Longitudinal Spin Fluctuations Driving Field-Reinforced Superconductivity in UTe_{2}.

Our measurements of ^{125}Te NMR relaxations reveal an enhancement of electronic spin fluctuations above µ_{0}H^{*}∼15 T, leading to their divergence in the vicinity of the metamagnetic transition at µ_{0}H_{m}≈35 T, below which field-reinforced superconductivity appears when a magnetic field (H) is applied along the crystallographic b axis. The NMR data evidence that these fluctuations are dominantly longitudinal, providing a key to understanding the peculiar superconducting phase diagram in H∥b, where such fluctuations enhance the pairing interactions.

Superconducting spin smecticity evidencing the Fulde-Ferrell-Larkin-Ovchinnikov state in Sr2RuO4.

Translational symmetry breaking is antagonistic to static fluidity but can be realized in superconductors, which host a quantum-mechanical coherent fluid formed by electron pairs. A peculiar example of such a state is the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state, induced by a time-reversal symmetry-breaking magnetic field applied to spin-singlet superconductors. This state is intrinsically accompanied by the superconducting spin smecticity, spin density-modulated fluidity with spontaneous translational-symmetry breaking. Detection of such spin smecticity provides unambiguous evidence for the FFLO state, but its observation has been challenging. Here, we report the characteristic "double-horn" nuclear magnetic resonance spectrum in the layered superconductor Sr2RuO4 near its upper critical field, indicating the spatial sinusoidal modulation of spin density that is consistent with superconducting spin smecticity. Our work reveals that Sr2RuO4 provides a versatile platform for studying FFLO physics.

Charge-neutral fermions and magnetic field-driven instability in insulating YbIr3Si7.

Kondo lattice materials, where localized magnetic moments couple to itinerant electrons, provide a very rich backdrop for strong electron correlations. They are known to realize many exotic phenomena, with a dramatic example being recent observations of quantum oscillations and metallic thermal conduction in insulators, implying the emergence of enigmatic charge-neutral fermions. Here, we show that thermal conductivity and specific heat measurements in insulating YbIr3Si7 reveal emergent neutral excitations, whose properties are sensitively changed by a field-driven transition between two antiferromagnetic phases. In the low-field phase, a significant violation of the Wiedemann-Franz law demonstrates that YbIr3Si7 is a charge insulator but a thermal metal. In the high-field phase, thermal conductivity exhibits a sharp drop below 300 mK, indicating a transition from a thermal metal into an insulator/semimetal driven by the magnetic transition. These results suggest that spin degrees of freedom directly couple to the neutral fermions, whose emergent Fermi surface undergoes a field-driven instability at low temperatures.

Asymmetric dimerization of aniline-ruthenium-dioxolene complex driven by stepwise PCET.

The base-assisted oxidation of an aniline-Ru-quinone complex produced an anilinyl radical-Ru-semiquinone. Furthermore, base-assisted oxidation of the radical complex resulted in selective C-N bond formation through an intermolecular coupling between nitrogen and carbon atoms at the para-position of the anilinyl ligand.

Freeze-drying synthesis of an amorphous Zn(2+) complex and its transformation to a 2-D coordination framework in the solid state.

An amorphous and metastable precursor for a Zn two-dimensional coordination framework was synthesised via freeze drying. The precursor comprises randomly packed discrete clusters of a Zn complex. The amorphous-to-crystalline framework transformation, which was triggered by the gentle application of heat or pressure, was accompanied by a change in the coordination geometry of the Zn(2+) ions from tetrahedral to octahedral symmetry.

Water stable triazolyl phosphonate MOFs: steep water uptake and facile regeneration.

The new microporous cobalt triazolyl phosphonate MOF3α [Co4L3(µ3-OH)(H2O)3](SO4)0.5·xH2O (L(2-) = 4-(4H-1,2,4-triazol-4-yl)-phenyl phosphonate) exhibits exciting features including high water stability, reversible hydration-dehydration, steep water uptake in repeated cycles at low water vapor pressures and reactivation at room temperature under mild evacuation.

Glass formation via structural fragmentation of a 2D coordination network.

The structure of a glass obtained by the melt quenching of a two-dimensional (2D) coordination network was examined. X-ray analyses disclosed a 2D-to-0D structural transformation before and after glass formation. The mechanism is unique to coordination compounds, as it is characterized by labile and flexible coordination bonds.

Synthesis of magnesium ZIF-8 from Mg(BH4)2.

Porous Mg(2-methyl imidazolate)2 (Mg-ZIF-8) was synthesised from Mg(BH4)2 as a precursor under an Ar atmosphere. It possesses an uncommon tetrahedral Mg(2+)-N coordination geometry that is stabilised by the formation of a framework, and it exhibits a Brunauer-Emmett-Teller surface area greater than 1800 m(2) g(-1).

