Elucidating the performance benefits enabled by YSZ/Ni-YSZ bilayer thin films in a porous anode-supported cell architecture.

Increasing the performance and improving the stability of solid oxide cells are critical requirements for advancing this technology toward commercial applications. In this study, a systematic comparison of anode-supported cells utilizing thin films with those utilizing conventional screen-printed yttria-stabilized zirconia (YSZ) is performed. High-resolution secondary ion mass spectrometry (SIMS) imaging is used to visualize, for the first time, the extent of Ni diffusion into screen-printed microcrystalline YSZ electrolytes of approximately 2-3 µm thickness, due to the high temperature (typically >1300 °C) used in the conventional sintering process. As an alternative approach, dense YSZ thin films and Ni(O)-YSZ nanocomposite layers are prepared using pulsed laser deposition (PLD) at a relatively low temperature of 750 °C. YSZ thin films exhibit densely packed nanocrystalline grains and a remarkable suppression of Ni diffusion, which are further associated with some reduction in the ohmic resistance of the cell, especially in the low temperature regime. Moreover, the use of a Ni-YSZ nanocomposite layer resulted in improved contact at the YSZ/anode interface as well as a higher density of triple phase boundaries due to the nanoscale Ni and YSZ grains being homogeneously distributed throughout the structure. The cells utilizing the YSZ/Ni-YSZ bilayer thin films show excellent performance in fuel cell operation and good durability in short-term operation up to 65 hours. These results provide insights into ways to improve the electrochemical performance of SOCs by utilizing innovative thin film structures in conjunction with commercially viable porous anode-supported cells.

Nanocomposite electrodes for high current density over 3 A cm-2 in solid oxide electrolysis cells.

Solid oxide electrolysis cells can theoretically achieve high energy-conversion efficiency, but current density must be further increased to improve the hydrogen production rate, which is essential to realize widespread application. Here, we report a structure technology for solid oxide electrolysis cells to achieve a current density higher than 3 A cm-2, which exceeds that of state-of-the-art electrolyzers. Bimodal-structured nanocomposite oxygen electrodes are developed where nanometer-scale Sm0.5Sr0.5CoO3-δ and Ce0.8Sm0.2O1.9 are highly dispersed and where submicrometer-scale particles form conductive networks with broad pore channels. Such structure is realized by fabricating the electrode structure from the raw powder material stage using spray pyrolysis. The solid oxide electrolysis cells with the nanocomposite electrodes exhibit high current density in steam electrolysis operation (e.g., at 1.3 V), reaching 3.13 A cm-2 at 750 °C and 4.08 A cm-2 at 800 °C, corresponding to a hydrogen production rate of 1.31 and 1.71 L h-1 cm-2 respectively.

Correlation between Dissolved Protons in Nickel-Doped BaZr0.1Ce0.7Y0.1Yb0.1O3-δ and Its Electrical Conductive Properties.

The electrical conductivity of nickel (2 wt %)-doped BaZr0.1Ce0.7Y0.1Yb0.1O3-δ (BZCYYb) acceptor-doped perovskite oxide was evaluated under air and a 1% H2 atmosphere. The partial conductivity was calculated from the total conductivity and the transport number of each carrier (tH+, tO2-, and th+) obtained using the concentration cell method. Its correlation with the dissolution state of the protons in the oxide as studied by in situ diffuse reflection Fourier transform infrared spectroscopy is discussed. When the concentration of protons that dissolved in BZCYYb-Ni was high, the proton partial conductivity was also high. An increase in hole conductivity in the high-temperature region in an air atmosphere was observed, suggesting that dissociation of protons strongly correlates with such a dominant carrier change. The dissociation of protons should be determined by the stability of protons in the oxide by the interaction with the lattice oxygen, and it was suggested that the dissolution state of protons can be controlled by modifying such stability in the oxide.

[Patient-controlled epidural analgesia combined with patient-controlled intravenous analgesia for postoperative analgesia after Miles' operation for rectal cancer].

A 69-year-old woman (156 cm, 53 kg) underwent a Miles' operation, total hysterectomy, resection of vagina, and thigh flap to vulva for rectal cancer. Before general anesthesia, an epidural catheter was inserted at T11-12 interspace, and 1.5% mepivacaine 7ml was administered. Sensory block level spread from T4 to L1. Anesthesia was induced with propofol and maintained with sevoflurane in air oxygen mixture. Operation was performed uneventfully. After the operation, postoperative analgesia was achieved with patient-controlled epidural analgesia (PCEA). The epidural solution of 0.06% ropivacaine with 4 microg x ml(-1) fentanyl and 20 microg x ml(-1) was connected to a PCA pump (i-Fuser, JMS, Japan) that was programmed as an 8 ml initial bolus, 4 ml x hr(-1) basal infusion, 2 ml bolus dose, and 10-min lockout interval. Although abdominal pain was well controlled by PCEA, intractable pain in the pelvic nerve region existed. Patient-controlled intravenous analgesia (IV-PCA) with fentanyl, ketamine, and lidocaine was added to PCEA. Then excellent pain relief was obtained without any side effects such as nausea, vomiting, drowsiness, and respiratory depression. It could be useful to use IV-PCA together with PCEA when wide spread postoperative analgesia is necessary.

