全文获取类型
收费全文 | 987篇 |
免费 | 81篇 |
国内免费 | 13篇 |
专业分类
儿科学 | 26篇 |
妇产科学 | 6篇 |
基础医学 | 59篇 |
口腔科学 | 5篇 |
临床医学 | 54篇 |
内科学 | 186篇 |
皮肤病学 | 6篇 |
神经病学 | 37篇 |
特种医学 | 106篇 |
外科学 | 107篇 |
综合类 | 24篇 |
预防医学 | 131篇 |
眼科学 | 171篇 |
药学 | 35篇 |
肿瘤学 | 128篇 |
出版年
2022年 | 7篇 |
2021年 | 13篇 |
2020年 | 8篇 |
2019年 | 16篇 |
2018年 | 23篇 |
2017年 | 13篇 |
2016年 | 18篇 |
2015年 | 13篇 |
2014年 | 25篇 |
2013年 | 22篇 |
2012年 | 68篇 |
2011年 | 65篇 |
2010年 | 33篇 |
2009年 | 34篇 |
2008年 | 59篇 |
2007年 | 68篇 |
2006年 | 58篇 |
2005年 | 46篇 |
2004年 | 64篇 |
2003年 | 42篇 |
2002年 | 32篇 |
2001年 | 45篇 |
2000年 | 33篇 |
1999年 | 21篇 |
1998年 | 20篇 |
1997年 | 16篇 |
1996年 | 19篇 |
1995年 | 16篇 |
1994年 | 10篇 |
1993年 | 4篇 |
1992年 | 24篇 |
1991年 | 15篇 |
1990年 | 16篇 |
1989年 | 14篇 |
1988年 | 15篇 |
1987年 | 14篇 |
1986年 | 11篇 |
1985年 | 11篇 |
1984年 | 8篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1979年 | 3篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1975年 | 2篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1970年 | 2篇 |
1968年 | 2篇 |
1965年 | 2篇 |
排序方式: 共有1081条查询结果,搜索用时 15 毫秒
71.
72.
Brand JS van der Schouw YT Dowsett M Folkerd E Luben RN Wareham NJ Khaw KT 《Maturitas》2012,71(3):274-278
Objective
Low-grade chronic inflammation is increasingly being implicated in cardiovascular disease (CVD) etiology and may represent an alternative pathway through which testosterone and sex hormone-binding globulin (SHBG) influence CVD risk. We examined the associations between endogenous testosterone, SHBG and total and differential white blood cell (WBC) counts in men.Methods
Cross-sectional study of 2418 men aged 40–78 years from the Norfolk population of European Prospective Investigation into Cancer (EPIC-Norfolk) who had no history of CVD or cancer and complete data on sex hormones (total testosterone (TT), SHBG and free testosterone (FT)) and WBC counts. Associations between sex hormones and WBC counts were assessed using linear regression models.Results
Higher SHBG and TT levels were associated with lower WBC counts. After adjustment for age, BMI, smoking, physical activity and diabetes status, total WBC count decreased by 0.163 (95% CI −0.236; −0.091) and 0.102 (−0.170; −0.034) per standard deviation (SD) increase in SHBG and TT respectively. Associations of SHBG and TT with total WBC count were mainly accounted for by a lower granulocyte count (β coefficient = −0.132 (−0.194; −0.070) per SD increase in SHBG and β coefficient = −0.104 (−0.161; −0.046) per SD increase in TT). No associations between FT and total and differential WBC counts were found.Conclusions
Endogenous TT and SHBG levels are inversely associated with total WBC and granulocyte count in middle-aged and older men. Even though the underlying mechanism and causal directionality requires further exploration, these results support a link between hormonal status and low-grade inflammation. 相似文献73.
The paediatric glaucomas present some of the greatest clinical challenges. We review the advances in the management of the paediatric glaucomas, which have improved the outlook for these patients and their families. These advances include improvements in diagnosis, investigations, anaesthetic techniques, medical, surgical, and laser therapies. 相似文献
74.
