Pruebas complementarias a la problemática del diagnóstico de la infección por los virus B y C en donantes de sangre

El objetivo de este trabajo es determinar si las transaminasas hepáticas tienen valor como pruebas complementarias que orienten el diagnóstico de hepatitis B y C, en donantes de sangre con anticuerpos positivos por el método ELISA a estas infecciones virales; teniendo en cuenta que las pruebas confirmatorias como el inmunoensayo recombinante (RIBA) o la prueba de ácidos nucleicos por técnicas moleculares como PCR (RNA HCV) para hepatitis C y DNA viral (PCR) para hepatitis B no se realizan aún en nuestro país debido a sus elevados costos. Se busca sumar esfuerzos en salud pública desde los bancos de sangre debido a la trascendencia de llegar a un diagnóstico en los donantes seropositivos, que hayan sido captados en el tamizaje, para prevenir la propagación de estas hepatitis. Se realizaron pruebas serológicas para hepatitis C, anticuerpos frente al antígeno del core de la hepatitis B y determinaciones de los niveles de GPT o ALT (Transaminasa Glutámica Pirúvica o Alanina Amino Transferasa), GOT o AST (Transaminasa Glutámico Oxalacética o Aspartato Amino Transferasa) en 236 donantes de sangre seropositivos para hepatitis B y C del Banco de Sangre del Hospital de Clínicas de la Universidad Nacional de Asunción-Paraguay. Las transaminasas elevadas fueron clasificadas de acuerdo a los marcadores serológicos positivos parahepatitis B y C, encontrándose niveles elevados en un 13.9% de individuos con anti-HBc, 40% en individuos con anti HCV y 2 de 7 casos en individuos con serología positiva para ambos marcadores serológicos. Casi la mitad de los donantes con marcador serológicopositivo para anti HCV presentan elevación de las transaminasas

Genetic diversity in Brazilian populations of Anastrepha obliqua (Macquart) based on mtDNA.

Anastrepha obliqua (Macquart), the West Indian fruit fly, is the second most polyphagous species within the genus in Brazil and therefore one of the most economically important pest species. It infests an extensive range of hosts, at least 60 species. Anastrepha obliqua ranges from northern Mexico to southern Brazil also including the Caribbean Islands. Methods: We sequenced a fragment of the mitochondrial gene COI to estimate population structure and genetic diversity of A. obliqua geographic collections in Brazil. Results: A total of 153 specimens from the Amazon Forest, Atlantic Rainforest, Cerrado, and Caatinga were analyzed. A total of 20 haplotypes were found. The highest diversity levels were observed in collections from the Amazon Forest. AMOVA and Fst tests showed evidence of genetic structure allowing us to delineate two groups of A. obliqua populations. The Mantel tests were not significant indicating a weak correlation between genetic and geographic distances. Mismatch distributions and Neutrality Tests suggest that the Caatinga, Cerrado and Atlantic Forest populations have experienced a recent population expansion. Conclusion: Populations in the Amazon Forest showed high genetic diversity when compared to the other biomes and the demographic parameters indicated a recent expansion of A. obliqua in Brazil

3D‐Architected Alkaline‐Earth Perovskites

3D ceramic architectures are captivating geometrical features with an immense demand in optics. In this work, an additive manufacturing (AM) approach for printing alkaline-earth perovskite 3D microarchitectures is developed. The approach enables custom-made photoresists suited for two-photon lithography, permitting the production of alkaline-earth perovskite (BaZrO 3, CaZrO 3, and SrZrO 3) 3D structures shaped in the form of octet-truss lattices, gyroids, or inspired architectures like sodalite zeolite, and C 60 buckyballs with micrometric and nanometric feature sizes. Alkaline-earth perovskite morphological, structural, and chemical characteristics are studied. The optical properties of such perovskite architectures are investigated using cathodoluminescence and wide-field photoluminescence emission to estimate the lifetime rate and defects in BaZrO 3, CaZrO 3, and SrZrO 3. From a broad perspective, this AM methodology facilitates the production of 3D-structured mixed oxides. These findings are the first steps toward dimensionally refined high-refractive-index ceramics for micro-optics and other terrains like (photo/electro)catalysis.</p

Temperature promotes selectivity during electrochemical CO₂ reduction on NiO:SnO₂ nanofibers

Electrolyzers operate over a range of temperatures; hence, it is crucial to design electrocatalysts that do not compromise the product distribution unless temperature can promote selectivity. This work reports a synthetic approach based on electrospinning to produce NiO:SnO2 nanofibers (NFs) for selectively reducing CO2 to formate above room temperature. The NFs comprise compact but disjoined NiO and SnO2 nanocrystals identified with STEM. The results are attributed to the segregation of NiO and SnO2 confirmed with XRD. The NFs are evaluated for the CO2 reduction reaction (CO2RR) over various temperatures (25, 30, 35, and 40 °C). The highest faradaic efficiencies to formate (FEHCOO−) are reached by NiO:SnO2 NFs containing 50% of NiO and 50% SnO2 (NiOSnO50NF), and 25% of NiO and 75% SnO2 (NiOSnO75NF), at an electroreduction temperature of 40 °C. At 40 °C, product distribution is assessed with in situ differential electrochemical mass spectrometry (DEMS), recognizing methane and other species, like formate, hydrogen, and carbon monoxide, identified in an electrochemical flow cell. XPS and EELS unveiled the FEHCOO− variations due to a synergistic effect between Ni and Sn. DFT-based calculations reveal the superior thermodynamic stability of Ni-containing SnO2 systems towards CO2RR over the pure oxide systems. Furthermore, computational surface Pourbaix diagrams showed that the presence of Ni as a surface dopant increases the reduction of the SnO2 surface and enables the production of formate. Our results highlight the synergy between NiO and SnO2, which can promote the electroreduction of CO2 at temperatures above room temperature.</p

