The Coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is overwhelming healthcare resources and infrastructure worldwide. Cardiac surgical operating capacity during the COVID-19 pandemic is dramatically lower due to postponement or cancellation of elective or semi-urgent procedures. Earlier reports have demonstrated complicated post-operative courses and high fatality rates in patients undergoing emergent cardiothoracic surgery who were diagnosed post-operatively with COVID-19. These reports raise the possibility that active COVID-19 might precipitate a catastrophic pathophysiogical response to infection in the post-operative period and lead to unfavorable surgical outcomes. Hence, it is imperative to screen patients with SARS-CoV-2 infection prior to surgery and to carefully monitor them in the post-operative period to identify any early signs of active COVID-19. In this report, we present the successful outcome of coronary artery bypass grafting (CABG) operation in a patient with asymptomatic SARS-CoV-2 infection presenting with an acute coronary syndrome and requiring urgent surgical intervention. We employed a meticulous strategy to identify subclinical COVID-19 disease, and after confirming the absence of active disease, proceeded with the CABG operation. The patient outcome was successful with the absence of any overt COVID-19 manifestations in the post-operative period.
This is a response to the Letter to Editor received regarding the article “The effect of patient obesity on extracorporeal membrane oxygenator outcomes and ventilator dependency.” We aim to address the authors’ comments regarding the relationship between BMI and survival after venoarterial extracorporeal membrane oxygenation (VA-ECMO).
This paper is concerned with an initial and boundary value problem of the Navier-Stokes equations for compressible viscous barotropic flow subject to large external potential forces in a half space $R^3_+$ with Navier’s boundary conditions. The global well-posedness of strongsolutions with large oscillations and vacuum is established, provided that the initial energy is suitably small and that the unique steady state is strictly away from vacuum. As a by-product,the stability of stationary solution is obtained.
Gross primary production (GPP) is a key component of the forest carbon cycle. However, our knowledge of GPP at the stand scale remains uncertain because estimates derived from eddy covariance (EC) rely on semi-empirical modeling and the assumptions of the EC technique are sometimes not fully met. We propose using the sap flux/isotope method as an alternative way to estimate canopy GPP, termed GPPiso/SF, at the stand scale and at daily resolution. It is based on canopy conductance inferred from sap flux and intrinsic water-use efficiency estimated from the stable carbon isotope composition of phloem contents. The GPPiso/SF estimate was further corrected for seasonal variations in photosynthetic capacity and mesophyll conductance. We compared our estimate of GPPiso/SF to the GPP derived from PRELES, a model parameterised with EC data. The comparisons were performed in a highly instrumented, boreal Scots pine forest in northern Sweden, including a nitrogen fertilised and a reference plot. The resulting annual and daily GPPiso/SF estimates agreed well with PRELES, in the fertilised plot and the reference plot. We discuss the GPPiso/SF method as an alternative which can be widely applied without terrain restrictions, where the assumptions of EC are not met.
As global trade of live animals expands, there is increasing need to assess the risks of invasive organisms, including pathogens, that can accompany these translocations. The movement and release of live baitfish by recreational anglers has been identified as a particularly high-risk pathway for the spread of aquatic diseases in the United States. To provide risk-based decision support for preventing and managing disease invasions from baitfish release, we developed a hazard identification and ranking tool to identify the pathogens that pose the highest risk to wild fish via this pathway. We created a screening protocol and semi-quantitative stochastic risk ranking framework, combining published data with expert elicitation (n=25) and applied the framework to identify high-priority pathogens for the bait supply in Minnesota, USA. Normalized scores were developed for seven risk criteria (likelihood of transfer, prevalence in bait supply, likelihood of colonization, current distribution, economic impact if established, ecological impact if established, and host species) to characterize a pathogen’s ability to persist in the bait supply and cause impacts to wild fish species of concern. The generalist macroparasite Schizocotyle acheilognathi was identified as presenting highest overall threat, followed by the microsporidian Ovipleistophora ovariae, and viral hemorrhagic septicemia virus. Our findings provide risk-based decision support for managers charged with maintaining both the recreational fishing industry and sustainable, healthy natural resources. The ranking process, implemented here for a single state case study, provides a standardized conceptual framework that could be applied across jurisdictions to inform risk-based management of the live baitfish pathway.
