【目的】利用石墨烯与多壁碳纳米管复合材料协同刃天青修饰微生物燃料电池(Microbial fuel cell,MFC)阳极,提高MFC的运行性能。【方法】以碳布为基底,采用滴涂法分别制备了刃天青/碳布(R/CC)、刃天青+石墨烯/碳布(R+GNS/CC)、刃天青+多...【目的】利用石墨烯与多壁碳纳米管复合材料协同刃天青修饰微生物燃料电池(Microbial fuel cell,MFC)阳极,提高MFC的运行性能。【方法】以碳布为基底,采用滴涂法分别制备了刃天青/碳布(R/CC)、刃天青+石墨烯/碳布(R+GNS/CC)、刃天青+多壁碳纳米管/碳布(R+MWCNT/CC)、刃天青+石墨烯+多壁碳纳米管/碳布(R+GNS+MWCNT/CC)四种阳极材料。【结果】在降解高氯酸盐的过程中,与刃天青/碳布(最高输出电压54 m V)相比,刃天青+石墨烯/碳布、刃天青+多壁碳纳米管/碳布和刃天青+石墨烯+多壁碳纳米管/碳布阳极MFC最高输出电压分别为87、145、275 m V,分别提高了61.11%、168.52%、409.26%;高氯酸盐的还原速率也分别提高了59.1%、89.7%、147.3%。4种阳极的电化学交流阻抗(EIS)和塔菲尔(Tafel)测试发现,与刃天青/碳布阳极相比,刃天青+石墨烯/碳布、刃天青+多壁碳纳米管/碳布阳极活化内阻减小,电极反应速率提高,但刃天青+石墨烯+多壁碳纳米管/碳布阳极的活化内阻更小,电极反应速率更快,同时4种阳极附着微生物胞外聚合物(EPS)分析表明,修饰过的阳极附着微生物数量增加,多糖减少,R+GNS+MWCNT/CC阳极变化最大,更有利于微生物传递电子。【结论】石墨烯、多壁碳纳米管复合材料协同刃天青修饰MFC阳极可以减小活化内阻从而加快电子传递,进而提高MFC的性能。展开更多
AIM: To investigate collagen patches seeded with mesenchymal stem cells(MSCs) and/or tenocytes(TCs) with regards to their suitability for anterior cruciate ligament(ACL) repair. METHODS: Dynamic intraligamentary stabi...AIM: To investigate collagen patches seeded with mesenchymal stem cells(MSCs) and/or tenocytes(TCs) with regards to their suitability for anterior cruciate ligament(ACL) repair. METHODS: Dynamic intraligamentary stabilization utilizes a dynamic screw system to keep ACL remnants in place and promote biological healing, supplemented by collagen patches. How these scaffolds interact with cells and what type of benefit they provide has not yet been investigated in detail. Primary ACL-derived TCs and human bone marrow derived MSCs were seeded onto two different types of 3D collagen scaffolds, Chondro-Gide?(CG) and Novocart?(NC). Cells were seeded onto the scaffolds and cultured for 7 d either as a pure populations or as "premix" containing a 1:1 ratio of TCs to MSCs. Additionally, as controls, cells were seeded in monolayers and in co-cultures on both sides of porous high-density membrane inserts(0.4 μm). We analyzed the patches by real time polymerase chain reaction, glycosaminoglycan(GAG), DNA and hydroxyproline(HYP) content. To determine cell spreading and adherence in the scaffolds microscopic imaging techniques, i.e., confocal laser scanning microscopy(c LSM) and scanning electron microscopy(SEM), were applied.RESULTS: CLSM and SEM imaging analysis confirmed cell adherence onto scaffolds. The metabolic cell activity revealed that patches promote adherence and proliferation of cells. The most dramatic increase in absolute metabolic cell activity was measured for CG samples seeded with tenocytes or a 1:1 cell premix. Analysis of DNA content and c LSM imaging also indicated MSCs were not proliferating as nicely as tenocytes on CG. The HYP to GAG ratio significantly changed for the premix group, resulting from a slightly lower GAG content, demonstrating that the cells are modifying the underlying matrix. Real-time quantitativepolymerase chain reaction data indicated that MSCs showed a trend of differentiation towards a more tenogenic-like phenotype after 7 d.CONCLUSION: CG and NC are both cyto-compatible with primar展开更多
Development of viable cell estimation method without sacrificing proliferation and functions of cells cultured on regenerative biomaterials is essential for regenerative engineering.Cytotoxicity and depletion of resaz...Development of viable cell estimation method without sacrificing proliferation and functions of cells cultured on regenerative biomaterials is essential for regenerative engineering.Cytotoxicity and depletion of resazurin are critical but often overlooked limitations that hindered applications of resazurin in viable cell estimation.The present work found that cytotoxicity and depletion of resazurin depended on cell concentration,resazurin concentration and resazurin incubation time.A simple strategy which only allowed cells to incubate with resazurin during each measurement was developed to eliminate negative effects of resazurin.This strategy was verified by monitoring proliferation of MC3T3-E1 preosteoblasts on