248 research outputs found

    High Performance Protonic Ceramic Fuel Cells with Acid-Etched Surfaces

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    We focus on the proton-conducting doped - barium zirconate, which has large proton conductivity at intermediate temperature. We found here a phenomenon that acid - etching of the doped barium zirconate in a solution having a specific pH leaves a porous structure on the surface, and demonstrated power generation of hydrogen fuel cell using electroless-plated Pd and Pt on the porously acid-etched electrolyte surface. The short circuit current density of the hydrogen fuel cell was about 430 mA/cm2 at 600°C using thick electrolyte of 500 μm

    Postprandial Hypotension due to a Lack of Sympathetic Compensation in Patients with Diabetes Mellitus.

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    Postprandial hypotension is an important hemodynamic abnormality in diabetes mellitus, but few reports are available on the relationship between autonomic dysfunction and postprandial hypotension. Ten diabetic patients and 10 healthy volunteers were recruited for this study. Postural blood pressure and heart rate changes were measured before lunch, and then the hemodynamic responses to a standardized meal were investigated. Holter electrocardiogram (ECG) monitoring was conducted for assessing spectral powers and time-domain parameters of RR variations. Postural changes from the supine to the upright position decreased the systolic blood pressure of the diabetics from 133(+-)16 to 107(+-)20 mmHg (p<0.01), but did not decrease the systolic blood pressure of the controls. The heart rate remained constant in the diabetics but was increased in the controls. Food ingestion decreased systolic blood pressure in the diabetics, with a maximum reduction of 25(+-)5 mmHg. This decrease was not associated with any changes in the ratio of low frequency to high frequency, and yet the heart rate remained almost constant. Indexes involving parasympathetic tone were not affected. Food ingestion did not affect blood pressure in the control group. These findings suggest that lack of compensatory sympathetic activation is a factor contributing to postprandial hypotension in diabetics, and that parasympathetic drive does not make a significant contribution to this condition

    Prognostic significance of right bundle branch block in patients with acute inferior myocardial infarction

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    There is little information available concerning the influence of right bundle branch block (RBBB) on the prognosis of patients with inferior myocardial infarction (MI). In this study we evaluated the influence of RBBB on the short-term prognosis of patients with inferior MI. Our study subjects were 1,265 hospitalized patients with Q wave MI. Patients were divided into 4 groups based on the presence or absence of RBBB and on the location of the infarction. RBBB was classified into 4 categories according to the timing of its appearance and its duration as new permanent, transient, old and age indeterminate. In-hospital death and pulmonary congestion were observed more frequently in patients with RBBB than in those without RBBB. Moreover, in inferior MI as in anterior MI, in-hospital death and pulmonary congestion occurred more frequently in new permanent RBBB patients than in patients with other types of RBBB. Multivariate regression analysis reveals that new permanent RBBB was a strong independent predictor for an adverse short-term prognosis in patients with inferior MI, as well as in patients with anterior MI. New permanent RBBB during inferior MI is a strong independent predictor for increased in-hospital mortality, regardless of the infarction location.</p

    Influence of Setting Condition on Characteristics of Savonius Hydraulic Turbine with a Shield Plate

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    The aim of this investigation was to improve power performance of Savonius hydraulic turbine utilizing small stream for electric generation. An attempt was made to increase the power coefficient of runner by the use of flat shield plate placed upstream of the runner. The difference of the power coefficient is discussed in relation to clearance between the runner and the bottom wall and the rotation direction of the runner. The flow field around the runner was also examined visually to clarify influences of setting conditions on the power performance. From this study it was found that the power coefficient is achieved for 0.47 by only using a flat shield plate, the increase is up to 80% over the runner without the plate. Moreover, it is the proper condition that clearance ratio is 0.73 in this study.ArticleJOURNAL OF THERMAL SCIENCE. 20(3):224-228 (2011)journal articl

    Sulfur assimilation using gaseous carbonyl sulfideby the soil fungus Trichoderma harzianum

