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Developing a highly active, durable, and low-platinum-based electrocatalyst for the cathodic oxygen reduction reaction (ORR) is for breaking the bottleneck of large-scale applications of proton exchange membrane fuel cells (PEMFCs). Herein, ultrafine PtZn intermetallic nanoparticles with low Pt-loading and trace germanium (Ge) involvement confined in the nitrogen-doped porous carbon (Ge-L10-PtZn@N-C) are reported. The Ge-L10-PtZn@N-C exhibit superior ORR activity with a mass activity of 3.04 A mg-1 Pt and specific activity of 4.69 mA cm-2, ≈12.2- and 10.2-times improvement compared to the commercial Pt/C (20%) at 0.90 V in 0.1 m KOH. The cathodic catalyst Ge-L10-PtZn@N-C assembled in the PEMFC shows encouraging peak power densities of 316.5 (at 0.86 V) and 417.2 mW cm-2 (at 0.91 V) in alkaline and acidic fuel-cell, respectively. The combination of experiment and density functional theory calculations (DFT) results robustly reveal that the participation of trace Ge can not only trigger a "growth site locking effect" to effectively inhibit nanoparticle growth, bring miniature nanoparticles, enhance dispersion uniformity, and achieve the exposure of the more electrochemical active site, but also effectively modulates the electronic structure, hence optimizing the adsorption/desorption of the oxygen intermediates.
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Phase engineering of Pt-based intermetallic catalysts has been demonstrated as a promising strategy to optimize catalytic properties for a direct formic acid fuel cell. Pt-Bi intermetallic catalysts are attracting increasing interest due to their high catalytic activity, especially for inhibiting CO poisoning. However, the phase transformation and synthesis of intermetallic compounds usually occurring at high temperatures leads to a lack of control of the size and composition. Here, we report the synthesis of intermetallic ß-PtBi2 and γ-PtBi2 two-dimensional nanoplates with controlled sizes and compositions under mild conditions. The different phases of intermetallic PtBi2 can significantly affect the catalytic performance of the formic acid oxidation reaction (FAOR). The obtained ß-PtBi2 nanoplates exhibit an excellent mass activity of 1.1 ± 0.01 A mgPt-1 for the FAOR, which is 30-fold higher than that of commercial Pt/C catalysts. Moreover, intermetallic PtBi2 demonstrates high tolerance to CO poisoning, as confirmed by in situ infrared absorption spectroscopy.
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Lithium-sulfur battery has attracted significant attention by virtues of their high theoretical energy density, natural abundance, and environmental friendliness. However, the notorious shuttle effect of polysulfides intermediates severely hinders its practical application. Herein, a novel 2D mesoporous N-doped carbon nanosheet with confined bimetallic CoNi nanoparticles sandwiched graphene (mNC-CoNi@rGO) is successfully fabricated through a coordinating interface polymerization and micelle mediated co-assembly strategy. mNC-CoNi@rGO serves as a robust host material that endows lithium-sulfur batteries with a high reversible capacity of 1115 mAh g-1 at 0.2 C after 100 cycles, superior rate capability, and excellent cycling stability with 679.2 mAh g-1 capacity retention over 700 cycles at 1 C. With sulfur contents of up to 5.0 mg cm-2 , the area capacity remains to be 5.1 mAh cm-2 after 100 cycles at 0.2 C. The remarkable performance is further resolved via a series of experimental characterizations combined with density functional theory calculations. These results reveal that the ordered mesoporous N-doped carbon-encapsulated graphene framework acts as the ion/electron transport highway with excellent electrical conductivity, while bimetallic CoNi nanoparticles enhance the polysulfides adsorption and catalytic conversion that simultaneously accelerate the multiphase sulfur/polysulfides/sulfides conversion and inhibit the polysulfides shuttle.
