Molybdenum Content Research Articles

Properties of high-strength complex-alloy steel for casing pipes in cold-resistant and corrosion-resistant versions

The influence of alloying on the properties of high-tempered steels used for the production of casing pipes has been studied. It has been shown that an increase of molybdenum content from 0.15 to 0.53% provides a noticeable increase of the mechanical characteristics in chromium-molybdenum steels after tempering at 600‒690 °C. Alloying with vanadium and niobium contributes to an additional increase in strength properties. The influence of vanadium on the highly viscoplastic properties of steels is shown. It has been established that the greatest strengthening of steel with 0.32% molybdenum in a highly tempered state is provided by complex alloying with niobium and vanadium. The influence of austenitization and tempering temperature on the structure and properties, including resistance to cracking in an environment saturated with hydrogen sulfide, of chromium-molybdenum steel grade 26CrMoVNb-2 with micro-alloying additives of vanadium and niobium was determined. Alloying with molybdenum, vanadium and niobium makes it possible to obtain steels for high-strength casing pipes that are resistant to brittle fracture and sulfide stress corrosion cracking, subject to comprehensive consideration of the main factors such as austenitization temperature, tempering temperature and duration, dispersion and homogeneity of microstructure

Research and assessment of the molybdenum oxide (VI) nanoparticles toxiсity under inhalation in WISTAR line rats in comparison with the micro-sized chemical analog

Introduction. Molybdenum (VI) oxide nanoparticles (MoO3 NPs) are being actively introduced into practical use as part of catalysts, optics, plastics, textiles, coatings, and lubricants, gas sensors, and crude oil refining processes. MoO3 NPs are known to exhibit toxic properties when interacting with living systems. Atmospheric air pollution with potentially dangerous MoO3 NPs can contribute to the inhalation exposure in the population and, as a result, the development of health disorders caused by the toxic effect of the nanomaterial. In this regard, the study of the adverse effects caused by MoO3 NPs entering the body during aerogenic exposure is particularly relevant.
 
 The aim of the study. Investigation and evaluation of subacute toxicity of MoO3 NPs by the inhalation route of entry into the body in comparison with a microsized chemical analogue.
 
 Materials and methods. The physical properties of MoO3 NPs were studied in comparison with microparticles (MPs). In an experiment on Wistar rats, a comparative analysis was performed and a characteristic of the pathogenetic features of the toxic effect of particles during subacute inhalation exposure at a concentration of 1.84 mg/m3 was given.
 
 Results. According to the totality of physical properties, the MoO3 sample under study is a nanomaterial with an average particle size of 58.8 nm, constituting 84.2% of the total number of particles. MoO3 NPs accumulate in the heart, lungs, kidneys, and brain. The concentration of molybdenum is by 2.50–15.85 times higher than the control levels. The highest content of the studied element was found in the lungs. Bioaccumulation of MP MoO3 was noted only in the lungs, while the concentration of molybdenum is by 3.00 times less in comparison with the exposure to NPs. When exposed to MoO3 NPs, more pronounced changes in biochemical (an increase in the activity of alkaline phosphatase, LDH, the concentration of total bilirubin and creatinine by 1.29–2.11 times) and hematological parameters (a decrease in the number of platelets and thrombocrit by 1.2 times) of blood were noted relative to the impact of a microscale analogue. Under the influence of NPs and MPs of MoO3, pathomorphological changes develop in the lungs, brain, and liver tissues. When exposed to NPs, compensatory lung emphysema, focal microvesicular steatosis in hepatocytes, and acute plethora in the liver were found, which were not detected during exposure to NPs.
 
 Limitations. The study was performed only with subacute inhalation exposure to NPs and MPs of MoO3 in Wistar rats.
 
 Conclusion. MoO3 NPs have a higher degree of bioaccumulation and toxicity relative to MPs. The results of the study make it possible to expand theoretical concepts and gain new knowledge in the field of nanotoxicology about the features of the toxic effect of nano-sized MoO3 with multiple inhalation routes of entry into the body at a concentration of 1.84 mg/m3.
 
