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Single coil lead

Shaurya Sachdev, Aswin Muralidharan, Pouyan E Boukany
We study the necking and pinch-off dynamics of liquid droplets that contain a semidilute polymer solution of polyacrylamide close to overlap concentration by combining microfluidics and single DNA observation. Polymeric droplets are stretched by passing them through the stagnation point of a T-shaped microfluidic junction. In contrast with the sudden breakup of Newtonian droplets, a stable neck is formed between the separating ends of the droplet which delays the breakup process. Initially, polymeric filaments experience exponential thinning by forming a stable neck with extensional flow within the filament...
December 27, 2016: Macromolecules
Uten Yarach, Myung-Ho In, Itthi Chatnuntawech, Berkin Bilgic, Frank Godenschweger, Hendrik Mattern, Alessandro Sciarra, Oliver Speck
PURPOSE: To describe a model-based reconstruction strategy for single-shot echo planar imaging (EPI) that intrinsically accounts for k-space nonuniformity, Nyquist ghosting, and geometric distortions during rather than before or after image reconstruction. METHODS: Ramp sampling and inhomogeneous B0 field-induced distortion cause the EPI samples to lie on a non-Cartesian grid, thus requiring the nonuniform fast Fourier transform. Additionally, a 2D Nyquist ghost phase correction without the need for extra navigator acquisition is included in the proposed reconstruction...
February 10, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Xing Wang, Sharjeel A Chaudhry, Wensheng Hou, Xiaofeng Jia
Stroke leads to serious long-term disability. Electrical epidural cortical stimulation has made significant improvements in stroke rehabilitation therapy. We developed a preliminary wireless implantable passive interface, which consists of a stimulating surface electrode, receiving coil, and single flexible passive demodulated circuit printed by flexible printed circuit (FPC) technique and output pulse voltage stimulus by inductively coupling an external circuit. The wireless implantable board was implanted in cats' unilateral epidural space for electrical stimulation of the primary visual cortex (V1) while the evoked responses were recorded on the contralateral V1 using a needle electrode...
February 5, 2017: International Journal of Molecular Sciences
Andres Saucedo, Stamatios Lefkimmiatis, Novena Rangwala, Kyunghyun Sung
This paper presents and analyzes an alternative formulation of the locally low-rank (LLR) regularization framework for magnetic resonance image (MRI) reconstruction. Generally, LLR-based MRI reconstruction techniques operate by dividing the underlying image into a collection of matrices formed from image patches. Each of these matrices is assumed to have low rank due to the inherent correlations among the data, whether along the coil, temporal, or multi-contrast dimensions. LLR regularization has been successful for various MRI applications such as parallel imaging and accelerated quantitative parameter mapping...
January 26, 2017: IEEE Transactions on Medical Imaging
Doyong Kim, Nicole Wagner, Kerry Wooding, David E Clemmer, David H Russell
Molecular dynamics (MD) simulations are used to model changes in the conformational preferences of a model peptide during the transition from a hydrated environment (charged nanodroplet generated by electrospray ionization) to the solvent-free peptide ion. The charged droplet consists of ∼2400 water molecules, 22 hydronium ions, and 10 chloride and contains a single Substance P (SP) [SP + 3H](3+) ion (SP(3+); amino acid sequence RPKPQQFFGLM-NH2). Initially, droplet shrinkage involves a combination of solvent evaporation and ejection of excess charge, primarily hydronium ions...
February 13, 2017: Journal of the American Chemical Society
Matthew Bennett, Ratika Parkash, Pablo Nery, Mario Sénéchal, Blandine Mondesert, David Birnie, Laurence D Sterns, Claus Rinne, Derek Exner, François Philippon, Debra Campbell, Jafna Cox, Paul Dorian, Vidal Essebag, Andrew Krahn, Jaimie Manlucu, Franck Molin, Michael Slawnych, Mario Talajic
Sudden cardiac death is a major public health issue in Canada. However, despite the overwhelming evidence to support the use of implantable cardioverter defibrillators (ICDs) in the prevention of cardiac death there remains significant variability in implantation rates across Canada. Since the most recent Canadian Cardiovascular Society position statement on ICD use in Canada in 2005, there has been a plethora of new scientific information to assist physicians in their discussions with patients considered for ICD implantation to prevent sudden cardiac death due to ventricular arrhythmias...
February 2017: Canadian Journal of Cardiology
Junjie Cui, Ji Eon Kwon, Hyeong-Ju Kim, Dong Ryeol Whang, Soo Young Park
We synthesized two different amphiphilic small molecules 1 and 2 by attaching the same oligo(ethylene glycol) (OEG) unit to the same dicyanodistyrylbenzene (DCS) fluorophore but at different positions. These molecules self-assemble into nanoparticles in water and show lower critical solution temperature (LCST) at 26 and 58 °C, respectively. Upon heating, the transition of hydrophilic coils to hydrophobic globules of the OEG unit leads to the change in the stacking structure of the luminescent DCS cores. As a result, it shows significant ratiometric fluorescence color changes from excimeric yellow emission to monomer-dominated green emission...
