Titanium/magnesium alloy bimetal composites show promising prospects for lightweight applications.The Ti/Mg bimetal composite was fabricated in Ti−6Al−4V pyramidal lattice structure via AZ91D melt infiltration.Compara...Titanium/magnesium alloy bimetal composites show promising prospects for lightweight applications.The Ti/Mg bimetal composite was fabricated in Ti−6Al−4V pyramidal lattice structure via AZ91D melt infiltration.Comparative analysis of the tensile and compressive properties was conducted between the composite and its constituent materials(Ti−6Al−4V lattice structure and AZ91D matrix).The tensile strength of the composite(95.9 MPa)was comparable to that of the Ti−6Al−4V lattice structure(94.4 MPa)but lower than that of the AZ91D alloy(120.8 MPa)due to gaps at the bimetal interfaces hindering load transfer during tension.The composite exhibited greater elongation(1.7%)compared to AZ91D(1.4%)alloy but less than the Ti−6Al−4V lattice structure(2.6%).The compressive performance of the composite outperformed that of the Ti−6Al−4V lattice structure,underscoring the significance of the AZ91D alloy in compressive deformation.Fracture analysis indicated that the predominant failure reasons in both the composite and lattice structures were attributed to the breakage of lattice struts at nodes caused by the stress concentration.展开更多
BACKGROUND The surgical treatment of pelvic fractures is challenging,particularly after lum-bosacral plexus injuries.Such impairments affect a patient's physiological function and can cause significant mental heal...BACKGROUND The surgical treatment of pelvic fractures is challenging,particularly after lum-bosacral plexus injuries.Such impairments affect a patient's physiological function and can cause significant mental health problems.In recent years,the new transrectus lateral approach has favorably treated pelvic fractures and possibly preserved patients'physiological and psychological conditions.There-fore,investigating its clinical efficacy for treating pelvic fractures plus lum-bosacral plexus injuries is of great clinical significance.AIM To investigate the clinical effect of the transrectus lateral approach on pelvic fractures complicated by lumbosacral plexus injuries as well as anxiety and depression.METHODS Data of 136 patients with pelvic fractures complicated by lumbosacral plexus injuries treated by the transrectus lateral approach(January 2011 to May 2024)were retrospectively analyzed.The patients'general data were collected via questionnaire.The Self-rating Anxiety Scale(SAS)and Self-rating Depression Scale(SDS)were used to assess anxiety and depression,respectively.We adopted a numerical rating scale(NRS)to evaluate pain degree,the Pittsburgh Sleep Quality Index(PSQI)to assess sleep quality,and Medical Research Council(MRC)Scale for Muscle Strength to evaluate treatment efficacy and complications.RESULTS The 136 included patients(92 male,44 female)were a mean 48.02±15.72 years old.The mean SAS score was 66.36±5.15 preoperatively vs 42.15±4.36 postoperatively,while the mean SDS score was 65.61±5.02 preoperatively vs 43.83±4.54 postoperatively,showing statistically significant differences(P<0.05).The mean NRS and PSQI scores were significantly lower pre-vs postoperatively(P<0.05).Postoperatively,67 patients with fresh pelvic fractures plus nerve injuries achieved an MRC of M5,22 achieved an M1-M4,and four achieved an M0.Postoperative motor function improved by a mean 4.20 grades(scale,0-5).Among the patients with old pelvic fractures and nerve injuries,19 achieved an M5,16 achieved an M1-M4,and eight achieved an M0.Motor function improved significantly by a mean 3.30 grades(scale,0-5;P<0.05).No serious postoperative complications occurred.CONCLUSION The transrectus lateral approach to treating pelvic fractures plus lumbosacral plexus injuries can safely alleviate anxiety and depression,relieve pain,improve sleep quality,reduce intraoperative blood loss,and improve postoperative recovery.展开更多
