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   1173641篇
  免费   71416篇
  国内免费   10360篇
耳鼻咽喉   13871篇
儿科学   36073篇
妇产科学   34196篇
基础医学   141405篇
口腔科学   32166篇
临床医学   113372篇
内科学   240180篇
皮肤病学   26589篇
神经病学   105960篇
特种医学   45267篇
外国民族医学   14篇
外科学   182606篇
综合类   27836篇
现状与发展   60篇
一般理论   702篇
预防医学   74314篇
眼科学   25297篇
药学   64836篇
  191篇
中国医学   13926篇
肿瘤学   76556篇
  2023年   27578篇
  2022年   41130篇
  2021年   47756篇
  2020年   45716篇
  2019年   32075篇
  2018年   36897篇
  2017年   35877篇
  2016年   35567篇
  2015年   36779篇
  2014年   64194篇
  2013年   58319篇
  2012年   55592篇
  2011年   55371篇
  2010年   48311篇
  2009年   43938篇
  2008年   44083篇
  2007年   45877篇
  2006年   42218篇
  2005年   38723篇
  2004年   35855篇
  2003年   34631篇
  2002年   33864篇
  2001年   32718篇
  2000年   32028篇
  1999年   29002篇
  1998年   12016篇
  1997年   9594篇
  1996年   9533篇
  1995年   8729篇
  1994年   7201篇
  1993年   6026篇
  1992年   21182篇
  1991年   20714篇
  1990年   20056篇
  1989年   17227篇
  1988年   16371篇
  1987年   8702篇
  1986年   3812篇
  1985年   4818篇
  1984年   5450篇
  1983年   4603篇
  1982年   4722篇
  1981年   4359篇
  1980年   3993篇
  1979年   3571篇
  1978年   3352篇
  1977年   2827篇
  1976年   2590篇
  1974年   2373篇
  1973年   2301篇
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
1.
2.
  1. Download : Download high-res image (243KB)
  2. Download : Download full-size image
  相似文献   
3.
IntroductionDeferred treatment is a growing management strategy for low-risk prostate cancer. However, it is unknown whether this growth is mediated by patient factors. In this study, we sought to evaluate factors associated with deferred treatment in patients with low-risk prostate cancer and shifts in these factors after recent incorporation of active surveillance into national guidelines.Materials and MethodsWe identified 137,915 men diagnosed with low-risk prostate cancer (prostate-specific antigen <10 ng/mL, Gleason score ≤6, stage cT1-cT2a) in the National Cancer Database from 2010 to 2017. Multivariate logistic regression models were used to determine factors associated with deferred treatment. Interaction variables were added to determine whether trends in use of deferred treatment over time depend on race, income, education, and insurance status.ResultsThe use of deferred treatment among men with low-risk prostate cancer increased from 14.7% in 2010-2011 to 46.3% in 2016-2017 (P < .001). On multivariate analysis, deferred treatment was associated with older age, more contemporary year of diagnosis, black race, lower income, higher educational attainment, government insurance, being uninsured, treatment at an academic/research facility, and treatment at a facility in New England (each P < .05). Incorporation of interaction variables showed that black race, belonging to the two lowest income quartiles, government insurance, and being uninsured became less associated with deferred treatment in recent years.ConclusionsThe use of deferred treatment among men with low-risk prostate cancer increased significantly from 2010 to 2017. However, patients who were black, low-income, and not privately insured experienced smaller increases in deferred treatment. Interventions to increase uptake in these groups present opportunities to improve quality of care.  相似文献   
4.
5.
ObjectiveNew-onset postoperative atrial fibrillation (POAF) after cardiac surgery is common, with rates up to 60%. POAF has been associated with early and late stroke, but its association with other cardiovascular outcomes is less known. The objective was to perform a meta-analysis of the studies reporting the association of POAF with perioperative and long-term outcomes in patients with cardiac surgery.MethodsWe performed a systematic review and a meta-analysis of studies that presented outcomes for cardiac surgery on the basis of the presence or absence of POAF. MEDLINE, EMBASE, and the Cochrane Library were assessed; 57 studies (246,340 patients) were selected. Perioperative mortality was the primary outcome. Inverse variance method and random model were performed. Leave-one-out analysis, subgroup analyses, and metaregression were conducted.ResultsPOAF was associated with perioperative mortality (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.58-2.33), perioperative stroke (OR, 2.17; 95% CI, 1.90-2.49), perioperative myocardial infarction (OR, 1.28; 95% CI, 1.06-1.54), perioperative acute renal failure (OR, 2.74; 95% CI, 2.42-3.11), hospital (standardized mean difference, 0.80; 95% CI, 0.53-1.07) and intensive care unit stay (standardized mean difference, 0.55; 95% CI, 0.24-0.86), long-term mortality (incidence rate ratio [IRR], 1.54; 95% CI, 1.40-1.69), long-term stroke (IRR, 1.33; 95% CI, 1.21-1.46), and longstanding persistent atrial fibrillation (IRR, 4.73; 95% CI, 3.36-6.66).ConclusionsThe results suggest that POAF after cardiac surgery is associated with an increased occurrence of most short- and long-term cardiovascular adverse events. However, the causality of this association remains to be established.  相似文献   
6.
