全文获取类型
收费全文 | 67886篇 |
免费 | 5310篇 |
国内免费 | 1899篇 |
专业分类
耳鼻咽喉 | 324篇 |
儿科学 | 2747篇 |
妇产科学 | 3190篇 |
基础医学 | 9748篇 |
口腔科学 | 1209篇 |
临床医学 | 5027篇 |
内科学 | 9150篇 |
皮肤病学 | 1030篇 |
神经病学 | 5090篇 |
特种医学 | 1060篇 |
外国民族医学 | 6篇 |
外科学 | 5695篇 |
综合类 | 8847篇 |
现状与发展 | 5篇 |
一般理论 | 3篇 |
预防医学 | 4963篇 |
眼科学 | 772篇 |
药学 | 8897篇 |
19篇 | |
中国医学 | 3105篇 |
肿瘤学 | 4208篇 |
出版年
2024年 | 165篇 |
2023年 | 1215篇 |
2022年 | 2757篇 |
2021年 | 2987篇 |
2020年 | 2462篇 |
2019年 | 2631篇 |
2018年 | 2605篇 |
2017年 | 2507篇 |
2016年 | 2237篇 |
2015年 | 2298篇 |
2014年 | 3868篇 |
2013年 | 4433篇 |
2012年 | 3421篇 |
2011年 | 4122篇 |
2010年 | 3253篇 |
2009年 | 3220篇 |
2008年 | 3224篇 |
2007年 | 3002篇 |
2006年 | 2914篇 |
2005年 | 2611篇 |
2004年 | 2313篇 |
2003年 | 2002篇 |
2002年 | 1608篇 |
2001年 | 1270篇 |
2000年 | 1212篇 |
1999年 | 1015篇 |
1998年 | 866篇 |
1997年 | 816篇 |
1996年 | 717篇 |
1995年 | 685篇 |
1994年 | 553篇 |
1993年 | 493篇 |
1992年 | 389篇 |
1991年 | 393篇 |
1990年 | 317篇 |
1989年 | 277篇 |
1988年 | 321篇 |
1987年 | 232篇 |
1986年 | 243篇 |
1985年 | 434篇 |
1984年 | 438篇 |
1983年 | 334篇 |
1982年 | 402篇 |
1981年 | 320篇 |
1980年 | 288篇 |
1979年 | 245篇 |
1978年 | 195篇 |
1977年 | 145篇 |
1976年 | 162篇 |
1975年 | 146篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
目的探讨血液透滤清除IL-6在重症急性胰腺炎治疗中的作用及机理。方法根据诊断标准对2002年7月至2006年6月来我院就诊的178例重症急性胰腺炎患者随机分组:血滤组(HF组)85人,非血滤组(NHF组)93人。比较两组患者局部和全身表现,观察各时相点促炎细胞因子血清IL-6的测定值的差异。结果HF组与NHF组比较:腹痛腹胀持续时间为(18.8±4.2)hvs(89.7±28.1)h(P〈0.05);治疗后第10天APACHEⅡ积分为(5.5±3.6)分vs(13.8±3.8)分(P〈0.05);住院天数和医疗费为(28.2±12.4)天vs(42.4±11.2)天和(4.38±2.8)万元vs(7.46±2.2)万元,(P〈0.05)。治疗后各时相点血清IL-6检测结果:HF组较NHF组显著降低(P〈0.05);MODS发病率和病死率分别为12.47%vs.36.28%和4.28%vs.12.82%,两者差异有统计学显著意义(P〈0.05)。结论早期短时血滤有利于纠正重症急性胰腺炎患者血清促炎细胞因子过度释放,使病情减轻,降低MODS发病率和病死率,提高疗效。 相似文献
92.
P. Muiesan W. Jassem R. Girlanda R. Steinberg H. Vilca-Melendez G. Mieli-Vergani A. Dhawan M. Rela N. Heaton 《American journal of transplantation》2006,6(5P1):1012-1016
We report our experience of pediatric liver transplantation with partial grafts from non-heart beating donors (NHBD). Controlled donors less than 40 years of age with a warm ischemia time (WI) of less than 30 min were considered for pediatric recipients. Death was declared 5 min after asystole. A super-rapid recovery technique with aortic and portal perfusion was utilized. Mean donor age was 29 years and WI 14.6 min (range 11–18). Seven children, mean age 4.9 years (0.7–11), median weight 20 kg (8.4–53) received NHBD segmental liver grafts. Diagnoses included seronegative hepatitis, neonatal sclerosing cholangitis, familial intrahepatic cholestasis, hepatoblastoma, primary hyperoxaluria and factor VII deficiency (n = 2).The grafts included four reduced and one split left lateral segments, one left lobe and one right auxiliary graft. Mean cold ischemia was 7.3 h (6.2–8.8). Complications included one pleural effusion and one biliary collection drained percutaneously. At 20 months (10–36) follow-up all children are alive and well with functioning grafts.
