全文获取类型
收费全文 | 10982篇 |
免费 | 818篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 135篇 |
儿科学 | 243篇 |
妇产科学 | 238篇 |
基础医学 | 1366篇 |
口腔科学 | 293篇 |
临床医学 | 1294篇 |
内科学 | 1904篇 |
皮肤病学 | 91篇 |
神经病学 | 1192篇 |
特种医学 | 397篇 |
外科学 | 1906篇 |
综合类 | 113篇 |
一般理论 | 13篇 |
预防医学 | 1215篇 |
眼科学 | 154篇 |
药学 | 611篇 |
中国医学 | 7篇 |
肿瘤学 | 655篇 |
出版年
2022年 | 77篇 |
2021年 | 172篇 |
2020年 | 114篇 |
2019年 | 180篇 |
2018年 | 182篇 |
2017年 | 204篇 |
2016年 | 197篇 |
2015年 | 239篇 |
2014年 | 317篇 |
2013年 | 508篇 |
2012年 | 670篇 |
2011年 | 704篇 |
2010年 | 387篇 |
2009年 | 340篇 |
2008年 | 618篇 |
2007年 | 720篇 |
2006年 | 751篇 |
2005年 | 725篇 |
2004年 | 707篇 |
2003年 | 676篇 |
2002年 | 608篇 |
2001年 | 124篇 |
2000年 | 107篇 |
1999年 | 120篇 |
1998年 | 143篇 |
1997年 | 133篇 |
1996年 | 92篇 |
1995年 | 102篇 |
1994年 | 93篇 |
1993年 | 86篇 |
1992年 | 76篇 |
1991年 | 66篇 |
1990年 | 63篇 |
1989年 | 60篇 |
1988年 | 64篇 |
1987年 | 61篇 |
1985年 | 69篇 |
1984年 | 59篇 |
1983年 | 72篇 |
1982年 | 75篇 |
1981年 | 67篇 |
1980年 | 69篇 |
1979年 | 57篇 |
1978年 | 59篇 |
1976年 | 55篇 |
1973年 | 52篇 |
1971年 | 54篇 |
1970年 | 64篇 |
1969年 | 50篇 |
1968年 | 53篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Factors associated with hypertension in Nigerian civil servants 总被引:3,自引:0,他引:3
Clareann H. Bunker Ph.D. Flora A. Ukoli M.B.B.S. Martin U. Nwankwo M.B.B.S. Jackson A. Omene M.D. Glenn W. Currier M.D. Linda Holifield-Kennedy Donald T. Freeman Emanuel N. Vergis M.D. Lan Lan L. Yeh Ph.D. Lewis H. Kuller M.D. Dr.P.H. 《Preventive medicine》1992,21(6):710-722
BACKGROUND. Study of hypertension in segments of West African populations in transition toward Westernization may lead to better understanding of the high risk for hypertension among Westernized blacks. METHODS. Five hundred fifty-nine urban civil servants, ages 25-54, were recruited from six ministries of Bendel State, Nigeria. Blood pressure, physical measurements, urinary protein and glucose, fasting blood glucose, and demographic data were collected at the workplace. Subjects were classified as senior staff (professionals or administrators) or junior staff (non-administrators). RESULTS. Among 172 male senior staff, the age-adjusted rate of hypertension (diastolic blood pressure > or = 90 mm Hg, systolic blood pressure > or = 140 mm Hg, or on an antihypertensive medication) was 43% and occurrence rose dramatically from 21 to 63% across age groups 25-34 to 45-54, respectively. Among 266 male junior staff, the age-adjusted rate of hypertension was 23%, and occurrence did not rise with age. Logistic regression showed that body mass index (kg/m2), age, alcohol drinking, and being senior staff were all independently related to hypertension in men. On the other hand, the age-adjusted rate of hypertension in 121 women was 20% and was significantly related only to body mass index. CONCLUSION. Male urban civil servants appeared to have a risk for hypertension similar to that of U.S. black males. Age, body mass index, alcohol drinking, and other unidentified factors related to higher socioeconomic status were strong determinants of hypertension in this population. 相似文献
22.
Ann M Henry Cathy Wilkinson James P Wylie John P Logue Pat Price Vincent S Khoo 《Radiotherapy and oncology》2004,73(1):57-59
On-line imaging of prostate markers can be used to compensate for errors in radiation delivery. This study assessed the patient acceptability and morbidity associated with the trans-perineal route of implantation. A minority experienced acute pain or bleeding. Placement was accurate in all but one subject. An operator related learning curve exists. Although this is an invasive procedure most patients found it acceptable. Implementation for routine clinical practice is feasible. 相似文献
23.
Valerie J. Gillet Glenn Myatt Zsolt Zsoldos A. Peter Johnson 《Perspectives in Drug Discovery and Design》1995,3(1):34-50
Summary Several components of a system for structure generation are now well developed. HIPPO is a program that characterises a receptor binding site for potential target sites within the cavity that can be used in de novo design. The target sites include simple and complex hydrogen bonds, covalent bonds and bonds to metal ions. The SPROUT program for structure generation consists of two main components: the first is skeleton generation, followed by atom substitution to convert the solution skeletons to molecules. A new method of skeleton generation is presented here, where part skeletons are grown outwards from each target site. The part skeletons are then connected together to form solution skeletons. Finally the CAESA program is described, that ranks the output from SPROUT according to ease of synthesis. 相似文献
24.
25.
