全文获取类型
收费全文 | 4035篇 |
免费 | 209篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 87篇 |
儿科学 | 113篇 |
妇产科学 | 38篇 |
基础医学 | 553篇 |
口腔科学 | 223篇 |
临床医学 | 346篇 |
内科学 | 680篇 |
皮肤病学 | 76篇 |
神经病学 | 396篇 |
特种医学 | 170篇 |
外科学 | 598篇 |
综合类 | 10篇 |
一般理论 | 1篇 |
预防医学 | 326篇 |
眼科学 | 123篇 |
药学 | 240篇 |
中国医学 | 4篇 |
肿瘤学 | 273篇 |
出版年
2024年 | 4篇 |
2023年 | 34篇 |
2022年 | 55篇 |
2021年 | 105篇 |
2020年 | 78篇 |
2019年 | 91篇 |
2018年 | 111篇 |
2017年 | 61篇 |
2016年 | 123篇 |
2015年 | 105篇 |
2014年 | 139篇 |
2013年 | 206篇 |
2012年 | 274篇 |
2011年 | 262篇 |
2010年 | 160篇 |
2009年 | 145篇 |
2008年 | 300篇 |
2007年 | 275篇 |
2006年 | 304篇 |
2005年 | 252篇 |
2004年 | 227篇 |
2003年 | 231篇 |
2002年 | 211篇 |
2001年 | 32篇 |
2000年 | 21篇 |
1999年 | 33篇 |
1998年 | 52篇 |
1997年 | 32篇 |
1996年 | 30篇 |
1995年 | 30篇 |
1994年 | 32篇 |
1993年 | 35篇 |
1992年 | 20篇 |
1991年 | 13篇 |
1990年 | 10篇 |
1989年 | 13篇 |
1988年 | 15篇 |
1987年 | 9篇 |
1986年 | 9篇 |
1985年 | 13篇 |
1984年 | 13篇 |
1983年 | 14篇 |
1982年 | 10篇 |
1981年 | 10篇 |
1980年 | 8篇 |
1979年 | 12篇 |
1978年 | 12篇 |
1977年 | 4篇 |
1975年 | 4篇 |
1974年 | 4篇 |
排序方式: 共有4257条查询结果,搜索用时 15 毫秒
81.
82.
The postheparin plasma lipoprotein lipase (LPL) activity and plasma HDL and LDL cholesterol concentrations, decreases significantly during probucol treatment of the rat. The reduction of the LPL activity obviously took place in adipose tissue. The activity of hepatic lipase and the in vitro synthesis of cholesterol in the liver or isolated jejunal villous cells were unaffected by the probucol treatment. Plasma triglyceride and VLDL cholesterol concentrations remained similar in the control and probucol groups despite the difference in the LPL activity, whereas the esterified VLDL cholesterol level was significantly reduced in the probucol group. The results suggest that the HDL lowering action of probucol is contributed by the reduced LPL activity probably via impaired VLDL metabolism. 相似文献
83.
84.
Effects of chitosan and bioactive glass modifications of knitted and rolled polylactide‐based 96/4 L/D scaffolds on chondrogenic differentiation of adipose stem cells
下载免费PDF全文
![点击此处可从《Journal of tissue engineering and regenerative medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Katja Ahtiainen Laura Sippola Manu Nurminen Bettina Mannerström Suvi Haimi Riitta Suuronen Jari Hyttinen Timo Ylikomi Minna Kellomäki Susanna Miettinen 《Journal of tissue engineering and regenerative medicine》2015,9(1):55-65
The performance of biodegradable knitted and rolled 3‐dimensional (3D) polylactide‐based 96/4 scaffolds modified with bioactive glass (BaG) 13‐93, chitosan and both was compared with regard to the viability, proliferation and chondrogenic differentiation of rabbit adipose stem cells (ASCs). Scaffold porosities were determined by micro‐computed tomography (μCT). Water absorption and degradation of scaffolds were studied during 28‐day hydrolysis in Tris‐buffer. Viability, number and differentiation of ASCs in PLA96/4 scaffolds were examined in vitro. The dimensions of the scaffolds were maintained during hydrolysis and mass loss was detected only in the BaG13‐93 containing scaffolds. ASCs adhered and proliferated on each scaffold type. Cell aggregation and expression of chondral matrix components improved in all scaffold types in chondrogenic medium. Signs of hypertrophy were detected in the modified scaffolds but not in the plain PLA96/4 scaffold. Chondrogenic differentiation was most enhanced in the presence of chitosan. These findings indicate that the plain P scaffold provided a good 3D‐matrix for ASC proliferation whereas the addition of chitosan to the PLA96/4 scaffold induced chondrogenic differentiation independent of the medium. Accordingly, a PLA96/4 scaffold modified by chitosan could provide a functional and bioactive basis for tissue‐engineered chondral implants. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
85.
Adverse Events in Mobility‐Limited and Chronically Ill Elderly Adults Participating in an Exercise Intervention Study Supported by General Practitioner Practices
下载免费PDF全文
![点击此处可从《Journal of the American Geriatrics Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
86.
