Effect of cathodic arc plasma treatment on the properties of WC–Co based hard metals

In this study, ion bombardment in a cathodic arc physical vapor deposition system was applied on WC–Co hard metal surfaces aiming to benefit from the diffusion acceleration effect, and to investigate the role of this effect on the surface composition, morphology and corrosion resistance of the materials. Chromium ions obtained via cathodic arc evaporation were accelerated under low (− 150 V) and high (− 1000 V) bias voltages in order to apply coating–bombardment cycles to sample surfaces. Substrate temperatures were measured by an optical pyrometer during the processes. The treated samples were characterized by scanning electron microscopy (SEM) and X-ray diffractometry (XRD). Temperature measurements showed that the sample temperature could be controlled precisely by adjusting the bias voltage. Temperatures in the range of 750–1200 °C were measured during the treatment depending on the duration of the high bias voltage cycles. XRD analysis showed η phase formation in the near surface regions of all treated samples. The amount of the formed η phase was shown to be dependent on the heating–cooling regime that varied with the applied mode of bias. The corrosion behavior of the samples was investigated by immersing treated and untreated samples in a solution of 5% H₃PO₄ containing 1 g/l Zn^{+ 2} for 24 h at 50 °C. The samples were investigated via SEM observations after immersion. Cathodic arc plasma treated samples showed a better resistance to corrosion in this environment.     

电话交换的发展前景

本文分析了时分复用和包分复用模式各自的应用和优缺点，指出了ＰＤＭ这种不同的通信模式的出现，将对ＴＤＭ技术构成激烈的竞争。同时，无线电话技术的发展及其独特的优势，将使之成为新的接入媒体，它将和Ｉｎｔｅｒｎｅｔ，ＡＴＭ技术一起，对下一代电话交换机的设计产生直接影响。     

Increase of empty pool-activated Ca2+ influx using an intracellular Ca2+ chelating agent

We demonstrate here that stimulated 45Ca2+ influx in A7r5 vascular smooth muscle cells induced either by receptor activation with [Arg]8 vasopressin or by the SR-Ca(2+)-ATPase inhibitor thapsigargin was increased more than threefold if cells were preloaded with the intracellular calcium chelator BAPTA (1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid). The increased influx is probably due to an attenuation of negative feedback of Ca2+ on its own entry accompanied by increased Ca2+ storage capacity of BAPTA-loaded cells leading to diminished cellular Ca2+ release. We propose that BAPTA preloading could be a useful approach to investigate receptor-induced Ca2+ influx.     

RollingStream OSS及NMS实现IPTV运营级管理平台

网络电视（IPTV）是目前业界最热门的话题,作为数字电视的多元化表现形式,IPTV也肩负着对传统电视收看方式的变革推动.本文以哈尔滨IPTV商用业务的市场发展情况作为引导,突出说明一个稳定的、可商用IPTV平台需要有强大的系统运营支撑平台及网络管理平台的支持,同时表明RollingStream IPTV商用系统的可维护性及可管理性.     

Determination of melamine in milk and dairy products by high performance liquid chromatography

A simple, precise, accurate, and validated reverse-phase HPLC method was developed for the determination of melamine in milk (pasteurized and UHT milk) and dairy products (powdered infant formula, fruit yogurt, soft cheese, and milk powder). Following extraction with acetonitrile:water (50:50, vol/vol), samples were purified by filter (0.45 μm), separated on a Nucleosil C8 column (4.6 mm × 250 mm, 3 μm) with acetonitrile:10 mmol/L sodium L-octane sulfonate (pH 3.1; 15:85, vol/vol) as mobile phase at a flow rate of 1 mL/min, and determined by a photodiode array detector. A linear calibration curve was obtained in the concentration range from 0.05 to 5 mg/kg. Milk and dairy products were fortified with melamine at 4 levels producing average recovery yields of 95 to 109%. The limits of detection and quantification of melamine were 35 to 110 and 105 to 340 μg/kg, respectively. The method was then used to analyze 300 samples of milk and dairy products purchased from major retailers in Turkey. Melamine was not found in infant formulas and pasteurized UHT milk, whereas 2% of cheese, 8% of milk powder, and 44% of yogurt samples contained melamine at the 121, 694±146, and 294±98 μg/kg levels, respectively. These findings were below the limits set by the Codex Alimentarius Commission and European Union legislation. This is the first study to confirm the existence of melamine in milk and dairy products in Turkey. Consumption of foods containing these low levels of melamine does not constitute a health risk for consumers.     

