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The highest-level fluctuations in large pump-turbines are usually originated from rotor-stator interaction (RSI) in the vaneless region. Hence, the studies of RSI phenomenon and corresponding unsteady effects are significantly important to reduce the pressure fluctuations. In this paper, firstly, RSI in a pump-turbine, featuring 20 stay vanes, 20 guide vanes and 9 runner blades, is analyzed through diameter mode theory, which has been used widely. Then, 3-D unsteady numerical simulations are performed under six guide vane openings in turbine mode. The comparison including performance and pressure characteristics between numerical and experimental results shows a good agreement. Finally, best guide vane opening 21° is chosen to analyze the distribution of pressure fluctuations. The detailed investigation of numerical results shows that frequencies in the vaneless region at best guide vane opening are mainly blade passing frequency (BPF) and its harmonic frequencies caused from RSI. The variation of BPF and its harmonic frequencies is confirmed by diameter mode theory. For this type of the pump-turbine, the amplitude of 2BPF (18fn) shows the highest corresponding diameter mode k2=-2, which indicates two high pressure regions caused by the component of 18fn in the vaneless region. Furthermore, the two high-pressure regions rotate in the counterclockwise direction with rotational speed of the runner blades. This research could provide a basic understanding of RSI to have a further study for pressure fluctuations in pump-turbines. [ABSTRACT FROM AUTHOR]

Fibreglass nonwoven composites are a new class of fibre-reinforced composites, and in this work composite samples were manufactured by using nonwoven webs as reinforcement and thermo-setting resin as matrix. The samples were prepared by using a resin infusion technique, and the nonwoven webs were manufactured by a wet-laying method. In this research work, the main purpose was to investigate the effects of different process variables, i.e. dispersion, fibre length and multiple layering, on the tensile properties of these composites. It was found that the tensile strength was improved by better dispersion of fibre strands. Tensile strength and stiffness of the composite samples were also improved by an increase in fibre length and by multiple layering. [ABSTRACT FROM AUTHOR]

The performance of a pump turbine in pump mode is of great importance to a pumped storage power plant. In order to obtain pump characteristics of a pump turbine, 3D steady simulations were carried out by solving Reynolds-averaged Navier-Stokes (RANS) equations using different two-equation turbulence models. Compared with the experimental data, SST k-ω turbulence model was chosen to simulate external characteristic curves under 32mm, 22mm and 18mm guide vanes openings. The results show a good agreement with the experimental data, especially near the best efficiency point. Finally, the detailed analysis was conducted within vaned distributor for these three guide vanes openings. The variation of flow field, pressure filed, energy characteristic and loss with the discharge and guide vanes opening were obtained through the analysis. This research could provide a basic understanding on pump characteristics of a pump turbine for designer. [ABSTRACT FROM AUTHOR]

Electrospinning is a versatile method for making nanofibres from polymer solution. Hydroxypropyl-β-cyclodextrin (HP-β-CD) is electrospun from aqueous solution by blending with non-toxic, biocompatible, synthetic polymer poly(ethylene oxide) (PEO). The aqueous solutions containing 70:30 HP-β-CD/PEO polymer blend with 8 wt.% concentration were electrospun to study the effects of process parameters on fibre morphology. Electrospinning was carried out at variable feed rate, applied voltage and working distance to see the effects on process stability and fibre diameter. Scanning electron microscope images showed that increasing feed rate, applied voltage and working distance promote bead formation in the fibre. The average diameter of the nanofibres was measured using ImageJ software. It was observed that the fibre diameter increased with increasing the feed rate and applied voltage. In contrast, the diameter of the fibres decreased with increasing the working distance up to a certain level. Further increase of the working distance produced beaded fibres. The ultimate objective of this study was optimize the electrospinning parameters to obtain bead-free HP-β-CD/PEO nanofibres. The results revealed that a feed rate of 0.5–1.0 ml/h, a working distance of 10–14 cm and an applied voltage of 5–7 kV have been found to produce smooth PEO loaded HP-β-CD nanofibres. [ABSTRACT FROM PUBLISHER]

Objective To investigate the mechanism of lncRNA MEG3 (MEG3) modulating the proliferation and metastasis of pancreatic cancer cells via regulating miR-543/PTEN axis. Methods qRT-PCR was applied to detect the expression of MEG3 in pancreatic cancer tissues and cell lines. The effect of MEG3 overexpression on the proliferation, invasion and epithelial mesenchymal transition (EMT) of PANC-1 cells were determined by CCK-8, Transwell assay and Western blot, respectively. The interaction between MEG3, miR-543 and PTEN were verified by dual-luciferase reporter gene assay. Furthermore, we investigated the effect of MEG3 on proliferation, invasion and EMT of PANC-1 cells through regulating miR-543/PTEN axis. Results MEG3 expression was down-regulated in pancreatic cancer tissues and cell lines. Meanwhile, the overexpression of MEG3 inhibited the proliferation, invasion and EMT of PANC-1 cells in vitro. MEG3 suppressed the proliferation, invasion and EMT of PANC-1 cells via decreasing the inhibitory effect of miR-543 on PTEN in vitro. Conclusion MEG3 inhibits the proliferation, invasion and EMT of PANC-1 cells by regulating miR-543/PTEN axis, which may provide potential molecular targets for early diagnosis and treatment of pancreatic cancer.

