全文获取类型
收费全文 | 22136篇 |
免费 | 2188篇 |
国内免费 | 1299篇 |
专业分类
耳鼻咽喉 | 198篇 |
儿科学 | 283篇 |
妇产科学 | 419篇 |
基础医学 | 2024篇 |
口腔科学 | 437篇 |
临床医学 | 2972篇 |
内科学 | 2936篇 |
皮肤病学 | 260篇 |
神经病学 | 975篇 |
特种医学 | 691篇 |
外国民族医学 | 8篇 |
外科学 | 1458篇 |
综合类 | 4474篇 |
现状与发展 | 10篇 |
一般理论 | 1篇 |
预防医学 | 2049篇 |
眼科学 | 560篇 |
药学 | 2794篇 |
16篇 | |
中国医学 | 1722篇 |
肿瘤学 | 1336篇 |
出版年
2024年 | 74篇 |
2023年 | 320篇 |
2022年 | 797篇 |
2021年 | 1025篇 |
2020年 | 824篇 |
2019年 | 599篇 |
2018年 | 641篇 |
2017年 | 689篇 |
2016年 | 621篇 |
2015年 | 976篇 |
2014年 | 1236篇 |
2013年 | 1287篇 |
2012年 | 1833篇 |
2011年 | 1920篇 |
2010年 | 1474篇 |
2009年 | 1247篇 |
2008年 | 1477篇 |
2007年 | 1376篇 |
2006年 | 1317篇 |
2005年 | 1113篇 |
2004年 | 807篇 |
2003年 | 717篇 |
2002年 | 667篇 |
2001年 | 500篇 |
2000年 | 413篇 |
1999年 | 317篇 |
1998年 | 185篇 |
1997年 | 204篇 |
1996年 | 142篇 |
1995年 | 143篇 |
1994年 | 106篇 |
1993年 | 71篇 |
1992年 | 96篇 |
1991年 | 83篇 |
1990年 | 64篇 |
1989年 | 56篇 |
1988年 | 47篇 |
1987年 | 37篇 |
1986年 | 35篇 |
1985年 | 17篇 |
1984年 | 12篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 7篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1972年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
目的:克隆人肠道病毒71型(EV71)及柯萨奇病毒A组16型(CA16)的VP1蛋白编码基因,构建相应真核表达质粒在体外进行重组表达,检测其细胞内定位,为EV71及CA16的疫苗研究提供基础。方法:通过PCR扩增分别获取EV71及CA16的VP1编码序列,插入pcFlag载体,分别构建EV71及CA16 VP1与FLAG标签融合的真核表达质粒;瞬时转染人胚肾293T细胞及横纹肌肉瘤RD细胞,Western blot法检测融合蛋白的表达,免疫荧光检测融合蛋白的细胞内定位情况。结果:测序表明两种来源VP1蛋白的重组表达质粒构建正确;分别转染两种不同的细胞后,均可通过Western blot检测到相应蛋白表达;免疫荧光检测显示两种毒株的VP1均表达在细胞质中。结论:外源融合表达EV71或CA16 VP1蛋白的真核表达质粒构建成功;所构建质粒分别转染细胞后,均可在细胞质内检测到VP1融合蛋白的表达。 相似文献
992.
Fei Xu Ming‐Liang Ye Yu‐Peng Zhang Wen‐Jie Li Meng‐Ting Li Hai‐Zhou Wang Xiao Qiu Yan Xu Jin‐Wen Yin Qian Hu Wan‐Hui Wei Ying Chang Lan Liu Qiu Zhao 《Cancer science》2020,111(5):1528-1541
Resistance to chemotherapy is a major challenge for the treatment of patients with colorectal cancer (CRC). Previous studies have found that microRNAs (miRNAs) play key roles in drug resistance; however, the role of miRNA‐373‐3p (miR‐375‐3p) in CRC remains unclear. The current study aimed to explore the potential function of miR‐375‐3p in 5‐fluorouracil (5‐FU) resistance. MicroRNA‐375‐3p was found to be widely downregulated in human CRC cell lines and tissues and to promote the sensitivity of CRC cells to 5‐FU by inducing colon cancer cell apoptosis and cycle arrest and by inhibiting cell growth, migration, and invasion in vitro. Thymidylate synthase (TYMS) was found to be a direct target of miR‐375‐3p, and TYMS knockdown exerted similar effects as miR‐375‐3p overexpression on the CRC cellular response to 5‐FU. Lipid‐coated calcium carbonate nanoparticles (NPs) were designed to cotransport 5‐FU and miR‐375‐3p into cells efficiently and rapidly and to release the drugs in a weakly acidic tumor microenvironment. The therapeutic effect of combined miR‐375 + 5‐FU/NPs was significantly higher than that of the individual treatments in mouse s.c. xenografts derived from HCT116 cells. Our results suggest that restoring miR‐375‐3p levels could be a future novel therapeutic strategy to enhance chemosensitivity to 5‐FU. 相似文献
993.
