In this study, the methanolysis process of sunflower oil was investigated to get high methyl esters (biodiesel) content using sodium methoxide. To reach to the best process conditions, central composite design (CCD) through response surface methodology (RSM) was employed. The optimal conditions predicted were the reaction time of 60 min, an excess stoichiometric amount of alcohol to oil ratio of 25%w/w and the catalyst content of 0.5%w/w, which lead to the highest methyl ester content (100%w/w). The methyl ester content of the mixture from gas chromatography analysis (GC) was compared to that of optimum point. Results, confirmed that there was no significant difference between the fatty acid methyl ester content of sunflower oil produced under the optimized condition and the experimental value (P ≥ 0.05). Furthermore, some fuel specifications of the resultant biodiesel were tested according to American standards for testing of materials (ASTM) methods. The outcome showed that the methyl ester mixture produced from the optimized condition met nearly most of the important biodiesel specifications recommended in ASTM D 6751 requirements. Thus, the sunflower oil methyl esters resulted from this study could be a suitable alternative for petrol diesels.
Graphene is one of the most promising materials in the field of nanotechnology and has attracted a tremendous amount of research interest in recent years. Due to its large specific surface area, high thermal conductivity, and superior electron mobility, graphene is regarded as an extremely attractive component for the preparation of composite materials. At the same time, the use of photocatalysts, particularly TiO(2), has also been widely studied for their potential in addressing various energy and environmental-related issues. However, bare TiO(2) suffers from low efficiency and a narrow light-response range. Therefore, the combination of graphene and TiO(2) is currently one of the most active interdisciplinary research areas and demonstrations of photocatalytic enhancement are abundant. This Review presents and discusses the current development of graphene-based TiO(2) photocatalysts. The theoretical framework of the composite, the synthetic strategies for the preparation and modification of graphene-based TiO(2) photocatalysts, and applications of the composite are reviewed, with particular attention on the photodegradation of pollutants and photocatalytic water splitting for hydrogen generation.
Burkholderia pseudomallei is resistant to a diverse group of antimicrobials including third generation cephalosporins whilst quinolones and aminoglycosides have no reliable effect. As therapeutic options are limited, development of more effective forms of immunotherapy is vital to avoid a fatal outcome. In an earlier study, we reported on the B. pseudomallei serine MprA protease, which is relatively stable over a wide pH and temperature range and digests physiological proteins. The present study was carried out to evaluate the immunogenicity and protective efficacy of the MprA as a potential vaccine candidate. In BALB/c mice immunized with recombinant MprA protease (smBpF4), a significantly high IgG titer was detectable. Isotyping studies revealed that the smBpF4-specific antibodies produced were predominantly IgG(1), proposing that immunization with smBpF4 triggered a Th2 immune response. Mice were immunized with smBpF4 and subsequently challenged with B. pseudomallei via the intraperitoneal route. Whilst control mice succumbed to the infection by day 9, smBpF4-immunized mice were protected against the lethal challenge and survived beyond 25 days post-infection. In conclusion, MprA is immunogenic in melioidosis patients whilst also eliciting a strong immune response upon bacterial challenge in mice and presents itself as a potential vaccine candidate for the treatment of melioidosis.
A 55-year-old woman presented with sudden onset of left-sided body weakness and numbness, which was diagnosed as multifocal cerebral infarct with right thalamic bleed. She had concurrent hypertension, diabetes mellitus and chronic kidney disease. She suffered from central poststroke pain and reactive depression as poststroke complications, for which amitriptyline was prescribed. Unfortunately, she developed symptoms suggestive of mania and psychosis upon initiation of medications, which resolved upon withdrawal of amitriptyline. Amitriptyline is effective for treatment of poststroke pain and particularly useful in concomitant depression. Unexpectedly, this patient developed new psychopathologies after initiation of this medication. This case highlights the development of new psychopathologies that could be due to the antidepressant, underlying bipolar disorder or a complication of the stroke itself. Primary care providers need to actively enquire regarding neuropsychiatric symptoms because they can adversely affect the patient's quality of life as well as impede rehabilitation efforts.
We developed a simple and sensitive method for the simultaneous detection of imatinib mesylate (IM) and its active metabolite, N-desmethyl imatinib (M1), in human serum samples. Separation was successfully achieved using an Agilent(®) ZORBAX Eclipse plus C(18) reversed phase column (50 mm × 2.1 mm, i.d.; 1.8 μm) under isocratic mobile phase conditions consisting of acetonitrile: 0.02 M potassium dihydrogen phosphate with 0.2% triethylamine at pH 3 (25:75, v/v) and ultra-violet detection was achieved at 235 nm. Extraction of the target compounds was completed using 100% cold acetonitrile. Good linearities (r(2)>0.99) for both IM and M1 were achieved for the concentration ranges of 50-1800 ng/mL and 50-360 ng/mL, respectively. The detection limits were 20 ng/mL and 10 ng/mL for M1 and IM, respectively. The intra- and inter-day precisions were less than 1% with percent recoveries of more than 90%. The method was successfully applied to calculate the pharmacokinetic parameters of chronic myeloid leukemia patients receiving imatinib. The method is suitable to be routinely applied for determination of IM and M1 in serum.
