全文获取类型
收费全文 | 1559篇 |
免费 | 103篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 79篇 |
妇产科学 | 56篇 |
基础医学 | 265篇 |
口腔科学 | 159篇 |
临床医学 | 123篇 |
内科学 | 341篇 |
皮肤病学 | 27篇 |
神经病学 | 65篇 |
特种医学 | 159篇 |
外国民族医学 | 2篇 |
外科学 | 109篇 |
综合类 | 57篇 |
预防医学 | 80篇 |
眼科学 | 8篇 |
药学 | 55篇 |
中国医学 | 4篇 |
肿瘤学 | 80篇 |
出版年
2023年 | 6篇 |
2022年 | 7篇 |
2021年 | 35篇 |
2020年 | 16篇 |
2019年 | 28篇 |
2018年 | 32篇 |
2017年 | 31篇 |
2016年 | 31篇 |
2015年 | 26篇 |
2014年 | 42篇 |
2013年 | 66篇 |
2012年 | 76篇 |
2011年 | 60篇 |
2010年 | 73篇 |
2009年 | 67篇 |
2008年 | 56篇 |
2007年 | 81篇 |
2006年 | 55篇 |
2005年 | 46篇 |
2004年 | 47篇 |
2003年 | 39篇 |
2002年 | 36篇 |
2001年 | 48篇 |
2000年 | 35篇 |
1999年 | 41篇 |
1998年 | 46篇 |
1997年 | 39篇 |
1996年 | 43篇 |
1995年 | 41篇 |
1994年 | 34篇 |
1993年 | 26篇 |
1992年 | 26篇 |
1991年 | 24篇 |
1990年 | 22篇 |
1989年 | 28篇 |
1988年 | 26篇 |
1987年 | 20篇 |
1986年 | 22篇 |
1985年 | 21篇 |
1984年 | 16篇 |
1983年 | 20篇 |
1982年 | 19篇 |
1981年 | 19篇 |
1980年 | 20篇 |
1979年 | 8篇 |
1978年 | 18篇 |
1977年 | 9篇 |
1976年 | 8篇 |
1975年 | 13篇 |
1969年 | 3篇 |
排序方式: 共有1670条查询结果,搜索用时 0 毫秒
41.
背景目前已开展了对重性精神病患者进提供连续性服务的研究。目的探讨基层对有抑郁症风险患者提供连续性服务的水平,并与对心力衰竭患者的服务水平进行对比。方法采用抑郁症风险患者与心力衰竭患者对比的探索性研究。采用患者问卷评估服务的持续性,包含如下内容:(1)联系的服务提供者数(个人连续性);(2)诊所内服务提供者之间的合作(团队连续性)(6个项目,分数1~5分);(3)诊所外全科医师与服务提供者之间的合作(跨界连续性)(4个项目,分数1~5分)。结果大多数抑郁症风险患者在过去1年中寻遍整个服务提供界联系了几个服务提供者,曾遇到过高水平团队连续性服务及低水平跨界连续性服务。在诊所中可接触到的不同服务提供者要明显多于心力衰竭患者服务提供者(P<0.01)。抑郁症风险患者的服务提供者之间的合作更好一些,每项平均得分4.3分,心力衰竭患者得分为4.0分(P=0.03)。然而,跨界连续性服务方面正好相反:抑郁症风险患者每项平均得分3.5分,心力衰竭患者得分为4.0分(P=0.01)。结论抑郁症风险患者与心力衰竭患者之间的探索性对比显示:体验服务连续性方面的差距不大。对此还应行进一步分析。 相似文献
42.
The “hidden” concealed left‐sided accessory pathway: An uncommon cause of SVT in young people 下载免费PDF全文
43.