Regional cerebral blood flow in healthy volunteers measured by the graph plot method with iodoamphetamine SPECT.

PURPOSE: The graph plot method, a technique that uses N-isopropyl-(123)I-p-iodoamphetamine (IMP) and single photon emission computed tomography (SPECT) for non-invasive measurement of regional cerebral blood flow (CBF), has been developed and applied in the clinical setting, although it has been performed without obtaining normal CBF values in normal, healthy subjects. The aim of this study was to measure normal regional CBF in older healthy subjects with IMP SPECT and the graph plot method. SUBJECTS AND METHODS: Eleven healthy volunteers (mean age: 63.5 ± 8.9 years; six males and five females) were recruited and regional CBF was measured using IMP SPECT and the graph plot method. RESULTS: The averaged global CBF was 45.4 ml/100 g/min. The distribution of regional CBF was almost homogenous in the cortices. There was no significant correlation between the global CBF and age in subjects aged 50-80 years. CONCLUSION: We used the IMP graph plot method to measure regional CBF in normal healthy subjects, without arterial blood sampling, and obtained compatible CBF values. This method is non-invasive and convenient for determination of regional CBF in the clinical setting.

Impact of anode microstructure on solid oxide fuel cells.

We report a correlation between the microstructure of the anode electrode of a solid oxide fuel cell (SOFC) and its electrochemical performance for a tubular design. It was shown that the electrochemical performance of the cell was extensively improved when the size of constituent particles was reduced so as to yield a highly porous microstructure. The SOFC had a power density of greater than 1 watt per square centimeter at an operating temperature as low as 600 degrees C with a conventional zirconia-based electrolyte, a nickel cermet anode, and a lanthanum ferrite perovskite cathode material. The effect of the hydrogen fuel flow rate (linear velocity) was also examined for the optimization of operating conditions. Higher linear fuel velocity led to better cell performance for the cell with higher anode porosity. A zirconia-based cell could be used for a low-temperature SOFC system under 600 degrees C just by optimizing the microstructure of the anode electrode and operating conditions.

Usefulness of a breath-holding acquisition method in PET/CT for pulmonary lesions.

OBJECTIVE: To evaluate the usefulness of a breath-holding (BH) (18)F-2-fluoro-2-deoxy-D-glucose positron emission tomography ((18)F-FDG-PET) technique for PET/computed tomography (CT) scanning of pulmonary lesions near the diaphragm, where image quality is influenced by respiratory motion. METHODS: In a basic study, simulated breath-holding PET (sBH-PET) data were acquired by repeating image acquisition eight times with fixation of a phantom at 15 s/bed. Free-breathing PET (FB-PET) was simulated by acquiring data even as moving the phantom at 120 s/bed (sFB-PET). Images with total acquisition times of 15 s, 30 s, 45 s, 60 s, and 120 s were generated for sBHPET. Receiver-operating characteristic (ROC) analyses and determination of the statistical significance of differences between sFB-PET images and sBH-PET images were performed. A total of 22 pulmonary lesions in 21 patients (12 men and 9 women, mean age 61.3 +/- 10.6 years, 10 benign lesions in 9 patients and 12 malignant lesions in 12 patients) were examined by FB-PET and BH-PET). For evaluation of these two acquisition methods, displacement of the lesion between CT and PET was considered to be a translation, and the statistical significance of differences in maximum standardized uptake value (SUV(max)) of the lesion was assessed using the paired t test. RESULTS: In the basic study, sBH-PET images with acquisition times of 45 s, 60 s, and 120 s had significantly higher diagnostic accuracy than 120-s sFB-PET images (P < 0.05). In clinical cases, translation of the BH-PET images was significantly lower than that of the FB-PET images (benign: 5.29 +/- 4.02 mm vs. 11.79 +/- 8.27 mm, P = 0.005; malignant: 4.29 +/- 3.36 mm vs. 18.26 +/- 12.31 mm, P = 0.003). The SUV(max) of the lesions in the BH-PET images was significantly higher than that in the FB-PET images (benign: 2.40 +/- 0.86 vs. 2.20 +/- 0.85, P = 0.005; malignant: 4.84 +/- 2.16 vs. 3.75 +/- 2.11, P = 0.001). CONCLUSIONS: BH-PET provides images with better diagnostic accuracy, avoids image degradation owing to respiratory motion, and yields more accurate attenuation correction. This method is very useful for overcoming the problem of respiratory motion.

