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We propose and experimentally demonstrate a large-range and seamless rate-adaptive free-space optical (FSO) scheme based on rate compatible modulation (RCM). It utilizes a mapping method through weighted summation, enabling an even increase of bit energy. This allows the system to seamlessly adjust the throughput. In addition, the handover mechanism based on rate check and acknowledgment signals ensures a wide coverage of signal-to-noise ratio (SNR) fluctuation. It is worth noting that this scheme does not require any changes to the mapping matrix and decoding algorithm, making it easier to implement in real-world systems. Simulation proves the superiority of the proposed approach in terms of coding rate coverage by applying a fixed mapping matrix compared to a traditional adaptive modulation and coding scheme. Experimental demonstration over a 50â m FSO link verifies that the SNR dynamic range of this scheme is >15â dB with a seamless rate adjustment between 6.7â Gb/s and 53.6â Gb/s and the operability of RCM is not limited by the time scale of turbulence, revealing huge potential for the massive connections in future smart cities.
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This Letter presents what is to our knowledge a novel approach to reduce the digital signal processing (DSP) complexity in intensity modulation and direct detection (IM/DD) systems, which is critical for short-reach optical communication systems with severe bandwidth limitations. We propose a sub-baud rate sampling reception method utilizing a polyphase feedforward equalizer-based maximum likelihood sequence estimation (PFFE-MLSE), which could operate effectively under a sampling rate of 0.6 samples per symbol. This new architecture eliminates the need for resampling, allowing the adaptive equalizer to operate with significantly reduced complexity-over 60% compared to traditional FFE-MLSE. An offline experiment, transmitting a 100-Gbaud on-off keying (OOK) signal over a 5-km single-mode fiber (SMF) link, demonstrates the feasibility of our approach with bit error ratio (BER) meeting the KP4-forward error correction (KP4-FEC) threshold in the optical back-to-back (OBTB) scenario and 7% hard-decision FEC (HD-FEC) threshold in the 5-km SMF transmission.
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Secure key distribution (SKD) schemes based on fiber channel reciprocity provide information-theoretic security as well as a simple symmetric structure. However, the nonlinear effects and backscattering effects introduced during the bidirectional transmission process degrade the channel reciprocity. Recent unidirectional SKD schemes avoid non-reciprocal factors but require additional negotiation mechanisms to aggregate the transmitter and receiver data. Here, we propose a unidirectional SKD scheme based on channel physical intrinsic property and polarization reciprocity. The designed loopback structure constructs asymmetry between legitimate and illegitimate parties while aggregating data. The deployment of a broadband chaotic entropy source significantly improves the key generation rate (KGR). In the experiment, the KGR reaches 17.5â Gb/s, and the distribution distance reaches 100â km.
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BACKGROUND: To investigate the value of a nomogram model based on the combination of clinical-CT features and multiphasic enhanced CT radiomics for the preoperative prediction of the microsatellite instability (MSI) status in colorectal cancer (CRC) patients. METHODS: A total of 347 patients with a pathological diagnosis of colorectal adenocarcinoma, including 276 microsatellite stabilized (MSS) patients and 71 MSI patients (243 training and 104 testing), were included. Univariate and multivariate regression analyses were used to identify the clinical-CT features of CRC patients linked with MSI status to build a clinical model. Radiomics features were extracted from arterial phase (AP), venous phase (VP), and delayed phase (DP) CT images. Different radiomics models for the single phase and multiphase (three-phase combination) were developed to determine the optimal phase. A nomogram model that combines clinical-CT features and the optimal phasic radscore was also created. RESULTS: Platelet (PLT), systemic immune inflammation index (SII), tumour location, enhancement pattern, and AP contrast ratio (ACR) were independent predictors of MSI status in CRC patients. Among the AP, VP, DP, and three-phase combination models, the three-phase combination model was selected as the best radiomics model. The best MSI prediction efficacy was demonstrated by the nomogram model built from the combination of clinical-CT features and the three-phase combination model, with AUCs of 0.894 and 0.839 in the training and testing datasets, respectively. CONCLUSION: The nomogram model based on the combination of clinical-CT features and three-phase combination radiomics features can be used as an auxiliary tool for the preoperative prediction of the MSI status in CRC patients.
