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View Article and Find Full Text PDFCarbon dots (CDs) are low-cost light-absorbers in photocatalytic multicomponent systems, but their wide size distribution has hampered rational design and the identification of the factors that lead to their best performance. To address this challenge, we report herein the use of gel filtration size exclusion chromatography to separate amorphous, graphitic, and graphitic N-doped CDs depending on their lateral size to study the effect of their size on photocatalytic H evolution with a DuBois-type Ni cocatalyst. Transmission electron microscopy and dynamic light scattering confirm the size-dependent separation of the CDs, whereas UV-vis and fluorescence spectroscopy of the more monodisperse fractions show a distinct response which computational modelling attributes to a complex interplay between CD size and optical properties.
View Article and Find Full Text PDFLand use change in pastures is considered one of the leading drivers of tropical deforestation in the Ecuadorian Amazon Region (EAR). To halt and reverse this process, it is necessary to understand, among other factors, the local livelihoods, income from grazing area and the appropriate options to foster sustainable production, incorporating the land-sparing and land-sharing approach. This work was conducted using 167 household surveys along an altitudinal gradient within the buffer and transition zone of the Sumaco Biosphere Reserve (SBR) in the EAR.
View Article and Find Full Text PDFEpithelial-mesenchymal transition (EMT) fosters cancer cell invasion and metastasis, the main cause of cancer-related mortality. Growing evidence that SNAIL and ZEB transcription factors, typically portrayed as master regulators of EMT, may be dispensable for this process, led us to re-investigate its mechanistic underpinnings. For this, we used an unbiased computational approach that integrated time-resolved analyses of chromatin structure and differential gene expression, to predict transcriptional regulators of TGFβ1-inducible EMT in the MCF10A mammary epithelial cell line model.
View Article and Find Full Text PDFWe report a H evolving hybrid photocathode based on SbSe and a precious metal free molecular catalyst. Through the use of a high surface area TiO scaffold, we successfully increased the Ni molecular catalyst loading from 7.08 ± 0.
View Article and Find Full Text PDFHollow-core photonic crystal fibers (HC-PCFs) provide a novel approach for in situ UV/Vis spectroscopy with enhanced detection sensitivity. Here, we demonstrate that longer optical path lengths than afforded by conventional cuvette-based UV/Vis spectroscopy can be used to detect and identify the Co and Co states in hydrogen-evolving cobaloxime catalysts, with spectral identification aided by comparison with DFT-simulated spectra. Our findings show that there are two types of signals observed for these molecular catalysts; a transient signal and a steady-state signal, with the former being assigned to the Co state and the latter being assigned to the Co state.
View Article and Find Full Text PDFThis paper examines the role of women in the dual-purpose livestock system (DP) in Mexico through their technological adoption patterns and aims to evaluate whether there are significant differences between the technology adoption networks of men and women farmers. The sample was composed of 383 DP small farms with 20 or fewer cows and a high level of vulnerability. Social Network Analysis (SNA) was applied, and the centrality measures were calculated for the technological areas of management, feeding, genetics, reproduction, and animal health.
View Article and Find Full Text PDFWater oxidation is the step limiting the efficiency of electrocatalytic hydrogen production from water. Spectroelectrochemical analyses are employed to make a direct comparison of water oxidation reaction kinetics between a molecular catalyst, the dimeric iridium catalyst [Ir(pyalc)(HO)-(μ-O)] (, pyalc = 2-(2'pyridinyl)-2-propanolate) immobilized on a mesoporous indium tin oxide (ITO) substrate, with that of an heterogeneous electrocatalyst, an amorphous hydrous iridium () film. For both systems, four analogous redox states were detected, with the formation of Ir(4+)-Ir(5+) being the potential-determining step in both cases.
View Article and Find Full Text PDFAn integrated rearing system for under environmental conditions in an experimental orchard is proposed. In this study, the natural behaviour, circadian rhythms and suitable rearing conditions of the edible snail were optimised to produce homogeneous growth and low variability. The growth was standardised, and growth pattern fit was assessed with various models.
View Article and Find Full Text PDFThe Guayas, located in Ecuador, is the largest basin in the Pacific Ocean and has an inventory of 123 native freshwater species. Most of these are endemic species that are threatened or at-risk due to anthropogenic activity and the modification, fragmentation, and destruction of habitats. The aim of this study was to determine the morphometric variation in three wild populations of in the Guayas basin rivers and their connections to fishing management and environmental conditions.
View Article and Find Full Text PDFMulti-redox catalysis requires the accumulation of more than one charge carrier and is crucial for solar energy conversion into fuels and valuable chemicals. In photo(electro)chemical systems, however, the necessary accumulation of multiple, long-lived charges is challenged by recombination with their counterparts. Herein, we investigate charge accumulation in two model multi-redox molecular catalysts for proton and CO reduction attached onto mesoporous TiO electrodes.
View Article and Find Full Text PDFDye-sensitised photoanodes modified with a water oxidation catalyst allow for solar-driven O evolution in photoelectrochemical cells. However, organic chromophores are generally considered unsuitable to drive the thermodynamically demanding water oxidation reaction, mainly due to their lack of stability upon photoexcitation. Here, the synthesis of a dyad photocatalyst () consisting of a diketopyrrolopyrrole chromophore () and ruthenium-based water oxidation catalyst () is described.
