全文获取类型
收费全文 | 2923篇 |
免费 | 282篇 |
国内免费 | 67篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 274篇 |
妇产科学 | 67篇 |
基础医学 | 688篇 |
口腔科学 | 83篇 |
临床医学 | 221篇 |
内科学 | 676篇 |
皮肤病学 | 36篇 |
神经病学 | 59篇 |
特种医学 | 20篇 |
外科学 | 267篇 |
综合类 | 442篇 |
预防医学 | 148篇 |
眼科学 | 98篇 |
药学 | 110篇 |
中国医学 | 24篇 |
肿瘤学 | 42篇 |
出版年
2024年 | 2篇 |
2023年 | 41篇 |
2022年 | 21篇 |
2021年 | 102篇 |
2020年 | 89篇 |
2019年 | 103篇 |
2018年 | 95篇 |
2017年 | 78篇 |
2016年 | 99篇 |
2015年 | 99篇 |
2014年 | 147篇 |
2013年 | 198篇 |
2012年 | 120篇 |
2011年 | 141篇 |
2010年 | 126篇 |
2009年 | 137篇 |
2008年 | 166篇 |
2007年 | 156篇 |
2006年 | 163篇 |
2005年 | 141篇 |
2004年 | 130篇 |
2003年 | 122篇 |
2002年 | 78篇 |
2001年 | 89篇 |
2000年 | 54篇 |
1999年 | 79篇 |
1998年 | 48篇 |
1997年 | 45篇 |
1996年 | 49篇 |
1995年 | 45篇 |
1994年 | 46篇 |
1993年 | 33篇 |
1992年 | 36篇 |
1991年 | 28篇 |
1990年 | 23篇 |
1989年 | 19篇 |
1988年 | 12篇 |
1987年 | 11篇 |
1986年 | 13篇 |
1985年 | 27篇 |
1984年 | 16篇 |
1983年 | 8篇 |
1982年 | 16篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 4篇 |
排序方式: 共有3272条查询结果,搜索用时 31 毫秒
41.
[目的 ]探讨慢性病毒性肝炎合并巨细胞病毒感染对肝功能及病毒复制的影响 .[方法 ]分别检测了 3 2例慢性病毒性肝炎患者抗 巨细胞病毒IgM、乙型肝炎病毒血清学标志、抗 丙型病毒性肝炎抗体及生物化学指标 ;另选择 2 0例健康人 ,检测其抗 巨细胞病毒IgM ,与慢性病毒性肝炎患者的作对照 .[结果 ]慢性乙型肝炎病例中抗 巨细胞病毒IgM阳性率为 4 1% ,慢性丙型肝炎病例中抗 巨细胞病毒IgM阳性率为 4 0 % .血清抗 巨细胞病毒IgM阳性的慢性肝炎患者总胆红素、谷丙转氨酶水平及肝功能复常天数均明显升高或延长 ,并伴有发热、呕吐、黄疸、肝大症状或体征的加重 .[结论 ]巨细胞病毒感染好发于免疫虚损的宿主 ,又可抑制宿主免疫功能 ,有利于病毒复制 .合并巨细胞病毒感染可加重肝功能障碍 . 相似文献
42.
43.
人巨细胞病毒感染与宫颈癌关系的研究 总被引:1,自引:0,他引:1
采用聚合酶链反应 (PCR)检测 30例宫颈癌、 30例宫颈炎、 8例正常宫颈组织标本中 HCMV早期 (IE)、晚期 (L)基因片段、 HCMV79- aa ORF癌基因及 HPV16、 18、 32、 5 2 b、 5 8型 DNA。结果表明 :除 HCMV L 基因外 ,以上各基因在宫颈癌组之检出率均显著高于宫颈炎组 ,且宫颈癌组 IE和 L 基因、HPV高危型和 HCMV同时感染的比值比 (OR)分别高于 IE或 L 基因、HPV高危型或 HCMV单独感染的 OR值之和。提示人巨细胞病毒与宫颈癌的发生有关 ,可通过其 IE基因启动、激活 HPV的致癌作用 ,HCMV79- aa ORF癌基因的整合也可能是致宫颈癌的一个不可忽视的重要因素 相似文献
44.
