: 1.72 (95%CI: 1.13-2.61)), whereas in men, low serum calcium was related to increased IHD mortality (HR: 2.32 (95% CI 1.14-3.01), Pinteraction: 0.306). No clear association with CVD death was observed for dietary or supplemental calcium intake. CONCLUSIONS: Calcium as assessed by serum concentrations is involved in cardiovascular health, though differential effects by sex may exist. No clear evidence was found for an association between dietary or supplementary intake of calcium and cardiovascular death.
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Helmlinger, Gabriel. "Effect of pulsatile flow on the intracellular free calcium concentration of cultured vascular endothelial cells." Diss., Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/16707.
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Mack, Peter J. (Peter Joseph) 1980. "Force-induced calcium concentration change and focal adhesion translocation : effects of force amplitude and frequency." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/27124.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.<br>Includes bibliographical references (p. 63-66).<br>Vascular endothelial cells rapidly sense and transduce external forces into biological signals through a process known as mechanotransduction. Numerous biological processes are involved in mechanotransduction, including calcium signaling and activation of focal adhesion sites, but little is known about how cells initially sense changes in the external mechanical environment. In order to examine the rapid mechanosensing thresholds involved with mechanotransduction, calcium concentration changes and focal adhesion site translocations were observed with fluorescent microscopy by labeling intracellular calcium with Fluo-3 calcium dye and by infecting cells with GFP-paxillin fusion proteins. Monitoring calcium concentration changes proved unreliable for determining mechanotransduction thresholds, while a non-graded, time dependent ([similar to] minutes) steady load threshold for mechanotransduction was established between 0.90 and 1.45 nN for focal adhesion site activation. Activation was greatest near the point of forcing (< 7.5 [mu]m), indicating that shear forces imposed on the apical cell membrane transmit non-uniformly to the basal cell surface and that focal adhesion sites may function as individual mechanosensors responding to local levels of force. Results from a while applying nN-level magnetic trap shear forces to the cell apex via integrin-linked magnetic beads. Both biological responses were monitored continuum, viscoelastic finite element model of magnetocytometry that represented experimental focal adhesion attachments provided support for a non-uniform force transmission to basal surface focal adhesion sites. Frequency variation between 0.1 and 50 Hz altered focal adhesion translocation and<br>(cont.) resulted in a biphasic response minimized at 1.0 Hz. Furthermore, applying the tyrosine kinase inhibitors genistein and PP2, a specific Src family kinase inhibitor, resulted in differential effects on force-induced translocation. These results highlight the mutual importance of force transmission and biochemical signaling in focal adhesion mechanotransduction.<br>by Peter J. Mack.<br>S.M.
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Berry, Jeffrey Nicholas. "Sulfate in foraminiferal calcium carbonate : investigating a potential proxy for sea water carbonate ion concentration." Thesis, Massachusetts Institute of Technology, 1988. http://hdl.handle.net/1721.1/53536.
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Thesis (M.S.)--Joint Program in Chemical Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 1988.<br>Includes bibliographical references (leaves 82-85).<br>The sulfur content of planktonic and benthic foraminifera was measured in specimens recovered from deep-sea sediment cores and individuals grown in culture. A new method for measuring sulfur in foraminiferal calcium carbonate was developed, employing a high-resolution inductively coupled plasma-mass spectrometer. The sulfur measurements, expressed as sulfur-to-calcium (S/Ca) ratios in the foraminiferal shells, ranged from 0.26 to 6.0 mmol/mol. Most analyses fell in the range of 0.7 to 2.5 mmol/mol. Culturing experiments were conducted in the planktonic foraminifer G. sacculifer to test the hypothesis that S/Ca ratios in the foraminifer are inversely proportional to the carbonate ion concentration in the seawater in which they grow, and hence proportional to the pH of the seawater. The slope of the relationship between cultured G. sacculifer S/Ca and the pH of the seawater medium was -1.92 mmol mol-1/pH unit with a least squares linear correlation coefficient, r2=0.927. The S/Ca ratios of planktonic and benthic foraminifera from Holocene and last glacial period sediments were measured in an effort to use the established relationship of S/Ca and pH to calculate the ocean pH gradient between Holocene and glacial time. The results indicate the pH of global ocean deepwater was 0.10 to 0.15 pH units higher during glacial time than today. Smaller pH gradients were seen for some cores which may have been caused by circulation-induced water mass changes. Surface ocean changes in pH over the Holocene-glacial interval seem to vary from region to region, with up to an 0.2 pH unit increase at the Sierra Leone Rise in glacial time. Benthic foraminifera from coretops in the thermocline of the Little Bahama Bank were analyzed for S/Ca to examine the effects of hydrographic variables on S/Ca. The relationship of S/Ca to pH and [CO3=] has a positive slope, at odds with the expected negative slope from the previous results. The S/Ca results do correlate well with salinity, suggesting that salinity or other hydrographic parameters may also influence foraminiferal S/Ca ratios.<br>by Jeffrey Nicholas Berry.<br>M.S.
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Francke, Eric Ivars. "Effect of oscillatory flow on the intracellular free calcium concentration of single cultured bovine aortic endothelial cells." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/16943.
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Grégoire, Guillaume. "Rôle du Reticulum sarcoplasmique dans la modulation de la concentration calcique cytosolique dans le myocyte de veine porte de rat." Bordeaux 2, 1995. http://www.theses.fr/1995BOR28358.
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Hauch, Kip D. "Measurement of platelet intracellular free calcium ion concentration by ratio fluorescence microscopy : a study of platelet activation induced by contact with biomaterials /." Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/9822.
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Chen, Ye. "Effects of selected transmitters on free cytosolic calcium concentration and pyruvate dehydrogenation in primary cultures of mouse astrocytes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1996. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq24053.pdf.
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Kake, Sandrine Aurélie. "Mesure de la concentration totale du calcium ([Ca[indice inférieur T]]MUSCLE) dans le muscle cardiaque et squelettique." Mémoire, Université de Sherbrooke, 2014. http://hdl.handle.net/11143/6316.
