| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
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| 3. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 4. |
- Kristan, Matej, et al.
(författare)
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The Visual Object Tracking VOT2015 challenge results
- 2015
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Ingår i: Proceedings 2015 IEEE International Conference on Computer Vision Workshops ICCVW 2015. - : IEEE. - 9780769557205 ; , s. 564-586
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Konferensbidrag (refereegranskat)abstract
- The Visual Object Tracking challenge 2015, VOT2015, aims at comparing short-term single-object visual trackers that do not apply pre-learned models of object appearance. Results of 62 trackers are presented. The number of tested trackers makes VOT 2015 the largest benchmark on short-term tracking to date. For each participating tracker, a short description is provided in the appendix. Features of the VOT2015 challenge that go beyond its VOT2014 predecessor are: (i) a new VOT2015 dataset twice as large as in VOT2014 with full annotation of targets by rotated bounding boxes and per-frame attribute, (ii) extensions of the VOT2014 evaluation methodology by introduction of a new performance measure. The dataset, the evaluation kit as well as the results are publicly available at the challenge website(1).
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| 5. |
- Chiu, Chun Chien, et al.
(författare)
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Presence of Delocalized Ti 3d Electrons in Ultrathin Single-Crystal SrTiO3
- 2022
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 22:4, s. 1580-1586
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Tidskriftsartikel (refereegranskat)abstract
- Strontium titanate (STO), with a wide spectrum of emergent properties such as ferroelectricity and superconductivity, has received significant attention in the community of strongly correlated materials. In the strain-free STO film grown on the SrRuO3 buffer layer, the existing polar nanoregions can facilitate room-temperature ferroelectricity when the STO film thickness approaches 10 nm. Here we show that around this thickness scale, the freestanding STO films without the influence of a substrate show the tetragonal structure at room temperature, contrasting with the cubic structure seen in bulk form. The spectroscopic measurements reveal the modified Ti-O orbital hybridization that causes the Ti ion to deviate from its nominal 4+ valency (3d0 configuration) with excess delocalized 3d electrons. Additionally, the Ti ion in TiO6 octahedron exhibits an off-center displacement. The inherent symmetry lowering in ultrathin freestanding films offers an alternative way to achieve tunable electronic structures that are of paramount importance for future technological applications.
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| 6. |
- Kanoni, Stavroula, et al.
(författare)
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Implicating genes, pleiotropy, and sexual dimorphism at blood lipid loci through multi-ancestry meta-analysis.
- 2022
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Ingår i: Genome biology. - : Springer Science and Business Media LLC. - 1474-760X .- 1465-6906 .- 1474-7596. ; 23:1
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Tidskriftsartikel (refereegranskat)abstract
- Genetic variants within nearly 1000 loci are known to contribute to modulation of blood lipid levels. However, the biological pathways underlying these associations are frequently unknown, limiting understanding of these findings and hindering downstream translational efforts such as drug target discovery.To expand our understanding of the underlying biological pathways and mechanisms controlling blood lipid levels, we leverage a large multi-ancestry meta-analysis (N=1,654,960) of blood lipids to prioritize putative causal genes for 2286 lipid associations using six gene prediction approaches. Using phenome-wide association (PheWAS) scans, we identify relationships of genetically predicted lipid levels to other diseases and conditions. We confirm known pleiotropic associations with cardiovascular phenotypes and determine novel associations, notably with cholelithiasis risk. We perform sex-stratified GWAS meta-analysis of lipid levels and show that 3-5% of autosomal lipid-associated loci demonstrate sex-biased effects. Finally, we report 21 novel lipid loci identified on the X chromosome. Many of the sex-biased autosomal and X chromosome lipid loci show pleiotropic associations with sex hormones, emphasizing the role of hormone regulation in lipid metabolism.Taken together, our findings provide insights into the biological mechanisms through which associated variants lead to altered lipid levels and potentially cardiovascular disease risk.
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| 7. |
- You, Xiaohu, et al.
(författare)
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Towards 6G wireless communication networks: vision, enabling technologies, and new paradigm shifts
- 2021
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Ingår i: Science China Information Sciences. - : Science Press. - 1674-733X .- 1869-1919. ; 64:1
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Forskningsöversikt (refereegranskat)abstract
- The fifth generation (5G) wireless communication networks are being deployed worldwide from 2020 and more capabilities are in the process of being standardized, such as mass connectivity, ultra-reliability, and guaranteed low latency. However, 5G will not meet all requirements of the future in 2030 and beyond, and sixth generation (6G) wireless communication networks are expected to provide global coverage, enhanced spectral/energy/cost efficiency, better intelligence level and security, etc. To meet these requirements, 6G networks will rely on new enabling technologies, i.e., air interface and transmission technologies and novel network architecture, such as waveform design, multiple access, channel coding schemes, multi-antenna technologies, network slicing, cell-free architecture, and cloud/fog/edge computing. Our vision on 6G is that it will have four new paradigm shifts. First, to satisfy the requirement of global coverage, 6G will not be limited to terrestrial communication networks, which will need to be complemented with non-terrestrial networks such as satellite and unmanned aerial vehicle (UAV) communication networks, thus achieving a space-air-ground-sea integrated communication network. Second, all spectra will be fully explored to further increase data rates and connection density, including the sub-6 GHz, millimeter wave (mmWave), terahertz (THz), and optical frequency bands. Third, facing the big datasets generated by the use of extremely heterogeneous networks, diverse communication scenarios, large numbers of antennas, wide bandwidths, and new service requirements, 6G networks will enable a new range of smart applications with the aid of artificial intelligence (AI) and big data technologies. Fourth, network security will have to be strengthened when developing 6G networks. This article provides a comprehensive survey of recent advances and future trends in these four aspects. Clearly, 6G with additional technical requirements beyond those of 5G will enable faster and further communications to the extent that the boundary between physical and cyber worlds disappears.
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| 8. |
- Ablikim, M., et al.
(författare)
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Measurements of (XcJ)-> K+K-K+K- decays
- 2006
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 642:3, s. 197-202
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Tidskriftsartikel (refereegranskat)abstract
- Using 14M psi(2S) events taken with the BESII detector, chi(cJ) -> 2(K+K-) decays are studied. For the four-kaon final state, the branching fractions are B(chi(c0,1,2) ->.2(K+K-)) = (3.48 +/- 0.23 +/- 0.47) x 10(-3), (0.70 +/- 0.13 +/- 0.10) x 10(-3), and (2.17 +/- 0.20 +/- 0.31) x 10(-3). For the phi K+K- final state, the branching fractions, which are measured for the first time, are B(chi(c0,1,2) -> phi K+K-) = (1.03 +/- 0.22 +/- 0.15) x 10(-3), (0.46 +/- 0.16 +/- 0.06) x 10(-3), and (1.67 +/- 0.26 +/- 0.24) x 10(-4). For the phi phi final state, B(chi(c0,2) -> phi phi) = (0.94 +/- 0.21 +/- 0.13) x 10(-3) and (1.70 +/- 0.30 +/- 0.25) x 10(-3).
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| 9. |
- Huang, Yuting, et al.
