The aim of this case report was to demonstrate the effectivity of chitosan as topical agent on the treatment of severely infected canine extremity wound. The dog was hit by a bus and presented severe friction wounds a...The aim of this case report was to demonstrate the effectivity of chitosan as topical agent on the treatment of severely infected canine extremity wound. The dog was hit by a bus and presented severe friction wounds accompanying with bilateral hip and extremity fractures. Local and generalized infections were observed on the post operational period. The dog was unresponsive to the standard therapeutic protocols and health status was getting worsened. The regenerative sutures did not hold the tissues because of the infection and the tissue eruption. Chitosan samples were extracted from shrimp shell wastes. The milled form of chitosan was topically used to treat the open and heavily mix infected wound areas located at skin and rear extremities accompanying with fever and Canine coronavirus diarrhea. It was decided to use the chitosan as a bio barrier and anti-bio affect over the damaged and erupted tissues. Macroscopic fmdings indicated chitosan promoted the natural blood clotting and absorbed the inflammation fluid. Microscopic findings indicated the infiltration of polymorph nuclear leukocytes （PMN） accelerated with the topical use of chitosan in the early phase of wound healing. The wound healing was observed daily. This veterinary practice wound treatment result indicated that chitosan is effective to medicate topically the canine open and mix infected wounds with bacteria and viruses and promotes the granulomatosis in four weeks period.展开更多
Chitosan is one of the most studied polysaccharides nowadays. Because it is non-toxic, widely used in food, pharmaceutical processes, agricultural, and presents excellent biological properties such as biodegradation i...Chitosan is one of the most studied polysaccharides nowadays. Because it is non-toxic, widely used in food, pharmaceutical processes, agricultural, and presents excellent biological properties such as biodegradation in the human body, and antibacterial. In the present study we reported the extraction of low cost chitosans (Cs1, Cs2, Cs3 and Cs4) from shrimp shells by extraction of chitin (Egypt: case study), then alkaline deacetylation of chitin with strong alkaline solution at different period of time. The different prepared chitosans (Cs1, Cs2, Cs3 and Cs4) were characterized by FTIR spectroscopy, thermal stability, morphology, crystallography, elemental analysis and degree of deacetylation. The data showed that the prepared chitosan Cs2 has the most thermal stability and the highest degree of deacetylation.展开更多
Recently,Cu-based single-atom catalysts(SACs)have garnered increasing attention as substitutes for platinum-based catalysts in the oxygen reduction reaction(ORR).Therefore,a facile,economical,and efficient synthetic m...Recently,Cu-based single-atom catalysts(SACs)have garnered increasing attention as substitutes for platinum-based catalysts in the oxygen reduction reaction(ORR).Therefore,a facile,economical,and efficient synthetic methodology for the preparation of a high-performance Cu-based SAC electrocatalyst for the ORR is extremely desired,but is also significantly challenging.In this study,we propose a ball-milling method to synthesize isolated metal SACs embedded in S,N-codoped nanocarbon(MNSDC,M=Cu,Fe,Co,Ni,Mn,Pt,and Pd).In particular,the Cu-NSDC SACs exhibit high electrochemical activity for the ORR with half-wave potential(E_(1/2))of 0.84 V(vs.reversible hydrogen electrode(RHE),20 mV higher than Pt/C)in alkaline electrolyte,excellent stability,and electrocatalytic selectivity.Density functional theory(DFT)calculations demonstrated that the desorption of OH*intermediates was the rate-determining step over Cu-NSDC.This study creates a pathway for high-performance ORR single atomic electrocatalysts for fuel cell applications and provides opportunities to convert biowaste materials into commercial opportunities.展开更多
Chitin is the second most abundant polysaccharide,produced mainly as an industrial waste stream during crustacean processing.Chitin can be derived into chitosan through the deacetylation process.Conversion of shrimp w...Chitin is the second most abundant polysaccharide,produced mainly as an industrial waste stream during crustacean processing.Chitin can be derived into chitosan through the deacetylation process.Conversion of shrimp waste into chitosan via the deacetylation process could be considered a practical approach for shell waste remediation.In this study,chitosan’s physicochemical characteristics extracted from two types of Pacific white leg shrimp,L.vannamei’s shell(i.e.,rough and smooth),were compared with commercial chitosan.The yield,moisture,ash,solubility,water and fat binding capacity were measured.The degree of deacetylation(DDA)was calculated using FTIR,and their chemical Structure was confirmed using XRD and SEM-EDS.Both extracted chitosan showed no significant difference in yield,moisture,ash,solubility and water binding capacity