Recent studies of self-condensation and co-condensation of melamine-formaldehyde resins; cure at low temperatures

Self-condensation: recent research on the chemical pathways by which alcoholated melamine-formaldehyde (MF) resins react with themselves and on the product structures is summarized. Model compound studies suggest that bridges are less stable than widely thought unless they are in hexahydro-1,3,5-triazine ring structures. In acyclic structures they are probably less stable than bridges. Co-condensation: studies of how the composition of MF resins influences the rates of reaction with poly(ol) co-reactant show that MF resins that contain very low levels of and/or functionality are quite reactive. Reactivities of a variety of poly(ester) and acrylic coreactants were studied. By combining reactive MF resins with reactive co-reactants one can formulate high solids enamels that cure by co-condensation in 30 min at 50 to 65 °C with 0.5 parts per hundred (phr) of p-toluenesulfonic acid (p-TSA) catalyst. Cure at 25 °C appears feasible with higher catalyst levels.     

Application of a second-moment turbulence closure to heat and mass transport in thin shear flows—I. Two-dimensional transport

The paper presents developments of a second-moment approximation to turbulent convection in which the turbulent heat fluxes themselves form the subject of a set of transport equations. Closure at this level avoids the need to prescribe the turbulent Prandtl number which is the principal empirical uncertainty in simpler treatments. Applications are reported of heat transfer in a variety of free shear flows and boundary layers. While fairly successful overall agreement is achieved, the model does not fully account for the observed variations of turbulent Prandtl number from one free shear flow to another and equally gives rather inaccurate predictions downstream of a short heated patch in a wall.     

Downregulation of miR-99b-5p and Upregulation of Nuclear mTOR Cooperatively Promotes the Tumor Aggressiveness and Drug Resistance in African American Prostate Cancer

Mammalian target of rapamycin (mTOR) regulates various fundamental cellular events including cell proliferation, protein synthesis, metabolism, apoptosis, and autophagy. Tumor suppressive miR-99b-5p has been implicated in regulating PI3K/AKT/mTOR signaling in a variety of types of cancer. Our previous study suggested the reciprocal miR-99b-5p/MTOR (downregulated/upregulated) pairing as a key microRNA-mRNA regulatory component involved in the prostate cancer (PCa) disparities. In this study, we further validated the expression profiles of mTOR and miR-99b-5p in the PCa, colon, breast, and lung cancer specimens and cell lines. The immunohistochemistry (IHC), immunofluorescence, Western blot, and RT-qPCR assays have confirmed that mTOR is upregulated while miR-99b-5p is downregulated in different patient cohorts and a panel of cancer cell lines. Intriguingly, elevated nuclear mTOR expression was observed in African American PCa and other advanced cancers. Transfection of the miR-99b-5p mimic resulted in a significant reduction in nuclear mTOR and androgen receptor (AR), while a slight/moderate to no decrease in cytoplasmic mTOR and AR in PCa and other cancer cells, suggesting that miR-99b-5p inhibits mTOR and AR expression and their nuclear translocation. Moreover, overexpression of miR-99b-5p targets/inhibits AR-mTOR axis, subsequently initiating cell apoptosis and sensitizing docetaxel-induced cytotoxicity in various cancers. In conclusion, our data suggest that reciprocal miR-99b-5p/nuclear mTOR pairing may be a more precise diagnostic/prognostic biomarker for aggressive PCa, than miR-99b-5p/MTOR pairing or mTOR alone. Targeting the AR-mTOR axis using miR-99b-5p has also been suggested as a novel therapeutic strategy to induce apoptosis and overcome chemoresistance in aggressive PCa.     

Improving functional value of meat products

In recent years, much attention has been paid to develop meat and meat products with physiological functions to promote health conditions and prevent the risk of diseases. This review focuses on strategies to improve the functional value of meat and meat products. Value improvement can be realized by adding functional compounds including conjugated linoneleic acid, vitamin E, n3 fatty acids and selenium in animal diets to improve animal production, carcass composition and fresh meat quality. In addition, functional ingredients such as vegetable proteins, dietary fibers, herbs and spices, and lactic acid bacteria can be directly incorporated into meat products during processing to improve their functional value for consumers. Functional compounds, especially peptides, can also be generated from meat and meat products during processing such as fermentation, curing and aging, and enzymatic hydrolysis. This review further discusses the current status, consumer acceptance, and market for functional foods from the global viewpoints. Future prospects for functional meat and meat products are also discussed.     

Enhanced reactivity of melamine–formaldehyde resins by fractionation. Crosslinking at ambient temperature

A commercial hexakis(methoxymethyl)melamine (HMMM) resin was fractionated (1) by crystallization of the hexane–soluble fraction from hexane and (2) by partitioning the hexane–soluble and hexane–Insoluble fractions between alumina and various solvents. Crystallization afforded hexakis(methoxymethyl)melamine (1) of 90 to 95% purity. Partitioning afforded 12 fractions with altered proportions of polar and nonpolar species; the least polar fraction was spectroscopically and chromatographically similar to the crystallized material. Relative reactivities of certain fractions were estimated by ¹H NMR studies of the rates of reaction with neopentyl alcohol in the presence of catalytic amounts of p-toluenesulfonic acid (p-TSA). It was found that the reactivity of fractions, rich in less-polar species, was substantially greater than that of the commercial HMMM resin, whereas reactivity of fractions, rich in polar species, was less. Reactivity was especially enhanced by removal of all active hydrogen species, notably those containing NH groups. A practical consequence of this result was that fully formylated and alkylated melamine resins could crosslink with polyols at substantially lower temperatures than the commercial HMMM resin, which contained NH groups. Therefore, room-temperature crosslinking was feasible.     