Hafnia alvei is an opportunistic pathogen involved in various types of nosocomical infections. The species has been found to inhabit food and mammalian guts. However, its status as an enteropathogen, and whether the food-inhabiting strains could be a source of gastrointestinal infection remains obscure. In this report we present a draft genome of H. alvei strain FB1 isolated from fish paste meatball, a food popular among Malaysian and Chinese populations. The data was generated on the Illumina MiSeq platform.
Amidst growing concerns over the spread of antibiotic-resistant Staphylococcus aureus strains, the identification of alternative therapeutic molecules has become paramount. Previously, we utilized a Caenorhabditis elegans-S. aureus screening platform to identify potential anti-infective agents from a collection of natural extracts and synthetic compounds. One of the hits obtained from the screen was the aqueous extract of Orthosiphon stamineus leaves (UE-12) that enhanced the survival of infected nematodes without interfering with bacterial growth. In this study, we used a fluorescent transgenic reporter strain and observed that the repressed expression of the lys-7 defense gene in infected nematodes was restored in the presence of UE-12. Analysis of a selected panel of PMK-1 and DAF-16-regulated transcripts and loss-of-function mutants in these pathways indicates that the protective role of UE-12 is mediated via the p38 MAP kinase and insulin-like signaling pathways. Further analysis of a panel of known bioactive compounds of UE-12 proposed eupatorin (C18H16O7) as the possible candidate active molecule contributing to the anti-infective property of UE-12. Taken together, these findings strongly suggest that the O. stamineus leaf extract is a promising anti-infective agent that confers an advantage in survival against S. aureus infection by modulating the immune response of the infected host.
The mitochondrial genome sequence of the Australian crayfish, Euastacus yarraensis, is documented and compared with other Australian crayfish genera. Euastacus yarraensis has a mitogenome of 15,548 base pairs consisting of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a non-coding AT-rich region. The base composition of E. yarraensis mitogenome is 32.39% for T, 22.45% for C, 34.43% for A, and 10.73% for G, with an AT bias of 66.82%. The mitogenome gene order conforms to what is considered the primitive arrangement for parastacid crayfish.
The main challenge in microfiltration (MF) is membrane fouling, which leads to a significant decline in permeate flux and a change in membrane selectivity over time. This work aims to elucidate the mechanisms of membrane fouling in cold MF of skim milk by identifying and quantifying the proteins and minerals involved in external and internal membrane fouling. Microfiltration was conducted using a 1.4-μm ceramic membrane, at a temperature of 6±1°C, cross-flow velocity of 6m/s, and transmembrane pressure of 159kPa, for 90min. Internal and external foulants were extracted from a ceramic membrane both after a brief contact between the membrane and skim milk, to evaluate instantaneous adsorption of foulants, and after MF. Four foulant streams were collected: weakly attached external foulants, weakly attached internal foulants, strongly attached external foulants, and strongly attached internal foulants. Liquid chromatography coupled with tandem mass spectrometry analysis showed that all major milk proteins were present in all foulant streams. Proteins did appear to be the major cause of membrane fouling. Proteomics analysis of the foulants indicated elevated levels of serum proteins as compared with milk in the foulant fractions collected from the adsorption study. Caseins were preferentially introduced into the fouling layer during MF, when transmembrane pressure was applied, as confirmed both by proteomics and mineral analyses. The knowledge generated in this study advances the understanding of fouling mechanisms in cold MF of skim milk and can be used to identify solutions for minimizing membrane fouling and increasing the efficiency of milk MF.
Glutathione transferases (GST) were purified from locally isolated bacteria, Acinetobacter calcoaceticus Y1, by glutathione-affinity chromatography and anion exchange, and their substrate specificities were investigated. SDS-polyacrylamide gel electrophoresis revealed that the purified GST resolved into a single band with a molecular weight (MW) of 23 kDa. 2-dimensional (2-D) gel electrophoresis showed the presence of two isoforms, GST1 (pI 4.5) and GST2 (pI 6.2) with identical MW. GST1 was reactive towards ethacrynic acid, hydrogen peroxide, 1-chloro-2,4-dinitrobenzene, and trans,trans-hepta-2,4-dienal while GST2 was active towards all substrates except hydrogen peroxide. This demonstrated that GST1 possessed peroxidase activity which was absent in GST2. This study also showed that only GST2 was able to conjugate GSH to isoproturon, a herbicide. GST1 and GST2 were suggested to be similar to F0KLY9 (putative glutathione S-transferase) and F0KKB0 (glutathione S-transferase III) of Acinetobacter calcoaceticus strain PHEA-2, respectively.