A comparison of three different concentrations of ropivacaine with fentanyl for patient-controlled epidural analgesia.

BACKGROUND: The optimal concentration of ropivacaine in combination with fentanyl for patient-controlled epidural analgesia focusing on preservation of bowel function, analgesia, and motor function remains unclear. METHODS: Three hundred-twelve women scheduled to undergo gynecologic lower abdominal surgery, were randomly allocated to receive ropivacaine 0.05, 0.075, or 0.1% in combination with fentanyl 4 mug/mL and droperidol 25 microg/mL. The settings of patient-controlled epidural analgesia were as follows: initial loading volume 5 mL, background infusion 2 mL/h during night-time, no background infusion during daytime, bolus volume 2 mL, and lockout interval 10 min. Bowel function was evaluated by the first passage of flatus and feces. Pain was assessed with a visual analog scale, and motor function was examined by modified Bromage scale. Data were collected in the evening on the day of surgery, in the morning and in the evening on the first postoperative day, and in the morning on the second postoperative day. RESULTS: Gastrointestinal motility was not different among the three groups. All three solutions produced equivalent analgesia and no motor blockade. CONCLUSION: We conclude that ropivacaine 0.05% is sufficient to preserve gastrointestinal motility, and provides excellent postoperative pain relief without motor blockade.

Nitric oxide-mediated effect of nipradilol, an alpha- and beta-adrenergic blocker, on glutamate neurotoxicity in rat cortical cultures.

Nipradilol (3,4-dihydro-8-(2-hydroxy-3-isopropylamino)propoxy-3-nitroxy-2H-1-benzopyran) is used clinically as an anti-glaucoma ophthalmic solution in Japan, and was recently reported to suppress N-methyl-d-aspartate-induced retinal damage in rats. Here we investigated cytotoxic and cytoprotective actions of nipradilol on primary cultures of rat cortical neurons. Treatment of cortical cultures with a high concentration (500 microM) of nipradilol significantly reduced cell viability, increased lactate dehydrogenase (LDH) release and nitrite concentration in culture medium, whereas desnitro-nipradilol (3,4-dihydro-8-(2-hydroxy-3-isopropylamino)propoxy-3-hydroxy-2H-1-benzopyran) had no significant effects. Nipradilol-induced neuronal damage was inhibited by S-hexylglutathione, a glutathione S-transferase inhibitor, and FeTPPS (5,10,15,20-tetrakis(4-sulfonatophenyl)prophyrinato iron (III) chloride), a peroxynitrite decomposition catalyst. On the other hand, relatively low concentrations (10-100 microM) of nipradilol but not desnitro-nipradilol prevented neuronal cell death induced by 24 h application of 100 microM glutamate. Importantly, neuroprotective concentration (100 microM) of nipradilol suppressed glutamate-induced elevation of intracellular Ca2+ concentrations, but had no effect on intracellular cyclic GMP levels. Hence, nipradilol can protect cultured cortical neurons against glutamate neurotoxicity via cyclic GMP-independent mechanisms, and nitric oxide (NO) released from the nitoroxy moiety of nipradilol may mediate neuroprotective effect through the modulation of NMDA receptor function.

Up-regulation of nicotinic acetylcholine receptors by central-type acetylcholinesterase inhibitors in rat cortical neurons.

We previously reported that donepezil, a central-type acetylcholinesterase inhibitor, showed neuroprotective action via alpha4-and alpha7-nicotinic acetylcholine receptors against glutamate neurotoxicity in rat cortical culture. The present study was performed to investigate whether the neuroprotective action of acetylcholinesterase inhibitors is accompanied by the alteration of expression and function of nicotinic receptors. Four days treatment with acetylcholinesterase inhibitors (10 microM) enhanced the nicotine-induced increase of the intracellular calcium concentration. Immunoblot analysis revealed that donepezil increased both alpha4 and alpha7 subunit proteins. Donepezil and galanthamine increased the number of cells expressing alpha4- and alpha7-nicotinic receptors in immunocytochemical analysis. We examined whether up-regulation of nicotinic receptors affected the neuroprotective action of acetylcholinesterase inhibitors. Under up-regulating conditions, donepezil and galanthamine exerted neuroprotective action at lower concentrations. These results suggest that donepezil and galanthamine up-regulate nicotinic receptors in cortical neurons, and that the up-regulation of nicotinic receptors may make cortical neurons more sensitive to the neuroprotective action of donepezil and galanthamine.

