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https://www.readbyqxmd.com/read/28223156/electrophysiological-properties-of-computational-human-ventricular-cell-action-potential-models-under-acute-ischemic-conditions
#1
REVIEW
Sara Dutta, Ana Mincholé, T Alexander Quinn, Blanca Rodriguez
Acute myocardial ischemia is one of the main causes of sudden cardiac death. The mechanisms have been investigated primarily in experimental and computational studies using different animal species, but human studies remain scarce. In this study, we assess the ability of four human ventricular action potential models (Tentusscher et al., 2006; Grandi et al., 2010; Carro et al., 2011; O'Hara et al., 2011) to simulate key electrophysiological consequences of acute myocardial ischemia in single cell and tissue simulations...
February 18, 2017: Progress in Biophysics and Molecular Biology
https://www.readbyqxmd.com/read/28219811/stress-echocardiography-in-patients-who-experienced-mechanical-ventilation-weaning-failure
#2
Manuel Ruiz-Bailén, Jesús Cobo-Molinos, Ana Castillo-Rivera, María Dolores Pola-Gallego-de-Guzmán, Antonio Cárdenas-Cruz, Antonio Martínez-Amat, María Sevilla-Martínez, Clara Hernández-Caballero
INTRODUCTION: Critically ill patients may suffer varying degrees of temporary myocardial dysfunction during respiratory weaning that could play an important role in weaning failure. OBJECTIVES: In this study, we tried to assess the existence of temporary diastolic dysfunction during respiratory weaning. METHODS: Inclusion period is from 2006 to 2015. In this study, we included 181 ventilated patients with cardiogenic shock that were being weaned from mechanical ventilation...
January 18, 2017: Journal of Critical Care
https://www.readbyqxmd.com/read/28214619/transition-from-non-fickian-to-fickian-longitudinal-transport-through-3-d-rough-fractures-scale-in-sensitivity-and-roughness-dependence
#3
Lichun Wang, M Bayani Cardenas
Understanding transport in rough fractures from non-Fickian to Fickian regimes and the prediction of non-Fickian transport is critical for the development of new transport theories and many practical applications. Through computational experiments that fall within the macrodispersion regime, we first simulated and analyzed solute transport through synthetic rough fractures with stationary geometrical properties (i.e., fracture roughness σb/〈b〉 and correlation length λ, where b refers to aperture with its standard deviation σb and arithmetic mean 〈b〉) across increasing fracture longitudinal transport domain length L, with L/λ ranging from 2...
February 4, 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28211141/potential-relocation-of-climatic-environments-suggests-high-rates-of-climate-displacement-within-the-north-american-protection-network
#4
Enric Batllori, Marc-André Parisien, Sean A Parks, Max A Moritz, Carol Miller
Ongoing climate change may undermine the effectiveness of protected area networks in preserving the set of biotic components and ecological processes they harbor, thereby jeopardizing their conservation capacity into the future. Metrics of climate change, particularly rates and spatial patterns of climatic alteration, can help assess potential threats. Here, we perform a continent-wide climate change vulnerability assessment whereby we compare the baseline climate of the protected area network in North America (Canada, USA, México - NAM) to the projected end-of-century climate (2071-2100)...
February 17, 2017: Global Change Biology
https://www.readbyqxmd.com/read/28208850/motor-nerve-conduction-velocity-in-postmenopausal-women-with-peripheral-neuropathy
#5
Akanksha Singh, Naiyer Asif, Paras Nath Singh, Mohd Mobarak Hossain
INTRODUCTION: The post-menopausal phase is characterized by a decline in the serum oestrogen and progesterone levels. This phase is also associated with higher incidence of peripheral neuropathy. AIM: To explore the relationship between the peripheral motor nerve status and serum oestrogen and progesterone levels through assessment of Motor Nerve Conduction Velocity (MNCV) in post-menopausal women with peripheral neuropathy. MATERIALS AND METHODS: This cross-sectional study was conducted at Jawaharlal Nehru Medical College during 2011-2013...
