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Jie Shao, Zhiquan Deng, Yu Gu
This paper proposes a new sensorless control approach for switched reluctance motor (SRM) in the single pulse control mode in high speed operation. The sensorless method uses the cross point position of transformer electromotive force (EMF) and motional back electromotive force (BEMF) to estimate the rotor position. The cross point position can be derived from the inductance model of SRM, and it is regarded as reference position. The rotor position can be calculated by detecting the special position for each electrical cycle...
August 9, 2017: ISA Transactions
F Daniel Ramirez, David H Birnie, Girish M Nair, Agnieszka Szczotka, Calum J Redpath, Mouhannad M Sadek, Pablo B Nery
INTRODUCTION: Targeting localized drivers (electrical rotors or focal impulses) during catheter ablation for atrial fibrillation (AF) has been proposed as a strategy to improve procedural success. However, the strength and quality of the evidence to support this approach is unclear. METHODS AND RESULTS: Clinical studies reporting efficacy or safety outcomes of driver-guided ablation for AF were identified in Medline, Embase, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, Pubmed, and conference abstracts from major scientific meetings...
August 11, 2017: Journal of Cardiovascular Electrophysiology
Hans Kottkamp, Fabian Moser, Andreas Rieger, Doreen Schreiber, Christian Pönisch, Monica Trofin
INTRODUCTION: One question for the technological advancement of catheter ablation of atrial fibrillation (AF) is whether a creative new concept can combine and even improve the diagnostic mapping options of single-tip and basket catheters with the simplicity of the use of balloon catheters for ablation. Herein, we describe the first in-human experience with a single catheter offering such a complete solution. METHODS AND RESULTS: A new catheter (Globe®) with a distal multi-electrode array consisting of 16 ribs with 122 gold-plated electrodes was used...
August 11, 2017: Journal of Cardiovascular Electrophysiology
Christopher P McNary, P B Armentrout
Threshold collision-induced dissociation using a guided ion beam tandem mass spectrometer is performed on (N2H4)H(+)(H2O)n, where n = 1 and 2, and on the protonated unsymmetrical 1,1-dimethylhydrazine one-water complex. The primary dissociation pathway for all clusters is a loss of a single water molecule, which for n = 2 is followed by the sequential loss of an additional water molecule at higher collision energies. The data are analyzed using a statistical model after accounting for internal and kinetic energy distributions, multiple collisions, and kinetic shifts to obtain 0 K bond dissociation energies (BDEs)...
December 7, 2016: Journal of Chemical Physics
Yamini S Avadhut, Johannes Weber, Jörn Schmedt Auf der Günne
An improved implementation of single-crystal magic-angle-spinning (MAS) NMR is presented which gives access to chemical shift tensors both in orientation (relative to the crystal axis system) and principal axis values. For mounting arbitrary crystals inside ordinary MAS rotors, a mounting tool is described which allows to relate the crystal orientation determined by diffraction techniques to the rotor coordinate system. The crystal is finally mounted into a MAS rotor equipped with a special insert which allows a defined reorientation of the single-crystal by 90°...
July 24, 2017: Journal of Magnetic Resonance
Li-Wei Lo, Yenn-Jiang Lin, Shih-Lin Chang, Yu-Feng Hu, Fa-Po Chung, Shih-Ann Chen
PURPOSE OF REVIEW: Pulmonary vein (PV) isolation is the cornerstone of atrial fibrillation (AF) ablation. However, the long-term procedural outcome remains suboptimal and there is a frequent need for repeat ablation procedure, especially in patients with non-paroxysmal AF. The review article summarizes the rationales, recent evidences, and strategies of ablation of extra-PV sites and its clinical outcomes. RECENT FINDINGS: It is a consensus that durable PV isolations are a definite therapy in patients with paroxysmal AF...
August 9, 2017: Current Cardiology Reports
Ashley A Beckstead, Yuyuan Zhang, Jonathan K Hilmer, Heidi J Smith, Emily Bermel, Christine M Foreman, Bern Kohler
The photophysical properties of the natural pigment violacein extracted from an Antarctic organism adapted to high exposure levels of UV radiation were measured in a combined steady-state and time-resolved spectroscopic study for the first time. In the low-viscosity solvents methanol and acetone, violacein exhibits low fluorescence quantum yields on the order of 1 × 10(-4), and femtosecond transient absorption measurements reveal excited-state lifetimes of 3.2 ± 0.2 and 4.5 ± 0.2 ps in methanol and acetone, respectively...
