Inflammation Regulates Haematopoietic Stem Cells and Their Niche

Haematopoietic stem cells (HSCs) reside in the bone marrow and are supported by the specialised microenvironment, a niche to maintain HSC quiescence. To deal with haematopoietic equilibrium disrupted during inflammation, HSCs are activated from quiescence directly and indirectly to generate more mature immune cells, especially the myeloid lineage cells. In the process of proliferation and differentiation, HSCs gradually lose their self-renewal potential. The extensive inflammation might cause HSC exhaustion/senescence and malignant transformation. Here, we summarise the current understanding of how HSC functions are maintained, damaged, or exhausted during acute, prolonged, and pathological inflammatory conditions. We also highlight the inflammation-altered HSC niche and its impact on escalating the insults on HSCs.     

Computational fluid dynamics simulation and statistical procedure for estimating wide-area distributions of airborne sea salt considering local ground conditions

Steel corrosion under atmospheric conditions is a critical issue in the maintenance of structures such as electric transmission towers and bridges during their long-term operation, which are generally located at many places over a wide area. Since a major factor causing corrosion is airborne salt particles coming from the sea, wide-area distributions of the long-term cumulative amount of sea salt deposited on surfaces are needed. Moreover, since the amount of airborne sea salt varies locally with the topography, it is also important to consider the effects of topography. In this paper, a method combining a computational fluid dynamics model and a statistical procedure is proposed to efficiently estimate wide-area distributions of the cumulative amount of airborne sea salt by considering the local topography. The predicted amount of airborne sea salt decreases with increasing distance from the coast and varies with the topography and the offshore wind. A comparison between predicted and observed amounts revealed that: (1) this method appropriately estimates topographical effects on sea-salt transport and enables the estimation of deposited sea salt on structure surfaces, and (2) consideration of the trapping efficiency of sea-salt particles on structure surfaces improves the prediction accuracy.     

Graft copolymerization onto cellulose by ceric ion initiator system: Effects of kind of acid and irradiation with ultraviolet light

The effects of kind of acid and irradiation of ultraviolet light on the graft copolymerization of methyl methacrylate onto cellulose with adsorbed ceric ion were investigated. Irrespective of ultraviolet light irradiation, the amount of reduced ceric ion in the reaction systems was increased in the order HCl > HClO₄ > HNO₃ > H₂SO₄, and the number of grafts formed was increased in the order HClO₄ > HNO₃ > HCl > H₂SO₄. Thus, it was definitely observed that the graft copolymerization is affected by the kind of acid. Ultraviolet light remarkably accelerated the reduction of ceric ion adsorbed on cellulose in the various acid mediums, but decreased the efficiency of graft formation. The most favorable results for the formation of grafts were obtained in the system in which HClO₄ and ultraviolet irradiation was employed. A combination of H₂SO₄ and ultraviolet irradiation resulted in the lowest per cent grafting and average molecular weight of grafts. It was found that H₂SO₄ characteristically dissolves out ceric ion adsorbed into an aqueous solution and accelerates the formation of homopolymer.     

Lower Tropospheric Aerosol Measurements by MAX-DOAS During Severe Asian Dust Period

A recently developed aerosol retrieval algorithm based on O₄ slant column densities (SCDs) measured at a visible wavelength (476 nm) was utilized to derive aerosol information (e.g., aerosol optical depth (AOD) and vertical distributions of aerosol extinction coefficients (AECs)) in the lower troposphere during a severe Asian dust period. The MAX-DOAS measurements were carried out at Gwangju, Korea for nearly three months from February through May 2008. Comparison with AOD and surface PM₁₀, measured by collocated sunphotometer and beta gauge sampler, were made to validate the retrieved AODs and AECs in the atmospheric layer surface to 1 km height above ground. On the Asian dust days, temporal variations of the AODs retrieved from MAX-DOAS measurements show similar patterns, but with reduced magnitudes, to those measured by sunphotometer whereas similar AOD magnitude and temporal variation was observed between MAX-DOAS and sunphotometer measurements during the non-episodic days. Smaller correlation was observed between the surface PM₁₀ and AECs at 0.5 km during the Asian dust period compared to the correlation obtained for the non episodic days. This study demonstrates the ability of MAX-DOAS as a remote sensing technique for surface aerosol measurements under conditions of homogeneously distributed pollution in the planetary boundary layer. However, for the measurement of significantly enhanced aerosol loads with heterogeneous vertical distribution (e.g., Asian dust), measured AODs and AECs are underestimated at altitudes above 1 km due to decreased sensitivity of MAX-DOAS measurements at high altitudes.     

