全文获取类型
收费全文 | 443篇 |
免费 | 5篇 |
国内免费 | 6篇 |
专业分类
教育 | 281篇 |
科学研究 | 117篇 |
体育 | 25篇 |
综合类 | 13篇 |
文化理论 | 1篇 |
信息传播 | 17篇 |
出版年
2022年 | 13篇 |
2021年 | 29篇 |
2020年 | 7篇 |
2019年 | 6篇 |
2018年 | 3篇 |
2017年 | 6篇 |
2016年 | 11篇 |
2015年 | 16篇 |
2014年 | 31篇 |
2013年 | 33篇 |
2012年 | 28篇 |
2011年 | 21篇 |
2010年 | 20篇 |
2009年 | 20篇 |
2008年 | 21篇 |
2007年 | 32篇 |
2006年 | 36篇 |
2005年 | 23篇 |
2004年 | 26篇 |
2003年 | 9篇 |
2002年 | 14篇 |
2001年 | 11篇 |
2000年 | 13篇 |
1999年 | 7篇 |
1998年 | 6篇 |
1997年 | 5篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1992年 | 3篇 |
排序方式: 共有454条查询结果,搜索用时 15 毫秒
51.
Chen L Tian H Chen J He ZG Tao SF Lokesh G Peng SY 《Journal of Zhejiang University. Science. B》2005,6(1):38-42
Objective: To observe the clinicopathological characteristics of gastric stump cancer (GSC) and evaluate the benefits of radical surgery of GSC. Methods: The clinicopathological characteristics and postoperative survival time of 37 GSC patients who underwent surgery were investigated retrospectively. The survival time was compared according to the type of surgical pTMN stage. Survival curves were traced by using Kaplan-Meier methods. Results: Most GSC (32/37) was detected in patients who had received Billroth Ⅱ reconstruction after partial gastrectomy for benign gastric disease. The lesser curvature side and the suture line of anastomosis were the most frequent sites where GSC occurred (27/37). Differentiated adenocarcinoma was the dominant histopathological type (24/37). The postoperative 5-year survival rate of early stage GSC patients (n=9) was significantly higher than advanced stage GSC (n=12) (55.6% vs 16.5%, xL2=1 1.48, P<0.01). Five-year survival rate of 21 GSC patients with radical resection were 75% (3/4) for stage Ⅰ, 60% (3/5) for stage Ⅱ, 14.2% (1/7) for stage Ⅲ, and 0% (0/5) for stage Ⅳ respectively.The median survival time of 21 GSC patients who underwent radical resection was longer than those undergoing palliative operation (43.0m vs 13.0m, xL2=36.31, P<0.01), the median survival time of stage Ⅳ patients with radical resection was 23.8months. Conclusions: Without remote metastasis, radical resection for GSC is possible, and is an effective way to improve the prognosis of GSC. Even in stage Ⅳ GSC, radical resection can still prolong the survival time. It is necessary for the patients with benign gastric diseases who received partial gastrectomy to carry out the endoscopy follow-up, especially in patients with Billroth Ⅱ reconstruction procedure at 15-20 years. 相似文献
52.
Study on interleukin-18 gene transfer into human breast cancer cells to prevent tumorigenicity 总被引:1,自引:0,他引:1
INTRODUCTIONInterleukin-18(IL-18),originallydescribedasinterferon(IFN)-g-inducingfactor,isan18.3-kDaproinflammatorycytokineproducedbyactivatedmacrophagesanddendriticcells,andplaysanim-portantroleintheTh1response,primarilybasedonitsabilitytoinduceIFN-gproductioninTcellsandNKcells.IL-18inducesproliferationofactivatedTcells,secretionofseveralcytokines,andpartici-patesinbothinnateandacquiredimmunity.TheroleofIL-18inantitumorimmunitywassuggestedinmanystudies.Genetransferofcytokinesisani… 相似文献
53.
54.
目的:探讨大肠癌、乳腺癌中生存素的临床意义。方法:收集大肠癌68例,乳腺癌69例,利用SABC免疫组织化学方法,检测Survivin表达状况。结果:大肠癌和乳腺癌中Survivin阳性率分别为63.24%和42.03%,Survivin在大肠癌低分化组和深浸润组阳性率明显高于浅浸润和高分化组;在浸润型乳腺癌组和有淋巴结转移组Survivin阳性率明显增高。结论:Survivin表达与癌组织生物学特性有关;检测癌组织中Sur-vivin表达可以提示预后及指导靶向治疗方案的制定。 相似文献
55.
目的:探讨肺内孤立性结节(Solitary pulmonary nodule.SPN)的HRCT特征与良恶性病变之间的关系。方法:对66例肺内孤立性结节病灶进行螺旋HRCT增强扫描,观察结节增强的程度、周围的血管以及瘤肺界面的特征,来判定结节的良恶性。结果:病理证实50例周围型肺癌(Peripheral lung cancer,PLC).16例良性结节。①PLC血供较良性结节丰富;②动脉期结节强化程度增强明显,平衡期达到峰值为PLC,PLC瘤肺界面清晰伴有深分叶,良性结节周围模糊。结论:PLC血供丰富、增强快,平衡期达最高,瘤肺界面清晰;良性结节增强慢,与肺界面关系模糊。 相似文献
56.
57.
支气管肺癌并发肺脓肿48例临床分析 总被引:4,自引:0,他引:4
目的:探讨支气管肺癌并发肺脓肿的诊断.方法:回顾分析48例支气管肺癌并发性肺脓肿的临床、放射、纤维气管镜检查及开胸肺活检方面的资料.结果:肺癌合并肺脓肿时思维要开阔,纤支镜或开胸肺活检可协助肺癌确诊.结论:纤支镜对肺脓肿、肺癌明确诊断帮助很大,可减少误诊机会. 相似文献
58.
59.
INTRODUCTION Helicobacter pylori (H.pylori) was grouped as a class I carcinogen by the International Agency for Research on Cancer in 1994. A direct relation be-tween H.pylori infection and gastric carcinogenesis was demonstrated in 1998 in an experimental animal model (Watanabe et al., 1998). However, the role of H.pylori in human gastric carcinogenesis is sup-ported almost exclusively by epidemiological data and prospective histopathological studies. So far the mechanism of H.pylor… 相似文献
60.
关于膳食纤维抗大肠癌的研究 总被引:5,自引:0,他引:5
科学家和医生们对食物纤维与结肠癌风险之间的关系,已进行了20多年的研究,取得了许多研究成果,但也存在着一些争论。本文介绍了国外对此问题的研究方向、研究方法及其进展情况。 相似文献