Retention Of Sr Research Articles

Mechanisms Governing 90Sr Removal and Remobilisation in a VLLW Surface Disposal Concept

Flow-through columns were used to assess potential long-term trends in 90Sr biogeochemistry and transport in a Finnish near-surface very low-level waste (VLLW) repository concept. Experiments simulated the effects of water intrusion and flow through the repository barrier and backfill materials, examining impacts on 90Sr migration. Artificial rainwater containing 2.0 mg/L stable Sr (as a proxy for 90Sr) was pumped through column systems that had varying compositions from a matrix of rock flour (backfill material), bentonite (backfill/sealing material), and carbon steel (waste encapsulation material), for 295 days. Effluent geochemistry was monitored throughout. Sr retention behaviour in all column systems was broadly similar. Sr removal from influent rainwater was marked (~95% removed) at the beginning of the experiments, and this degree of removal was maintained for 20 days. Thereafter, Sr concentrations in the effluents began to rise, reaching ~2 mg/L by 295 days. Further, 56%–67% of added Sr was retained in the repository materials over the 295-day reaction period. Analysis of the effluents indicated that colloids did not form; as such, Sr output was likely to be aqueous Sr2+. Upon completion of the experiment, solid-associated Sr distribution and speciation in the columns were assessed through column sectioning and post-mortem analyses, which encompassed the following: total acid digests, sequential extractions, and XAS analysis. The total acid digests and sequential extractions showed that Sr was evenly distributed throughout the columns and that the majority (68%–87%) of solid-associated Sr was in the exchangeable fraction (MgCl2). This suggested that a major part of the solid-phase Sr was weakly bound to the column materials via outer-sphere sorption. Interestingly, a smaller amount of Sr (7%–23%) could only be extracted by aqua regia, suggesting that a proportion of Sr may bind more strongly to the barrier materials. XAS analysis of select samples confirmed that the dominant Sr phase was sorbed to the rock flour and bentonite, but not corroded carbon steel. Columns were also subject to remobilisation experiments using artificial rain- and seawater without added Sr. While rainwater remobilised Sr slowly, high-ionic strength seawater remobilised Sr at much higher rates in the systems containing bentonite. Interestingly, Sr was well retained in the rock flour-only system following rain and seawater intrusion. Overall, the results indicate that the column materials provide reactive surfaces for Sr removal should it be released from waste packages; however, the backfill and barrier materials have limited retention capacity, and the dominant sorption interaction is relatively weak. The safety case for the shallow disposal of radioactive waste should consider the possibility of seawater intrusion and that the bentonite-bound Sr was significantly more susceptible to remobilisation following seawater, despite retaining slightly more Sr during sorption experiments.

A simple assessment of the effect of strontium on the urinary excretion of calcium in Sprague Dawley rats.

This study was aimed at investigating the impact of varying concentrations of strontium (Sr) on calcium (Ca) excretion via the urine and determine its impact on kidney stone formation. Twenty adult male Sprague Dawley rats weighing between 200 and 300g were selected. The rats were randomly divided into four groups of five. One group was used as a control group while the other three groups were experimental. The diet of the rats was modulated over a 12week period to investigate the impact of Sr on the urinary excretion of Ca. Urinary samples were collected every 2weeks from the rats. The rats were fed water ad libitum. After the study the rats were euthanised and their kidneys harvested. Urine and kidney samples from the rats were analysed using Total Reflection X-Ray Fluorescence (TXRF). In the urine excretion of Ca increased with increased intake of Sr in the diet. Sr excretion via the urine also increased with increased dietary intake. There was a correlation of 0.835 at the significance level of 0.01 between Ca and Sr in the urine. However, for the kidneys, the varying concentration of Sr did not impact the retention of Ca in the kidneys. There was increased retention of Sr in the kidneys with increased dietary intake. In this study an increase of Sr in the diet resulted in an increase in urinary excretion of Ca.

