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Leaching behavior of metals from limonitic laterite ore by high pressure acid leaching 被引量:14
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作者 郭学益 石文堂 +1 位作者 李栋 田庆华 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第1期191-195,共5页
The leaching behavior of metals from a nickeliferous limonitic laterite ore was investigated by high pressure acid leaching process for the extraction of nickel and cobalt.The effects of sulfuric acid added,leaching t... The leaching behavior of metals from a nickeliferous limonitic laterite ore was investigated by high pressure acid leaching process for the extraction of nickel and cobalt.The effects of sulfuric acid added,leaching temperature,leaching time and liquid/solid(L/S) ratio on metals extraction were examined.More than 97% Ni,96% Co,93% Mn,95% Mg and less than 1% Fe are extracted under optimum conditions.Analysis of the high pressure acid leaching residue by chemical and XRD analysis indicates that the residual iron and sulfur are mainly present in phases of hematite and alunite,respectively.The high pressure leaching process provides a simple and efficient way for the high recovery of nickel and cobalt from laterite ore,leaving residue as a suitable iron resource. 展开更多
关键词 high pressure acid leaching limonitic laterite leaching behavior NICKEL
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φ-pH diagram of V-Ti-H_2O system during pressure acid leaching of converter slag containing vanadium and titanium 被引量:4
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作者 牟望重 张廷安 +2 位作者 豆志河 吕国志 刘燕 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第9期2078-2086,共9页
To analyze the thermodynamic characteristics of leaching process of converter slag, φ-pH diagram of V-Ti-H2O system at oxygen partial pressure of 0.5 MPa, ionic mass concentration of 0.1 mol/kg and temperatures rangi... To analyze the thermodynamic characteristics of leaching process of converter slag, φ-pH diagram of V-Ti-H2O system at oxygen partial pressure of 0.5 MPa, ionic mass concentration of 0.1 mol/kg and temperatures ranging from 60 to 200 ℃ was obtained by recently published critically assessed standard Gibbs energies and activity coefficients of various species. When pH2, stable regions of V3+, VO2+ and VO2+ exist in the stable region of TiO2. The pH values of stable regions of vanadium and titanium decrease and redox potentials become more positive with the temperature increasing. Vanadium and titanium could be separated by one-step leaching based on thermodynamics. The experiment results of pressure acid leaching of converter slag show that leaching rates of vanadium and titanium are 96.87% and 8.76% respectively, at 140 ℃ of temperature, 0.5 MPa of oxygen partial pressure, 0.055-0.075mm of particle size, 15:1 of liquid to solid ratio, 120 min of leaching time, 500 r/min of stirring speed and 200 g/L of initial acid concentration. Vanadium and titanium could be selectively separated in the pressure acid leaching process, and the experiment result is in agreement with thermodynamic calculation result. 展开更多
关键词 φ-pH diagram V-Ti-H2O system pressure acid leaching converter slag VANADIUM titanium
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Changes of Amino Acid Content in Leaves of Agropyron cristatum Under Grazing Pressure
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作者 秀花 《Agricultural Science & Technology》 CAS 2014年第12期2069-2073,2077,共6页
By measuring and comparing the contents of amino acids in Agropyron cristatum under grazing pressure, this study showed that the contents of total and each of the amino acids in A. cristatum changed little under grazi... By measuring and comparing the contents of amino acids in Agropyron cristatum under grazing pressure, this study showed that the contents of total and each of the amino acids in A. cristatum changed little under grazing pressure. How- ever, the contents of free glycine (Gly) and proline (Pro) were very sensitive to grazing. Glycine content in grazing population was higher than that in non-grazing population at flowering stage; the content of free proline in non-grazing population was higher than that in grazing population at tillering, heading and especially flower- ing stage; the content of free proline under grazing pressure at maturity stage was higher than that of non-grazing population. 展开更多
