Liquid-like thermal conduction in intercalated layered crystalline solids.

As a generic property, all substances transfer heat through microscopic collisions of constituent particles 1 . A solid conducts heat through both transverse and longitudinal acoustic phonons, but a liquid employs only longitudinal vibrations2,3. As a result, a solid is usually thermally more conductive than a liquid. In canonical viewpoints, such a difference also serves as the dynamic signature distinguishing a solid from a liquid. Here, we report liquid-like thermal conduction observed in the crystalline AgCrSe2. The transverse acoustic phonons are completely suppressed by the ultrafast dynamic disorder while the longitudinal acoustic phonons are strongly scattered but survive, and are thus responsible for the intrinsically ultralow thermal conductivity. This scenario is applicable to a wide variety of layered compounds with heavy intercalants in the van der Waals gaps, manifesting a broad implication on suppressing thermal conduction. These microscopic insights might reshape the fundamental understanding on thermal transport properties of matter and open up a general opportunity to optimize performances of thermoelectrics.

Inelastic and quasi-elastic neutron scattering spectrometers in J-PARC.

J-PARC, Japan Proton Accelerator Research Complex provides short pulse proton beam at a repetition rate 25Hz and the maximum power is expected to be 1MW. Materials and Life Science Experimental Facility (MLF) has 23 neutron beam ports and 21 instruments have already been operated or under construction/commissioning. There are 6 inelastic/quasi-elastic neutron scattering spectrometers and the complementary use of these spectrometers will open new insight for life science. This article is part of a Special Issue entitled "Science for Life" Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo.

Highly efficient chip-scale III-V/silicon hybrid optical amplifiers.

We discuss the design and demonstration of highly efficient 1.55 µm hybrid III-V/Silicon semiconductor optical amplifiers (SOA). The optimized III-V wafer stack consists of Al(0.10)In(0.71)Ga(0.18)As multiple quantum wells (MQW) and Al(0.48)In(0.52)As electron stop layers to realize SOAs with high wall-plug efficiency (WPE). We present various designs and experimentally determine WPE values for 2 mW and 0.1 mW input power amplification. The 400 µm long flared SOA achieved the highest WPE value of 12.1% for output power > 10mW and the 400 µm long straight SOA achieved the highest WPE value of 7.3% for output power < 10mW. These are the highest WPE values ever obtained for 1.55 µm SOAs.

Intermediate-range chemical ordering of cations in molten RbCl-AgCl.

A first sharp diffraction peak (FSDP) is observed in the X-ray total structure factor of a molten mixture of RbCl-AgCl, while both pure melts of RbCl and AgCl do not exhibit FSDP individually. Molecular dynamics simulations were performed to investigate the origin of the FSDP with the polarizable ion model (PIM). Coexistence of covalent Ag-Cl and ionic Rb-Cl bonds leads the system to evolve intermediate range ordering, which is simulated by introducing the induced polarization in different ways between Ag-Cl with fully polarizable treatment based on Vashishta-Raman potential and Rb-Cl with suppression over-polarization in the nearest neighbor contribution based on Born-Meyer potential. The partial structure factors for both the Ag-Ag and Rb-Rb correlations, SAgAg(Q) and SRbRb(Q), show a positive contribution to the FSDP, while SAgRb(Q) for the Ag-Rb correlation exhibits a negative contribution, indicating that Ag and Rb ions are distributed in an alternating manner within the intermediate-range length scale. The origin of the intermediate-range chemical ordering of cations can be ascribed to the preferred direction of the dipole moments of anions in the PIM.

Structural disorder in lithium lanthanum titanate: the basis of superionic conduction.

High-energy x-ray and neutron diffraction measurements on polycrystalline La(2/3-x)Li(3x)TiO(3) (0.075 < x < 0.165) were performed. The total scattering structure factors were analysed by the reverse Monte Carlo (RMC) modelling technique, resulting in three-dimensional particle configurations. These configurations were then used for revealing the distributions of La and Li ions and to understand the relationship between these distributions and ionic conduction. An alternating arrangement of La-rich and La-poor layers along the c-axis was found in the x = 0.075 composition. Intriguingly, this arrangement has gradually disappeared in samples with higher Li concentration. Furthermore, RMC models exhibit disordered distributions of Li ions, situated mainly on the La-rich layer, and there is a significant probability of Li ions occupying the interstitial sites (T site) between the O-3 triangle plane of the TiO(6) octahedron and an La ion or its vacancy site. It was also found on the basis of the RMC models that the bond valence sum (BVS) for Li ions behaves differently on La-rich and La-poor layers at low Li concentration compositions, but they are similar at high Li concentration compositions. This is consistent with the behaviour of the alternating arrangement of La-rich and La-poor layers. It is also suggested that the Li ions around the bottleneck at (1/2, 0, 0) (bottom layer) can jump to an adjacent bottleneck at (0, 1/2, 0) through the T site and not only Li ions in the La-poor layers but also Li ions in the La-rich layers contribute to the bottleneck-bottleneck Li conduction.

Radioiodination of glycoprotein-conjugated liposomes by using the Bolton-Hunter reagent and biodistribution in tumor-bearing mice.

