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   2125篇
  免费   194篇
  国内免费   24篇
耳鼻咽喉   34篇
儿科学   25篇
妇产科学   6篇
基础医学   195篇
口腔科学   1327篇
临床医学   93篇
内科学   173篇
皮肤病学   15篇
神经病学   52篇
特种医学   13篇
外科学   44篇
综合类   114篇
预防医学   76篇
药学   125篇
中国医学   20篇
肿瘤学   31篇
  2024年   6篇
  2023年   26篇
  2022年   43篇
  2021年   65篇
  2020年   89篇
  2019年   64篇
  2018年   77篇
  2017年   64篇
  2016年   84篇
  2015年   75篇
  2014年   85篇
  2013年   129篇
  2012年   99篇
  2011年   97篇
  2010年   71篇
  2009年   91篇
  2008年   60篇
  2007年   71篇
  2006年   65篇
  2005年   59篇
  2004年   60篇
  2003年   57篇
  2002年   81篇
  2001年   47篇
  2000年   40篇
  1999年   39篇
  1998年   35篇
  1997年   50篇
  1996年   47篇
  1995年   37篇
  1994年   39篇
  1993年   32篇
  1992年   54篇
  1991年   35篇
  1990年   27篇
  1989年   24篇
  1988年   22篇
  1987年   24篇
  1986年   23篇
  1985年   20篇
  1984年   22篇
  1983年   16篇
  1982年   6篇
  1981年   17篇
  1980年   11篇
  1979年   9篇
  1978年   7篇
  1977年   16篇
  1976年   9篇
  1975年   6篇
排序方式: 共有2343条查询结果,搜索用时 15 毫秒
81.
西吡氯铵含漱液对单纯性牙龈炎患者口腔细菌的抑制作用   总被引:2,自引:0,他引:2  
目的 :观察 1mL/L西吡氯铵含漱液对单纯性牙龈炎患者牙菌斑和唾液中细菌的抑制作用。方法 :纳入单纯性牙龈炎患者 48例 ,用随机双盲法分为 2组 ,分别给予 1mL/L西吡氯铵含漱液或爱诺天健含漱液 (主要成分也是 1mL/L西吡氯铵 )。患者使用含漱液漱口 ,每天 5次 ,晨起、睡前、饭后各 1次 ,每次含 15mL ,持续漱口 6 0s,7d为一疗程。就诊当天和第 8天测定患者牙菌斑和唾液中 11种常见细菌的菌株数和细菌的数量。结果 :实验组和对照组各 2 4例 ,年龄、性别、吸烟史分布无组间差异 (P >0 .0 5 ) ,首次检查牙菌斑、唾液中常见细菌检出率和平均检出量组间比较 ,无显著差异 (P >0 .0 5 )。终点检查牙菌斑、唾液中细菌总量在治疗组与对照组比首次检查 ,均显著减少 (P <0 .0 5 ) ,组间比较细菌数量无显著性差异 (P >0 .0 5 )。治疗组与对照组细菌总量的减少主要是由可疑病原菌量减少所致。治疗前后白色念珠菌检出率和检出量无变化 (P >0 .0 5 )。结论 :1mL/L西吡氯铵含漱液可显著减少单纯性牙龈炎患者牙菌斑、唾液中细菌的种类和数量 ,不导致口腔菌群失调。  相似文献   
82.
Antibacterial activity of silver inorganic agent YDA filler   总被引:17,自引:0,他引:17  
YDA filler is an antibacterial agent that is currently in commercial dental use. In this study, we attempted to determine whether it exerts an antibacterial effect on human saliva bacteria, and to determine whether it can be used in dental materials. CFUs in 1 mL stimulated human saliva were examined using blood agar and mitis salivarius agar after immersion, with or without YDA filler. The antibacterial effect was compared with that of Ketac-Silver. Dental materials containing 5% wt YDA filler were prepared for in vitro testing on S. mutans and A. viscosus. Furthermore, we examined the in vitro cytotoxicity of experimental MMA resin containing YDA filler on HeLa cells. Human saliva bacteria and mutans streptococci showed reduced viability following exposure to YDA filler after 12 h. The concentration of silver ions released by YDA filler was below 1 ppm after 12 h. Two tested strains showed reduced viability following exposure to dental materials containing YDA filler. In another experiment, MMA resin containing YDA filler did not show cytotoxicity on HeLa cells after 24- and 48-h exposure. Thus, YDA filler may help in the development of antibacterial dental materials, such as composite resin, glass-ionomer or temporary cement.  相似文献   
83.
84.
85.
86.
Introduction: Current studies show that, even in the era of antiretroviral therapies, HIV-1 infection is associated with more severe and frequent refractory chronic periodontitis.

Areas covered: This review, based on a systematic analysis of the literature, intends to provide an update on factors that may be involved in the pathogenesis of periodontal disease in HIV-1-infected patients, including local immunosuppression, oral microbial factors, systemic inflammation, salivary markers, and the role of gingival tissue as a possible reservoir of HIV-1.