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La contraction du muscle cardiaque et squelettique est activée par la libération du calcium (Ca²[indice supérieur +]) du réticulum sarcoplasmique (RS), en réponse à la dépolarisation du sarcolemme pendant la propagation du potentiel d'action (PA) le long des tubules transverses (tubules T). Ce processus s'appelle le couplage excitation-contraction (couplage EC). Le couplage EC dans le muscle cardiaque est différent de celui squelettique en ce sens qu'il nécessite du Ca²[indice supérieur +] extracellulaire ce qui n'est pas le cas dans le couplage EC dans le muscle squelettique. Le but de mon projet de Maîtrise a été principalement de développer et de perfectionner une nouvelle méthode de mesure de la concentration totale de Ca²[indice supérieur +] dans le muscle cardiaque et le muscle squelettique ([Ca[indice inférieur T]]MUSCLE) de différentes espèces (rats, souris et grenouilles); dont la plus grande fraction est emmagasinée à l'intérieur du RS. Cette mesure quantitative a pour objectif à long terme, dans le cas du muscle cardiaque de comprendre les résultats apparemment contradictoires concernant le mécanisme principal de couplage EC et dans le cas du muscle squelettique, de confirmer que la concentration totale de Ca²[indice supérieur +] dans la préparation des cellules isolées correspond au niveau physiologique. De surcroît, dans ce dernier cas, la [Ca[indice inférieur T]]MUSCLE dans les fibres musculaires squelettiques de grenouille obtenu avec la technique de EGTA-Rouge de phénol effectué par Pape et al. (1995) est similaire à celle obtenue à partir de cette nouvelle méthode dans le muscle squelettique entier. Les résultats obtenus en relation avec le poids du muscle sur les souris C57BL6 montrent qu'il y a une grande dépendance du contenu total de Ca²[indice supérieur +] sur le poids du muscle. En effet, le poids du muscle varie de 12.7 mg à 5.2 mg ce qui correspond à 1.34 mM et 4.14 mM respectivement. Ces résultats suggèrent la possibilité d'un mécanisme pour la régulation du [Ca[indice inférieur T]]MUSCLE où le plus petit muscle augmente [Ca[indice inférieur T]]MUSCLE afin d'augmenter sa force spécifique (force normalisée pour la grandeur) pour produire une force similaire aux muscles plus grands. La calséquestrine est une protéine qui tamponne le Ca²[indice supérieur +] à l'intérieur du RS est la source principale de Ca²[indice supérieur +] impliquée dans le couplage EC. En effet, Fenelon et al. (2012) ont estimé que 95% du Ca²[indice supérieur +] dans le RS est lié, avec 5% dans le forme libre (i.e. Ca²[indice supérieur +]), et que plus de 80% du Ca²[indice supérieur +] lié paraît être associé avec la calséquestrine. La raison principale pour développer cette nouvelle méthode a été d'évaluer si le contenu total de Ca intracellulaire est largement réduit dans les muscles KO en CSQ afin de mieux résoudre la controverse sur ce sujet. Contrairement à nos attentes [Ca[indice inférieur T]]MUSCLE a été proche de 2mM dans les muscles contrôles, ce qui est proche de la moyenne mesurée pour les muscles KO en CSQ. Notre hypothèse est qu'il y a une "uprégulation" d'une ou plusieurs protéines de liaison de Ca²[indice supérieur +] dans le RS.
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Longuet, Christine. "Régulation des voies mitogéniques par les molécules modulant la concentration intracellulaire de calcium dans les cellules ß pancréatiques." Montpellier 2, 2004. http://www.theses.fr/2004MON20221.
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Les cellules β pancréatiques sont les seules capables de synthétiser et sécréter de manière régulée de l'insuline, unique hormone hypoglycémiante de l'organisme. Tout déficit de fonctionnement de ces cellules aboutit au développement de pathologies graves dont la plus connue est le diabète. Pour prévenir un tel défaut, les cellules β pancréatiques sont régulées par un grand nombre de facteurs in vivo. Leur régulation par les voies de signalisation mises en jeu par les récepteurs couplés aux protéines G est connue et étudiée depuis de nombreuses années. Plus récemment, il a été mis en évidence une importance capitale des voies de signalisation classiquement mises en jeu par les récepteurs à activité tyrosine kinase des facteurs de croissance. Notamment, ces voies que l'on croyait essentiellement impliquées dans la régulation de la balance prolifération/apoptose, se révèlent également indispensables au bon déroulement du processus de sécrétion d'insuline en réponse à une augmentation de la glycémie. De plus, il est maintenant clair que ces cascades de signalisation, et plus précisément la cascade aboutissant à l'activation des kinases ERK1/2, peuvent être activées indépendamment des récepteurs à activité tyrosine kinase, en réponse à des nutriments ou des peptides agissant par le biais de récepteurs couplés aux protéines G. Dans ces mécanismes dits de transactivation, la modification de la concentration de calcium intracellulaire est souvent un évènement clef. Ainsi, au cours de ma thèse, je me suis attachée à étudier les mécanismes d'activation et le rôle des kinases ERK1/2 par le glucose et le GLP-1, 2 régulateurs majeurs de la physiologie des cellules β pancréatiques<br>Pancreatic β cells represent the only cell type able to synthesize and secrete in regulated manner insulin, unique hypoglycemic hormone. A failure in there physiology leads to pathologic phenotypes such as diabetes. To prevent from this, β cells are regulated by a wide variety of factors in vivo. Regulation by G-protein coupled receptors is known and studied since a long time. More recently, it has been shown that signaling pathways engaged upon tyrosine kinase receptors activation by growth factors are key regulators of the β cell phenotype. Invalidation of these signaling pathways, known up to date to regulate proliferation/apoptosis balance, leads to a defect in glucose-induced insulin secretion. In addition, it is clear now that those pathways, including the ERK1/2 signaling cascade, can be transactivated in response to nutrients or peptides through G-protein coupled receptor. In those transactivation mechanisms, modification of the intracellular calcium concentration plays a key role. Thus, I have studied during my thesis the mechanisms of activation and the roles of ERK1/2 by glucose and GLP-1, 2 key regulators of pancreatic β cells physiology
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Flourakis, Matthieu. "Nouveaux mécanismes de régulation de la concentration calcique réticulaire : implication dans la physiopathologie de la prostate humaine." Phd thesis, Université des Sciences et Technologie de Lille - Lille I, 2007. http://tel.archives-ouvertes.fr/tel-00402635.
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Le cancer de la prostate est la seconde cause de mortalité par cancer chez l'homme. Actuellement, les traitements hormonaux visent à diminuer le taux d'androgènes actifs. Malheureusement, avec le temps, les patients développent un cancer androgènes dont l'issue est fatale. Le calcium (Ca2+), second messager ubiquitaire, est impliqué dans de nombreux processus tels que l'apoptose ou la prolifération. Le Réticulum Endoplasmique (RE) est un acteur essentiel de la signalisation calcique. Ainsi, l'étude de canaux calciques réticulaires est fondamentale dans le développement de nouvelles stratégies thérapeutiques. Les travaux effectués ont permis d'identifier deux nouvelles protéines sur le RE : le translocon et le canal TRPM8 (Transient Receptor Potential Melastatin 8). Ces deux protéines seraient des éléments majeurs de la signalisation calcique en régulant la concentration de Ca2+ du RE. Par ailleurs, l'étude de l'évolution de la signature calcique au cours de la cancérogenèse prostatique a permis de mettre en évidence qu'Orai1 (identifié ici comme étant la protéine responsable de l'Entrée Capacitive de Ca2+) est moins exprimée dans les cancers les plus agressifs. A l'opposé, TRPV6 (Transient receptor potential Vanilloid 6), canal calcique impliqué dans l'entrée constitutive de Ca2+, est surexprimé dans des stades avancés de cancer. Ainsi, les variations d'expression de ces protéines seraient responsables respectivement d'un défaut d'apoptose ou d'une augmentation de la prolifération des cellules cancéreuses prostatiques androgéno-indépendantes. Ceci permettrait d'expliquer l'évolution du cancer de la prostate vers des stades plus agressifs.
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IOUZALEN, LAHCEN. "Regulation de la concentration cytosolique de calcium dans les cellules endotheliales de la veine de cordon ombilical humain en culture : role des stocks intracellulaires de calcium dans le controle de l'influx." Paris 6, 1995. http://www.theses.fr/1995PA066348.
