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Gravitational biology

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https://www.readbyqxmd.com/read/28431748/a-benchtop-biorobotic-platform-for-in-vitro-observation-of-muscle-tendon-dynamics-with-parallel-mechanical-assistance-from-an-elastic-exoskeleton
#1
Benjamin D Robertson, Siddarth Vadakkeveedu, Gregory S Sawicki
We present a novel biorobotic framework comprised of a biological muscle-tendon unit (MTU) mechanically coupled to a feedback controlled robotic environment simulation that mimics in vivo inertial/gravitational loading and mechanical assistance from a parallel elastic exoskeleton. Using this system, we applied select combinations of biological muscle activation (modulated with rate-coded direct neural stimulation) and parallel elastic assistance (applied via closed-loop mechanical environment simulation) hypothesized to mimic human behavior based on previously published modeling studies...
March 21, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/28417322/are-midge-swarms-bound-together-by-an-effective-velocity-dependent-gravity
#2
Andrew M Reynolds, Michael Sinhuber, Nicholas T Ouellette
Midge swarms are a canonical example of collective animal behaviour where local interactions do not clearly play a major role and yet the animals display group-level cohesion. The midges appear somewhat paradoxically to be tightly bound to the swarm whilst at the same time weakly coupled inside it. The microscopic origins of this behaviour have remained elusive. Models based on Newtonian gravity do, however, agree well with experimental observations of laboratory swarms. They are biologically plausible since gravitational interactions have similitude with long-range acoustic and visual interactions, and they correctly predict that individual attraction to the swarm centre increases linearly with distance from the swarm centre...
April 2017: European Physical Journal. E, Soft Matter
https://www.readbyqxmd.com/read/28397688/engineering-of-a-synthetic-quadrastable-gene-network-to-approach-waddington-landscape-and-cell-fate-determination
#3
Fuqing Wu, Ri-Qi Su, Ying-Cheng Lai, Xiao Wang
The process of cell fate determination has been depicted intuitively as cells travelling and resting on a rugged landscape, which has been probed by various theoretical studies. However, few studies have experimentally demonstrated how underlying gene regulatory networks shape the landscape and hence orchestrate cellular decision-making in the presence of both signal and noise. Here we tested different topologies and verified a synthetic gene circuit with mutual inhibition and auto-activations to be quadrastable, which enables direct study of quadruple cell fate determination on an engineered landscape...
April 11, 2017: ELife
https://www.readbyqxmd.com/read/28287706/nanoparticle-density-a-critical-biophysical-regulator-of-endothelial-permeability
#4
Chor Yong Tay, Magdiel Inggrid Setyawati, David Tai Leong
The integrity of the vasculature system is intrinsically sensitive to a short list of biophysical cues spanning from nano to micro scales. We have earlier found that certain nanomaterials could induce endothelial leakiness (nanoparticle induced endothelial leakiness, nanoEL). In this study, we report that the density of the nanomaterial, a basic intrinsic material property not implicated in many nanoparticle-mediated biological effects, predominantly dictates the nanoEL effect. We demonstrated that the impinging force exerted by a library of increasing effective densities but consistently sized silica nanoparticles (SiNPs) could directly increase endothelial permeability...
March 28, 2017: ACS Nano
https://www.readbyqxmd.com/read/28194160/highlights-in-the-knowledge-of-brown-spider-toxins
#5
REVIEW
Daniele Chaves-Moreira, Andrea Senff-Ribeiro, Ana Carolina Martins Wille, Luiza Helena Gremski, Olga Meiri Chaim, Silvio Sanches Veiga
Brown spiders are venomous arthropods that use their venom for predation and defense. In humans, bites of these animals provoke injuries including dermonecrosis with gravitational spread of lesions, hematological abnormalities and impaired renal function. The signs and symptoms observed following a brown spider bite are called loxoscelism. Brown spider venom is a complex mixture of toxins enriched in low molecular mass proteins (4-40 kDa). Characterization of the venom confirmed the presence of three highly expressed protein classes: phospholipases D, metalloproteases (astacins) and insecticidal peptides (knottins)...
