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T-cell immune responses modulated by T-cell immunoglobulin and mucin domain-containing molecule 3 (Tim-3) during Mycobacterium tuberculosis (Mtb) infection in humans remain poorly understood. Here, we found that active TB patients exhibited increases in numbers of Tim-3-expressing CD4+ and CD8+ T cells, which preferentially displayed polarized effector memory phenotypes. Consistent with effector phenotypes, Tim-3+ CD4+ and Tim-3+ CD8+ T-cell subsets showed greater effector functions for producing Th1/Th22 cytokines and CTL effector molecules than Tim-3- counterparts, and Tim-3- expressing T cells more apparently limited intracellular Mtb replication in macrophages. The increased effector functions for Tim-3-expressing T cells consisted with cellular activation signaling as Tim-3+ CD4+ and Tim-3+ CD8+ T-cell subsets expressed much higher levels of phosphorylated signaling molecules p38, stat3, stat5, and Erk1/2 than Tim-3- controls. Mechanistic experiments showed that siRNA silencing of Tim-3 or soluble Tim-3 treatment interfering with membrane Tim-3-ligand interaction reduced de novo production of IFN-γ and TNF-α by Tim-3-expressing T cells. Furthermore, stimulation of Tim-3 signaling pathways by antibody cross-linking of membrane Tim-3 augmented effector function of IFN-γ production by CD4+ and CD8+ T cells, suggesting that Tim-3 signaling helped to drive stronger effector functions in active TB patients. This study therefore uncovered a previously unknown mechanism for T-cell immune responses regulated by Tim-3, and findings may have implications for potential immune intervention in TB. [ABSTRACT FROM AUTHOR]

The electrochemical characteristics of vitamin K3 (denoted VK3) incorporated in acid-treated multiwalled carbon nanotubes (MWNTs)-chitosan (CHIT) hybrid films in phosphate buffer solutions were determined and the electrocatalytic oxidation of dopamine (DA) was investigated. It was shown that the adsorbility of VK3 on the surface of a glassy carbon electrode was greatly enhanced by CHIT and MWNTs. Cyclic voltammetric measurements revealed that the redox peak currents of VK3 increased dramatically with the addition of MWNTs. The apparent charge-transfer rate constant ks and transfer coefficient a for electron transfer between the electrode surface and immobilized VK3 in MWNTs-CHIT hybrid films and in MWNT films were calculated as 21.4 s-1, 0.49 and 3.2 s-1, 0.47, respectively. The electrocatalytic oxidation of DA evaluated by cyclic voltammetric measurements indicates that VK3-MWNTs-CHIT hybrid film modified electrodes have good electrocatalytic property to DA. The differential pulse voltammograms were used to detect the DA concentration. A linear relationship between steady-state current and DA concentration was obtained over the range of 2-100 μmol/L with a detection limit of 0.18 μmol/L. [ABSTRACT FROM AUTHOR]

A series of novel fluorotitanophosphates with a general formula (NH4)xK4 - x[Ti2PO4F9] (x = 0, 0.70, 1.00, 1.25, named as 1, 2, 3, and 4 respectively) have been synthesized under hydrothermal conditions. Their structures were determined by X-ray single-crystal diffraction technique, which show that all of the phases in this series contain an dental anionic fluorotitanophosphate chain, consisting of alternating linkage of PO4 tetrahedra and TiO2F4 octahedra. The fluorotitanophosphate chain is unique, which is different from the first titanophosphate chain found in [Ti3P6O27]·5[NH3CH2-CH2NH3]·2H3O. Another interesting observation of this series is that, by partial substitution of potassium by ammonium, the structure converts to a more-symmetric version, while maintaining all of the topological feature. [ABSTRACT FROM AUTHOR]

A nonmetal pentaborate C2H10N2B5O8(OH) (I) was synthesized by a solvothermal method at 150 °C and characterized by elemental analysis, IR, thermogravimetric analysis, and X-ray diffraction. The structure of Iwas determined by a single-crystal technique. It crystallizes in the monoclinic system with space group Cc, a6.7085 (13) Å, b11.437(2) Å, c12.530(3) Å, and 95.41(3)°. Powder second-harmonic generation (SHG) efficiency measurements with Nd:YAG laser (1064 nm) radiation show that C2H10N2B5O8(OH) has a SHG efficiency approximately 1.2 times of that of potassium dihydrogen phosphate (KDP). [ABSTRACT FROM AUTHOR]

