全文获取类型
收费全文 | 343篇 |
免费 | 24篇 |
专业分类
儿科学 | 5篇 |
妇产科学 | 4篇 |
基础医学 | 33篇 |
口腔科学 | 89篇 |
临床医学 | 20篇 |
内科学 | 95篇 |
皮肤病学 | 2篇 |
神经病学 | 7篇 |
特种医学 | 4篇 |
外科学 | 55篇 |
综合类 | 1篇 |
预防医学 | 19篇 |
眼科学 | 9篇 |
药学 | 15篇 |
肿瘤学 | 9篇 |
出版年
2023年 | 4篇 |
2022年 | 21篇 |
2021年 | 30篇 |
2020年 | 9篇 |
2019年 | 14篇 |
2018年 | 18篇 |
2017年 | 20篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 20篇 |
2013年 | 33篇 |
2012年 | 22篇 |
2011年 | 31篇 |
2010年 | 20篇 |
2009年 | 12篇 |
2008年 | 19篇 |
2007年 | 19篇 |
2006年 | 21篇 |
2005年 | 14篇 |
2004年 | 9篇 |
2003年 | 7篇 |
2002年 | 4篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1987年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1969年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有367条查询结果,搜索用时 15 毫秒
1.
Petru Matusz Nicoleta Iacob Gratian D. Miclaus Ana Pureca Horia Ples Marios Loukas R. Shane Tubbs 《Clinical anatomy (New York, N.Y.)》2013,26(8):975-979
The authors report a case of a 44‐year‐old male found to have unusual origins of the celiac trunk (CT) and superior mesernteric artrery (SMA) as revealed by routine multidetector computed tomograph (MDCT) angiography. The CT and SMA originate from the thoracic aorta (TA) 21 mm and 9 mm above the aortic hiatus, respectively. The median arcuate ligament (MAL) is located at the level of the L1–L2 intervertebral disc. The course of the CT descends in the thoracic cavity making a 14° acute downward angle in front of the TA; below the level of the MAL, the CT descends, making an angle of 47°. The course of the SMA descends at both the thoracic and abdominal level making an angle of 17°, and having an aortomesenteric distance of 9 mm at the level of the third part of the duodenum. In the present case, the supradiaphragmatic origin of the CT and the SMA was determined by their incomplete caudal descent, associated with a pronounced apparent descent of the diaphragm. A thoracic origin of the CT and SMA and the acute downward aortomesenteric angle (17°) associated with a reduced aortomesenteric distance at the level of the third part of the duodenum (9 mm), although no clinical signs are present, may predispose the patient to develop simultaneously a triple syndrome: the compression of CT by MAL (celiac axis compression syndrome), the compression of SMA by MAL (superior mesenteric artery compression syndrome), and the compression of the duodenum by the SMA (superior mesenteric artery syndrome). Clin. Anat. 26:975–979, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
2.
ObjectivesTo assess the effect of irradiation time and distance of the light tip on the micro-mechanical properties and polymerisation kinetics of two bulk-fill resin-based composites at simulated clinically relevant filling depth.MethodsMicro-mechanical properties (Vickers hardness (HV), depth of cure (DOC) and indentation modulus (E)) and polymerisation kinetics (real-time increase of degree of cure (DC)) of two bulk-fill resin-based composites (Tetric EvoCeram® Bulk Fill, Ivoclar Vivadent and x-tra base, Voco) were assessed at varying depth (0.1–6 mm in 100 μm steps for E and HV and 0.1, 2, 4 and 6 mm for DC), irradiation time (10, 20 or 40 s, Elipar Freelight2) and distances from the light tip (0 and 7 mm). Curing unit's irradiance was monitored in 1 mm steps at distances up to 10 mm away from the light tip on a laboratory-grade spectrometer.ResultsMultivariate analysis (α = 0.05), Student's t-test and Pearson correlation analysis were considered. The influence of material on the measured mechanical properties was significant (η2 = 0.080 for E and 0.256 for HV), while the parameters irradiation time, distance from the light tip and depth emphasise a stronger influence on Tetric EvoCeram® Bulk Fill. The polymerisation kinetics could be described by an exponential sum function, distinguishing between the gel and the glass phase. The above mentioned parameters strongly influenced the start of polymerisation (gel phase), and were of less importance for the glass phase.ConclusionsBoth materials enable at least 4 mm thick increments to be cured in one step under clinically relevant curing conditions.Clinical significanceThe susceptibility to variation in irradiance was material dependent, thus properties measured under clinically simulated curing conditions might vary to a different extent from those measured under ideal curing conditions. 相似文献
3.
