全文获取类型
收费全文 | 134848篇 |
免费 | 13651篇 |
国内免费 | 9240篇 |
专业分类
耳鼻咽喉 | 1038篇 |
儿科学 | 1856篇 |
妇产科学 | 1421篇 |
基础医学 | 12554篇 |
口腔科学 | 2570篇 |
临床医学 | 18896篇 |
内科学 | 16197篇 |
皮肤病学 | 1656篇 |
神经病学 | 4824篇 |
特种医学 | 4630篇 |
外国民族医学 | 44篇 |
外科学 | 10459篇 |
综合类 | 29607篇 |
现状与发展 | 40篇 |
一般理论 | 8篇 |
预防医学 | 12797篇 |
眼科学 | 3645篇 |
药学 | 15547篇 |
241篇 | |
中国医学 | 10886篇 |
肿瘤学 | 8823篇 |
出版年
2024年 | 548篇 |
2023年 | 2082篇 |
2022年 | 5270篇 |
2021年 | 6602篇 |
2020年 | 5428篇 |
2019年 | 4018篇 |
2018年 | 4091篇 |
2017年 | 4566篇 |
2016年 | 3825篇 |
2015年 | 6367篇 |
2014年 | 7824篇 |
2013年 | 8024篇 |
2012年 | 11994篇 |
2011年 | 12660篇 |
2010年 | 9729篇 |
2009年 | 8091篇 |
2008年 | 8876篇 |
2007年 | 8560篇 |
2006年 | 7565篇 |
2005年 | 6708篇 |
2004年 | 4483篇 |
2003年 | 4130篇 |
2002年 | 3370篇 |
2001年 | 2625篇 |
2000年 | 2223篇 |
1999年 | 1720篇 |
1998年 | 1002篇 |
1997年 | 1032篇 |
1996年 | 760篇 |
1995年 | 665篇 |
1994年 | 607篇 |
1993年 | 352篇 |
1992年 | 344篇 |
1991年 | 320篇 |
1990年 | 277篇 |
1989年 | 219篇 |
1988年 | 213篇 |
1987年 | 187篇 |
1986年 | 122篇 |
1985年 | 94篇 |
1984年 | 46篇 |
1983年 | 44篇 |
1982年 | 18篇 |
1981年 | 14篇 |
1980年 | 8篇 |
1979年 | 17篇 |
1978年 | 2篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1973年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
BACKGROUND: It is known that intravenous anesthetic etomidate fat emulsion has cerebral protection. Now many scholars focus on the research of its cerebral protection from molecular biology, but the mechanism of cerebral protection is still fully unclear.
OBJECTIVE: To observe the influence of etomidate fat emulsion on the [Ca2+]i in hippocampal neurons during the transient cerebral ischemia injury in rats.
DESIGN: Randomized controlled observation.
SETTING: Weifang Medical College.
MATERIALS: This study was carried out in the functional laboratory of Weifang Medical College between October 2005 and March 2006. Twenty-four male healthy Wistar rats, aged 3 to 4 months, were involved. Etomidate fat emulsion was provided by the limited company of En-hua Medical Bloc in Jiangsu Province (code of H20020511) and the other agents and materials were provided by Laboratory Center of Weifang Medical College.
METHODS: The 24 Wistar rats were randomized into 3 groups: sham-operation group, model group and etomidate preconditioning group, with 8 rats in each. Rat models of transient cerebral ischemia injury were made by the ligation of bilateral carotid arteries combined with descending blood pressure in the latter two groups. Before ischemia (ligation of bilateral common carotid artery), rats in the etomidate preconditioning group were intraperitoneally injected with 12 mg/kg etomidate fat emulsion and then persistently intraperitoneally injected with etomidate fat emulsion at 1.0 mg/kg per minute. Rats in the model group were not administrated. Rats in the sham-operation group were only performed bilateral common carotid artery isolation. When rats were modeled, their brain tissues were quickly taken out and detected.
MAIN OUTCOME MEASURES: Change of the fluorescence pixel value of the [Ca2+]i in each group by the laser scanning confocal microscope.
