Effects of fine grinding of millfeeds on the quality attributes of reconstituted whole-wheat flour and its raw noodle products

Effects of millfeed particle size on the quality of whole-wheat flour (WWF) and raw noodles were investigated. Four ranges of particle size distribution of millfeeds from hard red spring (median diameter: 307, 260, 225, and 178 μm) and hard red winter (median diameter: 319, 274, 235, and 185 μm) were obtained by fine grinding. For both wheat classes, the CIE L* values of WWF decreased and a* and b* values increased with the reduction of millfeed particle sizes. WWF with finer millfeeds exhibited higher PPO activity than that with coarser millfeeds. RVA analysis showed that peak viscosity, trough, and final viscosity of WWF significantly decreased as the particle size of millfeeds reduced, while breakdown and setback values revealed no obvious trend. Reducing the particles of millfeeds not only significantly increased the Farinograph stability time of WWF dough, but also improved the whole-wheat noodle (WWN) brightness (L*) at both 0 and 24 h. Texture profile analysis of cooked noodle indicated that hardness, springiness, cohesiveness and resilience values all significantly increased as the particle sizes of millfeeds were decreased. These results suggest that reduction of millfeed particle sizes before reconstituting WWF could provide beneficial effect on the quality improvement of WWN.     

Stability, antimicrobial activity, and cytotoxicity of poly(amidoamine) dendrimers on titanium substrates

In this article, we present the first report on the antibacterial activity and cytotoxicity of poly(amidoamine) (PAMAM) dendrimers immobilized on three types of titanium-based substrates with and without calcium phosphate coating. We show that the amino-terminated PAMAM dendrimers modified with various percentages (0-60%) of poly(ethylene glycol) (PEG) strongly adsorbed on the titanium-based substrates. The resultant dendrimer films effectively inhibited the colonization of the Gram-negative bacteria Pseudomonas aeruginosa (strain PAO1) and, to a lesser extent, the Gram-positive bacteria Staphylococcus aureus (SA). The antibacterial activity of the films was maintained even after storage of the samples in PBS for up to 30 days. In addition, the dendrimer films had a low cytotoxicity to human bone mesenchymal stem cells (hMSCs) and did not alter the osteoblast gene expression promoted by the calcium phosphate coating.     

Multifunctional carbon-nanotube cellular endoscopes

Glass micropipettes, atomic force microscope tips and nanoneedles can be used to interrogate cells, but these devices either have conical geometries that can damage cells during penetration or are incapable of continuous fluid handling. Here, we report a carbon-nanotube-based endoscope for interrogating cells, transporting fluids and performing optical and electrochemical diagnostics at the single organelle level. The endoscope, which is made by placing a multiwalled carbon nanotube (length, 50-60?μm) at the tip of a glass pipette, can probe the intracellular environment with a spatial resolution of ～100?nm and can also access organelles without disrupting the cell. When the nanotube is filled with magnetic nanoparticles, the endoscope can be remotely manoeuvered to transport nanoparticles and attolitre volumes of fluids to and from precise locations. Because they are mounted on conventional glass micropipettes, the endoscopes readily fit standard instruments, creating a broad range of opportunities for minimally invasive intracellular probing, drug delivery and single-cell surgery.     

Prospective associations between friendship adjustment and social strategies: Friendship as a context for building social skills.

The proposal that friendships provide a context for the development of social skills is widely accepted. Yet little research exists to support this claim. In the present study, children and adolescents (N = 912) were presented with vignettes in which a friend encountered a social stressor and they could help the friend and vignettes in which they encountered a stressor and could seek help from the friend. Social strategies in response to these vignettes were assessed in the fall and spring of the school year. Different indicators of friendship adjustment had unique effects on youths' strategies in response to helping tasks. Whereas having more friends predicted decreases in avoidant or hostile strategies, having high-quality friendships predicted emotionally engaged strategies that involved talking about the problem. Moreover, whereas having more friends predicted increases in relatively disengaged strategies, like distraction and acting like the problem never happened, having high-quality friendships predicted decreases in these strategies. The present study also tested whether youths' strategies in the fall predicted changes in friendship adjustment by the spring. Only strategies which may be seen as major friendship transgressions (i.e., avoiding or blaming the friend when the friend encounters a problem) predicted changes in friendship over time. Collectively, these results provide important new information on the interplay between social competencies and friendship experiences and suggest that friendships may provide a critical venue for the development of important relationship skills. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

An ecological analysis of research examining the experiences of students of color in graduate school.

