全文获取类型
收费全文 | 173篇 |
免费 | 8篇 |
国内免费 | 3篇 |
专业分类
妇产科学 | 2篇 |
基础医学 | 53篇 |
临床医学 | 3篇 |
内科学 | 58篇 |
皮肤病学 | 2篇 |
神经病学 | 13篇 |
特种医学 | 2篇 |
外科学 | 5篇 |
综合类 | 11篇 |
预防医学 | 3篇 |
眼科学 | 9篇 |
药学 | 20篇 |
中国医学 | 3篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 4篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 7篇 |
2015年 | 2篇 |
2014年 | 6篇 |
2013年 | 9篇 |
2012年 | 5篇 |
2011年 | 3篇 |
2010年 | 5篇 |
2009年 | 9篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 10篇 |
2005年 | 6篇 |
2004年 | 7篇 |
2003年 | 9篇 |
2002年 | 8篇 |
2001年 | 6篇 |
2000年 | 6篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 4篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1978年 | 2篇 |
1976年 | 2篇 |
排序方式: 共有184条查询结果,搜索用时 15 毫秒
1.
应用微血管铸型扫描电镜技术研究8例成人肾脏的肾小球微血管构筑,结果发现:1.输入小动脉在肾小球血管极处分为2~5支小球内小叶微动脉。输入小动脉血管铸型的直径为126.35±20.5μm。2.肾小球是由小球内小叶微动脉、毛细血管、毛细血管网小叶间交通支和毛细血管输出根所构成的近似于球状体,小球内每个毛细血管网小叶均是一个独立的机能解剖学单位;3.299个肾小球均有一支输出小动脉,只有一个肾小球有两支输出小动脉。输出小动脉的血管铸型直径为91.35±11.7μm。4.输出小动脉起始处具有毛细血管前括约肌装置,此结构在调控肾小球内的微循环血流有着重要意义。 相似文献
2.
M. MASPERS J. BJ
RNBERG P.-O. GRNDE S. MELLANDER 《Acta physiologica (Oxford, England)》1990,138(4):509-521
The sympathetic nervous control of the vascular bed of cat gastrocnemius muscle was studied with a new whole-organ technique which permits simultaneous, continuous and quantitative measurements of capillary pressure (Pc), capillary fluid exchange and resistance reactions in the whole vascular bed and in its three consecutive sections: large-bore arterial vessels (> 25 μm), arterioles (< 25 μm) and veins. The results demonstrated a distinct neural control of all three consecutive vascular sections, graded in relation to the rate of nerve excitation up to maximum at 16 Hz. Stimulation at high rates, which in the steady state caused an average rise of overall regional resistance from 15.3 to 120 PRU (7.8-fold increase), thus raised large-bore arterial vessel resistance from 8.8 to 64 PRU (7.3-fold increase), arteriolar resistance from 4.5 to 49 PRU (10.9-fold increase) and venous resistance from 2.0 to 7 PRU (3.5-fold increase). The rate of resistance development (PRU s-1) of the sympathetic constrictor response was much higher in the arteriolar than in the other sections, which indicates that the neural control is especially prompt and efficient in the arterioles. A passive component was shown to contribute to the described responses only on the venous side, but in no case by more than 10% of the total sympathetic venous resistance response, which thus is mainly active. Of special functional importance was that the new technique provided information about the adrenergic control of Pc, in absolute figures. From the control value of 19 mmHg, graded sympathetic stimulation caused a graded decline in Pc, at maximum constriction by about 7 mmHg. This resulted in marked net transcapillary fluid absorption, in turn increasing plasma volume. 相似文献
3.
压力超负荷大鼠心、肺、肾血管重构的动态研究 总被引:3,自引:1,他引:3
目的 探讨压力超负荷与大鼠心、肺、肾内小动脉形态学重建的关系。方法 采用缩窄腹主动脉造成大鼠压力负荷模型,将大鼠随机分为两组:假手术组(SOG)和手术组(OG)。每组分为术后1、2、4、7、14、21、30、45、60d 9个时间点,对大鼠心、肺、肾组织连续切片,采用光镜配合计算机图像分析技术检测三个脏器小动脉几何形态的动态改变。结果 (1)随着压力负荷的增加,心、肺、肾小动脉的形态学重建可能存在时间顺序。(2)平均动脉压和造模时间与小冠状动脉和肾小动脉的壁腔比显著相关,而对小冠状动脉的管壁面积无影响;收缩压和造模时间与肾小动脉的管壁面积显著相关;造模时间与肺小动脉的壁腔比和管壁面积显著相关。结论 压力超负荷与心、肺、肾小血管的动态重构关系密切。小冠状动脉的重建以中膜平滑肌细胞的重排为主,肺、肾内小动脉的重建则可能存在中膜平滑肌细胞的肥大和增殖。 相似文献
4.
5.