poly(D,L-lactic acid)scaffold during a continuous 3D culture process for up to 21 days,comparing the accuracy with MTT assay which is a destructive assay with high sensitivity and accuracy and commonly used in regenerative engineering and comparing viability,proliferation and differentiation functions of MC3T3-E1,which were treated with/without this strategy for nondestructive evaluation.This method showed comparable linearity of standard curve and characteristics of growth curve to MTT assay.No major negative effects of this method on MC3T3-E1 viability and functions were found.Our work highlighted the importance of the concentration and incubation time of resazurin in designing application-specific nondestructive viability assay and would be helpful in improving the implanted medical devices as well as in regenerative engineering.展开更多
Aim:To assess that metabolic status of spermatozoa could provide a useful tool for evaluation of semen quality. Methods:The accuracy of the spectrophotometric application of the resazurm reduction assay was assessed u...Aim:To assess that metabolic status of spermatozoa could provide a useful tool for evaluation of semen quality. Methods:The accuracy of the spectrophotometric application of the resazurm reduction assay was assessed using receiver operating characteristic(ROC)analysis.Results:Areas under ROC curves(AUC)for motile sperm concen- tration and sperm index(SI)(sperm concentration multiplied by the square root of percentage sperm motility multi- plied by the percentage normal sperm morphology)were 0.922.The best discrimination between poor and good semen samples according to the SI was achieved at a cut-off point of A_(610)=0.209,where high sensitivity(94.1%)and specificity(91.7%)were calculated.The assay was less accurate when motile sperm concentration was used as the criterion value,vielding sensitivity of 88.2% and specificity of 87.5%,respectively,Likelihood ratios(LR)indicate that absorbances lower than 0.209 were at least 11.3 times as likely to be found in good semen samples than those in poor according to the SI,whereas in the case of motile sperm concentration,the LR was calculated to be 7.06.Conclusion: These results show that the resazurin reduction assay combined with spectrophotometry is an accurate method of assessing the quality of boar semen.展开更多
A monitoring method of biofouling in reverse osmosis(RO) system was proposed based on the fluorescent signal of resorufin, which is reduced by nicotinamide adenine dinucleotide released from viable cells during aerobi...A monitoring method of biofouling in reverse osmosis(RO) system was proposed based on the fluorescent signal of resorufin, which is reduced by nicotinamide adenine dinucleotide released from viable cells during aerobic respiration. The fluorescent signal of resorufin reduced by planktonic cells and microorganisms of biofilm showed linearity, indicating its feasibility to monitor biofouling in a RO system. For the application of the method to the lab-scale RO system, the injection concentration of resazurin and the injection flow rate were optimized. Biofilm on RO membranes continuously operated in a lab-scale RO system was estimated by resorufin fluorescence under optimized detection condition. As a result,resorufin fluorescence on RO membrane showed a significant increase in which the permeability of RO system decreased by 30.48%. Moreover, it represented the development of biofilm as much as conventional biofilm parameters such as adenosine triphosphate,extracellular polymeric substances, and biofilm thickness. The proposed method could be used as a sensitive and low-cost technology to monitor biofouling without autopsy of membranes.展开更多
