Hyperalgesia: An increased sensation of pain or discomfort produced by mimimally noxious stimuli due to damage to soft tissue containing NOCICEPTORS or injury to a peripheral nerve.Stress, Mechanical: A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.Mechanical Processes: The behaviors of materials under force.Biomechanical Phenomena: The properties, processes, and behavior of biological systems under the action of mechanical forces.Mechanical Phenomena: The properties and processes of materials that affect their behavior under force.Respiration, Artificial: Any method of artificial breathing that employs mechanical or non-mechanical means to force the air into and out of the lungs. Artificial respiration or ventilation is used in individuals who have stopped breathing or have RESPIRATORY INSUFFICIENCY to increase their intake of oxygen (O2) and excretion of carbon dioxide (CO2).Mechanotransduction, Cellular: The process by which cells convert mechanical stimuli into a chemical response. It can occur in both cells specialized for sensing mechanical cues such as MECHANORECEPTORS, and in parenchymal cells whose primary function is not mechanosensory.Elasticity: Resistance and recovery from distortion of shape.Physical Stimulation: Act of eliciting a response from a person or organism through physical contact.Tensile Strength: The maximum stress a material subjected to a stretching load can withstand without tearing. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed, p2001)Elastic Modulus: Numerical expression indicating the measure of stiffness in a material. It is defined by the ratio of stress in a unit area of substance to the resulting deformation (strain). This allows the behavior of a material under load (such as bone) to be calculated.Ventilators, Mechanical: Mechanical devices used to produce or assist pulmonary ventilation.IsraelEritrea: A country of eastern Africa, west of the Red Sea, bordered west and northwest by SUDAN, and south by ETHIOPIA. Its capital is Asmara.Motorcycles: Two-wheeled, engine-driven vehicles.United StatesFats: The glyceryl esters of a fatty acid, or of a mixture of fatty acids. They are generally odorless, colorless, and tasteless if pure, but they may be flavored according to origin. Fats are insoluble in water, soluble in most organic solvents. They occur in animal and vegetable tissue and are generally obtained by boiling or by extraction under pressure. They are important in the diet (DIETARY FATS) as a source of energy. (Grant & Hackh's Chemical Dictionary, 5th ed)Tooth Preparation: Procedures carried out with regard to the teeth or tooth structures preparatory to specified dental therapeutic and surgical measures.Wireless Technology: Techniques using energy such as radio frequency, infrared light, laser light, visible light, or acoustic energy to transfer information without the use of wires, over both short and long distances.Publications: Copies of a work or document distributed to the public by sale, rental, lease, or lending. (From ALA Glossary of Library and Information Science, 1983, p181)Computer Communication Networks: A system containing any combination of computers, computer terminals, printers, audio or visual display devices, or telephones interconnected by telecommunications equipment or cables: used to transmit or receive information. (Random House Unabridged Dictionary, 2d ed)Telemetry: Transmission of the readings of instruments to a remote location by means of wires, radio waves, or other means. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Congresses as Topic: Conferences, conventions or formal meetings usually attended by delegates representing a special field of interest.Semiconductors: Materials that have a limited and usually variable electrical conductivity. They are particularly useful for the production of solid-state electronic devices.Sodium Hypochlorite: It is used as an oxidizing and bleaching agent and as a disinfectant. (From Grant & Hackh's Chemical Dictionary, 5th ed)Patents as Topic: Exclusive legal rights or privileges applied to inventions, plants, etc.Colloids: Two-phase systems in which one is uniformly dispersed in another as particles small enough so they cannot be filtered or will not settle out. The dispersing or continuous phase or medium envelops the particles of the discontinuous phase. All three states of matter can form colloids among each other.Silicon Dioxide: Transparent, tasteless crystals found in nature as agate, amethyst, chalcedony, cristobalite, flint, sand, QUARTZ, and tridymite. The compound is insoluble in water or acids except hydrofluoric acid.Crystallization: The formation of crystalline substances from solutions or melts. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Iron Carbonyl Compounds: Complex of iron atoms chelated with carbonyl ions.Cytoskeleton: The network of filaments, tubules, and interconnecting filamentous bridges which give shape, structure, and organization to the cytoplasm.Cell Nucleus: Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Yoga: A major orthodox system of Hindu philosophy based on Sankhya (metaphysical dualism) but differing from it in being theistic and characterized by the teaching of raja-yoga as a practical method of liberating the self. It includes a system of exercises for attaining bodily or mental control and well-being with liberation of the self and union with the universal spirit. (From Webster, 3d ed)Chromatin: The material of CHROMOSOMES. It is a complex of DNA; HISTONES; and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell.Stress, Physiological: The unfavorable effect of environmental factors (stressors) on the physiological functions of an organism. Prolonged unresolved physiological stress can affect HOMEOSTASIS of the organism, and may lead to damaging or pathological conditions.Stress, Psychological: Stress wherein emotional factors predominate.Mortality, Premature: Deaths that occur before LIFE EXPECTANCY is reached within a given population.Restraint, Physical: Use of a device for the purpose of controlling movement of all or part of the body. Splinting and casting are FRACTURE FIXATION.Syndecan-4: A ubiquitously expressed syndecan that is found in all stages of embryonic development and in most adult tissues. Syndecan-4 is found localized to focal adhesion sites in fibronectin-adherent cells and may play a role the process of CELL MIGRATION and CELL PROLIFERATION.Myofibroblasts: Spindle-shaped cells with characteristic CONTRACTILE PROTEINS and structures that contribute to the WOUND HEALING process. They occur in GRANULATION TISSUE and also in pathological processes such as FIBROSIS.Syndecan-1: A syndecan that interacts with EXTRACELLULAR MATRIX PROTEINS and plays a role CELL PROLIFERATION and CELL MIGRATION.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Syndecan-2: A syndecan that is predominantly expressed during EMBRYONIC DEVELOPMENT. It may play a role in mediating cellular interactions with the EXTRACELLULAR MATRIX and may modulate the signaling activity of certain INTERCELLULAR SIGNALING PEPTIDES AND PROTEINS.Fibroblasts: Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.Finite Element Analysis: A computer based method of simulating or analyzing the behavior of structures or components.Microtechnology: Manufacturing technology for making microscopic devices in the micrometer range (typically 1-100 micrometers), such as integrated circuits or MEMS. The process usually involves replication and parallel fabrication of hundreds or millions of identical structures using various thin film deposition techniques and carried out in environmentally-controlled clean rooms.Micro-Electrical-Mechanical Systems: A class of devices combining electrical and mechanical components that have at least one of the dimensions in the micrometer range (between 1 micron and 1 millimeter). They include sensors, actuators, microducts, and micropumps.Nanowires: Nanometer-scale wires made of materials that conduct electricity. They can be coated with molecules such as antibodies that will bind to proteins and other substances.Epithelioid Cells: Characteristic cells of granulomatous hypersensitivity. They appear as large, flattened cells with increased endoplasmic reticulum. They are believed to be activated macrophages that have differentiated as a result of prolonged antigenic stimulation. Further differentiation or fusion of epithelioid cells is thought to produce multinucleated giant cells (GIANT CELLS).Computer Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.

