Displaying publications 61 - 80 of 95 in total

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  1. Effects of different types of biochar on methane and ammonia mitigation during layer manure composting
    Chen W, Liao X, Wu Y, Liang JB, Mi J, Huang J, et al.
    Waste Manag, 2017 Mar;61:506-515.
    PMID: 28117129 DOI: 10.1016/j.wasman.2017.01.014
    Biochar, because of its unique physiochemical properties and sorption capacity, may be an ideal amendment in reducing gaseous emissions during composting process but there has been little information on the potential effects of different types of biochar on undesired gaseous emissions. The objective of this study was to examine the ability and mechanism of different types of biochar, as co-substrate, in mitigating gaseous emission from composting of layer hen manure. The study was conducted in small-scale laboratory composters with the addition of 10% of one of the following biochars: cornstalk biochar, bamboo biochar, woody biochar, layer manure biochar and coir biochar. The results showed that the cumulative NH3 production was significantly reduced by 24.8±2.9, 9.2±1.3, 20.1±2.6, 14.2±1.6, 11.8±1.7% (corrected for initial total N) in the cornstalk biochar, bamboo biochar, woody biochar, layer manure biochar and coir biochar treatments, respectively, compared to the control. Total CH4 emissions was significantly reduced by 26.1±2.3, 15.5±2.1, 22.4±3.1, 17.1±2.1% (corrected for the initial total carbon) for cornstalk biochar, bamboo biochar, woody biochar and coir biochar treatments than the control. Moreover, addition of cornstalk biochar increased the temperature and NO3(-)-N concentration and decreased the pH, NH4(+)-N and organic matter content throughout the composting process. The results suggested that total volatilization of NH3 and CH4 in cornstalk biochar treatment was lower than the other treatments; which could be due to (i) decrease of pH and higher nitrification, (ii) high sorption capacity for gases and their precursors, such as ammonium nitrogen from composting mixtures, because of the higher surface area, pore volumes, total acidic functional groups and CEC of cornstalk biochar.
  2. Sodium butyrate reduces ammonia emissions through glutamate metabolic pathways in cecal microorganisms of laying hens
    Zhong Z, Wang C, Zhang H, Mi J, Liang JB, Liao X, et al.
    Ecotoxicol Environ Saf, 2022 Feb 14;233:113299.
    PMID: 35176673 DOI: 10.1016/j.ecoenv.2022.113299
    Ammonia emission is an important problem that needs to be solved in laying hen industries. Sodium butyrate (SB) is considered to have potential for reducing ammonia production because of its ability to improve nitrogen metabolism. In this in vitro fermentation study, we presented a correlation analysis of the metatranscriptome and metaproteome of lay hen cecal microorganisms, in order to identify important proteins and pathways involved in ammonia production reduction due to sodium butyrate supplementation. The results showed that sodium butyrate supplement decreased the production of ammonia by 26.22% as compared with the non-sodium butyrate supplementation (CK) group. The SB group exhibited a lower concentration of ammonium nitrogen (NH4+-N) and a decreased pH. Sodium butyrate promoted the uric acid concentration and lowered the uricase activity in the fermentation broth of laying hens cecal content. Notably, the 'alanine, aspartate and glutamate metabolism' category was more abundant in the SB group. The addition of sodium butyrate increased the expression of glutamate dehydrogenase (GDH) gene in cecal microbiota (e.g., Ruminococcus sp. and Bacteroides sp.) in vitro. The metaproteome analysis results showed that the expression of GDH with NADPH as coenzyme (NADPH-GDH) was up-regulated in cecal microbiota by sodium butyrate supplement. Our results indicate that sodium butyrate can affect glutamate metabolism through regulating the expression of glutamate dehydrogenase in cecal microorganisms, thereby reducing ammonia production. This study reveals that glutamate dehydrogenase-mediated glutamate metabolism play a key role in ammonia emission reduction in laying hen and provide theoretical basis for further developing ammonia production reduction approach.
