Cytotoxicity and genotoxicity of light emitted by incandescent, halogen, and LED bulbs on ARPE-19 and BEAS-2B cell lines

LED technology has the extraordinary ability to reduce energy consumption, constituting an economic and ecological advantage, so it is planned to replace incandescent, halogen and other inefficient bulbs for public and domestic lighting with LEDs. LEDs present specific spectral and energetic characteristics compared with those of other domestic light sources, so the potential risks for human health of these bulbs need to be explored. The aim of this study was to assess cytotoxicity and genotoxicity of light emitted by different commercial light bulbs: incandescent, halogen, and two LED bulbs with different correlated color temperatures. The evaluation was done on ARPE-19 as a specific cell model for eye toxicity and on BEAS-2B as a good cell model for toxicology tests. Light induced mainly cytotoxic effects on ARPE-19 and DNA damage on BEAS-2B, so different cell lines showed different biological responses. Moreover, our findings indicate that among the four bulbs, cold LED caused the highest cytotoxic effect on ARPE-19 and the highest genotoxic and oxidative effect on BEAS-2B. Cold LED is probably able to cause more cellular damage because it contains more high-energy radiations (blue). These results suggest that LED technology could be a safe alternative to older technologies, but the use of warm LED should be preferred to cold LED, which can potentially cause adverse effects on retinal cells

Interplay between steric and electronic factors in determining the strength of intramolecular resonance-assisted NH...O hydrogen bond in a series of [beta]-ketoarylhydrazones

Publisher's version/PDFThe crystal structures of six [beta]-ketoarylhydrazones are reported: 1,(Z)-2-(2-bromophenylhydrazono)-3-oxobutanenitrile; 2, (Z)-2-(2-methylphenylhydrazono)-3-oxobutanenitrile; 3, (E)-methyl-2-(2-methoxyphenylhydrazono)-3-oxobutanoate; 4, E, methyl-2-(2-cyanophenylhydrazono)-3-oxobutanoate; 5, (Z)-methyl-2-(4-cyanophenylhydrazono)-3-oxobutanoate; 6, pentane-2,3,4-trione-3-(2-carboxyphenylhydrazone). All of them form intramolecular hydrogen bonds assisted by resonance (RAHB), with N...O distances in the range 2.541(5)-2.615(3) [Angstrom]. These hydrogen bonds are differently aff ected by the substituents at the heterodienic fragment, being strengthened by electronwithdrawing substituents in position 2 (more by 2-COMe than 2-CN substitution), and weakened in [beta]-esterhydrazones and when the N-H forms a bifurcated hydrogen bond. The role played by the different steric and electronic properties of the substituents in strengthening the H-bond is investigated, besides X-ray crystallography, by IR and [superscript 1]H NMR characterization of the NH proton, and quantum mechanical DFT calculations at the B3LYP/6-31 + G(d,p) level of theory on test molecules

Interplay of hydrogen bonding and other molecular interactions in determining the crystal packing of a series of anti-[beta]-ketoarylhydrazones

