Florfenicol(FLO)is a chemically synthesized broad-spectrum antimicrobial agent of amide alcohols for animals,which is one of the most widely used antimicrobials in livestock,poultry,and aquaculture.With the use of FLo...Florfenicol(FLO)is a chemically synthesized broad-spectrum antimicrobial agent of amide alcohols for animals,which is one of the most widely used antimicrobials in livestock,poultry,and aquaculture.With the use of FLo,more and more attention has been paid to its hematopoietic toxicity,immunotoxicity,genotoxicity,and embryotoxicity.In this study,SPF chicks.at the age of 3 d began to drink water with the FLO at a dose of 100 mg L^(-1)for 6 consecutive days,and the growth performance of chicks was monitored,the effect of FLO on immune organs was detected by pathological examination and TdT-mediated dUTP nick-end labeling(TUNEL)apoptosis staining.In order to evaluate the level of organism immunity,the level of Newcastle disease virus antibody in serum was detected by hemagglutination inhibition test,the content of cytokines(IL-1,IL-2,IL-6,TNF-α,IFN-γ)in serum was detected by enzyme linked immunosorbent assay(ELISA),and the transcription of interferon-related genes(IRF-7,2′-5′OAS,Mx1)and cytokine genes(IL-6,TNF-α,IFN-γ)in immune organs were detected by real time fluorescence quantitative PCR.The results showed that the early application of FLO could inhibit the growth and development of chicks,and the body weight and immune organ index of the treatment group were lower than those of the control group.Histopathological examination showed that there was a decrease in the number of lymphocytes in the bursa of Fabricius in the treatment group in the early stage of drug withdrawal,and the results of TUNEL apoptosis staining in the bursa of Fabricius showed that obvious lymphocyte apoptosis occurred in the FLO treatment group.Compared with the control group,the transcription levels of interferon-related genes IRF-7,2′-5′OAS,and cytokine genes IL-6,TNF-αand IFN-γin FLO treatment group decreased to a certain extent,while the transcription level of Mx1 gene had no significant difference at all time points.The level of serum Newcastle disease virus(NDV)antibody and the contents of cytokines IL-1,IL-2 and IFN-γin the FLO treatment group were significantly lower than those in the control group in the early stage of drug withdrawal,but recovered gradually in the later stage.This study showed that FLO has a certain degree of effect on the immune function of chicks,and the results of the study laid the foundation for further research on the mechanism of FLO-induced immunotoxicity.展开更多
Here,we report the production of 3D-printed MoS_(2)/Ni electrodes(3D-MoS_(2)/Ni)with longterm stability and excellent performance by the selective laser melting(SLM)technique.As a cathode,the obtained 3D-MoS_(2)/Ni co...Here,we report the production of 3D-printed MoS_(2)/Ni electrodes(3D-MoS_(2)/Ni)with longterm stability and excellent performance by the selective laser melting(SLM)technique.As a cathode,the obtained 3D-MoS_(2)/Ni could maintain a degradation rate above 94.0%for forfenicol(FLO)when repeatedly used 50 times in water.We also found that the removal rate of FLO by 3D-MoS_(2)/Ni was about 12 times higher than that of 3D-printed pure Ni(3D-Ni),attributed to the improved accessibility of H^(*).In addition,the electrochemical characterization results showed that the electrochemically active surface area of the 3D-MoS_(2)/Ni electrode is about 3-fold higher than that of the 3D-Ni electrode while the electrical resistance is 4 times lower.Based on tert-butanol suppression,electron paramagnetic resonance and triple quadrupole mass spectrometer experiments,a“dual path”mechanism and possible degradation pathway for the dechlorination of FLO by 3D-MoS_(2)/Ni were proposed.Furthermore,we also investigated the impacts of the cathode potential and the initial pH of the solution on the degradation of FLO.Overall,this study reveals that the SLM 3D printing technique is a promising approach for the rapid fabrication of high-stability metal electrodes,which could have broad application in the control of water contaminants in the environmental field.展开更多
