Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Design of multi-edge-type bilayer-expurgated LDPC codes for decode-and-forward in relay channels

We consider the design of bilayer-expurgated low- density parity-check (BE-LDPC) codes as part of a decode- and-forward protocol for use over the full-duplex relay chan- nel. A new ensemble of codes, termed multi-edge-type bilayer- expurgated LDPC (MET-BE-LDPC) codes, is introduced where the BE-LDPC code design problem is transformed into the problem of optimizing the multinomials of a multi-edge-type LDPC code. We propose two design strategies for optimizing MET-BE-LDPC codes; the bilayer approach is preferred when the difference in SNR between the source-to-relay and the source- to-destination channels is small, while the bilayer approach with intermediate rates is preferred when this difference is large. In both proposed design strategies multi-edge-type density evolution is used for code optimization. The resulting MET-BE-LDPC codes exhibit improved threshold and bit-error-rate performance as compared to previously reported bilayer LDPC codes

Universal LDPC codes for cooperative communications

Cooperative communication is a well known technique to yield transmit diversity in the case of fading channels and to increase the spectral efficiency in the case of Gaussian channels. Error-correcting codes have to be carefully designed to achieve the promised gains. Good LDPC codes are known for fading channels and for Gaussian channels, but an LDPC code ensemble that performs well on both channels has not yet been presented in the literature. This paper merges two families of LDPC codes into a universal LDPC code ensemble for both fading channels and Gaussian channels. Furthermore, the new universal LDPC code ensemble outperforms previously proposed codes on the block fading channel, which is explained through a fading space analysis. Simulation of the word error rate performance of the new proposed family of LDPC codes shows that it performs well on both fading channels and Gaussian channels

Extraction and Isolation of Cellulose Nanofibers from Carpet Wastes Using Supercritical Carbon Dioxide Approach

Cellulose nanofibers (CNFs) are the most advanced bio-nanomaterial utilized in various applications due to their unique physical and structural properties, renewability, biodegradability, and biocompatibility. It has been isolated from diverse sources including plants as well as textile wastes using different isolation techniques, such as acid hydrolysis, high-intensity ultrasonication, and steam explosion process. Here, we planned to extract and isolate CNFs from carpet wastes using a supercritical carbon dioxide (Sc.CO2) treatment approach. The mechanism of defibrillation and defragmentation caused by Sc.CO2 treatment was also explained. The morphological analysis of bleached fibers showed that Sc.CO2 treatment induced several longitudinal fractions along with each fiber due to the supercritical condition of temperature and pressure. Such conditions removed th fiber’s impurities and produced more fragile fibers compared to untreated samples. The particle size analysis and Transmission Electron Microscopes (TEM) confirm the effect of Sc.CO2 treatment. The average fiber length and diameter of Sc.CO2 treated CNFs were 53.72 and 7.14 nm, respectively. In comparison, untreated samples had longer fiber length and diameter (302.87 and 97.93 nm). The Sc.CO2-treated CNFs also had significantly higher thermal stability by more than 27% and zeta potential value of −38.9± 5.1 mV, compared to untreated CNFs (−33.1 ± 3.0 mV). The vibrational band frequency and chemical composition analysis data confirm the presence of cellulose function groups without any contamination with lignin and hemicellulose. The Sc.CO2 treatment method is a green approach for enhancing the isolation yield of CNFs from carpet wastes and produce better quality nanocellulose for advanced applications