Gunnbjörnsdottir MI Norbäck D Plaschke P Norrman E Björnsson E Janson C 《Respiratory medicine》2003,97(4):302-307
Several epidemiological studies have indicated that building dampness affects the respiratory health of the inhabitants. In this study we investigated the relationship between building dampness and respiratory symptoms in young Swedish adults. In 1993, as a part of the European Community Respiratory Health Survey stage II, subjects were invited to participate in a detailed interview-led questionnaire, spirometry, methacholine challenge and measurement of total and specific IgE. A total of 1853 of the 2084 selected subjects participated in this study (88.9%). One hundred and thirty-six (7.4%) subjects reported water damage in their homes in the last year and 318 (17.3%) subjects reported visible molds during the same period. Seventy-four (4%) subjects reported both water damage and visible molds in the last year. This subgroup, with 74 subjects had significantly more attacks of breathlessness both when resting (OR 3.2 (95% CI 1.4-7.2)) and after effort (OR 2.7 (95% CI 1.3-5.6)) compared to subjects reporting no water damage or molds. Long-term cough was also more common in this group (OR 2.2 (95% CI 1.2-4.0)). This study adds evidence to a relationship between damp buildings and respiratory symptoms. 相似文献
44.
45.
Effect of smoking on exhaled nitric oxide and flow-independent nitric oxide exchange parameters. 总被引:2,自引:0,他引:2
A Malinovschi C Janson T Holmkvist D Norb?ck P Meril?inen M H?gman 《The European respiratory journal》2006,28(2):339-345
It is a well-known fact that smoking is associated with a reduction in exhaled nitric oxide (NO) levels. There is, however, limited knowledge relating to the smoking-induced changes in production or exchange of NO in different compartments of the airways. This study comprised 221 adult subjects from the European Community Respiratory Health Survey II, who were investigated in terms of their exhaled NO, lung function, immunoglobulin E sensitisation and smoking habits. The following parameters were determined using extended NO analysis: airway tissue nitric oxide concentration (Caw,NO), airway transfer factor (or diffusing capacity) for nitric oxide (Daw,NO), alveolar nitric oxide concentration (CA,NO) and fractional exhaled nitric oxide concentration at a flow rate of 50 mL x s(-1) (FeNO,0.05). Maximum total airway nitric oxide flux (J'aw,NO) was calculated from Daw,NO(Caw,NO-CA,NO). Current smokers (n = 35) exhibited lower (geometric mean) FeNO,0.05 (14.0 versus 22.8 ppb), Caw,NO (79.0 ;versus 126 ppb) and J'aw,NO (688 versus 1,153 pL x s(-1)) than never-smokers (n = 111). Ex-smokers (n = 75) were characterised by lower FeNO,0.05 (17.7 versus 22.8 ppb) and Jaw,NO (858 versus 1,153 pL x s(-1)) than never-smokers. These relationships were maintained after adjusting for potential confounders (sex, age, height, immunoglobulin E sensitisation and forced expiratory volume in one second), and, in this analysis, a negative association was found between current smoking and CA,NO. Snus (oral moist snuff) consumption (n = 21) in ex-smokers was associated with an increase in Daw,NO and a reduction in Caw,NO, after adjusting for potential confounders. Passive smoking was associated with a higher CA,NO. Using extended nitric oxide analysis, it was possible to attribute the reduction in exhaled nitric oxide levels seen in ex- and current smokers to a lower total airway nitric oxide flux in ex-smokers and reduced airway and alveolar nitric oxide concentrations in current smokers. The association between snus (oral tobacco) use and reduced nitric oxide concentrations in the airways and increased nitric oxide transfer from the airways warrants further studies. 相似文献
46.
Rita Amaral Tiago Jacinto Andrei Malinovschi Christer Janson David Price Joo A. Fonseca Kjell Alving 《Clinical and translational allergy》2021,11(4)
BackgroundBlood eosinophil (B‐Eos) count is an emerging biomarker in the management of respiratory disease but determinants of B‐Eos count besides respiratory disease are poorly described. Therefore, we aimed to evaluate the influence of non‐respiratory diseases on B‐Eos count, in comparison to the effect on two other biomarkers: fraction of exhaled nitric oxide (FeNO) and C‐reactive protein (CRP), and to identify individual characteristics associated with B‐Eos count in healthy controls.MethodsChildren/adolescents (<18 years) and adults with complete B‐Eos data from the US National Health and Nutritional Examination Surveys 2005–2016 were included, and they were divided into having respiratory diseases (n = 3333 and n = 7,894, respectively) or not having respiratory disease (n = 8944 and n = 15,010, respectively). After excluding any respiratory disease, the association between B‐Eos count, FeNO or CRP, and non‐respiratory diseases was analyzed in multivariate models and multicollinearity was tested. After excluding also non‐respiratory diseases independently associated with B‐Eos count (giving healthy controls; 8944 children/adolescents and 5667 adults), the independent association between individual characteristics and B‐Eos count was analyzed.ResultsIn adults, metabolic syndrome, heart disease or stroke was independently associated with higher B‐Eos count (12%, 13%, and 15%, respectively), whereas no associations were found with FeNO or CRP. In healthy controls, male sex or being obese was associated with higher B‐Eos counts, both in children/adolescents (15% and 3% higher, respectively) and adults (14% and 19% higher, respectively) (p < 0.01 all). A significant influence of race/ethnicity was also noted, and current smokers had 17% higher B‐Eos count than never smokers (p < 0.001).ConclusionsNon‐respiratory diseases influence B‐Eos count but not FeNO or CRP. Male sex, obesity, certain races/ethnicities, and current smoking are individual characteristics or exposures that are associated with higher B‐Eos counts. All these factors should be considered when using B‐Eos count in the management of respiratory disease. 相似文献
47.