Aim: This study was undertaken to compare the reduction in color of two dyes methylene blue (MBRT) and resazurindye (RRT) with other tests of bull semen quality and to examine their relationship to fertility. Methods:...Aim: This study was undertaken to compare the reduction in color of two dyes methylene blue (MBRT) and resazurindye (RRT) with other tests of bull semen quality and to examine their relationship to fertility. Methods: One hundredsixty-four ejaculates from 59 bulls were examined, processed, and used for 30 016 inseminations. Results: Bulls usedin artificial insemination have been selected for high semen quality and fertility, and semen from these bulls averaged80.6 % unstained sperm, only 11% had abnormalities, and fertility ranged from 64 %to 76 %. The MBRT and RRTwere run with standardized sperm numbers to prevent sperm concentration from influencing the dye reduction time. Ashort RRT was correlated with higher fertility ( r = -0.26) but MBRT was not correlated ( r = -0.05, P >0.0,5).The correlations were low, but axe typical and reflect the statistical effect of the large binomial variance associated withpregnancy or nonpregnancy being coded as 1 or O. Conclusion: The fact that the RRT was significantly correlated withfertility when sperm numbers were standardized, and published reports that resazurin is useful for monitoring other semencharacteristics, indicate that this dye may provide valuable information not given by other simple laboratory tests. (AsianJ Androl 1999 Sep; 1: 109 - 114 )展开更多
Aim： To assess that metabolic status of spermatozoa could provide a useful tool for evaluation of semen quality. Methods： The accuracy of the spectrophotometric application of the resazurin reduction assay was asses...Aim： To assess that metabolic status of spermatozoa could provide a useful tool for evaluation of semen quality. Methods： The accuracy of the spectrophotometric application of the resazurin reduction assay was assessed using receiver operating characteristic （ROC） analysis. Results： Areas under ROC curves （AUC） for motile sperm concentration and sperm index （SI） （sperm concentration multiplied by the square root of percentage sperm motility multiplied by the percentage normal sperm morphology） were 0.922. The best discrimination between poor and good semen samples according to the SI was achieved at a cut-off point of A610 = 0.209, where high sensitivity （94.1%） and specificity （91.7%） were calculated. The assay was less accurate when motile sperm concentration was used as the criterion value, yielding sensitivity of 88.2% and specificity of 87.5%, respectively. Likelihood ratios （LR） indicate that absorbances lower than 0.209 were at least 11.3 times as likely to be found in good semen samples than those in poor according to the SI, whereas in the case of motile sperm concentration, the LR was calculated to be 7.06. Conclusion： These results show that the resazurin reduction assay combined with spectrophotometry is an accurate method of assessing the quality of boar semen.展开更多
Medicinal plants have been known to treat simple to life-threatening diseases in different co<span><span style="font-family:Verdana;">mmunities of Nepal for many years. This study aims to analyze...Medicinal plants have been known to treat simple to life-threatening diseases in different co<span><span style="font-family:Verdana;">mmunities of Nepal for many years. This study aims to analyze the phytochemicals as plant secondary metabolites, evaluate the antioxidant and antibacterial activities of </span><i><span style="font-family:Verdana;">Rubus</span></i><span> <i><span style="font-family:Verdana;">ellipticus</span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">Ziziphus</span></i> <i><span style="font-family:Verdana;">mauritiana</span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">Pyrus</span></i> <i><span style="font-family:Verdana;">pashia</span></i><span style="font-family:Verdana;">,</span></span><span style="font-family:Verdana;"> and </span><i><span style="font-family:Verdana;">Drynaria</span></i><span style="font-family:Verdana;"> <i>coronans</i></span><span style="font-family:Verdana;"> extracts that are commonly being used as traditional medicine. Phytochemical