View Article and Find Full Text PDFThe aim of this research was to find out the morphometric differentiation of six native freshwater species in the Guayas Hydrographic Basin (Ecuador) by means of discriminant analysis. A total of 1355 mature fishes ( and ) were captured and 27 morphometric measurements and 20 landmarks were used. Two-way analysis of variance with species and sex as fixed factors and discriminant analysis were applied.
View Article and Find Full Text PDFPerforming quantitative in situ spectroscopic analysis on minuscule sample volumes is a common difficulty in photochemistry. To address this challenge, we use a hollow-core photonic crystal fiber (HC-PCF) that guides light at the center of a microscale liquid channel and acts as an optofluidic microreactor with a reaction volume of less than 35 nL. The system was used to demonstrate in situ optical detection of photoreduction processes that are key components of many photocatalytic reaction schemes.
View Article and Find Full Text PDFEcuador, a country exhibiting large developments in fish farming, has a great variety of freshwater native fish. Among these fish is the or chame, which has characteristics that make its farming prone to occur at a quite-developed stage. However, morphological characterization is required to establish a conservation program.
View Article and Find Full Text PDFDye-sensitized photoelectrochemical (DSPEC) cells are an emerging approach to producing solar fuels. The recent development of delafossite CuCrO as a p-type semiconductor has enabled H generation through the coassembly of catalyst and dye components. Here, we present a CuCrO electrode based on a high-surface-area inverse opal (IO) architecture with benchmark performance in DSPEC H generation.
View Article and Find Full Text PDFDual-purpose cattle smallholder farms (DP) exhibit a critical economic situation. The objective of this research was building a typology for DP in tropical conditions and characterizing them technologically. This will help developing more effective public policies in DP farms located in tropical conditions.
View Article and Find Full Text PDFA modular strategy has been employed to develop a new class of fluorescent molecules, which generates discrete, dimeric stacked fluorophores upon complexation with multiple cucurbit[8]uril macrocycles. The multiple constraints result in a "static" complex (remaining as a single entity for more than 30 ms) and facilitate fluorophore coupling in the ground state, showing a significant bathochromic shift in absorption and emission. This modular design is surprisingly applicable and flexible and has been validated through an investigation of nine different fluorophore cores ranging in size, shape, and geometric variation of their clamping modules.
View Article and Find Full Text PDFCucurbit[8]uril (CB[8]) mediated assembly of extended aryl viologens (EVs) into optically tunable dimers is reported for the first time. We show that the modular design and synthesis of a new class of π-conjugated viologen derivatives with rigid aromatic or heteroaromatic bridging units as well as electron donating molecular recognition motifs enable their self-assembly into 2 : 2 complexes with CB[8]. The quantitative dimerization process involving these two molecular components in an aqueous solution enables excimer-like interactions between closely packed charged guests giving rise to distinct spectroscopic behavior.
View Article and Find Full Text PDFAt the molecular level, epithelial-to-mesenchymal transition (EMT) necessitates extensive transcriptional reprogramming which is orchestrated by a small group of gene-regulatory factors that include the zinc-finger DNA-binding protein SNAIL1. Although SNAIL1 is a well-known master regulator of EMT, knowledge of its immediate target genes is incomplete. Here, we used ChIP-seq to identify genes directly regulated by SNAIL1 in colorectal adenocarcinoma cells.
View Article and Find Full Text PDFA series of six novel [Ir(C^N)2(N^N)](PF6) complexes (C^N is one of two cyclometalating ligands: 2-phenyl-4-(2,4,6-trimethylphenyl)pyridine, MesppyH, or 2-(napthalen-1-yl)-4-(2,4,6-trimethylphenyl)pyridine, MesnpyH; N^N denotes one of four neutral diamine ligands: 4,4'-di-tert-butyl-2,2'-bipyridine, dtbubpy, 1H,1'H-2,2'-bibenzimiazole, H2bibenz, 1,1'-(α,α'-o-xylylene)-2,2'-bibenzimidazole, o-xylbibenz or 2,2'-biquinoline, biq) were synthesised and their structural, electrochemical and photophysical properties comprehensively characterised. The more conjugated MesnpyH ligands confer a red-shift in the emission compared to MesppyH but maintain high photoluminescence quantum yields due to the steric bulk of the mesityl groups. The H2bibenz and o-xylbibenz ligands are shown to be electronically indistinct to dtbubpy but give complexes with higher quantum yields than analogous complexes bearing dtbubpy.
View Article and Find Full Text PDFThe south of Iberia conserves an important group of Palaeolithic rock art sites. The graphisms have been mostly attributed to the Solutrean and Magdalenian periods, while the possibility that older remains exist has provoked extensive debate. This circumstance has been linked to both the cited periods, until recently, due to the transition from the Middle to Upper Palaeolithic in the extreme southwest of Europe as well as the non-existence of some of the early periods of Palaeolithic art documented in northern Iberia.
View Article and Find Full Text PDFThe venereal diseases bovine trichomoniasis (BT) and bovine genital campylobacteriosis (BGC) cause economic losses in endemic areas like La Pampa province in Argentina where beef cattle are usually extensively managed. This study used data compiled between 2007 and 2014 by a Provincial Program for the Control and Eradication of venereal diseases in order to develop and analyze retrospective models of time series for BT and BGC. Seasonality and long-term trend were explored with decomposition and simple regression methods.
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