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1.
R Soc Open Sci ; 8(11): 210584, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34849239

RESUMO

Low-expansion alloys are of great importance and can be used for the development of new aerospace materials. Herein, we report diverse rare earth quasicrystal alloys fabricated by the vacuum suction casting process. The effects of the addition of cerium (Ce) on the microstructure, thermal expansion properties and microhardness of the Al-Cu-Fe alloy were systematically investigated. This study discovered the tiny Al-Cu-Fe-Ce microstructure. A uniform distribution could be achieved after Ce addition amount is elevated. At the Ce addition amount of 1 at%, the lowest alloy thermal expansion coefficient was obtained. The alloy exhibited the maximum microhardness under these conditions. The microhardness of alloys containing 1 at% of Ce was approximately 2.4 times higher than the microhardness exhibited by alloys devoid of Ce additives. The coefficient of thermal expansion decreases by approximately 20%. The use of the suction casting process and the addition of an appropriate amount of Ce can potentially help design and develop Al-Cu-Fe-Ce alloys.

2.
Anim Biotechnol ; : 1-9, 2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34747678

RESUMO

MiRNAs as a series of small noncoding RNAs that play a crucial part in regulating coat color and hair follicle development. In the previous Solexa sequencing experiments, there were many miRNAs expressed differentially in alpacas with different coat color, including miR-193b.But the mechanism of miR-193b in mammalian pigmentation is still unknown. In this study, bioinformatics analysis showed that WNT10A and GNAI2 might be the target genes of miR-193b. qRT-PCR showed the expression of miR-193b in white Cashmere goats' skins was obviously lower than that in browns, and the expression of WNT10A and GNAI2 were similar with miR-193b. The protein levels of WNT10A and GNAI2 indicated the same findings. Furthermore, the expression of WNT10A and GNAI2 in keratinocytes were analyzed from mRNA and protein levels, the results manifested that the group of overexpression of miR-193b in HaCaT cells increased the expressions of target genes, and miR-193b inhibition group reduced expressions. Luciferase report assays confirmed that the targeting relationship between miR-193b and target genes (WNT10A and GNAI2), the results showed that miR-193b was positively correlated with target genes. These experimental data showed that miR-193b might participate in adjustment of coat color in skin tissue of Cashmere goat by targeting WNT10A and GNAI2.

3.
Int Heart J ; 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34789648

RESUMO

The side branch (SB) provisional stenting strategy is currently the recommended approach for most coronary bifurcation lesions. However, this strategy may result in SB deterioration, which is associated with an increased incidence of periprocedural myocardial infarction (PMI) and may adversely affect the long-term prognosis. Various techniques for SB protection (SB-P) have been developed to reduce SB occlusion and improve the clinical prognosis. This meta-analysis was performed to compare the outcomes of an active SB-P strategy of jailed balloon technique, balloon-stent kissing technique, and jailed Corsair technique versus the conventional SB-P strategy based on jailed wire technique.This meta-analysis included 5 studies (4 randomized and 1 observational) involving a total of 1,174 patients in whom the active and conventional SB-P strategies were compared. Fixed- and random-effects models were used to calculate summary risk ratios (RRs).The risk of SB occlusion was significantly lower in active SB-P strategy [RR 0.47, 95% confidence interval (CI) 0.30-0.73 in fixed-effect model; RR 0.52, 95% CI 0.31-0.87 in random-effect model]. The risk of PMI was similar between the two strategies (RR 0.63, 95% CI 0.30-1.33 in fixed-effect model; RR 0.71, 95%CI 0.20-2.48 in random-effect model). The rate of long-term major adverse cardiovascular events was similar between the groups (RR 0.48, 95% CI 0.15-1.48 in fixed-effect model; RR 0.49, 95% CI 0.16-1.52 in random-effect model).The active SB-P strategy in coronary bifurcation lesions is associated with reduced SB deterioration, but it does not decrease PMI or improve the long-term prognosis.

