Thin-film lithium niobate-based electro-optic comb cloning for self-homodyne coherent communication.

As the optical communication industry advances, metropolitan area networks (MANs) and radio access networks (RANs) are extensively deployed on a large scale, demanding energy-efficient integrated light sources and simplified digital signal processing (DSP) technologies. The emergence of thin-film lithium niobate (TFLN) has given rise to high-performance, energy-efficient on-chip modulators, making on-chip optical frequency comb (OFC) more appealing. Owing to the phase uniformity and stability of this chip-scale device, it has been possible to eliminate the carrier frequency phase estimation (CPE) in DSP stacks using comb-clone-enabled self-homodyne detection. Here we report the first use, to our knowledge, of a TFLN on-chip electro-optic (EO) frequency comb to realize comb cloning and self-homodyne coherent detection. We transmit three optical pilot tones and eight data channels encoded with 20 Gbaud polarization-multiplexed 16-ary quadrature amplitude modulation (PM-16-QAM) over 10 km and 80 km standard single-mode fibers. The bit error ratios (BERs) of the eight channels reach below 10-3, a result made possible by our on-chip comb. The scalability and mass producibility of on-chip EO combs, combined with the simplified DSP, show potential in our proposed fifth-generation (5G) RAN and MAN transmission scheme.

Broadband ASE source-enabled self-homodyne DA-RoF fronthaul using cascaded SOAs and a multicore fiber.

Broadband amplified spontaneous emission (ASE) light sources are recognized for their cost-effective generation. However, their inherent high-intensity noise and the stringent requirement for time delay matching limits their widespread application in coherent optical telecommunication. Here we propose a broadband ASE source-enabled digital-analog radio-over-fiber (DA-RoF) mobile fronthaul architecture, leveraging semiconductor optical amplifiers (SOAs) and multicore fiber in tandem. Our proposed system uses SOAs to suppress the intensity noise of the ASE carrier and transmits the DA-RoF signal alongside an unmodulated carrier through distinct cores of an 8-core, 1-km fiber. This setup significantly enhances the signal-to-noise ratio (SNR) by 19.4 dB, boosts capacity, and enables self-homodyne detection at the receiver end. We achieve an aggregated bandwidth of 35 GHz (7 cores × 5 GHz), supporting a 2.05-Tb/s CPRI-equivalent data rate with 1024-ary quadrature-amplitude-modulated (1024-QAM) signals. Additionally, we analyze the impact of chromatic dispersion on signal-to-noise ratio for broadband source coherent detection systems. This innovative scheme offers a pragmatic solution for integrating low-cost broadband sources into cost-sensitive fronthaul systems, providing both high capacity and fidelity in massive deployment scenarios.

Low-phase-noise microwave generation with a free-running dual-pumped Si3N4 soliton microcomb.

Microwave signals can be generated by photodetecting the repetition frequencies of the soliton microcombs. In comparison to other methods, the dual-pumped method allows for the stable generation of the soliton microcombs even with resonators having lower Q-factors. However, introducing an additional pump laser may affect the phase noise of the generated microwave signals when using these dual-pumped soliton microcombs. Here, we investigate the factors that could influence the phase noise of microwave signals generated with dual-pumped soliton microcombs, including the polarization, amplitude noise, and phase noise of the two pumps. We demonstrate a 25.25 (12.63) GHz microwave with phase noise reaching -112(-118) dBc/Hz at a 10 kHz offset frequency, surpassing the performance of previous reports on microwave generation using free-running Si3N4 soliton microcombs, even those generated with higher Q microresonators. We analyze the noise floor of the generated microwave signals and establish a phase noise simulation model to study the limiting factors in our system. Our work highlights the potential of generating low-phase-noise microwave signals using free-running dual-pumped soliton microcombs.

Massively parallel FMCW lidar with cm range resolution using an electro-optic frequency comb.

