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Letteratura scientifica selezionata sul tema "Ultrastructure analysis"

Autore: Grafiati

Pubblicato: 14 marzo 2023

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Articoli di riviste sul tema "Ultrastructure analysis"

1

Savchenko, S. V., N. G. Oshchepkova, N. P. Bgatova, Yu S. Taskaeva, E. V. Kuznetsov, V. P. Novoselov e A. Yu Letyagin. "Ultrastructural analysis of changes in myocardial blood microvessels in severe burn shock". Сибирский научный медицинский журнал 41, n. 3 (16 giugno 2021): 71–77. http://dx.doi.org/10.18699/ssmj20210310.

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Burn injury is an important medical problem, as it is accompanied by high mortality rates in burn shock. Aim of the study was to conduct an ultrastructural stereological analysis of changes in the blood microvessels of the left ventricular myocardium in burn shock.Material and methods. Myocardial samples during the early section were collected 2 hours after the detection of biological death in the victims from severe burn shock (3 men and 2 women); age group 32-44 years. An ultrastructural study of endothelial cells of the microvasculature of the left ventricular myocardium was carried out.Results and discussion. The development of severe burn shock is accompanied by changes in the ultrastructure of the endothelial cells of the blood microvessels of the left ventricular myocardium, which is associated with intracellular degradation and exocytosis. These ultrastructural changes may indicate impairment of vesicular transport in the endothelium of the myocardial microvessels in burn shock. A feature of the ultrastructure of the endothelium was the heterogeneity of the endothelial cells of the blood capillaries due to the revealed dark and light endothelial cells, which differ in the saturation of the cytoplasm with organelles. The new data obtained on changes in the ultrastructure of the endothelium of the microvasculature of the left ventricular myocardium can be informative in the development of approaches to intensive therapy of cardioprotective direction in combustiological patients with burn shock.

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Matei, Constantin I., Caroline Boulocher, Christelle Boulé, Michael Schramme, Eric Viguier, Thierry Roger, Yves Berthier, Ana-Maria Trunfio-Sfarghiu e Marie-Geneviève Blanchin. "Ultrastructural Analysis of Healthy Synovial Fluids in Three Mammalian Species". Microscopy and Microanalysis 20, n. 3 (18 marzo 2014): 903–11. http://dx.doi.org/10.1017/s1431927614000415.

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AbstractA better knowledge of synovial fluid (SF) ultrastructure is required to further understand normal joint lubrication and metabolism. The aim of the present study was to elucidate SF structural features in healthy joints from three mammalian species of different size compared with features in biomimetic SF. High-resolution structural analysis was performed using transmission electron microscopy (TEM) and scanning electron microscopy (SEM) and environmental SEM/wet scanning transmission electron microscopy mode complemented by TEM and SEM cryogenic methods. Laser-scanning confocal microscopy (LCM) was used to locate the main components of SF with respect to its ultrastructural organization. The present study showed that the ultrastructure of healthy SF is built from a network of vesicles with a size range from 100 to a few hundred nanometers. A multilayered organization of the vesicle membranes was observed with a thickness of about 5 nm. LCM study of biological SF compared with synthetic SF showed that the microvesicles consist of a lipid-based membrane enveloping a glycoprotein gel. Thus, healthy SF has a discontinuous ultrastructure based on a complex network of microvesicles. This finding offers novel perspectives for the diagnosis and treatment of synovial joint diseases.

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3

Shoemark, Amelia, Thomas Burgoyne, Robert Kwan, Mellisa Dixon, Mitali P. Patel, Andrew V. Rogers, Alexandros Onoufriadis et al. "Primary ciliary dyskinesia with normal ultrastructure: three-dimensional tomography detects absence of DNAH11". European Respiratory Journal 51, n. 2 (febbraio 2018): 1701809. http://dx.doi.org/10.1183/13993003.01809-2017.

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In primary ciliary dyskinesia (PCD), motile ciliary dysfunction arises from ciliary defects usually confirmed by transmission electron microscopy (TEM). In 30% of patients, such as those with DNAH11 mutations, apparently normal ultrastructure makes diagnosis difficult. Genetic analysis supports diagnosis, but may not identify definitive causal variants. Electron tomography, an extension of TEM, produces three-dimensional ultrastructural ciliary models with superior resolution to TEM. Our hypothesis is that tomography using existing patient samples will enable visualisation of DNAH11-associated ultrastructural defects. Dual axis tomograms from araldite-embedded nasal cilia were collected in 13 PCD patients with normal ultrastructure (DNAH11 n=7, HYDIN n=2, CCDC65 n=3 and DRC1 n=1) and six healthy controls, then analysed using IMOD and Chimera software.DNAH11 protein is localised to the proximal ciliary region. Within this region, electron tomography indicated a deficiency of >25% of proximal outer dynein arm volume in all patients with DNAH11 mutations (n=7) compared to other patients with PCD and normal ultrastructure (n=6) and healthy controls (n=6). DNAH11 mutations cause a shared abnormality in ciliary ultrastructure previously undetectable by TEM. Advantageously, electron tomography can be used on existing diagnostic samples and establishes a structural abnormality where ultrastructural studies were previously normal.

