Flexible Coherent Optical Access: Architectures, Algorithms, and Demonstrations

To cope with the explosive bandwidth demand, significant progress has been made in the ITU-T standardization sector to define a higher-speed passive optical network (PON) with a 50Gb/s line rate. Recently, 50G PON becomes mature gradually, which means it is time to discuss beyond 50G PON. For ensuring an acceptable optical power budget, beyond 50G PON will potentially use coherent technologies, which can simultaneously promote the applications of flexible multiple access such as time/frequency-domain multiple access (TFDMA). In this paper, we will introduce the architectures, algorithms, and demonstrations for TFDMA-based coherent PON. The system architectures based on an ultra-simple coherent transceiver and specific signal spectra are designed to greatly reduce the cost of ONUs. Meanwhile, fast and low-complexity digital signal processing (DSP) algorithms are proposed for dealing with upstream and downstream signals. Based on the architectures and algorithms, we experimentally demonstrate the first real-time TFDMA-based coherent PON, which can support at most 256 end users, and peak line rates of 100Gb/s and 200Gb/s in the upstream and downstream scenarios, respectively. In conclusion, the proposed technologies for the coherent PON make it more possible to be applied in the future beyond 50G PON.Comment: The paper has been submitted to the Journal of Lightwave Technolog

Optimization of AICD water control completion technology for horizontal well in bottom water gas reservoir

At present, adaptive inflow control (AICD) water-controlled completion technology is mainly applied to reservoir water control. In view of the gas reservoir AICD water control completion technology research is still blank, this paper carried out a suitable for gas reservoir water control water control mechanism of the new type runner AICD and flow characteristics analysis, X oilfield bottom water reservoir is established new port type AICD water control completion. The structure parameter combination of the new AICD was analyzed and optimized by orthogonal test, and the water control effect of the new AICD water control completion was analyzed. The results show that compared with conventional perforation completions, the new AICD controlled water completions cause little bottom hole pressure loss and have little effect on condensate production. New type runner AICD completion can prolong the bottom water reservoir water control in low yielding water gas recovery period of about 365 days, predict 20 years of accumulated water rate reduced about 27%, water saturation near wellbore area is generally lower, has good effect of water control. The new flow channel type AICD controlled water completion can be applied to the development of bottom water gas reservoirs to control water and stabilize gas

Evaluation of influencing factors on the adaptability of ICD completion technology

After years of research and practice, ICD well completion technology has become a relatively mature completion technology, and has been successfully applied in hundreds of horizontal Wells abroad. However, due to many factors affecting ICD effect, mature evaluation methods have not been completely established. At present, the main index of ICD water control development effect is to balance inflow profile and inhibit water production, and the evaluation factors involve reservoir, process and equipment structure. This paper summarizes the factors influencing the effects of ICD, using orthogonal experiment design method to carry on the comprehensive evaluation, and puts forward the corresponding Suggestion

Effects of Microplastics on Expression of Resistance Genes and Virulence Genes of Vibrio alginolyticus

[Objectives] To study the effects of microplastics on antibiotic resistance genes and virulence genes of Vibrio alginolyticus, so as to provide a certain reference for controlling marine pollution, curbing the spread of environmental antibiotic resistance genes and virulence genes, formulating environmental policies, and maintaining food safety. [Methods] After adding V. alginolyticus into the artificial seawater, they were divided into three groups, namely blank control group (BLK), polyvinyl chloride microplastic group (PVC group) and polyvinyl alcohol microplastic group (PVA group). Aerated culture experiments were carried out, and the effects of microplastics on the expression of resistance genes and virulence genes of V. alginolyticus were studied by PCR and qPCR methods. [Results] The presence of microplastics significantly changed the resistance gene structure of V. alginolyticus. Compared with the control group, the cfxA and cfr resistance genes were detected in the microplastic group. However, only PVC group detected blaZ resistance gene, and only PVA group did not detect aaC resistance gene. In addition, compared with the control group, the expressions of virulence genes in the microplastic group were all down-regulated (P<0.01). [Conclusions] This study provides some reference for curbing the spread of environmental antibiotic resistance genes and virulence genes, formulating environmental policies, and maintaining food safety, but the specific mechanisms of drug resistance and virulence need further research

Effects of Microplastics on Expression of Resistance Genes and Virulence Genes of Vibrio alginolyticus

