共查询到19条相似文献,搜索用时 78 毫秒
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目的:初步评价一种新型瓷嵌体修复用树脂粘接材料的生物安全性。方法:按照国标GB16886.5-1997,医药行业标准YY/T0268-2001、YY/T0279-1995、以及YY/T 0244-1996所规定的方法对本院材料科新研制的复合树脂粘接材料的生物安全性进行评价,内容包括短期急性全身毒性试验,粘膜刺激实验,细胞毒性试验。结果:此种新型瓷嵌体修复用树脂粘接材料无细胞毒性,无短期全身毒性,对口腔黏膜无刺激。结论:此种新型瓷嵌体修复用树脂粘接材料具有良好的生物安全性,可以进行进一步安全性检测。 相似文献
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近年来,胶原基创面修复类医疗器械产品的咨询和申报数量明显上升。本文对胶原基创面修复材料现状进行了介绍,并结合技术审评的情况,对其安全性的评价进行思考,以期对该类产品的申报注册有所帮助。 相似文献
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目的:研究聚合瓷嵌体修复活髓后牙大面积牙体缺损(Big dentin defect,BDD)中的临床疗效。方法:从2009年6月到2011年6月,于我院牙科就诊病患中,后牙的牙体缺损大于1个牙尖者有80例,共87颗牙齿。以数字法随机分成治疗组(41例,46颗)及对照组(39例,43颗)。对照组以高嵌体方案治疗,治疗组以聚合瓷嵌体方案治疗。对比两组一周以及一年后修复体评价情况。结果:治疗一周后,治疗组在美观方面显著优于对照组,差异有统计学意义(u=2.038,P0.05)。而两组对比术后敏感以及牙周状况等数据,差异均无统计学意义(u=1.132,1.389,均P0.05)。治疗一年后,治疗组在修复体折裂以及美观等方面显著优于对照组。差异有统计学意义(u=3.138,2.874,均P0.05)。两组在继发龋和边缘着色,邻接以及肩台适合和牙周状况等方面对比,差异均无统计学意义(u=1.132,1.374,1.454,1.268,1.366,均P0.05)。结论:聚合瓷嵌体对于活髓后牙BDD的修复效果较为显著,可较大程度恢复病患牙体功能,减少继发龋的发生率。不易折裂又更加美观,值得临床推荐。 相似文献
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目的通过用流式细胞术(FCM)观察丙稀酰胺接枝改性聚丙烯膜 (PP-g-AAm)的生物相容性,来评价FCM在检测医用生物材料的生物相容性中的作用.方法:用材料浸提液培养L929细胞24 h后用FCM检测细胞增殖周期; 用改性前、后的膜材料分别与新提取的PRP(富含血小板血浆)和PBMC(末梢血单个核细胞)孵育培养后,用FCM分别检测血小板和PBMC的激活标志物CD62P、CD63和CD69.结果:PP-g-AAm 组的PI与阴性组及空白对照组比较差异无统计学意义(P=0.063,P=0.053),而与阳性对照组比较差异有统计学意义(P=0.002).PP-g-AAm膜组CD62P、CD63及CD69的表达率明显少于对照组(P=0.042, P=0.004,P=0.013).结论:PP-g-AAm无细胞毒性并具有良好的生物相容性,FCM在生物材料的生物相容性评价中有着广泛的应用价值. 相似文献
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目的:探讨不同修复方式对儿童乳牙牙体缺损修复的治疗效果和安全性。方法:选择2011年1月至2015年1月在我院因牙体缺损严重无法填充修复的乳牙牙体缺损患儿67例。将所有患者随机分为三组,记为A组(22例)、B组(22例)和C组(23例)。A组患儿进行金属预成冠修复,B组患儿进行铸瓷嵌体修复,C组患儿进行银汞合金充填修复。随访18个月,比较3组患儿的治疗效果和不良反应的发生情况。结果:C组患儿随访期间发生牙痛6例,食物嵌塞、修复体和牙体之间出现裂缝的患儿各5例,牙龈充血3例,继发龋2例;B组患儿发生牙痛3例,食物嵌塞、牙龈充血、修复体和牙体之间出现裂缝以及继发龋等各1例;A组患儿发生疼痛和食物嵌塞各2例,牙龈充血1例。A组和B组患儿以上不良事件的发生率明显低于C组(P0.05),A组发生不良事件的发生率低于B组,但是差异无统计学意义(P0.05)。结论:应用金属预成冠修复和铸瓷嵌体修复儿童乳牙牙体缺损较银汞合金充填修复具有更好的临床效果,且安全性更高。 相似文献
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5种生物杀虫剂对4种天敌昆虫的安全性评价 总被引:1,自引:0,他引:1
【目的】生物杀虫剂及天敌昆虫的应用是绿色防控的发展方向,但有关生物杀虫剂对天敌昆虫的安全性尚不明确。研究生物杀虫剂对天敌昆虫的影响可以为更好地协调使用生物杀虫剂和天敌昆虫提供理论依据。【方法】在实验室条件下采用药膜法和滤纸膜片法测定了5种生物杀虫剂(苦参碱、桉油精、鱼藤酮、除虫菊素、橄榄鲨)在田间推荐使用浓度下,对4种天敌昆虫(丽蚜小蜂、东亚小花蝽、食蚜瘿蚊、巴氏新小绥螨)的致死率。【结果】除虫菊素对丽蚜小蜂、东亚小花蝽、巴氏新小绥螨的影响较大,致死率均达到100%;鱼藤酮对丽蚜小蜂、食蚜瘿蚊、巴氏新小绥螨的影响均较大,致死率在98.65%以上;橄榄鲨对丽蚜小蜂、东亚小花蝽、食蚜瘿蚊的影响较小,致死率均小于30%;苦参碱对丽蚜小蜂的影响最大,致死率达100%,对食蚜瘿蚊和巴氏新小绥螨的影响较小,致死率分别为15.56%和15.91%;桉油精对巴氏新小绥螨的影响最大,致死率达100%,对东亚小花蝽和食蚜瘿蚊的影响较小,致死率分别为15.91%和6.67%。【结论】这5种生物杀虫剂中,橄榄鲨对丽蚜小蜂、东亚小花蝽、食蚜瘿蚊安全,桉油精对东亚小花蝽、食蚜瘿蚊安全,苦参碱对食蚜瘿蚊、巴氏新小绥螨安全,鱼藤酮对东亚小花蝽安全,除虫菊素对食蚜瘿蚊安全。 相似文献
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目的:在动物体内进行新型钛材料的生物安全性研究。方法:采用TAI纯钛板材(Ti≥99.9%,宝鸡英耐特有色金属有限公司),通过对钛材料的喷砂、酸蚀、碱热等处理后,构建微纳双级骨仿生结构。对处理材料进行扫描电镜观察后,再经过兔皮下实验、小鼠急性溶血性实验确定此种材料的体内安全性。结果:1.扫描电镜结果显示:经过喷砂酸蚀碱热处理后的实验组具有微纳复合结构,与骨组织表面形态更为接近,从仿生学出发,更利于骨组织愈合与抑制骨组织周围炎的发生。2.皮下植入实验结果:经过喷砂酸蚀碱热处理后的实验组与只经过喷砂酸蚀的对照组对生物组织无明显刺激,未见明显的周围组织炎。3.急性毒性实验:未见经过喷砂酸蚀碱热处理后的实验组与只经过喷砂酸蚀的对照组出现明显的生物学反应,未见明显体重下降。结论:新型表面处理钛材料在生物安全性的动物体外实验方面无异常,可以进行下一步实验。 相似文献
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在实验室内利用人工模拟方法,选择水蕹菜(Ipomoea aquatica)、泥鳅(Misgurus anguillicaudatus)、沼泽红假单胞菌(Rhodopseudomonas palustris)为工程物种,构建一套水生经济植物-水生动物-微生物复合生物修复系统进行污水修复,研究该系统中动植物生物量及水质指标的变化。结果表明,在23d的实验周期中,水体铵态氮(NH4+-N)下降96.5%,硝态氮(NO3--N)下降82.2%,总磷(TP)下降53.2%,化学需氧量(CODMn)下降24.5%。水蕹菜平均增重31.2%,泥鳅平均增重6.1%。这种复合的生物修复模式具有较好的经济效益与环境效益。 相似文献
