Harmonic forms on manifolds with non-negative Bakry–Émery–Ricci curvature

In this paper we prove that on a complete smooth metric measure space with non-negative Bakry–Émery–Ricci curvature if the space of weighted L ² harmonic one-forms is non-trivial, then the weighted volume of the manifold is finite and the universal cover of the manifold splits isometrically as the product of the real line with a hypersurface.     

A Convolution Operator Related to the Generalized Mehler–Fock and Kontorovich–Lebedev Transforms

In this paper we study a generalization of an index integral involving the product of modified Bessel functions and associated Legendre functions. It is applied to a convolution construction associated with this integral, which is related to the classical Kontorovich–Lebedev and generalized Mehler–Fock transforms. Mapping properties and norm estimates in weighted L _p -spaces, 1 ≤ p ≤ 2, are investigated. An application to a class of convolution integral equations is considered. Necessary and sufficient conditions are found for the solvability of these equations in L ₂.     

Antioxidising activity of cinnamic acid derivatives against oxidative stress induced by oxidising radicals

Cinnamic acid and its derivatives react with hydroxyl radical (HO^?), in neutral medium, to give hydroxylation products, whether on the benzene ring or on the exocyclic chain, and decarboxylation products. The latter compounds are also obtained after oxidation of the same substrates by the SO₄^?? radical anion. Evidence was provided for the protecting effects afforded by cinnamic acid and hydroxylated derivatives against oxidative reaction mediated by HO^?. By using adenine as a model compound, the results obtained suggest that the high protective effect is due to an antioxidising cascade process. Copyright © 2013 John Wiley & Sons, Ltd.     

Study of ProtoPorphyrin IX Elimination by Body Excreta: A new Noninvasive Cancer Diagnostic Method?

This paper describes the elimination of porphyrins by feces. It was demonstrated that porphyrin accumulates substantially more in tumors than in normal tissues, and consequently more PPIX reaches the blood of patients and animals with tumors, and then, it needs to be eliminated. The fluorescence of feces revealed that there are large amounts of PPIX in the excreta of animals with cancer comparing with healthy animals. The autofluorescence of feces porphyrin extracted with acetone was analyzed using fluorescence spectroscopy of animals inoculated with DU145 cells into the prostate and healthy animals to monitor the PPIX concentration. Emission spectra were obtained by exciting the samples at 405 nm. Significant differences were observed in autofluorescence intensities measured in the 575–725 nm spectral regions for the studied groups. The results showed a noninvasive, simple, rapid and sensitive method to detect cancer by feces analysis.     

GC×GC/qMS analyses of Campomanesia guazumifolia (Cambess.) O. Berg essential oils and their antioxidant and antimicrobial activity

The present study investigated the essential oil obtained from Campomanesia guazumifolia (Cambess.) O. Berg, an aromatic plant used in Brazilian folk medicine. The chemical composition was performed by GC×GC/qMS. The antioxidant and antimicrobial activities were evaluated by DPPH and BCB and, MIC assays, respectively. Sixty-eight compounds were identified in the oil, where the major compounds were bicyclogermacrene (15%), globulol (5%) and spathulenol (5%). Sesquiterpene hydrocarbons (29 compounds) and oxygenated sesquiterpenes (20 compounds) were the most representative classes of terpenes. DPPH (IC₅₀ value 26.1 ± 0.5 μg/mL) and BCB (68.3 ± 1.5%) values indicated a significant antioxidant activity. The essential oil strongly inhibited Staphylococcus aureus (MIC 15 ± 0.1 μg/mL), Escherichia coli (MIC 25 ± 0.2 μg/mL) and Candida albicans (MIC 5 ± 0.1 μg/mL). The results give a deeper understanding of the chemical composition and report for the first time the antioxidant and antimicrobial potential of the C. guazumifolia essential oil.     

Colloidal semiconductor quantum dots: Potential tools for new diagnostic methods

We present and discuss the application of colloidal semiconductor quantum dots for diagnostic purposes, with special emphasis for cancer. We prepared and applied core-shell cadmium sulfide-cadmium hydroxide (CdS/Cd(OH)₂) semiconductor quantum dots in aqueous medium. Tissue and cells labeling was evaluated by laser scanning confocal microscopy as well as by conventional fluorescence microscopy. The procedure presented in this work, shown to be a promising tool for fast, low-cost and precise cancer diagnostic protocols.     