  3. Fulltext Construction of recombinant Pichia pastoris strains for ammonia reduction by the gdhA and glnA regulatory genes in laying hens
    Feng K, Wang W, Rong J, Liang J, Mi J, Wu Y, et al.
    Ecotoxicol Environ Saf, 2022 Apr 01;234:113376.
    PMID: 35255249 DOI: 10.1016/j.ecoenv.2022.113376
    Ammonia emissions have become an important environmental challenge for the livestock industry. Probiotics are often used as additives to reduce ammonia, and the ammonia reduction efficiency of common probiotics is approximately 20-40%. In this study, we constructed a gdhA recombinant Pichia pastoris strain, glnA recombinant Pichia pastoris strain and gdhA-glnA Pichia pastoris recombinant strain using the gdhA and glnA genes, which have the potential function of reducing ammonia emissions. The results of in vitro fermentation showed that compared with the control, wild-type Pichia pastoris and pPICZA strains, the gdhA, glnA and gdhA-glnA recombinant strains significantly reduced ammonia emissions in laying hens (P 
  4. Fulltext Hard-Carbon Negative Electrodes from Biomasses for Sodium-Ion Batteries
    Lu B, Lin C, Xiong H, Zhang C, Fang L, Sun J, et al.
    Molecules, 2023 May 11;28(10).
    PMID: 37241775 DOI: 10.3390/molecules28104027
    With the development of high-performance electrode materials, sodium-ion batteries have been extensively studied and could potentially be applied in various fields to replace the lithium-ion cells, owing to the low cost and natural abundance. As the key anode materials of sodium-ion batteries, hard carbons still face problems, such as poor cycling performance and low initial Coulombic efficiency. Owning to the low synthesis cost and the natural presence of heteroatoms of biomasses, biomasses have positive implications for synthesizing the hard carbons for sodium-ion batteries. This minireview mainly explains the research progress of biomasses used as the precursors to prepare the hard-carbon materials. The storage mechanism of hard carbons, comparisons of the structural properties of hard carbons prepared from different biomasses, and the influence of the preparation conditions on the electrochemical properties of hard carbons are introduced. In addition, the effect of doping atoms is also summarized to provide an in-depth understanding and guidance for the design of high-performance hard carbons for sodium-ion batteries.
  5. Effect of the chlortetracycline addition method on methane production from the anaerobic digestion of swine wastewater
    Huang L, Wen X, Wang Y, Zou Y, Ma B, Liao X, et al.
    J Environ Sci (China), 2014 Oct 1;26(10):2001-6.
    PMID: 25288543 DOI: 10.1016/j.jes.2014.07.012
    Effects of antibiotic residues on methane production in anaerobic digestion are commonly studied using the following two antibiotic addition methods: (1) adding manure from animals that consume a diet containing antibiotics, and (2) adding antibiotic-free animal manure spiked with antibiotics. This study used chlortetracycline (CTC) as a model antibiotic to examine the effects of the antibiotic addition method on methane production in anaerobic digestion under two different swine wastewater concentrations (0.55 and 0.22mg CTC/g dry manure). The results showed that CTC degradation rate in which manure was directly added at 0.55mg CTC/g (HSPIKE treatment) was lower than the control values and the rest of the treatment groups. Methane production from the HSPIKE treatment was reduced (p<0.05) by 12% during the whole experimental period and 15% during the first 7days. The treatments had no significant effect on the pH and chemical oxygen demand value of the digesters, and the total nitrogen of the 0.55mg CTC/kg manure collected from mediated swine was significantly higher than the other values. Therefore, different methane production under different antibiotic addition methods might be explained by the microbial activity and the concentrations of antibiotic intermediate products and metabolites. Because the primary entry route of veterinary antibiotics into an anaerobic digester is by contaminated animal manure, the most appropriate method for studying antibiotic residue effects on methane production may be using manure from animals that are given a particular antibiotic, rather than adding the antibiotic directly to the anaerobic digester.
