首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   12篇
  免费   1篇
  2018年   2篇
  2017年   2篇
  2009年   1篇
  1999年   2篇
  1998年   1篇
  1994年   1篇
  1992年   1篇
  1984年   1篇
  1983年   2篇
排序方式: 共有13条查询结果,搜索用时 234 毫秒
1.
Conclusion  In conclusion, LCA that is conducted and used appropriately is an indispensable tool to assist decision-makers in making an informed decision about the environmental impacts of their activities, products or services. A global effort towards LCA use should be encouraged and countries in the Asian/Pacific Regions should not be left out. LCA-related activities reported in the symposium were described  相似文献   
2.
The persistence of hepatitis B surface antigen (HBsAg) is a risk factor for the development of steatosis-associated tumors in chronic hepatitis B virus (HBV) infection, yet little is known about the metabolic link with this factor. We correlated HBV-related pathogenesis in genetically engineered mice and human carriers with metabolic proteomics and lipogenic gene expression profiles. The immunohistochemistry showed that the promyelocytic leukemia protein (PML, a tumor suppressor involved in genome maintenance and fatty acid oxidation), being inversely influenced by the dynamic HBsAg levels from acute phase to seroclearance, appeared as a lipo-metabolic switch linking HBsAg-induced steatosis (lipogenesis) to HBsAg-lost fat-burning hepatocarcinogenesis (lipolysis). Knockdown of PML in HBsAg-transgenic mice predisposed to obesity and drove early steatosis-specific liver tumorigenesis. Proteome analysis revealed that the signaling pathways corresponding to energy metabolism and its regulators were frequently altered by suppression or depletion of PML in the HBsAg-transgenic mice, mainly including oxidative phosphorylation and fatty acid metabolism. Expression profiling further identified upregulation of stearoyl-CoA desaturase 1 (Scd1) and epigenetic methylation of NDUFA13 in the mitochondrial respiratory chain and the cell cycle inhibitor CDKN1c in concordance to the increased severity of lipodystrophy and neoplasia in the livers of HBsAg-transgenic mice with PML insufficiency. The defect in lipolysis in PML-deficient HBsAg-transgenic mice made the HBsAg-induced adipose-like liver tumors vulnerable to synthetic lethality from toxic saturated fat accumulation with a Scd1 inhibitor. Our findings provide mechanistic insights into the evolution of steatosis-associated hepatic tumors driven by reciprocal interactions of HBsAg and PML, and a potential utility of lipid metabolic reprogramming as a treatment target.  相似文献   
3.
Fifteen steroids including corticosteroids, androgens, progestins, and their derivatives were completely separated by reverse-phase high-pressure liquid chromatography on a ChemcoPak 7 ODS-H column in 50 min. The elution procedures were first with water:methanol:acetonitrile:isopropanol 55:32:6.5:7.5 (v/v) for 15 min and followed with a linear gradient elution for 35 min from 0 to 80% of water:methanol:n-butanol 40:40:20 (v/v). The applicability of this method was successfully demonstrated in the analyses of the biological samples of carp plasma, testis, and head kidney.  相似文献   
4.
Transgenic rice plants have been regenerated from kanamycin-resistant callus of Oryza sativa (cv. Taipei 309) derived from protoplasts electroporated with pCaMVNEO carrying the neomycin phosphotransferase II ( nptII ) gene. Of 6 randomly selected plants, all contained the nptll gene, but only 2 plants expressed NPTII activity. The transgenic plants were significantly shorter, produced fewer tillers, took longer to flower and had reduced fertility compared to non-transformed protoplastderived plants. Fifty-six seeds collected from one transgenic plant expressing NPTII activity germinated on medium containing kanamycin sulphate to give 16 green, first seed generation (R1) plants. The latter could be divided into 3 groups: (i) Plants which set seed, had normal floret morphology and produced a total of 76 seeds; (ii) Plants which flowered, but which failed to set seed; (iii) Plants which failed to flower, were shorter and had significantly fewer tillers than plants of groups (i) and (ii). The nptII gene was present in all transgenic R1 plants, but only 8 plants expressed the gene. Phenotypic characteristics, observed in transgenic R1 plants were also seen in the transforned R2 plants. These included reduced stature, a longer vegetative phase and reduced fertility compared to non-transformed plants.  相似文献   
5.
