852 research outputs found

    Analysis of nonlinear dynamic behavior and pull-in prediction of micro circular plate actuator

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    The dynamic behavior of micro circular plate electrostatic devices is not easily analyzed using traditional methods such as perturbation theory or Galerkin approach method due to the complexity of the interactions among the electrostatic coupling effect, the residual stress and the nonlinear electrostatic force. Accordingly, the present study proposes a approach for analyzing the dynamic response of such devices using a hybrid numerical scheme comprising the differential transformation method and the finite difference method. The feasibility of the proposed approach is demonstrated by modeling the dynamic response of a micro circular plate actuated by a DC voltage. The numerical results for the pull-in voltage are found to deviate by no more than 0.27 % from those derived in the literature using various computational methods. Thus, the basic validity of the hybrid numerical scheme is confirmed. Moreover, the effectiveness of a combined DC/AC loading scheme in driving the micro circular actuator is examined. It is shown that the use of an AC actuating voltage in addition to the DC driving voltage provides an effective means of tuning the dynamic response of the micro circular plate

    Evaluation on the Pharmacological Effect of Traditional Chinese Medicine SiJunZiTang on Stress-Induced Peptic Ulcers

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    Purpose. To explore the effects of SiJunZiTang (SJZT) on central neurotransmitters and the inhibition of HCl hypersecretion, along with the role of the vagus nerve. From this, the effects of SJZT and its constituent ingredients on inhibiting stress-induced peptic ulcers will be determined. Methods. Methods used to determine SJZT's effectiveness included (1) measuring the antipeptic ulcer effects of varying combinations of the constituents of SJZT; (2) evaluations of monoamine (MA) level in the brain; and (3) measuring the effects of longer-term SJZT treatment. Results. Comparing the control and experimental groups where the rats’ vagus nerves were not cut after taking SJZT orally (500 mg/kg and 1000 mg/kg), the volume of enterogastric juice, free HCl and total acidity all reduce dose-dependently. The group administered SJZT at 1000 mg/kg showed significant reductions (P<0.05). For the experimental groups where the vagus nerves were cut, a comparison with the control group suggests that the group receiving SJZT (500 mg/kg) orally for 21 days demonstrated a cure rate of 34.53%. Conclusion. The results display a correlation between the therapeutic effects of SJZT on stress-induced peptic ulcers and central neurotransmitter levels. Further to this, SJZT can inhibit the hypersecretion of HCl in the stomach, thus inhibiting stress-induced peptic ulcers

    Prediction model for high glycated hemoglobin concentration among ethnic Chinese in Taiwan

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    <p>Abstract</p> <p>Background</p> <p>This study aimed to construct a prediction model to identify subjects with high glycated hemoglobin (HbA1c) levels by incorporating anthropometric, lifestyle, clinical, and biochemical information in a large cross-sectional ethnic Chinese population in Taiwan from a health checkup center.</p> <p>Methods</p> <p>The prediction model was derived from multivariate logistic regression, and we evaluated the performance of the model in identifying the cases with high HbA1c levels (> = 7.0%). In total 17,773 participants (age > = 30 years) were recruited and 323 participants (1.8%) had high HbA1c levels. The study population was divided randomly into two parts, with 80% as the derivation data and 20% as the validation data.</p> <p>Results</p> <p>The point-based clinical model, including age (maximal 8 points), sex (1 point), family history (3 points), body mass index (2 points), waist circumference (4 points), and systolic blood pressure (3 points) reached an area under the receiver operating characteristic curve (AUC) of 0.723 (95% confidence interval, 0.677- 0.769) in the validation data. Adding biochemical measures such as triglycerides and HDL cholesterol improved the prediction power (AUC, 0.770 [0.723 - 0.817], <it>P </it>= < 0.001 compared with the clinical model). A cutoff point of 7 had a sensitivity of 0.76 to 0.96 and a specificity of 0.39 to 0.63 for the prediction model.</p> <p>Conclusions</p> <p>A prediction model was constructed for the prevalent risk of high HbA1c, which could be useful in identifying high risk subjects for diabetes among ethnic Chinese in Taiwan.</p

    The Clinical COPD Questionnaire Correlated with BODE Index-A Cross-Sectional Study

