This research reports age and gender differences in cardiac reactivity and subjective responses to the induction of autobiographical memories related to anger, fear, sadness, and happiness. Heart rate (HR) and subjective state were assessed at baseline and after the induction of each emotion in 113 individuals (61 men, 52 women; 66% European American, 34% African American) ranging in age from 15 to 88 years (M = 50.0; SD = 20.2). Cardiac reactivity was lower in older individuals; however, for anger and fear, these age effects were significantly more pronounced for the women than the men. There were no gender differences in subjective responses, however, suggesting that the lower cardiac reactivity found among older people is dependent on gender and the specific emotion assessed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
Summary: The influence of number‐average molecular weight ranging from 1.4 · 104 to 1.2 · 106 g/mol on the thermal behaviour of polytetrafluoroethylene (PTFE) has been studied. Samples have been prepared by radiation‐induced degradation of commercial PTFE. The molecular weight has been calculated using end‐group concentration determined by infrared (IR) spectroscopy and 19F solid‐state nuclear magnetic resonance (NMR) spectroscopy. Melting and crystallisation heats were investigated by differential scanning calorimetry (DSC). The results have been discussed with respect to quantitative relationships between number‐average molecular weight and heat of crystallisation of PTFE described in the literature. The molecular weight calculated from Suwa's equation, which is often used in the literature, has been found to be too low.
Concentration of end‐groups and the molecular weight of PTFE versus the irradiation dose. 相似文献
Journal of Intelligent Manufacturing - Remanufacturing includes disassembly and reassembly of used products to save natural resources and reduce emissions. While assembly is widely understood in... 相似文献
Agroindustrial by-products are an abundant source of biocompounds that contain valuable nutrients, which are not exploited. In this work, lignocellulosic wastes (LW) were used in submerged fermentation (SmF) and solid-state fermentation (SSF) by Aspergillus niger NRRL3 to obtain valuable enzymes required in industries. SmF using soya bean hulls (SH), wheat bran (WB) and a by-product of wheat flour (F) produced the highest activities of endo-1,4-β-xylanase (Xyl) and endo-1,4-β-D-glucanase (EG) being at least 3 times lower than those obtained by SSF. The highest ratio of Xyl to EG was obtained in SmF with F. Xyl obtained by SmF with WB was the most thermally resistant. The enzymatic extract obtained in SmF using SH presented a high power of saccharification. The production of enzymes for further application such as bioethanol generation process revalue these LW and can help offset growing environmental problems. 相似文献
Investigations on Potato Pulp as a Dietary Fiber Source. Composition of Potato Pulp After Influence of Pectinases and Cellulases and Enzymatic Degradation of Starch. The composition of alcohol insoluble substances (AIS) of potato pulp have been investigated after succesive degradation with different pectolytic and cellulolytic enzymes followed by starch degrading enzymes. The pretreatment with pectinase/cellulase combinations has a significant influence on the amount and the properties of the residues after starch degradation. Furthermore the most important changes in the composition were found in the receiving residues after action of amylolytic enzymes. A correlation exists between the content of residual starch in the residues and the action of the cell wall degrading enzymes. The amount of residual starch correlates negatively with the intensity of cell wall degradation. The enzymatic susceptibility of starch depends on the damage of cell wall of potato pulp, especially on the degree of degradation of the cellulose. The water binding capacity decreases intensively after action of pectinase/cellulase combinations. The treatment with amylolytic enzymes causes only a negligible variation of the water binding capacity. 相似文献
Solid sodium alginate was dissolved into chicken stock in order to give a final alginate concentration of 0.9 percent (w/v). Calcium ions present in chicken stock were enough to induce ionic gelation. After drying, Fourier transform infrared spectroscopy, thickness and mechanical properties of films obtained were determined. Calcium alginate‐chicken stock films were heated at 130 °C for different times between 0 and 15 min. Mechanical and optical studies, differential scanning calorimetry, visual aspect and scanning electron microscopy were carried out to describe physicochemical properties of heat treated films. Heating developed a maroon ochre color and increased the brittleness (crispness) of the films related to the intensity of the treatment. Differential scanning thermometry and study on appearance of the films suggested that Maillard reactions may be responsible for the observed changes. Maillard reactions mainly occurred between reducing sugar monomers and free amino groups of gelatin peptides present in the chicken stock, and between alginate and gelatin peptides to a lesser extent. In addition, the plasticizing effect of fat added with chicken stock was also studied. These studies suggest a potential use of heat treated chicken stock films as a substitute of roasted chicken skin. 相似文献
Through the natural evolutionary process, organisms have been improving amazing mineralized materials for a series of functions using a relatively few constituent elements. Biomineralization has been widely studied in the last years. It is important to understand how minerals are produced by organisms and also their structure and the corresponding relationship with the properties and function. Moreover, one can look at minerals as a tool that could be used to develop high performance materials, through design inspiration and to find novel processing routes functioning at mild conditions of temperature, pressure and solvent type. As important as the molecular constituents are structural factors, which include the existence of different levels of organization and controlled orientation. Moreover, the way how the hierarchical levels are linked and interfacial features plays also a major role in the final behavior of the biogenic composite. The main aim of this work is to review the latest contributions that have been reported on composite materials produced in nature, and to relate their structures at different length scales to their main functions and properties. There is also an interest in developing new biomimetic procedures that could induce the production of calcium phosphate coatings, similar to bone apatite in substrates for biomedical applications, namely in orthopedic implants and scaffolds for tissue engineering and regenerative medicine; this topic will be also addressed. Finally, we also review the latest proposed approaches to develop novel synthetic materials and coatings inspired from natural-based nanocomposites. 相似文献