全文获取类型
收费全文 | 145551篇 |
免费 | 13926篇 |
国内免费 | 8178篇 |
专业分类
耳鼻咽喉 | 1185篇 |
儿科学 | 2406篇 |
妇产科学 | 763篇 |
基础医学 | 8351篇 |
口腔科学 | 2834篇 |
临床医学 | 17466篇 |
内科学 | 12358篇 |
皮肤病学 | 1573篇 |
神经病学 | 3000篇 |
特种医学 | 5114篇 |
外国民族医学 | 2篇 |
外科学 | 12770篇 |
综合类 | 40805篇 |
现状与发展 | 38篇 |
预防医学 | 18134篇 |
眼科学 | 1686篇 |
药学 | 18050篇 |
188篇 | |
中国医学 | 14430篇 |
肿瘤学 | 6502篇 |
出版年
2024年 | 709篇 |
2023年 | 1759篇 |
2022年 | 4448篇 |
2021年 | 5525篇 |
2020年 | 4992篇 |
2019年 | 2792篇 |
2018年 | 2815篇 |
2017年 | 3930篇 |
2016年 | 3007篇 |
2015年 | 5488篇 |
2014年 | 7441篇 |
2013年 | 9108篇 |
2012年 | 13081篇 |
2011年 | 13859篇 |
2010年 | 12909篇 |
2009年 | 11678篇 |
2008年 | 11858篇 |
2007年 | 11443篇 |
2006年 | 10320篇 |
2005年 | 8115篇 |
2004年 | 5905篇 |
2003年 | 4708篇 |
2002年 | 3618篇 |
2001年 | 3385篇 |
2000年 | 2461篇 |
1999年 | 865篇 |
1998年 | 198篇 |
1997年 | 206篇 |
1996年 | 191篇 |
1995年 | 124篇 |
1994年 | 134篇 |
1993年 | 106篇 |
1992年 | 56篇 |
1991年 | 47篇 |
1990年 | 50篇 |
1989年 | 39篇 |
1988年 | 22篇 |
1987年 | 34篇 |
1986年 | 25篇 |
1985年 | 24篇 |
1984年 | 16篇 |
1983年 | 25篇 |
1982年 | 22篇 |
1964年 | 6篇 |
1959年 | 15篇 |
1958年 | 19篇 |
1957年 | 14篇 |
1956年 | 7篇 |
1955年 | 7篇 |
1954年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
101.
雌激素受体亚型mRNA在子宫内膜癌组织中的表达 总被引:7,自引:0,他引:7
目的比较雌激素受体两种亚型α和β在子宫内膜癌中的表达,探讨雌激素受体亚型在子宫内膜癌发生和发展中的作用.方法用RT - PCR法检测子宫内膜癌和正常子宫内膜组织雌激素受体mRNA的表达.结果①与正常子宫内膜组织比较,子宫内膜癌中ER α mRNA、ER β mRNA表达和ER β/ER α mRNA比值都明显上升;②早期、内膜样子宫内膜癌ER α mRNA明显上升.结论子宫内膜癌的发生与ER α和ER β的表达有关,ER α mRNA表达升高可能提示子宫内膜癌预后较好. 相似文献
102.
子宫内膜癌中p16、E-cad mRNA表达的研究 总被引:1,自引:0,他引:1
目的 :探讨p16及E 钙粘附蛋白 (E cad)基因mRNA在子宫内膜癌中的表达及意义。方法 :采用RT PCR技术检测 3 0例子宫内膜癌及 8例正常子宫内膜组织的p16及E cadmRNA的表达。结果 :①子宫内膜癌p16mRNA的阳性表达明显低于正常子宫内膜 (P <0 .0 1) ,但p16mRNA的表达与子宫内膜癌的组织病理分级无关 ;②E cadmRNA在子宫内膜癌中呈低表达 ,正常组织内呈强阳性表达 ,二者差异非常显著 (P <0 .0 1) ,并且在子宫内膜癌中E cadmRNA的阳性表达与组织病理学分级呈负相关 (P <0 .0 5 )。结论 :p16、E cadmRNA的表达在子宫内膜癌的发生及进展过程中起重要作用 相似文献
103.
