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chromium - Top 30 Publications

Potential presence of metals in patients treated with metal-metal coupling prostheses for hip arthroplasty at 7 and 10 years of follow-up.

Beginning in 2008, metal-on-metal prostheses have been in the spotlight owing to much higher revision rates than expected. Adverse local tissue reactions have been well described in the literature as potential complications.

Do screws and screw holes affect osteolysis in cementless cups using highly cross-linked polyethylene? A 7 to 10-year follow-up case control study.

The use of screws and the presence of screw holes may cause acetabular osteolysis and implant loosening in cementless total hip arthroplasty (THA) using conventional polyethylene. In contrast this issue is not fully understood using highly cross-linked polyethylene (HXLPE), particularly in large comparative study. Therefore, we performed a case-control study to assess the influence of screw usage and screw holes on: (1) implant fixation and osteolysis, and (2) polyethylene steady-state wear rate, using cases with HXLPE liners followed up for 7-10 years postoperatively.

Trivalent chromium incorporated in a crystalline calcium phosphate matrix accelerates materials degradation and bone formation in vivo.

Remodeling of calcium phosphate bone cements is a crucial prerequisite for their application in the treatment of large bone defects. In the present study trivalent chromium ions were incorporated into a brushite forming calcium phosphate cement in two concentrations (10 and 50 mmol/mol β-tricalcium phosphate) and implanted into a femoral defect in rats for 3 and 6 month, non-modified brushite was used as reference. Based on our previous in vitro findings indicating both an enhanced osteoclastic activity and cytocompatibility towards osteoprogenitor cells we hypothesized a higher in vivo remodeling rate of the Cr3+ doped cements compared to the reference. A significantly enhanced degradation of the chromium modified cements was evidenced by micro computed tomography, x-ray and histological examinations. Furthermore the formation of new bone tissue after 6 month of implantation was significantly increased from 29% to 46% during remodeling of cements, doped with the higher Cr3+ amount. Time of flight secondary ion mass spectrometry (ToF-SIMS) of histological sections was applied to investigate the release of Cr3+ ions from the cement after implantation and to image their distribution in the implant region and the surrounding bone tissue. The relatively weak incorporation of chromium into the newly formed bone tissue is in agreement to the low chromium concentrations which were released from the cements in vitro. The faster degradation of the Cr3+ doped cements was also verified by ToF-SIMS. The positive effect of Cr3+ doping on both degradation and new bone formation is discussed as a synergistic effect of Cr3+ bioactivity on osteoclastic resorption on one hand and improvement of cytocompatibility and solubility by structural changes in the calcium phosphate matrix on the other hand.

Protective role of selenium against chromium stress involving metabolites and essential elements in Brassica juncea L. seedlings.

The present study aimed at the potential role of selenium in providing protection to plants subjected to chromium toxicity. The study was carried out on 15-day-old seedlings of Brassica juncea raised in the solutions of Cr (300 µM) and Se (2, 4 and 6 µM), both alone and in combinations under controlled laboratory environment. The effects were studied on growth, plant metabolites (involved in osmotic homeostasis and stress protection), and essential elements. The results showed that the exposure of B. juncea seedlings to 300 µM Cr led to an increase in the contents of total sugars, reducing sugars, non-reducing sugars, total phenols and flavonoids. However, a significant decline in growth characteristics, the contents of proteins and free amino acids was observed. The essential elements (Na, K, Ca, Mg, C, H, N) also decreased in response to Cr. Se application in binary combinations, on the other hand, aided in improving seed germination (19%), root (88.3%) and shoot (18.2%) lengths. It also helped to increase the contents of sugars [total (16.3%), reducing (21.6%) and non-reducing (15.2%)], phenols (36.7%) and flavonoids (27.4%), thereby aiding in alleviating the phytotoxicity of Cr. The profiling of polyphenols and amino acids, and histological study of phenols supported the above results. The contents of essential elements also showed a significant increase, while Cr uptake was observed to decline by Se supplementation. The observations from the present study indicate that Se has the ability to influence primary and secondary metabolism, improve mineral nutrition and reduce Cr uptake in B. juncea seedlings to combat the Cr phytotoxicity and enhance the tolerance against stress.

In situ monitoring of the Sinos River, southern Brazil: water quality parameters, biomarkers, and metal bioaccumulation in fish.

