全文获取类型
收费全文 | 3193篇 |
免费 | 221篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 28篇 |
儿科学 | 129篇 |
妇产科学 | 56篇 |
基础医学 | 403篇 |
口腔科学 | 44篇 |
临床医学 | 284篇 |
内科学 | 706篇 |
皮肤病学 | 96篇 |
神经病学 | 168篇 |
特种医学 | 185篇 |
外科学 | 289篇 |
综合类 | 266篇 |
预防医学 | 362篇 |
眼科学 | 40篇 |
药学 | 215篇 |
1篇 | |
中国医学 | 14篇 |
肿瘤学 | 143篇 |
出版年
2023年 | 25篇 |
2022年 | 45篇 |
2021年 | 86篇 |
2020年 | 46篇 |
2019年 | 63篇 |
2018年 | 68篇 |
2017年 | 52篇 |
2016年 | 67篇 |
2015年 | 121篇 |
2014年 | 152篇 |
2013年 | 164篇 |
2012年 | 190篇 |
2011年 | 190篇 |
2010年 | 121篇 |
2009年 | 86篇 |
2008年 | 155篇 |
2007年 | 143篇 |
2006年 | 143篇 |
2005年 | 121篇 |
2004年 | 106篇 |
2003年 | 107篇 |
2002年 | 110篇 |
2001年 | 82篇 |
2000年 | 84篇 |
1999年 | 79篇 |
1998年 | 35篇 |
1997年 | 43篇 |
1996年 | 40篇 |
1995年 | 39篇 |
1994年 | 40篇 |
1993年 | 28篇 |
1992年 | 41篇 |
1991年 | 40篇 |
1990年 | 29篇 |
1989年 | 36篇 |
1988年 | 35篇 |
1987年 | 24篇 |
1986年 | 36篇 |
1985年 | 44篇 |
1984年 | 26篇 |
1983年 | 17篇 |
1981年 | 16篇 |
1980年 | 19篇 |
1979年 | 16篇 |
1978年 | 13篇 |
1977年 | 15篇 |
1976年 | 17篇 |
1975年 | 12篇 |
1974年 | 18篇 |
1973年 | 31篇 |
排序方式: 共有3429条查询结果,搜索用时 15 毫秒
11.
12.
13.
The serum ceruloplasmin concentration was determined in cancer patients before and after radiotherapy, and after relapse of cancer, The ceruloplasmin concentration in patients who responded to therapy, decreased to the range of normal controls. In patients who did not respond to treatment, the ceruloplasmin concentration was more or less elevated. In patients with relapse of cancer, the ceruloplasmin concentration was higher than before treatment. 相似文献
14.
15.
T Ohdaira T Kobayashi M Tanaka M F Chowdhury B Ahn A Masuda Y Sakakibara Y Honda 《The Japanese journal of physiology》1992,42(5):765-777
Recent investigations have shown that the calcium channel blocker verapamil attenuated the hypoxic ventilatory chemosensitivity of carotid body in animals. To determine whether this is also the case in humans, transient physiological chemodenervation by O2 breaths (withdrawal test) during sustained hypoxia (N = 7), and ventilatory and circulatory responses to progressive hypoxia and hypercapnia (N = 8) were examined after oral administration of verapamil. During sustained hypoxia after verpamil, there was a significant reduction of withdrawal response from 5th to 25th min value (p < 0.01), but not after placebo. On the other hand, no significant difference in ventilatory responses to progressive hypoxia and hypercapnia was observed after verapamil. Verapamil run reveals similar features with placebo run in circulatory parameters except blood pressure response, which tended to be suppressed by verapamil. We conclude that verapamil attenuates peripheral chemoreceptor activity with time during sustained mild hypoxia in normal adult humans and this may be explained by delayed depletion in intracellular Ca2+ for chemotransduction of the peripheral chemoreceptors. 相似文献
16.
Regulation of immunoglobulin heavy-chain gene rearrangements 总被引:1,自引:0,他引:1
Summary: Regulated assembly of antigen receptor gene segments to produce functional genes is a hallmark of B‐ and T‐lymphocyte development. The immunoglobulin heavy‐chain (IgH) and T‐cell receptor β‐chain genes rearrange first in B and T lineages, respectively. Both loci require two recombination events to assemble functional genes; D‐to‐J recombination occurs first followed by V‐to‐DJ recombination. Despite similarities in overall rearrangement patterns, each locus has unique regulatory features. Here, we review the characteristics of IgH gene rearrangements such as developmental timing, deletion versus inversion, DH gene segment utilization, ordered recombination of VH gene segments, and feedback inhibition of rearrangement in pre‐B cells. We summarize chromatin structural features of the locus before and during recombination and, wherever possible, incorporate these into working hypotheses for understanding regulation of IgH gene recombination. The picture emerges that the IgH locus is activated in discrete, independently regulated domains. A domain encompassing DH and JH gene segments is activated first, within which recombination is initiated. VH genes are activated subsequently and, in part, by interleukin‐7. These observations lead to a model for feedback inhibition of IgH rearrangements. 相似文献
17.
Over a five-year period, 197 hysterectomies were performed at King Khalid University Hospital (KKUH). Indications for the procedures vary from menstrual disorders and symptomatic fibroids to ovarian malignancy. The most common indication was found to be menorrhagia. Among multiple pre-operative indications, only the first listed major indication for hysterectomy was chosen. There were 145 abdominal and 52 vaginal hysterectomies and all were elective gynaecological procedures, majority of which were performed on women in their fourth and fifth decades of life. Verification of pre-operative diagnosis, when correlated with pathological findings, showed that some of the indications for the procedure deserve a more critical reappraisal. Since hysterectomy carries substantial economic and medical consequences, indications for undertaking the procedure deserve more careful scrutiny given the surgical and nonsurgical options that are currently available. There may be a need, therefore, to assess the appropriateness or otherwise of the use of hysterectomy in many of the patients in future. 相似文献
18.
19.
20.
V Fauveau B Wojtyniak M A Koenig J Chakraborty A I Chowdhury 《International journal of epidemiology》1989,18(1):139-145
A total of 542 women aged 15 to 44 years died during the 10-year period 1976 to 1985 in the control area of Matlab, an area with a population of 90,000, representative of many other rural areas of southern Bangladesh. The corresponding age-specific mortality rate was 290 per 100,000 women 15-44 years. These deaths have been analysed retrospectively, using information collected through the Demographic Surveillance System set up by the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B) and verbal autopsies conducted in the homes. Of these deaths, 175 (32%) were due to infectious diseases, 163 (30%) to direct obstetric complications, 67 (12%) to injuries, and the remaining 26% to other causes. Cause-specific and proportionate mortality rates showed a positive association with age for deaths due to infectious diseases, non-infectious diseases and unspecified causes, and an inverse association with age for deaths due to injuries. These rates showed a peak in the intermediate age group 25 to 34 years for deaths due to direct obstetric causes. No consistent trends were visible when annual rates were studied over time. Prior to death, 42% of the women were attended by traditional practitioners, and 33% were not attended at all. Demographic impact is discussed, emphasizing the contribution of obstetric causes to overall mortality. Priorities for health policy implications are proposed, focusing upon a strong maternity care programme, and improved availability of female health personnel, in the context of the socio-cultural constraints imposed on women in poor rural areas. 相似文献