关键词 Grazing pressure Agropyron cristatum Total amino acid Free amino acid
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Extracting vanadium from stone-coal by oxygen pressure acid leaching and solvent extraction 被引量:16
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作者 邓志敢 魏昶 +3 位作者 樊刚 李旻廷 李存兄 李兴彬 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第S1期118-122,共5页
Vanadium extraction from stone-coal was investigated by oxygen pressure acid leaching and solvent extraction.The mineralogy of the stone-coal from Tongren City of Guizhou Province,China,was investigated by various det... Vanadium extraction from stone-coal was investigated by oxygen pressure acid leaching and solvent extraction.The mineralogy of the stone-coal from Tongren City of Guizhou Province,China,was investigated by various determination methods. The effects of leaching time,leaching temperature,leaching agent concentration,leaching L/S ratio,granularity of material,additive consumption were investigated based on the mineralogy.The results show that under the conditions of leaching time of 3-4 h, temperature of 150℃,sulfuric acid consumption of 25%?30%,ratio of liquid to solid of 1.2:1,the granularity less than 0.074 mm, additive consumption of 3%-5%,and oxygen pressure of 1.2 MPa,and the vanadium leaching rate can be more than 92%by the method of two-step pressurized acid leaching.The powdery V2O5 product with 99.52%in V2O5 content is obtained by the flowsheet of acid recovery,removing iron by reduction process,solvent extraction,precipitating vanadium with ammonium water,and pyrolysis from the stone-coal oxygen pressure acid-leaching solution.The total recovery efficiency of vanadium is above 85%,which is more than 20%higher than that obtained in the conventional process.Furthermore,the new process does not cause air pollution since no HCl or Cl2 is released by calcination of the raw material. 展开更多
关键词 stone-coal extracting vanadium oxygen pressure acid leaching acid recovery solvent extraction
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Extraction of vanadium from vanadium slag by high pressure oxidative acid leaching 被引量:12
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作者 Guo-quan Zhang Ting-an Zhang +3 位作者 Guo-zhi Lü Ying Zhang Yan Liu Zhuo-lin Liu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2015年第1期21-26,共6页
To extract vanadium in an environment friendly manner, this study focuses on the process of leaching vanadium from vanadium slag by high pressure oxidative acid leaching. Characterizations of the raw slag, mineralogy ... To extract vanadium in an environment friendly manner, this study focuses on the process of leaching vanadium from vanadium slag by high pressure oxidative acid leaching. Characterizations of the raw slag, mineralogy transformation, and the form of leach residues were made by X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The result shows that the vana-dium slag is composed of major phases of fayalite, titanomagnetite, and spinel. During the high pressure oxidative acid leaching process, the fayalite and spinel phases are gradually decomposed by sulfuric acid, causing the release of vanadium and iron in the solution. Meanwhile, unreacted silicon and titanium are enriched in the leach residues. With the initial concentration of sulfuric acid at 250 g·L^-1, a leaching tem-perature of 140℃, a leaching time of 50 min, a liquid-solid ratio of 10:1 mL·g^-1, and oxygen pressure at 0.2 MPa, the leaching rate of vana-dium reaches 97.69%. 展开更多
关键词 EXTRACTION VANADIUM SLAG pressure leaching sulfuric acid MINERALOGY
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Pressure acid leaching of zinc sulfide concentrate 被引量:5
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作者 古岩 张廷安 +4 位作者 刘燕 牟望重 张伟光 豆志河 蒋孝丽 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第S1期136-140,共5页
Effects of particle size of the zinc sulfide concentrate,leaching temperature,solid-to-liquid ratio and additive amount on pressure acid leaching process of the zinc sulfide concentrate were studied.The results indica... Effects of particle size of the zinc sulfide concentrate,leaching temperature,solid-to-liquid ratio and additive amount on pressure acid leaching process of the zinc sulfide concentrate were studied.The results indicate that the additive can improve the reaction kinetics and the conversion rate.And sulfur can be successfully separated from the zinc sulfide concentrate as elemental sulfur.The reasonable experiment parameters are obtained as follows:the leaching temperature 150℃,oxygen partial pressure 1 MPa,additive amount 1%,solid-to-liquid ratio 1:4,leaching time 2 h,initial sulfuric acid concentration 15%,and particle size less than 44μm.Under the optimum conditions,the leaching rate of the zinc can reach 95%and the reduction rate of the sulfur can reach 90%. 展开更多
关键词 zinc sulfide concentrate pressure acid leaching ZINC SULFUR
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An investigation of oxygen pressure acid leaching of Gacun complex Cu-Pb bulk concentrate 被引量:6
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作者 Xu, Bin Zhong, Hong Jiang, Tao 《Rare Metals》 SCIE EI CAS CSCD 2012年第1期96-101,共6页
The treatment of the Gacun complex Cu-Pb bulk concentrate with high Zn,Ag,etc.,by oxygen pressure acid leaching was studied.The pri-mary copper and leadminerals in the concentrate are tetrahedrite and galena.The treat... The treatment of the Gacun complex Cu-Pb bulk concentrate with high Zn,Ag,etc.,by oxygen pressure acid leaching was studied.The pri-mary copper and leadminerals in the concentrate are tetrahedrite and galena.The treatment of tetrahedrite was rarely studied,and most of silver occurred in themineral too.The optimum operating parameters of oxygen pressure acid leaching were established by conditional tests.Under these parameters,the result of pilot scale test showed that the leaching percentages of copper and zinc were separately as high as 98.9 wt.% and 94.9 wt.%,while lead and silver were transformed into sulfate and sulfide precipitations,respectively.The copper and zinc in lixivium were reclaimed by extraction-electrowinning and purification-electrowinning,respectively,and the lead and silver in the residue were reclaimed separately by carbonate transformation-silicofluoric acid leaching and thiourea leaching. 展开更多
关键词 nonferrous metallurgy synthetic reclaiming oxygen pressure acid leaching complex Cu-Pb bulk concentrate TETRAHEDRITE
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Pressure leaching of zinc silicate ore in sulfuric acid medium 被引量:11
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作者 李存兄 徐红胜 +3 位作者 邓志敢 李兴彬 李旻廷 魏昶 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第5期918-923,共6页
Zinc silicate ore was characterized mineralogically and the results showed that zinc exists mainly as hemimorphite and smithsonite in the sample.Sulfuric acid pressure leaching of zinc silicate ore was carried out to ... Zinc silicate ore was characterized mineralogically and the results showed that zinc exists mainly as hemimorphite and smithsonite in the sample.Sulfuric acid pressure leaching of zinc silicate ore was carried out to assess the effect of particle size,sulfuric acid concentration,pressure,reaction time and temperature on the extraction of zinc and the dissolution of silica.Under the optimum conditions employed,up to 99.25% of zinc extraction and 0.20% silica dissolution are obtained.The main minerals in leaching residue are quartz and small amounts of undissolved oxide minerals of iron,lead and aluminum are associated with quartz. 展开更多
关键词 zinc silicate ore sulfuric acid pressure leaching extraction of zinc dissolution of silica
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Microwave pretreatment for enhanced selective nitric acid pressure leaching of limonitic laterite 被引量:6
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作者 HE Fei MABao-zhong +5 位作者 WANG Cheng-yan MAYu-tian ASSELIN Edouard CHEN Yong-qiang ZHANGWen-juan ZHAO Jian 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第10期3050-3060,共11页
As clean energy,the microwave is commonly used to pretreat various ores.In this work,the microwave dielectric properties of limonitic laterite ore were measured by resonant cavity perturbation technique and the effect... As clean energy,the microwave is commonly used to pretreat various ores.In this work,the microwave dielectric properties of limonitic laterite ore were measured by resonant cavity perturbation technique and the effects from microwave were systematically investigated.Results indicated that limonitic laterite had high microwave absorbance.After microwave pretreatment,the microstructure of the laterite became less aggregated and more porous and the main phase transformed from goethite to hematite that improved leaching in nitric acid(1.2 kg HNO3/kg ore);Ni,Co,Fe,and Mg extraction ratios were 95.2%,98.1%,1.8%and 15%,respectively,after leaching for 60 min at 200°C and 500 r/min.Furthermore,in the process of goethite to hematite by microwave pretreatment,the nickel-containing mineral is activated,which makes nickel be leached easily.The leaching process has high Ni extraction ratio compared to that without microwave(82%)and conventional pretreatment(90.4%).Therefore,microwave pretreatment of limonitic laterite before nitric acid pressure leaching is an effective way to improve the selectivity and extraction of the leach. 展开更多
关键词 limonitic laterite ore microwave pretreatment nitric acid pressure leaching NI CO
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Pressure acid leaching of black shale for extraction of vanadium 被引量:2
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作者 李旻廷 魏昶 +3 位作者 樊刚 李存兄 邓志敢 李兴彬 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第S1期112-117,共6页
Extraction of vanadium from black shale was attempted in pressure acid leaching.The chemical components of the sample obtained from Guizhou Province of China show that it contains 3.258%V2O5,52.880%SiO2 and 16.140%Al2... Extraction of vanadium from black shale was attempted in pressure acid leaching.The chemical components of the sample obtained from Guizhou Province of China show that it contains 3.258%V2O5,52.880%SiO2 and 16.140%Al2O3.Phase analyses of vanadium indicates vanadium mainly exists in the free oxide and mica.Vanadium contents in the two phases are 18%and 53%, respectively.The contents of V3 +,V 4+and V 5+are almost equal.Under the optimum parameters of one-step leaching(reaction time of 3 h,sulfuric addition of 25%,temperature of 150℃,liquid to solid ratio of 1.2 mL/g,catalyst(FeSO4)addition of 5%and size of 85%particle 0.074 mm),about 77%of vanadium is recovered.After two-step countercurrent leaching,the leach recovery of vanadium can reach above 90%.Air replacing oxygen is completely feasible.The impurity metals can dissolve into solution in different degrees. 展开更多
关键词 pressure acid leaching black shale VANADIUM CATALYST
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Utilizing Instilling Negative Pressure Wound Therapy with Vashe Wound Solution for an Infected Sternal Dehiscence: A Case Report
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作者 Linnea T. Mauro Courtney M. Janowski +5 位作者 Mariah J. Janowski Adalberto C. Gonzalez Eugene J. Sidoti Luis G. Fernandez Paul J. Kim Marc R. Matthews 《Surgical Science》 2023年第3期231-239,共9页
Utilization of negative pressure wound therapy with instillation (NPWTi) for sternal dehiscence wounds secondary to sternal wound infection after surgery has become an accepted therapy. NPWTi accelerates wound healing... Utilization of negative pressure wound therapy with instillation (NPWTi) for sternal dehiscence wounds secondary to sternal wound infection after surgery has become an accepted therapy. NPWTi accelerates wound healing through macrostrain, microstrain, and cyclic fluid instillation. Wounds benefit from additional superficial infection control with the removal of microorganisms, the release of proinflammatory mediators, stimulation of angiogenesis, as well as mechanical debridement. However, very few cases of utilizing NPWTi in the treatment of sternal wound infections have been reported in the literature. This case study describes the use of NPWTi with hypochlorous acid for the treatment of a sternal wound infection. 展开更多
关键词 Negative pressure Wound Therapy with Instillation NPWT NPWTi NPWT with Dwell Hypochlorous acid Vashe Wound Solution Sternal Dehiscence
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Relationship between Obesity, Serum Uric Acid, Serum Potassium and Glomerular Filtration Rate with Electric Left Ventricular Hypertrophy in Blacks Central Africans with High Blood Pressure 被引量:1
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作者 Bertrand Fikahem Ellenga Mbolla Paul Macaire Ossou Nguiet +6 位作者 Richard Loumingou Meo Stéphane Ikama Narcisse Ngangoue Thierry Raoul Gombet Henri Germain Monabeka Benjamn Longo Mbenza Gisèle Kimbally Kaky 《World Journal of Cardiovascular Diseases》 2018年第4期248-255,共8页
The authors conducted a retrospective study over a period of 6 months in a hypertensive population in order to determine the correlation between serum uric acid on glomerular filtration rate (GFR) and estimated serum ... The authors conducted a retrospective study over a period of 6 months in a hypertensive population in order to determine the correlation between serum uric acid on glomerular filtration rate (GFR) and estimated serum potassium with left ventricular hypertrophy (LVH) and obesity. This study enrolled 122 patients including 63 women (51.6%). The mean age was 55.9 ± 10.6 years (range 30 to 74 years). Obesity weight was found in 38 cases (31.1%) of which 20?were men (33.9%) and 18 women (28.6%). Abdominal obesity was found in 104 cases (85.2%). The average serum uric acid in patients with obesity weight was 63.3 ± 18.9 mg/L vs 62.4 ± 14.2 mg/L for no-obese patients (p?= 0.63). The average serum potassium in obese patients was 4.06 ± 0.42 mEq/L vs 4.02 ± 0.46 mEq/L for no-obese (p?= 0.65). The average GFR was 73.4 ± 21.4 ml/L in obese patients vs 66.6 ± 22.6 ml/min in no-obese (p?= 0.03). The LVH was found in 81 cases (66.4%). The LVH was found in 65 (62.5%) obese patients vs?16 (88%) non-obese patients (OR = 4.8, 95% 1.04?-?22?p?= 0.02). Only abdominal?obesity has been correlated with left ventricular hypertrophy after multivariate analysis. Emphasis must be focused on public health actions for effective and appropriate measures against obesity and hypertension, whose prevalence is increasing in our region. 展开更多
关键词 OBESITY High Blood pressure Glomerular FILTRATION Rate Uric acid SERUM POTASSIUM Black AFRICAN
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Effect of H_(2)S content on relative permeability and capillary pressure characteristics of acid gas/brine/rock systems:A review 被引量:1
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作者 Xiaoyan Zhang Qi Li +2 位作者 Mathias Simon Guodong Zheng Yongsheng Tan 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2022年第6期2003-2033,共31页
Geological storage of acid gas has been identified as a promising approach to reduce atmospheric carbon dioxide(CO_(2)),hydrogen sulfide(H_(2)S)and alleviate public concern resulting from the sour gas production.A goo... Geological storage of acid gas has been identified as a promising approach to reduce atmospheric carbon dioxide(CO_(2)),hydrogen sulfide(H_(2)S)and alleviate public concern resulting from the sour gas production.A good understanding of the relative permeability and capillary pressure characteristics is crucial to predict the process of acid gas injection and migration.The prediction of injection and redistribution of acid gas is important to determine storage capacity,formation pressure,plume extent,shape,and leakage potential.Herein,the existing experimental data and theoretical models were reviewed to gain a better understanding of the issue how the H_(2)S content affects gas density,gas viscosity,interfacial tension,wettability,relative permeability and capillary pressure characteristics of acid gas/brine/rock systems.The densities and viscosities of the acid gas with different H_(2)S mole fractions are both temperature-and pressure-dependent,which vary among the gas,liquid and supercritical phases.Water/acid gas interfacial tension decreases strongly with increasing H_(2)S content.For mica and clean quartz,water contact angle increases with increasing H_(2)S mole fraction.In particular,wettability reversal of mica to a H_(2)S-wet behavior occurs in the presence of dense H_(2)S.The capillary pressure increases with decreasing contact angle.At a given saturation,the relative permeability of a fluid is higher when the fluid is nonwetting.The capillary pressure decreases with decreasing interfacial tension at a given saturation.However,the existing datasets do not show a consistent link between capillary number and relative permeability.The capillary pressure decreases with increasing H_(2)S mole fraction.However,there is no consensus on the effect of the H_(2)S content on the relative permeability curves.This may be due to the limited availability of the relative permeability and capillary pressure data for acid gas/brine/rock systems;thus,more experimental measurements are required. 展开更多
关键词 acid gas geological sequestration Relative permeability Capillary pressure H_(2)S content Wettability Interfacial tension
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VPD modifies CO_(2) fertilization effect on tomato plants via abscisic acid and jasmonic acid signaling pathways
