Tuning of a Hydrogen-Bonded Organic Framework by Liquid-Assisted Mechanosynthesis between Trans-Aconitic Acid and Isonicotinamide.

Cocrystallization of trans-aconitic acid (TACA) and isonicotinamide (INA) using liquid assisted mechanochemical grinding results in a unique supramolecular hydrogen-bonded organic framework (HOF) system encapsulating various organic solvents (liquid guest) with the formation of channel inclusion compounds. Dimension and shape of the framework is dependent on the solvent used during liquid assisted grinding (LAG). Although crystal structure of the cocrystal (TACA) ⋅ (INA) ⋅ (HO)@(INA) has been determined by Single Crystal X-ray diffraction (SCXRD), crystal structures of 3 cocrystal HOFs were determined by microcrystal electron diffraction (MicroED) and synchrotron X-ray diffraction due to lack of suitable single crystal.

Evaluating endoscopic ultrasound-guided tissue acquisition for diagnosis of small pancreatic neuroendocrine neoplasms.

Although small hypervascular tumors are suspected to be pancreatic neuroendocrine tumors (p-NENs), their diagnosis and treatment are challenging. This study evaluated the usefulness of endoscopic ultrasound-guided tissue acquisition (EUS-TA) for diagnosis of small p-NENs. All p-NEN lesions that underwent EUS-TA at our hospital between April 2018 and December 2023 were retrospectively analyzed.

Diatom pyrenoids are encased in a protein shell that enables efficient CO fixation.

Pyrenoids are subcompartments of algal chloroplasts that increase the efficiency of Rubisco-driven CO fixation. Diatoms fix up to 20% of global CO, but their pyrenoids remain poorly characterized. Here, we used in vivo photo-crosslinking to identify pyrenoid shell (PyShell) proteins, which we localized to the pyrenoid periphery of model pennate and centric diatoms, Phaeodactylum tricornutum and Thalassiosira pseudonana.

The unique allosteric property of crocodilian haemoglobin elucidated by cryo-EM.

The principal effect controlling the oxygen affinity of vertebrate haemoglobins (Hbs) is the allosteric switch between R and T forms with relatively high and low oxygen affinity respectively. Uniquely among jawed vertebrates, crocodilians possess Hb that shows a profound drop in oxygen affinity in the presence of bicarbonate ions. This allows them to stay underwater for extended periods by consuming almost all the oxygen present in the blood-stream, as metabolism releases carbon dioxide, whose conversion to bicarbonate and hydrogen ions is catalysed by carbonic anhydrase.