全文获取类型
收费全文 | 808297篇 |
免费 | 54225篇 |
国内免费 | 1654篇 |
专业分类
耳鼻咽喉 | 11102篇 |
儿科学 | 27022篇 |
妇产科学 | 20118篇 |
基础医学 | 123181篇 |
口腔科学 | 23783篇 |
临床医学 | 71499篇 |
内科学 | 158086篇 |
皮肤病学 | 19368篇 |
神经病学 | 57766篇 |
特种医学 | 28309篇 |
外国民族医学 | 77篇 |
外科学 | 118137篇 |
综合类 | 15397篇 |
现状与发展 | 2篇 |
一般理论 | 197篇 |
预防医学 | 60365篇 |
眼科学 | 18427篇 |
药学 | 60879篇 |
3篇 | |
中国医学 | 2936篇 |
肿瘤学 | 47522篇 |
出版年
2021年 | 8645篇 |
2019年 | 8319篇 |
2018年 | 11602篇 |
2017年 | 8463篇 |
2016年 | 9187篇 |
2015年 | 10004篇 |
2014年 | 13725篇 |
2013年 | 20369篇 |
2012年 | 27901篇 |
2011年 | 29723篇 |
2010年 | 17017篇 |
2009年 | 15184篇 |
2008年 | 26260篇 |
2007年 | 28091篇 |
2006年 | 28154篇 |
2005年 | 26756篇 |
2004年 | 25809篇 |
2003年 | 24331篇 |
2002年 | 23410篇 |
2001年 | 38384篇 |
2000年 | 39186篇 |
1999年 | 32132篇 |
1998年 | 8509篇 |
1997年 | 7211篇 |
1996年 | 7404篇 |
1995年 | 7020篇 |
1994年 | 6433篇 |
1992年 | 23539篇 |
1991年 | 23402篇 |
1990年 | 22774篇 |
1989年 | 22442篇 |
1988年 | 20380篇 |
1987年 | 19723篇 |
1986年 | 18747篇 |
1985年 | 17559篇 |
1984年 | 12883篇 |
1983年 | 10915篇 |
1982年 | 6079篇 |
1979年 | 11683篇 |
1978年 | 8259篇 |
1977年 | 6917篇 |
1976年 | 6674篇 |
1975年 | 7333篇 |
1974年 | 8608篇 |
1973年 | 8229篇 |
1972年 | 7730篇 |
1971年 | 7212篇 |
1970年 | 6941篇 |
1969年 | 6391篇 |
1968年 | 5857篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
K. Brøsen L. F. Gram P. N. Nielsen K. Brusgaard K. Skjødt 《European journal of clinical pharmacology》1994,47(3):221-225
CYP2D6 genotyping was carried out by XbaI restriction fragment length polymorphism analysis and polymerase chain reaction in 168 healthy Danish volunteers, 77 extensive metabolizers (EM) and 91 poor metabolizers (PM) of sparteine. All EM were genotyped correctly as heterozygous or homozygous for the functional (wild type) gene, D6-wt. However, the D6-wt gene was apparently also present in 11 (12%) of the PM who accordingly were incorrectly genotyped as EM. The specificity of genotyping PM thus was 100% but the sensitivity was only 88%. The most common allele was the D6-wt with an apparent frequency of 0.741 (0.026) in the Danish population and the second most common allele was the D6-B with an apparent frequency of 0.194 (0.024). The median (range) of the sparteine metabolic ratio (MR) in 47 homozygous D6-wt EM was 0.28 (0.11–4.10) and the corresponding value in heterozygous EM was 0.36 (0.11–9.10). The median difference was 0.09 (95% confidence interval: 0.02–0.16). CYP2D6 phenotyping is a promising tool in tailoring the individual dose of tricyclic antidepressants, some neuroleplics and some antiarrhythmics. However if the genotype test could be improved with regard to both sensitivity in PM and the ability to predict CYP2D6 activity in EM then it would be of even greater clinical value in therapeutic drug monitoring. 相似文献
992.
Zh. A. Mamyrbekova S. A. Soldatova V. I. Abelentsev T. I. Solov'eva V. N. Guryshev A. T. Soldatenkov 《Pharmaceutical Chemistry Journal》1994,28(3):198-202
Translated from Khimiko-farmatsevticheskii Zhurnal, Vol. 28, No. 3, pp. 48–51, March, 1994. 相似文献
993.
V. I. Nifontov N. P. Bel'skaya E. A. Shtokareva 《Pharmaceutical Chemistry Journal》1994,28(10):687-706
Translated from Khimiko-farmatsevticheskii Zhurnal, Vol. 28, No. 10, pp. 4–18, October 1994. 相似文献
994.
995.
Pharmaceutical Chemistry Journal - 相似文献
996.
