Structural basis for the activity of the type VII CRISPR-Cas system.

The newly identified type VII CRISPR-Cas candidate system uses a CRISPR RNA-guided ribonucleoprotein complex formed by Cas5 and Cas7 proteins to target RNA1. However, the RNA cleavage is executed by a dedicated Cas14 nuclease, which is distinct from the effector nucleases of the other CRISPR-Cas systems. Here we report seven cryo-electron microscopy structures of the Cas14-bound interference complex at different functional states. Cas14, a tetrameric protein in solution, is recruited to the Cas5-Cas7 complex in a target RNA-dependent manner. The N-terminal catalytic domain of Cas14 binds a stretch of the substrate RNA for cleavage, whereas the C-terminal domain is primarily responsible for tethering Cas14 to the Cas5-Cas7 complex. The biochemical cleavage assays corroborate the captured functional conformations, revealing that Cas14 binds to different sites on the Cas5-Cas7 complex to execute individual cleavage events. Notably, a plugged-in arginine of Cas7 sandwiched by a C-shaped clamp of C-terminal domain precisely modulates Cas14 binding. More interestingly, target RNA cleavage is altered by a complementary protospacer flanking sequence at the 5' end, but not at the 3' end. Altogether, our study elucidates critical molecular details underlying the assembly of the interference complex and substrate cleavage in the type VII CRISPR-Cas system, which may help rational engineering of the type VII CRISPR-Cas system for biotechnological applications.

Effect of biochar and iron ore tailing waste amendments on cadmium bioavailability in a soil and peanut seedling system.

Biochar and iron ore tailing waste have been widely separately applied for remediation of various contaminants, but the remediation effect of their combination on cadmium (Cd) pollution is unclear. In this study, the peanut biochar (BC), thermally activated iron ore tailing waste (TS), and the products of the co-pyrolysis of peanut shell and iron ore tailing waste (TSBC) were prepared for stabilizing Cd and reducing its bio-accessibility in soil and peanut seedling system. Present amendments enhanced soil pH, cation exchange capacity, electrical conductivity, and organic carbon content. The application of BC, TS, and TSBC led to decreases in acid-extractable Cd proportion of 2.2-8.81%, 2.43-7.20%, and 7.84-11.57%, respectively, and increases in the residual Cd proportion of 3.48-8.33%, 3.27-11.50%, and 9.02-13.45%, respectively. There were no significant differences in Cd accumulation in peanut roots due to three amendments treatments, especially at low Cd concentrations (i.e., Cd concentration of 0, 1, and 2 mg·kg-1), and with a relatively small reduction (2.16-9.05%) in root Cd accumulation under the high Cd treatments of 5 and 10 mg·kg-1. The Cd concentrations in seedling roots were significantly positively related to the acid-extractable Cd fraction, with a Pearson correlation coefficient of r = 0.999. The maximum toxicity mitigating effects were found in TSBC treatment, with increases in the ranges of 9.80-17.58% for fresh weight, 5.59-14.99% for dry weight, 5.16-10.17% for plant height, 5.96-10.34% for root length, 5.43-21.67% for chlorophyll a content, 17.17-71.28% for chlorophyll b content, and 13.11-39.60% for carotenoid content in peanut seedlings. Therefore, TSBC is a promising amendment for minimizing Cd contamination in peanut crops and utilizing industrial solid waste materials efficiently.

A gut microbial metabolite cocktail fights against obesity through modulating the gut microbiota and hepatic leptin signaling.

