219 research outputs found
Computer Simulation of Enhancement of Coerciviy in Nd-Fe-B/(Nd,Dy)-Fe-B Composite Magnets
The coercivity Hc of Nd2Fe14B magnets and Nd2Fe14B/(Nd0.7Dy0.3)2Fe14B composite magnets were calculated by computer simulation based on the micromagnetic theory under assumptions that Nd2Fe14B and (Nd0.7Dy0.3)2Fe14B grains have magnetically deteriorated layers on their surfaces and diffusion of Dy from (Nd0.7Dy0.3)2Fe14B grains to Nd2Fe14B ones through the contacting boundaries recovers the magnetic anisotropy of the deteriorated layers of Nd2Fe14B grains. Hc of Nd2Fe14B/(Nd0.7Dy0.3)2Fe14B composite magnets increased by the diffusion of Dy from (Nd0.7Dy0.3)2Fe14B grains to Nd2Fe14B ones and the resultant recovery of the anisotropy field of deteriorated layers of Nd2Fe14B grains. The Hc vs fraction of (Nd0.7Dy0.3)2Fe14B grains curve were convex for the magnets with the degree of alignment between 0.94 and 0.99, which suggests that the above composite magnets have larger Hc values than the alloy-magnets with the same Dy content, and that we can save the consumption of Dy by using these composite magnets
Effects of exposure to cigarette smoke on intestinal propulsion in rats.
The effects of acute exposure to cigarette smoke and systemic administration of nicotine on intestinal propulsion were investigated in rats. The propulsive activity was measured as migration of charcoal powder in the intestine. This activity was suppressed by acute exposure (10 min) to cigarette smoke and by nicotine (0.5 mg/kg x 2, s.c.) administration. This intestinal suppression was more marked in the rats given nicotine than in those exposed to cigarette smoke, whereas the plasma concentrations of nicotine in both rats were similar. These results suggest that acute exposure to cigarette smoke and nicotine administration delay gastric emptying and/or suppress intestinal propulsion, and that some components other than nicotine contained in cigarette smoke may attenuate the suppression of intestinal propulsion induced by nicotine.</p
Pharmacokinetic Evaluation of Omeprazole Suspension Following Oral Administration in Rats: Effect of Neutralization of Gastric Acid
In order to evaluate a clinical use of omeprazole suspension, we examined the pharmacokinetics of omeprazole after oral administration in rats. Although the administration of omeprazole suspension buffered by NaHCO3 solution did not produce a significant increase in the area under the concentration-time curve (AUC) value compared with non-buffered group, the administration of NaHCO3 buffer immediately after dosing of omeprazole suspension buffered by NaHCO3 caused a significant increase in the AUC value. These results suggest that the NaHCO3 treatment following the administration of omeprazole buffered suspension effectively decreased the degradation of the compound by gastric acid. Therefore, the successive administration of NaHCO3 solution after the omeprazole dosing seems to be a simple and useful method for the administration to patients who cannot receive tablets.</p
Cognitive clustering in schizophrenia patients, their first-degree relatives and healthy subjects is associated with anterior cingulate cortex volume
Cognitive impairments are a core feature in schizophrenia patients (SCZ) and are also observed in first-degree relatives (FR) of SCZ. However, substantial variability in the impairments exists within and among SCZ, FR and healthy controls (HC). A cluster-analytic approach can group individuals based on profiles of traits and create more homogeneous groupings than predefined categories. Here, we investigated differences in the Brief Assessment of Cognition in Schizophrenia (BACS) neuropsychological battery (six subscales) among SCZ, unaffected FR and HC. To identify three homogeneous and meaningful cognitive groups regardless of categorical diagnoses (SCZ, FR and HC), cognitive clustering was performed, and differences in the BACS subscales among the cognitive cluster groups were investigated. Finally, the effects of diagnosis and cognition on brain volumes were examined. As expected, there were significant differences in the five BACS subscales among the diagnostic groups. The cluster-analytic approach generated three meaningful subgroups: (i) neuropsychologically normal, (ii) intermediate impaired and (iii) widespread impaired. The cognitive subgroups were mainly affected by the clinical diagnosis, and significant differences in all BACS subscales among clusters were found. The effects of the diagnosis and cognitive clusters on brain volumes overlapped in the frontal, temporal and limbic regions. Frontal and temporal volumes were mainly affected by the diagnosis, whereas the anterior cingulate cortex (ACC) volumes were affected by the additive effects of diagnosis and cognition. Our findings demonstrate a cognitive continuum among SCZ, FR and HC and support the concept of cognitive impairment and the related ACC volumes as intermediate phenotypes in SCZ
Epitaxially Stabilized EuMoO3: A New Itinerant Ferromagnet
Synthesizing metastable phase often opens new functions in materials but is a
challenging topic. Thin film techniques have advantages to form materials which
do not exist in nature since nonequilibrium processes are frequently utilized.
