全文获取类型
收费全文 | 6050篇 |
免费 | 419篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 28篇 |
儿科学 | 151篇 |
妇产科学 | 122篇 |
基础医学 | 1224篇 |
口腔科学 | 140篇 |
临床医学 | 490篇 |
内科学 | 1290篇 |
皮肤病学 | 96篇 |
神经病学 | 505篇 |
特种医学 | 368篇 |
外国民族医学 | 1篇 |
外科学 | 743篇 |
综合类 | 50篇 |
一般理论 | 3篇 |
预防医学 | 274篇 |
眼科学 | 114篇 |
药学 | 444篇 |
中国医学 | 4篇 |
肿瘤学 | 454篇 |
出版年
2021年 | 85篇 |
2020年 | 56篇 |
2019年 | 66篇 |
2018年 | 77篇 |
2017年 | 70篇 |
2016年 | 72篇 |
2015年 | 110篇 |
2014年 | 138篇 |
2013年 | 194篇 |
2012年 | 251篇 |
2011年 | 257篇 |
2010年 | 164篇 |
2009年 | 154篇 |
2008年 | 232篇 |
2007年 | 242篇 |
2006年 | 245篇 |
2005年 | 221篇 |
2004年 | 191篇 |
2003年 | 222篇 |
2002年 | 211篇 |
2001年 | 166篇 |
2000年 | 198篇 |
1999年 | 185篇 |
1998年 | 86篇 |
1997年 | 71篇 |
1996年 | 62篇 |
1995年 | 49篇 |
1994年 | 59篇 |
1992年 | 115篇 |
1991年 | 103篇 |
1990年 | 129篇 |
1989年 | 114篇 |
1988年 | 108篇 |
1987年 | 97篇 |
1986年 | 111篇 |
1985年 | 120篇 |
1984年 | 60篇 |
1983年 | 48篇 |
1981年 | 49篇 |
1979年 | 75篇 |
1978年 | 58篇 |
1977年 | 49篇 |
1975年 | 65篇 |
1973年 | 55篇 |
1972年 | 54篇 |
1971年 | 52篇 |
1970年 | 54篇 |
1969年 | 64篇 |
1968年 | 52篇 |
1966年 | 48篇 |
排序方式: 共有6501条查询结果,搜索用时 15 毫秒
1.
A high resolution depth attenuation product (Kdhires) was developed using MODIS 500 m and 250 m spectral bands. The Kdhires was compared with Wang’s operational Kd for the Chesapeake Bay. Minimal differences were observed between the two methods, with greatest deviation occurring in areas of high turbidity in the tributaries. After tuning the new Kdhires, the mean absolute error and bias between the two algorithms was 0.22 m?1 and 0.026 m?1, indicating good agreement. Higher spatial resolution provides for improved retrievals along the coast and into the narrow sections of the tributaries, coinciding with areas of concern to estuarine health and coastal management applications. 相似文献
2.
3.
Maternal factors influencing development of embryos from mice superovulated with gonadotropins 总被引:5,自引:0,他引:5
In NMRI mice superovulation with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) increased mating rate, number of implantation sites, rate of advanced and delayed resorptions, as well as retarded sternebral ossification and cleft palate. On day 3 of gestation in preimplantation embryos, cell number and mitotic index were lower after superovulation than after spontaneous ovulation. However, when preimplantation embryos from superovulated and control females were transferred on day 3 of pregnancy to pseudopregnant recipients (10 embryos per female) no differences could be detected between the two groups of fetuses at term. The results of the embryo transfer experiments indicate that abnormal embryonic development after superovulation with gonadotropins is predominantly induced by effects of the hormone treatment on the maternal uterine environment. 相似文献
4.
Torsten T. Bauer Joachim Lorenz Klaus-Friedrich Bodmann Friedrich Vogel 《Medizinische Klinik》2005,26(13):355-360
Hintergrund:
Die nosokomiale Pneumonie gehört zu den häufigsten nosokomialen Infektionen und ist die häufigste auf der Intensivstation. Die nosokomiale Pneumonie ist mit einer signifikanten Mortalität und Morbidität assoziiert, und ihr Auftreten verschlechtert die Prognose des Patienten deutlich. Nach der Definition der DRGs auch im deutschen Krankenhaussystem ist die nosokomiale Pneumonie überwiegend Sache des Krankenhauses und kann somit nicht nur das Ergebnis der Patientenbehandlung, sondern auch das finanzielle Ergebnis des Krankenhauses beeinträchtigen. 相似文献5.
C. Fischer W. Gross J. Krüger M. Cremer F. Vogel T. Grimm 《Annals of human genetics》2006,70(2):237-248
For several genetic diseases two biological phenomena have been recognised as important: germline mosaicism; and different new mutation rates in males and females depending on mutation type. Both principles have been investigated separately and their influence on risk estimation in families has been exemplified in the literature. The aim of this paper is to present a general model that includes mosaicism and different new mutation rates. Mosaicism is introduced by defining additional alleles at the disease locus in combination with adapted segregation rules. Taking Duchenne muscular dystrophy as an example, we derive the conditions which have to be fulfilled for a population in mutation selection equilibrium. Our approach describes the model at the population level and not in individual subjects. This has the advantage of being able to use well known algorithms for the calculation of likelihoods in pedigrees, and to include additional diagnostic information such as marker genotypes and carrier deletion test results. We demonstrate the impact of the new model on a typical pedigree. In families where the patient is not available, the distinction between point mutations and deletions is important, since often molecular diagnostic tests for females can only screen for deletions. Negative deletion test results can now be included in the risk calculations. 相似文献
6.
7.
Lotus footdrop: sciatic neuropathy in the thigh 总被引:1,自引:0,他引:1
8.
A 37-year-old Italian male developed a myocardial infarct with subsequent ventricular fibrillation. He was defibrillated
seven times with up to 360 Joules. Thirteen days later the patient died of recurrent myocardial infarct due to thrombotic
occlusion of the left circumflex coronary artery. At autopsy, necrosis of the right pectoralis muscle was observed. Electroporation
is the pathogenetic mechanism of skeletal muscle damage due to multiple defibrillations with high energy levels.
Received: 8 January 1998 Accepted: 15 April 1998 相似文献
9.
10.
Scoliosis in pediatric spinal cord-injured patients 总被引:1,自引:0,他引:1
W W Dearolf R R Betz L C Vogel J Levin M Clancy H H Steel 《Journal of pediatric orthopedics》1990,10(2):214-218
One hundred thirty children who sustained spinal cord injuries between birth and age 21 years were reviewed to determine the progression rate of paralytic scoliosis and the effects of bracing and surgery. Patients were divided into two groups: those injured before and those injured after the adolescent growth spurt. Scoliosis developed in 97 and 52%, respectively. Bracing was effective in delaying progression in the preadolescent group. The progressive paralytic spinal deformity did not appear to be related to the level of injury. The older patient is at much less risk for paralytic scoliosis, but still requires routine examination. 相似文献