Carbonyl levels in indoor and outdoor air in Mexico City and Xalapa,Mexico

Carbonyl compounds in air were measured at two houses, three museums, and two offices. All sites lacked air-conditioning systems. Although indoor and outdoor air was measured simultaneously at each site, the sites themselves were sampled in different dates. Mean concentrations were higher in indoor air. Outdoor means concentrations of acetone were the highest in all sites, ranging from 12 to 60 microg m(-3). In general, formaldehyde and acetaldehyde had similar mean concentrations, ranging from 4 to 32 and 6 to 28 microg m(-3), respectively. Formaldehyde and acetone mean indoor concentrations were the highest, ranging from 11 to 97 and 17 to 89 microg m(-3), respectively, followed by acetaldehyde with 5 to 47 microg m(-3). Formaldehyde and acetaldehyde had the highest mean concentration in the offices where there were smokers. Propionaldehyde and butyraldehyde concentrations did not show definite differences between indoor and outdoor air. In general, the highest outdoor and indoor hourly concentrations were observed from 10:00 to 15:00 h. Mean indoor/outdoor ratios of carbonyls exceeded 1. Formaldehyde and acetaldehyde risks were higher in smoking environments.     

Identification and characterisation of coumarins from the roots of Angelica dahurica and their inhibitory effects against cholinesterase

The current research was the first to investigate coumarins and their cholinesterase inhibitory activities from Angelica dahurica roots. The ethanol extract of this species (100 μg/ml) possessed inhibitory effects against human acetylcholinesterase (hAChE) and butylcholinesterase (BChE) with IC₅₀ values of 26.40 and 14.71 μg/ml, respectively. To evaluate the compounds responsible for these activities, the ethanol extract was chromatographed, which yielded ten coumarins, including isoimperatorin (1), imperatorin (2), senbyakangelicol (3), oxypeucedanin (4), byakangelicol (5), t-OMe-oxypeucedanin hydrate (6), t-OMe-byakangelicin (7), angelol H (8), byakangelicin (9), and oxypeucedanin hydrate (10). Among them, coumarin 5, 7, and 9 showed potent inhibition with IC₅₀s of 46.3, 39.0, and 55.4 μM (hAChE) as well as 45.2, 25.6, and 42.4 μM (BChE), respectively. Moreover, their inhibition modes against two cholinesterases exhibited noncompetitive. The individual coumarin contents were remarkable differences, especially, oxypeucedanin (4) was the most predominant compound (8710.9 μg/g), representing approximately 55.0% of the total content.     

Understanding the role of digital commons in the web; The making of HTML5

The last version of Web’s hypertext standard has been developed from 2004 to 2014. During this era, HTML5 has experienced different crossroads due to the variety of motivations and needs that the main stakeholders interested in its development had. On October 2014, the standard got official by the W3C and closed a period of uncertainty around the future of the Web but at the same time, this agreement also introduced a major change in the own conception of the hypertext’s standard. In this paper we review the current status of digital commons on the Web and the development of HTML5. We also confront this analysis with several semi-structured interviews carried out with different experts in web development that represent at the same time different players of Web’s value chain.We argue that the development of HTML5 represents a new digital commons that prevented the proliferation of proprietary software that took place during the “Web 2.0” period. We claim that the World Wide Web promotes the development of new digital commons due to its own basis as a non-proprietary socio-technological platform. We also conclude that the development of standards and non-proprietary digital technologies is of outmost importance for the future of web business models that are fueled by major digital players.     

Nanocomposite films and coatings produced by interaction between graphite oxide and Congo red

Nanocomposite films and coatings were produced from the aqueous solutions containing different proportions of graphite oxide (GO) and Congo red by filtering through a polycarbonate membrane filter into alkaline media. They were examined by electron microscopy, Raman and FTIR spectroscopy, XRD, contact angle, and electrical conductivity measurements. It was established that the Congo red is able to interact through its amino groups with different functional groups of GO to form larger moieties composed of the nanoplatelets of GO. Raman spectroscopy revealed quinoid-like ring structure for dye adhering to the GO. In the case when the interaction occurs with the terminal functional groups located on the edges of the nanoplateletes of GO, larger crystallites in the nanocomposite are formed. The interaction between the Congo red and functional groups of GO situated in a basal plane leads to more compact structure of the nanocomposite. Pulsed laser treatment was used to reduce GO to graphene. Raman spectra of laser treated areas show positive effect of addition of the Congo red on the graphene yield in nanocomposite coatings after the laser treatment.     

