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The activities of several flavonoids and the related nonflavonoid compound epicatechin were compared with respect to Cu(II)-induced strand scission of DNA by using two different assays. The same series of compounds was used to study the stoichiometry of Cu(II) reduction in the absence of DNA. The compounds were compared for their ability to generate superoxide, hydrogen peroxide and the Cu(II)-dependent production of hydroxyl radicals. Flavonoids were examined to assess the production of a charge-transfer complex with Cu and the rate of decay of the complexes were compared. All the compounds tested had some ability to cause DNA strand scission in the presence of Cu(II), with myricetin being the most active and galangin the least active. The ability to cause such scission correlated with the rate of decay of the charge-transfer complex, the ability to generate active oxygen species and with the stoichiometry of Cu(II) binding. Analysis of the data in the light of the structural differences between the flavonoids led to a discussion of alternative Cu(II)-sequestering mechanisms. 相似文献
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Syed Fazal Hussein Shah BA 《Pediatric dermatology》2020,37(5):996-999
Toy manufacturer Mattel released a new line of diverse Barbie dolls earlier this year, including dolls with alopecia and vitiligo. The new dolls have been widely celebrated, with both media and dermatologists proposing that the dolls could provide significant benefits for the low self-esteem and societal exclusion suffered by children with similar dermatoses. However, the reality may be very different. Here, we present existing research on the impact of diverse dolls on children’s play and psychology to argue that the dolls’ proposed benefits for children with alopecia and vitiligo are unlikely to materialize; rather, alopecia and vitiligo Barbie could prove more harmful than beneficial. 相似文献
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Elizabeth A. Pinard Samina Fazal Jeffrey M. Schussler 《International urology and nephrology》2013,45(4):1215-1217
We present the first case of documented clot in-transit through a patent foramen ovale (PFO), caused by mechanical thrombectomy of a clotted AV fistula. Embolus after access thrombectomy is a rare, but known complication of the procedure. Paradoxical embolus is likewise a rare consequence of a right-sided clot, embolising to the left-sided circulation in a patient with a PFO. Suspected embolus through a PFO after dialysis access thrombectomy has been reported, but no case has ever documented the clot in-transit through the PFO. 相似文献
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M. M. Quazi M. Ishak A. Arslan M. A. Fazal Farazila Yusof B. S. Sazzad M. Nasir Bashir M. Jamshaid 《RSC advances》2018,8(13):6858
Laser composite surfacing (LCS) is a photon driven manufacturing technology that can be utilized for depositing hybrid metal matrix composite coatings (HMMC) on softer Ti/Al/Mg alloys to enhance their tribo-mechanical properties. LCS offers the advantages of higher directionality, localized microstructural refinement and higher metallurgical bonding between coating and substrate. The current research presents the tribo-mechanical evaluation and characterization of solid lubricant based Ni–WC coatings deposited by LCS on Al–Si piston alloy by varying the concentration of graphite between 5-to-15-weight percentage. The tribological behavior of LCS samples was investigated using a ball-on-plate tribometer. Results indicate that the surface hardness, wear rate and friction coefficient of the Al–Si hypereutectic piston alloy were improved after LCS of graphite based HMMC coatings. The maximum surface hardness of 781Hv was acquired for the Ni–WC coating containing 5 wt% graphite. The friction coefficient of Al–Si under dry sliding conditions was reduced from 0.47 to 0.21. The reduction in the friction coefficient was attributed to the formation of a shearable transfer layer, which prevented delamination and reduced adhesion, abrasion and fatigue cracking.The addition of graphite as solid lubricant has significantly reduced the friction coefficient and wear of a Ni–WC composite coating. 相似文献
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Ayesha Aziz Fazal Ali Khan Geof Wood 《Health research policy and systems / BioMed Central》2015,13(Z1):S56