Surface Functionalization of Face Masks with Cold Plasma and Its Effect in Anchoring Polyphenols Extracted from Agri-Food

To improve the capability of non-woven polypropylene-based fabric (NWF-PP) used for face mask production to retain active biomolecules such as polyphenols, the surface functionalization of NWF-PP–directly cut from face masks–was carried out by employing cold plasma with oxygen. The nature/structure of the functional groups, as well as the degree of functionalization, were evaluated by ATR-FTIR and XPS by varying the experimental conditions (generator power, treatment time, and oxygen flow). The effects of plasma activation on mechanical and morphological characteristics were evaluated by stress–strain measurements and SEM analysis. The ability of functionalized NWF-PP to firmly anchor polyphenols extracted from cloves was estimated by ATR-FTIR analysis, IR imaging, extractions in physiological solution, and OIT analysis (before and after extraction), as well as by SEM analysis. All the results obtained converge in showing that, although the plasma treatment causes changes–not only on the surface–with certain detriment to the mechanical performance of the NWF-PP, the incorporated functionalities are able to retain/anchor the active molecules extracted from the cloves, thus stabilizing the treated surfaces against thermo-oxidation even after prolonged extraction.     

Optimization of Lipid Extraction from Spirulina spp. by Ultrasound Application and Mechanical Stirring Using the Taguchi Method of Experimental Design

The present study uses the Taguchi method of experimental design to optimize lipid extraction from Spirulina spp. by ultrasound application and mechanical stirring. A Taguchi L₉ orthogonal array was used to optimize various parameters, such as methanol: chloroform (M:C) ratio, biomass: solvent ratio, and extraction time for lipid extraction. The results were analyzed using the signal-to-noise (S/N) ratio and analysis of variance (ANOVA). The biomass: solvent ratio significantly influenced lipid content (p < 0.05) with 92.1% and 92.3% contributions to the lipid and S/N ratio data, respectively. The extraction time presented a contribution value of 5.0%, while the M:C ratio presented the most negligible contribution of 0.4% for S/N data. The optimum extraction conditions were: M:C ratio of 1:1, biomass: solvent ratio of 1:60, and extraction time of 30 min. The predominant fatty acids were palmitic acid (44.5%), linoleic acid (14.9%), and gamma-linolenic acid (13.4%). The confirmation experiments indicated a lipid content of 8.7%, within a 95% confidence interval, proving the Taguchi method’s effectiveness in optimizing the process parameters for lipid extraction.     

反应N(2D)+H2→NH+H和N(2D)+D2→ND+D的立体动力学理论研究.

基于Ho等人的精确势能面(J. Chem. Phys. 119, 3063(2003))研究,运用准经典轨线方法计算了21.3 kJ/mol碰撞能下反应N(²D)+H₂→NH+H和N(²D)+D₂→ND+D的产物与反应物之间的矢量相关．发现两个反应的产物角分布都是前向和后向呈现峰值分布,产物的转动角动量矢量j′不仅是取向的,而且是在y轴负方向上定向的．两个反应显示出的同位素效应主要归因于同位素质量的差别．     

Molecular dynamics study of CaCl2 in methanol

The effective potential to describe interactions between the calcium ion and methanol molecule was derived from a potential energy surface. The energy surface was constructed from more than 10,000 points obtained from ab initio calculations, performed at the MP2/6-31G(d,p) level using Gaussian98. The derived effective potential and the Palinkas-Hawlicka-Heinzinger methanol model were employed in the molecular dynamics (MD) simulation of 0.25 M CaCl(2) solution in methanol at 298 K. Average distances between ions and the methanol sites--oxygen and carbon atoms--obtained from MD simulation agreed excellently with the X-ray data. The coordination number of the cation, greater as compared with the experimental results, is in accord with its concentration dependence.     