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Neoplasias Colorrectales , Nomogramas , Humanos , Inestabilidad de Microsatélites , Radiómica , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/métodos , Neoplasias Colorrectales/diagnóstico por imagen , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/cirugíaRESUMEN
BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a highly fatal disease with limited effective treatment especially after first-line chemotherapy. The human epidermal growth factor receptor 2 (HER-2) immunohistochemistry (IHC) positive is associated with more aggressive clinical behavior and shorter overall survival in PDAC. CASE SUMMARY: We present a case of multiple metastatic PDAC with IHC mismatch repair proficient but HER-2 IHC weakly positive at diagnosis that didn't have tumor regression after first-line nab-paclitaxel plus gemcitabine and PD-1 inhibitor treatment. A novel combination therapy PRaG 3.0 of RC48 (HER2-antibody-drug conjugate), radiotherapy, PD-1 inhibitor, granulocyte-macrophage colony-stimulating factor and interleukin-2 was then applied as second-line therapy and the patient had confirmed good partial response with progress-free-survival of 6.5 months and overall survival of 14.2 month. She had not developed any grade 2 or above treatment-related adverse events at any point. Percentage of peripheral CD8+Temra and CD4+Temra were increased during first two activation cycles of PRaG 3.0 treatment containing radiotherapy but deceased to the baseline during the maintenance cycles containing no radiotherapy. CONCLUSION: PRaG 3.0 might be a novel strategy for HER2-positive metastatic PDAC patients who failed from previous first-line approach and even PD-1 immunotherapy but needs more data in prospective trials.
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Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Receptor ErbB-2 , Humanos , Femenino , Gemcitabina , Desoxicitidina/uso terapéutico , Estudios Prospectivos , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Paclitaxel/uso terapéutico , Neoplasias Pancreáticas/tratamiento farmacológico , Carcinoma Ductal Pancreático/tratamiento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Albúminas/uso terapéuticoRESUMEN
INTRODUCTION: The PRaG regimen, which consists of hypofractionated radiotherapy combined with a programmed cell death-1/programmed cell death ligand-1 (PD-1/PD-L1) inhibitor and granulocyte-macrophage colony stimulating factor (GM-CSF), has been demonstrated to have a survival benefit in patients with advanced solid tumours who have failed at least two lines of treatment. Nonetheless, lymphopenia poses an impediment to the enduring efficacy of PD-1/PD-L1 inhibitor therapy. Adequate lymphocyte reserves are essential for the efficacy of immunotherapy. Coupling the PRaG regimen with immunomodulatory agents that augment the number and functionality of lymphocytes may yield further survival benefits in this cohort of patients. OBJECTIVE: The aim of this study is to investigate the effectiveness and safety of a meticulously thymalfasin-controlled PRaG regimen in patients with advanced and chemotherapy-resistant solid tumours. METHODS AND ANALYSIS: The study has a prospective, single-arm, open-label, multicentre design and aims to recruit up to 60 patients with histologically confirmed advanced solid tumours that have relapsed or metastasised. All eligible patients will receive a minimum of two cycles of the PRaG regimen comprising thymalfasin followed by maintenance treatment with a PD-1/PD-L1 inhibitor and thymalfasin for 1 year or until disease progression. Patients will be monitored according to the predetermined protocol for a year or until disease progression after initiation of radiotherapy. ETHICS AND DISSEMINATION: The study protocol was approved by the Ethics Committee of the Second Affiliated Hospital of Soochow University, on 25 November 2022 (JD-LK-2022-151-01) and all other participating hospitals. Findings will be disseminated through national and international conferences. We also plan to publish our findings in high-impact peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT05790447.
