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Pulse transit time

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https://www.readbyqxmd.com/read/28915048/xfel-radiation-damage-through-the-s-state-cycle-of-the-oxygen-evolving-complex-of-photosystem-ii
#1
Muhamed Amin, Mikhail Askerka, Victor S Batista, Gary W Brudvig, Marilyn R Gunner
The oxygen-evolving complex (OEC) of photosystem II (PSII) catalyzes water-splitting through a reaction mechanism that cycles the OEC through five redox states, the 'S-state' intermediates. Understanding structure/function relations of the S-state intermediates is crucial for elucidation of the reaction mechanism and the design of biomimetic catalytic systems. Due to the limitations of conventional X-ray crystallography, serial femtosecond X-ray crystallography has been used to minimize the radiation-damage...
September 15, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28912525/pulse-transit-time-based-continuous-cuffless-blood-pressure-estimation-a-new-extension-and-a-comprehensive-evaluation
#2
Xiaorong Ding, Bryan P Yan, Yuan-Ting Zhang, Jing Liu, Ni Zhao, Hon Ki Tsang
Cuffless technique enables continuous blood pressure (BP) measurement in an unobtrusive manner, and thus has the potential to revolutionize the conventional cuff-based approaches. This study extends the pulse transit time (PTT) based cuffless BP measurement method by introducing a new indicator - the photoplethysmogram (PPG) intensity ratio (PIR). The performance of the models with PTT and PIR was comprehensively evaluated in comparison with six models that are based on sole PTT. The validation conducted on 33 subjects with and without hypertension, at rest and under various maneuvers with induced BP changes, and over an extended calibration interval, respectively...
September 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28904777/how-relative-size-and-abundance-structures-the-relationship-between-size-and-individual-growth-in-an-ontogenetically-piscivorous-fish
#3
Joshua W Chamberlin, Brian R Beckman, Correigh M Greene, Casimir A Rice, Jason E Hall
While individual growth ultimately reflects the quality and quantity of food resources, intra and interspecific interactions for these resources, as well as individual size, may have dramatic impacts on growth opportunity. Out-migrating anadromous salmonids make rapid transitions between habitat types resulting in large pulses of individuals into a given location over a short period, which may have significant impact on demand for local resources. We evaluated the spatial and temporal variation in IGF-1 concentrations (a proxy for growth rate) and the relationship between size and concentration for juvenile Chinook salmon in Puget Sound, WA, USA, as a function of the relative size and abundance of both Chinook salmon and Pacific herring, a species which commonly co-occurs with salmonids in nearshore marine habitats...
September 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28892381/low-temperature-dynamics-of-chain-labelled-lipids-in-ester-and-ether-linked-phosphatidylcholine-membranes
#4
Erika Aloi, Maria Oranges, Rita Guzzi, Rosa Bartucci
Continuous wave electron paramagnetic resonance spectroscopy and two-pulse echo detected spectra of chain-labelled lipids are used to study the dynamics of frozen lipid membranes over the temperature range 77-260 K. Bilayers of ester-linked dihexadecanoyl phosphatidylcholine (DPPC) with noninterdigitated chains and ether-linked dihexadecyl phosphatidylcholine (DHPC) with interdigitated chains are considered. Rapid stochastic librations of small angular amplitude are found in both lipid matrices. In noninterdigitated DPPC bilayers, the mean-square angular amplitude, 〈α^2 〉, of the motion increases with temperature and it is larger close to the chain termini than close to the polar/apolar interface...
September 11, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28886712/the-effect-of-alphacypermethrin-treated-mesh-protection-against-african-horse-sickness-virus-vectors-on-jet-stall-microclimate-clinical-variables-and-faecal-glucocorticoid-metabolites-of-horses
#5
Patrick Page, Andre Ganswindt, Johan Schoeman, Gert Venter, Alan Guthrie
BACKGROUND: African horse sickness (AHS) is of importance to health and international trade in horses worldwide. During export from and transit through AHS endemic countries or zones, physical and chemical measures to protect horses from the vectors of AHS virus (AHSV) are recommended by the World Organization for Animal Health. Protection of containerized air transport systems for horses (jet stalls) with alphacypermethrin insecticide-treated high density polyethylene mesh is effective in reducing the Culicoides midge vector attack rate...
