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   209193篇
  免费   18127篇
  国内免费   4489篇
耳鼻咽喉   3255篇
儿科学   4074篇
妇产科学   3564篇
基础医学   16565篇
口腔科学   7180篇
临床医学   19235篇
内科学   19993篇
皮肤病学   2385篇
神经病学   10295篇
特种医学   5671篇
外国民族医学   11篇
外科学   20276篇
综合类   33241篇
现状与发展   9篇
一般理论   24篇
预防医学   28410篇
眼科学   1985篇
药学   20201篇
  344篇
中国医学   26066篇
肿瘤学   9025篇
  2024年   949篇
  2023年   4203篇
  2022年   7888篇
  2021年   10377篇
  2020年   10132篇
  2019年   11585篇
  2018年   10080篇
  2017年   8637篇
  2016年   7694篇
  2015年   7149篇
  2014年   14072篇
  2013年   14326篇
  2012年   12596篇
  2011年   13465篇
  2010年   10855篇
  2009年   9361篇
  2008年   8671篇
  2007年   8753篇
  2006年   7439篇
  2005年   6283篇
  2004年   5214篇
  2003年   4648篇
  2002年   3583篇
  2001年   2974篇
  2000年   2643篇
  1999年   2155篇
  1998年   1722篇
  1997年   1547篇
  1996年   1253篇
  1995年   1196篇
  1994年   1091篇
  1993年   969篇
  1992年   882篇
  1991年   807篇
  1990年   705篇
  1989年   682篇
  1988年   634篇
  1987年   571篇
  1986年   522篇
  1985年   1777篇
  1984年   2054篇
  1983年   1290篇
  1982年   1705篇
  1981年   1183篇
  1980年   1011篇
  1979年   905篇
  1978年   736篇
  1977年   554篇
  1976年   695篇
  1975年   477篇
排序方式: 共有10000条查询结果,搜索用时 20 毫秒
61.
Serum IgA and IgG functional antibodies and their subclasses to Streptococcus pneumoniae capsular antigen found in two aged‐matched cohorts of children with and without otitis media with effusion The relationship between acute otitis media and otitis media with effusion (OME) is uncertain and the aetiology of OME is multifactorial. Otitis media with effusion may be an inflammatory condition; both bacteria and viral infections could play a part in this inflammation. The four bacteria Streptococcus pneumoniae, Haemophilus influenza, Staphylococcus aureus and Branhamella catarrhalis cause 60% of the infections whereas S. pneumoniae accounts for up to 35%. IgA provides the dominant surface response to polysaccharide and lipopolysaccharide antigens, of which IgA2 is the main subclass. Once the mucosa has been breached, most protection is provided by IgG. IgG2 acts mainly against bacterial capsular antigens. This study looked at two groups of 50 children with and without OME who were aged between 3 and 10 years. The aims were to determine if, firstly, the levels of the serum immunoglobulins were different in the two groups, secondly whether these children made the appropriate antibody response to the capsular antigen to S. pneumoniae (PCP), and finally if there was a delay in the maturity of the IgA response. The total IgG, IgA and all subclass levels were measured using radial immunodiffusion. Levels of functional IgA and IgG were measured using ELISAs (25 patients in each group). The results were analysed with non‐parametric tests. The immunoglobulin levels were within the normal levels for both groups. There were very good correlations between the IgG total anti‐PCP and the IgG2 anti‐PCP (R > 0.9, p = 0.001). There was a good correlation between the levels of both IgG total and IgG2 anti‐PCP against IgA total anti‐PCP in both groups (R > 0.85, p > 0.01). This confirms a normal antibody response between both groups of patients. The ages of the controls and patients (50 samples) were correlated with increasing titres of circulating functional antibodies (P = 0.001). This is highly suggestive of a normal age‐related response. In conclusion, the findings were contradictory to our original hypothesis that there is a subtle difference in surface protection between children with and without OME. We believe that a previous history of recurrent acute otitis media is unrelated to the development of OME after 3 years of age.  相似文献   
62.