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作者 Dalong Zhang Huihua Yang +5 位作者 Xiaolu Chen Yan Li Yunzhou Li Hongye Liu Xulin Wu Min Wei 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第5期1165-1176,共12页
Atmospheric CO_(2)concentration is elevated globally,which has“CO_(2)fertilization effects”and potentially improves plant photosynthesis,yield,and productivity.Despite the beneficial effect of CO_(2)fertilization be... Atmospheric CO_(2)concentration is elevated globally,which has“CO_(2)fertilization effects”and potentially improves plant photosynthesis,yield,and productivity.Despite the beneficial effect of CO_(2)fertilization being modulated by vapor pressure deficit(VPD),the underlying mechanism is highly uncertain.In the present study,the potential roles of hormones in determining CO_(2)fertilization effects under contrasting high and low VPD conditions were investigated by integrated physiological and transcriptomic analyses.Beneficial CO_(2)fertilization effects were offset under high VPD conditions and were constrained by plant water stress and photosynthetic CO_(2)utilization.High VPD induced a large passive water driving force,which disrupted the water balance and consequently caused plant water deficit.Leaf water potential,turgor pressure,and hydraulic conductance declined under high VPD stress.The physiological evidence combined with transcriptomic analyses demonstrated that abscisic acid(ABA)and jasmonic acid(JA)potentially acted as drought-signaling molecules in response to high VPD stress.Increased foliar ABA and JA content triggered stomatal closure to prevent excessive water loss under high VPD stress,which simultaneously increased the diffusion resistance for CO_(2)uptake from atmosphere to leaf intercellular space.High VPD also significantly increased mesophyll resistance for CO_(2)transport from stomatal cavity to fixation site inside chloroplast.The chloroplast“sink”CO_(2)availability was constrained by stomatal and mesophyll resistance under high VPD stress,despite the atmospheric“source”CO_(2)concentration being elevated.Thus,ABA-and JA-mediated drought-resistant mechanisms potentially modified the beneficial effect of CO_(2)fertilization on photosynthesis,plant growth,and yield productivity.This study provides valuable information for improving the utilization efficiency of CO_(2)fertilization and a better understanding of the physiological processes. 展开更多
关键词 Abscisic acid CO_(2) fertilization Jasmonic acid Mesophyll conductance Stomatal conductance Vapor pressure deficit
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Synthesis and Properties of Lactic Acid-based Cross-linked Poly(ester-amide)
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作者 Yue Ying HE Cong Ming XIAO 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第5期645-648,共4页
A novel lactic acid-based cross-linked poly(ester-amide) (LCPEA) was synthesized. The gel fraction of the LCPEA could be modulated by the reaction conditions and it affected the mechanical and thermal properties o... A novel lactic acid-based cross-linked poly(ester-amide) (LCPEA) was synthesized. The gel fraction of the LCPEA could be modulated by the reaction conditions and it affected the mechanical and thermal properties of the LCPEA. The tensile strength, elastic modulus and bend strength of the LCPEA of 65% gel fraction were 4.65, 136.55 and 39.63 MPa, respectively. The thermal decomposition temperature (50 wt%) of the LCPEA was around 410℃. 展开更多
关键词 Lactic acid cross-linked poly(ester-amide) SYNTHESIS properties.
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Pressured Microwave-assisted Hydrolysis of Crude Glycyrrhizic Acid for Preparation of Glycyrrhetinic Acid
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作者 王仁敏 林婵 +3 位作者 刘晶靓 余方 高建培 潘学军 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2012年第1期152-157,共6页
A pressured microwave-assisted hydrolysis (PMAH) technique has been developed for hydrolyzing the crude glycyrrhizic acid (GA) extracted from licorice root to prepare glycyrrhetinic acid (GRA). In order to optim... A pressured microwave-assisted hydrolysis (PMAH) technique has been developed for hydrolyzing the crude glycyrrhizic acid (GA) extracted from licorice root to prepare glycyrrhetinic acid (GRA). In order to optimize the efficiency of PMAH, several experimental parameters were investigated, including liquid-solid ratio, hydrolysis time, sulfuric acid concentration and hydrolysis temperature. The optimized hydrolysis conditions were as follows:pressured microwave-assisted hydrolysis of crude GA for 21 min (taking 15 min to reach 150 ℃, and holding it for 6 rain) at 150 ℃ (at a radiation power of 450 W) in 3%-5% sulfuric acid solution with the liquid-solid (ml.g-1 crude GA) ratio of 25 : 1. As a result of the considerable saving in time and higher product yields (up to 90%), PMAH was proved more effective than conventional methods. 展开更多
