Refrigerated raw milk may contain psychrotrophic microorganisms that produce thermoresistant exoproteases and lipases, which may compromise the quality of processed fluid milk and dairy products ...during storage. The aim of this work was to quantify and identify the deteriorating psychrotrophic microbiota in Brazilian refrigerated raw milk using genetic diversity analysis. The mean psychrotrophic count was 1.1 × 104 cfu/mL. Of the total isolates, 47.8 and 29.8% showed deteriorating activity at 35°C within 48 h and 7°C within 10 d, respectively. Among the proteolytic species, more isolated by this study were Lactococcus lactis (27.3%), Enterobacter kobei (14.8%), Serratia ureilytica (8%), Aerococcus urinaeequi (6.8%), and Bacillus licheniformis (6.8%). Observed among lipolytics were E. kobei (17.7%), L. lactis (15.6%), A. urinaeequi (12.5%), and Acinetobacter lwoffii (9.4%). The isolates S. ureilytica, E. kobei, Pseudomonas spp., and Yersinia enterocolitica potentially produced alkaline metalloprotease (aprX). Despite the low counts, a considerable portion of the psychrotrophic microbiota presented spoilage potential, which reaffirms the need for rigor in the control of contamination and the importance of rapid processing as factors that maintain the quality of milk and dairy products.
Electrochemical oxidative C–H/N–H activations have been accomplished with a versatile cobalt catalyst in terms of 4 + 2 annulations of internal alkynes. The electro-oxidative C–H activation manifold ...proved viable with an undivided cell setup under exceedingly mild reaction conditions at room temperature using earth-abundant cobalt catalysts. The electrochemical cobalt catalysis prevents the use of transition metal oxidants in C–H activation catalysis, generating H2 as the sole byproduct. Detailed mechanistic studies provided strong support for a facile C–H cobaltation by an initially formed cobalt(III) catalyst. The subsequent alkyne migratory insertion was interrogated by mass spectrometry and DFT calculations, providing strong support for a facile C–H activation and the formation of a key seven-membered cobalta(III) cycle in a regioselective fashion. Key to success for the unprecedented use of internal alkynes in electrochemical C–H/N–H activations was represented by the use of N-2-pyridylhydrazides, for which we developed a traceless electrocleavage strategy by electroreductive samarium catalysis at room temperature.
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•Forensic analysis of artwork.•Pigment analysis by FTIR.•Pigment analysis by XRF.•Analysis of artworks by MA-XRF.•Scientific analysis of analytical data.
This work studied suspicious ...and authentic artworks by Brazilian painters Ivan Serpa, Ismael Nery, and Iberê Camargo by XRF, FTIR, OM, and MA-XRF techniques. The studies made it possible to verify that all suspicious artworks are counterfeit artifacts. The analyses were conducted in situ, and different approaches were applied for data treatment. For example, principal component analysis and spectral deconvolution were performed on the XRF data. From these methods, it was possible to verify that the suspect artworks by Ivan Serpa and Iberê Camargo have different materiality than the authentic paintings. Additionally, MA-XRF images did not reveal the presence of a polychrome preparation layer in the suspicious paintings by Ivan Serpa. The suspect artworks from Ismael Nery exhibited a Ca-K/Ti-K ratio that indicates they were created on a low-quality paper support, which is not suitable for paintings. The differences in materials used in the suspicious and authentic artworks are further supported by the FTIR and OM results. In addition to the physicochemical analysis, the paintings were studies graphotechnical examinations, financial evaluations, and artistic analyses that demonstrated they were counterfeit artifacts. The results of the analysis demonstrate how physicochemical techniques can contribute to the forensic investigation of paintings. However, this work highlights the importance of applying distinct treatments to the XRF data in order to accentuate the differences between the suspect and authentic artworks.
A flow-metallaelectro-catalyzed C–H activation was realized in terms of robust rhodaelectro-catalyzed alkyne annulations. To this end, a modular electro-flow cell with a porous graphite felt anode ...was designed to ensure efficient turnover. Thereby, a variety of C–H/N–H functionalizations proved amenable for alkyne annulations with high levels of regioselectivity and functional group tolerance, viable in both an inter- or intramolecular manner. The electro-flow C–H activation allowed easy scale up, while in-operando kinetic analysis was accomplished by online flow-NMR spectroscopy. Mechanistic studies suggest an oxidatively induced reductive elimination pathway on rhodium(III) in an electrocatalytic regime.
In light of Medical Hydrology, thermal waters (TW) are all-natural mineral waters that emerge inside a thermal resort and have therapeutic applications. Their beneficial effect has been empirically ...recognized for centuries, being indicated for symptom alleviation and/or treatment of several diseases, almost all associated with inflammation. Indeed, an anti-inflammatory effect has been attributed to many different Portuguese TW but there is no scientific validation supporting this empiric knowledge. In the present study, we aimed to investigate the anti-inflammatory properties of 14 TW pertaining to thermal centers located in the Central Region of Portugal, and grouped according to their ionic profile. Mouse macrophage cells stimulated with lipopolysaccharide (LPS), a Toll-like receptor 4 agonist, were exposed to culture medium prepared in TW. Metabolism, nitric oxide (NO) production, inducible nitric oxide synthase (iNOS) expression levels and the scavenging capacity of TW, were investigated in vitro. 11 out of 14 TW reduced NO production and/or iNOS expression, and/or scavenging activity, in macrophages exposed to LPS. The sulphated/calcic TW did not show any effect on at least one of the inflammatory parameters evaluated. Two sulphurous/bicarbonate/sodic TW and the sulphurous/chlorinated/sodic TW promoted an increase in NO production and/or iNOS expression. Our results validate, for the first time, the anti-inflammatory properties of Portuguese TW, supporting their therapeutic use in the treatment of inflammation-related diseases and promoting their putative application in cosmetic products and medical devices.
