317 research outputs found
An Analysis of Thickness-shear Vibrations of an Annular Plate with the Mindlin Plate Equations
The Mindlin plate equations with the consideration of thickness-shear
deformation as an independent variable have been used for the analysis of
vibrations of quartz crystal resonators of both rectangular and circular types.
The Mindlin or Lee plate theories that treat thickness-shear deformation as an
independent higher-order vibration mode in a coupled system of two-dimensional
variables are the choice of theory for analysis. For circular plates, we
derived the Mindlin plate equations in a systematic manner as demonstrated by
Mindlin and others and obtained the truncated two-dimensional equations of
closely coupled modes in polar coordinates. We simplified the equations for
vibration modes in the vicinity of fundamental thickness-shear frequency and
validated the equations and method. To explore newer structures of quartz
crystal resonators, we utilized the Mindlin plate equations for the analysis of
annular plates with fixed inner and free outer edges for frequency spectra. The
detailed analysis of vibrations of circular plates for the normalized frequency
versus dimensional parameters provide references for optimal selection of
parameters based on the principle of strong thickness-shear mode and minimal
presence of other modes to enhance energy trapping through maintaining the
strong and pure thickness-shear vibrations insensitive to some complication
factors such as thermal and initial stresses.Comment: Paper to be presented to the 2015 IEEE International Frequency
Control Symposium and European Frequency and Time Forum, Denver, CO, USA.
April 12-16, 201
A Case of Lewis-Sumner Syndrome Showing Dramatic Improvement after Plasma Exchange
We report a patient with Lewis-Sumner syndrome (LSS) who showed an improvement only with plasma exchange (PE). The patient, 32-yr old man, had progressive multifocal motor-sensory deficits with persistent, multiple conduction blocks and marked slowing of NCVs. Nerve pathology supported a diagnosis of demyelinating neuropathy by revealing marked loss of myelinated fibers with inter- and intrafascicular variation. Although the patient was refractory to treatment with corticosteroid and intravenous immunoglobulin, PE produced a dramatic improvement. Our experience strongly proposes that PE should be tried for refractory LSS
Baseline Sensitivity of Echinochloa crus-gall and E. oryzicola to Florpyrauxifen-Benzyl, a New Synthetic Auxin Herbicide, in Korea
Echinochloa species is one of the most problematic weed species due to its high competitiveness and increasing herbicide resistance. Florpyrauxifen-benzyl, a new auxin herbicide, was recently introduced for Echinochloa management; however, the potential risk for the development of herbicide resistance in Echinochloa species has not been well-investigated. Thus, this study was conducted to evaluate the baseline sensitivity of Echinochloa species to florpyrauxifen-benzyl to estimate the risk of future resistance development. A total of 70 and 71 accessions of Echinochloa crus-galli and Echinochloa oryzicola were collected from paddy fields in Korea, respectively. These two Echinochloa species were grown in plastic pots up to the 5-leaf stage, and treated with florpyrauxifen-benzyl at a range of doses from 2.2 g to 70.0 g a.i. ha–1. Nonlinear regression analyses revealed that GR50 values for E. oryzicola ranged from 4.54 g to 29.66 g a.i. ha–1, giving a baseline sensitivity index (BSI) of 6.53, while those for E. crus-galli ranged from 6.15 g to 16.06 g a.i. ha–1, giving a BSI of 2.61. Our findings suggest that E. oryzicola has a greater potential risk than E. crus-galli for the development of metabolism-based resistance to florpyrauxifen-benzyl
EPPE project: Relationships between pupils’ self-perceptions, views of primary school and their development at age 10 [IOE Research Briefing N°68]
This research focuses on pupils' self-perceptions and their views of different features of primary school in Year 5 (age 10). IOE Research Briefings are short descriptions of significant research findings, based on the wide range of projects carried out by IOE researchers
