A novel, highly sensitive, selective, and simple kinetic method was developed for the determinati... more A novel, highly sensitive, selective, and simple kinetic method was developed for the determination of Mo(VI) based on its catalytic effect on the oxidation of 1-amino-2-naphthol-4-sulfonic acid (ANSA) with H 2 O 2 . The reaction was followed spectrophotometrically by tracing the oxidized product at 465 nm after 30 min of mixing the reagents. The optimum reaction conditions were: 10 mmol l −1 ANSA, 50 mmol l −1 H 2 O 2 , 100 mmol l −1 acetate buffer of pH 5.0 ± 0.05 and at 40 • C. Addition of 200 g ml −1 diethylenetriaminepentaacetic acid (DTPA) conferred high selectivity for the proposed method. Following the recommended procedure, Mo(VI) could be determined with a linear calibration graph up to 2.5 ng ml −1 and a detection limit, based on the 3S b -criterion, of 0.027 ng ml −1 . The unique sensitivity and selectivity of the implemented method allowed its direct application to the determination of Mo(VI) in natural and industrial waste water. The method was validated by comparison with the standard ETAAS method. Moreover, published catalytic-spectrophotometric methods for the determination of molybdenum were reviewed.
Dietary polyphenols are associated with protection against chronic diseases such as cardiovascula... more Dietary polyphenols are associated with protection against chronic diseases such as cardiovascular disease. Pharmacological studies show a range of bioactivities and efficacy attributable to specific polyphenols. While many fruits are rich in polyphenols, wide cultivar variation of polyphenol composition is common. Our objective was to determine the composition of major bioactive polyphenols in 29 prevarietal selections of Western Australian plums, and Black Amber as an evaluation in developing breeding tools to develop fruit that may have enhanced health-promoting capacities. Total phenolics were quantified colorimetrically; selected polyphenols were quantified by HPLC; and the total antioxidant capacity (TAC) was measured by the antioxidant inhibition of oxygen radicals (AIOR) assay. Total phenolic concentration was significantly correlated with TAC (R = 0.95, P < 0.01). Neo-chlorogenic acid and quercetin glycosides were found to be the predominant polyphenols (mean 29.9 mg·kg −1 and 50.7 mg·kg −1 , respectively). No significant correlations were found between the composition of predominant polyphenols in plums and the TAC. We argue that the value of in vitro TAC assays to breeding programs may be limited, and future research should focus on the heritability of known bioactive polyphenols.
In order to advise regarding the religious practice of withholding food, we studied the metabolic... more In order to advise regarding the religious practice of withholding food, we studied the metabolic changes after successive 15 days of recurrent fasting of 13 hours every day in maternal plasma and liquor amnii of obese normal gravids and gestational diabetics in their third trimester. There were no significant differences between those who fasted that period for one day prior to elective cesarean section (CS) and those who fasted the same period repeatedly for 15 days. The fasted gravids had significant rises in glycerol, beta-hydroxybutyrate (BOHB) and nonesterified fatty acids (NEFA) (P less than 0.0001, P less than 0.005 and P less than 0.01, respectively) in maternal plasma, compared to unfasted gravid groups and ungravid fasted group. No significant metabolic difference was found in the liquor amnii withdrawn from fasted and unfasted groups. The influence of such short term of starvation on the fetal metabolic profile was studied in the cord blood during cesarean section (CS). Glucose, glycerol and NEFA were significantly lower in arterial than in venous cord plasma (P less than 0.05, P less than 0.01 and P less than 0.01, respectively) indicating that the fetus could utilize these substrates. Positive correlation was found between the levels of BOHB in the mother and venous cord plasma on the one hand and their levels in the arterial cord plasma and liquor amnii on the other hand implying that this substrate passes unutilized through the fetus to the liquor amnii. A pregnant woman in the third trimester should not withhold food for long periods.
Titanium nitride (TiN) widely used as hard coating material, was coated on tool steels, namely on... more Titanium nitride (TiN) widely used as hard coating material, was coated on tool steels, namely on high-speed steel (HSS) and D2 tool steel by physical vapor deposition method. The study concentrated on cathodic arc physical vapor deposition (CAPVD), a technique used for the deposition of hard coatings for tooling applications, and which has many advantages. The main drawback of this technique, however, is the formation of macrodroplets (MDs) during deposition, resulting in films with rougher morphology. Various standard characterization techniques and equipment, such as electron microscopy, atomic force microscopy, hardness testing machine, scratch tester, and pin-on-disc machine, were used to analyze and quantify the following properties and parameters: surface morphology, thickness, hardness, adhesion, and coefficient of friction (COF) of the deposited coatings. Surface morphology revealed that the MDs produced during the etching stage, protruded through the TiN film, resulting in film with deteriorated surface features. Both coating thickness and indentation loads influenced the hardness of the deposited coatings. The coatings deposited on HSS exhibit better adhesion compared to those on D2 tool steel. Standard deviation indicates that the coating deposited with thickness around 6.7 µm showed the most stable trend of COF versus sliding distance.
