全文获取类型
收费全文 | 1359篇 |
免费 | 59篇 |
国内免费 | 83篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 62篇 |
妇产科学 | 13篇 |
基础医学 | 221篇 |
口腔科学 | 19篇 |
临床医学 | 176篇 |
内科学 | 294篇 |
皮肤病学 | 36篇 |
神经病学 | 31篇 |
特种医学 | 296篇 |
外国民族医学 | 5篇 |
外科学 | 116篇 |
综合类 | 23篇 |
预防医学 | 55篇 |
眼科学 | 11篇 |
药学 | 98篇 |
肿瘤学 | 42篇 |
出版年
2021年 | 18篇 |
2020年 | 3篇 |
2019年 | 14篇 |
2018年 | 26篇 |
2017年 | 14篇 |
2016年 | 22篇 |
2015年 | 21篇 |
2014年 | 19篇 |
2013年 | 38篇 |
2012年 | 34篇 |
2011年 | 31篇 |
2010年 | 35篇 |
2009年 | 46篇 |
2008年 | 35篇 |
2007年 | 85篇 |
2006年 | 28篇 |
2005年 | 35篇 |
2004年 | 27篇 |
2003年 | 24篇 |
2002年 | 26篇 |
2001年 | 27篇 |
2000年 | 23篇 |
1999年 | 25篇 |
1998年 | 69篇 |
1997年 | 77篇 |
1996年 | 58篇 |
1995年 | 79篇 |
1994年 | 43篇 |
1993年 | 46篇 |
1992年 | 20篇 |
1991年 | 26篇 |
1990年 | 22篇 |
1989年 | 49篇 |
1988年 | 41篇 |
1987年 | 35篇 |
1986年 | 38篇 |
1985年 | 52篇 |
1984年 | 26篇 |
1983年 | 16篇 |
1982年 | 28篇 |
1981年 | 16篇 |
1980年 | 24篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1977年 | 15篇 |
1976年 | 16篇 |
1975年 | 12篇 |
1974年 | 6篇 |
1973年 | 3篇 |
1970年 | 3篇 |
排序方式: 共有1501条查询结果,搜索用时 93 毫秒
71.
72.
TCR gamma delta bearing lymphocyte clones with lymphokine-activated killer activity against autologous leukemic cells 总被引:1,自引:0,他引:1
Activated T lymphocytes with the T-cell receptor (TCR) gamma delta (CD3+ and TCR delta 1+) exhibit strong cytotoxic activity against the standard natural killer (NK) and lymphokine-activated killer (LAK) sensitive target cells. In order to test the cytotoxic activity of gamma delta T lymphocytes against autologous leukemic cells, 84 clones of gamma delta T lymphocytes were obtained from the peripheral blood of three acute lymphoblastic leukemia (ALL) patients. Forty-four of these T-cell clones were active against an LAK-sensitive cell line and the other 40 were active against K562, an NK target cell line. In each of the three patients, cytotoxic clones against autologous leukemic cells were obtained. Among the 84 clones, ten were able to kill autologous tumor cells, including eight that lyse the LAK-sensitive target and two with NK activity. The clones were highly cytotoxic, stable, and easily expanded in large quantity. 相似文献
73.
Herkel J Jagemann B Wiegard C Lazaro JF Lueth S Kanzler S Blessing M Schmitt E Lohse AW 《Hepatology (Baltimore, Md.)》2003,37(5):1079-1085
The ability to activate CD4 T cells is restricted to antigen-presenting cells that express major histocompatibility complex (MHC) class II molecules. Parenchymal cells normally do not express MHC class II molecules; however, in clinical hepatitis, viral or autoimmune, hepatocytes often exhibit aberrant MHC class II expression. It is not known whether MHC class II-expressing hepatocytes can function as antigen-presenting cells, but it has been suggested that aberrant MHC class II expression by parenchymal cells may cause autoimmune disease. Therefore, we generated transgenic mice that specifically overexpress class II transactivator molecules in hepatocytes. Hepatocytes from these mice exhibited stable MHC class II expression and were used to stimulate CD4 T cells from T-cell receptor transgenic mice and CD4 T-cell lines. MHC II-expressing hepatocytes featured costimulatory CD80 molecules and could serve as antigen-presenting cells that were able to process protein antigen and to activate specific CD4 T cells. Nevertheless, the transgenic mice with aberrant hepatocellular MHC class II expression did not exhibit any symptoms of autoimmune disease. In conclusion, MHC II-expressing hepatocytes, as found in clinical hepatitis, can present antigen and activate CD4 T cells. The ability of hepatocytes to present antigen on MHC II molecules does not seem to be a sufficient cause for inflammatory autoimmunity and hepatitis. However, we still need to explore whether such antigen presentation is occurring in vivo. The transgenic mice described in this study may serve as a model to study the immune interaction of hepatocytes and CD4 T cells in both in vitro and in vivo. 相似文献
74.
