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   43757篇
  免费   3531篇
  国内免费   1684篇
耳鼻咽喉   263篇
儿科学   977篇
妇产科学   682篇
基础医学   5603篇
口腔科学   1151篇
临床医学   4382篇
内科学   6588篇
皮肤病学   1491篇
神经病学   2112篇
特种医学   888篇
外国民族医学   7篇
外科学   2449篇
综合类   7274篇
预防医学   2267篇
眼科学   574篇
药学   7946篇
  36篇
中国医学   2450篇
肿瘤学   1832篇
  2024年   53篇
  2023年   754篇
  2022年   1050篇
  2021年   1791篇
  2020年   1825篇
  2019年   1509篇
  2018年   1395篇
  2017年   1557篇
  2016年   1411篇
  2015年   1360篇
  2014年   2490篇
  2013年   2816篇
  2012年   2375篇
  2011年   2706篇
  2010年   2238篇
  2009年   2044篇
  2008年   2122篇
  2007年   2218篇
  2006年   1943篇
  2005年   1976篇
  2004年   1597篇
  2003年   1520篇
  2002年   1311篇
  2001年   1194篇
  2000年   1080篇
  1999年   901篇
  1998年   834篇
  1997年   725篇
  1996年   576篇
  1995年   631篇
  1994年   569篇
  1993年   393篇
  1992年   369篇
  1991年   275篇
  1990年   192篇
  1989年   143篇
  1988年   119篇
  1987年   116篇
  1986年   90篇
  1985年   111篇
  1984年   109篇
  1983年   93篇
  1982年   90篇
  1981年   76篇
  1980年   54篇
  1979年   43篇
  1978年   23篇
  1977年   35篇
  1976年   33篇
  1973年   12篇
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
1.
2.
3.
A delayed haemolytic transfusion reaction (DHTR) encompasses a positive direct antiglobulin test (DAT) developed anytime between 24 hours to 28 days after cessation of transfusion, a positive eluate or a newly identified alloantibody in the plasma or serum along with features of haemolysis in the patient. Routinely, it is expected that with the transfusion of one unit of packed red cells in a patient of average height and weight, the haemoglobin level and hematocrit increase by 1 g/dL and 3% respectively. However, in a patient with DHTR, an inadequate rise of post-transfusion haemoglobin (< 1 g/dL) or rapid fall in haemoglobin back to pre-transfusion levels is observed. Kidd antibodies are particularly known to cause DHTR, maybe alone or in unison with other antibodies. Detection of these alloantibodies is consequential in providing good transfusion support to these patients. These events may be difficult to detect as they may present as varied clinical features or immunological nuisances. In this case series, we have presented three cases of DHTR with special emphasis on their clinical presentations, immunohaematological evaluations, laboratory parameters and the role of proper transfusion support in these patients to avoid further complications.  相似文献   
4.
《Vaccine》2022,40(30):4038-4045
PurposeAs protection from COVID-19 following two doses of the BNT162b2 vaccine showed a time dependent waning, a third (booster) dose was administrated. This study aims to compare the antibody response following the third dose versus the second and to evaluate post-booster seroconversion.MethodsA prospective observational study conducted in Maccabi Healthcare Services. Serial SARS-CoV-2 Spike IgG tests, 1,2,3 and 6 months following the second vaccine dose and one month following the third were obtained. Neutralizing antibody levels were measured in a subset of participants. Per individual SARS-CoV-2 Spike IgG titer ratios were calculated one month after the booster administration compared to titers one month following the second dose and prior to booster.ResultsAmong 110 participants, 56 (51%) were women. Mean age was 61.7 ± 1.9 years and 66 (60%) were immunocompromised. One month after third dose, IgG titers were induced 7.83 (95 %CI 5.25–11.67) folds and 2.40 (95 %CI 1.90–3.03) folds compared to one month after the second, in the immunocompromised and immunocompetent groups, respectively. Of the 17 immunocompromised participants who were seronegative after the second dose, 4 (24%) became seropositive following the third. Comparing the titers prior to the third dose, an increase of 50.7 (95 %CI 32.5–79.1) fold in the immunocompromised group and 25.7 (95 %CI 19.1–34.7) fold in and immunocompetent group, was observed.ConclusionA third BNT162b2 vaccine elicited robust humoral response, superior to the response observed following the second, among immunocompetent and immunocompromised individuals.  相似文献   
5.
