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   3503篇
  免费   232篇
  国内免费   33篇
耳鼻咽喉   28篇
儿科学   69篇
妇产科学   99篇
基础医学   526篇
口腔科学   112篇
临床医学   247篇
内科学   900篇
皮肤病学   168篇
神经病学   269篇
特种医学   70篇
外科学   342篇
综合类   8篇
预防医学   187篇
眼科学   16篇
药学   364篇
中国医学   12篇
肿瘤学   351篇
  2024年   4篇
  2023年   41篇
  2022年   69篇
  2021年   136篇
  2020年   87篇
  2019年   123篇
  2018年   111篇
  2017年   102篇
  2016年   92篇
  2015年   125篇
  2014年   155篇
  2013年   168篇
  2012年   268篇
  2011年   302篇
  2010年   149篇
  2009年   150篇
  2008年   245篇
  2007年   217篇
  2006年   189篇
  2005年   206篇
  2004年   168篇
  2003年   153篇
  2002年   120篇
  2001年   40篇
  2000年   39篇
  1999年   34篇
  1998年   19篇
  1997年   24篇
  1996年   20篇
  1995年   16篇
  1994年   16篇
  1993年   11篇
  1992年   18篇
  1991年   20篇
  1990年   17篇
  1989年   8篇
  1988年   15篇
  1987年   14篇
  1986年   17篇
  1985年   8篇
  1984年   9篇
  1983年   8篇
  1980年   5篇
  1979年   5篇
  1975年   4篇
  1974年   2篇
  1973年   2篇
  1969年   2篇
  1967年   2篇
  1966年   3篇
排序方式: 共有3768条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
Background: Biliopancreatic diversion (BPD), by ad hoc stomach resection (AHS-BPD) has been accepted as an effective surgical treatment for morbid obesity. Methods: Between 1.1.1992 and 31.7.1996, 59 patients (54 females, five males, mean age 40.3 years, range 23-61 years) underwent AHS-BPD. Mean preoperative body-weight was 121.2 kg (range 94-160), with a mean body mass index of 48.6 (range 35-64). Three of these patients were converted from a previous vertical banded gastroplasty to AHS-BPD (one patient with stomach preservation). After at least 36 months follow-up, seven patients underwent abdominal dermolipectomy (five with associated incisional hernia repair, one with thigh dermolipectomy). Results: Mean post-operative hospital stay was 13 days (range 10-30 days). Follow-up is currently in progress in all patients. Excess body weight-loss was 78% in 33 patients with 24 months follow-up, with excellent long-term weight loss maintenance. Protein deficiency was the main specific complication, encountered in two patients (3.4%). Mortality was one patient (1.7%), due to pulmonary embolus. Conclusions: This clinical experience supports the effectiveness and safety of AHS-BPD, despite some criticism. This procedure appears to be suitable for patients with clinically severe obesity who will poorly tolerate food intake restriction but will accept long-term follow-up. Careful preoperative clinical assessment and selection of patients who will be reliable in long-term follow-up are the keys to success with AHS-BPD, both in terms of weight loss and reduction of specific metabolic complications.  相似文献   
7.
The immunohistochemical occurrence of the high affinity neurotrophin (NT) receptors trkA, trkB, and trkC is shown in the pre-term newborn, infant, and adult human post-mortem cerebellum. Immunoreactive neuronal perikarya and processes were observed in all specimens examined, where they appeared unevenly distributed in the cerebellar cortical layers and deep nuclei, and showed regional differences among cerebellar lobules and folia. The trk receptor-antibodies, tested by Western blot on human cerebellum homogenates, revealed multiple immunoreactive bands for trkA and single bands for trkB and trkC. The results obtained show the tissue localization of the trk receptor-like immunoreactivity in the human cerebellum from prenatal to adult age. The analysis for codistribution of the receptors with the relevant ligand and among the receptors in discrete cortical and deep nuclei tissue fields shows a wide variety of conditions, from a good similarity in terms of type and density of labeled structures, to a lack of correspondence, and suggests the possibility of colocalization of trk receptors with the relevant neurotrophin and among them in the cerebellar cortex. These results sustain the concept that the neurotrophin trophic system participates in the development, differentiation, and maintenance of the human cerebellar connectivity and support the possibility of a multifactorial trophic support for the neurotrophins through target-derived and local mechanisms.  相似文献   
8.
