Graph model for multiple scattering in lithium niobate on insulator integrated photonic networks.

We present a graph-based model for multiple scattering of light in integrated lithium niobate on insulator (LNOI) networks, which describes an open network of single-mode integrated waveguides with tunable scattering at the network nodes. We first validate the model at small scale with experimental LNOI resonator devices and show consistent agreement between simulated and measured spectral data. Then, the model is used to demonstrate a novel platform for on-chip multiple scattering in large-scale optical networks up to few hundred nodes, with tunable scattering behaviour and tailored disorder. Combining our simple graph-based model with material properties of LNOI, this platform creates new opportunities to control randomness in large optical networks.

Temporal trends in mortality and provision of intensive care in younger women and men with acute myocardial infarction or stroke.

BACKGROUND: Timely management of acute myocardial infarction (AMI) and acute stroke has undergone impressive progress during the last decade. However, it is currently unknown whether both sexes have profited equally from improved strategies. We sought to analyze sex-specific temporal trends in intensive care unit (ICU) admission and mortality in younger patients presenting with AMI or stroke in Switzerland. METHODS: Retrospective analysis of temporal trends in 16,954 younger patients aged 18 to ≤ 52 years with AMI or acute stroke admitted to Swiss ICUs between 01/2008 and 12/2019. RESULTS: Over a period of 12 years, ICU admissions for AMI decreased more in women than in men (- 6.4% in women versus - 4.5% in men, p < 0.001), while ICU mortality for AMI significantly increased in women (OR 1.2 [1.10-1.30], p = 0.032), but remained unchanged in men (OR 0.99 [0.94-1.03], p = 0.71). In stroke patients, ICU admission rates increased between 3.6 and 4.1% per year in both sexes, while ICU mortality tended to decrease only in women (OR 0.91 [0.85-0.95, p = 0.057], but remained essentially unaltered in men (OR 0.99 [0.94-1.03], p = 0.75). Interventions aimed at restoring tissue perfusion were more often performed in men with AMI, while no sex difference was noted in neurovascular interventions. CONCLUSION: Sex and gender disparities in disease management and outcomes persist in the era of modern interventional neurology and cardiology with opposite trends observed in younger stroke and AMI patients admitted to intensive care. Although our study has several limitations, our data suggest that management and selection criteria for ICU admission, particularly in younger women with AMI, should be carefully reassessed.

High-bandwidth thermo-optic phase shifters for lithium niobate-on-insulator photonic integrated circuits.

Phase shifters are key components of large-scale photonic integrated circuits. For the lithium niobate-on-insulator (LNOI) platform, thermo-optic phase shifters (TOPS) have emerged as a more stable and compact alternative to common electro-optic phase shifters (EOPSs), which are prone to anomalous behavior and drifting at low frequencies. Here, we model and experimentally characterize the influence of geometry on the performance of metal strip TOPSs. Compared to EOPSs, a 10-fold reduction of the voltage-length product is measured and bandwidths beyond 100 kHz are demonstrated, while keeping the footprint as low as 0.04 mm2. This shows the potential of TOPSs as small-scale building blocks for stable tuning and switching in LNOI photonic circuits.

Monolithic thin-film lithium niobate broadband spectrometer with one nanometre resolution.

Miniaturised optical spectrometers are attractive due to their small footprint, low weight, robustness and stability even in harsh environments such as space or industrial facilities. We report on a stationary-wave integrated Fourier-transform spectrometer featuring a measured optical bandwidth of 325 nm and a theoretical spectral resolution of 1.2 nm. We fabricate and test on lithium niobate-on-insulator to take full advantage of the platform, namely electro-optic modulation, broad transparency range and the low optical loss achieved thanks to matured fabrication techniques. We use the electro-optic effect and develop innovative layouts to overcome the undersampling limitations and improve the spectral resolution, thus providing a framework to enhance the performance of all devices sharing the same working principle. With our work, we add another important element to the portfolio of integrated lithium-niobate optical devices as our spectrometer can be combined with multiple other building blocks to realise functional, monolithic and compact photonic integrated circuits.

Gender differences in the provision of intensive care: a Bayesian approach.

PURPOSE: It is currently unclear whether management and outcomes of critically ill patients differ between men and women. We sought to assess the influence of age, sex and diagnoses on the probability of intensive care provision in critically ill cardio- and neurovascular patients in a large nationwide cohort in Switzerland. METHODS: Retrospective analysis of 450,948 adult patients with neuro- and cardiovascular disease admitted to all hospitals in Switzerland between 01/2012 and 12/2016 using Bayesian modeling. RESULTS: For all diagnoses and populations, median ages at admission were consistently higher for women than for men [75 (64;82) years in women vs. 68 (58;77) years in men, p < 0.001]. Overall, women had a lower likelihood to be admitted to an intensive care unit (ICU) than men, despite being more severely ill [odds ratio (OR) 0.78 (0.76-0.79)]. ICU admission probability was lowest in women aged > 65 years (OR women:men 0.94 (0.89-0.99), p < 0.001). Women < 45 years had a similar ICU admission probability as men in the same age category [OR women:men 1.03 (0.94-1.13)], in spite of more severe illness. The odds to die were significantly higher in women than in men per unit increase in Simplified Acute Physiology Score (SAPS) II (OR 1.008 [1.004-1.012]). CONCLUSION: In the care of the critically ill, our study suggests that women are less likely to receive ICU treatment regardless of disease severity. Underuse of ICU care was most prominent in younger women < 45 years. Although our study has several limitations that are imposed by the limited data available from the registries, our findings suggest that current ICU triage algorithms could benefit from careful reassessment. Further, and ideally prospective, studies are needed to confirm our findings.