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   615737篇
  免费   43500篇
  国内免费   30384篇
耳鼻咽喉   4490篇
儿科学   11945篇
妇产科学   7829篇
基础医学   65210篇
口腔科学   8989篇
临床医学   75372篇
内科学   90259篇
皮肤病学   5309篇
神经病学   38020篇
特种医学   24889篇
外国民族医学   262篇
外科学   68195篇
综合类   84328篇
现状与发展   100篇
一般理论   42篇
预防医学   49942篇
眼科学   15631篇
药学   56719篇
  615篇
中国医学   30239篇
肿瘤学   51236篇
  2025年   89篇
  2024年   5515篇
  2023年   8495篇
  2022年   17824篇
  2021年   22046篇
  2020年   17962篇
  2019年   14006篇
  2018年   35173篇
  2017年   30198篇
  2016年   31391篇
  2015年   20578篇
  2014年   25368篇
  2013年   22913篇
  2012年   39592篇
  2011年   57254篇
  2010年   42846篇
  2009年   31285篇
  2008年   43633篇
  2007年   45641篇
  2006年   24168篇
  2005年   24879篇
  2004年   18043篇
  2003年   18523篇
  2002年   14260篇
  2001年   10452篇
  2000年   10431篇
  1999年   10351篇
  1998年   6689篇
  1997年   6398篇
  1996年   4965篇
  1995年   4654篇
  1994年   3916篇
  1993年   2510篇
  1992年   2983篇
  1991年   2631篇
  1990年   2309篇
  1989年   1988篇
  1988年   1635篇
  1987年   1468篇
  1986年   1176篇
  1985年   861篇
  1984年   459篇
  1983年   336篇
  1982年   204篇
  1981年   195篇
  1980年   176篇
  1979年   179篇
  1978年   81篇
  1938年   62篇
  1932年   61篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
In the previous research, we found that anticancer agent LS-1-2F could cause the vacuolation of tumor cells. Herein we investigated the effect of compound LS-1-2F on the endocytosis of macromolecules, including fluorescence quantum dots, human serum albumin, single-stranded RNA, and monoclonal antibody, into tumor cells. We found that LS-1-2F could accelerate the endocytosis of these large molecules by laser confocal microscope and flow cytometry. The effect of LS-1-2F on the improvement of the internalization efficiency of Herceptin biosimilar was particularly significant. Promoting endocytosis will help increase the efficiency of liquid-phase drug uptake in drug-resistant cancer cells and could potentially facilitate the use of drugs in nanoparticle delivery vehicles.  相似文献   
22.
23.
目的:葛根总黄酮(PTF)可治疗心脑血管疾病,但膜通透性差,口服生物利用度低。一些辅料如卡波姆、壳聚糖和羟丙基甲基纤维素可以提高口服生物利用度。传统的体外评价技术,包括大鼠肠灌流和细胞模型,不能评价PTF整体的吸收机制。方法:本研究评价辅料的黏附性及对PTF在Caco-2细胞单层模型中转运的影响。采用cDNA微阵列测定PTF和PTF+辅料给药后的Caco-2细胞的基因表达变化,从基因水平揭示辅料对PTF整体吸收的影响机制。结果:体外黏附和Caco-2细胞转运实验表明,与单独PTF相比,加入辅料后对胃黏膜具有更高的黏附性,且在Caco-2细胞模型中的转运效率更高。PTF与辅料的相互作用显著改变了某些基因的表达,可能影响PTF的吸收效率。结论:不同的生物黏附聚合物能提高PTF的肠道吸收,可能与ATP结合盒(ABC)和溶质载体转运体(SLC)的表达基因有关。  相似文献   
24.
25.
26.
27.
28.
