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   4253篇
  免费   189篇
  国内免费   64篇
耳鼻咽喉   10篇
儿科学   112篇
妇产科学   26篇
基础医学   998篇
口腔科学   102篇
临床医学   175篇
内科学   484篇
皮肤病学   41篇
神经病学   241篇
特种医学   29篇
外科学   331篇
综合类   401篇
预防医学   437篇
眼科学   16篇
药学   720篇
  1篇
中国医学   262篇
肿瘤学   120篇
  2024年   2篇
  2023年   28篇
  2022年   61篇
  2021年   86篇
  2020年   94篇
  2019年   112篇
  2018年   115篇
  2017年   120篇
  2016年   115篇
  2015年   113篇
  2014年   269篇
  2013年   305篇
  2012年   263篇
  2011年   342篇
  2010年   241篇
  2009年   237篇
  2008年   259篇
  2007年   260篇
  2006年   212篇
  2005年   189篇
  2004年   172篇
  2003年   169篇
  2002年   113篇
  2001年   77篇
  2000年   64篇
  1999年   56篇
  1998年   46篇
  1997年   39篇
  1996年   38篇
  1995年   28篇
  1994年   27篇
  1993年   9篇
  1992年   19篇
  1991年   17篇
  1990年   12篇
  1989年   10篇
  1988年   9篇
  1987年   6篇
  1986年   7篇
  1985年   35篇
  1984年   18篇
  1983年   20篇
  1982年   29篇
  1981年   15篇
  1980年   11篇
  1979年   11篇
  1978年   10篇
  1977年   9篇
  1976年   3篇
  1972年   1篇
排序方式: 共有4506条查询结果,搜索用时 281 毫秒
61.
目的:探讨中药胆必清对内毒素诱导的大鼠腹腔巨噬细胞游离钙浓度的影响。方法:制备大鼠腹腔巨噬细胞并在体外进行孵育,使用荧光探针用荧光法测定钙浓度。巨噬细胞随机分为正常对照组,内毒素LPS组,小、中和大剂量中药组。结果:LPS能诱导巨噬细胞[Ca2^ ]i的升高。加入胆必清后,[Ca2^ ]i可有不同程度的降低。结论:胆必清能抑制LPS诱导的大鼠腹腔巨噬细胞内的[Ca2^ ]i升高,提示该药具有抗炎和免疫调节作用。  相似文献   
62.
目的 :探讨细菌脂多糖 (LPS)对正常成人外周血单核细胞来源的树突状细胞 (Dendritic cell,DC)表面分子表达及免疫功能的影响。方法 :分离正常人 (n=5 )外周血单个核细胞 (PBMC)以 GM-CSF、IL-4联合诱生 DC,实验组在培养的第 2天加入LPS,正常对照组不加。于第 4、8天 FACS检测 DC表面分子 CD1a、CD14、CD83、CD80、HL A-DR的表达。同期检测 DC的增殖和刺激同种异体 T淋巴细胞的增殖情况。结果 :经 LPS刺激后 ,正常人 DC早期、晚期表面分子 CD1a、CD83、CD80表达增高 ,CD14表达降低 (P<0 .0 5 )。DC数量的增加及刺激同种异体 T细胞能力明显增强。结论 :GM-SF、IL-4和 L PS联合刺激能促进正常人 DC的成熟和免疫功能的提高  相似文献   
63.
Pyroptosis is a programmed necrotic cell death executed by gasdermins, a family of pore-forming proteins. The cleavage of gasdermins by specific proteases enables their pore-forming activity. The activation of the prototype member of the gasdermin family, gasdermin D (GSDMD), is linked to innate immune monitoring by inflammasomes. Additional gasdermins such as GSDMA, GSDMB, GSDMC, and GSDME are activated by inflammasome-independent mechanisms. Pyroptosis is emerging as a key host defense strategy against pathogens. However, excessive pyroptosis causes cytokine storm and detrimental inflammation leading to tissue damage and organ dysfunction. Consequently, dysregulated pyroptotic responses contribute to the pathogenesis of various diseases, including sepsis, atherosclerosis, acute respiratory distress syndrome, and neurodegenerative disorders. This review will discuss the inflammatory consequences of pyroptosis and the mechanisms of pyroptosis-induced tissue damage and disease pathogenesis.  相似文献   
64.
The history of tuberculosis control by vaccination with Bacille Calmette-Guérin (BCG) is reviewed. Use of the vaccine is evaluated in light of conflicting results from trials of BCG efficacy. Explanatinations are suggested for the variations between trials, and the continued use of BCG as a vaccine against tuberculosis is discussed.  相似文献   
65.
