全文获取类型
收费全文 | 237篇 |
免费 | 11篇 |
国内免费 | 52篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 10篇 |
基础医学 | 18篇 |
口腔科学 | 6篇 |
临床医学 | 56篇 |
内科学 | 57篇 |
皮肤病学 | 4篇 |
神经病学 | 1篇 |
特种医学 | 67篇 |
外科学 | 23篇 |
综合类 | 9篇 |
预防医学 | 9篇 |
药学 | 27篇 |
肿瘤学 | 12篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 5篇 |
2013年 | 8篇 |
2012年 | 2篇 |
2011年 | 4篇 |
2010年 | 10篇 |
2009年 | 9篇 |
2008年 | 4篇 |
2007年 | 44篇 |
2006年 | 8篇 |
2005年 | 13篇 |
2004年 | 1篇 |
2002年 | 3篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 18篇 |
1997年 | 11篇 |
1996年 | 20篇 |
1995年 | 13篇 |
1994年 | 19篇 |
1993年 | 10篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 8篇 |
1985年 | 6篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1962年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有300条查询结果,搜索用时 15 毫秒
91.
目的:探索构建组织工程化仿生骨种植体的方法流程,并制备成骨细胞-可吸收载体种植体样品,同时尝试建立组织工程化非承载骨种植体的评价方法。方法:实验于2001-05/2005-12分别在天津市口腔医院组织工程实验室和天津大学材料学院高分子材料研究所完成。①通过相分离技术制备壳聚糖/明胶三维网络多孔支架,在支架材料表面原位沉积纳米级的羟基磷灰石晶体,构筑纳米羟基磷灰石/壳聚糖/明胶仿生骨组织工程支架材料,并进行表征和性能检测。②用酶消化法和条件培养法分离、诱导培养中国小型猪成骨细胞作为组织工程种子细胞。③用静态复合共培养法体外构建2种骨组织工程种植体样品:成骨细胞-纳米羟基磷灰石/壳聚糖/明胶仿生骨种植体,成骨细胞-纳米羟基磷灰石/胶原种植体。④采用扫描电镜、透射电镜、FDA荧光、LDH、MTT等定期观测仿生骨样品中细胞形态、细胞增殖速率、碱性磷酸酶活性、矿化结节形成等指标,以比较样品的细胞增殖活性和成骨活性。结果:①成功构筑了具有良好的生物相容性和力学相容性的纳米羟基磷灰石/壳聚糖/明胶,这种材料具有适于细胞黏附与生长的(90±1)%的孔隙率,孔径为100 ̄300μm的微孔结构,且原位沉积的纳米羟基磷灰石晶体的粒径为50nm左右,接近与天然骨的组成。②自中国小型猪腿骨成功分离培养了成骨细胞,并在诱导培养条件下,表现出很强的增殖活力和成骨活性,适合作为实验用骨组织工程的种子细胞。③成功构建了两种成骨细胞-可吸收载体种植体样品:经检验仿生构建的小型猪成骨细胞-纳米羟基磷灰石/壳聚糖/明胶种植体具有细胞亲和性和体外成骨活性。结论:①在体外成功仿生构建了结构与活性接近天然骨的骨组织工程种植体--纳米羟基磷灰石/壳聚糖/明胶种植体。②初步建立了仿生组织工程化非承载骨种植体的评价方法,为其进一步用于体内修复颅颌骨组织损伤的深化研究提供了实验数据和科学依据。 相似文献
92.
B Kristrom J Karlberg K Albertsson-Wikland and the Swedish Paediatric Study Group for GH treatment 《Acta paediatrica (Oslo, Norway : 1992)》1995,84(1):51-57
The aim of this study was to identify predictors of the growth response to growth hormone (GH) during the first 2 years of GH treatment, using auxological data and the maximum GH response (GHmax ) to provocation tests. The patients were 169 prepubertal short children (27F, 142M), with Gmax values ranging from 0 to 65 mU/1. Their mean age (± SD)was8.3 ± 2.4 years (range 3-13 years), mean height SDS –3.0 ± 0.7 (range –1.5 to –6.0SDS) and mean pretreatment height velocity was normal (± 0.0 SDS) (range -1.6 to + 0.9 SDS). The increase in height SDS during the first 2 years of GH treatment (0.1 U/kg/day) varied from 0.10 to 3.75 SDS, with younger children having a better growth response. Individual growth responses correlated (p < 0.001) with GHmax (r =–0.37), age (r= -0.35), 1-year pretreatment delta SDS (r = -0.25), mid-parental height SDS (r = 0.34), height SDS at start of treatment (r =–0.22) and difference between height SDS of an individual child at the onset of GH treatment and mid-parental height expressed in SDS (diff SDS) (r = –0.43). In a multiple stepwise linear regression model, diff SDS and log GHmax were found to be the strongest predictors of the magnitude of the growth response. In the short children in this study who exhibited a broad range of GHmax values, 33% of the growth response during the first 2 years of treatment could be predicted. 相似文献
93.
