Abstract
Tourism places substantial stress on regional land use that can lead to ecological deterioration, greater pollution, destruction of natural habitats, and increasing threats to species ...already in danger of extermination. Improved quality of life is made possible through the Fuzzy Hamacher Correlated Geometric (FHCG) method to observe the growth of multiple attributes in a water-based leisure tourism eco-city. Geographic Information System (GIS) technology, land use maps, and an executive segment satellite image are the main areas of attention for eco-cities as the main focus, which are supported by ecology and environmental space. Hence, FHCG-GIS has designed an environmental carrying capacity in eco-cities that can be increased through tourists who can be accepted in a specific location to fulfill the needs of water tourism, help the destination sector, protect the environment, and reduce the effect. A sensible outcome for evaluating the planning conditions in an eco-city can be found in the estimated indicators of water leisure tourism environmental carrying capacity, predicated on an analysis of scenic geographical resources and tourism economic conditions, and the results of the scenic area's integrated limits using barrel extrapolation.
Abstract Recent efforts have revealed that numerous natural antisense lncRNAs play a crucial role in the regulation of cancer biology. Here, based on our previous study, we further identified that ...the lncRNA FOXC2-AS1 and its antisense transcript FOXC2 were positively up-regulated in doxorubicin-resistant osteosarcoma cell lines and tissues, correlate with poor prognosis and promote doxorubicin resistance in osteosarcoma cells in vitro and in vivo . In addition, FOXC2-AS1 and FOXC2 are mainly located in the cytoplasm and form an RNA–RNA double-stranded structure in the overlapping region, which is necessary for FOXC2-AS1 to regulate the expression of FOXC2 at both the transcription and post-transcription levels. In addition, transcription factor FOXC2 also contributes to doxorubicin resistance through inducing the expression of the classical multi-drug resistance-related ABCB1 gene similar to FOXC2-AS1. Thus, we concluded that the lncRNA FOXC2-AS1 may promote doxorubicin resistance in OS by increasing the expression of transcription factor FOXC2, further facilitating ABCB1 expression. These findings demonstrate the potential underlying mechanism of FOXC2-AS1 in the regulation of doxorubicin resistance in OS and possibly provide a novel reversing target.
Chemo-resistance is a huge obstacle encountered in the osteosarcoma (OS) treatment. Protein-coding mRNAs, as well as non-coding RNAs (ncRNAs), including long ncRNA (lncRNA), circular RNA (circRNA), ...and microRNA (miRNA), have been demonstrated to play an essential role in the regulation of cancer biology. However, the comprehensive expression profile and competing endogenous RNA (ceRNA) regulatory network between mRNAs and ncRNAs in the OS chemo-resistance still remain unclear. In the current study, we developed whole-transcriptome sequencing (RNA sequencing RNA-seq) in the three paired multi-drug chemo-resistant and chemo-sensitive OS cell lines to comprehensively identify differentially expressed lncRNAs, circRNAs, miRNAs, and mRNAs. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed for mRNAs with significantly different expression. Then the ceRNA networks combining lncRNAs, circRNAs, miRNAs, and mRNAs were predicted and constructed on the basis of the authoritative miRanda and TargetScan databases combined with the widely accepted vital drug resistance-related genes and signal transduction pathways. In addition, two constructed ceRNA regulatory pathways, lncRNAMEG3/hsa-miR-200b-3p/AKT2 and hsa_circ_0001258/hsa-miR-744-3p/GSTM2, were randomly selected and validated by real-time qPCR, RNA immunoprecipitation (RIP), RNA pull-down assay, and dual luciferase reporter gene system. Taken together, our findings may provide new evidence for the underlying mechanism of OS chemo-resistance and uncover some novel targets for reversing it.
Zhang et al. identify the comprehensive expression profile and competing endogenous RNA (ceRNA) regulatory network between mRNAs and ncRNAs (long ncRNA lncRNA, circular RNA (circRNA), and microRNA miRNA) in the OS chemo-resistance by whole-transcriptome RNA sequencing, bioinformatics analysis, and assay validation in the three paired multi-drug chemo-resistant and chemo-sensitive OS cell lines.
Circular RNAs (circRNAs) represent a widespread class of non-coding RNAs generated from back-splicing, with a circular loop structure. Many circRNAs have been reported to play essential roles in ...cancer development and have the potential to serve as a novel class of biomarkers for clinical diagnosis. However, the role of circRNA in osteosarcoma (OS) remains largely unknown. In the current study, we examined the expression level of circular RNA PVT1 (circPVT1), previously screened and identified the oncogenic role in gastric cancer, in OS and found that circPVT1 was significantly up-regulated in the OS tissues, serums and chemoresistant cell lines, correlated with poor prognosis of OS patients. Besides, ROC curve demonstrated that circPVT1 may be a better diagnostic biomarker than alkaline phosphatase (ALP) in OS with more sensitivity and specificity. In addition, functional assays revealed that circPVT1 knockdown by siRNA could weaken the resistance to doxorubicin and cisplatin of OS cells through decreasing the expression of classical drug resistance-related gene ABCB1. These findings may provide a new insight into the role of circPVT1 as a biomarker for the diagnosis and treatment target of OS.