In this study, we successfully synthesize epitaxially stabilized new compound
of perovskite Eu2+Mo4+O3 as a thin film form by a pulsed laser deposition.
Analogous perovskite SrMoO3 is a highly conducting paramagnetic material, but
Eu2+ and Mo4+ are not compatible in equilibrium and previous study found more
stable pyrochlore Eu23+Mo24+O7 prefers to form. By using isostructural
perovskite substrates, the gain of the interface energy between the film and
the substrate stabilizes the matastable EuMoO3 phase. This compound exhibits
high conductivity and large magnetic moment, originating from Mo 4d2 electrons
and Eu 4f7 electrons, respectively. Our result indi-cates the epitaxial
stabilization is effective not only to stabilize crystallographic structures
but also to from a new compound which contains unstable combinations of ionic
valences in bulk form.Comment: 7 pages, 9 figure
Affleck-Dine baryogenesis with modulated reheating
Modulated reheating scenario is one of the most attractive models that
predict possible detections of not only the primordial non-Gaussianity but also
the tensor fluctuation through future CMB observations such as the Planck
satellite, the PolarBeaR and the LiteBIRD satellite experiments. We study the
baryonic-isocurvature fluctuations in the Affleck-Dine baryogenesis with the
modulated reheating scenario. We show that the Affleck-Dine baryogenesis can be
consistent with the modulated reheating scenario with respect to the current
observational constraint on the baryonic-isocurvature fluctuations.Comment: 7 page
Ras signaling directs endothelial specification of VEGFR2+ vascular progenitor cells
Vascular endothelial growth factor receptor 2 (VEGFR2) transmits signals of crucial importance to vasculogenesis, including proliferation, migration, and differentiation of vascular progenitor cells. Embryonic stem cell–derived VEGFR2+ mesodermal cells differentiate into mural lineage in the presence of platelet derived growth factor (PDGF)–BB or serum but into endothelial lineage in response to VEGF-A. We found that inhibition of H-Ras function by a farnesyltransferase inhibitor or a knockdown technique results in selective suppression of VEGF-A–induced endothelial specification. Experiments with ex vivo whole-embryo culture as well as analysis of H-ras−/− mice also supported this conclusion. Furthermore, expression of a constitutively active H-Ras[G12V] in VEGFR2+ progenitor cells resulted in endothelial differentiation through the extracellular signal-related kinase (Erk) pathway. Both VEGF-A and PDGF-BB activated Ras in VEGFR2+ progenitor cells 5 min after treatment. However, VEGF-A, but not PDGF-BB, activated Ras 6–9 h after treatment, preceding the induction of endothelial markers. VEGF-A thus activates temporally distinct Ras–Erk signaling to direct endothelial specification of VEGFR2+ vascular progenitor cells
Expectant management of a herniated amniotic sac presenting as silent uterine rupture: a case report and literature review.
Foetal membranes bulging into the abdominal cavity is a unique initial manifestation of silent or complete uterine rupture during pregnancy. Since silent uterine rupture has potential risk for complete uterine rupture, which leads to acute life-threatening complications for both the mother and baby, it is difficult to determine whether to manage expectantly or surgically, including repair of the uterine wall or termination of the pregnancy, especially in the early second trimester. We present here a case of a herniated amniotic sac with overstretched uterine wall of the fundus presenting as silent uterine rupture, which was incidentally detected on routine ultrasonography at 18 weeks' gestation in a 38-year-old primigravida with a history of myomectomy for diffuse uterine leiomyomatosis. Magnetic resonance imaging examination revealed that the myometrium thickness was fully maintained at the site of the foetal membranes ballooning. The pregnancy was therefore managed expectantly and continued to successful delivery at 30 weeks' gestation. The precise assessment of the uterine wall may be essential to manage a herniated amniotic sac presenting as silent uterine rupture and to optimise the outcome of the pregnancy. We review all cases of a herniated amniotic sac out of focally overstretched uterine wall before 34 weeks' gestation
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