Transgenerational toxicity induced by maternal AFB1 exposure in Caenorhabditis elegans associated with underlying epigenetic regulations.

Aflatoxin B1 (AFB1), usually seriously contaminates in grain and oil foods or feed, displayed significant acute and chronic toxic effects in human and animal populations. However, little is known about the transgenerational toxic effects induced by a maternal AFB1 intake at a lower dose on offspring. In our study, only parental wild-type Caenorhabditis elegans was exposed to AFB1 (0-8 µg/ml) and the following three filial generations were grown on AFB1-free NGM. Results showed that the toxic effects of AFB1 on the growth (body length) and reproduction (brood size, generation time and morphology of gonad arm) can be transmitted through generations. Moreover, the levels of MMP and ATP were irreversibly inhibited in the filial generations. By using RNomics and molecular biology techniques, we found that steroid biosynthesis, phagosome, valine/leucine/isoleucine biosynthesis and oxidative phosphorylation (p < 0.05) were the core signaling pathways to exert the transgenerational toxic effects on nematodes. Also, notably increased histone methylation level at H3K36me3 was observed in the first generation. Taken together, our study demonstrated that AFB1 has notable transgenerational toxic effects, which were resulted from the complex regulatory network of various miRNAs, mRNAs and epigenetic modification in C. elegans.

Ursolic acid alleviates paclitaxel-induced peripheral neuropathy through PPARγ activation.

BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) reduces the overall quality of life and leads to interruption of chemotherapy. Ursolic acid, a triterpenoid naturally which presents in fruit peels and in many herbs and spices, can function as a peroxisome proliferator-activated receptor γ (PPARγ) agonist, and has been widely used as an herbal medicine with a wide spectrum of pharmacological activities, including anti-cancer, anti-inflammatory and neuroprotective effect. METHODS: We used a phenotypic drug screening approach to identify ursolic acid as a potential neuroprotective drug in vitro and in vivo and carried out additional biochemical experiments to identify its mechanism of action. RESULTS: Our study demonstrated that ursolic acid reduced neurotoxicity and cell apoptosis induced by pacilitaxel, resulting in an improvement of CIPN. Moreover, we explored the potential mechanisms of ursolic acid on CIPN. As a result, ursolic acid inhibited CHOP (C/EBP Homologous Protein) expression, indicating the endoplasmic reticulum (ER) stress suppression, and regulating CHOP related apoptosis regulator (the Bcl2 family) to reverse pacilitaxel induced apoptosis. Moreover, we showed that the therapeutic effect of ursolic acid on the pacilitaxel-induced peripheral neuropathy is PPARγ dependent. CONCLUSIONS: Taken together, the present study suggests ursolic acid has potential as a new PPARγ agonist targeting ER stress-related apoptotic pathways to ameliorate pacilitaxel-induced peripheral neuropathic pain and nerve injury, providing new clinical therapeutic method for CIPN.

Magnetic molecular imprinted covalent organic framework composite for the magnetic solid-phase extraction of bisphenol AF.