RESULTS: Twenty-four rats were involved in the final analysis. Fluorescence pixel value in the sham-operation group was in the low level. Fluorescence pixel value in the model group was significantly higher than that in the sham-operation group (P < 0.01). Fluorescence pixel value in the etomidate preconditioning group was significantly lower than that in the model group (P < 0.01).
CONCLUSION: The protection of etomidate fat emulsion to the transient cerebral ischemic injury in rats is associated with the inhibition to the increase of [Ca2+]i to some extent. 相似文献
92.
LIU Yixin FU Yan 《世界急危重病医学杂志》2005,2(6):990-991
【论文特点介绍】本研究观察了CRP是否可以作为肾动脉粥样硬化狭窄(ARAs)的独立危险因子。通过对危险因素进行多变量Logistic回归分析,结果表明年龄、冠脉病变严重程度、外周血管疾病是ARAS的独立危险因素,而CRP水平、高血压、高脂血症、肾功能不全并非ARAS的独立危险因素。 相似文献
93.
目的: 几乎没有研究报道妊娠高血压综合征 (妊高征 ) 患者尿蛋白对新生儿出生体重的影响, 该研究欲探讨妊高征患者不同水平尿蛋白对新生儿出生体重的影响关系。方法: 1997年 1月 ~2004年 6月期间, 住院分娩患中、重度妊高征产妇 136例, 对新生儿出生体重与各种因素进行回归分析及t检验分析。结果: 单变量回归分析尿蛋白、孕龄分别与新生儿出生体重有高度显著性关系 (P<0. 01); 尿蛋白和孕龄一起进入多元回归分析, 校正影响因素, 尿蛋白和孕龄仍然是影响新生儿出生体重显著性因素 (P<0 .01); 与妊高征尿蛋白 ( +) 比较, 尿蛋白 无显著性影响新生儿出生体重 (P>0. 05), 尿蛋白 有显著性影响新生儿出生体重 (P<0. 01)。结论: 新生儿出生体重与妊高征患者尿蛋白丢失有关, 尿蛋白 丢失将严重影响新生儿出生体重。 相似文献
94.
To study the pathological and histochemical characteristics of lesions in piglet livers infected with Taenia saginata asiatica (T. saginata asiatica) throughout the different stages, piglets were fed with eggs of T. saginata asiatica and raised in isolation in an animal center to establish the T. saginata asiatica infection model with normal piglets as control. The pathological changes in the piglet livers were observed after the infection
using liver sections stained with hematoxylin and eosin. Histochemical methods were used to check the changes in lipid, glycogen
and protein content in the liver. The data collected by image analysis were analyzed statistically with Statistical Package
for the Social Science. The results show that T. saginata asiatica-exposed piglets were indeed infected. Inflammatory reactions began on the fourth day and progressed rapidly. Kupffer cell
hyperplasia, hepatic hydropic degeneration and ballooning degeneration were found in the 10th–20th days after infection. Hepatic
central veins and hepatic sinusoids were dilated and congested. Spotty necrosis occurred in some local liver tissues. In the
40th–60th days, granulomatous reactions and mild hepatocirrhosis were the main lesions. In the 70th–80th days, hepatocirrhosis
and bile duct proliferation were observed in the liver. In the different stages, lipid drops were increased while glycogen
and protein levels were decreased to some degree. There was a significant difference in metabolism between the infected group
and the control group (P < 0.01). It is concluded that pigs are the favorable intermediate host of T. saginata asiatica and its infection can result in serious pathological and histochemical lesions in host organs.
Translated from Journal of Guiyang Medical College, 2006, 31(4): 296–300 [译自: 贵阳医学院学报] 相似文献
95.
目的 探讨发作性睡病与HLA—DQB1基因的相关性。方法 对30例发作性睡病患者的临床资料进行分析。用序列特异性引物-聚合酶链反应(PCR-SSP)分型技术测定HLA—DQB1等位基因,并与44例健康人检测的数据进行比较。结果 发作性睡病患者组DQB1*0602基因频率为40%,与正常对照组9.09%相比较明显增高;未检出DQB1*0401—0402基因,与正常对照组9.09%相比较,经统计学分析,差异有显著性(P〈0.05)。结论 HLA—DQB1*0602基因为中国发作性睡病人群的易感基因;HLA-DQB1*0401—0402基因为中国发作性睡病人群的保护基因。 相似文献
96.
