Investigation of Heavy Metal Contents in Traditional Chinese Herbal Medicine Peristrophe roxburghiana Collected from Northwest of Guangxi

Objective] This study was conducted to evaluate the product quality and safety of Peristrophe roxburghiana_ col ected from different places in Hechi City, northwest of Gunagxi, so as to provide basic data for further development and uti-lization of the characteristic plant resource P. roxburghiana. [Method] Contents of 9 kinds of heavy metals including Cd, Mn, Pb, Zn and Cu in the herb were deter-mined by the method of wet digestion-flame atomic absorption spectrophotometry and atomic fluorescence spectrometry, respectively. [Results] Heavy metal contents of Cd, Mn, Pb, Fe, Cu, Zn, As, Hg and Se were 1.62-17.25, 8.93-142.53, 4.37-18.43, 103.7-242.81, 2.55-5.35, 85.40-146.30, 0.07-0.54, 0.00-0.08 and 0.00-0.47 mg/kg, respectively. According to the national food safety standards and Green Trade Standards of lmporting ＆amp; Exporting Medicinal plants ＆amp; Preparations, the heavy metal contents of the P. roxburghiana_samples col ected from different coun-ties in Hechi City exceeded standards or at the critical values. Among which, Cd, Pb and Zn contents of the samples are seriously higher than the standards. [Con-clusion] Therefore, the impact of soil heavy metal pol ution on the safety of edible plants in the northwest of Guangxi should be highly concerned.

Investigation and Evaluation on Soil Heavy Metal Contents in Fruit Producing Area in Baise City,Guangxi Zhuang Autonomous Region

[Objective] This study was conducted to investigate heavy metal conditions in fruit producing area in Baise City, Guangxi Province. [Method] Heavy metal contents in 106 soil samples collected from fruit producing area in Youjiang District, Baise City, Guangxi Province were analyzed, and soil heavy metal pollution condition in this area was estimated applying single factor index method and Hakanson＇ potential ecological risk index method with reference to the second grade of National Soil Environmental Quality Standard and soil background values of this area. [Result] According to the second grade of National Soil Environmental Quality Standard, soil heavy metals in this fruit producing area is at the level of no pollution; and the total potential ecological risk pollution risk （RI） of soil heavy metals was 97.7, indicating no risk. [Conclusion] The fruit producing area in Baise City, Guangxi Province is free of heavy metal pollution.

Characteristics and Risk Assessment of Soil Heavy Metal Contents in Facility Agriculture of Guangxi

[Objectives]To study the characteristics of soil heavy metal contents in facility agriculture of Guangxi and analyze its risks.[Methods]The heavy metal content of 30 surface soil samples taken from facility agriculture in Guangxi was analyzed.The status of soil heavy metal pollution in facility agriculture of Guangxi was evaluated by the single factor index method,geo-accumulation index method and Hakanson potential ecological risk index method with reference to the soil background value in Guangxi.[Results]Compared with the soil background value in Guangxi,the over-limit rates of heavy metals cadmium,lead,arsenic,chromium,mercury,copper and zinc in soil samples were 56.67%,56.67%,16.67%,30.00%,50.00%,60.00%and 80.00%,respectively.Compared with the screening values of the Soil Environmental Quality-Risk Control Standard for Soil Contamination of Agricultural Land(for trial implementation)(GB15618-2018),the overlimit rates of the heavy metals cadmium,arsenic,copper and zinc in the surface soil of agricultural facilities in Guangxi were 56.67%,10.00%,16.67%and 23.33%,respectively.Except for the average content of soil cadmium exceeding the screening value,the evaluation content of the other six soil heavy metals did not exceed the screening value.According to the evaluation results of the single factor pollution index method,the surface soil arsenic and chromium of the agricultural facilities in Guangxi belonged to the clean level,lead,mercury,and copper belonged to mild pollution,and cadmium and zinc belonged to moderate pollution.According to the evaluation results of the geo-accumulation index,the lead,arsenic,chromium and mercury in the surface soil of the agricultural facilities in Guangxi belonged to the pollution-free level,while the cadmium,copper and zinc belonged to the mild-moderate pollution.According to the evaluation results of the potential ecological risk index method,the potential ecological risks of the heavy metals of lead,arsenic,chromium,copper and zinc in the soil of agricultural facilities in Guangxi belonged to low potential ecological risk level,and the potential ecological risks of cadmium and mercury belonged to moderate risk level.The potential ecological risk index(RI)of the seven heavy metals in the soil was 132.46,which belonged to moderate potential ecological risk.The largest contribution of soil heavy metals to the potential ecological risk index was cadmium and mercury.[Conclusions]Taking the soil of facility agriculture in Guangxi as the object,this paper studied the characteristics of heavy metal content in facility agricultural soil and its risk assessment,in order to provide a scientific basis for facility soil heavy metal risk prevention and control and provide safe technology for facility agriculture.