The Sinos River is an important water supply in Southern Brazil and receives industrial, agricultural, and domestic effluents which may affect aquatic biota. Water physicochemical and microbiological analyses, biomarker responses (scaled mass index (SMI), gill histopathology, and micronucleus and nuclear abnormality (MN and NA) frequencies), and metal bioaccumulation in muscle were assessed in the fish species Bryconamericus iheringii (Characidae) captured at three sampling sites (S1, S2, and S3) in four sampling periods. The mean values of five parameters (total phosphorus, thermotolerant coliforms, aluminum, iron, and lead) exceeded the limits established by the Brazilian legislation at the three sampling sites. Although physicochemical analysis indicated higher impacts at S3, in some samples, significantly higher MN frequencies and bioaccumulation of manganese in fish muscle were observed at S1, whereas low SMI and higher concentrations of aluminum and zinc in fish muscle were found at S2. Histopathological alterations in gills were observed in fish collected at the three sampling sites; however, no spatial differences were observed, indicating similar environmental conditions with respect to this biomarker. Moreover, temporal variation of biomarker responses and metal bioaccumulation were found at all sampling sites. Furthermore, the consumption of fish from the Sinos River should be avoided given the concentrations of chromium (all samples), cadmium, and lead in fish muscle above the threshold for safe human consumption.

Phyto-management of chromium contaminated soils through sunflower under exogenously applied 5-aminolevulinic acid.

Soil contamination with heavy metals is threatening the food security around the globe. Chromium (Cr) contamination results in poor quality and reduction in yield of crops. The present research was performed to figure out the Cr toxicity in sunflower and the ameliorative role of 5-aminolevulinic acid (ALA) as a plant growth regulator. The sunflower (FH-614) was grown under increasing concentration of Cr (0, 5, 10 and 20mgkg-1) alone and/or in combination with 5-ALA (0, 10 and 20mgL-1). Results showed that Cr suppressed the overall growth, biomass, gas exchange attributes and chlorophyll content of sunflower plants. Moreover, lower levels of Cr (5 and 10mgkg-1) increased the production of reactive oxygen species (ROS) and electrolyte leakage (EL) along with the activities of antioxidant enzymes i.e., superoxide dismutase (SOD), guaiacole peroxidase (POD), ascorbate (APX), catalase (CAT). But at higher concentration of Cr (20mgkg-1), the activities of these enzymes presented a declining trend. However, the addition of 5-ALA significantly alleviated the Cr-induced toxicity in sunflower plant and enhanced the plant growth and biomass parameters along with increased chlorophyll content, gas exchange attributes, soluble proteins and soil plant analysis development (SPAD) values by scavenging the ROS and lowering down the EL. The 5-ALA also enhanced the activities of antioxidant enzymes at all levels of Cr. The increase in Cr concentration in all plant parts such as leaf, root and stem was directly proportional to the Cr concentration in soil. The application of 5-ALA further enhanced the uptake of Cr and its concentration in the plants. To understand this variation in response of plants to 5-ALA, detailed studies are required on plant biochemistry and genetic modifications.

Dietary Chromium Picolinate Supplementation Affects Growth, Whole-Body Composition, and Gene Expression Related to Glucose Metabolism and Lipogenesis in Juvenile Blunt Snout Bream, Megalobrama amblycephala.

An 11-week feeding trial was carried out to investigate the effects of supplemented chromium picolinate (Cr-Pic) on the growth, whole-body composition, and relative mRNA expression related to lipogenesis and glucose metabolism in juvenile blunt snout bream. Seven isonitrogenous and isoenergetic diets with graded Cr supplementation levels were fed to triplicate groups. The final weight (FW), feed conversion ratio (FCR), and specific growth rate (SGR) were improved with increasing dietary Cr supplementation levels up to 0.4 mg/kg, and thereafter showed relatively constant. However, 12.0 mg/kg dietary Cr supplementation decreased growth and feed utilization. Based on SGR and FCR, the optimal dietary Cr supplementation level for the juvenile was estimated to be 0.28 mg/kg. Significantly higher plasma insulin levels were found in juvenile fed diets with 0.4 and 0.8 mg/kg Cr supplementation compared to those fed diet sans supplemented Cr. Plasma glucose levels decreased with increasing dietary Cr supplementation, and the lowest value was remarked in the group added 3.2 mg/kg of Cr. Adding 0.4-0.8 mg/kg Cr enhanced insulin receptor substrate 1 (IRS-1), phosphoinositide-3-kinase (PI3K), and pyruvate kinase (PK) and inhibited expression of phosphoenolpyruvate carboxykinase (PEPCK), glucose-6-phosphatase (G6Pase), and glycogen synthase (GS) mRNA levels. High dietary Cr (12.0 mg/kg) supplementation resulted in high G6Pase and PEPCK expression. The highest content of whole-body lipid was remarked in fish fed with 0.4 mg/kg dietary Cr, which related to the enhanced gene expression related to lipogenesis; thereafter, mRNA levels showed a diminishing trend. These findings indicate that optimum dietary Cr-Pic supplementation has a positive effect on growth and blood glucose homeostasis by modifying the mRNA levels related to glucose metabolism and lipogenesis in juvenile blunt snout bream.