Herein,the degradation of florfenicol(FLO)over zero-valent iron(ZVI)enhanced by SiC was systematically investigated.It was found that 5 g/L of ZVI/SiC(1:3)at pH 3.0 could completely degrade 20 mg/L of FLO within 1 h,w...Herein,the degradation of florfenicol(FLO)over zero-valent iron(ZVI)enhanced by SiC was systematically investigated.It was found that 5 g/L of ZVI/SiC(1:3)at pH 3.0 could completely degrade 20 mg/L of FLO within 1 h,with a Kobsvalue of 0.0873 min^(-1),12.5 times greater than that of pure ZVI(0.0069 min^(-1)).Vibrating sample magnetometer(VSM)characterizations revealed that the use of SiC supporter reduces the magnetic intensity of ZVI,which mitigates iron particle agglomeration,increases Brunauer-Emmett-Teller(BET)surface area,and enhances FLO degradation efficiency.Furthermore,ZVI/SiC exhibits a much lower hydrogen evolution potential(HEP)and significantly higher corrosion currents compared to pure ZVI.FLO was proposed to undergo degradation via reductive dechlorination,involving a hydrogenolysis mechanism that entails the cleavage of theσbond.This study provides new insights into the reduction hydrogenation mechanism of ZVI.展开更多
Antibiotics are widespread in various environmental media,and may pose a potential threat to aquatic ecosystems and non-target aquatic organisms.Florfenicol(FLO)is one of the most commonly used antibiotics in aquacult...Antibiotics are widespread in various environmental media,and may pose a potential threat to aquatic ecosystems and non-target aquatic organisms.Florfenicol(FLO)is one of the most commonly used antibiotics in aquaculture,and extensively used to substitute chloramphenicol with its strong sterilization and low adverse ef fect.In this study,flounder Paralichthys olivaceus,an important economic fish species in seawater was used as an experimental subject.Five exposure concentrations of FLO(including environmentrelated concentrations)were set at 0,0.01,0.1,1,and 10 mg/L.Ef fects of FLO exposure for 168 h on growth and development,motor behavior,antioxidant enzyme activity,malondialdehyde(MDA)content,and thyroid hormone level of P.olivaceus larvae were studied in pre-larvae(1 dpf)and post-larvae(20 dpf).The results show that the short-term FLO exposure could promote the larvae growth to some degrees,but inhibit them as the exposure time prolonged.For pre-larvae,FLO at 0.01 mg/L could stimulate the motor nerve system and increase the swimming ability,but inhibited it at 1 mg/L.With the increasing dosage of FLO,the superoxide dismutase(SOD)and MDA contents were elevated,reaching the maximum in the 1 mg/L FLO group.The pre-larvae were more sensitive than the post-larvae to FLO in the environment,and the growth and immune resistance could be damaged with long exposure.Post-larvae were more tolerant to external pollutants,FLO at 1 mg/L could promote the motor behavior and reduce SOD and MDA contents.Therefore,FLO can be used as an antibiotic at a proper concentration but as a drug to prevent disease in a long-term way.展开更多
Eggshell-loaded CoFe_(2)O_(4) catalyst was synthesized via a convenient hydrothermal method during our work,then the surface morphology and elemental composition of the composites were systematically investigated.Perf...Eggshell-loaded CoFe_(2)O_(4) catalyst was synthesized via a convenient hydrothermal method during our work,then the surface morphology and elemental composition of the composites were systematically investigated.Performance of CoFe_(2)O_(4)/eggshell-activated peroxymonosulfate(PMS)system was evaluated by selecting florfenicol(FF)as the model pollutant,and effects of operating parameters and water matrices on the FF removal efficiency in this system were investigated.In addition,main radicals involved in FF degradation were identified by EPR tests and radical quenching experiments,and possible mechanism was proposed.The reduction of toxicity during FF degradation was confirmed,and in combination with HP-LC tests,it was found that dehalogenation and defluorination were effectively carried out during FF degradation.In addition,the prepared CoFe_(2)O_(4)polyvinylidene fluoride(PVDF)membrane effectively improved the stability of the material and reduced the precipitation of metals.展开更多
