首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   24255篇
  免费   1959篇
  国内免费   1142篇
医药卫生   27356篇
  2024年   74篇
  2023年   252篇
  2022年   498篇
  2021年   763篇
  2020年   702篇
  2019年   587篇
  2018年   801篇
  2017年   879篇
  2016年   992篇
  2015年   894篇
  2014年   2041篇
  2013年   1887篇
  2012年   2120篇
  2011年   2202篇
  2010年   1658篇
  2009年   1365篇
  2008年   1252篇
  2007年   1315篇
  2006年   1175篇
  2005年   1021篇
  2004年   744篇
  2003年   661篇
  2002年   579篇
  2001年   476篇
  2000年   356篇
  1999年   307篇
  1998年   232篇
  1997年   198篇
  1996年   171篇
  1995年   149篇
  1994年   135篇
  1993年   96篇
  1992年   71篇
  1991年   98篇
  1990年   79篇
  1989年   53篇
  1988年   59篇
  1987年   43篇
  1986年   29篇
  1985年   59篇
  1984年   50篇
  1983年   36篇
  1982年   37篇
  1981年   32篇
  1980年   17篇
  1979年   27篇
  1978年   23篇
  1977年   17篇
  1976年   11篇
  1975年   13篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
目的 探讨视神经萎缩的有效治疗方法。方法 对324例526例眼视神经萎缩患,用胞二磷胆碱、肌苷做球后注射。结果 临床治愈88例,显效261例,进步106眼,有效率86.9%,收到了较满意的效果。结论 胞二磷胆碱、肌苷可通过卵磷脂的合成改善视神经周围的血液循环,刺激和促进视神经纤维的生物修补,从而导致视神经功能的改善和恢复。  相似文献   
82.
目的建立利巴韦林葡萄糖注射液中利巴韦林的快速测定方法.方法用紫外分光光度法直接测定利巴韦林葡萄糖注射液中利巴韦林的含量.结果在207 nm处,以水为溶媒,利巴韦林葡萄糖注射液中利巴韦林浓度在3~15μg/ml,与其相应的吸收度呈良好的线性关系(n=5;r=0.999 9),样品平均回收率为101.4%±0.53%.结论该法简便快速、准确可靠,适合药房快速分析.  相似文献   
83.
回顾性分析从 1 998年 1月至 2 0 0 0年 1 2月在我室接受单精子显微授精治疗的共 1 0 2个周期。以 2 0 0 0年2月为界 ,随着显微操作技术 ,的改进和操作环境的改善 ,后阶段单精子显微注射的存活率 (90 6 % )、受精率 (73 3 % )、胚胎发育率 (97 3 % )较前阶段 (分别为 68 8% ,39 0 % ,78 7% )有显著提高。两阶段临床妊娠率分别为 41 3 %和2 1 4% ,目前本室建立的单精子胞质内注射技术能有效地治疗临床严重男性不育和受精障碍  相似文献   
84.
BackgroundDiagnostic injections are commonly utilized in the workup of painful total knee arthroplasties (TKA), particularly when the diagnosis remains unclear. However, current literature provides limited evidence regarding the utility and prognostic capability of anesthetic injections in this scenario. This study sought to establish the role of diagnostic injections in predicting successful revision TKA.MethodsA retrospective review was conducted on 144 consecutive aseptic revision TKAs receiving diagnostic anesthetic injections. Instability (57.6%) and aseptic loosening (33.3%) comprised most revision etiologies. Patient-reported percentage pain relief after the injection was statistically correlated with KOOS JR, Knee Society Score, UCLA Activity Level, and satisfaction scores.ResultsAbout 74.3% (107/144) of revision TKAs reported >50% pain relief after injection. There were no differences in pain relief based on revision indication (P = .841). Improvement from preoperative activity level was greater in the >50% pain relief group (P = .024). Four-month patient satisfaction did not differ between patients who reported >50% and ≤50% pain relief (67% vs. 66%, P = .130). About 64% of patients who reported >50% pain relief were satisfied at minimum 1-year follow-up, compared with only 47% of those who reported ≤50% pain relief after diagnostic injection (P < .001).ConclusionStudy results show that patients reporting >50% pain relief after diagnostic injection have improvements in activity level and maintain greater satisfaction at minimum 1-year than those reporting ≤50% pain relief. Expectations for improvement after revision TKA should be tempered if diagnostic anesthetic injection yields minimal subjective pain relief.  相似文献   
85.
86.
DNA vaccine evaluation in small animals is hampered by low immunogenicity when the vaccines are delivered using a needle and syringe. To overcome this technical hurdle we tested the possibility that a device developed for human intradermal medicine delivery might be adapted to successfully deliver a DNA vaccine to small animals. Disposable syringe jet injection (DSJI) does not currently exist for small animals. However, a commercialized, human intradermal device used to to administer medicines to the human dermis in a 0.1 mL volume was evaluated in Syrian hamsters. Here, we found that hantavirus DNA vaccines administered to hamsters using DSJI were substantially more immunogenic than the same vaccines delivered by needle/syringe or particle mediated epidermal delivery (gene gun) vaccination. By adjusting how the device was used we could deliver vaccine to either subcutaneous tissues, or through the skin into the muscle. RNA and/or antigen expression was detected in epidermal, subepidermal and fibroblast cells. We directly compared six optimized and non-optimized hantavirus DNA vaccines in hamsters. Optimization, including codon-usage and mRNA stability, did not necessarily result in increased immunogenicity for all vaccines tested; however, optimization of the Andes virus (ANDV) DNA vaccine protected vaccinated hamsters from lethal disease. This is the first time active vaccination with an ANDV DNA vaccine has shown protective efficacy in the hamster model. The adaptation of a human intradermal jet injection device for use as a method of subcutaneous and intramuscular jet injection of DNA vaccines will advance the development of nucleic acid based medical countermeasures for diseases modeled in hamsters.  相似文献   
87.
