UiO-66 is a zirconium-based metal-organic framework(MOF)that has numerous applications.Our group recently determined that UiO-66 is not as inert in aqueous dispersions as previously reported in the literature.The pres...UiO-66 is a zirconium-based metal-organic framework(MOF)that has numerous applications.Our group recently determined that UiO-66 is not as inert in aqueous dispersions as previously reported in the literature.The present work therefore assessed the behaviour of UiO-66 in buffers:2-amino-2-(hydroxymethyl)-1,3-propanediol(TRIS),4-(2-hydroxyethyl)piperazine-1-ethane sulfonic acid(HEPES),N-ethylmorpholine(NEM)and phosphate buffer(PB),all of which are commonly used in many UiO-66 applications.High performance liquid chromatography and inductively coupled plasma mass spec trometry were used to monitor degradation of the MOF at 25℃.In each buffer,the terephthalate linker was released to some extent.The chemical nature of the buffer media played a decisive role in the stabi lity with a more pronounced leaching effect in the saline forms of these buffers.The HEPES buffer was found to be the most benign,whereas NEM and PB should be avoided at any concentration as they were shown to rapidly degrade the UiO-66 framework.Low concentration TRIS buffers are also recommended,although these offer minimal buffer capacity to adjust pH.Regardless of the buffer used,rapid tere phthalate release was observed,indicating that the UiO-66 was attacked immediately after mixing with the buffer.This process was even more pronounced at 37℃,i.e.,at typical temperature in biological and medical applications.In addition,the dissolution of zirconium,observed in some cases,intensified the UiO-66 decomposition process.These results demonstrate that sensitive analytical techniques have to be used to monitor the release of MOF components so as to quantify the stabilities of these materials in liquid environments.展开更多
Bioavailability is a critical factor for assessing the environmental risk of organic pollutants in soil. In this study, extractions with 3 different solvents, including 2 aqueous solutions, calcium chloride(CaCl_2) an...Bioavailability is a critical factor for assessing the environmental risk of organic pollutants in soil. In this study, extractions with 3 different solvents, including 2 aqueous solutions, calcium chloride(CaCl_2) and a phosphate buffer solution(PBS), and a mixture of aqueous solution and organic solvent, a PBS-methanol(8:2,volume/volume) mixture(PBS-M), were performed to assess the bioavailability of chlorimuron-ethyl in soil in comparison to a battery of toxicity tests in wheat seedlings. The results indicated that the peroxidase(POD) activity in wheat leaves after 7 d of exposure was one of the sensitive biomarkers of chlorimuron-ethyl in soil.The extractability of chlorimuron-ethyl by all the 3 solvents decreased with exposure time, and the rate of decrease of the PBS-M extraction between 1 and 7 d of exposure was substantially higher than those of the aqueous solution extractions. Chlorimuron-ethyl gradually changed from a water-soluble form into a soil organic matter(SOM)-bound form in the soil. The PBS extraction correlated best with the POD activity in the leaves after 7 d of exposure.展开更多
Propolis is a resinous natural product,produced by bees(Apis mellifera),from vegetable parts and plant secretions.Propolis’samples A,B,C and D were extracted with phosphate buffer saline(PBS)or with 70%EtOH at pH val...Propolis is a resinous natural product,produced by bees(Apis mellifera),from vegetable parts and plant secretions.Propolis’samples A,B,C and D were extracted with phosphate buffer saline(PBS)or with 70%EtOH at pH values 8.0,7.2 and 6.4 followed by:(1)reverse-phase high-performance liquid chromatography(RP-HPLC)on Purospher®Star RP-18 column,the quantity of caffeic acid,chrysin,pinocembrin and galangin was determined;(2)determination of total flavonoids in both extracts;(3)antimicrobial tests of both extracts against(a)Gram-positive bacteria:methicillin-resistant Staphylococcus aureus(MRSA),St.aureus,Streptococcus pyogenes,Str.agalactiae,(b)Gram-negative bacteria:Escherichia coli,Pseudomonas aeruginosa,Proteus mirabilis,Acinetobacter baumanii and(c)yeast:Candida albicans.The antimicrobial activity of propolis’PBS extracts against Gram-positive bacteria shows the lowest minimal inhibitory concentration(MIC,mg/mL)at pH 8.0 in sample C,followed by A,B and D.In sample C,MICs at pH 8.0 were 