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https://www.readbyqxmd.com/read/28717176/negative-velocity-fluctuations-and-non-equilibrium-fluctuation-relation-for-a-driven-high-critical-current-vortex-state
#1
Biplab Bag, Gorky Shaw, S S Banerjee, Sayantan Majumdar, A K Sood, A K Grover
Under the influence of a constant drive the moving vortex state in 2H-NbS2 superconductor exhibits a negative differential resistance (NDR) transition from a steady flow to an immobile state. This state possesses a high depinning current threshold ([Formula: see text]) with unconventional depinning characteristics. At currents well above [Formula: see text], the moving vortex state exhibits a multimodal velocity distribution which is characteristic of vortex flow instabilities in the NDR regime. However at lower currents which are just above [Formula: see text], the velocity distribution is non-Gaussian with a tail extending to significant negative velocity values...
July 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28709260/pneumatic-fractures-in-confined-granular-media
#2
Fredrik K Eriksen, Renaud Toussaint, Antoine L Turquet, Knut J Måløy, Eirik G Flekkøy
We perform experiments where air is injected at a constant overpressure P_{in}, ranging from 5 to 250 kPa, into a dry granular medium confined within a horizontal linear Hele-Shaw cell. The setup allows us to explore compacted configurations by preventing decompaction at the outer boundary, i.e., the cell outlet has a semipermeable filter such that beads are stopped while air can pass. We study the emerging patterns and dynamic growth of channels in the granular media due to fluid flow, by analyzing images captured with a high speed camera (1000 images/s)...
June 2017: Physical Review. E
https://www.readbyqxmd.com/read/28704929/radio-frequency-based-nh%C3%A2-selective-catalytic-reduction-catalyst-control-studies-on-temperature-dependency-and-humidity-influences
#3
Markus Dietrich, Gunter Hagen, Willibald Reitmeier, Katharina Burger, Markus Hien, Philippe Grass, David Kubinski, Jaco Visser, Ralf Moos
The upcoming more stringent automotive emission legislations and current developments have promoted new technologies for more precise and reliable catalyst control. For this purpose, radio-frequency-based (RF) catalyst state determination offers the only approach for directly measuring the NH₃ loading on selective catalytic reduction (SCR) catalysts and the state of other catalysts and filter systems. Recently, the ability of this technique to directly control the urea dosing on a current NH₃ storing zeolite catalyst has been demonstrated on an engine dynamometer for the first time and this paper continues that work...
July 12, 2017: Sensors
https://www.readbyqxmd.com/read/28701849/blunt-trauma-neck-with-complete-tracheal-transection-a-diagnostic-and-therapeutic-challenge-to-the-trauma-team
#4
K N J Prakash Raju, D Anandhi, R Surendar, Ashwith Shetty, Vinay R Pandit
Survival following trachea-esophageal transection is uncommon. Establishing a secure airway has the highest priority in trauma management. Airway management is a unique and a defining element to the specialty of emergency medicine. There is no doubt regarding the significance of establishing a patent airway in the critically ill patient in the emergency department. Cannot intubate and cannot ventilate situation is a nightmare to all emergency physicians. The most important take-home message from this case report is that every Emergency physician should have the ability to predict "difficult airway" and recognize "failed airway" very early and be skilled in performing rescue techniques when routine oral-tracheal intubation fails...
June 2017: Indian Journal of Critical Care Medicine
https://www.readbyqxmd.com/read/28694107/effects-of-non-physiological-blood-pressure-artefacts-on-cerebral-autoregulation
#5
Adam Mahdi, Erica M Rutter, Stephen J Payne
Cerebral autoregulation refers to the brain's regulation mechanisms that aim to maintain the cerebral blood flow approximately constant. It is often assessed by the autoregulation index (ARI). ARI uses arterial blood pressure and cerebral blood flow velocity time series to produce a ten-scale index of autoregulation performance (0 denoting the absence of and 9 the strongest autoregulation). Unfortunately, data are rarely free from various artefacts. Here, we consider four of the most common non-physiological blood pressure artefacts (saturation, square wave, reduced pulse pressure and impulse) and study their effects on ARI for a range of different artefact sizes...
