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   4618篇
  免费   429篇
  国内免费   275篇
耳鼻咽喉   42篇
儿科学   89篇
妇产科学   57篇
基础医学   594篇
口腔科学   81篇
临床医学   600篇
内科学   771篇
皮肤病学   22篇
神经病学   232篇
特种医学   260篇
外国民族医学   1篇
外科学   439篇
综合类   723篇
预防医学   291篇
眼科学   44篇
药学   521篇
  4篇
中国医学   192篇
肿瘤学   359篇
  2024年   7篇
  2023年   57篇
  2022年   84篇
  2021年   174篇
  2020年   167篇
  2019年   143篇
  2018年   128篇
  2017年   123篇
  2016年   92篇
  2015年   167篇
  2014年   246篇
  2013年   203篇
  2012年   293篇
  2011年   366篇
  2010年   220篇
  2009年   178篇
  2008年   252篇
  2007年   233篇
  2006年   216篇
  2005年   247篇
  2004年   174篇
  2003年   116篇
  2002年   113篇
  2001年   110篇
  2000年   114篇
  1999年   133篇
  1998年   140篇
  1997年   119篇
  1996年   97篇
  1995年   76篇
  1994年   91篇
  1993年   55篇
  1992年   57篇
  1991年   47篇
  1990年   26篇
  1989年   51篇
  1988年   43篇
  1987年   27篇
  1986年   26篇
  1985年   18篇
  1984年   11篇
  1983年   10篇
  1982年   11篇
  1981年   14篇
  1980年   11篇
  1979年   8篇
  1978年   6篇
  1977年   10篇
  1976年   6篇
  1975年   3篇
排序方式: 共有5322条查询结果,搜索用时 390 毫秒
1.
经皮椎体成形术是一种安全有效的微创手术,腹膜后血肿是其罕见但严重的并发症。我们报告一例经皮椎体成形术RH阴性(熊猫血)患者术后并发巨大腹膜后血肿,经保守和输血等支持治疗,病人康复出院。脊柱医生应了解这种罕见但潜在致命的并发症,因为早期认识和及时预防是降低其发病率的基础。  相似文献   
2.
3.
目的探讨耳内镜下夹层法鼓膜成形术治疗鼓膜大穿孔的临床疗效。方法回顾性分析该科在2017年1月-2017年10月对18例患者的21侧鼓膜大穿孔进行耳内镜下夹层法鼓膜成形术,统计分析手术时间、出血量,术后6个月随访观察鼓膜愈合情况,比较术前和术后的听力情况。结果21侧患耳平均手术时间(44.95±8.50)min,手术平均出血量(19.19±3.16)ml。19侧鼓膜完全愈合,鼓膜成形术成功率为90.48%;2侧鼓膜完全愈合后因真菌感染再次穿孔。术后6个月的平均气导听阈、平均气骨导差较术前下降,差异有统计学意义(P<0.05)。结论耳内镜下夹层法鼓膜成形术治疗鼓膜大穿孔具有创伤小、恢复快和疗效好的优点,是一种值得推广的手术方法。  相似文献   
4.
Abstract

Children are considered a vulnerable group and as such are granted additional protection as research subjects. Research projects using children as research subjects are justifiable if the answer to the scientific question of the study cannot be obtained by enrolling adult subjects (cf. scientific necessity). Thus, there is an ethical obligation to explore innovative analytical strategies that seek balance between the feasibility of conducting a trial and maximizing the utilization of data on efficacy and safety. On this note, there is enthusiasm for implementing some less popular but efficient alternative designs for confirmatory pediatric trials. Within the pediatric extrapolation paradigm, examples of such designs, other than purely based on pharmacokinetic/pharmacodynamic data, are described in this article along with their advantages and disadvantages. This article will also discuss how to incorporate alternative data sources in the analysis of pediatric clinical trials. A discussion of existing approaches and a road-map to their utilization will be provided. Real case examples on the use of the approaches are provided.  相似文献   
5.
Background: Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide, and the prognosis of HNSCC remains bleak. Numerous studies revealed that the tumor mutation burden (TMB) could predict the survival outcomes of a variety of tumors.Objectives: This study aimed to investigate the TMB and immune cell infiltration in these patients and construct an immune-related genes (IRGs) prognostic model.Methods: The expression data of 546 HNSCC patients were obtained from The Cancer Genome Atlas (TCGA) database. All patients were divided into high- and low- TMB groups, and the relationship between TMB and clinical relevance was further analyzed. The differentially expressed genes (DEGs) were identified using the R software package, limma. Functional enrichment analyses were conducted to identify the significantly enriched pathways between two groups. CIBERSORT algorithm was adopted to calculate the abundance of 22 leukocyte subtypes. The IRGs prognostic model was constructed via the multivariate Cox regression analysis.Results: Missense mutation and single nucleotide variants (SNV) were the most predominant mutation types in HNSCC. TP53, TTN, and FAT1 were the most frequently mutated genes. Patients with high TMB were observed with worse survival outcomes. The functional analysis of TMB associated DEGs showed that the identified DEGs mainly involved in spliceosome, RNA degradation, proteasome, and RNA polymerase pathways. We observed that macrophages, T cells CD8, and T cells CD4 memory were the most commonly infiltrated subtypes of immune cells in HNSCC. Finally, an IRGs prognostic model was constructed, and the AUC of the ROC curve was 0.635.Conclusions: Our results suggest that high TMB is associated with poor prognosis in HNSCC patients. The constructed model has potential prognostic value for the prognosis of these individuals, and it needs to be further validated in large-scale and prospective studies.  相似文献   
6.
