全文获取类型
收费全文 | 291篇 |
免费 | 15篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 7篇 |
妇产科学 | 8篇 |
基础医学 | 37篇 |
口腔科学 | 11篇 |
临床医学 | 31篇 |
内科学 | 37篇 |
皮肤病学 | 2篇 |
神经病学 | 2篇 |
特种医学 | 45篇 |
外科学 | 26篇 |
综合类 | 66篇 |
预防医学 | 19篇 |
药学 | 3篇 |
中国医学 | 1篇 |
肿瘤学 | 16篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 7篇 |
2014年 | 7篇 |
2013年 | 12篇 |
2012年 | 7篇 |
2011年 | 4篇 |
2010年 | 20篇 |
2009年 | 19篇 |
2008年 | 19篇 |
2007年 | 23篇 |
2006年 | 13篇 |
2005年 | 8篇 |
2004年 | 9篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 14篇 |
1998年 | 22篇 |
1997年 | 15篇 |
1996年 | 15篇 |
1995年 | 5篇 |
1994年 | 10篇 |
1993年 | 8篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 13篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有312条查询结果,搜索用时 15 毫秒
51.
52.
Anna-Kaisa Eerola Henni Ruokolainen Ylermi Soini Hannu Raunio Paavo PÄÄKKÖ 《Pathology oncology research : POR》1999,5(3):179-186
In order to test the hypothesis that increased apoptotic activity is connected with neuroendocrine differentiation and low
differentiation degree in large cell carcinoma (LCLC) and is regulated by bcl-2 family proteins, we analysed the extent of
apoptosis and tumor necrosis and their relation to the expression of bcl-2, bax, bak and mcl-1 in 35 LCLCs, of which 20 were
classified as large cell neuroendocrine lung carcinomas (LCNEC) and 15 as large cell non-neuroendocrine lung carcinomas (LCNNEC).
The extent of apoptosis was determined by detecting and counting the relative and absolute numbers of apoptotic cells and
bodies using in situ 3′-end labelling of the apoptotic DNA. The extent and intensity of expression of the bcl-2, bax, bak
and mcl-1 proteins were studied by immunohistochemistry. Also the relative volume density of necrosis was evaluated and correlated
with the other parameters. Finally, all the parameters were evaluated as prognostic markers and correlated with data on the
survival of the patients. Relatively high apoptotic indices were seen in both tumor types (average for both 2.53%, range 0.09–27.01%).
Significantly higher bcl-2 and bak indices were detected more often in LCNECs than in LCNNECs. Immunohistochemically detected
bax, bcl-2 and bak expression was independent of apoptotic index in both tumor types, while there was a statistically significant
positive association between mcl-1 expression and apoptotic index in LCNNEC but not in LCNEC. There was a statistically significant
association between high apoptotic index and shortened survival in LCLC. However, no association was found between tumor stage
and apoptosis. The patients with LCNEC and low bcl-2 protein expression had a significantly shorter survival time than those
with high bcl-2 indices. There was also a clear association between shortened survival and necrotic LCNNEC. LCLCs show relatively
high apoptotic activity, which is associated with shortened survival. The expression of bcl-2, bak and mcl-1 is associated
with neuroendocrine differentiation in LCLC. Finally, our results support some previous reports suggesting that bcl-2 expression
in combination with some other markers involved in apoptosis and/or proliferation may be of prognostic value in cases of lung
carcinoma with neuroendocrine differentiation. 179-186, 1999) 相似文献
53.
Background
Migrants from countries with a high-burden of tuberculosis (TB) are at a particular risk of contracting and developing the disease. In Sweden, new immigrants are routinely offered screening for the disease, yet very little is known about their beliefs about the disease which may affect healthcare-seeking behaviours. In this study we assessed recent immigrant students' knowledge of, and attitudes towards TB, and their relationship with the screening process. 相似文献54.
DNA amplification by Polymerase Chain Reaction (PCR) of a repetitive sequence specific for Mycobacterium tuberculosis, from clinical samples of extra pulmonary origin were evaluated. The 123 base pair fragment of the insertion element IS 6110 in Mycobacterium tuberculosis was amplified. A total of 50 samples were analysed by PCR and compared with culture on Lowenstein-Jensen medium (LJ) and the clinical findings of the patient. Out of the total 26 samples were positive by PCR, while only seven grew the bacilli in culture. 24 samples were negative by PCR and culture. All the seven samples that grew the bacilli on culture were positive by PCR. In remaining 19 cases that were positive by PCR but did not grow the bacilli clinical features, radiological findings and Mantoux test were strongly suggestive of M. tuberculosis. All the amplification negative cases had no positive evidence of tuberculosis but were being followed up. When correlated with culture and clinical history the sensitivity of PCR for the diagnosis of active tuberculosis was 100%. However, the specifity was only 55.8% as culture on LJ (Gold Standard) was positive in only 7 samples out of 26 samples that were positive by PCR.KEY WORDS: DNA Amplification, IS 6110, Mycobacterium tuberculosis. 相似文献
55.