4.
Int J Hyg Environ Health ; 239: 113878, 2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-34757311

RESUMO

AIM: The precise pathophysiologic pathway linking traffic-related air pollution (TRAP) to diabetes mellitus is not well elucidated. We aimed to investigate whether activation of vascular inflammation can be a mechanistic linkage between ambient TRAP and insulin resistance. METHODS: Study outcomes were determined by assessing a series of circulating biomarkers indicative of insulin resistance and vascular inflammation among 73 healthy adults who underwent repeated clinical visits in Beijing, China, 2014-2016. Concomitantly, concentrations of ambient TRAP indices, including particulate matter in diameter <2.5 µm (PM2.5), particles in size fractions of 5-560 nm, black carbon, carbon monoxide, nitrogen dioxide, and oxides of nitrogen, were continuously monitored. RESULTS: Participants experienced extremely high levels of TRAP exposures, with mean (standard deviation) PM2.5 concentrations of 91.8 (48.3) µg/m3, throughout the study. We found that interquartile range increases in exposure to moving average concentrations of various TRAP indices at prior up to 7 days were associated with significant elevations of 8.9-49.6% in insulin levels. Higher pollutant levels were also related to worsening metrics of insulin resistance (soluble insulin receptor ectodomain, adipokines, and homeostasis model assessment of insulin resistance) and heightened vascular inflammatory responses, particularly disruptions of the receptor activator of nuclear factor κB ligand/osteoprotegerin system balance and elevations of monocyte/macrophage and T cell activation markers. Mediation analyses showed that activation of vascular inflammation could explain up to 66% of the alterations in metrics of insulin resistance attributable to air pollution. CONCLUSION: Our results suggest that ambient traffic pollution exposure was capable of promoting insulin resistance possibly via generating vascular inflammation.

5.
Front Nutr ; 8: 734580, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34805240

RESUMO

Background: The association between plasma vitamin E levels and first stroke risk in men and women remains unclear. Objective: We aimed to examine the prospective association between plasma vitamin E and first stroke, and evaluate the effect modifiers for the association, among hypertensive patients. Design: The study sample was drawn from the China Stroke Primary Prevention Trial (CSPPT), which randomized a total of 20,702 hypertensive patients to a double-blind, daily treatment with either 10 mg enalapril and 0.8 mg folic acid or 10 mg enalapril alone. This nested case-control study, including 618 first stroke cases and 618 controls matched for age, sex, treatment group, and study site, was conducted after the completion of the CSPPT. Results: The median follow-up duration was 4.5 years. Among men, a significantly higher risk of first stroke (adjusted OR, 1.67; 95%CI: 1.01, 2.77) was found for those with plasma vitamin E ≥7.1 µg/mL (≥quartile 1) compared with those with plasma vitamin E < 7.1 µg/mL. Subgroup analyses further showed that the association between vitamin E (≥7.1 vs. <7.1 µg/mL) and first stroke in men was significantly stronger in non-drinkers (adjusted OR, 2.64; 95%CI: 1.41, 4.96), compared to current drinkers (adjusted OR, 0.84; 95% CI: 0.43, 1.66, P-interaction = 0.008). However, there was no significant association between plasma vitamin E and first stroke in women (P-interaction between sex and plasma vitamin E = 0.048). Conclusions: Among Chinese hypertensive patients, there was a statistically significant positive association between baseline plasma vitamin E and the risk of first stroke in men, but not in women. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT00794885, Identifier: NCT00794885.

6.
Innovation (N Y) ; 2(4): 100176, 2021 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-34806059

RESUMO

The great losses caused by financial fraud have attracted continuous attention from academia, industry, and regulatory agencies. More concerning, the ongoing coronavirus pandemic (COVID-19) unexpectedly shocks the global financial system and accelerates the use of digital financial services, which brings new challenges in effective financial fraud detection. This paper provides a comprehensive overview of intelligent financial fraud detection practices. We analyze the new features of fraud risk caused by the pandemic and review the development of data types used in fraud detection practices from quantitative tabular data to various unstructured data. The evolution of methods in financial fraud detection is summarized, and the emerging Graph Neural Network methods in the post-pandemic era are discussed in particular. Finally, some of the key challenges and potential directions are proposed to provide inspiring information on intelligent financial fraud detection in the future.

7.
Crit Rev Anal Chem ; : 1-14, 2021 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-34802340

RESUMO

Since residual chiral pollutants in the environment and toxic or ineffective chiral components in drugs can threat human health, there is an urgent need for methods to separation and analyze chiral molecules. Molecular imprinting technology (MIT) is a biomimetic technique for specific recognition of analytes with high potential for application in the field of chiral separation and analysis. However, since MIT has some disadvantages when used for chiral recognition, such as poor rigidity of imprinted materials, a single type of recognition site, and poor stereoselectivity, reducing the interference of conformationally and structurally similar substances to increase the efficiency of chiral recognition is difficult. Therefore, improving the rigidity of imprinted materials, increasing the types of imprinted cavity recognition sites, and constructing an imprinted microenvironment for highly selective chiral recognition are necessary for the accurate identification of chiral substances. In this article, the principle of chiral imprinting recognition is introduced, and various strategies that improve the selectivity of chiral imprinting, using derivative functional monomers, supramolecular compounds, chiral assembly materials, and biomolecules, are reviewed in the past 10 years.

