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Pulse transit time

Vassiliki Kolovetsiou-Kreiner, Manfred Georg Moertl, Ilona Papousek, Karin Schmid-Zalaudek, Uwe Lang, Dietmar Schlembach, Mila Cervar-Zivkovic, Helmut Karl Lackner
OBJECTIVE: To explore noninvasively the complex interactions of the maternal hemodynamic system throughout pregnancy and the resulting after-effect six weeks postpartum. METHODS: Eighteen women were tested beginning at the 12th week of gestation at six time-points throughout pregnancy and six weeks postpartum. Heart rate, heart rate variability, blood pressure, pulse transit time (PTT), respiration, and baroreceptor sensitivity were analyzed in resting conditions...
2018: PloS One
Wafik Said Bahnasy, Yasser Abo Elfotoh El-Heneedy, Ahmed Mohamed El-Shamy, Marwa Yassin Badr, Reham Ahmed Amer, Ibrahim Salah Eldeen Ibrahim
Background: The sensori-motor manifestations of Guillain Barré Syndrome (GBS) are usually severe enough to mask the psychiatric and sleep problems which are in need for more attention for better functional outcome. Methods: This study was performed on 20 GBS patients and 10 healthy controls. Patients were evaluated initially before immunotherapy using the Overall Disability Sum Score (ODSS), Neuropathy Pain Scale (NPS), Hamilton Anxiety Scale (HAS), Montgomery-Åsberg Depression Rating Scale (MADRS) and one-night polysomnography (PSG) followed by the multiple sleep latency test (MSLT) to evaluate the mean sleep latencies...
2018: Egypt J Neurol Psychiatr Neurosurg
Miguel Ochmann, Abid Hussain, Inga von Ahnen, Amy A Cordones, Kiryong Hong, Jae Hyuk Lee, Rory Ma, Katrin Adamczyk, Tae Kyu Kim, Robert W Schoenlein, Oriol Vendrell, Nils Huse
We have investigated dimethyl disulfide as the basic moiety for understanding the photochemistry of disulfide bonds, which are central to a broad range of biochemical processes. Picosecond time-resolved X-ray absorption spectroscopy at the sulfur K-edge provides unique element-specific insight into the photochemistry of the disulfide bond initiated by 267 nm femtosecond pulses. We observe a broad but distinct transient induced absorption spectrum which recovers on at least two time scales in the nanosecond range...
May 17, 2018: Journal of the American Chemical Society
Xiaoling Zhang, Xin Ren, Fang Zhang
Black phosphorus quantum dots (BPQDs) with an average diameter of ≈ 6 nm and a height of ≈1.1 nm are successfully synthesized by using a pulsed laser ablation (PLA) method in isopropyl ether (IPE) solvent. PL quantum yield of the as-prepared sample is as high as 20.7% which is 3 times that of the BPQDs prepared by probe ultrasonic exfoliation (approximately 7.2%) for the first time. The stable and blue-violet photoluminescence (PL) emission of the BPQDs is observed, which is elucidated that electrons transit from the LUMO energy level to the HOMO energy level as well as energy levels below the HOMO ( H1 and H2 )...
May 16, 2018: Chemistry, An Asian Journal
Markus Boland, Rüdiger Stirnberg, Eberhard D Pracht, Johanna Kramme, Roberto Viviani, Julia Stingl, Tony Stöcker
PURPOSE: To investigate the impact of accelerated, single-shot 3D-GRASE acquisition on quantitative arterial spin labeling (ASL) with multiple and single post-labeling delay (PLD) in terms of perfusion-weighted SNR per unit scan time (TSNRPW ) and quantification accuracy. METHODS: Five subjects were scanned on a 3T MRI scanner using the pseudo-continuous arterial spin labeling (PCASL) technique with a 3D-GRASE imaging sequence capable of parallel imaging acceleration...
May 16, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Bahman Kheradmand-Boroujeni, Markus P Klinger, Axel Fischer, Hans Kleemann, Karl Leo, Frank Ellinger
Organic/polymer transistors can enable the fabrication of large-area flexible circuits. However, these devices are inherently temperature sensitive due to the strong temperature dependence of charge carrier mobility, suffer from low thermal conductivity of plastic substrates, and are slow due to the low mobility and long channel length (L). Here we report a new, advanced characterization circuit that within around ten microseconds simultaneously applies an accurate large-signal pulse bias and a small-signal sinusoidal excitation to the transistor and measures many high-frequency parameters...
