Enhanced solar driven photocatalytic removal of antibiotics from aquaculture effluents by TiO2/carbon quantum dot composites

Aquaculture exploitation is associated with the consumption of antibiotics, such as sulfadiazine (SDZ), sulfamethoxazole (SMX) and trimethoprim (TMP), the latter two being also vastly used to treat bacterial infections in humans. Consequently, and given that aquaculture wastewater treatments are not actually designed for the removal of antibiotics, they are ubiquitous in aquaculture effluents, which sets the risk of bacterial resistance. To face the need for an efficient and sustainable treatment to remove these antibiotics from the referred effluents, carbon quantum dots (CQDs) were produced, incorporated into titanium dioxide (TiO2), and evaluated for solar driven photodegradation of SDZ, SMX and TMP. Eleven different materials were synthesized and tested for their photocatalytic activity in phosphate buffer solution (PBS) and synthetic sea salts (SSS), used as synthetic matrices to simulate fresh and brackish water, respectively. Upon selection of the most efficient photocatalyst for each antibiotic and matrix, kinetic results demonstrated that its use allowed for remarkable reductions of SDZ, SMX and TMP half-life times (t1/2) in both matrices (between 19 and 68 times). Therefore, the application of the here synthesized photocatalysts for the advanced treatment of aquaculture effluents is promising, allowing for a green solar driven removal of antibiotics.publishe

Physiological and genetic characterization of wheat lines sharply differing in sodium accumulation

Poster no. 129Improving nutrient use efficiency is an important objective in modern breeding programs. Our group attempts to elucidate the components that contribute to greater efficiencies of potassium (K) acquisition and utilization in wheat (Triticum aestivum), and its nexus with sodium (Na) dynamics.Instituto de Recursos BiológicosFil: Silva, Martha M. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Moriconi, Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Tecnológico Chascomús; Argentina. Universidad Nacional de San Martín; ArgentinaFil: Gualano, L.D. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Tecnológico Chascomús; Argentina. Universidad Nacional de San Martín; ArgentinaFil: Tranquilli, Gabriela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Santa-María, Guillermo E. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Tecnológico Chascomús; Argentina. Universidad Nacional de San Martín; Argentin

Micromorfologia foliar na análise da fitotoxidez por glyphosate em Eucalyptus grandis

Foram avaliados os efeitos da deriva de formulações comerciais de glyphosate sobre a superfície foliar e o crescimento de clones de eucalipto. Mudas de seis clones foram submetidas a 129,6 g ha-1 de glyphosate das formulações comerciais Scout®, Roundup NA®, Roundup transorb® e Zapp QI®. Entre os clones não foram identificadas diferenças quanto à tolerância ao glyphosate. Plantas expostas à deriva simulada de Roundup transorb® e Zapp QI® apresentaram, respectivamente, a maior e menor porcentagem de intoxicação. Observou-se menor massa seca em plantas expostas ao glyphosate, independentemente da formulação, e menor altura naquelas expostas ao Scout® e ao Roundup transorb®. As características quantitativas da superfície foliar não foram afetadas pelo glyphosate. As alterações micromorfológicas ocorreram na ausência de danos visíveis e foram observadas em ambas as faces da epiderme, em todos os clones avaliados. Danos como erosão e aspecto amorfo das ceras epicuticulares e infestação por hifas fúngicas ocorreram, independentemente da formulação utilizada. A avaliação anatômica da superfície foliar foi relevante para descrição e interpretação dos danos causados pelo glyphosate. Os dados de crescimento e de intoxicação indicam o Zapp QI® como a formulação de menor risco para a cultura do eucalipto quanto aos efeitos indesejáveis da deriva.The effects of commercial glyphosate drift on the leaf surface and growth of eucalypt clones were evaluated. Seedlings of six clones were submitted to 129.6 g ha-1 sub-rate of commercial glyphosate formulations Scout®, Roundup NA®, Roundup transorb® and Zapp QI®. No differences in tolerance to glyphosate were observed among the clones. Plants exposed to simulated drift of Roundup transorb® and Zapp QI® presented the highest and lowest intoxication percentages, respectively. Plants exposed to glyphosate reduced dry biomass, regardless of the formulation, and also reduced height of the plants exposed to Scout® and Roundup transorb®. Leaf surface characteristics were not affected by glyphosate application. However, the micromorphological damages occurred prior to the appearance of visible symptoms, and were observed on both faces of the epidermis, in all clones tested. Damages such as erosion and amorphous aspect of epicuticular waxes and infestation of fungal hyphae occurred, independently of the formulation used. The anatomical evaluation of the leaf surface effectively described the damages caused by glyphosate. The growth and intoxication data indicate Zapp QI® formulation as presenting the lowest risk to eucalypt culture, in relation to the undesirable herbicide drift effects

Can invasions occur without change? A comparison of G-matrices and selection in the peach-potato aphid, Myzus persicae