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Inhibidores de Puntos de Control Inmunológico , Neoplasias , Humanos , Timalfasina/uso terapéutico , Estudios Prospectivos , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Receptor de Muerte Celular Programada 1/uso terapéutico , Neoplasias/tratamiento farmacológico , Progresión de la Enfermedad , Protocolos de Quimioterapia Combinada Antineoplásica , Estudios Multicéntricos como AsuntoRESUMEN
We report a real-time 150 kbps stealth transmission within public optical communication of 10 Gbps dual polarization QPSK. The stealth data is modulated onto the frequency tuning signals of a fast-tuning laser source in the transmitter, which causes slight frequency dithering for the transmitted optical signal. In the receiver, the stealth receiver recovers the stealth data from the estimated frequency offset by the QPSK DSP algorithm. The experiments show the stealth transmission has few impacts on the public channel over a 300â km distance. The proposed method is fully compatible with existing optical transmission systems, and the only hardware change is to upgrade the transmitter laser to support frequency tuning through an external analog port for receiving stealth signal. The proposed stealth scheme can combine with cryptographic protocols to improve the integrated security of the system, and can be used as signaling transport for low level network control to reduce the communication overhead.
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In this Letter, the impact of non-Gaussian noise caused by a nonlinear equalizer on low-density parity-check code (LDPC) performance is investigated in a 25-km 50-Gb/s pulse amplitude modulation4 (PAM4) direct detection system. The lookup table (LUT)-based log-likelihood ratio (LLR) calculation method is proposed to enhance the LDPC performance for the non-Gaussian noise case. Compared to the conventional LLR calculation method based on Gaussian distribution, the proposed method can improve 0.6-dB sensitivity in artificial neural network (ANN) equalizer systems. In addition, the conventional generalized mutual information (GMI) is proven to be an imperfect predictor of LDPC performance after nonlinear equalizers, such as decision feedback equalization (DFE) and ANN equalizer.
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PURPOSE: To investigate the value of preoperative diagnosis of colorectal adenocarcinoma (CRAC) pathological T staging based on dual-layer spectral-detector computed tomography (DLCT) extracellular volume fraction (ECV) of CRAC lesions. METHODS: We prospectively collected clinical and DLCT imaging data from 165 patients with CRAC who attended two hospitals from June 2022 to April 2023. The enrolled patients were divided into a training group (n = 110, from Hospital 1) and an external validation group (n = 55, from Hospital 2). Measuring and calculating DLCT parameters of lesions, including CT values of 40 and 100 keV virtual mono-energetic images (VMI), iodine concentration (IC) and effective atomic number (Eff-Z) in the arterial phases (AP) and venous phases (VP), and ECV in the delayed phase (DP). The differences in clinical characteristics and DLCT parameters were compared between different pT subgroups. The correlation between DLCT parameters and pT stages were evaluated by Spearman correlation analysis. A multifactorial binary logistic stepwise forward regression analysis was performed to obtain independent influences associated with pT stage. Receiver operating characteristic curves (ROCs) were used to assess diagnostic efficacy and were expressed as area under the curve (AUC). RESULTS: Each DLCT parameter was higher in pT3 stage tumors than in pT1-2 stage tumors (all P < 0.05). The highest correlation was found between ECV and pT stage (r = 0.637). ECV were independent influences associated with pT stage. ECV had excellent diagnostic efficacy for CRAC pT staging in both the training and external validation groups (AUC = 0.919 and 0.892). CONCLUSION: ECV based on DLCT measurement can be used for preoperative noninvasive diagnosis of CRAC pT staging with excellent diagnostic efficacy. It can provide a new imaging marker for the preoperative evaluation of CRAC and help clinicians formulate individualized treatment earlier. However, it needs to be confirmed with a larger sample size.