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Redler, Andrea, Selenia Miglietta, Edoardo Monaco, Roberto Matassa, Michela Relucenti, Matthew Daggett, Andrea Ferretti e Giuseppe Familiari. "Ultrastructural Assessment of the Anterolateral Ligament". Orthopaedic Journal of Sports Medicine 7, n. 12 (1 dicembre 2019): 232596711988792. http://dx.doi.org/10.1177/2325967119887920.

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Background: The anterolateral ligament (ALL) has been identified as a structure on the lateral side of the knee, but debate exists regarding whether it is a capsular thickening or a ligament. Hypothesis: A detailed ultrastructural characterization of the ALL and its ultrastructure collagen arrangement will reveal it more closely resembles ligamentous tissue than joint capsule. Study Design: Descriptive laboratory study. Methods: Eight paired knee samples from 4 fresh-frozen male cadavers were used for this study. Samples were harvested from the ALL, the joint capsule, and the medial collateral ligament (MCL). All samples were evaluated with light microscopy (LM), transmission electron microscopy (TEM), and variable pressure scanning electron microscopy (VP-SEM). With LM, the 3 tissues were analyzed and their morphology described. With TEM, the ultrastructure and collagen characteristics were quantified and compared among specimens. Then, the 3-dimensional characteristics were compared with VP-SEM. Results: Ultrastructure analysis demonstrated similar morphology between the ALL and MCL, with significant differences in these 2 structures as compared with the joint capsule. On LM, the ALL and MCL were characterized by the presence of a dense collagen fiber oriented in the longitudinal and transversal directions of the fiber bundles, while the joint capsule was found to have a more disorganized architecture. On TEM, the collagen fibers of the ALL and MCL demonstrated similar ultrastructural morphology, with both having collagen fibers in parallel, longitudinal alignment. A quantitative analysis was also performed, with the mean (± SD) diameter of fibrils in the ALL and MCL being 80 ± 2.66 nm and 150 ± 3.35 nm, respectively (all P < .001). The VP-SEM highlighted that ALL and MCL morphology demonstrated arrangements of fiber bundles that are densely packed and organized, in contrast to the disorganized fibers of the joint capsule. Conclusion: The ALL and MCL have comparable ultrastructures that are distinctly different from the joint capsule, as visualized on LM, TEM, and VP-SEM. Clinical Relevance: The ALL should be considered a distinctive structure of the knee, although strictly connected to the surrounding capsule.

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Moreno, Silvana Ramos Farias, Jorge José de Carvalho, Ana Lúcia Nascimento, Adriano Arnobio, Beni Olej, Margareth de Oliveira Timóteo, Luiz Querino de Araújo Caldas e Mário Bernardo Filho. "Ultrastructural analysis of kidney, liver and duodenum isolated from treated rats with Ginkgo Biloba extract and effects of this medicinal plant on the biodistribution of the padiopharmaceutical sodium pertechnetate". Brazilian Archives of Biology and Technology 51, spe (dicembre 2008): 185–90. http://dx.doi.org/10.1590/s1516-89132008000700030.

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Ginkgo biloba extract (EGb) has been used to treat memory and concentration deficits, acts as platelet activating factor antagonism and prevents against damages caused by free radicals. EGb is a standardized extract that contains 24% flavonoids and 6% terpenoids. The aim of this work was to evaluate the possible influence of an EGb on the ultrastructure of some organs isolated from rats and on the biodistribution of sodium pertechnetate (99mTcO4Na). The animals were treated with EGb and after six days, received 99mTcO4Na. The organs were isolated and fixed for ultrastructural analysis. The results showed that EGb has modified the ultrastructure of kidney, liver and duodenum and altered the biodistribution of 99mTcO4Na (P<0.05). It is speculated that the substances present in the EGb could act directly or generate metabolites capable to promote changes on the biodistribution of 99mTcO4Na and on the morphology of organs at ultrastructural level.

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Brantner, Christine A., Ryan M. Hannah, James P. Burans e Robert K. Pope. "Inactivation and Ultrastructure Analysis ofBacillus spp. andClostridium perfringensSpores". Microscopy and Microanalysis 20, n. 1 (febbraio 2014): 238–44. http://dx.doi.org/10.1017/s1431927613013949.

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AbstractBacterial endospores are resistant to many environmental factors from temperature extremes to ultraviolet irradiation and are generally more difficult to inactivate or kill than vegetative bacterial cells. It is often considered necessary to treat spores or samples containing spores with chemical fixative solutions for prolonged periods of time (e.g., 1–21 days) to achieve fixation/inactivation to enable electron microscopy (EM) examination outside of containment laboratories. Prolonged exposure to chemical fixatives, however, can alter the ultrastructure of spores for EM analyses. This study was undertaken to determine the minimum amount of time required to inactivate/sterilize and fix spore preparations from several bacterial species using a universal fixative solution for EM that maintains the ultrastructural integrity of the spores. We show that a solution of 4% paraformaldehyde with 1% glutaraldehyde inactivated spore preparations ofBacillus anthracis,Bacillus cereus,Bacillus megaterium,Bacillus thuringiensis, andClostridium perfringensin 30 min, andBacillus subtilisin 240 min. These results suggest that this fixative solution can be used to inactivate and fix spores from several major groups of bacterial spore formers after 240 min, enabling the fixed preparations to be removed from biocontainment and safely analyzed by EM outside of biocontainment.

