全文获取类型
收费全文 | 21290篇 |
免费 | 3117篇 |
国内免费 | 1143篇 |
专业分类
耳鼻咽喉 | 158篇 |
儿科学 | 370篇 |
妇产科学 | 192篇 |
基础医学 | 2025篇 |
口腔科学 | 435篇 |
临床医学 | 2797篇 |
内科学 | 2680篇 |
皮肤病学 | 355篇 |
神经病学 | 931篇 |
特种医学 | 692篇 |
外国民族医学 | 3篇 |
外科学 | 1840篇 |
综合类 | 4265篇 |
现状与发展 | 9篇 |
一般理论 | 5篇 |
预防医学 | 1993篇 |
眼科学 | 593篇 |
药学 | 2752篇 |
30篇 | |
中国医学 | 1915篇 |
肿瘤学 | 1510篇 |
出版年
2024年 | 154篇 |
2023年 | 537篇 |
2022年 | 1296篇 |
2021年 | 1614篇 |
2020年 | 1346篇 |
2019年 | 1010篇 |
2018年 | 1013篇 |
2017年 | 1047篇 |
2016年 | 831篇 |
2015年 | 1220篇 |
2014年 | 1349篇 |
2013年 | 1437篇 |
2012年 | 1841篇 |
2011年 | 1798篇 |
2010年 | 1420篇 |
2009年 | 1122篇 |
2008年 | 1181篇 |
2007年 | 991篇 |
2006年 | 829篇 |
2005年 | 679篇 |
2004年 | 461篇 |
2003年 | 400篇 |
2002年 | 368篇 |
2001年 | 306篇 |
2000年 | 216篇 |
1999年 | 151篇 |
1998年 | 80篇 |
1997年 | 68篇 |
1996年 | 68篇 |
1995年 | 60篇 |
1994年 | 46篇 |
1993年 | 43篇 |
1992年 | 58篇 |
1991年 | 34篇 |
1990年 | 36篇 |
1989年 | 44篇 |
1988年 | 33篇 |
1987年 | 29篇 |
1986年 | 31篇 |
1985年 | 30篇 |
1984年 | 30篇 |
1983年 | 26篇 |
1982年 | 19篇 |
1981年 | 16篇 |
1979年 | 16篇 |
1978年 | 16篇 |
1977年 | 25篇 |
1976年 | 16篇 |
1975年 | 22篇 |
1972年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
The response of glueagon to the change of glucose and its relation to blood pressure in 71 eidely patients with type 2 diabetes was investigated. The results showed that the postprandial increment of glucagon in the group of patients with postprandial 2h plasma glucose increment<2.5 mmol/L was significantly higher than that in the group with plasma glucose inerement≥ 2.5 mmoi/L (P<0. 05). The postprandial increment of glucagon in patients with normal blood pressure was significantly higher than that in patients with hypertension (P<0.05). The results suggest that the decreased response of glucagon to the change in plasma glucose in elderly patients with type 2 diabetes is related to increased blood glucose and high blood pressure. 相似文献
992.
The response of glueagon to the change of glucose and its relation to blood pressure in 71 eidely patients with type 2 diabetes was investigated. The results showed that the postprandial increment of glucagon in the group of patients with postprandial 2h plasma glucose increment<2.5 mmol/L was significantly higher than that in the group with plasma glucose inerement≥ 2.5 mmoi/L (P<0. 05). The postprandial increment of glucagon in patients with normal blood pressure was significantly higher than that in patients with hypertension (P<0.05). The results suggest that the decreased response of glucagon to the change in plasma glucose in elderly patients with type 2 diabetes is related to increased blood glucose and high blood pressure. 相似文献
993.
