15 research outputs found

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

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    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

    A Superior Method for Constructing Electrical Percolation Network of Nanocomposite Fibers: In Situ Thermally Reduced Silver Nanoparticles

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    Nanocomposite fibers, composed of conductive nanoparticles and polymer matrix, are crucial for wearable electronics. However, the nanoparticle mixing approach results in aggregation and dispersion problems. A revolutionary synthesis method by premixing silver precursor ions (silver ammonium acetate) with polyvinyl alcohol is reported here. The solvation of ions-prevented aggregation, and uniformly distributed silver nanoparticles (in situ AgNPs, 77 nm) are formed after thermal reduction (155 degrees C) without using additional reducing or dispersion agents. The conductive fiber is synthesized by the wet spinning technology. After careful optimization, flower-shaped silver nanoparticles (AgNFs, 350-450 nm) are also employed as cofillers. The addition of in situ AgNPs (9.5 vol%) to AgNFs (30 vol%) increases electrical conductivity by 1434% (2090 to 32 064 S cm(-1)) through the efficient construction of percolation networks. The in situ AgNPs provide significantly higher conductivity compared with other secondary nanoparticle fillers. The gaseous byproducts dramatically increase flexibility with a moderate compromise in tensile strength (55 MPa). The particle-free ion-level uniform mixing of silver precursors, followed by in situ reduction, would be a fundamental paradigm shift in nanocomposite synthesis.© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

    Silver nanoflowers for single-particle SERS with 10 pM sensitivity

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    Surface-enhanced Raman scattering (SERS) has received considerable attention as a noninvasive optical sensing technique with ultrahigh sensitivity. While numerous types of metallic particles have been actively investigated as SERS substrates, the development of new SERS agents with high sensitivity and their reliable characterization are still required. Here we report the preparation and characterization of flower-shaped silver (Ag) nanoparticles that exhibit high-sensitivity single-particle SERS performance. Ag nanoflowers (NFs) with bud sizes in the range 220-620 nm were synthesized by the wet synthesis method. The densely packed nanoscale petals with thicknesses in the range 9-22 nm exhibit a large number of hot spots that significantly enhance their plasmonic activity. A single Ag NF particle (530-620 nm) can detect as little as 10(-11) M 4-mercaptobenzoic acid, and thus provides a sensitivity three orders of SERS magnitude greater than that of a spherical Ag nanoparticle. The analytical enhancement factors for single Ag NF particles were found to be as high as 8.0 x 10(9), providing unprecedented high SERS detectivity at the single particle level. Here we present an unambiguous and systematic assessment of the SERS performances of the Ag NFs and demonstrate that they provide highly sensitive sensing platforms by single SERS particle. © 2017 IOP Publishing Ltd Printed in the UK1341sciescopu

    Hierarchically-structured silver nanoflowers for highly conductive metallic inks with dramatically reduced filler concentration

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    Silver has long been employed as an electrically conductive component, and morphology-dependent properties have been actively investigated. Here we present a novel scalable synthesis method of flower-shaped silver nanoparticles (silver nanoflowers, Ag NFs). The preferential affinity of citrate molecules on (111) surface of silver enabled spontaneous anisotropic growth of Ag NFs (bud size:250~580 nm, single crystalline petal thickness: 9~22 nm) with high reproducibility and a high yield of >99.5%. The unique hierarchical structure resulted in coalescence of petals over 80~120 °C which was practically employed in conductive inks to construct percolation pathways among Ag NFs. The ink with only 3 wt% of Ag NFs provided two orders of magnitude greater conductivity (1.008 × 105 Scm−1), at a low curing temperature of 120 °C, compared with the silver nanoparticle ink with a much higher silver concentration (50 wt%). This extraordinary property may provide an excellent opportunity for Ag NFs for practical applications in printable and flexible electronics. © The Author(s) 20161351sciescopu

