Search Results
Results 151 - 200 of 1958
1 2 3 4 5 6 7 8 9 10 >
Huang Jia-Yi - - 2011
Iodide adsorption and electrochemical negative potential desorption were proposed and compared to obtain clean SERS substrates. The two methods can effectively eliminate the interference of surface impurities in the SERS detection. SERS signals of membranes of living cells with a good reproducibility have been obtained.
Hornick Jessica E - - 2011
The role of centrosomes and centrioles during mitotic spindle assembly in vertebrates remains controversial. In cell-free extracts and experimentally derived acentrosomal cells, randomly oriented microtubules (MTs) self-organize around mitotic chromosomes and assemble anastral spindles. However, vertebrate somatic cells normally assemble a connected pair of polarized, astral MT arrays--termed an amphiaster ...
Yanagawa Nariaki - - 2011
During axis formation in amniotes, posterior and lateral epiblast cells in the area pellucida undergo a counter-rotating movement along the midline to form primitive streak (Polonaise movements). Using chick blastoderms, we investigated the signaling involved in this cellular movement in epithelial-epiblast. In cultured posterior blastoderm explants from stage X to ...
Xu Lin - - 2011
A novel cell separation and immobilization method for Cr (VI)-reduction under alkaline conditions was developed by using superparamagnetic Fe(3)O(4) nanoparticles (NPs). The Fe(3)O(4) NPs were synthesized by coprecipitation followed by modification with sodium citrate and polyethyleneimine (PEI). The surface-modified NPs were monodispersed and the particle size was about 15nm with ...
Jarrell Ken F - - 2011
Methanococcus maripaludis has two surface appendages, namely flagella and pili. Flagella have been shown to be required for swimming but no specific role has been assigned as yet to pili. In this report, wildtype M. maripaludis cells are compared to mutants lacking either pili or flagella or both surface appendages ...
Monteiro Andrea S - - 2011
This study evaluated the effects of glycolipid-type biosurfactant produced by Trichosporon montevideense CLOA72 in the formation of biofilms in polystyrene plate surfaces by Candida albicans CC isolated from the apical tooth canal. Biofilm formation was reduced up to 87.4% with use of biosurfactant at 16 mg/ml concentration. It has been ...
Ye Ting - - 2011
A miniature microfluidic-microelectric hybrid chip is numerically designed for separation of biological cells, where the characteristic length of the chip is close to the cell radius. A mathematical model is developed to characterize the motion and deformation of a biological cell in the hydrodynamic and nonuniform electric coupled fields, in ...
Sandulescu Corina M - - 2011
In the zebrafish olfactory epithelium, three morphologically distinct olfactory neurons express different marker proteins. We utilize this feature to access developmental dynamics of one of the neuron types, the crypt cells, to determine whether they are differentiated at a stage similar to other olfactory neurons. Immunohistochemical studies using an S100 ...
Li Peng P Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, - - 2011
Cell separation based on microfluidic affinity chromatography is a widely used methodology in cell analysis research when rapid separations with high purity are needed. Several successful examples have been reported with high separation efficiency and purity; however, cell capture at the inlet area and inlet design have not been extensively ...
Thomas Colin R - - 2011
Many cells are considered to be susceptible to mechanical forces or "shear" in bioprocessing, leading to undesirable cell breakage or adverse metabolic effects. However, cell breakage is the aim of some processing operations, in particular high-pressure homogenisation and other cell disruption methods. In either case, the exact mechanisms of damage ...
Koga Hiroshi H Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, - - 2011
Chaperone-mediated autophagy (CMA) is a selective mechanism for the degradation of soluble proteins in lysosomes. CMA contributes to cellular quality control and is activated as part of the cellular response to different stressors. Defective CMA has been identified in ageing and different age-related diseases. Until now, CMA activity could only ...
Quinto-Su Pedro A - - 2011
The deformability of red blood cells (RBCs) is an important property that allows the cells to squeeze through small capillary vessels and can be used as an indicator for disease. We present a microfluidic based technique to quantify the deformability of RBCs by stretching a collection of RBCs on a ...
