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   3820篇
  免费   4篇
电工技术   1篇
综合类   2篇
化学工业   12篇
轻工业   5篇
无线电   1篇
一般工业技术   7篇
冶金工业   3790篇
自动化技术   6篇
  2021年   1篇
  2019年   1篇
  2017年   2篇
  2016年   1篇
  2014年   1篇
  2011年   1篇
  2010年   1篇
  2007年   2篇
  2006年   5篇
  2004年   1篇
  2003年   5篇
  2001年   1篇
  2000年   1篇
  1999年   134篇
  1998年   1210篇
  1997年   666篇
  1996年   415篇
  1995年   216篇
  1994年   180篇
  1993年   243篇
  1992年   23篇
  1991年   46篇
  1990年   46篇
  1989年   60篇
  1988年   62篇
  1987年   52篇
  1986年   34篇
  1985年   35篇
  1983年   8篇
  1982年   17篇
  1981年   21篇
  1980年   20篇
  1979年   2篇
  1978年   8篇
  1977年   96篇
  1976年   196篇
  1975年   9篇
  1974年   1篇
  1955年   1篇
排序方式: 共有3824条查询结果,搜索用时 15 毫秒
81.
Medical and neuropsychiatric sequelae of HIV infection present a spectrum of diagnostic and treatment challenges to mental health clinicians. Both HIV and the many opportunistic infections that manifest in patients due to their immunocompromised state also can affect the central nervous system (CNS). Thus, mental health clinicians need to be familiar with the diagnosis and management of HIV-related medical and psychiatric complications. This article provides an overview of the CNS-related manifestations resulting from HIV disease, including HIV-related dementia, psychotic disorders, delirium, CNS opportunistic infections and tumors, systemic abnormalities, psychoactive substances, and the adverse effects of certain medical treatments. Treatment strategies for individuals with HIV disease and comorbid severe mental illness are outlined and recommendations for future research are offered.  相似文献   
82.
BACKGROUND: Transcatheter arterial chemoembolization (TACE) has been contra-indicated for the treatment of patients with hepatocellular carcinoma (HCC) and main portal vein (MPV) obstruction because of the potential risk of hepatic insufficiency resulting from ischemia after TACE. The current controlled study was undertaken to assess the safety, efficacy, and predictive factors of favorable response to TACE in patients with HCC and MPV obstruction with good hepatic function and adequate collateral circulation around the MPV. METHODS: Of a total of 47 patients, 31 were treated with TACE, and 16 who declined the procedures were untreated controls. Thirty-six patients (77%) had diffuse-type HCC and 11 (23%) had nodular-type HCC. During the first week after TACE immediate postprocedural complications were evaluated, and the development of hepatic insufficiency as a late complication was assessed at the end of the fourth week. The cumulative survival rate was estimated by the Kaplan-Meier method, and predictors of better prognosis were obtained by univariate and multivariate analyses. RESULTS: Although no patients showed clinical evidence of hepatic insufficiency as an immediate complication, transient fever and abdominal pain were common. Progressive hepatic insufficiency developed at the fourth week; however, there was no difference between the treated and untreated groups. The survival time of treated patients was statistically no longer than that of untreated patients. In the univariate analysis, tumor type and size, the pattern of iodized oil uptake in the tumor, and the presence of iodized oil uptake in the tumor thrombi at the MPV significantly influenced the prognosis. Tumor type, whether treated or not, was the most important prognostic factor patients with nodular-type HCC had significantly longer survival time (median, 11 months) than those with diffuse-type HCC (median, 4 months). Regarding the efficacy of TACE, there was no statistical difference in survival between treated and untreated diffuse-type HCC patients. In comparison, with nodular-type HCC it seemed that survival time was longer for TACE-treated patients (median, 30 months) than for untreated patients (median, 7 months). CONCLUSIONS: TACE may be a safe modality for the treatment of patients with HCC and MPV obstruction, provided that the patients have good hepatic function and collateral circulation around the MPV. However, TACE was not efficacious in the treatment of diffuse-type HCC. The authors recommend TACE for treating nodular-type HCC because of the potential benefit of prolonged survival.  相似文献   
83.
84.
85.
86.
87.
We have previously demonstrated that IFN-gamma causes cell growth inhibition and up-regulation of MHC antigens in human renal cell carcinoma cell lines. In this study, we have investigated the therapeutic potential of IFN-gamma for the treatment of 5-day established pulmonary metastases induced by i.v. injection of Renca cells, a murine renal adenocarcinoma. We found that systemic injections of IFN-gamma significantly reduced the number of lung metastases in a dose-dependent manner and increased mouse survival. Histological evaluation of IFN-gamma-treated lungs showed residual small tumor nodules containing extensive necrosis and mononuclear infiltrates. Immunohistochemistry studies on lung sections showed macrophage infiltration into tumor nodules, and in vivo depletion of macrophages partially inhibited IFN-gamma antitumor effect, suggesting a role for the macrophages in tumor destruction. Lymphocyte depletion of either natural killer (NK) cells or CD4+ or CD8+ T-cell subsets or both T-cell subsets did not affect the IFN-gamma effect, whereas depletion of both NK and T cells decreased the antitumor activity of IFN-gamma. These data indicate that neither T cells nor NK cells are essential for this activity but that either lymphocyte population can contribute to the IFN-gamma effect. An optimal dose of IFN-gamma inhibited by 60% the growth of Renca cells treated for 3 days in vitro, but this effect was transient and less pronounced in a long-term colony assay, suggesting that IFN-gamma direct growth inhibition may play a role but may not be sufficient to mediate its antitumor effect in vivo. In vitro, IFN-gamma caused up-regulation of class I MHC antigens and induction of class II antigen expression in Renca cells, an effect that may enhance Renca immunogenicity but may be relevant only when a T-cell response is elicited. A sequential administration of IFN-gamma followed by interleukin 4 was therapeutically better than IFN-gamma alone for the treatment of advanced pulmonary metastases, probably due to different antitumor mechanisms induced by these two cytokines.  相似文献   
88.
89.
90.
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