Strontium interaction with unblended and Low-pH cementitious wasteforms: pH-dependent leaching experiments and geochemical modelling

Cementitious materials are widely-applied for the solidification and stabilization of low and intermediate level radioactive waste streams, that often contain strontium-90. Low-pH cement pastes, based on ordinary Portland cement (OPC) supplemented with pozzolanic additives, were found to have better Sr retention capabilities than unblended OPC pastes. However, precise definition of the phases and processes that control Sr retention in unblended and low-pH OPC pastes is still lacking. The present study combines experimental work with thermodynamic modelling to investigate the retention of Sr in unblended pastes compared to low-pH pastes. The unblended and low-pH pastes were prepared each in two formulations: one based on reagent grade alite (tri-calcium silicate) and the other based on OPC. The chemical and mineralogical behavior of the paste were studied by pH-dependent leaching test. The pastes characteristics were compared in order to assess the impact of: (1) the addition of amorphous silica to the pastes and (2) the presence of minor OPC phases (which are absent in the alite-based pastes) on Sr binding. The low-pH systems showed one order of magnitude lower Sr leachability than the unblended systems at the natural pH. Moreover, the leaching curves indicated that the low-pH systems bind Sr effectively at pH > 7 while for the unblended systems binding is effective only at pH > 10. These results are attributed to the difference in Sr binding to low Ca/Si C–S–H, dominant in low-pH systems, versus the high Ca/Si C–S–H, dominant in unblended systems. Additionally, it was shown that Sr binds mainly to the C–S–H phase rather than to minor phases. The leaching results were thermodynamically modelled and correlated successfully with the experimental findings. A novel modelling approach is offered for the consideration of partial pozzolanic reaction and SiO2-gel formation. The effect of these processes on strontium retention has been successfully demonstrated.

Sorbent extraction behavior of cesium and strontium from nitric acid solutions using a new high thermal stability material

In this study a new low-cost carbonaceous material was prepared from husks of opuntia-ficus-indica as a starting material (precursor) which was accomplished by chemical activation route using H3PO4 impregnation. The material has been identified by different analytical tools. The sorption performance of Cs(I) and Sr(II) from HNO3 solutions was examined through batch system. Variations of the distribution coefficients (Kd) as a function of HNO3 concentration in the range 0.001–5.0 M were presented. Some of separation probabilities were suggested. The results attained signals that the Sr(II) selectivity is higher than that of Cs(I) at high molarities. The retention capacity (qe) of Cs(I) and Sr(II) ions increased with growing temperature. The capacities at 0.001 M HNO3 are 34 and 108 mg/g for Cs(I) and Sr(II), respectively. Whereas, at 2.0 M HNO3 capacities were about 4 and 37 mg/g for each of Cs(I) and Sr (II), respectively. This studies demonstrates that the prepared carbonaceous sorbent is an economically effective sorbent for retention of Cs(I) and Sr(II) species from HNO3 solutions. Cs(I) and Sr(II) removal potential was tested from simulated low- and intermediate-level radioactive waste samples.

Retention of strontium in high- & low-pH cementitious matrices – OPC vs. model systems

Strontium can be found in low/intermediate level radioactive waste streams, often solidified by Ordinary Portland Cement (OPC) matrices. Amorphous silica is added to improve wasteform performance, leading to low-pH systems. Our aim is to identify the phases controlling strontium immobilization in OPC matrices. The novelty of this work resides in combination between two approaches: 1) Comparing OPC systems to model systems based on alite, yielding matrices containing only major phases, emphasizing the relative role of minor phases; 2) Comparing high- & low-pH pastes. Pastes were characterized using calorimetry, XRD, DTG, SEM/EDS and porosimetry. Leaching experiments were conducted to study Sr retention and diffusivity. Strontium diffusivities in low-pH pastes are lower with respect to high-pH equivalents, despite their higher porosities, due to preferred Sr sorption to low Ca/Si C-S-H. OPC pastes show better Sr retention relative to model systems, suggesting that minor phases (like ettringite and AFm) improve Sr retention.

