It is important to study optimism as it is negatively correlated with anxiety and depressive and positively correlated with quality of life in cancer patients. This study translated and investigated the psychometric properties of the Malay version of the Life Orientation Test-Revised (LOT-R) among Malaysian cancer patients. The validated Malay version of the LOT-R will be used for assessing level of optimism among Malaysian cancer patients in future studies and determine factors associated with it in order to design effective psychosocial intervention which will enhance level of optimism in cancer patients. Concurrent translation and back translation of original English version of the LOT-R to Malay was performed and the Malay version was administered to 195 cancer patients of different cancer diagnoses at baseline assessment and repeated 2 months later at follow up. Reliability was assessed with internal consistency (Cronbach’s α) and test-retest reliability (intraclass correlation coefficient), validity was assessed with face, content, convergent, and discriminant validities. Construct validity was examined with exploratory factor analysis. Two third of the participants (n = 129/195; 66%) were of middle age, three forth were females (n = 142/195; 72.8%) and eight tenth were Malays (n = 160/195; 82.1%). The LOT-R (Malay) total score (Cronbach’s α = 0.58; ICC = 0.62) and its domains (Cronbach’s α [Optimism) = 0.60; Cronbach’s α[Pessimism) = 0.42; ICC[Optimism] = 0.61; ICC[Pessimism] = 0.59) demonstrated questionable internal consistencies but acceptable test-retest reliability. Convergent and discriminant validities were achieved by the LOT-R (Malay). Construct validity was also demonstrated by the LOT-R (Malay) as exploratory factor analysis showed that all the items had factor loadings > 0.4.
The LOT-R (Malay) has acceptable psychometric properties and suitable to assess optimism in Malaysian cancer patients. It should be validated for use in other Malaysian populations.
The 5083 and 6061(T6) aluminum (Al) alloys are widely used in transportation industries and the development of structural designs because of their high toughness and high corrosion resistance. Friction stir welding (FSW) was performed to produce the dissimilar welded joint of Al5083-Al 6061(T6) under different welding parameters. However, softening behavior occurred in the friction stir welded (FSWed) samples because of grain coarsening or the dissolution of precipitation-hardening phases in the welding zone. Consequently, this research intended to investigate the effect of the post-weld heat treatment (PWHT) method on the mechanical property improvement of the dissimilar FSWed Al5083-Al6061(T6) and governing abnormal grain growth (AGG) through different welding parameters. The results showed PWHT enhanced the mechanical properties of dissimilar joints of Al5083-Al6061(T6). AGG was obtained in the microstructure of PWHTed joints, but appropriate PWHT could recover the dissolved precipitation-hardening particle in the heat-affected zone of the as-welded joint. Further, the tensile strength of the dissimilar joint increased from 181 MPa in the as-welded joint to 270 MPa in the PWHTed joint, showing 93% welding efficacy.
Melioidosis is an infectious disease caused by the pathogenic bacterium Burkholderia pseudomallei. Whole-genome sequencing revealed that the B. pseudomallei genome includes 5855 coding DNA sequences (CDSs), of which ∼25% encode hypothetical proteins. A pathogen-associated hypothetical protein, BPSL1038, was overexpressed in Escherichia coli, purified and crystallized using vapour-diffusion methods. A BPSL1038 protein crystal that grew using sodium formate as precipitant diffracted to 1.55 Å resolution. It belonged to space group C2221, with unit-cell parameters a = 85.36, b = 115.63, c = 46.73 Å. The calculated Matthews coefficient (VM) suggests that there are two molecules per asymmetric unit, with a solvent content of 48.8%.
TylP is one of five regulatory proteins involved in the regulation of antibiotic (tylosin) production, morphological and physiological differentiation in Streptomyces fradiae. Its function is similar to those of various γ-butyrolactone receptor proteins. In this report, N-terminally His-tagged recombinant TylP protein (rTylP) was overproduced in Escherichia coli and purified to homogeneity. The rTylP protein was crystallized from a reservoir solution comprising 34%(v/v) ethylene glycol and 5%(v/v) glycerol. The protein crystals diffracted X-rays to 3.05 Å resolution and belonged to the trigonal space group P3121, with unit-cell parameters a = b = 126.62, c = 95.63 Å.
Burkholderia pseudomallei is a highly versatile pathogen with ~25% of its genome annotated to encode hypothetical proteins. One such hypothetical protein, BPSL1038, is conserved across seven bacterial genera and 654 Burkholderia spp. Here, we present a 1.55 Å resolution crystal structure of BPSL1038. The overall structure folded into a modified βαββαβα ferredoxin fold similar to known Cas2 nucleases. The Cas2 equivalent catalytic aspartate (D11) pairs are conserved in BPSL1038 although B. pseudomallei has no known CRISPR associated system. Functional analysis revealed that BPSL1038 is a nuclease with endonuclease activity towards double-stranded DNA. The DNase activity is divalent ion independent and optimum at pH 6. The concentration of monovalent ions (Na+ and K+) is crucial for nuclease activity. An active site with a unique D11(X20)SST motif was identified and proposed for BPSL1038 and its orthologs. Structure modelling indicates the catalytic role of the D11(X20)SST motif and that the arginine residues R10 and R30 may interact with the nucleic acid backbone. The structural similarity of BPSL1038 to Cas2 proteins suggests that BPSL1038 may represent a sub-family of nucleases that share a common ancestor with Cas2.