Zinc Losses Research Articles

Extremely rare complication in high-risk newborn on long-term parenteral nutrition and large stool losses through ileostomy.

To analyse postnatal characteristics, clinical and laboratory findings, results of investigations in the newborn (25 gestational weeks; Apgar score: 6/9 points; born per caesarean section; birth weight: 600 g; birth length: 31 cm; head circumference: 21 cm) from the first high-risk pregnancy with acquired form of acrodermatitis enteropathica. After summarizing the clinical picture with laboratory findings, we analysed the components of parenteral nutrition with regard to the deficiency of trace elements and vitamins. The zinc depletion dominated. The diagnosis is clinical, based on the presence of atypical clinical picture together with alow serum zinc concentration. Standard preparations with elementary elements do not sufficiently cover the daily needs of children, other possibilities of supplementation in intravenous form are not available. It is necessary to supplement zinc in premature children, in children with high losses of zinc (with diarrhoea, in patients with astoma, in patients with severe skin disease) (Fig. 4, Ref. 15).

Zinc(Ⅱ)-induced Neuroimmunological Renal Chronic Kidney Disease Prevention and Suppressive Progression

Zinc(Ⅱ) supplementation with 30 mg/day should become likely therapeutic chronic kidney disease (CKD) prevention implications with immense importance of CKD-associated immunological and neurological complications. Zinc induced neuroimmunological suppressive CKD progression with Stage 2 ～ 3A, 3B, zinc supplementation (30 mg/day) may be beneficial for nutritional status in CKD children and adolescents, and zinc could reduce urinary protein excretion composed of albumin and/or minimize proteinuria excretion in proteinuric CKD. In CKD 4-5 stage, risk of cardiovascular disease (CVD) become higher that zinc supplementation of 25 mg/day in zinc homeostasis has a beneficial effect for CVD in vascular dysfunction. Thus, zinc intake of 30 mg/day and serum zinc level of 60～76 μg/dL could slow down CKD Stage 4 progression. Zinc induced CKD Stage 5 (eGFR < 15) is involved that zinc is actively bound to several proteins that the decrease of circulating zinc levels in CKD is partly caused by renal losses of zinc, becoming zinc-deficiency with advanced stage CKD and ESRD in CKD. Serum zinc and serum albumin levels are 37.4 ± 5.4 and 2.6 ± 0.6 µg/dL, respectively, for as eGFR 6.6 (5.2–8.3). Zn intake of 45-75 mg/day and serum zinc level of ≤78.3 µg/dL are beneficial for HD and maintenance hemodialysis (MHD) patients, in which Zinc 15 mg/day and Selenium 50–70 μg/day that are recommended may be thought to prevent ESRD stage. Zinc induced NAD(P)H oxidase (Nox) activation occurring ROS generation in CKD cell involves assembly that ROS include the superoxide anion (O2•–), hydrogen peroxide (H2O2), and hydroxyl radicals (OH•), and in the kidney. Zinc(Ⅱ) ions-binding protein molecular mechanism is involved that Zn2+ ions-several protein complexes coordinated binding model of ligands of such as albumin, a-macroglobulin and transferrin in several proteins had been found on the binding specificity by Zn2+ ions-centered tetrahedral geometric coordination, in which causing zinc-activated serine, histidine and aspartate hydrogen residues enhance renal function activity and resulting inhibition of CKD progression proceeds.

