AIM:To investigate the efficacy of the digitally reinforced hematoxylin-eosin polarization(DRHEP)technique for detection of amyloidosis in rectal biopsies.METHODS:One hundred hematoxylin-eosin(HE)stained rectal biopsi...AIM:To investigate the efficacy of the digitally reinforced hematoxylin-eosin polarization(DRHEP)technique for detection of amyloidosis in rectal biopsies.METHODS:One hundred hematoxylin-eosin(HE)stained rectal biopsies with Congo-red(CR)-positive amyloid depositions and 50 control cases with CRnegative amyloid-mimicking areas were scanned blinded to the CR results for amyloid depositions under both bright and polarized light,and digitally photographed using the DRHEP technique,to accentuate the faint birefringence observed in HE slides under polarization.The results of DRHEP and HE evaluation were statistically correlated with CR polarization results with respect to presence and localization of amyloid deposits as well as amyloid types.RESULTS:Amyloid deposits showed yellowish-green birefringence by DRHEP,which allowed identification of amyloidosis in 41 HE-unsuspected cases(P=0.016),31 of which only had vascular deposits.True positivity was higher,and false negativity and positivity were lower by DRHEP,compared to evaluation by HE(69%,31%,and 0.8%vs 33%,67%,and 33%,respectively;P<0.0001).The sensitivity,specificity,accuracy,and positive and negative predictive values for DRHEP were69%,98%,78.6%,98.5%,and 61.25%,respectively.Reasons for DRHEP false negativity were presence of extensive background birefringence in 12 cases,absence of CR birefringent vessel in 3 cases,and missing of the tiny deposits in 9 cases,which could be improved by experience,especially in the latter case.No correlation was found between age,gender,sites of deposits,or amyloid types.CONCLUSION:The DRHEP technique improves diagnostic accuracy when used as an adjunct or a prior step to CR staining,especially for cases with limited tissues for further analysis.展开更多
BACKGROUND Histopathologically stained archived tissue slides are stored in hospital archives for years to decades.They are the largest available source of biological materials and are a potentially useful resource th...BACKGROUND Histopathologically stained archived tissue slides are stored in hospital archives for years to decades.They are the largest available source of biological materials and are a potentially useful resource that can be used for retrospective epidemiological studies.DNA recovered from the slides can be used for several downstream molecular processes including polymerase chain reaction,single nucleotide polymorphism analysis,and whole genome sequencing.The DNA from these slides can be utilized to compare gene signatures of normal and diseased tissues.However,extraction of high-quality DNA from archived stained hematoxylin and eosin(H&E)slides remains challenging.AIM To standardize a new protocol for extracting DNA from archived H&E-stained tissue slides for further molecular assays.METHODS A total of 100 archived H&E-stained cancer slides were subjected to a total of five methods of DNA extraction.Methods were varied in the deparaffinization step,tissue rehydration,duration of lysis,and presence or absence of proteinase K.The extracted DNA was quantified using a NanoDrop spectrophometer and the quality was analyzed by agarose gel electrophoresis.Then each sample was subjected to polymerase chain reaction(PCR)to amplify the internal control gene GAPDH,thereby confirming the DNA intactness,which could be further utilized for other downstream applications.RESULTS Of the five different methods tested,the third method wherein xylene was used for tissue deparaffinization followed by 72 h of digestion and without proteinase K inactivation yielded the highest amount of DNA with good purity.The yield was significantly higher when compared to other methods.In addition,90%of the extracted DNA showed amplifiable GAPDH gene.CONCLUSION Here we present a step-by-step,cost-effective,and reproducible protocol for the extraction of PCR-friendly DNA from archived H&E-stained cancer tissue slides that can be used for further downstream molecular applications.展开更多
