Rb Concentrations Research Articles

Comparison of the major- and trace-element compositions of the Kang-dian and Rössing-Husaib uraniferous leucocratic rocks

The Rössing-Husaib area is well-known for its low-grade and large-reserve U deposits hosted by leucogranites. The leucocratic dykes in the Kang-dian area of China resemble the Rössing-Husaib uraniferous leucogranites in occurrences and mineral assemblages, however, it remains disputable if the Rössing-Husaib and Kang-dian leucocratic rocks have consistent U-mineralizing processes. A comparison of the major and trace element data of the leucocratic rocks from both areas may help to better understand the ore-forming mechanisms and provide implications for exploration in the Kang-dian area. The positive correlation between Rb and P2O5 contents for the Rössing leucogranite samples is typical of S-type granitoids in spite of the low A/CNK ratios (∼1.0). The Rössing-Husaib uraniferous leucogranites are generally rich in K2O and Rb, and have high Rb/Sr and Rb/Ba ratios. In contrast, the Kang-dian leucocratic dykes have lower K2O and Rb contents, and lower Rb/Sr and Rb/Ba ratios, suggesting a clay-poor source. The U contents of the Rössing-Husaib and Kang-dian dyke samples are positively correlated with TiO2 contents, but show no correlation with Rb/Sr ratios, which is inconsistent with fractional crystallization. Low-degree partial melting of a U-rich protolith may account for primary U enrichment in the leucocratic rocks. The variable major- and trace-element compositions of the Kang-dian dyke samples may reflect wall-rock assimilation and/or alteration to varying degrees, which further enhanced U enrichment. Relatively low Th/U ratios (∼0.1) favored the final crystallization of uraninite. The uraniferous leucogranites in the Kang-dian and Rössing-Husaib areas are commonly undeformed and emplaced along regional large faults and/or domes at the late stage of orogeny. We propose that decompression and uplift of basement rocks facilitated the generation of uraniferous melts, and regional large faults provided a pathway for the ascent of leucocratic magma from depth.

Лінійний регресійний аналіз впливу біоелементів на частоту гострих респіраторних інфекцій у дітей дошкільного віку

Purpose - to identify the bioelements having the most significant impact on the susceptibility of preschool children to frequent episodes of acute respiratory infections (ARI). Materials and methods. A total of 30 children (14 boys and 16 girls) aged 1-6 years, undergoing inpatient treatment on ARI, were involved in the clinical study. Two integral indicators of acute respiratory infections recurrence, i.e. the infection index and the resistance index, were taken into account for each patient. The children were tested by X-ray fluorescence analysis of 17 bioelements in their hair - Zn, Fe, Cu, Se, Mn, Cr, Co, Br, Ni, Rb, Sr, Sn, Pb, Ca, K, S, and Cl. The statistical processing of the obtained digital material was performed with IBM SPSS Statistics 28 licensed software. A linear regression analysis with stepwise involvement of predictors was applied. Results. In preschool children, there is a moderate negative correlation between hair Rb content and the calculated resistance index (ρ=-0.405; p=0.026; 95% CI: (-0.674)-(-0.042)), according to which lower concentrations of this bioelement are associated with more frequent episodes of ARI. Additionally, Rb has a statistically significant pairwise relationship with several other bioelements studied and the ratios between them. Rb was demonstrated to be directly and most closely correlated with K (ρ=0.842; p<0.001; 95% CI: 0.678-0.926). A prognostic model of the resistance index was obtained, using the linear regression analysis of independent factors. The formula of the prognostic model included only one of the factors studied - the ratio of Mn/Cr content in hair. The informativeness of the mentioned model was 24.9%, which is a quite significant value, taking into consideration a broad range of known predictors for recurrent respiratory infections. Conclusions. The findings are complementary to the available scientific data on the participation of the bioelements in providing resistance to frequent ARI in preschool children. It is planned to continue examining the status of particular bioelements in combination with other potential predictors of recurrent respiratory infections. The study was conducted in accordance with the principles of the Declaration of Helsinki. The study protocol was approved by the local ethics committees of the institutions mentioned in the paper. An informed parental consent was obtained for the study in children. No conflict of interests was declared by the authors.

Human corneal epithelial cell and fibroblast migration and growth factor secretion after rose bengal photodynamic therapy (RB-PDT) and the effect of conditioned medium.

