全文获取类型
收费全文 | 1144篇 |
免费 | 49篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 17篇 |
妇产科学 | 31篇 |
基础医学 | 142篇 |
口腔科学 | 8篇 |
临床医学 | 195篇 |
内科学 | 404篇 |
皮肤病学 | 4篇 |
神经病学 | 32篇 |
特种医学 | 58篇 |
外科学 | 75篇 |
综合类 | 12篇 |
预防医学 | 118篇 |
眼科学 | 4篇 |
药学 | 45篇 |
肿瘤学 | 47篇 |
出版年
2023年 | 5篇 |
2022年 | 4篇 |
2021年 | 13篇 |
2020年 | 18篇 |
2019年 | 16篇 |
2018年 | 19篇 |
2017年 | 15篇 |
2016年 | 12篇 |
2015年 | 10篇 |
2014年 | 24篇 |
2013年 | 31篇 |
2012年 | 48篇 |
2011年 | 53篇 |
2010年 | 34篇 |
2009年 | 45篇 |
2008年 | 83篇 |
2007年 | 82篇 |
2006年 | 78篇 |
2005年 | 83篇 |
2004年 | 57篇 |
2003年 | 52篇 |
2002年 | 30篇 |
2001年 | 30篇 |
2000年 | 39篇 |
1999年 | 30篇 |
1998年 | 10篇 |
1997年 | 10篇 |
1996年 | 8篇 |
1995年 | 9篇 |
1994年 | 4篇 |
1993年 | 7篇 |
1992年 | 28篇 |
1991年 | 16篇 |
1990年 | 15篇 |
1989年 | 20篇 |
1988年 | 18篇 |
1987年 | 21篇 |
1986年 | 21篇 |
1985年 | 9篇 |
1984年 | 9篇 |
1983年 | 9篇 |
1982年 | 4篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1978年 | 8篇 |
1977年 | 10篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1968年 | 4篇 |
排序方式: 共有1195条查询结果,搜索用时 15 毫秒
1.
2.
H. J. J. Kars Juha M. Hijmans Jan H. B. Geertzen Wiebren Zijlstra 《Journal of diabetes science and technology》2009,3(4):931-943
The objective of this review is to identify and review publications describing the impact of reduced somatosensation on balance. Based on knowledge of the association between specific somatosensory loss and deterioration of balance, conclusions can be made about role of somatosensation in standing balance.A systematic literature review is presented in which publications from the years 1993 through 2007 were searched in Medline and Embase. Medical Subject Headings (MESH) terms and free text words (related to balance, somatosensory loss, and lower limb) were used to perform the searches. Fifteen articles were selected for detailed review based on predetermined inclusion criteria, and three of the included articles described the effect of experimentally reduced somatosensation on balance in healthy subjects. Ten of the articles described balance in diabetic neuropathy (DN). The last two included articles described balance in Charcot-Marie-Tooth (CMT) disease type 1A (CMT1A) or type 2 (CMT2).The literature indicates that the tactile sensation is reduced in DN, CMT1A, and CMT2 and when the plantar surface of the feet was hypothermically anesthetized. Joint motion sensation seems to be impaired in patients with DN, and passive joint position sensation appears to be reduced in healthy subjects with anesthesia of ankle and foot from prolonged ischemia. This reduced somatosensation seems to have a negative effect on balance in patients with DN and CMT2; however, this appeared not to be the case in patients with CMT1A and in healthy subjects. 相似文献
3.
M Zijlstra W L Vasmel M Voormanns R E de Goede H J Schoenmakers J Nieland R M Slater C J Melief 《The Journal of experimental medicine》1986,163(5):1213-1226
To study the role of class II MHC expression in mouse lymphomagenesis, we examined the cell surface expression of I-A/E antigens on 24 spontaneous or murine leukemia virus (MuLV)-induced mouse B10.A (I-Ak, I-Ek) B cell lymphomas. Two primary B10.A B cell lymphomas were observed with strong I-Ek expression but with only minimal cell surface I-Ak expression. Both tumors are readily transplantable in syngeneic mice, with maintenance of their I-A-, I-E+ phenotype. Strikingly, one I-A-, I-E+ B cell lymphoma contains a (11; 17) translocation with a breakpoint on chromosome 17 that is localized within or very close to the H-2 complex. DNA of both tumors contains normal restriction enzyme fragments of the A alpha and A beta genes. Northern blot analyses indicated that one I-A-, I-E+ tumor strongly expressed A alpha, E alpha, and E beta mRNAs but possessed only a weak expression of A beta mRNA. The other B cell lymphoma showed A beta, E alpha, and E beta mRNA expression but only minimal A alpha mRNA expression. In 11 primary B10.A B cell lymphomas with a normal I-A+, I-E+ phenotype, no imbalances in A alpha/A beta mRNA levels were observed. The implications of these findings for the role of class II MHC expression in mouse B cell lymphoma-genesis are discussed. 相似文献
4.