CO oxidation under lean and stoichiometric conditions over ceriazirconia with very low metal contents(Cu,Co,Ag and Pt)

In this work,several ceria-zirconia based catalysts with very lo w(and equimolar) metal contents were prepared,characterised and tested for the CO oxidatio n reaction(under lean and stoichiometric conditions),trying to emulate those conditions found in a diesel oxidation catalyst(DOC) system from a diesel engine and those encountered under gasoline exhaust(λ=1).The metals chosen are Cu,Co,Ag and Pt(as a reliable benchmark).The results reveal enormous differences among reducibility and catalytic activity despite quite similar structural and textural properties of the catalysts,showing differences among dispersion(Ag-catalyst seems to present a low level of dispersion).This catalyst seems to be characterised,as well,by a strong electronic interaction between Ce and Ag centres which is suggested to yield an improved reducibility under H_(2)-TPR conditions.Nevertheless,the order in catalytic activity(Cu>Ag>Co≈Pt>>support) seems not to follow the order found in reducibility and the Cu-catalyst seems to be the most active independently on the reaction conditions,yielding nearly overlapped CO oxidation catalytic curves.Inte restingly,a stro ng correlation between the catalytic activity under the two conditions tested and the OSC values of the Ce_(0.8)Zr_(0.2)O_(2)-supported metal catalysts is found.Therefore,OSC parameter measured at 150℃ can be used as a relevant descriptor to evaluate the CO oxidation activity at low and medium conversions for the investigated catalysts,much better than the H_(2)-TPR measurements.

Overview of Precious Metal Content Analysis Methods in Automotive Catalytic Converter

With the increasing awareness of environmental protection, people’s concern of pollution issues arising. Vehicles, as the most important means of transportation, its exhaust emission has received considerable attention. The catalytic converter is able to purify harmful substances in exhaust gas. The absolute content of precious metals in the catalytic converter dominates the exhaust gas purification effect. Accurate detection of precious metal content is of great significance for controlling the cost of catalysts, ensuring catalytic performance and recovering precious metals from spent catalysts. We herein summarized several instruments for precious metals content exploration, such as X-ray fluorescence spectrometer (XRF), atomic absorption spectrometer (AAS), inductively coupled plasma emission spectrometer (ICP) and spectrophotometer. In this thesis, the feasibility of using various devices for characterizing precious metal content in catalytic converters is analyzed and their strengths or weaknesses are elaborated.

Heavy metals in suspended matters during a tidal cycle in the turbidity maximum around the Changjiang(Yangtze) Estuary

In order to discuss the content distributions and fluxes of heavy metals in suspended matters during a tidal cycle in the turbidity maximum around the Changjiang （Yangtze） Estuary, the contents of heavy metals （Zn, Pb, Cd, Co and Ni） have been analyzed. During a tidal cycle, the average contents of heavy metals are in the order of Zn〉Ni〉Pb〉Co〉〉Cd. The average contents in ebb tide are generally higher than that in flood tide. However, at the inshore Sta. 11, influenced by the contamination from the nearby waste treatment plant, the average contents of Zn and Ni in flood tide are higher than those in ebb fide and at the offshore Sta. 10, the content of Cd in flood tide higher than that in ebb tide due to marine-derived materials. The five heavy metals, mainly terrigenous, are transported towards east-northeast, and settle down with suspended matters in the area between Sta. 11 and Sta. 10. Influenced by marine-derived materials, the flux value of Cd does not alter significantly with obviously changing in flux direction towards northwest. The source of heavy metals, the salinity of water and the concentration of suspended matters are the main factors controlling the content distributions of heavy metals during a tidal cycle. There is a positive correlation between the contents of heavy metals （Zn, Pb, Co and Ni） and the salinity of water, while the opposite correlation between the contents and the concentrations of suspended matters. Because of marine-derived materials, the content of Cd is not correlated with the concentration of suspended matters and the salinity of water.

