This paper investigates the secure communication issue for cognitive radio networks with nonaltruistic users. The design objective is to improve the secrecy rate of the primary user (PU) and, at the ...same time, create transmission opportunities for the secondary users (SUs) to satisfy their diversified quality-of-service (QoS) demands. To achieve this goal, we propose a novel nonmonetary trading model, where the users are incentivized to participate in the market by a barter-like resource-to-resource exchange. Specifically, the PU leverages the assistance of the SU in the form of cooperative forwarding or friendly jamming and yields part of the spectrum accessing time to the aided SU. The proposed spectrum auction framework jointly formulates the optimal cooperator selection and the corresponding resource allocation problems by taking into consideration the QoS demands of individual users. The proposed framework ensures that bidding truthfully is the dominant strategy for all bidders and, thus, is invulnerable to market manipulation and eliminates the overhead of strategizing over other bidders. Simulation results reveal that the proposed framework could provide substantial gains for both the PU and the aided SU.
Euonymus maackii Rupr. is a small deciduous tree belonging to family Celastraceae. It is an important ornamental tree and a potential medicinal plant resource. Here, we assembled and annotated the ...chloroplast (cp) genome of E. maackii. By combining this genome with seven available cp genomes from Euonymus species, we performed plastome variation analysis of E. maackii and Euonymus. Furthermore, we reconstructed a phylogenetic tree and estimated the differentiation time of E. maackii. The newly assembled cp genome of E. maackii was 157,551 bp in size and had a typical quadripartite structure, which consisted of one large single-copy (LSC 86,524 bp) region, one small single-copy (SSC 18,337 bp) region, and a pair of inverted repeat regions (26,345 bp). A total of 652 single nucleotide polymorphisms (SNPs) and 65 insertions/deletions (indels) were detected between the two cp genomes of E. maackii, with overall genetic variation of 4.1 SNPs per kb or a π value of 0.00443, reflecting a high level of intraspecific variation. Some coding and noncoding regions with higher variation were identified, including trnV-UAC, petN, ycf1-ndhF, trnM-CAU-atpE, rpl2-rpl23, psbZ-trnG-GCC, trnY-GUA-trnE-UUC, trnW-CCA-trnP-UGG, rps16-trnQ-UUG, and psbC-trnS-UGA. The hypervariable coding and noncoding regions in E. maackii were not the same as those in Euonymus. The phylogenetic tree and divergence time based on the whole cp genomes showed that the seven Euonymus species formed a clade, which was sister to that formed with Catha edulis and Maytenus guangxiensis, and they separated 24.74 million years ago. E. maackii and E. hamiltonianus were most closely related, having separated from each other only approximately 2.68 million years ago. Our study provides important genetic information for further studies of E. maackii, such as studies on its phylogeography, population genetics and molecular ecology, and provides new insights into the evolution of the cp genome in Euonymus.
Increasing evidence indicates that long noncoding RNAs play important roles in development and progression of various cancers. Zinc finger antisense 1 is a novel long noncoding RNA whose clinical ...significance, biological function, and underlying mechanism are still undetermined in glioma. In this study, we reported that zinc finger antisense 1 expression was markedly upregulated in glioma and tightly correlated with clinical stage. Moreover, patients with high zinc finger antisense 1 expression had shorter survival. Multivariate Cox regression analysis provided a clue that, probably, zinc finger antisense 1 level could serve as an independent prognostic factor for glioma. Functionally, zinc finger antisense 1 acted as an oncogene in glioma because its knockdown could promote apoptosis and significantly inhibit cell proliferation, migration, and invasion. Furthermore, zinc finger antisense 1 silencing could result in cell cycle arrest at the G0/G1 phase and correspondingly decrease the percentage of S phase cells in both U87 and U251 cell lines. Moreover, it was found that silenced zinc finger antisense 1 could impair migration and invasion by inhibiting the epithelial–mesenchymal transition through reducing the expression of MMP2, MMP9, N-cadherin, Integrin β1, ZEB1, Twist, and Snail as well as increasing E-cadherin level in glioma. Taken together, our data identified that zinc finger antisense 1 might act as a valuable prognostic biomarker and potential therapeutic target for glioma.
