151 research outputs found
Automated and High Speed Machine Design for Telecommunication Products
This research focuses on an automated and high speed machine design, which is assembling the bronze wire inside the plastic block, according to the manufacturing and production specification. In this design project, automated system performs special kind of operation in assembly line and it divided in five different stations. The function at first station is wire loading, feeding and straightening the wire. The function in second station is uploading the plastic block into the assembly line and holding the block precisely for inserting the bronze wire. The third station include of wire inserting into the plastic block and cut wire at desire length. The fourth station takes care of bending wire and final station take care of inspection of final assembly product by using appropriate sensors techniques. This project is mainly focus on utilization of automated machinery with simple tooling and fixture with low cost, which properly inspected at each station and easier to maintain in working at "high speed" repeatedly. It also explains major design problems and understands of engineering technology and limitations
Deubiquitinase USP47/UBP64E Regulates β-Catenin Ubiquitination and Degradation and Plays a Positive Role in Wnt Signaling
Wnt signaling plays important roles in development and tumorigenesis. A central question about the Wnt pathway is the regulation of β-catenin. Phosphorylation of β-catenin by CK1α and GSK3 promotes β-catenin binding to β-TrCP, leading to β-catenin degradation through the proteasome. The phosphorylation and ubiquitination of β-catenin have been well characterized; however, it is unknown whether and how a deubiquitinase is involved. In this study, by screening RNA interference (RNAi) libraries, we identified USP47 as a deubiquitinase that prevents β-catenin ubiquitination. Inactivation of USP47 by RNAi increased β-catenin ubiquitination, attenuated Wnt signaling, and repressed cancer cell growth. Furthermore, USP47 deubiquitinates itself, whereas β-TrCP promotes USP47 ubiquitination through interaction with an atypical motif in USP47. Finally, in vivo studies in the Drosophila wing suggest that UBP64E, the USP47 counterpart in Drosophila, is required for Armadillo stabilization and plays a positive role in regulating Wnt target gene expression
Regional multi-compartment ecological risk assessment:establishing cadmium pollution risk in the northern Bohai Rim, China
Ecological risk assessment (ERA) has been widely applied in characterizing the risk of chemicals to organisms and ecosystems. The paucity of toxicity data on local biota living in the different compartments of an ecosystem and the absence of a suitable methodology for multi-compartment spatial risk assessment at the regional scale has held back this field. The major objective of this study was to develop a methodology to quantify and distinguish the spatial distribution of risk to ecosystems at a regional scale. A framework for regional multi-compartment probabilistic ecological risk assessment (RMPERA) was constructed and corroborated using a bioassay of a local species. The risks from cadmium (Cd) pollution in river water, river sediment, coastal water, coastal surface sediment and soil in northern Bohai Rim were examined. The results indicated that the local organisms in soil, river, coastal water, and coastal sediment were affected by Cd. The greatest impacts from Cd were identified in the Tianjin and Huludao areas. The overall multi-compartment risk was 31.4% in the region. The methodology provides a new approach for regional multi-compartment ecological risk assessment
Backpressure based traffic signal control considering capacity of downstream links
Congestion is a kind of expression of instability of traffic network. Traffic signal control keeping traffic network stable can reduce the congestion of urban traffic. In order to improve the efficiency of urban traffic network, this study proposes a decentralized traffic signal control strategy based on backpressure algorithm used in Wi-Fi mesh networks for packets routing. Backpressure based traffic signal control algorithm can stabilize urban traffic network and achieve maximum throughput. Based on original backpressure algorithm, the variant parameter and penalty function are considered to balance the queue differential and capacity of downstream links in urban traffic network. For each traffic phase of intersections, phase weight is computed using queue differential and capacity of downstream links, which fixed the deficiency of infinite queue capacity in original backpressure algorithm. It is proved that the extended backpressure traffic signal control algorithm can maintain stability of urban traffic network, and also can prevent queue spillback, so as to improve performance of whole traffic network. Simulations are carried out in Vissim using Vissim COM programming interface and Visual Studio development tools. Evaluation results illuminate that it can get better performance than the backpressure algorithm just based on queue length differential in average queue length and delay of traffic network
