全文获取类型
收费全文 | 513448篇 |
免费 | 33922篇 |
国内免费 | 613篇 |
专业分类
耳鼻咽喉 | 6893篇 |
儿科学 | 16841篇 |
妇产科学 | 13522篇 |
基础医学 | 85026篇 |
口腔科学 | 14472篇 |
临床医学 | 44337篇 |
内科学 | 93625篇 |
皮肤病学 | 12159篇 |
神经病学 | 36190篇 |
特种医学 | 18453篇 |
外国民族医学 | 63篇 |
外科学 | 77038篇 |
综合类 | 8471篇 |
一般理论 | 118篇 |
预防医学 | 38969篇 |
眼科学 | 12134篇 |
药学 | 40550篇 |
中国医学 | 1006篇 |
肿瘤学 | 28116篇 |
出版年
2018年 | 4930篇 |
2015年 | 4509篇 |
2014年 | 6061篇 |
2013年 | 9545篇 |
2012年 | 12873篇 |
2011年 | 14271篇 |
2010年 | 8300篇 |
2009年 | 7774篇 |
2008年 | 13695篇 |
2007年 | 14698篇 |
2006年 | 14939篇 |
2005年 | 14356篇 |
2004年 | 14048篇 |
2003年 | 13389篇 |
2002年 | 13267篇 |
2001年 | 24068篇 |
2000年 | 25078篇 |
1999年 | 20557篇 |
1998年 | 5427篇 |
1997年 | 4705篇 |
1996年 | 5041篇 |
1995年 | 4627篇 |
1994年 | 4318篇 |
1993年 | 4135篇 |
1992年 | 15725篇 |
1991年 | 16309篇 |
1990年 | 16422篇 |
1989年 | 15798篇 |
1988年 | 14575篇 |
1987年 | 14421篇 |
1986年 | 13600篇 |
1985年 | 12978篇 |
1984年 | 9629篇 |
1983年 | 8247篇 |
1982年 | 4559篇 |
1981年 | 4229篇 |
1979年 | 9421篇 |
1978年 | 6857篇 |
1977年 | 5773篇 |
1976年 | 5605篇 |
1975年 | 6396篇 |
1974年 | 7635篇 |
1973年 | 7131篇 |
1972年 | 6962篇 |
1971年 | 6689篇 |
1970年 | 6174篇 |
1969年 | 5888篇 |
1968年 | 5559篇 |
1967年 | 5015篇 |
1966年 | 4450篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
S Miyamoto H Kikuchi J Karasawa I Nagata N Yamazoe Y Akiyama 《Journal of neurosurgery》1988,68(4):537-543
Eleven cases of moyamoya disease refractory to indirect non-anastomotic revascularization, including encephalomyosynangiosis in two, encephaloduroarteriosynangiosis in seven, and encephalomyoarteriosynangiosis in two, are described. The patients suffered from recurrent cerebral ischemic symptoms, and further operative intervention, including superficial temporal artery-middle cerebral artery anastomosis and intracranial omental transplantation, was performed. The choice of operative maneuver depended on the availability of scalp arteries and on the nature of the ischemic symptoms. Although indirect non-anastomotic revascularization procedures have the advantage of technical ease and most patients respond to these procedures alone, there are some patients like the 11 presented here who are not cured by such procedures. In such cases, direct anastomotic revascularization is necessary for the prevention of stroke. 相似文献
992.
993.
The chief medical residency in Canada: comparison of opinions between physicians-in-chief and chief medical residents.
下载免费PDF全文
![点击此处可从《Canadian Medical Association journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We conducted a survey of physicians-in-chief (PCs) and chief medical residents (CMRs) in training programs throughout Canada to determine their attitudes toward the need for and role of CMRs in Canada and to rate the importance of CMR duties and attributes. Forty-three hospitals with 5 to 126 house staff in all eight provinces with medical schools were surveyed; 36 PCs (84%) and 29 CMRs (67%) returned a completed questionnaire. Compared with the CMRs the PCs preferred more prior training (p less than 0.03), estimated as significantly less the time spent by CMRs in required duties (p less than 0.05) and rated as more important the responsibilities of faculty-house staff liaison, house staff leader, house staff role model and teaching house staff (p less than 0.05) and the attributes of clinical judgement, medical knowledge, clinician model and research interests (p less than 0.03). All of the PCs and 97% of the CMRs rated the position as somewhat to very necessary; 83% of the PCs and 66% of the CMRs would not alter the present CMR roles. A total of 92% of the PCs felt that the position was very or somewhat advantageous with respect to a future private practice, compared with 67% of the CMRs (p less than 0.02). Increased administrative and committee duties, decreased teaching and future reductions in house staff were identified as major but reversible threats to the unique quality of the CMR position. We conclude that the CMR has a necessary, important and highly regarded role in Canadian university hospitals that could possibly be improved by regular review by the PC and CMR at each hospital to avoid the identified problems. 相似文献
994.
995.