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Adenocarcinoma , Neoplasias Colorrectales , Estadificación de Neoplasias , Tomografía Computarizada por Rayos X , Humanos , Masculino , Femenino , Persona de Mediana Edad , Neoplasias Colorrectales/diagnóstico por imagen , Neoplasias Colorrectales/patología , Adenocarcinoma/diagnóstico por imagen , Adenocarcinoma/patología , Anciano , Tomografía Computarizada por Rayos X/métodos , Estudios Prospectivos , Adulto , Anciano de 80 o más AñosRESUMEN
Background: It remains undetermined whether preoperative computed tomography (CT)-guided hookwire localization would result in elevated risk of tumor spread through air spaces (STAS) in stage IA lung adenocarcinoma. Methods: A total of 1836 patients who underwent lobectomy were included. To eliminate the potential impact of confounding factors on producing STAS, propensity score-matching (PSM) was used to create two balanced subgroups stratified by implementation of hookwire localization. We also introduced an external cohort including 1486 patients to explore the effect of hookwire localization on the incidence of STAS and patient survival after sublobar resection (SR). For proactive simulation of hookwire localization, 20 consecutive lobectomy specimens of p-stage IA lung adenocarcinoma were selected. Results: Ex vivo tests revealed that mechanical artifacts presenting as spreading through a localizer surface (STALS) could be induced by hookwire localization but be distinguished by CD68 and AE1/3 antibody-based immunohistochemistry. The distance of STALS dissemination tended to be shorter compared with real STAS (P = 0.000). After PSM, implementation of hookwire localization was not associated with elevated STAS incidence, nor worse survival in p-stage IA patients undergoing lobectomy irrespective of STAS. Conclusions: CT-guided hookwire localization might induce mechanical artifacts presenting as STALS which could be distinguished by immunohistochemistry, but would not affect survival in p-stage IA disease. Surgeons can be less apprehensive about performing hookwire localization in relation to STAS on stage IA disease suitable for SR.
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Lysophosphatidic acid (LPA) is a bioactive phospholipid that plays a crucial role in cardiovascular diseases. Here, we question whether LPA contributes to myocardial ischemia/reperfusion (I/R) injury by acting on transient receptor potential vanilloid 1 (TRPV1) in spinal cord. By ligating the left coronary artery to establish an in vivo I/R mouse model, we observed a 1.57-fold increase in LPA level in the cerebrospinal fluid (CSF). The I/R-elevated CSF LPA levels were reduced by HA130, an LPA synthesis inhibitor, compared to vehicle treatment (4.74 ± 0.34 vs. 6.46 ± 0.94 µg/mL, p = 0.0014). Myocardial infarct size was reduced by HA130 treatment compared to the vehicle group (26 ± 8% vs. 46 ± 8%, p = 0.0001). To block the interaction of LPA with TRPV1 at the K710 site, we generated a K710N knock-in mouse model. The TRPV1K710N mice were resistant to LPA-induced myocardial injury, showing a smaller infarct size relative to TRPV1WT mice (28 ± 4% vs. 60 ± 7%, p < 0.0001). Additionally, a sequence-specific TRPV1 peptide targeting the K710 region produced similar protective effects against LPA-induced myocardial injury. Blocking the K710 region through K710N mutation or TRPV1 peptide resulted in reduced neuropeptides release and decreased activity of cardiac sensory neurons, leading to a decrease in cardiac norepinephrine concentration and the restoration of intramyocardial pro-survival signaling, namely protein kinase B/extracellular regulated kinase/glycogen synthase kinase-3ß pathway. These findings suggest that the elevation of CSF LPA is strongly associated with myocardial I/R injury. Moreover, inhibiting the interaction of LPA with TRPV1 by blocking the K710 region uncovers a novel strategy for preventing myocardial ischemic injury.
