Crown Graphene Nanomeshes: Highly Stable Chelation-Doped Semiconducting Materials

Graphene nanomeshes (GNM's) formed by the creation of pore superlattices in graphene, are a possible route to graphene-based electronics due to their semiconducting properties, including the emergence of fractional eV band gaps. The utility of GNM's would be markedly increased if a scheme to stably and controllably dope them was developed. In this work, a chemically-motivated approach to GNM doping based on selective pore-perimeter passivation and subsequent ion chelation is proposed. It is shown by first-principles calculations that ion chelation leads to stable doping of the passivated GNM's -- both {\it n}- and {\it p}-doping are achieved within a rigid-band picture. Such chelated or ``crown'' GNM structures are stable, high mobility semiconducting materials possessing intrinsic doping-concentration control; these can serve as building blocks for edge-free graphene nanoelectronics including GNM-based complementary metal oxide semiconductor (CMOS)-type logic switches.Comment: 18 pages, 6 figure

Shear viscosity of the A_1-phase of superfluid 3He

The scattering processes between the quasiparticles in spin- up superfluid with the quasiparticles in spin-down normal fluid are added to the other relevant scattering processes in the Boltzmann collision terms. The Boltzmann equation has been solved exactly for temperatures just below T_c_1. The shear viscosity component of the A_1- phase drops as C_1(1-T/T_c_1)^(1/2). The numerical factor C_1 is in fairly good agreement with the experiments

Governments need better guidance to maximise value for money: the case of Australia’s Pharmaceutical Benefits Advisory Committee

Published online: 27 January 2016In Australia, the Pharmaceutical Benefits Advisory Committee (PBAC) makes recommendations to the Minister for Health on which pharmaceuticals should be subsidised. Given the implications of PBAC recommendations for government finances and population health, PBAC is required to provide advice primarily on the basis of value for money. The aim of this article is twofold: to describe some major limitations of the current PBAC decision-making process in relation to its implicit aim of maximising value for money; and to suggest what might be done toward overcoming these limitations. This should also offer lessons for the many decision-making bodies around the world which are similar to PBAC. The current PBAC decision-making process is limited in two important respects. First, it features the use of an implicit incremental cost-effectiveness ratio (ICER) threshold that may not reflect the opportunity cost of funding a new technology, with unknown and possibly negative consequences for population health. Second, the process does not feature a means of systematically assessing how a technology may be of greater or lesser value in light of factors that are not captured by standard measures of cost effectiveness, but which are nonetheless important, particularly to the Australian community. Overcoming these limitations would mean that PBAC could be more confident of maximising value for money when making funding decisions.Drew Carter, Arlene Vogan, Hossein Haji Ali Afzal

Resistance to Soybean Cyst Nematode: Rhg1

The genes underlying rhg1 lie at a sometimes dominant sometimes co-dominant locus, necessary for resistance to all Hg types of the soybean (Glycine max (L.) Merr.) cyst nematode (Heterodera glycines). Genomic research identified; nucleotide changes within a candidate gene encoding a receptor like kinase (RLK) that were capable of altering root development and thereby part of the resistance to Hg types 0 (race 3); changes in a laccase that are capable of altering cyst development; and genes underlying changes in membrane biology. This set of three genes are subject to co-selection with a modifier locus on another linkage block. Root development is slowed in the resistant seedling and results in end of season yield loss when SCN is not present. However, in the presence of SCN resistant seedling roots grow just as vigorously as the now slower growing parasitized susceptible roots and therefore show little loss to SCN parasitism. In some genotypes but not others the RLK can act alone to confer resistance. Functional paralogs of the three gene cluster have been found on other linkage groups including A1, B1, G, and O and these can be functional in different sources of resistance like G. soja, PI 437654 and PI438489B. At rhg1 the allele differences change the structure, interacting partners and activity of the LRR protein and the laccase. The changes between the alleles result in about 30 other proteins (judged by 2 D gels), 112 metabolites (by FTICRMS) and 8 metabolites (by GCMS) to increase in abundance in roots during SCN infection in the resistant NILs. Understanding the basis of root stunting by resistance alleles will be used to improve methods for developing new nematode resistant soybean cultivars that do not suffer from the yield suppression and low seed germination rates of existing cultivars

Shear viscosity of superfluid 3He-A_1 at low temperatures

The shear viscosity tensor of the A_1-phase of superfluid 3He is calculated at low temperatures and melting pressure, by using Boltzmann equation approach. The two normal and superfluid components take part in elements of the shear viscosity tensor differently. The interaction between normal and Bogoliubov quasiparticles in the collision integrals is considered in the binary, decay and coalescence processes. We show that the elements of the shear viscosities $\eta_{xy}$, $\eta_{xz}$ and $\eta_{zz}$ are proportional to $(T/T_c)^{-2}$. The constant of proportionality is in nearly good agreement with the experimental results of Roobol et al.Comment: 16 pages, some typos were correcte