Purpose:.To compare the merits and limitations of hematoxylin-eosin(HE) and methyl violet staining for displaying ghost cells from vitreous or aqueous humor.Methods:.A specimen containing ghost cells was adjusted to f...Purpose:.To compare the merits and limitations of hematoxylin-eosin(HE) and methyl violet staining for displaying ghost cells from vitreous or aqueous humor.Methods:.A specimen containing ghost cells was adjusted to five different concentrations:(12×104,.10×104,.8×104, 6×104and 4×104cells / ml) and subjected to smearing and methyl violet and HE staining..The staining results were observed by light microscopy.Results: The ghost cells were readily observed at a cell density of > 8×104cells / ml with methyl violet staining,.but only a few cells were occasionally seen at lower cell densities..In contrast,.ghost cells were seen at all cell densities with HE staining.Conclusion: Methyl violet staining is more rapid and simpler for the identification of ghost cells, but its staining color more readily fades, the slides cannot be stored, and it is only effective at a cell density of > 8 ×104cells / ml. In contrast,.HE staining is more time-consuming but it can display cell morphology and distinguish cell components more explicitly and slides can be permanently stored. HE staining has advantages over methyl violet staining in detecting the ghost cells when the concentration is < 8×104cells / ml.展开更多
BACKGROUND Tumor-infiltrating lymphocytes(TILs)constitute a prognostic factor in hepatocellular carcinoma(HCC).However,different methods of assessing TILs have various pre-analytical,analytical,and post-analytical cha...BACKGROUND Tumor-infiltrating lymphocytes(TILs)constitute a prognostic factor in hepatocellular carcinoma(HCC).However,different methods of assessing TILs have various pre-analytical,analytical,and post-analytical challenges.The evaluation of TILs in hematoxylin and eosin(H&E)-stained tumor sections proposed by the International Immuno-Oncology Biomarker Working Group was demonstrated to be a reproducible,affordable and easily applied method in many tumors.AIM To evaluate the prognostic significance of TILs in H&E-stained slides of HCCs.METHODS This was a retrospective study performed in the hospital.HCC patients who underwent liver resection between 2015 and 2017 in Zhongshan Hospital were enrolled in this study.Patients who experienced recurrence or received therapy in addition to antiviral therapy before surgery at this time were excluded.A total of 204 patients were enrolled in the study.The ILs were counted manually in tumor sections stained with H&E under an optical microscope at 400×.The ILs were assessed separately in the center of the tumor(TILs^(CT)),the invasive front(TILs^(IF)),and peritumor(PILs)areas.Univariate and multivariate survival analyses were performed using a Cox regression model.P<0.05 was considered statistically significant and all P-values were two-sided.RESULTS Among the 204 patients,univariate analysis indicated that macrovascular invasion(MaVI)(P=0.001),microvascular invasion(MVI)(P=0.012),multiple tumors(P=0.008),large tumors(>10 cm)(P=0.001),absence of a tumor capsule(P=0.026),macrotrabecular histological subtype(P=0.001),low density of TILs^(CT)(P=0.039),TILs^(IF)(P=0.014),and PILs(P=0.010)were predictors of progressionfree survival(PFS).Cox multivariate analysis indicated that MaVI(P=0.009),absence of a tumor capsule(P=0.031),low-density of TILs^(IF)(P=0.047)and PILs(P=0.0495)were independent predictors of PFS.A three-category analysis was carried out by combining TILs^(CT),TILs^(IF),and PILs,after which HCCs were classified into immune^(high)[(TILs^(CT))^(high),(TILs^(IF))^(high),and PILs^(high),83 cases],immune^(mod)(tumors other than immune^(high) and immune^(low) subtypes,94 cases),and immune^(low)[(TILs^(CT))^(low),(TILs^(IF))^(low),and PILs^(low),27 cases]subtypes.The immune^(high) subtype had a lower rate of MVI(40.96%)than the immune^(mod)(61.70%,P=0.017)and immune^(low)(66.67%,P=0.020)subtypes.The recurrence rates of the immune^(high),immune^(mod) and immune^(low) subtypes were 10.8%,25.5%and 33.3%,respectively.CONCLUSION HCC patients with high infiltrating lymphocytes tend to have a lower recurrence rate and less MVI.The evaluation of TILs in H&E-stained specimens could be a prognostic parameter for HCC.展开更多
