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21.
The electrochemical synthesis of poly(o-anisidine) (POA) was achieved on brass (CuZn) electrode by applying two scan rates (50 and 20 mVs−1). The synthesized polymer films were strongly adherent and homogeneous in both cases. Their corrosion performance was investigated by AC impedance spectroscopy (EIS) technique, anodic polarization plots and open circuit potential-time curves, in 3.5% NaCl solution. It was clearly seen that poly(o-anisidine) films provided a significant physical protection for longer exposure time. It was shown that polymer film coated at high scan rate (CuZn/POA-H) exhibited better barrier property against the attack of corrosive agents when compared with polymer film obtained at low scan rate (CuZn/POA-L). It was found out that poly(o-anisidine) film synthesized at high scan rate caused a significant increase in corrosion resistance by its catalytic behavior on formation of protective oxide layers on the surface in longer time.  相似文献   
22.
In this study, polyvinyl alcohol (PVA) and boric acid (BA) were mixed in an aqueous medium by heating in order to prepare a PVA/BA hybrid material. The viscosity and pH values of the PVA/BA hybrid material mixed in various proportions were determined. Then the hybrid polymer was electrospun to give dimensions to fibers. The FT-IR spectra of these fibers revealed that BA chemically reacted with PVA and formed B–O–C bonds. The fibers were first calcified at 500 °C and then the calcified products were pelleted and exposed to the sintering process at 1300 °C. The XRD peaks of the sintered product were seen at 2θ = 34.7 and 37.7° verified the formation of boron carbide. The study proved that it was possible to use sub-micron fibers for the production of sub-micron boron carbide material.  相似文献   
23.
Organizations are in the process of moving to a network-based operating structure. Telecommuting is just a corollary of this push. While new information technologies allow for a highly mobile work force that can work from remote locations across the world, this begs the question how does supporting this new telecommuting workforce differ from supporting employees in a regular office. The purpose of this study is to describe how telecommuting and a telecommuter differ from in situ working and the desk-bound worker and how this difference dictates different approaches to providing various services such as IT support services for telecommuters. Our goal is to provide a framework to assist IT managers in addressing issues of how to support telecommuting employees to maximize their potential benefits.  相似文献   
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The copolymer films PANI-co-POA and poly(aniline-co-o-anisidine) were carried out on copper (Cu) electrode, by applying two different scan rates (20 and 50 mV s−1) and using two different thicknesses at high scan rate. Synthesizes were achieved under cyclic voltammetric conditions from 0.075 M aniline and 0.075 M o-anisidine containing sodium oxalate solutions. The synthesized copolymer films were strongly adherent and homogeneous in both cases. AC impedance spectroscopy (EIS), anodic polarization plots and open circuit potential–time curves were used to evaluate the corrosion performance of copolymer coated and uncoated electrodes in 3.5% NaCl. It was shown that the copolymer film coated at low scan rate exhibited a better property initially when compared with the copolymer film produced at high scan rate. However, it could not resist the attack of corrosion products, in longer time and meanwhile its barrier property significantly diminished. It was found that the thin copolymer film produced at high scan rate by its catalysing effect led to the formation of highly protective copper oxides on the surface whereby providing a better protection for long exposure times. It also emerged that the corrosion resistances of thin copolymer film produced at high scan rate and copolymer film synthesized at low scan rate were almost same and relatively higher for much longer periods when compared with the one observed for bare copper electrode.  相似文献   
26.
The objective of this paper is to develop a Taguchi optimization method for low surface roughness in terms of process parameters when milling the mold surfaces of 7075-T6 aluminum material. Considering the process parameters of feed, cutting speed, axial-radial depth of cut, and machining tolerance, a series of milling experiments were performed to measure the roughness data. A regression analysis was applied to determine the fitness of data used in the Taguchi optimization method using milling experiments based on a full factorial design. Taguchi orthogonal arrays, signal-to-noise (S/N) ratio, and analysis of variance (ANOVA) are used to find the optimal levels and the effect of the process parameters on surface roughness. A confirmation experiment with the optimal levels of process parameters was carried out in order to demonstrate the effectiveness of the Taguchi method. It can be concluded that Taguchi method is very suitable in solving the surface quality problem of mold surfaces.  相似文献   
27.
Thoracic venous anomalies without congenital heart anomalies are present in minority of the population, but they are frequent enough to be encountered while placing hemodialysis catheters through the jugular or subclavian veins. Persistent left superior vena cava is the most commonly seen anomaly and it is rarely noticed before the observation of an unusual course of hemodialysis catheter or guidewire on chest X‐ray. We present two patients with previously unspotted persistent left superior vena cava and uncomplicated hemodialysis catheter insertions through the internal jugular veins with good catheter functions. Review of the relevant literature from a nephrologists’ perspective with technical aspects is provided.  相似文献   
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Leptospirosis, an endemic zoonotic disease caused by Leptospira, is frequently seen in tropical regions and areas with low socioeconomic status. The disease can present a range of symptoms from mild to fatal, with potential involvement of multiple organs. This case report describes the treatment and clinical course of a 44-year-old male patient infected with Leptospira semeranga patoc 1 and presenting with jaundice and renal failure. The patient was residing in the Syrian Refugee Camp in the arid city of Sanliurfa. This case serves as an example of a nonendemic occurrence of leptospirosis, and a brief overview of relevant literature on the subject is also provided.  相似文献   
30.
Aberrant WNT pathway activation, leading to nuclear accumulation of β-catenin, is a key oncogenic driver event. Mutations in the tumor suppressor gene APC lead to impaired proteasomal degradation of β-catenin and subsequent nuclear translocation. Restoring cellular degradation of β-catenin represents a potential therapeutic strategy. Here, we report the fragment-based discovery of a small molecule binder to β-catenin, including the structural elucidation of the binding mode by X-ray crystallography. The difficulty in drugging β-catenin was confirmed as the primary screening campaigns identified only few and very weak hits. Iterative virtual and NMR screening techniques were required to discover a compound with sufficient potency to be able to obtain an X-ray co-crystal structure. The binding site is located between armadillo repeats two and three, adjacent to the BCL9 and TCF4 binding sites. Genetic studies show that it is unlikely to be useful for the development of protein–protein interaction inhibitors but structural information and established assays provide a solid basis for a prospective optimization towards β-catenin proteolysis targeting chimeras (PROTACs) as alternative modality.  相似文献   
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