(författare)
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Host-Guest Strategy Enabling Nonhalogenated Solvent Processing for High-Performance All-Polymer Hosted Solar Cells
- 2023
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Ingår i: Chinese journal of chemistry. - : WILEY-V C H VERLAG GMBH. - 1001-604X .- 1614-7065. ; 41:9, s. 1066-1074
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Tidskriftsartikel (refereegranskat)abstract
- The power conversion efficiencies (PCEs) of all-polymer solar cells (all-PSCs), usually processed from low-boiling-point and toxic solvents, have reached high values of 18%. However, poor miscibility and uncontrollable crystallinity in polymer blends lead to a notable drop in the PCEs when using green solvents, limiting the practical development of all-PSCs. Herein, a third component (guest) BTO was employed to optimize the miscibility and enhance the crystallinity of PM6/PY2Se-F host film processed from green solvent toluene (TL), which can effectively suppress the excessive aggregation of PY2Se-F and facilitate a nano-scale interpenetrating network morphology for exciton dissociation and charge transport. As a result, TL-processed all-polymer hosted solar cells (all-PHSCs) exhibited an impressive PCE of 17.01%. Moreover, the strong molecular interaction between the host and guest molecules also enhances the thermal stability of the devices. Our host-guest strategy provides a unique approach to developing high-efficiency and stable all-PHSCs processed from green solvents, paving the way for the industrial development of all-PHSCs.
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| 10. |
- Jiang, Dong-yi, et al.
(författare)
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Surface water quality and potential health risk assessments in Changsha-Zhuzhou-Xiangtan section of Xiangjiang River, China
- 2019
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Ingår i: journal of central south university. - : Springer Science and Business Media LLC. - 2095-2899 .- 2227-5223. ; 26:12, s. 3252-3260
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Tidskriftsartikel (refereegranskat)abstract
- The Changsha-Xiangtan-Zhuzhou City Group is a heavy industrial district and accepted as the serious pollution area in the Xiangjiang River basin. In this study, 7 metals (Pb, Hg, Cd, As, Zn, Cu and Se) and the river water quality parameters including pH, dissolved oxygen (DO), Escherichia coli (E. coli), potassium permanganate index (CODMn), dichromate oxidizability (CODCr), five-day biochemical oxygen demand (BOD5), ammonia nitrogen (NH4+-N), total nitrogen (TN), total phosphorus (TP) and fluoride (F-) in 18 sampling sites of the Changsha-Xiangtan-Zhuzhou section are monthly monitored in 2016, which is the year to step into the second stage of the Xiangjiang River Heavy Metal Pollution Control Implementation Plan. It is found that E. coli, TN and TP are the main pollutants in the Changsha-Zhuzhou-Xiangtan section, and the pollution of heavy metal is not serious but As with potential risk to local people especially children should be concerned. In addition, Xiangtan city is mainly featured with heavy metal pollution, while Zhuzhou and Changsha city are both featured with other pollutants from municipal domestic sewage.
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| 11. |
- Liao, Wenlong, et al.
(författare)
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Simple Data Augmentation Tricks for Boosting Performance on Electricity Theft Detection Tasks
- 2023
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Ingår i: IEEE transactions on industry applications. - : Institute of Electrical and Electronics Engineers (IEEE). - 0093-9994 .- 1939-9367. ; 59:4, s. 1-12
-
Tidskriftsartikel (refereegranskat)abstract
- In practical engineering, electricity theft detection is usually performed on highly imbalanced datasets (i.e., the number of fraudulent samples is much smaller than the benign ones), which limits the accuracy of the classifier. To alleviate the data imbalance problem, this article proposes simple data augmentation tricks (SDAT) to boost performance on electricity theft detection tasks. SDAT includes five simple but powerful operations: adding noises to electricity consumption readings, drifting values of electricity consumption readings, quantizing electricity consumption readings to a level set, adding a fixed value to electricity consumption readings, and adding changeable values to electricity consumption readings. In addition, eight potential tricks are also mentioned. Numerical simulations are conducted on a real-world dataset. The simulation results show that SDAT can significantly boost the performance of different classifiers, especially for small datasets. Besides, specific suggestions on how to select parameters of SDAT are provided for its migration use to other datasets.
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| 12. |
- Ma, Tao, et al.
(författare)
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Genomic insights into salt adaptation in a desert poplar
- 2013
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 4, s. 2797-
-
Tidskriftsartikel (refereegranskat)abstract
- Despite the high economic and ecological importance of forests, our knowledge of the genomic evolution of trees under salt stress remains very limited. Here we report the genome sequence of the desert poplar, Populus euphratica, which exhibits high tolerance to salt stress. Its genome is very similar and collinear to that of the closely related mesophytic congener, P. trichocarpa. However, we find that several gene families likely to be involved in tolerance to salt stress contain significantly more gene copies within the P. euphratica lineage. Furthermore, genes showing evidence of positive selection are significantly enriched in functional categories related to salt stress. Some of these genes, and others within the same categories, are significantly upregulated under salt stress relative to their expression in another salt-sensitive poplar. Our results provide an important background for understanding tree adaptation to salt stress and facilitating the genetic improvement of cultivated poplars for saline soils.
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| 13. |
- Chen, Bo, et al.
(författare)
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Deep Contextualized Compressive Offloading for Images
- 2021
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Ingår i: SenSys 2021 - Proceedings of the 2021 19th ACM Conference on Embedded Networked Sensor Systems. - New York, NY, USA : ACM. ; , s. 467-473
-
Konferensbidrag (refereegranskat)abstract
- Recent years have witnessed sensors becoming an indispensable part of our life with the camera being one of the most popular and widely deployed sensors. The camera gives rise to numerous vision-based IoT applications that generate high-level understandings of a live video stream by performing analysis on end devices like mobile or embedded devices. Typically, these applications are built with deep learning (DL) models to conduct complex vision tasks, e.g., image classification and object detection. Due to the prohibitive cost of running DL models on end devices close to the camera and with limited computation capabilities, it is widely adopted to offload the computation to a nearby powerful edge server. However, there is a gap between the restricted offloading bandwidth of the end device and the large volume of image data incurred by the live video stream. In this paper, we present Deep Contextualized Compressive Offloading for Images (DCCOI), a lightweight, context-aware, and bandwidth-efficient offloading framework for images. DCCOI consists of the spatial-adaptive encoder, a lightweight neural network, to spatial-adaptively compress the image, and the generative decoder for reconstructing the image from the compressed data. In contrast to existing DL-based encoders, the spatial-adaptive encoder allows an image region to be encoded into different numbers of feature values based on the information in it. This offers a variable-length coding method for image compression, which is a more optimal way for compression than the fix-length coding method took by existing DL-based compression approaches and demonstrates superior accuracy-compression rate trade-offs. We evaluate DCCOI against several baseline compression techniques while serving an object detection-based application. The results show that DCCOI roughly reduces the offloading size of JPEG by a factor of 9 and DeepCOD, the state-of-the-art offloading approach, by 20% with similar accuracy and a compression overhead less than 50ms.
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| 14. |
- Ching, Tao-Chung, et al.
