全文获取类型
收费全文 | 2740篇 |
免费 | 211篇 |
国内免费 | 41篇 |
专业分类
耳鼻咽喉 | 37篇 |
儿科学 | 34篇 |
妇产科学 | 14篇 |
基础医学 | 336篇 |
口腔科学 | 59篇 |
临床医学 | 419篇 |
内科学 | 265篇 |
皮肤病学 | 22篇 |
神经病学 | 222篇 |
特种医学 | 82篇 |
外科学 | 480篇 |
综合类 | 311篇 |
预防医学 | 68篇 |
眼科学 | 285篇 |
药学 | 216篇 |
2篇 | |
中国医学 | 126篇 |
肿瘤学 | 14篇 |
出版年
2024年 | 8篇 |
2023年 | 17篇 |
2022年 | 50篇 |
2021年 | 110篇 |
2020年 | 71篇 |
2019年 | 51篇 |
2018年 | 71篇 |
2017年 | 85篇 |
2016年 | 89篇 |
2015年 | 86篇 |
2014年 | 163篇 |
2013年 | 161篇 |
2012年 | 143篇 |
2011年 | 141篇 |
2010年 | 121篇 |
2009年 | 109篇 |
2008年 | 125篇 |
2007年 | 126篇 |
2006年 | 105篇 |
2005年 | 107篇 |
2004年 | 77篇 |
2003年 | 80篇 |
2002年 | 69篇 |
2001年 | 52篇 |
2000年 | 46篇 |
1999年 | 47篇 |
1998年 | 44篇 |
1997年 | 39篇 |
1996年 | 51篇 |
1995年 | 53篇 |
1994年 | 42篇 |
1993年 | 44篇 |
1992年 | 32篇 |
1991年 | 30篇 |
1990年 | 28篇 |
1989年 | 22篇 |
1988年 | 24篇 |
1987年 | 32篇 |
1986年 | 24篇 |
1985年 | 30篇 |
1984年 | 25篇 |
1983年 | 18篇 |
1982年 | 22篇 |
1981年 | 18篇 |
1980年 | 23篇 |
1979年 | 24篇 |
1978年 | 18篇 |
1977年 | 13篇 |
1976年 | 11篇 |
1975年 | 4篇 |
排序方式: 共有2992条查询结果,搜索用时 218 毫秒
1.
N. Sinis H. O. Rennekampff M. Haerle H. -E. Schaller 《European journal of plastic surgery》2006,28(8):507-512
Intraoperative and postoperative free flap monitoring by means of oxygen tension measurement was carried out in 11 patients. We used an invasive flexible microcatheter that allowed for measurement of oxygen tension in all types of free flaps. Two cases of the measured flaps were buried free flaps which do not allow monitoring by clinical assessment. All flaps monitored in this study survived. One case of displacement of the microcatheter occurred. In one patient, the tissue pO2 monitor successfully detected early vascular thrombosis with subsequent reoperation and salvage of the free flap. 相似文献
2.
P Schuff-Werner E Schütz W C Seyde T Eisenhauer G Janning V W Armstrong D Seidel 《European journal of clinical investigation》1989,19(1):30-37
Heparin-induced Extracorporeal LDL-Precipitation (HELP) is an effective procedure for the elimination of both plasma LDL and fibrinogen. In 10 adult patients with severe type II hyperlipoproteinemia, a single HELP treatment of 3 1 plasma led to an acute decrease in the average plasma viscosity (PV) from 1.30 to 1.1 mPas. At the same time, an even more marked decrease in the mean erythrocyte aggregation rate from a pathological value of 7.9% to a value of 3.7% (normal range less than 5%) was observed. Long-term studies on five patients demonstrated a lasting improvement in these two haemorheological variables. The acute rheological changes were also accompanied by an improvement in polarographically determined muscle oxygen tension. Mean oxygen tension values measured in both the m.biceps brachii and the m.tibialis anterior in five patients before and after a single HELP treatment increased from 30 +/- 4 to 37 +/- 7 mmHg and from 27 +/- 2 to 31 +/- 3 mmHg respectively. These results may provide an explanation for the rapid improvement in patients' clinical symptoms such as angina pectoris and in stress electrocardiogram which have been observed during HELP therapy. 相似文献
3.
Paul Wan Sia Heng Tin Wui Wong Wai See Cheong 《European journal of pharmaceutical sciences》2003,19(5):381-393
The melt agglomeration process of lactose powder with hydrogenated cottonseed oil (HCO) as the hydrophobic meltable binder was investigated by studying the physicochemical properties of molten HCO modified by sucrose stearates S170, S770 and S1570. The size, size distribution, micromeritic and adhesion properties of agglomerates as well as surface tension, contact angle, viscosity and specific volume of molten HCO, with and without sucrose stearates, were examined. The viscosity, specific volume and surface tension of molten HCO were found to be modified to varying extents by sucrose stearates which are available in different HLB values and melt properties. The growth of melt agglomerates was promoted predominantly by an increase in viscosity, an increase in specific volume or a decrease in surface tension of the molten binding liquid. The agglomerate growth propensity was higher with an increase in inter-particulate binding strength, agglomerate surface wetness and extent of agglomerate consolidation which enhanced the liquid migration from agglomerate core to periphery leading to an increased surface plasticity for coalescence. The inclusion of high concentrations of completely meltable sucrose stearate S170 greatly induced the growth of agglomerates through increased specific volume and viscosity of the molten binding liquid. On the other hand, the inclusion of incompletely meltable sucrose stearates S770 and S1570 promoted the agglomeration mainly via the reduction in surface tension of the molten binding liquid with declining agglomerate growth propensity at high sucrose stearate concentrations. In addition to being an agglomeration modifier, sucrose stearate demonstrated anti-adherent property in melt agglomeration process. The properties of molten HCO and melt agglomerates were dependent on the type and concentration of sucrose stearate added. 相似文献
4.
