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Nonlinear frequency division multiplexing (NFDM) is a promising optical transmission system that avoids fiber nonlinear effects, but suffering from unsatisfied spectral efficiency due to the guard interval (GI) devoting to combat the cumulative chromatic dispersion (CD), whose contribution to efficiency declination is quadratic to the bandwidth. In this paper, we propose what we believe to be a novel digital sub-band multiplexed (DSBM) NFDM system that can diminish the minimal required guard interval and therefore realize considerable information rate without reliability degradation. Through numerical simulation, we show that root raised cosine (RRC) shaped subcarriers are more suitable than the commonly used orthogonal frequency division multiplexing (OFDM) shaped ones in our DSBM-NFDM system. By multiplexing 15 sub-bands, we achieve a 129.7% improvement in effective information rate (EIR) compared to the single channel (SC) NFDM system with the same effective bandwidth. Meanwhile, we achieve a net information rate of 531.0 Gbps NFDM transmission over 960 km with SE of 3.86 bit/s/Hz, which is below the hard decision forward error correction (HD-FEC) threshold. This work is the first to introduce the DSBM technique into NFDM system, and it can be considered as a novel subcarrier shaping scheme for NFDM that has potential to advance its practical implementation.
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http://dx.doi.org/10.1364/OE.522175 | DOI Listing |
JAMA Netw Open
September 2025
Division of Gastroenterology, Department of Medicine, University of California San Diego, La Jolla.
Importance: Janus kinase (JAK) inhibitors are highly effective medications for several immune-mediated inflammatory diseases (IMIDs). However, safety concerns have led to regulatory restrictions.
Objective: To compare the risk of adverse events with JAK inhibitors vs tumor necrosis factor (TNF) antagonists in patients with IMIDs in head-to-head comparative effectiveness studies.
JAMA Netw Open
September 2025
Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
Importance: Lower survival rates among Black adults relative to White adults after in-hospital cardiac arrest are well-described, but these findings have not been consistently replicated in pediatric studies.
Objective: To use a large, national, population-based inpatient database to evaluate the associations between in-hospital mortality in children receiving cardiopulmonary resuscitation (CPR) and patient race or ethnicity, patient insurance status, and the treating hospital's proportion of Black and publicly insured patients.
Design, Setting, And Participants: This retrospective population-based cohort study used the Healthcare Cost and Utilization Project Kids' Inpatient Database (1997-2019 triennial versions).
JAMA Netw Open
September 2025
Critical Illness, Brain Dysfunction, and Survivorship Center, Vanderbilt University Medical Center, Nashville, Tennessee.
Importance: Survivors of critical illness often have ongoing issues that affect functioning, including driving ability.
Objective: To examine whether intensive care unit (ICU) delirium is independently associated with long-term changes in driving behaviors.
Design, Setting, And Participants: This multicenter, longitudinal cohort study included 151 survivors of critical illness residing within 200 miles of Nashville, Tennessee.
JAMA Netw Open
September 2025
Social and Behavioral Sciences Branch, Division of Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland.
Importance: Higher intellectual abilities have been associated with lower mortality risk in several longitudinal cohort studies. However, these studies did not fully account for early life contextual factors or test whether the beneficial associations between higher neurocognitive functioning and mortality extend to children exposed to early adversity.
Objective: To explore how the associations of child neurocognition with mortality changed according to the patterns of adversity children experienced.
Curr Atheroscler Rep
September 2025
Division of Gastroenterology and Hepatology, Lynda K. and David M. Underwood Center for Digestive Health, Houston Methodist Hospital, Houston, TX, USA.
Purpose Of Review: This review aims to characterize the known cardiovascular (CV) manifestations associated with inflammatory bowel disease (IBD) and the underlying mechanisms driving these associations.
Recent Findings: Gut dysbiosis, a hallmark of patients with IBD, can result in both local and systemic inflammation, thereby potentially increasing the risk of cardiovascular disease (CVD) in the IBD population. Micronutrient deficiencies, anemia, and sarcopenia independently increase the risk of CVD and are frequent comorbidities of patients with IBD.