BACKGROUND Diabetes is known damage the liver and kidney,leading to hepatic dysfunction and kidney failure.Honey is believed to help in lowering the blood glucose levels of diabetic patients and reducing diabetic comp...BACKGROUND Diabetes is known damage the liver and kidney,leading to hepatic dysfunction and kidney failure.Honey is believed to help in lowering the blood glucose levels of diabetic patients and reducing diabetic complications.However,the effect of stingless bee honey(SBH)administration in relieving liver and kidney damage in diabetes has not been well-studied.AIM To investigate the effect of SBH administration on the kidney and liver of streptozotocin-induced(STZ;55 mg/kg)diabetic Sprague Dawley rats.METHODS The rats were grouped as follows(n=6 per group):non-diabetic(ND),untreated diabetic(UNT),metformin-treated(MET),and SBH+metformin-treated(SBME)groups.After successful diabetic induction,ND and UNT rats were given normal saline,whereas the treatment groups received SBH(2.0 g/kg and/or metformin(250 mg/kg)for 12 d.Serum biochemical parameters and histological changes using hematoxylin and eosin(H&E)and periodic acid–Schiff(PAS)staining were evaluated.RESULTS On H&E and PAS staining,the ND group showed normal architecture and cellularity of Bowman’s capsule and tubules,whereas the UNT and MET groups had an increased glomerular cellularity and thickened basement membrane.The SBH-treated group showed a decrease in hydropic changes and mild cellularity of the glomerulus vs the ND group based on H&E staining,but the two were similar on PAS staining.Likewise,the SBME-treated group had an increase in cellularity of the glomerulus on H&E staining,but it was comparable to the SBH and ND groups on PAS staining.UNT diabetic rats had tubular hydropic tubules,which were smaller than other groups.Reduced fatty vacuole formation and dilated blood sinusoids in liver tissue were seen in the SBH group.Conversely,the UNT group had high glucose levels,which subsequently increased MDA levels,ultimately leading to liver damage.SBH treatment reduced this damage,as evidenced by having the lowest fasting glucose,serum alanine transaminase,aspartate transaminase,and alkaline phosphatase levels compared to other groups,although the levels of liver enzymes were not statistically significant.CONCLUSION The cellularity of the Bowman’s capsule,as well as histological alteration of kidney tubules,glomerular membranes,and liver tissues in diabetic rats after oral SBH resembled those of ND rats.Therefore,SBH exhibited a protective hepatorenal effect in a diabetic rat model.展开更多
Removal of dye Eosin on two different samples of activated carbon by static batch method was studied. Experimental data on optical density of blank solutions of different concentrations ranging from 10 to 100 mg/L and...Removal of dye Eosin on two different samples of activated carbon by static batch method was studied. Experimental data on optical density of blank solutions of different concentrations ranging from 10 to 100 mg/L and optical density of solutions after adsorption on activated carbon samples were taken and analyzed. Calibration curves were plotted and the amount of dye adsorbed was calculated. The data was fitted to Langmuir and Freundlich isotherms for two different carbon samples and different concentration values. Constants were calculated from the slope and intercept values of the isotherms. Coefficient of correlation R2 and Standard Deviation SD were also noted. The data fitted well to the iso- therms. It was observed that adsorption decreased with increase in ppm concentrations. Carbon sample C2 showed higher potential to adsorb the dye Eosin as compared to carbon sample C1. Further Carbon sample C2 showed better adsorption in acidic pH as compared to in alkaline pH. From the analysis of the data it is shown that C2 sample has a good capacity to remove the textile dye from the residue water.展开更多