  6. Fulltext Different Concentrations of Doxycycline in Swine Manure Affect the Microbiome and Degradation of Doxycycline Residue in Soil
    Yan Q, Li X, Ma B, Zou Y, Wang Y, Liao X, et al.
    Front Microbiol, 2018;9:3129.
    PMID: 30619199 DOI: 10.3389/fmicb.2018.03129
    Antibiotic residues that enter the soil through swine manure could disturb the number, community structure and functions of microbiota which could also degrade antibiotics in soil. Five different concentrations of doxycycline (DOX) incorporated into swine manure were added to soil to explore the effects of DOX on microbiota in soil and degradation itself. The results showed that the soil microbiome evolved an adaptation to the soil containing DOX by generating resistance genes. Moreover, some of the organisms within the soil microbiome played crucial roles in the degradation of DOX. The average degradation half-life of DOX in non-sterile groups was 13.85 ± 0.45 days, which was significantly shorter than the 29.26 ± 0.98 days in the group with sterilized soil (P < 0.01), indicating that the soil microbiome promoted DOX degradation. DOX addition affected the number of tetracycline resistance genes, depending on the type of gene and the DOX concentration. Among these genes, tetA, tetM, tetW, and tetX had significantly higher copy numbers when the concentration of DOX was higher. In contrast, a lower concentration of DOX had an inhibitory effect on tetG. At the same time, the microbial compositions were affected by the initial concentration of DOX and the different experimental periods. The soil chemical indicators also affected the microbial diversity changes, mainly because some microorganisms could survive in adversity and become dominant bacterial groups, such as the genera Vagococcus and Enterococcus (which were associated with electrical conductivity) and Caldicoprobacter spp. (which were positively correlated with pH). Our study mainly revealed soil microbiota and DOX degradation answered differently under variable concentrations of DOX mixed with swine manure in soil.
  7. Metabonomics reveals an alleviation of fitness cost in resistant E. coli competing against susceptible E. coli at sub-MIC doxycycline
    Wen X, Cao J, Mi J, Huang J, Liang J, Wang Y, et al.
    J Hazard Mater, 2021 03 05;405:124215.
    PMID: 33109407 DOI: 10.1016/j.jhazmat.2020.124215
    High concentrations of antibiotics may induce bacterial resistance mutations and further lead to fitness costs by reducing growth of resistant bacteria. However, antibiotic concentrations faced by bacteria are usually low in common environments, which leads to questions about how resistant bacteria with fitness costs regulate metabolism to coexist or compete with susceptible bacteria during sublethal challenge. Our study revealed that a low proportion (< 15%) of resistant bacteria coexisted with susceptible bacteria due to the fitness cost without doxycycline. However, the cost for the resistant strain decreased at a doxycycline concentration of 1 mg/L and even disappeared when the doxycycline concentration was 2 mg/L. Metabonomics analysis revealed that bypass carbon metabolism and biosynthesis of secondary metabolites were the primary metabolic pathways enriching various upregulated metabolites in resistant bacteria without doxycycline. Moreover, the alleviation of fitness cost for resistant bacteria competed with susceptible bacteria at 1 mg/L doxycycline was correlated with the downregulation of the biomarkers pyruvate and pilocarpine. Our study offered new insight into the metabolic mechanisms by which the fitness cost of resistant mutants was reduced at doxycycline concentrations as low as 1 mg/L and identified various potential metabolites to limit the spread of antimicrobial resistance in the environment.
  8. Fulltext Changes in the Carbon Metabolism of Escherichia coli During the Evolution of Doxycycline Resistance
    Yang Y, Mi J, Liang J, Liao X, Ma B, Zou Y, et al.
    Front Microbiol, 2019;10:2506.
