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   141篇
  免费   10篇
  2023年   1篇
  2021年   2篇
  2019年   5篇
  2018年   3篇
  2017年   2篇
  2016年   1篇
  2015年   4篇
  2014年   3篇
  2013年   5篇
  2012年   4篇
  2011年   1篇
  2010年   3篇
  2009年   6篇
  2008年   17篇
  2007年   8篇
  2006年   11篇
  2005年   11篇
  2004年   8篇
  2003年   8篇
  2002年   4篇
  2001年   4篇
  2000年   6篇
  1999年   4篇
  1998年   3篇
  1997年   2篇
  1996年   4篇
  1995年   1篇
  1994年   2篇
  1993年   2篇
  1989年   3篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1985年   2篇
  1984年   2篇
  1983年   1篇
  1982年   1篇
  1981年   4篇
排序方式: 共有151条查询结果,搜索用时 22 毫秒
61.

Background

Candidia esophagitis (CE) is an AIDS-defining condition, usually occurring in individuals with low CD4 counts of <200 cells/µL. Endoscopy is a valuable definitive diagnostic method for CE but may not be indicated for asymptomatic patients or for those with high CD4 counts or without oral candidiasis. This study assessed such patients to clarify the factors associated with CE and its severity on endoscopy in the highly active antiretroviral therapy (HAART) era.

Methodology/ Principal Findings

A total of 733 HIV-infected patients who underwent upper gastrointestinal (GI) endoscopy were analyzed. Sexual behavior, CD4+ count, HIV-RNA viral load (VL), history of HAART, GI symptoms, GI diseases, and oral candidiasis were assessed. Endoscopic severity of CE was classified as mild (Kodsi''s grade I/II) or severe (grade III/IV). Of the 733 subjects, 62 (8.46%) were diagnosed with CE (mild, n = 33; severe, n = 29). Of them, 56.5% (35/62) had no GI symptoms, 30.6% (19/62) had CD4 + ≥200 cells/μL, and 55.3% (21/38) had no oral candidiasis. Univariate analysis found lower CD4+ counts, higher HIV VL, and no history of HAART to be significantly associated with CE. With lower CD4+ counts and higher HIV VL, CE occurrence increased significantly (P<0.01 for trend in odds). Multivariate analysis showed low CD4+ counts and high HIV VL to be independently associated with CE. Of the severe CE patients, 55.2% (16/29) had no GI symptoms and 44.4% (8/18) had no oral candidiasis. Median CD4+ counts in severe cases were significantly lower than in mild cases (27 vs. 80; P = 0.04).

Conclusions

Low CD4+ counts and high HIV VL were found to be factors associated with CE, and advanced immunosuppression was associated with the development of severity. Endoscopy is useful as it can detect CE, even severe CE, in patients without GI symptoms, those with high CD4 counts, and those without oral candidiasis.  相似文献   
62.

Background

The diagnosis of gastrointestinal (GI) involvement in Kaposi''s sarcoma (KS) is important to make because the need for treatment depends on the extent of the disease. Moreover, severe GI lesions can cause serious complications. Endoscopy with biopsy is an extremely useful method to diagnose GI-KS. However, determining the indications for endoscopy is difficult because KS can occur without GI symptoms or cutaneous KS. This study sought to clarify predictive clinical factors for GI-KS and its severity on endoscopy.

Methodology/Principal Findings

A total of 1,027 HIV-infected patients who underwent endoscopy were analyzed. Sexual behavior, CD4 count, HIV RNA, history of highly active antiretroviral therapy (HAART), GI symptoms, and cutaneous KS were assessed. Endoscopic severity including bulky tumor, ulceration, and number of lesions were evaluated. Thirty-three patients had GI-KS and 46 patients cutaneous KS. Among the GI-KS patients, 78.8% (26/33) had no GI symptoms and 24.2% (8/33) had no cutaneous KS. Univariate analysis identified men who have sex with men (MSM), CD4 <100 cells/µL, HIV RNA ≥10,000 copies/mL, no history of HAART, and cutaneous KS were significantly associated with GI-KS. Among these factors, cutaneous KS was closely related to GI-KS on multivariable analysis. Among patients without cutaneous KS, MSM and CD4 count <100 cells/µL were the only independent clinical factors related to GI-KS. Bulky tumor was significantly associated with CD4 <100 cells/µL and large number of lesions was significantly associated with HIV-RNA ≥10,000 copies/mL.