104.
Objective To explore the clinical significance of serum HGF level changes in gastric cancer pa-tients. Methods 60 cases of patients who operatied and clinicopathological confirmed gastric cancer, were detected serum HGF level by enzyme linked immunosorbent assay(ELISA) .40 cases were administered radical gastrectomy,20 cases of patients who had distant metastasis and loss operative chance were detected 7 days and 3 months preopera-tive,postoperative serum HGF level respectively. At the same time 40 cases of chronic gastritis patients and 40 cases of healthy examination people were selected as control group. Results Serum HGF level in patients with gastric canc-er was significantly higher than that of chronic gastritis and normal controls(P <0. 01). The serum HGF level of pa-tients with tumor vascular invasion significantly increased(P <0. 05). The patients with lymph node metastasis,serum HGF level was significantly higher than that patients with no lymph node metastasis(P <0. 05). The serum HGF level of patients with liver metastasis was significantly higher than that patients with no liver metastasis(P <0. 05). The se-rum HGF level of gastric cancer patients whose maximum diameter of the tumor ≥3cm were significantly higher than that maximum diameter of the tumor <3cm(P<0. 05). According to TNM staging of gastric cancer,the serum HGF level of Ⅰ phase and Ⅱ phase patients were significantly lower than that Ⅲ phase and Ⅳ phase patients(P <0.05).The serum HGF level of gastric cancer patients had no significant correlation with sex ,age and histological type(P <0.05). The serum HGF level of 40 cases of patients who were 1 week after surgery were significantly decreased,the patients who were 3 months after surgery were more obvious(P <0. 05 and P <0. 001). Conclusion HGF may play an important role in gastric cancer occurrence and development. The detection of serum HGF level can become an im-portant index for monitoring the degree of gastric cancer and prognosis of patients. 相似文献
105.
ZHANG Guang-Qin HAO Xue-Mei DAI De-Zai FU Yu ZHOU Pei-Ai WU Cai-Hong Research Division of Pharmacology China Pharmaceutical University Nanjing China ~National Laboratorv of Biomembrane Membrane Biotechnology College of Life Sciences Peking University Beijing China 《Acta pharmacologica Sinica》2003,(12)
AIM: To study the effect of puerarin (Pue) on Na~+ channel in rat ventricular myocytes. METHODS: Whole-cell patch-clamp technique was applied on isolated cardiomyocytes from rats. RESULTS: Pue inhibited cardiac I_(Na) in a positive rate-dependent and dose-dependent manner, with an IC_(50) of 349 μmol/L. The kinetics of blockage of cardiac sodium channel by Pue resembled the ClassIa/Ic of antiarrhythmic agents. Pue 300 μmol/L did not alter the shape of the I-V curve of I_(Na), but markedly shifted the steady-state inactivation curve of I_(Na) towards more negative potential by 15.9 mV, and postponed the recovery of I_(Na) inactivation state from (21.9±1.6) ms to (54.4±3.4) ms (P<0.01 ). It demonstrated that the steady state of inactivation was affected by Pue significantly. CONCLUSION: Pue protected ventricular myocytes against cardiac damage and arrhythmias by inhibiting recovery from inactivation of cardiac Na~+ channels. 相似文献
106.