Influence of the geometric factors of the experimental device used in suspension polymerization on the properties of poly(styrene‐co‐divinylbenzene) microparticles

The prediction of the final particle size for reactive systems such as the reactions of suspension polymerization is a complex matter. Thus, the preparation of very small microparticles is specially challenging, probably because of the coalescence of the polymeric beads taking place during the later stages of the polymerization. In this work, very small gel‐type styrene‐co‐divinylbenzene beads were synthesized by using a previously determined set of experimental synthesis conditions in which the stabilization of the dispersion of the monomeric droplets was ensured, and, under these conditions, the factors related to the geometry of the experimental device were modified to determine their actual effect on the final size of the microparticles. From the experimental results, a very simple and useful model was obtained that was able to predict the final size of the microparticles as a function of the values of the geometric factors of the reactor. This model indicates that the most influential factors in the final size of the microparticles are the liquid depth inside the reactor and the stirrer diameter; thus, an increase in the liquid depth produces larger particles, and, conversely, the particle size decreases when using larger stirrer diameters. Additionally, the model permits the design of polymerization experiments aimed at obtaining microparticles with a diameter smaller than 50 μm. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Modulation of MDR1 and MRP3 Gene Expression in Lung Cancer Cells after Paclitaxel and Carboplatin Exposure

Carboplatin-paclitaxel is a reference regimen in the treatment of locally advanced or disseminated non-small cell lung cancer (NSCLC). This paper discusses the multidrug resistance developed with this drug combination, which is one of the major obstacles to successful treatment. In order to understand and overcome the drug resistance pattern of NSCLC after carboplatin plus paclitaxel exposure, levels of mRNA expression of multidrug resistance 1 (MDR1) and multidrug resistance-associated protein 3 (MRP3) were investigated in primary NSCLC cell lines (A-549 and A-427) and a metastasis-derived NSCLC cell line (NODO). Our results showed that exposure of the three NSCLC lines to plasma concentrations of paclitaxel (5 μM) produced an increase in MDR1 expression, while MRP3 showed no alteration in expression. By contrast, the same cells exposed to carboplatin plasma concentrations (30 μM) showed overexpression of MRP3. In these cells, MDR1 showed no expression changes. Interestingly, the combination of both paclitaxel and carboplatin caused increased expression of the MDR1 drug resistance gene rather than the individual treatments. These results suggest that carboplatin and paclitaxel may induce drug resistance mediated by MDR1 and MRP3, which may be enhanced by the simultaneous use of both drugs.     

Thermogravimetric characterization of tyrosine and catechol adsorbed on montmorillonite

Thermogravimetric analysis is suggested as an essential methodology for studying the interaction between montmorillonite-type clays and organic molecules such as amino acids and phenolic compounds. In this work, two commercial clays, a bentonite and a montmorillonite commercially called K10, were separately put in contact with solutions of catechol and tyrosine. After the contact with the organic molecules, the powders were characterized by X-ray diffraction, infrared spectroscopy, nitrogen adsorption at 77?K, scanning electron microscopy, and thermogravimetric analysis. The thermal stability of the organic molecules on the particles’ surface depended mainly on the type of the montmorillonite clay used. This characteristic can be associated with the adsorption strength. The results show the importance of the thermogravimetric analysis for choosing the appropriate clay to be used in environmental studies or in the elaboration of industrial materials.     

Control of Listeria monocytogenes in boned dry-cured ham by E-beam treatment

Boning of dry-cured hams involves additional handling which increases the risk of contamination with Listeria monocytogenes. This work studies the ability of E-beam to eliminate this pathogen from boned dry-cured ham (BDH). The destruction kinetics of four L. monocytogenes strains (S2, S4-2, S12-1, and S7-2) and L. innocua NCTC 11288 as a surrogate were determined at doses up to 3 kGy. L. innocua and L. monocytogenes S4-2 were the most radioresistant (D-value = 0.55 kGy). E-beam penetration was studied in blocks extracted from BDH and irradiated with 2–6 kGy. The bilateral treatment of 2 kGy allows the required dose (1.32 kGy) to be absorbed in the innermost part of the block to achieve the food safety objective of “zero tolerance” for this microorganism. This listericidal treatment was also confirmed in whole BDH intentionally contaminated with L. innocua. The sensory analysis of irradiated BDH showed off-odors that were imperceptible after 15 days of storage at 4°C.