August 9, 2017: Journal of Physical Chemistry. B
Christian Sohns, Christine Lemes, Andreas Metzner, Thomas Fink, Mikhail Chmelevsky, Tilman Maurer, Margarita Budanova, Vladislav Solntsev, Walther H W Schulze, Wieland Staab, Shibu Mathew, Christian Heeger, Bruno Reißmann, Eugene Kholmovski, Dietmar Kivelitz, Feifan Ouyang, Karl-Heinz Kuck
BACKGROUND: Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging can be used to evaluate characteristics of atrial fibrosis. The novel noninvasive epicardial and endocardial electrophysiology system (NEEES) allows for the identification of sources with rotor activity. This study describes a new technique to examine the relationship between rotors and LGE signal intensity in patients with persistent atrial fibrillation (PERS) scheduled for ablation. METHODS AND RESULTS: Ten consecutive patients underwent pulmonary vein isolation for persistent atrial fibrillation...
August 2017: Circulation. Arrhythmia and Electrophysiology
Mirko Borelli, Giuseppe Iasilli, Pierpaolo Minei, Andrea Pucci
Thin films of styrene copolymers containing fluorescent molecular rotors were demonstrated to be strongly sensitive to volatile organic compounds (VOCs). Styrene copolymers of 2-[4-vinyl(1,1'-biphenyl)-4'-yl]-cyanovinyljulolidine (JCBF) were prepared with different P(STY-co-JCBF)(m) compositions (m% = 0.10-1.00) and molecular weights of about 12,000 g/mol. Methanol solutions of JCBF were not emissive due to the formation of the typical twisted intramolecular charge transfer (TICT) state at low viscosity regime, which formation was effectively hampered by adding progressive amounts of glycerol...
August 6, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Guang-Mao Liu, Dong-Hai Jin, Jian-Ye Zhou, Xi-Hang Jiang, Han-Song Sun, Yan Zhang, Hai-Bo Chen, Sheng-Shou Hu, Xing-Min Gui
A fully implantable axial left ventricular assist device LAP31 was developed for Chinese or other heart failure patients who need partial support. Based on the 5-Lpm total cardiac blood output of Chinese without heart failure disease, the design point of LAP31 was set to a flow rate of 3 Lpm with 100-mmHg pressure head. To achieve the required pressure head and good hemolytic performance, a structure that includes a spindly rotor hub and a diffuser with splitter and cantilevered main blades was developed. Computational fluid dynamics (CFD) was used to analyze the hydraulic and hemodynamic performance of LAP31...
August 2, 2017: International Journal of Artificial Organs
Mark Evans
The aims of this paper were to: (a) demonstrate how iso-thermal plots of the Wilshire equation can be used to identify the correct structure of this equation (which in turn enables a meaningful description of the creep mechanism involved in deformation to be made); and (b) show how a generalized specification of batch to batch variation could produce less conservative predictions of the time to failure associated with a given degree of risk. Such predictions were obtained using maximum likelihood estimation of the parameters of a generalised F distribution...
May 24, 2017: Materials
Yong Yan, Daniil I Kolokolov, Ivan da Silva, Alexander G Stepanov, Alexander J Blake, Anne Dailly, Pascal Manuel, Chiu C Tang, Sihai Yang, Martin Schröder
Natural gas (methane, CH4) is widely considered as a promising energy carrier for mobile applications. Maximising the storage capacity is the primary goal for the design of future storage media. Here we report the CH4 storage properties in a family of isostructural (3,24)-connected porous materials, MFM-112a, MFM-115a and MFM-132a with different linker backbone functionalisation. Both MFM-112a and MFM-115a show excellent CH4 uptakes of 236 and 256 cm3 (STP) cm-3 (v/v) at 80 bar and room temperature, respectively...
August 3, 2017: Journal of the American Chemical Society
Junjun Wu, Fethi Khaled, Hongbo Ning, Liuhao Ma, Aamir Farooq, Wei Ren
We report a systematic chemical kinetics study of the H-atom abstractions from ethyl formate (EF) by H, O(3P), CH3, OH, and HO2 radicals. The geometry optimization and frequency calculation of all the species were conducted using the M06 method and the cc-pVTZ basis set. The one-dimensional hindered rotor treatment of the reactants and transition states and the intrinsic reaction coordinate analysis were also performed at the M06/cc-pVTZ level of theory. The relative electronic energies were calculated at the CCSD(T)/cc-pVXZ (where X = D, T) level of theory and further extrapolated to the complete basis set limit...