Insight into the role of the zeolitization process in enhancing the adsorption performance of kaolinite/diatomite geopolymer for effective retention of Sr (II) ions; batch and column studies

Diatomite/kaolinite-based geopolymer (GP) was synthesized and incorporated in zeolitization process (Z/GP) to investigate the role of the zeolite phases in inducing its retention capacity of the dissolved Sr (II) ions in water. The retention of Sr (II) ions using Z/GP in comparison with GP was evaluated based on both batch and fixed-bed column studies. In the batch study, the zeolitized geopolymer (Z/GP) shows enhancement in the Sr (II) retention capacity (193.7 mg/g) as compared to the normal geopolymer (102 mg/g). Moreover, the recyclability studies demonstrate higher stability for Z/GP than GP with a retention percentage higher than 90% for five reusing runs. The kinetic and the equilibrium properties of the occurred Sr (II) retention reactions follow the assumption of the Pseudo-Second order model (R2 > 0.96) and Langmuir model (R2 > 0.97), respectively. The Gaussian energies (15.4 kJ/mol (GP) and 11.47 kJ/mol (Z/GP)) related to retention mechanism of chemical type and within the suggested range for the zeolitic ion exchange processes. The Sr (II) retention reactions by GP and Z/GP are of spontaneous and exothermic properties which qualifies the products to be used at low-temperature conditions (20 °C). The column studies also declared higher performance for the Z/GP fixed bed as compared to the normal GP bed considering the total Sr (II) retention percentage (72.9%), treated volume (8 L), saturation time (1620 min), and a maximum capacity of Z/GP particles in the bed (567.6 mg/g).

THE EFFECT OF PHYTASE ENZYMES ADDITION ON ARTIFICIAL FEED ON HOVEN’S CARP GROWTH, Leptobarbus hoevenii (Bleeker, 1851)

Hoven’s carp is a freshwater fish found in Indonesian. This study aims to study the effect of the addition of phytase enzymes with different doses on commercial feed on the growth rate of hoven’s carp and determine the dose of the phytase enzyme that is best for the growth of sooty fish. This research was conducted for 70 days at the Fisheries Cultivation Laboratory, Department of Fisheries and Marine Resources, Faculty of Agriculture, University of Lampung. This study used a completely randomized design with 4 treatments and 3 replications. Treatment A without the administration of phytase enzymes, B giving phytase enzymes 250 mg/kg of feed, C giving phytase enzymes 500 mg/kg feed, D giving phytase enzymes 750 mg/kg of feed. The parameters observed were absolute length growth, absolute weight growth, daily growth rate, SR, FCR, and protein retention. The results showed that the administration of phytase enzymes had an effect on fish growth with a dose of phytase enzyme 750 mg/kg of feed showing good results.

Identification and characterization of self-association domains on small ankyrin 1 isoforms

In striated muscles, the large scaffolding protein obscurin and a small SR-integral membrane protein sAnk1.5 control the retention of longitudinal SR across the sarcomere. How a complex of these proteins facilitates localization of longitudinal SR has yet to be resolved, but we hypothesize that obscurin interacts with a complex of sAnk1.5 proteins. To begin to address this hypothesis, we demonstrate that sAnk1.5 interacts with itself and identify two domains mediating self-association. Specifically, we show by co-precipitation and FLIM-FRET analysis that sAnk1.5 and another small AnkR isoform (sAnk1.6) interact with themselves and each other. We demonstrate that obscurin interacts with a complex of sAnk1.5 proteins and that this complex formation is enhanced by obscurin-binding. Using FLIM-FRET analysis, we show that obscurin interacts with sAnk1.5 alone and with sAnk1.6 in the presence of sAnk1.5. We find that sAnk1.5 self-association is disrupted by mutagenesis of residues Arg64-Arg69, residues previously associated with obscurin-binding. Molecular modeling of two interacting sAnk1.5 monomers facilitated the identification of Gly31-Val36 as an additional site of interaction, which was subsequently corroborated by co-precipitation and FLIM-FRET analysis. In closing, these results support a model in which sAnk1.5 forms large oligomers that interact with obscurin to facilitate the retention of longitudinal SR throughout skeletal and cardiac myocytes.