Metal losses at the Trepça concentrator during the enrichment process

Purpose. The purpose of this paper is to determine the flow of lead, zinc and silver metals at the enrichment factory in Trepça. The authors have determined the flows of metals discharged into the tailing of Kelmend. In addition, they make a correction for the losses of Pb, Zn, and Ag metals, which are very high. Methods. Ore enrichment has been studied for two years in the production process of lead and zinc concentrates based on the following facts: selective separation of lead and zinc metallic minerals, as well as non-metallic minerals that are present in the ore. Sampling was conducted at the entrance to the ore receiving bunker. The samples were taken according to standards and sent for analysis in laboratories. In the laboratories, the samples were ground in a mill, then dried and sent for chemical analysis. The chemical analyses for Pb, Zn, and Ag were done at the Trepça laboratory, while for 35 chemical elements at the BRGM laboratory in France, with inductively coupled plasma atomic emission spectroscopy (ICP/AES) and inductively coupled plasma mass spectroscopy (ICP-MS) equipment. During the technological process, samples were taken for chemical analysis, and then in the flow, evidence was also taken to analyses the losses of lead, zinc, and silver metals. Mini Tab software was used to perform a T-test for independent samples and then correction was made for these metal losses in the tailing. The method of economic geology for the calculation of the balance of metals was used. Findings. Based on the study of the chemical analysis of ore at the entrance to the receiving bunker, then sampling during the technological process and the flow of metals into the tailing, the amount of metal losses for 2020 and 2021 has been determined. Based on the calculations of the metal balance, the metal losses that affect the economic evaluation are presented. The remains of landfills on the ground affect the pollution of the environment and rivers. Originality. The originality of the study is in the use of the results of chemical analyses obtained in the BRGM Laboratory in France on Pb, Zn, Ag and other conductive elements. A total of 35 chemical elements of tailings, which are presented in this work, have been tested. Practical implications. According to the data of chemical and geochemical analysis, it turns out that in addition to losses of Pb, Zn, and Ag, we also have losses of conductive and rare elements.

50 Years Ago in TheJournalofPediatrics: Zinc Deficiency—Both a Rare and Common Problem!

Freier S, Faber J, Goldstein R, Mayer M. Treatment of acrodermatitis enteropathica by intravenous amino acid hydrolysate. J Pediatr 1973;82:109-12. Freier et al described an infant who developed failure to thrive, a severe rash, and alopecia, as well as profound diarrhea. A sibling had died following a similar course. The diagnosis of congenital acrodermatitis enteropathica was made. She was treated initially with diiodohydroxyquinoline. She was then treated with intravenous amino acids and eventually a protein hydrolysate. Her skin and diarrhea improved with the treatment. These were considered standard treatment at the time. In retrospect, there must have been trace amounts of zinc in the hydrolysate. The infant described likely had the congenital form of acrodermatitis enteropathica, an autosomal-recessive trait involving a mutation in the zinc transporter gene. This has been localized to the SLC39A4 gene on chromosome 8. It is a rare condition, with an estimated prevalence of 1-9 per million. Acrodermatitis enteropathica was first described in 1936, but the role of zinc in treating acrodermatitis enteropathica was not recognized at the time of this article’s publication. It was an often-fatal condition. Human zinc deficiency was first described in the 1970 by Prasad—he described short patients with hypogonadism. Around the same time, parenteral nutrition increasingly was being used to support infants with severe gastrointestinal disorders. The initial solutions were often free of trace metals. There were soon increasing reports of severe rashes in infants receiving zinc-free total parenteral nutrition. It also was noted that zinc losses paralleled intestinal losses. Today, we are much more likely to see acquired acrodermatitis enteropathica. The advent of total parenteral nutrition heralded an increase in previously unrecognized nutrient deficiencies. The 2 most common were zinc and essential fatty acid deficiency; however, reports of copper, chromium, iodine, and biotin deficiency followed. There was increased recognition of the importance of trace nutrients in human health. Zinc deficiency may occur because of decreased intake, increased needs, malabsorption, increased losses, or impaired use. It may be primary or secondary, usually due to poor intake or chronic diarrhea. Recent pharmaceutical shortages have aggravated the possibility of deficiencies. Infants on prolonged exclusive breastfeeding may suffer deficiencies, and patients with prolonged diarrhea and/or severely restricted diets are also at risk.1Prasad A.S. Impact of the discovery of human zinc deficiency on health.J Am Coll Nutr. 2009; 28: 257-265Crossref Scopus (209) Google Scholar

Toward revising dietary zinc recommendations for children aged 0 to 3 years: a systematic review and meta-analysis of zinc absorption, excretion, and requirements for growth.