January 13, 2017: ACS Applied Materials & Interfaces
Daryan Kempe, Michele Cerminara, Simón Poblete, Antonie Schöne, Matteo Gabba, Jörg Fitter
The addition of high amounts of chemical denaturants, salts, viscosity enhancers or macro-molecular crowding agents has an impact on the physical properties of buffer solutions. Among others, the (microscopic) viscosity, the refractive index, the dielectric constant, and the ionic strength can be affected. Here, we systematically evaluate the importance of solvent characteristics with respect to single-molecule FRET (smFRET) data. First, we present a confocal based method for the determination of fluorescence quantum yields to facilitate a fast characterization of smFRET-samples at sub-nM-concentrations...
December 14, 2016: Analytical Chemistry
Cibele Nicolaski Pedron, Marcelo Der Torossian Torres, Julia Aparecida da Silva Lima, Pedro Ismael Silva, Fernanda Dias Silva, Vani Xavier Oliveira
Antimicrobial peptides are biologically active molecules produced by a wide range of organisms as an essential component of the innate immune response. They have recently attracted great interest, since they have antimicrobial activity against a broad spectrum of microorganisms. VmCT1 is a cationic peptide from the venom of Vaejovis mexicanus smithi scorpions, which presents antibacterial activity and tends to helical structures. Its analogs were synthesized, characterized and the conformational studies were performed by circular dichroism...
January 27, 2017: European Journal of Medicinal Chemistry
Patrick Commins, Israel Tilahun Desta, Durga Prasad Karothu, Manas K Panda, Panče Naumov
When exposed to external stimuli such as heat or light, certain single crystals can acquire momentum and undergo motion. On a molecular scale, the motility of such dynamic single crystals is triggered by a phase transition or chemical reaction without gaseous products, and macroscopically manifests as either slow (reversible or irreversible) deformation, or as rapid, almost instantaneous propulsion of the crystals that is oftentimes accompanied by disintegration. While the elastic energy of the slow reconfiguration processes such as bending, twisting and coiling can be utilized for actuation of other objects, the fast disintegrative processes could be exploited to initiate pressure-sensitive applications...
September 29, 2016: Chemical Communications: Chem Comm
Eran Leshem, Mahmoud Suleiman, Avishag Laish-Farkash, Yuval Konstantino, Michael Glikson, Alon Barsheshet, Ilan Goldenberg, Yoav Michowitz
AIMS: Dual-coil leads were traditionally considered standard of care due to lower defibrillation thresholds (DFT). Higher complication rates during extraction with parallel progression in implantable cardioverter defibrillator (ICD) technology raised questions on dual coil necessity. Prior substudies found no significant outcome difference between dual and single coils, although using higher rates of DFT testing then currently practiced. We evaluated the temporal trends in implantation rates of single- vs...
October 4, 2016: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
Youshan Li, Huawei Liu, Rui Zhu, Qingyou Xia, Ping Zhao
Previous studies have indicated that most trypsin inhibitor-like cysteine-rich domain (TIL)-type protease inhibitors, which contain a single TIL domain with ten conserved cysteines, inhibit cathepsin, trypsin, chymotrypsin, or elastase. Our recent findings suggest that Cys(2nd) and Cys(6th) were lost from the TIL domain of the fungal-resistance factors in Bombyx mori, BmSPI38 and BmSPI39, which inhibit microbial proteases and the germination of Beauveria bassiana conidia. To reveal the significance of these two missing cysteines in relation to the structure and function of TIL-type protease inhibitors in B...
December 2016: Peptides
Simon Pecha, Yalin Yildirim, Nils Gosau, Muhammet Ali Aydin, Stephan Willems, Hendrik Treede, Hermann Reichenspurner, Samer Hakmi
OBJECTIVES: Lead extraction in patients with multiple or old leads of an implantable cardioverter defibrillator (ICD) is challenging. As adhesions are common at the side of the shock coils, we investigated success and procedural complication rates of laser lead extraction procedures in single- and dual-coil leads. METHODS: Between January 2001 and June 2013, 41 single- and 145 dual-coil ICD leads were extracted from 171 patients using laser sheaths. Procedural data, success rates and complications were collected into a database and retrospectively analysed...
September 13, 2016: Interactive Cardiovascular and Thoracic Surgery
Anil K Roy, Jonathan A Grossberg, Joshua W Osbun, Susana L Skukalek, Brian M Howard, Faiz U Ahmad, Frank Tong, Jacques E Dion, Charles M Cawley
OBJECTIVE: Carotid cavernous fistula (CCF) development after Pipeline Embolization Device (PED) treatment of cavernous carotid aneurysms (CCA) can be a challenging pathology to treat for the neurointerventionalist. METHODS: A database of all patients whose aneurysms were treated with the PED since its approval by the Food and Drug Administration in 2011 was retrospectively reviewed. Demographic information, aneurysm characteristics, treatment technique, antiplatelet regimen, and follow-up data were collected...
September 5, 2016: Journal of Neurointerventional Surgery
Hideo Okamura, Paul A Friedman, Yuko Inoue, Takashi Noda, Takeshi Aiba, Satoshi Yasuda, Hisao Ogawa, Shiro Kamakura, Kengo Kusano, Raul E Espinosa
BACKGROUND: Single-coil defibrillator leads have gained favor because of their potential ease of extraction. However, a high defibrillation threshold remains a concern in patients with hypertrophic cardiomyopathy (HCM), and in many cases, dual-coil leads have been used for this patient group. There is little data on using single-coil leads for HCM patients. METHODS AND RESULTS: We evaluated 20 patients with HCM who received an implantable cardioverter-defibrillator (ICD) on the left side in combination with a dual-coil lead...
September 23, 2016: Circulation Journal: Official Journal of the Japanese Circulation Society
Chao Zhang, Peiliang Li, Guohua Xi, Joseph J Gemmete, Neeraj Chaudhary, B Gregory Thompson, Aditya S Pandey
PURPOSE: To understand whether the use of antiplatelet agents leads to less intra-aneurismal tissue formation following coil implantation in a rat end-pouch external carotid artery (ECA) aneurysm model. METHODS: End-pouch ECA aneurysms were created in adult rats and were then embedded with either platinum or HydroCoils. Rats were treated either with aspirin, clopidogrel, aspirin + clopidogrel, or saline for 2 weeks after coil implantation. At 2 weeks after coil implantation, rats were sacrificed and the aneurysm pouch was removed for histological and immunohistochemical analysis...
November 2016: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
Kyoko Soejima, Jonathan Edmonson, Michael L Ellingson, Ben Herberg, Craig Wiklund, Jing Zhao
BACKGROUND: Increased magnetic resonance imaging (MRI) adoption and demand are driving the need for device patients to have safe access to MRI. OBJECTIVE: The aim of this study was to address the interactions of MRI with the Micra transcatheter pacemaker system. METHODS: A strategy was developed to evaluate potential MRI risks including device heating, unintended cardiac stimulation, force, torque, vibration, and device malfunction. Assessment of MRI-induced device heating was conducted using a phantom containing gelled saline, and Monte Carlo simulations incorporating these results were conducted to simulate numerous combinations of human body models, position locations in the MRI scanner bore, and a variety of coil designs...
October 2016: Heart Rhythm: the Official Journal of the Heart Rhythm Society
I M L van Kalleveen, H Kroeze, A Sbrizzi, V O Boer, O Reerink, M E P Philippens, C A T van de Berg, P R Luijten, D W J Klomp
PURPOSE: The high precession frequency in ultrahigh field MRI coincides with reduced RF penetration, increased RF power deposition and consequently can lead to reduced scan efficiency. However, the shorter wavelength enables the use of efficient antennas rather than loop coils. In fact, ultrathin monopole antennas have been demonstrated at 7 T, which fit in natural cavities like the rectum in the human body. As the RF field generated by the antenna provides an extremely nonuniform B1 field, the use of conventional RF pulses will lead to severe image distortions and highly nonuniform contrast...
July 2016: Medical Physics
Christopher A Rajkumar, Simon Claridge, Tom Jackson, Jonathan Behar, Jonathan Johnson, Manav Sohal, Sana Amraoui, Arjun Nair, Rebecca Preston, Jaswinder Gill, Ronak Rajani, Christopher Aldo Rinaldi
AIMS: Cardiac perforations caused by pacemaker or implantable cardioverter-defibrillator (ICD) leads are uncommon but potentially fatal events. The optimal approach to such cases is unclear. The aim of this study was to identify the optimal imaging modality and management strategy for cardiac perforation. METHODS AND RESULTS: All patients presenting to a single institution with cardiac perforation >24 h since implant between 2011 and 2015 were identified retrospectively...
June 27, 2016: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
Philip M Chang, Brian D Powell, Paul W Jones, Nathan Carter, David L Hayes, Leslie A Saxon
INTRODUCTION: - Indications for implantable cardioverter defibrillators (ICDs) in young patients have expanded and differ from those in older adults. We sought to provide descriptive characteristics and data regarding ICD therapy and outcomes among younger and older ICD recipients. METHODS AND RESULTS: - Demographics, device type and programming, remotely transmitted data, shock events, and survival were compared among younger (≤30 years) and older (>30 years) cohorts with ICDs from a single manufacturer followed on a remote network...
June 23, 2016: Journal of Cardiovascular Electrophysiology
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