333 research outputs found

    Reduction of formaldehyde emission from plywood using composite resin composed of resorcinol–formaldehyde and urea-modified scallop shell nanoparticles

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    More than 200,000 tons of scallop shells are disposed annually 1 alone in Japan. Nanoparticles derived from scallop shells have the potential to adsorb gaseous formaldehyde; therefore such discarded shells have now been tested as additive filler in plywood adhesive by mixing high specific surface area, urea-modified shell nanoparticles with a resorcinol?formaldehyde resin; with this procedure it was found that the emission of formaldehyde from the resulting plywood could be substantially reduced. The urea-modified scallop shell nanoparticles were prepared by two different methods: (i) by a dry method in which the shells were treated with planetary ball-grinding under ambient conditions ? a completely dried powder was obtained after addition of the surface-modifying urea solution; (ii) by a moist method by treating dry-ground shell particles in a wet grinding process with the urea solution, followed by the use of centrifugation to obtain a paste. The specific surface area of the nanoparticles obtained by both treatments was 42 ± 3 m213 /g. Measurement of the subsequent formaldehyde emission showed that the addition of the modified scallop shell nanoparticles substantially reduced the formaldehyde emission from plywood; the reduction depends from the specific mass uptake of urea on the nanoparticles which especially was the case when resins containing nanoparticles processed by the moist method were used

    Production of thin graphite sheets for a high electrical conductivity film by the mechanical delamination of ternary graphite intercalation compounds

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    Herein we propose a production scheme for conductive films composed of thin graphite sheets with high crystallinity and polymeric resin. The crystalline graphite sheets were successfully produced from natural graphite powder by solution-phase synthesis of graphite intercalation compounds (GICs), following a wet planetary-ball milling under mild conditions. The shear forces in the milling pot lead to a peeling of graphite flakes. Taking into consideration the interlayer bonding force, the delamination should be preferentially done from the expanded GICs interlayer rather than intrinsic graphite one. Some composite films derived from the phenolic resin and flaky graphite sheets displayed much higher electrical conductivities compared to the film from the feed graphite particles. We also demonstrate the stage structure of synthetic GICs affected the film conductivity. The composite films made from exfoliated products of ground (around stage IV) GICs exhibited high electrical conductivity with a small amount of he graphite sheets

    ZFAT is an antiapoptotic molecule and critical for cell survival in MOLT-4 cells

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    AbstractZFAT (also known as ZNF406), originally identified as a candidate gene for autoimmune thyroid disease, encodes a zinc-finger protein, however, its function has not been elucidated. Here, we report that human ZFAT protein is expressed in peripheral B and T lymphocytes and a human acute T lymphoblastic leukaemia cell line, MOLT-4 cells. Intriguing is that mouse ZFAT expression in CD4+ lymphocytes is increased during blast formation. Furthermore, ZFAT-knockdown in MOLT-4 induces apoptosis via activation of caspases. These results suggested that ZFAT protein is a critical regulator involved in apoptosis and cell survival for immune-related cells

    Tespa1 is a novel inositol 1,4,5-trisphosphate receptor binding protein in T and B lymphocytes

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    AbstractTespa1 has been recently reported to be a critical molecule in T-cell development, however, the precise molecular mechanisms of Tespa1 remain elusive. Here, we demonstrate that Tespa1 shows amino-acid sequence homology to KRAS-induced actin-interacting protein (KRAP), an inositol 1,4,5-trisphosphate receptor (IP3R) binding protein, and that Tespa1 physically associates with IP3R in T and B lymphocytes. Two-consecutive phenylalanine residues (Phe185/Phe186) in Tespa1, which are conserved between Tespa1 and KRAP, are indispensable for the association between Tespa1 and IP3R. These findings suggest that Tespa1 plays critical roles in the immune system through the regulation of the IP3R

    Phase transformation of mesoporous calcium carbonate by mechanical stirring

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    We report a simple strategy to synthesize vaterite/calcite mesoporous calcium carbonate through collisions and organization of colloidal particles accelerated by mechanical stirring. Mechanically stirring the precursor colloidal dispersion can control the calcium carbonate polymorphs

    Scalable and template-free production of mesoporous calcium carbonate and its potential to formaldehyde adsorbent

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    Here we report a scalable and template-free production strategy 1 in the synthesis of a mesoporous calcium carbonate, which undergoes self-assembled nanostructure formation through a temperature-induced aggregation and polymorphic transformation of the colloids. The specific surface area and pore size distribution of resulting mesoporous calcium carbonate are clearly different depending on the aging temperature. The specific surface area and average pore size for aging temperature of 293 K are 207.3 ± 9.8 m2/g and 8.8±0.6 nm, respectively, and 65.1 ± 10.1 m2/g and 19.9±2.6 nm at 473 K. Additionally, we apply the mesoporous calcium carbonate powder to formaldehyde vapor adsorbent. We measure the adsorbed amount of gaseous formaldehyde and find that the vaterite-rich powder has larger adsorption per unit area than the calcite-rich one

    Inhibition of Phosphodiesterase-4 (PDE4) activity triggers luminal apoptosis and AKT dephosphorylation in a 3-D colonic-crypt model

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    BACKGROUND: We previously established a three-dimensional (3-D) colonic crypt model using HKe3 cells which are human colorectal cancer (CRC) HCT116 cells with a disruption in oncogenic KRAS, and revealed the crucial roles of oncogenic KRAS both in inhibition of apoptosis and in disruption of cell polarity; however, the molecular mechanism of KRAS-induced these 3-D specific biological changes remains to be elucidated. RESULTS: Among the genes that were upregulated by oncogenic KRAS in this model, we focused on the phosphodiesterase 4B (PDE4B) of which expression levels were found to be higher in clinical tumor samples from CRC patients in comparison to those from healthy control in the public datasets of gene expression analysis. PDE4B2 was specifically overexpressed among other PDE4 isoforms, and re-expression of oncogenic KRAS in HKe3 cells resulted in PDE4B overexpression. Furthermore, the inhibition of PDE4 catalytic activity using rolipram reverted the disorganization of HCT116 cells into the normal physiologic state of the epithelial cell polarity by inducing the apical assembly of ZO-1 (a tight junction marker) and E-cadherin (an adherens junction marker) and by increasing the activity of caspase-3 (an apoptosis marker) in luminal cavities. Notably, rolipram reduced the AKT phosphorylation, which is known to be associated with the disruption of luminal cavity formation and CRC development. Similar results were also obtained using PDE4B2-shRNAs. In addition, increased expression of PDE4B mRNA was found to be correlated with relapsed CRC in a public datasets of gene expression analysis. CONCLUSIONS: These results collectively suggested that PDE4B is upregulated by oncogenic KRAS, and also that the inhibition of PDE4 catalytic activity can induce both epithelial cell polarity and luminal apoptosis in CRC, thus highlighting the utility of our 3-D culture (3 DC) model for the KRAS-induced development of CRC in 3-D microenvironment. Indeed, using this model, we found that PDE4B is a promising candidate for a therapeutic target as well as prognostic molecular marker in CRC. Further elucidation of the signaling network of PDE4B2 in 3 DC would provide a better understanding of CRC in vivo
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