Impact of gas chromatography and mass spectrometry combined with gas chromatography and olfactometry for the sex differentiation of Baccharis articulata by the analysis of volatile compounds

The Baccharis genus has more than 400 species of aromatic plants. However, only approximately 50 species have been studied in oil composition to date. From these studies, very few take into consideration differences between male and female plants, which is a significant and distinctive factor in Baccharis in the Asteraceae family. Baccharis articulata is a common shrub that grows wild in south Brazil, northern and central Argentina, Bolivia, Paraguay and Uruguay. It is considered to be a medicinal plant and is employed in traditional medicine. We report B. articulata male and female volatile composition obtained by simultaneous distillation–extraction technique and analyzed by gas chromatography with mass spectrometry. Also, an assessment of aromatic differences between volatile extracts was evaluated by gas chromatography with olfactometry. The results show a very similar chemical composition between male and female extracts, with a high proportion of terpene compounds of which β‐pinene, limonene and germacrene D are the main components. Despite the chemical similarity, great differences in aromatic profile were found: male plant samples exhibited the strongest odorants in number and intensity of aromatic attributes. These differences explain field observations which indicate differences between male and female flower aroma, and might be of ecological significance in the attraction of pollinating insects.     

Gamma radiation effects on mechanical properties and morphology of a polyurethane derivate from castor oil

In this study, an adhesive of a polyurethane derivate from castor oil was irradiated with gamma radiation from a ⁶⁰Co source, at doses from 0.2 to 25 kGy. This adhesive polyurethane is considered for use in hospital furniture because it does not liberate dangerous solvents. Hardness and elastic modulus were measured by instrumented indentation with a pyramidal Berkovich indenter, using loads from 0.08–40 mN with a nanoindenter XP. The instrumented indentation hardness was 110 MPa for an untreated sample, increasing to 124 MPa after irradiation with 25 kGy, at penetration depths of about 5 μm. The increases in elastic modulus induced by radiation were less pronounced. This polyurethane is naturally cross-linked and the relative modifications in the hardness are attributed to an additional cross-linking process induced by radiation. X-ray diffraction indicates a slight increase in crystallinity. The roughness measured by atomic force microscopy increases after gamma irradiation.     

Synthesis,structural characterization,and spectroscopic properties of the ortho,meta, and para isomers of 8‐(HOCH2‐C6H4)‐BODIPY and 8‐(MeOC6H4)‐BODIPY

Fluorescent members of the 4, 4‐difluoro‐4‐bora‐3a, 4a‐diaza‐s‐indacene (BODIPY) family are widely used for a range of markers, dyes, and sensors. The capacity to substitute the basic framework is an attractive feature permitting a range of differently substituted materials to be formed. New isomeric BODIPYs, o‐, m‐, and p‐8‐[R‐C₆H₄]‐BODIPY (R = CH₂OH, 2a (o), 2b (m), 2c (p); R = OMe, 3a (o), 3b (m), 3c (p)), have been synthesized and characterized by nuclear magnetic resonance, absorbance and emission spectroscopy, and single crystal X‐ray diffraction. The o‐isomers have a very high quantum yield emission in non‐polar solvents, while the m‐ and p‐ analogs showed weak fluorescence under the same conditions. Spectroscopic analysis, as well as X‐ray structural characterization, suggested that substitution in the ortho‐position of the phenyl ring is sufficient to increase the steric hindrance and hence impede the rotation of the phenyl moiety about the 8C‐C axis, thereby favoring radiative compared to non‐radiative relaxation. Copyright © 2013 John Wiley & Sons, Ltd.     

Error estimates for the numerical approximation of a quaslinear Neumann problem under minimal regularity of the data

The finite element based approximation of a quasilinear elliptic equation of non monotone type with Neumann boundary conditions is studied. Minimal regularity assumptions on the data are imposed. The consideration is restricted to polygonal domains of dimension two and polyhedral domains of dimension three. Finite elements of degree k ≥ 1 are used to approximate the equation. Error estimates are established in the L ²(Ω) and H ¹(Ω) norms for convex and non-convex domains. The issue of uniqueness of a solution to the approximate discrete equation is also addressed.     

Asymptotically almost periodic solutions for abstract neutral integro-differential equations

We study the existence of asymptotically almost periodic classical solutions for a class of abstract neutral integro-differential equation with unbounded delay. A concrete application to partial neutral integro-differential equations which arise in the study of heat conduction in fading memory material is considered.     

Smoluchowski’s equation: Rate of convergence of the Marcus-Lushnikov process

We derive a satisfying rate of convergence of the Marcus-Lushnikov process towards the solution to Smoluchowski’s coagulation equation. Our result applies to a class of homogeneous-like coagulation kernels with homogeneity degree ranging in (−∞,1]. It relies on the use of a Wasserstein-type distance, which has shown to be particularly well-adapted to coalescence phenomena. It was introduced and used in preceding works (Fournier and Laurençot (2006) [7]) and (Fournier and Löcherbach (2009) [8]).     

