Energy Cooperation between BRICS Countries(Ⅱ)

The economic rise of the BRICS countries(Brazil, Russia, India, China and South Africa) is closely tied to global energy politics and their increased consumption of global energy. Energy cooperation is one of the main forces behind the development of BRICS. Looking forward, energy concerns will undoubtedly remain an important influencing force for the BRICS, shaping their domestic politics and international relations. The pursuit of oil and gas(China, India, and South Africa) to support economic development and the search for stable petroleum markets(Brazil and Russia) have shaped BRICS relations with other countries and regions. This article is trying to elaborate on the reasons why BRICS Energy cooperation is beneficial for its members; also, this article regards the main challenges hindering cooperation, analyzes BRICS energy cooperation through the use of SWOT analysis and muses potential strategic points for BRICS countries up until 2050.     

Performance of standards: intercomparison, treatment of correlations, detection of laboratory offsets and outliers, and long-term assessment of an ensemble of standards

This paper discusses some techniques for judging the performance of artefact standards. In order of increasing time scales, these are: a cross-comparison design, a means of removing reference-induced correlations, detection of laboratory offsets by travelling standards and a graphical means of assessment in the long term.     

Electrochemical Synthesis of Chromium Silicides from Molten Salts

Electrochemical synthesis of chromium silicides from NaCl-KCl-K2SiF6-CrF3 system has been investigated by cyclic voltammetry and DC （direct current） electrolysis at 850℃. The process of Cr and Si joint electroreduction in chloride-fluoride melt proceeds in one stage in a kinetic mode. The cathode product was analyzed using XRD （X-ray diffraction） method. XRD data have confirmed that CraSi is the dominant phase. SEM （scanning electron microscopy） results have shown that Cr3Si powder samples consist of 50-150 lain particles and that tungsten silicide was formed at the surface of tungsten cathode after chrome-free system electrolysis.     

Pediatric AIDS prognosis using somatic growth velocity

OBJECTIVE: To describe the natural history of somatic growth in HIV infection by constructing age-specific growth velocity norms and to assess specific prognostic information available using these norms. DESIGN: Observations on 1338 HIV-infected children aged 3 months to 15 years who participated in one of four US clinical trials of pediatric anti-HIV therapies were pooled; baseline growth velocity data were obtained using the first 6 months of observation for each child. METHODS: Distributions of physical growth velocities in HIV-infected children in the Pediatric AIDS Clinical Trials Group were computed. Statistical smoothing of growth histories was employed to derive velocity estimates, and quantile regression analysis of growth velocities was performed to allow comparisons of growth rates in age- and gender-heterogeneous cohorts in the context of HIV infection. The quantile regressions provide corrected z-scores for growth velocity that appropriately compare HIV-infected children with one another for the purpose of distinguishing more from less favorable prognoses. RESULTS: Consistent deficits in growth velocity amongst HIV-infected children were revealed when compared with the Fels Institute velocity standards. Approximately 33% of height (and 20% of weight) age- and sex-corrected velocity measurements obtained in the first 6 months of clinical trial participation lay beneath the corresponding third percentiles of the Fels reference distributions, which are commonly regarded as critical indicators of growth failure. Proportional hazards regression tests indicated that both weight and height velocity contributed significant information on the risk of death among children with AIDS after adjusting for antiretroviral therapy received, CD4 cell counts, and age at trial enrollment. Comparing subjects who differ in initial weight velocity by one age- and sex-corrected SD, the relative hazard of death was 0.63 (95% confidence interval, 0.55-0.72; P < or = 0.0001) in favor of the child with greater weight velocity, controlling for antiretroviral therapy received, age and CD4 cell count at baseline. The analogous hazard ratio for height velocity was 0.68 (95% confidence interval, 0.57-0.79; P < or = 0.0001). CONCLUSIONS: Suitably normalized growth velocities are informative and inexpensive criteria for pediatric AIDS prognosis; the growth velocity distributions presented will be useful for comparing growth effects of new therapeutic strategies to those of single and combination antiretrovirals employed for maintenance of pediatric HIV infection in the mid-1990s.     

