全文获取类型
收费全文 | 2232篇 |
免费 | 94篇 |
国内免费 | 51篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 62篇 |
妇产科学 | 47篇 |
基础医学 | 178篇 |
口腔科学 | 23篇 |
临床医学 | 293篇 |
内科学 | 325篇 |
皮肤病学 | 44篇 |
神经病学 | 72篇 |
特种医学 | 217篇 |
外科学 | 191篇 |
综合类 | 309篇 |
预防医学 | 199篇 |
眼科学 | 31篇 |
药学 | 207篇 |
3篇 | |
中国医学 | 99篇 |
肿瘤学 | 58篇 |
出版年
2023年 | 12篇 |
2022年 | 24篇 |
2021年 | 36篇 |
2020年 | 37篇 |
2019年 | 19篇 |
2018年 | 14篇 |
2017年 | 32篇 |
2016年 | 26篇 |
2015年 | 39篇 |
2014年 | 53篇 |
2013年 | 65篇 |
2012年 | 109篇 |
2011年 | 100篇 |
2010年 | 96篇 |
2009年 | 96篇 |
2008年 | 123篇 |
2007年 | 124篇 |
2006年 | 113篇 |
2005年 | 94篇 |
2004年 | 53篇 |
2003年 | 36篇 |
2002年 | 38篇 |
2001年 | 51篇 |
2000年 | 42篇 |
1999年 | 33篇 |
1998年 | 35篇 |
1997年 | 44篇 |
1996年 | 48篇 |
1995年 | 38篇 |
1994年 | 42篇 |
1993年 | 32篇 |
1991年 | 16篇 |
1990年 | 18篇 |
1989年 | 19篇 |
1988年 | 25篇 |
1987年 | 22篇 |
1986年 | 12篇 |
1985年 | 26篇 |
1984年 | 22篇 |
1983年 | 12篇 |
1980年 | 12篇 |
1977年 | 9篇 |
1975年 | 8篇 |
1959年 | 41篇 |
1958年 | 66篇 |
1957年 | 75篇 |
1956年 | 73篇 |
1955年 | 83篇 |
1954年 | 51篇 |
1948年 | 11篇 |
排序方式: 共有2377条查询结果,搜索用时 687 毫秒
141.
MARIE-PIERRE HELLIO LE GRAVERAND YONGCHUNG OU TERESA SCHIELD-YEE LEONA BARCLAY DAVID HART TAKASHI NATSUME J. B. RATTNER 《Journal of anatomy》2000,198(5):525-535
Four major morphologically distinct classes of cells were identified within the adult rabbit meniscus using antibodies to cytoskeletal proteins. Two classes of cell were present in the fibrocartilage region of the meniscus. These meniscal cells exhibited long cellular processes that extended from the cell body. A third cell type found in the inner hyaline-like region of the meniscus had a rounded form and lacked projections. A fourth cell type with a fusiform shape and no cytoplasmic projections was found along the superficial regions of the meniscus. Using a monoclonal antibody to connexin 43, numerous gap junctions were observed in the fibrocartilage region, whereas none were seen in cells either from the hyaline-like or the superficial zones of the meniscus. The majority of the cells within the meniscus exhibited other specific features such as primary cilia and 2 centrosomes. The placement of the meniscal cell subtypes as well as their morphology and architecture support the supposition that their specific characteristics underlie the ability of the meniscus to respond to different types of environmental mechanical loads. 相似文献
142.
MOHAMED BOUTJDIR JEAN YVES LE HEUZEY THOMAS LAVERGNE SYLVAIN CHAUVAUD LOUIS GUIZE ALAIN CARPENTIER PIERRE PERONNEAU 《Pacing and clinical electrophysiology : PACE》1986,9(6):1095-1100
Spatial inhomogeneity of refractory periods, as measured during clinical electrophysiological studies, is a known predisposing factor of arrhythmia. We studied elective refractory periods (ERP) and action potential duration (ADP90 ) on isolated human atrium. Twelve samples of right atrium obtained during cardiac surgery from patients with (n = 6) and without (n = 6) atrial fibrillation (AF) were studied by microelectrode technique. For each preparation, ERP were measured at basic cycle lengths (BCL) of 1,600, 1,200, 800, and 400 msec in five different cells located around (0.8 mm) the stimulating electrode. Dispersion of ERP was significantly greater in the AF group (96.7 ± 9 versus 70.9 ± 9 msec, p = 0.01). In the non-AF group, we observed a positive linear correlation between (1) ERP and BCL (f = 0.86) (2) ADP90 and BCL (= 0.93). On the contrary, in the AF group this correlation was absent between ERP and BCL (= 0.28), poor between ADP90 and BCL (= 0.62). These results suggest that nonhomogeneous recovery of excitability (dispersion and poor adaptation) may be an important factor of arrhythmia. This inhomogeneity is present at the cellular level as well as in the entire heart. 相似文献
143.