Hormonal therapy in the senescence: Prostatic microenvironment structure and adhesion molecules

Hormonal replacement has been utilized to minimize the harmful effects of hormonal imbalance in elderly men. The development and progression of prostatic diseases and their relation to hormone therapy is still unclear. Thus, the aim herewith was to characterize the structure and dystroglycan molecule (DGs) reactivities in the ventral prostatic lobe from elderly rats submitted to steroid hormone replacement. Male rats (Sprague-Dawley) were divided into one Young group and six senile groups. The Young group (YNG) (4 months old) received peanut oil (5mL/kg, s.c.). The senile rats (10 months old) were submitted to the following treatments: Senile group (SEN) (5mL/kg peanut oil, s.c.); Testosterone group (TEST) (5mg/kg testosterone cipionate, s.c.); Estrogen group (EST) (25μg/kg 17β-estradiol, s.c.); Castrated group (CAS) (surgical castration); Castrated-Testosterone (CT) (surgical castration and treatment similar to TEST group); and Castrated-Estrogen (CE) (surgical castration and treatment similar to EST group). After 30 days treatment, blood samples were collected for hormonal analysis and ventral prostate samples were processed for light and transmission electron microscopies, morphometrical analysis, immunohistochemistry and Western Blotting. The results showed decreased serum testosterone levels in the senescence and increased testosterone and estrogen plasmatic levels after hormone administration in the TEST and EST groups, respectively, highlighting the therapy efficiency. Hypertrophied stroma and inflammatory cells were verified in the SEN group. After hormone replacement in the senescence or following castration, atrophic epithelium, epithelial cells with clear cytoplasmic halo around the nucleus, microacini and maintenance of hypertrophied stroma were seen. Decreased DG levels were verified in the senescence. After hormonal therapy, increased protein levels of these molecules were observed, especially in those groups which received estradiol. Thus, the occurrence of inflammatory cells, stromal hypertrophy and the presence of cells with clear halo around the nucleus after hormonal therapy probably indicated prostatic paracrine signaling imbalance, suggesting a stromal reactive microenvironment favorable to the development of glandular lesions. However, the increase of DG levels characterized positive effect of steroid hormone replacement on the prostate in the senescence. Thus, it could be concluded that despite having positive effects on important molecules involved in the maintenance of epithelial-stromal interaction and glandular cytoarchitecture, such as DGs, hormonal therapy enhanced structural changes associated with senescence, probably due to increased hormonal imbalance between androgens and estrogens in the prostatic tissue.     

A DFT/TDDFT study of porphyrazines and phthalocyanine oxo‐titanium derivatives as potential dyes in solar cells

Density functional theory and time dependent density functional theory calculations at the level of LDA/BP86/TZ2P were performed systematically on several Ti(IV) complexes of porphyrazines and one phthalocyanine. We performed an analysis of the frontier molecular orbitals of the ground state electronic structures and also discuss in particular the good concordance of our results with the experimental data, which affords to predict the geometrical and optical properties of new complexes ( 3 , 4 , and 7 ). We also emphasize the characterization of the UV–vis absorption spectra and propose transitions that contribute to the Q and B bands. Some useful calculated properties in complexes 2 , 3 , and 7 , like: high light absorption in the visible region of the spectra, transitions involved in these bands with a determined direction, charge separation, bigger highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO‐LUMO) gaps than complexes 4 and 5 , and the energy of their LUMO orbitals (that are higher than the lowest energy level of the conduction band of the TiO₂) indicate that system complexes 2 , 3 , and 7 could act as light‐harvesting sensitizers for dye‐sensitized solar cells (DSCs). These proposals were made using a model of the previously experimentally known phthalocyanine, which was used as sensitizer in DSCs devices, comparing its electronic properties with the herein proposed sensitizers. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011     

A new optimization strategy for gaseous phase sampling by an internally cooled solid-phase microextraction technique

This study describes a new optimization strategy for internally cooled solid-phase microextraction based on a multivariate approach. The coating temperature was changed in an extraction while manipulating the extraction times to improve the extraction of compounds with different volatilities. Polycyclic aromatic hydrocarbons (PAHs) and phthalic acid esters (PEs) and adipate were used as model compounds in this study. The optimization strategy was in two steps: (1) multivariate optimization of extraction time and initial coating temperature and (2) multivariate optimization of total extraction time and the time required to cool the coating to a lower temperature as determined in step 1. The observed analytical response in relation to the coating temperature was found to be dependent on the analyte volatility and size. The optimized extraction condition for PEs was 23 min extraction while maintaining the coating at 140°C, followed by 7 min of cooling the coating at 10°C. For the PAHs the coating temperature was maintained at 60°C for the first 20 min and at 5°C in the last 20 min of extraction. Comparisons have been made between the proposed optimized conditions with the conventional internally cooled fiber approach and the results thoroughly discussed. The proposed optimization strategy was found to be more effective for all the analytes, especially for the semi-volatiles, compared to the conventional method.     

Assessing the effect of oxygen and microbial inhibitors to optimize ferricyanide-mediated BOD assay

Methods for short-term BOD analysis (BOD_st) based on ferricyanide mediator reduction have succeeded in overcoming some problems associated with the standard BOD test analysis (BOD₅) such as long-term incubations (5 days), the need to dilute samples and low reproducibility. Here we present a bioassay where a Klebsiella pneumoniae environmental strain successfully reduces ferricyanide without de-aeration of the samples with linear BOD₅ ranges between 30 and 500 mg L⁻¹ or 30 and 200 mg L⁻¹, using glucose-glutamic acid solution (GGA) or OECD standards respectively. We further propose a new assay termination solution that allows higher reproducibility and standardization of the cell-based assay, employing formaldehyde (22.7 g L⁻¹) or other compounds in order to stop ferricyanide reduction without affecting the amperometric detection and therefore replace the centrifugation step normally used to stop microbial-driven reactions in ferricyanide-mediated bioassays. These improvements led to an accurate determination of real municipal wastewater samples.