163 research outputs found

    ANTIFUNGAL EFFECT OF HYPTIS SUAVEOLENS OIL MICROEMULSION BASED CARBOXYMETHYL MUNGBEAN GEL FOR TOPICAL DELIVERY

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    Objective: Conventional topical antifungal formulations limit the effectiveness of antifungal therapy. The aim of this study was to formulate effective antifungal microemulsion of H. suaveolens oil based carboxymethyl mungbean (CMMS) gel.Methods: H. suaveolens oil was obtained by steam distillation. Standard of H. suaveolens oil was performed by gas chromatography mass spectrometry (GC/MS). A high-viscosity CMMS was prepared and its mucoadhesive property was determined using modified USP dissolution test apparatus. H. suaveolens oil microemulsion based CMMS gel as transdermal drug carrier was then developed. Finally, in vitro drug release study and antifungal activity were determined.Results: GC/MS analysis exhibited that b-Caryophyllene, Sabinene and Limonene are the major components of H. suaveolens oil. CMMS gel revealed good mucoadhesive potential which depended on pH of the medium. A higher retention time in pH 4.5 medium than pH 10 medium was observed. Clotrimazole-loaded H. suaveolens oil microemulsions based CMMS gel was successful prepared and in vitro sustained release of clotrimazole was determined. Clotrimazole-loaded H. suaveolens oil microemulsions based CMMS gel had potent antifungal activity against all studied dermatophytes and Candida albican with higher inhibition zone than H. suaveolens oil microemulsions based CMMS gel, H. suaveolens oil and commercial clotrimazole cream.Conclusion: H. suaveolens oil microemulsions based CMMS gel present promising as an effective alternative for topical delivery of antifungal agents.Â

    Single silicon vacancy-oxygen complex defect and variable retention time phenomenon in dynamic random access memories

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    The variable retention time phenomenon has recently been highlighted as an important issue in dynamic random access memory (DRAM) technology. Based on electrically detected magnetic resonance and simulation studies, we suggest that a single Si vacancy-oxygen complex defect is responsible for this phenomenon, when the defect is embedded in the near surface drain-gate boundary of a DRAM cell

    Examining the ribonuclease H primer grip of HIV-1 reverse transcriptase by charge neutralization of RNA/DNA hybrids

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    The crystal structure of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) bound to an RNA/DNA hybrid reveals an extensive network of contacts with the phosphate backbone of the DNA strand ∼4–9 bp downstream from the ribonuclease H (RNase H) catalytic center. Collectively designated as ‘the RNase H primer grip’, this motif contains a phosphate binding pocket analogous to the human and Bacillus halodurans RNases H. The notion that the RNase H primer grip mediates the trajectory of RNA/DNA hybrids accessing the RNase H active site suggests that locally neutralizing the phosphate backbone may be exploited to manipulate nucleic acid flexibility. To examine this, we introduced single and tandem methylphosphonate substitutions through the region of the DNA primer contacted by the RNase H primer grip and into the RNase H catalytic center. The ability of mutant hybrids to support RNase H and DNA polymerase activity was thereafter examined. In addition, site-specific chemical footprinting was used to evaluate movement of the DNA polymerase and RNase H domains. We show here that minor alteration to the RNase H primer can have a dramatic effect on enzyme positioning, and discuss these findings in light of recent crystallography of human RNase H containing an RNA/DNA hybrid

    Energetics of base flipping at a DNA mismatch site confined at the latch constriction of α-hemolysin

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    Unique, two-state modulating current signatures are observed when a cytosine-cytosine mismatch pair is confined at the 2.4 nm latch constriction of the [small alpha]-hemolysin ([small alpha]HL) nanopore. We have previously speculated that the modulation is due to base flipping at the mismatch site. Base flipping is a biologically significant mechanism in which a single base is rotated out of the DNA helical stack by 180[degree]. It is the mechanism by which enzymes are able to access bases for repair operations without disturbing the global structure of the helix. Here, temperature dependent ion channel recordings of individual double-stranded DNA duplexes inside [small alpha]-HL are used to derive thermodynamic ([capital Delta]H, [capital Delta]S) and kinetic (Ea) parameters for base flipping of a cytosine at an unstable cytosine-cytosine mismatch site. The measured activation energy for flipping a cytosine located at the latch of [small alpha]HL out of the helix (18 +/- 1 kcal mol-1) is comparable to that previously reported for base flipping at mismatch sites from NMR measurements and potential mean force calculations. We propose that the [small alpha]HL nanopore is a useful tool for measuring conformational changes in dsDNA at the single molecule level

    Bioactive Compounds of Rambutan (Nephelium lappaceum L.)

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    Rambutan, a widely popular tropical fruit encompasses rich amount of bioactive compounds. All parts of this plant (leaves, bark, root, fruits, fruit skin, pulp and seeds) finds traditional usage, and are linked with high therapeutic values. Rambutan fruits parts like that of peel, pulp and seeds have been scientifically investigated in-depth and is reported to encompass high amounts of bioactive compounds (such as polyphenol, flavonoid, alkaloid, essential mineral, dietary fiber). These compounds contribute towards antioxidant, antimicrobial, anticancer, antidiabetic and anti-obesity activities. However, literature pertaining towards potential industrial applications (food, cosmetics, pharmaceutical) of rambutan fruits are limited. In the present chapter, it is intended to document some of the interesting research themes published on rambutan fruits, and identify the existing gaps to open up arena for future research work.This chapter theme is based on our ongoing project—VALORTECH, which has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 810630

    Revolutions from above: worker training as trasformismo in South Korea

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    While making very substantial changes to the population's working conditions, government strategies to foster economic development in South Korea have historically attempted to keep worker involvement, in terms of influence on the process, to a bare minimum. Applying the Gramscian concept of passive revolution, this article analyses governance mechanisms and production relations over a history of authoritarianism and up to the contemporary period of democratic reform. Trasformismo, which is a strategy of limited concessions, has been provided via vocational training for workers. Despite this attempt at inclusion, it is concluded that workers have not enjoyed full participation in negotiation for their welfare at any time in Korean history

    Neural Network Development in Late Adolescents during Observation of Risk-Taking Action

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    Emotional maturity and social awareness are important for adolescents, particularly college students beginning to face the challenges and risks of the adult world. However, there has been relatively little research into personality maturation and psychological development during late adolescence and the neural changes underlying this development. We investigated the correlation between psychological properties (neuroticism, extraversion, anxiety, and depression) and age among late adolescents (n = 25, from 18 years and 1 month to 22 years and 8 months). The results revealed that late adolescents became less neurotic, less anxious, less depressive and more extraverted as they aged. Participants then observed video clips depicting hand movements with and without a risk of harm (risk-taking or safe actions) during functional magnetic resonance imaging (fMRI). The results revealed that risk-taking actions elicited significantly stronger activation in the bilateral inferior parietal lobule, temporal visual regions (superior/middle temporal areas), and parieto-occipital visual areas (cuneus, middle occipital gyri, precuneus). We found positive correlations of age and extraversion with neural activation in the insula, middle temporal gyrus, lingual gyrus, and precuneus. We also found a negative correlation of age and anxiety with activation in the angular gyrus, precentral gyrus, and red nucleus/substantia nigra. Moreover, we found that insula activation mediated the relationship between age and extraversion. Overall, our results indicate that late adolescents become less anxious and more extraverted with age, a process involving functional neural changes in brain networks related to social cognition and emotional processing. The possible neural mechanisms of psychological and social maturation during late adolescence are discussed
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