Perfluoroalkyl acids (PFAAs) in indoor and outdoor dusts around a mega fluorochemical industrial park in China: implications for human exposure
The manufacture of fluorochemicals can lead to high levels of perfluoroalkyl acids (PFAAs) contaminating the surrounding environment and consequently elevated exposure to the local residents. In this study, measurements of PFAAs associated with indoor and outdoor dusts around a mega fluorochemical industrial park (FIP) were made. Perfluorooctanoic acid (PFOA) and short-chain perfluoroalkyl carboxylic acids (C4-C7 PFCAs) were the predominant forms in all samples. The signature of the PFAAs in dusts in the local area matched that found within the FIP complex. The contamination plume in the local area could be linked to the prevailing wind direction starting from the FIP. The concentrations decreased exponentially with distance from the FIP (noticeably in the first 5 km). PFAAs contamination could be detected at the most distant location, 20 km away from the FIP. The relatively small size of this high contamination zone suggested that the PFAAs were associated with large/dense dust particles with limited ability to be transported far by the air. The concentrations of PFAAs were higher in indoor dust (73-13,500 ng/g, median: 979 ng/g) than those in outdoor dust (5-9,495 ng/g, median: 62 ng/g) at every location. The highest estimated daily intake of PFOA via dust ingestion (26.0 ng/kg.bw/day) was for toddlers (2-5 yrs) living in 2 km away from the FIP, which is posing human health risk, though within the provisional tolerable daily intake values
Spontaneously immortalised bovine mammary epithelial cells exhibit a distinct gene expression pattern from the breast cancer cells
<p>Abstract</p> <p>Background</p> <p>Spontaneous immortalisation of cultured mammary epithelial cells (MECs) is an extremely rare event, and the molecular mechanism behind spontaneous immortalisation of MECs is unclear. Here, we report the establishment of a spontaneously immortalised bovine mammary epithelial cell line (BME65Cs) and the changes in gene expression associated with BME65Cs cells.</p> <p>Results</p> <p>BME65Cs cells maintain the general characteristics of normal mammary epithelial cells in morphology, karyotype and immunohistochemistry, and are accompanied by the activation of endogenous <it>bTERT </it>(bovine Telomerase Reverse Transcriptase) and stabilisation of the telomere. Currently, BME65Cs cells have been passed for more than 220 generations, and these cells exhibit non-malignant transformation. The expression of multiple genes was investigated in BME65Cs cells, senescent BMECs (bovine MECs) cells, early passage BMECs cells and MCF-7 cells (a human breast cancer cell line). In comparison with early passage BMECs cells, the expression of senescence-relevant apoptosis-related gene were significantly changed in BME65Cs cells. P16<sup>INK4a </sup>was downregulated, p53 was low expressed and Bax/Bcl-2 ratio was reversed. Moreover, a slight upregulation of the oncogene <it>c-Myc</it>, along with an undetectable level of breast tumor-related gene <it>Bag-1 </it>and <it>TRPS-1</it>, was observed in BME65Cs cells while these genes are all highly expressed in MCF-7. In addition, <it>DNMT1 </it>is upregulated in BME65Cs. These results suggest that the inhibition of both senescence and mitochondrial apoptosis signalling pathways contribute to the immortality of BME65Cs cells. The expression of <it>p53 </it>and <it>p16</it><sup><it>INK4a </it></sup>in BME65Cs was altered in the pattern of down-regulation but not "loss", suggesting that this spontaneous immortalization is possibly initiated by other mechanism rather than gene mutation of <it>p53 </it>or <it>p16</it><sup><it>INK4a</it></sup>.</p> <p>Conclusions</p> <p>Spontaneously immortalised BME65Cs cells maintain many characteristics of normal BMEC cells and exhibit non-malignant transformation. Although this cell line displays altered patterns of gene expression, it is clearly distinct from malignant breast cancer cell line. It showed that co-inhibition of cellular senescence and mitochondrial apoptosis pathways coordinates BME65Cs cells immortalisation. Additionally, mechanisms other than gene mutation are likely to be involved in regulation of cellular functions. This study provides an insight into the relationship between cell senescence and immortalisation. BME65Cs cells will be useful in future studies of cellular senescence and tumorigenesis.</p
Which metal represents the greatest risk to freshwater ecosystem in Bohai Region of China?