Drought threatens tropical rainforests over seasonal to decadal timescales, but the drivers of tree mortality following drought remain poorly understood. It has been suggested that reduced ...availability of non-structural carbohydrates (NSC) critically increases mortality risk through insufficient carbon supply to metabolism ('carbon starvation'). However, little is known about how NSC stores are affected by drought, especially over the long term, and whether they are more important than hydraulic processes in determining drought-induced mortality. Using data from the world's longest-running experimental drought study in tropical rainforest (in the Brazilian Amazon), we test whether carbon starvation or deterioration of the water-conducting pathways from soil to leaf trigger tree mortality. Biomass loss from mortality in the experimentally droughted forest increased substantially after >10 years of reduced soil moisture availability. The mortality signal was dominated by the death of large trees, which were at a much greater risk of hydraulic deterioration than smaller trees. However, we find no evidence that the droughted trees suffered carbon starvation, as their NSC concentrations were similar to those of non-droughted trees, and growth rates did not decline in either living or dying trees. Our results indicate that hydraulics, rather than carbon starvation, triggers tree death from drought in tropical rainforest.
Asymmetric pallada‐electrocatalyzed C−H olefinations were achieved through the synergistic cooperation with transient directing groups. The electrochemical, atroposelective C−H activations were ...realized with high position‐, diastereo‐, and enantio‐control under mild reaction conditions to obtain highly enantiomerically‐enriched biaryls and fluorinated N−C axially chiral scaffolds. Our strategy provided expedient access to, among others, novel chiral BINOLs, dicarboxylic acids and helicenes of value to asymmetric catalysis. Mechanistic studies by experiments and computation provided key insights into the catalyst's mode of action.
EE: Enantioselective Electrocatalysis was realized in terms of asymmetric C−H activation through transient directing group (TDG)‐enabled pallada‐electrocatalysis. Experiments and calculations rationalize the key transition states, while asymmetric electrocatalysis provided step‐economical access to axially chiral bi(hetero)aryl diols, diacids and helicenes.
Dengue disease is an acute viral illness caused by dengue virus (DENV) that can progress to hemorrhagic stages leading to about 20000 deaths every year worldwide. Despite many clinical investigations ...regarding dengue, the immunopathogenic process by which infected patients evolve to the severe forms is not fully understood. Apart from differences in virulence and the antibody cross reactivity that can potentially augment virus replication, imbalanced cellular immunity is also seen as a major concern in the establishment of severe dengue. In this context, the investigation of cellular immunity and its products in dengue fatal cases may provide valuable data to help revealing dengue immunopathogenesis. Here, based in four dengue fatal cases infected by the serotype 3 in Brazil, different peripheral organs (livers, lungs and kidneys) were studied to evaluate the presence of cell infiltrates and the patterns of local cytokine response. The overall scenario of the studied cases revealed a considerable systemic involvement of infection with mononuclear cells targeted to all of the evaluated organs, as measured by immunohistochemistry (IHC). Quantification of cytokine-expressing cells in peripheral tissues was also performed to characterize the ongoing inflammatory process by the severe stage of the disease. Increased levels of IFN-γ- and TNF-α-expressing cells in liver, lung and kidney samples of post-mortem subjects evidenced a strong pro-inflammatory induction in these tissues. The presence of increased RANTES-producing cell numbers in all analyzed organs suggested a possible link between the clinical status and altered vascular permeability. Co-staining of DENV RNA and IFN-γ or TNF-α using in situ hibridization and IHC confirmed the virus-specific trigger of the pro-inflammatory response. Taken together, this work provided additional evidences that corroborated with the traditional theories regarding the "cytokine storm" and the occurrence of uneven cellular immunity in response to DENV as major reasons for progress to severe disease.
Atropoisomeric (hetero)biaryls are scaffolds with increasing importance in the pharmaceutical and agrochemical industries. Although it is the most obvious disconnection to construct such compounds, ...the direct enantioselective C–H arylation through the concomitant induction of the chiral information remains extremely challenging and uncommon. Herein, the unprecedented earth-abundant 3d-metal-catalyzed atroposelective direct arylation is reported, furnishing rare atropoisomeric C2-arylated indoles. Kinetic studies and DFT computation revealed an uncommon mechanism for this asymmetric transformation, with the oxidative addition being the rate- and enantio-determining step. Excellent stereoselectivities were reached (up to 96% ee), while using an unusual N-heterocyclic carbene ligand bearing an essential remote substituent. Attractive dispersion interactions along with positive C–H---π interactions exerted by the ligand were identified as key factors to guarantee the excellent enantioselection.
The enantioselective cobalt(III)‐catalyzed C−H alkylation was achieved through the design of a novel chiral acid. The cobalt(III)‐catalyzed enantioselective C−H activation was characterized by high ...position‐, regio‐ and enantio‐control under exceedingly mild reaction conditions. Thereby, the robust cooperative cobalt(III) catalysis proved tolerant of valuable electrophilic functional groups, including hydroxyl, bromo, and iodo substituents. Mechanistic studies revealed a considerable additive effect on kinetics and on a negative non‐linear‐effect.
CoIII goes chiral: Enantioselective Cp*CoIII‐catalyzed C−H functionalization was realized by synergistic cooperation with a newly developed chiral carboxylic acid for robust and versatile C−H activation.
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