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   21519篇
  免费   2527篇
  国内免费   921篇
耳鼻咽喉   235篇
儿科学   333篇
妇产科学   483篇
基础医学   2934篇
口腔科学   359篇
临床医学   1682篇
内科学   4438篇
皮肤病学   349篇
神经病学   1137篇
特种医学   360篇
外国民族医学   1篇
外科学   2589篇
综合类   2829篇
一般理论   1篇
预防医学   1168篇
眼科学   280篇
药学   2340篇
  4篇
中国医学   726篇
肿瘤学   2719篇
  2024年   36篇
  2023年   556篇
  2022年   835篇
  2021年   1726篇
  2020年   1533篇
  2019年   1683篇
  2018年   1648篇
  2017年   1107篇
  2016年   862篇
  2015年   1199篇
  2014年   1645篇
  2013年   1387篇
  2012年   1146篇
  2011年   1277篇
  2010年   975篇
  2009年   793篇
  2008年   784篇
  2007年   797篇
  2006年   612篇
  2005年   527篇
  2004年   470篇
  2003年   465篇
  2002年   283篇
  2001年   220篇
  2000年   212篇
  1999年   211篇
  1998年   296篇
  1997年   227篇
  1996年   145篇
  1995年   137篇
  1994年   117篇
  1993年   83篇
  1992年   83篇
  1991年   69篇
  1990年   48篇
  1989年   56篇
  1988年   60篇
  1987年   35篇
  1986年   39篇
  1985年   83篇
  1984年   76篇
  1983年   56篇
  1982年   69篇
  1981年   59篇
  1980年   63篇
  1979年   58篇
  1978年   33篇
  1977年   28篇
  1976年   16篇
  1974年   14篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Clinical breast cancer》2022,22(6):507-514
Breast cancer (BC) is a highly metastatic, pathological cancer that significantly affects women worldwide. The mortality rate of BC is related to its heterogeneity, aggressive phenotype, and metastasis. Recent studies have highlighted that the tumor microenvironment (TME) is critical for the interplay between metastasis mediators in BC. BC stem cells, tumor-derived exosomes, circulatory tumor cells (CTCs), and signaling pathways dynamically remodel the TME and promote metastasis. This review examines the cellular and molecular mechanisms governing the epithelial to mesenchymal transition (EMT) that facilitate metastasis. This review also discusses the role of cancer stem cells (CSCs), tumor-derived exosomes, and CTs in promoting BC metastasis. Furthermore, the review emphasizes major signaling pathways that mediate metastasis in BC. Finally, the interplay among CSCs, exosomes, and CTCs in mediating metastasis have been highlighted. Therefore, understanding the molecular cues that mediate the association of CSCs, exosomes, and CTCs in TME helps to optimize systemic therapy to target metastatic BC.  相似文献   
2.
Objective Pegylated-interferon monotherapy is the standard treatment for patients with chronic hepatitis B; however, the factors associated with its therapeutic effects remain unclear. Methods Patients with chronic hepatitis B were treated with pegylated interferon α-2a for 48 weeks. We evaluated the kinetics of hepatitis B surface antigen (HBsAg) during treatment and follow-up periods and the factors associated with an HBsAg response (defined as a change in HBsAg of ≥-1 log IU/mL from baseline). Results The study population comprised 50 patients. The median baseline levels of hepatitis B virus DNA and HBsAg were 5.00 and 3.40 log IU/mL. The median values of HBsAg reduction from baseline were -0.44 (n=48), -0.41 (n=40), and -0.68 (n=11) log IU/mL at the end of treatment and at 48 and 144 weeks post-treatment, respectively. The rates of HBsAg response were 24.0% and 22.5% at the end of treatment and at 48 weeks post-treatment, respectively. A multivariate analysis identified HBsAg <3.00 log IU/mL as an independent baseline factor contributing to the HBsAg response at the end of treatment and 48 weeks post-treatment (p=1.07×10-2 and 4.42×10-2, respectively). There were significant differences in the reduction of the HBsAg levels at 12 weeks of treatment and in the incidence of serum ALT increase during treatment between patients with and without an HBsAg response. Conclusion These findings suggest that the baseline HBsAg level, HBsAg kinetics at 12 weeks of treatment, and ALT increase during treatment are important factors contributing to the HBsAg response in pegylated interferon α-2a monotherapy for patients with chronic hepatitis B.  相似文献   
3.
驱动基因的发现及针对驱动基因的靶向治疗已显著提高了肺癌患者的生存质量和时间,但目前对于BRAFHER2METRET等少见驱动基因改变肺癌患者的靶向药物的选择仍然较少。近年来免疫检查点抑制剂在肺癌治疗中取得了一定的疗效,但因为少见驱动基因突变的肺癌患者本身样本量少,开展大规模临床随机对照试验尚存在一定的困难,目前此类患者接受免疫检查点抑制剂治疗的疗效情况仍不明确。本文将对目前已掌握的免疫检查点抑制剂治疗BRAFHER2METRET等少见驱动基因改变肺癌患者的临床研究结果进行综述,以期在一定程度上为临床工作提供一些依据和参考。  相似文献   
4.