The prevalence of Enterobius vermicularis infection among preschool children was reported to be low based on a 5-year screening program in Taipei City, Taiwan. The Taipei City government intended to terminate the E. vermicularis screening program among preschool children. Thus, we were entrusted with confirming whether pinworm infections among preschool children in Taipei City had truly declined. From each of 12 administrative districts 2-3 kindergartens were randomly selected for investigation. In total, 4,349 children were examined, of which 2,537 were boys and 1,812 were girls. The cellophane tape adhered to a glass slide was used, and all examinations were done by certified medical technologists. Results indicated that the overall prevalence rate of pinworm infections was 0.62% (27/4,349). Although the infection rate was higher among boys (0.67%, 17/2,537) than in girls (0.55%, 10/1,812), no significant difference was found (χ2 = 0.399, P = 0.62). According to the administrative district, the infection rate ranged from no positive cases of E. vermicularis infection in the Xinyi, Zhongzhen, and Wanhua Districts (0%; 0/299, 0/165, and 0/358, respectively), to 0.26% (1/131) in Songshan District, with the highest rate of 1.88% (7/373) in Wenshan District. Because the overall infection rate (0.62%, 27/4,349) in the present study was unchanged compared to that (0.40%, 197/49,541) previously reported in 2005, we propose that regular pinworm screening and treatment programs should be continued in some parts of Taipei City.  相似文献   
6.
Rice protoplasts were cultured using 4 different culture procedures such as agarose embedding (AE) without feeder cells and the use of filter membranes (MEM), one layer of nylon mesh (MS1), or a double layer of nylon mesh (MS2) with the inclusion of Lolium multiflorum as feeder cells. The protoplast plating efficiency was highest on the MEM, followed by MS2, MS1 and AE. However, plant regeneration frequencies were highest for MS1, followed by MS2, MEM and AE. The protoclonal plants differed in the morphology of leaves, flowers, spikelets, and panicles in comparison to seed-derived plants. They varied in almost every phenotypic characters evaluated. In many cases, the variation was significantly different in characteristics such as plant height, flag leaf length and width and ratio, and in panicle characteristics such as panicle length, number of primary branches, and number of spikelets per panicle. The number of seeds per panicle was greatly reduced in protoclonal plants when compared with seed-derived control plants. The seeds showed also significant differences in grain length and width in comparison to the control plants. Among the 4 groups of protoclonal plants derived from the 4 different culturing procedures themselves, there were also variations in almost all the phenotypic characteristics assessed. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
7.
【目的】并蛎蚧属盾蚧科并蛎蚧属,该虫食性杂,危害植物种类多,极易随水果、苗木、景观花卉植物等寄主传播入境。并蛎蚧分布于美国、日本和我国台湾省,在我国大陆地区尚未见该虫的发生报道。2016年5月山西口岸从来自台北的水果释迦上截获了并蛎蚧,为我国大陆首次截获。【方法】通过显微形态特征的观察和测量进行种类鉴定,并研究并蛎蚧的生物学、生态学相关资料,对其进行风险评估。【结果】并蛎蚧与近似种的主要区别:中臀叶与第二臀叶愈合中间有腺刺,有第三对臀叶,中臀叶有向内延伸的硬化区。通过风险评估认为,来自我国台湾、日本的并蛎蚧入侵我国大陆的风险较大。并蛎蚧在大陆亚热带地区的定殖和扩散风险很大。【结论】我国大陆地区的气候条件、植物种类可为并蛎蚧的定殖提供可能的适生条件,各口岸应对进境的并蛎蚧寄主植物加强检验检疫。  相似文献   
8.
