Junior high school students’ perception of physical factors in the classroom based on the Online Q Method

 Students spend a lot of time in the classroom, and the physical environment in the classroom plays an important role in the development of students. It is necessary to scientifically investigate students' views and opinions on the physical factors in the classroom. Due to the COVID-19 pandemic, this study used the Q method online and allowed 40 junior high school students to rank 32 physical factors in the classrooms according to their own perspectives. The results can provide a reference for the reconstruction and construction of classrooms in middle schools and contribute to the design of learner-oriented humanized classrooms

Effect of Aged Wuyi Rock Tea on Relieving Dextran Sulfate Sodium-Induced Colitis and Regulating the Gut Microbiota in Mice

This research was performed in order to investigate the alleviative effect of aged Wuyi rock tea on dextran sulfate sodium (DSS)-induced colitis in mice. Fifty C57BL/6JGpt female mice were randomly and equally divided into five groups: control, DSS, DSS + infusion of 20-year-old Wuyi rock tea (DSS + OT01), DSS + infusion of 10-year-old Wuyi rock tea (DSS + OT11) and DSS + infusion of fresh Wuyi rock tea (DSS + OT20). The physiological and histopathological conditions of mice after Wuyi rock tea interventions, and the changes of serum inflammatory factors and cecal microbiota were analyzed. The results showed that aged Wuyi rock tea could significantly alleviate the symptoms of body mass loss, diarrhea, bloody stool, and colon length shortening, reduce inflammatory cell infiltration, and significantly inhibit the secretion of pro-inflammatory cytokines. In addition, aged Wuyi rock tea could alleviate the disorder of the gut microbiota, significantly down-regulate the relative abundance of Proteobacteria, Enterobacteriaceae and Escherichia, and up-regulate the relative abundance of Verrucomicrobia and Akkermansia. In summary, aged Wuyi rock tea can alleviate DSS-induced colitis in mice, and the tea produced in 2011 is more effective than that produced in 2001, which may be due to proper oxidation of catechins such as epigallocatechin gallate to produce thearubigins, with better anti-inflammatory and antioxidant properties. In addition, aged Wuyi rock tea is able to maintain intestinal homeostasis by regulating the relative abundance of Escherichia and Akkermansia in the intestine, which in turn alleviates the symptoms of DSS-induced colitis in mice such as body mass loss, diarrhea, bloody stool, colon length shortening, mucosal and crypt damage, inflammatory cell infiltration, and serum inflammatory factor overexpression

Multifaceted SlyD from Helicobacter pylori: implication in [NiFe] hydrogenase maturation

SlyD belongs to the FK506-binding protein (FKBP) family with both peptidylprolyl isomerase (PPIase) and chaperone activities, and is considered to be a ubiquitous cytosolic protein-folding facilitator in bacteria. It possesses a histidine- and cysteine-rich C-terminus binding to selected divalent metal ions (e.g., Ni2+, Zn2+), which is important for its involvement in the maturation processes of metalloenzymes. We have determined the solution structure of C-terminus-truncated SlyD from Helicobacter pylori (HpSlyDΔC). HpSlyDΔC folds into two well-separated, orientation-independent domains: the PPIase-active FKBP domain and the chaperone-active insert-in-flap (IF) domain. The FKBP domain consists of a four-stranded antiparallel β-sheet with an α-helix on one side, whereas the IF domain folds into a four-stranded antiparallel β-sheet accompanied by a short α-helix. Intact H. pylori SlyD binds both Ni2+ and Zn2+, with dissociation constants of 2.74 and 3.79 μM respectively. Intriguingly, binding of Ni2+ instead of Zn2+ induces protein conformational changes around the active sites of the FKBP domain, implicating a regulatory role of nickel. The twin-arginine translocation (Tat) signal peptide from the small subunit of [NiFe] hydrogenase (HydA) binds the protein at the IF domain. Nickel binding and the recognition of the Tat signal peptide by the protein suggest that SlyD participates in [NiFe] hydrogenase maturation processes

