全文获取类型
收费全文 | 3064篇 |
免费 | 221篇 |
国内免费 | 75篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 48篇 |
妇产科学 | 48篇 |
基础医学 | 370篇 |
口腔科学 | 49篇 |
临床医学 | 195篇 |
内科学 | 594篇 |
皮肤病学 | 138篇 |
神经病学 | 143篇 |
特种医学 | 44篇 |
外科学 | 559篇 |
综合类 | 274篇 |
预防医学 | 170篇 |
眼科学 | 36篇 |
药学 | 295篇 |
中国医学 | 61篇 |
肿瘤学 | 310篇 |
出版年
2023年 | 53篇 |
2022年 | 64篇 |
2021年 | 136篇 |
2020年 | 100篇 |
2019年 | 217篇 |
2018年 | 175篇 |
2017年 | 114篇 |
2016年 | 81篇 |
2015年 | 92篇 |
2014年 | 180篇 |
2013年 | 164篇 |
2012年 | 118篇 |
2011年 | 179篇 |
2010年 | 139篇 |
2009年 | 164篇 |
2008年 | 137篇 |
2007年 | 141篇 |
2006年 | 141篇 |
2005年 | 106篇 |
2004年 | 88篇 |
2003年 | 93篇 |
2002年 | 54篇 |
2001年 | 62篇 |
2000年 | 46篇 |
1999年 | 35篇 |
1998年 | 30篇 |
1997年 | 28篇 |
1996年 | 23篇 |
1995年 | 23篇 |
1994年 | 15篇 |
1993年 | 9篇 |
1992年 | 12篇 |
1991年 | 12篇 |
1990年 | 5篇 |
1988年 | 8篇 |
1987年 | 8篇 |
1986年 | 8篇 |
1985年 | 21篇 |
1984年 | 48篇 |
1983年 | 29篇 |
1982年 | 42篇 |
1981年 | 30篇 |
1980年 | 26篇 |
1979年 | 22篇 |
1978年 | 18篇 |
1977年 | 6篇 |
1976年 | 16篇 |
1975年 | 17篇 |
1974年 | 9篇 |
1973年 | 7篇 |
排序方式: 共有3360条查询结果,搜索用时 15 毫秒
31.
目的 制备抗弓形虫主要表膜P30抗原单克隆抗体(Mc-Ab)半进行鉴定,为弓形虫病的诊断、抗原的提纯及亚单位疫苗的研制等提供可靠依据。方法 用RH株弓形虫速殖子膜抗原为免疫BALB/C小鼠,取其脾细胞与小鼠SP2/0骨髓瘤细胞融合,筛选出能够稳定分泌高滴度抗P30抗原McAb杂交瘤细胞株,并测定Mc-Ab免疫球蛋白亚类和单抗效价,用IFAT进行单抗识别的抗原定们,并通过SDS-PAGE和Weste 相似文献
32.
An echovirus 30 outbreak with a high meningitis attack rate among children and household members at four day-care centers 总被引:2,自引:0,他引:2
U.C. Vieth M. Kunzelmann S. Diedrich H. Timm A. Ammon O. Lyytikäinen L.R. Petersen 《European journal of epidemiology》1999,15(7):655-658
Echovirus 30 (E 30) outbreaks in defined cohorts have rarely been reported. In June 1996, an outbreak of E 30 occurred in four day-care centers (DCCs) in neighboring villages in Germany. A retrospective cohort study of DCC children, employees and household members was done to determine the extent of the outbreak and risk factors for illness. Forty-two percent (39/92) of DCC children, 13% (30/228) of their household members, 5% (1/19) of employees and 2% (1/49) of household members of employees were ill. Onsets occurred over 31 days. Thirteen percent (12/92) of DCC children had meningitis. In only one of 16 households with multiple family members ill, illness in a family member preceeded that of the DCC child. Household members of ill DCC children were 15 times more likely to report illness than those of non-ill DCC children. We conclude that this outbreak was associated with a very high incidence of meningitis, the outbreak began in the DCCs and then spread to household members, and that household members of ill children compared to those of non-ill children were much more likely to report illness. 相似文献
33.
The focus of the paper is to describe how to present data from studies on health-related quality of life (H-QoL) in a way that is simple and clinically relevant. Data from a longitudinal study of patients with advanced stages of cervix cancer are used. One hundred and eighteen patients filled out questionnaires (including EORTC QLQ-C30) 7 times over a period of 2 years. The following issues are considered: (1) The use of a panel for an initial overview of data. (2) The visual difference between using mean and median values. (3) Box-whisker plots to illustrate the variability of the data. (4) The effect of combining categorical data into fewer categories. (5) Individual patient profiles showing the wide variability among patients. (6) A table showing the change of scores over a one-year period. (7) “Prognostic plots” dividing the initial scores and the following scores. (8) Plotting changes over time. (9) Illustration of the impact of non-random drop-out. (10) The effect of drop-out for the patients who fill out two sequential assessments. (11) The use of healthy controls to help answer the question “what is normal?”. 相似文献
34.
卡托普利控释微丸的研制 总被引:10,自引:0,他引:10
目的:制备卡托普利控释微丸,并对其释药情况进行研究。方法:在流化床内,用丙烯酸树脂RL30D和丙烯酸树脂RS30D的混合物作为包衣材料制备卡托普利控释微丸,对包衣材料配比及包衣材料用量进行选择,对微丸体外释药方程进行研究,采用加速试验法考察微丸释药稳定性。结果:包衣材料最佳配比丙烯酸树脂RL30D-丙烯酸树脂RS30D为1:5,包衣材料最佳用量为包衣增重20%,微丸的体外释药方程为Q=0.09614t-0.008379(r=0.9980),释药稳定性好。结论:卡托普利控释微丸具有良好的零级释药特征。 相似文献
35.