目的为提高国家农村妇女乳腺癌筛查项目效果,第2个周期(2012-2014年)筛查模式调整为基于超声的乳腺癌筛查,本研究通过对2014年度农村妇女乳腺癌筛查数据进行分析,了解基于超声的乳腺癌筛查模式的质量和效果,为完善筛查流程、提高筛查质量和管理水平提供依据。方法采用基于超声的乳腺癌筛查模式为全国35~64岁农村户籍女性进行群体性乳腺癌筛查:先为符合条件的农村女性进行乳腺临床检查联合乳腺超声检查,超声BI-RADS 0、4、5级者进行乳腺X射线检查(mammography,MG),X射线BI-RADS 0、4、5级者进行组织病理检查,乳腺超声、X射线BI-RADS 1、2、3级者进行1年随访。检查数据以统计报表和个案表(筛出乳腺癌患者)形式录入《国家妇幼重大公共卫生项目信息直报系统》。分东、中、西部地区计算乳腺癌召回率、活检率、活检阳性预测值、检出率、早诊率、原位癌比例、早期癌比例、漏检率、假阳性率等主要评估指标;使用χ^2检验对地区间指标结果进行比较。结果2014年为30个省(市、区)697个项目县共1373524名35~64岁农村女性进行了乳腺癌筛查。检出乳腺癌1190例,检出率为0.87‰;东、中、西部地区检出乳腺癌例数分别为404、375和411例,检出率分别为0.90‰、0.86‰和0.84‰,地区间检出率差异无统计学意义,χ^2=1.215,P>0.05。共检出早期乳腺癌1014例,早诊率为85.21%;东、中、西部地区检出早期乳腺癌例数分别为353、323和338例,早诊率分别为87.38%、86.13%和82.24%,地区间早诊率差异无统计学意义,χ^2=4.638,P>0.05。检出原位癌82例,原位癌比例为6.89%;东、中、西部地区分别检出原位癌39、23和20例,原位癌比例分别为9.65%、6.13%和4.87%,原位癌比例地区间差异有统计学意义,χ^2=7.767,P<0.05。检出早期癌(0+Ⅰ期)387例,早期癌比例为32.52%;东、中、西部地区早期癌例数分别为159、115和113例,早期癌比例分别为39.36%、30.67%和27.49%,地区间差异有统计学意义,χ^2=13.922,P<0.01。MG复筛人数为33129人,召回率为2.41%;东、中、西部地区MG复筛人数分别为12827、11616和8686人,召回率分别为2.87%、2.67%和1.77%,地区间差异有统计学意义,χ^2=1386,P<0.01。3088人接受活检,活检率为0.22%;东、中、西部地区接受活检人数分别为1106、1006和976人,活检率分别为0.25%、0.23%和0.20%,地区间差异有统计学意义,χ^2=25.910,P<0.01。超声初筛漏检率为7.23%,其中BI-RADS 3级漏检率为6.89%;MG复筛BI-RADS 3级漏检率3.99%;仅超声检出乳腺癌比例为5.58%。结论2014年中国农村妇女乳腺癌检查项目检出和早诊情况符合相关质控要求,说明基于超声的乳腺癌筛查在中国农村地区可行且有效。但本筛查流程的漏检率仍较高,需进行流程优化。应加强MG和活检设备配置及技术培训,以提高乳腺癌筛查服务能力,从而进一步提高检出率和早诊率。 相似文献
994.