48.
Eva Ludvigsen Carina Carlsson Eva Tiensuu Janson Stellan Sandler Mats Stridsberg 《Upsala journal of medical sciences》2015,120(3):157-168
Background
Somatostatin acts through five receptor subtypes (SSTRs 1–5). We aimed to investigate SSTRs mRNA expression and protein distribution in whole rat embryos, with special emphasis on the pancreas.Material and methods
Rat embryos were collected on embryonal days 10, 11, 12, 14, 15, 17, 19, 21, and at birth. Presence of SSTRs was investigated with RT-PCR techniques and immunohistochemistry.Results
There was no SSTR5 mRNA expression in the whole rat embryos. All SSTR1–5 proteins were observed at embryonal day 10, but the localization varied between the different subtypes. From day 11 to birth SSTRs protein presence increased with time in major structures such as skin and cartilage. It remained similar over time in the heart and liver. In the fetal pancreas mRNA expression of SSTR2 and 4 was detected at day 14, and there was an increase up to birth. Only SSTR1 protein co-localized to a higher extent with the islet hormones studied. SSTR2 was present in all islet endocrine cells except for β-cells. In contrast, the immunostaining for SSTR3–4 was co-localized with insulin and PP, and, finally, SSTR5 with glucagon and pancreatic polypeptide. In mRNA isolated from whole rat embryos SSTR1-2 and SSTR4 expression showed a peak at day 14, while SSTR3 mRNA was not present until day 15.Conclusion
The present data suggest a role for SSTRs during the development of the rat embryo. Subsequent functional studies may elucidate regulatory roles of specific SSTRs for the growth and differentiation of the pancreas as well as other organs. 相似文献49.
Spontaneous diabetes mellitus in transgenic mice expressing human islet amyloid polypeptide. 总被引:15,自引:0,他引:15 下载免费PDF全文
J Janson W C Soeller P C Roche R T Nelson A J Torchia D K Kreutter P C Butler 《Proceedings of the National Academy of Sciences of the United States of America》1996,93(14):7283-7288
The islet in non-insulin-dependent diabetes mellitus (NIDDM) is characterized by loss of beta cells and large local deposits of amyloid derived from the 37-amino acid protein, islet amyloid polypeptide (IAPP). We have hypothesized that IAPP amyloid forms intracellularly causing beta-cell destruction under conditions of high rates of expression. To test this we developed a homozygous transgenic mouse model with high rates of expression of human IAPP. Male transgenic mice spontaneously developed diabetes mellitus by 8 weeks of age, which was associated with selective beta-cell death and impaired insulin secretion. Small intra- and extracellular amorphous IAPP aggregates were present in islets of transgenic mice during the development of diabetes mellitus. However, IAPP derived amyloid deposits were found in only a minority of islets at approximately 20 weeks of age, notably after development of diabetes mellitus in male transgenic mice. Approximately 20% of female transgenic mice spontaneously developed diabetes mellitus at 30+ weeks of age, when beta-cell degeneration and both amorphous and amyloid deposits of IAPP were present. We conclude that overexpression of human IAPP causes beta-cell death, impaired insulin secretion, and diabetes mellitus. Large deposits of IAPP derived amyloid do not appear to be important in this cytotoxicity, but early, small amorphous intra- and extracellular aggregates of human IAPP were consistently present at the time of beta-cell death and therefore may be the most cytotoxic form of IAPP. 相似文献
50.