1,089 research outputs found
Bis(2-{5-[(2-carbÂoxyÂphenÂyl)sulfanylmethÂyl]-2,4-dimethylÂbenzylÂsulfanÂyl}benzoato-Îş2 O,O′)bisÂ(pyridine-ÎşN)iron(II)
The title compound, [Fe(C24H21O4S2)2(C5H5N)2], has 2 symmetry. The FeII cation is located on a twofold rotation axis and is O,O′-chelated by two 2-{5-[(2-carbÂoxyÂphenÂyl)sulfanylmethÂyl]-2,4-dimethylÂbenzylÂsulfanÂyl}benzoate anions and further coordinated by two pyridine ligands in a distorted octaÂhedral geometry. In the anion, the terminal benzene rings are oriented at dihedral angles of 63.81 (14) and 84.50 (14)° with respect to the central benzene ring. InterÂmolecular O—Hâ‹ŻO and C—Hâ‹ŻO hydrogen bonding is present in the crystal structure
Removal of Acid Yellow 25 from Aqueous Solution by Chitin Prepared from Waste Snow Crab Legs
Acid Yellow 25 (AY25) is used in the textile industry for dyeing of natural and synthetic fibers, and is also used as a coloring agent in paints, inks, plastics, and leathers. Effluents from such industries are major sources of water pollution. Hence, it is important to find simple, efficient, and inexpensive ways to remove these dyes from wastewater. Here, we determined the suitability of chitin extracted from waste crab legs as an adsorbent for removing AY25 dye. The adsorption kinetics was modeled using pseudo-first order, pseudo-second order, and intraparticle diffusion equations to determine the rate controlling step. Results showed that the pseudo-second order adsorption mechanism is predominant, and the overall rate of the dye adsorption process is therefore controlled by an adsorption reaction. Adsorption isotherms were analyzed by utilizing the Langmuir, Freundlich, Dubinin-Radushkevich (D-R) and Temkin isotherm models at 23ËšC, with data collected by using various initial dye concentrations with different chitin dosages. Our results show the highest correlation with the Langmuir model, consistent with the fact that chitin contains both a monolayer and homogeneous adsorption sites. Based on the D-R model, the adsorption of AY25 dye onto chitin is via chemisorption. Furthermore, we have concluded that the rate constants of both pseudo-second order adsorption and film diffusion are correlated to the initial dye concentrations and chitin dosages. In conclusion, chitin from waste crab legs is a very suitable adsorbent material that is capable of rapidly removing up to 95% of the initial concentration of AY25 dye at a pH of 2 and room temperature
Two new species of Craterellus (Cantharellales, Hydnaceae) with veined hymenophore from north-eastern China
In this contribution to the genus Craterellus in northern China, two new species are introduced: Craterellus connatus and C. striatus. These species and C. atrobrunneolus, initially described in south-western China, are highly similar and closely related. The species delimitation is molecularly supported by multigene phylogenetic analysis of the nr LSU and tef-1α region. Craterellus connatus is characterised by its medium-sized basidiomata, greyish-brown and smooth pileus with an off-white margin, the hymenophore with a strongly anastomosing vein, turning khaki upon drying, connate stipe, broad ellipsoid to ellipsoid basidiospores (6.1–7.8 × 4.8–5.9 μm), slender basidia with (2)4–6 sterigmata and the absence of clamp connection. Craterellus striatus is characterised by its small-sized basidiomata, fibrillose, greyish-brown to yellowish-brown, fully perforated pileus with a brown fringe, the hymenophore with a forking vein, the stipe inflated at the base, broad ellipsoid to ellipsoid basidiospores (6.8–8.0 × 5.1–6.0 μm), 2–6 spored basidia, encrusted hyphae and the absence of clamp connection. Detailed macroscopic and microscopic descriptions, accompanied by illustrations and a taxonomic discussion, are presented. A key to the Chinese Craterellus species is also provided
A Spin-dependent Machine Learning Framework for Transition Metal Oxide Battery Cathode Materials
Owing to the trade-off between the accuracy and efficiency,
machine-learning-potentials (MLPs) have been widely applied in the battery
materials science, enabling atomic-level dynamics description for various
critical processes. However, the challenge arises when dealing with complex
