Preparation and electrical properties of Li–Si–Al–O–N ceramics

AbstractCeramic samples were synthesized by hot pressing mixtures of Li3N, Si3N4, AlN, Al2O3, and Li2CO3 with nominal compositions of LiSi2−xAlxOxN3−x (x=0–0.75) at 20MPa and 1773–2073K in a N2 atmosphere of 0.10MPa. The samples prepared with nominal compositions, x=0.25 and 0.50, showed electronic conductivities of 2.2 and 4.2Sm−1 at room temperature with activation energies of 3.8 and 3.9kJmol−1, respectively. Electronic conductive parts were detected in the sample of x=0.50 by conductive atomic force microscopy (AFM). In this sample, a glassy thin layer, having a Si/Al atomic ratio of 3.8, was observed between the grains of LiSi2−xAlxOxN3−x solid solution by high-resolution transmission electron microscopy (HRTEM). It was expected that the glassy phase of grain boundaries is an electronic conductive pathway besides the conductive parts observed by AFM

Effects of fruit skin and water temperature during soaking before germination on the emergence rates of common buckwheat

The studies focused effects of the presence of fruit skin (hull or pericarp) and water temperature during water soaking before germination on the emergence rates of common buckwheat (Fagophyrum esculentum Moench) after seeding. We aimed to understand the mechanisms underlying the poor emergence rates that have been observed after water flooding before germination. Shinano No.1 was exposed to water soaking treatments at temperatures of 10,15,20, or 25℃ for 3 days. After soaking, the seeds were grown at 20℃, and the percentages of emerged seedlings were investigated 7 days after seeding. Dehulled seeds and normal seeds were soaked for 4 days at 25℃, and the contents of dissolved oxygen were measured in the water. The emergence rates of normal intact seeds (fruits)decreased significantly (p＜0.01)with an increase in soaking water temperature before germination. The emergence rates of dehulled seeds improved after removing the fruit skin, and it reached 70%,even at 25℃.Soaking treatment for 96 h at 25℃ decreased the emergence rates of normal seeds and dehulled seeds. The emergence rate of normal seeds was significantly lower than that of dehulled seeds (p＜0.001). Moreover, there was no difference in the emergence rates of dehulled seeds between plots with or without daily water replacement. The contents of dissolved oxygen in the water at 25℃ did not differ between normal seeds and dehulled seeds after 50h. These results suggested that high temperatures affected embryo viability and that the relative mechanical resistance of the fruit skin on the embryo directly affected the seed emergence rate.Article信州大学農学部AFC報告 13: 113-118 (2015)departmental bulletin pape

Mechanisms of Neuronal Death in Synucleinopathy

α-synuclein is a key molecule in the pathogenesis of synucleinopathy including Parkinson's disease and multiple system atrophy. In this mini-review, we mainly focus on recent data obtained from cellular models of synucleinopathy and discuss the possible mechanisms of neurodegeneration. Recent progress suggests that the aggregate formation of α-synuclein is cytoprotective and that its precursor oligomer (protofibril) may be cytotoxic. The catechol-derived quinones are the candidate molecules that facilitate the oligomer formation of α-synuclein. Furthermore, the cellular membranes are shown to be the primary targets injured by mutant α-synucleins, and the mitochondrial dysfunction seems to be an initial step in the neuronal death

Morphogenesis of the Inner Ear at Different Stages of Normal Human Development

This study examined the external morphology and morphometry of the human embryonic inner ear membranous labyrinth and documented its three-dimensional position in the developing embryo using phase-contrast X-ray computed tomography and magnetic resonance imaging. A total of 27 samples between Carnegie stage (CS) 17 and the postembryonic phase during trimester 1 (approximately 6-10 weeks after fertilization) were included. The otic vesicle elongated along the dorso-ventral axis and differentiated into the end lymphatic appendage and cochlear duct (CD) at CS 17. The spiral course of the CD began at CS18, with anterior and posterior semicircular ducts (SDs) forming prominent circles with a common crus. The spiral course of the CD comprised more than two turns at the postembryonic phase, at which time the height of the CD was evident. A linear increase was observed in the length of anterior, posterior, and lateral SDs, in that order, and the length of the CD increased exponentially over the course of development. Bending in the medial direction was observed between the cochlear and vestibular parts from the latero-caudal view, with the angle decreasing during development. The position of the inner ear was stable throughout the period of observation on the lateral to ventral side of the rhombencephalon, caudal to the pontine flexure, and adjacent to the auditory ganglia. The plane of the lateral semicircular canal was approximately 8.0°-14.6° with respect to the cranial caudal (z-)axis, indicating that the orientation of the inner ear changes during growth to adulthood

Transient Increase in Zn2+ in Hippocampal CA1 Pyramidal Neurons Causes Reversible Memory Deficit

