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The side chain dynamics of poly(quinoxaline-2,3-diyl)s (PQXs) are expected to influence their conformation. To investigate these dynamics experimentally, quasielastic neutron scattering (QENS) was performed for PQXs in deuterated tetrahydrofuran (THF-d8) and deuterated 1,1,2-trichloroethane/THF (1,1,2-TCE-d3/THF-d8), in which they formed right-handed and left-handed helical structures, respectively. The mean-square displacement of the PQX side chains in 1,1,2-TCE-d3/THF-d8 was lower than that in THF-d8. Furthermore, QENS complementary studies and molecular dynamics simulations unraveled a coupling between the main-chain and side chain dynamics of PQXs, suggesting the possibility of controlling the main-chain helical chirality through the dynamics of chiral side chains. These insights present a novel strategy for the design of synthetic helical macromolecules with precise chirality control.
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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.
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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.
Assuntos
Elasticidade , Difração de Nêutrons/instrumentação , Análise Espectral/instrumentação , DNA/química , Japão , Bicamadas Lipídicas/química , Fônons , Prótons , Água/químicaRESUMO
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.
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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.
Assuntos
Cloretos/química , Modelos Químicos , Rubídio/química , Compostos de Prata/química , Ânions/química , Cátions/química , Simulação de Dinâmica Molecular , TemperaturaRESUMO
Serum thyrotropin (TSH), prolactin (PRL), and growth hormone (GH) levels were measured before and after stimulation with thyrotropin-releasing hormone (TRH) in 10 patients with bulimia, 7 with features of the restricting subtype of anorexia nervosa, and 6 with bulimic subtype of anorexia nervosa. The mean basal levels of TSH, PRL, and GH did not differ among the three groups. A delayed TSH response was found in 86% of the restricting anorectics, 80% of the bulimic anorectics, and 22% of the bulimics. The PRL response was normal in all patients, with no significant difference among the three groups. Elevated basal GH levels were found in 29% of the restricting anorectics, 33% of the bulimic anorectics, and 33% of the bulimics. An abnormal GH increase after TRH stimulation was observed in 50% of the restricting anorectics, 20% of the bulimic anorectics, and 13% of the bulimics. These results suggest that some patients with bulimia, and some with anorexia nervosa, have a hypothalamic dysfunction. These neuroendocrine abnormalities do not appear to be due solely to low weight or to metabolic changes resulting from binge eating and are not associated with depressive symptoms.
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Anorexia Nervosa/fisiopatologia , Bulimia/fisiopatologia , Hormônio do Crescimento/sangue , Prolactina/sangue , Hormônio Liberador de Tireotropina , Tireotropina/sangue , Peso Corporal , Feminino , Humanos , Sistema Hipotálamo-Hipofisário/fisiopatologiaRESUMO
The thyrotropin-releasing hormone (TRH) test and the Dexamethasone Suppression Test (DST) were given to 10 patients who met Research Diagnostic Criteria (RDC) for schizoaffective disorder, manic type, 9 who met the criteria for mania, and 27 who met the criteria for schizophrenia. A blunted thyrotropin (TSH) response to TRH was observed in 3 of the 10 schizoaffective manics, 4 of the 9 manics, and 3 of the 27 schizophrenics. Nonsuppression on the DST was observed in 5 of the 10 schizoaffective manics, 2 of the 9 manics, and 2 of 22 schizophrenics. The schizoaffective manic and the manic patients had similar rates of TSH blunting and DST nonsuppression, and these were significantly higher than the rates in the schizophrenic patients. This difference was not attributable to baseline TSH and cortisol levels or to neuroleptic treatment. It is suggested that patients with RDC schizoaffective mania and mania have more disturbance in the hypothalamic-pituitary adrenal and thyroid axes than patients with schizophrenia.
Assuntos
Transtorno Bipolar/diagnóstico , Dexametasona , Hidrocortisona/sangue , Transtornos Psicóticos/diagnóstico , Esquizofrenia/diagnóstico , Hormônio Liberador de Tireotropina , Tireotropina/sangue , Antipsicóticos/uso terapêutico , Transtorno Bipolar/sangue , Humanos , Escalas de Graduação Psiquiátrica , Transtornos Psicóticos/sangue , Esquizofrenia/sangueRESUMO
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.