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L'endothelium controle l'hemostase et la tonicite vasculaire via la secretion de nombreuses substances en reponse a l'augmentation de la concentration cytosolique de calcium (ca#2#+#i). Ce travail a pour objectif l'etude des regulations de l'influx de ca#2#+ dans des cellules endotheliales humaines soumises a differentes conditions de depletion des stocks internes de ca#2#+. L'histamine, un mediateur de l'inflammation, provoque une reponse calcique biphasique: un pic transitoire correspondant a la liberation du ca#2#+ des stocks internes, suivi d'une augmentation soutenue de ca#2#+#i refletant un influx de ca#2#+. Nos resultats montrent que ca#2#+#i reste elevee dans la cellule endotheliale tant que l'histamine est au contact de son recepteur ou que les stocks internes de ca#2#+ sont vides. L'histamine libere le ca#2#+ par l'intermediaire de l'ip#3 alors que la thapsigargine provoque la depletion des memes stocks internes de ca#2#+ sans produire d'ip3. Les mecanismes d'activation de l'influx impliques par l'histamine et la thapsigargine sont differents mais interdependants. Dans les cellules stimulees par l'histamine, l'amplitude de l'influx calcique est superieure a celle des cellules traitees par la thapsigargine et sa sensibilite aux variations de la concentration extracellulaire de potassium est differente. De plus, la depletion des stocks de ca#2#+ par la thapsigargine empeche l'entree de ca#2#+ via les canaux actives par l'histamine. Les canaux actives par l'histamine ou la thapsigargine sont inhibes par l'isradipine et par le sk&f96365. En conclusion, notre travail demontre que le niveau de ca#2#+ a l'interieur des compartiments internes, n'est pas le seul determinant pour activer l'influx de ca#2#+. L'activite des canaux responsables de l'entree de ca#2#+ pourrait etre directement controlee par des messagers intracellulaires associes au metabolisme des phospholipides et/ou l'augmentation de ca#2#+#i
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NOEL, JACQUES. "Etude des fluctuations et des mecanismes de regulation de la concentration de calcium ionise cytosolique dans les hepatocytes isoles de cobaye." Paris 11, 1993. http://www.theses.fr/1993PA112064.
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Dans les hepatocytes, l'insp#3 produit sous stimulation hormonale, provoque une liberation du ca#2#+ a partir des compartiments calciques intracellulaires. Les variations de la ca#2#+#i qui en resultent sont rapidement regulees et forment des oscillations de la ca#2#+#i. Les variations de la ca#2#+#i ont ete suivies par la technique de potentiel impose sur cellule entiere pour suivre l'activation d'une conductance k#+ sensible au ca#2#+ dans des hepatocytes isoles de cobaye. Nous avons reproduit avec les agonistes dependants de l'ampc ainsi qu'avec le tlc-s, un acide biliaire, les memes types d'oscillations calciques que celles decrites pour les agonistes dependants de l'insp#3. Nous avons alors montre que dans des conditions d'inhibition des reponses dependantes de l'insp#3, soit avec un anticorps antiptdinsp#2 soit avec un anticorps anti-recepteur de l'insp#3, les variations de la ca#2#+#i produites par les agonistes dependants de l'ampc ainsi que par le tlc-s ne sont pas affectees. Ces resultats suggerent que si les mecanismes de liberation du ca#2#+ intracellulaire sont probablement distincts d'une voie de transduction du signal a une autre, les mecanismes de regulation de la ca#2#+#i, responsables de la formation des oscillations calciques, sont probablement communs a toutes ces voies
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Collet, Claude Christian. "Etude de la régulation de la concentration intracellulaire en calcium dans la fibre musculaire squelettique de souris normale et dystrophique (mdx)." Lyon 1, 2001. http://www.theses.fr/2001LYO10141.
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La contraction du muscle squelettique est sous le contôle d'un ensemble de mécanismes assurant une régulation étroite de la concentration en calcium libre cytoplasmique ([Ca2́+]). Le présent travail apporte des éléments nouveaux à la connaissance de ces mécanismes, sur fibre musculaire intacte, dans les conditions normales et pathologiques. Trois aspects ont été traités:(i) les effets de la ryanodine sur la régulation de la [Ca2+]. Les résultats montrent que cet agent pharmacologique produit une fuite de calcium à partir du réticulum sarcoplasmique (RS), dont l'amplitude est sous le contrôle de la durée et du niveau de dépolarisation de la membrane plasmique. Ceci suggère qu'une fraction prédéterminée de canaux calciques du RS serait activée par une dépolarisation d'amplitude et de durée données. (ii) l'étude de la régulation de [Ca2+] dans le muscle de souris mdx, un modèle de la myopathie de Duchenne dans laquelle un dysfonctionnement de cette régulation est suspecté: la [Ca2+] au repos ainsi que les variations de [Ca2+] induites par des dépolarisations imposées ne sont pas altérées de manière importante sur le modèle mdx. Par ailleurs, les fonctions de détecteur de potentiel du récepteur aux dihydropyridines présent dans le sarcolemme, sont similaires sur fibres musculaires contrôle et mdx, alors que ses fonctions de canal calcique sont sensiblement modifiées dans la muscle mdx. Ces modifications représentent sans doute une conséquence de l'état pathologique des fibres mdx. (iii) l'étude des propriétés de diffusion des ions Mg2́+ dans le milieu intracellulaire. Le Mg2+ intracellulaire a un rôle prépondérant dans le couplage excitation-contraction, mais certaines propriétés fondamentales concernant sa régulation sont inconnues. Le travail réalisé ici a permis de déterminer la constante de diffusion du Mg2+ dans le cytoplasme (190um2. S-1). Cette valeur suggère l'existence de sites de fixation statiques et de faible affinité vis à vis du Mg2+.
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Anh, Viet Bui, of Western Sydney Hawkesbury University, of Science Technology and Environment College, and of Science Food and Horticulture School. "A study of osmotic distillation in hollow fibre modul." THESIS_CSTE_SFH_Anh_V.xml, 2002. http://handle.uws.edu.au:8081/1959.7/4.
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Osmotic distillation is a process of removing water from an aqueous solution, driven by water vapour pressure gradient across a hydrophobic membrane. The process occurs at or below ambient temperature and under atmospheric pressure. This research project investigates the osmotic distillation process in hollow fibre modules using hollow fibres PP375, PV375 and PV660 supplied by Memcor Australia. Operating conditions such as temperature, feed concentration and brine cross flow velocity, but not the feed cross flow velocity, were found to have significant effect on the flux. Models for heat and mass transfers were used to study the polarisation phenomena in osmotic distillation. Temperature and concentration profiles at the membrane surfaces due to polarisation were quantified. Scholfield and Ordinary Diffusion models for flux prediction based on the bulk conditions were developed and validated. Models for water activity and viscosity of aqueous glucose and calcium chloride solutions were also developed and validated in this work.<br>Master of Science (Hons)
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Tsurumi, Fumitoshi. "The intracellular Ca²⁺ concentration is elevated in cardiomyocytes differentiated from hiPSCs derived from a Duchenne muscular dystrophy patient." Kyoto University, 2020. http://hdl.handle.net/2433/253462.
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Silvestri, Livia. "The regulation of intracellular calcium ion concentration and mitochondrial function by cyclosporin A, a putative mechanism for the pathogenesis of gingival overgrowth." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0016/MQ53417.pdf.
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David-Dufilho, Monique. "Regulation pharmacologique de la concentration cytosolique d'ions calcium dans les erythrocytes et les myocytes et fibroblastes cardiaques en culture : application a l'hypertension primaire." Paris 6, 1991. http://www.theses.fr/1991PA066089.
