全文获取类型
收费全文 | 907篇 |
免费 | 57篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 19篇 |
妇产科学 | 22篇 |
基础医学 | 111篇 |
口腔科学 | 28篇 |
临床医学 | 94篇 |
内科学 | 259篇 |
皮肤病学 | 11篇 |
神经病学 | 44篇 |
特种医学 | 30篇 |
外科学 | 85篇 |
综合类 | 6篇 |
预防医学 | 110篇 |
眼科学 | 12篇 |
药学 | 35篇 |
肿瘤学 | 88篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 16篇 |
2021年 | 25篇 |
2020年 | 7篇 |
2019年 | 22篇 |
2018年 | 23篇 |
2017年 | 10篇 |
2016年 | 24篇 |
2015年 | 26篇 |
2014年 | 44篇 |
2013年 | 55篇 |
2012年 | 71篇 |
2011年 | 78篇 |
2010年 | 56篇 |
2009年 | 29篇 |
2008年 | 72篇 |
2007年 | 82篇 |
2006年 | 75篇 |
2005年 | 62篇 |
2004年 | 66篇 |
2003年 | 37篇 |
2002年 | 33篇 |
2001年 | 13篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 7篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1981年 | 1篇 |
1977年 | 1篇 |
1973年 | 2篇 |
1970年 | 1篇 |
排序方式: 共有968条查询结果,搜索用时 31 毫秒
131.
Spyrou G Kapsimalakou S Frigas A Koufopoulos K Vassilaros S Ligomenides P 《Medical & biological engineering & computing》2006,44(11):1007-1015
One of the most common cancer types among women is breast cancer. Regular mammographic examinations increase the possibility for early diagnosis and treatment and significantly improve the chance of survival for patients with breast cancer. Clustered microcalcifications have been considered as important indicators of the presence of breast cancer. We present “Hippocrates-mst”, a prototype system for computer-aided risk assessment of breast cancer. Our research has been focused in developing software to locate microcalcifications on X-ray mammography images, quantify their critical features and classify them according to their probability of being cancerous. A total of 260 cases (187 benign and 73 malignant) have been examined and the performance of the prototype is presented through receiver operating characteristic (ROC) analysis. The system is showing high levels of sensitivity identifying correctly 98.63% of malignant cases. 相似文献
132.
A 43-year-old woman was undergoing radiofrequency catheter ablation of a symptomatic supraventricular tachycardia when a patent foramen ovale (PFO) was detected with passage of the diagnostic electrocatheter into the left atrium. Prior echocardiographic studies had been unrevealing. Upon questioning during the procedure, the patient now admitted to frequent and disabling daily migraine attacks, while her family described two recent brief episodes of disorientation and dysarthria, consistent with transient ischemic attacks. The patient was informed of the option of future closure of the PFO, but she insisted on having this done concurrently with her ablation procedure. After successful ablation of the slow pathway considered responsible for the supraventricular tachycardia, an Amplatzer closure device was utilized and the PFO was successfully closed during the same procedure. A postprocedural transesophageal echocardiogram showed complete sealing of the PFO, while over the ensuing 10 months the patient reported virtual elimination of her daily attacks of migrainous headaches, limited to a single episode the day after the procedure and none thereafter. 相似文献
133.
Rentzos M Paraskevas GP Kapaki E Nikolaou C Zoga M Rombos A Tsoutsou A Vassilopoulos D D 《Journal of the neurological sciences》2006,249(2):110-114
Interleukin-12 is a heterodimeric cytokine produced by activated blood monocytes, macrophages and glial cells. It enhances differentiation and proliferation of T cells and increases production of proinflammatory cytokines, such as Interferon-gamma and Tumor Necrosis Factor-alpha. There is little information about the involvement of IL-12 in the pathophysiology of Alzheimer's disease (AD) and other tauopathies. OBJECTIVES: The objective of our study was to assess the role of IL-12 as a potential marker of immune reactions in patients with AD and frontotemporal dementia (FTD). PATIENTS AND METHODS: We measured by immunoassay cerebrospinal fluid (CSF) IL-12 levels in 19 patients with AD and 7 patients with FTD in comparison with CSF IL-12 levels in 30 patients with non-inflammatory neurological diseases served as neurological control patients (NCTRL). IL-12 levels were correlated with age, age of disease onset, disease duration, MMSE score, and rate of dementia progression. Abeta42 and Total tau (tau(T)) levels in CSF were also measured. RESULTS: Patients with AD had significantly lower CSF IL-12 levels compared with NCTRL patients (p<0.001). Patients with FTD had also lower CSF IL-12 levels compared with NCTRL patients (p<0.05). Age, sex, disease duration and MMSE score did not affect IL-12 levels in any of the groups. In AD a significant positive correlation was noted between IL-12 levels and tau(T) levels (Rs=0.46, p=0.048). CONCLUSIONS: Our findings may suggest a reduced inflammatory reaction during the course of AD and FTD. A neurotrophic role of IL-12 and other proinflammatory cytokines cannot be excluded. 相似文献
134.