Epidural ropivacaine anesthesia decreases the bispectral index during the awake phase and sevoflurane general anesthesia.

The sedative effects of epidural anesthesia without volatile and IV anesthetics and quantification of the degree of epidural anesthesia-induced sedation have not been investigated. In the current study we evaluated the effects of epidural anesthesia on the bispectral index (BIS) during the awake phase and during general anesthesia. After placing the epidural catheter, the patients were randomly allocated to 2 groups receiving either 5 mL of epidural saline (group S) or the same volume of 0.75% ropivacaine (group R). The BIS measurements during the awake phase were performed at 7, 12, 13, 14, 22, and 23 min after the epidural injection. General anesthesia was then induced with propofol and vecuronium and maintained with 0.75% sevoflurane. From approximately 10 min after tracheal intubation, the BIS measurements were made at 1-min intervals for 10 min. The BIS during the awake phase was significantly lower in group R than in group S (P < 0.05). The BIS during general anesthesia was significantly lower in group R than in group S (P < 0.0001). Epidural anesthesia decreased the BIS during the awake phase and during general anesthesia. The decrease of the BIS associated with epidural anesthesia was more prominent during general anesthesia than during the awake phase.

Molecular epidemiological survey of benign Theileria parasites of cattle in Japan: detection of a new type of major piroplasm surface protein gene.

Benign Theileria species of cattle are found in most parts of the world. The major piroplasm surface protein (MPSP), a conserved protein in all Theileria species, has been used as a maker for epidemiological and phylogenetical studies of benign Theileria species. Parasites with Ikeda- or Chitose-type MPSP genes are dominant in Japan, but we report here mixed infection cases of Theileria parasites with an additional MPSP type parasite infecting cattle in Abashiri District, Hokkaido. The MPSP gene sequence found in the additional type was closely related to MPSP genes of Theileria parasites found in Southeast Asian countries, including Thailand (Narathiwat) and Indonesia (Java). Theileria parasites from the blood sample were also distinguishable from the Ikeda or Chitose type parasites by the small subunit (SSU) rRNA gene sequence analysis, and they are grouped into the SSU rRNA types C/D found in Korea, North America, and Spain. The present finding of mixed infections of cattle with three different types of Theileria makes epidemiological feature of bovine theileriosis in Japan more complex. We have designed a set of primers specific to this MPSP type in order to conduct further epidemiological study.

Glyburide prevents isoflurane's reducing effects on hydroxyl radical formation in the postischemic reperfused rat heart.

BACKGROUND: The role of K(ATP) channels in isoflurane's reducing effects on oxygen free radical formation are not well known. OBJECTIVES: To investigate whether glyburide, an ATP-regulated potassium (K(ATP)) channel blocker, abolishes isoflurane-induced cardioprotective effects and whether it affects hydroxyl radical formation in the postischemic reperfused heart. ANIMALS AND METHODS: Thirty-nine male Wistar rats were divided into four groups: group C (control, n=10), group I (isoflurane, n=9), group G (glyburide, n=10) and group GI (glyburide and isoflurane, n=10). The hearts were perfused as a Neely's working heart model. Afterwards, global heart ischemia was induced for 15 min followed by reperfusion for 20 min. The formation of hydroxyl radicals in the coronary effluent and heart was measured with high performance liquid chromatography. RESULTS: Isoflurane alone and glyburide alone produced significant decreases in the duration of ventricular fibrillation during reperfusion (group C 452+/-345, group I 247+/-60, group G 261+/-135 s; P<0.05). In the presence of glyburide, isoflurane did not further decrease the duration of arrhythmia (group GI 230+/-48 s). Isoflurane reduced hydroxyl radical formation significantly in the coronary effluent during ischemia and reperfusion, but this was prevented by glyburide. CONCLUSION: The results suggest that isoflurane reduces hydroxyl radical formation, at least in part, through activation of K(ATP) channels.

Effects of double administration of nicardipine of the cardiovascular response to tracheal intubation in hypertensive patients.

The efficacy of intravenous nicardipine in attenuating the cardiovascular responses to laryngoscopy and tracheal intubation was studied in 20 hypertensive patients. Ten patients received intravenous 1 mg of nicardipine 1 min before induction (N1 group). The other ten received 1 mg of nicardipine 1 min before induction and an additional 1 mg just before laryngoscopy (N2 group). In the N1 group, arterial pressure and heart rate increased significantly after tracheal intubation. In the N2 group, arterial pressure did not increase but heart rate increased more than that in N1 group. There was no significant difference in rate pressure product between the two groups.