We have developed a suitable radiolabeling method for our new type of glycoprotein-liposome conjugate (GCL), in order to investigate its potential utility as a drug carrier that can target the cellular functions of carbohydrate-binding proteins. In order to obtain radiolabeled GCL with high labeling efficiency, we introduced p-hydroxyphenylpropyl groups into the liposome membrane through the amine moiety of a constitutive phospholipid, dipalmitoylphosphatidylethanolamine (DPPE) by using Bolton-Hunter reagent (BHR). Radioiodination of the introduced tyrosyl groups was performed by the Chloramine-T method. The labeling efficiency of the BHR-treated liposome conjugate was high in comparison with that of the BHR-untreated liposome conjugate. An in vitro inhibition study showed that the binding affinity of 125I-labeled BHR-treated GCL (125I-F3S-BH) with lectin was twice as high as that of untreated conjugate (125I-F3S). The biodistribution of 125I-F3S-BH in mice was considerably different from that of 125I-F3S. 125I-F3S-BH was more rapidly taken up by the liver and was more rapidly excreted from the liver than 125I-F3S. Moreover, 125I-F3S-BH accumulated more rapidly into the kidneys, which resulted a lower radioactivity in the blood circulation at an earlier time point than in the case of 125I-F3S. The characteristics of tumor accumulation of 125I-F3S-BH and 125I-F3S were similar to those in blood. If F3S is to be employed as an in vivo targeting ligand in biodistribution studies, BHR would be a suitable tool for radiolabeling because it allows GCL to retain the biological activity and characteristics of the unmodified conjugate.

Comparison of amino acid sequence of the C-terminal domain of insulin-responsive glucose transporter (GLUT4) in livestock mammals.

The nucleotide sequence of cDNA coding the 38-amino acid of the C-terminal domain of insulin-responsive glucose transporter (GLUT4) was determined by the method of reverse transcription-polymerase chain reaction in the sheep, goat and pig, and compared with that of bovine which have been shown to have a unique amino acid conversion of Asn508 to His. The deduced amino acid sequence was completely identical in the three species, and did not have the amino acid conversion at position 508. Western blot analysis confirmed that an antiserum raised against a rat C-terminal peptide cross-reacted efficiently with GLUT4 of these livestock mammals.

Prenatal diagnosis of Fukuyama type congenital muscular dystrophy in eight Japanese families by haplotype analysis using new markers closest to the gene.

We conducted prenatal diagnosis by haplotype analysis, using newly developed microsatellite markers, in eight Fukuyama type congenital muscular dystrophy (FCMD) families. In addition to six new families, two previously reported families were reexamined by haplotype analysis including detection of an ancestral founder haplotype (138-183-301) for 3 microsatellite markers closest to the FCMD gene, designated D9S2105-D9S2107-D9S172, the distances of which from the FCMD gene are presumed to be approximately 140, approximately 20, and approximately 280 kb, respectively. Five fetuses from five families were diagnosed as nonaffected, and were subsequently confirmed to be healthy. Three fetuses of the other three families were diagnosed as having a high probability of being affected by FCMD. In the prenatal diagnosis conducted for these eight families, the ancestral founder allele was observed in 13 of 16 (81%) FCMD-bearing chromosomes. Detection of the ancestral haplotype facilitated achieving accurate prenatal diagnosis of FCMD. The brains of all three fetuses prenatally diagnosed as FCMD-affected showed the initial stage of cortical dysplasia, strong evidence of FCMD.

Dietary skim milk powder increases ionized calcium in the small intestine of piglets compared to dietary defatted soybean flour.

Calcium distribution was studied in the small intestine of piglets fed skim milk powder (SMP) or defatted soybean flour (DSF ) to investigate the relationship between calcium availability and its forms. Ionized calcium in duodenal and ileal digesta was measured with a selective calcium electrode that was not affected by changes in pH or sodium, potassium and magnesium concentrations, which simulated the liquid phases of digesta. Eight piglets were fed DSF-based diet or SMP-based diet for 30 d, and duodenal and ileal digesta were collected. Soluble calcium concentrations in the ileum were higher in the SMP-fed group than in the DSF-fed group. The proportion of soluble calcium in higher-molecular-weight fraction (MW > 3000) was significantly greater in the ileum than in the duodenum of the SMP group, but did not differ between these intestinal segments within the DSF group. This proportion was significantly higher in the ileum of the SMP-fed group than in that of the DSF-fed group. In the ileum, ionized calcium concentration was significantly greater in the SMP-fed group than in the DSF-fed group. These results suggest that the increase of calcium in the higher-molecular-weight fraction raises soluble calcium concentration and changes the distribution of calcium in the ileum of the SMP-fed group. The complexes of calcium with higher-molecular-weight ligands may be easily exchangeable with ionized calcium, and the increase in these calcium complexes may consequently enhance the recruitment of ionized calcium, which then can be absorbed.

Scheduled feeding caused activation of dopamine metabolism in the striatum of rats.

