Living on the Moon: Topological Optimization of a 3D-Printed Lunar Shelter

Long-term permanence of human beings on the surface of the Moon poses several problems, due both to the health hazards against which it is necessary to take shelter, and to the economical sustainability of the mission. We briefly describe the mathematical and numerical tools needed to project a 3D-printed lunar shelter aimed at overcoming such problems, and we present and discuss the resulting optimized architectural design, provided by Foster + Partners.     

Physical and Antimicrobial Properties of Tapioca Starch-HPMC Edible Films Incorporated with Nisin and/or Potassium Sorbate

The antimicrobial effectiveness of nisin and potassium sorbate, incorporated individual and combined, in films made with tapioca starch and its mixtures with hydroxypropyl methylcellulose were studied. The combination of antimicrobials was more effective against Listeria innocua and Zygosaccharomyces bailii than their individual incorporation, with the added advantage of providing greater inhibitory spectrum. The effect of the formulation on some physical properties was also evaluated. The blended biopolymers-based films showed an increase of stress (σ _r) and elastic modulus (E) but a decrease of the strain at break (ε _r). In turn, the water vapour permeability and solubility in water were enhanced. In addition, these films were clearer than those made only with starch. It must be remark that, despite the antimicrobial agents modified films physical properties, producing a lower σ _r and E, a higher ε _r, solubility and darker films, they maintained a suitable behaviour as a packaging material.     

Development and Comparison of Sample Preparation Techniques for Chromatographic Analysis of Sulfonamide Residues in Bovine Milk

Most studies to determine sulfonamide residues in milk samples have used solid-phase extraction as the sample preparation technique. However, the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method, introduced in 2003, has been used in the extraction of various compounds in food matrices. This study aimed to evaluate two sample preparation techniques: solid-phase extraction and QuEChERS, for chromatographic analysis of sulfonamides (sulfathiazole, sulfamethazine, and sulfadimethoxine) in bovine milk. The chromatographic parameters and the QuEChERS extraction procedure were developed by using different experimental designs, obtaining good peak resolution, recovery, precision, accuracy, linearity, selectivity, and limits of detection and quantification. In contrast, using solid-phase extraction, acceptable recoveries and selectivity were not achieved, despite the number of articles published that have applied this sample preparation technique for sulfonamide analysis. As a result of the experiments performed, probably sulfonamides are retained together with other components of the matrix in the sample pretreatment step (prior to its addition in the cartridge containing solid phase), which is an important part of solid-phase extraction with raw whole milk. Therefore, QuEChERS is a better method than solid-phase extraction for the analysis of sulfonamide residues in milk. Validation tests demonstrated that the method is appropriate, within the maximum residue limit (0.1 mg kg^?1). Moreover, it was possible to use a lower amount of solvent compared with previously published articles (6 mL against 10 or 15 mL).     

Combined effects of Lactobacillus casei inoculum, modified atmosphere packaging and storage temperature in controlling Aeromonas hydrophila in ready-to-use vegetables

Carbon dioxide concentration, Lactobacillus casei inoculum size and storage temperature were varied according to a Central Composite Design in order to assess the effects of these variables and their interactions on the growth of Aeromonas hydrophila and lactic acid bacteria in ready-to-use mixed salad vegetables packaged under modified atmosphere. The growth curve parameters, modelled according to the Gompertz equation, were analysed to generate polynomial equations. The model obtained emphasized the role of L. casei inoculum size in controlling A. hydrophila and permitted identification of appropriate combinations of the selected variables to reduce A. hydrophila survival. The use of these hurdles may increase the shelf-life and the microbiological safety of ready-to-use vegetables.     