A magnetic molecular imprinted covalent organic framework composite (MCOF-MIP) that possessed the 'dual-selectivity' of a covalent organic framework and molecular imprinted polymer (MIP) with rapid response performance was successfully prepared for the removal of bisphenol AF (BPAF) from real water and blood samples. First, the MCOF was separately synthesized using magnetic Fe3O4 as the magnetic core, 1,3,5-triaminobenzene and 2,5-dibromobenzene-1,4-diformaldehyde as precursors and a deep eutectic solvent (DES) as the solvent using a solvothermal synthesis method. The MCOF showed high crystallinity and good adsorption capacities for BPAF (107.4 mg g-1), bisphenol A (113.6 mg g-1), bisphenol S (120.0 mg g-1) and bisphenol F (82.1 mg g-1). To further improve the selectivity for BPAF, an MIP, which uses BPAF as a template, was introduced to form the MCOF-MIP. Due to the dual selectivity of MCOF and MIP, the MCOF-MIP exhibited relatively high selective adsorption capacity to BPAF (243.1 mg g-1) compared to that for the MCOF (107.4 mg g-1), while the adsorption capacities (149.7-109.4 mg g-1) for the other three compounds were not significantly improved. Furthermore, a magnetic solid-phase extraction (MSPE) method was established, and MSPE parameters such as adsorbent dosage, adsorption time, desorption solvent and desorption time were optimized. Combined with high-performance liquid chromatography with diode-array detection (HPLC-DAD) analysis, a rapid and sensitive method was developed to detect BPAF, which showed good linearity (r > 0.9969) ranging from 0.1 to 400 µg mL-1. Low limits of detection (0.04 µg mL-1, S/N = 3) and quantitation (0.1 µg mL-1, S/N = 10) and good precision with low relative SDs (<1.2 % for intra-day and <1.1 % for inter-day) were also obtained. Finally, MSPE coupled with HPLC-DAD was employed for the analysis of BPAF in water and blood samples, and the recoveries of BPAF were satisfactory (91.1-112.6 %).

Synergistic toxicity induced by the co-exposure of tenuazonic acid and patulin in Caenorhabditis elegans: Daf-16 plays an important regulatory role.

Tenuazonic acid (TeA) and patulin (PAT), as the naturally occurring mycotoxins with various toxic effects, are often detected in environment and food chain, has attracted more and more attention due to their widespread and high contaminations as well as the coexistence, which leads to potential human and animals' risks. However, their combined toxicity has not been reported yet. In our study, C. elegans was used to evaluate the type of combined toxicity caused by TeA+PAT and its related mechanisms. The results showed that TeA and PAT can induce synergistic toxic effects based on Combination Index (CI) evaluation model (Chou-Talalay method), that is, the body length, brood size as well as the levels of ROS, CAT and ATP were significantly affected in TeA+PAT-treated group compared with those in TeA- or PAT-treated group. Besides, the expressions of oxidative (daf-2, daf-16, cyp-35a2, ctl-1, ctl-3, pmk-1, jnk-1, skn-1) and intestinal (fat-5, pod-2, egl-8, pkc-3, ajm-1, nhx-2) stress-related genes were disrupted, among which daf-16 displayed the most significant alternation. Further study on daf-16 gene defective C. elegans showed that the damages to the mutant nematodes were significantly attenuated. Since daf-2, daf-16, jnk-1 and pmk-1 are evolutionarily conserved, our findings could hint synergistic toxic effects of TeA+PAT on higher organisms.

Fluorescent covalent organic frameworks for environmental pollutant detection sensors and enrichment sorbents: a mini-review.

Covalent organic frameworks (COFs) are a class of porous crystalline materials based on organic building blocks containing light elements, such as C, H, O, N, and B, interconnected by covalent bonds. Because of their regular crystal structure, high porosity, stable mechanical structure, satisfactory specific surface area, easy functionalization, and high tunability, they have important applications in several fields. Currently, most of the established methods based on COFs can only be used for individual detection or adsorption of the target. Impressively, fluorescent COFs as a special member of the COF family are able to achieve highly selective and sensitive detection of target pollutants by fluorescence enhancement or quenching. The construction of a dual-functional platform for detection and adsorption based on fluorescent COFs can enable the simultaneous realization of visual monitoring and adsorption of target pollutants. Therefore, this paper reviews the research progress of fluorescent COFs as fluorescence sensors and adsorbents. First, the fluorescent COFs were classified according to the different bonding modes between the building blocks, and then the applications of fluorescent COF-based detection and adsorption bifunctional materials for various environmental contaminants were highlighted. Finally, the challenges and future application prospects of fluorescent COFs are discussed.

Effects of maternal high-fat diet on fetal growth, placental nutrient transporters and circular RNA expression profiles.

