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https://www.readbyqxmd.com/read/28730829/mechanism-of-electrocardiographic-t-wave-flattening-in-diabetes-mellitus-experimental-and-simulation-study
#1
K A Sedova, J E Azarov, N V Arteyeva, A O Ovechkin, M A Vaykshnorayte, V A Vityazev, O G Bernikova, D N Shmakov, P Kneppo
In the present study we investigated the contribution of ventricular repolarization time (RT) dispersion (the maximal difference in RT) and RT gradients (the differences in RT in apicobasal, anteroposterior and interventricular directions) to T-wave flattening in a setting of experimental diabetes mellitus. In 9 healthy and 11 diabetic (alloxan model) open-chest rabbits, we measured RT in ventricular epicardial electrograms. To specify the contributions of apicobasal, interventricular and anteroposterior RT gradients and RT dispersion to the body surface potentials we determined T-wave voltage differences between modified upper- and lower-chest precordial leads (T-wave amplitude dispersions, TWAD)...
July 18, 2017: Physiological Research
https://www.readbyqxmd.com/read/28729696/effects-of-cardiac-timing-and-peripheral-resistance-on-measurement-of-pulse-wave-velocity-for-assessment-of-arterial-stiffness
#2
Hanguang Xiao, Mark Butlin, Isabella Tan, Alberto Avolio
To investigate the effects of heart rate (HR), left ventricular ejection time (LVET) and wave reflection on arterial stiffness as assessed by pulse wave velocity (PWV), a pulse wave propagation simulation system (PWPSim) based on the transmission line model of the arterial tree was developed and was applied to investigate pulse wave propagation. HR, LVET, arterial elastic modulus and peripheral resistance were increased from 60 to 100 beats per minute (bpm), 0.1 to 0.45 seconds, 0.5 to 1.5 times and 0.5 to 1...
July 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28727738/propagation-characteristics-of-pulverized-coal-and-gas-two-phase-flow-during-an-outburst
#3
Aitao Zhou, Kai Wang, Lingpeng Fan, Bo Tao
Coal and gas outbursts are dynamic failures that can involve the ejection of thousands tons of pulverized coal, as well as considerable volumes of gas, into a limited working space within a short period. The two-phase flow of gas and pulverized coal that occurs during an outburst can lead to fatalities and destroy underground equipment. This article examines the interaction mechanism between pulverized coal and gas flow. Based on the role of gas expansion energy in the development stage of outbursts, a numerical simulation method is proposed for investigating the propagation characteristics of the two-phase flow...
2017: PloS One
https://www.readbyqxmd.com/read/28723965/the-prevalence-and-metabolic-characteristics-of-polycystic-ovary-syndrome-in-the-qatari-population
#4
Soha R Dargham, Lina Ahmed, Eric S Kilpatrick, Stephen L Atkin
OBJECTIVE: The prevalence of polycystic ovary syndrome (PCOS) in the Qatari population is unknown and hence the estimated impact on the local population cannot be determined. The purpose of this study was to estimate the prevalence and metabolic features of PCOS among Qatari women. DESIGN: Cross sectional analysis. PATIENTS: 3,017 Qatari subjects volunteered to be phenotyped and genotyped for the Qatar Biobank from which all women between the ages of 18-40 years were identified (750)...
2017: PloS One
https://www.readbyqxmd.com/read/28722037/magnetite-hollow-microspheres-with-a-broad-absorption-bandwidth-of-11-9-ghz-toward-promising-lightweight-electromagnetic-microwave-absorption
#5
Ivan Shanenkov, Alexander Sivkov, Alexander Ivashutenko, Viktor Zhuravlev, Qing Guo, Liping Li, Guangshe Li, GuoDong Wei, Wei Han
High-performance magnetite-based hollow spheres with the advantages of low density and low loading content are promising as an ideal lightweight electromagnetic (EM) wave absorption candidate. However, the effective preparation methods for these hollow spheres are still limited, and as a result, materials design and practical applications based on their size-dependent EM microwave attenuation properties are poorly accessible. In this study, high quality magnetite hollow spheres were successfully prepared by a simple, fast, one-step, and scalable plasma dynamic method with sole use of inexpensive precursors (oxygen and mild steel)...
