General anesthesia for dental treatment in a Williams syndrome patient with severe aortic and pulmonary valve stenosis: suspected episode of postoperatively malignant hyperthermia

A 28-month-old boy (height, 76 cm; weight, 9.4 kg) diagnosed as having Williams syndrome presented for dental care. We report a case of postoperatively suspected malignant hyperthermia after the administration of general anesthesia for dental treatment in this patient with severe supravalvular aortic stenosis and pulmonary artery hypoplasia. Anesthesia was maintained through the inhalation of nitrous oxide and sevoflurane with oxygen. The patient was hemodynamically stable and no other abnormalities were observed. After the completion of the dental treatment, he was transferred to the pediatric ward. On arrival at the ward, the patient's core temperature increased to 39.5 degrees C and tachypnea (RR, 30 breaths/min) was observed. The SPO2 during inhalation was slightly low (92%-93%). Serum biochemistry revealed an elevated CK level (1345 U/L) but no other abnormal findings. Twelve hours after the dental treatment, the patient's core temperature fell to 37.4 degrees C. After hospitalization for 4 days, the patient was discharged in good condition. In the present case, general anesthesia was employed for dental treatment despite severe supravalvular aortic stenosis and peripheral pulmonary artery hypoplasia, because conventional dental therapy was very difficult as a result of the patient's mental retardation and hyperkinesia. The present case suggests that the use of volatile agents that could trigger malignant hyperthermia should be avoided wherever possible.     

Impacts of negatively charged colloidal clay particles on photoisomerization of both anionic and cationic azobenzene molecules

Although smectite-type clays are used as heterogeneous media for photofunctional guest molecules, the guest species are limited to cationic or polar molecules because of the intrinsic negative electric charges of clay particles. Nevertheless, in this study, aqueous clay colloids are reported to affect the photoisomerization kinetics of anionic and cationic azobenzene molecules dissolved in the colloids. Under UV-light irradiation, the clay colloids decelerate trans-to-cis isomerization, while under visible-light irradiation, the clay colloids accelerate cis-to-trans isomerization. In addition, the sol–gel transition of clay colloids affects the kinetics. The results considerably expand the applicability of clay colloids as matrixes for functional organic species.

Aqueous clay colloids influence the photoisomerization kinetics of both of the anionic and cationic azobenzene molecules although the guest species has been limited to cationic or polar molecules because of the intrinsic negative electric charges of the clay particles.     

High capacity all-solid-state lithium battery enabled by in situ formation of an ionic conduction path by lithiation of MgH2

All-solid-state Li batteries have attracted significant attention because of their high energy density and high level of safety. In a solid-state Li-ion battery, the electrodes contain a solid electrolyte that does not contribute directly to the capacity. Therefore, a battery that does not require a solid electrolyte in its electrode mixture should exhibit a higher energy density. In this study, a MgH₂ electrode was used as the negative electrode material without a solid electrolyte in its mixture. The resultant battery demonstrated excellent performance because of the formation of an ionic conduction path based on LiH in the electrode mixture. LiH and Mg clearly formed upon lithiation and returned to MgH₂ upon delithiation as revealed by TEM-EELS analysis. This mechanism of in situ electrolyte formation enables the development of a solid-state battery with a high energy density.

MgH₂ electrode in an all-solid-state battery reversibly operated without solid electrolyte in the electrode mixture.