Characterization of Hemoglobin Adducts of 1,3-Dinitrobenzene and 1,3,5-Trinitrobenzene

1,3-dinitrobenzene (DNB) and 1,3,5-trinitrobenzene (TNB) are used primarily in explosive compositions and munitions and have been detected as environmental contaminants of surface waters as well as ground waters near production waste disposal sites. Hemoglobin (Hb) adducts have recently been proposed as biological markers of exposure assessment for various environmental compounds, including nitroaromatics. In the present study, we have investigated the formation of DNB and TNB hemoglobin adducts in vivo and in vitro in the blood of shrew (Cryptotis parva). DNB and TNB hemoglobin adducts were detected by GC/MS after either basic (0.1N NaOH) or acid (2N HCl) hydrolysis followed by organic solvent extraction and derivatization of the corresponding amines. The levels of DNB-Hb adducts detected after basic hydrolysis (238.7 ± 50.2 pg/mg Hb) are higher than the corresponding levels detected after acid hydrolysis (52.5 ± 16.2 pg/mg Hb). For the TNB-Hb the levels after acid hydrolysis (132.2 ± 37.8 pg/mg Hb) are higher than the levels detected after basic hydrolysis (44.7 ± 15.3 pg/mg Hb.) These results demonstrate the effectiveness of the hemoglobin adduct model for monitoring exposure to nitroaromatics.     

Defensive Compounds and Male-Produced Sex Pheromone of the Stink Bug, Agroecus griseus

Agroecus griseus is a serious corn pest in Brazil. Contents of the dorsal abdominal glands (DAGs) in nymphs, and the metathoracic gland (MTG) in adults of this species were characterized and quantified. Compounds found were similar to those of other Pentatomidae species and included aliphatic hydrocarbons, aldehydes, oxo-alkenals, and esters. However, two compounds were found in the MTG that have not been described previously for this family. Mass spectrometry, infrared spectroscopy, and gas chromatographic analysis using coinjection with authentic standards confirmed the identities of the compounds as enantiopure (S)-2-methylbutyl acetate and 3-methyl-2-butenyl acetate. The five nymphal instars showed significantly different ratios of components, mainly between those of the first and later instars. No significant differences were detected in MTG contents between sexes. Gas chromatography (GC) analysis of aeration extracts of males and females showed the presence of a compound released exclusively by males. Gas chromatography – electroantennographic detection (GC-EAD) assays indicated that the male-specific compound is bioactive in females, suggesting the presence of an attractant pheromone. The mass spectrum and infrared data for this compound matched with methyl 2,6,10-trimethyltridecanoate, a sex pheromone component previously detected in the stink bugs, Euschistus heros and E. obscurus. The synthetic standard coeluted with the natural pheromone on two different GC stationary phases, confirming the proposed structure. Y-tube olfactometer assays showed that the synthetic standard was strongly attractive to females, and GC-EAD tests produced responses with antennae from females similar to those of the natural pheromone.     

About Piero Matematico (CD)

Daniela Gentilin and Ennio Bettanello reflect on the realization of their project for the CD Piero Matematico.     

Phase transformation and microstructural evolution after heat treatment of a terbium-doped lithium–aluminum phosphate glass

The crystallization kinetics and phase transformation of a transparent Tb³⁺-doped lithium–aluminum phosphate glass, prepared by melt quenching, were investigated. The energy associated to the glass transition and the crystallization parameters (activation energy for crystallization and Avrami exponent) were evaluated by different methods using the experimental data obtained by differential thermal analysis performed at different heating rates. Using an isoconversional method to determine the change of the activation energy for crystallization with the fraction of crystallization, it was verified that with the increase in the fraction of crystallization from 0.1 to 0.9, the value of the activation energy decreased slightly from ~370 to ~310 kJ mol^?1 and that the Avrami exponent varied from 0.8 to 1, suggesting a surface crystal growth mechanism. Observation of the microstructural evolution of heat-treated glass samples confirmed a surface crystallization process revealing spherulitic crystals constituted mainly by aluminum metaphosphate.     

