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   10482篇
  免费   592篇
  国内免费   30篇
耳鼻咽喉   102篇
儿科学   206篇
妇产科学   302篇
基础医学   1737篇
口腔科学   230篇
临床医学   869篇
内科学   2036篇
皮肤病学   252篇
神经病学   1382篇
特种医学   489篇
外国民族医学   1篇
外科学   1102篇
综合类   55篇
一般理论   3篇
预防医学   752篇
眼科学   144篇
药学   813篇
中国医学   23篇
肿瘤学   606篇
  2021年   192篇
  2020年   124篇
  2019年   185篇
  2018年   197篇
  2017年   189篇
  2016年   243篇
  2015年   298篇
  2014年   362篇
  2013年   427篇
  2012年   690篇
  2011年   647篇
  2010年   406篇
  2009年   363篇
  2008年   543篇
  2007年   572篇
  2006年   576篇
  2005年   524篇
  2004年   463篇
  2003年   423篇
  2002年   421篇
  2001年   247篇
  2000年   241篇
  1999年   233篇
  1998年   96篇
  1997年   67篇
  1995年   62篇
  1994年   51篇
  1992年   96篇
  1991年   75篇
  1990年   96篇
  1989年   119篇
  1988年   111篇
  1987年   91篇
  1986年   108篇
  1985年   110篇
  1984年   70篇
  1983年   64篇
  1981年   49篇
  1979年   85篇
  1978年   59篇
  1977年   61篇
  1976年   51篇
  1975年   56篇
  1974年   50篇
  1973年   74篇
  1972年   60篇
  1971年   77篇
  1970年   57篇
  1969年   59篇
  1968年   51篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
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   
3.
4.
5.
The global plastic production is reaching new altitudes every year. Growing production of petroleum-based plastics has incurred in disposal issues raising the concerns of plastic pollution and impact to the environment. These issues have encouraged innovation and research activities in the field of bioplastics, offering alternatives for conventional plastics. In recent years, global bioplastic production has also witnessed tremendous growth and expansion. Some of the main drivers of this growth are innovative biopolymers such as Polylactic acid (PLA) and Polyhydroxyalkanoates (PHAs). However, industrial expenses to produce bioplastics are much higher when compared to petroleum-derived plastics (e.g. industrial PHA production is estimated to be 5–10 times more expensive than petroleum-derived polymers). In this regard, globally many researchers have investigated for more environmentally friendly and cost-effective alternatives to produce plastics. One potential option to pursue would be to explore agri-food wastes and by-products for bioplastic production. This would not only reduce the volume of wastes and by-products, but also production costs incurred. This review paper provides an overview of bioplastics, including production methods and possibilities of industrial food waste valorization for bioplastic production.  相似文献   
6.
ABSTRACT

Abortion is legal in South Africa, but negative abortion attitudes remain common and are poorly understood. We used nationally representative South African Social Attitudes Survey data to analyze abortion attitudes in the case of fetal anomaly and in the case of poverty from 2007 to 2016 (n = 20,711; ages = 16+). We measured correlations between abortion attitudes and these important predictors: religiosity, attitudes about premarital sex, attitudes about preferential hiring and promotion of women, and attitudes toward family gender roles. Abortion acceptability for poverty increased over time (b = 0.05, p < .001), but not for fetal anomaly (b = ?0.008, p = .284). Highly religious South Africans reported lower abortion acceptability in both cases (Odds Ratio (OR)anomaly = 0.85, p = .015; ORpoverty = 0.84, p = .02). Premarital sex acceptability strongly and positively predicted abortion acceptability (ORanomaly = 2.63, p < .001; ORpoverty = 2.46, p < .001). Attitudes about preferential hiring and promotion of women were not associated with abortion attitudes, but favorable attitudes about working mothers were positively associated with abortion acceptability for fetal anomaly ((ORanomaly = 1.09, p = .01; ORpoverty = 1.02, p = .641)). Results suggest negative abortion attitudes remain common in South Africa and are closely tied to religiosity, traditional ideologies about sexuality, and gender role expectations about motherhood.  相似文献   
7.
8.
9.
10.
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