July 19, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28721007/comparative-electrophysiological-responses-in-anisometropic-and-strabismic-amblyopic-children
#6
Luiz Cláudio Santos de Souza Lima, Adalmir Morterá Dantas, Guilherme Herzog Neto, Eduardo França Damasceno, Helena Parente Solari, Marcelo Palis Ventura
PURPOSE: To compare anisometropic hypermetropic amblyopic and strabismic amblyopic responses to pattern electroretinogram (PERG) and pattern visual evocated potential (PVEP). MATERIALS AND METHODS: Fifty-six patients - 18 hypermetropic anisometropic amblyopic children (mean age 9.70±2.5 years), 19 strabismic amblyopic children (mean age 10.30±2.6 years) and 19 normal emetropic subjects (mean age 10.10±2.2 years) - were enrolled in this study. After routine ophthalmic examination, PERG and PVEP were recorded in response to checks reversed at the rate of two reversals/second stimulating macular area...
2017: Clinical Ophthalmology
https://www.readbyqxmd.com/read/28720908/negative-reflecting-meta-mirrors
#7
Rui Yang, Dong Li, Dongxing Gao, Aofang Zhang, Bowei Hu, Pei Yang, Zhenya Lei, Jiacheng Li
Using the gradient phase discontinuities that meta-mirrors provide, we show that the incident wave can be reflected anomalously with a broad angle range of negative reflections. Such reversed behaviors promote the immediate applications for the planar meta-mirrors to steer the signals more arbitrarily and the convex meta-mirrors to focus and collimate electromagnetic fields. We practically implement these negative reflecting meta-mirrors through an arrangement of subwavelength ring patches and generate the desired phase distribution by also considering the incident angle...
July 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28717584/pulse-wave-analysis-with-diffusing-wave-spectroscopy
#8
Markus Belau, Wolfgang Scheffer, Georg Maret
Hypertension is a major risk factor for cardiovascular disease and thus at the origin of many deaths by e.g. heart attack or stroke. Hypertension is caused by many factors including an increase in arterial stiffness which leads to changes in pulse wave velocity and wave reflections. Those often result in an increased left ventricular load which may result in heart failure as well as an increased pulsatile pressure in the microcirculation l to damage to blood vessels. In order to specifically treat the different causes of hypertension it is desirable to perform a pulse wave analysis as a complement to measurements of systolic and diastolic pressure by brachial cuff sphygmomanometry...
July 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28715004/an-implantable-multimodal-sensor-for-oxygen-neurotransmitters-and-electrophysiology-during-spreading-depolarization-in-the-deep-brain
#9
Caddy N Hobbs, Justin A Johnson, Matthew D Verber, R Mark Wightman
Brain tissue injury is often accompanied by spreading depolarization (SD) events, marked by widespread cellular depolarization and cessation of neuronal firing. SD recruits viable tissue into the lesion, making it a focus for intervention. During SD, drastic fluctuations occur in ion gradients, extracellular neurotransmitter concentrations, cellular metabolism, and cerebral blood flow. Measuring SD requires a multimodal approach to capture the array of changes. However, the use of multiple sensors can inflict tissue damage...
July 17, 2017: Analyst
https://www.readbyqxmd.com/read/28710503/rac1-mediated-cardiac-damage-causes-diastolic-dysfunction-in-a-mouse-model-of-subacute-doxorubicin-induced-cardiotoxicity
#10
Jan Ohlig, Christian Henninger, Simone Zander, Marc Merx, Malte Kelm, Gerhard Fritz
The anticancer efficacy of anthracyclines is limited by congestive heart failure. Clinically established markers of early onset of cardiotoxicity following anthracycline treatment and preventive measures are missing. Although statins are reported to alleviate anthracycline-induced cardiotoxicity in vivo, the molecular mechanisms involved remain elusive. In vitro data point to Rac1 as major target of the cytoprotective statin effects. Here we investigated whether specific inhibition of Rac1 by NSC23766 is as effective as lovastatin in preventing subacute cardiotoxicity following doxorubicin treatment...
