全文获取类型
收费全文 | 323337篇 |
免费 | 28362篇 |
国内免费 | 11703篇 |
专业分类
耳鼻咽喉 | 2783篇 |
儿科学 | 4741篇 |
妇产科学 | 5341篇 |
基础医学 | 54985篇 |
口腔科学 | 7429篇 |
临床医学 | 23587篇 |
内科学 | 39683篇 |
皮肤病学 | 4763篇 |
神经病学 | 20983篇 |
特种医学 | 11290篇 |
外国民族医学 | 73篇 |
外科学 | 29229篇 |
综合类 | 47736篇 |
现状与发展 | 54篇 |
一般理论 | 10篇 |
预防医学 | 18436篇 |
眼科学 | 5410篇 |
药学 | 37668篇 |
107篇 | |
中国医学 | 16834篇 |
肿瘤学 | 32260篇 |
出版年
2024年 | 236篇 |
2023年 | 3885篇 |
2022年 | 5684篇 |
2021年 | 11653篇 |
2020年 | 10636篇 |
2019年 | 10146篇 |
2018年 | 10193篇 |
2017年 | 11479篇 |
2016年 | 12247篇 |
2015年 | 12403篇 |
2014年 | 16434篇 |
2013年 | 21906篇 |
2012年 | 17698篇 |
2011年 | 20904篇 |
2010年 | 14998篇 |
2009年 | 14964篇 |
2008年 | 16707篇 |
2007年 | 17895篇 |
2006年 | 16646篇 |
2005年 | 14944篇 |
2004年 | 12773篇 |
2003年 | 11029篇 |
2002年 | 8842篇 |
2001年 | 7861篇 |
2000年 | 6604篇 |
1999年 | 5573篇 |
1998年 | 4408篇 |
1997年 | 4299篇 |
1996年 | 3908篇 |
1995年 | 3956篇 |
1994年 | 3694篇 |
1993年 | 3077篇 |
1992年 | 2695篇 |
1991年 | 2505篇 |
1990年 | 2132篇 |
1989年 | 1880篇 |
1988年 | 1731篇 |
1987年 | 1562篇 |
1986年 | 1393篇 |
1985年 | 2007篇 |
1984年 | 1688篇 |
1983年 | 1227篇 |
1982年 | 1384篇 |
1981年 | 1099篇 |
1980年 | 991篇 |
1979年 | 834篇 |
1978年 | 555篇 |
1977年 | 451篇 |
1976年 | 414篇 |
1975年 | 251篇 |
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
51.
52.
目的:探讨消化道肿瘤中同源重组修复相关基因(homologous recombination repair related gene,HRR)突变的发生情况及临床意义。方法:共92例消化道肿瘤患者,79例患者进行了血液标本HRR检测,53例患者进行了组织标本HRR检测,40例患者同时行血液和组织的HRR基因检测,收集患者基因检测结果及临床相关资料。结果:在79例患者血液标本检测中发现10例(12.6%)有临床意义HRR突变,在53例患者组织标本检测中发现9例(17.0%)有临床意义HRR突变。40例同时行血液和组织的HRR基因检测患者中常见的有临床意义HRR突变为CDK12突变4例(10.0%)、ATM突变3例(7.5%)、BRCA1突变2例(5.0%)。13例有临床意义HRR突变患者中常见共存突变为TP53突变10例(76.9%)、APC突变5例(38.5%)、PIK3CA突变4例(30.8%)。40例患者中13例患者血液和/或组织中有临床意义HRR突变,27例患者血液和组织中均无任何临床意义HRR突变且两组相比,有临床意义HRR突变组肿瘤突变负荷(tumor mutational burden,TMB)为6.17(2.24~11.52),而未携带HRR突变组TMB为0.4(0~3.75),差异有统计学意义(P<0.05)。40例患者组织检测中7例HRR有临床意义的突变,33例无HRR突变,血液检测中10例HRR有临床意义的突变,30例无HRR突变,一致性检验的Kappa值为0.333(P=0.031)。结论:携带有临床意义HRR突变的消化道肿瘤患者TMB更高,血液和组织检测HRR突变有较好的一致性。 相似文献
53.