The Effect of Alternative Bearing Surfaces on the Risk of Revision Due to Infection in Minimally Stabilized Total Knee Replacement: An Analysis of 326,603 Prostheses from the Australian Orthopaedic Association National Joint Replacement Registry.

The effect of alternative bearing materials on the risk of revision due to infection after total knee replacement remains uncertain. By reducing the immunomodulating polyethylene wear-particle burden and with different substrate bacterial adhesion properties, Oxinium oxidized zirconium and cross-linked polyethylene (XLPE) could alter infection risk. The purpose of the current study was to analyze the risk of revision for infection in 3 comparisons of bearing combinations.

False-positive result when a diphenylcarbazide spot test is used on trivalent chromium-passivated zinc surfaces.

A colorimetric 1,5-diphenylcarbazide (DPC)-based spot test can be used to identify hexavalent chromium on various metallic and leather surfaces. DPC testing on trivalent chromium-passivated zinc surfaces has unexpectedly given positive results in some cases, apparently indicating the presence of hexavalent chromium; however, the presence of hexavalent chromium has never been confirmed with more sensitive and accurate test methods.

Comparative Proteomics of Chromium-Transformed Beas-2B Cells by 2D-DIGE and MALDI-TOF/TOF MS.

Chromium (Cr) is a highly toxic, common heavy metal used in industrial production. There are two types of Cr in nature: hexavalent chromium (Cr(VI)) and chromium trichloride (Cr(III)). Cr(III) is involved in the metabolism of sugars and lipids, whereas Cr(VI) is absorbed through the respiratory tract and skin and generates free radicals that result in secondary toxicity. Cr(VI) leads to cancer in the occupational population and is therefore recognized as a human carcinogen by the International Agency for Research on Cancer. The specific mechanism underlying Cr-induced carcinogenesis is complex. In this study, two-dimensional fluorescence difference gel electrophoresis and matrix-assisted laser desorption ionization-time-of-flight/time-of-flight mass spectrometry-based techniques were performed to analyze differentially expressed proteins between Beas-2B human bronchial epithelial cells and Cr(VI)-transformed Beas-2B cells. Many differentially expressed proteins were identified in the cells after malignant transformation, including serine/threonine kinase 11, endothelial nitric oxide synthase 3, apolipoprotein A1, vinculin, and lamin A/C. These proteins are involved in many signaling and metabolic pathways, including apoptosis, autophagy, the PI3K/Akt signaling pathway, focal adhesion, cell motility, and actin cytoskeleton rearrangement.

The evaluation of Cr-curcumin-DNA complexation by experimental and theoretical approaches.

Chromium(III) chloride mediates DNA-DNA cross-linking. Some chromium complexes promote programmed cell death in specific ligand environment through binding to DNA. One strategy that can be supposed for reduction of Cr3+ binding affinity to DNA is using curcumin as a chelator. In the current study, the [Cr(Curcumin)(EtOH)2](NO3)2 (CCC) was synthesized and characterized by UV/Vis, FT-IR, CHN and spectrophotometric titration techniques. The mole ratio plot revealed a 1:1 complex between Cr3+ and curcumin in solution. Binding interaction of this complex with calf thymus-DNA (CT-DNA) was investigated using UV/Vis, circular dichroism (CD), FT-IR and cyclic voltammetry. The intrinsic binding constants of CCC with DNA, measured by UV/Vis and cyclic voltammetry, were 1.60 × 105 and 1.13 × 105, respectively. The thermodynamic studies showed that the reaction is enthalpy and entropy favoured. CD analysis revealed that only Λ-CCC interacts with DNA and Δ-CCC form has no tendency towards DNA. Based on FT-IR studies, it was understood that CCC interacts with DNA via minor groove binding. The docking simulation was carried out for finding the binding mode of CCC to DNA, too. All of data demonstrated that the curcumin significantly reduced the affinity of Cr3+ to the DNA and the form of Δ-CCC has no interaction with DNA.

The effects of low levels of trivalent ions on a standard strain of Escherichia coli (ATCC 11775) in aqueous solutions.

Considering the ever-growing usage of trivalent salts in water treatment, for example, lanthanum salts in rare earth, AlCl3 and FeCl3 , the effects of different trivalent cations on the bacterium Escherichia coli (E. coli) ATCC 11775 strain have been studied in aqueous solutions. From colony incubation studies, the colony-forming unit (CFU) densities were found to decrease significantly in the presence of even low levels (10-5  mol/L) of lanthanum chloride. This level of reduction in CFU number is comparable to the results obtained using the known bacteriocidal cationic surfactant, C14 TAB. By comparison, exposure of the cells to low levels of trivalent ion, aluminum and chromium ion solutions produced only modest reductions in CFU density. The results from the incubation studies suggest that the bacteriostatic mechanism of La3+ ions has similarities to that of the cationic surfactant, and different to that of the other trivalent ions. Size distribution and zeta potential measurements of E. coli cells and phospholipid vesicles in the presence of trivalent cations solutions suggested significant cell shrinkage probably caused by membrane disruption.