Immunotherapy of tumors with vaccine based on quail homologous vascular endothelial growth factor receptor-2 总被引:38,自引:0,他引:38
Liu JY Wei YQ Yang L Zhao X Tian L Hou JM Niu T Liu F Jiang Y Hu B Wu Y Su JM Lou YY He QM Wen YJ Yang JL Kan B Mao YQ Luo F Peng F 《Blood》2003,102(5):1815-1823
The breaking of immune tolerance of "self-antigens" associated with angiogenesis is an attractive approach to cancer therapy by active immunity. We used vascular endothelial growth factor receptor-2 (VEGFR-2) as a model antigen to explore the feasibility of the immunotherapy with a vaccine based on a xenogeneic homologous protein. To test this concept, we prepared a quail homologous VEGFR-2 protein vaccine (qVEGFR) based on quail VEGFR-2. At the same time, a protein vaccine based on the corresponding ligand-binding domain of mouse self-VEGFR-2 (mVEGFR) was also prepared and used as a control. We found that immunotherapy with qVEGFR was effective at protective and therapeutic antitumor immunity in several solid and hematopoietic tumor models in mice. Autoantibodies against mouse VEGFR-2 (Flk-1) were identified by Western blot analysis and enzyme-linked immunosorbent assay (ELISA). Anti-VEGFR antibody-producing B cells were detectable by ELISPOT. Endothelial deposition of immunoglobulins developed within tumor. VEGF-mediated endothelial cell proliferation was inhibited in vitro by immunoglobulins from qVEGFR-immunized mice. Antitumor activity was caused by the adoptive transfer of the purified immunoglobulins. Antitumor activity and production of autoantibodies against Flk-1 could be abrogated by the depletion of CD4+ T lymphocytes. Angiogenesis was apparently inhibited within the tumors, and the vascularization of alginate beads was also reduced. No marked toxicity was found in the immunized mice. The observations may provide a vaccine strategy for cancer therapy through the induction of autoimmunity against the growth factor receptor associated with angiogenesis in a cross-reaction with single xenogeneic homologous protein. 相似文献
994.
Incipient speciation by sexual isolation in Drosophila: concurrent evolution at multiple loci
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Ting CT Takahashi A Wu CI 《Proceedings of the National Academy of Sciences of the United States of America》2001,98(12):6709-6713
Drosophila melanogaster from Zimbabwe and nearby regions shows strong but asymmetric sexual isolation from its cosmopolitan counterparts. By creating stable chromosome-substitution lines, earlier studies were able to show that the two major autosomes have very large effects on both male mating success and female mating preference. In this study, we genetically dissect this sexual isolation by recombination analysis between a whole-chromosome substitution line (which carries a Zimbabwe-derived third chromosome) and a strain with seven visible markers on that chromosome. Four loci are responsible for male mating success and three others are found to control female mating preference. Because male and female traits are not closely linked, their strong association among isofemale lines is most likely a reflection of sexual selection in nature. The results suggest that a large number of behavioral loci may evolve concurrently in the incipient stage of speciation before other aspects of reproductive isolation (such as hybrid sterility) have become evident. The results shed light on the population genetic processes underlying the formation of nascent species, as well as modes of speciation. 相似文献
995.
泼尼松联合甲氨蝶呤氯喹治疗系统性红斑狼疮的研究 总被引:1,自引:0,他引:1
目的 回顾性研究 ,旨在探讨PMC治疗 (小剂量泼尼松合并甲氨蝶呤、氯喹 )对于轻、中度活动期SLE患者的疗效及副作用 ,以减少药物用量和副作用。方法 将入选的门诊患者按起始激素剂量 ,分为A (泼尼松剂量≤ 0 2mg·kg-1·d-1)和B (泼尼松 0 5~ 0 6mg·kg-1·d-1)两组 ,并联合应用甲氨蝶呤 7 5~ 10mg/周及氯喹 0 2 5g/d ,各 30例。观察疗效和副作用 ,为期 1年。结果 A组积分由治疗前的 2 1± 1 4降至 0 9± 0 7,B组感染多于A组 (2 2∶7,P <0 0 0 1) ,其中多为肺部感染 ,其次为皮肤感染。B组由 2 9± 2 3降至 1 3± 1 3。二组治疗前后相比疗效显著 ,但A、B两组间的疗效差异无显著性。B组中出现了库兴综合征及股骨头无菌性坏死 ,A组没有。结论 PMC方案对没有严重内脏累及的轻到中度的SLE患者有效。但在加大激素剂量的B组 ,感染问题比较突出 相似文献
996.
