Nematic Correlation Length in Iron-Based Superconductors Probed by Inelastic X-Ray Scattering.

Nematicity is ubiquitous in electronic phases of high-T_{c} superconductors, particularly in the Fe-based systems. We used inelastic x-ray scattering to extract the temperature-dependent nematic correlation length ξ from the anomalous softening of acoustic phonon modes in FeSe, underdoped Ba(Fe_{0.97}Co_{0.03})_{2}As_{2}, and optimally doped Ba(Fe_{0.94}Co_{0.06})_{2}As_{2}. In all cases, we find that ξ is well described by a power law (T-T_{0})^{-1/2} extending over a wide temperature range. Combined with the previously reported Curie-Weiss behavior of the nematic susceptibility, these results point to the mean-field character of the nematic transition, which we attribute to a sizable nematoelastic coupling that is likely detrimental to superconductivity.

Faecal freezing preservation period influences colonization ability for faecal microbiota transplantation.

AIMS: There has been growing interest in faecal microbiota transplantation (FMT) as treatment. Although, frozen donor faeces preserved at -20°C has been widely used for practical advantages, freezing at -20°C can affect bacterial viability. Adequacy evaluation of fresh and frozen faeces as the transplant is necessary for the methodological improvement of FMT. METHODS AND RESULTS: The viable bacterial compositions of faecal specimens under fresh and freezing conditions were compared by a microbiome analysis using propidium monoazide (PMA microbiome). In addition, recovery abilities from bacterial reduction by antibiotics were compared between fresh and frozen FMT using a murine model. PMA microbiome results suggested that freezing and freeze-thawing did not significantly affect in vitro faecal bacterial viability. However, the recovery effect from antimicrobial cleansing in frozen FMT was reduced in a freezing time-dependent manner, especially prominent in Actinobacteria and Bacteroidetes phyla. CONCLUSIONS: Short-term freezing preservation of faeces exhibited maintenance of enteric colonization ability in frozen FMT in comparison to 1 month -20°C-preservation. SIGNIFICANCE AND IMPACT OF THE STUDY: Long-term -20°C-preservation of transplanted faeces can result in instability of the clinical outcome in FMT therapy. The standardization of practical procedures of FMT therapy according to disease types is desirable.

Early maternal separation promotes alterations in the thermoregulatory profile of adult Wistar rats.

Stressful lifelong events may influence psychiatric diseases, like depression and anxiety. Interestingly, depressed patients have dysfunction of thermoregulatory cooling mechanisms. Thus, understanding the mechanisms related to the thermoregulatory changes in stress-related pathologies is important to better understand the symptoms and treatments for those diseases. However, the influence of early-life stress on the thermoregulatory profile of adults is unknown. In this study, we aimed to evaluate the thermoregulatory profile of adult male Wistar rats submitted to early-life stress by maternal separation (MS). On postnatal days 2-14, rats were submitted daily to MS for 3 h per day. At 3-4 months of age, anxiety-like behavior was evaluated using the open field test and elevated plus maze, depression-like behavior was evaluated using the forced swim test and thermoregulatory profile were also evaluated. In the behavioral tests, MS animals exhibited anxiety- and depression-like behaviors, and had higher core body temperatures during dark period of the circadian cycle, when compared to controls. In addition, MS animals presented higher hyperthermic and vasoconstriction responses than control animals when exposed to the warmth environment, and engaged in cold-seeking behavior whenever possible to select their preferred ambient temperature. The results suggest that, besides emotional alterations, MS induces a change in the thermoregulatory profile of rats that persists into adulthood.

Observation of low- and high-energy Gamow-Teller phonon excitations in nuclei.

Gamow-Teller (GT) transitions in atomic nuclei are sensitive to both nuclear shell structure and effective residual interactions. The nuclear GT excitations were studied for the mass number A = 42, 46, 50, and 54 "f-shell" nuclei in ((3)He, t) charge-exchange reactions. In the (42)Ca → (42)Sc reaction, most of the GT strength is concentrated in the lowest excited state at 0.6 MeV, suggesting the existence of a low-energy GT phonon excitation. As A increases, a high-energy GT phonon excitation develops in the 6-11 MeV region. In the (54)Fe → (54)Co reaction, the high-energy GT phonon excitation mainly carries the GT strength. The existence of these two GT phonon excitations are attributed to the 2 fermionic degrees of freedom in nuclei.

Complete electric dipole response and the neutron skin in 208Pb.