(författare)
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The JCMT BISTRO-2 Survey: Magnetic Fields of the Massive DR21 Filament
- 2022
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 941:2
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Tidskriftsartikel (refereegranskat)abstract
- We present 850 mu m dust polarization observations of the massive DR21 filament from the B-fields In STar-forming Region Observations (BISTRO) survey, using the POL-2 polarimeter and the SCUBA-2 camera on the James Clerk Maxwell Telescope. We detect ordered magnetic fields perpendicular to the parsec-scale ridge of the DR21 main filament. In the subfilaments, the magnetic fields are mainly parallel to the filamentary structures and smoothly connect to the magnetic fields of the main filament. We compare the POL-2 and Planck dust polarization observations to study the magnetic field structures of the DR21 filament on 0.1-10 pc scales. The magnetic fields revealed in the Planck data are well-aligned with those of the POL-2 data, indicating a smooth variation of magnetic fields from large to small scales. The plane-of-sky magnetic field strengths derived from angular dispersion functions of dust polarization are 0.6-1.0 mG in the DR21 filament and similar to 0.1 mG in the surrounding ambient gas. The mass-to-flux ratios are found to be magnetically supercritical in the filament and slightly subcritical to nearly critical in the ambient gas. The alignment between column density structures and magnetic fields changes from random alignment in the low-density ambient gas probed by Planck to mostly perpendicular in the high-density main filament probed by James Clerk Maxwell Telescope. The magnetic field structures of the DR21 filament are in agreement with MHD simulations of a strongly magnetized medium, suggesting that magnetic fields play an important role in shaping the DR21 main filament and subfilaments.
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| 15. |
- Guo, Shize, et al.
(författare)
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Security-Aware Task Mapping Reducing Thermal Side Channel Leakage in CMPs
- 2019
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Ingår i: IEEE Transactions on Industrial Informatics. - : IEEE. - 1551-3203 .- 1941-0050. ; 15:10, s. 5435-5443
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Tidskriftsartikel (refereegranskat)abstract
- Chip multiprocessor (CMP) suffers from growing threats on hardware security in recent years, such as side channel attack, hardware Trojan infection, chip clone, etc. In this paper, we propose a security-aware (SA) task mapping method to reduce the information leakage from CMP thermal side channel. First, we construct a mathematical function that can estimate the CMP security cost corresponding to a given mapping result. Then, we develop a greedy mapping algorithm that automatically allocates all threads of an application to a set of proper cores, such that the total security cost is optimized. Finally, we perform extensive experiments to evaluate our method. The experimental results show that our SA mapping effectively decreases the CMP side channel leakage. Compared to the two existing task mapping methods, Linux scheduler (LS; a standard Linux scheduler) and NoC-Sprinting (NS; a thermal-aware mapping technique), our method reduces side-channel vulnerability factor by up to 19 & x0025; and 7 & x0025;, respectively. Moreover, our method also gains higher computational efficiency, with improvement in million instructions per second achieving up to 100 & x0025; against NS and up to 33 & x0025; against LS.
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| 16. |
- Hamid, Mohamed, 1983-, et al.
(författare)
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On Spectrum Sharing and Dynamic Spectrum Allocation : MAC Layer Spectrum Sensing in Cognitive Radio Networks
- 2010
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Konferensbidrag (refereegranskat)abstract
- One of the most critical issues regarding wireless networks regulation agencies is how to manage the available electromagnetic radio spectrum in a way that satisfies the needs of the huge growing in wireless systems both economically and technically, especially with the recent crowding in the available spectrum. Hence, building cognitive radio systems supporting dynamic access to the available spectrum has appeared recently as a novel solution for the wireless system huge expansion. In this paper we investigate the MAC layer sensing schemes in cognitive radio networks, where both reactive and proactive sensing are considered. In proactive sensing the adapted and non-adapted sensing periods schemes are also assessed. The assessment of these sensing schemes has been held via two performance metrics: available spectrum utilization and idle channel search delay. Simulation results show that with proactive sensing adapted periods we achieve the best performance but with an observable overhead computational tasks to be done by the network nodes.
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| 17. |
- He, Qinglong, et al.
(författare)
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Additive manufacturing of dense zirconia ceramics by fused deposition modeling via screw extrusion
- 2021
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Ingår i: Journal of the European Ceramic Society. - : Elsevier BV. - 0955-2219 .- 1873-619X. ; 41:1, s. 1033-1040
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Tidskriftsartikel (refereegranskat)abstract
- A fused deposition modeling(FDM)system via screw extrusion suitable for feeding granular feedstocks with high solid loading was developed. Key parameters included aspect ratio of the screw, the compression ratio and pitch etc. In order to get constant extruded mass flow and wire diameter a processing window was determined by optimizing the barrel temperature, the nozzle diameter and the screwing speed. Microstructural characterization coupled with flexural strength measurement revealed that a higher printing temperature was beneficial to the inter layer bonding. The sintered zirconia ceramic samples with 99% of theoretical density of the 3 mol% yttria stabilized tetragonal zirconia polycrystal (3Y-TZP) and flexural strength of 890 +/- 60 MPa was obtained. A set of zirconia ceramic parts with complex geometries and controllable dimensional accuracy was also successfully prepared for demonstrating the potential of the technique.
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| 18. |
- Hu, Li-Xin, et al.
(författare)
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What is in Nigerian waters? Target and non-target screening analysis for organic chemicals
- 2021
-
Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 284
-
Tidskriftsartikel (refereegranskat)abstract
- Emerging organic contaminants (e.g., active pharmaceutical ingredients and personal care products ingredients) are ubiquitous in the environment and potentially harmful to ecosystems, have gained increasing public attention worldwide. Nevertheless, there is a scarcity of data on these contaminants in Africa. In this study, various types of water samples (wastewater, surface water and tap water) collected from Lagos, Nigeria were analyzed for these chemicals by both target and non-target analysis on an UHPLC-Orbitrap-MS/MS. In total, 109 compounds were identified by non-target screening using the online database mzCloud. Level 1 identification confidence was achieved for 13 compounds for which reference standards were available and level 2 was achieved for the rest. In the quantitative analysis, 18 of 38 target compounds were detected, including the parent compounds and their metabolites. Acetaminophen, sulfamethoxazole, acesulfame, and caffeine were detected in all samples with their highest concentrations at 8000, 5300, 16, and 7700 μg/L in wastewater, 140000, 3300, 7.7, and 12000 μg/L in surface water, and 66, 62, 0.17 and 1000 μg/L in tap water, respectively. The occurrence of psychoactive substances, anticancer treatments, antiretrovirals, antihypertensives, antidiabetics and their metabolites were reported in Nigeria for the first time. These results indicate poor wastewater treatment and management in Nigeria, and provide a preliminary profile of organic contaminants occurring in Nigerian waters. The findings from this study urge more future research on chemical pollution in the aquatic environments in Nigeria.
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| 19. |
- Huang, Lam O., et al.
(författare)
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Genome-wide discovery of genetic loci that uncouple excess adiposity from its comorbidities
- 2021
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Ingår i: Nature Metabolism. - : Springer Nature. - 2522-5812. ; 3:2, s. 228-243
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Tidskriftsartikel (refereegranskat)abstract
- Obesity is a major risk factor for cardiometabolic diseases. Nevertheless, a substantial proportion of individuals with obesity do not suffer cardiometabolic comorbidities. The mechanisms that uncouple adiposity from its cardiometabolic complications are not fully understood. Here, we identify 62 loci of which the same allele is significantly associated with both higher adiposity and lower cardiometabolic risk. Functional analyses show that the 62 loci are enriched for genes expressed in adipose tissue, and for regulatory variants that influence nearby genes that affect adipocyte differentiation. Genes prioritized in each locus support a key role of fat distribution (FAM13A, IRS1 and PPARG) and adipocyte function (ALDH2, CCDC92, DNAH10, ESR1, FAM13A, MTOR, PIK3R1 and VEGFB). Several additional mechanisms are involved as well, such as insulin-glucose signalling (ADCY5, ARAP1, CREBBP, FAM13A, MTOR, PEPD, RAC1 and SH2B3), energy expenditure and fatty acid oxidation (IGF2BP2), browning of white adipose tissue (CSK, VEGFA, VEGFB and SLC22A3) and inflammation (SH2B3, DAGLB and ADCY9). Some of these genes may represent therapeutic targets to reduce cardiometabolic risk linked to excess adiposity.