Epidemiological and experimental studies suggest that there is a strong correlation between maternal high-fat diet and fetal-placental development. The current study aims to investigate the effects of maternal high-fat diet on fetal growth, placental nutrient transporters and circular RNA expression profiles in a mouse model. Forty C57BL/6 female mice were randomly assigned to two groups, fed either a control (10% fat for energy) diet (CON) or a high-fat (60% fat for energy) diet (HFD) for 4 weeks before mating and throughout pregnancy, and were killed on day 19.5 of pregnancy. The serum glucose, total cholesterol and low-density lipoprotein, the glucolipid metabolism-related hormones, and the insulin resistance index were significantly increased. High-throughput sequencing showed that differentially expressed circRNAs (DE circRNAs) in the placenta can regulate various biological processes, cellular components, and molecular functions through various energy metabolism pathways, and mmu-let-7g-5p was found to target and bind to multiple DE circRNAs. In addition, this study also predicted that various circRNAs with protein coding functions can regulate maternal placental nutrient transport. In general, the ceRNA (circRNAs-miRNAs-mRNAs) regulatory network of maternal placental nutrient transport constructed in this study is of great significance for further understanding the effect of maternal nutrition on fetal growth in the future.

Carbonized human hair derived carbon dots for detection of clozapine.

Clozapine (CLZ) is known as the most effective antipsychotic medication for schizophrenia. However, low dosage or over dosage of CLZ is adverse to the treatment of Schizophrenia. Thus, it is necessary to develop effective detection method for CLZ. Recently, due to the advantages such as excellent optical properties, good photobleachability and sensitivity, carbon dots (CDs)-based fluorescent sensors for the detection of target analytes have drawn a great deal of attention. In this work, blue fluorescent CDs (Named as B-CDs) with quantum yield (QY) as high as 38% were obtained by using carbonized human hair as source material through one-step dialysis method for the first time. B-CDs showed obvious graphite-like structure with an average of 1.76 nm, containing abundant functional groups such as -C=O, amino N and C-N on the surface of carbon cores. Optical analysis showed that the B-CDs exhibited excitation-dependent emission property with maximum emission wavelength of 450 nm. Moreover, B-CDs were further applied as a fluorescence sensor to the detection of CLZ. The B-CDs based sensor exhibited a good quenching response by CLZ through the inner filter effect and static quenching mechanism with a limit of detection of 67 ng/mL, which was much lower than the minimal effective concentration in blood (0.35 µg/mL). Finally, to test the practical application value of the developed fluorescence method, the determination of the content of CLZ in tablets and the concentration in blood was carried out. Compared with the results of high-performance liquid chromatography (HPLC) method, it can be found that the constructed fluorescence detection method showed high accuracy and had great application potential in the detection of CLZ. Additionally, the results of cytotoxicity experiment showed that B-CDs had low cytotoxicity, which laid the foundation for the subsequent application of B-CDs in biological systems.

Fabrication of highly crystalline covalent organic framework for solid-phase extraction of three dyes from food and water samples.

Herein, a covalent organic framework, which was fabricated at room temperature by using 1,3,5-tris(p-formylphenyl) benzene and 1,3,5-tris(4-aminophenyl)benzene as building blocks, was employed as an adsorbent for solid-phase extraction of dyes including congo red, methyl blue and direct red 80 for the first time. The prepared covalent organic framework was properly characterized by different techniques and the results revealed that it had a uniform spherical structure, high crystallinity, satisfactory surface area, and good thermal stability. Moreover, the adsorption performance of the material was explored by using static and dynamic adsorption experiments and the results indicated that the material showed good adsorption capacities for three dyes with adsorption capacities in the range of 55.25-284.10 mg/g and the adsorption equilibrium can be achieved in 15 min. Further, to achieve the best adsorption effects of the material, the influence parameters such as pH, ionic strength, type of desorption solvent, and the material dosage in the solid-phase extraction column, were optimized in turn. Finally, under optimal conditions, the solid-phase extraction coupled with HPLC was applied to the analysis of dyes in food and water samples. The recoveries of dyes in actual samples were satisfactory, revealing the unique applicability of the material in the sample pretreatment field.