To achieve Ti/Mg bimetallic composite with high strength and metallurgical bonding interface,Al interlayer and Zn/Al composite interlayer were used to prepare TC4/AZ91D bimetal composite with metallurgical bonding int...To achieve Ti/Mg bimetallic composite with high strength and metallurgical bonding interface,Al interlayer and Zn/Al composite interlayer were used to prepare TC4/AZ91D bimetal composite with metallurgical bonding interface by solid-liquid compound casting,respectively.Al interlayer was prepared on the surface of TC4 alloy by hot dipping,and Zn/Al composite interlayer was prepared by electroplating process.The results suggested that the phases across the interface were Al Ti andα(Al)+Mg_(21)(Al,Zn)_(17)when Zn/Al composite interlayer was used.When Al interlayer was used as interlayer,Al Mg Ti ternary structure and Al_(12)Mg_(17)+δ-Mg eutectic structure were the main phases at the interface.The shear strength of TC4/AZ91D bimetal with Zn/Al composite interlayer was much higher than that with pure Al interlayer,and the value of the shear strength was increased from 48.5 to 67.4 MPa.Thermodynamic models based on different compositions of the interface were established to explain the microstructure evolution of the interfacial zone.展开更多
In this study,HEA/AI composite interlayer was used to fabricate Ti/Mg bimetal composites by solidliquid compound casting process.The Al layer was prepared on the surface of TC4 alloy by hot dipping,and the FeCoNiCr HE...In this study,HEA/AI composite interlayer was used to fabricate Ti/Mg bimetal composites by solidliquid compound casting process.The Al layer was prepared on the surface of TC4 alloy by hot dipping,and the FeCoNiCr HEA layer was prepared by magnetron sputtering onto the Al layer.The influence of the HEA layer thickness and pouring temperature on interface evolution was investigated based on SEM observation and thermodynamic analysis.Results indicate that the sluggish diffusion effect of HEA can effectively inhibit the interfacial diffusion between Al and Mg,which is conducive to the formation of solid solution,especially when the thickness of HEA is 800 nm.With the increase of casting temperature from 720 ℃ to 730 ℃,740℃,and 750 ℃,α-Al(Mg),α-Al(Mg)+Al3Mg2,Al3Mg2+Al12Mg17,and Al12Mg17+δ-Mg are formed at the interface of Ti/Mg bimetal,respectively.When the thickness of the HEA layer is 800 nm and the pouring temperature is 720 ℃,the bonding strength of the Ti/Mg bimetal can reach the maximum of 93.6 MPa.展开更多
Porosity formation during solidification of aluminum-based alloys,due to hydrogen gas and alloy shrinkage,has been a major issue adversely affecting the performance of solidification products such as castings,welds or...Porosity formation during solidification of aluminum-based alloys,due to hydrogen gas and alloy shrinkage,has been a major issue adversely affecting the performance of solidification products such as castings,welds or additively manufactured components.A three-dimensional cellular automaton(CA)model has been developed,for the first time,to couple the predictions of hydrogen-induced gas porosity and shrinkage porosity during solidification microstructure evolution of a binary Al-Si alloy.The CA simulation results are validated under various cooling rates by porosity measurements in an experimental wedge die casting using X-ray micro computed tomography(XMCT)technique.This validated porosity moel provides a critical link in integrated computation materials engineering(ICME)design and manufacturing of solidification products.展开更多
Porosity is a major issue in solidification processing of metallic materials.In this work,wedge die casting experiments were designed to investigate the effect of cooling rate on microporosity in an aluminum alloy A35...Porosity is a major issue in solidification processing of metallic materials.In this work,wedge die casting experiments were designed to investigate the effect of cooling rate on microporosity in an aluminum alloy A356.Microstructure information including dendrites and porosity were measured and observed by optical microscopy and X-ray micro-computed tomography(XMCT).The effects of cooling rate on secondary dendrite arm spacing(SDAS)and porosity were discussed.The relationship between SDAS and cooling rate was established and validated using a mathematical model.Three-dimensional(3-D)porosity information,including porosity percentage,pore volume,and pore number,was determined by XMCT.With the cooling rate decreasing from a lower to a higher position of the wedge die,the observed pore number decreases,the porosity percentage increases,and the equivalent pore radius increases.Sphericity of the pores was discussed as an empirical criterion to distinguish the types of porosity.For different cooling rates,the larger the equivalent pore radius is,the lower the sphericity of the pores.This research suggests that XMCT is a useful tool to provide critical 3-D porosity information for integrated computational materials engineering(ICME)design and process optimization of solidification products.展开更多
