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   941篇
  免费   78篇
  国内免费   67篇
耳鼻咽喉   5篇
儿科学   2篇
妇产科学   3篇
基础医学   138篇
口腔科学   53篇
临床医学   123篇
内科学   56篇
皮肤病学   5篇
神经病学   18篇
特种医学   39篇
外科学   122篇
综合类   180篇
预防医学   31篇
眼科学   8篇
药学   233篇
中国医学   55篇
肿瘤学   15篇
  2023年   6篇
  2022年   18篇
  2021年   41篇
  2020年   21篇
  2019年   34篇
  2018年   33篇
  2017年   31篇
  2016年   33篇
  2015年   21篇
  2014年   54篇
  2013年   108篇
  2012年   61篇
  2011年   54篇
  2010年   35篇
  2009年   42篇
  2008年   37篇
  2007年   34篇
  2006年   56篇
  2005年   39篇
  2004年   32篇
  2003年   36篇
  2002年   41篇
  2001年   33篇
  2000年   26篇
  1999年   23篇
  1998年   10篇
  1997年   16篇
  1996年   10篇
  1995年   9篇
  1994年   10篇
  1993年   9篇
  1992年   11篇
  1991年   9篇
  1990年   6篇
  1989年   7篇
  1988年   3篇
  1987年   6篇
  1986年   5篇
  1985年   10篇
  1984年   3篇
  1983年   4篇
  1982年   3篇
  1981年   1篇
  1980年   1篇
  1979年   2篇
  1976年   1篇
  1973年   1篇
排序方式: 共有1086条查询结果,搜索用时 468 毫秒
41.
IntroductionPostoperative dysphonia is mostly caused by vocal fold scarring, and careful management of vocal fold surgery has been reported to reduce the risk of scar formation. However, depending on the vocal fold injury, treatment of postoperative dysphonia can be challenging.ObjectiveThe goal of the current study was to develop a novel prophylactic regenerative approach for the treatment of injured vocal folds after surgery, using biodegradable gelatin hydrogel microspheres as a drug delivery system for basic fibroblast growth factor.MethodsVideoendoscopic laryngeal surgery was performed to create vocal fold injury in 14 rabbits. Immediately following this procedure, biodegradable gelatin hydrogel microspheres with basic fibroblast growth factor were injected in the vocal fold. Two weeks after injection, larynges were excised for evaluation of vocal fold histology and mucosal movement.ResultsThe presence of poor vibratory function was confirmed in the injured vocal folds. Histology and digital image analysis demonstrated that the injured vocal folds injected with gelatin hydrogel microspheres with basic fibroblast growth factor showed less scar formation, compared to the injured vocal folds injected with gelatin hydrogel microspheres only, or those without any injection.ConclusionA prophylactic injection of basic fibroblast growth factor -containing biodegradable gelatin hydrogel microspheres demonstrates a regenerative potential for injured vocal folds in a rabbit model.  相似文献   
42.
《Journal of endodontics》2019,45(6):706-715
IntroductionAlginate/gelatin hydrogel (Alg-Gel) scaffold has been applied in tissue engineering, but the research on its application in dental tissues regeneration is still lacking. We investigated the effect of this scaffold on human dental pulp stem cells (hDPSCs).MethodshDPSCs were cultured in both Alg-Gel and 3D-printed Alg-Gel scaffolds. Cell growth and adhesion were compared using fluorescein isothiocyanate–phalloidin staining and scanning electron microscopic micrographs. Changes in the proliferation in hDPSCs cultured in the complete culture medium containing aqueous extracts of the Alg-Gel or 3D-printed Alg-Gel scaffolds were examined using Cell Counting Kit-8 assay and flow cytometry analysis. Cells were cultured in the mineralization medium containing aqueous extracts of the Alg-Gel or 3D-printed Alg-Gel scaffolds for 7 or 14 days, and the differentiation of cells was shown by alizarin red S staining and alkaline phosphatase staining. The messenger RNA and protein expression of mineralization-related genes were detected with real-time polymerase chain reaction and Western blotting. Elemental analysis was used to test the material extract composition.ResultsMore cells were grown and adhered to the 3D-printed Alg-Gel scaffolds than the Alg-Gel scaffolds. The aqueous extracts of 3D-printed scaffolds can promote cell proliferation, and compared with Alg-Gel scaffolds, the extracts of 3D-printed scaffolds were more effective. Compared with the negative control group, 3D-printed Alg-Gel scaffold and Alg-Gel scaffold aqueous extracts promoted osteogenic/odontoblastic differentiation of hDPSCs with the enhanced formation of bone-like nodules and the alkaline phosphatase staining. The expression of mineralization-related genes was also up-regulated. 3D-printed scaffold aqueous extract contained more calcium and phosphorus ions than the Alg-Gel scaffold.ConclusionsThese findings suggest that compared with the Alg-Gel scaffold, 3D-printed Alg-Gel is more suitable for the growth of hDPSCs, and the scaffold extracts can better promote cell proliferation and differentiation.  相似文献   
43.
