全文获取类型
收费全文 | 143786篇 |
免费 | 13781篇 |
国内免费 | 8537篇 |
专业分类
耳鼻咽喉 | 1100篇 |
儿科学 | 1824篇 |
妇产科学 | 1578篇 |
基础医学 | 21464篇 |
口腔科学 | 2513篇 |
临床医学 | 17302篇 |
内科学 | 20081篇 |
皮肤病学 | 1573篇 |
神经病学 | 7010篇 |
特种医学 | 4940篇 |
外国民族医学 | 65篇 |
外科学 | 13736篇 |
综合类 | 23429篇 |
现状与发展 | 29篇 |
一般理论 | 12篇 |
预防医学 | 10106篇 |
眼科学 | 3468篇 |
药学 | 16568篇 |
121篇 | |
中国医学 | 7839篇 |
肿瘤学 | 11346篇 |
出版年
2024年 | 570篇 |
2023年 | 2240篇 |
2022年 | 5752篇 |
2021年 | 7269篇 |
2020年 | 5306篇 |
2019年 | 4738篇 |
2018年 | 4965篇 |
2017年 | 4554篇 |
2016年 | 4345篇 |
2015年 | 6317篇 |
2014年 | 7821篇 |
2013年 | 7591篇 |
2012年 | 10638篇 |
2011年 | 11279篇 |
2010年 | 7919篇 |
2009年 | 6388篇 |
2008年 | 7707篇 |
2007年 | 7709篇 |
2006年 | 7010篇 |
2005年 | 6346篇 |
2004年 | 4954篇 |
2003年 | 4830篇 |
2002年 | 4117篇 |
2001年 | 3423篇 |
2000年 | 2950篇 |
1999年 | 2619篇 |
1998年 | 1663篇 |
1997年 | 1788篇 |
1996年 | 1250篇 |
1995年 | 1192篇 |
1994年 | 1083篇 |
1993年 | 764篇 |
1992年 | 966篇 |
1991年 | 884篇 |
1990年 | 789篇 |
1989年 | 726篇 |
1988年 | 652篇 |
1987年 | 562篇 |
1986年 | 528篇 |
1985年 | 424篇 |
1984年 | 369篇 |
1983年 | 302篇 |
1982年 | 268篇 |
1981年 | 229篇 |
1980年 | 196篇 |
1979年 | 198篇 |
1978年 | 192篇 |
1977年 | 211篇 |
1976年 | 191篇 |
1974年 | 156篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
A. U. Ziganshin J. Yu. Falou V. A. Mamedov L. V. Mustakimova 《Pharmaceutical Chemistry Journal》2005,39(6):303-307
The ability of 12 new thiazole derivatives to influence the muscle contractility mediated by purine P2X receptors has been
studied in vitro using isolated tissues of rats and guinea pigs. Most of the synthesized compounds did not cause significant effects, but
two compounds exhibited pronounced antagonism with respect to P2X-mediated contractility response. These compounds offer a
good starting point for the synthesis of new effective antagonists of P2 receptors.
__________
Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 39, No. 6, pp. 22 – 25, June, 2005. 相似文献
102.
Namita Wagle Nha Nam Do Jack Yu James L. Borke 《American journal of orthodontics and dentofacial orthopedics》2005,127(6):655-661
BACKGROUND: The periodontal ligament (PDL) is a soft tissue interposed between the tooth and the alveolar bone. It is responsible for transmission of forces in vivo; this promotes bone remodeling. The purpose our study was to use fractal analysis to quantify the complex morphology of the PDL-bone interface. METHODS: We used Scion Image (Scion Corp, Frederick, Md) and Benoit fractal analysis (Tru Soft International, St. Petersburg, Fla) programs to calculate the fractal dimension of the PDL-bone interface in rats via the box-counting method. Rats in the experimental groups received an initial force of 0.1N or 0.5N with customized springs for 6 hours. RESULTS: Our studies showed an increase in normal fractal dimension at the root apices of the rats' maxillary molars. We also found evidence that the fractal dimension varies along the entire root length from the apex to the cementoenamel junction. CONCLUSIONS: Mechanical loading might lead to an increase in fractal dimension at the PDL-bone interface apart from mechanisms of bone cell directed remodeling. These changes in fractal dimension are proportional to loading and could provide a new parameter for force determination in orthodontic tooth movement. 相似文献
103.
104.
D Yu 《中华耳鼻咽喉科杂志》1989,24(4):215-8, 254-5
Kanamycin (400 mg/kg) was injected daily for 5 days in guinea pigs, the changes in CM and AP responses were recorded. The CM threshold was elevated in 34.5% of the animals and the CM amplitude was reduced when compared with normal animals (P less than 0.005). The AP threshold was elevated in 13.8%. The latency of N1 was increased (P less than 0.001) and the amplitude of N1 reduced at 80 dB (S-L) (P less than 0.001).cAMP and cGMP levels in the organ of Corti and stria vascularis spiral ligament decreased, and the decrease correlated with the changes in auditory function. We consider the reduction of cyclic nucleotides in the cochlea may be important in kanamycin ototoxicity. 相似文献
105.
106.
