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Oxalate regulates crystal-cell adhesion and macrophage metabolism via JPT2/PI3K/AKT signaling to promote the progression of kidney stones
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作者 Qianlin Song Chao Song +8 位作者 Xin Chen Yunhe Xiong Ziqi He Xiaozhe Su Jiawei Zhou Hu Ke Caitao Dong Wenbiao Liao Sixing Yang 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2024年第6期851-862,共12页
Oxalate is an organic dicarboxylic acid that is a common component of plant foods.The kidneys are essential organs for oxalate excretion,but excessive oxalates may induce kidney stones.Jupiter microtubule associated h... Oxalate is an organic dicarboxylic acid that is a common component of plant foods.The kidneys are essential organs for oxalate excretion,but excessive oxalates may induce kidney stones.Jupiter microtubule associated homolog 2(JPT2)is a critical molecule in Ca^(2+)mobilization,and its intrinsic mechanism in oxalate exposure and kidney stones remains unclear.This study aimed to reveal the mechanism of JPT2 in oxalate exposure and kidney stones.Genetic approaches were used to control JPT2 expression in cells and mice,and the JPT2 mechanism of action was analyzed using transcriptomics and untargeted metabolomics.The results showed that oxalate exposure triggered the upregulation of JPT2,which is involved in nicotinic acid adenine dinucleotide phosphate(NAADP)-mediated Ca^(2+)mobilization.Transcriptomic analysis revealed that cell adhesion and macrophage inflammatory polarization were inhibited by JPT2 knockdown,and these were dominated by phosphatidylinositol 3-kinase(PI3K)/AKT signaling,respectively.Untargeted metabolomics indicated that JPT2 knockdown inhibited the production of succinic acid semialdehyde(SSA)in macrophages.Furthermore,JPT2 deficiency in mice inhibited kidney stones mineralization.In conclusion,this study demonstrates that oxalate exposure facilitates kidney stones by promoting crystal-cell adhesion,and modulating macrophage metabolism and inflammatory polarization via JPT2/PI3K/AKT signaling. 展开更多
关键词 oxalate Kidney stones JPT2 Crystal-cell adhesion IMMUNOREGULATION
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Dimethylamine oxalate manipulating CsPbI_(3) perovskite film crystallization process for high efficiency carbon electrode based perovskite solar cells
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作者 Wenran Wang Xin Peng +7 位作者 Jianxin Zhang Jiage Lin Rong Huang Guizhi Zhang Huishi Guo Zhenxiao Pan Xinhua Zhong Huashang Rao 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期221-228,I0006,共9页
Crystallization process determines the quality of perovskite films and the performances of resultant perovskite solar cells(PSCs).Dimethylamine oxalate has been proven as a multifunctional modulator,and is explored as... Crystallization process determines the quality of perovskite films and the performances of resultant perovskite solar cells(PSCs).Dimethylamine oxalate has been proven as a multifunctional modulator,and is explored as an efficient additive in manipulating the crystallization process of CsPbI_(3) perovskite films.On one hand,oxalate serves as the precipitator that facilitates the nucleation process of intermediate.The larger size of intermediate is conductive to the larger size and smaller grain boundaries of resultant perovskite.On the other hand,in subsequent annealing process,the phase conversion and growth process of transient perovskite can be decelerated due to the strong interactions of oxalate with both dimethylamine cation(DMA^(+))and Pb^(2+).Due to the optimized crystallization kinetics,the morphology and quality of CsPbI_(3) perovskite films are comprehensively improved with lower defect concentrations,and charge recombination loss is effectively suppressed.Benefiting from the optimized crystal quality of perovskite films,the carbon electrode-based CsPbI_(3) PSCs exhibit a champion efficiency of 18.48%.This represents one of the highest levels among all hole transport layer-free inorganic perovskite solar cells. 展开更多
关键词 Solar cells PEROVSKITE CsPbI_(3) Carbon electrodes oxalate
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Tuning the product selectivity of dimethyl oxalate hydrogenation over WO_(x) modified Cu/SiO_(2) catalysts
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作者 Zheng Li Zhuo Ma +9 位作者 Yihui Li Ziang Zhao Yuan Tan Ziyin Liu Xingkun Chen Nian Lei Huigang Wang Wei Lu Hejun Zhu Yunjie Ding 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第10期128-138,I0004,共12页
Product selectivity and reaction pathway are highly dependent on surface structure of heterogeneous catalysts.For vapor-phase hydrogenation of dimethyl oxalate(DMO),"EG route"(DMO→methyl glycolate(MG)ethyle... Product selectivity and reaction pathway are highly dependent on surface structure of heterogeneous catalysts.For vapor-phase hydrogenation of dimethyl oxalate(DMO),"EG route"(DMO→methyl glycolate(MG)ethylene glycol(EG)→ethanol(ET))and"MA route"(DMO→MG→methyl acetate(MA))were proposed over traditional Cu based catalysts and Mo-based or Fe-based catalysts,respectively.Herein,tunable yield of ET(93.7%)and MA(72.1%)were obtained through different reaction routes over WO_(x) modified Cu/SiO_(2) catalysts,and the corresponding reaction route was further proved by kinetic study and in-situ DRIFTS technology.Mechanistic studies demonstrated that H_(2) activation ability,acid density and Cu-WO_(x) interaction on the catalysts were tuned by regulating the surface W density,which resulted in the different reaction pathway and product selectivity.What's more,high yield of MA produced from DMO hydrogenation was firstly reported with the H_(2) pressure as low as 0.5 MPa. 展开更多
关键词 ETHANOL Dimethyl oxalate Selective hydrogenation Methyl acetate WCu/SiO_(2)catalyst
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Severe acute kidney injury due to oxalate crystal induced severe interstitial nephritis:A case report
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作者 Maulik K Lathiya Praveen Errabelli +1 位作者 Sasmit Roy Neeharik Mareedu 《World Journal of Nephrology》 2024年第2期24-30,共7页
BACKGROUND Acute kidney injury(AKI)due to interstitial nephritis is a known condition primarily attributed to various medications.While medication-induced interstitial nephritis is common,occurrences due to non-pharma... BACKGROUND Acute kidney injury(AKI)due to interstitial nephritis is a known condition primarily attributed to various medications.While medication-induced interstitial nephritis is common,occurrences due to non-pharmacological factors are rare.This report presents a case of severe AKI triggered by intratubular oxalate crystal deposition,leading to interstitial nephritis.The aim is to outline the case and its management,emphasizing the significance of recognizing uncommon causes of interstitial nephritis.CASE SUMMARY A 71-year-old female presented with stroke-like symptoms,including weakness,speech difficulties,and cognitive impairment.Chronic hypertension had been managed with hydrochlorothiazide(HCTZ)for over two decades.Upon admis-sion,severe hypokalemia and AKI were noted,prompting discontinuation of HCTZ and initiation of prednisolone for acute interstitial nephritis.Further investigations,including kidney biopsy,confirmed severe acute interstitial nephritis with oxalate crystal deposits as the underlying cause.Despite treatment,initial renal function showed minimal improvement.However,with prednisolone therapy and supportive measures,her condition gradually improved,high-lighting the importance of comprehensive management.CONCLUSION This case underscores the importance of a thorough diagnostic approach in identifying and addressing uncommon causes of interstitial nephritis.The occurrence of interstitial nephritis due to oxalate crystal deposition,especially without typical risk factors,emphasizes the need for vigilance in clinical practice. 展开更多
关键词 Acute kidney injury Interstitial nephritis oxalate crystal HYDROCHLOROTHIAZIDE HYPOKALEMIA Case report
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Activation mechanism of ammonium oxalate with pyrite in the lime system and its response to flotation separation of pyrite from arsenopyrite 被引量:3
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作者 Runpeng Liao Shuming Wen +2 位作者 Qicheng Feng Jiushuai Deng Hao Lai 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第2期271-282,共12页
The activation properties of ammonium oxalate on the flotation of pyrite and arsenopyrite in the lime system were studied in this work.Single mineral flotation tests showed that the ammonium oxalate strongly activated... The activation properties of ammonium oxalate on the flotation of pyrite and arsenopyrite in the lime system were studied in this work.Single mineral flotation tests showed that the ammonium oxalate strongly activated pyrite in high alkalinity and high Ca^(2+)system,whereas arsenopyrite was almost unaffected.In mineral mixtures tests,the recovery difference between pyrite and arsenopyrite after adding ammonium oxalate is more than 85%.After ammonium oxalate and ethyl xanthate treatment,the hydrophobicity of pyrite increased significantly,and the contact angle increased from 66.62°to 75.15°and then to 81.21°.After ammonium oxalate treatment,the amount of ethyl xanthate adsorption on the pyrite surface significantly increased and was much greater than that on the arsenopyrite surface.Zeta potential measurements showed that after activation by ammonium oxalate,there was a shift in the zeta potential of pyrite to more negative values by adding xanthate.X-ray photoelectron spectroscopy test showed that after ammonium oxalate treatment,the O 1s content on the surface of pyrite decreased from 44.03%to 26.18%,and the S 2p content increased from 14.01%to 27.26%,which confirmed that the ammonium oxalatetreated pyrite surface was more hydrophobic than the untreated surface.Therefore,ammonium oxalate may be used as a selective activator of pyrite in the lime system,which achieves an efficient flotation separation of S-As sulfide ores under high alkalinity and high Ca2+concentration conditions. 展开更多
关键词 PYRITE ARSENOPYRITE ammonium oxalate flotation separation
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Clinical efficacy and safety of Guipi decoction combined with escitalopram oxalate tablets in patients with depression 被引量:1
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作者 Jia Yu Feng-Quan Xu 《World Journal of Clinical Cases》 SCIE 2023年第29期7017-7025,共9页
BACKGROUND Depression is a widespread mental health condition that requires effective treatment.In the treatment of depression,traditional Chinese medicine(TCM)offers obvious advantages,fewer adverse reactions,and a l... BACKGROUND Depression is a widespread mental health condition that requires effective treatment.In the treatment of depression,traditional Chinese medicine(TCM)offers obvious advantages,fewer adverse reactions,and a lower recurrence rate.AIM To evaluate the clinical benefits of Guipi decoction combined with escitalopram oxalate tablets for individuals with depression.METHODS In total,80 patients diagnosed as having depression were enrolled in the study and divided into either an experimental group or a control group.All of the patients were orally administered escitalopram oxalate tablets.Additionally,the experimental group received Jiajian Guipi decoction and reduced Governor vessel fumigation over 4 wk.TCM syndrome scores,Hamilton depression rating scale(HAM-D)scores,self-rating depression scale(SDS)scores,and Pittsburgh sleep quality index scores were measured for the two groups and compared before and after the treatment.The two groups were monitored for any adverse reactions.RESULTS After 4 wk of treatment,both groups exhibited a significant reduction in TCM syndrome scores compared with their pre-treatment scores(P<0.05).However,the experimental group exhibited significantly lower TCM syndrome scores than the control group(P<0.05).Similarly,the post-treatment SDS and HAM-D-24 scores were significantly lower in both groups than the pre-treatment scores(P<0.05),with the experimental group exhibiting lower scores than the control group(P<0.05).The total treatment efficiency was significantly better in the experimental group(97.14%)than in the control group(77.78%)(P<0.05).Furthermore,after 4 wk of treatment,the Pittsburgh sleep quality index scores for both groups were significantly lower than those before the treatment(P<0.05),with the experimental group exhibiting lower scores than the control group(P<0.05).The incidence of adverse reactions was significantly lower in the experimental group than in the control group(P<0.05).CONCLUSION The combination of Guipi decoction and escitalopram oxalate tablets was found to be an effective and safe treatment for depression.This combination could reduce TCM syndrome scores,improve depressive symptoms,and enhance sleep quality. 展开更多
关键词 Jiajian Guipi decoction Escitalopram oxalate tablets Depressive disorder Sleep quality Traditional Chinese medicine syndromes
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Proposal for pathogenesis-based treatment options to reduce calcium oxalate stone recurrence
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作者 Saeed R.Khan Benjamin K.Canales 《Asian Journal of Urology》 CSCD 2023年第3期246-257,共12页
Objective:Prevalence of kidney stone disease continues to increase globally with recurrence rates between 30%and 50%despite technological and scientific advances.Reduction in recurrence would improve patient outcomes ... Objective:Prevalence of kidney stone disease continues to increase globally with recurrence rates between 30%and 50%despite technological and scientific advances.Reduction in recurrence would improve patient outcomes and reduce cost and stone morbidities.Our objective was to review results of experimental studies performed to determine the efficacy of readily available compounds that can be used to prevent recurrence.Methods: All relevant literature up to October 2020,listed in PubMed is reviewed.Results: Clinical guidelines endorse the use of evidence-based medications,such as alkaline agents and thiazides,to reduce urinary mineral supersaturation and recurrence.However,there may be additional steps during stone pathogenesis where medications could moderate stone risk.Idiopathic calcium oxalate stones grow attached to Randall’s plaques or plugs.Results of clinical and experimental studies suggest involvement of reactive oxygen species and oxidative stress in the formation of both the plaques and plugs.The renin-angiotensin-aldosterone system(RAAS),nicotinamide adenine dinucleotide phosphate(NADPH)oxidase,mitochondria,and NOD-like receptor pyrin domain containing-3(NLRP3)inflammasome have all been implicated at specific steps during stone pathogenesis in animal models.Conclusion: In addition to supersaturation-reducing therapies,the use of anti-oxidants,free radical scavengers,and inhibitors of NADPH oxidase,NLRP3 inflammasome,and RAAS may prove beneficial for stone prevention.Compounds such as statins and angiotensin converting enzyme inhibitors are already in use as therapeutics for hypertension and cardio-vascular disease and have previously shown to reduce calcium oxalate nephrolithiasis in rats.Although clinical evidence for their use in stone prevention in humans is limited,experimental data support they be considered along with standard evidence-based medications and clinical expertise when patients are being counselled for stone prevention. 展开更多
关键词 Kidney stones Calcium oxalate Inflammation INFLAMMASOME SUPERSATURATION Reactive oxygen species Oxidative stress
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Kinetics of thermal decomposition of lanthanum oxalate hydrate 被引量:11
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作者 詹光 余军霞 +2 位作者 徐志高 周芳 池汝安 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第4期925-934,共10页
Lanthanum oxalate hydrate La2(C2O4)3·10H2O,the precursor of La2O3 ultrafine powders,was prepared by impinging stream reactor method with PEG 20000 as surfactant.Thermal decomposition of La2(C2O4)3·10H2O ... Lanthanum oxalate hydrate La2(C2O4)3·10H2O,the precursor of La2O3 ultrafine powders,was prepared by impinging stream reactor method with PEG 20000 as surfactant.Thermal decomposition of La2(C2O4)3·10H2O from room temperature to 900 °C was investigated and intermediates and final solid products were characterized by FTIR and DSC-TG.Results show that the thermal decomposition process consists of five consecutive stage reactions.Flynn-Wall-Ozawa(FWO) and Kissinger-Akahira-Sunose(KAS) methods were implemented for the calculation of energy of activation(E),and the results show that E depends on α,demonstrating that the decomposition reaction process of the lanthanum oxalate is of a complex kinetic mechanism.The most probable mechanistic function,G(α)=[1-(1+α)1/3]2,and the kinetic parameters were obtained by multivariate non-linear regression analysis method.The average E-value that is compatible with the kinetic model is close to value which was obtained by FWO and KAS methods.The fitting curve matches the original TG curve very well. 展开更多
关键词 lanthanum oxalate decahydrate TG-DSC thermal decomposition multivariate non-linear regression analysis
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Preparation of Diphenyl Oxalate from Transesterification of Dimethyl Oxalate with Phenol over TS-1 Catalyst 被引量:2
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作者 Xin Bin MA Sheng Ping WANG +1 位作者 Hong Li GUO Gen Hui XU 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第5期461-464,共4页
Diphenyl oxalate was synthesized from transesterification of dimethyl oxalate with phenol over TS-1 ( 2.5 wt% Ti ) catalyst. TS-1 catalyst, as a heterogeneous catalyst, showed excellent selectivity of diphenyl oxalat... Diphenyl oxalate was synthesized from transesterification of dimethyl oxalate with phenol over TS-1 ( 2.5 wt% Ti ) catalyst. TS-1 catalyst, as a heterogeneous catalyst, showed excellent selectivity of diphenyl oxalate and methylphenyl oxalate compared with other homogeneous catalysts. Lewis acid sites on TS-1 catalyst were the active sites for transesterification of dimethyl oxalate with phenol. The high selectivity was closely related to the weak acid sites over TS-1. 展开更多
关键词 Diphenyl oxalate TRANSESTERIFICATION dimethyl oxalate weak acid sites TS-1.