Terahertz phase contrast imaging of sorption kinetics in porous coordination polymer nanocrystals using differential optical resonator.

The enhancement of light-matter coupling when light is confined to wavelength scale volumes is useful both for studying small sample volumes and increasing the overall sensing ability. At these length scales, nonradiative interactions are of key interest to which near-field optical techniques may reveal new phenomena facilitating next-generation material functionalities and applications. Efforts to develop novel chemical or biological sensors using metamaterials have yielded innovative ideas in the optical and terahertz frequency range whereby the spatially integrated response over a resonator structure is monitored via the re-radiated or leaked light. But although terahertz waves generally exhibit distinctive response in chemical molecules or biological tissue, there is little absorption for subwavelength size sample and therefore poor image contrast. Here, we introduce a method that spatially resolves the differential near-field phase response of the entire resonator as a spectral fingerprint. By simultaneously probing two metallic ring resonators, where one loaded with the sample of interest, the differential phase response is able to resolve the presence of guest molecules (e.g. methanol) as they are adsorbed or released within the pores of a prototypical porous coordination polymer.

Ferromagnetic quantum critical point in heavy-fermion iron oxypnictide Ce(Ru(1-x)Fe(x))PO.

We have performed (31)P-NMR measurements on Ce(Ru(1-x)Fe(x))PO in order to investigate ferromagnetic (FM) quantum criticality, since a heavy-fermion (HF) ferromagnet CeRuPO with a two-dimensional structure turns into a HF paramagnet by an isovalent Fe substitution for Ru. We found that Ce(Ru(0.15)Fe(0.85))PO shows critical fluctuations down to ~0.3 K, as well as the continuous suppression of Curie temperature and the ordered moments by the Fe substitution. These experimental results suggest the presence of a FM quantum critical point (QCP) at x~0.86, which is a rare example among itinerant ferromagnets. In addition, we point out that the critical behaviors in Ce(Ru(0.15)Fe(0.85))PO share a similarity with those in YbRh(2)Si(2), where the local criticality of f electrons has been discussed. We reveal that Ce(Ru(1-x)Fe(x))PO is a new system to study FM quantum criticality in HF compounds.

MOF-on-MOF heteroepitaxy: perfectly oriented [Zn2(ndc)2(dabco)]n grown on [Cu2(ndc)2(dabco)]n thin films.

We report the successful heteroepitaxial growth of perfectly oriented hybrid MOF thin films. By employing step-by-step liquid-phase epitaxy (LPE), [Zn(2)(ndc)(2)(dabco)](n) was grown on [Cu(2)(ndc)(2)(dabco)](n), thus demonstrating that the MOF-on-MOF deposition scheme developed for powdered microcrystalline MOF materials can also be applied in connection with LPE for MOF thin films or multilayers. The deposition was monitored by surface plasmon resonance (SPR) spectroscopy, the resulting MOF heterostructures were characterized using IR spectroscopy and different types of X-ray diffraction (XRD)-based techniques. The results suggest that the LPE method is a promising way to fabricate and grow MOF heterostructures, and also demonstrates the potential of [Cu(2)(ndc)(2)(dabco)](n) MOF thin films as substrates for the LPE-based growth of different MOFs on top.

Metamagnetic behavior and Kondo breakdown in heavy-fermion CeFePO.

We report that nonmagnetic heavy-fermion (HF) iron oxypnictide CeFePO with two-dimensional XY-type anisotropy shows a metamagnetic behavior at the metamagnetic field H(M)≃4 T perpendicular to the c axis and that a critical behavior is observed around H(M). Although the magnetic character is entirely different from that in other Ce-based HF metamagnets, H(M) in these metamagnets is linearly proportional to the inverse of the effective mass, or to the temperature where the susceptibility shows a peak. This finding suggests that H(M) is a magnetic field breaking the local Kondo singlet, and the critical behavior around H(M) is driven by the Kondo breakdown accompanied by the Fermi-surface instability.

Unconventional superconductivity and antiferromagnetic quantum critical behavior in the isovalent-doped BaFe2(As1-xPx)2.

Spin dynamics evolution of BaFe2(As(1-x)Px){2} was probed as a function of P concentration via 31P NMR. Our NMR study reveals that two-dimensional antiferromagnetic (AF) fluctuations are notably enhanced with little change in static susceptibility on approaching the AF phase from the superconducting dome. Moreover, the magnetically ordered temperature θ deduced from the relaxation rate vanishes at optimal doping. These results provide clear-cut evidence for a quantum-critical point, suggesting that the AF fluctuations associated with the quantum-critical point play a central role in the high-T(c) superconductivity.