Jia Huang Huasheng Yao Yexing Li Mengyi Dong Chu Han Lan He Xiaomei Huang Ting Xia Zongjian Yi Huihui Wang Yuan Zhang Jian He Changhong Liang Zaiyi Liu 《中国癌症研究》2021,33(1):69-78
Objectives:To develop and validate a radiomics nomogram for preoperative prediction of tumor histologic grade in gastric adenocarcinoma(GA).Methods:This retrospective study enrolled 592 patients with clinicopathologically confirmed GA(low-grade:n=154;high-grade:n=438)from January 2008 to March 2018 who were divided into training(n=450)and validation(n=142)sets according to the time of computed tomography(CT)examination.Radiomic features were extracted from the portal venous phase CT images.The Mann-Whitney U test and the least absolute shrinkage and selection operator(LASSO)regression model were used for feature selection,data dimension reduction and radiomics signature construction.Multivariable logistic regression analysis was applied to develop the prediction model.The radiomics signature and independent clinicopathologic risk factors were incorporated and presented as a radiomics nomogram.The performance of the nomogram was assessed with respect to its calibration and discrimination.Results:A radiomics signature containing 12 selected features was significantly associated with the histologic grade of GA(P<0.001 for both training and validation sets).A nomogram including the radiomics signature and tumor location as predictors was developed.The model showed both good calibration and good discrimination,in which C-index in the training set,0.752[95%confidence interval(95%CI):0.701-0.803];C-index in the validation set,0.793(95%CI:0.711-0.874).Conclusions:This study developed a radiomics nomogram that incorporates tumor location and radiomics signatures,which can be useful in facilitating preoperative individualized prediction of histologic grade of GA. 相似文献
995.
Rationale:Hemangioblastomas (HGBMs) are very rare, and the cerebellum is usually the most common site of occurrence. HGBMs with ring-enhanced walls are often misdiagnosed as metastases, abscesses, glioblastomas, tuberculomas, and demyelinating diseases. Thus, we present a rare case of HGBM masquerading as a ring-enhancing lesion in the cerebellum.Patient concerns:We present a 33-year-old female who was admitted to our department because of headaches, unstable walking, and visual loss in both eyes. Cranial nerve examination revealed deficits in cranial nerve II.Diagnosis:Magnetic resonance imaging revealed 2 cystic lesions in the cerebellum, with irregular ring-enhanced cyst walls composed of smaller nodular parts. Immunohistochemical staining of resected specimens established HGBM.Interventions:The lesions were completely resected using a right retrosigmoid approach.Outcomes:Two years of follow-up revealed no recurrence of her symptoms or tumor. She is currently well and performs her daily duties.Lessons:HGBMs with enhanced cysts are often misdiagnosed by radiology because of their ring-enhanced nature. Computed tomography angiography may be the best modality for differentiating cerebellar HGBM from other ring-enhancing lesions. Surgery is the gold standard of treatment for these lesions. 相似文献
996.
目的了解空降兵在跳伞训练前期的心理健康状况,为做好心理咨询与卫生保健提供依据。方法运用SCL-90症状自评量表,对607名空降兵在跳伞训练前期进行调查。结果除敌对性与精神病性两因子无差异外,其余7个因子及总分和阳性项目均分均高于中国人常模;与军人常模相比,躯体化、抑郁、偏执3个因子差异无统计学意义(P>0.05),人际关系、精神病性、敌对性3个因子低于军人常模;其余3个因子及总分和阳性项目均分均高于军人常模。结论高度重视空降兵跳伞训练中的心理健康问题,增强其正性情感体验、心理防护能力和应急反应能力,提高部队战斗力。 相似文献
997.
Shenglei Shu Lan Cheng Jing Wang Chuansheng Zheng 《Interactive Cardiovascular and Thoracic Surgery》2022,34(2):336
We report a case of a 58-year-old female with Stanford type A aortic dissection sparring the donor aorta 2 years after heart transplantation. Lumbar spine magnetic resonance examination for low back pain discovered the aortic dissection which was confirmed by following computed tomography angiography. The patient received surgical treatment including total arc replacement and thoracic aortic endovascular repair and recovered well. 相似文献
998.
目的 探究瑞戈非尼联合XELOX化疗方案治疗结直肠癌疗效及对血管新生指标、肿瘤免疫逃逸的影响。方法 选取2018年1月—2022年1月泸州市人民医院收治的80例结直肠癌患者,随机分为对照组和治疗组,每组各40例。对照组采用XELOX方案治疗,第1天静脉滴注注射用奥沙利铂130 mg/m2;第1~14天,口服卡培他滨片1 000 mg/m2,2次/d;21 d为1个周期。治疗组在对照组基础上口服瑞戈非尼片,160 mg/次,1次/d,用药21 d停用7 d,28 d为1个周期。病情进展或无法耐受停止用药。观察两组患者疾病控制率,比较治疗前后两组患者血清癌胚抗原(CEA)、大肠特异性抗原-2(CCSA-2)、糖类抗原19-9(CA19-9)、血管内皮生长因子(VEGF)、转化生长因子-β(TGF-β)、程序性死亡分子-1(PD-1)、程序性死亡分子配体-1(PD-L1)水平,及生存质量。结果 治疗后,治疗组疾病控制率(77.50%)较对照组(55.00%)明显升高(P<0.05)。治疗后,两组CA19-9、CCSA-2、CEA、TGF-β、... 相似文献
999.
1000.