A benchmark experiment on (208)Pb shows that polarized proton inelastic scattering at very forward angles including 0° is a powerful tool for high-resolution studies of electric dipole (E1) and spin magnetic dipole (M1) modes in nuclei over a broad excitation energy range to test up-to-date nuclear models. The extracted E1 polarizability leads to a neutron skin thickness r(skin) = 0.156(-0.021)(+0.025) fm in (208)Pb derived within a mean-field model [Phys. Rev. C 81, 051303 (2010)], thereby constraining the symmetry energy and its density dependence relevant to the description of neutron stars.

Low energy excitation in liquid Sb and liquid Bi observed in inelastic x-ray scattering spectra.

The dynamic structure factorS(Q,E), whereQandEare momentum and energy transfer, respectively, has been measured for liquid Sb, using inelastic x-ray scattering. A modified damped harmonic oscillator model function was applied to analyseS(Q,E) of liquid Sb and also to that of liquid Bi by Inuiet al(2015Phys. Rev.B92, 054206). The obtained excitation energy was in fairly good agreement with that predicted byab initiomolecular dynamics simulations on these liquid semi-metals. The excitation energy of the longitudinal acoustic mode in liquid Sb and liquid Bi exhibits flat-toppedQdependence whereas the lower excitation energy below the longitudinal acoustic excitation showsQ-gap behaviour. From the viscosity estimated from theQ-gap experimentally obtained, it is inferred that the lower energy excitation arises from the transverse acoustic excitation in the liquids.

Temperature gradient analyzers for compact high-resolution X-ray spectrometers.

Compact high-resolution X-ray spectrometers with a one-dimensional temperature gradient at the analyzer crystal are considered. This gradient, combined with the use of a position-sensitive detector, makes it possible to relax the usual Rowland-circle condition, allowing increased space at the sample position for a given energy resolution or arm radius. Thus, for example, it is estimated that approximately meV resolution is possible with a 3 m analyzer arm and 200 mm clearance between the sample and detector. Simple analytic formulae are provided, supported by excellent agreement with ray-tracing simulations. One variation of this method also allows the detector position sensitivity to be used to determine momentum transfer, effectively improving momentum resolution without reducing (slitting down) the analyzer size. Application to medium-resolution ( approximately 10-100 meV) inelastic X-ray scattering spectrometers with large angular acceptance is discussed, where this method also allows increased space at the sample. In some cases the application of a temperature gradient can improve the energy resolution even with a single-element detector.

Viscoelastic anomaly accompanying anti-crossing behaviour in liquid As2Se3.

We investigate the dynamic structure factor of the melt of the well known glass former, As2Se3, using inelastic x-ray scattering for temperatures, T, [Formula: see text] K and momentum transfers Q from [Formula: see text] nm-1. An anomaly was observed at Q = 2.7 nm-1 ([Formula: see text] K) with, in the context of a simple model, both an abrupt change in frequency and an increased linewidth reminiscent of an anti-crossing in a solid. Comparison with structural information from reverse Monte Carlo modeling of x-ray diffraction data allows us to associate the disappearance of the anomaly at higher temperatures with a drop in the number of mechanical constraints per atom, n mc, to [Formula: see text] reminiscent of the threshold applicable for glass formation in rigidity theory. It is inferred that the surprising jump in the dispersion in the liquid may be correlated with a stiffness transition in a network glass.

Clustering of glycoprotein VI (GPVI) dimers upon adhesion to collagen as a mechanism to regulate GPVI signaling in platelets.

Essentials Dimeric high-affinity collagen receptor glycoprotein VI (GPVI) is present on resting platelets. Spatio-temporal organization of platelet GPVI-dimers was evaluated using advanced microscopy. Upon platelet adhesion to collagenous substrates, GPVI-dimers coalesce to form clusters. Clustering of GPVI-dimers may increase avidity and facilitate platelet activation SUMMARY: Background Platelet glycoprotein VI (GPVI) binding to subendothelial collagen exposed upon blood vessel injury initiates thrombus formation. Dimeric GPVI has high affinity for collagen, and occurs constitutively on resting platelets. Objective To identify higher-order oligomerization (clustering) of pre-existing GPVI dimers upon interaction with collagen as a mechanism to initiate GPVI-mediated signaling. Methods GPVI was located by use of fluorophore-conjugated GPVI dimer-specific Fab (antigen-binding fragment). The tested substrates include Horm collagen I fibers, soluble collagen III, GPVI-specific collagen peptides, and fibrinogen. GPVI dimer clusters on the platelet surface interacting with these substrates were visualized with complementary imaging techniques: total internal reflection fluorescence microscopy to monitor real-time interactions, and direct stochastic optical reconstruction microscopy (dSTORM), providing relative quantification of GPVI cluster size and density. Confocal microscopy was used to locate GPVI dimer clusters, glycoprotein Ib, integrin α2 ß1 , and phosphotyrosine. Results Upon platelet adhesion to all collagenous substrates, GPVI dimers coalesced to form clusters; notably clusters formed along the fibers of Horm collagen. dSTORM revealed that GPVI density within clusters depended on the substrate, collagen III being the most effective. Clusters on fibrinogen-adhered platelets were much smaller and more numerous; whether these are pre-existing oligomers of GPVI dimers or fibrinogen-induced is not clear. Some GPVI dimer clusters colocalized with areas of phosphotyrosine, indicative of signaling activity. Integrin α2 ß1 was localized to collagen fibers close to GPVI dimer clusters. GPVI clustering depends on a dynamic actin cytoskeleton. Conclusions Platelet adhesion to collagen induces GPVI dimer clustering. GPVI clustering increases both avidity for collagen and the proximity of GPVI-associated signaling molecules, which may be crucial for the initiation and persistence of signaling.

