Because of the incomparable merits （nontoxicity, non-remainder, fast transfer mass） of supercritical carbon dioxide fluid technique（SC-CO2）, it was used to developed a series of novel biodegradable tissue engineer...Because of the incomparable merits （nontoxicity, non-remainder, fast transfer mass） of supercritical carbon dioxide fluid technique（SC-CO2）, it was used to developed a series of novel biodegradable tissue engineering scaffold materials in this research. The novel PLA/chitosan composite materials could be molded to different shapes, and the porosity of the materials were over 200 lam and connected. Chondrocyte cultivation, subcutaneous and intramuscular implantation were mainly discussed this paper. The results showed that the cells could well adhere, grow and multiplicate on the surface of the materials, which indicated good biocompatibility of the composite materials. The plantation test revealed that the PLA materials had already dismissed 2 month late in the body, while the composite materials could still keep certain strength and shape, and the most important things is the response of the tissue toward the implanted PLA/chitosan composite materials was mild and had far less inflammation than PLA materials. 8 to 16 weeks later, fiber membrane was stable; degradation of the materials was seen clear and tissue had already spread into it.展开更多
CRISPR-Cas system permanently deletes any harmful gene-of-interest to combat cancer growth.Chitosan(CS)is a potential cancer therapeutic that mediates via PI3K/Akt/mTOR,MAPK and NF-kβsignaling pathway modulation.CS a...CRISPR-Cas system permanently deletes any harmful gene-of-interest to combat cancer growth.Chitosan(CS)is a potential cancer therapeutic that mediates via PI3K/Akt/mTOR,MAPK and NF-kβsignaling pathway modulation.CS and its covalent derivatives have been designed as nanocarrier of CRISPR-Cas9 alone(plasmid or ribonucleoprotein)or in combination with chemical drug for cancer treatment.The nanocarrier was functionalized with polyethylene glycol(PEG),targeting ligand,cell penetrating ligand and its inherent positive zeta potential to mitigate premature clearance and particulate aggregation,and promote cancer cell/nucleus targeting and permeabilization to enable CRISPR-Cas9 acting on the host DNA.Different physicochemical attributes are required for the CS-based nanocarrier to survive from the administration site,through the systemic circulation-extracellular matrix-mucus-mucosa axis,to the nucleus target.CRISPR-Cas9 delivery is met with heterogeneous uptake by the cancer cells.Choice of excipients such as targeting ligand and PEG may be inappropriate due to lacking overexpressed cancer receptor or availability of excessive metabolizing enzyme and immunoglobulin that defies the survival and action of these excipients rendering nanocarrier fails to reach the target site.Cancer omics analysis should be implied to select excipients which meet the pathophysiological needs,and chitosan nanocarrier with a“transformative physicochemical behavior”is essential to succeed CRISPR-Cas9 delivery.展开更多
Biodegradable plastics are types of plastics that can decompose into water and carbon dioxide the actions of living organisms,mostly by bacteria.Generally,biodegradable plastics are obtained from renewable raw materia...Biodegradable plastics are types of plastics that can decompose into water and carbon dioxide the actions of living organisms,mostly by bacteria.Generally,biodegradable plastics are obtained from renewable raw materials,microorganisms,petrochemicals,or a combination of all three.This study aims to develop an innovative bioplastic by combining chitosan and lignin.Bioplastic was prepared by casting method and characterized by measuring the mechanical properties like tensile strength,Young’smodulus,and elongation at break.The chemical structure,together with the interactions among chitosan and lignin and the presence of new chemical bonds,were evaluated by FTIR,while the thermal properties were assessed by thermogravimetric analysis.The water vapor permeability,tests and transparency as well as biodegradability,were also carried out.The results show a tensile strength value of 34.82 MPa,Young’s modulus of 18.54 MPa,and elongation at a break of 2.74%.Moreover,the interaction between chitosan and lignin affects the intensity of the absorption peak,leading to reduced transparency and increased thermal stability.The chitosan/lignin interactions also influence the crystalline size,making it easier to degrade andmore flexible rather than rigid.The contact angle shows the bioplastic’s ability to resist water absorption for 4minutes.In the biodegradation test,the sample began to degrade after 30 days of soil burial test observation.展开更多