Conclusions

To diagnose GI-KS, clinical factors need to be considered before endoscopy. The presence of GI symptoms is not useful in predicting GI-KS. MSM and CD4 count <100 cells/µL are predictive factors among patients without cutaneous KS. Caution should be exercised especially in patients with low CD4 counts or high HIV viral loads as they are more likely to develop severe GI-KS lesions.  相似文献   
63.
Post-ischemic inflammation is an essential step in the progression of brain ischemia-reperfusion injury. However, the mechanism that activates infiltrating macrophages in the ischemic brain remains to be clarified. Here we demonstrate that peroxiredoxin (Prx) family proteins released extracellularly from necrotic brain cells induce expression of inflammatory cytokines including interleukin-23 in macrophages through activation of Toll-like receptor 2 (TLR2) and TLR4, thereby promoting neural cell death, even though intracellular Prxs have been shown to be neuroprotective. The extracellular release of Prxs in the ischemic core occurred 12 h after stroke onset, and neutralization of extracellular Prxs with antibodies suppressed inflammatory cytokine expression and infarct volume growth. In contrast, high mobility group box 1 (HMGB1), a well-known damage-associated molecular pattern molecule, was released before Prx and had a limited role in post-ischemic macrophage activation. We thus propose that extracellular Prxs are previously unknown danger signals in the ischemic brain and that its blocking agents are potent neuroprotective tools.  相似文献   
64.
Phylogenetic analyses were conducted using complete nucleotide sequences of the D-loop in the mitochondrial genome of Mola specimens, collected mainly in Japanese waters, to clarify the genetic features and distribution patterns of Mola sunfishes. Two significantly distinct groups (designated A and B) were present in the genus, with a considerable net nucleotide sequence divergence between the two (8.4%). The two groups occurred sympatrically around the Japanese coast, as previously suggested by Sagara et al. (2005). Group A occurred mostly on the Pacific coast of eastern Japan, while group B was widely distributed along the Kuroshio Current, strongly suggesting different migration routes for each group. The morphological characteristics of the two group specimens were differentiated via the head bump, body proportions and shape of the clavus. Through the addition of Mola sequence data taken from outside Japan to our phylogenetic analyses, three independent groups, including groups A and B, were found, each with a wide geographical distribution, which suggests the presence of at least three independent species within the genus Mola.  相似文献   
65.
Reduced human β-defensin (hBD)-1, -2, -3 and -4 synthesized by Boc chemistry were subjected to oxidative folding reaction under optimal conditions. Among the factors affecting the oxidative folding in the presence of reduced and oxidized glutathione (GSH/GSSG), the buffer concentration and reaction temperature were essential for the predominant formation of the native disulfide structure. The homogeneity of the four synthetic hBDs was confirmed by analytical procedures using RP-HPLC, IEX-HPLC, capillary zone electrophoresis (CZE) and MALDI-TOF MS as well as sequencing, although high temperature (70 °C) was used for the RP-HPLC analysis of hBD-3 and hBD-4 to exclude the influence of equilibrium with the respective conformers having native disulfide pairing. All synthetic hBDs were shown to possess the native disulfide structure by sequential analyses and mass measurements with cystine segments obtained by enzymatic digestion. Upon digestion of hBD-1 and hBD-4 with proline specific endopeptidase, the Cys-X bond was found to be reproducibly cleaved together with the Pro-X bond although the cleavage of Cys-X afforded the appropriate cystine segments for determining the disulfide structure of hBD-1 and hBD-4. With respect to antimicrobial activity against E. coli, the four synthetic hBDs of high homogeneity possessed the same potencies as those reported previously.Australian Peptide Conference Issue  相似文献   
66.