December 2016: Journal of Clinical and Diagnostic Research: JCDR
https://www.readbyqxmd.com/read/28208773/wind-tunnel-measurements-for-flutter-of-a-long-afterbody-bridge-deck
#6
Zeng-Shun Chen, Cheng Zhang, Xu Wang, Cun-Ming Ma
Bridges are an important component of transportation. Flutter is a self-excited, large amplitude vibration, which may lead to collapse of bridges. It must be understood and avoided. This paper takes the Jianghai Channel Bridge, which is a significant part of the Hong Kong-Zhuhai-Macao Bridge, as an example to investigate the flutter of the bridge deck. Firstly, aerodynamic force models for flutter of bridges were introduced. Then, wind tunnel tests of the bridge deck during the construction and the operation stages, under different wind attack angles and wind velocities, were carried out using a high frequency base balance (HFBB) system and laser displacement sensors...
February 9, 2017: Sensors
https://www.readbyqxmd.com/read/28196362/practical-application-of-linear-growth-measurements-in-clinical-research-in-low-and-middle-income-countries%C3%A2
#7
Jan M Wit, John H Himes, Stef van Buuren, Donna M Denno, Parminder S Suchdev
BACKGROUND/AIMS: Childhood stunting is a prevalent problem in low- and middle-income countries and is associated with long-term adverse neurodevelopment and health outcomes. In this review, we define indicators of growth, discuss key challenges in their analysis and application, and offer suggestions for indicator selection in clinical research contexts. METHODS: Critical review of the literature. RESULTS: Linear growth is commonly expressed as length-for-age or height-for-age z-score (HAZ) in comparison to normative growth standards...
February 14, 2017: Hormone Research in Pædiatrics
https://www.readbyqxmd.com/read/28195288/slip-divergence-of-water-flow-in-graphene-nanochannels-the-role-of-chirality
#8
Enrique Wagemann, Elton Oyarzua, Jens H Walther, Harvey A Zambrano
Graphene has attracted considerable attention due to its characteristics as a 2D material and its fascinating properties, providing a potential building block for nanofabrication. In nanochannels the solid-liquid interface plays a non-negligible role in determining the fluid dynamics. Therefore, for an optimal design of nanofluidic devices, a comprehensive understanding of the slippage in a water flow confined between graphene walls is important. In nanoconfinement, experimental and computational studies have found the slip length to increase nonlinearly when the shear rate is larger than a critical value...
February 14, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28186097/mismatch-between-marine-plankton-range-movements-and-the-velocity-of-climate-change
#9
William J Chivers, Anthony W Walne, Graeme C Hays
The response of marine plankton to climate change is of critical importance to the oceanic food web and fish stocks. We use a 60-year ocean basin-wide data set comprising >148,000 samples to reveal huge differences in range changes associated with climate change across 35 plankton taxa. While the range of dinoflagellates and copepods tended to closely track the velocity of climate change (the rate of isotherm movement), the range of the diatoms moved much more slowly. Differences in range shifts were up to 900 km in a recent warming period, with average velocities of range movement between 7 km per decade northwards for taxa exhibiting niche plasticity and 99 km per decade for taxa exhibiting niche conservatism...
February 10, 2017: Nature Communications
https://www.readbyqxmd.com/read/28182996/vital-roles-of-age-and-metabolic-syndrome-associated-risk-factors-in-sex-specific-arterial-stiffness-across-nearly-lifelong-ages-possible-implication-of-menopause-and-andropause
#10
Sung-Sheng Tsai, Yu-Sheng Lin, Jaw-Shan Hwang, Pao-Hsien Chu
BACKGROUND AND AIMS: Postmenopausal status is correlated with increased metabolic syndrome (MetS) and cardiovascular risks. However, the vital roles of age and MetS-associated risk factors in sex-specific arterial stiffness remain unclear. METHODS: In this population-based cross-sectional study of the general population, we enrolled in our Health Examination Program 9812 adult participants who were measured for brachial-ankle pulse wave velocity (baPWV) to assess arterial stiffness...
January 20, 2017: Atherosclerosis
https://www.readbyqxmd.com/read/28181589/developmental-stage-dependent-effects-of-cardiac-fibroblasts-on-function-of-stem-cell-derived-engineered-cardiac-tissues
#11
Brian Liau, Christopher P Jackman, Yanzhen Li, Nenad Bursac
We investigated whether the developmental stage of mouse cardiac fibroblasts (CFs) influences the formation and function of engineered cardiac tissues made of mouse embryonic stem cell-derived cardiomyocytes (mESC-CMs). Engineered cardiac tissue patches were fabricated by encapsulating pure mESC-CMs, mESC-CMs + adult CFs, or mESC-CMs + fetal CFs in fibrin-based hydrogel. Tissue patches containing fetal CFs exhibited higher velocity of action potential propagation and contractile force amplitude compared to patches containing adult CFs, while pure mESC-CM patches did not form functional syncytium...