144.
美国近距离放射治疗学会(ABS)关于
食管癌近距离放疗的应用指南 总被引:1,自引:0,他引:1
145.
In a prospective study, 121 consecutive patients with a clinical diagnosis of deep venous thrombosis of the leg were examined with real-time ultrasonography. The findings were correlated with the results of venography. The common femoral vein and the popliteal vein were evaluated for intraluminal echoes and compressibility, and the common femoral vein was also evaluated for an increase in diameter in response to the Valsalva maneuver. The superficial femoral vein and the calf veins were not evaluated. The results indicate that compressibility of the common femoral and popliteal veins is the best indication of deep venous thrombosis, with a sensitivity of 96% and a specificity of 97%. The accuracy of detection was not improved by including data from thrombus visualization or the response of the common femoral vein to the Valsalva maneuver. 相似文献
146.
147.
148.
Th. LAVERGNE L. PRUNIER L. CUIZE P. BRUNEVAL D. VON EUW J-Y. LE HEUZEY P. PERONNEAU 《Pacing and clinical electrophysiology : PACE》1989,12(1):177-186
Closed chest ablative technique that avoid barotrauma would be attractive for ablation at thin walled cardiac structures, such as the atrial free wall or coronary sinus. Transcatheter radiofrequency (RF) currents produce tissue necrosis the size of which is dependent on the contact between the tissue and the electrode. In order to assess the effects of transvenous RF ablation of atrial free wall using a suction electrode catheter, we delivered in ten dogs, one single unmodulated RF pulse 1.2 MHz, in a unipolar mode, through the distal electrode of a lumen catheter (USCI 8F) (USCI, Billerica, MA, USA) located in the right appendage. During the pulse an 80 KPa vacuum depression was applied to the lumen of the catheter. Each pulse had a 10 seconds duration and the mean delivered power was 4.3 ± 1.4 W. Aortic pressure and electrocardiogram were monitored during the procedure. A right airial electrophysiological study was performed at the ablated site, at control, after suction application and after RF pulse delivery. The animals were sacrificed after 14 or 21 days. Atrial pacing threshold values decreased after suction application in comparison to control values after the pulse (0.42 ± 0.06 vs 0.60 ± 0.23 mA, P < 0.05) but increased after the pulse delivery (2.60 ± 1.85 mA, P < 0.01). In contrast, the atrial effective refractory period did not significantly change after suction, nor after RF pulse delivery. Aortic pressure remained unchanged throughout the procedure. Complex arrhythmias were not observed during or after RF pulse delivery. One dog died suddenly at the first day after ablation, but this death was most probably unrelated to RF ablation. Anatomic lesions had a length of 8.8 ± 3.3 mm, a width of 4.6 ± 2.5 mm and a depth of 3.6 ± 1.1 mm. They were transmural in nine of the ten dogs but without atrial wall perforation in any case. Lesions suggesting tissue volatilization were present in four dogs. These results demonstrate that low energy RF currents delivered with a suction electrode catheter can produce transmural necrosis of free wall, without risk of perforation. Such ablative technique would be of interest for ablation of right sided accessory pathways or atrial ectopic foci. Further experimental data are required in order to define the optimal energy level required to avoid tissue volatilization. 相似文献
149.
Among 600 infants examined with ultrasound for vomiting, seven (mean age, 3 months) had distinctive features that can be considered diagnostic of gastric ulcer. The findings are thickening of the mucosa (greater than 4 mm) in the antropyloric region, elongation of the antropyloric canal, persistent spasm, and delayed gastric emptying. Two of the infants had slight thickening of the pyloric muscle. Gastrointestinal series or endoscopy demonstrated thickened gastric mucosa and a deformed gastric antrum in all infants, as well as actual ulceration in five. 相似文献
150.
Abstract— Great variations reported in the frequency distribution of buffer capacity values may partly be due to methodological differences in saliva sampling. In this study we wanted to see to what extent these variations are due to repetition and prestimulation. 9-yr-old schoolchildren ( n : 41, 23 girls and 18 boys), who had never had saliva samples taken before, participated in the present study. The repetition tests were carried out between 9 and 11 a.m. on three subsequent days. The effect of prestimulation was tested 4 days later with the same subjects. The buffer capacity of the samples was determined electrometrically immediately after sampling using the commercial Dentobuff-test. The intraindividual analysis revealed a significant increase in flow rate but not in buffer capacity along with repetition of the sampling. The analysis further showed that the buffer capacity of children accustomed to saliva sampling increased significantly through prestimulation of 1 min. The use of prestimulation resulted in substantial changes also in the frequency distribution of the buffer capacity values. Our results emphasize the importance of proper sampling conditions in saliva collection when screening children for high caries risk. 相似文献