全文获取类型
收费全文 | 1019篇 |
免费 | 51篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 20篇 |
妇产科学 | 39篇 |
基础医学 | 109篇 |
口腔科学 | 12篇 |
临床医学 | 61篇 |
内科学 | 269篇 |
皮肤病学 | 14篇 |
神经病学 | 59篇 |
特种医学 | 29篇 |
外国民族医学 | 2篇 |
外科学 | 121篇 |
综合类 | 69篇 |
预防医学 | 109篇 |
眼科学 | 16篇 |
药学 | 78篇 |
中国医学 | 24篇 |
肿瘤学 | 48篇 |
出版年
2023年 | 21篇 |
2022年 | 41篇 |
2021年 | 25篇 |
2020年 | 20篇 |
2019年 | 102篇 |
2018年 | 103篇 |
2017年 | 30篇 |
2016年 | 23篇 |
2015年 | 24篇 |
2014年 | 71篇 |
2013年 | 39篇 |
2012年 | 53篇 |
2011年 | 49篇 |
2010年 | 24篇 |
2009年 | 22篇 |
2008年 | 27篇 |
2007年 | 15篇 |
2006年 | 20篇 |
2005年 | 45篇 |
2004年 | 83篇 |
2003年 | 65篇 |
2002年 | 27篇 |
2001年 | 23篇 |
2000年 | 4篇 |
1999年 | 13篇 |
1998年 | 4篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 10篇 |
1994年 | 9篇 |
1993年 | 7篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 9篇 |
1984年 | 10篇 |
1983年 | 11篇 |
1982年 | 13篇 |
1981年 | 9篇 |
1980年 | 4篇 |
1979年 | 1篇 |
1978年 | 5篇 |
1977年 | 1篇 |
1976年 | 4篇 |
1974年 | 2篇 |
1972年 | 2篇 |
排序方式: 共有1098条查询结果,搜索用时 15 毫秒
21.
Y Suzuki I. Sasagawa H. Yazawa T. Tateno T. Nakada H. Saito M. Hiroi 《Systems biology in reproductive medicine》2013,59(2):133-136
Localization of the sex-determining region Y (SRY) was investigated in 2 XX males. Metaphase chromosomes from peripheral lymphocytes were stained by fluorescence in situ hybridization using DXZ1 and SRY probes. An identical hybridization signal with the SRY probe was found on an X chromosome in both cases. The karyotype of the 2 cases was 46,XX, t(X;Y)(p22.3;p11.3). It would appear that XX male is the presence of a Y-chromosome fragment transferred to the X-chromosome short arm by unequal interchange between homologous regions in the short arms of sex chromosomes. 相似文献
22.
目的评价经食管二维超声心动图(2D-TEE)在二尖瓣成形术中的临床应用价值。方法共收集二尖瓣脱垂并中度以上返流行心脏外科二尖瓣成形手术的患者35例。术中行2D-TEE检测二尖瓣病变类型与扇叶分区定位,与手术发现进行对照,并于术后即刻评价二尖瓣成形手术效果。结果35例患者中发现病变部位共40处,36处病变部位与术中所见相符(符合率90%),其中5例(14%)术后监测发现2级以上瓣膜返流,立即改行人工瓣置换术。结论2D-TEE在二尖瓣成形术中具有对病变部位分区定位、指导术式选择,具有缩短手术时间、提高手术成功率的重要临床应用价值。 相似文献
23.
A. Q. Yaffee L. K. Whiteside R. A. Oteng P. M. Carter P. Donkor S. D. Rominski M. E. Kruk R. M. Cunningham 《Tropical medicine & international health : TM & IH》2012,17(6):775-781
Objective To characterise the population that presents to the Accident and Emergency Centre (AEC) at Komfo Anokye Teaching Hospital (KATH) and to identify risk factors associated with bypassing proximal care facilities. Methods A structured questionnaire was verbally administered to patients presenting to the AEC over 2 weeks. The questionnaire focused on the use of health care resources and characteristics of current illness or injury. Measures recorded include demographics, socioeconomic status, chief complaint, transportation and mobility, reasons for choosing KATH and health care service utilisation and cost. Results The total rate of bypassing proximal care was 33.9%. On multivariate analysis, factors positively associated with bypassing included age older than 38 years (OR: 2.18, P 0.04) and prior visits to facility (OR 2.88, P 0.01). Bypassers were less likely to be insured (OR 0.31, P 0.01), to be seeking care due to injury (OR 0.42, P 0.03) and to have previously sought care for the problem (OR 0.10, P < 0.001). Conclusions Patients who bypass facilities near them to seek care at an urban AEC in Ghana do so for a combination of reasons including familiarity with the facility, chief complaint and insurance status. Understanding bypassing behaviour is important for guiding health care utilisation policy decisions and streamlining cost‐effective, appropriate access to care for all patients. 相似文献
24.
