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Pulse transit time

Tatiana I Baranova, Dmitrii N Berlov, Oleg S Glotov, Ekaterina A Korf, Alexey D Minigalin, Alla V Mitrofanova, Ildus I Ahmetov, Andrey S Glotov
The purpose of this study was to investigate the genetic mechanisms of the defense vascular reactions in response to the diving reflex in humans with polymorphisms in the genes ADBR2, ACE, AGTR1, BDKRB2, and REN. We hypothesized that protective vascular reactions, in response to the diving reflex, are genetically determined and are distinguished in humans with gene polymorphisms of the renin-angiotensin and kinin-bradykinin system. A total of 80 subjects (19±1.4 years) participated in the study. The intensity of the vascular response was estimated using photopletismogram...
December 6, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Ye-Hong Chen, Qi-Cheng Wu, Bi-Hua Huang, Jie Song, Yan Xia
A scheme for arbitrary quantum state engineering (QSE) in three-state systems is proposed. Firstly, starting from a set of complete orthogonal time-dependent basis with undetermined coefficients, a time-dependent Hamiltonian is derived via Counterdiabatic driving for the purpose of guiding the system to attain an arbitrary target state at a predefined time. Then, on request of the assumed target states, two single-mode driving protocols and a multi-mode driving protocol are proposed as examples to discuss the validity of the QSE scheme...
December 5, 2016: Scientific Reports
C Mao, X Wang, X Zou, J Lehr
This paper presents the experimental results of a monolithic radial transmission line (MRTL) that may be used in pulsed power generators and microwave devices. The MRTL with a hyperbolic impedance profile is 508 mm in radius, corresponding to a one-way transit time of 15 ns for the electromagnetic wave. In the experiments, up to twenty identical voltage pulses, 10 ns in FWHM and 2 ns in rise-time, were fed into the MRTL through 20 input BNC connectors that are uniformly distributed along the outer circumference of the MRTL...
November 2016: Review of Scientific Instruments
Yurie Obata, Maki Mizogami, Sarabdeep Singh, Daniel Nyhan, Dan E Berkowitz, Jochen Steppan, Viachaslau Barodka
The effect of blood pressure on pulse wave velocity (PWV) is well established. However, PWV variability with acute hemodynamic changes has not been examined in the clinical setting. The aim of the present study is to investigate the effect of hemodynamic changes on PWV in patients who undergo cardiothoracic surgery. Using data from 25 patients, we determined blood pressure (BP), heart rate (HR), and the left ventricular outflow tract (LVOT) velocity-time integral. By superimposing the radial arterial waveform on the continuous wave Doppler waveform of the LVOT, obtained by transesophageal echo, we were able to determine pulse transit time and to calculate PWV, stroke volume (SV), cardiac output (CO), and systemic vascular resistance (SVR)...
2016: BioMed Research International
Jing Liu, Bryan Ping-Yen Yan, Wen-Xuan Dai, Xiao-Rong Ding, Yuan-Ting Zhang, Ni Zhao
In this work, we present a multi-wavelength (MW) PPG method exploiting the wavelength dependence of light penetration in skin tissue to provide depth resolution of skin blood pulsation. The MW PPG system requires two to three light sources in different wavelengths and extracts the arterial blood pulsation through a multi-wavelength multi-layer light-skin interaction model, which removes the capillary pulsation (determined from the short-wavelength PPG signal) from the long-wavelength PPG signal using absorption weighting factors that are quasi-analytically calibrated...
October 1, 2016: Biomedical Optics Express
Dillon K Walker, John J Thaden, Agata Wierzchowska-McNew, Marielle P K J Engelen, Nicolaas E P Deutz
Our objective was to develop a quick and simplified method for the determination of β-Hydroxy-β-methylbutyrate (HMB) and ɑ-ketoisocaproic acid (KIC) concentrations and enrichments by GC/MS/MS to determine the turnover rate of HMB in humans. In experiment 1, we provided a pulse of L-[5,5,5-(2)H3]leucine to younger adults in the postabsorptive state then collected blood samples over a 4h time period. In experiment 2, we provided a pulse of [3,4,methyl-(13)C3]HMB to older adults in the postabsorptive state then collected blood samples over a 3h time period...
November 9, 2016: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Chuan-Sen Yang, Da-Shan Shang, Yi-Sheng Chai, Li-Qin Yan, Bao-Gen Shen, Young Sun
Solid state electrochemical cells with synaptic functions have important applications in building smart-terminal networks. Here, the essential synaptic functions including potentiation and depression of synaptic weight, transition from short- to long-term plasticity, spike-rate-dependent plasticity, and spike-timing-dependent plasticity behavior were successfully realized in an Ag/MoOx/fluorine-doped tin oxide (FTO) cell with continual resistance switching. The synaptic plasticity underlying these functions was controlled by tuning the excitatory post-synaptic current (EPSC) decay, which is determined by the applied voltage pulse number, width, frequency, and intervals between the pre- and post-spikes...
