全文获取类型
收费全文 | 2131篇 |
免费 | 129篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 47篇 |
儿科学 | 95篇 |
妇产科学 | 86篇 |
基础医学 | 165篇 |
口腔科学 | 133篇 |
临床医学 | 237篇 |
内科学 | 505篇 |
皮肤病学 | 60篇 |
神经病学 | 200篇 |
特种医学 | 123篇 |
外科学 | 288篇 |
综合类 | 21篇 |
一般理论 | 1篇 |
预防医学 | 81篇 |
眼科学 | 65篇 |
药学 | 97篇 |
中国医学 | 1篇 |
肿瘤学 | 72篇 |
出版年
2024年 | 1篇 |
2023年 | 28篇 |
2022年 | 43篇 |
2021年 | 73篇 |
2020年 | 55篇 |
2019年 | 79篇 |
2018年 | 77篇 |
2017年 | 83篇 |
2016年 | 88篇 |
2015年 | 110篇 |
2014年 | 111篇 |
2013年 | 152篇 |
2012年 | 175篇 |
2011年 | 156篇 |
2010年 | 72篇 |
2009年 | 94篇 |
2008年 | 156篇 |
2007年 | 157篇 |
2006年 | 120篇 |
2005年 | 145篇 |
2004年 | 108篇 |
2003年 | 77篇 |
2002年 | 44篇 |
2001年 | 23篇 |
2000年 | 11篇 |
1999年 | 22篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1990年 | 2篇 |
1986年 | 1篇 |
排序方式: 共有2277条查询结果,搜索用时 15 毫秒
991.
Berna Kay Bedri Caner Kay Emel Yigit Karakas Sadettin Selcuk Baysal Dursun Cadirci Emre Erkus Ibrahim Halil Altiparmak Emin Savik Hatice Sezen Turgay Ulas 《老年心脏病学杂志》2015,12(4):373-377
Objective To evaluate the epicardial fat tissue thickness (EFTT) as a diagnostic criterion for geriatric patients with metabolic syndrome (MetS). Methods Sixty geriatric patients over 65 years of age were recruited for the study. Patients were divided into two groups: Group 1 (n = 30) consisted of patients with MetS; Group 2 (n = 30) consisted of patients without MetS. Echocardiography was used to measure EFTT in all patients, and blood samples were analyzed for biochemical parameters. Results Compared to Group 2, EFTT levels of Group 1 were statistically higher (P < 0.05). In a binary logistic regression analysis, EFTT levels served as the independent factor for metabolic syndrome (B = 17.35, SE = 4.93, Wald = 12.36, P < 0.001). Receivers operating characteristic Curve (ROC-curve) analysis revealed that EFTT predicted MetS with 96.7% sensitivity and 86.7% specificity above the level of 7.3 mm [area under the curve = 0.969; 95% confidence interval (CI): 0.928–1.00]. Conclusions The present study demonstrated that serum EFTT levels were higher in geriatric patients with MetS and can therefore be used as a diagnostic criterion for MetS. 相似文献
992.
Tolga Sinan Güvenç Hatice Betül ErerRengin Çetin MD Hakan HasdemirErkan İlhan MD Ceyhan TürkkanMehmet Eren MD FESC 《The Journal of emergency medicine》2013
Background
Aortic dissection is an important cause of acute chest pain that should be rapidly diagnosed, as mortality increases with each hour this condition is left untreated. The diagnosis can be challenging, especially if concomitant myocardial infarction is present. Echocardiography is an important tool for the differential diagnosis.Objectives
To stress the importance of recognizing aortic regurgitation for the differentiation of myocardial infarction and aortic dissection.Case Report
An 80-year-old woman was admitted to our hospital with chest pain that was diagnosed as inferior and lateral wall myocardial infarction based on electrocardiographic findings. The diagnosis was reevaluated when aortic regurgitation was detected on echocardiography. Closer inspection of the ascending aorta revealed a dissection flap as the cause of aortic regurgitation.Conclusion
Detection of aortic regurgitation in a patient with myocardial infarction and normal valves should prompt the search for a possible aortic dissection, whether or not the dissection flap can be visualized. 相似文献993.