High plastic Zr–Cu–Fe–Al–Nb bulk metallic glasses for biomedical applications

Four Zr–Cu–Fe–Al-based bulk metallic glasses（BMGs） with Zr contents greater than 65at% and minor additions of Nb were designed and prepared. The glass forming abilities, thermal stabilities, mechanical properties, and corrosion resistance properties of the prepared BMGs were investigated. These BMGs exhibit moderate glass forming abilities along with superior fracture and yield strengths compared to previously reported Zr–Cu–Fe–Al BMGs. Specifically, the addition of Nb into this quaternary system remarkably increases the plastic strain to 27.5%, which is related to the high Poisson＇s ratio and low Young＇s and shear moduli. The Nb-bearing BMGs also exhibit a lower corrosion current density by about one order of magnitude and a wider passive region than 316 L steel in phosphate buffer solution（PBS, pH 7.4）. The combination of the optimized composition with high deformation ability, low Young＇s modulus, and excellent corrosion resistance properties indicates that this kind of BMG is promising for biomedical applications.

Metabolic investigations in patients with hepatitis B and C

AIM:To investigate the similarities and dissimilarities in patients with hepatitis B and hepatitis C,clinically and metabolically. METHODS:Fifty patients with hepatitis B virus and hepatitis C virus infection were included in this study, along with fifty healthy controls for comparison purposes.Intravenous blood(10 mL)samples from patients and healthy subjects were collected and made to clot before serum was separated and immediately levels of the enzymes,alkaline phosphatase(ALK),creatinine phosphokinase(CPK),lactate dehydrogenase (LDH),serum glutamate oxaloacetate transaminase(sGOT)and serum glutamate pyruvate transaminase(sGPT)were determined by a kit method.For total con-tent of each metal the serum samples were analyzed using atomic absorption spectrophotometry.Levels of cholesterol,triglycerides,urea,creatinine and uric acid were determined using a kit method on Microlab 300. RESULTS:Serum magnesium and copper levels remained unchanged,whereas the concentration of zinc decreased and iron increased significantly in both groups of patients.Total antioxidant activity was significantly decreased in both hepatitis B and C.Among the enzymes analyzed,ALK,s-GPT,LDH and s-GOT were all significantly increased in both patients with hepatitis B and C whereas CPK was significantly decreased in patients with hepatitis B and remained unchanged in patients with hepatitis C. CONCLUSION:The information accumulated by this study will help provide a better understanding of involved metabolic processes in order to design appropriate therapeutic approaches for treating these patients,so they can recover and lead normal lives.

Effect of nonuniform sintering on mechanical and thermal properties of silica-based ceramic cores

During sintering of the silica-based ceramic core of turbine blades,a phenomenon called"nonuniform sintering"occurs that negatively affects the thermal and mechanical properties of the core.Standard samples of silica-based core were prepared by an injection molding method and sintered with alumina backfilling powder with different sodium contents.The effect of sodium content on the nonuniform sintering of silica-based cores and the thermal and mechanical properties was evaluated.Results show that the sintering level and the content ofα-cristobalite in the surface layer are significantly higher than that of the sample interior.A considerable number of microcracks are found in the surface layer due to theβtoα-phase transition of cristobalite.As the sodium content in the alumina powder decreases,the level of the nonuniform sintering and the amount of crystallized cristobalite in the surface layer decrease,which is beneficial to the thermal expansion and flexural strength at ambient temperature.The flexural strength and thermal deformation at high temperature are improved by reducing the surface cracks,but deteriorated with the decrease of the cristobalite crystallization when the surface cracks are macroscopically invisible.

Microwave response characteristics and influencing factors of ores based on dielectric properties of synthetic samples