75.
目的:检测转化生长因子β1在腹膜透析大鼠腹膜内表达,并探讨其在腹膜纤维化中的意义。方法:实验于2005-06/2006-03在中南大学湘雅二医院肾内科实验室完成。①实验材料:雄性SD大鼠,体质量180~240g,由中南大学湘雅二医院动物实验中心提供。②实验方法:将28只大鼠按随机数字表随机分为4组,每组7只。正常对照组不予任何干预;生理盐水组腹腔注射20mL生理盐水;低糖透析液组腹腔注射20mL1.5%葡萄糖透析液;高糖透析液组腹腔注射20mL4.25%葡萄糖透析液,均为1次/d。4周后,向大鼠腹腔注射4.25%葡萄糖腹膜透析液20mL,4h后于大鼠右下腹缓慢插入带有多个侧孔的10号静脉留置针,缓慢低位引流腹透液,量取引流液。③实验评估:取大鼠壁层腹膜组织,以苏木素-伊红染色,镜下测量腹膜厚度,采用免疫组织化学方法检测大鼠腹膜中转化生长因子β1及纤连蛋白。结果:28只大鼠均进入结果分析。①高糖透析液组、低糖透析液组超滤量均明显低于正常对照组与生理盐水组,并且高糖透析液组超滤量明显少于低糖透析液组(P均<0.05)。②高糖透析液组腹膜明显增厚,表面粗糙,间皮细胞肿胀,脱落,间皮下有大量血管生成以及胶原纤维沉积,还可见单核细胞等炎症细胞浸润,与其他组比较,腹膜厚度明显增加(P<0.05)。③高糖透析液组转化生长因子β1、纤连蛋白表达量均明显高于其他组;低糖透析液组转化生长因子β1、纤连蛋白表达量均明显高于正常对照组与生理盐水组(P<0.05)。④大鼠腹膜组织转化生长因子β1蛋白与纤连蛋白表达量、腹膜厚度之间呈明显的正相关(r=0.86,0.83,P<0.05)。结论:葡萄糖透析液可诱导腹膜组织转化生长因子β1明显上调,腹膜转化生长因子β1高表达与腹膜透析腹膜纤维化密切相关。 相似文献
76.
The opportunity to assess the current attitudes of surgeons in the management of thyroid cancer was afforded by the responses to a questionnaire that was part of a "Questionnaire Course." The majority of the 72 respondents have a conservative surgical approach to thyroid cancer, find frozen section useful, recommend total thyroidectomy for medullary cancer, seldom or never split the sternum in performing thyroidectomy, and recommend visualization of the recurrent laryngeal nerves and the parathyroids. Opinions however, are divided on several other issues. Forty-two per cent (versus 34%) request ultrasound before removal of a "cold nodule." For follicular carcinoma, 44 per cent perform lobectomy with isthmustectomy, 29 per cent perform total ipsilateral lobectomy and subtotal contralateral lobectomy, and 23 per cent perform total thyroidectomy. Following lobectomy for follicular carcinoma, recommended treatments are radioactive iodine (25%), thyroid suppression (21%), and total thyroidectomy (48%). For anaplastic cancer, 44 per cent perform total thyroidectomy and 40 per cent perform radiation therapy. Histologically positive nodes are managed by modified radical neck dissection (61%) or by "berry picking" (23%). It is concluded that despite agreement on several therapeutic approaches for thyroid cancer, certain controversial issues remain unresolved. 相似文献
77.
78.
