Influence of labour on epidermal growth factor receptor distribution of the human chorion at term gestation

Ten patients with biopsy verified chronic hepatitis C virus (HCV) infection were treated with oral ribavirin at a dose of 1,000-1,200 mg per day in two divided doses for 12 weeks. Serum alanine aminotransferase (ALT) levels and hepatitis C viral ribonucleic acid (RNA) levels in serum were followed prior to, during, and 12 weeks posttreatment. ALT levels decreased significantly in all patients during therapy from a mean level of 3.21 mukat/l (range 1.22 to 7.79) before, to 1.25 mukat/l (range 0.78 to 2.04) at the end of treatment (P < 0.005). Hereafter, relapse to pretreatment levels was seen within 12 weeks after treatment stop. The hepatitis C viral RNA levels decreased from a mean 10 log titer of 4.1 (range 1-6) before treatment to 3.4 (range 1-5) at treatment stop. Five patients did not change their HCV RNA titers during treatment. Twelve weeks posttreatment only 3 patients had lower titers than prior to treatment. We conclude that oral ribavirin seems to reduce the viral load, at least temporarily, in some patients with chronic viremic HCV infection. Further studies are needed to evaluate fully the effect of oral ribavirin on chronic HCV infection.     

FINITE ELEMENT ELASTIC-PLASTIC-CREEP AND CYCLIC LIFE ANALYSIS OF A COWL LIP

Results are presented of elastic, elastic-plastic and elastic-plastic-creep analyses of an actively cooled cowl lip. A cowl lip is part of the leading edge of an engine inlet of proposed hypersonic aircraft and is subject to severe thermal loadings and gradients during flight. Values of stresses calculated by elastic analysis are well above the yield strength of the cowl lip material. Such values are highly unrealistic, and thus elastic stress analyses are inappropriate. The inelastic (elastic-plastic and elastic-plastic-creep) analyses produce more reasonable and acceptable stress and strain distributions in the component. Finally, using the results from these analyses, predictions are made for the cyclic crack initiation life of a cowl lip. A comparison of predicted cyclic lives shows the cyclic life prediction from the elastic-plastic-creep analysis to be the lowest and, hence, most realistic.     

Low surface energy films based on partially fluorinated isocyanates: the effects of curing temperature

Self-stratification strategy can be used to prepare films in which both bulk and surface properties can be optimized. By using this approach, only a very small quantity of fluorinated species is needed to generate a surface with low surface energy. When cross-linking is involved during film formation, we are dealing with a competition behavior between the diffusion of fluorinated species and the formation of cross-linked network. In this study low surface energy polymeric films were prepared on the basis of partially fluorinated polyisocyanates, in combination with hydroxyl-end-capped three-armed solventless liquid oligoesters and modified hyperbranched polyesters. At a fluorine concentration of only 0.5 wt.%, contact angles of water and hexadecane can reach 120° and 80°, respectively. A surface energy as low as 10–15 mN/m can be obtained upon the addition of less than 1 wt.% of fluorine in the films. It was shown, from real time ATR-FTIR and contact angle measurements, that the curing temperatures demonstrated significant effects on the cross-linking rate as well as on the wettability of the films.     

Subcellular Localisation of a Quinoline-Containing Fluorescent Cyclometallated IrIII Complex in Plasmodium falciparum

A fluorescent analogue of a previously synthesised N,N-chelated Ir^III complex was prepared by coordination of the organic ligand to an extrinsic bis(2-phenylpyridine)iridium(III) fluorophore. This cyclometallated Ir^III complex in itself displays good, micromolar activity against the chloroquine-sensitive NF54 strain of Plasmodium falciparum. Live-cell confocal microscopy found negligible localisation of the fluorescent complex within the digestive vacuole of the parasite. This eliminated the haem detoxification pathway as a potential mechanism of action. Similarly, no localisation of the complex within the parasitic nucleus was found, thus suggesting that this complex probably does not interfere with the DNA replication process. A substantial saturation of fluorescence from the complex was found near phospholipid structures such as the plasma and nuclear membranes but not in neutral lipid bodies. This indicates that an association with these membranes, or organelles such as the endoplasmic reticulum or branched mitochondrion, could be essential to the efficacies of these types of antimalarial compounds.     

Proof planning with multiple strategies

Proof planning is a technique for theorem proving which replaces the ultra-efficient but blind search of classical theorem proving systems by an informed knowledge-based planning process that employs mathematical knowledge at a human-oriented level of abstraction. Standard proof planning uses methods as operators and control rules to find an abstract proof plan which can be expanded (using tactics) down to the level of the underlying logic calculus.In this paper, we propose more flexible refinements and a modification of the proof planner with an additional strategic level of control above the previous proof planning control. This strategic control guides the cooperation of the problem solving strategies by meta-reasoning.We present a general framework for proof planning with multiple strategies and describe its implementation in the Multi system. The benefits are illustrated by several large case studies, which significantly push the limits of what can be achieved by a machine today.     

