The effects of feed strength, hydraulic residence time (HRT), and operational temperatures on soluble microbial product (SMP) production were investigated, to gain insights into the production mechanism. A carrier...The effects of feed strength, hydraulic residence time (HRT), and operational temperatures on soluble microbial product (SMP) production were investigated, to gain insights into the production mechanism. A carrier anaerobic baffled reactor (CABR) treating dilute wastewater was operated under a wide range of operational conditions, namely, feed strengths of 300-600 mg/L, HRTs of 9- 18 h, and temperatures of 10-28℃. Generally, SMP production increased with increasing feed strength and decreasing temperature. At high temperature (28℃), SMP production increased with decreasing HRT. As the temperature was decreased to 18 and 10℃, the SMP production was at its peak for 12 h HRT. Therefore, temperature could be an important determinant of SMP production along with HRT. A higher SMP to soluble chemical oxygen demand (SCOD) ratio was found at high temperature and long HRT because of complete volatile fatty acid degradation. SMP accounted for 50%-75% of the SCOD in the last chamber of the CABR. As a secondary metabolite, some SMP could be consumed at lower feed strength.展开更多
Both a theoretical and an empirical model were developed for predicting the formation of soluble microbial products (SMP) during drinking water biofiltration. Four pilot-scale biofilters with ceramsite as the medium...Both a theoretical and an empirical model were developed for predicting the formation of soluble microbial products (SMP) during drinking water biofiltration. Four pilot-scale biofilters with ceramsite as the medium were fed with different acetate loadings for the determination of SMP formation. Using numerically simulated and measured parameters, the theoretical model was developed according to the substrate and biomass balance. The results of this model matched the measured data better for higher SMP formation but did not fit well when SMP formation was lower. In order to better simulate the reality and overcome the difficulties of measuring the kinetic parameters, a simpler empirical model was also developed. In this model, SMP formation was expressed as a function of fed organic loadings and the depth of the medium, and a much better fit was obtained.展开更多
Membrane fouling is a major problem in membrane bioreactors(MBRs).In this study,membrane fouling caused by membrane rejection and adsorption was study.Filtration tests indicated that membrane rejected SMP,causing memb...Membrane fouling is a major problem in membrane bioreactors(MBRs).In this study,membrane fouling caused by membrane rejection and adsorption was study.Filtration tests indicated that membrane rejected SMP,causing membrane pore blockage and then forming a gel layer.Batch adsorption experiments showed that adsorption of SMP onto PVDF membrane was a spontaneous physical adsorption process.Meanwhile,the absolute valueΔG of adsorption of SMP onto D3520 was higher than that of adsorption of SMP onto PVDF membrane,so SMP preferentially adsorbed onto D3520 rather than PVDF membrane.Thus,the effect of ARs on reducing the SMP concentration was investigated.It was found that,6 g of D3520 was suitable for adsorption of SMP.This physical adsorption involved external film diffusion,intra-particle diffusion,and surface adsorption.The Redlich–Peterson isotherm model performed best in terms of describing this equilibrium data.The mechanism of membrane fouling mitigation was verified by MBR simulation system.A case study of AR–MBR system was conducted.The results showed that addition of D3520 can effectively alleviate the development of membrane fouling.展开更多
BACKGROUND The established cardiovascular risk factors cannot explain the overall risk of coronary artery disease(CAD),especially in women.Therefore,there is a growing need for the assessment of novel biomarkers to id...BACKGROUND The established cardiovascular risk factors cannot explain the overall risk of coronary artery disease(CAD),especially in women.Therefore,there is a growing need for the assessment of novel biomarkers to identify women at risk.The receptor for advanced glycation end products(RAGE)and its interaction with the advanced glycation end product(AGE)ligand have been associated with atherogenesis.The soluble fraction of RAGE(sRAGE)antagonizes RAGE signaling and exerts an antiatherogenic effect.AIM The study aim was to explore the association between plasma levels of sRAGE and CAD in nondiabetic postmenopausal women.METHODS This case-control study included 110 nondiabetic postmenopausal women who were enrolled in two groups.Group I included 55 angiographically proven CAD subjects with>50%stenosis in at least one of the major coronary arteries and Group II included 55 healthy control women who did not have CAD or had<50%stenosis of the coronary