5.
6.
T. C. Jansen H. N. Lafeber H. K. A. Visser G. Kwant B. Oeseburg W. G. Zijlstra 《Medical & biological engineering & computing》1978,16(3):274-277
A membrane-covered catheter-tip oxygen-electrode system is described, which gives a linear response in the Po2 range of 0–350 mm Hg. The system is highly stable, free from drift and mechanically safe for application in man. This is accomplished by using a screw cap for fastening the membrane holder, thus preventing the loss of parts and making the electrolyte chamber really fluidtight. Insulation of the platinum wire with glass precludes the possibility of fluid-bridge contact with the silver anode beyond the measuring site at the tip. 相似文献
7.
J. R. Brunsting K. R. Visser W. G. Zijlstra 《Pflügers Archiv : European journal of physiology》1975,356(3):193-208
A technique is described for perfusion of the entire coronary arterial system of the dog heart in situ and for drainage of the coronary sinus blood. Both coronary arteries are cannulated without ligation of major ventricular branches and disconnected from the aorta. The cannulas are connected to an extracorporeal system allowing perfusion under controlled pressure, without ill effects to either the heart or the blood. The arterial perfusion system is fed from the femoral arteries of the dog. The coronary sinus is cannulated for draining the blood to a venous reservoir against a controlled pressure. From the reservoir the blood is pumped into a femoral vein. Thus a preparation is obtained in which the interdependency of coronary circulation and performance of the heart has been discontinued. Under careful monitoring of pressures and flows, and of blood temperature, blood gases and plasma electrolytes, the preparation has been kept in excellent condition for up to 7 hrs. 相似文献
8.
Wiebe R. Patberg Arie Nijmeijer Jan K. Schut Adrian Versprille Jacob P. Zock Willem G. Zijlstra 《Pflügers Archiv : European journal of physiology》1992,421(2-3):280-282
In ten vagus nerves the effect of local cooling on the compound action potential was studied in the temperature range of 34 to 0 °C in spontaneously breathing, anaesthetized rabbits. The mean temperature at which the myelinated (A) fibres were completely blocked, was 10.2±2.4 °C (mean ± S.D.). In nine nerves, local vagus cooling to 0 °C failed to block all non-myelinated (C) fibres. In one nerve, total blocking occurred at 2.0 °C. We conclude that in the rabbit, the earlier found increase in tonic activity of the diaphragm following lung inflation or deflation during bilateral local vagus cooling to a temperature between 8 and 0 °C is due to afferent impulses in vagal C fibres. 相似文献
9.
A comparison was made of the contractions, induced by LTD4, histamine and phospholipase A2 in parenchymal strips of guinea pig (GPLP), porcine and human lung in a cascade superfusion system. The effects of LTD4 and phospholipase A2 on the release of TxA2 in these tissues and of TxA2, 5-HT and acetylcholine on the GPLP were also determined.In the GPLP strip, the LTC4-induced contractions are due for±80% to the release of TxA2 and for±20% to the direct effect of LTC4.The guinea pig tissue displayed the highest sentivity towards all substances, except to the contraction induced by histamine, which was most effective in the porcine tissue. Low activities wer found in the human tissue in all tests. The reason for these effects may be a difference in activities or number of cell types which participate in the reactions leading to the contractions. 相似文献
10.
C Vissinga L Nagelkerken J Zijlstra A Hertogh-Huijbregts W Boersma J Rozing 《Mechanisms of ageing and development》1990,53(2):127-139
The data presented in this paper show that the in vivo delayed-type-hypersensitivity (DTH) reaction to both H-2 and non-H-2 alloantigens declines with increasing age. It is also shown that cells generated in vitro are capable to transfer DTH to young naive syngeneic recipients. Using this in vitro system it could be demonstrated that cells from old CBA/Rij mice induced lower DTH responses than cells from young CBA/Rij mice. Depletion experiments with the effector T cell population showed that the DTH effector phase is mediated by CD4+ T cells. Lower responses in old mice were not due to increased CD8+ suppressor T cell activity, since after removal of the CD8+ T cells old CD4+ cells were still less effective in the generation of DTH effector T cells than young CD4+ cells. Addition of IL-2 containing supernatant to in vitro cultures did not improve the subsequent DTH response. From these data it can be concluded that the reduced DTH responses in old mice are not solely due to CD8+ suppressor cell activity and/or lack of IL-2, but that rather intrinsic defects of the CD4+ T cell population appear to play a major role in the impaired DTH reactivity during ageing. 相似文献