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   454657篇
  免费   82367篇
  国内免费   16786篇
耳鼻咽喉   7787篇
儿科学   11888篇
妇产科学   7866篇
基础医学   45865篇
口腔科学   10424篇
临床医学   66935篇
内科学   104624篇
皮肤病学   16449篇
神经病学   38137篇
特种医学   16451篇
外国民族医学   96篇
外科学   77670篇
综合类   34375篇
现状与发展   117篇
一般理论   69篇
预防医学   25361篇
眼科学   11098篇
药学   30060篇
  164篇
中国医学   11877篇
肿瘤学   36497篇
  2024年   1360篇
  2023年   7998篇
  2022年   9852篇
  2021年   15536篇
  2020年   18758篇
  2019年   19600篇
  2018年   22861篇
  2017年   23122篇
  2016年   24311篇
  2015年   27645篇
  2014年   37092篇
  2013年   36990篇
  2012年   26106篇
  2011年   27885篇
  2010年   28968篇
  2009年   27286篇
  2008年   19972篇
  2007年   17453篇
  2006年   19579篇
  2005年   16711篇
  2004年   12212篇
  2003年   10237篇
  2002年   9365篇
  2001年   10553篇
  2000年   9816篇
  1999年   9894篇
  1998年   7305篇
  1997年   7134篇
  1996年   6163篇
  1995年   5788篇
  1994年   4186篇
  1993年   3074篇
  1992年   3722篇
  1991年   3458篇
  1990年   2760篇
  1989年   2676篇
  1988年   2307篇
  1987年   2056篇
  1986年   1869篇
  1985年   1492篇
  1984年   1062篇
  1983年   929篇
  1982年   761篇
  1981年   620篇
  1980年   557篇
  1979年   568篇
  1978年   490篇
  1977年   524篇
  1975年   375篇
  1972年   393篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
Editorial     
  相似文献   
62.
Hirschsprung disease (HSCR) is a congenital disorder characterized by an absence of ganglion cells in the nerve plexuses of the lower digestive tract. Although mutations in eight different genes (EDNRB, EDN3, ECE1, SOX10, RET, GDNF, NTN, SIP1) have been identified in affected individuals, it is now clear that RET and EDNRB are the primary genes implicated in the etiology of HSCR. All eight genes are involved in the early development of the enteric nervous system, and most act through two distinct biochemical pathways mediated by RET and EDNRB. Mutations in RET and EDNRB account for up to 50% and 5% of HSCR cases in the general population, respectively. Interaction between these two signaling pathways could modify RET expression and, therefore, HSCR phenotype. Here, we report the case of a 1-year-old Taiwanese boy who presented with abdominal distension since birth and bilious vomiting after feeding. HSCR (short-segment type) was diagnosed based on X-ray, lower gastrointestinal series and biopsy findings. Mutation analysis revealed a heterozygous T>C missense mutation in exon 1 of the EDNRB gene, that substitutes the highly conserved cysteine-90 residue in the extracellular domain of the G protein-coupled receptor with an arginine residue (C90R). No RET gene mutation was detected in this patient.  相似文献   
63.
64.
65.
Legionella pneumophila is a common cause of sporadic community-acquired pneumonia, but culture-proven legionellosis is rarely diagnosed. There is no laboratory test for Legionnaires' disease that can detect all patients with the disease. Culture is the standard diagnostic method and should be initiated as soon as possible in suspected cases. We describe a rare case of community-acquired pneumonia caused by L. pneumophila serogroup 6. A 77-year-old man was admitted to a tertiary care hospital because of high fever, productive cough, and progressive dyspnea. Chest radiography showed bilateral pneumonia, which led to respiratory failure necessitating mechanical ventilatory support. Despite antibiotic therapy, his condition continued to deteriorate and acute renal failure also developed. Urine was negative for L. pneumophila. Culture of the sputum yielded L. pneumophila serogroup 6, although there was no elevation of the serum antibody titer. Pneumonia resolved gradually and he was extubated after treatment with levofloxacin followed by erythromycin. L. pneumophila other than serogroup 1 should be included in the differential diagnosis of patients with suspected atypical community-acquired pneumonia.  相似文献   
66.
Prostatitis and male infertility are frequent disorders, and the role of prostatitis in male infertility has been under discussion for more than 30 years. Many researchers have shown relevant links between the two. Although a causal relationship has not been definitely demonstrated, increasing evidence shows that chronic prostatitis has a relevant negative impact on male fertility potential, at least in certain subgroups. In the following review, we focus on the present state of knowledge on the role of chronic prostatitis as an etiologic factor in male infertility.  相似文献   
67.
Medical therapy is currently the most popular treatment choice for lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH). Because medical therapy of BPH-related LUTS is considered a life-long strategy, short- and long-term cost considerations should play a major role in therapeutic decision-making. The effectiveness in terms of long and short amelioration of symptoms, flow rate, and quality of life are well documented for 5α-blockers and 5α-reductase inhibitors as well as for the gold standard treatment for BPH, transurethral resection of the prostate and minimally invasive therapies. Short-and long-term safety concerns also are well documented for these various treatment options. On the contrary, short- and long-term costs have been less well studied and comparisons depend on the model or analyses undertaken in the few studies available. However, the economic studies based on prospective clinical trial data that have become available throughout the past several decades allow us to rationalize our use of α-blockers, 5α -reductase inhibitors, and combination therapy, taking into consideration age, severity of symptoms, prostate volume, prostate-specific antigen, and the differential response of the various medications (and combination) in selected patients. Based on current studies, 5α -blockers generally provide cost-effective therapy for most patients, whereas 5α-reductase therapy and combination therapy provide cost-effective treatment for patients with larger prostate glands or higher baseline prostate-specific antigen levels.  相似文献   
68.
69.
70.
Abstract: Background: Identification of risk drinking in expectant fathers may be helpful as an important part of efforts to minimize maternal alcohol use, and as an opportunity to inform them about a problematic practice during a critical developmental stage for the couple. The purpose of this study was to evaluate the T‐ACE screening questionnaire, which asks about t olerance to alcohol, being a nnoyed by other's comments about drinking, attempts to c ut down, and having a drink first thing in the morning (“ e ye‐opener”), in the male partners of pregnant women who themselves were T‐ACE positive. Methods: Two hundred fifty‐four male partners were asked to complete the T‐ACE embedded in a health survey, the Alcohol Use Disorders Identification Test (AUDIT), and other questions about their alcohol use in the past 30 days when their pregnant partners had a median gestation of 11.5 weeks (T1). After delivery, male partners again completed the T‐ACE and quantity‐frequency questions (T2). The predictive ability of the T‐ACE and AUDIT was compared, using risk drinking (>4 drinks/day or >14 drinks/week) as the criterion standard. Results: A substantial minority of male partners had risk drinking, 31 percent at T1 and 25 percent at T2. Although the AUDIT was better than the T‐ACE as an independent predictor of risk drinking, the latter was most accurate when the tolerance threshold exceeded 2 drinks, the same established for pregnant women. The sensitivity (T1 = 84.6%, T2 = 82.8%) and specificity (T1 = 43.8%, T2 = 51.1%) of the T‐ACE at this threshold compared favorably with those of the AUDIT at the standard cut point of 8. Conclusions: The T‐ACE may be a practical way for clinicians to identify risk drinking in both pregnant women and expectant fathers. (BIRTH 33:2 June 2006)  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