Salt taste threshold and contributory factors of chronic kidney disease patients: a cross-sectional study.

PROPOSE: High salt intake, correlated with high salt taste threshold, may accelerate renal injury in chronic kidney disease (CKD) patients. However, few studies have focused on factors that influence salt taste threshold. Therefore, we aimed to identify factors that influence the salt taste threshold of CKD patients, to provide more precise salt restriction recommendations in dietary therapy. METHODS: Between April 2016 and March 2019, we measured the salt taste threshold of 1019 CKD patients, aged 22-78 years, from 52 hospitals across southwestern China, and then we performed a cross-sectional study. RESULTS: The mean salt taste threshold was 0.37 ± 0.16% NaCl. There were 115 (11.3%), 670 (65.7%), and 234 (23.0%), respectively, patients who had low (≤ 0.1% NaCl), medium (0.1-0.4% NaCl), and high (> 0.4% NaCl) salt taste thresholds. One-way ANOVA and regression results revealed that sex (male), age, decreased estimated glomerular filtration rate, and absence of salt restriction were factors that influenced CKD groups with high salt taste threshold. CONCLUSION: We found an independent correlation between contributory factors including sex, age, eGFR, and salt restriction behavior of subjects with the salt taste threshold of CKD patients. Our findings also offer insights on salt taste thresholds that could be useful for clinicians advising salt restriction to impair the salt taste sensitivity of the corresponding populations.

Towards fast sensing along ultralong BOTDA: flatness enhancement by utilizing injection-locked dual-bandwidth probe wave.

Brillouin optical time-domain analysis (BOTDA) using distributed Brillouin amplification (DBA) only requires a milliwatt-level pump to achieve a sensing range beyond 100 km, which provides a powerful tool for temperature/strain sensing. However, similar to the majority of other long-range BOTDAs, the state-of-the-art reports require > 1000 times average, severely restricting the sensing speed. The blind area over tens of kilometers caused by the nonuniform Brillouin response and parasitic amplitude modulation (AM) are crucial factors affecting the signal-to-noise ratio (SNR). Here, a comprehensive performance optimization and substantial enhancement for BOTDA sensors was presented by the direct demodulation of an injection-locked dual-bandwidth probe wave. Injection locking (IL) can completely eliminate the impact of AM noise; dual-bandwidth probe enables self-adaptive pulse loss compensation, thereby intensifying the SNR flatness along the ultralong fiber, and direct probe demodulation can overcome nonlocal effects and allows ∼19.7 dB enhancement of probe input power. Therefore, using only 100 times average, ∼148.3 km sensing, and ∼5 m spatial resolution were achieved with < ∼0.8 MHz standard deviation of Brillouin frequency shift (BFS) over a broad range (∼131.7 km). The reduction in averages was more than 10 times that of the reported majority of long-range BOTDAs. Such performances were achieved without using time-consuming or post-processing techniques, such as optical pulse coding and image denoising. Because this approach is compatible with optical chirp chain technique without frequency sweeping, fast acquisition (0.3 s) was also realized, which has the potential for fast sensing at 3.3 Hz along a ∼150 km fiber.

Hydroxyl-riched covalent organic framework for solid-phase microextraction of flavonoids aglycones or their metabolites in mice's plasma: Luteolin and quercetagetin as examples.

