Transition-Metal-Free Aluminosilicate Small-Pore Zeolites Upgrade Methane to Light Olefins.

Upgrading methane to value-added chemicals is significant but still challenging. Well-designed catalysts are required to activate methane. Extensive efforts have been dedicated to the catalytic conversion of methane over transition-metal-containing catalysts.

Aluminum Distribution in Ferrierite Zeolites Influences the Performance of Methane Oxidation.

Transition-metal-free aluminosilicate FER-type zeolite has been demonstrated to effectively catalyze methane to methanol using NO as the oxidant with distorted tetra-coordinated aluminum (Al) and penta-coordinated aluminum (Al) as potential active sites. However, the specific effects of Al distribution on the active Al species have not been thoroughly investigated. Herein, aluminosilicate FER-type zeolites with controllable Al distribution were developed.

Revealing Active Sites and Reaction Pathways in Direct Oxidation of Methane over Fe-Containing CHA Zeolites Affected by the Al Arrangement.

Fe-containing zeolites are effective catalysts in converting the greenhouse gases CH and NO into valuable chemicals. However, the activities of Fe-containing zeolites in methane conversion and NO decomposition are frequently conflated, and the activities of different Fe species are still controversial. Herein, Fe-containing aluminosilicate CHA zeolites with Fe species at different spatial distances affected by the arrangement of framework Al atoms were synthesized in a one-pot manner in the presence or absence of Na.

Direct Oxidation of Methane to Methanol over Transition-Metal-Free Ferrierite Zeolite Catalysts.

Direct oxidation of methane to methanol was reported to be highly dependent on the transition- or noble-metal-loading catalysts in the past decades. Here, we show that the transition-metal-free aluminosilicate ferrierite (FER) zeolite effectively catalyzed methane and NO to methanol for the first time. The distorted tetracoordinated Al in the framework and pentacoordinated Al on the extra framework formed during calcination, activation, and reaction processes were confirmed as the potential active centers.

Understanding the effect of spatially separated Cu and acid sites in zeolite catalysts on oxidation of methane.

Unraveling the effect of spatially separated bifunctional sites on catalytic reactions is significant yet challenging. In this report, we investigate the role of spatial separation on the oxidation of methane in a series of Cu-exchanged aluminosilicate zeolites. Regulation of the bifunctional sites is done either through studying a physical mixture of Cu-exchanged zeolites and acidic zeolites or by systematically varying the Cu and acid density within a family of zeolite materials.

Accelerated Fear Extinction by Regular Light-Intensity Exercise: A Possible Role of Hippocampal BDNF-TrkB Signaling.

Purpose: Growing concern exists worldwide about stress-related mental disorders, such as posttraumatic stress disorder (PTSD), often linked to hippocampal dysfunctions. Recognizing this connection, regular light-intensity exercise (LIE)-such as yoga, walking, or slow jogging-may offer a solution. Easily accessible even to vulnerable individuals, LIE has been found to enhance hippocampus-based cognitive functions through the stimulation of neurotrophic factors like brain-derived neurotrophic factor (BDNF).

Influence of non-uniform flow on toxic elements transport in soil column percolation test.

The influence of flow channels on the leaching behavior of toxic elements in contaminated soil cannot be neglected in a column percolation test. This study presents a visualization of the flow channel formed in the soil and evaluated the relationship between the leaching behavior of soil components and flow. We conducted column percolation tests with two types of filling methods (Compaction and No compaction) and used X-ray computed tomography to visualize the soil structure and non-uniform flow.

Role of water in unexpectedly large changes in emission flux of volatile organic compounds in soils under dynamic temperature conditions.

Understanding the diffusive transport behavior of volatile organic compounds (VOCs) in near-surface soils is important because soil VOC emissions affect atmospheric conditions and climate. Previous studies have suggested that temperature changes affect the transport behavior; however, the effect of these changes are poorly understood. Indeed, under dynamic temperature conditions, the change in VOC flux is much larger than that expected from the temperature dependency of the diffusion coefficient of VOCs in air.