Chitosan(CS),a natural polymer derived from chitin found in the exoskeletons of crustaceans,has garnered significant interest in the pharmaceutical field due to its unique properties,including biocompatibility and bio...Chitosan(CS),a natural polymer derived from chitin found in the exoskeletons of crustaceans,has garnered significant interest in the pharmaceutical field due to its unique properties,including biocompatibility and biodegradability.In recent years,various studies have reported that CS can affect drug bioavailability,and interestingly,it works as an oral absorption enhancer and inhibitor.This review offers an in-depth analysis of the mechanisms underlying such a phenomenon and supports its application as a pharmaceutical excipient.CS enhances oral drug absorption through various mechanisms,such as interaction with the intestinal mucosa,tight junction modulation,inhibition of efflux transporters,enzyme inhibition,solubility and stability enhancement,and complexation.On the other side,CS exhibits the ability to inhibit the absorption of certain drugs by adsorbing to lipids and sterols,modulating bile acids and gut microbiota,altering drug-cell interaction at the polar interface,and mucus-mediated entrapment and interference.Future potential pharmaceutical research in this field includes elucidating the underneath absorption relevant mechanisms,rational use in formulations as excipient,exploring functional CS derivatives,and developing CS-based drug delivery systems.This comprehensive review highlights CS's versatile and significant role in enhancing and inhibiting oral drug absorption,providing insights into the complexities of drug delivery and the potential of CS to improve therapeutic outcomes.展开更多
Proton exchange membrane(PEM)is an integral component in fuel cells which enables proton transport for efficient energy conversion.Sulfonated Polyether Ether Ketone(SPEEK)has emerged as a cost-effective option with no...Proton exchange membrane(PEM)is an integral component in fuel cells which enables proton transport for efficient energy conversion.Sulfonated Polyether Ether Ketone(SPEEK)has emerged as a cost-effective option with non-fluorinated aromatic backbones for Proton Exchange Membrane Fuel Cell(PEMFC)applications,even though it exhibits lower proton conductivity compared to Nafion.This work aims to study the influence of Sulfonated Chitosan(SCS)concentrations on proton conductivity of SPEEK-based PEM at room temperature.SPEEK was synthesized using a sulfonation process with concentrated sulfuric acid at room temperature.SCS was synthesized via reflux of CS and 1.2 M H2SO4 with a ratio of 1:35(w/v)at 90℃ for 30 min.The composite membranes of SPEEK-SCS were formed with four different SCS concentrations,using the solution castingmethod,andDimethyl Sulfoxide(DMSO)was used as a solvent.The composite membranes synthesized include pure SPEEK(S0),SPEEK with 1%SCS(S1),SPEEK with 2%SCS(S2),and SPEEK with 3%SCS(S3).Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),water uptake,degree of swelling,Ionic exchange capacity(IEC)with Electrochemical impedance spectroscopy(EIS)were used to characterize the composite membranes in terms of composition,crystallinity,water absorption,dimensional changes,number of exchangeable ions in membranes,and proton conductivity,respectively.Notably,S3 had the highest water uptake and the lowest degree of swelling.S2 had the highest proton conductivity among the SPEEK-SCS composite membranes at room temperature with 3.44×10^(−2) Scm^(-1).展开更多
Many adsorbents have been developed for uranium recovery to ensure global energy and environmental security.However,most reported adsorbents involve complex preparation process and rely heavily on petrochemical feedst...Many adsorbents have been developed for uranium recovery to ensure global energy and environmental security.However,most reported adsorbents involve complex preparation process and rely heavily on petrochemical feedstocks,which undoubtedly increases carbon emissions from production in the nuclear industry.Here,a biomass aerogel(CS-BT)is prepared by the facile cross-linking of chitosan and bayberry tannins with glutaraldehyde.U(Ⅵ)can be adsorbed by hydroxyl groups on CS-BT aerogel via chelation,and the maximum adsorption capacity of the obtained aerogel to U(Ⅵ)is 140 mg·g^(-1)and the removal rate reaches up to 99%(at 298.15 K,pH=5.0).The pseudo-second-order kinetics model and Freundlich model can better match the adsorption process of CS-BT aerogel,implying that its adsorption is a chemical adsorption process dominated by multilayer adsorption.The thermodynamic results show that the adsorption process of U(Ⅵ)by CS-BT aerogel is spontaneous and exothermic.Hence,our biomass aerogel can effectively extract uranium from water,contributing to the sustainable development of the nuclear industry.展开更多
The cultivation of Soledad pepper(Capsicum annuum L.)is essential in Oaxaca and Veracruz,but it faces issues with pests and diseases,which affect yield and cause economic losses.To mitigate these impacts,farmers have ...The cultivation of Soledad pepper(Capsicum annuum L.)is essential in Oaxaca and Veracruz,but it faces issues with pests and diseases,which affect yield and cause economic losses.To mitigate these impacts,farmers have started using biostimulants such as chitosan and plant growth promoting bacteria instead of agrochemicals due to their environmental and health benefits.This study evaluated the effect of Bacillus subtilis and chitosan,both individually and combined,on the growth,yield,and fruit quality of Soledad pepper under greenhouse conditions.Four treatments were applied at different stages of the crop cycle:Q(Chitosan),BS(Bacillus subtilis),Q+BS(Chitosan+Bacillus subtilis),and T(Control).The results showed that the combination of chitosan and Bacillus subtilis significantly improved plant growth,especially in height and stem diameter.The chitosan treatment produced the highest number of fruits and plant weight,while the combination of chitosan and Bacillus subtilis enhanced fruit quality,increasing characteristics such as size,weight,pericarp thickness,and physicochemical parameters,notably in brix degrees,citric acid percentage,and pH,outperforming the individual treatments and the control.展开更多
