Did Chemisorption Become an Obsolete Method With Advent of Tem? Comparison of Mean Particle Size and Distribution of Silver on Alumina

Abstract  

Silver particle size and dispersion on a Ag/Al₂O₃ for HC-SCR were examined by means of chemisorption and TEM. Experimental results showed that determination of the accurate mean particle size (mps) is challenging and that the both applied methods have specific characteristics increasing the inaccuracy in the results which has to be taken into account in evaluation of catalytic activity. The results from TEM imaging were found to depend highly on the mode in which the surface was scanned (bright field versus dark field). Generally the point resolution was higher in dark field but the obtained mps did not increased along with the increasing silver loading. The main limitation with the O₂-chemisorption was related to the choice of the stoichiometric factor between the adsorbent and silver atoms. However, together these techniques support each other and help to give a more realistic picture of the mean silver particle size, distribution and indications of the oxidation states on the alumina support.     

Influence of the Adoption and Use of Social Media Tools on Absorptive Capacity in New Product Development

Abstract:

In this article, we discuss how the adoption and use of social media tools influences new product development (NPD). Our aim is specifically to consider how an organization's absorptive capacity is influenced by using social media tools. Based on a two-phase data collection process comparing the situation before and after adoption of social media tools in three organizations, we conclude that the amount of accessible knowledge and the number of ideas increases as an organization's ability to find and access various sources of intra-organizational expertise increases, thus, increasing knowledge acquisition and assimilation. Consequently, we infer that organizational absorptive capacity rises and is linked to improvement in new product development.     

Evaluation of taste active peptides and amino acids from anchovy proteins in fish sauce by in silico approach

Food Science and Biotechnology - Enzymatic activity and microbial fermentation play a prominent role in the bioconversion of complex muscle tissue into smaller units of peptides and amino acids,...     

Yeasts associated with plums and their potential for controlling brown rot after harvest

Bacterial and yeast antagonists isolated from fruit surfaces have been effective in controlling various post‐harvest diseases, and several microbial antagonists have been developed into commercial products. Our knowledge of the fruit microbial community, with the exception of grapes, apples and some citrus fruit, is rudimentary and the potential of the resident yeasts for biocontrol remains largely unknown. We determined the occurrence of yeasts on plum surfaces during fruit development from the pre‐hardening stage until harvest for 2 years. A total of 16 species from 13 genera were isolated. Species from three genera, basidiomycetes Rhodotorula (29.5%) and Sporidiobolus (24.7%) and the dimorphic ascomycete genus Aureobasidium (24.7%), constituted 78.7% of all isolations and were recovered throughout fruit development, while Cryptococcus spp. constituted only 6.2% of the total plum isolates. The yeast community in the final sampling was significantly different from the first three samplings, reflecting a rapidly changing fruit habitat during the maturation of fruit. For example, Hanseniaspora, Pichia, Zygosaccharomyces and Wickerhamomyces occurred only on the most mature fruit. Screening of the yeasts for antagonistic activity against Monilinia fructicola, a fungus that causes brown rot, revealed a range of biocontrol activities. Several isolates provided complete control of the decay on plums, challenged with a pathogen suspension of 10³ conidia/ml and > 90% of control on fruit inoculated with the pathogen at a concentration 10 times higher. Some of the best antagonists included A. pullulans and R. phylloplana. Populations of both of these antagonists increased rapidly by several orders of magnitude in wounds of plums incubated at 24ºC and 4ºC. Our results indicate that plum surfaces harbour several yeast species, with excellent potential for use in biological control of brown rot of stone fruits. Published 2014. This article is a U.S. Government work and is in the public domain in the USA     

The influence of depressive symptoms on smoking cessation among African Americans in a randomized trial of bupropion.

The influence of depressive symptoms on smoking cessation was examined among 600 African American smokers who participated in a randomized, placebo-controlled trial of sustained-release bupropion hydrochloride. Depressive symptoms were assessed at baseline, at week 6 (end of treatment), and at 6-month follow-up. The study examined three separate questions: (a) Whether depressive symptom levels were related to smoking cessation, (b) whether bupropion was more effective for smokers who had higher depressive symptoms at baseline (i.e., a moderator model), and (c) whether changes in depressive symptoms would account for the efficacy of bupropion for smoking cessation (i.e., a mediator model). Depressive symptoms at baseline were not predictive of cessation; however, increases in depressive symptoms from baseline predicted reduced cessation at the end of treatment, and higher depressive symptoms at week 6 and month 6 were associated with a reduced likelihood of smoking cessation at those time points. The moderator model was not supported, but the mediation analyses indicated that alleviation of depressive symptoms partly accounted for bupropion-assisted smoking cessation at end of treatment. Results extend prior findings to African American smokers and suggest that clinicians consider increases in depressive symptoms after quitting rather than baseline depressive symptoms in predicting risk of treatment failure. Results also suggest that even though bupropion may facilitate cessation in part by reducing depressive symptoms, it appears to be no more effective for more depressed smokers, and that mechanisms other than depressive symptom alleviation account for most of its efficacy.     

