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   807篇
  免费   63篇
  国内免费   3篇
耳鼻咽喉   4篇
儿科学   35篇
妇产科学   46篇
基础医学   99篇
口腔科学   14篇
临床医学   75篇
内科学   179篇
皮肤病学   28篇
神经病学   53篇
特种医学   18篇
外科学   85篇
综合类   8篇
预防医学   101篇
眼科学   6篇
药学   66篇
中国医学   19篇
肿瘤学   37篇
  2023年   13篇
  2022年   7篇
  2021年   43篇
  2020年   30篇
  2019年   43篇
  2018年   38篇
  2017年   33篇
  2016年   40篇
  2015年   36篇
  2014年   48篇
  2013年   49篇
  2012年   68篇
  2011年   53篇
  2010年   45篇
  2009年   23篇
  2008年   48篇
  2007年   44篇
  2006年   40篇
  2005年   38篇
  2004年   30篇
  2003年   23篇
  2002年   19篇
  2001年   7篇
  2000年   7篇
  1999年   3篇
  1997年   6篇
  1996年   2篇
  1993年   1篇
  1992年   5篇
  1991年   4篇
  1990年   7篇
  1989年   2篇
  1988年   6篇
  1987年   2篇
  1986年   2篇
  1985年   3篇
  1984年   1篇
  1983年   3篇
  1981年   1篇
排序方式: 共有873条查询结果,搜索用时 15 毫秒
91.
92.
93.
Human dendritic cells (DC) comprise 2 subsets-plasmacytoid CD123(+) and myeloid CD11c(+) DC-that may have distinct roles in the regulation of immunity after allogeneic hematopoietic stem cell transplantation. In this study, we analyzed the kinetics of CD123(+) DC and CD11c(+) DC reconstitution in 31 patients who underwent transplantation with allogeneic granulocyte colony-stimulating factor-mobilized peripheral blood (PB) stem cells from HLA-identical sibling donors after myeloablative conditioning. Lineage marker-negative HLA-DR(+) CD11c(+) CD11c(+) DC and lineage marker-negative HLA-DR(+) CD123(+) CD123(+) DC, as well as monocytes and lymphoid subsets, were enumerated in donor grafts and in the PB of patients at various time points after transplantation. Reconstitution of both CD11c(+) DC and CD123(+) DC to normal levels occurred within 6 to 12 months and was not affected by the diagnosis, preparatory regimen, or graft composition. However, PB CD11c(+) DC and CD123(+) DC counts were significantly reduced in patients with acute GVHD grade II to IV (at 1 and 3 months) and grade I (at 1 month). Patients with chronic GVHD instead showed reduced CD123(+) DC counts only 6 months after transplantation. Moreover, treatment with steroids (>0.1 mg/kg) was significantly associated with reduced PB CD11c(+) DC and CD123(+) DC counts at all time points after transplantation. In multivariate analysis, only acute GVHD affected DC reconstitution early after transplantation. These results will prompt new studies addressing whether DC reconstitution correlates with immunity against infectious agents or with graft-versus-tumor reactions after PB stem cell allotransplantation.  相似文献   
94.
Colucins A (1) and B (2), new flavonoids and colucone (3), the new chalcone derivative, have been isolated from the CHCl3-soluble fraction of the whole plant of Colutea armata along with luteolin (4), luteolin 7-O-β-D-glucoside (5), isoliquiritigenin (6), trans-caffeic acid (7) and stigmasterol (8) reported for the first time from this species. Their structures were elucidated by spectroscopic techniques including MS and 2D-NMR spectroscopy. Compounds 1 and 2 showed significant antimicrobial activity against two Gram positive and three Gram negative bacterial strains while 3 was moderately active.  相似文献   
95.

Background

We hypothesized that changes in International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) prognostic category at start of second-line therapy (2L) for metastatic renal cell carcinoma (mRCC) might predict response.

Objective

To assess outcomes of 2L according to type of therapy and change in IMDC prognostic category.

Design, setting, and participants

We performed a retrospective review of the IMDC database for mRCC patients who received first-line (1L) VEGF inhibitors (VEGFi) and then 2L with VEGFi or mTOR inhibitors (mTORi). IMDC prognostic categories were defined before each line of therapy (favorable, F; intermediate, I; poor, P). Data were analyzed for 1516 patients, of whom 89% had clear cell histology.