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旨在评价α半水硫酸钙复合功能化多壁碳纳米管骨修复材料的生物相容性,为后期临床实验奠定基础。分别采用兔L929成纤维细胞与材料浸提液以及材料片剂与兔骨髓基质干细胞复合培养,在不同时段运用倒置显微镜观察,MTT检测,扫描电子显微镜分析等手段,观察材料对细胞的相容性;进行急性、亚急性毒性实验,肌肉植入实验,骨植入实验等,观察材料对组织的相容性。结果表明,L929成纤维细胞在材料浸提液中生长良好,MTT检测与对照组无显著差异(P>0.05);扫描电子显微镜结果显示,细胞能在材料上黏附并增殖;体内实验表明材料对机体无毒,无致敏性,组织相容性佳。α半水硫酸钙/碳纳米管复合材料表现出的良好生物相容性,有望在骨组织工程中得到广泛运用。 相似文献
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Inference of gene regulatory networks (GRNs) is one of the most challenging research problems of Systems Biology. In this investigation, a new GRNs inference methodology, called Entropic Biological Score (EBS), which linearly combines the mean conditional entropy (MCE) from expression levels and a Biological Score (BS), obtained by integrating different biological data sources, is proposed. The EBS is validated with the Cell Cycle related functional annotation information, available from Munich Information Center for Protein Sequences (MIPS), and compared with some existing methods like MRNET, ARACNE, CLR and MCE for GRNs inference. For real networks, the performance of EBS, which uses the concept of integrating different data sources, is found to be superior to the aforementioned inference methods. The best results for EBS are obtained by considering the weights w1 = 0.2 and w2 = 0.8 for MCE and BS values, respectively, where approximately 40% of the inferred connections are found to be correct and significantly better than related methods. The results also indicate that expression profile is able to recover some true connections, that are not present in biological annotations, thus leading to the possibility of discovering new relations between its genes. 相似文献
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对表达狂犬病毒糖蛋白的重组痘苗病毒VVM11KRG株生物学性质进行了研究,该重组病毒的特点是:(1)糖蛋白基因插入到痘苗病毒天坛株基因组HindⅢM片段中;(2)启动子为痘苗病毒天坛株P11晚期启动子;(3)不含外源lac基因。该重组病毒在CV-1细胞和鸡胚细胞上繁殖滴渡略高于另一株重组痘苗病毒VVTK11KRG,在鸡胚细胞中繁殖滴度第三天达到最高,在CV-1细胞中第二天达到最高。温度稳定性与天坛株相比没有明显改变。重组病毒在家兔皮内的毒力比亲本株(天坛株)低。间接免疫荧光和Westernblot都证明了狂犬病毒糖蛋白有良好的表达。通过Southernblot证实糖蛋白基因准确地插入到HindⅢM片段中。重组痘苗病毒启动子与部分糖蛋白基因克隆到pGEM3zf(-)质粒上,对该段DNA序列分析表明不会产生移码和融合蛋白,从而为该重组病毒的使用提供了明确的基因背景资料。 相似文献
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Martine Courtois Zoia Mincheva Françoise Andreu Marc Rideau 《Journal of enzyme inhibition and medicinal chemistry》2013,28(6):559-565
Fosmidomycin, 3-(N-formyl-N-hydroxyamido) propylphosphonic acid sodium salt, is an efficient inhibitor of 1-deoxy-D-xylulose-5-phosphate (DOXP) reductoisomerase, the second enzyme of the 2C-methyl-D-erythritol-4-phosphate (MEP) pathway notably present in Plasmodium species. We have synthesized a new series of analogues of fosmidomycin, containing a benzoxazolone, benzoxazolethione or oxazolopyridinone ring. As the MEP pathway is involved in the biosynthesis of all isoprenoids, accumulation of ajmalicine in Catharanthus roseus cells was chosen as a marker of monoterpenoid indole alkaloid (MIA) production. None of the twelve studied phosphonic esters 3 and phosphonic acids 4 affected periwinkle cell growth, but some of them (3c, 3e, 3g and 3h) showed a significant inhibition of ajmalicine accumulation: 45–85% at 125?μM. Surprisingly, this effect disappeared by conversion of 3c and 3g into the corresponding acids 4c and 4g, respectively. 相似文献
