External Fixation Versus ORIF for Distal Intra-articular Tibia Fractures

Tibia plafond fractures have historically demonstrated high complication rates. The purpose of this study was to assess the outcomes of tibia plafond fractures following treatment with definitive external fixation vs delayed open reduction and internal fixation (ORIF). Sixty patients were enrolled in a prospective cohort trial at 1 Level I trauma center. No differences were noted between the 2 treatment groups in terms of age, smoking history, presence of comorbidities, mechanism of injury, incidence of open fractures, or Orthopaedic Trauma Association fracture classification. Complete 12-month follow-up was available for 18 patients in the definitive external fixation group and 27 patients in the ORIF group. No difference was noted in articular reduction between the groups at 6 and 12 months postoperatively. Delayed union or nonunion occurred in 4 (22.2%) of 18 patients in the external fixation group and 1 (3.7%) of 27 patients in the ORIF group (P5.05). Deep infection was equally likely in either group (P5.33). The ORIF group had improved Iowa Ankle Scores at 6 (23.6612.1 vs 11.167.7; P,.05) and 12 months (5.562.2 vs 3.161.7; P,.05) postopertively and improved Short Form-36 Physical Function scores at 6 months (49.7630.1 vs 25.5618.0; P,.05) postoperatively compared with the external fixation group. External fixation and ORIF can attain bony union with adequate articular reduction and similar infection rates. Patients treated with ORIF appeared to have improved union rates and early outcomes with ankle function and Short Form-36 Physical Function scores

The physiology and toxicology of acute inhalation phosphine poisoning in conscious male rats

<p>Phosphine (PH₃) is a toxidrome-spanning chemical that is widely used as an insecticide and rodenticide. Exposure to PH₃ causes a host of target organ and systemic effects, including oxidative stress, cardiopulmonary toxicity, seizure-like activity and overall metabolic disturbance. A custom dynamic inhalation gas exposure system was designed for the whole-body exposure of conscious male Sprague-Dawley rats (250–350 g) to PH₃. An integrated plethysmography system was used to collect respiratory parameters in real-time before, during and after PH₃ exposure. At several time points post-exposure, rats were euthanized, and various organs were removed and analyzed to assess organ and systemic effects. The 24 h post-exposure LCt₅₀, determined by probit analysis, was 23,270 ppm × min (32,345 mg × min/m³). PH₃ exposure affects both pulmonary and cardiac function. Unlike typical pulmonary toxicants, PH₃ induced net increases in respiration during exposure. Gross observations of the heart and lungs of exposed rats suggested pulmonary and cardiac tissue damage, but histopathological examination showed little to no observable pathologic changes in those organs. Gene expression studies indicated alterations in inflammatory processes, metabolic function and cell signaling, with particular focus in cardiac tissue. Transmission electron microscopy examination of cardiac tissue revealed ultrastructural damage to both tissue and mitochondria. Altogether, these data reveal that in untreated, un-anesthetized rats, PH₃ inhalation induces acute cardiorespiratory toxicity and injury, leading to death and that it is characterized by a steep dose-response curve. Continued use of our interdisciplinary approach will permit more effective identification of therapeutic windows and development of rational medical countermeasures and countermeasure strategies.</p

Coronal Heating as Determined by the Solar Flare Frequency Distribution Obtained by Aggregating Case Studies

Flare frequency distributions represent a key approach to addressing one of the largest problems in solar and stellar physics: determining the mechanism that counter-intuitively heats coronae to temperatures that are orders of magnitude hotter than the corresponding photospheres. It is widely accepted that the magnetic field is responsible for the heating, but there are two competing mechanisms that could explain it: nanoflares or Alfv\'en waves. To date, neither can be directly observed. Nanoflares are, by definition, extremely small, but their aggregate energy release could represent a substantial heating mechanism, presuming they are sufficiently abundant. One way to test this presumption is via the flare frequency distribution, which describes how often flares of various energies occur. If the slope of the power law fitting the flare frequency distribution is above a critical threshold, $\alpha=2$ as established in prior literature, then there should be a sufficient abundance of nanoflares to explain coronal heating. We performed $>$600 case studies of solar flares, made possible by an unprecedented number of data analysts via three semesters of an undergraduate physics laboratory course. This allowed us to include two crucial, but nontrivial, analysis methods: pre-flare baseline subtraction and computation of the flare energy, which requires determining flare start and stop times. We aggregated the results of these analyses into a statistical study to determine that $\alpha = 1.63 \pm 0.03$. This is below the critical threshold, suggesting that Alfv\'en waves are an important driver of coronal heating.Comment: 1,002 authors, 14 pages, 4 figures, 3 tables, published by The Astrophysical Journal on 2023-05-09, volume 948, page 7