Xenon and Sevoflurane Provide Analgesia during Labor and Fetal Brain Protection in a Perinatal Rat Model of Hypoxia-Ischemia

It is not possible to identify all pregnancies at risk of neonatal hypoxic-ischemic encephalopathy (HIE). Many women use some form of analgesia during childbirth and some anesthetic agents have been shown to be neuroprotective when used as analgesics at subanesthetic concentrations. In this study we sought to understand the effects of two anesthetic agents with presumptive analgesic activity and known preconditioning-neuroprotective properties (sevoflurane or xenon), in reducing hypoxia-induced brain damage in a model of intrauterine perinatal asphyxia. The analgesic and neuroprotective effects at subanesthetic levels of sevoflurane (0.35%) or xenon (35%) were tested in a rat model of intrauterine perinatal asphyxia. Analgesic effects were measured by assessing maternal behavior and spinal cord dorsal horn neuronal activation using c-Fos. In separate experiments, intrauterine fetal asphyxia was induced four hours after gas exposure; on post-insult day 3 apoptotic cell death was measured by caspase-3 immunostaining in hippocampal neurons and correlated with the number of viable neurons on postnatal day (PND) 7. A separate cohort of pups was nurtured by a surrogate mother for 50 days when cognitive testing with Morris water maze was performed. Both anesthetic agents provided analgesia as reflected by a reduction in the number of stretching movements and decreased c-Fos expression in the dorsal horn of the spinal cord. Both agents also reduced the number of caspase-3 positive (apoptotic) neurons and increased cell viability in the hippocampus at PND7. These acute histological changes were mirrored by improved cognitive function measured remotely after birth on PND 50 compared to control group. Subanesthetic doses of sevoflurane or xenon provided both analgesia and neuroprotection in this model of intrauterine perinatal asphyxia. These data suggest that anesthetic agents with neuroprotective properties may be effective in preventing HIE and should be tested in clinical trials in the future

Phase Behavior of Aqueous Na-K-Mg-Ca-CI-NO3 Mixtures: Isopiestic Measurements and Thermodynamic Modeling

A comprehensive model has been established for calculating thermodynamic properties of multicomponent aqueous systems containing the Na{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}, Cl{sup -}, and NO{sub 3}{sup -} ions. The thermodynamic framework is based on a previously developed model for mixed-solvent electrolyte solutions. The framework has been designed to reproduce the properties of salt solutions at temperatures ranging from the freezing point to 300 C and concentrations ranging from infinite dilution to the fused salt limit. The model has been parameterized using a combination of an extensive literature database and new isopiestic measurements for thirteen salt mixtures at 140 C. The measurements have been performed using Oak Ridge National Laboratory's (ORNL) previously designed gravimetric isopiestic apparatus, which makes it possible to detect solid phase precipitation. Water activities are reported for mixtures with a fixed ratio of salts as a function of the total apparent salt mole fraction. The isopiestic measurements reported here simultaneously reflect two fundamental properties of the system, i.e., the activity of water as a function of solution concentration and the occurrence of solid-liquid transitions. The thermodynamic model accurately reproduces the new isopiestic data as well as literature data for binary, ternary and higher-order subsystems. Because of its high accuracy in calculating vapor-liquid and solid-liquid equilibria, the model is suitable for studying deliquescence behavior of multicomponent salt systems

Cost minimization analysis in postoperative pain management. Economic efficiency and effectiveness of two infusion pump systems

Besides reliable efficacy and patient satisfaction, economic efficiency is becoming increasingly more important in postoperative pain management. The present study investigated the effectiveness of two pain pump systems and compared the running costs in treatment. In this study 40 patients received an interscalene catheter prior to shoulder surgery. Postoperative pain management was provided via an electronic pump with patient-controlled analgesia (PCA) or a mechanical pump without PCA. Patients kept a pain log. After treatment they were interviewed about their satisfaction with the pump. In addition drug consumption, nursing material, staff time for handling and maintenance of the pumps and preparation of medications pro re nata were assessed. Postoperative pain levels and patient satisfaction were comparable in both groups. Economically, the electronic pump was more cost-effective than the electronic model for a duration of treatment of 1 and 2 days. With treatment duration of 2 days the costs of both pumps were equivalent; however, the PCA feature of the electronic pump allowed a reduced intake of systemic analgesics on demand. Both pain pump systems provide equally effective pain management, while the electronic model caused less costs. Both pumps offer advantages and disadvantages that should be considered based on local circumstantial demands

Hydrothermal Synthesis, Crystal Structure, and Magnetism of Na₂[Ir(OH)₆] and its Dehydration to Na₂IrO₃

Yellow single-crystals of Na2[Ir(OH)6] were obtained by hydrothermal synthesis in 20 m sodium hydroxide solution at 473 K within 5 hours. X-ray diffraction on a single-crystal revealed the trigonal space group (Formula presented.) (no. 148) with lattice parameters a=582.76(3) pm and c=1399.30(8) pm at 100(1) K. Na2[Ir(OH)6] crystallizes in a hettotype of Mg(OH)2 (brucite) and is isostructural to Na2[Sn(OH)6]. The oxygen atoms are arranged in a hexagonal close packing, Na+ and Ir4+ ions occupy the octahedral voids in every second layer in an ordered manner, the voids of the next layers remain empty. The hydroxidometalate layer can be seen as isolated [Ir(OH)6]2− octahedra, which are embedded in a honeycomb net of alkali metal cations. Temperature-dependent magnetic measurements revealed paramagnetic behavior with an effective moment of 1.9 μB per iridium ion. The thermal decomposition of Na2[Ir(OH)6] in air starts at about 220 °C and results in pure Na2IrO3. © 2021 The Authors. Zeitschrift für anorganische und allgemeine Chemie published by Wiley-VCH Gmb