2017: Journal of Venomous Animals and Toxins Including Tropical Diseases
https://www.readbyqxmd.com/read/28125342/edible-nanoemulsions-as-carriers-of-active-ingredients-a-review
#6
Laura Salvia-Trujillo, Robert Soliva-Fortuny, M Alejandra Rojas-Graü, D Julian McClements, Olga Martín-Belloso
There has been growing interest in the use of edible nanoemulsions as delivery systems for lipophilic active substances, such as oil-soluble vitamins, antimicrobials, flavors, and nutraceuticals, because of their unique physicochemical properties. Oil-in-water nanoemulsions consist of oil droplets with diameters typically between approximately 30 and 200 nm that are dispersed within an aqueous medium. The small droplet size usually leads to an improvement in stability, gravitational separation, and aggregation...
February 28, 2017: Annual Review of Food Science and Technology
https://www.readbyqxmd.com/read/28039557/on-the-mechanical-analogue-of-dna
#7
Ludmila Yakushevich
The creation of mechanical analogues of biological systems is known as a useful instrument that helps to understand better the dynamical mechanisms of the functioning of living organisms. Mechanical analogues of biomolecules are usually constructed for imitation of their internal mobility, which is one of the most important properties of the molecules. Among the different types of internal motions, angular oscillations of nitrous bases are of special interest because they make a substantial contribution to the base pairs opening that in turn is an important element of the process of the DNA-protein recognition...
March 2017: Journal of Biological Physics
https://www.readbyqxmd.com/read/27810105/does-the-gravity-orientation-of-saccular-aneurysms-influence-hemodynamics-an-experimental-study-with-and-without-flow-diverter-stent
#8
Kamil J Chodzyński, Omer F Eker, Axel E Vanrossomme, Daniel Ribeiro de Sousa, Grégory Coussement, Luc Vanhamme, Frank Dubois, Alain Bonafé, Bastien Chopard, Guy Courbebaisse, Karim Zouaoui Boudjeltia
Most intracranial aneurysms morphologic studies focused on characterization of size, location, aspect ratio, relationship to the surrounding vasculature and hemodynamics. However, the spatial orientation with respect to the gravity direction has not been taken into account although it could trigger various hemodynamic conditions. The present work addresses this possibility. It was divided in two parts: 1) the orientations of 18, 3D time-of-flight MRI (3D TOF MRI), scans of saccular aneurysms were analyzed. This investigation suggested that there was no privileged orientation for cerebral aneurysms...
December 8, 2016: Journal of Biomechanics
https://www.readbyqxmd.com/read/27621057/transcriptomic-response-of-drosophila-melanogaster-pupae-developed-in-hypergravity
#9
Shannon Hateley, Ravikumar Hosamani, Shilpa R Bhardwaj, Lior Pachter, Sharmila Bhattacharya
Altered gravity can perturb normal development and induce corresponding changes in gene expression. Understanding this relationship between the physical environment and a biological response is important for NASA's space travel goals. We use RNA-Seq and qRT-PCR techniques to profile changes in early Drosophila melanogaster pupae exposed to chronic hypergravity (3g, or three times Earth's gravity). During the pupal stage, D. melanogaster rely upon gravitational cues for proper development. Assessing gene expression changes in the pupae under altered gravity conditions helps highlight gravity-dependent genetic pathways...
October 2016: Genomics
https://www.readbyqxmd.com/read/27381480/the-biological-default-state-of-cell-proliferation-with-variation-and-motility-a-fundamental-principle-for-a-theory-of-organisms
#10
REVIEW
Ana M Soto, Giuseppe Longo, Maël Montévil, Carlos Sonnenschein
The principle of inertia is central to the modern scientific revolution. By postulating this principle Galileo at once identified a pertinent physical observable (momentum) and a conservation law (momentum conservation). He then could scientifically analyze what modifies inertial movement: gravitation and friction. Inertia, the default state in mechanics, represented a major theoretical commitment: there is no need to explain uniform rectilinear motion, rather, there is a need to explain departures from it...
