不同型号大孔吸附树脂对莱菔子水提液中萝卜苷的吸附性考察

目的:研究不同型号大孔吸附树脂对莱菔子水提液中萝卜苷的纯化效果,筛选适合萝卜苷纯化的最佳型号树脂。方法:以萝卜苷的纯化效率为指标,采用高效液相色谱法测定莱菔子水提液和洗脱液中萝卜苷的含量,选择最佳型号大孔树脂。结果:X-5型大孔吸附树脂对萝卜苷的纯化率为86.2%,表明X-5型树脂更适合莱菔子中萝卜苷的纯化。萝卜苷在X-5型树脂上的吸附平衡时间为4 h。结论:采用X-5型大孔吸附树脂纯化莱菔子中萝卜苷是可行的。     

Albumin catabolism measurement by a double tracer technique in uraemic patients during a single dialytic treatment

Abstract. In order to explain the pathogenesis of protein depletion in chronic uraemia, 13 measurements of albumin catabolism were performed in uraemic patients undergoing haemo-or peritoneal dialysis treatment, during either the early phase or steady uraemic state. Catabolism was determined during a single haemo-or peritoneal dialysis by a double tracer technique (Human Serum Albumin and sodium iodide labelled with two different isotopes of iodine). The output from both albumin and iodine systems was measured in the dialysis solution flowing out from the peritoneum or artificial kidney. The radioactive iodide arising in dialysate from albumin breakdown was concentrated by the use of an anion exchange resin. Catabolic rate was three times the normal in 3 patients showing clinical features of hypercatabolism (true rapid loss of body weight) in the early phase of uraemia, or during relapse of it; albumin turnover rate returned to normal in 2 of these patients, when measured during clinical steady state conditions. This behaviour suggests highly increased catabolism, not counterbalanced by a correspondingly increased synthesis, as the cause of albumin depletion in chronic uraemia.     

复合树脂多色分层美学修复用于Ⅳ类洞的美学探讨

目的:应用多色分层复合树脂修复前牙Ⅳ类洞,观察其美学修复效果。方法:选取40颗Ⅳ类洞患牙,先经牙体预备,而后制备硅橡胶背板,比色,粘结,多色分层树脂修复,最后进行咬合调整,精细抛光,分别于术后1周、3、6、12、24月复查修复体充填效果。结果:36例充填体在24个月内的各项评价指标均达到临床满意的美学效果。结论:多色分层复合树脂修复前牙牙体,在较少磨除牙体组织的同时取得较好的临床美学效果。     

无定形磷酸钙对渗透树脂颜色稳定性及渗透性影响研究

目的    探讨渗透树脂中加入无定形磷酸钙后对其颜色稳定性及渗透性的影响。方法    收集2014年7—8月在南京大学医学院附属口腔医院口腔外科门诊因正畸治疗需要而减数拔除的离体前磨牙60颗,所有牙齿要求釉质表面光滑,颜色正常,无龋坏、隐裂、釉质发育不全及釉质脱矿。通过脱矿液建立人工龋模型,筛选出脱矿数值范围为 （35 ± 5）的40颗牙齿纳入研究。将40颗牙齿随机分为A、B两组,每组20颗。A组龋损部位用渗透树脂处理,B组龋损部位用加入纳米无定形磷酸钙的渗透树脂处理。然后,将A、B 两组再分别分为2个小组,即紫外老化组（A1组、B1组）和扫描电镜组（A2组、B2组）,每小组10颗牙齿。紫外老化组使用紫外光照射对标本进行老化,通过计算老化前后的色差值（ΔE）探究纳米无定形磷酸钙加入渗透树脂后对其颜色稳定性的影响;扫描电镜组使用扫描电镜观察标本的釉质纵剖面,探究无定形磷酸钙加入渗透树脂后对其渗透性的影响。结果    经紫外光照射后,紫外老化组的2个小组标本ΔE均随着照射时间的延长而增大;经过24 h照射后,颜色趋于稳定;照射时间相同时,2个小组标本的ΔE差异均无统计学意义（P＞0.05）。扫描电镜观察显示,A2组标本,渗透树脂可进入釉质脱矿后产生的间隙内,形成较多树脂突;B2组标本,纳米无定形磷酸钙渗透树脂虽能封闭釉质表面,但无法进入间隙或只存在少量树脂突。结论    紫外光照射可以引起树脂颜色的变化,加入纳米无定形磷酸钙不会影响渗透树脂颜色的稳定性,但会降低树脂的渗透性。     

复合树脂介质浸泡法人工老化实验及影响因素研究进展

复合树脂人工老化实验是体外模拟口腔环境,用以评价复合树脂耐老化性能的重要研究方法和手段。其中介质浸泡法是较为常用的一类人工老化实验法。现对介质浸泡法的相关原理、常用的浸泡介质以及对复合树脂重要性能所产生的影响做一综述。     

