Unconventional charge density wave in the organic conductor alpha-(BEDT-TTF)_2KHg(SCN)_4

The low temperature phase (LTP) of alpha-(BEDT-TTF)_2KHg(SCN)_4 salt is known for its surprising angular dependent magnetoresistance (ADMR), which has been studied intensively in the last decade. However, the nature of the LTP has not been understood until now. Here we analyse theoretically ADMR in unconventional (or nodal) charge density wave (UCDW). In magnetic field the quasiparticle spectrum in UCDW is quantized, which gives rise to spectacular ADMR. The present model accounts for many striking features of ADMR data in alpha-(BEDT-TTF)_2KHg(SCN)_4.Comment: 5 pages, 6 figure

Likvefakcija mekog mrkog uglja Kosovskog Basena

The behaviour of Kosovo Basin (Yugoslavia) soft brown coal was studied during a direct liquefaction process by catalytic hydrogenation. A stream of hydrogen was passed through a tetralin dispersion of the pulverized coal in the presence of commercial extruded hydrogenating-desulphurizing cobalt-molybdenum/alumina catalyst. The experiments were carried out in the temperature range between 365 and 440°C at 13.5 and 15.0 MPa, the reactants being kept at selected stationary working conditions for 1-8 hrs. The yields of liquid products soluble in n-heptane (light oils), asphaltenes (n-heptane insoluble liquid products) and the solid coal residue served as a basis for the estimation of coal reactivity and for the calculation of total coal conversion. The liquid product yields varied substantially depending on the reaction temperature and the residence time. The total conversion under most of the applied reaction conditions was found to be around 80%, the highest (-86%) being observed with the longest, 8 h residence time. Various types of grains of modified coal and newly formed types of coal grains, as well as mineral matter were identified by micropetrographic analysis, indicating the release of gases in the initial stages of hydrogenation and the formation of semi-coke and coke by the polymerization of liquid products in the later reaction stages

Unconventional spin density wave in (TMTSF)2PF6 below T* ~ 4K

The presence of subphases in spin-density wave (SDW) phase of (TMTSF)2PF6 below T* ~ 4K has been suggested by several experiments but the nature of the new phase is still controversial. We have investigated the temperature dependence of the angular dependence of the magnetoresistance in the SDW phase which shows different features for temperatures above and below T*. For T > 4K the magnetoresistance can be understood in terms of the Landau quantization of the quasiparticle spectrum in a magnetic field, where the imperfect nesting plays the crucial role. We propose that below T* ~ 4K the new unconventional SDW (USDW) appears modifying dramatically the quasiparticle spectrum. Unlike conventional SDW the order parameter of USDW depends on the quasiparticle momentum. The present model describes many features of the angular dependence of magnetoresistance reasonably well. Therefore, we may conclude that the subphase in (TMTSF)2PF6 below T* ~ 4K is described as SDW plus USDW.Comment: 7 pages, 9 figures, RevTeX4; misprint corrected, references updated, a few sentences adde

Quasiparticle transport in the vortex state of YBa_2Cu_3O_6.9

The effect of vortices on quasiparticle transport in cuprate superconductors was investigated by measuring the low temperature thermal conductivity of YBa_2Cu_3O_6.9 in magnetic fields up to 8 T. The residual linear term (as T \to 0) is found to increase with field, directly reflecting the occupation of extended quasiparticle states. A study for different Zn impurity concentrations reveals a good agreement with recent calculations for a d-wave superconductor, thereby shedding light on the nature of scattering by both impurities and vortices. It also provides a quantitative measure of the gap near the nodes.Comment: 4 pages, 2 included eps figures, significant new analysis wrt other experiments, to appear in Phys Rev Lett 29 March 199

Proinflammatory Cytokine IL-6 and JAK-STAT Signaling Pathway in Myeloproliferative Neoplasms

The recent JAK1/2 inhibitor trial in myeloproliferative neoplasms (MPNs) showed that reducing inflammation can be more beneficial than targeting gene mutants. We evaluated the proinflammatory IL-6 cytokine and JAK-STAT signaling pathway related genes in circulating CD34(+) cells of MPNs. Regarding laboratory data, leukocytosis has been observed in polycythemia vera (PV) and JAK2V617F mutation positive versus negative primary myelofibrosis (PMF) patients. Moreover, thrombocytosis was reduced by JAK2V617F allele burden in essential thrombocythemia (ET) and PMF. 261 significantly changed genes have been detected in PV, 82 in ET, and 94 genes in PMF. The following JAK-STAT signaling pathway related genes had augmented expression in CD34(+) cells of MPNs: CCND3 and IL23A regardless of JAK2V617F allele burden; CSF3R, IL6ST, and STAT1/2 in ET and PV with JAK2V617F mutation; and AKT2, IFNGR2, PIM1, PTPN11, and STAT3 only in PV. STAT5A gene expression was generally reduced in MPNs. IL-6 cytokine levels were increased in plasma, as well as IL-6 protein levels in bone marrow stroma of MPNs, dependent on JAK2V617F mutation presence in ET and PMF patients. Therefore, the JAK2V617F mutant allele burden participated in inflammation biomarkers induction and related signaling pathways activation in MPNs

Crystal structure of dicholoro-(3,5-dimethyl-1H-pyrazole-1-carboxamidine-N,N )copper(II), Cu(C6H10N4)Cl-2