BACKGROUND: Excessive body weight and obesity elevate the risk of chronic non-communicable diseases. The judicious application of the gut microbiome, encompassing both microorganisms and their derived compounds, holds considerable promise in the treatment of obesity. RESULTS: In this study, we showed that a cocktail of gut microbiota-derived metabolites, comprising indole 3-propionic acid (IPA), sodium butyrate (SB) and valeric acid (VA), alleviated various symptoms of obesity in both male and female mice subjected to a high-fat diet (HFD). The 16S ribosomal RNA (rRNA) sequencing revealed that administering the cocktail via oral gavage retained the gut microbiota composition in obese mice. Fecal microbiota transplantation using cocktail-treated mice as donors mitigated the obesity phenotype of HFD-fed mice. Transcriptomic sequencing analysis showed that the cocktail preserved the gene expression profile of hepatic tissues in obese mice, especially up-regulated the expression level of leptin receptor. Gene delivery via in vivo fluid dynamics further validated that the anti-obesity efficacy of the cocktail was dependent on leptin signaling at least partly. The cocktail also inhibited the expression of appetite stimulators in hypothalamus. Together, the metabolite cocktail combated adiposity by retaining the gut microbiota configuration and activating the hepatic leptin signaling pathway. CONCLUSIONS: Our findings provide a sophisticated regulatory network between the gut microbiome and host, and highlight a cocktail of gut microbiota-derived metabolites, including IPA, SB, and VA, might be a prospective intervention for anti-obesity in a preclinical setting. © 2024 Society of Chemical Industry.

Whole brain alignment of spatial transcriptomics between humans and mice with BrainAlign.

The increasing utilization of mouse models in human neuroscience research places higher demands on computational methods to translate findings from the mouse brain to the human one. In this study, we develop BrainAlign, a self-supervised learning approach, for the whole brain alignment of spatial transcriptomics (ST) between humans and mice. BrainAlign encodes spots and genes simultaneously in two separated shared embedding spaces by a heterogeneous graph neural network. We demonstrate that BrainAlign could integrate cross-species spots into the embedding space and reveal the conserved brain regions supported by ST information, which facilitates the detection of homologous regions between humans and mice. Genomic analysis further presents gene expression connections between humans and mice and reveals similar expression patterns for marker genes. Moreover, BrainAlign can accurately map spatially similar homologous regions or clusters onto a unified spatial structural domain while preserving their relative positions.

Study on the enhancement of citric acid chemical leaching of contaminated soil by modified nano zero-valent iron.

This study aimed to evaluate the effect of modified nanoscale zero-valent iron (SAS-nZVI) on chemical leaching of lead and cadmium composite contaminated soil by citric acid (CA). The synthesized SAS-nZVI was used as a leaching aid to improve the removal rate of soil heavy metals (HMs) by CA chemical leaching. The effects of various factors such as SAS-nZVI dosage, elution temperature and elution time were studied. At the same time, the effect of chemical leaching on the basic physical and chemical properties of soil and the morphology of HMs was evaluated. The results show that when the SAS-nZVI dosage is 2.0 g/L, the leaching temperature is 25 °C, and the leaching time is 720 min, the maximum removal rates of Pb and Cd in the soil are 77.64% and 97.15% respectively. The experimental results were evaluated using elution and desorption kinetic models (Elovich model, double constant model, diffusion model). The elution and desorption process of Pb and Cd in soil by SAS-nZVI-CA fitted well with the double-constant model, indicating that the desorption kinetic process of Pb and Cd is a heterogeneous diffusion process, and the elution process is controlled by diffusion factors. After leaching with SAS-nZVI-CA, the physical and chemical properties of the soil changed little, the mobility and toxicity of HMs in the soil were reduced, and the HMs content in the leaching waste liquid was reduced. It can be concluded that SAS-nZVI enhances the efficiency of CA in extracting Pb and Cd from soil, minimizes soil damage resulting from chemical leaching technology, and alleviates the challenges associated with treating leaching waste liquid.

Comprehensive Comparative Analysis of the JAZ Gene Family in Common Wheat (Triticum aestivum) and Its D-Subgenome Donor Aegilops tauschii.