To investigate human corneal epithelial cell and fibroblast migration and growth factor secretion after rose bengal photodynamic therapy (RB-PDT) and the effect of conditioned medium (CM). A human corneal epithelial cell line (HCE-T), human corneal fibroblasts (HCF) and keratoconus fibroblasts (KC-HCF) have been used. Twenty-four hours after RB-PDT (0.001% RB concentration, 565 nm wavelength illumination, 0.17 J/cm2 fluence) cell migration rate using scratch assay and growth factor concentrations in the cell culture supernatant using ELISA have been determined. In addition, the effect of CM has been observed. RB-PDT significantly reduced migration rate in all cell types, compared to controls (p≤0.02). Migration rate of HCE-T cultures without RB-PDT (untreated) was significantly higher using HCF CM after RB-PDT, than using HCF CM without RB-PDT (p<0.01). Similarly, untreated HCF displayed a significantly increased migration rate with HCE-T CM after RB-PDT, compared to HCE-T CM without treatment (p<0.01). Furthermore, illumination alone and RB-PDT significantly decreased keratinocyte growth factor (KGF) concentration in HCF and KC-HCF supernatant, and RB-PDT significantly decreased soluble N-Cadherin (SN-Cad) concentration in HCF supernatant, compared to controls (p<0.01 for all). In HCE-T CM, RB-PDT increased hepatocyte growth factor (HGF) and basic fibroblast growth factor (FGFb) concentration (p≤0.02), while decreasing transforming growth factor β (TGF-β) concentration (p<0.01). FGFb concentration increased (p<0.0001) and TGF-β concentration decreased (p<0.0001) in HCF CM, by RB-PDT. Epidermal growth factor (EGF), HGF, and TGF-β concentration decreased (p≤0.03) and FGFb concentration increased (p<0.01) in KC-HCF CM, using RB-PDT. HCE-T, HCF and KC-HCF migration rate is reduced 24 hours after RB-PDT. In contrast, HCE-T migration is enhanced using HCF CM after RB-PDT, and HCF migration rate is increased through HCE-T CM following RB-PDT. Modulation of EGF, KGF, HGF, FGFb, TGF-β and N-Cadherin secretion through RB-PDT may play an important role in corneal wound healing.

Characterization of Zr-bearing crystalline phases from Rb-bearing model matrix materials

As part of the synthesis of new matrix materials for vitrifcation of highly active radioactive wastes, the crystalline phases formed during rapid cooling from melts of the Na2O–Rb2O–SrO(Ba)–B2O3– SiO2–Al2O3–ZrO2 system with a high Rb and Zr content (up to 10 mol. %) are found and studied. The presence of numerous Zr and Rb-bearing crystals in samples is established by electron microscopy, X-ray diffraction and Raman spectroscopy; their morphology, chemical composition and spectral characteristics are studied. It is concluded that these crystalline phases form due to the excessive content of individual components of the melt and their formation is responsible for the undesirable fnal local heterogeneity and crystallization of matrix materials.

Associations between plasma metal/metalloid mixtures and the risk of central obesity: A prospective cohort study of Chinese adults

Central obesity has increased rapidly over the past decade and posed a substantial disease burden worldwide. Exposure to metals/metalloids has been acknowledged to be involved in the development of central obesity through regulation of cortisol, insulin resistance, and glucocorticoid receptor reduction. Despite the importance, it is lack of prospective study which comprehensively evaluate the relations between multiple metals exposure and central obesity. We explored the prospective associations of plasma metal concentrations with central obesity in a prospective study of the Dongfeng-Tongji cohort. The present study included 2127 participants with a 6.87-year mean follow-up duration. We measured 23 plasma metal/metalloid concentrations at baseline. The associations between metals and incident central obesity were examined utilizing the Cox proportional hazard regression in single and multiple metals models. Additionally, we applied elastic net (ENET), Bayesian kernel machine regression (BKMR), plasma metal score (PMS), and quantile-based g-computation (Qgcomp) models to explore the joint associations of metal mixtures with central obesity. After adjusting potential confounders, we found significant associations of plasma manganese (Mn) and thallium (Tl) concentrations with a higher risk of central obesity, whereas plasma rubidium (Rb) concentration was associated with a lower risk of central obesity both in single and multiple metals models (all FDR <0.05). The ENET and Qqcomp models verified similar metals (Mn, Rb, and Tl) as important predictors for central obesity. The results of both BKMR model and PMS suggested cumulative exposure to metal mixtures was associated with a higher risk of central obesity. Our findings suggested that co-exposure to metals was associated with a higher risk of central obesity. This study expands our knowledge that the management of metals/metalloids exposure may be beneficial for the prevention of new-onset central obesity, which may subsequently alleviate the disease burden of late-life health outcomes.