Egg yolk phosvitin and functional phosphopeptides--review

Phosphopeptides are among the most interesting biomolecules with characteristic molecular structure and functions. They usually contain clusters of phosphoserines, which can effectively bind calcium and iron, and inhibit formation of insoluble calcium phosphates or iron complexes. Therefore, phosphopeptides can increase calcium or iron bioavailability and prevent lipid oxidation in foods. Milk protein casein has been currently used by industry to produce phosphopeptides. Egg yolk phosvitin is considered as the most phosphorylated protein found in the nature. Phosvitin from egg yolk can be much better source for producing phosphopeptides with varying sizes and functions than casein because it contains much greater number of phosphates in the molecule than casein. However, still phosvitin has not been subjected to considerable attention with regard to bioactive peptides production.     

Lesion site patterns in severe, nonverbal aphasia to predict outcome with a computer-assisted treatment program

OBJECTIVE: To test whether lesion site patterns in patients with chronic, severe aphasia who have no meaningful spontaneous speech are predictive of outcome following treatment with a nonverbal, icon-based computer-assisted visual communication (C-ViC) program. DESIGN: Retrospective study in which computed tomographic scans performed 3 months after onset of stroke and aphasia test scores obtained before C-ViC therapy were reviewed for patients after receiving C-ViC treatment. SETTING: A neurology department and speech pathology service of a Department of Veterans Affairs medical center and a university aphasia research center. PATIENTS: Seventeen patients with stroke and severe aphasia who began treatment with C-ViC from 3 months to 10 years after onset of stroke. MAIN OUTCOME MEASURE: Level of ability to use C-ViC on a personal computer to communicate. RESULTS: All patients with bilateral lesions failed to learn C-ViC. For patients with unilateral left hemisphere lesion sites, statistical analyses accurately discriminated between those who could initiate communication with C-ViC from those who were only able to answer directed questions. The critical lesion areas involved temporal lobe structures (Wernicke cortical area and the subcortical temporal isthmus), supraventricular frontal lobe structures (supplementary motor area or cingulate gyrus 24), and the subcortical medial subcallosal fasciculus, deep to the Broca area. Specific lesion sites were also identified for appropriate candidacy for C-ViC. CONCLUSIONS: Lesion site patterns on computed tomographic scans are helpful to define candidacy for C-ViC training, and to predict outcome level. A practical method is presented for clinical application of these lesion site results in combination with aphasia test scores.     

Estimating the quality of functional programs: an empirical investigation

This paper describes an investigation into estimating the quality of functional programs. The work reported here is part of a larger, ongoing study into a quantitative analysis of the effect of utilizing different programming paradigms on code quality. Before undertaking such a comparative analysis it was necessary to establish a baseline of quality indicators which could then be used as metrics for the remainder of the project. Thus the aim of the research presented here was to evaluate a set of suggested indicators corresponding to internal attributes by investigating the correlation between the suggested indicators and the desired external quality-type attributes of the code. A method for the evaluation of the suggested metrics is discussed and the results of performing such an evaluation for functional programs are presented.     

MicroRNA-mRNA Regulatory Network Mediates Activation of mTOR and VEGF Signaling in African American Prostate Cancer

African American (AA) men exhibit 1.6-fold higher prostate cancer (PCa) incidence and 2.4-fold higher mortality rates compared to European American (EA) men. In addition to socioeconomic factors, emerging evidence suggests that intrinsic biological differences may explain part of PCa disparities. In this study, we applied microRNA (miRNA)-driven bioinformatics to evaluate whether differential miRNA-mRNA regulatory networks play a role in promoting the AA PCa disparities. 10 differentially expressed miRNAs were imported to mirPath V.3 algorithm, leading to identification of 58 signaling pathways differentially regulated in AA PCa versus EA PCa. Among these pathways, we particularly focused on mTOR and VEGF signaling, where we identified 5 reciprocal miRNA-mRNA pairings: miR-34a-5p/HIF1A, miR-34a-5p/PIK3CB, miR-34a-5p/IGFBP2, miR-99b-5p/MTOR and miR-96-5p/MAPKAPK2 in AA PCa versus EA PCa. RT-qPCR validation confirmed that miR-34a-5p, miR-99b-5p and MAPKAPK2 were downregulated, while miR-96-5p, IGFBP2, HIF1A, PIK3CB and MTOR were upregulated in AA PCa versus EA PCa cells. Transfection of miRNA mimics/antagomir followed by RT-qPCR and Western blot analysis further verified that IGFBP2, HIF1A and PIK3CB are negatively regulated by miR-34a-5p, whereas MTOR and MAPKAPK2 are negatively regulated by miR-99b-5p and miR-96-5p, respectively, at mRNA and protein levels. Targeting reciprocal pairings by miR-34a-5p mimic, miR-99b-5p mimic or miR-96-5p antagomir downregulates HIF1α, PI3Kβ, mTOR, IGFBP2 but upregulates MAPKAPK2, subsequently reducing cell proliferation and sensitizing docetaxel-induced cytotoxicity in PCa cells. These results suggest that miRNA-mRNA regulatory network plays a critical role in AA PCa disparities, and targeting these core miRNA-mRNA pairings may reduce PCa aggressiveness and overcome the chemoresistance in AA patients.