October 2016: Progress in Biophysics and Molecular Biology
https://www.readbyqxmd.com/read/27269583/searching-the-literature-for-proteins-facilitates-the-identification-of-biological-processes-if-advanced-methods-of-analysis-are-linked-a-case-study-on-microgravity-caused-changes-in-cells
#11
Johann Bauer, Markus Bussen, Petra Wise, Markus Wehland, Sabine Schneider, Daniela Grimm
BACKGROUND: More than one hundred reports were published about the characterization of cells from malignant and healthy tissues, as well as of endothelial cells and stem cells exposed to microgravity conditions. METHODS: We retrieved publications about microgravity related studies on each type of cells, extracted the proteins mentioned therein and analyzed them aiming to identify biological processes affected by microgravity culture conditions. RESULTS: The analysis revealed 66 different biological processes, 19 of them were always detected when papers about the four types of cells were analyzed...
July 2016: Expert Review of Proteomics
https://www.readbyqxmd.com/read/27263416/physiological-recordings-from-the-zebrafish-lateral-line
#12
J Olt, A J Ordoobadi, W Marcotti, J G Trapani
During sensory transduction, external physical stimuli are translated into an internal biological signal. In vertebrates, hair cells are specialized mechanosensory receptors that transduce sound, gravitational forces, and head movements into electrical signals that are transmitted with remarkable precision and efficiency to afferent neurons. Hair cells have a conserved structure between species and are also found in the lateral line system of fish, including zebrafish, which serve as an ideal animal model to study sensory transmission in vivo...
2016: Methods in Cell Biology
https://www.readbyqxmd.com/read/27262847/effects-and-biological-limitations-of-gz-acceleration-on-the-autonomic-functions-related-circulation-in-rats
#13
REVIEW
Yasuhiro Nishida, Satoshi Maruyama, Ichiro Shouji, Takehito Kemuriyama, Akimasa Tashiro, Hiroyuki Ohta, Kohsue Hagisawa, Megumi Hiruma, Hidetake Yokoe
The effects of gravitational loading (G load) on humans have been studied ever since the early 20th century. After the dangers of G load in the vertical head-to-leg direction (+Gz load) became evident, many animal experiments were performed between 1920 and 1945 in an effort to identify the origins of high G-force-induced loss of consciousness (G-LOC), which led to development of the anti-G suit. The establishment of norms and training for G-LOC prevention resulted in a gradual decline in reports of animal experiments on G load, a decline that steepened with the establishment of anti-G techniques in humans, such as special breathing methods and skeletal muscle contraction, called an anti-G straining maneuver, which are voluntary physiological functions...
November 2016: Journal of Physiological Sciences: JPS
https://www.readbyqxmd.com/read/26997893/deformation-of-a-micro-torque-swimmer
#14
Takuji Ishikawa, Tomoyuki Tanaka, Yohsuke Imai, Toshihiro Omori, Daiki Matsunaga
The membrane tension of some kinds of ciliates has been suggested to regulate upward and downward swimming velocities under gravity. Despite its biological importance, deformation and membrane tension of a ciliate have not been clarified fully. In this study, we numerically investigated the deformation of a ciliate swimming freely in a fluid otherwise at rest. The cell body was modelled as a capsule with a hyperelastic membrane enclosing a Newtonian fluid. Thrust forces due to the ciliary beat were modelled as torques distributed above the cell body...
January 2016: Proceedings. Mathematical, Physical, and Engineering Sciences
https://www.readbyqxmd.com/read/26643151/beyond-the-capture-of-circulating-tumor-cells-next-generation-devices-and-materials
#15
REVIEW
Brenda J Green, Tina Saberi Safaei, Adam Mepham, Mahmoud Labib, Reza M Mohamadi, Shana O Kelley
Over the last decade, significant progress has been made towards the development of approaches that enable the capture of rare circulating tumor cells (CTCs) from the blood of cancer patients, a critical capability for noninvasive tumor profiling. These advances have leveraged new insights in materials chemistry and microfluidics and allowed the capture and enumeration of CTCs with unprecedented sensitivity. However, it has become increasingly clear that simply capturing and counting tumor cells launched into the bloodstream may not provide the information needed to advance our understanding of the biology of these rare cells, or to allow us to better exploit them in medicine...