Effect of Sonic Activation on Push-Out Bond Strength of Fiber Post: An In Vitro Study

This study aimed to evaluate the effectiveness of conventional and sonic activation techniques on push-out bond strength of fiber post cemented with two different monomers containing self-adhesive resin cement (SARC). Four groups (n = 19 each) were made based on the type of SARC (Rely X U200 and Panavia SA) and technique (conventional and sonic activation). After placing the fiber post, each root was sectioned into 2 mm coronal, middle, and apical portions, and a push-out bond strength test was performed using a universal testing machine. The least push-out bond strength (13.0 ± 0.9 MPa) was found in Rely X U200 conventional technique and highest with Panavia SA sonic activation technique (15.4 ± 0.9 MPa). A significant difference was found in push-out bond strength at coronal (p = 0.002), middle (p = 0.002), and apical (p = 0.001) root sections using Rely X U200 cement with sonic activation as compared to the conventional technique. However, no difference (p > 0.05) was noticed between conventional and sonic activation techniques in Panavia SA cement at any root level. Sonic activation can be used as an adjunct with a manual technique to increase bond strength. However, it was noted that 10-MDP monomer containing SARC performed well regardless of techniques.     

Laboratory Research and Evaluation on Design and Application Performance of High-Performance Cold-Mix Resin

To improve the safety of orthotropic steel bridge decks and the construction efficiency of bridge deck pavement by enhancing the performance of pavement materials, a new-generation, high-performance cold-mix resin was prepared by carrying out the combination of micro-characteristic analysis and performance test. Meanwhile, the pavement performance and fatigue performance of high-performance cold-mix resin mixtures and hot-mix epoxy saphalt mixtures as a control group were studied experimentally. The results show that different kinds of epoxy resins show bisphenol structure in essence. The curing exothermic peak temperature of the cold-mix resin increases with the heating rate. Both the specific heat capacity (△C_P) of cold-mix resin and cold-mix resin asphalts exhibit a sudden change between −20 °C and 40 °C. In resin asphalt mixtures, cold-mix resin forms the network structure skeleton whereas the asphalt distributed in the form of tiny particles. The dosage of respective component has a significant effect on the tensile strength and elongation at break of cold-mix resin. Compared with hot-mix epoxy asphalt mixtures, cold-mix resin mixtures exhibit comparable water stability and high and low-temperature performance, as well as greater fatigue life.     

5种复合树脂不同水浴时间的压缩强度体外实验评价

目的　评价5种市场常用的复合树脂固化后经不同水浴时间压缩强度的变化。方法　将5种复合树脂（Nulite F,Filtek Z250,Filtek P60,Beautifil II,Charisma）分别制作24个圆柱体试件并固化,每种复合树脂再分为4组,每组6个样本,其中1组浸泡于37 ℃蒸馏水浴1 h,另外3组分别接受蒸馏水浴1 d、7 d和30 d,测试各组的压缩强度值。测试结果以One-way ANOVA和LSD法统计学检验。结果　水浴1 d后,各品牌复合树脂的压缩强度值均有明显提高。树脂试件经1 h水浴时,Filtek Z250的平均压缩强度最高,Beautifil II其次;1 d和7 d水浴后,Filtek P60 和Filtek Z250的压缩强度最高,Beautifil II居中;30 d水浴后,Filtek Z250的压缩强度最高。结论　Filtek P60和Filtek Z250具有较好的抗压性能,复合树脂充填修复一段时间后压缩强度值才能达到最大。     

微瓷树脂嵌体和复合树脂嵌体微渗漏的对比研究

目的 对比研究1种微瓷聚合树脂嵌体和另外3种复合树脂嵌体的边缘微渗漏情况,为临床选择嵌体材料提供参考。方法 将80颗健康离体上颌前磨牙随机分为8组,每组10颗,嵌体窝洞制备后,分别用微瓷聚合树脂Ceramage（C）和复合树脂Brilliant new line(B)、Z350(Z)、P60(P)间接法制成嵌体,每种材料2组,使用即刻牙本质封闭(immediate dentin sealing,IDS)/延时牙本质封闭(delayed dentin sealing,DDS)技术粘结,冷热循环品红染色后,用金刚砂片将实验牙切开,体视镜下观察微渗漏。结果 4种树脂嵌体龈壁与轴壁微渗漏无显著性差异（P>0.05）,各IDS组与DDS组微渗漏亦无显著性差异（P>0.05）。无论龈壁还是轴壁,采用IDS或DDS粘结技术,4种材料之间皆有显著性差异（P<0.05）并且渗漏情况一致。微渗漏从小到大依次均为C、Z、P、B。结论 单从微渗漏方面评价,Ceramage和Z350均为制作树脂嵌体的良好选择。