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La concentration cytosolique d'ions calcium module de nombreuses activites cellulaires. Elle est controlee par des mecanismes de transport de calcium situes dans les membranes internes et plasmiques. L'hypertension primaire semble etre associee a des valeurs elevees de la concentration cytosolique d'ions calcium qui ont ete observees dans plusieurs types cellulaires. L'erythrocyte ne dispose que de deux mecanismes de transport pour maintenir sa concentration cytosolique de calcium: un influx qui reste a caracteriser et une pompe calcique, responsable de la sortie de calcium, qui a ete bien etudiee. La fluorescence intrinseque de l'hemoglobine a jusqu'a present empeche la determination de la concentration erythrocytaire de calcium par des mesures directes de fluorescence. Nous decrivons ici une methode pour la mesurer directement avec le chelateur calcique fluorescent, fura-2. Nous observons qu'elle est augmentee dans l'hypertension essentielle et genetique du rat de souche okamoto. Ces valeurs elevees de la concentration erythrocytaire de calcium sont associees a une plus grande participation de la composante sensible aux dihydropyridines de l'influx calcique. Nous demontrons que l'influx calcique est inhibe de facon dose-dependante par les dihydropyridines suggerant la presence de canaux calciques de type l dans les membranes erythrocytaires. Nous decrivons egalement la determination par des mesures en fluorescence frontale de la concentration cytosolique de calcium dans les myocytes et les fibroblastes cardiaques cultives en monocouche. La concentration de calcium est augmentee uniquement dans les myocytes de rats spontanement hypertendus
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Lima, Regina Karla de Pontes [UNESP]. "Avaliação da difusão de íons hidroxila e da atividade antibacteriana de medicação intracanal á base de hidróxido de cálcio." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/101638.
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lima_rkp_dr_arafo.pdf: 692401 bytes, checksum: 6c17d09894639b5d27ecc81f49ce48d5 (MD5)<br>Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>Este estudo objetivou avaliar a capacidade de liberação e difusão de íons hidroxila, e a atividade antibacteriana de medicações intracanal, in vitro. No primeiro experimento, canais radiculares de dentes bovinos foram instrumentados. Uma cavidade de 4 mm de comprimento, 2 mm de largura e 0,5 mm de profundidade foi confeccionada no terço médio/apical radicular de cada amostra. A abertura coronária e a superfície externa radicular foram seladas com adesivo e esmalte para unhas, exceto a área da cavidade preparada. Os canais radiculares foram preenchidos com as seguintes medicações: G1: hidróxido de cálcio (Ca(OH)2)/soro; G2: Calen; G3: Calen/PMCC; G4: Calen/Clorexidina (CLX) a 0,4%. Os dentes foram armazenados individualmente em frascos contendo água destilada a 37oC. As medições do pH foram realizadas nos períodos de 1, 3, 7, 14, 21, 30 e 60 dias, com utilização de pHmetro digital. Os resultados mostraram aumento significativo do pH a partir de 3 dias para a pasta Calen/CLX e para as demais pastas a partir de 7 até os 14 dias. Para a pasta Calen ocorreu aumento até os 21 dias. A pasta Calen/PMCC apresentou pH mais elevado até 21 dias, sendo os resultados semelhantes para todos grupos aos 30 dias. Aos 60 dias, os maiores valores de pH foram observados para as pastas Calen/PMCC e Calen. Conclui-se que as diferentes composições de pastas à base de Ca(OH)2 proporcionam difusão de íons hidroxila pela dentina radicular. Em outro experimento, 106 dentes humanos unirradiculados tiveram seus canais radiculares contaminados com Enterococcus faecalis e incubados a 37°C por 21 dias. Em seguida, foram divididos de acordo com a medicação intracanal e o período em: G1: Calen - 7 dias; G2: Calen - 14 dias; G3: Calen/PMCC - 7 dias; G4: Calen/PMCC - 14 dias; G5: Calen/CLX a 0,4% - 7 dias; G6: Calen/CLX a 0,4% - 14 dias; G7: Calen/CLX a 1% - 7 dias; G8: Calen/CLX a 1% - 14 dias....<br>The aim of this study was to evaluate the release and diffusion of hydroxil ions, and the antibacterial activity of intracanal medication, in vitro. At first study, root canals from bovine teeth were instrumented. A cavity with 4 mm of length, 2 mm of width and 0.5 mm of depth was opened at middle/apical third of each sample. The coronal opening and the external surface of the roots were coated with a nail polish layer and a layer of sticky wax, except on the cavity area. Root canals were filled with the following intracanal medication: G1: calcium hydroxide powder with saline solution (Ca(OH)2); G2: Calen; G3: Calen/PMCC; G4: Calen/Chlorhexidine (CHX) 0.4%. Teeth were stored individually in recipients with distilled water at 37oC. Measurements of pH were made at periods of 1, 3, 5, 7, 14, 21, 30 and 60 days, using a digital pH meter. Results showed a significant increase of pH from 3 days for Calen/PMCC, and from 7 until 14 days for the other medications. For Calen, an increase was observed until 21 days. Calen/PMCC showed the highest pH until 21 days, and all the groups had similar results at 30 days. At 60 days, the highest pH values were observed for Calen/PMCC and Calen. It is possible to conclude that different compositions of calcium hydroxide pastes caused diffusion of hydroxil ions through radicular dentin. In another study, 106 single-rooted human teeth had their root canals contaminated with Enterococcus faecalis and incubated at 37oC for 21 days. Then, these teeth were divided according to intracanal medication and periods: G1: Calen - 7 days; G2: Calen - 14 days; G3: Calen/PMCC - 7 days; G4: Calen/PMCC - 14 days; G5: Calen/CHX 0.4% - 7 days; G6: Calen/CHX 0.4% - 14 days; G7: Calen/CHX 1% - 7 days; G8: Calen/CHX 1% - 14 days. Microbiological samples were collected immediately after intracanal medication removal and after seven days. After serial 10-fold dilutions and culture... (Complete abstract click electronic access below)
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Weatherholt, Riley Madison. "Road Salt Runoff into Freshwater Wetlands: Trends in SpecificConductance and Ion Concentration." Kent State University Honors College / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors1557152479759316.
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Lecourieux, David. "Analyse fonctionnelle des variations de la concentration en calcium libre dans le cytoplasme et le noyau des cellules de tabac en réponse à des éliciteurs des réactions de défense : identification de protéines kinases cibles." Dijon, 2001. http://www.theses.fr/2001DIJOS062.
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Au cours de ce travail, nous avons étudié le rôle du Ca2+ dans le mode d'action de la cryptogéine, un éliciteur des réactions de défense chez le tabac. Des suspensions cellulaires de tabac exprimant l'aequorine ont été utilisées pour analyser les variations de la concentration cytosolique en Ca2+ libre ([Ca2+]cyt) en réponse à la cryptogéine ou à des éliciteurs oligosaccharidiques. La signature [Ca2+]cyt induite par la cryptogéine se caractérise par un premier pic transitoire de [Ca2+]cyt suivi d'une seconde élévation prolongée de [Ca2+]cyt vraisemblablement reliée à la dépolymérisation des microtubules et à l'activation de la mort cellulaire. Le peroxyde d'hydrogène produit suite à l'activation Ca2+-dépendante de la NADPH-oxydase de la membrane plasmique, participe aux variations de [Ca2+]cyt provoquées par la cryptogéine ou les OGs. Par ailleurs, l'utilisation de cellules de tabac exprimant l'aequorine dans le noyau nous a permis de montrer que la cryptogéine induit une élévation de [Ca2+]nuc intense, contrairement aux éliciteurs oligosaccharidiques. La recherche de cibles moléculaires du Ca2+ nous a permis d'identifier 3 protéines kinases (40, 60 et 72 kDa). L'activité des PKs de 60 et 72 kDa est Ca2+-dépendantes et se maintient pendant 2 h. La PK de 72 kDa pourrait correspondre à une protéine de tabac homologue de la CCaMK identifiée chez le mai͏̈s.
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Baldin, Samira Rodrigues [UNESP]. "Desempenho, características de carcaça e atributos da carne de bovinos jovens confinados suplementados com vitaminas D e E." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/95328.