As a novel alternative to traditional perfluoroalkyl substances(PFASs),including perfluorooctanoic acid(PFOA)and perfluorooctane sulfonate(PFOS),hexafluoroproplyene oxide trimer acid(HFPO-TA)has been detected worldwid...As a novel alternative to traditional perfluoroalkyl substances(PFASs),including perfluorooctanoic acid(PFOA)and perfluorooctane sulfonate(PFOS),hexafluoroproplyene oxide trimer acid(HFPO-TA)has been detected worldwide in surface water.Moreover,recent researches have demonstrated that HFPO-TA has stronger bioaccumulation potential and higher hepatotoxicity than PFOA.To treat these contaminants e.g.PFOA and PFOS,some photochemical techniques by adding exogenous substances had been reported.However,there is still no report for the behavior of HFPO-TA itself under direct UV irradiation.The current study investigated the photo-transformation of HFPO-TA under UV irradiation in aqueous solution.After 72 hr photoreaction,75%degradation ratio and 25%defluorination ratio were achieved under ambient condition.Reducing active species,i.e.,hydrated electrons and active hydrogen atoms,generated from water splitting played dominant roles in degradation of HFPO-TA,which was confirmed by different effects of reaction atmospheres and quenching experiments.A possible degradation pathway was proposed based on the products identification and theoretical calculations.In general,HFPO-TA would be transformed into shorter-chain PFASs,including hexafluoropropylene oxide dimer acid(HFPODA),perfluoropropionic acid(PFA)and trifluoroacetate(TFA).This research provides basic information for HFPO-TA photodegradation process and is essential to develop novel remediation techniques for HFPO-TA and other alternatives with similar structures.展开更多
This work studied the structural effects of hematite(α-Fe2 O3), 2-line ferrihydrite(HFO) and goethite(α-FeOOH) on diethyl phthalate ester(DEP) degradation. The results showed that the degradation of DEP was faster u...This work studied the structural effects of hematite(α-Fe2 O3), 2-line ferrihydrite(HFO) and goethite(α-FeOOH) on diethyl phthalate ester(DEP) degradation. The results showed that the degradation of DEP was faster under 365 nm light irradiation than in the dark in the presence of iron(hydr)oxides. The apparent kinetic rates of DEP degradation followed the order HFO > goethite ≈ hematite in the dark and HFO > hematite > goethite under 365 nm light irradiation. Two pathways governed H2 O2 decomposition efficiency on iron(hydr)oxide surfaces:(1) forming UOH on inherent surface hydroxyl groups(Fe-OH) and(2) producing O2 and H2 O on the surface oxygen vacancies. X-ray photoelectron spectroscopy(XPS) analyses indicated that HFO not only has high Fe-OH content but also has high Vo content, resulting in its low H2 O2 utilization efficiency(η). DEP was degraded through hydrogen abstraction and deesterification, and the major products were(OH)2-DEP, mono-ethyl phthalate(MEP), OH-MEP,and phthalate acid(PA). The study is important in understanding the transformation of phthalate esters in top surface soils and surface waters under ultraviolet light.展开更多
A terrestrial biotic ligand model（t-BLM） was developed to predict nickel toxicity to wheat（Triticum aestivum） root elongation in hydroponic solutions. The competitive effects of five major cations（Ca^（2＋）, Mg^...A terrestrial biotic ligand model（t-BLM） was developed to predict nickel toxicity to wheat（Triticum aestivum） root elongation in hydroponic solutions. The competitive effects of five major cations（Ca^（2＋）, Mg^（2＋）, Na~＋, K~＋and H~＋） on Ni toxicity were investigated and Mg^（2＋）was found to be a strong competitor, while H＋showed less competing effect. Besides free Ni^（2＋）,the toxicity induced by the species NiHCO_3~＋ was non-neglect able at pH 〉 7 because NiHCO_3~＋ occupied a significant fraction of total Ni under such condition. Thus, a t-BLM including Ni^（2＋）, NiHCO_3~＋, Mg^（2＋）, and H＋could successfully predict the nickel toxicity to wheat root elongation and it performed better prediction than the conventional free ion activity model.In addition, the model was examined with two sets of independent experiments, which contained multiple cations and low-molecular-weight organic acids to mimic the rhizosphere condition. The developed t-BLM well predicted nickel toxicity in both experiments since it can account in both complexation and competition effects, suggesting its potential to be used in a complicated matrix like soil solution. This study provides direct evidence that the t-BLM is a reliable method for the risk assessment of nickel in terrestrial system.展开更多