November 17, 2016: Physical Chemistry Chemical Physics: PCCP
K Veyrinas, V Gruson, S J Weber, L Barreau, T Ruchon, J-F Hergott, J-C Houver, R R Lucchese, P Salières, D Dowek
Due to the intimate anisotropic interaction between an XUV light field and a molecule resulting in photoionization (PI), molecular frame photoelectron angular distributions (MFPADs) are most sensitive probes of both electronic/nuclear dynamics and the polarization state of the ionizing light field. Consequently, they encode the complex dipole matrix elements describing the dynamics of the PI transition, as well as the three normalized Stokes parameters s1, s2, s3 characterizing the complete polarization state of the light, operating as molecular polarimetry...
November 17, 2016: Faraday Discussions
Jonathan R Weir-McCall, Anu Kamalasanan, Deidre B Cassidy, Allan D Struthers, Brian J Lipworth, J Graeme Houston
INTRODUCTION: To compare the reproducibility of pulmonary pulse wave velocity (PWV) techniques, and the effects of age and exercise on these. METHODS: 10 young healthy volunteers (YHV) and 20 older healthy volunteers (OHV) with no cardiac or lung condition were recruited. High temporal resolution phase contrast sequences were performed through the main pulmonary arteries (MPAs), right pulmonary arteries (RPAs) and left pulmonary arteries (LPAs), while high spatial resolution sequences were obtained through the MPA...
2016: BMJ Open Respiratory Research
Eva-Maria Stübling, Stefan Busch, Jan C Balzer, Martin Koch
We present a compact sensor head for a multi-channel terahertz (THz) spectroscopy system. A THz pulse generated by a photoconductive antenna is split into spatially separated sub-pulses, which have different transit times. The time-dependent order of the sub-pulses can be translated into a spatial resolution. By using only one pair of antennas the developed sensor head provides up to 20 individual measurement zones with full amplitude and phase information. The sensor head can be integrated into two boxes with a small footprint so that the system is well suited for industrial applications...
October 3, 2016: Optics Express
Roy B Anunciado, Seth Ashman, Lutz Hüwel
Lifetimes of partially resolved ro-vibrational levels of the Na2 2(1)Σu(+) double well state have been measured for the first time. Ground state sodium dimer molecules in a molecular beam are resonantly excited by the doubled output of a 10 ns pulsed dye laser in the range 333-357 nm. After being allowed to decay for a predetermined time interval, the surviving excited molecules are ionized by 532 nm photons from a delayed Nd:YAG laser and detected in a linear time-of-flight mass spectrometer. By appropriate tuning of the excitation laser and systematic variation of the probe laser delay, lifetimes are obtained for vibrational levels in the range from 22 to 57...
November 7, 2016: Journal of Chemical Physics
Charles Tremblay-Darveau, Ross Williams, Paul S Sheeran, Laurent Milot, Matthew Bruce, Peter N Burns
While long Doppler ensembles are, in principle, beneficial for velocity estimates, short acoustic pulses must be used in microbubble contrast-enhanced (CE) Doppler to mitigate microbubble destruction. This introduces inherent tradeoffs in velocity estimates with autocorrelators, which are studied here. A model of the autocorrelation function adapted to the microbubble Doppler signal accounting for transit time, the echo frequency uncertainty, and contrast-agent destruction is derived and validated in vitro...
November 2016: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
G Rohde, A Hendel, A Stange, K Hanff, L-P Oloff, L X Yang, K Rossnagel, M Bauer
An experimental setup for time- and angle-resolved photoelectron spectroscopy with sub-15 fs temporal resolution is presented. A hollow-fiber compressor is used for the generation of 6.5 fs white light pump pulses, and a high-harmonic-generation source delivers 11 fs probe pulses at a photon energy of 22.1 eV. A value of 13 fs full width at half-maximum of the pump-probe cross correlation signal is determined by analyzing a photoemission intensity transient probing a near-infrared interband transition in 1T-TiSe2...
October 2016: Review of Scientific Instruments
S Casaccia, E J Sirevaag, E J Richter, J A O'Sullivan, L Scalise, J W Rohrbaugh
This report amplifies and extends prior descriptions of the use of laser Doppler vibrometry (LDV) as a method for assessing cardiovascular activity, on a non-contact basis. A rebreathing task (n = 35 healthy individuals) was used to elicit multiple effects associated with changes in autonomic drive as well as blood gases including hypercapnia. The LDV pulse was obtained from two sites overlying the carotid artery, separated by 40 mm. A robust pulse signal was obtained from both sites, in accord with the well-described changes in carotid diameter over the blood pressure cycle...
