In this review, the advances in radio-frequency (RF) /microwave chemical gas sensors using conducting polymers are discussed. First, the introduction of various conducting polymers is described. Only polyaniline (PANi), polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT), which are mainly used for gas sensors in RF/microwave region, are focused in this review.
View Article and Find Full Text PDFThis study aims to investigate the microwave properties of coplanar waveguide (CPW)-based poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) conducting polymer line in an ethanol gas atmosphere, with the frequency range of 0.5-2 GHz. For an ethanol-exposed PEDOT:PSS line (test sample), the transmission coefficient () decreased immediately; moreover, the microwave effective conductivity (σ) decreased simultaneously, compared with the ethanol-free PEDOT:PSS line (reference sample).
View Article and Find Full Text PDFA real-time humidity sensor based on a microwave resonator coupled with a poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) conducting polymer (CP) film is proposed in this paper. The resonator is patterned on a printed circuit board and is excited by electromagnetic field coupling. To enhance the sensitivity of the sensor, the CP film is located in the area with the strongest electric field in the resonator.
View Article and Find Full Text PDFOtolaryngol Head Neck Surg
September 2014
Objective: This study evaluates the relationship between visually identifiable (18)F-fluorodeoxyglucose (FDG) uptake in primary papillary thyroid microcarcinoma (PTMC) and tumor aggressiveness.
Study Design: Historical cohort study.
Setting: Tertiary care center.
The aim of this study is to evaluate the differences between forward-firing and multidirectional lasers and to evaluate the effects of exposure times and power on laser ablation of thyroid tissue. This is an experimental, ex vivo study. The experiments were conducted on 3 thyroid glands using 2 power levels (3 and 5 W) and exposure times (3 and 5 minutes) with forward-firing and multidirectional lasers.
View Article and Find Full Text PDFCarbon nanotubes (CNT) are extremely sensitive to environmental gases. However, detection of mixture gas is still a challenge. Here, we report that 10 ppm of carbon monoxide (CO) and ammonia (NH3) can be electrically detected using a carboxylic acid-functionalized single-walled carbon nanotubes (C-SWCNT).
View Article and Find Full Text PDFThe effect of plasma treatment on the gas sensing properties of screen-printed single-walled carbon nanotube (SWCNT) pastes is reported. The gas sensors, using SWCNT pastes as a sensing material, were fabricated by photolithography and screen printing. The SWCNT pastes were deposited between interdigitated electrodes on heater membrane by screen printing.
View Article and Find Full Text PDFNanoscale Res Lett
November 2011
Noxious gas sensors were fabricated using carbon nanotubes [CNTs] with palladium nanoparticles [Pd NPs]. An increase in the resistance was observed under ammonia for both CNTs and CNT-Pd sensors. Under carbon monoxide [CO], the two sensors exhibited different behaviors: for CNT sensors, their resistance decreased slightly with CO exposure, whereas CNT-Pd sensors showed an increase in resistance.
View Article and Find Full Text PDFSingle-walled carbon nanotube (SWNT) networks were used to detect hazardous dimethyl-methyl-phosphonate (DMMP) gas in real time, employing two different metals as electrodes. Random networks of SWNTs were simply obtained by drop-casting a SWNT-containing solution onto a surface-oxidized Si substrate. Although the electrical responses to DMMP at room temperature were reversible for both metals, the Pd-contacting SWNT network sensors exhibited a higher response and a shorter response time than those of the Au-contacting SWNT network sensors at the same DMMP concentration, due to the stronger interactions between the SWNTs and Pd surface atoms.
View Article and Find Full Text PDFOperative treatment of aneurysm in patients with Behçet's disease frequently results in recurrent aneurysm at the anastomosis site or in the remaining artery. Herein, in a Behçet's patient with aortic and iliac pseudoaneurysms, a ruptured iliac artery stump aneurysm after ligation of the right external iliac artery 1 year prior to this admission is reported. This case suggests that the ligation or interposition of aneurysms associated with Behçet's disease should be done at the intact artery, remote to the diseased segment.
View Article and Find Full Text PDFAcute renal vein thrombosis (RVT) is a rare but noteworthy form of venous thromboembolism. Traditional management has been systemic anticoagulation with heparin, followed by warfarin. We report a case of acute RVT with multiple pulmonary emboli that occurred in a 40-year-old woman who was taking oral contraceptives and was subsequently found to have protein S deficiency.
View Article and Find Full Text PDFRenal transplant recipients requiring aortic reconstruction due to abdominal aortic aneurysm (AAA) pose a unique clinical problem. The concern during surgery is causing ischemic injury to the renal allograft. A variety of strategies for protection of the renal allograft during AAA intervention have been described including a temporary shunt, cold renal perfusion, extracorporeal bypass, general hypothermia, and endovascular stent-grafting.
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