全文获取类型
收费全文 | 48499篇 |
免费 | 4287篇 |
国内免费 | 3714篇 |
专业分类
耳鼻咽喉 | 455篇 |
儿科学 | 419篇 |
妇产科学 | 471篇 |
基础医学 | 5510篇 |
口腔科学 | 663篇 |
临床医学 | 6345篇 |
内科学 | 6840篇 |
皮肤病学 | 459篇 |
神经病学 | 2468篇 |
特种医学 | 1642篇 |
外国民族医学 | 24篇 |
外科学 | 5250篇 |
综合类 | 9354篇 |
现状与发展 | 6篇 |
一般理论 | 1篇 |
预防医学 | 3028篇 |
眼科学 | 1419篇 |
药学 | 5510篇 |
44篇 | |
中国医学 | 2751篇 |
肿瘤学 | 3841篇 |
出版年
2024年 | 154篇 |
2023年 | 718篇 |
2022年 | 1961篇 |
2021年 | 2274篇 |
2020年 | 1767篇 |
2019年 | 1432篇 |
2018年 | 1502篇 |
2017年 | 1483篇 |
2016年 | 1399篇 |
2015年 | 2161篇 |
2014年 | 2619篇 |
2013年 | 2478篇 |
2012年 | 3779篇 |
2011年 | 3719篇 |
2010年 | 2535篇 |
2009年 | 1999篇 |
2008年 | 2529篇 |
2007年 | 2579篇 |
2006年 | 2675篇 |
2005年 | 2445篇 |
2004年 | 1889篇 |
2003年 | 1949篇 |
2002年 | 1685篇 |
2001年 | 1384篇 |
2000年 | 1334篇 |
1999年 | 1243篇 |
1998年 | 718篇 |
1997年 | 698篇 |
1996年 | 502篇 |
1995年 | 493篇 |
1994年 | 425篇 |
1993年 | 254篇 |
1992年 | 301篇 |
1991年 | 281篇 |
1990年 | 227篇 |
1989年 | 199篇 |
1988年 | 156篇 |
1987年 | 171篇 |
1986年 | 121篇 |
1985年 | 87篇 |
1984年 | 62篇 |
1983年 | 43篇 |
1982年 | 25篇 |
1981年 | 22篇 |
1980年 | 10篇 |
1979年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
胸腰椎骨折术后内固定松动、断裂的原因及预防 总被引:14,自引:3,他引:11
目的 探讨椎弓根螺钉系统用于胸腰椎骨折术后出现松动、断裂的原因,并提出相应的预防对策。方法 12例胸腰椎骨折术后内固定失效病例,采用RF系统3例,AF系统9例。均未行植骨融合,AF系统中未按要求安装横连结3例,术后伤椎前缘高度平均恢复至正常的85.2%。结果 术后8—21个月出现棒断裂4例,螺钉断裂3例,钉帽松动5例。结论 内固定物的自身问题、术者的经验欠缺及操作不规范是胸腰椎骨折术后椎弓根螺钉系统松动、断裂的原因,但伤椎骨结构未能得到良好重建及术后椎间盘退变可能是其更重要的因素。因此重视内固定物的选择、加强规范操作,强调对损伤椎体及椎间盘的全面处理是预防内固定失效的有效措施。 相似文献
52.
Association of the expressions of platelet-derived growth factor receptor and c-Fos with the biological characteristics of bladder cancer. 总被引:1,自引:0,他引:1
OBJECTIVE: To elucidate the relation of platelet-derived growth factor receptor (PDGFR) and c-Fos protein expressions with human bladder transitional epithelial cell carcinoma (BTCC). METHODS: The expressions of PDGFR and c-Fos were investigated in 11 normal bladder tissue samples, 14 adjacent non-carcinoma tissues and 43 BTCC tissues by means of SP immunohistochemical technique. RESULTS: The c-Fos expression was found in the cell nuclei and cytoplasm, and PDGFR in the nuclear membrane, cytoplasm, and cellular membrane. PDGFR and c-Fos were detected in 81.40% and 48.83% of the BTCC tissues respectively, at the rates both significantly higher than those in normal and adjacent non-carcinoma tissues (P<0.05). Correlation between the expression of c-Fos and the tumor grading was noted (P<0.05). The expressions of PDGFR and c-Fos in tumor blood vessels were significantly higher than those in normal vessels. CONCLUSIONS: The expressions of PDGFR and c-Fos might be involved in the development of BTCC, possibly related to the angiogenesis of the tumors. c-Fos expression can indicated the cell proliferative status of the BTCC. 相似文献
53.
一种具有高信噪比的脉搏波光电传感器的研制 总被引:5,自引:0,他引:5
目的:探讨研制一种生理信号光电传感器。方法:利用光电传感器检测通过指端毛细血管后的光强度的变化,将光信号转换成电信号,再经过电信号1/V转换、放大、滤波处理。结果:获得了清晰稳定的指端容积脉搏波。结论:高信噪比的光电传感器可用作于临床监测和生理信号分析处理系统。 相似文献
54.
