203 research outputs found

    Degraded planetary tracking control of an omni-directional vectored-thruster aerostat

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    The problem of horizontal-plane tracking control of an omni-directional, four vectored-thruster aerostat when subjected to actuator failure is considered. The actuator failures result in the aerostat becoming underactuated, so it can only effect surge force and pure yaw moment about the body centre. To achieve accurate position control in the horizontal plane, direct position control is used instead of heading control. This mode of controller is called degraded tracking control in contrast to full authority control of the overactuated four vectored-thruster aerostat. This degraded tracking controller uses commanded yaw rate to track lateral position, and yaw moment to eliminate lateral position error, therefore yaw angle is not directly controlled. To guarantee the stability of the yaw motion, a Virtual Reference Point (VRP) tracking strategy is proposed, where the VRP is used instead of the body center (BC) in position tracking. The VRP generates a negative compensated force in the surge direction which makes the side-force and yaw moment have the same sign and so ensure that the aerostat is in a stable tracking configuration. Meanwhile the VRP also decreases the transmission ratio of commanded yaw rate to commanded lateral velocity, making the aerostat's yaw motion vary slowly during transitional phase, so steady position tracking is obtained

    Multi-user MIMO-OFDM for indoor visible light communication systems

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    In this paper, we investigate an indoor multiuser visible light communication system employing multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM). For each subcarrier in OFDM, the corresponding precoding matrix is calculated in the frequency domain to eliminate multi-user interference. The distances of the multiple transmitter-receiver links are different, which results in various temporal delays and phase differences in the frequency domain. Phase information is firstly considered, whereby complex instead of real channel matrices are used for precoding, which reduces the channel correlation and achieves better performance. Moreover, two DC bias and scaling factor calculation schemes are proposed, and their performances are compared with zero forcing and minimum mean-squared error (MMSE) precoding techniques

    Effect of rs1344706 in the ZNF804A gene on the brain network.

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    ZNF804A rs1344706 (A/C) was the first SNP that reached genome-wide significance for schizophrenia. Recent studies have linked rs1344706 to functional connectivity among specific brain regions. However, no study thus far has examined the role of this SNP in the entire functional connectome. In this study, we used degree centrality to test the role of rs1344706 in the whole-brain voxel-wise functional connectome during the resting state. 52 schizophrenia patients and 128 healthy controls were included in the final analysis. In our whole-brain analysis, we found a significant interaction effect of genotype Ã— diagnosis at the precuneus (PCU) (cluster size = 52 voxels, peak voxel MNI coordinates: x = 9, y = - 69, z = 63, F = 32.57, FWE corrected P < 0.001). When we subdivided the degree centrality network according to anatomical distance, the whole-brain analysis also found a significant interaction effect of genotype Ã— diagnosis at the PCU with the same peak in the short-range degree centrality network (cluster size = 72 voxels, F = 37.29, FWE corrected P < 0.001). No significant result was found in the long-range degree centrality network. Our results elucidated the contribution of rs1344706 to functional connectivity within the brain network, and may have important implications for our understanding of this risk gene's role in functional dysconnectivity in schizophrenia

    PM-DCO-OFDM for PAPR reduction in visible light communications

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    Phase modulation is used in DCO-OFDM for visible light communications, whereby around 10 dB PAPR reduction is achieved. Considering the nonlinearity of LED emitters, our proposed method achieves better BER performance than that of conventional DCO-OFDM

    Interaction of a traditional Chinese Medicine (PHY906) and CPT-11 on the inflammatory process in the tumor microenvironment