arteries.Stenosis was confirmed by invasive angiography.Plasma sRAGE was determined by an enzyme-linked immunosorbent assay.RESULTS We observed significantly lower plasma sRAGE concentrations in subjects with CAD vs healthy controls(P<0.05).Univariate and multivariate logistic regression analysis also revealed a significant correlation between plasma sRAGE levels and CAD(P=0.01).Multivariate odds ratios for CAD revealed that subjects with sRAGE concentrations below 225 pg/mL(lowest quartile)had a 6-fold increase in CAD prevalence independent of other risk factors.CONCLUSION Our findings indicated that low sRAGE levels were independently associated with CAD in nondiabetic postmenopausal women.Risk assessment of CAD in postmenopausal women can be improved by including sRAGE along with other risk factors.展开更多
Classical Fc receptors (FcRs) mediate the binding to and recognition of the Fc portion of antibodies and play an important role during immune responses in mammals. Although proteins similar to soluble FcRs have been i...Classical Fc receptors (FcRs) mediate the binding to and recognition of the Fc portion of antibodies and play an important role during immune responses in mammals. Although proteins similar to soluble FcRs have been identified in fish, little is known about the role of such proteins in fish immunity. Here, we cloned a cDNA sequence encoding a soluble Fc receptor for an immunoglobulin G (FcγR) homolog from ayu (Plecoglossus altivelis)(PaFcγRl). The predicted protein was composed of two immunoglobulin C2-like domains but lacked a transmembrane segment and a cytoplasmic tail. The PaFcγRl transcripts were distributed at low levels in all tested tissues, but significantly increased after Vibrio anguillarum infection. The PaFcγRl protein was expressed in the head kidney, trunk kidney, and neutrophils. Recombinant PaFcγRl (rPaFcγRl) was secreted when transfected into mammalian cells and the native protein was also detected in serum upon infection. rPaFcγRl was also demonstrated to bind to ayu IgM, as assessed by cell transfection. Suppressive activity of the recombinant mature protein of PaFcγRl (rPaFcγRlm) on in vitro anti-sheep red blood cell (SRBC) responses was detected by a modified hemolytic plaque forming cell assay. In conclusion, our study revealed that PaFcγRl is closely involved in the negative regulation of IgM production in the ayu spleen.展开更多
Soluble receptor for advanced glycation end products(sRAGE)acts as a decoy sequestering of RAGE ligands,thus preventing the activation of the ligand-RAGE axis linking human diseases.However,the molecular mechanisms un...Soluble receptor for advanced glycation end products(sRAGE)acts as a decoy sequestering of RAGE ligands,thus preventing the activation of the ligand-RAGE axis linking human diseases.However,the molecular mechanisms underlying sRAGE remain unclear.In this study,THP-1 monocytes were cultured in normal glucose(NG,5.5 mmol/L)and high glucose(HG,15 mmol/L)to investigate the effects of diabetesrelevant glucose concentrations on sRAGE and interleukin-1β(IL-1β)secretion.The modulatory effects of epigallocatechin gallate(EGCG)in response to HG challenge were also evaluated.HG enhanced intracellular reactive oxygen species(ROS)generation and RAGE expression.The secretion of sRAGE,including esRAGE and cRAGE,was reduced under HG conditions,together with the downregulation of a disintegrin and metallopeptidase 10(ADAM10)and nuclear factor erythroid 2-related factor 2(Nrf2)nuclear translocation.Mechanistically,the HG effects were counteracted by siRAGE and exacerbated by siNrf2.Chromatin immunoprecipitation results showed that Nrf2 binding to the ADAM10 promoter and HG interfered with this binding.Our data reinforce the notion that RAGE and Nrf2 might be sRAGE-regulating factors.Under HG conditions,the treatment of EGCG reduced ROS generation and RAGE activation.EGCG-stimulated cRAGE release was likely caused by the upregulation of the Nrf2-ADAM10 pathway.EGCG inhibited HG-mediated NLRP3 inflammasome activation at least partly by stimulating sRAGE,thereby reducing IL-1βrelease.展开更多
Soluble receptor for advanced glycation end products(s RAGE) can decoy the toxic AGEs and is considered to be a protective factor.This study aimed to evaluate the correlation between intrafollicular s RAGE levels an...Soluble receptor for advanced glycation end products(s RAGE) can decoy the toxic AGEs and is considered to be a protective factor.This study aimed to evaluate the correlation between intrafollicular s RAGE levels and clinical outcomes in infertile women of young or advanced maternal age(AMA) undergoing in vitro fertilization(IVF).A total of 62 young women and 62 AMA women who would undergo IVF were included in this prospective study.The intrafollicular s RAGE concentration was measured to determine its association with the number of retrieved oocytes,fertilized oocytes,high-quality embryos or