Effects of intracerebroventricular administration of neuromedin U or neuromedin S in steers.

Although neuromedin U (NMU) and neuromedin S (NMS) are reported to modulate stress responses mainly through corticotropin-releasing hormone system in rodents, the in vivo effects of centrally administered NMU or NMS on stress regulation have not been fully elucidated in cattle. We examined adrenocorticotropic hormone levels, body temperature, and behavioral responses to intracerebroventricularly (ICV) administered rat NMU or rat NMS in steers. ICV NMU and NMS (0.2, 2, and 20 nmol/200 microl) evoked a dose-related increase in plasma cortisol concentrations (CORT). There was a significant time-treatment interaction for the time course of CORT (p<0.001). ICV NMU evoked a dose-related increase in rectal temperature (RT). There was a significant time-treatment interaction for the change in RT from pre-injection value (p<0.05). There was a significant difference among treatments in the percentage of time spent lying (Friedman's test, chi(2)=15.6, p<0.01) and in the total number of head shaking (Friedman's test, chi(2)=14.49, p<0.01). A high dose of NMS tended to shorten the duration of lying and increase the number of head shaking. These findings indicate that both central NMU and NMS might participate in controlling the hypothalamo-pituitary-adrenal axis, that central NMU might participate in controlling body temperature, and that central NMS is likely to be involved in behavioral activation in cattle.

Increased basal phosphorylation of mitogen-activated protein kinases and reduced responsiveness to inflammatory cytokines in neutrophils from patients with rheumatoid arthritis.

OBJECTIVE: We studied the functions of peripheral blood (PB) and synovial fluid (SF) neutrophils from patients with rheumatoid arthritis (RA), focusing the molecular basis for the activated state and the functional responsiveness of RA neutrophils to inflammatory cytokines. METHODS: Paired samples of PB neutrophils and SF neutrophils from the inflamed knee joint were obtained from 18 RA patients (5 males and 13 females). RESULTS: RA neutrophils exhibited increased spontaneous superoxide (O2-) release and adherence, increased basal phosphorylation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase, accelerated spontaneous apoptosis, and enhanced O2- release in response to N-formyl-methionyl-leucyl-phenylalanine as compared with healthy normal PB neutrophils. When challenged with granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage CSF (GM-CSF) or tumor necrosis factor alpha (TNF-alpha), RA neutrophils exhibited reduced responses to these cytokines, which included O2- release, adherence, priming for enhanced O2- release, and phosphorylation of ERK and p38. The functional alterations were greater in SF neutrophils than in PB neutrophils from RA. Reduced responsiveness to cytokines in RA neutrophils was closely associated with increased serum and SF levels of GM-CSF and TNF-alpha. RF and RAHA titers were closely correlated with increased TNF-alpha level in SF. CONCLUSION: These findings indicate that RA neutrophils are in the activated state with increased basal phosphorylation of ERK and p38, and exhibit reduced responsiveness to inflammatory cytokines (G-CSF, GM-CSF and TNF-alpha) and accelerated spontaneous apoptosis.

Method development and validation for the simultaneous determination of cinnarizine and co-formulated drugs in pharmaceutical preparations by capillary electrophoresis.

Rapid and simple capillary electrophoresis (CE) methods were developed for the simultaneous determinations of cinnarizine and domperidone (CN/DOM) and cinnarizine and nicergoline (CN/NIC) in their co-formulated tablets. The optimized CE conditions were as follows: running buffer, methanol-acetate buffer (pH 3.0, 10 mM) (80:20 and 85:15 (v/v) for CN/DOM and CN/NIC, respectively); applied voltage, 20 kV; UV detection wavelengths, 215 and 227 nm for CN/DOM and CN/NIC, respectively; hydrodynamic injection was performed at a height of 25 mm for 30 s. Quinine hydrochloride and nicardipine hydrochloride were used as internal standards for the determination of CN/DOM and CN/NIC, respectively. Calibration curves were linear over the ranges 0.25-20/0.375-15 microg/ml (CN/DOM) and 0.25-25/0.4-10 microg/ml (CN/NIC) in each optimized condition. Detection limits were 0.074/0.119 microg/ml and 0.072/0.116 microg/ml for CN/DOM and CN/NIC, respectively. The proposed methods were successfully applied for the simultaneous determination of both CN/DOM and CN/NIC in their co-formulated tablets without interfering peaks due to the excipients present in the pharmaceutical tablets. The estimated amounts of CN/DOM and CN/NIC were almost identical with the certified values, and their percentage relative standard deviation values (%R.S.D.) were found to be < or =2.34% (n=3).

Proposal of a new staging and grading system of the liver for primary biliary cirrhosis.