Flubendiamide is a commonly used pesticide with low water solubility and a high organic carbon sorption constant,causing it to adhere to soil particles and negatively impact soil ecosystems.First,chili plant stems,typ...Flubendiamide is a commonly used pesticide with low water solubility and a high organic carbon sorption constant,causing it to adhere to soil particles and negatively impact soil ecosystems.First,chili plant stems,typically discarded after the harvest season,represent an abundant local biomass resource with significant potential for utilization,and were converted into biochar through pyrolysis.Here,we describe the synthesis of biochar modified with iron and chitosan to increase the diversity of functions and surface functional groups of biochar.The resulting chitosan-modified magnetic biochar(CMBC)presents a full range of functional groups of chitosan and iron oxide as shown by Fourier-transform infrared spectroscopy.The correlation between flubendiamide concentration and the dose of biochar on adsorption was explored.The flubendiamide adsorption efficiency of CMBC(1%mass ratio of soil)reached 68.03%in 90 min.The highest adsorption capacity achieved was 0.95 mg·g^(−1).The flubendiamide adsorption mechanism by CMBC can be described with a pseudo-second-order kinetic model.The experiment data closely fit a Freundlich isotherm model(R^(2)=0.998),and the low residual sum of squares values demonstrate the high model applicability.In this study,we present a comprehensive overview of pesticides,alongside kinetic and isotherm model studies of flubendiamide adsorption by CMBC.We emphasize the potential of modified biochar to enhance environmental remediation applications.展开更多
Melt blending of biodegradable polyesters such as poly(lactic acid)(PLA)and poly(butylene adipate co-terephthalate)(PBAT)with a compatibilizer and natural filler offers a chance to develop biodegradable biocomposites ...Melt blending of biodegradable polyesters such as poly(lactic acid)(PLA)and poly(butylene adipate co-terephthalate)(PBAT)with a compatibilizer and natural filler offers a chance to develop biodegradable biocomposites with improved performance.In this study,we examined how PLA/PBAT blends behave during ultimate biodegradation(mineralization),both with and without compatibilizer and algae as a reinforcement,under controlled composting conditions using carbon dioxide(CO_(2))respirometry techniques.Throughout the biodegradation process,the disintegration behaviour,thermal,chemical,and morphological properties of test samples before and after biodegradation were analyzed using FTIR,TGA,DSC,and SEM techniques.The results from CO_(2)biodegradation showed that PLA/PBAT blend exhibits a higher rate of biodegradation compared to neat PLA and PBAT.The addition of algae to a compatibilized PLA/PBAT blend showed an enhanced biodegradation rate due to hydrolytic cleavage and microbial assimilation.This was further supported by the disintegration test,where algae-reinforced composites showed fragmentation within 30 days.FTIR,TGA and SEM analysis revealed the structural changes that occurred during biodegradation,highlighting the role of algae in affecting the thermal stability and surface morphology.After the compost biodegradation step,eco-toxicity seed germination was conducted on the test samples.Plant seed germination test results confirmed that all test samples achieved maximumgermination.This indicates there were no toxic residues,suggesting that the degraded materials are environmentally safe.Overall,this study contributes to the understanding of biodegradation mechanisms and the ecological impact of bio-based polymer composites as eco-friendly materials and products.展开更多
This study presents a thorough investigation into the use of single and twin-tailed cationic and anionic surfactant-modified chitosan(SMCS)hydrogel beads as effective adsorbents for the elimination of hazardous polycy...This study presents a thorough investigation into the use of single and twin-tailed cationic and anionic surfactant-modified chitosan(SMCS)hydrogel beads as effective adsorbents for the elimination of hazardous polycyclic aromatic hydrocarbons(PAHs)from aqueous solutions.The Chitosan(CS)hydrogel beads were modified with single/twin-tailed anionic surfactants,sodium dodecyl sulfate(SDS)and sodium bis(2-ethylhexyl)sulfosuccinate(AOT),and cationic surfactants,dodecyltrimethylammonium bromide(DTAB)and didodecyldimethylammonium bromide(DDAB),to enhance their adsorption capacity of PAHs.The CS and SMCS beads were evaluated for their structural,mechanical,and adsorption properties using a range of techniques,including infrared spectroscopy(IR),energy-dispersive X-ray spectroscopy(EDX),rheometry,and field emission scanning electron microscopy(FESEM).Adsorption experiments of naphthalene(Nap),acenaphthene(Ace),and phenanthrene(Phe)on SMCS beads demonstrate that they have significantly higher adsorption capacities than CS beads,due to increase in hydrophobic interactions.Adsorption capacity followed the trend,Phen>Ace>Nap for all the beads revealing that twin-tailed SMCS bead possess much higher adsorption capacities(Qmax)compared to single-tailed SMCS beads.For twin tailed surfactants,the maximum adsorption capacities for Nap,Ace and Phe varied as CS-AOT(CS-DDAB):430.0(323.8)611.60(538.18)633.39(536.99)mg/g respectively,outperforming other reported hydrogel beads.The study highlights the simplicity,eco-friendliness,and enhanced performance of surfactant modification for developing high-efficiency adsorbents,paving the way for cost-effective solutions in water re-mediation.展开更多
