Bonding to industrial indirect composite blocks: A systematic review and meta-analysis

ObjectiveThe aim of this systematic review and meta-analysis was to evaluate the effect of surface conditioning methods on the bond strength of industrial indirect composite blocks (ICs).MethodsBased on the PICOS strategy, the Medline via PubMed, Embase and Web of Science (ISI – Web of Knowledge) electronic databases were searched for peer-reviewed articles in both English and Chinese, with no publication year limit. In vitro studies evaluating the effects of surface conditioning on the bond strength of ICs were selected. The meta-analysis was conducted to calculate the mean difference between surface-conditioned ICs and unconditioned controls. Subgroup analysis was performed to evaluate the different surface conditioning methods, separately for polymer-infiltrated ceramic network (PICN) material and the ICs with dispersed fillers (ICDFs). Meta-analyses were performed with a random-effects model at a significance level of 0.05.Results and SignificanceFrom 802 relevant studies, 25 were selected for full-text analysis. Nineteen studies were eligible for inclusion in this systematic review, whereas 9 studies were included in the meta-analysis. A manual search of the principal periodicals specific to the area resulted in no additional articles. The meta-analysis indicated a significant difference in bond strength between the surface-conditioned ICs and controls under both non-aged and aged conditions. The combination of mechanical and chemical conditioning yielded the highest bond strength of ICs. This meta-analysis suggests that chemical etching followed by a universal primer and alumina air abrasion followed by a silane coupling agent could be considered the best strategy for optimizing the bond strength of PICN materials and ICDFs under aged conditions, respectively.     

基于SSR标记与化学成分构建十堰地区天师栗核心种质库＊

目的 利用筛选出十堰的天师栗中高多态性SSR位点评价天师栗种质资源的遗传多样性，结合有效药用成分含量，构建十堰地区天师栗核心种质库。方法 收集十堰地区114份天师栗种质资源，以七叶树基因组为参考，采用荧光毛细管电泳筛选出高多态性SSR位点，对天师栗种质资源进行遗传多样性分析。利用HPLC测定不同种质干燥娑罗子中七叶皂苷的含量。采用最小距离逐步聚类取样策略（LDSS），根据遗传多样性保留程度初步筛选出核心种质，并对该核心种质与原始种质的遗传多样性参数进行T检验，选择与原种质差异不显著的核心种质为最佳核心种质。结果 筛选出13对高多态性SSR分子标记，遗传多样性评价结果表明十堰地区天师栗种质资源遗传多样性较高，遗传分化较小，存在着较大的基因流，114份种质资源未分为不同的亚群，周家坝和辽叶居群间具有较近的遗传亲缘关系，且周家坝居群娑罗子中的七叶皂苷A及七叶皂苷B含量普遍较高。最终筛选出的核心种质共23份，占总种质资源的20.17%，其中周家坝12份样本、辽叶6份样本、普龄5份样本。结论 将SSR分子标记与主要有效药用成分结合，采用LDSS取样策略构建十堰地区天师栗种质资源核心种质库的方法具有可行性，能够有效的保存与管理天师栗种质资源，也为当地天师栗品种改良、新品种选育研究等提供了研究基础。     

Development of a core outcome set for venous leg ulceration (CoreVen) research evaluations (protocol)

BackgroundA venous leg ulcer is a chronic leg wound caused by poor venous blood circulation in the lower limbs. It is a recurring condition causing pain, malodour, reduced mobility, and depression. Randomised controlled trials evaluating treatments for venous leg ulcers provide important evidence to inform clinical decision-making. However, for findings to be useful, outcomes need to be clinically meaningful, consistently reported across trials, and fully reported. Research has identified the large number of outcomes reported in venous leg ulcer trials, impacting both synthesis of results, and clinical decision-making. To address this, a core outcome set will be developed. A core outcome set is an agreed standardised set of outcomes which should be, as a minimum, measured and reported in all trials which evaluate treatment effectiveness for a given indication. A core outcome set has the potential to reduce research waste, improve the utility of RCTs, reduce reporting bias, facilitate treatment comparisons across different sources of evidence and expedite the production of systematic reviews, meta-analyses and evidence-based clinical guidelines.AimThe aim of this project is to develop a core outcome set for research evaluating the effectiveness of interventions for treating venous leg ulceration.MethodsThrough a scoping review of the literature on venous leg ulceration, we will firstly identify a list of candidate outcome domains (broad categories in relation to what is being measured) from randomised controlled trials and qualitative research, and outcomes (specific methods in relation to what is being measured). In two further stages, we will use the resulting lists of outcome domains and outcomes to design two online surveys. A range of stakeholders will be invited to participate in the surveys and they will be asked to indicate which outcome domains and outcomes are most important and should be considered as core in future research reports.     