    PMID: 31736928 DOI: 10.3389/fmicb.2019.02506
    Despite our continuous improvement in understanding the evolution of antibiotic resistance, the changes in the carbon metabolism during the evolution of antibiotic resistance remains unclear. To investigate the evolution of antibiotic resistance and the changes in carbon metabolism under antibiotic pressure, Escherichia coli K-12 was evolved for 38 passages under a concentration gradient of doxycycline (DOX). The 0th-passage sensitive strain W0, the 20th-passage moderately resistant strain M20, and the 38th-passage highly resistant strain E38 were selected for the determination of biofilm formation, colony area, and carbon metabolism levels, as well as genome and transcriptome sequencing. The MIC of DOX with E. coli significantly increased from 4 to 96 μg/ml, and the IC50 increased from 2.18 ± 0.08 to 64.79 ± 0.75 μg/ml after 38 passages of domestication. Compared with the sensitive strain W0, the biofilm formation amount of the resistant strains M20 and E38 was significantly increased (p < 0.05). Single-nucleotide polymorphisms (SNPs) were distributed in antibiotic resistance-related genes such as ribosome targets, cell membranes, and multiple efflux pumps. In addition, there were no mutated genes related to carbon metabolism. However, the genes involved in the biosynthesis of secondary metabolites and carbon metabolism pathway were downregulated, showing a significant decrease in the metabolic intensity of 23 carbon sources (p < 0.05). The results presented here show that there may be a correlation between the evolution of E. coli DOX resistance and the decrease of carbon metabolism, and the mechanism was worthy of further research, providing a theoretical basis for the prevention and control of microbial resistance.
  9. Influence and characteristics of Bacillus stearothermophilus in ammonia reduction during layer manure composting
    Wang Y, Bi L, Liao Y, Lu D, Zhang H, Liao X, et al.
    Ecotoxicol Environ Saf, 2019 Sep 30;180:80-87.
    PMID: 31078019 DOI: 10.1016/j.ecoenv.2019.04.066
    Ammonia emissions is an important issue during composting because it can cause secondary pollution and a significant of nitrogen loss. Based on research adding Bacillus stearothermophilus can reduce ammonia emissions during composting because it can use sugar in organic matter fermentation to produce organic acids over 50 °C. This study conducted the batch experiments by adding different concentrations of Bacillus stearothermophilus to reduce the ammonia emissions and find out its characteristic during layer manure composting by using an aerobic composting reactor with sawdust as a bulking agent. The results show that the application of Bacillus stearothermophilus can accelerate the rate of temperature and significantly decrease pH, the warming period was 2 days in the treatment with Bacillus stearothermophilus, while it was 4 days in the treatment without Bacillus stearothermophilus. Ammonia emissions were mainly occurred in warming and high temperature period during composting. The ammonia emissions in the treatment with 8.00 g/kg initial Bacillus stearothermophilus were significantly lower than the other lower Bacillus stearothermophilus treatment and control during composting (p  0.05). MiSeq System Sequencing results find that the addition of Bacillus stearothermophilus changed the bacterial community structure under warming and high-temperature periods during composting, increased the relative abundance of lactic acid bacillus and nitrification bacteria. Therefore, the reason for the low ammonia emission in 8.00 g/kg initial Bacillus stearothermophilus treatments might be not only due to the Bacillus stearothermophilus itself, but also Bacillus stearothermophilus can change the indigenous microorganism community, including increase the relative content of lactic acid Bacillus and nitrification bacteria, thus reducing the pH and promoting nitrification, and reducing ammonia emissions.
  10. Heterologous expression of the tetracycline resistance gene tetX to enhance degradability and safety in doxycycline degradation
    Wen X, Huang J, Cao J, Xu J, Mi J, Wang Y, et al.
    Ecotoxicol Environ Saf, 2020 Mar 15;191:110214.