JASMONATE-ZIM DOMAIN (JAZ) repressor proteins work as co-receptors in the jasmonic acid (JA) signalling pathway and are essential for plant development and environmental adaptation. Despite wheat being one of the main staple food crops, until recently, comprehensive analysis of its JAZ gene family has been limited due to the lack of complete and high-quality reference genomes. Here, using the latest reference genome, we identified 17 JAZ genes in the wheat D-genome donor Aegilops tauschii. Then, 54 TaJAZs were identified in common wheat. A systematic examination of the gene structures, conserved protein domains, and phylogenetic relationships of this gene family was performed. Five new JAZ genes were identified as being derived from tandem duplication after wheat divergence from other species. We integrated RNA-seq data and yield QTL information and found that tandemly duplicated TaJAZ genes were prone to association with spike-related traits. Moreover, 12 TaJAZ genes were located within breeding selection sweeps, including 9 tandemly duplicated ones. Haplotype variation analysis of selected JAZ genes showed significant association of TaJAZ7A and TaJAZ13A with thousand-grain weight. Our work provides a clearer picture of wheat JAZ gene evolution and puts forward the possibility of using these genes for wheat yield improvement.

Discovery of digallic acid as XOD/URAT1 dual target inhibitor for the treatment of hyperuricemia.

The development of XOD/URAT1 dual target inhibitors has emerged as a promising therapeutic strategy for the management of hyperuricemia. Here, through virtual screening, we have identified digallic acid as a novel dual target inhibitor of XOD/URAT1 and subsequently evaluated its pharmacological properties, pharmacokinetics, and toxicities. Digallic acid inhibited URAT1 with an IC50 of 5.34 ± 0.65 µM, which is less potent than benzbromarone (2.01 ± 0.36 µM) but more potent than lesinurad (10.36 ± 1.23 µM). Docking and mutation analysis indicated that residues S35, F241 and R477 of URAT1 confer a high affinity for digallic acid. Digallic acid inhibited XOD with an IC50 of 1.04 ± 0.23 µM. Its metabolic product, gallic acid, inhibited XOD with an IC50 of 0.91 ± 0.14 µM. Enzyme kinetic studies indicated that both digallic acid and gallic acid act as mixed-type XOD inhibitors. It shares the same binding mode as digallic acid, and residues E802, R880, F914, T1010, N768 and F1009 contribute to their high affinity. The anion group (carboxyl) of digallic acid contribute significantly to its inhibition activity on both XOD and URAT1 as indicated by docking analysis. Remarkably, at a dosage of 10 mg/kg in vivo, digallic acid exhibited a stronger urate-lowering and uricosuric effect compared to the positive drug benzbromarone and lesinurad. Pharmacokinetic study indicated that digallic acid can be hydrolyzed into gallic acid in vivo and has a t1/2 of 0.77 ± 0.10 h. Further toxicity evaluation indicated that digallic acid exhibited no obvious renal toxicity, as reflected by CCK-8, biochemical analysis (CR and BUN) and HE examination. The findings of our study can provide valuable insights for the development of XOD/URAT1 dual target inhibitors, and digallic acid deserves further investigation as a potential anti-hyperuricemic drug.

Ecological and health risk assessments of heavy metals and their accumulation in a peanut-soil system.

Heavy metals pollution is a notable threat to environment and human health. This study evaluated the potential ecological and health risks of heavy metals (Cu, Cr, Cd, Pb, Zn, Ni, and As) and their accumulation in a peanut-soil system based on 34 soil and peanut kernel paired samples across China. Soil As and Cd posed the greatest pollution risk with 47.1% and 17.6% of soil samples exceeding the risk screen levels, respectively, with 26.5% and 20.6% of the soil sites at relatively strong potential ecological risk level, respectively, and with the geo-accumulation levels at several soil sites in the uncontaminated to moderately contaminated categories. About 35.29% and 2.94% of soil sites were moderately and severely polluted based on Nemerow comprehensive pollution index, respectively, and a total of 32.4% of samples were at moderate ecological hazard level based on comprehensive potential ecological risk index values. The Cd, Cr, Ni, and Cu contents exceeded the standard in 11.76, 8.82, 11.76 and 5.88% of the peanut kernel samples, respectively. Soil metals posed more health risks to children than adults in the order As > Ni > Cr > Cu > Pb > Zn > Cd for non-carcinogenic health risks and Ni > Cr â‰« Cd > As > Pb for carcinogenic health risks. The soil As non-cancer risk index for children was greater than the permitted limits at 14 sites, and soil Ni and Cr posed the greatest carcinogenic risk to adults and children at many soil sites. The metals in peanut did not pose a non-carcinogenic risk according to standard. Peanut kernels had strong enrichment ability for Cd with an average bio-concentration factor (BCF) of 1.62. Soil metals contents and significant soil properties accounted for 35-74% of the variation in the BCF values of metals based on empirical prediction models.

