Acute severe gouty arthritis secondary to isotretinoin toxicity in a young male: a case report.

Acute gouty arthritis is a recognized complication of hyperuricemia and one of the most common forms of inflammatory arthritis in adults. Drug-induced hyperuricemia is increasingly prevalent in clinical practice. Diuretics, antitubercular medications, and immunosuppressants are the common drugs associated with hyperuricemia. Oral isotretinoin is the drug of choice for different forms of severe acne and is rarely associated with hyperuricemia. We present the case of a 30-year-old male with severe acne vulgaris who was prescribed isotretinoin and later presented with acute gout. The patient developed hyperuricemia and swelling of the right first metatarsophalangeal joint within two months of isotretinoin commencement. There was a second episode of similar joint swelling three months later, parallel to the isotretinoin rechallenge. The dose of isotretinoin was reduced with the addition of febuxostat. The patient did not develop further episodes and remained symptom-free without urate-lowering therapy.

Conduction Mechanisms in CVD-Grown Monolayer MoS2 Transistors: From Variable-Range Hopping to Velocity Saturation.

We fabricate transistors from chemical vapor deposition-grown monolayer MoS2 crystals and demonstrate excellent current saturation at large drain voltages (Vd). The low-field characteristics of these devices indicate that the electron mobility is likely limited by scattering from charged impurities. The current-voltage characteristics exhibit variable range hopping at low Vd and evidence of velocity saturation at higher Vd. This work confirms the excellent potential of MoS2 as a possible channel-replacement material and highlights the role of multiple transport phenomena in governing its transistor action.

Fast energy relaxation of hot carriers near the Dirac point of graphene.

We investigate energy relaxation of hot carriers in monolayer and bilayer graphene devices, demonstrating that the relaxation rate increases significantly as the Dirac point is approached from either the conduction or valence band. This counterintuitive behavior appears consistent with ideas of charge puddling under disorder, suggesting that it becomes very difficult to excite carriers out of these localized regions. These results therefore demonstrate how the peculiar properties of graphene extend also to the behavior of its nonequilibrium carriers.

Insulator, semiclassical oscillations and quantum Hall liquids at low magnetic fields.

Magneto-transport measurements are performed on two-dimensional GaAs electron systems to probe the quantum Hall (QH) effect at low magnetic fields. Oscillations following the Shubnikov-de Haas (SdH) formula are observed in the transition from the insulator to QH liquid when the observed almost temperature-independent Hall slope indicates insignificant interaction correction. Our study shows that the existence of SdH oscillations in such a transition can be understood based on the non-interacting model.