Synthesis and characterization of antiseptic-based poly(anhydride-esters)

Summary Poly(anhydride-esters) were prepared from catechol, fenticlor and hexachlorophene. The molecular weights (M_w) of the polymers were typically >10,000 Da with glass transition temperatures (T_g) ranging from 23 to 84 °C. The thermal characteristics of the polymers paralleled the melting temperatures of the chemically incorporated antiseptic molecules. The in vitro release of the chemically incorporated antiseptic molecules were monitored over a 12 week period. For comparison, the in vitro release of physically admixed antiseptic molecules were also observed. After 12 weeks, the polymers were not completely degraded with drug release ranging from less than 1 to 55%. Sessile-drop contact angles indicated that the polymers were relatively hydrophobic, contributing to the slow polymer degradation rates.     

Soy protein supplementation does not cause lymphocytopenia in postmenopausal women

Background  

The health benefits of soy isoflavones have been widely investigated; however, there are some concerns as to whether soy isoflavones, similar to ipriflavone, a synthetic isoflavone, cause lymphocytopenia in postmenopausal women. Hence, the purpose of this study was to investigate the extent to which 12-month supplementation of 25 g soy protein containing 60 mg isoflavones alters lymphocyte counts or other hematological parameters in postmenopausal women who were not on hormone replacement therapy.     

Improved magnetic particle tracking technique in dense gas fluidized beds

Noninvasive monitoring of multiphase flow is rapidly gaining increased interest. More specifically noninvasive particle tracking techniques have received a lot of attention in recent years to study dense granular flow. However, these techniques are usually quite expensive and require strict safety measures. An improved magnetic particle tracking (MPT) technique for dense granular flow will be presented in this article. The improvements of the analysis technique for MPT will be demonstrated and rigorously tested with a three‐dimensional system and two‐dimensional sensor system. The strengths and limitations of the MPT technique will also be reported. Finally, the results of the MPT are compared with data obtained from a combined particle image velocimetry and digital image analysis technique. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3133–3142, 2014     

In Vacuo Tribological Behavior of Polytetrafluoroethylene (PTFE) and Alumina Nanocomposites: The Importance of Water for Ultralow Wear

Polytetrafluoroethylene (PTFE) is widely regarded as an excellent candidate for solid lubrication in vacuum. However, it is often precluded from many practical applications due to its intrinsically high wear rate. Over the past decade, it has been discovered that small loading fractions of alumina nanofillers can increase the wear resistance of PTFE by three to four orders of magnitude. This dramatic increase in wear resistance has in turn prompted numerous tribological studies to examine the robustness of this performance. In this study, the wear and friction behavior of unfilled PTFE and PTFE and alumina nanocomposites were evaluated under a broad range of vacuum environments from 760 to 4 × 10^?6 Torr. The nanocomposites of PTFE/alumina showed a dramatic increase in wear of over two orders of magnitude at the highest vacuum conditions. There appears to be an optimal vacuum environment around 1–10 Torr, in which these samples achieved the lowest wear rates of approximately 2.5 × 10^?7 mm³/(Nm).     

Holey carbon micro-arrays for transmission electron microscopy: a microcontact printing approach

We have used a microcontact printing approach to produce high quality and inexpensive holey carbon micro-arrays. Fabrication involves: (1) micromolding a poly(dimethylsiloxane) (PDMS) elastomer stamp from a microfabricated master that contains the desired array pattern; (2) using the PDMS stamp for microcontact printing a thin sacrificial plastic film that contains an array of holes; (3) floating the plastic film onto TEM grids; (4) evaporating carbon onto the plastic film and (5) removing the sacrificial plastic film. The final holey carbon micro-arrays are ready for use as support films in TEM applications with the fidelity of the original microfabricated pattern. This approach is cost effective as both the master and the stamps have long-term reusability. Arbitrary array patterns can be made with microfabricated masters made through a single-step photolithographic process.     

Measuring the effectiveness of a mass customization and personalization strategy: a market- and organizational-capability-based index

The research of Kumar (Int J Flex Manuf Syst 16(4):287–312, 2004) is expanded to develop a methodology that measures the effectiveness of a mass customization and personalization strategy using a mass customization and personalization effectiveness index. This index extends Kumar (2004) in three significant ways: (1) it encompasses both service and manufacturing companies, (2) the assessment of product customization considers that customers assign different weights to different product features, and (3) the index captures the impact of both market perception and system capabilities. Three different measures are proposed. Which is appropriate should be a function of a particular company’s parameters. The circumstances under which each measure is best is a subject for future research. The validation and reliability of this index and these measures are also issues that should be addressed by future research.