牙本质黏结剂增强根管倒充填材料密闭性能的实验研究 总被引:2,自引:1,他引:1
目的观察在使用MTA进行根尖倒封闭术时,牙本质粘结剂对其密闭抗微渗漏的影响.方法取40颗离体单根恒牙,分别用MTA、MTA 牙本质粘结剂进行根尖倒封闭术,用染料渗透法检测根尖微渗漏的情况.结果MTA 牙本质粘结剂组的根尖密闭效果明显优于单纯使用MTA组,其差别具有统计意义(P<0.05).结论在使用MTA进行根尖倒封闭术时,使用牙本质粘结剂可提高充填体的密闭效果. 相似文献
97.
目的探讨口腔鳞状细胞癌颈淋巴转移范围和临床病理因素间的关系。方法对26例已存在颈淋巴转移的原发口腔癌患者,进行颈淋巴转移范围和患者的临床病理资料的统计分析,寻找影响转移范围的主要因素。结果单因素分析发现,肿瘤生长方式和分化程度与转移范围相关。多因素分析显示,肿瘤生长方式(浸润型)和肿瘤转移范围相关。结论对颈淋巴已有转移的口腔癌患者,若原发灶为浸润性生长,肿瘤倾向于更大范围的转移。对已有颈淋巴转移的口腔癌患者,颈淋巴清扫术范围的制定,主要考虑肿瘤生长方式,适当考虑肿瘤发病部位、厚度、大小和细胞的分化程度,可以不考虑患者年龄和性别。 相似文献
98.
目的:探讨细胞活素肿瘤坏死因子-α(TNF-α)、SNAP(S-Nitroso-Nacetyl-penicillamine)对胰腺癌细胞产生血管内皮生长因子A、C(VEGF-A、C)的调节.方法:用Northern杂交和Western杂交法分析6种人胰腺癌细胞株中VEGF-A、C基因和蛋白的表达;以TNF-α或SNAP刺激其中两个细胞株后用逆转录-聚合酶链式反应技术(RT-PCR)分析其VEGF-A、C基因的表达.结果:Northern杂交法显示这6种胰腺癌细胞株均有4.1kb VEGF-A基因和2.4kb VEGF-C基因的表达;Western杂交法显示它们均有分子量为43kD的VEGF-A蛋白质和分子量为55kD的VEGF-C蛋白质的表达.RT-PCR分析法显示:TNF-α使细胞株COLO-357产生VEGF-A、VEGF-C mRNA分别减少约1~2.5倍、1~2倍,使细胞株CAPAN-1产生VEGF-A、VEGF-C mRNA分别减少约1倍、1.6~2.5倍;而SNAP刺激细胞株COLO-357产生VEGF-A mRNA增加约5倍,刺激细胞株CAPAN-1产生VEGF-A mRNA增加约4倍,但对这两种细胞株产生VEGF-C mRNA均无明显刺激作用.结论:细胞活素TNF-α和低氧通过调节血管内皮生长因子A、C的表达而影响胰腺癌细胞的生物学特性,抑制癌细胞的增殖,促进其凋亡、死亡或进展、恶化. 相似文献
99.
100.
Lijun Di Jun Ren Ying Yan 《中德临床肿瘤学杂志》2007,6(4):393-395
Objective: To evaluate the effect and safety of clinical use of zoledronic acid in the treatment of malignant hypercalcemia. Methods: A multi-center, open phase II clinical trial was conducted in 15 cases with malignant hypercalcemia who received zoledronic acid intravenously for 15 min. The level of blood calcium and side effects were recorded regularly within 28 days after injection. Results: One case was dropped out due to bad compliance. The complete response rate (the corrected serum calcium was reduced to normal level) was 100.00% (14/14). The medium time of complete response rate was 5.07 days. The medium maintain time was 22.30 days. Slight, or moderate fever was observed. Conclusion: Zoledronic acid can effectively reduce the malignant hypercalcemia. The use of zoledronic acid appears to be safety and convenient. 相似文献