Ganglioside GD1alpha functions in the adhesion of metastatic tumor cells to endothelial cells of the target tissue.

We studied the role of glycosphingolipids expressed on the cell surfaces of a metastatic tumor cell line. Glycosphingolipid compositions of the low-metastatic murine lymphosarcoma cell line RAW117-P and its sub-line, RAW117-H10, which shows higher metastatic potential for the liver than P cells, were compared. Both types of cells had LacCer, Gg3Cer, and Gg4Cer as the major neutral glycosphingolipids and GM1b and GD1alpha as the gangliosides. There are differences in glycosphingolipid contents, the neutral glycosphingolipid contents in the parental cells being 1.5-fold higher than that in the variant ones. In contrast, the level of GD1alpha in H10 cells was twice as much as that in the P cells; however, the expression of other gangliosides was down-regulated. On the basis of the results of glycosphingolipid analysis, we investigated the functional role of GD1alpha in H10 cells in the adhesion of the tumor cells to the target tissue by using hepatic sinusoidal endothelial (HSE) cells. GD1alpha and GM1b inhibited the adhesion when HSE cells were incubated prior to coculture with the tumor cells. This inhibitory effect by GD1alpha and GM1b was observed within 30 min after addition of H10 cells to HSE cells and was dose dependent. GD1alpha showed a higher inhibitory effect on the adhesion than GM1b, whereas other glycosphingolipids showed no inhibitory effect. Anti-GD1alpha monoclonal antibody also inhibited the adhesion between the H10 and HSE cells. When cultured without fetal bovine serum for 30 min in a various glycosphingolipids-coated dish for bacterial culture, HSE cells adhered to the area coated with GD1alpha but not to areas coated with other glycosphingolipids. HSE cell adhesion depended on the amount of GD1alpha coated on the plate. These data indicate that GD1alpha functions as an adhesion molecule in the process of metastasis of H10 cells.

TRPV4 activates autonomic and behavioural warmth-defence responses in Wistar rats.

AIM: In this study, we aimed at investigating the involvement of the warmth-sensitive channel - TRPV4 (in vitro sensitive to temperatures in the range of approx. 24-34 °C) - on the thermoregulatory mechanisms in rats. METHODS: We treated rats with a chemical selective agonist (RN-1747) and two antagonists (RN-1734 and HC-067047) of the TRPV4 channel and measured core body temperature, metabolism, heat loss index and preferred ambient temperature. RESULTS: Our data revealed that chemical activation of TRPV4 channels by topical application of RN-1747 on the skin leads to hypothermia and this effect was blocked by the pre-treatment with the selective antagonist of this channel. Intracerebroventricular treatment with RN-1747 did not cause hypothermia, indicating that the observed response was indeed due to activation of TRPV4 channels in the periphery. Intravenous blockade of this channel with HC-067047 caused an increase in core body temperature at ambient temperature of 26 and 30 °C, but not at 22 and 32 °C. At 26 °C, HC-067047-induced hyperthermia was accompanied by increase in oxygen consumption (an index of thermogenesis), while chemical stimulation of TRPV4 increased tail heat loss, indicating that these two autonomic thermoeffectors in the rat are modulated through TRPV4 channels. Furthermore, rats chemically stimulated with TRPV4 agonist choose colder ambient temperatures and cold-seeking behaviour after thermal stimulation (28-31 °C) was inhibited by TRPV4 antagonist. CONCLUSION: Our results suggest, for the first time, that TRPV4 channel is involved in the recruitment of behavioural and autonomic warmth-defence responses to regulate core body temperature.

Ferroelectric-like metallic state in electron doped BaTiO3.