Polyhydroxybutyrate (PHB) Synthesis by <Emphasis Type="Italic">Spirulina</Emphasis> sp. LEB 18 Using Biopolymer Extraction Waste

The reuse of waste as well as the production of biodegradable compounds has for years been the object of studies and of global interest as a way to reduce the environmental impact generated by unsustainable exploratory processes. The conversion of linear processes into cyclical processes has environmental and economic advantages, reducing waste deposition and reducing costs. The objective of this work was to use biopolymer extraction waste in the cultivation of Spirulina sp. LEB 18, for the cyclic process of polyhydroxybutyrate (PHB) synthesis. Concentrations of 10, 15, 20, 25, and 30% (v/v) of biopolymer extraction waste were tested. For comparison, two assays were used without addition of waste, Zarrouk (SZ) and modified Zarrouk (ZM), with reduction of nitrogen. The assays were carried out in triplicate and evaluated for the production of microalgal biomass and PHB. The tests with addition of waste presented a biomass production statistically equal to ZM (0.79 g L^?1) (p?<?0.1). The production of PHB in the assay containing 25% of waste was higher when compared to the other cultivations, obtaining 10.6% (w/w) of biopolymer. From the results obtained, it is affirmed that the use of PHB extraction waste in the microalgal cultivation, aiming at the synthesis of biopolymers, can occur in a cyclic process, reducing process costs and the deposition of waste, thus favoring the preservation of the environment.     

Simultaneous on-line pre-concentration and determination of trace metals in environmental samples by flow injection combined with inductively coupled plasma mass spectrometry using silica gel modified with niobium(V) oxide

This work presents the development of an on-line pre-concentration system for simultaneous determination of Cd, Cu, Ni, V, Zn, Co and Pb in aqueous environmental samples and detection by inductively coupled plasma mass spectrometry. The system is based on cationic retention of the analytes onto a mini-column filled with silica gel modified with niobium(V) oxide. The effects of chemicals and flow variables have been investigated. The optimized operating conditions, selected as a compromise between sensitivity and analytical frequency were: sample pH 7.0, sample flow rate of 6.0mL min(-1), eluent flow rate of 2.0mL min(-1), and eluent (HNO(3)) concentration of 2.5mol L(-1). The relative standard deviation (n=7), enrichment factor and linear working range were 0.8-4.5%, 23.3-37.2 and 0.05-25.0microg L(-1), respectively. Limits of detection were between 0.01 and 0.03microg L(-1). The accuracy of the proposed method was checked with certified materials (NASS-4, NASS-5, CASS-4 and SRM 1643e). Values obtained were in accordance with those reported for the certified materials. Recovery was found to be in the range of 90-110% for a suit of water samples with variable matrices (seawater, tap water and ground water) collected in Florianopolis, Brazil.     

An improved two-stage optimization-based framework for unequal-areas facility layout

The unequal-areas facility layout problem is concerned with finding the optimal arrangement of a given number of non-overlapping indivisible departments with unequal area requirements within a facility. We present an improved optimization-based framework for efficiently finding competitive solutions for this problem. The framework is based on the combination of two mathematical optimization models. The first model is a nonlinear approximation of the problem that establishes the relative position of the departments within the facility, and the second model is an exact convex optimization formulation of the problem that determines the final layout. Aspect ratio constraints on the departments are taken into account by both models. Our computational results show that the proposed framework is computationally efficient and consistently produces competitive, and often improved, layouts for well-known instances from the literature as well as for new large-scale instances with up to 100 departments.     

Maximum Principle for the Regularized Schrödinger Operator

In this paper we present analogues of the maximum principle and of some parabolic inequalities for the regularized time-dependent Schrödinger operator on open manifolds using Günter derivatives. Moreover, we study the uniqueness of bounded solutions for the regularized Schrödinger–Günter problem and obtain the corresponding fundamental solution. Furthermore, we present a regularized Schrödinger kernel and prove some convergence results. Finally, we present an explicit construction for the fundamental solution to the Schrödinger–Günter problem on a class of conformally flat cylinders and tori.