Publisher's version/PDFThe crystal structures of six anti-[beta]-ketoarylhydrazones are reported: (a1) (E)-2-(4-cyanophenylhydrazono)-3- oxobutanenitrile; (a2) (E)-2-(4-methylphenylhydrazono)-3-oxobutanenitrile; (a3) (E)-2-(4-acetylphenylhydrazono)-3-oxobutanenitrile; (a4) (E)-2-(2-methoxyphenylhydrazono)-3-oxobutanenitrile; (a5) (E)-2-(2-acetylphenylhydrazono)-3-oxobutanenitrile; (a6) (E)-2-(2-nitrophenylhydrazono)-3-oxobutanenitrile. All compounds contain the [pi]-conjugated heterodienic group HN--N==C--C==O and could form, at least in principle, chains of intermolecular N--H...O hydrogen bonds assisted by resonance (RAHB-inter). Compounds (a1) and (a2) form this kind of hydrogen bond though with rather long N...O distances of 2.948 (3) and 2.980 (2) [Angstrom], and compound (a6) undergoes the same interaction but even more weakened [N...O 3.150 (1) [Angstrom]] by the intramolecular bifurcation of the hydrogen bond donated by the N--H group. The intrinsic weakness of the intermolecular RAHB makes possible the setting up of alternative packing arrangements that are controlled by an antiparallel dipole-dipole (DD) interaction between two C==O groups of the [beta]-ketohydrazone moiety [compounds (a4) and (a5)]. The critical factors that cause the switching between the different packings turn out to be the presence of hydrogen bonding accepting substituents on the phenyl and, most frequently, the intramolecular N--H...O bond with the O atom of the phenyl o-substituent. The crystal packing is widely determined by RAHB-inter (three cases) or DD (two cases) interactions. Only compound (a3) displays a different packing arrangement, where the DD interaction is complemented by a non-resonant hydrogen bond between a p-acetyl phenyl substituent and the hydrazone N--H group [N...O 2.907 (2) [Angstrom]]. Crystal densities range from 1.24 to 1.44 Mg m[superscript -3] and are shown to increase with the number of intermolecular hydrogen bonds and other non-van der Waals interactions

Learning from Nature: Pregnancy Changes the Expression of Inflammation-Related Genes in Patients with Multiple Sclerosis

Pregnancy is associated with reduced activity of multiple sclerosis (MS). However, the biological mechanisms underlying this pregnancy-related decrease in disease activity are poorly understood

On the Evolution of the Star Formation Rate Function of Massive Galaxies. Constraints at 0.4<z<1.8 from the GOODS-MUSIC Catalogue

[abridged] We study the evolution of the Star Formation Rate Function (SFRF) of massive galaxies over the 0.4<z<1.8 redshift range and its implications for our understanding of the physical processes responsible for galaxy evolution. We use multiwavelength observations included in the GOODS-MUSIC catalogue, which provides a suitable coverage of the spectral region from 0.3 to 24 micron and either spectroscopic or photometric redshifts for each object. Individual SFRs have been obtained by combining UV and 24 micron observations, when the latter were available. For all other sources an "SED fitting" SFR estimate has been considered. We then define a stellar mass limited sample, complete in the Mstar>1.e10 Msun range and determine the SFRF using the 1/Vmax algorithm. We define simulated galaxy catalogues based on three different semi-analytical models of galaxy formation and evolution. We show that the theoretical SFRFs are well described by a double power law functional form and its redshift evolution is approximated with high accuracy by a pure evolution of the typical SFR. We find good agreement between model predictions and the high-SFR end of the SFRF, when the observational errors on the SFR are taken into account. However, the observational SFRF is characterised by a double peaked structure, which is absent in its theoretical counterparts. At z>1.0 the observed SFRF shows a relevant density evolution, which is not reproduced by SAMs, due to the well known overprediction of intermediate mass galaxies at z~2. The agreement at the low-SFR end is poor: all models overpredict the space density of SFR~1 Msun/yr and no model reproduces the double peaked shape of the observational SFRF. If confirmed by deeper IR observations, this discrepancy will provide a key constraint on theoretical modelling of star formation and stellar feedback.Comment: 12 pages, 4 figures and 3 table. Accepted for publication by MNRAS - updated reference

Peripheral blood biomarkers in multiple sclerosis.