Diagnostic value of procalcitonin: the influence of cardiopulmonary bypass, aprotinin, SIRS, and sepsis

We report the perinatal findings in a male fetus with congenital megacystis and anorectal malformations. A 17-year-old primipara was referred to our department at 13 weeks of gestation for management of a 4.6 x 3.8 cm massive intra-abdominal fetal mass consistent with megacystis. The fetal thorax was severely compressed. We used a 22-gauge needle to perform intrauterine fetal vesicocentesis, removing 30 ml of fetal urine, decreasing the fetal bladder diameter/crown-rump length ratio from 65.7 to 17%. Cytogenetic analysis revealed a 46, XY karyotype. Intermittent bladder aspiration was performed weekly from 13 to 20 weeks of gestation and every 2-3 weeks from 21 to 35 weeks of gestation for the purpose of decompression. Mild dilation of both renal pelves was noted beginning at 20 weeks of gestation, however, neither progression of hydronephrosis nor development of oligohydramnios was noted. At 36 weeks of gestation, a live male neonate was delivered with a normal phallus, duodenal atresia, mild congenital heart defects, a distended bladder, bilateral hydronephrosis, megaureters, imperforate anus with rectovesical fistula, cryptorchidism and bilateral vesicoureteric reflux. The postnatal renal function was normal. He underwent serial operations including colostomy, anoplasty with repair of rectovesical fistula, duodeno-duodenostomy, bilateral re-implantation of ureters, orchiopexy and reduction cystoplasty. At 20 months of age, the child had normal renal function. The intravenous pyelogram showed normal functional kidneys, moderate megaureters and moderate megacystis. He underwent clean intermittent catheterization for residual urine. The recurrent urinary tract infections were under control.     

Activators of the nuclear receptor PPARgamma enhance colon polyp formation

A high-fat diet increases the risk of colon, breast and prostate cancer. The molecular mechanism by which dietary lipids promote tumorigenesis is unknown. Their effects may be mediated at least in part by the peroxisome proliferator-activated receptors (PPARs). These ligand-activated nuclear receptors modulate gene expression in response to fatty acids, lipid-derived metabolites and antidiabetic drugs. To explore the role of the PPARs in diet-induced carcinogenesis, we treated mice predisposed to intestinal neoplasia with a synthetic PPARgamma ligand. Reflecting the pattern of expression of PPARgamma in the gastrointestinal tract, treated mice developed a considerably greater number of polyps in the colon but not in the small intestine, indicating that PPARgamma activation may provide a molecular link between a high-fat diet and increased risk of colorectal cancer.     

Integration of Kano's Model Into QFD for Multiple Product Design

Simultaneous multiple product design is essential to meet customer expectations faster and with a focus on shortening life cycles, and new methodologies are needed to address the complexities related to it. quality function deployment (QFD) can help gather customer needs and link them to product design. However, understanding customer needs accurately is a challenge for traditional QFD analysis, and for this reason, Kano's model of customer satisfaction is associated with QFD in the literature. However, incorporating the results of Kano's model into QFD presents another challenge. The objective of this research is to provide a step-by-step methodology that fine-tunes the QFD method by combining Kano's model and QFD in a robust manner, from the perspective of simultaneous multiple product design. This research also includes an application of this proposed methodology on cockpit weather information system (CWIS) design, a part of NASA's Aviation Weather Information (AWIN) project, to demonstrate its usefulness     

Ceroid/lipofuscin formation in cultured human fibroblasts: the role of oxidative stress and lysosomal proteolysis

The mechanisms involved in the accumulation of ceroid/lipofuscin within non-dividing cells are not totally understood. Oxidative stress, as well as diminished activity of lysosomal proteolytic enzymes, are known to induce ceroid/lipofuscin accumulation in a variety of cell types. In order to clarify the roles of oxidative stress and lysosomal proteolysis in ceroidogenesis/lipofuscinogenesis, and to study the fate of already formed ceroid/lipofuscin, confluent cultures of AG-1518 human fibroblasts were exposed to oxidative stress (40% ambient oxygen) and/or treated with the thiol protease inhibitor leupeptin for 2 weeks. Both oxidative stress and protease inhibition caused accumulation of ceroid/lipofuscin per se (estimated by fluorescent, confocal and electron microscopy). The combined effect of these factors was, however, almost three times as large as the sum of their isolated effects. The pigment accumulated progressively as long as the oxidative stress and/or protease inhibition acted; was not eliminated after re-establishment of normal conditions; and decreased in amount after subsequent passage. The results suggest that (i) ceroid/lipofuscin forms within secondary lysosomes due to peroxidative damage of autophagocytosed material, and (ii) it is not substantially eliminated from non-dividing cells by degradation or exocytosis.     

河流生态流量特征图及生态流量评价方法

以水电站大坝下游河道为研究对象,从分析天然日流量特征出发,基于月中值流量和月内典型特征流量绘制了河流生态流量特征图,作为水库下泄生态流量的确定依据。基于此河流生态流量特征图,建立了判断生态流量满足程度的7 d流量偏差率、7 d生态需水保证率、月均生态需水适宜度及基于此3个指标的生态需水综合指标,并给出了各指标的评价依据和评价方法。结果表明,河流生态流量特征图符合各时段河流天然流量的基本特征,可作为指导水库生态泄流的依据;所建立的生态流量评价方法能够反映实际下泄流量与天然流量的变化程度,可用于评价河流的生态流量满足程度。