January 22, 2016: Angewandte Chemie
https://www.readbyqxmd.com/read/26637177/transient-intervals-of-hyper-gravity-enhance-endothelial-barrier-integrity-impact-of-mechanical-and-gravitational-forces-measured-electrically
#16
Robert Szulcek, Jan van Bezu, Johannes Boonstra, Jack J W A van Loon, Geerten P van Nieuw Amerongen
BACKGROUND: Endothelial cells (EC) guard vascular functions by forming a dynamic barrier throughout the vascular system that sensitively adapts to 'classical' biomechanical forces, such as fluid shear stress and hydrostatic pressure. Alterations in gravitational forces might similarly affect EC integrity, but remain insufficiently studied. METHODS: In an unique approach, we utilized Electric Cell-substrate Impedance Sensing (ECIS) in the gravity-simulators at the European Space Agency (ESA) to study dynamic responses of human EC to simulated micro- and hyper-gravity as well as to classical forces...
2015: PloS One
https://www.readbyqxmd.com/read/26510266/platelet-transfusion-in-chemotherapy-patients-comparison-of-the-effect-of-intravenous-infusion-pumps-versus-gravity-transfusion
#17
COMPARATIVE STUDY
A Meess
Platelet concentrates are given to patients suffering with severe thrombocytopenia usually by a gravity transfusion procedure. Increasing patient numbers that are in need of this treatment increase the pressure on hospital staff and space. In order to combat time issues, the use of medical devices such as intravenous infusion pumps are thought to be beneficial for time and simultaneously for safety in transfusion practices. By using infusion pumps, platelet concentrates can be transfused in less time and provide accurate volume measurements...
2015: British Journal of Biomedical Science
https://www.readbyqxmd.com/read/26506009/muscle-bone-interactions-from-experimental-models-to-the-clinic-a-critical-update
#18
Michaël R Laurent, Vanessa Dubois, Frank Claessens, Sabine M P Verschueren, Dirk Vanderschueren, Evelien Gielen, Ferran Jardí
Bone is a biomechanical tissue shaped by forces from muscles and gravitation. Simultaneous bone and muscle decay and dysfunction (osteosarcopenia or sarco-osteoporosis) is seen in ageing, numerous clinical situations including after stroke or paralysis, in neuromuscular dystrophies, glucocorticoid excess, or in association with vitamin D, growth hormone/insulin like growth factor or sex steroid deficiency, as well as in spaceflight. Physical exercise may be beneficial in these situations, but further work is still needed to translate acceptable and effective biomechanical interventions like vibration therapy from animal models to humans...
September 5, 2016: Molecular and Cellular Endocrinology
https://www.readbyqxmd.com/read/26460038/unconstrained-muscle-tendon-workloops-indicate-resonance-tuning-as-a-mechanism-for-elastic-limb-behavior-during-terrestrial-locomotion
#19
Benjamin D Robertson, Gregory S Sawicki
In terrestrial locomotion, there is a missing link between observed spring-like limb mechanics and the physiological systems driving their emergence. Previous modeling and experimental studies of bouncing gait (e.g., walking, running, hopping) identified muscle-tendon interactions that cycle large amounts of energy in series tendon as a source of elastic limb behavior. The neural, biomechanical, and environmental origins of these tuned mechanics, however, have remained elusive. To examine the dynamic interplay between these factors, we developed an experimental platform comprised of a feedback-controlled servo-motor coupled to a biological muscle-tendon...
October 27, 2015: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/26378793/suppression-of-hydroxycinnamate-network-formation-in-cell-walls-of-rice-shoots-grown-under-microgravity-conditions-in-space
#20
Kazuyuki Wakabayashi, Kouichi Soga, Takayuki Hoson, Toshihisa Kotake, Takashi Yamazaki, Akira Higashibata, Noriaki Ishioka, Toru Shimazu, Keiji Fukui, Ikuko Osada, Haruo Kasahara, Motoshi Kamada
Network structures created by hydroxycinnamate cross-links within the cell wall architecture of gramineous plants make the cell wall resistant to the gravitational force of the earth. In this study, the effects of microgravity on the formation of cell wall-bound hydroxycinnamates were examined using etiolated rice shoots simultaneously grown under artificial 1 g and microgravity conditions in the Cell Biology Experiment Facility on the International Space Station. Measurement of the mechanical properties of cell walls showed that shoot cell walls became stiff during the growth period and that microgravity suppressed this stiffening...
2015: PloS One
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