The properties of the magnetic mold in magnetic mold casting directly determine the quality of the final cast parts.In this study,the magnetic mold properties in magnetic mold casting,were studied utilizing a coupled ...The properties of the magnetic mold in magnetic mold casting directly determine the quality of the final cast parts.In this study,the magnetic mold properties in magnetic mold casting,were studied utilizing a coupled electromagnetic-structural method through numerical simulation.This study investigated key factors including equivalent stress,the distribution of tensile and compressive stresses,and the area ratio of tensile stress.It compared molds made entirely of magnetic materials with those made partially of magnetic materials.Simulation results indicate that as current increases from 4 A to 8 A,both the initial magnetic mold and the material-replaced magnetic mold initially show an increasing trend in equivalent stress,tensile-compressive stress,and the area ratio of tensile stress,peaking at 6 A before declining.After material replacement,the area ratio of tensile stress at 6 A decreases to 19.84%,representing a reduction of 29.72%.Magnetic molds comprising a combination of magnetic and non-magnetic materials exhibit sufficient strength and a reduced area ratio of tensile stress compared to those made entirely from magnetic materials.This study provides valuable insights for optimizing magnetic mold casting processes and offers practical guidance for advancing the application of magnetic molds.展开更多
Objective:To evaluate the effectiveness and safety of hyperthermia combined with chemotherapy for non-small cell lung cancer(NSCLC).Methods:All of randomized controlled trials(RCT)about hyperthermia in combination wit...Objective:To evaluate the effectiveness and safety of hyperthermia combined with chemotherapy for non-small cell lung cancer(NSCLC).Methods:All of randomized controlled trials(RCT)about hyperthermia in combination with chemotherapy(versus chemotherapy alone)were collected through Cochrane library,PubMed,EMbase,CBM,CNKI,VIP,Wanfang Database from database inception to October 2019,no limit on language.Two researchers extracted data and assess literature quality separately,and made a meta-analysis by RevMan 5.3 software.32 trials with 2361 patients,1154 in treatment group and 1152 in control group,wereincluded in the review.Results:The results of the Meta-analysis exhibited that compared with chemotherapy alone,hyperthermia combined with chemotherapy could can enhance tumor response rate[RR=1.48,95%CI(1.34,1.63),p<0.01],improve the quality of life[RR=1.67,95%CI(1.46,1,91),p<0.01];one year survival rate[RR=1.43,95%CI(1.22,1.68),p<0.01];reduce the gastrointestinal reactions[RR=0.82,95%CI(0.68,0.98),p<0.05].Meanwhile there was no significant difference in the incidence of severe myelosuppression between the two groups:WBC toxicity[RR=0.74,95%CI(0.48,1.13),p=0.16],Platelet toxicity[RR=1.24,95%CI(0.65,2.39),p=0.52].Conclusion:The results showed that for the treatment of NSCLC,the addition of hyperthermia to chemotherapy can increase the long-term and short-term effects of chemotherapy,improve the quality of life of patients,and did not significantly increase the incidence of myelosuppression.More high quality and large-scale randomized controlled trials are required in the future.展开更多
This feature article discusses the design of stable covalent organic frameworks(COFs) for the transport regulation of protons,electrons, and radicals. Transporting these particles through materials is essential for ma...This feature article discusses the design of stable covalent organic frameworks(COFs) for the transport regulation of protons,electrons, and radicals. Transporting these particles through materials is essential for many applications, and porous materials with high surface area and porosity have become powerful platforms for their development. However, the stability of the holes in the material is crucial for adjusting the transmission performance, which may change significantly when the material is not stable enough, and the structure changes when it is in service in the environment. Various strategies have been adopted to improve the stability of COFs, including introducing strong electron-donating groups into the COFs and introducing irreversible reactions into the COF synthesis process. The transport regulation in stable COFs has been explored, and the structure-function relationship has been established. The prospects and challenges of COFs for the transport regulation of protons, electrons, and radicals have also been discussed. Overall, the breakthroughs in COF field have opened new possibilities for developing advanced materials with improved transport properties. The stable COFs have potential applications in energy storage, catalysis,and sensing. However, further research is needed to understand the transport properties of COFs fully and to optimize their performance for specific applications.展开更多