Liquid scintillation counter calibration approach for 90Sr detection and testing performance of TK100 resin

90Sr detection efficiency determination was applied for liquid scintillation counting (LSC) by computing a model for the relation between detection efficiency and the time passed since radiochemical separation. This allowed more flexibility in analysis times after separation as the model accounts for 90Y in-growth. Establishment of secular equilibrium was therefore not required for LSC measurements. In addition, this approach increases counting efficiency compared to classical ones as both 90Sr and 90Y spectrums are used. This in turn has a positive impact on minimum detectable activity. The method was validated using proficiency test samples for both Čerenkov radiation measurement and scintillation cocktail measurement. Commonly used extraction material Sr-resin was compared to alternative, TK100 resin. Inductively-coupled plasma mass spectrometry measurements for recovery determination showed limitations for TK100 usage due to incomplete Sr retention on the resin. Limitations were further confirmed by LSC activity measurements.

THE EFFECT OF rGH ADDITION ON ARTIFICIAL FEED ON HOVEN’S CARP GROWTH, Leptobarbus hoevenii (Bleker, 1851)

Hoven’s carp is one of the potential fish in Indonesia to be developed. But due to its slow growth, making people not cultivating it. This research aimed to study the effect of using rGH and determine the best dosage on growth of hoven’s carp. Hoven’s carp used were 70 - 90 mm in size and 5 - 6 g in weight 4 months old. Hoven’s carp used are 10 fish in each pond This study used a completely randomized design with 4 treatments and 3 replications. The treatment was A (without administration of rGH), B (administration of rGH 1 mg/kg of feed), C (administration of rGH 2 mg/kg of feed), and D (administration of rGH 3 mg/kg of feed). Parameters observed consisted of growth absolute length, the growth of absolute weight, SR, FCR, and protein retention. The results showed that the effect on hoven’s carp growth of rGH and best dose in this study is in treatment B (administration of rGH 2 mg/kg of feed)

Biogeochemical Controls on Strontium Fate at the Sediment-Water Interface of Two Groundwater-Fed Wetlands with Contrasting Hydrologic Regimes.

Radioactive strontium (Sr) is a common groundwater contaminant at many nuclear sites. Its natural retention in groundwater-fed wetlands is an attractive remediation strategy. However, at present, the biogeochemical mechanisms controlling Sr transport at the sediment-water interface are poorly understood. In this field study, Sr fate was investigated in two wetlands with contrasting vegetation and hydrologic regimes. The marsh was an open-water wetland with constant water table and no emergent vegetation. The swamp was vegetated with fluctuating water levels and a thick mat of submerged cattail litter in the water column. High-resolution porewater Sr concentrations and solid-phase sediment Sr species revealed distinct profiles between the two wetlands. The marsh exhibited a strongly reduced environment and sharp concentration peaks at the sediment-water interface. In contrast, the smaller concentration gradients of the swamp resulted in a reduced flux of Sr to the surface water. The organic fraction of the sediment dominated Sr retention compared to the inorganic iron and manganese oxides. However, the marsh had a significant fraction of recalcitrant Sr presumably due to its incorporation into sulfur and/or carbonate minerals. These results suggest that vegetated wetlands with fluctuating hydrologic regimes could act as efficient sinks for Sr pollution.

Mineralogical, geochemical and stable isotope studies of kaolin deposits in north-west Gonabad district (eastern Iran)

Kaolin deposits, situated ~10 km north-west of Gonabad (eastern Iran), formed by the intrusion of hydrothermal fluids from a granite dyke in the western part of the study area, and the alteration of rhyolite, dacite and rhyodacite related to Eocene volcanism. There are four major kaolin quarries. The rocks in the investigated area are mainly slate, dacite, rhyolite, andesite-trachyandesite, and lithic and felsic tuffs. The mineralogical compositions of the kaolin deposits are dominated by quartz, kaolinite, dickite and illite with minor chlorite, montmorillonite, albite, hematite, pyrite and gypsum. Sanidine and plagioclase crystals in rhyolite-rhyodacite are sericitized and kaolinized. Whole rock chemistry of the kaolin deposits shows high contents of SiO 2 and Al 2 O 3 . Enrichments of Sr in some samples demonstrate retention of Sr and depletion of Rb, Ba, Ca and K during hydrothermal alteration of sanidine and plagioclase within the volcanic units. The chondrite-normalized rare earth element patterns of the clay deposits show LREE enrichments (La/Lu)cn = 6.75 to 57.74, pointing to kaolinization in low-pH waters. The isotope composition of the kaolin (δ 18 O ~+5‰) is consistent with formation at isotopic equilibrium with water of hydrothermal/magmatic origin. The mineralogical composition, REE contents and elemental ratios in these deposits suggest provenance of the kaolin deposits mainly from felsic rocks and hydrothermal fluids. The O isotopic character also supports these results.

