Device-to-device (D2D) communication technology is a promising add-on component for future wireless networks to provide local area services with increased spectrum efficiency and improved user ...experience. Three modes (i.e., cellular mode, reuse mode, and dedicated mode) can be used for D2D communication. A potential D2D user equipment (UE) can select a communication mode and dynamically adapt the mode selection according to the performance and the cost. This is referred to as the user-controlled mode selection problem. Also, a base station (BS) needs to reserve a spectrum band for the dedicated mode of operation, which we refer to as spectrum partitioning. The optimal spectrum partitioning needs to consider the utility of the BS that depends on the distribution of the users' mode selection, which, in turn, is governed by the spectrum partitioning. To jointly address the problems of spectrum partitioning and user-controlled mode selection (which are cyclically dependent on each other), we propose a dynamic Stackelberg game framework in which the BS and the potential D2D UEs act as the leader and the followers, respectively. Specifically, the adaptive mode selection of potential D2D UEs is formulated as a follower evolutionary game, and an evolutionary stable strategy is considered to be the solution. The dynamic control of spectrum partitioning by the BS is formulated as a leader optimal control problem. We also extend the formulation by considering information delays in control and state. Numerical analysis is performed to evaluate the effectiveness of the proposed framework, which shows that although the mode selection is performed in a distributed and user-controlled manner, the dynamic spectrum partitioning can be viewed as an effective incentive mechanism to drive the user distribution close to the optimal one.
Chemoresistance has been an obstacle in the further improvement of 5‐year survival rates of osteosarcoma (OS) patients, but the underlying mechanism of chemo‐resistance remains unclear. A ...comprehensive analysis of mRNAs and noncoding RNAs related to OS chemo‐resistance could help solve this problem. In the current study, we first identified that fibronectin‐1 (FN1), screened by microarray analysis in three paired chemo‐resistant and chemo‐sensitive OS cell lines, was significantly upregulated in the chemo‐resistant OS cell lines and tissues and was related to unfavourable prognosis. Further functional assays revealed that FN1 inhibition greatly increased the sensitivity of OS cells to doxorubicin in vitro and in vivo, whereas FN1 overexpression had the opposite effect. Moreover, mechanistic investigation demonstrated, by a series of assays that included luciferase reporter gene, RNA immunoprecipitation, RNA pull‐down and rescue assays, that FN1 expression was regulated by the oncogenic long noncoding RNA (lncRNA) OIP5‐AS1 through sponging miR‐200b‐3p. Thus, these results indicated the role and potential application of the lncRNA OIP5‐AS1/miR‐200b‐3p/FN1 regulatory pathway as a promising target in treatment of OS chemo‐resistance.
First report about expression, function and potential clinical significance of fibronectin‐1 (FN1), miR‐200b‐3p, lncRNA OIP5‐AS1 in osteosarcoma (OS) doxorubicin resistance; Regulatory mechanism of FN1 expression was identified and lncRNA OIP5‐AS1/miR‐200b‐3p/FN1 regulatory pathway was first constructed in OS doxorubicin resistance.
Recent findings have shown that lncRNA dysregulation is involved in many cancers, including osteosarcoma (OS). In a previous study, we reported a novel lncRNA, ODRUL, that could promote doxorubicin ...resistance in OS. We now report the function and underlying mechanism of ODRUL in regulating OS progression. We show that ODRUL is upregulated in OS tissues and cell lines and correlates with poor prognosis. ODRUL knockdown significantly inhibits OS cell proliferation, migration, invasion, and tumor growth in vitro and in vivo by decreasing matrix metalloproteinase (MMP) expression. A microarray screen combined with online database analysis showed that miR-3182 is upregulated and MMP2 is downregulated in sh-ODRUL-expressing MG63 cells and that miR-3182 harbors potential binding sites for ODRUL and the 3′ UTR of MMP2 mRNA. In addition, miR-3182 expression and function are inversely correlated with ODRUL expression in vitro and in vivo. A luciferase reporter assay demonstrated that ODRUL could directly interact with miR-3182 and upregulate MMP2 expression via its competing endogenous RNA activity on miR-3182 at the posttranscriptional level. Taken together, our study has elucidated the role of oncogenic ODRUL in OS progression and may provide a new target in OS therapy.
ODRUL is upregulated in osteosarcoma, correlates with poor prognosis, and promotes osteosarcoma progression in vitro and in vivo. ODRUL regulates MMP2 expression through competitively binding to miR-3182, whose expression and function inversely correlate with that of ODRUL. In conclusion, ODRUL contributes to osteosarcoma progression through the miR-3182/MMP2 axis.
