Unexpected one-pot synthesis of highly conjugated pentacyclic diquinoid compounds

A new class of pentacyclic diquinoid compounds has been synthesized with a facile one-pot reaction of two molecules of 2-hydroxynaphthoquinone and 1-bromoalkanes in the presence of ferrocene. These molecules were isolated as enol tautomers that exhibit intramolecular hydrogen bond and extended electronic conjugation as proved by the intense absorption spectrum with a broad band between 400 and 600 nm. The spectroscopic and electrochemical characterization of this new class of compounds has been performed. One of the synthesized diquinoid derivatives showed a significant cytotoxicity with IC50 values of 25−50 μM against Cisplatin-Resistant SKOV3 and colon carcinoma SW480 cell lines. The results of our study provide a valuable tool to a one-pot synthesis of highly conjugated polyquinones, analogous to important biological systems, with significant antitumoral activity

Produção de massa seca de capim papuã (Brachiaria plantaginea) submetido à adubação nitrogenada com ou sem irrigação em integração lavoura-pecuária.

Este trabalho objetivou quantificar a resposta de níveis de nitrogênio e de irrigação, com ou sem adubação de base, sobre a produção de massa seca do capim papuã

Fast offline data reduction of laser ablation MC-ICP-MS Sr isotope measurements: Via an interactive Excel-based spreadsheet 'SrDR'

Strontium isotopes are applied to a wide range of scientific fields and to different types of materials, providing valuable information foremost about provenance and age, but also on diagenetic processes and mixing relationships between different Sr reservoirs. The development of in situ analytical techniques, such as laser ablation ICP-MS, has improved our understanding of Sr isotope variability in several fields of application, because of the possibility to discriminate small-scale changes and their spatial distribution. However, large outputs of Sr isotope data are produced by laser ablation MC-ICP-MS systems, which necessitate multiple offline steps to correct and assess the data. This requires the availability of simple and user-friendly tools, easily manageable by non-specialists too. With this in mind, we developed SrDR, an Excel-based interactive data reduction spreadsheet ('SrDR', Sr-Data-Reduction) for the processing of Sr isotopes measured by LA-MC-ICP-MS. The SrDR spreadsheet is easily customizable (a) to meet user-specific analytical protocols, (b) for different instruments (i.e. Nu plasma vs. Neptune), and (c) for diverse target materials (e.g. rare earth element enriched or depleted samples). We also include several examples relevant to low and high temperature geochemistry fields-a fossil tooth, a modern seashell, a speleothem sample and plagioclase crystals-to show how different sample materials are corrected for different interfering masses

Avaliação da severidade e reação de resistência a doenças em cinco espécies de trevos na safra 2021.

A produção de forragem no Sul do país está intimamente relacionada com à produtividade de bovinos de corte e de leite no período de inverno, quando as pastagens cultivadas ou naturais são reduzidas, como consequência da enorme carência de alimentação para o gado durante essa estação do ano (Reis, 2007; Montardo, 2002).ODS 2

Resolving protein mixtures using microfluidic diffusional sizing combined with synchrotron radiation circular dichroism

Circular dichroism spectroscopy has become a powerful tool to characterise proteins and other biomolecules. For heterogeneous samples such as those present for interacting proteins, typically only average spectroscopic features can be resolved. Here we overcome this limitation by using free-flow microfluidic size separation in-line with synchrotron radiation circular dichroism to resolve the secondary structure of each component of a model protein mixture containing monomers and fibrils. To enable this objective, we have integrated far-UV compatible measurement chambers into PDMS-based microfluidic devices. Two architectures are proposed so as to accommodate for a wide range of concentrations. The approach, which can be used in combination with other bulk measurement techniques, paves the way to the study of complex mixtures such as the ones associated with protein misfolding and aggregation diseases including Alzheimer’s and Parkinson’s diseases

Caracterização morfológica de genótipos de trevo-alexandrino.

O objetivo deste estudo foi avaliar as características morfológicas de uma população de trevo-alexandrino (LEG 1900), pertencente ao BAG de Leguminosas Forrageiras de Clima Temperado da Embrapa, no estádio inicial de desenvolvimento

Sowing rate and its effects on forage yield of tetraploid ryegrass.

There is a shortage of information about the ryegrass crop (Lolium multiflorum Lam.), especially regarding the suitable sowing rate. Thus, the present work aimed to determine the most adequate sowing rate for tetraploid ryegrass cultivars. A tetraploid ryegrass population was sown at different densities: 150, 300, 600, 900, 1200, 1500, 1800 seeds/m². The number of plants per m², percentage of soil cover, leaf yield and green and dry forage yield were evaluated. The experimental design was randomized blocks with three replications. To observe the behavior of the pasture at different densities for each cut, regression analysis was performed, through which it was possible to verify that the sowing rate has greater influence on the initial cut of the crop. In all the variables analyzed by regression, only the second cut presented a linear trend favorable to the increase in density. In the other cuts, an increase was observed, both in the height of plants and in the yield variables, up to the density of 1500 seeds/m², with a subsequent fall to the highest density, indicating that higher densities may be detrimental to pasture yield. Therefore the density of 1500 seeds/m² is the most suitable for tetraploid ryegrass cultivars