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Freestanding nanocrystalline β-Ga2O3 particles with an average grain size of 14 nm prepared by chemical method was investigated by angle-dispersive synchrotron x-ray diffraction in diamond-anvil cell up to 64.9 GPa at ambient temperature. The evolution of x-ray diffraction patterns indicated that nanocrystalline monoclinic β-Ga2O3 underwent a phase transition to rhombohedral α-Ga2O3. It was found that β- to α-Ga2O3 transition began at about 13.6–16.4 GPa, and extended up to 39.2 GPa. At the highest pressure used, only α-Ga2O3 was present, which remained after pressure release. A Birch–Murnaghan fit to the P-V data yielded a zero-pressure bulk modulus at fixed B0′=4: B0=228(9) GPa and B0=333(19) GPa for β-Ga2O3 and α-Ga2O3 phases, respectively. We compared our results with bulk β-Ga2O3, and concluded that the phase-transition pressure and bulk modulus of nanocrystalline β-Ga2O3 are higher than those of bulk counterpart. [ABSTRACT FROM AUTHOR]

X-ray powder diffraction studies of Sm2(Fe(1-x)Ga(x))17 (x = 0 to 0.5) compounds and their nitrides reveal a Th2Zn17-type structure. Replacing Fe by Ga causes Curie temperature to increase, while addition of nitrogen results in uniaxial anisotropy. Increase in Ga concentration reduces the anisotropic field of the compound.

Offers information on a study which examined the magnetic properties of Sm[sub2](Fe[sub1-x]Ga[subx])[sub17] compounds and their nitrides. Review of related literature; Methodology; Results and discussion.

Irregularly shaped (IRS) particles widely exist in many engineering and industrial fields. The macro physical and mechanical properties of the particle system are governed by the interaction between the particles in the system. The interaction between IRS particles is more complicated because of their complex geometric shape with extremely irregular and co-existed concave and convex surfaces. These particles may interlock each other, making the sliding and friction of IRS particles more complex than that of particles with regular shape. In order to study the interaction of IRS particles more efficiently, a refined method of constructing discrete element model based on computed tomography scanning of IRS particles is proposed. Three parameters were introduced to control the accuracy and the number of packing spheres. Subsequently, the inertia tensor of the IRS particle model was optimized. Finally, laboratory and numerical open bottom cylinder tests were carried out to verify the refined modeling method. The influence of particle shape, particle position, and mesoscopic friction coefficient on the interaction of particles was also simulated. It is noteworthy that with the increase of mesoscopic friction coefficient, the fluidity of IRS particle assembly decreases, and intermittent limit equilibrium state may appear. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Dense (1− x)Ca(Mg1/3Ta2/3)O3/ xCaTiO3 ceramics (0.1≤ x≤0.9) were prepared by a solid-state reaction process. The crystal structures and microstructures were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Single-phase solid solutions were obtained in the entire composition range. Long-range 1:2 ordering of B-site cations and oxygen octahedra tilting lead to the monoclinic symmetry with space group P21/ c for x=0.1. For x above 0.1, the long-range ordering was destroyed and the crystal structure became the orthorhombic with space group Pbnm. The microwave dielectric properties showed a strong dependence on the composition and microstructure. The dielectric constant and temperature coefficient of resonant frequency increased nonlinearly as the CaTiO3 content increased while the Qf values decreased approximately linearly. Good combination of microwave dielectric properties was obtained at x=0.45, where ℇr=45.1, Qf=34 800 GHz, and τf=17.4 ppm/°C. [ABSTRACT FROM AUTHOR]

