Design principles for reducible metal nitride catalysts are developed and demonstrated for ambient-pressure solar-driven N2 reduction into NH3.

Gaucher disease, the most common lysosomal storage disease, can be treated with enzyme replacement therapy (ERT), in which defective acid-β-glucosidase (GlcCerase) is supplemented by a recombinant, active enzyme. The X-ray structures of recombinant GlcCerase produced in Chinese hamster ovary cells (imiglucerase, Cerezyme®) and in transgenic carrot cells (prGCD) have been previously solved. We now describe the structure and characteristics of a novel form of GlcCerase under investigation for the treatment of Gaucher disease, Gene-ActivatedTM human GlcCerase (velaglucerase alfa). In contrast to imiglucerase and prGCD, velaglucerase alfa contains the native human enzyme sequence. All three GlcCerases consist of three domains, with the active site located in domain III. The distances between the carboxylic oxygens of the catalytic residues, E340 and E235, are consistent with distances proposed for acid–base hydrolysis. Kinetic parameters (Km and Vmax) of velaglucerase alfa and imiglucerase, as well as their specific activities, are similar. However, analysis of glycosylation patterns shows that velaglucerase alfa displays distinctly different structures from imiglucerase and prGCD. The predominant glycan on velaglucerase alfa is a high-mannose type, with nine mannose units, while imiglucerase contains a chitobiose tri-mannosyl core glycan with fucosylation. These differences in glycosylation affect cellular internalization; the rate of velaglucerase alfa internalization into human macrophages is at least 2-fold greater than that of imiglucerase.

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In March 2020, many United States-based parks and protected area (PPA) managers implemented disease control measures (e.g., park and facility closures) in response to the COVID-19 pandemic caused by SARS-CoV-2. This thought-piece considers expected transformations in PPAs during unprecedented circumstances. We employ a challenges and opportunities framework to explain pandemic-induced alterations in visitor accessibility, PPA management, and scientific research. We acknowledge the complex difficulties that visitors, managers, and researchers may experience during pandemics and provide a listing of opportunities that result from these challenges. We suggest that PPA managers explore alternative solutions that maintain recreation access during future times of uncertainty. Maintaining access allows PPAs to continue serving as places for healthy recreation and restoration for park visitors and may create new opportunities for visitors, managers, and researchers. We underline the necessity to include human disease impacts into adaptive management frameworks and the shifting needs for current and prospective research. These details can affect the availability and accessibility of PPAs, how managers approach and adapt to unusual circumstances, and the focus of future recreation research.

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