11 research outputs found
Comparative Study of the Oxidative Degradation of Different 4-Aminobenzene Sulfonamides in Aqueous Solution by Sulfite Activation in the Presence of Fe(0), Fe(II), Fe(III) or Fe(VI)
This study is focused on advanced oxidation technologies (AOTs) using the combined
effect of Fe(0âVI)/sulfite systems, that produce mainly SO4 radicals, to remove di erent
4-aminobenzene sulfonamides (SAs), namely sulfamethazine, sulfadiazine, sulfamethizole, from
aqueous solutions. Results obtained showed that neither sulfite nor iron alone is able to degrade
SAs; however, the combined effect depends on the oxidation state of iron species whose effectiveness
to activate sulfite to promote the degradation of SAs increased following this order: Fe(III) < Fe(II)
< Fe(0) < Fe(VI). Using Fe(VI)/sulfite, the complete removal of SAs was obtained in 5 min largely
surpassing the effectiveness of the other three systems. The sulfonamidesâ removal percentage was
markedly influenced by sulfite concentration and dissolved oxygen, which improved the generation
of oxidant radicals. Response surface methodology was applied, and a quadratic polynomial model
was obtained, which allowed us to determine the percentage of SAs degradation as a function of
both the iron species and sulfite concentrations. The study of the influence of the water matrix on
these AOTs revealed an inhibition of SAsâ removal percentage when using ground water. This is
probably due to the presence of different anions, such as HCO3
-, Cl-, and SO4
2- in relatively high
concentrations. According to the byproducts identified, the proposed degradation pathways include
hydroxylation, SO2 extrusion, and different bond-cleavage processes. Cytotoxicity of degradation
byproducts, using MTS assay with HEK 293 and J774 cell lines for the first time, did not show an
inhibition in cell proliferation, sustaining the safety of the process.This research was funded by both Ministry of Science and Innovation of Spain, grant number
CTQ2016-80978-C2-1-R, and CONACyT (Mexico), grant number 407494
Zero-Field SMM Behavior Triggered by Magnetic Exchange Interactions and a Collinear Arrangement of Local Anisotropy Axes in a Linear Co3 II Complex
A new linear trinuclear Co(II)3 complex with a formula of [{Co(ÎŒ-L)}2Co] has been prepared by self-assembly of Co(II) ions and the N3O3-tripodal Schiff base ligand H3L, which is obtained from the condensation of 1,1,1-tris(aminomethyl)ethane and salicylaldehyde. Single X-ray diffraction shows that this compound is centrosymmetric with triple-phenolate bridging groups connecting neighboring Co(II) ions, leading to a paddle-wheel-like structure with a pseudo-C3 axis lying in the CoâCoâCo direction. The Co(II) ions at both ends of the Co(II)3 molecule exhibit distorted trigonal prismatic CoN3O3 geometry, whereas the Co(II) at the middle presents an elongated trigonal antiprismatic CoO6 geometry. The combined analysis of the magnetic data and theoretical calculations reveal strong easy-axis agnetic anisotropy for both types of Co(II) ions (|D| values higher than 115 cmâ1) with the local anisotropic axes lying on the pseudo-C3 axis of the molecule. The magnetic exchange interaction between the middle and ends Co(II) ions, extracted by using either a Hamiltonian accounting for the isotropic magnetic coupling and ZFS or the Linesâ model, was found to be medium to strong and antiferromagnetic in nature, whereas the interaction between the external Co(II) ions is weak antiferromagnetic. Interestingly, the compound exhibits slow relaxation of magnetization and open hysteresis at zero field and therefore SMM behavior. The significant magnetic exchange coupling found for [{Co(ÎŒ-L)}2Co] is mainly responsible for the quenching of QTM, which combined with the easy-axis local anisotropy of the CoII ions and the ollinearity of their local anisotropy axes with the pseudo-C3 axis favors the observation of SMM behavior at zero field
Enantiopure Double ortho-Oligophenylethynylene-Based Helical Structures with Circularly Polarized Luminescence Activity
We thank the Ministerio de Economia y Competitividad (CTQ2017-85454-C2-1-P and CTQ2017-85454-C2-2-P), Ministerio de Ciencia e Innovacion (PID2020-113059GB-C21 and PID2020-113059GB-C22) and Junta de Andalucia (P20.00162) (Spain) for funding and P.R. and A. O. G. also for FPU contracts. Funding for open access charge is acknowledged to Universidad de Granada / CBUA.We also thank Big&Open Data Innovation Laboratory (BODaI-Lab), University of Brescia, granted by Fondazione Cariplo and Regione Lombardia, for access to resources of Computing Center CINECA (Bologna), Italy. Support from the Italian MIUR (Grant No. 2017A4XRCA) is also acknowledged.In this paper, we describe the optical and chiroptical properties
of an enantiopure multipodal ortho-oligophenylethynylene
(S,S,S,S)-1 presenting four chiral sulfoxide groups at the
extremes. The presence of these groups together with alkynes
allows the coordination with carbophilic Ag(I), and/or oxophilic
Zn(II) cations, yielding double helical structures in an enantiopure
way. In this sense, different behaviors in absorption,
fluorescence, ECD and CPL spectra have been found depending
on the stoichiometry and nature of the metal. We have
observed that Zn(II) coordination favors an intensity increase of
the electronic circular dichroism (ECD) spectra of compound
(S,S,S,S)-1 yielding an M-helicity in the ortho-oligophenylene
ethynylene (o-OPE) backbone. On the other hand, ECD spectra
of final Ag(I) complex shows two different bands with an
opposite sign to the free ligand, thus giving the P-helical
isomer. In addition, circularly polarized luminescence (CPL)
exhibit an enhanced intensity and negative sign in both
complexes. Computational studies were also carried out,
supporting the experimental results.Spanish Government CTQ2017-85454-C2-1-P