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Synthesis and Luminescence Property of Hierarchical Europium Oxalate Micropaticles
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作者 祝玮 张悠金 +1 位作者 何红梅 方智勇 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2011年第1期65-69,I0003,I0004,共7页
Hierarchical europium oxalate Eu2(C2O4)3.10H2O micro-particles were synthesized through a simple precipitation method at room temperature in present of trisodium citrate. The products were characterized by X-ray dif... Hierarchical europium oxalate Eu2(C2O4)3.10H2O micro-particles were synthesized through a simple precipitation method at room temperature in present of trisodium citrate. The products were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, and photoluminescence. The possible formation mechanism of the hierarchical europium oxalate Eu2(C2O4)3.10H2O micro-particles was discussed. 展开更多
关键词 HIERARCHY Europium oxalate Precipitation method PHOTOLUMINESCENCE
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Development of <i>α</i>-Amino Acid Detection with Peroxyoxalate Chemiluminescence by Using Water-Acetonitrile-Ethyl Acetate Mixed Solution
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作者 Hyo Kan Ryo Mizutani Kazuhiko Tsukagoshi 《American Journal of Analytical Chemistry》 2020年第1期15-24,共10页
Peroxyoxalate chemiluminescence was, for the first time, examined by using ternary mixed solutions of water-hydrophilic/hydrophobic organic solvent. Eosin Y as a model fluorescence compound was dissolved with the tern... Peroxyoxalate chemiluminescence was, for the first time, examined by using ternary mixed solutions of water-hydrophilic/hydrophobic organic solvent. Eosin Y as a model fluorescence compound was dissolved with the ternary solutions of water (1.0 mM carbonate buffer, pH 9.0)-acetonitrile-ethyl acetate, water-rich of 15:3:2 volume ratio and organic solvent-rich of 3:8:4 volume ratio, to which bis(2,4,6-trichlorophenyl) oxalate and hydrogen peroxide chemiluminescence reagent were added. The chemiluminescence observed with the ternary solutions, especially the organic solvent-rich solution, showed a larger signal than that observed with the water only solution or water-acetonitrile mixed solution. Chemiluminescence in the presence of twenty types of α-amino acid was similarly examined by using the ternary organic solvent-rich solution. The chemiluminescence of three α-amino acids with fluorescence properties was enhanced with the ternary solution. The data reported here may contribute to development of a new, sensitive peroxyoxalate chemiluminescence detection system. 展开更多
关键词 PEROXYoxalate chemiluminescence α-Amino Acids Water-Acetonitrile-Ethyl Acetate Bis(2 4 6-Trichlorophenyl) oxalate
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Synthesis of Methyl Glycolate by Hydrogenation of Dimethyl Oxalate over Cu-Ag/SiO_2 Catalyst 被引量:25
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作者 Baowei Wang Qian Xu Hua Song Genhui Xu 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2007年第1期78-80,共3页
Methyl glycolate is a good solvent and can be used as feedstock for the synthesis of some important organic chemicals. Catalytic hydrogenation of dimethyl oxalate (DMO) over copper-silver catalyst supported on silic... Methyl glycolate is a good solvent and can be used as feedstock for the synthesis of some important organic chemicals. Catalytic hydrogenation of dimethyl oxalate (DMO) over copper-silver catalyst supported on silica was studied. The Cu-Ag/SiO2 catalyst supported on silica sol was prepared by homogeneous deposition-precipitation of the mixture of aqueous euprammonia complex and silica sol. The proper active temperature of Cu-Ag/SiO2 catalyst for hydrogenation of DMO was 523-623 K. The most preferable reaction conditions for methyl glycolate (MG) were optimized: temperature at 468-478 K, 40-60 mesh catalyst diameter, H2/DMO ratio 40, and 1.0 h^-1 of LHSV. 展开更多
关键词 dimethyl oxalate methyl glycolate ethylene glycol HYDROGENATION Cu-Ag/SiO2 catalyst
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Effect of copper loading on texture,structure and catalytic performance of Cu/SiO_2 catalyst for hydrogenation of dimethyl oxalate to ethylene glycol 被引量:14
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作者 Bo Zhang Shengguo Hui +3 位作者 Suhua Zhang Yang Ji Wei Li Dingye Fang 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2012年第5期563-570,共8页