Results are reported on the regioselective C‐deuteriation of a series of enolates derived from the deprotonation of aryl alkyl ketones using dilithiated urea as the pro‐base in the presence of a suitable deuterium donor. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
63.
Systemic lupus erythematosus (SLE) is the archetypical immunologic disease. Approximately 20% of patients present in the first two decades of life. This article highlights some of the differences between pediatric and adult onset lupus.Children are defined as different from adults on the basis of age. Lupus presents with different gender ratios based on hormonal or pubertal status with more significant skewing toward female patients in the childbearing years. Female patients in the childbearing years appear to have a higher relative risk for mortality. Despite this, children have greater disease severity at onset based on the number of patients who present with significant organ inflammation, the amount of corticosteroids required and the abnormalities in lupus serologies including autoantibodies and low complements. Children present frequently with congenital and acquired complement defects. Children have an increased risk of infections that can be confused with lupus. They have a higher risk of serious pneumococcal infection and may have less protection from vaccinations received at the time of disease onset.The clinical immunology laboratory is critical in the diagnosis and treatment of pediatric SLE. The rapid analysis and transfer of laboratory results can be life saving for the child with suspected new onset lupus. The laboratory is also helpful in determining disease activity through analysis of immunologic trends over time in pediatric lupus patients. This is especially important in the noncompliant adolescent patient who has a correlation between disease activity and lupus serologic tests. Finally, the clinical immunology laboratory is an important tool for better understanding of the immunologic phenomena associated with lupus and of disease pathophysiology.  相似文献   
64.
65.
目的 :探讨单纯疱疹性角膜炎是中西医联合用药的治疗方法。方法 :本组 10 0例 ( 10 6只眼 )单纯疱疹性角膜炎患者应用抗病毒药物联合清热解毒中药的疗效观察。结果 :本组病例治疗后总有效率 82 .0 8%。结论 :中西医联合治疗措施是我们对单纯疱疹性角膜炎治疗的一项新的探讨。  相似文献   
66.
目的:观察盐酸托烷思琼对预防脑动脉瘤栓塞术患者术后恶心呕吐(PONV)的有效性和安全性。方法:选择行颅内动脉瘤栓塞术患者45例,随机分为3组,每组15例,于手术结束前30分钟A组患者缓慢静注盐酸托烷思琼5mg,B组患者缓慢静注盐酸托烷思琼3mg,C组患者给予生理盐水。术后观察并记录以下指标:(1)术后24h内恶心呕吐发生率及强度;(2)术后2、8h镇静评分(OAA/S);(3)术后2、8h平均动脉压(MAP),心率(HR);(4)各组不良反应的发生情况。结果:术后24h内两治疗组恶心呕吐发生率显著低于对照组,差异有统计学意义(P<0.05或P<0.01)。托烷思琼5mg组恶心呕吐发生率略低于3mg组,但差异无统计学意义(P>0.05)。结论:托烷思琼可降低脑动脉瘤栓塞术患者术后恶心呕吐的发生率。托烷思琼3mg不仅可以减少药物用量,而且能减少副作用的发生,是一种经济、有效、安全的止吐方法。  相似文献   
67.
The pathogenesis and etiology of Kawasaki disease are unknown, but some studies suggest increased genetic susceptibility. The case is presented of an infant with Kawasaki disease whose father suffered from the same illness 21 years previously. The A, B and C loci of the HLA antigens were examined.  相似文献   
68.
69.
Both systemic and local therapy, for conditions of the breast and unrelated to it, may produce manuno-graphic changes. Some of these are characteristic, such as the pattern of scarring seen in reduction mammo-plasty. In many other instances, however, the changes produced overlap features commonly seen in malignancy. A knowledge of the timing, natural history and spectrum of these changes will aid mammographic interpretation.  相似文献   
70.
The referral pattern of 140 Dutch patients with oral mucosal lesions, who had been referred to a Department of Oral & Maxillofacial Surgery and Oral Pathology, shows that patients with oral mucosal lesions consult the dentist as often as the family doctor as the first source of help or information. Furthermore, family doctors were much more used to refer patients with oral mucosal disease to medical specialists rather than to the dentist or the oral and maxillofacial surgeon.  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