 Compliance with ethical standards. The study was carried out in accordance with the European Convention for the Protection of Vertebrate Animals used for Experimental or other Scientific Purposes (ETS No. 123) and the requirements of the Ethics Committee of the Federal Scientific Center for Medical and Preventive Technologies for Public Health Risk Management (protocol No. 6 of 20.01 .2021).

Evaluation of drinking and irrigation water quality, and potential risks indices in the Dera Ismail Khan district, Pakistan

This study sought to asses drinking and irrigation water quality in the Dera Ismail (DI) Khan District, Pakistan with the aid of using drinking water quality index (WQI) and irrigation water quality indices (IWQI). Seventy two water samples were collected from various water sources such as tube wells, dug wells, hand pumps, streams, and springs throughout the DI Khan district. The investigated physicochemical parameters include pH, TDS, EC, turbidity, total hardness, major cations (Na, K, Ca, Mg), anions (Cl, HCO3, SO4), and heavy metals (Fe, Mo, Cr, Ni, Cu, and Zn). IWQI used in the study includes Kelly's ratio (KR), permeability index (PI), sodium percent (Na%), Magnesium Hazard (MH), potential salinity (PS), residual sodium carbonate (RSC), and sodium adsorption ratio (SAR). With the mean value of 63, WQI revealed that most samples are placed in the good category, with a smaller fraction in the excellent and poor classes. On the other hand, a health risk assessment of the data pointed out that the molybdenum (Mo) and chromium (Cr) concentrations in drinking water could pose health risks to children of the concerned population. Rock weathering appears to be the dominant hydro-geochemical pathway controlling water chemistry, Ca–Mg–HCO3 being the dominant facies, followed by Na–HCO3. Kelly's ratio (KR), sodium percent (Na%), sodium adsorption ratio (SAR), and residual sodium carbonate (RSC) had values higher than the recommended threshold. The use of water for irrigation of agricultural fields may raise relevant ecological concerns in the studied district.

Metal levels in waste pickers in Brasilia, Brazil: hair and nail as exposure matrices

ABSTRACT The aim of this cross-sectional study was to compare workplace conditions and metal exposures in 431 waste pickers who worked nearby at the Estrutural Dump in Brasilia utilizing hair (n = 310) and nail (n = 355) as matrices of exposure. Waste pickers were grouped according to their workplace (open waste dump: G1 and sorting plants: G2). Hair and nail samples were collected and analyzed using ICP-MS. The work duration in the facilities was significantly different between the groups with averages of 16.46 (8.48) yrs and 9.26 (6.28) yrs for hair donors in G1 and G2, and 15.92 (7.72) yrs and 8.55 (5.77) yrs for toenail donors in G1 and G2, respectively. The arithmetic means (μg/g) of cadmium, copper, lead, and manganese in hair were significantly higher in G2 (0.076 ± 0.133; 19.61 ± 18.16; 2.27 ± .56 and 3.87 ± 5.59, respectively) compared to G1 (0.069 ± 0.235; 15.72 ± 15.18; 1.72 ± 4.04 and 3.65 ± 5.5, respectively). Concentrations of arsenic, barium, cadmium, copper, cobalt, lead, manganese, and molybdenum in nail were significantly higher in G2 (0.57 ± 0.39; 22.74 ± 42.06; 0.1 ± 0.08; 22.7 ± 51.60; 0.48 ± 0.45; 4.69 ± 9.43; 19.07 ± 20.75; 1.80 ± 1.76, respectively) compared to G1 (0.40 ± 0.28; 15.32 ± 22.31; 0.08 ± 0.11; 11.91 ± 16.25; 0.37 ± 0.37; 3.94 ± 15.04; 13.01 ± 19.08; 1.16 ± 1.80, respective. Our findings suggest that the studied population was exposed to toxic metals and indicates the need for chemical exposure prevention policies to monitor chemical risk exposures in waste pickers.

