全文获取类型
收费全文 | 2154篇 |
免费 | 177篇 |
国内免费 | 127篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 44篇 |
妇产科学 | 31篇 |
基础医学 | 290篇 |
口腔科学 | 57篇 |
临床医学 | 243篇 |
内科学 | 419篇 |
皮肤病学 | 18篇 |
神经病学 | 106篇 |
特种医学 | 144篇 |
外科学 | 247篇 |
综合类 | 215篇 |
预防医学 | 92篇 |
眼科学 | 33篇 |
药学 | 210篇 |
7篇 | |
中国医学 | 126篇 |
肿瘤学 | 157篇 |
出版年
2024年 | 5篇 |
2023年 | 22篇 |
2022年 | 50篇 |
2021年 | 89篇 |
2020年 | 60篇 |
2019年 | 56篇 |
2018年 | 67篇 |
2017年 | 71篇 |
2016年 | 55篇 |
2015年 | 77篇 |
2014年 | 93篇 |
2013年 | 86篇 |
2012年 | 137篇 |
2011年 | 153篇 |
2010年 | 82篇 |
2009年 | 79篇 |
2008年 | 110篇 |
2007年 | 117篇 |
2006年 | 87篇 |
2005年 | 93篇 |
2004年 | 76篇 |
2003年 | 68篇 |
2002年 | 69篇 |
2001年 | 39篇 |
2000年 | 59篇 |
1999年 | 37篇 |
1998年 | 46篇 |
1997年 | 49篇 |
1996年 | 36篇 |
1995年 | 40篇 |
1994年 | 39篇 |
1993年 | 23篇 |
1992年 | 31篇 |
1991年 | 26篇 |
1990年 | 30篇 |
1989年 | 35篇 |
1988年 | 32篇 |
1987年 | 21篇 |
1986年 | 17篇 |
1985年 | 14篇 |
1984年 | 17篇 |
1983年 | 12篇 |
1982年 | 11篇 |
1981年 | 9篇 |
1980年 | 8篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1972年 | 4篇 |
排序方式: 共有2458条查询结果,搜索用时 369 毫秒
1.
2.
3.
H Ikenaga T Ogihara S Iyori S Kou H Yoshikawa M M Okura 《Postgraduate medical journal》1989,65(768):761-764
A case of a young Japanese woman with long-standing ulcerative colitis complicated by preinfarction angina due to Takayasu's aortitis is presented. Successful emergency aorto-coronary bypass operation was performed. Whether the association of these two diseases can be explained by a common mechanism is discussed. 相似文献
4.
5.
根据热分析谱图峰顶的数学特征与Coats-Redfern方程,推得在一定实验条件下,在系列相关反应中,若峰顶温度相接近,则各反应的表观活化能E与指前因子A之间存在着有动力学意义的补偿效应,即lnA=aE+b。并经系列含水硫酸盐脱水反应实验验证。 相似文献
6.
目的 :探讨检查及治疗喉咽和喉部隐匿或可疑性异物的新手段。方法 :回顾分析用鼻咽纤维喉镜检查治疗 4 8例喉咽及喉部隐匿或可疑性异物的临床资料。结果 :4 8例中 4 6例异物用纤维喉镜一次取出 ,另2例为局部炎性反应 ,经消炎治疗后痊愈。结论 :鼻咽纤维喉镜是检查和治疗喉咽及喉部隐匿性异物的首选方法 相似文献
7.
二陈汤出自宋代《太平惠民和剂局方》,是治痰之基础方。后世医家将二陈汤加减化裁,用于治疗各种痰证,其对现代临床实践也有着很强的指导作用。 相似文献
8.
Sinko P. J. Leesman G. D. Waclawski A. P. Yu H. Kou J. H. 《Pharmaceutical research》1996,13(4):570-576
Purpose. To develop, validate and apply a method for analyzing the intestinal perfusion data of highly permeable compounds using the Numerical Aqueous Resistance (NAR) theory and nonlinear regression (NAR-NLR) and to compare the results with the well-established Modified Boundary Layer (MBL) Analysis.
Methods. The NAR-NLR method was validated and the results were compared to the MBL analysis results using previously reported cephradine jejunal perfusion data. Using the Single Pass Intestinal Perfusion (SPIP) method, the concentration dependence of intestinal permeability was investigated for formycin B, proline, and thymidine, three compounds reported to be absorbed by carrier-mediated transport processes. The MBL and NAR-NLR analyses were then applied to the three sets of SPIP data.