基金the financial support from the National Natural Science Foundation of China(Nos.51875062,52205336)。
文摘Titanium/magnesium alloy bimetal composites show promising prospects for lightweight applications.The Ti/Mg bimetal composite was fabricated in Ti−6Al−4V pyramidal lattice structure via AZ91D melt infiltration.Comparative analysis of the tensile and compressive properties was conducted between the composite and its constituent materials(Ti−6Al−4V lattice structure and AZ91D matrix).The tensile strength of the composite(95.9 MPa)was comparable to that of the Ti−6Al−4V lattice structure(94.4 MPa)but lower than that of the AZ91D alloy(120.8 MPa)due to gaps at the bimetal interfaces hindering load transfer during tension.The composite exhibited greater elongation(1.7%)compared to AZ91D(1.4%)alloy but less than the Ti−6Al−4V lattice structure(2.6%).The compressive performance of the composite outperformed that of the Ti−6Al−4V lattice structure,underscoring the significance of the AZ91D alloy in compressive deformation.Fracture analysis indicated that the predominant failure reasons in both the composite and lattice structures were attributed to the breakage of lattice struts at nodes caused by the stress concentration.
基金Supported by National Key Research and Development Plan,No.2022YFC2504303National Natural Science Foundation of China,No.82072411+1 种基金Guangzhou Area Clinical High-tech and Major Technology Projects,No.2024PL-GX11Internal Medicine Research Fund Project of Huadu District People's Hospital,Guangzhou(Excellent Youth Project),No.2020B06.
文摘BACKGROUND The surgical treatment of pelvic fractures is challenging,particularly after lum-bosacral plexus injuries.Such impairments affect a patient's physiological function and can cause significant mental health problems.In recent years,the new transrectus lateral approach has favorably treated pelvic fractures and possibly preserved patients'physiological and psychological conditions.There-fore,investigating its clinical efficacy for treating pelvic fractures plus lum-bosacral plexus injuries is of great clinical significance.AIM To investigate the clinical effect of the transrectus lateral approach on pelvic fractures complicated by lumbosacral plexus injuries as well as anxiety and depression.METHODS Data of 136 patients with pelvic fractures complicated by lumbosacral plexus injuries treated by the transrectus lateral approach(January 2011 to May 2024)were retrospectively analyzed.The patients'general data were collected via questionnaire.The Self-rating Anxiety Scale(SAS)and Self-rating Depression Scale(SDS)were used to assess anxiety and depression,respectively.We adopted a numerical rating scale(NRS)to evaluate pain degree,the Pittsburgh Sleep Quality Index(PSQI)to assess sleep quality,and Medical Research Council(MRC)Scale for Muscle Strength to evaluate treatment efficacy and complications.RESULTS The 136 included patients(92 male,44 female)were a mean 48.02±15.72 years old.The mean SAS score was 66.36±5.15 preoperatively vs 42.15±4.36 postoperatively,while the mean SDS score was 65.61±5.02 preoperatively vs 43.83±4.54 postoperatively,showing statistically significant differences(P<0.05).The mean NRS and PSQI scores were significantly lower pre-vs postoperatively(P<0.05).Postoperatively,67 patients with fresh pelvic fractures plus nerve injuries achieved an MRC of M5,22 achieved an M1-M4,and four achieved an M0.Postoperative motor function improved by a mean 4.20 grades(scale,0-5).Among the patients with old pelvic fractures and nerve injuries,19 achieved an M5,16 achieved an M1-M4,and eight achieved an M0.Motor function improved significantly by a mean 3.30 grades(scale,0-5;P<0.05).No serious postoperative complications occurred.CONCLUSION The transrectus lateral approach to treating pelvic fractures plus lumbosacral plexus injuries can safely alleviate anxiety and depression,relieve pain,improve sleep quality,reduce intraoperative blood loss,and improve postoperative recovery.
