45 research outputs found
An antiviral trap made of protein nanofibrils and iron oxyhydroxide nanoparticles
Minimizing the spread of viruses in the environment is the first defence line when fighting outbreaks and pandemics, but the current COVID-19 pandemic demonstrates how difficult this is on a global scale, particularly in a sustainable and environmentally friendly way. Here we introduce and develop a sustainable and biodegradable antiviral filtration membrane composed of amyloid nanofibrils made from food-grade milk proteins and iron oxyhydroxide nanoparticles synthesized in situ from iron salts by simple pH tuning. Thus, all the membrane components are made of environmentally friendly, non-toxic and widely available materials. The membrane has outstanding efficacy against a broad range of viruses, which include enveloped, non-enveloped, airborne and waterborne viruses, such as SARS-CoV-2, H1N1 (the influenza A virus strain responsible for the swine flu pandemic in 2009) and enterovirus 71 (a non-enveloped virus resistant to harsh conditions, such as highly acidic pH), which highlights a possible role in fighting the current and future viral outbreaks and pandemics
Electrocardiographic features of immune checkpoint inhibitor associated myocarditis
Background Myocarditis is a highly morbid complication of immune checkpoint inhibitor (ICI) use that remains inadequately characterized. The QRS duration and the QTc interval are standardized electrocardiographic measures that are prolonged in other cardiac conditions; however, there are no data on their utility in ICI myocarditis. Methods From an international registry, ECG parameters were compared between 140 myocarditis cases and 179 controls across multiple time points (pre-ICI, on ICI prior to myocarditis, and at the time of myocarditis). The association between ECG values and major adverse cardiac events (MACE) was also tested. Results Both the QRS duration and QTc interval were similar between cases and controls prior to myocarditis. When compared with controls on an ICI (93±19 ms) or to baseline prior to myocarditis (97±19 ms), the QRS duration prolonged with myocarditis (110±22 ms, p<0.001 and p=0.009, respectively). In contrast, the QTc interval at the time of myocarditis (435±39 ms) was not increased compared with pre-myocarditis baseline (422±27 ms, p=0.42). A prolonged QRS duration conferred an increased risk of subsequent MACE (HR 3.28, 95% CI 1.98 to 5.62, p<0.001). After adjustment, each 10 ms increase in the QRS duration conferred a 1.3-fold increase in the odds of MACE (95% CI 1.07 to 1.61, p=0.011). Conversely, there was no association between the QTc interval and MACE among men (HR 1.33, 95% CI 0.70 to 2.53, p=0.38) or women (HR 1.48, 95% CI 0.61 to 3.58, p=0.39). Conclusions The QRS duration is increased in ICI myocarditis and is associated with increased MACE risk. Use of this widely available ECG parameter may aid in ICI myocarditis diagnosis and risk-stratification
Electrocardiographic features of immune checkpoint inhibitor associated myocarditis.
BACKGROUND: Myocarditis is a highly morbid complication of immune checkpoint inhibitor (ICI) use that remains inadequately characterized. The QRS duration and the QTc interval are standardized electrocardiographic measures that are prolonged in other cardiac conditions; however, there are no data on their utility in ICI myocarditis.
METHODS: From an international registry, ECG parameters were compared between 140 myocarditis cases and 179 controls across multiple time points (pre-ICI, on ICI prior to myocarditis, and at the time of myocarditis). The association between ECG values and major adverse cardiac events (MACE) was also tested.
RESULTS: Both the QRS duration and QTc interval were similar between cases and controls prior to myocarditis. When compared with controls on an ICI (93±19 ms) or to baseline prior to myocarditis (97±19 ms), the QRS duration prolonged with myocarditis (110±22 ms, p
CONCLUSIONS: The QRS duration is increased in ICI myocarditis and is associated with increased MACE risk. Use of this widely available ECG parameter may aid in ICI myocarditis diagnosis and risk-stratification
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
INTRODUCTION
Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic.
RATIONALE
We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs).
RESULTS
Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants.