0.007(Str.agalactiae),0.015(MRSA),0.015(Str.pyogenes)and 0.007(St.aureus).The polyphenol content of sample C is:flavonoid content 5.47±0.62 mg/mL,caffeic acid 1.33±0.92 mg/mL,chrysin 41.02±4.22μg/mL,pinocembrin 2.93±0.33 mg/mL and galangin 41.87±4.23 mg/mL.PBS extracts against Gram-negative bacteria show the lowest MIC(mg/mL)at pH 8.0 in sample D,followed by B,C and A.In sample D,MICs at pH 8.0 were 0.003(Acin.baumanii,Pr.mirabilis,Ps.aeruginosa)and 0.007(E.coli).Polyphenol content of sample D is:flavonoids 8.28±0.92 mg/mL,caffeic acid 3.56±0.32 mg/mL,chrysin 677.42±68.42μg/mL,pinocembrin 146.49±13.89 mg/mL and galangin 59.81±5.86 mg/mL.The strongest anti C.albicans activity,with the lowest MIC(mg/mL),at pH 8.0 was in the sample C,followed by samples D,A and B.In sample C,the MIC at pH 8.0 is 0.001(PBS extract).The antimicrobial activities of selected propolis samples correlate with their polyphenol content,more precisely,flavonoid,caffeic acid,chrysin,pinocembrin and galangin content.展开更多
The effects ofpH, dissolved ion content and relative water velocity on the release rate of an antifouling agent, cuprous oxide, from ships＇ hull paint have been investigated by rotating cylinder tests. Additionally, ...The effects ofpH, dissolved ion content and relative water velocity on the release rate of an antifouling agent, cuprous oxide, from ships＇ hull paint have been investigated by rotating cylinder tests. Additionally, test paint panels were attached to a vessel and recovered after a certain period of voyage for the validation of the laboratory tests. In the initial period, the release rates are influenced by pH, dissolved ion content and water velocity, but once after a certain period of test, those effects become less significant. These phenomena can be explained when the paint film is fresh, the rate is controlled by chemical reaction, the surface and/or diffusion layer in the water phase governs the rate. After the antifouling substance in the paint film leached out from the near-surface region, a diffused layer （leached layer）, that has little antifouling agent remained, is formed at the surface of the coating, and the diffusion in that layer can be a rate-determining process. The development of the leached layer is affected by a balance between the leaching rate of the antifouling ingredient and paint resin determined by the chemical properties and speed of the water. Thus, the leaching rates of antifouling agents are affected by the history of the paint in the water.展开更多
Objective:We conducted a comprehensive physicochemical analysis of one-dimensional ZnO nanowires(1DZnO),incorporating anti-CYFRA 21-1 immobilization to promote fast optical biomarker detection up to 10 ng ml−1.Impact ...Objective:We conducted a comprehensive physicochemical analysis of one-dimensional ZnO nanowires(1DZnO),incorporating anti-CYFRA 21-1 immobilization to promote fast optical biomarker detection up to 10 ng ml−1.Impact Statement:This study highlights the effectiveness of proof-of-concept 1DZnO nanoplatforms for rapid cancer biomarker detection by examining the nanoscale integration of 1DZnO with these bioreceptors to deliver reliable photoluminescent output signals.Introduction:The urgent need for swift and accurate prognoses in healthcare settings drives the rise of sensitive biosensing nanoplatforms for cancer detection,which has benefited from biomarker identification.CYFRA 21-1 is a reliable target for the early prediction of cancer formation that can be perceptible in blood,saliva,and serum.However,1DZnO nanostructures have been barely applied for CYFRA 21-1 detection.Methods:We assessed the nanoscale interaction between 1DZnO and anti-CYFRA 21-1 antibodies to develop rapid CYFRA 21-1 detection in two distinct matrices:PhosphateBuffered Saline(PBS)buffer and artificial saliva.The chemical modifications were tracked utilizing Fourier transform infrared spectroscopy,while transmission electron microscopy and energy dispersive spectroscopy confirmed antigen-antibody interplay over nanostructures.Results:Our results show high antibody immobilization efficiencies,affirming the effectiveness of 1DZnO nanoplatforms for rapid CYFRA 21-1 testing within a 5-min detection window in both PBS and artificial saliva.Photoluminescence measurements also revealed distinct optical responses across biomarker concentrations ranging from 10 to 1,000 ng ml^(−1).Conclusion:Discernible PL signal responses obtained after 5 min affirm the potential of 1DZnO nanoplatforms for further advancement in optical biomarker detection for application in early cancer prognosis.展开更多
