Bibliografias temáticas / 42.10 theoretical biology

Índice

Artigos de revistas
Livros
Capítulos de livros
Trabalhos de conferências

Literatura científica selecionada sobre o tema "42.10 theoretical biology"

Autor: Grafiati

Publicado: 4 de junho de 2021

Última modificação: 25 de janeiro de 2023

Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos

Selecione um tipo de fonte:

Consulte a lista de atuais artigos, livros, teses, anais de congressos e outras fontes científicas relevantes para o tema "42.10 theoretical biology".

Ao lado de cada fonte na lista de referências, há um botão "Adicionar à bibliografia". Clique e geraremos automaticamente a citação bibliográfica do trabalho escolhido no estilo de citação de que você precisa: APA, MLA, Harvard, Chicago, Vancouver, etc.

Você também pode baixar o texto completo da publicação científica em formato .pdf e ler o resumo do trabalho online se estiver presente nos metadados.

Artigos de revistas sobre o assunto "42.10 theoretical biology"

Festa, Giulia, Francesco Mallamace, Giulia Maria Sancesario, Carmelo Corsaro, Domenico Mallamace, Enza Fazio, Laura Arcidiacono et al. "Aggregation States of Aβ1–40, Aβ1–42 and Aβp3–42 Amyloid Beta Peptides: A SANS Study". International Journal of Molecular Sciences 20, n.º 17 (24 de agosto de 2019): 4126. http://dx.doi.org/10.3390/ijms20174126.

Texto completo da fonte

Resumo:

Aggregation states of amyloid beta peptides for amyloid beta A β 1 – 40 to A β 1 – 42 and A β p 3 – 42 are investigated through small angle neutron scattering (SANS). The knowledge of these small peptides and their aggregation state are of key importance for the comprehension of neurodegenerative diseases (e.g., Alzheimer’s disease). The SANS technique allows to study the size and fractal nature of the monomers, oligomers and fibrils of the three different peptides. Results show that all the investigated peptides have monomers with a radius of gyration of the order of 10 Å, while the oligomers and fibrils display differences in size and aggregation ability, with A β p 3 – 42 showing larger oligomers. These properties are strictly related to the toxicity of the corresponding amyloid peptide and indeed to the development of the associated disease.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Salazar, Jairo, Joana Poejo, Ana M. Mata, Alejandro K. Samhan-Arias e Carlos Gutierrez-Merino. "Design and Experimental Evaluation of a Peptide Antagonist against Amyloid β(1–42) Interactions with Calmodulin and Calbindin-D28k". International Journal of Molecular Sciences 23, n.º 4 (18 de fevereiro de 2022): 2289. http://dx.doi.org/10.3390/ijms23042289.

Texto completo da fonte

Resumo:

Amyloid β1–42 (Aβ(1–42)) oligomers have been linked to the pathogenesis of Alzheimer’s disease (AD). Intracellular calcium (Ca2+) homeostasis dysregulation with subsequent alterations of neuronal excitability has been proposed to mediate Aβ neurotoxicity in AD. The Ca2+ binding proteins calmodulin (CaM) and calbindin-D28k, whose expression levels are lowered in human AD brains, have relevant roles in neuronal survival and activity. In previous works, we have shown that CaM has a high affinity for Aβ(1–42) oligomers and extensively binds internalized Aβ(1–42) in neurons. In this work, we have designed a hydrophobic peptide of 10 amino acid residues: VFAFAMAFML (amidated-C-terminus amino acid) mimicking the interacting domain of CaM with Aβ (1–42), using a combined strategy based on the experimental results obtained for Aβ(1–42) binding to CaM and in silico docking analysis. The increase in the fluorescence intensity of Aβ(1–42) HiLyteTM-Fluor555 has been used to monitor the kinetics of complex formation with CaM and with calbindin-D28k. The complexation between nanomolar concentrations of Aβ(1–42) and calbindin-D28k is also a novel finding reported in this work. We found that the synthetic peptide VFAFAMAFML (amidated-C-terminus amino acid) is a potent inhibitor of the formation of Aβ(1–42):CaM and of Aβ(1–42):calbindin-D28k complexes.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Shi, Dai, Jaime K. Y. Wong, Kaichuan Zhu, Peter G. Noakes e Gerhard Rammes. "The Anaesthetics Isoflurane and Xenon Reverse the Synaptotoxic Effects of Aβ1–42 on Megf10-Dependent Astrocytic Synapse Elimination and Spine Density in Ex Vivo Hippocampal Brain Slices". International Journal of Molecular Sciences 24, n.º 2 (4 de janeiro de 2023): 912. http://dx.doi.org/10.3390/ijms24020912.