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    The Global initiative for Chronic Obstructive Lung Disease (GOLD) staging has widely used in the stratification of the severity of COPD, while BODE (body mass index, airflow obstruction, dyspnea, and exercise capacity) index was proven superior to FEV1 in predicting mortality, exacerbation and disease severity in patients with COPD. Clinical COPD Questionnaire (CCQ), a questionnaire with ten items categorized into three domains (symptoms, functional state and mental state) was developed to measure health status of COPD patients. However, little is known about the relationship between CCQ score and BODE index. We performed a prospective study with the inclusion of 89 patients who were clinically stable after a 6-week-therapy for COPD symptoms comparing their health status assessed by CCQ, BODE index and GOLD staging. We found that the total CCQ score was correlated with BODE score (P < 0.001) and GOLD staging (P < 0.001); of three CCQ domains, the functional status correlated the most with BODE index (rS = 0.670) and GOLD staging (rS = 0.531), followed by symptoms (rS = 0.482; rS = 0.346, respectively), and mental status (rS = 0.340; rS = 0.236, respectively). Our data suggest that CCQ is a reliable and convenient alternative tool to evaluate the severity of COPD

    “Same same” but different? Exploring the impact of perceived organizational support at the school and teacher levels on teachers’ job engagement and organizational citizenship behavior

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    All countries in the world are currently trying to implement educational reform, which increases the additional workload of teachers. It is more important to discuss how to inspire teachers’ enthusiasm for educational reform from the perspective of organizational support (OS). Previous research on OS was limited to perceived organizational support (POS), but in recent years group-level OS has been considered the most promising. There is no study comparing POS and group-level OS in education, and therefore this study explored the relationships between OS, job engagement (JE) and organizational citizenship behavior (OCB) in an educational context. In particular, OS was examined at the individual-level (POS) and the aggregated group-level (school organizational support, SOS). Analysis was performed using structural equation modeling (SEM) at both single and multiple levels. SEM results showed direct and positive relationships of individual-level POS with both JE and OCB. Moreover, JE is directly and positively related to OCB and plays the partial mediating role of the indirect and positive impact of POS on OCB. Multilevel structural equation modeling (MSEM) analysis revealed direct and positive relationships of SOS with teachers’ JE, which was directly and positively related to their OCB. While SOS had no significant positive relationship with OCB, it did have a positive impact on OCB through the mediation of JE. Comparison between SEM and MSEM results revealed the change in effect of OS on OCB from significant to insignificant, thus implying full mediation effect of JE when SOS is considered

    The Arabidopsis Malectin-Like/LRR-RLK IOS1 is Critical for BAK1-Dependent and BAK1-Independent Pattern-Triggered Immunity

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    Plasma membrane-localized pattern recognition receptors (PRRs) such as FLAGELLIN SENSING2 (FLS2), EF-TU RECEPTOR (EFR) and CHITIN ELICITOR RECEPTOR KINASE 1 (CERK1) recognize microbe-associated molecular patterns (MAMPs) to activate pattern-triggered immunity (PTI). A reverse genetics approach on genes responsive to the priming agent beta-aminobutyric acid (BABA) revealed IMPAIRED OOMYCETE SUSCEPTIBILITY1 (IOS1) as a critical PTI player. Arabidopsis thaliana ios1 mutants were hyper-susceptible to Pseudomonas syringae bacteria. Accordingly, ios1 mutants showed defective PTI responses, notably delayed up-regulation of the PTI-marker gene FLG22-INDUCED RECEPTOR-LIKE KINASE1 (FRK1), reduced callose deposition and mitogen-activated protein kinase activation upon MAMP treatment. Moreover, Arabidopsis lines over-expressing IOS1 were more resistant to bacteria and showed a primed PTI response. In vitro pull-down, bimolecular fluorescence complementation, co-immunoprecipitation, and mass spectrometry analyses supported the existence of complexes between the membrane-localized IOS1 and BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1 (BAK1)-dependent PRRs FLS2 and EFR, as well as with the BAK1-independent PRR CERK1. IOS1 also associated with BAK1 in a ligand-independent manner, and positively regulated FLS2-BAK1 complex formation upon MAMP treatment. In addition, IOS1 was critical for chitin-mediated PTI. Finally, ios1 mutants were defective in BABA-induced resistance and priming. This work reveals IOS1 as a novel regulatory protein of FLS2-, EFR- and CERK1-mediated signaling pathways that primes PTI activation

    Knockdown of PsbO leads to induction of HydA and production of photobiological H2 in the green alga Chlorella sp. DT