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baldin_sr_me_botfmvz.pdf: 242061 bytes, checksum: 910af57b2752ba72663958dd36daa68a (MD5)<br>Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)<br>Universidade Estadual Paulista (UNESP)<br>O experimento foi conduzido no confinamento da Unesp/Botucatu, com o objetivo de avaliar a influência da suplementação das vitaminas D e E sobre o desempenho, características de carcaça e atributos de carne de bovinos jovens confinados. Foram utilizados 36 machos inteiros, 18 Nelore (NE) e 18 Canchim (CC); desmamados aos sete meses de idade, com peso vivo médio de 234,53 ± 22,15 e 248,13 ± 34,67 kg, respectivamente. Os animais foram confinados por 134 dias. Aos quarenta e sete dias pré-abate, nove animais NE e nove animais CC, foram suplementados com 1300 UI/vitamina E/dia e 10 dias antes do abate, os mesmos animais foram suplementados com 7,5 x 106 UI/vitamina D3/dia. No último dia da suplementação, foram colhidas amostras de sangue dos animais, para avaliar o cálcio plasmático. O pH da carcaça foi mensurado à zero e 24hs após o abate. Na desossa, foram colhidas amostras de Longissimus, entre a 12a e 13a costelas, para análise de força de cisalhamento, perdas por cocção, índice de fragmentação miofibrilar, lipídeos totais, concentração de vitamina D e E na carne e exposição sob condições simuladas de varejo. A cor e o pH da carne, foram mensurados diariamente nas amostras expostas. No primeiro e no último dia de exposição foram colhidas amostras da gordura subcutânea, para análise do perfil de ácidos graxos. Não houve efeito da suplementação de vitaminas D e E sobre o desempenho, características de carcaça e atributos da qualidade da carne, porém houve efeito para cálcio plasmático. A suplementação de vitaminas D e E, não foi efetiva para melhorar o desempenho, as características de carcaça e os atributos de qualidade da carne de bovinos jovens confinados.<br>The experiment was conducted at Unesp/Botucatu feedlot, with the objective to evaluate the supplementation of vitamin D and E on performance, carcass characteristics and meat quality of feedlot bullocks. It was used 36 animals, 18 Nellore (NE) and 18 Canchim (CC), weaned at seven months and average initial body weight of 234.53 ± 22.15 and 248.13 ± 34.67 kg, respectively, fed for134 days. At the forty seventh day prior slaughter, nine NE and nine CC were supplemented with 1300 IU/vitamin E/day and 10 days prior slaughter, the same animals were supplemented with 7.5 x 106 IU/vitamin D3/day. At last day of supplementation, blood samples were taken to evaluate plasmatic calcium. Carcass pH was measured at 0 and 24hrs after slaughter. At boning process, Longissimus samples were collected between 12th and 13th ribs for sear force, cooking loss, miofibrilar fragmentation index, total lipids, vitamin D and E concentrations, and retail conditions storage simulation. Meat color and pH of the samples were daily measured. Fatty acid profile samples were collected at first and last day of retail condition storage simulation. There was no effect of vitamin D and E on feedlot performance, carcass characteristics and meat quality, although plasmatic calcium effect was observed. In conclusion, vitamin D and E were not effective to enhance feedlot performance, carcass characteristics and meat quality of feedlot bullocks.
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Wise, Peter Leonard. "Structure-microwave dielectric property relations in Sr and Ca titanates." Thesis, University of Sheffield, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391169.
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Diserbo, Michel. "Action du Platelet-Activating Factor (PAF) sur les cellules de la lignée N1E-115 : effets sur la concentration du calcium libre cytosolique et sur les flux ioniques transmembranaires." Université Joseph Fourier (Grenoble), 1995. http://www.theses.fr/1995GRE10073.
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Le paf (1-o-alkyl-2-acetyl-sn-glycero-3-phosphorylcholine) est aujourd'hui reconnu comme un des plus importants neuromediateurs lipidiques. Dans ce travail, nous montrons une action du paf sur les cellules de la lignee de neuroblastome n1e-115. Par les techniques de liaison, nous avons mis en evidence sur ces cellules la presence de deux types de recepteurs du paf. L'activation de ces recepteurs par des concentrations physiologiques de paf produit une accumulation d'inositol triphosphate, et une augmentation rapide et transitoire du calcium libre cytosolique. Cette augmentation du calcium libre cytosolique fait intervenir a la fois une redistribution du calcium intracellulaire et des influx de calcium externe. Ces influx de calcium passent essentiellement via des canaux permeables aux ions ca#2#+ de type receptor-operated channel. Nous montrons la presence, sur ces cellules, de canaux permeables au ca#2#+ et activables par la thapsigargine correspondant tres probablement a des canaux calciques activables via la depletion des reserves intracellulaires. Ces canaux interviennent dans la reponse induite par le paf. A l'aide de la technique de voltage impose sur cellule entiere, nous avons mis en evidence une activation possible par le paf des canaux calciques sensibles au voltage de type l. Cependant, cette derniere action du paf ne participe que, de facon minime, aux entrees de ca#2#+. L'activation de ces canaux est, en effet, bloquee par une hyperpolarisation transitoire en reponse a l'activation par le paf de canaux potassiques du type bk(ca). Cette derniere action du paf est la consequence de la seule augmentation du calcium libre cytosolique, et ne resulte pas d'une action directe du paf sur ces bk(ca). Enfin, a l'aide de la technique du patch-clamp, nous n'avons pas mis en evidence l'effet du paf sur les autres permeabilites ioniques membranaires de ces cellules (courants na#+ et k#+ sensibles au potentiel)
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Boutonnat, Frédérique. "Contribution à l'étude expérimentale de l'interaction verre basaltique-eau de mer à 50°C et 90°C : influence du rapport eau/roche et de la concentration en magnésium et calcium." Orléans, 1986. http://www.theses.fr/1986ORLE0410.
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CHAMPIGNEULLE, AGNES. "Regulation de la concentration intracellulaire de calcium ionise (ca#2#+)#i dans le canal collecteur du rein de rat. Role des recepteurs v#1 et v#2 de la vasopressine." Paris 6, 1995. http://www.theses.fr/1995PA066559.
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La mesure de la concentration intracellulaire de calcium ionise (ca#2#+#i) par une technique de microfluorometrie sur segment de nephron isole microdisseque nous a permis d'etudier la nature des canaux et transporteurs membranaires du calcium presents dans les membranes plasmiques du canal collecteur du rein de rat ; l'effet de l'ampc et des hormones activant l'adenylate cyclase sur la ca#2#+#i ; ainsi que le role respectif des recepteurs v#1 et v#2 de la vasopressine dans les variations de ca#2#+#i induites par l'hormone: 1) les variations de la concentration de calcium externe induisent des variations de ca#2#+#i dans la portion corticale du canal collecteur (ccd) ; 2) ces variations de ca#2#+#i sont dues a une entree de calcium d'origine basolaterale, vraisemblablement par des canaux membranaires non voltage-dependants ; 3) ni l'echangeur na/ca, ni le recepteur membranaire du calcium (couple a la phospholipase c) recemment decrit ne sont en cause dans ces variations de ca#2#+#i ; 4) l'ampc induit dans le ccd d'importantes variations de ca#2#+#i, essentiellement par stimulation d'un influx basolateral de calcium ; cet effet est reproduit par les hormones stimulant l'adenylate cyclase (calcitonine, ddavp, agonistes adrenergiques) ; l'isoprenaline induit en outre une liberation marquee de calcium intracellulaire ; 5) l'avp induit des variations de ca#2#+#i relevant, dans le ccd et l'omcd, a la fois des recepteurs v#1#a et v#2 ; ces variations se retrouvent dans l'imcd, mais elles sont dues dans ce segment a la stimulation d'un recepteur unique, atypique, ayant les caracteristiques pharmacologiques d'un recepteur v#2 mais un mode de transduction de type v#1
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Boutonnat, Frédérique. "Contribution à l'étude expérimentale de l'interaction verre basaltique-eau de mer à 50 °C et 90 °C, influence du rapport eau/roche et de la concentration en magnésium et calcium." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb375963815.