Comparison of Endoscopic Tympanoplasty to Microscopic Tympanoplasty
Objectives This study aimed to compare the outcome of endoscopic and microscopic tympanoplasty. Methods This was a retrospective comparative study of 73 patients (35 males and 38 females) who underwent type I tympanoplasty at Samsung Medical Center from April to December 2014. The subjects were classified into two groups; endoscopic tympanoplasty (ET, n=25), microscopic tympanoplasty (MT, n=48). Demographic data, perforation size of tympanic membrane at preoperative state, pure tone audiometric results preoperatively and 3 months postoperatively, operation time, sequential postoperative pain scale (NRS-11), and graft success rate were evaluated. Results The perforation size of the tympanic membrane in ET and MT group was 25.3%±11.7% and 20.1%±11.9%, respectively (P=0.074). Mean operation time of MT (88.9±28.5 minutes) was longer than that of the ET (68.2±22.1 minutes) with a statistical significance (P=0.002). External auditory canal (EAC) width was shorter in the ET group than in the MT group (P=0.011). However, EAC widening was not necessary in the ET group and was performed in 33.3% of patients in the MT group. Graft success rate in the ET and MT group were 100% and 95.8%, respectively; the values were not significantly different (P=0.304). Pre- and postoperative audiometric results including bone and air conduction thresholds and air-bone gap were not significantly different between the groups. In all groups, the postoperative air-bone gap was significantly improved compared to the preoperative air-bone gap. Immediate postoperative pain was similar between the groups. However, pain of 1 day after surgery was significantly less in the ET group. Conclusion With endoscopic system, minimal invasive tympanoplasty can be possible with similar graft success rate and less pain
Post-Transcriptional Regulation of Cadherin-11 Expression by GSK-3 and β-Catenin in Prostate and Breast Cancer Cells
The cell-cell adhesion molecule cadherin-11 is important in embryogenesis and bone morphogenesis, invasion of cancer cells, lymphangiogenesis, homing of cancer cells to bone, and rheumatoid arthritis. However, very little is known about the regulation of cadherin-11 expression.Here we show that cell density and GSK-3beta regulate cadherin-11 levels in cancer cells. Inactivation of GSK3beta with lithium chloride or the GSK3 inhibitor BIO and GSK3beta knockdown with siRNA repressed cadherin-11 mRNA and protein levels. RNA Polymerase II chromatin immunoprecipitation experiments showed that inhibition of GSK3 does not affect cadherin-11 gene transcription. Although the cadherin-11 3'UTR contains putative microRNA target sites and is regulated by Dicer, its stability is not regulated by GSK3 inhibition or density. Our data show that GSK3beta regulates cadherin-11 expression in two ways: first a beta-catenin-independent regulation of cadherin-11 steady state mRNA levels, and second a beta-catenin-dependent effect on cadherin-11 3'UTR stability and protein translation.Cadherin-11 mRNA and protein levels are regulated by the activity of GSK3beta and a significant degree of this regulation is exerted by the GSK3 target, beta-catenin, at the level of the cadherin-11 3'UTR
Effect of 5/6 Nephrectomized Rat Serum on Epithelial-to-Mesenchymal Transition In Vitro
Objective: To investigate whether the 5/6 nephrectomized (5/6Nx) rats’ 12-week serum could lead to tubular epithelial-to-mesenchymal transition (EMT) and its molecular mechanism, so as to probe the potential stimulation from circulation in chronic progressive kidney disease. Methods: A total of 24 Sprague Dawley (SD) rats were randomly divided into two groups: sham operation group (sham group) and 5/6Nx group. Rats were killed 12 weeks after surgery to obtain 5/6Nx rats’ 12-week serum. Then we detected the expression of E-cadherin in renal tubular epithelial cells of the remaining kidney and we investigated whether the 12th week serum of 5/6Nx rats could cause HK-2 (human kidney proximal tubular cell line) cells to transdifferentiate into fibroblasts. Results: Our data confirmed that E-cadherin expression decreased significantly in the remaining