988 resultados para 194-1195


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Targets to cut 2050 CO2 emissions in the steel and aluminium sectors by 50%, whilst demand is expected to double, cannot be met by energy efficiency measures alone, so options that reduce total demand for liquid metal production must also be considered. Such reductions could occur through reduced demand for final goods (for instance by life extension), reduced demand for material use in each product (for instance by lightweight design) or reduced demand for material to make existing products. The last option, improving the yield of manufacturing processes from liquid metal to final product, is attractive in being invisible to the final customer, but has had little attention to date. Accordingly this paper aims to provide an estimate of the potential to make existing products with less liquid metal production. Yield ratios have been measured for five case study products, through a series of detailed factory visits, along each supply chain. The results of these studies, presented on graphs of cumulative energy against yield, demonstrate how the embodied energy in final products may be up to 15 times greater than the energy required to make liquid metal, due to yield losses. A top-down evaluation of the global flows of steel and aluminium showed that 26% of liquid steel and 41% of liquid aluminium produced does not make it into final products, but is diverted as process scrap and recycled. Reducing scrap substitutes production by recycling and could reduce total energy use by 17% and 6% and total CO 2 emissions by 16% and 7% for the steel and aluminium industries respectively, using forming and fabrication energy values from the case studies. The abatement potential of process scrap elimination is similar in magnitude to worldwide implementation of best available standards of energy efficiency and demonstrates how decreasing the recycled content may sometimes result in emission reductions. Evidence from the case studies suggests that whilst most companies are aware of their own yield ratios, few, if any, are fully aware of cumulative losses along their whole supply chain. Addressing yield losses requires this awareness to motivate collaborative approaches to improvement. © 2011 Elsevier B.V. All rights reserved.

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The genotypes of liver mitochondrial high-affinity aldehyde dehydrogenase-2 (ALDH2) are strongly associated with the drinking behavior and the alcohol liver diseases, since the individuals with atypical ALDH(2)(2) allele have higher levels of acetaldehyde in their plasma. The atypical ALDH(2)(2) allele has a nucleotide base transition (G-->A) in its exon 12. Based on this point mutation, we developed a rapid, reliable and inexpensive method, mismatch amplification mutation assay (MAMA), for the determination of human ALDH2 usual and atypical alleles. Two pairs of primers were designed for the amplification of the usual ALDH(2)(1) allele and the atypical ALDH(2)(2) allele, respectively. If the sample for the detection was heterozygous, it could be amplified by both of the primers. The product of polymerase chain reaction (PCR) of ALDH2 exon 12 could be easily screened by electrophoresis on a 2% agarose gel. The results of the MAMA method were further confirmed by sequencing. In the total of fifty samples from unrelated healthy Chinese Han people from Wuhan, China, the frequency of atypical ALDH(2)(2) allele was found to be 12%.

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Xanthohumol, prenylchacone flavonoid, is a natural product with multi-biofunctions purified from Hops Humulus lupulus. Its anti-HIV-1 activity was tested in the present study. Results showed that xanthohumol inhibited HIV-1 induced cytopathic effects, the production of viral p24 antigen and reverse transcriptase in C8166 lymphocytes at non-cytotoxic concentration. The EC50 values were 0.82, 1.28 and 0.50 mug/ml, respectively. The therapeutic index (TI) was about 10.8. Xanthohumol also inhibited HIV-1 replication in PBMC with EC50 value of 20.74 mug/ml. The activity of recombinant HIV-1 reverse transcriptase and the HIV-1 entry were not inhibited by xanthohumol. The results from this study suggested that xanthohumol is effective against HIV-1 and might serve as an interesting lead compound. It may represent a novel chemotherapeutic agent for HIV-1 infection. However, the mechanism of its anti-HIV-1 effect needs to be further clarified. (C) 2004 Elsevier B.V. All rights reserved.

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About 3600 specimens were collected by bottom trawl at 15 sampling stations. 24 biometric characters were measured for each specimens at the laboratory.. Microscopic cross – sections of statolith were used for age determination. Sex determination and fecundity were determined. Population dynamics parameters as well as stock as stock assessment including cohort analysis were estimated using FISAT software. The findings showed that Dorsal Mantle Length (DML) and Body weight (BW) of the Indian squid were 133.9 ± 0.78 mm and 99.61 ± 0.95 g respectively. Strong correlation was found between these 2 variables (R2 = 0.90). The maximum age was 5 years. Relationship between DML and age was highly significantly of p ≤ 0.05. Overall sex ratio (M: F = 0.52) was significantly different from the expected 1:1 ratio (p ≤ 0.05). The ovary weight and nidamental glands weight were 7.72 ± 0.0006 g and 3.07 ± 0.0003g respectively. Absolute and relative fecundity of the Indian squid were found to be 122733 ± 30.87 and 2348 ± 0.4 respectively. GSI were 14.35 in April and 8.63 in July. This squid is therefore a spring spawner. The infinite dorsal mantle length were 258.62 mm for females, 194.72 mm for males and 252.02 for both sexes respectively. For population growth and mortality parameters; K (0.65 per year for both sexes, 0.85 per year for males, 0.65 per year for females); t0 (0.24year for both sexes, 0.22 year in females, 0.26 year in male); φ` (2.30 in both sexes, 2.47 for males, 2.37 for females); Z (1.17 per year for both sexes, 1.10 per year in females, 1.39 per year, in males); M (0.70 per year for both sexes, 0.90 for males, 0.67 for females); F(0.27 per year for both sexes, 0.27 per year in males, 0.195 per year in females). Exploitation coefficient were 0.51 per year for both sexes, 0.57 per year males and 0.51 per year females respectively. The results indicates that since the Indian squid is a short live aquatic organism, therefore, the exploitation coefficient could be raised to 0.7 per year. The analysis showed that total biomass and MSY were 10103.5 ton and 2576.4 ton respectively. These findings are the first study of its sort about the Indian squid in the coastal waters of Oman Sea as well as North-West of Indian Ocean.