Robbert-Jan Roozeman Lasse Murtomäki Kyösti Kontturi 《Journal of electroanalytical chemistry (Lausanne, Switzerland)》2005,575(1):9-17
A recently introduced setup to measure the dynamic interfacial tension of expanding drops was used to compare the adsorption behaviour of a series of lipids at the electrified water∣dichloroethane interface. Phospholipids with saturated carbon chains of different length (DMPC, DPPC, DSPC, DAPC, DBPC), an unsaturated phospholipid (DOPC) and an ethanolamine (DSPE) were compared. It was found that the adsorption decreases with increasing chain length. Also, the increase of the flow rate reduces the degree of adsorption effectively. On the timescale of the experiments, the DSPE, DAPC and DBPC adsorption showed no potential dependence, whereas the adsorption of DOPC was stronger than that of the saturated lipids. Adsorption was modelled using the Langmuir adsorption isotherm; the potential dependence of adsorption is discussed. 相似文献
5.
6.
J Rothrock M Patel P Lyden C Jackson 《Cephalalgia : an international journal of headache》1996,16(1):44-49
We compared data from 243 patients with episodic migraine (EM) and 132 patients with chronic daily headache (CDH). We divided the matter group into those with tension-type headache only (CDH Type 1) and those with headaches having migrainous features (CDH Types 2+3) and compared each with the EM group and all three groups with one another. CDH Type l patients differed from those in the other groups by virtue of gender (more often male) and mean age at headache onset (older). The CDH Types 2+3 and EM groups differed only in that the former were more likely to have undergone a brain-imaging study. These data suggest that CDH Type 1 may represent a distinct headache syndrome, while CDH Types 2+3 closely resemble episodic migraine. 相似文献
7.
j. b. frøkjær † d. liao a. bergmann † b. p. mcmahon e. steffensen † a. m. drewes ‡ & h. gregersen ‡ 《Neurogastroenterology and motility》2005,17(4):531-540
A method to evaluate the three-dimensional (3-D) geometry of the human gastrointestinal wall may be valuable for understanding tissue biomechanics, mechano-sensation and function. In this paper we present a magnetic resonance imaging (MRI) based method to determine rectal geometry and validation of data obtained in three volunteers. A specially designed rectal bag was filled in a stepwise manner while MRI and bag pressure were recorded. 3-D models of curvatures, radii of curvature, tension and stress were generated and the circumferential and longitudinal strains were calculated. The computed bag volumes corresponded to the infused volumes. A pronounced bag elongation and decrease in wall thickness was observed during the bag filling. The spatial distributions of the biomechanical parameters were distinctly different between individuals and non-homogeneous throughout the rectal wall due to its complex geometry. The average tension and stress increased as a function of infused volume and circumferential strain. The present study provides a method for characterizing the complex in vivo 3-D geometry of the human rectum. The non-homogenous spatial curvature distribution suggests that simple estimates of tension based on pressure and volume do not reflect the true 3-D biomechanical properties of the rectum. 相似文献
8.
Effects of ageing on the total number of muscle fibers and motoneurons of the tibialis anterior and soleus muscles in the rat 总被引:1,自引:0,他引:1
The age-related changes in the total number of muscle fibers and motoneurons of the tibialis anterior and soleus muscles were studied using 10-, 65-, and 135-week-old rats. The number of fast twitch muscle fibers was decreased at age 65 weeks, while the numbers of slow twitch fibers and of alpha motoneurons were decreased only later, at age 135 weeks. Therefore, the degenerative process of muscle fibers differs with the fiber type. 相似文献
9.
10.
Summary In an effort to achieve a simple and less invasive method for the treatment of chronic subdural haematoma, replacement of the haematoma with oxygen by percutaneous subdural tapping was employed in 36 patients. This study was conducted on 23 haematomas in 20 patients, whose computed tomography (CT) scans immediately following the treatment were available for evaluation, with particular regard to distinguishing between their findings and those seen with tension pneumocephalus. The CT features werde divided into two patterns according to the location of oxygen; a convexity type (19 haematomas) and an interhemispheric type (4 haematomas). Analysis of the CT appearances revealed the oxygen was exclusively confined to the haematoma cavity, distinguishing it from the findings in tension pneumocephalus. This observation indicates the safety of replacement of the haematoma with oxygen when combined with our percutaneuous subdural tapping technique which prevents lesions of the inner haematoma membrane. 相似文献