The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Wim Dehaen - One of the best experts on this subject based on the ideXlab platform.
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Study of hole mobility in poly(N-vinylcarbazole) films doped with CdSe/ZnS quantum dots encapsulated by 11-(N-carbazolyl) Undecanoic Acid (C11)
Journal of Applied Physics, 2013Co-Authors: Adis Khetubol, Antti Hassinen, Yuliar Firdaus, Willem Vanderlinden, Sven Van Snick, Stijn Flamee, Bing Li, Steven De Feyter, Zeger Hens, Wim DehaenAbstract:We report the experimental study of hole transport in poly(vinylcarbazole) (PVK) films doped with colloidal CdSe/ZnS core-shell quantum dots (QDs) determined using the Time-of-Flight (TOF) method. The miscibility between PVK and the QDs is improved by capping the QDs with a novel 11-(N-carbazolyl) Undecanoic Acid (C11) ligand instead of commonly used organic ligands, such as oleic Acid. The study of the hole mobility of the pristine and doped PVK films with a doping concentration of the C11 capped QDs ranging from 1.61 × 1017 to 7.10 × 1018 dots/cm3 was performed as a function of electric field and temperature in the range of 105–106 V/cm and 298–338 K, respectively. Upon increasing the QD concentration, a decrease of hole mobility was observed by up to nearly 2 orders in magnitude at a doping concentration of 3.87 × 1018 dots/cm3 at T = 298 K. This suggests that the QDs induce shallow hole traps. The field and temperature dependence of the hole mobility was characterized using the Bassler disorder model ...
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study of hole mobility in poly n vinylcarbazole films doped with cdse zns quantum dots encapsulated by 11 n carbazolyl Undecanoic Acid c11
Journal of Applied Physics, 2013Co-Authors: Adis Khetubol, Antti Hassinen, Yuliar Firdaus, Willem Vanderlinden, Sven Van Snick, Stijn Flamee, Bing Li, Steven De Feyter, Zeger Hens, Wim DehaenAbstract:We report the experimental study of hole transport in poly(vinylcarbazole) (PVK) films doped with colloidal CdSe/ZnS core-shell quantum dots (QDs) determined using the Time-of-Flight (TOF) method. The miscibility between PVK and the QDs is improved by capping the QDs with a novel 11-(N-carbazolyl) Undecanoic Acid (C11) ligand instead of commonly used organic ligands, such as oleic Acid. The study of the hole mobility of the pristine and doped PVK films with a doping concentration of the C11 capped QDs ranging from 1.61 × 1017 to 7.10 × 1018 dots/cm3 was performed as a function of electric field and temperature in the range of 105–106 V/cm and 298–338 K, respectively. Upon increasing the QD concentration, a decrease of hole mobility was observed by up to nearly 2 orders in magnitude at a doping concentration of 3.87 × 1018 dots/cm3 at T = 298 K. This suggests that the QDs induce shallow hole traps. The field and temperature dependence of the hole mobility was characterized using the Bassler disorder model ...
Antonio Rossi - One of the best experts on this subject based on the ideXlab platform.
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transcriptome wide survey of gene expression changes and alternative splicing in trichophyton rubrum in response to Undecanoic Acid
Scientific Reports, 2018Co-Authors: Niege Silva Mendes, Nilce Maria Martinezrossi, Tamires Aparecida Bitencourt, Pablo Rodrigo Sanches, Rafael Silvarocha, Antonio RossiAbstract:While fatty Acids are known to be toxic to dermatophytes, key physiological aspects of the Trichophyton rubrum response to Undecanoic Acid (UDA), a medium chain saturated fatty Acid (C11:0), are not well understood. Thus, we analysed RNA-seq data from T. rubrum exposed to sub-lethal doses of UDA for 3 and 12 h. Three putative pathways were primarily involved in UDA detoxification: lipid metabolism and cellular membrane composition, oxidative stress, and pathogenesis. Biochemical assays showed cell membrane impairment, reductions in ergosterol content, and an increase in keratinolytic activity following UDA exposure. Moreover, we assessed differential exon usage and intron retention following UDA exposure. A key enzyme supplying guanine nucleotides to cells, inosine monophosphate dehydrogenase (IMPDH), showed high levels of intron 2 retention. Additionally, phosphoglucomutase (PGM), which is involved in the glycogen synthesis and degradation as well as cell wall biosynthesis, exhibited a significant difference in exon 4 usage following UDA exposure. Owing to the roles of these enzymes in fungal cells, both have emerged as promising antifungal targets. We showed that intron 2 retention in impdh and exon 4 skipping in pgm might be related to an adaptive strategy to combat fatty Acid toxicity. Thus, the general effect of UDA fungal toxicity involves changes to fungal metabolism and mechanisms for regulating pre-mRNA processing events.