Frequency-modulated continuous wave (FMCW) light detection and ranging (lidar) is a promising solution for three-dimensional (3D) imaging and autonomous driving. This technique maps range and velocity measurement to frequency counting via coherent detection. Compared with single-channel FMCW lidar, multi-channel FMCW lidar can greatly improve the measurement rate. A chip-scale soliton micro-comb is currently used in FMCW lidar to enable multi-channel parallel ranging and significantly increase the measurement rate. However, its range resolution is limited due to the soliton comb having only a few-GHz frequency sweep bandwidth. To overcome this limitation, we propose using a cascaded modulator electro-optic (EO) frequency comb for massively parallel FMCW lidar. We demonstrate a 31-channel FMCW lidar with a bulk EO frequency comb and a 19-channel FMCW lidar using an integrated thin-film lithium niobate (TFLN) EO frequency comb. Both systems have a sweep bandwidth of up to 15 GHz for each channel, corresponding to a 1-cm range resolution. We also analyze the limiting factors of the sweep bandwidth in 3D imaging and perform 3D imaging for a specific target. The measurement rate achieved is over 12 megapixels per second, which verifies its feasibility for massively parallel ranging. Our approach has the potential to greatly benefit 3D imaging in fields where high range resolution is required, such as in criminal investigation and precision machining.

Differential expression analysis of sugar accumulation-related genes during chestnut nut development.

The chestnuts of Castanea mollissima Bl. are an important food crop in China, and have high nutritional content. To understand the pattern of sugar accumulation during chestnut nut development, the related enzyme gene regulatory pathways, and the molecular regulatory mechanisms of chestnut sugar biosynthesis metabolism, two chestnut varieties with different sugar content, namely Chengbu Youzhu (hereinafter referred to as CBYZ) and AnYou No. 1 (hereinafter referred to as AY01), were selected for investigation. Total sugar and starch content, and the activity of enzymes related to sugar accumulation, were measured in the nuts of the two chestnut varieties 10 days after flowering (DAF), 20 DAF, 30 DAF, 40 DAF, 50 DAF, 60 DAF, 70 DAF, 80 DAF, and 90 DAF. Changes in starch, straight-chain starch, and branched-chain starch content, and sucrose-phosphate synthase, soluble starch synthase, and granule-bound starch synthase enzyme activities were consistent with one-another. A total of 24 differentially expressed genes between the two varieties were associated with sugar biosynthesis and metabolism at three key stages (30, 60, and 90 DAF) of sugar accumulation. Further analysis showing upregulation of the expression of starch-related genes, such as ß-amylase, GYS, and INV indicated that these genes were not actively expressed in AY01, resulting in slow accumulation of starch and reduced sugar content. By contrast, the downregulation of the expression of genes, such as PGK and MDH1, indicated that these genes were actively expressed in low-sugar chestnuts, resulting in the rapid fermentation of sugars. A link between gene up- or down-regulation during different developmental stages of chestnut and the effect of their expression on sugar content were established by KEGG pathway enrichment analysis. These findings provide further insights into the mechanism of sugar biosynthesis in chestnuts.

Dietary calcium and magnesium intake and risk for incident dementia: The Shanghai Aging Study.

Introduction: Calcium (Ca), magnesium (Mg), or the calcium to magnesium (Ca:Mg) ratio may affect the risk of dementia via complex mechanisms. The aim of this study was to evaluate the association of dietary Ca, Mg, and Ca:Mg ratio with dementia risk at the prospective phase of the Shanghai Aging Study. Methods: We analyzed data from 1565 dementia-free participants living in an urban community who had measurements of dietary Ca and Mg intake derived from a food frequency questionnaire at baseline and incident dementia during follow-up. Results: Over the 5-year follow-up, 162 (10.4%) participants were diagnosed with incident dementia by Diagnostic and Statistical Manual of Mental Disorders, 4th edition criteria. Participants with the lowest tertile of dietary Ca (<339.1 mg/day) and Mg (<202.1 mg/day) had the highest incidence rates of dementia (3.3/100 person-years for Ca, 3.3/100 person-years for Mg) compared to those with higher Ca and Mg intake. In the subgroup with Ca:Mg ratios ≤ 1.69, Mg intake >267.5 mg/day was related to an increased risk for dementia (adjusted hazard ratio: 3.97, 95% confidence interval: 1.29-12.25). Conclusions: Our findings suggest that high dietary intake of Mg is associated with an increased risk of dementia mainly among older adults with low Ca:Mg intake ratios. Proper balance of Ca to Mg in the diet may be critical to the relationship between Mg intake and risk of dementia. Highlights: Participants with the lowest tertile of dietary calcium (Ca) and magnesium (Mg) had the highest incidence rates of dementia.In the subgroup with Ca:Mg ratios ≤1.69, Mg intake >267.5 mg/day was related to an increased risk for dementia.Balance of Ca to Mg in diet may be critical to the relationship between Mg intake and risk of dementia.

