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   215635篇
  免费   53096篇
  国内免费   8580篇
耳鼻咽喉   2517篇
儿科学   5925篇
妇产科学   2084篇
基础医学   36158篇
口腔科学   7369篇
临床医学   28994篇
内科学   41751篇
皮肤病学   8811篇
神经病学   19425篇
特种医学   7016篇
外国民族医学   65篇
外科学   26626篇
综合类   23554篇
现状与发展   29篇
一般理论   34篇
预防医学   14042篇
眼科学   4629篇
药学   21635篇
  121篇
中国医学   8783篇
肿瘤学   17743篇
  2024年   575篇
  2023年   2270篇
  2022年   5817篇
  2021年   8489篇
  2020年   10045篇
  2019年   14928篇
  2018年   14522篇
  2017年   15463篇
  2016年   15876篇
  2015年   17679篇
  2014年   19075篇
  2013年   19232篇
  2012年   14424篇
  2011年   15011篇
  2010年   16380篇
  2009年   11335篇
  2008年   9575篇
  2007年   8462篇
  2006年   7808篇
  2005年   6911篇
  2004年   5533篇
  2003年   5436篇
  2002年   4807篇
  2001年   4177篇
  2000年   3631篇
  1999年   2861篇
  1998年   1685篇
  1997年   1807篇
  1996年   1270篇
  1995年   1205篇
  1994年   1100篇
  1993年   775篇
  1992年   995篇
  1991年   900篇
  1990年   800篇
  1989年   745篇
  1988年   659篇
  1987年   572篇
  1986年   531篇
  1985年   428篇
  1984年   375篇
  1983年   310篇
  1982年   270篇
  1981年   234篇
  1980年   199篇
  1979年   199篇
  1978年   194篇
  1977年   214篇
  1976年   191篇
  1974年   156篇
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
71.

Background  

Bortezomib, a proteasome-specific inhibitor, has emerged as a promising cancer therapeutic agent. However, development of resistance to bortezomib may pose a challenge to effective anticancer therapy. Therefore, characterization of cellular mechanisms involved in bortezomib resistance and development of effective strategies to overcome this resistance represent important steps in the advancement of bortezomib-mediated cancer therapy.  相似文献   
72.
郁沁 《卫生职业教育》2009,27(18):59-60
卫生保健课程是以贯彻"预防为主"的方针、实现"健康为人人,人人为健康"的一门重要学科。笔者根据数年的教学实践,结合学生的课堂调查结果,总结卫生保健课程教学中常见的误区,以期同行在教学中避免走进误区,更好地为教学服务。  相似文献   
73.
74.
1 The internal anal sphincter (IAS) has a spontaneous tone and is the main contributor to the maintenance of faecal continence. The spontaneous resting tone exhibited by the sphincter can be modified by neurotransmitters from the autonomic and enteric nervous systems. 2 In this review, the influence of the sympathetic and parasympathetic nervous systems on IAS tone are discussed and the putative roles of nitric oxide, carbon monoxide, vasoactive intestinal peptide and adenosine triphosphate in non‐adrenergic non‐cholinergic transmission are considered. 3 Faecal incontinence is a common condition that places a heavy financial burden on the health service and severely affects patients’ quality of life. Resting anal pressure is reduced in patients with faecal incontinence and agents that increase sphincter tone tend to relieve symptoms. The results of clinical studies of the use of phenylephrine to treat faecal incontinence are reviewed. 4 It is concluded that the IAS is a potential target for drug development for the treatment of faecal incontinence.  相似文献   
75.
76.
目的 评价诊断中老年男子部分雄激素缺乏综合征(PADAM)的游离睾酮指数(FTI).方法 对129例45岁以上健康男性的FTI进行年龄相关分析.以推算的游离睾酮(CFT)值为依据,对FTI进行有效性检验.结果 男子在中老年期FTI与增龄呈明显的负相关.FTI敏感性97.78%,特异性58.33%.结论 计算简单的FTI可用于PADAM病人的筛选和随访,尤其对70岁以上男子是血清FT较为有效的参数.  相似文献   
77.
Purpose Parathyroid carcinoma (PC) is rare and accounts for less than 1% of all cases of primary hyperparathyroidism (PHPT). The definitive histopathologic diagnosis of PC requires unequivocal invasion or metastasis which may be absent at first presentation. As a result, many cases of PC can only be diagnosed retrospectively. Parafibromin is the protein encoded by HRPT2 which is mutated and not expressed in many parathyroid carcinomas. Given that PCs generally weigh more than parathyroid adenomas (PA)s, we hypothesized that amongst large PAs there may be a high incidence of occult PC which could be identified by negative staining for parafibromin. Methodology 57 parathyroid glands weighing greater than 2 grams excised from 1998–2006 were identified from the University of Sydney Endocrine Surgical Database. Two specimens with a histopathologic diagnosis of PC were excluded. Immunohistochemical staining for parafibromin was performed on the remaining 55 PAs. Results Of the 55 specimens stained for parafibromin only one definite negative stain was detected. This case was originally classified as an “atypical adenoma” because it showed nuclear and architectural atypia without unequivocal evidence of invasive growth. In view of the negative staining for parafibromin it therefore probably represents occult carcinoma. There has been no evidence of recurrence or metastasis after 6.5 years. Conclusions Complete loss of staining for parafibromin is very rare in giant parathyroid adenomas suggesting that occult carcinoma is equally rare. As a result routine immunohistochemical staining for parafibromin does not appear to be an effective screening test for carcinoma in large PA without histopathologic features of PC.  相似文献   
78.
Purpose To demonstrate that laparoscopic adjustable gastric banding may promote oesophageal dilatation or interfere with oesophageal motility. Methodology We report a case of a 67 year old female with a complex medical history who developed secondary achalasia from a slipped laparoscopic adjustable gastric band for weight loss. This led to recurring episodes of aspiration pneumonia requiring multiple admissions at North Shore Hospital, Auckland, New Zealand. Results A decision was made to remove the gastric band, five years after its initial insertion. At one month follow up, she was swallowing normally and oesophageal manometry had returned to normal. Conclusion Oesophageal dysmotility is sometimes seen in patients who have bands that are adjusted too tightly or in whom the band has slipped. This can lead to serious complications if unrecognized and incorrectly treated. Oesophageal symptoms in patients with adjustable bands must be considered secondary to the band until proven otherwise ie removal of the band or complete deflation.  相似文献   
79.
Administration of cholinotoxin etylcholine aziridinium (AF64A) into the brain selectively induces nonrever-sible cholinergic deficit. Wistar rats were injected intracerebroventricularly bilaterally with AF64A at doses of 1–3 nmol/ventricle. 28 days later the number of neurons survived was counted in dorsolateral, intermediate and medial groups of cells of the medial septum. AF64A induced a decrease in neuronal density and expression of cholineacetyl transferase at all doses used as well as in all regions studied. Brain sections were also stained for NADPH-diaphorase representing neuronal NO-synthase. Effects of AF64A on NADPH-diaphorase expression depended on the region studied. The number of NADPH-diaphorase-positive cells increased in the medial cellular group where more cholineacetly transferase-positive cells survived. In contrast, decrease in NADPH-diaphorase expression in the dorsolateral group of cells coincided with low level of cholineacetyltransferase-po-sitive neurons. The data presented suggest that in the AF64A-dependent model of neurodegeneration NO may play a neuroprotective function.  相似文献   
80.
余军 《现代医院》2005,5(12):152-153
在管理期刊工作的实践中,探讨如何提高期刊利用率的策略,根据馆情,利用现代科技手段为读者提供高质量的信息服务。  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