Texto completo da fonte

Resumo:

It has been hypothesised that inhalational anaesthetics such as isoflurane (Iso) may trigger the pathogenesis of Alzheimer’s disease (AD), while the gaseous anaesthetic xenon (Xe) exhibits many features of a putative neuroprotective agent. Loss of synapses is regarded as one key cause of dementia in AD. Multiple EGF-like domains 10 (MEGF10) is one of the phagocytic receptors which assists the elimination of synapses by astrocytes. Here, we investigated how β-amyloid peptide 1–42 (Aβ1–42), Iso and Xe interact with MEGF10-dependent synapse elimination. Murine cultured astrocytes as well as cortical and hippocampal ex vivo brain slices were treated with either Aβ1–42, Iso or Xe and the combination of Aβ1–42 with either Iso or Xe. We quantified MEGF10 expression in astrocytes and dendritic spine density (DSD) in slices. In brain slices of wild type and AAV-induced MEGF10 knock-down mice, antibodies against astrocytes (GFAP), pre- (synaptophysin) and postsynaptic (PSD95) components were used for co-localization analyses by means of immunofluorescence-imaging and 3D rendering techniques. Aβ1–42 elevated pre- and postsynaptic components inside astrocytes and decreased DSD. The combined application with either Iso or Xe reversed these effects. In the presence of Aβ1–42 both anaesthetics decreased MEGF10 expression. AAV-induced knock-down of MEGF10 reduced the pre- and postsynaptic marker inside astrocytes. The presented data suggest Iso and Xe are able to reverse the Aβ1–42-induced enhancement of synaptic elimination in ex vivo hippocampal brain slices, presumably through MEGF10 downregulation.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Hemmerová, Erika, Tomáš Špringer, Zdeňka Krištofiková e Jiří Homola. "Ionic Environment Affects Biomolecular Interactions of Amyloid-β: SPR Biosensor Study". International Journal of Molecular Sciences 21, n.º 24 (20 de dezembro de 2020): 9727. http://dx.doi.org/10.3390/ijms21249727.

Texto completo da fonte

Resumo:

In early stages of Alzheimer’s disease (AD), amyloid beta (Aβ) accumulates in the mitochondrial matrix and interacts with mitochondrial proteins, such as cyclophilin D (cypD) and 17β-hydroxysteroid dehydrogenase 10 (17β-HSD10). Multiple processes associated with AD such as increased production or oligomerization of Aβ affect these interactions and disbalance the equilibrium between the biomolecules, which contributes to mitochondrial dysfunction. Here, we investigate the effect of the ionic environment on the interactions of Aβ (Aβ1–40, Aβ1–42) with cypD and 17β-HSD10 using a surface plasmon resonance (SPR) biosensor. We show that changes in concentrations of K+ and Mg2+ significantly affect the interactions and may increase the binding efficiency between the biomolecules by up to 35% and 65% for the interactions with Aβ1–40 and Aβ1–42, respectively, in comparison with the physiological state. We also demonstrate that while the binding of Aβ1–40 to cypD and 17β-HSD10 takes place preferentially around the physiological concentrations of ions, decreased concentrations of K+ and increased concentrations of Mg2+ promote the interaction of both mitochondrial proteins with Aβ1–42. These results suggest that the ionic environment represents an important factor that should be considered in the investigation of biomolecular interactions taking place in the mitochondrial matrix under physiological as well as AD-associated conditions.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Snezhkina, Anastasiya V., Dmitry V. Kalinin, Vladislav S. Pavlov, Elena N. Lukyanova, Alexander L. Golovyuk, Maria S. Fedorova, Elena A. Pudova et al. "Immunohistochemistry and Mutation Analysis of SDHx Genes in Carotid Paragangliomas". International Journal of Molecular Sciences 21, n.º 18 (22 de setembro de 2020): 6950. http://dx.doi.org/10.3390/ijms21186950.