The translocation of synaptic Zn2+ to the cytosolic compartment has been studied to understand Zn2+ neurotoxicity in neurological diseases. However, it is unknown whether the moderate increase in Zn2+ in the cytosolic compartment affects memory processing in the hippocampus. In the present study, the moderate increase in cytosolic Zn2+ in the hippocampus was induced with clioquinol (CQ), a zinc ionophore. Zn2+ delivery by Zn-CQ transiently attenuated CA1 long-term potentiation (LTP) in hippocampal slices prepared 2 h after i.p. injection of Zn-CQ into rats, when intracellular Zn2+ levels was transiently increased in the CA1 pyramidal cell layer, followed by object recognition memory deficit. Object recognition memory was transiently impaired 30 min after injection of ZnCl2 into the CA1, but not after injection into the dentate gyrus that did not significantly increase intracellular Zn2+ in the granule cell layer of the dentate gyrus. Object recognition memory deficit may be linked to the preferential increase in Zn2+ and/or the preferential vulnerability to Zn2+ in CA1 pyramidal neurons. In the case of the cytosolic increase in endogenous Zn2+ in the CA1 induced by 100 mM KCl, furthermore, object recognition memory was also transiently impaired, while ameliorated by co-injection of CaEDTA to block the increase in cytosolic Zn2+. The present study indicates that the transient increase in cytosolic Zn2+ in CA1 pyramidal neurons reversibly impairs object recognition memory

Decreased ADP-Ribosyl Cyclase Activity in Peripheral Blood Mononuclear Cells from Diabetic Patients with Nephropathy

Aims/hypothesis. ADP-ribosyl-cyclase activity (ADPRCA) of CD38 and other ectoenzymes mainly generate cyclic adenosine 5’diphosphate-(ADP-) ribose (cADPR) as a second messenger in various mammalian cells, including pancreatic beta cells and peripheral blood mononuclear cells (PBMCs). Since PBMCs contribute to the pathogenesis of diabetic nephropathy, ADPRCA of PBMCs could serve as a clinical prognostic marker for diabetic nephropathy. This study aimed to investigate the connection between ADPRCA in PBMCs and diabetic complications. Methods. PBMCs from 60 diabetic patients (10 for type 1 and 50 for type 2) and 15 nondiabetic controls were fluorometrically measured for ADPRCA based on the conversion of nicotinamide guanine dinucleotide (NGD+) into cyclic GDP-ribose. Results. ADPRCA negatively correlated with the level of HbA1c (P = .040, R2 = .073), although ADPRCA showed no significant correlation with gender, age, BMI, blood pressure, level of fasting plasma glucose and lipid levels, as well as type, duration, or medication of diabetes. Interestingly, patients with nephropathy, but not other complications, presented significantly lower ADPRCA than those without nephropathy (P = .0198) and diabetes (P = .0332). ANCOVA analysis adjusted for HbA1c showed no significant correlation between ADPRCA and nephropathy. However, logistic regression analyses revealed that determinants for nephropathy were systolic blood pressure and ADPRCA, not HbA1c. Conclusion/interpretation. Decreased ADPRCA significantly correlated with diabetic nephropathy. ADPRCA in PBMCs would be an important marker associated with diabetic nephropathy

Ca1_xLixAl1_xSi1+xN3：Eu2+ solid solutions as broadband,color-tunable and thermally robust red phosphors for superior color rendition white light-emitting diodes

日前，我院解荣军教授及其合作者在半导体照明用稀土掺杂氮化物发光材料研究上取得突破性进展。稀土发光材料是半导体照明技术中最为关键的核心材料之一，决定了半导体照明器件的发光效率、显色指数、色温和可靠性等重要性能。解荣军教授及其合作者在长期研究氮化物发光材料及半导体照明器件的工作基础上，巧妙地通过发光材料的晶体结构局域调控和能带工程设计，研究和开发了具有宽谱发射、光谱可控的高可靠性氮化物固溶体红色发光材料，成功解决了半导体照明技术中的重要科学问题和关键技术难题。该论文的第一作者为中国计量大学光学与电子技术学院的王乐副教授，解荣军和王乐为共同通讯作者，厦门大学为第一通讯单位。合作单位还有日本国立材料研究所、重庆邮电大学和台湾大学。由于文章具有创新性和重要性，被选为当期封面文章。【Abstract】Color rendition, luminous efficacy and reliability are three key technical parameters for white light-emitting diodes (wLEDs) that are dominantly determined by down-conversion phosphors. However, there is usually an inevitable trade-off between color rendition and luminescence efficacy because the spectrum of red phosphor (that is, spectral broadness and position) cannot satisfy them simultaneously. In this work, we report a very promising red phosphor that can minimize the aforementioned trade-off via structure and band-gap engineering, achieved by introducing isostructural LiSi2N3 into CaAlSiN3:Eu2+. The solid solution phosphors show both substantial spectra broadening (88→117 nm) and blueshift (652→642 nm), along with a significant improvement in thermal quenching (only a 6% reduction at 150 °C), which are strongly associated with electronic and crystal structure evolutions. The broadband and robust red phosphor thus enables fabrication of super-high color rendering wLEDs (Ra=95 and R9=96) concurrently with the maintenance of a high-luminous efficacy (101 lm W−1), validating its superiority in high-performance solid state lightings over currently used red phosphors.We are grateful for the financial support from the JSPS KAKENHI (No. 23560811), the National Natural Science Foundation of China (Nos. 51272259, 61575182, 5157223 and 51561135015), the Natural Science Foundation of Zhejiang Province (No. Y16F050012) and the Taiwan Science and Technology Authority (No. ‘MOST’ 104-2113-M-002-012-MY3 and No. 104-2119-M-002-027-MY3)