PurposeThe clinical manifestations of rickettsial diseases mimic other endemic infections with similar presentations thus posing a serious challenge to clinicians for their diagnosis. For the diagnosis of rickettsial disease serological tests like Weil Felix, ELISA and IFA are used. There are limited studies that have evaluated different serological tests for the diagnosis of rickettsial diseases. Therefore, the present study was undertaken to evaluate the ELISA and Weil Felix test for the diagnosis of rickettsial diseases prevalent in this region.MethodsSamples from 281 patients clinically suspected of rickettsial diseases were tested for spotted fever group (SFG), typhus group (TG) and scrub typhus group (STG) by Weil Felix, ELISA and IFA was taken as the gold standard. Baseline titers and cut-off ODs were calculated by taking samples from healthy blood donors.ResultsThe sensitivity, specificity, positive and negative predictive value of Weil Felix test ranged from 30% to 44%, 83.46%–97.86%, 9%–77%, 92–96% respectively. The sensitivity and specificity, positive and negative predictive value of ELISA ranged from 80.77% to 96.15%, 96.33%–98.43%, 70.21%–88.64%, 92.89%–99.60% respectively. Maximum cross-reactions were observed between SFG and STG by the Weil Felix test and between STG and TG by ELISA.ConclusionsELISA was found to be sensitive and specific for the diagnosis of rickettsial diseases. It is easy to perform, does not require a technical expert for result interpretation and a large number of samples can be processed at a time.  相似文献   
6.
目的 探讨丹青胶囊联合他扎罗汀倍他米松治疗银屑病的临床疗效.方法 选取2019年6月—2021年6月在天津市职业病防治院门诊皮肤科就诊治疗的114例银屑病患者,根据随机数字法分为对照组和治疗组,每组各57例.对照组患者给予他扎罗汀倍他米松乳膏,洗净患处,待皮肤干爽后,将适量本品均匀涂抹于患处,1次/d.治疗组患者在对照组治疗基础上口服丹青胶囊,4粒/次,3次/d.两组患者均连续治疗7 d.观察两组患者的临床疗效和临床症状好转时间,比较两组治疗前与治疗1、4、8周的皮损面积和严重程度指数(PASI)评分和血清炎性因子水平.结果 治疗后,治疗组总有效率是98.25%,显著高于对照组的82.46%(P<0.05).治疗后,治疗组患者皮损暗红、皮损肥厚、皮肤瘙痒、皮肤疼痛等症状好转时间均显著短于对照组(P<0.05).治疗后,两组PASI评分均较治疗前显著降低(P<0.05);治疗1、4、8周治疗组PASI评分显著低于对照组(P<0.05).治疗后,两组患者血清炎性因子白细胞介素6(IL-6)、白细胞介素17(IL-17)、肿瘤坏死因子α(TNF-α)、干扰素-γ(IFN-γ)水平均较治疗前显著降低(P<0.05);治疗后,治疗组血清炎性因子水平显著低于对照组(P<0.05).结论 丹青胶囊联合他扎罗汀倍他米松治疗银屑病效果明显,能显著降低炎性因子水平,并有助于改善皮损情况,值得临床推广应用.  相似文献   
7.
8.
Bacterial keratitis continues to be one of the leading causes of corneal blindness in the developed as well as the developing world, despite swift progress since the dawn of the “anti-biotic era”. Although, we have expeditiously developed our understanding about the different causative organisms and associated pathology leading to keratitis, extensive gaps in knowledge continue to dampen the efforts required for early and accurate diagnosis, and management in these patients, resulting in poor clinical outcomes. The ability of the causative bacteria to subdue the therapeutic challenge stems from their large genome encoding complex regulatory networks, variety of unique virulence factors, and rapid secretion of tissue damaging proteases and toxins.In this review article, we provide an overview of the established diagnostic techniques and therapeutics for keratitis caused by various bacteria. We extensively report the recent in-roads through novel tools for accurately diagnosing mono- and poly-bacterial corneal infections. Furthermore, we outline the recent progress by our groups and others in understanding the sub-cellular genomic changes that lead to antibiotic resistance in these organisms. Finally, we discuss in detail, the novel therapies and drug delivery systems in development for the efficacious management of bacterial keratitis.  相似文献   
9.
10.
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