全文获取类型
收费全文 | 356216篇 |
免费 | 48816篇 |
国内免费 | 2986篇 |
专业分类
耳鼻咽喉 | 7193篇 |
儿科学 | 10644篇 |
妇产科学 | 6760篇 |
基础医学 | 29904篇 |
口腔科学 | 7032篇 |
临床医学 | 49104篇 |
内科学 | 89335篇 |
皮肤病学 | 10140篇 |
神经病学 | 34605篇 |
特种医学 | 13096篇 |
外国民族医学 | 13篇 |
外科学 | 71972篇 |
综合类 | 3651篇 |
现状与发展 | 75篇 |
一般理论 | 291篇 |
预防医学 | 26931篇 |
眼科学 | 7758篇 |
药学 | 15239篇 |
1篇 | |
中国医学 | 380篇 |
肿瘤学 | 23894篇 |
出版年
2023年 | 5859篇 |
2022年 | 2499篇 |
2021年 | 6422篇 |
2020年 | 8113篇 |
2019年 | 5506篇 |
2018年 | 11504篇 |
2017年 | 10918篇 |
2016年 | 11986篇 |
2015年 | 12719篇 |
2014年 | 21547篇 |
2013年 | 24302篇 |
2012年 | 18369篇 |
2011年 | 19567篇 |
2010年 | 18207篇 |
2009年 | 21226篇 |
2008年 | 19134篇 |
2007年 | 18263篇 |
2006年 | 20135篇 |
2005年 | 17955篇 |
2004年 | 16633篇 |
2003年 | 14801篇 |
2002年 | 14387篇 |
2001年 | 5601篇 |
2000年 | 4333篇 |
1999年 | 5173篇 |
1998年 | 6408篇 |
1997年 | 5866篇 |
1996年 | 5533篇 |
1995年 | 5095篇 |
1994年 | 3680篇 |
1993年 | 3220篇 |
1992年 | 2587篇 |
1991年 | 2518篇 |
1990年 | 2071篇 |
1989年 | 2115篇 |
1988年 | 2007篇 |
1987年 | 1847篇 |
1986年 | 1847篇 |
1985年 | 1777篇 |
1984年 | 2023篇 |
1983年 | 1949篇 |
1982年 | 2297篇 |
1981年 | 2020篇 |
1980年 | 1887篇 |
1979年 | 1093篇 |
1978年 | 1266篇 |
1977年 | 1297篇 |
1976年 | 1052篇 |
1975年 | 948篇 |
1974年 | 872篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
991.
A controlled, double-masked, randomized study was conducted on ten subjects to determine the effect of fenestration size on the initial comfort of hydrogel contact lenses. Four fenestrated lenses were tested, each lens containing four mid-peripheral fenestrations of the same size. The diameter of the fenestrations used in the four lenses ranged from 0.39 to 0.96 mm. An unfenestrated lens was also tested. All lenses were made of HEMA and were ordered with the following specifications: -3.00 D, 14.0 mm diameter, 8.4 mm back central optic radius and 0.06 mm centre thickness. There was a significant negative correlation between comfort and fenestration size, indicating that larger fenestrations are less comfortable. Even the lens with the smallest fenestrations (0.39 mm) was significantly less comfortable than the unfenestrated lens. The implication of this finding is that fenestrations may not be clinically efficacious in view of the poor comfort (and presumably increased mechanical effect of the fenestration edges on the tarsal conjunctiva) of fenestrated lenses. 相似文献
992.
In 44 patients with one or more calculi in the upper two-thirds of the ureter, single-stage percutaneous nephrolithotomy was performed through a middle or upper calyceal nephrostomy after cystoscopic placement of an occlusion balloon catheter distal to the calculus; in 42, the procedure was successful. The occlusion balloon catheter permitted retrograde opacification of all systems for enhanced renal puncture. In the last 30 patients an attempt was made either to push the calculus upward mechanically or to flush it upward into the renal pelvis with carbon dioxide or dilute contrast material. This was successful in 24 of these patients. Prior overnight occlusion of the ureter by means of ureteral dilatation further facilitates dislodgment of the calculus, which was successful in 12 of 13 patients. 相似文献
993.
994.
995.
Sadegh Salmassi M. Mitsuo Yokoyama MD John A. Maples and Yoshiki Matsui 《Vox sanguinis》1980,39(5):264-270
Abstract. Paraformaldehyde-fixed platelets from normal donors were used for detection of antibody to platelet by in vitro sensitization (indirect method) utilizing rabbit anti-human IgG heavy chain specific antibody-coated polyacrylamide gels (Immunobeads). The sensitized platelets formed rosettes with Immunobeads and the positive rosette count was over 30%, while control showed less than 8% when normal sera were used. This method was also applicable for detecting antibody-sensitized platelets in vivo (direct method) in patients with autoimmune thrombocytopenia. This method is simple, rapid and reproducible for clinical use. Direct and indirect immunofluorescent antibody tests and a blocking test with anti-human serum also supported the results of Immunobead rosetting technique. 相似文献
996.
Ross W. James Peter A Howat K. John Fisher 《Australian and New Zealand journal of public health》1987,11(1):54-61
Health education campaigns which utilise the mass media generally employ advertising techniques. Television and print media are considered more influential, with radio being primarily used for awareness raising and campaign support messages. There is relatively little research into the effectiveness of radio talkback programs in promoting health or reducing illness. This paper argues a case for health and welfare professionals to utilise talkback radio as part of their health promotion activities. 相似文献
997.
