东北林业大学

Tissue repair is a highly coordinated process, yet dysregulated fibrosis often diverts healing toward scar formation, resulting in permanent structural and functional impairment. Achieving scarless regeneration requires precise modulation of the wound microenvironment to support functional tissue reconstruction. Hydrogels, owing to their biocompatibility, tunable mechanics, and controllable delivery capabilities, have emerged as promising platforms for regenerative therapy. Recent multifunctional hydrogels can regulate tissue repair through microstructural engineering, mechanical modulation, immune regulation, pro-angiogenic stimulation, and dynamic extracellular matrix remodeling, thereby suppressing fibrotic progression. However, current reviews mainly focus on accelerating wound closure and lack systematic discussion of antifibrotic hydrogel design across different tissues. In this review, we summarize the key mechanisms underlying scar formation and propose design principles for hydrogel-mediated scarless regeneration. We further highlight recent advances in multiple tissues, including skin, tendon, cornea, urethra, nerve, endometrium, liver, myocardium, emphasizing both shared principles and tissue-specific requirements. Finally, we discuss translational challenges and future opportunities, particularly AI-driven hydrogel design for functional regeneration.

Coal-assisted water electrolysis (CAWE) provides a low-temperature electrochemical route to hydrogen production by replacing the oxygen evolution reaction with carbon oxidation, but its performance is limited by interfacial polarization and surface passivation. This study introduces a low-frequency pulsed electrolysis as a strategy to improve the operational performance and reduce the electrical energy consumption of Fe3+-assisted CAWE by periodically coupling high-potential oxidation with low-potential interfacial relaxation. An operating window of 1.22-1.62 V and 0.1-2 Hz was identified, with an optimum at 1.32 V and 2 Hz. Under the optimum condition, the cycle-averaged hydrogen production rate increases by more than 30%, while the specific electrical energy consumption during electrolysis is reduced by approximately 50% compared with constant-potential operation over the same operating time. Spectroscopic and microscopic characterizations demonstrate the formation of a thinner and more uniform oxidized surface, suppressed passivation, and retention of the mineral framework. Product analysis shows a shift toward short-chain organics dominated by aldehydes, suggesting that pulsed operation influences the distribution of detectable partial-oxidation products. These results show that time-structured electrolysis lowers energy consumption and improves interfacial durability in Fe3+-assisted CAWE.

Urban forest ecosystems are the key contributors to the green spaces within metropolitan landscapes, offering numerous ecological services. But the combined effects of anthropogenic activities driven by population growth and escalating resource demands have precipitated rapid modification in forest structure, extent, and environmental conditions (i.e., nutrient dynamics) of such areas. This study investigates how human disturbances affect Korean pine urban forests through examinations of non-spatial structure and physiological, biochemical and soil responses. Tree height decreased (R2 = 0.463, p < 0.001) while canopy cover increased (R2 = 0.132, p < 0.001) as disturbance intensity intensified. Needle indole-3-acetic acid (IAA) and gibberellic acid (GA3) content varied significantly (p = 0.017 and p = 0.049) across the various disturbance levels, with significant seasonal cytokinin and GA3 changes under very low disturbance (p = 0.023 and 0.040) and pronounced IAA and GA3 under heavy disturbance (p = 0.026 and 0.024). Needle moisture content varies significantly (p = 0.029) with increasing disturbance and significant seasonal changes only when disturbances reached heavy intensity level (p = 0.0138), and chlorophyll (Chl) a (p = 0.0002), Chl b (p = 0.009), and total Chl (p = 0.0004) were disturbance sensitive. In addition, annual glucose (p < 0.001), starch (p < 0.01), and non-structural carbohydrate (p < 0.001) content in needle, branches, and root were exhibited significant change with increasing disturbance, seasonal variations especially found in heavily disturbed sites (p < 0.05). Nutrient element content (i.e., carbon and nitrogen ratio, total phosphorus, and total potassium) in needles, branches, roots, and soil showed significant differences (p < 0.05) with increasing disturbance intensities, except for phosphorus in roots which was not significant. These findings quantified the threshold at which urban disturbances impair Korean pine resilience and point out the urgency of regulating anthropogenic disturbances and restoring soil nutrient conditions. This study advances urban forest ecology by linking disturbance intensity to physiological thresholds and nutrient depletion, supporting for integrated conservation frameworks that prioritize urban forests alongside protected areas. Future research should target urban Korean pine growth, particularly regarding height increments, and highlights the importance of nutrient management and disturbance mitigation.