achievement of clinical pregnancy in young and AMA women,respectively.Besides,correlations between sR AGE and age or follicle-stimulating hormone(FSH) were examined.We found that the intrafollicular s RAGE levels were higher in young patients than those in AMA patients,suggesting that the s RAGE levels were inversely correlated with age.In young patients,sR AGE showed no correlation with the number of retrieved oocytes,fertilized oocytes,high-quality embryos or achievement of clinical pregnancy.But it was found that AMA patients with more retrieved oocytes,fertilized oocytes and high-quality embryos demonstrated higher sR AGE levels,which were a prognostic factor for getting clinical pregnancy independent of age or FSH level.In conclusion,the s RAGE levels decrease with age.Elevated intrafollicular s RAGE levels indicate good follicular growth,fertilization and embryonic development,and successful clinical pregnancy in AMA women,while in young women,the role of s RAGE may not be so predominant.展开更多
With‘Victoria'grape as a material,the effects of increasing 1200 mg/L of CO_2 on yield,soluble solid content and downy mildew of grape were studied in greenhouse.The results showed that when CO_2 was increased at...With‘Victoria'grape as a material,the effects of increasing 1200 mg/L of CO_2 on yield,soluble solid content and downy mildew of grape were studied in greenhouse.The results showed that when CO_2 was increased at a rate of 1200 mg/L in greenhouse,‘Victoria'fruit was harvested 8 d in advance,and compared with no increase of CO_2,the transverse diameter,longitudinal diameter,average single grain weight,commodity fruit yield at early stage and total yield of commodity fruit increased by 35.07%,7.37%,17.39%,24.88%,46.14% and 20.61%,respectively,with very significant differences.The incidence and disease index of grape downy mildew decreased by more than 50%,indicating a significant control effect.Therefore,increasing CO_2 in greenhouse could bring forward grape harvest,significantly improve yield and soluble solids content of grape and reduce the incidence of grape downy mildew.展开更多
Soluble microbial products(SMPs),dissolved organic matter excreted by activated sludge,can interact with antibiotics in wastewater and natural water bodies.Interactions between SMPs and antibiotics can influence antib...Soluble microbial products(SMPs),dissolved organic matter excreted by activated sludge,can interact with antibiotics in wastewater and natural water bodies.Interactions between SMPs and antibiotics can influence antibiotic migration,transformation,and toxicity but the mechanisms involved in such interactions are not fully understood.In this study,integrated spectroscopy approaches were used to investigate the mechanisms involved in interactions between SMPs and a representative antibiotic,trimethoprim(TMP),which has a low biodegradation rate and has been detected in wastewater.The results of liquid chromatography-organic carbon detection-organic nitrogen detection indicated that the SMPs used in the study contained 15% biopolymers and 28% humic-like substances(based on the total dissolved organic carbon concentration)so would have contained sites that could interact with TMP.A linear relationship of fluorescent intensities of tryptophan protein-like substances in SMP was observed(R^(2)>0.99),indicating that the fluorescence enhancement between SMP and TMP occurred.Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy indicated that carboxyl,carbonyl,and hydroxyl groups were the main functional groups involved in the interactions.The electrostatic andπ-πinteractions were discovered by the UV-vis spectra and 1H nuclear magnetic resonance spectra.Structural representations of the interactions between representative SMP subcomponents and TMP were calculated using density functional theory,and the results confirmed the conclusions drawn from the 1H nuclear magnetic resonance spectra.The results help characterize SMP–TMP complexes and will help understand antibiotic transformations in wastewater treatment plants and aquatic environments.展开更多
目的基于荧光法快速简便地鉴别巴氏杀菌乳和超高温(ultra high temperature,UHT)灭菌乳。方法基于美拉德产物荧光值的不同,采用直接荧光法结合综合热损伤(fluorescence of advanced Maillard products and soluble tryptophan,FAST)指...目的基于荧光法快速简便地鉴别巴氏杀菌乳和超高温(ultra high temperature,UHT)灭菌乳。方法基于美拉德产物荧光值的不同,采用直接荧光法结合综合热损伤(fluorescence of advanced Maillard products and soluble tryptophan,FAST)指数快速鉴定巴氏杀菌乳和UHT灭菌乳。结果巴氏杀菌乳和UHT灭菌乳由于热处理强度不同,二者的荧光值存在显著差异(P<0.01),巴氏杀菌乳荧光值在(13215±236)~(15359±156)之间、UHT灭菌乳荧光值范围为(15788±200)~(20440±270)。与巴氏杀菌乳相比,UHT灭菌乳直接测定荧光强度和FAST指数明显升高且差异显著(P<0.01)。在商品巴氏杀菌乳和UHT灭菌乳结果的基础上,利用自制产品对荧光法进行了验证。结论直接荧光测定法和FAST指数能够快速有效区分和识别巴氏杀菌乳和UHT灭菌乳,该技术对产品热处理强度评价及质量监管具有一定指导意义。展开更多
