全文获取类型
收费全文 | 1118篇 |
免费 | 72篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 78篇 |
妇产科学 | 11篇 |
基础医学 | 98篇 |
口腔科学 | 31篇 |
临床医学 | 105篇 |
内科学 | 274篇 |
皮肤病学 | 21篇 |
神经病学 | 24篇 |
特种医学 | 243篇 |
外科学 | 69篇 |
综合类 | 59篇 |
预防医学 | 63篇 |
眼科学 | 25篇 |
药学 | 41篇 |
中国医学 | 9篇 |
肿瘤学 | 37篇 |
出版年
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 6篇 |
2019年 | 10篇 |
2018年 | 15篇 |
2017年 | 10篇 |
2016年 | 7篇 |
2015年 | 19篇 |
2014年 | 41篇 |
2013年 | 66篇 |
2012年 | 32篇 |
2011年 | 30篇 |
2010年 | 38篇 |
2009年 | 63篇 |
2008年 | 32篇 |
2007年 | 49篇 |
2006年 | 30篇 |
2005年 | 28篇 |
2004年 | 20篇 |
2003年 | 15篇 |
2002年 | 21篇 |
2001年 | 16篇 |
2000年 | 16篇 |
1999年 | 17篇 |
1998年 | 78篇 |
1997年 | 53篇 |
1996年 | 63篇 |
1995年 | 44篇 |
1994年 | 49篇 |
1993年 | 44篇 |
1992年 | 9篇 |
1991年 | 5篇 |
1990年 | 11篇 |
1989年 | 40篇 |
1988年 | 27篇 |
1987年 | 25篇 |
1986年 | 20篇 |
1985年 | 12篇 |
1984年 | 16篇 |
1983年 | 15篇 |
1982年 | 14篇 |
1981年 | 20篇 |
1980年 | 13篇 |
1979年 | 8篇 |
1978年 | 9篇 |
1977年 | 16篇 |
1976年 | 8篇 |
1975年 | 11篇 |
1973年 | 2篇 |
1955年 | 1篇 |
排序方式: 共有1199条查询结果,搜索用时 15 毫秒
91.
通过探讨细化药品采购环节:包括建立和完善采购制度,优选药品配送企业,制定合理的采购时间、合理采购价格和合理的库存结构及库存水平。以便及时、准确地为临床用药提供安全、有效、经济的药品以及全方位保障药品供应。 相似文献
92.
93.
Shadid M Van Bel F Steendijk P Dorrepaal CA Moison R Van der Velde ET Baan J 《Basic research in cardiology》1999,94(1):23-30
The aim of this study was to determine whether allopurinol (ALLO) reduces reperfusion injury inflicted upon the heart resulting
from excess production of free oxygen radicals after hypoxia and ischemia (HI) in newborn animals. We, therefore, produced
severe HI in 13 newborn lambs by low O2-ventilation and blood volume reduction. One hour before HI seven lambs received ALLO
(20 mg/kg i.v.), six received a placebo (CONT). Cardiac function and hemodynamic parameters were assessed by sequential measurement
of left ventricular (LV) contractility through the end-systolic pressure-volume relation (ESPVR) using the conductance catheter
method. Stroke volume (SV), cardiac output (CO), and aortic pressure (Pao) were measured and ejection fraction and total peripheral resistance (TPR) were calculated before HI, upon resuscitation
(UR), and at 60 and 120 min post-HI. To estimate the effect of ALLO on redox status and anti-oxidative capacity, we measured
concentrations of uric acid, sulfhydryl (SH), malondialdehyde (MDA), ascorbic acid (AA), and dehydroxylated ascorbic acid
(DHAA) in plasma obtained from the coronary sinus and calculated the AA/DHAA ratio. Compared to CONT lambs, TPR in ALLO treated
lambs decreased significantly, accompanied by a rise in CO and SV. ALLO did not affect myocardial contractility, because the
ESPVR showed no significant differences between groups. AA/DHAA and SH showed a significant decrease in ALLO animals vs pre-HI,
but not in CONT animals. Uric acid was significantly decreased in ALLO as compared to pre-HI and CONT animals. MDA was significantly
increased in CONT animals at 15 min post-HI as compared to pre-HI, whereas in ALLO animals MDA showed a significant increase
at 120 min post-HI vs CONT. We conclude that pretreatment with ALLO has a beneficial effect on the pump function by afterload
reduction but not by changes in contractility. Furthermore, ALLO inhibited uric acid formation with a consequent decrease
in anti-oxidative capacity.
Received: 15 December 1997, Returned for 1. revision: 8 January 1998, 1. Revision received: 4 March 1998, Returned for 2.
revision: 25 March 1998, 2. Revision received: 15 June 1998, Returned for 3. revision: 2 July 1998, Accepted: 6 August 1998 相似文献
94.
Hasegawa BH; Naimuddin S; Dobbins JT d; Mistretta CA; Peppler WW; Hangiandreou NJ; Cusma JT; McDermott JC; Kudva BV; Melbye KM 《Radiology》1986,159(2):537-543
The feasibility of producing patient-specific beam attenuators for chest radiography has been investigated using an anthropomorphic phantom and a human volunteer. A low-dose test exposure is digitized, processed, and used to print a small cerium filter, which is placed in the x-ray beam near the collimator. The final radiograph is recorded on film. The technique results in relatively uniform film exposure, so that structures in all regions of the chest are simultaneously displayed with optimal film contrast. The equalized exposure improves image quality in the normally underpenetrated regions and reduces the role of cross-scatter from the lungs. The image is analogous to optical or computer-processed unsharp masking techniques, but the processing is accomplished in the x-ray beam and results in an improved exposure distribution, giving advantages that cannot be achieved with image processing techniques alone. 相似文献
95.
96.
A normal variant, the foraminal spur, is described in five patients. It was seen on computed tomographic studies as a bony process extending from either the pars or the pedicle into the neuroforamen dorsal to the nerve root. In four of the cases it was seen bilaterally. None of the patients had any symptoms related to these spurs. No associated disease of the neuroforamen or facet was present. These spurs most likely represent ossification of the ligamentum flavum at its point of insertion and should not be mistaken for osteophytes, free disk fragments that have calcified, or fracture fragments. Sagittal reformations are helpful in visualizing the extent of the foraminal spurs. 相似文献
97.
98.
目的探讨腹部急性出血选择性血管造影诊断及介入治疗价值。方法回顾性分析80例行选择性动脉血管造影及血管内介入治疗的腹部及盆腔急性出血患者的临床资料。结果80例均采用Seldinger技术,经股动脉插管后作选择性血管造影,用碘化油、明胶海绵或弹簧圈栓塞治疗,80例中完全止血68例、再出血9例、无效3例。结论介入方法不仅可确定出血部位,而且可达到止血目的,效果确切。 相似文献
99.
100.
Gerard de Vries Rob AH van Hest Conny CA Burdo Dick van Soolingen Jan H Richardus 《BMC infectious diseases》2009,9(1):151