The dielectric characteristics of BaBi2Nb2O9, BaBi4Ti4O15, BaBi8Ti7O27, and La-substituted SrBi4Ti4O4 were investigated to discuss their ferroelectric phase transition and relaxor behaviors. BaBi2Nb2O9 showed typical relaxor behaviors, and a shift of Tm with increasing frequency was observed in BaBi4Ti4O15 and SrBi4− xLa xTi4O15 ( x=0.8, 1.0) but they underwent a real paraelectric–ferroelectric phase transition on zero-field cooling, while BaBi8Ti7O27 showed a normal ferroelectric nature. The reduced concentration and weakened coupling of the dipoles related to A-site bismuth are believed to be responsible for the appearance of short-range electric ordering and the relaxor behaviors in these bismuth layer-structured compounds. [ABSTRACT FROM AUTHOR]

Cryopreservation of boar semen causes oxidative damage to sperm. Semen needs to hold at 17°C for a period of time prior to cryopreservation. Holding time allows interaction between sperm and seminal plasma to improve sperm quality after thawing. The aim of this study was to investigate the effect of prolonging holding time of collected boar semen on sperm antioxidant capacity and frozen-thawed quality. Collected semen was held at 17°C for 3 hours and 24 hours respectively. A part of the semen was irradiated with ultraviolet (0.6 J/cm²), and the remaining semen was cryopreserved. The semen samples were evaluated sperm motility, viability, mitochondrial membrane potential (MMP) and acrosome integrity. Besids, the sperm malondialdehyde (MDA) level was measured after being irradiated with ultraviolet. The results showed that the sperm motility, viability, and MMP of ultraviolet irradiated or frozen-thawed semen held at 17°C for 24 hours were significantly higher (P < 0.05) than those of 3 hours holding time. The ultraviolet irradiated sperm MDA level of 24 hours holding time was significantly lower (P < 0.05) than that of 3 hours. In summary, boar semen holding at 17°C for 24 hours could effectively reduce ultraviolet irradiated sperm MDA level and the oxidative damage to sperm, and improve the sperm quality of frozen-thawed semen. [ABSTRACT FROM AUTHOR]

Sperm are vulnerable to oxidative damage during the preservation of boar semen. Light is one of the causes of the damage. Therefore, collected semen should be preserved in the dark to reduce the oxidative damage to sperm. The aim of this study was to evaluate the effect of ultraviolet (UV) irradiation on boar sperm oxidative damage and sperm quality. Boar semen was held at 17°C for 0 hour and 3 hours, respectively, and irradiated with different intensities of ultraviolet (0, 0.2, 0.4, 0.6, 0.8, 1.0 J/cm²). Sperm quality was determined by assessing the sperm motility, viability, mitochondrial membrane potential (MMP), acrosome integrity and reactive oxygen species (ROS) level. The results showed that only ROS level of UV irradiated sperm held at 17°C for 3 hours was significantly lower than that of 0 hour holding time. Increasing the intensity of UV irradiation significantly reduced the total motility, progress motility, mitochondrial membrane potential and viability of sperm, and increased the ROS level. The UV intensity of 0.6 J/cm² irradiation could reduce 50% sperm total motility, but it had no effect on the sperm acrosome integrity. In the conclusion, UV irradiation caused oxidative damage to sperm and reduced sperm quality. There's dose-effect relation within UV irradiation. However, boar semen held at 17°C for 3 hours could effectively reduce the oxidative damage to sperm. [ABSTRACT FROM AUTHOR]

Microcavity organic light-emitting diodes (OLEDs) with ITO distributed Bragg reflectors (DBRs) were proposed. For the 6.5-period DBR electrode, the Bragg reflectivity and sheet resistance of 92.3% and 30 Ω/ square were obtained. In addition, the full width at half maximum of the electroluminescence spectra of the microcavity OLED was <7 nm and the enhancement of the optical intensity was 4.6 times higher in amplitude than that of the non-cavity OLED. [ABSTRACT FROM AUTHOR]