This article critically reviews methodologies and theoretical orientations of 27 published empirical studies examining the graduate school experiences of students of color using Bronfenbrenner's (1979, 1994) bioecological model. Despite the urgent need for evidence-based approaches to increase the number of scholars of color, the findings in this review indicate an inadequate number of studies explaining how to realize that goal. Furthermore, much of the existing literature examined individual-level characteristics rather than how environmental factors benefit students. Specific recommendations for future ecological research are provided. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Putting off tomorrow to do what you want today: Planning for retirement.

In this article we note that in the coming years, a larger number of people will be experiencing retirement for a longer period of time than ever before and that despite this fact, many will find themselves unprepared for this stage of their lives. We review the literature on retirement preparation, structuring our review around the key questions that need to be addressed when planning for retirement: (a) What will I do? (b) How will I afford it? (c) Where will I live? and (d) Who will I share it with? We make a number of suggestions for research and practice. We conclude that although psychology has begun to play a role in understanding and addressing retirement preparation, there are considerable opportunities for psychologists to engage with this issue in their research and applied work. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

In vivo and in vitro tracking of erosion in biodegradable materials using non-invasive fluorescence imaging

The design of erodible biomaterials relies on the ability to program the in vivo retention time, which necessitates real-time monitoring of erosion. However, in vivo performance cannot always be predicted by traditional determination of in vitro erosion, and standard methods sacrifice samples or animals, preventing sequential measures of the same specimen. We harnessed non-invasive fluorescence imaging to sequentially follow in vivo material-mass loss to model the degradation of materials hydrolytically (PEG:dextran hydrogel) and enzymatically (collagen). Hydrogel erosion rates in vivo and in vitro correlated, enabling the prediction of in vivo erosion of new material formulations from in vitro data. Collagen in vivo erosion was used to infer physiologic in vitro conditions that mimic erosive in vivo environments. This approach enables rapid in vitro screening of materials, and can be extended to simultaneously determine drug release and material erosion from a drug-eluting scaffold, or cell viability and material fate in tissue-engineering formulations.     

Metal nanoparticle plasmon-enhanced light-harvesting in a photosystem I thin film

Silver metal nanoparticle (NP) enhanced fluorescence is investigated in thin films of cyanobacterial Photosystem I trimer complexes (PSI) by correlating confocal laser scanning microscopy, dark-field imaging, and fluorescence lifetime measurements. PSI represents an interesting light-harvesting complex with a 20 nm diameter that is not uniformly contained within the surface-localized plasmon field of the NPs. With weak far-field illumination, 5- to 20-fold fluorescence enhancement is observed for PSI complexes adjacent to NPs, arising from efficient nanoparticle light collection and subsequent localized, surface plasmon excitation of PSI. Enhanced PSI fluorescence is detected most prominently near "rafts" of aggregated NPs that more completely fill the confocal field of view. These results demonstrate opportunities to probe energy transfer within photosynthetic complexes using plasmonic excitation and to design nanostructures for optimizing artificial light-harvesting systems.     

Pulsed laser coating of hydroxyapatite/titanium nanoparticles on Ti-6Al-4V substrates: multiphysics simulation and experiments

Pulsed laser coating (PLC) of bioceramics/metal nanomaterials on metal substrates was investigated in this research. It is found that due to the nature of the nanosized particles and pulse laser beam, PLC processed hydroxyapatite (HAp) coatings possess strong coating/substrate interfacial bonding strength, and minimum thermal decomposition. Feasibility analysis of PLC is conducted using both simulation and experiments. In the multiphysics simulation, laser interacting with metal nanoparticles and heat conduction is simulated by coupling the electromagnetic (EM) module and heat transfer (HT) module. In experiments, HAp and titanium nanoparticle mixture are coated on Ti-6Al-4V substrate using nanosecond pulsed Nd:YAG laser with wavelength of 1064 nm. Resulting temperature is measured by calibrated infrared (IR) camera and compared with simulation results. Experimental results agree well with simulation which serves as a guidance to find appropriate processing parameters. It is found that resulting temperature increases with increasing of pulse energy linearly and decreasing of pulse duration following the power law. It is recommended that shorter pulses to be used in PLC due to its better sinterability. Microstructure and chemical characterizations confirmed that HAp was physically and chemically maintained due to pulse laser caused rapid heating and cooling processes.