Trace Element Geochemistry in North Pacific Red Clay Sediment Porewaters and Implications for Water‐Column Studies

AbstractGeochemical analyses of trace elements in the ocean water column have suggested that pelagic clay‐rich sediments are a major source of various elements to bottom‐waters. However, corresponding high‐quality measurements of trace element concentrations in porewaters of pelagic clay‐rich sediments are scarce, making it difficult to evaluate the contributions from benthic processes to global oceanic cycles of trace elements. To bridge this gap, we analyzed porewater and bulk sediment concentrations of vanadium, chromium, cobalt, nickel, copper, arsenic, molybdenum, barium and uranium, as well as concentrations of the major oxidants nitrate, manganese, iron, and sulfate in the top 30 cm of cores collected along a transect from Hawaii to Alaska. The data show large increases in porewater concentrations of vanadium, manganese, cobalt, nickel, copper, and arsenic within the top cm of the sediment, consistent with the release of these elements from remineralized organic matter. The sediments are a sink for sulfate, uranium, and molybdenum, even though conditions within the sampled top 30 cm remain aerobic. Porewater chromium concentrations generally increase with depth due to release from sediment particles. Extrapolated to the global aerial extent of pelagic clay sediment, the benthic fluxes in mol yr−1 are Ba 3.9 ± 3.6 × 109, Mn 3.4 ± 3.5 × 108, Co 2.6 ± 1.3 × 107, Ni 9.6 ± 8.6 × 108, Cu 4.6 ± 2.4 × 109, Cr 1.7 ± 1.1 × 108, As 6.1 ± 7.0 × 108, V 6.0 ± 2.5 × 109. With the exception of vanadium, calculated fluxes across the sediment–water interface are consistent with the variability in bottom‐water concentrations and ocean residence time of the studied elements.

Rational Application of Coal Fly Ash Enhances Plant Growth and Improves Phosphorus Nutrition of Erect Milkvetch Grown on a Loess Soil

ABSTRACT Application of coal fly ash (CFA) as a soil amendment has produced great agronomic benefits. However, there are potential risks of using CFA for soil amelioration, due to the abundance of some elements, both essential and non-essential in plants, which can cause phytotoxicity and it even may cause health problems for humans through the food chain. A pot experiment was conducted to investigate the effects of various CFA application rates (5%, 10%, 20%, 40%, and 80%) on plant growth, accumulation of essential nutrient elements and potentially toxic trace elements in erect milkvetch grown on a loess soil. The results showed that plant growth was significantly enhanced by the 5%, 10%, and 20% CFA treatments, while a CFA application rate ≥ 40% did not benefit plant growth, or even considerably inhibited plant growth. Plant phosphorus nutrition was improved by CFA application, but concentrations of potassium, copper, and zinc in plants declined when CFA was applied. Concentrations of molybdenum, boron, and selenium in plants generally increased with CFA application rate. A 5% CFA application rate is appropriate for the loess soil, a higher rate will cause phytotoxicity in erect milkvetch. CFA is a promising source of nutrients such as phosphorus, rational application of CFA to soil can enhance plant growth and improve plant phosphorus nutrition.

Agro-ecological processes under conditions of biogeochemical imbalance of molybdenum in agrolandscapes of the Forest-Step zone