The receptor like kinase at Rhg1-a/Rfs2 caused pleiotropic resistance to sudden death syndrome and soybean cyst nematode as a transgene by altering signaling responses

Background: Soybean (Glycine max (L. Merr.)) resistance to any population of Heterodera glycines (I.), or Fusarium virguliforme (Akoi, O’Donnell, Homma & Lattanzi) required a functional allele at Rhg1/Rfs2. H. glycines, the soybean cyst nematode (SCN) was an ancient, endemic, pest of soybean whereas F. virguliforme causal agent of sudden death syndrome (SDS), was a recent, regional, pest. This study examined the role of a receptor like kinase (RLK) GmRLK18-1 (gene model Glyma_18_02680 at 1,071 kbp on chromosome 18 of the genome sequence) within the Rhg1/Rfs2 locus in causing resistance to SCN and SDS. Results: A BAC (B73p06) encompassing the Rhg1/Rfs2 locus was sequenced from a resistant cultivar and compared to the sequences of two susceptible cultivars from which 800 SNPs were found. Sequence alignments inferred that the resistance allele was an introgressed region of about 59 kbp at the center of which the GmRLK18-1 was the most polymorphic gene and encoded protein. Analyses were made of plants that were either heterozygous at, or transgenic (and so hemizygous at a new location) with, the resistance allele of GmRLK18-1. Those plants infested with either H. glycines or F. virguliforme showed that the allele for resistance was dominant. In the absence of Rhg4 the GmRLK18-1 was sufficient to confer nearly complete resistance to both root and leaf symptoms of SDS caused by F. virguliforme and provided partial resistance to three different populations of nematodes (mature female cysts were reduced by 30–50%). In the presence of Rhg4 the plants with the transgene were nearly classed as fully resistant to SCN (females reduced to 11% of the susceptible control) as well as SDS. A reduction in the rate of early seedling root development was also shown to be caused by the resistance allele of the GmRLK18-1. Field trials of transgenic plants showed an increase in foliar susceptibility to insect herbivory. Conclusions: The inference that soybean has adapted part of an existing pathogen recognition and defense cascade (H.glycines; SCN and insect herbivory) to a new pathogen (F. virguliforme; SDS) has broad implications for crop improvement. Stable resistance to many pathogens might be achieved by manipulation the genes encoding a small number of pathogen recognition proteins

Effects of biaxial strain on the intervalence‐band absorption spectra of InGaAs/InP systems

The effects of biaxial strain on the intervalence‐band absorption spectra of p‐doped InGaAs/InP bulk layers are investigated. The study is performed by calculating and comparing the absorption coefficients corresponding to the direct transitions between the heavy and light hole bands, between the heavy hole and split‐off bands, and between the split‐off and light hole bands in both the lattice matched and the strained layers. The valence‐band structures of these layers are neither isotropic nor parabolic and hence the k⋅p approach is utilized to calculate the band structures and their corresponding wave functions. The quantities are then invoked in the calculation of the (joint) density of states, the Fermi energy, and the momentum matrix element, which are needed in the evaluation of the intervalence‐band absorption coefficients. These calculated results show that the intervalence‐band absorption coefficients depend on the strain in the layer. The dependence is determined by the bands involved in the intervalence transition, the polarization of the incident light, and the type of the strain (compressive or tensile). © 1995 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70188/2/JAPIAU-77-12-6549-1.pd

Chemotype of damask rose with oleic acid (9 octadecenoic acid) and its antimicrobial effectiveness

Essential oils are natural products that have great antimicrobial potential value against many fungi and bacteria. Rosa damascena Mill. is one of the most important aromatic species of the Rosaceae family from which essential oil and economically valuable products can be obtained. The present study was designed to investigate the major compositions of the essential oil of this plant in Isfahan region of Iran and to identify its antibacterial and antifungal effects against 11 microorganisms causing human diseases and food spoilage. The essential oil was extracted by using the Clevenger apparatus and was analyzed by gas chromatography-mass spectrometry (GC–MS) technique. Its antimicrobial activity was evaluated by well diffusion, minimum inhibitory concentration (MIC) and minimum bactericide concentration (MBC). The results showed that the most important compounds of the essential oil were nonadecane (24.72%), heneicosane (19.325%), oleic acid (17.63%), and citronellol (12.61%). The results also showed that the highest inhibition zone of rose essential oil was against Aspergillus brasiliensis (15.00 ± 0.00 mm) and had a significant effect on Klebsiella pneumoniae (~ 8.00 mm). Also the rose oil had a significant inhibition and lethal effect against Candida albicans (MIC and MBC ~ 125 μg/mL), which is equivalent to the nystatin antibiotic (~ 125 μg/mL). Therefore, the essential oil of Damask rose can be considered as an alternative natural product for the prevention and treatment of fungal diseases in humans and against food spoilage as well