... Titre du document / Document title. Modification of wood surface by UV curing of epoxy materi... more ... Titre du document / Document title. Modification of wood surface by UV curing of epoxy material. Auteur(s) / Author(s). KHAN Mubarak A. (1) ; RAHMAN Mokhlesur (1) ; IDRISSALI KM (1) ; Affiliation(s) du ou des auteurs / Author(s) Affiliation(s). ...
Pneumococcal carriage is common in children that may account for the high incidence of disease in... more Pneumococcal carriage is common in children that may account for the high incidence of disease in this age group. Recent studies in animals suggest an important role for CD4 þ Tcells, T helper type 17 (Th17) cells in particular, in pneumococcal clearance. Whether this Th17-mediated mechanism operates in humans and what pneumococcal components activate Th17 are unknown. We investigated the ability of domain 4 pneumolysin (D4Ply) to activate CD4 þ Tcells including Th17 in human nasopharynx-associated lymphoid tissue (NALT) and peripheral blood. We show that D4Ply elicited a prominent CD4 þ T-cell proliferative response. More importantly, D4Ply elicited a significant memory Th17 response in NALT, and a moderate response in peripheral blood mononuclear cells (PBMCs). This D4Ply-elicited memory Th17 response was more marked in carriage À than in carriage þ children in both NALTand PBMCs. In contrast, no difference was shown in D4Plyinduced Th1 response between the two groups. We also show D4Ply activated human monocytes and murine macrophages that was in part dependent on Toll-like receptor 4 (TLR-4). Our results support a protective role of Th17 against pneumococcal carriage in human nasopharynx, and identify a novel property of D4Ply to activate Th17 in NALT that may offer an attractive vaccine candidate in intranasal immunization against pneumococcal infection.
... Permissions & Reprints. The mutual solubilities of water with supercritical and liquid ca... more ... Permissions & Reprints. The mutual solubilities of water with supercritical and liquid carbon dioxides *1. MB King * , A. Mubarak , JD Kim and TR Bott. School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK. ...
... SR Foltyn, EJ Peterson, JY Coulter, PN Arendt, QX Jia, PC Dowden, MP Maley, XD Wu, and DE Pet... more ... SR Foltyn, EJ Peterson, JY Coulter, PN Arendt, QX Jia, PC Dowden, MP Maley, XD Wu, and DE Peterson Superconductivity Technology Center ... A change in c-axis lattice parameter suggests that possible causes for this degradation are oxygen deficiency or cation disorder with ...
Flavonoids and nitrates in fruits and vegetables may protect against cardiovascular disease. Diet... more Flavonoids and nitrates in fruits and vegetables may protect against cardiovascular disease. Dietary flavonoids and nitrates can augment nitric oxide status via distinct pathways, which may improve endothelial function and lower blood pressure. Recent studies suggest that the combination of flavonoids and nitrates can enhance nitric oxide production in the stomach. Their combined effect in the circulation is unclear. Here, our objective was to investigate the independent and additive effects of flavonoid-rich apples and nitrate-rich spinach on nitric oxide status, endothelial function, and blood pressure. A randomized, controlled, crossover trial with healthy men and women (n = 30) was conducted. The acute effects of four energy-matched treatments (control, apple, spinach, and apple + spinach), administered in random order, were compared. Measurements included plasma nitric oxide status, assessed by measuring S-nitrosothiols + other nitrosylated species (RXNO) and nitrite, blood pressure, and endothelial function, measured as flow-mediated dilatation of the brachial artery. Results are means and 95% CI. Relative to control, all treatments resulted in higher RXNO (control, 33 nmol/L, 26, 42; apple, 51 nmol/L, 40, 65; spinach, 86 nmol/L, 68, 110; apple + spinach, 69 nmol/L, 54, 88; P b 0.01) and higher nitrite (control, 35 nmol/L, 27, 46; apple, 69 nmol/L, 53, 90; spinach, 99 nmol/L, 76, 129; apple + spinach, 80 nmol/L, 61, 104; P b 0.01). Compared to control, all treatments resulted in higher flow-mediated dilatation (P b 0.05) and lower pulse pressure (P b 0.05), and apple and spinach resulted in lower systolic blood pressure (P b 0.05). No significant effect was observed on diastolic blood pressure. The combination of apple and spinach did not result in additive effects on nitric oxide status, endothelial function, or blood pressure. In conclusion, flavonoid-rich apples and nitrate-rich spinach can independently augment nitric oxide status, enhance endothelial function, and lower blood pressure acutely, outcomes that may benefit cardiovascular health.