红霉素肠溶微丸制备工艺 总被引:6,自引:0,他引:6
刘海 《中国医药工业杂志》2003,34(2):84-86
采用挤出—滚圆技术制备红霉素微丸丸芯,并用正交设计筛选其制备工艺;以甲基丙烯酸共聚物水分散体为包衣材料,建立微丸包衣数学模型指导包衣工艺。 相似文献
36.
PVP K30对葛根黄豆苷元增溶的研究 总被引:1,自引:0,他引:1
研究了葛根黄豆苷元(1)在不同温度、不同浓度的PVP K30—磷酸盐缓冲液中的溶解度,1溶解度随辅料浓度的增大而明显增大。溶解度数据经热力学方法处理,表明这是个自发过程。采用溶剂法,以PVP K30为载体制备1固体分散体,考察固体分散体中1的溶解度和溶出度。与其本身相比,固体分散体中1溶解度显著提高,溶出速度明显增大。 相似文献
37.
Objective To investigate the expression and relationship of TIP30(HIV-1 Tat interactive protein 2), vascular endothelial growth factor (VEGF) and MVD (detected by CD34) in the angiogenesis of human brain astrocytomas. Methods Expression of TIP30, VEGF and CD34 in 19 cases of normal brain tissue and 71 cases of astrocytoma were immunohistochemically examined with Elivision plus two-step method. Results The positive expression of TIP30 could be seen in cytoplasm of neuroglial cells and neurons of 19 normal brain tissues. The positive expression rate of TIP30 in 71 cases of astrocytoma was 33.80 % (24/ 71). The positive expression rate of TIP30 in astrocytoma of different grades was 52 % for grade Ⅱ, 34.78 % for grade Ⅲ and 13.04 % for grade Ⅳ. The positive expression rate of TIP30 in high grade (Ⅲ+Ⅳ) of astrocytoma was found significantly lower than that in low grade(Ⅱ) (χ2=5.71, P <0.05); The expression of VEGF and MVD detected by CD34 in astrocytomas were higher than that in normal brain tissue and increased as the tumor grade increased; In astrocytoma, the negtive correlation was found between the expression of TIP30 and VEGF (r=-0.428, P<0.05); no correlation was found between TIP30 and MVD(r=-0.065, P 0.05); the positive correlation was found between VEGF and MVD(r=0.684, P<0.01). Conclusion The positive expression rate of TIP30 in normal brain tissue is significantly higher than that in astrocytoma. The positive expression rate of TIP30 significantly decreases as the pathological grade of the astrocytoma increases; The expression of TIP30 and VEGF is negatively correlated in astrocytoma. 相似文献
38.
Objective To investigate the expression and relationship of TIP30(HIV-1 Tat interactive protein 2), vascular endothelial growth factor (VEGF) and MVD (detected by CD34) in the angiogenesis of human brain astrocytomas. Methods Expression of TIP30, VEGF and CD34 in 19 cases of normal brain tissue and 71 cases of astrocytoma were immunohistochemically examined with Elivision plus two-step method. Results The positive expression of TIP30 could be seen in cytoplasm of neuroglial cells and neurons of 19 normal brain tissues. The positive expression rate of TIP30 in 71 cases of astrocytoma was 33.80 % (24/ 71). The positive expression rate of TIP30 in astrocytoma of different grades was 52 % for grade Ⅱ, 34.78 % for grade Ⅲ and 13.04 % for grade Ⅳ. The positive expression rate of TIP30 in high grade (Ⅲ+Ⅳ) of astrocytoma was found significantly lower than that in low grade(Ⅱ) (χ2=5.71, P <0.05); The expression of VEGF and MVD detected by CD34 in astrocytomas were higher than that in normal brain tissue and increased as the tumor grade increased; In astrocytoma, the negtive correlation was found between the expression of TIP30 and VEGF (r=-0.428, P<0.05); no correlation was found between TIP30 and MVD(r=-0.065, P 0.05); the positive correlation was found between VEGF and MVD(r=0.684, P<0.01). Conclusion The positive expression rate of TIP30 in normal brain tissue is significantly higher than that in astrocytoma. The positive expression rate of TIP30 significantly decreases as the pathological grade of the astrocytoma increases; The expression of TIP30 and VEGF is negatively correlated in astrocytoma. 相似文献
39.
Soluble CD30 serum antigen in Kawasaki disease 总被引:4,自引:0,他引:4
C Vagliasindi F Spinozzi L Sensi M Radicioni O De RosaMX L Solinas R Vaccaro A Bertotto 《Acta paediatrica (Oslo, Norway : 1992)》1997,86(3):317-318
40.
Ki-lantigen(CD3o)waslO5oOo/12oooOglycoproteindistinguishedbymonoclonalantibodyKi-lwhichwasmadefromHodgkin'sdisease(HD)cellsstrainL-428,'eXPressedonHDcellsandReed-Sternberg(R-S)cellsatfirstthoughtItwasfoundbySteinandothersinl985,whonamedKi-lstrongpositiveNHLasKi-llymphoma,thatKi-lantigenwasalsoexpressedonsomeNHL.2Theresearchesonthisspecialtypeoflymphomahavealreadyappearedabroad.WehavecollectedfivecasesofKi-lpositiveNHLandnowdiscusstheirclinicalhistopathologicalandimmunophenotypicfe… 相似文献