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   920644篇
  免费   65988篇
  国内免费   4382篇
耳鼻咽喉   12785篇
儿科学   28923篇
妇产科学   26474篇
基础医学   128595篇
口腔科学   25175篇
临床医学   77933篇
内科学   185229篇
皮肤病学   19294篇
神经病学   72286篇
特种医学   37475篇
外国民族医学   352篇
外科学   144207篇
综合类   23896篇
一般理论   253篇
预防医学   66059篇
眼科学   20883篇
药学   66714篇
  16篇
中国医学   3496篇
肿瘤学   50969篇
  2019年   7355篇
  2018年   9979篇
  2017年   8210篇
  2016年   8475篇
  2015年   9977篇
  2014年   14074篇
  2013年   20769篇
  2012年   27897篇
  2011年   29649篇
  2010年   18097篇
  2009年   16956篇
  2008年   27701篇
  2007年   29247篇
  2006年   29328篇
  2005年   28865篇
  2004年   27269篇
  2003年   26369篇
  2002年   25786篇
  2001年   41937篇
  2000年   43008篇
  1999年   36597篇
  1998年   9732篇
  1997年   8820篇
  1996年   8677篇
  1995年   8673篇
  1994年   8281篇
  1993年   7723篇
  1992年   28339篇
  1991年   27149篇
  1990年   26516篇
  1989年   25461篇
  1988年   23654篇
  1987年   23236篇
  1986年   22309篇
  1985年   21200篇
  1984年   15806篇
  1983年   13475篇
  1982年   8050篇
  1979年   14577篇
  1978年   10182篇
  1977年   8608篇
  1976年   8127篇
  1975年   8940篇
  1974年   10684篇
  1973年   10174篇
  1972年   9662篇
  1971年   8914篇
  1970年   8576篇
  1969年   8015篇
  1968年   7672篇
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
1.
2.
Graefe's Archive for Clinical and Experimental Ophthalmology - Ferromagnetic foreign bodies (FFB) present during magnetic resonance imaging (MRI) explorations can lead to tissue injury due to...  相似文献   
3.
4.
Immunologic Research - Hyper immunoglobulin M (HIGM) syndrome is a rare disorder of the immune system with impaired antibody functions. The clinical picture of the patients varies according to the...  相似文献   
5.
目的 分析重症患者营养支持期间发生再喂养综合征的危险因素,为早期识别及预防再喂养综合征提供参考。方法 检索中国知网、万方数据库、中华医学期刊全文数据库、中国生物医学文献数据库、维普网、PubMed、Embase、Cochrane Library、Elsevier关于重症患者再喂养综合征危险因素的文献,检索时间为各数据库建库至2021年12月,采用RevMan5.3进行Meta分析。结果 纳入13篇文献,包括2 519例患者,其中病例组793例,对照组1 726例;Meta分析合并效应值显示年龄(WMD=4.69)、APACHEⅡ评分(WMD=2.50)、BMI(WMD=-0.94)、白蛋白水平(OR=4.61)、前白蛋白水平(WMD=-53.46)、基线血镁水平(WMD=-0.05)、基线血钾水平(WMD=0.18)、基线血磷水平(WMD=-0.07)是重症患者发生再喂养综合征的危险因素(P<0.05,P<0.01)。结论 基于现有证据,重症患者再喂养综合征的危险因素包括年龄、APACHEⅡ评分、营养状况及电解质水平,医护人员需密切关注重症患者营养支持期间能量、蛋白质及电解...  相似文献   
6.

A positive relationship between treatment volume and outcome quality has been demonstrated in the literature and is thus evident for a variety of procedures. Consequently, policy makers have tried to translate this so-called volume–outcome relationship into minimum volume regulation (MVR) to increase the quality of care—yet with limited success. Until today, the effect of strict MVR application remains unclear as outcome quality gains cannot be estimated adequately and restrictions to application such as patient travel time and utilization of remaining hospital capacity are not considered sufficiently. Accordingly, when defining MVR, its effectiveness cannot be assessed. Thus, we developed a mixed integer programming model to define minimum volume thresholds balancing utility in terms of outcome quality gain and feasibility in terms of restricted patient travel time and utilization of hospital capacity. We applied our model to the German hospital sector and to four surgical procedures. Results showed that effective MVR needs a minimum volume threshold of 125 treatments for cholecystectomy, of 45 and 25 treatments for colon and rectum resection, respectively, of 32 treatments for radical prostatectomy and of 60 treatments for total knee arthroplasty. Depending on procedure type and incidence as well as the procedure’s complication rate, outcome quality gain ranged between 287 (radical prostatectomy) and 977 (colon resection) avoidable complications (11.7% and 11.9% of all complications). Ultimately, policy makers can use our model to leverage MVR’s intended benefit: concentrating treatment delivery to improve the quality of care.