C6H10Cl2CuN4, monoclinic, P2(1)/n (no. 14), a = 7.316(2) angstrom b = 16.002(2) angstrom, c = 9.202(6) angstrom, beta = 113.15 (2)degrees, V = 990.6 angstrom(3), Z = 4, R-gt(F) = 0.054, wR(ref)(F-2) = 0.125, T = 293 K

Arginine at positions 13 or 70-71 in pocket 4 of HLA-DRB1 alleles is associated with susceptibility to tuberculoid leprosy

Evaluation of human histocompatibility leukocyte antigen (HLA) class II genes in 54 cases of tuberculoid leprosy (TL) and 44 controls has shown a positive association with HLA-DRB1 alleles that contain Arg13 or Arg70-Arg71. Among TL patients, 87% carry specific alleles of DRB1 Arg13 or Arg70-Arg71 as compared to 43% among controls (p = 5 x 10(-6)) conferring a relative risk of 8.8. Thus, susceptibility to TL involves three critical amino acid positions of the beta chain, the side chains of which, when modeled on the DR1 crystal structure, line a pocket (pocket 4) accommodating the side chain of a bound peptide. This study suggests that disease susceptibility may be determined by the independent contribution of polymorphic residues participating in the formation of a functional arrangement (i.e., pocket) within the binding cleft of an HLA molecule

Heterolytic Scission of Hydrogen Within a Crystalline Frustrated Lewis Pair

We report the heterolysis of molecular hydrogen under ambient conditions by the crystalline frustrated Lewis pair (FLP) 1-{2-[bis (pentafluorophenyOboryl] phenyl -2, 2,6,6-tetrame-thylpiperidine (KCAT). The gas-solid reaction provides an approach to prepare the solvent-free, polycrystalline ion pair KCATH2 through a single crystal to single crystal transformation. The crystal lattice of KCATH2 increases in size relative to the parent KCAT by approximately 2%. Microscopy was used to follow the transformation of the highly colored red/orange KCAT to the colorless KCATH2 over a period of 2 h at 300 K under a flow of H-2 gas. There is no evidence of crystal decrepitation during hydrogen uptake. Inelastic neutron scattering employed over a temperature range from 4-200 K did not provide evidence for the formation of polarized H-2 in a precursor complex within the crystal at low temperatures and high pressures. However, at 300 K, the INS spectrum of KCAT transformed to the INS spectrum of KCATH2. Calculations suggest that the driving force is more favorable in the solid state compared to the solution or gas phase, but the addition of H-2 into the KCAT crystal is unfavorable. Ab Initio methods were used to calculate the INS spectra of KCAT, KCATH2, and a possible precursor complex of H-2 in the pocket between the B and N of crystalline KCAT. Ex-situ NMR showed that the transformation from KCAT to KCATH2 is quantitative and our results suggest that the hydrogen heterolysis process occurs via H-2 diffusion into the FLP crystal with a rate-limiting movement of H-2 from inactive positions to reactive sites.Peer reviewe

Likvefakcija mekog mrkog uglja kosovskog basena

The behavior of Kosovo Basin (Yugoslavia) soft brown coal was studied during a direct liquefaction process by catalytic hydrogenation. A stream of hydrogen was passed through a tetralin dispersion of the pulverized coal in the presence of commercial extruded hydrogenating-desulphurizing cobalt-moly­bdenum/alumina catalyst. The experiments were carried out in the temperature range between 365 and 440°C at 13.5 and 15.0 MPa, the reactants being kept at selected stationary working conditions for 1-8 hrs. The yields of liquid products soluble in n-heptane (light oils), asphaltenes (n-heptane insoluble liquid products) and the solid coal residue served as a basis for the estimation of coal reactivity and for the calculation of total coal conversion. The liquid product yields varied substantially depending on the reaction temperature and the residence time. The total conversion under most of the applied reaction conditions was found to be around 80%, the highest (~86%) being observed with the longest, 8 h residence time. Various types of grains of modified coal and newly formed types of coal grains, as well as mineral matter were identified by micropetrographic analysis, indicating the release of gases in the initial stages of hydrogenation and the formation of semi-coke and coke by the polymerization of liquid products in the later reaction stages.Ispitivano je ponašanje mekog mrkog uglja Kosovskog basena (Jugoslavija) pri direktnoj likvefakciji. Katalitička hidrogenizacija izvođena je u protočnom šaržnom reaktoru propuštanjem vodonika kroz suspenziju tetralina i usitnjenog uglja, u prisustvu komercijalnog presulfidiziranog CO-MO/AI2O3 katalizatora. Eksperimenti su izvođeni na temperaturi 365 i 440°C, pritisku 13,5 i 15,0 MPa, u trajanju 1-8 sati. Reaktivnost uglja je procenjivana i ukupna totalna konverzija izračunavana je na osnovu prinosa tečnih proizvoda rastvornih u n-heptanu (laka ulja), asfaltena (proizvodi nerastvorni u n-heptanu) i čvrstog ostatka. Konverzija uglja pri navedenim uslovima iznosila je oko 80 %, a najveća je bila (~86 %) pri najdužem reakcionom vremenu. Mikropetrografskom analizom identifikovane su različite vrste zrna modifikovanog uglja kao i novo stvoreni tipovi zrna uglja kao i mineralnog materijala. Dobijeni rezultati ukazuju da se gasovi oslobađaju u početnim fazama hidrogenizacije, a da polimerizacijom tečnih proizvoda polu-koks i koks postaju u kasnijim fazama hidrogenizacije