Hydraulic fracturing (HF) test has been widely used to determine in situ stress. The use of a conventional continuum method for this purpose has raised considerable controversies concerning field ...tests, particularly in the determination of the maximum horizontal principal stress under preexisting fractures. Fracture mechanics methods are very promising when considering preexisting cracks. However, most fracture mechanics methods do not include the effects of confinement on fracture parameters that depend on confining stress. In the present paper, we proposed a modified approach based on fracture mechanics for stress determination considering the relation between fracture toughness and confining stress based on the Rummel and Abou-Sayed methods. Then, we conducted true triaxial hydraulic fracturing tests under different stress ratios for granite and sandstone specimens to verify the proposed approach. The observed typical pressure-time curves indicate that in the conducted hydraulic fracturing tests, the steady fracture growth was attained. Moreover, we demonstrated that the stress ratios influence crack orientations. The horizontal maximum principal stresses determined using the modified Rummel method achieve the lowest relative error compared with other considered stress estimation approaches. This modified fracture mechanics method could be used as a potential alternative approach to obtain a considerably more precise estimation of the maximum horizontal stress in hydraulic fracturing stress determination.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Research on the mediating mechanisms and boundary conditions of perceived organizational politics’ (POP) effect on employee voice is underdeveloped. Based on conservation of resources theory, we ...proposed a moderated mediation model in which organizational embeddedness acts as a mediator to explain why POP inhibits promotive and prohibitive voice. Additionally, we posited sense of impact as a boundary condition affecting this relationship. A time-lagged survey of 227 employed MBA students from a university in southwestern China revealed that organizational embeddedness mediates the relationship between POP and promotive and prohibitive voice, and sense of impact moderates the relationship between POP and promotive voice, such that the relationship is stronger when sense of impact is weaker. The moderating effect was not significant for prohibitive voice. These findings have implications for theory, practice, and further organizational research.
Despite great advances in the diagnosis and treatment of non-small cell lung cancer (NSCLC), early diagnosis remains a challenge because patients usually have advanced lung cancer at the time they ...are diagnosed. The limited efficacy of conventional chemotherapy is another major problem in the treatment of NSCLC. Based on a published set of sequencing data, we find that hsa_circ_0001946 is a circRNA molecule with a significantly different expression level in three cell lines (human normal lung fibroblasts cell line MRC-5, human NSCLC cell line A549, cisplatin-resistant cell line A549/DDP), NSCLC tissues and paired adjacent normal tissues. We believe that hsa_circ_0001946 may have an effect on the progression of NSCLC and its sensitivity to cisplatin.
We focused on investigating the circular RNA, hsa_circ_0001946. RNA interference of hsa_circ_0001946 was carried out in A549 cell lines to determine the effect of reduced hsa_circ_0001946 expression on lung cancer progression and was analyzed by Cell Counting Kit-8 (CCK-8), 5-ethynyl-20-deoxyuridine, clone formation, Hoechst, wound healing, and transwell assays. The nucleotide excision repair (NER) signaling pathway was identified by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Moreover, cellular responses to cisplatin were assessed through CCK-8 and flow cytometry assays. Western blot analysis and host-cell reactivation assay were used to determine the effect of hsa_circ_0001946 on NER signaling.
In this study, we found that the reduced expression of hsa_circ_0001946 promoted the viability, proliferation, migration, and invasion of NSCLC cells, as well as inhibition of cell apoptosis. Our findings suggest that hsa_circ_0001946 can affect the sensitivity of NSCLC cells to the chemotherapeutic drug cisplatin via modulation of the NER signaling pathway.
Our study demonstrated the role of hsa_circ_0001946 in NSCLC pathogenesis, development, and chemosensitivity, and suggests that hsa_circ_0001946 may serve as a novel biomarker for the diagnosis and prediction of platinum-based chemosensitivity in patients with NSCLC.
Residual stress is generated in GaN epitaxial layers due to the mismatch during GaN epitaxy on sapphire using the traditional method. Therefore, the use of graphene to reduce residual stress and ...dislocation densities in GaN epitaxy has become an important research direction. However, growing a stress-free GaN film on graphene substrate remains challenge. In this work, we directly grew graphene on sapphire via plasma enhanced chemical vapor deposition (PECVD) to obtain an epitaxial graphene with characteristic orientation, and ultra-low stress GaN films can then be obtained through metal organic chemical vapor deposition (MOCVD) assisted with the sputtering AlN buffer layer. Through this method, we successfully obtained continuous and flat GaN films with ultra-low biaxial compressive stress (0.023 GPa) without the complicated stress engineering during epitaxial growth. First principle calculation was employed to confirm that the characteristic orientation of epitaxial graphene is crucial to release the stress in GaN. The obtained GaN films can also be easily transferred because of small van der Waals force on graphene. The transferred GaN heterojunction was directly fabricated into a metal-insulator-semiconductor (MIS) device from which typical electrical properties can be obtained. Our work reveals the stress-releasing mechanism and excellent stress-releasing effect of graphene and provides a new epitaxial strategy to guide crystallographic epitaxy.
