Effect of mixing method on resulting thickness of infant formula

Previous research shows that factors such as time, temperature, nutritional make‐up of a liquid, and type of thickening agent can significantly alter the resulting thickness of liquids. This study sought to determine the effect of three distinct mixing methods on the resulting thickness of ready to feed infant formulas mixed to Mildly and Moderately Thick (International Dysphagia Diet Standardization Initiative [IDDSI] Levels 2 and 3) with three different thickening agents. Eight commercially available infant formulas were mixed with three different thickening agents by three different mixing methods. The IDDSI Syringe Flow Test was used to categorize the thickened formulas. Chi square analyses were completed to determine the impact of mixing method on the thickened formulas. The majority (94%) of thickened formula combinations prepared to a target Mildly Thick consistency produced thickened formula that was thinner or thicker than the target. In contrast, the majority (76%) of thickened formula combinations prepared to a target Moderately Thick (IDDSI Level 3) consistency produced thickened formula that was equivalent to the target consistency. A statistically significant relationship was found between mixing methods and resulting IDDSI category for samples mixed to a target of Moderately Thick. The thickening agent and method of mixing must be considered carefully when preparing infant formulas to Mildly and Moderately Thick target IDDSI categories. Based on results of this study, it is recommended that providers utilize a clinical testing method, such as the IDDSI Syringe Flow Test, when attempting to create a Mildly Thick formula consistency.     

Electrospun Hybrid Soy Protein/PVA Fibers

Rheological behavior and spinnability of biodegradable materials based on SPI and PVA were studied for the production of electrospun fibers. pH level, processing temperature, and heating time were adjusted to investigate the effects of denaturing of soy protein on the rheology of SPI/PVA solutions. The results show that zero shear viscosity and degree of shear thinning of the SPI solution can be controlled by adjusting pH level and thermal treatment. The continuous production of uniform SPI/PVA fibers was achieved by electrospinning. The presence and amount of soy protein in the electrospun fibers was determined by EMPA and elemental analysis, confirming that the SPI was well incorporated into the PVA and remained in the electrospun fibers.

     

Crosslinked chitosan doped with Y2(CO3)3 and surface energy and electrorheological properties

Novel electrorheological materials based on crosslinked chitosan doped with Y₂(CO₃)₃ were synthesized with biocompatible chitosan as the substrate of the materials. The electrorheological performance, surface energy, and thermal decomposition behavior of the materials were investigated as functions of the composition change. The results show that doping Y₂(CO₃)₃ can improve effectively the electrorheological performance of crosslinked chitosan with the formation of a metal–polymer complex when the doping degree is suitable. The surface energy plays an important role in influencing the electrorheological properties of the material. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Acetylated and native corn starch blend films produced by blown extrusion

Thermoplastic starch (TPS) materials were developed from mixtures of native and acetylated corn starches with glycerol. To optimize the formulations an experimental design for multicomponent mixtures was used and the assayed formulations were determined by statistical software. Blends and pellets humidity content increased with glycerol concentration. Starch destructuration during the extrusion process was studied by thermal analysis. Films presented homogenous structure, rough surfaces and certain stickiness. They presented different properties, related mainly to the differential characteristics of native and acetylated starches and to hydrophilic character of glycerol. Their mechanical behavior indicated that they are a good option as a food packaging materials since TPS films resulted enough resistant to protect the product and flexible to resist moderate deformations. Besides, the use of acetylated starch in the formulations enhanced film resistance and reduced their WVP, despite of its low modification degree. The storage of the films under controlled conditions increased their stiffness, while their flexibility and WVP were reduced. Plasticizer migration towards the matrix surface was observed in stored films. Films resulted stable till a_w = 0.7 and due to their selective gaseous permeability they are useful to package products susceptible to oxidation or to control vegetable respiration and senescence.     

Involvement of growth factors in thymic involution

The thymus undergoes an age-dependent degenerative process which is mainly characterized by a progressive loss of lymphoid tissue. Thymic involution is particularly important in relation to immunosenescence and its various associated diseases; this fact has prompted many studies aimed at understanding the causes and mechanisms of thymic degeneration which may, ultimately, lead to the possibility of manipulating it. In this sense, one of the aspects which has deserved most attention is the thymic microenvironment, and more precisely, the many growth factors to which the cells present in the organ are exposed. Thus, the levels of several of such factors have been reported to undergo age-dependent changes in the thymus, which may point at an influence on the regression of the organ. In this article we consider which growth factors and growth factor receptors occur in the vertebrate thymus. Then, focusing on those whose influences are better documented, i.e., neurotrophins, cytokines and IGFs, we discuss their potential role in the organ and the possibility of their being involved in thymic involution.     

Quantification and source characterization of volatile organic compounds from exercising and application of chlorine-based cleaning products in a university athletic center

Humans spend approximately 90% of their time indoors, impacting their own air quality through occupancy and activities. Human VOC emissions indoors from exercise are still relatively uncertain, and questions remain about emissions from chlorine-based cleaners. To investigate these and other issues, the ATHLETic center study of Indoor Chemistry (ATHLETIC) campaign was conducted in the weight room of the Dal Ward Athletic Center at the University of Colorado Boulder. Using a Vocus Proton-Transfer-Reaction Time-of-Flight Mass Spectrometer (Vocus PTR-TOF), an Aerodyne Gas Chromatograph (GC), an Iodide-Chemical Ionization Time-of-Flight Mass Spectrometer (I-CIMS), and Picarro cavity ringdown spectrometers, we alternated measurements between the weight room and supply air, allowing for determination of VOC, NH₃, H₂O, and CO₂ emission rates per person (emission factors). Human-derived emission factors were higher than previous studies of measuring indoor air quality in rooms with individuals at rest and correlated with increased CO₂ emission factors. Emission factors from personal care products (PCPs) were consistent with previous studies and typically decreased throughout the day. In addition, N-chloraldimines were observed in the gas phase after the exercise equipment was cleaned with a dichlor solution. The chloraldimines likely originated from reactions of free amino acids with HOCl on gym surfaces.     

Towards standardisation of proof load testing: pilot test on viaduct Zijlweg

Proof load tests of bridges can be very useful for structures with a lack of information, or for structures of which the effect of material degradation is difficult to assess. Contrary to diagnostic load testing, proof load testing is not well-defined in current standards in terms of required load and analysis of measurements. The risk related to the high loads used in proof load testing requires standardisation for these tests. The paper highlights important considerations for proof load testing that may lead to the development of guidelines in the Netherlands, by illustrating a pilot study on the viaduct Zijlweg in the Netherlands. This reinforced concrete bridge rates too low in shear. Topics of interest are the required load that the bridge has to withstand to be approved by the load test and the interpretation of the measurements during the test to avoid permanent damage to the structure. These measurements were compared to the stop criteria from existing codes for buildings, to examine if recommendations for the use with bridges can be formulated. The final result of the test on this case study is that the capacity of the viaduct is proven to be sufficient for shear and bending moment.     

The mountain bike — the dream machine?

This paper examines the development of recreation on mountain bikes, since they were introduced in 1983. It considers some of the social conflicts that have reportedly arisen and then presents the results of a user survey undertaken in 1992. This provides a profile of mountain bike use and users. The aim of the study is to provide landscape managers, planners etc., with basic information about this latest form of countryside recreation so as to encourage more effective provision and management.