A special place in the theory and practice of landscape geochemistry belongs to biogeochemical zoning. Biogenic migration of substances and chemical elements can rightfully be considered one of the criteria for the typological classification of geochemical landscapes, which is the basis for building a map of geochemical landscapes of Ukraine. The scientific result of zoning is the recognition of spatial boundaries and areas of the territory consisting of connected components with uniform conditions of geochemical migration of chemical elements. With a long-term violation of the ratio between microelements, various diseases appear, which are called endemic, and the phenomenon itself — biogeochemical endemics. The latter most often occur due to a lack or excess of some threshold value of the concentration of microelements or a violation of the ratio of other micro­elements associated with it. On the basis of landscape-geochemical analysis and zoning, the authors defined the territory of the biogeochemical provinces of the Forest Steppe, where a lack of molybdenum content in the soil for normal plant development was found. In addition, the features of the molybdenum province are determined by low biogenic accumulation and intensive physicochemical dispersion of essential trace elements, increased mobility of most toxic trace elements in natural waters, and the absence of conditions for the formation of barriers of hydroamphoteric elements, including Mo2+. Also, in the territories of biogeochemical provinces, there is a high probability of the development of certain endemic phytopathologies and microelement diseases due to the imbalance of biogeochemical food chains.

Mechanism of Mo content on improving the high-temperature corrosion performance of APS sprayed Ni-clad Al coatings in simulated biomass corrosion condition

The study examined the impact of varying molybdenum content (0 %, 5 %, and 10 % wt) on the high-temperature corrosion resistance of APS-sprayed Ni-clad Al coatings. The coatings were exposed to a simulated biomass-firing environment with pure KCl deposition at 600 °C for 168 h, and a mixed gas containing 15 % water vapor was passed through. The findings revealed that increasing Mo content improved the coating's high-temperature corrosion resistance. The coating with 10 % Mo displayed a continuous layer of Ni and Al oxides on its surface, while KCl was concentrated in the Mo region. Based on the experimental results, a mechanism for how the presence of Mo element contributes to the high-temperature corrosion resistance of NiAl coatings was proposed.

Change in Mineral Status After Bariatric Surgery: a Meta-analysis.

The risk of protein and vitamin deficiencies after bariatric surgery has been well studied, but the change in mineral status has not gotten enough attention. This study aimed to perform a meta-analysis regarding the change in mineral levels after bariatric surgery and the prevalence of postoperative mineral deficiency, with subgroup analyses of different surgical procedures, study regions, and follow-up time. CENTRAL, PubMed, and EMBASE were searched for related articles. Meta-analysis, subgroup analysis, and sensitivity analysis were performed if necessary. A total of 107 articles with 47,432 patients were included. The most severe mineral deficiency after bariatric surgery was iron (20.1%), followed by zinc (18.3%), copper (14.4%), chlorine (12.2%), phosphorus (7.5%), and calcium (7.4%). Serum concentrations of potassium, sodium, selenium, manganese, and molybdenum showed no significant change before and after surgery. Subgroup analyses revealed that SG had fewer deficiencies in serum iron, calcium, zinc, magnesium, phosphorus, copper, and selenium than RYGB. OAGB showed a higher incidence of serum iron and zinc deficiencies than RYGB. Studies conducted in different regions also found various mineral statuses after surgery. Studies with follow-up ≥ 5 years had a lower prevalence of zinc, copper, and selenium deficiencies than follow-up < 5 years. A high deficiency rate of serum iron, zinc, copper, chlorine, phosphorus, and calcium was seen after bariatric surgery. The difference in surgical procedures, study regions, and follow-up time may affect postoperative mineral status; more targeted mineral supplement programs are needed considering these influencing factors.

Blood-cerebrospinal fluid barrier permeability of metals/metalloids and its determinants in pediatric patients