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    <p>Abstract</p> <p>Background -</p> <p>Traditional Chinese Medicine (TCM) has been used for thousands of years to treat or prevent diseases, including cancer. Good manufacturing practices (GMP) and sophisticated product analysis (PhytomicsQC) to ensure consistency are now available allowing the assessment of its utility. Polychemical Medicines, like TCM, include chemicals with distinct tissue-dependent pharmacodynamic properties that result in tissue-specific bioactivity. Determining the mode of action of these mixtures was previously unsatisfactory; however, information rich RNA microarray technologies now allow for thorough mechanistic studies of the effects complex mixtures. PHY906 is a long used four herb TCM formula employed as an adjuvant to relieve the side effects associated with chemotherapy. Animal studies documented a decrease in global toxicity and an increase in therapeutic effectiveness of chemotherapy when combined with PHY906.</p> <p>Methods -</p> <p>Using a systems biology approach, we studied tumor tissue to identify reasons for the enhancement of the antitumor effect of CPT-11 (CPT-11) by PHY906 in a well-characterized pre-clinical model; the administration of PHY906 and CPT-11 to female BDF-1 mice bearing subcutaneous Colon 38 tumors.</p> <p>Results -</p> <p>We observed that 1) individually PHY906 and CPT-11 induce distinct alterations in tumor, liver and spleen; 2) PHY906 alone predominantly induces repression of transcription and immune-suppression in tumors; 3) these effects are reverted in the presence of CPT-11, with prevalent induction of pro-apoptotic and pro-inflammatory pathways that may favor tumor rejection.</p> <p>Conclusions -</p> <p>PHY906 together with CPT-11 triggers unique changes not activated by each one alone suggesting that the combination creates a unique tissue-specific response.</p

    Vitreous Olink proteomics reveals inflammatory biomarkers for diagnosis and prognosis of traumatic proliferative vitreoretinopathy

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    BackgroundThe aim of this study was to identify inflammatory biomarkers in traumatic proliferative vitreoretinopathy (TPVR) patients and further validate the expression curve of particular biomarkers in the rabbit TPVR model.MethodsThe Olink Inflammation Panel was used to compare the differentially expressed proteins (DEPs) in the vitreous of TPVR patients 7–14 days after open globe injury (OGI) (N = 19) and macular hole patients (N = 22), followed by correlation analysis between DEPs and clinical signs, protein–protein interaction (PPI) analysis, area under the receiver operating characteristic curve (AUC) analysis, and function enrichment analysis. A TPVR rabbit model was established and expression levels of candidate interleukin family members (IL-6, IL-7, and IL-33) were measured by enzyme-linked immunosorbent assay (ELISA) at 0, 1, 3, 7, 10, 14, and 28 days after OGI.ResultsForty-eight DEPs were detected between the two groups. Correlation analysis showed that CXCL5, EN-RAGE, IL-7, ADA, CD5, CCL25, CASP8, TWEAK, and IL-33 were significantly correlated with clinical signs including ocular wound characteristics, PVR scoring, PVR recurrence, and final visual acuity (R = 0.467–0.699, p &lt; 0.05), and all with optimal AUC values (0.7344–1). Correlations between DEP analysis and PPI analysis further verified that IL-6, IL-7, IL-8, IL-33, HGF, and CXCL5 were highly interactive (combined score: 0.669–0.983). These DEPs were enriched in novel pathways such as cancer signaling pathway (N = 14, p &lt; 0.000). Vitreous levels of IL-6, IL-7, and IL-33 in the rabbit TPVR model displayed consistency with the trend in Olink data, all exhibiting marked differential expression 1 day following the OGI.ConclusionIL-7, IL-33, EN-RAGE, TWEAK, CXCL5, and CD5 may be potential biomarkers for TPVR pathogenesis and prognosis, and early post-injury may be an ideal time for TPVR intervention targeting interleukin family biomarkers

    Impacts of groundwater depth on regional scale soil gleyization under changing climate in the Poyang Lake Basin, China