•GaN films with ultra-low compressive stress (0.023 GPa) have been achieved successfully.•First principle calculation was employed to confirm that the orientation of graphene is crucial to release the stress in GaN.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
GABA is a dominant inhibitory neurotransmitter in the brain and A type GABA receptor (GABA
A
R) phosphorylation is critical for GABA-mediated inhibitory effect. However, its role in the ...neuroprotective effect of sodium valproate (VPA), a prevalent drug for treating patients with epilepsy, remains elusive. The present study was conducted to explore the role of GABA
A
R phosphorylation in the neuroprotection of VPA against a kainic acid-induced epileptic rat model and the potential molecular mechanisms. Neuronal apoptosis was evaluated by TUNEL assay, PI/Annexin V double staining, caspase-3 activity detection and Bax and Bcl-2 proteins expression via Western blot analysis. The primary rat hippocampal neurons were cultivated and cell viability was measured by CCK8 detection following KA- or free Mg
2+
-induced neuronal impairment. Our results found that VPA treatment significantly reduced neuronal apoptosis in the KA-induced rat model (including reductions of TUNEL-positive cells, caspase-3 activity and Bax protein expression, and increase of Bcl-2 protein level). In the in vitro experiments, VPA at the concentration of 1 mM for 24 h also increased cell survival and suppressed cell apoptosis in KA- or no Mg
2+
-induced models via CCK8 assay and PI/Annexin V double staining, respectively. What is more important, the phosphorylation of γ2 subunit at serine 327 residue for GABA
A
R was found to be robustly enhanced both in the KA-induced epileptic rat model and neuronal cultures following KA exposure after VPA treatment, while no evident alteration was found in terms of GABA
A
R β3 phosphorylation (408 or 409 serine residue). Additionally, pharmacological inhibition of protein kinase C (PKC) clearly abrogated the neuroprotective potential of VPA against KA- or free Mg
2+
-associated neuronal injury, indicating a critical role of PKC in the effect of GABA
A
R γ2 serine 327 phosphorylation in VPA’s protection. In summary, our work reveals that VPA mitigates neuronal apoptosis in KA-triggered epileptic seizures, at least, via augmenting PKC-dependent GABA
A
R γ2 phosphorylation at serine 327 residue.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Summary
A quasi‐proportional resonant (QPR) composite control strategy based on disturbance observer (DOB) is proposed to improve the power quality and dynamic performance of the high‐frequency AC ...distribution system source side. The load DOB normalizes the controlled object while suppressing the load disturbance and improving the system's robustness and dynamic performance of the system. The QPR control strategy is proposed based on the internal mode principle, which improves the tracking capability of the system for the operating frequency band signal, reduces the system output steady‐state error, and suppresses the inverter output voltage harmonics. To adapt to the high bandwidth requirement of the controller for high‐frequency AC inverters, the proposed control strategy based on analogy devices implementation circuit is designed, and the corresponding controller parameters design method is given. Compared with the traditional control strategy, the proposed control strategy can reduce the inverter output voltage harmonics, effectively suppress the load disturbance, and improve the dynamic performance and steady‐state performance of the system. Finally, the experimental platform verifies the feasibility and effectiveness of the proposed control strategy and the designed circuit.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract
Background
Large-scale detection has great potential to bring benefits for containing the COVID-19 epidemic and supporting the government in reopening economic activities. Evaluating the ...true regional mobile severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus nucleic acid testing capacity is essential to improve the overall fighting performance against this epidemic and maintain economic development. However, such a tool is not available in this issue. We aimed to establish an evaluation index system for assessing the regional mobile SARS-CoV-2 virus nucleic acid testing capacity and provide suggestions for improving the capacity level.
Methods
The initial version of the evaluation index system was identified based on massive literature and expert interviews. The Delphi method questionnaire was designed and 30 experts were consulted in two rounds of questionnaire to select and revise indexes at all three levels. The Analytic Hierarchy Process method was used to calculate the weight of indexes at all three levels.
Results
The evaluation index system for assessing the regional mobile SARS-CoV-2 virus nucleic acid testing capacity, including 5 first-level indexes, 17 second-level indexes, and 90 third-level indexes. The response rates of questionnaires delivered in the two rounds of consultation were 100 and 96.7%. Furthermore, the authority coefficient of 30 experts was 0.71. Kendall’s coordination coefficient differences were statistically significant (
P
< 0.001). The weighted values of capacity indexes were established at all levels according to the consistency test, demonstrating that ‘Personnel team construction’ (0.2046) came first amongst the five first-level indexes, followed by ‘Laboratory performance building and maintenance’ (0.2023), ‘Emergency response guarantee’ (0.1989), ‘Information management system for nucleic acid testing resources’ (0.1982) and ‘Regional mobile nucleic acid testing emergency response system construction’ (0.1959).
Conclusion
The evaluation system for assessing the regional mobile SARS-CoV-2 virus nucleic acid testing capacity puts forward a specific, objective, and quantifiable evaluation criterion. The evaluation system can act as a tool for diversified subjects to find the weak links and loopholes. It also provides a measurable basis for authorities to improve nucleic acid testing capabilities.
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CEKLJ, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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