Effect of Extraoral Aging Conditions on Mechanical Properties of Maxillofacial Silicone Elastomer

Purpose: The purpose of this study was to investigate the effect of extraoral human and environmental conditions on the mechanical properties (tensile strength and modulus, elongation, tear strength hardness) of maxillofacial silicone elastomer. Materials and Methods: Specimens were fabricated using TechSil‐S25 silicone elastomer (Technovent Ltd, Leeds, UK). Eight groups were prepared (21 specimens in each group; eight tensile, eight tear, five hardness) and conditioned differently as follows (groups 1 through 8): Dry storage for 24 hours; dry storage in dark for 6 months; storage in simulated sebum solution for 6 months; storage in simulated acidic perspiration for 6 months; accelerated artificial daylight aging under controlled moisture for 360 hours; outdoor weathering for 6 months; storage in antimicrobial silicone‐cleaning solution for 30 hours; and mixed conditioning of sebum storage and light aging for 360 hours. The conditioning period selected simulated a prosthesis being in service for up to 12 months. Tensile and tear test specimens were fabricated and tested according to the International Standards Organization (ISO) standards no. 37 and 34, respectively. Shore A hardness test specimens were fabricated and tested according to the American Standards for Testing and Materials (ASTM) D 2240. Data were analyzed with one‐way ANOVA, Bonferroni, and Dunnett's T3 post hoc tests (p < 0.05). Weibull analysis was also used for tensile strength and tear strength. Results: Statistically significant differences were evident among all properties tested. Mixed conditioning of simulated sebum storage under accelerated artificial daylight aging significantly degraded mechanical properties of the silicone (p < 0.05). Conclusions: Mechanical properties of maxillofacial elastomers are adversely affected by human and environmental factors. Mixed aging of storage in simulated sebum under accelerated daylight aging was the most degrading regime. Clinical significance: Accelerated aging of silicone specimens in simulated sebum under artificial daylight for 12 months of simulated clinical service greatly affected functional properties of silicone elastomer; however, in real practice, the effect is modest, since sebum concentration is lower, and daylight is less concentrated.     

内科杂病验案选释(五)

13 2型糖尿病兼胃脘痛案袁某某,女,58岁。2012年5月7日初诊。脘腹部轻微疼痛兼有空虚感近1年。患者于2012年4月23日在某某地市级医院做胃镜检查诊断为:非萎缩性胃炎伴糜烂;2011年7月在某某省级医院确诊患有2型糖尿病,经西药治疗得以控制,并长期服用二甲双胍维持。大便一般1~2 d 1次,时常干结,小便可,饮食亦可,舌苔白腻,脉细弦。辨证:素体气阴两虚,兼脾胃不和,气滞血瘀湿阻。治法:益气养阴和胃,理气活血化湿。方药:香砂六君子汤、百合汤、良附丸、丹参饮合方加减。党参10 g,茯苓15 g,白术10 g,广木香5 g,砂仁5 g,百合15 g,     

中药材“发汗”对药材质量的影响

“发汗”是一种独特的产地初加工技术,传统认为,“发汗”有利于药材干燥,易于药材贮藏,能提升药材的质量。通过查阅古代书籍和现代文献对“发汗”的历史沿革进行了考察,归纳了“发汗”方法,分析总结了“发汗”对药材性状、化学成分、药效活性、毒理反应的影响。结果表明,“发汗”这一产地加工的方法是近代在实践中逐渐发展起来的,主要有直接堆积法和加热法两种,“发汗”过程易对药材中的酶产生影响,具体表现在对药材中酚酸类成分、皂苷/苷类成分及环烯醚萜类成分的影响上,“发汗”药材在颜色上的改变也多是源于这些成分含量上的变化;“发汗”对药材药效活性影响的报道较少,还应做进一步的研究,为“发汗”的合理性及科学性提供试验依据。     