First heating measurements of endovascular stents in magnetic particle imaging.

Magnetic Particle Imaging (MPI) is a three-dimensional imaging method which visualizes the spatial distribution of Superparamagnetic Iron Oxide Nanoparticles (SPIOs) with oscillating and static magnetic fields. It is a quantitative method as the intensity of its signal is proportional to the concentration of the SPIOs. Due to its quantitativeness, high temporal resolution and kidney-safe tracers it is proposed to be a very promising noninvasive method for cardiovascular imaging. In this regard MPI in the presence of endovascular stents and assessment of stent patency with MPI has to be evaluated. The purpose of this study was to evaluate the heating of endovascular stents due to the alternating magnetic fields as a safety aspect of MPI. Twenty one commercially available endovascular stents of different sizes (diameter: 3, 3.5, 4, 5, 6, 7, 8, 10 mm, length: 11 - 99 mm) and materials (stainless steel, nitinol, platinum-chromium, cobalt-chromium) were evaluated. They were implanted in silicone tubes matching the stent diameter and placed at the center of the bore of a preclinical MPI scanner (Bruker-Biospin, Ettlingen, Germany). The temperature was measured with fiber optic thermometers over a scan duration of 431 seconds. A temperature change of ≥ 0.1 K (absolute accuracy of the temperature measurement) was defined as heating of the material. Nine stents showed no heating. 12 stents showed heating of at least 0.1 K. Only 5 stents showed heating of more than 3.0 K, all equal or larger than 6 mm. The largest temperature difference was 12.4 K, corresponding to the stent with the highest diameter (10 mm). The only predictor of the heating behavior was the stent diameter. The stent material had no measurable effect on the heating behavior. With few exceptions, the safe use of endovascular stents in MPI is possible. It has to be further evaluated if the increase of temperature of stents with a larger diameter is still measurable under (blood) flow-conditions and thus relevant in vivo.

Callitriche cophocarpa (water starwort) proteome under chromate stress: evidence for induction of a quinone reductase.

Chromate-induced physiological stress in a water-submerged macrophyte Callitriche cophocarpa Sendtn. (water starwort) was tested at the proteomic level. The oxidative stress status of the plant treated with 1 mM Cr(VI) for 3 days revealed stimulation of peroxidases whereas catalase and superoxide dismutase activities were similar to the control levels. Employing two-dimensional electrophoresis, comparative proteomics enabled to detect five differentiating proteins subjected to identification with mass spectrometry followed by an NCBI database search. Cr(VI) incubation led to induction of light harvesting chlorophyll a/b binding protein with a concomitant decrease of accumulation of ribulose bisphosphate carboxylase (RuBisCO). The main finding was, however, the identification of an NAD(P)H-dependent dehydrogenase FQR1, detectable only in Cr(VI)-treated plants. The FQR1 flavoenzyme is known to be responsive to oxidative stress and to act as a detoxification protein by protecting the cells against oxidative damage. It exhibits the in vitro quinone reductase activity and is capable of catalyzing two-electron transfer from NAD(P)H to several substrates, presumably including Cr(VI). The enhanced accumulation of FQR1 was chromate-specific since other stressful conditions, such as salt, temperature, and oxidative stresses, all failed to induce the protein. Zymographic analysis of chromate-treated Callitriche shoots showed a novel enzymatic protein band whose activity was attributed to the newly identified enzyme. We suggest that Cr(VI) phytoremediation with C. cophocarpa can be promoted by chromate reductase activity produced by the induced quinone oxidoreductase which might take part in Cr(VI) → Cr(III) bioreduction process and thus enable the plant to cope with the chromate-generated oxidative stress.

Environmentally available hexavalent chromium in soils and sediments impacted by dispersed fly ash in Sarigkiol basin (Northern Greece).

