大孔吸附树脂对白藜芦醇苷静态吸附性能的研究

目的 研究白藜芦醇苷在大孔吸附树脂上的静态吸附。方法 考察了吸附温度、吸附液pH值、洗脱液浓度对静态吸附性能的影响。结果与结纶 吸附温度增加,吸附液pH提高,都可以导致降低白藜芦醇苷在树脂上的吸附性能。     

Influence of various irradiation processes on the mechanical properties and polymerisation kinetics of bulk-fill resin based composites

ObjectivesTo assess the effect of irradiation time and distance of the light tip on the micro-mechanical properties and polymerisation kinetics of two bulk-fill resin-based composites at simulated clinically relevant filling depth.MethodsMicro-mechanical properties (Vickers hardness (HV), depth of cure (DOC) and indentation modulus (E)) and polymerisation kinetics (real-time increase of degree of cure (DC)) of two bulk-fill resin-based composites (Tetric EvoCeram^® Bulk Fill, Ivoclar Vivadent and x-tra base, Voco) were assessed at varying depth (0.1–6 mm in 100 μm steps for E and HV and 0.1, 2, 4 and 6 mm for DC), irradiation time (10, 20 or 40 s, Elipar Freelight2) and distances from the light tip (0 and 7 mm). Curing unit's irradiance was monitored in 1 mm steps at distances up to 10 mm away from the light tip on a laboratory-grade spectrometer.ResultsMultivariate analysis (α = 0.05), Student's t-test and Pearson correlation analysis were considered. The influence of material on the measured mechanical properties was significant (η² = 0.080 for E and 0.256 for HV), while the parameters irradiation time, distance from the light tip and depth emphasise a stronger influence on Tetric EvoCeram^® Bulk Fill. The polymerisation kinetics could be described by an exponential sum function, distinguishing between the gel and the glass phase. The above mentioned parameters strongly influenced the start of polymerisation (gel phase), and were of less importance for the glass phase.ConclusionsBoth materials enable at least 4 mm thick increments to be cured in one step under clinically relevant curing conditions.Clinical significanceThe susceptibility to variation in irradiance was material dependent, thus properties measured under clinically simulated curing conditions might vary to a different extent from those measured under ideal curing conditions.     

Selective PI3Kδ inhibitors,a review of the patent literature

Introduction: Phosphatidylinositol 3-kinase (PI3K), a lipid kinase, is the first kinase involved in, and a key component of, the PI3K/Akt/mTOR signalling pathway, and is significantly upregulated in many cancers. However, four distinct isoforms of PI3K are known with different expression patterns and different pathophysiological roles. The PI3Kδ isoform is expressed in leukocytes and has been implicated as a potential target in the development of selective inhibitors for the treatment of haematological malignancies and various inflammatory diseases.

Areas covered: This review briefly covers the understanding of the four PI3K isoforms and their roles and the inhibitors selective for either one or two isoforms that have been identified to date. It then focuses upon progress in the identification of selective PI3Kδ inhibitors focusing upon the original efforts at ICOS/Calistoga that led to the initial clinical candidates such as CAL-101. After assessing the patent filings from these companies, it considers filings from other players and how they have sought to explore similar, and structurally distinct, scaffolds in their search for selective inhibitors, and how different companies appear focused on either oncological or anti-inflammatory uses for their inhibitors.

Expert opinion: The impact of the work at ICOS is highlighted by the fact that prior to their disclosure of selective leads, no patent applications claiming selective PI3Kδ inhibitors had been filed by other companies. This disclosure, followed by the first filings by Piramed, led to an upsurge in interest with a large cluster of filings published in 2008 while half the relevant applications were published in 2010 or 2011. These efforts, and the initial clinical data on CAL-101, the leading PI3Kδ inhibitors, have also prompted a number of commercially significant deals. In addition to an increasing number of filings, the entry into the clinical development of more selective PI3Kδ inhibitors should stimulate a better understanding of the role of this specific kinase isoform.     

Large‐scale bone mineral histomorphometry – report of a simplified technique

Karantzoulis V, Liapi C & Papaggelopoulos P
(2012) Histopathology
Large‐scale bone mineral histomorphometry – report of a simplified technique Aims: The aim of this study was the development of a simplified technique for bone mineral histomorphology on large undecalcified bone samples. Established techniques, such as undecalcified bone thin sectioning, ultrathin grinding, surface‐stained block grinding and micro‐computerized tomography (CT), are expensive, time‐consuming and put very high demands on equipment, safety standards, personnel and laboratory facilities. Methods and results: The method is based on the surface‐stained block‐grinding principle; however, its novelty lies in the selection of user‐friendly, safe and low‐cost materials, equipment and digitization techniques. We describe in detail the relevant steps, as well as many practical tips for their successful implementation: accurate bone cutting in thin sections with a customized arrangement on a commercial bandsaw, defatting with sodium hypochlorite, embedding in epoxy resin blocks at room temperature, silicon carbide paper grinding, von Kossa staining, flatbed scanner digitization and image processing. Conclusion: We believe that the proposed methodology could contribute to the expansion of the study of bone tissue, as it enables the rapid examination of bone specimens on a large scale with minimal laboratory requirements and consumables costs.     

