Pull-In Analysis of the Flat Circular CMUT Cell Featuring Sealed Cavity

Capacitive micromachined ultrasonic transducers (CMUTs) are one of the appealing MEMS devices. Most studies treat CMUTs as rigid plates vibrating in open air, ignoring the mechanical boundary conditions for simplification and resulting in cumulative errors in coupled fields. This paper presents a new analytical model for the pull-in characteristics of the flat circular CMUT cell featuring sealed cavity. Utilizing the plate theory coupled with Boyle’s law, the paper establishes a strong relation between the pressures inside the sealed cavity and the pull-in characteristics for the first time. Not only did we point out that the existence of the pressure inside the sealed cavity cannot be omitted, but we also quantified the direct effect of the pressure ratios on the pull-in phenomenon. The pull-in voltages increase while the pull-in ratios decrease with the pressure ratios of the pressure inside the sealed cavity to the ambient pressure. The proposed calculation process delivers a good approximation of the pull-in voltages and displacements, which are consistent with COMSOL simulation results. Particularly, the percentage error of our calculation process is 6.986% for the worst case. Therefore, our proposed analytical model accurately and efficiently predicts the pull-in characteristics and this paper offers new perspectives and reference value in designing and modeling the CMUTs

Folliculin Interacts with Rab35 to Regulate EGF-Induced EGFR Degradation

Aims and Hypothesis: This study aims to investigate the mechanism involved in intracellular regulation of EGFR degradation induced by EGF.Methods: Phosphorylation of proteins related to EGFR signaling was examined by western blot analysis. Activation, connection between Rab35 and folliculin (FLCN) were assessed by pulldown, coimmunoprecipitation assays separately. The relationship between FLCN and cell growth was detected using gene overexpression and knock-down techniques.Results: Here, we demonstrate that interfering with FLCN, a tumor suppressor, reduces the rate of EGF-induced EGFR degradation, resulting in prolonged activation of downstream signaling. Rab35 is also involved in these processes. Moreover, C-terminal of FLCN binds to and activates Rab35. Of special interest is the observation that erlotinib, a selective EGFR inhibitor, not only obstructs the EGFR-mediated cellular signaling, but also abolishes EGF-stimulated EGFR degradation. Further results reveal that EGF facilitates the activation of Rab35, and FLCN modulates EGF-dependent Rab35 activation and cell growth.Conclusions: Taken together, our study proposes a negative-feedback regulation model in which FLCN mediates EGF-induced Rab35 activation, thereby increasing EGFR degradation and attenuating EGFR signaling

Determination of Metal Elements in Workplace Air by ICP-MS

It was important to assess workplace air quality in factory where the air quality has a significant impact on the health of workers. This study aimed to determine the concentrations of metal elements in workplace air of factory. In this article, an easy and quick method based on microwave assisted acid digestion technique prior to quantification using inductively coupled plasma mass spectrometry (ICP-MS) for measuring contents of 7 metal (Cr, Mn, Ni, Cu, Pb, Cd and Sn) elements in workplace air. The air samples were collected by quartz filter membrane. The samples were respectively prepared by microwave digestion system and nitric acid. Under the optimum condition of method, the calibration curves were obtained with correlation correlation coefficients were above 0.9994, the limits of detection of the method were 0.004-0.072 mg/L. The average recoveries of the 7 metal elements at three levels were in the range of 93.8%-102.3%. The proposed method has some advantages of simple operation, high sensitivity and good accutacy

Determination of Metal Elements in Workplace Air by ICP-MS

It was important to assess workplace air quality in factory where the air quality has a significant impact on the health of workers. This study aimed to determine the concentrations of metal elements in workplace air of factory. In this article, an easy and quick method based on microwave assisted acid digestion technique prior to quantification using inductively coupled plasma mass spectrometry (ICP-MS) for measuring contents of 7 metal (Cr, Mn, Ni, Cu, Pb, Cd and Sn) elements in workplace air. The air samples were collected by quartz filter membrane. The samples were respectively prepared by microwave digestion system and nitric acid. Under the optimum condition of method, the calibration curves were obtained with correlation correlation coefficients were above 0.9994, the limits of detection of the method were 0.004-0.072 mg/L. The average recoveries of the 7 metal elements at three levels were in the range of 93.8%-102.3%. The proposed method has some advantages of simple operation, high sensitivity and good accutacy

