首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   5694篇
  免费   329篇
  国内免费   43篇
耳鼻咽喉   31篇
儿科学   168篇
妇产科学   124篇
基础医学   847篇
口腔科学   30篇
临床医学   500篇
内科学   1479篇
皮肤病学   112篇
神经病学   713篇
特种医学   110篇
外科学   406篇
综合类   10篇
一般理论   1篇
预防医学   292篇
眼科学   46篇
药学   446篇
中国医学   13篇
肿瘤学   738篇
  2024年   1篇
  2023年   37篇
  2022年   102篇
  2021年   140篇
  2020年   85篇
  2019年   115篇
  2018年   132篇
  2017年   113篇
  2016年   139篇
  2015年   155篇
  2014年   197篇
  2013年   259篇
  2012年   412篇
  2011年   434篇
  2010年   256篇
  2009年   232篇
  2008年   401篇
  2007年   386篇
  2006年   387篇
  2005年   387篇
  2004年   393篇
  2003年   322篇
  2002年   290篇
  2001年   47篇
  2000年   36篇
  1999年   57篇
  1998年   78篇
  1997年   65篇
  1996年   52篇
  1995年   51篇
  1994年   42篇
  1993年   38篇
  1992年   27篇
  1991年   30篇
  1990年   21篇
  1989年   20篇
  1988年   17篇
  1987年   16篇
  1986年   14篇
  1985年   15篇
  1984年   20篇
  1983年   15篇
  1982年   10篇
  1981年   4篇
  1980年   11篇
  1979年   2篇
  1977年   1篇
  1974年   1篇
  1966年   1篇
排序方式: 共有6066条查询结果,搜索用时 15 毫秒
71.
72.
The two essential requirements for pathologic specimens in the era of personalized therapies for non-small cell lung carcinoma (NSCLC) are accurate subtyping as adenocarcinoma (ADC) versus squamous cell carcinoma (SqCC) and suitability for EGFR molecular testing, as well as for testing of other oncogenes such as EML4-ALK and KRAS. Actually, the value of EGFR expressed in patients with NSCLC in predicting a benefit in terms of survival from treatment with an epidermal growth factor receptor targeted therapy is still in debate, while there is a convincing evidence on the predictive role of the EGFR mutational status with regard to the response to tyrosine kinase inhibitors (TKIs).This is a literature overview on the state-of-the-art of EGFR oncogenic mutation in NSCLC. It is designed to highlight the preclinical rationale driving the molecular footprint assessment, the progressive development of a specific pharmacological treatment and the best method to identify those NSCLC who would most likely benefit from treatment with EGFR-targeted therapy. This is supported by the belief that a rationale for the prioritization of specific regimens based on patient-tailored therapy could be closer than commonly expected.  相似文献   
73.
74.
75.
76.
77.
Residual high-on treatment platelet reactivity (HRPR) has been associated with a 2–9 fold increased risk of acute ischemic events in patients with acute coronary syndromes or coronary stenting. However, the mechanism of suboptimal platelet inhibition are still poorly understood. Aim of present study was to evaluate the role of the percentage of reticulated platelets on HRPR with ticagrelor. In patients treated with ASA (100–160 mg) and ticagrelor (90 mg twice a day) platelet reactivity and the reticulated platelets fraction (immature platelets fraction, IPF) were assessed at 30–90 days after acute coronary syndrome. Aggregation was assessed by multiple-electrode aggregometry. HRPR was defined as ADP test >417 AU*min. Our population is represented by 190 patients, divided according to tertiles values of IPF (<2.5; 2.5–3.99; ≥4 %). Higher IPF was associated to a larger platelet volume and lower platelets count (p < 0.001), and inversely related with a history of previous coronary revascularization (p = 0.03). Twenty-one out of 190 (11.0 %) patients displayed HRPR. No difference in the levels of circulating IPF was found in patients with or without HRPR (p = 0.25), with no correlation between the rate of reticulated platelets and platelet reactivity at ADP test (r = ?0.084, p = 0.26). In fact no association was observed between high levels of IPF and the occurrence of HRPR (adjusted OR[95 % CI] = 0.69[0.34–1,37], p = 0.28), even after correction for baseline differences. In patients treated with ticagrelor, the levels of circulating reticulated platelets assessed at 30–90 days post-ACS are not associated with platelet reactivity or the occurrence of HRPR.  相似文献   
78.
Objective—To assess prevalence and type of non-atherosclerotic coronary artery disease in young people (≤35 years) who died suddenly.

