Search

Novel NASICON-type LiXIn0.5Z0.5(PO4)3 (X = Ti, Zr; Z = Nb, Ta) oxides were successfully synthesized by solid-state reaction, and resultant crystal structures (space group R-3c) and ionic conductivities were investigated based on a scheme of changed unit cell volume but an unchanged nominal carrier concentration (or constant Li+ amount). Relative to unsubstituted LiX2(PO4)3, the conductivities of all samples were improved by approximately an order of magnitude, with LiTiIn0.5Ta0.5(PO4)3 sample showing the highest value of 2.5×10-6 S cm-1 at room temperature. The improvement in ionic conductivity of Ti-containing samples is considered due to an increase in unit cell volume caused by the larger size of substituted ions (In3+, Nb5+, or Ta5+). Conversely, the improvement in ionic conductivity of Zr-containing samples may be attributed to an increase in lithium ion migration caused by a repulsion between the lithium ion and its surrounding cations (Zr4+, In3+, or Nb5+/Ta5+) in a smaller unit cell volume, thus forming a weakened Li-O bond.

A 61-year-old woman was referred to our hospital with refractory thrombocytopenia and splenomegaly. She was diagnosed with immune thrombocytopenia 3 years prior to admission and received steroid therapy. However, her platelet count started decreasing six months prior to admission. A diagnostic and therapeutic splenectomy was performed, which led to the diagnosis of histiocytic sarcoma. The patient’s platelet count recovered promptly after splenectomy, and she was in complete remission for over a year.

Flocculation has been recognized for hundreds of years as an important phenomenon in brewing and wastewater treatment. However, the underlying molecular mechanisms remain elusive. The lack of a distinct phenotype to differentiate between slow-growing mutants and floc-forming mutants prevents the isolation of floc-related gene by conventional mutant screening. To overcome this, we performed a two-step Escherichia coli mutant screen. The initial screen of E. coli for mutants conferring floc production during high salt treatment yielded a mutant containing point mutations in 61 genes. The following screen of the corresponding single-gene mutants identified two genes, mrcB, encoding a peptidoglycan-synthesizing enzyme and cpxA, encoding a histidine kinase of a two-component signal transduction system that contributed to salt tolerance and flocculation prevention. Both single mutants formed flocs during high salt shock, these flocs contained cytosolic proteins. ΔcpxA exhibited decreased growth with increasing floc production and addition of magnesium to ΔcpxA suppressed floc production effectively. In contrast, the growth of ΔmrcB was inconsistent under high salt conditions. In both strains, flocculation was accompanied by the release of membrane vesicles containing inner and outer membrane proteins. Of 25 histidine kinase mutants tested, ΔcpxA produced the highest amount of proteins in floc. Expression of cpxP was up-regulated by high salt in ΔcpxA, suggesting that high salinity and activation of CpxR might promote floc formation. The finding that ΔmrcB or ΔcpxA conferred floc production indicates that cell envelope stress triggered by unfavorable environmental conditions cause the initiation of flocculation in E. coli.