Defining inappropriate thyroid biopsy?-Proposed definition based on clinical evidence and stakeholder engagement.

Purpose: Identify factors that can be used to assess the appropriateness of a thyroid biopsy and propose a pathway to define inappropriate thyroid biopsies in practice.

Methods: We identified factors utilized in clinical guidelines and existing literature to determine the clinical indications for a thyroid biopsy. Subsequently, we assembled a multidisciplinary panel of experts, including patients, clinicians, researchers, and quality experts, to integrate these factors and develop a pathway for assessing the appropriateness of thyroid biopsies.

Synthetic Access to All Four Stereoisomers of Oxetin.

A short synthesis of all four stereoisomers of 3-amino-2-oxetanecarboxylic acid (oxetin) is described. The oxetane core is built using a Paternò-Büchi photochemical [2 + 2] cycloaddition; from the key intermediates, complementary resolution protocols provide access to enantiomerically pure oxetin and epi-oxetin on gram-scale.

Dual organism design cycle reveals small subunit substitutions that improve [NiFe] hydrogenase hydrogen evolution.

Background: Photosynthetic microorganisms that directly channel solar energy to the production of molecular hydrogen are a potential future biofuel system. Building such a system requires installation of a hydrogenase in the photosynthetic organism that is both tolerant to oxygen and capable of hydrogen production. Toward this end, we have identified the [NiFe] hydrogenase from the marine bacterium Alteromonas macleodii "Deep ecotype" that is able to be heterologously expressed in cyanobacteria and has tolerance to partial oxygen.