Ward H Chapelais G Kuhnle GG Luben R Khaw KT Bingham S;European Prospective into Cancer-Norfolk cohort 《Breast cancer research : BCR》2008,10(2):R32-9
Introduction
Phytoestrogens are a group of compounds found in plants that structurally resemble the hormone oestradiol, and thus have the potential to act as oestrogen agonists or antagonists. Their potential effects may alter the risk of breast cancer, but only a limited range of phytoestrogens has been examined in prospective cohort studies.Methods
Serum and urine samples from 237 incident breast cancer cases and 952 control individuals (aged 45 to 75 years) in the European Prospective into Cancer-Norfolk cohort were analysed for seven phytoestrogens (daidzein, enterodiol, enterolactone, genistein, glycitein, o-desmethylangolensin, and equol) using liquid chromatography/mass spectrometry. Data on participants' diet, demographics, anthropometrics, and medical history were collected upon recruitment. All models were adjusted for weight, fat and energy intake, family history of breast cancer, social class, analytical batch, and factors related to oestrogen exposure.Results
Urinary or serum phytoestrogens were not associated with protection from breast cancer in the European Prospective into Cancer-Norfolk cohort. Breast cancer risk was marginally increased with higher levels of total urinary isoflavones (odds ratio = 1.08 (95% confidence interval = 1.00 to 1.16), P = 0.055); among those with oestrogen receptor-positive tumours, the risk of breast cancer was increased with higher levels of urinary equol (odds ratio = 1.07 (95% confidence interval = 1.01 to 1.12), P = 0.013).Conclusion
There was limited evidence of an association between phytoestrogen biomarkers and breast cancer risk in the present study. There was no indication of decreased likelihood of breast cancer with higher levels of phytoestrogen biomarkers, but the observation that some phytoestrogen biomarkers may be associated with greater risk of breast cancer warrants further study with greater statistical power. 相似文献75.
Chajès V Biessy C Byrnes G Deharveng G Saadatian-Elahi M Jenab M Peeters PH Ocké M Bueno-de-Mesquita HB Johansson I Hallmans G Manjer J Wirfält E Jakszyn P González CA Huerta JM Martinez C Amiano P Suárez LR Ardanaz E Tjønneland A Halkjaer J Overvad K Jakobsen MU Berrino F Pala V Palli D Tumino R Vineis P de Magistris MS Spencer EA Crowe FL Bingham S Khaw KT Linseisen J Rohrmann S Boeing H Nöethlings U Olsen KS Skeie G Lund E Trichopoulou A Zilis D Oustoglou E Clavel-Chapelon F Riboli E 《Nutrition and cancer》2011,63(8):1235-1250
Elaidic acid is the main unnatural trans fatty acid isomer occurring during partial hydrogenation of vegetable oils used as ingredients for the formulation of processed foods. The main objective is to assess associations between processed food intakes and plasma phospholipid elaidic acid concentrations within the European Prospective Investigation into Cancer and Nutrition study. A cross-sectional study was used to determine fatty acid profiles in 3,003 subjects from 16 centers. Single 24-h dietary recalls (24-HDR) were collected using a standardized computerized interview program. Food intakes were computed according to their degree of processing (moderately/nonprocessed foods, processed staple foods, highly processed foods). Adjusted ecological and individual correlations were calculated between processed food intakes and plasma elaidic acid levels. At the population level, mean intakes of highly processed foods were strongly correlated with mean levels of plasma elaidic acid in men (P = 0.0016) and in women (P = 0.0012). At the individual level, these associations remained but at a much lower level in men (r = 0.08, P = 0.006) and in women (r = 0.09, P = 0.0001). The use of an averaged 24-HDR measure of highly processed food intakes is adequate for predicting mean levels of plasma elaidic acid among European populations. 相似文献
76.
We randomized women having elective Caesarean section to receiveeither no preload (control group, n=33) or 4% gelatin solution(Gelofusine) 15 ml kg1 (colloid group, n=35)i.v. before spinal anaesthesia. Intravenous metaraminol wastitrated at 0.250.75 mg min1 to maintainsystolic arterial pressure (SAP) in the target range 90100%of baseline after the spinal injection. The control group requiredmore vasopressor in the first 10 min [median 1.7 (range 02.9)mg vs 1.4 (02.8), P=0.02] at a greater maximum infusionrate [0.5 (00.75) vs 0.25 (00.5) mg min1,P=0.0005] and had a lower minimum SAP [90 (51109) vs101 (75127) mm Hg, P=0.006] than the colloid group. Nauseawas less frequent in the colloid group (6 vs 24%) but neonataloutcome was similar in the two groups. Colloid preload improvedhaemodynamic stability but did not affect neonatal outcome whenarterial pressure was maintained with an infusion of metaraminolduring spinal anaesthesia for Caesarean section. Br J Anaesth 2001; 87: 7724 相似文献
77.
