Browse Articles

A novel factorial design implemented spectrofluorimetric determination of caffeic acid: individual and combined assays with curcumin

Abstract In this research, we developed, for the first time, sensitive, selective, and reliable spectrofluorimetric methods for the quantitative analysis of caffeic acid (CAF) alone and in combination with curcumin (CUR). Two fluorimetric methods were established for the determination of CAF alone; a native fluorescence method (Method I) was optimized using 2 3 factorial model, exploiting the compound’s intrinsic fluorescence properties. The excitation and emission wavelengths were set at λex/λem = [324/443] nm. For the simultaneous analysis of CAF and CUR, the synchronous fluorescence (SF) technique was employed (Method II). The constant wavelength difference was optimized at 100 nm, allowing the simultaneous quantification of both analytes in a single measurement without prior separation. Under optimized conditions, the native fluorescence method for CAF alone showed a linear range of 30.0–800.0 ng/mL with a lower detection limit of 9.44 ng/mL. The SF method for the mixture demonstrated linear ranges of 50.0-2000.0 ng/mL for CAF and 20.0-200.0 ng/mL for CUR, with LOD values of 15.40 and 5.94 ng/mL, respectively. Both methods were successfully validated according to ICH guidelines, demonstrating excellent accuracy, precision, and robustness. The proposed methods were applied to different matrices, including green tea (method I), synthetic mixtures, and spiked human plasma (methods I and II). The ecological impact of the proposed methods was investigated. They provide a simple, cost-effective, and green alternative to chromatographic techniques for the routine quality control of caffeic acid and curcumin.

Robust self-assembled monolayer enables ultraviolet stable perovskite photovoltaics

Semiconductor Superlattice with Remarkable Raman Enhancement for Ultrafast Culture-Free Sensing of Multiple Pathogens

Decision-making, regret, and quality of life in living organ donors: a cross-sectional study

Persistent paramagnons in high-temperature infinite-layer nickelate superconductors

Abstract The recent discovery of high-temperature superconductivity in hole-doped SmNiO 2 , exhibiting the record-high transition temperature T c among infinite-layer (IL) nickelates, has opened a new avenue for exploring design principles of superconductivity. Experimentally determining the electronic structure and magnetic interactions in this new system is crucial to elucidating the mechanism behind the enhanced superconductivity. Here, we report a Ni L -edge resonant inelastic x-ray scattering (RIXS) study of superconducting Sm-based IL nickelate thin films Sm 1− x − y Eu x Ca y NiO 2 (SECNO). Dispersive paramagnonic excitations are observed in both optimally and overdoped SECNO samples, supporting a spin-fluctuation-mediated pairing scenario. However, despite the two-fold enhancement of T c in the Sm-based nickelates compared to their Pr-based counterparts, the effective exchange coupling strength is reduced by approximately 20%. This behavior contrasts with hole-doped cuprates, where magnetic interactions correlate positively with T c , highlighting essential differences in their superconducting mechanisms.

Proximity-Induced Phosphatase-Recruiting DNA Feedback Switch for Self-Adaptive Modulation of Receptor Signaling and Cell Behavior

Network security situation prediction method based on KG and Parsimonious memory unit

RiPP recognition elements evolved to prevent pathway interference through leader peptide discrimination

Abstract Ribosomally synthesized and post-translationally modified peptides (RiPPs) are natural products with diverse structures and functions. Here, we report the discovery of a family of RiPPs whose biosynthetic gene clusters are widespread in the Bacillota genomes and often co-localize with those of lasso peptides, another distinct family of RiPPs. The synthesis of both kinds of RiPPs relies on specific interactions between small adapter protein domains known as RiPP recognition elements (RREs) with their precursor peptides. As these latter share a conserved RRE-binding motif, conflicts between the two biosynthetic pathways may emerge. Through biochemical and structural studies, we reveal how the two RiPP biosynthetic systems evolved to discriminate between their cognate precursors and leader peptidases, allowing them to coexist within a single host. Thus, our study provides insights into the evolutionary diversification of RiPP families.

Multifunctional Molecular Cages Boost Acidic CO ₂ Electroreduction to Ethylene

Examining the daily experiences of parents caring for children with rare neurogenetic conditions using over 18,000 ecological momentary assessments

Dynamic regulation of origin firing factors links CDK activity to dormant origin activation

Multifunctional Chloride-Oxide Additive Enabling Simultaneous Ionic/Electronic Conduction for High-Rate All-Solid-State NCM Cathodes

Three Fundamental Neurophysiological Features of Neural Dynamics: Aperiodic, Waveform, and Transient

Impact of mucilage incorporation into xanthan gum on the physical and textural characteristics of gluten-free bread during short-term storage

Selective deoxygenative bis- and monoborylation of carboxylic esters via boryloxy chromium–carbenes

Ultrafine Nanoporous Ordered High-Entropy Intermetallics with Isolated Multisites toward Electrocatalytic Aldehyde Hydrogenation

Selective elimination of amyloid-β–induced senescent neuroblastoma cells by Moringa oleifera leaf extract

Cholecystokinin input from the anterior cingulate cortex to the lateral periaqueductal gray mediates nocebo pain behavior in mice

Characterisation of Kothea flammea gen. nov., sp. nov., a planctomycete of the family Pirellulaceae isolated from Fjord Schlei in the Baltic Sea

Abstract The flame-like reddish to orange-pigmented planctomycetal strain SH139 T was isolated from brackish water obtained from Fjord Schlei in Northern Germany as part of an isolation effort led by Heinz Schlesner at Kiel University between the 1980s and early 2000s. Single gene- and whole genome-based analyses employing five established phylogenetic markers indicate that the novel isolate constitutes a novel genus and species within the family Pirellulaceae in the phylum Planctomycetota . The strain is aerobic, heterotrophic, mesophilic, and exhibits neutrophilic to slight alkaliphilic properties. Its genome size and DNA G + C content of 7.8 Mb and 55.8%, respectively, are comparable to the current closest relatives. The results of the phenotypic and phylogenetic analyses are supported by comprehensive comparative genomic data, including pangenome reconstruction and profiling of carbohydrate-active enzymes and biosynthetic gene clusters. We thus introduce Kothea flammea gen. nov., sp. nov., that is constituted by the here characterized isolate SH139 T (= KCTC 102020 T  = DSM 116129 T ) as type strain. The novel genus is named after Prof. Erika Kothe (Friedrich Schiller University Jena, Germany) in recognition of her pioneering work on microbial communication.

NN-xTB: density functional accuracy at semi empirical speed with neural network extended tight binding