The electrochemical behaviour of three duplex stainless steels,(SAF 2101,SAF 2304,SAF 2205)was investigated.Open circuit potential,EOC,measurements,and electrochemical impedance spectroscopy(EIS)were employed both in ...The electrochemical behaviour of three duplex stainless steels,(SAF 2101,SAF 2304,SAF 2205)was investigated.Open circuit potential,EOC,measurements,and electrochemical impedance spectroscopy(EIS)were employed both in phosphate-buffered saline solution(PBS,pH=7.2)and in PBS simulating in vitro inflammatory conditions(PBS+H2O2,pH=5.0).It has been established that the tendency of the investigated steel materials towards corrosion de-creases in the following order:SAF 2101<SAF 2304<SAF 2205 in both ag-gressive environments.The superior corrosion resistance exhibited by SAF 2205 is ascribed to the formation of a passive film with enhanced protective effectiveness than the one formed on SAF 2101 and SAF 2304,and this im-provement is ascribed to a synergistic effect of Mo+N owing to the high mo-lybdenum content in the alloy.展开更多
This study investigates the targeted imaging and tumor inhibition effects of a"signal-off"imaging-based activatable aptamer probe(I-AAP)for pancreatic cancer.AS1411,contained in the I-AAP probe,targets the n...This study investigates the targeted imaging and tumor inhibition effects of a"signal-off"imaging-based activatable aptamer probe(I-AAP)for pancreatic cancer.AS1411,contained in the I-AAP probe,targets the nucleolin and i-motifs on the membrane surfaces of pancreatic cancer cells(PANC-1)and has a dual response to pH and an acidic environment.In vitro,a"signal-off"type I-AAP probe was constructed that possesses a fluorescence effect in a phosphate buffer solution at pH 6.0 and 6.5.The probe has no fluorescence effect at pH 7.0 or 7.5;thus,the"signal-off"type I-AAP probe has a targeted acid-sensitive response in pancreatic cancer and a tumor microenvironment imaging effect.After incubation for 30 min,AS1411 was taken up by PANC-1 cells and reached its peak value within 2 h.AS1411 inhibited pancreatic cancer cells in a time-dependent manner.This"signal-off"I-AAP probe is expected to be suitable for a low-background and high-specificity molecular pathologic tracer technique,making use of the presence of nucleolins on the surface of pancreatic cancer cells and the low pH response of the tumor microenvironment.展开更多
基金the National Natural Science Foundation of China，the Fundamental Research Funds for the Central Universities，the Key Research Program of Chinese Academy of Sciences
基金supported by the Czech Science Foundation(No.20-04408S).the Ministry of Education,Youth and Sports of the Czech Republic under Project No.LM2018124.
文摘UiO-66 is a zirconium-based metal-organic framework(MOF)that has numerous applications.Our group recently determined that UiO-66 is not as inert in aqueous dispersions as previously reported in the literature.The present work therefore assessed the behaviour of UiO-66 in buffers:2-amino-2-(hydroxymethyl)-1,3-propanediol(TRIS),4-(2-hydroxyethyl)piperazine-1-ethane sulfonic acid(HEPES),N-ethylmorpholine(NEM)and phosphate buffer(PB),all of which are commonly used in many UiO-66 applications.High performance liquid chromatography and inductively coupled plasma mass spec trometry were used to monitor degradation of the MOF at 25℃.In each buffer,the terephthalate linker was released to some extent.The chemical nature of the buffer media played a decisive role in the stabi lity with a more pronounced leaching effect in the saline forms of these buffers.The HEPES buffer was found to be the most benign,whereas NEM and PB should be avoided at any concentration as they were shown to rapidly degrade the UiO-66 framework.Low concentration TRIS buffers are also recommended,although these offer minimal buffer capacity to adjust pH.Regardless of the buffer used,rapid tere phthalate release was observed,indicating that the UiO-66 was attacked immediately after mixing with the buffer.This process was even more pronounced at 37℃,i.e.,at typical temperature in biological and medical applications.In addition,the dissolution of zirconium,observed in some cases,intensified the UiO-66 decomposition process.These results demonstrate that sensitive analytical techniques have to be used to monitor the release of MOF components so as to quantify the stabilities of these materials in liquid environments.