August 3, 2017: Journal of Physical Chemistry. A
Nghia Tuan Duong, Masanori Yamato, Masayuki Nakano, Satoshi Kume, Yasuhisa Tamura, Yosky Kataoka, Alan Wong, Yusuke Nishiyama
Nuclear magnetic resonance (NMR) spectroscopy is a powerful analytical technique and has been widely used in metabolomics. However, the intrinsic low sensitivity of NMR prevents its applications to systems with limited sample availabilities. In this study, a new experimental approach is presented to analyze mass-scarce samples in limited volumes of less than 300 nL with simple handling. The sample is loaded into the glass capillary, and this capillary is then inserted into a Kel-F rotor. The experimental performance of the capillary-inserted rotor (capillary-insert) is investigated on an isotropic solution of sucrose by the use of a high-resolution micro-sized magic angle spinning (HRµMAS) probe...
August 3, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Iddrisu Abdallah, Elizabeth Armstrong-Mensah, Ernest Alema-Mensah, Cheryl Jones
OBJECTIVES: Demographic and risky sexual behaviours may increase the risk for Trichomonas vaginalis (TV) infection and, thus, enhance HIV transmission to uninfected partners. We assessed the demographic and behavioural risk factors associated with TV among South African HIV-positive men with genital ulcer disease. METHODS: We conducted a cross-sectional study with data from a randomised controlled trial conducted by the Centers for Disease Control and Prevention and the London School of Hygiene and Tropical Medicine...
August 1, 2017: BMJ Open
Taizo Mori, Hirokazu Komatsu, Naoki Sakamoto, Kengo Suzuki, Jonathan P Hill, Mutsuyoshi Matsumoto, Hideki Sakai, Katsuhiko Ariga, Waka Nakanishi
Intramolecular rotation of molecules contained in a two-dimensional monolayer or a three-dimensional collapsed film at an air-water interface was investigated by in situ fluorescence spectroscopy of twisted intramolecular charge transfer (TICT) type 9-(2-carboxy-2-cyanovinyl)julolidine (CCVJ) derivatives. The TICT type molecules, CCVJ-C12 and CCVJ-Chol, that contain a linear alkyl dodecyl chain or a cholesteryl group, respectively, as their hydrophobic group, were designed and synthesized to manipulate them at the air-water interface...
July 31, 2017: Physical Chemistry Chemical Physics: PCCP
Denis Lacabanne, Britta Kunert, Carole Gardiennet, Beat H Meier, Anja Bo Ckmann
Conformational studies of membrane proteins remain a challenge in the field of structural biology, and in particular the investigation of the proteins in a native-like lipid environment. Solid-state NMR presents a valuable opportunity for this, and we present here three critical steps in the solid-state NMR sample preparation, i.e., membrane reconstitution of the protein in native lipids, rotor filling, and sample quality assessment, at the example of the Bacillus subtilis ATP-binding cassette transporter BmrA...
2017: Methods in Molecular Biology
Lucile Senicourt, Luminita Duma, Vassilios Papadopoulos, Jean-Jacques Lacapere
Structural studies of membrane proteins (MP) in a native or native-like environment remain a challenge. X-ray crystallography of three-dimensional crystals of MP in lipids and cryo-electron microscopy of two-dimensional crystals also in lipids have given atomic structures of several MP. Recent developments of solid-state NMR (ssNMR) provided structural data of MP in lipids and should give access to the dynamic behavior of MP's in a native-like environment. Preparation of samples for ssNMR is not trivial with overexpressed proteins since purified recombinant MP have to be reincorporated in proteoliposomes and concentrated in the small volume of the rotor used for ssNMR studies...
2017: Methods in Molecular Biology
Jiao Shi, Ling-Nan Liu, Kun Cai, Qing-Hua Qin
In a short nanobearing system made from carbon nanotubes, the rotor with high rotational frequency may escape from the stator, which may cause a stability problem to the system of a nanodevice with such a nanobearing. In the present work, nanobearings with tri-walled nanotubes are investigated to reveal the conditions for the moving away of the free inner tube from the high-speed rotating middle tube. Experimental results show that the escape happens when the radii difference between the two rotors is larger than 0...
July 28, 2017: Scientific Reports
Ashley A Beckstead, Yuyuan Zhang, Jonathan K Hilmer, Heidi J Smith, Emily Bermel, Christine M Foreman, Bern Kohler
The photophysical properties of the natural pigment violacein extracted from an Antarctic organism adapted to high exposure levels of UV radiation were measured in a combined steady-state and time-resolved spectroscopic study for the first time. In the low-viscosity solvents methanol and acetone, violacein exhibits low fluorescence quantum yields on the order of 10(-4), and femtosecond transient absorption measurements reveal excited-state lifetimes of 3.2 ± 0.2 and 4.5 ± 0.2 picoseconds in methanol and acetone, respectively...
July 28, 2017: Journal of Physical Chemistry. A
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