8.
Genes Dev ; 2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34819352

RESUMO

Binding of microRNAs (miRNAs) to mRNAs normally results in post-transcriptional repression of gene expression. However, extensive base-pairing between miRNAs and target RNAs can trigger miRNA degradation, a phenomenon called target RNA-directed miRNA degradation (TDMD). Here, we systematically analyzed Argonaute-CLASH (cross-linking, ligation, and sequencing of miRNA-target RNA hybrids) data and identified numerous candidate TDMD triggers, focusing on their ability to induce nontemplated nucleotide addition at the miRNA 3' end. When exogenously expressed in various cell lines, eight triggers induce degradation of corresponding miRNAs. Both the TDMD base-pairing and surrounding sequences are essential for TDMD. CRISPR knockout of endogenous trigger or ZSWIM8, a ubiquitin ligase essential for TDMD, reduced miRNA degradation. Furthermore, degradation of miR-221 and miR-222 by a trigger in BCL2L11, which encodes a proapoptotic protein, enhances apoptosis. Therefore, we uncovered widespread TDMD triggers in target RNAs and demonstrated an example that could functionally cooperate with the encoded protein.

9.
Theranostics ; 11(20): 10125-10147, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34815808

RESUMO

Background: Fibroblast growth factor receptors (FGFRs) are key targets for nerve regeneration and repair. The therapeutic effect of exogenous recombinant FGFs in vivo is limited due to their high molecular weight. Small peptides with low molecular weight, easy diffusion, low immunogenicity, and nontoxic metabolite formation are potential candidates. The present study aimed to develop a novel low-molecular-weight peptide agonist of FGFR to promote nerve injury repair. Methods: Phage display technology was employed to screen peptide ligands targeting FGFR2. The peptide ligand affinity for FGFRs was detected by isothermal titration calorimetry. Structural biology-based computer virtual analysis was used to characterize the interaction between the peptide ligand and FGFR2. The peptide ligand effect on axon growth, regeneration, and behavioral recovery of sensory neurons was determined in the primary culture of sensory neurons and dorsal root ganglia (DRG) explants in vitro and a rat spinal dorsal root injury (DRI) model in vivo. The peptide ligand binding to other membrane receptors was characterized by surface plasmon resonance (SPR) and liquid chromatography-mass spectrometry (LC-MS)/MS. Intracellular signaling pathways primarily affected by the peptide ligand were characterized by phosphoproteomics, and related pathways were verified using specific inhibitors. Results: We identified a novel FGFR-targeting small peptide, CH02, with seven amino acid residues. CH02 activated FGFR signaling through high-affinity binding with the extracellular segment of FGFRs and also had an affinity for several receptor tyrosine kinase (RTK) family members, including VEGFR2. In sensory neurons cultured in vitro, CH02 maintained the survival of neurons and promoted axon growth. Simultaneously, CH02 robustly enhanced nerve regeneration and sensory-motor behavioral recovery after DRI in rats. CH02-induced activation of FGFR signaling promoted nerve regeneration primarily via AKT and ERK signaling downstream of FGFRs. Activation of mTOR downstream of AKT signaling augmented axon growth potential in response to CH02. Conclusion: Our study revealed the significant therapeutic effect of CH02 on strengthening nerve regeneration and suggested a strategy for treating peripheral and central nervous system injuries.