Novel nanoemulsion-based drug delivery systems (DDS) have been proposed as alternative and effective approach for the delivery of various types of poorly water-soluble drugs in the last decade. This nanoformulation strategy significantly improves the cell uptake and bioavailability of numerous hydrophobic drugs by increasing their solubility and dissolution rate, maintaining drug concentration within the therapeutic range by controlling the drug release rate, and reducing systemic side effects by targeting to specific disease site, thus offering a better patient compliance. To date, cavitation technology has emerged to be an energy-efficient and promising technique to generate such nanoscale emulsions encapsulating a variety of highly potent pharmaceutical agents that are water-insoluble. The micro-turbulent implosions of cavitation bubbles tear-off primary giant oily emulsion droplets to nano-scale, spontaneously leading to the formation of highly uniform drug contained nanodroplets. A substantial body of recent literatures in the field of nanoemulsions suggests that cavitation is a facile, cost-reducing yet safer generation tool, remarkably highlighting its industrial commercial viability in the development of designing novel nanocarriers or enhancing the properties of existing pharmaceutical products. In this review, the fundamentals of nanoemulsion and the principles involved in their formation are presented. The underlying mechanisms in the generation of pharmaceutical nanoemulsion under acoustic field as well as the advantages of using cavitation compared to the conventional techniques are also highlighted. This review focuses on recent nanoemulsion-based DDS development and how cavitation through ultrasound and hydrodynamic means is useful to generate the pharmaceutical grade nanoemulsions including the complex double or submicron multiple emulsions.
Quorum sensing (QS) is a mechanism adopted by bacteria to regulate expression of genes according to population density. N-acylhomoserine lactones (AHLs) are a type of QS signalling molecules commonly found in Gram-negative bacteria which have been reported to play a role in microbial spoilage of foods and pathogenesis. In this study, we isolated an AHL-producing Hafnia alvei strain (FB1) from spherical fish pastes. Analysis via high resolution triple quadrupole liquid chromatography/mass spectrometry (LC/MS) on extracts from the spent supernatant of H. alvei FB1 revealed the existence of two short chain AHLs: N-(3-oxohexanoyl) homoserine lactone (3-oxo-C6-HSL) and N-(3-oxo- octanoyl) homoserine lactone (3-oxo-C8-HSL). To our knowledge, this is the first report of the production of AHLs, especially 3-oxo-C8-HSL, by H. alvei.
Vancomycin has been documented to cause various adverse cutaneous reactions. We present a case report of a man, who developed a large localized erythematous plaque in his forearm following parenteral vancomycin therapy. We believe this to be the first reported case of such cutaneous reaction associated with parenteral vancomycin therapy.
Apart from their major function in the coordination of leukocyte recruitment, chemokines, in cooperation with their receptors, have been implicated in the progression of various diseases including different types of cancer, affecting survival, proliferation and metastasis. A complex network of chemokines and receptors exists in the tumor microenvironment and affects tumor development in various ways where chemokines activate typical signalling pathways by binding to the respective receptors. The identification and characterization of a group of atypical chemokine receptors [D6, Duffy antigen receptor for chemokines (DARC), ChemoCentryx chemokine receptor (CCX-CKR) and CXCR7] which appear to use unique biochemical properties to regulate the biological activities of these chemokines, is useful in the effort to therapeutically manipulate chemokines in a broad spectrum of diseases in which these chemokines play a critical role. The aim of this review was to investigate the combinatorial effect of two reported atypical chemokine receptors, D6 and DARC, on breast cancer cell invasion to understand their role and therapeutic potential in cancer treatment. In this regard, findings of the present review should be confirmed via the construction of recombinant D6 and DARC clones as well as the expression of the respective recombinant proteins using the Pichia pastoris (P. pastoris) expression system is to be performed in a future study in order to support findings of the current review.
The commercial freshwater crayfish Cherax quadricarinatus complete mitochondrial genome was recovered from partial genome sequencing using the MiSeq Personal Sequencer. The mitogenome has 15,869 base pairs consisting of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a non-coding AT-rich region. The base composition of C. quadricarinatus is 32.16% for T, 23.39% for C, 33.26% for A, and 11.19% for G, with an AT bias of 65.42%.
The complete mitochondrial genome of the conservationally significant Macquarie perch (Macquaria australasica) was obtained from low-coverage shotgun sequencing using the MiSeq sequencer. The M. australasica mitogenome has 16,496 base pairs (55% A + T content) made up of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a 819 bp non-coding AT-rich region. This is the first mitogenome sequence for the genus Macquaria, and the third to be reported for the family Percichthyidae.
The increasing popularity and widespread use of traditional Chinese herbs as alternative medicine have sparked an interest in understanding their biosafety, especially in decoctions that are consumed. This study aimed to assess the level of microbial and heavy metal contamination in commonly consumed herbal medicine in Malaysia and the effects of boiling on these contamination levels.
OBJECTIVE: In this study, 218 national drug rehabilitation center helpers in Malaysia were surveyed regarding perceptions of their on-the-job clinical supervision needs and preferred supervisor roles and emphasis areas in their supervision sessions.
METHODS: Descriptive analyses were conducted.
RESULTS: Findings suggest that drug rehabilitation center helpers in Malaysia expressed high level of on-the-job supervision needs. In addition, professional behavior skills were found to be the most desirable supervisory area followed by process, conceptualization, and personalization skills.
CONCLUSIONS: Implications for providing clinical supervision for drug rehabilitation center helpers in Malaysia were discussed, along with suggestions for future research.