Hexavalent chromium is one of the most toxic and carcinogenic species known and can be released into the environment from several sources. In Sarigkiol basin (N Greece) the presence of Cr(VI) in soil, sediments and groundwater may originate from both natural (ophiolitic rocks and their weathering products) and anthropogenic (dispersed fly ash produced from lignite power plants) sources. In this study, the distribution of contents and origin of environmentally available Cr(VI) in soils, sediments, regoliths and fly ash of Sarigkiol basin is presented. Detailed geochemical and mineralogical studies were performed on soil samples (up to 1 m) and regoliths, while leaching tests were also applied to fresh and old fly ash samples. Leachable chromium from soil and sediment samples generally increased with depth and the highest concentrations were observed near to the power plant of Agios Dimitrios. The speciation of chromium in leachates revealed that Cr(VI) concentrations accounted for more than 96% of total Cr. Leaching tests of regoliths established that the natural contribution of Cr(VI) is up to 14 μg kg-1. Therefore, the measurement of higher concentrations (up to 80 μg kg-1) of environmentally available Cr(VI) in soils and sediments can be attributed to the impact/presence of dispersed fly ash in the soils and sediments of the same area. This was also supported by the low correlation recorded between environmentally available chromium and Cr-bearing minerals (mainly serpentine and talc). The influenced zone is located in the eastern part of the basin near the local power plant and surrounds an open conveyor belt that transfers fly ash to an open temporary storage pit. This zone overlies an unconfined porous aquifer thus explaining the elevated concentrations of Cr(VI) in groundwater (up to 120 μg L-1) previously reported in this area.

Metal Concentrations in Tissues of Gadwall and Common Teal from Miankaleh and Gomishan International Wetlands, Iran.

Miankaleh and Gomishan International Wetlands are important wintering areas for waterbirds in the Caspian Sea region. Previous studies revealed increased exposure to metals in some species of waterbirds using these wetlands. In this study, we examined concentrations of cadmium (Cd), chromium (Cr), iron (Fe), lead (Pb), and zinc (Zn) in kidneys, liver, and pectoral muscle of wintering Gadwall (Anas strepera) and Common Teal (Anas crecca) collected in 2012. In addition, we measured concentrations of these elements in water and sediments from the collection sites. The genders differed in only one element/tissue combination, i.e., concentrations of Fe were greater in the livers of males. Concentrations of elements observed in Gadwall were generally higher than in Common Teal; only renal Cr and muscle Zn did not differ between species. Mean Cd concentrations in Gadwall exceeded background levels, reaching 1.94 μg/g ww in kidneys and 1.09 μg/g ww in liver. Similarly, Pb concentrations in Gadwall were also elevated (4.14 μg/g ww in kidneys, 3.22 μg/g ww in liver). Concentrations of other metals were within ranges commonly found in waterfowl. Concentrations of elements in the environment were elevated above background and comparable with the data obtained for this region by other scientists. However, these levels were deemed to not be great enough to pose an acute health risk to waterfowl. Given increased concentrations of some metals in duck tissues, further inquiry into the source of the exposure is needed for this area.

Environmental Influences on the Epigenome: Exposure-Associated DNA Methylation in Human Populations.

DNA methylation is the most well studied of the epigenetic regulators in relation to environmental exposures. To date, numerous studies have detailed the manner by which DNA methylation is influenced by the environment, resulting in altered global and gene-specific DNA methylation. These studies have focused on prenatal, early-life, and adult exposure scenarios. The present review summarizes currently available literature that demonstrates a relationship between DNA methylation and environmental exposures. It includes studies on aflatoxin B1, air pollution, arsenic, bisphenol A, cadmium, chromium, lead, mercury, polycyclic aromatic hydrocarbons, persistent organic pollutants, tobacco smoke, and nutritional factors. It also addresses gaps in the literature and future directions for research. These gaps include studies of mixtures, sexual dimorphisms with respect to environmentally associated methylation changes, tissue specificity, and temporal stability of the methylation marks. Expected final online publication date for the Annual Review of Public Health Volume 39 is April 1, 2018. Please see for revised estimates.

Non-diffracting beams for label-free imaging through turbid media.

We propose a new method to image through dynamically changing turbid media based on the scanning of non-diffractive laser beams. We use computer-generated holograms to create Airy beams and compare quantitatively the characteristics of their propagation in clear and turbid media. Imaging contrast is achieved by relative reflection of the scanned beams from the imaged surface. We implement our method to demonstrate experimentally our ability to image a chromium surface on a glass slide through 270 μm of highly scattering milk/water mixtures with a resolution of several microns.

Evaluation of water quality and human risk assessment due to heavy metals in groundwater around Muledane area of Vhembe District, Limpopo Province, South Africa.

