全文获取类型
收费全文 | 311360篇 |
免费 | 29035篇 |
国内免费 | 23722篇 |
专业分类
耳鼻咽喉 | 2439篇 |
儿科学 | 3272篇 |
妇产科学 | 3529篇 |
基础医学 | 36923篇 |
口腔科学 | 5074篇 |
临床医学 | 44454篇 |
内科学 | 44338篇 |
皮肤病学 | 2906篇 |
神经病学 | 16668篇 |
特种医学 | 11040篇 |
外国民族医学 | 217篇 |
外科学 | 28738篇 |
综合类 | 54479篇 |
现状与发展 | 77篇 |
一般理论 | 31篇 |
预防医学 | 20249篇 |
眼科学 | 9242篇 |
药学 | 34361篇 |
347篇 | |
中国医学 | 19338篇 |
肿瘤学 | 26395篇 |
出版年
2024年 | 1103篇 |
2023年 | 4919篇 |
2022年 | 12983篇 |
2021年 | 16183篇 |
2020年 | 12390篇 |
2019年 | 10487篇 |
2018年 | 11061篇 |
2017年 | 10031篇 |
2016年 | 9408篇 |
2015年 | 14342篇 |
2014年 | 17696篇 |
2013年 | 15271篇 |
2012年 | 22848篇 |
2011年 | 26060篇 |
2010年 | 16441篇 |
2009年 | 12918篇 |
2008年 | 16474篇 |
2007年 | 16313篇 |
2006年 | 16342篇 |
2005年 | 16262篇 |
2004年 | 9864篇 |
2003年 | 9101篇 |
2002年 | 7596篇 |
2001年 | 6658篇 |
2000年 | 7243篇 |
1999年 | 7994篇 |
1998年 | 5197篇 |
1997年 | 5214篇 |
1996年 | 3999篇 |
1995年 | 3790篇 |
1994年 | 3123篇 |
1993年 | 2122篇 |
1992年 | 2414篇 |
1991年 | 2007篇 |
1990年 | 1697篇 |
1989年 | 1462篇 |
1988年 | 1230篇 |
1987年 | 1106篇 |
1986年 | 831篇 |
1985年 | 675篇 |
1984年 | 407篇 |
1983年 | 243篇 |
1982年 | 139篇 |
1981年 | 156篇 |
1980年 | 103篇 |
1979年 | 109篇 |
1978年 | 25篇 |
1977年 | 16篇 |
1976年 | 12篇 |
1974年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
病理技术质量控制的探讨 总被引:2,自引:0,他引:2
病理技术是病理学诊断不可分割的一部分,正确的染色结果是病理诊断的重要依据之一.病理技术的规范与否,制片质量的好坏很大程度上影响病理医生作出正确的病理诊断. 相似文献
103.
104.
张金立 《河北职工医学院学报》2010,27(3):32-33
目的探讨臂丛加强化麻醉后颈部抽动的原因及防治。方法对近年来在麻醉方法、用药相同,术后颈部抽动患者的观察治疗过程进行分析。结果臂丛麻醉并发颈部抽动给予充分镇静后可完全治愈。结论麻醉后并发颈部抽动为药物副作用及颈局部刺激的综合作用。 相似文献
105.
目的探讨还原型谷胱甘肽(GSH)在预防糖尿病大鼠勃起功能障碍中的作用。方法通过腹腔注射链脲佐菌素65mg/kg建立糖尿病大鼠模型,然后随机分成DM组和DM+GSH组,DM+GSH组每天肌肉注射GSH200mg/kg。10周后观察大鼠勃起功能,并获取海绵体组织检测其谷胱甘肽、一氧化氮合酶(NOS)与丙二醛(MDA)水平,用TUNEL法检测细胞凋亡。结果成功建立糖尿病大鼠模型。与未注射GSH的DM组相比,DM+GSH组和正常对照组(C组)勃起功能更好,勃起率分别是20%,62.5%和100%。GSH水平DM+GSH组和C组明显比DM组高,其3组含量每克蛋白分别是(75.83±15.62)、(61.47±8.65)和(35.03±12.29)mg(P<0.05);NOS水平在DM+GSH组每毫克蛋白为(133.9±31.9)U,与正常对照组每毫克蛋白为(142.2±31.2)U相当,但较DM组每毫克蛋白为(58.4±18.9)U高(P<0.05);MDA含量在DM组每毫克蛋白为(3.71±0.62)nmol,明显高于正常对照组和DM+GSH组(P<0.05),这两组每毫克蛋白为(2.08±0.34)nmol和(2.44±0.28)nmol;细胞凋亡率在DM组、DM+GSH组和C组的分别是(22.6±3.6)%、(10.8±1.7)%和(7.2±2.1)%(P<0.05)。结论还原型谷胱甘肽对糖尿病大鼠阴茎组织有较好的抗氧化作用,能减少细胞凋亡,对延缓糖尿病性ED的发生有一定的作用。 相似文献
106.
目的 研究腹腔内注射三氧化二砷(arsenic trioxide,As2O3)对小鼠CO2气腹下肝癌H22转移的影响. 方法 昆明鼠40只(清洁级),中腹部穿刺置入1 mm套管针,自套管针注入1×106肿瘤细胞后,建立CO2气腹,压力8 mm Hg,时间30 min.术后随机分4组,每组10只,分别腹腔内注入生理盐水,1 ml;As2O3(2 mg/kg),1 ml;As2O3(4 mg/kg),1 ml;As2O3(4mg/kg)+肝素(10 U/ml),共1 ml.气腹后第3、7天测量肿瘤黏附因子(CD44)、血管内皮生长因子(vascular endothelial growth factor,VEGF)的变化;比较各组生存状态、腹围、体重变化及转移瘤直径.结果 气腹后第3、7天,与对照组相比,各As2O3组CD44、VEGF表达均明显降低(P<0.05).2个高剂量组的气腹后第3天VEGF、第7天CD44比低剂量组降低明显(P<0.05).4组戳口种植率分别为9/10、8/10、7/10、6/10,差异无显著性(x2=2.667,P=0.446). 结论 As2O3对CO2气腹腹腔镜肿瘤生长转移有抑制作用. 相似文献
107.