In order to understand the influence of different factors on the microwave response characteristics of ores,the effects of electrical conductivity,metal mineral content,compactness,metal mineral distribution,microwave frequency and temperature on the dielectric properties of synthetic ores(metal mineral and quartz)were studied.Microwave heating tests were carried out on three types of natural ores(Hongtoushan copper ore,Sishanling iron ore and Dandong gold ore)with significant differences in metal mineral contents.The test results showed that under microwave irradiation,the stronger the electrical conductivity of the metal minerals,the smaller the penetration depth in synthetic ore.For those metal minerals with lower electrical conductivity,the microwave absorption coefficient of the synthetic samples increases with increasing metal mineral content.For those metal minerals with higher electrical conductivity,the microwave absorption coefficient of the samples first increases and then decreases as the metal mineral content increases.When the metal minerals are distributed in layers,the penetration depth is much less than that given a uniform distribution.The penetration depth in the sample at microwave frequency of 915 MHz is greater than that at 2.45 GHz.The higher the electrical conductivity of metal minerals used in synthetic ores,the higher the high-temperature sensitivity of electromagnetic shielding coefficient(0.C-500.C).The Hongtoushan copper ore with high metal mineral content exhibits obvious size effect.The effects of ore structure and crystal particle size on the distribution characteristics of microcracks were discussed.Based on the test results,a quantitative prediction model of microwave sensitivity of ore was proposed,which provides guidance for the prediction of ore heating effect and the selection of microwave heating sequence of ore.

In-situ observation of microstructural evolution in reheated low carbon bainite weld metals with various Ni contents

Microstructural evolution in weld metals was in-situ observed through utilizing a laser scanning confocal microscope at two cooling rates.The specimens with various nickel contents were adopted for the observation.In the specimen with low fraction of Ni（≤2 wt.%）,granular bainite microstructure（i.e.broad surface relief）transformation from intragranular nucleation site was in-situ observed,while,lath bainite microstructure originating from grain boundary of austenite was in-situ observed for specimens with high mass percentage of Ni（≥4 wt.%）.With increasing nickel content,the transformation temperature dropped.The prior austenite grain size was initially depressed and subsequently coarsened dramatically with the addition of Ni.The microstructure difference was ascribed to various nucleation sites and growth direction in the matrix.On account of those observations,not only the chemical component,cooling rate and microstructure were systematically correlated,but also the microstructural evolution was definite.

Physicochemical and elemental studies of Hydrocotyle javanica Thunb. for standardization as herbal drug

Objective: To explore the leaves of Hydrocotyle javanica Thunb. as a source of safe and effective antibacterial herbal medicine.Methods: The standardization was validated by stepwise physicochemical studies,element analysis, determination of ash values, fluorescence analysis, assessment of moisture content, extractive values in different solvent systems and extraction methods.Heavy metal contents, mineral and element contents were analysed by atomic absorption spectrophotometry, inductively coupled plasma-mass spectrometer and CHNS/O analyser, respectively.Results: The methanol extract of the folklore medicinal plant having antibacterial efficacy contained flavonoids and phenolic OH groups. The ICP multi standard indicated the presence of three major compounds with molecular mass of 161 190 and 221 Da. Heavy metals viz. lead, mercury and copper content were 4.38 ppm, < 0.05 ppm and 24.70 ppm,respectively. Minerals content of calcium, phosphorus, potassium and iron were 1 190.94 mg/100 g, 375.57 mg/100 g, 2 820 mg/100 g and 340.20 mg/100 g of plant sample, respectively. Elements like carbon, hydrogen, nitrogen and sulphur contents were38.18%, 5.67%, 2.23% and 0.51%, respectively. Heavy metal profile of the tested plant was within the permissible limits of the regulatory authorities.Conclusions: Hence the present physicochemical and elements studies reveals that the plant Hydrocotyle javanica Thunb. could be a potent source of herbal preparation as well as a safe and novel synthetic antibacterial drug.

Quality Assessment of Different Industrial Effluents for Irrigation in Agriculture

A laboratory experiment was undertaken in Soil Science Division of BRRI （Bangladesh Rice Research Institute） during 2010 to assess the quality of industrial effluents and city waste as a source of irrigation water for agriculture. The treatments of the studies were the effluents of five different industrial sources like polyvinyl, dyeing, pharmaceuticals, beverage, tannery, mixed waste water （contaminated with effluents from many industries）, CWW （city waste water） and underground water as control. The industrial effluents, MWW （mixed waste water）, CWW and control water were tested for electrical conductivity, pH, and soluble ions such as Na^＋, Ca^2＋, Mg^2＋, K^＋, HCO3-, CO3^2-, NH4^＋-N and H2PO4^-. Micronutrients （Fe, Mn, Cu and Zn） and heavy metals （As, Pb, Cd, Cr and Ni） were analyzed from the samples. Beverage industry effluent showed acidic reaction, while the other industrial effluents showed alkaline reaction （pH 7.25-9.07）. Pharmaceutical, dyeing and tannery effluents showed EC of 3.40, 4.30 and 9.49 dS m^-1, respectively, compared to 0.54 dSm^-1 of the control. All the effluents except polyvinyl and beverage effluents and CWW recorded higher carbonate and bicarbonate content than that of control. Industrial effluents and CWW were higher in micronutrient content as compared to control. Dyeing, pharmaceutical and tannery effluents contained 2.51, 3.94 and 4.29 mg L^-1 lead, 0.15, 0.14 and 0.38 mg L^-1 chromium and 0.25, 0.24 and 0.16 mg L^-1 nickel, respectively which might be concemed for health hazard through food chain.