Comparison of structure, morphology, and leach characteristics of multi-phase ceramics produced via melt processing and hot isostatic pressing

Melt processing of multi-phase ceramic waste forms offers potential advantages over traditional solid-state synthesis methods given both the prevalence of melters currently in use and the ability to reduce the possibility of airborne radionuclide contamination. In this work, multi-phase ceramics with a targeted hollandite composition of Ba1.0Cs0.3Cr1.0Al0.3Fe1.0Ti5.7O16 were fabricated by melt processing at 1675 °C and hot isostatic pressing (HIP) at 1250 and 1300 °C. X-ray diffraction analysis (XRD) confirmed hollandite as the major phase in all specimens. Zirconolite/pyrochlore peaks and weaker perovskite reflections were observed after melt processing, while HIP samples displayed prominent perovskite peaks and low-intensity zirconolite reflections. Melt processing produced specimens with large (>50 μm) well-defined hollandite grains, while HIP yielded samples with a more fine-grained morphology. Elemental analysis showed “islands” rich in Cs and Ti across the surface of the 1300 °C HIP sample, suggesting partial melting and partitioning of Cs into multiple phases. Photoemission data revealed multiple Cs 3d spin-orbit pairs for the HIP samples, with the lower binding energy doublets likely corresponding to Cs located in more leachable phases. Among all specimens examined, the melt-processed sample exhibited the lowest fractional release rates for Rb and Cs. However, the retention of Sr and Mo was greater in the HIP specimens.

Quantifying Technetium and Strontium Bioremediation Potential in Flowing Sediment Columns

The high-yield fission products 99Tc and 90Sr are found as problematic radioactive contaminants in groundwater at nuclear sites. Treatment options for radioactively contaminated land include bioreduction approaches, and this paper explores 99mTc and 90Sr behavior and stability under a range of biogeochemical conditions stimulated by electron donor addition methods. Dynamic column experiments with sediment from the Sellafield nuclear facility, completed at site relevant flow conditions, demonstrated that Fe(III)-reducing conditions had developed by 60 days. Sediment reactivity toward 99Tc was then probed using a 99mTc(VII) tracer at <10-10 mol L-1 and γ camera imaging showed full retention of 99mTc in acetate amended systems. Sediment columns were then exposed to selected treatments to examine the effects of different acetate amendment regimes and reoxidation scenarios over 55 days when they were again imaged with 99mTc. Here, partially oxidized sediments with no further electron donor additions remained reactive toward 99mTc under relevant groundwater O2 and NO3- concentrations over 55 days. Immobilization of 99mTc was highest where continuous acetate amendment had resulted in sulfate-reducing conditions. Interestingly, the sulfate reducing system showed enhanced Sr retention when stable Sr2+ was added continuously as a proxy for 90Sr. Overall, sediment reactivity was nondestructively imaged over an extended period to provide new information about dynamic iron and radionuclide biogeochemistry throughout realistic sediment redox cycling regimes.

Determination of Sr-90 in milk samples from the study of statistical results

The determination of 90Sr in milk samples is the main objective of radiation monitoring laboratories because of its environmental importance. In this paper the concentration of activity of 39 milk samples was obtained through radiochemical separation based on selective retention of Sr in a cationic resin (Dowex 50WX8, 50-100 mesh) and subsequent determination by a low-level proportional gas counter. The results were checked by performing the measurement of the Sr concentration by using the flame atomic absorption spectroscopy technique, to finally obtain the mass of 90Sr. From the data obtained a statistical treatment was performed using linear regressions. A reliable estimate of the mass of 90Sr was obtained based on the gravimetric technique, and secondly, the counts per minute of the third measurement in the 90Sr and 90Y equilibrium, without having to perform the analysis. These estimates have been verified with 19 milk samples, obtaining overlapping results. The novelty of the manuscript is the possibility of determining the concentration of 90Sr in milk samples, without the need to perform the third measurement in the equilibrium.