Genome-wide identification of GA2ox genes family and analysis of PbrGA2ox1-mediated enhanced chlorophyll accumulation by promoting chloroplast development in pear.

BACKGROUND: Chlorophyll (Chl) is an agronomic trait associated with photosynthesis and yield. Gibberellin 2-oxidases (GA2oxs) have previously been shown to be involved in Chl accumulation. However, whether and how the PbrGA2ox proteins (PbrGA2oxs) mediate Chl accumulation in pear (Pyrus spp.) is scarce. RESULTS: Here, we aimed to elucidate the role of the pear GA2ox gene family in Chl accumulation and the related underlying mechanisms. We isolated 13 PbrGA2ox genes (PbrGA2oxs) from the pear database and identified PbrGA2ox1 as a potential regulator of Chl accumulation. We found that transiently overexpressing PbrGA2ox1 in chlorotic pear leaves led to Chl accumulation, and PbrGA2ox1 silencing in normal pear leaves led to Chl degradation, as evident by the regreening and chlorosis phenomenon, respectively. Meanwhile, PbrGA2ox1-overexpressing (OE) tobacco plants discernably exhibited Chl built-up, as evidenced by significantly higher Pn and Fv/Fm. In addition, RNA sequencing (RNA-seq), physiological and biochemical investigations revealed an increase in abscisic acid (ABA), methyl jasmonate (MeJA), and salicylic acid (SA) concentrations and signaling pathways; a marked elevation in reducing and soluble sugar contents; and a marginal decline in the starch and sucrose levels in OE plants. Interestingly, PbrGA2ox1 overexpression did not prominently affect Chl synthesis. However, it indeed facilitated chloroplast development by increasing chloroplast number per cell and compacting the thylakoid granum stacks. These findings might jointly contribute to Chl accumulation in OE plants. CONCLUSION: Overall, our results suggested that GA2oxs accelerate Chl accumulation by stimulating chloroplast development and proved the potential of PbrGA2ox1 as a candidate gene for genetically breeding biofortified pear plants with a higher yield.

Microbiomic signatures of anal fistula and putative sources of microbes.

Anal fistula is a common perianal disease that typically develops from an abscess caused by in-flammation in the area. It has long been believed that intestinal microbes play a significant role in its development, considering its close relation to the intestinal environment. This work attempts to identify the microbiomic signatures of anal fistula, and putative sources of microbes by analyzing microbiomes of 7 anal fistula-associated sites in 12 patients. This study found that microbes in anal fistulas may originate from the skin surface in addition to the intestinal tract. This finding was further validated by NMDS analysis, which also indicated that the microbial communities in the inner and outer openings of the fistula were more similar to their surrounding environments. Using MaAslin2, the characteristics of the microbiome were examined, demonstrating a higher similarity between the abundant bacteria in the anal fistula samples and those found on the skin surface. Moreover, pin-to-pair analysis conducted on all subjects consistently showed a higher abundance of skin-sourced bacteria in anal fistulas. This study identifies the microbiomic signatures of anal fistula, and provides novel insights into the origin of microorganisms in anal fistulas.

Effects of Ca2+ and Mg2+ on Cu binding in hydrophilic and hydrophobic dissolved organic matter fractions extracted from agricultural soil.