Mesenteric cyst is one of the rarest abdominal tumours, with approximately 820 cases reported since 1507. The incidence varies from 1 per 100000 to 250000 admissions. The lack of characteristic clinical features and radiological signs may present great diagnostic difficulties. The cyst may present in one of three ways: (i) non-specific abdominal features; (ii) an incidental finding; or (iii) an acute abdomen. Abdominal pain is the major presenting symptom. Abdominal mass is found in more than 50% of cases and 40% of cases are discovered incidentally. More than one aetiological mechanism is probably involved in the development of mesenteric cysts. Mesenteric cysts have been reported from the duodenum to the rectal mesentery but are most commonly located in the ileal mesentery. Malignant cysts occur in less than 3% of cases. Enucleation of the cyst is the treatment of choice. Knowledge of these tumours is important due to the various complications associated with suboptimal surgical management. Two cases of mesenteric cysts are presented including a recurrent mesenteric cyst in a post-partum woman demonstrating the inferior technique of internal marsupialization. The association of mesenteric cyst with pregnancy is discussed. 相似文献
26.
27.
In their article in this journal “Is well-being U-shaped over the life cycle?” Blanchflower and Oswald (Blanchflower, D.G., & Oswald, A.J. (2008). Is well-being U-shaped over the life cycle? Social Science & Medicine, 66, 1733–1749) report the results of an ambitious cross-national study of age and well-being and conclude that in most societies studied the well-being of adults tends to be high in young adulthood and old age and lowest around age 40. I argue that the appearance of this U-shaped curve of well-being is the result of the use of inappropriate and questionable control variables. The most clearly inappropriate control variable is marital status, the control of which to a large extent accounts for the U-shaped curve. Most researchers who have studied the relationship between being married and being happy believe that happiness affects marital status (happier people are more likely to marry and stay married), and of course a variable that is affected by the dependent variable should not be included as a control variable in a simple recursive model. Such control variables as income and education are suspect because the relationship between them and well-being is likely to be partially spurious, and such variables as race and whether or not persons lived with both parents at age 16 should not be controlled, because they cannot affect or be affected by age. Finally, year of survey should not be controlled because of the age-period-cohort conundrum, which makes including age, period, and cohort all as predictor variables in a regression inappropriate (and impossible if the three variables are measured precisely and comparably). The only clearly appropriate control variable is birth cohort, and when only it is controlled, the regression data become estimates of how the well-being of persons has actually changed as they have gone through the life course. I argue that such estimates are much more useful than the counterfactual abstractions provided by Blanchflower and Oswald (Blanchflower, D.G., & Oswald, A.J. (2008). Is well-being U-shaped over the life cycle? Social Science & Medicine, 66, 1733–1749), and I conclude that those authors (or someone else) could make a very important contribution by redoing their analyses with birth cohort as the only control variable. I do that with the American happiness data and find that the results do not come close to the U-shaped pattern. 相似文献
28.
Christopher G Goetz Stanley Fahn Pablo Martinez-Martin Werner Poewe Cristina Sampaio Glenn T Stebbins Matthew B Stern Barbara C Tilley Richard Dodel Bruno Dubois Robert Holloway Joseph Jankovic Jaime Kulisevsky Anthony E Lang Andrew Lees Sue Leurgans Peter A LeWitt David Nyenhuis C Warren Olanow Olivier Rascol Anette Schrag Jeanne A Teresi Jacobus J Van Hilten Nancy LaPelle 《Movement disorders》2007,22(1):41-47
This article presents the revision process, major innovations, and clinimetric testing program for the Movement Disorder Society (MDS)-sponsored revision of the Unified Parkinson's Disease Rating Scale (UPDRS), known as the MDS-UPDRS. The UPDRS is the most widely used scale for the clinical study of Parkinson's disease (PD). The MDS previously organized a critique of the UPDRS, which cited many strengths, but recommended revision of the scale to accommodate new advances and to resolve problematic areas. An MDS-UPDRS committee prepared the revision using the recommendations of the published critique of the scale. Subcommittees developed new material that was reviewed by the entire committee. A 1-day face-to-face committee meeting was organized to resolve areas of debate and to arrive at a working draft ready for clinimetric testing. The MDS-UPDRS retains the UPDRS structure of four parts with a total summed score, but the parts have been modified to provide a section that integrates nonmotor elements of PD: I, Nonmotor Experiences of Daily Living; II, Motor Experiences of Daily Living; III, Motor Examination; and IV, Motor Complications. All items have five response options with uniform anchors of 0 = normal, 1 = slight, 2 = mild, 3 = moderate, and 4 = severe. Several questions in Part I and all of Part II are written as a patient/caregiver questionnaire, so that the total rater time should remain approximately 30 minutes. Detailed instructions for testing and data acquisition accompany the MDS-UPDRS in order to increase uniform usage. Multiple language editions are planned. A three-part clinimetric program will provide testing of reliability, validity, and responsiveness to interventions. Although the MDS-UPDRS will not be published until it has successfully passed clinimetric testing, explanation of the process, key changes, and clinimetric programs allow clinicians and researchers to understand and participate in the revision process. 相似文献
29.
30.
Christian Lee Norman Tinanoff Glenn Minah Elaine Romberg 《Journal of public health dentistry》2008,68(1):57-60
OBJECTIVES: Visible plaque on the maxillary anterior teeth of young children has been identified as a risk indicator for early childhood caries. The present study examined whether this plaque is related to the colonization of children's teeth with Mutans streptococci (MS) or toothbrushing frequency. METHODS: Thirty-nine children, aged 12 to 36 months, had plaque scores, and plaque samples were taken from the labial surfaces of the maxillary incisors at baseline and repeated 3 days after suspended oral hygiene (plaque regrowth). RESULTS: A positive correlation was found between the baseline percent MS and regrowth plaque score and between baseline and regrowth plaque scores. Plaque scores of those that brushed zero to one time a day were not different from those who brushed two or more times a day. CONCLUSIONS: This study suggests that the presence of plaque on the anterior teeth of young children is consistent and related to MS colonization. 相似文献