Texto completo da fonte

Resumo:

Carotid paragangliomas (CPGLs) are rare neuroendocrine tumors often associated with mutations in SDHx genes. The immunohistochemistry of succinate dehydrogenase (SDH) subunits has been considered a useful instrument for the prediction of SDHx mutations in paragangliomas/pheochromocytomas. We compared the mutation status of SDHx genes with the immunohistochemical (IHC) staining of SDH subunits in CPGLs. To identify pathogenic/likely pathogenic variants in SDHx genes, exome sequencing data analysis among 42 CPGL patients was performed. IHC staining of SDH subunits was carried out for all CPGLs studied. We encountered SDHx variants in 38% (16/42) of the cases in SDHx genes. IHC showed negative (5/15) or weak diffuse (10/15) SDHB staining in most tumors with variants in any of SDHx (94%, 15/16). In SDHA-mutated CPGL, SDHA expression was completely absent and weak diffuse SDHB staining was detected. Positive immunoreactivity for all SDH subunits was found in one case with a variant in SDHD. Notably, CPGL samples without variants in SDHx also demonstrated negative (2/11) or weak diffuse (9/11) SDHB staining (42%, 11/26). Obtained results indicate that SDH immunohistochemistry does not fully reflect the presence of mutations in the genes; diagnostic effectiveness of this method was 71%. However, given the high sensitivity of SDHB immunohistochemistry, it could be used for initial identifications of patients potentially carrying SDHx mutations for recommendation of genetic testing.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Kosznik-Kwaśnicka, Katarzyna, Łukasz Grabowski, Michał Grabski, Mateusz Kaszubski, Marcin Górniak, Agata Jurczak-Kurek, Grzegorz Węgrzyn e Alicja Węgrzyn. "Bacteriophages vB_Sen-TO17 and vB_Sen-E22, Newly Isolated Viruses from Chicken Feces, Specific for Several Salmonella enterica Strains". International Journal of Molecular Sciences 21, n.º 22 (21 de novembro de 2020): 8821. http://dx.doi.org/10.3390/ijms21228821.

Texto completo da fonte

Resumo:

Two newly discovered bacteriophages, isolated from chicken feces and infecting Salmonella enterica strains, are described in this report. These phages have been named vB_Sen-TO17 and vB_Sen-E22, and we present their molecular and functional characterization. Both studied viruses are able to infect several S. enterica strains and develop lytically, but their specific host ranges differ significantly. Electron microscopic analyses of virions have been performed, and full genome sequences were determined and characterized, along with molecular phylogenetic studies. Genomes of vB_Sen-TO17 (ds DNA of 41,658 bp) and vB_Sen-E22 (dsDNA of 108,987 bp) are devoid of homologs of any known or putative gene coding for toxins or any other proteins potentially deleterious for eukaryotic cells. Both phages adsorbed efficiently (>95% adsorbed virions) within 10 min at 42 °C (resembling chicken body temperature) on cells of most tested host strains. Kinetics of lytic development of vB_Sen-TO17 and vB_Sen-E22, determined in one-step growth experiments, indicated that development is complete within 30–40 min at 42 °C, whereas burst sizes vary from 9 to 79 progeny phages per cell for vB_Sen-TO17 and from 18 to 64 for vB_Sen-E22, depending on the host strain. Virions of both phages were relatively stable (from several percent to almost 100% survivability) under various conditions, including acidic and alkaline pH values (from 3 to 12), temperatures from −80 °C to 60 °C, 70% ethanol, chloroform, and 10% DMSO. These characteristics of vB_Sen-TO17 and vB_Sen-E22 indicate that these phages might be considered in further studies on phage therapy, particularly in attempts to eliminate S. enterica from chicken intestine.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Morroni, Fabiana, Giulia Sita, Agnese Graziosi, Eleonora Turrini, Carmela Fimognari, Andrea Tarozzi e Patrizia Hrelia. "Protective Effects of 6-(Methylsulfinyl)hexyl Isothiocyanate on Aβ1-42-Induced Cognitive Deficit, Oxidative Stress, Inflammation, and Apoptosis in Mice". International Journal of Molecular Sciences 19, n.º 7 (18 de julho de 2018): 2083. http://dx.doi.org/10.3390/ijms19072083.

Texto completo da fonte

Resumo:

Alzheimer’s disease (AD) is the most common form of dementia among older people. Although soluble amyloid species are recognized triggers of the disease, no therapeutic approach is able to stop it. 6-(Methylsulfinyl)hexyl isothiocyanate (6-MSITC) is a major bioactive compound in Wasabia japonica, which is a typical Japanese pungent spice. Recently, in vivo and in vitro studies demonstrated that 6-MSITC has several biological properties. The aim of the present study was to investigate the neuroprotective activity of 6-MSITC in a murine AD model, induced by intracerebroventricular injection of β-amyloid oligomers (Aβ1-42O). The treatment with 6-MSITC started 1 h after the surgery for the next 10 days. Behavioral analysis showed that 6-MSITC ameliorated Aβ1-42O-induced memory impairments. The decrease of glutathione levels and increase of reactive oxygen species in hippocampal tissues following Aβ1-42O injection were reduced by 6-MSITC. Moreover, activation of caspases, increase of inflammatory factors, and phosphorylation of ERK and GSK3 were inhibited by 6-MSITC. These results highlighted an interesting neuroprotective activity of 6-MSITC, which was able to restore a physiological oxidative status, interfere positively with Nrf2-pathway, decrease apoptosis and neuroinflammation and contribute to behavioral recovery. Taken together, these findings demonstrated that 6-MSITC could be a promising complement for AD therapy.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Brückmann, Roberto, Margret Tuchscherer, Armin Tuchscherer, Ulrike Gimsa e Ellen Kanitz. "Early-Life Maternal Deprivation Predicts Stronger Sickness Behaviour and Reduced Immune Responses to Acute Endotoxaemia in a Pig Model". International Journal of Molecular Sciences 21, n.º 15 (23 de julho de 2020): 5212. http://dx.doi.org/10.3390/ijms21155212.

Texto completo da fonte

Resumo:

Early-life adversity may have programming effects on neuroendocrine and immune adaptation mechanisms in humans and socially living animals. Using a pig model, we investigated the effect of daily 2-h maternal and littermate deprivation from postnatal days 2–15, either alone (DA) or in a group of littermates (DG) on the neuroendocrine, immunological and behavioural responses of piglets challenged with the bacterial endotoxin lipopolysaccharide (LPS) on day 42. LPS increased plasma concentrations of cortisol, tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10) and induced typical signs of sickness in all piglets. DA+DG piglets showed stronger signs of sickness compared to control (C) piglets. Plasma TNF-α concentrations were significantly lower in DA+DG males. In addition, the TNF-α/IL-10 ratio was significantly lower in DA than in DG and C males. Gene expression analyses showed lower hypothalamic TNF-α mRNA expression and diminished mRNA expression of the mineralocorticoid receptor (MR) and IL-10 in the amygdala of DA+DG piglets in response to LPS. Interestingly, males showed a higher MR- and a lower IL-10 mRNA expression in the amygdala than females. The present data suggest that repeated maternal deprivation during early life may alter neuroendocrine and immune responses to acute endotoxaemia in a sex-specific manner.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Zięba, Sebastian, Anne-Floor W. Pouwer, Artur Kowalik, Kamil Zalewski, Natalia Rusetska, Elwira Bakuła-Zalewska, Janusz Kopczyński, Johanna M. A. Pijnenborg, Joanne A. de Hullu e Magdalena Kowalewska. "Somatic Mutation Profiling in Premalignant Lesions of Vulvar Squamous Cell Carcinoma". International Journal of Molecular Sciences 21, n.º 14 (10 de julho de 2020): 4880. http://dx.doi.org/10.3390/ijms21144880.

Texto completo da fonte

Resumo:

Vulvar squamous cell carcinoma (VSCC) originates from the progression of either a high-grade squamous intraepithelial lesion (HSIL) or differentiated-type vulvar intraepithelial neoplasia (dVIN), often in a background of lichen sclerosus (LS). The mechanisms leading to the progression of these premalignant lesions to VSCC are elusive. This study aims to identify pathogenic mutations implicated in VSCC development. Using next-generation sequencing, 38 HSIL, 19 dVIN, 20 LS, of which 10 were solitary lesions and 10 with adjacent VSCC, and 10 VSCC adjacent to LS, were screened for hotspot mutations in 50 genes covered by the Ion AmpliSeq Cancer Hotspot Panel v2 Kit (Thermo Fisher Scientific). Pathogenic mutations of TP53 were the most common genetic alterations identified in 53% and 24% of dVIN and HSIL cases, respectively, followed by CDKN2A (p16) mutated in 42% and 0% of dVIN and HSIL, respectively. Seven (70%) and three (30%) of 10 cases of VSCC associated with LS carried TP53 and CDKN2A mutations, respectively, whereas neither solitary LS nor LS associated with VSCC cases harbored mutations in these genes. It appears that TP53 mutations are early events during VSCC carcinogenesis, being present in both HSIL and dVIN lesions. Our preliminary data do not support a genetic background for the notion of LS as the VSCC premalignant lesion.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Fernández, Marta S., Ricardo Mejía e Eunice Zavala. "The interfacial calcium ion concentration as modulator of the latency phase in the hydrolysis of dimyristoylphosphatidylcholine liposomes by phospholipase A2". Biochemistry and Cell Biology 69, n.º 10-11 (1 de outubro de 1991): 722–27. http://dx.doi.org/10.1139/o91-108.

