全文获取类型
收费全文 | 2294篇 |
免费 | 96篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 111篇 |
儿科学 | 87篇 |
妇产科学 | 117篇 |
基础医学 | 203篇 |
口腔科学 | 83篇 |
临床医学 | 175篇 |
内科学 | 530篇 |
皮肤病学 | 19篇 |
神经病学 | 168篇 |
特种医学 | 125篇 |
外科学 | 521篇 |
综合类 | 32篇 |
预防医学 | 45篇 |
眼科学 | 97篇 |
药学 | 64篇 |
中国医学 | 8篇 |
肿瘤学 | 38篇 |
出版年
2024年 | 4篇 |
2023年 | 15篇 |
2022年 | 25篇 |
2021年 | 43篇 |
2020年 | 32篇 |
2019年 | 28篇 |
2018年 | 62篇 |
2017年 | 45篇 |
2016年 | 80篇 |
2015年 | 93篇 |
2014年 | 97篇 |
2013年 | 132篇 |
2012年 | 153篇 |
2011年 | 148篇 |
2010年 | 110篇 |
2009年 | 74篇 |
2008年 | 202篇 |
2007年 | 192篇 |
2006年 | 188篇 |
2005年 | 187篇 |
2004年 | 150篇 |
2003年 | 153篇 |
2002年 | 97篇 |
2001年 | 12篇 |
2000年 | 10篇 |
1999年 | 6篇 |
1998年 | 10篇 |
1997年 | 14篇 |
1996年 | 11篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1974年 | 3篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
1939年 | 1篇 |
1937年 | 1篇 |
1936年 | 2篇 |
1928年 | 1篇 |
排序方式: 共有2423条查询结果,搜索用时 31 毫秒
991.
Sevket Balli Ilker Kemal Yucel Ayse Esin Kibar Ibrahim Ece Eylem Sen Dalkiran Sukru Candan 《World journal of pediatrics : WJP》2016,12(4):463-469
Background
Extra genetic material in patients with Down syndrome (DS) may affect the function of any organ system. We evaluated cardiac functions using conventional tissue Doppler and two-dimensional speckle tracking echocardiography in patients with DS in the absence of congenital and acquired heart disease in patients.Methods
A total of 115 patients with DS between 6 and 13 years of age with clinically and anatomically normal heart and 55 healthy children were included in this cross-sectional study. DS was diagnosed by a karyotype test. Patients with mosaic type were not included in this study. Systolic and diastolic functions were evaluated by echocardiography.Results
Pulsed waved Doppler transmitral early/late inflow velocity (E/A), tissue Doppler mitral annular early/late diastolic peak velocity (Ea/Aa), transtricuspid E/A and tricuspid valve annulus Ea/Aa, pulmonary venous Doppler systolic/diastolic (S/D) wave ratio were lower in patients with Down syndrome than in the control group (P=0.04, P=0.001, P<0.05, P<0.001, P<0.001, respectively). Mitral and tricuspid annular Ea were lower in patients with DS (P<0.001). The right and left ventricular myocardial performance indexes were higher in patients with DS than in the controls (P<0.01). They had significantly higher left ventricular mass, ejection fraction, the mitral annular plane systolic excursion values. However, the Down syndrome group compared with the controls had a lower strain values examined by two-dimensional longitudinal speckle-tracking strain echocardiography.Conclusion
These findings suggest conventional tissue Doppler and two-dimensional longitudinal speckletracking strain echocardiography were useful methods of investigating ventricular function and identifying a higher incidence of biventricular dysfunction in patients with Down syndrome compared with the healthy controls.992.
993.
994.