Melda Türkoğlu Gülbin AygencelMurat Dizbay Ayşe Fitnat TuncelBurcu Arslan Candır Yelda Deligöz BildacıHatice Paşaoğlu 《Journal of critical care》2013
Purpose
A growing number of evidence demonstrates deficiency of vitamin D in critically ill patients. We aimed to evaluate the vitamin D status of our critically ill patients and its relevance to infections in these patients.Material and Methods
We conducted a prospective observational study in 201 critically ill patients admitted to the medical intensive care unit of Gazi University Hospital between October 2009 through March 2011.Results
Sixty-nine percent of the patients were found to be vitamin D deficient. Infection rate was higher in the deficient group, though without statistical significance (P = .117). Infections with Acinetobacter baumannii was significantly more frequent in patients with Vitamin D deficiency (25% vs 10%, P = .012). The median level of 25-hydroxyvitamin D levels was 11.8 [6.3-17.2] ng/mL and 15.7 [8.1-28.9] ng/mL in patients with and without A baumannii infections respectively (P = .024). Logistic regression analysis demonstrated that vitamin D deficiency (P = .042) and invasive mechanical ventilation (P = .001) were the 2 independent risk factors in the development of A baumannii infections, in addition.Conclusions
Vitamin D deficiency is common in critically ill patients. Even though there was no statistical difference between vitamin D deficient and sufficient patients regarding development of infections in general, A baumannii infections were significantly more frequent in the deficient group. Vitamin D deficiency was found as one of the independent risk factors for A baumannii infections. Further multicenter studies with a larger sample size are required to validate our data. 相似文献994.
Ozge Kurmus Ferik Kursat Akbuga Hatice Tolunay Turgay Aslan Murat Eren Aycan Fahri Erkan Berkay Ekici Ebru Akgul Ercan Celal Kervancoglu 《Medical principles and practice》2022,31(4):368
BackgroundMalnutrition is associated with cardiovascular disease morbidity and mortality. Arrhythmias may be the cardiac consequences of malnutrition.ObjectivesThe objective of the study was to evaluate the association between prognostic nutritional index (PNI), Controlling Nutritional Status (CONUT) score, and arrhythmic events on 24-h electrocardiography (ECG) Holter recording in patients without manifested arrhythmia.MethodsIn this retrospective analysis of 477 patients who underwent 24-h ECG Holter monitoring, PNI and CONUT score were calculated and patients were divided into tertiles according to PNI and into three groups according to CONUT score; 0: normal, 1–2: mild risk of malnutrition, ≥3: moderate-severe risk of malnutrition. Arrhythmic events were compared between PNI tertiles and CONUT score groups.ResultsTotal number of premature atrial contractions, premature ventricular contractions (PVCs), PVC burden, and incidence of paroxysmal atrial fibrillation (PAF) were significantly higher in patients within the lowest PNI tertile. Total number of PVCs, PVC burden, and incidence of PAF were significantly higher in patients with CONUT score ≥3. The cut-off value for PNI to predict the presence of PVC was defined as 39.41 using ROC curve analysis. The area under the curve was 0.650 (p < 0.001). Multivariate analysis showed that PNI was independent predictor of the presence of PVC and PAF. Also, CONUT score was independent predictor of the presence of PVC and PAF. Incidence of nonsustained ventricular tachycardia did not differ between PNI tertiles or CONUT score groups.ConclusionPoor nutritional status, assessed by PNI and CONUT score, is associated with arrhythmic events on 24-h ECG Holter recording in patients without manifested arrhythmia. 相似文献
995.
Sibel Türedi Hatice Hancı Serdar Çolakoğlu Haydar Kaya 《International journal of radiation biology》2016,92(6):329-337
The effects on human health of electromagnetic field (EMF) have begun to be seriously questioned with the entry into daily life of devices establishing EMF, such as cell phones, wireless fidelity, and masts. Recent studies have reported that exposure to EMF, particularly during pregnancy, affects the developing embryo/fetus. The aim of this study was therefore to examine the effects of exposure to continuous 900-Megahertz (MHz) EMF applied in the prenatal period on ovarian follicle development and oocyte differentiation. Six pregnant Sprague Dawley rats were divided equally into a non-exposed control group (CNGr) and a group (EMFGr) exposed to continuous 900-MHz EMF for 1?h daily, at the same time every day, on days 13–21 of pregnancy. New groups were established from pups obtained from both groups after birth. One group consisting of female pups from CNGr rats was adopted as newborn CNGr (New-CNGr, n?=?6), and another group consisting of female pups from EMFGr rats was adopted as newborn EMFGr (New-EMFGr, n?=?6). No procedure was performed on New-CNGr or New-EMFGr rats. All rat pups were sacrificed on the postnatal 34th day, and their ovarian tissues were removed. Follicle count, histological injury scoring and morphological assessment with apoptotic index criteria were performed with sections obtained following routine histological tissue preparation. Follicle count results revealed a statistically significant decrease in primordial and tertiary follicle numbers in New-EMFGr compared to New-CNGr (p?0.05), while atretic follicle numbers and apoptotic index levels increased significantly (p?0.05). Histopathological examination revealed severe follicle degeneration, vasocongestion, a low level of increased stromal fibrotic tissue and cytoplasmic vacuolization in granulosa cell in New-EMFGr. Prenatal exposure to continuous 900-MHz EMF for 1?h each day from days 13–21 led to a decrease in ovarian follicle reservoirs in female rat pups at the beginning of the prepubertal period. 相似文献
996.
Pinar Yazici Banu Yilmaz Emre Bozkurt Mehmet Mihmanli Mehmet Uludag 《Acta chirurgica Belgica》2016,116(1):30-35
Background Oncocytic (Hürthle) cell in fine-needle aspiration biopsy (FNAB) remains challenging for surgeons. Surgical treatment is recommended for oncocytic change in FNAB, since it can sometimes be a struggle to determine the nature of thyroid nodules. We aimed to investigate the clinical significance of oncocytic changes in FNAB in terms of management of patients.Methods The FNAB samples of 172 patients with thyroid nodules were reviewed. Of these, 39 patients with cytologic findings of oncocytic changes on FNAB [POC: predominance of oncocytic cells; SFON-H: suspicious for follicular or oncocytic neoplasm (Hürthle cell type), SM-O: suspicious for malignancy-papillary or follicular carcinoma; oncocytic variant)] were included.Results FNAB demonstrated POC in 14 (35.8%), SFON-H in 15 (38.4%), and SM-O in 10 (25.6%) patients. The overall malignancy rate was 35.8% (n?=?14). Clinical and laboratory data were not found to be associated with thyroid cancer while nodule size was significantly higher in patients with thyroid malignancy (15.2 versus 23.3?mm, p?=?0.032). Regarding FNAB results including oncocytic changes, the rate of malignancy was significantly different and almost three-fold higher in nodules classified as SFON-H and SM-O [48% versus 14.2% with POC, p?=?0.044]. Besides, there was a positive correlation between SFON-H and SM-O cytology and malignancy (p?=?0.036, r?=?0.337).Conclusions It is hard to discern the significance of oncocytic changes in FNAB report and to determine an optimal approach as a surgeon. We recommend surgery for the patients with an FNAB showing SFON-H and SM-O whereas POC should be better to be followed-up. 相似文献
997.
Ersan Tatli Armaan Altun Mutlu Büyüklü Ahmet Barotu 《Experimental & Clinical Cardiology》2007,12(2):97-99
OBJECTIVE
The aim of the present study was to assess the factors affecting collateral vessel development in patients with acute myocardial infarction.METHODS AND RESULTS: Between May 2001 and April 2004, coronary angiography was performed on 74 patients following myocardial infarction. Only patients with total proximal occlusion in the left anterior descending coronary artery (LAD) or right coronary artery (RCA) in angiography were included in the study. Patients were separated into two groups according to the development of coronary collateral circulation (CCC). In group 1, CCC was inadequate (Rentrop 0, 1 and 2); and in group 2, CCC was adequate (Rentrop 3). Although CCC was adequate in 20 of 28 (71%) patients who had RCA occlusion (P=0.015), it was adequate in only 14 of 46 (30%) patients who had LAD occlusion (P>0.05). The presence of angina pectoris was positively correlated with the development of CCC (P=0.03). Diabetes mellitus (DM) was present in 14 of 40 (35%) patients with inadequate CCC and four of 34 (11%) patients with adequate CCC. The presence of DM was significantly higher in the group with inadequate development of CCC (P=0.017).CONCLUSIONS
While DM was associated with an inadequate development of CCC, the presence of angina pectoris and RCA occlusion were associated with an adequate development of CCC. 相似文献998.