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甜瓜以营养丰富口味独特而深受世人青睐。同时,其采后病害高效、"绿色"防治药剂的缺乏也成为多年来困扰甜瓜生产的难题。本文采用直接生物测定的方法,从健康的甜瓜表面分离到1株有生防潜能的菌株X4。该菌株对引起甜瓜主要采后病害的粉红单端胞菌(Trichothecium roseum)、镰刀菌(Fusarium spp.)和链格孢菌(Alternaria alternata)的防治效果分别达到了90.6%、84.4%和67.4%;定殖实验显示,接菌4 d后该菌在瓜内数量可上升并稳定至1.1×10~6CFU/ml;通过16S rDNA测定、形态特征观察及生理生化测定结果表明该菌为Pseudomonas fluorescens biovarⅢ。 相似文献
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Biological control of snail-borne diseases: a review 总被引:1,自引:0,他引:1
C O Berg 《Experimental parasitology》1973,33(2):318-330
The need for alternatives to chemical control of snail-borne diseases and the growing interest in biological control methods are noted. Two groups of natural enemies of snails reviewed as especially promising for biological control are competing and predatory snails, and predatory fly larvae. Potentially useful natural enemies of the intramolluscan stages of trematodes include microsporidian infections and antagonistic trematode larvae. More unusual methods of biological control include the use of a toxic plant product (endod) and genetic manipulation of snails to decrease their susceptibility to trematode infection. The disappointing progress in biological control of snail-borne diseases in the past is attributed largely to delay in recognizing the need for alternatives to chemical control and to lack of interdisciplinary communication. 相似文献
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Aiping Yao Earl Zastrow Eugenia Cabot Bryn Lloyd Beatrice Schneider Wolfgang Kainz Niels Kuster 《Bioelectromagnetics》2019,40(7):458-471
The Virtual Population (ViP) phantoms have been used in many dosimetry studies, yet, to date, anatomical phantom uncertainty in radiofrequency (RF) research has largely been neglected. The objective of this study is to gain insight, for the first time, regarding the uncertainty in RF‐induced fields during magnetic resonance imaging associated with tissue assignment and segmentation quality and consistency in anatomical phantoms by evaluating the differences between two generations of ViP phantoms, ViP1.x and ViP3.0. The RF‐induced 10g‐average electric (E‐) fields, tangential E‐fields distribution along active implantable medical devices (AIMD) routings, and estimated AIMD heating were compared for five phantoms that are part of both ViP1.x and ViP3.0. The results demonstrated that differences exceeded 3 dB (?29%, +41%) for local quantities and 1 dB (±12% for field, ±25% for power) for integrated and volume‐averaged quantities (e.g., estimated AIMD‐heating and 10 g‐average E‐fields), while the variation across different ViP phantoms of the same generation can exceed 10 dB (?68% and +217% for field, ?90% and +900% for power). In conclusion, the anatomical phantom uncertainty associated with tissue assignment and segmentation quality/consistency is larger than previously assumed, i.e., 0.6 dB or ±15% (k = 1) for AIMD heating. Further, multiple phantoms based on different volunteers covering the target population are required for quantitative analysis of dosimetric endpoints, e.g., AIMD heating, which depend on patient anatomy. Phantoms with the highest fidelity in tissue assignment and segmentation should be used, as these ensure the lowest uncertainty and possible underestimation of exposure. To verify that the uncertainty decreases monotonically with improved phantom quality, the evaluation of differences between phantom generations should be repeated for any improvement in segmentation. Bioelectromagnetics. 2019;40:458–471. © 2019 Bioelectromagnetics Society 相似文献