Multimodal analytical tools for the molecular and elemental characterisation of lesions in brain tissue of multiple sclerosis patients

Multiple sclerosis (MS) is a prevalent immune-mediated inflammatory disease of the central nervous system inducing a widespread degradation of myelin and resulting in neurological deficits. Recent advances in molecular and atomic imaging provide the means to probe the microenvironment in affected brain tissues at an unprecedented level of detail and may provide new insights. This study showcases state-of-the-art spectroscopic and mass spectrometric techniques to compare distributions of molecular and atomic entities in MS lesions and surrounding brain tissues.MS brains underwent post-mortem magnetic resonance imaging (MRI) to locate and subsequently dissect MS lesions and surrounding white matter. Digests of lesions and unaffected white matter were analysed via ICP-MS/MS revealing significant differences in concentrations of Li, Mg, P, K, Mn, V, Rb, Ag, Gd and Bi. Micro x-ray fluorescence spectroscopy (μXRF) and laser ablation – inductively coupled plasma – time of flight – mass spectrometry (LA-ICP-ToF-MS) were used as micro-analytical imaging techniques to study distributions of both endogenous and xenobiotic elements. The essential trace elements Fe, Cu and Zn were subsequently calibrated using in-house manufactured gelatine standards. Lipid distributions were studied using IR-micro spectroscopy and matrix assisted laser desorption/ionisation mass spectrometry imaging (MALDI-MSI). MALDI-MSI was complemented with high-resolution tandem mass spectrometry and trapped ion mobility spectroscopy for the annotation of specified phospho- and sphingolipids, revealing specific lipid species decreased in MS lesions compared to surrounding white matter.This explorative study demonstrated that modern molecular and atomic mapping techniques provide high-resolution imaging for relevant bio-indicative entities which may complement our current understanding of the underlying pathophysiological processes.

Search for the Substantiation of Reasonable Native Elemental Background Values and Reference Variables in Topsoil on Glaciogenic and Postglacial Deposits in a Vilnius Peri-Urban Area

Geochemical indices used to identify the emerging anomalies of potentially harmful elements in topsoil depend on background values (BVs). For urban sites, it is reasonable to estimate native BVs through the targeted selection of peri-urban sampling sites or by distinguishing a useful background subset (BS) within the peri-urban dataset. Here, the goals were to examine the influence of Quaternary deposits on various types of topsoil variables, identify the variables most helpful for cluster analysis intended for the choice of background subset (BS), and compare background values (BVs) based on different background subsets. Composite topsoil samples from a peri-urban area were used for the determination of the following variables: contents of 26 elements and components of the bulk mineralogical composition, as well as the sand, silt, and clay fractions and loss-on-ignition (LOI) at 550 °C and at 950 °C. Although Quaternary lithology influences topsoil elemental contents or granulometric fractions, percentages of illite, kaolinite, orthoclase, quartz, albite, dolomite, and LOI at 550 °C, the choice of BS, according to it, is not recommended, as BVs based on topsoil texture are superior. However, cluster analysis using topsoil fractions &lt; 2, &lt;63, and &gt;63 μm or the contents of Al, Fe, K, Ti, Ga, Nb, Rb, and Si are preferable. It is recommended to use these reference variables for the selection of BS.

Türkiye'deki Ocaklardan Alınan Doğal Kil Mineral Örneklerinde Ağır Metal Konsantrasyonlarının Belirlenmesi

Environmental pollution of heavy metals is increasingly becoming a problem and has become of great concern due to the adverse effects it is causing around the world. Today, various chemical, biological, and physical pollutants arising as a result of rapidpopulation growth, industrialization, and excessive mining activities have become a major problem that adversely affects people, animals, plants, organisms, and ecosystems all over the world. Sepiolite is a clay mineral containing hydrated magnesium silicate and widely used in construction, agriculture, food, fertilizer, pharmaceutical, detergent, cosmetics, paint, paper, etc. The average concentrations of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Rb, Sr, Zr, Cd, Sn, Ba and Pb analyzed in sepiolite samples collected from three quarries (Polatlı, Beylikova, and Sivrihisar) located in the Central Anatolian Region of Turkey using EDXRF spectroscopy were found as 5456.5, 361.0, 42.0, 15.5, 65.2, 3831.5, 8.6, 23.7, 7.8, 11.8, 5.3, 13.7, 1183.2, 25.3, 3.7, 7.2, 131.9 and 5.3 mg/kg, respectively. The average enrichment factor values of V, Cr, Co, Ni, Cu, Zn, As, Sr, Cd, Sn, Ba, and Pb indicated minimal to extremely high enrichment in sepiolite. The values of non-carcinogenic risk index and cancer risk estimated to evaluate potentially health risks caused by PTEs in sepiolite samples were within the acceptable limit and the safe range except for the Beylikova quarry.