In this study,chitosan(CS)was combined with microcrystalline cellulose(MCC)to fabricate composite hydrogel beads.These beads were further modified through blending and grafting with polyethyleneimine(PEI)to develop ch...In this study,chitosan(CS)was combined with microcrystalline cellulose(MCC)to fabricate composite hydrogel beads.These beads were further modified through blending and grafting with polyethyleneimine(PEI)to develop chitosan/microcrystalline cellulose@polyethyleneimine(CS/MCC@PEI)composite gel spheres for the efficient adsorption of diclofenac sodium(DS)from aqueous solutions.The adsorbent was characterized using scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier-transform infrared spectroscopy(FTIR),X-ray pho-toelectron spectroscopy(XPS),and thermogravimetric analysis(TGA).The CS/MCC@PEI composite exhibited a spherical morphology with a porous structure,abundant surface functional groups,and a high adsorption capac-ity of 274.84 mg/g for DS.Kinetic studies revealed that the adsorption process followed the pseudo-second-order model,dominated by physical adsorption,with both surface and internal diffusion influencing the adsorption rate.The Freundlich isotherm model best described the adsorption behavior,indicating multilayer adsorption on heterogeneous surfaces.Environmental adaptability tests demonstrated minimal interference from co-existing anions and humic acid,while regeneration experiments confirmed excellent reusability(>77%removal after five cycles).The adsorption mechanism involved electrostatic interactions and hydrogen bonding between the hydroxyl/amino groups of the composite and DS.These findings highlight the potential of CS/MCC@PEI as a cost-effective and sustainable adsorbent for DS removal from water.展开更多
Studies have shown that chitosan protects against neurodegenerative diseases. However, the precise mechanism remains poorly understood. In this study, we administered chitosan intragastrically to an MPTP-induced mouse...Studies have shown that chitosan protects against neurodegenerative diseases. However, the precise mechanism remains poorly understood. In this study, we administered chitosan intragastrically to an MPTP-induced mouse model of Parkinson's disease and found that it effectively reduced dopamine neuron injury, neurotransmitter dopamine release, and motor symptoms. These neuroprotective effects of chitosan were related to bacterial metabolites, specifically shortchain fatty acids, and chitosan administration altered intestinal microbial diversity and decreased short-chain fatty acid production in the gut. Furthermore, chitosan effectively reduced damage to the intestinal barrier and the blood–brain barrier. Finally, we demonstrated that chitosan improved intestinal barrier function and alleviated inflammation in both the peripheral nervous system and the central nervous system by reducing acetate levels. Based on these findings, we suggest a molecular mechanism by which chitosan decreases inflammation through reducing acetate levels and repairing the intestinal and blood–brain barriers, thereby alleviating symptoms of Parkinson's disease.展开更多
A Mg?6%Zn?10%Ca3(PO4)2 composite with a chitosan coating was prepared to study its in vivo biodegradation properties. The chitosan dissolved in a 0.2% acetic acid solution was applied on the surface of Mg?6%Zn?10%Ca3(...A Mg?6%Zn?10%Ca3(PO4)2 composite with a chitosan coating was prepared to study its in vivo biodegradation properties. The chitosan dissolved in a 0.2% acetic acid solution was applied on the surface of Mg?6%Zn?10%Ca3(PO4)2 composite specimens and solidified at 60 °C for 30 min to form the coating. The cytotoxicity evaluation of chitosan coated specimens is at level 0, which indicates that such coating is safe for cellular applications. The in vivotests of chitosan coated composite show that the concentration of metal ions from the composite measured in the venous blood of Zelanian rabbits is less than that from the uncoated composite specimens. The chitosan coating impedes the in vivo degradation of the composite after surgery. The in vivo testing also indicates that the chitosan coated composite is harmless to important visceral organs, including the heart, kidneys and liver of the rabbits. The new bone formation surrounding the chitosan coated composite implant shows that the composite improves the concrescence of the bone tissues. And the chitosan coating is an effective corrosion resistant layer that reduces the hydrogen release of the implant composite, thereby decreasing the subcutaneous gas bubbles formed.展开更多
基金This work was supported by the national key project“973”program of China.(No.G1999054306)“863”program of ministry of education in China(2OOlAA625050)Guangdong Science and technology bureau(No.A302020104).
