生物医用植入体钛基合金及其表面生物活性氧化层的制备:机遇与挑战

钛及其合金因其优异的力学性能和良好的生物相容性,长期以来一直被用作植入材料.尽管如此,研究人员和行业仍在积极寻求更好的合金,因为仍有一些迫切的问题需要关注,包括:(1)由于种植体材料与人体骨组织的弹性模量不匹配而导致的应力屏蔽问题;(2)Ti合金长期使用后有害离子的释放问题;(3)钛合金表面生物活性低而导致愈合过程延长...     

EFFECT OF SODIUM METABISULFITE ADDITION AND BAKING TEMPERATURE ON MAILLARD REACTION IN BREAD

ABSTRACT

In this study, the effect of sodium metabisulfite (SMBS) doses (0, 25, 50, 100 mg/kg dough) and baking temperatures (200, 230 and 250C) on the physical, chemical and sensory properties of bread were researched to reduce 5‐hydroxymethyl‐2‐furfural (HMF) and acrylamide contents. HMF and acrylamide contents of bread crust were decreased significantly by increasing SMBS dose and decreasing baking temperature. The HMF (137.29 mg/kg) and acrylamide (671.44 µg/kg) contents of bread crust were decreased by 33 and 67%, respectively by addition of 100 mg/kg SMBS. The maltol content of bread crusts were significantly affected by baking temperature, and were 7.19, 10.23 and 22.69 mg/kg in breads baked at 200, 230 and 250C, respectively. No HMF, acrylamide and maltol were detected in the bread crumb. The sulfur dioxide content of the crust and crumb of control bread was 6.99 and 10.69 mg/kg, and increased by 49 and 59%, respectively at 100 mg/kg SMBS dose. All breads were evaluated as acceptable by a sensory panel.

PRACTICAL APPLICATIONS

Since Maillard reaction products such as acrylamide and 5‐hydroxymethyl‐2‐furfural (HMF) are known as toxic compounds, mitigation of these compounds is important subject for health and nutrition. There is not an efficient method to prevent the formation of acrylamide and HMF in bread crusts comparison with potato crisps. The purpose of this research is to slow down Maillard reaction by addition of sodium metabisulfite in bread‐making process. As a result of this research, acrylamide and HMF content of bread crusts decreased by 33 and 67%, respectively with acceptable sensory evaluation.     

Experimental investigation of shared storage assignment policies in automated storage/retrieval systems

In this study, two shared storage assignment policies are compared in an Automated Storage/Retrieval System (AS/RS) by using computer simulation. The AS/RS is assumed to operate under a continuous review, order quantity, reorder point inventory policy. The average travel time of the AS/R machine for storing and retrieving products is used as the main performance measure. Sensitivity of the system to product variety, inventory replenishment lead time, and demand rate is investigated, as well as the effects of the inventory policy and the product classification technique used. Our main conclusion is that the turnover-based policy, in general, outperforms the duration of stay-based policy. However, the' difference between the performance of the two policies becomes insignificant under certain conditions.     

Rapid Species Identification of Cooked Red Snapper Using Isoelectric Focusing

A rapid method using isoelectric focusing (IEF) was developed to identify species of cooked snapper. The IEF protein band patterns of red snapper as impacted by two extraction systems (water and 8M urea), various cooking times (raw, 5, 10, 15, 20, 25 and 30 min) and cooking methods (microwave, bake, steam, broil, deep fry, and pan fry) were investigated. Samples were desalted and cleaned using a 10-sec rinsing procedure. The characteristic IEF protein pattern of red snapper was reproducible for various cooking conditions. Both 8M urea and water could be used as extractant of snapper sarcoplasmic proteins. IEF protein bands in the acidic region of the polyacrylamide gel (pH 3.5-9.5) were useful as markers for species identification.