基金supported by Graduate Scientific Research and Innovation Foundation of Chongqing,China (No. CYB21005)the National Natural Science Foundation of China (No. 51875062)China Postdoctoral Science Foundation (No. 2021M700567)。
基金the financial support from the National Natural Science Foundation of China(No.51875062)。
文摘To achieve Ti/Mg bimetallic composite with high strength and metallurgical bonding interface,Al interlayer and Zn/Al composite interlayer were used to prepare TC4/AZ91D bimetal composite with metallurgical bonding interface by solid-liquid compound casting,respectively.Al interlayer was prepared on the surface of TC4 alloy by hot dipping,and Zn/Al composite interlayer was prepared by electroplating process.The results suggested that the phases across the interface were Al Ti andα(Al)+Mg_(21)(Al,Zn)_(17)when Zn/Al composite interlayer was used.When Al interlayer was used as interlayer,Al Mg Ti ternary structure and Al_(12)Mg_(17)+δ-Mg eutectic structure were the main phases at the interface.The shear strength of TC4/AZ91D bimetal with Zn/Al composite interlayer was much higher than that with pure Al interlayer,and the value of the shear strength was increased from 48.5 to 67.4 MPa.Thermodynamic models based on different compositions of the interface were established to explain the microstructure evolution of the interfacial zone.
基金financial supports from the National Natural Science Foundation of China (No. 51875062)China Postdoctoral Science Foundation (No. 2021M700567)。
文摘In this study,HEA/AI composite interlayer was used to fabricate Ti/Mg bimetal composites by solidliquid compound casting process.The Al layer was prepared on the surface of TC4 alloy by hot dipping,and the FeCoNiCr HEA layer was prepared by magnetron sputtering onto the Al layer.The influence of the HEA layer thickness and pouring temperature on interface evolution was investigated based on SEM observation and thermodynamic analysis.Results indicate that the sluggish diffusion effect of HEA can effectively inhibit the interfacial diffusion between Al and Mg,which is conducive to the formation of solid solution,especially when the thickness of HEA is 800 nm.With the increase of casting temperature from 720 ℃ to 730 ℃,740℃,and 750 ℃,α-Al(Mg),α-Al(Mg)+Al3Mg2,Al3Mg2+Al12Mg17,and Al12Mg17+δ-Mg are formed at the interface of Ti/Mg bimetal,respectively.When the thickness of the HEA layer is 800 nm and the pouring temperature is 720 ℃,the bonding strength of the Ti/Mg bimetal can reach the maximum of 93.6 MPa.
基金the National Science Foundation for supporting this work(Award CMMI-1432688)supported by Honda R&D Americas(Raymond,Ohio)。
文摘Porosity formation during solidification of aluminum-based alloys,due to hydrogen gas and alloy shrinkage,has been a major issue adversely affecting the performance of solidification products such as castings,welds or additively manufactured components.A three-dimensional cellular automaton(CA)model has been developed,for the first time,to couple the predictions of hydrogen-induced gas porosity and shrinkage porosity during solidification microstructure evolution of a binary Al-Si alloy.The CA simulation results are validated under various cooling rates by porosity measurements in an experimental wedge die casting using X-ray micro computed tomography(XMCT)technique.This validated porosity moel provides a critical link in integrated computation materials engineering(ICME)design and manufacturing of solidification products.
文摘Porosity is a major issue in solidification processing of metallic materials.In this work,wedge die casting experiments were designed to investigate the effect of cooling rate on microporosity in an aluminum alloy A356.Microstructure information including dendrites and porosity were measured and observed by optical microscopy and X-ray micro-computed tomography(XMCT).The effects of cooling rate on secondary dendrite arm spacing(SDAS)and porosity were discussed.The relationship between SDAS and cooling rate was established and validated using a mathematical model.Three-dimensional(3-D)porosity information,including porosity percentage,pore volume,and pore number,was determined by XMCT.With the cooling rate decreasing from a lower to a higher position of the wedge die,the observed pore number decreases,the porosity percentage increases,and the equivalent pore radius increases.Sphericity of the pores was discussed as an empirical criterion to distinguish the types of porosity.For different cooling rates,the larger the equivalent pore radius is,the lower the sphericity of the pores.This research suggests that XMCT is a useful tool to provide critical 3-D porosity information for integrated computational materials engineering(ICME)design and process optimization of solidification products.
