Dissemination of an effective inpatient tobacco use cessation program.

The present study aimed to determine whether tobacco use cessation rates observed in controlled trials of a hospital-based tobacco use cessation program could be replicated when the program was disseminated to a wide range of hospitals in a two-stage process including implementation and institutionalization phases. Using a nonrandomized, observational design, we recruited six hospitals to participate in the study. The research team helped implement the program during the first year of participation (implementation) and then withdrew from active involvement during the second year (institutionalization). The mean 6-month self-reported cessation rates were 26.3% (range = 17.6%-52.8%) for the implementation phase and 22.7% (range = 12.9%-48.2%) for the institutionalization phase. Hospitals with paid professionals providing the program had the best outcomes. Inpatient tobacco use cessation programs are feasible to implement and should target a 6-month self-reported cessation rate of at least 25%.     

Cocoa polyphenols accelerate vitamin B12 degradation in heated chocolate milk

The rate of vitamin B₁₂ loss was 3X greater in heated, chocolate‐flavoured milk than in unflavoured milk. Studies of B₁₂ stability in the presence of cocoa powder components were performed to identify the reactive agents. Cocoa polyphenols with a strong capacity both for reduction and for peroxide generation accelerated B₁₂ destruction as much as 20‐fold vs. polyphenols without both capacities. Polyphenols with both capacities include the cocoa polyphenol (+)‐catechin and oligomers thereof, but also the structurally related polyphenols gallic acid, caffeic acid and (?)‐epigallocatechin gallate. The demonstrated physical affinity of cocoa powder for B₁₂ was a significant factor in the destructive process. B₁₂ may exhibit decreased stability in heated, neutral pH, polyphenol‐fortified foods.     

分数Vasicek利率下创新重置期权定价

假定股票价格过程服从分数跳-扩散过程,利率满足分数Vasicek利率模型,利用分数跳-扩散过程理论以及保险精算方法,讨论了创新重置期权的定价问题,获得了创新重置看涨期权定价公式,推广了关于创新重置期权定价的相关结果.     

用于估计多隧道开挖地面沉降的解析解

对于均质弹性地基中单隧道和多隧道开挖施工,本文给出了用于计算二维和三维地面沉降的近似的显式解析解.该解析解是对点荷载下Mindlin位移解进行积分并利用泰勒级数展开而得.利用该解析解,可以计算多个任意相对位置的隧道掘进引起的地面沉降.对于隧道开挖面不同支护程度的情况,可以采用一个原位应力释放度(系数)来模拟.通过一个单隧道开挖的弹性有限元计算对比,对简化的解析解进行了检验,两者计算结果的差距在9%以内.简化解析解的有效性,通过两种情况(两条相互平行隧道和两条相互垂直隧道)的计算得到验证.     

非饱和土试验中的先进吸力控制技术

介绍和评价了海外常用的3种吸力控制技术:轴平移、渗透和湿度控制。论述了每种技术的工作原理、发展过程、应用情况和优缺点。对文献中采用轴平移和渗透技术得到的试验结果进行了比较和讨论。另外,在直剪试验的剪切阶段前施加不同的吸力平衡历时,用以展示吸力平衡历时对随后的剪切过程中的各种剪切性状(抗剪强度和体变)的影响。     

The chemistry of ethyl silicate binders in refractory technology

The chemistry of the processes involved when an alkyl silicate such as ethyl silicate acts as a binder in refractory technology is described. The gel forming process involving catalysed hydrolysis and condensation of ethyl silicate and tetra-alkyl silicates has been studied using amine catalysts. Thermal studies of gels obtained from technical ethyl silicate and of gels obtained from technical ethyl silicate incorporated in refractory materials, together with infrared spectroscopy studies of gels obtained from technical ethyl silicate, suggest the nature of the degradation products, and the weight-loss patterns observed support the proposed mechanisms.     

Graft copolymerization onto rubber. VII. Graft copolymerization of methyl methacrylate onto rubber using potassium peroxydisulfate catalyzed by silver ion

The graft copolymerization of methyl methacrylate onto natural rubber (NR) was carried out varying the concentration of monomer, initiator, thiourea, and silver nitrate over a wide range. The grafting reaction was temperature-dependent. From the Arrhenius plot, the overall energy of activation was computed. A suitable reaction scheme and rate expression for the rate of polymerization was suggested.     

Heptaldehyde and undecylenic acid from castor oil

Castor Oil was pyrolyzed in a vertical stainless steel tubular reactor packed with 12.5-mm diameter mild steel balls in presence of 0.5% benzoyl peroxide. The operating parameters were optimized to obtain high yields of heptaldehyde and undecylenic acid. Heating at 550 C under reduced pressure of 45 mm (Hg) yielded 24.8% heptaldehyde and 36.0% undecylenic acid.