Low-temperature synthesis of ZrB2 powder from oxides using Na

ZrB2 was synthesized by heating a mixture of ZrO2, B2O3, and Na in a molar ratio of 1:1:5 at 873–1273 K. While unreacted ZrO2 remained in the sample synthesized at 873 K, single phase ZrB2 powders were obtained at temperatures ≥1073 K. The diameters of the ZrB2 particles obtained at 1073 and 1273 K were 0.1–20 and 10–100 μm, respectively. Single phase ZrB2 was also obtained at 873 K when the starting material was rich in B2O3 and Na (ZrO2:B2O3:Na = 1:5:15). This route yielded fine particle aggregates of ZrB2, which were found to be <0.1 μm in size

Spinal cord injury without radiological abnormality due to a fall while using an abdominal roller: A report of two cases

Abstract Background In recent years, various home‐use health devices have gained popularity. The abdominal roller is one of these. Spinal cord injury without radiological abnormality is known to occur even with relatively minor injuries, but there are few reports of such injuries caused by a roller. Case Presentation Two cases of spinal cord injuries caused by a roller are reported. In both cases, injuries occurred during the standing rollout by a patient in an inebriated state, and the patients were rushed to an emergency department. Conclusion Because the use of abdominal rollers may result in extremely serious disabilities, it is necessary to emphasize the appropriate use of such equipment

Method for Enhancing Cell Penetration of Gd³⁺-based MRI Contrast Agents by Conjugation with Hydrophobic Fluorescent Dyes

Gadolinium ion (Gd³⁺) complexes are commonly used as magnetic resonance imaging (MRI) contrast agents to enhance signals in <i>T</i>₁-weighted MR images. Recently, several methods to achieve cell-permeation of Gd³⁺ complexes have been reported, but more general and efficient methodology is needed. In this report, we describe a novel method to achieve cell permeation of Gd³⁺ complexes by using hydrophobic fluorescent dyes as a cell-permeability-enhancing unit. We synthesized Gd³⁺ complexes conjugated with boron dipyrromethene (<b>BDP-Gd</b>) and Cy7 dye (<b>Cy7-Gd</b>), and showed that these conjugates can be introduced efficiently into cells. To examine the relationship between cell permeability and dye structure, we further synthesized a series of <b>Cy7-Gd</b> derivatives. On the basis of MR imaging, flow cytometry, and ICP-MS analysis of cells loaded with <b>Cy7-Gd</b> derivatives, highly hydrophobic and nonanionic dyes were effective for enhancing cell permeation of Gd³⁺ complexes. Furthermore, the behavior of these <b>Cy7-Gd</b> derivatives was examined in mice. Thus, conjugation of hydrophobic fluorescent dyes appears to be an effective approach to improve the cell permeability of Gd³⁺ complexes, and should be applicable for further development of Gd³⁺-based MRI contrast agents