Mutational analysis of structure--activity relationships in human tumor necrosis factor-alpha

To determine the region of human tumor necrosis factor-alpha(TNF-), essential for cytotoxic activity against mouse L-M cells,single amino-acid-substituted TNF- mutant proteins (muteins)were produced in Escherichia coli by protein engineering techniques.An expression plasmid for TNF- was mutagenized by passage throughan E.coli mutD5 mutator strain and by oligonucleotide-directedmutagenesis. Approximately 100 single amino-acid-substitutedTNF- muteins were produced and assayed for cytotoxic activity.The cytotoxic activities of purified TNF- muteins, e.g. TNF-31T,-32Y, -82D, -85H, -115L, -141Y, -144K and -146E, were < 1%of that of parent TNF-. These results indicate that the integrityof at least four distinct regions of the TNF- molecule is requiredfor full biological activity. These regions are designated asfollows: region I, from position 30 to 32; region II, from position82 to 89; region III, from position 115 to 117; region FV, fromposition 141 to 146. In addition, TNF-141Y could not completelycompete with parent TNF- for binding to the receptor. This demonstratesthat region IV, and at least aspartk acid at position 141, mustbe involved in the TNF receptor binding site.     

二氧化碳地中隔离技术及其岩石力学问题

寻求经济又安全的强有力减排技术关系到日本政府能否履行在京都议定书中所作的承诺。二氧化碳是主要的温室气体，二氧化碳地中隔离是把从集中排放源分离得到的二氧化碳注入地下深处具有适当封闭条件的地层中隔离起来，即把二氧化碳归还原处——地球深部。介绍了二氧化碳地中隔离的概念及国际动态，并基于隔离容量、机理、安全性及成本分析，论述其可行性。     

Piezoelectric properties of langasite group based on the ionic size of cation

As langasite A₃BC₃D₂O₁₄ compounds group with piezoelectric properties has no phase transition up to the melting point of 1400–1500 °C, they have been applied for the combustion pressure sensor. As they also have a larger electromechanical coupling factor compared to quartz and nearly the same temperature stability as quartz, the surface acoustic wave (SAW) filters are expected based on the digital transformation of wider bandwidth and higher-bit rates. In the case of three-element compounds such as [R₃]_A[Ga]_B[Ga₃]_C[GaSi]_DO₁₄ (R=La, Pr and Nd), the piezoelectric constant increases with the ionic radius R. In the case of four-element compounds such as [A₃]_A[B]_B[Ga₃]_C[Si₂]_DO₁₄ (A=Ca or Sr, B=Ta or Nb), |d₁₁| and k₁₂ values as a function of A_L/B_L ratio showed a linear relationship completely. There are two effects for the substitutions of A- and B-site cations: the substitution of Sr for Ca brings expansion toward [100] and enlargement in |d₁₁| and k₁₂. On the other hand, as the substitution of Ta for Nb brings not much change, the properties are similar. In this study, five-element compounds such as La_3?xSr_xTa_yGa_5?x+ySi_1+x?2yO₁₄ (0≤x≤3, 0≤y≤1) solid solutions analysed by a single crystal X-ray diffraction are compared with the three- and four-element compounds on the coordinates of oxygen ions. As the coordinates positions are located on the extended line of coordinate positions on the three-element compounds as increasing ionic radius of R-ions in A-site, the piezoelectric properties |d₁₁| and k₁₂ are expected become large.     

Synthesis of Ti-based bulk quasicrystal by shock compression

We attempted to produce a Ti₄₅Zr₃₈Ni₁₇ bulk icosahedral (i) quasicrystal by a shock compression technique, in which a single-stage powder gun discharges a flyer plate that consolidates the target powders. The results were also compared with those by a conventional hot-pressing. The powder mixtures for the shock compression were blended by two kinds of methods; that is, gently mixing in a vial, and mechanically alloying by a planetary ball mill. A large bulk i-phase sample, with a Ti₂Ni crystal phase, was synthesized from mechanically alloyed powders after shock compression at a higher flyer velocity, although the conventional hot-pressing at 3 MPa synthesized only the Ti₂Ni phase. For the gently mixed powders, no reaction occured even after shock compression. High-pressure and high-temperature produced during shock compression, and milling process were key factors to obtain the i-phase. The Vickers hardness and the wetting contact angle with pure water under an atmospheric pressure for the bulk sample containing the i-phase were about 7 GPa and about 70°, respectively.     

Bi-Cu film deposition in aqueous solutions

The relatively uniform bismuth-copper film was electrodeposited between −15 and −20 mV in the sulfate electrolyte containing 4 mmol/L bismuth ion and 2 mmol/L copper ion. Only copper was electrodeposited at −5 mV. The dendritic bismuth-copper film was electrodeposited under −20 mV. The cathodic current became constant between −20 and −400 mV. Therefore, bismuth-copper electrodeposition changes from charge transfer controlling to diffusion controlling at −20 mV. On the other hand, the uniform bismuth-copper film was electrodeposited between −5 and −35 mV in the methanesulfonate electrolyte containing 4 mmol/L bismuth ion and 2 mmol/L copper ion. The dendritic bismuth-copper film was electrodeposited under −35 mV. The potential region for good electrodepositon in methanesulfonate electrolyte is wider than that in sulfate electrolyte. Therefore, it is easy to control electrodeposition conditions by using methanesulfonate electrolyte.