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   220039篇
  免费   16210篇
  国内免费   6164篇
耳鼻咽喉   1466篇
儿科学   4175篇
妇产科学   2118篇
基础医学   29828篇
口腔科学   4067篇
临床医学   21875篇
内科学   28496篇
皮肤病学   2469篇
神经病学   11120篇
特种医学   4794篇
外国民族医学   28篇
外科学   18758篇
综合类   33643篇
现状与发展   13篇
一般理论   25篇
预防医学   19502篇
眼科学   4800篇
药学   25617篇
  30篇
中国医学   10884篇
肿瘤学   18705篇
  2024年   322篇
  2023年   2326篇
  2022年   4739篇
  2021年   7095篇
  2020年   6123篇
  2019年   8831篇
  2018年   8437篇
  2017年   6979篇
  2016年   6476篇
  2015年   7034篇
  2014年   12022篇
  2013年   12834篇
  2012年   11188篇
  2011年   12350篇
  2010年   10809篇
  2009年   10909篇
  2008年   10232篇
  2007年   12027篇
  2006年   10998篇
  2005年   10393篇
  2004年   8409篇
  2003年   7673篇
  2002年   5725篇
  2001年   5502篇
  2000年   4597篇
  1999年   4218篇
  1998年   3111篇
  1997年   2767篇
  1996年   2736篇
  1995年   2636篇
  1994年   2319篇
  1993年   2049篇
  1992年   1831篇
  1991年   1547篇
  1990年   1306篇
  1989年   1199篇
  1988年   1112篇
  1987年   935篇
  1986年   743篇
  1985年   1308篇
  1984年   1435篇
  1983年   931篇
  1982年   1063篇
  1981年   927篇
  1980年   869篇
  1979年   693篇
  1978年   530篇
  1977年   422篇
  1976年   496篇
  1975年   335篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Co-trimoxazole is mainly used as a first-line drug for treatment and prophylaxis against Pneumocystis jiroveci pneumonia. This drug, however, has been reported as the most common causative drug for severe cutaneous adverse reactions (SCARs). This study aimed to extensively elucidate the associations between genetic polymorphisms of HLA class I and genes involved in bioactivation and detoxification of co-trimoxazole on co-trimoxazole-induced SCARS in a large sample size and well-defined Thai SCARs patients. A total of 67 patients with co-trimoxazole-induced SCARs, consisting of 51 SJS/TEN patients and 16 DRESS patients, and 91 co-trimoxazole tolerant controls were enrolled in the study. The results clearly demonstrated that the HLA-B113:01 allele was significantly associated with co-trimoxazole-induced SCARs, especially with DRESS (OR = 8.44, 95% CI = 2.66–26.77, P = 2.94 × 10−4, Pc = 0.0126). Moreover, the HLA-C108:01 allele was significantly associated with co-trimoxazole-induced SJS/TEN in the HIV/AIDS patients with an OR of 8.51 (95% CI = 2.18–33.14, P = 8.60 × 10−4, Pc = 0.0241). None of the genes involved in the bioactivation and detoxification of co-trimoxazole investigated in this study play any major role in the development of all phenotypes of SCARs.  相似文献   
62.
1. To investigate Genkwa Flos hepatotoxicity, a cell metabolomics strategy combined with serum pharmacology was performed on human HL-7702 liver cells in this study.

2. Firstly, cell viability and biochemical indicators were determined and the cell morphology was observed to confirm the cell injury and develop a cell hepatotoxicity model. Then, with the help of cell metabolomics based on UPLC-MS, the Genkwa Flos group samples were completely separated from the blank group samples in the score plots and seven upregulated as well as two down-regulated putative biomarkers in the loading plot were identified and confirmed. Besides, two signal molecules and four enzymes involved in biosynthesis pathway of lysophosphatidylcholine and the sphingosine kinase/sphingosine-1-phosphate pathway were determined to investigate the relationship between Genkwa Flos hepatotoxicity and these two classic pathways. Finally, the metabolic pathways related to specific biomarkers and two classic metabolic pathways were analyzed to explain the possible mechanism of Genkwa Flos hepatotoxicity.