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Repetições de Microssatélites , Distrofias Musculares/diagnóstico , Distrofias Musculares/genética , Diagnóstico Pré-Natal/métodos , Encéfalo/patologia , Cromossomos , Feminino , Haplótipos , Humanos , Japão , Masculino , Distrofias Musculares/congênito , Distrofias Musculares/patologia , LinhagemRESUMO
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.
Assuntos
Carcinoma de Ehrlich/metabolismo , Cloraminas/química , Marcação por Isótopo/métodos , Succinimidas/química , Compostos de Tosil/química , alfa-Fetoproteínas/química , alfa-Fetoproteínas/farmacocinética , Animais , Carcinoma de Ehrlich/diagnóstico por imagem , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Lipossomos/química , Lipossomos/farmacocinética , Masculino , Camundongos , Camundongos Endogâmicos , Modelos Moleculares , Cintilografia , Compostos Radiofarmacêuticos/farmacocinética , Sensibilidade e Especificidade , Distribuição TecidualRESUMO
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.
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Encéfalo/fisiologia , DNA/genética , Epilepsia/genética , Poli A/genética , Polirribossomos/fisiologia , RNA Mensageiro/genética , DNA Polimerase Dirigida por RNA/metabolismo , Animais , Sequência de Bases , DNA/biossíntese , DNA/isolamento & purificação , Modelos Animais de Doenças , Suscetibilidade a Doenças , Eletroforese em Gel de Ágar , Cinética , Camundongos , Camundongos Endogâmicos , Camundongos Mutantes , Hibridização de Ácido Nucleico , Poli A/isolamento & purificação , RNA Mensageiro/isolamento & purificaçãoRESUMO
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.
Assuntos
Corpo Estriado/fisiologia , Dopamina/metabolismo , Comportamento Alimentar/fisiologia , Esquema de Reforço , Ácido 3,4-Di-Hidroxifenilacético/metabolismo , Animais , Espaço Extracelular/metabolismo , Feminino , Ácido Homovanílico/metabolismo , Vias Neurais/fisiologia , Ratos , Ratos Wistar , Substância Negra/fisiologiaRESUMO
This study examined by questionnaire the prevalence of binge-eating and bulimia among 220 women at a school of nursing and 236 women at a junior college, all from 18 to 21 years old, in two different areas of Japan. Binge-eating more than once a week was found in 14 (6.5%) of the nursing school students and 21 (9.1%) of the college women. Self-induced vomiting and use of purgatives were found in 19 (8.7%) and 12 (5.5%) of the nursing school students, and 19 (8.1%) and 9 (3.8%) of the college women, respectively. The difference between these two groups was not significant. The prevalence of binge-eating more than once a week, together with self-induced vomiting or purgative use, was 3.6% in the nursing school students, 2.1% in the college women, and 2.9% in the total sample. These women appeared to meet both DSM-III criteria for bulimia and Russell's criteria for bulimia nervosa.
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Bulimia/epidemiologia , Comparação Transcultural , Hiperfagia/epidemiologia , Adolescente , Peso Corporal , Bulimia/etnologia , Estudos Transversais , Feminino , Humanos , Hiperfagia/etnologia , Japão , Reino Unido , Estados UnidosRESUMO
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.
Assuntos
Proteínas de Transporte de Monossacarídeos/genética , Proteínas Musculares , Sequência de Aminoácidos , Animais , Animais Domésticos , Sequência de Bases , Bovinos , DNA Complementar , Transportador de Glucose Tipo 4 , Cabras , Humanos , Mamíferos , Camundongos , Dados de Sequência Molecular , Proteínas de Transporte de Monossacarídeos/biossíntese , Proteínas de Transporte de Monossacarídeos/química , Especificidade de Órgãos , Fragmentos de Peptídeos/química , Reação em Cadeia da Polimerase/métodos , Ratos , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico , Ovinos , SuínosRESUMO
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.
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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.