Phase transitions of Dirac electrons in bismuth

The Dirac Hamiltonian, which successfully describes relativistic fermions, applies equally well to electrons in solids with linear energy dispersion, for example, in bismuth and graphene. A characteristic of these materials is that a magnetic field less than 10 tesla suffices to force the Dirac electrons into the lowest Landau level, with resultant strong enhancement of the Coulomb interaction energy. Moreover, the Dirac electrons usually come with multiple flavors or valley degeneracy. These ingredients favor transitions to a collective state with novel quantum properties in large field. By using torque magnetometry, we have investigated the magnetization of bismuth to fields of 31 tesla. We report the observation of sharp field-induced phase transitions into a state with striking magnetic anisotropy, consistent with the breaking of the threefold valley degeneracy.     

Metabolomics technology to phenotype resistance in barley against <Emphasis Type="Italic">Gibberella zeae</Emphasis>

The mechanisms of resistance in barley to fusarium head blight (FHB), caused by Gibberella zeae are complex. Metabolomics technology was explored to phenotype resistance. Spikelets of barley genotypes with contrasting levels of resistance to FHB, mock inoculated or with the pathogen, were extracted with aqueous methanol and the metabolites were analyzed using liquid chromatography and hybrid mass spectrometry. Peaks were de-convoluted using XCMS and annotated using CAMERA and IntelliXtract bioinformatics tools. A t-test, of a total of 1608 purified peaks, selected 626 metabolites with significant treatment effects, of which 161 were identified as resistance related (RR) metabolites. A total of 53 metabolites, that are RR or pathogenicity related (PR), were assigned with putative compound names. These mainly belonged to three metabolic pathways: fatty acid (jasmonic acid, methyl jasmonate, 9,10- dihydro-isojasmonate, linolenic acid, linoleic acid, traumatic acid), phenylpropanoid (p-coumaric acid, caffeyl alcohol, dimethoxy-4-phenylcoumarin, rosmarinic acid, diphyllin, 5-methoxypodophyllotoxin) and flavonoid (naringenin, catechin, quercetin, and alpinumisoflavone). A few PR/RR metabolites significantly reduced mycelial growth of G. zeae in vitro.     

An assay for circulating antibodies to a major etiologic virus of human non-A, non-B hepatitis

A specific assay has been developed for a blood-borne non-A, non-B hepatitis (NANBH) virus in which a polypeptide synthesized in recombinant yeast clones of the hepatitis C virus (HCV) is used to capture circulating viral antibodies. HCV antibodies were detected in six of seven human sera that were shown previously to transmit NANBH to chimpanzees. Assays of ten blood transfusions in the United States that resulted in chronic NANBH revealed that there was at least one positive blood donor in nine of these cases and that all ten recipients seroconverted during their illnesses. About 80 percent of chronic, post-transfusion NANBH (PT-NANBH) patients from Italy and Japan had circulating HCV antibody; a much lower frequency (15 percent) was observed in acute, resolving infections. In addition, 58 percent of NANBH patients from the United States with no identifiable source of parenteral exposure to the virus were also positive for HCV antibody. These data indicate that HCV is a major cause of NANBH throughout the world.     

Removal of heavy metals in aqueous solution using Antarctic krill chitosan/hydroxyapatite composite

Discarded Antarctic krill shells can be used to prepare chitosan and adsorption materials in an attempt to save resource and protect environment. The optimal conditions of composite materials preparation were as follows: mass ratio of CS and HA was 2:1 at 40 °C, pH 10–10.5, volume ratio of chitosan and Ca(NO₃)₂ was 2:1 over a period of 1 day. Under these conditions, the Cr (VI) removal rate was about 75±8 %. SEM, TEM, XRD, FTIR, DT-TGA analysis indicated that CS/HA composite was made up of CS and HA and it possessed good mechanical strength and thermal stability. The ability to remove Cd (II), Cr (III) and Cu (II) in aqueous was high, and the optimal conditions were as follows: a contact time of 60 min at 35 °C and pH 6–7. The removal rates of all three heavy metals were above 90 %.     

Yellow tailflower mild mottle virus and Pelargonium zonate spot virus co‐infect a wild plant of red‐striped tailflower in Australia

Isolates of an Australian indigenous virus, Yellow tailflower mild mottle virus (YTMMV‐Kalbarri), and an exotic virus, Pelargonium zonate spot virus (PZSV‐SW13), are described from Anthocercis ilicifolia subsp. ilicifolia (red‐striped tailflower, family Solanaceae), a species endemic to Western Australia. This is the first report of either virus from this plant species. The complete genome sequences of YTMMV‐Kalbarri and of PZSV‐SW13 were obtained. YTMMV‐Kalbarri shared 97% nucleotide pairwise identity with the sequence of the type isolate YTMMV‐Cervantes. The sequence PZSV‐SW13 shared greatest sequence identity with the partial sequence of an Australian isolate of PZSV, also from a wild plant, and with a sunflower‐derived isolate of PZSV from Argentina. An experimental host range study was done of YTMMV‐Kalbarri using cultivated and wild solanaceous and non‐solanaceous plants. Most solanaceous plants became systemically infected, with symptoms of systemic infection ranging from symptomless to whole plant necrosis. Based on these studies, it is suggested that YTMMV has the potential to become a pathogen of commercial species of Solanaceae. This study provides further evidence that PZSV is present in wild plants in Australia, in this case an indigenous host species, and possible routes by which it invaded Australia are discussed.     

Gelam honey inhibits lipopolysaccharide-induced endotoxemia in rats through the induction of heme oxygenase-1 and the inhibition of cytokines, nitric oxide, and high-mobility group protein B1

Malaysian Gelam honey has anti-inflammatory and antibacterial properties, a high antioxidant capacity, and free radical-scavenging activity. Lipopolysaccharide (LPS) stimulates immune cells to sequentially release early pro- and anti-inflammatory cytokines and induces the synthesis of several related enzymes. The aim of this study was to investigate the effect of the intravenous injection of honey in rats with LPS-induced endotoxemia. The results showed that after 4h of treatment, honey reduced cytokine (tumor necrosis factor-α, interleukins 1β, and 10) and NO levels and increased heme oxygenase-1 levels. After 24h, a decrease in cytokines and NO and an increase in HO-1 were seen in all groups, whereas a reduction in HMGB1 occurred only in the honey-treated groups. These results support the further examination of honey as a natural compound for the treatment of a wide range of inflammatory diseases.