82 research outputs found

    Deltex E3 Ubiquitin Ligase 3L confers radioresistance in prostate cancer via Akt pathway

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    Purpose: To determine the effect of Deltex E3 Ubiquitin Ligase 3L (DTX3L) on the radioresistance of prostate cancer (PCa).Methods: A PCa cell model of radioresistance was established via exposure of cancer cell lines to fractionated radiation. The MTT {(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)} assay and western blotting were performed to evaluate the impact of DTX3L on cell survival and DNA damage repair. The molecular mechanism of action was evaluated by western blotting.Results: DTX3L was elevated in PCa cell lines compared with normal primary prostate epithelial cells (p < 0.01). The survival of PCa cells exposed to radiation was promoted by overexpression of DTX3L, while knockdown of DTX3L abrogated the radioresistance. Moreover, overexpression of DTX3Ldecreased phosphorylation of histone H2AX (γH2AX) and increased Rad51 levels (p < 0.01). However, knockdown of DTX3L reversed the accumulation of γH2AX and Rad51. Phosphorylation of AKT was promoted by DTX3L overexpression, but was reduced by DTX3L knockdown (p < 0.01). Inhibition of AKT (protein kinase B) counteracted the promotion ability of DTX3L on the radioresistance of PCa cells via decreased cell survival ratio, and also inhibited DNA damage repair via accumulation of γ-H2AX and depletion of Rad51 (p < 0.01).Conclusion: DTX3L increases the resistance of prostate cancer to radiotherapy and DNA damage repair in PCa via AKT pathway, indicating a potential therapeutic strategy to overcome radioresistance in PCa. Keywords: DTX3L (Deltex E3 Ubiquitin Ligase 3L), DNA damage, Phosphorylation, Radioresistance, AKT, Protein kinase B, Prostate cance

    A Simple Low-Cost Shared-Aperture Dual-Band Dual-Polarized High Gain Antenna for Synthetic Aperture Radars

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    This paper presents a novel shared-aperture dual-band dual-polarized high-gain antenna for potential applications in synthetic aperture radars (SAR). To reduce the complexity of SAR antennas, a dual-band dual-polarized high gain antenna based on the concept of Fabry-Perot resonant cavity is designed. This antenna operates in both C and X bands with a frequency ratio of 1:1.8. To form two separate resonant cavities, two frequency selective surface (FSS) layers are employed, leading to high flexibility in choosing desired frequencies for each band. The beam scanning capability of this proposed antenna is also investigated, where a beam scanning angle range of ±15o is achieved in two orthogonal polarizations. To verify this design concept, three passive antenna prototypes were designed, fabricated and measured. One prototype has broadside radiation patterns whilst the other two prototypes have frozen beam scanned to +15o. The measured results agree well with the simulated ones, showing that high gain, high port isolation, and low cross cross-polarization levels are obtained in both bands. Compared to the conventional high gain dual-band dual-polarized SAR antennas, the proposed antenna has achieved a significant reduction in the complexity, mass, size, loss and cost of the feed network

    Food safety news events classification via a hierarchical transformer model

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    In light of the significance of regulatory authorities and the rising demand for information disclosure, a vast amount of information on food safety news reports is readily accessible on the Internet. The extraction of such information for precise classification and provision of appropriate safety alerts based on their respective categories has emerged as a challenging problem for academic research. Given that most food safety-related events in news reports comprise lengthy text, the pre-trained language models currently employed for text analysis are generally limited in their capability to handle long documents. This paper proposes a long-text classification model utilising hierarchical Transformers. We categorise information in long documents into two distinct types: (1) multiple text chunks meeting the length constraint and (2) essential sentences within long documents, such as headings, paragraph start and end sentences, etc. Initially, our proposed model utilises the text chunks as input to the BERT model. Then, it concatenates the output of the BERT model with the important sentences from the document and use them as input to the Transformer model for feature transformation. Finally, we utilise a classifier for food safety news classification. We conducted several comparative experiments with various commonly used text classification models on a dataset constructed from publicly available information on food regulatory websites. Our proposed method outperforms existing methods, establishing itself as the leading approach in terms of performance. [Abstract copyright: © 2023 The Author(s).