AIMS: To define a new histological staging and grading system for primary biliary cirrhosis (PBC), to provide more information reflecting clinical laboratory data and the prognosis to hepatologists. METHODS AND RESULTS: First, 17 histological lesions of PBC were scored in 188 needle liver biopsy specimens. Factor analysis yielded three independent groups of factors: factor 1 (fibrosis, fibrous piecemeal necrosis, orcein-positive granules, bile plugs, Mallory bodies, feathery degeneration, bile duct loss and atypical ductular proliferation); factor 2 (portal inflammation, eosinophilic infiltration, lymphoid follicles, epithelioid granulomas, interface hepatitis and chronic cholangitis); and factor 3 (interface hepatitis, lobular hepatitis, acidophilic bodies and pigmented macrophages). The eight findings of factor 1, but not factors 2 and 3, were significantly correlated with clinical laboratory data and scores in the Mayo Clinic's prognostic model. Factor 1 lesions may reflect histological progression (staging), while factor 2 and 3 lesions may relate to necroinflammatory activity (grading). Then, we devised a staging and grading system using three lesions (bile duct loss, fibrosis and orcein-positive granules) from factor 1 and three from factors 2 and 3 (chronic cholangitis, interface hepatitis and lobular hepatitis). CONCLUSION: This new system might provide more pathological information on PBC patients for hepatologists.

Characteristics of periodontal ligament subpopulations obtained by sequential enzymatic digestion of rat molar periodontal ligament.

Periodontal ligament (PDL) consists of different cell populations in various differentiation stages. In the present study, we isolated cell populations from rat molar PDL by sequential enzymatic digestion and characterized growth potential and mineralization activity of the PDL subpopulations (PDL-SP) to throw light on the mechanism of PDL remodeling and, in its turn, periodontal tissue regeneration. PDL attached to extracted rat molars was digested 2 mg/ml collagenase and 0.25% trypsin at 37 degrees C for 30 min. Then four consecutive digestions were performed for 20 min each in a fresh digestive solution. The solutions were centrifuged to collect released cells and 5 PDL subpopulations (30M-, 50M-, 70M-, 90M-and 110M-PDL-SP) were obtained. Light microscopic observation showed that about a half of PDL in width attached on the root surface of extracted teeth and 30M-PDL-SP was considered to contain cells mainly from middle portion of PDL. Scanning electron microscopic examination indicated that 110M-PDL-SP was enriched by root lining cementoblastic cells. 30M-PDL-SP showed a high level of proliferative activity. Although the growth potential of a subpopulation decreased in PDL-SP toward the root surface, 110M-PDL-SP had a high proliferative activity equivalent to that of 30M-PDL-SP. Analyses of alkaline phosphatase (ALP) and mineralization activities showed that higher activities in PDL-SP toward the surface of roots and that 110M-PDL-SP had the highest activity of ALP and the largest number of mineralization nodules. The present study shows as supposed by previous studies on cell kinetics in PDL that subpopulations with larger growth potential were generally located in the middle portion of PDL and those with higher mineralization activities toward the surface of the roots. It is suggested, however, that a possible pathway of PDL cell turnover may exist within the PDL-SP on the root surface in addition to the generally recognized pathway from the middle area of PDL to root surface.

Thrombopoietin stimulates ex vivo expansion of mature neutrophils in the early stages of differentiation.

We examined the effects of thrombopoietin (TPO) in combination with stem cell factor (SCF), interleukin-3 (IL-3), and granulocyte colony-stimulating factor (G-CSF) on the proliferation and differentiation of human neutrophils. Purified CD34(+) hematopoietic progenitor cells were cultivated with SCF, IL-3, and G-CSF for 7 days (early phase), and thereafter nonadherent cells were further cultivated for 9 days with G-CSF alone (late phase). A large number of highly selected neutrophils (>95%) was obtained on day 16. We compared the expansion capacity in the presence or absence of TPO in each culture phase. The significantly larger number of neutrophils was obtained in the presence of TPO in the early culture phase. The number of expanded cells plateaued at day 16. Ultimately, a 550-fold increase in the number of neutrophils was achieved. These neutrophils gained the ability to respond effectively with chemotaxis and superoxide release, and were appropriately primed by G-CSF, granulocyte-macrophage colony-stimulating factor, tumor necrosis factor-alpha, and IL-1beta for enhanced release of O(2)(-). The responsiveness of these cells was identical to that of peripheral blood neutrophils. However, TPO did not accelerate the maturation of neutrophils supported by G-CSF in the late phase of culture. Furthermore, priming effects and triggering effects of TPO on the production of superoxide metabolites from peripheral blood neutrophils were not observed. These results suggest that TPO regulates the proliferation and differentiation of neutrophils in the early stages, but not the late stages, of differentiation.