Dissolved organic matter (DOM) has significant effects on soil copper (Cu) bioavailability. However, little is known about Cu interactions and major cation binding toward hydrophilic and hydrophobic DOM components extracted from soil solutions. In this study, we investigated the influence of major cations (Ca2+/Mg2+) on Cu complexing characteristics on different hydrophilic and hydrophobic DOM fractions using absorbance spectroscopy at different Cu2+ concentrations in the absence/presence of Ca2+/Mg2+. Different compositional hydrophobic and hydrophilic DOM fraction proportions occurred at three agricultural soil sites, with the hydrophobic acid (HOA) fraction accounting for the highest proportion. The addition of Cu2+ generated distinct ultraviolet (UV) bands/peaks (processed by differential linear and differential logarithmic transformation) of three hydrophilic DOM fractions, whereas Cu2+ induced less and weak specific peaks in the differential spectra and differential logarithmic of the HOA fractions, indicating hydrophilic DOM fractions tend to have a higher density of Cu2+ complexation sites. In the presence of either Ca2+/Mg2+, increased depression caused by Cu2+ binding on different DOM fractions was observed with increasing 10, 100, and 1000 µM Ca2+/Mg2+ levels, with more significant variations in peaks/banks for hydrophilic base (HIB) and HOA fractions, and less for hydrophilic acid (HIA) and hydrophilic neutral (HIN) fractions. In our study, the spectral parameters ΔS225-275 and ΔS275-325 were successfully used to quantify Cu amounts bonded to HIA and HIB, respectively. They exhibited strong linear relationships with correlation coefficients (R2) of 0.96 for HIA and 0.87 for HIB, respectively. Furthermore, Mg2+ exhibited stronger competition with Cu for HIA and HIB binding sites when compared with Ca2+.

Effects of electroacupuncture on repairing neurological damage following ischemic stroke based on miR-381-mediated SDF-1/CXCR4 signaling pathway. / 基于miR-381调控SDF-1/CXCR4信号通路探讨电针对缺血性脑卒中后神经损伤修复的影响.

OBJECTIVES: To investigate the effects of electroacupuncture (EA) on the miR-381, leucine-rich repeat C4 protein (LRRC4), and downstream stromal cell-derived factor-1 (SDF-1)/CXC chemokine receptor 4 (CXCR4) signaling pathway in rat model of ischemic stroke, and to explore the mechanism by which EA improves neurological damage following ischemic stroke. METHODS: Among 50 SPF male SD rats, 10 rats were randomly selected into a sham surgery group, and the remaining rats were used to establish the middle cerebral artery occlusion (MCAO) model. The 30 successfully modeled rats were randomly divided into a model group, an EA group, and an agonist group, with 10 rats in each group. The rats in the EA group received EA at "Baihui" (GV 20) and "Dazhui" (GV 14), with disperse-dense wave, a frequency of 2 Hz/10 Hz, and a current intensity of 1 mA, 30 min per session, once daily for a total of 14 days. The rats in the agonist group received miR-381 agonist injections into the lateral ventricle, with 10 µL per injection, every 7 days for a total of 2 injections. After intervention, ZeaLonga neurobehavioral deficit score was observed in each group. HE staining was performed to observe the morphological changes in the ischemic brain tissue of rats in each group. ELISA was used to measure the levels of tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and nerve growth factor (NGF) in serum. Western blot was employed to detect the protein expression of LRRC4, SDF-1, CXCR4, and extracellular regulated protein kinase 1 (ERK1) in the ischemic brain tissue. Real-time PCR was utilized to assess the expression of miR-381 and LRRC4, SDF-1, CXCR4, ERK1 mRNA in the ischemic brain tissue. RESULTS: After intervention, the brain tissue showed disordered cell arrangement, reduced quantity, and significant interstitial edema, with numerous vacuoles in the model group. The pathological changes mentioned above were alleviated in the brain tissue of rats in the EA group and the agonist group. Compared with the sham surgery group, the rats in the model group exhibited increased ZeaLonga neurobehavioral deficit scores, elevated levels of serum TNF-α and IL-6 (P<0.01), and decreased serum NGF level (P<0.01)；the protein expression of SDF-1, CXCR4 and ERK1 in ischemic brain tissue was reduced (P<0.01), while LRRC4 protein expression was increased (P<0.01)；the expression of miR-381, as well as SDF-1, CXCR4 and ERK1 mRNA in ischemic brain tissue was decreased (P<0.01), while LRRC4 mRNA expression was increased (P<0.01). Compared with the model group, the rats in the EA group and the agonist group showed decreased ZeaLonga neurobehavioral deficit scores and reduced levels of serum TNF-α and IL-6 (P<0.05, P<0.01), and increased serum NGF levels (P<0.05, P<0.01); the protein expression of SDF-1, CXCR4 and ERK1 in ischemic brain tissue was increased (P<0.01), while LRRC4 protein expression was decreased (P<0.01)；the expression of miR-381, as well as SDF-1, CXCR4 and ERK1 mRNA in ischemic brain tissue was increased (P<0.05, P<0.01), while LRRC4 mRNA expression was decreased (P<0.01). CONCLUSIONS: EA at "Baihui" (GV 20) and "Dazhui" (GV 14) may promote the repair of neurological damage following ischemic stroke by up-regulating miR-381 to selectively inhibit LRRC4 expression, thereby activating the SDF-1/CXCR4 signaling pathway.

