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   34179篇
  免费   4315篇
  国内免费   426篇
耳鼻咽喉   571篇
儿科学   6493篇
妇产科学   235篇
基础医学   2654篇
口腔科学   1083篇
临床医学   3790篇
内科学   3322篇
皮肤病学   425篇
神经病学   1663篇
特种医学   488篇
外科学   1875篇
综合类   3794篇
现状与发展   2篇
一般理论   2篇
预防医学   7642篇
眼科学   972篇
药学   2546篇
  35篇
中国医学   772篇
肿瘤学   556篇
  2024年   146篇
  2023年   702篇
  2022年   1144篇
  2021年   1612篇
  2020年   1636篇
  2019年   1356篇
  2018年   1234篇
  2017年   1438篇
  2016年   1574篇
  2015年   1314篇
  2014年   2148篇
  2013年   3023篇
  2012年   2020篇
  2011年   2154篇
  2010年   1778篇
  2009年   1586篇
  2008年   1516篇
  2007年   1620篇
  2006年   1429篇
  2005年   1290篇
  2004年   1078篇
  2003年   864篇
  2002年   800篇
  2001年   675篇
  2000年   513篇
  1999年   435篇
  1998年   484篇
  1997年   423篇
  1996年   372篇
  1995年   290篇
  1994年   295篇
  1993年   233篇
  1992年   177篇
  1991年   180篇
  1990年   161篇
  1989年   156篇
  1988年   130篇
  1987年   98篇
  1986年   130篇
  1985年   97篇
  1984年   74篇
  1983年   73篇
  1982年   57篇
  1981年   56篇
  1980年   55篇
  1979年   48篇
  1978年   36篇
  1977年   33篇
  1976年   53篇
  1973年   24篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
Abstract –  The main objective of this study was to assess the epidemiology of traumatic dental injuries (TDI) to the primary teeth of preschool children and second, to investigate whether TDI were related to anterior open bite and, third, whether TDI are related to socio-economic circumstances in an urban Brazilian population. A clinical examination was performed during the National Day of Children's Vaccination. TDI were classified according to the modified classification proposed by Ellis. In addition to those criteria the presence of tooth discoloration was recorded. An interview was carried out with mothers or guardians. The data collected included mother's level of education and living conditions. The prevalence of TDI was 9.4%. The maxillary central incisors were the most affected teeth. Most children with a TDI experienced traumatic injuries to one tooth (6.3%), while 2.8% had two and 0.4% had three traumatized teeth. The most common crown fracture was in enamel only (68.8%), followed by crown fracture of enamel and dentin (13.8%). Missing teeth following trauma occurred in 10.9% of those with TDI. The prevalence of tooth discoloration was 5.1%. Children with anterior open bite had twice the level the level of TDI compared to those with normal occlusions ( P  = 0.001). Socio-economic factors were not statistically significantly associated with the occurrence of TDI. The prevalence of dental injuries in Brazilian preschool children was low. Children with anterior open bite experienced more dental injuries. Neither of the indicators of socio-economic status was related to the prevalence of TDI.  相似文献   
122.
Systemic acute rhinosinusitis therapy consists mostly of antibiotic treatment because pathogens play a major role. Amoxicillin is the drug of choice for treatment of acute rhinosinusitis, with second- and third- generation cephalosporins, azythromycin, clarithromycin, and telithromycin as possible options, especially in the case of allergy to amoxicillin. If the clinical course suggests that an anaerobic pathogen is more likely, clindamycin or metronidazole can be considered in combination with a broad-spectrum drug. In antimicrobial treatment of chronic sinusitis there is no consensus on treatment length, organism coverage, or which antibiotics are most effective because the bacteriology is variable with polymicrobial anaerobic and aerobic organisms present. Adjuvant therapies need to be proven by additional studies. Chronic rhinosinusitis is heterogeneous and treatment should vary according to the causative factor involved. Short courses of systemic steroids have been found very useful to decrease mucosal swelling and inflammation in chronic rhinosinusitis. However, no randomized controlled studies have been performed to validate their efficacy in children. A variety of other agents are used in the treatment of chronic rhinosinusitis including antihistamines, decongestants, and leukotriene modifiers. To date, there is no good evidence from randomized controlled studies to support the use of any of these agents in the treatment of this disease in either children or adults.  相似文献   
123.
