The Crustal and Uppermost Mantle Vs Structure of the Middle and Lower Reaches of the Yangtze River Metallogenic Belt:Implications for Metallogenic Process

The Middle and Lower Reaches of the Yangtze River metallogenic belt (MLYMB) is one of the most important Fe-Cu polymetallic belts in China. However, the mechanism and deep geodynamical process for the formation of this belt are still controversial. Here, we obtain the crustal and the uppermost mantle structures using ambient noise data from a dense seismic profile. A low velocity zone is revealed beneath the Moho of MLYMB, interpreted as the source of the deep mineralization materials. In addition, a low velocity layer (LVL) and a high velocity layer (HVL) are observed in the crust of the southern segment of the profile. The LVL is interpreted as a tectonic detachment layer between the upper and the lower crust, and the HVL is interpreted as the aggregation zone for mineralizing melts or crystallized magma chambers. Based on the observed velocity features, we propose a three-stage model for the formation of ore deposits in MLYMB. Our model suggests that an upwelling of asthenosphere triggered by the delamination of a previously thickened lithosphere leads to the partial melting of upper mantle rocks, which eventually ponders under the Moho. The magma then infiltrates through the ductile lower crust and reaches a depth of ∼7–13 km, forming a minerals-enriched magma chamber. Minerals-rich hot fluids originating from the magma chamber continue to move upward along the pre-existent faults and the minerals finally precipitate in dense veinlets when reaching shallow depths, forming the ore deposits in and around the MLYMB.</p

The influence of highly dispersed Cu2O-anchored MoS2 hybrids on reducing smoke toxicity and fire hazards for rigid polyurethane foam.

The extensive utilization of rigid polyurethane foam (RPUF) as construction insulation material has brought two main troubles to our society: fire risks and toxic hazards. To reduce the fire hazards of RPUF, a layered MoS2 decorated with Cu2O nanoparticles was creativity obtained by hydrothermal technology and facile wet chemical treatment for reducing the toxic product formations of polyurethane nanocomposites during combustion. Due to the low weight ratio of Cu2O attached onto MoS2, the resulting Cu2O-MoS2 hybrid effectively prevented the MoS2 nanosheets from restacking. However, the Cu2O-MoS2-M hybrid was produced by increasing content of Cu2O, which has the characteristic stacked layer structure of MoS2. Reduced harmful organic volatiles and the toxic gases (e.g. a respective decrease of ca. 28% and 53% for CO and NOx products) were obtained because of synergistic effect between the physical adsorption of MoS2 and catalysis action of Cu2O. Notably, the addition of Cu2O-MoS2 hybrids led to high char formation of the RPUF nanocomposite, indicating the effectively catalytic carbonization property. In addition, the N-Gas model for predicting fire smoke toxicity was developed and demonstrated. Furthermore, the research offers direct proofs of the negative influence of the stacked MoS2 on reducing the smoke toxicity for RPUF nanocomposites

Facile synthesis of aluminum branched oligo(phenylphosphonate) submicro-particles with enhanced flame retardance and smoke toxicity suppression for epoxy resin composites.

A novel and submicro-scale aluminum branched oligo(phenylphosphonate) (AHPP) has been successfully synthesized and embedded into a polymeric substrate to improve the fire safety of epoxy resin (EP). The chemical structures of intermediates and target products were characterized using the nuclear magnetic resonance spectroscopy, X-ray diffraction and Fourier transform infrared analysis. Morphology analysis confirmed that all of the as-synthesized AHPP submicro-particles are mutually well-separated. Combustion results demonstrated that the limiting oxygen index value is increased to 30.5% from 23.5% while the PHRR and THR are decreased by ca. 68.1% and 41.2%, respectively for the EP/AHPP-7.5 composite compared to the corresponding values for pure EP. In addition, the binary blends display the satisfying smoke toxicity suppression performance during combustion. The total smoke production and the total CO yield for EP/AHPP-7.5 are dramatically reduced by 62.0% and 32.3%, respectively, which may mainly be ascribed to the catalytic carbonization performance of the polymers and formation of Al2O3 layers on the surface of the char residues. As a result, the findings in this study enabled the submicro-scale phosphorus-containing flame retardant to be a potential candidate as an efficient additive for reducing smoke toxicity of polymer composites

Facile synthesis of aluminum branched oligo(phenylphosphonate) submicro-particles with enhanced flame retardance and smoke toxicity suppression for epoxy resin composites

Abstract(#br)A novel and submicro-scale aluminum branched oligo(phenylphosphonate) (AHPP) has been successfully synthesized and embedded into a polymeric substrate to improve the fire safety of epoxy resin (EP). The chemical structures of intermediates and target products were characterized using the nuclear magnetic resonance spectroscopy, X-ray diffraction and Fourier transform infrared analysis. Morphology analysis confirmed that all of the as-synthesized AHPP submicro-particles are mutually well-separated. Combustion results demonstrated that the limiting oxygen index value is increased to 30.5% from 23.5% while the PHRR and THR are decreased by ca. 68.1% and 41.2%, respectively for the EP/AHPP-7.5 composite compared to the corresponding values for pure EP. In addition, the binary blends display the satisfying smoke toxicity suppression performance during combustion. The total smoke production and the total CO yield for EP/AHPP-7.5 are dramatically reduced by 62.0% and 32.3%, respectively, which may mainly be ascribed to the catalytic carbonization performance of the polymers and formation of Al 2 O 3 layers on the surface of the char residues. As a result, the findings in this study enabled the submicro-scale phosphorus-containing flame retardant to be a potential candidate as an efficient additive for reducing smoke toxicity of polymer composites