【目的】探讨人巨细胞病毒 (HCMV)对红系祖细胞 (CFU E)的分化和增殖的影响 ,并初步探讨其作用机制。【方法】取 15例脐血标本 ,用红系祖细胞单向半固体培养技术 ,观察 3种不同浓度的HCMVAD16 9株对CFU E集落形成的影响 ,用PCR和RT PCR检测集落中的HCMVDNA与latemRNA。【结果】 3个感染组的CFU E均减少 ,与正常对照组比较 ,分别为 11 46 %、2 1 88%、34 45 % (P <0 0 5 ) ,显示CFU E集落数与HCMV感染浓度有关 ,病毒感染浓度越高 ,抑制程度越大。CFU E集落细胞中的HCMVDNA均为阳性 ,而latemRNA为阴性。【结论】HCMVAD16 9株可直接感染红系祖细胞 ,并抑制其分化与增殖 ,该抑制作用可出现于仅有病毒潜伏的细胞。 相似文献
45.
Vu Thuy Khanh Le-Trilling Jana-Fabienne Ebel Franziska Baier Kerstin Wohlgemuth Kai Robin Pfeifer Aart Mookhoek Philippe Krebs Madita Determann Benjamin Katschinski Alexandra Adamczyk Erik Lange Robert Klopfleisch Christian M. Lange Viktoriya Sokolova Mirko Trilling Astrid M. Westendorf 《European journal of immunology》2023,53(2):2249940
Primary and recurrent cytomegalovirus (CMV) infections frequently cause CMV colitis in immunocompromised as well as inflammatory bowel disease (IBD) patients. Additionally, colitis occasionally occurs upon primary CMV infection in patients who are apparently immunocompetent. In both cases, the underlying pathophysiologic mechanisms are largely elusive - in part due to the lack of adequate access to specimens. We employed the mouse cytomegalovirus (MCMV) model to assess the association between CMV and colitis. During acute primary MCMV infection of immunocompetent mice, the gut microbial composition was affected as manifested by an altered ratio of the Firmicutes to Bacteroidetes phyla. Interestingly, these microbial changes coincided with high-titer MCMV replication in the colon, crypt hyperplasia, increased colonic pro-inflammatory cytokine levels, and a transient increase in the expression of the antimicrobial protein Regenerating islet-derived protein 3 gamma (Reg3γ). Further analyses revealed that murine and human intestinal epithelial cell lines, as well as primary intestinal crypt cells and organoids represent direct targets of CMV infection causing increased cell death. Accordingly, in vivo MCMV infection disrupted the intestinal epithelial barrier and increased apoptosis of intestinal epithelial cells. In summary, our data show that CMV transiently induces colitis in immunocompetent hosts by altering the intestinal homeostasis. 相似文献
46.
《Seminars in Pediatric Surgery》2022,31(3):151181
Advancements in donor management, organ preservation and operative techniques, as well as immunosuppressive therapies, have provided children with intestinal failure and its complications a chance not only for enteral autonomy but also long-term survival through intestinal transplantation (ITx). First described in the 1960’s, experience has grown in managing these complex patients both pre- and post-transplant. The goals of this review are to provide a brief history of intestinal transplantation and intestinal rehabilitation in pediatric patients, followed by focused discussions of the indications for ITx, induction and maintenance immunosuppression therapies, common post-operative complications, and outcomes/quality of life post-transplant. 相似文献
47.
48.
大蒜新素对人巨细胞病毒感染的人胚肺成纤维细胞凋亡的影响 总被引:2,自引:0,他引:2
目的 研究大蒜新素对人巨细胞病毒(HCMV)诱导感染的人胚肺成纤维细胞(HELF)凋亡的动态变化及凋亡调控基因bcl-2和fas mRNA表达的影响。方法 用流式细胞术测定HELF在高、低感染复数(MOI分别为2.5、0.25)HCMV感染后1、12、24、36、48、72、96h凋亡细胞比率;大、中、小剂量大蒜新素(9、6和3μg/mL)处理正常的和感染的HELF细胞(MOI为2.5)后上述各时间点凋亡细胞比率。用原位杂交法检测大剂量大蒜新素处理感染细胞(MIO为0.25)72h后bcl-2和fas mRNA表达强度变化,并与正常细胞和感染细胞对比分析。结果 正常细胞凋亡比率保持恒定低水平(凋亡率平均2.68%);低、高感染复数感染细胞随时间延长凋亡细胞逐渐增多,凋亡率峰值分别达8.85%(96h)和25.63%(72h);各剂量大蒜新素处理的正常细胞凋亡率增加,呈剂量依赖性,峰值分别为4.88%、6.47%和8.35%;但各剂量药物处理感染细胞后却使细胞凋亡比率下降,大剂量药物处理72h时效应最为明显,凋亡细胞比率由25.63%降至16.24%。正常细胞高表达bcl-2,低表达fas基因;感染HCMV后,bcl-2表达显著下调,fas表达明显增强;大蒜新素处理感染细胞后使bcl-2表达强度明显高于感染细胞,fas表达水平明显低于感染细胞,但仍未恢复到正常细胞水平。结论HCMV是HELF凋亡的强诱导剂;病毒可通过下调凋亡抑制基因bcl-2和上调凋亡促进基因fas而发挥致凋亡作用。大蒜新素本身可诱导HELF凋亡,但却能明显抑制HCMV诱导的细胞凋亡,其抑制作用可能与药物干扰HCMV影响凋亡调控基因bcl-2和fas表达有关。 相似文献
49.
Mycophenolate mofetil increases cytomegalovirus invasive organ disease in renal transplant patients 总被引:11,自引:0,他引:11
The impact of cytomegalovirus (CMV) infection post-transplantation is in part influenced by the degree of immunosuppression. While mycophenolate mofetil (MMF) does not increase the overall incidence of CMV infection, we have questioned whether or not it increases its severity. Using a case control study design in which 29 renal transplant patients developed CMV disease [17 (59%) of which received azathioprine (AZA) and 12 (41%) received MMF], increases in the frequency of organ involvement with CMV (58 vs. 18%; p = 0.03) and in the number of organs involved with CMV were noted in the MMF versus the AZA group (2.0 vs. 1.0; p = 0.015). These results indicate that the increased immunosuppressive activity of MMF impacts the morbidity of CMV infection, thus warranting the use of effective anti-CMV preventive regimens while patients are treated with MMF. 相似文献
50.
Chapenko S Folkmane I Tomsone V Amerika D Rozentals R Murovska M 《Clinical transplantation》2000,14(5):486-492
The ubiquity of human cytomegalovirus (CMV) and human herpesvirus-7 (HHV-7), as well as activation of these viruses during immunosuppression, allows the suggestion that both viruses could participate in the development of 'CMV disease' in patients after renal transplantation (RT). The aim of our research was to study the prevalence of latent CMV and HHV-7 infections in patients before RT, to determine interaction between these viruses in dual infection and possible association of their reactivation with the progression of 'CMV disease' after RT. Peripheral blood samples were collected from 49 patients before and up to 10-12 wk after RT. The methods used for diagnostics of viral infections were: serology, nested polymerase chain reaction (nPCR) analysis of peripheral blood leukocytes (PBL) and plasma, and virus isolation in cell cultures (morphological changes, nPCR analysis of cellular and cell-free samples, indirect immunofluorescence analysis). Before RT, CMV and HHV-7 DNAs were detected in PBL but not in the plasma samples, which indicates the presence of latent viral infection in patients. Latent dual (CMV + HHV-7) infection was prevalent (51.0%) in 49 patients, while CMV and HHV-7 infections alone were detected in 26.5 and 12.2% of patients, respectively. Risk of viral disease after RT, for recipients with latent dual infection before RT, was 12- and 2.2-fold higher in comparison with CMV and HHV-7 infections alone, respectively. Frequency of dual infection in 18 recipients with 'viral syndrome' or 'CMV disease' after RT was reliably higher (13/18, 81.3%) than CMV (1/18, 6.2%) (p < 0.025) and HHV-7 (2/18, 12.5%) (p < 0.025) infections alone. HHV-7 reactivation preceded CMV reactivation in 77.0% of the cases of dual infection in the recipients with viral disease and reactivation of both viruses preceded the development of viral disease. Severe 'CMV disease' developed in 2 out of 2 recipients with CMV primary infection and 'viral syndrome' in 1 recipient with CMV reinfection. The reactivation of CMV was detected in all recipients prior to onset of the disease. Correlation was shown between reactivation of latent HHV-7 infection and development of febrile syndrome in 2 out of 2 recipients with HHV-7 infection alone. Taking into account that dual infection is an increased risk factor for 'viral syndrome' and 'CMV disease' development, screening diagnostic should include testing for both viral infections in transplant donors as well as in recipients before and after RT. 相似文献