Banks H T - - 2010
We present a general class of cell population models that can be used to track the proliferation of cells which have been labeled with a fluorescent dye. The mathematical models employ fluorescence intensity as a structure variable to describe the evolution in time of the population density of proliferating cells. ...
Lien Ching-Feng - - 2010
To use computed tomography to determine the association of frontal recess cells with the development of frontal sinusitis. Retrospective analysis. We retrospectively analyzed various frontal recess cells on spiral computed tomographic images of sinuses between November 2007 and May 2009. Exclusion criteria included previous sinus surgery, sinonasal polyposis, age younger ...
Sarvestani Alireza S - - 2011
Mechanical stiffness of bio-adhesive substrates has been recognized as a major regulator of cell motility. We present a simple physical model to study the crawling locomotion of a contractile cell on a soft elastic substrate. The mechanism of rigidity sensing is accounted for using Schwarz's two-spring model Schwarz et al. ...
Picmonova Veronika - - 2012
Unexpected, sometimes opposite effects of dietary isoflavonic phytoestrogens on immunity may suggest that classical mammalian toxicological assays are not entirely suitable for preclinical safety tests of these compounds. We evaluated a new alternative model of haemocytes of Egyptian cotton worm in vivo following genistein administration. Genistein induced significant changes in ...
Janulevicius Albertas - - 2010
Myxobacteria are social bacteria that exhibit a complex life cycle culminating in the development of multicellular fruiting bodies. The alignment of rod-shaped myxobacteria cells within populations is crucial for development to proceed. It has been suggested that myxobacteria align due to mechanical interactions between gliding cells and that cell flexibility ...
Van Haastert Peter J M - - 2010
Many amoeboid cells move by extending pseudopods. Here I present a new stochastic model for chemotaxis that is based on pseudopod extensions by Dictyostelium cells. In the absence of external cues, pseudopod extension is highly ordered with two types of pseudopods: de novo formation of a pseudopod at the cell ...
Park Kidong - - 2010
The characterization of physical properties of cells such as their mass and stiffness has been of great interest and can have profound implications in cell biology, tissue engineering, cancer, and disease research. For example, the direct dependence of cell growth rate on cell mass for individual adherent human cells can ...
Liu Bo - - 2011
We explore one of the best-studied protein circuits in human cells, the negative feedback loop between the tumor suppressor p53 and the oncogene Mdm2 following nuclear irradiation. Using stochastic delay differential equations and the Gillespie algorithm, we illustrate the distinct oscillatory dynamics at the single-cell and population-cell levels which were ...
Hyrien Ollivier O Department of Biostatistics and Computational Biology, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, USA. - - 2010
The adverse effects of chemotherapy on normal cells of the body create substantial clinical problems for many cancer patients. However, relatively little is known about the effects, other than promotion of cell death, of such agents on the function of normal precursor cells critical in tissue homeostasis and repair. We ...
Håkanson Maria - - 2011
Traditional in vitro models used for the development of anti-cancer drugs are based on the monolayer culture of cells, which has a limited predictivity of in vivo efficacy. A number of cell culture platforms have been developed in recent years to improve predictivity and further to elucidate the mechanisms governing ...
Lemmon Christopher A - - 2010
Recent work has indicated that the shape and size of a cell can influence how a cell spreads, develops focal adhesions, and exerts forces on the substrate. However, it is unclear how cell shape regulates these events. Here we present a computational model that uses cell shape to predict the ...
Bandiera Antonella - - 2010
Two synthetic genes that code for artificial proteins have been constructed that were modeled on the most regularly repeated hydrophobic domain of human tropoelastin. We compare the physicochemical properties of the recombinant products that differ in their primary structure; the alanine/lysine-rich cross-linking domains, which are highly conserved in mammalian tropoelastin, ...
Kamaraju Hari - - 2010
Rotary lobe pumps are commonly used in the biotechnology industry for a variety of purposes. Shear damage to animal cells within the rotary lobe pump can adversely affect the product yield or purity during, for example, cell concentration via cross-flow filtration. In this research, CHO cells grown in 20-L bioreactors ...