Concerns regarding adverse effects of metal/metalloids exposure on brain development and neurological disorders among children are increasing. However, the transport patterns of metals/metalloids across the blood-cerebrospinal fluid barrier (BCSFB) need to be clarified in children. A total of 99 Chinese pediatric patients were enrolled from February 2020 to August 2021, with a median age of 6.76 months. We detected 16 metal/metalloid levels in matched serum and cerebrospinal fluid (CSF) samples using inductively coupled plasma mass spectrometry. The BCSFB permeability of metals/metalloids were estimated and the potential effects of biomedical parameters were explored. Most metals/metalloids were detectable among > 80.0% of CSF samples. Significant correlations were observed between strontium (Sr, r = 0.46), molybdenum (Mo, r = 0.50), and cadmium (Cd, r = 0.24) concentrations in serum and CSF (P < 0.05). Ratios of metal/metalloid levels in CSF to serum (Rmetal) ranged from 0.02 to 0.74, and hazardous metals/metalloids including arsenic (As), Cd, lead (Pb), thallium (Tl), and manganese (Mn) showed high transfer efficiencies across the BCSFB (Rmetals > 0.5). With the adjustment of age and sex, albumin, β2-microglobulin, and total protein levels in CSF were positively associated with copper (Cu) permeability (FDR-adjusted P < 0.05), while glucose in CSF was negatively correlated with calcium (Ca), Cu, Sr, and Mo BCSFB permeability (FDR-adjusted P < 0.05). Q-Alb promoted Cu permeability across the BCSFB (FDR-adjusted P < 0.001), while C-reactive protein levels in serum were positively associated with selenium (Se) permeability (FDR-adjusted P = 0.046). For the first time, our findings provided data for the BCSFB permeability of 16 metals/metalloids in children, and indicated that some biomedical parameters could influence the transformation of metals/metalloids from serum to CSF. Metals/metalloids with strong BCSFB permeability warrant attention for their potential neurotoxicity.

Mycorrhizal status and host genotype interact to shape plant nutrition in field grown maize (Zea mays ssp. mays)

Arbuscular mycorrhizal fungi (AMF) establish symbioses with the major cereal crops, providing plants with increased access to nutrients while enhancing their tolerance to toxic heavy metals. However, not all plant varieties benefit equally from this association. In this study, we used quantitative trait loci (QTL) mapping to evaluate the combined effect of host genotypic variation (G) and AMF across 141 genotypes on the concentration of 20 mineral elements in the leaves and grain of field grown maize (Zea mays spp. mays). Our mapping design included selective incorporation of a castor AMF-incompatibility mutation, allowing estimation of AMF, QTL and QTLxAMF effects by comparison of mycorrhizal and non-mycorrhizal plants. Overall, AMF compatibility was associated with higher concentrations of boron (B), copper (Cu), molybdenum (Mo), phosphorus (P), selenium (Se) and zinc (Zn) and lower concentrations of arsenic (As), iron (Fe), magnesium (Mg), manganese (Mn), potassium (K) and strontium (Sr). In addition to effects on individual elements, pairwise correlation matrices for element concentration differed between mycorrhizal and non-mycorrhizal plants. We mapped 22 element QTLs, including 18 associated with QTLxAMF effects that indicate plant genotype-specific differences in the impact of AMF on the host ionome. Although there is considerable interest in AMF as biofertilizers, it remains challenging to estimate the impact of AMF in the field. Our design illustrates an effective approach for field evaluation of AMF effects. Furthermore, we demonstrate the capacity of the ionome to reveal host genotype-specific variation in the impact of AMF on plant nutrition.

Molybdenum-doped Ni–S nanostructure towards energy saving for hydrogen production coupling urea oxidation reaction