Groundwater is considered as good alternative to potable water because of its low turbidity and perceived low contamination. The study assessed the physio-chemical and heavy metals concentrations in eight randomly selected boreholes water at Muledane village in Limpopo Province of South Africa and the results were compared with South African National standard permissible limit. The impacts of heavy metals on human health was further determined by performing quantitative risk assessment through ingestion and dermal adsorption of heavy metals separately for adults and children in order to estimate the magnitude of heavy metals in the borehole samples. Parameters such as turbidity, nitrate, iron, manganese and chromium in some investigated boreholes did not comply with standard limits sets for domestic water use. Multivariate analyses using principal component analysis and hierarchical cluster analysis revealed natural and anthropogenic activities as sources of heavy metal contamination in the borehole water samples. The calculated non-carcinogenic effects using hazard quotient toxicity potential, cumulative hazard index and chronic daily intake of groundwater through ingestion and dermal adsorption pathways were less than a unity, which showed that consumption of the water could pose little or no significant health risk. However, maximum estimated values for an individual exceeded the risk limit of 10-6 and 10-4 with the highest estimated carcinogenic exposure risk (CRing) for Cr and Pb in the groundwater. This could pose potential health risk to both adults and children in the investigated area. Therefore, precaution needs to be taken to avoid potential CRing of people in Muledane area especially, children using the borehole water.

A green method to leach vanadium and chromium from residue using NaOH-H2O2.

Hydrogen peroxide as an oxidant was applied in leaching of vanadium and chromium in concentrated NaOH solution. Under the optimal reaction conditions (the liquid to solid ratio of 4.0 ml/g, residue particle size of <200 mesh, the mass ratio of NaOH-to-residue of 1.0 g/g, the volume ratio of H2O2-to-residue of 1.2 ml/g, reaction temperature of 90 °C and reaction time of 120 min), the leaching efficiency of vanadium and chromium could reach up to 98.60% and 86.49%, respectively. Compared with the current liquid-phase oxidation technologies, the reaction temperature was 90-310 °C lower, and the NaOH concentration of the reaction medium is lower by more than 50 wt% (the mass ratio of NaOH-to-residue of 1.0 g/g equals to concentration of 20 wt%). The kinetics study revealed that leaching process of chromium and vanadium were interpreted with shrinking core model under chemical reaction control. The apparent activation energy of chromium and vanadium dissolution was 22.19 kJ/mol and 6.95 kJ/mol, respectively.

Randomized comparison of novel biodegradable polymer and durable polymer-coated cobalt-chromium sirolimus-eluting stents: Three-Year Outcomes of the I-LOVE-IT 2 Trial.

We aimed to compare the long-term outcomes of the novel biodegradable polymer cobalt-chromium sirolimus-eluting stent (BP-SES) versus the durable polymer sirolimus-eluting stent (DP-SES) in the I-LOVE-IT2 trial.

Chromium(III) release from chromium-tanned leather elicits allergic contact dermatitis: a use test study.

Chromium (Cr) is a common skin sensitizer. The use of Cr(VI) in leather is restricted in the EU, but that of Cr(III) is not.

Toxicity of formulants and heavy metals in glyphosate-based herbicides and other pesticides.

The major pesticides of the world are glyphosate-based herbicides (GBH), and their toxicity is highly debated. To understand their mode of action, the comparative herbicidal and toxicological effects of glyphosate (G) alone and 14 of its formulations were studied in this work, as a model for pesticides. GBH are mixtures of water, with commonly 36-48% G claimed as the active principle. As with other pesticides, 10-20% of GBH consist of chemical formulants. We previously identified these by mass spectrometry and found them to be mainly families of petroleum-based oxidized molecules, such as POEA, and other contaminants. We exposed plants and human cells to the components of formulations, both mixed and separately, and measured toxicity and human cellular endocrine disruption below the direct toxicity experimentally measured threshold. G was only slightly toxic on plants at the recommended dilutions in agriculture, in contrast with the general belief. In the short term, the strong herbicidal and toxic properties of its formulations were exerted by the POEA formulant family alone. The toxic effects and endocrine disrupting properties of the formulations were mostly due to the formulants and not to G. In this work, we also identified by mass spectrometry the heavy metals arsenic, chromium, cobalt, lead and nickel, which are known to be toxic and endocrine disruptors, as contaminants in 22 pesticides, including 11 G-based ones. This could also explain some of the adverse effects of the pesticides. In in vivo chronic regulatory experiments that are used to establish the acceptable daily intakes of pesticides, G or other declared active ingredients in pesticides are assessed alone, without the formulants. Considering these new data, this assessment method appears insufficient to ensure safety. These results, taken together, shed a new light on the toxicity of these major herbicides and of pesticides in general.

Microfluidic Paper-based Analytical Device for the Determination of Hexavalent Chromium by Photolithographic Fabrication Using a Photomask Printed with 3D Printer.

