Effects of a protective foam on scrubbing and gloving

OBJECTIVE: To test the effects of a skin protectant on surgical scrub and glove integrity. DESIGN: Forty-nine healthy adult volunteers were assigned (12 subjects per group) to apply a protective foam (DermaMed; Benchmark Enterprises, Salt Lake City, Utah) in conjunction with surgical scrub in one of the following formulations: 70% isopropyl alcohol, a liquid detergent base containing 4% chlorhexidine gluconate, a liquid detergent base containing 7.5% povidone-iodine, or a nonantimicrobial liquid soap (control). According to a standard protocol, subjects performed a surgical scrub on 3 days (every other day). Foam was applied after surgical scrub on day 1 and before surgical scrub on day 3. No foam was applied on day 2. Subjects were gloved for 2 hours after surgical scrub. SETTING: Laboratory setting. RESULTS: On all test days, there were significant differences in bacterial reduction by products (chlorhexidine gluconate or alcohol > povidone-iodine > control). When controlling for baseline counts and products used, there were no significant differences in colony-forming unit counts on hands with or without foam immediately after scrubbing or at 2 hours after scrub on gloved or ungloved hands, nor were there differences in glove leakage rates when foam was on hands. CONCLUSIONS: Such protectants can be used without detrimental effects to scrub effectiveness or glove integrity.     

Practical steps to smoking cessation for recovering alcoholics

Smoking rates among persons with a history of alcohol abuse are triple that of the general public. Strong evidence indicates that the risk of cancer and cardiovascular disease is higher in recovering alcoholics than in peers who smoke, but do not drink alcohol. Yet these persons often receive less than optimal tobacco counseling out of fear that attempts at smoking cessation will jeopardize their sobriety. Recent research, however, does not support this belief; rather, it suggests that smoking cessation may actually enhance alcohol abstinence. A model for more effective counseling of smokers in recovery is presented, including an algorithm for assessing stages of readiness to change, with activities tailored for each stage. Specific motivational counseling techniques may be useful in encouraging recovering alcoholics to progress to the point that they are ready to change their smoking behavior.     

冲击试验台台面的固有频率及强度分析

台面是冲击试验台的重要部件,它的强度及动态性能直接影响到冲击试验台的设备能力及指标。本文结合模态分析和有限元理论计算,对冲击试验台台面的固有频率及动力强度进行研究及分析,为设计提供依据,并应用于生产实践。     

Phosphate content affects structure and bioactivity of sol-gel silicate bioactive glasses

Bioactive glasses can heal bone defects and bond with bone through formation of hydroxyl carbonate apatite (HCA) surface layer. Sol-gel derived bioactive glasses are thought to have potential for improving bone regeneration rates over melt-derived compositions. The 58S sol-gel composition (60 mol% SiO₂, 36 mol% CaO, and 4 mol% P₂O₅) has appeared in commercial products. Here, hydroxyapatite (HA) was found to form within the 58S glass during sol-gel synthesis after thermal stabilization. The preformed HA may lead to rapid release of calcium orthophosphate, or nanocrystals of HA, on exposure to body fluid, rather than the release of separate the calcium and phosphate species. Increasing the P₂O₅ to CaO ratio in the glass composition reduced preformed HA formation, as observed by XRD and solid-state NMR. Instead, above 12 mol% phosphate, a phosphate glass network (polyphosphate) formed, creating co-networks of phosphate and silica. Nanopore diameter of the glass and rate of HCA layer formation in simulated body fluid (SBF) decreased when the phosphate content increased.     

热处理工艺对N06600合金热轧板组织与性能的影响

研究了热处理工艺对N06600合金热轧板组织与力学性能的影响。结果表明,N06600板材组织主要为奥氏体+沿晶界分布的网状碳化物+晶内碳化物。随着固溶温度的升高,碳化物含量逐渐减少,强度降低,当固溶温度升高至980 ℃,开始发生明显再结晶,同时部分晶粒已充分长大。当固溶温度继续升高至1020 ℃,组织再结晶完成,晶粒平均尺寸达到127 μm,碳化物全部固溶于基体中,强度大幅降低,伸长率显著增加,组织中出现了大量孪晶。N06600合金板材合金化程度低,碳化物含量较低,换向轧制制备的板材横纵向组织与性能差异较小,表现出了较低的各向异性,即使通过650 ℃+950 ℃和950 ℃+650 ℃二次固溶处理,或通过水淬加快冷却速度,组织与性能均保持良好的稳定性。     