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Chen, Weixin, Riming Liu, Suo Tao, Weixing Shen, Weihong Zhou, Chao Song, Huanhua Lu e Chungen Xing. "Ultrastructural Analysis of Human Gallstones using Synchrotron Radiation µCT". Combinatorial Chemistry & High Throughput Screening 22, n. 1 (3 maggio 2019): 13–17. http://dx.doi.org/10.2174/1386207322666190222122007.

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Objective: Gallstone formation is a pathological process of mineralization in the human body. Determination of the morphology and ultrastructure of gallstones holds the key to understanding the pathophysiology of gallbladder disease. Synchrotron radiation phase-contrast Xray microtomography is a novel technology, which is designed for comprehensive analysis of gallstone ultrastructure. Materials and Methods: Nine human gallstones were obtained from the Department of Pathology, Qingpu branch of Zhongshan Hospital Affiliated to Fudan University (China), and scanned by synchrotron radiation µCT (SR µCT). The imaging data generated by SR µCT scan were analyzed. Results: The three-dimensional ultrastructure of human gallstones corresponding to their cholesterol and bile pigment composition was determined. Conclusions: The ultrastructure of gallstones exhibits considerable diversity and complexity. The synchrotron radiation phase-contrast X-ray microtomography is a valuable tool for in-depth study of human gallstones.

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Jiao, Lin, Jue Wang e Lingling Zhu. "A Comparative Study of Endometriosis and Normal Endometrium Based on Ultrasound Observation". Applied Bionics and Biomechanics 2022 (30 aprile 2022): 1–12. http://dx.doi.org/10.1155/2022/7934690.

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In order to compare the microscopic ultrastructure of eutopic endometrium and normal endometrium in patients with endometriosis, to study the specific pathogenesis of endometriosis. In this paper, on the basis of using B-ultrasound technology, several patients with endometriosis were subjected to B-ultrasound to observe the ultrastructure of the eutopic uterine endometrium and compared with the pictures of normal endometrium to carry out the specific analysis between the two ultrastructural comparisons. This study is based on the analysis of B-ultrasound images of patients with endometriosis, compares the difference between their ultrastructure and normal human body, and conducts specific pathological diagnosis and analysis to find out the impact of the endometrium in place. The specific factors of the occurrence of lesions and the corresponding treatment methods are proposed. The experimental results show that the ultrastructure of endometriosis eutopic endometrium is different from that of normal endometrium. The microvilli of secretory cells and the cilia of ciliated cells of the former are abnormally increased and lengthened, and they are superior to B-ultrasound technology. The success rate of the examination is 93.75%, which can play an important role in the specific examination process of patients with endometriosis, as one of the actual indicators of detection. Under the electron microscope, microvilli are tiny finger-like protrusions extending from the cell membrane and the cytoplasm on the free surface of the cell, surrounded by the cell membrane and perpendicular to the cell membrane surface.

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Burette, Alain C., Thomas Lesperance, John Crum, Maryann Martone, Niels Volkmann, Mark H. Ellisman e Richard J. Weinberg. "Electron tomographic analysis of synaptic ultrastructure". Journal of Comparative Neurology 520, n. 12 (11 giugno 2012): 2697–711. http://dx.doi.org/10.1002/cne.23067.

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Blanco-Máñez, Rosana, Miguel Armengot-Carceller, Teresa Jaijo e Francisco Vera-Sempere. "Axonemal Symmetry Break, a New Ultrastructural Diagnostic Tool for Primary Ciliary Dyskinesia?" Diagnostics 12, n. 1 (6 gennaio 2022): 129. http://dx.doi.org/10.3390/diagnostics12010129.

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Diagnosis testing for primary ciliary dyskinesia (PCD) requires a combination of investigations that includes study of ciliary beat pattern by high-speed video-microscopy, genetic testing and assessment of the ciliary ultrastructure by transmission electron microscopy (TEM). Historically, TEM was considered to be the “gold standard” for the diagnosis of PCD. However, with the advances in molecular genetic techniques, an increasing number of PCD variants show normal ultrastructure and cannot be diagnosed by TEM. During ultrastructural assessment of ciliary biopsies of patients with suspicion of PCD, we observed an axonemal defect not previously described that affects peripheral doublets tilting. To further characterize this defect of unknown significance, we studied the ciliary axonemes by TEM from both PCD-confirmed patients and patients with other sino-pulmonary diseases. We detected peripheral doublets tilting in all the PCD patients, without any significant difference in the distribution of ciliary beat pattern or mutated gene. This defect was also present in those patients with normal ultrastructure PCD subtypes. We believe that the performance of axonemal asymmetry analysis would be helpful to enhance diagnosis of PCD.

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Più fonti

Tesi sul tema "Ultrastructure analysis"

1

Taylor, Wilson A. "Comparative analysis of sporoderm ultrastructure in fossil and extant lycopods /". The Ohio State University, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487599963591563.

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Pratelli, Ambra. "Ultrastructural and immunolocalization studies on the interactions occurring between IntraFlagellar Transport components and the ciliary tip structures during IFT trains turnaround in Chlamydomonas flagella". Doctoral thesis, Università di Siena, 2021. http://hdl.handle.net/11365/1143888.