[Objective] The paper was to study in vitro pharmacodynamics characteristics of florfenicol dual suspension emulsion (DSEF). [Method] The florfenicol injection (FI) was used as the control group, the minimal inhibitor...[Objective] The paper was to study in vitro pharmacodynamics characteristics of florfenicol dual suspension emulsion (DSEF). [Method] The florfenicol injection (FI) was used as the control group, the minimal inhibitory concentration (MIC), minimal bactericide concentration (MBC) and mutant selection window (MSW) of florfenicol dual suspension emulsion on 5 kinds of bacteria were determined. The post-antibiotic effect (PAE) and post-antibiotic sub-MIC effect (PASME) of Salmonella typhimurium were also measured. [Result] Compared with the ordinary injection, the MIC and MBC of florfenicol dual suspension emulsion on 5 kinds of bacteria showed no obvious changes. However, florfenicol dual suspension emulsion obviously narrowed MSW of 5 kinds of bacteria (P<0.01), which also significantly extended PAE and PASME of S. typhimurium (P<0.01). [Conclusion] The florfenicol dual suspension emulsion in vitro can reduce the probability of bacterial resistance, significantly prolong after effect time of antibiotics on bacteria, thereby effectively improving the antibacterial effect.展开更多
Doxycycline hydrochloride and florfenicol combination(DoxHcl&FF)is an effective treatment for respiratory diseases.In the study,our objective Was to evaluate the activity of DoxHcl&FF against Actinobacillus pl...Doxycycline hydrochloride and florfenicol combination(DoxHcl&FF)is an effective treatment for respiratory diseases.In the study,our objective Was to evaluate the activity of DoxHcl&FF against Actinobacillus pleuropneumoniae(APP)in porcine pulmonary epithelial lining fluid(PELF)and the optimal dosage scheme to avoid the development of resistance.The DoxHcl&FF Was administered intramuscularly(IM)at 20mg/kg,and the PELF was collected at differ-ent time points.The minimum inhibitory concentration(MIC)and time-mortality curves were also included in the study.Based on the sigmoid Emax equation and dose equations,the study integrated the in vivo pharmacokinetic data of infected pigs and ex vivo pharmacodynamic data to obtain the area under concentration time curve(AUCo-24h)MIC values in PELF and achieve bacteriostatic activity,bactericidal activity and the virtual eradication of bacteria.The study showed that the combination of DoxHcl and FF caused no significant changes in PK parameters.The peak concentration(Cmax)of FF in healthy and diseased pigs was 8.87±0.08 and 8.67±0.07μg/mL,the_AUCo-24h were.172.75±2.52 and 18022±3.13 h-μg/mL,the Cmax of DoxHcl was 7.91±0.09 and 7.99±0.05μg/mL,and the AUCo-24h was 129.96±3.70 h-μg/mL and 169.82±4.38 h-μg/mL.DoxHcl&FF showed strong concentra-tion-dependent tendencies.The bacteriostatic,bactericidal,and elimination activity were calculated as 5.61,18.83 and 32.68 h,and the doses were 1.37(bacteriostatic),4.59(bactericidal)and 7.99(elimination)mg/kg.These findings indicated that the calculated recommended dose could assist in achieving more precise administration,increasing the effectiveness of DoxHcl&FF treatment for APP infections.展开更多
Thiamphenicol(THA) and florfenicol(FLO) aqueous solutions were irradiated to different doses by 1 MeV electron beams,and redox reactions of THA/FLO and radicals of OH,e_(eq)^- and ~·H were investigated under vari...Thiamphenicol(THA) and florfenicol(FLO) aqueous solutions were irradiated to different doses by 1 MeV electron beams,and redox reactions of THA/FLO and radicals of OH,e_(eq)^- and ~·H were investigated under various conditions.The results showed that at 8 kGy,the decomposition rate of THA and FLO was 97.2%and 98.5%, respectively.Quantitative and qualitative analysis indicated that OH played a key role in E-beam degradation of the THA and FLO in aqueous solutions,and e_(eq)^- and ~·H radicals could initiate the degradation,too.Seven primary products of the THA and FLO degradation were identified.These indicate that E-beam radiation is an effective method to reduce THA and FLO in aqueous solutions.展开更多