July 7, 2017: Medical Engineering & Physics
https://www.readbyqxmd.com/read/28692658/temporal-specificity-of-the-initial-adaptive-response-in-motor-adaptation
#6
Wilsaan M Joiner, Gary C Sing, Maurice A Smith
Repeated exposure to a novel physical environment eventually leads to a mature adaptive response whereby feedforward changes in motor output mirror both the amplitude and temporal structure of the environmental perturbations. However, adaptive responses at the earliest stages of learning have been found to be not only smaller, but systematically less specific in their temporal structure compared to later stages of learning. This observation has spawned a lively debate as to whether the temporal structure of the initial adaptive response is, in fact, stereotyped and non-specific...
July 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28691108/jetting-of-a-shear-banding-fluid-in-rectangular-ducts
#7
Paul F Salipante, Charles A E Little, Steven D Hudson
Non-Newtonian fluids are susceptible to flow instabilities such as shear banding, in which the fluid may exhibit a markedly discontinuous viscosity at a critical stress. Here we report the characteristics and causes of a jetting flow instability of shear banding wormlike micelle solutions in microfluidic channels with rectangular cross sections over an intermediate volumetric flow regime. Particle-tracking methods are used to measure the three-dimensional flow field in channels of differing aspect ratios, sizes, and wall materials...
March 2017: Physical Review Fluids
https://www.readbyqxmd.com/read/28688392/pair-correlated-stereodynamics-for-diatom-diatom-rotational-energy-transfer-no-a-2-%C3%AE-n2
#8
Thomas F M Luxford, Thomas R Sharples, Kenneth G McKendrick, Matthew L Costen
We have performed a crossed molecular beam velocity-map ion imaging study of state-to-state rotational energy transfer of NO(A(2)Σ(+), v = 0, N = 0, j = 0.5) in collisions with N2 and have measured rotational angular momentum polarization dependent images of product NO(A) rotational levels N' = 3 and 5-11 for collisions at an average energy of 797 cm(-1). We present an extension of our previously published [T. F. M. Luxford et al., J. Chem. Phys. 145, 174 304 (2016)] image analysis which includes the effect of rotational excitation of the unobserved collision partner and critically evaluate this methodology...
July 7, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28687561/impact-of-vascular-hemodynamics-on-aortic-stenosis-evaluation-new-insights-into-the-pathophysiology-of-normal-flow-small-aortic-valve-area-low-gradient-pattern
#9
Nancy Côté, Louis Simard, Anne-Sophie Zenses, Lionel Tastet, Mylène Shen, Marine Clisson, Marie-Annick Clavel
BACKGROUND: About 50% of normal-flow/low-gradient patients (ie, low mean gradient [MG] or peak aortic jet velocity and small aortic valve area) have severe aortic valve calcification as measured by computed tomography. However, they are considered to have moderate aortic stenosis (AS) in current American College of Cardiology/American Heart Association guidelines. The objective was thus to evaluate the effect of hypertension and reduced arterial compliance (rAC) on MG and Vpeak measurements...
July 7, 2017: Journal of the American Heart Association
https://www.readbyqxmd.com/read/28687005/p-but-not-e-or-l-selectin-mediated-rolling-adhesion-persistence-in-hemodynamic-flow-diverges-between-metastatic-and-leukocytic-cells
#10
Erin Elizabeth Edwards, Jaeho Oh, Ananyaveena Anilkumar, Katherine Gayle Birmingham, Susan Napier Thomas
The ability of leukocytic cells to engage selectins via rolling adhesion is critical to inflammation, but selectins are also implicated in mediating metastatic dissemination. Using a microfluidic- and flow-based cell adhesion chromatography experimental and analytical technique, we interrogated the cell-subtype differences in engagement and sustainment of rolling adhesion on P-, E-, and L-selectin-functionalized surfaces in physiological flow. Our results indicate that, particularly at low concentrations of P-selectin, metastatic but not leukocytic cells exhibit reduced rolling adhesion persistence, whereas both cell subtypes exhibited reduced persistence on L-selectin and high persistence on E-selectin, differences not revealed by flow cytometry analysis or reflected in the extent or velocity of rolling adhesion...