10.
PLoS Comput Biol ; 17(11): e1009594, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34762648

RESUMO

The growing number of next-generation sequencing (NGS) data presents a unique opportunity to study the combined impact of mitochondrial and nuclear-encoded genetic variation in complex disease. Mitochondrial DNA variants and in particular, heteroplasmic variants, are critical for determining human disease severity. While there are approaches for obtaining mitochondrial DNA variants from NGS data, these software do not account for the unique characteristics of mitochondrial genetics and can be inaccurate even for homoplasmic variants. We introduce MitoScape, a novel, big-data, software for extracting mitochondrial DNA sequences from NGS. MitoScape adopts a novel departure from other algorithms by using machine learning to model the unique characteristics of mitochondrial genetics. We also employ a novel approach of using rho-zero (mitochondrial DNA-depleted) data to model nuclear-encoded mitochondrial sequences. We showed that MitoScape produces accurate heteroplasmy estimates using gold-standard mitochondrial DNA data. We provide a comprehensive comparison of the most common tools for obtaining mtDNA variants from NGS and showed that MitoScape had superior performance to compared tools in every statistically category we compared, including false positives and false negatives. By applying MitoScape to common disease examples, we illustrate how MitoScape facilitates important heteroplasmy-disease association discoveries by expanding upon a reported association between hypertrophic cardiomyopathy and mitochondrial haplogroup T in men (adjusted p-value = 0.003). The improved accuracy of mitochondrial DNA variants produced by MitoScape will be instrumental in diagnosing disease in the context of personalized medicine and clinical diagnostics.

11.
J Hum Hypertens ; 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34782738

RESUMO

Little information is available on the association between brachial-ankle pulse wave velocity (baPWV) and the risk of stroke in Chinese H-type hypertension patients. Therefore, our study aimed to assess this association between baseline baPWV and short-term risk of first stroke and to propose a cutoff value of baPWV that could predict near cerebrovascular events. A total of 9787 hypertension patients without preexisting stroke who underwent baPWV measurement were included. The primary end points were first symptomatic stroke. Secondary end points were first ischemic stroke and first hemorrhagic stroke. During a median follow-up of 20.8 months, there was a total of 138 first strokes including 123 first ischemic strokes and 15 first hemorrhagic strokes. When baPWV was categorized in quartiles, the higher risks of first stroke (HR = 1.52; 95% CI: 1.05-2.21) and first ischemic stroke (HR = 1.53; 95% CI: 1.03-2.26) were found in participants in quartile 4 (≥21.31 m/s), compared with those in quartile 1-3 (<21.31 m/s). In receiver operating characteristic curve analysis, the best cutoff value of baPWV that could predict first stroke was 21.43 m/s. Higher baPWV (≥21.43 m/s) was significantly associated with increased risk of first stroke (HR = 1.60; 95% CI: 1.10-2.32) and first ischemic stroke (HR = 1.60; 95% CI: 1.08-2.37). In conclusion, higher baPWV levels were associated with an increased risk of first stroke among Chinese H-type hypertensive patients. In addition, a cutoff value of 21.43 m/s of baPWV was proposed that could predict the next two years' cerebrovascular events.

12.
Oxid Med Cell Longev ; 2021: 3672112, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34777684

RESUMO

Transmembrane protein 206 (TMEM206), a proton-activated chloride channel, has been implicated in various biochemical processes, including bone metabolism, and has emerged as a novel cancer-related protein in multiple tumor types. However, its role in primary malignant bone tumors, particularly in osteosarcoma (OS), remains unclear. This study is aimed at exploring the effects of TMEM206 gene silencing on the proliferation, migration, invasion, and metastasis of human OS cells in vitro and in vivo using an shRNA-knockdown strategy. We found that TMEM206 is frequently overexpressed and that high levels of TMEM206 correlated with clinical stage and pulmonary metastasis in patients with OS. We provided evidence that TMEM206-silenced OS cancer cells exhibit decreased proliferation, migration, and invasion in vitro. Mechanistically, we identified ß-catenin, a key member of Wnt/ß-catenin signaling, as a downstream effector of TMEM206. TMEM206 silencing inhibits the Wnt/ß-catenin signaling pathway in expression rescue experiments, confirming that TMEM206 silencing attenuates OS cell tumorigenic behavior, at least in part, via the ß-catenin mediated downregulation of Wnt/ß-catenin signaling. More importantly, TMEM206 knockdown-related phenotype changes were replicated in a xenograft nude mouse model where pulmonary metastases of OS cells were suppressed. Together, our results demonstrate that silencing TMEM206 negatively modulates the Wnt/ß-catenin signaling pathway via ß-catenin to suppress proliferation, migration, invasion, and metastasis in OS carcinogenesis, suggesting TMEM206 as a potential oncogenic biomarker and a potential target for OS treatment.

