全文获取类型
收费全文 | 24199篇 |
免费 | 2699篇 |
国内免费 | 67篇 |
专业分类
耳鼻咽喉 | 215篇 |
儿科学 | 793篇 |
妇产科学 | 614篇 |
基础医学 | 3501篇 |
口腔科学 | 590篇 |
临床医学 | 2962篇 |
内科学 | 4111篇 |
皮肤病学 | 418篇 |
神经病学 | 1948篇 |
特种医学 | 799篇 |
外国民族医学 | 3篇 |
外科学 | 3164篇 |
综合类 | 514篇 |
一般理论 | 29篇 |
预防医学 | 3043篇 |
眼科学 | 412篇 |
药学 | 1964篇 |
中国医学 | 100篇 |
肿瘤学 | 1785篇 |
出版年
2021年 | 274篇 |
2020年 | 216篇 |
2019年 | 310篇 |
2018年 | 431篇 |
2017年 | 279篇 |
2016年 | 325篇 |
2015年 | 404篇 |
2014年 | 545篇 |
2013年 | 762篇 |
2012年 | 1128篇 |
2011年 | 1184篇 |
2010年 | 667篇 |
2009年 | 627篇 |
2008年 | 1042篇 |
2007年 | 1098篇 |
2006年 | 1161篇 |
2005年 | 1116篇 |
2004年 | 1037篇 |
2003年 | 990篇 |
2002年 | 972篇 |
2001年 | 844篇 |
2000年 | 846篇 |
1999年 | 770篇 |
1998年 | 343篇 |
1997年 | 286篇 |
1996年 | 315篇 |
1995年 | 291篇 |
1994年 | 250篇 |
1993年 | 227篇 |
1992年 | 606篇 |
1991年 | 511篇 |
1990年 | 506篇 |
1989年 | 453篇 |
1988年 | 435篇 |
1987年 | 451篇 |
1986年 | 442篇 |
1985年 | 396篇 |
1984年 | 318篇 |
1983年 | 258篇 |
1982年 | 212篇 |
1981年 | 197篇 |
1980年 | 187篇 |
1979年 | 289篇 |
1978年 | 221篇 |
1977年 | 189篇 |
1976年 | 170篇 |
1975年 | 171篇 |
1974年 | 199篇 |
1973年 | 195篇 |
1972年 | 193篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Metabolism describes the series of chemical reactions that are concerned with the provision of energy to biological systems. They may be divided into reactions involved in energy yield (catabolism: demand exceeds supply), and energy storage (anabolism: supply exceeds demand). Regulation of these pathways is critical for homeostasis, and derangements in metabolism are seen in a wide variety of pathological processes. Understanding metabolism is key to the treatment of many diseases, notably diabetes, as well as underpinning clinical nutritional support. 相似文献
2.
Monique G. Kumar M.Phil. M.D. Heather Ciliberto M.D. Susan J. Bayliss M.D. 《Pediatric dermatology》2015,32(2):198-200
Pediatric trachyonychia is an acquired nail disease that can cause distress to families. It is a poorly understood disease, and long‐term follow‐up data are lacking. We present an institutional review of 11 children with isolated pediatric trachyonychia followed over time. Children with the diagnosis of pediatric trachyonychia were identified and invited to participate. Pictures were taken on follow‐up and a questionnaire was answered. Exclusion criteria include having another diagnosis at the initial visit that causes nail dystrophy. Eleven patients with the diagnosis of pediatric trachyonychia were available for follow‐up. The mean age of appearance was 2.7 years (range 2–7 yrs) and the average follow‐up was 66 months (range 10–126 mos). Nine patients were treated with potent topical corticosteroids, one used only petrolatum, and one took vitamin supplements. One patient was found to have an additional skin and hair diagnosis of alopecia areata on follow‐up. On follow‐up, 82% noted improvement of the nails, whereas 18% noted no change. A majority of cases of pediatric trachyonychia are isolated and improve with time, regardless of treatment. 相似文献
3.