The effects of a time-restricted feeding schedule on dopamine (DA) release and its metabolites output in the striatum of freely moving rats were studied. Rats had access to food for only 2 h daily for 7 successive days. On the 1st or 7th day, the extracellular concentrations of DA, 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) in the ventrolateral striatum were measured by in vivo brain microdialysis during 2 h of exposure to food-related stimuli followed by 2 h of access to food. Extracellular concentrations of DA and its metabolites did not change during the period of exposure to food-related stimuli or during feeding on the 1st day. On the 7th day, extracellular DOPAC and HVA concentrations increased significantly during 2 h of feeding, but not during exposure to food-related stimuli, compared with basal levels. Extracellular DA concentration did not change significantly. These results indicate that scheduled feeding caused activation of DA metabolism in the ventrolateral striatum and facilitate feeding-related motor activity in feeding behavior.

Reduced bone density and major hormones regulating calcium metabolism in anorexia nervosa.

Bone density of lumbar vertebrae (L2 to L4) and the whole body in 29 patients with anorexia nervosa were measured by dual photon absorptiometry, and the results were compared with those of 10 age-matched normal controls. The patients had significantly lower bone mineral density (BMD) in L3 and L2-4 than controls. However, there was no difference in whole-body BMD. L3 and L2-4 BMD was positively correlated with body weight and was negatively correlated with duration of illness and amenorrhea. Patients who had been more active 6 months before the time of the study had significantly higher L3 BMD than the less active patients. Most patients had an abnormally low serum estrogen level, whereas the mean serum levels of thyroid hormone (T3, T4), cortisol, calcitonin, parathyroid hormone and vitamin D were within the normal range. No correlation was found between L3 or L2-4 BMD and the levels of these hormones. These results suggest that severe weight loss, low physical activity, longer duration of amenorrhea and deficiency of estrogen contribute to bone loss in patients with anorexia nervosa, whereas calcium-regulating hormones such as parathyroid hormone, calcitonin and vitamin D are unlikely to be a primary contributor to bone loss.

Effects of morphine and D-Ala2-D-Leu5-enkephalin in the seizure-susceptible El mouse.

Opioid agonists were used to investigate the modulation of seizures in the seizure-susceptible El mouse. Morphine and D-Ala2-D-Leu5-enkephalin (DADLE) were injected subcutaneously or intracisternally as prototypic agonists for mu and delta opioid receptors. Systemic or intracisternal injection of both morphine and DADLE decreased the incidence of seizures and the seizure score in El mice in a dose-dependent manner. The anticonvulsant effects of morphine and DADLE were reversed by naloxone (2 mg/kg, s.c.). This implies that opioid agonists have anticonvulsant properties which are mediated by mu and delta opioid receptors. In conclusion, a deficit in endogenous opioid peptides, which act as anticonvulsants may play a significant role in the etiology or pathophysiology of seizures in the El mouse.

Simultaneous flexion of the thumb and index finger after a fracture of the first metacarpal bone. A case report.

We report a case in which simultaneous flexion of the thumb and index finger occurred after a fracture of the 1st metacarpal bone. This was demonstrated to be due to a fibrous adhesion around an anomalous slip between the tendons of flexor pollicis longus and flexor digitorum profundus indicis.

Simultaneous flexion of the thumb and index finger after a fracture of the first metacarpal bone : A case report.

We report a case in which simultaneous flexion of the thumb and index finger occurred after a fracture of the 1st metacarpal bone. This was demonstrated to be due to a fibrous adhesion around an anomalous slip between the tendons of flexor pollicis longus and flexor digitorum profundus indicis.

Sequence complexity of polyadenylated RNA from seizure-susceptible El mouse brain polysomes.

The hybridization kinetics in the complementary DNAs (cDNA) to polyadenylated messenger RNA (mRNA) in the brain of seizure-susceptible El mice were examined to elucidate the correlation between seizure susceptibility and genetic expression. Homologous and heterologous saturation hybridizations indicated that cDNA of seizure-nonsusceptible ddY mice hybridized with less mRNA in seizure-experienced El(+) or seizure-nonexperienced El(o) mice than that in ddY mice, cDNA of El(+) mice hybridized to a lesser extent with mRNA of El(o) mice than that of ddY or El(+) mice, and no difference was observed with cDNA hybridization results of El(o) mice to individual mRNAs of ddY, El(+) or El(o) mice. The results suggest that some sequences found in mRNA of ddY are lacking in both El strains and are responsible for the inbred predisposition, while those present in El(+) mRNA but missing in El(o) may associate with seizure susceptibility, since common sequences are present in the mRNA of those groups of animal. The sequence diversity among the 3 groups of mice was mainly observed with the rare class of mRNA. Molecular cloning of the cDNA corresponding to this class of mRNA found in the El(+) mice would clarify the gene expression in the brains of epileptics.

Ventricular enlargement in normal weight bulimia.

Cranial computed tomography (CT) scans of 17 patients with bulimia were compared with those of 21 age- and sex-matched controls. The ventricular brain ratio (VBR) of the bulimics was 7.29, which was significantly greater than the 4.55 seen in controls. However, no correlation was found between VBRs and clinical variables, endocrine or metabolic parameters.