基金funded by the Chinese Academy of Engineering Consulting Project(No.2019-XZ-24)the National Key Re-search and Development Plans of Special Project for Site Soil(No.2018YFC1801002)。
文摘As a novel alternative to traditional perfluoroalkyl substances(PFASs),including perfluorooctanoic acid(PFOA)and perfluorooctane sulfonate(PFOS),hexafluoroproplyene oxide trimer acid(HFPO-TA)has been detected worldwide in surface water.Moreover,recent researches have demonstrated that HFPO-TA has stronger bioaccumulation potential and higher hepatotoxicity than PFOA.To treat these contaminants e.g.PFOA and PFOS,some photochemical techniques by adding exogenous substances had been reported.However,there is still no report for the behavior of HFPO-TA itself under direct UV irradiation.The current study investigated the photo-transformation of HFPO-TA under UV irradiation in aqueous solution.After 72 hr photoreaction,75%degradation ratio and 25%defluorination ratio were achieved under ambient condition.Reducing active species,i.e.,hydrated electrons and active hydrogen atoms,generated from water splitting played dominant roles in degradation of HFPO-TA,which was confirmed by different effects of reaction atmospheres and quenching experiments.A possible degradation pathway was proposed based on the products identification and theoretical calculations.In general,HFPO-TA would be transformed into shorter-chain PFASs,including hexafluoropropylene oxide dimer acid(HFPODA),perfluoropropionic acid(PFA)and trifluoroacetate(TFA).This research provides basic information for HFPO-TA photodegradation process and is essential to develop novel remediation techniques for HFPO-TA and other alternatives with similar structures.
基金funded by the National Natural Science Foundation of China (No. 41773125)the Research Instrument Development Program of Chinese Academy of Sciences (No. YZ201638)the 135 Research Program of the Chinese Academy of Sciences (No. ISSASIP1620)
文摘This work studied the structural effects of hematite(α-Fe2 O3), 2-line ferrihydrite(HFO) and goethite(α-FeOOH) on diethyl phthalate ester(DEP) degradation. The results showed that the degradation of DEP was faster under 365 nm light irradiation than in the dark in the presence of iron(hydr)oxides. The apparent kinetic rates of DEP degradation followed the order HFO > goethite ≈ hematite in the dark and HFO > hematite > goethite under 365 nm light irradiation. Two pathways governed H2 O2 decomposition efficiency on iron(hydr)oxide surfaces:(1) forming UOH on inherent surface hydroxyl groups(Fe-OH) and(2) producing O2 and H2 O on the surface oxygen vacancies. X-ray photoelectron spectroscopy(XPS) analyses indicated that HFO not only has high Fe-OH content but also has high Vo content, resulting in its low H2 O2 utilization efficiency(η). DEP was degraded through hydrogen abstraction and deesterification, and the major products were(OH)2-DEP, mono-ethyl phthalate(MEP), OH-MEP,and phthalate acid(PA). The study is important in understanding the transformation of phthalate esters in top surface soils and surface waters under ultraviolet light.
基金the Natural Science Foundation of China(Nos.21577062 and 21277068)the Key Research and Development Program of Jiangsu Province(No.BE2015708)for financial support
文摘A terrestrial biotic ligand model（t-BLM） was developed to predict nickel toxicity to wheat（Triticum aestivum） root elongation in hydroponic solutions. The competitive effects of five major cations（Ca^（2＋）, Mg^（2＋）, Na~＋, K~＋and H~＋） on Ni toxicity were investigated and Mg^（2＋）was found to be a strong competitor, while H＋showed less competing effect. Besides free Ni^（2＋）,the toxicity induced by the species NiHCO_3~＋ was non-neglect able at pH 〉 7 because NiHCO_3~＋ occupied a significant fraction of total Ni under such condition. Thus, a t-BLM including Ni^（2＋）, NiHCO_3~＋, Mg^（2＋）, and H＋could successfully predict the nickel toxicity to wheat root elongation and it performed better prediction than the conventional free ion activity model.In addition, the model was examined with two sets of independent experiments, which contained multiple cations and low-molecular-weight organic acids to mimic the rhizosphere condition. The developed t-BLM well predicted nickel toxicity in both experiments since it can account in both complexation and competition effects, suggesting its potential to be used in a complicated matrix like soil solution. This study provides direct evidence that the t-BLM is a reliable method for the risk assessment of nickel in terrestrial system.