The Food and Agriculture Organization of the United Nations and the World Health Organization are updating their dietary zinc recommendations for children aged 0 to 3 years. The aim of this review was to retrieve and synthesize evidence regarding zinc needs for growth as well as zinc losses, absorption, and bioavailability from the diet. MEDLINE, Embase, and Cochrane Library databases were searched electronically from inception to August 2020. Studies assessing the above factors in healthy children aged 0 to 9 years were included, with no limits on study design or language. Ninety-four studies reporting on zinc content in tissue (n = 27); zinc absorption (n = 47); factors affecting zinc bioavailability (n = 30); and endogenous zinc losses via urine, feces, or integument (n = 40) met the inclusion criteria. Four reviewers extracted data and two reviewers checked for accuracy. Studies were synthesized narratively, and meta-analyses of zinc losses and gains as well the subgroups of age, type of feeding, country's income, and molar ratio of phytate to zinc were conducted. Meta-analysis revealed an overall mean (95%CI) urinary and endogenous fecal zinc excretion of 17.48 µg/kg/d (11.80-23.15; I2 = 94%) and 0.07 mg/kg/d (0.06-0.08; I2 = 82%), respectively, with a mean fractional zinc absorption of 26.75% (23.69-29.81; I2 = 99%). Subgrouping by age revealed differences in mean values associated with the transition from milk-based diets to solid food during the first 3 years of life. This review synthesizes data that may be used to formulate zinc requirements in young children. Results should be interpreted with caution because of considerable heterogeneity in the evidence. PROSPERO registration number CRD42020215236.

Changes in bioavailability of zinc during malting process and wort production

Trace metals, particularly zinc, influence the growth and metabolism of yeast. In the literature the recommended concentration of zinc in pitching wort is > 0.15 mg/L; lower concentrations cause fermentation problems and reduce in consequence final beer quality. The aim of this study was the exploration of changes in bioavailability (available zinc), which was never considered before, and in the mass balance of total zinc during malting process and wort production. Therefore, the work comprised two parts: (1) investigating the effect of malt modification on zinc content and bioavailability of, respectively, produced malt depending on malt modification by varying the steeping degree (38–48%) in the malting process and (2) examining the effect of zinc losses and changes in bioavailability in the by-products (spent grain and hot break) by performing brewing trials up to pitching wort. Zinc was measured by atomic absorption spectroscopy. We applied a specific extraction scheme to evaluate first the bioavailability of zinc in brewing-related samples. In the malting process, total zinc losses increased with greater modification level of the malt samples, although bioavailability increased simultaneously. Spent grain was the primary zinc loss by-product (98%) in the brewing process. The distribution of the binding forms of zinc in hot break and spent grain was significantly altered with an increase in the less water-soluble binding forms of zinc.

Cost-Effective and High Purity Valuable Metals Extraction from Water Leaching Solid Residues Obtained as a By-Product from Processing the Egyptian Boiler Ash

The water leaching solid residues (WLSR) obtained from salt-roasting Egyptian boiler ash are considered an essential secondary resource for (13%) nickel and (5.6%) zinc extraction. Hence, the current study aims for the cost-effective and high purity Ni, Zn, Fe and Mg metal ion extraction from (WLSR) using a sulfuric acid leaching process. The factors affecting the percentage recovery of Ni, Zn, Fe and Mg from WLSR, including leaching temperature, time, acid concentration and solid/liquid ratio, have been investigated. The obtained leaching solutions were analyzed chemically using ICP, and the different precipitates were analyzed mineralogically using XRD and EDX analysis and chemically using XRF. The maximum percentage recovery of Ni, Zn, Fe and Mg was 95.02%, 90.13%, 66.29% and 75.73%, which was obtained under the optimum leaching conditions of 8% H2SO4 concentration and 1/15 solid/liquid ratio at 85 °C for 240 min. The effect of pH, Fe2O3 dosage as nucleating agent and the precipitation duration on iron removal and Ni and Zn loss have been thoroughly studied. It has been found that >95% of the contained iron impurity can be removed, while nickel and zinc losses are around 4.2% and 3.8%, respectively. Additionally, a pH of 6 and 0.45 mol/L concentration of H2C2O4 was utilized to precipitate Mg as MgC2O4.2H2O, demonstrating that the precipitation efficiency of Mg reaches 96.9%. Nickel and zinc precipitation efficiency was 92.25% and 85.51%, respectively, by raising the solution pH to approximately 9. The kinetic of Ni and Zn dissolution has been investigated to explain the mechanism prevalent and the factors influencing the leaching process. It has been found that the nickel leaching kinetic is controlled by both diffusion through an inert porous layer and by chemical reaction with an activation energy of 20.25 kJ.mol−1. Meanwhile, the kinetic of zinc leaching is controlled by solid product layer diffusion with an activation energy of 11.67 kJ mol−1.