This paper describes a novel method for the degradation of eosin by using glow discharge electrolysis （GDE）. The effects of various parameters on the removal efficiency were studied. It was found that the eosin degr...This paper describes a novel method for the degradation of eosin by using glow discharge electrolysis （GDE）. The effects of various parameters on the removal efficiency were studied. It was found that the eosin degradation could be raised considerably by increasing the applied voltage and the initial concentration, or by decreasing pH of the aqueous solution. Fe^2＋ ion had an evident accelerating effect on the eosin degradation. The degradation process of eosin obeyed a pseudo-first-order reaction. The relationship between the degradation rate constant k and the reaction temperature T could be expressed by Arrhenius equation with which the apparent activation energy Ea of 14.110 kJ· mol^-1 and the pre-exponential factor k0 of 2.065× 10^-1 min^-1 were obtained, too. The determination of hydroxyl radical was carried out by using N, N-dimethyl -p-nitrosoaniline （RNO） as a scavenger. The results showed that the hydroxyl radical plays an important role in the degradation process.展开更多
The adsorptive precipitation between eosin Y （EY） and AgCl colloids at pH 3.73 caused the sensitive color change of the solution. The reaction mechanism between EY and AgCl was analyzed and this reaction was used fo...The adsorptive precipitation between eosin Y （EY） and AgCl colloids at pH 3.73 caused the sensitive color change of the solution. The reaction mechanism between EY and AgCl was analyzed and this reaction was used for determination of Cl^- in trace level by the light-absorption radio variation approach.展开更多
The role of oxygen and the generation of active radicals in the photocatalitic degradation of phenol were investigated using the eosin sensitized TiO2 as photocatalyst under visible light irradiation. Diffuse reflecta...The role of oxygen and the generation of active radicals in the photocatalitic degradation of phenol were investigated using the eosin sensitized TiO2 as photocatalyst under visible light irradiation. Diffuse reflectance spectra show that the absorbancy range of eosin/TiO2 is expanded from 378 nm (TiO2 ) to about 600 nm. The photocatalitic degradation of phenol is almost stopped when the eosin/TiO2 system is saturated with N2 , which indicates the significance of O2 . The addition of NaN 3 (a quencher of single oxygen) causes about a 62% decrease in the phenol degradation. The phenol degradation ratio is dropped from 92% to 75% when the isopropanol (a quencher of hydroxyl radical) is present in the system. The experimental results show that there are singlet oxygen and hydroxyl radical generated in the eosin/TiO2 system under visible light irradiation. The changes of absorbancy indicate that the hydrogen peroxide might be produced. Through the analysis and comparison, it is found that the singlet oxygen is the predominant active radical for the degradation of phenol.展开更多
文摘AIM:To investigate the efficacy of the digitally reinforced hematoxylin-eosin polarization(DRHEP)technique for detection of amyloidosis in rectal biopsies.METHODS:One hundred hematoxylin-eosin(HE)stained rectal biopsies with Congo-red(CR)-positive amyloid depositions and 50 control cases with CRnegative amyloid-mimicking areas were scanned blinded to the CR results for amyloid depositions under both bright and polarized light,and digitally photographed using the DRHEP technique,to accentuate the faint birefringence observed in HE slides under polarization.The results of DRHEP and HE evaluation were statistically correlated with CR polarization results with respect to presence and localization of amyloid deposits as well as amyloid types.RESULTS:Amyloid deposits showed yellowish-green birefringence by DRHEP,which allowed identification of amyloidosis in 41 HE-unsuspected cases(P=0.016),31 of which only had vascular deposits.True positivity was higher,and false negativity and positivity were lower by DRHEP,compared to evaluation by HE(69%,31%,and 0.8%vs 33%,67%,and 33%,respectively;P<0.0001).The sensitivity,specificity,accuracy,and positive and negative predictive values for DRHEP were69%,98%,78.6%,98.5%,and 61.25%,respectively.Reasons for DRHEP false negativity were presence of extensive background birefringence in 12 cases,absence of CR birefringent vessel in 3 cases,and missing of the tiny deposits in 9 cases,which could be improved by experience,especially in the latter case.No correlation was found between age,gender,sites of deposits,or amyloid types.CONCLUSION:The DRHEP technique improves diagnostic accuracy when used as an adjunct or a prior step to CR staining,especially for cases with limited tissues for further analysis.