Effect of Tillage and Residue Retention on Soil Properties and Crop Yields in Wheat-Mungbean-Rice Crop Rotation under Subtropical Humid Climate

The effects of conservation agriculture (CA) practices on soil properties along with crop yields of rice-based triple cropping systems have not been adequately assessed in Bangladesh. An experiment was conducted at Bangladesh Agricultural Research Institute, Gazipur, Bangladesh from 2009 to 2012 to assess the effects of tillage practices and crop residue retention on soil physical properties, soil organic carbon (SOC) and crop yields in a wheat-mungbean-rice system. Treatments consisted of three tillage practices (MT: minimum tillage; CT: conventional tillage and DT: deep tillage) and eight levels of crop residue management (S0—no residues retention, Sr—retention of 30 cm rice straw, Sm—whole mungbean stover retention, SW—30 cm wheat straw retention, Smr—whole mungbean stover & 30 cm rice straw retention, Srw—30 cm rice & wheat straw retention, Smw—whole mungbean stover & 30 cm wheat straw retention and Swrm—30 cm wheat and rice straw along with whole mungbean stover retention) were applied in split plot design with three replications. Bulk density (BD) and porosity responded positively to MT and increased residue retention of all crops (p > 0.05). Minimum tillage and Swrm also significantly accumulated SOC (p < 0.05; 0.38% higher than DT with no residue retention) and retained soil moisture (p < 0.05). Minimum tillage practice performed better in upland crops (p < 0.05; wheat & mungbean yields) and CT outperformed MT in wetland rice crop (p < 0.05). The grain and straw yields of wheat and rice were also influenced by previous crop residue retentions (p < 0.05). The results, therefore, suggested that increased residue retention with minimum tillage practices improved soil properties and yield of upland crops but with deeper tillage practices consistently maintained wetland rice production.

Molecular Characterization of SRSF2 Mutation Identifies a Clinically Relevant Lncrna (MALAT1) in Chronic Myelomonocytic Leukemia (CMML)

