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   1095760篇
  免费   72359篇
  国内免费   1413篇
耳鼻咽喉   15934篇
儿科学   35343篇
妇产科学   29778篇
基础医学   156059篇
口腔科学   29961篇
临床医学   96211篇
内科学   208107篇
皮肤病学   24785篇
神经病学   83553篇
特种医学   43283篇
外国民族医学   201篇
外科学   164671篇
综合类   21763篇
现状与发展   1篇
一般理论   267篇
预防医学   76294篇
眼科学   25110篇
药学   88613篇
  7篇
中国医学   2873篇
肿瘤学   66718篇
  2019年   8163篇
  2018年   11983篇
  2017年   9416篇
  2016年   10577篇
  2015年   11717篇
  2014年   16005篇
  2013年   23262篇
  2012年   31902篇
  2011年   33909篇
  2010年   19825篇
  2009年   18284篇
  2008年   31032篇
  2007年   33484篇
  2006年   34146篇
  2005年   32446篇
  2004年   31189篇
  2003年   30012篇
  2002年   28707篇
  2001年   60550篇
  2000年   62040篇
  1999年   51313篇
  1998年   12564篇
  1997年   11056篇
  1996年   11057篇
  1995年   10368篇
  1994年   9388篇
  1993年   8898篇
  1992年   37862篇
  1991年   36339篇
  1990年   35812篇
  1989年   34332篇
  1988年   30904篇
  1987年   30024篇
  1986年   28251篇
  1985年   26484篇
  1984年   19219篇
  1983年   16140篇
  1982年   8846篇
  1979年   17061篇
  1978年   11436篇
  1977年   10259篇
  1976年   8858篇
  1975年   10091篇
  1974年   11668篇
  1973年   11288篇
  1972年   10771篇
  1971年   10103篇
  1970年   9256篇
  1969年   8946篇
  1968年   7926篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Digestive Diseases and Sciences - To determine whether the presence of portal vein thrombosis (PVT) where venous flow within the liver may be altered may delay the diagnosis of HCC and be...  相似文献   
92.

Background and aims

It is not known whether non alcoholic fatty liver disease (NAFLD) is a risk factor for diabetes in non obese, non centrally-obese subjects. Our aim was to investigate relationships between fatty liver, insulin resistance and a biomarker score for liver fibrosis with incident diabetes at follow up, in subjects who were neither obese nor centrally-obese.

Methods and results

As many as 70,303 subjects with a body mass index (BMI) < 25 kg/m2 and without diabetes were followed up for a maximum of 7.9 years. At baseline, fatty liver was identified by liver ultrasound, insulin resistance (IR) by homeostatic model assessment of insulin resistance (HOMA-IR) ≥2.0, and central obesity by waist circumference (waist circumference ≥90 cm (men) and ≥85 cm (women). The Fibrosis-4 (FIB-4 score) was used to estimate extent of liver fibrosis. Cox proportional hazards models adjusted for confounders were used to estimate hazard ratios (aHRs) for incident diabetes. As many as 852 incident cases of diabetes occurred during follow up (median [IQR] 3.71 [2.03] years). Mean ± SD BMI was 22.8 ± 1.8 and 21.7 ± 2.0 kg/m2 in subjects with and without diabetes at follow up. In subjects without central obesity and with fatty liver, aHRs (95% CI) for incident diabetes at follow up were 2.17 (1.56, 3.03) for men, and 2.86 (1.50,5.46) for women. Similar aHRs for incident diabetes occurred with fatty liver, IR and the highest quartile of FIB-4 combined, in men; and there was a non significant trend toward increased risk in women.

Conclusions

In normal weight, non-centrally obese subjects NAFLD is an independent risk factor for incident diabetes.  相似文献   
93.
94.
95.
Parhiala  P.  Ranta  K.  Gergov  V.  Kontunen  J.  Law  R.  La Greca  A. M.  Torppa  M.  Marttunen  M. 《School mental health》2020,12(2):265-283

In order to offer early and accessible treatment for adolescents with depression, brief and effective treatments in adolescents’ everyday surroundings are needed. This randomized controlled trial studied the preliminary effectiveness, feasibility, and acceptability of interpersonal counseling (IPC) and brief psychosocial support (BPS) in school health and welfare services. The study was conducted in the 28 lower secondary schools of a large city in Southern Finland, randomized to provide either IPC or BPS. Help-seeking 12–16-year-old adolescents with mild-to-moderate depression, with and without comorbid anxiety, were included in the study. Fifty-five adolescents received either 6 weekly sessions of IPC or BPS and two follow-up sessions. Outcome measures included self- and clinician-rated measures of depression, global functioning, and psychological distress/well-being. To assess feasibility and acceptability of the treatments, adolescents’ and counselors’ treatment compliance and satisfaction with treatment were assessed. Both treatments were effective in reducing depressive disorders and improving adolescents’ overall functioning and well-being. At post-treatment, in both groups, over 50% of adolescents achieved recovery based on self-report and over 70% based on observer report. Effect sizes for change were medium or large in both groups at post-treatment and increased at 6-month follow-up. A trend indicating greater baseline symptom severity among adolescents treated in the IPC-providing schools was observed. Adolescents and counselors in both groups were satisfied with the treatment, and 89% of the adolescents completed the treatments and follow-ups. This trial suggests that both IPC and BPS are feasible, acceptable, and effective treatments for mild-to-moderate depression in the school setting. In addition, IPC seems effective even if comorbid anxiety exists. Our study shows that brief, structured interventions, such as IPC and BPS, are beneficial in treating mild-to-moderate depression in school settings and can be administered by professionals working at school.

Trial registrationhttp://www.clinicaltrials.gov. Unique identifier: NCT03001245.

  相似文献   
96.
97.
This study qualitatively examined factors that influenced contraceptive choices in a sample of young, HIV-infected women. Individual qualitative interviews were conducted among 30 vertically and horizontally HIV-infected women (= 26 African American) from the ages of 14 to 24 years (Mean age = 20.9 years). We recruited sample groups with the following characteristics: (a) current contraceptive/condom use with ≥1 child (= 11); (b) current contraceptive/condom use with no children (= 12); and (c) no current contraceptive/condom use with no children (= 7). A semi-structured interview guide was used to ask participants about factors influencing past and current contraceptive choices. Individual interviews were digitally recorded and transcribed verbatim; analyses to identify core themes were informed by the Grounded Theoretical approach. Young, HIV-infected women did not identify their HIV serostatus or disease-related concerns as influential in their contraceptive decisions. However, they reported that recommendations from health-care providers and input from family and friends influenced their contraceptive choices. They also considered a particular method’s advantages (e.g., menstrual cycle improvements) and disadvantages (e.g., increased pill burden) when selecting a method. Findings suggested that HIV-infected young women’s contraceptive decisions were influenced by factors other than those related to their infection.  相似文献   
98.
99.
100.
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