CONCLUSION
Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
Tunable electrically small conical folded dipole antenna used as a Mesoband high-power microwave source
High-power microwave (HPM) moderate-band (MB) sources combine simple design concepts seen in ultrawideband (UWB) sources, but with longer pulses to produces higher energy spectral densities. These factors allow the designs to be more compact and less complicated than many narrowband HPM sources. In this letter, we will demonstrate from both simulation and experimental results the operation of a electrically small, tunable, self-resonant, mesoband source utilizing a conical folded dipole antenna as the energy storage and radiating element. The system is based on a previous design for an HPM folded helix antenna that has a resonant frequency of 46 MHz and is charged to 70 kV. The design presented here utilizes a tunable capacitance that allows the resonant frequency to be tuned between 52 and 87 MHz with ka =0.58 at the lowest resonant frequency
Cardiovascular Outcomes of Patients With Pulmonary Hypertension Undergoing Noncardiac Surgery
© 2019 Pulmonary hypertension (PH), defined by a mean pulmonary artery pressure of \u3e25mm Hg at rest, is strongly associated with morbidity and mortality in the perioperative period. The prevalence and outcomes of PH among patients referred for major noncardiac surgery in the United States are unknown. Patients ≥18 years of age hospitalized for noncardiac surgery were identified from Healthcare Cost and Utilization Project\u27s National Inpatient Sample data from 2004 to 2014. Pulmonary hypertension was defined by International Classification of Diseases, Ninth Revision diagnosis codes. The primary outcome was perioperative major adverse cardiovascular events (MACCE), defined as in-hospital death, myocardial infarction, or ischemic stroke. Among 17,853,194 hospitalizations for major noncardiac surgery, 143,846 (0.81%) had PH. MACCE occurred in 8.3% of hospitalizations with any diagnosis of PH in comparison to 2.0% of those without PH (p \u3c0.001), driven by an increased frequency of death (4.4% vs 1.1%, p \u3c0.001) and nonfatal myocardial infarction (3.2% vs 0.6%, p \u3c0.001). After adjusting for demographics, clinical covariates, and surgery type, PH remained independently associated with MACCE (aOR 1.43, 95% CI 1.40 to 1.46). In conclusion, PH is associated with perioperative major adverse cardiovascular events. Careful patient selection, recognition of perioperative risks, and appropriate intraoperative hemodynamic monitoring may improve perioperative cardiovascular outcomes
Probing the Separation Distance between Biological Nanoparticles and Cell Membrane Mimics Using Neutron Reflectometry with Sub-Nanometer Accuracy
Myocardial Injury after Noncardiac Surgery: A Systematic Review and Meta-Analysis
Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved. Myocardial injury after noncardiac surgery (MINS) is a common postoperative complication associated with adverse cardiovascular outcomes. The purpose of this systematic review was to determine the incidence, clinical features, pathogenesis, management, and outcomes of MINS. We searched PubMed, Embase, Central and Web of Science databases for studies reporting the incidence, clinical features, and prognosis of MINS. Data analysis was performed with a mixed-methods approach, with quantitative analysis of meta-analytic methods for incidence, management, and outcomes, and a qualitative synthesis of the literature to determine associated preoperative factors and MINS pathogenesis. A total of 195 studies met study inclusion criteria. Among 169 studies reporting outcomes of 530,867 surgeries, the pooled incidence of MINS was 17.9% [95% confidence interval (CI), 16.2-19.6%]. Patients with MINS were older, more frequently men, and more likely to have cardiovascular risk factors and known coronary artery disease. Postoperative mortality was higher among patients with MINS than those without MINS, both in-hospital (8.1%, 95% CI, 4.4-12.7% vs 0.4%, 95% CI, 0.2-0.7%; relative risk 8.3, 95% CI, 4.2-16.6, P \u3c 0.001) and at 1-year after surgery (20.6%, 95% CI, 15.9-25.7% vs 5.1%, 95% CI, 3.2-7.4%; relative risk 4.1, 95% CI, 3.0-5.6, P \u3c 0.001). Few studies reported mechanisms of MINS or the medical treatment provided. In conclusion, MINS occurs frequently in clinical practice, is most common in patients with cardiovascular disease and its risk factors, and is associated with increased short-and long-term mortality. Additional investigation is needed to define strategies to prevent MINS and treat patients with this diagnosis