Dielectric constants of complex perovskite oxide (Ba1 - xLax) (Ti1 - xCrx) O3 (BLTC) ceramics with 0.4 ≤ x ≤ 0.7 are measured, and a remarkable colossal dielectric relaxation which is quite similar to that of CaCu3Ti4O12 (CCTO) is found in higher temperature region above the ferroelectric phase transition. This kind of dielectric relaxation is successfully explained by an equivalent circuit model of a series of two R-C parallel circuits with temperature-dependent electrical conductivity and temperature-independent intrinsic dielectric constant. It is also found that the dc bias effect on the sample can distinguish this hetero-structure model and the proper Debye relaxation model of a homogeneous phase. [ABSTRACT FROM AUTHOR]

Large single crystals of oxygen-deficient Sr6Co5O15-δ compounds, i.e., Sr6Co5O14.70 and Sr6Co4.9Ni0.1O14.36, were obtained by using K2CO3 flux in the presence of additives of transition metal oxides. The single-crystal structure determination shows that the structures of Sr6Co5O14.70 and Sr6Co4.9Ni0.1O14.36 crystallize in the space group R3 and can be described as one-dimensional face-sharing CoO3 polyhedral chains and Sr cation chains. Unlike the other known 2H-perovskite-related oxides in which the polyhedral chains consist of octahedra (Oh) and trigonal prism (TP), the structure of Sr6Co5O14.70 and Sr6Co4.9Ni0.1O14.36 contain Oh and intermediate polyhedra (IP) and can be attributed to a general structure formula A6A′2B3O15-δ, which is closely related to the known A6A′B4O15 phases by shifting of a B atom and the O3 triangle along the c axis. Further study on O3 reveals that this oxygen position splits into two independent positions, corresponding to polyhedral geometry of P and TP, respectively. Therefore, the polyhedral chain in the structure should be more precisely described as a random composite of the 4Oh + TP and 3Oh + 2IP. This model is used to interpret the magnetic properties, although not quantitatively. The 4-D structure analysis was also conducted for both Sr6Co5O14.70 and Sr6Co4.9Ni0.1O14.36 with a commensurate modulated structure in a 4-D superspace group, R3m(00γ)0s, γ = p/k = 3/5. By considering the same 4-D superspace group R3m(00γ)0s but different t-phases, one can understand the structure relationship between Sr6Co5O14.70 and Sr6Rh5O15. [ABSTRACT FROM AUTHOR]

Two new polymorphs of BiB3O6 were identified at low temperatures using boric acid as a flux. Unlike α-BiB3O6, which crystallizes in a noncentrosymmetric space group and, thus, shows exceptional nonlinear optical (NLO) properties, β-BiB3O6 (I) and γ-BiB3O6 (II) crystallize in the centrosymmetric space group P21/n with the following lattice parameters: a = 14.1664(1), b = 6.7514(1), c = 4.4290(1) Å, β = 102.125(1)° for I; and a = 8.4992(1), b = 11.7093(1), c = 4.2596(1) Å, β = 121.141(1)° for II. However, from the structural point of view, the three polymorphs of BiB3O6 are closely related. The structure of β-BiB3O6 (I) contains a 2-dimensional borate layer, which could be considered to be an intralayered additive product of α-BiB3O6. On the other hand, the 3-dimensional borate framework in γ-BiB3O6 (II) could be considered to be an interlayered additive product of β-BiB3O6 (I). According to the synthesis experiments and calculated density, it is proposed that compounds I and II should be the low-temperature (high-pressure) polymorphs of BiB3O6. [ABSTRACT FROM AUTHOR]

Two solid solutions, La4Cu3-xZnxMoO12 (0.05 ⩽ × ⩽ 0.20, SS1) and La4Cu3-xZnxMoO12 (0.30 ⩽ × ⩽ 2.40, SS2), were synthesized at ambient pressure and at temperatures from 1025 to 1200 °C by traditional solid-state reactions. Their structures were determined from X-ray powder diffraction with the help of electron and neutron diffraction. The atomic arrangements of SS1 and SS2 are similar, but their space groups are different, Pmnm for SS1 and P-1 for SS2, respectively. The copper, zinc, and molybdenum are coordinated by oxygen in corner-sharing trigonal bipyramids that are sandwiched between layers of lanthanum cations. In the transition metal cations layer of SS2, the copper and zinc cations order into a Kagomé-like lattice of triangular clusters. The magnetism has been measured from 2 to 300 K and is highly influenced by the geometric arrangement of the CuII and ZnII cations. The number of free electrons per three Cu atoms is close to one for all samples in SS1 and SS2 indicating that the system can be well expressed by independent CuII3 clusters. Spontaneous magnetization was observed in the system. [ABSTRACT FROM AUTHOR]