Munsky B - - 2010
Owing to the inherently random and discrete nature of genes, RNAs and proteins within living cells, there can be a wide range of variability both over time in a single cell and from cell to cell in a population of genetically identical cells. Different mechanisms and reaction rates help shape ...
Haeger J-D - - 2011
Introduction: In this study, we aimed to form spheroids with the bovine placental trophoblast cell line F3. Spheroids are 3-dimensional culture models which can be used to conduct versatile in vitro and in vivo experiments. Materials and Methods: The spheroids were generated using the hanging drop technique, 25% methocel and ...
Fong Eileen - - 2010
The processes of wound healing and collective cell migration have been studied for decades. Intensive research has been devoted to understanding the mechanisms involved in wound healing, but the role of cell-substrate interactions is still not thoroughly understood. Here we probe the role of cell-substrate interactions by examining in vitro ...
Tamulonis Carlos - - 2011
The gastrulation of Nematostella vectensis, the starlet sea anemone, is morphologically simple yet involves many conserved cell behaviors such as apical constriction, invagination, bottle cell formation, cell migration and zippering found during gastrulation in a wide range of more morphologically complex animals. In this article we study Nematostella gastrulation using ...
Neilson Matthew P - - 2010
In this paper we present a computational tool that enables the simulation of mathematical models of cell migration and chemotaxis on an evolving cell membrane. Recent models require the numerical solution of systems of reaction-diffusion equations on the evolving cell membrane and then the solution state is used to drive ...
Ratcliff William C - - 2010
The expression of phenotypic variability can enhance geometric mean fitness and act as a bet-hedging strategy in unpredictable environments. Metazoan bet hedging usually involves phenotypic diversification among an individual's offspring, such as differences in seed dormancy. Virtually all known microbial bet-hedging strategies, in contrast, rely on low-probability stochastic switching of ...
Coskun Hasan - - 2011
Cell motility is an essential phenomenon in almost all living organisms. It is natural to think that behavioral or shape changes of a cell bear information about the underlying mechanisms that generate these changes. Reading cell motion, namely, understanding the underlying biophysical and mechanochemical processes, is of paramount importance. The ...
Or-Tzadikario Shira - - 2011
This communication extends the recently reported cell-specific finite element (FE) method in Slomka and Gefen (2010) in which geometrically realistic FE cell models are created from confocal microscopy scans for large deformation analyses. The cell-specific FE method is extended here in the following aspects: (i) we demonstrate that cell-specific FE ...
Poulos Sylvia P - - 2010
In vitro models have been invaluable in determining the mechanisms involved in adipocyte proliferation, differentiation, adipokine secretion and gene/protein expression. The cells presently available for research purposes all have unique advantages and disadvantages that one should be aware of when selecting cells. Established cell lines, such as 3T3-L1 cells, are ...
Xiong Yuan - - 2010
Cells have an internal compass that enables them to move along shallow chemical gradients. As amoeboid cells migrate, signaling events such as Ras and PI3K activation occur spontaneously on pseudopodia. Uniform stimuli trigger a symmetric response, whereupon cells stop and round up; then localized patches of activity appear as cells ...
Norman Leann L - - 2010
Cells remodel their plasma membrane and cytoskeleton during numerous physiological processes, including spreading and motility. Morphological changes require the cell to adjust its membrane tension on different timescales. While it is known that endo- and exocytosis regulate the cell membrane area in a timescale of 1 h, faster processes, such ...
Wolgemuth Charles W - - 2010
Eukaryotic cell crawling is a highly complex biophysical and biochemical process, where deformation and motion of a cell are driven by internal, biochemical regulation of a poroelastic cytoskeleton. One challenge to building quantitative models that describe crawling cells is solving the reaction-diffusion-advection dynamics for the biochemical and cytoskeletal components of ...