Ion exchange synthesis of copper-based hydroxyapatite for the catalytic degradation of phenol.

Hydroxyapatite (HAP) is a material renowned for its exceptional capabilities in adsorbing and exchanging heavy metal ions, making it a widely employed substance within the environmental domain. This study aims to present a novel material, namely copper-HAP (Cu-HAP), which was synthesized via an ion exchange method. The resulting material underwent comprehensive characterization using scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, and Brunauer-Emmett-Teller (BET) analysis. Subsequently, based on the principle of the Fenton-like oxidation reaction, the material was used for the degradation of phenol. The outcomes of the investigation revealed that the optimal preparation conditions for the catalyst were achieved at a temperature of 40 °C, a pH value of 5, and a relative dosage of Cu-HAP at 100 mg/g. Under the reaction conditions of a catalyst dosage of 2 g/L, a 30% hydrogen peroxide concentration of 30 mM, a phenol concentration of 20 mg/L, a pH value of 6, a temperature of 40 °C, and the degradation rate of phenol impressively reached 98.12%. Furthermore, the degradation rate remained at 42.31% even after five consecutive cycles, indicating the promising potential of Cu-HAP in the treatment of recalcitrant organic compounds within this field.

Study on the migration behaviour of heavy metals at the improved mine soil-plant rhizosphere interface.

With the increasing shortage of land resources and the aggravation of soil pollution in mining areas, the remediation of soil in abandoned mining areas has gradually attracted people's attention. The remediation of heavy metal contaminated soil in mining areas is the key to reduce the harm of heavy metals to the environment and human health. In this study, municipal sludge and phytoremediation technology were combined to investigate the migration and transformation of heavy metals at the soil-plant interface in improved mining areas through indoor pot experiments. The results showed that heavy metals in non-rhizosphere soil entered the rhizosphere environment with the growth of plants, leading to the increase of heavy metal content in rhizosphere soil. The cumulative amounts of Cu, Zn, Pb and Cd were 1299.32, 832.10, 347.89 and 71.34 mg/kg, respectively. The content of oxidized Cu and Zn decreased with increasing planting days, while the oxidized Pb and Cd showed an increasing trend. Under acidic conditions, H+ is easy to compete with heavy metal ions for exchangeable positions in the clay mineral layer, so that the reducible heavy metals are easy to be converted into exchangeable states. In this paper, the effects of various factors on the distribution of heavy metals were discussed by adjusting soil pH, adding humic acid and root exudates, so as to analyse the migration and transformation mechanism of heavy metals at the soil-plant interface, and provide a reliable theoretical basis for soil remediation in mining areas.

Serine peptidase Vpr forms enzymatically active fibrils outside Bacillus bacteria revealed by cryo-EM.