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in vitro susceptibility to antimycotic drug Undecanoic Acid a medium chain fatty Acid is nutrient dependent in the dermatophyte trichophyton rubrum
World Journal of Microbiology & Biotechnology, 2011Co-Authors: Nalu T A Peres, Jeny R Cursinosantos, Antonio Rossi, Nilce Maria MartinezrossiAbstract:The antimycotic activity of fatty Acids has long been known, and their presence in human skin and sweat appears to protect the host against superficial mycoses. Undecanoic Acid is a medium-chain fatty Acid that has been used in the treatment of dermatophytoses in humans. In this study, we selected one Trichophyton rubrum Undecanoic Acid-resistant strain that showed a marked reduction in its capacity to grow on human nail fragments, which correlated with the reduced activity of secreted keratinolytic proteases. Moreover, the susceptibility of T. rubrum to Undecanoic Acid is also dependent on the carbon source utilized by both control and resistant strains. The growth of the control strain was strongly inhibited by Undecanoic Acid in Sabouraud medium or in cultures supplemented with low-fat milk, whereas it was ineffective when the cultures were supplemented with Tween 20 or keratin as the carbon source, suggesting that nutrient conditions are crucial in establishing a susceptibility to antifungal drugs, which is helpful for the isolation and characterization of resistant strains, and in the screening for new antifungal drugs.
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A Single Amino Acid Substitution in One of the Lipases of Aspergillus nidulans Confers Resistance to the Antimycotic Drug Undecanoic Acid
Biochemical Genetics, 2008Co-Authors: Ana G. Brito-madurro, Nalu T A Peres, Rolf A. Prade, João M. Madurro, Mário A. Santos, Jeny R. Cursino-santos, Nilce M. Martinez-rossi, Antonio RossiAbstract:A plausible approach to evaluate the inhibitory action of antifungals is through the investigation of the fungal resistance to these drugs. We describe here the molecular cloning and initial characterization of the A. nidulans lipA gene, where mutation ( lipA1 ) conferred resistance to Undecanoic Acid, the most fungitoxic fatty Acid in the C_7:0–C_18:0 series. The lipA gene codes for a putative lipase with the sequence consensus GVSIS and WIFGGG as the catalytic signature. Comparison of the wild-type and LIP1 mutant strain nucleotide sequences showed a G → A change in lipA1 allele, which results in a Glu^214 → Lys substitution in LipA protein. This ionic charge change in a conserved LipA region, next to its catalytic site, may have altered the catalytic properties of this enzyme resulting in resistance to Undecanoic Acid.
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a single amino Acid substitution in one of the lipases of aspergillus nidulans confers resistance to the antimycotic drug Undecanoic Acid
Biochemical Genetics, 2008Co-Authors: Ana G Britomadurro, Nalu T A Peres, Jeny R Cursinosantos, Nilce Maria Martinezrossi, Rolf A. Prade, João M. Madurro, Mário A. Santos, Antonio RossiAbstract:A plausible approach to evaluate the inhibitory action of antifungals is through the investigation of the fungal resistance to these drugs. We describe here the molecular cloning and initial characterization of the A. nidulans lipA gene, where mutation (lipA1) conferred resistance to Undecanoic Acid, the most fungitoxic fatty Acid in the C7:0–C18:0 series. The lipA gene codes for a putative lipase with the sequence consensus GVSIS and WIFGGG as the catalytic signature. Comparison of the wild-type and LIP1 mutant strain nucleotide sequences showed a G → A change in lipA1 allele, which results in a Glu214 → Lys substitution in LipA protein. This ionic charge change in a conserved LipA region, next to its catalytic site, may have altered the catalytic properties of this enzyme resulting in resistance to Undecanoic Acid.