•From 2003 to 2020, Fractional Vegetation Cover (FVC) increased at a rate of 0.19•Due to the differences in topography and landforms, the FVC in the Yellow River Basin presents obvious spatial ...differences.•FVC in 73% of the basin shows high stability.•There is obvious seasonal characteristics of FVC in the basin.
The Yellow River occupies a pivotal strategic position in the development and economic construction of China. Moreover, grasping the dynamics of change in long-term vegetation cover and predicting future trends in the Yellow River Basin could provide an empirical foundation for improved ecological protection and soil and water conservation initiatives. This study uses statistical methods such as Dimidiate pixel model, linear regression, Moran’s index, and coefficient of variation to conduct a spatio-temporal analysis of the vegetation coverage in the Yellow River Basin. The Hurst exponent is used for further analysis of the trend of change in the vegetation coverage across the study area. The results show that from 2003 to 2020, the fractional vegetation coverage (FVC) in the Yellow River Basin increased at an average rate of 0.19% per year. Furthermore, only 2.22% of the area of the Yellow River Basin shows a relative increase in FVC from 2003 to 2020; most of the increased area is located in the northwestern Loess Plateau. The Global Moran index values from 2003 to 2020 are all greater than 0.8, indicating that the vegetation coverage presents a strong agglomeration. According to the Local Moran index, the vegetation coverage of the Yellow River Basin presents a strong spatial difference. According to the coefficient of variation, 73% of the vegetation coverage in the Yellow River Basin has been highly stable over the past 18 years. In addition, the overall Hurst exponent for the FVC in the Yellow River Basin is less than 0.5, indicating a anti-persistence pattern of change in vegetation.
By connecting multiple short, local low-density parity-check (LDPC) codes with a global parity check, the globally coupled (GC) LDPC code can attain high performances with low complexities. The ...typical design of a local code is a quasi-cyclic (QC) LDPC for which the code length is proportional to the size of circulant permutation matrix (CPM). The greatest common divisor (GCD)-based full-length row multiplier (FLRM) matrix is constrained by a lower bound of CPM size to avoid six length cycles. In this paper, we find a new lower bound for the CPM size and propose an algorithm to determine the minimum CPM size and the corresponding FLRM matrix. Based on the new lower bound, two methods are proposed to construct the GC-QC-LDPC code of grith 8 based on the GCD based FLRM matrix. With the proposed algorithm, the CPM size can be 45% less than that given by sufficient condition of girth 8. Compared with the conventional GC-LDPC construction, the codes constructed with the proposed method have improved performance and are more flexible in code length and code rate design.
The double spike (DS) technique has an advantage over other correction models for correcting isotopic fractionation during chemical separation. However, previous studies have revealed a correlation ...between measurements and DS proportions in some elements and even more sensitivity to DS proportions, showing inconsistency between experimental results and theoretical expectations, whereas the exact reason is unclear. This study takes Zn with a
66
Zn-
70
Zn DS combination as a representative to explore the cause of the over-sensitive DS proportion effect. The effect of different DS proportions (0.1-0.9) on isotopic analyses was determined. An inverse correlation was observed between
δ
66
Zn and DS proportions in a limited range (0.46-0.48), which differs from the theoretical prediction. High-resolution observation and concentration gradient demonstrate that isobaric interference is negligible and not responsible for the sensitive DS proportion effect. The good linear regression of the three isotope-plot for IRMM-3702 measured values shows that the exponential law is valid in this study. The fractionation factor
β
calculated using the exponential law shows that the
β
values of the same isotope pairs at different analytical sessions vary considerably, implying that the
β
values change with every setup with no fixed pattern. And
β
values of
66/64
Zn,
67/64
Zn,
68/64
Zn, and
70/64
Zn are not equal in the same sessions, indicating the existence of MIF which is responsible for the sensitive DS proportion effect. Since
β
values have no fixed pattern and vary within measurement error in a period, they can be used to correct the MIF. After correction, the correlation between
δ
66
Zn and DS proportions was corrected, and the DS proportions are comparable to the theoretical predictions, ranging from 0.35 to 0.7. Simulations with
β
values revealed that
β
values can vary within a certain range without introducing additional errors in one setup. The corrected long-term reproducibility of CAGS-Zn relative to IRMM-3702 is −0.885 ± 0.022‰, and the corrected Zn isotopic compositions of reference materials agreed with previous studies within 2sd. This paper identifies the cause of the sensitive DS proportion effect and proposes a feasible correction scheme, further emphasizing that instrumental MIF is not a surprise and should be valued in the DS technique.
Mass-independent fractionation during Zn isotope analysis by MC-ICP-MS is identified, which is responsible for the sensitive DS ratio effect. Using the correction method proposed, the results obtained are consistent with theoretical predictions.
