首页 | 本学科首页   官方微博 | 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   100篇
  免费   13篇
  国内免费   2篇
妇产科学   1篇
基础医学   30篇
口腔科学   7篇
临床医学   4篇
内科学   23篇
神经病学   4篇
特种医学   1篇
外科学   7篇
综合类   19篇
药学   15篇
中国医学   4篇
  2022年   6篇
  2021年   12篇
  2020年   4篇
  2019年   1篇
  2018年   6篇
  2017年   5篇
  2016年   5篇
  2015年   10篇
  2014年   3篇
  2013年   11篇
  2012年   6篇
  2011年   3篇
  2010年   3篇
  2009年   6篇
  2008年   3篇
  2007年   4篇
  2006年   3篇
  2005年   4篇
  2004年   7篇
  2003年   1篇
  2002年   1篇
  2001年   2篇
  2000年   4篇
  1999年   1篇
  1998年   1篇
  1996年   1篇
  1994年   1篇
  1989年   1篇
排序方式: 共有115条查询结果,搜索用时 15 毫秒
101.
目的以A型肉毒类毒素为模型药,探讨聚乳酸用于包裹生物大分子的可能性。方法采用水-油-水复乳溶剂挥发法制备微球,并测定粒径和包封率,用间接酶联免疫吸附测定法检测免疫鼠血清中的抗体水平。结果获得了60%以上的包封率,微球粒径可控制在30~200μm,微球在体内缓慢释放诱导抗体产生。结论采用水-油-水复乳溶剂挥发法制备微球,成功地制备了A型肉毒类毒素免疫微球,可用于运载生物大分子。  相似文献   
102.
用流延法制备壳聚糖与聚乳酸或聚(R)-3-羟基丁酸甲酯共混膜。壳聚糖-聚乳酸(1∶1,w/w)和壳聚糖-聚(R)-3-羟基丁酸甲酯(1∶1,w/w)共混膜的抗拉强度为(25.39±1.63)和(23.49±0.43)MPa,吸水率为(32.65±2.41)%和(33.72±3.11)%。该壳聚糖-聚乳酸膜在人工组织液中浸泡45 d后,降解率为(32.26±0.56)%,提示其可诱导新组织再生。  相似文献   
103.
目的将丝裂霉素C(MMC)与聚乳酸(PLA)制成凝胶制剂固定在兔气管外壁给药,并建立超高效液相色谱-串联质谱法(UHPLC-MS/MS)测定兔体内释放丝裂霉素C的含量。方法新西兰大白兔30只,气管处外科手术形成瘢痕组织,将0.2 ml载有不同剂量(0.05、0.1、0.2、0.4和0.6mg)的聚乳酸凝胶与明胶海绵的混匀后置于损伤后的气管外壁,固定后缝合手术切口。兔血浆经乙酸乙酯提取后,采用UHPLC-MS/MS法测定MMC血浆药物浓度。结果兔血浆中丝裂霉素C的质量浓度在1~1 000μg·L-1范围内线性良好(r=0.9977,权重W:1/x2);血浆中丝裂霉素C的检出限(信噪比为3)为0.2μg·L-1;其平均回收率在85%~115%之间;日内及日间的相对标准偏差(RSDs)均小于15%,满足生物样品分析要求。兔气管外壁给药后,血浆中MMC释放量少,血药浓度极低,此为选择UHPLC-MS/MS的主要依据。结论该方法简便快捷、灵敏度高、重现性好,适用于丝裂霉素C的体内大批量样品定量分析及药代动力学等方面的研究。MMC-PLA凝胶局部用药后吸收量极少,说明此凝胶剂对全身影响不大。  相似文献   
104.
目的:探讨聚乳酸基形状记忆输卵管避孕材料的安全性。方法:雌性大白兔15只随机分为实验组、自身对照组及空白组,分别于术后1、4、8周,取输卵管制作标本,以光镜及透射电镜观察黏膜变化。结果:实验组及自身对照组手术侧,肉眼可见材料植入体内后变短粗,后期逐渐变细小,光镜下初期可见输卵管皱襞被压缩,后皱襞内逐渐有纤维增生。电镜下上皮细胞内有异物颗粒,后期肌细胞间可见大量胶原。结论:聚乳酸基形状记忆材料植入兔输卵管后能刺激输卵管纤维组织增生,材料可降解,对机体无危害。  相似文献   
105.
Large bony defects often show a delayed healing and have an increasing risk of infection. Several materials are used for the coverage of large defects. These materials must be biocompatible, easy to use, and must have an appropriate stability to present a mechanical hindrance. Aim of this study was to investigate two different biodegradable membranes for defect coverage in a sheep model. Round cranial defects (1.5 cm diameter) were created in sheep. Six different treatments were investigated: defects without membrane, defects covered with a poly(D,L-lactide) or with a 70/30 poly(L/D,L-lactide) membrane and all defects with or without spongiosa filling. The sheep were sacrificed 12 or 24 weeks postoperatively. Bone formation in the defects was quantified by computer-assisted measurements of the area of the residual defect on CT radiographs. Histomorphometry and host-tissue response were evaluated by light microscopy. The biocompatibility was investigated by analyzing the amount of osteoclasts and foreign body cells. Both membranes served as a mechanical hindrance to prevent the prolapse of soft tissue into the defect. The biocompatibility test revealed no differences in the amount and distribution of osteoclasts at the two investigated time points and between the investigated groups. No negative effect on the tissue regeneration was detectable between the investigated groups related to the type of membrane, but a foreign body reaction around the two membrane types was observed. In the membrane-covered defects, the spongiosa showed a progressing remodeling to the native bony structure of the cranium. The groups without spongiosa partly revealed new bone formation, without complete bridging in any group or at any time point. Comparing the 12 and 24 weeks groups, an increased bone formation was detectable at the later time point. In conclusion, the results of the present in vivo study reveal a good biocompatibility and prevention of soft tissue prolapse of the two used membranes without differences between the membranes. An enhanced remodeling of the spongiosa into native bony structures under the membranes was detectable, but no osteopromoting effect was observed due to the membranes.  相似文献   
106.
Functional recovery after large excision of dorsal roots is absent because of both the limited regeneration capacity of the transected root, and the inability of regenerating sensory fibers to traverse the dorsal root entry zone. In this study, bioresorbable guidance conduits were used to repair 6-mm dorsal root lesion gaps in rats, while neurotrophin-encoding adenoviruses were used to elicit regeneration into the spinal cord. Polyester conduits with or without microfilament bundles were implanted between the transected ends of lumbar dorsal roots. Four weeks later, adenoviruses encoding NGF or GFP were injected into the spinal cord along the entry zone of the damaged dorsal roots. Eight weeks after injury, nerve regeneration was observed through both types of implants, but those containing microfilaments supported more robust regeneration of calcitonin gene-related peptide (CGRP)-positive nociceptive axons. NGF overexpression induced extensive regeneration of CGRP(+) fibers into the spinal cord from implants showing nerve repair. Animals that received conduits containing microfilaments combined with spinal NGF virus injections showed the greatest recovery in nociceptive function, approaching a normal level by 7-8 weeks. This recovery was reversed by recutting the dorsal root through the centre of the conduit, demonstrating that regeneration through the implant, and not sprouting of intact spinal fibers, restored sensory function. This study demonstrates that a combination of PNS guidance conduits and CNS neurotrophin therapy can promote regeneration and restoration of sensory function after severe dorsal root injury.  相似文献   
107.