transition metal (TM) oxide cathode materials, as multiple possibilities of
d-orbital electrons localization often lead to convergence to different spin
states (or equivalently local minimums with respect to the spin configurations)
after ab initio self-consistent-field calculations, which causes a significant
obstacle for training MLPs of cathode materials. In this work, we introduce a
solution by incorporating an additional feature - atomic spins - into the
descriptor, based on the pristine deep potential (DP) model, to address the
above issue by distinguishing different spin states of TM ions. We demonstrate
that our proposed scheme provides accurate descriptions for the potential
energies of a variety of representative cathode materials, including the
traditional LiTMO (TM=Ni, Co, Mn, =0.5 and 1.0), Li-Ni anti-sites in
LiNiO (=0.5 and 1.0), cobalt-free high-nickel
LiNiMnO (=1.5 and 0.5), and even a ternary cathode
material LiNiCoMnO (=1.0 and 0.67). We
highlight that our approach allows the utilization of all ab initio results as
a training dataset, regardless of the system being in a spin ground state or
not. Overall, our proposed approach paves the way for efficiently training MLPs
for complex TM oxide cathode materials
Axonal Fiber Terminations Concentrate on Gyri
Convoluted cortical folding and neuronal wiring are 2 prominent attributes of the mammalian brain. However, the macroscale intrinsic relationship between these 2 general cross-species attributes, as well as the underlying principles that sculpt the architecture of the cerebral cortex, remains unclear. Here, we show that the axonal fibers connected to gyri are significantly denser than those connected to sulci. In human, chimpanzee, and macaque brains, a dominant fraction of axonal fibers were found to be connected to the gyri. This finding has been replicated in a range of mammalian brains via diffusion tensor imaging and high–angular resolution diffusion imaging. These results may have shed some lights on fundamental mechanisms for development and organization of the cerebral cortex, suggesting that axonal pushing is a mechanism of cortical folding
Metabolic Rewiring by Loss of Sirt5 Promotes Kras-induced Pancreatic Cancer Progression.
BACKGROUND & AIMS: SIRT5 plays pleiotropic roles via post-translational modifications, serving as a tumor suppressor, or an oncogene, in different tumors. However, the role SIRT5 plays in the initiation and progression of pancreatic ductal adenocarcinoma (PDAC) remains unknown. METHODS: Published datasets and tissue arrays with SIRT5 staining were used to investigate the clinical relevance of SIRT5 in PDAC. Furthermore, to define the role of SIRT5 in the carcinogenesis of PDAC, we generated autochthonous mouse models with conditional Sirt5 knockout. Moreover, to examine the mechanistic role of SIRT5 in PDAC carcinogenesis, SIRT5 was knocked down in PDAC cell lines and organoids, followed by metabolomics and proteomics studies. A novel SIRT5 activator was utilized for therapeutic studies in organoids and patient-derived xenografts. RESULTS: SIRT5 expression negatively regulated tumor cell proliferation and correlated with a favorable prognosis in PDAC patients. Genetic ablation of Sirt5 in PDAC mouse models promoted acinar-to-ductal metaplasia, precursor lesions, and pancreatic tumorigenesis, resulting in poor survival. Mechanistically, SIRT5 loss enhanced glutamine and glutathione metabolism via acetylation-mediated activation of GOT1. A selective SIRT5 activator, MC3138, phenocopied the effects of SIRT5 overexpression and exhibited anti-tumor effects on human PDAC cells. MC3138 also diminished nucleotide pools, sensitizing human PDAC cell lines, organoids, and patient-derived xenografts to gemcitabine. CONCLUSIONS: Collectively, we identify SIRT5 as a key tumor suppressor in PDAC, whose loss promotes tumorigenesis through increased non-canonical utilization of glutamine via GOT1, and that SIRT5 activation is a novel therapeutic strategy to target PDAC
Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation
One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced.
Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI