Search

Objectives: To compare the diagnostic value of histogram analysis derived from diffusion weighted imaging (DWI) and diffusion kurtosis imaging (DKI) in differentiating the mismatch repair (MMR) status of rectal adenocarcinoma. Methods: DWI and DKI were performed in 124 patients with rectal adenocarcinoma, which were divided into deficient mismatch repair (dMMR) group and proficient mismatch repair (pMMR) group. The patients' general clinical information, pathology and image characteristics were compared. The histogram analysis of apparent diffusion coefficient (ADC), diffusion kurtosis (K) and diffusion coefficient (D)derived from DWI and DKI at b values of 1000 and 2000 s/mm2 were calculated. The diagnostic efficacy of quantitative parameters for MMR in rectal adenocarcinoma was compared. Results: The mean, 50th, 75th and 90th in ADC quantitative parameters of dMMR group were lower when the b value was 2000 s/mm2 (all P

Abstract 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.

Abstract Data security is a key feature of future communications networks. Physical layer introduces rich physical mechanisms to increase the complexity of deciphering and provides extensive protection, but faces challenges in compatibility with commercial systems. Quantum noise stream cipher (QNSC) has been proposed as a promising solution to overcome this problem by fusing the stream cryptography regime with the quantum noise masking physical mechanism. However, it has limitations in terms of digital to analog conversion and clock data synchronization of ultra-high-order ciphertext as well as flexible control of masking noise. Here we report a 147.9-Gbps device-compatible quadrature amplitude modulation (QAM) QNSC secure scheme over 75-km fiber. Thanks to delta-sigma modulator, the transmission of 220 × 220-order QAM-QNSC signal are established through the low-order digital signal. We develop a theoretical model for flexibly regulating the transmission rate and security performance. Broadband optical chaos introduces true randomness and acts on the masking noise.

To counter heterodyne measurements, correlation attacks, and known plaintext attacks, seed key refresh is critical to the security of a quantum noise stream cipher system. Integrated key distribution is an important means to reduce the deployment cost, as key exchange and public transmission are performed over the same channel. In this paper, we propose a novel method for integrated key distribution by optical steganography based on dither-remodulation in a bias controller of the Mach-Zehnder modulator. No extra wavelength or bandwidth is used for the stealth channel, which is transmitted together within the public channel. The concealing depth of the stealth signal reaches −36.2 dB, and its steganographic effect provides additional security, which further improves the overall security of the optical physical layer. The bidirectional stealth transmission can support light-weight temporary key exchange mechanism, combined with asymmetric encryption algorithm, to achieve high security and forward/backward security of seed keys. We experimentally demonstrate a real-time integrated key distribution via optical steganography in a QNSC system. The experimental results show that a real-time bidirectional stealth link is established at a rate of 1 kbps in a fiber transmission distance of 97 km for a public QNSC transmission at a rate of 32 Gbps, providing a seed key refresh frequency of over 1 Hz.

The Mach-Zehnder modulator (MZM) is widely used in high-speed optical communication, and the stability of its bias point is the key to maintain the performance of the communication system. Numerous automatic bias control methods have been proposed to stabilize the bias point, which can be classified into power-based and dither-based methods. The power-based method features low-complexity and is considered of low-precision, thus it is usually applied to low-order modulation. In contrast, dither-based method features high-complexity and is considered of high-precision, therefore it is usually applied to high-order modulation. This paper explores the bias impact mechanism and analyzes the impact of the bias and dither signal. Traditional view is that the performance of dither-based outperforms power-based ones. However, the impact of dither is ignored. Here we compare the performance of the power-based and dither-based method under fair conditions. The results show that the power-based method has higher SNR and better performance taking into account the impact of dither, which indicates that practically it is more suitable for high-order modulation.