肥厚型心肌病(HCM)是一种常见的遗传性心脏病,是青少年及年轻运动员心源性猝死的最主要原因之一,其分子遗传学基础为基因突变。TNNC1是HCM的重要致病基因之一,目前仅发现其少量非同义单核苷酸多态性(nsSNPs)位点与HCM发病相关,但该基因其他nsSNPs数量较多,结合临床进行实验遗传检测其基因型与表型的关系,工作量巨大,尚不可行。因此,采用生物信息学方法,从dbSNP数据库中筛选出TNNC1基因全部的nsSNPs,联合4款(Mutation Taster、PolyPhen-2、PhD-SNP和MutPred)专业软件,进行有害性分级筛选和致病关联预测,最后进行突变蛋白三维结构建模及可视化分析。结果显示,首次从TNNC1基因102个nsSNPs位点中预测出疾病相关的18个(G159D、S69R、P52R、D149G、D3V、G140E、N51K、D151V、M47R、G110C、A23D、G140R、K158N、C35Y、R147C、L48P、F74C和V44G)高风险nsSNPs。基于生物信息学方法,以TNNC1基因的nsSNPs为示范,分析其nsSNPs与疾病表型的关系,这为其他遗传疾病致病基因nsSNPs的关联分析打下理论研究基础,具有重要的参考价值。 相似文献
54.
55.
Laura A. Huppert MD Ozge Gumusay MD Dame Idossa MD Hope S. Rugo MD 《CA: a cancer journal for clinicians》2023,73(5):480-515
Hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer is defined by the presence of the estrogen receptor and/or the progesterone receptor and the absence of HER2 gene amplification. HR-positive/HER2-negative breast cancer accounts for 65%–70% of all breast cancers, and incidence increases with increasing age. Treatment varies by stage, and endocrine therapy is the mainstay of treatment in both early stage and late-stage disease. Combinations with cyclin-dependent kinase 4/6 inhibitors have reduced distant recurrence in the early stage setting and improved overall survival in the metastatic setting. Chemotherapy is used based on stage and tumor biology in the early stage setting and after endocrine resistance for advanced disease. New therapies, including novel endocrine agents and antibody-drug conjugates, are now changing the treatment landscape. With the availability of new treatment options, it is important to define the optimal sequence of treatment to maximize clinical benefit while minimizing toxicity. In this review, the authors first discuss the pathologic and molecular features of HR-positive/HER2-negative breast cancer and mechanisms of endocrine resistance. Then, they discuss current and emerging therapies for both early stage and metastatic HR-positive/HER2-negative breast cancer, including treatment algorithms based on current data. 相似文献
56.