Air-gap Fabry-Pérot cavity filtered 30 nm broadband electro-optic frequency combs for high-order coherent communications.

Broadband electro-optic (EO) frequency combs, which have flexible and high repetition frequencies, are prospective light sources for dense-wavelength-division-multiplexed coherent optical communications. In most cases, nonlinear spectral broadening and amplification procedures are needed to achieve broadband and high-power EO frequency combs. This leads to a low optical carrier-to-noise ratio (OCNR) for comb lines, limiting the transmission capacity. Here, we propose to use an air-gap Fabry-Pérot (FP) cavity to improve the OCNR for all the comb lines covering a 30 nm broadband spectrum. A 12 dB OCNR (0.1 nm bandwidth) improvement is obtained experimentally via using an FP cavity with ∼790 MHz bandwidth. We apply a 150-channel filtered EO comb with 25 GHz channel spacing and load 20 GBaud signals on each comb line to demonstrate the effect of OCNR improvement. The 137/150 channels have a bit error rate below the threshold of soft-decision forward error correction when using the 128 quadrature amplitude modulation (QAM) format. However, none of these channels can support this modulation format without cavity filtering. We also investigate dispersion tolerance and the long-term stability when using an air-gap FP cavity, highlighting its advantages. Our results show a practical solution to boost the transmission capacity when applying broadband EO combs in optical communications.

Large-scale true-time-delay remote beamforming with EO frequency combs and multicore fiber.

Optical true-time-delay (OTTD) beamforming is a promising solution to support the ultra-broadband radio access network. However, large-scale antenna arrays set at remote radio units require the OTTD counterpart to have corresponding larger-scale channel numbers. Here, we demonstrate an OTTD remote beamforming network with a record 287 channel number using electro-optic frequency combs and multicore fiber. Our proposed scheme can generate beams for both one-dimensional and two-dimensional antenna arrays. We highlight that using multicore fiber not only increases the channel numbers but also supports remote beamforming. We estimate the long-term stability of this remote beamforming network, and 1-ps-level relative time delay variation in 2 h is obtained when using multicore fiber. It is one order of magnitude better than using parallel single-mode fibers. Thus, highly stable beamforming is achieved. These results pave the way for the application of OTTD beamforming in 5G and beyond networks.

Selection of first-line systemic therapies for advanced hepatocellular carcinoma: A network meta-analysis of randomized controlled trials.