Satellite optical communication networks have become a promising core network structure, surpassing 5G and 6G, and are expected to realize seamless connections between terrestrial and non-terrestrial networks. Constructing an optical satellite network that can achieve various link schemes and enable bidirectional communication with multiple optical satellites at a low cost (including low power consumption, low weight, and low space occupation for each satellite) poses a technical challenge. In this paper, we propose and establish a multi-format/rate-tunable integrated laser communications hardware platform that can switch between different links by controlling the modulation format and rate. The platform supports OOK, QPSK, and BPSK modulation with rates ranging from 0.625 to 10 Gbps. Experimental demonstration of bidirectional communication is conducted over a free-space optical link. At a distance of 510 meters, sensitivity tests are conducted for signals with various modulation formats and rates. The receiving sensitivity at the 3.8e-3 FEC threshold is −46 dBm for 10 Gbps PDM-QPSK signal, and is −58 dBm for 625 Mbps BPSK signal. Results show excellent signal sensitivity across different formats and rates. Additionally, the platform is capable of performing ranging while communicating with a minimal ranging error of 2.9% of the width of a code word.

Data center interconnections are cost-sensitive. We propose and demonstrate a cost-effective C-band intensity modulation direct detection (IM/DD) transmitter for extended range (ER) inter-datacenter interconnects utilizing only a 2-bit digital-to-analog converter (DAC). Tomlinson-Harashima precoding (THP) is used in transmitter DSP to compensate for dispersion-induced impairments. Due to the uniform distribution of signal levels after THP encoding, a high-resolution DAC is required to generate electrical signals. The hardware cost of the transmitter can be significantly reduced by compressing the physical number of bits (PNOB) of the DAC to 2 bits. We quantize the signal to 4 levels and utilize up-sampling and noise shaping to greatly reduce the in-band quantization noise. The in-band signal to noise ratio (SNR) can be increased to 23 dB. We experimentally demonstrate a cost-effective 40-Gbaud probabilistic shaping PAM-4 C-band IM/DD transmission over 50-km utilizing only a 2-bit DAC in the transmitter without any optical dispersion compensation. The performance of the proposed scheme is proximate to the common case of using an 8-bit DAC. It has a BER gap of about 2 × 10−3 only when the received optical power (ROP) is higher than −6 dBm.

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.

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.

Abstract 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

In free space optical (FSO) communication, acquisition, tracking and pointing (ATP) is the key technology to maintain a high-quality FSO link. Specifically, the detection of pointing angle deviation greatly affects the performance of ATP, especially under weak receiving power. However, the separated beacon laser beam commonly used in ATP will increase the structural complexity of the terminal such as the size, weight, and power. It is unwanted in some limited applications such as satellite. To improve the pointing accuracy with weak signal in beaconless FSO communication, we propose a delta-sigma enabled beaconless cross-correlation (CCR) method with four-quadrant detectors. In the proposed method, a low-frequency sine analog signal for CCR calculation is modulated into a 1-bit digital signal by delta-sigma modulation and then inserted into the communication data as a training sequence. The root means square error (RMSE) of the pointing angle deviation measurement is 14.17 μrad with the incident optical power of −40 dBm. Compared with the direct intensity method, of which RMSE is 67.61 μrad, the proposed method can effectively improve the pointing accuracy with weak power without a beacon laser in FSO communication.

BackgroundBrain 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.MethodsTo 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.ResultsIn 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.ConclusionOur 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.

Abstract Background The incidence and mortality rate of rectal cancer are still high, the metastasis of rectal cancer are main causes of death. The control of the distant metastasis is one of the main concerns in the treatment of locally advanced rectal cancer, but there are few studies on predicting synchronous distant metastasis (SDM) of rectal cancer. Method The data of patients with rectal adenocarcinoma confirmed by endoscopic biopsy or postoperative pathology from September 2015 to May 2020 in hospital A (center 1) and hospital B (center 2) were analyzed retrospectively, including age, sex, carcinoembryonic antigen, carbohydrate antigen 19–9, tumor location, tumor length, image staging and characteristics. The average age of the 169 patients consisting of 105 males and 64 females in study is 61.2 years. All patients underwent rectal routine rectal MRI, DKI and IVIM examinations on a 3.0-T scanner. Two radiologists sketched regions of interest (ROIs) on b = 1000 s/mm2 DKI and IVIM images to obtain quantitative parameters with FireVoxel manually. We evaluated the difference of histogram analysis, clinical and image data between SDM group and non-SDM group, and evaluated the efficacy of each index in predicting SDM of rectal cancer. Results The 90th percentile of f values in the SDM group is lower than that in the non-SDM group (29.4 ± 8.4% vs. 35 ± 17.8%, P = 0.005). CA19-9 in the SDM group is higher than that in the non-SDM group (P = 0.003). Low and high rectal cancer are more likely to develop SDM than middle rectal cancer (P = 0.05 and P = 0.047). The combination of these three indexes has a greater area under the curve (AUC) than any one index (0.801 vs. 0.685 (f (90th percentile)) and 0.627 (CA19-9), P = 0.0075 and 0.0058, respectively), and its specificity and sensitivity are 80.0% and 71.6%, respectively. When this combination is incorporated into the predictive nomogram model, the c-index is 0.801 (95% confidence interval (CI): 0.730–0.871). Conclusions IVIM quantitative parameters combine with CA19-9 and tumor location can better predict the risk of SDM of rectal cancer.