5.
6.
We demonstrate the case of a surgery in a patient with irreducible atlantoaxial dislocation (IrAAD) after C2 fracture. The challenges of this case were the flexed head in a forced position, impossibility of neck extension, and revision operation after posterior occipito-cervical fixation. The patient underwent the following surgeries: 1. A ventral release of C1-C2 using transcervical endoscopy; 2. Removal of occipito-cervical system and fibrous block resection in the posterior surfaces of the C1-C2; 3. Reducing of AAD and odontoid screw fixation; 4. Posterior C1-C2-C3 screw fixation. Ankylosing of C1-C2 and C2-C3-C4 fusion was verified by computed tomography scan. There was an improvement in patient status as observed by the increase of the SF-36 scale scores.The use of endoscopic transcervical approach is a good alternative to the transoral approach. Comparative studies of these methods should be performed regarding the choice of an optimal method of decompression in cases of IrAAD.  相似文献   
7.
肺癌是世界上发病率最高的癌症之一,且尚无二线进展后的标准治疗方案,而肿瘤血管生成目前已被确定为恶性肿瘤的重要治疗靶点,小分子多靶点血管激酶抑制剂可通过抑制血管生成相关信号通路,抑制肿瘤血管的生成。目前已开展多项小分子抗血管生成药物治疗非小细胞肺癌的临床试验,且已有部分血管内皮生长因子受体酪氨酸激酶抑制剂(vascular endothelial growth factor receptor-tyrosine kinase inhibitors, VEGFR-TKIs)获批治疗晚期非小细胞肺癌,本文基于国内外多项小分子抗血管生成药物治疗非小细胞肺癌的发展现状,归纳了多个VEGFR-TKIs及成纤维细胞生长因子受体(fibroblast growth factor receptor, FGFR)-TKI单药或联合[包括分别与化疗、表皮生长因子受体(epidermal growth factor receptor, EGFR)-TKIs、免疫治疗、放疗等联合)]治疗非小细胞肺癌的疗效与安全性研究,同时探讨了VEGFR-TKIs可能存在的耐药机制及疗效预测指标等,并对未来抗血管治疗非小细胞肺癌的发展趋势以及存在的潜在问题进行展望,同时为肺癌后续的精准治疗及个体化治疗提供新的思路。  相似文献   
8.
9.
ObjectivesWe evaluated breast cancer (BC) care quality indicators (QIs) in clinical pathways and integrated health care processes.MethodsFollowing protocol registration (Prospero no: CRD42021228867), relevant documents were identified, without language restrictions, through a systematic search of bibliographic databases (EMBASE, Scopus, Web of Science, MEDLINE), health care valuable representatives and the World Wide Web in April 2021. Data concerning QIs, measurement tools and compliance standards were extracted from European and North American sources in duplicate with 98% reviewer agreement.ResultsThere were 89 QIs found from 22 selected documents (QI per document mean 13.5 with standard deviation 11.9). The Belgian (38 QIs) and the EUSOMA (European Society of Breast Cancer Specialists) (34 QIs) documents were the ones that best reported the QIs. No identical QI was identified in all the documents analysed. There were 67/89 QIs covering processes (75.3%) and 11/89 (12.4%) for each structure and outcomes QIs. There were 21/89 QIs for diagnosis (30.3%), 43/89 for treatment (48.3%), and 19/89 for staging, counselling, follow-up and rehabilitation (21.4%). Of 67 process QIs and 11 outcome QIs, 20/78 (26%) did not report a minimum standard of care. Shared decision making was only included as a QI in the Italian document.ConclusionMore than half of countries have not established a national clinical pathway or integrated breast cancer care process to achieve the excellence of BC care. There was heterogeneity in QIs for the evaluation of BC care quality. Over two-thirds of the clinical pathways and integrated health care processes did not provide a minimum auditable standard of care for compliance, leaving open the definition of best practice. There is a need for harmonisation of BC care QIs.  相似文献   
10.
《Drug discovery today》2022,27(6):1733-1742
Compounds that exhibit assay interference or undesirable mechanisms of bioactivity are routinely encountered in assays at various stages of drug discovery. We observed that assays for the investigation of thiol-reactive and redox-active compounds have not been collected in a comprehensive review. Here, we review these assays and subject them to experimental optimization to improve their reliability. We demonstrate the usefulness of our assay cascade by assaying a library of bioactive compounds, chemical probes, and a set of approved drugs. These high-throughput assays should complement the array of wet-lab and in silico assays during the initial stages of hit discovery campaigns to pursue only hit compounds with tractable mechanisms of action.  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