Bonding performance and interfacial characteristics of short fiber‐reinforced resin composite in comparison with other composite restoratives

The purpose of this study was to investigate the shear bond strength (SBS) and surface free‐energy (SFE) of short fiber‐reinforced resin composite (SFRC), using different adhesive systems, in comparison with other composite restoratives. The resin composites used were everX Posterior (EP), Clearfil AP‐X (CA), and Filtek Supreme Ultra Universal Restorative (FS). The adhesive systems used were Scotchbond Multi‐Purpose (SM), Clearfil SE Bond (CS), and G‐Premio Bond (GB). Resin composite was bonded to dentin, and SBS was determined after 24 h of storage in distilled water and after 10,000 thermal cycles (TCs). The SFEs of the resin composites and the adhesives were determined by measuring the contact angles of three test liquids. The SFE values and SFE characteristics were not influenced by the type of resin composite, but were influenced by the type of adhesive system. The results of this study suggest that the bonding performance and interfacial characteristics of SFRC are the same as for other composite restoratives, but that these parameters are affected by the type of adhesive system. The bonding performance of SFRC was enhanced by thermal cycling in a manner similar to that for other composite restoratives.     

光固化复合树脂临床口腔美容修复的研究

目的:探讨针对口腔美容修复中使用光固化复合树脂进行修复的临床疗效和应用价值。方法:选取2004年12月-2006年12月牙科接受治疗的128例患者,均实施光固化复合树脂分层实施塑性固化,对比不同牙科疾病的治疗结果,保持对患者1~6年的随访,观察分析长期效果。结果:45例前牙邻面龋患者治疗优秀36例(80.00%),总有效率91.11%;染色牙、四环素牙、斑釉牙40例患者治疗后优秀32例(80.00%),总有效率90.00%;15例颌面磨损患者治疗后优秀14例(93.33%),总有效率100%;15例折断牙患者治疗后优秀12例(80.00%),总有效率93.33%;8例牙缝间隙修补患者治疗后优秀7例(87.50%),总有效率100%;5例畸形牙患者治疗后优秀3例(60.00%),总有效率80.00%。其中颌面磨损修补优秀率最高,畸形牙修补优秀率最低,两者比较差异有统计学意义(P0.05)。随访显示共有10例失败,其中1例患者1年之后发生脱落,其余9例患者发生脱落时间为修复后5年。结论:光固化复合树脂用于口腔美容修复,总体临床效果较为理想。光固化复合树脂的选材较为简便,操作过程不复杂,安全性高,且长期效果不错,方便再次修复,值得推广应用。     

复合树脂与聚合瓷在牙体缺损后修复术中的应用对比

目的 对比分析复合树脂与聚合瓷在牙体缺损修复术中对牙体抵抗力的影响.方法 选取48颗正畸拔除且无龋坏的单根上颌前磨牙,将所有样本按随机数法分为A、B、C、D四组,每组均为12颗.A组不给予处理,B组接受单纯复合树脂填充修复,C组接受复合树脂覆盖牙尖填充修复,D组接受聚合瓷嵌体覆盖牙尖修复.完成修复后测试不同组别的抵抗力,并根据牙体的劈裂情况对其进行分类.结果 ①抗折强度：A组（1010.31±292.81）N,B组（809.62±205.37）N,C组（1109.47±298.74）N,D组（1140.58±285.26）N,其中C组与D组的抗折能力均优于B组（q=3.802、4.197,P＜0.05）,C组与D组间的差异比较无统计学意义（q=0.394,P＞ 0.05）.②劈裂形式：A组Ⅰ型2颗,Ⅱ型10颗;B组Ⅰ型1颗,Ⅱ型11颗;C组Ⅰ型1颗,Ⅱ型11颗;D组Ⅰ型6颗,Ⅱ型6颗.D组的劈裂形式明显优于B、C组（x2=5.042,P=0.025）.结论 复合树脂与聚合瓷嵌体均有利于提高牙体缺损修复术中牙齿的抗折强度,而采用聚合瓷牙齿的劈裂形式要优于采用复合树脂.     

Spatial fractionation of the dose in proton therapy: Proton minibeam radiation therapy

In radiation therapy, a renewed interest is emerging for the study of spatially fractionated irradiation. In this article, a few applications using spatial fractionation of the dose will be discussed with a focus on proton minibeam radiation therapy. Examples of calculated dose (1D profiles and 2D dose distributions) and biological evidence obtained so far will be presented for various spatially fractionated techniques GRID, micro- and minibeam radiation therapy. Recent results demonstrating that proton minibeam radiation therapy leads to an increase in normal tissues sparing will be discussed, which opens the door to a dose escalation in the tumour and a possibly efficient treatment of very radioresistant tumours.     

Comparison of XTT and Alamar blue assays in the assessment of the viability of various human cancer cell lines by AT-101 (−/− gossypol)

This study compared the two different commercially available in vitro viability assays: XTT and Alamar blue (AB), to detect anti-proliferative effects of AT-101, a cotton plant extract, on six different human carcinoma cell lines including: prostate (PC-3 and DU-145), breast (MCF-7 and MDA-MB-231), and ovary (OVCAR-3 and MDAH 2774) in a time- and dose-dependent manner. Cells were exposed to AT-101 in the concentration range of 2.5–40 µM for 24, 48, and 72?h. The AB assay was slightly more sensitive than the XTT assay in the evaluation of AT-101 at 24?h, suggesting that the AB assay might be used for detecting early changes in cell viability as compared to the XTT assay. Moreover, the AB assay showed less intra-assay variability as compared to the XTT. The non-toxic, non-radioactive AB metabolism assay allows rapid assessment of large numbers of samples, with simple equipment and at reduced cost for continuous monitoring of cancer cell viability, and, thus, should be accepted as a suitable alternative viability method.