文摘Florfenicol(FLO)is a chemically synthesized broad-spectrum antimicrobial agent of amide alcohols for animals,which is one of the most widely used antimicrobials in livestock,poultry,and aquaculture.With the use of FLo,more and more attention has been paid to its hematopoietic toxicity,immunotoxicity,genotoxicity,and embryotoxicity.In this study,SPF chicks.at the age of 3 d began to drink water with the FLO at a dose of 100 mg L^(-1)for 6 consecutive days,and the growth performance of chicks was monitored,the effect of FLO on immune organs was detected by pathological examination and TdT-mediated dUTP nick-end labeling(TUNEL)apoptosis staining.In order to evaluate the level of organism immunity,the level of Newcastle disease virus antibody in serum was detected by hemagglutination inhibition test,the content of cytokines(IL-1,IL-2,IL-6,TNF-α,IFN-γ)in serum was detected by enzyme linked immunosorbent assay(ELISA),and the transcription of interferon-related genes(IRF-7,2′-5′OAS,Mx1)and cytokine genes(IL-6,TNF-α,IFN-γ)in immune organs were detected by real time fluorescence quantitative PCR.The results showed that the early application of FLO could inhibit the growth and development of chicks,and the body weight and immune organ index of the treatment group were lower than those of the control group.Histopathological examination showed that there was a decrease in the number of lymphocytes in the bursa of Fabricius in the treatment group in the early stage of drug withdrawal,and the results of TUNEL apoptosis staining in the bursa of Fabricius showed that obvious lymphocyte apoptosis occurred in the FLO treatment group.Compared with the control group,the transcription levels of interferon-related genes IRF-7,2′-5′OAS,and cytokine genes IL-6,TNF-αand IFN-γin FLO treatment group decreased to a certain extent,while the transcription level of Mx1 gene had no significant difference at all time points.The level of serum Newcastle disease virus(NDV)antibody and the contents of cytokines IL-1,IL-2 and IFN-γin the FLO treatment group were significantly lower than those in the control group in the early stage of drug withdrawal,but recovered gradually in the later stage.This study showed that FLO has a certain degree of effect on the immune function of chicks,and the results of the study laid the foundation for further research on the mechanism of FLO-induced immunotoxicity.
基金supported by the Guangdong Province Youth Innovative Talents Project in Higher Education (No.2018KQNCX257)the Guangdong Province Enterprise Science and Technology Commissioner Project (No.GDKTP2021048000)+4 种基金the Key-Area Research and Development Program of Guangdong Province (No.2020B090923002)the Guangdong-Dongguan Joint Fund (No.2019B151530005)the Guangdong Basic and Applied Basic Research Foundation (No.2019A1515110497)the National Natural Science Foundation of China (No.41907292)the National Natural Science Foundation of China (No.21876130)。
文摘Here,we report the production of 3D-printed MoS_(2)/Ni electrodes(3D-MoS_(2)/Ni)with longterm stability and excellent performance by the selective laser melting(SLM)technique.As a cathode,the obtained 3D-MoS_(2)/Ni could maintain a degradation rate above 94.0%for forfenicol(FLO)when repeatedly used 50 times in water.We also found that the removal rate of FLO by 3D-MoS_(2)/Ni was about 12 times higher than that of 3D-printed pure Ni(3D-Ni),attributed to the improved accessibility of H^(*).In addition,the electrochemical characterization results showed that the electrochemically active surface area of the 3D-MoS_(2)/Ni electrode is about 3-fold higher than that of the 3D-Ni electrode while the electrical resistance is 4 times lower.Based on tert-butanol suppression,electron paramagnetic resonance and triple quadrupole mass spectrometer experiments,a“dual path”mechanism and possible degradation pathway for the dechlorination of FLO by 3D-MoS_(2)/Ni were proposed.Furthermore,we also investigated the impacts of the cathode potential and the initial pH of the solution on the degradation of FLO.Overall,this study reveals that the SLM 3D printing technique is a promising approach for the rapid fabrication of high-stability metal electrodes,which could have broad application in the control of water contaminants in the environmental field.