CTQ2017-85454-C2-2-PInstituto de Salud Carlos III
Spanish Government
European Commission PID2020-113059GB-C21
PID2020-113059GB-C22Junta de Andalucia
European Commission P20.00162University of Brescia / CBUAFondazione CariploMinistry of Education, Universities and Research (MIUR) 2017A4XRCARegione Lombardi
Fast Adapting Ensemble: A New Algorithm for Mining Data Streams with Concept Drift
The treatment of large data streams in the presence of concept drifts is one of the main challenges in the field of data mining, particularly when the algorithms have to deal with concepts that disappear and then reappear. This paper presents a new algorithm, called Fast Adapting Ensemble (FAE), which adapts very quickly to both abrupt and gradual concept drifts, and has been specifically designed to deal with recurring concepts. FAE processes the learning examples in blocks of the same size, but it does not have to wait for the batch to be complete in order to adapt its base classification mechanism. FAE incorporates a drift detector to improve the handling of abrupt concept drifts and stores a set of inactive classifiers that represent old concepts, which are activated very quickly when these concepts reappear. We compare our new algorithm with various well-known learning algorithms, taking into account, common benchmark datasets. The experiments show promising results from the proposed algorithm (regarding accuracy and runtime), handling different types of concept drifts
Cell Survival Enabled by Leakage of a Labile Metabolic Intermediate
Many metabolites are generated in one step of a biochemical pathway and consumed in a subsequent step. Such
metabolic intermediates are often reactive molecules which, if allowed to freely diffuse in the intracellular milieu,
could lead to undesirable side reactions and even become toxic to the cell. Therefore, metabolic intermediates
are often protected as protein-bound species and directly transferred between enzyme active sites in multi-function al enzymes, multi-enzyme complexes, and metabolons. Sequestration of reactive metabolic intermediates thus con tributes to metabolic efficiency. It is not known, however, whether this evolutionary adaptation can be relaxed in
response to challenges to organismal survival. Here, we report evolutionary repair experiments on Escherichia coli
cells in which an enzyme crucial for the biosynthesis of proline has been deleted. The deletion makes cells unable
to grow in a culture medium lacking proline. Remarkably, however, cell growth is efficiently restored by many single
mutations (12 at least) in the gene of glutamine synthetase. The mutations cause the leakage to the intracellular
milieu of a highly reactive phosphorylated intermediate common to the biosynthetic pathways of glutamine and pro line. This intermediate is generally assumed to exist only as a protein-bound species. Nevertheless, its diffusion upon
mutation-induced leakage enables a new route to proline biosynthesis. Our results support that leakage of seques tered metabolic intermediates can readily occur and contribute to organismal adaptation in some scenarios.
Enhanced availability of reactive molecules may enable the generation of new biochemical pathways and the poten tial of mutation-induced leakage in metabolic engineering is notedHuman Frontier Science Program RGP0041/2017Spanish Government RTI2018-097142-B-100Ministry of Science and Innovation, Spain (MICINN) 80NSSC18K1277European CommissionJunta de AndaluciaRegional Andalusian Government E-BIO-464-UGR-20
2020_DOC_0054
Effect of Heat Stress on Sperm DNA: Protamine Assessment in Ram Spermatozoa and Testicle
Sperm DNA fragmentation is considered one of the main causes of male infertility. The most accepted causes of sperm DNA damage are deleterious actions of reactive oxygen species (ROS), defects in protamination, and apoptosis. Ram sperm are highly prone to those damages due to the high susceptibility to ROS and to oxidative stress caused by heat stress. We aimed to evaluate the effects of heat stress on the chromatin of ejaculated and epididymal sperm and the activation of apoptotic pathways in different cell types in ram testis. We observed higher percentages of ejaculated sperm with increased chromatin fragmentation in the heat stress group; a fact that was unexpectedly not observed in epididymal sperm. Heat stress group presented a higher percentage of spermatozoa with DNA fragmentation and increased number of mRNA copies of transitional protein 1. Epididymal sperm presented greater gene expression of protamine 1 on the 30th day of the spermatic cycle; however, no differences in protamine protein levels were observed in ejaculated sperm and testis. Localization of proapoptotic protein BAX or BCL2 in testis was not different. In conclusion, testicular heat stress increases ram sperm DNA fragmentation without changes in protamination and apoptotic patterns
Tod@s deberĂamos ser feministas
El trabajo obtuvo un Premio TomĂĄs GarcĂa Verdejo a las buenas prĂĄcticas educativas en la Comunidad AutĂłnoma de Extremadura para el curso acadĂ©mico 2016/2017. Modalidad BSe describe un proyecto llevado a cabo en el IES Virgen de Soterraño de Barcarrota (Badajoz) que tenĂa como objetivo principal el fomento de la igualdad de gĂ©nero y que esta cuestiĂłn sirviese como punto de partida para erradicar la violencia de gĂ©nero. Otros objetivos de las actividades realizada dentro del poryecto eran: visibilizar el papel de la mujer en diferentes ĂĄmbitos de la sociedad, determinar las brechas de desigualdad y ser conscientes para combatirlas, conocer las formas de ejercer la violencia machista y trabajar mecanismos para prevenir y luchar contra ella, romper estereotipos a travĂ©s de la educaciĂłn e implicar a la comunidad educativa en la lucha por la igualdad entre hombres y mujeresExtremaduraES