Tris （2, 2′-bipyridine） ruthenium （Ⅱ） （Ru（bpy）3^2＋） dichloride was successfully immobilized into the galleria of layered gamma zirconium phosphate （γ-ZrP） preintercalated by butyl amine（BA）. The compou...Tris （2, 2′-bipyridine） ruthenium （Ⅱ） （Ru（bpy）3^2＋） dichloride was successfully immobilized into the galleria of layered gamma zirconium phosphate （γ-ZrP） preintercalated by butyl amine（BA）. The compounds showed extended luminescence lifetime of about four times of unimmobilized metal complex.展开更多
Zinc tris Thiourea Sulphate (ZTS) is a semi organic non-linear optical crystal. The ZTS and phosphate mixed (in different mol %) ZTS crystals have been grown from aqueous solution using the slow evaporation method. Si...Zinc tris Thiourea Sulphate (ZTS) is a semi organic non-linear optical crystal. The ZTS and phosphate mixed (in different mol %) ZTS crystals have been grown from aqueous solution using the slow evaporation method. Single crystal XRD were carried out for ZTS and phosphate mixed ZTS crystals to determine cell parameters. FTIR analysis identified modes of vibrations of different molecular groups and confirms the presence of phosphate ion. The UV-Vis-NIR spectrum shows that the material has wide optical transparency in the entire visible region. The second harmonic generation (SHG) was confirmed by Kurtz powder method. It is found that 10 mol % of phosphate mixed ZTS crystal has better SHG efficiency than pure ZTS crystal. The Vicker microhardness test was carried out on the grown crystals and Vicker’s Hardness Number was found increase with increase in phosphate mixing.展开更多
Tricalcium phosphate Anhydrous Powder typically contains less than 10 ppm (mg/Kg) (w/w) manganese. This level can be determined utilizing Flame Atomic Absorption Spectrometer (AAS) and standard based on known standard...Tricalcium phosphate Anhydrous Powder typically contains less than 10 ppm (mg/Kg) (w/w) manganese. This level can be determined utilizing Flame Atomic Absorption Spectrometer (AAS) and standard based on known standards. A number of analytical methods are presently used for the analysis of metals in the biochemical. The instrumental techniques available are Inductively Coupled Plasma (ICP/MS), X-Ray Fluorescence, UV-VIS Spectrophotometry, and Atomic Absorption Spectrometry. Flame AA has gained widespread acceptance as an analytical technique and is used for many applications. In this study, we have determined the amount of manganese metal present in Tricalcium Phosphate (TCP) using Flame Atomic Absorption Spectrophotometer. The method has high precision and accuracy. The percent recovery was found to be 99.8% for spiked sample. The results meet the requirement.展开更多
Tri-n-butyl phosphate（TBP）dissolved in kerosene was chosen as extractant for lithium from a modelbrine having high magnesium-to-lithium ratio and ferric chloride was added to the system.The influences of con-tact ti...Tri-n-butyl phosphate（TBP）dissolved in kerosene was chosen as extractant for lithium from a modelbrine having high magnesium-to-lithium ratio and ferric chloride was added to the system.The influences of con-tact time,concentration of the extractant,concentrations of some salts(Mg<sup>2+</sup>, Na<sup>+</sup>,K<sup>+</sup>)in the solution,acid-ity of hydrochloric acid and extraction temperature on the exttaction of lithium with TBP-kerosene system werestudied.The suitable extraction conditions were found to be:contact time not any less than 20min;at 20-25C;[Fe<sup>+3</sup>]/[Li<sup>+</sup>]about 1.5-2.0;TBP concentration 50%-70%;[MgCl<sub>2</sub>]exceeding 3 mol·L<sup>-1</sup>;pH about 2;while most sodium and potassium salts in the aqueous phase should be removed before the extraction.展开更多
