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   100554篇
  免费   10201篇
  国内免费   4932篇
耳鼻咽喉   2420篇
儿科学   591篇
妇产科学   1816篇
基础医学   11920篇
口腔科学   3425篇
临床医学   7596篇
内科学   12641篇
皮肤病学   2037篇
神经病学   529篇
特种医学   4457篇
外国民族医学   130篇
外科学   14960篇
综合类   17887篇
现状与发展   23篇
预防医学   2289篇
眼科学   584篇
药学   5099篇
  24篇
中国医学   1321篇
肿瘤学   25938篇
  2024年   128篇
  2023年   1445篇
  2022年   2255篇
  2021年   4035篇
  2020年   3583篇
  2019年   3369篇
  2018年   3186篇
  2017年   3615篇
  2016年   4096篇
  2015年   4613篇
  2014年   6709篇
  2013年   5951篇
  2012年   6014篇
  2011年   6506篇
  2010年   5191篇
  2009年   5098篇
  2008年   5324篇
  2007年   5597篇
  2006年   5230篇
  2005年   4666篇
  2004年   3712篇
  2003年   3286篇
  2002年   2805篇
  2001年   2661篇
  2000年   2291篇
  1999年   1842篇
  1998年   1662篇
  1997年   1505篇
  1996年   1345篇
  1995年   1170篇
  1994年   1050篇
  1993年   763篇
  1992年   670篇
  1991年   590篇
  1990年   495篇
  1989年   438篇
  1988年   407篇
  1987年   334篇
  1986年   294篇
  1985年   316篇
  1984年   251篇
  1983年   176篇
  1982年   212篇
  1981年   187篇
  1980年   172篇
  1979年   125篇
  1978年   103篇
  1977年   80篇
  1976年   58篇
  1975年   29篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.

Background

Clear cell renal cell carcinoma (ccRCC) is known to occur across the adult lifetime traversing the spectrum of age-related organismal changes. Little is known as to how the aging process may affect the course of renal cell carcinoma (RCC) and the repertoire of genes involved.

Methods

Using The Cancer Genome Atlas (n?=?436) and Cancer Genomics of the Kidney (n?=?89) datasets, we applied regression analysis to examine associations between patient age and gene expression profiles in ccRCC tumors and normal kidney tissues. Pathway enrichment analysis was performed to identify cellular process that is affected by aging in ccRCC. Moreover, connectivity mapping analysis was used to predict age-dependent response to drug treatments.

Results

Our analysis revealed different age-dependent gene expression spectra in ccRCC and normal kidney tissues. These findings were significant and independently reproducible in both datasets examined. Age up-regulated genes, showing higher expression in older patients, were significantly enriched (false discovery rate <0.05) in normal tissues for pathways associated with immune response and extracellular matrix organization, whereas age up-regulated genes in tumors were enriched for metabolism and oxidation pathways. Strikingly, age down-regulated genes in normal cells were also enriched for metabolism and oxidation, while those in tumors were enriched for extracellular matrix organization. Further in silico analysis of potential drug targets predicted preferential efficacy of Phosphoinositide 3-kinase inhibitor or immunotherapy in association with age.

