全文获取类型
收费全文 | 92925篇 |
免费 | 9071篇 |
国内免费 | 5400篇 |
专业分类
耳鼻咽喉 | 975篇 |
儿科学 | 1388篇 |
妇产科学 | 789篇 |
基础医学 | 7096篇 |
口腔科学 | 1572篇 |
临床医学 | 10671篇 |
内科学 | 10300篇 |
皮肤病学 | 949篇 |
神经病学 | 3252篇 |
特种医学 | 3641篇 |
外国民族医学 | 12篇 |
外科学 | 9740篇 |
综合类 | 21988篇 |
现状与发展 | 29篇 |
一般理论 | 4篇 |
预防医学 | 9331篇 |
眼科学 | 1489篇 |
药学 | 10477篇 |
119篇 | |
中国医学 | 8486篇 |
肿瘤学 | 5088篇 |
出版年
2024年 | 420篇 |
2023年 | 1299篇 |
2022年 | 3217篇 |
2021年 | 4272篇 |
2020年 | 3500篇 |
2019年 | 2292篇 |
2018年 | 2371篇 |
2017年 | 2715篇 |
2016年 | 2298篇 |
2015年 | 4128篇 |
2014年 | 5062篇 |
2013年 | 6103篇 |
2012年 | 8761篇 |
2011年 | 9172篇 |
2010年 | 7523篇 |
2009年 | 6385篇 |
2008年 | 6771篇 |
2007年 | 6282篇 |
2006年 | 5573篇 |
2005年 | 4431篇 |
2004年 | 3310篇 |
2003年 | 2852篇 |
2002年 | 2197篇 |
2001年 | 1604篇 |
2000年 | 1259篇 |
1999年 | 651篇 |
1998年 | 290篇 |
1997年 | 271篇 |
1996年 | 258篇 |
1995年 | 238篇 |
1994年 | 175篇 |
1993年 | 125篇 |
1992年 | 130篇 |
1991年 | 139篇 |
1990年 | 120篇 |
1989年 | 101篇 |
1988年 | 87篇 |
1987年 | 84篇 |
1986年 | 75篇 |
1985年 | 76篇 |
1984年 | 79篇 |
1983年 | 56篇 |
1982年 | 56篇 |
1981年 | 51篇 |
1980年 | 49篇 |
1979年 | 45篇 |
1978年 | 47篇 |
1975年 | 39篇 |
1974年 | 39篇 |
1973年 | 36篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Objective To elucidate the effect of FasL gene expression on the proliferation and apoptosis of hypoxic rectal carcinoma cells. Methods The normoxic expression level of FasL in HR-8348 subtype cells (HR-8348B, HR-8348L, HR-8348F and HR-8348As) with different invasive power were verified by Western blot. Hypoxia models for HR-8348B, HR-8348L, HR-8348F and HR-8348As were constructed with chemical modeling, then the FasL levels in all groups at 12 h after hypoxia were quantitated by Western blot. Distribution of different cell life cycles was determined with flow cytometry. Cell reproductive activities were detected with MTT method, and cell apoptesis was assessed with TUNEL. Results FasL protein was pigmentized at the position of 40 000 by Western blot, and the expression level of FasL was significantly higher in HR-8348F cells than those in HR-8348B, HR-8348L and HR-8348As cells(F=361.149, P<0.01) in normoxia. At 12 h after hypoxia, the FasL level was also significantly higher in HR-8348F cells than those in other groups (F=278.766, P<0.01), but was not markedly different as compared to themselves in normoxia (t=1.762, P>0.05). The proliferation index was significantly higher in HR-8348F (60.43±3.72) than those in HR-8348B (40.01±3.30), HR-8348L (41.30±4.06) and HR-8348As cells (35.87±4.39), respectively (F=39.477, P<0.01). However, both inhibition rate of proliferation and apoptotic index were remarkably lower in HR-8348F (17.30±1.98 and 13.10±1.04) than those in HR-834B (33.70±4.33 and 21.60±1.31), HR-8348L (34.20±3.92 and 20.10±1.15), and HR-8348As (38.00±4.55 and 23.90±1.23), respectively (F=28.811 and 76.462, respectively, P<0.01). Conclusion The expression enhancement of intracellular FasL in rectal carcinoma in hypoxia can lead to accelerated proliferation and reduced apeptosis of cells, which will promote tumor cells to adapt microenvironmental hypoxia. 相似文献
32.