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    Fungi have the capacity to assimilate a diverse range of both inorganic and organic sulfur compounds. It has been recognized that all sulfur sources taken up by fungi are in soluble forms. In this study, we present evidence that fungi can utilize gaseous carbonyl sulfide(COS) for the assimilation of a sulfur compound. We found that the filamentousfungus Trichoderma harzianum strain THIF08, which has constitutively high COS-degrading activity, was able to grow with COS as the sole sulfur source. Cultivation with 34S-labeled COS revealed that sulfur atom from COS was incorporated into intracellular metabolites such as glutathione and ergothioneine. COS degradation by strain THIF08, in which as much of the moisture derived from the agar medium as possible was removed, indicated that gaseous COS was taken up directly into the cell. Escherichia coli transformed with a COS hydrolase (COSase) gene, which is clade D of the β-class carbonic anhydrase subfamily enzyme with high specificity for COS but low activity for CO2 hydration, showed that the COSase is involved in COS assimilation. Comparison of sulfur metabolites of strain THIF08 revealed a higher relative abundance of reduced sulfur compounds under the COS-supplemented condition than the sulfate-supplemented condition, suggesting that sulfur assimilation is more energetically efficient with COS than with sulfate because there is no redox change of sulfur. Phylogenetic analysis of the genes encoding COSase, which are distributed in a wide range of fungal taxa, suggests that the common ancestor of Ascomycota, Basidiomycota, and Mucoromycota acquired COSase at about 790-670 Ma. © 2024 Iizuka et al

    Generation of a Mutant Mucor hiemalis Endoglycosidase That Acts on Core-fucosylated N-Glycans

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    Endo-β-N-acetylglucosaminidase M (Endo-M), an endoglycosidase from the fungus Mucor hiemalis, is a useful tool for chemoenzymatic synthesis of glycoconjugates, including glycoprotein-based therapeutics having a precisely defined glycoform, by virtue of its transglycosylation activity. Although Endo-M has been known to act on various N-glycans, it does not act on core-fucosylated N-glycans, which exist widely in mammalian glycoproteins, thus limiting its application. Therefore, we performed site-directed mutagenesis on Endo-M to isolate mutant enzymes that are able to act on mammalian-type core-α1,6-fucosylated glycans. Among the Endo-M mutant enzymes generated, those in which the tryptophan at position 251 was substituted with alanine or asparagine showed altered substrate specificities. Such mutant enzymes exhibited increased hydrolysis of a synthetic α1,6-fucosylated trimannosyl core structure, whereas their activity on the afucosylated form decreased. In addition, among the Trp-251 mutants, the W251N mutant was most efficient in hydrolyzing the core-fucosylated substrate. W251N mutants could act on the immunoglobulin G-derived core-fucosylated glycopeptides and human lactoferrin glycoproteins. This mutant was also capable of transferring the sialyl glycan from an activated substrate intermediate (sialyl glyco-oxazoline) onto an α1,6-fucosyl-N-acetylglucosaminyl biotin. Furthermore, the W251N mutant gained a glycosynthase-like activity when a N175Q substitution was introduced and it caused accumulation of the transglycosylation products. These findings not only give insights into the substrate recognition mechanism of glycoside hydrolase family 85 enzymes but also widen their scope of application in preparing homogeneous glycoforms of core-fucosylated glycoproteins for the production of potent glycoprotein-based therapeutics

    Suppression of Vortex Precession in a Non-Contact Handling Device by a Circular Column

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    Vortex levitation attains non-contact handling by injecting air through a tangential nozzle into a cylindrical cup generating the swirling flow. The precessing of the swirling flow causes pressure fluctuation. This phenomenon becomes apparent as the gap between the cup and workpiece increases, which significantly disturbs the stability of conveyance. In this paper, suppression of pressure fluctuation by a cylindrical column that stabilizes the vortex levitation is described and its mechanism is mentioned. According to the experimental set up, the pressure was measured at the center of the workpiece and the wall of the cup; velocity field under the work piece was visualized by PIV. The result suggested that the larger diameter column denoted the effect on suppression of the fluctuation because the precessing of the swirling flow became stable. On the other hand, variation of the column thickness had insignificant effect on suppressing the fluctuation, but sucking force became weakened since the swirling velocity decreased.ArticleJournal of Flow Control, Measurement & Visualization. 4:70-78 (2016)journal articl

    Influence of COVID-19 pandemic on bystander interventions, emergency medical service activities, and patient outcomes in out-of-hospital cardiac arrest in Osaka City, Japan

