The Microbiome and Metabolome of the Gut of Children with Sepsis and Septic Shock.

BACKGROUND: There is limited understanding of alteration of gut microbiota and metabolome in children with sepsis/septic shock. METHODS: In this prospective observational study carried out in a pediatric intensive care unit of a tertiary care center from 2020 to 2022, patients aged <17 years with sepsis/septic shock and healthy children (HC) were enrolled. We characterized the gut bacterial compositions by metagenome sequencing and metabolomes by untargeted gas chromatography-mass spectrometry. The primary outcome was to compare the gut microbiota and metabolome of children with sepsis/septic shock with that of HC. The Firmicutes/Bacteroidetes (F/B) ratio was compared between children with sepsis/septic shock and HC. Key secondary outcomes were to evaluate association of factors associated with a low F/B ratio in children with sepsis/septic shock. RESULTS: A total of 40 children (63% boys) (15 children with sepsis and septic shock and 10 healthy children) with a median (IQR) age of 5.5 (1.5, 10) years were enrolled. In the fecal microbiota, the α-diversity index including Shannon and Simpson indices of the sepsis/septic shock groups was significantly lower than that of the HC. The samples lacked beneficial Bifidobacterium spp. and were dominated by Bacteroides, Enterobacteriaceae, and Enterococcaceae. There was reduction in short-chain fatty acids (SCFAs) in patients with sepsis/septic shock as compared to healthy children. A lower F/B ratio (≤1.57) of the gut microbiota discriminated well between children with sepsis/septic shock and HC. Factors associated with lower F/B ratio were male gender, clinical GI dysfunction, elevated inflammatory markers, and higher organ failure scores. CONCLUSION: There were significant alterations in the gut microbiota and metabolome in children with sepsis/septic shock as compared to healthy children. Larger study is needed to confirm these exploratory findings and develop potential therapeutic targets that will improve outcomes in children with sepsis/septic shock.

Novel lithium-containing honeycomb structures.

Rock-salt-based honeycomb structures containing Te(VI) and Sb(V) with innumerable prospects of properties and applications were realized in the two new series of mixed-metal oxides of lithium, Li(8)M(2)Te(2)O(12) (M(II) = Co, Ni, Cu, Zn) and Li(8)M(2)Sb(2)O(12) (M(III) = Cr, Fe, Al, Ga). The structures of Li(8)Co(2)Te(2)O(12) and Li(8)Cu(2)Te(2)O(12) were determined by single-crystal X-ray diffraction for the first time, and mixed-occupancy Li/M was identified.

Synthesis and structural investigation of a unique columnar phase in the Bi2O3­TeO2­V2O5 System.

A new columnar phase Bi(11.65)Te(1.35)V(5)O(34-δ) (δ ∼ 1.3) containing VO(4) tetrahedra has been identified for the first time in the Bi(2)O(3)-TeO(2)-V(2)O(5) system. The phase formation and the extent of substitution of Te(4+) for Bi(3+) ions in order to stabilize V(5+) in this composition have been confirmed by the single crystal analysis, combined with the powder X-ray diffraction of the solid state synthesized bulk crystalline samples. The oxide crystallizes in a monoclinic crystal system, space group P2/c, with unit cell parameters a = 11.4616(7) Å, b = 5.7131(3) Å, c = 23.5090(18) Å, ß = 101.071° (6) (Z = 2). The structure retains the basic features of the columnar oxides with the presence of [Bi(10.65)Te(1.35)O(14)](n)(9.35n+) columns along the (010) direction, surrounded by (VO(4)) tetrahedra placed in the planes parallel to (100) and (001), with an isolated bismuth atom in between the columns. The composition with a limited Te(4+) substitution, Bi(11.65)Te(1.35)V(5)O(34-δ) (δ ∼ 1.3), exists with a surprisingly high oxygen deficiency as compared to the stoichiometrically known columnar oxides such as Bi(13)Mo(4)VO(34), Bi(12)Te(1)Mo(3)V(2)O(34), and Bi(11)Te(2)Mo(2)V(3)O(34). The structure of this interesting member of the columnar family of oxides based on the single crystal X-ray diffraction and the Raman spectroscopic studies indicates the possibility of the distribution of the oxygen vacancies among the VO(4) tetrahedral units. Further confirmation for the formation of vanadium stabilized columnar structures has been provided by the successful preparation of Bi(11.65)Te(1.35)V(4)CrO(34-δ) (δ ∼ 0.83) and Bi(11.65)Te(1.35)V(4)WO(34-δ) (δ ∼ 0.83) phases. Preliminary investigation of the photocatalytic efficiencies of the oxides Bi(11.65)Te(1.35)V(5)O(34-δ), Bi(11.65)Te(1.35)V(4)CrO(34-δ), and Bi(11.65)Te(1.35)V(4)WO(34-δ) revealed moderate photocatalytic activities for the decomposition of the dyes such as Rhodamine B under UV-vis light irradiation.

Facile room temperature ion-exchange synthesis of Sn(2+) incorporated pyrochlore-type oxides and their photocatalytic activities.

Ion-exchange reactions of aqueous SnCl(2).2H(2)O solutions with oxides such as H(2)Sb(2)O(6).3.0H(2)O, KSbWO(6), and KTaWO(6).1.0H(2)O resulted in novel Sn(2+) incorporated pyrochlore-type oxides under ambient conditions. Characterization of the Sn(2+) exchanged products by powder X-ray diffraction, EDAX, thermogravimetric analysis, and chemical analysis yielded nominal compositions of Sn(0.92)Sb(2)O(6).2.0H(2)O, K(0.59)Sn(0.20)SbWO(6).1.0H(2)O, and K(0.58)Sn(0.29)TaWO(6).1.0H(2)O. Diffuse reflectance spectra of the oxides incorporated with Sn(2+) ions clearly exhibited red shifts from their respective parent oxides. The observed reduction in the band gaps to an extent of 0.9-1.6 eV was consistent with the Sn(2+) ion-exchange, and indicated the upward shifting of the valence band resulting from the contribution of 5s band of Sn(2+) to the O 2p band. Photocatalytic activities of the synthesized pyrochlore oxides were consistent with their electronic properties and decomposed methyl orange (MO) solutions under visible light. The pseudo first order rate constants of the oxides Sn(0.92)Sb(2)O(6).2.0H(2)O and K(0.59)Sn(0.20)SbWO(6).1.0H(2)O for the decomposition of MO solutions were found to be 1.34 h(-1) and 0.217 h(-1), respectively, and almost a negligible MO decomposition was observed for K(0.58)Sn(0.29)TaWO(6).1.0H(2)O. The photocatalytic efficiencies of the oxides were found to be proportional to the rate of formation of .OH radicals, which was found to vary in the order, Sn(0.92)Sb(2)O(6).2.0H(2)O > K(0.59)Sn(0.20)SbWO(6).1.0H(2)O > K(0.58)Sn(0.29)TaWO(6).1.0H(2)O as determined by the photoluminescence spectra using terephthalic acid.