Clausine-D inhibited concentration-dependently the aggregation and release of washed rabbit platelets induced by arachidonic acid and collagen, without affecting those induced by U46619, PAF and thrombin. The IC50 values of clausine-D on arachidonic acid-and collagen-induced platelet aggregation were calculated to be 9.0±1.1 and 58.9±0.9 μM, respectively. Thromboxane B2 and prostaglandin D2 formation in platelets caused by arachidonic acid were also suppressed. Clausine-D inhibited increased intracellular concentration of calcium in platelets caused by arachidonic acid and collagen, and also abolished the generation of inositol monophosphate caused by arachidonic acid, but not that by collagen U46619, PAF and thrombin. In human citrated platelet-rich plasma, clausine-D inhibited the secondary phase, but not the primary phase, of aggregation induced by epinephrine and ADP. These results indicate that the antiplatelet effect of clausine-D is due to inhibition of the formation of thromboxane A2.  相似文献   
9.
Peripheral T-cell subsets in 77 patients with hepatitis B surface antigen (HBsAg)-positive chronic liver diseases were studied by indirect immunofluorescence using murine monoclonal antibodies against all peripheral T cells (OKT3), T-helper/inducer cells (OKT4), and T-cytoxic/suppressor cells (OKT8). OKT4/OKT8 ratios were significantly reduced in patients with hepatitis B e antigen (HBeAg)-positive chronic liver diseases, including 28 patients with chronic active hepatitis (CAH) (P less than 0.001) and 15 with chronic persistent hepatitis (CPH) (P less than 0.001). OKT4/OKT8 ratios were significantly lower in 21 HBeAg-negative patients with CAH (P less than 0.05), as compared to those of 17 normal controls, while T-cell subsets in 13 patients with HBeAg-negative CPH were essentially normal. Low OKT4/OKT8 ratios significantly correlated with HBeAg positivity (P less than 0.001) and CAH (P less than 0.05), as assessed with multiple regression. There was a significant negative correlation between OKT4/OKT8 ratios and serum glutamic-pyruvic transaminase (SGPT) levels (r = -0.37; P less than 0.01). It was concluded that in chronic hepatitis B virus infection, low OKT4/OKT8 ratios are closely related to active viral replication and more severe histological and biochemical activity.  相似文献   
10.
In this study, the genetic diversity and identification of Bradyrhizobium symbionts of Crotalaria zanzibarica, the most widely-distributed invasive legume in Taiwan, and other sympatric legume species growing along riverbanks of Taiwan were evaluated for the first time. In total, 59 and 54 Bradyrhizobium isolates were obtained from C. zanzibarica and its coexisting legume species, respectively. Based on the multilocus sequence analysis (MLSA) of concatenated four housekeeping genes (dnaK-glnII-recA-rpoB gene sequences, 1901 bp), the 113 isolates displayed 53 unique haplotypes and grouped into 21 clades. Of these clades, 11 were found to be congruent to already defined Bradyrhizobium species, while the other 10 clades were found to not be congruent to any defined species. In particular, the C. zanzibarica isolates belong to 14 MLSA clades, six of which overlapped with the isolates of coexisting legumes. According to the nodA gene sequences (555 bp) obtained from the 105 isolates, these isolates were classified into three known nodA clades, III.2, III.3 and VII and were further clustered into 10 groups. Furthermore, the C. zanzibarica isolates were clustered into 8 nodA groups, five of which overlapped with the isolates from coexisting legumes. Additionally, the nodA genes of the isolates from native species were dominated by Asian origin, while those from C. zanzibarica were dominated by American origin. In conclusion, C. zanzibarica is a promiscuous host capable of recruiting diverse Bradyrhizobium symbionts, some of which are phylogenetically similar to the symbionts of coexisting legumes in Taiwan.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号