Insulin-like growth factor-1 induces Mdm2 and down-regulates p53, attenuating the myocyte renin-angiotensin system and stretch-mediated apoptosis. (1/9460)

Insulin-like growth factor (IGF)-1 inhibits apoptosis, but its mechanism is unknown. Myocyte stretching activates p53 and p53-dependent genes, leading to the formation of angiotensin II (Ang II) and apoptosis. Therefore, this in vitro system was used to determine whether IGF-1 interfered with p53 function and the local renin-angiotensin system (RAS), decreasing stretch-induced cell death. A single dose of 200 ng/ml IGF-1 at the time of stretching decreased myocyte apoptosis 43% and 61% at 6 and 20 hours. Ang II concentration was reduced 52% at 20 hours. Additionally, p53 DNA binding to angiotensinogen (Aogen), AT1 receptor, and Bax was markedly down-regulated by IGF-1 via the induction of Mdm2 and the formation of Mdm2-p53 complexes. Concurrently, the quantity of p53, Aogen, renin, AT1 receptor, and Bax was reduced in stretched myocytes exposed to IGF-1. Conversely, Bcl-2 and the Bcl-2-to-Bax protein ratio increased. The effects of IGF-1 on cell death, Ang II synthesis, and Bax protein were the consequence of Mdm2-induced down-regulation of p53 function. In conclusion, the anti-apoptotic impact of IGF-1 on stretched myocytes was mediated by its capacity to depress p53 transcriptional activity, which limited Ang II formation and attenuated the susceptibility of myocytes to trigger their endogenous cell death pathway.  (+info)

Fibrocartilage in tendons and ligaments--an adaptation to compressive load. (2/9460)

Where tendons and ligaments are subject to compression, they are frequently fibrocartilaginous. This occurs at 2 principal sites: where tendons (and sometimes ligaments) wrap around bony or fibrous pulleys, and in the region where they attach to bone, i.e. at their entheses. Wrap-around tendons are most characteristic of the limbs and are commonly wider at their point of bony contact so that the pressure is reduced. The most fibrocartilaginous tendons are heavily loaded and permanently bent around their pulleys. There is often pronounced interweaving of collagen fibres that prevents the tendons from splaying apart under compression. The fibrocartilage can be located within fascicles, or in endo- or epitenon (where it may protect blood vessels from compression or allow fascicles to slide). Fibrocartilage cells are commonly packed with intermediate filaments which could be involved in transducing mechanical load. The ECM often contains aggrecan which allows the tendon to imbibe water and withstand compression. Type II collagen may also be present, particularly in tendons that are heavily loaded. Fibrocartilage is a dynamic tissue that disappears when the tendons are rerouted surgically and can be maintained in vitro when discs of tendon are compressed. Finite element analyses provide a good correlation between its distribution and levels of compressive stress, but at some locations fibrocartilage is a sign of pathology. Enthesis fibrocartilage is most typical of tendons or ligaments that attach to the epiphyses of long bones where it may also be accompanied by sesamoid and periosteal fibrocartilages. It is characteristic of sites where the angle of attachment changes throughout the range of joint movement and it reduces wear and tear by dissipating stress concentration at the bony interface. There is a good correlation between the distribution of fibrocartilage within an enthesis and the levels of compressive stress. The complex interlocking between calcified fibrocartilage and bone contributes to the mechanical strength of the enthesis and cartilage-like molecules (e.g. aggrecan and type II collagen) in the ECM contribute to its ability to withstand compression. Pathological changes are common and are known as enthesopathies.  (+info)