The effects of fluorocarbon finishing of hollow and solid polyester/wool were studied in order to establish the processing behavior and performance characteristics of the treated fabrics. Polyester/wool blended fabrics before and after dyeing were treated with different fluorochemicals; their liquid repellency after washing and dry cleaning was evaluated. Fabric mechanical properties were compared by measuring tensile strength and low stress mechanical properties. The results indicate that the finishing agent formulation has a great effect on the fabrics repellent properties. Studying the fluorocarbon chain reorientation during laundering and dry cleaning revealed that each fluorocarbon has different ability to retrieve its original configuration via air drying with subsequent necessity of hot pressing to reach acceptable repellency. Also, the effect of hollow fibers on fabric mechanical properties is practically insignificant. The low stress mechanical properties indicate only relatively small differences among the samples. However, finishing with all chemicals and methods resulted in higher friction between the fibers and yarns, and in increased bending and shear rigidity, and shear hysteresis. [ABSTRACT FROM AUTHOR]

A new technique of manufacturing thermoset composites using chopped fibreglass strands was investigated during this research work. This technique involved manufacturing of fibreglass nonwoven webs by the wet-laid method, these webs were then used as reinforcement for making composites. The wet-laying process allows the opening of the fibreglass strands to single fibres so that the fibres are dispersed more uniformly within the composite. The in-plane fibre orientation distribution in these nonwoven webs was random and the composites manufactured from these webs have more in-plane isotropic properties. The effect of key process variables i.e. dispersion, fibre length and multiple layering on the density, fibre content and void content of the composites was studied. It was found that layering increased the fibre content and decreased the void content. Dispersion and increase in fibre length also decreased the void content. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Coronary artery disease (CAD) remains one of the major causes of death worldwide. Despite considerable advances in the prevention and treatment of CAD, its complications, morbidity and mortality still remain very high, and vary widely across different ethnic groups. MATERIALS AND METHODS: To detect genes involved in the development of CAD, we collected gene expression studies in the blood samples of CAD patients from different continents by searching the Gene Expression Omnibus database (GEO), performed a comparative analysis of gene expression between CAD patients and normal controls (NC) in each continent and identified the common set of differentially expressed genes (DEGs) between CAD patients and NC across different continents. PPI networks of the common set of DEGs were established by Cytoscape software to understand their biological role in CAD. RESULTS: A total of 575, 868 and 476 genes were identified to be significantly differentially expressed between CAD patients and NC in Asia, Europe and North America. 24 genes were found common in three different continents, and 6 genes were previously linked to CAD or atherosclerosis. In the PPIs network the significant hub proteins contained IRF4 (Degree = 23), PLAUR (Degree = 17) and HIST1H2AE (Degree = 15). CONCLUSIONS: Not only did we detect gene expression differences in the blood samples between CAD and NC in Asia, Europe and North America population, but analysis of the three population groups revealed a common set of 24 genes regardless of differences related to race, ethnicity, lifestyle, and environmental factor which may provide key factors to understand the pathogenesis of CAD and lead to development of diagnostic markers and/or effective therapeutic strategies. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) shell-structured PLA/Flax biocomposites were fabricated using a novel method incorporating the 3D nonwoven web-forming process. PLA and flax fibers were blended in the fiber opening stage and converted to webs on the 3D mold using the air-laying principle. The 3D webs were then consolidated by through-air thermal bonding. The compression molding technique was used finally to convert the 3D webs to the biocomposites. The relationship between the main process parameters and the properties of the biocomposites was investigated. The results show that with increasing flax fiber content, the crush failure load, total energy absorption, specific energy absorption, and crush efficiency increased. The crushing properties decreased with increased molding temperature, but the crushing properties are not significantly affected by the molding time. The physical properties of 3D biocomposites were also evaluated and the appropriate processing parameters for 3D biocomposites were established. [ABSTRACT FROM AUTHOR]