Most evolutionary research on biological invasions has focused on changes seen between the native and invaded range for a particular species. However, it is likely that species that live in human-modified habitats in their native range might have evolved specific adaptations to those environments, which increase the likelihood of establishment and spread in similar human-altered environments. From a quantitative genetic perspective, this hypothesis suggests that both native and introduced populations should reside at or near the same adaptive peak. Therefore, we should observe no overall changes in the G (genetic variance–covariance) matrices between native and introduced ranges, and stabilizing selection on fitness-related traits in all populations. We tested these predictions comparing three populations of the worldwide pest Myzus persicae from the Middle East (native range) and the UK and Chile (separately introduced ranges). In general, our results provide mixed support for this idea, but further comparisons of other species are needed. In particular, we found that there has been some limited evolution in the studied traits, with the Middle East population differing from the UK and Chilean populations. This was reflected in the structure of the G-matrices, in which Chile differed from both UK and Middle East populations. Furthermore, the amount of genetic variation was massively reduced in Chile in comparison with UK and Middle East populations. Finally, we found no detectable selection on any trait in the three populations, but clones from the introduced ranges started to reproduce later, were smaller, had smaller offspring, and had lower reproductive fitness than clones from the native range

Homogeneous Fermion Superfluid with Unequal Spin Populations

For decades, the conventional view is that an s-wave BCS superfluid can not support uniform spin polarization due to a gap $\Delta$ in the quasiparticle excitation spectrum. We show that this is an artifact of the dismissal of quasiparticle interactions $V_{qp}^{}$ in the conventional approach at the outset. Such interactions can cause triplet fluctuations in the ground state and hence non-zero spin polarization at "magnetic field" $h<\Delta$. The resulting ground state is a pairing state of quasiparticles on the ``BCS vacuum". For sufficiently large $V_{qp}$, the spin polarization of at unitarity has the simple form $m\propto \mu^{1/2}$. Our study is motivated by the recent experiments at Rice which found evidence of a homogenous superfluid state with uniform spin polarization.Comment: 4 pages, 3 figure

The role of structural evolution on the quantum conductance behavior of gold nanowires during stretching

Gold nanowires generated by mechanical stretching have been shown to adopt only three kinds of configurations where their atomic arrangements adjust such that either the [100], [111] or [110] zone axes lie parallel to the elongation direction. We have analyzed the relationship between structural rearrangements and electronic transport behavior during the elongation of Au nanowires for each of the three possibilities. We have used two independent experiments to tackle this problem, high resolution transmission high resolution electron microscopy to observe the atomic structure and a mechanically controlled break junction to measure the transport properties. We have estimated the conductance of nanowires using a theoretical method based on the extended H\"uckel theory that takes into account the atom species and their positions. Aided by these calculations, we have consistently connected both sets of experimental results and modeled the evolution process of gold nanowires whose conductance lies within the first and third conductance quanta. We have also presented evidence that carbon acts as a contaminant, lowering the conductance of one-atom-thick wires.Comment: 10 page

Dipolar repulsion in alpha-halocarbonyl compounds revisited

The concept of dipolar repulsion has been widely used to explain several phenomena in organic chemistry, including the conformational preferences of carbonyl compounds. This model, in which atoms and bonds are viewed as point charges and dipole moment vectors, respectively, is however oversimplified. To provide a causal model rooted in quantitative molecular orbital theory, we have analyzed the rotational isomerism of haloacetaldehydes OHC-CH2X (X = F, Cl, Br, I), using relativistic density functional theory. We have found that the overall trend in the rotational energy profiles is set by the combined effects of Pauli repulsion (introducing a barrier around gauche that separates minima at syn and anti), orbital interactions (which can pull the anti minimum towards anticlinal to maximize hyperconjugation), and electrostatic interactions. Only for X = F, not for X = Cl-I, electrostatic interactions push the preference from syn to anti. Our bonding analyses show how this trend is related to the compact nature of F versus the more diffuse nature of the heavier halogens.Theoretical Chemistr

Gene-based Interventions for Cancer Immunotherapy

Immunotherapy of cancer has deservedly gained much attention in the past few years and is likely to continue to advance and become a fundamental cancer treatment. While vaccines, chimeric antigen receptor (CAR) T cells and checkpoint blockade have received the lion’s share of the attention, an important direct role for gene transfer as an immunotherapy is emerging. For example, oncolytic viruses induce immunogenic cell death, thus liberating both antigens and the signals that are necessary for the activation of antigen-presenting cells, ensuring stimulation of an adaptive response. In another example, transfer of prodrug converting enzymes, such as the herpes simplex virus-thymidine kinase (HSV-tk) gene or the cytosine deaminase gene, has been shown to promote an immune response, thus functioning as immunotherapies. Alternatively, our own work involves the use of nonreplicating viral vectors for the simultaneous delivery of gene combinations that promote both cell death and an immune response. In fact, our gene transfer approach has been applied as a vaccine, immunotherapy or in situ gene therapy, resulting in immunogenic cell death and the induction of a protective immune response. Here, we highlight the development of these approaches both in terms of technical advances and clinical experience