The carbonization of aromatic molecules with three-dimensional structures affords carbon materials with controlled pore sizes at the Ångstrom-level

分子構造により細孔径を制御したカーボンを開発. 京都大学プレスリリース. 2021-05-24.Carbon materials with controlled pore sizes at the nanometer level have been obtained by template methods, chemical vapor desorption, and extraction of metals from carbides. However, to produce porous carbons with controlled pore sizes at the Ångstrom-level, syntheses that are simple, versatile, and reproducible are desired. Here, we report a synthetic method to prepare porous carbon materials with pore sizes that can be precisely controlled at the Ångstrom-level. Heating first induces thermal polymerization of selected three-dimensional aromatic molecules as the carbon sources, further heating results in extremely high carbonization yields (>86%). The porous carbon obtained from a tetrabiphenylmethane structure has a larger pore size (4.40 Å) than those from a spirobifluorene (4.07 Å) or a tetraphenylmethane precursor (4.05 Å). The porous carbon obtained from tetraphenylmethane is applied as an anode material for sodium-ion battery

Rotulagem ambiental tipo I: sustentabilidade e competitividade para produtos e serviços brasileiros

O curso Rotulagem Ambiental Tipo I: sustentabilidade e competitividade para produtos e serviços brasileiros foi desenvolvido em 2020 pela Enap, em parceria com a Secretaria Especial de Produtividade Desenvolvimento da Indústria, Comércio, Serviços e Inovação do Ministério da Economia. O objetivo do curso é capacitar agentes econômicos da indústria e comércio em rotulagem ambiental, destacando seus tipos e programas, as vantagens sócio-econômico-ambientais e as oportunidades de negócios envolvidos.Módulo 1 – Contextualização da Rotulagem Ambiental Tipo I, 68 páginasMódulo 2 – A Rotulagem Ambiental Tipo I, 47 páginasMódulo 3 – Estudos de Casos, 15 páginasMódulo 4 – Estratégia para a Rotulagem Ambiental Tipo I de Produtos e de Serviços no Brasil, 21 páginasDesenvolvimento SustentávelInovaçãoPolíticas Pública

UVA1 genotoxicity is mediated not by oxidative damage but by cyclobutane pyrimidine dimers in normal mouse skin

UVA1 induces the formation of 8-hydroxy-2′-deoxyguanosines (8-OH-dGs) and cyclobutane pyrimidine dimers (CPDs) in the cellular genome. However, the relative contribution of each type of damage to the in vivo genotoxicity of UVA1 has not been clarified. We irradiated living mouse skin with 364-nm UVA1 laser light and analyzed the DNA damage formation and mutation induction in the epidermis and dermis. Although dose-dependent increases were observed for both 8-OH-dG and CPD, the mutation induction in the skin was found to result specifically from the CPD formation, based on the induced mutation spectra in the skin genome: the dominance of C → T transition at a dipyrimidine site. Moreover, these UV-specific mutations occurred preferentially at the 5′-TCG-3′ sequence, suggesting that CpG methylation and photosensitization-mediated triplet energy transfer to thymine contribute to the CPD-mediated UVA1 genotoxicity. Thus, it is the CPD formation, not the oxidative stress, that effectively brings about the genotoxicity in normal skin after UVA1 exposure. We also found differences in the responses to the UVA1 genotoxicity between the epidermis and the dermis: the mutation induction after UVA1 irradiation was suppressed in the dermis at all levels of irradiance examined, whereas it leveled off from a certain high irradiance in the epidermis

Gain measurement of 10.6 μm Co2 gasdynamic laser driven by high temperature reaction of CO-N2O-H2 in shock tube

Basic study of CO\_2_ gasdynamic laser (GDL) was carried out by a conventional pressure driven shock tube equipped with a supersonic nozzle section. Population inversion of the vibrational levels of CO\_2_ in an expanding flow of mixture produced by high temperature reaction of CO-N\_2_O-H\_2\ system behind a shock wave was observed by measuring 10.6\mu\m small-single-gain. The experimental date were compared with those obtained by computer simulation assuming quasi-one-dimensional steady flow in the nozzle and three vibrational mode model. As a reservoir condition in the simulation, kinetics of Co\_2_ formation in CO-N\_2_O-H\_2\ system behind the reflected shock wave was discussed

The mEPN scheme: an intuitive and flexible graphical system for rendering biological pathways