    PMID: 31968275 DOI: 10.1016/j.ecoenv.2020.110214
    Microbial remediation has the potential to inexpensively yet effectively decontaminate and restore contaminated environments, but the virulence of pathogens and risk of resistance gene transmission by microorganisms during antibiotic removal often limit its implementation. Here, a cloned tetX gene with clear evolutionary history was expressed to explore doxycycline (DOX) degradation and resistance variation during the degradation process. Phylogenetic analysis of tetX genes showed high similarity with those of pathogenic bacteria, such as Riemerella sp. and Acinetobacter sp. Successful tetX expression was performed in Escherichia coli and confirmed by SDS-PAGE and Western blot. Our results showed that 95.0 ± 1.0% of the DOX (50 mg/L) was degraded by the recombinant strain (ETD-1 with tetX) within 48 h, which was significantly higher than that for the control (38.9 ± 8.7%) and the empty plasmid bacteria (8.8 ± 5.1%) (P  0.05). The efficient and safe DOX-degrading capacity of the recombinant strain ETD-1 makes it valuable and promising for antibiotic removal in the environment.
  11. Occurrence and contamination profiles of antibiotic resistance genes from swine manure to receiving environments in Guangdong Province southern China
    Wen X, Mi J, Wang Y, Ma B, Zou Y, Liao X, et al.
    Ecotoxicol Environ Saf, 2019 May 30;173:96-102.
    PMID: 30769208 DOI: 10.1016/j.ecoenv.2019.02.023
    Livestock farms are commonly regarded as the main sources of antibiotic resistance genes (ARGs), emerging pollutants with potential implications for human health, in the environment. This study investigated the occurrence and contamination profiles of nine ARGs of three types from swine manure to receiving environments (soil and water) in Guangdong Province, southern China. All ARGs occurred in 100% of swine manure samples. Moreover, the absolute concentration of total ARGs varied from 3.01 × 108 to 7.18 × 1014 copies/g, which was significantly higher than that in wastewater and manured soil (p  0.05). However, the number of ARGs (ermB, qnrS, acc(6')-Ib, tetM, tetO and tetQ) decreased but were not eliminated by wastewater treatment components (p 
  12. Different methods of incorporating ciprofloxacin in soil affect microbiome and degradation of ciprofloxacin residue
    Liu L, Mi J, Wang Y, Zou Y, Ma B, Liao X, et al.
    Sci Total Environ, 2018 Apr 01;619-620:1673-1681.
    PMID: 29056384 DOI: 10.1016/j.scitotenv.2017.10.133
    Antibiotic residues in swine manure when entered the soil would most likely affect the complex composition and functions of the soil microbiome, which is also responsible for degrading these antibiotics. Three different methods of adding ciprofloxacin (CIP), a common antibiotic used in the swine industry, to the soil were used to investigate the effects of CIP on the soil microbiome and the degradation of CIP. Results of the study showed that the microbiome could promote the degradation of CIP in the soil when CIP was incorporated into the soil together with manure. However, the CIP degradation time was prolonged when adding the manure of swine fed with diet containing CIP in the soil. All treatments did not affect the copy number of the resistance genes, except for aac(6')-Ib-cr, as compared with the initial numbers of each treatment. MiSeq Illumina sequencing and Biolog-ECO microplates results showed that CIP had a significant effect on the abundance, structure, and function of the soil microbiome, but different addition methods resulted in distinct effects. Results of the present study demonstrated that the microbiome and fate of CIP responded differently to the different methods of adding CIP to the soil.
  13. Fulltext Self-medication in Chinese residents and the related factors of whether or not they would take suggestions from medical staff as an important consideration during self-medication
    Ge P, Li Q, Dong M, Niu Y, Han X, Xiong P, et al.
    Front Public Health, 2022;10:1074559.
    PMID: 36620260 DOI: 10.3389/fpubh.2022.1074559
    OBJECTIVE: To investigate the status of Chinese residents' self-medication behavior and the important factors to consider when purchasing OTC drugs, and to explore the related factors of the possibility that Chinese residents take medical staff's suggestions as important factors to consider when purchasing OTC drugs.

    STUDY DESIGN: A cross-sectional survey.