关键词 glycyrrhetinic acid glycyrrhizic acid licorice root pressured microwave-assisted hydrolysis highperformance liquid chromatography
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Relationship between Mean Arterial Pressure, Uric Acid and Calcium with Xanthine Oxidase Activity and Fetal Outcome in Normotensive and Preeclampsia in a Nested Study
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作者 Ranjeeta Gadde Dayanand Chikkanayakanahalli Doddaiah Sheela Shimoga Rangappa 《Open Journal of Obstetrics and Gynecology》 2018年第14期1532-1548,共17页
Preeclampsia is a pregnancy complication;early identification with increased risk is one of the key goals in obstetrics. In a nested case control study, serum uric acid and calcium measured in first and second trimest... Preeclampsia is a pregnancy complication;early identification with increased risk is one of the key goals in obstetrics. In a nested case control study, serum uric acid and calcium measured in first and second trimesters of pregnancy were correlated with Xanthine oxidase (XO) activity, mean arterial pressure (MAP) and fetal birth weight. The mean ± SD of uric acid (2.01 ± 0.85, 4.8 ± 1.93), calcium (10.88 ± 1.97, 9.72 ± 2.04), MAP (84.32 ± 6.71, 78.40 ± 8.53) and XO activity (11.96 ± 1.91, 14.05 ± 3.09) of the study group (n=86) were observed in the first and second trimesters respectively. First trimester normotensive group (n=79) and preeclampsia cases (n = 7), showed a mean ± SD of uric acid (1.93 ± 0.80, 2.9 ± 0.88), Calcium (10.92 ± 1.9, 10.6 ± 1.72), MAP (84.19 ± 6.75, 85.71 ± 6.58) XO activity (11.82 ± 1.83, 13.57 ± 2.21). In the second trimester, normotensive group and preeclampsia cases showed a mean ± SD uric acid (4.6 ± 1.75, 7.3 ± 2.19), Calcium (9.4 ± 1.85, 12.9 ± 1.04), MAP (76.41 ± 5.41, 100.95 ± 2.52) and XO activity (13.37 ± 1.93, 21.70 ± 3.50). Statistical analysis revealed a non-significant positive correlation in first trimester between uric acid and MAP (r = +0.116, p = 0.288), negative correlations between uric acid and fetal birth weight (r = -0.118, 0.279) and between calcium and MAP (r =?-0.288, p = 0.007). In the second trimester, significant positive correlations were observed between uric acid (r = +0.246, p = 0.022), calcium (r = +0.326, p = 0.007) with MAP along with a significant negative correlation between uric acid (r = -0.641, p = 0.000), calcium (r = -0.316, p = 0.003), Proteinuria (r = -0.514, p = 0.000) with fetal birth weight. The screening of first and second trimesters XO activity, uric acid, calcium and MAP during pregnancy is beneficial in identifying women likely to develop preeclampsia with poor fetal outcome. 展开更多
关键词 Uric acid Mean ARTERIAL pressure PREECLAMPSIA Nested CASE-CONTROL FETAL Outcome
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Oxygen pressure acid leaching of Gacun complex Cu concentrates
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作者 XU Bin ZHONG Hong JIANG Tao 《Journal of Central South University》 SCIE EI CAS 2012年第1期71-76,共6页
The treatment of the Gacun complex Cu concentrate with high contents of Pb,Zn,Ag,etc by oxygen pressure acid leaching was studied.It is unusual that tetrahedrite,whose treatment was rarely studied,is the primary coppe... The treatment of the Gacun complex Cu concentrate with high contents of Pb,Zn,Ag,etc by oxygen pressure acid leaching was studied.It is unusual that tetrahedrite,whose treatment was rarely studied,is the primary copper mineral of the concentrates.Most of silver also occurs in the mineral.The optimum operating parameters of oxygen pressure acid leaching were established by conditional tests.Pilot scale test was carried out under the parameters,and the leaching rates of copper and zinc are as high as 97.10% and 89.83% while lead and silver are transformed into sulfate and sulfide respectively and stay in leaching residue.The copper and zinc in lixivium were reclaimed by extraction-electrowinning and purification-electrowinning,respectively,and the lead and silver in the residue were reclaimed separately by chloride leaching and thiourea leaching.The extraction rate of copper achieves 96%,and the leaching rates of lead and silver reach 90% and 95%,respectively. 展开更多