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Lisofosfolípidos , Daño por Reperfusión Miocárdica , Ratones , Animales , Daño por Reperfusión Miocárdica/prevención & control , Canales Catiónicos TRPV/genética , Péptidos/metabolismo , Médula Espinal/metabolismoRESUMEN
BACKGROUND: Cervical cancer (CC) remains a significant clinical challenge, even though its fatality rate has been declining in recent years. Particularly in developing countries, the prognosis for CC patients continues to be suboptimal despite numerous therapeutic advances. METHODS: Using The Cancer Genome Atlas database, we extracted CC-related data. From this, 52 methylation-related genes (MRGs) were identified, leading to the selection of a 10 long non-coding RNA (lncRNA) signature co-expressed with these MRGs. R programming was employed to filter out the methylation-associated lncRNAs. Through univariate, least absolute shrinkage and selection operator (i.e. LASSO) and multivariate Cox regression analysis, an MRG-associated lncRNA model was constructed. The established risk model was further assessed via the Kaplan-Meier method, principal component analysis, functional enrichment annotation and a nomogram. Furthermore, we explored the potential of this model with respect to guiding immune therapeutic interventions and predicting drug sensitivities. RESULTS: The derived 10-lncRNA signature, linked with MRGs, emerged as an independent prognostic factor. Segmenting patients based on their immunotherapy responses allowed for enhanced differentiation between patient subsets. Lastly, we highlighted potential compounds for distinguishing CC subtypes. CONCLUSIONS: The risk model, associated with MRG-linked lncRNA, holds promise in forecasting clinical outcomes and gauging the efficacy of immunotherapies for CC patients.
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Adenina/análogos & derivados , ARN Largo no Codificante , Neoplasias del Cuello Uterino , Humanos , Femenino , Pronóstico , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/terapia , ARN Largo no Codificante/genética , InmunoterapiaRESUMEN
BACKGROUND: Lung adenocarcinoma accounts for approximately 40% of lung cancer cases and poses a serious threat to human health. Therefore, there is an urgent need to identify central biomarkers in lung adenocarcinoma. METHODS: We first identified the EMT-associated genes in LUAD based on the TCGA cohort. Then we screened these 90 EMT-associated genes using univariate Cox regression analysis and LASSO regression analysis to develop a prognostic gene signature in the training set. The predictive performance of the gene signature was assessed in the validation set and multiple external test sets using the ROC cure, C index and log-rank tests. RT-PCR, western blot, wound healing assays, and siRNA methods were further used to investigate the role of PLEK2 in tumor behaviors. RESULTS: Eight genes (CCNB1, PLEK2, DERL3, C1QTNF6, DLGAP5, HMMR, GJB3, and SPOCK1) were eventually selected to develop an eight-gene signature. The 5-year AUC of the gene signature has a robust predictive ability both for predicting overall survival (0.774, 0.756, and 0.669 in the external test sets, respectively), and for progression free survival (0.774, 0.746, and 0.755 in the external test sets, respectively). C-index of the gene signature was 0.961 ± 0.005, 0.916 ± 0.011, and 0.868 ± 0.234 in the external test sets, respectively. Four genes (C1QTNF6, DLGAP5, HMMR, and PLEK2) were identified as key genes in LUAD progression, which were upregulated in the cancerous tissue compared with in the normal tissue (P < 0.001), and correlated with an unwanted prognosis in lung cancer (P < 0.05). PLEK2 was used as an example to explore its effect on LUAD progression in vitro using RT-PCR, western blot, CCK8, si-RNA and wound healing assay. Silencing of PLEK2 was shown to reduce proliferative and migrated ability of lung cancer cells via prohibition of autophagy. CONCLUSIONS: This study developed a novel EMT-related gene signature benefiting precision medicine, and identified four pivotal genes which can serve as therapeutic targets in LUAD. Four key genes can serve as molecular targets for patients with LUAD; silencing of PLEK2 was shown to reduce proliferative and migrated ability of lung cancer cells via prohibition of autophagy.
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Adenocarcinoma del Pulmón , Neoplasias Pulmonares , Humanos , Transición Epitelial-Mesenquimal/genética , Adenocarcinoma del Pulmón/genética , Neoplasias Pulmonares/genética , Biomarcadores , Biología Computacional , Pronóstico , Proteoglicanos , Proteínas de la MembranaRESUMEN
The increasing demand of real-time applications poses a huge challenge to building next-generation radio access network (NG-RAN) with higher stability and lower system complexity. Parallel signal detection (PSD), which aggregates signals of different intermediate frequencies (IFs) on different wavelengths with a single photodiode (PD), becomes a promising candidate for uplink mobile fronthaul with the advantage of low-latency. However, high requirements on the transmitters inhibit the large-scale deployment of radio units (RU). In this paper, we propose an economical, low-latency, multipoint-to-point (MP2P) uplink fronthaul architecture capable of aggregating four end-users with commercial 25G-class optical modules and a single PD. With delta-sigma modulation (DSM), commercial off-the-shelf optical modules can replace analog transmitters in traditional systems. As a demonstration, we aggregated 4 × 380.16-MHz 5â G new radio (NR) orthogonal frequency division multiplexing (OFDM) signals in an IF band with a fixed interval of 400â MHz over 20â km fiber with 4 users.