Exceptional Larval Morphology of Nine Species of the Anastrepha mucronota Species Group (Diptera: Tephritidae)

Anastrepha is the most diverse and economically important genus of Tephritidae in the American tropics and subtropics. The striking morphology of the third instars of Anastrepha caballeroi Norrbom, Anastrepha crebra Stone, Anastrepha haplacantha Norrbom & Korytkowski, Anastrepha korytkowskii Norrbom, Anastrepha nolazcoae Norrbom & Korytkowski, and three newly discovered and as yet formally unnamed species (Anastrepha sp. Peru-82, Anastrepha sp. nr. protuberans, and Anastrepha sp. Sur-16), and the more typical morphology of Anastrepha aphelocentema Stone, are described using light and scanning electron microscopy. To contribute to a better understanding of the interspecific and intraspecific variation among species in the mucronota species group and facilitate phylogenetic studies, we integrate molecular and morphological techniques to confirm the identity and describe third instars. Larva-adult associations and the identification of described larvae were confirmed using DNA barcodes. We provide diagnostic characters to distinguish larvae among these nine species of the mucronota group and separate them from those of the 29 other Anastrepha species previously described. We introduce the vertical comb-like processes on the oral margin as a novel character, and the unusual character states, including position and shape of the preoral lobe, and dentate or fringed posterior margins of the oral ridges and accessory plates. Our comparative morphology concurs with most previously inferred phylogenetic relationships within the mucronota group

Behind the scenes: mechanisms regulating climatic patterns of dissolved organic carbon uptake in headwater streams

Large variability in dissolved organic carbon (DOC) uptake rates has been reported for headwater streams, but the causes of this variability are still not well understood. Here we assessed acetate uptake rates across 11 European streams comprising different ecoregions by using whole-reach pulse acetate additions. We evaluated the main climatic and biogeochemical drivers of acetate uptake during two seasonal periods. Our results show a minor influence of sampling periods but a strong effect of climate and dissolved organic matter (DOM) composition on acetate uptake. In particular, mean annual precipitation explained half of the variability of the acetate uptake velocities (VfAcetate) across streams. Temperate streams presented the lowest VfAcetate, together with humic-like DOM and the highest stream respiration rates. In contrast, higher VfAcetate were found in semiarid streams, with protein-like DOM, indicating a dominance of reactive, labile compounds. This, together with lower stream respiration rates and molar ratios of DOC to nitrate, suggests a strong C limitation in semiarid streams, likely due to reduced inputs from the catchment. Overall, this study highlights the interplay of climate and DOM composition and its relevance to understand the biogeochemical mechanisms controlling DOC uptake in streams.Theauthors were supported by the following funding: N. C. by a Generalitat de Catalunya-Beatriu de Pinós grant (BP2016–00215), E. E. by a predoctoral grant from the Basque Government, A. G. B. by a Generalitat de Catalunya-Beatriu de Pinós (BP-00385-2016), A. M. G. F. by a predoctoral research grant (BES-2013-065770) from the Spanish Ministry of Economy and Competitiveness, P. R. L. by a Ramón Areces Foundation Postdoctoral Scholarship, and A. L. by a Kempe Foundation stipend. DOMIPEX project was funded by the First Call of Collaborative Projects among Young Researchers of the Iberian Association of Limnology (AIL; 2013–2015)

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV

The t t-bar production cross section (sigma[t t-bar]) is measured in proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS experiment, corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurement is performed in events with two leptons (electrons or muons) in the final state, at least two jets identified as jets originating from b quarks, and the presence of an imbalance in transverse momentum. The measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/- 2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction of the standard model.Comment: Replaced with published version. Included journal reference and DO

Combined search for the quarks of a sequential fourth generation

Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO

Search for anomalous t t-bar production in the highly-boosted all-hadronic final state

A search is presented for a massive particle, generically referred to as a Z', decaying into a t t-bar pair. The search focuses on Z' resonances that are sufficiently massive to produce highly Lorentz-boosted top quarks, which yield collimated decay products that are partially or fully merged into single jets. The analysis uses new methods to analyze jet substructure, providing suppression of the non-top multijet backgrounds. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 5 inverse femtobarns. Upper limits in the range of 1 pb are set on the product of the production cross section and branching fraction for a topcolor Z' modeled for several widths, as well as for a Randall--Sundrum Kaluza--Klein gluon. In addition, the results constrain any enhancement in t t-bar production beyond expectations of the standard model for t t-bar invariant masses larger than 1 TeV.Comment: Submitted to the Journal of High Energy Physics; this version includes a minor typo correction that will be submitted as an erratu