目的:观察巨块型肝癌破裂出血患者行血管介入栓塞和栓塞加化疗药物灌注治疗的疗效。方法:选取2006年12月-2014年2月在我院住院的30例巨块型肝癌破裂出血行急诊介入栓塞的患者,按栓塞方法不同分为单纯明胶海绵栓塞组(简称单纯组)15例,栓塞时加化疗药物灌注组(简称联合组)15例。观察两组患者术后不良反应及并发症。结果:两组患者均1次栓塞止血成功,住院期间无复发破裂出血;两组患者术后恶心、呕吐、腹痛、食欲不振等症状发生率比较,差异有统计学意义(P〈0.05);联合组患者术后ALT、GGT、TBil等检测结果均高于单纯组,差异有统计学意义(P〈0.05);联合组有1例死亡。结论:巨块型肝癌破裂出血急诊介入栓塞治疗时宜选择单纯用明胶海绵栓塞,其安全有效,不良反应少。  相似文献   
44.
Background: Since the urea breath test (UBT) indirectly detects gastric Helicobacter pylori infection by measuring urease activity, the possibility of false-positive results due to other urease-producing bacteria cannot be excluded. Previous studies have shown that increased 14CO2 activity in early breath samples could be attributed to urea hydrolysis in the oropharynx. For that reason, reliable assessment of H. pylori status is hampered for at least 20 min after administration of a 14C-urea drink. Methods: To overcome this problem, we have developed a modified breath test in which 111kBq 14C-urea is supplied in a gelatin capsule, which prevents release of 14C before reaching the stomach. Our modified 14C UBT was evaluated in 100 healthy volunteers, and results were compared with those from enzyme-linked immunosorbent assay serology. Results: The study showed a 99% concordance between the two non-invasive tests. When a biometric method for determination of cut-off values between positive and negative UBT results with the smallest possible arbitrariness was used, the calculated statistical probability of a false diagnosis was lowest in the 10-min breath sample (0.20%), and 100% sensitivity and specificity was achieved. Our capsule method was also compared with the urea drink method and was found more reliable because no overlapping in 14CO2 activity occurred between H. pylori-positive and -negative subjects, whereas conventional breath testing showed overlapping during the whole 30-min test period. Our study also showed that a fatty test meal lowers the 14CO2 excretion the first 20 min and may adversely affect the accuracy of a rapid UBT. Conclusions: Supplying the 14C-urea in a capsule obviates the problem of false-positive results in early breath samples and makes it possible to diagnose H. pylori infection with 99.8% reliability from a single 10-min breath sample, without the use of a test meal or adjustments for assumed individual CO2 production.  相似文献   
45.
邵凤  李桂龙  王春龙  元英进 《中草药》2007,38(3):383-385
目的筛选银杏叶液体硬胶囊的最佳处方。方法建立沉降体积比的测定方法。采用正交试验设计优选处方。结果优选处方以茶油为分散介质,含4%氢化蓖麻油和1%二氧化硅制备的液体硬胶囊内容物混悬性好。结论该处方设计合理,制备工艺简单,制剂稳定。  相似文献   
46.
目的评价肠溶性瑞巴派特壳聚糖胶囊的释药作用,考察其结肠定位效果。方法将瑞巴派特1 mg装入壳聚糖胶囊中,并用羟丙基甲基纤维素邻苯二甲酸酯(HPMCP)包裹胶囊,观察胶囊的体外释药性能。在乙醚麻醉下通过聚乙烯管大鼠口服给予瑞巴派特壳聚糖胶囊4 mg,对照组口服同剂量的明胶胶囊和羧甲基纤维素溶液。于给定的时间间隔取血,取出结肠组织,分离提取药物,用HPLC法测定大鼠血液及结肠中药物浓度。结果在6 h体外溶出试验中,即人工胃液2 h和人工肠液4 h中,瑞巴派特从壳聚糖胶囊中的释药量的质量分数小于10%。大鼠口服瑞巴派特壳聚糖胶囊时,在结肠黏膜中的药物含量-时间曲线下面积(AUCLI0-9,16.01 mg.h.L-1)分别是明胶胶囊和羧甲基纤维素溶液的2.5倍和4.4倍。口服瑞巴派特壳聚糖胶囊,大鼠血浆药物含量-时间曲线下面积(AUCPL0-9)为1.02 mg.h.L-1,同剂量的明胶胶囊和羧甲基纤维素溶液分别是2.16 mg.h.L-1和1.89 mg.h.L-1,表明在壳聚糖的作用下,与明胶胶囊或羧甲基纤维素溶液比较,瑞巴派特从胃肠道吸收进入血液循环的量较少。结论在HPMCP的保护下,壳聚糖是瑞巴派特在结肠释药的一种有效的载体。  相似文献   
47.