Radhakrishnan Muthuchellappan Ramesh V. J. Umamaheswara Rao Ganne S. Thennarasu K. Anjana Jacob Sripathy G. 《Journal of medical engineering & technology》2018,42(1):18-25
Blood pressure (BP), a surrogate of cardiac output (CO), is also dependent on systemic vascular resistance (SVR). But SVR is not routinely monitored in daily clinical practice. We hypothesise that the time difference between the peripheral arterial waveform and the finger plethysmographic waveform (time lag index - TLi) could indicate the systemic vascular resistance. In this study, we correlated TLi with the systemic vascular resistance measured by minimally invasive CO monitor (pulse contour analysis). SVR changes in response to administration of mannitol were studied. American Society of Anesthesiologists (ASA) class I and II patients undergoing major intracranial surgeries were recruited. Arterial cannulation and pulse-oximetry recordings were done in the same limb. Arterial and plethysmographic waveforms were recorded before mannitol infusion (baseline) and at every 10 minutes for 60 minutes after the termination of mannitol infusion. Simultaneously, SVR was recorded from the Vigileo FLotrac CO monitor. Using custom-made programme, the time difference between both waveforms was calculated and corrected for heart rate (TLi). The correlation between time lag and the systemic vascular resistance was assessed using a mixed effect model, adjusting for the subject. Data of one hundred subjects were analysed. Following mannitol administration, there was a significant decrease in the SVR and the TLi (p?.001). The patient characteristics influenced both the baseline values of SVR (intercept) and the changes in SVR over time (slope). As both the baseline value and the change over time for SVR were different in each patient, we used mixed effect model analysis to assess the relationship between SVR and TLi for different time periods. The effect of TLi on SVR was significant (β?=?877.16, p?=?.008). The high beta coefficient suggests that when SVR increases, the TLi also increase and vice versa. A strong correlation between SVR and TLi was demonstrated for a given patient. Further studies are needed to explore the possibility of utilising this parameter to follow up changes in SVR in an individual patient at a particular point in time in different clinical scenarios. 相似文献
6.
7.
8.
背景:随着骨组织工程研究的不断深入和对骨代谢过程的不断认识,分析组织工程骨的血液供应和营养状况已成为目前的研究重点。目的:比较和评价常用的微小血管检测方法,明确各种方法的利弊,为研究组织工程骨内微血管的分布和计数提供借鉴意义。方法:分别用3种常用的血管评价法对SD大鼠膝关节周围微小动脉网进行分析对比,18只SD大鼠均分为免疫组化组、血管造影组、CT扫描重建组。结果与结论:免疫组化技术能观察到血管的分布范围,但是无法评价血管空间分布的整体情况。血管造影技术和CT检查则可以提供形象的血管空间分布图,但是CT检测时部分微小血管显示不清。免疫组化检出(26.50±3.02)条血管数明显多于血管造影(14.12±1.47)条和CT检测(9.00±1.79)条,其中CT检测组可检出的血管数最少。说明免疫组化和血管造影可以为微小血管提供微观和宏观的评价方法,从两个层面一起观察,更好的分析血管的情况,对微血管的评价有很好的借鉴意义。 相似文献
9.
Signaling pathways of mechanotransduction in arteriolar endothelium and smooth muscle cells in hypertension 总被引:2,自引:0,他引:2
Koller A 《Microcirculation (New York, N.Y. : 1994)》2002,9(4):277-294
Hypertension, a disease with a high incidence in the population, affects all parts of the cardiovascular system. Studying the alteration of vasomotor responses of microvessels of hypertensive animals or responses of vessels following short-term increases in hemodynamic forces helps us to better understand the underlying cellular signaling events responsible for their functional adaptation. These adaptations are likely to precede the structural remodeling of arterioles, resulting in irreversible increases in peripheral vascular resistance in hypertension. Although malfunction of several mechanisms can lead to the development of hypertension, hemodynamic forces (such as pressure and shear stress) are increased in all forms of hypertension. Thus, local mechanisms that sense the level of these forces and transduce the signals into vasomotor responses must be affected in all forms of hypertension. The endothelium has a central role in the early functional adaptations. Pressure-induced myogenic constriction is enhanced due to the augmented release of endothelium-derived constrictor factors that modulate arteriolar smooth muscle sensitivity to Ca(2+). In contrast, flow/shear stress-induced dilation of arterioles is reduced in hypertension, due to the impaired mediation of the response by nitric oxide (NO). The magnitude of impairment is gender specific, primarily due to an estrogen-dependent enhancement of NO release in females. It is proposed that the elevated hemodynamic forces present in hypertension may themselves initiate these alterations, probably by enhancing the release of reactive oxygen species (ROS; produced by xanthine oxidase, NAD(P)H oxidoreductase, eNOS, etc.), which then interfere with the synthesis and/or action of endothelium-derived mediators. Interfering early on with these mechanisms may prevent the development of irreversible structural changes of the microcirculation observed in hypertension. 相似文献
10.
Prostaglandin E1 was injected close to retinal arterioles by iontophoresis. Vasodilatation apparently similar to that caused by hypercapnia or hypoxia was observed. Inhibitors of prostaglandin synthetase were injected into the circulation. There was a reversible inhibition of the retinal vasodilation normally induced by hypercapnia. It is concluded that prostaglandin E1 satisfies two criteria for a candidate for a mediator of hypercapnia-induced arteriolar dilatation. The effect of hypoxia appears more complicated. 相似文献