Activities of flavonoids for the cleavage of DNA in the presence of Cu(II): correlation with generation of active oxygen species.

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.     

“Doll #135 with vitiligo”: Are alopecia and vitiligo Barbie worth the hype?

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.     

Catastrophic paradoxical embolus after hemodialysis access thrombectomy in a patient with a patent foramen ovale

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.     

Mechanical and tribological performance of a hybrid MMC coating deposited on Al–17Si piston alloy by laser composite surfacing technique

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 781H_v 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.     

Who is excluded and how? An analysis of community spaces for maternal and child health in Pakistan

Background

The maternal, newborn, and child health (MNCH) indicators of Pakistan depict the deplorable state of the poor and rural women and children. Many MNCH programmes stress the need to engage the poor in community spaces. However, caste and class based hierarchies and gendered social norms exclude the lower caste poor women from accessing healthcare. To find pathways for improving the lives of the excluded, this study considers the social system as a whole and describes the mechanisms of exclusion in the externally created formal community spaces and their interaction with the indigenous informal spaces.

Methods

The study used a qualitative case study design to identify the formal and informal community spaces in three purposively selected villages of Thatta, Rajanpur, and Ghizer districts. Community perspectives were gathered by conducting 37 focus group discussions, based on participatory rural appraisal tools, with separate groups of women and men. Relevant documents of six MNCH programmes were reviewed and 25 key informant interviews were conducted with programme staff.

Results

We found that lower caste poor tenants and nomadic peasants were excluded from formal and informal spaces. The formal community spaces formed by MNCH programmes across Pakistan included fixed, small transitory, large transitory, and emerging institutional spaces. Programme guidelines mandated selection of community notables in groups/committees and used criteria that prevented registration of nomadic groups as eligible clients. The selection criteria and adverse attitude of healthcare workers, along with inadequacy of programmatic resources to sustain outreach activities also contributed to exclusion of the lower caste poor women from formal spaces. The informal community spaces were mostly gender segregated. Infrequently, MNCH information trickled down from the better-off to the lower caste poor women through transitory interactions in the informal domestic sphere.

Conclusion

A revision of the purpose and implementation mechanisms for MNCH programmes is mandated to transform formal health spaces into sites of equitable healthcare.