全文获取类型
收费全文 | 9282篇 |
免费 | 650篇 |
国内免费 | 462篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 102篇 |
妇产科学 | 151篇 |
基础医学 | 524篇 |
口腔科学 | 855篇 |
临床医学 | 755篇 |
内科学 | 1205篇 |
皮肤病学 | 35篇 |
神经病学 | 220篇 |
特种医学 | 264篇 |
外科学 | 704篇 |
综合类 | 1358篇 |
预防医学 | 408篇 |
眼科学 | 33篇 |
药学 | 2438篇 |
9篇 | |
中国医学 | 1149篇 |
肿瘤学 | 165篇 |
出版年
2024年 | 18篇 |
2023年 | 179篇 |
2022年 | 289篇 |
2021年 | 326篇 |
2020年 | 318篇 |
2019年 | 313篇 |
2018年 | 308篇 |
2017年 | 233篇 |
2016年 | 262篇 |
2015年 | 268篇 |
2014年 | 598篇 |
2013年 | 686篇 |
2012年 | 655篇 |
2011年 | 691篇 |
2010年 | 558篇 |
2009年 | 466篇 |
2008年 | 476篇 |
2007年 | 521篇 |
2006年 | 497篇 |
2005年 | 417篇 |
2004年 | 324篇 |
2003年 | 291篇 |
2002年 | 202篇 |
2001年 | 195篇 |
2000年 | 148篇 |
1999年 | 122篇 |
1998年 | 95篇 |
1997年 | 91篇 |
1996年 | 107篇 |
1995年 | 97篇 |
1994年 | 80篇 |
1993年 | 80篇 |
1992年 | 59篇 |
1991年 | 58篇 |
1990年 | 41篇 |
1989年 | 51篇 |
1988年 | 31篇 |
1987年 | 39篇 |
1986年 | 24篇 |
1985年 | 37篇 |
1984年 | 21篇 |
1983年 | 22篇 |
1982年 | 24篇 |
1981年 | 16篇 |
1980年 | 17篇 |
1979年 | 8篇 |
1978年 | 7篇 |
1977年 | 10篇 |
1976年 | 9篇 |
1974年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
41.
课题研究提供了改良的人精子染色体直接制备,G显带核分析技术。在对80例对象的人精子染色体直接制备,G显带核型分析中,成功率为62.5%,较Templado方法的成功率(58.1%)进一步提高。通过对正常人,不育,流产对象的男性精子染色体研究,发现精子染色体数目和结构畸变率分别为:正常人2.3%和0%,不育14.0%和4.8%,流产组4.5%和2.4%,不育和流产组的畸变率较正常人增加。在对5例染色 相似文献
42.
? The benefits of informing patients before undergoing surgery or other investigative procedures are clearly demonstrated in the literature. ? This study aimed to determine the amount and type of information given to patients before, during and after undergoing gastroscopy investigations. ? A survey approach incorporating structured interviews and structured observation was utilized. ? There were statistically significant differences between the information acquired by younger and older patients prior to, but not during or after, the procedure. ? Nurses appear to be the most important source of information for older patients while the information leaflet was perceived as the most important source of information for younger patients. 相似文献
43.
将一种快速、灵敏、可靠、简便的抗癌活性微量测定技术——~3H—TdR前体掺入技术用于复方中药抗癌制剂制备工艺筛选,短期内即拟定出较合理的工艺,经临床及14项生物学指标综合评定,该制剂疗效好,无明显的毒副作用。表明把一些快速、灵敏的医学检测技术引入药物制备工艺、质量标准及稳定性研究,可克服由于活性成分不清楚带来的一些困难,拓宽了研究途径,提高了研究水平。 相似文献
44.
T2毒素在灌流大鼠肠肝中的首过效应和代谢动力学 总被引:3,自引:0,他引:3
建立并用大鼠在体肠-肝灌流标本研究了T2毒素在大鼠肠肝中的首过效应和代谢转化动力学,T2毒素在大鼠肠肝中的主要代谢产物是HT2,3′-OHHT2和其葡萄糖醛酸结合物,T2毒素具有显著的肠肝首过效应,当毒素(42μg·ml~(-1))由上肠系膜动脉恒速单次灌流(8 ml·min~(-1))肠-肝标本时,穗态肝、肠抽提率分别为0.978和0.454,总有效清除率为7.91 ml·min~(-1),T2毒素在循环灌流大鼠肠-肝标本中的消除半衰期为6.5min,主要代谢产物HT2,3′-OHHT2的生成半衰期分别为8.5和38.5 min,结果表明,T2毒素经消化道中毒后,在肠和肝的首过代谢下能很快地转化为产物,因此,毒素在体内的毒效作用主要由其代谢产物表现出来。 相似文献
45.
目的观察碘伏用于超声根管预备对死髓牙根管治疗期间痛(endodontic interappointment pain EIP)发生率的影响及防治效果.方法对159例180颗慢性根尖周炎患者,随机分为3组(每组60颗患牙).第1组为传统手持器械对照组,第2组为超声生理盐水对照组,第3组为超声碘伏治疗组.采用临床观察分析法,观察治疗组与对照组临床反应的差异.结果超声治疗组Ⅱ~Ⅲ级EIP发生率为10%,对照组为36.67%(P<0.01),有显著差异性.结论碘伏应用于超声根管预备能预防和降低EIP的发生并减轻其疼痛程度. 相似文献
46.