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Cilia and flagella are dynamic organelles of the eukaryotic cell that undergo cycles of assembly/disassembly, in a manner that is coordinated in time with the cell cycle. Cilia are composed by more than 600 peptides and their turnover occurs at the plus distal end of the axoneme; since these organelles lack the machinery required for protein synthesis, a bidirectional transport process known as the IntraFlagellar Transport (IFT) is required to provide flagellar precursors and remove turnover products. IFT is carried on by macromolecular complexes (the IFT particles) which are arranged in polymers (the IFT trains) in the space between the microtubular doublets and the flagellar membrane. IFT trains operate as platforms for cargoes and are moved bidirectionally by specific molecular motors, kinesin-2 as the anterograde motor and dynein-1b as the retrograde motor. Anterograde and retrograde IFT trains possess distinct architectures but, up to now, a high-resolution 3D-model is available only for the anterograde trains, while much less is known on the ultrastructure of retrograde trains. At the distal tip of the organelle, the anterograde transport (from the cell body up to the ciliary distal end or tip) is converted into the retrograde transport (from the tip back to the cell body). Such a turnaround process is strictly required for the correct functioning of the IFT process. So far, however, very little is known about the morpho-functional organization of the tip district, where IFT turnaround takes place. In particular, nothing is known on the interactions that might occur between IFT proteins and the distal tip structures. This doctoral work has been aimed at contributing new information for the comprehension of the IFT turnaround process in the model organism Chlamydomonas reinhardtii. We started our studies from the observation that thin sections of flat-embedded flagella often show anterograde IFT trains that contact the distal end of the central pair microtubules (CP), suggesting the direct involvement of CP capping structures (terminal plates and the ring above) in the IFT turnaround process. We confirmed the interaction of anterograde trains with the CP distal end by electron-tomographic reconstruction of flat-embedded flagellar tips. This approach revealed that anterograde trains split into three components after having reached the end of the A tubule, with the outer part of the train that remains associated with the membrane, the inner part, closer to the microtubule surface, that continues its travel and bends to contact the CP plates, and an intermediate part that stops before reaching the tip. The latter region was interpreted as the part of the train consisting of inactive dynein-1b, which is known to dissociate from the anterograde train before its activation and recruitment for the retrograde transport. Then, we sought to obtain further information on the ultrastructural organization of the distal CP segment. We were able to identify a ladder-like structure (LLS) which is distinctive of this region, is intercalated between the two CP tubules, and is resistant to the cold treatments used to depolymerize tubulin. In order to confirm the association between IFT anterograde trains and the capping CP structures, whole cells were treated with inhibitors of Ca++-dependent protein kinases before flagellar demembranation and negative staining. These inhibitors block the release of kinesin-2 from the anterograde trains and, consequently, IFT turnaround at the tip. As expected, we observed a massive accumulation of IFT particles around the CP terminus. Successively, we analyzed by immunoelectronmicroscopy the specific distribution of the three protein complexes present within the IFT particles. At this purpose, we carried out a series of immunolabeling experiments on grid-absorbed demembranated cells or on sections of resin-embedded samples, using antibodies directed against subunits of the IFT-A complex (IFT139), and of the two IFT-B subcomplexes IFT-B1 (IFT74 and IFT81) and IFT-B2 (IFT172 and IFT57). Our findings suggest that at the tip the IFT-A complex is closely associated with the membrane. On the contrary, both IFT-B1 and IFT-B2 antibodies labelled the distal CP region, though, interestingly, with distinct spatial distributions. IFT-B2 labeling was restricted to approximately the distal 200 nm-segment of the CP, which contains the LLS, and gold particles were never found more distally, above the terminal plates, while IFT-B1 labeling extend also to the ring. The whole set of immunoelectronmicroscopy data indicates that the IFT-B1 and IFT-B2 subcomplexes differentially interact with the distal CP region and its capping structures, and suggests that the IFT-B1 subcomplex might be a main component of the CP capping structures. Accordingly, in our negatively stained samples the cap was shown to consist of thin elongated elements, frequently with a sort of small knob at their mid region; these elements fit quite well with the available IFT-B 3D model. The possibility that IFT-B1 proteins are involved in the formation of the CP cap was confirmed by the analysis of a series Chlamydomonas mutants with defective IFT, which related the presence of the CP cap to the establishment of a fully cycling IFT process. Our data sustain a model of IFT turnaround in which i) the IFT-A complex turns around quickly, remaining associated with the membrane, ii) IFT-B1 and IFT-B2 follow a more complex pathway, during which they separate and differentially interact with the CP distal segment, iii) IFT-B1 directly contribute to the formation of the CP cap. The LLS component, which is ectopically assembled also in mutant strains devoid of the CP tubules, is likely to act as an anchoring structure for IFT-B2 during IFT turnaround.

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Axelsson, Maria. "Image analysis for volumetric characterisation of microstructure /". Uppsala : Centre for Image Analysis, Swedish University of Agricultural Sciences, 2009. http://epsilon.slu.se/200919.pdf.

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Johnstone, Andrew Fredericks Moser. "PHYSIOLOGICAL AND ANATOMICAL ASSESSMENT OF SYNAPSES AT THE CRAYFISH NEUROMUSCULAR JUNCTION". UKnowledge, 2006. http://uknowledge.uky.edu/gradschool_diss/274.