Texto completo da fonte

Resumo:

Analysis of the time course of hydrolysis of dimyristoylphosphatidylcholine liposomes catalyzed by porcine pancreatic phospholipase A2 at 18 °C shows that, in the presence of 10 mM NaCl, the length of the latency period in the presteady-state phase increases from 3 to 10.5 min when the CaCl2 concentration is reduced from 15 to 1 mM. This inverse dependence of the lag period on calcium ion concentration is seen more readily at 1 M NaCl, where the induction time changes from 13.5 to 42 min by decreasing the concentration of CaCl2 from 15 to 1 mM. To interpret these results, we took into account the small amount of fatty acid that is produced during the latency phases. The fatty acid generates a negative surface electrostatic potential and makes the interfacial concentration of calcium ions different from the concentration in the bulk solvent. Variations in the analytical concentrations of NaCl and CaCl2 affect both the interfacial calcium ion concentration and electrostatic potential, as estimated theoretically from Grahame and Boltzmann equations. According to these estimates, the length of the latency period diminishes with the increase of the interfacial calcium concentration, but does not show any logical dependence on the change in surface electrostatic potential.Key words: phospholipase A2, latency phase, interfacial calcium ion concentration, liposomes.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Mais fontes

Livros sobre o assunto "42.10 theoretical biology"

Jonoska, Nataša. DNA Computing: 7th International Workshop on DNA-Based Computers, DNA7 Tampa, FL, USA, June 10-13, 2001 Revised Papers. Berlin, Heidelberg: Springer-Verlag Berlin Heidelberg, 2006.

Encontre o texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Siemion, Fajtlowicz, e DIMACS (Group), eds. Graphs and discovery: DIMACS working group, computer-generated conjectures from graph theoretical and chemical databases, November 12-16, 2001, DIMACS Center, CoRE Building, Rutgers University : DIMACS public event, graph theory day 42, November 10, 2001, DIMACS Center, CoRE Building, Rutgers University. Providence, RI: American Mathematical Society, 2005.

Encontre o texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Georgescu, A., C. Rocsoreanu e N. Giurgiteanu. The FitzHugh-Nagumo Model - Bifurcation and Dynamics (MATHEMATICAL MODELLING: THEORY AND APPLICATIONS Volume 10). Springer, 2000.

Encontre o texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Гордиевский, Валентин Леонидович. Личное бессмертие как научный факт. Второе издание, дополненное. Publishing House Triumph, 2022. http://dx.doi.org/10.32986/978-5-94472-108-2-10-2022.

Texto completo da fonte

Resumo:

The book presents and classifies objective facts about the phenomena in our world of conscious actions of people who have left it. Among them are the phenomena of materialization, messages in a lifetime handwriting, automatic drawing in the style of outstanding artists of past eras, and more. For the first time, these facts are given a systematic theoretical explanation using the positions of physics, psychology, biology and computer science recognized by modern science. The phenomenon of "tukdam" is explained. The conclusion is made about the proven correspondence of the phenomenon of personal deathlessness to the status of a scientific fact.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Capítulos de livros sobre o assunto "42.10 theoretical biology"

Broom, Mark, e Jan Rychtář. "Extensive form games and other concepts in game theory". In Game-Theoretical Models in Biology, 195–214. 2^a ed. Boca Raton: Chapman and Hall/CRC, 2022. http://dx.doi.org/10.1201/9781003024682-10.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Chen, Bohang. "A Historico-Logical Re-assessment of Hans Driesch’s Vitalism". In History, Philosophy and Theory of the Life Sciences, 49–65. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-12604-8_4.

Texto completo da fonte

Resumo:

AbstractToday vitalism is widely dismissed as a metaphysical heresy. For instance, Brigandt and Love (Reductionism in biology. In: Zalta EN (ed) The stanford encyclopedia of philosophy, 2017) claimed that “the denial of physicalism by vitalism, the doctrine that biological systems are governed by forces that are not physico-chemical, is largely of historical interest” (p. 3). Perhaps the most “infamous” vitalist is the German biologist Hans Driesch. However, Driesch (In Rádl E (ed) Actes du Huitième Congrès International de Philosophie a Prague 2–7 septembre 1934. Comité d’Organisation du Congrès, Prague, pp 10–30, 1936) himself very explicitly stated that his vitalism is “neither ‘mysticism’[…]nor ‘metaphysics’” (p. 27). So, in order to address the mismatch between the present conception of vitalism and his own, I seek to offer a historico-logical re-assessment of Driesch’s vitalism. From the historical point of view, I show that Driesch had provided long ignored theoretical reflections on the nature of entelechy (the central concept in his vitalism), especially those in relation to evolution and physics. From the logical point of view, following logical empiricists (Phillipp Frank and Rudolf Carnap), I indicate that Driesch’s vitalism should be rejected due to its lack of vital laws, at least with respect to current biology; it is an unestablished theory rather than a metaphysical heresy. Ironically, some current theoretical biologists have proposed similar theories (or principles and laws) of life, even though they (incoherently) reject Driesch’s vitalism. In the end, I briefly conclude that the failure of vitalism actually alludes to the fact that even today we understand very little about the nature of life (I mean, the pure concept/phenomenon of life!) (While I cannot elaborate here, it is of extremely importance not to conflate knowledge about the pure concept/phenomenon of life and knowledge about objects predicatable of life (Ben-Naim, manuscript, p. 281). For instance, it is common among philosophers of biology today to cite elementary knowledge in a particular biological discipline as offering a better understanding of life. Yet their promise fails to be delivered. At best, they are merely relying on knowledge about objects predicatable of life (in most cases, merely knowledge about complex organizations of matter: about heredity, reproduction, development, metabolism, etc); but such knowledge has not been shown of any relevance to the pure concept/phenomenon of life).

Estilos ABNT, Harvard, Vancouver, APA, etc.

"Bohm's Metaphysics and Biology". In Sketching Theoretical Biology, 69–79. Routledge, 2017. http://dx.doi.org/10.4324/9781315129358-10.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

"Matrix games". In Game-Theoretical Models in Biology, 119–46. Chapman and Hall/CRC, 2013. http://dx.doi.org/10.1201/b14069-10.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

De, Rumi, Assaf Zemel e Samuel A. Safran. "Theoretical Concepts and Models of Cellular Mechanosensing". In Methods in Cell Biology, 143–75. Elsevier, 2010. http://dx.doi.org/10.1016/s0091-679x(10)98007-2.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Trabalhos de conferências sobre o assunto "42.10 theoretical biology"

Gudym, A. A. "Theoretical and legal aspects of the criminal proceedings". In SCIENCE OF RUSSIA: TARGETS AND GOALS. LJournal, 2019. http://dx.doi.org/10.18411/sr-10-06-2019-42.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Haghshenas-Jaryani, Mahdi, Nguyen T. Tran, Alan P. Bowling, James A. Drake e Samarendra Mohanty. "Multiscale Modeling and Simulation of a Microbead in an Optical Trapping Process". In ASME 2013 2nd Global Congress on NanoEngineering for Medicine and Biology. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/nemb2013-93059.

Texto completo da fonte

Resumo:

The purpose of this work is to generate a theoretical model for the dynamics of a polystyrene microsphere under the influence of Gaussian beam optical tweezers (OTs) in the ray-optics regime. OTs use the radiation pressure from a focused laser beam to manipulate microscopic objects as small as atoms [1]. They have been used in the biological sciences to measure nanometer-range displacements, apply picoNewton-range forces, and determine the mechanical properties of DNA, cell membranes, whole cells, and microtubules. The proposed model takes into account the forces and moments imparted onto the microbead by the OTs beam, and uses a Newton-Euler Dynamics framework to generate the equations of motion. Although examination of dimensionless numbers and other indicators including, Reynolds number 10−9 ≤ Re ≤ 10−4, Knudsen number 0.0001875, and the disproportionality between the mass and the viscous drag co-efficients O(10−4), does not clearly indicate whether this is a multiscale problem or not; but, a numerical integration of the original model leads to a long simulation run-time, a few days. Moreover, investigation of the step size showed that the adaptive numerical integrator was proceeding with a picosecond step size in order to achieve the requested accuracy. This situation implies a multiscale feature involved in the dynamics of optical trapping process of the small bead. To address this issue, a multiscale model is developed that helps to significantly reduce the simulation run-time and reveals underdamped behavior of the bead. In order to verify the theoretical model, experiments were carried out on a microsphere bead with 1.6μm diameter. A comparison of experimental data and simulation data indicate that this approach closely models microparticle behavior to the accuracy of the experiment under Gaussian beam optical tweezers.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Guo, Q. C., W. Wang, J. Xiao e W. P. Lu. "An Improved Generalized Model for Predicting Frost Growth on a Cold Flat Plate". In 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-22492.