Receptor mechanisms underlying heterogenic reflexes among the triceps surae muscles of the cat. (3/9460)

The soleus (S), medial gastrocnemius (MG), and lateral gastrocnemius (LG) muscles of the cat are interlinked by rapid spinal reflex pathways. In the decerebrate state, these heterogenic reflexes are either excitatory and length dependent or inhibitory and force dependent. Mechanographic analysis was used to obtain additional evidence that the muscle spindle primary ending and the Golgi tendon organ provide the major contributions to these reflexes, respectively. The tendons of the triceps surae muscles were separated and connected to independent force transducers and servo-controlled torque motors in unanesthetized, decerebrate cats. The muscles were activated as a group using crossed-extension reflexes. Electrical stimulation of the caudal cutaneous sural nerve was used to provide a particularly strong activation of MG and decouple the forces of the triceps surae muscles. During either form of activation, the muscles were stretched either individually or in various combinations to determine the strength and characteristics of autogenic and heterogenic feedback. The corresponding force responses, including both active and passive components, were measured during the changing background tension. During activation of the entire group, the excitatory, heterogenic feedback linking the three muscles was found to be strongest onto LG and weakest onto MG, in agreement with previous results concerning the strengths of heteronymous Ia excitatory postsynaptic potentials among the triceps surae muscles. The inhibition, which is known to affect only the soleus muscle, was dependent on active contractile force and was detected essentially as rapidly as length dependent excitation. The inhibition outlasted the excitation and was blocked by intravenous strychnine. These results indicate that the excitatory and inhibitory effects are dominated by feedback from primary spindle receptors and Golgi tendon organs. The interactions between these two feedback pathways potentially can influence both the mechanical coupling between ankle and knee.  (+info)

Glycoprotein (GP) Ib-IX-transfected cells roll on a von Willebrand factor matrix under flow. Importance of the GPib/actin-binding protein (ABP-280) interaction in maintaining adhesion under high shear. (4/9460)

Adhesion of platelets to sites of vascular injury is critical for hemostasis and thrombosis and is dependent on the binding of the vascular adhesive protein von Willebrand factor (vWf) to the glycoprotein (GP) Ib-V-IX complex on the platelet surface. A unique but poorly defined characteristic of this receptor/ligand interaction is its ability to support platelet adhesion under conditions of high shear stress. To examine the structural domains of the GPIb-V-IX complex involved in mediating cell adhesion under flow, we have expressed partial (GPIb-IX), complete (GPIb-V-IX), and mutant (GPIbalpha cytoplasmic tail mutants) receptor complexes on the surface of Chinese hamster ovary (CHO) cells and examined their ability to adhere to a vWf matrix in flow-based adhesion assays. Our studies demonstrate that the partial receptor complex (GPIb-IX) supports CHO cell tethering and rolling on a bovine or human vWf matrix under flow. The adhesion was specifically inhibited by an anti-GPIbalpha blocking antibody (AK2) and was not observed with CHO cells expressing GPIbbeta and GPIX alone. The velocity of rolling was dependent on the level of shear stress, receptor density, and matrix concentration and was not altered by the presence of GPV. In contrast to selectins, which mediate cell rolling under conditions of low shear (20-200 s-1), GPIb-IX was able to support cell rolling at both venous (150 s-1) and arterial (1500-10,500 s-1) shear rates. Studies with a mutant GPIbalpha receptor subunit lacking the binding domain for actin-binding protein demonstrated that the association of the receptor complex with the membrane skeleton is not essential for cell tethering or rolling under low shear conditions, but is critical for maintaining adhesion at high shear rates (3000-6000 s-1). These studies demonstrate that the GPIb-IX complex is sufficient to mediate cell rolling on a vWf matrix at both venous and arterial levels of shear independent of other platelet adhesion receptors. Furthermore, our results suggest that the association between GPIbalpha and actin-binding protein plays an important role in enabling cells to remain tethered to a vWf matrix under conditions of high shear stress.  (+info)

Cloning of a stretch-inhibitable nonselective cation channel. (5/9460)

A homologue of the capsaicin receptor-nonselective cation channel was cloned from the rat kidney to investigate a mechanosensitive channel. We found this channel to be inactivated by membrane stretch and have designated it stretch-inactivated channel (SIC). SIC encodes a 563-amino acid protein with putative six transmembrane segments. The cDNA was expressed in mammalian cells, and electophysiological studies were performed. SIC-induced large cation currents were found to be regulated by cell volume, with currents being stimulated by cell shrinkage and inhibited by cell swelling. Single channel analysis showed a conductance of 250 pS with cation permeability (PCl/PNa < 0.1), and the channel possessed some of the characteristics of a stretch-inactivated channel in that it was permeable to calcium, sensitive to membrane stretch, and blocked by Gd3+. Therefore, we cloned one of the mechanosensitive cation channels of mammals, which is considered to regulate Ca2+ influx in response to mechanical stress on the cell membrane.  (+info)