M. Perwaiz Iqbal M. Khalid Ashfaq Sarfaraz K. Niazi M. Mahboobali Khalid N. Khawaja 《Biopharmaceutics & drug disposition》1994,15(2):173-177
Pharmacokinetic parameters of two antifolates, trimethoprim and aditoprim, were studied in buffalo calves. The elimination half-life of aditoprim (6.14 h) was nearly twice as long as that of trimethoprim (3.08 h) and compares well with values observed in heifers. This longer half-life of aditoprim is a result of its much larger distribution volume (four to five times larger) because the clearance of aditoprim was about twice as high as that of trimethoprim. The longer half-life of aditoprim is expected to give a longer duration of in vivo bacteriostatic activity than that of trimethoprim. 相似文献
997.
粮谷尘致肺损害的实验研究 总被引:2,自引:1,他引:1
粮谷尘为混合性粉尘,含游离SiO29.77%,分离培养出普通高温放线菌。染尘动物肺脏早期病变主要为小灶性肺泡炎、灶性间质性肺炎、异物肉芽肿等,大、中支气管壁脱颗粒肥大细胞增多。90d以后,上述病变明显减少,但逐渐出现少数小的细胞结节,间质轻度纤维组织增生、支气管慢性炎症和小叶中央型肺气肿样病变,观察1a(年)未见明显纤维化。 相似文献
998.
Evidence that [3H]-alpha,beta-methylene ATP may label an endothelial-derived cell line 5'-nucleotidase with high affinity. 总被引:1,自引:1,他引:0 下载免费PDF全文
A. D. Michel N. M. Chau T. P. Fan E. E. Frost P. P. Humphrey 《British journal of pharmacology》1995,115(5):767-774
1. In membranes prepared from a permanent cell line of endothelial origin (WEC cells), [3H]-alpha, beta-methylene ATP ([3H]-alpha, beta-meATP) labelled high (pKd = 9.5; Bmax = 3.75 pmol mg-1 protein) and low (pKd = 7.2; Bmax = 23.3 pmol mg-1 protein) affinity binding sites. The high affinity [3H]-alpha, beta-meATP binding sites in the WEC cell membranes could be selectively labelled with a low concentration of the radioligand (1 nM). In competition studies performed at a radioligand concentration of 1 nM, 88.6% of the sites possessed high affinity (pIC50 = 8.26) for alpha, beta-meATP. 2. The high affinity [3H]-alpha, beta-meATP binding sites appeared heterogeneous since in competition studies a number of nucleotide analogues (alpha, beta-meADP, ATP, ADP, AMP, GTP, GppNHp, GMP) and adenosine identified two populations of the sites labelled by 1 nM [3H]-alpha, beta-meATP. The proportion of sites with high affinity for these compounds was found to vary between 42 and 69%. 3. Approximately 60-69% of the binding sites labelled with 1 nM [3H]-alpha, beta-meATP possessed high affinity for alpha, beta-meADP (pIC50 = 8.87), AMP (pIC50 = 7.12), GMP (pIC50 = 7.34), UTP (pIC50 = 6.12), GTP (pIC50 = 7.59), GppNHp (pIC50 = 7.35) and adenosine (pIC50 = 5.45).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
999.
Twenty-eight patients participated prospectively in a study to evaluate the impact of hysteroscopically detected uterine and cervical anomalies on the success rate of ET in an IVF-ET program. All participants had a normal intrauterine cavity by standard HSG. All the patients had a diagnostic office hysteroscopy under paracervical block before commencing COH. Because our IVF program does not include hysteroscopy as a requirement before undergoing IVF and because the significance of mild intrauterine abnormalities is not yet known, the hysteroscopic findings were not relayed to the personnel involved in the IVF-ET procedure. Sixteen patients (group I) had a normal hysteroscopic evaluation. Twelve patients (group II) had abnormal hysteroscopic findings including small uterine septa, small submucous fibroids, uterine hypoplasia and cervical ridges. Although no difference in patients or cycle characteristics was present, there was a significant difference in the clinical PR between patients in groups I and II. In conclusion, in an IVF-ET program patients with normal hysterography but abnormal hysteroscopic findings had a significantly lower clinical PR, demonstrating the importance of performing hysteroscopy before IVF-ET. 相似文献
1000.
B. B. Aleksandrov M. S. Gavrilov R. Z. Dautova R. Kh. Niyazov V. D. Sviridov N. D. Chkanikova B. Ya. Syropyatov V. S. Shklyaev Yu. V. Shklyaev 《Pharmaceutical Chemistry Journal》1992,26(1):57-58
Translated from Khimiko-farmatsevticheskii Zhurnal, Vol. 26, No. 1, pp. 44–45, January, 1992. 相似文献