首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   7561篇
  免费   780篇
  国内免费   48篇
耳鼻咽喉   44篇
儿科学   389篇
妇产科学   188篇
基础医学   859篇
口腔科学   145篇
临床医学   690篇
内科学   1771篇
皮肤病学   211篇
神经病学   1183篇
特种医学   593篇
外国民族医学   2篇
外科学   674篇
综合类   171篇
预防医学   740篇
眼科学   62篇
药学   366篇
中国医学   1篇
肿瘤学   300篇
  2023年   88篇
  2021年   95篇
  2020年   150篇
  2019年   83篇
  2018年   169篇
  2017年   129篇
  2016年   140篇
  2015年   151篇
  2014年   201篇
  2013年   273篇
  2012年   329篇
  2011年   298篇
  2010年   231篇
  2009年   230篇
  2008年   296篇
  2007年   326篇
  2006年   284篇
  2005年   261篇
  2004年   256篇
  2003年   235篇
  2002年   225篇
  2001年   208篇
  2000年   176篇
  1999年   170篇
  1998年   143篇
  1997年   146篇
  1996年   123篇
  1995年   117篇
  1994年   82篇
  1993年   109篇
  1992年   186篇
  1991年   153篇
  1990年   157篇
  1989年   196篇
  1988年   187篇
  1987年   156篇
  1986年   136篇
  1985年   129篇
  1984年   119篇
  1983年   89篇
  1982年   68篇
  1981年   65篇
  1980年   63篇
  1979年   96篇
  1977年   77篇
  1976年   53篇
  1974年   67篇
  1973年   71篇
  1971年   55篇
  1969年   53篇
排序方式: 共有8389条查询结果,搜索用时 15 毫秒
101.
102.
103.
Our objectives were to test the hypotheses that: 1) during shoulder motion, glenohumeral alignment differs between asymptomatic shoulders and those with symptomatic instability; 2) during magnetic resonance (MR)-monitored physical exam or stress testing, glenohumeral alignment differs between asymptomatic shoulders and those with instability; and 3) glenohumeral translation during MR stress testing correlates with findings of shoulder instability by clinical exam and exam under anesthesia (EUA). Using an open-configuration 0.5 T MR imaging (MRI) system, we studied symptomatic shoulders in 11 subjects and compared them to their contralateral asymptomatic shoulders. Each shoulder was studied during abduction/adduction and internal/external rotation to determine the humeral head position on the glenoid. An examiner also performed the MR stress test on each shoulder by applying manual force on the humeral head during imaging. All shoulders were assigned an instability grade from the MR stress test, and this grade was correlated with: 1) clinical exam grade assigned during preoperative assessment by an orthopedic surgeon and 2) intraoperative instability grade by EUA immediately preceding arthroscopy. With dynamic abduction and internal/external rotation, the humeral head remained centered on the glenoid in 9 of 11 shoulders, but in two subjects there were dramatic demonstrations of subluxation. With stress testing, a trend toward more joint laxity was demonstrated in symptomatic than in asymptomatic joints (P = 0.11). MR grading of instability correlated directly with clinical grading in six cases and underestimated the degree of instability relative to clinical exam in the other cases. MR instability grading systematically underestimated instability compared with EUA in 7 of the 10 cases that underwent surgical repair. We concluded that dynamic MR evaluation of glenohumeral alignment did not demonstrate abnormalities in symptomatic shoulders in 8 of 10 patients, whereas 2 patients showed dramatic findings of subluxation. Manual stress testing during dynamic MR examination showed a strong correlation with clinical instability grading. Dynamic shoulder MR examination during stress testing could, with further validation, become a useful adjunct to shoulder instability evaluations. J. Magn. Reson. Imaging 2001;13:748-756.  相似文献   
104.
Hepatic Resection for Colorectal Metastasis: Impact of Tumour Size   总被引:1,自引:0,他引:1  
Background Many colorectal liver metastasis patients are denied surgical resection on the basis of tumour size. The aim of this study was to explore the impact of metastasis size on modern liver resection.Methods Using a prospectively collected database, this was a retrospective analysis of 484 consecutive patients who underwent liver resection for colorectal liver metastases between 1993 and 2003. The cohort was divided into two groups: smaller metastases (<8 cm) and larger metastases (≥ 8 cm). Those with larger metastases were then further stratified into big metastases (8–12 cm) and giant metastases (>12 cm). Demographic, pathological, surgical technique and outcome data were compared between the groups.Results There were 88 (18%) patients with metastases measuring 8 cm or larger. There was an association between higher carcinoembryonic antigen (CEA) and cancer antigen (CA) 19-9 levels and larger metastases. The actuarial 5-year survival for patients with larger metastases was 38% compared with 42% for smaller metastases (not statistically significant). Patients with giant metastases had poorer overall and disease-free survival (both nonsignificant) compared with those with big metastases: 29% and 28% at 5 years, respectively.Conclusion Patients with colorectal liver metastasis greater than 8 cm and up to 12 cm in size should not be treated differently from those with smaller lesions.  相似文献   
105.
