Microfluidic redox flow batteries (μRFBs) have emerged as promising membrane-free energy storage systems due to their enhanced mass transport characteristics and precise control of microscale fluid dynamics; however, their performance remains strongly constrained by electrolyte crossover and flow instability. Here, we systematically investigate the coupled effects of microchannel geometry, flow rate, and electrode spacing on the hydrodynamic and electrochemical behavior of a graphene-based μRFB employing a Zn/Mn redox couple. A three-dimensional computational fluid dynamics model was developed to analyze co-laminar flow and species transport within rectangular microchannels, revealing that channel dimensions and operating conditions critically govern micromixing, reactant utilization, and energy conversion efficiency. Excessive mixing, driven by longer residence times and specific channel aspect ratios, was found to accelerate electrolyte crossover and reduce electrochemical performance. Using a Taguchi design-of-experiments approach, an optimized microchannel geometry was identified and subsequently validated through fluorescence-based micromixing measurements. The electrode spacing plays a decisive role in device performance; although reducing the inter-electrode gap lowers ohmic resistance, excessively narrow spacing enhances cross-stream species transport and activation losses. The findings establish fundamental design principles for optimizing μRFB architectures and provide a robust framework for developing high-performance, scalable, and flexible microfluidic energy storage systems.
Architectural education requires students to integrate design thinking with technical knowledge, yet building construction and building component design courses are often structured around instructor-centered knowledge transmission in which technical information precedes and remains partially detached from design exploration. Although integrated, experiential, and problem-based approaches have sought to bridge this divide, less attention has been given to when formal technical instruction enters the design learning process and how this timing may shape students’ engagement with technical-design problems. This study proposes a phased and guided pedagogical framework that treats the timing of formal technical instruction as a deliberate instructional design variable in building construction education. The framework is organized through three successive stages: initial problem exploration, structured technical guidance, and the revision of initial design decisions following technical instruction. The framework is conceptually articulated through a stair and vertical circulation module within an undergraduate Building Component Design course, where spatial, ergonomic, regulatory, structural, and representational considerations must be addressed simultaneously. Traditional lecture-based, discovery-based, and phased and guided configurations are used as contrasting pedagogical structures to clarify differences in the sequencing of technical knowledge rather than to establish comparative performance outcomes. The proposed framework does not claim pedagogical superiority and has not yet been empirically validated. Instead, it provides a conceptual and methodological basis for future investigation of technical reasoning, design decision-making, reflective revision, and knowledge transfer. Its underlying sequence is intended to be adaptable across different building components and stages of architectural education, while also accommodating contemporary access to technical information through digital resources and generative AI.
Obesity is increasingly recognized as a condition with profound systemic and epigenetic consequences. However, the molecular mechanisms linking obesity to reproductive dysfunction remain incompletely understood. Accumulating evidence suggests that epigenetic regulation, particularly DNA methylation, contributes to and is modified by obesity, thereby influencing gene expression in gonadal tissues and germ cells. DNA methylation is essential for normal oogenesis and spermatogenesis and is mediated by DNA methyltransferases (DNMTs), whose expression and activity are tightly regulated throughout germ cell development. This review synthesizes current experimental and clinical evidence regarding obesity-associated alterations in DNMT expression and DNA methylation patterns across female and male reproductive systems and examines how these epigenetic disruptions contribute to infertility. Obesity is most frequently associated with a hypermethylated epigenetic landscape in female reproductive tissues, whereas the male germline more commonly exhibits global or locus-specific hypomethylation, reflecting sex-specific epigenetic responses to metabolic stress. Studies spanning ovarian tissue, oocytes, sperm, and early embryos demonstrate that obesity-induced DNMT dysregulation and DNA methylation remodeling disrupt transcriptional programs governing folliculogenesis, spermatogenesis, and embryo development.
In the search for novel antimicrobial agents, a series of aminated quinolinequinone derivatives (AQQ1-13) were synthesized and evaluated for their in vitro antibacterial and antifungal activities. These compounds were constructed via sulfonamide linkers incorporating commercially available p-aminobenzenesulfonamides bearing diverse heteroaromatic or acyl substituents. The antibacterial activity was assessed against four gram-negative and three gram-positive bacterial strains, while antifungal activity was evaluated against three fungal species using the CLSI-approved broth microdilution method. Several compounds demonstrated moderate antimicrobial activity when compared with standard reference drugs. Notably, three AQQs (AQQ7, AQQ9, and AQQ11) exhibited notable antibacterial activity against Enterococcus faecalis, with a minimum inhibitory concentration (MIC) value of 78.12 µg/mL, showing lower MIC values than amikacin under the tested conditions (MIC = 128 µg/mL) under the same conditions. Time-kill studies revealed bactericidal effects at 1× and 4× MIC levels, while combination studies demonstrated synergistic interactions with levofloxacin, particularly for AQQ11. Furthermore, AQQ9 and AQQ11 exhibited antibiofilm activity in combination therapy, including inhibition of biofilm formation and partial disruption of preformed biofilms. In silico ADMET and molecular docking analyses identified AQQ9 as a compound of interest, showing favorable drug-likeness properties and favourable binding interactions toward E. faecalis DNA gyrase. Overall, these findings highlight quinolinequinone-based sulfonamide bioisosteres as potential scaffolds for further development of combination therapies targeting gram-positive and biofilm-associated infections.
A series of aminated quinolonequinones (AQQ1-13) was synthesized from quinolinequinone and substituted aromatic amines containing a sulfonamide group with conformationally restricted heterocyclic structures or an acyl group. The obtained AQQs were characterized by various spectroscopic techniques including FTIR, NMR, and MS analyses. Structural modifications of the sulfonamide group in these compounds were selected by introducing various heterocyclic substituents, such as isoxazole, thiadiazole, pyridine, pyrimidine, pyrazine, and pyridazine, or by attaching acyl groups (acetyl or benzamide) with different substituents. Some of the synthesized AQQs exhibited antifungal activity against the tested strains, with potencies comparable to the reference drugs under the tested conditions. Noticeably, AQQ5 with thiadiazole moiety attached to the sulfonamide group showed inhibitory activity against C. albicans (MIC: 19.53 µg/mL). The most active compound AQQ5 also showed the best antifungal potency towards to other two fungi (C. parapsilosis and C. tropicalis). However, it should be noted that antifungal activity was evaluated only against ATCC strains. Considering the increasing prevalence of antifungal resistance, these results may not fully reflect the efficacy against clinical isolates. Antifungal resistance may render the antifungal activity already seen against ATCC strains ineffective in clinical isolates. Yet the putative target, farnesyl pyrophosphate synthase identified through in silico protocols suggests that farnesyl pyrophosphate synthase may be a potential target, warranting further experimental validation.