Preventing discoloration of squalene-soiled cotton fabrics with antioxidants

Removal of discoloration caused by aged oily soils is difficult because oily soils undergo autoxidation, which results in polymerization and formation of chromophores. Use of antioxidants and a reducing agent was investigated for their impact on appearance retention and soil removal. The effect of a reducing agent, sodium dithionite, on the removal of aged squalene from cotton fabrics was studied as a pretreatment to laundering, which enhanced the removal of squalene as well as whiteness restoration. Increases in treatment concentration and time increased color removal. However, no significant increase was found in oil removal, suggesting that the role of the reducing agent is mainly a reductive bleaching action. Thus, the color will probably reverse by oxidation over time making this approach a not-so-promising laundry treatment. As a method of preventing discoloration of oily soiled textile materials, antioxidants Irganox^® 1010, t-butylhydroxyanisole and α-tocopherol were examined; they were found to be effective antioxidants for this purpose by preventing the discoloration of squalene upon aging. With Irganox^® 1010, this prevention occurred without decreasing the detergency of the oil. Most importantly, these antioxidants either did not stain the substrate or showed very low levels of staining upon usage. The biggest barrier to applying antioxidants on textiles is their hydrophobic nature. A search for water-soluble antioxidants with nonstaining and good oxidation inhibiting properties is necessary.     

Aging of oily soils on textiles. Chemical changes upon oxidation and interaction with textile fibers

Aging of unsaturated oily soils on textile materials produces yellow compounds that are difficult to remove by washing. To investigate changes that occur in oily soils when aged, the aging of squalene and artificial sebum were studied. Proton nuclear magnetic resonance, infrated spectroscopy, gas chromatography, and gel permeation chromatography studies showed that oily soils were oxidized upon aging, forming low molecular weight products that also polymerized to higher molecular weight compounds with prolonged aging. The oxidation products contained hydroxyl, carbonyl, or ester groups. Oxidation compounds with yellow chromophores appeared to be mostly those of the 1000–2500 molecular weight fraction; though in earlier, stages of aging, lower molecular weight fractions also contained chromophores. By using glucose as a model compound of cellulose, it was found that yellow oxidation products of aged squalene were covalently bound to the substrate. Because the aging of oily soils is a free-radical oxidation process, oxidation products having chromophores are thought to attach to the cotton substrate through radical coupling. Oily soils also showed possibilities of chemical bonding with nylon but not with polyester.     

Analysis of thermal properties of polymeric biomaterials. I. Ultrahigh-molecular-weight polyethylene

The effects of sample size and heating and cooling rates on thermal transitions of ultrahigh-molecular-weight polyethylene (UHMWPE) were investigated. The thermal parameters were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). While heating rates and sample size had strong effects on thermal properties, the influences of cooling rates were minor. For DSC, broad melting transitions were obtained at faster heating and/or slower cooling rates and larger sample sizes. Higher melting temperatures were obtained when heating rates and sample size were increased. Slower cooling rates also produced higher melting and crystallization temperatures. Faster cooling rates yielded lower heats of fusion during melting and also lower heats of crystallization. The dependence of peak melting and crystallization temperatures on the heating and cooling rates are illustrated by two empirical formulas. For TGA, it is found that faster heating rates and larger sample sizes produced higher decomposition temperatures. This detailed analysis may explain the large variations in the reported data on thermal properties and crystallinity of UHMWPE and provide solutions to the current clinical problems associated with polymeric biomaterials. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1353–1361, 1998     

Smart Playing Cards: A Ubiquitous Computing Game

We present the ‘Smart Playing Cards’ application, a ubiquitous computing game that augments a classical card game with information technological functionality by attaching RFID tags to the cards. We also mention requirements that such an application makes on a supporting software infrastructure for ubiquitous computing. Correspondence to: Nr K. R?mer or Ms S. Domnitcheva, Department of Computer Science, ETH Zürich, 8092 Zürich, Switzerland. Email: roemer@inf.ethz.ch, or domnitch@ inf.ethz.ch