A novel, highly sensitive, selective, and simple kinetic method was developed for the determinati... more A novel, highly sensitive, selective, and simple kinetic method was developed for the determination of Mo(VI) based on its catalytic effect on the oxidation of 1-amino-2-naphthol-4-sulfonic acid (ANSA) with H 2 O 2 . The reaction was followed spectrophotometrically by tracing the oxidized product at 465 nm after 30 min of mixing the reagents. The optimum reaction conditions were: 10 mmol l −1 ANSA, 50 mmol l −1 H 2 O 2 , 100 mmol l −1 acetate buffer of pH 5.0 ± 0.05 and at 40 • C. Addition of 200 g ml −1 diethylenetriaminepentaacetic acid (DTPA) conferred high selectivity for the proposed method. Following the recommended procedure, Mo(VI) could be determined with a linear calibration graph up to 2.5 ng ml −1 and a detection limit, based on the 3S b -criterion, of 0.027 ng ml −1 . The unique sensitivity and selectivity of the implemented method allowed its direct application to the determination of Mo(VI) in natural and industrial waste water. The method was validated by comparison with the standard ETAAS method. Moreover, published catalytic-spectrophotometric methods for the determination of molybdenum were reviewed.
Dietary polyphenols are associated with protection against chronic diseases such as cardiovascula... more Dietary polyphenols are associated with protection against chronic diseases such as cardiovascular disease. Pharmacological studies show a range of bioactivities and efficacy attributable to specific polyphenols. While many fruits are rich in polyphenols, wide cultivar variation of polyphenol composition is common. Our objective was to determine the composition of major bioactive polyphenols in 29 prevarietal selections of Western Australian plums, and Black Amber as an evaluation in developing breeding tools to develop fruit that may have enhanced health-promoting capacities. Total phenolics were quantified colorimetrically; selected polyphenols were quantified by HPLC; and the total antioxidant capacity (TAC) was measured by the antioxidant inhibition of oxygen radicals (AIOR) assay. Total phenolic concentration was significantly correlated with TAC (R = 0.95, P < 0.01). Neo-chlorogenic acid and quercetin glycosides were found to be the predominant polyphenols (mean 29.9 mg·kg −1 and 50.7 mg·kg −1 , respectively). No significant correlations were found between the composition of predominant polyphenols in plums and the TAC. We argue that the value of in vitro TAC assays to breeding programs may be limited, and future research should focus on the heritability of known bioactive polyphenols.
In order to advise regarding the religious practice of withholding food, we studied the metabolic... more In order to advise regarding the religious practice of withholding food, we studied the metabolic changes after successive 15 days of recurrent fasting of 13 hours every day in maternal plasma and liquor amnii of obese normal gravids and gestational diabetics in their third trimester. There were no significant differences between those who fasted that period for one day prior to elective cesarean section (CS) and those who fasted the same period repeatedly for 15 days. The fasted gravids had significant rises in glycerol, beta-hydroxybutyrate (BOHB) and nonesterified fatty acids (NEFA) (P less than 0.0001, P less than 0.005 and P less than 0.01, respectively) in maternal plasma, compared to unfasted gravid groups and ungravid fasted group. No significant metabolic difference was found in the liquor amnii withdrawn from fasted and unfasted groups. The influence of such short term of starvation on the fetal metabolic profile was studied in the cord blood during cesarean section (CS). Glucose, glycerol and NEFA were significantly lower in arterial than in venous cord plasma (P less than 0.05, P less than 0.01 and P less than 0.01, respectively) indicating that the fetus could utilize these substrates. Positive correlation was found between the levels of BOHB in the mother and venous cord plasma on the one hand and their levels in the arterial cord plasma and liquor amnii on the other hand implying that this substrate passes unutilized through the fetus to the liquor amnii. A pregnant woman in the third trimester should not withhold food for long periods.
Titanium nitride (TiN) widely used as hard coating material, was coated on tool steels, namely on... more Titanium nitride (TiN) widely used as hard coating material, was coated on tool steels, namely on high-speed steel (HSS) and D2 tool steel by physical vapor deposition method. The study concentrated on cathodic arc physical vapor deposition (CAPVD), a technique used for the deposition of hard coatings for tooling applications, and which has many advantages. The main drawback of this technique, however, is the formation of macrodroplets (MDs) during deposition, resulting in films with rougher morphology. Various standard characterization techniques and equipment, such as electron microscopy, atomic force microscopy, hardness testing machine, scratch tester, and pin-on-disc machine, were used to analyze and quantify the following properties and parameters: surface morphology, thickness, hardness, adhesion, and coefficient of friction (COF) of the deposited coatings. Surface morphology revealed that the MDs produced during the etching stage, protruded through the TiN film, resulting in film with deteriorated surface features. Both coating thickness and indentation loads influenced the hardness of the deposited coatings. The coatings deposited on HSS exhibit better adhesion compared to those on D2 tool steel. Standard deviation indicates that the coating deposited with thickness around 6.7 µm showed the most stable trend of COF versus sliding distance.