Heavy metal content in scalp hair of the inhabitants near Dexing Copper Mine,Jiangxi Province,China

Levels of seven metals （Mn, Cu, Zn, Pb, Cr, Cd, and Se） in the scalp hair of Daicun and Xiangtian inhabitants were determined by ICP-MS/AFS. Daicun, as an experimental site, is near Dexing Copper Mine, Jiangxi Province, China, and exposed to mining pollution; Xiangtian, as a control site, is free from any mining and other industrial pollution. The heavy metal distribution in the scalp hair of the two diverse population segments exposed to different environments was discussed against the background of the heavy metal content of local plants, waters, and soils. The results show： 1） Levels ofCu, Zn, Pb, Cr, and Cd in the scalp hair of Daicun inhabitants were higher compared with Xiangtian counterparts which showed higher comparative levels of Se and Mn. But there were no significant differences of the levels of Cu and Zn in the hair samples between the two villages. In the hair of the inhabitants in the two villages, the levels for Se, Zn, and Cu were lower, while the level for Mn was higher, than the corresponding levels from other regions of the world. Compared with the standard issued by the Trace Element Research Council of China for Chinese inhabitants there were serious Se, Zn, Cu and Cr-deficiency phenomena in the hair samples from Daicun and Xiangtian. 2） Against the geological background of high levels ofZn, Cu, Se and Cr, there were deficiencies of Zn, Cu, Se and Cr in the hair samples of the Daictm population. This may have been caused by the distribution forms of the heavy metals in the soils, and antagonism among the elements. 3） Principal Component Analysis （PCA） and Cluster Analysis （CA） indicated that the origins of the heavy metals in the hair samples from the two villages had some differences as well as some similarities, this should be contributed mainly to the influence of the mining activities.

Model of Hot Metal Silicon Content in Blast Furnace Based on Principal Component Analysis Application and Partial Least Square

In blast furnace （BF） iron-making process, the hot metal silicon content was usually used to measure the quality of hot metal and to reflect the thermal state of BF. Principal component analysis （PCA） and partial least- square （PLS） regression methods were used to predict the hot metal silicon content. Under the conditions of BF rela- tively stable situation, PCA and PLS regression models of hot metal silicon content utilizing data from Baotou Steel No. 6 BF were established, which provided the accuracy of 88.4% and 89.2%. PLS model used less variables and time than principal component analysis model, and it was simple to calculate. It is shown that the model gives good results and is helpful for practical production.

Soil calcium content as the driving factor for vegetative structure and soil microbial function diverging across a fire chronosequence of the boreal forests in northeast China

The role of biophysical variables in constructing community structure changes with the time since fire.The major objective of this study is to verify the transition stage and its underlying variables for the postfire forest and soil microbial function in the boreal forested area of China.A 50-year fire chronosequence was presented,and biomass of forbs,shrubs and woody plants was separately weighted to assess their contribution to the whole community with the year since fire(YSF).Simultaneously,soil biophysical properties were measured for stands in different time periods after fire.Soil microbial functions,i.e.growth efficiency(GE)and carbon use efficiency(CUE),were calculated based on ecoenzymatic and soil nutrient stoichiometry.In terms of vegetative structure,forbs’proportion decreased from 75%to 1.5%,but the proportion of woody plants increased from 0.04%to 70%across this fire chronosequence.GE and CUE of soil microorganisms averaged 0.242 and 0.236 and were significantly higher in 9,15 and 31 YSF than in 2 and 3 YSF.Soil metal content was significantly increased at the late stage of this fire chronosequence,and soil calcium content showed a positive correlation with woody plant biomass and a negative correlation with soil microbial function.Overall,the present work highlights that the time period of 15 and 31 YSF is a hallmark stage for aboveground vegetative structure and soil microbial function to change in different trends and that the calcium content may partly account for these two divergent trajectories.