Christian J. Sauder Cheryl X. Zhang Malen A. Link W. Paul Duprex Kathryn M. Carbone Steven A. Rubin 《Vaccine》2009
The recent global resurgence of mumps has drawn attention to the continued need for robust mumps immunization programs. Unfortunately, some vaccines derived from inadequately attenuated vaccine strains of mumps virus have caused meningitis in vaccinees, leading to withdrawal of certain vaccine strains from the market, public resistance to vaccination, or in some cases, cessation of national mumps vaccination programs. The most widely implicated mumps vaccine in cases of postvaccination meningitis is derived from the Urabe AM9 strain, which remains in use in some countries. The Urabe AM9 vaccine virus has been shown to exhibit a considerable degree of nucleotide and amino acid heterogeneity. Some studies have specifically implicated variants containing a lysine residue at amino acid position 335 in the hemagglutinin-neuraminidase (HN) protein with neurotoxicity, whereas a glutamic acid residue at this position was associated with attenuation. To test this hypothesis we generated two modified Urabe AM9 cDNA clones coding either for a lysine or a glutamic acid at position 335 in the HN gene. The two viruses were rescued by reverse genetics and characterized in vitro and in vivo. Both viruses exhibited similar growth kinetics in neuronal and non-neuronal cell lines and were of similar neurotoxicity when tested in rats, suggesting that amino acid 335 is not a crucial determinant of Urabe AM9 growth or neurovirulence. 相似文献
108.
Susan W. Volk VMD PhD ; Antoneta Radu BS ; Liping Zhang MS ; Kenneth W. Liechty MD 《Wound repair and regeneration》2007,15(5):736-747
Chronic wounds create a formidable clinical problem resulting in considerable morbidity and healthcare expenditure. The etiology for wound healing impairment appears to be multifactorial; however, ischemia is a common factor in most types of chronic wounds. Ideal therapy for such wounds would be to correct deficiencies in growth factors and matrix components and provide cellular precursors required for timely wound closure. We hypothesized that stromal progenitor cell (SPC) therapy could correct the ischemic wound-healing defect through both direct and indirect mechanisms. To test this hypothesis, we used the ischemic rabbit ear model of chronic wound healing. We found that treatment of the wounds with SPCs was able to reverse the ischemic wound-healing impairment, with improved granulation tissue formation and reepithelialization compared with vehicle or bone marrow mononuclear cell controls. In vitro, SPCs were found to produce factors involved in angiogenesis and reepithelialization, and extracellular matrix components, providing evidence for both direct and indirect mechanisms for the observed correction of the healing impairment in these wounds. Treatment of ischemic wounds with SPCs can dramatically improve wound healing and provides a rationale for further studies focused on SPCs as a potential cellular therapy in impaired wound healing. 相似文献
109.
A CT-free, intra-operative planning and navigation system for minimally invasive anterior spinal surgery - an accuracy study. 总被引:1,自引:0,他引:1
B Maier G Zheng C Ploss X Zhang K Welle L-P Nolte I Marzi 《Computer aided surgery》2007,12(4):233-241
OBJECTIVE: A comprehensive study was performed to evaluate the accuracy of a newly developed CT-free, intra-operative planning and navigation system for anterior spine surgery. MATERIALS AND METHODS: Instruments and an image intensifier were tracked using the SurgiGATE navigation system. A laboratory study was performed on 27 plastic vertebrae. Fiducial markers were implanted in the vertebrae for accuracy evaluation purposes, and a dynamic reference base was placed on the vertebrae to establish a patient coordinate system (P-COS). Two fluoroscopic images were used for intra-operative planning. The graft bed plan was recorded in P-COS, followed by surgical formation of the graft bed, which was visualized. To evaluate the accuracy, the vertebrae were scanned with CT, and the markers were used to calculate an accurate paired-point registered transformation between the CT coordinate system and P-COS. RESULTS: Using the new SPO module, accurate planning and navigation of a resection of the vertebral body is possible using two fluoroscopic images. The overall mean error between the planned resection volume and the actual resection was 0.98 mm. In addition, the module can serve as an educational tool for training spine surgeons. CONCLUSIONS: The new fluoroscopy-based system can be used safely for accurate performance of anterior resection during spondylodesis. New methods for safe and accurate registration during anterior spine surgery need to be developed. 相似文献
110.
清开灵注射液治疗脑血管性痴呆32例 总被引:9,自引:0,他引:9
目的观察清开灵注射液治疗脑血管性痴呆的疗效.方法将中医学辨证属于实证的64例脑血管性痴呆患者随机分为治疗组(清开灵注射液组)和对照组(脑复康组),治疗5周后,将两组治疗前后在智力障碍程度、肢体功能、血液流变学指标、中医证型疗效方面的变化进行比较.结果经治疗后治疗组和对照组相比较,智力障碍程度变化(有效率、MMSE、ADL积分)、肌力、步行能力改变有显著性差异,p<0.05.而治疗前后组内及组间血流变指标虽有一定下降,但无统计学意义(p>0.05).结论清开灵注射液对脑血管性痴呆患者,在改善智力障碍、肌力、步行能力方面有较好的疗效. 相似文献