242 research outputs found

    Wall thickness measurement using resonant phenomena of circumferential Lamb waves generated by plural transducer elements located evenly on girth

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    We present a novel method of measuring the pipe wall thickness using the resonance of the circumferential (C-) Lamb wave generated by a piezoelectric ring-shaped sensor (PS). The PS is a special device for an axially propagating torsional wave; however, the C-Lamb waves are generated simultaneously as spurious signals owing to the structure of the PS. Particularly under resonant conditions, the C-Lamb waves are dominantly generated, distorting the axially propagating wave. In this method, these troublesome spurious signals are used effectively for the measurement of the wall thickness under the PS location that is a dead zone of the PS itself. The method can compensate for its drawback, namely, the dead zone problem, without using additional instruments. In this study, the mechanisms of the generation and resonance of the C-Lamb waves were first explained. Secondly, the principle of the wall thickness estimation utilizing the resonance of the C-Lamb waves was proposed. Finally, experimental verifications were carried out. The estimated wall thicknesses agreed very well (maximum 1.5% error) with those measured by a micrometer caliper under suitable resonant conditions

    Investigation of the serum levels of anterior pituitary hormones in male children with autism

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    <p>Abstract</p> <p>Background</p> <p>The neurobiological basis of autism remains poorly understood. The diagnosis of autism is based solely on behavioural characteristics because there are currently no reliable biological markers. To test whether the anterior pituitary hormones and cortisol could be useful as biological markers for autism, we assessed the basal serum levels of these hormones in subjects with autism and normal controls.</p> <p>Findings</p> <p>Using a suspension array system, we determined the serum levels of six anterior pituitary hormones, including adrenocorticotropic hormone and growth hormone, in 32 drug-naive subjects (aged 6 to 18 years, all boys) with autism, and 34 healthy controls matched for age and gender. We also determined cortisol levels in these subjects by enzyme-linked immunosorbent assay. Serum levels of adrenocorticotropic hormone, growth hormone and cortisol were significantly higher in subjects with autism than in controls. In addition, there was a significantly positive correlation between cortisol and adrenocorticotropic hormone levels in autism.</p> <p>Conclusion</p> <p>Our results suggest that increased basal serum levels of adrenocorticotropic hormone accompanied by increased cortisol and growth hormone may be useful biological markers for autism.</p

    Does rapid maxillary expansion improve nasal airway obstruction? A computer fluid dynamics study in patients with nasal mucosa hypertrophy and obstructive adenoids

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    Introduction: Rapid maxillary expansion (RME) expands the maxillary dentition laterally and improves nasal airway obstruction. However, the incidence of nasal airway obstruction improvement following RME is approximately 60%. This study aimed to clarify the beneficial effects of RME on nasal airway obstruction in specific pathologic nasal airway diseases (nasal mucosa hypertrophy and obstructed adenoids) using computer fluid dynamics (CFD). Methods: Sixty subjects (21 boys, mean age 9.1 years) were divided into three groups according to their nasal airway condition (control, nasal mucosa hypertrophy, and obstructed adenoids), and those requiring RME had cone‐ beam computed tomography (CBCT) images taken before and after RME. CBCT data were used to evaluate the nasal airway ventilation condition (pressure) using CFD and measure the cross-sectional area (CSA) of the nasal airway. Results: The CSA of the nasal airway significantly increased after RME in all three groups. The pressures in the control and nasal mucosa groups significantly reduced after RME but did not change significantly in the adenoid group. The incidence of improvement in nasal airway obstruction in the control, nasal mucosa, and adenoid groups was 90%, 31.6%, and 23.1%, respectively. Conclusions: The incidence of improvement in nasal airway obstruction after RME depends on the nasal airway condition (nasal mucosa hypertrophy and obstructed adenoids). In patients with non-pathologic nasal airway conditions, the obstruction may be sufficiently improved with RME. Furthermore, RME may be effective, to some extent, in treating nasal mucosa hypertrophy. However, RME was not effective in patients with nasal airway obstruction due to obstructed adenoids