Studies have been made on the extraction of Zn and Cd by TBP(tri-n-butyl phosphate) from diluent hydrochloric acid solutions of soldium chloride.The experiments show that the species extracted from diluent HCI solutio...Studies have been made on the extraction of Zn and Cd by TBP(tri-n-butyl phosphate) from diluent hydrochloric acid solutions of soldium chloride.The experiments show that the species extracted from diluent HCI solutions of NaCl appear to be predominantly ZnCl_2· 2TBP and CdCl_2·2TBP.For Cd,at lower acidities,anionic complexes of the type H_2CdCl_3 are also extracted.As the acidity is increased,H_2CdCl_4 appear to be predominant complexes in organic phase.For Zn,the acidocomplexes of the type HZnCl_3 appear in organ- ic phase after the acidity of solutions reaching a certain value([HCl]>0.1 mol/L). Furthermore,the ultraviolet absorption spectra of both aqueous and organic phases have been studied,and the infrared spectra of the organic phases have been exomined.The extraction mechanism and temperature effect are also discussed.展开更多
The synergistic extraction of uranium (VI) from nitric acid aqueous solution with a mixture of tri-n-butyl phosphate (TBP) and petroleum sulfoxides(PSO) in benzene was studied. It has been found that the maximum syner...The synergistic extraction of uranium (VI) from nitric acid aqueous solution with a mixture of tri-n-butyl phosphate (TBP) and petroleum sulfoxides(PSO) in benzene was studied. It has been found that the maximum synergistic extraction effect occurs where the molar ratio of PSO to TBP is one to two. The composition of the complex of synergistic extraction is UO2(NO3)2-TBP.PSO. The formation constant of the complex KTp=57.44.展开更多
Tri(2-chloropropyl)phosphate(TCPP)was an emerging contaminant of global concern because of its frequent occurrence,potential toxic effects,and persistence in the environment.Microbial degradation might be an efficient...Tri(2-chloropropyl)phosphate(TCPP)was an emerging contaminant of global concern because of its frequent occurrence,potential toxic effects,and persistence in the environment.Microbial degradation might be an efficient and safe removal method,but limited information was available.In this study,Providencia rettgeri was isolated from contaminated sediment and showed it could use TCPP as unique phosphorus source to promote growth,and decompose 34.7%of TCPP(1 mg/L)within 5 days.The microbial inoculation and the initial concentration of TCPP could affect the biodegradation efficient.Further study results indicated that TCPP decomposition by Providencia rettgeri was mainly via phosphoester bond hydrolysis,evidenced by the production of bis(2-chloropropyl)phosphate(C_(6)H_(13)Cl_(2)PO_(4))and mono-chloropropyl phosphate(C_(3)H_(8)ClPO_(4)).Both intracellular and extracellular enzymes could degrade TCPP,but intracellular degradation was dominant in the later reaction stage,and the presence of Cu^(2+) ions had a promoting effect.These findings developed novel insights into the potential mechanism of TCPP microbial degradation.展开更多
将三(1-氧代-1-磷杂-2,6,7-三氧杂双环[2,2,2]辛烷-4-亚甲基)磷酸酯(trimer)用于阻燃聚碳酸酯(PC),研究了它对 PC 阻燃性能、机械性能、热分解行为及灼烧残炭的影响。将 trimer 用于 PC 时,其质量分数为8%的用量即可使 PC 的阻燃级别达...将三(1-氧代-1-磷杂-2,6,7-三氧杂双环[2,2,2]辛烷-4-亚甲基)磷酸酯(trimer)用于阻燃聚碳酸酯(PC),研究了它对 PC 阻燃性能、机械性能、热分解行为及灼烧残炭的影响。将 trimer 用于 PC 时,其质量分数为8%的用量即可使 PC 的阻燃级别达到 UL 94 V-O(试样厚度为3.2 mm)级,极限氧指数达33%。值得注意的是,加入 trimer 可改善 PC 的拉伸强度,特别是弯曲强度及弯曲模量。热分析数据表明,trimer 可提前并加速 PC 的交联成炭,但不能提高PC 的成炭率。此外,扫描电子最微镜照片显示,trimer 可使炭层轻微发泡膨胀,也可改善炭层质量。展开更多
Tris(2-chloroethyl) phosphate(TCEP) is a typical phosphate flame retardant. Its potential adverse health effects have recently aroused concern. We investigated the seasonal variations of TCEP concentrations in the raw...Tris(2-chloroethyl) phosphate(TCEP) is a typical phosphate flame retardant. Its potential adverse health effects have recently aroused concern. We investigated the seasonal variations of TCEP concentrations in the raw, finished and tap water samples from two drinking water treatment plants(DWTPs) in China, and evaluated the cytotoxicity and apoptosis/necrosis of organic extracts(OEs) in water samples. We enriched TCEP and OEs in water samples by solid-phase extraction method. The TCEP concentrations in water samples