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    Background: The coronavirus disease (COVID-19) pandemic may have negatively affected bystander interventions, emergency medical service (EMS) personnel activities, and patient outcomes after out-of-hospital cardiac arrest (OHCA). This study assessed bystander interventions, EMS activities, and patient outcomes during the COVID-19 pandemic era and compared them with those during the non-COVID-19 pandemic era in Osaka City, Japan, where public-access automated external defibrillators (AEDs) are well established. Methods: We conducted this population-based cohort study that included all cases with non-traumatic OHCA treated by EMS personnel and excluded cases with no resuscitation attempt, traumatic cases, cases occurring in healthcare facilities, or cases witnessed by EMS personnel. Data were compared between the COVID-19 pandemic period (February 1, 2020 to July 31, 2020) and the non-COVID-19 pandemic period (February 1, 2019 to July 31, 2019). Results: During the study periods, 1687 patients were eligible for analyses (COVID-19: n = 825; non-COVID-19: n = 862). Patients with OHCA during the COVID-19 pandemic period were significantly less likely to receive bystander cardiopulmonary resuscitation (CPR) (COVID-19: 33.0%; non-COVID-19: 41.3%; p < 0.001) and public-access AED pad application (COVID-19: 2.9%; non-COVID-19: 6.1%; p = 0.002) compared with patients during the non-COVID-19 pandemic period. There were no significant differences in 1-month survival with favorable neurological outcomes between the two periods (COVID-19: 4.6%; non-COVID-19: 6.1%; p = 0.196). Conclusion: The COVID-19 pandemic period did not affect patient outcomes after OHCA but changed bystander behaviors in Osaka City, Japan

    Association between tranexamic acid administration and mortality based on the trauma phenotype: a retrospective analysis of a nationwide trauma registry in Japan

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    Tachino J., Seno S., Matsumoto H., et al. Association between tranexamic acid administration and mortality based on the trauma phenotype: a retrospective analysis of a nationwide trauma registry in Japan. Critical Care 28, 89 (2024); https://doi.org/10.1186/s13054-024-04871-w.Background: In trauma systems, criteria for individualised and optimised administration of tranexamic acid (TXA), an antifibrinolytic, are yet to be established. This study used nationwide cohort data from Japan to evaluate the association between TXA and in-hospital mortality among all patients with blunt trauma based on clinical phenotypes (trauma phenotypes). Methods: A retrospective analysis was conducted using data from the Japan Trauma Data Bank (JTDB) spanning 2019 to 2021. Results: Of 80,463 patients with trauma registered in the JTDB, 53,703 met the inclusion criteria, and 8046 (15.0%) received TXA treatment. The patients were categorised into eight trauma phenotypes. After adjusting with inverse probability treatment weighting, in-hospital mortality of the following trauma phenotypes significantly reduced with TXA administration: trauma phenotype 1 (odds ratio [OR] 0.68 [95% confidence interval [CI] 0.57–0.81]), trauma phenotype 2 (OR 0.73 [0.66–0.81]), trauma phenotype 6 (OR 0.52 [0.39–0.70]), and trauma phenotype 8 (OR 0.67 [0.60–0.75]). Conversely, trauma phenotypes 3 (OR 2.62 [1.98–3.47]) and 4 (OR 1.39 [1.11–1.74]) exhibited a significant increase in in-hospital mortality. Conclusions: This is the first study to evaluate the association between TXA administration and survival outcomes based on clinical phenotypes. We found an association between trauma phenotypes and in-hospital mortality, indicating that treatment with TXA could potentially influence this relationship. Further studies are needed to assess the usefulness of these phenotypes. Graphical abstract: (Figure presented.

    The DnaA AAA+ Domain His136 Residue Directs DnaB Replicative Helicase to the Unwound Region of the Replication Origin, oriC

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    Chromosomal replication initiation requires dynamic mechanisms in higher-order nucleoprotein complexes that are constructed at the origin of replication. In Escherichia coli, DnaA molecules construct functional oligomers at the origin oriC, enabling localized unwinding of oriC and stable binding of DnaB helicases via multiple domain I molecules of oriC-bound DnaA. DnaA-bound DnaB helicases are then loaded onto the unwound region of oriC for construction of a pair of replisomes for bidirectional replication. However, mechanisms of DnaB loading to the unwound oriC remain largely elusive. In this study, we determined that His136 of DnaA domain III has an important role in loading of DnaB helicases onto the unwound oriC. DnaA H136A mutant protein was impaired in replication initiation in vivo, and in DnaB loading to the unwound oriC in vitro, whereas the protein fully sustained activities for oriC unwinding and DnaA domain I-dependent stable binding between DnaA and DnaB. Functional and structural analyses supported the idea that transient weak interactions between DnaB helicase and DnaA His136 within specific protomers of DnaA oligomers direct DnaB to a region in close proximity to single stranded DNA at unwound oriC bound to DnaA domain III of the DnaA oligomer. The aromatic moiety of His136 is basically conserved at corresponding residues of eubacterial DnaA orthologs, implying that the guidance function of DnaB is common to all eubacterial species
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