Origin of the Early Cretaceous Be mineralization in the Tongbai-Dabie orogen, central China

The Niangniangding Be deposit is a Be-only deposit in the Tongbai-Dabie orogen. The Be mineralization is hosted in albitized granite in the contact zone between biotite monzogranite and metasedimentary rocks. Genthelvite, a Zn-rich helvine-group mineral, is the major carrier of Be. The Niangniangding biotite monzogranite and albitized granite were emplaced at 769–766 Ma and were derived from reworking of Paleoproterozoic crust in a Neoproterozoic continental-rift setting. Hydrothermal monazite coexisting with genthelvite yields an in situ U-Pb age of 126.7 ± 1.6 Ma, demonstrating that the Be mineralization is genetically unrelated with the Niangniangding granite that was albitized by Early Cretaceous ore-forming fluids. The albitization caused an increase of Al, Na, Mn, Fe, Zn, Be and Sr contents and a decrease of Si, K, Rb and Ba contents, reflecting in the formation of spessartite, albite, genthelvite and calcite and the consumption of quartz, K-feldspar and biotite. Petrographic and geochemical evidences hint that ore-forming fluids and metals (e.g., Be, Zn, Mn) may be sourced from non-exposed Cretaceous intrusions and metasedimentary wall rocks (the Huangmailing Formation). The Early Cretaceous intrusions are related to crustal extension due to the rollback of Paleo-Pacific plate. The close spatial relation between genthelvite, calcite, and albitization indicate that the fluid composition (the availability of Na+ and CO2– 3) may have crucially controlled the precipitation of Be. Our study indicates that the Tongbai-Dabie orogen has potential for Early Cretaceous extension-related Be deposits.

Elemental concentrations of seven types of green vegetables grown on small-scale farmlands in rural areas of Japan: Differences according to the type and place of production

We collected seven types of green vegetables produced in 11 areas of Japan and analyzed their elemental concentrations. Halogen analyses were performed with and without prior chemical treatment. The most popular type of spinach exhibited the highest concentrations of Mg, K, and Zn, and the lowest concentrations of alkaline earths (Ca and Sr) and halogens (Cl and Br). Japanese mustard spinach, the second most consumed type of spinach in Japan, exhibited the highest concentrations of P, S, Ca, Fe, and Br and adequate amounts of other essential elements. The other five green vegetables had unique elemental concentrations. In particular, radish had the highest concentrations of Ca, Na, and Cl and the lowest concentrations of Mg, P, Cu, and Zn. Leaves and stalks were separately analyzed. Fe, Cu, Zn, and Mn concentrations tended to be higher in leaves, and K, Na, and Rb concentrations were higher in stalks. Halogen (Cl and Br) concentrations in Japanese mustard spinach produced on farmland near the coast were remarkably high, suggesting an effect of sea salt. However, even in green vegetables produced near the coast, halogen uptake clearly differed by production area. The concentrations of Cl and Br in Japanese mustard spinach produced in two coastal areas were very high and were not removed by washing, but were mostly lost after boiling samples from Taneichi for 3[Formula: see text]min. In contrast, there was no difference in Na concentrations among vegetables produced in coastal and inland areas. The concentrations of essential elements such as Mg, Ca, and Fe were clearly higher in green vegetables from small- versus large-scale production areas, perhaps attributable to differences in the farming methods employed.