were determined by gas chromatography–mass spectrometry. Normal human liver cell line L02 was treated with OEs in the water samples, and then the cytotoxicity and apoptosis/necrosis were measured by 3-(4, 5-dimethyithiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay and flow cytometry, respectively. The results showed that cytotoxicities of OEs in raw water samples from both DWTPs in summer and winter were stronger than those in spring and autumn, cytotoxicity of OEs in finished and tap water samples from both DWTPs in summer and autumn were stronger than those in spring and winter. In all seasons, the maximal concentrations(100 mL water/mL cell culture) of OEs in the raw water samples from both DWTPs induced late apoptosis/necrosis. The reasons for seasonal variations of TCEP in water samples and potential toxic effects of other pollutants in the water samples need to be further investigated.展开更多
Resorbable bioceramics are attractive for medical applications such as bone substitution. Biochemical analysis on cells cultured on these biomaterials is vital to predict the impact of the materials in vivo and RNA ex...Resorbable bioceramics are attractive for medical applications such as bone substitution. Biochemical analysis on cells cultured on these biomaterials is vital to predict the impact of the materials in vivo and RNA extraction is an essential step in gene expression study using RT-qPCR. In this study, we describe simple modifications to the TRIzol? RNA extraction protocol widely used in biology and these allow high-yield extraction of RNA from cells on resorbable calcium phosphates. Without the modifications, RNA is trapped in the co-precipitated calcium compounds, rendering TRIzol? extraction method infeasible. Among the modifications, the use of extra TRIzol? to dilute the lysate before the RNA precipitation step is critical for extraction of RNA from porous ?-tricalcium phosphate (?-TCP) discs. We also investigate the rationale behind the undesirable precipitation so as to provide clues about the modifications required for other resorbable materials with high application potential in bone tissue engineering.展开更多
Phosphatidylinositol polyphosphate (PIPx) are related with tyrosine kinase activation and cell proliferation and carcinogenesis. PIPx is an important target compound for synthetic organic chemist. PIPx having saturate...Phosphatidylinositol polyphosphate (PIPx) are related with tyrosine kinase activation and cell proliferation and carcinogenesis. PIPx is an important target compound for synthetic organic chemist. PIPx having saturated fatty acid components have been reported. Recently we have succeeded in the synthesis of phosphatydylinositol-3,4,5-trisphosphate with unsaturated fatty acid component by the reaction of diethyl chlorophosphite with 1,2-di-O-cyclohexylidene-3,4-0-(tetraisopropyldisiloxane 1,3-diyl)-6-O-(4-oxopentanoyl)-myo-inositol.展开更多
Tri(2-chloroethyl) phosphate(TCEP) with the initial concentration of 5 mg/L was degraded by UV/H2O2 oxidation process. The removal rate of TCEP in the UV/H2O2 system was 89.1% with the production of Cl-and PO4^3- of 0...Tri(2-chloroethyl) phosphate(TCEP) with the initial concentration of 5 mg/L was degraded by UV/H2O2 oxidation process. The removal rate of TCEP in the UV/H2O2 system was 89.1% with the production of Cl-and PO4^3- of 0.23 and 0.64 mg/L. The removal rate of total organic carbon of the reaction was 48.8% and the pH reached 3.3 after the reaction. The oxidative degradation process of TCEP in the UV/H2O2 system obeyed the first order kinetic reaction with the apparent rate constant of 0.0025 min^-1( R^2 = 0.9788). The intermediate products were isolated and identified by gas chromatography-mass spectrometer. The addition reaction of HO · and H2O and the oxidation reaction with H2O2 were found during the degradation pathway of 5 mg/L TCEP in the UV/H2O2 system. For the first time, environment risk was estimated via the "ecological structure activity relationships" program and acute and chronic toxicity changes of intermediate products were pointed out. The luminescence inhibition rate of photobacterium was used to evaluate the acute toxicity of intermediate products. The results showed that the toxicity of the intermediate products increased with the increase of reaction time, which may be due to the production of chlorine compounds. Some measures should be introduced to the UV/H2O2 system to remove the highly toxic Cl-containing compounds, such as a nanofiltration or reverse osmosis unit.展开更多