《Annals of medicine》2013,45(5):349-356
It is well established that elevated plasma levels of low-density lipoprotein (LDL) particles are a risk factor for ischaemic heart disease with the distribution in LDL levels seen in the general population being the result of interaction between environmental factors, such as dietary fat intake, and genetic variation that is present in different individuals. One of the candidate genes where such variation is likely to occur, is the gene coding for apolipoprotein B (apo B). Many studies have reported an association between a common polymorphism of the apo B gene, detected using the restriction enzyme Xbal, and differences in plasma lipid levels, explaining 3-5% of the variance in LDL-cholesterol levels in samples representative of the healthy population. It has been proposed that the mechanism of this association is due to functional amino acid changes within the apo B protein, that affect LDL catabolism by altering binding affinity to the LDL-receptor. Several amino acid substitutions in the apo B gene have now been characterized, and these form the basis of the different epitopes that create the Ag marker system. Previous studies have reported that the Ag(x) epitope is associated with lower plasma lipid levels, and until recently the molecular basis for this association has been unclear. We have determined that the Ag(x) epitope is associated with both a Pro-Leu2712, and Asn-Ser4311 substitution, with the Leu-Ser allele being associated with significantly lower levels of plasma lipids in a sample of healthy individuals from Sweden. The association between these two amino acids is present in all ethnic groups so far studied, and appears to have been maintained throughout the recent evolutionary history of the human species. Since this amino acid polymorphism explains only part of the differences in plasma lipid levels detected using the Xbal polymorphism, this suggests that there are other functionally important sequence changes that remain to be detected, which will be associated with lipid-raising effects. The identification of these functional changes, and the mechanism by which they act will help in our understanding of the role of gene-environment interaction in determining plasma lipid levels in healthy individuals and in patients. 相似文献
25.
Objective
To evaluate the impact of the Youth Form Strategy (EFJ, Estrategia Forma Joven) on the attitudes and behaviours of students in the fourth year of compulsory secondary school in Seville, Spain.Methods
A longitudinal observational design was used with two groups; one received the EFJ (EFJ group) and other did not (non-EFJ group). In the initial evaluation, 402 participants were randomly selected and, in the follow-up at 6 months, 322 participants were evaluated (161 per group). Validated data collection tools were used, and 2 × 2 tables, odds ratio (OR) and general ANOVA for 2 × 2 mixed factorial design (p < 0.05) were calculated.Results
Favourable effects of the EFJ were found: in the area of sexuality, the percentage of participants who had sexual intercourse in the final assessment was lower in the EFJ group (14.9% vs 23.4%; OR = 0.57), as were counter-effects: start of tobacco use was higher in the EFJ group (19.5% vs 9.1%; OR = 2.43). However, these differences were not statistically significant.Conclusions
The similarities in the school health promotion programme in centres with and without EFJ may have influenced the lack of conclusive results. Individual and/or group counselling at schools, a distinguishing feature of the EFJ, could have delayed sexual intercourse in the EFJ group. Based on the studies on school health promotion activities, good practices that could help to improve the effectiveness of the EFJ are recommended. 相似文献26.
27.
《Gaceta sanitaria / S.E.S.P.A.S》2015,29(5):347-352
BackgroundStudies of the prevalence of HIV in sentinel populations are one of the key strategies to monitor the HIV epidemic. We describe HIV prevalence trends and identify differences across time in the sociodemographic characteristics of HIV-infected women giving birth in Catalonia.MethodsWe used dried blood specimens, residual to newborn screening, which have been collected in Catalonia every 2 months since 1994. The total number of samples obtained until 2009 and in 2013 represented half of yearly newborns. From 2010 to 2012, the total number of samples obtained represented a quarter of yearly newborns. We studied the prevalence by year and place of current residence (Barcelona-city, cities > 200,000 inhabitants and cities ≤ 200,000 inhabitants) and by the mother's birth country. A total of 624,912 infants were tested for HIV antibodies from January 1994 to December 2013.ResultsHIV prevalence trends among women giving birth in Catalonia decreased until 2007. Thereafter, there was a change to a steady trend until 2013. However, among foreign women giving birth and living in cities ≤ 200,000 inhabitants, the prevalence of HIV increased from 2007 to 2013.ConclusionTo ensure early identification and treatment of HIV-infected mothers, it is essential to maintain HIV surveillance programs and pre- and post-natal screening programs, both in Barcelona and in cities with 200,000 inhabitants or less, especially in immigrant women. 相似文献
28.