基金supported by the National Natural Science Foundation of China(Nos.41401565,41201520 and 20807046)
文摘Bioavailability is a critical factor for assessing the environmental risk of organic pollutants in soil. In this study, extractions with 3 different solvents, including 2 aqueous solutions, calcium chloride(CaCl_2) and a phosphate buffer solution(PBS), and a mixture of aqueous solution and organic solvent, a PBS-methanol(8:2,volume/volume) mixture(PBS-M), were performed to assess the bioavailability of chlorimuron-ethyl in soil in comparison to a battery of toxicity tests in wheat seedlings. The results indicated that the peroxidase(POD) activity in wheat leaves after 7 d of exposure was one of the sensitive biomarkers of chlorimuron-ethyl in soil.The extractability of chlorimuron-ethyl by all the 3 solvents decreased with exposure time, and the rate of decrease of the PBS-M extraction between 1 and 7 d of exposure was substantially higher than those of the aqueous solution extractions. Chlorimuron-ethyl gradually changed from a water-soluble form into a soil organic matter(SOM)-bound form in the soil. The PBS extraction correlated best with the POD activity in the leaves after 7 d of exposure.
基金the frame of Croatian Institute for Experimental and Translational Oncology(CIETO)supported by IvanČermak from the Crodux-plin,Savska Opatovina,10000 Zagreb,Croatia。
文摘Propolis is a resinous natural product,produced by bees(Apis mellifera),from vegetable parts and plant secretions.Propolis’samples A,B,C and D were extracted with phosphate buffer saline(PBS)or with 70%EtOH at pH values 8.0,7.2 and 6.4 followed by:(1)reverse-phase high-performance liquid chromatography(RP-HPLC)on Purospher®Star RP-18 column,the quantity of caffeic acid,chrysin,pinocembrin and galangin was determined;(2)determination of total flavonoids in both extracts;(3)antimicrobial tests of both extracts against(a)Gram-positive bacteria:methicillin-resistant Staphylococcus aureus(MRSA),St.aureus,Streptococcus pyogenes,Str.agalactiae,(b)Gram-negative bacteria:Escherichia coli,Pseudomonas aeruginosa,Proteus mirabilis,Acinetobacter baumanii and(c)yeast:Candida albicans.The antimicrobial activity of propolis’PBS extracts against Gram-positive bacteria shows the lowest minimal inhibitory concentration(MIC,mg/mL)at pH 8.0 in sample C,followed by A,B and D.In sample C,MICs at pH 8.0 were 0.007(Str.agalactiae),0.015(MRSA),0.015(Str.pyogenes)and 0.007(St.aureus).The polyphenol content of sample C is:flavonoid content 5.47±0.62 mg/mL,caffeic acid 1.33±0.92 mg/mL,chrysin 41.02±4.22μg/mL,pinocembrin 2.93±0.33 mg/mL and galangin 41.87±4.23 mg/mL.PBS extracts against Gram-negative bacteria show the lowest MIC(mg/mL)at pH 8.0 in sample D,followed by B,C and A.In sample D,MICs at pH 8.0 were 0.003(Acin.baumanii,Pr.mirabilis,Ps.aeruginosa)and 0.007(E.coli).Polyphenol content of sample D is:flavonoids 8.28±0.92 mg/mL,caffeic acid 3.56±0.32 mg/mL,chrysin 677.42±68.42μg/mL,pinocembrin 146.49±13.89 mg/mL and galangin 59.81±5.86 mg/mL.The strongest anti C.albicans activity,with the lowest MIC(mg/mL),at pH 8.0 was in the sample C,followed by samples D,A and B.In sample C,the MIC at pH 8.0 is 0.001(PBS extract).The antimicrobial activities of selected propolis samples correlate with their polyphenol content,more precisely,flavonoid,caffeic acid,chrysin,pinocembrin and galangin content.
文摘The effects ofpH, dissolved ion content and relative water velocity on the release rate of an antifouling agent, cuprous oxide, from ships＇ hull paint have been investigated by rotating cylinder tests. Additionally, test paint panels were attached to a vessel and recovered after a certain period of voyage for the validation of the laboratory tests. In the initial period, the release rates are influenced by pH, dissolved ion content and water velocity, but once after a certain period of test, those effects become less significant. These phenomena can be explained when the paint film is fresh, the rate is controlled by chemical reaction, the surface and/or diffusion layer in the water phase governs the rate. After the antifouling substance in the paint film leached out from the near-surface region, a diffused layer （leached layer）, that has little antifouling agent remained, is formed at the surface of the coating, and the diffusion in that layer can be a rate-determining process. The development of the leached layer is affected by a balance between the leaching rate of the antifouling ingredient and paint resin determined by the chemical properties and speed of the water. Thus, the leaching rates of antifouling agents are affected by the history of the paint in the water.