Objective To compare the characterization of coronary atherosclerotic plaques in patients with unstable angina pectoris (UAP) and stable angina pectoris (SAP) by optical coherence tomography (OCT). Methods OCT was performed in 47 patients (23 UAP and 24 SAP) undergoing coronary angiography. Lipid-rich plaque (defined by ≥ 2 quandrants of the cross-section area), thin cap fibroatheroma (TCFA), thickness of fibrous cap, plaque rupture, calcification and thrombus visualized by OCT were compared between UAP and SAP patients. Results OCT imaging was successfully in 44 out of 47 patients (22 UAP, 22 SAP). Proportion of lipid-rich plaques was similar between UAP and SAP groups [91% (20/22) vs, 73% (16/22),P =0. 741]. The minimum thickness of fibrous cap in the UAP group was significantly thinner than that in SAP group [(69.5±34.7) μm vs. (141.1±68.5) μm, P = 0.000] and the rate of fibrous cap erosion in the UAP group was significantly higher than that in the SAP group [59% (13/22) vs. 9% (2/22), P=0.000]. Percents of TCFA [73% (16/22) vs. 14% (3/22) ,P = 0.000] and plaque rupture [50% (11/22) vs.9% (2/22) , P = 0.003] were significantly higher in UAP group compared those in SAP group. Incidence of thrombus and calcification were similar between two groups. Conclusions OCT imaging can clearly define plaque characterization of coronary atherosclerosis. UAP patients have thinner fibrous cap, higher incidences of fibrous cap erosion, plaque rupture and TCFA compared patients with SAP. 相似文献
997.
998.
999.
目的:本文旨在研究胃粘膜保护方对消化性溃疡的疗效及机制。方法:经胃镜证实的消化性溃疡患者80例随序给予该方(胃溃疡12例,十二指肠溃疡28例)或甲氰咪胍(胃溃疡10例,十二指肠溃疡30例)对照治疗,8周后胃镜复查,进行比较,并随访1年。实验动物为Wistar大鼠,每组各12只。分别观察对无水乙醇所致胃粘膜损的疗效,对胃酸、胃粘膜及PGE_2的影响。结果:该方组溃疡愈合率(75.0%)与对照组(70.0%)相似,而Hp清除率(55.0%和22.0%)、胃窦炎好转率(50.0%和15.0%)和溃疡1年复发率(35.7%和82.1%)均优于对照组。动物实验表明该方对无水乙醇所致胃粘膜损伤具有保护作用(损伤指数13.8±13.0比75.0±33.0%)。机制与促进胃粘液分泌有关。结论:胃保方治疗消化性溃疡有效,能促进胃粘液分泌,复发率较甲氰咪胍低。 相似文献
1000.
目的 调查某三甲医院医务人员手卫生依从性及影响因素.方法 采取随机抽样的方法,抽取某三甲医院257名医务人员,于2013年的第二季度,由感染管理科专职人员对这257名医务人员进行现场观察、现场提问手卫生相关知识、考核六步洗手法操作并检查各科室洗手设施配备等.结果 医务人员手卫生依从率平均为59.01%,护士手卫生依从性最高,保洁员手卫生依从性最低,六步洗手法正确率87.91%,手卫生知识完全知晓率61.75%,月手消毒剂消毒用量共708 520 ml,部分科室领用量未达到规定标准,手卫生设施不全,手卫生知识培训不够全面及时.结论 某三甲医院医务人员手卫生依从性较低,应加强医务人员的手卫生意识,提高全体医务人员手卫生依从性,以减少医院感染. 相似文献