Summary The expression of foreign gene,Schistosoma Japonicum 26 ku antigen (Sj26GST),in Bacillus Calmette-Guerin (BCG),Mycobacterium CM. smegmatis) andEscherichia coli (E. coli) were studied. The cDNA fragment encoding Sj26GST was amplified by PCR using plasmid pGEX, which could express Sj26GST inE. coli as template. The Sj26GST cDNA was cloned into the downstream of humanM. tuberculosis heat shock protein (hsp) 70 promoter with correct reading frame, and then the DNA fragment containing hsp70 promoter and Sj26GST gene were subcloned together intoE. coli-Mycobacteria shuttle plasmid pBCG-2000 to construct the expression shuttle plasmid pBCG-Sj26. The recombinant BCG andM. smegmatis mc2155, which were electroplated with pBCG-Sj26, could express Sj26GST and the recombinantSchistosoma Japonicum vaccine BCG-Sj26GST was made. The recombinant Sj26GST (rSj26GST) were soluble and could be observed on SDS-PAGE at molecular weight of 26 ku. The content of rSj26GST accounted for 15% and 10% of total bacterial protein in BCG andM. smegmatis respectively. The results of Western blot showed the combination of rSj26GST with antibody of GST. This project was supported by Primary Foundation of China (No. 94-Y-19), Chinese National Nature Science Foundation (No. 339480022) and Chinese Health Foundation (No. 94-1-131).  相似文献   
66.
A novel method of preparing small-sized microcapsules using a Turbotak air-atomizer is reported. Alginate-polylysine microcapsules containing Bacillus Calmette Guérin vaccine have been prepared by an adaptation of the method of Lim (1) which allows the manufacture of small-sized microcapsules. A Turbotak is used to spray sodium alginate solution into calcium chloride solution to form temporary calcium alginate microgel capsules. These temporary microgel droplets are subsequently cross-linked with polylysine to form permanent membranes. Microcapules in the size range of 5–15 µm have been produced which can be compared to an average diameter of 300 µm obtained by the method reported by Lim. The microcapsule size is dependent on the conditions of operation of the Turbotak and the concentration of the sodium alginate solution. Particles within the size range 5–15 µm can be reproducibly manufactured using the conditions of operation reported here. Other size ranges below the minimum of 300 µm reported by Lim are also feasible using this technique.  相似文献   
67.
Summary The cytostatic activity of five Bacillus Calmette-Guérin (BCG) strains (Pasteur, Evans, Tice, RIVM and Connaught) on human transitional cell cancer T24 cells was examined. A striking effect was noted even in 2-day cultures, and the effect was more pronounced when the cells were incubated for 5 days with different BCG strains alone. The concentrations needed were about the same as those used in clinical practice (109 colonyforming units of Pasteur strain in 100 ml buffered saline solution). Combination with mitomycin C or interferon--2b potentiated the cytostatic effect. A slight difference in cytostatic activity between different BCG strains was found.  相似文献   
68.
A nearly fatal allergic reaction to intratumor BCG injections was associated with a complete remission of recurrent malignant melanoma. Clinical course and histologic sections suggested both anaphylactic and Arthus reactions. The occurrence of reactions at BCG injection sites as well as at uninjected sites of tumor suggests common BCG and melanoma antigens. The management of events involved in this often fatal postimmunotherapy complication involves the early administration of parenteral fluids, antituberculous therapy, antihistamines, and possible steroids. The prophylactic use of antihistamines and an in-hospital administration of intralesional BCG immunotherapy are strongly suggested. In the future, prophylactic INH may prove to be both therapeutically efficacious and protective against infectious complications.  相似文献   
69.
目的 观察卡介菌多糖核酸注射液以呼吸道合胞病毒感染后哮喘的预防作用。方法 每周2次,疗程3个月。结果 应用卡介菌多糖核酸注射的患儿哮喘发生率降低。结论 卡介菌多糖核酸注射液能降低呼吸道合胞病毒感染后哮喘患病率。  相似文献   
70.
目的 :评价卡介菌多糖核酸联合CO2 激光治疗女性尖锐湿疣 (CA)的疗效。方法 :治疗组 :CO2 激光治疗后采用卡介菌多糖核酸肌肉注射 ,与对照组单用CO2 激光治疗相比较。结果 :两组经二次CO2 激光治疗后复发率分别为8.3%、31.0 % ,治疗组复发率显著低于对照组 (P <0 .0 1) ,未见明显不良反应。结论 :卡介菌多糖核酸联合CO2 激光治疗女性尖锐湿疣 ,可提高治愈率 ,有效降低复发率 ,安全可靠。  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