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https://www.readbyqxmd.com/read/28636342/charge-transfer-properties-of-triarylamine-integrated-dimolybdenum-dyads
#1
Lu Chen, Suman Mallick, Ying Ning Tan, Miao Meng, Chun Y Liu
Three quadruply bonded dimolybdenum complexes equipped with a triarylamine pendant, [(DAniF)3Mo2(μ-O2CC6H4N(C6H4CH3)2] (DAniF = N,N'-di(p-anisyl)formamidinate; [OO-ph-N]), [(DAniF)3Mo2(μ-OSCC6H4N(C6H4CH3)2] ([OS-ph-N]), and [(DAniF)3Mo2(μ-S2CC6H4N(C6H4CH3)2] ([SS-ph-N]), have been synthesized and characterized by single crystal X-ray diffraction. In electrochemical measurements, the redox couple for the organic amine group becomes irreversible, reflecting the substantially strong electronic interaction between the dimetal center and organic redox site...
June 21, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28631853/high-sensitivity-mr-acoustic-radiation-force-imaging-using-transition-band-balanced-steady-state-free-precession
#2
Yuan Zheng, Michael Marx, G Wilson Miller, Kim Butts Pauly
PURPOSE: MR acoustic radiation force imaging (MR-ARFI) provides a method to visualize the focal spot of a focused ultrasound (FUS) beam without introducing a significant temperature rise. With conventional spoiled MR-ARFI pulse sequences, the ARFI phase always equals the motion-encoded phase. In this work, MR-ARFI using transition band balanced steady-state free precession (bSSFP) is presented, which improves the sensitivity of MR-ARFI with high acquisition speed. THEORY AND METHODS: Motion-encoding gradients (MEG) are inserted into bSSFP sequences for MR-ARFI...
June 20, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28630909/dynamic-fracture-of-tantalum-under-extreme-tensile-stress
#3
Bruno Albertazzi, Norimasa Ozaki, Vasily Zhakhovsky, Anatoly Faenov, Hideaki Habara, Marion Harmand, Nicholas Hartley, Denis Ilnitsky, Nail Inogamov, Yuichi Inubushi, Tetsuya Ishikawa, Tetsuo Katayama, Takahisa Koyama, Michel Koenig, Andrew Krygier, Takeshi Matsuoka, Satoshi Matsuyama, Emma McBride, Kirill Petrovich Migdal, Guillaume Morard, Haruhiko Ohashi, Takuo Okuchi, Tatiana Pikuz, Narangoo Purevjav, Osami Sakata, Yasuhisa Sano, Tomoko Sato, Toshimori Sekine, Yusuke Seto, Kenjiro Takahashi, Kazuo Tanaka, Yoshinori Tange, Tadashi Togashi, Kensuke Tono, Yuhei Umeda, Tommaso Vinci, Makina Yabashi, Toshinori Yabuuchi, Kazuto Yamauchi, Hirokatsu Yumoto, Ryosuke Kodama
The understanding of fracture phenomena of a material at extremely high strain rates is a key issue for a wide variety of scientific research ranging from applied science and technological developments to fundamental science such as laser-matter interaction and geology. Despite its interest, its study relies on a fine multiscale description, in between the atomic scale and macroscopic processes, so far only achievable by large-scale atomic simulations. Direct ultrafast real-time monitoring of dynamic fracture (spallation) at the atomic lattice scale with picosecond time resolution was beyond the reach of experimental techniques...
June 2017: Science Advances
https://www.readbyqxmd.com/read/28630331/distinguishing-attosecond-electron-electron-scattering-and-screening-in-transition-metals
#4
Cong Chen, Zhensheng Tao, Adra Carr, Piotr Matyba, Tibor Szilvási, Sebastian Emmerich, Martin Piecuch, Mark Keller, Dmitriy Zusin, Steffen Eich, Markus Rollinger, Wenjing You, Stefan Mathias, Uwe Thumm, Manos Mavrikakis, Martin Aeschlimann, Peter M Oppeneer, Henry Kapteyn, Margaret Murnane
Electron-electron interactions are the fastest processes in materials, occurring on femtosecond to attosecond timescales, depending on the electronic band structure of the material and the excitation energy. Such interactions can play a dominant role in light-induced processes such as nano-enhanced plasmonics and catalysis, light harvesting, or phase transitions. However, to date it has not been possible to experimentally distinguish fundamental electron interactions such as scattering and screening. Here, we use sequences of attosecond pulses to directly measure electron-electron interactions in different bands of different materials with both simple and complex Fermi surfaces...