基金the National Natural Science Foundation of China(No.51875062,No.52205336)the China Postdoctoral Science Foundation(No.2021M700567).
文摘The properties of the magnetic mold in magnetic mold casting directly determine the quality of the final cast parts.In this study,the magnetic mold properties in magnetic mold casting,were studied utilizing a coupled electromagnetic-structural method through numerical simulation.This study investigated key factors including equivalent stress,the distribution of tensile and compressive stresses,and the area ratio of tensile stress.It compared molds made entirely of magnetic materials with those made partially of magnetic materials.Simulation results indicate that as current increases from 4 A to 8 A,both the initial magnetic mold and the material-replaced magnetic mold initially show an increasing trend in equivalent stress,tensile-compressive stress,and the area ratio of tensile stress,peaking at 6 A before declining.After material replacement,the area ratio of tensile stress at 6 A decreases to 19.84%,representing a reduction of 29.72%.Magnetic molds comprising a combination of magnetic and non-magnetic materials exhibit sufficient strength and a reduced area ratio of tensile stress compared to those made entirely from magnetic materials.This study provides valuable insights for optimizing magnetic mold casting processes and offers practical guidance for advancing the application of magnetic molds.
基金Jiangsu Province"Twelfth Five-Year"Key Discipline of Chinese Medicine(No.js1302)
文摘Objective:To evaluate the effectiveness and safety of hyperthermia combined with chemotherapy for non-small cell lung cancer(NSCLC).Methods:All of randomized controlled trials(RCT)about hyperthermia in combination with chemotherapy(versus chemotherapy alone)were collected through Cochrane library,PubMed,EMbase,CBM,CNKI,VIP,Wanfang Database from database inception to October 2019,no limit on language.Two researchers extracted data and assess literature quality separately,and made a meta-analysis by RevMan 5.3 software.32 trials with 2361 patients,1154 in treatment group and 1152 in control group,wereincluded in the review.Results:The results of the Meta-analysis exhibited that compared with chemotherapy alone,hyperthermia combined with chemotherapy could can enhance tumor response rate[RR=1.48,95%CI(1.34,1.63),p<0.01],improve the quality of life[RR=1.67,95%CI(1.46,1,91),p<0.01];one year survival rate[RR=1.43,95%CI(1.22,1.68),p<0.01];reduce the gastrointestinal reactions[RR=0.82,95%CI(0.68,0.98),p<0.05].Meanwhile there was no significant difference in the incidence of severe myelosuppression between the two groups:WBC toxicity[RR=0.74,95%CI(0.48,1.13),p=0.16],Platelet toxicity[RR=1.24,95%CI(0.65,2.39),p=0.52].Conclusion:The results showed that for the treatment of NSCLC,the addition of hyperthermia to chemotherapy can increase the long-term and short-term effects of chemotherapy,improve the quality of life of patients,and did not significantly increase the incidence of myelosuppression.More high quality and large-scale randomized controlled trials are required in the future.
基金supported by the National Natural Science Foundation of China (21975078)the Start-Up Foundation of Sichuan University。
文摘This feature article discusses the design of stable covalent organic frameworks(COFs) for the transport regulation of protons,electrons, and radicals. Transporting these particles through materials is essential for many applications, and porous materials with high surface area and porosity have become powerful platforms for their development. However, the stability of the holes in the material is crucial for adjusting the transmission performance, which may change significantly when the material is not stable enough, and the structure changes when it is in service in the environment. Various strategies have been adopted to improve the stability of COFs, including introducing strong electron-donating groups into the COFs and introducing irreversible reactions into the COF synthesis process. The transport regulation in stable COFs has been explored, and the structure-function relationship has been established. The prospects and challenges of COFs for the transport regulation of protons, electrons, and radicals have also been discussed. Overall, the breakthroughs in COF field have opened new possibilities for developing advanced materials with improved transport properties. The stable COFs have potential applications in energy storage, catalysis,and sensing. However, further research is needed to understand the transport properties of COFs fully and to optimize their performance for specific applications.