Magnesium phosphate cements have come under investigation in recent years for use as an alternative to calcium phosphate cements for bone void repair applications.Evidence indicates that magnesium phosphate cements ob...Magnesium phosphate cements have come under investigation in recent years for use as an alternative to calcium phosphate cements for bone void repair applications.Evidence indicates that magnesium phosphate cements obtain higher initial strengths after cement reaction and resorption in more clinically appropriate time frames than commercially available calcium phosphate cements.In this study,amorphous,partially amorphous and crystalline tri-magnesium phosphate powders were synthesized via an aqueous precipitation reaction with subsequent thermal treatment,and characterized using techniques such as X-ray diffraction and Fourier transform infrared spectroscopy.These materials were assessed for their functionality in cementing reaction with a 3.0 mol/L,pH 7.0 ammonium phosphate solution,including setting time and pH evolution in phosphate buffered saline solution.Results indicated that the amorphous and semi-crystalline tri-magnesium phosphate powders were highly reactive with the setting solution but resulted in mechanically weak cements,while the crystalline tri-magnesium phosphate powder reacted efficiently with the cement solution and were mechanically strong following the cement reaction.X-ray diffraction and scanning electron microscopy analyses indicated significant changes in the phase composition and morphology of the cements following incubation in phosphate buffered saline.These were perceived to be detrimental to the integrity of the amorphous and semi-crystalline tri-magnesium phosphate derived cements but not to those created with fully crystalline tri-magnesium phosphate.The crystalline tri-magnesium phosphate material resulted in the most functional cement as this embodiment displayed the most clinically relevant setting time as well as the highest mechanical resilience and neutral pH during incubation in saline solution rendering them potentially viable as bone void fillers.展开更多
基金This work was supported by the National Science Foundation of China(Nos.20475004,and 20271004).
文摘Tris （2, 2′-bipyridine） ruthenium （Ⅱ） （Ru（bpy）3^2＋） dichloride was successfully immobilized into the galleria of layered gamma zirconium phosphate （γ-ZrP） preintercalated by butyl amine（BA）. The compounds showed extended luminescence lifetime of about four times of unimmobilized metal complex.
文摘Zinc tris Thiourea Sulphate (ZTS) is a semi organic non-linear optical crystal. The ZTS and phosphate mixed (in different mol %) ZTS crystals have been grown from aqueous solution using the slow evaporation method. Single crystal XRD were carried out for ZTS and phosphate mixed ZTS crystals to determine cell parameters. FTIR analysis identified modes of vibrations of different molecular groups and confirms the presence of phosphate ion. The UV-Vis-NIR spectrum shows that the material has wide optical transparency in the entire visible region. The second harmonic generation (SHG) was confirmed by Kurtz powder method. It is found that 10 mol % of phosphate mixed ZTS crystal has better SHG efficiency than pure ZTS crystal. The Vicker microhardness test was carried out on the grown crystals and Vicker’s Hardness Number was found increase with increase in phosphate mixing.