Herein, a hydroxyl­riched covalent organic framework (named COF-DES-1) was synthesized using 1,3,5-tris(4-aminophenyl)benzene and 2,5-dihydroxyterephthalaldehyde as building blocks and employed as a coating of solid-phase microextraction (SPME) fiber. Ascribed to the advantages (e.g. suitable pore size and rich functional group characteristics) of coating, the SPME fiber showed good adsorption capacities to flavonoids aglycones including luteolin and quercetagetin, and the maximum adsorption capacities for them were 145.31 µg and 84.75 µg, respectively. Due to the size exclusion property of COF-DES-1, SPME fiber showed good protein exclusion effects on seven selected proteins with high exclusion efficiencies (>93%). Accordingly, an attractive strategy of the combination of COF-DES-1 based SPME fiber and HPLC-MS/MS was proposed for the extraction and determination of luteolin, quercetagetin or their metabolites. The results revealed that the fiber can be effectively applied to extract luteolin and its metabolites, and quercetagetin from mice's palsma. Compared with the traditional protein precipitation methods, the extraction effects of SPME fiber based extraction method were much better, indicating the promising applicability of the fiber for the enrichment of flavonoids aglycones or their metabolites in biological samples.

Soil moisture affects plant-pollinator interactions in an annual flowering plant.

Many environmental factors impact plant and pollinator communities. However, variation in soil moisture and how it mediates the plant-pollinator interactions has yet to be elucidated. We hypothesized that long-term variation in soil moisture can exert a strong selective pressure on the floral and vegetative traits of plants, leading to changes in pollinator visitation. We demonstrated that there are three phenotypic populations of Gentiana aristata in our study alpine region in the Qinghai-Tibetan Plateau that vary in floral colour and other traits. Pink (dry habitat) and blue (intermediate habitat) flower populations are visited primarily by bumblebees, and white (wet habitat) flower populations are visited by flies. These patterns of visitation are driven by vegetative and floral traits and are constant when non-endemic plants are placed in the intermediate habitats. Additionally, the floral communities in different habitats vary, with more insect-pollinated forbs in the dry and intermediate habitats versus the wet habitats. Through a common garden and reciprocal transplant experiment, we demonstrated that plant growth traits, pollinator attractiveness and seed production are highest when the plant population is raised in its endemic habitat. This suggests that these plant populations have evolved to pollinator communities associated with habitat differences. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.

[Effect of Vegetation Coverage on the Temporal and Spatial Distribution of PM2.5 Concentration in China's Eight Major Economic Regions from 1998 to 2016].

The study researched the relationship between vegetation cover and PM2.5 pollution. The raster NDVI dataset from 1998 to 2016 were reclassified into low, medium, and high vegetation coverage area, and the corresponding PM2.5 concentration in eight economic regions in China were then calculated. On this basis, the temporal and spatial characteristics of PM2.5 pollution were analyzed and Pearson correlation coefficient was used to explore its correlation with NDVI landscape pattern indexes separately from landscape and class level NDVI. The preliminary results showed that:①The northern, eastern, southern coastal, middle reaches of the Yangtze River, and the northeast economic zones have relatively low vegetation coverage in areas with relatively serious PM2.5 pollution. However, the middle reaches of the Yellow River, the southwestern and the Northwestern Economic Zones in areas with relatively low vegetation coverage showed lighter PM2.5 pollution. ②PM2.5 increased in most areas between 1998 and 2016. ③A significant correlation between PM2.5 and NDVI landscape pattern indexes was not found for all areas. ④Therefore, the impacts of the landscape shape index(LSI), percent of landscape(PLAND), number of patches(NP), largest patch index(LPI), and aggregation index(AI) on PM2.5 are heterogeneous.

Injectable self-healing bioactive antioxidative one-component poly(salicylic acid) hydrogel with strong ultraviolet-shielding for preventing skin light injury.

The design and development of one-component temperature-sensitive bioactive hydrogel with multifunctional properties for protecting skin against light injury remain a challenge. Herein, we report a bioactive multifunctional poly(salicylic acid)-F127-poly(salicylic acid) copolymer hydrogel (FPSa) with one-component for potential skin protection applications. The FPSa hydrogel possesses the thermosensitivity (23 °C), injectability, self-healing ability, ultraviolet shielding (shielding the wavelength between 280 and 370 nm), and antioxidation activity (above 70%), and also showed the good cytocompatibility (cell survival rate >90% and hemolysis rate less than 5%) and biodegradability (90% weight loss at 3 days). The in vivo animal model showed that FPSa hydrogel could effectively protect the skin tissue and prevent the ultraviolet induced injury. This study can provide a strategy to design multifunctional bioactive hydrogel with simple composition for disease therapy and regenerative medicine.