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| 20. |
- Hult, Tommy, et al.
(författare)
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Performance of a multiple HAP system employing multiple polarization
- 2010
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Ingår i: Wireless Personal Communications. - : Springer. - 0929-6212 .- 1572-834X. ; , s. 105-117
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Konferensbidrag (refereegranskat)abstract
- In this paper we address the potential gain of using compact MIMO antenna array configurations in conjunction with HAP (High Altitude Platforms) diversity techniques in order to increase the data rates in HAP communication systems. We will also investigate the effects of spatial correlation and mutual coupling between the separate antenna elements on system performance. Simulation results show that although the capacity is degraded by correlation and mutual coupling, we still achieve significant capacity gain compared to the single HAP case. In addition, we evaluate the performance of the system for different separation angles between HAPs, and determine the optimal separation angle that maximizes the total capacity of the system. © 2008 Springer Science+Business Media, LLC.
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| 21. |
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| 22. |
- Jang, Seon-Kyeong, et al.
(författare)
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Rare genetic variants explain missing heritability in smoking.
- 2022
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Ingår i: Nature human behaviour. - : Springer Science and Business Media LLC. - 2397-3374. ; 6:11, s. 1577-1586
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Tidskriftsartikel (refereegranskat)abstract
- Common genetic variants explain less variation in complex phenotypes than inferred from family-based studies, and there is a debate on the source of this 'missing heritability'. We investigated the contribution of rare genetic variants to tobacco use with whole-genome sequences from up to 26,257 unrelated individuals of European ancestries and 11,743 individuals of African ancestries. Across four smoking traits, single-nucleotide-polymorphism-based heritability ([Formula: see text]) was estimated from 0.13 to 0.28 (s.e., 0.10-0.13) in European ancestries, with 35-74% of it attributable to rare variants with minor allele frequencies between 0.01% and 1%. These heritability estimates are 1.5-4 times higher than past estimates based on common variants alone and accounted for 60% to 100% of our pedigree-based estimates of narrow-sense heritability ([Formula: see text], 0.18-0.34). In the African ancestry samples, [Formula: see text] was estimated from 0.03 to 0.33 (s.e., 0.09-0.14) across the four smoking traits. These results suggest that rare variants are important contributors to the heritability of smoking.
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| 23. |
- Jin, Yang, et al.
(författare)
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In a cell-type specific manner, high-affinity GABA-A receptors participate in autocrine and paracrine GABA signaling in human pancreatic islets
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- γ-Aminobutyric acid (GABA), best known as the classical inhibitory neurotransmitter, is also produced and released by pancreatic islet cells. The hormone secreting α, β and δ- cells in human islets express GABA-A receptors that are activated by GABA. GABA signaling in the islets is thought to regulate hormone secretion but how it comes about is unclear. To-date the interstitial GABA concentration and cell-type specific GABA-A receptors have not been characterized. As a consequence, it is not clear how the interstitial GABA in the intact human islet regulates the specific cell-types. We have set- up single-cell RT-PCR combined whole-cell patch-clamp to investigate the functional role of GABA-A receptors in identified cell within intact human islets. GABA-activated tonic current is present in all α, β and δ-cells whereas only the δ-cells respond to GABA with large, transient currents. High-affinity GABA-A receptors activated with interstitial concentrations lower than 10 nM GABA are expressed in both α and β-cells. In the β- cells different subtypes of GABA-A receptors were identified based on single-channel kinetics, current-voltage relation and pharmacology. The data provides insight into the mechanisms underlying GABA regulation of different cell-types in intact human islet.
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| 24. |
- Jin, Yang, et al.
(författare)
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In Intact Islets Interstitial GABA Activates GABA(A) Receptors That Generate Tonic Currents in alpha-Cells
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:6, s. e67228-
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Tidskriftsartikel (refereegranskat)abstract
- In the rat islets γ-aminobutyric acid (GABA) is produced by the β-cells and, at least, the α-cells express the GABAA receptors (GABAA channels). In this study, we examined in intact islets if the interstitial GABA activated the GABAA receptors. We used the patch-clamp technique to record whole-cell and single-channel currents and single-cell RT-PCR to identify the cell-type we recorded from, in the intact rat islets. We further identified which GABAA receptor subunits were expressed. We determined the cell-type of 43 cells we recorded from and of these 49%, 28% and 7% were α, β and δ-cells, respectively. In the remaining 16% of the cells, mRNA transcripts of more than one hormone gene were detected. The results show that in rat islets interstitial GABA activates tonic current in the α-cells but not in the β-cells. Seventeen different GABAA receptor subunits are expressed with high expression of α1, α2, α4, α6, β3, γ1, δ, ρ1, ρ2 and ρ3 subunits whereas no expression was detected for α5 or ε subunits. The abundance of the GABAA receptor subunits detected suggests that a number of GABAA receptor subtypes are formed in the islets. The single-channel and tonic currents were enhanced by pentobarbital and inhibited by the GABAA receptor antagonist SR-95531. The single-channel conductance ranged from 24 to 105 pS. Whether the single-channel conductance is related to subtypes of the GABAA receptor or variable interstitial GABA concentrations remains to be determined. Our results reveal that GABA is an extracellular signaling molecule in rat pancreatic islets and reaches concentration levels that activate GABAA receptors on the glucagon-releasing α-cells.
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| 25. |
- Jin, Zhe, et al.
(författare)
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GABA-activated single-channel and tonic currents in rat brain slices
- 2011
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Ingår i: Journal of Visualized Experiments. - : MyJove Corporation. - 1940-087X. ; :53
-
Tidskriftsartikel (refereegranskat)abstract
- The GABA(A) channels are present in all neurons and are located both at synapses and outside of synapses where they generate phasic and tonic currents, respectively. The GABA(A) channel is a pentameric GABA-gated chloride channel. The channel subunits are grouped into 8 families (α1-6, β1-3, γ1-3, δ, ε, θ, π and ρ). Two alphas, two betas and one 3(rd) subunit form the functional channel. By combining studies of sub-type specific GABA-activated single-channel molecules with studies including all populations of GABA(A) channels in the neuron it becomes possible to understand the basic mechanism of neuronal inhibition and how it is modulated by pharmacological agents. We use the patch-clamp technique to study the functional properties of the GABA(A) channels in alive neurons in hippocampal brain slices and record the single-channel and whole-cell currents. We further examine how the channels are affected by different GABA concentrations, other drugs and intra and extracellular factors. For detailed theoretical and practical description of the patch-clamp method please see The Single-Channel Recordings edited by B Sakman and E Neher.
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| 26. |
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| 27. |
- Jin, Zhe, et al.