甲醛固定源同种异体骨移植材料的体外实验研究 总被引:5,自引:0,他引:5
Yun-tao Lu Lin Yuan Pei-feng Jiao Lei Yu Xiao-zhong Qiu Li-sheng Zhang Shi-zhen Zhong 《第一军医大学学报》2004,24(1):27-31
OBJECTIVE: To conduct an in vitro study to assess the preliminary possibility of using formalin-fixed, instead of fresh, human bone tissues for allografting. METHODS: Fresh cadaveric bone tissues were fixed by formalin for more than 6 months and dissected into 5 mmx5 mmx5 mm pieces and 5 mmx5 mmx40 mm sticks, followed by chemical treatments to prepare the allograft bone materials. When alls treatments were completed, the bone grafts were centrifuged and their properties and cellular compatibility assessed in comparison with the currently used bone grafts clinically. RESULTS: The residual formaldehyde of the fixed allograft bone material was much below the controlled level and no significant differences were noted between the bone graft materials tested in regard to the chemical and mechanical properties and biocompatibility. CONCLUSION: This material we have prepared may meet the clinical demands for bone grafting, with good biocompatibility and less chance for infection by pathological agents. 相似文献
55.
Zhong Q. Wang Audrey D. Bell-Farrow William Sonntag William T. Cefalu 《Experimental gerontology》1997,32(6):E966-684
We report on the effect of age and chronic caloric restriction (CR) on insulin binding and glucose transporter content in both diaphragm and heart muscle membrane of young (11 months), mid-age (17 months), and old (29 month) ad libitum fed and CR Brown-Norway rats. The control animals received rat chow ad lib and CR animals were allowed 60% of ad libitum food. The CR regimen was initiated at four months of age and the animals were maintained on their respective diets until necropsy. There was no effect of age on insulin binding for either ad libitum or CR animals at each age evaluated. Caloric restriction significantly lowered insulin levels at each age studied when compared to the ad libitum-fed rats. However, CR animals were noted to have increased insulin binding (p < 0.001) compared to ad libitum-fed animals at each age for diaphragm muscle. For the heart, there appeared to be a decreased binding, particularly at higher insulin concentrations, in CR-fed animals. There was no net change in Glut-1 or Glut-4 levels for heart muscle membrane, or Glut-4 levels for diaphragm muscle membrane between ad libitum or CR animals. This data indicates that caloric restriction may have tissue-specific effects for insulin receptor binding, and that the improved insulin sensitivity in CR states is not a result of altered glucose transporter protein content. 相似文献
56.
研究补肾抗衰口服液对大鼠衰老模型免疫器官胸腺和脾脏的影响.结果显示,模型组大鼠胸腺和脾脏重量减轻,胸腺重/体重比值、脾重/体重比值减小,胸腺组织学观察,显示萎缩改变;药物组大鼠胸腺和脾脏重量、胸腺重/体重、脾重/体重比值接近正常对照组,胸腺组织学观察,未显示萎缩改变.本研究结果表明,补肾抗衰口服液能延缓胸腺和脾脏萎缩,保护机体的正常免疫功能,提示该药有抗衰老的作用. 相似文献
57.
本文应用日本血吸虫虫卵单克隆抗体及虫卵可溶性抗原,分别致敏新型免疫微球载体重氮基聚苯乙烯乳胶,制备出血吸虫反向乳凝试剂与乳凝试剂,并用于检测血吸虫病患者血清标本中的相应抗原和相应抗体,以此试验检测197份急慢性血吸虫病患者血清标本。结果反向乳凝试剂检出率为90.4%,乳凝试剂检出率为95.2%,均高于反向间接血凝法的85.0%。反向乳凝试验与乳凝试验联合应用,既可早期诊断,又可判断疗效。试验采用玻片凝集法,3min内即出结果,方法敏感.特异、简便和快速。 相似文献
58.
对173例支气管哮喘特异性脱敏治疗的疗效及影响疗效的因素进行了分析。结果表明:显效为30.6%(53/173).有效为56.1%(97/173),无效为13.3%(23/173)。影响疗效的因素与病情的程度有关,而与年龄、病程、皮试阳性反应强弱及脱敏治疗前4个疗程内是否应用曲安缩松等无关。并对特异性脱敏治疗支气管哮喘的优缺点进行讨论。 相似文献
59.
60.
备用根大鼠脊髓后角提取液中神经营养活性组分的分离及生物活性测定 总被引:1,自引:0,他引:1
制作备用根大鼠脊髓后角提取液,取其分子量大于10kD的组分进行SDS-聚丙烯酰胺凝胶电泳分析,发现手术侧和非手术侧的电泳区带数目大致相同,但手术侧样品的第四条蛋白质区带扫描的吸收峰面积百分比大于非手术侧样品的第四条区带,两者在量上可能有差别。将手术侧样品经交联葡聚精G-75凝胶层析,得到两个洗脱峰.第一峰洗脱液有促进体外培养的背根节神经元存活及其突起生长的作用,其电泳分析显示4条主带,分子量在40~80kD之间.实验结果提示部分去传入纤维支配的脊髓后角组织含有神经营养活性物质,该物质的分子量约在40~78kD之间. 相似文献