基金R.A.S.(CVU 703153)acknowledges the DGAPA-UNAM postdoctoral grant.S.E.M.T.(CVU 703157)acknowledges the DGAPA-UNAM postdoctoral grantP.G.Z.-B.(CVU 787342)acknowledges the CONAHCyT postdoctoral grant received.A.D.+2 种基金G.S.thank the projects PAPIIT-DGAPA-UNAM IA100123 and IG100123The authors also acknowledge the UIC-UNAM joint collaborative project for the supportThis work was supported by DGAPA PAPIIT funding IA100123.
文摘Objective:We conducted a comprehensive physicochemical analysis of one-dimensional ZnO nanowires(1DZnO),incorporating anti-CYFRA 21-1 immobilization to promote fast optical biomarker detection up to 10 ng ml−1.Impact Statement:This study highlights the effectiveness of proof-of-concept 1DZnO nanoplatforms for rapid cancer biomarker detection by examining the nanoscale integration of 1DZnO with these bioreceptors to deliver reliable photoluminescent output signals.Introduction:The urgent need for swift and accurate prognoses in healthcare settings drives the rise of sensitive biosensing nanoplatforms for cancer detection,which has benefited from biomarker identification.CYFRA 21-1 is a reliable target for the early prediction of cancer formation that can be perceptible in blood,saliva,and serum.However,1DZnO nanostructures have been barely applied for CYFRA 21-1 detection.Methods:We assessed the nanoscale interaction between 1DZnO and anti-CYFRA 21-1 antibodies to develop rapid CYFRA 21-1 detection in two distinct matrices:PhosphateBuffered Saline(PBS)buffer and artificial saliva.The chemical modifications were tracked utilizing Fourier transform infrared spectroscopy,while transmission electron microscopy and energy dispersive spectroscopy confirmed antigen-antibody interplay over nanostructures.Results:Our results show high antibody immobilization efficiencies,affirming the effectiveness of 1DZnO nanoplatforms for rapid CYFRA 21-1 testing within a 5-min detection window in both PBS and artificial saliva.Photoluminescence measurements also revealed distinct optical responses across biomarker concentrations ranging from 10 to 1,000 ng ml^(−1).Conclusion:Discernible PL signal responses obtained after 5 min affirm the potential of 1DZnO nanoplatforms for further advancement in optical biomarker detection for application in early cancer prognosis.
文摘The electrochemical behaviour of three duplex stainless steels,(SAF 2101,SAF 2304,SAF 2205)was investigated.Open circuit potential,EOC,measurements,and electrochemical impedance spectroscopy(EIS)were employed both in phosphate-buffered saline solution(PBS,pH=7.2)and in PBS simulating in vitro inflammatory conditions(PBS+H2O2,pH=5.0).It has been established that the tendency of the investigated steel materials towards corrosion de-creases in the following order:SAF 2101<SAF 2304<SAF 2205 in both ag-gressive environments.The superior corrosion resistance exhibited by SAF 2205 is ascribed to the formation of a passive film with enhanced protective effectiveness than the one formed on SAF 2101 and SAF 2304,and this im-provement is ascribed to a synergistic effect of Mo+N owing to the high mo-lybdenum content in the alloy.
基金This work was supported by the National Natural Science Foundation of China(No.82172953)the Fujian Natural Science Foundation(No.2021J01716)the National Key Clinical Specialty Construction Project Fund(No.2022YBL-ZD-02).
文摘This study investigates the targeted imaging and tumor inhibition effects of a"signal-off"imaging-based activatable aptamer probe(I-AAP)for pancreatic cancer.AS1411,contained in the I-AAP probe,targets the nucleolin and i-motifs on the membrane surfaces of pancreatic cancer cells(PANC-1)and has a dual response to pH and an acidic environment.In vitro,a"signal-off"type I-AAP probe was constructed that possesses a fluorescence effect in a phosphate buffer solution at pH 6.0 and 6.5.The probe has no fluorescence effect at pH 7.0 or 7.5;thus,the"signal-off"type I-AAP probe has a targeted acid-sensitive response in pancreatic cancer and a tumor microenvironment imaging effect.After incubation for 30 min,AS1411 was taken up by PANC-1 cells and reached its peak value within 2 h.AS1411 inhibited pancreatic cancer cells in a time-dependent manner.This"signal-off"I-AAP probe is expected to be suitable for a low-background and high-specificity molecular pathologic tracer technique,making use of the presence of nucleolins on the surface of pancreatic cancer cells and the low pH response of the tumor microenvironment.