Computer customization errors compromised the optimization of trace element repletion dose after major burns

Major burns develop acute trace element (TE) deficiencies due to exudative losses of copper, selenium, and zinc from the wounds. A repletion strategy has been shown to decrease infectious and surgical complications. The TE doses have been adapted over time and the last adaptation, was not followed by the expected changes. The study aims at identifying the causes of the failure. Retrospective cohort study including critically ill major burns patients admitted to intensive care with burns exceeding 20% of body surface area (BSA). Period A (2011-2015) included patients admitted before the dose change, and Period B patients after (2017-2020). Demographic variables, daily TE delivery, and weekly TE blood levels were extracted from the computerized information system (CIS). Altogether 71 patients completed the inclusion criteria (Periods A and B: 42 and 29 patients respectively). They were aged 38 (32) years and burned 35 (30) % BSA, with no severity differences. Comparing periods A and B, copper (p=0.046) and selenium (p=0.031) blood levels were significantly lower in B. The dose value extracted from CIS was as planned. Customization error was found: TE salts' weight had been entered instead of elemental weight in molar units. The lower TE repletion doses administered since 2017 resulted in a significant decrease in blood levels of Cu and Se. A CIS customisation error, confusing salt weight and elemental weight was the source of the error. A systematic quality control is crucial to identify systemic errors, as is the use of the standard international units.

Improvement of lead-zinc ore mining waste processing

Expansion of mineral reserves and resources in Russia is currently connected with larger scale commercialization of rebellious ore and mining waste, and the percentage of the latter continuously grows. Due to the complex material constitution of minerals, their similar physicochemical and processing properties, as well as because of deficient ore pre-treatment, up to 20% of valuable minerals and metals are lost with tailings, mostly with very fine particles less than 10 µm. It is of the great concern to improve processing technologies for ore and mining waste. This research aims to analyze mineral compositions of tailings after lead-zinc ore flotation, and to identify causes of lead and zinc losses with the flotation tailings. The technology tests reveal that the losses lead and zinc in the form of micron size grains of galena (PbS) and wurtzite (ZnS) are connected with their aggregation with other minerals (quartz, pyrite, magnetite, etc.). The tests with physical (radiation) treatment show dissociation ability of aggregates with subsequent separation of minerals by flotation. The presence of magnetic magnetite in flotation tailings makes it possible to implement magnetic separation to increase the contents of lead and zinc in the concentrate. The scientific novelty and practical significance of this research consists in the proved expediency of radiation treatment of minerals and mining waste toward modification of their processibilty to ensure reduction in loss of valued components with tailings and to enhance environmental safety of mining waste.

Content and Balance of Trace Elements (Co, Mn, Zn) in Agroecosystems of the Central Chernozemic Region of Russia

This work is devoted to the study of the provision of arable soils with mobile forms of the most important trace elements (cobalt, manganese, and zinc). In modern Russian agriculture, the low provision of soils with trace elements is one of the reasons leading to lower yields and the deteriorating quality of most crops. The materials of the regional and local agroecological monitoring of soils in Belgorod region, which is part of the Central Black Earth region of Russia, were used in this work. The results of the local agroecological monitoring showed that the average gross contents of manganese, zinc, and cobalt in arable chernozems in the typical forest-steppe zone were respectively 345, 36.5, and 8.48 mg/kg, and in chernozems common in the steppe zone the contents were 397, 42.9, and 9.51 mg/kg. In the distribution of the gross contents of the studied trace elements in the profile of arable chernozems, a tendency of a gradual decrease in their concentrations with increasing depth was revealed. According to the results of the regional agroecological monitoring of arable soils in the Belgorod region for 2015–2018, it was found that the proportion of soils with a low content of mobile compounds of zinc (<2 mg/kg) was 90.3%; for cobalt (<0.2 mg/kg) and manganese (<10 mg/kg), the proportions were 99.3% and 38.6%, respectively. In these soils, it is advisable to introduce microfertilizers containing trace elements that are in deficit. The main sources of the manganese, zinc, and cobalt input to agroecosystems are organic fertilizers, which account for 79.3%, 86.3%, and 66.6% of the total amounts, respectively. Losses of manganese and cobalt from agroecosystems mainly occur as a result of the washing away of arable soils—82.8% and 96.8% of total losses, respectively—and 60.5% of zinc losses are due to alienation by the marketable part of the crop. A positive balance had been a feature of zinc, with an intensity of 106%, while manganese and cobalt had a negative balance, with intensities of 61.3% and 25.3%, respectively.