Metal-binding properties of an Hpn-like histidine-rich protein

The Hpn‐like protein (Hpnl), a histidine‐ and glutamine‐rich protein, is critical for Helicobacter pylori colonization in human gastric muscosa. In this study, the thermodynamic properties of NiII, CuII, CoII, and ZnII toward Hpnl were studied by isothermal titration calorimetry (ITC). We found that Hpnl exhibits two independent binding sites for NiII as opposed to one site for CuII, CoII, and ZnII. Protease digestion and chemical denaturation analysis further revealed that NiII confers a higher stability upon Hpnl than other divalent metal ions. The potential NiII binding sites are localized in the His‐rich domain of Hpnl as confirmed by mutagenesis in combination with modification of histidine residues of the protein. We also demonstrated that the single mutants (H29A and H31A) and tetrameric mutant (H29‐32A) cut nearly half of the binding capacity of Hpnl towards nickel ions, whereas other histidine residues (His30, 32, 38, 39, 40, and 41) are nonessential for nickel coordination. Escherichia coli cells that harbored H29A, H31A, and H29‐32A mutant genes exhibited less tolerance toward high concentrations of extracellular nickel ions than those with the wild‐type gene. Our combined data indicated that the conserved histidine residues, His29 and His31 in the His‐rich domain of Hpnl, are critical for nickel binding, and such a binding is important for Hpnl protein to fulfill its biological functions

Scalable risk assessment of large infrastructure systems with spatially correlated components

Risk assessment of spatially distributed infrastructure systems under natural hazards shall treat the performance of individual components as stochastically correlated due to the common engineering practice in the community including similarities in building design code, regulatory practices, construction materials, construction technologies, and the practices of local contractors. Modelling the spatially correlated damages of an infrastructure system with many components can be computationally expensive. This study addresses the scalability issue of risk analysis of large-scale systems by developing an interpolation technique. The basic idea is to sample a portion of components in the systems and evaluate their correlated damages accurately, while the damages of remaining components are interpolated from the sampled components. The new method can handle not only linear systems, but also systems with complex connectivity such as utility networks. Two examples are presented to demonstrate the proposed method, including cyclone loss assessment of the building portfolios in a virtual community, and connectivity analysis of an electric power system under a scenario cyclone event

Inhibition of urease by bismuth(III): Implications for the mechanism of action of bismuth drugs

Bismuth compounds are widely used for the treatment of peptic ulcers and Helicobacter pylori infections. It has been suggested that enzyme inhibition plays an important role in the antibacterial activity of bismuth towards this bacterium. Urease, an enzyme that converts urea into ammonia and carbonic acid, is crucial for colonization of the acidic environment of the stomach by H. pylori. Here, we show that three bismuth complexes exhibit distinct mechanisms of urease inhibition, with some differences dependent on the source of the enzyme. Bi(EDTA) and Bi(Cys)3 are competitive inhibitors of jack bean urease with K i values of 1.74 ± 0.14 and 1.84 ± 0.15 mM, while the anti-ulcer drug, ranitidine bismuth citrate (RBC) is a non-competitive inhibitor with a K i value of 1.17 ± 0.09 mM. A 13C NMR study showed that Bi(Cys)3 reacts with jack bean urease during a 30 min incubation, releasing free cysteines from the metal complex. Upon incubation with Bi(EDTA) and RBC, the number of accessible cysteine residues in the homohexameric plant enzyme decreased by 5.80 ± 0.17 and 11.94 ± 0.13, respectively, after 3 h of reaction with dithiobis(2-nitrobenzoic acid). Kinetic analysis showed that Bi(EDTA) is both a competitive inhibitor and a time-dependent inactivator of the recombinant Klebsiella aerogenes urease. The active C319A mutant of the bacterial enzyme displays a significantly reduced sensitivity toward inactivation by Bi(EDTA) compared with the wild-type enzyme, consistent with binding of Bi3+ to the active site cysteine (Cys319) as the mechanism of enzyme inactivation

Aged oolong tea manages type 2 diabetes mellitus by inhibiting fat ectopic deposition and alleviating insulin resistance in db/db mice

Abstract An important concern for tea consumers is whether appropriate storage can effectively improve the ability of oolong tea to alleviate type 2 diabetes mellitus (T2DM). In this study, the antidiabetic effects of three aged oolong tea (2001, 2011, and 2020) extracts (aged TEs) in db/db T2DM mice were investigated and compared for the first time. The results showed that aged oolong tea extracts (aged TEs) alleviated the abnormal fasting blood glucose levels, lipid profiles, insulin resistance, and reduced ectopic fat deposition in liver. Moreover, aged TEs alleviated T2DM‐related tissue damage and activated insulin receptor (INSR)/insulin receptor substrate (IRS)/phosphatidylinositol‐3 kinase (PI3K)/phosphatidylinositol‐3 kinase (AKT)/glycogen synthase kinase 3 beta (GSK‐3β)/glycogen synthase (GYS)‐mediated hepatic glycogen synthesis signaling pathway. In addition, aged TEs altered gut microbiota composition and gut metabolite profiles associated with T2DM. Together, all three aged TEs (400 mg/kg/day in mice, a human equivalent dose of 7 g/60 kg/day), especially 2011, can effectively alleviate T2DM, and proper storage can effectively improve the ability of oolong tea to alleviate T2DM