(författare)
-
Insulin reduces neuronal excitability by turning on GABA(A) channels that generate tonic current
- 2011
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:1, s. e16188-
-
Tidskriftsartikel (refereegranskat)abstract
- Insulin signaling to the brain is important not only for metabolic homeostasis but also for higher brain functions such as cognition. GABA (γ-aminobutyric acid) decreases neuronal excitability by activating GABA(A) channels that generate phasic and tonic currents. The level of tonic inhibition in neurons varies. In the hippocampus, interneurons and dentate gyrus granule cells normally have significant tonic currents under basal conditions in contrast to the CA1 pyramidal neurons where it is minimal. Here we show in acute rat hippocampal slices that insulin (1 nM) "turns on" new extrasynaptic GABA(A) channels in CA1 pyramidal neurons resulting in decreased frequency of action potential firing. The channels are activated by more than million times lower GABA concentrations than synaptic channels, generate tonic currents and show outward rectification. The single-channel current amplitude is related to the GABA concentration resulting in a single-channel GABA affinity (EC(50)) in intact CA1 neurons of 17 pM with the maximal current amplitude reached with 1 nM GABA. They are inhibited by GABA(A) antagonists but have novel pharmacology as the benzodiazepine flumazenil and zolpidem are inverse agonists. The results show that tonic rather than synaptic conductances regulate basal neuronal excitability when significant tonic conductance is expressed and demonstrate an unexpected hormonal control of the inhibitory channel subtypes and excitability of hippocampal neurons. The insulin-induced new channels provide a specific target for rescuing cognition in health and disease.
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| 28. |
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| 29. |
- Karoly, Janik, et al.
(författare)
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The JCMT BISTRO Survey: Studying the Complex Magnetic Field of L43
- 2023
-
Ingår i: Astrophysical Journal. - 1538-4357 .- 0004-637X. ; 952:1
-
Tidskriftsartikel (refereegranskat)abstract
- We present observations of polarized dust emission at 850 mu m from the L43 molecular cloud, which sits in the Ophiuchus cloud complex. The data were taken using SCUBA-2/POL-2 on the James Clerk Maxwell Telescope as a part of the BISTRO large program. L43 is a dense (N-H2 similar to 10(22) - 10(23) cm(-2)) complex molecular cloud with a submillimeter-bright starless core and two protostellar sources. There appears to be an evolutionary gradient along the isolated filament that L43 is embedded within, with the most evolved source closest to the Sco OB2 association. One of the protostars drives a CO outflow that has created a cavity to the southeast. We see a magnetic field that appears to be aligned with the cavity walls of the outflow, suggesting interaction with the outflow. We also find a magnetic field strength of up to similar to 160 +/- 30 mu G in the main starless core and up to similar to 90 +/- 40 mu G in the more diffuse, extended region. These field strengths give magnetically super- and subcritical values, respectively, and both are found to be roughly trans-Alfvenic. We also present a new method of data reduction for these denser but fainter objects like starless cores.
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| 30. |
- Korol, Sergiy V, et al.
(författare)
-
Functional Characterization of Native, High-Affinity GABAA Receptors in Human Pancreatic β Cells
- 2018
-
Ingår i: EBioMedicine. - : Elsevier BV. - 2352-3964. ; 30
-
Tidskriftsartikel (refereegranskat)abstract
- In human pancreatic islets, the neurotransmitter γ-aminobutyric acid (GABA) is an extracellular signaling molecule synthesized by and released from the insulin-secreting β cells. The effective, physiological GABA concentration range within human islets is unknown. Here we use native GABAA receptors in human islet β cells as biological sensors and reveal that 100-1000nM GABA elicit the maximal opening frequency of the single-channels. In saturating GABA, the channels desensitized and stopped working. GABA modulated insulin exocytosis and glucose-stimulated insulin secretion. GABAA receptor currents were enhanced by the benzodiazepine diazepam, the anesthetic propofol and the incretin glucagon-like peptide-1 (GLP-1) but not affected by the hypnotic zolpidem. In type 2 diabetes (T2D) islets, single-channel analysis revealed higher GABA affinity of the receptors. The findings reveal unique GABAA receptors signaling in human islets β cells that is GABA concentration-dependent, differentially regulated by drugs, modulates insulin secretion and is altered in T2D.
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| 31. |
- Liao, Wenlong, et al.
(författare)
-
An Open-Source Toolbox with Classical Classifiers for Electricity Theft Detection
- 2021
-
Ingår i: 2021 IEEE 2nd China International Youth Conference on Electrical Engineering, CIYCEE 2021. - : Institute of Electrical and Electronics Engineers Inc..
-
Konferensbidrag (refereegranskat)abstract
- Recently, there is increasing interest in detecting electricity thieves for economic benefits for power companies, and many works aim to improve the accuracy of electricity theft detection. Nevertheless, a core obstacle that currently hinders the direct comparison of classifiers for electricity theft detection is the lack of a standard and public dataset, since fraudulent power load profiles are usually difficult to collect for various reasons, including cost, cumber, and confidentiality. Therefore, this paper presents an open-source toolbox, which generates different kinds of fraudulent power load profiles from attack models, and integrates classical classifiers (e.g., support vector machine, multi-layer perceptron, convolutional neural network, long short-term memory, bidirectional long short-term memory) with different performance as baselines for the comparison with new algorithms. Users can easily generate datasets and modify parameters of classical classifiers guided by user friendly interactive interfaces. The codes, toolbox, and user manuals are available online and it is free to use and extend them.
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| 32. |
- Liao, Wenlong, et al.
(författare)
-
Scenario Generation for Cooling, Heating, and Power Loads Using Generative Moment Matching Networks
- 2022
-
Ingår i: CSEE JOURNAL OF POWER AND ENERGY SYSTEMS. - : Power System Technology Press. - 2096-0042. ; 8:6, s. 1730-1740
-
Tidskriftsartikel (refereegranskat)abstract
- Scenario generations of cooling, heating, and power loads are of great significance for the economic operation and stability analysis of integrated energy systems. In this paper, a novel deep generative network is proposed to model cooling, heating, and power load curves based on generative moment matching networks (GMMNs) where an auto-encoder transforms high-dimensional load curves into low-dimensional latent variables and the maximum mean discrepancy represents the similarity metrics between the generated samples and the real samples. After training the model, the new scenarios are generated by feeding Gaussian noises to the scenario generator of the GMMN. Unlike the explicit density models, the proposed GMMN does not need to artificially assume the probability distribution of the load curves, which leads to stronger universality. The simulation results show that the GMMN not only fits the probability distribution of multi-class load curves very well, but also accurately captures the shape (e.g., large peaks, fast ramps, and fluctuation), frequency-domain characteristics, and temporal-spatial correlations of cooling, heating, and power loads. Furthermore, the energy consumption of generated samples closely resembles that of real samples.
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| 33. |
- Liao, Wenlong, et al.
(författare)
-
Scenario Generations for Renewable Energy Sources and Loads Based on Implicit Maximum Likelihood Estimations
- 2022
-
Ingår i: Journal of Modern Power Systems and Clean Energy. - : Journal of Modern Power Systems and Clean Energy. - 2196-5625 .- 2196-5420. ; 10:6, s. 1563-1575
-
Tidskriftsartikel (refereegranskat)abstract
- Scenario generations for renewable energy sources and loads play an important role in the stable operation and risk assessment of integrated energy systems. This paper proposes a deep generative network based method to model time-series curves, e.g., power generation curves and load curves, of renewable energy sources and loads based on implicit maximum likelihood estimations (IMLEs), which can generate realistic scenarios with similar patterns as real ones. After training the model, any number of new scenarios can be obtained by simply inputting Gaussian noises into the data generator of IMLEs. The proposed approach does not require any model assumptions or prior knowledge of the form in the likelihood function being made during the training process, which leads to stronger applicability than explicit density model based methods. The extensive experiments show that the IMLEs accurately capture the complex shapes, frequency-domain characteristics, probability distributions, and correlations of renewable energy sources and loads. Moreover, the proposed approach can be easily generalized to scenario generation tasks of various renewable energy sources and loads by fine-tuning parameters and structures.
