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   28431篇
  免费   759篇
  国内免费   157篇
耳鼻咽喉   16篇
儿科学   766篇
妇产科学   14073篇
基础医学   3124篇
口腔科学   91篇
临床医学   1491篇
内科学   1629篇
皮肤病学   198篇
神经病学   440篇
特种医学   268篇
外国民族医学   1篇
外科学   2023篇
综合类   1813篇
现状与发展   1篇
一般理论   21篇
预防医学   1411篇
眼科学   42篇
药学   771篇
  13篇
中国医学   60篇
肿瘤学   1095篇
  2023年   354篇
  2022年   562篇
  2021年   680篇
  2020年   887篇
  2019年   573篇
  2018年   532篇
  2017年   797篇
  2016年   632篇
  2015年   644篇
  2014年   1507篇
  2013年   1382篇
  2012年   1281篇
  2011年   1253篇
  2010年   949篇
  2009年   1059篇
  2008年   754篇
  2007年   1034篇
  2006年   866篇
  2005年   697篇
  2004年   691篇
  2003年   607篇
  2002年   664篇
  2001年   658篇
  2000年   711篇
  1999年   758篇
  1998年   525篇
  1997年   476篇
  1996年   491篇
  1995年   470篇
  1994年   439篇
  1993年   360篇
  1992年   566篇
  1991年   547篇
  1990年   532篇
  1989年   520篇
  1988年   429篇
  1987年   315篇
  1986年   193篇
  1985年   195篇
  1984年   240篇
  1983年   210篇
  1982年   217篇
  1981年   239篇
  1980年   180篇
  1979年   170篇
  1978年   154篇
  1977年   139篇
  1976年   146篇
  1975年   106篇
  1974年   109篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
1.
BackgroundThis study compares morbidity and mortality associated with retroperitoneal and transperitoneal para-aortic lymphadenectomy (PAAL) for pretherapeutic nodal staging of locally advanced cervical cancers (FIGO IB3–IVA).MethodsPre-, per- and postoperative data of patients treated for locally advanced stage cervical cancer between 1999 and 2018 in 12 French referral centers (FRANCOGYN Study Group) were retrospectively collected.ResultsThe study was conducted using a sample of 448 patients, of whom 223 (49,8%) underwent retroperitoneal (group 1) and 225 (50,2%) had transperitoneal PAAL (group 2). No differences were noted concerning clinical and histological characteristics between the two groups. Among these 448 patients, 23 (5,1%) had an intraoperative complication (9 (2,0%) in group 1 and 14 (3,1%) in group 2, p = 0.28) and 47 (10,5%) had a postoperative complication (22 (4,9%) in group 1 and 25 (5,6%) in group 2, p = 0.44), only one of which required revision surgery but the patient died. The length of hospital stay was significantly shorter in group 1 than in group 2 (3.97 versus 4.88 days, p < 0.001). There was no significant difference in mortality between the two groups; 34 of 223 patients in group 1 (15.3%) and 40 of 225 patients in group 2 (15.6%) died (HR = 0.968, 95% CI [0.591–1.585]). There was no significant difference in recurrence-free or overall survival between the two groups.ConclusionRetroperitoneal PAAL appears as a valuable and safety surgical route for nodal staging in locally advanced cervical cancer compared with standard transperitoneal PAAL.  相似文献   
2.
3.
《Clinical breast cancer》2022,22(2):e232-e238
ObjectiveTo evaluate factors contributing to positive surgical margins associated with reflector guidance for patients undergoing breast conserving therapy for malignancy.Materials and MethodsA retrospective IRB-approved review of our institutional database was performed for malignant breast lesions preoperatively localized from January 1, 2018 to December 31, 2020. The following data was recorded using electronic medical records: lesion type and grade, lesion location, reflector and wire placement modality, use of intraoperative ultrasound, margin status, patient age, family history, BMI, and final pathology. Statistical analysis was performed with univariate summary statistics and logistic regression. P < .05 was significant.ResultsA total of 606 image-guided pre-surgical localizations were performed for lumpectomies of breast malignancies. A total of 352 of 606 (58%) wire localizations and 254 of 606 (42%) SCOUT reflector localizations were performed. Sixty out of 352 (17%) of wire-localized patients had positive surgical margins, whereas forty-eight out of 254 (19%) of reflector-localized patients had positive surgical margins. (OR = 1.12, P value: .59). For reflector guided cases, the use of intraoperative ultrasound (IOUS) was associated with decreased positive margin status (OR = 0 .28, 95% CI = [0.14, 0.58]) while in situ disease was associated with increased positive margin status (OR = 1.99, 95% CI = [1.05, 3.75]). No association between modality used for localization (mammography vs. ultrasound) and positive margin status was observed (OR = 0.63, 95% CI = [0.33, 1.19]). No association between positive margins and age, family history, tumor location and BMI was observed.ConclusionFor reflector guided surgeries, the use of IOUS was associated with decreased positive margins, by contrast the presence of ductal carcinoma in situ was associated with increased positive margins. There was no statistically significant difference in surgical outcomes for reflector-guided localization compared to wire localizations of the breast.  相似文献   
4.
Pulmonary thromboembolism (PTE) is an important cause of mortality/morbidity even today despite advancement in clinical understanding as well as diagnostic facilities. Clinical diagnosis of PTE is often challenging because of nonspecific sign/symptoms. Adherence to clinical decision-making protocols and appropriate use of diagnostic modalities like computed tomography pulmonary angiography can resolve the diagnostic dilemma in most cases and help in the overall management of PTE. This article deals with various concerns as well as controversies surrounding accurate diagnosis of PTE as on date.  相似文献   
5.
6.
7.
8.
BackgroundPreschool age is a critical stage of postural balance development. Posturography normative data during this age are crucial for surveillance of postural balance and for the timely diagnosis of any dysfunction. The aim of this study was to provide normative data, specific to Tunisian preschoolers, according to age and gender, and to examine gender- and age-related differences in postural balance.Research questionAre there postural balance gender- and age-related differences in Tunisian preschoolers?MethodsThe study included 410 (205 boys and 205 girls) preschool children aged between 4- and 5-year-old selected within a large geographic area of Tunisia. Postural balance was assessed using a stabilometric platform under 4 sensory conditions. The mean center of pressure velocity (CoP-V) parameter was selected for analysis. Differences between gender and age groups were analysed using the Mann–Whitney U. Normative data were expressed in percentiles.ResultsSignificant gender effect was found in conditions where sensory inputs are most challenged with a significantly smaller mean CoP-V in girls compared to boys (p < 0.05). Moreover, 5-year-old children had significantly better postural balance than 4-year-old ones in almost all conditions (p < 0.05).SignificanceThe normative data established for Tunisian preschoolers provide useful comparative data for pediatricians, teachers and coaches for the early evaluation and monitoring of postural balance during this age. Gender and age-related differences should be considered in this population.  相似文献   
9.
10.
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