BACKGROUND: The majority of clinical trials of first-line systemic treatments for hepatocellular carcinoma (HCC) used placebo or sorafenib as comparators, and there are limited data providing a cross comparison of treatments in this setting, especially for newly-approved immune checkpoint inhibitor and vascular endothelial growth factor inhibitor combination treatments. AIM: To systematically review and compare response rates, survival outcomes, and safety of first-line systemic therapies for advanced hepatocellular carcinoma. METHODS: We searched PubMed, Science Direct, the Cochrane Database, Excerpta Medica Database, and abstracts from the American Society of Clinical Oncology 2020 annual congress. Eligible studies were randomized controlled trials of systemic therapy enrolling adults with advanced/unresectable HCC. Risk of bias was assessed with the Cochrane risk of bias tool for randomized controlled trials. A network meta-analysis was used to synthesize data and perform direct and indirect comparisons between treatments. P value, a frequentist analog to the surface under the cumulative ranking curve, was used to rank treatments. RESULTS: In total, 1398 articles were screened and 27 included. Treatments compared were atezolizumab plus bevacizumab, brivanib, donafenib, dovitinib, FOLFOX4, lenvatinib, linifanib, nintedanib, nivolumab, sorafenib, sunitinib, vandetanib, 11 sorafenib combination therapies, and three other combination therapies. For overall response rate, lenvatinib ranked 1/19, followed by atezolizumab plus bevacizumab and nivolumab. For progression-free survival (PFS), atezolizumab + bevacizumab was ranked 1/15, followed by lenvatinib. With the exception of atezolizumab + bevacizumab [hazard ratios (HR)PFS = 0.90; 95% confidence interval (CI): 0.64-1.25], the estimated HRs for PFS for all included treatments vs lenvatinib were > 1; however, the associated 95%CI passed through unity for bevacizumab plus erlotinib, linifanib, and FOLFOX4. For overall survival, atezolizumab plus bevacizumab was ranked 1/25, followed by vandetanib 100 mg/d and donafinib, with lenvatinib ranked 6/25. Atezolizumab + bevacizumab was associated with a lower risk of death vs lenvatinib (HRos = 0.63; 95%CI: 0.44-0.89), while the HR for overall survival for most other treatments vs lenvatinib had associated 95%CIs that passed through unity. Vandetanib 300 mg/d and 100 mg/d were ranked 1/13 and 2/13, respectively, for the lowest incidence of treatment terminations due to adverse events, followed by sorafenib (5/13), lenvatinib (10/13), and atezolizumab + bevacizumab (13/13). CONCLUSION: There is not one single first-line treatment for advanced HCC associated with superior outcomes across all outcome measurements. Therefore, first-line systemic treatment should be selected based on individualized treatment goals.

Vitamin B12, B6, or Folate and Cognitive Function in Community-Dwelling Older Adults: A Systematic Review and Meta-Analysis.

BACKGROUND: Previous studies have indicated that B vitamin deficiencies are an essential cause of neurological pathology. There is a need to provide evidence of the benefit of B vitamins for the prevention of cognitive decline in community-dwelling older adults. OBJECTIVE: To examine the association between intake and plasma levels of vitamins B12, B6, and folate and cognitive function in older populations through a systematic review and meta-analysis. METHODS: Medline (PubMed), EMBASE, and Cochrane databases were used to search the literature though August 8, 2019. We included observational population-based studies evaluating the association between concentrations or intake levels of vitamins B6, B12, or folate and cognition in older adults aged ≥45 years. The quality of all studies was assessed by the modified Newcastle-Ottawa Scale. Odds ratios (ORs) and hazard ratios (HRs) were analyzed by the random-effects model. Sensitivity analyses were conducted by excluding the studies with significant heterogeneity. RESULTS: Twenty-one observational studies with sample sizes ranging from 155-7030 were included in the meta-analysis. Higher levels of vitamin B12 (OR = 0.77, 95% CI = 0.61-0.97) and folate concentration (OR = 0.68, 95% CI = 0.51-0.90) were associated with better cognition in cross-sectional studies, but not in sensitivity analyses or prospective studies. High vitamin B6 concentrations showed no significant benefit on cognition and dementia risk. Prospective studies did not provide substantial evidence for the relationship. CONCLUSION: The results from our meta-analysis suggest that vitamins B12, B6, and folate may not be modifiable risk factors for slowing cognitive decline among community-dwelling older individuals.

Effects of ipratropium bromide on the occurrence of postoperative respiratory complications in craniectomy patients with COPD: A nationwide multicenter retrospective study.

INTRODUCTION: Postoperative pulmonary complications (PPCs) are common and associated with increased morbidity, mortality, and medical cost. They are gaining increasing concerns among patients receiving neurological surgery. Chronic obstructive pulmonary disease (COPD) affect a large section of whole population and is also one of the risk factors of PPCs in the perioperative setting. Ipratropium bromide is the inhalation solution for the treatment of COPD. Studies showed the perioperative nebulization of ipratropium bromide could increase the lung function and decrease the incidence of postoperative pneumonia in COPD patients underwent thoracic surgery. The purpose of this study is to investigate the effect of perioperative nebulization of ipratropium bromide on PPCs in COPD patients underwent neurosurgical surgery. METHODS AND ANALYSIS: This study is a multicenter retrospective study in China. Patients who meet the inclusion/exclusion criteria are selected from 7 neurosurgical centers in China. According to whether ipratropium bromide is used in perioperative period, the patients are divided into exposure group and control group. The primary outcome is the incidence of postoperative pneumonia. Secondary outcomes are unplanned intubation, postoperative mechanical ventilation ≥ 48 hours, respiratory failure, atelectasis, death, and length of stay. ETHICS AND DISSEMINATION: This study was approved by the ethics committee (EC) of the School of Public Health, Fudan University, Shanghai, China. Waived by the ethics committee, no written consent form was obtained since we used the registry data. The study results will be communicated via publication. TRIAL REGISTRATION NUMBER: ChiCTR1900022552.