Multiple sclerosis is the most common autoimmune disorder affecting the central nervous system. The heteroge-neity of pathophysiological processes in MS contributes to the highly variable course of the disease and unpre-dictable response to therapies. The major focus of the research on MS is the identification of biomarkers inbiologicalfluids, such as cerebrospinalfluid or blood, to guide patient management reliably. Because of the diffi-culties in obtaining spinalfluid samples and the necessity for lumbar puncture to make a diagnosis has reduced,the research of blood-based biomarkers may provide increasingly important tools for clinical practice. However,currently there are no clearly established MS blood-based biomarkers. The availability of reliable biomarkerscould radically alter the management of MS at critical phases of the disease spectrum, allowing for interventionstrategies that may prevent evolution to long-term neurological disability. This article provides an overview ofthis researchfield and focuses on recent advances in blood-based biomarker researc

Enabling planetary science across light-years. Ariel Definition Study Report

Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, was adopted as the fourth medium-class mission in ESA's Cosmic Vision programme to be launched in 2029. During its 4-year mission, Ariel will study what exoplanets are made of, how they formed and how they evolve, by surveying a diverse sample of about 1000 extrasolar planets, simultaneously in visible and infrared wavelengths. It is the first mission dedicated to measuring the chemical composition and thermal structures of hundreds of transiting exoplanets, enabling planetary science far beyond the boundaries of the Solar System. The payload consists of an off-axis Cassegrain telescope (primary mirror 1100 mm x 730 mm ellipse) and two separate instruments (FGS and AIRS) covering simultaneously 0.5-7.8 micron spectral range. The satellite is best placed into an L2 orbit to maximise the thermal stability and the field of regard. The payload module is passively cooled via a series of V-Groove radiators; the detectors for the AIRS are the only items that require active cooling via an active Ne JT cooler. The Ariel payload is developed by a consortium of more than 50 institutes from 16 ESA countries, which include the UK, France, Italy, Belgium, Poland, Spain, Austria, Denmark, Ireland, Portugal, Czech Republic, Hungary, the Netherlands, Sweden, Norway, Estonia, and a NASA contribution

Hydrogen-bonded cocrystals of the drug metformin: from molecular interactions analysis to supramolecular synthesis and characterization of Met-bis(DCA), a pharmaceutical cocrystal with enhanced anti-leukemic activity

Metformin (met) being a drug of first choice for oral therapy of type 2 diabetes, its anticancer activity is the subject of active research. Met can exist in three resonance-stabilized forms, i.e. as neutral molecule (Met), monoprotonated (MetH+) or diprotonated (MetH22+) cation, with dissociation constants in water typical of biguanides: pKa1~12.40; pKa2=2.96. As successful application, we report the crystal engineering, supramolecular synthesis, crystal structure determination and in vitro biological activity testing of two new PCCs of Met with the antileukemic drug dichloroacetic acid (DCA, pKa=0.9) in 1:1 (1, MetH+∙DCA-) and 1:2 (2, MetH2 2+∙2DCA-) ratio,respectively

Hydrogen Bond at the Dawn of the XXI Century. New Methods, New Results, New Ideas

Chapter 14 of the Proceedings of the NATO Advanced Research Workshop on Physical-Chemical Properties from Weak Interactions. Erice, Italy, 23-29 May 2001. / Though the hydrogen bond (H-bond) is known since 1920 and in spite of the extraordinary number of books and scientific papers dedicated to it, all attempts to predict its geometry and energetics from the simple knowledge of the chemical structure of the interacting molecules have been so far unsuccessful, a question we have sometimes indicated as the H-bond puzzle. A recent advance in the solution of this problem is represented by the Electrostatic-CovalentH-Bond Model (ECHBM) according to which (i) weak H-bonds are electrostatic in nature but become increasingly covalent with increasing strength, very strong bonds being essentially three-centre-four-electron covalent bonds; (ii) strong and very strong H-bonds may belong only to a limited number of classes which are three for X-H...X homonuclear and four for X-H...Y heteronuclear H-bonds; (iii) within each class, H-bonds are the stronger the smaller is DeltaPA, the difference between the proton affinities of the H-bond donor and acceptor atoms. It is shown that this model leads to an exhaustive classification of all H-bonds in chemical classes which, in turn, becomes a base for the prediction of H-bond strength starting from the chemical structures of the interacting molecules