Distinct structural attributes regulating von Willebrand factor A1 domain interaction with platelet glycoprotein Ibalpha under flow. (6/9460)

We have used recombinant von Willebrand factor (vWF) fragments to investigate the properties regulating A1 domain interaction with platelet glycoprotein (GP) Ibalpha. One fragment, rvWF508-704, represented the main portion of domain A1 (mature subunit residues 497-716) within the Cys509-Cys695 disulfide loop. The other, rvWF445-733, included the carboxyl-terminal region of domain D3, preceding A1, and corresponded to the proteolytic fragment originally identified as the GP Ibalpha-binding site (residues 449-728). Conformational changes were induced by reduction and alkylation of the Cys509-Cys695 bond and/or exposure to acidic pH. The cyclic rvWF445-733 fragment exhibited the function of native vWF A1 domain. When immobilized onto a surface, it tethered platelets at shear rates up to 6,300 s-1 mediating low velocity translocation but not stable attachment; in solution, it exhibited limited interaction with GP Ibalpha. In contrast, fragments with perturbed conformation could not tether platelets at high shear rates but promoted stable adhesion at lower shear and bound tightly to GP Ibalpha. Only in the presence of the exogenous modulator, botrocetin, did cyclic rvWF445-733 mediate irreversible adhesion. Thus, conformational transitions in the vWF A1 domain may influence differentially the efficiency of bond formation with GP Ibalpha and the stability of binding.  (+info)

Calculation of a Gap restoration in the membrane skeleton of the red blood cell: possible role for myosin II in local repair. (7/9460)

Human red blood cells contain all of the elements involved in the formation of nonmuscle actomyosin II complexes (V. M. Fowler. 1986. J. Cell. Biochem. 31:1-9; 1996. Curr. Opin. Cell Biol. 8:86-96). No clear function has yet been attributed to these complexes. Using a mathematical model for the structure of the red blood cell spectrin skeleton (M. J. Saxton. 1992. J. Theor. Biol. 155:517-536), we have explored a possible role for myosin II bipolar minifilaments in the restoration of the membrane skeleton, which may be locally damaged by major mechanical or chemical stress. We propose that the establishment of stable links between distant antiparallel actin protofilaments after a local myosin II activation may initiate the repair of the disrupted area. We show that it is possible to define conditions in which the calculated number of myosin II minifilaments bound to actin protofilaments is consistent with the estimated number of myosin II minifilaments present in the red blood cells. A clear restoration effect can be observed when more than 50% of the spectrin polymers of a defined area are disrupted. It corresponds to a significant increase in the spectrin density in the protein free region of the membrane. This may be involved in a more complex repair process of the red blood cell membrane, which includes the vesiculation of the bilayer and the compaction of the disassembled spectrin network.  (+info)

The forward rate of binding of surface-tethered reactants: effect of relative motion between two surfaces. (8/9460)

The reaction of molecules confined to two dimensions is of interest in cell adhesion, specifically for the reaction between cell surface receptors and substrate-bound ligand. We have developed a model to describe the overall rate of reaction of species that are bound to surfaces under relative motion, such that the Peclet number is order one or greater. The encounter rate between reactive species is calculated from solution of the two-dimensional convection-diffusion equation. The probability that each encounter will lead to binding depends on the intrinsic rate of reaction and the encounter duration. The encounter duration is obtained from the theory of first passage times. We find that the binding rate increases with relative velocity between the two surfaces, then reaches a plateau. This plateau indicates that the increase in the encounter rate is counterbalanced by the decrease in the encounter duration as the relative velocity increases. The binding rate is fully described by two dimensionless parameters, the Peclet number and the Damkohler number. We use this model to explain data from the cell adhesion literature by incorporating these rate laws into "adhesive dynamics" simulations to model the binding of a cell to a surface under flow. Leukocytes are known to display a "shear threshold effect" when binding selectin-coated surfaces under shear flow, defined as an increase in bind rate with shear; this effect, as calculated here, is due to an increase in collisions between receptor and ligand with increasing shear. The model can be used to explain other published data on the effect of wall shear rate on the binding of cells to surfaces, specifically the mild decrease in binding within a fixed area with increasing shear rate.  (+info)