Retention of glycoprotein Ib/IX receptors on external surfaces of thrombin-activated platelets in suspension 总被引:3,自引:0,他引:3
The present study has evaluated the hypothesis stating that glycoprotein (GP) Ib/IX, the receptor for von Willebrand factor (vWF), is downregulated and cleared from exposed surfaces to channels of the open canalicular system (OCS) on platelets activated by thrombin in suspension. Cryosections of resting and thrombin-activated platelets fixed at intervals of 1 to 30 minutes after stimulation by thrombin and stained with antiglycocalicin antibody and protein A gold showed no decrease in the density of GPIb/IX receptors on the platelet surface or increase on linings of the OCS at any interval after stimulation by thrombin. Thin sections of platelets exposed to thrombin in suspension followed by settling onto a plastic chamber for intervals of 1 to 30 minutes revealed retention of GPIb/IX receptors on exposed surfaces detected by vWF, anti-vWF, and protein A gold throughout the 30-minute period of study. Results of this investigation indicate that GPIb/IX receptors remain on the surface of platelets activated by thrombin in suspension, are not cleared to the OCS, and retain the ability to bind vWF for at least 30 minutes. 相似文献
94.
95.
96.
HELEN HØGH PETERSEN XU CHEN ADRIAN PIETERSEN JESPER HASTRUP SVENDSEN STIG HAUNSØ 《Pacing and clinical electrophysiology : PACE》1998,21(1):322-326
This study was designed to investigate the effect of the convective cooling of the tip of the ablation electrode during temperature controlled radiofrequency ablation. In vivo two different application sites in the left ventricle of anaesthetised pigs were ablated and in vitro ablation was performed during two different flow-velocities in a tissue bath, while electrode contact pressure and position were unchanged. Target temperature was 80 °C. Obtained tip temperature, power consumption and lesion dimensions were measured. In vivo lesion volume, depth and width were found significantly larger for septal applications than apical applications (p<0.01) and more power was used (p<0.001). Obtained tip temperature was significantly lower in the septal applications (p<0.001). In vitro increased convective cooling by induction of flow yielded larger lesion volume, depth and width (p<0.01), and had higher power consumptions (p<0.01). Obtained tip temperature did not differ significantly. For the given chosen target temperature power consumption was positively related to lesion volume (r= 0.66 in vivo and 0.65 in vitro), whereas obtained tip temperature was not (r = - 0.49 in vivo and - 0.61 in vitro). We conclude that during temperature controlled radiofrequency ablation lesion size differs for septal and apical left ventricular applications. Differences in convective cooling might play an important role in this respect. This is supported by our in vitro experiments, where increased convective cooling by induction of a flow around the electrode tip increases lesion dimensions and power consumptions. Furthermore we conclude that for the given target temperature the power consumption is positively correlated with lesion volume (p<0.001), whereas the obtained tip temperature is not. 相似文献
97.
98.
Hemodynamic significance of the paraumbilical vein in portal hypertension: assessment with duplex US 总被引:3,自引:0,他引:3
Mostbeck GH; Wittich GR; Herold C; Vergesslich KA; Walter RM; Frotz S; Sommer G 《Radiology》1989,170(2):339-342
Hemodynamic evaluation of portal and umbilical venous flow with duplex ultrasound (US) was performed in 11 patients with cirrhosis of the liver and a large umbilical vein. Two of these patients had hepatofugal flow in the umbilical vein exceeding hepatopetal flow in the portal vein. These two patients had no evidence of esophageal varices and bleeding. The remaining nine patients had esophageal varices. In these patients, the hepatopetal flow in the portal vein exceeded the hepatofugal flow through the umbilical vein. The authors conclude that duplex US may help identify the massive hepatofugal flow through a large umbilical vein that may reduce the likelihood of esophageal varices and variceal bleeding. 相似文献
99.
Diagnostic laparoscopy by physicians: we should do it 总被引:1,自引:0,他引:1
Only a few centres in the UK practise diagnostic laparoscopy and liver
biopsy; in comparison, laparoscopy is widely practised by physicians in
Europe, the Far East and in the US. We consider the role of diagnostic
laparoscopy in the assessment of liver disease in the 1990s, and describe
the technique of laparoscopy, including how it may be performed safely in
the endoscopy suite, under local anesthesia with mild sedation and
analgesia, enabling direct visualization of the liver. We examine potential
complications and contraindications. Complication rate and mortality are
similar to that for percutaneous liver biopsy. Finally, the invaluable role
of laparoscopy in diagnosing and staging chronic hepatitis, cirrhosis,
liver tumours, hepatic infiltration, infection and structural abnormalities
is considered.
相似文献
100.