全文获取类型
收费全文 | 20398篇 |
免费 | 1212篇 |
国内免费 | 518篇 |
专业分类
耳鼻咽喉 | 85篇 |
儿科学 | 318篇 |
妇产科学 | 230篇 |
基础医学 | 4966篇 |
口腔科学 | 419篇 |
临床医学 | 1195篇 |
内科学 | 2439篇 |
皮肤病学 | 442篇 |
神经病学 | 804篇 |
特种医学 | 244篇 |
外国民族医学 | 4篇 |
外科学 | 1553篇 |
综合类 | 3288篇 |
预防医学 | 1026篇 |
眼科学 | 187篇 |
药学 | 2375篇 |
7篇 | |
中国医学 | 1422篇 |
肿瘤学 | 1124篇 |
出版年
2024年 | 57篇 |
2023年 | 273篇 |
2022年 | 458篇 |
2021年 | 681篇 |
2020年 | 733篇 |
2019年 | 580篇 |
2018年 | 520篇 |
2017年 | 649篇 |
2016年 | 645篇 |
2015年 | 699篇 |
2014年 | 1224篇 |
2013年 | 1555篇 |
2012年 | 1225篇 |
2011年 | 1506篇 |
2010年 | 1214篇 |
2009年 | 1247篇 |
2008年 | 1125篇 |
2007年 | 1045篇 |
2006年 | 946篇 |
2005年 | 718篇 |
2004年 | 671篇 |
2003年 | 607篇 |
2002年 | 463篇 |
2001年 | 350篇 |
2000年 | 359篇 |
1999年 | 310篇 |
1998年 | 352篇 |
1997年 | 251篇 |
1996年 | 271篇 |
1995年 | 256篇 |
1994年 | 246篇 |
1993年 | 182篇 |
1992年 | 149篇 |
1991年 | 111篇 |
1990年 | 64篇 |
1989年 | 54篇 |
1988年 | 30篇 |
1987年 | 11篇 |
1986年 | 11篇 |
1985年 | 61篇 |
1984年 | 48篇 |
1983年 | 26篇 |
1982年 | 23篇 |
1981年 | 22篇 |
1980年 | 13篇 |
1979年 | 15篇 |
1978年 | 19篇 |
1977年 | 13篇 |
1975年 | 15篇 |
1973年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
Hypereosinophilic syndrome in Hodgkin's disease with increased granulocyte-macrophage colony-stimulating factor 总被引:2,自引:0,他引:2
We report a patient with eosinophilia accompanied by Hodgkin's disease who showed remarkable increase in granulocyte-macrophage colony-stimulating factor (GM-CSF) in plasma but no increase in interleukin-5 (IL-5). The plasma GM-CSF level normalized as eosinophilia and lymphadenopathy disappeared after chemotherapy. Immunohistochemical study with immunoperoxidase staining technique showed a positive stain in lymph node cells by monoclonal anti-GM-CSF antibody. Eosinophilia is often accompanied by Hodgkin's disease, and several cases have been reported to show high levels of plasma IL-5. To our knowledge, this is the first report to show a high level of plasma GM-CSF in Hodgkin's disease with eosinophilia. 相似文献
33.
应用APAAP法对15例肺癌TIL部分膜抗原的表达动态进行了免疫组化分析。结果显示:未经激活的TIL细胞,其膜抗原(CD~+3,CD~+4,CD~+8)的表达动态基本恒定,经IL-2激活的TIL细胞体外培养一段时期后,其CD~+3细胞数明显上升,同时CD~+8的表达逐渐减少,而CD~+4的表达在培养后期明显增多。 相似文献
34.
Detection of cytoplasmic IL-1 beta in peripheral blood mononuclear cells from intensive care unit (ICU) patients. 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Clinical and experimental immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Cytokines including IL-1 beta have been implicated in the pathophysiology of sepsis and the systemic inflammatory response. It is believed that certain critically ill patients may be 'primed' with respect to cytokine production, and that subsequent 'triggers' may cause exaggerated cytokine production in these patients with exacerbation of their clinical condition; however, no means of identifying 'primed' patients has been described. The presence of cytoplasmic IL-1 beta within peripheral blood mononuclear cells (PBMC) from patients in the ICU was investigated as a means of identifying 'primed' patients, using fluorescent antibody labelling and flow cytometry. The study revealed that PBMC from ICU patients had a different staining pattern for IL-1 beta than those from healthy subjects, and that PBMC from certain ICU patients did indeed stain strongly for IL-1 beta; however, the presence of these strongly staining cells was not associated with clinical condition or outcome. It is concluded that whilst it might be possible to identify 'primed' patients in the ICU using this technique, this is of no clinical value as a predictor of clinical course. 相似文献
35.