Timo Jaakkola C. K. John Wang Markus Soini Jarmo Liukkonen 《Journal of Sports Science and Medicine》2015,14(3):477-483
The purpose of this study was to identify student clusters with homogenous profiles in perceptions of task- and ego-involving, autonomy, and social relatedness supporting motivational climate in school physical education. Additionally, we investigated whether different motivational climate groups differed in their enjoyment in PE. Participants of the study were 2 594 girls and 1 803 boys, aged 14-15 years. Students responded to questionnaires assessing their perception of motivational climate and enjoyment in physical education. Latent profile analyses produced a five-cluster solution labeled 1) ‘low autonomy, relatedness, task, and moderate ego climate’ group’, 2) ‘low autonomy, relatedness, and high task and ego climate, 3) ‘moderate autonomy, relatedness, task and ego climate’ group 4) ‘high autonomy, relatedness, task, and moderate ego climate’ group, and 5) ‘high relatedness and task but moderate autonomy and ego climate’ group. Analyses of variance showed that students in clusters 4 and 5 perceived the highest level of enjoyment whereas students in cluster 1 experienced the lowest level of enjoyment. The results showed that the students’ perceptions of various motivational climates created differential levels of enjoyment in PE classes.
Key points
- Latent profile analyses produced a five-cluster solution labeled 1) ‘low autonomy, relatedness, task, and moderate ego climate’ group’, 2) ‘low autonomy, relatedness, and high task and ego climate, 3) ‘moderate autonomy, relatedness, task and ego climate’ group 4) ‘high autonomy, relatedness, task, and moderate ego climate’ group, and 5) ‘high relatedness and task but moderate autonomy and ego climate’ group.
- Analyses of variance showed that clusters 4 and 5 perceived the highest level of enjoyment whereas cluster 1 experienced the lowest level of enjoyment. The results showed that the students’ perceptions of motivational climate create differential levels of enjoyment in PE classes.
87.
Sorbitol malabsorption in normal volunteers and in patients with coeliac disease. 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Gut》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Sorbitol is a hexahydroxy alcohol used as a sugar substitute in many dietetic foods and as a drug vehicle. Previous studies have suggested that sorbitol ingestion may be an additional cause of non-specific gastrointestinal distress. We evaluated sorbitol malabsorption in 30 healthy volunteers, seven patients with untreated coeliac disease and nine patients with coeliac disease on a gluten free diet, using a four hour H2 breath test. After ingestion of test solutions containing sorbitol 10 and 20 g and of four sweets (6.8 g sorbitol), 90%, 100%, and 62% of healthy volunteers, respectively had significantly raised H2 excretion, indicating malabsorption of sorbitol. Of all healthy subjects tested, 45% after 10 g, 100% after 20 g, and 50% after four sweets complained of symptoms of carbohydrate intolerance during the eight hours after sorbitol. After a 5 g dose given at concentrations of 2%, 4%, 8%, 16%, malabsorption was shown in 10%, 12%, 22%, and 43% of the healthy volunteers. Symptoms of intolerance at 5 g were experienced only at concentrations of 8% and 16%. Unlike healthy volunteers and coeliac patients on a gluten free diet, 100% of untreated coeliacs malabsorbed a 2% solution of 5 g sorbitol. These results show that malabsorption and intolerance of sorbitol may result from ingestion of doses and/or concentrations usually found in many foods and drugs; they underline the need to consider this as a possible and hitherto underestimated cause of gastrointestinal symptoms. 相似文献
88.
89.
Maria Malm Kirsi Tamminen Suvi Lappalainen Hanni Uusi-Kerttula Timo Vesikari Vesna Blazevic 《Clinical and Vaccine Immunology : CVI》2015,22(6):656-663
Norovirus (NoV) genogroup I (GI) and GII are responsible for most human infections with NoV. Because of the high genetic variability of NoV, natural infection does not induce sufficient protective immunity to different genotypes or to variants of the same genotype and there is little or no cross-protection against different genogroups. NoV-derived virus-like particles (VLPs) are promising vaccine candidates that induce high levels of NoV-specific humoral and cellular immune responses. It is believed that a bivalent NoV vaccine consisting of a representative VLP from GI and GII is a minimum requirement for an effective vaccine. Here, we compared the abilities of monovalent immunizations with NoV GI.1-2001, GI.3-2002, GII.4-1999, and GII.4-2010 New Orleans VLPs to induce NoV type-specific and cross-reactive immune responses and protective blocking antibody responses in BALB/c mice. All of the VLPs induced comparable levels of type-specific serum IgG antibodies, as well as blocking antibodies to the VLPs used for immunization. However, the abilities of different VLP genotypes to induce cross-reactive IgG and cross-blocking antibodies varied remarkably. Our results confirm previous findings of a lack of cross-protective immune responses between GI and GII NoVs. These data support the rationale for including NoV GI.3 and GII.4-1999 VLPs in the bivalent vaccine formulation, which could be sufficient to induce protective immune responses across NoV genotypes in the two common genogroups in humans. 相似文献
90.