全文获取类型
收费全文 | 1915篇 |
免费 | 80篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 39篇 |
妇产科学 | 29篇 |
基础医学 | 279篇 |
口腔科学 | 92篇 |
临床医学 | 172篇 |
内科学 | 338篇 |
皮肤病学 | 100篇 |
神经病学 | 176篇 |
特种医学 | 94篇 |
外科学 | 306篇 |
综合类 | 11篇 |
预防医学 | 47篇 |
眼科学 | 96篇 |
药学 | 107篇 |
中国医学 | 4篇 |
肿瘤学 | 112篇 |
出版年
2023年 | 15篇 |
2022年 | 42篇 |
2021年 | 68篇 |
2020年 | 40篇 |
2019年 | 48篇 |
2018年 | 53篇 |
2017年 | 42篇 |
2016年 | 48篇 |
2015年 | 60篇 |
2014年 | 53篇 |
2013年 | 79篇 |
2012年 | 120篇 |
2011年 | 143篇 |
2010年 | 97篇 |
2009年 | 74篇 |
2008年 | 113篇 |
2007年 | 136篇 |
2006年 | 108篇 |
2005年 | 105篇 |
2004年 | 97篇 |
2003年 | 81篇 |
2002年 | 71篇 |
2001年 | 14篇 |
2000年 | 21篇 |
1999年 | 34篇 |
1998年 | 18篇 |
1997年 | 25篇 |
1996年 | 21篇 |
1995年 | 22篇 |
1994年 | 13篇 |
1993年 | 10篇 |
1992年 | 5篇 |
1990年 | 8篇 |
1989年 | 5篇 |
1988年 | 10篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1982年 | 4篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1976年 | 3篇 |
1975年 | 5篇 |
1974年 | 6篇 |
1969年 | 5篇 |
1968年 | 3篇 |
1967年 | 3篇 |
1966年 | 3篇 |
排序方式: 共有2009条查询结果,搜索用时 15 毫秒
81.
Maximilian Kreibich Klaus Kaier Constantin von zur Mühlen Matthias Siepe Manfred Zehender Christoph Bode Friedhelm Beyersdorf Peter Stachon Wolfgang Bothe 《Interactive Cardiovascular and Thoracic Surgery》2022,34(3):349
Open in a separate windowOBJECTIVESTo evaluate in-hospital outcomes of concomitant mitral valve replacement (MVR) in patients undergoing conventional aortic valve replacement due to aortic stenosis in a nationwide cohort.METHODSAdministrative data from all patients with aortic stenosis undergoing conventional aortic and concomitant MVR (reason for MVR not specified) between 2017 and 2018 in Germany were analysed.RESULTSA total of 2597 patients with a preoperative logistic EuroScore of 9.81 (standard deviation: 8.56) were identified. In-hospital mortality was 6.8%. An in-hospital stroke occurred in 3.4%, acute kidney injury in 16.3%, prolonged mechanical ventilation of more than 48 h in 16.3%, postoperative delirium in 15.8% and postoperative pacemaker implantation in 7.6% of the patients. Mean hospital stay was 16.5 (standard deviation: 12.1) days. Age [odds ratio (OR): 1.03; P = 0.019], New York Heart Association class III or IV (OR: 1.63; P = 0.012), previous cardiac surgery (OR: 2.85, P = 0.002), peripheral vascular disease (OR: 2.01, P = 0.031), pulmonary hypertension (OR: 1.63, P = 0.042) and impaired renal function (glomerular filtration rate <15, OR: 3.58, P = 0.001; glomerular filtration rate <30, OR: 2.51, P = 0.037) were identified as independent predictors for in-hospital mortality.CONCLUSIONSIn this nationwide analysis, concomitant aortic and MVR was associated with acceptable in-hospital mortality, morbidity and length of in-hospital stay. The regression analyses may help to identify high-risk patients and further optimize treatment strategies. 相似文献
82.
83.