Optimization of correlated multi-response quality engineering by the upside-down normal loss function

Most of the published literature on robust design is basically concerned with a single response. However, the reality is that common industrial problems usually involve several quality characteristics, which are often correlated. Traditional approaches to multidimensional quality do not offer much information on how much better or worse a process is when finding optimal settings. Köksoy and Fan [Engineering Optimization 44 (8): 935–945] pointed out that the upside-down normal loss function provides a more reasonable risk assessment to the losses of being off-target in product engineering research. However, they only consider the single-response case. This article generalizes their idea to more than one response under possible correlations and co-movement effects of responses on the process loss. The response surface methodology has been adapted, estimating the expected multivariate upside-down normal loss function of a multidimensional system to find the optimal control factor settings of a given problem. The procedure and its merits are illustrated through an example.     

The effect of atmospheric plasma treatment of recycled carbon fiber at different plasma powers on recycled carbon fiber and its polypropylene composites

To increase the mechanical properties of recycled carbon fiber-reinforced polypropylene (PP) composites, recycled carbon fibers (RCF) were subjected to atmospheric plasma treatment at different plasma powers (100, 200, and 300 W). The changes on surface topography and roughness of RCF were examined by atomic force microscopy. Plasma treatment of RCF increased the roughness value of RCF. The variation of surface elemental compositions and tensile strength of RCF were determined by using X-ray photoelectron spectroscopy and tensile test, respectively. Plasma-treated RCF-reinforced PP composites were fabricated using high speed thermo-kinetic mixer. Plasma treatment of RCF at 100 W increased the tensile and flexural strength values of RCF-reinforced PP composites considerably by 17 and 11%, respectively. However, plasma treatment of RCF at higher plasma powers (200 W and 300 W) decreased tensile and flexural strength values of composites because of the etching of RCF. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47131.     

The effect of pyridine ring functionalization on the conductivity of crosslinked CO-poly(styrene-4-vinylpyridine) derivatives

The effect of pyridine ring functionalization in crosslinked co-poly(styrene-4-vinylpyridine) on electrochemical behavior was studied using impedance spectroscopy. The introduction of a substituent on the nitrogen atom increases conductivity from 10^-14 to around 10^-11 Scm^-1 at room temperature, but the effect of the substituent becomes more evident at 64°C, at which the n-butyl derivative (co-poly[styrene-[4-vinyl(N-butylpyridinium bromide)]])-(3) has a higher conductivity (ω = 7 × 10⁻¹⁰ Scm⁻¹) than the hydrogen analog (co-poly[styrene-[4-vinyl(pyridinium bromide)]])-(2) (ω = 4.3 × 10⁻¹⁰ Scm⁻¹), while the iodo derivative (co-poly[styrene-[4-vinyl(N-iodopyridinium bromide)]])-(6) has a conductivity ten times lower. Further increase in the conductivity was observed upon the substitution of the bromine anion with the three-bromide anion (Br₃)⁻, but the effect depends on the substituent on the nitrogen atom: 4.4 times higher conductivity was found for the hydrogen pyridinium salt (4) in comparison with sample (2), and the conductivity increases 30-fold for the N-butyl derivative (5) compared with sample (3). The conductivity increased exponentially with temperature and the activation energy values vary from 0.76 to 1.01 eV. Impedance responses for dried samples of pyridinium salts (2), (3), (4), (5), and (6) suggested electron-type conductivity. The conductivity of crosslinked polymers depends very much on the conditions, and increases by several orders of magnitude when water or methanol is present in the atmosphere during measurement. The conductivity also depends on the structure of the substituent attached to the nitrogen atom: ω = 5 × 10⁻⁴ Scm⁻¹ and ω = 2 × 10⁻⁴ Scm⁻¹ for hydrogen bromide (2) and N-butyl bromide derivative (3), but the conductivity of the N-iodo derivative (6) changed very little. In contrast, the impedance responses for samples stored in the presence of water or methanol suggested ion conductivity. © 1996 John Wiley & Sons, Inc.     

采用水基前驱溶液喷墨印刷制备光催化活性TiO2薄膜

摘译 近年来,作为一种高能量带隙半导体,二氧化钛(TiO2)由于在紫外光照射下具有良好的光催化活性,已引起科研人员的广泛关注.由于TiO2无色透明,具有广泛的应用前景,如薄的TiO2涂层可用于创建自清洁、防雾、超亲水表面.同时,也能用于太阳能电池等光电子行业. 化学溶液沉积法因具有相对简单的大面积生产工艺,且较低的制膜成本和高可用性,成为TiO2薄膜制备常用的方法之一.针对另一种TiO2制备方法,即溶胶凝胶法,大量研究文献主要关注乙醇的水解控制.然而,工业需求鼓励开发水基前驱设计.其难度在于钛醇盐与水的高反应性.在有机介质中,加入少量的水往往导致水解.因此,需要采用络合剂作为稳定剂,阻止纯水中的水解反应和避免由此产生的产物沉淀.     

A laboratory evaluation of partial synthetic automatic transmission fluids

Blending synthetic fluids with conventional base stocks gave large reductions in low temperature viscosity without appreciable reductions in high temperature viscosity or deterioration in properties such as volatility or flash point. Ten percent blends of a polyalpbaolefin or an ester synthetic reduced the viscosity at — 27.9°C by approximately 50%. These blends gave improved oxidation stability as measured by the Aluminum Beaker Oxidation Test, but poorer antiwear performance as measured by the Four Ball Test. The latter result indicated that the antiwear additive package should be optimised to accommodate composition differences between conventional fluids and conventional/synthetic blends.