GB150-2011中圆筒开孔补强设计的分析法

GB 150-2011版设计篇第6.6节圆筒径向接管开孔补强设计的分析法是在该版国家标准中新加入的内容,它将开孔补强设计的适用范围扩大至开孔率达0.9,是根据我国自主研发的薄壳理论解得到的应力分析方法.文中简要阐述了其理论基础与设计准则,所采用设计准则的依据,并给出了与其他设计方法的比较.     

Relationship of multidrug-resistant gene and extended-spectrum carbapenem-resistance in <i>Staphylococcus aureus</i>

The aim of this study was to determine the relationship between phenotypic antimicrobial susceptibility patterns and extended-spectrum, carbapenem-resistance genes. A total of 109 clinical Staphilococcus aureus strains were subjected to 19 antimicrobial susceptibility tests. Resistance to methicillin (mecA), penicillin (blaTEM), and tetracycline (tetM) was detected. We compared the presence of the blaTEM genes with extended-spectrum, carbapenem-related genes and identified the types of SCCmec genes. Of 109 clinical S. aureus strains, 62 (56.88%) had methicillin resistance and 60 strains carried mecA. The prevalence of blaTEM and tetM genes was 81.65% and 37.61%, respectively. The most predominant SCCmec type was SCCmec type II 28/60 (46.67%), in 60 mecA-positive methicillin-resistant S. aureus (MRSA) isolates. The SCCmec prevalence rates were type IVA 30.00% (18/60), type IVb 8.33% (5/60), type IVd 6.67% (4/60), and non-typable 8.33% (5/60). Sixty of the 109 (55.05%) MRSA isolates were positive for extended-spectrum carbapenems (31/60) (51.67%), cephalosporins 40/60 (66.67%) and carbapenems 31/60 (51.67%). The predominant SCCmec type II demonstrated more carbapenem-resistance than the IVA, IVb and IVd types.     

Biogenic Amines in the Flesh of Sailfish (Istiophorus plafypferus) Responsible for Scornbroid Poisoning

Sailfish fillets were involved in a 1994 food poisoning outbreak in westem Taiwan. Samples were collected from the victims’residues and from retail and wholesale suppliers. They were analyzed for amines by a gradient elution system of HPLC. Tryptamine, histamine, spermine, trimethylamine, spermidine, and cadaverine were found; other amines were not detectable. The concentration of histamine was higher than 100 mg/100g which was assumed as the toxic level. The allergy-like symptoms of the victims along with the high content of histamine in the sailfish they had eaten were reasonable evidence that the food poisoning was directly associated with histamine intoxication.     

Retention of Passion Fruit Juice Compounds by Ultrafiltration

Recovery of passion fruit juice compounds by ultrafiltration was studied using a tubular system equipped with a 25,000 dalton nominal M.W. cut-off membrane. The retentivities of many important flavor compounds, such as β-ionone, ethyl hexanoate, hexyl butyrate and hexyl hexanoate, were 80% or higher when operating at 20°C and 12 bar of pressure. Retentivities of sugars and organic acids were between 10 to 40%. The retentivities increased as the concentration ratio increased.     

Differences in the Lipid Composition of Fresh Water Prawn (Macrobrachium rosenbergii) and Marine Shrimp

Total lipid content of fresh water prawn (FWP, Macrobrachium rosenbergii) was found to be greater than that of marine shrimp (3.18 vs 1.33%). This was due to the much higher levels of triglycerides in FWP as compared to marine shrimp. The ω6 polyunsaturated fatty acids (PUFA) predominated in FWP lipids, whereas the w3 PUFA predominated in marine shrimp, primarily due to the greater concentration of linoleic acid in FWP lipids (16.3 vs 2.9%). The triglycerides of both species contained considerable amounts of PUFA and FWP has a high triglyceride content. This may contribute, in part, to the shorter shelf-life of Macrobrachium as compared to marine shrimp.     

东亚金融危机的定量分析

为探求东亚金融危机发生和传染的内部和外部原因,利用模型、ＧＡＲＣＨ模型等定量方法对影响危机的主要经济因素、危机的传染效庆和１９９７年泰国金融危机传染的原因进行了分析。最全,讨论了国家在金融市场开放过程中的宏观经济政策,提出了防止今后危机重现应采取的措施和危机发生后各国之间的“合作对策”。     

FORMATION OF HETEROCYCLIC AMINES IN MEAT EMULSION EXTENDED WITH SOY PROTEIN

Formation of heterocyclic amines (HAs) during heating of meat emulsions at selected temperatures was studied to determine the influence of soy protein and fat contents on yields of HAs. Meat emulsion with two different fat contents, 6% (low) and 19% (high), and with two soy protein contents, 0% (none) and 10%, were used in the study. The emulsions were heated at temperatures of 180 and 200C for times varying from 0 to 40 min. HAs namely IQx (2-amino-3-methylimidazo[4,5-f]quinoxaline), MelQx (2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline), and PhIP (2-amino-1-methy-6-phenylimidazo[4,5-b]pyridine) were identified and quantified in the meat emulsions. Concentrations of IQx were from 0 to 8.26 ng/g of emulsion; MeIQx concentrations were from 0 to 14.73 ng/g and PhIP concentrations were from 0 to 2.48 ng/g. Yields of the HAs depended on temperature, time, soy protein and fat contents. Formation of the HAs in the meat emulsions after an initial lag period followed first order kinetics. Increasing soy protein content decreased the maximum concentrations of IQx and MeIQx formed at the different heating condition.     

Microenvironmental regulation of stem cells injected in the area at risk of neurodegenerative diseases

The complex mechanism of degenerative diseases and the non-specific modulation of regenerative targets are topics that need to be elucidated in order to advance the use of stem cells in improvement of neurodegenerative diseases. From pre-transplantation through post-transplantation, there are many changes in the conditions, both inside and outside of the stem cells that have not been carefully considered. This has hindered development in the field of cell therapy and regeneration. This viewpoint highlights the potential implications of intracellular and extracellular alterations of stem cells in transplanted areas at risk of neurodegenerative disease.     

An improved version of the production switching heuristic for the aggregate production planning problem

The production switching heuristic (PSH) is recognized as an effective solution method for the aggregate production planning problem in industries where production is limited to discrete levels. However, we find that the PSH is not sufficiently responsive to demand fluctuation and tends to make belated decisions. This shortcoming stems mainly from the switching mechanism. This paper proposes an improved version of the PSH. The heuristic uses an improved switching mechanism which can be shown to dominate the PSH. The effectiveness of the proposed heuristic is investigated with several well known problems including the paint factory problem. The results are compared with those of the linear decision rule and the linear programming model as well as the PSH.