Many trace elements are considered essential [iron (Fe), zinc (Zn), copper (Cu)], whereas others may be harmful [lead (Pb), cadmium (Cd), mercury (Hg), arsenic (As)], depending on their concentration and chemical form. In most cases, the diet is the main pathway by which they enter our organism. The presence of toxic trace elements in food has been known for a long time, and many of the food matrices that carry them have been identified. This has led to the appearance of legislation and recommendations concerning consumption. Given that the main route of exposure is oral, passage through the gastrointestinal tract plays a fundamental role in their entry into the organism, where they exert their toxic effect. Although the digestive system can be considered to be of crucial importance in their toxicity, in most cases we do not know the events that occur during the passage of these elements through the gastrointestinal tract and of ascertaining whether they may have some kind of toxic effect on it. The aim of this review is to summarize available information on this subject, concentrating on the toxic trace elements that are of greatest interest for organizations concerned with food safety and health: Pb, Cd, Hg and As. 相似文献
29.
Sari RA Kiziltunç A Taysi S Taysý S Akdemir S Akdemýr S Gündoğdu M 《Clinical rheumatology》2005,24(1):55-59
Behçets disease is a systemic vasculitis of unknown aetiology. Endothelial cell injury plays an important role in the pathogenesis and immunopathology of Behçets disease. E-selectin is expressed by activated endothelial cells. Because the selectin adhesion molecules are shed from activated cells, soluble forms of these proteins can be used as activation markers of endothelium (E-selectin). The pathogenesis of Behçets disease (BD) is closely related to endothelial cells, leucocyte functions and immunity. The aim of this study was to investigate circulating E-selectin adhesion molecules, which are known to play a significant part in the immune response especially by regulating interaction of the leucocytes with endothelium in BD. Plasma E-selectin concentrations were evaluated in 23 patients with BD and 20 healthy control subjects. The disease activity was evaluated by clinical manifestations (oral aphthous ulcer, genital ulceration, positive pathergy test, skin lesions, eye involvement, thrombophlebitis and arthritis) and by laboratory investigations [erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)]. The patients were newly or previously diagnosed cases not taking any drug for BD. Levels of E-selectin were measured with commercially available sandwich enzyme-linked immunosorbent assay (ELISA) kits using human sE-selectin (cat. no: BMS 205). Plasma E-selectin concentrations of patients and controls were compared with the Mann-Whitney U test. Statistical significance was assigned to p values lower than 0.05. Serum levels (mean±SD) of soluble E-selectin (sE-selectin) were significantly higher in 23 patients with BD than in 20 healthy controls (53.2±18.2 ng/ml vs 33.8±7.5 ng/ml, p<0.0001). A statistically significant positive correlation was observed between sE-selectin levels and CRP and ESR in patients with BD (r=0.78, p<0.001 and r=0.56, p<0.01, respectively). Increases in the E-selectin in BD may be a direct consequence of the leucocyte and endothelium activations observed during the disease process. The noninvasive investigations can be used as biochemical markers for inflammation. This may provide additional information regarding disease activity along with the traditional indices such as ESR and CRP. 相似文献
30.
Kranzer K McGrath N Saul J Crampin AC Jahn A Malema S Mulawa D Fine PE Zaba B Glynn JR 《Tropical medicine & international health : TM & IH》2008,13(11):1341-1350
Objective To investigate individual, household and community factors associated with HIV test refusal in a counselling and testing programme offered at population level in rural Malawi. Methods HIV counselling and testing was offered to individuals aged 18–59 at their homes. Individual variables were collected by interviews and physical examinations. Household variables were determined as part of a previous census. Multivariate models allowing for household and community clustering were used to assess associations between HIV test refusal and explanatory variables. Results Of 2303 eligible adults, 2129 were found and 1443 agreed to HIV testing. Test refusal was less likely by those who were never married [adjusted odds ratio (aOR) 0.50 for men (95% CI 0.32; 0.80) and 0.44 (0.21; 0.91) for women] and by farmers [aOR 0.70 (0.52; 0.96) for men and 0.59 (0.40; 0.87) for women]. A 10% increase in cluster refusal rates increased the odds of refusal by 1.48 (1.32; 1.66) in men and 1.68 (1.32; 2.12) in women. Women counsellors increased the odds of refusal by 1.39 (1.00; 1.92) in men. Predictors of HIV test refusal in women were refusal of the husband as head of household [aOR 15.08 (9.39; 24.21)] and living close to the main road [aOR 6.07 (1.76; 20.98)]. Common reasons for refusal were fear of testing positive, previous HIV test, knowledge of HIV serostatus and the need for more time to think. Conclusion Successful VCT strategies need to encourage couples counselling and should involve participation of men and communities. 相似文献