Metals discharged from industrial effluents, agricultural wastewater, and sewage runoff by rapid urbanization are of concern as contaminants of freshwater ecosystem because of their persistence and high toxicity to aquatic organisms. This study attempted to identify which metal posed the greatest risk to freshwater ecosystem in the Bohai Region, China. The metals arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), zinc (Zn), lead (Pb), nickel (Ni), mercury (Hg), iron (Fe), and manganese (Mn) were compared against norfloxacin and gamma-hexachlorocyclohexane (lindane). By comparing the median reported environmental and ecotoxicity concentrations, it showed that Cu, Fe, Zn, Mn, and Cr were the top five metals of concern. Of these, Cu was deemed to represent the highest risk and Hg the lowest risk. The risks for all metals were higher than those for norfloxacin and lindane. Almost all the metals except Hg had water concentrations that exceeded levels where ecotoxicity effects had been recorded in the literature. A comparison with the measurements across the UK rivers suggested that all metals examined had water concentrations about 5- to 10- fold higher than the UK median values except for Cu, Fe, Cd, and Pb. The Fuyang River, a tributary of the Haihe River Basin, seemed to be the location with the highest metal concentrations. However, comparing the post- 2010 period to 2000–2009, concentrations of all the metals had fallen except for Fe and Mn, so risks have decreased over the last 7 yr with the greatest improvements for Cd and Pb. While metals still pose high risks to freshwater ecosystem in this region, there is encouragement that some control measures are taken into effect
Deep Learning for Feynman's Path Integral in Strong-Field Time-Dependent Dynamics
Feynman's path integral approach is to sum over all possible spatio-temporal
paths to reproduce the quantum wave function and the corresponding time
evolution, which has enormous potential to reveal quantum processes in
classical view. However, the complete characterization of quantum wave function
with infinite paths is a formidable challenge, which greatly limits the
application potential, especially in the strong-field physics and attosecond
science. Instead of brute-force tracking every path one by one, here we propose
deep-learning-performed strong-field Feynman's formulation with
pre-classification scheme which can predict directly the final results only
with data of initial conditions, so as to attack unsurmountable tasks by
existing strong-field methods and explore new physics. Our results build up a
bridge between deep learning and strong-field physics through the Feynman's
path integral, which would boost applications of deep learning to study the
ultrafast time-dependent dynamics in strong-field physics and attosecond
science, and shed a new light on the quantum-classical correspondence
Which persistent organic pollutants in the rivers of the Bohai region of China represent the greatest risk to the local ecosystem?
Freshwater aquatic organisms can be exposed to hundreds of persistent organic pollutants (POPs) discharged by natural and anthropogenic activities. Given our limited resources it is necessary to identify, from the existing evidence, which is the greatest threat so that control measures can be targeted wisely. The focus of this study was to rank POPs according to the relative risk they represent for aquatic organisms in rivers in the Bohai Region, China. A list of 14 POPs was compiled based on the available data on their presence in these rivers and ecotoxicological data. Those that were widely detected were benzo[a]pyrene, p,p'-DDE, p,p'-DDT, endrin, fluoranthene, heptachlor, hexabromocyclododecane, hexachlorobenzene, alpha-hexachlorocyclohexane, gamma-hexachlorocyclohexane, naphthalene, perfluorooctanoic acid, perfluorooctane sulfonate and phenanthrene. Effect concentrations were compiled for Chinese relevant and standard test species and compared with river aqueous concentrations. Only bed-sediment concentrations were available so water levels were calculated based on the known local sediment organic carbon concentration and the Koc. The POPs were ranked on the ratio between the median river and median effect concentrations. Of the POPs studied, fluoranthene was ranked as the highest threat, followed by phenanthrene, naphthalene and p,p'-DDE. The risk from p,p'-DDE may be magnified due to being highly bioaccumulative. However, the greatest overlap between river concentrations and effect levels was for lindane. Overall, fish was the most sensitive species group to the risks from POPs. Hotspots with the highest concentrations and hence risk were mainly associated with watercourses draining in Tianjin, the biggest city in the Bohai Region
Associations of Functional MicroRNA Binding Site Polymorphisms in IL23/Th17 Inflammatory Pathway Genes with Gastric Cancer Risk
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