Louqin Zhisou Decoction Inhibits Mucus Hypersecretion for Acute Exacerbation of Chronic Obstructive Pulmonary Disease Rats by Suppressing EGFR-PI3K-AKT Signaling Pathway and Restoring Th17/Treg Balance

Airway mucus hypersecretion is the main pathogenic factor in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and the control of mucus secretion is closely associated with survival. Louqin Zhisou decoction (LQZS) has been found to improve lung function and reduce sputum in AECOPD patients, but the mechanism remains unclear. This study aimed to explore the mechanism of LQZS against mucus hypersecretion in lung tissues of rat AECOPD model. Wistar rats were used to establish AECOPD model by intratracheal instillation of LPS in combination with the continuous cigarette smoking. Rats were administrated LQZS/clarithromycin (CAM)/distilled water via gavage every day and all rats were sacrificed after 30 days. BALF and lung tissues were obtained. Lung morphology, cytokines levels, MUC5AC mRNA transcription and protein expression, phosphorylation of the EGFR-PI3K-AKT signaling pathway, and molecules involved in Th17/Treg balance were evaluated. The results demonstrated that LQZS protected rats from decline in pulmonary function and ameliorated lung injury. LQZS treatment decreased the number of goblet cells in airway and suppressed MUC5AC mRNA and protein expression of lung tissues. Furthermore, LQZS attenuated the level of phospho-EGFR, phospho-PI3K and phospho-AKT in AECOPD rats. In addition, LQZS could inhibit the production of proinflammatory cytokines in BALF, including IL-6 and IL-17A and downregulate the secretion of NE and MCP-1, indicating that LQZS could limit inflammatory responses in AECOPD. Moreover, LQZS reversed RORγt and Foxp3 expression, the key transcription factors of Th17 and Treg, respectively. In conclusion, this research demonstrated the inhibitory effects of LQZS against mucus hypersecretion in AECOPD via suppressing EGFR-PI3K-AKT signaling pathway and restoring Th17/Treg balance

An improved U-Net model for concrete crack detection

Crack detection plays an important role in disease assessment of concrete buildings. However, factors such as complex background, irregular edge, and the real-time and accuracy requirement also make crack detection a challenging task. Aiming at the above challenges, an improved U-Net model for concrete crack detection is proposed, which has strong capability to extract the linear object, improving the performance in crack detection. The model is named Residual Linear Attention U-Net (RLAU-Net). There are three key measures in this paper. First, mirror padding the source image before convolution. Second, the multi-level features are obtained by aggregating the multi-scale features level by level. Third, strip pooling kernels are used to extract global contextual information, reducing information interference from the background. We tested the performance of RLAU-Net on our crack dataset, and the experimental results exhibited that it can improve the quantitative results of mean Intersection Over Union to 81.69%. In addition, F1 score has increased to, 78.21%, the Intersection Over Union of crack increased to 64.47%. We also compared the detect time-consuming of RLAU-Net and that of the original U-Net. Results demonstrate that the proposed model has a short processing time while maintaining a high detection accuracy for crack detection

Thinking in 3D : The Effect of 3D Boxes on Waste Sorting Accuracy

Waste sorting accuracy has long been a problem for sustainable waste management. One proposed solution is the placement of 3D signage as a guide for people to sort waste. Previous literature found that 3D signage had zero to a minimal increase in sorting accuracy. This study examines the impact of additional 3D boxes on sorting accuracy at the UBC AMS Nest. The study was conducted over the course of two weeks, with one week for each of the conditions. A waste sorting station by Pie R Squared was observed during lunch hours from 12-2pm over the course of two weeks with one week allocated for each condition. In the control condition, the sorting station only had 2D signage while 3D signage was added along with the 2D signage in the experimental condition. Data was collected in the form of photographs of the top of each waste bin. The results from statistical data analysis showed the difference between the two conditions to be insignificant. We concluded that 3D boxes are cost-inefficient based on the results of this study and previous studies, and suggest utilizing a manned, food court style waste sorting station as an alternative solution to sorting accuracy. Disclaimer: “UBC SEEDS provides students with the opportunity to share the findings of their studies, as well as their opinions, conclusions and recommendations with the UBC community. The reader should bear in mind that this is a student project/report and is not an official document of UBC. Furthermore readers should bear in mind that these reports may not reflect the current status of activities at UBC. We urge you to contact the research persons mentioned in a report or the SEEDS Coordinator about the current status of the subject matter of a project/report.”Arts, Faculty ofScience, Faculty ofPsychology, Department ofResources, Environment and Sustainability (IRES), Institute forUnreviewedUndergraduat