Linseisen J Rohrmann S Bueno-de-Mesquita B Büchner FL Boshuizen HC Agudo A Gram IT Dahm CC Overvad K Egeberg R Tjønneland A Boeing H Steffen A Kaaks R Lukanova A Berrino F Palli D Panico S Tumino R Ardanaz E Dorronsoro M Huerta JM Rodríguez L Sánchez MJ Rasmuson T Hallmans G Manjer J Wirfält E Engeset D Skeie G Katsoulis M Oikonomou E Trichopoulou A Peeters PH Khaw KT Wareham N Allen N Key T Brennan P Romieu I Slimani N Vergnaud AC Xun WW Vineis P Riboli E 《Cancer causes & control : CCC》2011,22(6):909-918
Evidence from case-control studies, but less so from cohort studies, suggests a positive association between meat intake and risk of lung cancer. Therefore, this association was evaluated in the frame of the European Prospective Investigation into Cancer and Nutrition, EPIC. Data from 478,021 participants, recruited from 10 European countries, who completed a dietary questionnaire in 1992-2000 were evaluated; 1,822 incident primary lung cancer cases were included in the present evaluation. Relative risk estimates were calculated for categories of meat intake using multi-variably adjusted Cox proportional hazard models. In addition, the continuous intake variables were calibrated by means of 24-h diet recall data to account for part of the measurement error. There were no consistent associations between meat consumption and the risk of lung cancer. Neither red meat (RR = 1.06, 95% CI 0.89-1.27 per 50 g intake/day; calibrated model) nor processed meat (RR = 1.13, 95% CI 0.95-1.34 per 50 g/day; calibrated model) was significantly related to an increased risk of lung cancer. Also, consumption of white meat and fish was not associated with the risk of lung cancer. These findings do not support the hypothesis that a high intake of red and processed meat is a risk factor for lung cancer. 相似文献
78.
Gailloud P Muster M Khaw N Martin JB Murphy KJ Fasel JH Rüfenacht DA 《Neuroradiology》2001,43(2):139-143
We studied the anatomic relationship between arachnoid granulations in the transverse sinus and the termination of the vein of Labbé in 57 consecutive angiograms. Patients with pathology in intracranial venous structures or with inadequate image quality of the venous system were excluded. Arachnoid granulations were found in 12 of the 57 patients (21.1%), always at the junction of the vein of Labbé and the transverse sinus; the vein of Labbé was present in 55 patients (96.5%), most often without associated arachnoid granulations; the latter, however, were not observed in the absence of a vein of Labbé. This study confirms the close, constant anatomic relationship between arachnoid granulations in the transverse sinus and the termination of the vein of Labbé. This observation may help to differentiate arachnoid granulations from pathologic conditions involving the transverse sinus such as dural sinus thrombosis. The constant character of this relationship suggests a developmental role of afferent veins in the formation of arachnoid granulations. 相似文献
79.
80.
Karim El Harchaoui Wim A van der Steeg Erik S G Stroes Jan Albert Kuivenhoven James D Otvos Nicholas J Wareham Barbara A Hutten John J P Kastelein Kay-Tee Khaw S Matthijs Boekholdt 《Journal of the American College of Cardiology》2007,49(5):547-553
OBJECTIVES: We assessed relations of low-density lipoprotein (LDL) particle number (LDL-P) and LDL particle size as measured by nuclear magnetic resonance spectroscopy with LDL cholesterol (LDL-C) and the risk of future coronary artery disease (CAD). BACKGROUND: Whereas LDL-C is an established risk factor for CAD, its discriminative power is limited. Measuring LDL-P and size may have stronger associations with CAD than LDL-C. METHODS: A nested case-control study was performed in the prospective EPIC (European Prospective Investigation into Cancer and Nutrition)-Norfolk study, which comprises 25,663 subjects. Cases (n = 1,003) were individuals who developed CAD during 6 year follow-up. Control subjects (n = 1,885) were matched for age, gender, and enrollment time. Odds ratios (ORs) for future CAD were calculated, and we also evaluated whether LDL-P could improve the Framingham risk score (FRS) to predict CAD. RESULTS: In univariate analyses, LDL-P (OR 2.00, 95% confidence interval [CI] 1.58 to 2.59) and non-high-density lipoprotein cholesterol (non-HDL-C) (OR 2.14, 95% CI 1.69 to 2.69) were more closely associated with CAD than LDL-C (OR 1.73, 95% CI 1.37 to 2.18). The additional value of LDL-P was lost after adjustment for HDL-C and triglyceride levels. Whereas LDL size was inversely related to CAD (OR 0.60, 95% CI 0.47 to 0.76), this relation was abolished upon adjustment for LDL-P. In a model adjusted for the FRS, LDL-P retained its association with CAD (p for trend 0.02). CONCLUSIONS: In this large study of individuals with moderately elevated LDL-C, LDL-P was related to CAD on top of FRS as well as after adjusting for LDL-C. The additional value of LDL-P was comparable to non-HDL-C, and it was abolished after adjusting for triglycerides and HDL-C. 相似文献