analysis was performed to investigate the plant’s secondary metabolites such as polyphenols, alkaloids, flavonoids, terpenoids, reducing sugar, glycosides, tannins, carotene, phytosterols, coumarins, saponins, and anthracenes. The methanol extrac</span></span><span style="font-family:Verdana;">ts of the plants were used to evaluate the </span><i><span style="font-family:Verdana;">in vitro</span></i><span> </span><span style="font-family:Verdana;">antioxidant activity by using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical and the antibacterial activity against </span><i><span style="font-family:Verdana;">Staphylococcus</span></i> <i><span style="font-family:Verdana;">aureus</span></i><span style="font-family:Verdana;"> (ATCC 25923), </span><i><span style="font-family:Verdana;">Klebsiella</span></i><span style="font-family:Verdana;"> <i>pneumoniae</i></span> <span style="font-family:Verdana;">(ATCC 700603),</span> <i><span style="font-family:Verdana;">Escherichia<展开更多
Multiple drug resistant(MDR)and methicillin-resistant Staphylococcus aureus(MRSA)have become increasingly prevalent as a community acquired infection.As a result limited treatment options are available with convention...Multiple drug resistant(MDR)and methicillin-resistant Staphylococcus aureus(MRSA)have become increasingly prevalent as a community acquired infection.As a result limited treatment options are available with conventional synthetic antibiotics.Bioprospecting natural products with potent antimicrobial activity show promise for developing new drugs against this pathogen.In this study,we have investigated the antimicrobial activity of a purple violet pigment(PVP)from an Antarctic bacterium,Janthinobacterium sp.Ant5-2 on 15 clinical MDR and MRSA strains.The colorimetric resazurin assay was employed to determine the minimum inhibitory concentration(MIC90)of PVP against MDR and MRSA.The MIC90 ranged between 1.57μg/mL and 3.13μg/mL,which are significantly lower than many antimicrobials tested from natural sources against this pathogen.The spectrophotometrically determined growth analysis and total microscopic counts using Live/dead®BacLight™fluorescent stain exhibited a steady decrease in viability of both MDR and MRSA cultures following treatment with PVP at the MIC levels.In silico predictive molecular docking study revealed that PVP could be a DNA-targeting minor groove binding antimicrobial compound.The continued development of novel antimicrobials derived from natural sources with the combination of a suite of conventional antibiotics could stem the rising pandemic of MDR and MRSA along with other deadly microbial pathogens.展开更多
Objective:Fresh marine seaweeds Gracilaria edulis,Gracillaria verrcosa,Acanthospora spicifera,Ulva facita,Ulva lacta(U.lacta),Kappaphycus spicifera,Sargassum ilicifolium,Sargassum wightii(S.wightii),Padina tetramatica...Objective:Fresh marine seaweeds Gracilaria edulis,Gracillaria verrcosa,Acanthospora spicifera,Ulva facita,Ulva lacta(U.lacta),Kappaphycus spicifera,Sargassum ilicifolium,Sargassum wightii(S.wightii),Padina tetramatica and Padina gymonospora were collected from Mandapam(Rameshwaram,Tamil Nadu)of South East coast of India and were screened for antibacterial activity.Methods:All the collected seaweeds were extracted by using five different solvent(methanol,isopropanol,acetone,chloroform,diethyl ether)to study their extracts against fish pathogenic bacteria V.alginolyticus(VA09)purchased from MTCC.And minimum inhibition carried out by using Resazurin micro-titre assay.Crude extract of S.wightii analysied by FTIR.Results:The methanolic extract of S.wightii produced a maximum zone of inhibition(1.95±0.11)cm,isopropanol extract maximum inhibition was produced by S.wightii(1.93±0.78)cm,Acetone extract of Gracilaria verrcosa showed maximum zone of inhibition(1.36±0.05)cm,chloroform extract of S.wightii produced a maximum zone(1.56±0.25)cm and diethyl ether extract of S.wightii produced