June 19, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28629074/tunable-green-graphene-silk-biomaterials-mechanism-of-protein-based-nanocomposites
#5
Fang Wang, S S Jyothirmayee Aravind, Hao Wu, Joseph Forys, Venkat Venkataraman, Kandalam Ramanujachary, Xiao Hu
Green graphene materials prepared by photoreduction of graphite oxide were first time blended with aqueous-based silk fibroin proteins to improve the mechanical and thermal properties of silk biomaterials, and their nanocomposite interaction mechanism was illustrated. Powder X-ray diffraction (XRD) analysis confirmed the complete exfoliation of graphite oxide to graphene in presence of focused pulses of solar radiation. By varying the concentration of graphene (0.1wt% to 10wt%), a series of free standing graphene-silk films were prepared and were systematically characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and nanoindentation measurements...
October 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28598912/cardiac-output-measurements-based-on-the-pulse-wave-transit-time-and-thoracic-impedance-exhibit-limited-agreement-with-thermodilution-method-during-orthotopic-liver-transplantation
#6
Aurora Magliocca, Emanuele Rezoagli, Thomas Anthony Anderson, Sara Maria Burns, Fumito Ichinose, Hovig Vatche Chitilian
BACKGROUND: Orthotopic liver transplantation (OLT) is characterized by significant intraoperative hemodynamic variability. Accurate and real-time cardiac output (CO) monitoring aids clinical decision making during OLT. The purpose of this study is to compare accuracy, precision, and trending ability of CO estimation obtained noninvasively using pulse wave transit time (estimated continuous cardiac output [esCCO; Nihon Kohden, Tokyo, Japan]) or thoracic bioimpedance (ICON; Osypka Medical GmbH, Berlin, Germany) to thermodilution cardiac output (TDCO) measured with a pulmonary artery catheter...
June 8, 2017: Anesthesia and Analgesia
https://www.readbyqxmd.com/read/28595406/an-alternative-laser-driven-photodissociation-mechanism-of-pyrrole-via-%C3%AF-%C3%AF-1%C3%A2-s0-conical-intersection
#7
K R Nandipati, Z Lan, H Singh, S Mahapatra
A first principles quantum dynamics study of N-H photodissociation of pyrrole on the S0-(1)πσ(*)(A21) coupled electronic states is carried out with the aid of an optimally designed UV-laser pulse. A new photodissociation path, as compared to the conventional barrier crossing on the πσ*1 state, opens up upon electronic transitions under the influence of pump-dump laser pulses, which efficiently populate both the dissociation channels. The interplay of electronic transitions due both to vibronic coupling and the laser pulse is observed in the control mechanism and discussed in detail...
June 7, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28571463/a-q-band-low-noise-gaas-phemt-mmic-power-amplifier-for-pulse-electron-spin-resonance-spectrometer
#8
A Sitnikov, E Kalabukhova, V Oliynyk, M Kolisnichenko
We present the design and development of a single stage pulse power amplifier working in the frequency range 32-38 GHz based on a monolithic microwave integrated circuit (MMIC). We have designed the MMIC power amplifier by using the commercially available packaged GaAs pseudomorphic high electron mobility transistor. The circuit fabrication and assembly process includes the elaboration of the matching networks for the MMIC power amplifier and their assembling as well as the topology outline and fabrication of the printed circuit board of the waveguide-microstrip line transitions...
May 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28571411/a-practical-superconducting-microcalorimeter-x-ray-spectrometer-for-beamline-and-laboratory-science
#9
W B Doriese, P Abbamonte, B K Alpert, D A Bennett, E V Denison, Y Fang, D A Fischer, C P Fitzgerald, J W Fowler, J D Gard, J P Hays-Wehle, G C Hilton, C Jaye, J L McChesney, L Miaja-Avila, K M Morgan, Y I Joe, G C O'Neil, C D Reintsema, F Rodolakis, D R Schmidt, H Tatsuno, J Uhlig, L R Vale, J N Ullom, D S Swetz
We describe a series of microcalorimeter X-ray spectrometers designed for a broad suite of measurement applications. The chief advantage of this type of spectrometer is that it can be orders of magnitude more efficient at collecting X-rays than more traditional high-resolution spectrometers that rely on wavelength-dispersive techniques. This advantage is most useful in applications that are traditionally photon-starved and/or involve radiation-sensitive samples. Each energy-dispersive spectrometer is built around an array of several hundred transition-edge sensors (TESs)...