The growing trend of using energy from fossil fuel sources and the gradual reduction of these sources have caused concerns about future energy. Therefore, the need to use clean and renewable sources such as hydrogen has increased. The synthesis and design of effective electrocatalysts are important to generate hydrogen via urea electrocatalysis with the minimum required energy. In the present research, Ni–S nanostructures doped with molybdenum (Mo) supported on nickel foam substrates were synthesized by the facile one-step cyclic voltammetry (CV) method, and some of the efficient factors such as scan rate, number of cycles, and molybdenum concentration were optimized to generate the minimum required overpotential. The proposed electrode was used as a working electrode for urea-assisted electrochemical hydrogen production. The activity and electrocatalytic stability of the prepared electrodes were measured by linear sweep voltammetry (LSV), CV, Tafel polarization curve, and chronopotentiometry (CP) in 1 M NaOH + 0.33 M urea electrolyte. The results showed that the optimal electrode (50 mV/s scan rate and 10 cycles) has excellent electrocatalytic activity for hydrogen evolution reaction (HER) equal to −142.2 mV overpotential at a current density of 10 mA/cm2. In addition, the optimal electrode showed outstanding activity for the urea oxidation reaction (UOR) with a potential of 1.36 V (vs. RHE) to achieve a current density of 10 mA/cm2, which is due to the high surface-to-volume ratio, maximizing the number of active sites, good electrical conductivity, and synergistic effect of elements. On the contrary, to reach 10 mA/cm2, OER requires 1.55 (vs. RHE). In addition, an overall urea splitting cell voltage of only 2.52 and 2.76 V (vs. RHE) is needed to obtain 10 mA/cm2 current in urea and without urea-containing electrolytes, respectively. Therefore, replacing UOR with OER reduces the energy consumption of hydrogen production.

The risk of pulmonary NTM infections and water-quality constituents among persons with cystic fibrosis in the United States, 2010-2019.

The prevalence of nontuberculous mycobacterial (NTM) pulmonary disease varies geographically in the United States. Previous studies indicate that the presence of certain water-quality constituents in source water increases NTM infection risk. To identify water-quality constituents that influence the risk of NTM pulmonary infection in persons with cystic fibrosis in the United States. We conducted a population-based case-control study using NTM incidence data collected from the Cystic Fibrosis Foundation Patient Registry during 2010-2019. We linked patient zip code to the county and associated patient county of residence with surface water data extracted from the Water Quality Portal. We used logistic regression models to estimate the odds of NTM infection as a function of water-quality constituents. We modeled two outcomes: pulmonary infection due to Mycobacterium avium complex (MAC) and Mycobacterium abscessus species. We identified 484 MAC cases, 222 M. abscessus cases and 2816 NTM-negative cystic fibrosis controls resident in 11 states. In multivariable models, we found that for every 1-standardized unit increase in the log concentration of sulfate and vanadium in surface water at the county level, the odds of infection increased by 39% and 21%, respectively, among persons with cystic fibrosis with MAC compared with cystic fibrosis-NTM-negative controls. When modeling M. abscessus as the dependent variable, every 1-standardized unit increase in the log concentration of molybdenum increased the odds of infection by 36%. These findings suggest that naturally occurring and anthropogenic water-quality constituents may influence the NTM abundance in water sources that supply municipal water systems, thereby increasing MAC and M. abscessus infection risk.

FORMATION AND DECOMPOSITION OF ANOMALOUS SUPERSATURATED MOLYBDENUM SOLUTIONS IN COPPER-BASED CONDENSATES

&#x0D; Cu-Mo condensates in the concentration range of the latter from 0.3 to 1.5 at.%, obtained by simultaneous evaporation in vacuum with subsequent condensation of the resulting vapor mixture on a non-orienting substrate (PVD method), were studied. The components of this system do not form chemical compounds under equilibrium conditions and are mutually insoluble in liquid and solid states. The structure of Cu-Mo condensates was studied by transmission electron microscopy and X-ray diffractometry both in the derivative state and after a series of isothermal anneals in the temperature range from 300 to 900°C. It was found that small concentrations of molybdenum lead to significant dispersion of the matrix metal. Molybdenum tends to form segregations at the boundaries of copper grains and form a strong coherent bond with the matrix metal, which persists even after isothermal annealing. The conditions for the formation of an anomalous supersaturated solid solution of molybdenum in the copper matrix, as well as the conditions for its decomposition, have been revealed. An assumption is made about the mechanism of formation of such a solution during condensation from the vapor phase, which consists in the kinetic capture of molybdenum atoms by the crystallization front during condensation from the vapor phase. It was found that the decomposition of the supersaturated solid solution begins when heated to 0.5 of the melting point of copper and is accompanied by a dispersion solidification process. During the experiment, it was first recorded that the dispersion solidification process can have a two-stage character. The first peak is observed in the region of 30 minutes of annealing, and the second peak is observed after about 2 hours of isothermal annealing. The height of the dispersion hardening peaks increases with increasing molybdenum concentration. It is suggested that the appearance of the second peak of dispersion hardening is associated with the peculiarities of the interaction between copper grains and molybdenum segregations at the grain boundaries. It is shown that the structure after solution decomposition is typically composite. The advantage of this material over conventional dispersively hardening alloys is the fact that in these pseudo-alloys there is no reverse solution of hardening particles at an increase in temperature.

