Processing of Low-Quality Gibbsite-Kaolinite Bauxites

The results of studies on the processing of gibbsite-kaolinite bauxite are presented. The developed technology includes preliminary chemical activation and thermal transformation during enrichment to obtain a concentrate suitable for processing by the Bayer method. As a result of the chemical activation of gibbsite-kaolinite bauxite in a solution of sodium bicarbonate, a change in the phase composition occurs, which made it possible to improve the results of gravity enrichment with the production of a coarse-grained gibbsite fraction. The transformation of bauxite in the temperature range of 900–1000 °C is explained by the decomposition reactions of siderite, gibbsite, kaolinite, calcite, dolomite and sodium ferro-sulfide oxide, as well as the formation of sodium aluminosilicate, hematite, quartz and the chemically stable phase of corundum. The optimum firing temperature of bauxite is 950 °C, after which, as a result of alkaline treatment during chemical enrichment, the extraction of SiO2 into solution was 74.9%. A silicon modulus of enriched bauxite 10.9 units was obtained. As a result of the autoclave leaching of gibbsite-kaolinite bauxite after a two-stage enrichment, the maximum extraction of alumina into solution was 87.4%. The yield of red mud during the processing of bauxite enriched and calcined at 950 °C was 37.62%. During the autoclave leaching of bauxite without enrichment, the yield of red mud was 71%

Processing of Low-Quality Gibbsite-Kaolinite Bauxites

The results of studies on the processing of gibbsite-kaolinite bauxite are presented. The developed technology includes preliminary chemical activation and thermal transformation during enrichment to obtain a concentrate suitable for processing by the Bayer method. As a result of the chemical activation of gibbsite-kaolinite bauxite in a solution of sodium bicarbonate, a change in the phase composition occurs, which made it possible to improve the results of gravity enrichment with the production of a coarse-grained gibbsite fraction. The transformation of bauxite in the temperature range of 900–1000 °C is explained by the decomposition reactions of siderite, gibbsite, kaolinite, calcite, dolomite and sodium ferro-sulfide oxide, as well as the formation of sodium aluminosilicate, hematite, quartz and the chemically stable phase of corundum. The optimum firing temperature of bauxite is 950 °C, after which, as a result of alkaline treatment during chemical enrichment, the extraction of SiO2 into solution was 74.9%. A silicon modulus of enriched bauxite 10.9 units was obtained. As a result of the autoclave leaching of gibbsite-kaolinite bauxite after a two-stage enrichment, the maximum extraction of alumina into solution was 87.4%. The yield of red mud during the processing of bauxite enriched and calcined at 950 °C was 37.62%. During the autoclave leaching of bauxite without enrichment, the yield of red mud was 71%

Associations between depression, anxiety and medication adherence among patients with arterial hypertension: Comparison between persons exposed and non-exposed to radiation from the Semipalatinsk Nuclear Test Site

In this study, we investigated the association between depression, anxiety and medication adherence in patients with arterial hypertension living in East Kazakhstan region. The sample size included 795 patients, of whom 403 patients were exposed to radiation at the Semipalatinsk Nuclear Test Site from 1949 to 1989, while 395 patients were unexposed to radiation due to their very remote residence from the Site at the same period. Both exposed and unexposed patients showed no significant differences concerning body mass index, smoking habit, the presence of hypercholesterolemia, and hypertension grade. Patients with arterial hypertension previously exposed to radiation had significantly higher rates of low medication adherence, subclinical and clinical depression, situational anxiety of moderate and severe grade, and personal anxiety of moderate grade. A logistic regression analysis allowed us to identify the presence of significant positive association between medication adherence and anxiety in exposed patients (OR = 4041 (95%CI:1709-9556) p = 0.001) and marginal association (OR = 2998 (95%CI:1008-8915) p = 0.048) between the same parameters in unexposed patients. It might prove to be useful to introduce psychological and medical counseling with an emphasis on strengthening of medication adherence and to inform the local population about radiation effects and dosimetry data

Early predictors and prognostication of children chronic kidney disease in the conditions of environmental disability

The kidneys do not have a direct connection withexternal agents, but the elimination of a varietyof harmful environmental substances fromthe human body mainly occurs through this organ. At thesame time, the kidneys experience a significant functionalload, which can be realized in the clinical course, and inthe occurrence of kidney disease. The goal of our studywas to identify early predictors of diagnosis and predictionof children chronic kidney disease (CKD) in conditions ofenvironmental distress. The frequency, clinical and laboratorycharacteristics of chronic kidney disease were studiedamong 460 children from the industrial zone, betweenthe ages of birth and 18 years old (girls - 258 and boys- 202). All children were treated in the nephrology departmentof the regional children’s clinical hospital in theperiod from 2015 to 2017. We have identified three riskgroups for the development of children CKD in conditionsof environmental distress: the “high risk” group is an unfavorableprognosis group, the “medium risk” group is“attention group” and the “minimal risk” group. The revealedfeatures of children CKD of the main region indicatepronounced functional disorders and changes in thestructure of the renal tissue, which is caused by prolongedcontact with polymetallic dust. The nature of the revealedfeatures of children CKD of the main region indicates theintensity of the process of adaptation of the organism toadverse environmental factors and the predominant latentand low manifestation course of the disease

Early predictors and prognostication of children chronic kidney disease in the conditions of environmental disability