June 28, 2017: Oncotarget
https://www.readbyqxmd.com/read/28686440/temperature-effect-on-rheological-behavior-of-silicone-oils-a-model-for-the-viscous-heating
#11
Mario R Romano, Francesca Cuomo, Nicola Massarotti, Alessandro Mauro, Mohamed Salahudeen, Ciro Costagliola, Luigi Ambrosone
Rheological behavior of silicone oils,(CH3)3SiO-[Si(CH3)2O]n-Si(CH3)3, and their mixtures is studied. Shear stress measurements, in the temperature range 293-313 K, reveal that this family of polymers are shear thinning liquids with a yield stress below which no flow occurs. Experimental diagrams, i.e. shear stress versus shear rate, are satisfactorily described by the fluid model of Casson over a wide range of shear rates. In order to monitor the effect of temperature on fluid properties, Casson's rheological model is reformulated using the fictitious shear rate, γ ̇f, and the infinite- shear viscosity, η∞, as constitutive parameters...
July 7, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28682363/modeling-of-movement-of-liquid-metal-droplets-driven-by-an-electric-field
#12
M F Wang, M J Jin, X J Jin, S G Zuo
The motion of liquid metal has potential applications ranging from micro-pumps and self-fueled motors to rapid cooling and drug delivery. In this study, we systematically investigate the effects of the radius of LMDs (liquid metal droplets), the concentration of electrolyte solution and the applied electric field on the movement behavior of LMDs experimentally. The research also explains the experimental phenomenon with an innovative modeling analysis, which combines pertinent forces (i.e., the driving force induced by the gradient of surface tension, the viscous friction between the droplet and its surrounding electrolyte, and the friction between the droplet and the substrate)...
July 6, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28681121/indexes-of-cerebral-autoregulation-do-not-reflect-impairment-in-syncope-insights-from-head-up-tilt-test-of-vasovagal-and-autonomic-failure-subjects
#13
Pedro Castro, João Freitas, Rosa Santos, Ronney Panerai, Elsa Azevedo
PURPOSE: The study of dynamic cerebral autoregulation (CA), which adapts cerebral blood flow to arterial blood pressure (ABP) fluctuations, has been limited in orthostatic intolerance syndromes, mainly due to its stationary prerequisites hardly to meet during maneuvers to provoke syncope itself. New techniques of continuous estimates of CA could overcome this pitfall. We aimed to evaluate CA during head-up tilt test in common conditions causing syncope. METHODS: We compared three groups: eight controls; eight patients with autonomic failure due to familial amyloidotic polyneuropathy; eight patients with vasovagal syncope (VVS)...
July 5, 2017: European Journal of Applied Physiology
https://www.readbyqxmd.com/read/28680964/eye-tracking-of-occluded-self-moved-targets-role-of-haptic-feedback-and-hand-target-dynamics
#14
Frederic Danion, James Mathew, J Randall Flanagan
Previous studies on smooth pursuit eye movements have shown that humans can continue to track the position of their hand, or a target controlled by the hand, after it is occluded, thereby demonstrating that arm motor commands contribute to the prediction of target motion driving pursuit eye movements. Here, we investigated this predictive mechanism by manipulating both the complexity of the hand-target mapping and the provision of haptic feedback. Two hand-target mappings were used, either a rigid (simple) one in which hand and target motion matched perfectly or a nonrigid (complex) one in which the target behaved as a mass attached to the hand by means of a spring...
May 2017: ENeuro
https://www.readbyqxmd.com/read/28680797/a-modified-squeeze-equation-for-predicting-the-filling-ratio-of-nanoimprint-lithography
#15
JiHyeong Ryu, Ho Lee, Sang-Ho Lee, HyungJun Lim, JaeJong Lee
A numerical method using the modified squeeze model is proposed in this paper in order to overcome the limitation of the established squeeze equation and obtain filling ratios for nanoimprint lithography (NIL). Because the imprinting velocity is overestimated when the ratio of indenter width to polymer thickness is close to unity, the modified equation is critical. For verification, the numerical results are compared with the experimental data according to the various stamp geometries and pressure variation rates, for which a maximum difference of 10% is indicated...