  • Citation Query Focal contacts as mechanosensors: externally applied local mechanical force induces growth of focal contacts by an mDia1-dependent and ROCK-independent mechanism. (psu.edu)
  • I have conducted a couple of experiments to demonstrate that there is less mechanical stress in the radial approach as compared to the axial approach but I would like to prove this concept mathematically (at a basic level). (physicsforums.com)
  • Can someone out there please explain the basic math principles that show why an axial turbine will have more mechanical stresses than a radial turbine? (physicsforums.com)
  • A key player in this process is an ion channel in the skin's inner cell membranes that was only discovered seven years ago: Piezo2 responds to mechanical stimuli by opening when the cell membrane surrounding it expands. (eurekalert.org)
  • Until now, the assumption was that Piezo1 and Piezo2 reacted solely to mechanical stimuli - perhaps because of the unique structure of the two ion channels, which is fundamentally different to that of classical voltage-gated channels. (eurekalert.org)
  • When the membrane voltage is normal, which in most cells is ?60 mV, around 95 percent of all the Piezo channels are closed and remain closed even when exposed to mechanical stimuli," explains Lewin. (eurekalert.org)
  • This importance of voltage regulation is not only demonstrated by the fact that it has clearly existed for well over 100 million years, but Moroni also discovered a mutation in the Piezo1 channels of human blood cells that alters the voltage dependence of these ion channels, making them far more sensitive to changes in the membrane potential and thus more sensitive to mechanical stimuli. (eurekalert.org)
  • His new computer model takes slices of laser confocal microscopy images of cells and reconstructs a whole, virtual version of an individual cell, allowing researchers to evaluate how that cell will respond to different mechanical stimuli. (medindia.net)
  • This link between EM field exposures and mechanical vibration is consistent with the hypothesis that cells sense these stimuli via a similar mechanism involving counter ion displacement. (nih.gov)
  • The role of mechanical stimuli in airway remodelling has been hypothesized by Tschumperlin and Drazen more than a decade ago [ 2 ]. (hindawi.com)
  • The profibrotic environment produced by mechanical stress applied to the airway epithelial cells, in the absence of any inflammatory response, demonstrated the role of mechanical stimuli in airway remodelling [ 2 ]. (hindawi.com)
  • 1 2 The exact mechanism by which trabecular outflow tissues sense and respond to different types of mechanical stimuli (i.e., elevated intraocular pressure, circadian rhythm, ocular pulse, shear flow) is not well understood. (arvojournals.org)
  • The response of plants to mechanical stimuli can also be more discrete without any apparent overt changes. (biomedcentral.com)
  • This disparity has led to our hypothesis that chondrocyte proliferation is accelerated by mechanical stimuli above natural growth. (semanticscholar.org)
  • Although mechanical stimuli are essential for the chondrocyte metabolism, excessive mechanical force contributes to the release of inflammatory mediators leading the cartilage destruction under the arthritic condition. (biomedcentral.com)
  • According to our knowledge, this is the first comprehensive review on participation of plant GRPs in the response to diverse stress stimuli. (frontiersin.org)
  • The data indicate that there was not much difference in the damage levels between high and low metastatic sub-lines and that a considerable fraction of stressed cells were not lethally damaged even at bulk shear stresses as high as 900 dynes/cm$\sp2$ for 5 min. (rice.edu)
  • In particular, we show that the temporal correlation function of shear stresses can be used to define an effective tissue viscosity that diverges at the liquid-solid transition. (pnas.org)
  • The state of the art shows a substantial knowledge deficit about the influence of the volumetric grinding wheel composition and the resulting grinding wheel topography on the thermo-mechanical stress collective acting on the workpiece external zone. (mdpi.com)
  • Therefore, the aim of the current research is an empirical-analytical model for the prediction of the thermo-mechanical stress collective as a function of the grinding wheel topography. (mdpi.com)
  • The obtained results are summarized and are used to explain the thermo-mechanical stress collective as a function of the grinding wheel topography. (mdpi.com)
  • Here we show that the pattern of branching morphogenesis of three-dimensional (3D) engineered epithelial tissues is controlled in part by gradients of endogenous mechanical stress. (nih.gov)
  • Branches initiated from sites of high mechanical stress within the tissues, as predicted numerically and measured directly using 3D traction force microscopy. (nih.gov)
  • These data suggest that the pattern and magnitude of mechanical stress across epithelial tissues cooperate with biochemical signals to specify branching pattern. (nih.gov)
  • According to Prof. Gefen, applying mechanical loads on tissues can affect many different cells within our bodies. (medindia.net)
  • When we stress our body in our yoga practice, we obviously stress our tissues. (yinyoga.com)
  • Our tissues are made up of cell, so we also stress the cells. (yinyoga.com)
  • Cells and tissues can be protected against a potentially lethal stress by first exposing them to a brief dose of the same or different stress. (nih.gov)
  • Tissues develop their shape through mechanical processes. (biologists.org)
  • Mechanical stress, the internal distribution of forces within cells and tissues, is what make cells move, change shape, or exchange neighbors. (biologists.org)
  • How growth impacts on the distribution of stress and subsequent shaping of tissues is not known. (biologists.org)
  • Our work provides a unifying framework for existing, seemingly distinct notions of stress in tissues and relates stresses to material properties. (pnas.org)