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Bier, Carlos Alexandre Souza. "Avaliação do pH, da liberação de íons cálcio e da adesividade de cimentos endodônticos contendo hidróxido de cálcio ou à base de MTA /." Araraquara : [s.n.], 2009. http://hdl.handle.net/11449/104185.
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Orientador: Mário Tanomaru Filho<br>Banca: Luis Geraldo Vaz<br>Banca: Idomeo Bonetti Filho<br>Banca: Marco Antônio Hungaro Duarte<br>Banca: Marcus Vinicius Reis Só<br>Resumo: O objetivo desse estudo foi a avaliação da liberação de íons cálcio, do pH e da adesividade de alguns cimentos utilizados em Endodontia: Sealapex (G1), Sealer 26 (G2), Acroseal (G3), Epiphany (G4), MTA Branco (G5), Endo CPM Sealer (G6). Após a espatulação, os materiais foram inseridos em tubos de polietileno medindo 1,5 mm de diâmetro interno e 1 cm de comprimento com ambas extremidades abertas e imersos em frascos de vidro contendo 10 mL de água ultra pura. Nos períodos de 2, 6, 12, 24 e 48 horas, 7, 14 e 28 dias foram realizadas as análises, sendo o tubo contendo o cimento transferidos para novo frasco a cada período. O pH e a liberação de íons cálcio foram avaliados, respectivamente por meio de pH metro e espectrofotometria de absorção atômica. Para a avaliação da adesividade dos cimentos endodônticos às paredes dentinárias, os canais radiculares de 28 dentes humanos uniradiculados foram dilatados com brocas de Gates Glidden número 1, 2 e 3 e brocas largo número 1, 3 e 5. As raízes foram cortadas em máquina de corte para confecção de discos de 2 mm de espessura. Durante o preparo e depois da secção os espécimes foram irrigados com solução de hipoclorito de sódio a 2,5% e com EDTA a 17 % para a remoção da smear layer. Após a divisão aleatória nos grupos experimentais, os espécimes foram secos e preenchidos com os cimentos endodônticos, sendo mantidos em estufa a 37oC e 95% de umidade relativa do ar por 48 hs. Em seguida, cada conjunto dentina/cimento endodôntico foi submetido ao teste push-out em uma máquina de ensaio mecânico e a tensão necessária para a remoção do cimento medida em Mega Pascal (MPa). Após a coleta dos dados estes foram submetidos à análise estatística de Análise Variância e teste Tukey, com nível de 5% de significância. Os maiores valores de pH foram obtidos pelos G6, seguido por G2 e G5 após 2 horas (P<0,05)... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: The aim of this study was to evaluate in vitro the pH, calcium ion release and adhesiveness provide by 6 endodontic filling materials: Sealapex (G1), Sealer 26 (G2), Acroseal (G3), Epiphany (G4), White MTA (G5), Endo CPM Sealer (G6). After manipulation, the sealers (n=10) were placed in tubes with 10 mm-long and 1.5 mm in diameter and immediately immersed in a glass flask containing 10 ml of ultra pure water, which was hermetically sealed and stored at 37°C. At 2, 6, 12, 24 and 48 hr, and at 7, 14 and 28 days after mixing the tubes were moved to new flask with fresh solution and the water in which they were immersed was analyzed for pH with a pH meter and for released calcium by atomic absorption spectrophotometry. To evaluate the adhesiveness of the sealers to the root canal wall, 28 teeth were enlarged to size 5 Largo drill and cut in a cutting machine to create 2 mm thickness slices. During all this procedure the root canal was irrigated with sodium hypochlorite 2.5% and with EDTA 17% to remove the smear layer. The slices were randomly allocated to one of the groups, dried and filled with the sealers and kept in a controlled environment (37oC and 95% humidity) to allow the setting of the sealers. After that, the slice root/endodontic sealer was submitted to push out test in a mechanical testing machine and the results were expressed in Mega Pascal (MPa). The results obtained at each time were statistically evaluated. After 2 hours the uppermost pH was found in the G6, followed by G2 and G5 (P<0,05). From 6 h till 24 h the highest value were observed in groups G5, G6 and G2. After 48 hours, the pH of groups G5 and G6 were stood out. Finally from the 7th to 28th days of evaluation G2, G5 and G6 presented the utmost pH. With regards to calcium ions release in beginning periods the G6 was statistical significantly from the other groups until the 7th day (P<0.05)... (Complete abstract click electronic access below)<br>Doutor
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Al-Maghrabi, Mufied Mahmoud. "Thermoluminescence spectra from sulphates, fluorides and garnets doped with rare earth ions." Thesis, University of Sussex, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366054.
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Luminescence measurements have been applied to three different structures namely, sulphate, fluorides and YAG. In all cases the RE doping suppresses the intrinsic emission and results in intense luminescence characteristic of the RE dopant. Additionally, in double doped samples, or contaminated ones, the TL data show that each dopant defines a glow peak, which is displaced in temperature relative to the others. Examples of this were discussed for CaS04:Ce,Mn; YAG:Nd,Tb,Cr,Mn; BaF2:Ho,Ce and BaF2:Tm,Ce. The data are discussed in terms of an energy transfer model between different parts of extended defect complexes which encompass the RE ion and the lattice defects. Calcium sulphate doped with Dy define a TL peak near 200°C suitable for radiation measurements, but when co-doped with Ag the TL peak move to higher temperatures with minor effects on the peak sensitivity. In Ce,Mn double doped samples, the peak temperatures differ by -7°C between the Ce and Mn sites. The TL glow curves from alkaline earth fluorides are complex and contain several overlapping peaks. Curve fitting show that the peak maxima below room temperature are insensitive to the RE dopant. Additionally the host material has a modest effect on the peak positions. Above room temperature each dopant provides a TL curve specific to the added RE ion and do not show common peaks. Concentration has many effects on the resultant glow curve, and even at the lowest concentration used here (0.01%) there is evidence of cluster formation. Samples with high RE content show low values of the frequency factor consistent with the energy transfer model in that the emission from RE-RE cluster dominates over the emission from direct charge recombination within the defect complex. The effect of concentration and the TL mechanism operating below room temperature are also discussed. Luminescence signals from the near surface of YAG:Nd (via CL) were contrasted with those from the bulk material via RL. Results indicate that the outer few micron layers differ significantly in luminescence response from the bulk crystal. The differences were ascribed to result from solvents that enter the YAG lattice during the growth stage or subsequently from cleaning treatments via the dislocations caused by cutting and polishing. Additionally, the growth stage may include gases from the residual air in the growth furnace trapped into the YAG lattice. In each case there is a discontinuity in luminescence intensity and/or emission wavelengths at temperatures which mach the phase transitions of the contaminants. At the transition temperature there will be a sudden pressure change and this will induce surface expansion or bulk compression. The differences between the two cases were detected by the alternatives of CL and RL excitation, where the Nd or Er lines have moved in opposite directions. The detection of such low concentrations of solvents/trapped gases by luminescence is extremely difficult due to experimental limitations. Hence their role in luminescence generation is normally ignored.
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Lima, Regina Karla de Pontes. "Avaliação da difusão de íons hidroxila e da atividade antibacteriana de medicação intracanal á base de hidróxido de cálcio /." Araraquara : [s.n], 2010. http://hdl.handle.net/11449/101638.