自美国国家骨髓库(NMDP)开展第一例无关供者移植以来,至今已有20年.NMDP目前的库容量已逾700万,已为6大洲提供了30 000多份无关供者造血干细胞.这一辉煌成就是美国国家骨髓库600多名工作人员共同努力的结果,同时也得益于广泛的国际合作,包括171个移植中心,73个供者中心,24个脐血库,97个骨髓采集中心,91个血液净化中心,26个HLA分型实验室和26个合作供者登记处.本文回顾了美国国家骨髓库的历史,阐述了20年来移植病人、移植物来源和预处理方案几方面的主要变化趋势. 相似文献
56.
Percutaneous cholecystostomy: an alternative to surgical cholecystostomy for acute cholecystitis? 总被引:1,自引:0,他引:1
Emergency percutaneous cholecystostomy was successfully performed in 39 of 40 attempted procedures in 37 hospitalized patients with possible acute cholecystitis. All cholecystostomies were performed with ultrasound guidance and preferentially with the transhepatic route, and all but four were performed at the patient's bedside. The patients had been hospitalized an average of 27 days before the procedure. Twenty-two of the 37 patients (59%) eventually died during hospitalization because of other medical or surgical problems. Only minor complications related to percutaneous cholecystostomy placement occurred in this series: catheter dislodgment without sequelae (n = 2) and significant abdominal pain (n = 2). Technical problems included guide-wire buckling during catheter insertion (n = 1) and failed attempted cholecystostomy (n = 1). Percutaneous cholecystostomy is a safe alternative to surgical cholecystostomy in the treatment of patients suspected of having acute cholecystitis. 相似文献
57.
Background/aim
Parents whose first infant had birth defects may worry about a new pregnancy. Our aim was to study pregnancy outcomes among non-malformed second siblings in families where the first birth had a major birth defect.Methods
Data were from the Medical Birth Registry of Norway from 1967 to 2004. Births were linked to their mothers through the unique national identification numbers, providing sibship files with the mother as the observation unit. The study was based on 538,669 singleton first and second full siblings. Families were classified as affected families if the first infant had a major birth defect. Pregnancy outcomes for non-malformed second siblings following affected first births were compared with second siblings in families without malformed infants. Subgroup analyses were done for families where first infants had neural tube defects, cleft lip with or without cleft palate, abdominal wall defects, limb reduction defects, pes equinovarus and congenital dysplasia of the hip.Results
Second siblings in affected families did not differ from those in unaffected families in risk of perinatal death, small for gestational age, preterm birth, placental abruption or preeclampsia. Second siblings following an infant with limb reduction defects had a higher risk of breech presentation than second siblings in unaffected families, also when stratifying on previous siblings in vertex presentation (stratified OR 2.20 [95% C.I. 1.17-4.15]).Conclusion
Parents who proceed to a new pregnancy after a first birth with birth defects may be reassured that, given no recurring defects, there is in general no increased risk of adverse pregnancy outcomes. 相似文献58.
RIITTA KAARTEENAHO RAIJA SORMUNEN PAAVO PÄÄKKÖ 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2010,118(2):91-100
Kaarteenaho R, Sormunen R, Pääkkö P. Variable expression of tenascin‐C, osteopontin and fibronectin in inflammatory myofibroblastic tumour of the lung. APMIS 2010; 118: 91–100. The aim of this study was to analyse the expression of tenascin‐C, osteopontin and fibronectin in inflammatory myofibroblastic tumour of the lung, which is a rare tumour of unknown aetiology. Nine patients with an inflammatory myofibroblastic tumour of lung were studied by immunohistochemistry for the presence of tenascin‐C, osteopontin, fibronectin and alpha‐smooth muscle actin, which is a common marker for myofibroblasts. The ultrastructure of myofibroblasts was confirmed by transmission electron microscopy. The expression of tenascin‐C, osteopontin, fibronectin and alpha‐smooth muscle actin was also studied by immunoelectron microscopy. All cases displayed all of the studied extracellular matrix proteins and also alpha‐smooth muscle actin‐positive spindle‐shaped fibroblastic cells that were undoubtedly myofibroblasts. The immunoelectron microscopic studies demonstrated labelling for alpha‐smooth muscle actin in intracellular filament bundles within myofibroblasts, for fibronectin in the extracellular filaments of the fibronexus and for tenascin‐C extracellularly often adjacent to myofibroblasts. Labels for osteopontin were observed within myofibroblasts and plasma cells. These results demonstrate that tenascin‐C, osteopontin and fibronectin were expressed in all three kinds of subtypes of inflammatory myofibroblastic tumours of the lung and further, variable amounts of myofibroblasts could be observed by light and transmission electron microscopy as well as by immunoelectron microscopic techniques. 相似文献
59.
60.
Full-frame transform compression of CT and MR images 总被引:3,自引:0,他引:3