Comparison of adhesion and virulence of two predominant hospital-acquired methicillin-resistant Staphylococcus aureus clones and clonal methicillin-susceptible S. aureus isolates 下载免费PDF全文
Karauzum H Ferry T de Bentzmann S Lina G Bes M Vandenesch F Schmaler M Berger-Bächi B Etienne J Landmann R 《Infection and immunity》2008,76(11):5133-5138
The virulence of SCCmec type IV hospital-acquired methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates belonging to the major sequence type 8 (ST8 [Lyon clone]) and to a minor upcoming clone, ST5, was compared with that of methicillin-susceptible S. aureus (MSSA) isolates of matching sequence types. In vitro adhesion to human airway epithelial cells (HAECs) as an indicator of dissemination and mortality in a murine sepsis model as an indicator of virulence were evaluated. Ten MRSA isolates and 8 MSSA isolates of ST8 and 8 MRSA isolates and 8 MSSA isolates of ST5 were characterized with respect to multilocus sequence type; agr, spa, and capsule typing; in vitro doubling time; toxin and adhesin gene profiles; and adherence to HAECs. Adherence was significantly lower in the MRSA ST5 group than in the ST8 groups. Infections with MRSA and MSSA isolates ST8 and ST5 were compared. No change in virulence related to the presence of SCCmec was observed, since ST8 but not ST5 caused a significantly lower mortality in its presence. Despite their similar genetic backgrounds, individual clonal MRSA and MSSA isolates were heterogeneous in adherence and virulence. No one of these specific virulence factors determined in vitro was related to mouse mortality. In conclusion, in a bacteremic model, mortality was dependent on the ST and was differentially modulated by SCCmec; within an ST, clonality was not associated with a homogenous outcome. 相似文献
999.
Liang Y Hasturk H Elliot J Noronha A Liu X Wetzler LM Massari P Kantarci A Winter HS Farraye FA Ganley-Leal LM 《Clinical immunology (Orlando, Fla.)》2011,138(1):33-40
There is a need for developing vaccines that elicit mucosal immunity. Although oral or nasal vaccination methods would be ideal, current strategies have yielded mixed success. Toll-like receptor 2 (TLR2) ligands are effective adjuvants and are currently used in the Haemophilus influenzae type B vaccine. Induction of humoral immunity in the mucosa is critical for effective vaccination; thus, we sought to determine the effects of TLR2 ligands on human mucosal B cell differentiation. We demonstrate that TLR2 ligands induce CCR9 and CCR10 expression by circulating B cells and increased chemotaxis to cognate chemokines CCL25 and CCL28 suggesting that TLR2 induces B cell homing to the gastrointestinal tract. TLR2 stimulation of B cells also induced J chain and IgA production demonstrating the induction of mucosal-like antibody secreting cells. These observations suggest that vaccines containing TLR2-ligands as adjuvants could induce mucosal B cell immunity even when delivered in a non-mucosal manner. 相似文献
1000.
Hatice Kalkan Yıldırım Yasemin Delen Akçay Ulgar Güvenç Eser Yıldırım Sözmen 《International journal of food sciences and nutrition》2013,64(5):351-362
Current research suggests that phenolics from wine may play a positive role against oxidation of low-density lipoprotein (LDL), which is a key step in the development of atherosclerosis. Considering the effects of different wine-making techniques on phenols and the wine consumption preference influencing the benefical effects of the product, organically and non-organically produced wines were obtained from the grapes of Vitis vinifera origin var: Carignan, Cabernet Sauvignon, Merlot, Grenache, Columbard and Semillon. Levels of total phenols [mg/l gallic acid equivalents (GAE)], antioxidant activity (%) and inhibition of LDL oxidation [%, inhibition of diene and malondialdehyde (MDA) formation] were determined. Some phenolic acids (gallic acid, p-hydroxybenzoic acid, syringic acid, 2,3-dihydroxybenzoic acid, ferulic acid, p-coumaric acid and vanillic acid) were quantified by high-performance liquid chromatography equipped with an electrochemical detection carried at +0.65 V (versus Ag/AgCl, 0.5 μA full scale).The highest concentrations of gallic, syringic and ferulic acids were found in organic Cabernet Sauvignon; 2,3-dihydroxybenzoic acid in organic Carignan and p-coumaric and vanillic acids in non-organic Merlot wine. High levels of antioxidant activity (AOA), inhibition of LDL oxidation and total phenol levels were found in non-organic Merlot (101.950% AOA; 88.570% LDL-diene; 41.000% LDL-MDA; 4700.000 mg/l GAE total phenol) and non-organic Cabernet Sauvignon (92.420% AOA; 91.430% LDL-diene; 67.000% LDL-MDA; 3500.000 mg/l GAE total phenol) grape varieties. Concentrations of some individual phenolic constituents (ferulic, p-coumaric, vanillic) are correlated with high antioxidant activity and inhibition of LDL oxidation.The best r value for all examined characteristics was determined for gallic acid, followed by 2,3-dihydroxybenzoic, syringic, ferulic and p-coumaric acids. Negative correlation of vanillic with MDA and p-hydroxybenzoic acid with LDL were confirmed by principal component analysis (PCA) analyses. Red wines display a higher antioxidant activity (81.110% AOA) than white ones (19.512% AOA). The avarage level of LDL inhibition capacity in red wine was determined as 87.072% and for the white as 54.867%. 相似文献