September 9, 2017: BMC Veterinary Research
https://www.readbyqxmd.com/read/28880196/estimation-of-pulse-transit-time-from-radial-pressure-waveform-alone-by-artificial-neural-network
#6
Hanguang Xiao, Mark Butlin, Isabella Tan, Ahmad Qasem, Alberto Avolio
OBJECTIVE: To validate the feasibility of the estimation of pulse transit time (PTT) by artificial neural network (ANN) from radial pressure waveform alone. METHODS: A cascade ANN with ten-fold cross validation was applied to invasively and simultaneously recorded aortic and radial pressure waveforms during rest and nitroglycerin infusion (n=62) for the estimation of mean and beat-to-beat PTT. The results of the ANN models were compared to a multiple linear regression (LR) model when the features of radial arterial pressure waveform in time and frequency domains were used as the predictors of the models...
September 1, 2017: IEEE Journal of Biomedical and Health Informatics
https://www.readbyqxmd.com/read/28872320/reassessing-graphene-absorption-and-emission-spectroscopy
#7
Yuan Yang, Grigory Kolesov, Lucas Kocia, Eric J Heller
We present a new paradigm for understanding optical absorption and hot electron dynamics experiments in graphene. Our analysis pivots on assigning proper importance to phonon-assisted indirect processes and bleaching of direct processes. We show indirect processes figure in the excess absorption in the UV region. Experiments which were thought to indicate ultrafast relaxation of electrons and holes, reaching a thermal distribution from an extremely nonthermal one in under 5-10 fs, instead are explained by the nascent electron and hole distributions produced by indirect transitions...
September 8, 2017: Nano Letters
https://www.readbyqxmd.com/read/28866598/a-magnetic-plethysmograph-probe-for-local-pulse-wave-velocity-measurement
#8
Nabeel P M, Jayaraj Joseph, Mohanasankar Sivaprakasam
OBJECTIVE: We present the design and experimental validation of an arterial compliance probe with dual magnetic plethysmograph (MPG) transducers for local pulse wave velocity (PWV) measurement. The MPG transducers (positioned at 23 mm distance apart) utilizes Hall-effect sensors and permanent magnets for arterial blood pulse detection. METHODS: The MPG probe was initially validated on an arterial flow phantom using a reference method. Further, 20 normotensive subjects (14 males, age = 24 ± 3...
August 29, 2017: IEEE Transactions on Biomedical Circuits and Systems
https://www.readbyqxmd.com/read/28865347/time-varying-assessment-of-heart-rate-variability-parameters-using-respiratory-information
#9
Layli S Goldoozian, Edmond Zahedi, Vicente Zarzoso
Analysis of heart rate variability (HRV) is commonly used for characterization of autonomic nervous system. As high frequency (HF, known as the respiratory-related) component of HR, overlaps with the typical low frequency (LF) band when the respiratory rate is low, a reference signal for HF variations would help in better discriminating the LF and HF components of HR. The present study proposes a model for time-varying separation of HRV components as well as estimation of HRV parameters using respiration information...
August 1, 2017: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/28857749/direct-means-of-obtaining-cavi-sub-0-sub-a-corrected-cardio-ankle-vascular-stiffness-index-cavi-from-conventional-cavi-measurements-or-their-underlying-variables
#10
Bart Spronck, Michal Mestanik, Ingrid Tonhajzerova, Alexander Jurko, Tomas Jurko, Alberto P Avolio, Mark Butlin
<b>Objective</b> Cardio-ankle vascular index (CAVI) as measured using the VaSera device (CAVI<sub>VS</sub>, Fukuda Denshi), has been proposed as a stiffness index that does not depend on blood pressure. We have recently shown theoretically that CAVI<sub>VS</sub> still exhibits blood pressure dependence, and proposed the corrected index, CAVI<sub>0</sub>. The present study aims to establish a method of calculating CAVI<sub>0</sub> either (i) from VaSera-reported values of cardiac-brachial and brachial-ankle pulse transit times (tb and tba, respectively) and blood pressure, or (ii) directly from CAVI<sub>VS</sub>...
