全文获取类型
收费全文 | 10458篇 |
免费 | 966篇 |
国内免费 | 351篇 |
专业分类
耳鼻咽喉 | 33篇 |
儿科学 | 91篇 |
妇产科学 | 56篇 |
基础医学 | 1193篇 |
口腔科学 | 280篇 |
临床医学 | 841篇 |
内科学 | 1254篇 |
皮肤病学 | 108篇 |
神经病学 | 571篇 |
特种医学 | 374篇 |
外科学 | 469篇 |
综合类 | 1439篇 |
一般理论 | 1篇 |
预防医学 | 1819篇 |
眼科学 | 100篇 |
药学 | 2113篇 |
5篇 | |
中国医学 | 657篇 |
肿瘤学 | 371篇 |
出版年
2024年 | 32篇 |
2023年 | 132篇 |
2022年 | 318篇 |
2021年 | 472篇 |
2020年 | 398篇 |
2019年 | 328篇 |
2018年 | 327篇 |
2017年 | 364篇 |
2016年 | 402篇 |
2015年 | 399篇 |
2014年 | 670篇 |
2013年 | 773篇 |
2012年 | 586篇 |
2011年 | 665篇 |
2010年 | 494篇 |
2009年 | 482篇 |
2008年 | 442篇 |
2007年 | 406篇 |
2006年 | 390篇 |
2005年 | 335篇 |
2004年 | 281篇 |
2003年 | 296篇 |
2002年 | 240篇 |
2001年 | 202篇 |
2000年 | 163篇 |
1999年 | 173篇 |
1998年 | 159篇 |
1997年 | 155篇 |
1996年 | 128篇 |
1995年 | 122篇 |
1994年 | 119篇 |
1993年 | 104篇 |
1992年 | 106篇 |
1991年 | 96篇 |
1990年 | 91篇 |
1989年 | 96篇 |
1988年 | 93篇 |
1987年 | 75篇 |
1986年 | 73篇 |
1985年 | 88篇 |
1984年 | 74篇 |
1983年 | 56篇 |
1982年 | 58篇 |
1981年 | 45篇 |
1980年 | 47篇 |
1979年 | 50篇 |
1978年 | 38篇 |
1977年 | 42篇 |
1976年 | 29篇 |
1975年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
对食管癌高发区粮食中分离的互隔交链孢霉的毒素交链孢酚单甲醚(AME)在大鼠、小鼠体内的分布进行研究。给动物腹腔内注射氚标记的交链孢酚单甲醚(~3H-AME),然后在不同时间测各脏器的放射性。结果表明:在所测9个脏器中,2h肝脏含量最高,食管下段在大小鼠分别居第四和第三。但大小鼠分别在72、24h则以食管下段最高,说明AME及其代谢物在此清除较慢,即对其有较高的亲和力。 相似文献
22.
Effect of Population Aging on the International Organ Donation Rates and the Effectiveness of the Donation Process 总被引:2,自引:2,他引:0
N. Cuende J. I. Cuende J. Fajardo J. Huet M. Alonso 《American journal of transplantation》2007,7(6):1526-1535
This study analyzed the effect of population aging on organ donation for transplants in 43 countries and on the effectiveness of the donation process by comparing the results between Spain and the United States. The percentage of the population aged 65 or over accounted for 33% of the difference in the donation rates between the countries and for 91% of the variation in the rates after age adjustment. However, the level of aging of the Spanish (16.5%) and American (12.3%) populations failed to account for the percentages of deceased donors 65 or over (28% vs. 10%), due to the different age-specific donation rates, much higher in Spain above 50 years. These differences lead to a higher effectiveness of the process in the United States (3.1 transplanted organs per donor vs. 2.5 in Spain), though at lower rates of transplant per million population (73 vs. 87). We conclude that older populations have a greater donation potential as donation rates are strongly associated with population aging. It should therefore be mandatory to adjust donation rates for age before making comparisons. Additionally, effectiveness decreases with older donors, so age should be considered when establishing standards relating to organ donation and effectiveness of the process. 相似文献
23.
大鼠直肠壁内淋巴管的微细分布和形态特征 总被引:4,自引:0,他引:4
目的观察大鼠直肠壁内淋巴管的分布和形态、结构特点,为探讨直肠癌淋巴道转移的机制,提供形态学依据。方法用半薄、超薄切片、光镜和电镜下观察大鼠淋巴管的微细分布。结果大鼠直肠壁的黏膜固有层深部可见毛细淋巴管,黏膜下层、肌层和浆膜层均有毛细淋巴管和淋巴管。结论直肠壁各层内均有毛细淋巴管,除黏膜层外,还存有淋巴管。 相似文献
24.
