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41.
De La Torre Jessica Elizabeth Fatma Gassara Anne Patricia Kouassi Khaled Belkacemi 《Critical reviews in food science and nutrition》2017,57(6):1078-1088
Spices are parts of plants that due to their properties are used as colorants, preservatives, or medicine. The uses of spices have been known since long time, and the interest in the potential of spices is remarkable due to the chemical compounds contained in spices, such as phenylpropanoids, terpenes, flavonoids, and anthocyanins. Spices, such as cumin (cuminaldehyde), clove (eugenol), and cinnamon (cinnamaldehyde) among others, are known and studied for their antimicrobial and antioxidant properties due to their main chemical compounds. These spices have the potential to be used as preservatives in many foods namely in processed meat to replace chemical preservatives. Main chemical compounds in spices also confer other properties providing a variety of applications to spices, such as insecticidal, medicines, colorants, and natural flavoring. Spices provide beneficial effects, such as antioxidant activity levels that are comparable to regular chemical antioxidants used so they can be used as a natural alternative to synthetic preservatives. In this review, the main characteristics of spices will be described as well as their chemical properties, different applications of these spices, and the advantages and disadvantages of their use. 相似文献
42.
Linkenauger Sally A.; Witt Jessica K.; Stefanucci Jeanine K.; Bakdash Jonathan Z.; Proffitt Dennis R. 《Canadian Metallurgical Quarterly》2009,35(6):1649
Previous research has suggested that perceived distances are scaled by the action capabilities of the body. The present studies showed that when “reachability” is constrained due to a difficult grasp required to pick up an object, perceived distance to the object increases. Participants estimated the distances to tools with handle orientations that made them either easy or difficult to grasp with their dominant and nondominant hands. Right-handed participants perceived tools that were more difficult to grasp to be farther away than tools that were easier to grasp. However, perceived distance did not differ in left-handed participants. These studies suggest that, when reaching toward a target, the distance to that target is scaled in terms of how far one can effectively reach, given the type of reaching posture that is executed. Furthermore, this effect is modulated by handedness. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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The Density of States and the Transport Effective Mass in a Highly Oriented Semiconducting Polymer: Electronic Delocalization in 1D 下载免费PDF全文
45.
Jessica Kaminsky 《Construction Management & Economics》2013,31(11-12):942-956
Infrastructure that goes unused – for example, after constructing the first water, electricity, sewers or road infrastructure in an infrastructure-poor community – is a common issue in new infrastructure development in the global south. In this case, while infrastructure has diffused, it has not become institutionalized. To better understand this problem, photo-elicitation methods are used to explore cultural-cognitive frames used by research respondents as they create and explain photograph symbols that represent change in their built environment. For example, respondents advocate for infrastructure they have reason to believe outsiders will provide as they evaluate the infrastructure against local utility in an early phase of institutionalization. Respondents also frame the research undertaking as an opportunity to actively diffuse infrastructure practices they have recently adopted themselves. By making these and other frames explicit, the photo-elicitation method reveals the elusive cultural-cognitive pillar of institutionalization and also provides insight into sources of self-reporting bias. The method also has particular advantages for research dealing with disadvantaged respondents, reduces issues of free recall bias and increases the length and depth of research interviews. Given the relative novelty of this method in construction research, its theory, advantages and limitations are discussed in some depth. 相似文献
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47.
Kelvin Y. Xie Muhammet F. Toksoy Kanak Kuwelkar Binwei Zhang Jessica A. Krogstad Richard A. Haber Kevin J. Hemker 《Journal of the American Ceramic Society》2014,97(11):3710-3718
Uniform densification of relatively thick (~7 mm) consolidated boron carbide plates at relatively low temperatures (e.g. 1800°C) and low facture toughness are two of the primary challenges for further development of boron carbide applications. This work reports that these two challenges can be overcome simultaneously by adding 5 wt% alumina as a sintering aid. Nearly fully dense (97%), fine grained boron carbide (B4C) samples were produced using spark plasma sintering at 1700°C and above in the B4C‐5 wt% Al2O3 system. The alumina and boron carbide matrix reacted to form an Al5O6BO3 (a mullite‐like phase) during sintering. The Al5O6BO3 phase facilitated uniform densification via liquid phase sintering. This secondary phase is dispersed throughout the intergranular pores, providing obstacles for crack propagation and resulting in tougher boron carbide ceramics. 相似文献
48.