We report that a ferroelectric-like metallic state with reduced anisotropy of polarization is created by the doping of conduction electrons into BaTiO3, on the bases of x-ray/electron diffraction and infrared spectroscopic experiments. The crystal structure is heterogeneous in nanometer-scale, as enabled by the reduced polarization anisotropy. The enhanced infrared intensity of soft phonon along with the resistivity reduction suggests the presence of unusual electron-phonon coupling, which may be responsible for the emergent ferroelectric structure compatible with metallic state.

Preparation of peptides which mimic glycosphingolipids by using phage peptide library and their modulation on beta-galactosidase activity.

We describe the use of a phage-displayed random pentadecamer peptide library for searching glycosphingolipid mimicking peptides. Two phage clones (AD-1 and AD-2) were selected by biopanning using monoclonal antibody AD117m, directed to lactotetraosylceramide (Lc4Cer). The amino acid sequences of the selected clones showed high homology (VPPXFXXXY) in 9-mer. Three phage clones were selected by using monoclonal antibody H11, directed to neolactotetraosylceramide (nLc4Cer), the linkage isomer of Lc4Cer, and the displayed amino acid sequences were compared. One of these peptides showed the same amino acid sequence as that of AD-2 except for one amino acid substitution. Pentadecamer, 9-mer and point mutated 9-mer peptides were synthesized on the basis of the displayed amino acid sequences. Binding activity of the peptides to the monoclonal antibodies or Ricinus communis lectin showed that 9-mer peptides are enough to mimic the epitope carbohydrate structure. Furthermore, six of the synthesized peptides inhibited Jack bean beta-galactosidase activity towards nLc4Cer at a high concentration of the enzyme, whereas at lower enzyme concentrations some peptides showed potent activation of the enzyme activity. This is the first report of carbohydrate mimicking peptides which modulate glycosidase activity.

Selection of ganglioside GM1-binding peptides by using a phage library.

Ganglioside Gal beta1 --> 3GalNAc beta1 --> 4(NeuAc alpha2 --> 3) Gal beta1 --> 4Glc beta1 -->1'Cer (GM1)-binding peptides were obtained from a phage-displayed pentadecapeptide library by an affinity selection. The selection processes were in situ-monitored by a quartz-crystal microbalance method, on which a ganglioside GM1 monolayer was transferred. After five rounds of biopanning, the DNA sequencing of 18 selected phages showed that only three individual clones were selected. The peptide sequences of the random region were found to be DFRRLPGAFWQLRQP, GWWYKGRARPVSAVA and VWRLLAPPFSNRLLP. Binding constants of these phage clones to the GM1 monolayer were 10(10) M(-1). Three synthetic pentadecapeptides inhibited the binding of cholera toxin B subunit to the GM1 monolayer with an IC50 of 24, 13 and 1.0 microM, respectively. These peptides will be useful for searching functional roles of ganglioside GMI.

GD1alpha-replica peptides functionally mimic GD1alpha, an adhesion molecule of metastatic tumor cells, and suppress the tumor metastasis.

A novel peptide technology to produce mimicking peptides of carbohydrate moiety (which we propose to name glyco-replica peptides) is a useful tool to elucidate the functions of glycoconjugate. Carbohydrate moiety of ganglioside GD1alpha functions as a molecule involved in the adhesion between murine highly metastatic lymphoma RAW117-H10 cells and hepatic sinusoidal endothelial (HSE) cells. To prepare peptides which mimic the carbohydrate structure of GD1alpha, phage clones expressing peptides which bound to a monoclonal antibody against GD1alpha (KA17) were isolated from a phage-displayed random peptide library. Four phage clones having affinity to the monoclonal antibody KA17 were isolated, and these clones showed inhibitory effect on the binding of KA17 to GD1alpha. The amino acid sequences of the displayed pentadecamers were determined, and one of the phages displaying sequence WHWRHRIPLQLAAGR bound to HSE cells directly and showed the highest inhibitory effect on the adhesion between RAW117-H10 cells and HSE cells. The synthesized peptides having the same sequences to the displayed 15mers in the four isolated phage clones also showed the inhibitory effect on the adhesion of RAW117-H10 cells to HSE cells, and, again, the WHWRHRIPLQLAAGR peptide showed the highest inhibitory effect. Furthermore, intravenous injection of the peptide brought almost complete inhibition of the metastasis of RAW117-H10 cells to lung and spleen, and about 50% inhibition of the liver metastasis. These results indicate that GD1alpha plays an important role for metastasis of RAW117-H10 cells, and the peptides obtained by the present procedure are able to mimic the functional role of the glycoconjugate.