Facilitating effect of histamine on spatial memory deficits induced by dizocilpine as evaluated by 8-arm radial maze in SD rats 总被引:3,自引:3,他引:3
HUANG Yu-Wen CHEN Zhong~ HU Wei-Wei ZHANG Li-San WU Wei YING Li-Yang WEI Er-Qing Department of Neurobiology Pharmacology School of Medicine Zhejiang University Hangzhou China 《Acta pharmacologica Sinica》2003,(12)
AIM: To investigate whether or not histamine is involved in spatial memory deficits induced by dizocilpine (MK-801) as evaluated by 8-arm radial maze of rats. METHODS: 8-Arm (4-arm baited) radial maze was used to measure spatial memory in rats. RESULTS: Bilaterally intrahippocampal (ih) injection of MK-801 (0.3 μg/site) impaired working memory and reference memory in rats. Both histamine (50, 100 ng/site, ih) and intraperitoneal (ip) injection of histidine (100, 200 mg/kg) markedly improved the spatial memory deficits induced by MK-801. On the other hand, the ameliorating effect of histidine (100 mg/kg, ip) was completely antagonized by α-fluoromethylhistidine (α-FMH, 5 μg/site, ih), a potent and selective histidine decarboxylase (HDC) inhibitor, and H_1-antagonist pyrilamine (1 μg/site, ih), but not by H_2-antagonist cimetidine, even at a high dose (2.5 μg/site, ih). CONCLUSION: The hippocampal histamine plays an important role in the ameliorating effect on MK-801-induced spatial memory deficits, 相似文献
107.
目的 :检测和分析“非典”患者康复出院半年后的免疫功能。方法 :对 2 8例“非典”康复者出院半年后外周血分别进行免疫功能 :免疫球蛋白、补体、T淋巴细胞亚群检测和分析。结果 :“非典”患者康复出院后 6个月后免疫功能免疫球蛋白、补体、T淋巴细胞亚群检测值和对照组比较差异均无显著性 (P >0 0 5 )。结论 :SARS患者出院 6个月后虽仍存在不同程度的免疫功能异常 ,但与正常对照组比较无显著性差异。其免疫功能异常的原因可能与疾病本身、有基础病及年龄高有关。 相似文献
109.
目的 :探讨结直肠癌组织中Survivin表达的临床病理学意义及其与癌细胞增殖的关系。方法 :免疫组织化学染色方法 (SP法 )检测 10 6例结直肠癌组织中Survivin、Ki 6 7、P5 3的表达 ,分析Survivin表达与Ki 6 7增殖指数、P5 3表达及各临床病理因素的关系。结果 :Survivin阳性表达结直肠癌的Ki 6 7增殖指数 (4 1.31%± 19.83% )明显高于Survivin阴性者 (2 6 .2 1%± 2 0 .36 % ) ,Survivin表达与肿瘤细胞增殖呈正相关 (P <0 .0 5 )。Survivin表达与P5 3表达无显著相关。Survivin在结直肠癌组织中的表达率为 6 4 .2 % (6 8/10 6例 ) ,癌旁形态学正常的结直肠粘膜未见Survivin表达 ;Survivin在中高分化结直肠癌表达阳性率 72 .4 % (6 3/87例 ) ,明显高于低分化结直肠癌 (2 6 .3% ,5 /19例 ) ,P <0 .0 5。此外 ,Survivin表达与患者性别、肿瘤位置、浸润深度、淋巴结转移、远处转移以及Dukes’分期无显著相关 (P >0 .0 5 )。结论 :凋亡抑制蛋白Survivin在结直肠癌组织中阳性表达率为 6 4 .2 % ,与细胞分化程度有关 ,可促进结直肠癌细胞的增殖 相似文献
110.
红细胞不仅可以运送氧、二氧化碳和清除循环免疫复合物,还能够识别、黏附、提呈肿瘤抗原,此外红细胞能够促进免疫细胞吞噬和杀伤肿瘤细胞的能力,因此红细胞在机体抗肿瘤免疫发挥重要作用。近年来,红细胞也可以开发作为药物载体治疗肿瘤,这与红细胞自身具有生物相容性和半透膜的特性有关。药物可以倍助渗透压梯度的不同、抗生素提高膜通透性,膜受体介导连接,以及交联介导连接等方法载入。已载入红细胞的药物半衰期延长,缓慢释放,受体液中酶等具有生物活性的物质降解,并且可以减轻药物毒副作用。缺点在于其靶向性单一。 相似文献