Antje?Stolzenburg Katharina?Lückerath Samuel?Samnick Martin?Speer Katharina?Kneer Jan-Stefan?Schmid G?tz?Ulrich?Grigoleit Susanne?Hofmann Ambros?J.?Beer Donald?Bunjes Stefan?Knop Andreas?K.?Buck Hermann?Einsele Constantin?LapaEmail authorView authors OrcID profile 《European journal of nuclear medicine and molecular imaging》2018,45(10):1694-1704
Purpose
Despite improved treatment options, multiple myeloma (MM) remains an incurable disease. The aim of this study was to investigate the prognostic value of positron emission tomography/computed tomography (PET/CT) using 18F-2’-deoxy-2’-fluorodeoxyglucose ([18F]FDG) in MM patients shortly before and ~100 days after allogeneic hematopoietic cell transplantation (allo-HCT).Methods
In this retrospective analysis, we evaluated [18F]FDG-PET/CT-scans of 45 heavily pre-treated MM patients before and 27 patients after scheduled allo-HCT. All scans were qualitatively and semi-quantitatively assessed for the presence of active disease. Serological response was recorded according to International Myeloma Working Group (IMWG) criteria. Progression-free (PFS) and overall survival (OS) were correlated with different PET/CT-derived parameters, such as presence, number and maximum standardized uptake value (SUVmax) of focal myeloma lesions. The impact of extramedullary disease on patient outcome was also assessed.Results
PET/CT negativity -prior to or following allo-HCT- was a favorable prognostic factor for progression-free and overall survival (both, PFS and OS: pre-HSCT p?<?0.001, post-HCT p?<?0.005). High FDG-uptake (SUVmax?>?6.5) revealed a significantly shortened survival compared to patients with a lower SUVmax (<6.5) (OS, 5.0?±?1.1 m vs. not reached - longest 122.0 m; p?<?0.001). Moreover, our data prove that a higher number (>3) of focal lesions (pre-HCT: both PFS and OS: p?<?0.001; post-HCT PFS: p?<?0.001, OS: p?=?0.139) as well as the presence of extramedullary disease serve as adverse prognostic factors prior to and after allo-HCT. At response assessment after allo-HCT, [18F]FDG-PET/CT had a complementary value in prognostication in addition to IMWG criteria alone.Conclusion
[18F]FDG-PET/CT before and shortly after allogeneic HCT is a powerful predictor for progression-free and overall survival in MM patients.84.
Gutzeit A Sutter R Froehlich JM Roos JE Sautter T Schoch E Giger B Wyss M Graf N von Weymarn C Jenelten R Binkert CA Hergan K 《European radiology》2011,21(9):1979-1987
Objective
To prospectively determine the diagnostic value of electrocardiography-triggered non-contrast-enhanced magnetic resonance angiography (TRANCE) of the lower extremities including the feet versus DSA.Methods
All 43 patients with symptomatic peripheral arterial occlusive disease (PAOD) underwent TRANCE before DSA. Quality of MRA vessel depiction was rated by two independent radiologists on a 3-point scale. Arterial segments were graded for stenoses using a 4-point scale (grade 1: no stenosis; grade 2: moderate stenosis; grade 3: severe stenosis; grade 4: occlusion). Findings were compared with those of DSA.Results
In the 731 vessel segments analysed, intra-arterial DSA revealed 283 stenoses: 33.6% moderate, 16.6% severe and 49.8% occlusions. TRANCE yielded a mean sensitivity, specificity, positive and negative predictive value and diagnostic accuracy to detect severe stenoses or occlusions of 95.6%, 97.4%, 87.2%, 99.2%, 97.1% for the thigh segments and 95.2%, 87.5%, 83.2%, 96.6%, 90.5% for the calf segments. Excellent overall image quality was observed for TRANCE in 91.4% versus 95.7% (DSA) for the thigh and in 60.7% versus 91.0% for the calves, while diagnostic quality of the pedal arteries was rated as insufficient.Conclusion
TRANCE achieves high diagnostic accuracy in the thigh and calf regions, whereas the pedal arteries showed limited quality. 相似文献85.
