The Role of Radical Bridges in Polynuclear Single-Molecule Magnets.

Employing radical bridges between anisotropic metal ions has been a viable route to achieve high-performance single-molecule magnets (SMMs). While the bridges have been mainly considered for their ability to promote exchange interactions, the crystal-field effect arising from them has not been taken into account explicitly. This lack of consideration may distort the understanding and limit the development of the entire family. To shed light on this aspect, herein we report a theoretical investigation of a series of N 2 3 - -radical-bridged diterbium complexes. It is found that while promoting strong exchange coupling between the terbium ions, the N 2 3 - -radical induces a crystal field that interferes destructively with that of the outer ligands, and thus reduces the overall SMM behavior. Based on the theoretical results, we conclude that the SMM behavior in this series could be further maximized if the crystal field of the outer ligands is designed to be collinear with that of the radical bridge. This conclusion can be generalized to all exchange-coupled SMMs.

Nonanemic extramedullary hematopoiesis in the posterior mediastinum.

Extramedullary hematopoiesis is a rare condition characterized by the formation of blood cells outside the bone marrow. It is commonly seen in patients with hematopoietic disorders or chronic anemia. Here, we report the case of a 55-year-old patient who had extramedullary hematopoiesis that manifested as an asymptomatic posterior mediastinal mass. Chest computed tomography showed a 30 × 35-mm mass located on the left side of the D11 vertebra. Laboratory investigations revealed no signs of anemia. The tumor was safely and completely removed using video-assisted thoracoscopic surgery. Pathological studies confirmed the extramedullary hematopoiesis nature of the tumor.

Video-assisted thoracoscopic thymectomy for thymoma: a single-center experience.

Background Thymoma is a primary tumor derived from the epithelial cells of the thymus, which is commonly seen in the mediastinum. Surgical thymectomy is the radical treatment for thymoma. The recent introduction of video-assisted thoracoscopic surgery has improved the quality of thymectomy surgery. The clinical characteristics of thymoma and the outcomes of video-assisted thoracoscopic thymectomy in Vietnamese patients are still lacking. The objectives of this study were to investigate the clinical and laboratory characteristics of thymoma and to evaluate the early results of video-assisted thoracoscopic thymectomy for thymoma in Vietnamese patients. Methods All 53 thymoma patients with or without myasthenia gravis who underwent video-assisted thoracoscopic thymectomy in Military Hospital 103, Vietnam, from October 2013 to July 2017 were included. Results The mean age was 46.5 7.1 years, and the female/male ratio was 1.2:1. Myasthenia gravis, mostly stage IIA, was present in 84.9% of patients. There was no hospital mortality or major postoperative complication. The mean operative time was 65 min, intensive care unit stay was 22 ± 5 h, and postoperative hospital stay was 7.5 ± 1.7 days. Conclusion Thoracoscopic thymectomy for thymoma in Vietnamese patients achieved improved cosmesis and was safe for both non-myasthenia gravis and myasthenia gravis patients.

Measurement of blood-brain barrier permeability in acute ischemic stroke using standard first-pass perfusion CT data.

BACKGROUND AND PURPOSE: Increased blood-brain barrier permeability is believed to be associated with complications following acute ischemic stroke and with infarct expansion. Measurement of blood-brain barrier permeability requires a delayed image acquisition methodology, which prolongs examination time, increasing the likelihood of movement artefacts and radiation dose. Existing quantitative methods overestimate blood-brain barrier permeability when early phase CT perfusion data are used. The purpose of this study is to develop a method that yields the correct blood-brain barrier permeability value using first-pass perfusion CT data. METHODS: We acquired 43 CT perfusion datasets, comprising experimental (n = 30) and validation subject groups (n = 13). The Gjedde-Patlak method was used to estimate blood-brain barrier permeability using first-pass (30-60 s after contrast administration) and delayed phase (30-200 s) data. In the experimental group, linear regression was used to obtain a function predicting first-pass blood-brain barrier permeability estimates from delayed phase estimates in each stroke compartment. The reliability of prediction with this function was then tested using data from the validation group. RESULTS: The predicted delayed phase blood-brain barrier permeability was strongly correlated with the measured delayed phase value (r = 0.67 and 0.6 for experimental and validation group respectively; p < 0.01). Predicted and measured delayed phase blood-brain barrier permeability in each stroke compartment were not significantly different in both experimental and validation groups. CONCLUSION: We have developed a method of estimating blood-brain barrier permeability using first-pass perfusion CT data. This predictive method allows reliable blood-brain barrier permeability estimation within standard acquisition time, minimizing the likelihood of motion artefacts thereby improving image quality and reducing radiation dose.