SRSF2 is mutated at proline 95 (P95) in approximately 45% of patients with CMML. The consequence of SRSF2 P95H mutations on splicing has been associated with change in target RNA motif preference compared to wild type that favors CCNG over GGNG resulting in aberrant splicing abnormalities. Although this has led to several downstream mis-spliced candidates that may contribute to SRSF2 leukemic pathogenesis, the biologic consequences of SRSF2 mutation have not been fully elucidated and its effect on non-splicing pathways has yet to be explored.SRSF2 has two major functions within the nucleus: (1) bind to cis elements on pre-mRNA transcripts that functionally redefines putative exon-intron boundaries and (2) interact with other members of the spliceosome complex at nuclear suborganelles known as speckles. To explore the effects of SRSF2 P95 mutation on nuclear speckle dynamics, we transfected HeLa cells with GFP-SRSF2 wildtype (WT) and mutant (MT) constructs and performed Fluorescent Recovery After Photo-bleaching (FRAP) to determine the mutant specific kinetics of SRSF2 molecules localized to the nuclear speckle. Using this approach, we confirmed that SRSF2 WTs are characterized by complete photo-recovery with a half-life of approximately 35 (30-42) seconds as previously reported. However, when we performed FRAP of GFP-SRSF2 MTs a statistically significant difference in photo-recovery was observed compared to WT cells (Fig. 1a). The difference between baseline fluorescence and maximal recovered fluorescence in SRSF2 MT cells, or the immobile fraction, suggests that trapped bleached SRSF2 molecules are sterically inhibiting the diffusion of unbleached SRSF2 molecules.We reasoned that the observed differences in RNA binding capacity and nuclear speckle dynamics could be related. This rationale identified MALAT1 as a link connecting both increased RNA binding and nuclear speckle trafficking abnormalities because it is a Long Non-Coding (lnc) RNA that localizes to and has a critical role in SR protein recruitment and retention to the nuclear speckle. MALAT1, which is highly enriched for CCNG motifs, has also been demonstrated to bind to SRSF2 directly and has been implicated in a wide spectrum of carcinomas making it an attractive intermediary to study in our system.To determine whether SRSF2 MTs have increased MALAT1 binding capacity compared to SRSF2 WT, we performed RNA IP of myc-his-SRSF2 WT and MT transfected HeLa cells. Using this approach, we demonstrated a 60% enrichment of MALAT1 in SRSF2 WT transfected cells and a 120-150% enrichment of MALAT1 in SRSF2 MT cells compared to the empty vector control (Fig. 1b-c). We next performed the above FRAP experiment in the context of MALAT1 depletion and demonstrated that observed immobile fraction seen in SRSF2 MT cells is rescued (Fig. 1d).To determine the clinical relevance of MALAT1 in CMML we profiled a cohort of 54 CMML cases for MALAT1 expression by PCR. As shown in Figure 2a-b and d-e, MALAT1 expression is statistically elevated in CMML BMNCs and is among the highest differentially expressed transcripts in CMML monocytes (CD14+). We additionally characterized SRSF2 expression in our CMML BMNCs and CD14+ cohort and identified a linear correlation (Pearson R=0.7 p<0.05) between SRSF2 expression and MALAT1 expression (Figure 2c). Further, CMML patients with high MALAT1 expression in the BMNC compartment had inferior overall and leukemia-free survival (Fig. 2f-g).Given its relevance in solid tumors and its over-expression in CMML, we explored the consequence of MALAT1 depletion on human monocytic leukemic cells. We first performed ultra-deep RNA sequencing of the THP-1 cell line treated with two MALAT-1 depleting ASOs or matched chemistry specific controls. IPA analysis of differentially expressed transcripts identified a c-Myc gene signature that was validated by western blot analysis demonstrating reduction of c-Myc in THP-1 MALAT1-depleted cells. Colony formation assays using the THP-1 cell line demonstrated that MALAT-1 depletion resulted in decreased colony-forming capacity (CFC). MALAT-1 ASOs were also capable of depleting MALAT-1 in primary CMML BMNCs and were associated with a decreased CFC suggesting that MALAT-1 is a potential therapeutic target. Taken together, our data identifies SRSF2 P95 mutation nuclear trafficking abnormalities and identifies a novel clinically relevant lncRNA in CMML. [Display omitted] [Display omitted] DisclosuresKomrokji:Celgene: Consultancy, Research Funding; Incite: Consultancy; Novartis: Speakers Bureau; GSK: Research Funding. List:Celgene Corporation: Honoraria, Research Funding.

Structural analysis of xSrO–(50 − x)CaO–50P 2 O 5 glasses with x = 0, 5, or 10 mol% for potential use in a local delivery system for osteomyelitis treatment

The introduction of ions into a local delivery matrix is one method of managing degradation and subsequent release of the incorporated therapeutic agents. Of interest in this study was whether we could modify the structural nature of calcium polyphosphate (CPP) glass and the subsequent therapeutic potential of this local delivery matrix with inclusion of strontium (Sr). We found that adding 10 mol% Sr significantly increased the density and chain length of the glass. There was no significant impact of Sr doping on the subsequent loading of vancomycin into the matrix, or the matrix porosity. The noted differences in structural stability, ion release, and vancomycin release between the un-doped CPP matrices and 10 mol% Sr-doped CPP matrices in vitro are likely a result of a decrease in glass disorder upon Sr addition to the glass and preferential retention of Sr over Ca during matrix degradation. This study has provided further evidence that Sr incorporation may serve to both manipulate antibiotic release from the amorphous CPP matrix and provide a potential source of therapeutic ions for enhanced bone regeneration.