基金the junior research fellowship from the Council of Scientific and Industrial Research, Government of India
文摘BACKGROUND Histopathologically stained archived tissue slides are stored in hospital archives for years to decades.They are the largest available source of biological materials and are a potentially useful resource that can be used for retrospective epidemiological studies.DNA recovered from the slides can be used for several downstream molecular processes including polymerase chain reaction,single nucleotide polymorphism analysis,and whole genome sequencing.The DNA from these slides can be utilized to compare gene signatures of normal and diseased tissues.However,extraction of high-quality DNA from archived stained hematoxylin and eosin(H&E)slides remains challenging.AIM To standardize a new protocol for extracting DNA from archived H&E-stained tissue slides for further molecular assays.METHODS A total of 100 archived H&E-stained cancer slides were subjected to a total of five methods of DNA extraction.Methods were varied in the deparaffinization step,tissue rehydration,duration of lysis,and presence or absence of proteinase K.The extracted DNA was quantified using a NanoDrop spectrophometer and the quality was analyzed by agarose gel electrophoresis.Then each sample was subjected to polymerase chain reaction(PCR)to amplify the internal control gene GAPDH,thereby confirming the DNA intactness,which could be further utilized for other downstream applications.RESULTS Of the five different methods tested,the third method wherein xylene was used for tissue deparaffinization followed by 72 h of digestion and without proteinase K inactivation yielded the highest amount of DNA with good purity.The yield was significantly higher when compared to other methods.In addition,90%of the extracted DNA showed amplifiable GAPDH gene.CONCLUSION Here we present a step-by-step,cost-effective,and reproducible protocol for the extraction of PCR-friendly DNA from archived H&E-stained cancer tissue slides that can be used for further downstream molecular applications.
文摘Purpose:.To compare the merits and limitations of hematoxylin-eosin(HE) and methyl violet staining for displaying ghost cells from vitreous or aqueous humor.Methods:.A specimen containing ghost cells was adjusted to five different concentrations:(12×104,.10×104,.8×104, 6×104and 4×104cells / ml) and subjected to smearing and methyl violet and HE staining..The staining results were observed by light microscopy.Results: The ghost cells were readily observed at a cell density of > 8×104cells / ml with methyl violet staining,.but only a few cells were occasionally seen at lower cell densities..In contrast,.ghost cells were seen at all cell densities with HE staining.Conclusion: Methyl violet staining is more rapid and simpler for the identification of ghost cells, but its staining color more readily fades, the slides cannot be stored, and it is only effective at a cell density of > 8 ×104cells / ml. In contrast,.HE staining is more time-consuming but it can display cell morphology and distinguish cell components more explicitly and slides can be permanently stored. HE staining has advantages over methyl violet staining in detecting the ghost cells when the concentration is < 8×104cells / ml.
文摘BACKGROUND Tumor-infiltrating lymphocytes(TILs)constitute a prognostic factor in hepatocellular carcinoma(HCC).However,different methods of assessing TILs have various pre-analytical,analytical,and post-analytical challenges.The evaluation of TILs in hematoxylin and eosin(H&E)-stained tumor sections proposed by the International Immuno-Oncology Biomarker Working Group was demonstrated to be a reproducible,affordable and easily applied method in many tumors.AIM To evaluate the prognostic significance of TILs in H&E-stained slides of HCCs.METHODS This was a retrospective study performed in the hospital.HCC patients who underwent liver resection between 2015 and 2017 in Zhongshan Hospital were enrolled in this study.Patients who experienced recurrence or received therapy in addition to antiviral therapy before surgery at this time were excluded.A total of 204 patients were enrolled in the study.The ILs were counted manually in tumor sections