May 16, 2018: Scientific Reports
Kenneth R Beyerlein, H Olof Jönsson, Roberto Alonso-Mori, Andrew Aquila, Saša Bajt, Anton Barty, Richard Bean, Jason E Koglin, Marc Messerschmidt, Davide Ragazzon, Dimosthenis Sokaras, Garth J Williams, Stefan Hau-Riege, Sébastien Boutet, Henry N Chapman, Nicuşor Tîmneanu, Carl Caleman
The bright ultrafast pulses of X-ray Free-Electron Lasers allow investigation into the structure of matter under extreme conditions. We have used single pulses to ionize and probe water as it undergoes a phase transition from liquid to plasma. We report changes in the structure of liquid water on a femtosecond time scale when irradiated by single 6.86 keV X-ray pulses of more than 106 J/cm2 These observations are supported by simulations based on molecular dynamics and plasma dynamics of a water system that is rapidly ionized and driven out of equilibrium...
May 14, 2018: Proceedings of the National Academy of Sciences of the United States of America
Xia Tan, Zhong Ji, Yadan Zhang
BACKGROUND: Non-invasive continuous blood pressure monitoring can provide an important reference and guidance for doctors wishing to analyze the physiological and pathological status of patients and to prevent and diagnose cardiovascular diseases in the clinical setting. Therefore, it is very important to explore a more accurate method of non-invasive continuous blood pressure measurement. OBJEVTIVE: To address the shortcomings of existing blood pressure measurement models based on pulse wave transit time or pulse wave parameters, a new method of non-invasive continuous blood pressure measurement - the GA-MIV-BP neural network model - is presented...
April 25, 2018: Technology and Health Care: Official Journal of the European Society for Engineering and Medicine
Zengding Liu, Ji Chen, Minfang Tang
Aiming at the defects that the traditional pulse transit time (PTT) detection methods are sensitive to changes in photoplethysmography (PPG) signal and require heavy computation, we proposed a new algorithm to detect PTT based on waveform time domain feature and dynamic difference threshold. We calculated the PTT by using dynamic difference threshold method to detect the R-waves of electrocardiogram (ECG), shortening the main peak detection range in PPG signal according to the characteristics of the waveform time domain, and using R wave to detect the main peak of PPG signal...
June 1, 2017: Sheng Wu Yi Xue Gong Cheng Xue za Zhi, Journal of Biomedical Engineering, Shengwu Yixue Gongchengxue Zazhi
Slobodan Mihaljevic, Milenko Bevanda, Kresimir Reiner, Krunoslav Sporcic, Ljiljana Mihaljevic, Marko Cacic
Objective: To detect changes in finger photoplethysmography after administration of epidural anaesthesia as a surrogate method for evaluating autonomic nervous system activity. Methods: We included a total of 46 patients scheduled for elective surgical procedures under lumbar epidural anaesthesia. A Biopac SS4LA pulse plethysmograph transducer was used for photoplethysmography recording, and the device was placed on the first toe of the right leg. The first standard lead of the electrocardiogram was simultaneously measured with the finger photoplethysmography...
April 2018: Turkish Journal of Anaesthesiology and Reanimation
Richard A Gill, Rory C O'Connor, Aaron Rhodes, Tara B B Bishop, Daniel C Laughlin, Samuel B St Clair
Resource availability and biotic interactions control opportunities for the establishment and expansion of invasive species. Studies on biotic resistance to plant invasions have typically focused on competition and occasionally on herbivory, while resource-oriented studies have focused on water or nutrient pulses. Through synthesizing these approaches, we identify conditions that create invasion opportunities. In a nested fully factorial experiment, we examined how chronic alterations in water availability and rodent density influenced the density of invasive species in both the Mojave Desert and the Great Basin Desert after fire...
May 7, 2018: Oecologia
C Chad Quarles, Laura C Bell, Ashley M Stokes
In the context of neurologic disorders, dynamic susceptibility contrast (DSC) and dynamic contrast enhanced (DCE) MRI provide valuable insights into cerebral vascular function, integrity, and architecture. Even after two decades of use, these modalities continue to evolve as their biophysical and kinetic basis is better understood, with improvements in pulse sequences and accelerated imaging techniques and through application of more robust and automated data analysis strategies. Here, we systematically review each of these elements, with a focus on how their integration improves kinetic parameter accuracy and the development of new hemodynamic biomarkers that provide sub-voxel sensitivity (e...
May 2, 2018: NeuroImage
Akiko Nishiyama, Yoshiaki Nakajima, Ken'ichi Nakagawa, Kaoru Minoshima
We demonstrated Doppler-free two-photon absorption dual-comb spectroscopy of 5S1/2 - 5D5/2 and 5D3/2 transitions of Rb. We employed simple pulse-shaping of the dual-comb source and eliminated Doppler-broadening backgrounds, which cause fitting errors of the Doppler-free signals. Moreover, to improve sensitivity, we investigated the coherence in dual-comb fluorescence signals and the coherent averaging method was applied to fluorescence dual-comb detection for the first time. The detection sensitivity was significantly improved by coherent averaging to reduce the noise floor...