Data-driven approach for synchrotron X-ray Laue microdiffraction scan analysis.

A novel data-driven approach is proposed for analyzing synchrotron Laue X-ray microdiffraction scans based on machine learning algorithms. The basic architecture and major components of the method are formulated mathematically. It is demonstrated through typical examples including polycrystalline BaTiO3, multiphase transforming alloys and finely twinned martensite. The computational pipeline is implemented for beamline 12.3.2 at the Advanced Light Source, Lawrence Berkeley National Laboratory. The conventional analytical pathway for X-ray diffraction scans is based on a slow pattern-by-pattern crystal indexing process. This work provides a new way for analyzing X-ray diffraction 2D patterns, independent of the indexing process, and motivates further studies of X-ray diffraction patterns from the machine learning perspective for the development of suitable feature extraction, clustering and labeling algorithms.

C-Reactive Protein/Albumin Ratio Is an Independent Prognostic Predictor of Survival in Advanced Cancer Patients Receiving Palliative Care.

Background: The C-reactive protein/albumin (CRP/Alb) ratio has been reported as a prognostic factor of survival for patients with a variety of cancers. However, its prognostic impact for advanced cancer patients receiving palliative care remains presently unknown. Objective: The present study assessed the prognostic value of the CRP/Alb ratio, and compared this with that of the Glasgow Prognostic Score (GPS) and Palliative Prognostic Index (PPI) in a cohort of advanced cancer patients receiving palliative therapy. Methods: The medical records of 262 eligible patients who died of advanced cancer from February 1, 2013 to December 30, 2017 in the palliative care unit of the Fudan University Shanghai Cancer Center were retrospectively reviewed for the analysis. Results: The present results revealed that a CRP/Alb ratio ≥1.31 (hazard ratio [HR], 2.33 [1.78-3.05], p < 0.001) can predict poor prognosis through univariate analysis. In addition, the multivariate analysis revealed that CRP/Alb (HR, 2.09 [1.54-2.84], p < 0.001), GPS (HR, 1.81 [1.07-3.07], p < 0.001), and PPI (HR, 3.35 [2.25-4.99], p < 0.001) were all independent prognosis factors. To compare the discriminatory performance of the CRP/Alb ratio with that of other established prognostic indexes in palliative care settings, the c-statistics, integrated discriminatory improvement index, net reclassification index, and receiver operating characteristic curves were generated, and it was demonstrated that the CRP/Alb ratio (c-statistics, 0.64 [0.61-0.68]) was able to discriminate advanced cancer patients with different survivals, with analogous discriminatory ability as GPS (c-statistics, 0.63 [0.59-0.66]) and PPI (c-statistics, 0.64 [0.60-0.68]). Notably, the combination of multiple prognostic indexes exerted higher discriminatory ability, compared with any single predictive index (c-statistics, 0.69 [0.66-0.73], p < 0.001). Conclusions: The present study suggests that the CRP/Alb ratio is a promising prognostic factor in predicting cancer patient survival in palliative care settings. Incorporating both objective parameters and the subjective index may improve the prediction accuracy of prognosis.

[Association between RIPK4 relative copy number and prognosis of colorectal cancer patient after oxaliplatin-based chemotherapy].