Characterization of the mRNA encoding a proline-rich 37-kilodalton glycoprotein from the excretory-secretory products of Trichostrongylus colubriformis

A glycoprotein, with apparent molecular weight in SDS-polyacrylamide gels of 37 kDa, has been isolated from the excretory-secretory (ES) products of the adult stage of Trichostrongylus colubriformis, a parasitic nematode. This protein is the major ES product recognized in immunoblots by lymph from a naturally infected sheep. A synthetic oligonucleotide, based on peptide sequence data from a digest of the purified protein was used to successfully screen a cDNA library. A cDNA clone was isolated which encoded a presumptive protein precursor of 220 amino acids that contained a 63 amino acid region of which more than 35% of the residues were proline, three peptide sequences determined from the natural component, and three potential N-glycosylation sites, consistent with the protein being isolated from the lectin-bound fraction of the adult ES products. The presumptive, processed, amino terminus encoded by the cDNA clone was preceded by a signal-like, hydrophobic-rich region of 16 amino acids.     

Does hormone replacement therapy inhibit coronary artery calcification?

OBJECTIVE: To determine the association between the use of hormone replacement therapy (HRT) and coronary calcium, in postmenopausal women who had no history of coronary artery disease by double helical computed tomography (CT). METHODS: We used CT to compare the prevalence and extent of coronary calcium in 41 postmenopausal women who were on HRT from the first year of menopause and 37 age-matched controls who had never used HRT. RESULTS: Both groups had a similar rate of smoking, hypertension, a positive family history, and hypercholesterolemia. Coronary calcification was observed in 28.2% of the 78 women studied. The prevalence of coronary calcium was significantly lower among HRT users: six of the 47 (14.6%), compared with 16 of the 37 nonusers (43.2%) (P < .01). The recorded risk factors had no effect on the prevalence of coronary calcium. Stepwise logistic regression analysis, including age, coronary risk factors, and HRT use as independent variables, yielded HRT as the only variable determining the presence of coronary calcium (odds ratio = 0.2; 95% confidence interval 0.06, 0.63; P = .006). CONCLUSION: The lower incidence of coronary calcium in the HRT users suggests that HRT is associated with decreased prevalence of the coronary calcification.     

Outside-in signaling in the chondrocyte. Nitric oxide disrupts fibronectin-induced assembly of a subplasmalemmal actin/rho A/focal adhesion kinase signaling complex

Elevated levels of fibronectin (Fn) in articular cartilage have been linked to the progression of both rheumatoid and osteoarthritis. In this study, we examined intracellular events which follow ligation of Fn to its receptor, the integrin alpha5beta1. In addition, we examined the regulatory influence of nitric oxide on these events, since this free radical has been implicated in cartilage degradation. Exposure of chondrocytes to Fn-coated beads resulted in the circumferential clustering of the alpha5beta1 integrin receptor, which was accompanied by the subplasmalemmal assembly of a focal activation complex comprised of F-actin, the tyrosine kinase, focal adhesion kinase (FAK), the ras related G protein rho A, as well as tyrosine-phosphorylated proteins. Treatment with exogenous nitric oxide (NO) or catabolic cytokines which induce nitric oxide synthase blocked the assembly of F-actin, FAK, rho A and tyrosine-phosphorylated proteins while not affecting the total number of beads bound per cell nor the clustering of alpha5beta1 integrin. Use of a cGMP antagonist (Rp-8-Br cGMPS) or cGMP agonist (Sp-cGMPS) either abolished or mimicked the NO effect, respectively. Adherence of chondrocytes to fibronectin enhanced proteoglycan synthesis by twofold (vs. albumin). In addition, basic fibroblast growth factor (FGF) and insulin growth factor (IGF-1) induced proteoglycan synthesis in chondrocytes adherent to Fn but not albumin suggesting a costimulatory signal transduced by alpha5betal and the FGF receptor. Both constitutive and FGF stimulated proteoglycan synthesis were completely inhibited by nitric oxide. These data indicate that the ligation of alpha5beta1 in the chondrocyte induced the intracellular assembly of an activation complex comprised of the cytoplasmic tail of alpha5beta1 integrin, actin, and the signaling molecules rho A and FAK. We show that NO inhibits the assembly of the intracellular activation complex and the synthesis of proteoglycans, but has no effect on the extracellular aggregation of alpha5beta1 integrin. These observations provide a basis by which nitric oxide can interfere with chondrocyte functions by affecting chondrocyte-matrix interactions.