Microalgae serve as a cell factory for sustainable biomass and high-value compound production, yet their industrial-scale cultivation is often constrained by light energy utilization. The continuous illumination often limits photosynthetic efficiency and biomass and high-value compound productivity due to a kinetic mismatch between rapid photochemical reactions (picosecond-to-millisecond scale) and slower downstream biochemical processes (like Calvin-Benson cycle). Flashing/pulsed light strategies mitigate these by delivering intermittent photons, exploiting the biological effects to enhance quantum yield, biomass productivity, and targeted metabolites accumulation. This mini review emphasizes historical development of core concepts, molecular mechanisms, Photosystem II (PSII) dynamics, plastoquinone buffering, temporal decoupling, parameter optimization, the applications in autotrophic and mixotrophic modes, and photobioreactor innovations. An updated timeline to date highlights the emerging AI-driven adaptive lighting systems that promise real-time optimization of flashing regimes. This review summarizes current understanding, critical knowledge gaps and future directions, particularly in intelligent control for scalable, energy-efficient cultivation of microalgae by the rational design of advanced photobioreactors and cultivation strategies.
Research into biodegradable polymers, driven by environmental imperatives, has progressed significantly. The copolymerization of CO2 and epoxides produces poly(propylene carbonate) (PPC), which exhibits favorable biodegradability but suffers from poor thermomechanical properties. To address this, recent studies have incorporated rigid monomers or crystalline segments into such copolymerizations, generating a diverse range of CO2-derived copolymers with enhanced thermal and mechanical performance. However, their degradation profiles remain insufficiently characterized. In this study, we selected several representative CO2-derived copolymers, recently synthesized by our group, to systematically investigate the structure-property relationship. We evaluated their biodegradability through a series of tests, including biodegradation rate analysis, compost disintegration, and seed germination assays. These polymers, developed by our research team, offer advantages such as low cost, tunable properties, broad applicability, and environmental compatibility. They are thus promising candidates for introducing new materials into the biodegradable plastics market.
This study presents a process design, simulation, and optimization framework for converting septic sludge into biomethane using Aspen Plus®. The sludge was characterized, revealing carbon, hydrogen, and volatile matter contents of 33.80, 5.86, and 34.86 wt.%, respectively. The developed Aspen Plus® model was validated against three literature datasets, achieving percentage errors below unity. Optimization using Response Surface Methodology-Central Composite Design (RSM-CCD) showed that the maximum biomethane yield was 58.227 vol% under optimal conditions: 25 °C hydrolysis temperature, 60 °C digester temperature, 35 days hydraulic retention time (HRT), and an organic loading rate (OLR) of kg·VS·m−3·day−1, with a desirability score of 1.0. A techno-economic evaluation using the Aspen Process Economic Analyser (APEA) demonstrated the system’s economic feasibility, with a total capital investment of USD 3.19 million, an annual operating cost of USD 1.29 million, and a payback period of approximately 3.8 years. The optimized system achieved a net energy gain of 82.6%, IRR of 16.6%, and NPV of $4.64 M, confirming strong economic viability. Sensitivity analysis further revealed that CAPEX, OPEX, feedstock cost, and upgrading energy demand significantly influence system profitability, emphasizing the importance of process optimization and energy-efficient upgrading strategies. Environmental assessment showed that the optimized system improved methane recovery efficiency to 98.7% and achieved a CO2 emission reduction potential of 0.49 kg CO2-eq/kg CH4, demonstrating strong greenhouse gas mitigation potential. Overall, the findings establish anaerobic digestion of septic sludge as a sustainable and cost-effective waste-to-energy pathway suitable for decentralized urban wastewater management, supporting circular economy and clean energy objectives in developing regions.
Cardiac fibrosis is a central pathological feature of heart failure and contributes to myocardial stiffening, impaired electrical conduction, and progressive ventricular dysfunction. Traditionally, fibrotic remodeling has been viewed as a fibroblast-driven process in which activated fibroblasts deposit excessive extracellular matrix following cardiac injury. However, emerging evidence indicates that fibrosis arises from coordinated interactions among multiple cardiac cell populations, including cardiomyocytes, endothelial cells, immune cells, pericytes, and fibroblasts. In this review, we discuss the role of cardiomyocytes and their interactions with other cell types in the heart in facilitating cardiac fibrosis. We discuss how interactions among cardiomyocytes, immune cells, endothelial cells, pericytes, and fibroblasts contribute to fibrotic remodeling in both ischemic and non-ischemic heart disease. Our signaling emphasis is on transforming growth factor-β (TGF-β)-mediated cardiac fibrosis in the context of cellular interplay. We posit that a better understanding of these integrated signaling networks may reveal new opportunities to prevent or reverse pathological cardiac fibrosis.
To address the difficulty of predicting plate heat exchanger performance under variable-flow and fouling-prone coastal conditions, this study developed a novel combined framework for a BR50 plate heat exchanger by integrating a steady-state heat transfer model with a transfer-function-based dynamic wall-temperature model. The main innovation is that the framework simultaneously captures steady thermal performance and transient wall-temperature response, while explicitly quantifying the coupled effects of flow velocity and kinematic viscosity. The model was evaluated for sewage-side velocities of 0.8–1.5 m/s and viscosities up to ten times that of clean water. Results show that wall temperature increases slightly with velocity and can be described by a fourth-order polynomial. Its transient response follows first-order inertia, and the time constant decreases as velocity increases, indicating faster thermal response at higher flow rates. Both the sewage-side heat transfer coefficient and the overall heat transfer coefficient increase with velocity but decrease with viscosity; increasing velocity from 0.8 to 1.5 m/s raises the sewage-side coefficient by 49.2%. Sensitivity analysis identifies kinematic viscosity as the dominant factor affecting thermal performance, followed by flow velocity and wall temperature. The framework provides a practical basis for seawater-source heat pumps and coastal heat recovery systems under fouling-influenced conditions.