Eftihia Sbarouni Panagiota Georgiadou Antonis Analitis Antigoni Chaidaroglou Aikaterini Marathias Demitris Degiannis Vassilis Voudris 《International journal of cardiology》2013
Background
Biomarkers for monitoring progression and prognosis of thoracic aneurysm are of great interest. Homocysteine (Hcy) induces elastolysis in arterial media and may directly affect fibrillin-1 or collagen whereas lipoprotein (Lp) (a) inhibits elastolysis by reducing activation of matrix metallopeptidase-9.Methods
We studied 31 consecutive patients with acute aortic dissection (AAD) admitted for emergency surgery (group I, 60 ± 13 years old, 25 men), 30 consecutive patients with chronic aneurysms of the ascending aorta (group II, 67 ± 12 years old, 24 men) and 20 healthy controls (group III, 58 ± 15 years old, 14 men). We evaluated Hcy, folate, B12, Lp(a) and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism at baseline.Results
Hcy, folate and B12 differed significantly among the 3 studied groups (P = 0.016, P = 0.004 and P = 0.001, respectively). The levels of Hcy and B12 were significantly higher in group I compared to both groups II and III (P = 0.05 and P = 0.002, P < 0.001 and P = 0.017, respectively) and without significant differences between groups II and III (P = 0.083 and P = 0.124). Folate was significantly lower in group I compared to both groups II and III (P = 0.001 and P = 0.006, respectively) and without marked difference between groups II and III (P = 0.409). No significant difference was found in serum levels of Lp (a) (P = 0.074) or among the frequency of MTHFR C677T genotypes.Conclusions
Patients with AAD present with higher Hcy and lower folate compared to both chronic aneurysms and controls. 相似文献135.
Daskalakis A Kostopoulos S Spyridonos P Glotsos D Ravazoula P Kardari M Kalatzis I Cavouras D Nikiforidis G 《Computers in biology and medicine》2008,38(2):196-203
A multi-classifier diagnostic system was designed for distinguishing between benign and malignant thyroid nodules from routinely taken (FNA, H&E-stained) cytological images. To construct the multi-classifier system, several combination rules and different mixtures of ensemble classifier members, employing morphological and textural nuclear features, were comparatively evaluated. Experimental results illustrated that the classifier combination k-NN/PNN/Bayesian and the majority vote rule enhanced significantly classification accuracy (95.7%) as compared to best single classifier (PNN: 89.6%). The proposed system was designed with purpose to be utilized in daily clinical practice as a second opinion tool to support cytopathologists' decisions, when a definite diagnosis is difficult to be obtained. 相似文献
136.
137.
Critselis E Panagiotakos DB Machairas A Zampelas A Critselis AN Polychronopoulos E 《Nutrition and cancer》2011,63(7):1021-1028
Determination of the predictors of hypoproteinemia among cancer patients following extensive surgery may enhance their nutritional management and clinical outcome. This study evaluated the predictive factors of postoperative hypoproteinemia among cancer patients following extensive abdominal surgery. An age- and gender-matched case-control study (n = 115) was conducted among cancer patients undergoing extensive (cases; n = 81) and moderate (controls; n = 34) abdominal surgery. Case patients received total parenteral nutrition (TPN), including 3 units of fresh frozen plasma and 200 mL 5% human albumin solution, for 8 postoperative days (POD). Case patients had lower mean total serum protein (TSP) levels throughout POD 8 (F value = 13.81; P = 0.001). Despite TPN, cases had greatest mean (±SD) TSP percent change on POD 1 (-24.6% ± 13.0, vs. -12.6% ± 9.2; P < 0.0001) and did not regain preoperative levels (POD 8: -14.3% ± 12.5 vs. 6.9% ± 13.4; P = 0.006). The likelihood of hypoproteinemia in this group was greatest on POD 3 (OR = 30.57; 95% CI 5.44-171.83). Multivariate regression analyses indicated that the determinants of postoperative hypoproteinemia were age [Adjusted OR (AOR) = 1.04; 95% CI 1.00-1.08), preoperative TSP (AOR = 0.46; 95% CI 0.23-0.92), and extensive surgery (AOR = 2.65; 95% CI 1.01-6.95). Tailored nutritional support, regarding extent of surgery, preoperative TSP, and patient age are needed to deter the occurrence of postoperative hypoproteinemia and consequent adverse surgical outcome among cancer patients. 相似文献
138.
139.
140.