Bacteria develop a variety of extracellular fibrous structures crucial for their survival, such as flagella and pili. In this study, we use cryo-EM to identify protein fibrils surrounding lab-cultured Bacillus amyloiquefaciens and discover an unreported fibril species in addition to the flagellar fibrils. These previously unknown fibrils are composed of Vpr, an extracellular serine peptidase. We find that Vpr assembles into fibrils in an enzymatically active form, potentially representing a strategy of enriching Vpr activities around bacterial cells. Vpr fibrils are also observed under other culture conditions and around other Bacillus bacteria, such as Bacillus subtilis, which may suggest a general mechanism across all Bacillus bacterial groups. Taken together, our study reveals fibrils outside the bacterial cell and sheds light on the physiological role of these extracellular fibrils.

In Situ N, O Co-Doped Nanoporous Carbon Derived from Mixed Egg and Rice Waste as Green Supercapacitor.

The conversion of nitrogen-oxygen-rich biomass wastes into heteroatomic co-doped nanostructured carbons used as energy storage materials has received widespread attention. In this study, an in situ nitrogen-oxygen co-doped porous carbon was prepared for supercapacitor applications via a two-step method of pre-carbonization and pyrolytic activation using mixed egg yolk/white and rice waste. The optimal sample (YPAC-1) was found to have a 3D honeycomb structure composed of abundant micropores and mesopores with a high specific surface area of 1572.1 m2 g-1, which provided abundant storage space and a wide transport path for electrolyte ions. Notably, the specific capacitance of the constructed three-electrode system was as high as 446.22 F g-1 at a current density of 1 A g-1 and remained above 50% at 10 A g-1. The capacitance retention was 82.26% after up to 10,000 cycles. The symmetrical capacitor based on YPAC-1 with a two-electrode structure exhibited an energy density of 8.3 Wh kg-1 when the power density was 136 W kg-1. These results indicate that porous carbon materials prepared from mixed protein and carbohydrate waste have promising applications in the field of supercapacitors.

In Situ N, O-Dually Doped Nanoporous Biochar Derived from Waste Eutrophic Spirulina for High-Performance Supercapacitors.

Sustainable and high-performance energy storage materials are crucial to address global energy and environmental challenges. In this study, Spirulina platensis was used as the carbon and nitrogen source, and Spirulina-based nanoporous biochar (SNPB) was synthesized through chemical activation using KOH as the activating agent in N2 atmosphere. SNPB-800-4 was characterized by N2 adsorption-desorption and XPS, showing a high specific surface area (2923.7 m2 g-1) and abundant heteroatomic oxygen (13.78%) and nitrogen (2.55%). SNPB-800-4 demonstrated an exceptional capacitance of 348 F g-1 at a current density of 1 A g-1 and a remarkable capacitance retention of 94.14% after 10,000 cycles at a current density of 10 A g-1 in 6 M KOH. Notably, symmetric supercapacitors SNPB-800-4//SNPB-800-4 achieved the maximum energy and power densities of 17.99 Wh kg-1 and 162.48 W kg-1, respectively, at a current density of 0.5 A g-1, and still maintained 2.66 Wh kg-1 when the power density was increased to 9685.08 W kg-1 at a current density of 30 A g-1. This work provides an easily scalable and straightforward way to convert waste algae biomass into in situ N, O-dually doped biochar for ultra-high-power supercapacitors.

N/O Co-doped hierarchical nanoporous biochar derived from waste polypropylene nonwoven for high-performance supercapacitors.