In order to develop useful lead-free ferroelectric materials based on BaTiO 3 , Ba 1 - x La x Ti 1 - x Cr x O 3 ceramics were synthesized and their dielectric properties were studied. The crystal structure of Ba 1 - x La x Ti 1 - x Cr x O 3 changes in the sequence of tetragonal, cubic, rhombohedral and orthorhombic as x increases. Curie temperature T C decreases largely as x increases. The samples except for x = 0.003 show broad peak of high dielectric constant with small dielectric loss. The frequency dispersion like in relaxors is observed below room temperature with x = 0.08. [ABSTRACT FROM AUTHOR]

One oxyfluorotitanophosphate cluster compound, K16[Ti10P4O16F44], has been synthesized and structurally characterized. As far as we know, it is the first cluster compound for titanophosphate. [ABSTRACT FROM AUTHOR]

Presents a letter to the editor about a simple method of polyacrylamide gel to prepare cordierite powders.

Two compounds (Tb1-xMny)MnO3-δ (W1, x = 0.089, y = 0.063; W2, x = 0.122, y = 0.102) have been synthesized by solid-state method and characterized using neutron diffraction and magnetic measurements. They crystallize in space group Prima at room temperature and Pna21 at low temperature. W1 shows a sinusoidal antiferromagnetic order, and W2 shows both sinusoidal and canted commensurate antiferromagnetic orders. The magnetic moments of the commensurate antiferromagnetic order for W2 are antiferromagnetically coupled along the a- and c-axes, and ferromagnetically coupled along the b-axis in the Pna21 setting. Strong ferromagnetic response is induced by doping more Mn into the Tb site of (Tb1-xMny)MnO3-δ [ABSTRACT FROM AUTHOR]

Polycrystalline and monocrystalline α-BiFeO3 crystals have been synthesized by solid state reaction and flux growth method, respectively. X-ray, neutron, and electron diffraction techniques are used to study the crystallographic and magnetic structure of α-BiFeO3 The present data show that α-BiFeO3 crystallizes in space group PI with a - 0.563 17(1) wn, b = 0.563 84(1) nm, c = 0.563 70(1) nm, α = 59.33(1)°, β = 59.35(1)°, γ = 59.38(1)°, and the magnetic structure of α-BiFeO3 can be described by space group PI with magnetic modulation vector in reciprocal space q = 0.0045a* -- 0.004Sb*, winch is the magnetic structure model proposed by I. Sosnowska¹ applied to the new PI crystal symmetry of α-BiFeO3. [ABSTRACT FROM AUTHOR]

This study assessed the in vitro antibacterial activity of minocycline-aminoglycoside combination against Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae. Seventy non-duplicate clinical isolates of KPC-producing K. pneumoniae were collected from patients with bloodstream infections. The synergistic activity of minocycline-aminoglycoside combination was studied by the checkerboard method and time-kill assays in strains with different susceptibilities, and the mutant prevention concentration (MPC) and mutant selection window (MSW) of drugs alone and in combination were determined. The checkerboard method found this combination displayed synergistic and partial synergistic activity against aminoglycoside-susceptible isolates, but indifferent activity against aminoglycoside-resistant isolates. Time-kill assays further demonstrated strong synergistic and bactericidal effect of this combination existed against isolates which were susceptible to both drugs. But for resistant isolates, the time-kill assays showed no synergy. The MPCs of minocycline or aminoglycosides were 8- to 32-fold higher than the MICs, suggesting the MSWs of these drugs were quite wide. For the antibiotic combinations, the addition of 1×MIC concentration of amikacin or gentamicin could reduce the MPCs of minocycline by 4- to 16-fold. Generally, no mutants recovered in the plates containing 1×MIC concentration of minocycline and 2×MIC concentration of amikacin or gentamicin. In summary, these results suggest that minocycline-aminoglycoside combination can be an alternative for infections caused by KPC-producing K. pneumoniae because this combination displays strong synergistic and bactericidal activity in susceptible isolates, and can effectively prevent the emergence of resistant mutants. Further in vitro pharmacokinetic/pharmacodynamic studies and clinical trials should be performed to fully evaluate the efficacy of this drug combination.