《Saudi Pharmaceutical Journal》2022,30(4):398-406
IntroductionThe risk of mortality in patients with COVID-19 was found to be significantly higher in patients who experienced thromboembolic events. Thus, several guidelines recommend using prophylactic anticoagulants in all COVID-19 hospitalized patients. However, there is uncertainty about the appropriate dosing regimen and safety of anticoagulation in critically ill patients with COVID-19. Thus, this study aims to compare the effectiveness and safety of standard versus escalated dose pharmacological venous thromboembolism (VTE) prophylaxis in critically ill patients with COVID-19.MethodsA two-center retrospective cohort study including critically ill patients aged ≥ 18-years with confirmed COVID-19 admitted to the intensive care unit (ICU) at two tertiary hospitals in Saudi Arabia from March 1st, 2020, until January 31st, 2021. Patients who received either Enoxaparin 40 mg daily or Unfractionated heparin 5000 Units three times daily were grouped under the “standard dose VTE prophylaxis and patients who received higher than the standard dose but not as treatment dose were grouped under ”escalated VTE prophylaxis dose“. The primary outcome was the occurance of thrombotic events, and the secondary outcomes were bleeding, mortality, and other ICU-related complications.ResultsA total of 758 patients were screened; 565 patients were included in the study. We matched 352 patients using propensity score matching (1:1). In patients who received escalated dose pharmacological VTE prophylaxis, any case of thrombosis and VTE were similar between the two groups (OR 1.22;95 %CI 0.52–2.86; P = 0.64 and OR 0.75; 95% CI 0.16–3.38; P = 0.70 respectively). However, the odds of minor bleeding was higher in patients who received escalated VTE prophylaxis dose (OR 3.39; 95% CI 1.08–10.61; P = 0.04). There was no difference in the 30-day mortality nor in-hospital mortality between the two groups (HR 1.17;95 %CI0.79–1.73; P = 0.43 and HR 1.08;95 %CI 0.76–1.53; P = 0.83, respectively).ConclusionEscalated-dose pharmacological VTE prophylaxis in critically ill patients with COVID-19 was not associated with thrombosis, or mortality benefits but led to an increased risk of minor bleeding. This study supports previous evidence regarding the optimal dosing VTE pharmacological prophylaxis regimen for critically ill patients with COVID-19. 相似文献
57.
58.
《European journal of surgical oncology》2022,48(6):1264-1271
BackgroundIn order to avoid excessive treatment of thyroid nodules in the clinic, it is necessary to find a simple and practical analysis method to comprehensively and accurately reflect benign or malignant thyroid nodules. This study aimed to construct and validate a comprehensive and reliable network-based predictive model using a variety of imaging and laboratory criteria for thyroid nodules to stratify the risk of malignancy prior to surgery.MethodsWe retrospectively analyzed data from patients who underwent surgical treatment for thyroid nodules at the Thyroid and Breast Diagnosis and Treatment Center of Weifang Hospital of Traditional Chinese Medicine between January 2018 and December 2020. Binary logical regression analysis was performed to predict whether nodules were malignant or benign. The developmental dataset included 457 patients (January 2018–December 2020). The validation set included separate data points (n = 225, January 2018–December 2020).ResultsIn this study, criteria that showed significant predictive value for malignant nodules included TI-RADS: 4b (p = 0.065); Bethesda IV, Bethesda V, Bethesda VI (P < 0.0001); BRAFV600E mutation (P < 0.0001); Calcitonin>5 pg/ml (p = 0.0037); and FNA-Tg>30 ng/ml (p = 0.0003). A 10-grade risk scoring system was developed. The risk of malignancy risk ranged from 2.06% to 100% and was positively associated with increasing risk grade. The areas under the receiver-operating characteristic curve of the development and validation sets were 0.972 and 0.946, respectively.ConclusionA simple, comprehensive and reliable web-based predictive model was designed using a variety of imaging and laboratory criteria to stratify thyroid nodules by probability of malignancy. 相似文献
59.
- DNA is the sequence that codes for proteins.
- Messenger RNA is transcribed from the DNA sequence of genes and translated into protein.
- It can be difficult to predict how a change in the DNA sequence will affect messenger RNA and protein quantity and quality.
- DNA translocation changes can cause the joining of sequences from two different genes or different parts of the same gene.
- DNA sequencing is often used clinically to predict how DNA changes might affect proteins.
- Alternatively, RNA sequencing can be used as a more direct measure of the effect of DNA changes on the protein products.
- This sequencing is important for identifying changes in cancer that may indicate response to targeted therapy, prognosis, or diagnosis.
60.
Marie V. Plaisime PhD MPH Marie Jipguep-Akhtar PhD Joseph J. Locascio PhD Harolyn M. E. Belcher MD MHS Rachel R. Hardeman PhD MPH Katherine Picho-Kiroga PhD Sylvia P. Perry PhD Sean M. Phelan PhD MPH Michelle van Ryn PhD LMFT MPH John F. Dovidio PhD 《Health services research》2023,58(Z2):229-237