maximum zone of inhibition(1.86±0.11)cm.Based on the antibacterial activity S.wightii,U.lacta and Padina tetramatica showed best antibacterial activity against Vibrio harveyi.In this three seaweeds were taken for MIC study.The S.wightii methanolic extract,U.lacta diethyl ether extract and Padina tetramatica methanolic extract showed a higher MIC values,and despectively were 25 mg/mL,50 mg/mL and 50 mg/mL.FTIR result showed that mostly phenolic compounds were present in the S.wightii.Conclusions:Based on the FTIR result S.wightii have high amount of phenolic compound.Phenolic compound have the good antimicrobial activity.The results clearly show that seaweedS.wightii is an interesting source for biologically active compounds that may be applied for prophylaxis and therapy of bacterial fish diseases and it should be used for immunostimulation activity in aquaculture.展开更多
文摘【目的】利用石墨烯与多壁碳纳米管复合材料协同刃天青修饰微生物燃料电池(Microbial fuel cell,MFC)阳极,提高MFC的运行性能。【方法】以碳布为基底,采用滴涂法分别制备了刃天青/碳布(R/CC)、刃天青+石墨烯/碳布(R+GNS/CC)、刃天青+多壁碳纳米管/碳布(R+MWCNT/CC)、刃天青+石墨烯+多壁碳纳米管/碳布(R+GNS+MWCNT/CC)四种阳极材料。【结果】在降解高氯酸盐的过程中,与刃天青/碳布(最高输出电压54 m V)相比,刃天青+石墨烯/碳布、刃天青+多壁碳纳米管/碳布和刃天青+石墨烯+多壁碳纳米管/碳布阳极MFC最高输出电压分别为87、145、275 m V,分别提高了61.11%、168.52%、409.26%;高氯酸盐的还原速率也分别提高了59.1%、89.7%、147.3%。4种阳极的电化学交流阻抗(EIS)和塔菲尔(Tafel)测试发现,与刃天青/碳布阳极相比,刃天青+石墨烯/碳布、刃天青+多壁碳纳米管/碳布阳极活化内阻减小,电极反应速率提高,但刃天青+石墨烯+多壁碳纳米管/碳布阳极的活化内阻更小,电极反应速率更快,同时4种阳极附着微生物胞外聚合物(EPS)分析表明,修饰过的阳极附着微生物数量增加,多糖减少,R+GNS+MWCNT/CC阳极变化最大,更有利于微生物传递电子。【结论】石墨烯、多壁碳纳米管复合材料协同刃天青修饰MFC阳极可以减小活化内阻从而加快电子传递,进而提高MFC的性能。
基金Supported by A grant of the Swiss Orthopaedics Society(SGOT)to Ahmad SS,No.S99083814080618560
文摘AIM: To investigate collagen patches seeded with mesenchymal stem cells(MSCs) and/or tenocytes(TCs) with regards to their suitability for anterior cruciate ligament(ACL) repair. METHODS: Dynamic intraligamentary stabilization utilizes a dynamic screw system to keep ACL remnants in place and promote biological healing, supplemented by collagen patches. How these scaffolds interact with cells and what type of benefit they provide has not yet been investigated in detail. Primary ACL-derived TCs and human bone marrow derived MSCs were seeded onto two different types of 3D collagen scaffolds, Chondro-Gide?(CG) and Novocart?(NC). Cells were seeded onto the scaffolds and cultured for 7 d either as a pure populations or as "premix" containing a 1:1 ratio of TCs to MSCs. Additionally, as controls, cells were seeded in monolayers and in co-cultures on both sides of porous high-density membrane inserts(0.4 μm). We analyzed the patches by real time polymerase chain reaction, glycosaminoglycan(GAG), DNA and hydroxyproline(HYP) content. To determine cell spreading and adherence in the scaffolds microscopic imaging techniques, i.e., confocal laser scanning microscopy(c LSM) and scanning electron microscopy(SEM), were applied.RESULTS: CLSM and SEM imaging analysis confirmed cell adherence onto scaffolds. The metabolic cell activity revealed that patches promote adherence and proliferation of cells. The most dramatic increase in absolute metabolic cell activity was measured for CG samples seeded with tenocytes or a 1:1 cell premix. Analysis of DNA content and c LSM imaging also indicated MSCs were not proliferating as nicely as tenocytes on CG. The HYP to GAG ratio significantly changed for the premix group, resulting from a slightly lower GAG content, demonstrating that the cells are modifying the underlying matrix. Real-time quantitativepolymerase chain reaction data indicated that MSCs showed a trend of differentiation towards a more tenogenic-like phenotype after 7 d.CONCLUSION: CG and NC are both cyto-compatible with primar
基金supported by the National Natural Science Foundation of China(31771019,11172031,11827803,and 31470901)The National Key Research and Development Plan(2016YFC1101101)International Joint Research Center of Aerospace Biotechnology and 344 Medical Engineering from Ministry of Science and Technology of China,111 Project 345(B13003).