Alciona Sasu Hildegard Herman Teodora Mariasiu Marcel Rosu Cornel Balta Nicoleta Anghel 《Drug and chemical toxicology》2015,38(4):442-451
Mucositis is a serious disorder of the gastrointestinal tract that results from cancer chemotherapy. We investigated the protective effects of silymarin on epirubicin-induced mucosal barrier injury in CD-1 mice. Immunohistochemical activity of both pro-apoptotic Bax and anti-apoptotic Bcl-2 markers, together with p53, cyt-P450 expression and DNA damage analysis on stomach, small intestine and colon were evaluated. Our results indicated stronger expression for cyt P450 in all analyzed gastrointestinal tissues of Epi group, which demonstrate intense drug detoxification. Bax immunopositivity was intense in the absorptive enterocytes and lamina connective cells of the small intestine, surface epithelial cells of the stomach and also in the colonic epithelium and lamina concomitant with a decreased Bcl-2 expression in all analyzed tissues. Epirubicin-induced gastrointestinal damage was verified by a goblet cell count and morphology analysis on histopathological sections stained for mucins. In all analyzed tissues, Bax immunopositivity has been withdrawn by highest dose of silymarin concomitant with reversal of Bcl-2 intensity at a level comparable with control. p53 expression was found in all analyzed tissues and decreased by high dose of silymarin. Also, DNA internucleosomal fragmentation was observed in the Epi groups for all analyzed tissues was almost suppressed at 100?mg/kg Sy co-treatment. Histological aspect and goblet cell count were restored at a highest dose of Sy for both small and large intestine. In conclusion, our findings suggest that silymarin may prevent cellular damage of epirubicin-induced toxicity and was effective in reducing the severity indicators of gastrointestinal mucositis in mice. 相似文献
4.
Nicoleta Oprescu Miruna Mihaela Micheu Alexandru Scafa-Udriste Nicoleta-Monica Popa-Fotea Maria Dorobantu 《Annals of medicine》2021,53(1):1042
IntroductionThe inflammatory hypothesis of atherosclerosis is appealing in acute coronary syndromes, but the dynamics and precise role are not established.ObjectivesThe study investigates the levels of C reactive protein (CRP), interleukin 1β (IL-1β) and stromal-derived factor 1α (SDF-1α) at the time of acute myocardial infarction (AMI) and at 1 and 6 months afterwards, compared with a control group.ResultsIn the acute phase of AMI, CRP and SDF-1α were significantly higher, while IL-1β showed lower levels compared with controls. CRP positively correlated with coronary stenosis severity (rho = 0.3, p=.05) and negatively related with left ventricle ejection fraction (LVEF) at 1 month (rho= −0.43, p=.05). IL-1β weakly correlated with the severity of coronary lesions (rho =0.29, p=.02) and strongly with LVEF (rho= −0.8, p=.05). SDF-1α, slightly correlated with LVEF at 1 month (rho = 0.22, p=.01) and with the severity of coronary atherosclerosis (rho= −0.41, p=.003).ConclusionsCRP, IL-1β and SDF-1α have important dynamic in the first 6 months after AMI and CRP and SDF-1α levels correlated with the severity of coronary lesions and LVEF at 1 month after the acute ischaemic event. 相似文献
5.
ObjectiveTo predict the clinically relevant transmitted irradiance that is available for luting when a CAD/CAM restoration is inserted. The influence of irradiance, exposure distance, light curing unit (LCU) angulation and direction of polymerization is analyzed when curing through crowns of different thicknesses.MethodsThree modern CAD/CAM resin-based composites (RBCs) were used to produce 45 crown-shaped specimens. The distance between fissure and crown base was set at 1.0, 1.5 and 2.0 mm (n = 5). Transmitted irradiance, while using a violet-blue LCU, was measured with a photo-spectrometer. 180 exposure conditions per specimen were investigated by variation in LCU curing mode, angulation, exposure distance and direction. Data was analyzed using univariate ANOVA followed by Tukey HSD (α = 0.05) and comparison of 95% confidence intervals.ResultsThe CAD/CAM-RBC’s decadic absorption coefficient ranges from 0.317 mm?1 to 0.387 mm?1 and the reflection correcting factor for crowns ranges from 0.305 to 0.337. Transmitted irradiance decreases significantly with increasing exposure distance and decreasing incident irradiance. For tilt angles greater than 10°, transmitted irradiances are significantly reduced (?11% for 20°, ?23% for 30°). Significantly lowest transmitted irradiances were measured for vestibular curing direction (up to ?15%).SignificanceA calculation model can predict the transmitted irradiance through a CAD/CAM restoration in dependence of restoration thickness and radiant emittance. The practitioner can be supported by this model to adapt material choice of dental restoration and adhesive system to the individual situation. Variation in exposure conditions shows negative effect on the transmission of light and should be limited. 相似文献
6.