Cu/SiO2 catalysts prepared by a convenient and efficient method using the urea hydrolysis deposition-precipitation (UHDP) technique have been proposed focusing on the effect of copper loading.The texture,structure a... Cu/SiO2 catalysts prepared by a convenient and efficient method using the urea hydrolysis deposition-precipitation (UHDP) technique have been proposed focusing on the effect of copper loading.The texture,structure and composition are systematically characterized by ICP,FTIR,N 2-physisorption,N2O chemisorption,TPR,XRD and XPS.The formation of copper phyllosilicate is observed in Cu/SiO2 catalyst by adopting UHDP method,and the amount of copper phyllosilicate is related to copper loading.It is found the structure properties and catalytic performance is profoundly affected by the amount of copper phyllosilicate.The excellent catalytic activity is attributed to the synergetic effect between Cu0 and Cu +.DMO conversion and EG selectivity are determined by the amount of Cu0 and Cu+,respectively.The proper copper loading (30 wt%) provides with the highest ratio of Cu + /Cu0,giving rise to the highest EG yield of 95% under the reaction conditions of p=2.0 MPa,T=473 K,H2/DMO=80 and LHSV=1.0h-1. 展开更多
关键词 CU/SIO2 copper loading dimethyl oxalate ethylene glycol copper phyllosilicate
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Synthesis of Y_2O_3 Nano-Powder from Yttrium Oxalate under Ambient Temperature 被引量:9
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作者 李玲 《Journal of Rare Earths》 SCIE EI CAS CSCD 2005年第3期358-361,共4页
High purity Y_2O_3 nano-powders was synthesized directly from solution ofindustrial YCl_3 by method of oxalate precipitation through super-micro-reactors made by complexnon-ionic surfactant. The purity and diameter of... High purity Y_2O_3 nano-powders was synthesized directly from solution ofindustrial YCl_3 by method of oxalate precipitation through super-micro-reactors made by complexnon-ionic surfactant. The purity and diameter of Y_2O_3 particles were controlled by such processingparameters as concentration of YCl_3 and oxalic acid and complex non-ionic surfactant etc. TEMphotomicrographs show that Y_2O_3 particles are spherical in shape, with an average diameter of lessthan 30 nm. Test results certify that the purity and particle diameter as well as the dispersion ofY_2O_3 nano-powder depend on the concentrations of YCl_3, oxalic acid and complex non-ionicsurfactant. The optimum ranges of the concentrations for YCl_3 and complex non-ionic surfactant whenthe diameter of Y_2O_3 particles is smaller than 100 nm are 0.43 ~1.4 mol ? L^(-1) and0.031~0.112 mol·L^(-1) respectively, while the mass fraction range of oxalic acid is 10% ~18% .The purity of Y_2O_3 nano-powder tested by ICP-AES analysis is 99.99% . 展开更多
关键词 oxalate precipitation method complex non-ionic surfactant super-micro-reactor Y_2O_3 nano-powder synthesis rare earths
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Reaction kinetics and mechanism of calcium oxide in dilute sodium aluminate solution with oxalate based on lime causticization 被引量:7
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作者 Bai-yong ZHANG Xiao-lin PAN +2 位作者 Jiang-zhou WANG Hai-yan YU Gan-feng TU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第6期1312-1322,共11页
The formation kinetics and mechanism of tricalcium aluminate hydrate and calcium oxalate in dilute sodium aluminate solution and sodium oxalate solution were studied respectively based on the lime causticization, and ... The formation kinetics and mechanism of tricalcium aluminate hydrate and calcium oxalate in dilute sodium aluminate solution and sodium oxalate solution were studied respectively based on the lime causticization, and the optimal conditions for removing the oxalate in dilute sodium aluminate solution as well as the mechanism were finally obtained.The formation processes of tricalcium aluminate hydrate and calcium oxalate are mainly controlled by the chemical reaction and the inner diffusion respectively,and the corresponding reaction rate equations as well as the apparent activation energy were calculated. The hydrocalumite with a spatially interleaved structure will form in dilute sodium aluminate solution with sodium oxalate, greatly removing the oxalate impurity by absorption. Calcium oxalate can be converted to tricalcium aluminate hydrate with the increasing reaction time. The oxalate causticization efficiency and the alumina loss rate can be over 90% and below 31% respectively when reacted at 50℃ with a stirring rate of 200 r/min. 展开更多
关键词 Bayer process lime causticization oxalate KINETICS sodium aluminate solution
