Direct Synthesis for Benzofuro[3,2-d]pyrimidin-2-Amines via One-Pot Cascade [4 + 2] Annulation/Aromatization between Benzofuran-Derived Azadienes and Carbodiimide Anions.

The chemoselective [4+2] annulation/aromatization reactions between benzofuran-derived azadienes and N-Ts cyanamides are developed, affording a convenient method for synthesizing benzofuro[3,2-d]pyrimidin-2-amines under mild conditions. Herein, N-Ts cyanamides selectively participated in reactions absolutely via carbodiimide anion intermediates and the corresponding cyanamide anion intermediates derived products were not observed. The proposed chemoselective stepwise reaction mechanism was well supported by DFT calculations.

The optimal dose of metformin to control conversion to diabetes in patients with prediabetes: A meta-analysis.

AIM: This study aims to investigate the optimal dose of metformin for controlling the transition to diabetes in patients diagnosed with prediabetes. METHODS: We systematically searched randomized controlled trials (RCTs) in CNKI, Wanfang, VIP, SinoMed, Scopus, PubMed, Embase, Cochrane Library, Web of Science, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) from inception to February 2024. Meta-analysis was conducted using RevMan 5.4 software. RESULTS: We included 25 randomized controlled trials comprising 2437 patients. The results of the meta-analysis revealed that compared to dose groups of 500 mg/d, 850 mg/d, 1000 mg/d, 1500 mg/d, 1700 mg/d, and 2000 mg/d, a dosage of 750 mg/d of metformin significantly reduced the incidence of diabetes in patients (risk ratio [RR] = 0.21, 95 % confidence interval [CI]: 0.11, 0.41; p < 0.00001), lowered Postprandial Blood Glucose (PBG) (mean difference[MD] = -2.60, 95 % CI: -4.34, -0.86; p = 0.003), and promoted the normalization of blood glucose levels (RR = 2.13, 95 % CI: 1.68, 2.71; p < 0.00001). Regarding safety evaluation, no significant differences were identified among the various dose groups. In contrast, the cohort receiving a daily dosage of 750 mg demonstrated the most pronounced decrease in the incidence of adverse reactions. CONCLUSION: Based on the efficacy and safety evaluation results, our findings suggest that a daily dosage of 750 mg of metformin may represent the optimal dose for controlling the progression from pre-diabetes to diabetes. REGISTRATION: PROSPERO registration ID: CRD42024538322.

Iron Species-Supporting Hydrophobic and Nonswellable Polytetrafluoroethylene/Poly(acrylic acid-co-hydroxyethyl methacrylate) Composite Fiber and Its Stable Catalytic Activity for Methylene Blue Oxidative Decolorization.

Polytetrafluoroethylene emulsion was ultrasonically mixed with an extremely spinnable poly(acrylic acid-co-hydroxyethyl methacrylate) solution to get a dispersion with good spinnability, and the obtained dispersion was then wet-spun into water-swellable fiber. Crosslinking agents and iron species were simultaneously introduced into the water-swellable fiber through simple impregnation and water swelling. A composite fiber with Fenton reaction-catalyzing function was then fabricated by sequentially conducting crosslinking and sintering treatment. Due to crosslinking-induced good resistance to water swelling and PTFE component-induced hydrophobicity, the composite fiber showed a highly stable activity to catalyze H2O2 to oxidatively decolorize methylene blue (MB). Within nine cycles, the composite fiber could decolorize more than 90% of MB within one minute in the presence of H2O2 and did not show any attenuation in MB decolorization efficiency. The composite fiber still could reduce the total organic carbon of MB aqueous solution from 18.3 to 10.3 mg/L when used for the ninth time. Therefore, it is believable that the prepared fiber has good and broad application prospects in the field of dye wastewater treatment.

Highly efficient catalytic properties of Sc and Fe single atoms stabilized on a honeycomb borophene/Al(111) heterostructure via a dual charge transfer effect.

Theoretical design and experimental fabrication of highly efficient single-atom catalysts (SACs) containing isolated metal atoms monodispersed on appropriate substrates have surged to the forefront of heterogeneous catalysis in recent years. Nevertheless, the instability of SACs, i.e., preferential clustering in chemical reaction processes, dramatically hinders their practical applications. In this paper, using first-principles calculations, we predict that a honeycomb borophene/Al(111) heterostructure can be an ideal candidate to stabilize and enhance the catalysis of many transition metal (TM) SACs via a dual charge transfer mechanism. The Al(111) substrate donates electrons to the pre-covered two-dimensional honeycomb borophene (h-B) to stabilize the latter, and the deposited TM atoms further provide electrons to the h-B, enhancing the covalent binding between the h-B and the Al(111) substrate. Intriguingly, during CO oxidation, the h-B/Al(111) heterostructure can in turn serve as an efficient electron reservoir to accept electrons from or donate electrons to the deposited TM-SACs and the reactants. Such a flexible dual charge transfer mechanism not only facilitates stabilizing the TM-SACs rather than clustering, but also effectively reduces the reaction barriers. Particularly, in contrast to expensive noble metal atoms such as Pd and Pt, low-cost Sc- and Fe-SACs are found to be the most promising SAC candidates that can be stabilized on h-B/Al(111) for O2 activation and CO oxidation, with fairly low reaction barriers (around 0.50-0.65 eV). The present findings may provide important theoretical guidance for the experimental fabrication of highly stable, efficient, and economic SACs stabilized on various heterostructure substrates.

Cloning and analysis of human Apg16L.

Autophagy is an intracellular bulk degradation system, which delivers cytoplasmic components to the lysosome/vacuole. In yeast and mammalian cells, the Apg12-Apg5 conjugate, together with Apg16, form a multimeric complex, which plays an essential role in autopihageosome formation. By large-scale sequencing analysis of a human fetal brain cDNA library, we isolated a cDNA encoding a putative protein with 607 amino acid residues, which shows 90% identity and 93% similarity to mouse Apg16L. This protein, designated human Apg16L, contains a coiled-coil domain and a motif with seven WD repeats, which are also shared by mouse Apg16L. Database searching revealed that Apg16L is mapped to chromosome 2q37.1 and there exist at least four splice variants.