but showed a significant difference with commercial chitosan.Moreover,the fat binding capacity of commercial chitosan showed the lowest percentage(408.34±0.83%)as compared to extracted chitosan(smooth shell 549.59±12.48%;rough shell 500.55±12.10%).The DDA indicated that extracted chitosan from the smooth and rough shell was considered good chitosan as compared to commercial chitosan with 84.08±1.27%,80.78±0.79%and 74.99±1.48%,respectively.Additionally,the presence of hydroxyl and amino groups from FTIR and a good crystallinity index was recorded using XRD of extracted chitosan.Based on observed characteristics,shrimp shell waste from L.vannamei can achieve chitosan standard quality as a biopolymer and highly potential to be applied in various industrial applications.展开更多
The use of chitin as raw material to obtain glucosamine hydrochloride at laboratory level was investigated. Chitin was extracted from shrimp shells by deproteinization, demineralization and depigmentation. Afterwards,...The use of chitin as raw material to obtain glucosamine hydrochloride at laboratory level was investigated. Chitin was extracted from shrimp shells by deproteinization, demineralization and depigmentation. Afterwards, glucosamine hydrochloride was produced in four main stages： （1） acid hydrolysis of chitin with 12 M hydrochloric acid using the reflux technique; （2） filtration of the solution to discard solid impurities; （3） recrystallization of the product using 95% ethyl alcohol as solvent, and （4） filtration, washing and drying of final product at 50 ℃. The FTIR spectrum of the product was compared to a commercial glucosamine hydrochloride of 99.86% purity, and a coincidence between 96.90% and 99.66% was obtained. The influence of temperature, solid/liquid ratio （g/mL）, and agitation （with-without） on acid hydrolysis was studied. The best correlation corresponds to the hydrolysis product obtained at solid/liquid ratio of 1：20, temperature of 85 ℃, and with agitation. The yields of glucosamine hydrochloride with respect to chitin were 42, 58, 36 and 48% for solid/liquid ratios of 1：10, 1：20, 1：30, and 1：40 respectively, at high hydrolysis reaction temperature and with agitation. These results showed that in the range examined, glucosamine hydrochloride with high quality is produced with solid/liquid ratio of 1：20.展开更多
文摘The aim of this case report was to demonstrate the effectivity of chitosan as topical agent on the treatment of severely infected canine extremity wound. The dog was hit by a bus and presented severe friction wounds accompanying with bilateral hip and extremity fractures. Local and generalized infections were observed on the post operational period. The dog was unresponsive to the standard therapeutic protocols and health status was getting worsened. The regenerative sutures did not hold the tissues because of the infection and the tissue eruption. Chitosan samples were extracted from shrimp shell wastes. The milled form of chitosan was topically used to treat the open and heavily mix infected wound areas located at skin and rear extremities accompanying with fever and Canine coronavirus diarrhea. It was decided to use the chitosan as a bio barrier and anti-bio affect over the damaged and erupted tissues. Macroscopic fmdings indicated chitosan promoted the natural blood clotting and absorbed the inflammation fluid. Microscopic findings indicated the infiltration of polymorph nuclear leukocytes （PMN） accelerated with the topical use of chitosan in the early phase of wound healing. The wound healing was observed daily. This veterinary practice wound treatment result indicated that chitosan is effective to medicate topically the canine open and mix infected wounds with bacteria and viruses and promotes the granulomatosis in four weeks period.
文摘Chitosan is one of the most studied polysaccharides nowadays. Because it is non-toxic, widely used in food, pharmaceutical processes, agricultural, and presents excellent biological properties such as biodegradation in the human body, and antibacterial. In the present study we reported the extraction of low cost chitosans (Cs1, Cs2, Cs3 and Cs4) from shrimp shells by extraction of chitin (Egypt: case study), then alkaline deacetylation of chitin with strong alkaline solution at different period of time. The different prepared chitosans (Cs1, Cs2, Cs3 and Cs4) were characterized by FTIR spectroscopy, thermal stability, morphology, crystallography, elemental analysis and degree of deacetylation. The data showed that the prepared chitosan Cs2 has the most thermal stability and the highest degree of deacetylation.
基金supported by the National Key Research and Development Program Nanotechnology Specific Project(No.2020YFA0210900)the National Natural Science Foundation of China(Nos.21908255,22078371,22108315,21938001,and 21961160741)+3 种基金the Guangdong Provincial Key R&D Programme(No.2019B110206002)the Science and Technology Key Project of Guangdong Province(No.2020B010188002)the Guangdong Basic and Applied Basic Research Foundation(No.2020A1515110864)the Guangdong Natural Science Foundation(No.2021A1515010163).