Thermal, Mechanical, and Electrochemical Characterization of Ti50Ni50−XMox Alloys Obtained by Plasma Arc Melting

This study aims to manufacture and characterize titanium and nickel alloys with different molybdenum (Ti–Ni–Mo) contents, focusing on the influence of these additions on the microstructure, mechanical properties, and corrosion resistance. The relevance of this work stems from the lack of research on this specific alloy and the absence of reports in the literature with molybdenum percentages above 2 at.%. Ti50Ni50−XMox alloys were produced by the plasma arc melting method, with six different compositions (x = 0, 0.5, 1, 2, 3, and 4 at.% Mo), and a comprehensive analysis of microstructure, chemical composition, thermal, mechanical, and electrochemical properties was carried out. The results demonstrated significant alterations in the microstructure of the Ni–Ti alloy with the addition of molybdenum presenting several phases, precipitates (TiNi, Ti2Ni), and oxides (Ti4Ni2O, TiO, and TiO3). The stability of the B2 phase increased with molybdenum content, and the monoclinic martensite (B19′) phase was identified only in the Ni–Ti sample. Introducing molybdenum into the Ni–Ti alloy generated the R-phase and shifted the phase transformation peaks to lower temperatures, as differential scanning calorimetry (DSC) indicated. Microhardness and elastic modulus decreased with increasing Mo content, ranging from 494 HV to 272 HV and 74 GPa to 63 GPa, respectively. Corrosion tests revealed increased corrosion resistance with increasing Mo content, reaching a polarization resistance of 2710 kΩ·cm2 and corrosion current of 11.3 µA. Therefore, this study points to Ti–Ni–Mo alloys as potential candidates to increase the range of Ni–Ti alloy applications, mainly in biomaterials, reinforcing its relevance and need in current alloy research.

Increasing corrosion resistance of Ni-Mo composite electrodeposited coatings: Doping with boron

Corrosion-resistant Ni-Mo-B electrode posited coatings were obtained. Corrosion resistance of these coatings compared to Ni and Ni-Mo increased by ∼ 6.0 and ∼ 2.0 times, respectively. Increasing the boron content in the Ni-Mo-B coating had almost no effect on its corrosion resistance in this environment. The reduction of the corrosion rate was associated with the formation of a specific surface morphology – large, irregularly oval crystal aggregates that eliminated internal stresses and cracks caused by high molybdenum content.

Relationship of individual and mixed urinary metals exposure with liver function in the China National Human Biomonitoring (CNHBM) of Zhejiang Province