Potentially toxic elements pose significant and long-term human health risks in river basin districts with abandoned gold mines.

Gold (Au) mining area is known to be one of the major sources of toxic elements; however, the potential risks of toxic elements from abandoned Au mines to the surrounding river basin districts and human exposure pathways to toxic elements need to be clarified. In this study, the distribution and mobilities of nine toxic elements (As, Cd, Cu, Pb, Sb, Zn, Cr, Ni and V) in Kesennuma City, Tohoku Region in Japan, a typical Au-mining district with several river basins, were studied through a geochemical survey (including element total concentrations and water-/acid-leaching concentrations determinations, as well as GB calculations), and environmental assessment on these elements in soil, river sediment, and river water samples from the study area. The contamination evaluation by index of geo-accumulation (I) and enrichment factor (EF) suggested that As, Cu, Ni and Sb enrichments were greatly observed in the vicinity of the abandoned Au mines; moreover, calculated GB upper values for Cu in the river sediment surpass that of Tohoku Region.

Novel chemical stimulation for geothermal reservoirs by chelating agent driven selective mineral dissolution in fractured rocks.

Improving geothermal systems through hydraulic stimulation to create highly permeable fractured rocks can induce seismicity. Therefore, the technique must be applied at a moderate intensity; this has led to concerns of insufficient permeability enhancement. Adding chemical stimulation can mitigate these issues, but traditional methods using strong mineral acids have challenges in terms of achieving mineral dissolution over long distances and highly variable fluid chemistry.

Dynamic evaluation method for planning sustainable landfills using GIS and multi-criteria in areas of urban sprawl with land-use conflicts.

Landfill site selection is problematic in many countries, especially developing nations where there is rapid population growth, which leads to high levels of inadequate waste disposal. To find sustainable landfill sites in sprawling cities, this study presents an approach that combines geographic information system (GIS) with multi-criteria (social, environmental and, technical criteria) and the population growth projection. The greater Maputo area in Mozambique was selected as a representative city for the study, which is undergoing rapid urbanization.

Enhancement of aragonite mineralization with a chelating agent for CO storage and utilization at low to moderate temperatures.

Among the CaCO polymorphs, aragonite demonstrates a better performance as a filler material in the paper and plastic industries. Despite being ideal from the environmental protection perspective, the production of aragonite particles via CO mineralization of rocks is hindered by the difficulty in achieving high production efficiencies and purities, which, however, can be mitigated by exploiting the potential ability of chelating agents on metal ions extraction and carbonation controlling. Herein, chelating agent N,N-dicarboxymethyl glutamic acid (GLDA) was used to enhance the extraction of Ca from calcium silicate and facilitate the production of aragonite particles during the subsequent Ca carbonation.

Using data-driven analysis of geochemical environmental information to infer the environmental impact of closed mines.

River sediments have the effect of aggregating geochemical environmental information, such as that related to geological and artificial pollution resulting from mine closure. This information comprises high-dimensional data and is related to the distribution and quantities of elements in river sediments. However, accessing and interpreting this geochemical information can be difficult.

Leaching of As and Se from coal fly ash: fundamental study for coal fly ash recycling.

Coal fly ash (CFA) is a useful recycled resource for uses such as cement raw material. To manage and evaluate safety for effective utilization of CFA, the leaching concentration and amounts of toxic elements in CFA need to be determined. In this study, 38 types of CFA and aged CFA generated in Japan were used to measure the occurrence and leaching concentration range of As and Se.

A public health collaboration between medical professionals and Japan's professional football league for rubella awareness.

A public health collaboration between medical professionals and Japan's professional football league for rubella awareness.

Formation of amorphous silica nanoparticles and its impact on permeability of fractured granite in superhot geothermal environments.