Conclusion

We report on previously unrecognized associations between age and molecular underpinnings of RCC, including age-associated expression of genes implicated in RCC development or treatment.  相似文献   
102.
103.
IntroductionMuch controversy exists over whether to perform lateral neck dissection (LND) on patients with papillary thyroid carcinoma (PTC). This study aimed to build predictive nomograms that could individually estimate lateral neck metastasis (LNM) risk and help determine follow up intensity.Patients and methodsUnifocal PTC patients who underwent LND between April 2012 and August 2014 were identified. Clinical and pathological variables were retrospectively evaluated using univariate and stepwise multivariate logistic regression analysis. Variables that had statistical significance in final multivariate logistic models were chosen to build nomograms, which were further corrected using the bootstrap resampling method.ResultsIn all, 505 PTC patients were eligible for analysis. Among these, 178 patients (35.2%) had lateral neck metastasis. Two nomograms were generated: nomogram (c) and nomogram (c + p). Nomogram (c) incorporated four clinical variables: age, tumor size, tumor site, and extrathyroidal extension (ETE). It had a good discriminative ability, with a C-index of 0.79 (bootstrap-corrected, 0.78). Nomogram (c + p) incorporated two clinical variables and two pathological variables: tumor size, tumor site, extranodal extension (ENE), and number of positive nodes in the central compartment. Nomogram (c + p) showed an excellent discriminative ability, with a C-index of 0.86 (bootstrap-corrected, 0.85).ConclusionTwo predictive nomograms were generated. Nomogram (c) is a clinical model, whereas nomogram (c + p) is a clinicopathological model. Each nomogram incorporates only four variables and can give an accurate estimate of LNM risk in unifocal PTC patients, which may assist clinicians in patient counseling and decision making regarding LND.  相似文献   
104.
105.
刘林  李修红 《现代肿瘤医学》2020,(14):2443-2447
目的:肌少症对老年肝癌术后恢复及预后的影响。方法:选取2015年1月至2017年12月收治的114例老年肝癌,根据有无合并肌少症,分为肌少症组(n=35)和非肌少症组(n=79)。比较两组患者的术后恢复及生存情况。结果:肌少症组总并发症发生率、住院时间和30 d再入院率均高于对照组,差异均有统计学意义(P<0.05)。肌少症组中位生存时间为25.9个月,1年、2年、3年累积总生存率为74.3%、51.1%、24.5%,而非肌少症组中位生存时间为35.7个月,1年、2年、3年累积总生存率为87.3%、75.6%、49.4%,差异有统计学意义(P=0.004)。单因素分析结果显示,老年肝癌术后预后与Charlson合并症指数(CCI)、肌少症、巴塞罗那分期(BCLC)、甲胎蛋白、肿瘤大小、肿瘤个数、肿瘤分化程度、微血管侵犯(MVI)相关(P<0.05)。Cox多因素分析结果显示,CCI、肌少症、BCLC分期、肿瘤个数、MVI是老年肝癌术后预后的独立危险因素(P<0.05)。结论:肌少症会增加老年肝癌患者术后并发症发生率,延长住院时间,影响术后恢复,同时也会降低总生存率。  相似文献   
106.
背景与目的:甲状腺乳头状癌(papillary thyroid carcinoma,PTC)和桥本甲状腺炎(Hashimoto’s thyroiditis,HT)的发病率均呈上升趋势,两者之间的关系已成为目前研究的热点。探讨PTC和HT之间的关系。方法:回顾性分析2014—2015年期间在中国科学院大学附属肿瘤医院头颈肿瘤外科行甲状腺癌手术治疗的首诊患者306例,术后病理学检查均明确诊断为PTC,其中术后病理学确诊伴发HT者42例,比较伴发HT与未伴发HT患者的临床病理学特征。结果:PTC患者女性发病年龄高于男性(46.2岁 vs 41.9岁)。相较于与未伴发HT的PTC患者,伴发HT的患者中女性比例更高(93% vs77%),中央区淋巴结数目较多[(5.0±3.4)枚 vs (2.5±2.7)枚],术前促甲状腺激素(thyroid-stimulating hormone,TSH)水平较高[(3.28±1.91)μU/mL vs (2.12±1.29)μU/mL],术前抗甲状腺过氧化物酶抗体(thyroid peroxidaseantibody,TPOAb)阳性率较高(55% vs 14%),术前甲状腺球蛋白抗体(thyroglobulin antibodies,TgAb)阳性率较高(69% vs 13%)。发生中央区淋巴结转移的患者中,中央区淋巴结转移数目与中央区淋巴结总数显著相关(Pearson相关系数=0.582)。多因素logistic回归分析发现,男性、低龄、被膜侵犯是PTC患者中央区淋巴结转移的独立危险因素。结论:伴发HT对PTC患者的预后无显著影响。伴发HT的PTC患者TSH水平显著偏高,提示HT可能是PTC发病风险因素之一。中央区淋巴结转移数目与中央区淋巴结总数相关,推测PTC淋巴结转移可能与淋巴结炎症反应相关。  相似文献   
107.

Purpose

To evaluate the feasibility of a same-day yttrium-90 (90Y) radioembolization protocol with resin microspheres (including pretreatment angiography, lung shunt fraction [LSF] determination, and radioembolization) for the treatment of hepatocellular carcinoma (HCC) and liver metastases.

Materials and Methods

All same-day radioembolization procedures performed over 1 y (February 2017 to January 2018) were included in this single-institutional retrospective analysis, in which 34 procedures were performed in 26 patients (median age, 63 y; 13 women), 19 with liver metastases and 7 with HCC. Yttrium-90 treatment activities were calculated by body surface area method. Tumor imaging response was assessed by Response Evaluation Criteria In Solid Tumors (RECIST) 1.1 for liver metastases and modified RECIST for HCC. Clinical side effects and adverse events were graded per Common Terminology Criteria for Adverse Events version 4.0.

Results

All planned cases were technically successful, and no cases were canceled for elevated LSF or vascular anatomic reasons. Pretreatment angiography modified the planned 90Y treatment activity in 1 case in which vascular anatomy required a lobar-dose split into 2 for segmental infusions. In 18% of cases, patients were briefly admitted after the procedure for observation or symptom management. Imaging evaluation of initial efficacy at 1 month demonstrated partial response in 25% and stable disease in 67% of patients with liver metastases and partial/complete response in 43% and stable disease in 14% of patients with HCC. Grade ≥ 3 adverse events occurred in 6% of cases, with no systemic therapy–limiting toxicities. The mean total procedure time was 4.2 hours.

Conclusions

A same-day 90Y radioembolization protocol with resin microspheres is feasible in select patients, which can expedite cancer therapy.  相似文献   
108.
109.
110.
MOB kinase activator 1A (MOB1A) plays an important role in many diseases and cancers. Here, we observed that MOB1A was substantially overexpressed in gallbladder carcinoma (GBC) tissues compared with nontumor tissues. The high expression of MOB1A was closely associated with poor survival in patients with GBC at advanced TNM stages. Furthermore, our study indicated that MOB1A promoted autophagy by activating the IL6/STAT3 signaling pathway and regulating the chemosensitivity to gemcitabine under glucose deprivation conditions both in vitro and in vivo. In conclusion, these findings suggested that MOB1A is critical for the development of GBC via the MOB1A-IL6/STAT3-autophagy axis.  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