关键词 complex Cu concentrates oxygen pressure acid leaching synthetic reclaiming TETRAHEDRITE
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Establishment of probabilistic model for Salmonella Enteritidis growth and inactivation under acid and osmotic pressure
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作者 Yujiao Shi Hong Liu +4 位作者 Baozhang Luo Yangtai Liu Siyuan Yue Qing Liu Qingli Dong 《Food Science and Human Wellness》 SCIE 2017年第4期176-186,共11页
The growth and survival characteristic of Salmonella Enteritidis under acidic and osmotic conditions were studied.Meanwhile,a probabilistic model based on the theory of cell division and mortality was established to p... The growth and survival characteristic of Salmonella Enteritidis under acidic and osmotic conditions were studied.Meanwhile,a probabilistic model based on the theory of cell division and mortality was established to predict the growth or inactivation of S.Enteritidis.The experimental results demonstrated that the growth curves of planktonic and detached cells showed a significant difference(p<0.05)under four conditions,including pH5.0+0.0%NaCl,pH7.0+4.0%NaCl,pH6.0+4.0%NaCl,and pH5.0+4.0%NaCl.And the established primary and secondary models could describe the growth of S.enteritis well by estimating four mathematics evaluation indexes,including determination coefficient(R2),root mean square error(RMSE),accuracy factor(Af)and bias factor(Bf).Moreover,sequential treatment of 15%NaCl stress followed by pH 4.5 stress was the best condition to inactivate S.Enteritidis in 10 h at 25◦C.The probabilistic model with Logistical or Weibullian form could also predict the inactivation of S.Enteritidis well,thus realize the unification of predictive model to some extent or generalization of inactivation model.Furthermore,the primary 4-parameter probabilistic model or generalized inactivation model had slightly higher applicability and reliability to describe the growth or inactivation of S.Enteritidis than Baranyi model or exponential inactivation model within the experimental range in this study. 展开更多
关键词 acid Osmotic pressure Salmonella Enteritidis Probabilistic model Unification GENERALIZATION
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Changes in plasma total bile acid level of patients with essential hyper tension and of spontaneous hypertension rats and the correlation with systolic and diastolic blood pressures 被引量:6
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作者 张永生 吴平生 +2 位作者 刘伊丽 王煊 李欣 《Journal of Medical Colleges of PLA(China)》 CAS 1998年第4期276-279,共4页
To examine the hypothesis that plasma bile acid (BA) level is correlated with essential hypertension (EH). Methods: The level of plasma total bile acid (TBA) in 88 patients with EH and in 11 spontaneous hypertension r... To examine the hypothesis that plasma bile acid (BA) level is correlated with essential hypertension (EH). Methods: The level of plasma total bile acid (TBA) in 88 patients with EH and in 11 spontaneous hypertension rats (SHR) were measured, and regression analysis of systolic and diastolic blood pressures with plasma TBA was performed. Results: Plasma TBA level in EH patients was significantly higher than that in normotensive subjects (7. 35±3. 38μmol/L vs 4. 94±3. 25 μmol/L, PRO. of ); Plasma TBA level in SHR was significantly higher than that in Wistar--Kyoto (WKY) rats (13. 16±3. 58 μmol/L vs 10. 42±2. 24 μmol/L,P<0. 05); Plasma TBA level in patients with EH was the highest in stage Ⅲ (9. 54±4. 12 μmol/L, n =25), the lowest in stage Ⅰ (5. 76±3. 33 μmol/L, n=33), and middle in stage Ⅱ (7. 32±4. 52 μmol/L, n=30); Plasma TBA level in patients with EH was positively correlated with both systolic (r= 0. 33, P<0. 01 ) and diastolic blood pressure (r=0. 46, P<0.01 ); Plasma TBA level in SHR was positively correlated with both systolic (r=0. 82, P<0. 01 ) and diastolic blood pressures (r=0. 69, P<0. 01). Conclusion: elevated level of plasma TBA in patients with EH and in SHR may participate in the pathogenesis of hypertension. 展开更多
关键词 HYPERTENSION BILE acid DIASTOLIC BLOOD pressure SYSTOLIC BLOOD pressure
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