Results. The results demonstrate that the intrinsic MBL transport parameters were highly variable and, in one case, the analyses failed to give a statistically significant Michaelis constant. The MBL mean dimensionless wall permeabilities (P*w) were greater than the NAR-NLR P*w and were also highly variable. In all cases, the NAR-NLR variability was significantly lower than the MBL variability. The extreme variability in the MBL-calculated P*w is due to the sensitivity of P*w when the fraction of unabsorbed drug (Cm/Co) is low or, alternatively, when P*w approached the aqueous permeability, P*aq.
Conclusions. The NAR-NLR method facilitates the analysis of intestinal perfusion data for highly permeable compounds such as those absorbed by carrier-mediated processes at concentrations below their Km. The method also allows for the use of a wider range of flow conditions than the MBL analysis resulting in more reliable and less variable estimates of intestinal transport parameters as well as intestinal wall permeabilities. 相似文献
9.
Ghosh D; Stewart DR; Nayak NR; Lasley BL; Overstreet JW; Hendrickx AG; Sengupta J 《Human reproduction (Oxford, England)》1997,12(5):914-920
The present study was undertaken to assess the temporal association between
the profiles of serum concentrations of oestradiol-17beta, progesterone,
chorionic gonadotrophin (CG) and relaxin in pregnancies established
naturally, and after embryo transfer, as well as in failed pregnancies in
rhesus monkeys. In naturally mated cycles (group 1) a conception rate of
75% was obtained. In group 1, the mean day of CG detection in serum was
11.5 +/- 1.9 day post-ovulation, and for relaxin, 9.0 +/- 2.5 day
post-ovulation. In group 2, embryo transfer to synchronous, non-mated
surrogate recipients was performed; seven embryo transfer cycles yielded
three pregnancies which were allowed to continue to term and normal infants
were delivered. In embryo transfer cycles the mean day of CG detection was
14.8 +/- 1.8 day post- ovulation, and for relaxin, 11.4 +/- 2.6 day
post-ovulation. A delay of about 3 days was observed in the appearance in
circulation of CG (P < 0.05) and also of relaxin (P < 0.05) between
natural mated and embryo transfer conception cycles. Significant
differences (P < 0.05 for progesterone and P < 0.03 for oestradiol)
were obtained for the areas under the curves for progesterone and
oestradiol between days 12 and 16 in conception cycles compared with failed
pregnancies. These data provide the first observation of the normal
hormonal signals associated with maternal recognition of transferred
embryos during the peri- implantation period, and suggest that the use of
such an experimental primate embryo transfer model may help to elucidate
components of maternal and embryonic signal-response mechanisms during
embryo implantation.
相似文献
10.
Abe Y Chinzei T Isoyama T Kobayashi S Ono T Saito I Iwasaki K Ishimaru M Baba A Kouno A Ozeki T Tohyama T Imachi K 《ASAIO journal (American Society for Artificial Internal Organs : 1992)》2003,49(3):325-332
The undulation pump total artificial heart (UPTAH) is a unique, implantable, total artificial heart (TAH) that uses undulation pumps. To achieve long-term survival in animals with physiologic hemodynamic conditions, a control method based on conductance and arterial pressure was applied to UPTAH. With this control method, called 1/R control, survival periods of 50 days (No. 0016, 49.6 kg) and 54 days (No. 0030, 42.5 kg) were obtained in adult female goats. In No. 0016, 1/R control was applied to the left pump, whereas in No. 0030, it was applied to the right pump. Another pump was used for left-right balance control. The control stability was better in No. 0030 than in No. 0016. The sucking effect of the left atrium was remarkable in No. 0016, possibly because of a time delay when left-right balance control was performed with the right pump. In No. 0016, the cause of death was probably a thrombus flown from a panus in the left atrium. It is possible that the left atrial suction effect influenced the thrombus and panus formation in the left atrium. In No. 0030, the cause of death was a small rupture of the membrane in the right pump. The rupture may have been caused by excessive negative pressure inside the pump. This pressure resulted from suction of the right atrium because of an unexpected control excursion, which was probably caused by a software bug. It will be necessary to redesign the undulation pump and improve the software to achieve longer survival periods for animals with physiologic hemodynamic conditions. 相似文献