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   122730篇
  免费   8457篇
  国内免费   433篇
耳鼻咽喉   1628篇
儿科学   3292篇
妇产科学   2087篇
基础医学   15619篇
口腔科学   2369篇
临床医学   12463篇
内科学   25686篇
皮肤病学   1906篇
神经病学   11763篇
特种医学   4260篇
外国民族医学   4篇
外科学   17960篇
综合类   1888篇
一般理论   167篇
预防医学   10944篇
眼科学   2908篇
药学   8705篇
  2篇
中国医学   171篇
肿瘤学   7798篇
  2023年   474篇
  2022年   309篇
  2021年   1770篇
  2020年   1234篇
  2019年   2007篇
  2018年   2317篇
  2017年   1794篇
  2016年   1949篇
  2015年   2413篇
  2014年   3448篇
  2013年   5344篇
  2012年   7782篇
  2011年   8301篇
  2010年   4701篇
  2009年   4524篇
  2008年   7986篇
  2007年   8516篇
  2006年   8355篇
  2005年   8636篇
  2004年   8176篇
  2003年   7991篇
  2002年   7554篇
  2001年   1164篇
  2000年   906篇
  1999年   1117篇
  1998年   1477篇
  1997年   1190篇
  1996年   962篇
  1995年   1127篇
  1994年   939篇
  1993年   952篇
  1992年   759篇
  1991年   708篇
  1990年   672篇
  1989年   615篇
  1988年   570篇
  1987年   548篇
  1986年   551篇
  1985年   675篇
  1984年   834篇
  1983年   817篇
  1982年   1148篇
  1981年   1037篇
  1980年   943篇
  1979年   460篇
  1978年   565篇
  1977年   538篇
  1976年   436篇
  1975年   402篇
  1974年   360篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
The purpose of this study was to provide an evidence base for colorectal cancer research activity that might influence policy, mainly at the national level. Improvements in healthcare delivery have lengthened life expectancy, but within a situation of increased cancer incidence. The disease burden of CRC has risen significantly, particularly in Africa, Asia and Latin America. Research is key to its control and reduction, but few studies have delineated the volume and funding of global research on CRC. We identified research papers in the Web of Science (WoS) from 2007 to 2021, and determined the contributions of the leading countries, the research domains studied, and their sources of funding. We identified 62 716 papers, representing 5.7% of all cancer papers. This percentage was somewhat disproportionate to the disease burden (7.7% in 2015), especially in Eastern Europe. International collaboration increased over the time period in almost all countries except in China. Genetics, surgery and prognosis were the leading research domains. However, research on palliative care and quality-of-life in CRC was lacking. In Western Europe, the main funding source was the charity sector, particularly in the UK, but in most other countries government played the leading role, especially in China and the USA. There was little support from industry. Several Asian countries provided minimal contestable funding, which may have reduced the impact of their CRC research. Certain countries must perform more CRC research overall, especially in domains such as screening, palliative care and quality-of-life. The private-non-profit sector should be an alternative source of support.  相似文献   
3.
We are reporting (a) updated incidence of cervical intraepithelial neoplasia (CIN) among women who did not have colposcopic or histopathological disease at baseline and (b) disease outcomes among women treated for CIN and their follow-up HPV status; in a cohort of women living with HIV (WHIV). The median overall follow-up was 3.5 years (IQR 2.8-4.3). The incidence of any CIN and that of CIN 2 or worse disease was 16.7 and 7.0 per 1000 person-years of observation (PYO), respectively. Compared with women who were HPV negative at baseline, women who cleared HPV infection had 23.95 times increased risk of incident CIN 2 or worse lesions (95% CI 2.40-661.07). Women with persistent HPV infection had 138.18 times increased risk of CIN 2 or worse lesions (95% CI 20.30-3300.22). Complete disease regression was observed in 65.6% of the HPV positive women with high-grade CIN and were treated with thermal ablation but HPV persistence was seen in 44.8% of those with high-grade disease. Among those who did not have any disease at baseline and were also HPV negative, about 87% (95% CI 83.79-89.48) women remained HPV negative during consecutive HPV test/s with the median interval of 3.5 years. Long-term surveillance of WHIV treated for any CIN is necessary for the prevention of cervical cancer among them. Our study provides an early indication that the currently recommended screening interval of 3 to 5 years among WHIV may be extended to at least 5 years among HPV negative women. Increasing the screening interval can be cost saving and improve scalability among WHIV to support WHO's cervical cancer elimination initiative.  相似文献   
4.
5.
6.
BackgroundThe purpose of this study is to evaluate the effect of body mass index (BMI) on discharge to a postacute care (PAC) facility following elective total shoulder arthroplasty (TSA).MethodsThe National Surgical Quality Improvement Program database was queried to identify adult patients (>18 years old) who underwent inpatient TSA for primary osteoarthritis between 2005 and 2018. Hemiarthroplasty, revision TSA, trauma indications, and outpatient procedures were excluded. Patient and perioperative data were identified. Univariate analysis and multivariate logistic regression were used to assess the relationship between BMI and discharge to PAC facilities.ResultsA total of 10,198 patients with a primary TSA were identified. The majority (93%) of patients were discharged home vs. 7% to PAC facilities. Patients discharged to PAC had significantly higher mean BMI (P = .006). After controlling for demographic and comorbid factors, BMI was the only modifiable risk factor that was independently associated with an increased risk of discharge to a PAC. For every increase in BMI point, there was an increased risk of discharge to a PAC by 2.9% (odds ratio [OR] 1.029, confidence interval [CI] 1.016-1.041, P < .001). Additional covariates associated with PAC discharge were older age (OR 1.113, CI 1.099-1.127, P < .001), female gender (OR 3.037, CI 2.489-3.705, P < .001), and dependent functional status (OR 8.322, CI 5.544-12.492, P < .001).ConclusionMost patients undergoing TSA were discharged home following surgery. While age, sex, and functional status also affect disposition, elevated BMI is the only modifiable risk factor that independently predicts PAC discharge. Consideration of patient BMI prior to elective TSA may greatly improve discharge planning and management of patient expectations.  相似文献   
7.
8.
9.
10.

Background

There is evidence linking metformin to improved prostate cancer–related outcomes.

Patients and Methods

Twenty-five men with metastatic castration-resistant prostate cancer and prostate-specific antigen (PSA) progression while receiving treatment with abiraterone from 3 Swiss centers were included in this single-arm phase 2 trial between November 2013 and September 2016. Metformin was added to abiraterone continuously at 1000 mg twice daily in uninterrupted 4-week cycles. The primary end point was the absence of disease progression at 12 weeks (PFS12). The Fleming single-stage design was applied. With a 5% significance level and 80% power, 25 patients were required to test PFS12 ≤ 15% (H0) compared to ≥ 35% (H1). Secondary end points included toxicity and safety issues. The study was registered at ClinicalTrials.gov (NCT01677897).

Results

The primary end point PFS12 was 12% (3 of 25 patients) (95% confidence interval, 3-31). Most patients had PSA progression, almost half had radiographic progression, but only 1 patient had symptomatic progression. Eleven (44%) of 25 patients had grade 1 and 2 patients each grade 2 (8%) or grade 3 (8%) gastrointestinal toxicity (nausea, diarrhea, loss of appetite). One patient discontinued treatment at week 5 because of intolerable grade 3 diarrhea.

Conclusion

The addition of metformin to abiraterone for patients with metastatic castration-resistant prostate cancer and PSA progression while receiving abiraterone therapy does not affect further progression and has no meaningful clinical benefit. A higher-than-expected gastrointestinal toxicity attributed to metformin was observed.  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