The complete chloroplast genome of Ottelia acuminate var. crispa, an endangered aquatic herb with extremely narrow distribution.

Ottelia acuminate var. crispa is an endangered aquatic herb with extremely narrow distribution. In this study, we assembled the chloroplast genome of this species based on the second-generation high-throughput sequencing. The genome is 157,783 bp in length with a typical quadripartite structure including a large single-copy region (LSC) of 88,294 bp, a small single-copy region (SSC) of 49,379 bp, and a pair of inverted repeats (IRs) of 10,055 bp each. A total of 128 genes were annotated, including 83 protein-coding genes (PCG), 37 tRNA genes, and 8 rRNA genes. The phylogenetic tree shows that O. acuminate var. crispa has a close relationship with the genus Elodea. The chloroplast genome presented here provides a valuable resource to conserve this endangered species.

Water-Mediated Catalytic Decarboxylation Enabled Polysubstituted Furans and Allylic Alcohols with Exclusive (E)-Configurations.

A water-mediated catalytic decarboxylation process toward the formation of polysubstituted furans and (E)-allylic alcohols has been reported. This protocol features wide functional group tolerance, easy operation, and only CO2-byproduct generation. These reactions can be performed on a large scale open to air under extremely ambient conditions. A range of control experiments revealed the crucial role of the water for the successful conversions as well as the origin of the chemoselectivity and exclusive stereoselectivity.

Modular Domino Process toward Highly Functionalized Pyrroles via Pd-Catalyzed [4 + 1] Annulation under Mild Conditions.

A Pd-catalyzed decarboxylative approach for the modular synthesis of highly functionalized pyrroles is presented. This protocol utilizes readily available cyclic carbonates and amines as reaction partners and only generates CO2 and H2O as byproducts. This methodology could be operated at room temperature and open to air, thus serving as an ideal means for the derivatization of bioactive compounds. Mechanism investigations suggested that the stereoselective formation of the (Z)-configured γ-amino ketone intermediate is crucial for the success of the reaction.

Traditional Chinese Medicine Formula Kang Shuai Lao Pian Improves Obesity, Gut Dysbiosis, and Fecal Metabolic Disorders in High-Fat Diet-Fed Mice.

High-fat diet (HFD)-induced obesity is a risk factor for many metabolic disorders including cardiovascular diseases, diabetes, and fatty liver disease. Although there are accumulating evidences supporting the assumption that regulating gut microbiota as well as its metabolic status is able to mitigate obesity, the inner relationship between the obesity-related gut microbiota and the relevant metabolites are not well defined. In current study, we applied a traditional herbal formula Kang Shuai Lao Pian (KSLP) to HFD-fed mice and evaluated its effect against obesity. Emphases were addressed on identifying profiles of gut microbiota and fecal metabolites with the aid of 16S rRNA gene sequencing and non-target fecal metabolomics techniques. We showed that KSLP could improve HFD-induced obesity, glucose tolerance disorder, as well as gut dysbiosis. In the gut, KSLP corrected the increased abundance of Firmicutes and Proteobacteria, increased ratio of Firmicutes/Bacteroidetes, and decreased abundance of Bacteroidetes caused by HFD. KSLP also reversed HFD-induced significant changes in the abundance of certain genus including Intestinimonas, Oscillibacter, Christensenellaceae_R-7_group, Ruminococcaceae_UCG-010, and Aliihoeflea. Pearson correlation analysis indicated that except for Ruminococcaceae_UCG-010, other four genera had positive correlations with obesity. In addition, 22 key fecal metabolites responding to KSLP treatment were identified. Pearson correlation analysis showed that those metabolites are intimately related to KSLP effective genera of Intestinimonas, Oscillibacter, and Christensenellaceae_R-7_group. Our results indicate that KSLP is a promising traditional Chinese medicine (TCM) applicable for individuals with HFD habit. Intestinimonas, Oscillibacter, and Christensenellaceae_R-7_group might be responsible for the regulatory effect of KSLP. Linking of obesity phenotypes with gut microbiota as well as fecal metabolites is therefore a powerful research strategy to reveal the mechanism of obesity and the targets of intervention.