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In recent years, the transmission capacity of chaotic secure communications has been greatly expanded by combining coherent detection and multi-dimensional multiplexing. However, demonstrations over 1000â km fiber are yet to be further explored. In this paper, we propose a coherent optical secure transmission system based on analog-digital hybrid chaos. By introducing an analog-digital converter (ADC) and a bit extraction into the feedback loop of entropy source, the broadband analog chaos is converted into a binary digital signal. This binary digital signal is then mapped to a 65536-level pulse amplitude modulation (PAM) signal and injected into the semiconductor laser (SL) to regenerate the analog chaos, forming a closed loop. The binary digital signal from the chaos source and the encrypted signal are transmitted via wavelength division multiplexing (WDM). By using conventional digital signal processing (DSP) algorithms and neural networks for post-compensation, long-haul high-quality chaotic synchronization and high-performance secure communication are achieved. In addition, the probability density distribution of the analog chaotic signal is effectively improved by adopting the additional higher-order mapping operation in the digital part of the chaos source. The proof-of-concept experimental results show that our proposed scheme can support the secure transmission of 100 Gb/s quadrature phase shift keying (QPSK) signals over 1000â km of standard single-mode fiber (SSMF). The decrypted bit error rate (BER) reaches 9.88 × 10-4, which is well below the 7% forward error correction (FEC) threshold (BER = 3.8 × 10-3). This research provides a potential solution for high-capacity long-haul chaotic optical communications and fills the gap in secure communications based on analog-digital hybrid chaos.
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Background: Brain metastases (BMs) are the most common central nervous system (CNS) malignant tumors, with rapid disease progression and extremely poor prognosis. The heterogeneity between primary lung cancers and BMs leads to the divergent efficacy of the adjuvant therapy response to primary tumors and BMs. However, the extent of heterogeneity between primary lung cancers and BMs, and the evolutionary process remains little known. Methods: To deeply insight into the extent of inter-tumor heterogeneity at a single-patient level and the process of these evolutions, we retrospectively analyzed a total of 26 tumor samples from 10 patients with matched primary lung cancers and BMs. One patient underwent four times brain metastatic lesion surgery with diverse locations and one operation for the primary lesion. The genomic and immune heterogeneity between primary lung cancers and BMs were evaluated by utilizing whole-exome sequencing (WESeq) and immunohistochemical analysis. Results: In addition to inheriting genomic phenotype and molecular phenotype from the primary lung cancers, massive unique genomic phenotype and molecular phenotype were also observed in BMs, which revealed unimaginable complexity of tumor evolution and extensive heterogeneity among lesions at a single-patient level. By analysis of a multi-metastases case (Case 3) of cancer cells' subclonal composition, we found similar multiple subclonal clusters in the four spatial and temporal isolated brain metastatic focus, with the characteristics of polyclonal dissemination. Our study also verified that the expression level of immune checkpoints-related molecule Programmed Death-Ligand 1 (PD-L1) (P = 0.0002) and the density of tumor-infiltrating lymphocytes (TILs) (P = 0.0248) in BMs were significantly lower than that in paired primary lung cancers. Additionally, tumor microvascular density (MVD) also differed between primary tumors and paired BMs, indicating that temporal and spatial diversity profoundly contributes to the evolution of BMs heterogeneity. Conclusion: Our study revealed the significance of temporal and spatial factors to the evolution of tumor heterogeneity by multi-dimensional analysis of matched primary lung cancers and BMs, which also provided novel insight for formulating individualized treatment strategies for BMs.