Expert commentary: The therapeutic revolution of ART made HIV-1 infection a chronic controllable disease, reduced HIV-1 mortality rate, restored at least partially the immune response and dramatically increased life expectancy of HIV-1-infected patients. Despite all these positive aspects, chronic periodontitis assumes an important role in the HIV-1 infection status for activating systemic inflammation favoring viral replication and influencing HIV-1 status, and also acting as a possible reservoir of HIV-1. All these issues still need to be clarified and validated, but have important clinical implications that certainly will benefit the diagnosis and management of chronic periodontitis in HIV-1-infected patients, and also contributes to HIV-1 eradication.  相似文献   

87.
Parotid salivary flow was recorded from eight fit and healthy subjects using modified Lashley cups connected to an instantaneous flow meter in response to gustatory stimuli. The gustatory stimuli were monosodium glutamate (MSG), sodium chloride, sucrose, magnesium sulphate and citric acid. Stimuli were applied for 30 s, and repeated after the flows had returned to baseline following the rinse. Subjects were a significant source of variation for salivary response to each different test stimuli (p<0.001). The normalised salivary flow showed a strong correlation to concentration for all test stimuli (p<0.0001). The parotid salivary flow to MSG (umami) showed a dose-dependant response in which both Na(+) and glutamate ions contributed. The overall order of relative salivary flow responses from highest to lowest flows was citric acid (sour)>MSG (umami)>NaCl (salt)>sucrose (sweet)>=magnesium sulphate (bitter). The relative responses of the peak salivary flows showed the same ordered relation. The peak salivary flow provided a greater contribution to the response to citric acid, NaCl and MSG compared to the response to sucrose and magnesium sulphate.  相似文献   
88.
Salivary content of melatonin and parameters of the immune status were studied in young healthy individuals. Morning and evening levels of melatonin showed different correlations with some immunity parameters. It was assumed that the degree and type of correlation between the immune system and melatonin depend on the phase of circadian cycle, which should be considered during evaluation of immunoendocrine status.  相似文献   
89.
To cite this article: Sandin A, Björkstén B, Böttcher MF, Englund E, Jenmalm MC, Bråbäck L. High salivary secretory IgA antibody levels are associated with less late‐onset wheezing in IgE‐sensitized infants. Pediatr Allergy Immunol 2011; 22 : 477–481. Low levels of secretory IgA (SIgA) and transient IgA deficiency have been associated with an increased risk for allergy, but data are conflicting. The aim was to assess the relationship between salivary SIgA antibody levels at 1 yr and wheezing at age four in a birth cohort, in particular the possible protective role of salivary SIgA in sensitized children. Saliva samples were obtained from all children (n = 67) with a positive skin prick test (SPT) at 1 yr and 212 children with a negative SPT. In all, 200 of these children responded to questionnaires at 4 yrs and 183 were skin prick tested at that age. The levels of salivary SIgA and salivary IgA antibodies to the most common food allergen egg and inhalant allergen cat were analyzed by ELISA. Serum was analyzed for IgE antibodies to egg and cat. Development of late‐onset wheezing was associated with low SIgA levels in children with positive SPT to at least one allergen both at 1 and 4 yrs of age (p = 0.04), as well as in children with circulating IgE antibodies to egg or cat at 1 yr (p = 0.02). None of nine persistently sensitized children with SIgA levels in the upper quartile developed wheezing, when compared to 10/20 children with lower levels (p = 0.01). Older siblings, more than three infections during infancy, at least one smoking parent, and male gender, were all associated with SIgA in the upper quartile. In conclusion, high levels of SIgA antibodies in sensitized infants were associated with significantly less late‐onset wheezing, supporting a protective role against development of asthmatic symptoms. Recurrent infections and other factors supporting an increased microbial pressure during infancy were associated with high levels of salivary SIgA.  相似文献   
90.
Paired sera and parotid saliva from 75 HIV-1-infected patients, divided in three equal groups with CD4+ cell counts > 500, 200–500 and < 200/mm3, respectively, were analysed for IgG, IgA and secretory IgA (sIgA) concentrations and for IgG and IgA antibody directed to HIV-1. Twenty-nine age-matched HIV subjects were used as controls. In serum the concentrations of immunoglobulins were significantly increased in HIV-infected subjects compared with controls, and a progressive increase of IgA and sIgA was noticed while the CD4+ cell count decreased. In contrast, concentrations of IgA and sIgA were not different in parotid saliva between the four subject groups. By an ELISA test directed towards HIV-1 proteins, 73 of the 75 serum specimens from the HIV-infected subjects (97%) and 43 of the corresponding saliva (57%) were found positive for specific IgA antibodies to HIV-1, with an even distribution among the three groups of patients. By Western blotting multiple specificities of IgA to HIV-1 proteins were not frequently found in patients. By contrast, in spite of an IgG concentration in saliva about 100 times lower than that of IgA, reactivities were significantly higher for IgG than for IgA antibodies, especially to env and to pol HIV-1 products. Altogether, these data suggest that the regulation of IgA production in HIV-infected subjects is independent in serum and in parotid saliva. This imbalance of IgA/IgG antibodies to HIV-1 at the mucosal level appears to be a specific feature of HIV-1 infection, and may raise important issues in terms of local protection after immunization.  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