2017: Nano Convergence
https://www.readbyqxmd.com/read/28676767/when-is-a-sprint-a-sprint-a-review-of-the-analysis-of-team-sport-athlete-activity-profile
#16
REVIEW
Alice J Sweeting, Stuart J Cormack, Stuart Morgan, Robert J Aughey
The external load of a team-sport athlete can be measured by tracking technologies, including global positioning systems (GPS), local positioning systems (LPS), and vision-based systems. These technologies allow for the calculation of displacement, velocity and acceleration during a match or training session. The accurate quantification of these variables is critical so that meaningful changes in team-sport athlete external load can be detected. High-velocity running, including sprinting, may be important for specific team-sport match activities, including evading an opponent or creating a shot on goal...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28667400/microfluidic-device-flow-field-characterization-around-tumor-spheroids-with-tunable-necrosis-produced-in-an-optimized-off-chip-process
#17
James Baye, Casey Galvin, Amy Q Shen
Tumor spheroids are a 3-D tumor model that holds promise for testing cancer therapies in vitro using microfluidic devices. Tailoring the properties of a tumor spheroid is critical for evaluating therapies over a broad range of possible indications. Using human colon cancer cells (HCT-116), we demonstrate controlled tumor spheroid growth rates by varying the number of cells initially seeded into microwell chambers. The presence of a necrotic core in the spheroids could be controlled by changing the glucose concentration of the incubation medium...
September 2017: Biomedical Microdevices
https://www.readbyqxmd.com/read/28662030/chemosensory-and-hyperoxia-circuits-in-c-elegans-males-influence-sperm-navigational-capacity
#18
Hieu D Hoang, Michael A Miller
The sperm's crucial function is to locate and fuse with a mature oocyte. Under laboratory conditions, Caenorhabditis elegans sperm are very efficient at navigating the hermaphrodite reproductive tract and locating oocytes. Here, we identify chemosensory and oxygen-sensing circuits that affect the sperm's navigational capacity. Multiple Serpentine Receptor B (SRB) chemosensory receptors regulate Gα pathways in gustatory sensory neurons that extend cilia through the male nose. SRB signaling is necessary and sufficient in these sensory neurons to influence sperm motility parameters...
June 2017: PLoS Biology
https://www.readbyqxmd.com/read/28659550/significant-prognostic-value-of-acute-preload-stress-echocardiography-using-leg-positive-pressure-maneuver-for-patients-with-symptomatic-severe-aortic-stenosis-awaiting-aortic-valve-intervention
#19
Hiroki Matsuzoe, Kensuke Matsumoto, Hidekazu Tanaka, Yutaka Hatani, Keiko Hatazawa, Hiroyuki Shimoura, Junichi Ooka, Hiroyuki Sano, Keiko Ryo-Koriyama, Toshiro Shinke, Hirotsugu Yamada, Yutaka Okita, Ken-Ichi Hirata
BACKGROUND: Although aortic valve intervention is recommended for virtually all symptomatic patients with aortic stenosis (AS), how urgently the intervention should be performed remains controversial. The aim of this study was thus to determine whether the preload reserve in response to leg-positive pressure (LPP) maneuver could serve for decision-making for AS patients awaiting aortic valve intervention.Methods and Results:Sixty-eight patients with symptomatic AS, who were referred for aortic valve intervention, were recruited...
June 28, 2017: Circulation Journal: Official Journal of the Japanese Circulation Society
https://www.readbyqxmd.com/read/28658072/the-nfl-combine-40-yard-dash-how-important-is-maximum-velocity
#20
Kenneth P Clark, Randall H Rieger, Richard F Bruno, David J Stearne
This investigation analyzed the sprint velocity profiles for athletes who completed the 40-yard (36.6m) dash at the 2016 NFL Combine. The purpose was to evaluate the relationship between maximum velocity and sprint performance, and to compare acceleration patterns for fast and slow athletes. Using freely available online sources, data were collected for body mass and sprint performance (36.6m time with split intervals at 9.1 and 18.3m). For each athlete, split times were utilized to generate modeled curves of distance vs...
June 22, 2017: Journal of Strength and Conditioning Research
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