    Effect on tongue posture by tonsil hypertrophy

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    Objectives: This study aimed to clarify the effect of palatine tonsil hypertrophy-induced ventilation obstruction on maxillofacial dentition morphology using computational fluid dynamics (CFD) to represent tongue posture and maxillofacial dentition three dimensionally. Materials and Methods: We analyzed data of 20 patients with tonsil hypertrophy (tonsil hypertrophy group (TG); 9.0 years old, seven boys) and a comparison group (CG) of 20 patients without tonsil hyperplasia (comparison group; 9.4 years old, 10 boys). Cone-beam computed tomography and CFD data were used to assess the effects of palatine tonsil hypertrophy on pharyngeal airway ventilation, tongue posture, and morphology of the maxillofacial dentition. Results: The TG exhibited significantly greater depth, narrower width, smaller cross-sectional area of the pharyngeal airway, and narrower maxillary dental arch with Class II than the CG. Additionally, the tongue was positioned significantly more anteriorly and inferiorly in the TG than that in the CG. Conclusions: Our data suggest that hypertrophy of the palatine tonsils narrows the pharyngeal airway, resulting in a smaller cross-sectional area. Widening of the pharyngeal airway may occur due to compensatory anterior displacement of the tongue to prevent ventilation obstruction. This may decrease palatal support, disturbing the pressure balance of the maxillary molar region between the buccal and palatal sides and resulting in lateral undergrowth of the maxillary bone and narrowing of the maxillary dental arch

    Decreased expression of axon-guidance receptors in the anterior cingulate cortex in autism

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    <p>Abstract</p> <p>Background</p> <p>Axon-guidance proteins play a crucial role in brain development. As the dysfunction of axon-guidance signaling is thought to underlie the microstructural abnormalities of the brain in people with autism, we examined the postmortem brains of people with autism to identify any changes in the expression of axon-guidance proteins.</p> <p>Results</p> <p>The mRNA and protein expression of axon-guidance proteins, including ephrin (EFN)A4, eEFNB3, plexin (PLXN)A4, roundabout 2 (ROBO)2 and ROBO3, were examined in the anterior cingulate cortex and primary motor cortex of autistic brains (n = 8 and n = 7, respectively) and control brains (n = 13 and n = 8, respectively) using real-time reverse-transcriptase PCR (RT-PCR) and western blotting. Real-time RT-PCR revealed that the relative expression levels of EFNB3, PLXNA4A and ROBO2 were significantly lower in the autistic group than in the control group. The protein levels of these three genes were further analyzed by western blotting, which showed that the immunoreactive values for PLXNA4 and ROBO2, but not for EFNB3, were significantly reduced in the ACC of the autistic brains compared with control brains.</p> <p>Conclusions</p> <p>In this study, we found decreased expression of axon-guidance proteins such as PLXNA4 and ROBO2 in the brains of people with autism, and suggest that dysfunctional axon-guidance protein expression may play an important role in the pathophysiology of autism.</p

    Plasma Cytokine Profiles in Subjects with High-Functioning Autism Spectrum Disorders

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    Accumulating evidence suggests that dysregulation of the immune system is involved in the pathophysiology of autism spectrum disorders (ASD). The aim of the study was to explore immunological markers in peripheral plasma samples from non-medicated subjects with high-functioning ASD.A multiplex assay for cytokines and chemokines was applied to plasma samples from male subjects with high-functioning ASD (n = 28) and matched controls (n = 28). Among a total of 48 analytes examined, the plasma concentrations of IL-1β, IL-1RA, IL-5, IL-8, IL-12(p70), IL-13, IL-17 and GRO-α were significantly higher in subjects with ASD compared with the corresponding values of matched controls after correction for multiple comparisons.The results suggest that abnormal immune responses as assessed by multiplex analysis of cytokines may serve as one of the biological trait markers for ASD

    PIP3-Phldb2 is crucial for LTP regulating synaptic NMDA and AMPA receptor density and PSD95 turnover

