Changes in temporal muscle dimensions and their clinical impact in out-of-hospital cardiac arrest survivors.

Objective: This study investigates temporal muscle atrophy in out-of-hospital cardiac arrest patients post-resuscitation, seeking associations with neurological outcomes and factors associated with atrophy. Methods: Using data from six Japanese intensive care units, adult patients' post-resuscitation who underwent head computed tomography scans on admission and two to five days post-admission were assessed. Temporal muscle area, thickness, and density were quantified from a single cross-sectional image. Patients were categorized into 'atrophy' or 'no atrophy' groups based on median daily temporal muscle atrophy rates. The primary outcome was changes in temporal muscle dimensions between admission and follow-up two to five days later. Secondary outcomes included assessing the impact of temporal muscle atrophy on 30-day survival, as well as identifying any clinical factors associated with temporal muscle atrophy. Results: A total of 185 patients were analyzed. Measurements at follow-up revealed significant decreases in temporal muscle area (214 vs. 191 mm2, p < 0.001), thickness (4.9 vs. 4.7 mm, p < 0.001), and density (46 vs. 44 HU, p < 0.001) compared to those at admission. The median daily rate for temporal muscle area atrophy was 2.0% per day. There was no significant association between temporal muscle atrophy and 30-day survival (hazard ratios, 0.71; 95% CI, 0.41-1.23, p = 0.231). Multivariable logistic regression found no clinical factors significantly associated with temporal muscle atrophy. Conclusions: Temporal muscle atrophy in post-resuscitation patients occurs rapidly at 2.0% per day. However, there was no significant association with 30-day mortality or any identified clinical factors. Further investigation into its long-term functional implications is warranted.

Cooperative Spin-State Switching and Vapochromism of Mononuclear Ni(II) Complexes by Pyridine Coordination/Decoordination.

Two mononuclear Ni(II) complexes (1 and 2) have been found to display color changes upon coordination/decoordination of pyridine, resulting in their structural transformation between square-planar and octahedral geometries as well as a change in their spin state. Compound 1 changes between red (1r) and yellow (1y) upon exposure to or elimination of pyridine, while 2 undergoes a two-step transformation, changing orange 2o (S = 0) ⇄ gray 2g' (S = 1) → yellow 2y' (S = 1) depending on the reaction time. The first step (2o → 2g') takes less than 45 min, which is significantly faster than the previously reported reaction time of 1 day for a Ni(II) complex/pyridine vapor system. Compound 2o reacting with pyridine can be easily prepared by dispersing 2g in methanol instead of annealing at high temperatures (130 °C), which can be applied to develop chemical sensors for pyridine utilizing color changes and/or magnetic switching.