The dielectric characteristics of BaBi2Nb2O9, BaBi4Ti4O15, BaBi8Ti7O27, and La-substituted SrBi4Ti4O4 were investigated to discuss their ferroelectric phase transition and relaxor behaviors. BaBi2Nb2O9 showed typical relaxor behaviors, and a shift of Tm with increasing frequency was observed in BaBi4Ti4O15 and SrBi4− xLa xTi4O15 ( x=0.8, 1.0) but they underwent a real paraelectric–ferroelectric phase transition on zero-field cooling, while BaBi8Ti7O27 showed a normal ferroelectric nature. The reduced concentration and weakened coupling of the dipoles related to A-site bismuth are believed to be responsible for the appearance of short-range electric ordering and the relaxor behaviors in these bismuth layer-structured compounds. [ABSTRACT FROM AUTHOR]

Mineral elements in barley (Hordeum vulgare) play an important physiological role in global human health. In this study, quantitative trait loci (QTLs) for concentration of nine mineral elements in barley grain and grass powder were detected in a population of 193 recombinant inbred lines of the barley cross Ziguangmangluoerling x Schooner and the parents. We observed large genetic variation contributing to element concentrations in both grains and grass powder. The mean K, Ca, and Fe concentrations in grass powder were 6.67, 12.00, and 4.58 times that of regenerating barley grains. In grains, 17 QTLs that accounted for 6.36-64.08% of the phenotypic variation in Zn, Mg, Ca, K, Na, Mn, Fe, and P concentrations were identified. In grass powder, seven QTLs were identified; these accounted for 6.03-21.86% of the variation in Ca, Zn, Mg, K, Fe, and Cu concentrations. These QTLs affecting elements in grain and grass powder are so far unreported in barley. To our knowledge, QTLs with pleiotropic effects for three elements were also identified for the first time in barley. The qK1/qMg1/qCa1 region between markers Bmag0211 and GBMS0014 on chromosome 1H was shown to have large additive effects for Mg, Ca, and K concentrations in grains. These additive effects indicated that the high element (Mg, Ca, Zn, Mn, and K) alleles were contributed by Ziguangmangluoerling. These results will further our understanding of the genetic basis of mineral elements and help us develop markers linked with mineral elements for marker-assisted selection breeding in barley.

An F3 population consisting of 117 F2:3 families derived from a cross between two varieties of rice, Gongmi No. 3 and Diantun 502, with a large difference in their resistant starch and total alkaloid content, was used for quantitative trait locus (QTL) mapping. Two QTLs of resistant starch for rice (qRS7-1, qRS7-2) were identified in a linkage group on chromosome 7, which could explain phenotypic variance from 7.6 to 17.3%, due to additive effects for resistant starch from Gongmi No. 3 or over-dominance effects for qRS7-2 of the marker interval (RM3404-RM478) on chromosome 7 from Gongmi No. 3, accounting for 13.8-17.3% of the phenotypic variance. Two QTLs of total alkaloids for brown rice (qALb7-1, qALb7-2) were identified in the same linkage group, which could explain phenotypic variance from 7.7 and 19.3%, respectively, due to dominance or over-dominance effects for total alkaloids on chromosome 7 from Diantun 502. To our knowledge, these are the first QTLs to be identified, which are related to resistant starch and total alkaloid content in rice. These results are beneficial for understanding the genetic basis of, as well as for developing markers linked with, resistant starch and total alkaloids of functional components for marker-assisted selection breeding in rice., Competing Interests: The authors declare no conflict of interest.

The purpose of the present investigation was to determine the responses of human brain to transcutaneous electric nerve stimulation (TENS) at different frequencies by functional magnetic resonance imaging (fMRI) examinations covering the whole brain of eleven healthy volunteers. Each subject received TENS at acupoints ST36 and SP6 of the left leg at the frequencies of 2 and 100 Hz. Frequency-specific responses were found in motor-related areas, thalamus, limbic system and associated cortex to stimulation of the two frequencies, while the primary somatosensory areas were activated by both. Therefore, it appears that 2 and 100 Hz TENS act through different neuro-pathways in the central nervous system.