目的 :观察氧雾化吸入备劳特和爱喘乐治疗儿童哮喘急性发作的疗效。方法 :选择 15 8例哮喘急性发作患儿作为研究对象 ,分为观察组和对照组。观察组采用氧驱动雾化吸入备劳特和爱喘乐 ;对照组静脉滴注氨茶碱和地塞米松。结果 :观察组显效率 87.3% (96 /110 ) ,总有效率 99.1% (10 9/110 ) ,临床治愈率 94 .5 % (10 4 /110 ) ;对照组显效率 2 2 .9% (11/48) ,总有效率 6 0 .4 % (2 9/48) ,临床治愈率 5 4 .2 % (2 6 /48)。观察组显效率、总有效率及临床治愈率皆显著高于对照组 ,差异有高度统计意义 (P <0 .0 1)。观察组治疗后心率较治疗前明显下降 ,差异有统计意义(P <0 .0 5 )。结论 :采用氧驱动雾化吸入备劳特和爱喘乐能快速、有效地控制哮喘发作。 相似文献
107.
Neal M. Blitz DPM FACFAS Jonathan H. Yu BS 《The Journal of foot and ankle surgery》2005,44(3):218-221
Freiberg's infraction is an ostechondrosis of a lesser metatarsal head resulting in degeneration of the metatarsophalangeal joint. Several mechanisms have been suggested in its pathenogenesis. Freiberg first described the entity and believed single impact trauma was the underlying cause. Repetitive biomechanical microtrauma is the most widely accepted etiologic theory. Other factors contributing to its development include aseptic necrosis, ischemia, and a congenital predisposition. We present a case report of Freiberg's infraction occurring in identical twins involving multiple metatarsals in various stages of degeneration. One of the twins was affected unilaterally whereas the other twin was affected bilaterally. Both twins had involvement of the second metatarsal on the same side extremity. The occurrence of Freiberg's infraction in identical twins suggests that an underlying congenital predisposition to the condition may play more of a role than previously considered. 相似文献
108.
神经化组织工程骨构建的初步观察 总被引:16,自引:0,他引:16
目的评估两种组织工程骨体内神经化重建方法的成骨效果,研究神经化与成骨的相互关系。方法26只新西兰大白兔,其中24只随机分成四组:组织工程骨组(A组),感觉神经束植入组(B组),运动神经束植入组(C组),血管束植入组(D组);另2只为空白对照组。每只动物均制备左侧股骨长1.5cm的段缺性骨与骨膜缺损,钢板固定后骨缺损处分别植入用四种方法制备的组织工程骨。植入的神经分别是隐神经和股神经肌支。术后4、8、12周摄股骨正位X线片,用放射影像学评分和X线阻射影分析比较骨缺损修复情况。结果在组织工程骨中植入感觉神经束后,比单纯组织工程骨和运动神经束植入的修复效果均有明显提高,而在组织工程骨中植入运动神经束与单纯组织工程骨修复骨缺损的效果相比较无明显差异,感觉神经束植入与血管束植入的成骨效果比较无明显差异,血管束植入组的成骨效果优于其它两组。结论利用感觉神经束植入的方法可以提高组织工程骨的成骨作用,而植入运动神经束却无此作用。 相似文献
109.
Objective Sstudy effect of nuclear factor-κB ASOND on I type collagen expression and rat hepatic stellate cells(HSC)proliferation.Methods Rat HSCs were separated by affusing and digestingof Ⅳ type collagenenzyme and density acentric method.Lipid-mediated NF-κB p65 ASOND(0.001,0.01,0.1,1μmol/L)Was transferred into rat HSCs.Toxicity of HSCs caused by NF-κB p65 ASOND and activity of LDH were determined by trypan blue staining.Proliferation affection of transferring NF-κB p65 ASOND into HSCs was determined by MTT.In different concentration NF-κB p65 ASOND.expression of Ⅰ type collagen stimulated by 1mg/L TNF-αwas determined by RT-PCR and ELISA.Results After transfection of NF-κB p65 ASODN,expression of NF-κB protein in HSCs was decreasing.Toxicity experiment indicated that NF-κB p65 ASOND of different concentration(0.001,0.01,0.1 and 1.0 μmol/L)had no effect on HSCs livability and LDH activity(P<0.05).Four different concentration NF-κ B p65 ASOND could restrain HSCs proliferation stimulated by 1 mg/L TNF-α.The expression of I type collagen and mRNA stimulated by 1mg/LTNF-αwas increased,and had a positive correlation with concentration(P>0.05).Conclusion NF-κB p65 ASOND may depress NF-κB activity to restrain HSCs proliferation and Ⅰ type collagen expression,and reduce extracellular matrix. 相似文献
110.
目的探讨低功率半导体激光对急慢性关节损伤的治疗作用.方法1999年至2004年急慢性关节损伤的患者240例,随机分为两组,各120例,激光组采用低功率半导体激光治疗仪照射痛点;对照组口服活血止痛胶囊,外用沈阳红药膏治疗.结果两周后的疗效比较.激光组有效率为85.0%,痊愈率为44.2%;对照组有效率为71.7%,痊愈率为20.8%;差异有显著意义.激光组中,急性关节损伤的患者痊愈率为52.9%,慢性关节损伤患者的痊愈率为32.7%,差异有显著意义(P<0.05)有效率,差异无显著性意义.结论低功率半导体激光对急慢性关节损伤,尤其是急性小关节损伤有很好的疗效. 相似文献