Total anorectal reconstruction with a double dynamic graciloplasty after abdominoperineal reconstruction for low rectal cancer 总被引:7,自引:3,他引:4
Bastiaan P. Geerdes M.D. Frans A. N. Zoetmulder M.D. Ph.D Erik Heineman M.D. Ph.D. Egbert J. Vos M.Sc. Mart -Jan Rongen M.D. Cor G. M. I. Baeten M.D. Ph.D. 《Diseases of the colon and rectum》1997,40(6):698-705
PURPOSE: Total anorectal reconstruction with a double dynamic graciloplasty was performed after abdominoperineal reconstruction
(APR) for low rectal cancer. In four patients an additional pouch was constructed to improve neorectal motility and capacity.
The aim of this study was to evaluate the results in the first 20 patients and to report on the preliminary results of patients
with an additional pouch. METHODS: Twenty patients with a mean age of 52 (range, 25–71) years and a rectal tumor at a mean
of 3 (range, 0–5) cm from the anal verge were treated. In 14 patients the Miles resection, colon pull-through, and construction
of a neosphincter were performed in one session. Six patients had the double graciloplasty at an average of 4.1 (range, 1.1–8.8)
years after APR. In four patients a pouch was constructed with an isolated segment of distal ileum. RESULTS: After a mean
follow-up of 24 (range, 1–60) months after APR, none of the patients developed local recurrence, whereas four patients developed
distant metastasis. Fifteen of 20 patients were available for evaluation, and 5 patients were still in training. Of these
15 patients, 8 patients were continent (53 percent), 2 patients were incontinent, and in 5 patients the perineal stoma was
converted to an abdominal stoma. Failures were attributable to necrosis of the colon stump (n=2) and incontinence (n=3). At
26 weeks mean resting pressure was 44 (standard deviation (SD), 28) mmHg, and mean pressure during stimulation was 90 (SD,
46) mmHg at a mean of 35 (SD, 1.2) volts at 52 weeks. Mean defecation frequency was three times per day (range, 1–5). Of the
eight patients who were continent, six used daily enemas. Mean time to postpone defecation was 11 (range, 0–30) minutes. CONCLUSION:
In experienced hands, the double dynamic graciloplasty is an oncologically safe procedure that can have an acceptable functional
outcome in a well-selected group of patients. However, to improve the outcome, further modifications will be necessary. So
far, the addition of a pouch has not resulted in improved outcome.
Supported by the Profileringsfonds of the Maastricht University Hospital, The Netherlands, and by the Stichting Fondsenwervingsactie
Volksgezondheid, Amsterdam, The Netherlands.
Read in part at the meeting of The American Society of Colon and Rectal Surgeons, Seattle, Washington, June 9 to 14, 1995. 相似文献
996.
997.
Heterogeneous proteolytic specificity and activity of the house dust mite proteinase allergen Der p I 总被引:3,自引:0,他引:3
C. R. A. HEWITT H. HORTON R. M. JONES D. I. PRITCHARD† 《Clinical and experimental allergy》1997,27(2):201-207
Background Exposure of the skin or respiratory tract to proteinases is frequently associated with allergic sensitization. This is of particular significance in the domestic indoor environment where the proteolytic activity of Der p I, the group I allergen of the house dust mite Dermatophagoides pteronyssinus, may influence the allergenicity of mites. Using class-specific proteinase inhibitors and active-site affinity chromatography, we have previously shown that Der p I exhibits a mixed cysteine-serine proteinase activity. Measurement of the amount of cleavage, however, did not determine whether the inhibitors used were targeting exactly the same proteolytic mechanism. Objective To resolve this issue, we have examined whether the cleavage specificity of the cysteine and serine proteinase activities of Der p I was the same. Methods HPLC and mass spectrometry were used to analyse and identify the products of a Der p I-digested peptide substrate and thus identify the peptide bonds cleaved. Results Der p I cleaves different peptide bonds, depending upon the class of proteolytic mechanism used. In the model peptide substrate insulin B chain, the cysteine and serine proteinase activities of Der p I showed preference for glutamic acid and arginine respectively in the P1 position. Conclusion These data suggest the existence of more than one mechanistic form of the allergen immunologically identified as Der p I. If proteolytic activity is indeed a function of allergenicity, this information may have important implications for the pathogenicity of Der p I and the ability of innate antiproteinase defences in the respiratory tract to prevent immune sensitization. 相似文献
998.
999.
S. A. Sergeeva S. V. Krapivin A. S. Losev I. S. Morozov 《Bulletin of experimental biology and medicine》1995,119(3):297-300
It is shown that there is a mathematical correlation between an integral characteristic of activity of the organism (the capacity
for work), electrophysiological indexes of functioning of the brain structures, and the concentration of a novel derivative
of 2-aminoadamantane, bromantane, in the brain. The nature of the correlation between integral characteristics of the organism
studied on different levels is found to change depending on the time elapsed from the administration of the preparation and
on its concentration in the blood or target tissue.
Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N
o
3 pp. 305–308, March, 1995
Presented by M. D. Mashkovskii, Member of the Russian Academy of Medical Sciences 相似文献
1000.
Identification of 12 novel mutations in the CFTR gene 总被引:11,自引:0,他引:11
Audrezet M.P.; Mercier B.; Guillermit H.; Quere I.; Verlingue C.; Rault G.; Ferec C. 《Human molecular genetics》1993,2(1):51-54
Over 200 mutations, besides the deletion 相似文献