Mineralogical and Geochemical Characteristics and Genesis of the Gülzelyurt Alunite-Bearing Kaolinite Deposit Within the Late Miocene Gödeles Ignimbrite, Central Anatolia, Turkey

AbstractThe Güzelyurt kaolinite deposit is an important source of raw material for the ceramics industry in Turkey. No detailed mineralogical or geochemical characterizations of this deposit have been undertaken previously and these were the goals of the present study. The Güzelyurt alunite-bearing kaolinite occurs along a fault zone in the Late Miocene Gödeles ignimbrite, which consists of dacitic and andesitic tuffs. Horizontal and vertical mineralogical zonations with gradual transitions were observed within the alteration zone. The inner kaolinite, alunite, and 7 Å halloysite zones progress horizontally outward to a smectite zone; and native sulfur- and cinnabar-bearing alunite with 7 Å halloysite and porous silica zones increase as one progresses up through the profile. Fe-(oxyhydr)oxide phases associated with native sulfur and cinnabar demonstrate that multiple hydrothermal-alteration processes resulted in kaolinization and alunitization of the deposit. The kaolinization of feldspar, Fe-(oxyhydr)oxidation of hornblende and mica, the presence of kaolinite as stacked and, locally, book-like forms, and of 7 Å halloysite tubes, and smectite flakes as a blanket on altered volcanic relicts indicate an authigenic origin for this deposit. The leaching of Si + Mg + K and Ba + Rb, the retention of Sr, the enrichment of light rare earth elements relative to the heavy rare earth elements, and the negative Eu anomalies suggest that fractionation of plagioclase and hornblende occurred within the volcanics. The oxygen- and hydrogen-isotopic values of the kaolinite, 7 Å halloysite, smectite, and smectite + kaolinite fractions reflect a steam-heated environment at temperatures in excess of 100°C. An increase in the δD and δ18O values of 7 Å halloysite relative to kaolinite suggests its formation under steam-heated magmatic water, the mixing of steam and meteoric water near the surface, and evaporation. The oxygen- and sulfur-isotopic compositions of alunite suggest the direct influence of steam-derived sulfur. The Güzelyurt alunite-bearing kaolinite deposit is inferred to have formed after an increase in the (Al±Fe)/Si ratio and the leaching of alkali elements, which are driven by the sulfur-bearing low-temperature hydrothermal alteration of feldspar, hornblende, and volcanic glass under acidic conditions within the Neogene dacitic and andesitic tuffs.

Effect of water content on strontium retardation factor and distribution coefficient in Chinese loess

Geological burial and landfill are often employed for disposal of nuclear wastes. Typically, radionuclides from nuclear facilities transport through the unsaturated zone before reaching the groundwater aquifer. However, transport studies are often conducted under saturated and steady-state flow conditions. This research aimed to examine the effects of unsaturated flow conditions and soil water content (θ) on Sr sorption and retardation in Chinese loess through 1D column transport experiments. Reagent SrCl2 was used as a surrogate for the radioactive isotope (90Sr) in the experiment because of their analogous adsorption and transportation characteristics. The spatial distribution of Sr along the column length was determined by segmenting the soil bed and analysing the Sr content in each soil segment following each column breakthrough test. The single-region (SR) and two-region (TR) models were employed to interpret the transport data of Sr as well as a tracer (Br−), which resulted in the dispersion coefficient (D) and retardation factor (Rd) under a given set of unsaturated flow conditions. For the tracer, the SR and TR models offered nearly the same goodness of fitting to the breakthrough curves (R2 ≈ 0.97 for both models). For the highly sorptive Sr, however, the TR model provided better fitting (R2, 0.80–0.96) to the Sr retention profiles than the SR model (R2, 0.20–0.89). The Sr retention curves exhibited physical non-equilibrium characteristics, particularly at lower water content of the soil. For the unsaturated soil, D and the pore water velocity (v) displayed a weak linear correlation, which is attributed to the altering dispersivity as the water content varies. A much improved linear correlation was observed between D and v/θ. The retardation factor of Sr increased from 69.1 to 174.2 as θ decreased from 0.46 to 0.26 (cm3 cm−3), while the distribution coefficient (Kd) based on Rd remained nearly unchanged at various θ levels. These results illustrated that water content must be taken into account in determining radionuclide Rd values in Chinese loess, while Kd values can be derived from the unsaturated column experiments and can be considered constant at various levels of θ.