225 research outputs found
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Mechanism of Exact Transition between Cationic and Anionic Redox Activities in Cathode Material Li2FeSiO4.
The discovery of anion redox activity is promising for boosting the capacity of lithium ion battery (LIB) cathodes. However, fundamental understanding of the mechanisms that trigger the anionic redox is still lacking. Here, using hybrid density functional study combined with experimental soft X-ray absorption spectroscopy (sXAS) measurements, we unambiguously proved that Li(2- x)FeSiO4 performs sequent cationic and anionic redox activity through delithiation. Specifically, Fe2+ is oxidized to Fe3+ during the first Li ion extraction per formula unit (f.u.), while the second Li ion extraction triggered the oxygen redox exclusively. Cationic and anionic redox result in electron and hole polaron states, respectively, explaining the poor conductivity of Li(2- x)FeSiO4 noted by previous experiments. In contrast, other cathode materials in this family exhibit diversity of the redox process. Li2MnSiO4 shows double cationic redox (Mn2+-Mn4+) during the whole delithiation, while Li2CoSiO4 shows simultaneous cationic and anionic redox. The present finding not only provides new insights into the oxygen redox activity in polyanionic compounds for rechargeable batteries but also sheds light on the future design of high-capacity rechargeable batteries
Numerical analysis of circular and square concrete filled aluminum tubes under axial compression
In this paper, the finite element (FE) method was used to investigate the axial compressive behaviors of circular and square concrete filled aluminum tubes (CFAT). Firstly, the simulation results were compared with the experimental results and the accuracy of the proposed FE model was verified. On this basis, the FE model was further applied to compare the mechanical properties of both circular and square CFATs under axial compression. It was found that the circular CFATs have a better effect on restraining the core concrete than square CFATs. The parametric analysis was also conducted based on the proposed FE model. It was noticed that the mechanical differences of the two kinds of CFATs gradually decreased with the increase of the aluminum ratio, aluminum strength and concrete strength
Effect of Soaking Time on the Quality of Soymilk and Their Correlation Analysis
The effects of soybean soaking time (6, 8, 10, 12, 14, 16 h) on the physicochemical properties and sensory quality of soymilk were studied, which provided theoretical support for the selection of soybean soaking time. Soybean moisture content and distribution, soluble protein content, solid content, particle size, viscosity, stability and sensory score were used as indicators to analyze the influence of soaking time on the quality of soymilk and determine the optimal soaking time of soybean. The relationships between soaking time, soybean moisture composition and soymilk quality were analyzed by using the Pearson's correlation method. The results of low-field NMR showed that with the increase of soaking time, the signal values of T21, T22 and T23 increased, and the proportion of adsorbed water increased. The soybean moisture reached saturation after 12 h soaking. The results of the quality study showed that with the increase of soaking time, the protein transfer rate, the average particle size at volume and viscosity of soymilk had a trend of increasing first and then decreasing. The total solids content decreased significantly (P<0.05), and soymilk stability decreased first and then increased. The sensory comprehensive score first increased and then decreased, with the highest score of 1.0466 after 8 h soaking, followed by 10 h soaking. Based on the above results, 8 h was chosen as the best soaking time for soybeans to make soymilk. Despite the viscosity, the taste score and the brightness value were low after 8 h soaking, the soluble protein content was the highest, which was 0.905 g/100 g, and the protein transfer rate reached 16.61%. The total solids content was 3.185 g/100 g after 8 h soaking, which was second only to 6 h of soaking. Meanwhile, b value was the lowest, and the sensory comprehensive evaluation value was the highest after 8 h soaking. The correlation analysis results showed that the soaking time was significantly negatively correlated with the proportion of soybean bound water and free water, and significantly positively correlated with the proportion of adsorbed water (r=−0.9638, −0.8241, 0.9391). The quality index of soymilk was affected by the soaking time, which was significantly negatively correlated with the soluble protein, the total solids content and the L value, and significantly positively correlated with a value (r=−0.9122, −0.9726, −0.8238, 0.9385)
Risk factors for symptomatic rotator cuff tears: a retrospective case–control study