stained with H&E under an optical microscope at 400×.The ILs were assessed separately in the center of the tumor(TILs^(CT)),the invasive front(TILs^(IF)),and peritumor(PILs)areas.Univariate and multivariate survival analyses were performed using a Cox regression model.P<0.05 was considered statistically significant and all P-values were two-sided.RESULTS Among the 204 patients,univariate analysis indicated that macrovascular invasion(MaVI)(P=0.001),microvascular invasion(MVI)(P=0.012),multiple tumors(P=0.008),large tumors(>10 cm)(P=0.001),absence of a tumor capsule(P=0.026),macrotrabecular histological subtype(P=0.001),low density of TILs^(CT)(P=0.039),TILs^(IF)(P=0.014),and PILs(P=0.010)were predictors of progressionfree survival(PFS).Cox multivariate analysis indicated that MaVI(P=0.009),absence of a tumor capsule(P=0.031),low-density of TILs^(IF)(P=0.047)and PILs(P=0.0495)were independent predictors of PFS.A three-category analysis was carried out by combining TILs^(CT),TILs^(IF),and PILs,after which HCCs were classified into immune^(high)[(TILs^(CT))^(high),(TILs^(IF))^(high),and PILs^(high),83 cases],immune^(mod)(tumors other than immune^(high) and immune^(low) subtypes,94 cases),and immune^(low)[(TILs^(CT))^(low),(TILs^(IF))^(low),and PILs^(low),27 cases]subtypes.The immune^(high) subtype had a lower rate of MVI(40.96%)than the immune^(mod)(61.70%,P=0.017)and immune^(low)(66.67%,P=0.020)subtypes.The recurrence rates of the immune^(high),immune^(mod) and immune^(low) subtypes were 10.8%,25.5%and 33.3%,respectively.CONCLUSION HCC patients with high infiltrating lymphocytes tend to have a lower recurrence rate and less MVI.The evaluation of TILs in H&E-stained specimens could be a prognostic parameter for HCC.
基金Ministry of Higher Education,Malaysia for Fundamental Research Grant Scheme FRGS/1/2019/SKK06/USM/03/6,No.291983-329281.
文摘BACKGROUND Diabetes is known damage the liver and kidney,leading to hepatic dysfunction and kidney failure.Honey is believed to help in lowering the blood glucose levels of diabetic patients and reducing diabetic complications.However,the effect of stingless bee honey(SBH)administration in relieving liver and kidney damage in diabetes has not been well-studied.AIM To investigate the effect of SBH administration on the kidney and liver of streptozotocin-induced(STZ;55 mg/kg)diabetic Sprague Dawley rats.METHODS The rats were grouped as follows(n=6 per group):non-diabetic(ND),untreated diabetic(UNT),metformin-treated(MET),and SBH+metformin-treated(SBME)groups.After successful diabetic induction,ND and UNT rats were given normal saline,whereas the treatment groups received SBH(2.0 g/kg and/or metformin(250 mg/kg)for 12 d.Serum biochemical parameters and histological changes using hematoxylin and eosin(H&E)and periodic acid–Schiff(PAS)staining were evaluated.RESULTS On H&E and PAS staining,the ND group showed normal architecture and cellularity of Bowman’s capsule and tubules,whereas the UNT and MET groups had an increased glomerular cellularity and thickened basement membrane.The SBH-treated group showed a decrease in hydropic changes and mild cellularity of the glomerulus vs the ND group based on H&E staining,but the two were similar on PAS staining.Likewise,the SBME-treated group had an increase in cellularity of the glomerulus on H&E staining,but it was comparable to the SBH and ND groups on PAS staining.UNT diabetic rats had tubular hydropic tubules,which were smaller than other groups.Reduced fatty vacuole formation and dilated blood sinusoids in liver tissue were seen in the SBH group.Conversely,the UNT group had high glucose levels,which subsequently increased MDA levels,ultimately leading to liver damage.SBH treatment reduced this damage,as evidenced by having the lowest fasting glucose,serum alanine transaminase,aspartate transaminase,and alkaline phosphatase levels compared to other groups,although the levels of liver enzymes were not statistically significant.CONCLUSION The cellularity of the Bowman’s capsule,as well as histological alteration of kidney tubules,glomerular membranes,and liver tissues in diabetic rats after oral SBH resembled those of ND rats.Therefore,SBH exhibited a protective hepatorenal effect in a diabetic rat model.