Objectives

An adult pig model of retrosternal adhesion formation via an inferior hemisternotomy was used to evaluate the formation and development of pericardial and retrosternal adhesions, as well as adhesion reduction using two thicknesses of a bioabsorbable polylactide film.

Materials and methods

Twenty-five adult female pigs (70 kg) were allocated to either a control group or four different treatments using two thicknesses (0.02 or 0.05 mm) of a polylactide film. In each animal, the film was placed either inside the pericardium or inside and outside the pericardium.

Results

All animals demonstrated adhesions between the posterior and lateral surfaces of the heart and pericardium. Thick fibrous retrosternal adhesions and pericardial adhesions were noted in the control animals with complete obliteration of the anatomical plane. The polylactide films preserved the anatomical planes and reduced the adhesion response.

Conclusions

A reproducible animal model was used to examine the formation and reduction of retrosternal and pericardial adhesions. A polylactide film placed inside the pericardium or between the heart and sternum was able to limit adhesion formation and maintain the anatomical planes, which would facilitate reentry.  相似文献   
108.
Manipulation of cellular processes in vivo by the delivery of drugs, proteins or DNA is of paramount importance to neuroscience research. Methods for the presentation of these molecules vary widely, including direct injection (either systemic or stereotactic), osmotic pump-mediated chronic delivery, or even implantation of cells engineered to indefinitely secrete a factor of interest. Biomaterial-based delivery systems represent an alternative to more traditional approaches, with the possibility of increased efficacy. Drug-releasing biomaterials, either as injectable microspheres or as three-dimensional implants, can deliver a molecule of interest (including small molecule drugs, biologically active proteins, or DNA) over a more prolonged period of time than by standard bolus injection, avoiding the need for repeated administration. Furthermore, sustained-release systems can maintain therapeutic concentrations at a target site, thus reducing the chance for toxicity. This review summarizes applications of polymer-based delivery of small molecule drugs, proteins, and DNA specifically relevant to neuroscience research. We detail the fabrication procedures for the polymeric systems and their utility in various experimental models. The biomaterial field offers unique experimental tools with downstream clinical application for the study and treatment of neurologic disease.  相似文献   
109.
110.
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