Superhot geothermal environments in granitic crusts of approximately 400-500 °C are a frontier of geothermal energy. In the development of such environments, there is a concern of a reduction of permeability of fractured granite due to the formation of fine particles of amorphous silica induced by the phase change from subcritical water to supercritical water or superheated steam. However, the formation of silica particles and a resultant reduction in permeability have not been demonstrated to date.

Data-driven analysis for source apportionment and geochemical backgrounds establishment of toxic elements and REEs in the Tohoku region, Japan.

The Tohoku region of Japan is geologically diverse, with a long agriculture and mining history; however, little information about the origins and distribution mechanisms of elements in this region has been reported. This study aims to provide fundamental insights into the effects of geological features and anthropogenic activities on various elements, including toxic elements and rare-earth elements (REEs), in the Tohoku region. A geochemical database (2007, AIST) consisting of data for 53 elements in 485 river sediment samples from the region was used, and a data-driven method combining principal component analysis (PCA) was applied for analysis.

Development of a predictive model for lead, cadmium and fluorine soil-water partition coefficients using sparse multiple linear regression analysis.

In this study, we applied sparse multiple linear regression (SMLR) analysis to clarify the relationships between soil properties and adsorption characteristics for a range of soils across Japan and identify easily-obtained physical and chemical soil properties that could be used to predict K and n values of cadmium, lead and fluorine. A model was first constructed that can easily predict the K and n values from nine soil parameters (pH, cation exchange capacity, specific surface area, total carbon, soil organic matter from loss on ignition and water holding capacity, the ratio of sand, silt and clay). The K and n values of cadmium, lead and fluorine of 17 soil samples were used to verify the SMLR models by the root mean square error values obtained from 512 combinations of soil parameters.

Extraction of heavy metals characteristics of the 2011 Tohoku tsunami deposits using multiple classification analysis.

Tsunami deposits accumulated on the Tohoku coastal area in Japan due to the impact of the Tohoku-oki earthquake. In the study reported in this paper, we applied principal component analysis (PCA) and cluster analysis (CA) to determine the concentrations of heavy metals in tsunami deposits that had been diluted with water or digested using 1 M HCl. The results suggest that the environmental risk is relatively low, evidenced by the following geometric mean concentrations: Pb, 16 mg kg(-1) and 0.

Human leukocyte antigen haplotype and autoantibodies of a family with systemic lupus erythematosus.

A search for HLA haplotypes of a family of five indicated that four members had the same haplotype. Systemic lupus erythematosus (SLE) had already developed in three of these four people. SLE has now developed in the remaining person, and the result is that all the members of the family having the same haplotype will develop SLE.

Prostaglandin E2 is a negative regulator on human plasmacytoid dendritic cells.

Prostaglandin E2 (PGE2), a major lipid derived from the metabolism of arachidonic acid, is an environmentally bioactive substance produced by inflammatory processes and acts as a cAMP up-regulator that plays an important role in immune responses. It has been reported that PGE2 has the ability to inhibit the production of interleukin-12 by myeloid dendritic cells (MDCs) and macrophages, and then induce preferential T helper type 2 (Th2) cell responses. However, little is known of the function of PGE2 for plasmacytoid dendritic cells (PDCs), which may contribute to the innate and adaptive immune response to viral infection, allergy and autoimmune diseases.

Plasmacytoid dendritic cells regulate Th cell responses through OX40 ligand and type I IFNs.

Dendritic cells (DCs) show a functional plasticity in determining Th responses depending on their maturational stage or on maturational signals delivered to the DCs. Human plasmacytoid DCs (PDCs) can induce either Th1- or Th2-type immune responses upon exposure to viruses or IL-3, respectively. In this study we have investigated the Th-polarizing capacity of PDCs after short (24-h) or long (72-h) culture with stimuli and have assessed the expression and function of OX40 ligand (OX40L) in PDC-mediated Th polarization in addition to type I IFN-dependent responses.