Texto completo da fonte

Resumo:

A generalized quasi-steady and one-dimensional model for predicting the frost growth on flat plate was proposed based on the previous theoretical models. To improve the predicting ability of the current model, a modified semi-empirical correlation for calculating initial condition of frost density was presented experimentally. The experiments were conducted in a suction-type open-loop wind tunnel under a series of experimental conditions: air temperature −8°C to 19°C, humidity 42% to 80%, velocity 5m/s and the temperature of cold plate −16°C to −8°C. The numerical results of frost thickness, frost density, frost surface temperature and heat flux rate were compared to the experimental data. The simulation results were found agree with the experimental results in a maximum error of 10%. The presented model was further validated by comparing with the previous published experimental data in a wide range of frosting conditions. It was found that the presented model was a simple but universal one to predict the frost growth on cold flat plate.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Mu¨ller-Steinhagen, Hans. "From Megawatt to Gigawatt: New Developments in Concentrating Solar Thermal Power". In 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-23411.

Texto completo da fonte

Resumo:

On October 30th 2009, a major industrial consortium initiated the so-called DESERTEC project which aims at providing by 2050 15% of the European electricity from renewable energy sources in North Africa, while at the same time securing energy, water, income and employment for this region. In the heart of this concept are solar thermal power plants which can provide affordable, reliable and dispatchable electricity. While this technology has been known for about 100 years, new developments and market introduction programs have recently triggered world-wide activities leading to the present project pipeline of 8.5 GW and 42 billion Euro. To become competitive with mid-load electricity from conventional power plants within the next 10–15 years, mass production of components, increased plant size and planning/operating experience will be accompanied by technological innovations which are presently in the development or even demonstration stage. The scale of construction, the high temperatures and the naturally transient operation provide formidable challenges for academic and industrial R&D. Experimental and theoretical research involving all mechanisms of heat transfer and fluid flow is required together with large-scale demonstration to resolve the combined challenges of performance and cost.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Karaefe, Renan Emre, Pascal Post, Francesca di Mare, Valerius Venzik, Paul Wotzka, Dirk Müller e Riley B. Barta. "On Integrated Fluid Screening and Turbomachinery Design for Optimized Industrial Heat Pumps". In ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/gt2022-79404.

Texto completo da fonte

Resumo:

Abstract This work presents an approach to the contextual integration of fluid selection and compressor design for the cycle design of efficient industrial heat pumps. The vapor-compression cycle of an air-water heat pump operated at 42 °C source and 82 °C target temperature is investigated as a theoretical case study. An optimization study is performed, which includes the assessment of suitable refrigerants. Besides well-known single-component refrigerants, various binary mixtures are considered. The cycle optimization aims at simultaneously providing high cycle coefficient of performance and volumetric heating capacity. Cycle operation with the mixtures R-41/Trans-2-Butene (10, 90 mol%) and CO2/R-161 (40, 60 mol%) yields the highest values of these parameters, respectively. For further evaluation, centrifugal compressors operated with each of the two promising mixtures are designed with an in-house meanline program. In addition, the compressor design for the hydrochlorofluoro-olefin refrigerant R-1234ze(Z) is considered as a reference. All designs are reviewed with respect to cycle as well as compressor design criteria and the applied methodology will assist designers in identifying key decision variables. The comprehensive design assessment suggests that CO2/R-161 provides the best overall solution for an efficient cycle with a compact compressor design.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Adnan, Ashfaq, e Wing Kam Liu. "Electrostatic Self-Assembly of Functionalized Nanodiamonds and Their Binding Capacity With Doxorubicin Drugs". In ASME 2010 First Global Congress on NanoEngineering for Medicine and Biology. ASMEDC, 2010. http://dx.doi.org/10.1115/nemb2010-13164.