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The crayfish, Procambarus clarkii, has a multitude of ideal sites in which synaptic transmission may be studied. Its opener muscle, being innervated by a single excitatory neuron is a good model for studying the structure/function of neuromuscular junctions since the preparation is identifiable from animal to animal and the nerve terminals are visible using a vital dye. This allows ease in finding a suitable site to record from in each preparation and offers the ability to relocate it anatomically. Marking a recorded site and rebuilding it through electron microscopy gives good detail of synaptic struture for assesment.In the first of these studies, low output sites known as stems (which lie between varicosities) were used to reduce n (number of release sites) in order to minimize synaptic complexity so individual quantal events could be analyzed by their unique parameters (area, peak, tau, rise time and latency). This was in attempt to uncover specific quantal signatures that could be traced back to the structure of the area recorded. It was found that even at stem regions synaptic structure is still complex having multiple synapses each of which could harbor a number of AZs. This gives insight as to how quantal analysis should be treated. Even low output synapses n must be treated at the AZ level.Synaptic depression was studied at the crayfish extensor muscle. By depressing the phasic neuron and recording from the muscle it appears thatdepression is a presynaptic phenomenon. The use of 5-HT gave insight to vesicular dynamics within the nerve terminal, by delaying depression and increasing maximum EPSP amplitude. TEM of phasic nerve terminals reveals no change in numbers of dock or RRP vesicles. Short term facilitation and vesicular dynamics were studied with the use of 5-HT and a neurotoxin TBOA, which blocks the glutamate transporter. In this study I showed differential mechanisms that control RRP and RP vesicles. By blocking glutamate reuptake, the RRP is depleted as shown by reduced EPSPs, but recovered with 5-HT application. The understanding of vesicle dynamics in any system has relevance for all chemical synapses.

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Gogoli, Komlavi. "Contribution à l'étude des faisceaux de fibres de lin : analyse des relations morphologie-comportement mécanique-ultrastructure". Thesis, Normandie, 2022. https://tel.archives-ouvertes.fr/tel-03789637.

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Afin de réduire l’impact écologique des processus industriels, on assiste à un intérêt croissant dans l’industrie pour les fibres végétales. En effet, en plus d’être biodégradables, ces fibres possèdent des propriétés mécaniques capables de concurrencer celles des fibres synthétiques. Cependant, leur usage est limité notamment par la variabilité de leurs propriétés mécaniques. De plus, ces fibres présentent un comportement mécanique non-linéaire qu’il convient d’élucider. Dans ce contexte, cette thèse se propose dans une première partie d’étudier l’influence de la morphologie des faisceaux de fibres de lin sur leur comportement mécanique. Les résultats révèlent une forte hétérogénéité de la morphologie et une dépendance du comportement mécanique par rapport aux paramètres morphologiques comme le vrillage des échantillons, l’état des lamelles mitoyennes ou la section transversale. Dans une deuxième partie, il est proposé une caractérisation par diffraction des rayons X de l’ultrastructure du lin afin d’améliorer la compréhension du comportement mécanique non-linéaire des fibres de lin. Le traitement des mesures de diffraction par la technique d’analyse combinée << structure/microstructure/texture >> a rendu possible, entre autres, la détermination de la distribution de l’Angle Micro-Fibrillaire et la forme des cristallites de cellulose. Cette méthode a ensuite permis de suivre l’évolution sous traction de l’ultrastructure de la fibre de lin. Nous avons pu ainsi proposer un scénario susceptible d’expliquer le comportement mécanique non-linéaire des fibres de lin
In order to reduce the ecological impact of industrial processes, there is a growing interest in the industry for plant fibres. Indeed, in addition to being biodegradable, these fibres have remarkable mechanical properties, making them very competitive with synthetic fibres. However, the use of plant fibres is currently limited, in particular by the variability observed in their mechanical properties. In addition, these fibres have a non-linear mechanical behaviour that needs to be elucidated. In this context, this work proposes in a first part to study the influence of the morphology of flax fibre bundles on their mechanical behaviour. The results reveal a strong heterogeneity in the morphology and a dependence of the tensile mechanical behaviour on morphological parameters such as the twisting of the samples, the state of the middle lamellae or the cross-section. In a second part, an X-ray diffraction characterisation of the flax ultrastructure is proposed to improve the understanding of the non-linear mechanical behaviour of flax fibres. The use of the so-called combined analysis << structure/microstructure/texture >> approach for the X-ray diffraction data fit allows the determination of the Micro-Fibrillar Angle distribution and the shape of the cellulose crystallites. This method then made it possible to follow the evolution of the ultrastructure of flax fibres under tensile loading. Finally, this allowed us to propose a scenario that could explain the non-linear mechanical behaviour of flax fibres

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Cappello, V. "ANALYSIS OF NEUROMUSCULAR JUNCTIONS AND EFFECTS OF NANDROLONE ADMINISTRATION IN A MOUSE MODEL FOR ALS". Doctoral thesis, Università degli Studi di Milano, 2012. http://hdl.handle.net/2434/170264.