The late Ediacaran to early Cambrian interval witnessed extraordinary radiations of metazoan life. The role of the physical environment in this biological revolution, such as changes to oxygen levels ...and nutrient availability, has been the focus of longstanding debate. Seemingly contradictory data from geochemical redox proxies help to fuel this controversy. As an essential nutrient, nitrogen can help to resolve this impasse by establishing linkages between nutrient supply, ocean redox, and biological changes. Here we present a comprehensive N-isotope dataset from the Yangtze Basin that reveals remarkable coupling between δ
N, δ
C, and evolutionary events from circa 551 to 515 Ma. The results indicate that increased fixed nitrogen supply may have facilitated episodic animal radiations by reinforcing ocean oxygenation, and restricting anoxia to near, or even at the sediment-water interface. Conversely, sporadic ocean anoxic events interrupted ocean oxygenation, and may have led to extinctions of the Ediacaran biota and small shelly animals.
Epigallocatechin-3-gallate (EGCG) is the major polyphenolic compound present in green tea and is generally regarded as an effective antioxidant. However, its chemical reactivity makes it susceptible ...to generate reactive oxygen species (ROS) via autooxidation and exhibit prooxidant effects. The prooxidant actions of EGCG could play a dual role, being both beneficial and harmful. This review summarized recent research progress on (1) the anticancer, antiobesity, and antibacterial effects of EGCG and (2) the possible toxicity of EGCG. The major focus is on the involvement of prooxidant effects of EGCG and their effective doses used. Considering dosage is a crucial factor in the prooxidant effects of EGCG; further studies are required to find the appropriate dose at which EGCG could bring more health benefits with lower toxicity.
As one of the most promising applications in future Internet of Things, Internet of Vehicles (IoV) has been acknowledged as a fundamental technology for developing the Intelligent Transportation ...Systems in smart cities. With the emergence of the sixth generation (6G) communications technologies, massive network infrastructures will be densely deployed and the number of network nodes will increase exponentially, leading to extremely high energy consumption. There has been an upsurge of interest to develop the green IoV towards sustainable vehicular communication and networking in the 6G era. However, as a special mobile ad-hoc network, the energy cost in an IoV system involves the communication and computation energy in addition to the fuel consumption and the electricity cost of moving vehicles. Moreover, the energy harvesting technology, which is likely to be adopted widely in 6G systems, will complicate the optimization of energy efficiency in the entire system. Current studies focus only on part of the energy issues in IoV systems without a comprehensive discussion of the state-of-the-art energy-efficient approaches and the influence of the development of 6G networks on green IoV. In this paper, we present the main considerations for green IoV from five different scenarios, including the communication, computation, traffic, Electric Vehicles (EVs), and energy harvesting management. The literature relevant to each of the scenarios is compared from the perspective of energy optimization (e.g., with respect to resource allocation, workload scheduling, routing design, traffic control, charging management, energy harvesting and sharing) and the related factors affecting energy efficiency (e.g., resource limitation, channel state, network topology, traffic condition). In addition, we introduce the potential challenges and the emerging technologies in 6G for developing green IoV systems. Finally, we discuss the research trends in designing energy-efficient IoV systems.
We consider the problem of robust downlink power control in orthogonal frequency-division multiple access (OFDMA)-based heterogeneous wireless networks (HetNets) composed of macrocells and ...underlaying small cells. A non-cooperative setting is assumed where the macro base stations (MBSs) and small cell base stations (SBSs) compete with each other to maximize their own capacities considering imperfect channel state information. A robust Stackelberg game (RSG) is formulated to model this hierarchical competition where the MBSs and SBSs act as the leaders and the followers, respectively. The formulated RSG can be expressed as an equilibrium program with equilibrium constraints (EPEC). A comprehensive study of this RSG is provided considering various power constraints (e.g., total and spectral mask), various interference constraints (e.g., individual and global), and different uncertainty models (e.g., column-wise and ellipsoidal). We show how the different constraints and uncertainty models change the property of the game (e.g., Nash equilibrium problem (NEP) or generalized Nash equilibrium problem (GNEP)) and accordingly impact the choice of analysis method (e.g., game theory or variational inequality (VI)), solution (e.g., closed-form or numerical), and the design of algorithms and their distributive properties (e.g., totally distributed, semi-distributed, and centralized). A robust Stackelberg equilibrium (RSE) is considered to be the solution and its existence and uniqueness are investigated. Also, algorithms are proposed to arrive at the RSE. Numerical results show the effectiveness of robust solutions in an imperfect information environment.
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