May 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28571407/development-of-a-linear-type-double-reflectron-for-focused-imaging-of-photofragment-ions-from-mass-selected-complex-ions
#10
Kenichi Okutsu, Yuji Nakashima, Kenichiro Yamazaki, Keita Fujimoto, Motoyoshi Nakano, Keijiro Ohshimo, Fuminori Misaizu
An ion imaging apparatus with a double linear reflectron mass spectrometer has been developed, in order to measure velocity and angular distributions of mass-analyzed fragment ions produced by photodissociation of mass-selected gas phase complex ions. The 1st and the 2nd linear reflectrons were placed facing each other and controlled by high-voltage pulses in order to perform the mass-separation of precursor ions in the 1st reflectron and to observe the focused image of the photofragment ions in the 2nd reflectron...
May 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28566742/dynamic-control-of-coherent-pulses-via-destructive-interference-in-graphene-under-landau-quantization
#11
Wen-Xing Yang, Ai-Xi Chen, Xiao-Tao Xie, Shaopeng Liu, Shasha Liu
We analyze the destructive interference in monolayer graphene under Landau quantization in a time-dependent way by using the Bloch-Maxwell formalism. Based on this analysis, we investigate the dynamics control of an infrared probe and a terahertz (THz) switch pulses in graphene. In presence of the THz switch pulse, the destructive interference take places and can be optimized so that the monolayer graphene is completely transparent to the infrared probe pulse. In absence of the THz switch pulse, however, the infrared probe pulse is absorbed due to such a interference does not take place...
May 31, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28542010/thermal-modeling-for-the-next-generation-of-radiofrequency-exposure-limits-commentary
#12
Kenneth R Foster, Marvin C Ziskin, Quirino Balzano
This commentary evaluates two sets of guidelines for human exposure to radiofrequency (RF) energy, focusing on the frequency range above the "transition" frequency at 3-10 GHz where the guidelines change their basic restrictions from specific absorption rate to incident power density, through the end of the RF band at 300 GHz. The analysis is based on a simple thermal model based on Pennes' bioheat equation (BHTE) (Pennes 1948) assuming purely surface heating; an Appendix provides more details about the model and its range of applicability...
July 2017: Health Physics
https://www.readbyqxmd.com/read/28541911/robust-sensing-of-distal-pulse-waveforms-on-a-modified-weighing-scale-for-ubiquitous-pulse-transit-time-measurement
#13
Andrew M Carek, Omer T Inan
The measurement of aortic pulse transit time (PTT), the time for the arterial pulse wave to travel from the carotid to the femoral artery, can provide valuable insight into cardiovascular health, specifically regarding arterial stiffness and blood pressure (BP). To measure aortic PTT, both proximal and distal arterial pulse timings are required. Recently, our group has demonstrated that the ballistocardiogram signal measured on a modified weighing scale can provide an unobtrusive, yet accurate, means of obtaining a proximal timing reference; however, there are no convenient, reliable methods to extract the distal timing from a subject standing on the modified weighing scale...
May 23, 2017: IEEE Transactions on Biomedical Circuits and Systems
https://www.readbyqxmd.com/read/28536197/melting-dynamics-of-ice-in-the-mesoscopic-regime
#14
Margherita Citroni, Samuele Fanetti, Naomi Falsini, Paolo Foggi, Roberto Bini
How does a crystal melt? How long does it take for melt nuclei to grow? The melting mechanisms have been addressed by several theoretical and experimental works, covering a subnanosecond time window with sample sizes of tens of nanometers and thus suitable to determine the onset of the process but unable to unveil the following dynamics. On the other hand, macroscopic observations of phase transitions, with millisecond or longer time resolution, account for processes occurring at surfaces and time limited by thermal contact with the environment...
June 6, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28532415/hemodynamic-changes-caused-by-acupuncture-in-healthy-volunteers-a-prospective-single-arm-exploratory-clinical-study
#15
Tae-Hun Kim, Boncho Ku, Jang-Han Bae, Jae-Young Shin, Min-Ho Jun, Jung Won Kang, Junghwan Kim, Jun-Hwan Lee, Jaeuk U Kim
BACKGROUND: Radial pressure pulse wave (RPPW) examination has been a key diagnostic component of traditional Chinese medicine. The objective of this study was to investigate the changes in RPPW along with various hemodynamic variables after acupuncture stimulation and to examine the validity of pulse diagnosis as a modern diagnostic tool. METHODS: We conducted acupuncture stimulation at both ST36 acupuncture points in 25 healthy volunteers. We simultaneously assessed the RPPW by pulse tonometry; heart rate variability (HRV) by electrocardiogram; photoplethysmogram (PPG) signals, respiration rate, peripheral blood flow velocity and arterial depth by ultrasonography; and cardiac output by impedance cardiography, before, during and after a session of acupuncture stimulation...