Petrogenesis of Miocene high Ba–Sr granitoids from the Central Pamir: Implications for continental growth

High Ba–Sr granitoids differ from the I-, S- and A-type granitoids, and their petrogenesis and role in the evolution of the continental crust remain enigmatic. This paper reports a study of whole-rock geochemistry, and Sr–Nd isotopes, zircon U–Pb geochronology, and Lu–Hf isotopes of the Zankan high Ba–Sr intrusion in the Central Pamir. U–Pb dating of zircons suggests that the pluton was emplaced during the Miocene (10.2 ± 0.1 Ma). The Zankan rocks have high contents of K2O (3.83 to 12.3 wt%), Rb (212–483 ppm), Ba (701–6910 ppm), and Sr (503–3371 ppm). They have several geochemical characteristics that are consistent with A-type granitoids, such as high Na2O + K2O (8.10–14.2 wt%) and Zr + Nb + Ce + Y (336–1393 ppm) contents. All samples have enriched Sr–Nd–Hf isotope compositions, with 87Sr/86Sri = 0.7097 to 0.7126, εNd(T) = −9.3 to −8.4, and εHf(T) = −12.2 to −4.0. Their isotopic compositions differ from those of mafic lower crust in the Central Pamir. Alternatively, the Zankan rocks may have been derived from an enriched lithospheric mantle. Combining our new isotopic results with data from the literature, we propose that a shift from isotopically juvenile to more isotopically evolved compositions in mantle-derived magmas took place from the Eocene to Miocene. The isotopic shift reveals that South Pamir lower crust was underthrusted beneath the Central Pamir lithosphere during the Miocene. Although high Ba–Sr granitoids generally exhibit “crust-like” isotopic characteristics, our data indicate that they play a role in continental growth.

Analysis of Heavy Metals and Other Elements in Soil Samples for its Physicochemical Parameters Using Energy Dispersive X-Ray Fluorescence (EDXRF) Techniques

The present study was conducted to determine the physicochemical properties and the composition of trace elements of soil samples in agriculture lands. This study has been designed to analyze heavy metal contaminations in 12 soil samples collected at a depth 0-20 cm from the agriculture areas of Munshiganj using Energy Dispersive X-Ray Fluorescence (EDXRF) spectroscopy. This study revealed that the maximum Ca, Ti, Mn, Fe, Cu, Zn, Rb, Sr, and Pb contents in soil samples were 76293, 3911, 534, 44652, 57.50, 532, 101.45, 242.11 and 39.31 mg/ kg respectively. A physicochemical study of soil is based on various parameters like soil PH, electrical conductivity (EC), TDS mg/L, Salinity. The value of soil PH found to be 7.53 to 9.24, conductivity was ranging from 22.4-66.5 μs, Total Dissolved Solid (TDS) was ranging from 13.39-37.70mg/L and salinity was ranging 22.40-66.50 μs. Along with the experimental data, several environmental indices (Contamination factor, geo-accumulation index, enrichment factor, pollution load index, Quantification of Anthropogenic Concentration of Metal (QoC) have been identified for comprehensive assessment of our study site, which suggesting that these heavy metals Ca, Ti, Mn, Fe, Cu, Zn, Rb, Sr, and Pb might come in the samples due to anthropogenic activities.

Effects of rubidium substitution of Cs2−xRbxAgBiBr6 double halide perovskites on resistive switching characteristics for memory applications

Cation substitution technique in halide perovskites (HPs) is one of the famous schemes to enhance the characteristics of HPs-based electronic and optoelectronic devices. Here, we fabricated rubidium (Rb) substituted inorganic double halide perovskites (HPs) Cs2−xRbxAgBiBr6 (x = 0, 0.05, 0.1, 0.2, and 0.3) film-based resistive switching (RS) devices and investigated effects of Rb cation substitution on characteristics of RS devices. Grain sizes of the formed Cs2−xRbxAgBiBr6 films gradually increased as increase of Rb contents in the precursor. All of the fabricated RS devices demonstrated non-volatile bipolar RS behavior, device with the Rb content x = 0.1 showed a particularly high on/off ratio (9.29 × 102) of about 30 times greater than pristine Cs2AgBiBr6-based ones (3.09 × 10). In addition, it has been shown that an appropriate amount of Rb substitution at the level of x = 0.1 can effectively prevent the appearance of other crystalline phases at high humidity condition of > 80 %. Through various analytical techniques including SEM, XPS, and SCLC measurement, it was confirmed that an enlargement in grain size resulting in a decrease in defects such as Br vacancies in the fabricated film can lead to an increase in resistance at a high resistance state (HRS) and high on/off resistance ratio. This study provides a facile and feasible way to enhance performances of HPs-based RS devices for practical electronic memory applications.

