Affects and personality: A study with university students

Objective

Analyze the relation between both these variables (affects and personality).

新型多微孔细菌纤维素组织工程支架材料的制备及表征

目的 当细菌纤维素（BC）作为组织工程支架时,动物细胞在其纳米级网络中无法很好延展和分化生长,因此无法获得完美的生物医学应用.为此,本研究开发出一种新型绿色环保方法制备出孔径分布在50～800 μm的多微孔BC材料,以期今后用作组织工程支架.方法 将BC水凝胶浸入过氧化氢溶液中,并加入不同质量的亚氯酸钠固体,氧化反应瞬间发生,产生的大量气体在BC水凝胶内部形成了50～800 μm的气孔.结果 气孔直径分布可随过氧化氢-亚氯酸钠的体积质量比不同而变化.红外光谱分析表明反应过程中无纤维素被氧化.多微孔BC水凝胶的含水率与原BC水凝胶相似,但其杨氏模量为26.1kPa,低于致孔前的69.9 kPa.噻唑蓝（MTT）实验结果初步表明多微孔BC水凝胶材料更适宜细胞成长,具有成为骨组织工程支架的潜力.结论 该制备方法不仅简单易行,实验原料安全性好,而且有较广阔的应用前景,可推广用于其他凝胶材料致孔,适合工业化大规模生产.     

Microstructural characterization and fracture behavior of a microhybrid and a nanofill composite

OBJECTIVES: To characterize the microstructure and composition of two different composites, and to determine their influence on the physical properties and fracture behavior. METHODS: The microstructure and composition of a microhybrid (Filtek Z250-Z2) and a nanofill (Filtek Supreme-SU) composite were analyzed using scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS). Filler wt% was determined by thermogravimetric analysis. Hardness (H) and degree of conversion (DC) were evaluated at top and bottom surfaces of 2-mm thick specimens, and the dynamic elastic modulus (E) was determined with ultrasonic waves. Bar specimens (n=30) were subjected to flexure loading and flexural strength (sigmaf) was calculated (MPa). Fractographic analysis (FA) was performed to determine the fracture origin (c) for calculation of fracture toughness (KIc), and these results were compared to those from the single edge notch beam (SENB) method. Results were statistically analyzed using two-way ANOVA, Student's t-test and Weibull analysis (alpha=0.05). RESULTS: Z2 had higher filler wt%, H, E and DC at 2-mm depth as compared with SU. The fracture behavior (sigmaf and KIc) and the structural reliability (m) of the composites were similar. Results of KIc tested by SENB or calculated from fracture surfaces from flexure testing were similar. SIGNIFICANCE: The microstructural organization of the composites determines their physical properties, in spite of the similar filler content. In contrast, the microstructure did not influence the fracture behavior and the structural reliability of these highly filled composites. FA was shown to be a reliable method for determining the KIc of composites.     

聚合物空心纳米球及其在药学领域的应用

概述聚合物空心纳米球的制备和表征检测方法以及作为给药载体在药学领域的应用.聚合物空心纳米球用作载药系统具有独特优势,除了具有靶向性和控、缓释性,它还可提高载药量、药物生物利用度及系统稳定性.     

紫球藻凝集素的糖蛋白特性

从紫球藻中纯化出紫球藻凝集素(PCL)。经测定该凝集素是一种分子量为39.6kD的糖蛋白,分子中含有28.4%的中性糖。氨基酸组成中缬氨酸(Val)含量最高,异亮氨酸(Iie)含量最低。PLC能凝集兔与猪的红细胞,其凝血活性可被某些单糖或二糖及胃粘蛋白所抑制。PLC对温度变化较为敏感,对酸、碱处理有较好的稳定性。     

果糖-1,6-二磷酸钠盐的结晶及结构分析

采用酒精-媒晶剂体系制备果糖-1，6-二磷酸钠盐（FDP），并对其最佳结晶工艺条件进行了研究。在此条件下，FDP的结晶收率和产品纯度分别为95％和99．3％。通过元素分析、红外光谱和核磁共振碳谱等对产品结构进行了研究分析。     

Ultrasonic tissue characterization of the myocardium in anorexia nervosa

AIM: To determine the systodiastolic variations in the integrated backscatter (IBS) signal of the myocardium in patients with anorexia nervosa. METHODS: 25 young women (aged 22.4 +/- 4.3 y) with overt anorexia nervosa, compared with 25 age-matched thin and 25 age-matched control women with body mass index >20 kg m(-2), underwent either conventional two-dimensional echocardiography or analysis of IBS cyclic variations. RESULTS: Compared with thin and control subjects, anorectic patients showed reduced left ventricular mass (LVM: 82.9 +/- 17.1 vs 119.9 +/- 13.8 and vs 126.12 +/- 16.4 g, p < 0.0001; LVM indexed 21.4 +/- 3.3 vs 29.4 +/- 2.5 and vs 31.2 +/- 3.1 g m(-2.7), p < 0.0001), and IBS cyclic variations (septum: -0.49 +/- 2.18 vs 6.86 +/- 1.3 and vs 6.61 +/- 1.74 dB p < 0.0001; posterior wall: 2.77 +/- 2.12 vs 7.15 +/- 2.12 and vs 7.48 +/- 2.23 dB, p < 0.01). CONCLUSION: Anorexia nervosa is associated with a significant reduction in the cyclic variation in IBS, which is also related to left ventricular hypotrophy. Ultrasonic tissue characterization could give an objective approach for the detection of myocardial structural properties and represent a preclinical index of myocardial dysfunction in anorexia nervosa.     

医疗器械生物材料表征和化学性能检测的重要性

医疗器械生物学评价国际标准ISO10993第18和19部分作为医疗器械和生物材料生物学评价的重要组成部分越来越受到重视,在安全性评价中的重要一环就是材料的表征和材料中可萃取和迁移成分的鉴定。本文讨论那些试验可以满足这些要求。