文摘Tricalcium phosphate Anhydrous Powder typically contains less than 10 ppm (mg/Kg) (w/w) manganese. This level can be determined utilizing Flame Atomic Absorption Spectrometer (AAS) and standard based on known standards. A number of analytical methods are presently used for the analysis of metals in the biochemical. The instrumental techniques available are Inductively Coupled Plasma (ICP/MS), X-Ray Fluorescence, UV-VIS Spectrophotometry, and Atomic Absorption Spectrometry. Flame AA has gained widespread acceptance as an analytical technique and is used for many applications. In this study, we have determined the amount of manganese metal present in Tricalcium Phosphate (TCP) using Flame Atomic Absorption Spectrophotometer. The method has high precision and accuracy. The percent recovery was found to be 99.8% for spiked sample. The results meet the requirement.
文摘Tri-n-butyl phosphate（TBP）dissolved in kerosene was chosen as extractant for lithium from a modelbrine having high magnesium-to-lithium ratio and ferric chloride was added to the system.The influences of con-tact time,concentration of the extractant,concentrations of some salts(Mg<sup>2+</sup>, Na<sup>+</sup>,K<sup>+</sup>)in the solution,acid-ity of hydrochloric acid and extraction temperature on the exttaction of lithium with TBP-kerosene system werestudied.The suitable extraction conditions were found to be:contact time not any less than 20min;at 20-25C;[Fe<sup>+3</sup>]/[Li<sup>+</sup>]about 1.5-2.0;TBP concentration 50%-70%;[MgCl<sub>2</sub>]exceeding 3 mol·L<sup>-1</sup>;pH about 2;while most sodium and potassium salts in the aqueous phase should be removed before the extraction.
文摘Studies have been made on the extraction of Zn and Cd by TBP(tri-n-butyl phosphate) from diluent hydrochloric acid solutions of soldium chloride.The experiments show that the species extracted from diluent HCI solutions of NaCl appear to be predominantly ZnCl_2· 2TBP and CdCl_2·2TBP.For Cd,at lower acidities,anionic complexes of the type H_2CdCl_3 are also extracted.As the acidity is increased,H_2CdCl_4 appear to be predominant complexes in organic phase.For Zn,the acidocomplexes of the type HZnCl_3 appear in organ- ic phase after the acidity of solutions reaching a certain value([HCl]>0.1 mol/L). Furthermore,the ultraviolet absorption spectra of both aqueous and organic phases have been studied,and the infrared spectra of the organic phases have been exomined.The extraction mechanism and temperature effect are also discussed.
基金Supported by the National Natural Science Foundation of China (20171029)
文摘The synergistic extraction of uranium (VI) from nitric acid aqueous solution with a mixture of tri-n-butyl phosphate (TBP) and petroleum sulfoxides(PSO) in benzene was studied. It has been found that the maximum synergistic extraction effect occurs where the molar ratio of PSO to TBP is one to two. The composition of the complex of synergistic extraction is UO2(NO3)2-TBP.PSO. The formation constant of the complex KTp=57.44.
基金This work was supported by the Natural Science Foundation of Guangdong Province(No.2023A1515030284)the Key Realm Research and Development Program of Guangdong Province(No.2020B0202080001)+1 种基金the Guangdong Laboratory for Lingnan Modern Agriculture Project(No.NT2021010)the Science and Technology Planning Project of Guangdong Province(No.2021B1212040008).