Michael A. Amygdalos Ziv J. Haskal M.D. Constantin Cope Steven L. Kadish William B. Long 《Cardiovascular and interventional radiology》1996,19(2):107-109
Two patients with pancreatic malignancies presented with biliary obstruction which could not be treated from an endoscopic
approach. Standard transhepatic biliary drainage was relatively contraindicated because of moderate ascites and coagulopathy
related to underlying liver disease. In one patient, a transjugular, transvenous approach was used to deliver a Wallstent
endoprosthesis across the distal common bile duct obstruction in a single step procedure. In the second case, a previously
placed biliary Wallstent was revised with an additional stent from a similar approach. Transjugular biliary catheterization
offers a valuable alternative approach for primary stent placement or revision in patients with contraindication to standard
transhepatic drainage. 相似文献
86.
Constantin Tamvakopoulos Konstantinos Dimas Zacharias D Sofianos Sophia Hatziantoniou Zhiyong Han Zhong-Li Liu James H Wyche Panayotis Pantazis 《Clinical cancer research》2007,13(4):1269-1277
PURPOSE: The plant-derived compound curcumin has shown promising abilities as a cancer chemoprevention and chemotherapy agent in vitro and in vivo but exhibits poor bioavailability. Therefore, there is a need to investigate modified curcumin congeners for improved anticancer activity and pharmacokinetic properties. EXPERIMENTAL DESIGN: The synthetic curcumin analogue dimethoxycurcumin was compared with curcumin for ability to inhibit proliferation and apoptosis of human HCT116 colon cancer cells in vitro by estimating the GI(50) and LC(50) values and detecting the extent of apoptosis by flow cytometry analysis of the cell cycle. Metabolic stability and/or identification of metabolites were evaluated by recently developed mass spectrometric approaches after incubation with mouse and human liver microsomes and cancer cells in vitro. Additionally, circulating levels of dimethoxycurcumin and curcumin were determined in mice following i.p. administration. RESULTS: Dimethoxycurcumin is significantly more potent than curcumin in inhibiting proliferation and inducing apoptosis in HCT116 cells treated for 48 h. Nearly 100% of curcumin but <30% of dimethoxycurcumin was degraded in cells treated for 48 h, and incubation with liver microsomes confirmed the limited metabolism of dimethoxycurcumin. Both compounds were rapidly degraded in vivo but dimethoxycurcumin was more stable. CONCLUSIONS: Compared with curcumin, dimethoxycurcumin is (a) more stable in cultured cells, (b) more potent in the ability to kill cancer cells by apoptosis, (c) less extensively metabolized in microsomal systems, and (d) more stable in vivo. It is likely that the differential extent of apoptosis induced by curcumin and dimethoxycurcumin in vitro is associated with the metabolite profiling and/or the extent of stability. 相似文献
87.
PURPOSE: We surveyed a group of German ophthalmologists to evaluate their prescribing philosophies for hyperopic refractive error in symptom-free children and to compare them with the two groups of U.S. pediatric ophthalmologists and U.S. pediatric optometrists as surveyed by Lyons et al. METHODS: Practitioners were selected from a list of ophthalmologists on the Internet. They were either in general practice in three cities in northern Bavaria or affiliated with large ophthalmology teaching hospitals in Wuerzburg and Erlangen. The survey questions of Lyons et al. were translated into German and mailed to 103 ophthalmologists. The data received from the German ophthalmologists were compared with those of the U.S. optometrists and ophthalmologists. RESULTS: A total of 45 surveys (44%) were returned to us and analyzed. In cases of asymptomatic bilateral hyperopia, German ophthalmologists did not prescribe significantly differently from U.S. optometrists at all patient age groups (p > or = 0.05), but they did differ significantly from U.S. ophthalmologists (p < 0.001). Prescribing fractional amounts of hyperopia or astigmatism was not a popular rule of thumb among the German ophthalmologists, and there was no statistical difference between the German and U.S. practitioners. German ophthalmologists would prescribe for anisometropia for all patient age groups in the same way as both U.S. optometrists and U.S. ophthalmologists. CONCLUSION: The prescribing philosophies of German ophthalmologists for pediatric patients did not differ from those of U.S. ophthalmologists and U.S. optometrists when prescribing for anisometropia; they did differ from those of U.S. ophthalmologists but not of those of the U.S. optometrists when prescribing for asymptomatic bilateral hyperopia. 相似文献
88.
