Stacking disorder in silicon carbide supported cobalt crystallites : an X-ray diffraction, electron diffraction and high resolution electron microscopy study

Supported cobalt Fischer–Tropsch catalysts are characteristically nanoparticulate and the reduced SiC supported catalyst was found to contain both HCP and FCC polymorphs. This is reflected in the powder XRD patterns and generally there is a poor fit between the experimental and calculated diffractograms. This was ascribed to small crystallite sizes and the occurrence of disorder, manifested as peak broadening and peak shifts. Selected area electron diffraction data of suitably oriented cobalt catalyst grains on silicon carbide supports show non-periodic disorder in the zone axis orientations that contain the common (001) (HCP) and (111) (FCC) reciprocal lattice planes. Both FCC and HCP polymorphs are present in the same grains and these show disorder mainly in the HCP component. The disorder is further examined using high angle annular dark field (HAADF) scanning transmission electron microscopy at atomic resolution and the stacking sequences elucidated. Random sequences of mainly FCC are interrupted by HCP sequences and twin surfaces with reverse stacking sequences are also present. This study highlights the presence of significant disorder in cobalt catalyst grains confirmed by HAADF microscopy.We acknowledge Sasol for funding.http://www.rsc.org/journals-books-databases/about-journals/PCCP2017-11-30hb2016Chemistr

Human gene mutations. Gene symbol: HFE. Disease: hereditary haemochromatosis.

[No abstract available]Articl

Near infrared spectroscopy to predict internal quality of mangoes

Consumers have high demands regarding the quality of mangoes. Fruits with internal defects lead to disappointment after sale and a decrease in purchases. The aim of this study is to predict internal quality of mangoes using non-destructive near infrared (NIR) measurements. The internal browning was measured from 3000 mangoes grown and harvested in Brazil, transported to the Netherlands and ripened. The results show a good correlation between the occurrence of internal defects and the loss of fruit firmness and increase in fruit flesh colour. NIR measurements allow sorting of mangoes for internal defects in a non-destructive manner, to ensure only mangoes without internal defects reach the consumers. This not only prevents consumer disappointment but also contributes to less waste and a more sustainable mango chain

Near infrared spectroscopy to predict internal quality of mangoes

Consumers have high demands regarding the quality of mangoes. Fruits with internal defects lead to disappointment after sale and a decrease in purchases. The aim of this study is to predict internal quality of mangoes using non-destructive near infrared (NIR) measurements. The internal browning was measured from 3000 mangoes grown and harvested in Brazil, transported to the Netherlands and ripened. The results show a good correlation between the occurrence of internal defects and the loss of fruit firmness and increase in fruit flesh colour. NIR measurements allow sorting of mangoes for internal defects in a non-destructive manner, to ensure only mangoes without internal defects reach the consumers. This not only prevents consumer disappointment but also contributes to less waste and a more sustainable mango chain

Characterization of the South African HIV type 1 subtype C complete 5′ long terminal repeat, nef, and regulatory genes

Human immunodeficiency virus type 1 (HIV-1) subtype C has become the major etiological agent in the global and especially African epidemic. To gain better understanding of the genetic diversity and rapid transmission of HIV-1 subtype C, we have characterized the complete 5′ long terminal repeat (LTR) region along with the regulatory genestat andrev as well as the accessory genenef of 14 South African HIV-1 subtype C isolates. Phylogenetic analysis revealed a subtype C 5′ LTR cluster, as well as subclustering of ournef sequences with various subtype C strains separate from the India and China subclusters. At least 3 NF-κB sites were present in the 5′ LTR of most isolates and 13 isolates had the subtype C-specific Rev truncation. Some length variation in exon 2 and the absence of a critical cysteine were found in Tat. Residue variation in the myris-toylation signal and motifs involved in CD4 and MHC-I downregulation was recorded in our nef gene sequences.Articl

Exploiting host immunity and parasite genomics to develop a robust sub-unit vaccine against East Coast fever in cattle - Where are we?

Theileria parva, a tick-borne api-complexan protozoan parasite, causes East Coast fever (ECF) in cattle. Control of the disease by improved vaccination is believed to provide a sustainable solution. Class I MHC-restricted CD8+ cytotoxic T lymphocytes (CTL) directed at schizontinfected cells constitute the effector immune mechanism against ECF in cattle recovering from a single or multiple infection(s). Schizont antigens recognised by CTL are therefore prime vaccine candidates. We describe a rational approach used to identify 8 CTL target antigens as vaccine candidates. The genes encoding the target antigens have been engineered in plasmid DNA and viral vectors for evaluating their immunogenicity and efficacy in cattle. In a preliminary trial, five of the candidate vaccines demonstrated the capacity to induce CTL responses that correlated with survival and reduced disease severity following a lethal parasite challenge