Making yttria-stabilized tetragonal zirconia translucent

ObjectiveThe aim of this study was to provide a design guideline for developing tetragonal yttria-stabilized zirconia with improved translucency.MethodsThe translucency, the in-line transmission in particular, of 3 mol.% yttria-stabilized tetragonal zirconia (3Y-TZP) has been examined using the Rayleigh scattering model. The theory predicts that the in-line transmission of 3Y-TZP can be related to its thickness with grain size and birefringence the governing parameters. To achieve a threshold value of translucency, the critical grain size of 3Y-TZP was predicted for various thicknesses (0.3–2.0 mm). The threshold value was defined by a measured average in-line transmission value of a suite of dental porcelains with a common thickness of 1 mm. Our theoretical predictions were calibrated with one of the very few experimental data available in the literature.ResultsFor a dense, high-purity zirconia, its in-line transmission increased with decreasing grain size and thickness. To achieve a translucency similar to that of dental porcelains, a nanocyrstalline 3Y-TZP structure was necessitated, due primarily to its large birefringence and high refractive index. Such a grain size dependence became more pronounced as the 3Y-TZP thickness increased. For example, at a thickness of 1.3 mm, the mean grain size of a translucent 3Y-TZP should be 82 nm. At 1.5 mm and 2 mm thicknesses, the mean grain size needed to be 77 nm and 70 nm, respectively.SignificanceA promising future for zirconia restorations, with combined translucency and mechanical properties, can be realized by reducing its grain size.     

Factors related to memory absence and delusional memories in patients in intensive care units managed with light sedation

ObjectivesCurrently, light sedation is typically given to patients in intensive care units and studies have not extensively examined the factors related to absences or abnormalities of their memories. We, therefore, analysed the factors related to the absence/abnormalities of patients’ memories in intensive care units.Research MethodologyA secondary analysis of previously collected survey data examining patients’ experiences in an intensive care unit was undertaken (n = 405; women = 38%; median age = 70 years). To observe absent or distorted memories, patients were interviewed after leaving the intensive care unit. We analysed key factors through content analysis of the interviews and field notes.SettingThe intensive care unit of a university hospital. Main outcome measure: Patients’ absent or distorted memories after leaving the intensive care unit.ResultsHalf the patients reported an absence of memories. This was associated with old age and with longer duration of mechanical ventilation. Absent or fragmentary memories were not distressing. Fragmentary and fearful intensive care unit memories were associated with being older. Delusional memories, some of which reflected actual events, were present in 3% of patients.ConclusionAbsence of memories were not distressing, delusional memories occurred less and these memories could comprise of an event in ICU that is difficult for patients to understand.     

养血饮颗粒中黄芪甲苷的含量测定

目的:建立高效液相色谱法测定养血饮颗粒中黄芪甲苷的含量,提高养血饮颗粒质量标准,为养血饮颗粒制剂评价研究奠定基础。方法:采用Agilent 1260高效液相色谱仪,Agilent蒸发光检测器(低温型);以乙腈-水(38∶62)为流动相;检测波长为270 nm;空气发生器为0.4 MPa;漂移管温度为50℃对黄芪甲苷进行含量测定。结果:黄芪甲苷在0.66~6.63μg范围内线性关系良好,回收率为97.81%(RSD=3.94%,n=9),精密度、稳定性、重现性均符合要求。结论:该方法可以用于养血饮颗粒中黄芪甲苷的含量测定。     

面部鳞状细胞癌患者联合应用钬激光和光动力的疗效观察

目的探究联合应用钬激光和光动力治疗面部鳞状细胞癌(SCC)患者的临床疗效,为临床有效控制面部SCC的恶化乃至治愈提供理论依据。方法2016年1月-2017年12月,将48例面部SCC患者进行对照研究,根据治疗方式的不同分为对照组(光动力局部照射治疗)和试验组(光动力联合钬激光照射治疗),每组各24例。比较2组患者治疗后15 min、30 min、60 min时鳞癌细胞温度的统计学差异,比较2组患者临床疗效的统计学差异。结果2组患者鳞癌细胞温度0 min差异无统计学意义,试验组患者15 min、30 min、60 min时鳞癌细胞温度显著高于对照组患者(P<0.05)。试验组患者临床疗效显著优于对照组患者,且有效率显著高于对照组患者(P<0.05)。结论联合应用钬激光和光动力对面部SCC患者展开治疗,可以有效的缩短患者皮损缩小以及消失的时间,同时增加鳞癌细胞温度,临床疗效明显高于单纯使用钬激光进行治疗,值得临床推广。     