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| 34. |
- Liu, Zhe, et al.
(författare)
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Characterizations of bacterial cellulose nanofibers reinforced edible films based on konjac glucomannan
- 2019
-
Ingår i: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 145, s. 634-645
-
Tidskriftsartikel (refereegranskat)abstract
- This study was aimed at developing edible films of konjac glucomannan (KGM) with different contents of bacterial cellulose nanofibers (BCNs). The effects of different contents of BCNs (0-4% (w/w)) on the properties of KGM-based edible films were investigated in the present work. The rheological properties showed that the film-forming solutions displayed an entanglement system with G'G″ at high frequencies. SEM indicated that BCNs were well dispersed in the BCNs/KGM films. With the increase of BCNs contents, the surface morphology of the films assessed by AFM displayed an increased trend in the surface roughness. Moreover, the films were formed mainly through hydrogen bonds as indicated by FTIR analysis. XRD, DSC and TGA showed that the crystallinity and the thermal stability of films increased with the increase of BCNs. Meanwhile, barrier properties of films were improved by the addition of BCNs. Additionally, with the increase of BCNs, the tensile strength (TS) of the films increased, while the elongation at break (EAB) was increased and then decreased. Therefore, reinforcement of KGM-based films with BCNs leads to enhance barrier and mechanical properties with promising potential as packaging films for food products.
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| 35. |
- Lu, Yuan-Yuan, et al.
(författare)
-
A clinical study of microcirculatory disturbance in Chinese patients with sudden deafness
- 2008
-
Ingår i: Acta Oto-Laryngologica. - : Informa UK Limited. - 0001-6489 .- 1651-2251. ; 128:11
-
Tidskriftsartikel (refereegranskat)abstract
- Conclusion. Cochlear microcirculation disturbance is closely associated with sudden deafness. Objectives. To investigate the relationship between cochlear microcirculation and sudden deafness. Subjects and methods. Clinical laboratory parameters (clinical chemistry, hemorheology, hematology, and hemostasis determinations) were studied in 86 patients with sudden deafness and 30 healthy control subjects. Results. The levels of total cholesterol (TCH), triglyceride (TG), and lipoprotein A were significantly higher in patients with sudden deafness than in control subjects. Plasma viscosity, ratio viscosity of whole blood, reduced viscosity of whole blood, high and low shear relative viscosity of whole blood, index of red blood cells transmutation, and fibrinogen level in the plasma of patients with sudden sensorineural hearing loss (SSNHL) were also significantly elevated in comparison with those in control subjects. White-collar workers with psychological and behavioral abnormalities tend to suffer from sudden deafness.
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| 36. |
- Luo, Yang, et al.
(författare)
-
Three-dimensional and temperature-dependent electronic structure of the heavy-fermion compound CePt2In7 studied by angle-resolved photoemission spectroscopy
- 2020
-
Ingår i: Physical Review B. - : AMER PHYSICAL SOC. - 2469-9950 .- 2469-9969. ; 101:11
-
Tidskriftsartikel (refereegranskat)abstract
- The three-dimensional and temperature-dependent electronic structures of the heavy-fermion superconductor CePt2In7 are investigated. Angle-resolved photoemission spectroscopy using variable photon energy establishes the existence of quasi-two- and three-dimensional Fermi surface topologies. Temperature-dependent 4d-4f on-resonance photoemission spectroscopies data reveal that heavy quasiparticle bands begin to form at a temperature well above the characteristic (coherence) temperature T+. The emergence of low-lying crystal electric field excitation may be responsible for the "relocalization" or the precursor to the establishment of heavy electrons coherence in heavy-fermion compounds. These findings provide critical insight into understanding the hybridization in heavy-fermion systems.
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| 37. |
- Mohammed, Abbas, et al.
(författare)
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Next Generation Broadband Services from High Altitude Platforms
- 2010
-
Ingår i: Fourth-Generation Wireless Networks. - : IGI Global. - 9781615206742
-
Bokkapitel (refereegranskat)abstract
- In this chapter the authors investigate the possibility and performance of delivering broadband services from High Altitude Platforms (HAPs). In particular, the performance and coexistence techniques of providing worldwide interoperability for microwave access (WiMAX) from HAPs and terrestrial systems in the shard frequency band are investigated. The WiMAX standard is based on orthogonal frequency-division multiplexing (OFDM) and multiple-input and multiple-output (MIMO) technologies and has been regarded as one of the most promising 4G standards to lead 4G market and deliver broadband services globally. The authors show that it is possible to provide WiMAX services from an individual HAP system. The coexistence capability with the terrestrial WiMAX system is also examined. The simulation results show that it is effective to deliver WiMAX via HAPs and share the spectrum with terrestrial systems.
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| 38. |
- Osman, Ammar, et al.
(författare)
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Multipath Wave Propagation Effects on the Performance of OFDM UMTS-LTE Communication System
- 2008
-
Konferensbidrag (refereegranskat)abstract
- The proposed Long Term Evolution (LTE), for UMTS network, study by the Third Generation Partnership Project (3GPP) towards forth generation mobile telecommunication systems was one of the significant trends toward meeting the requirements and services of these future systems. This paper analyzes the requirements for this evolution and evaluates the performance of the Orthogonal Frequency Division Multiplexing (OFDM) UMTS-LTE system under different propagation impairments (AWGN, Pedestrian and Vehicular multipath fading channels of different speeds) in terms of bit and symbol error rates (BER and SER) for different modulation formats.
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| 39. |
- Park, Gina J., et al.
(författare)
-
The mechanism of RNA capping by SARS-CoV-2
- 2022
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 609:7928, s. 793-800
-
Tidskriftsartikel (refereegranskat)abstract
- The RNA genome of SARS-CoV-2 contains a 5′ cap that facilitates the translation of viral proteins, protection from exonucleases and evasion of the host immune response1–4. How this cap is made in SARS-CoV-2 is not completely understood. Here we reconstitute the N7- and 2′-O-methylated SARS-CoV-2 RNA cap (7MeGpppA2′-O-Me) using virally encoded non-structural proteins (nsps). We show that the kinase-like nidovirus RdRp-associated nucleotidyltransferase (NiRAN) domain5 of nsp12 transfers the RNA to the amino terminus of nsp9, forming a covalent RNA–protein intermediate (a process termed RNAylation). Subsequently, the NiRAN domain transfers the RNA to GDP, forming the core cap structure GpppA-RNA. The nsp146 and nsp167 methyltransferases then add methyl groups to form functional cap structures. Structural analyses of the replication–transcription complex bound to nsp9 identified key interactions that mediate the capping reaction. Furthermore, we demonstrate in a reverse genetics system8 that the N terminus of nsp9 and the kinase-like active-site residues in the NiRAN domain are required for successful SARS-CoV-2 replication. Collectively, our results reveal an unconventional mechanism by which SARS-CoV-2 caps its RNA genome, thus exposing a new target in the development of antivirals to treat COVID-19.
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| 40. |
- Pecunia, Vincenzo, et al.