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    This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/ which permits use, distribution and reproduction in any medium, provided the original work is properly cited. This author accepted manuscript is made available following 24 month embargo from date of publication (November 2018) in accordance with the publisher’s archiving policyVarious natural and anthropogenic factors affect the formation of gleyed soil. It is a major challenge to identify the key hazard factors and evaluate the dynamic evolutionary process of soil gleyization at a regional scale under future climate change. This study addressed this complex challenge based on regional groundwater modelling for a typical agriculture region located in the Ganjiang River Delta (GRD) of Poyang Lake Basin, China. We first implemented in-situ soil sampling analysis and column experiments under different water depths to examine the statistical relationship between groundwater depth (GD) and gleyization indexes including active reducing substance, ferrous iron content, and redox potential. Subsequently, a three-dimensional groundwater flow numerical model for the GRD was established to evaluate the impacts of the historical average level and future climate change on vadose saturation and soil gleyization (averaged over 2016–2050) in the irrigated farmland. Three climate change scenarios associated with carbon dioxide emission (A1B, A2, and B1) were predicted by the ECHAM5 global circulation model published in IPCC Assessment Report (2007). The ECHAM5 outputs were applied to quantify the variation of groundwater level and to identify the potential maximum gleyed zones affected by the changes of meteorological and hydrological conditions. The results of this study indicate that GD is an indirect indicator for predicting the gradation of soil gleyization at the regional scale, and that the GRD will suffer considerable soil gleyization by 2050 due to fluctuations of the water table induced by future climate changes. Compared with the annually average condition, the climate scenario B1 will probably exacerbate soil gleyization with an 8.8% increase in total gleyed area in GRD. On average, the highly gleyed areas will increase in area by 29.7 km2, mainly on the riverside area, and the medium-slightly gleyed area will increase by 19.2 km2 in the middle region.This work was partially supported by the National Key R&D Program of China (No. 2016YFC0402800), the National Natural Science Foundation of China (Nos. 41772254, 41502226, and 41402198), and the Fundamental Research Funds for the Central Universities (No. 2018B18714). We are grateful to Jiangxi Institute of Survey and Design, who provides the detailed hydrogeological data of PLB for establishing three-dimensional groundwater flow model. Yun Yang gratefully acknowledges financial support from China Scholarship Council (CSC No. 201706715023) during the visit to National Centre for Groundwater Research and Training (NCGRT), Australia. Behzad Ataie-Ashtiani and Craig T. Simmons acknowledge support from the National Centre for Groundwater Research and Training, Australia

    Longitudinal Study of Recurrent Metastatic Melanoma Cell Lines Underscores the Individuality of Cancer Biology.

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    Recurrent metastatic melanoma provides a unique opportunity to analyze disease evolution in metastatic cancer. Here, we followed up eight patients with an unusually prolonged history of metastatic melanoma, who developed a total of 26 recurrences over several years. Cell lines derived from each metastasis were analyzed by comparative genomic hybridization and global transcript analysis. We observed that conserved, patient-specific characteristics remain stable in recurrent metastatic melanoma even after years and several recurrences. Differences among individual patients exceeded within-patient lesion variability, both at the DNA copy number (P<0.001) and RNA gene expression level (P<0.001). Conserved patient-specific traits included expression of several cancer/testis antigens and the c-kit proto-oncogene throughout multiple recurrences. Interestingly, subsequent recurrences of different patients did not display consistent or convergent changes toward a more aggressive disease phenotype. Finally, sequential recurrences of the same patient did not descend progressively from each other, as irreversible mutations such as homozygous deletions were frequently not inherited from previous metastases. This study suggests that the late evolution of metastatic melanoma, which markedly turns an indolent disease into a lethal phase, is prone to preserve case-specific traits over multiple recurrences and occurs through a series of random events that do not follow a consistent stepwise process.Journal of Investigative Dermatology advance online publication, 2 January 2014; doi:10.1038/jid.2013.495

    Giant polarization in super-tetragonal ferroelectric thin films through interphase strain

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    Strain engineering has emerged as a powerful tool to enhance the performance of known functional materials. Here we demonstrate a general and practical method to obtain super-tetragonality and giant polarization using interphase strain. We use this method to create an out-of-plane–to–in-plane lattice parameter ratio of 1.238 in epitaxial composite thin films of tetragonal lead titanate (PbTiO3), compared to 1.065 in bulk. These thin films with super-tetragonal structure possess a giant remanent polarization, 236.3 microcoulombs per square centimeter, which is almost twice the value of known ferroelectrics. The super-tetragonal phase is stable up to 725°C, compared to the bulk transition temperature of 490°C. The interphase-strain approach could enhance the physical properties of other functional materials.PostprintPeer reviewe
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