文摘Development of viable cell estimation method without sacrificing proliferation and functions of cells cultured on regenerative biomaterials is essential for regenerative engineering.Cytotoxicity and depletion of resazurin are critical but often overlooked limitations that hindered applications of resazurin in viable cell estimation.The present work found that cytotoxicity and depletion of resazurin depended on cell concentration,resazurin concentration and resazurin incubation time.A simple strategy which only allowed cells to incubate with resazurin during each measurement was developed to eliminate negative effects of resazurin.This strategy was verified by monitoring proliferation of MC3T3-E1 preosteoblasts on poly(D,L-lactic acid)scaffold during a continuous 3D culture process for up to 21 days,comparing the accuracy with MTT assay which is a destructive assay with high sensitivity and accuracy and commonly used in regenerative engineering and comparing viability,proliferation and differentiation functions of MC3T3-E1,which were treated with/without this strategy for nondestructive evaluation.This method showed comparable linearity of standard curve and characteristics of growth curve to MTT assay.No major negative effects of this method on MC3T3-E1 viability and functions were found.Our work highlighted the importance of the concentration and incubation time of resazurin in designing application-specific nondestructive viability assay and would be helpful in improving the implanted medical devices as well as in regenerative engineering.
文摘Aim:To assess that metabolic status of spermatozoa could provide a useful tool for evaluation of semen quality. Methods:The accuracy of the spectrophotometric application of the resazurm reduction assay was assessed using receiver operating characteristic(ROC)analysis.Results:Areas under ROC curves(AUC)for motile sperm concen- tration and sperm index(SI)(sperm concentration multiplied by the square root of percentage sperm motility multi- plied by the percentage normal sperm morphology)were 0.922.The best discrimination between poor and good semen samples according to the SI was achieved at a cut-off point of A_(610)=0.209,where high sensitivity(94.1%)and specificity(91.7%)were calculated.The assay was less accurate when motile sperm concentration was used as the criterion value,vielding sensitivity of 88.2% and specificity of 87.5%,respectively,Likelihood ratios(LR)indicate that absorbances lower than 0.209 were at least 11.3 times as likely to be found in good semen samples than those in poor according to the SI,whereas in the case of motile sperm concentration,the LR was calculated to be 7.06.Conclusion: These results show that the resazurin reduction assay combined with spectrophotometry is an accurate method of assessing the quality of boar semen.
基金supported by the National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIT) (No. 2018R1A2B2005745)
文摘A monitoring method of biofouling in reverse osmosis(RO) system was proposed based on the fluorescent signal of resorufin, which is reduced by nicotinamide adenine dinucleotide released from viable cells during aerobic respiration. The fluorescent signal of resorufin reduced by planktonic cells and microorganisms of biofilm showed linearity, indicating its feasibility to monitor biofouling in a RO system. For the application of the method to the lab-scale RO system, the injection concentration of resazurin and the injection flow rate were optimized. Biofilm on RO membranes continuously operated in a lab-scale RO system was estimated by resorufin fluorescence under optimized detection condition. As a result,resorufin fluorescence on RO membrane showed a significant increase in which the permeability of RO system decreased by 30.48%. Moreover, it represented the development of biofilm as much as conventional biofilm parameters such as adenosine triphosphate,extracellular polymeric substances, and biofilm thickness. The proposed method could be used as a sensitive and low-cost technology to monitor biofouling without autopsy of membranes.