The parabiliary venous system   总被引:6,自引:0,他引:6  
Summary The parabiliary venous system originates from the pancreatico-duodenal and pyloro-duodenal veins, runs along the common bile-duct and the hepatic artery, and divides in the liver hilum into a venous network within the hilar plate. Embryologically, this system, apparently independent of the portal vein, develops together with the bile-ducts and the hepatic artery: these three structures are within the substance of the vasculo-biliary sheaths, and the whole complex invades the liver well after the distribution of the portal vein has been established. It should be pointed out that segments I and IV also appear rather late. Seventy-four specemins with injection of the system have been studied. The hilar plexus sends branches to the veins of the segments adjacent to the hilum. Some vessels directly supply the inferior surface of the quadrate lobe or the caudate lobe, or the left lobe. In 46.50% of specemins, part of the cystic veins are anastomosed with the Parabiliary system.
Le système veineux parabiliaire
Résumé Le système veineux parabiliaire prend origine dans les veines pancréatico-duodénales et pyloro-duodénales, monte le long de la voie biliaire et l'artère hépatique, et se termine dans le hile dans un lascis veineux situé dans la plaque hilaire. Embryologiquement il semble étranger à la formation de la veine porte, se constitue en même temps que les canaux biliaires et les artères intra-hépatiques: ces trois éléments sont situés dans la texture même des enveloppes vasculo-biliaires, et le tout envahit le foie bien après la pénétration de la veine porte. L'étude porte sur 74 foies dans lesquels le système s'est trouvé injecté. Le plexus hilaire envoie des collatérales qui se jettent dans les veines des segments adjacents au hile. Mais certaines branches irriguent directement la face inférieure du lobe carré, ou le lobe gauche. Dans 46,50% des cas, une partie des veines cystiques se jettent dans ce système.
  相似文献   
88.
雄性SD大鼠54只,体重250~300g,用细胞内记录和细胞内注射的方法,将灌注的(2%NB溶于0.1mol/LKCl,pH7.4)记录电极(尖端直径80~100nm,电阻60~100MΩ)置于孤束核吻侧部,同时用味素(盐,酸,糖,苦)灌洗舌。在完成生理学记录、确认其至少对一种味素起反应后,进行细胞内注射.成色反应证明71个吻例孤束核味觉神经元被标记.标记神经元经三维重组系统重组后,依据细胞体积、胞体面积、树突节段平均长度、膨体密度、树突棘密度和初级树突数量等六个形态学特征,进行统计学(ANOVA)定量分析,将标记细胞分为A,B,C,D,E,F六类.每类细胞至少有一个形态学特征与其它五类有显著的不同.本研究还发现味谱值与标记细胞的大小及树突分校点的数量呈正相关而与树突棘密度呈负相关;对四种基本味素反应的标记细胞数量依次为盐>酸>甜>苦;C类神经元的味谱值较小;单纯对苦(Quinine)反应的神经元与单纯对其它三种味素反应的神经元相比,具有胞体小、树突在冠状和矢状切面上的扩展范围小、树突整体接受面积也小的特征;在对盐类反应的神经元中,单纯氯化钠反应神经元与对所有盐类都反应的神经元相比,具有胞体表面积大、树突接受区域大、树突总长度长及在水平切面上吻尾扩展长的特点。此结果为?  相似文献   
89.
Intracytoplasmic sperm injection in the mouse   总被引:9,自引:0,他引:9  
Intracytoplasmic sperm injection (ICSI) into mouse oocytes involvesa very low survival rate. This study was designed to determinewhy ICSI frequently fails in mice. Metaphase II oocytes wereobtained from superovulated 4–6 week old F1 hybrid mice.Spermatozoa were retrieved from the epididymis of 12–14week old F1 hybrid mice. The spiked microinjection pipette usedto inject a spermatozoon into the ooplasm had outer and innerdiameters of 10 and 8 µm respectively. The oocytes usedin the first part of the study were not activated (group 1).Some oocytes were incubated with calcium ionophore for 5 min(group 2). The injected oocytes were evaluated 6, 20, 48 and72 h after injection. A total of 143 eggs in each group underwentICSI. In group 1, sperm heads escaped into the perivitellinespace. In all, 63 (47%) of the remaining oocytes were damagedduring the injection or had degenerated by the first evaluation.The survival rate was 53%, but fertilization did not occur.In group 2, 31 oocytes (22%) were damaged during microinjectionor soon degenerated. Two oocytes underwent accidental subzonalinsemination. Six oocytes were fertilized (4.2%) among the 78%of survivors. After injection, the sperm tail was found in thecytoplasm (27 and 31% in groups 1 and 2 respectively), the perivitellinespace (45% in both groups) or protruding through the zona pellucida(28 and 23% respectively). More oocytes degenerated when thetail remained in the cytoplasm, i.e. 78% in group 1 and 36%in group 2.  相似文献   
90.
黄芪射液目前被临床广泛用于抗病毒,调节免疫治疗。近年来报道的黄芪注射液不良反应有迟发性严重静脉炎、过敏性休克、少尿、药物热、溶血性贫血、喉头水肿、急性荨麻疹、剧烈头痛等。提示临床应用中应当予以重视。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号