    In-situ reduced non-oxidized copper nanoparticles in nanocomposites with extraordinary high electrical and thermal conductivity

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    © 2021 Elsevier Ltd. Copper has received considerable attention for conductive nanocomposites as an alternative to costly silver or gold. However, practical application has been impeded by its susceptibility to oxidation in air. Here we report a novel scalable synthesis method of non-oxidized copper nanoparticles (InSituCuNPs) by pre-mixing and in-situ reducing copper formate-(butylamine-octylamine) complex inside soft epoxy matrix. The solid–liquid phase change of the copper formate complex, during the nanocomposite spark-plasma-sintering process, promotes uniform dispersion. Even the outermost atoms of InSituCuNPs are not oxidized since they are surrounded by the thick matrix polymer as soon as in-situ reduced into metallic copper, resulting in high electrical (15,048 Scm−1) and thermal (28.4 Wm−1K−1) conductivities of the nanocomposite. Furthermore, a small addition of 1-dimensional carbon nanotubes decorated with 0-dimensional copper nanoparticles (<4 nm), together with bi-functionalization, dramatically enhances connectivity between the InSituCuNPs, resulting in air-stable and record-high 31,974 Scm−1 and 74.1 Wm−1K−1 for isotropic copper-based nanocomposites. The nanocomposite also provides a small thermal resistance (2.64 × 10−6 m2KW−1) and excellent heat dissipation performance.11Nsciescopu

    Evaluation Of Post Traumatic Stress Disorder And Its Complications

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    Post-traumatic stress disorder (PTSD) remains a widespread mental health challenge with profound consequences for people exposed to traumatic events. This review provides a comprehensive&nbsp; and critical appraisal of recent research on PTSD and sheds light on the complexities of its diagnosis, etiology, and treatment. The review includes a comprehensive analysis of the various methods used in PTSD research, including neurobiological, psychological, and sociocultural perspectives. It examines the impact of evolving diagnostic criteria and emphasizes the need to understand the nuances of symptoms and their heterogeneity in different populations. In addition, this summary discusses complications associated with PTSD research, such as comorbidities, cultural variations, and the influence of genetic factors. The interaction between trauma severity, resilience factors and the likelihood of developing chronic PTSD is explored, providing insight into the different trajectories observed in affected individuals. The review also discusses advances in therapeutic interventions, from traditional psychotherapeutic approaches to new pharmacological and neuromodulatory strategies. Special attention is given to the challenges of implementing evidence-based treatment and the need to tailor individualized treatments tailored to the unique needs of PTSD patients. Together, this summary summarizes the current state of PTSD research, highlights gaps in knowledge, and suggests avenues for future research. The complexity of PTSD research requires a multidimensional approach that integrates biological, psychological and sociocultural factors, ultimately contributing to a more comprehensive understanding of the disorder and improved treatment outcomes. &nbsp

    Non-oxidized bare copper nanoparticles with surface excess electrons in air

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    © 2022 Springer Nature Limited. Copper (Cu) nanoparticles (NPs) have received extensive interest owing to their advantageous properties compared with their bulk counterparts. Although the natural oxidation of Cu NPs can be alleviated by passivating the surfaces with additional moieties, obtaining non-oxidized bare Cu NPs in air remains challenging. Here we report that bare Cu NPs with surface excess electrons retain their non-oxidized state over several months in ambient air. Cu NPs grown on an electride support with excellent electron transfer ability are encapsulated by the surface-accumulated excess electrons, exhibiting an ultralow work function of ~3.2 eV. Atomic-scale structural and chemical analyses confirm the absence of Cu oxide moiety at the outermost surface of air-exposed bare Cu NPs. Theoretical energetics clarify that the surface-accumulated excess electrons suppress the oxygen adsorption and consequently prohibit the infiltration of oxygen into the Cu lattice, provoking the endothermic reaction for oxidation process. Our results will further stimulate the practical use of metal NPs in versatile applications.11Nsciescopu
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