Short-Term Effect of Rose Bengal Photodynamic Therapy (RB-PDT) on Collagen I, Collagen V, NF-κB, LOX, TGF-β and IL-6 Expression of Human Corneal Fibroblasts, In Vitro

Purpose To investigate collagen I, collagen V, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), lysyl oxidase (LOX), transforming growth factor β1 (TGF-β1) and interleukin-6 (IL-6) expression in healthy and keratoconus human corneal fibroblasts (HCFs and KC-HCFs), 24 h after Rose Bengal photodynamic therapy (RB-PDT). Methods HCFs were isolated from healthy human corneal donors (n = 5) and KC-HCFs from elective penetrating keratoplasties (n = 5). Both cell cultures underwent RB-PDT (0.001% RB concentration, 0.17 J/cm2 fluence) and 24 h later collagen I, collagen V, NF-κB, LOX, TGF-β1 and IL-6 mRNA and protein expression have been determined using qPCR and Western blot, IL-6 concentration in the cell culture supernatant by ELISA. Results TGF-β1 mRNA expression was significantly lower (p = 0.02) and IL-6 mRNA expression was significantly higher in RB-PDT treated HCFs (p = 0.01), than in HCF controls. COL1A1, COL5A1 and TGF-β1 mRNA expression was significantly lower (p = 0.04; p = 0.02 and p = 0.003) and IL-6 mRNA expression was significantly higher (p = 0.02) in treated KC-HCFs, than in KC-HCF controls. TGF-β1 protein expression in treated HCFs was significantly higher than in HCF controls (p = 0.04). IL-6 protein concentration in the HCF and KC-HCF culture supernatant after RB-PDT was significantly higher than in controls (p = 0.02; p = 0.01). No other analyzed mRNA and protein expression differed significantly between the RB-PDT treated and untreated groups. Conclusions Our study demonstrates that RB-PDT reduces collagen I, collagen V and TGF-β1 mRNA expression, while increasing IL-6 mRNA and protein expression in KC-HCFs. In HCFs, RB-PDT increases TGF-β1 and IL-6 protein level after 24 h.

Amphibole peridotite and hornblendite of the Schrisheimite Hill intrusion of the Revdinskiy massif (Ural Platinum Belt)

Research subject. We studied the concentric-zonal massif (≈400 × 400 m) of amphibole-rich ultramafic rocks composed of amphibole peridotite (schriesheimite and amphibole wehrlite) with olivinite schlieren, pyroxenite and hornblendite located among gabbro at the Schrisheimite Hill in the Revdinskiy massif of the Ural Platinum Belt. The scope is characteristic of both of amphibole peridotites, which are extremely rare in the massifs of the Ural Platinum Belt, and the associated amphibole-rich ultramafic rocks. Aim. To expand the understanding of aqueous ultramafic magmatism in Ural Platinum Belt massifs. Materials and methods. To determine the age, we selected monofractions of high-alumina amphibole (pargasite-magnesiohastingsite) from two samples. Amphibole is not significantly altered by the regional metamorphism. 40Ar/39Ar dating was carried out according to the method described in (Travin et al., 2009; Yudin et al., 2021). The argon isotope composition was measured using a Micromass 5400 mass spectrometer (IGM SB RAS). Results. Amphibole peridotite has a hypidiomorphic (subhedral) or poikilitic texture. It is typical of igneous rocks, which indicates the crystallization of amphibole peridotite was by H2O-saturated magmas. Schlieren segregations of fine-grained schriesheimites and fine-grained olivinites are among coarse-grained schriesheimites. Amphibole peridotite, pyroxenite and hornblendite are deficient in high field strength elements (HFSE) and enriched in large ion lithophile elements (LILE) (with contrast concentration of Cs and Rb), which is typical of supra-subduction igneous formations. We obtained a 40Ar/39Ar age of 437.2 ± 6.7 Ma for an amphibole from hornblendite, which differs significantly from the ages of hornblendite determined earlier. Conclusions. Our new data indicate that hornblendite dikes in different UPB massifs formed over a fairly long time interval from the Early Silurian to the Early Devonian. These data expand modern ideas about the timing and nature of ultramafic water magmatism in the massifs of the Ural Platinum Belt.