Clinical Oral Investigations - To analyse the bond quality in dentine post-ageing after salivary contamination and decontamination at different stages of dental adhesive application. A total of... 相似文献
7.
8.
Background:
Randomized trials have established the benefit of medical therapy and revascularization in the treatment of acute myocardial infarction (MI). Cancer and cardiovascular disease are the 2 most common diseases worldwide. In clinical practice, cancer patients are frequently afflicted with MI. The benefit of medical and/or revascularization therapy in the cancer population with MI is less well known.Hypothesis:
Medical and revascularization therapy reduces mortality in cancer patients with MI.Methods:
After approval by the institutional review board, we retrospectively reviewed all patients with a discharge diagnosis of acute MI who were admitted to the University of Texas MD Anderson Cancer Center between December 2000 and October 2006 and evaluated the association between cardiac treatments with survival outcomes.Results:
A total of 456 patients with a discharge diagnosis of acute MI were identified and included in the study, of which 386 had non–ST‐segment elevation MI (NSTEMI) and 70 had ST‐segment elevation MI (STEMI). Compared with patients with NSTEMI, patients who had STEMI were more often prescribed aspirin (66% vs 43%; P = 0.004), β‐blockers (61% vs 46%; P = 0.018), and thrombolytic therapy (9% vs 0.3%; P = 0.0001). In the multivariable analysis, aspirin use was associated with a 23% decreased risk of death (hazard ratio [HR]: 0.77, 95% confidence interval [CI]: 0.60‐0.98, P = 0.033) and β‐blocker use was associated with a 36% decreased risk of death (HR: 0.64, 95% CI: 0.51–0.81, P = 0.0002). Statins (HR: 0.82, P = 0.18) and catheter‐based revascularization (HR: 0.57, P = 0.09) did not have an impact on the risk of death. Compared with patients with limited cancer, advanced cancer patients were twice as likely to die (HR: 2.12, 95 CI: 1.47–3.04, P < 0.0001). Previous chemotherapy (P = 0.005) and chest radiotherapy (P = 0.017) were associated with increased 1‐year mortality, whereas hyperlipidemia (P = 0.018) was protective.Conclusions:
In this study of cancer patients with MI, medical therapy with aspirin and β‐blockers was associated with improved survival. The authors have no funding, financial relationships, or conflicts of interest to disclose. 相似文献9.
Objectives
This study’s purpose was to evaluate the depth of cure (DOC) and the variation of mechanical properties with depth of two nano-hybrid resin-based composites (RBCs) containing a novel monomer composition based on dimer-acid derivatives (h-Da) or rather tricyclodecane–urethane structure (TCD-urethane) compared to three conventionally formulated nano-hybrid RBCs based on hardness-profile measurements.Materials and methods
Specimens were produced through different layering techniques (bulk, incremental) and curing times (10, 20, and 40?s). Mechanical properties (Vickers hardness (HV), modulus of elasticity (E)) were evaluated every 100?μm longitudinally throughout the bisected samples using an automatic micro-hardness indenter. DOC was determined as the depth at which the 80% hardness cutoff value in relation to the surface hardness was reached. Results were compared using one- and multiple-way ANOVA, Tukey HSD post-hoc test (α?=?0.05) and partial eta-squared statistic.Results
Increasing curing time resulted in a significant increase in DOC. Generally, the novel-formulated materials showed higher DOC values. “Curing time” and “material” showed the strongest effect on DOC. Starting in 4?mm depth, significantly higher HV and E was reached for incremental compared to bulk-curing technique. Values in 0.1 and 2?mm depth (bulk, incremental) as well as in 4?mm depth (incremental) were independent from curing time, while in greater depths, values generally increased with curing time. “Filling technique” and “material” performed the strongest influence on mechanical properties.Conclusions
Within the limits of this study, the novel-formulated RBCs showed better performance concerning DOC compared to conventional materials.Clinical relevance
For cavities deeper than 3?mm, all tested materials should be placed incrementally to ensure adequate polymerization. In large cavities (≥6?mm), the lowest increment should be cured at least 40?s. The novel-formulated RBCs might be cured in comparatively bigger increments. 相似文献10.