A dynamic material flow analysis of the global anthropogenic zinc cycle: Providing a quantitative basis for circularity discussions

Accurate and up-to-date accounting of material stocks and flows is an important quantitative basis for current Circular Economy discussions. Herein, we describe the application of dynamic material flow analysis to model the global anthropogenic zinc cycle in the period 1900 to 2019 and yielding results for 1980–2019. Results show that approx. 250 Mt of zinc were globally in use in 2019, which equals the 19-fold mine production of the same year. Between 2010 and 2019, 34 Mt of Zn in fabrication and manufacturing scrap (new scrap) and 77 Mt of Zn in end-of-life products (old scrap) became available for recycling. Of these, approx. 52 Mt of zinc were recycled, the majority (42 Mt) via direct reuse in production processes and a smaller part via refineries. The recycling input rate of 29% and the end-of-life recycling rate of 27%, both averaged between 2010 and 2019, point to opportunities for increased circularity. Nearly half of the overall cycle losses occur in the end-of-life waste collection, so that measures for more circularity should be taken at this lifecycle phase. Further considerable zinc losses arise within steel recycling, where zinc transfers to steel mill dusts. These dusts are more and more used for zinc recycling, but still underutilized. Despite existing recycling challenges, the overall modeling results show that recycling flows and recycling rates rose in the last decade.

Effects of Various Precipitants on Iron Removal from a Zinc Concentrate Pressure Leaching Solution

Autoclave leaching of zinc concentrate (Sphalerite) is an environmentally friendly process compared to roasting, which discharges pollutants into the atmosphere. Due to the amount of iron in the final product, a study is proposed to evaluate different reagents for eliminating iron from the autoclave outcome, minimizing Zn losses. The colloid formation, zinc losses, iron removal, phase separation stage characteristics (sedimentation and filtering), and reagent costs were used to evaluate six-iron precipitating reagents: CaO, Na2CO3, CaCO3, NaOH, MgO, and Ca(OH)2. CaO shows 99.5% iron removal and 87% zinc recovery. Although CaO was one of the reagents with significant zinc recovery, it presented operational difficulties in the filtration stage due to the high viscosity of the mixtures. Finally, Ca(OH)2 is the reagent recommended due to its ease of use, zinc yield recovery, electrowinning efficiency, and iron precipitate filtration rate. Zinc recovery was above 80%, while the iron concentration in the solution was below 50 ppm.

Experimental and Theoretical Investigation of the Surface Electronic Structure of ZnGa2O4(100) Single‐Crystals

Herein, a detailed experimental and theoretical investigation on the surface electronic structure of ZnGa2O4(100) bulk single‐crystals, with a special emphasis on the surface preparation, is presented. The surface crystallizes in the bulk‐derived structure, even at low annealing temperatures. Thermal treatments in ultra‐high vacuum have detrimental effects, as they cannot remove the carbon contamination and induce substantial zinc losses, further exacerbated by sputtering. A short sputtering duration and annealing in oxygen atmosphere dramatically reduce the zinc and oxygen losses in the crystal surface, leading to a contamination‐free, crystalline surface of nearly stoichiometric composition. The investigation of the valence states along the high symmetry directions of the Brillouin zone compares favorably with ab initio pseudopotential calculations, indicating a good surface quality and overall agreement with theory. An in‐depth analysis of the measured and simulated valence band peak intensities reveals difficulties associated with the precise description of the metal‐oxygen hybridization. This study provides a first fundamental understanding of the electronic structure of ZnGa2O4, while also indicating that the surface thermal instability is a challenging task that should be taken into account for the fabrication of heterostructures based on ZnGa2O4.