Design—A necropsy study of 150 consecutive cases of sudden death (that is, within 6 h of the onset of symptoms).

Results—Death was attributed to coronary artery disease in 48 cases: in 16 (33%) of them the disease was non-atherosclerotic. Twelve subjects (eight males and four females, age range 2–35 years, mean 24·2) had congenital anomalies: a deep intramyocardial course in six, origin from the wrong sinus in three, and ostial obstructions in three. Sudden death was the first manifestation of disease in six cases. The other six had a history of palpitation or syncope or both. An electrocardiogram was available in five cases and showed ventricular arrhythmias in four; none had angina pectoris. Stress testing was available in two cases: neither showed any effort-dependent ST-T abnormalities. In six cases sudden death was related to physical exercise. Acquired non-atherosclerotic coronary artery disease was found in four cases: spontaneous coronary dissection in three previously symptom free patients and Kawasaki coronary arteritis in one child who had had acute myocardial infarction.

Conclusion—One third of the cases of fatal coronary artery disease were non-atherosclerotic with coronary artery anomalies being the most frequent form. Coronary artery anomalies should be suspected in young patients who have symptoms of ventricular arrhythmias without any overt signs and symptoms of ischaemia.

  相似文献   
79.
Based on quantitative analysis of red cell membrane proteins, hereditary spherocytosis (HS) can be divided into two main groups including isolated or ankyrin combined spectrin deficiency and band 3 reduction. Protein methyl esterification catalysed by protein carboxyl methyltransferase (PCMT type II; EC 2.1.1.77) is a post-biosynthetic modification which is involved in the metabolism of damaged membrane proteins. We utilized the evaluation of erythrocyte membrane protein methyl esterification as a marker of cytoskeletal disarray in seven HS subjects with spectrin reduction and in seven patients with HS due to band 3 deficiency. Our results support the notion that band 3 deficient erythrocytes are not affected by an extensive cytoskeletal derangement. On the contrary, we found a remarkable increase of membrane methylation in the unsplenectomized, spectrin-deficient, HS patients, suggesting a striking membrane skeleton disarray. This phenomenon was not observed in the spectrin-deficient red cells of splenectomized patients. Therefore in spectrin deficient erythrocytes the induction of cytoskeletal damage, specifically recognized by PCMT type II, could be one of the splenic steps producing conditioned spherocytes.  相似文献   
80.
Raynaud’s phenomenon in undifferentiated connective tissue disease (UCTD)   总被引:1,自引:0,他引:1  
The aim of this study was to ascertain which clinical and immunological factors are associated with Raynauds phenomenon (RP) in patients with undifferentiated connective tissue disease (UCTD) and to investigate microvascular involvement. A total of 78 patients were evaluated. They all showed symptoms suggestive of a connective tissue disorder (CTD), but did not fulfil the criteria for any of the defined CTDs. They all had a disease duration of at least 1 year. Nailfold capillaroscopy (NC) was performed using a computerised videomicroscope. We diagnosed RP in 52.5% of our patients. Patients with RP showed a higher occurrence of oesophageal dysmotility (p=0.001) and anti-ribonucleoprotein (RNP) antibodies (p=0.004) than those without RP. The distinguishing capillaroscopic characteristics of UCTD patients with RP were widened and irregularly enlarged loops (75 and 55%, respectively), giant capillaries (35%), and less than two haemorrhages per finger (40%). The combination of features indicative of a slow scleroderma pattern was present in 18 of 40 patients with UCTD and RP (p=0.0003). Only 3 of the original 78 patients (3.8%) developed a definite CTD. In none of our patients did we observe avascular areas or changes from the original capillaroscopic pattern during follow-up examination. Our study indicates that patients with UCTD would seem to have a benign form of RP, since they show the absence of cutaneous complications, the existence of a mild microvascular damage and a stable nailfold capillary pattern. Further examinations of these patients will be required in order to confirm our findings.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号