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The design of highly active and durable catalysts for the sluggish anodic oxygen evolution reaction (OER) in acid remains an urgent yet challenging goal in water electrolysis. Herein, a core-shell nanostructured Ru@Ir-O catalyst with tensile strains and incorporated oxygens is introduced in the Ir shell that holds an extremely low OER overpotential of 238 mV at 10 mA cm-2 in acid. The material also shows a remarkable 78-fold higher mass activity than the conventional IrO2 at 1.55 V in 0.5 M H2 SO4 . Structural characterization and theoretical calculations reveal that the core-shell interaction and tensile strain cause band position shift and charge redistribution. These electronic factors furthermore optimize the bonding strength of O* and HOO* intermediates on the surface, yielding significantly boosted OER activity relative to the conventional IrO2 .
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The controlled synthesis of mesoporous metal oxides remains a great challenge because the uncontrolled assembly process and high-temperature crystallization can easily destroy the mesostructure. Herein, we develop a facile, versatile, low-cost, and controllable molten salt assisted assembly strategy to synthesize mesoporous metal oxides (e.g., CeO2, ZrO2, SnO2, Li2TiO3) with high surface area (115-155 m2/g) and uniform mesopore size (3.0 nm). We find this molten salt mediated assembly enables the desolvation of the precursors and forms bare metal ions, enhances their coordination interaction with the surfactant, and promotes their assembly into a mesostructure. Furthermore, the molten salt assisted crystallization process can lower the collision probability of the target metal atom, inhibit its further growth into large crystals, and achieve a well-maintained mesostructure with high crystallization. Furthermore, this method can be expanded to synthesize various structured mesoporous metal oxides, including hollow spheres, nanotubes, and nanosheets by introducing the carbon template. The obtained mesoporous CeO2 microspheres loaded with Cu species exhibit excellent antibacterial performance and superior catalytic activity for the hydrogenation of nitrophenol with high conversion and cycling stability.
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Background: The advantages of the dissecting the metastatic lymph nodes posterior to the right recurrent laryngeal nerve (LN-prRLN) remain a great deal of controversies in papillary thyroid carcinoma (PTC) patients without clinical evidence. The purpose of our retrospective research was to investigate the predictive factors of the LN-prRLN in cN0 PTC patients. Methods and Materials: Altogether 251 consecutive cN0 PTC participants accepted unilateral or bilateral thyroidectomy accompanied with LN-prRLN dissection between June 2020 and May 2023 were included in the research. Then, univariate and multivariate logical regression analysis were conducted to analyze the relationship between the LN-prRLN and these predictive factors, and a predictive model was also developed. Surgical complications of LN-prRLN dissection were also presented. Results: The rate of LN-prRLN was 17.9% (45/251) in cN0 PTC patients after the analysis of postoperative histology. The age <55 years, multifocality, microcalcification, and BRAFV600E mutation were identified to be predictive factors of LN-prRLN in cN0 PTC patients. The risk score for LN-prRLN was calculated: risk score = 1.192 × (if age <55 years) + 0.808 × (if multifocality) + 1.196 × (if microcalcification in nodule) + 0.918 × (if BRAFV600E mutation in nodule). The rates of the transient hypoparathyroidism and hoarseness were 1.2% (3/251) and 2.0% (5/251), respectively. Conclusion: The age <55 years, multifocality, microcalcification, and BRAFV600E mutation are independent predictors of the LN-prRLN in cN0 PTC patients. An effective predictive model was established for predicting the LN-prRLN in cN0 PTC patients, with the aim to better guide the surgical treatment of PTC. A thorough inspection of the lateral compartment is recommended in PTC patients with risk factors. The multicenter research with long-term follow-up should be carried out to ascertain the optimal surgical approach for patients with PTC.
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In the title mol-ecule, C(9)H(10)N(4)S, the dihedral angle between the benzene and triazole rings is 81.05â (5)°. In the crystal, N-Hâ¯N hydrogen bonds link the mol-ecules into infinite zigzag chains along [010].