Salim Kemal Tuncer Seher Altinel Mehmet Toygar Hakan Istanbulluoglu Kahraman Ates Recai Ogur Ozcan Altinel Yildirim Karslioglu Turgut Topal Ahmet Korkmaz Bulent Uysal 《Inflammopharmacology》2016,24(4):155-161
Objectives
Paraquat (PQ) is a widely used herbicide. Exposure to PQ at toxic doses can result in fatal acute lung injury. Inhibition of the poly-(ADP-ribose) polymerase (PARP) enzyme alleviates inflammation and necrosis in various pathologies. Here we aimed to evaluate the effects of PARP inhibition on PQ-induced lung damage in a rat experimental model.Methods
Female Sprague-Dawley rats (n = 24) were allocated into three groups: sham, PQ and PQ + 3-aminobenzamide (3-AB) that is a PARP inhibitor, groups. Experimental lung injury was induced by administration of 15 mg/kg PQ intraperitoneally in PQ and PQ + 3-AB groups. 3-AB (10 mg/kg twice per day) was administered to the PQ + 3-AB group for four consecutive days. The animals were killed on the fifth day following PQ administration. Lung tissue and blood samples were collected and stored until analysis.Results
Serum lactate dehydrogenase (LDH) and neopterin levels, tissue oxidative stress parameters, transforming growth factor-beta1 (TGF-β) levels and histological injury scores in the PQ + 3-AB group were significantly lower than in the PQ group (P < 0.05, PQ vs. PQ + 3-AB). Total antioxidant capacity in the PQ + 3-AB group was significantly higher than in the PQ group (P < 0.05, PQ + 3-AB vs. PQ).Conclusion
Our results suggested that the use of PARP inhibitors following PQ toxicity might be useful for minimizing lung injury due to paraquat toxicity.995.
Tolga Kocaturk Kemal Ergin Gokhan Cesur Gokhan Evren Evlicoglu Harun Cakmak 《Cutaneous and ocular toxicology》2016,35(1):36-40
Purpose: To investigate the effect of methimazole-induced postnatal hypothyroidism on the retinal maturation and to study Sirtuin 2 (SIRT2) level in the hypothyroidic rat retina.Methods: Twenty newborn Wistar albino rat pups were used in this prospective, randomized study. Wistar albino rats, weight 250–300?g, were impregnated (without addition of any drug) and were fed normally. Rat pups were randomly divided into two groups and were fed with breast milk. After weaning till they were 90 days of age, rat pups received the same water as their lactating mothers drank. Group 1 (methimazole (MMI)-induced hypothyroidy group), rats were given MMI-water, whereas, in Group 2, normal tap water. When the pups were 90 days of age, 20 rat pups were decapitated and the eyes were isolated. Eyes were investigated using histological, histomorphometric and immunohistochemistrical techniques.Results: No histological difference was seen between the groups stained with hematoxylin and eosin. In both groups the retinal layer structures and cells were observed as normal. The examples in the groups had a normal distribution for retinal thickness (pixel) measure. The mean value (mean?±?std. deviation) was 554.7?±?228.4 in the control group and 494.7?±?129.4 in the hypothyroidy group. There was no significance between the groups in terms of retinal thickness (p?=?0.231). However, immunohistochemistry revealed that SIRT2 was weaker stained in the ganglion cell layer and visual cell layer in the hypothyroidy group compared to the control group.Conclusion: Postnatal hypothyroidism altered the retinal cytoarchitecture and layering which are regulated by thyroid hormones (THs) during retinal maturation in the postnatal period. THs may act by the induction of the SIRT family proteins or through their receptors. Postnatal screenings for THs levels are very important to provide normal retinal development. 相似文献
996.
The aim of this study was to investigate the response of human pulp tissue to a dentin bonding agent, Scotchbond Multi-Purpose Plus (SMPP), in exposed class V cavities. Sixteen human premolar teeth were mechanically exposed. Ten pulps were capped with SMPP and six teeth were capped with Dycal. The cavities were filled with a composite. After 40 days, the teeth were extracted and processed for histologic evaluation. Of the 10 teeth capped with SMPP, eight showed moderate chronic inflammation, one was severely inflamed, and one pulp had no to slight inflammation. None of the teeth capped with SMPP showed dentin bridge formation. Of the six teeth capped with Dycal, three exhibited incomplete dentin bridges associated with no to slight inflammation, and three showed no to slight inflammation, without formation of dentin bridges. Direct capping with Dycal with subsequent sealing with SMPP may show favorable results in pulp tissue. SMPP may cause inflammatory changes when applied directly to exposed pulp tissue. 相似文献
997.