    A Broadband Dual Circularly Polarized Conical Four-Arm Sinuous Antenna

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    A novel wideband four-arm sinuous antenna with dual circular polarizations (CPs) and unidirectional radiation is proposed. Different from the conventional designs, this sinuous antenna is realized in a conical form and no ground plane or absorptive cavity is required to obtain unidirectional radiation. The beamforming network for dual circularly polarized operations consists of a wideband quadrature coupler and two wideband baluns, and an auxiliary feeding patch is introduced to facilitate the connection between baluns and sinuous arms. The design of baluns and coupler is inspired from the printed exponentially tapered microstrip balun and broadside-coupled microstrip coupler, respectively. The dynamic differential evolution algorithm is employed to optimize the geometry of coupler for optimal performance. For both polarizations, the presented antenna has wide impedance bandwidth, good axial ratio, moderate realized gain, and front-to-back ratio within 2–5 GHz. An antenna prototype is fabricated and tested. The agreement between simulation and measurement results validates the proposed antenna framework. The demonstrated antenna has advantages of wide bandwidth, dual CPs, unidirectional radiation, lightweight, and low cost, and is promising for applications in wireless systems

    In Vivo Near-Infrared Imaging of Fibrin Deposition in Thromboembolic Stroke in Mice

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    imaging of activated factor XIII (FXIIIa), an important mediator of thrombosis or fibrinolytic resistance. The present study was to investigate the fibrin deposition in a thromboembolic stroke mice model by FXIIIa–targeted near-infrared fluorescence (NIRF) imaging., which were correlated with histology after animal euthanasia. NIRF images and lesion volume.Non-invasive detection of fibrin deposition in ischemic mouse brain using NIRF imaging is feasible and this technique may provide an in vivo experimental tool in studying the role of fibrin in stroke

    Objective Detection of Tinnitus Based on Electrophysiology

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    Tinnitus, a common disease in the clinic, is associated with persistent pain and high costs to society. Several aspects of tinnitus, such as the pathophysiology mechanism, effective treatment, objective detection, etc., have not been elucidated. Any change in the auditory pathway can lead to tinnitus. At present, there is no clear and unified mechanism to explain tinnitus, and the hypotheses regarding its mechanism include auditory plasticity theory, cortical reorganization theory, dorsal cochlear nucleus hypothesis, etc. Current theories on the mechanism of tinnitus mainly focus on the abnormal activity of the central nervous system. Unfortunately, there is currently a lack of objective diagnostic methods for tinnitus. Developing a method that can detect tinnitus objectively is crucial, only in this way can we identify whether the patient really suffers from tinnitus in the case of cognitive impairment or medical disputes and the therapeutic effect of tinnitus. Electrophysiological investigations have prompted the development of an objective detection of tinnitus by potentials recorded in the auditory pathway. However, there is no objective indicator with sufficient sensitivity and specificity to diagnose tinnitus at present. Based on recent findings of studies with various methods, possible electrophysiological approaches to detect the presence of tinnitus have been summarized. We analyze the change of neural activity throughout the auditory pathway in tinnitus subjects and in patients with tinnitus of varying severity to find available parameters in these methods, which is helpful to further explore the feasibility of using electrophysiological methods for the objective detection of tinnitus

    Coverage of Native Plants Is Key Factor Influencing the Invasibility of Freshwater Ecosystems by Exotic Plants in China