Unfaithful Maintenance of Methylation Imprints Due to Loss of Maternal Nuclear Dnmt1 during Somatic Cell Nuclear Transfer

The low success rate of somatic cell nuclear transfer (SCNT) in mammalian cloning is largely due to imprinting problems. However, little is known about the mechanisms of reprogramming imprinted genes during SCNT. Parental origin-specific DNA methylation regulates the monoallelic expression of imprinted genes. In natural fertilization, methylation imprints are established in the parental germline and maintained throughout embryonic development. However, it is unclear whether methylation imprints are protected from global changes of DNA methylation in cloned preimplantation embryos. Here, we demonstrate that cloned porcine preimplantation embryos exhibit demethylation at differentially methylated regions (DMRs) of imprinted genes; in particular, demethylation occurs during the first two cell cycles. By RNAi-mediated knockdown, we found that Dnmt1 is required for the maintenance of methylation imprints in porcine preimplantation embryos. However, no clear signals were detected in the nuclei of oocytes and preimplantation embryos by immunofluorescence. Thus, Dnmt1 is present at very low levels in the nuclei of porcine oocytes and preimplantation embryos and maintains methylation imprints. We further showed that methylation imprints were rescued in nonenucleated metaphase II (MII) oocytes. Our results indicate that loss of Dnmt1 in the maternal nucleus during SCNT significantly contributes to the unfaithful maintenance of methylation imprints in cloned embryos

Expert Consensus on Microtransplant for Acute Myeloid Leukemia in Elderly Patients -Report From the International Microtransplant Interest Group

Recent studies have shown that microtransplant (MST) could improve outcome of patients with elderly acute myeloid leukemia (EAML). To further standardize the MST therapy and improve outcomes in EAML patients, based on analysis of the literature on MST, especially MST with EAML from January 1st, 2011 to November 30th, 2022, the International Microtransplant Interest Group provides recommendations and considerations for MST in the treatment of EAML. Four major issues related to MST for treating EAML were addressed: therapeutic principle of MST (1), candidates for MST (2), induction chemotherapy regimens (3), and post-remission therapy based on MST (4). Others included donor screening, infusion of donor cells, laboratory examinations, and complications of treatment

Hypophosphite/Graphitic Carbon Nitride Hybrids: Preparation and Flame-Retardant Application in Thermoplastic Polyurethane

A series of aluminum hypophosphite (AHPi)/graphite-like carbon nitride (g-C3N4) (designated as CAHPi) hybrids were prepared, followed by incorporation into thermoplastic polyurethane (TPU). The introduction of CAHPi hybrids into TPU led to a marked reduction in the peak of the heat release rate (pHRR), total heat release, weight loss rate, smoke production rate and total smoke production (TSP). For instance, pHRR and TSP decreased by 40% and 50% for TPU/CAHPi20. Furthermore, the increasing fire growth index and decreasing fire performance index were obtained for TPU/CAHPi systems, suggesting reduced fire hazards. It was found that improved fire safety of TPU nanocomposites was contributed by condensed phase and gas phase mechanisms. On one hand, g-C3N4 accelerated the thermal decomposition of AHPi for the formation of more char layers. On the other hand, g-C3N4 induced AHPi to generate more free radical capture agents when exposed to flame, besides protecting AHPi against thermal oxidation

Accumulation Characteristics of Metals and Metalloids in Plants Collected from Ny-Ålesund, Arctic

Toxic elements can be transported to polar regions by long-range atmospheric transport from mid and low latitudes, leading to enrichment of elements in the polar environment, especially in the Arctic. The plants can be ideal bioindicators of element contamination in environments, but information on the element enrichment and sources of plants remains limited in polar regions. Here, concentrations of 15 metals and metalloids (Pb, Ni, Cr, Cu, Co, As, Cd, Sb, Hg, Se, Fe, Zn, Mn, Al, and Ti) in six species of plants, Deschampsia caespitosa (Tufted Hair Grass), Puccinellia phryganodes (Creeping Alkaligrass), Saxifraga aizoides (Yellow Mountain Saxifrage), Dicranum angustum (Dicranum Moss), Salix Polaris (Polar Willow), and Cerastium arcticum (Arctic Mouse-Ear Chickweed), collected from Ny-&Aring;lesund, the Arctic, were determined, and enrichment and sources of elements were assessed. Results show that element concentrations vary in different plant species, and element levels in D. angustum and C. arcticum are generally higher. In spatial terms, elevated element concentrations were found near residential areas, while low element levels were present at the sites far from settlement points. Enrichment assessment shows that Cd, Hg, and Zn are the most enriched elements, with enrichment factors above 30, suggesting sources other than soil dust control their concentrations. Principal component analysis (PCA) showed that the extracted three components can explain 82% of the total variance in element concentrations. The elements Ni, Cr, As, Sb, Fe, Al, Ti, and to a lesser extent Co are highly loaded in PC1, possibly associated with continental crust particles. PC2 is closely correlated with Cd, Se, Mn, Cu, and Zn, while Hg and Pb have high loadings on PC3. The elements highly loaded on PC2 and PC3 are likely associated with pollutants from atmospheric transportation. Together with enrichment assessment, the investigated plants have a great potential for monitoring atmospheric Cd, Hg, and Zn pollution in Ny-&Aring;lesund, and D. angustum and D. caespitosa are the more sensitive species. The results would be of significance for monitoring element contamination in the pristine Arctic environments using the bioindicator plants