一种低功率实现高表面质量的细丝增材制造试验研究

针对在轨制造功率约束与金属增材成形高能量输入的矛盾问题,提出一种激光焦耳复合热源金属细丝增材制造工艺,激光功率仅约50 W,成功制造了宽高比高达40的薄壁结构,使用焦耳热加热丝材可以大大减少激光的功率,从而控制总的热输入,并对成形过程进行有效的热量管理,引入热阻概念进行递变参数优化的方法,有效减小了增材制造特有的台阶效应,成形件表面质量好,表面粗糙度Ra小于5 μm,优于激光选区熔融（Selective laser melting,SLM）工艺,同时,成形件无气孔和裂纹等缺陷,成形件的抗拉强度、致密度以及硬度分布等性能指标,也很接近制造原材料。结果表明,该激光焦耳细丝沉积（Laser Joule fine wire deposition,LJ-FWD）工艺,可以成为高表面质量零件增材制造的一个有吸引力方案,特别适合应用于太空在轨增材制造的快速成形。     

Solid-state fermentation by S. cerevisiae with high resistance to ferulic acid improves the physicochemical properties of wheat bran and quality of bran-rich Chinese steamed bread

Wheat bran has numerous health benefits, but its poor processing and sensory properties limit its application in the staple food industry. Fermentation by S. cerevisiae changes the performance of wheat bran. However, high levels of ferulic acid (FA) inhibit S. cerevisiae. The effects of solid-state fermentation of S. cerevisiae with high resistance to FA on the physicochemical properties of wheat bran and the quality of bran-rich Chinese steamed bread (CSB) were investigated. The results showed that the growth of S. cerevisiae was inhibited by FA in a dose-dependent manner. Short-term adaptation strategies efficiently improved the tolerance of S. cerevisiae to FA stress. Compared with the parental strain (PS), fermentation of the short-term adapted strains (adapted strains) significantly increased the FA, total phenol, and soluble dietary fiber content in wheat bran. Wheat bran fermented by the adapted strains had a higher antioxidant capacity than wheat bran fermented by PS. In addition, compared with the PS, the wheat bran fermented by the adapted strains can decrease the hardness, improve the specific volume, and the quality of CSB. Thus, solid-state fermentation of the adapted strain is a potentially effective method to improve the nutritional and physicochemical properties of wheat bran as a cereal food ingredient.     

高温油藏耐盐聚合物P（AM/MAPS）驱油剂的制备与性能评价

随着聚合物驱广泛应用,部分水解聚丙烯酰胺（HPAM）在高温高盐油藏中存在易水解、增黏能力较差的问 题。为满足目前日益苛刻的储层开采条件,首先利用烯丙基氯与N-甲基牛磺酸钠合成一种耐盐功能单体3-（N-烯丙基-N-甲基氨基）丙烷-1-磺酸钠（MAPS）,进一步与丙烯酰胺（AM）共聚合成了一种新型耐盐聚合物P（AM/ MAPS）;红外光谱法、核磁氢谱法表征证实为目标产物。采用流变仪系统研究了浓度、温度、矿化度及剪切速率 对新型耐盐聚合物溶液黏度的影响规律。结果表明,在温度为85 ℃、矿化度为3×10⁴ mg/L的油藏条件下,质量 浓度为2000 mg/L的P（AM/MAPS）耐盐聚合物溶液的表观黏度达到14.20 mPa·s。在渗透率为527.73×10^-3 μm² 的单管填砂管中,P（AM/MAPS）可在水驱基础上提高采收率13.42百分点;在高低渗透率分别为882.79×10^-3 、 422.53×10^-3 μm² 的双管并联填砂管中,总采收率可提高9.27百分点。该耐盐聚合物P（AM/MAPS）能够高效用于 高温高盐油藏聚合物驱提高采收率技术。     

樟芝发酵产物中安卓奎诺尔的提取纯化

对樟芝发酵产物中的生理活性物质安卓奎诺尔的提取纯化工艺技术进行了研究。结果表明,安卓奎诺尔的最佳的提取条件为:提取溶剂为95%乙醇,料液比1∶25(g/m L),提取温度为35℃,提取时间为85 min。提取液再经过二次柱层析进一步纯化。第一次硅胶柱层析最佳条件为:上样量1∶40(w样品∶w硅胶),径高比1∶30,洗脱流速2.0 BV/h,产物中安卓奎诺尔的纯度为70.2%;第二次硅胶柱层析最佳条件为:洗脱剂v苯∶v丙酮=7∶3,上样量w样品∶w硅胶=1∶30,径高比1∶10,洗脱流速1.0 BV/h,最终产品中安卓奎诺尔的纯度达到91.0%。