The purpose of this study is to describe the characteristic computed tomographic (CT) signs of small bowel perforation after
blunt abdominal trauma and to evaluate their sensitivity. Nineteen preoperative CT scans were obtained from 16 patients with
surgically proven small bowel rupture secondary to blunt abdominal trauma. Only the CT findings described in the original
CT reports were used. Eleven of 19 CT scans (58 %) had findings that were unequivocal for bowel rupture (i.e., extraluminal
air and/or extravasation of oral contrast medium). Seven CT scans (37 %) had findings that were suggestive of severe small
bowel injury (i.e., focal small bowel wall thickening and/or free peritoneal fluid without other accompanying organ injuries).
In all, 95 % of cases of small bowel rupture had either pathognomonic or suggestive CT findings. One CT scan did not demonstrate
small bowel wall thickening, although a hemoperitoneum was present. CT is a sensitive method for suggesting severe small bowel
injury and rupture secondary to blunt abdominal trauma. 相似文献
47.
目的 在"创而床准备(WBP)"理论指导下,观察负压封闭吸引局部处理糖尿病溃疡的疗效.方法 收集2000年1月至2005年1月间收治的27例糖尿病溃疡患者作对照组,2005年1月至2007年6月的8例糖尿病溃疡患者为试验组.两组患者均经常规系统的治疗,试验组在创面的黑、黄期采用清创后负压吸引治疗.观察两组创而各分期间的演进情况.比较两组手术Ⅰ期修复率、入院首次及实施负压治疗后1、2、3周创面细菌学检查结果 .观察各期创面组织标本的HE染色和黄、红两期Ⅰ、Ⅲ型胶原纤维苦味酸-天狼猩红染色结果 及对其含量进行图像分析.结果 试验组患者创面各分期的演进速度、于术Ⅰ期修复率均优于以照组(100%比46%,P<0.05).治疗2周后试验组创面末检出致病菌,对照组检出率为66.7%(P<0.05).HE染色显示试验组各期间的演进类似于急性创面愈合过程,且试验组黄期Ⅰ、m型胶原总含量为12.28%,对照组为24.77%(P<0.01).结论 基于WBP方案的负压吸引治疗能促进糖尿病溃疡的创面愈合过程. 相似文献
48.
采用乳化聚合法制备阿糖胞苷纳米粒,研究其体内外释药特性。结果表明阿糖胞苷纳米粒体外释药规律符合双指数方程,有明显的缓释作用。在家兔体内的药物动力学过程符合二室模型,与阿糖胞苷注射剂相比,t1/2β和MRT延长,CL降低,表明阿糖胞苷纳米粒可显著延长阿糖胞苷在体内存留时间,具有明显的缓释特征。 相似文献
49.
This study is aimed at detecting gastrointestinal sounds (GIS) and correlating their characteristics with gastrointestinal
(GI) conditions. The central hypotheses are that GIS generation depends on the motility patterns and the mechanical properties
of the gut, and that changes in those result in measurable differences in GIS. An animal model which included both healthy
rats and those with small bowel obstruction (SBO) was developed. The acoustic bursts, of GIS were detected by amplitude thresholding
the signal envelope. Three methods of envelope estimation were proposed and evaluated. Envelope estimation using a Hilbert
transform was found to produce the best results in the current application. The duration and dominant frequency of each detected
GIS event was estimated and clear differences between healthy and diseased rats were discovered. In the control state, GIS
events were found to consistently be of relatively short duration (3–65ms). Although the majority of events in the SBO state
had similar short duration, infrequent longer events were also detected and appeared to be pathognomonic. Long duration events
(>100 ms) occurred in each of seven obstructed, but in none of 14 non-obstructed, cases (p<0.001). It is concluded that GIS
analysis may prove useful in the non-invasive, rapid, and accurate diagnosis of SBO. 相似文献
50.
P. Praamstra D. F. Stegeman M. W. I. M. Horstink C. H. M. Brunia A. R. Cools 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1995,103(3):429-439
In two experiments movement-related cortical potentials preceding voluntary movement were recorded. In experiment 1, subjects performed four motor tasks involving joystick movements. The four tasks differed in complexity (single vs sequential movements) and in the mode of movement selection, i.e., whether a movement or movement sequence was made in fixed or in self-determined directions. The choice of these tasks was based, firstly, on previous electrophysiological studies suggesting an effect of task-complexity on the amplitude of the readiness potential (RP) and, secondly, on previous positron emission tomography (PET) studies showing that activity of the supplementary motor area (SMA) is influenced by the mode of movement selection. The results show that, for single movements, RP amplitude is higher preceding freely selected movements than preceding movements in a fixed direction. In experiment 2 this effect was replicated using button presses instead of joystick movements. The results converge with PET evidence obtained in similar tasks and establish that the RP is modulated by the mode of movement selection. This modulation is probably related to differential involvement of the SMA. 相似文献