Internet of everything is being build up rapidly, which causes much higher requirements towards the flexibility of communication resources, especially the adaptivity of the fronthaul to various transmission distances and capacities. In this paper, we proposed a low-cost and spectrum efficient 5G fronthaul broadband connection solution that combines hierarchical modulation technology and delta-sigma modulation. The proposed scheme can double the number of accesses without occupying extra wavelengths. Moreover, such architecture can flexibly allocate the SNR of a group of remote radio units for different user requirement of transmission rate and reaches. Simulation results show that the proposed scheme can increase the access distance of the fronthaul network by 23% and the capacity by 16.7%. The feasibility of the solution is verified through a proof-of-concept experiment. After 20 km transmission, the OFDM-64QAM and -256QAM signal with a center frequency of 3.5 GHz and a bandwidth of 500 MHz can meet the EVM requirements of 8% and 3.5%, respectively. And when the ${R_{LM}}$ of the hierarchical PAM4 signal is 0.6, the ROP required by the most-significant bit branch can be reduced by ∼1.5 dB.

For the fronthaul link in the fifth-generation (5G) wireless networks, optical fiber is one of the most widely used medium, owing to its large bandwidth and low transmission loss. However, in some scenarios, especially the dense urban areas, the installation of fiber optic cables is costly and difficult to establish. Alternatively, the free space optical (FSO) link can be installed easily and spans complex terrain. In this context, we propose and experimentally demonstrate a hybrid FSO/Wireless transmission system based on bandpass delta-sigma modulator and real-time coherent transponder. Advantage of the proposed technique is twofold. Firstly, coherent detection is applied to improve the system sensitivity compared to conventional direct detection. Secondly, delta-sigma modulation (DSM) is utilized to greatly simplify the wireless transmitters and to enhance the bandwidth flexibility. Over a 50-m FSO and 1-m wireless link, a 64-QAM wireless signal at 1 GHz with 500 MHz bandwidth is successfully transmitted. With 16 wavelength division multiplexing channels, the total throughput of the system is up to 24 Gb/s. Meanwhile, the error vector magnitude (EVM) of all channels is around 2.68% and 6.51%, which are demonstrated after FSO and FSO/Wireless transmission, respectively. The results meet the requirement of the third-generation partnership project release 15 with EVM value of 8% for 64-QAM. Moreover, sensitivity of the real-time coherent receiver is lower than −48 dBm under the 7% forward error correction limit with bit error rate of 3.8e-3.

Neurotrophic tyrosine receptor kinase (NTRK) rearrangements are oncogenic drivers of various types of adult and pediatric tumors, including gliomas. However, NTRK rearrangements are extremely rare in glioneuronal tumors. Here, we report a novel NTRK2 rearrangement in a 24-year-old female with dysembryoplastic neuroepithelial tumor (DNT), a circumscribed WHO grade I benign tumor associated with epilepsy. By utilizing targeted RNA next-generation sequencing (NGS), fluorescence in situ hybridization (FISH), reverse transcriptase PCR (RT-PCR), and Sanger sequencing, we verified an in-frame fusion between NTRK2 and the lipoma HMGIC fusion partner-like 3 (LHFPL3). This oncogenic gene rearrangement involves 5’ LHFPL3 and 3’ NTRK2, retaining the entire tyrosine kinase domain of NTRK2 genes. Moreover, the targeted DNA NGS analysis revealed an IDH1 (p.R132H) mutation, a surprising finding in this type of tumor. The pathogenic mechanism of the LHFPL3::NTRK2 in this case likely involves aberrant dimerization and constitutive activation of RTK signaling pathways.