全文获取类型
收费全文 | 32454篇 |
免费 | 2238篇 |
国内免费 | 119篇 |
专业分类
耳鼻咽喉 | 241篇 |
儿科学 | 1056篇 |
妇产科学 | 640篇 |
基础医学 | 4414篇 |
口腔科学 | 920篇 |
临床医学 | 3322篇 |
内科学 | 6343篇 |
皮肤病学 | 423篇 |
神经病学 | 3387篇 |
特种医学 | 1240篇 |
外国民族医学 | 6篇 |
外科学 | 4584篇 |
综合类 | 391篇 |
一般理论 | 52篇 |
预防医学 | 2354篇 |
眼科学 | 1124篇 |
药学 | 2316篇 |
中国医学 | 51篇 |
肿瘤学 | 1947篇 |
出版年
2022年 | 201篇 |
2021年 | 433篇 |
2020年 | 275篇 |
2019年 | 449篇 |
2018年 | 544篇 |
2017年 | 442篇 |
2016年 | 482篇 |
2015年 | 545篇 |
2014年 | 777篇 |
2013年 | 1270篇 |
2012年 | 1966篇 |
2011年 | 2157篇 |
2010年 | 1164篇 |
2009年 | 1108篇 |
2008年 | 2053篇 |
2007年 | 2347篇 |
2006年 | 2244篇 |
2005年 | 2274篇 |
2004年 | 2162篇 |
2003年 | 2127篇 |
2002年 | 2039篇 |
2001年 | 313篇 |
2000年 | 242篇 |
1999年 | 309篇 |
1998年 | 464篇 |
1997年 | 421篇 |
1996年 | 317篇 |
1995年 | 334篇 |
1994年 | 323篇 |
1993年 | 314篇 |
1992年 | 242篇 |
1991年 | 219篇 |
1990年 | 194篇 |
1989年 | 162篇 |
1988年 | 167篇 |
1987年 | 148篇 |
1986年 | 182篇 |
1985年 | 188篇 |
1984年 | 308篇 |
1983年 | 278篇 |
1982年 | 340篇 |
1981年 | 307篇 |
1980年 | 319篇 |
1979年 | 163篇 |
1978年 | 192篇 |
1977年 | 196篇 |
1976年 | 133篇 |
1975年 | 135篇 |
1974年 | 124篇 |
1973年 | 87篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
Ronald C. Reinsch MD 《American journal of obstetrics and gynecology》1997,176(6):1381-1383
OBJECTIVE: The purpose of the study was to determine the incidence of isolated choroid plexus cysts in association with trisomy 18 and other abnormalities.STUDY DESIGN: All patients from June 1992 through December 1995 were followed up after a screening ultrasonography. Any patient with a choroid plexus cyst was offered genetic counseling and an amniocentesis. Screening ultrasonographic examinations were performed on 16,059 patients, and 301 patients had a fetus with a choroid plexus cyst. One hundred thirty patients elected to have an amniocentesis. Patients were followed up to delivery.RESULTS: Two hundred sixty-three patients had an isolated choroid plexus cyst. Thirty-eight patients had a choroid plexus cyst associated with additional risk factors. Risk factors included advanced maternal age, additional ultrasonographic abnormalities, past obstetric history, or family history. No abnormalities were noted in the group with an isolated choroid plexus cyst. Four patients had an abnormality when the choroid plexus cyst was associated with an additional risk factor, including two patients with trisomy 18 and one with trisomy 21.CONCLUSION: An isolated choroid plexus cyst was not associated with a trisomy or other abnormalities in this study. When a choroid plexus cyst was associated with an additional risk factor, 10.5% of the patients had an abnormality. Amniocentesis is recommended when a choroid plexus cyst is found in association with additional risk factors. (Am J Obstet Gynecol 1997;176:1381-3.) 相似文献
13.
Sami R Achem MD Alexander Klaus MD Ronald A Hinder MD PhD Kenneth R DeVault MD 《The American journal of medicine》2004,116(10):717-718
14.
Margaretha Jennerwein Ronald Gust Richard Müller Helmut Schnenberger Jürgen Engel Martin R. Berger Dietrich Schmhl Siegfried Seeber Reinhanidt Osieka Ghanem Atassi Danile Marchal-De Bock 《Archiv der Pharmazie》1989,322(2):67-73
The activity of stereoisomeric [1,2-bis(3-hydroxyphenyl)ethylenediamine] dichloroplatinum(II)-complexes (1-PtCl2,R,S; 2-PtCl2, R,R/S,S; 3-PtCl2, R,R; 4-PtCl2, S,S) on several tumor models (MDA-MB 231 breast cancer cell line; P 388 leukemia, mouse; L 1210 leukemia, mouse; L 5222 leukemia, rat; Ehrlich ascites tumor, mouse--wildtype; cisplatin-, etoposide-, cyclophosphamide-, and daunomycin-resistant, resp.) is described. For comparison the analogous [1,2-bis(4-hydroxyphenyl)ethylendiamine]dichloroplatinum (II)-complexes (5-PtCl2, R, S; 6-PtCl2, R,R/S,S; 7-PtCl2, R,R; 8-PtCl2, S,S) and cisplatin are used. 1-PtCl2 to 4-PtCl2 (OH in 3,3'-positions) show their maximum antitumor effect at lower doses than 5-PtCl2 to 8-PtCl2 (OH in 4,4'-positions). 2-PtCl2 and 6-PtCl2 (R,R/S,S) are more active than 1-PtCl2 and 5-PtCl2 (R,S). 4-PtCl2 and 8-PtCl2 (S,S) are superior to 3-PtCl2 and 7-PtCl2 (R,R). On the L 5222 leukemia 2-PtCl2 (R,R/S,S), 4-PtCl2 (S,S) and 8-PtCl2 (S,S) markedly surpass cisplatin. Strong effects are produced by 2-PtCl2 to 4-PtCl2 on the Ehrlich ascites tumor (wildtype, cisplatin-, etoposide-, cyclophosphamide-, and daunomycin-resistant, resp.). The combination of 4-PtCl2 with cisplatin results in a weakly synergistic effect. 相似文献
15.
16.
17.
19.
Ronald Tamler Jeffrey I Mechanick 《Endocrinology & Metabolism Clinics of North America》2007,36(2):533-552
Dietary supplements and nutraceuticals are commonly used by men with erectile dysfunction, decreased libido, BPH, and concerns about developing prostate cancer. Many preparations do not contain the advertised dosages of the active ingredient or are contaminated. Dietary supplements and nutraceuticals, particularly those addressing erectile dysfunction and libido, need to undergo rigorous testing before they can be wholeheartedly recommended. 相似文献
20.