The kidneys do not have a direct connection withexternal agents, but the elimination of a varietyof harmful environmental substances fromthe human body mainly occurs through this organ. At thesame time, the kidneys experience a significant functionalload, which can be realized in the clinical course, and inthe occurrence of kidney disease. The goal of our studywas to identify early predictors of diagnosis and predictionof children chronic kidney disease (CKD) in conditions ofenvironmental distress. The frequency, clinical and laboratorycharacteristics of chronic kidney disease were studiedamong 460 children from the industrial zone, betweenthe ages of birth and 18 years old (girls - 258 and boys- 202). All children were treated in the nephrology departmentof the regional children’s clinical hospital in theperiod from 2015 to 2017. We have identified three riskgroups for the development of children CKD in conditionsof environmental distress: the “high risk” group is an unfavorableprognosis group, the “medium risk” group is“attention group” and the “minimal risk” group. The revealedfeatures of children CKD of the main region indicatepronounced functional disorders and changes in thestructure of the renal tissue, which is caused by prolongedcontact with polymetallic dust. The nature of the revealedfeatures of children CKD of the main region indicates theintensity of the process of adaptation of the organism toadverse environmental factors and the predominant latentand low manifestation course of the disease

A review of crop residue-based biochar as an efficient adsorbent to remove trace elements from aquatic systems

International audienceCrop residue-based biochar (CRB) has shown great potential for removing trace elements (TEs) from aquatic matrices. Despite the increasing interest in this area, no review has focused specifically on the efficacy of CRB for TEs removal in aquatic environments. This comprehensive review examines the global TEs water contamination status with an emphasis on their sources, compositional metrics for crop residue feedstock (proximate, ultimate, and lignocellulosic properties), and the potential use of CRB for TEs removal in aquatic media. It also evaluates the factors that affect the ability of CRB to remove TEs, such as feedstock type, production conditions, water pH, background electrolytes, water temperature, CRB/water ratio, and underlying pollutant sorption mechanisms. This review also discusses the practical applications of CRB in real water samples and engineering considerations for designing CRB with improved physicochemical properties, treatment efficiencies, and regeneration abilities. Additionally, the cost-benefit and economic assessment of CRB, challenges, and future research directions related to CRB are highlighted to promote research on this sustainable source of biochar. By elucidating the prospects of CRB as an adsorbent, this review emphasizes the need for continued research on its practical implications for environmentally relevant pollutant concentrations. Crop residue-based biochar (CRB) emerged as a top-notch adsorbent for TEs in aquatic systems. The CRB adsorption potential depended on the experimental conditions. The application of CRB to real water samples highlights its potential on a larger scale. Engineer-designed CRB exhibits high treatment efficiencies and regeneration abilities

Ancient Components and Recent Expansion in the Eurasian Heartland: Insights into the Revised Phylogeny of Y-Chromosomes from Central Asia

In the past two decades, studies of Y chromosomal single nucleotide polymorphisms (Y-SNPs) and short tandem repeats (Y-STRs) have shed light on the demographic history of Central Asia, the heartland of Eurasia. However, complex patterns of migration and admixture have complicated population genetic studies in Central Asia. Here, we sequenced and analyzed the Y-chromosomes of 187 male individuals from Kazakh, Kyrgyz, Uzbek, Karakalpak, Hazara, Karluk, Tajik, Uyghur, Dungan, and Turkmen populations. High diversity and admixture from peripheral areas of Eurasia were observed among the paternal gene pool of these populations. This general pattern can be largely attributed to the activities of ancient people in four periods, including the Neolithic farmers, Indo-Europeans, Turks, and Mongols. Most importantly, we detected the consistent expansion of many minor lineages over the past thousand years, which may correspond directly to the formation of modern populations in these regions. The newly discovered sub-lineages and variants provide a basis for further studies of the contributions of minor lineages to the formation of modern populations in Central Asia

Causes of delayed immunization with pneumococcal vaccine and aetiological patterns of pneumonia in young children

To analyze the causes of delayed immunizationwith pneumococcal vaccine, as well as the impactof vaccination on the aetiology and severityof pneumonia in young children. Individual healthrecords (f112/u) and vaccination records (f 063) of 309children with delayed pneumonia vaccination were studied.The children were divided into two groups. The firstgroup includes children (n=163) with vaccination refusals,the second group includes those with temporary medicalcontraindications (n=146). Additionally, retrospectivestudy of health records of 71 children aged 0 days to 1.5years was conducted. They were divided into 2 groups:the first included vaccinated children (n=36), the second– unvaccinated (n=35). To compare the data of 2 groups,IBM SPSS Statistics 20 was used for the calculation of CI(Confidence interval) for the ratio with the specified plevel– 0.05. Vaccination refusals in the described casesamounted to 52.7%, temporary medical contraindicationwas 47.2%. Among the main reasons for vaccination refusals,distrust of the vaccine is a prevailing one – 39.9%.Severe pneumonia in unvaccinated children was 42.9%(CI 95%, 26.5-59.3) of the total number of cases. In vaccinatedchildren, the proportion of severe pneumonia was22.2 % (CI 95%, 8.6 – 35.8) of the total number of cases.Thus, cases of severe pneumonia development in unvaccinatedchildren are 20.7% more than in vaccinated children,p>0.05. It should be noted that the applied for thecomparison 95 % CI did not show statistically significantdifferences in the two groups, which indicates the needfor further study of the issue of increasing the sample size