(författare)
-
Roadmap on energy harvesting materials
- 2023
-
Ingår i: Journal of Physics. - : IOP Publishing. - 2515-7639. ; 6:4
-
Tidskriftsartikel (refereegranskat)abstract
- Ambient energy harvesting has great potential to contribute to sustainable development and address growing environmental challenges. Converting waste energy from energy-intensive processes and systems (e.g. combustion engines and furnaces) is crucial to reducing their environmental impact and achieving net-zero emissions. Compact energy harvesters will also be key to powering the exponentially growing smart devices ecosystem that is part of the Internet of Things, thus enabling futuristic applications that can improve our quality of life (e.g. smart homes, smart cities, smart manufacturing, and smart healthcare). To achieve these goals, innovative materials are needed to efficiently convert ambient energy into electricity through various physical mechanisms, such as the photovoltaic effect, thermoelectricity, piezoelectricity, triboelectricity, and radiofrequency wireless power transfer. By bringing together the perspectives of experts in various types of energy harvesting materials, this Roadmap provides extensive insights into recent advances and present challenges in the field. Additionally, the Roadmap analyses the key performance metrics of these technologies in relation to their ultimate energy conversion limits. Building on these insights, the Roadmap outlines promising directions for future research to fully harness the potential of energy harvesting materials for green energy anytime, anywhere.
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| 41. |
- Pedersen, Torbjorn O., et al.
(författare)
-
Endothelial microvascular networks affect gene-expression profiles and osteogenic potential of tissue-engineered constructs
- 2013
-
Ingår i: STEM CELL RES THER. - : Springer Science and Business Media LLC. - 1757-6512. ; 4, s. 52-
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: A major determinant of the potential size of cell/scaffold constructs in tissue engineering is vascularization. The aims of this study were twofold: first to determine the in vitro angiogenic and osteogenic geneexpression profiles of endothelial cells (ECs) and mesenchymal stem cells (MSCs) cocultured in a dynamic 3D environment; and second, to assess differentiation and the potential for osteogenesis after in vivo implantation. Methods: MSCs and ECs were grown in dynamic culture in poly(L-lactide-co-1,5-dioxepan-2-one) (poly(LLA-co-DXO)) copolymer scaffolds for 1 week, to generate three-dimensional endothelial microvascular networks. The constructs were then implanted in vivo, in a murine model for ectopic bone formation. Expression of selected genes for angiogenesis and osteogenesis was studied after a 1-week culture in vitro. Human cell proliferation was assessed as expression of ki67, whereas a-smooth muscle actin was used to determine the perivascular differentiation of MSCs. Osteogenesis was evaluated in vivo through detection of selected markers, by using real-time RT-PCR, alkaline phosphatase (ALP), Alizarin Red, hematoxylin/eosin (HE), and Masson trichrome staining. Results: The results show that endothelial microvascular networks could be generated in a poly(LLA-co-DXO) scaffold in vitro and sustained after in vivo implantation. The addition of ECs to MSCs influenced both angiogenic and osteogenic gene-expression profiles. Furthermore, human ki67 was upregulated before and after implantation. MSCs could support functional blood vessels as perivascular cells independent of implanted ECs. In addition, the expression of ALP was upregulated in the presence of endothelial microvascular networks. Conclusions: This study demonstrates that copolymer poly(LLA-co-DXO) scaffolds can be prevascularized with ECs and MSCs. Although a local osteoinductive environment is required to achieve ectopic bone formation, seeding of MSCs with or without ECs increases the osteogenic potential of tissue-engineered constructs.
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| 42. |
- Pedersen, Torbjorn O., et al.
(författare)
-
Mesenchymal stem cells induce endothelial cell quiescence and promote capillary formation
- 2014
-
Ingår i: Stem Cell Research & Therapy. - : Springer Science and Business Media LLC. - 1757-6512. ; 5, s. 23-
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: Rapid establishment of functional blood vessels is a prerequisite for successful tissue engineering. During vascular development, endothelial cells (ECs) and perivascular cells assemble into a complex regulating proliferation of ECs, vessel diameter and production of extracellular matrix proteins. The aim of this study was to evaluate the ability of mesenchymal stem cells (MSCs) to establish an endothelial-perivascular complex in tissue-engineered constructs comprising ECs and MSCs. Methods: Primary human ECs and MSCs were seeded onto poly(L-lactide-co-1,5-dioxepan-2-one) (poly(LLA-co-DXO)) scaffolds and grown in dynamic culture before subcutaneous implantation in immunocompromised mice for 1 and 3 weeks. Cellular activity, angiogenic stimulation and vascular assembly in cell/scaffold constructs seeded with ECs or ECs/MSCs in a 5:1 ratio was monitored with real-time RT-PCR, ELISA and immunohistochemical microscopy analysis. Results: A quiescent phenotype of ECs was generated, by adding MSCs to the culture system. Decreased proliferation of ECs, in addition to up-regulation of selected markers for vascular maturation was demonstrated. Baseline expression of VEGFa was higher for MSCs compared with EC (P < 0.001), with subsequent up-regulated VEGFa-expression for EC/MSC constructs before (P < 0.05) and after implantation (P < 0.01). Furthermore, an inflammatory response with CD11b + cells was generated from implantation of human cells. At the end of the 3 week experimental period, a higher vascular density was shown for both cellular constructs compared with empty control scaffolds (P < 0.01), with the highest density of capillaries being generated in constructs comprising both ECs and MSCs. Conclusions: Induction of a quiescent phenotype of ECs associated with vascular maturation can be achieved by co-seeding with MSCs. Hence, MSCs can be appropriate perivascular cells for tissue-engineered constructs.
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| 43. |
- Qian, Cheng, et al.
(författare)
-
A cloud service platform integrating additive and subtractive manufacturing with high resource efficiency
- 2019
-
Ingår i: Journal of Cleaner Production. - : ELSEVIER SCI LTD. - 0959-6526 .- 1879-1786. ; 241
-
Tidskriftsartikel (refereegranskat)abstract
- Cloud manufacturing has been studied for years, yet commercial implementations are still limited. The recent advances in information technology have stimulated the free sharing of additive and subtractive manufacturing (A/SM) resources through cloud services. Currently, due to the lack of a general method to model manufacturing capabilities, as well as the absence of an open platform to integrate business and manufacturing processes, it is difficult to integrate A/SM resources within one platform efficiently and seamlessly. In this research, a service encapsulation model for A/SM resources was described using ontology modeling technique. A collaborative cloud platform integrating A/SM was designed that can provide optimal production plans considering time, cost, quality, and energy waste during manufacturing. The proposed platform and models were demonstrated by a prototype system and tested in a case study, which showed the integrated platform can increase the utilization rate of resources while reducing energy consumption. This research has provided a practical tool for virtualization, integration, and configuration of A/SM resource with high efficiency. (C) 2019 Elsevier Ltd. All rights reserved.
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| 44. |
- Qian, Junpeng, et al.
(författare)
-
Vision-Based Contactless Pose Estimation for Human Thermal Discomfort
- 2020
-
Ingår i: Atmosphere. - : MDPI. - 2073-4433. ; 11:4
-
Tidskriftsartikel (refereegranskat)abstract
- Real-time and effective human thermal discomfort detection plays a critical role in achieving energy efficient control of human centered intelligent buildings because estimation results can provide effective feedback signals to heating, ventilation and air conditioning (HVAC) systems. How to detect occupant thermal discomfort is a challenge. Unfortunately, contact or semi-contact perception methods are inconvenient in practical application. From the contactless perspective, a kind of vision-based contactless human discomfort pose estimation method was proposed in this paper. Firstly, human pose data were captured from a vision-based sensor, and corresponding human skeleton information was extracted. Five thermal discomfort-related human poses were analyzed, and corresponding algorithms were constructed. To verify the effectiveness of the algorithms, 16 subjects were invited for physiological experiments. The validation results show that the proposed algorithms can recognize the five human poses of thermal discomfort.