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Several lines of evidence indicate that neuromuscular junction (NMJ) destruction and disassembly is an early phenomenon in the amyotrophic lateral sclerosis (ALS) neurodegenerative disease. Here we analyzed by confocal and electron microscopy the NMJ structure in the diaphragm of Superoxide dismutase (SOD)1 G93A mice at symptom onset and we compared these observation with animals sacrificed at the pathological end stage. In young transgenic mice, which provide a model for familial ALS, the present findings showed marked denervation both in the diaphragm and in the gastrocnemius, which partially spares soleus muscle. At the clinical end stage even the soleus is slight denervated, but less severely than other muscles. In addition, the size of the synaptic vesicle (SV) pool was found reduced and alterations of mitochondria were observed in approximately 40% of the remaining presynaptic terminals. Treatment of SOD1 G93A mice with the anabolic steroid nandrolone during the presymptomatic stage preserved the diaphragm muscle mass and features indicative of synaptic activity, represented by the number of vesicles docked within 200 nm from the presynaptic membrane and area of acetylcholine receptor clusters. Furthermore, structural preservation of mitochondria was documented in presynaptic terminals, but innervation of diaphragm muscle fibers was only slightly increased in nandrolone-treated SOD1-mutant mice. Altogether the results point out and define fine structural alterations of diaphragm NMJs in the murine model of familial ALS at symptom onset, and indicate that nandrolone may prevent or delay structural alterations in NMJ mitochondria and stimulate presynaptic activity but does not prevent muscle denervation in the disease.

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Strassert, Jürgen F. H. [Verfasser]. "The symbioses of termite gut flagellates and their bacterial endo- and ectosymbionts : analysis of ultrastructure, phylogeny, and cospeciation / Jürgen F. H. Strassert". Berlin : Freie Universität Berlin, 2010. http://d-nb.info/1024105148/34.

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Nordin, Anders. "Buellia species with pluriseptate spores and the Physciaceae (Lecanorales, Ascomycotina) : Taxonomic, phylogenetic and ultrastructural studies". Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2001. http://publications.uu.se/theses/91-554-4879-8/.

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Lima, Bruna de Araujo 1985. "Análise dos mecanismos da atividade antimicrobiana da violaceína sobre Staphylococcus aureus = Analysis of antimicrobial activity mechanisms of violacein against Staphylococcus aureus". [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317022.

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Orientador: Marcelo Brocchi
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: A violaceína é um pigmento violeta produzido por algumas espécies bacterianas de origem ambiental, tais como Chromobacterium violaceum e Janthinobacterium lividum. Esta molécula apresenta várias propriedades biológicas incluindo antibacteriana, antifúngica, antiviral, antiprotozoária e antitumoral, apesar de sua função exata na fisiologia dos micro-organismos que a produz, ainda é desconhecido. No presente trabalho, a atividade antimicrobiana da violaceína produzida comercialmente, o extrato semi purificado e nanopartículas de vanadato de prata foram avaliados contra espécies de bacterianas gram-positivas e gram-negativas. A violaceína exibiu efeito antimicrobiano contra Staphylococcus aureus resistente à meticilina (MRSA) e Enterococcus resistente à vancomicina (VRE), que são micro-organismos frequentemente relacionados com infecções adquiridas em hospitais. Os valores de MIC (concentração inibitória mínima) e MBC (concentração bactericida mínima) da violaceína produzida comercialmente foram de 0,625 ?M e 1,25 ?M respectivamente e, análise de curvas de crescimento e tempo-morte revelaram um efeito antibacteriano durante 12 horas contra MRSA. A microscopia eletrônica de transmissão mostrou os efeitos da violaceína com alterações morfológicas e ultra estruturais, incluindo alterações na parede celular e formação de septos de divisão anormais. Nos resultados obtidos das análises de proteômica e transcriptoma a violaceína afetou a expressão de várias classes funcionais de proteínas e genes em MRSA, incluindo processos biológicos em biossíntese da parede celular e divisão celular que corroboram as alterações ultra estruturais visualizadas. Em conclusão, a violaceína produzida comercialmente demonstrou atividade antimicrobiana para S. aureus MRSA e pela primeira vez, os efeitos da violaceína sobre o metabolismo de S. aureus foram descritos, indicando possíveis alvos e vias metabólicas afetadas por esta droga. No seu conjunto, estes dados indicam a violaceína como uma droga potencial para o tratamento de infecções provocadas por MRSA
Abstract: Violacein is a violet pigment produced by some bacterial species of environmental source, such as Chromobacterium violaceum and Janthinobacterium lividum. This molecule has numerous biological properties including antibacterial, antifungal, antiviral, antiprotozoal and antitumor activity, although the exact role in the physiology of producing microorganisms is still unknown. In this study, the antimicrobial activity of violacein produced commercially, semi purified extract and silver vanadate nanoparticles were evaluated against several species of gram-positive and gram-negative bacteria. Violacein exhibited antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE), microorganisms that are often related to hospital-acquired infections. MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) values of violacein produced commercially were 1.25 ?M mM and 0.625 ?M respectively, and analysis of growth and time-kill curves showed an antibacterial effect against MRSA for 12 hours. The transmission electron microscopy showed the effects of violacein with morphological and ultra-structural changes, including changes in cell wall formation and abnormal division septum. The results obtained from the analysis of proteomic and transcriptomic revealed that violacein affects the expression of several functional classes of proteins and genes in MRSA, including biological processes in cell wall biosynthesis and cell division, supporting ultra-structural changes. In conclusion, violacein produced commercially demonstrated antimicrobial activity against S. aureus MRSA and the effects on the metabolism of S. aureus have been described, indicating possible targets and pathways affected by this drug. These data indicate violacein as a potential drug for the treatment of infections caused by MRSA
Doutorado
Microbiologia
Doutora em Genética e Biologia Molecular

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Moore, Wendy Ann Louise. "The effect of age and caloric restriction on the ultrastructure and pattern of lipofuscin accumulation in granule cells of the dentate gyrus of the hippocampus of C3B10RF1 female mice, a morphometric analysis". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0027/MQ40691.pdf.