This study investigates the application of a recently developed construct, the Uniform Trigonometrization Method (UTM), to the singular control problems in chemical engineering. The UTM involves minimal modifications to the original problem, thereby generating near-singular control solutions that can be used for conceptual design and serve as an alternate to direct techniques like nested and simultaneous approaches. Eight classical singular control problems with known analytical solutions and three complex singular control problems from chemical engineering domain are solved in this study. The results obtained using the UTM for these problems are found to match well with the literature and are of higher resolution as compared to the results obtained using a direct pseudospectral based solver. The ability of the UTM to handle complex chemical engineering problems with both singular controls and state path constraints has also been demonstrated in this study.
Nitrogen-fixing Nepalese alder (Alnus nepalensis D. Don.) is a fast-growing early successional species which often forms pure stands in areas affected by landslides and sometimes it occurs mixed with other species in the central Himalayas. In this study, we assessed the distribution of ecosystem carbon storage in plants and soil in a chronosequence of A. nepalensis forest stands in central Himalaya. We examined six forest stands: (1) A. nepalensis-early regeneration (AER) forest, (2) A. nepalensis-late regeneration (ALR) forest, (3) A. nepalensis- mature oak mixed (AMOM) forest, sis tree biomass in different stand AER, APDF, ALR, AMOM, and AMR, AMOO, was 8.97, 51.41, 16.07, 53.74, 144.77, and 101.14 Mg ha-1, respectively. Soil organic C (SOC) in different soil depths in successional stages AER (0-10 cm), APDF (0-30 cm), ALR (0-100 cm), AMOM (0-100 cm), AMR (0-100 cm), and AMOO (0-100 cm) was 3.31, 31.21, 75.47, 157.04, 159.43 and 210.13 Mg ha-1, respectively, with decrease in SOC concentration with increasing soil depth. The ecosystem C storage averaged 15.85, 183, 216.26, 390.32, 403.66, and 500.08 Mg ha-1 in AER, APDF, ALR, AMOM, AMR, and AMOO sites, respectively. Overall, in A. nepalensis forest development markedly ameliorated both vegetation and soil succession in central Himalaya.
The authors share their experience of managing the cardiac surgery services across London during the challenging Covid-19 pandemic. The Pan London Emergency Cardiac Surgery Service model could serve as a blueprint to design policies applicable to other surgical specialities and parts of the UK and worldwide.
Extreme weather events have become a dominant feature of the narrative surrounding changes in global climate. with large impacts on ecosystem stability, functioning and resilience, however, understanding of their risk of co-occurrence at the regional scale is lacking. Based on the UK Met Office's long-term temperature and rainfall records, we present the first evidence demonstrating significant increases in the magnitude, direction of change and spatial co-localization of extreme weather events since 1961. Combining this new understanding with land use datasets allowed us to assess the likely consequences on future agricultural production and conservation priority areas. All land uses are impacted by the increasing risk of at least one extreme event and conservation areas were identified as hotspots of risk for the co-occurrence of multiple event types. Our findings provide a basis to regionally guide land use optimisation, land management practices and regulatory actions preserving ecosystem services against multiple climate threats.
The defected carbon materials as a metal-free catalyst shown superior stability and catalytic performance in the acetylene hydrochlorination reaction. Through DFT calculation, for the first time several different defected configurations comprising mono, di-vacancies, and Stone Wales defect on single-walled carbon nanotubes (SWCNTs) have been used as a direct catalyst for acetylene hydrochlorination reaction. These defective sites on SWCNTs are the most active site for acetylene hydrochlorination reaction compared to pristine SWCNT. The different configuration of defects have different electronic structure, which specify that mono-vacancy defect, have more states adjecent to the Fermi level. The reactant acetylene (C2H2) adsorbed strongly than hydrogen chloride (HCl) and expected to be the initial step of the reaction Acetylene adsorbed strongly at mono-vacancy defected SWCNT compared to other investigated defects. The reaction pathways analysis revealed that mono- and di-vacancy defected SWCNT has a minimum energy barriers and shows extraordinary performance towards acetylene hydrochlorination. This work suggests the potential of metal-free defected carbon to catalyze acetylene hydrochlorination and provide a solid base for future developments in acetylene hydrochlorination.