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| 45. |
- Ren, Wen, et al.
(författare)
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The workflows of a novel self-glazed zirconia for dental prostheses fabrication : case reports
- 2018
-
Ingår i: Advances in Applied Ceramics. - : Informa UK Limited. - 1743-6753 .- 1743-6761. ; 117:7, s. 406-413
-
Tidskriftsartikel (refereegranskat)abstract
- In the clinical application of ceramic prostheses, micro-leakage, porcelain chipping, low-treatment efficiency and quality uncertainty have appeared as the major problems that dentists encountered. However, the full-contour zirconia monolithic prostheses have the potentials for solving the problems. It appears that the full-contour zirconia monolithic prostheses produced through the fully digital workflow can ensure that the restorations can be closely aligned with the abutment and be easy to adjust and to wear, thus to assure the stability and accuracy of occlusal, which are crucial to the ultimate integration of the full-contour zirconia monolithic prostheses by avoiding unfavourable grinding. The newly developed full digital approach can greatly simplify the previous workflow that involved many manual operations. It improves not only the treatment efficiency but also the reliability of the prostheses by avoiding manual operational mistakes.
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| 46. |
- Seun, Ajayi Taiwo, et al.
(författare)
-
Channel Modelling and Characterization for Mobile Satellite Communication Systems
- 2009
-
Konferensbidrag (refereegranskat)abstract
- Reliable characterization of the propagation environment and channel modelling of mobile satellite communication systems is necessary in order to provide better quality of service and efficient design of these systems. In this paper, the channel impairments affecting the performance and an overview of the satellite channel models are presented. The statistical distributions of the received signal that can be used to characterize the dynamic nature of these propagation channels are also presented. The main modelling parameters are investigated and simulation results show that the bit error rate performance (BER) is predominantly affected by the shadowing factor.
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| 47. |
- Suliman, Salwa, et al.
(författare)
-
Release and bioactivity of bone morphogenetic protein-2 are affected by scaffold binding techniques in vitro and in vivo
- 2015
-
Ingår i: Journal of Controlled Release. - : Elsevier BV. - 0168-3659 .- 1873-4995. ; 197, s. 148-157
-
Tidskriftsartikel (refereegranskat)abstract
- A low dose of 1 mu g rhBMP-2 was immobilised by four different functionalising techniques on recently developed poly(L-lactide)-co-(epsilon-caprolactone) [(poly(LLA-co-CL)] scaffolds. It was either (i) physisorbed on unmodified scaffolds [PHY], (ii) physisorbed onto scaffolds modified with nanodiamond particles [nDP-PHY], (iii) covalently linked onto nDPs that were used to modify the scaffolds [nDP-COV] or (iv) encapsulated in microspheres distributed on the scaffolds [MICS]. Release kinetics of BMP-2 from the different scaffolds was quantified using targeted mass spectrometry for up to 70 days. PHY scaffolds had an initial burst of release while MICS showed a gradual and sustained increase in release. In contrast, NDP-PHY and nDP-COV scaffolds showed no significant release, although nDP-PHY scaffolds maintained bioactivity of BMP-2. Human mesenchymal stem cells cultured in vitro showed upregulated BMP-2 and osteocalcin gene expression at both week 1 and week 3 in the MICS and nDP-PHY scaffold groups. These groups also demonstrated the highest BMP-2 extracellular protein levels as assessed by ELISA, and mineralization confirmed by Alizarin red. Cells grown on the PHY scaffolds in vitro expressed collagen type 1 alpha 2 early but the scaffold could not sustain rhBMP-2 release to express mineralization. After 4 weeks post-implantation using a rat mandible critical-sized defect model, micro-CT and Masson trichrome results showed accelerated bone regeneration in the PHY, nDP-PHY and MICS groups. The results demonstrate that PHY scaffolds may not be desirable for clinical use, since similar osteogenic potential was not seen under both in vitro and in vivo conditions, in contrast to nDP-PHY and MICS groups, where continuous low doses of BMP-2 induced satisfactory bone regeneration in both conditions. The nDP-PHY scaffolds used here in critical-sized bone defects for the first time appear to have promise compared to growth factors adsorbed onto a polymer alone and the short distance effect prevents adverse systemic side effects.
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| 48. |
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| 49. |
- Sun, Yang, 1983-, et al.
(författare)
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Degradable amorphous scaffolds with enhanced mechanical properties and homogeneous cell distribution produced by a three-dimensional fiber deposition method
- 2012
-
Ingår i: Journal of Biomedical Materials Research. Part A. - : Wiley. - 1549-3296 .- 1552-4965. ; 100A:10, s. 2739-2749
-
Tidskriftsartikel (refereegranskat)abstract
- The mechanical properties of amorphous, degradable, and highly porous poly(lactide-co-caprolactone) structures have been improved by using a 3D fiber deposition (3DF) method. Two designs of 3DF scaffolds, with 45 degrees and 90 degrees layer rotation, were printed and compared with scaffolds produced by a salt-leaching method. The scaffolds had a porosity range from 64% to 82% and a high interconnectivity, measured by micro-computer tomography. The 3DF scaffolds had 89 times higher compressive stiffness and 35 times higher tensile stiffness than the salt-leached scaffolds. There was a distinct decrease in the molecular weight during printing as a consequence of the high temperature. The chain microstructure was, however, not affected; the glass transition temperature and the decomposition temperature were constant. Human OsteoBlast-like cells were cultured in vitro and the cell morphology and distribution were observed by scanning electron microscopy and fluorescence microscopy. The cell distribution on the 3DF scaffolds was more homogeneous than the salt-leached scaffolds, suggesting that 3DF scaffolds are more suitable as porous biomaterials for tissue engineering. These results show that it is possible to design and optimize the properties of amorphous polymer scaffolds. The 3DF method produce amorphous degradable poly(lactide-co-caprolactone) that are strong and particularly suitable for cell proliferation.
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| 50. |
- Sun, Yang, et al.
(författare)
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Reinforced Degradable Biocomposite by Homogenously Distributed Functionalized Nanodiamond Particles
- 2015
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Ingår i: Macromolecular materials and engineering. - : Wiley. - 1438-7492 .- 1439-2054. ; 300:4, s. 436-447
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Tidskriftsartikel (refereegranskat)abstract
- Severe phase separation was observed in blending nanodiamond particle (n-DP) in poly (L-lactide-co-e-caprolactone) (poly(LLA-co-CL)) scaffold. In this study we optimized the scaffold by the addition of 1-50% (w/w) polylactide modified n-DP (n-DP-PLA) or benzoquinone-modified n-DP (n-DP-BQ). Composed by 10% n-DP-PLA, composite had 6 times higher E-modulus in tensile test, whereas the maximum reinforcement can be higher than 15 times. However, n-DP-BQ composites conserved the mechanical properties, and thermal properties of the polymer substrate. The attachment, spreading and growth of UE7T13 cells on modified n-DP composites were similar to poly(LLA-co-CL), and independent to n-DP concentrations. In summary, a proper modified n-DP is the key to reinforce poly(LLA-co-CL) for tissue engineering.
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