滋阴降火方治疗绝经综合征阴虚火旺证

目的:观察中医滋阴降火方对绝经综合征阴虚火旺证女性患者临床症状的改善作用,探讨其作用机制。方法:将符合绝经综合征阴虚火旺证诊断标准的患者随机分入治疗组和对照组,各30例,治疗组予滋阴降火方,对照组予安慰剂,4周为1个疗程,共3个疗程。观察两组用药前后主症潮热、出汗计分,Kupperman症状积分,阴虚火旺证症状积分变化。结果:治疗组治疗后主症潮热、出汗发作次数及程度均下降,有统计学意义(P<0.05);对照组变化无统计学意义;治疗组与对照组治疗后Kupperman症状及阴虚火旺症状积分均下降,但治疗组对总体症状的改善显著优于对照组(P<0.01)。结论:滋阴降火方能缓解阴虚火旺型绝经综合征患者的临床综合症状,对主症潮热、出汗的缓解作用尤为明显,能够提高患者的生活质量。     

生脉散合牡蛎散治疗小儿多汗症120例临床观察

目的：观察生脉散合牡蛎散加减治疗小儿多汗症的临床疗效。方法：选择临床小儿汗证患儿220例,并对其中120例在常规的维生素D钙剂治疗同时加用生脉散合牡蛎散加减治疗。余下的100例单纯给于维生素D、钙剂治疗,比较两组临床疗效。结果：治疗组有效率90％,对照组总有效率30％。两组比较有统计学意义（P〈0．05）。结论：生脉散合牡蛎散治疗小儿多汗症疗程短、疗效高、费用低、操作简单,明显优于西药单纯、常规的补钙疗法,具有一定的推广价值。     

强壮灵合剂治疗小儿表虚不固多汗症130例临床观察

[目的]观察强壮灵合剂治疗小儿表虚不固多汗症的临床疗效。[方法]对130例表虚不固多汗症患儿按年龄给予不同剂量强壮灵合剂口服,2次/d,7 d为1个疗程,2个疗程后统计疗效。[结果]强壮灵合剂可明显减少患儿出汗次数、减轻症状。130例中痊愈73例,好转44例,有效13例,总有效率90%。[结论]强壮灵合剂治疗小儿多汗症表虚不固型疗效确切,且可防治小儿感冒。     

《伤寒论》“控水论”之汗法探微

《伤寒论》中包含的治法众多,但以汗法和下法最为详细,间接论述吐法也较多,此三法是其他诸法的基础,加上止汗、止下和止吐三种对应治法,水液的调控便贯穿了汗、吐、下三法的始终。掌握了对人体水液的调控,也就掌握了汗、吐、下三法,也就掌握了伤寒病的基本处理方法和思路。     

隐匿型冠心病阵发性出汗与心肌缺血关系探讨

目的：探讨隐匿型冠心病阵发性出汗与心肌缺血之间的关系。方法：从有阵发性出汗且经冠状动脉造影确诊为冠心病的病例中，回顾Holter检查，了解心肌缺血发作与阵发性出汗的关系。结果：13例病人作Holter检查期间，阵发性出汗28例次，其中23次有心肌缺血发作。结论：隐匿型冠心病病人突然出汗与心肌缺血发作有相关性。     

厚朴"发汗"前后药材颜色及气味差异的数值化研究

目的:采用色差仪及电子鼻对厚朴“发汗”所产生的性状变化进行数值描述.方法:以“发汗”厚朴与未“发汗”厚朴为研究对象,采用色差仪和电子鼻测量其颜色特征参数和气味特征参数,并最终建立判别模型.结果:在药材颜色方面,建立了基于L*,a*,b *色度空间的“发汗”与未“发汗”厚朴颜色特征参数模型,“发汗”厚朴双侧90％参考值范围L*(52.22 ～59.42),a*(5.36 ～7.68),b*(22.04 ～27.05);未“发汗”厚朴双侧90％参考值范围L*(38.42 ～47.31),a*(9.63 ～11.85),b*(18.48 ～25.53);在药材气味方面,主成分分析及偏最小二乘法分析结果表明,“发汗”厚朴与未“发汗”厚朴存在显著性差异.结论:厚朴“发汗”前后药材颜色及气味差异均可根据色差仪和电子鼻测得的厚朴颜色和气味特征参数以数值的形式表述.     

《伤寒论》第85～89条禁汗发微

《伤寒论》第85～89条禁汗诸文，在《金匮要略》中复见，足证其义非寻常。条文组合排列，发人深思。条文复出，启人聪明。条文变证，诲人机圆。未列方治，悟人法活。该禁诸条，言简义赅，富于哲理。不但遣人以规矩，更上乘者，实欲启悟心扉，推后学于登辨治之堂室。