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effect of Undecanoic Acid on the production of esterases and lipases by aspergillus nidulans
Annals of Microbiology, 2005Co-Authors: Ana G Britomadurro, João M. Madurro, Nilce Maria Martinezrossi, Sara Cuadrosorellana, Antonio RossiAbstract:In this report, Undecanoic Acid is shown to affect enzymatic activity in the fungus Aspergillus nidulans. In a UDA-resistant mutant strain, the extracellular activity of lipases on p-nitrophenol decreased approximately 40% compared to the wild-type strain. The lipase activity on Tween 80 was completely inhibited by UDA. Alterations were observed in the electrophoretic profile and activity of mycelial esterases. However, there were no differences in the activity of phospholipase C in these strains. The effect of UDA on the activity of specific enzymes may represent a response to cellular stress or an intrinsic mechanism of resistance in filamentous fungi.
Adis Khetubol - One of the best experts on this subject based on the ideXlab platform.
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Study of hole mobility in poly(N-vinylcarbazole) films doped with CdSe/ZnS quantum dots encapsulated by 11-(N-carbazolyl) Undecanoic Acid (C11)
Journal of Applied Physics, 2013Co-Authors: Adis Khetubol, Antti Hassinen, Yuliar Firdaus, Willem Vanderlinden, Sven Van Snick, Stijn Flamee, Bing Li, Steven De Feyter, Zeger Hens, Wim DehaenAbstract:We report the experimental study of hole transport in poly(vinylcarbazole) (PVK) films doped with colloidal CdSe/ZnS core-shell quantum dots (QDs) determined using the Time-of-Flight (TOF) method. The miscibility between PVK and the QDs is improved by capping the QDs with a novel 11-(N-carbazolyl) Undecanoic Acid (C11) ligand instead of commonly used organic ligands, such as oleic Acid. The study of the hole mobility of the pristine and doped PVK films with a doping concentration of the C11 capped QDs ranging from 1.61 × 1017 to 7.10 × 1018 dots/cm3 was performed as a function of electric field and temperature in the range of 105–106 V/cm and 298–338 K, respectively. Upon increasing the QD concentration, a decrease of hole mobility was observed by up to nearly 2 orders in magnitude at a doping concentration of 3.87 × 1018 dots/cm3 at T = 298 K. This suggests that the QDs induce shallow hole traps. The field and temperature dependence of the hole mobility was characterized using the Bassler disorder model ...
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study of hole mobility in poly n vinylcarbazole films doped with cdse zns quantum dots encapsulated by 11 n carbazolyl Undecanoic Acid c11
Journal of Applied Physics, 2013Co-Authors: Adis Khetubol, Antti Hassinen, Yuliar Firdaus, Willem Vanderlinden, Sven Van Snick, Stijn Flamee, Bing Li, Steven De Feyter, Zeger Hens, Wim DehaenAbstract:We report the experimental study of hole transport in poly(vinylcarbazole) (PVK) films doped with colloidal CdSe/ZnS core-shell quantum dots (QDs) determined using the Time-of-Flight (TOF) method. The miscibility between PVK and the QDs is improved by capping the QDs with a novel 11-(N-carbazolyl) Undecanoic Acid (C11) ligand instead of commonly used organic ligands, such as oleic Acid. The study of the hole mobility of the pristine and doped PVK films with a doping concentration of the C11 capped QDs ranging from 1.61 × 1017 to 7.10 × 1018 dots/cm3 was performed as a function of electric field and temperature in the range of 105–106 V/cm and 298–338 K, respectively. Upon increasing the QD concentration, a decrease of hole mobility was observed by up to nearly 2 orders in magnitude at a doping concentration of 3.87 × 1018 dots/cm3 at T = 298 K. This suggests that the QDs induce shallow hole traps. The field and temperature dependence of the hole mobility was characterized using the Bassler disorder model ...
Shunmugiah Karutha Pandian - One of the best experts on this subject based on the ideXlab platform.