Lidstrom Mary E - - 2010
As the ability to analyze individual cells in microbial populations expands, it is becoming apparent that isogenic microbial populations contain substantial cell-to-cell differences in physiological parameters such as growth rate, resistance to stress and regulatory circuit output. Subpopulations exist that are manyfold different in these parameters from the population average, ...
Huang Yao-Xiong - - 2011
We developed a technique using quantum dot (QD) as a sensor for quantitative visualization of the surface charge on biological cells with nano-scale resolution. The QD system was designed and synthesized using amino modified CdSe/ZnS nanoparticles. In a specially designed buffer solution, they are positively charged and can homogeneously disperse ...
Hillen Thomas - - 2010
Classical expressions for the tumor control probability (TCP) are based on models for the survival fraction of cancer cells after radiation treatment. We focus on the derivation of expressions for TCP from dynamic cell population models. In particular, we derive a TCP formula for a generalized cell population model that ...
Dingli David - - 2010
Cancer is the consequence of sequential acquisition of mutations within somatic cells. Mutations alter the relative reproductive fitness of cells, enabling the population to evolve in time as a consequence of selection. Cancer therapy itself can select for or against specific subclones. Given the large population of tumor cells, subclones ...
Golubev A - - 2010
Several recent experiments related to fundamental aspects of cell behaviour, such as passing of the restriction point of cell cycle, which are generally interpreted in accordance with the dynamic paradigm implying the use of differential equations operating with the concentrations of cellular components and rate constants of their interactions, are ...
Goh Fernie F School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 315 Ferst Dr., Atlanta, GA 30332, - - 2010
Due to the high solubility of oxygen in perfluorocarbons (PFCs), these compounds have been explored for improved cell and tissue oxygenation. The goal of this study is to investigate the effects of a PFC emulsion on cellular growth and function in a tissue engineered construct. A perfluorotributylamine (PFTBA) emulsion was ...
Rolf Julia J Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge, United - - 2010
The generation of high-affinity Abs is essential for immunity and requires collaboration between B and T cells within germinal centers (GCs). By using novel mouse models with a conditional deletion of the p110δ catalytic subunit of the PI3K pathway, we established that p110δ is required in T cells, but not ...
Goodman Rachel M - - 2010
Among ectotherms, individuals raised in cooler temperatures often have larger body size and/or larger cell size. The current study tested whether geographic variation in cell size and plasticity for cell size exist in a terrestrial, ectothermic vertebrate, Anolis carolinensis Voigt, 1832. We demonstrated temperature-induced plasticity in erythrocytes and epithelial cells ...
Barik Debashis D Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, - - 2010
In order for the cell's genome to be passed intact from one generation to the next, the events of the cell cycle (DNA replication, mitosis, cell division) must be executed in the correct order, despite the considerable molecular noise inherent in any protein-based regulatory system residing in the small confines ...
Grote Mathias - - 2010
The term 'cell', in addition to designating fundamental units of life, has also been applied since the nineteenth century to technical apparatuses such as fuel and galvanic cells. This paper shows that such technologies, based on the electrical effects of chemical reactions taking place in containers, had a far-reaching impact ...
Sriyudthsak Kansuporn - - 2010
A number of recent research studies have focused on theoretical and experimental investigation of a bottleneck in a metabolic reaction network. However, there is no study on how the bottleneck affects the performance of a fermentation process when a product is highly toxic and remarkably influences the growth and death ...
Costigliola Nancy - - 2010
When microtubules are depolymerized in spreading cells, they experience morphological oscillations characterized by a period of about a minute, indicating that normal interactions between the microfilament and microtubule systems have been significantly altered. This experimental system provides a test bed for the development of both fine- and coarse-grained models of ...
Turner C - - 2010
Under the cancer stem cell (CSC) hypothesis, sustained metastatic growth requires the dissemination of a CSC from the primary tumour followed by its re-establishment in a secondary site. The epithelial-mesenchymal transition (EMT), a differentiation process crucial to normal development, has been implicated in conferring metastatic ability on carcinomas. Balancing these ...
1 2 3 4 5 6 7 8 9 10 >