February 9, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28174270/quantum-chaos-on-a-critical-fermi-surface
#12
Aavishkar A Patel, Subir Sachdev
We compute parameters characterizing many-body quantum chaos for a critical Fermi surface without quasiparticle excitations. We examine a theory of [Formula: see text] species of fermions at nonzero density coupled to a [Formula: see text] gauge field in two spatial dimensions and determine the Lyapunov rate and the butterfly velocity in an extended random-phase approximation. The thermal diffusivity is found to be universally related to these chaos parameters; i.e., the relationship is independent of [Formula: see text], the gauge-coupling constant, the Fermi velocity, the Fermi surface curvature, and high-energy details...
February 7, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28168959/the-bending-stiffness-of-shoes-is-beneficial-to-running-energetics-if-it-does-not-disturb-the-natural-mtp-joint-flexion
#13
Keonyoung Oh, Sukyung Park
A local minimum for running energetics has been reported for a specific bending stiffness, implying that shoe stiffness assists in running propulsion. However, the determinant of the metabolic optimum remains unknown. Highly stiff shoes significantly increase the moment arm of the ground reaction force (GRF) and reduce the leverage effect of joint torque at ground push-off. Inspired by previous findings, we hypothesized that the restriction of the natural metatarsophalangeal (MTP) flexion caused by stiffened shoes and the corresponding joint torque changes may reduce the benefit of shoe bending stiffness to running energetics...
January 18, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/28167523/the-role-of-cyclic-di-gmp-and-exopolysaccharide-in-type-iv-pilus-dynamics
#14
Jan Ribbe, Amy E Baker, Sebstian Euler, George A O'Toole, Berenike Maier
For Pseudomonas aeruginosa the levels of cyclic di-GMP govern the transition from the planktonic state to biofilm formation. Type IV pili (T4P) are crucial determinants of biofilm structure and dynamics, but it is unknown how the levels of c-di-GMP affect pilus dynamics. Here, we scrutinized how c-di-GMP affects molecular motor properties and adhesive behavior of T4P. By means of retraction, T4P generated forces of ∼ 30 pN. Deletion mutants in the proteins with known roles in biofilm formation, swarming motility and exopolysaccharide (EPS) production, specifically, the diguanulate cyclases sadC and roeA or the c-di-GMP phosphodiesterase bifA, showed only modest effects on velocity or force of T4P retraction...
February 6, 2017: Journal of Bacteriology
https://www.readbyqxmd.com/read/28146671/the-neuroergonomics-of-vigilance
#15
Matthew E Funke, Joel S Warm, Gerald Matthews, Gregory J Funke, Peter Y Chiu, Tyler H Shaw, Eric T Greenlee
OBJECTIVE: The aim of this study was to examine the effects of uncertainty about where in the field of view critical signals for detection appear during a vigilance task (spatial uncertainty) on cerebral blood flow velocity (CBFV) and oculomotor fatigue. BACKGROUND: Neuroergonomics is a dimension of human factors founded by Raja Parasuraman that studies brain functions underlying performance at work. Neuroergonomic studies have shown that observers in vigilance tasks lose information-processing resources over time and experience oculomotor fatigue as indexed by a temporal decline in CBFV and elevation in eye closure as reflected in the PERCLOS metric...
February 2017: Human Factors
https://www.readbyqxmd.com/read/28144872/observation-of-saltwater-intrusion-and-etm-dynamics-in-a-stably-stratified-estuary-the-yangtze-estuary-china
#16
Yuanyang Wan, Dezhao Zhao
Spatial and temporal measurement data describing spring-neap variations of velocity, salinity, and suspended sediment concentration (SSC) in the North Passage Deepwater Navigational Channel (DNC) of the Yangtze Estuary, China, were obtained in the wet season of 2012. These data were collected in the middle of the DNC and apparently document the formation of a rather stable density stratification interface and salt wedge, especially during neap tides and slack waters. The convergent zone of residual currents, salinity transport, and sediment transport during neap and spring tides oscillates in the middle and lower reach of the DNC...