October 2016: Review of Scientific Instruments
Chung-Jui Yu, Michael J Graham, Joseph M Zadrozny, Jens Niklas, Matthew D Krzyaniak, Michael R Wasielewski, Oleg G Poluektov, Danna E Freedman
Quantum information processing (QIP) offers the potential to create new frontiers in fields ranging from quantum biology to cryptography. Two key figures of merit for electronic spin qubits, the smallest units of QIP, are the coherence time (T2), the lifetime of the qubit, and the spin-lattice relaxation time (T1), the thermally defined upper limit of T2. To achieve QIP, processable qubits with long coherence times are required. Recent studies on (Ph4P-d20)2[V(C8S8)3], a vanadium-based qubit, demonstrate that millisecond T2 times are achievable in transition metal complexes with nuclear spin-free environments...
October 31, 2016: Journal of the American Chemical Society
Hirofumi Yanagisawa, Sascha Schnepp, Christian Hafner, Matthias Hengsberger, Dong Eon Kim, Matthias F Kling, Alexandra Landsman, Lukas Gallmann, Jürg Osterwalder
Illuminating a nano-sized metallic tip with ultrashort laser pulses leads to the emission of electrons due to multiphoton excitations. As optical fields become stronger, tunnelling emission directly from the Fermi level becomes prevalent. This can generate coherent electron waves in vacuum leading to a variety of attosecond phenomena. Working at high emission currents where multi-electron effects are significant, we were able to characterize the transition from one regime to the other. Specifically, we found that the onset of laser-driven tunnelling emission is heralded by the appearance of a peculiar delayed emission channel...
October 27, 2016: Scientific Reports
Hans U Stauffer, Sukesh Roy, Jacob B Schmidt, Paul J Wrzesinski, James R Gord
A resonantly enhanced, two-color, femtosecond time-resolved coherent anti-Stokes Raman scattering (CARS) approach is demonstrated and used to explore the nature of the frequency- and time-dependent signals produced by gas-phase nitric oxide (NO). Through careful selection of the input pulse wavelengths, this fully resonant electronically enhanced CARS (FREE-CARS) scheme allows rovibronic-state-resolved observation of time-dependent rovibrational wavepackets propagating on the vibrationally excited ground-state potential energy surface of this diatomic species...
September 28, 2016: Journal of Chemical Physics
William E Perreault, Nandini Mukherjee, Richard N Zare
Stark induced adiabatic Raman passage (SARP) allows us to prepare an appreciable concentration of isolated molecules in a specific, high-lying vibrational level. The process has general applicability, and, as a demonstration, we transfer nearly 100 percent of the HD (v = 0, J = 0) in a supersonically expanded molecular beam of HD molecules to HD (v = 4, J = 0). This is achieved with a sequence of partially overlapping nanosecond pump (355 nm) and Stokes (680 nm) single-mode laser pulses of unequal intensities...
October 21, 2016: Journal of Chemical Physics
Jennyka Hallewell, Tim Reuter, Kim Stanford, Ed Topp, Trevor W Alexander
The goal of this study was to monitor Shiga toxin-producing Escherichia coli (STEC) serogroups and virulence genes in cattle (n = 30) originating from a closed herd. Fecal samples were collected (1) at weaning, (2) upon arrival to a feedlot, (3) after 30 days on feed (DOF), and (4) after 135 DOF. DNA was extracted from feces for detection of virulence and serogroup genes by polymerase chain reaction (PCR) and immunomagnetic separation and pulsed-field gel electrophoresis (PFGE) were performed to collect and subtype STEC isolates...
October 25, 2016: Foodborne Pathogens and Disease
F Zerbib, L Siproudhis, P-A Lehur, C Germain, F Mion, A-M Leroi, B Coffin, A Le Sidaner, V Vitton, C Bouyssou-Cellier, G Chene
BACKGROUND: Open studies have reported favourable results for sacral nerve stimulation in the treatment of refractory constipation. Here, its efficacy was assessed in a double-blind crossover RCT. METHODS: Patients with at least two of the following criteria were included: fewer than three bowel movements per week; straining to evacuate on more than 25 per cent of attempts; or sensation of incomplete evacuation on more than 25 per cent of occasions. Response to therapy was defined as at least three bowel movements per week and/or more than 50 per cent improvement in symptoms...
October 25, 2016: British Journal of Surgery
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