Recovery of zinc as zinc phosphate and by-products from hydrometallurgical treatment of hot-dip galvanizing (Zn-Al) dross

Zinc dross is the waste product generated during the hot-dip galvanizing, wherein around 11% of the total zinc is arrested by the dross leading to huge zinc losses. Though, there exist several pyro-metallurgical approaches to recover zinc but these are highly energy and cost intensive process; where hydrometallurgical processes take an edge. In this regard, this study holistically focusses on the hydrometallurgical recovery of zinc as zinc phosphate and other impurities like Al as alumina from zinc dross (Zn-Al) obtained from in-house hot-dip galvanizing unit at our laboratory. Zinc dross is leached as received in aqueous sulphuric acid medium without pulverization and stirring requirements, followed by separation of aluminium using NaOH based precipitation. Aluminium hydroxide precipitate is calcined to obtain alumina, whereas the supernatant solution is subsequently treated with disodium hydrogen phosphate to obtain products like zinc phosphate and sodium sulphate. The proposed process is simple, facile and scalable for recovery of zinc and other valuables from dross.

Estimating the First-year Corrosion Losses of Structural Metals for Continental Regions of the World

The knowledge of the first-year corrosion losses of metals (K1) in various regions of the world is of great importance in engineering applications. The K1 values are used to determine the categories of atmospheric corrosivity, and K1 is also the main parameter in models for the prediction of long-term corrosion losses of metals. In the absence of experimental values of K1, their values can be predicted on the basis of meteorological and aerochemical parameters of the atmosphere using the dose-response functions (DRF). Currently, the DRFs presented in ISO 9223:2012(E) /1/ standard are used for predicting K1 in any region of the world, along with the unified DRFs /2/ and the new DRFs /3/. The predicted values of corrosion losses (K1pr) of carbon steel, zinc, copper and aluminum obtained by various DRFs for various continental regions of the world are presented. In this work we used the atmosphere corrosivity parameters and experimental data on the corrosion losses of metals for the first year of exposure (K1exp) for the locations of the tests performed under the international UN/ECE program, the MICAT project, and the Russian program. For the first time, a comparative assessment of the reliability of various DRFs is given by comparing the values of K1pr and K1ex using graphical and statistical methods. The statistical indicators of reliability of predicting the corrosion losses of metals are calculated for various categories of atmosphere corrosivity. It is shown that the new dose-response functions offer the highest reliability for all categories of atmosphere corrosivity.

Capability for metallurgical processing of Intermediate products for the processing of polymetallic ores

The copper smelting facilities of the Ural Mining and Metallurgical Company (UMMC) mostly rely on copper-zinc and polymetallic ores. Finely disseminated minerals are associated with increased cost of selective flotation and mineral losses with dissimilar concentrates. In selective flotation of copper-zinc ores from the Urals region, between 6% (high zinc ores) and 23–44% of zinc get lost with copper concentrates depending on metal concentration and intergrowth of minerals in the ore, with the concentration of zinc in it being less than 1 %. In metallurgical processing, 90–95% of zinc contained in copper concentrates go to waste with the slag. Processing of polymetallic ores from the Altay deposits is associated with high losses of copper, lead and zinc, which get lost with dissimilar concentrates. The authors of this paper propose to obtain bulk concentrates from low zinc (0.4–1% Zn) and highly complex copper-zinc ores; obtain high-quality zinc and polymetallic (copper-lead-zinc) concentrates from polymetallic ores; set up a processing facility for polymetallic concentrates at the Mednogorsk Copper-Sulphur Plant (MCSP) that would involve the following stages: matte and zinc slag smelting – matte converted to blister copper – copper extraction from and fuming of smelter and converter slags. The main smelting vessel is currently under reconstruction aimed at introducing high-pressure highly concentrated blast oxygen; a slag fuming complex will need to be built with gas scrubbers to produce lead-zinc sublimates. An existing oxygen plant is utilised, and all sulphur containing gases are treated in a sulphuric acid facility present at the site. The advantages of the proposed processing scheme include: increased end-to-end recovery (from complex ores to refined ingots): copper — by 2.7%, zinc — by 8.1%; the output of refined lead at UMMC increased by 14 th tons with no special investment made; simpler processing schemes and a significant reduction in processing and transportation costs; rational use of the MCSP production facilities and infrastructure, raw materials available on a stable and long-term basis; an increase of 3.8 bln rubles per annum in the commodity output of UMMC.