Jessica D. Leuchter Adam T. Green Julian Gilyard Cecilia G. Rambarat Samuel S. Cho 《Israel journal of chemistry》2014,54(8-9):1152-1164
Although the main features of the protein folding problem are coming into clearer focus, the microscopic viewpoint of nucleic acid folding mechanisms is only just beginning to be addressed. Experiments, theory, and simulations are pointing to complex thermodynamic and kinetic mechanisms. As is the case for proteins, molecular dynamics (MD) simulations continue to be indispensable tools for providing a molecular basis for nucleic acid folding mechanisms. In this review, we provide an overview of biomolecular folding mechanisms focusing on nucleic acids. We outline the important interactions that are likely to be the main determinants of nucleic acid folding energy landscapes. We discuss recent MD simulation studies of empirical force field and Go-type MD simulations of RNA and DNA folding mechanisms to outline recent successes and the theoretical and computational challenges that lie ahead. 相似文献
49.
Flore Mas Jessica Vereijssen David M. Suckling 《Journal of chemical ecology》2014,40(11-12):1197-1202
Candidatus Liberibacter solanacearum (CLso) is an unculturable bacterium vectored by the tomato potato psyllid (TPP) Bactericera cockerelli and has been associated with Zebra chip disease in potato and with other economically relevant symptoms observed in solanaceous crops. By altering their host and vector’s biological system, pathogens are able to induce changes that benefit them by increasing their transmission rate. Understanding these changes can enable better targeting of mechanisms to control pathogen outbreaks. Here, we explored how the CLso infectious status affects the volatile organic compounds (VOCs) of the tomato plant, and whether the CLso infectious status of TPP influences host plant settlement. These chemical and behavioral changes can ultimately affect the rate of encounter between the host and the vector. Results from headspace volatile collection of tomato plants showed that CLso infected tomato plants emitted a qualitatively and quantitatively different blend of VOCs compared to sham-infected plants. By a factorial experiment, we showed that CLso negative (CLso-) TPP preferred to settle 70 % more often on infected tomato plants, while CLso positive (CLso+) TPP were found 68 % more often on sham-infected tomato plants. These results provide new evidence in favor of both host and vector manipulation by CLso. 相似文献
50.
Murphy James G.; MacKillop James; Skidmore Jessica R.; Pederson Ashley A. 《Canadian Metallurgical Quarterly》2009,17(6):396
Recent clinical research suggests that several self-report behavioral economic measures of relative reinforcing efficacy (RRE) may show utility as indices of substance abuse problem severity. The goal of the present study was to evaluate the reliability and validity of the Alcohol Purchase Task (APT), a RRE measure that uses hypothetical choices regarding alcohol purchases at varying prices (demand curves) to generate several indices of alcohol-related reinforcement. Participants were 38 college students who reported recent alcohol consumption. Both the raw alcohol purchase/consumption values and several of the computed reinforcement parameters (intensity & Omax) showed good to excellent 2-week test–retest reliability. Reinforcement parameters derived from both a linear-elasticity (Hursh, Raslear, Bauman, & Black, 1989) and an exponential (Hursh & Silberberg, 2008) demand curve equation were generally less reliable, despite the fact that both equations provided a good fit to participants’ reported consumption data. The APT measures of demand intensity (number of drinks consumed when price = 0), Omax (maximum expenditure), and elasticity (α) were correlated with weekly drinking, alcohol-related problems, and other self-report RRE measures (relative discretionary monetary expenditures toward alcohol and/or relative substance-related activity participation and enjoyment). Demand intensity was uniquely associated with problem drinking in a regression model that controlled for weekly consumption. These results provide support for the reliability and validity of the RRE indices generated with the APT. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献