Guy Donati Anastasios Kapetanios Michel Dubois‐Dauphin Constantin Jean Pournaras 《Acta ophthalmologica. Supplement》2008,86(3):302-306
Purpose: Acute brain ischaemia (stroke) causes a central area of coagulation necrosis. Peripheral to it and after a few hours, apoptosis causes neurons throughout the entire area to die progressively. However, this sequence of events is related to the reperfusion of regenerated capillaries or collateral circulation, and is considered to be potentially salvageable. Similar findings have been reported in the retina after ischaemia?reperfusion injury in rats. In the present study, we intended to investigate whether delayed cell death is involved in neuronal injuries to the inner retina during chronic retinal ischaemia. Methods: Experimental branch retinal vein occlusion (BRVO) was induced in miniature pigs using indirect argon laser. The eyes were prelevated at 4, 24 and 48 hours and at 1 and 3 weeks following BRVO. The caspase inhibitor Z‐VAD was injected intravitreally 24 hours after BRVO. Affected retinas were examined 24 hours later for any protective effect from apoptotic cell death. Histological examination with cresyl violet staining and TUNEL (TdT‐mediated dUTP?biotin nick‐end labelling) was performed on the samples. Results: A progressive oedema of the nerve fibre, ganglion cell and inner plexiform layers, related to a widely diffused cell necrosis, was observed in the affected territory within 4–24 hours after BRVO. This was followed by a wave of apoptosis localized at the periphery of the affected territory, which peaked approximately 48 hours after BRVO and was associated with a diffuse oedema of the inner nuclear layer. A progressive atrophy of the inner retina was observed 1–3 weeks after BRVO. Injection of the caspase inhibitor Z‐VAD (24 hours after BRVO) decreased the amount of apoptotic cell bodies 48 hours after BRVO. Conclusions: This study shows that although necrosis is the predominant form of neuronal death in the early phase, massive delayed neuronal cell death caused by apoptosis occurs on a widespread basis as a result of chronic ischaemia after BRVO in the retina. Further studies are needed to evaluate the possibility of rescuing retinal neurons from death by neuroprotective treatments. 相似文献
89.
Changes to visual acuity and the visual field in a case of meningioma operated at the anterior level
Rosca T Corbu C Constantin M Preda A Curca M Banacu I Rechil A 《Oftalmologia (Bucharest, Romania : 1990)》2000,51(2):89-94
It's presented a midline meningioma of anterior level case which preoperative has an importance affectation of the visual acuity and visual field, and postoperative in dynamic is founded the important improvement of visual acuity and visual field. It's discussed visual field topography and atrophy optic pathophysiology. It's a neuro-ophthalmology case example, where the cooperation neurosurgery-ophthalmology permit medical solution and restored in social life of the patient. 相似文献
90.
Central serous chorioretinopathy and glucocorticoids 总被引:11,自引:0,他引:11
Central serous chorioretinopathy is a relatively common retinal disease characterized by the accumulation of subretinal fluid at the posterior pole of the fundus, creating a circumscribed area of serous retinal detachment. It typically affects young and middle-aged men with no previous medical and family history, and no systemic symptoms or signs. However, it has been noted that central serous chorioretinopathy is associated with different conditions, characterized by exposure to increased levels of endogenous or exogenous glucocorticoids. In fact, central serous chorioretinopathy has been described in patients with endogenous Cushing's syndrome. It is also prevalent in patients with type-A behavior, and following stressful events, and pregnancy probably represents a risk factor for central serous chorioretinopathy; these conditions are characterized by endogenous hypercortisolism. In addition, many cases of central serous chorioretinopathy have been described during or following treatment with glucocorticoids, administrated by any route, for various systemic or ocular conditions. Central serous chorioretinopathy, when related to the exposure to exogenous glucocorticoids, has a less prominent male predilection, presents more often with a chronic or atypical form, and is frequently bilateral. Furthermore, treatment of central serous chorioretinopathy with glucocorticoids was found to exacerbate the clinical picture. Based on these observations it could be suggested that glucocorticoids may be involved in the development of central serous chorioretinopathy, even though the exact pathogenic mechanism remains unclear. Glucocorticoids should not be used in the treatment of central serous chorioretinopathy and central serous chorioretinopathy should be added to the list of ocular complications of glucocorticoids. 相似文献