<p>Abstract</p> <p>Background</p> <p>There is general agreement amongst biologists about the need for good pathway diagrams and a need to formalize the way biological pathways are depicted. However, implementing and agreeing how best to do this is currently the subject of some debate.</p> <p>Results</p> <p>The modified Edinburgh Pathway Notation (mEPN) scheme is founded on a notation system originally devised a number of years ago and through use has now been refined extensively. This process has been primarily driven by the author's attempts to produce process diagrams for a diverse range of biological pathways, particularly with respect to immune signaling in mammals. Here we provide a specification of the mEPN notation, its symbols, rules for its use and a comparison to the proposed Systems Biology Graphical Notation (SBGN) scheme.</p> <p>Conclusions</p> <p>We hope this work will contribute to the on-going community effort to develop a standard for depicting pathways and will provide a coherent guide to those planning to construct pathway diagrams of their biological systems of interest.</p

A novel G-quadruplex-forming GGA repeat region in the c-myb promoter is a critical regulator of promoter activity

The c-myb promoter contains multiple GGA repeats beginning 17 bp downstream of the transcription initiation site. GGA repeats have been previously shown to form unusual DNA structures in solution. Results from chemical footprinting, circular dichroism and RNA and DNA polymerase arrest assays on oligonucleotides representing the GGA repeat region of the c-myb promoter demonstrate that the element is able to form tetrad:heptad:heptad:tetrad (T:H:H:T) G-quadruplex structures by stacking two tetrad:heptad G-quadruplexes formed by two of the three (GGA)4 repeats. Deletion of one or two (GGA)4 motifs destabilizes this secondary structure and increases c-myb promoter activity, indicating that the G-quadruplexes formed in the c-myb GGA repeat region may act as a negative regulator of the c-myb promoter. Complete deletion of the c-myb GGA repeat region abolishes c-myb promoter activity, indicating dual roles of the c-myb GGA repeat element as both a transcriptional repressor and an activator. Furthermore, we demonstrated that Myc-associated zinc finger protein (MAZ) represses c-myb promoter activity and binds to the c-myb T:H:H:T G-quadruplexes. Our findings show that the T:H:H:T G-quadruplex-forming region in the c-myb promoter is a critical cis-acting element and may repress c-myb promoter activity through MAZ interaction with G-quadruplexes in the c-myb promoter

Restoration of IFNγR Subunit Assembly, IFNγ Signaling and Parasite Clearance in Leishmania donovani Infected Macrophages: Role of Membrane Cholesterol

Despite the presence of significant levels of systemic Interferon gamma (IFNγ), the host protective cytokine, Kala-azar patients display high parasite load with downregulated IFNγ signaling in Leishmania donovani (LD) infected macrophages (LD-MØs); the cause of such aberrant phenomenon is unknown. Here we reveal for the first time the mechanistic basis of impaired IFNγ signaling in parasitized murine macrophages. Our study clearly shows that in LD-MØs IFNγ receptor (IFNγR) expression and their ligand-affinity remained unaltered. The intracellular parasites did not pose any generalized defect in LD-MØs as IL-10 mediated signal transducer and activator of transcription 3 (STAT3) phosphorylation remained unaltered with respect to normal. Previously, we showed that LD-MØs are more fluid than normal MØs due to quenching of membrane cholesterol. The decreased rigidity in LD-MØs was not due to parasite derived lipophosphoglycan (LPG) because purified LPG failed to alter fluidity in normal MØs. IFNγR subunit 1 (IFNγR1) and subunit 2 (IFNγR2) colocalize in raft upon IFNγ stimulation of normal MØs, but this was absent in LD-MØs. Oddly enough, such association of IFNγR1 and IFNγR2 could be restored upon liposomal delivery of cholesterol as evident from the fluorescence resonance energy transfer (FRET) experiment and co-immunoprecipitation studies. Furthermore, liposomal cholesterol treatment together with IFNγ allowed reassociation of signaling assembly (phospho-JAK1, JAK2 and STAT1) in LD-MØs, appropriate signaling, and subsequent parasite killing. This effect was cholesterol specific because cholesterol analogue 4-cholestene-3-one failed to restore the response. The presence of cholesterol binding motifs [(L/V)-X1–5-Y-X1–5-(R/K)] in the transmembrane domain of IFNγR1 was also noted. The interaction of peptides representing this motif of IFNγR1 was studied with cholesterol-liposome and analogue-liposome with difference of two orders of magnitude in respective affinity (KD: 4.27×10−9 M versus 2.69×10−7 M). These observations reinforce the importance of cholesterol in the regulation of function of IFNγR1 proteins. This study clearly demonstrates that during its intracellular life-cycle LD perturbs IFNγR1 and IFNγR2 assembly and subsequent ligand driven signaling by quenching MØ membrane cholesterol