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    Green algae are able to convert solar energy to H2 via the photosynthetic electron transport pathway under certain conditions. Algal hydrogenase (HydA, encoded by HYDA) is in charge of catalyzing the reaction: 2H+ + 2e− ↔ H2 but usually inhibited by O2, a byproduct of photosynthesis. The aim of this study was to knockdown PsbO (encoded by psbO), a subunit concerned with O2 evolution, so that it would lead to HydA induction. The alga, Chlorella sp. DT, was then transformed with short interference RNA antisense-psbO (siRNA-psbO) fragments. The algal mutants were selected by checking for the existence of siRNA-psbO fragments in their genomes and the low amount of PsbO proteins. The HYDA transcription and the HydA expression were observed in the PsbO-knockdown mutants. Under semi-aerobic condition, PsbO-knockdown mutants could photobiologically produce H2 which increased by as much as 10-fold in comparison to the wild type

    A reduced risk of stroke with lithium exposure in bipolar disorder: a population‐based retrospective cohort study

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/115969/1/bdi12336.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/115969/2/bdi12336_am.pd

    The Potential Utility of Curcumin in the Treatment of HER-2-Overexpressed Breast Cancer: An In Vitro and In Vivo Comparison Study with Herceptin

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    HER-2 is an important oncoprotein overexpressed in about 15–25% of breast cancers. We hypothesized that the ability of curcumin to downregulate HER-2 oncoprotein and inhibit the signal transduction pathway of PI3K/Akt, MAPK, and NF-κB activation may be important in the treatment of HER-2-overexpressed breast cancer. To examine the effect of curcumin on breast cancer cells, MCF-7, MDA-MB-231, MCF-10A, BT-474, and SK-BR-3-hr (a herceptin resistant strain from SK-BR-3) cells were used for in vitro analysis. The in vivo effect of curcumin on HER-2-overexpressed breast cancer was investigated with the HER-2-overexpressed BT-474 xenograft model. Cell growth, cell cycle change, the antimobility effect, signal transduction, and xenograft volume analysis between groups treated with herceptin and/or curcumin were tested. Curcumin decreased the cell growth of various breast cancer cell lines (MCF-7, MDA-MB-231, MCF-10A, BT-474, and SK-BR-3-hr). In Western blot analysis, the phosphorylation of Akt, MAPK, and expression of NF-κB were reduced in BT-474 cells, but not in SK-BR-3-hr cells, after treatment with herceptin. When treated with curcumin, the HER-2 oncoprotein, phosphorylation of Akt, MAPK and expression of NF-κB were decreased in both BT-474 and SK-BR-3-hr cells. In the BT-474 xenograft model, though not as much as herceptin, curcumin did effectively decrease the tumor size. The combination of curcumin with herceptin was not better than herceptin alone; however, the combination of taxol and curcumin had an antitumor effect comparable with taxol and herceptin. The results suggested that curcumin has potential as a treatment for HER-2-overexpressed breast cancer

    Effect of Supplementation of Tanshinone IIA and Sodium Tanshinone IIA Sulfonate on the Anticancer Effect of Epirubicin: An In Vitro Study

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    Tanshinone IIA (Tan IIA) and sodium tanshinone IIA sulfonate (STS) were found to have protective effects on cardiomyocyte against adriamycin-induced damage and may be used clinically. It is unclear whether the supplementation of STS or Tan IIA would affect the anticancer activity of anthracycline. To evaluate the effect of Tan IIA or STS on the anticancer of epirubicin, the cell viability, apoptosis, Akt expression, and uptake of epirubicin after supplementation of Tan IIA or STS in the epirubicin-treated BT-20 cells were measured and compared. Tan IIA inhibited BT-20 cell growth and induced apoptosis in a time- and dose-dependent manner. When Tan IIA was used with epirubicin, an increase of BT-20 cells apoptosis was accompanied by the decreasing phosphorylation of Akt. STS had no effect on the cell viability of BT-20 cells. However, when used with epirubicin, STS decreased the epirubicin-induced cytotoxicity and apoptosis in BT-20 cells. The antagonistic effect of STS on epirubicin-induced cytotoxicity in BT-20 cells occurred concomitantly with the reduced epirubicin uptake and the increased phosphorylation of Akt. STS decreased the uptake of epirubicin in BT-20 cells and blocked epirubicin-induced apoptosis through activation of Akt
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