Johannes Bjornsson John R. Goellner David Eugene Williams Mary V. Scheiber 《Journal of cancer research and clinical oncology》1986,111(3):289-290
Preoperative cytologic examinations were performed on bronchial material from 92 patients with postsurgical (pathologic) stage I (American Joint Committee) adenocarcinoma of the lung. All patients were followed up for at least 5 years or until death; thus, cases of adenocarcinoma metastatic to the lungs were virtually excluded. Only 22 patients (24%) had abnormal preoperative cytologic findings. This low cytologic sensitivity is ascribed to the small size and peripheral location of the tumors. Large lesions of high histologic grades were more likely to have positive preoperative cytologic findings than small, well-differentiated ones. 相似文献
998.
In a prospective, randomized, double-blind study, 49 patients underwent lumbar myelography using iotrol (24 patients) or metrizamide (25 patients). The diagnostic imaging adequacy of iotrol was comparable with that of metrizamide. After iotrol myelography, adverse reactions were fewer, less severe, and of shorter duration than were those following metrizamide myelography. Thirteen of 24 patients (54%) receiving iotrol reported some adverse reactions compared with 24 of 25 patients (96%) receiving metrizamide. Five moderate and one severe adverse reaction occurred in the group receiving iotrol. Fourteen moderate and eight severe adverse reactions occurred in the group receiving metrizamide. Thirty-eight patients underwent electroencephalography both before and after myelography (19 iotrol and 19 metrizamide). None of the EEGs obtained after iotrol myelography changed from baseline, while seven of the EEGs obtained after metrizamide myelography showed changes from baseline. Iotrol was judged superior to metrizamide as a contrast medium in this patient population. 相似文献
999.
Siu Fai Li MD Nashat Latib MD Angela Kwong MD Shreni Zinzuwadia MD Ethan Cowan MD 《Academic emergency medicine》2007,14(12):1194-1196
Background In recent years, the number of women entering the field of emergency medicine (EM) has increased.
Objectives To determine if authorship in EM publications has increased in parallel with this trend.
Methods The gender of first and last authors of EM articles in Academic Emergency Medicine , American Journal of Emergency Medicine , Annals of Emergency Medicine , and Journal of Emergency Medicine were examined. The authors reviewed articles from 1985, 1995, and 2005 for American Journal of Emergency Medicine , Annals of Emergency Medicine , and Journal of Emergency Medicine and from 1999 and 2005 for Academic Emergency Medicine . The primary outcomes were the proportions of female authors.
Results A total of 2,016 articles were reviewed. Overall, 18% of first and last authors were female. Respectively, for 1985, 1995, 1999, and 2005, the proportions of female first authors were 9%, 15%, 19%, and 24%; the proportions of female last authors were 9%, 18%, 19%, and 22%. The trend of increases in female authorship was statistically significant.
Conclusions Although female authorship remains a minority in EM publications, it has increased significantly in parallel with increases in female participation in EM. 相似文献
Objectives To determine if authorship in EM publications has increased in parallel with this trend.
Methods The gender of first and last authors of EM articles in Academic Emergency Medicine , American Journal of Emergency Medicine , Annals of Emergency Medicine , and Journal of Emergency Medicine were examined. The authors reviewed articles from 1985, 1995, and 2005 for American Journal of Emergency Medicine , Annals of Emergency Medicine , and Journal of Emergency Medicine and from 1999 and 2005 for Academic Emergency Medicine . The primary outcomes were the proportions of female authors.
Results A total of 2,016 articles were reviewed. Overall, 18% of first and last authors were female. Respectively, for 1985, 1995, 1999, and 2005, the proportions of female first authors were 9%, 15%, 19%, and 24%; the proportions of female last authors were 9%, 18%, 19%, and 22%. The trend of increases in female authorship was statistically significant.
Conclusions Although female authorship remains a minority in EM publications, it has increased significantly in parallel with increases in female participation in EM. 相似文献
1000.
Hidemi Yamauchi MD Kikuo Miyagawa Masamitsu Maeda Seiki Matsuno Toshio Sato 《Surgery today》1986,16(1):8-15
The findings in twenty-two patients with insulinoma were reviewed, as continuous efforts should be made to establish preoperative
localization of the tumor. Superselective arteriography and percutaneous, transhepatic portal vein and pancreatic venous catheterization
are highly recommended approaches. At the time of surgical intervention, a cautious exploration of the pancreas after thorough
mobilization is most important. Recent use of intraoperative ultrasonography increases the likelihood of finding these occult
tumors which locate deeply in the head of the pancreas. Apart from the diagnostic problems, we wish to emphasize the high
incidence of malignancy (7/22, 31.8 per cent) in our series. Althout patients with malignant isulinoma had a much better prognosis
compared to those with a pancreatic ductal malignancy, pancreatic resection with regional lymphnode dissection seems to be
a rational procedure. Enucleation can be done when intraoperative findings of the tumor and regional lymphonode indicate no
malignant features and no multiple lesions. However, at the first operation, enucleation is still a procedure of choice, even
for the malignant insulinoma in the head with a well-defined capsule and no metastatic lesions, the objective being to avoid
a duodenopancreatectomy or total pancreatectomy.
These data were reported at the 30th Congress of Société Internationale de Chirurgie, Hamburg, Germany, 1983 相似文献