Effect of sub-inhibitory concentrations of antibiotics on the hemolytic activity of Legionella

An in vitro test for the antiproliferative effect of human leukocyte interferon (IFN-alpha) was performed in primary cultures of tumor cells obtained from 32 patients with either malignant melanoma (13), renal carcinoma (4) or bladder carcinoma (15). Our results demonstrated activity of IFN in all three groups of solid tumors. However, appreciable differences in sensitivity to antiproliferative effect of IFN between individual tumors of the same type were found. The potential of this antiproliferative test for prediction of treatment response in IFN-therapy is discussed.     

Covalent binding of a selective agonist irreversibly activates guinea pig coronary artery A2 adenosine receptors

Experiments employing guinea pig heart Langendorff preparations compared the coronary vasoactivity of a functionalized congener of adenosine, 2-[(2-aminoethyl-aminocarbonylethyl)phenylethylamino]-5'-N-e thyl- carboxamidoadenosine, APEC, with the vasoactivity of the product of the reaction of APEC with 1,4-phenylene-diisothiocyanate, 4-isothiocyanatophenylaminothiocarbonyl-APEC (DITC-APEC). Previous experiments showed that whereas APEC binds reversibly to the A2A adenosine receptor of brain striatum, DITC-APEC binds irreversibly. APEC caused concentration-dependent coronary vasodilation that persisted unchanged when agonist administration continued for up to 165 min, but promptly faded when the agent was withdrawn. The unselective adenosine receptor antagonist 8-(4-sulfophenyl)theophyline (8-SPT) antagonized the vasoactivity of APEC. By contrast, DITC-APEC (0.125-1.0 nM) caused progressive, concentration-independent vasodilation that persisted unchanged for as long as 120 min after the agent was stopped and that was insensitive to antagonism by subsequently applied 8-SPT. However, perfusion of the heart with buffer containing 0.1 mM 8-SPT strongly antagonized the coronary vasodilatory action of DITC-APEC given subsequently. Such observations indicate that the covalent binding of DITC-APEC causes irreversible activation of the guinea pig coronary artery A2A adenosine receptor. Neither APEC nor DITC-APEC appeared to desensitize the coronary adenosine receptor during two or more hours of exposure to either agonist.     

Features of the transformation of Hg by heterogeneous photocatalysis over TiO2

UV/TiO₂ photocatalysis of 0.5 mM mercuric aqueous solutions has been analyzed starting from Hg(NO₃)₂, Hg(ClO₄)₂ and HgCl₂ at different pH (3, 7 and 11) and in the presence or absence of oxygen. Profiles of Hg^II concentration with time were characterized by a relatively rapid initial conversion followed by a decrease or an arrest of the rate, the shape of profiles changing with the conditions. Conversions at 60 min and initial quantum efficiencies have been found dependent on the initial conditions and type of mercuric salt. The faster transformation took place at pH 11 for all salts. A good transformation yield is observed also for HgCl₂, which behaves differently to the other two salts, at pH 3 under nitrogen and pH 7 (N₂ or O₂). Inhibition by oxygen was observed in acid and neutral media but not at basic pH. When the conversion was 50% or more, pale or dark gray solids were deposited on the catalyst, identified as mixtures of Hg⁰, HgO or Hg₂Cl₂. A unique kinetic scheme could not be defined, which seemed to depend on the nature of the mercury salt, the ambient conditions and the type of deposit. Implications of the application of the technique to real systems are discussed.     

Spatial contiguity, not cue-to-consequence, is the issue in taste-potentiated noise-illness associations: Comment on Holder, Bermudez-Rattoni, and Garcia (1988).

M. D. Holder et al (see record 1988-28622-001) allege to have failed to corroborate findings from our laboratory (S. R. Ellins et al and Ellins and S. von Kluge; see PA, Vols 73:3082 and 74:24095) that taste-potentiated noise–illness associations can be established under conditions of spatial contiguity. We maintain that Holder et al have provided additional experimental support for our contention that spatial contiguity is an important factor in the taste-potentiation of nongustatory stimuli. In addition, we take issue with their conclusion that the results of our research are incompatible with the conditioning principle of cue-to-consequence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)