Early and long-distance uptake by Eucalyptus grandis of N, K and Ca tracers injected down to a depth of 7 m

Eucalyptus plantations are commonly fertilized at planting to sustain high biomass production over successive rotations in nutrient-poor soils. However, the dynamics of nutrient uptake by tree roots in the early stages of stand development, depending on the lateral distance from the trees and the depth in the soil, are poorly documented. We assessed the potential uptake of N, K and Ca, from 6 to 18 months after planting, by Eucalyptus grandis trees depending on: i) the lateral distance from the tracer injection point and ii) the depth in the soil. At 6 months after planting, we injected 15NO3–, Rb+, Sr2+ and Cs+ tracers at depths of 1, 3, 5, and 7 m, respectively. Recently expanded leaves were then sampled monthly on 16 target E. grandis trees located at lateral distances ranging from 0.75 to 11.1 m from the injection points, and on 4 more distant E. grandis control trees; 15N contents (atom %) and concentrations of Rb, Cs and Sr in the leaves were determined at each sampling date, and compared to those of control trees to detect the dates of tracer uptake for each individual. A LOESS model was applied to account for the temporal trend and inter-tree variability among the control trees. Tracer uptake by a target tree was detected if the measurements exceeded the upper limit of the prediction interval (α = 0.005) generated by the model. Only the 6 target trees located within 2.0 m from the injection point took up the 15NO3– tracer. However, Rb+, Sr2+ and Cs+ tracers were taken up to lateral distances of approx. 11 m from the injection point. Tracer uptake occurred as early as 9, 7, 8 and 9 months after planting for 15NO3–, Rb+, Sr2+ and Cs+, respectively. Four trees located within 2.8 m from the injection point took up the 3 cation tracers, injected between the depths of 3 m and 7 m. All but one of the target trees took up at least one cation tracer. The potential of Eucalyptus trees to take up nutrients early, at long distance and at depth, can be promoted by silvicultural practices enhancing rapid root development after planting, as subsoiling in commercial plantations and large planting holes in smallholder plantations. Our results also suggest that fertilization could be applied only once at planting in Eucalyptus stands established on deep tropical soils, with low risks of nutrient losses by deep drainage.

Petrographic and geochemical properties of the ignimbrites around Hatunsaray (Konya)

The study area is located around the town of Hatunsaray, approximately 40 km away from the south-west of Konya. In this study, the petrological and geochemical characteristics of the Bulumya ignimbrite, Detse ignimbrite and Sadıklar ignimbrite observed in the region were revealed. The study area contains Upper Miocene - Lower Pliocene aged Güneydere formation and overlying Bulumya ignimbrite, Detse ignimbrite, Sadıklar ignimbrite and Quaternary alluviums. All these units were formed in the Upper Miocene - Lower Pliocene aged fluvial and lake environment and have a lateral vertical transition with carbonate, clastic units. The gray-colored Bulumya ignimbrite contains andesite-dacite rock fragments and large pumice grains. The Detse Ignimbrite is yellow in color and shows a well sorted lapilli tuff composition. The Sadıklar Ignimbrite, on the other hand, contains agglomeratic levels with yellow colored slightly fused lenses and wedge geometry. All ignimbrite samples have porphyric texture and were classified as “crystal-vitric tuff” and “crystal lithic-vitric tuff” in the glass-crystal-rock fragment classification. Petrographic investigations of ignimbrites show that major components are quartz, plagioclase, plagioclase microliths, biotite, amphibole, opaque minerals and rock fragments. Geochemical data shows that all ignimbrite samples are subalkaline, trachy-andesite, andesite-basaltic andesite and calc-alkaline in character. When the main oxide, trace and rare earth elements in ignimbrites are evaluated, fractional crystallization controlled by feldspar minerals is observed. In addition, the high K and Rb content in the spider diagrams indicate crustal contamination. The distribution of the ignimbrite samples in the Rb/Y-Nb/Y diagram suggests that the magma source forming the samples is enriched by subduction and/or crustal components.

The Size Induced Phase Transition in the Rb0.95NbxMo2−xO6.475–0.5x (x=1.31–1.663) Solid Solution with β‐Pyrochlore Structure

AbstractThe size induced phase transition for non‐cubic β‐pyrochlore compounds Rb0.95NbxMo2−xO6.475–0.5x (x=1.31–1.663) has been studied in detail. The Rb0.95NbxMo2−xO6.475–0.5x (x=1.31–1.663) powders with different size particles have been prepared and investigated by X‐ray powder diffraction analysis and scanning electron microscopy with X‐ray microanalysis. The Rb0.95Nb1.5Mo0.5O5.73 and Rb0.95Nb1.375Mo0.625O5.79 powders consisted of ~20 μm crystals possess orthorhombic Pnma symmetry, whereas the same powders with particle size less 1 μm have cubic Fd‐3m and characterized by decreasing Rb content – Rb0.7Nb1.5Mo0.5O5.58 and Rb0.9Nb1.625Mo0.375O5.62. The crystal structure of Rb0.7Nb1.5Mo0.5O5.58 cubic phase refinement has been performed using the Rietveld method; and crystallographic reasons of structure reconstruction have been discussed. The electronic structure and band gap of Rb0.95NbxMo2−xO6.475–0.5x (x=1.31–1.663) compounds have been studied. Moreover the comparison of electronic structure for cubic and orthorhombic phases has been performed.