4.
Nicola Flaum Emma J. Crosbie Richard J. Edmondson Miriam J. Smith Dafydd G. Evans 《Clinical genetics》2020,97(1):54-63
Ovarian cancer is the fourth most common cause of cancer-related death in women in the developed world, and one of the most heritable cancers. One of the most significant risk factors for epithelial ovarian cancer (EOC) is a family history of breast and/or ovarian cancer. Combined risk factors can be used in models to stratify risk of EOC, and aid in decisions regarding risk-reduction strategies. Germline pathogenic variants in EOC susceptibility genes including those involved in homologous recombination and mismatch repair pathways are present in approximately 22% to 25% of EOC. These genes are associated with an estimated lifetime risk of EOC of 13% to 60% for BRCA1 variants and 10% to 25% for BRCA2 variants, with lower risks associated with remaining genes. Genome-wide association studies have identified single nucleotide polymorphisms (SNPs) thought to explain an additional 6.4% of the familial risk of ovarian cancer, with 34 susceptibility loci identified to date. However, an unknown proportion of the genetic component of EOC risk remains unexplained. This review comprises an overview of individual genes and SNPs suspected to contribute to risk of EOC, and discusses use of a polygenic risk score to predict individual cancer risk more accurately. 相似文献
5.
Tarentola annularis is a climbing gecko with a wide distribution in Africa north of the equator. In the present paper, we describe the development of the osteocranium of this lizard, from the first appearance of the cranial elements up to the point of hatching. This is based on a combination of histology and cleared and stained specimens. This is the first comprehensive account of gekkotan pre-hatching skull development based on a comprehensive series of embryos, rather than a few selected stages. Given that Gekkota is now widely regarded as representing the sister group to other squamates, this account helps to fill a significant gap in the literature. Moreover, as many authors have considered features of the gekkotan skull and skeleton to be indicative of paedomorphosis, it is important to know whether this hypothesis is supported by delays in the onset of cranial ossification. In fact, we found the sequence of cranial bone ossification to be broadly comparable to that of other squamates studied to date, with no significant lags in development. 相似文献
6.
7.
8.
Rachel P. Winograd Ned Presnall Erin Stringfellow Claire Wood Phil Horn Alex Duello 《The American journal of drug and alcohol abuse》2019,45(4):333-340
Background: The opioid addiction and overdose crisis continues to ravage communities across the U.S. Maintenance pharmacotherapy using buprenorphine or methadone is the most effective intervention for Opioid Use Disorder (OUD), yet few have immediate and sustained access to these medications. Objectives: To address lack of medication access for people with OUD, the Missouri Department of Mental Health began implementing a Medication First (Med First) treatment approach in its publicly-funded system of comprehensive substance use disorder treatment programs. Methods: This Perspective describes the four principles of Med First, which are based on evidence-based guidelines. It draws conceptual comparisons between the Housing First approach to chronic homelessness and the Med First approach to pharmacotherapy for OUD, and compares state certification standards for substance use disorder (SUD) treatment (the traditional approach) to Med First guidelines for OUD treatment. Finally, the Perspective details how Med First principles have been practically implemented. Results: Med First principles emphasize timely access to maintenance pharmacotherapy without requiring psychosocial services or discontinuation for any reason other than harm to the client. Early results regarding medication utilization and treatment retention are promising. Feedback from providers has been largely favorable, though clinical- and system-level obstacles to effective OUD treatment remain. Conclusion: Like the Housing First model, Medication First is designed to decrease human suffering and activate the strengths and capacities of people in need. It draws on decades of research and facilitates partnerships between psychosocial and medical treatment providers to offer effective and life-saving care to persons with OUD. 相似文献
9.
10.
Peter Marhofer Malachy Columb Phil M. Hopkins Manfred Greher Daniela Marhofer Max R. Levi Bienzle Markus Zeitlinger 《British journal of anaesthesia》2019,122(4):525-531