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As one of multi-carrier modulation schemes suitable for 5G/B5G scenarios, the generalized frequency division multiplexing (GFDM) waveform has flexible time-frequency resource distribution. To further reduce out-of-band power leakage of GFDM system, a multiparameter variable GFDM prototype filter is proposed. The flexible configuration of multiparameter method achieves better out-of-band power suppression performances and a precise control of out-of-band power efficiency suppression. Simultaneously, theoretical bit error rate (BER) expression of GFDM system with multiparameter variable filter under frequency selective fading channel is derived. In addition, in order to further improve the BER performance of GFDM system in complex channel scenarios, a message passing (MP) receiver suitable for multiparameter GFDM waveforms is proposed, and the mathematical model of the MP receiving algorithm is given according to the equivalent channel matrix. Simulation results show that the MP receiver can effectively improve the BER performance of GFDM waveform in complex channels. Moreover, the variable filter based on multiparameter can effectively suppress out-of-band power with slight BER loss in comparison with traditional raised cosine (RC) filter. [ABSTRACT FROM AUTHOR]

A long‐standing enigma in oceanography is why terrestrial organic matter is "missing" in the global ocean, despite the considerable discharge into it every year. Although some explanations, such as mineralogical composition, hydrodynamic processes, and priming effect, have been proposed, we hypothesize that the essential mechanism behind the missing organic matter is microbial processing, for which the underlying coupled geochemical, molecular, and genetic evidence is unknown. An ultra‐large‐volume, long‐term river–seawater stratified simulation system was constructed to unravel the microbially driven fate of terrigenous particulate organic matter (POM) in oceans. Analysis of combining the molecular with POM chemical composition data suggests that Bacteroidetes could act as pioneers in the processing of terrigenous POM in oceans, degrading high‐molecular‐weight, high‐carbon compounds such as polysaccharides. Remaining low‐molecular‐weight nitrogenous organic matter is subsequently degraded by Planctomycetes and Proteobacteria. Isotopic signals show that this preferential degradation causes a distinct "aging" effect of POM, and along with nitrification enhanced by remineralization, causes a decrease in the POM C : N ratio. Degradation of terrigenous POM and bacterial biomass biosynthesis leads to positive deviations in δ15N and δ13C. Relatively refractory hydrocarbons, aromatic compounds, and phenols are accumulated by microbial processes in this system. This study provides mechanistic insights into the missing chemical and isotopic signals and microbially driven fate of terrigenous POM in the ocean, with important implications for how riverine material input affects marine carbon and nitrogen cycling. [ABSTRACT FROM AUTHOR]

Link16 data chain is applied to major combat platforms with its strong anis interference ability, but the transmission rate and utilization of Link16 are low. For this problem, a truncated code slit keying (TCSK) method based on one-way coupled map lattice (OCML) spatiotemporal chaotic sequence is proposed in this paper. The system uses spatiotemporal chaotic sequence under the OCML model as base code, then shortens the length of each chip which carries information to the original 1 /P, and mirrors each chip symmetrically to obtain a spread spectrum chip with a total length of 2/P to transmit. Compared with the original sequence, the length of this chip reduces by half to improve the transmission rate of the system. OCML sequences have great pseudo randomness and autocorrelation, and many spread spectrum sequences can be generated under the model, each sequence is unique, so one channel can accommodate lots of spread spectrum signal, which improves the efficiency of bandwidth tremendously. The bit error rate (BER) performance in multipath channel model is simulated, and the simulation results show that the scheme can effectively improve performance of system under multipath fading. [ABSTRACT FROM AUTHOR]

In order to solve the problem of inter-carrier interference (ICI) in fractional Fourier transform orthogonal frequency division multiplexing (FrFT-OFDM) system caused by time-frequency double selective channel, a joint self-cancellation scheme based on ICI self-cancellation coding and frequency offset compensation is proposed. In this scheme, the self-cancellation matrix with phase compensation is used to encode the signal. By taking advantage of the structural advantage of the adjustable rotation angle of the subcarriers in the FrFT-OFDM system, the fractional Fourier transform is carried out under the appropriate rotation angle to compensate the frequency offset, so as to achieve better ICI suppression effect than the traditional ICI self-cancellation technology under the same coding efficiency. The simulation results verify the performance of the scheme. [ABSTRACT FROM AUTHOR]

Objective: To detect the expression level of the Mfn2 gene in hepatocellular carcinoma (HCC) and adjacent normal liver tissues and further analyze its anticancer effects.Methods: The expression levels of Mfn2, GLS1 and the autophagy-related proteins lc3b and Beclin1 in liver cancer and adjacent tissues in patients with liver cancer were detected by real-time-quantitative polymerase chain reaction (RT-qPCR). The HepG2 human HCC cell line was cultured in vitro, and the Mfn2 protein was stably expressed through transfection of a high Mfn2 expression plasmid. The Cell-Counting Kit-8 (CCK-8) method was used to observe the effect of Mfn2 overexpression on the activity of HepG2 cells. Furthermore, RT-qPCR and Western blotting were performed to detect the effects of Mfn2 overexpression on the protein expression of GLS1, Beclin1 and lc3b.Results: Compared with tissues adjacent to cancer tissues, the mRNA levels of Mfn2, GLS1, Beclin1 and lc3b in liver cancer tissues were lower. Compared with normal hepatocytes, the expression of Mfn2, Beclin1 and lc3b in HCC cells was decreased, but the expression of GLS1 was increased. Compared with the control group (NC) transfected with empty plasmid, Mfn2 overexpression led to significant time-dependent inhibition of HepG2 cell activity and GLS1 protein expression (P < .05). In addition, Mfn2 overexpression induced autophagy by triggering the expression of autophagy-related proteins Beclin-1 and lc3b in HCC cells (all P < .05). The effect of transfection with a high-dose Mfn2 plasmid was more obvious than that of transfection with a low-dose Mfn2 plasmid (all P < .05).Conclusions: The expression of Mfn2, GLS1, Beclin1 and lc3b in HCC was lower than in normal liver tissue. The expression of Mfn2, Beclin1 and lc3b in HCC cells was decreased, but the expression of GLS1 was increased. Overexpression of Mfn2 inhibited GLS1 gene expression by inhibiting the activity of HCC cells and promoted the expression of Beclin1 and lc3b to induce autophagy, thereby exerting an anticancer effect. Further research is needed to clarify the mechanism of Mfn2 activity. [ABSTRACT FROM AUTHOR]