589 research outputs found
Improving Success Rates of Percutaneous Coronary Intervention for Chronic Total Occlusion at a Rural Hospital in East Taiwan
SummaryBackgroundWe aimed to report the results of percutaneous coronary intervention for chronic total occlusion (CTO) in a remote hospital of southeast Taiwan that does not have on-site coronary artery bypass graft support and has insufficient medical resources.MethodsFrom 2006 to 2009, we identified 96 patients who underwent percutaneous coronary intervention and whose coronary angiogram showed CTO lesions. On-site cardiovascular surgeons were unavailable from 2006 to 2009.ResultsThe success rate (test for trend, p = 0.02) and numbers of guidewires used (test for trend, p = 0.59) significantly increased from 2006 to 2009, and the procedural time reduced significantly (test for trend, p = 0.001). The volume of contrast media injected decreased, although this result was not statistically significant (p = 0.70).ConclusionOur experience in managing CTO lesions substantially improved and the procedural time reduced over 4 years, even when constrained by a relative shortage of medical resources
IMECE2002-33382 SCREAM FOR MULTI-LEVEL MOVABLE STRUCTURES BY INDUCTIVELY COUPLED PLASMA PROCESS
ABSTRACT A novel fabrication process to etch, to passivate, and to release single-crystal silicon structures totally in just only one process by inductively coupled plasma reactive ion etching (ICP-RIE) has been presented in this paper. Several kinds of movable actuators such as relay, comb-drive, and capacitance with thickness of 30 m have been fabricated successfully to demonstrate this fabrication process. Here, experimental investigations about fabrication parameters to get well profile and suspension structures are performed in a STS ICP-RIE system
A Low Power Fully Integrated Analog Baseband Circuit with Variable Bandwidth for 802.11 a/b/g WLAN
Abstract: This paper presents experimental results of an analog baseband circuit with variable bandwidth for WLAN direct conversion receiver in UMC 0.18um CMOS process. A seventh order chebyshev lowpass filter with triple bandwidth is used in the analog baseband circuit. The bandwidth is selectable from 7.56MHz, 19.5MHz, or 26.5MHz. The circuit adopts the servo loop for dc offset cancellation. It also has a gain range from 20dB to 60 dB with 10 dB steps while only dissipating 22.248mW. In addition, an automatic frequency tuning loop (ATL) is reported to achieve the bandwidth accuracy of the filter
) The Influence of Low-powered Family LED Lighting on Eyes in Mice Experimental Model
Abstract: Ocular tissue damage because of exposure to visible light has been demonstrated by the results of human and animal studies. The short-wavelength visible light between 430 nm to 500 nm (blue light) is especially associated with retina damage. Recently, new powerful sources and relatively inexpensive blue energy of LED (light emitting diodes) family lamps in home illumination are available. The aim of this study is to investigate the effects of illumination source from the low-powered and the conscious spectrum source of LED family lamps on retina tissues. The illumination source of LED family lamps was analyzed from 300 nm to 800 nm using an UVvisible spectrophotometer. In animal experiments, young adult mice were assigned to expose to family LED light for 2h every day ranging 2 to 4 weeks or light environment using LED family lamps for 39 weeks. After LED light treatment, sections of eyes were stained with hematoxylin and examined using histopathology. The data clearly demonstrated irradiation of the white LED is above 400 nm and is not within the ultraviolet light region. However, the analysis of spectrum distribution demonstrated that the family LED lighting exhibited power-peak at 450 nm is within the blue light region. Histological results showed that the photoreceptor layer is significantly reduced in thickness after 4 weeks of LED exposure 2h every day or LED illuminated environment. This study provides important data regarding the efficacy and safety of LED light in family illumination. It is impossible to consider these degenerative changes are related unavoidably part of their mechanism of action or an avoidable toxic effect
Real-Time Observation of Iodide Ion Migration in Methylammonium Lead Halide Perovskites
Organic-inorganic metal-halide perovskites (e.g. CH3NH3PbI3-xClx) emerged as a promising opto-electronic material. However, the Shockley–Queisser Limit for the power conversion efficiency (PCE) of perovskite-based photovoltaic devices has still not been reached, which was attributed to non-radiative recombination pathways, as suggested by photoluminescence (PL) inactive (or dark) areas on perovskite films. Although these observations have been related to the presence of ions/defects, the underlying fundamental physics and detailed microscopic processes, concerning trap/defect status, ion migration, etc., still remain poorly understood. Here we utilize correlated wide-field PL microscopy and impedance spectroscopy (IS) on perovskite films to in-situ investigate both the spatial and temporal evolution of these PL inactive areas under external electrical fields. We attribute the formation of PL inactive domains to the migration and accumulation of iodine ions under external fields. Hence we are able to characterize the kinetic processes and determine the drift velocities of these ions. In addition, we show that I2 vapor directly affects the PL quenching of a perovskite film, which provides evidence that the migration/segregation of iodide ions plays an important role in the PL quenching and consequently limits the PCE of organometal halide based perovskite photovoltaic devices
Hepatoprotective and Antioxidant Effects of Licorice Extract against CCl4-Induced Oxidative Damage in Rats
Licorice has been used in Chinese folk medicine for the treatment of various disorders. Licorice has the biological capabilities of detoxication, antioxidation, and antiinfection. In this study, we evaluated the antihepatotoxic effect of licorice aqueous extract (LE) on the carbon tetrachloride (CCl4)-induced liver injury in a rat model. Hepatic damage, as reveled by histology and the increased activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) activities, and decreased levels of serum total protein (TP), albumin (Alb) and globulin (G) were induced in rats by an administration of CCl4 at 3 mL/kg b.w. (1:1 in groundnut oil). Licorice extract significantly inhibited the elevated AST, ALP and ALT activities and the decreased TP, Alb and G levels caused by CCl4 intoxication. It also enhanced liver super oxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), Glutathione S-transferase (GST) activities and glutathione (GSH) level, reduced malondialdehyde (MDA) level. Licorice extract still markedly reverses the increased liver hydroxyproline and serum TNF-α levels induced by CCl4 intoxication. The data of this study support a chemopreventive potential of licorice extract against liver oxidative injury
Preparation of a Porous Composite Film for the Fabrication of a Hydrogen Peroxide Sensor
A series of dopant-type polyaniline-polyacrylic acid composite (PAn-PAA) films with porous structures were prepared and developed for an enzyme-free hydrogen peroxide (H2O2) sensor. The composite films were highly electroactive in a neutral environment as compared to polyaniline (PAn). In addition, the carboxyl group of the PAA was found to react with H2O2 to form peroxy acid groups, and the peroxy acid could further oxidize the imine structure of PAn to form N-oxides. The N-oxides reverted to their original form via electrochemical reduction and increased the reduction current. Based on this result, PAn-PAA was used to modify a gold electrode (PAn-PAA/Au) as a working electrode for the non-enzymatic detection of H2O2. The characteristics of the proposed sensors could be tuned by the PAA/PAn molar ratio. Blending PAA with PAn enhanced the surface area, electrocatalytic activity, and conductivity of these sensors. Under optimal conditions, the linear concentration range of the H2O2 sensor was 0.04 to 12 mM with a sensitivity of 417.5 μA/mM-cm2. This enzyme-free H2O2 sensor also exhibited a rapid response time, excellent stability, and high selectivity
- …