文摘Aim: This study was undertaken to compare the reduction in color of two dyes methylene blue (MBRT) and resazurindye (RRT) with other tests of bull semen quality and to examine their relationship to fertility. Methods: One hundredsixty-four ejaculates from 59 bulls were examined, processed, and used for 30 016 inseminations. Results: Bulls usedin artificial insemination have been selected for high semen quality and fertility, and semen from these bulls averaged80.6 % unstained sperm, only 11% had abnormalities, and fertility ranged from 64 %to 76 %. The MBRT and RRTwere run with standardized sperm numbers to prevent sperm concentration from influencing the dye reduction time. Ashort RRT was correlated with higher fertility ( r = -0.26) but MBRT was not correlated ( r = -0.05, P >0.0,5).The correlations were low, but axe typical and reflect the statistical effect of the large binomial variance associated withpregnancy or nonpregnancy being coded as 1 or O. Conclusion: The fact that the RRT was significantly correlated withfertility when sperm numbers were standardized, and published reports that resazurin is useful for monitoring other semencharacteristics, indicate that this dye may provide valuable information not given by other simple laboratory tests. (AsianJ Androl 1999 Sep; 1: 109 - 114 )
文摘Aim： To assess that metabolic status of spermatozoa could provide a useful tool for evaluation of semen quality. Methods： The accuracy of the spectrophotometric application of the resazurin reduction assay was assessed using receiver operating characteristic （ROC） analysis. Results： Areas under ROC curves （AUC） for motile sperm concentration and sperm index （SI） （sperm concentration multiplied by the square root of percentage sperm motility multiplied by the percentage normal sperm morphology） were 0.922. The best discrimination between poor and good semen samples according to the SI was achieved at a cut-off point of A610 = 0.209, where high sensitivity （94.1%） and specificity （91.7%） were calculated. The assay was less accurate when motile sperm concentration was used as the criterion value, yielding sensitivity of 88.2% and specificity of 87.5%, respectively. Likelihood ratios （LR） indicate that absorbances lower than 0.209 were at least 11.3 times as likely to be found in good semen samples than those in poor according to the SI, whereas in the case of motile sperm concentration, the LR was calculated to be 7.06. Conclusion： These results show that the resazurin reduction assay combined with spectrophotometry is an accurate method of assessing the quality of boar semen.
文摘Medicinal plants have been known to treat simple to life-threatening diseases in different co<span><span style="font-family:Verdana;">mmunities of Nepal for many years. This study aims to analyze the phytochemicals as plant secondary metabolites, evaluate the antioxidant and antibacterial activities of </span><i><span style="font-family:Verdana;">Rubus</span></i><span> <i><span style="font-family:Verdana;">ellipticus</span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">Ziziphus</span></i> <i><span style="font-family:Verdana;">mauritiana</span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">Pyrus</span></i> <i><span style="font-family:Verdana;">pashia</span></i><span style="font-family:Verdana;">,</span></span><span style="font-family:Verdana;"> and </span><i><span style="font-family:Verdana;">Drynaria</span></i><span style="font-family:Verdana;"> <i>coronans</i></span><span style="font-family:Verdana;"> extracts that are commonly being used as traditional medicine. Phytochemical analysis was performed to investigate the plant’s secondary metabolites such as polyphenols, alkaloids, flavonoids, terpenoids, reducing sugar, glycosides, tannins, carotene, phytosterols, coumarins, saponins, and anthracenes. The methanol extrac</span></span><span style="font-family:Verdana;">ts of the plants were used to evaluate the </span><i><span style="font-family:Verdana;">in vitro</span></i><span> </span><span style="font-family:Verdana;">antioxidant activity by using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical and the antibacterial activity against </span><i><span style="font-family:Verdana;">Staphylococcus</span></i> <i><span style="font-family:Verdana;">aureus</span></i><span style="font-family:Verdana;"> (ATCC 25923), </span><i><span style="font-family:Verdana;">Klebsiella</span></i><span style="font-family:Verdana;"> <i>pneumoniae</i></span> <span style="font-family:Verdana;">(ATCC 700603),</span> <i><span style="font-family:Verdana;">Escherichia<