基金financially supported by the Guangdong Basic and Applied Basic Research Foundation(No.2021A1515110954)National Key Research and Development Projects of China(No.2022YEC3203302)+1 种基金Guangdong Province Enterprise Science and Technology Commissioner Project(No.GDKTP2021048000)National Natural Science Foundation of China(No.41907292)。
文摘Herein,the degradation of florfenicol(FLO)over zero-valent iron(ZVI)enhanced by SiC was systematically investigated.It was found that 5 g/L of ZVI/SiC(1:3)at pH 3.0 could completely degrade 20 mg/L of FLO within 1 h,with a Kobsvalue of 0.0873 min^(-1),12.5 times greater than that of pure ZVI(0.0069 min^(-1)).Vibrating sample magnetometer(VSM)characterizations revealed that the use of SiC supporter reduces the magnetic intensity of ZVI,which mitigates iron particle agglomeration,increases Brunauer-Emmett-Teller(BET)surface area,and enhances FLO degradation efficiency.Furthermore,ZVI/SiC exhibits a much lower hydrogen evolution potential(HEP)and significantly higher corrosion currents compared to pure ZVI.FLO was proposed to undergo degradation via reductive dechlorination,involving a hydrogenolysis mechanism that entails the cleavage of theσbond.This study provides new insights into the reduction hydrogenation mechanism of ZVI.
基金Supported by the National Key R&D Program of China(No.2017YFB0404000)the Project of Liaoning Ocean and Fisheries Department(No.201731)+1 种基金the Foundation of Key Laboratory of Industrial Ecology and Environmental Engineering Ministry of Education(No.KLIEEE-17-12)the High-level Innovation Team Overseas Training Project of Liaoning Provincial(No.201818)
文摘Antibiotics are widespread in various environmental media,and may pose a potential threat to aquatic ecosystems and non-target aquatic organisms.Florfenicol(FLO)is one of the most commonly used antibiotics in aquaculture,and extensively used to substitute chloramphenicol with its strong sterilization and low adverse ef fect.In this study,flounder Paralichthys olivaceus,an important economic fish species in seawater was used as an experimental subject.Five exposure concentrations of FLO(including environmentrelated concentrations)were set at 0,0.01,0.1,1,and 10 mg/L.Ef fects of FLO exposure for 168 h on growth and development,motor behavior,antioxidant enzyme activity,malondialdehyde(MDA)content,and thyroid hormone level of P.olivaceus larvae were studied in pre-larvae(1 dpf)and post-larvae(20 dpf).The results show that the short-term FLO exposure could promote the larvae growth to some degrees,but inhibit them as the exposure time prolonged.For pre-larvae,FLO at 0.01 mg/L could stimulate the motor nerve system and increase the swimming ability,but inhibited it at 1 mg/L.With the increasing dosage of FLO,the superoxide dismutase(SOD)and MDA contents were elevated,reaching the maximum in the 1 mg/L FLO group.The pre-larvae were more sensitive than the post-larvae to FLO in the environment,and the growth and immune resistance could be damaged with long exposure.Post-larvae were more tolerant to external pollutants,FLO at 1 mg/L could promote the motor behavior and reduce SOD and MDA contents.Therefore,FLO can be used as an antibiotic at a proper concentration but as a drug to prevent disease in a long-term way.
基金kindly funded by National Natural Science Foundation of China(No.51978319)Outstanding Youth Foundation of Gansu Province(No.20JR10RA651)+1 种基金Natural Science Foundation of Gansu Province(No.20JR5RA242 and 20JR10RA635)Natural Science Project of University Research Program of Xinjiang Uygur Autonomous Region(No.XJEDU2017M035)。
文摘Eggshell-loaded CoFe_(2)O_(4) catalyst was synthesized via a convenient hydrothermal method during our work,then the surface morphology and elemental composition of the composites were systematically investigated.Performance of CoFe_(2)O_(4)/eggshell-activated peroxymonosulfate(PMS)system was evaluated by selecting florfenicol(FF)as the model pollutant,and effects of operating parameters and water matrices on the FF removal efficiency in this system were investigated.In addition,main radicals involved in FF degradation were identified by EPR tests and radical quenching experiments,and possible mechanism was proposed.The reduction of toxicity during FF degradation was confirmed,and in combination with HP-LC tests,it was found that dehalogenation and defluorination were effectively carried out during FF degradation.In addition,the prepared CoFe_(2)O_(4)polyvinylidene fluoride(PVDF)membrane effectively improved the stability of the material and reduced the precipitation of metals.