  1. Download : Download high-res image (158KB)
  2. Download : Download full-size image
  相似文献   
7.
8.
BackgroundThis systematic review aims to determine the epidemiological profile, etiology and risk factors, prevention, diagnosis, treatment, cost-effectiveness, survival, and quality of life related to cervical cancer in Morocco.MethodsThis study was conducted according to the recommendations of the "preferred reporting items for systematic reviews and meta-analysis." The PubMed, ScienceDirect, Springer, Web of Science data bases were used, as was Google Scholar for the grey literature. The review protocol was registered in the PROSPERO register (CRD42021235241).ResultsFifty studies were selected. The mean age was 49.31 ±6.3 years. HPV infection prevalence ranged from 13.30% to 76%, with a peak in HIV-positive women. Acceptability of the HPV vaccine was higher among parents (35% and 82%) than among adolescents (16.9% to 46.6%). Knowledge of the vaccine and its price are two key factors related to vaccine acceptability among parents. This systematic review highlights that the fact that few eligible women (not more than 11%) were participating in the cervical cancer screening program. Moroccan women's level of knowledge and awareness regarding cervical cancer screening was low, negatively impacting their use of such screening tools, as illustrated by the high percentage (mean 76.32% ± 17.21) of women who had never been screened for cervical cancer. Treatment was the most significant component of the global care budget (95.87%), with an annual cost of $13,027,609. Five-year overall survival ranged from 41.3% to 73.6%, with higher survival rates for patients diagnosed at an earlier stage (77.3–85% for stage I). Lastly, low quality of life was observed in women with tumors at an advanced stage who had received brachytherapy and lacked social support.ConclusionsSubjects that require further investigation include Moroccan women's knowledge, attitudes, and awareness, especially among those at high risk of developing cervical cancer, and its impact on their quality of life and survival.  相似文献   
9.
Microcephaly is a frequent feature of neurodevelopmental disorders (NDDs). Our study presents the heterogeneous spectrum of genetic disorders in patients with microcephaly either in isolated form or in association with other neurological and extra-neural abnormalities. We present data of 91 patients from 87 unrelated families referred to our clinic during 2016–2020 and provide a comprehensive clinical and genetic landscape in the studied cohort. Molecular diagnosis using exome sequencing was made in 45 families giving a yield of 51.7%. In 9 additional families probable causative variants were detected. We identified disease causing variations in 49 genes that are involved in different functional pathways Among these, 36 had an autosomal recessive pattern, 8 had an autosomal dominant pattern (all inherited de novo), and 5 had an X-linked pattern. In 41 probands where sequence variations in autosomal recessive genes were identified 31 were homozygotes (including 16 from non-consanguineous families). The study added 28 novel pathogenic/likely pathogenic variations. The study also calls attention to phenotypic variability and expansion in spectrum as well as uncovers genes where microcephaly is not reported previously or is a rare finding. We here report phenotypes associated with the genes for ultra-rare NDDs with microcephaly namely ATRIP, MINPP1, PNPLA8, AIMP2, ANKLE2, NCAPD2 and TRIT1.  相似文献   
10.
Background/PurposeA small number of Hirschsprung disease (HD) patients develop inflammatory bowel disease (IBD)-like symptoms after pullthrough surgery. The etiology and pathophysiology of Hirschsprung-associated IBD (HD-IBD) remains unknown. This study aims to further characterize HD-IBD, to identify potential risk factors and to evaluate response to treatment in a large group of patients.MethodsRetrospective study of patients diagnosed with IBD after pullthrough surgery between 2000 and 2021 at 17 institutions. Data regarding clinical presentation and course of HD and IBD were reviewed. Effectiveness of medical therapy for IBD was recorded using a Likert scale.ResultsThere were 55 patients (78% male). 50% (n = 28) had long segment disease. Hirschsprung-associated enterocolitis (HAEC) was reported in 68% (n = 36). Ten patients (18%) had Trisomy 21. IBD was diagnosed after age 5 in 63% (n = 34). IBD presentation consisted of colonic or small bowel inflammation resembling IBD in 69% (n = 38), unexplained or persistent fistula in 18% (n = 10) and unexplained HAEC >5 years old or unresponsive to standard treatment in 13% (n = 7). Biological agents were the most effective (80%) medications. A third of patients required a surgical procedure for IBD.ConclusionMore than half of the patients were diagnosed with HD-IBD after 5 years old. Long segment disease, HAEC after pull through operation and trisomy 21 may represent risk factors for this condition. Investigation for possible IBD should be considered in children with unexplained fistulae, HAEC beyond the age of 5 or unresponsive to standard therapy, and symptoms suggestive of IBD. Biological agents were the most effective medical treatment.Level of EvidenceLevel 4  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