    METHODS: A questionnaire was developed for exploring the sociodemographic characteristics of the respondents, their self-medication status, and important considerations. The questionnaire includes several scales including Health Literacy Scale-Short Form (HLS-SF), EQ-5D Visual Analog Scale (EQ-5D-VAS), Big Five Inventary-10 Items (BFI-10), and New General Self Efficacy Scale (NGSES). After carrying out a multi-stage sampling method, the questionnaire was conducted nationwide from July 10 to September 15, 2021. Next, descriptive statistics were conducted to analyze the general features. Logistic regression was then used to analyze the related factors of the possibility that the respondents took the suggestions of medical staff as an important consideration when purchasing OTC drugs.

    RESULTS: Nine thousand two hundred fifty-six qualified questionnaires were received. 99.06% of Chinese adults had self-medication behaviors. The types of OTC drugs purchased most by the respondents were NSAIDs (5,421/9,256 people, 58.57%) and vitamins/minerals (4,851/9,256 people, 52.41%). 86.2% of the respondents took the suggestions of medical staff as an important consideration when purchasing OTC drugs. The results of multi-factor logistic regression showed that women, those living in the central and western regions of China, those suffering from chronic diseases, those with high agreeableness, high conscientiousness, high neuroticism and openness, high health literacy, high EQ-5D-VAS, and those with high self-efficacy are more likely to take medical staff's suggestions as important factors to consider.

    CONCLUSION: The vast majority of Chinese adults have self-medication behavior. Important considerations when purchasing OTC drugs include medical staff's suggestions, drug safety and drug efficacy. Whether residents take the suggestions of medical staff as an important consideration is related to their sociological characteristics, agreeableness, conscientiousness, neuroticism, openness, health literacy, self-assessment health status, and self-efficacy. When purchasing and using OTC drugs, residents should carefully listen to the suggestions from medical staff. They should also carefully consider their own conditions before buying OTC drugs.

  14. Comparison of oxytetracycline degradation behavior in pig manure with different antibiotic addition methods
    Wang Y, Chen G, Liang J, Zou Y, Wen X, Liao X, et al.
    Environ Sci Pollut Res Int, 2015 Dec;22(23):18469-76.
    PMID: 26278905 DOI: 10.1007/s11356-015-5170-7
    Using manure collected from swine fed with diet containing antibiotics and antibiotic-free swine manure spiked with antibiotics are the two common methods of studying the degradation behavior of veterinary antibiotic in manure in the environment. However, few studies had been conducted to co-compare these two different antibiotic addition methods. This study used oxytetracycline (OTC) as a model antibiotic to study antibiotic degradation behavior in manure under the above two OTC addition methods. In addition, the role of microorganisms present in the manure on degradation behavior was also examined. The results showed that degradation half-life of OTC in manure from swine fed OTC (9.04 days) was significantly shorter than that of the manure directly treated with OTC (9.65 days). Concentration of 4-epi-OTC in manure from swine fed OTC peaked earlier than that in manure spiked with OTC, and the degradation rates of 4-epi-OTC and α-apo-OTC in the manure from swine fed OTC were faster, but the peak concentrations were lower, than those in manure spiked with OTC. Bacterial diversity and relative abundance of Bacillus cereus data demonstrated that sterilization of the manure before experiment significantly decreased OTC degradation rate in both of the addition methods. Results of the present study demonstrated that the presence of the metabolites (especially 4-epi-OTC) and microorganisms had significant influence on OTC degradation.
  15. Fulltext A cryptic species of the Tylonycteris pachypus complex (Chiroptera: Vespertilionidae) and its population genetic structure in southern China and nearby regions
    Huang C, Yu W, Xu Z, Qiu Y, Chen M, Qiu B, et al.
    Int J Biol Sci, 2014;10(2):200-11.