kidney at 12 weeks, and the 5/6Nx rats’ 12-week serum could suppress E-cadherin protein and mRNA expression (p < 0.05). We also found that the 5/6Nx rats’ 12-week serum could upreg-ulate ZEB1, β-catenin, and wnt3 protein expression (p < 0.05). Conclusions: Our results demonstrated that the 5/6Nx rats’ 12-week serum could suppress the expression of E-cadherin in HK-2 cells. It was partially through modulating the increase of ZEB1. The loss of E-cadherin could lead β-catenin to localize to the cytoplasm and nucleus, and feed into the Wnt signaling pathway. It means that the pathogenic serum in chronic kidney disease (CKD) plays an important role in the loss of renal function and turns to be a new avenue of research with potential clinical implications
Functional redundancy between Apc and Apc2 regulates tissue homeostasis and prevents tumorigenesis in murine mammary epithelium
Aberrant Wnt signaling within breast cancer is associated with poor prognosis, but regulation of this pathway in breast tissue remains poorly understood and the consequences of immediate or long-term dysregulation remain elusive. The exact contribution of the Wnt-regulating proteins adenomatous polyposis coli (APC) and APC2 in the pathogenesis of human breast cancer are ill-defined, but our analysis of publically available array data sets indicates that tumors with concomitant low expression of both proteins occurs more frequently in the ‘triple negative’ phenotype, which is a subtype of breast cancer with particularly poor prognosis. We have used mouse transgenics to delete Apc and/or Apc2 from mouse mammary epithelium to elucidate the significance of these proteins in mammary homeostasis and delineate their influences on Wnt signaling and tumorigenesis. Loss of either protein alone failed to affect Wnt signaling levels or tissue homeostasis. Strikingly, concomitant loss led to local disruption of β-catenin status, disruption in epithelial integrity, cohesion and polarity, increased cell division and a distinctive form of ductal hyperplasia with ‘squamoid’ ghost cell nodules in young animals. Upon aging, the development of Wnt activated mammary carcinomas with squamous differentiation was accompanied by a significantly reduced survival. This novel Wnt-driven mammary tumor model highlights the importance of functional redundancies existing between the Apc proteins both in normal homeostasis and in tumorigenesis
Expression analysis of E-cadherin, Slug and GSK3β in invasive ductal carcinoma of breast
<p>Abstract</p> <p>Background</p> <p>Cancer progression is linked to a partially dedifferentiated epithelial cell phenotype. The signaling pathways Wnt, Hedgehog, TGF-β and Notch have been implicated in experimental and developmental epithelial mesenchymal transition (EMT). Recent findings from our laboratory confirm that active Wnt/β-catenin signaling is critically involved in invasive ductal carcinomas (IDCs) of breast.</p> <p>Methods</p> <p>In the current study, we analyzed the expression patterns and relationships between the key Wnt/β-catenin signaling components- E-cadherin, Slug and GSK3β in IDCs of breast.</p> <p>Results</p> <p>Of the 98 IDCs analyzed, 53 (54%) showed loss/or reduced membranous staining of E-cadherin in tumor cells. Nuclear accumulation of Slug was observed in 33 (34%) IDCs examined. Loss or reduced level of cytoplasmic GSK3β expression was observed in 52/98 (53%) cases; while 34/98 (35%) tumors showed nuclear accumulation of GSK3β. Statistical analysis revealed associations of nuclear Slug expression with loss of membranous E-cadherin (p = 0.001); nuclear β-catenin (p = 0.001), and cytoplasmic β-catenin (p = 0.005), suggesting Slug mediated E-cadherin suppression via the activation of Wnt/β-catenin signaling pathway in IDCs. Our study also demonstrated significant correlation between GSK3β nuclear localization and tumor grade (p = 0.02), suggesting its association with tumor progression.</p> <p>Conclusion</p> <p>The present study for the first time provided the clinical evidence in support of Wnt/β-catenin signaling upregulation in IDCs and key components of this pathway - E-cadherin, Slug and GSK3β with β-catenin in implementing EMT in these cells.</p
- …