Background There is a shortage of general surgeons practicing in rural America. Rural surgical practices differ from those in urban settings encompassing a broader case mix with a larger percentage of time spent performing abdominal, alimentary, gynecological, genitourinary, and orthopedic procedures. Present graduates of many general surgical residencies do not obtain the range of experience necessary to practice effectively in this environment. We hypothesize that general surgical residents undergoing broadly based training are more likely to practice in a rural location. Methods and Materials We conducted a survey of graduates from the Mary Imogene Bassett Hospital’s (MIBH) broadly based surgical residency program in 2004. Additionally, the surgical resident logs from the Accreditation Council for Graduate Medical Education (ACGME) and the residency program were reviewed for years 2001–2004. Results Of the 56 surveys sent out, 42 (75%) were completed and used in the analysis. A majority of the general surgeons who were raised in a rural environment reported that they are residing and practicing in a rural setting. Graduates of the MIBH residency program, on average, performed more cases as residents in the following subspecialty areas: genitourinary, plastics/hand, gynecology, neurosurgery, and orthopedics than national residency graduates. Conclusions Based on our findings, surgical residents graduating from a broadly based training program appear more likely to practice in a rural setting.  相似文献   
106.
A prospective study was done of complications associated with 134 consecutive diagnostic spinal cord arteriograms in 96 patients (63 men and 33 women aged 17-78 years). Patients were examined for either arteriovenous malformation (n = 88) or tumor (n = 8), as indicated by myelography. Among the complications, 11 (8.2%) were local, five (3.7%) were systemic nonneurologic, and three (2.2%) were neurologic (two were associated with full recovery in less than 24 hours, and one was associated with full recovery in less than 1 week). No specific clinical or technical factors were significantly associated with the development of neurologic complications. Details of the clinical profile, angiographic technique, and pathologic findings for each patient were recorded and analyzed with respect to the potential risk for arteriographic complications. Diagnostic spinal cord arteriography had an acceptable risk within the range of other neuroangiographic diagnostic procedures.  相似文献   
107.
108.
PURPOSE: To ascertain the incidence of persistent strabismus in patients treated with plaque brachytherapy and its subsequent treatment. METHODS: A single center retrospective case note review of adult patients with persistent diplopia or strabismus following plaque brachytherapy for all types of intraocular tumors between 1996 and 2004. RESULTS: A total of 929 consecutive adults underwent plaque brachytherapy during the study period at a single center. Sixteen patients (1.7%) with treated uveal melanoma developed persistent diplopia or strabismus. In 11 patients (69%) the timing of onset was in the first year, in 2 (13%) in the second year, and one each (6% each) in years 5, 7, and 8. Two patients (13%) did not require any intervention. Fourteen patients (88%) required treatment: 7 (50%) were treated with prisms only, 3 (21%) underwent botulinum toxin (BTXA) injections, and 4 (29%) were treated with extraocular muscle surgery (3 required one operation and one required 2 procedures). CONCLUSIONS: The incidence of ocular motility disorders following plaque brachytherapy in our cohort was 1.7% over 8 years and we include this in the consent process for conservative treatment of intraocular tumors. Options for treatment for persistent diplopia or strabismus include prisms, botulinum toxin injection, or surgery.  相似文献   
109.
BACKGROUND: Previous clinical trials have shown that adapalene gel produces less irritation than tretinoin gels and tretinoin 0.025% cream. Short term results have shown that adapalene is less irritating than tretinoin gels and creams. This study is the first to compare the 0.1% formulation of adapalene gel with the 0.05% strength of tretinoin cream in a formal clinical trial. OBJECTIVE: To investigate the efficacy and tolerability of adapalene gel 0.1% compared with tretinoin cream 0.05% in patients with mild-to-moderate acne vulgaris. METHODS: Ten-week, multicentre, randomised, investigator-masked, active-controlled, parallel group study in 409 patients with acne vulgaris. RESULTS: Adapalene gel 0.1% demonstrated equivalent efficacy in reduction of acne lesion counts and global improvement of acne severity over 10 weeks' treatment and was significantly better tolerated than tretinoin cream 0.05% in terms of erythema, dryness, desquamation and stinging/burning. CONCLUSION: Adapalene gel 0.1% showed equivalent efficacy and was significantly better tolerated than tretinoin cream 0.05% in patients with mild-to-moderate acne vulgaris.  相似文献   
110.
In countries not generally endemic for hepatitis B, homosexual men who are carriers of hepatitis B surface antigen (HBsAg) have to date largely been spared additional delta virus infection. A focus of homosexually acquired delta has, however, recently been identified in California. To assess the prevalence and risk factors for delta virus infection in homosexual men in Sydney, we tested the sera of 204 homosexual men with acute or chronic hepatitis B infection for total antibody to delta and delta antigen. Total antibody to delta was detected in eight men and delta antigen in one other (4.4% of the total). All men with antibody or antigen had intravenous drug use as a risk factor. Overall nine of 22 (40.9%) male homosexual intravenous drug users had serological evidence of delta infection. Delta positive patients tended to be younger, to have engaged in prostitution, to have more severe chronic liver disease, to be more likely to have a symptomatic acute illness, and to be less likely to express hepatitis Be antigen (HBeAg) in their sera. Though the homosexual transmission of delta infection cannot be concluded from this study, the detection of delta markers in nine homosexual men (including four prostitutes) suggests considerable potential for dissemination of this virus homosexually.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号