August 31, 2017: Physiological Measurement
https://www.readbyqxmd.com/read/28837266/covalent-dimerization-of-interleukin-like-epithelial-to-mesenchymal-transition-emt-inducer-ilei-facilitates-emt-invasion-and-late-aspects-of-metastasis
#11
Maria Kral, Christoph Klimek, Betül Kutay, Gerald Timelthaler, Thomas Lendl, Benjamin Neuditschko, Christopher Gerner, Maria Sibilia, Agnes Csiszar
The interleukin-like epithelial-to-mesenchymal transition (EMT) inducer (ILEI)/FAM3C is a member of the highly homologous FAM3 family and is essential for EMT and metastasis formation. It is upregulated in several cancers, and its altered subcellular localization strongly correlates with poor survival. However, the mechanism of ILEI action, including the structural requirements for ILEI activity, remains elusive. Here, we show that ILEI formed both monomers and covalent dimers in cancer cell lines and in tumors...
August 24, 2017: FEBS Journal
https://www.readbyqxmd.com/read/28831258/which-psychological-psychophysiological-and-anthropometric-factors-are-connected-with-life-events-depression-and-quality-of-life-in-patients-with-cardiovascular-disease
#12
Milos Slepecky, Antonia Kotianova, Jan Prasko, Ivan Majercak, Erika Gyorgyova, Michal Kotian, Marta Zatkova, Marta Popelkova, Marie Ociskova, Ingrid Tonhajzerova
OBJECTIVE: The aim of the study was to determine psychological, psychophysiological, and anthropometric factors connected with life events, level of depression, and quality of life in people at risk for cardiovascular disease and healthy controls. METHODS: This is a cross-sectional study involving arterial hypertension patients and healthy controls. There were several measurements including physical, anthropological, cardiovascular, and psychophysiological measurements and administration of questionnaires...
2017: Neuropsychiatric Disease and Treatment
https://www.readbyqxmd.com/read/28828627/nocturnal-blood-pressure-fluctuations-measured-by-using-pulse-transit-time-in-patients-with-severe-obstructive-sleep-apnea-syndrome
#13
Jennifer Gehring, Heiko Gesche, Gesine Drewniok, Gert Küchler, Andreas Patzak
BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is related to arterial hypertension. In the present study, we test the hypothesis that patients with severe OSAS have excessive apnea induced blood pressure (BP). METHODS: We investigated 97 patients with an apnea/hypopnea index (AHI) greater than 30. Systolic BP (SBP) was continuously determined by using the pulse transit time (PTT). Apnea/hypopnea induced nocturnal BP fluctuations (NBPFs) were detected and showed phenomena of continuous increases of the SBP baseline...
August 22, 2017: Sleep & Breathing, Schlaf & Atmung
https://www.readbyqxmd.com/read/28825731/mott-transition-by-an-impulsive-dielectric%C3%A2-breakdown
#14
H Yamakawa, T Miyamoto, T Morimoto, T Terashige, H Yada, N Kida, M Suda, H M Yamamoto, R Kato, K Miyagawa, K Kanoda, H Okamoto
The transition of a Mott insulator to metal, the Mott transition, can occur via carrier doping by elemental substitution, and by photoirradiation, as observed in transition-metal compounds and in organic materials. Here, we show that the application of a strong electric field can induce a Mott transition by a new pathway, namely through impulsive dielectric breakdown. Irradiation of a terahertz electric-field pulse on an ET-based compound, κ-(ET) 2Cu[N(CN) 2]Br (ET:bis(ethylenedithio)tetrathiafulvalene), collapses the original Mott gap of ∼30 meV with a ∼0...
August 21, 2017: Nature Materials
https://www.readbyqxmd.com/read/28819942/study-of-the-relationship-between-ages-and-oxidative-stress-damage-to-trophoblast-cell-mitochondria
#15
Lingling Jiang, Jianying Yan, Lixiang Wu
OBJECTIVES: To study the influence of AGEs on placental trophoblast mitochondria oxidative stress, and to explore the possible pathogenesis which may participate in pre-eclampsia. MATERIAL AND METHODS: Human trophoblast cells from early pregnancy were cultured by an enzyme-digestion method. When trophoblast cells reached approximately 70-80% after passages, they were incubated with pre-eclampsia serum for 24 hours. A fluorescent dye assay was applied to measure the mitochondrial membrane potential; ELISA was used to measure the activity of the mitochondrial permeability transition pore...