How to efficiently treat municipal solid waste (MSW) has become one of the critical solutions in response to the call for "carbon neutrality". Here, the waste polypropylene nonwoven fabric of waste diapers was converted into hierarchical nanoporous biochar (HPBC) through pre-carbonization and activation processes as an ideal precursor for supercapacitors (SCs) with excellent performance. The prepared HPBC-750-4 with an ultrahigh specific surface area (3838.04 m2 g-1) and abundant heteroatomic oxygen (13.25%) and nitrogen (1.16%) codoped porous biochar structure. Given its structural advantages, HPBC-750-4 achieved a specific capacitance of 340.9 F g-1 at a current density of 1 A g-1 in a three-electrode system. Its capacitance retention rate was above 99.2% after 10 000 cycles at a current density of 10 A g-1, which indicated an excellent rate capability and long-term cycling stability. Furthermore, the HPBC-750-4//HPBC-750-4 symmetric SC exhibited a superb energy density of 10.02 W h kg-1 with a power density of 96.15 W kg-1 in a 6 M KOH electrolyte. This work not only demonstrates the enormous potential of waste polypropylene nonwoven fabric in the SC industry but also provides an economically feasible means of managing MSW.

Degradation of 2,4-DCP by immobilized laccase on modified biochar carrier.

Rape straw was used as the raw material for the biochar in this study, which was then changed using acid, alkali, and magnetic techniques. The laccase was attached using the adsorptions-crosslinking process, and the three modified biochars served as the carriers. The ideal circumstances for laccase immobilization were explored, and both biochar and immobilized laccase's characteristics were examined. The removal of 2,4-dichlorophenol (2,4-DCP) by immobilized laccase from modified biochar and its degradation products were researched. The main conclusions are as follows: the optimal concentration of glutaraldehyde (GLU) was 4%, and the pH was four, and the enzyme dosage was 1.75 mg/mL for the immobilized laccase of acid-modified biochar (SBC@LAC). The optimal concentration of GLU was 5%; the pH was four, and the enzyme dosage was 2 mg/mL for immobilized laccase from alkali-modified biochar (JBC@LAC). The optimal concentration of GLU was 5%; the pH was four, and the enzyme dosage was 1.75 mg/mL for immobilized laccase from magnetically modified biochar (CBC@LAC). SEM images could show the changes in the surface morphology of biochar caused by three modification methods. The BET results demonstrated that acid and magnetic modification increased the specific surface area of biochar, and alkali modification mainly expanded the pore size of biochar. FT-IR and XRD showed that modification and laccase loading had little effect on the structure of biochar. The stability of immobilized laccase was better than that of free laccase in acid-base, heat, and storage. Among the three modified biochar immobilized laccases, JBC@LAC showed the best acid-base stability and thermal stability, and the relative enzyme activity changed the least when pH and temperature conditions changed. The storage stability of SBC@LAC is the best. After 30 days of storage, the relative enzyme activity is still 83%. The removal rates of 2,4-DCP were 57, 99, and 63%, respectively, by SBC@LAC, JBC@LAC, and CBC@LAC. After five reuses, the removal rates of 2,4-DCP by SBC@LAC, JBC@LAC and CBC@LAC were 26, 42, and 27%, respectively. The intermediate products of 2,4-DCP degradation by immobilized laccase were p-phenol, p-benzoquinone and maleic acid.

In situ N, O co-doped porous carbon derived from antibiotic fermentation residues as electrode material for high-performance supercapacitors.

With the widespread use of antibiotics, the safe utilization of waste antibiotic fermentation residues has become an urgent issue to be resolved. In this study, in situ N, O co-doped porous carbon was prepared using fresh oxytetracycline fermentation residue under the mild activation of the green activator K2CO3. The optimal sample exhibited a 3D grid carbon skeleton structure, excellent specific surface area (SBET = 948 m2 g-1), and high nitrogen and oxygen content (N = 3.42 wt%, O = 14.86 wt%). Benefiting from its developed morphology, this sample demonstrated excellent electrochemical performance with a high specific capacitance of 310 F g-1 at a current density of 0.5 A g-1 in the three-electrode system. Moreover, it exhibited superior cycling stability with only a 5.32% loss of capacity after 10 000 cycles in 6 M KOH aqueous electrolyte. Furthermore, the symmetric supercapacitor prepared from it exhibited a maximum energy density of 7.2 W h kg-1 at a power density of 124.9 W kg-1, demonstrating its promising application prospects. This study provided a green and facile process for the sustainable and harmless treatment of antibiotic fermentation residues.