  相似文献   
7.
Gestational trophoblastic neoplasia (GTN) patients are treated according to the eight-variable International Federation of Gynaecology and Obstetrics (FIGO) scoring system, that aims to predict first-line single-agent chemotherapy resistance. FIGO is imperfect with one-third of low-risk patients developing disease resistance to first-line single-agent chemotherapy. We aimed to generate simplified models that improve upon FIGO. Logistic regression (LR) and multilayer perceptron (MLP) modelling (n = 4191) generated six models (M1-6). M1, all eight FIGO variables (scored data); M2, all eight FIGO variables (scored and raw data); M3, nonimaging variables (scored data); M4, nonimaging variables (scored and raw data); M5, imaging variables (scored data); and M6, pretreatment hCG (raw data) + imaging variables (scored data). Performance was compared to FIGO using true and false positive rates, positive and negative predictive values, diagnostic odds ratio, receiver operating characteristic (ROC) curves, Bland-Altman calibration plots, decision curve analysis and contingency tables. M1-6 were calibrated and outperformed FIGO on true positive rate and positive predictive value. Using LR and MLP, M1, M2 and M4 generated small improvements to the ROC curve and decision curve analysis. M3, M5 and M6 matched FIGO or performed less well. Compared to FIGO, most (excluding LR M4 and MLP M5) had significant discordance in patient classification (McNemar's test P < .05); 55-112 undertreated, 46-206 overtreated. Statistical modelling yielded only small gains over FIGO performance, arising through recategorisation of treatment-resistant patients, with a significant proportion of under/overtreatment as the available data have been used a priori to allocate primary chemotherapy. Streamlining FIGO should now be the focus.  相似文献   
8.
The Dutch Drug Rediscovery Protocol (DRUP) and the Australian Cancer Molecular Screening and Therapeutic (MoST) Program are similar nonrandomized, multidrug, pan-cancer trial platforms that aim to identify signals of clinical activity of molecularly matched targeted therapies or immunotherapies outside their approved indications. Here, we report results for advanced or metastatic cancer patients with tumors harboring cyclin D-CDK4/6 pathway alterations treated with CDK4/6 inhibitors palbociclib or ribociclib. We included adult patients that had therapy-refractory solid malignancies with the following alterations: amplifications of CDK4, CDK6, CCND1, CCND2 or CCND3, or complete loss of CDKN2A or SMARCA4. Within MoST, all patients were treated with palbociclib, whereas in DRUP, palbociclib and ribociclib were assigned to different cohorts (defined by tumor type and alteration). The primary endpoint for this combined analysis was clinical benefit, defined as confirmed objective response or stable disease ≥16 weeks. We treated 139 patients with a broad variety of tumor types; 116 with palbociclib and 23 with ribociclib. In 112 evaluable patients, the objective response rate was 0% and clinical benefit rate at 16 weeks was 15%. Median progression-free survival was 4 months (95% CI: 3-5 months), and median overall survival 5 months (95% CI: 4-6 months). In conclusion, only limited clinical activity of palbociclib and ribociclib monotherapy in patients with pretreated cancers harboring cyclin D-CDK4/6 pathway alterations was observed. Our findings indicate that monotherapy use of palbociclib or ribociclib is not recommended and that merging data of two similar precision oncology trials is feasible.  相似文献   
9.
Journal of Immigrant and Minority Health - COVID-19 has disproportionally affected underrepresented minorities (URM) and low-income immigrants in the United States. The aim of the study is to...  相似文献   
10.
Münch  F.  Purbojo  A.  Wenzel  F.  Kohl  M.  Dittrich  S.  Rauh  M.  Zimmermann  R.  Kwapil  N. 《Der Anaesthesist》2022,71(11):882-892
Die Anaesthesiologie - Die Transfusion von Erythrozytenkonzentraten (EK) ist mit verschiedenen Nebenwirkungen assoziiert, die u. a. durch Lagerungsschäden an Erythrozyten hervorgerufen...  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