Boreal forests play a pivotal role in the global carbon balance and climate change mitigation. Understanding their carbon exchange dynamics is essential for advancing knowledge of forest carbon cycling. However, studies addressing multi-scale carbon flux variability and its drivers in China’s boreal forests remain limited. This study analyzed five years (2019–2023) of growing-season eddy covariance data from a Larix gmelinii forest in the Greater Khingan Mountains to elucidate seasonal and interannual variations in carbon fluxes and their driving mechanisms. On average, the growing season net ecosystem carbon exchange (NEE), gross primary productivity (GPP), and ecosystem respiration (Re) were − 376.99 ± 44.24, 856.15 ± 37.99 and 479.16 ± 51.46 g m−2, respectively, indicating that the forest consistently functioned as a moderate carbon sink. At seasonal variations, NEE exhibited a “U”-shaped pattern, predominantly driven by GPP. Path analysis showed that photosynthetically active radiation (PAR) mainly influenced seasonal variations of NEE, leaf area index (LAI) was the key factor for GPP seasonal variations, while vapor pressure deficit (VPD) limited both NEE and GPP variations. Re was primarily influenced by soil temperature (Ts). In contrast, interannual NEE variations were relatively stable and predominantly controlled by Re, with higher PAR and fewer precipitation days enhancing carbon sequestration. These findings demonstrate the divergent controls of environmental and biological factors across timescales. Long-term monitoring of boreal forest carbon dynamics is critical for predicting their carbon sink potential under future climate warming and improving global carbon cycle models.

Accurately estimating the net primary productivity (NPP) of forests in high-latitude, ecologically fragile regions and understanding its spatiotemporal drivers are crucial for assessing global carbon balance and achieving sustainable development under climate change. This study focuses on the Tahe River Basin in the Greater Khingan Mountains; utilising the Carnegie Ames Stanford Approach (CASA) model, we simulated the spatiotemporal dynamics of watershed NPP and investigated its driving mechanisms. Notably, this research reveals the asymmetric response mechanisms of NPP to water deficit and surplus states among different forest types in the northern forests. The results indicate that the multi-year average NPP in the Tahe River Basin from 1982 to 2022 was 483.01 g C m(-2) a(-1), exhibiting a significant increasing trend at a rate of 5.62 g C m(-2) a(-1). NPP decreased with elevation but showed no slope dependence. Precipitation dominated NPP variation, with forest-type ranking: deciduous broadleaf > deciduous coniferous > evergreen coniferous. Mild drought reduced watershed NPP by 20.39 g C m(-2) a(-1), while severe drought led to a loss of 45.27 g C m(-2) a(-1). Mild wetness slightly promoted NPP, whereas severe wetness exerted an even stronger disruptive effect on NPP than severe drought. Responses of NPP to drought varied significantly among vegetation types, with coniferous forests demonstrating stronger resistance. Severe wetness significantly reduced NPP in all three vegetation types, resulting in losses of 20.66%, 11.97% and 19.06% for deciduous broadleaf forest, evergreen coniferous forest and deciduous coniferous forest, respectively. The asymmetric response mechanism to water deficit/surplus revealed in this study, along with its dependence on forest type, addresses a critical gap in the theoretical framework of forest carbon cycle driving mechanisms in high-latitude ecologically fragile zones. It is critical for reliably evaluating the stability of forest carbon sinks and for guiding the design of effective, nature-based adaptation strategies in these regions facing climate change.