Improving energy efficiency has shown increasing importance in designing future cellular system. In this work, we consider the issue of energy efficiency in D2D-enabled heterogeneous cellular ...networks. Specifically, communication mode selection and resource allocation are jointly considered with the aim to maximize the energy efficiency in the long term. And an Markov decision process (MDP) problem is formulated, where each user can switch between traditional cellular mode and D2D mode dynamically. We employ deep deterministic policy gradient (DDPG), a model-free deep reinforcement learning algorithm, to solve the MDP problem in continuous state and action space. The architecture of proposed method consists of one actor network and one critic network. The actor network uses deterministic policy gradient scheme to generate deterministic actions for agent directly, and the critic network employs value function based Q networks to evaluate the performance of the actor network. Simulation results show the convergence property of proposed algorithm and the effectiveness in improving the energy efficiency in a D2D-enabled heterogeneous network.
With the development of wireless communication technology, the need for bandwidth is increasing continuously, and the growing need makes wireless spectrum resources more and more scarce. Cognitive ...radio (CR) has been identified as a promising solution for the spectrum scarcity, and its core idea is the dynamic spectrum access. It can dynamically utilize the idle spectrum without affecting the rights of primary users, so that multiple services or users can share a part of the spectrum, thus achieving the goal of avoiding the high cost of spectrum resetting and improving the utilization of spectrum resources. In order to meet the critical requirements of the fifth generation (5G) mobile network, especially the Wider-Coverage , Massive-Capacity , Massive-Connectivity , and Low-Latency four application scenarios, the spectrum range used in 5G will be further expanded into the full spectrum era, possibly from 1 GHz to 100 GHz. In this paper, we conduct a comprehensive survey of CR technology and focus on the current significant research progress in the full spectrum sharing towards the four scenarios. In addition, the key enabling technologies that may be closely related to the study of 5G in the near future are presented in terms of full-duplex spectrum sensing, spectrum-database based spectrum sensing, auction based spectrum allocation, carrier aggregation based spectrum access. Subsequently, other issues that play a positive role for the development research and practical application of CR, such as common control channel, energy harvesting, non-orthogonal multiple access, and CR based aeronautical communication are discussed. The comprehensive overview provided by this survey is expected to help researchers develop CR technology in the field of 5G further.
It is well known that unmanned aerial vehicles (UAVs) can help terrestrial base stations (BSs) offload data traffic from crowded areas to improve coverage and boost throughput. However, the limited ...backhaul capacity cannot cope with the ever-increasing data demands, for which caching is introduced to relieve the backhaul bottleneck. In this paper, we focus on a multi-UAV assisted wireless network, and target to fully utilize the benefits of wireless caching and UAV mobility for multiuser content delivery. By taking into account the limited storage, our goal is to maximize the minimum throughput among UAV-served users by jointly optimizing cache placement, UAV trajectory, and transmission power in a finite period. The resultant problem is a mixed-integer non-convex optimization problem. To facilitate solving this problem, an alternating iterative algorithm is proposed by adopting the block alternating descent and successive convex approximation methods. Specifically, this problem is split into three subproblems, namely cache placement optimization, trajectory optimization, and power allocation optimization. Then these subproblems are solved alternately in an iterative manner. We show that the proposed algorithm can converge to the set of stationary solutions of this problem. Besides, we further analyze the computational complexity of this algorithm. Numerical results show that great throughput enhancement is achieved by applying our proposed joint design in comparison with other benchmarks without trajectory design and power control.
Abstract
For a given carbon budget over several decades, different transformation rates for the energy system yield starkly different results. Here we consider a budget of 33 GtCO
2
for the ...cumulative carbon dioxide emissions from the European electricity, heating, and transport sectors between 2020 and 2050, which represents Europe’s contribution to the Paris Agreement. We have found that following an early and steady path in which emissions are strongly reduced in the first decade is more cost-effective than following a late and rapid path in which low initial reduction targets quickly deplete the carbon budget and require a sharp reduction later. We show that solar photovoltaic, onshore and offshore wind can become the cornerstone of a fully decarbonised energy system and that installation rates similar to historical maxima are required to achieve timely decarbonisation. Key to those results is a proper representation of existing balancing strategies through an open, hourly-resolved, networked model of the sector-coupled European energy system.
By dispersing Li6.25Ga0.25La3Zr2O12 (Ga-LLZO) nanoparticles in poly(ethylene oxide) (PEO) matrix, PEO:Ga-LLZO composite polymer electrolytes are synthesized. The PEO: Ga-LLZO composite with 16 vol % ...Ga-LLZO nanoparticles shows a conductivity of 7.2 × 10–5 S cm–1 at 30 °C, about 4 orders of magnitude higher than the conductivity of PEO. The enhancement of the ionic conductivity is closely related to the space charge region (∼3 nm) formed at the interface between the PEO matrix and the Ga-LLZO nanoparticles. The space charge region is observed by transmission electron microscope (TEM) and corroborated by the phase-field simulation. Using the random resistor model, the lithium-ion transport in the composite polymer electrolyte is simulated by the Monte Carlo simulation, demonstrating that the enhanced ionic conductivity can be ascribed to the ionic conduction in the space charge regions and the percolation of the space charge regions.
As the most abundant component in black tea, thearubigins (TRs) contribute a lot to black tea's characteristic color, mouthfeel, and potential health benefits. But compared to lower molecular weight ...black tea polyphenols, there are fewer researches that focus on TRs because of their heterogeneity. This review summarized recent research progress on (1) isolation method of TRs; (2) structure analysis and formation mechanism of TRs; (3) biofunctions of TRs, including antioxidation, antimutagenic and anticancer effects, effects on mitochondrial activation, gastrointestinal motility and skeletal health, to show some future research aspects and prospects of TRs.
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