BackgroundHeavy metals have been reported to affect liver function. However, there is currently little and inconsistent knowledge about the effects of combined and individual urinary metals on specific parameters of liver function in the general population. Therefore, this study aimed to investigate their associations. MethodsThis study involved 807 general population from the China National Human Biomonitoring of Zhejiang Province 2017–2018. Concentrations of urinary metals, including Chromium (Cr), Cobalt (Co), Nickle (Ni), Arsenic (As), Selenium (Se), Molybdenum (Mo), Cadmium (Cd), Thallium (Tl) and Lead (Pb) were measured. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), total protein (TP), albumin (ALB), direct bilirubin (DBIL), total bilirubin (TBIL) as liver function biomarkers. Multivariable linear regression and weighted quantile sum (WQS) regression were employed to explore the associations of urinary metals with liver function biomarkers. Subgroup analysis stratified by gender and age, excluding smokers and drinkers for sensitivity analysis. ResultsBoth statistical models indicated that urinary metals were positively associated with ALT and AST, while negatively with TP, ALB, DBIL and TBIL. In the WQS analysis, each quartile increase in the ln-transformed levels of metal mixtures was associated with 4.11 IU/L (95% CI: 1.07, 7.15) higher ALT and 3.00 IU/L (95% CI: 1.75, 4.25) higher AST, as well as, with 0.67 g/L (95% CI: 1.24, −0.11) lower TP, 0.74 g/L (95% CI: 1.09, −0.39) lower ALB, 0.38 μmol/L (95% CI: 0.67, −0.09) lower DBIL, and 1.56 μmol/L (95% CI: 2.22, −0.90) lower TBIL. The association between urinary metals and ALT was primarily driven by Cd (55.8%), Cr contributed the most to the association with AST (20.2%) and TBIL (45.2%), while the association with TP was primarily driven by Ni (38.2%), the association with ALB was primarily driven by As (32.8%), and the association with DBIL was primarily driven by Pb (30.9%). The associations between urinary metals and liver function might differ by sex and age. ConclusionUrinary metals were significantly associated with liver function parameters. Further studies are required to clarify the relationship between heavy metals and liver function.

Influence of molybdenum concentration on the microstructure and nanotribological properties of diamond-like carbon films

Influence of molybdenum concentration on the microstructure and nanotribological properties of diamond-like carbon films

Reference intervals for trace mineral and heavy metal concentrations in horse livers in the Netherlands.

We determined reference intervals (RIs) for concentrations of trace minerals and toxic elements based on liver samples from 122 apparently healthy horses at 2 slaughter facilities in the Netherlands. Samples were collected during the spring and fall of 2021, and the sex and age of the horses were registered upon sampling. Concentrations of arsenic, cadmium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel, selenium, vanadium, and zinc were measured in liver samples using inductively coupled plasma-mass spectrometry (ICP-MS) after nitric acid digestion. RIs were calculated using Reference Value Advisor software. The concentrations of most elements were not significantly different between sexes or in different seasons. Cadmium concentrations were higher than the European maximum residue limit of 2 mg/kg DW in 89% of livers. Positive significant correlations were observed between some elements (iron, molybdenum, lead, vanadium), and significant negative correlations between others (manganese, iron).

Design of Highly Efficient Nickel-Cobalt-Manganese-Molybdenum (NCMM) Nano-Catalysts Supported on Activated Carbon for Desulfurization Process

To maintain a healthy environment and way of life in the modern world, clean fuel must be produced. It is important to totally and successfully remove sulfur-containing harmful compounds from fuel oil in order to comply with the new sulfur legislation. Numerous methods have been proposed in the literature for desulfurizing fuel oil. In this study, activated carbon (AC), which is regarded as a significant porous material, is derived from agro-wastes such as apricot shells (AS) and is loaded with different combinations of active metals. Nickel–Cobalt–Manganese (NCM) over AC is firstly prepared and evaluated experimentally. Then, several concentrations of Molybdenum (1%, 2% and 3%) are separately added to NCM to generate three novel composite mesoporous nano-catalysts (NCMM_1, NCMM_2 and NCMM_3). Several tests have been carried out to determine the catalysts’ properties, such as BETsurface area, pore volume, FTIR, TGA and SEM, XRF and XRD. These catalysts are then used in the batch oxidative desulfurization process to remove sulfur compounds from wide cut oil (from IBP to 345 °C). The pilot plant conditions were as follows: air flow rate = 120 L/h, reaction temperature = 363 K and reaction time of 1 h for all catalysts. Remarkable characteristics have been noticed, and it was discovered that the nano-catalyst NCMM_2 performed better in terms of degree of sulfur removal compared to other nano-catalysts.