2-(2,6-Dimethoxy­phen­yl)-5-hydr­oxy-7-meth­oxy-4H-1-benzopyran-4-one

In the title compound, C18H16O6, the dimethoxy­phenyl ring is rotated by 61.8 (1)° from the plane of the benzopyran system. The mol­ecule is stabilized by an intra­molecular O—H⋯O hydrogen bond

Biomaterials-enabled cornea regeneration in patients at high risk for rejection of donor tissue transplantation

The severe worldwide shortage of donor organs, and severe pathologies placing patients at high risk for rejecting conventional cornea transplantation, have left many corneal blind patients untreated. Following successful pre-clinical evaluation in mini-pigs, we tested a biomaterials-enabled pro-regeneration strategy to restore corneal integrity in an open-label observational study of six patients. Cell-free corneal implants comprising recombinant human collagen and phosphorylcholine were grafted by anterior lamellar keratoplasty into corneas of unilaterally blind patients diagnosed at high-risk for rejecting donor allografts. They were followed-up for a mean of 24 months. Patients with acute disease (ulceration) were relieved of pain and discomfort within 1-2 weeks post-operation. Patients with scarred or ulcerated corneas from severe infection showed better vision improvement, followed by corneas with burns. Corneas with immune or degenerative conditions transplanted for symptom relief only showed no vision improvement overall. However, grafting promoted nerve regeneration as observed by improved touch sensitivity to normal levels in all patients tested, even for those with little/no sensitivity before treatment. Overall, three out of six patients showed significant vision improvement. Others were sufficiently stabilized to allow follow-on surgery to restore vision. Grafting outcomes in mini-pig corneas were superior to those in human subjects, emphasizing that animal models are only predictive for patients with non-severely pathological corneas; however, for establishing parameters such as stable corneal regeneration and nerve regeneration, our pig model is satisfactory. While further testing is merited, we have nevertheless shown that cell-free implants are potentially safe, efficacious options for treating high-risk patients

Effect of Al2TiO5 powder coating on the tribological, corrosion and mechanical properties of AISI 316L stainless steel

The aim of the current research is to examine the tribological, corrosion and mechanical properties of AISI 316L stainless steel without and with Al _2 TiO _5 surface coating. AISI 316L is selected for the study, owing to its extensive usage in power plant and marine members that are usually subjected to wear, fatigue and corrosion either separately or in a combinatorial mode from mild to severe intensities. Al _2 TiO _5 coating is provided to components to improve their tribological, corrosion and mechanical properties. Being a ceramic material, Al _2 TiO _5 coating is expected to improve the properties under consideration. The coated specimens are analyzed by considering two factors viz. ‘speed of rotation of job’ and ‘axial speed of the spray gun’, applying Taguchi L _4 array. Coating of Al _2 TiO _5 on AISI 316L substrate increased the corrosion resistance, coefficient of friction and micro-hardness, however the wear rate and fatigue life decreased. Twenty times reduction in wear rate is recorded with the coating of Al _2 TiO _5 on the base material when compared to the uncoated counterpart. The wear rate has also decreased by 16% with the increase in coating thickness from 300 to 375 μ m. The fatigue life of the coated specimens reduced by around 12% while their corrosion resistance increased by 20% when compared to the uncoated specimens