... Titre du document / Document title. Modification of wood surface by UV curing of epoxy materi... more ... Titre du document / Document title. Modification of wood surface by UV curing of epoxy material. Auteur(s) / Author(s). KHAN Mubarak A. (1) ; RAHMAN Mokhlesur (1) ; IDRISSALI KM (1) ; Affiliation(s) du ou des auteurs / Author(s) Affiliation(s). ...
Pneumococcal carriage is common in children that may account for the high incidence of disease in... more Pneumococcal carriage is common in children that may account for the high incidence of disease in this age group. Recent studies in animals suggest an important role for CD4 þ Tcells, T helper type 17 (Th17) cells in particular, in pneumococcal clearance. Whether this Th17-mediated mechanism operates in humans and what pneumococcal components activate Th17 are unknown. We investigated the ability of domain 4 pneumolysin (D4Ply) to activate CD4 þ Tcells including Th17 in human nasopharynx-associated lymphoid tissue (NALT) and peripheral blood. We show that D4Ply elicited a prominent CD4 þ T-cell proliferative response. More importantly, D4Ply elicited a significant memory Th17 response in NALT, and a moderate response in peripheral blood mononuclear cells (PBMCs). This D4Ply-elicited memory Th17 response was more marked in carriage À than in carriage þ children in both NALTand PBMCs. In contrast, no difference was shown in D4Plyinduced Th1 response between the two groups. We also show D4Ply activated human monocytes and murine macrophages that was in part dependent on Toll-like receptor 4 (TLR-4). Our results support a protective role of Th17 against pneumococcal carriage in human nasopharynx, and identify a novel property of D4Ply to activate Th17 in NALT that may offer an attractive vaccine candidate in intranasal immunization against pneumococcal infection.
... Permissions & Reprints. The mutual solubilities of water with supercritical and liquid ca... more ... Permissions & Reprints. The mutual solubilities of water with supercritical and liquid carbon dioxides *1. MB King * , A. Mubarak , JD Kim and TR Bott. School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK. ...
... SR Foltyn, EJ Peterson, JY Coulter, PN Arendt, QX Jia, PC Dowden, MP Maley, XD Wu, and DE Pet... more ... SR Foltyn, EJ Peterson, JY Coulter, PN Arendt, QX Jia, PC Dowden, MP Maley, XD Wu, and DE Peterson Superconductivity Technology Center ... A change in c-axis lattice parameter suggests that possible causes for this degradation are oxygen deficiency or cation disorder with ...
Flavonoids and nitrates in fruits and vegetables may protect against cardiovascular disease. Diet... more Flavonoids and nitrates in fruits and vegetables may protect against cardiovascular disease. Dietary flavonoids and nitrates can augment nitric oxide status via distinct pathways, which may improve endothelial function and lower blood pressure. Recent studies suggest that the combination of flavonoids and nitrates can enhance nitric oxide production in the stomach. Their combined effect in the circulation is unclear. Here, our objective was to investigate the independent and additive effects of flavonoid-rich apples and nitrate-rich spinach on nitric oxide status, endothelial function, and blood pressure. A randomized, controlled, crossover trial with healthy men and women (n = 30) was conducted. The acute effects of four energy-matched treatments (control, apple, spinach, and apple + spinach), administered in random order, were compared. Measurements included plasma nitric oxide status, assessed by measuring S-nitrosothiols + other nitrosylated species (RXNO) and nitrite, blood pressure, and endothelial function, measured as flow-mediated dilatation of the brachial artery. Results are means and 95% CI. Relative to control, all treatments resulted in higher RXNO (control, 33 nmol/L, 26, 42; apple, 51 nmol/L, 40, 65; spinach, 86 nmol/L, 68, 110; apple + spinach, 69 nmol/L, 54, 88; P b 0.01) and higher nitrite (control, 35 nmol/L, 27, 46; apple, 69 nmol/L, 53, 90; spinach, 99 nmol/L, 76, 129; apple + spinach, 80 nmol/L, 61, 104; P b 0.01). Compared to control, all treatments resulted in higher flow-mediated dilatation (P b 0.05) and lower pulse pressure (P b 0.05), and apple and spinach resulted in lower systolic blood pressure (P b 0.05). No significant effect was observed on diastolic blood pressure. The combination of apple and spinach did not result in additive effects on nitric oxide status, endothelial function, or blood pressure. In conclusion, flavonoid-rich apples and nitrate-rich spinach can independently augment nitric oxide status, enhance endothelial function, and lower blood pressure acutely, outcomes that may benefit cardiovascular health.
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