文摘Tri(2-chloropropyl)phosphate(TCPP)was an emerging contaminant of global concern because of its frequent occurrence,potential toxic effects,and persistence in the environment.Microbial degradation might be an efficient and safe removal method,but limited information was available.In this study,Providencia rettgeri was isolated from contaminated sediment and showed it could use TCPP as unique phosphorus source to promote growth,and decompose 34.7%of TCPP(1 mg/L)within 5 days.The microbial inoculation and the initial concentration of TCPP could affect the biodegradation efficient.Further study results indicated that TCPP decomposition by Providencia rettgeri was mainly via phosphoester bond hydrolysis,evidenced by the production of bis(2-chloropropyl)phosphate(C_(6)H_(13)Cl_(2)PO_(4))and mono-chloropropyl phosphate(C_(3)H_(8)ClPO_(4)).Both intracellular and extracellular enzymes could degrade TCPP,but intracellular degradation was dominant in the later reaction stage,and the presence of Cu^(2+) ions had a promoting effect.These findings developed novel insights into the potential mechanism of TCPP microbial degradation.
文摘将三(1-氧代-1-磷杂-2,6,7-三氧杂双环[2,2,2]辛烷-4-亚甲基)磷酸酯(trimer)用于阻燃聚碳酸酯(PC),研究了它对 PC 阻燃性能、机械性能、热分解行为及灼烧残炭的影响。将 trimer 用于 PC 时,其质量分数为8%的用量即可使 PC 的阻燃级别达到 UL 94 V-O(试样厚度为3.2 mm)级,极限氧指数达33%。值得注意的是,加入 trimer 可改善 PC 的拉伸强度,特别是弯曲强度及弯曲模量。热分析数据表明,trimer 可提前并加速 PC 的交联成炭,但不能提高PC 的成炭率。此外,扫描电子最微镜照片显示,trimer 可使炭层轻微发泡膨胀,也可改善炭层质量。
基金supported by the National Natural Science Foundations of China (Nos.81273023 and 81472947)
文摘Tris(2-chloroethyl) phosphate(TCEP) is a typical phosphate flame retardant. Its potential adverse health effects have recently aroused concern. We investigated the seasonal variations of TCEP concentrations in the raw, finished and tap water samples from two drinking water treatment plants(DWTPs) in China, and evaluated the cytotoxicity and apoptosis/necrosis of organic extracts(OEs) in water samples. We enriched TCEP and OEs in water samples by solid-phase extraction method. The TCEP concentrations in water samples were determined by gas chromatography–mass spectrometry. Normal human liver cell line L02 was treated with OEs in the water samples, and then the cytotoxicity and apoptosis/necrosis were measured by 3-(4, 5-dimethyithiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay and flow cytometry, respectively. The results showed that cytotoxicities of OEs in raw water samples from both DWTPs in summer and winter were stronger than those in spring and autumn, cytotoxicity of OEs in finished and tap water samples from both DWTPs in summer and autumn were stronger than those in spring and winter. In all seasons, the maximal concentrations(100 mL water/mL cell culture) of OEs in the raw water samples from both DWTPs induced late apoptosis/necrosis. The reasons for seasonal variations of TCEP in water samples and potential toxic effects of other pollutants in the water samples need to be further investigated.
文摘Resorbable bioceramics are attractive for medical applications such as bone substitution. Biochemical analysis on cells cultured on these biomaterials is vital to predict the impact of the materials in vivo and RNA extraction is an essential step in gene expression study using RT-qPCR. In this study, we describe simple modifications to the TRIzol? RNA extraction protocol widely used in biology and these allow high-yield extraction of RNA from cells on resorbable calcium phosphates. Without the modifications, RNA is trapped in the co-precipitated calcium compounds, rendering TRIzol? extraction method infeasible. Among the modifications, the use of extra TRIzol? to dilute the lysate before the RNA precipitation step is critical for extraction of RNA from porous ?-tricalcium phosphate (?-TCP) discs. We also investigate the rationale behind the undesirable precipitation so as to provide clues about the modifications required for other resorbable materials with high application potential in bone tissue engineering.