文摘The effects of feed strength, hydraulic residence time (HRT), and operational temperatures on soluble microbial product (SMP) production were investigated, to gain insights into the production mechanism. A carrier anaerobic baffled reactor (CABR) treating dilute wastewater was operated under a wide range of operational conditions, namely, feed strengths of 300-600 mg/L, HRTs of 9- 18 h, and temperatures of 10-28℃. Generally, SMP production increased with increasing feed strength and decreasing temperature. At high temperature (28℃), SMP production increased with decreasing HRT. As the temperature was decreased to 18 and 10℃, the SMP production was at its peak for 12 h HRT. Therefore, temperature could be an important determinant of SMP production along with HRT. A higher SMP to soluble chemical oxygen demand (SCOD) ratio was found at high temperature and long HRT because of complete volatile fatty acid degradation. SMP accounted for 50%-75% of the SCOD in the last chamber of the CABR. As a secondary metabolite, some SMP could be consumed at lower feed strength.
基金supported by the National Natural Science Foundation of China (Grant No. 50408026)
文摘Both a theoretical and an empirical model were developed for predicting the formation of soluble microbial products (SMP) during drinking water biofiltration. Four pilot-scale biofilters with ceramsite as the medium were fed with different acetate loadings for the determination of SMP formation. Using numerically simulated and measured parameters, the theoretical model was developed according to the substrate and biomass balance. The results of this model matched the measured data better for higher SMP formation but did not fit well when SMP formation was lower. In order to better simulate the reality and overcome the difficulties of measuring the kinetic parameters, a simpler empirical model was also developed. In this model, SMP formation was expressed as a function of fed organic loadings and the depth of the medium, and a much better fit was obtained.
基金financially supported by the Inner Mongolia Natural Science Foundation of China(No.2016BS0205)the Scientific Research Foundation of the Inner Mongolia University of Technology of China(No.ZD201505).
文摘Membrane fouling is a major problem in membrane bioreactors(MBRs).In this study,membrane fouling caused by membrane rejection and adsorption was study.Filtration tests indicated that membrane rejected SMP,causing membrane pore blockage and then forming a gel layer.Batch adsorption experiments showed that adsorption of SMP onto PVDF membrane was a spontaneous physical adsorption process.Meanwhile,the absolute valueΔG of adsorption of SMP onto D3520 was higher than that of adsorption of SMP onto PVDF membrane,so SMP preferentially adsorbed onto D3520 rather than PVDF membrane.Thus,the effect of ARs on reducing the SMP concentration was investigated.It was found that,6 g of D3520 was suitable for adsorption of SMP.This physical adsorption involved external film diffusion,intra-particle diffusion,and surface adsorption.The Redlich–Peterson isotherm model performed best in terms of describing this equilibrium data.The mechanism of membrane fouling mitigation was verified by MBR simulation system.A case study of AR–MBR system was conducted.The results showed that addition of D3520 can effectively alleviate the development of membrane fouling.
文摘BACKGROUND The established cardiovascular risk factors cannot explain the overall risk of coronary artery disease(CAD),especially in women.Therefore,there is a growing need for the assessment of novel biomarkers to identify women at risk.The receptor for advanced glycation end products(RAGE)and its interaction with the advanced glycation end product(AGE)ligand have been associated with atherogenesis.The soluble fraction of RAGE(sRAGE)antagonizes RAGE signaling and exerts an antiatherogenic effect.AIM The study aim was to explore the association between plasma levels of sRAGE and CAD in nondiabetic postmenopausal women.METHODS This case-control study included 110 nondiabetic postmenopausal women who were enrolled in two groups.Group I included 55 angiographically proven CAD subjects with>50%stenosis in at least one of the major coronary arteries and Group II included 55 healthy control women who did not have CAD or had<50%stenosis of the coronary arteries.Stenosis was confirmed by invasive angiography.Plasma sRAGE was determined by an enzyme-linked immunosorbent assay.RESULTS We observed significantly lower plasma sRAGE concentrations in subjects with CAD vs healthy controls(P<0.05).Univariate and multivariate logistic regression analysis also revealed a significant correlation between plasma sRAGE levels and CAD(P=0.01).Multivariate odds ratios for CAD revealed that subjects with sRAGE concentrations below 225 pg/mL(lowest quartile)had a 6-fold increase in CAD prevalence independent of other risk factors.CONCLUSION Our findings indicated that low sRAGE levels were independently associated with CAD in nondiabetic postmenopausal women.Risk assessment of CAD in postmenopausal women can be improved by including sRAGE along with other risk factors.