Available results highlight the lack of good level of evidence studies on the pure prognostic value of histological grade. In the present study, the prognostic relevance of histological grade and of its three components, tubule formation, nuclear pleomorphism and mitotic count, was analyzed in a series of 372 patients with node-negative breast cancer treated with locoregional therapy alone until early relapse. Histological grade was determined blindly by two observers and discordance between evaluations was resolved after joint review using a multihead microscope. No relation was observed between histological grade and any of its three components and disease-free survival. Conversely, a significant relation was observed between histological grade and distant metastasis-free survival (at 6 years, 94, 86 and 76% for grades 1, 2 and 3, respectively, P=0.013) as well as overall survival (98, 90 and 86%, P=0.001). A breakdown analysis as a function of the three components showed that neither tubule formation nor nuclear pleomorphism was associated with prognosis, and only mitotic count strongly influenced both distant metastasis-free survival (91, 82 and 74%, P=0.014) and overall survival (97, 87 and 85%, P=0.011). Histological grade suffers from a much higher subjectivity than any other microscopic evaluation of biomarkers as it is the sum of three different morphological features. Within the Italian Network for Quality Assessment of Tumor Biomarkers program we observed that histological grade is an independent prognostic variable, but also that this role is ascribable only to the number of mitotic figures. In conclusion, due to the ever smaller size of diagnosed breast cancers, resulting in less cancer tissue for biofunctional and molecular analysis, mitotic count evaluated under strict quality control conditions seems to be an accurate and feasible prognostic variable.  相似文献   
9.
OBJECTIVES--To assess and quantify the occurrence of pleural malignant mesotheliomas in people who neither experienced occupational exposure to asbestos nor were married to (or known to live with) workers exposed to asbestos in the workplace. The study was conducted in the area of the local health authority of Casale Monferrato, in north western Italy, where a large factory that produced asbestos cement was active up to 1985. No other major activities related to asbestos have ever been present in the area. METHODS--A retrospective survey covering the period 1980 to 1991 identified 126 incident pleural malignant mesotheliomas histologically diagnosed among residents in the local health authority (population at the 1981 census 98,000). Submission of 83 of 95 cases diagnosed during 1980-9 for revision by a panel of five expert pathologists led to the exclusion of 21. The 31 cases diagnosed in 1990-1 were not submitted for revision. For 64 of the 105 retained cases, information derived from different sources (rosters of the employees in the asbestos cement factory dated back to 1907, list of their spouses, clinical records) did not suggest occupational or paraoccupational exposure to asbestos. RESULTS--Incidence excludes cases for which there was some suggestion of occupational or paraoccupational exposure to asbestos. Incidence of histologically confirmed malignant mesothelioma among residents in the local health authority (annual x 100,000; age adjusted) was 4.2 in men and 2.3 in women (based on 26 and 18 cases respectively). In both sexes, rates in 1985-9 were higher than in the previous quinquennium. Corresponding estimates for 1990-1 (based on unrevised diagnoses) suggest similar rates in men and women. CONCLUSION--Rate ratios which are four to six times those measured by conventional Italian cancer registries can hardly be totally explained by bias produced by lack of recognition of occupational or paraoccupational exposure. The problem of proving this type of negative data is common to other circumstances of alleged cancer clusters of environmental (non occupational) origin.  相似文献   
10.
Familial amyloidotic polyneuropathy (FAP) is an inherited disease characterized by an abnormal systemic deposition of a mutant protein called transthyretin (TTR) with elective involvement of the peripheral nervous system, but often determining cardiac, gastrointestinal, and urinary tract dysfunction. FAP commonly affects the liver and the heart until end-organs failure. Transthyretin amyloidosis is today an accepted indication for orthotopic liver transplantation (OLT). Combined heart and liver transplantation (CHLT) may be an attractive and rational treatment option when both organs are contemporary involved by this type of amyloidotic disease. Nowadays, surgical indications and techniques are far from being consolidated because only few cases of CHLT have been previously reported in literature. From November 1999 to May 2006, we performed five orthotopic combined heart and liver transplantations for FAP at our institution. Our surgical experience and clinical outcomes are herein reported.  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