MASAAKI KATO MD NAOFUMI KAJIMURA MD MASANORI SEKIMOTO MD TSUYOSHI WATANABE MD KIYOHISA TAKAHASHI MD 《Psychiatry and clinical neurosciences》1998,52(2):262-263
Abstract We tried melatonin treatment in two patients with non-24 h sleep-wake syndrome, who did not respond to treatments by vitamin B12 , bright light therapy, or hypnotics. In one patient, melatonin 5–10 mg improved difficulty in falling asleep and in waking, although it failed to improve the sleep-wake rhythm. In another patient, melatonin 3 mg successfully changed the sleep-wake rhythm from free-running pattern to delayed sleep phase pattern. However, melatonin re-administration after a 4-month drug-free interval failed to improve his free-running sleep-wake rhythm. These results suggest that melatonin acted as a sleep inducer in one patient and as a phase setter in the other, although the effect on the latter patient was transient. 相似文献
36.
J. B. Payne R. A. Reinhardt M. P. Masada L. M. DuBois A. C. Allison 《Journal of periodontal research》1993,28(6):451-453
Gingival crevicular fluid (GCF) IL-8 and IL-1,1β levels were determined by sandwich enzyme-linked immunosorbent assays. Associations between IL-8 and IL-1β GCF levels, and between these cytokines and patient estrogen status were evaluated. IL-8 and IL-1β were detected more frequently and in higher amounts/30 s GCF sample in estrogen-deficient patients than in estrogensufficient patients. IL-8 and IL-1β GCF levels were significantly correlated. These lindings suggest that GCF IL-8 levels are associated with patient estrogen status and local IL-1β concentrations. 相似文献
37.
目的研究IFN-γ,IL-4水平对血透患者外周血淋巴细胞(PBLC)凋亡调控蛋白Fas,Bcl-2表达的影响.方法采用流式细胞术的间接免疫荧光素标记法和双抗体夹心ELISA法,分别检测30例HD患者PBLC Fas,Bcl-2的表达水平和血清IFN-γ,IL-4水平.结果H-D患者血清IFN-γ水平明显低于健康对照组,IL-4浓度显著高于对照组(P均<0.01);其外周血PBLC的Fas表达水平明显高于健康对照组,而Bcl-2水平则明显低于健康对照组(P均<0.01).经相关分析发现:Fas表达水平与血清IFN-γ水平呈负相关,而与血清IL-4水平呈正相关(P均<0.01);Bcl-2表达水平与血清IFN-γ水平呈正相关,而与血清IL-4水平呈负相关(P均<0.01).结论HD患者PBLC存在异常凋亡现象;并与Th1型细胞因子分泌低下,以及TTh2型细胞因子分泌增加之间有一定的相关性,上述改变可能在HD患者的免疫功能紊乱中起着重要作用. 相似文献
38.