文摘Because of the incomparable merits （nontoxicity, non-remainder, fast transfer mass） of supercritical carbon dioxide fluid technique（SC-CO2）, it was used to developed a series of novel biodegradable tissue engineering scaffold materials in this research. The novel PLA/chitosan composite materials could be molded to different shapes, and the porosity of the materials were over 200 lam and connected. Chondrocyte cultivation, subcutaneous and intramuscular implantation were mainly discussed this paper. The results showed that the cells could well adhere, grow and multiplicate on the surface of the materials, which indicated good biocompatibility of the composite materials. The plantation test revealed that the PLA materials had already dismissed 2 month late in the body, while the composite materials could still keep certain strength and shape, and the most important things is the response of the tissue toward the implanted PLA/chitosan composite materials was mild and had far less inflammation than PLA materials. 8 to 16 weeks later, fiber membrane was stable; degradation of the materials was seen clear and tissue had already spread into it.
基金MOHE (FRGS/1/2023/STG05/UITM/01/3) for funding support
文摘CRISPR-Cas system permanently deletes any harmful gene-of-interest to combat cancer growth.Chitosan(CS)is a potential cancer therapeutic that mediates via PI3K/Akt/mTOR,MAPK and NF-kβsignaling pathway modulation.CS and its covalent derivatives have been designed as nanocarrier of CRISPR-Cas9 alone(plasmid or ribonucleoprotein)or in combination with chemical drug for cancer treatment.The nanocarrier was functionalized with polyethylene glycol(PEG),targeting ligand,cell penetrating ligand and its inherent positive zeta potential to mitigate premature clearance and particulate aggregation,and promote cancer cell/nucleus targeting and permeabilization to enable CRISPR-Cas9 acting on the host DNA.Different physicochemical attributes are required for the CS-based nanocarrier to survive from the administration site,through the systemic circulation-extracellular matrix-mucus-mucosa axis,to the nucleus target.CRISPR-Cas9 delivery is met with heterogeneous uptake by the cancer cells.Choice of excipients such as targeting ligand and PEG may be inappropriate due to lacking overexpressed cancer receptor or availability of excessive metabolizing enzyme and immunoglobulin that defies the survival and action of these excipients rendering nanocarrier fails to reach the target site.Cancer omics analysis should be implied to select excipients which meet the pathophysiological needs,and chitosan nanocarrier with a“transformative physicochemical behavior”is essential to succeed CRISPR-Cas9 delivery.
基金funded by the joint research collaboration of the Research Organization of Agriculture and Food National Research and Innovation Agency(BRIN)FY 2024(Grant number:6/III.11/HK/2024),with Widya Fatriasari as the Principal Investigator.
文摘Biodegradable plastics are types of plastics that can decompose into water and carbon dioxide the actions of living organisms,mostly by bacteria.Generally,biodegradable plastics are obtained from renewable raw materials,microorganisms,petrochemicals,or a combination of all three.This study aims to develop an innovative bioplastic by combining chitosan and lignin.Bioplastic was prepared by casting method and characterized by measuring the mechanical properties like tensile strength,Young’smodulus,and elongation at break.The chemical structure,together with the interactions among chitosan and lignin and the presence of new chemical bonds,were evaluated by FTIR,while the thermal properties were assessed by thermogravimetric analysis.The water vapor permeability,tests and transparency as well as biodegradability,were also carried out.The results show a tensile strength value of 34.82 MPa,Young’s modulus of 18.54 MPa,and elongation at a break of 2.74%.Moreover,the interaction between chitosan and lignin affects the intensity of the absorption peak,leading to reduced transparency and increased thermal stability.The chitosan/lignin interactions also influence the crystalline size,making it easier to degrade andmore flexible rather than rigid.The contact angle shows the bioplastic’s ability to resist water absorption for 4minutes.In the biodegradation test,the sample began to degrade after 30 days of soil burial test observation.
