全文获取类型
收费全文 | 1209篇 |
免费 | 63篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 86篇 |
妇产科学 | 12篇 |
基础医学 | 124篇 |
口腔科学 | 25篇 |
临床医学 | 184篇 |
内科学 | 264篇 |
皮肤病学 | 19篇 |
神经病学 | 27篇 |
特种医学 | 306篇 |
外科学 | 73篇 |
综合类 | 11篇 |
预防医学 | 30篇 |
眼科学 | 7篇 |
药学 | 45篇 |
肿瘤学 | 68篇 |
出版年
2023年 | 2篇 |
2021年 | 10篇 |
2020年 | 7篇 |
2019年 | 5篇 |
2018年 | 15篇 |
2017年 | 4篇 |
2016年 | 8篇 |
2015年 | 18篇 |
2014年 | 20篇 |
2013年 | 27篇 |
2012年 | 16篇 |
2011年 | 17篇 |
2010年 | 34篇 |
2009年 | 34篇 |
2008年 | 16篇 |
2007年 | 35篇 |
2006年 | 21篇 |
2005年 | 30篇 |
2004年 | 26篇 |
2003年 | 14篇 |
2002年 | 15篇 |
2001年 | 13篇 |
2000年 | 18篇 |
1999年 | 22篇 |
1998年 | 95篇 |
1997年 | 72篇 |
1996年 | 78篇 |
1995年 | 56篇 |
1994年 | 54篇 |
1993年 | 61篇 |
1992年 | 14篇 |
1991年 | 8篇 |
1990年 | 21篇 |
1989年 | 46篇 |
1988年 | 32篇 |
1987年 | 47篇 |
1986年 | 30篇 |
1985年 | 32篇 |
1984年 | 26篇 |
1983年 | 19篇 |
1982年 | 22篇 |
1981年 | 24篇 |
1980年 | 28篇 |
1979年 | 9篇 |
1978年 | 16篇 |
1977年 | 19篇 |
1976年 | 21篇 |
1975年 | 16篇 |
1974年 | 3篇 |
1930年 | 1篇 |
排序方式: 共有1283条查询结果,搜索用时 15 毫秒
1.
C Vassanelli G Menegatti B Silverstein P Zardini R Cubeddu V Russo O Svelto 《Lasers in surgery and medicine》1987,7(1):23-28
Percutaneous transluminal balloon angioplasty (PTA) is being currently used in patients with coronary artery disease. Laser irradiation (LI) has been effective in vaporizing atherosclerotic plaques. The purpose of this work was twofold: to compare PTA and LI techniques in the recanalization of experimental obstructive arterial lesions, and to evaluate the possibility of reducing the failures and local complications and increasing the success rate of PTA by the combined use of LI. Atherosclerotic iliac stenoses were induced in 27 rabbits; lesions were evaluated angiographically before and after intervention and were studied histologically and by electron microscopy. Argon-ion LI delivered through microlens-tip optic fibers reduced the stenotic area from 64.2 +/- 21.8% to 40.3 +/- 10.7% (n = 10, P less than .01) and PTA from 60.7 +/- 15.9% to 30.4 +/- 7.7% (n = 9, P less than .01). However, percentage reduction was higher in PTA-treated stenoses (48.4 +/- 10.1% vs 34.5 +/- 13.5%, P less than .0125). In eight more rabbits, low power LI (4.55 +/- 1.25 J) was delivered after PTA in dilated segments. Post-PTA LI further decreased stenoses (from 31.2 +/- 7.8% to 29.1 +/- 8.1%, P less than .0125); laser-irradiated segments showed diffuse carbonization of the disrupted intimal layer. The normalized transtenotic pressure gradient decreased significantly in all groups: LI reduced the gradient from .40 +/- .25 to .17 +/- .07 (P = .005); PTA from .37 +/- .14 to .11 +/- .04 (P = .001); LI after PTA from .40 +/- .16 to .12 +/- .06 (P = .001). Thus, LI is effective (less than PTA) in relieving experimental atherosclerotic stenoses and seems useful when combined with PTA. 相似文献
2.
3.
To test the role of serotonin in chemotherapy-induced nausea and emesis, ten cancer patients were pretreated with the serotonin synthesis inhibitor para-chlorophenylalanine (PCPA). PCPA (2 g 8 hourly for 2 or 3 days prior to cisplatin) reduced the spontaneous urinary excretion of 5-hydroxyindoleacetic acid (5-HIAA), inhibited the increase in urinary 5-HIAA induced by cisplatin and markedly attenuated the acute period of nausea and vomiting associated with the cytotoxic drug. These results indicate that gastrointestinal serotonin mediates cisplatin-induced emesis and that the amount of serotonin released by cisplatin is a major factor in determining the severity of the acute period of emesis experienced by the patient. 相似文献
4.
5.
6.
7.
8.
9.
Competitive control of the self-renewing T cell repertoire 总被引:1,自引:0,他引:1
We develop a mathematical model for the self-renewing part of the T cell
repertoire. Assuming that self-renewing T cells have to be stimulated by
immunogenic MHC-peptide complexes presented on the surfaces of
antigen-presenting cells, we derive a model of T cell growth in which
competition for MHC-peptide complexes limits T cell clone sizes and
regulates the total number of self-renewing T cells in the animal. We show
that for a sufficient diversity and/or degree of cross-reactivity, the
total T cell number hardly depends upon the diversity of the T cell
repertoire or the diversity of the set of presented peptides. Conversely,
for repertoires of lower diversity and/or cross-reactivity, steady-state
total T cell numbers may be limited by the diversity of the T cells. This
provides a possible explanation for the limited repertoire expansion in
some, but not all, mouse T cell re-constitution experiments. We suggest
that the competitive interactions described by our model underlie the
normal T cells numbers observed in transgenic mice, germ-free mice and
various knockout mice.
相似文献
10.
Localization of a gene for otosclerosis to chromosome 15q25-q26 总被引:5,自引:0,他引:5
Tomek MS; Brown MR; Mani SR; Ramesh A; Srisailapathy CR; Coucke P; Zbar RI; Bell AM; McGuirt WT; Fukushima K; Willems PJ; Van Camp G; Smith RJ 《Human molecular genetics》1998,7(2):285-290
Among white adults otosclerosis is the single most common cause of hearing
impairment. Although the genetics of this disease are controversial, the
majority of studies indicate autosomal dominant inheritance with reduced
penetrance. We studied a large multi- generational family in which
otosclerosis has been inherited in an autosomal dominant pattern. Five of16
affected persons have surgically confirmed otosclerosis; the remaining nine
have a conductive hearing loss but have not undergone corrective surgery.
To locate the disease- causing gene we completed genetic linkage analysis
using short tandem repeat polymorphisms (STRPs) distributed over the entire
genome. Multipoint linkage analysis showed that only one genomic region, on
chromosome 15q, generated a lod score >2.0. Additional STRPs were typed
in this area, resulting in a lod score of 3.4. STRPs FES (centromeric) and
D15S657 (telomeric) flank the 14. 5 cM region that contains an otosclerosis
gene.
相似文献