Base Isolation by a Soft First Story with Inclined Columns

An idea of passive base isolation of buildings is explored, using inclined rubber base isolators or inclined “soft” first-story columns. Such a system behaves as a physical pendulum, “pivoted” above center of mass, and is more stable than the standard system. Another advantage of the inclination is that the inertia forces of the structure due to rotation about the pivot point cancel to some degree the inertia forces due to the base translation. This is expected to result in smaller relative deformations of the building and smaller internal forces. In this paper, the consequences of this concept are illustrated on a simple model (base isolated single-degree-of-freedom oscillator), but also considering the soil flexibility and the wave nature of strong earthquake shaking (these are associated with additional rotations of the system and also affect the system period). A frequency domain solution is presented for small deformations, rigid foundations embedded in a homogeneous elastic half-space, and horizontal in-plane and Rayleigh wave foundation driving motion.     

The fate of Transparent Exopolymer Particles (TEP) in integrated membrane systems: Removal through pre-treatment processes and deposition on reverse osmosis membranes

The abundance of Transparent Exopolymer Particles (TEP) in surface waters has been unnoticed for many years until recently as a potential foulant in reverse osmosis systems. Recent studies indicate that TEP may cause organic and biological fouling and may enhance particulate/colloidal fouling in reverse osmosis membranes. The presence of TEP was measured in the raw water, the pre-treatment processes and reverse osmosis (RO) systems of 6 integrated membrane installations. A spectrophotometric method was used to measure TEP in the particulate size range (>0.40 μm) and was extended to measure TEP in the colloidal size range (0.05–0.40 μm). Ultrafiltration pre-treatment applied in 4 plants, totally removed particulate TEP while microfiltration systems (2 plants) and coagulation/sedimentation/rapid sand filtration systems (3 plants) partially removed this fraction. None of the pre-treatment systems investigated totally removed colloidal TEP. Biopolymer analysis using LC–OCD showed consistency between colloidal TEP and polysaccharide removal by UF pre-treatment and further verified the presence of TEP in the RO feedwater. TEP deposition in the RO system was determined after measuring total TEP concentrations in the RO feed and concentrate. The TEP deposition factors and specific deposition rates indicate that TEP accumulation had occurred in all plants investigated. This observation was verified by an autopsy of RO modules from two RO plants. Further improvement and verification of the (modified) TEP method, in particular the calibration, is necessary so that it can be employed to investigate the role of TEP in the fouling of RO systems.     

Energy management in metro-transit systems: An innovative proposal toward an integrated and sustainable urban mobility system including plug-in electric vehicles

The energy consumptions growth, the upward interest for environmental sustainability and the technological evolution carry to the necessity to review the planning criteria of urban mobility systems in large cities and metropolitan areas. With this aim, new studies and projects are in progress, especially dealing with the power systems for metro-transit lines and surface electric vehicles. In this framework, the authors perform a study that, from an overview about the main energy management issues connected to the city transport, provides an innovative proposal for the design of sustainable urban mobility system: the integration of the metro-lines with surface plug-in electric vehicles. The present paper includes the energy analysis results, obtained by an application on a real case study of an home-made simulation software, describes the proposal in terms of power systems architecture and business models, pointing out the potential advantages that its implementation could give in terms of energy saving, environmental sustainability and reduced economic impact, as a result of the maximum exploitation of existing electric power plant.     

Evaluating mechanical properties and degradation of YTZP dental implants

Lately new biomedical grade yttria stabilized zirconia (YTZP) dental implants have appeared in the implantology market. This material has better aesthetical properties than conventional titanium used for implants but long term behaviour of these new implants is not yet well known. The aim of this paper is to quantify the mechanical response of YTZP dental implants previously degraded under different time conditions and compare the toughness and fatigue strength with titanium implants. Mechanical response has been studied by means of mechanical testing following the ISO 14801 for Standards for dental implants and by finite element analysis. Accelerated hydrothermal degradation has been achieved by means of water vapour and studied by X-ray diffraction and nanoindentation tests. The results show that the degradation suffered by YTZP dental implants will not have a significant effect on the mechanical behaviour. Otherwise the fracture toughness of YTZP ceramics is still insufficient in certain implantation conditions.