[Objectives] To study the effects of microplastics on antibiotic resistance genes and virulence genes of Vibrio alginolyticus, so as to provide a certain reference for controlling marine pollution, curbing the spread of environmental antibiotic resistance genes and virulence genes, formulating environmental policies, and maintaining food safety. [Methods] After adding V. alginolyticus into the artificial seawater, they were divided into three groups, namely blank control group (BLK), polyvinyl chloride microplastic group (PVC group) and polyvinyl alcohol microplastic group (PVA group). Aerated culture experiments were carried out, and the effects of microplastics on the expression of resistance genes and virulence genes of V. alginolyticus were studied by PCR and qPCR methods. [Results] The presence of microplastics significantly changed the resistance gene structure of V. alginolyticus. Compared with the control group, the cfxA and cfr resistance genes were detected in the microplastic group. However, only PVC group detected blaZ resistance gene, and only PVA group did not detect aaC resistance gene. In addition, compared with the control group, the expressions of virulence genes in the microplastic group were all down-regulated (P<0.01). [Conclusions] This study provides some reference for curbing the spread of environmental antibiotic resistance genes and virulence genes, formulating environmental policies, and maintaining food safety, but the specific mechanisms of drug resistance and virulence need further research

Molecular Cloning, Bioinformatics Analysis and Transcriptional Expression of Virulence-related Gene (exsA) of Vibrio alginolyticus

iology techniques to analyze its biological information. Fluorescence quantitative PCR technology was used to analyze the expression of exsA after different media stress. [Results] The exsA gene contains an open reading frame (ORF) of 861 bp, encoding 286 amino acids. The physico-chemical analysis shows that the molecular structural formula is C1442H2267N393O441S12, the theoretical molecular weight is 32.549 kD, the theoretical pI value is 6.0, and the protein is non-hydrophilic and unstable. The gene does not contain a transmembrane region, and there is no obvious signal peptide. The prediction result of protein subcellular localization shows that the protein is inside the cell. The deduced amino acid sequence and constructed phylogenetic tree show that V. alginolyticus has a close relationship with Vibrio antiquarius. The qPCR results show that the expression level of exsA in different media is different, highest in TSB medium containing bile salts, followed by DMEM medium, and lowest in ordinary TSB medium. [Conclusions] The gene sequence, molecular structure and isoelectric point of exsA, as well as its expression in three different media were obtained

Cloning and Bioinformatics Analysis of vscB Gene of T3SS Chaperone of Vibrio alginolyticus

[Objectives] To clone and analyze the vscB gene of Vibrio alginolyticus HY9901 by bioinformatics. [Methods] A pair of specific primers were designed according to the vscB gene sequence of Vibrio alginolyticus HY9901. The full length of the primers was cloned by PCR and analyzed by bioinformatics. [Results] The vscB gene was 429 bp long, encoding 142 amino acids, with a theoretical molecular weight of 16.4 kDa and a pI value of 5.48. Amino acid sequence analysis of VscB showed that VscB was not a secretory protein, without signal peptide and transmembrane region, and there were protein kinase C phosphorylation site and casein kinase II phosphorylation site in the sequence. Homologous comparison of amino acid sequences showed that VscB of V. alginolyticus had the highest protein similarity with Vibrio Parahaemolyticus, reaching 91%. Phylogenetic tree analysis showed that the corresponding proteins of V. alginolyticus VscB, Vibrio Parahaemolyticus and Vibrio diabolicus were clustered in the same subfamily. Functional domain analysis showed that it had CesT family domain. Tertiary structure prediction showed that there were 3 α-helices and 5 β-turns in VscB protein. [Conclusions] This study provided a theoretical basis for further study on the function of chaperone of V. alginolyticus

Functional characterization of Vibrio alginolyticus T3SS regulator ExsA and evaluation of its mutant as a live attenuated vaccine candidate in zebrafish (Danio rerio) model