基金financially supported by National Key Research and Development Program of China (No.2021YFD1800900)National Natural Science Foundation of China (No.82073790)+2 种基金Special Fund for Youth Team of Southwest University (No.SWUXJLJ202306)Chongqing Science and Technology Commission (Nos.CSTB2022TIAD-LUX0001,CSTB2023NSCQ-JQX0002)Innovation Research 2035 Pilot Plan of Southwest University (No.SWUXDPY22007)。
文摘Chitosan(CS),a natural polymer derived from chitin found in the exoskeletons of crustaceans,has garnered significant interest in the pharmaceutical field due to its unique properties,including biocompatibility and biodegradability.In recent years,various studies have reported that CS can affect drug bioavailability,and interestingly,it works as an oral absorption enhancer and inhibitor.This review offers an in-depth analysis of the mechanisms underlying such a phenomenon and supports its application as a pharmaceutical excipient.CS enhances oral drug absorption through various mechanisms,such as interaction with the intestinal mucosa,tight junction modulation,inhibition of efflux transporters,enzyme inhibition,solubility and stability enhancement,and complexation.On the other side,CS exhibits the ability to inhibit the absorption of certain drugs by adsorbing to lipids and sterols,modulating bile acids and gut microbiota,altering drug-cell interaction at the polar interface,and mucus-mediated entrapment and interference.Future potential pharmaceutical research in this field includes elucidating the underneath absorption relevant mechanisms,rational use in formulations as excipient,exploring functional CS derivatives,and developing CS-based drug delivery systems.This comprehensive review highlights CS's versatile and significant role in enhancing and inhibiting oral drug absorption,providing insights into the complexities of drug delivery and the potential of CS to improve therapeutic outcomes.
文摘Proton exchange membrane(PEM)is an integral component in fuel cells which enables proton transport for efficient energy conversion.Sulfonated Polyether Ether Ketone(SPEEK)has emerged as a cost-effective option with non-fluorinated aromatic backbones for Proton Exchange Membrane Fuel Cell(PEMFC)applications,even though it exhibits lower proton conductivity compared to Nafion.This work aims to study the influence of Sulfonated Chitosan(SCS)concentrations on proton conductivity of SPEEK-based PEM at room temperature.SPEEK was synthesized using a sulfonation process with concentrated sulfuric acid at room temperature.SCS was synthesized via reflux of CS and 1.2 M H2SO4 with a ratio of 1:35(w/v)at 90℃ for 30 min.The composite membranes of SPEEK-SCS were formed with four different SCS concentrations,using the solution castingmethod,andDimethyl Sulfoxide(DMSO)was used as a solvent.The composite membranes synthesized include pure SPEEK(S0),SPEEK with 1%SCS(S1),SPEEK with 2%SCS(S2),and SPEEK with 3%SCS(S3).Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),water uptake,degree of swelling,Ionic exchange capacity(IEC)with Electrochemical impedance spectroscopy(EIS)were used to characterize the composite membranes in terms of composition,crystallinity,water absorption,dimensional changes,number of exchangeable ions in membranes,and proton conductivity,respectively.Notably,S3 had the highest water uptake and the lowest degree of swelling.S2 had the highest proton conductivity among the SPEEK-SCS composite membranes at room temperature with 3.44×10^(−2) Scm^(-1).
基金supported by Doctoral Scientific Fund Project of Southwest University of Science and Technology(20zx7130)Seawater Uranium Extraction Innovation and Development Fund Project(China National Nuclear Corporation)(CNNCCXLM-202215)。
文摘Many adsorbents have been developed for uranium recovery to ensure global energy and environmental security.However,most reported adsorbents involve complex preparation process and rely heavily on petrochemical feedstocks,which undoubtedly increases carbon emissions from production in the nuclear industry.Here,a biomass aerogel(CS-BT)is prepared by the facile cross-linking of chitosan and bayberry tannins with glutaraldehyde.U(Ⅵ)can be adsorbed by hydroxyl groups on CS-BT aerogel via chelation,and the maximum adsorption capacity of the obtained aerogel to U(Ⅵ)is 140 mg·g^(-1)and the removal rate reaches up to 99%(at 298.15 K,pH=5.0).The pseudo-second-order kinetics model and Freundlich model can better match the adsorption process of CS-BT aerogel,implying that its adsorption is a chemical adsorption process dominated by multilayer adsorption.The thermodynamic results show that the adsorption process of U(Ⅵ)by CS-BT aerogel is spontaneous and exothermic.Hence,our biomass aerogel can effectively extract uranium from water,contributing to the sustainable development of the nuclear industry.
文摘The cultivation of Soledad pepper(Capsicum annuum L.)is essential in Oaxaca and Veracruz,but it faces issues with pests and diseases,which affect yield and cause economic losses.To mitigate these impacts,farmers have started using biostimulants such as chitosan and plant growth promoting bacteria instead of agrochemicals due to their environmental and health benefits.This study evaluated the effect of Bacillus subtilis and chitosan,both individually and combined,on the growth,yield,and fruit quality of Soledad pepper under greenhouse conditions.Four treatments were applied at different stages of the crop cycle:Q(Chitosan),BS(Bacillus subtilis),Q+BS(Chitosan+Bacillus subtilis),and T(Control).The results showed that the combination of chitosan and Bacillus subtilis significantly improved plant growth,especially in height and stem diameter.The chitosan treatment produced the highest number of fruits and plant weight,while the combination of chitosan and Bacillus subtilis enhanced fruit quality,increasing characteristics such as size,weight,pericarp thickness,and physicochemical parameters,notably in brix degrees,citric acid percentage,and pH,outperforming the individual treatments and the control.
