A CMOS Compatible Silicon-on-Insulator Polarization Rotator Based on Symmetry Breaking of the Waveguide Cross Section

[EN] A polarization rotator in silicon-on-insulator technology based on breaking the symmetry of the waveguide cross section is reported. The 25-mu m-long device is designed to be integrated with standard grating couplers without the need for extra fabrication steps. Hence, fabrication is carried out by a 2-etch-step complementary metal-oxide-semiconductor compatible process using 193-nm deep ultraviolet lithography. A polarization conversion efficiency of more than -0.85 dB with insertion losses ranging from -1 to -2.5 dB over a wavelength range of 30 nm is demonstrated. © 1989-2012 IEEEThis work was supported by the European Commission under Project HELIOS (pHotonics Electronics functional Integration on CMOS), FP7-224312, TEC2008-06333 SINADEC and PROMETEO-2010-087 R&D Excellency Program (NANOMET).Aamer, M.; Gutiérrez Campo, AM.; Brimont, ACJ.; Vermeulen, D.; Roelkens, G.; Fedeli, J.; Håkansson, OA.... (2012). A CMOS Compatible Silicon-on-Insulator Polarization Rotator Based on Symmetry Breaking of the Waveguide Cross Section. IEEE Photonics Technology Letters. 24(22):2031-2034. https://doi.org/10.1109/LPT.2012.2218593S20312034242

10 Gbit/s error-free DPSK modulation using a push-pull dual-drive silicon modulator

[EN] We experimentally demonstrate a high-speed differential phase shift keying (DPSK) modulation using a silicon push-pull operated dual-drive Mach Zehnder modulator (MZM) based on carrier depletion. 5 Gbit/s and 10 Gbit/s error-free modulation is demonstrated by demodulating the generated DPSK modulated signal using a demodulation circuit based on a polarization delay interferometer through the use of a differential group delay (DGD). Furthermore, the potential for higher DPSK modulation speeds up to 20 Gbit/s is also demonstrated. The obtained results validate the potential to achieve higher order modulation formats, such as quadrature phase shift keying (QPSK), by arranging the MZM in a nested configuration. (C) 2013 Elsevier B.V. All rights reserved.Financial supports from HELIOS (Photonics Electronics Functional Integration on CMOS) FP7-224312 and Generalitat Valenciana under PROMETEO-2010-087 R&D Excellency Program (NANOMET) are acknowledged. M. Aamer and P. Sanchis thank Dr. Javier Herrera for his useful help. D.J. Thomson, F.Y. Gardes and G.T. Reed are supported by funding received from the UK EPSRC funding body under the grant “UK Silicon Photonics”.Aamer, M.; Thomson, DJ.; Gutiérrez Campo, AM.; Brimont, ACJ.; Gardes, FY.; Reed, GT.; Fedeli, JM.... (2013). 10 Gbit/s error-free DPSK modulation using a push-pull dual-drive silicon modulator. Optics Communications. 304:107-110. https://doi.org/10.1016/j.optcom.2013.04.051S10711030

Silicon Differential Receiver With Zero-Biased Balanced Detection for Access Networks

[EN] We present an optimized differential receiver in silicon with a minimized footprint and balanced zero-biased Ge photodiodes. The receiver integrates a delay-line with a 2 ¿ 4 multimode interferometer 90° hybrid and two balanced photodiodes for differential quadrature phase-shift keying demodulation. Two receivers are tested, for 10 and 20 Gb/s operation, and well opened eye-diagrams and symbol constellations are obtained with error vector magnitude values as low as 12.5% and 19.57%, respectively. The results confirm the potential of integrated silicon receivers to become key building blocks for future passive optical access networks based on advanced modulation formats. © 1989-2012 IEEE.This work was supported in part by the European Community’s Seventh Framework Program under Grant 224312 HELIOS.Aamer, M.; Sotiropoulos, N.; Brimont, ACJ.; Fedeli, J.; Marris-Morini, D.; Cassan, E.; Vivien, L.... (2013). Silicon Differential Receiver With Zero-Biased Balanced Detection for Access Networks. IEEE Photonics Technology Letters. 25(13):1207-1210. https://doi.org/10.1109/LPT.2013.2262931S12071210251

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

© 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licenseBackground: 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods: This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494. Findings: Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation: Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding: National Institute for Health Research Global Health Research Unit

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

© 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide. Methods: A multimethods analysis was performed as part of the GlobalSurg 3 study—a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital. Findings: Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3·85 [95% CI 2·58–5·75]; p<0·0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63·0% vs 82·7%; OR 0·35 [0·23–0·53]; p<0·0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer. Interpretation: Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised. Funding: National Institute for Health and Care Research