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    Understanding the biotic and abiotic factors that influence the susceptibility of a community to invasion is beneficial for the prediction and management of invasive species and the conservation of native biodiversity. However, the relationships between factors and invasibility of a community have not been fully confirmed, and the factors most associated with the susceptibility of a community to invasion have rarely been identified. In this study, we investigated the species richness patterns in aquatic exotic and native plants and the relationships of exotic species richness with habitat and water environment factors in 262 aquatic plant communities in China. A total of 11 exotic plant species were recorded in our field survey, and we found neither a negative nor a positive relationship between aquatic exotic and native plant species richness. The aquatic exotic plant species richness is negatively correlated with the relative coverage and biomass of native plants but positively correlated with the total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) concentrations in the water. The native plant species richness, native species’ relative coverage, and native species’ biomass were positively related to each other, whereas the TP, TN, and COD were also positively related to each other. The native plant species richness, native species’ relative coverage, and native species biomass were each negatively correlated with the TP, TN, and COD. In addition, biotic rather than abiotic predictors accounted for most of the variation in exotic plant richness. Our results suggest that improving the vegetation coverage and the biodiversity of native plants is the most effective approach for preventing alien plant invasions and minimizing their impacts on freshwater ecosystems

    Experimental Research on Vibration Fatigue of CFRP and Its Influence Factors Based on Vibration Testing

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    A new research method based on vibration testing for the vibration fatigue of FRP was proposed in this paper. Through the testing on a closed-loop controlled vibration fatigue test system, the vibration fatigue phenomenon of typical carbon-fiber-reinforced plastic (CFRP) cantilevered laminate specimens was carefully studied. Moreover, a method based on the frequency response function was proposed to monitor the fatigue damage accumulation of specimens. On the basis of that, the influence factors that affect the vibration fatigue life of CFRP were experimentally studied. The influence of amplitude probability distribution of the vibration load spectrum on the fatigue life was deeply explored. Compared with Gaussian random vibration, the non-Gaussian random load has a significant impact on the vibration fatigue life of CFRP. The experimental results also showed that the magnitude of power spectral density (PSD) has a significant effect on the vibration fatigue life of specimens. For Gaussian vibration load, the frequency bandwidth almost has no effects on the vibration fatigue life of CFRP. However, for non-Gaussian vibration load, it has a great impact on the fatigue life. When PSD magnitude and frequency bandwidth are constant, the root mean square (RMS) is proportional to the vibration fatigue life of composites

    Effect Of Mechanical Milling On Photoluminescence Of Γ-Alumina Nanoparticles

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    The effect of mechanical alloying on the photoluminescence behavior of γ-Al 2O 3 nanopowder was studied. Two emission peaks centered at 343 and 378 nm and a broad emission band ranging between 400-600 nm have been observed. It is found that the intensity of the two emission peaks decreases with ball-milling time, while that the broad band remains un-change. These results suggested that the two peaks are resulted from the surface defects that analogs of F + centers, while the broad band is resulted from impurity. Copyright © 2008 American Scientific Publishers All rights reserved

    An Invasive Clonal Plant Benefits from Clonal Integration More than a Co-Occurring Native Plant in Nutrient- Patchy and Competitive Environments

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    Many notorious invasive plants are clonal, however, little is known about the different roles of clonal integration effects between invasive and native plants. Here, we hypothesize that clonal integration affect growth, photosynthetic performance, biomass allocation and thus competitive ability of invasive and native clonal plants, and invasive clonal plants benefit from clonal integration more than co-occurring native plants in heterogeneous habitats. To test these hypotheses, two stoloniferous clonal plants, Alternanthera philoxeroides (invasive), Jussiaea repens (native) were studied in China. The apical parts of both species were grown either with or without neighboring vegetation and the basal parts without competitors were in nutrient- rich or-poor habitats, with stolon connections were either severed or kept intact. Competition significantly reduced growth and photosynthetic performance of the apical ramets in both species, but not the biomass of neighboring vegetation. Without competition, clonal integration greatly improved the growth and photosynthetic performance of both species, especially when the basal parts were in nutrient-rich habitats. When grown with neighboring vegetation, growth of J. repens and photosynthetic performance of both species were significantly enhanced by clonal integration with the basal parts in both nutrient-rich and-poor habitats, while growth and relative neighbor effect (RNE) of A. philoxeroides were greatly improved by clonal integration only when the basal parts were in nutrient-rich habitats. Moreover, clonal integration increased A. philoxeroides’s biomass allocation to roots without competition, but decreased i
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