基金supported by research funds of Jeonbuk National University in 2024 and partly supported by the National Research Foundation of Korea(NRF-2019R1A2C1006441)from the Ministry of Education.
文摘Flubendiamide is a commonly used pesticide with low water solubility and a high organic carbon sorption constant,causing it to adhere to soil particles and negatively impact soil ecosystems.First,chili plant stems,typically discarded after the harvest season,represent an abundant local biomass resource with significant potential for utilization,and were converted into biochar through pyrolysis.Here,we describe the synthesis of biochar modified with iron and chitosan to increase the diversity of functions and surface functional groups of biochar.The resulting chitosan-modified magnetic biochar(CMBC)presents a full range of functional groups of chitosan and iron oxide as shown by Fourier-transform infrared spectroscopy.The correlation between flubendiamide concentration and the dose of biochar on adsorption was explored.The flubendiamide adsorption efficiency of CMBC(1%mass ratio of soil)reached 68.03%in 90 min.The highest adsorption capacity achieved was 0.95 mg·g^(−1).The flubendiamide adsorption mechanism by CMBC can be described with a pseudo-second-order kinetic model.The experiment data closely fit a Freundlich isotherm model(R^(2)=0.998),and the low residual sum of squares values demonstrate the high model applicability.In this study,we present a comprehensive overview of pesticides,alongside kinetic and isotherm model studies of flubendiamide adsorption by CMBC.We emphasize the potential of modified biochar to enhance environmental remediation applications.
文摘Melt blending of biodegradable polyesters such as poly(lactic acid)(PLA)and poly(butylene adipate co-terephthalate)(PBAT)with a compatibilizer and natural filler offers a chance to develop biodegradable biocomposites with improved performance.In this study,we examined how PLA/PBAT blends behave during ultimate biodegradation(mineralization),both with and without compatibilizer and algae as a reinforcement,under controlled composting conditions using carbon dioxide(CO_(2))respirometry techniques.Throughout the biodegradation process,the disintegration behaviour,thermal,chemical,and morphological properties of test samples before and after biodegradation were analyzed using FTIR,TGA,DSC,and SEM techniques.The results from CO_(2)biodegradation showed that PLA/PBAT blend exhibits a higher rate of biodegradation compared to neat PLA and PBAT.The addition of algae to a compatibilized PLA/PBAT blend showed an enhanced biodegradation rate due to hydrolytic cleavage and microbial assimilation.This was further supported by the disintegration test,where algae-reinforced composites showed fragmentation within 30 days.FTIR,TGA and SEM analysis revealed the structural changes that occurred during biodegradation,highlighting the role of algae in affecting the thermal stability and surface morphology.After the compost biodegradation step,eco-toxicity seed germination was conducted on the test samples.Plant seed germination test results confirmed that all test samples achieved maximumgermination.This indicates there were no toxic residues,suggesting that the degraded materials are environmentally safe.Overall,this study contributes to the understanding of biodegradation mechanisms and the ecological impact of bio-based polymer composites as eco-friendly materials and products.
基金the Department of Science and Technology(DST),Govt.of India for providing funds under the FIST program and PURSE grant vide No.SR/PURSE/2020/31 to the department of Chemistry,University of Kashmir.
文摘This study presents a thorough investigation into the use of single and twin-tailed cationic and anionic surfactant-modified chitosan(SMCS)hydrogel beads as effective adsorbents for the elimination of hazardous polycyclic aromatic hydrocarbons(PAHs)from aqueous solutions.The Chitosan(CS)hydrogel beads were modified with single/twin-tailed anionic surfactants,sodium dodecyl sulfate(SDS)and sodium bis(2-ethylhexyl)sulfosuccinate(AOT),and cationic surfactants,dodecyltrimethylammonium bromide(DTAB)and didodecyldimethylammonium bromide(DDAB),to enhance their adsorption capacity of PAHs.The CS and SMCS beads were evaluated for their structural,mechanical,and adsorption properties using a range of techniques,including infrared spectroscopy(IR),energy-dispersive X-ray spectroscopy(EDX),rheometry,and field emission scanning electron microscopy(FESEM).Adsorption experiments of naphthalene(Nap),acenaphthene(Ace),and phenanthrene(Phe)on SMCS beads demonstrate that they have significantly higher adsorption capacities than CS beads,due to increase in hydrophobic interactions.Adsorption capacity followed the trend,Phen>Ace>Nap for all the beads revealing that twin-tailed SMCS bead possess much higher adsorption capacities(Qmax)compared to single-tailed SMCS beads.For twin tailed surfactants,the maximum adsorption capacities for Nap,Ace and Phe varied as CS-AOT(CS-DDAB):430.0(323.8)611.60(538.18)633.39(536.99)mg/g respectively,outperforming other reported hydrogel beads.The study highlights the simplicity,eco-friendliness,and enhanced performance of surfactant modification for developing high-efficiency adsorbents,paving the way for cost-effective solutions in water re-mediation.
