Accurate identification of 8-oxoguanine in RNA with single-nucleotide resolution using ligase-dependent qPCR.

8-oxoguanine (o8G), a prevalent oxidative modification in RNA induced by reactive oxygen species (ROS), plays a pivotal role in regulating RNA functions. Accurate detection and quantification of o8G modifications is critical to understanding their biological significance and potential as disease biomarkers, but effective detection methods remain limited. Here, we have developed a highly specific T3 DNA ligase-dependent qPCR assay that exploits the enzyme's ability to discriminate o8G from guanine (G) with single-nucleotide resolution. This method can detect o8G in RNA at levels as low as 500 fM, with an up to 18-fold higher selectivity for discriminating o8G from G. By simulating oxidative stress conditions in SH-SY5Y and HS683 cell lines treated with rotenone, we successfully identified site-specific o8G modifications in key miRNAs associated with neuroprotective responses, including miR-124, let-7a and miR-29a. The developed assay holds significant promise for the practical identification of o8G, facilitating its potential for detailed studies of o8G dynamics in various biological contexts and diseases.

Fabrication of antimicrobial packaging based on polyaminopropyl biguanide incorporated pectin/polyvinyl alcohol films for fruit preservation.

Pectin (PEC)/polyvinyl alcohol (PVA), plasticizers, and polyaminopropyl biguanide (Pb) (0.125%-1%) were used to prepare the film solution. The results demonstrated significantly enhanced tensile strength and elongation at break of PEC/PVA/Pb 0.25% film than PEC/PVA film. Scanning electron microscopy was carried out to investigate the continuous and dense structure of the PEC/PVA/ Pb0.25% film. FTIR, XPS, and XRD revealed that Pb addition to the PEC/PVA film matrix changed its physicochemical properties by forming new hydrogen and CN bonds. Moreover, the composite films exhibited strong antimicrobial activity against food-borne microorganisms (E. coli and S. aureus), and post-harvest pathogens (P. italicum and F. proliferatum) in vitro. The composite film effectively inhibited P. italicum growth during citrus experiments, while maintaining nutritional components (vitamin C, total flavonoid, and total polyphenol content). Overall, the antimicrobial composite film presented promising applicability in food packaging.

Cooperation between the Cu+ and Cu2+ species in CuCoAl layered double hydroxide and the substrate promoting effect afford a really simple protocol for the efficient synthesis of quinazolines.

In this study, a really simple and efficient catalytic protocol for the construction of quinazolines from alcohol and diamine has been developed based on CuCoAl layered double hydroxide (CuCoAl-LDH). The developed CuCoAl-LDH catalyst could accelerate the cascade reactions without any additives and tolerate various alcohols with satisfactory yields. Cooperation between the Cu+ and Cu2+ species in CuCoAl-LDH was observed in the cascade reaction, and they are believed to be responsible for the oxidation of alcohol and dehydrogenation of the intermediate, respectively. The promoting effect of the substrate diamine was observed in the oxidation of alcohol, which simplifies the reaction system by eliminating the requirement for a base additive. The catalytic system exhibited highly practical potential for the synthesis of quinazolines, as demonstrated through recyclability investigations and scale-up experiments. A possible catalytic mechanism has been proposed based on a series of control experiments and EPR analysis.

The role of hydrogen-rich water in delaying the pulp breakdown of litchi fruit during postharvest storage.

Previous studies have indicated that hydrogen-rich water (HW) treatment can delay fruit ripening and senescence. However, little is known about the HW-delaying pulp breakdown. In this study, eight physiological characteristics revealed that HW treatment delayed both pericarp browning and pulp breakdown of litchi fruit. To gain a comprehensive understanding of the changes in litchi pulp, a combination of multiple metabolomics and gene expression analyses was conducted, assessing 67 primary metabolites, 103 volatiles, 31 amino acids, and 13 crucial metabolite-related genes. Results showed that HW treatment promoted starch degradation, decelerated cell wall degradation and glycolysis, and maintained the flavor and quality of litchi fruit. Furthermore, HW treatment stimulated the production of volatile alcohols, aldehydes, ketones, olefins, and amino acids, which might play a vital role in HW-delaying pulp breakdown. This study sheds light on the mechanism by which HW delayed pulp breakdown by investigating small molecule metabolites and metabolic pathways.