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synergistic antibiofilm efficacy of Undecanoic Acid and auxins against quorum sensing mediated biofilm formation of luminescent vibrio harveyi
Aquaculture, 2019Co-Authors: Ramesh Salini, Sivasubramanian Santhakumari, Arumugam Veera Ravi, Shunmugiah Karutha PandianAbstract:Abstract Vibrio harveyi are Gram-negative marine luminescent bacteria and most of them are multi-drug resistant pathogens. The incidence of biofilm mediated antibiotic resistance stresses the quest for novel therapeutics to treat luminescent vibriosis in aquaculture. This study intended to explore the combinatorial effect of Undecanoic Acid (UDA) along with auxins ((Indole-3-Acetic Acid (IAA) and Indole-3-Butyric Acid (IBA)) against V. harveyi biofilm formation under in vitro and in vivo conditions. The minimal inhibitory concentration (MIC) of UDA against planktonic V. harveyi was found to be 20 μg/ml and for auxins it was 200 μg/ml. Furthermore, the synergism of both combinations was calculated through fractional inhibitory concentration (FIC). The FIC of UDA with auxins to inhibit biofilm formation was identified as 10 μg/ml for UDA along with 30 μg/ml of either IAA or IBA. Light and confocal laser scanning microscopic (CLSM) analyses further confirmed that these combinations effectively prevented the initial attachment, microcolonies and also dispersed the mature biofilm formation of V. harveyi. Similar results were obtained for bioluminescence, caseinase and swarming motility of V. harveyi, where UDA with IAA or IBA combinations reduced the bioluminescence by upto 93.6% and 76.7%, respectively. Besides, in support of in vitro results, the real-time PCR analysis of quorum sensing (QS) genes revealed the master regulators luxO, luxQ, luxR and luxS to be down-regulated upon treatment with these combinations in V. harveyi. Further in vivo studies using brine shrimp larvae also manifested the enhanced survival rate and reduced adherence of test pathogen upon treatment with these compounds.
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synergistic effect of quinic Acid derived from syzygium cumini and Undecanoic Acid against candida spp biofilm and virulence
Frontiers in Microbiology, 2018Co-Authors: Subramanian Muthamil, Boopathi Balasubramaniam, Krishnaswamy Balamurugan, Shunmugiah Karutha PandianAbstract:In recent decades, fungal infections have incredibly increased with Candida genus as the major cause of morbidity and mortality in hospitalized and immunocompromised patients. Most of the Candida species are proficient in biofilm formation on implanted medical devices as well as human tissues. Biofilm related Candida infections are very difficult to treat using common antifungal agents owing to their increased drug resistance. To address these issues, the present study investigated the antibiofilm and antivirulent properties of Syzygium cumini derived quinic Acid in combination with known antifungal compound Undecanoic Acid. Initially, antibiofilm potential of S. cumini leaf extract was assessed and the active priniciples were identified through gas chromatography and mass spectrometry analysis. Among the compounds identified, quinic Acid was one of the major compounds. The interaction between quinic Acid and Undecanoic Acid was found to be synergistic in the Fractional inhibitory concentration index (≤ 0.5). Results of in vitro assays and gene expression analysis suggested that the synergistic combinations of quinic Acid and Undecanoic Acid significantly inhibited virulence traits of Candida spp. such as the biofim formation, yeast-to-hyphal transition, extracellular polymeric substances production, filamentation, secreted hydrolases production and ergosterol biosynthesis. In addition, result of in vivo studies using Caenorhabditis elegans demonstrated the nontoxic nature of QA-UDA combination and antivirulence effect against Candida spp. For the first time, synergistic antivirulence ability of quinic Acid and Undecanoic Acid was explored against Candida spp. Thus, results obtained from the present study suggest that combination of phytochemicals might be used an alternate therapeutic strategy for the prevention and treatment of biofilm associated candida infection.
Nilce Maria Martinezrossi - One of the best experts on this subject based on the ideXlab platform.