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
33.
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
34.
We report a case of extragastrointestinal stromal tumor possibly originating from the prostate. The patient underwent radical prostatectomy because of no metastatic evidence. No recurrence and metastasis have been found during 14 months of follow up. To our knowledge, this may be the third such case published in a report in terms of pathological type. 相似文献
35.
新生儿期卵巢增大,可形成卵巢囊肿、影响卵巢进入正常位置而形成腹股沟疝,导致小儿性早熟,影响小儿身高及心理发育等。自2006年1月-6月我们连续发现5例新生儿卵巢增大,予以报道。1材料与方法临床资料见表1,应用彩色多普勒超声诊断仪:Philps HD、HDI 5000,高频探头7-10mmHz。行常规下腹部及腹股沟、会阴区扫查。2结果超声检查所见及诊断结果见表1。表1 5例临床资料与超声检查结果比较异及丘脑-垂体-卵巢器质性病变产生过多激素,刺激胎儿卵巢内卵泡增生过大、内液潴溜,是导致卵巢增大的原因[3]。5例新生儿8枚卵巢增大的原因分析,说明胎儿期… 相似文献
36.
目的探讨乳头溢液的渗断和治疗方法,为合理的治疗提供科学依据。方法回顾分析手术治疗的207例乳头溢液病例资料。结果(1)在非哺乳期间发生乳头溢液多属病理性溢液;(2)通过美蓝法或平针头指示法行区段切除术,安全准确。结论(1)乳头溢液特别足血性溢液应手术治疗.对早期发现和早期治疗乳腺癌有鼋要的临床意义。(2)乳头溢液伴肿块者,不沧年龄大小、溢液性质均应手术治疗。 相似文献
37.
试论七情发生和脑主神明与抑郁症病机证治的关系 总被引:8,自引:0,他引:8
抑郁症是一组以抑郁心境自我体验为中心的临床症状群或状态.中医多将其归在郁证之类,对其理论解释的重点多是在心主神明论指导下的以五脏为中心的肝,临床治疗亦多遵疏肝解郁这一基本大法,并取得了一定成效. 相似文献
38.
Patricia K P Burnell Lars Asking Lars Borgstr?m Steve C Nichols Bo Olsson David Prime Ian Shrubb 《Journal of aerosol medicine》2007,20(3):269-281
Magnetic resonance imaging (MRI) of the oropharyngeal region from 20 adult volunteers using four model inhalation devices (varying mouthpiece diameters, airflow resistances) and tidal breathing was carried out. Statistical analysis (convex hull method) selected 12 scans from 80 data sets representing the extremes of all dimensions in the population. Twelve physical mouth-throat models were made by stereolithography using the exact scan data. The aim was to produce models with varying dimensions to span the adult population, and to investigate if oropharyngeal dimensions affected throat retention for different delivery systems. In an in vitro analysis, the models were used to determine the retention effect of the oropharyngeal airspaces when drug aerosols were administered from four inhalation delivery systems: a pressurised metered dose inhaler (pMDI), two different dry powder inhalers (DPIs A and B), and a nebulizer. The aims of this work were to determine the key parameters governing mouth-throat retention and whether retention was dependent on the delivery system used. Characterizing the throat models by measuring 51 different dimensional variables enabled determination of the most influential variables for dose retention for each inhalation delivery system. Throat model retention was found to be dependent on the delivery system (pMDI approximately DPI(A) > DPI(B) > Neb.). The most influential variable was the total throat model volume. Throat models representing high, median, and low oropharyngeal filtration in healthy adults have been identified. 相似文献
39.
自体表皮细胞培养与异体真皮组合应用研究 总被引:13,自引:0,他引:13
严重烧伤病人皮肤修复中主要未解决的问题是真皮的替代。动物实验结果表明,异体皮移植后5天,用自体培养表皮细胞膜片覆盖真皮床,14天后复合皮成活率是84.6%±2.4%。组织学检查证实表皮已形成了复层结构,可见基底层、颗粒层和角质层。临床应用中,异体皮移植后10天,去除异体表皮覆盖病人的自体培养表皮,35天后未见排斥征象,异体真皮促进了培养表皮的分层、成熟和完整,组织学检查证实表皮细胞的边缘清楚,已分化形成颗粒层和角质层,真皮多细胞,已血管化,但表皮嵴缺乏。 相似文献
40.