Digital reconstruction or tracing of 3D tree-like neuronal structures from optical microscopy images is essential for understanding the functionality of neurons and reveal the connectivity of neuronal networks. Despite the existence of numerous tracing methods, reconstructing a neuron from highly noisy images remains challenging, particularly for neurites with low and inhomogeneous intensities. Conducting deep convolutional neural network (CNN)-based segmentation prior to neuron tracing facilitates an approach to solving this problem via separation of weak neurites from a noisy background. However, large manual annotations are needed in deep learning-based methods, which is labor-intensive and limits the algorithm’s generalization for different datasets. In this study, we present a weakly supervised learning method of a deep CNN for neuron reconstruction without manual annotations. Specifically, we apply a 3D residual CNN as the architecture for discriminative neuronal feature extraction. We construct the initial pseudo-labels (without manual segmentation) of the neuronal images on the basis of an existing automatic tracing method. A weakly supervised learning framework is proposed via iterative training of the CNN model for improved prediction and refining of the pseudo-labels to update training samples. The pseudo-label was iteratively modified via mining and addition of weak neurites from the CNN predicted probability map on the basis of their tubularity and continuity. The proposed method was evaluated on several challenging images from the public BigNeuron and Diadem datasets, to fMOST datasets. Owing to the adaption of 3D deep CNNs and weakly supervised learning, the presented method demonstrates effective detection of weak neurites from noisy images and achieves results similar to those of the CNN model with manual annotations. The tracing performance was significantly improved by the proposed method on both small and large datasets (>100 GB). Moreover, the proposed method proved to be superior to several novel tracing methods on original images. The results obtained on various large-scale datasets demonstrated the generalization and high precision achieved by the proposed method for neuron reconstruction.

Computer-assisted cervical screening is an effective method to save the doctors’ workload and improve their work efficiency. Usually, the correct classification of cervical cells depends on the nuclear segmentation effect and the extraction of nuclear features. However, the precise nucleus segmentation remains a huge challenge, especially for densely distributed nucleus. Moreover, previous cellular classification methods are mostly based on morphological features of nucleus size or color. Those individual features can make accurate classification for severe lesions, but not for mild lesions. In this paper, we propose an accurate instance segmentation algorithm and propose cognition-based features to identify cervical cancer cells. Different from previous individual nucleus features, we also propose population features and cognition-based features according to the Bethesda System (TBS) for reporting cervical cytology and the diagnostic experience of the cytologists. The results showed that the segmentation achieves better success in complex situations than that by traditional segmentation algorithms. Besides, the cell classification via cognition-based features also help us find out more about less severe lesions’ nuclei than that based on conventional features of individual nucleus, meaning an improvement of classification accuracy for cervical screening.

Taking into consideration the disadvantages of the serial structure controller-slow operation speed, poor grid current quality for the present grid-connected invert, the authors proposed a new grid-connected invert architecture, which is based on SOPC control technology on FPGA platform. It adopts the direct current PI control strategy with grid voltage feed-forward and uses hardware to realize algorithm, which improved the running speed and the overall performance of system. Meanwhile, designed regulator parameters for the control strategy and constructed grid-connected control system IP hard core for the invert in this paper. Experimental results of 1 kW prototype show that this method has good grid current quality and strong synchronous tracking capability.

Abstract Background Hyperfibrinogenemia is increasingly being recognized as an important risk factor related to cancer stage, development and outcomes. We evaluated whether preoperative serum fibrinogen levels predict recurrence of papillary thyroid carcinoma (PTC). Methods We retrospectively collected data for 1023 PTC patients who underwent surgery at our institution from Aug 2014 to Aug 2016. In total, 414 patients (from Aug 2014 to Dec 2015) were used as the training set to build the model, and 609 patients (from Jan 2016 to Aug 2016) were used as the testing set to validate the model. Results In the training set, PTC cases with high serum fibrinogen levels were more likely to have multiple PTCs (P = 0.001) and to exhibit surrounding tissue or organ invasion (both P

Yanping Gong, Genpeng Li, Jianyong Lei, Jiaying You, Ke Jiang, Zhihui Li, Rixiang Gong, Jingqiang Zhu Thyroid and Parathyroid Surgery Center, West China Hospital of Sichuan University, Chengdu, China Background: The optimal treatment strategy for papillary thyroid microcarcinoma (PTMC) has remained controversial. The purpose of this study was to provide a new reference value for PTMC to aid the selection of optimal management for minute lesions.Patients and methods: A pool of 1176 consecutive patients who met the inclusion criteria were ultimately enrolled in this study. The correlation of papillary thyroid carcinoma (PTC) tumor size and lymph node metastasis was analyzed. Receiver operating characteristic curve studies were conducted to identify the reference value by determining the optimal cut-off point of size related to lymph node metastasis. To validate our results, all selected patients were divided into two groups according to the cut-off point and some of the prognostic factors were compared.Results: A moderate significant correlation was found between the tumor size and the average number of lymph node metastases (r=0.502, P8.5 mm), a tumor size ≤8.5 mm in diameter may be favorable to discriminate PTMC from PTC and aid the selection of optimal management. Keywords: thyroid neoplasms, carcinoma, papillary, lymph nodes