February 2017: Environmental Monitoring and Assessment
https://www.readbyqxmd.com/read/28137492/subclinical-atherosclerosis-risk-markers-in-patients-with-chronic-obstructive-pulmonary-disease-a-systematic-review-and-meta-analysis
#17
REVIEW
Ling-Yun Wang, Ya-Nan Zhu, Juan-Juan Cui, Ke-Qin Yin, Shao-Xia Liu, Yong-Hua Gao
BACKGROUND AND AIMS: Chronic obstructive pulmonary disease (COPD) is associated with increased cardiovascular morbidity and mortality. Identifying early changes of cardiovascular system before the occurrence of fatal clinical event is critical for the management of COPD. We performed a meta-analysis to investigate the associations between COPD and subclinical markers of cardiovascular risk. METHODS: We searched PUBMED, EMBASE for studies published before Aug 1st, 2016, on the association between COPD and carotid intima-media thickness (CIMT), prevalence of carotid plaques, flow-mediated dilation (FMD), pulse-wave velocity (PWV) and augmentation index (AIx)...
February 2017: Respiratory Medicine
https://www.readbyqxmd.com/read/28131044/biglycan-expression-earlier-vascular-damage-and-pro-atherogenic-profile-improvement-after-smoke-cessation-in-young-people
#18
Giuseppe Mandraffino, Caterina Oriana Aragona, Michele Scuruchi, Federica Mamone, Angela D'Ascola, Angela Alibrandi, Maurizio Cinquegrani, Carmela Morace, Lilia Oreto, Carlo Saitta, Enricomaria Mormina, Scipione Carerj, Antonino Saitta, Egidio Imbalzano
BACKGROUND AND AIMS: Young cigarette smokers may already present with early signs of vascular inflammation and damage; biglycan (BGN) has been shown to play a critical role in the initiation and progression of vascular lesions, also in young smokers. We investigated whether after smoke cessation, monocyte BGN expression is reduced; moreover, we evaluated any improvement of pro-atherogenic profile and arterial stiffness (AS), and their relationship with BGN in abstinent smokers. METHODS: Two-hundred-fifty-one young people who had decided to quit smoking were enrolled; of these, 71 had completed the 12-month observation period maintaining smoking abstinence...
January 16, 2017: Atherosclerosis
https://www.readbyqxmd.com/read/28130798/a-new-and-simple-method-for-clarifying-the-severity-of-tricuspid-regurgitation
#19
Ibrahim Akin Izgi, Emrah Acar, Alev Kilicgedik, Ahmet Guler, Ender Ozgun Cakmak, Muhittin Demirel, Servet Izci, Mehmet Fatih Yilmaz, Mehmet Inanir, Cevat Kirma
BACKGROUND: No gold standard exists for grading tricuspid regurgitation (TR) severity. We developed a simple parameter, the right ventricular (RV) early inflow-outflow (RVEIO) index, using the early diastolic filling velocity and RV outflow velocity integrated over the systolic ejection period. We hypothesized that this index would help identify severe TR in clinical practice. METHODS: We obtained data from routine transthoracic echocardiograms. All records reporting moderate (n=395) or severe (n=395) TR were reanalyzed to measure vena contracta (VC) width, TR jet area, effective regurgitant orifice (EROA) derived with the proximal isovelocity surface area method, RVEIO index, and right-sided chamber volumes...
January 28, 2017: Echocardiography
https://www.readbyqxmd.com/read/28129321/noninvasive-quantification-of-blood-flow-in-epicardial-coronary-arteries-coronary-artery-bypass-grafts-and-anastomoses
#20
T Bruce Ferguson, Cheng Chen, Sunghan Kim, Kenneth Jacobs, Zhiyong Peng, Zhen Zhu, Ashesh N Buch, Jeffery C Basham
OBJECTIVE: Direct flow measurement in native epicardial coronary arteries, bypass conduits, and anastomoses is severely limited by the invasiveness and inaccuracy of existing technologies. As a result, less than 25% of patients undergoing coronary artery bypass grafting (CABG) worldwide have any intraoperative evaluation performed. A simple, accurate, and noninvasive technology to directly quantify blood flow and rheology surrounding anastomotic sites is a critical unmet need in CABG...
January 2017: Innovations: Technology and Techniques in Cardiothoracic and Vascular Surgery
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