The objective of this study was to determine whether the proposed Malan radiological sinusitis typing (RST) system facilitated a level of agreement and ease of use comparable with the Lund–Mackay (LM) system for chronic rhinosinusitis. Ten observers (one otolaryngologist and nine radiologists), in two separate centres (regional and tertiary), blinded to all clinical data, used these two systems to independently and randomly score and type 15 sets of scans, recording the time to score each film. Using unweighted kappa scores, both methods facilitated a moderate level of agreement, slightly better with the LM system. The Malan system is more time efficient. Preliminarily, this study shows that the Malan RST system is easy to apply with a comparable level of agreement. The Malan RST system is a focused attempt at classifying disease extent radiologically and correlating it to a surgical approach. It emphasizes that scoring systems are vulnerable and proves to be superior to the LM system as a surgical planning tool. To score sinus disease, a Quality‐of‐Life questionnaire in association with this typing method is more appropriate. 相似文献
79.
Roger L Milne Ana Osorio Teresa Ramón Y Cajal Ana Vega Gemma Llort Miguel de la Hoya Orland Díez M Carmen Alonso Conxi Lazaro Ignacio Blanco Ana Sánchez-de-Abajo Trinidad Caldés Ana Blanco Bego?a Gra?a Mercedes Durán Eladio Velasco Isabel Chirivella Eva Esteban Carde?osa María-Isabel Tejada Elena Beristain María-Dolores Miramar María-Teresa Calvo Eduardo Martínez Carmen Guillén Raquel Salazar Carlos San Román Antonis C Antoniou Miguel Urioste Javier Benítez 《Clinical cancer research》2008,14(9):2861-2869
PURPOSE: It is not clear that the published estimates of the breast and ovarian cancer penetrances of mutations in BRCA1 and BRCA2 can be used in genetic counseling in countries such as Spain, where the incidence of breast cancer in the general population is considerably lower, the prevalence of BRCA2 mutations seems to be higher, and a distinct spectrum of recurrent mutations exists for both genes. We aimed to estimate these penetrances for women attending genetic counseling units in Spain. EXPERIMENTAL DESIGN: We collected phenotype and genotype data on 155 BRCA1 and 164 BRCA2 mutation carrier families from 12 centers across the country. Average age-specific cumulative risks of breast cancer and ovarian cancer were estimated using a modified segregation analysis method. RESULTS: The estimated average cumulative risk of breast cancer to age 70 years was estimated to be 52% [95% confidence interval (95% CI), 26-69%] for BRCA1 mutation carriers and 47% (95% CI, 29-60%) for BRCA2 mutation carriers. The corresponding estimates for ovarian cancer were 22% (95% CI, 0-40%) and 18% (95% CI, 0-35%), respectively. There was some evidence (two-sided P = 0.09) that 330A>G (R71G) in BRCA1 may have lower breast cancer penetrance. CONCLUSIONS: These results are consistent with those from a recent meta-analysis of practically all previous penetrance studies, suggesting that women with BRCA1 and BRCA2 mutations attending genetic counseling services in Spain have similar risks of breast and ovarian cancer to those published for other Caucasian populations. Carriers should be fully informed of their mutation- and age-specific risks to make appropriate decisions regarding prophylactic interventions such as oophorectomy. 相似文献
80.
ER Brown KA Charles SA Hoare RL Rye DI Jodrell RE Aird R Vora U Prabhakar M Nakada RE Corringham M DeWitte C Sturgeon D Propper FR Balkwill JF Smyth 《Annals of oncology》2008,19(7):1340-1346
BACKGROUND: Tumour necrosis factor-alpha (TNF-alpha) is an important regulator of the chronic inflammation contributing to tumour progression. Infliximab, an anti-TNF-alpha monoclonal antibody was investigated in this trial of patients with advanced cancer. The primary objectives were to determine the safety profile and biological response of infliximab in a cancer population. Clinical response was a secondary objective. PATIENTS AND METHODS: Forty-one patients received infliximab at 5 mg/kg (n = 21) or 10 mg/kg (n = 20) i.v. at 0 and 2 weeks and then every 4 weeks. Post-treatment samples were measured for changes in plasma and serum TNF-alpha, CCL2, IL-6 and C-reactive protein (CRP). RESULTS: Infliximab was well tolerated with no dose-limiting toxic effects. At both doses of infliximab, neutralisation of serum TNF-alpha was observed after 1 h while plasma CCL2, IL-6 and serum CRP were decreased 24 and 48 h following infliximab administration. Seven patients experienced disease stablisation (range 10-50+ weeks). There was no evidence of disease acceleration in any patient. CONCLUSIONS: Infliximab treatment was safe and well tolerated in patients with advanced cancer. There was evidence of biological activity with baseline TNF-alpha and CCL2 being correlated with infliximab response. 相似文献