Background: When investigating the degree of formation of intimal hyperplasia (IH) quantification of the extent of the lesion is crucial to its assessment and analysis. The aim of the present study was to establish a new methodology (IH index) for estimating the degree of IH associated with vascular prosthesis implantation. Methods: Ten female Merino sheep underwent a standard gelatin sealed Dacron (GSD) patch grafting procedure in the left common carotid artery. The grafts were harvested 4 weeks following implantation and processed for assessment of IH by two methodologies ? mean intimal thickness (MIT) and IH index. The advantages and disadvantages of the two methods for expressing the degree of IH were compared. Results: The IH index is less labour intensive but is as accurate as the MIT method in quantifying the IH lesion, statistical analysis showing high correlation and measurement agreement between the two methods. Conclusion: The IH index is a labour saving standardized methodology for quantification of IH in the current animal model.  相似文献   
48.
阿霉素明胶微球的制备及体外释药特性   总被引:6,自引:0,他引:6  
目的对阿霉素明胶微球(ADM-GMS)的制备工艺及体外释药特性进行研究.方法用乳化交联法制备阿霉素明胶微球,采用正交试验设计法考察影响制备工艺的各因素.用扫描电镜观察微球表面形态.并对阿霉素明胶微球的粒径大小及其分布、载药量、包封率、体外释药、稳定性等进行了测定.结果微球形态圆整,大小均匀、表面光滑,平均粒径为69.154μm,87.32%的微球粒径分布在50~120μm.微球平均载药量为2.13%,包封率为42.62%.微球体外降解和释药特性满足要求,且37℃下性质稳定.结论该制备工艺稳定,制得的阿霉素明胶微球有望成为临床用动脉栓塞术治疗癌症的新制剂.  相似文献   
49.
肺靶向炎琥宁明胶微球的制备   总被引:5,自引:0,他引:5       下载免费PDF全文
 目的对炎琥宁肺靶向明胶微球的处方、工艺、释药特性及其体内靶向性进行研究。方法以生物降解材料明胶为载体,采用乳化交联法制备炎琥宁明胶微球;单因素考察的基础上,利用正交实验设计筛选最佳处方和工艺;考察其体外释药特性;兔耳缘静脉注射微球后,取肺组织切片,体内试验结果初步考察其肺靶向性。结果所制备的炎琥宁明胶微球外形圆整,大小均匀,平均粒径为17.14μm,载药量为2.08%,包封率为70.94%;1.5 h体外释放50%左右,12 h可达90%以上。体内试验结果初步验证其具有一定肺靶向性。结论筛选的最佳处方工艺可制备性质优良的炎琥宁肺靶向明胶微球。  相似文献   
50.
鱿鱼皮胶原蛋白水解肽抗氧化活性研究   总被引:21,自引:1,他引:21  
目的探讨秘鲁鱿鱼(Dosidicus eschrichitiiSteenstrup)皮胶原蛋白多肽组分对自由基的清除作用以及水解产物的体内抗氧化作用,为鱿鱼加工废弃物的高值化利用探索一条新途径。方法采用化学发光法研究胶原蛋白活性多肽体外对超氧阴离子自由基(O2.-)和羟自由基(.OH)的清除作用,并筛选出体外清除自由基活性最好的组分;灌胃于D-半乳糖致衰老的模型小鼠,测定小鼠血液及皮肤中的超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活力和丙二醛(MDA)及羟脯氨酸(Hyp)含量。结果与结论鱿鱼皮胶原蛋白多肽分子量小于2000D组分对O2.-和.OH具有较好的清除效果,该活性多肽组分可以提高小鼠血液及皮肤中SOD和GSH-Px的活力,降低MDA含量,并能提高小鼠皮肤组织中Hyp的含量。  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