July 14, 2017: Archives of Toxicology
https://www.readbyqxmd.com/read/28710432/electro-mechanical-light-modulator-based-on-controlling-the-interaction-of-light-with-a-metasurface
#11
Pablo Cencillo-Abad, Jun-Yu Ou, Eric Plum, Nikolay I Zheludev
We demonstrate a reflective light modulator, a dynamic Salisbury screen where modulation of light is achieved by moving a thin metamaterial absorber to control its interaction with the standing wave formed by the incident wave and its reflection on a mirror. Electrostatic actuation of the plasmonic metamaterial absorber's position leads to a dynamic change of the Salisbury screen's spectral response and 50% modulation of the reflected light intensity in the near infrared part of the spectrum. The proposed approach can also be used with other metasurfaces to control the changes they impose on the polarization, intensity, phase, spectrum and directional distribution of reflected light...
July 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28708655/utility-of-brainstem-trigeminal-evoked-potentials-in-patients-with-primary-trigeminal-neuralgia-treated-by-microvascular-decompression
#12
Jin Zhu, Xin Zhang, Hua Zhao, Yin-Da Tang, Ting-Ting Ying, Shi-Ting Li
OBJECTIVE: To investigate the characteristics of brainstem trigeminal evoked potentials (BTEP) waveform in patients with and without trigeminal neuralgia (TN), and to discuss the utility of BTEP in patients with primary TN treated by microvascular decompression (MVD). METHODS: A retrospective review of 43 patients who underwent BTEP between January 2016 and June 2016, including 33 patients with TN who underwent MVD and 10 patients without TN. Brainstem trigeminal evoked potentials characteristics of TN and non-TN were summarized, in particular to compare the BTEP changes between pre- and post-MVD, and to discover the relationship between BTEP changes and surgical outcome...
July 13, 2017: Journal of Craniofacial Surgery
https://www.readbyqxmd.com/read/28699368/impact-of-blood-pressure-lesion-level-and-physical-activity-on-aortic-augmentation-index-in-persons-with-sci
#13
Caitlyn G Katzelnick, Joseph P Weir, Nancy Chiaravalotti, Glenn Wylie, Trevor Dyson-Hudson, William A Bauman, Jill M Wecht
Individuals with chronic spinal cord injury (SCI) are at a heightened risk of cardiovascular disease (CVD) due to autonomic nervous system dysfunction, physical inactivity and increased inflammatory processes. Arterial stiffness (AS) is recognized as an independent risk factor for CVD and, specifically, pulse wave analysis (PWA) has proven to be a useful tool to predict and track structural arterial changes that reflect arteriosclerosis. The augmentation index (AI) can be used to estimate AS and is derived from the amplitude and timing of the blood pressure (BP) wave reflection in a peripheral artery...
July 12, 2017: Journal of Neurotrauma
https://www.readbyqxmd.com/read/28697555/subjective-cognitive-complaints-in-cognitively-healthy-older-adults-and-their-relationship-to-cognitive-performance-and-depressive-symptoms
#14
Hana Markova, Ross Andel, Hana Stepankova, Miloslav Kopecek, Tomas Nikolai, Jakub Hort, Catherine Thomas-Antérion, Martin Vyhnalek
BACKGROUND: Subjective cognitive complaints (SCCs) may be an early marker of prodromal Alzheimer's disease. OBJECTIVES: Using a 10-item yes/no SCCs questionnaire (Le Questionnaire de Plainte Cognitive [QPC]), we evaluated the prevalence and distribution of SCCs in cognitively healthy Czech older adults and examined total score and specific QPC items in relation to depressive symptomology and cognitive performance. METHODS: A sample of 340 cognitively healthy older community-dwelling volunteers aged 60 or older from the third wave of the longitudinal project National Normative Study of Cognitive Determinants of Healthy Aging, who underwent a comprehensive neuropsychological assessment and completed the QPC and the 15-item Geriatric Depression Scale (GDS-15)...
July 4, 2017: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/28694710/modeling-ecodevelopmental-context-of-sexually-transmitted-disease-hiv-risk-and-protective-behaviors-among-african-american-adolescents
#15
Ya-Huei Li, Osaro Mgbere, Susan Abughosh, Hua Chen, Paula Cuccaro, Ekere James Essien
Risk and protective processes are integrated developmental processes that directly or indirectly affect behavioral outcomes. A better understanding of these processes is needed, in order to gauge their contribution to sexual risk behaviors. This retrospective cross-sectional study modeled the ecodevelopmental chain of relationships to examine the social contexts of African-American (AA) adolescents associated with sexually transmitted disease (STD)- and HIV-risk behaviors. We used data from 1,619 AA adolescents with an average age of 16±1...