文摘Recently,Cu-based single-atom catalysts(SACs)have garnered increasing attention as substitutes for platinum-based catalysts in the oxygen reduction reaction(ORR).Therefore,a facile,economical,and efficient synthetic methodology for the preparation of a high-performance Cu-based SAC electrocatalyst for the ORR is extremely desired,but is also significantly challenging.In this study,we propose a ball-milling method to synthesize isolated metal SACs embedded in S,N-codoped nanocarbon(MNSDC,M=Cu,Fe,Co,Ni,Mn,Pt,and Pd).In particular,the Cu-NSDC SACs exhibit high electrochemical activity for the ORR with half-wave potential(E_(1/2))of 0.84 V(vs.reversible hydrogen electrode(RHE),20 mV higher than Pt/C)in alkaline electrolyte,excellent stability,and electrocatalytic selectivity.Density functional theory(DFT)calculations demonstrated that the desorption of OH*intermediates was the rate-determining step over Cu-NSDC.This study creates a pathway for high-performance ORR single atomic electrocatalysts for fuel cell applications and provides opportunities to convert biowaste materials into commercial opportunities.
基金funded by The Ministry of Higher Education(MOHE)Malaysia,under The Higher Institution Centre of Excellence(HICoE)Institute of Tropical Aquaculture and Fisheries(AKUATROP)Program[Vot.No.63933,JPT.S(BPKI)2000/016/018/015 Jld.3(23)and Vot.No.56050,UMT/PPPI/2-2/5 Jld.2(24)].This work was also funded by the Long-Term Research Grant Scheme 1/2018,LRGS(LRGS/2018/USM-UKM/EWS/01).
文摘Chitin is the second most abundant polysaccharide,produced mainly as an industrial waste stream during crustacean processing.Chitin can be derived into chitosan through the deacetylation process.Conversion of shrimp waste into chitosan via the deacetylation process could be considered a practical approach for shell waste remediation.In this study,chitosan’s physicochemical characteristics extracted from two types of Pacific white leg shrimp,L.vannamei’s shell(i.e.,rough and smooth),were compared with commercial chitosan.The yield,moisture,ash,solubility,water and fat binding capacity were measured.The degree of deacetylation(DDA)was calculated using FTIR,and their chemical Structure was confirmed using XRD and SEM-EDS.Both extracted chitosan showed no significant difference in yield,moisture,ash,solubility and water binding capacity but showed a significant difference with commercial chitosan.Moreover,the fat binding capacity of commercial chitosan showed the lowest percentage(408.34±0.83%)as compared to extracted chitosan(smooth shell 549.59±12.48%;rough shell 500.55±12.10%).The DDA indicated that extracted chitosan from the smooth and rough shell was considered good chitosan as compared to commercial chitosan with 84.08±1.27%,80.78±0.79%and 74.99±1.48%,respectively.Additionally,the presence of hydroxyl and amino groups from FTIR and a good crystallinity index was recorded using XRD of extracted chitosan.Based on observed characteristics,shrimp shell waste from L.vannamei can achieve chitosan standard quality as a biopolymer and highly potential to be applied in various industrial applications.
文摘The use of chitin as raw material to obtain glucosamine hydrochloride at laboratory level was investigated. Chitin was extracted from shrimp shells by deproteinization, demineralization and depigmentation. Afterwards, glucosamine hydrochloride was produced in four main stages： （1） acid hydrolysis of chitin with 12 M hydrochloric acid using the reflux technique; （2） filtration of the solution to discard solid impurities; （3） recrystallization of the product using 95% ethyl alcohol as solvent, and （4） filtration, washing and drying of final product at 50 ℃. The FTIR spectrum of the product was compared to a commercial glucosamine hydrochloride of 99.86% purity, and a coincidence between 96.90% and 99.66% was obtained. The influence of temperature, solid/liquid ratio （g/mL）, and agitation （with-without） on acid hydrolysis was studied. The best correlation corresponds to the hydrolysis product obtained at solid/liquid ratio of 1：20, temperature of 85 ℃, and with agitation. The yields of glucosamine hydrochloride with respect to chitin were 42, 58, 36 and 48% for solid/liquid ratios of 1：10, 1：20, 1：30, and 1：40 respectively, at high hydrolysis reaction temperature and with agitation. These results showed that in the range examined, glucosamine hydrochloride with high quality is produced with solid/liquid ratio of 1：20.