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Electrical Investigation of Some Silver Containing Ceramics Obtained from Coprecipitated Oxalates 被引量:24
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作者 M.I.El-Hofy(Physics Department, Faculty of Science, Menoufia University, Shebin El-Kom, Egypt)A.M.Donia(Chemistry Department, Faculty of Science, Menoufia University, Shebin El-Kom, Egypt)M.M.Abou-Sekkina(Chemistry Department, Faculty of Science, Taota Un 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1999年第1期87-90,共4页
Silver-ceramics (Ag2MO2)(M=Co, Ni, or Cu) were prepared through thermal decompositionof coprecipitated oxalates. Pellets of these materials were annealed at 350℃ for different timeperiods up to 5 h. The effect of ann... Silver-ceramics (Ag2MO2)(M=Co, Ni, or Cu) were prepared through thermal decompositionof coprecipitated oxalates. Pellets of these materials were annealed at 350℃ for different timeperiods up to 5 h. The effect of annealing time on the transport properties was studied. IR andX-ray spectra were also studied. 展开更多
关键词 CuO Figure Electrical Investigation of Some Silver Containing Ceramics Obtained from Coprecipitated oxalates
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Paired-Pd(Ⅱ) centers embedded in HKUST-1 framework: Tuning the selectivity from dimethyl carbonate to dimethyl oxalate 被引量:6
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作者 Hong-Zi Tan Zhe-Ning Chen +5 位作者 Kai-Qiang Jing Jing Sun Yu-Ping Xu Ning-Ning Zhang Zhong-Ning Xu Guo-Cong Guo 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第4期233-240,共8页
CO oxidative coupling to dimethyl oxalate(DMO) is the most crucial step in coal to ethylene glycol. Pdbased supported catalysts have been verified effective for generating DMO, but concomitant generation of dimethyl c... CO oxidative coupling to dimethyl oxalate(DMO) is the most crucial step in coal to ethylene glycol. Pdbased supported catalysts have been verified effective for generating DMO, but concomitant generation of dimethyl carbonate(DMC) is always unavoidable. It is generally accepted that Pd(0) is the active species for producing DMO, while Pd(II) for DMC. However, density functional theory calculations have proposed that the selectivity to DMO or DMC highly depends on the space state of Pd species rather than its oxidative state. It is thus urgently desired to develop high-efficient catalysts with well-defined structure,and further to elucidate the structure-performance relationship. In this work, HKUST-1 with unique structure of paired-Cu(Ⅱ) centers was chosen as ideal support to construct the catalysts with respective paired-Pd(Ⅱ) centers and isolated-Pd(Ⅱ) centers via in situ Pd species doping. In despite of featuring Pdδ+(δ≈2) oxidation state, the synthesized paired-Pd(Ⅱ)/HKUST-1 catalyst still exhibited DMO as dominant product(90.8% of DMO selectivity). For isolated-Pd(Ⅱ)/HKUST-1 catalyst, however, the main product was DMC(84.8% of DMC selectivity). Based on catalyst characterizations, the structures of paired-Pd(Ⅱ) centers and isolated-Pd(Ⅱ) centers were determined. DMO was generated from the coupling of adjacent *COOCH;intermediates adsorbed on paired-Pd(Ⅱ) centers, while DMC was produced from the reaction between methyl nitrite and the *COOCH;intermediates formed on isolated-Pd(Ⅱ) centers. Current work is the first MOFs-based catalyst with well-defined structure being applied in CO oxidative coupling reaction, which not only sheds light on the structure-performance relationship, but also inspires the potential of using MOFs as tunable platform to design high-efficient catalysts in heterogeneous catalysis. 展开更多
关键词 CO Methyl nitrite Oxidative coupling Dimethyl oxalate Paired-Pd(Ⅱ)centers HKUST-1
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Removal of iron from ilmenite by KOH leaching-oxalate leaching method 被引量:5
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作者 WANG Yuanbo QI Tao +1 位作者 CHU Jinglong ZHAO Wei 《Rare Metals》 SCIE EI CAS CSCD 2010年第1期9-15,共7页
Oxalic acid was used for the removal of iron from the intermediates of ilmenite leached by KOH liquor. Various parameters, such as pH, temperature, initial oxalate concentration, and illumination were investigated. Me... Oxalic acid was used for the removal of iron from the intermediates of ilmenite leached by KOH liquor. Various parameters, such as pH, temperature, initial oxalate concentration, and illumination were investigated. Meanwhile, it was found that orthorhombic crystal Ti2O2(OH)2(C2O4)-H2O formed as the leaching proceeded. Scanning electronic microscope (SEM) images implied that the formation of Ti2O2(OH)2(C2O4).H2O with good crystallinity proceeded through three stages. Calcining Ti2O2(OH)2(C2O4)·H2O, anatase (350℃) or mtile (550℃) type TiO2 was obtained, respectively. Element analysis found that the calcined product contained 94.9% TiO2 and 2.5% iron oxide, but only about 1600 ppm dissolvable iron oxide was left, which indicates that oxalic acid was comparatively effective on iron oxide removal from the intermediates. Finally, an improved route was proposed for the upgrading of ilmenite into mtile. 展开更多