2017: Ginekologia Polska
https://www.readbyqxmd.com/read/28816177/electrical-stimulation-of-gut-motility-guided-by-an-in-silico-model
#16
Bradley Brigham Barth, Craig S Henriquez, Warren M Grill, Xiling Shen
OBJECTIVE: Neuromodulation of the central and peripheral nervous systems is becoming increasingly important for treating a diverse set of diseases-ranging from Parkinson's Disease and epilepsy to chronic pain. However, neuromodulation of the gastrointestinal (GI) tract has achieved relatively limited success in treating functional GI disorders, which affect a significant population, because the effects of stimulation on the enteric nervous system (ENS) and gut motility are not well understood...
August 17, 2017: Journal of Neural Engineering
https://www.readbyqxmd.com/read/28810753/dynamical-transition-in-molecular-glasses-and-proteins-observed-by-spin-relaxation-of-nitroxide-spin-probes-and-labels
#17
Elena A Golysheva, Georgiy Yu Shevelev, Sergei A Dzuba
In glassy substances and biological media, dynamical transitions are observed in neutron scattering that manifests itself as deviations of the translational mean-squared displacement, 〈x(2)〉, of hydrogen atoms from harmonic dynamics. In biological media, the deviation occurs at two temperature intervals, at ∼100-150 K and at ∼170-230 K, and it is attributed to the motion of methyl groups in the former case and to the transition from harmonic to anharmonic or diffusive motions in the latter case. In this work, electron spin echo (ESE) spectroscopy-a pulsed version of electron paramagnetic resonance-is applied to study the spin relaxation of nitroxide spin probes and labels introduced in molecular glass former o-terphenyl and in protein lysozyme...
August 14, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28783442/a-literature-review-on-current-and-proposed-technologies-of-noninvasive-blood-pressure-measurement
#18
Ramtanu Mukherjee, Sanchita Ghosh, Bharat Gupta, Tapas Chakravarty
BACKGROUND: Noninvasive continuous blood pressure (BP) measurement has become an evolving topic in the field of remote healthcare. The classical noninvasive BP measurement techniques provide spontaneous values of systolic and diastolic BP. On the other hand, intrusive type BP measurement techniques provide continuous values of systolic and diastolic BP. However, these techniques are very painful, cannot be used for long-term monitoring, and are obtainable only in an intensive care unit environment...
August 7, 2017: Telemedicine Journal and E-health: the Official Journal of the American Telemedicine Association
https://www.readbyqxmd.com/read/28769817/suicidal-ideation-is-associated-with-altered-variability-of-fingertip-photo-plethysmogram-signal-in-depressed-patients
#19
Ahsan H Khandoker, Veena Luthra, Yousef Abouallaban, Simanto Saha, Khawza I U Ahmed, Raqibul Mostafa, Nayeefa Chowdhury, Herbert F Jelinek
Physiological and psychological underpinnings of suicidal behavior remain ill-defined and lessen timely diagnostic identification of this subgroup of patients. Arterial stiffness is associated with autonomic dysregulation and may be linked to major depressive disorder (MDD). The aim of this study was to investigate the association between arterial stiffness by photo-plethysmogram (PPG) in MDD with and without suicidal ideation (SI) by applying multiscale tone entropy (T-E) variability analysis. Sixty-one 10-min PPG recordings were analyzed from 29 control, 16 MDD patients with (MDDSI+) and 16 patients without SI (MDDSI-)...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28764344/time-domain-simulation-of-gd-3-gd-3-distance-measurements-by-epr
#20
Nurit Manukovsky, Akiva Feintuch, Ilya Kuprov, Daniella Goldfarb
Gd(3+)-based spin labels are useful as an alternative to nitroxides for intramolecular distance measurements at high fields in biological systems. However, double electron-electron resonance (DEER) measurements using model Gd(3+) complexes featured a low modulation depth and an unexpected broadening of the distance distribution for short Gd(3+)-Gd(3+) distances, when analysed using the software designed for S = 1/2 pairs. It appears that these effects result from the different spectroscopic characteristics of Gd(3+)-the high spin, the zero field splitting (ZFS), and the flip-flop terms in the dipolar Hamiltonian that are often ignored for spin-1/2 systems...
July 28, 2017: Journal of Chemical Physics
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