Texto completo da fonte

Resumo:

While cancers have no known cure, some of them can be successfully treated with the combination of surgery and systematic therapy. In general, systemic/widespread chemotherapy is usually injected into the bloodstream to attempt to target cancer cells. Such procedure often imparts devastating side effects because cancer drugs are nonspecific in activity, and transporting them throughout the bloodstream further reduces their ability to target the right region. This means that they kill both healthy and unhealthy cells. It has been observed that the physiological conditions of the fluids around living cells can be characterized by pH, and the magnitude of pH around a living cell is different from cancerous cells. Moreover, a multiscale anatomy of carcinoma will reveal that the microstructure of cancer cells contains some characteristic elements such as specific biomarker receptors and DNA molecules that exclusively differentiate them from healthy cells. If these cancer specific ligands can be intercalated by some functional molecules supplied from an implantable patch, then the patch can be envisioned to serve as a complementary technology with current systemic therapy to enhance localized treatment efficiency, minimize excess injections/surgeries, and prevent tumor recurrence. The broader objective of our current research is to capture some fundamental insights of such drug delivery patch system. It is envisioned that the essential components of the device is nanodiamonds (ND), parylene buffer layer and doxorubicin (DOX) drugs. In its simplest form, self-assembled nanodiamonds - functionalized or pristine, and DOX molecules are contained inside parylene capsule. The efficient functioning of the device is characterized by its ability to precisely detect targets (cancer cells) and then to release drugs at a controlled manner. The fundamental science issues concerning the development of the ND-based device include: 1. A precise identification of the equilibrium structure and self assembled morphology of nanodiamonds, 2. Fundamental understanding of the drug adsorption and desorption process to and from NDs, and 3. The rate of drug release through the parylene buffers. The structure of the nanodiamond (ND) is crucial to the adsorption and desorption of drug molecules because it not only changes the self-assembly configuration but also alters the surface electrostatics. To date, the structure and electrostatics of NDs are not yet well understood. A density functional tight binding theory (DFTB) study on smaller [2] NDs suggests a facet dependent charge distributions on ND surfaces. These charges are estimated by Mulliken Analysis [1]. Using the charges for smaller NDs (∼valid for 1–3.3 nm dia ND) we first projected surface charges for larger (4–10 nm) truncated octahedral nanodiamonds (TOND), and it has been found that the [100] face and the [111] face contain positively and negatively charged atoms, respectively. These projected charges are then utilized to obtain the self assembled structure of pristine TONDs from Molecular Dynamics (MD) simulations [4] as shown in Fig. 1. The opposite charges on the [100] and [111] face invoked electrostatic attractions among the initially isolated NDs and a network of nanodiamond agglutinates are formed as evidenced in Fig. 1(b). This study confirms why as manufactured NDs are found in agglomerated form. The study also suggests that a large fraction of ND surfaces become unavailable for drug absorption as many of the [100] faces are coherently connected to [111] faces. As a result, it can be perceived that effective area for drug adsorption on ND surfaces will be less compared to theoretical prediction which suggests that a 4nm TOND may contain as high 360 drug molecules on its surface [5]. It has been observed that as manufactured NDs may contain a variety of functional groups, and currently, we are studying the mechanism of self-assembly for functionalized nanodiamonds so that we understand the role of functional groups. The next phase of calculation involves binding of the DOX to the NDs. Essentially, the understanding of drug absorption and desorption profile at a controlled rate to and from NDs is the most critical part of the device design. Some recent quantum calculation suggests that part of NDs and drug molecules contain opposite charges at their surfaces; it has been a natural interpretation that interactions between ND and drug molecules should be straight-forward — NDs should attract to drugs as soon as they come closure. Recent experiments [6], however, suggest that NDs usually do not interact with drug molecules in the presence of neutral solutions. Addition of NaCl in the solution improves the interaction dramatically. In the first part of the study, we [3–5] have studied the interaction of single DOX molecules with TOND surfaces via MD simulation. As shown in Fig. 2, this study suggests that DOX molecules first arrange them around the preferential sites on nanodiamonds (e.g. around the [111] face) and then spontaneously attach on the surface. It is also observed that only DOX molecule is attached per facets of TONDs. It can be noted that each TOND has 6 [100] face and 8 [111] faces. Figure 3 shows the energy minimization process during the DOX-ND interaction. It can be noted that these simulations have been performed in vacuum environment. In order to see how DOX interacts in solution media, another set of simulations have been conducted where “vacuum” environment have been replaced with solution media of different pH. Moreover, functionalization on the ND surfaces will create a different environment for the DOX molecules. Research is underway to capture the fundamental physics on the DOX loading and release to and from functionalized nanodiamonds. Once we understand the essential physics of drug loading and unloading, in the future we plan to model diffusion controlled drug release through ND coated film device by incorporating the multiscale science learned from the current study. Results from this study will provide fundamental insight on the definitive targeting of infected cells and high resolution controlling of drug molecules.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Oferecemos descontos em todos os planos premium para autores cujas obras estão incluídas em seleções literárias temáticas. Contate-nos para obter um código promocional único!