Zhen-yu Wu Laurent P. Rivory Michael S. Roberts 《Journal of pharmacokinetics and pharmacodynamics》1993,21(6):653-688
Distribution of Evans Blue (EB), sucrose, and water into the isolated perfused rat hindlimb was studied under various conditions using the multiple indicator dilution (MID) technique. Statistical moment analyses of the outflow profiles for the EB, sucrose, and water were used to define the vascular, extravascular, and total water spaces, respectively. The varied perfusion conditions included albumin content (2, 4.7, and 7%), temperature (25, 37, and 42 C), perfusate flow rate (2, 4, 8, and 12 ml/min) and the presence/absence of red blood cells. The range of studies undertaken were chosen to represent the variety of conditions used in the preparation of both isolated animal and human limbs, the latter being particularly important in cytotoxic therapy for recurrent malignant melanoma. The distribution volumes of EB, sucrose, and water were dependent on the flow rate and the albumin content of perfusate. The normalized variances (CV
2
) of the markers were of the following order: sucrose (2.18) > water (1.58) > EB (0.68), indicating that some disequilibrium occurs during the capillary exchange of water and sucrose. It is suggested that a Krebs-Henseleit buffer containing 2% BSA is a suitable perfusate for most studies of the isolated rat hindlimb perfusion. The effect of albumin concentration manifests itself only at higher flows.We acknowledge the support of the National Heart Foundation (Queensland) and the Mayne Bequest Foundation. This study was conducted while the investigator (Z.Y. Wu) was in receipt of a WHO Research Training Grant. Professor M. S. Roberts also acknowledges the support of the Queensland and Northern New South Wales Lions Kidney & Medical Research Foundation. 相似文献
25.
对全国部分城乡家鼠鼠情监测三年结果的分析表明:城乡家鼠组成均以三大家鼠(褐家鼠、小家鼠、黄胸鼠)为主,其次为食虫目臭鼩鼱~#和黑线姬鼠。五种主要鼠种在家鼠组成中的数量比基本稳定,但三年中城乡少数鼠种间的顺位有所变化。监测结果亦表明,五种主要鼠种的地区分布是:褐家鼠、小家鼠遍布所有监测的省、市、区,同以往文献中遍布全国的说法一致;黄胸鼠分布于黄河以南;食虫目中的臭鼩鼱分布于华中区以南的广大地区。这在以往文献中均已有记载,但以往文献有关黄胸鼠和臭鼩鼱分布的其他说法,则被证实为不确切的。黑线姬鼠的分布范围已超过以往文献中关于分布于东北、华北及长江流域的说法,但以往文献中关于该鼠种遍及全国的说法是否正确,则有待进一步证实。 相似文献
26.
The influence of support conditions in the loading fixture on failure mechanisms in the push-out test: a finite element study 总被引:1,自引:0,他引:1
The usefulness of the push-out test as an indicator of interface strength was evaluated using finite element models of intact and partially failed cylindrical push-out specimens loaded against a rigid annular support. The irregular stress distributions that were found in intact specimens depended more on interface conditions at the loading fixture than on a 35% increase in interface area. The maximum stress at the interface was a tensile stress. Critical energy release rates for interface failure were calculated for flawed specimens in which flaw size was either 10 or 100 microns, and for boundary conditions at the loading fixture that were either fixed or slipping in the radial direction. The critical energy release rates depended heavily on the support boundary conditions. Thus, the results of parametric push-out tests can be reasonably compared only for specimens that are very similar in geometry and that are loaded in very carefully controlled fixtures. 相似文献
27.
应用流式细胞计对30例宫颈腺癌和混合癌细胞的DNA指数和细胞增殖周期各时相细胞分布比例进行分析,结果显示非整倍体肿瘤29例,占96.7%.流式细胞计在诊断恶性肿瘤方面是有价值的。细胞增殖周期比DNA指数对预后的估价更有意义.乳头型腺癌、分化I级的肿瘤,S+G2M比率最低,5年生存率最高. 相似文献
28.
采用淀粉凝胶电泳法对云南水族人红细胞酸性磷酸多态分布状况进行了调查,检出EAPA型6例,EAPBA型45例,EAP55例。计算出基因频率分别为:EAP^A0.2689,EAP^B0.7311.EAP在云南水族人群中的DP值为0.5185。文中对EAP在不同人群中的分布进行了比较分析。 相似文献
29.
30.
浅谈我国卫生资源配置现状 总被引:2,自引:0,他引:2
当前,我国卫生资源配制在地域上分布不合理。此外,公共卫生投入不足及卫生人力资源配制失衡也制约着卫生资源的合理配置。 相似文献