May 22, 2017: BMC Complementary and Alternative Medicine
https://www.readbyqxmd.com/read/28531140/a-cuffless-blood-pressure-measurement-based-on-the-impedance-plethysmography-technique
#16
Shing-Hong Liu, Da-Chuan Cheng, Chun-Hung Su
In the last decade, cuffless blood pressure measurement technology has been widely studied because it could be applied to a wearable apparatus. Electrocardiography (ECG), photo-plethysmography (PPG), and phonocardiography are always used to detect the pulse transit time (PTT) because the changed tendencies of the PTT and blood pressure have a negative relationship. In this study, the PPG signal was replaced by the impedance plethysmography (IPG) signal and was used to detect the PTT. The placement and direction of the electrode array for the IPG measurement were discussed...
May 21, 2017: Sensors
https://www.readbyqxmd.com/read/28520843/measurement-of-aortic-pulse-wave-velocity-with-a-connected-bathroom-scale
#17
David Campo, Hakim Khettab, Roger Yu, Nicolas Genain, Paul Edouard, Nadine Buard, Pierre Boutouyrie
BACKGROUND: Measurement of arterial stiffness should be more available. Our aim was to show that aortic pulse wave velocity can be reliably measured with a bathroom scale combining the principles of ballistocardiography (BCG) and impedance plethysmography on a single foot. METHOD: The calibration of the bathroom scale was conducted on a group of 106 individuals. The aortic pulse wave velocity was measured with the SphygmoCor in the supine position. Three consecutive measurements were then performed on the Withings scale in the standing position...
May 17, 2017: American Journal of Hypertension
https://www.readbyqxmd.com/read/28501714/determination-of-polymer-crystallinity-by-the-multivariable-curve-resolution-method-in-13-c-solid-nmr-spectrum
#18
Xiaoyue Zhou, Kaipin Xu, Pei Ni, Qun Chen, Shanmin Zhang
Most of the polymers are composed of a crystal part, an amorphous part, and a transitional interfacial part. These components present disparate physical and chemical characteristics. However, it always suffers from peak overlapping in solid NMR spectrum in order to acquire polymer's crystallinity. The polyethylene oxide (PEO) sample was tested using the Torchia pulse sequence combined with the Multivariate Curve Resolution (MCR) method. A two dimensional CP/MAS spectrum containing spin-lattice relaxation time (T1) information was acquired...
September 2017: Solid State Nuclear Magnetic Resonance
https://www.readbyqxmd.com/read/28497192/redox-changes-of-ferredoxin-p700-and-plastocyanin-measured-simultaneously-in-intact-leaves
#19
Ulrich Schreiber
Properties and performance of the recently introduced Dual/KLAS-NIR spectrophotometer for simultaneous measurements of ferredoxin (Fd), P700, and plastocyanin (PC) redox changes, together with whole leaf chlorophyll a (Chl) fluorescence (emission >760, 540 nm excitation) are outlined. Spectral information on in vivo Fd, P700, and PC in the near-infrared region (NIR, 780-1000 nm) is presented, on which the new approach is based. Examples of application focus on dark-light and light-dark transitions, where maximal redox changes of Fd occur...
May 11, 2017: Photosynthesis Research
https://www.readbyqxmd.com/read/28476975/peripheral-arterial-disease-screening-for-hemodialysis-patients-using-a-fractional-order-integrator-and-transition-probability-decision-making-model
#20
Jian-Xing Wu, Chien-Ming Li, Guan-Chun Chen, Yueh-Ren Ho, Chia-Hung Lin
Atherosclerosis and resultant peripheral arterial disease (PAD) are common complications in patients with type 2 diabetes mellitus or end-stage renal disease and in elderly patients. The prevalence of PAD is higher in patients receiving haemodialysis therapy. For early assessment of arterial occlusion using bilateral photoplethysmography (PPG), such as changes in pulse transit time and pulse shape, bilateral timing differences could be used to identify the risk level of PAD. Hence, the authors propose a discrete fractional-order integrator to calculate the bilateral area under the systolic peak (AUSP)...
April 2017: IET Systems Biology
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