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Orientador: Juliane Maria Guereiro Tanomaru<br>Banca: Evandro Watanabe<br>Banca: Igor Prokopowitsch<br>Banca: Gisele Faria<br>Banca: Idomeo Bonetti Filho<br>Resumo: Este estudo objetivou avaliar a capacidade de liberação e difusão de íons hidroxila, e a atividade antibacteriana de medicações intracanal, in vitro. No primeiro experimento, canais radiculares de dentes bovinos foram instrumentados. Uma cavidade de 4 mm de comprimento, 2 mm de largura e 0,5 mm de profundidade foi confeccionada no terço médio/apical radicular de cada amostra. A abertura coronária e a superfície externa radicular foram seladas com adesivo e esmalte para unhas, exceto a área da cavidade preparada. Os canais radiculares foram preenchidos com as seguintes medicações: G1: hidróxido de cálcio (Ca(OH)2)/soro; G2: Calen; G3: Calen/PMCC; G4: Calen/Clorexidina (CLX) a 0,4%. Os dentes foram armazenados individualmente em frascos contendo água destilada a 37oC. As medições do pH foram realizadas nos períodos de 1, 3, 7, 14, 21, 30 e 60 dias, com utilização de pHmetro digital. Os resultados mostraram aumento significativo do pH a partir de 3 dias para a pasta Calen/CLX e para as demais pastas a partir de 7 até os 14 dias. Para a pasta Calen ocorreu aumento até os 21 dias. A pasta Calen/PMCC apresentou pH mais elevado até 21 dias, sendo os resultados semelhantes para todos grupos aos 30 dias. Aos 60 dias, os maiores valores de pH foram observados para as pastas Calen/PMCC e Calen. Conclui-se que as diferentes composições de pastas à base de Ca(OH)2 proporcionam difusão de íons hidroxila pela dentina radicular. Em outro experimento, 106 dentes humanos unirradiculados tiveram seus canais radiculares contaminados com Enterococcus faecalis e incubados a 37°C por 21 dias. Em seguida, foram divididos de acordo com a medicação intracanal e o período em: G1: Calen - 7 dias; G2: Calen - 14 dias; G3: Calen/PMCC - 7 dias; G4: Calen/PMCC - 14 dias; G5: Calen/CLX a 0,4% - 7 dias; G6: Calen/CLX a 0,4% - 14 dias; G7: Calen/CLX a 1% - 7 dias; G8: Calen/CLX a 1% - 14 dias.... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: The aim of this study was to evaluate the release and diffusion of hydroxil ions, and the antibacterial activity of intracanal medication, in vitro. At first study, root canals from bovine teeth were instrumented. A cavity with 4 mm of length, 2 mm of width and 0.5 mm of depth was opened at middle/apical third of each sample. The coronal opening and the external surface of the roots were coated with a nail polish layer and a layer of sticky wax, except on the cavity area. Root canals were filled with the following intracanal medication: G1: calcium hydroxide powder with saline solution (Ca(OH)2); G2: Calen; G3: Calen/PMCC; G4: Calen/Chlorhexidine (CHX) 0.4%. Teeth were stored individually in recipients with distilled water at 37oC. Measurements of pH were made at periods of 1, 3, 5, 7, 14, 21, 30 and 60 days, using a digital pH meter. Results showed a significant increase of pH from 3 days for Calen/PMCC, and from 7 until 14 days for the other medications. For Calen, an increase was observed until 21 days. Calen/PMCC showed the highest pH until 21 days, and all the groups had similar results at 30 days. At 60 days, the highest pH values were observed for Calen/PMCC and Calen. It is possible to conclude that different compositions of calcium hydroxide pastes caused diffusion of hydroxil ions through radicular dentin. In another study, 106 single-rooted human teeth had their root canals contaminated with Enterococcus faecalis and incubated at 37oC for 21 days. Then, these teeth were divided according to intracanal medication and periods: G1: Calen - 7 days; G2: Calen - 14 days; G3: Calen/PMCC - 7 days; G4: Calen/PMCC - 14 days; G5: Calen/CHX 0.4% - 7 days; G6: Calen/CHX 0.4% - 14 days; G7: Calen/CHX 1% - 7 days; G8: Calen/CHX 1% - 14 days. Microbiological samples were collected immediately after intracanal medication removal and after seven days. After serial 10-fold dilutions and culture... (Complete abstract click electronic access below)<br>Doutor
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Bier, Carlos Alexandre Souza [UNESP]. "Avaliação do pH, da liberação de íons cálcio e da adesividade de cimentos endodônticos contendo hidróxido de cálcio ou à base de MTA." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/104185.
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bier_cas_dr_arafo.pdf: 458795 bytes, checksum: df3d3967d50d9e31912505515f745092 (MD5)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>O objetivo desse estudo foi a avaliação da liberação de íons cálcio, do pH e da adesividade de alguns cimentos utilizados em Endodontia: Sealapex (G1), Sealer 26 (G2), Acroseal (G3), Epiphany (G4), MTA Branco (G5), Endo CPM Sealer (G6). Após a espatulação, os materiais foram inseridos em tubos de polietileno medindo 1,5 mm de diâmetro interno e 1 cm de comprimento com ambas extremidades abertas e imersos em frascos de vidro contendo 10 mL de água ultra pura. Nos períodos de 2, 6, 12, 24 e 48 horas, 7, 14 e 28 dias foram realizadas as análises, sendo o tubo contendo o cimento transferidos para novo frasco a cada período. O pH e a liberação de íons cálcio foram avaliados, respectivamente por meio de pH metro e espectrofotometria de absorção atômica. Para a avaliação da adesividade dos cimentos endodônticos às paredes dentinárias, os canais radiculares de 28 dentes humanos uniradiculados foram dilatados com brocas de Gates Glidden número 1, 2 e 3 e brocas largo número 1, 3 e 5. As raízes foram cortadas em máquina de corte para confecção de discos de 2 mm de espessura. Durante o preparo e depois da secção os espécimes foram irrigados com solução de hipoclorito de sódio a 2,5% e com EDTA a 17 % para a remoção da smear layer. Após a divisão aleatória nos grupos experimentais, os espécimes foram secos e preenchidos com os cimentos endodônticos, sendo mantidos em estufa a 37oC e 95% de umidade relativa do ar por 48 hs. Em seguida, cada conjunto dentina/cimento endodôntico foi submetido ao teste push-out em uma máquina de ensaio mecânico e a tensão necessária para a remoção do cimento medida em Mega Pascal (MPa). Após a coleta dos dados estes foram submetidos à análise estatística de Análise Variância e teste Tukey, com nível de 5% de significância. Os maiores valores de pH foram obtidos pelos G6, seguido por G2 e G5 após 2 horas (P<0,05)...<br>The aim of this study was to evaluate in vitro the pH, calcium ion release and adhesiveness provide by 6 endodontic filling materials: Sealapex (G1), Sealer 26 (G2), Acroseal (G3), Epiphany (G4), White MTA (G5), Endo CPM Sealer (G6). After manipulation, the sealers (n=10) were placed in tubes with 10 mm-long and 1.5 mm in diameter and immediately immersed in a glass flask containing 10 ml of ultra pure water, which was hermetically sealed and stored at 37°C. At 2, 6, 12, 24 and 48 hr, and at 7, 14 and 28 days after mixing the tubes were moved to new flask with fresh solution and the water in which they were immersed was analyzed for pH with a pH meter and for released calcium by atomic absorption spectrophotometry. To evaluate the adhesiveness of the sealers to the root canal wall, 28 teeth were enlarged to size 5 Largo drill and cut in a cutting machine to create 2 mm thickness slices. During all this procedure the root canal was irrigated with sodium hypochlorite 2.5% and with EDTA 17% to remove the smear layer. The slices were randomly allocated to one of the groups, dried and filled with the sealers and kept in a controlled environment (37oC and 95% humidity) to allow the setting of the sealers. After that, the slice root/endodontic sealer was submitted to push out test in a mechanical testing machine and the results were expressed in Mega Pascal (MPa). The results obtained at each time were statistically evaluated. After 2 hours the uppermost pH was found in the G6, followed by G2 and G5 (P<0,05). From 6 h till 24 h the highest value were observed in groups G5, G6 and G2. After 48 hours, the pH of groups G5 and G6 were stood out. Finally from the 7th to 28th days of evaluation G2, G5 and G6 presented the utmost pH. With regards to calcium ions release in beginning periods the G6 was statistical significantly from the other groups until the 7th day (P<0.05)... (Complete abstract click electronic access below)
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Kaile, Androulla. "The role of calcium in necrotrophic plant pathogenesis." Thesis, University of Exeter, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253532.