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    The essential involvement of phosphoinositides in synaptic plasticity is well-established, but incomplete knowledge of the downstream molecular entities prevents us from understanding their signalling cascades completely. Here, we determined that Phldb2, of which pleckstrin-homology domain is highly sensitive to PIP3, functions as a phosphoinositide-signalling mediator for synaptic plasticity. BDNF application caused Phldb2 recruitment toward postsynaptic membrane in dendritic spines, whereas PI3K inhibition resulted in its reduced accumulation. Phldb2 bound to postsynaptic scaffolding molecule PSD-95 and was crucial for localization and turnover of PSD-95 in the spine. Phldb2 also bound to GluA1 and GluA2. Phldb2 was indispensable for the interaction between NMDA receptors and CaMKII, and the synaptic density of AMPA receptors. Therefore, PIP3-responsive Phldb2 is pivotal for induction and maintenance of LTP. Memory formation was impaired in our Phldb2−/− mice

    Macrophage Notch Ligand Delta-Like 4 Promotes Vein Graft Lesion Development, Implications for the Treatment of Vein Graft Failure

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    Objective—Despite its large clinical impact, the underlying mechanisms for vein graft failure remain obscure and no effective therapeutic solutions are available. We tested the hypothesis that Notch signaling promotes vein graft disease. Approach and Results—We used 2 biotherapeutics for Delta-like ligand 4 (Dll4), a Notch ligand: (1) blocking antibody and (2) macrophage- or endothelial cell (EC)–targeted small-interfering RNA. Dll4 antibody administration for 28 days inhibited vein graft lesion development in low-density lipoprotein (LDL) receptor-deficient (Ldlr−/−) mice, and suppressed macrophage accumulation and macrophage expression of proinflammatory M1 genes. Dll4 antibody treatment for 7 days after grafting also reduced macrophage burden at day 28. Dll4 silencing via macrophage-targeted lipid nanoparticles reduced lesion development and macrophage accumulation, whereas EC-targeted Dll4 small-interfering RNA produced no effects. Gain-of-function and loss-of-function studies suggested in vitro that Dll4 induces proinflammatory molecules in macrophages. Macrophage Dll4 also stimulated smooth muscle cell proliferation and migration and suppressed their differentiation. Conclusions—These results suggest that macrophage Dll4 promotes lesion development in vein grafts via macrophage activation and crosstalk between macrophages and smooth muscle cells, supporting the Dll4–Notch axis as a novel therapeutic target.United States. National Institutes of Health (R01HL107550)American Heart Association (0655878T)American Heart Association (12GRNT9510001)American Heart Association (12GRNT1207025)Good Samaritan FoundationShapiro Family Foundatio

    Magnetized Fast Isochoric Laser Heating for Efficient Creation of Ultra-High-Energy-Density States

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    The quest for the inertial confinement fusion (ICF) ignition is a grand challenge, as exemplified by extraordinary large laser facilities. Fast isochoric heating of a pre-compressed plasma core with a high-intensity short-pulse laser is an attractive and alternative approach to create ultra-high-energy-density states like those found in ICF ignition sparks. This avoids the ignition quench caused by the hot spark mixing with the surrounding cold fuel, which is the crucial problem of the currently pursued ignition scheme. High-intensity lasers efficiently produce relativistic electron beams (REB). A part of the REB kinetic energy is deposited in the core, and then the heated region becomes the hot spark to trigger the ignition. However, only a small portion of the REB collides with the core because of its large divergence. Here we have demonstrated enhanced laser-to-core energy coupling with the magnetized fast isochoric heating. The method employs a kilo-tesla-level magnetic field that is applied to the transport region from the REB generation point to the core which results in guiding the REB along the magnetic field lines to the core. 7.7 ±\pm 1.3 % of the maximum coupling was achieved even with a relatively small radial area density core (ρR\rho R \sim 0.1 g/cm2^2). The guided REB transport was clearly visualized in a pre-compressed core by using Cu-KαK_\alpha imaging technique. A simplified model coupled with the comprehensive diagnostics yields 6.2\% of the coupling that agrees fairly with the measured coupling. This model also reveals that an ignition-scale areal density core (ρR\rho R \sim 0.4 g/cm2^2) leads to much higher laser-to-core coupling (>> 15%), this is much higher than that achieved by the current scheme
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