13.
Mikrochim Acta ; 188(12): 438, 2021 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-34839414

RESUMO

The rapid detection of insecticides such as parathion-methyl (PM) requires methods with high sensitivities and selectivities. Herein, a dual catalytic amplification strategy was developed using Fe3O4 nanozyme-supported carbon quantum dots and silver terephthalate metal-organic frameworks (Fe3O4/C-dots@Ag-MOFs) as current amplification elements. Based on this strategy, a novel electrochemical microfluidic paper-based chip was designed to detect PM. Fe3O4/C-dots@Ag-MOFs were synthesised by a hydrothermal method, and a molecularly imprinted polymer (MIP) was then synthesised on the surface of Fe3O4/C-dots@Ag-MOFs using PM as a template molecule. Finally, the reaction zone of a chip was modified with MIP/Fe3O4/C-dots@Ag-MOFs. PM from a sample introduced into the reaction zone was captured by the MIP, which generated a reduction current response at - 0.53 V in a three-electrode system embedded in the chip. Simultaneous catalysis by Fe3O4/C-dots and Ag-MOFs significantly enhanced the signal. The chip had a detection limit of 1.16 × 10-11 mol L-1 and was successfully applied to the determination of PM in agricultural products and environmental samples with recovery rates ranging from 82.7 to 109%, with a relative standard deviation (RSD) of less than 5.0%. This approach of combining a dual catalytic amplification strategy with an MIP significantly increased the sensitivity as well as selectivity of chips and can potentially be used to detect a wide variety of target analytes using microfluidic paper-based chips.

14.
Food Funct ; 12(20): 9632-9641, 2021 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-34664577

RESUMO

The purpose of the study was to explore the effect of exopolysaccharides (EPSs) of Lactobacillus rhamnosus GG (LGG) on the antioxidative and antiapoptotic activities of intestinal porcine epithelial cells (IPEC-J2). EPSs exhibited promising antioxidative activities, such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical (˙OH) and superoxide anion radical (O2˙-) scavenging, as well as ferrous ion chelating ability. Moreover, EPSs of LGG could effectively alleviate the IPEC-J2 oxidative damage induced by H2O2 through the Bcl-2-associated (Bax)/B cell lymphoma-2 (Bcl-2) and Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor-erythroid 2-related factor-2 (Nrf2) signaling pathways and up-regulated the intracellular tight junction (TJ)-related proteins. In addition, EPSs significantly improved the survival rates of H2O2-damaged IPEC-J2 cells and had no cytotoxic activity, suggesting that EPSs produced by LGG may be an effective drug for relieving oxidative stress. Our study provided a theoretical basis for exploration of the application of probiotic secondary metabolites in practice.

15.
Artigo em Inglês | MEDLINE | ID: mdl-34691206

RESUMO

Objective: To explore the clinical efficacy of treating endometrial cancer with Xiaoaiping tablets under comprehensive nursing intervention and their effect on quality of life. Methods: The clinical data of 120 endometrial cancer patients treated at the Affiliated Hospital of Southwest Medical University from February 2019 to February 2020 were retrospectively analyzed, and the patients were split into the experimental group and the control group according to their admission order, with 60 cases each. Conventional treatment and Xiaoaiping tablet regimen were received by all patients, those in the control group accepted the general nursing, and those in the experimental group accepted the comprehensive nursing intervention for 12 months, so as to compare their clinical efficacy, quality of life (Functional Assessment of Cancer Therapy, FACT), negative emotion scores (Hospital Anxiety and Depression Scale, HAD), and Medical Coping Modes Questionnaire (MCMQ) scores between the two groups. Results: No statistical differences in the patients' general information between the two groups were observed (P > 0.05); compared with the control group after nursing, the experimental group obtained a significantly higher objective remission rate (80.0%), significantly higher disease control rate (90.0%) (P < 0.05), significantly better QOL (P < 0.001), significantly lower negative emotion scores (P < 0.001), and significantly better MCMQ scores (P < 0.001). Conclusion: Adopting Xiaoaiping tablets under comprehensive nursing intervention can improve the negative emotions of patients with endometrial cancer, enhance their confidence in medical treatment, present better efficacy, and obviously promote their QOL. Therefore, comprehensive nursing intervention should be promoted and applied in practice.