文摘Phosphatidylinositol polyphosphate (PIPx) are related with tyrosine kinase activation and cell proliferation and carcinogenesis. PIPx is an important target compound for synthetic organic chemist. PIPx having saturated fatty acid components have been reported. Recently we have succeeded in the synthesis of phosphatydylinositol-3,4,5-trisphosphate with unsaturated fatty acid component by the reaction of diethyl chlorophosphite with 1,2-di-O-cyclohexylidene-3,4-0-(tetraisopropyldisiloxane 1,3-diyl)-6-O-(4-oxopentanoyl)-myo-inositol.
基金supported by the National Nature Science Foundation of China (No. 21777067)the Primary Research&Development Plan of Jiangsu Province (No. BE2019679)+1 种基金Open Fund of National Key Laboratory of Collaborative Control and Remediation of Soil and Water Pollution for Environmental Protection (No. GHBK-001)the Open Fund of the State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration,Northeast Normal University (No. 130028903)。
文摘Tri(2-chloroethyl) phosphate(TCEP) with the initial concentration of 5 mg/L was degraded by UV/H2O2 oxidation process. The removal rate of TCEP in the UV/H2O2 system was 89.1% with the production of Cl-and PO4^3- of 0.23 and 0.64 mg/L. The removal rate of total organic carbon of the reaction was 48.8% and the pH reached 3.3 after the reaction. The oxidative degradation process of TCEP in the UV/H2O2 system obeyed the first order kinetic reaction with the apparent rate constant of 0.0025 min^-1( R^2 = 0.9788). The intermediate products were isolated and identified by gas chromatography-mass spectrometer. The addition reaction of HO · and H2O and the oxidation reaction with H2O2 were found during the degradation pathway of 5 mg/L TCEP in the UV/H2O2 system. For the first time, environment risk was estimated via the "ecological structure activity relationships" program and acute and chronic toxicity changes of intermediate products were pointed out. The luminescence inhibition rate of photobacterium was used to evaluate the acute toxicity of intermediate products. The results showed that the toxicity of the intermediate products increased with the increase of reaction time, which may be due to the production of chlorine compounds. Some measures should be introduced to the UV/H2O2 system to remove the highly toxic Cl-containing compounds, such as a nanofiltration or reverse osmosis unit.
基金the financial support of the National Science Foundation(Grant #0933153)Edward R.Weidlein Chair Professorship Funds,University of Pittsburgh,the Center for Complex Engineered Multifunctional Materials(CCEMM), University of PittsburghThe National Science Foundation Graduate Research Fellowship Program(DGE-1247842)
文摘Magnesium phosphate cements have come under investigation in recent years for use as an alternative to calcium phosphate cements for bone void repair applications.Evidence indicates that magnesium phosphate cements obtain higher initial strengths after cement reaction and resorption in more clinically appropriate time frames than commercially available calcium phosphate cements.In this study,amorphous,partially amorphous and crystalline tri-magnesium phosphate powders were synthesized via an aqueous precipitation reaction with subsequent thermal treatment,and characterized using techniques such as X-ray diffraction and Fourier transform infrared spectroscopy.These materials were assessed for their functionality in cementing reaction with a 3.0 mol/L,pH 7.0 ammonium phosphate solution,including setting time and pH evolution in phosphate buffered saline solution.Results indicated that the amorphous and semi-crystalline tri-magnesium phosphate powders were highly reactive with the setting solution but resulted in mechanically weak cements,while the crystalline tri-magnesium phosphate powder reacted efficiently with the cement solution and were mechanically strong following the cement reaction.X-ray diffraction and scanning electron microscopy analyses indicated significant changes in the phase composition and morphology of the cements following incubation in phosphate buffered saline.These were perceived to be detrimental to the integrity of the amorphous and semi-crystalline tri-magnesium phosphate derived cements but not to those created with fully crystalline tri-magnesium phosphate.The crystalline tri-magnesium phosphate material resulted in the most functional cement as this embodiment displayed the most clinically relevant setting time as well as the highest mechanical resilience and neutral pH during incubation in saline solution rendering them potentially viable as bone void fillers.