Tetrahymena p85 is localized to the presumptive division plane before division furrow formation; its molecular weight in SDS-polyacrylamide gel electrophoresis differs in wild-type and temperature-sensitive cell-division-arrest mutant cdaA1 cells. At the restrictive temperature, p85 localization and division furrow formation are not observed in cdaA1 cells. In this study, we purified p85 and cloned a wild-type p85 cDNA. The deduced amino acid sequence of p85 was composed mainly of two kinds of repeat sequences. One of these contained regions homologous to a calmodulin-binding site and a part of actin, and the other contained a region homologous to a part of a cdc2 kinase homologue. Moreover, we cloned a cDNA encoding the cdaA1 p85. There was no difference in the predicted amino acid sequences of wild-type and cdaA1 p85, suggesting that the difference in molecular weight between p85 in wild-type and mutant cells is caused by a disorder of posttranslational-modification mechanisms of p85 in the cdaA1 cell.  相似文献   
67.
Complex vertebral malformation (CVM) is an autosomal recessive inherited defect in the Holstein breed. It causes intra-uterine mortality leading to repeat breeding and involuntary culling of cows. This study was carried out to show the prevalence of CVM carriers among Holstein cows in five dairy farms in Hiroshima Prefecture, South Western Japan and whether the defect could be inherited to crossbred F1 generation, when Japanese Black semen was used to inseminate a Holstein cow. Two hundreds Holstein cows were used in the study. Blood samples were collected from all cows in a heparinized tubes and genomic DNA was extracted with a commercial kit. Apart of the bovine solute carrier family 35 member 3 (SLC35A3) gene around the suspected mutation (G to T) was amplified with an allele specific polymerase chain reaction (AS-PCR). For DNA sequencing, PCR products of 522 bp were obtained from the genomic DNA of the cows. Out of 200 examined cows, 26 cows (13.0%) were found to be CVM carriers. Wild type cows showed amplification with the G-specific primer pair but not with the T-specific primer pair, while carrier ones showed amplification of both the G- and T-specific primers, exhibited two DNA bands of 395 bp. Based on the clinical history of the cows, lowered reproductive performance was noticed in carrier ones. Out of four crossbred F1 calves (Holstein x Japanese Black), two were CVM carrier. Crossbred F1 could inherit the CVM defect when Japanese Black semen used to inseminate a carrier Holstein cow. In conclusion, the study reports the occurrence of CVM among Holstein cows in Hiroshima Prefecture, Japan; moreover, it describes the first cases of CVM in crossbred F1 generation.  相似文献   
68.
C4-Fluorinated analogues of solamin, an antitumor acetogenin, were synthesized and investigated for their antitumor activities against 39 tumor cell lines. C4-Fluorinated solamins showed more potent growth inhibitory activity against cancer cell lines than solamin.  相似文献   
69.
Aims: To investigate the occurrence and distribution of thermo‐acidophilic bacteria (TAB) associated with various commercial fruit crop soils in Japan and to assess their ability to produce the odorous phenolic compound, guaiacol. Methods and Results: Phylogenetic analysis based on the 5′ end of the 16S rRNA gene (approximately 500 bp), was performed on 62 TAB isolated from the soil of several Japanese fruit orchards. The results suggested that 60 of the bacterial strains analysed belonged to the genus Alicyclobacillus, while the remaining two belonged to the genus Bacillus. The majority of strains (58%) were identified as Alicyclobacillus acidoterrestris. This group partitioned into three phylogenetically distinct subgroups (A–C). Isolates identified as A. acidiphilus (two strains), A. acidoterrestris (36 strains), and A. hesperidum subsp. aigle (one strain), produced guaiacol from vanillic acid. Levels of guaiacol production varied significantly among strains. The guaiacol producing phenotype was conserved among certain species, however no correlation was observed between levels of guaiacol production and 16S rRNA gene‐based phylogenetic relatedness. Conclusions: Alicyclobacillus acidoterrestris and Alicyclobacillus contaminans were widely distributed among various fruit orchards in Japan. Guaiacol production was common at the species/subspecies level; however the amount of guaiacol produced by each strain varied significantly. Significance and Impact of the Study: This study provides a comprehensive phylogenetic survey of Alicyclobacillus species in Japanese fruit orchards. Quality control standards for guaiacol producing Alicyclobacillus have also been described.  相似文献   
70.
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