Synthesis and characterization of novel (9H‐fluoren‐9‐ylamino) carbonylaminomethylphosphonic acid

The new α‐aminophosphonic acids are synthesized, reacting (9H‐fluoren‐9‐yl)urea with formaldehyde and phosphorus trichloride. (9H‐Fluoren‐9‐yl)urea was prepared from spiro(fluoren‐9,4′‐imidazolidine)‐2′,5′‐dione by alkaline hydrolysis with Ba(OH)₂. The structure of the title compounds was proved by means of IR, ¹H, ¹³C, and ³¹P NMR spectroscopy. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:719–722, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20500     

An algorithm for computing minimal curves

Let ?³ be the 3-dimensional projective space over an algebraically closed field K of characteristic 0, and R be the graded polynomial ring K[x ₀,x ₁,x ₂,x ₃]. If C is a curve of ?³, let M _c := ⊕ H ^l I _C (n) be its Hartshorne-Rao module: it is a graded R-module of finite length which, up to a shift in degrees, characterizes the biliaison class of C. M. Martin-Deschamps &; D. Perrin (Sur la classification des courbes gauches. Astérisque 184–185 (1990)) have proved that in every biliaison class of non arithmetically Cohen-Macaulay curves there exists a minimal curve, unique up to a deformation with constant cohomology and Hartshorne-Rao module, that is a curve C such that, if C ₁ is any curve in the biliaison class of C, then M _{C 1} = M _c(?n), with n ≧ 0. They have moreover given an algorithm for the computation of a minimal curve, based on the computation and the analysis of the minors of given orders of some submatrices of the second syzygy matrix σ ₂ of M. The aim of this paper is to give an improvement to the algorithm for computing a minimal curve of a given Hartshorne-Rao module. The key remark is that the information obtained from σ ₂ can analogously be obtained from the matrix f(σ ₂) with entries in the polynomial ring K[u], where f:R → K[u] is a map which evaluates the variables of R to random linear polynomials in K[u]. The advantage of this approach is first, that the computations are done in a simpler polynomial ring and second, that in K[u]|we can take advantage of the Smith Normal Form algorithm to analyze the structure of the minors of the given matrices. The algorithm is therefore probabilistic but rather efficient and allows to compute (the invariants of) a minimal curve associated to modules whose syzygies matrices are considerably large. The algorithms presented here have been partially implemented and tested in the computer algebra systems CoCoA, Maple and Macaulay.     

Surfactant dependent morphology of polymeric capsules of perfluorooctyl bromide: influence of polymer adsorption at the dichloromethane-water interface

In a strategy to develop more stable ultrasound contrast agents (UCAs), we have designed a process to obtain nano/microcapsules with a single core of liquid perfluorocarbon within a biodegradable polymeric shell of homogeneous thickness. During the optimization of perfluorooctyl bromide (PFOB) encapsulation by solvent emulsion-evaporation, a marked influence of surfactants has been observed. While sodium cholate leads to spherical capsules of homogeneous thickness, sodium taurocholate induces to the formation of “acorn”-particles with one hemisphere of PFOB and another one of PLGA, and polyvinyl alcohol is responsible for the coexistence of both morphologies. Whereas the theoretical model proposed by Torza and Mason [J. Colloid Interface Sci. 33 (1970) 67] fails to predict the observed morphologies, microscopic observations of the evaporation and interfacial tension measurements provide an insight into the mechanism of formation of these structures. Most probably, there is a competition between PLGA and the surfactant stabilizing the emulsion at the dichloromethane–water interface. If PLGA is able to adsorb at the interface, the core–shell morphology is obtained, otherwise the acorn morphology is preferentially formed. When the surfactant rearrangement at the interface is long (>30 min), a coexistence of morphologies can be obtained.     

Validation of the Tessier scheme for speciation of metals in soil using the Bland and Altman test

The Tessier extraction method was used for speciation of Cu, Pb, Zn, As, Fe and Mn in a large concentration range in contaminated soil with various mineralogical compositions. The results were compared by X-ray fluorescence spectrometry (XRF) as a reference method using the Bland and Altman test. A sum of five fractions (exchangeable, bound to carbonates, Fe-Mn oxides, organic matter and residual forms) was compared with the total content determined on solid matrix by the reference method. A good agreement between the methods in the whole concentration range was found for Cu, Zn, As, and Fe. For Mn and Pb, XRF was found suitable to verify the sequential extraction only for concentrations above 250 mg kg⁻¹. This was a consequence of a poorer reproducibility of Pb extraction using the Tessier scheme due to a great difference in the mineralogical composition and the diversity of the Pb species identified in soil. The poorer result of Mn was attributed to the spectral interference of Fe in XRF. Presented at the 34th International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 21–25 May 2007.