基金supported by the Open Project Funding of Key Laboratory of Intelligent Health Perception and Ecological Restoration of Rivers and Lakes,Ministry of Education,Hubei University of Technology(No.HGKFZ03).
文摘In this study,chitosan(CS)was combined with microcrystalline cellulose(MCC)to fabricate composite hydrogel beads.These beads were further modified through blending and grafting with polyethyleneimine(PEI)to develop chitosan/microcrystalline cellulose@polyethyleneimine(CS/MCC@PEI)composite gel spheres for the efficient adsorption of diclofenac sodium(DS)from aqueous solutions.The adsorbent was characterized using scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier-transform infrared spectroscopy(FTIR),X-ray pho-toelectron spectroscopy(XPS),and thermogravimetric analysis(TGA).The CS/MCC@PEI composite exhibited a spherical morphology with a porous structure,abundant surface functional groups,and a high adsorption capac-ity of 274.84 mg/g for DS.Kinetic studies revealed that the adsorption process followed the pseudo-second-order model,dominated by physical adsorption,with both surface and internal diffusion influencing the adsorption rate.The Freundlich isotherm model best described the adsorption behavior,indicating multilayer adsorption on heterogeneous surfaces.Environmental adaptability tests demonstrated minimal interference from co-existing anions and humic acid,while regeneration experiments confirmed excellent reusability(>77%removal after five cycles).The adsorption mechanism involved electrostatic interactions and hydrogen bonding between the hydroxyl/amino groups of the composite and DS.These findings highlight the potential of CS/MCC@PEI as a cost-effective and sustainable adsorbent for DS removal from water.
基金supported by the National Natural Science Foundation of China,Nos. 32260196 (to JY), 81860646 (to ZY) and 31860274 (to JY)a grant from Yunnan Department of Science and Technology,Nos. 202101AT070251 (to JY), 202201AS070084 (to ZY), 202301AY070001-239 (to JY), 202101AZ070001-012, and 2019FI016 (to ZY)。
文摘Studies have shown that chitosan protects against neurodegenerative diseases. However, the precise mechanism remains poorly understood. In this study, we administered chitosan intragastrically to an MPTP-induced mouse model of Parkinson's disease and found that it effectively reduced dopamine neuron injury, neurotransmitter dopamine release, and motor symptoms. These neuroprotective effects of chitosan were related to bacterial metabolites, specifically shortchain fatty acids, and chitosan administration altered intestinal microbial diversity and decreased short-chain fatty acid production in the gut. Furthermore, chitosan effectively reduced damage to the intestinal barrier and the blood–brain barrier. Finally, we demonstrated that chitosan improved intestinal barrier function and alleviated inflammation in both the peripheral nervous system and the central nervous system by reducing acetate levels. Based on these findings, we suggest a molecular mechanism by which chitosan decreases inflammation through reducing acetate levels and repairing the intestinal and blood–brain barriers, thereby alleviating symptoms of Parkinson's disease.
基金Project(2014)supported by the Open Fund of the State Key Laboratory of Powder Metallurgy,China
文摘A Mg?6%Zn?10%Ca3(PO4)2 composite with a chitosan coating was prepared to study its in vivo biodegradation properties. The chitosan dissolved in a 0.2% acetic acid solution was applied on the surface of Mg?6%Zn?10%Ca3(PO4)2 composite specimens and solidified at 60 °C for 30 min to form the coating. The cytotoxicity evaluation of chitosan coated specimens is at level 0, which indicates that such coating is safe for cellular applications. The in vivotests of chitosan coated composite show that the concentration of metal ions from the composite measured in the venous blood of Zelanian rabbits is less than that from the uncoated composite specimens. The chitosan coating impedes the in vivo degradation of the composite after surgery. The in vivo testing also indicates that the chitosan coated composite is harmless to important visceral organs, including the heart, kidneys and liver of the rabbits. The new bone formation surrounding the chitosan coated composite implant shows that the composite improves the concrescence of the bone tissues. And the chitosan coating is an effective corrosion resistant layer that reduces the hydrogen release of the implant composite, thereby decreasing the subcutaneous gas bubbles formed.