Feridun Hürmüzlü A Kemal Ozdemir Ihsan Hubbezoglu Akin Coskun Seyda Hergüner Siso 《Quintessence international, dental digest》2007,38(4):e206-e212
OBJECTIVE: Currently, the trend in dentin adhesion seems to be shifting from moist bonding systems to self-etching systems and from several application steps to single steps. However, recent studies have indicated that the performance of single-step adhesives was lower than the 2-step self-etch or total etch systems. In the present study, microtensile bond strength of a total etch, 2-step self-etch and single-step self-etch adhesives was comparatively evaluated. METHOD AND MATERIALS: The superficial occlusal dentin of 12 noncarious extracted human molars was exposed, finished with wet 600-grit silicon carbide paper, and a block of resin composite bonded with adhesives according to the manufacturers' instructions. The teeth were kept in tap water for 24 hours at 37 degrees C and sectioned to produce beams, with adhesive areas of +/- 0.9 mm2 (4 beams per tooth were obtained). The specimens were stressed at a crosshead speed of 1 mm per minute until the bonds ruptured. RESULTS: The mean bond strengths were calculated as MPa and compared by performing analysis of variance and Tukey tests to identify significant differences between the materials (P = 0.05). The mean bond strength of Clearfil SE Bond was significantly higher than that of OptiBond Solo Plus and iBond (P <.05). OptiBond Solo Plus gave significantly higher bond strengths than iBond (P <.05). CONCLUSIONS: The self-etching adhesive system Clearfil SE Bond (2 step) had higher bond strength than the 1-bottle self-etching adhesive iBond (single application) and the 2-step single-bottle system OptiBond Solo Plus (total etch). However, the 1-bottle adhesive system OptiBond Solo Plus (total etch system) had higher bond strength than the 1-bottle self-etching adhesive system iBond. 相似文献
998.
999.
Onur Dede Ahmet Ali Sancaktutar Okan Baş Mansur Dağgüllu Mazhar Utangaç Necmettin Penbegul Haluk Soylemez Namık Kemal Hatipoglu Mehmet Nuri Bodakci Yaşar Bozkurt Murat Atar Gülay Dede 《Urological research》2016,44(2):173-177
This study aimed to investigate the effectiveness and reliability of micro-percutaneous nephrolithotomy (micro-PNL) for the management of kidney stones in pediatric patients. This retrospective study included 24 infants that underwent micro-PNL for renal stones between March 2012 and April 2015. The inclusion criteria included: age younger than 2 years, stone size <20 mm, absence of urinary tract malformations and active infection, and no coagulopathy. Stone-free rates were assessed one month postoperatively by ultrasonography (USG) and kidneys, ureters, bladder (KUB) radiography. Complications were classified according to the Clavien classification system. The mean age of the patients was 15.8 ± 7.8 months (range, 8–23) and the mean stone size was 13.5 ± 3.84 mm. Intra-renal access was achieved using USG in 11 patients and KUB fluoroscopy in 13 patients. The operation time and fluoroscopic screening time were 53.7 ± 10.35 and 1.4 ± 0.9 min, respectively. The mean hospital stay was 2.5 ± 0.8 days, and the mean drop in the hemoglobin level was 0.51 ± 0.34 g/dL. Bleeding requiring blood transfusion was not observed. A ureteral J stent was implanted perioperatively in four patients because of stone burden. Four patients complained of postoperative renal colic (Clavien grade 1) and postoperative fever was observed in two patients. Definitive success rates were as follows: the stone-free rate was 83.3 % (n = 20) and residual fragments were observed in four patients. 相似文献
1000.