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   3579049篇
  免费   256851篇
  国内免费   9194篇
耳鼻咽喉   47537篇
儿科学   119039篇
妇产科学   98556篇
基础医学   497745篇
口腔科学   96169篇
临床医学   324553篇
内科学   699548篇
皮肤病学   82062篇
神经病学   296164篇
特种医学   138781篇
外国民族医学   1111篇
外科学   538585篇
综合类   76328篇
现状与发展   7篇
一般理论   1334篇
预防医学   281789篇
眼科学   80062篇
药学   256666篇
  8篇
中国医学   7874篇
肿瘤学   201176篇
  2019年   27456篇
  2018年   57415篇
  2017年   44438篇
  2016年   51329篇
  2015年   39116篇
  2014年   53963篇
  2013年   80594篇
  2012年   112579篇
  2011年   131340篇
  2010年   83734篇
  2009年   74816篇
  2008年   122385篇
  2007年   131367篇
  2006年   113963篇
  2005年   111475篇
  2004年   108303篇
  2003年   105667篇
  2002年   100413篇
  2001年   165725篇
  2000年   169979篇
  1999年   142683篇
  1998年   41423篇
  1997年   36965篇
  1996年   36845篇
  1995年   35643篇
  1994年   32574篇
  1993年   30458篇
  1992年   110103篇
  1991年   105745篇
  1990年   102468篇
  1989年   98670篇
  1988年   90509篇
  1987年   88675篇
  1986年   83031篇
  1985年   79479篇
  1984年   59578篇
  1983年   50513篇
  1982年   30254篇
  1981年   26910篇
  1979年   52707篇
  1978年   37301篇
  1977年   31398篇
  1976年   29291篇
  1975年   30796篇
  1974年   36673篇
  1973年   35044篇
  1972年   32956篇
  1971年   30472篇
  1970年   28333篇
  1969年   26987篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
32.
Cognitive Therapy and Research - Despite interest in psychological inflexibility as a marker of suicide risk, no measure of psychological inflexibility specific to SI exists. The present study...  相似文献   
33.
34.
35.
36.
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   
37.
Heart Failure Reviews - The nitric oxide (NO)–guanylate cyclase (GC)–cyclic guanosine monophosphate (cGMP) pathway plays an important role in cardiovascular, pulmonary and renal...  相似文献   
38.
Comprehensive evidence regarding the treatment of non-anaemic iron deficiency in patients undergoing valvular heart surgery is lacking. This study aimed to investigate the association between non-anaemic iron deficiency and postoperative outcomes in these patients. We retrospectively analysed 321 patients of which 180 (56%) had iron deficiency (defined as serum ferritin < 100 ng.ml-1 or < 300 ng.ml-1 with transferrin saturation < 20%). While the iron-deficient group had lower pre-operative haemoglobin levels than the non-iron deficient group (median (IQR [range]) 134 (127–141 [120–172]) g.l-1, 143 (133–150 [120–179]) g.l-1, p = 0.001), there was no between-group difference in allogeneic red blood cell transfusion. Median (IQR [range]) days alive and out of hospital at postoperative day 90 was 1 day shorter in the iron-deficient group (80 (77–82 [9–85]) days vs. 81 (79–83 [0–85]) days, p = 0.026). In multivariable analysis, only cardiopulmonary bypass duration (p = 0.032) and intra-operative allogeneic red blood cell transfusion (p = 0.011) were significantly associated with reduced days alive and out of hospital at postoperative day 90. Iron deficiency did not exert any adverse influence on secondary outcomes except length of hospital stay. Our findings indicate that non-anaemic iron deficiency alone is not associated with adverse effects in patients undergoing valvular heart surgery when it does not translate into an increased risk of allogeneic transfusion.  相似文献   
39.
Vaccination is a vital health care initiative to prevent individual and population infection. To increase vaccination rates the federal government implemented the ‘No Jab, No Pay’ policy, where eligibility for several government benefits required children to be fully vaccinated by removing ‘conscientious objections’ and expanding the age range of children whose families receive benefits. This study assesses the impact of this policy at a local area within a single medical practice community in NSW, Australia. A retrospective clinical audit was performed between 2012 and 2017 on a single general practice's vaccination records for children ≤19 years. Catch-up vaccinations were assessed based on age at vaccination. Incidence of catch-up vaccinations was assessed for each of four years before and two years after the implementation of the ‘No Jab, No Pay’ policy in January 2016, along with the age of children and vaccination(s) given. Catch-up vaccinations were assessed temporally either side of implementation of ‘No Jab, No Pay’. Comparing the average annual vaccination catch-up incidence rate of 6.2% pre-implementation (2012–2015), there was an increase to 9.2% in 2016 (p < .001) and 7.8% in 2017 (p = .027). Secondary outcome measurement of catch-up vaccination incidence rates before (2012–2015) and after (2016–2017) ‘No Jab, No Pay’ implementation showed statistically significant increases for children aged 8–11 years (3.2%–5.6%, p = .038), 12–15 years (7.5%–14.7%, p < .001) and 16–19 years (3.3%–10.2%, p < .001) along with a statistically significant reduction in children aged 1–3 years (11.4%–6.2%, p = .015). Also, catch-up rates for DTPa significantly increased after program implementation. This study demonstrates that the Australian federal government vaccination policy ‘No Jab, No Pay’ was coincident with an increase in catch-up vaccinations within a rural NSW community served by one medical practice, especially for older children.  相似文献   
40.

Female Genital mutilation/cutting (FGM/C) is associated with enduring psychiatric complications. In this study, we investigate the rates of co-morbid abuses and polyvictimization experienced by survivors of FGM/C. This is a sub-analysis of a cohort study examining the patient population at the EMPOWER Center for Survivors of Sex Trafficking and Sexual Violence in New York City. A retrospective chart-review of electronic medical records was conducted for all consenting adult patients who had FGM/C and had an intake visit between January 16, 2014 and March 6, 2020. Of the 80 participants, ages ranged from 20 to 62 years with a mean of 37.4 (SD?=?9.1) years. In addition to FGM/C, participants were victims of physical abuse (43; 53.8%), emotional abuse (35; 43.8%), sexual abuse (35; 43.8%), forced marriage (20; 25%), child marriage (13; 16.3%), and sex trafficking (1; 1.4%). There was a high degree of polyvictimization, with 41 (51.2%) experiencing 3 or more of the aforementioned abuses. Having FGM/C on or after age 13 or having a higher total abuse score was also found to be strong predictors of depression and PTSD. The high rates of polyvictimization among survivors of FGM/C are associated with development of depression and PTSD. Despite co-morbid abuses, patients still attribute substantial psychiatric symptoms to their FGM/C. Health care providers should understand the high risk of polyvictimization when caring for this patient population.

  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