This article describes a simple and inexpensive microfluidic paper-based analytical device (μPAD) for the determination of hexavalent chromium (CrVI) in water samples. The μPADs were fabricated on paper by photolithography using a photomask printed with a 3D printer and functionalized with reagents for a colorimetric assay. In the μPAD, CrVI reacts with 1,5-diphenylcarbazide to form a violet-colored complex. Images of μPADs were captured with a digital camera; then the red, green, and blue color intensity of each detection zone were measured using images processing software. The green intensity analysis was the best sensitive among the RGB color. A linear working range (40 - 400 ppm; R2 = 0.981) between the CrVI and green intensity was obtained with a detection limit of 30 ppm. All of the recoveries were between 94 and 109% in recovery studies on water samples, and good results were obtained.

A Limited Survey of Metal Content in Blue Jack Mackerel ( Trachurus picturatus) Obtained from Markets in the Canary Islands.

The levels of 20 metals (aluminum, boron, barium, calcium, cadmium, cobalt, chromium, copper, iron, potassium, lithium, magnesium, manganese, molybdenum, sodium, nickel, lead, strontium, vanadium, and zinc) were analyzed in muscle and liver tissue of Trachurus picturatus marketed in the Canary Islands (Spain) by using inductively coupled plasma optical emission spectrometry. In the liver samples, the mean concentrations in milligrams per kilogram wet weight (wt) of Al (14.7), B (0.99), Ba (1.64), Ca (314), Cd (2.52), Co (0.15), Cu (4.07), Fe (106), Li (3.89), Mn (0.85), Mo (0.16), Na (1510), Ni (0.51), Pb (0.36), Sr (3.54), V (0.78), and Zn (23.13) were higher than those detected in the muscle samples in milligrams per killogram wet wt, which were as follows: Al (8.76), B (0.07), Ba (0.30), Ca (210), Cd (0.01), Co (0.01), Cu (1.51 ), Fe (7.33), Li (1.08), Mn (0.12), Mo (0.01), Na (697), Ni (0.11), Pb (0.04), Sr (1.45), V (0.01), and Zn (4.69). The mean concentrations of Cr, K, and Mg (0.14, 1,904, and 243 mg/kg wet wt, respectively) were higher in muscle than in liver (0.05, 1,333 and 236 mg/kg wet wt, respectively). The mean concentrations of Cd and Pb (0.01 and 0.04 mg/kg wet wt) in muscle did not exceed the maximum limits established by a European Commission regulation (0.1 mg of Cd/kg and 0.3 mg of Pb/kg, respectively). Considering a mean daily consumption of fish muscle for the adult population of 31.9 g/day published in the report on food consumption by the Spanish Ministry of Agriculture and Fisheries, Food and Environment, Mg made the highest contributions to the intake (2.58% for adult women of 60 kg and 2.22% for men of 70 kg), and the estimated intakes of Al (0.35 to 0.46 mg/day), Cd (0.55 to 0.74 mg/day) and Pb (1.66 to 5.53 mg/day) were below the respective established tolerable intakes. In conclusion, the results of this study show that the consumption of muscle from this benthopelagic species can be considered safe in terms of maximum legal limits, while consumption of liver is discouraged as a major source of exposure to toxic metals, such as Al, Cd, and Pb.

The onset of fretting at the head-stem connection in hip arthroplasty is affected by head material and trunnion design under simulated corrosion conditions.

Mechanically assisted crevice corrosion (MACC) is a mechanism for trunnion damage in total hip arthroplasties (THAs). Retrieval studies have shown reduced MACC-related damage for ceramic heads compared with cobalt-chromium (CoCr) heads. We propose that ceramic heads demonstrate fretting at higher cyclic compressive loads than CoCr heads on titanium alloy trunnions in a simulated corrosion model. A closed electrochemical chamber was used to measure fretting current onset loads for two modern titanium alloy trunnions (Zimmer 12/14 and Stryker V-40) in which trunnion failure has been reported. Ceramic and CoCr alloy 36 + 0 mm heads were impacted on each trunnion and cyclically loaded at 3 Hz with increasing magnitude from 100 to 3,400 N for 540 cycles. Onset load was the cyclic compressive load at which the slope of the average fretting current increased significantly. A CoCr head with V40 trunnion demonstrated the lowest onset load (1,400 N), while the V40 trunnion with a ceramic head showed the highest onset load (2,200 N). Significant differences occurred in average fretting current between head materials for V40 trunnions (p < 0.001) at loads over 2,000 N. CoCr-12/14 and ceramic-12/14 couples demonstrated similar onset loads (2,000 N). All head-trunnion combinations showed cyclical fretting response to loading at 100 N. Head material composition was observed to increase fretting at the taper junction but the effect was taper geometry dependent. Using ceramic heads may reduce the phenomena of trunnion fretting and corrosion but the effect of both trunnion geometry and metallurgy warrants further investigation. Statement of clinical significance: Trunnion corrosion may occur with titanium alloy stems regardless of the head material used. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Phthalocyanine as a redox-active platform for organometallic chemistry.