基金Research&Development Projects in Key Areas of Guangdong Province,China(2019B010933001)National Natural Science Foundation of China(21222402)+2 种基金National Basic Research Program of China(973 Program,2017YFE0197900)Innovation Training Program for College Students of Guangzhou University(XJ202011078036)Guangzhou Science and Technology Plan Project(202102010390)。
文摘Multiple drug resistant(MDR)and methicillin-resistant Staphylococcus aureus(MRSA)have become increasingly prevalent as a community acquired infection.As a result limited treatment options are available with conventional synthetic antibiotics.Bioprospecting natural products with potent antimicrobial activity show promise for developing new drugs against this pathogen.In this study,we have investigated the antimicrobial activity of a purple violet pigment(PVP)from an Antarctic bacterium,Janthinobacterium sp.Ant5-2 on 15 clinical MDR and MRSA strains.The colorimetric resazurin assay was employed to determine the minimum inhibitory concentration(MIC90)of PVP against MDR and MRSA.The MIC90 ranged between 1.57μg/mL and 3.13μg/mL,which are significantly lower than many antimicrobials tested from natural sources against this pathogen.The spectrophotometrically determined growth analysis and total microscopic counts using Live/dead®BacLight™fluorescent stain exhibited a steady decrease in viability of both MDR and MRSA cultures following treatment with PVP at the MIC levels.In silico predictive molecular docking study revealed that PVP could be a DNA-targeting minor groove binding antimicrobial compound.The continued development of novel antimicrobials derived from natural sources with the combination of a suite of conventional antibiotics could stem the rising pandemic of MDR and MRSA along with other deadly microbial pathogens.
基金Supported by Science and Engineering Research Board(SERB-F.No.SR/FT/LS-142/2009)Department of Science and Technology(DST),Government of India,New Delhi.
文摘Objective:Fresh marine seaweeds Gracilaria edulis,Gracillaria verrcosa,Acanthospora spicifera,Ulva facita,Ulva lacta(U.lacta),Kappaphycus spicifera,Sargassum ilicifolium,Sargassum wightii(S.wightii),Padina tetramatica and Padina gymonospora were collected from Mandapam(Rameshwaram,Tamil Nadu)of South East coast of India and were screened for antibacterial activity.Methods:All the collected seaweeds were extracted by using five different solvent(methanol,isopropanol,acetone,chloroform,diethyl ether)to study their extracts against fish pathogenic bacteria V.alginolyticus(VA09)purchased from MTCC.And minimum inhibition carried out by using Resazurin micro-titre assay.Crude extract of S.wightii analysied by FTIR.Results:The methanolic extract of S.wightii produced a maximum zone of inhibition(1.95±0.11)cm,isopropanol extract maximum inhibition was produced by S.wightii(1.93±0.78)cm,Acetone extract of Gracilaria verrcosa showed maximum zone of inhibition(1.36±0.05)cm,chloroform extract of S.wightii produced a maximum zone(1.56±0.25)cm and diethyl ether extract of S.wightii produced maximum zone of inhibition(1.86±0.11)cm.Based on the antibacterial activity S.wightii,U.lacta and Padina tetramatica showed best antibacterial activity against Vibrio harveyi.In this three seaweeds were taken for MIC study.The S.wightii methanolic extract,U.lacta diethyl ether extract and Padina tetramatica methanolic extract showed a higher MIC values,and despectively were 25 mg/mL,50 mg/mL and 50 mg/mL.FTIR result showed that mostly phenolic compounds were present in the S.wightii.Conclusions:Based on the FTIR result S.wightii have high amount of phenolic compound.Phenolic compound have the good antimicrobial activity.The results clearly show that seaweedS.wightii is an interesting source for biologically active compounds that may be applied for prophylaxis and therapy of bacterial fish diseases and it should be used for immunostimulation activity in aquaculture.