  • Using a self-propelled Voronoi (SPV) model that links cell mechanics to cell shape and cell motility, we formulate a generalized mechanical inference method to obtain the spatiotemporal distribution of cellular stresses from measured traction forces in motile tissues and show that such traction-based stresses match those calculated from instantaneous cell shapes. (pnas.org)
  • To make quantitative predictions for large-scale cell remodeling in tissues, we must understand their material properties, such as stiffness and viscosity, as well as the forces that build up inside them, characterized by local pressures and stresses. (pnas.org)
  • How Mechanical Piping Design can Save You Time, Stress, and Money. (affiliatblogger.com)
  • Mechanical Piping Design is Among the many most highly regarded engineering, challenge management, and building corporations on the globe. (affiliatblogger.com)
  • The detailer will not be typically responsible for design, which include structural strength and integrity (which Mechanical Piping Design happen to be the duty of the structural engineer), key dimensions with the structure and compliance with suitable developing codes (which happen to be the duty of your architect). (affiliatblogger.com)
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  • Mechanical Piping Design is here, with lots of expertise and experience to serve you in all kinds of back end engineering activities. (bloguetechno.com)
  • The local distribution of near-surface stress in Si has been measured, in comparison with stress analysis of the TSV structure based on a semi-analytic approach and finite element analysis. (utexas.edu)
  • Stress concentration factors have been calculated using finite element analysis (FEA). (diva-portal.org)
  • The finite element models of lumbar motion segments were useful in analyzing internal stresses, given segment geometry, material properties and applied loads. (cdc.gov)
  • It was found that the major parameters that influence the generation of internal stresses were the exposure time, the post-baking temperature and time and the concentration of the photo-initiator used (Cyracure UVI). (nsti.org)
  • This is the first time that a mechanical constraint has been shown to influence the genetic control of the development of Drosophila embryo. (innovations-report.com)
  • This aim of the present narrative review was to illustrate the current evidence on the importance of mechanical stress in the pathophysiology of lung diseases with a particular focus on chronic obstructive pulmonary disease (COPD) and to discuss how this may influence pharmacological treatment strategies. (hindawi.com)
  • This narrative review describes the current evidence on the importance of mechanical stress in the pathophysiology of lung diseases and chronic obstructive pulmonary disease (COPD) and discusses how this can influence treatment selection. (hindawi.com)
  • Richardson, P., Davies, M. and Born, G. (1989) Influence of plaque configuration and stress distribution of coronary atherosclerotic plaques. (scirp.org)
  • This is the first handbook containing extensive information on the influence of the stress on the material properties. (begellhouse.com)
  • The influence of the stress mode on the crack growth resistance has been covered in detail. (begellhouse.com)
  • The influence of mechanical forces has undergone minimal investigation to date: multicellular organisms are subject to significantly greater stress than single-celled organisms. (idw-online.de)
  • We show that divisions orient with the long cell axis rather than with the stress direction, and show how oriented divisions contribute to the restoration of cell packing and stress relaxation. (pnas.org)
  • To do this, we used suspended monolayers devoid of ECM, where divisions become oriented following a stretch, allowing the regulation and function of epithelial division orientation in stress relaxation to be characterized. (pnas.org)
  • For transverse motion, mechanical signal transmission is dominated by prestress while fiber elasticity has a negligible effect. (biomedsearch.com)
  • A.N. Parbhu, W.G. Bryson, and R. Lal, Disulfide bonds in theouter layer of keratin fibres confer higher mechanical rigidity:Correlative nano-indentation and elasticity measurement withan AFM, Biochemistry, 38, 1999, 11755-11761. (actapress.com)
  • Cells probably use this ability to protect themselves from mechanical overstimulation, as reported in an article published in the journal Nature Communications initiated and carried out by Dr. Mirko Moroni, the lead author, and other members of Lewin's research group. (eurekalert.org)
  • The mechanism seems to protect blood cells from the mechanical stress they would otherwise be permanently exposed to as they travel through narrow blood vessels. (eurekalert.org)
  • Here we examine how two different cell types, one that undergoes the stress and the other that primarily remodels the matrix, might communicate a mechanical stress by using airway cells as a representative in vitro system. (mendeley.com)
  • When mechanical pressure is applied to the embryo, ß catenin enters the cell nucleus (on right), whereas to perform its role as an "adhesive" between cells it must be on the cell surface. (innovations-report.com)
  • But on applying mechanical pressure to the Drosophila embryo, Emmanuel Farge noted that the Twist gene was then expressed in all the embryo's cells. (innovations-report.com)
  • Henceforth it will be necessary to take into account the mechanical sensitivity of living cells. (innovations-report.com)
  • How fat cells respond to mechanical loads can be studied now through a new method developed by researchers at the Tel Aviv University. (medindia.net)
  • By recreating the structure of fat cells using a newly-developed computer method, Prof. Gefen and his team of researchers can determine how much mechanical load can be tolerated by fat cells, and at what point the cells will begin to disintegrate. (medindia.net)
  • He believes that, much like bone or muscle cells, fat cells are also affected by mechanical loads. (medindia.net)