Low-temperature aerosol flow reactor method for preparation of surface stabilized pharmaceutical nanocarriers

Nanoparticles can be used to improve the delivery of many drugs, especially peptides and proteins. Although several methods are available for polymeric nanoparticle preparation, there are few single-stage processes that produce dry, solid nanoparticles that can be easily re-dispersed in pharmaceutical vehicles. The aerosol flow reactor method is a single-stage process that has been used for the preparation of multicomponent, coated nanoparticles under uniform temperature and gas flow field. However, it is traditionally used with high synthesis temperatures. In the present study, the aerosol flow reactor method was further optimized for processing and surface stabilization of pharmaceutical nanoparticles containing temperature sensitive biomolecules. In the developed method, drug-loaded carrier nanoparticles consisting of a biodegradable polymer (Eudragit L100) and a drug (phenylephrine hydrochloride) were first produced by aerosol droplet drying and subsequently coated in the gas phase. The carrier particles were coated with l-leucine in order to inhibit agglomeration of the nanoparticles in solutions before administration. In the coating process, a side stream of l-leucine vapor was directed into the main aerosol flow containing the drug-loaded carriers. The mixing with the main flow at ambient temperature induced a supersaturation of l-leucine vapor and condensation on the carrier particles. The results demonstrate that solid, hydrodynamically stable drug-loaded polymeric nanoparticles can be produced with a thin l-leucine coating. The low process temperature enables the surface engineering of particles loaded with temperature sensitive drugs or bioactive materials to be utilized for drug delivery purposes.     

Time course of incorporation of 20-carbon polyunsaturated fatty acids in a human keratinocyte cell line

Human keratinocytes (NCTC 2544) in culture were labeled with equal amounts of either¹⁴C-arachidonic acid,¹⁴C-dihomo-γ-linolenic acid or¹⁴C-eicosapentaenoic acid. At various time points, the incubations were stopped and the distribution of the¹⁴C-fatty acids was analyzed. All these eicosanoid precursor fatty acids were effectively incorporated into the cellular lipids of the keratinocytes, and the major radiolabeled individual lipid fraction was phosphatidylethanolamine. The distributions of arachidonic acid and dihomo-γ-linolenic acid within cellular lipids were rather the same. However, less eicosapentaenoic acid than either arachidonic acid or dihomo-γ-linolenic acid was incorporated into the phospholipids and, correspondingly, more eicosapentaenoic acid was incorporated into the nonphosphorus lipids. In the phosphatidylinositol + phosphatidylserine fraction, there was significantly less eicosapentaenoic acid than either arachidonic acid or dihomo-γ-linolenic acid. The present study suggests that these eicosanoid precursor fatty acids are effectively incorporated into the human keratinocytes and that the pattern of incorporation and distribution of eicosapentaenoic acid appears to differ slightly from that of either arachidonic acid or dihomo-γ-linolenic acid.     

Altered alveolar macrophage function in calorie-restricted rats

The capacity of four chicken lines (Y11, L2, B13, PA12) to control Salmonella enteritidis (SE) phage type 4 (PT4) systemic colonization was investigated. Thirteen-week-old chickens were intravenously inoculated with 10(6) SE colony-forming units, and the levels of SE colonization were determined at various time intervals after inoculation in liver, spleen, genital organs, and ceca. The course of SE infection showed a rapid contamination of liver, spleen, and genital organs, whereas the ceca were infected later. A significant (P < 0.001) effect of the chicken line on levels of SE was detected on day 3 postinoculation (PI) in liver and ceca, on day 10 PI in ceca, and on day 15 PI in spleen. Because an early control of systemic Salmonella infection by the Ity/Nramp1 gene has been demonstrated in mice, we aimed to study the early resistance of chickens to SE. As a consequence, we then focused our study on the between- and within-line variabilities of SE levels on day 3 PI. According to the SE levels in liver on day 3 PI, the chicken lines could be classified as susceptible (Y11 and L2) or resistant (PA12 and B13). This early variability was explored in resistant B13 and susceptible L2 lines. Differences between these two lines were confirmed in liver but not in ceca. A large within-line variability was observed in all organs of these two lines. The genetic origin of this variability will have to be determined as a prerequisite to an eventual selection.