97 research outputs found
Jordan product determined points in matrix algebras
Let be the algebra of all matrices over a unital commutative ring with 6 invertible. We say that is a Jordan product determined point if for every -module and every symmetric -bilinear map : the following two conditions are equivalent: (i) there exists a fixed element such that whenever , ; (ii) there exists an -linear map such that for all . In this paper, we mainly prove that all matrix units are Jordan product determined points in when . In addition, we get some corollaries by applying the main results
Enhanced electron transfer using NiCo2O4@C hollow nanocages with an electron-shuttle effect for efficient tetracycline degradation
Spinel oxides are recognized as promising Fenton-like catalysts for the
degradation of antibiotics. However, the catalytic performance is restrained by
the poor electron transfer rate (ETR). Herein, hollow NiCo2O4@C nanocages are
rationally designed and prepared to accelerate ETR in peroxymonosulfate (PMS)
activation for tetracycline (TC) degradation
Pyrimidine catabolism is required to prevent the accumulation of 5-methyluridine in RNA
5-Methylated cytosine is a frequent modification in eukaryotic RNA and DNA influencing mRNA stability and gene expression. Here we show that free 5-methylcytidine (5mC) and 5-methyl-2′-deoxycytidine are generated from nucleic acid turnover in Arabidopsis thaliana, and elucidate how these cytidines are degraded, which is unclear in eukaryotes. First CYTIDINE DEAMINASE produces 5-methyluridine (5mU) and thymidine which are subsequently hydrolyzed by NUCLEOSIDE HYDROLASE 1 (NSH1) to thymine and ribose or deoxyribose. Interestingly, far more thymine is generated from RNA than from DNA turnover, and most 5mU is directly released from RNA without a 5mC intermediate, since 5-methylated uridine (m5U) is an abundant RNA modification (m5U/U ∼1%) in Arabidopsis. We show that m5U is introduced mainly by tRNA-SPECIFIC METHYLTRANSFERASE 2A and 2B. Genetic disruption of 5mU degradation in the NSH1 mutant causes m5U to occur in mRNA and results in reduced seedling growth, which is aggravated by external 5mU supplementation, also leading to more m5U in all RNA species. Given the similarities between pyrimidine catabolism in plants, mammals and other eukaryotes, we hypothesize that the removal of 5mU is an important function of pyrimidine degradation in many organisms, which in plants serves to protect RNA from stochastic m5U modification
Exploring the mechanisms under Zuogui Pill’s treatment of ischemic stroke through network pharmacology and in vitro experimental verification
Due to its high mortality, incidence and disability rates, ischemic stroke poses heavy economic burdens to families and society. Zuogui Pill (ZGP) is a classic Chinese medicine for tonifying the kidney, which is effective for the recovery of neurological function after ischemic stroke. However, Zuogui Pill has not been evaluated for its potential effects on ischemic strokes. Using network pharmacology, the research aimed to explore the mechanisms of Zuogui Pill on ischemic stroke, which were further validated in SH-SY5Y cells injured by oxygen and glucose deprivation/reperfusion (OGD/R). Network analysis of Zuogui Pill identified 86 active ingredients and 107 compound-related targets correlated with ischemic stroke. Additionally, 11 core active compounds were obtained, such as Quercetin, beta sitosterol, and stigmasterol. Most of the compounds have been proven to have pharmacological activities. Based on pathway enrichment studies, Zuogui Pill may exert neuroprotection through MAPK signaling, PI3K-Akt signaling and apoptosis, as well as enhance neurite outgrowth and axonal regeneration effect via mTOR signaling, p53 signaling and Wnt signaling pathways. In vitro experiment, the viability of ischemic neuron treated with Zuogui Pill was increased, and the ability of neurite outgrowth was significantly improved. Western blot assays shown that the pro-neurite outgrowth effect of Zuogui Pill on ischemic stroke may be relate to PTEN/mTOR signal pathway. The results of the study provided new insights into Zuogui Pill’s molecular mechanism in treatment of ischemic stroke, as well as clinical references for its use
Study on the Flow Boiling Heat Transfer Characteristics of the Liquid Film in a Rotating Pipe
A three-dimensional numerical model is established to study the flow boiling heat transfer characteristics of the liquid film in a rotating pipe, and the effectiveness of the model is verified by a comparison between the numerical results and the experimental results. The effects of rotational speed, heat flux, and Coriolis force on the characteristics of heat transfer of the rotating liquid film are investigated. The conclusions are drawn as follows: (1) The convection of the rotating liquid film is enhanced while the nucleate boiling in the rotating liquid film is inhibited by the increase in the rotational speed; (2) With the influence of these two factors, the heat transfer coefficient increases with centrifugal acceleration increasing from 20 g to 40 g, then decreases with centrifugal acceleration increasing from 40 g to 120 g; (3) The turbulent intensity of the flow with Coriolis force is obviously increased compared to that without Coriolis force when the centrifugal acceleration ranges from 20 g to 80 g, which shows no increase at higher centrifugal accelerations when the turbulence is sufficiently strong. The Coriolis force also has an impact on the heat transfer coefficient of the liquid film, which should not be ignored when studying the boiling heat transfer of a rotating liquid film
Biorefinery methods for extraction of oil and protein from rubber seed
Abstract Rubber seeds are a by-product of rubber production and are rich in oil and protein. Upgrading of rubber seeds to produce proteins, oils and feedstock can generate additional revenue for rubber production and reduce waste. The present study investigates the effects of different pre-treatments and extraction methods to determine the optimal methods to produce oil and protein from rubber seed kernels. Mechanical expulsion using a screw press and solvent extraction using n-hexane were employed for oil separation. The highest oil recovery efficiency of 95.12% was obtained using rubber seed meal that was pre-dried at 105 ℃. The sequential water–alkaline treatment was ideal for achieving high protein recovery while reducing the protein denaturation that can result from high operating temperatures and organic solvent contact. Over 90% of the total protein from rubber seed kernels could be recovered. Separating oil from kernels using hexane followed by protein extraction from the meals by enzymatic treatment provides a suitable method for comprehensive utilization of rubber seeds
Two Novel Pyrene Tetra-Sulfonate Europium Coordination Polymers: Structure Formation Mechanism Analysis and Sequential Modulation Strategy
For the purpose of broadening the understanding of the sulfonic acid coordination mechanism, a coordination system consisting of Eu(III) ion and 1,3,6,8-pyrene tetra-sulfonate (1,3,6,8-PTS) ligand was chosen as the typical research object. By step regulating the volume ratio of mixed solvents and the molar ratio of metal salts to ligands, two pyrene tetra-sulfonate europium coordination polymers, Eu6(μ6-O)(μ3-OH)8(NO3)6(1,3,6,8-H2PTS)(H2O)10 (1) and Eu(NO3)(1,3,6,8-PTS)0.5(H2O)3·0.5bipy (2), were obtained in sequence. Compound 1 shows a 1D chain-like structure interconnected with 1,3,6,8-PTS bridging ligands and rare [Eu6(μ6-O)(μ3-OH)8(NO3)6]2+ cluster nodes, while compound 2 shows a 2D layered structure. Further structural comparison with compound Eu(1,3,6,8-PTS)(H2O)7·4H2O·Hbipy (EuPTSbp-1) was discussed in detail and the structure formation mechanism was analyzed. On this basis, a sequential modulation strategy for pyrene tetra-sulfonate europium coordination polymers was proposed
Two Novel Pyrene Tetra-Sulfonate Europium Coordination Polymers: Structure Formation Mechanism Analysis and Sequential Modulation Strategy
For the purpose of broadening the understanding of the sulfonic acid coordination mechanism, a coordination system consisting of Eu(III) ion and 1,3,6,8-pyrene tetra-sulfonate (1,3,6,8-PTS) ligand was chosen as the typical research object. By step regulating the volume ratio of mixed solvents and the molar ratio of metal salts to ligands, two pyrene tetra-sulfonate europium coordination polymers, Eu6(μ6-O)(μ3-OH)8(NO3)6(1,3,6,8-H2PTS)(H2O)10 (1) and Eu(NO3)(1,3,6,8-PTS)0.5(H2O)3·0.5bipy (2), were obtained in sequence. Compound 1 shows a 1D chain-like structure interconnected with 1,3,6,8-PTS bridging ligands and rare [Eu6(μ6-O)(μ3-OH)8(NO3)6]2+ cluster nodes, while compound 2 shows a 2D layered structure. Further structural comparison with compound Eu(1,3,6,8-PTS)(H2O)7·4H2O·Hbipy (EuPTSbp-1) was discussed in detail and the structure formation mechanism was analyzed. On this basis, a sequential modulation strategy for pyrene tetra-sulfonate europium coordination polymers was proposed
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Cu-based catalyst designs in CO2 electroreduction: precise modulation of reaction intermediates for high-value chemical generation.
The massive emission of excess greenhouse gases (mainly CO2) have an irreversible impact on the Earths ecology. Electrocatalytic CO2 reduction (ECR), a technique that utilizes renewable energy sources to create highly reduced chemicals (e.g. C2H4, C2H5OH), has attracted significant attention in the science community. Cu-based catalysts have emerged as promising candidates for ECR, particularly in producing multi-carbon products that hold substantial value in modern industries. The formation of multi-carbon products involves a range of transient intermediates, the behaviour of which critically influences the reaction pathway and product distribution. Consequently, achieving desirable products necessitates precise regulation of these intermediates. This review explores state-of-the-art designs of Cu-based catalysts, classified into three categories based on the different prospects of the intermediates modulation: heteroatom doping, morphological structure engineering, and local catalytic environment engineering. These catalyst designs enable efficient multi-carbon generation in ECR by effectively modulating reaction intermediates
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