Donation after cardiac death is a significant source of liver grafts for adults and children with careful donor selection and short cold ischemic times. 相似文献
Donation after cardiac death is a significant source of liver grafts for adults and children with careful donor selection and short cold ischemic times. 相似文献
93.
CD44v6、P27蛋白在乳腺癌组织中的表达及意义 总被引:3,自引:0,他引:3
目的 探讨乳腺癌中CD44v6、p27蛋白表达的意义。方法 应用免疫组化S-P法检测65例乳腺癌中CD44v6、p27蛋白表达。结果 65例乳腺癌中CD44v6、p27蛋白表达总阳性率分别为58.4%、38.4%。CD44v6蛋白阳性表达率与乳腺癌组织学类型、腋淋巴结转移呈正相关(P<0.05,P<0.01),与预后呈负相关(P<0.01),与组织学分级无明显相关性(P>0.05);p27蛋白阳性表达与乳腺癌组织学类型、组织学分级及腋淋巴结转移呈负相关(P<0.05),与预后呈正相关(P<0.05)。结论 CD44v6、p27蛋白表达与乳腺癌浸润、转移及预后显著相关,检测乳腺癌中CD44v6、p27蛋白表达水平,对判断乳腺癌恶性程度、复发转移潜能,评估患者预后及术后选择合理治疗方案有一定参考价值。 相似文献
94.
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
95.
Masahiko Tomiyama Fumiaki Mori Tamaki Kimura Noritaka Ichinohe Koichi Wakabayashi Muneo Matsunaga Masayuki Baba 《Neuropathology》2004,24(4):290-295
The medial globus pallidus plays a crucial role in generation of L‐DOPA‐induced dyskinesia in patients with Parkinson's disease. The 6‐hydroxydopamine‐lesioned rat exhibiting behavioral sensitization to L‐DOPA is one useful animal model for examining L‐DOPA‐induced dyskinesia. To determine neuropathological abnormality responsible for behavioral sensitization, the medial globus pallidus and the substantia nigra reticulata in 6‐hydroxydopamine‐lesioned rats treated with L‐DOPA were examined. Intermittent L‐DOPA treatment induced hypertrophy of the lesioned‐side of medial globus pallidus and substantia nigra reticulata of 6‐hydroxydopamine‐lesioned rats with behavioral sensitization to L‐DOPA. Additionally, coadministration of a 5‐HT1A receptor agonist, 8‐hydroxy‐2(di‐n‐propylamino)tetralin with L‐DOPA, alleviated the hypertrophy with improvement of the behavioral sensitization. These results suggest that hypertrophy of the medial globus pallidus and substantia nigra reticulata is associated with induction of behavioral sensitization to L‐DOPA in 6‐hydroxydopamine‐lesioned rats. Therefore, neuropathological changes corresponding to hypertrophy might underlie L‐DOPA‐induced dyskinesia in patients with Parkinson's disease. 相似文献
96.
97.
98.
99.
Xinyu D. Li Esperanza Arias Ramamohana R. Jonnala Shyamala Mruthinti Jerry J. Buccafusco 《Journal of molecular neuroscience : MN》1996,27(3):325-336
The ability of nicotine to induce a cytoprotective or neuroprotective action occurs through several down-stream mechanisms.
One possibility is that the drug increases the expression of tyrosine kinase A (TrkA) nerve growth factor (NGF) receptors.
Certain β-amyloid peptides (e.g., Aβ1–42) have been shown to bind with high affinity to α7 nicotinic receptors and thus interfere
with a potentially neurotrophic influence. Treatment of differentiated PC-12 cells with nicotine produced a concentration-dependent
increase in cell-surface TrkA receptors that occurred concomitantly with cytoprotection. The effect of nicotine was blocked
by either of the α7 receptor antagonists α-bungarotoxin (α-BTX) or methyllycaconatine. The cytoprotective action of nicotine
also was inhibited by pretreatment with 10–100 nM Aβ1–42. Nicotine also was administered (four injections of 30 μg, spaced evenly over 24 h) to rats by direct injection into
a lateral cerebral ventricle. Brain TrkA expression was increased significantly in hippocampus and entorhinal cortex (up to
32% above control), with no changes found in cerebral cortex or hypothalamus. The nicotine-induced increases in TrKA expression
in hippocampus and entorhinal cortex were significantly inhibited by 10 μg α-BTX or by 10 nmol Aβ1–42. Therefore, physiologically
relevant concentrations of Aβ1–42 can prevent nicotine-induced TrkA receptor expression in brain regions containing cholinergic
neurons susceptible to the neurotoxicity associated with Alzheimer’s disease. 相似文献
100.
The effect of Panaxatriol Ginsenoside (PTGS) on Immune functions in bone marrow suppressed mice induced by injection of cyclophosphamide (CY) has been studied. Bone marrow suppressed mice were made by injection of CY (150 mg/kg) parenterally. Subcutaneous injection of PTGS three days earlier partially restored the number and the activity of bone marrow cells, significantly enhanced the production of IL-1, IL- 3 and IL- 6 like substances and promoted the reactivity of murlne spleen cells to Con-A In bone marrow suppressed mice. 相似文献