Effects of mycophenolic acid on IL-6 expression of human renal proximal and distal tubular cells in vitro. 总被引:1,自引:0,他引:1
BACKGROUND: Interleukin-6 (IL-6) is a multifunctional cytokine which regulates immune responses and host defence mechanisms. IL-6 has been found to be increased in certain inflammatory conditions of the kidney, in which tubular epithelial cells play a pivotal role. Human renal tubular cells express IL-6. Until now no data about the effect of the immunosuppressant drug mycophenolic acid (MPA) on IL-6 expression were available. METHODS: Proximal and distal tubular epithelial cells (PTC/DTC) have been isolated immunomagnetically. Confluent monolayers were stimulated with interleukin-1beta (IL-1beta; 25 U/ml), IL-1beta+ MPA (0.25-50 micro M) or MPA alone for 48 h. Release of IL-6 protein into the supernatant was evaluated with an enzyme immunoassay, IL-6 mRNA expression was evaluated using the Quantikine mRNA kit. RESULTS: After IL-1beta stimulation, a highly significant 2.6- (PTC) and 3.8-fold (DTC) upregulation of IL-6 expression was detectable. IL-6 mRNA was upregulated by IL-1beta [1.57- (PTC) and 2.03-fold (DTC)]. MPA inhibited this cytokine-induced IL-6 expression in a dose-dependent manner. Incubation with the lowest MPA concentration had no effect on the stimulated upregulation, whereas all higher doses significantly decreased IL-6 expression. Dexamethasone significantly inhibited the cytokine-induced IL-6 protein release in PTC, but not in DTC. CONCLUSIONS: In this study we demonstrated for the first time an inhibitory effect of MPA on the stimulated IL-6 expression of renal tubular epithelial cells. In contrast to older data, which showed a synergistic upregulation of the expression of a CC-chemokine by a combination of cytokines and MPA, in the present study we could demonstrate an immunosuppressive effect of MPA on the expression of an important cytokine. 相似文献
39.
人膀胱癌T24细胞及其SCID小鼠移植瘤组织中KDR的表达 总被引:1,自引:1,他引:0
目的 检测KDR在人膀胱癌T24细胞及其SCID小鼠移植瘤组织中的表达。方法 常规培养T24细胞,建立荷人膀胱癌移植瘤SCID小鼠动物模型,使用抗KDR单克隆抗体,通过免疫荧光、免疫组化检测KDR在T24细胞及瘤体组织上的表达;结果 KDR在T24细胞及瘤体组织中均呈阳性表达。结论 本研究结果为进一步研究抗KDR单抗在荷T24细胞移植瘤动物体内分布及对瘤体生长的抑制效应奠定了实验基础。 相似文献
40.
Early multiple organ dysfunction syndrome appears to be facilitated with bacterial translocation in severely burn injury, yet the mechanisms of bacterial translocation remains in dispute. The aim of this study was to investigate the potential role of intestinal bifidobacteria in the pathogenesis of gut-derived bacteria/endotoxin translocation following burns and the effects of bifidobacterial supplement on gut barrier. Methods: Wistar rats were randomly divided into burn group (Burn, n=60),sham burn group (SB, n=10) in experiment Ⅰ , and burn + saline group (BS, n=30), burn + bifidobacteria group (BB, n=30), and sham-burn + saline group (SS, n= 10) in experiment Ⅱ. Animals in BB group were fed bifidobacterial preparation (5 × 109 CFU/ml) after burns, 1.5ml,twice daily. Animals in BS and SS were fed saline. Samples were taken on days 1, 3, and 5 in burn groups, and on day 3 in sham-burn groups. The incidence of bacteria/endotoxin translocation and counts of Bifidobacterium, Fungi and Escherichia coli in gut mucosa were determined with standard methods. The levels of sIgA in mucus of small intestine were measured by RIA. The positive sIgA expression in lamina propria and ileum mucosal injury was evaluated light microscopically by blinded examiners. Results: Our results showed that the incidence of bacterial translocation was increased after burns, which was accompanied by significant decrease in number of bifidobacteria but significant increase in E. coli and fungi in gut mucosa, and elevation of levels of plasma endotoxin and IL-6 (P<0. 001).The incidence of bacterial translocation was markedly reduced after 3- and 5-day supplementation of bifidobacteria compared with control group (P<0.05). The counts of mucosal bifidobacteria were increased by 4- to 40-fold,while E. coli and fungi were decreased by 2- to 30-fold and 10- to 150-fold, respectively, after bifidobacterial supplementation in contrast to control group. The damage of mucosa tended to be less pronounced after 3-day bifidobacteria-supplemented formula compared with control group [grade 2(0-6) vs. grade 4(3-6), P<0.05]. Moreover, the expression and release of sIgA was markedly augmented after 3-day bifidobacteria-supplementation formula and it returned to normal range on day 5. Conclusion: The decrease in counts and proportion of bifidobacteria in mucous membrane flora may play an important role in the development of bacteria/endotoxin translocation following thermal injury. The supplement of exogenous bifidobacteria could per se improve gut barriers, and attenuate bacteria/endotoxin translocation secondary to major burns. 相似文献