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Baldin, Samira Rodrigues 1981. "Desempenho, características de carcaça e atributos da carne de bovinos jovens confinados suplementados com vitaminas D e E /." Botucatu : [s.n.], 2010. http://hdl.handle.net/11449/95328.
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Resumo: O experimento foi conduzido no confinamento da Unesp/Botucatu, com o objetivo de avaliar a influência da suplementação das vitaminas D e E sobre o desempenho, características de carcaça e atributos de carne de bovinos jovens confinados. Foram utilizados 36 machos inteiros, 18 Nelore (NE) e 18 Canchim (CC); desmamados aos sete meses de idade, com peso vivo médio de 234,53 ± 22,15 e 248,13 ± 34,67 kg, respectivamente. Os animais foram confinados por 134 dias. Aos quarenta e sete dias pré-abate, nove animais NE e nove animais CC, foram suplementados com 1300 UI/vitamina E/dia e 10 dias antes do abate, os mesmos animais foram suplementados com 7,5 x 106 UI/vitamina D3/dia. No último dia da suplementação, foram colhidas amostras de sangue dos animais, para avaliar o cálcio plasmático. O pH da carcaça foi mensurado à zero e 24hs após o abate. Na desossa, foram colhidas amostras de Longissimus, entre a 12a e 13a costelas, para análise de força de cisalhamento, perdas por cocção, índice de fragmentação miofibrilar, lipídeos totais, concentração de vitamina D e E na carne e exposição sob condições simuladas de varejo. A cor e o pH da carne, foram mensurados diariamente nas amostras expostas. No primeiro e no último dia de exposição foram colhidas amostras da gordura subcutânea, para análise do perfil de ácidos graxos. Não houve efeito da suplementação de vitaminas D e E sobre o desempenho, características de carcaça e atributos da qualidade da carne, porém houve efeito para cálcio plasmático. A suplementação de vitaminas D e E, não foi efetiva para melhorar o desempenho, as características de carcaça e os atributos de qualidade da carne de bovinos jovens confinados.<br>Abstract: The experiment was conducted at Unesp/Botucatu feedlot, with the objective to evaluate the supplementation of vitamin D and E on performance, carcass characteristics and meat quality of feedlot bullocks. It was used 36 animals, 18 Nellore (NE) and 18 Canchim (CC), weaned at seven months and average initial body weight of 234.53 ± 22.15 and 248.13 ± 34.67 kg, respectively, fed for134 days. At the forty seventh day prior slaughter, nine NE and nine CC were supplemented with 1300 IU/vitamin E/day and 10 days prior slaughter, the same animals were supplemented with 7.5 x 106 IU/vitamin D3/day. At last day of supplementation, blood samples were taken to evaluate plasmatic calcium. Carcass pH was measured at 0 and 24hrs after slaughter. At boning process, Longissimus samples were collected between 12th and 13th ribs for sear force, cooking loss, miofibrilar fragmentation index, total lipids, vitamin D and E concentrations, and retail conditions storage simulation. Meat color and pH of the samples were daily measured. Fatty acid profile samples were collected at first and last day of retail condition storage simulation. There was no effect of vitamin D and E on feedlot performance, carcass characteristics and meat quality, although plasmatic calcium effect was observed. In conclusion, vitamin D and E were not effective to enhance feedlot performance, carcass characteristics and meat quality of feedlot bullocks.<br>Orientador: Mário De Beni Arrigoni<br>Coorientador: Cyntia Ludovico<br>Banca: Angélica Simone do Cravo Pereira<br>Banca: Saulo da Luz e Silva<br>Mestre
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Kilby, M. D. "Platelet intracellular free calcium concentrations in normotensive and hypertensive pregnancy." Thesis, University of Nottingham, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277488.
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Bellier, Pascale. "Effects of extracellular calcium concentrations on cardiac muscle in selected vertebrates." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ32527.pdf.
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Čmiel, Vratislav. "Optické měření elektromechanických projevů srdečních buněk." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-261217.
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Dissertation is focused on the application of optical measurement methods using techniques of optical microscopy and fluorescence microscopy in measurements of electromechanical characteristics of isolated cardiac cells and clusters of differentiated cardiomyocytes. The first proposed method uses a practical combination of fluorescence microscopy equipped with fluorescent fast and high-resolution camera and atomic force microscopy for simultaneous measurement of calcium transients and contraction of cardiomyocyte clusters. The signals obtained undergoes filtration, processing and analysis. Result function parameters obtained by analyzing signals after application of caffeine are evaluated by comparison with functional parameters obtained during the control measurement. The second proposed method is applied to the cardiomyocyte clusters for the purpose of cardiomyocyte contraction signals measurement. The signals obtained by optical methods are analyzed and compared with the reference signal obtained using atomic force microscopy. Optical measurement method of cell contractins based on detection of cell ends using adjusting of microscopy images by re-sharpening and fluorescence method for cardiomyocyte contractions measurements were designed to increase realiability in simultaneous measurement of cell contractions simultaneously with calcium transients in isolated cardiomyocytes experiments.
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Klinka, Karel, D. Bradley Collins, Louise E. M. de Montigny, M. C. (Michael Charles) Feller, and Christine Chourmouzis. "Forest floor nutrient properties in single- and mixed-species stands of Western hemlock and Western redcedar." Forest Sciences Department, University of British Columbia, 2001. http://hdl.handle.net/2429/709.
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The influence of tree species on forest soils has been the subject of study for at least a century. Of particular interest have been western hemlock (Tsuga heterophylla (Raf.) Sarg.) and western redcedar (Thuja plicata Donn ex D. Don) – two of the most common tree species in coastal and southern British Columbia, but each with a different nutrient amplitude. It has generally been found that acid, mycogeneous Mor humus forms develop in hemlock stands, while less acid and more zoogenous Mormoder, Moder, or even Mull humus forms develop in redcedar stands.
The objective of this study was to determine the influence of hemlock and redcedar, growing separately and together, on forest floor nutrient properties. The questions addressed were: (1) does each stand type have unique forest floor nutrient properties? and (2) can any forest floor nutrient property discriminate between stand types?
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Griffond, Arnaud Camille Maurice. "Concentrating Solar Thermal storage using metal hydride: Study of destabilised calcium hydrides." Thesis, Curtin University, 2019. http://hdl.handle.net/20.500.11937/78467.
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This manuscript aims to study destabilised calcium hydrides system as thermal energy storage for concentration solar power. Using thermodynamic calculation and cost estimation, 3 different systems has been selected for in depth analysis of their thermal properties, the chemical reaction has been observed using in-situ synchrotron as well as their sorption properties. This laboratory scale analysis is used to select a promising material for on field application.