Atomic-resolution spectroscopic imaging of ensembles of nanocatalyst particles across the life of a fuel cell

The thousandfold increase in data-collection speed enabled by aberration-corrected optics allows us to overcome an electron microscopy paradox - how to obtain atomic-resolution chemical structure in individual nanoparticles, yet record a statistically significant sample from an inhomogeneous population. This allowed us to map hundreds of Pt-Co nanoparticles to show atomic-scale elemental distributions across different stages of the catalyst aging in a proton-exchange-membrane fuel cell, and relate Pt-shell thickness to treatment, particle size, surface orientation, and ordering.Comment: 28 pages, 5 figures, accepted, nano letter

Safety of 3 different reintroduction regimens of antituberculosis drugs after development of antituberculosis treatment-induced hepatotoxicity

Background: Drug-induced hepatotoxicity (DIH) is the most common adverse drug reaction leading to interruption of antituberculosis treatment. Worldwide, different reintroduction regimens have been advocated, but no consensus guidelines are available. Reintroduction of antituberculosis drugs in patients with DIH has never been studied systematically. We aimed to compare the safety of 3 different reintroduction regimens of antituberculosis drugs in patients with antituberculosis DIH. Methods: A total of 175 patients with a diagnosis of antituberculosis DIH were randomized to receive 1 of 3 different predefined reintroduction regimens of antituberculosis drugs and were evaluated prospectively. Patients in arm I were given isoniazid, rifampicin, and pyrazinamide simultaneously at full dosage from day 1. In arm II, drugs were administered in a manner similar to that recommended in the American Thoracic Society guidelines for reintroduction. In arm III, drugs were administered in accordance with British Thoracic Society guidelines. Results: Nineteen patients (10.9%) had recurrence of DIH during follow-up. Eight, 6, and 5 patients had recurrence of hepatitis in arms I, II, and III, respectively (P=.69). Of all the clinical and laboratory parameters, pretreatment serum albumin level was the only statistically significant predictor of future recurrence of DIH on reintroduction of antituberculosis drugs (P<.01). Conclusions: The recurrence rate of hepatotoxicity was not significantly different between the 3 groups. According to the findings of the present study, all 3 of the potentially hepatotoxic drugs (isoniazid, rifampicin, and pyrazinamide) can be reintroduced simultaneously at full dosage safely from day 1, especially for patients with bilateral extensive pulmonary tuberculosis, to halt disease transmission or to treat patients with life-threatening tuberculosis

Atomic-Resolution Spectroscopic Imaging of Ensembles of Nanocatalyst Particles Across the Life of a Fuel Cell

The thousand-fold increase in data-collection speed enabled by aberration-corrected optics allows us to overcome an electron microscopy paradox: how to obtain atomic-resolution chemical structure in individual nanoparticles yet record a statistically significant sample from an inhomogeneous population. This allowed us to map hundreds of Pt–Co nanoparticles to show atomic-scale elemental distributions across different stages of the catalyst aging in a proton-exchange-membrane fuel cell, and relate Pt–shell thickness to treatment, particle size, surface orientation, and ordering