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Libri sul tema "Ultrastructure analysis"

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Steinbusch, Hendrik Wilhelm Maria, 1950-, a cura di. Monoaminergic neurons: Light microscopy and ultrastructure. Chichester: Wiley, 1987.

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Cherepova, Nadi͡a Vasileva. Elektronno-mikroskopska enzimot͡sitokhimii͡a pri bakterii. Sofii͡a: Izd-vo na Bŭlgarskata akademii͡a na naukite, 1989.

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Institute of Physics (Great Britain). Electron Microscopy and Analysis Group., a cura di. Electron microscopy and analysis, 1985: Proceedings of the Institute of Physics Electron Microscopy and Analysis Group conference held at the University of Newcastle upon Tyne, 2-5 September 1985 (EMAG 85). Bristol: A. Hilger, 1986.

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Ultrastructural methods for nucleic acid detection by immunocytology. Stuttgart: Gustav Fischer Verlag, 1999.

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Thiry, Marc. Ultrastructural methods for nucleic acid detection by immunocytology. Jena, Germany: Urban & Fischer, 1999.

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Biological microarrays: Methods and protocols. New York: Humana Press, 2011.

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P, Young Malcolm. The analysis of cortical connectivity. New York: Springer, 1995.

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-P, Leung L. K., a cura di. Fish evolution and systematics: Evidence from spermatozoa : with a survey of lophophorate, echinoderm, and protochordate sperm and an account of gamete cryopreservation. Cambridge: Cambridge University Press, 1991.

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Khademhosseini, Ali, Kahp-Yang Suh e Mohammed Zourob. Biological microarrays: Methods and protocols. New York: Humana Press, 2011.

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J, Quinn Peter, e Cherry Richard J, a cura di. Structural and dynamic properties of lipids and membranes. London: Portland Press, 1992.

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Capitoli di libri sul tema "Ultrastructure analysis"

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Stewart, Murray. "Computer Analysis of Ordered Microbiological Objects". In Ultrastructure Techniques for Microorganisms, 333–64. Boston, MA: Springer US, 1986. http://dx.doi.org/10.1007/978-1-4684-5119-1_12.

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Smit, John, e William J. Todd. "Colloidal Gold Labels for Immunocytochemical Analysis of Microbes". In Ultrastructure Techniques for Microorganisms, 469–516. Boston, MA: Springer US, 1986. http://dx.doi.org/10.1007/978-1-4684-5119-1_17.

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Albertini, David F., Rise Auerbach, Cecilia Tsao e Debra Gervais. "Digital Image Analysis Studies of Folliculogenesis and Oogenesis in Mammals". In Ultrastructure of the Ovary, 91–100. Boston, MA: Springer US, 1991. http://dx.doi.org/10.1007/978-1-4615-3944-5_6.

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Zoller, Lawrence C. "Quantitative Analysis of the Membrana Granulosa in Developing and Ovulatory Follicles". In Ultrastructure of the Ovary, 73–89. Boston, MA: Springer US, 1991. http://dx.doi.org/10.1007/978-1-4615-3944-5_5.

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Todd, Mary E. "Smooth muscle cell characteristics: a computer-assisted analysis from serial sections". In Ultrastructure of Smooth Muscle, 101–17. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4613-0683-2_5.

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Bell, B. J., L. A. Brako, B. R. Jones e W. V. Dashek. "A Comparative Fixation Analysis of Tetrahymena Pyriformis Ultrastructure". In Mycotoxins, Wood Decay, Plant Stress, Biocorrosion, and General Biodeterioration, 437–53. Boston, MA: Springer US, 1994. http://dx.doi.org/10.1007/978-1-4757-9450-2_34.

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Rusche, M. L., e H. L. Mogensen. "The Male Germ Unit of Zea mays: Quantitative Ultrastructure and Three-Dimensional Analysis". In Sexual Reproduction in Higher Plants, 221–26. Berlin, Heidelberg: Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/978-3-642-73271-3_35.

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Matise, Ilze, Theerapol Sirinarumitr, Brad T. Bosworth e Harley W. Moon. "Ultrastructure and DNA Fragmentation Analysis of Arterioles in Swine Infected with Shiga Toxin-Producing Escherichia Coli". In Mechanisms in the Pathogenesis of Enteric Diseases 2, 163–71. Boston, MA: Springer US, 1999. http://dx.doi.org/10.1007/978-1-4615-4143-1_15.

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Imig, Cordelia, e Benjamin H. Cooper. "3D Analysis of Synaptic Ultrastructure in Organotypic Hippocampal Slice Culture by High-Pressure Freezing and Electron Tomography". In Methods in Molecular Biology, 215–31. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-6688-2_15.

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Richard McIntosh, J., Eileen O’Toole, Cynthia Page e Garry Morgan. "Ultrastructural Analysis of Microtubule Ends". In Methods in Molecular Biology, 191–209. New York, NY: Springer US, 2019. http://dx.doi.org/10.1007/978-1-0716-0219-5_13.

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Atti di convegni sul tema "Ultrastructure analysis"

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Syyong, Harley T., Abdul Raqeeb, Peter D. Pare e Chun Y. Seow. "Morphometric Quantification And Analysis Of Asthmatic Airway Smooth Muscle Ultrastructure". In American Thoracic Society 2012 International Conference, May 18-23, 2012 • San Francisco, California. American Thoracic Society, 2012. http://dx.doi.org/10.1164/ajrccm-conference.2012.185.1_meetingabstracts.a3579.