3. Based on the results, lipid peroxidation and oxidative stress, phospholipase A2/lysophosphatidylcholine pathway, the disturbance of sphingosine-1-phosphate metabolic profile centered on sphingosine kinase/sphingosine-1-phosphate pathway and fatty acid metabolism might be critical participators in the progression of liver injury induced by Genkwa Flos.  相似文献   

63.
目的:采用高效液相色谱-三重四级杆质谱(HPLC-MS/MS)测定清血八味片中的化学成分。方法:在负离子条件下采用Halo C_(18)色谱柱(2.1 mm×100 mm,2.7μm),以0.1%甲酸-10 mmol/L甲酸铵水和乙腈为流动相进行梯度洗脱,质谱采用Scan模式和MRM模式,检测清血八味片中的化学成分。结果:共鉴定出紫草中成分7种、土木香中成分3种、人工牛黄中成分4种、栀子中成分7种、瞿麦中成分7种、甘草中成分12种。结论:该方法快速可靠,操作简便,可用于清血八味片的质量控制研究,为临床药物使用提供一定的依据。  相似文献   
64.
65.
66.
IntroductionThe immunosuppressant agents in kidney transplantation (KT) may lead to various complications such as opportunistic infections and malignancies. BK virus associated nephropathy is a significant complication following KT, and it can result in graft failure. BK virus causes tubulointerstitial nephritis, ureter stenosis, and even graft failure in KT recipients with impaired immune system. We described a 63-year-old woman, who was a hepatitis C carrier and on dialysis for 22 years before KT, who received cadaveric-donor KT 2 years previously. She reported decreasing urine output and general weakness. The serum creatinine level was slightly increased from 2.94 to 4.38 mg/dL.MethodsImmunosuppressant medications including prednisolone, everolimus, cyclosporin, and mycophenolate sodium were continued as maintenance therapy post KT. Kidney biopsy was performed due to deterioration of graft function.ResultsThe kidney biopsy showed consistent results with early-stage polyomavirus nephropathy, characterized by focal viral cytopathic changes with positive immunohistochemical signals and mesangial proliferative glomerulonephritis, immune-complex-mediated (Fig 1 and Fig 2). Negative C4d staining at peritubular capillary was reported. The dosage of mycophenolate sodium was tapered from 720 to 360 mg daily and that of everolimus increased from 0.5 to 1.0 mg daily due to BK viral infection with BK nephropathy. The serum creatinine level was 2.75 mg/dL after treatment.ConclusionEarly detection of BK nephropathy and decreasing immunosuppressant agents are the mainstay of treatment. Substituting leflunomide for mycophenolate sodium and increasing dosage of everolimus has been proposed to solve BK nephropathy. We presented that the use of leflunomide in such situation is in a timely manner.  相似文献   
67.
68.
69.
70.
Background: Intraductal carcinoma and cribriform (IDC/C) tumor features are well-established prognosticators of biochemical recurrence (BCR), metastasis, and prostate cancer (PCa)-specific mortality. However, approximately 70% of PCa patients undergoing a radical prostatectomy are IDC/C negative, yet up-to 20% of these patients progress and experience BCR. Thus, tumor histopathologic characteristics such as IDC/C alone are limited in their ability to predict disease progression. Conversely, several nomograms such as Cancer of the Prostate Risk Assessment-Surgery (CAPRA-S) have been developed to aid in the prognostication of BCR, but not yet widely applied in clinical settings. Materials and methods: In this study, we assessed the combined prognostic utility of IDC/C, and CAPRA-S for BCR in 3 PCa patient cohorts. Results: CAPRA-S+IDC/C improved the predictive accuracy of BCR in all 3 cohorts (P < .001). Specifically, among IDC/C negative cases, CAPRA-S improved the prognostication of BCR in low-risk (Cohort 1; P < .001, Cohort 2; P < .001, Cohort 3; P = .003), intermediate (Cohort 1; P < .001, Cohort 2; P = .006, Cohort 3; P = .03) and high-risk (Cohort 1-3; P < .001) patients. Conversely, IDC/C improved the prognostication of BCR among CAPRA-S low-risk (Cohorts 1; P < .001 and Cohort 3; P = .003) patients. Conclusion: Our results suggest the investigation of histopathological IDC/C features in CAPRA-S low-risk patients and conversely, nomogram CAPRA-S among IDC/C negative patients improves the identification of patients likely to experience BCR, which would otherwise be missed through current assessment regimens. These patients can be offered more intensive monitoring and adjuvant therapies upfront to circumvent the development of recurrent cancer or overtreatment at the time of surgery.  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