文摘[Objective] The paper was to study in vitro pharmacodynamics characteristics of florfenicol dual suspension emulsion (DSEF). [Method] The florfenicol injection (FI) was used as the control group, the minimal inhibitory concentration (MIC), minimal bactericide concentration (MBC) and mutant selection window (MSW) of florfenicol dual suspension emulsion on 5 kinds of bacteria were determined. The post-antibiotic effect (PAE) and post-antibiotic sub-MIC effect (PASME) of Salmonella typhimurium were also measured. [Result] Compared with the ordinary injection, the MIC and MBC of florfenicol dual suspension emulsion on 5 kinds of bacteria showed no obvious changes. However, florfenicol dual suspension emulsion obviously narrowed MSW of 5 kinds of bacteria (P<0.01), which also significantly extended PAE and PASME of S. typhimurium (P<0.01). [Conclusion] The florfenicol dual suspension emulsion in vitro can reduce the probability of bacterial resistance, significantly prolong after effect time of antibiotics on bacteria, thereby effectively improving the antibacterial effect.
基金supported by the National Natural Science Foundation of China(32072920)the National Key Research and Development Program of China(2017YFD0501402)+1 种基金the Fundamental Research Funds for the Central Universities(2662022DKPY007)the HZAU-AGIS Cooperation Fund(SZYJY2022024).
文摘Doxycycline hydrochloride and florfenicol combination(DoxHcl&FF)is an effective treatment for respiratory diseases.In the study,our objective Was to evaluate the activity of DoxHcl&FF against Actinobacillus pleuropneumoniae(APP)in porcine pulmonary epithelial lining fluid(PELF)and the optimal dosage scheme to avoid the development of resistance.The DoxHcl&FF Was administered intramuscularly(IM)at 20mg/kg,and the PELF was collected at differ-ent time points.The minimum inhibitory concentration(MIC)and time-mortality curves were also included in the study.Based on the sigmoid Emax equation and dose equations,the study integrated the in vivo pharmacokinetic data of infected pigs and ex vivo pharmacodynamic data to obtain the area under concentration time curve(AUCo-24h)MIC values in PELF and achieve bacteriostatic activity,bactericidal activity and the virtual eradication of bacteria.The study showed that the combination of DoxHcl and FF caused no significant changes in PK parameters.The peak concentration(Cmax)of FF in healthy and diseased pigs was 8.87±0.08 and 8.67±0.07μg/mL,the_AUCo-24h were.172.75±2.52 and 18022±3.13 h-μg/mL,the Cmax of DoxHcl was 7.91±0.09 and 7.99±0.05μg/mL,and the AUCo-24h was 129.96±3.70 h-μg/mL and 169.82±4.38 h-μg/mL.DoxHcl&FF showed strong concentra-tion-dependent tendencies.The bacteriostatic,bactericidal,and elimination activity were calculated as 5.61,18.83 and 32.68 h,and the doses were 1.37(bacteriostatic),4.59(bactericidal)and 7.99(elimination)mg/kg.These findings indicated that the calculated recommended dose could assist in achieving more precise administration,increasing the effectiveness of DoxHcl&FF treatment for APP infections.
基金Supported by National Natural Science Foundation of China(No.40973073,40830744)Project of Leading Disciplinary Studies in Shanghai(No.S30109)+1 种基金National Key Technology R&D Program in the 11th Five-year-plan of China(No.2008BAC32B03,2009BAA24B04)Municipal Natural Science Foundation of Shanghai(No.09ZR1411300)
文摘Thiamphenicol(THA) and florfenicol(FLO) aqueous solutions were irradiated to different doses by 1 MeV electron beams,and redox reactions of THA/FLO and radicals of OH,e_(eq)^- and ~·H were investigated under various conditions.The results showed that at 8 kGy,the decomposition rate of THA and FLO was 97.2%and 98.5%, respectively.Quantitative and qualitative analysis indicated that OH played a key role in E-beam degradation of the THA and FLO in aqueous solutions,and e_(eq)^- and ~·H radicals could initiate the degradation,too.Seven primary products of the THA and FLO degradation were identified.These indicate that E-beam radiation is an effective method to reduce THA and FLO in aqueous solutions.