  • After assembling their "virtual" fat cells, Prof. Gefen and his group found that fat cells or lipids have a point where mechanical loads can disintegrate them, as well as a point at which they are able to resist disintegration. (medindia.net)
  • Cells are constantly adjusting to the mechanical properties of their surroundings, operating a complex mechanochemical feedback, which hinges on mechanotransduction mechanisms. (mdpi.com)
  • This study shows how that stress on the cells can affect gene expression: turning on or off certain genes depending upon the direction and intensity of the stress. (yinyoga.com)
  • The age-effect is reasonable, since younger cells, which are actively shaping their cell walls, are more vulnerable to altered mechanical stresses while in leaves older than 19 DAS, the walls are more robust and therefore can sustain the applied forces. (nih.gov)
  • This process may be triggered by several factors including inflammation, mechanical stress or interaction of cells with certain components of extracellular matrix. (frontiersin.org)
  • The cells were stressed by suspending them in laminar simple shear flows. (rice.edu)
  • Stress effects on tumor cells were studied using high and low metastatic sub-lines of the B16 melanoma and the RAW117 large cell lymphoma. (rice.edu)
  • The cells were stressed at 0, 450 and 900 dynes/cm$\sp2$ at 37$\sp\circ$C for 5 min. (rice.edu)
  • The results could by modeled assuming that a subpopulation of stressed cells was lethally damaged and ultimately died while a second group of stressed cells were only sublethally damaged and grew normally after a brief lag-time. (rice.edu)
  • Although the stresses applied were higher than normally seen in vivo, the results are in contrast to the accepted view that mechanical stresses developed in the circulation directly cause the destruction of most of the tumor cells during blood-borne metastasis and that highly metastatic cells can resist these stresses more effectively than poorly metastatic cells. (rice.edu)
  • The opposite situation is that of loosely connected cells, which can make way for growth, resulting in an effective fluid flow where no mechanical stress is generated, as in cultured multicellular spheroids. (biologists.org)
  • The purpose of the present study was to examine responses of trabecular meshwork (TM) cells to cyclic biomechanical stress in the presence and absence of compounds known to affect cell contractility. (arvojournals.org)
  • Although mechanical stress appeared to have no effect, Y27632 decreased phosphorylated myosin light chain, filamentous/globular actin ratio, and stress fiber formation in TM cells. (arvojournals.org)
  • Mechanical forces exerted on cells impose stress on the plasma membrane. (semanticscholar.org)
  • Cells sense this stress and elicit a mechanoelectric transduction cascade that initiates compensatory mechanisms. (semanticscholar.org)
  • Effects of transient receptor potential canonical 1 (TRPC1) on the mechanical stretch-induced expression of airway remodeling-associated factors in human bronchial epithelioid cells. (semanticscholar.org)
  • In isolated adherent cells, the orientation of mitotic spindles is sensitive to interphase cell shape and the direction of extrinsic mechanical forces. (pnas.org)
  • This article discusses the problem of the turbulent " shear " in biotechnology including the effect of the shear stress on particles (cells, flocs, cells immobilized on microcarriers). (asme.org)
  • Among the bone cells, osteocytes act as a major role in bone remodelling during orthodontic tooth movement against mechanical stress. (elsevier.com)
  • however, is not clear how these cells sense and transmit mechanical signals. (jci.org)
  • A research project by scientists at Kiel University (CAU), the University of Münster (WWU) and Cornell University, USA, is investigating how cells have learned to adapt to mechanical stress to avoid damage during the course of evolution. (idw-online.de)
  • Mechanical pressure on cells also plays a role in illnesses: genetic mutations that alter the mechanical load-bearing capacity of cells can, for example, lead to muscle weakness (muscular dystrophy) and heart disease. (idw-online.de)
  • The fact that cells react to mechanical influences is nothing new in research. (idw-online.de)
  • At the interface between biology and engineering, mechanobiology investigates the mechanical properties of cells and the physical forces at work there. (idw-online.de)
  • In addition to the cellular adaptation strategies that have possibly emerged during the course of evolution, they are also interested in how the mechanical forces in single-celled and multicellular organisms differ and how they are transferred from the surface of the cells to their nucleus. (idw-online.de)
  • Class I, II, and IV members are known to be involved in hormone signaling, stress acclimation, and floral development, and are crucial for regulation of plant cells growth. (frontiersin.org)
  • Fluorescent labeling of cysteines in living cells reveals how mechanical stress can cause force-induced conformational changes in cellular proteins. (sciencemag.org)
  • Mechanical interactions among cells provide an important regulatory mechanism to coordinate such collective motion. (pnas.org)
  • Emmanuel Farge, a researcher at the Institut Curie, lecturer at the Paris VII University, and member of the Institut Universitaire de France, has just shown that mechanical pressure applied to a fly embryo influences the expression of its developmental genes. (innovations-report.com)
  • b catenin could be the link between mechanical pressure and genes. (innovations-report.com)
  • Inflammation and mechanical stress trigger expression of osteogenic genes in VICs in a side-specific manner, while inhibiting the myofibroblastic pathway. (frontiersin.org)
  • The results showed that the stressed plants had stronger antifungal activities and were 'primed' for defense with enhanced expression levels of defense-related genes following fungal inoculation. (hawaii.edu)