Intervention

All included patients received targeted therapy for mRCC.

Outcome measurements and statistical analysis

Overall survival (OS), time to treatment failure, and response to 2L were analyzed using Cox or logistic regression.

Results and limitations

At start of 2L, 60% of patients remained in the same prognostic category; 9.0% improved (3% I → F; 6% P → I); 31% deteriorated (15% F → I or P; 16% I → P). Patients with the same or better IMDC prognostic category had a longer time to treatment failure if they remained on VEGFi compared to those who switched to mTORi (adjusted hazard ratio [AHR] ranging from 0.33 to 0.78, adjusted p < 0.05). Patients who deteriorated from F to I appeared more likely to benefit from switching to mTORi (median OS 16.5 mo, 95% confidence interval [CI] 12.0–19.0 for VEGFi; 20.2 mo, 95% CI 14.3–26.1 for mTORi; AHR 1.53, 95% CI 1.04–2.24; adjusted p = 0.03).

Conclusions

Changes in IMDC prognostic category predict the subsequent clinical course for patients with mRCC and provide a rational basis for selection of subsequent therapy.

Patient summary

The pattern of treatment failure might help to predict what the next treatment should be for patients with metastatic renal cell carcinoma.  相似文献   
96.
Metabolic syndrome (MS) is a highly prevalent health problem worldwide and is associated with different risk factors, including hyperglycemia, dyslipidemia, hypertension, and obesity. This condition increases the risk of developing type II diabetes mellitus and cardiovascular problems. The MS is one of the most important health concerns in industrialized countries and mainly results from a sedentary lifestyle, high levels of subjective stress, and unhealthy diets. Nowadays, the identification of appropriate health care approaches, such as herbal medicines, with fewer side effects is more favorable, especially with regard to the adverse effects of chemical drugs. Aloe barbadensis Miller known as Aloe vera is a useful plant with two major parts, including leaves that contain high concentrations of anthraquinone compounds and a clear gel. The gel is used as a food with several beneficial properties, such as antiinflammatory, antioxidant, antiviral, antibacterial, and wound‐healing features. Other effects of A. vera, such as its lipid‐lowering, antihypertensive, antidiabetic, antiobesity, and cardioprotective impacts, have been demonstrated in several studies. The present study was conducted to review the evidence on the pharmacological effects of A. vera on the different components of MS.  相似文献   
97.
98.
99.
100.
Curcumin (diferuloylmethane), which has been shown to inhibit growth of transformed cells, has no discernible toxicity and achieves high levels in colonic mucosa. 5-fluorouracil (5-FU) or 5-FU plus oxaliplatin (FOLFOX) remains the backbone of colorectal cancer chemotherapeutics, but with limited success. The present investigation was, therefore, undertaken to examine whether curcumin in combination with conventional chemotherapeutic agent(s)/regimen will be a superior therapeutic strategy for colorectal cancer. Indeed, results of our in vitro studies demonstrated that curcumin together with FOLFOX produced a significantly greater inhibition (p < 0.01) of growth and stimulated apoptosis (p < 0.001) of colon cancer HCT-116 and HT-29 cells than that caused by curcumin, 5-FU, curcumin + 5-FU or FOLFOX. These changes were associated with decreased expression and activation (tyrosine phosphorylation) of EGFR, HER-2, HER-3 (72-100%) and IGF-1R (67%) as well as their downstream effectors such as Akt and cycloxygenase-2 (51-97%). Furthermore, while these agents produced a 2-3-fold increase in the expression of IGF-binding protein-3 (IGFBP-3), curcumin together with FOLFOX caused a 5-fold increase in the same, when compared to controls. This in turn led to increased sequestration of IGF by IGFBP-3 rendering IGF-1 unavailable for binding to and activation of IGF-1R. We conclude that the superior effects of the combination therapy of curcumin and FOLFOX are due to attenuation of EGFRs and IGF-1R signaling pathways. We also suggest that inclusion of curcumin to the conventional chemotherapeutic agent(s)/regimen could be an effective therapeutic strategy for colorectal cancer.  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