A systematic approach to the synthesis of σ-organometallophthalocyanines is described. Structurally characterized σ-organoPcM complexes are presented, including the first PcCr-aryl, PcCr-alkynyl, and PcCr-Wittig complexes - representing the first examples of these classes of complexes for any metallophthalocyanine - and the first PcCr-alkyl complexes, which span three chromium and two Pc-ring oxidation states. This represents a rational marriage of the broad organometallic and phthalocyanine fields, opening the door for the exploration of this classical, stable, redox-active macrocycle as an ancillary ligand in metal-carbon chemistry.

DPF soot as an adsorbent for Cu(II), Cd(II), and Cr(VI) compared with commercial activated carbon.

The use of carbon soot recovered from diesel particulate filters (DPF) has been investigated as a potential adsorbent for heavy metals including cadmium, chromium, and copper from wastewater. Results were compared with the adsorption performance of powder activated carbon (PAC). The uptake capacity of heavy metals for soot was found to be higher than PAC. And the thermodynamic study result for both soot and PAC indicated the adsorption procedures are exothermic. The adsorption studies were carried out for both single and binary systems. The data are best modeled by the monolayer model and Langmuir isotherm model for single systems. The adsorption mechanisms are more complex for binary systems. The kinetic studies indicated the adsorption happens rapidly within the first 1 h, and the results can be best modeled by pseudo-second-order model. The SEM-EDS analysis revealed the soot possesses higher porosity and surface area. Carboxylic and hydroxyl functional groups are the predominant surface functional group on both soot and PAC as revealed by FTIR and IEP values. The adsorption can be explained by both Van Der Waals force and electrostatic force. Graphical abstract ᅟ.

Early vascular responses to everolimus-eluting cobalt-chromium stent in the culprit lesions of st-elevation myocardial infarction: results from a multicenter prospective optical coherence tomography study (MECHANISM-AMI 2-week follow-up study).

The use of cobalt-chromium everolimus-eluting stents (CoCr-EES) for ST-segment elevation myocardial infarction (STEMI) reduces the incidence of stent thrombosis compared with bare metal stents, and a substantial difference is apparent in the initial 2 weeks. However, vascular behavior during this early period remains unclear. This was a prospective study (MECHANISM-AMI-2W) to investigate early vascular responses in STEMI patients immediately after CoCr-EES implantation and at 2-week follow-up using frequency domain-optical coherence tomography (FD-OCT). The study enrolled 52 patients (age 63.7 ± 11.7 years, male 85.0%), of whom 44 patients were available for complete serial FD-OCT analyses. Both % uncovered struts and % malapposed struts were improved at 2-week follow-up (63 ± 20 vs. 21 ± 14%, p < 0.0001 and 7.3 ± 9.0 vs. 4.7 ± 5.9%, p = 0.005, respectively). Thrombus was decreased, with significant changes in longitudinal length to stent (28.8 ± 27.7 vs. 18.1 ± 20.2%, p = 0.0001) and maximal area (0.93 ± 0.84 vs. 0.65 ± 0.63 mm2, p = 0.034). As a result, the average lumen area was significantly larger at 2 weeks (6.49 ± 1.82 vs. 6.71 ± 1.89 mm2, p = 0.048, respectively). The number of dissection flaps was lower (0.86 ± 1.11 vs. 0.52 ± 0.90%, p = 0.024). In conclusion, this study showed early vascular responses to CoCr-EES for STEMI lesions-including a significant reduction of thrombus-that resulted in lumen enlargement, earlier progression of strut coverage, and improvements in strut apposition and dissection. The combination of these factors may therefore be responsible for the safety of CoCr-EES within the initial 2 weeks.

Preparation and Characterization of Chromium Doped Ni-Cu-Zn Nano Ferrites.

Chromium doped Ni-Cu-Zn nano ferrites with chemical formula Ni0.2Cu0.2Zn0.6Fe2-xCrxO4 (x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) were prepared by using sol-gel auto combustion method. The prepared precursors of Chromium substituted Ni-Cu-Zn ferrites were sintered at 500 °C for 4h. Compositional stoichiometry were confirmed from EDAX patterns. The XRD data revealed that the all samples possess a single phase cubic spinel structure. The Lattice constant, X-ray density, hopping lengths and crystallite size determined from XRD data decreases with increase in Cr3+ concentration. The IR spectra show two major absorption bands, high frequency band ν1 ≈ 600 cm-1 and low frequency band ν2 ≈ 450 cm-1 attributed to the stretching vibration of tetrahedral and octahedral sites respectively. The surface morphology of the prepared samples was studied by Scanning Electron Microscopy and Transmission Electron Morphology.