Ionic liquid post-modified carboxylate-rich MOFs for efficient catalytic CO2 cycloaddition under solvent-free conditions.

The synthesis of cyclic carbonates through cycloaddition reactions between epoxides and carbon dioxide (CO2) is an important industrial process. Metal-Organic Frameworks (MOFs) have functional and ordered pore structures, making them attractive catalysts for converting gas molecules into valuable products. One approach to enhance the catalytic activity of MOFs in CO2 cycloaddition reactions is to create open metal sites within MOFs. In this study, the amino-functionalized rare earth Gd-MOF (Gd-TPTC-NH2) and its ionic liquid composite catalysts (Gd-TPTC-NH-[BMIM]Br) were synthesized using 2'-amino-[1,1':4',1''-terphenyl]-3,3'',5,5''-tetracarboxylic acid (H4TPTC-NH2) as the ligand. The catalytic performance of these two catalysts was observed in the cycloaddition reaction of CO2 and epoxides. Under the optimized reaction conditions, Gd-TPTC-NH-[BMIM]Br can effectively catalyze the cycloaddition reaction of a variety of epoxide substrates with good to excellent yields of cyclic carbonate products. Comparatively, epichlorohydrin and epibromohydrin, which possess halogen substituents, promote higher yields of cyclic carbonates due to the electron-withdrawing nature of Cl and Br substituents. Additionally, the Gd-TPTC-NH-[BMIM]Br catalyst demonstrated good recyclability and reproducibility, maintaining its catalytic activity without any changes in its structure or properties after five reuse cycles.

Metal-Organic Frameworks-Derived Nanocarbon Materials and Nanometal Oxides for Photocatalytic Applications.

Harnessing low-density solar energy and converting it into high-density chemical energy through photocatalysis has emerged as a promising avenue for the production of chemicals and remediation of environmental pollution, which contributes to alleviating the overreliance on fossil fuels. In recent years, metal-organic frameworks (MOFs) have gained widespread application in the field of photocatalysis due to their photostability, tunable structures, and responsiveness in the visible light range. However, most MOFs exhibit relatively low response to light, limiting their practical applications. MOFs-derived nanomaterials not only retain the inherent advantages of pristine MOFs but also show enhanced light adsorption and responsiveness. This review categorizes and summarizes MOFs-derived nanomaterials, including nanocarbons and nanometal oxides, providing representative examples for the synthetic strategies of each category. Subsequently, the recent research progress on MOFs-derived materials in photocatalytic applications are systematically introduced, specifically in the areas of photocatalytic water splitting to H2, photocatalytic CO2 reduction, and photocatalytic water treatment. The corresponding mechanisms involved in each photocatalytic reaction are elaborated in detail. Finally, the review discusses the challenges and further directions faced by MOFs-derived nanomaterials in the field of photocatalysis, highlighting their potential role in advancing sustainable energy production and environmental remediation.

Constructing Lanthanide-Organic Complexes for X-ray Scintillation and Imaging.

The photoluminescent properties of lanthanide complexes have been thoroughly investigated; however, there have been much fewer studies showcasing their potential use in ionizing radiation detection. In this work, we delve into the photo- and radio-induced luminescence of a series of lanthanide-bearing organic-inorganic hybrids and their potential as a platform for X-ray scintillation and imaging. The judicious synergy between lanthanide cations and 2,6-di(1H-pyrazol-1-yl)isonicotinate (bppCOO-) ligands affords six new materials with three distinct structures. Notably, Eu-bppCOO-1 and Tb-bppCOO-2 display sharp fingerprint X-ray-excited luminescence (XEL), the intensities of which can be linearly correlated with the X-ray dose rates over a broad dynamic range (0.007-4.55 mGy s-1). Moreover, the X-ray sensing efficacies of Eu-bppCOO-1 and Tb-bppCOO-2 were evaluated, showing that Tb-bppCOO-2 features a lower detection limit of 4.06 µGy s-1 compared to 14.55 µGy s-1 of Eu-bppCOO-1. Given the higher X-ray sensitivity and excellent radiation stability of Tb-bppCOO-2, we fabricated a flexible scintillator film for X-ray imaging by embedding finely ground Tb-bppCOO-2 in the polydimethylsiloxane (PDMS) polymer. The resulting scintillator film can be utilized for high-resolution X-ray imaging with a spatial resolution of approximately 7 lp mm-1.