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transcriptome wide survey of gene expression changes and alternative splicing in trichophyton rubrum in response to Undecanoic Acid
Scientific Reports, 2018Co-Authors: Niege Silva Mendes, Nilce Maria Martinezrossi, Tamires Aparecida Bitencourt, Pablo Rodrigo Sanches, Rafael Silvarocha, Antonio RossiAbstract:While fatty Acids are known to be toxic to dermatophytes, key physiological aspects of the Trichophyton rubrum response to Undecanoic Acid (UDA), a medium chain saturated fatty Acid (C11:0), are not well understood. Thus, we analysed RNA-seq data from T. rubrum exposed to sub-lethal doses of UDA for 3 and 12 h. Three putative pathways were primarily involved in UDA detoxification: lipid metabolism and cellular membrane composition, oxidative stress, and pathogenesis. Biochemical assays showed cell membrane impairment, reductions in ergosterol content, and an increase in keratinolytic activity following UDA exposure. Moreover, we assessed differential exon usage and intron retention following UDA exposure. A key enzyme supplying guanine nucleotides to cells, inosine monophosphate dehydrogenase (IMPDH), showed high levels of intron 2 retention. Additionally, phosphoglucomutase (PGM), which is involved in the glycogen synthesis and degradation as well as cell wall biosynthesis, exhibited a significant difference in exon 4 usage following UDA exposure. Owing to the roles of these enzymes in fungal cells, both have emerged as promising antifungal targets. We showed that intron 2 retention in impdh and exon 4 skipping in pgm might be related to an adaptive strategy to combat fatty Acid toxicity. Thus, the general effect of UDA fungal toxicity involves changes to fungal metabolism and mechanisms for regulating pre-mRNA processing events.
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in vitro susceptibility to antimycotic drug Undecanoic Acid a medium chain fatty Acid is nutrient dependent in the dermatophyte trichophyton rubrum
World Journal of Microbiology & Biotechnology, 2011Co-Authors: Nalu T A Peres, Jeny R Cursinosantos, Antonio Rossi, Nilce Maria MartinezrossiAbstract:The antimycotic activity of fatty Acids has long been known, and their presence in human skin and sweat appears to protect the host against superficial mycoses. Undecanoic Acid is a medium-chain fatty Acid that has been used in the treatment of dermatophytoses in humans. In this study, we selected one Trichophyton rubrum Undecanoic Acid-resistant strain that showed a marked reduction in its capacity to grow on human nail fragments, which correlated with the reduced activity of secreted keratinolytic proteases. Moreover, the susceptibility of T. rubrum to Undecanoic Acid is also dependent on the carbon source utilized by both control and resistant strains. The growth of the control strain was strongly inhibited by Undecanoic Acid in Sabouraud medium or in cultures supplemented with low-fat milk, whereas it was ineffective when the cultures were supplemented with Tween 20 or keratin as the carbon source, suggesting that nutrient conditions are crucial in establishing a susceptibility to antifungal drugs, which is helpful for the isolation and characterization of resistant strains, and in the screening for new antifungal drugs.
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a single amino Acid substitution in one of the lipases of aspergillus nidulans confers resistance to the antimycotic drug Undecanoic Acid
Biochemical Genetics, 2008Co-Authors: Ana G Britomadurro, Nalu T A Peres, Jeny R Cursinosantos, Nilce Maria Martinezrossi, Rolf A. Prade, João M. Madurro, Mário A. Santos, Antonio RossiAbstract:A plausible approach to evaluate the inhibitory action of antifungals is through the investigation of the fungal resistance to these drugs. We describe here the molecular cloning and initial characterization of the A. nidulans lipA gene, where mutation (lipA1) conferred resistance to Undecanoic Acid, the most fungitoxic fatty Acid in the C7:0–C18:0 series. The lipA gene codes for a putative lipase with the sequence consensus GVSIS and WIFGGG as the catalytic signature. Comparison of the wild-type and LIP1 mutant strain nucleotide sequences showed a G → A change in lipA1 allele, which results in a Glu214 → Lys substitution in LipA protein. This ionic charge change in a conserved LipA region, next to its catalytic site, may have altered the catalytic properties of this enzyme resulting in resistance to Undecanoic Acid.
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effect of Undecanoic Acid on the production of esterases and lipases by aspergillus nidulans
Annals of Microbiology, 2005Co-Authors: Ana G Britomadurro, João M. Madurro, Nilce Maria Martinezrossi, Sara Cuadrosorellana, Antonio RossiAbstract:In this report, Undecanoic Acid is shown to affect enzymatic activity in the fungus Aspergillus nidulans. In a UDA-resistant mutant strain, the extracellular activity of lipases on p-nitrophenol decreased approximately 40% compared to the wild-type strain. The lipase activity on Tween 80 was completely inhibited by UDA. Alterations were observed in the electrophoretic profile and activity of mycelial esterases. However, there were no differences in the activity of phospholipase C in these strains. The effect of UDA on the activity of specific enzymes may represent a response to cellular stress or an intrinsic mechanism of resistance in filamentous fungi.