2017: HIV/AIDS: Research and Palliative Care
https://www.readbyqxmd.com/read/28692445/normal-cerebral-vascular-pulsations-in-humans-changes-with-age-and-implications-for-microvascular-disease
#16
Mi O Kim, Yan Li, Fangfei Wei, Jiguang Wang, Michael F O'Rourke, Audrey Adji, Alberto P Avolio
BACKGROUND: Cerebral syndromes in older humans, secondary stroke in younger persons following trauma, and sickle cell anaemia in children, are linked by unexplained microvascular damage and high cerebral pressure or flow pulsations. The aim of this study was to characterize age-related pressure and flow waveforms patterns entering the brain, to explain these in terms of disturbed physiological function, and to consider clinical implications. METHOD: Blood flow velocity waves were measured in four cerebral vascular territories by transcranial Doppler of 1020 apparently normal patients (497 men, 21-78 years)...
July 7, 2017: Journal of Hypertension
https://www.readbyqxmd.com/read/28690408/wave-reflection-and-transmission-in-multiply-stented-blood-vessels
#17
T K Papathanasiou, A B Movchan, D Bigoni
Closed circulatory systems display an exquisite balance between vascular elasticity and viscous fluid effects, to induce pulse-smoothing and avoid resonance during the cardiac cycle. Stents in the arterial tree alter this balance through stiffening and because a periodic structure is introduced, capable of interacting with the fluid in a complex way. While the former feature has been investigated, the latter received no attention so far. But periodic structures are the building blocks of metamaterials, known for their 'non-natural' behaviour...
June 2017: Proceedings. Mathematical, Physical, and Engineering Sciences
https://www.readbyqxmd.com/read/28688430/imaging-of-rotational-wave-function-in-photodissociation-of-rovibrationally-excited-hcl-molecules
#18
K Grygoryeva, J Rakovský, O Votava, M Fárník
We demonstrate a visualization of quantum mechanical phenomena with the velocity map imaging (VMI) technique, combining vibrationally mediated photodissociation (VMP) of a simple diatomic HCl with the VMI of its H-photofragments. Free HCl molecules were excited by a pump infrared (IR) laser pulse to particular rotational J levels of the v = 2 vibrational state, and subsequently a probe ultraviolet laser photodissociated the molecule at a fixed wavelength of 243.07 nm where also the H-fragments were ionized...
July 7, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28687326/cellular-origin-of-intrinsic-optical-signals-in-the-rabbit-retina
#19
A Naderian, L Bussières, S Thomas, F Lesage, C Casanova
Optical imaging of retinal intrinsic signals is a relatively new method that provides spatiotemporal patterns of retinal activity through activity-dependent changes in light reflectance of the retina. The exact physiological mechanisms at the origin of retinal intrinsic signals are poorly understood and there are significant inter-species differences in their characteristics and cellular origins. In this study, we re-examined this issue through pharmacological dissection of retinal intrinsic signals in the rabbit with simultaneous ERG recordings...
July 13, 2017: Vision Research
https://www.readbyqxmd.com/read/28684327/revisiting-the-earliest-electrophysiological-correlate-of-familiar-face-recognition
#20
Wanyi Huang, Xia Wu, Liping Hu, Lei Wang, Yulong Ding, Zhe Qu
The present study used event-related potentials (ERPs) to reinvestigate the earliest face familiarity effect (FFE: ERP differences between familiar and unfamiliar faces) that genuinely reflects cognitive processes underlying recognition of familiar faces in long-term memory. To trigger relatively early FFEs, participants were required to categorize upright and inverted famous faces and unknown faces in a task that placed high demand on face recognition. More importantly, to determine whether an observed FFE was linked to on-line face recognition, systematical investigation about the relationship between the FFE and behavioral performance of face recognition was conducted...
July 4, 2017: International Journal of Psychophysiology
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