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The physical layer transmission security is a promising technology against security threats. As an effective supplement to the encryption strategy, steganography has received widespread attention. We report a real-time 2 kbps stealth transmission in the 10 Gbps dual polarization QPSK public optical communication. The stealth data is embedded in dither signals via precise and stable bias control technique for a Mach-Zehnder modulator. In the receiver, the stealth data can be recovered from the normal transmission signals by low SNR signal processing and digital down conversion. The stealth transmission has been verified to pose almost no impact on the public channel over a 117 km distance. The proposed scheme is compatible with existing optical transmission systems, so that no new hardware needs to be employed. It can be accomplished and is exceeded economically by adding simple algorithms, which utilizes only a small amount of FPGA resources. The proposed method can cooperate with encryption strategies or cryptographic protocols at different network layers to reduce the communication overhead and improve the overall security of the system.
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Maximum likelihood sequence estimation (MLSE) is the optimal signal sequence detection that can remove the inter-symbol interference (ISI). However, we find that the MLSE causes burst consecutive errors alternating between +2 and -2 in M-ary pulse amplitude modulation (PAM-M) IM/DD systems with large ISI. In this paper, we propose to use precoding to suppress the burst consecutive errors resulted from MLSE. A 2 M modulo operation is employed to guarantee that the probability distribution as well as the peak-to-average power ratio (PAPR) of encoded signal remain unchanged. After the receiver-side MLSE, the decoding process that involves adding the current MLSE output to the previous one and applying a 2 M modulo is implemented to break the burst consecutive errors. We conduct experiments to transmit 112/150-Gb/s PAM-4 or beyond 200-Gb/s PAM-8 signals at C-band to investigate the performance of the proposed MLSE integrated with precoding. The results show that the precoding can break burst errors effectively. For 201-Gb/s PAM-8 signal transmission, the precoding MLSE can achieve 1.4-dB receiver sensitivity gain and reduce the maximum length of burst consecutive errors from 16 to 3.
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Due to the cross phase modulation (XPM) effect, in long-haul high-speed dense wavelength division multiplexing (DWDM) coherent systems, using a low-speed on-off-keying (OOK) format optical supervisory channel (OSC) will introduce extra nonlinear phase noise, which restricts the transmission distance. In this paper, we propose a simple OSC coding method to mitigate the OSC-induced nonlinear phase noise. According to the split-step solution of the Manakov equation, we up-convert the baseband of the OSC signal out of the pass-band of the walk-off term to reduce the spectrum density of XPM phase noise. Experimental results show that the optical signal to noise ratio (OSNR) budget on the 400â G channel of 1280-km transmission is improved by 0.96â dB, which achieves almost the same performance with the no OSC case.
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AIMS: We investigated the clinical implications and molecular features of TLS in stage I lung adenocarcinoma (LUAD). METHODS: We retrospectively reviewed the clinicopathological characteristics of 540 patients with p-stage I LUAD. Logistic regression analysis was applied to determining the relationships between clinicopathological features and the presence of TLS. TLS-associated immune infiltration pattern and signature genes were characterized using the transcriptomic profiles of 511 LUADs from The Cancer Genome Atlas (TCGA) database. RESULTS: The presence of TLS was associated with a higher pT stage, low- and middle-grade patterns, and the absence of tumor spreading through air spaces (STAS) and subsolid nodules. Multivariate Cox regression analysis identified that the presence of TLS was associated with favorable overall survival (OS) (p < 0.001) and recurrence-free survival (RFS) (p < 0.001). Subgroup analysis showed that the most favorable OS (p < 0.001) and RFS (p < 0.001) favored the TLS + PD-1- subgroup. The presence of TLS was characterized by abundance in antitumor immunocytes including activated CD8+ T and B cells as well as dentritic cells in TCGA cohort. CONCLUSION: The presence of TLS was an independent favorable factor for patients with stage I LUAD. The presence TLS was featured by special immune profiles which might aid oncologists in determining personalized adjuvant treatment.