Uncertainties remain as to whether breastfeeding is protective against childhood allergic disorders. Positive relationships of breastfeeding with asthma and atopic eczema were observed in two previous Japanese studies. This cross-sectional study investigated the association between the feeding pattern after birth and the prevalence of allergic disorders during the past 12 months in Japanese schoolchildren. Study subjects were 24,077 children aged 6-15 yr in Okinawa. The outcomes were based on diagnostic criteria from the International Study of Asthma and Allergies in Childhood. Allowance was made for age, sex, number of siblings, smoking in the household, paternal and maternal history of asthma, atopic eczema, and allergic rhinitis, and paternal and maternal educational level. Breastfeeding, regardless of exclusivity, for 13 months or longer and exclusive breastfeeding for 4-11 months were independently associated with a higher prevalence of atopic eczema, particularly among children without a parental allergic history. A clear positive dose-response relationship was observed between prolonged duration of breastfeeding, regardless of exclusivity, but not exclusive breastfeeding, and the prevalence of atopic eczema. We found a significant positive trend for atopic eczema across the three categories (formula milk, partial and exclusive breastfeeding) in the first 4 months of life although the odds ratio for exclusive breastfeeding was not statistically significant. No material association was found between the feeding pattern after birth and the prevalence of wheeze or allergic rhinoconjunctivitis. Prolonged breastfeeding may be associated with a higher prevalence of atopic eczema in Japanese children.  相似文献   
124.
目的 探讨高频超声检测小儿腹股沟斜疝腹股沟管扩张程度对于选择手术方式的价值。 方法 回顾分析 4 88例施行单纯疝囊高位结扎手术的小儿腹股沟斜疝超声检测的腹股沟管扩张最大内径 ,分组追踪其术后斜疝复发率。 结果 腹股沟管扩张最大内径 >1.5 cm的一组病例术后复发率明显增高。 结论 高频超声检测腹股沟管扩张最大内径 >1.5 cm的小儿腹股沟斜疝有必要行斜疝修补术 ,减少复发率 ,为临床医师提供有价值的客观指标  相似文献   
125.
126.
127.
ABSTRACT. In a well defined geographical area a total of 1590 accidents related to home products in children 0–15 years of age were prospectively registered. The incidence of product-related accidents was 279 per 10 000 children per year. A higher incidence in boys and a decreasing incidence of accidents with age was found. The most common localization of lesions was upper extremities 41% and face and skull 30%. In children 0–4 years of age household and child furniture, constructional features of the house and corrosives, hot liquids and heating equipment were the most common products causing accidents, whereas in children 5–15 years of age playthings and sports equipment as well as constructional features of the house were involved in a higher percentage of accidents.  相似文献   
128.
儿童甲状腺癌13例临床分析   总被引:1,自引:0,他引:1  
本文报告1985-1994年收治的儿童甲状腺癌13例。年龄7-16岁。男3岁,女10例。所有病例无不适,而以颈部肿物就诊。除1例根治术前未做过任何治疗外,其余病例均曾进行过不恰当治疗,颈淋巴结转移10例,肺转移3例,骨转移1例。病理诊断:乳头状癌10例,滤泡癌3例。手术以患侧腺叶及峡部切除或加健侧大部分切除为佳。如有颈淋巴结转移应同时行颈部清扫术。本文对儿童甲状腺癌的特征、误诊原因及其治疗进行了计  相似文献   
129.
为了解幼儿的肝功能和HBsAg携带情况,我们于1991年肝炎发病高峰季节对我县四所幼儿园共824名幼儿进行了ALT、TTT、ZnTT、HBsAg检测。结果ALT、TTT均升高1例,有体征;ALT单项升高6例,无症状;HBsAg阳性58例,其中9例ALT升高,4例TTT升高。幼儿园是幼儿集中的地方、同吃、同住、接触密切,对HBsAg阴性者接种乙肝疫苗,对ALT升高者不能忽视以免发生肝炎流行。  相似文献   
130.
菏泽市城区1008名学龄儿童感觉统合失调调查分析   总被引:5,自引:0,他引:5  
目的:为了解本市的学龄儿童感觉统合失调的发生率及造成感觉统合失调的有关因素。方法:采用北京感觉统合失调评定表,对6-10岁1008名在校儿童进行整群抽样调查,所获数据经χ^2检验。结果:感觉统合失调发生率为35.52%,其中轻率23.4%,重度12.1%,男童发生率为43.08%,女童发生率为27.89%,男高于女(P<0.05)。结论:儿童感觉统合失调发生率与父母文化程度、儿童自身智力、学习成绩、出生时缺氧缺血性脑病有关,有关部门要迅速组建机构对感觉统合失调进行训练。  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