OBJECTIVE: To investigate the association between receptor-interacting kinase protein 4 (RIPK4) relative copy number (RCN) and prognosis of stage III( colorectal cancer (CRC) patients treated with oxaliplatin-based chemotherapy. METHODS: RIPK4 RCN was determined by real-time PCR and then dichotomized into high RIPK4 RCN group(n=35) and low RIPK4 RCN group (n=104) using the third quartile as the cut-off point. Overall survival (OS) and recurrence-free survival (RFS) were compared between high and low RIPK4 RCN groups. The subgroup prognostic analysis was also conducted based on tumor site. RESULTS: The median follow-up period was 49 months (ranged 4 to 98 months). Patients with high RIPK4 RCN had poorer OS than those with low RIPK4 RCN, which reached marginal significance(median OS, 43.0 months vs. 53.5 months, P=0.074). Meanwhile there was no significant difference of RFS between two groups (P=0.352). In colon cancer subgroup, high RIPK4 RCN was significantly associated with poor OS (median OS, 31.5 months vs. 56.6 months, P=0.015) but not with RFS (P=0.135). In rectal cancer subgroup, RIPK4 RCN was not associated with both OS and RFS (P=0.981, P=0.738). Multivariate analysis revealed that high RIPK4 RCN was an independent prognostic factor of OS in stage III( CRC patients treated with oxaliplatin-based chemotherapy (HR=2.903, 95% CI: 1.275 to 6.610). CONCLUSION: RIPK4 RCN is significantly associated with OS in stage III( colon cancer patients receiving oxaliplatin-based chemotherapy and may be a novel biomarker that can predict the efficacy of oxaliplatin in colon cancer patients.

PPP1R12A Copy Number Is Associated with Clinical Outcomes of Stage III CRC Receiving Oxaliplatin-Based Chemotherapy.

AIM: To investigate the correlation between PPP1R12A gene copy number and clinical outcomes of oxaliplatin-based regimen in stage III colorectal cancer (CRC). METHODS: A total of 139 paraffin-embedded tissue samples of stage III CRC patients who received oxaliplatin-based treatment after radical surgery were recruited. Genomic DNA was extracted and purified from paraffin-embedded sections. Quantitative PCR methods were used to detect the relative copy number (RCN) of PPP1R12A. RESULTS: Statistical analysis demonstrated that low PPP1R12A RCN was associated with poor RFS (HR = 2.186, 95% CI: 1.293-3.696; P = 0.003) and OS (HR = 2.782, 95% CI: 1.531-5.052; P < 0.001). Additionally, when patients were stratified according to subgroups of stage III and tumor location, poor RFS and OS were also observed in the low PPP1R12A RCN group with significance (RFS: IIIB HR = 2.870, P < 0.001; colon HR = 1.910, P = 0.037; OS: IIIB HR = 3.527, P < 0.001; IIIC HR = 2.662, P = 0.049; rectum HR = 4.229, P = 0.002). CONCLUSION: Our findings suggest the copy number of PPP1R12A can independently predict recurrence and overall survival of stage III colorectal cancer patients receiving oxaliplatin-based chemotherapy.

PIK3C2G copy number is associated with clinical outcomes of colorectal cancer patients treated with oxaliplatin.

PURPOSE: To investigate whether the copy number of PIK3C2G is associated with clinical outcomes for stage III colorectal cancer (CRC) patients treated with oxaliplatin-based chemotherapy. METHODS: A total of 142 CRC patients who received first-line oxaliplatin-based chemotherapy after curative surgery in Ruijin Hospital and The Tenth People's Hospital were recruited in this study. Patients were enrolled between June 2006 and December 2011, with follow-up to January 2014. Quantitative real-time PCR method was used to detect the copy number of PIK3C2G. Cox proportional hazards model and Kaplan-Meier curves were used to analyze the association between PIK3C2G copy number and clinical outcome. RESULTS: In patients with stage III disease, low copy number of PIK3C2G was associated with increased risk of both recurrence (HR, 2.44, 95% CI, 1.33-4.47, P=0.004) and death (HR, 2.89, 95% CI, 1.49-5.60, P=0.002). Multivariate analysis also indicated that low PIK3C2G copy number was a significant and independent predictor of OS and RFS of stage III CRC. CONCLUSIONS: PIK3C2G is capable of predicting the recurrence and overall survival of stage III CRC patients receiving oxaliplatin-based therapy.