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   42199篇
  免费   3626篇
  国内免费   1036篇
耳鼻咽喉   434篇
儿科学   1076篇
妇产科学   675篇
基础医学   5781篇
口腔科学   658篇
临床医学   4304篇
内科学   8571篇
皮肤病学   794篇
神经病学   2989篇
特种医学   1562篇
外国民族医学   22篇
外科学   5008篇
综合类   2882篇
现状与发展   4篇
一般理论   3篇
预防医学   3296篇
眼科学   827篇
药学   3448篇
  15篇
中国医学   1171篇
肿瘤学   3341篇
  2023年   381篇
  2022年   882篇
  2021年   1515篇
  2020年   1009篇
  2019年   1111篇
  2018年   1328篇
  2017年   1000篇
  2016年   973篇
  2015年   1263篇
  2014年   1635篇
  2013年   1947篇
  2012年   2793篇
  2011年   2840篇
  2010年   1806篇
  2009年   1454篇
  2008年   2028篇
  2007年   2087篇
  2006年   2014篇
  2005年   1925篇
  2004年   1663篇
  2003年   1620篇
  2002年   1456篇
  2001年   1341篇
  2000年   1310篇
  1999年   1172篇
  1998年   467篇
  1997年   413篇
  1996年   340篇
  1995年   300篇
  1994年   280篇
  1993年   212篇
  1992年   562篇
  1991年   533篇
  1990年   521篇
  1989年   457篇
  1988年   468篇
  1987年   395篇
  1986年   398篇
  1985年   378篇
  1984年   259篇
  1983年   194篇
  1982年   121篇
  1981年   107篇
  1979年   211篇
  1978年   111篇
  1977年   124篇
  1976年   113篇
  1974年   130篇
  1972年   128篇
  1969年   104篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
European Radiology - The strongest adverse prognostic factor in myxoid/round cell liposarcomas (MRC-LPS) is the presence of a round cell component above 5% within the tumor bulk. Its identification...  相似文献   
2.
Introduction: The treatment of classical Hodgkin lymphoma (cHL) in children is a story of success. Nowadays, more than 90% of patients are cured and overall survival is nearly 100% at 5 years. Efforts have been made to avoid related effects of therapies; therefore, children are treated using different chemotherapy schemes in comparison with adults.

Areas covered: This review includes a view of the clinical classification and risk assessment in children suffering from HL. The chemotherapy more commonly employed is revisited. The use of PET/CT to evaluate the disease in order to guide therapy is analyzed. New options of chemotherapy and emerging immunotherapy are also included.

Expert opinion: In order to make the right treatment choice, a proper initial assessment of risk is mandatory. The choice of therapy in these kinds of patients must be done according to the experience of the team, and also, the cost and logistics related to the eligible scheme are very important. If possible, efforts must be made to include PET/CT in guiding therapy and avoiding overtreatment and long-term adverse effects in children. New options in immunotherapy are emerging and must be considered with caution in selected patients.  相似文献   

3.
4.
5.
人类微生物群是由寄生在人体上皮屏障的细菌和其他微生物组成的,其中大部分位于肠道内,与宿主之间形成共生的关系。机体肠道微生物的组成虽然受到年龄、饮食、生活方式等因素的影响,但在正常生理情况下是相对稳定的。近年来,肠道菌群与恶性肿瘤的关系越来越受到重视。肠道菌群不但能够维持局部稳态,还能调节机体代谢、炎症和免疫等生理过程。有研究表明,微生物群,特别是肠道菌群能够显著调节机体对癌症治疗的反应性以及机体对毒副反应的敏感性。检查肠道菌群中各菌种之间的比例可作为筛查恶性肿瘤的新方法。本文将综述微生物群具有影响肿瘤的发生发展、抗肿瘤治疗疗效以及药物不良反应的证据,以及其中所涉及的微生物种类,从而为恶性肿瘤精准治疗提供证据。  相似文献   
6.
7.

Objective

To systematically review literature on uptake and timeliness of diphtheria-tetanus-pertussis, measles-mumps-rubella, and/or polio-containing vaccines in infants who were born preterm, with a low birth weight, and/or with chronic health conditions that were diagnosed within the first 6?months of life.

Methods

Using a standardized search strategy developed by a medical librarian, records were extracted from MEDLINE, Embase, Database of Abstracts of Reviews of Effects, and CINAHL up to May 8, 2018.

Results

Out of the 1997 records that were screened, we identified 21 studies that met inclusion criteria. Eleven studies assessed vaccine coverage and/or timeliness in preterm infants, 6 in low birth weight infants, and 7 in children with chronic health conditions. Estimates of coverage in these populations were highly variable, ranging from 40% to 100% across the vaccines and population groups.

Conclusions

There is a lack of studies reporting coverage and timeliness of routine immunizations in special populations of children.

Policy implications

Our review suggests a need for improved surveillance of immunization status in special populations of infants, as well as a need for standardization of reporting practices.  相似文献   
8.
9.
10.
Background: Palbociclib is a selective cyclin-dependent kinase (CDK) 4/6 inhibitor used in combination with aromatase inhibitors or fulvestrant for patients with hormone receptor-positive (HR+) human epidermal growth factor receptor 2 (HER2)-negative advanced/metastatic breast cancer (ABC/MBC). Palbociclib was the first CDK 4/6 inhibitor approved for HR+/HER2− ABC/MBC treatment in Canada in combination with letrozole (P+L) as an initial endocrine-based therapy (approved March 2016), or with fulvestrant (P+F) following disease progression after prior endocrine therapy (approved May 2017). The Ibrance Real World Insights (IRIS) study (NCT03159195) collected real-world outcomes data for palbociclib-treated patients in several countries, including Canada. Methods: This retrospective chart review included women with HR+/HER2− ABC/MBC receiving P+L or P+F in Canada. Physicians reviewed medical records for up to 14 patients, abstracting demographic and clinical characteristics, treatment patterns, and clinical outcomes. Progression-free rates (PFRs) and survival rates (SRs) at 6, 12, 18, and 24 months were estimated via Kaplan–Meier analysis. Results: Thirty-three physicians examined medical records for 247 patients (P+L, n = 214; P+F, n = 33). Median follow-up was 8.8 months for P+L and 7.0 months for P+F. Most patients were initiated on palbociclib 125 mg/d (P+L, 90.2%; P+F, 84.8%). Doses were reduced in 16.6% of P+L and 14.3% of P+F patients initiating palbociclib at 125 mg/d. The PFR for P+L was 90.3% at 12 months and 78.2% at 18 months; corresponding SRs were 95.6% and 93.0%. For P+F, 6-month PFR was 91.0%; 12-month SR was 100.0%. Conclusions: Dose reduction rates were low and PFR and SR were high in this Canadian real-world assessment of P+L and P+F treatments, suggesting that palbociclib combinations are well tolerated and effective.  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