Identification of quantitative trait loci for mineral elements in grains and grass powder of barley

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.

Identification of QTLs for resistant starch and total alkaloid content in brown and polished rice

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.

Adsorption behavior of dinucleotides on bare and ru-modified glassy carbon electrode surfaces

The interactive behavior of flavin adenine dinucleotide (FAD) with a bare glassy carbon electrode (GCE) and a Ru-modified GCE was investigated. The reduction of FAD at a GCE/ruthenium-modified GCE surface is a quasi-reversible, surface-controlled process, and our data implied that the attachment of FAD onto the surface is caused by nonspecific adsorption instead of covalent linkage, in which the adenine ring of FAD adopts a flat orientation on the GCE surface in neutral and dilute solutions in order to maximize the pi-pi stacking with the carbon surface and reorients to a perpendicular orientation as the surface gets more crowded. FAD desorption during the exchange with nicotinamide adenine dinucleotide (NAD+) is one order of magnitude slower than desorption in the absence of NAD+, which indicates a strong interaction between FAD and NAD+. General knowledge of the interactive behavior of NAD+ on a FAD-adsorbed GCE provides useful information for the design of a modified electrode surface for the generation of NADH from NAD+.

New class of plastic bulk metallic glass

An intrinsic plastic Cu(45)Zr(46)Al(7)Ti(2) bulk metallic glass (BMG) with high strength and superior compressive plastic strain of up to 32.5% was successfully fabricated by copper mold casting. The superior compressive plastic strain was attributed to a large amount of randomly distributed free volume induced by Ti minor alloying, which results in extensive shear band formation, branching, interaction and self-healing of minor cracks. The mechanism of plasticity presented here suggests that the creation of a large amount of free volume in BMGs by minor alloying or other methods might be a promising new way to enhance the plasticity of BMGs.

Wurtzite-to-Rocksalt Structural Transformation in Nanocrystalline CoO

Hexagonal CoO nanocrystals are coarsened under hydrothermal conditions to investigate the effect of particle size on phase transformation and stability property. Structural stability and phase transformation of the hexagonal CoO phase have been investigated by X-ray powder diffraction with Rietveld refinement, transmission electron microscopy, X-ray absorption fine structure, and differential scanning calorimeter. It is found that the hexagonal CoO phase is a metastable phase, which increases its grain size from 50 to 250 nm for refluxing times from 1 to 6 h at 200 degrees C. After 12 h, cubic-structured CoO grains with an average grain size of 20 nm are observed, which spread around big hexagonal CoO grains. After about 24 h, only the cubic CoO phase with an average grain size of 25 nm is detected. The onset temperature of hexagonal-to-cubic phase transformation in CoO is estimated to be 378 degrees C by DSC, using a heating rate of 20 deg/min. The results obtained indicate that the hexagonal-to-cubic phase transformation in nanocrystalline CoO is by nucleation and growth mechanism, starting from the surface to the center of the hexagonal grains.

[Analysis of gene expression profiles in heart tissues from two breeds of pigs]

To study the expression profiles in the heart tissues of domestic pigs,five un-normalized cDNA libraries from Danish adult female Landrace heart, biceps femoris, aorta, left ventricle tissues and Chinese adult female Erhualian heart tissue were constructed. Totally 35 180 expressed sequence tags (ESTs) were randomly sequenced. Using functional clustering and statistic methods, three gene clusters and 47 genes highly expressed in Landrace heart tissue were found. These genes are corresponding to the chaperone activity, motor activity and physiology process, implying the functional importance of the protection and movement process in heart. Between the two pig breeds, most of the differentially expressed genes are related with energy metabolism and catalytic activity, of which the majority are highly expressed in Landrace. The results indicate that the physiological activities of Landrace heart are more active and effective than Erhualian heart.

Striatal neuronal loss or dysfunction and choline rise in children with attention-deficit hyperactivity disorder: a 1H-magnetic resonance spectroscopy study

Twelve previously untreated boys suffering from attention-deficit hyperactivity disorder (ADHD) were investigated by using proton magnetic resonance spectroscopy (1H MRS) before and after one dose (10 mg) of methylphenidate. Pre- and post-methylphenidate spectra were acquired bilaterally in the globus pallidus. Peaks of N-acetylaspartate (NAA), choline (Cho), myo-inositol, glutamate and creatine (Cr) were measured and the ratios of the peaks were calculated and compared with data from ten matched controls. In children having ADHD, NAA/Cr ratio decreased significantly in the bilateral striatum while Cho/Cr ratio showed a mild unilateral increase. One oral dose of methylphenidate did not affect the ratios significantly. These findings suggest that the striatum was bilaterally involved in pediatric ADHD patients. Approximately 20-25% of neurons may have died or may be severely dysfunctional. There seems to be a mild hyperactivity of the cholinergic system.

[Frequency-specific responses of human brain to peripheral transcutaneous electric nerve stimulation: a functional magnetic resonance imaging study]

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.