Effects of Litterfall on the Accumulation of Extracted Soil Humic Substances in Subalpine Forests.

Plant litter is one of the main sources of soil humus, but which can also promote primary humus degradation by increasing microbial activity due to the higher availability of energy released, resulting in a confusing relationship between litterfall and soil humus. Therefore, an in situ incubation experiment was carried out in three subalpine forests (coniferous, mixed and broadleaved forests) on the eastern Qinghai-Tibetan Plateau. We set up two treatments. One that allowed litterfall to enter the soil normally and the other prevented litterfall to enter the soil. Soils were sampled in October (the end of the growing season), January (the onset of the freezing season), March (the end of the freezing season), and May (the start of the growing season) from May 2017 to May 2018. By assessing the litterfall production, the content of total extracted humus, humic acid (HA) and fulvic acid (FA) in the topsoil (0-20 cm) in each incubation period, we determined the impact of litterfall on the content of humus extracted from the soil during the freezing and the growing season. Over 1-year incubation, soil total extracted humus and HA showed considerable decreases in the treatment of retained litterfall in the mixed forest but not in the coniferous or broadleaved forests. Moreover, litterfall significantly reduced the contents of soil total extracted humus and HA during the growing season in all three forests, while only reduced soil HA content in the broadleaved forest in the freezing season. The relationship between litterfall and soil extracted humic substances was greatly regulated by the seasonal dynamics of litter types and litter production in all forest types. The larger the amount of litterfall was, the more litterfall could promote the reduction of soil extracted humic substances. Compared with a single type of broadleaf or needle litter, mixed litterfall could promote a higher degradation of soil humic substances. However, broadleaf litter might lead to much greater decreases in soil humic substance than needle litter because it is more decomposable. These results indicate that the effect of litterfall on soil humic substances are mainly regulated by litter types and litter production. Moreover, the effects of litterfall on soil humic substances are more significant during the growing season than winter. This suggests that the longer growing season and a shorter winter caused by ongoing global warming may alter the relationships between litterfall and extracted humic substances, further disrupting the carbon balance of forest ecosystems in the subalpine forests.

5-hydroxymethylfurfural-embedded poly (vinyl alcohol)/sodium alginate hybrid hydrogels accelerate wound healing.

Treating large acute or chronic wounds remains a challenging task because of a lack of effective methods to accelerate wound healing. Though growth factor-based wound products are found to be effective, they are costly and are potentially associated with increased cancer mortality. Effective, safe, and affordable strategies to tackle large or chronic wounds need to further be designed and developed. Here, we designed a new antioxidant-embedded hydrogel system for speeding up the wound healing process. We prepared multifunctional poly (vinyl alcohol)/sodium alginate (PVA/SA) hydrogels with the incorporation of 5-hydroxymethylfurfural (5-HMF) and silver nanoparticles (Ag-NPs), and investigated their physiochemical and biological properties in vitro and in vivo. PVA, SA, 5-HMF, and Ag-NPs were employed for good mechanical properties, good biocompatibility, anti-inflammation, and anti-bacterial activity, respectively. 5-HMF is commonly found in many food products (e.g. honey, coffee, and black garlic) and is known as an antioxidant. In our in vitro study, 5-HMF was found to effectively facilitate the proliferation and migration of human skin fibroblasts (HSF), and collagen production. Besides, 5-HMF-embedded PVA/SA hybrid hydrogels supported controlled release and good cell compatibility, and more importantly accelerated wound healing in vivo through ameliorated inflammation, enhanced angiogenesis/vascularization, increased collagen production, and promoted re-epithelialization.