7.
BackgroundTo introduce and determine the value of optimized strategies for the management of urological tube-related emergencies with increased incidence, complexity and operational risk during the global spread of coronavirus disease 2019 (COVID-19).MethodsAll emergent urological patients at Tongji Hospital, Wuhan, during the period of January 23 (the beginning of lockdown in Wuhan) to March 23, 2020, and the corresponding period in 2019 were recruited to form this study’s COVID-19 group and control group, respectively. Tongji Hospital has the most concentrated and strongest Chinese medical teams to treat the largest number of severe COVID-19 patients. Patients in the control group were routinely treated, while patients in the COVID-19 group were managed following the optimized principles and strategies. The case incidence for each type of tube-related emergency was recorded. Baseline characteristics and management outcomes (surgery time, secondary complex operation rate, readmission rate, COVID-19 infection rate) were analyzed and compared across the control and COVID-19 periods.ResultsThe total emergent urological patients during the COVID-19 period was 42, whereas during the control period, it was 124. The incidence of tube-related emergencies increased from 53% to 88% (P<0.001) during the COVID-19 period. In particular, the incidence of nephrostomy tube-related (31% vs. 15%, P=0.027) and single-J stent-related problems (19% vs. 6%, P=0.009) increased significantly. The mean surgery times across the two periods were comparable. The number of secondary complex operations increased from 12 (18%) to 14 (38%) (P=0.028) during the COVID 19-period. The number of 2-week postoperative readmission decreased from 10 (15%) to 1 (3%) (P=0.049). No participants contracted during the COVID-19 period.ConclusionsUrological tube-related emergencies have been found to have a higher incidence and require more complicated and dangerous operations during the COVID-19 pandemic. However, the optimized management strategies introduced in this study are efficient, and safe for both urologists and patients.  相似文献   
8.
目的  通过建立公立医院合作决策模型,实现在任选决策单元中选择最佳合作伙伴,提升医疗资源利用效率,推动区域内医疗资源最佳配置。方法  在传统数据包络分析(data envelopment analysis,DEA)模型的基础上,构建对模糊指标和任选决策单元具有更好适用性的广义模糊DEA合作决策模型,通过输入职工总数、病床数、年门急诊量、出院人数、总收入、医院等级评价等指标信息,计算出某一区域内不同医院的合作效率区间,从而实现在任选决策单元中科学选择最佳合作伙伴。结果  以河南省某地区10所医院为例进行分析验证可知,广义模糊DEA模型对该区域内公立医院之间的合作决策具有很好的效果,可有效为区域内任一医院选择最佳合作伙伴。结论  与传统DEA方法相比,广义模糊DEA方法更具灵活性,能较好地评价复杂模型,可以对任选决策单元中的个体实现最优合作决策选择,为实现区域医疗资源优化配置提供决策支撑。  相似文献   
9.
Circular RNAs (circRNAs) have a covalently closed circular conformation and are structurally stable. Those circRNAs with tumor‐suppressive properties play an important role in tumorigenesis and metastasis and thus may be used as therapeutic targets of cancers. Herein, we review the current understanding of the classification of circRNAs and summarize the functions and mechanisms of circRNAs that have tumor‐suppressive roles in various cancers, including liver cancer (circARSP91, circADAMTS13, circADAMTS14, circMTO1, hsa_circ_0079299, and circC3P1), bladder cancer (circFNDC3B, circITCH, circHIPK3, circRNA‐3, cdrlas, and circLPAR1), gastric cancer (circLARP4, circYAP1, hsa_cric_0000096, hsa_circ_0000993, and circPSMC3), breast cancer (circ_000911, hsa_circ_0072309, and circASS1), lung cancer (hsa_circ_0000977, circPTK2, circ_0001649, hsa_circ_100395, and circ_0006916), glioma (circ_0001946, circSHPRH, and circFBXW7), and colorectal cancer (circITGA7 and hsa_circ_0014717). Thanks to their structural stability, these tumor‐suppressive circRNAs may be used as potential and potent therapeutic targets. Moreover, we propose a new method for the classification of circRNAs. Based on whether they can be translated, circRNAs can be divided into noncoding circRNAs and coding circRNAs.  相似文献   
10.
Objective: The 2019 novel coronavirus (2019?nCoV) outbreak has escalated into a global pandemic. According to Chinese guidance for coronavirus disease?19 (COVID?19): Prevention, control, diagnosis, and management, Reduning injection can effectively treat, the disease caused by the virus. To identify the active ingredients of Reduning injection and COVID?19 disease?related pathways, we conducted a network pharmacology study. Methods: The Traditional Chinese Medicine Systems Pharmacology database was used to screen the chemical constituents and potential targets of Reduning injection. The gene names were converted to the corresponding protein names using UniProt. GeneCards and OMIM databases were used to select targets related to 2019?nCoV. Using Cytoscape 3.7.2 software platform and STRING database, we constructed drug?common target and target protein protein?protein interaction network diagrams. Rx64 3.6.2 software and Bioconductor biological information software package were used for? Gene Ontology (GO) functional enrichment and KEGG pathway analyses. Results: In Reduning injection, a total of 33 effective chemical components were obtained that were involved in 151 signaling pathways, of which 44 targets were considered therapeutically relevant. Conclusion: Reduning injection can be potentially applied for the treatment of COVID-19 based on the results of our network pharmacology study.  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