丁苯酞对局灶性脑缺血大鼠脑水肿和梗死周围组织磷酸化肌球蛋白轻链表达的影响

目的 探讨丁苯酞对局灶性脑缺血大鼠脑水肿和梗死周围组织磷酸化肌球蛋白轻链表达的影响.方法 成年雄性Sprague-Daw ley大鼠212只,按随机数字表法分为假手术组（n=12）、脑缺血组（n=l00）和丁苯酞组（n=100）（40 mg/kg,1次/d,灌胃）;脑缺血组和丁苯酞组再分为6h、12 h、ld、3d和7d组（每个时间点各20只）.光化学法建立大鼠局灶性脑缺血模型,2,3,5-氯化三苯基四氮唑（2,3,5-triphenyltetrazolium chloride,TTC）染色法检测脑梗死体积（n=5）,干湿重法检测脑组织含水量（n=5）,免疫组化（n=5）和蛋白质印迹法（n=5）检测梗死周围皮质p-MLC蛋白表达.结果 TTC染色显示,假手术组未见梗死灶,丁苯酞组各时间点梗死体积均显著性小于脑缺血组相同时间点（P均＜0.05）.干湿重法显示,缺血组和丁苯酞组脑组织含水量均显著性高于假手术组（P均＜0.05）,但丁苯酞组各时间点脑组织含水量均显著性低于脑缺血组相同时间点（P均＜0.05）.免疫组化和蛋白质印迹均显示,缺血组和丁苯酞组脑组织梗死周围皮质p-MLC表达均较假手术组显著性上调（P均＜0.05）,但丁苯酞组各时间点脑组织梗死周围皮质p-MLC表达均显著性低于缺血组相同时间点（P均＜0.05）.结论 丁苯酞可通过减轻脑缺血引起的p-MLC表达上调而减轻脑水肿,进而缩小梗死体积,从而发挥神经保护作用.     

N-乙酰基转移酶基因多态性与帕金森病相关性研究

目的　探讨N -乙酰基转移酶 (NAT2 )基因多态性与散发性帕金森病 (Parkinson’sdisease ,PD)的关系。方法　应用自动实时荧光Light-Cycler技术 ,分析 88例PD患者和 112例健康人NAT2 4个位点的基因多态性 ,比较PD患者与对照组间频率差异。结果　早发PD组NAT2 6A等位基因频率与对照组比较有显著性差异 (P <0 .0 5 ) ,使患PD的危险度提高了 2 .0 8倍 (P <0 .0 5 ) ,NAT2 5A和NAT2 7A/B等位基因频率与对照组比较无显著性差异 (P >0 .0 5 ) ;晚发PD组NAT2 4个多态位点各等位基因频率与对照组比较无显著性差异 (P >0 .0 5 ) ;未检测到NAT2 14A等位基因。结论　NAT2 6A等位基因可能主要与早发PD的易感性相关 ,并参与了神经毒素的解毒。     

细丝弓技术矫治安氏Ⅱ类1分类拔牙患者在两种矫治器中的疗效比较

目的:比较细丝弓技术矫治安氏Ⅱ类1分类拔牙患者使用MBT直丝弓矫治器和Begg矫治器的矫治效果.方法:28例上颌需要最大支抗的安氏Ⅱ类1分类错(牙合)患者(男10例,女18例),拔除4颗第一前磨牙,分为MBT直丝弓矫治器(14例,A组)和Begg矫治器(14例,B组)2组,采用细丝弓矫治技术,对治疗前后患者头颅侧位X线片进行头影测量,并对结果作统计学分析.结果:治疗结束时,上颌切牙压低A组为(0.18±0.32) mm,B组为(0.77±0.91) mm(P＜0.05);2组患者矫治前后其余头影测量项目差值均无统计学意义(P＞0.05).结论:安氏Ⅱ类1分类错(牙合)拔牙患者应用细丝弓技术矫治,Begg矫治器对上颌前牙垂直向控制优于直丝弓矫治器,其他方面2种矫治器均可收到同样的疗效.     

低密度聚乙烯薄膜对牙科光固化机光能输出的影响

目的评估低密度聚乙烯(LDPE)薄膜材料对光固化机输出能量的影响是否最终会影响树脂的固化效果。方法对市售的3种品牌的低密度聚乙烯薄膜材料进行测试,每种材料有普通型和微波型两类,检测其使用前后光固化机输出辐照度的变化,计算材料的透光率,评估其对光能输出的影响,并与专用光导棒套(SDI)进行对比。结果用于对照的专用SDI的透光率为92%,三种品牌的普通型薄膜材料透光率分别为94.8%、95.8%和94.4%,而三种品牌的微波型薄膜材料透光率分别达到83.8%、85.6%和86.2%。结论使用普通薄膜材料作为光导棒与口腔环境的隔离屏障,不会对光能输出产生较大影响,可以成为一种在光固化治疗过程中防止交叉感染的一次性使用避污薄膜材料。