Vibrio alginolyticus, a Gram-negative bacterium, is an opportunistic pathogen of both marine animals and humans, resulting in significant losses in the aquaculture industry. Type III secretion system (T3SS) is a crucial virulence mechanism of V. alginolyticus. In this study, the T3SS regulatory gene exsA, which was cloned from V. alginolyticus wild-type strain HY9901, is 861 bp encoding a protein of 286 amino acids. The ΔexsA was constructed by homologous recombination and Overlap-PCR. Although there was no difference in growth between HY9901 and ΔexsA, the ΔexsA exhibited significantly decreased extracellular protease activity and biofilm formation. Besides, the ΔexsA showed a weakened swarming phenotype and an ~100-fold decrease in virulence to zebrafish. Antibiotic susceptibility testing showed the HY9901ΔexsA was more sensitive to kanamycin, minocycline, tetracycline, gentamicin, doxycycline and neomycin. Compared to HY9901 there were 541 up-regulated genes and 663 down-regulated genes in ΔexsA, screened by transcriptome sequencing. qRT-PCR and β-galactosidase reporter assays were used to analyze the transcription levels of hop gene revealing that exsA gene could facilitate the expression of hop gene. Finally, Danio rerio, vaccinated with ΔexsA through intramuscular injection, induced a relative percent survival (RPS) value of 66.7% after challenging with HY9901 wild type strain. qRT-PCR assays showed that vaccination with ΔexsA increased the expression of immune-related genes, including GATA-1, IL6, IgM, and TNF-α in zebrafish. In summary, these results demonstrate the importance of exsA in V. alginolyticus and provide a basis for further investigations into the virulence and infection mechanism

Enhancing Postharvest Quality and Antioxidant Capacity of Blue Honeysuckle cv. ‘Lanjingling’ with Chitosan and Aloe vera Gel Edible Coatings during Storage

This study investigated the impact of chitosan (CH, 1%) and aloe vera gel (AL, 30%) edible coatings on the preservation of blue honeysuckle quality during a 28-day storage at −1 °C. Coating with CH, AL, and CH+AL led to notable enhancements in several key attributes. These included increased firmness, total soluble solids, acidity, pH, and antioxidant capacity (measured through DPPH, ABTS, and FRAP assays), as well as the preservation of primary (ascorbic acid) and secondary metabolites (TPC, TAC, and TFC). The TAC and TFC levels were approximately increased by 280% and 17%, respectively, in coated blue honeysuckle after 28 d compared to uncoated blue honeysuckle. These coatings also resulted in reduced weight loss, respiration rate, color, abscisic acid, ethylene production, and malondialdehyde content. Notably, the CH+AL treatment excelled in preserving secondary metabolites and elevating FRAP-reducing power, demonstrating a remarkable 1.43-fold increase compared to the control after 28 days. Overall, CH+AL exhibited superior effects compared to CH or AL treatment alone, offering a promising strategy for extending the shelf life and preserving the quality of blue honeysuckle during storage

Cloning and Bioinformatics Analysis of TpiA Gene of Vibrio alginolyticus HY9901

[Objectives] To clone and analyze the TpiA gene of Vibrio alginolyticus HY9901. [Methods] According to the TpiA gene sequence of V. alginolyticus, a pair of specific primers was designed, and its full length was amplified by PCR. [Results] The full length of TpiA gene is 771 bp, encoding 256 amino acid residues in total, and the NCBI accession number is OM906798. According to the deduced amino acid sequence, its molecular weight was predicted to be about 26.975 48 kDa, and its isoelectric point was 4.78. The amino acid sequence of the N-terminal signal peptide structure was predicted, and it was found that there was no obvious signal peptide cleavage site, no signal peptide, and no transmembrane region; the amino acid sequence contained 3 N-glycosylation sites, 4 protein kinase C phosphorylation sites, 2 casein kinase II phosphorylation sites, 6 N-myristoylation sites, 7 microbody C - terminal target signal site, and 1 triose phosphate isomerase active site. The prediction results of protein subcellular localization showed that TpiA may be located in mitochondria or cytoplasm, with probability of 39.1% and 34.8%, respectively. The amino acid sequence of the TpiA gene of V. alginolyticus shared 98.83%-99.61% homology with other Vibrio species, and it was clustered into the same subfamily with Vibrio parahaemolyticus and had a close relationship. In the secondary structure prediction, the proportions of α-helix, random coil and extended chain were 44.53%, 41.41% and 14.06%, respectively, and the similarity of its tertiary structure model to template 1aw1.1.A was 85.16%. [Conclusions] This study is intended to provide a basis for further research on the role of TpiA gene in the type III secretion system and related research on antibiotic resistance