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Objectives: Use Bayes statistical methods to analyze the factors related to the working ability of petroleum workers in China and establish a predictive model for prediction so as to provide a reference for improving the working ability of petroleum workers. Materials and methods: The data come from the health questionnaire database of petroleum workers in the Karamay region, Xinjiang, China. The database contains the results of a health questionnaire survey conducted with 4,259 petroleum workers. We established an unsupervised Bayesian network, using Node-Force to analyze the dependencies between influencing factors, and established a supervised Bayesian network, using mutual information analysis methods (MI) to influence factors of oil workers' work ability. We used the Bayesian target interpretation tree model to observe changes in the probability distribution of work ability classification under different conditions of important influencing factors. In addition, we established the Tree Augmented Naïve Bayes (TAN) prediction model to improve work ability, make predictions, and conduct an evaluation. Results: (1) The unsupervised Bayesian network shows that there is a direct relationship between shoulder and neck musculoskeletal diseases, anxiety, working age, and work ability, (2) The supervised Bayesian network shows that anxiety, depression, shoulder and neck musculoskeletal diseases (Musculoskeletal Disorders, MSDs), low back musculoskeletal disorders (Musculoskeletal Disorders, MSDs), working years, age, occupational stress, and hypertension are relatively important factors that affect work ability. Other factors have a relative impact on work ability but are less important. Conclusion: Anxiety, depression, shoulder and neck MSDs, waist and back MSDs, and length of service are important influencing factors of work ability. The Tree Augmented Naïve Bayes prediction model has general performance in predicting workers' work ability, and the Bayesian model needs to be deepened in subsequent research and a more appropriate forecasting method should be chosen.
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Yolk-shell structure with magnetic core, interior void and mesoporous polymer/carbon shell demonstrate potential applications in biocatalysis, magnetic biological separation, biomedicine, and magnetic resonance imaging due to their comprehensive benefits of magnetic and mesoporous shells. Herein, yolk-shell structured magnetic mesoporous polydopamine microspheres (Fe3O4@Void@mPDA) and the corresponding derivatives of carbon-based microspheres (Fe3O4@Void@mCN) are successfully fabricated through an interface assembly and selective etching approach. The obtained monodisperse Fe3O4@Void@mPDA microspheres consist of a magnetic core, a mesoporous polydopamine shell, and the large void formed between them, with perpendicular mesopores (5.2 nm), high surface area (303.3 m2g-1), and richness of functional groups. The Fe3O4@Void@mPDA microspheres show a remarkable inhibitory effect on tumor cells. Moreover, the Fe3O4@Void@mCN microspheres can immobilize ultrafine Au nanoparticles for hydrogenation of 4-nitrophenol with superb catalytic activity and excellent magnetic reusability.
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Uranium extraction from seawater is particularly significant and regarded as an indispensable strategy for satisfying the increasing demand for nuclear fuel owing to the high uranium reserves (about 4.5 billion tons) in seawater, while remains great challenges due to the low concentration, the interference of various cations and the complexity of the marine environment. Thus, developing a highly efficient adsorbent with high adsorption capacity, excellent selectivity, low cost, and facile synthesis method is significant and urgently required. Inorganic materials show many advantages in adsorption such as low cost, fast response, high stability, etc, while conventionally, have poor capacity and selectivity especially in real seawater. Herein, mesoporous CaCO3 (mCaCO3) with vaterite phase is synthesized by a facile nanoemulsion strategy and "ready-to-use" for uranium adsorption without functionalization and post treatment. Surfactant Pluronic F127 not only assembles into reverse micelles to form mesopores, but also stabilizes the active vaterite phase. The obtained mCaCO3 with high surface area (48.2 m2/g), interconnected mesopores (11 nm), and unique vaterite phase achieves highly efficient uranium adsorption with a maximum adsorption capacity of 850 ± 20 mg-U/g in uranium-spiked seawater and 6.5 ± 0.5 mg-U/g in 700 L of natural seawater for one week, as well as excellent selectivity, matching the state-of-the-art U adsorbents. After adsorption, mCaCO3-U is dissolved with a simple acid elution to obtain concentrated uranyl solution for purification, avoiding the disposal of adsorbents. To the best of our knowledge, this is the first case to report mesoporous CaCO3 for uranium adsorption from seawater with such a good performance. The facile synthesis, abundant raw materials and eco-friendly adsorption-desorption processes endow the mCaCO3 as a promising candidate for large-scale uranium extraction from seawater.
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Urânio , Adsorção , Carbonato de Cálcio , Água do MarRESUMO
Objective: The aim of this study was to investigate the relevance of metabolic syndrome (MetS) and metabolic scores to the occurrence, progression and prognosis of metastatic prostate cancer (mPCA), assessing the definition of the variables of metabolic syndrome, and the potential mechanisms of MetS and mPCA. Methods: Data were obtained from the database of prostate cancer follow-up at the Urology Centre of the First Affiliated Hospital of Xinjiang Medical University (N=1303). After screening by inclusion and exclusion criteria, clinical data of 190 patients diagnosed with mPCA by pathology and imaging from January 2010 to August 2021 were finally included, including 111 cases in the MetS group and 79 cases in the Non-MetS group. Results: The MetS group was higher than the Non-MetS group: T stage, Gleasson score, initial PSA, tumor load, PSA after 7 months of ADT (P<0.05),with a shorter time to progression to CRPC stage(P<0.05)[where the time to progression to CRPC was relatively shorter in the high metabolic score subgroup of the MetS group than in the low subgroup (P<0.05)].Median survival time was significantly shorter in the MetS group than in the Non-MetS group (P<0.05),and there was a correlation with metabolic score, with the higher metabolic score subgroup having a lower survival time than the lower metabolic score subgroup (P<0.05). Conclusion: Those with mPCA combined with MetS had lower PSA remission rates, more aggressive tumors, shorter time to progression to CRPC and shorter median survival times than those with mPCA without MetS.Tumour progression and metabolic score showed a positive correlation, predicting that MetS may promote the progression of mPCA, suggesting that MetS may be a risk factor affecting the prognosis of mPCA.
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Síndrome Metabólica , Neoplasias de Próstata Resistentes à Castração , Masculino , Humanos , Antígeno Prostático Específico , Neoplasias de Próstata Resistentes à Castração/patologia , Síndrome Metabólica/complicações , Correlação de Dados , PrognósticoRESUMO
In the title compound, C(8)H(8)ClNO, the acetamide group is twisted out the benzene plane with a dihedral angle of 83.08â (1)°. In the crystal, mol-ecules are linked by N-Hâ¯O hydrogen bonds, forming layers parallel to the ab plane.
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In the title compound, C(8)H(7)ClN(4), the phenyl and tetra-zole rings are inclined at a dihedral angle of 67.52â (6)°. In the crystal, mol-ecules are linked by an N-Hâ¯N hydrogen bond into a chain structure along [010]. π-π inter-actions with centroid-centroid distances of 3.526â (1)â Å between adjacent tetra-zole rings further link the chains, forming a ribbon structure.
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The fermentation of biomass allows for the generation of major renewable ethanol biofuel that has high energy density favorable for direct alcohol fuel cells in alkaline media. However, selective conversion of ethanol to either CO2 or acetate remains a great challenge. Especially, the ethanol-to-acetate route usually demonstrates decentoxidation current density relative to the ethanol-to-CO2 route that contains strongly adsorbed poisons. This makes the total oxidation of ethanol to CO2 unnecessary. Here, we present a highly active ethanol oxidation electrocatalyst that was prepared by in situ decorating highly dispersed Mo sites on Pd nanosheets (MoOx/Pd) via a surfactant-free and facile route. We found that â¼2 atom % of Mo on Pd nanosheets increases the current density to 3.8 A mgPd-1, around 2 times more active relative to the undecorated Pd nanosheets, achieving nearly 100% faradic efficiency for the ethanol-to-acetate conversion in an alkaline electrolyte without the generation of detectable CO2, evidenced by in situ electrochemical infrared spectroscopy, nuclear magnetic resonance, and ion chromatography. The selective and CO2-free conversion offers a promising strategy through alcohol fuel cells for contributing comparable current density to power electrical equipment while for selective oxidation of biofuels to useful acetate intermediate for the chemical industry.
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Two naphthalene-containing compounds, 4-hydroxy-6,7-dimethoxy-1-(4-(trifluoromethyl)phenyl)-2-naphthoic acid (A) and 4-hydroxy-6,7-dimethoxy-1-phenyl-2-naphthoic acid (B), were prepared by several steps. Their bindings to human serum albumin (HSA) were studied by ultraviolet-visible (UV-vis) absorption, fluorescence, synchronous fluorescence, three-dimensional fluorescence, circular dichroism (CD) spectroscopies and molecular docking. The crystal data of these compounds show the structure of the compounds. The results show that the mechanism of the interaction between compound A and HSA is mixed-quenching (both dynamic and static quenching), while that of compound B and HSA is static quenching. The number of binding sites, binding constants and binding distance (r) were obtained. The interaction processes are spontaneous. A mainly interacts with HSA through typical hydrophobic interaction, and B binds to HSA mainly by the hydrogen bonds and van der Waals forces. The conformation of HSA changes slightly after the addition of the compounds. Besides, molecular docking method was used to study the interaction details between the compounds and HSA. This is helpful to understand the absorption and metabolism of these two compounds in the body, and provides a basis for designing naphthalene-containing drugs. Communicated by Ramaswamy H. Sarma.
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Naftalenos , Albumina Sérica Humana , Sítios de Ligação , Dicroísmo Circular , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica , Albumina Sérica Humana/metabolismo , Espectrometria de Fluorescência , TermodinâmicaRESUMO
(S)-N-methylpyrrolidine-2-carboxylate, a derivative of natural L-proline, was found to be an efficient ligand for the copper-catalyzed Goldberg-type N-arylation of amides with aryl halides under mild conditions. A variety of N-arylamides were synthesized in good to high yields.
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Amidas/química , Cobre/química , Prolina/análogos & derivados , Catálise , Ligantes , Espectroscopia de Ressonância Magnética , Prolina/química , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
In the title compound, [Cu(CH(3)COO)(2)(C(18)H(16)N(2)O(2))]·H(2)O, the Cu(II) ion is six-coordinated in a typically Jahn-Teller distorted octa-hedral environment defined by two O and two N atoms from the ligand and two O atoms from acetate anions. A linear chain structure propagating in [010] is built up by inter-molecular O-Hâ¯O hydrogen bonds involving the uncoordinated water mol-ecules.
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In the title compound, [Cu(CH(3)COO)(2)(C(18)H(16)N(2)O(2))]·4H(2)O, the Cu(II) ion is six-coordinated in a Jahn-Teller-distorted octa-hedral geometry environment defined by four O atoms and two N atoms. A chain structure along [100] is built up by inter-molecular O-Hâ¯O hydrogen bonds involving the uncoordinated water mol-ecules.
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The skeletons of both independent mol-ecules of the carboxylic acid hemihydrate, C(10)H(8)N(2)O(10)·0.5H(2)O, are approximately planar [maximum deviations 0.642â (3) and 0.468â (1)â Å]. The deviations arise from the twisting of the nitro groups with respect to the aromatic rings [dihedral angles = 3.24â (2) and 27.01â (1), and 7.87â (1) and 16.37â (2)° in the two molecules]. The crystal structure features inter-molecular O-Hâ¯O hydrogen bonds, which the link the dicarboxylic acid and water mol-ecules into a supra-molecular layer network.
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In the title compound, C(10)H(8)N(2)O(10)·2H(2)O, the skeleton of the dicarboxylic acid mol-ecule is approximately planar, the largest deviation being 0.477â (1)â Å for an O atom of a nitro group; this nitro group is twisted out of the plane of the ring by 24.6â (1)°. Adjacent mol-ecules are linked by O-Hâ¯O hydrogen bonds, which connect the dicarboxylic acid and water mol-ecules into a three-dimensional supra-molecular network.