Locally Gated SnS/hBN Thin Film Transistors with a Broadband Photoresponse.

Next-generation flexible and transparent electronics demand newer materials with superior characteristics. Tin dichalcogenides, Sn(S,Se), are layered crystal materials that show promise for implementation in flexible electronics and optoelectronics. They have band gap energies that are dependent on their atomic layer number and selenium content.

Enhancement of near-infrared detectability from InGaZnO thin film transistor with MoS light absorbing layer.

We report an enhancement of near-infrared (NIR) detectability from amorphous InGaZnO (α-IGZO) thin film transistor in conjunction with randomly distributed molybdenum disulfide (MoS) flakes. The electrical characteristics of the α-IGZO grown by radio-frequency magnetron sputtering exhibit high effective mobility exceeding 15 cm V s and current on/off ratio up to 10. By taking advantages of the high quality α-IGZO and MoS light absorbing layer, photodetection spectra are able to extend from ultra-violet to NIR range.

Electrical and photovoltaic properties of residue-free MoS thin films by liquid exfoliation method.

Molybdenum disulfide (MoS) film fabricated by a liquid exfoliation method has significant potential for various applications, because of its advantages of mass production and low-temperature processes. In this study, residue-free MoS thin films were formed during the liquid exfoliation process and their electrical properties were characterized with an interdigitated electrode. Then, the MoS film thickness could be controlled by centrifuge condition in the range of 20 ∼ 40 nm, and its carrier concentration and mobility were measured at about 7.

Linearly and Highly Pressure-Sensitive Electronic Skin Based on a Bioinspired Hierarchical Structural Array.

Pressure-sensitive electronic skin composed of a hierarchical structural array exhibits outstanding linear and high sensitivity in the pressure range exerted by gentle touch. By virtue of monolayer graphene acting as electrode material, this device can be operated with low voltage. Especially, its high transparency enables an accurate placement of the device on the target position when it is used for health monitoring.

Thermal annealing effects on ZnO films grown on graphene buffered Si substrates.

ZnO films deposited on SiO2/Si substrate with a graphene single layer (GSL) were studied by using an ultra-high vacuum sputter. The as-prepared films were annealed at temperature ranges from 500 degrees C to 800 degrees C for 1 min under ambient N2 gas. When the annealing temperature was increased up to 800 degrees C, the root mean square roughness of the ZnO/Si sample surface decreased down to 3.

Impact of long term left ventricular assist device therapy on donor allocation in cardiac transplantation.

Background: Left Ventricular Assist Devices (LVAD) are increasingly used as a bridge to transplant (BTT) for patients with advanced congestive heart failure (CHF) and are assigned United Network for Organ Sharing (UNOS) high priority status (1B or 1A).

Methods: The purpose of our study was asses the effect of organ allocation in the era of continuous flow pumps. A retrospective chart review was performed of all patients transplanted between 1/2001-1/2011 at Columbia University Medical Center.

The CentriMag ventricular assist device in acute heart failure refractory to medical management.

Background: The CentriMag ventricular assist device (VAD) has gained popularity in the last several years as rescue support for patients with decompensated heart failure. We have used the CentriMag VAD as a bridge to decision device. We describe our experience with device placement, use and outcomes.

Incidence and predictors of pacemaker placement after surgical ablation for atrial fibrillation.

Background: Bradyarrhythmia requiring pacemaker placement is a relatively common complication after surgical ablation for atrial fibrillation (AF). We report our experience with surgical ablation procedures using various energy modalities and lesion sets in an attempt to identify the risk factors associated with postoperative pacemaker requirement.

Methods: Intraoperative data were collected prospectively, and preoperative and postoperative data were collected retrospectively.

Predictors of mortality after short-term ventricular assist device placement.

Background: Risk assessment prior to long-term ventricular assist device (VAD) placement has been shown to be crucial for successful outcomes and efficient resource utilization. Short-term VADs are often used as salvage therapy in acute heart failure when the clinical scenario precludes such thorough preoperative assessment. Our goal was to devise a risk stratification system that may be used shortly after stabilization of hemodynamics with a short-term VAD to predict the likelihood of survival.

Use of ventricular assist devices in patients with mitral valve prostheses.

Background: Use of ventricular assist devices (VADs) in patients with prosthetic valves may carry an increased risk of thromboembolism; however, clinical information is lacking. The aim of this study was to report our experience of the use of VADs in patients with prosthetic mitral valves.

Methods: A retrospective analysis of 747 VAD patients from January 1995 to May 2010 was performed.

Aortic valve procedures at the time of ventricular assist device placement.

Background: Placement of a ventricular assist device (VAD) may lead to reduced or absent opening of the aortic valve and thus increase risk of thrombus formation in the aortic root as well as on the valve itself. The outcome of additional procedures to the aortic valve at the time of VAD placement is unclear.

Methods: A retrospective analysis of 712 VAD patients from 1995 to 2009 was performed.

Improved diabetic control in advanced heart failure patients treated with left ventricular assist devices.

Aims: Left ventricular assist devices (LVADs) are increasingly used as therapeutic options for patients with advanced congestive heart failure (CHF), many of whom suffer from diabetes mellitus (DM). The aim of this study was to evaluate the effect of restoration of normal cardiac output using LVAD support on diabetes control in patients with advanced CHF.

Methods And Results: A retrospective chart review of all clinic patients supported with long-term LVADs between July 2008 and July 2009 at Columbia University Medical Center was performed.

Prevalence of de novo aortic insufficiency during long-term support with left ventricular assist devices.

Background: Left ventricular assist devices (LVADs) are increasingly used as long-term therapy for end-stage heart failure patients. We compared the prevalence of aortic insufficiency (AI) after HeartMate II (HMII) vs HeartMate XVE (HMI) support and assessed the role of aortic root diameter and aortic valve opening in the development of AI.

Method: Pre-operative and post-operative echocardiograms of 93 HMI and 73 HMII patients who received implants at our center between January 2004 and September 2009 were retrospectively reviewed.

Acquired von Willebrand syndrome after continuous-flow mechanical device support contributes to a high prevalence of bleeding during long-term support and at the time of transplantation.

Objectives: The objective of the study was to determine the prevalence of bleeding during continuous-flow left ventricular assist device support and to identify potential mechanisms for those bleeding events.

Background: Bleeding is frequently reported with continuous-flow left ventricular assist devices and may result from anticoagulation coupled with bleeding diathesis such as acquired von Willebrand syndrome. Accordingly, the prevalence of coagulation abnormalities including laboratory assessment for von Willebrand syndrome, bleeding events during device support, and at heart transplantation were evaluated.

Activation of endogenous GABAA channels on airway smooth muscle potentiates isoproterenol-mediated relaxation.

Reactive airway disease predisposes patients to episodes of acute smooth muscle mediated bronchoconstriction. We have for the first time recently demonstrated the expression and function of endogenous ionotropic GABA(A) channels on airway smooth muscle cells. We questioned whether endogenous GABA(A) channels on airway smooth muscle could augment beta-agonist-mediated relaxation.