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Fire, Andrew. "RNAi, genome ultrastructure, and other unexpected tales from the analysis of genetic silencing". In the eighth annual international conference. New York, New York, USA: ACM Press, 2004. http://dx.doi.org/10.1145/974614.974646.

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Vrca, Ivana. "Ultrastructure analysis of plant tissue leaves of Brassica juncea L. and Tropaeolum majus L. by TEM". In European Microscopy Congress 2020. Royal Microscopical Society, 2021. http://dx.doi.org/10.22443/rms.emc2020.1193.

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Chen, Duanduan, Kyosuke Shinohara, Jun Ren e Hiroshi Hamada. "The Protein-Driven Ciliary Motility in Embryonic Nodes: A Computational Model of Ciliary Ultrastructure". In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-62460.

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Abstract (sommario):

The movement of embryonic cilia presents a crucial function in specifying left-right axis for vertebrates. Those mono-cilia are primary (9+0) cilia, whose characteristic architecture is based on a cylindrical arrangement of 9 microtubule doublets. Dynein motors located between adjacent doublets convert the chemical energy of ATP hydrolysis into mechanical work that induces doublet sliding. Passive components, such as the mediated cytoplasm, the ciliary membrane, and other possibly-existent structures constraint the ciliary motion and maintain the cilia structural integrity, thus resulting in the axonemal bending. Dynein motors located along microtubule doublets in a motile nodal cilium activate in a sequential manner. However, due to inherent difficulties, the dynein activation patterns in moving cilia can hardly be directly observed. The exact mechanism that controls ciliary motion is still unrevealed. In this work, we present a protein-structure model reconstructed from transmission electron microscopy image set of a wide-type embryonic cilium to study the dynein-dependent ciliary motility. This model includes time accurate three-dimensional solid mechanics analysis of the sliding between adjacent microtubule doublets and their induced ciliary bending. As a conceptual test, the mathematical model provides a platform to investigate various assumptions of dynein activity, which facilitates us to evaluate their rationality and to propose the most possible dynein activation pattern. The proposed protein-trigger pattern can reproduce the rotation-like ciliary motion as observed by experiments. Further application of this approach to mutant cilia with ultrastructural modifications also shows consistency to experimental observations. This computational model based on solid mechanics analysis may improve our understandings regarding the protein-beating problems of cilia, and may guide and inspire further experimental investigations on this topic.

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Ford, T. W. "Development and evaluation of cryo-imaging of unicellular algae using soft X-ray transmission microscopy: Ultrastructure and elemental analysis". In Sixth international conference on x-ray microscopy (XRM99). AIP, 2000. http://dx.doi.org/10.1063/1.1291128.

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Fornaini, Carlo, Francesca Passaretti, Elena Villa, Samir Nammour e Leonardo Longo. "Intraoral Laser Welding (ILW): ultrastructural and mechanical analysis". In LASER FLORENCE 2009: A Gallery Through the Laser Medicine World. AIP, 2010. http://dx.doi.org/10.1063/1.3453773.

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MISRA, MANOJ, e K. ANANTHAPADMANABHAN. "QUANTITATIVE ANALYSIS OF SURFACTANT INDUCED ULTRASTRUCTURAL CHANGES IN SKIN LIPIDS". In Proceedings of the Fifth Royal Society–Unilever Indo-UK Forum in Materials Science and Engineering. A CO-PUBLICATION OF IMPERIAL COLLEGE PRESS AND THE ROYAL SOCIETY, 2000. http://dx.doi.org/10.1142/9781848160163_0012.

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Richter, Susanne. "Ultrastructural analysis of callitrichid hepatitis in captive marmosets and tamarins". In European Microscopy Congress 2020. Royal Microscopical Society, 2021. http://dx.doi.org/10.22443/rms.emc2020.195.

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Hayirli, Emine Nazli. "Stereologic and ultrastructural analysis of amniotic membrane covering for sciatic nerve repair". In 15th International Congress of Histochemistry and Cytochemistry. Istanbul: LookUs Scientific, 2017. http://dx.doi.org/10.5505/2017ichc.pp-202.

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Fornaini, Carlo, Elisabetta Merigo, Federica Poli, Jean-Paul Rocca, Stefano Selleri e Annamaria Cucinotta. "Ultrastructural analysis of dental ceramic surface processed by a 1070 nm fiber laser". In Laser Florence 2017: Advances in Laser Medicine, a cura di Leonardo Longo. SPIE, 2018. http://dx.doi.org/10.1117/12.2319449.

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Rapporti di organizzazioni sul tema "Ultrastructure analysis"

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Solomon, J. A., R. E. Jr Hand e R. C. Mann. Ultrastructural and flow cytometric analyses of lipid accumulation in microalgae. Office of Scientific and Technical Information (OSTI), dicembre 1986. http://dx.doi.org/10.2172/6757339.

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Norton, William N. Acute Exposure of Medaka to Carcinogens: An Ultrastructural, Cytochemical and Morphometric Analysis of Liver and Kidney. Fort Belvoir, VA: Defense Technical Information Center, febbraio 1991. http://dx.doi.org/10.21236/ada242950.

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