Magmatic-hydrothermal evolution of the aquamarine-bearing Yamrang Pegmatite, Eastern Nepal: Insights from beryl, garnet, and tourmaline mineral chemistry

The Ikhabu Pegmatite Field (IPF) in the Nepal Himalaya is a newly discovered rare-element (REL) pegmatite field that hosts the Yamrang pegmatite, the primary source of the famous Nepalese aquamarines. In this contribution, we provide a comprehensive description of the geology of both the IPF and the Yamrang pegmatite, offering insights into the evolutionary stages of the Yamrang pegmatite based on its internal texture and the mineral chemistry of beryl, garnet, and tourmaline. The Yamrang pegmatite is classified as a beryl-columbite subtype of REL pegmatite, exhibiting axial symmetric zonation and is differentiated into five mineralogical-textural zones during magmatic and hydrothermal stages. The magmatic stage involves undercooling, disequilibrium crystallization, and fractional crystallization whereas the hydrothermal stage comprises alkali-enriched fluid exsolution, the formation of miarolitic cavities, and the crystallization of aquamarine. Yamrang aquamarines are enriched in FeO, up to 1.1 wt%, with Fe2+ as the primary chromophore, resulting in their blue color. Two types of beryl have been identified: magmatic beryl in zones 3 and 4 and hydrothermal beryl in miarolitic cavities (zone 5). Magmatic beryls are characterized by their alkali-poor to sodic composition, prismatic to columnar habit, homogeneous texture, and the presence of Fe-Al octahedral substitution. In contrast, hydrothermal beryls belong to the sodic to Li-Cs beryl group, with tabular to acicular habit, weak compositional zoning, and channel-tetrahedral substitution. Yamrang garnet belongs to the almandine-spessartine series, while the tourmalines are Mg-Ca rich dravite-schorl to Fe-Mn rich schorl variety. Alkali-poor to Li-Cs beryl with low REE contents, spessartine garnet (spessartine component, Xsps ∼ 52) with high HREE, and schorl with high Ti but low Li, Pb, and REE contents suggests that the Yamrang Pegmatite is an intermediate-fractionated REL pegmatite. Potential pegmatite evolution indicators for IPF include high alkali, Fe, Mn, and Rb contents in beryl, high Xsps in garnet, and an increase in Li, Fe, Mn, Zn, Ga, and Nb, alongside depletion of Mg, Ca, Ti, and Ta in schorl. The identification of a rare metal pegmatite field in the Nepalese Himalaya reinforces the general rare metal mineralization potential of the entire Himalaya region.

Analysis of serum trace elemental content in pre-post chemotherapy breast cancer patients using synchrotron radiation based X-ray fluorescence

Synchrotron Radiation induced X-ray Fluorescence (SRXRF), accelerator based analytical technique, was used to analyze the trace elemental content in the serum of pre-post chemotherapy undergoing breast cancer patients (BCPs) and healthy controls (HCs). SRXRF measurements were carried out on beamline-16 (Microprobe X-fluorescence beamline), Indus synchrotron light source, Raja Ramanna center for Advanced Technology (RRCAT), Indore, India. Validation of SRXRF experimental set-up used in the current work was done by using National Institute of Standards and Technology (NIST) standard reference material bovine liver (1577c) and International Atomic Energy Agency (IAEA) reference material-animal blood (A-13) in the same conditions as that of the studied serum samples. Results show the presence of thirteen trace elements (TEs) K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Br, Rb, and Pb in both the groups of BCPs and HCs. Concentrations of TEs K, Ca, Cr, Fe, Cu, Br, and Pb were noticed to be higher in pre-chemotherapy BCPs when compared with HCs while content of TEs Mn, Co, Ni, Zn, Se, and Rb were decreased in pre-chemotherapy BCPs. Furthermore, it was observed that the elevated levels of some TEs decreased after chemotherapy. Observed changes in levels of TEs in pre-post chemotherapy BCPs may play an essential role in carcinogenesis and these TEs may be useful to prepare trace-metal based drugs to treat the BCPs and to improve their survival rates.