全文获取类型
收费全文 | 6446篇 |
免费 | 719篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 153篇 |
妇产科学 | 115篇 |
基础医学 | 893篇 |
口腔科学 | 103篇 |
临床医学 | 809篇 |
内科学 | 1599篇 |
皮肤病学 | 241篇 |
神经病学 | 554篇 |
特种医学 | 382篇 |
外科学 | 591篇 |
综合类 | 90篇 |
一般理论 | 2篇 |
预防医学 | 891篇 |
眼科学 | 55篇 |
药学 | 351篇 |
中国医学 | 3篇 |
肿瘤学 | 333篇 |
出版年
2023年 | 75篇 |
2022年 | 35篇 |
2021年 | 73篇 |
2020年 | 94篇 |
2019年 | 81篇 |
2018年 | 140篇 |
2017年 | 103篇 |
2016年 | 137篇 |
2015年 | 149篇 |
2014年 | 211篇 |
2013年 | 289篇 |
2012年 | 336篇 |
2011年 | 371篇 |
2010年 | 201篇 |
2009年 | 203篇 |
2008年 | 312篇 |
2007年 | 312篇 |
2006年 | 283篇 |
2005年 | 260篇 |
2004年 | 270篇 |
2003年 | 215篇 |
2002年 | 225篇 |
2001年 | 215篇 |
2000年 | 166篇 |
1999年 | 184篇 |
1998年 | 143篇 |
1997年 | 125篇 |
1996年 | 126篇 |
1995年 | 108篇 |
1994年 | 106篇 |
1993年 | 85篇 |
1992年 | 105篇 |
1991年 | 86篇 |
1990年 | 103篇 |
1989年 | 133篇 |
1988年 | 104篇 |
1987年 | 104篇 |
1986年 | 98篇 |
1985年 | 88篇 |
1984年 | 55篇 |
1983年 | 53篇 |
1982年 | 47篇 |
1981年 | 49篇 |
1979年 | 52篇 |
1978年 | 32篇 |
1977年 | 41篇 |
1976年 | 41篇 |
1975年 | 34篇 |
1973年 | 34篇 |
1971年 | 38篇 |
排序方式: 共有7197条查询结果,搜索用时 78 毫秒
31.
32.
Petra Mullner Simon E.F. Spencer Daniel J. Wilson Geoff Jones Alasdair D. Noble Anne C. Midwinter Julie M. Collins-Emerson Philip Carter Steve Hathaway Nigel P. French 《Infection, genetics and evolution》2009,9(6):1311-1319
Integrated surveillance of infectious multi-source diseases using a combination of epidemiology, ecology, genetics and evolution can provide a valuable risk-based approach for the control of important human pathogens. This includes a better understanding of transmission routes and the impact of human activities on the emergence of zoonoses. Until recently New Zealand had extraordinarily high and increasing rates of notified human campylobacteriosis, and our limited understanding of the source of these infections was hindering efforts to control this disease. Genetic and epidemiological modeling of a 3-year dataset comprising multilocus sequence typed isolates from human clinical cases, coupled with concurrent data on food and environmental sources, enabled us to estimate the relative importance of different sources of human disease. Our studies provided evidence that poultry was the leading cause of human campylobacteriosis in New Zealand, causing an estimated 58–76% of cases with widely varying contributions by individual poultry suppliers. These findings influenced national policy and, after the implementation of poultry industry-specific interventions, a dramatic decline in human notified cases was observed in 2008. The comparative-modeling and molecular sentinel surveillance approach proposed in this study provides new opportunities for the management of zoonotic diseases. 相似文献
33.
Braun Ralph P. MD Klumb Francis PhD † Bondon David PhD † Salomon Denis MD Skaria Andreas MD Adatto Maurice MD French Lars E. MD Saurat Jean-Hilaire MD Vallée Jean-Paul MD † 《Dermatologic surgery》2005,31(5):562-569
BACKGROUND: Basal cell carcinoma (BCC) is the most common type of skin cancer. One of the main problems with BCC is the risk of local recurrence of the tumor after treatment. This is mainly due to its irregular outgrowths, which cannot be detected clinically. OBJECTIVE: To better understand the tumor morphology and growth pattern of BCC, we tried to develop a method that provides a precise three-dimensional model of the tumor. METHODS: Because Mohs surgery provides the best overview of the tumor and the tumor margins (both lateral and in depth), the reconstruction was based on slides from Mohs surgery. After digitization and processing of the slides, the tumor was then surrounded by a Mohs surgeon on a computer screen. These selections (lines) were used for a three-dimensional reconstruction of the tumor using MedSurf3D software. RESULTS: This method allows three-dimensional reconstruction of any given BCC. The MedSurf3D software enables visualization of a three-dimensional model of the tissue, which is removed during the surgical procedure. CONCLUSIONS: Three-dimensional reconstruction is a fascinating tool that might improve our understanding of the behavior, growth pattern, and tumor morphology of BCCs. This technique might also be useful in other fields of cutaneous oncology, such as the calculation of the tumor volume of melanomas. 相似文献
34.
SIR, We appreciate the comments of Kleiman et al., which serveto 相似文献
35.
French Donna L. Häglund Bert O. Himmelstein Kenneth J. Mauger John W. 《Pharmaceutical research》1995,12(10):1513-1520
Purpose. The objective of this study is to correlate drug release mechanism with measured drug concentration profiles in gel layers of Carbopol® matrices containing mesalamine or benzoic acid.
Methods. Release rate experiments with Carbopol® matrices were performed using a rotating disk apparatus. Matrices were frozen and the gel layer in the matrices was sliced using a microtome in a cryostat. Drug concentration profiles were determined by direct measurement of the concentration of the drug in the gel slices. The pH of the slices was measured using microelectrodes, and water content was measured by Karl Fisher titration.
Results. The concentration gradient in mesalamine matrices decreased over time and correlated with square root of time release rate kinetics. The concentration profiles of benzoic acid were unchanged over time and correlated with zero order release rate kinetics. Carbopol gel layers were highly hydrated (93–95% water). Gel layers in matrices with mesalamine had a more alkaline microenvironmental pH. This higher pH resulted in increased growth of the thickness of the gel layer and a reduction drug diffusivity in comparison to benzoic acid matrices.
Conclusions. The release rate kinetics of mesalamine and benzoic acid correlated to the measured concentration profiles. The shape of the concentration profiles is determined by the rate of growth of the Carbopol® gel layer and drug diffusivity. 相似文献
36.
D T Leung R Y Tseng S H Go G L French C W Lam 《Archives of disease in childhood》1987,62(10):1075-1076
Of 74 paediatric inpatients with acute glomerulonephritis, 58 (78%) had a raised (greater than 1/200) antistreptolysin O titre. Serum C3 concentration was low in 73, but returned to normal within six weeks. Streptococcal infection remains the commonest cause of acute nephritis in children in Hong Kong, possibly due to overcrowded living conditions. 相似文献
37.
38.
39.
40.
H G French S W Burke J M Roberts C E Johnston T Whitecloud J O Edmunds 《Journal of pediatric orthopedics》1987,7(1):69-71
Six patients with upper cervical spine ossicles and Down syndrome from a study population of 184 are described. The average age was 20.6 years at the time of diagnosis. Three of the patients were involved in tumbling. Radiographic anatomy of the ossicles and the dens, as well as serial radiographs in three of the six patients, suggest that this represents an avulsion of the upper end of the dens rather than an occipital vertebrae, ossiculum terminale, or os odontoideum, as previously described. The authors advocate restriction of high-risk activities for all patients with Down syndrome. 相似文献