    PMID: 24550688 DOI: 10.7150/ijbs.7301
    Three distinct bamboo bat species (Tylonycteris) are known to inhabit tropical and subtropical areas of Asia, i.e., T. pachypus, T. robustula, and T. pygmaeus. This study performed karyotypic examinations of 4 specimens from southern Chinese T. p. fulvidus populations and one specimen from Thai T. p. fulvidus population, which detected distinct karyotypes (2n=30) compared with previous karyotypic descriptions of T. p. pachypus (2n=46) and T. robustula (2n=32) from Malaysia. This finding suggested a cryptic Tylonycteris species within T. pachypus complex in China and Thailand. Morphometric studies indicated the difficulty in distinguishing the cryptic species and T. p. pachypus from Indonesia apart from the external measurements, which might be the reason for their historical misidentification. Based on 623 bp mtDNA COI segments, a phylogeographic examination including T. pachypus individuals from China and nearby regions, i.e., Vietnam, Laos, and Cambodia, was conducted to examine the population genetic structure. Genealogical and phylogeographical results indicated that at least two diverged lineages existed in these regions (average 3.4 % of Kimura 2-parameter distances) and their population structure did not match the geographic pattern. These results suggested that at least two historical colonizations have occurred by the cryptic species. Furthermore, through integration of traditional and geometric morphological results, morphological differences on zygomatic arches, toothrows and bullae were detected between two lineages in China. Given the similarity of vegetation and climate of Guangdong and Guangxi regions, we suggested that such differences might be derived from their historical adaptation or distinct evolutionary history rather than the differences of habitats they occurred currently.
  16. Enzymatic conversion of pretreated lignocellulosic biomass: A review on influence of structural changes of lignin
    Sheng Y, Lam SS, Wu Y, Ge S, Wu J, Cai L, et al.
    Bioresour Technol, 2021 Mar;324:124631.
    PMID: 33454445 DOI: 10.1016/j.biortech.2020.124631
    The demands of energy sustainability drive efforts to bio-chemical conversion of biomass into biofuels through pretreatment, enzymatic hydrolysis, and microbial fermentation. Pretreatment leads to significant structural changes of the complex lignin polymer that affect yield and productivity of the enzymatic conversion of lignocellulosic biomass. Structural changes of lignin after pretreatment include functional groups, inter unit linkages and compositions. These changes influence non-productive adsorption of enzyme on lignin through hydrophobic interaction and electrostatic interaction as well as hydrogen bonding. This paper reviews the relationships between structural changes of lignin and enzymatic hydrolysis of pretreated lignocellulosic biomass. The formation of pseudo-lignin during dilute acid pretreatment is revealed, and their negative effect on enzymatic hydrolysis is discussed.
  17. Advanced nanocellulose-based gas barrier materials: Present status and prospects
    Wu Y, Liang Y, Mei C, Cai L, Nadda A, Le QV, et al.
    Chemosphere, 2022 Jan;286(Pt 3):131891.
    PMID: 34416587 DOI: 10.1016/j.chemosphere.2021.131891
    Nanocellulose based gas barrier materials have become an increasingly important subject, since it is a widespread environmentally friendly natural polymer. Previous studies have shown that super-high gas barrier can be achieved with pure and hierarchical nanocellulose films fabricated through simple suspension or layer-by-layer technique either by itself or incorporating with other polymers or nanoparticles. Improved gas barrier properties were observed for nanocellulose-reinforced composites, where nanocellulose partially impermeable nanoparticles decreased gas permeability effectively. However, for nanocellulose-based materials, the higher gas barrier performance is jeopardized by water absorption and shape deformation under high humidity conditions which is a challenge for maintaining properties in material applications. Thus, numerous investigations have been done to solve the problem of water absorption in nanocellulose-based materials. In this literature review, gas barrier properties of pure, layer-by-layer and composite nanocellulose films are investigated. The possible theoretical gas barrier mechanisms are described, and the prospects for nanocellulose-based materials are discussed.
  18. Physico-chemical and biological remediation techniques for the elimination of endocrine-disrupting hazardous chemicals
    Wu Y, Liu Y, Kamyab H, Rajasimman M, Rajamohan N, Ngo GH, et al.
    Environ Res, 2023 Sep 01;232:116363.