Suppression of GD1alpha ganglioside-mediated tumor metastasis by liposomalized WHW-peptide.

GD1alpha ganglioside-replica peptides were recently isolated from a phage-displayed random pentadecapeptide library by assaying for inhibition of adhesion of RAW117-H10 lymphosarcoma cells to hepatic sinusoidal microvessel endothelial (HSE) cells. We show here that the Trp-His-Trp (WHW) peptide was identified as a minimal sequence of the GD1alpha-replica peptide WHWRHRIPLQLAAGR. The addition of WHW peptide-attached liposomes displayed efficient inhibition of liver metastasis of RAW117-H10 cells as well as of GD1alpha-mediated adhesion of RAW117-H10 cells to HSE cells in vitro. These results suggest that engineered liposomes for peptide delivery are applicable to treatment for metastasis.

Epitope mapping of rat neutralizing monoclonal antibody against human immunodeficiency virus type-1 by a phage peptide library: comparison with ELISA using synthetic peptides.

We generated a rat monoclonal antibody (mAb W#10) with the ability to neutralize human immunodeficiency virus type 1IIIB (HIV-1IIIB) infection. The epitope recognized by mAb W#10 was defined as R-I-Q-R-G-P-G by enzyme-linked immunosorbent assay (ELISA) with the use of synthetic peptides. The filamentous phage clones displaying random 15-amino-acid peptides on the amino terminus of the pIII coat protein reacting with mAb W#10 were identified with affinity and immunological selection procedures. Thirteen out of 16 selected phage clones contained the G-X-G-R-X-F sequence in the coat protein region representing significant homology to a part of conserved G-P-G-R-A-F sequence in the V3 loop of various HIV-1 strains. In addition, the phage clones included the G-X-G sequence in the sequence detected by synthetic peptides as the recognition site. The selected phage clones were stained by mAb W#10 specifically and were able to compete with mAb binding to cells expressing viral antigens.

Tyrosine phosphorylation of protein kinase C delta-isoform and its association with membrane.

Stimulation of CHO cells stably overexpressing the delta-isoform of protein kinase C (delta PKC) by phorbol ester resulted in the tyrosine phosphorylation and association of the enzyme with particulate fraction. This tyrosine phosphorylation of delta PKC occurred preferentially in the enzyme prephosphorylated at serine/threonine residue(s). The enzymatic activity of tyrosine-phosphorylated delta PKC was dependent on both phospholipid and diacylglycerol which is the same as the non-tyrosine-phosphorylated form, and no significant difference was observed between the two forms for their kinetic properties and specific activities. When delta PKC was phosphorylated at tyrosine in vitro, phosphatidylserine and either diacylglycerol or phorbol ester were needed for the maximal rate of the reaction, suggesting that the tyrosine phosphorylation is a consequence of, but not a prerequisite for the enzyme activation. The tyrosine-phosphorylated delta PKC was associated with the particulate fraction, and presumably exists as a large complex in the membrane of the stimulated cells. It may be possible that the tyrosine phosphorylation is related to sustained activation and/or targeting of the delta PKC isoform.

[A case of orbital lymphoproliferative lesion diagnosed as malignant lymphoma after recurring 11 years later].

BACKGROUND: Most primary lymphoproliferative lesions in the ocular adnexa, including the eyelid, conjunctiva, and orbit, are diagnosed as low-grade malignant lymphomas. Recurrence and dissemination of these tumors are rare in Japan. The long-term prognosis for this disorder still remains to be clarified. CASE AND METHOD: A 53-year-old woman was first referred to us for right orbital tumor in 1986. After subtotal resection of the tumor, the patient received no additional treatment. She visited us in 1997 with the complaint of bilateral orbital tumor. Biopsied specimens were examined histologically using hematoxylin-eosine and immunohistological staining. Southern blot hybridization was used to detect immunoglobulin gene rearrangement. The paraffin-embedded specimen obtained in 1986 was also examined for immunoglobulin gene rearrangement using nested polymerase chain reaction technique. FINDINGS: The specimens from 1997 and 1986 were both diagnosed as lymphoid type of inflammatory pseudotumor, based on polyclonal B cell immunohistological staining. Immunoglobulin gene rearrangement was present in both specimens. CONCLUSION: The orbital tumor resected in 1986 was a low-grade malignant lymphoma which disseminated systemically 11 years later. This case shows a long-term course of orbital lymphoproliferative lesion with positive immunoglobulin gene rearrangement. It also shows the importance of follow-up over 10 years in the case of low-grade malignant lymphoma of the ocular adnexa.