1,181 research outputs found

    Bis(2-{5-[(2-carb­oxy­phen­yl)sulfanylmeth­yl]-2,4-dimethyl­benzyl­sulfan­yl}benzoato-κ2 O,O′)bis­(pyridine-κN)iron(II)

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    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-carb­oxy­phen­yl)sulfanylmeth­yl]-2,4-dimethyl­benzyl­sulfan­yl}benzoate anions and further coordinated by two pyridine ligands in a distorted octa­hedral 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. Inter­molecular O—H⋯O and C—H⋯O hydrogen bonding is present in the crystal structure

    Quantum delayed-choice experiment with a beam splitter in a quantum superposition

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    A quantum system can behave as a wave or as a particle, depending on the experimental arrangement. When for example measuring a photon using a Mach-Zehnder interferometer, the photon acts as a wave if the second beam-splitter is inserted, but as a particle if this beam-splitter is omitted. The decision of whether or not to insert this beam-splitter can be made after the photon has entered the interferometer, as in Wheeler's famous delayed-choice thought experiment. In recent quantum versions of this experiment, this decision is controlled by a quantum ancilla, while the beam splitter is itself still a classical object. Here we propose and realize a variant of the quantum delayed-choice experiment. We configure a superconducting quantum circuit as a Ramsey interferometer, where the element that acts as the first beam-splitter can be put in a quantum superposition of its active and inactive states, as verified by the negative values of its Wigner function. We show that this enables the wave and particle aspects of the system to be observed with a single setup, without involving an ancilla that is not itself a part of the interferometer. We also study the transition of this quantum beam-splitter from a quantum to a classical object due to decoherence, as observed by monitoring the interferometer output.Comment: 9 pages, 7 figures, Accepted by Physical Review Letter

    Prediabetes is associated with a higher serum neurofilament light chain level in adolescents

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    ObjectiveSerum neurofilament light chain (sNfL) level, which is a biomarker indicative of neuroaxonal damage and cognitive impairment, has been reported in several neurological diseases. There has been a lack of studies on the association between sNfL levels and prediabetes in adolescents. This study investigated whether sNfL levels were higher in adolescents with prediabetes undergoing elective orthopedic surgery.MethodsThe sNfL level was measured in 149 adolescents aged from 12 to 18 years who underwent elective orthopedic surgery at the Hunan Children’s Hospital (18 with and 131 without prediabetes). We evaluated the association between prediabetes and sNfL level after adjusting for age, sex, and triglycerides using a multivariable linear regression model.ResultsThe prevalence of prediabetes in adolescents was 12.08%. Univariate logistic regression analysis showed that prediabetes was related to sNfL. In multivariate logistic regression analysis, the association between prediabetes with sNfL levels remained significant after adjustment for age, sex, and triglyceride. The relationship between the two was further visualized by a smoothed curve.ConclusionsPrediabetes is associated with a higher sNfL. Further large-scale and prospective studies are needed to verify the clinical application of sNfL as a monitoring biomarker for adolescent prediabetes in adolescents and to evaluate the performance of sNfL in predicting the incidence of neuropathy and cognitive dysfunction in adolescents with prediabetes

    Removal of Acid Yellow 25 from Aqueous Solution by Chitin Prepared from Waste Snow Crab Legs

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    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 23˚C, 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

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    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

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    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 Lix_xTMO2_2 (TM=Ni, Co, Mn, xx=0.5 and 1.0), Li-Ni anti-sites in Lix_xNiO2_2 (xx=0.5 and 1.0), cobalt-free high-nickel Lix_xNi1.5_{1.5}Mn0.5_{0.5}O4_4 (xx=1.5 and 0.5), and even a ternary cathode material Lix_xNi1/3_{1/3}Co1/3_{1/3}Mn1/3_{1/3}O2_2 (xx=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

    Case report: Novel compound heterozygous variants in the PANK2 gene in a Chinese patient diagnosed with ASD and ADHD

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    The PANK2 gene, which encodes mitochondrial pantothenate kinase 2 protein, is the disease-causing gene for pantothenate kinase-associated neurodegeneration (PKAN). We report a case of atypical PKAN with autism-like symptoms presenting with speech difficulties, psychiatric symptoms, and mild developmental retardation. Magnetic resonance imaging (MRI) of the brain showed the typical “eye-of-the-tiger” sign. Whole-exon sequencing revealed PANK2 p.Ile501Asn/p.Thr498Ser compound heterozygous variants. Our study highlights the phenotypic heterogeneity of PKAN, which can be confused with autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD) and requires careful clinical identification

    The Prevalence of Colistin Resistant Strains and Antibiotic Resistance Gene Profiles in Funan River, China

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    Anthropogenic activities near urban rivers may have significantly increased the acquisition and dissemination of antibiotic resistance. In this study, we investigated the prevalence of colistin resistant strains in the Funan River in Chengdu, China. A total of 18 mcr-1-positive isolates (17 Escherichia coli and 1 Enterobacter cloacae) and 6 mcr-3-positive isolates (2 Aeromonas veronii and 4 Aeromonas hydrophila) were detected, while mcr-2, mcr-4 and mcr-5 genes were not detected in any isolates. To further explore the overall antibiotic resistance in the Funan River, water samples were assayed for the presence of 15 antibiotic resistance genes (ARGs) and class 1 integrons gene (intI1). Nine genes, sul1, sul2, intI1, aac(6′)-Ib-cr, blaCTX-M, tetM, ermB, qnrS, and aph(3′)-IIIa were found at high frequencies (70–100%) of the water samples. It is worth noting that mcr-1, blaKPC, blaNDM and vanA genes were also found in water samples, the genes that have been rarely reported in natural river systems. The absolute abundance of selected antibiotic resistance genes [sul1, aac(6′)-Ib-cr, ermB, blaCTX-M, mcr-1, and tetM] ranged from 0 to 6.0 (log10 GC/mL) in water samples, as determined by quantitative polymerase chain reaction (qPCR). The sul1, aac(6′)-Ib-cr, and ermB genes exhibited the highest absolute abundances, with 5.8, 5.8, and 6.0 log10 GC/mL, respectively. The absolute abundances of six antibiotic resistance genes were highest near a residential sewage outlet. The findings indicated that the discharge of resident sewage might contribute to the dissemination of antibiotic resistant genes in this urban river. The observed high levels of these genes reflect the serious degree of antibiotic resistant pollution in the Funan River, which might present a threat to public health

    DeePMD-kit v2: A software package for Deep Potential models

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    DeePMD-kit is a powerful open-source software package that facilitates molecular dynamics simulations using machine learning potentials (MLP) known as Deep Potential (DP) models. This package, which was released in 2017, has been widely used in the fields of physics, chemistry, biology, and material science for studying atomistic systems. The current version of DeePMD-kit offers numerous advanced features such as DeepPot-SE, attention-based and hybrid descriptors, the ability to fit tensile properties, type embedding, model deviation, Deep Potential - Range Correction (DPRc), Deep Potential Long Range (DPLR), GPU support for customized operators, model compression, non-von Neumann molecular dynamics (NVNMD), and improved usability, including documentation, compiled binary packages, graphical user interfaces (GUI), and application programming interfaces (API). This article presents an overview of the current major version of the DeePMD-kit package, highlighting its features and technical details. Additionally, the article benchmarks the accuracy and efficiency of different models and discusses ongoing developments.Comment: 51 pages, 2 figure
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