BackgroundThe incidence and diagnostic rate of rotator cuff tears (RCTs) have increased significantly. The purpose of this study was to investigate and analyze the risk factors for symptomatic RCTs to provide a basis for their prevention and treatment.MethodsWe retrospectively analyzed the relevant clinical indicators of 193 patients with RCTs and 161 patients without RCTs hospitalized with shoulder pain as the main complaint from January 1, 2017, to August 31, 2021. Univariate analysis and multivariate logistic regression analysis were used to analyze the differences in potential risk factors between the two groups.ResultsUnivariate analysis revealed that age (p < 0.001), body mass index (BMI) (p = 0.036), hypertension (p < 0.001), coronary heart disease (p = 0.028), history of shoulder trauma (p < 0.001), hyperlipidemia (p = 0.025), type III acromion (p = 0.012) and critical shoulder angle (CSA) (p < 0.001) increased the risk of RCTs. Multivariate logistic regression analysis revealed that age ≥ 60 years (OR = 2.61, 95% CI = 1.23 to 5.12), CSA ≥ 35° (OR = 4.24, 95% CI = 1.60 to 11.22), hypertension (OR = 2.34, 95% CI = 1.33 to 4.11) and history of shoulder trauma (OR = 5.20, 95% CI = 2.87 to 9.45) were independent risk factors for symptomatic RCTs.ConclusionThe results of this study showed that age ≥ 60 years, CSA ≥35°, hypertension and history of shoulder trauma are independent risk factors for symptomatic RCTs and can provide directions for further development of prevention and treatment strategies. Future studies need to clarify the mechanism underlying the association between these risk factors and symptomatic RCTs
Extracting the Quantum Geometric Tensor of an Optical Raman Lattice by Bloch State Tomography
In Hilbert space, the geometry of the quantum state is identified by the
quantum geometric tensor (QGT), whose imaginary part is the Berry curvature and
real part is the quantum metric tensor. Here, we propose and experimentally
implement a complete Bloch state tomography to directly measure eigenfunction
of an optical Raman lattice for ultracold atoms. Through the measured
eigenfunction, the distribution of the complete QGT in the Brillouin zone is
reconstructed, with which the topological invariants are extracted by the Berry
curvature and the distances of quantum states in momentum space are measured by
the quantum metric tensor. Further, we experimentally test a predicted
inequality between the Berry curvature and quantum metric tensor, which reveals
a deep connection between topology and geometry
Identification of altered metabolic functional components using metabolomics to analyze the different ages of fruiting bodies of Sanghuangporus vaninii cultivated on cut log substrates
Sanghuangporus vaninii is a profitable traditional and medicinal edible fungus with uncommon therapeutic properties and medicinal value. The accumulation of active ingredients in this fungus that is used in traditional Chinese medicine is affected by its years of growth, and their pharmacological activities are also affected. However, the effects of age on the medicinal value of fruiting bodies of S. vaninii cultivated on cut log substrate remain unclear. In this study, an untargeted liquid chromatography mass spectrometry (LC-MS)-based metabolomics approach was performed to characterize the profiles of metabolites from 1-, 2- and 3-year-old fruiting bodies of S. vaninii. A total of, 156 differentially accumulated metabolites (DAMs) were screened based on the criterion of a variable importance projection greater than 1.0 and p < 0.01, including 75% up regulated and 25% down regulated. The results of enrichment of metabolic pathways showed that the metabolites involved the biosynthesis of plant secondary metabolites, biosynthesis of amino acids, central carbon metabolism in cancer, steroid hormone biosynthesis, linoleic acid metabolism, prolactin signaling pathway, and arginine biosynthesis, and so on. The biosynthesis of plant secondary metabolites pathway was significantly activated. Five metabolites were significantly elevated within the growth of fruiting bodies, including 15-keto-prostaglandin F2a, (4S, 5R)-4,5,6-trihydroxy-2-iminohexanoate, adenylsuccinic acid, piplartine, and chenodeoxycholic acid. 15-keto-prostaglandin F2a is related to the pathway of arachidonic acid metabolism and was significantly increased up to 1,320- and 535-fold in the 2- and 3-year-old fruiting bodies, respectively, compared with those in the 1-year-old group. The presence of these bioactive natural products in S. vaninii is consistent with the traditional use of Sanghuang, which prompted an exploration of its use as a source of natural prostaglandin in the form of foods and nutraceuticals. These findings may provide insight into the functional components of S. vaninii to develop therapeutic strategies
Heterologous expression of a Glyoxalase I gene from sugarcane confers tolerance to several environmental stresses in bacteria
Glyoxalase I belongs to the glyoxalase system that detoxifies methylglyoxal (MG), a cytotoxic by-product produced mainly from triose phosphates. The concentration of MG increases rapidly under stress conditions. In this study, a novel glyoxalase I gene, designated as SoGloI was identified from sugarcane. SoGloI had a size of 1,091 bp with one open reading frame (ORF) of 885 bp encoding a protein of 294 amino acids. SoGloI was predicted as a Ni2+-dependent GLOI protein with two typical glyoxalase domains at positions 28–149 and 159–283, respectively. SoGloI was cloned into an expression plasmid vector, and the Trx-His-S-tag SoGloI protein produced in Escherichia coli was about 51 kDa. The recombinant E. coli cells expressing SoGloI compared to the control grew faster and tolerated higher concentrations of NaCl, CuCl2, CdCl2, or ZnSO4. SoGloI ubiquitously expressed in various sugarcane tissues. The expression was up-regulated under the treatments of NaCl, CuCl2, CdCl2, ZnSO4 and abscisic acid (ABA), or under simulated biotic stress conditions upon exposure to salicylic acid (SA) and methyl jasmonate (MeJA). SoGloI activity steadily increased when sugarcane was subjected to NaCl, CuCl2, CdCl2, or ZnSO4 treatments. Sub-cellular observations indicated that the SoGloI protein was located in both cytosol and nucleus. These results suggest that the SoGloI gene may play an important role in sugarcane’s response to various biotic and abiotic stresses
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