基金supported by the Program for the National Natural Science Foundation of China(3177287631402323+6 种基金31372555)Natural Science Foundation of Zhejiang Province(LZ18C190001LY14C190007)Scientific Innovation Team Project of Ningbo(2015C110018)Natural Science Foundation of Ningbo City of China(2018A610225)Ningbo Science and Technology “Fumin Engineering”Project(2017C10037)K.C.Wong Magna Fund in Ningbo University
文摘Classical Fc receptors (FcRs) mediate the binding to and recognition of the Fc portion of antibodies and play an important role during immune responses in mammals. Although proteins similar to soluble FcRs have been identified in fish, little is known about the role of such proteins in fish immunity. Here, we cloned a cDNA sequence encoding a soluble Fc receptor for an immunoglobulin G (FcγR) homolog from ayu (Plecoglossus altivelis)(PaFcγRl). The predicted protein was composed of two immunoglobulin C2-like domains but lacked a transmembrane segment and a cytoplasmic tail. The PaFcγRl transcripts were distributed at low levels in all tested tissues, but significantly increased after Vibrio anguillarum infection. The PaFcγRl protein was expressed in the head kidney, trunk kidney, and neutrophils. Recombinant PaFcγRl (rPaFcγRl) was secreted when transfected into mammalian cells and the native protein was also detected in serum upon infection. rPaFcγRl was also demonstrated to bind to ayu IgM, as assessed by cell transfection. Suppressive activity of the recombinant mature protein of PaFcγRl (rPaFcγRlm) on in vitro anti-sheep red blood cell (SRBC) responses was detected by a modified hemolytic plaque forming cell assay. In conclusion, our study revealed that PaFcγRl is closely involved in the negative regulation of IgM production in the ayu spleen.
文摘Soluble receptor for advanced glycation end products(sRAGE)acts as a decoy sequestering of RAGE ligands,thus preventing the activation of the ligand-RAGE axis linking human diseases.However,the molecular mechanisms underlying sRAGE remain unclear.In this study,THP-1 monocytes were cultured in normal glucose(NG,5.5 mmol/L)and high glucose(HG,15 mmol/L)to investigate the effects of diabetesrelevant glucose concentrations on sRAGE and interleukin-1β(IL-1β)secretion.The modulatory effects of epigallocatechin gallate(EGCG)in response to HG challenge were also evaluated.HG enhanced intracellular reactive oxygen species(ROS)generation and RAGE expression.The secretion of sRAGE,including esRAGE and cRAGE,was reduced under HG conditions,together with the downregulation of a disintegrin and metallopeptidase 10(ADAM10)and nuclear factor erythroid 2-related factor 2(Nrf2)nuclear translocation.Mechanistically,the HG effects were counteracted by siRAGE and exacerbated by siNrf2.Chromatin immunoprecipitation results showed that Nrf2 binding to the ADAM10 promoter and HG interfered with this binding.Our data reinforce the notion that RAGE and Nrf2 might be sRAGE-regulating factors.Under HG conditions,the treatment of EGCG reduced ROS generation and RAGE activation.EGCG-stimulated cRAGE release was likely caused by the upregulation of the Nrf2-ADAM10 pathway.EGCG inhibited HG-mediated NLRP3 inflammasome activation at least partly by stimulating sRAGE,thereby reducing IL-1βrelease.