16.
J Cancer ; 12(21): 6383-6392, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34659528

RESUMO

Osteosarcoma is the most common primary bone malignancy, and current chemotherapy sessions against it often induce severe complications in patients. Thus, it is necessary to develop new and effective antineoplastic agents with fewer side effects. Panax notoginseng saponins (PNS) are the active components in panax notoginseng and were reported to be capable of inhibiting the growth of several tumors both in vitro and in vivo. However, its effects on osteosarcoma have not been studied yet, which is addressed in this study for the first time. Our results indicated that PNS can inhibit proliferation, invasion and migration of the osteosarcoma cells, while promoting their apoptosis simultaneously. Specifically, PNS caused an increase in mitochondrial membrane potential and the amount of reactive oxygen species. The cell cycle in osteosarcoma cells was arrested in the G0 / G1 phase after PNS treatment. The expression of p53 and other apoptosis-related mitochondrial proteins were promoted. Nevertheless, it was observed that autophagy became less active in osteosarcoma cells when PNS was administered. In a word, PNS were of potential therapeutic significance for osteosarcoma.

18.
Opt Express ; 29(15): 24182-24192, 2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34614668

RESUMO

We propose a nested U-shape tube anti-resonant hollow core fiber (UARF) that can effectively reduce the confinement loss (CL) as well as the loss oscillations. The key parameters of UARF have been optimized via numerical analysis. Simulation results show that the CL of proposed UARF is lower than 0.01dB/km over a 550 nm operational bandwidth range from 1.3 µm to 1.85 µm. This CL is nearly one order of magnitude lower than the nested anti-resonant nodeless fiber (NANF). Moreover, the loss ratio between higher-order modes to the fundamental mode is verified to be more than 100,000 over a ultrawide bandwidth of 1000 nm, which indicates its excellent single mode performance. The tolerance towards the structure deformation of UARF has been evaluated for the purpose of practical fiber fabrication. Thus, the proposed UARF has potential application in large capacity data transmission, nonlinear optics, gas sensing and so on.

19.
Opt Express ; 29(19): 30473-30482, 2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34614770

RESUMO

We propose and experimentally demonstrate symmetrical (homo-modal) and asymmetrical (hetero-modal) full-duplex bi-directional architectures based on dual-vector eigenmodes multiplexing over a 3 km few mode fiber (FMF). Firstly, 4 vector modes (VMs) of 2 mode groups (MGs), l = 0 (HE11o and HE11e modes) and l = +2 (EH11o and EH11e modes), each carrying a 14 GBaud quadrature phase-shift keying (QPSK) signal, are utilized in the up and down links and a 224 Gb/s same-mode bi-directional transmission is successfully realized. The crosstalk between the VMs in l = 0 and l = +2 of this full-duplex system is less than -13.8 dB. To strengthen the immunity to performance degradation induced by connector reflection and back scattering, we propose an effective approach to mitigate impairments by using hetero-modes on two terminals of the bi-directional system. Then, 2 VMs of l = 0 and 2 VMs of l = +2 are respectively employed in the up and down streams. The channel isolation between the VMs in l = 0 and l = +2 of such full-duplex link is larger than 19 dB, which supports a 448 Gb/s bi-directional transmission with 28 GBaud 16-ary quadrature amplitude modulation (QAM) modulation over a 3 km FMF by using 2 × 2 MIMO. Moreover, mode-wavelength division multiplexing including 2 modes and 4 wavelengths in both up and down streams is implemented in the transmission system. A total capacity of the 1.792 Tb/s link with 28 GBaud 16-QAM signal over each channel is successfully realized over the 3 km FMF. The measured bit-error-ratios (BERs) of all channels are below the 7% hard decision forward error correction (FEC) threshold at 3.8 × 10-3. The experimental results adequately indicate that such a scheme has a great potential in high-speed bi-directional point-to-point (P2P) optical interconnects.

20.
Opt Express ; 29(18): 28190-28201, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34614956

RESUMO

Polarization mode dispersion (PMD) is one of the fundamental properties of a standard single-mode fiber. It affects the propagating signals and degrades the performance of high-speed optical fiber communication systems. PMD also gives an effect on the nonlinear spectra or scattering data in nonlinear frequency division multiplexing (NFDM) systems. However, PMD is usually described in the linear frequency domain, and there are few investigations about the influence of PMD in the nonlinear frequency domain (NFD). An NFD-PMD model is needed to understand the impact of PMD in the NFD. In this work, using a linear approximation method, we first propose an NFD-PMD model and verify its effectiveness. With the guide of the NFD-PMD model, a blind NFD-PMD equalization scheme is designed. The simulation results indicate that the proposed NFD-PMD equalization scheme has better performance than the training sequence method based on linear frequency domain equalization.

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