April 2, 2018: Optics Express
Xinge Jiang, Shoushui Wei, Dingchang Zheng, Peng Huang, Chengyu Liu
BACKGROUND: Changes of pulse transit time (PTT) induced by arm position were studied for unilateral arm. However, consistency of the PTT changes was not validated for both arm sides. OBJECTIVE: We aimed to quantify the PTT changes between horizontal and non-horizontal positions from right arm and left arm in order to explore the consistency of both arms. METHODS: Twenty-four normal subjects aged between 21 and 50 (14 male and 10 female) years were enrolled...
April 20, 2018: Technology and Health Care: Official Journal of the European Society for Engineering and Medicine
Hai-Xia Yuan, Wen-Ping Wang, Jie-Xian Wen, Le-Wu Lin, Agata A Exner, Pei-Shan Guan, Xue-Jun Chen
Aggressive tumors are characterized by angiogenesis that promotes the migration and dissemination of tumor cells. Our aim was to develop a dual-targeted microbubble system for non-invasive evaluation of tumor angiogenesis in ultrasound. Avidinylated microbubbles were conjugated with biotinylated arginylglycylaspartic acid and vascular endothelial growth factor receptor 2 (VEGFR2) antibodies. Subcutaneous MHCC-97H liver carcinoma models were established. Non-targeted, αvβ3-targeted, VEGFR2-targeted and dual-targeted microbubbles was intravenously injected in series while acquiring ultrasound images of the tumor...
April 26, 2018: Ultrasound in Medicine & Biology
Yun Yeon Park, Ju-Hyun Ahn, Min-Guk Cho, Jae-Ho Lee
ATP depletion inhibits cell cycle progression, especially during the G1 phase and the G2 to M transition. However, the effect of ATP depletion on mitotic progression remains unclear. We observed that the reduction of ATP after prometaphase by simultaneous treatment with 2-deoxyglucose and NaN3 did not arrest mitotic progression. Interestingly, ATP depletion during nocodazole-induced prometaphase arrest resulted in mitotic slippage, as indicated by a reduction in mitotic cells, APC/C-dependent degradation of cyclin B1, increased cell attachment, and increased nuclear membrane reassembly...
April 27, 2018: Experimental & Molecular Medicine
Uğur Çetiner, Andriy Anishkin, Sergei Sukharev
Adaptive desensitization and inactivation are common properties of most ion channels and receptors. The mechanosensitive channel of small conductance MscS, which serves as a low-threshold osmolyte release valve in most bacteria, inactivates not from the open, but from the resting state under moderate tensions. This mechanism enables the channel to respond differently to slow tension ramps versus abruptly applied stimuli. In this work, we present a reconstruction of the energy landscape for MscS transitions based on patch current kinetics recorded under special pressure protocols...
April 23, 2018: European Biophysics Journal: EBJ
Manoj Kumar Dasa, Christos Markos, Michael Maria, Christian R Petersen, Peter M Moselund, Ole Bang
We propose a cost-effective high-pulse energy supercontinuum (SC) source based on a telecom range diode laser-based amplifier and a few meters of standard single-mode optical fiber, with a pulse energy density as high as ~25 nJ/nm in the 1650-1850 nm regime (factor >3 times higher than any SC source ever used in this wavelength range). We demonstrate how such an SC source combined with a tunable filter allows high-resolution spectroscopic photoacoustic imaging and the spectroscopy of lipids in the first overtone transition band of C-H bonds (1650-1850 nm)...
April 1, 2018: Biomedical Optics Express
Chelsea Marie Taliaferro, Evgeny O Danilov, Felix N Castellano
For decades, transition metal hydrides have been at the forefront of numerous photocatalytic reactions leveraging either photoacid or photohydride generation. Of upmost importance is the nature of the M-H bond itself, which is typically the major site of photochemical reactivity, particularly in Ir(III) hydrides featuring metal-to-ligand charge transfer (MLCT) excited states. As a departure point for understanding the fundamental spectroscopy and photophysics of the MLCT excited states of Ir(III) diimine hydrides, cis-[Ir(bpy)2H2]+ (bpy = 2,2'-bipyridine) and its deuterated analog cis-[Ir(bpy)2D2]+ were prepared and investigated...
April 19, 2018: Journal of Physical Chemistry. A
Ivan Madan, Jože Buh, Vladimir V Baranov, Viktor V Kabanov, Aleš Mrzel, Dragan Mihailovic
Optical control of states exhibiting macroscopic phase coherence in condensed matter systems opens intriguing possibilities for materials and device engineering, including optically controlled qubits and photoinduced superconductivity. Metastable states, which in bulk materials are often associated with the formation of topological defects, are of more practical interest. Scaling to nanosize leads to reduced dimensionality, fundamentally changing the system's properties. In one-dimensional superconducting nanowires, vortices that are present in three-dimensional systems are replaced by fluctuating topological defects of the phase...
March 2018: Science Advances
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