关键词 ILMENITE iron removal titanium oxide oxalate potassium hydroxide KOH leaching
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Effects of synthesis conditions on the structural and electrochemical properties of layered LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 cathode material via oxalate co-precipitation method 被引量:6
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作者 TIAN Hua YE Naiqing +1 位作者 LIU Dan LI Wenqun 《Rare Metals》 SCIE EI CAS CSCD 2008年第6期575-579,共5页
The uniform layered LiNi1/3Co1/3Mn1/3O2 cathode material for lithium ion batteries was prepared by using (Ni1/3Co1/3Mn1/3)C2O4 as precursor synthesized via oxalate co-precipitation method in air. The effects of calc... The uniform layered LiNi1/3Co1/3Mn1/3O2 cathode material for lithium ion batteries was prepared by using (Ni1/3Co1/3Mn1/3)C2O4 as precursor synthesized via oxalate co-precipitation method in air. The effects of calcination temperature and time on the structure and electrochemical properties of the LiNi1/3Co1/3Mn1/3O2 were systemically studied. XRD results revealed that the optimal calcination conditions to prepare the layered LiNi1/3Co1/3Mn1/302 were 950℃ for 15 h. Electrochemical measurement showed that the sample prepared under the such conditions has the highest initial discharge capacity of 160.8 mAh/g and the smallest irreversible capacity loss of 13.5% as well as stable cycling performance at a constant current density of 30 mA/g between 2.5 and 4.3 V versus Li at room temperature. 展开更多
关键词 lithium ion batteries oxalate co-precipitation method cathode materials electrochemical performance
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Neuroprotective Effect of Escitalopram Oxalate in Rats with Chronic Hypoperfusion 被引量:5
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作者 马莉 卢祖能 +1 位作者 胡沛 姚长江 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2015年第4期514-518,共5页
Summary: The neuroproteetive effects of escitalopram oxalate in rats with chronic hypoperfusion and the possible mechanism were explored. Chronic hypoperfusion (2-VO) model was prepared and given escitalopram oxala... Summary: The neuroproteetive effects of escitalopram oxalate in rats with chronic hypoperfusion and the possible mechanism were explored. Chronic hypoperfusion (2-VO) model was prepared and given escitalopram oxalate (experimental group) or PBS (control group) after 6 weeks. Eight weeks after the operation, Morris water maze test was carried out to evaluate the learning and memory ability of the rats. The cell proliferation, three-dimensional vascular distribution, cell morphological changes in ischemic area and the plasma vascular endothelial growth factor (VEGF) were detected to explore the possible mechanisms. (1) Morris water maze test showed that the escape latency in the experimental group was significantly shorter than in the control group, while the first quadrant swimming time in the experi- mental group was significantly longer than the control group (both P〈0.01). (2) Cerebrovascular confo- cal detection results showed that the inside diameter of capillaries was significantly less in the experi- mental group than in the control group; the vascular density was significantly increased in the experi- mental group and the total area of capillaries was also significantly increased in the experimental group as compared with the control group. (3) There was statistically significant difference in BrdU-positive cells in the ischemic brain tissue between the experimental group and the control group (P=0.003〈0.01). (4) VEGF concentrations in the plasma and the ischemic area were higher in the experimental group than in the control group (P〈0.05). It was concluded that escitalopram oxalate could significantly im- prove the learning and memory ability of the rats with chronic cerebral ischemia probably by the VEGF-mediated angiogenesis. 展开更多
关键词 escitalopram oxalate chronic hypoperfusion NEUROPROTECTION MECHANISM vascular endo- thelial growth factor
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