    PMID: 37295587 DOI: 10.1016/j.envres.2023.116363
    Due to their widespread occurrence and detrimental effects on human health and the environment, endocrine-disrupting hazardous chemicals (EDHCs) have become a significant concern. Therefore, numerous physicochemical and biological remediation techniques have been developed to eliminate EDHCs from various environmental matrices. This review paper aims to provide a comprehensive overview of the state-of-the-art remediation techniques for eliminating EDHCs. The physicochemical methods include adsorption, membrane filtration, photocatalysis, and advanced oxidation processes. The biological methods include biodegradation, phytoremediation, and microbial fuel cells. Each technique's effectiveness, advantages, limitations, and factors affecting their performance are discussed. The review also highlights recent developments and future perspectives in EDHCs remediation. This review provides valuable insights into selecting and optimizing remediation techniques for EDHCs in different environmental matrices.
  19. A novel porous lignocellulosic standing hierarchical hydroxyapatite for enhanced aqueous copper(II) removal
    Liang Y, Jin X, Xu X, Wu Y, Ghfar AA, Lam SS, et al.
    Sci Total Environ, 2024 Feb 20;912:168873.
    PMID: 38016558 DOI: 10.1016/j.scitotenv.2023.168873
    Potentially toxic metal-polluted water resources are a heavily discussed topic the pollution by potentially toxic metals can cause significant health risks. Nanomaterials are actively developed towards providing high specific surface area and creating active adsorption sites for the treatment and remediation of these polluted waters. In an effort to tackle the limitations of conventional type adsorbents, nano-hydroxyapatite (HAp) was developed in this study by in situ generation onto wood powder, resulting in the formation of uniform hybrid powder (HAp@wood composite) structure consisting of HAp nanoparticles that showed the removal efficiency up to 80 % after 10 min; the maximum adsorption capacity for Cu(II) ions (98.95 mg/g-HAp) was higher compared to agglomerated nano-HAp (72.85 mg/g-HAp). The adsorption capacity of Cu(II) remained stable (89.85-107.66 mg/g-HAp) during the four adsorption-desorption cycles in multi-component system, thereby demonstrating high selectivity for Cu(II). This approach of using nanoparticle is relatively simple yet effective in improving the adsorption of potentially toxic metals and the developed approach can be used to develop advanced nanocomposites in commercial wastewater treatment.
  20. An Improved Soft Subspace Clustering Algorithm Based on Particle Swarm Optimization for MR Image Segmentation
    Ling L, Huang L, Wang J, Zhang L, Wu Y, Jiang Y, et al.
    Interdiscip Sci, 2023 Dec;15(4):560-577.
    PMID: 37160860 DOI: 10.1007/s12539-023-00570-2
    Soft subspace clustering (SSC), which analyzes high-dimensional data and applies various weights to each cluster class to assess the membership degree of each cluster to the space, has shown promising results in recent years. This method of clustering assigns distinct weights to each cluster class. By introducing spatial information, enhanced SSC algorithms improve the degree to which intraclass compactness and interclass separation are achieved. However, these algorithms are sensitive to noisy data and have a tendency to fall into local optima. In addition, the segmentation accuracy is poor because of the influence of noisy data. In this study, an SSC approach that is based on particle swarm optimization is suggested with the intention of reducing the interference caused by noisy data. The particle swarm optimization method is used to locate the best possible clustering center. Second, increasing the amount of geographical membership makes it possible to utilize the spatial information to quantify the link between different clusters in a more precise manner. In conclusion, the extended noise clustering method is implemented in order to maximize the weight. Additionally, the constraint condition of the weight is changed from the equality constraint to the boundary constraint in order to reduce the impact of noise. The methodology presented in this research works to reduce the amount of sensitivity the SSC algorithm has to noisy data. It is possible to demonstrate the efficacy of this algorithm by using photos with noise already present or by introducing noise to existing photographs. The revised SSC approach based on particle swarm optimization (PSO) is demonstrated to have superior segmentation accuracy through a number of trials; as a result, this work gives a novel method for the segmentation of noisy images.
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