Use of Statistical Analysis Methods for Estimating the Reliability of First-Year Carbon Steel and Zinc Corrosion Loss Predictions Calculated Using Dose-Response Functions

The following parameters have been used to estimate the reliability of predicted first-year corrosion losses of carbon steel and zinc ( $$K_{1}^{{{\text{pr}}}}$$ ): the standard determination coefficient $$R_{{{\text{st}}}}^{2}$$ according to ASTM G 16; statistical indicators such as SMAPE and MAPE; generalized determination coefficients; confidence angle. The experimental data on corrosion losses of carbon steel and zinc ( $$K_{1}^{{{\text{exp}}}}$$ ) and the atmosphere corrosivity parameters were taken from the UN/ECE international program and Russian program. The $$K_{1}^{{{\text{pr}}}}$$ values were calculated using various dose-response functions. It is not recommended to use the standard determination coefficient $$R_{{{\text{st}}}}^{2}$$ in the y = $$K_{1}^{{{\text{pr}}}},$$ x = $$K_{1}^{{{\text{exp}}}}$$ coordinates.

Micronutrient and Amino Acid Losses During Renal Replacement Therapy for Acute Kidney Injury

IntroductionMalnutrition is common in patients with acute kidney injury (AKI), particularly in those requiring renal replacement therapy (RRT). Use of RRT removes metabolic waste products and toxins, but it will inevitably also remove useful molecules such as micronutrients, which might aggravate malnutrition. The RRT modalities vary in mechanism of solute removal; for example, intermittent hemodialysis (IHD) uses diffusion, continuous veno-venous hemofiltration (CVVH) uses convection, and sustained low-efficiency diafiltration (SLEDf) uses a combination of these.MethodsWe assessed micronutrient and amino acid losses in 3 different RRT modalities in patients with AKI (IHD, n = 27; SLEDf, n = 12; CVVH, n = 21) after correction for dialysis dose and plasma concentrations.ResultsTotal losses were affected by modality; generally CVVH >> SLEDf > IHD (e.g., amino acid loss was 18.69 ± 3.04, 8.21 ± 4.07, and 5.13 ± 3.1 g, respectively; P < 0.001). Loss of specific trace elements (e.g., copper and zinc) during RRT was marked, with considerable heterogeneity between RRT types (e.g., +849 and +2325 μg/l lost during SLEDf vs. IHD, respectively), whereas effluent losses of copper and zinc decreased during CVVH (effect size relative to IHD, −3167 and −1442 μg/l, respectively). B vitamins were undetectable in effluent, but experimental modeling estimated 40% to 60% loss within the first 15 minutes of RRT.ConclusionMicronutrient and amino acid losses are marked during RRT in patients with AKI, with variation between RRT modalities and micronutrients.

Long-Term Prediction of Corrosion Losses of Metals by Means of Various Functions for the Continental Part of Russia

A comparative estimation of long-term prediction of corrosion losses of carbon steel and zinc has been performed. Predictions have been obtained by means of the exponential-linear function and the dose-response function for the continental part of Russia.

Modeling of Atmospheric Corrosion in the Tropical Climate of Vietnam

The kinetics of corrosion losses of carbon steel, copper, and zinc in the continental and coastal areas of Vietnam is studied by in situ testing. The dominant climate and aerochemical atmospheric factors are revealed with respect to the metals tested in different periods of their exposure. The mathematical models that characterize the relationship between the time of wetness of metal surface, atmospheric pollution, and corrosion rate are developed. Based on power law model M = At k , the values of constants A and k are calculated for each metal and test site, where parameter A characterizes corrosion losses of metal for the first year of exposure and k denotes the protective properties of a layer of corrosion products.