Brain impedance variation of directional leads implanted in subthalamic nuclei of Parkinsonian patients

ObjectiveConventional deep brain stimulation (DBS) systems with ring-shaped leads generate spherical electrical fields. In contrast, novel directional leads use segmented electrodes. Aim of this study was to quantify the impedance variations over time in subjects with the directional Cartesia-Boston® system.MethodsImpedance records, programming settings, and clinical data of 11 consecutive Parkinsonian patients implanted with DBS directional leads in two Italian centers (Udine and Vicenza) were retrospectively evaluated. Data were collected before starting stimulation (in the operating room and at days 5 and 40) and after switching stimulation on at the successive follow-up visits (1, 6 and 12 months).ResultsDirectional leads have significantly higher impedance than ring leads. Stimulated contacts had always lower impedance compared to non-stimulated contacts. Before DBS-on, all contacts had higher impedance in the operating room, with an initial decrease five days post-surgery and a subsequent increase at day 40, more evident for directional contacts. The impedance of directional leads increased post-implantation at 1 and 6 months with a plateau at 12 months.ConclusionsThere was a significant difference between the directional and ring leads at baseline (before activation of DBS) and during follow-up (chronic DBS).SignificanceOur study reveals new information about the impedance of segmented electrodes that is useful for patient management during the initial test period, as well as during long-term DBS follow-up.     

碳纤维根管桩的研制

目的研究高强度碳纤维增强复合树脂根管桩的加工成型工艺.方法用湿法制备碳纤维预浸料,在预成型模具中预成型,然后在成型模具中经特殊的工艺进行成型,最后用车床加工成预定形状的桩钉;并测试其弯曲强度、剪切强度和碳纤维含量.结果随着碳纤维含量的增加,根管桩的弯曲强度和剪切强度均逐渐增加.碳纤维含量达到67.13%时,弯曲强度和剪切强度分别达到406MPa和653.86MPa.结论高强度的碳纤维根管桩可以满足临床需要.     

AdEasy1／Cbfa1诱导间充质干细胞向成骨细胞分化的实验研究

目的：观察核心结合因子a1（Cbfa1）对兔骨髓间充质干细胞（MSCs）向成骨细胞分化的诱导作用。方法：体外分离培养兔骨髓MSCs，用AdEasy1／Cbfa1。转染MSCs，在转染后3d,1、2、3和4周时，组织化学和免疫组化等方法检测成骨标志碱性磷酸酶和骨钙素的表达。结果：AdEasy1／Cbfa1转染后的兔骨髓MSCs表现出与成骨细胞相似的形态，并且表达碱性磷酸酶和骨钙素。结论：Cbfa1可诱导兔骨髓MSCs向成骨细胞分化。     

芳香PET树脂母粒的研制

通过丙烯酸和丙烯酸正丁酯溶液共聚合，得到丙烯酸－丙烯酸正丁酯共聚物，该树脂与环氧氯丙烷反应后再与PET树脂切片继续反应，可使PET树脂切片表面形成聚丙烯酸酯自膨润型吸油网络结构，将表面具有聚丙烯酸酯自身膨润型吸油网络结构的PET树脂切片（简称为留香剂）在油溶性香精中浸泡，香精就被吸附在留香剂表面，即得到芳香PET树脂母粒。用SEM观察了母粒的表面结构形态。     

HZ818树脂在紫杉醇初分离工艺中的应用

采用HZ818大孔吸附树脂对红豆杉浸膏中的紫杉醇成分进行吸附和洗脱试验，同时利用液质联用进行分析检测，确定了其最佳工艺参数。结果表明，HZ818树脂对紫杉醇有良好的吸附分离效果。优化工艺条件为：样品溶于体积分数40％甲醇，以1．5mL／min过柱，体积分数75％甲醇淋洗，体积分数85％甲醇以0．5mL／min洗脱，紫杉醇的质量分数从原浸膏中的1．02％提高到8．1％，回收率达98．6％。     

多官能度活性橡胶增韧环氧树脂的研究：Ⅲ.三元共混增韧环氧树脂

本文研究了双酚A对多官能度环氧基和羧基聚丙烯酸正丁酯橡胶增韧环氧树脂的影响。结果表明,加入双酚A,拉伸断裂能有大幅度提高,同时不降低弹性模量。这可能是由椽胶提高断裂伸长与双酚A提高屈服应力产生协同效应的结果。对羧基橡胶增韧的三元共混体系,拉伸断裂能随羧基官能度上升而增加。断裂面的形态研究表明,由于羧基橡胶与双酚A的酯化反应,大大减少了羧基橡胶聚集对增韧的不利影响。