Intravenous Infusion of Fentanyl Has No Effect on Blood Concentration of Tacrolimus in Patients Receiving Hematopoietic Stem-Cell Transplantation.

BACKGROUND: Both tacrolimus (TAC) and fentanyl are frequently used in patients receiving allogeneic hematopoietic stem-cell transplantation. A recently published report demonstrated that fentanyl can reduce the total body clearance of TAC; however, most patients in this study were administered concomitantly with azole antifungal agents, which are known to be strong inhibitors of CYP3A. Hence, the exact effect of fentanyl on TAC pharmacokinetics was unclear. In the current study, the authors retrospectively investigated the pharmacokinetic interaction between TAC and fentanyl in patients who were not concomitantly administered drugs that affect TAC metabolism. METHODS: Patients with continuous infusion of TAC and fentanyl after hematopoietic stem-cell transplantation at the Tokyo Medical and Dental University between January 2014 and December 2018 were enrolled. The total body clearance of TAC was compared before and after the initiation or discontinuation of fentanyl. RESULTS: Thirty patients (24 men and 6 women; median age, 11 years) were screened for their eligibility. Twenty-eight patients were enrolled for evaluating the effects of the fentanyl initiation on TAC pharmacokinetics; 2 patients were excluded because of the absence of data related to the TAC blood concentrations or the concomitant use of azole antifungals. Twenty patients were enrolled for investigating the effects of fentanyl discontinuation on TAC pharmacokinetics, whereas 10 patients were excluded because of the absence of data related to the blood concentration of TAC or the additional administration of azole antifungals. Furthermore, the total body clearance of TAC was not significantly affected by the initiation or discontinuation of fentanyl, although there were large interindividual variations. In addition, the results remained the same even when the analysis was performed independently for adults and children. CONCLUSIONS: Intravenous infusion of fentanyl does not affect the pharmacokinetics of TAC.

Formation of polycyclic aromatic hydrocarbons, benzofuran, and dibenzofuran in fuel-rich oxidation of toluene using a flow reactor.

Recently, polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs (OPAHs) have been attracting considerable attention owing to their high toxicity. Understanding their formation mechanism during combustion processes is important to control their emission. However, there are few studies that have quantitatively investigated OPAH formation in the fuel-rich oxidation of hydrocarbons, despite the availability of several studies on PAH formation. In this study, benzofuran and dibenzofuran as OPAHs were quantified in the fuel-rich oxidation of toluene using a flow reactor at atmospheric pressure in a temperature range of 1050-1350 K at equivalence ratios from 3.0 to 12.0 and residence times from 0.2 to 1.5 s. In addition to benzofuran and dibenzofuran, 4 types of monocyclic aromatic hydrocarbons and 19 types of PAHs were also evaluated. The experimental data obtained in this study were compared with those of the ethylene oxidation performed in our previous study. The existing kinetic model for PAH growth was modified based on several theoretical studies to predict the behavior of OPAHs with furan structures. The modified model showed significant improvements in the prediction of benzofuran and dibenzofuran formation. Based on the rate of production and sensitivity analysis using the modified model, the dominant reaction pathways of benzofuran and dibenzofuran were investigated.

Development of a desktop mask charger.

Polypropylene mesh, integrated in N95 respirators and surgical masks that are widely used in the current crisis of COVID-19, filters aerosols via electrostatics in addition to the physical block. However, any contact to water such as storage under high humidity, exposure to exhaling breath, and washing in water removes its charges and thus compromises its filtering efficiency. We developed a desk top device based on a Cockcroft-Walton's voltage multiplier that can restore the electrostatic charge of surgical masks within 1 min and recover the filtering efficiency of the polypropylene mesh from 87% to 97%. The device is easy to operate and safe, thus may be applied for the reuse of surgical masks towards reducing the plastic wastes.