基金Supported by the Key Program Projects of National Natural Science Foundation of China (20431030)the National Natural Sci-ence Foundation of China (20671032,20676027)the Key Program Projects of Heilongjiang Province Natural Science Foundation of China (ZJG0602 -01)
文摘Removal of dye Eosin on two different samples of activated carbon by static batch method was studied. Experimental data on optical density of blank solutions of different concentrations ranging from 10 to 100 mg/L and optical density of solutions after adsorption on activated carbon samples were taken and analyzed. Calibration curves were plotted and the amount of dye adsorbed was calculated. The data was fitted to Langmuir and Freundlich isotherms for two different carbon samples and different concentration values. Constants were calculated from the slope and intercept values of the isotherms. Coefficient of correlation R2 and Standard Deviation SD were also noted. The data fitted well to the iso- therms. It was observed that adsorption decreased with increase in ppm concentrations. Carbon sample C2 showed higher potential to adsorb the dye Eosin as compared to carbon sample C1. Further Carbon sample C2 showed better adsorption in acidic pH as compared to in alkaline pH. From the analysis of the data it is shown that C2 sample has a good capacity to remove the textile dye from the residue water.
基金the Key Projects of Science and Technology of Education Ministry(00250)the Natural Science Foundation of Gansu Province(3ZS041-A25-028)+1 种基金the Projects of KJCXGC-01,NWNUCansu Key Lab of Polymer Materials,China
文摘This paper describes a novel method for the degradation of eosin by using glow discharge electrolysis （GDE）. The effects of various parameters on the removal efficiency were studied. It was found that the eosin degradation could be raised considerably by increasing the applied voltage and the initial concentration, or by decreasing pH of the aqueous solution. Fe^2＋ ion had an evident accelerating effect on the eosin degradation. The degradation process of eosin obeyed a pseudo-first-order reaction. The relationship between the degradation rate constant k and the reaction temperature T could be expressed by Arrhenius equation with which the apparent activation energy Ea of 14.110 kJ· mol^-1 and the pre-exponential factor k0 of 2.065× 10^-1 min^-1 were obtained, too. The determination of hydroxyl radical was carried out by using N, N-dimethyl -p-nitrosoaniline （RNO） as a scavenger. The results showed that the hydroxyl radical plays an important role in the degradation process.
基金National Natural Science Foundation of China(No.20477030).
文摘The adsorptive precipitation between eosin Y （EY） and AgCl colloids at pH 3.73 caused the sensitive color change of the solution. The reaction mechanism between EY and AgCl was analyzed and this reaction was used for determination of Cl^- in trace level by the light-absorption radio variation approach.
基金Project(8451063201001261) supported by the Guangdong Natural Science Fund Committee,ChinaProject(LYM08022) supported by the Foundation for Distinguished Young Talents in Higher Education of Guangdong,China+1 种基金Project (2007A032400001, 2008A030202010) supported by the Scientific and Technological Planning of Guangdong Province,ChinaProject(216113132) supported by the Scientific Research Cultivation and Innovation Fund, Jinan University,China
文摘The role of oxygen and the generation of active radicals in the photocatalitic degradation of phenol were investigated using the eosin sensitized TiO2 as photocatalyst under visible light irradiation. Diffuse reflectance spectra show that the absorbancy range of eosin/TiO2 is expanded from 378 nm (TiO2 ) to about 600 nm. The photocatalitic degradation of phenol is almost stopped when the eosin/TiO2 system is saturated with N2 , which indicates the significance of O2 . The addition of NaN 3 (a quencher of single oxygen) causes about a 62% decrease in the phenol degradation. The phenol degradation ratio is dropped from 92% to 75% when the isopropanol (a quencher of hydroxyl radical) is present in the system. The experimental results show that there are singlet oxygen and hydroxyl radical generated in the eosin/TiO2 system under visible light irradiation. The changes of absorbancy indicate that the hydrogen peroxide might be produced. Through the analysis and comparison, it is found that the singlet oxygen is the predominant active radical for the degradation of phenol.