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调查表明在云南边境地区实际分布着3种巨蜥, 除V. salvator外, 尚有V. irrawadicus和V. vietnamensis。讨论了这3种巨蜥的有效性, 简要地报道了它们的生境、习性和生存现状, 并就保护问题提出参考意见。

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于1994年至2008年间,对广西河池地区的柳江水系和红水河水系进行了鱼类资源调查.依据实际调查,并结合以往文献记载,这两水系中分布的鱼类共有185种,分别隶属于9目21科107属.较以前调查,新增种类21种,包括1新属19新种.柳江水系分布的鱼类共有134种,分别隶属于8目19科88属.其中,鲤形目鱼类的种类最多,鲈形目鱼类次之,鲇形目鱼类第三,其他目的鱼类种类相对较少,仅1-3种.红水河水系分布的鱼类共有157种,分别隶属于8目20科101属.其中,鲤形目鱼类的种类最多,鲇形目鱼类次之,鲈形目鱼类第三.其他目的鱼类种类相对较少.红水河水系的鱼类多样性较柳江水系丰富,其主要原因为红水河流经区域喀斯特地貌发育,地下河流众多而且流域面积广,水量充沛.

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目的 了解N-甲基-D-天冬氨酸(NMDA)受体NR1亚单位基因与精神分裂症的连锁关系.方法 选取NR1亚单位基因所在区域的2个微卫星标记D9s1838和D9s1826,对94个符合美国精神障碍诊断与统计手册第4版精神分裂症诊断标准(DSM-Ⅳ)的中国汉族精神分裂症受累同胞对及家系成员共376个个体作基因分型,其中男性194名,女性182名.采用美国国立精神卫生研究所(NIMH)制订的《遗传研究诊断问卷》(DIGS),对家系成员躯体和精神状况进行评定;采用NIMH制订的《遗传研究家族问卷》(FIGS)了解家系结构.选用GENEHUNTER 2.1软件对分型资料进行非参数连锁分析.结果 两点、多点非参数分析最大LOD值均位于D9s1826,分别为1.70(P=0.050),2.08(P=0.015),两者均大于验证性连锁阈值1.2.结论 NR1基因区域微卫星标记与精神分裂症存在验证性连锁关系,提示NR1基因可能为精神分裂症的易感基因之一.

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基于外部形态特征和内部骨骼特征对鲤科鲤属中鲤亚属进行了分支系统学分析。内群包括中鲤亚属的全部5种和鲤亚属的2种鱼类,外群采用乌原鲤。在鲤属鱼类和外群间共有48个性状存在变化。系统发育分析采用PAUP~(*)软件的Parsimony和Bootstrap两种方式的Branch-and-Bound算法。排除不能极化的特征和特有离征之后,还有28个特征可用,由这28个特征可得到唯一的系统树,树长69,一致性系数0.7246,排除无用特征的一致性系数0.6122,保留系数0.6346。由5种中鲤组成的中鲤亚属明显不构成一个单系群。结果表明:中鲤亚属是一个复系群,该类元应该被撤销。

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目的 探讨从眼镜蛇毒分离纯化出的神经生长因子(nerve grow th facto r, N GF) 对成年猫坐骨神经 损伤后的影响。方法 制成成年猫坐骨神经损伤模型, 损伤局部注射蛇毒N GF 2 Lgö(kg·d) , 分别治疗10 d 和30 d, 并与对照组(损伤坐骨神经, 不给药物) 比较。结果 术后10 d, 对照组术侧远端神经纤维数量比治疗组明显减少 (P < 0. 01) , 治疗组术侧足底刺激出现早, 肢体活动恢复快。术后30 d, 治疗组术侧远端神经纤维大量再生, 再生神 经纤维数量已明显超过对照组和术后10 d 组水平(P < 0. 01) , 但结构紊乱, 轴突和郎氏结消失。术侧肢体在连续注 射N GF 16 d 左右出现足底刺激反应消失, 肢体瘫痪等改变。结论 眼镜蛇毒N GF 在神经损伤早期应用能减轻神 经纤维发生的溃变, 促进受损神经的再生与功能恢复; 而损伤局部长时间注射蛇毒N GF 则会导致神经纤维增生过 度, 丧失传导功能。