基金supported by the National Natural Science Foundation of China(No.81471507)
文摘Soluble receptor for advanced glycation end products(s RAGE) can decoy the toxic AGEs and is considered to be a protective factor.This study aimed to evaluate the correlation between intrafollicular s RAGE levels and clinical outcomes in infertile women of young or advanced maternal age(AMA) undergoing in vitro fertilization(IVF).A total of 62 young women and 62 AMA women who would undergo IVF were included in this prospective study.The intrafollicular s RAGE concentration was measured to determine its association with the number of retrieved oocytes,fertilized oocytes,high-quality embryos or achievement of clinical pregnancy in young and AMA women,respectively.Besides,correlations between sR AGE and age or follicle-stimulating hormone(FSH) were examined.We found that the intrafollicular s RAGE levels were higher in young patients than those in AMA patients,suggesting that the s RAGE levels were inversely correlated with age.In young patients,sR AGE showed no correlation with the number of retrieved oocytes,fertilized oocytes,high-quality embryos or achievement of clinical pregnancy.But it was found that AMA patients with more retrieved oocytes,fertilized oocytes and high-quality embryos demonstrated higher sR AGE levels,which were a prognostic factor for getting clinical pregnancy independent of age or FSH level.In conclusion,the s RAGE levels decrease with age.Elevated intrafollicular s RAGE levels indicate good follicular growth,fertilization and embryonic development,and successful clinical pregnancy in AMA women,while in young women,the role of s RAGE may not be so predominant.
基金Supported by Major Special Project of The Inner Mongolia Autonomous Region Science and Technology Agency(201602061)
文摘With‘Victoria'grape as a material,the effects of increasing 1200 mg/L of CO_2 on yield,soluble solid content and downy mildew of grape were studied in greenhouse.The results showed that when CO_2 was increased at a rate of 1200 mg/L in greenhouse,‘Victoria'fruit was harvested 8 d in advance,and compared with no increase of CO_2,the transverse diameter,longitudinal diameter,average single grain weight,commodity fruit yield at early stage and total yield of commodity fruit increased by 35.07%,7.37%,17.39%,24.88%,46.14% and 20.61%,respectively,with very significant differences.The incidence and disease index of grape downy mildew decreased by more than 50%,indicating a significant control effect.Therefore,increasing CO_2 in greenhouse could bring forward grape harvest,significantly improve yield and soluble solids content of grape and reduce the incidence of grape downy mildew.
基金supported by the National Natural Science Foundation of China (Nos. 51878244 and 52170032)the the Fundamental Research Funds for the Central Universities (No. B200202101)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), China
文摘Soluble microbial products(SMPs),dissolved organic matter excreted by activated sludge,can interact with antibiotics in wastewater and natural water bodies.Interactions between SMPs and antibiotics can influence antibiotic migration,transformation,and toxicity but the mechanisms involved in such interactions are not fully understood.In this study,integrated spectroscopy approaches were used to investigate the mechanisms involved in interactions between SMPs and a representative antibiotic,trimethoprim(TMP),which has a low biodegradation rate and has been detected in wastewater.The results of liquid chromatography-organic carbon detection-organic nitrogen detection indicated that the SMPs used in the study contained 15% biopolymers and 28% humic-like substances(based on the total dissolved organic carbon concentration)so would have contained sites that could interact with TMP.A linear relationship of fluorescent intensities of tryptophan protein-like substances in SMP was observed(R^(2)>0.99),indicating that the fluorescence enhancement between SMP and TMP occurred.Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy indicated that carboxyl,carbonyl,and hydroxyl groups were the main functional groups involved in the interactions.The electrostatic andπ-πinteractions were discovered by the UV-vis spectra and 1H nuclear magnetic resonance spectra.Structural representations of the interactions between representative SMP subcomponents and TMP were calculated using density functional theory,and the results confirmed the conclusions drawn from the 1H nuclear magnetic resonance spectra.The results help characterize SMP–TMP complexes and will help understand antibiotic transformations in wastewater treatment plants and aquatic environments.
文摘目的基于荧光法快速简便地鉴别巴氏杀菌乳和超高温(ultra high temperature,UHT)灭菌乳。方法基于美拉德产物荧光值的不同,采用直接荧光法结合综合热损伤(fluorescence of advanced Maillard products and soluble tryptophan,FAST)指数快速鉴定巴氏杀菌乳和UHT灭菌乳。结果巴氏杀菌乳和UHT灭菌乳由于热处理强度不同,二者的荧光值存在显著差异(P<0.01),巴氏杀菌乳荧光值在(13215±236)~(15359±156)之间、UHT灭菌乳荧光值范围为(15788±200)~(20440±270)。与巴氏杀菌乳相比,UHT灭菌乳直接测定荧光强度和FAST指数明显升高且差异显著(P<0.01)。在商品巴氏杀菌乳和UHT灭菌乳结果的基础上,利用自制产品对荧光法进行了验证。结论直接荧光测定法和FAST指数能够快速有效区分和识别巴氏杀菌乳和UHT灭菌乳,该技术对产品热处理强度评价及质量监管具有一定指导意义。