目的探讨前列腺原发胃肠道外间质瘤诊治要点。 方法回顾性分析我院2017年9月诊治的1例高危原发性前列腺胃肠道外间质瘤临床病理特征资料、随访情况,总结现有文献讨论总结本病诊治心得。 结果65岁男性,因"前列腺电切术后2年,反复血尿3个月余"入院。术前MRI考虑为来源不清的盆腔巨大实性占位(115 mm×105 mm×85 mm),经直肠穿刺诊断为梭形细胞来源的肿瘤。行盆腔肿瘤切除+膀胱前列腺腺切除+盆腔淋巴结清扫术+Bricker术。术后病理提示为前列腺原发胃肠道外间质瘤[CD117(+);Dog1(+);CD34(+);PSA(+);AR(+);P504s(+);Ki-67(2%)]。术后肿瘤组织全外显子测序提示为C-Kit基因(Exon 11 p.Q556-V560del)存在明显临床意义突变,筛选靶向药物甲磺酸伊马替尼+比卡鲁胺(PSA平稳后停用)口服,术后随访18个月无肿瘤复发及不良并发症。 结论前列腺原发胃肠道外间质瘤罕见,需与前列腺其他良恶性肿瘤相鉴别诊断。全外显子测序了解其发病高危基因,同时筛选药物辅助治疗可使患者生存获益。  相似文献   
29.
Objective To evaluate the efficacy and safety of lenalidomide plus dexamethasone (LD) in patients with proliferative glomerulonephritis with monoclonal immunoglobulin deposits (PGNMID). Methods The clinicopathological data of PGNMID patients who were treated with LD protocol from January 2010 to October 2019 were retrospectively analyzed. Results All of 6 patients received LD treatment for≥3 months after renal biopsy in Jinling Hospital. During the follow-up period of 6 to 19 months, 3 patients achieved renal remission, and the renal remission rate was 50%(3/6). Light microscopy showed membranoproliferative glomerulonephritis and immunofluorescence showed single kappa type IgG3 was deposited in the mesangial region and the vascular loop. Before taking LD scheme, the median urinary protein were 7.76(1.27, 14.57) g/24 h, the median serum creatinine was 118.5(70.7, 289.1) μmol/L, and the median albumin was 34.5(22.4, 37.5) g/L. The concentration of serum free kappa and lambda light chain was increased in 5 patients, but the serum free light chain ratio was normal. Hypocomplementemia was detected in two cases. Six patients underwent bone marrow flow cytometry, and 2 patients had elevated monoclonal plasma cells, accounting for 0.7% and 0.5%, respectively. Immunofixation electrophoresis suggested that 1 patient had positive serum M protein for kappa type IgG3. At the last follow-up, median urine protein was 3.33(0.33, 11.23) g/24 h, median serum creatinine was 108.7(80.4, 160.9) μmol/L, and median albumin was 35.9(24.5, 45.6) g/L. The concentration of serum free light chain in 4 patients from 5 patients with elevated serum free light chain was lower than that before taking the drug. Decreased level of serum complement in two cases returned to normal after treatment. The M spike did not turn negative during the follow-up in one patient. Adverse events included anemia, neutropenia, limb numbness and upper respiratory tract infection. Conclusion This study reports for the first time that LD protocol may be effective in treating PGNMID, but more attention should be paid to the hematological adverse events of lenalidomide.  相似文献   
30.
Icariin (ICA) is obtained from Epimedium brevicornu maxim and exploited to remedy miscellaneous cancers. But the role of ICA in medulloblastoma remains hazy. The research delved into the antitumor activity of ICA in medulloblastoma DAOY cells. ICA with diverse concentrations was utilized to stimulate DAOY cells, and the biological functions of ICA in medulloblastoma DAOY cells were examined. Then, the relative SPARC expression was determined in ICA‐managed DAOY cells, and the pc‐SPARC vector was transfected into DAOY cells to further probe the influence of SPARC and JAK1/STAT3 and PI3K/AKT pathways in ICA‐managed DAOY cells. A xenograft model was established to investigate the function of ICA in vivo. ICA restrained cell viability, expedited apoptosis, prohibited cell migration and invasion, and meanwhile affected the associative factors expression in DAOY cells. Additionally, SPARC expression was declined in ICA‐stimulated DAOY cells. Overexpressed SPARC reversed the functions of ICA in above‐involved cell behaviors of DAYO cells and the correlative protein levels. Besides, ICA notably frustrated JAK1/STAT3 and PI3K/AKT activations in DAOY cells. Beyond that, ICA prohibited tumor formation in vivo. The results concluded that ICA exhibited the antitumor activity in DAOY cells via decreasing SPARC and inactivating JAK1/STAT3 and PI3K/AKT pathways.  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