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Krudsood S Wilairatana P Tangpukdee N Chalermrut K Srivilairit S Thanachartwet V Muangnoicharoen S Luplertlop N Brittenham GM Looareesuwan S 《The Korean journal of parasitology》2006,44(3):221-228
We conducted a study to compare the safety and tolerability of anti-relapse drugs elubaquine and primaquine against Plasmodium vivax malaria. After standard therapy with chloroquine, 30 mg/kg given over 3 days, 141 patients with P. vivax infection were randomized to receive primaquine or elubaquine. The 2 treatment regimens were primaquine 30 mg once daily for 7 days (group A, n = 71), and elubaquine 25 mg once daily for 7 days (group B, n = 70). All patients cleared parasitemia within 7 days after chloroquine treatment. Among patients treated with primaquine, one patient relapsed on day 26; no relapse occurred with elubaquine treatement. Both drugs were well tolerated. Adverse effects occurred only in patients with G6PD deficiency who were treated with primaquine (group A, n = 4), whose mean hematocrit fell significantly on days 7, 8 and 9 (P = 0.015, 0.027, and 0.048, respectively). No significant change in hematocrit was observed in patients with G6PD deficiency who were treated with elubaquine (group B, n = 3) or in patients with normal G6PD. In conclusion, elubaquine, as anti-relapse therapy for P. vivax malaria, was as safe and well tolerated as primaquine and did not cause clinically significant hemolysis. 相似文献
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In this study we successfully entrapped 5-aminolevulinic acid (ALA) in liposome, although it exists as a zwitter ion. A molar ratio of 2:1:2.5 phosphatidyle-thanolamine (PE)/cholesterol/sodium stearate represented the best condition to achieve high entrapment efficiency (29.37 ± 1.21%), and the average vehicle size was 133.6 ± 2.8 nm. After 32 days of storage, the vehicle sizes of formulations with PE series were still approximately less than 200 nm. The safety of liposomes was tested and ensured both with regard to cellular cytotoxicity and erythrocyte hemolysis. Safety studies showed that liposome formulations did not affect cell viability except when both potassium stearate and sodium oleate were added. Moreover, PE and PE/cholesterol did not damage human erythrocytes in this study. The range of the hemolytic effect caused by liposomes was 5 to 37% and the effect was dependent on the amount of sodium stearate added to the formulation. According to the release rates and skin penetration of ALA liposomes in vitro, PE/cholesterol/sodium stearate liposomes might increase skin penetration, and it was shown that penetration across the stratum–corneum (sc) layer was the rate-limiting process. Images from confocal laser scanning microscopy (CLSM) confirmed the great potency of liposomes for delivering ALA into skin. 相似文献