  • This was preceded by a rapid change in calcium concentration and a release of ROS, accompanied by changes in cuticle permeability, induction of the expression of genes typically associated with mechanical stress and release of biologically active diffusates from the surface. (biomedcentral.com)
  • Whereas the growth of the cranial base cartilage is thought to be regulated solely by genes, epiphyseal growth plates are known to respond to mechanical stresses. (semanticscholar.org)
  • The cDNA microarray analysis revealed that, of 1080 genes, 37 genes were upregulated and 46 genes were downregulated after mechanical stress. (biomedcentral.com)
  • The new and improved Second Edition contains additional chapters on APDL Math and APDL in ANSYS Mechanical. (padtinc.com)
  • This post shows how Ansys Mechanical does it and offers an alternative that is considered more accurate for some cases. (padtinc.com)
  • Mechanical stress profiles of tubules with increasing contractility: prestress (p t ) that yields prestrain (ε 0 ) of (A) 0.2 % (B) 0.6 % (C) 1% and (D) combined stress profiles. (nih.gov)
  • We identify a motility-induced swim stress that adds to the interaction stress to determine the global contractility or extensibility of epithelia. (pnas.org)
  • However, the mechanisms underlying channel activation in response to mechanical stress remain incompletely understood. (semanticscholar.org)
  • Although the participation of GRPs in plant stress response has been indicated in numerous model and non-model plant species, relatively little is known about the key physiological processes and molecular mechanisms in which those proteins are engaged. (frontiersin.org)
  • To understand the complex mechanisms affecting plant growth and development under stress-inducing conditions, a number of studies on economically and ecologically important species are currently underway. (frontiersin.org)
  • More interestingly, we succeeded in the demonstration of novel mechanical stress sensing by the elastic CLC films of crosslinked HPC derivatives, leading to the visualization of external mechanical stress as the changes in Bragg reflection color. (or.jp)
  • Using a physical model, we demonstrate that stress fibres behave elastic-like, even at timescales exceeding turnover of constituent proteins. (nature.com)
  • In liquids and gases, only deformations that change the volume generate persistent elastic stress. (wikipedia.org)
  • In all this, bone must be as lightweight as possible to decrease the overall body mass yet have the mechanical ability to endure stresses whenever a force is loaded upon them. (scirp.org)
  • however, most modern portable electronic products used in automobiles, personal digital assistants (PDA), and aircraft have to endure extreme environments that involve not only thermal but also mechanical loading conditions. (smta.org)
  • To endure all these stresses, crystalline arrays of cellulose microfibrils are deposited into the wall. (biomedcentral.com)
  • Second, the limitation of conventional Raman measurement is discussed, and two different kinds of innovative Raman measurements have been developed and employed to study the normal stress components separately by taking advantages of different laser polarization configuration. (utexas.edu)
  • Nevertheless, the permeability changes observed during these tests seem to be directly connected to the nature and structure of the material sustains under changes of temperature and stress. (lyellcollection.org)
  • Direct the use of CAEPIPE piping system stress analysis software to determine weight, pressure, temperature, & earthquake. (indeed.com)
  • Direct the use of appropriate piping system stress analysis software (Autopipe, Caesar or similar)to determine weight, pressure, temperature, & earthquake. (indeed.com)
  • Mechanical stress in Arabidopsis leaves orients microtubules in a 'continuous' supracellular pattern. (nih.gov)
  • Confocal microscopy examination of transgenic plants bearing GFP-tagged TUA6 proteins led to the observation that application of an additional mechanical pressure on growing Arabidopsis leaves triggers an excessive bundling of microtubules within the individual cell. (nih.gov)
  • The capacity of the imposition of a mechanical stress (periodic brushing) to reduce the height of the inflorescence stem of Arabidopsis thaliana seedlings has been used to study the role of pectic arabinans in the mechanical properties and stress responsiveness of a plant organ. (whiterose.ac.uk)
  • Arabidopsis can detect and convert gentle forms of mechanical stimulation into a strong activation of defense against the virulent fungus B. cinerea . (biomedcentral.com)
  • The object of this study is to provide evidence for new ways to explore bone's functional adaptation to mechanical stress made through the copious interpretation and integration of new and existing literature. (scirp.org)
  • Here, we review recent advances demonstrating that mechanical stress emanating from the cytoskeleton can activate pathways in the nucleus which eventually impact both its structure and the transcriptional machinery. (mdpi.com)
  • The present results suggest that cytoskeletal prestress mediates rapid mechanical signal transmission and allows temporally oscillatory signals in the physiological frequency range to travel a long distance without significant decay due to material viscosity and/or cytosolic drag. (biomedsearch.com)
  • Administration of stress levels of epinephrine to adrenal medullectomized rats reconstituted the pain phenotype. (pubmedcentralcanada.ca)
  • Based on our studies using a model of intermittent sound stress in rats, we have suggested that sound stress-induced enhancement of immune mediator hyperalgesia requires activity in both neuroendocrine stress axes: the sympathoadrenal (via release of epinephrine) and hypothalamic pituitary adrenal (HPA) (via release of corticosterone) 12 . (pubmedcentralcanada.ca)
  • Stress-induced long-lasting changes in the catecholamine-synthesizing enzymes may contribute to this prolonged elevation of plasma epinephrine levels in sound stressed rats 12 . (pubmedcentralcanada.ca)