COVID-19 PANDEMIC: A CHALLENGE TO A CHILD WITH CANCER Dear Editor,People of all ages can be infected by the new coronavirus (2019-nCoV). Older people, and people with pre-existing medical conditions (such as asthma, diabetes, heart disease) are more vulnerable to becoming severely ill with the virus. There is a widespread anxiety among families of children with cancer due to risk of exposure to SARS-CoV-2, either in the hospital or community setting. Recently Ogimi et al  reported that infants and younger children (i.e., ≤5 years) are more likely to develop severe clinical manifestations than older children, maybe due to immaturity of the immune system. Sullivan et al  reported that the COVID-19 pandemic was one of the most serious global challenge to delivering affordable and equitable treatment to children with cancer. They have provided some practical advice for adapting diagnostic and treatment protocols for children with cancer during the pandemic, the measures to be taken to contain it (e.g. extreme social distancing) and how to prepare for the anticipated recovery period.The Government and administrative measures such as lockdown has further compounded these challenges. Lack of state transport, closure of district borders, non-availability of medications has put these children at risk of rapid growth of disease, delay in treatment and poor outcome. A four and half year-old child, a known case of synchronous bilateral Wilms tumour, having undergone bilateral nephron sparing surgery was on adjuvant chemotherapy. The COVID-19 pandemic brought about an interruption in his chemotherapy schedule in January 2020. When he presented in early May, he had a small swelling of 1.5 cm diameter below the left subcostal margin (Figure 1a). Ultra sonography revealed a hypoechoic lesion below the skin measuring 1.5 cm in diameter (Figure 1b). Fine needle aspiration cytology was done which revealed sheets of cells with high nuclear/cytoplasm ratio (Figure 1c). The features were highly suspicious of a malignant lesion. The lesion was excised and histo-pathological examination revealed a metastasis from WILMS tumour (Figure 1d). The child has been resumed on further chemotherapy.Most childhood cancers behave aggressively and need immediate treatment, often requiring prolonged periods of intensive multiagent chemotherapy. Postponement of treatment such as surgery, radiation and chemotherapy is not a safe option in children. There is an urgent need amongst health professionals and families for informed guidance on the range of reasonable and safe adaptations to their services and cancer treatment during the pandemic.Conflict of Interest: None.Compliance with Ethical Standards.
In December 2019, China reported the first cases of the coronavirus disease 2019 (COVID-19). This disease, caused by the severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2), has developed into a pandemic. To date it has resulted in ~5.6 million confirmed cases and caused 353,334 related deaths worldwide. Unequivocally, the COVID-19 pandemic is the gravest health and socio-economic crisis of our time. In this context, numerous questions have emerged in demand of basic scientific information and evidence-based medical advice on SARS-CoV-2 and COVID-19. Although the majority of the patients show a very mild, self-limiting viral respiratory disease, many clinical manifestations in severe patients are unique to COVID-19, such as severe lymphopenia and eosinopenia, extensive pneumonia, a “cytokine storm” leading to acute respiratory distress syndrome, endothelitis, thrombo-embolic complications and multiorgan failure. The epidemiologic features of COVID-19 are distinctive and have changed throughout the pandemic. Vaccine and drug development studies and clinical trials are rapidly growing at an unprecedented speed. However, basic and clinical research on COVID-19-related topics should be based on more coordinated high-quality studies. This paper answers pressing questions, formulated by young clinicians and scientists, on SARS-CoV-2, COVID-19 and allergy, focusing on the following topics: virology, immunology, diagnosis, management of patients with allergic disease and asthma, treatment, clinical trials, drug discovery, vaccine development and epidemiology. Over 140 questions were answered by experts in the field providing a comprehensive and practical overview of COVID-19 and allergic disease.
Tricuspid and pulmonary valve replacement in patients with carcinoid heart disease (CaHD) reduces right heart failure and improves prognosis. The surgical literature is limited concerning technical aspects of valve replacement in CaHD. Although dedicated multidisciplinary care is required, optimization of surgical details is important and may lead to better postoperative outcomes in these frail patients.
The present work analyses the behaviour of aqueous solutions of N,N-dimethylethylenediamine as chemical solvent for carbon dioxide separation by gas-liquid absorption. The interest of this molecule is centred on the presence of different types of amino centres that confer the capability to act as typical solvent based on mixtures of amines taking into account the suitable behaviour of some mixtures. For this reason a comparison between diamine and amine blend solvents has been carried out in order to understand the differences between these solvents using absorption and NMR studies. This experimental work analyses the influence of amine type, concentration and ratio between different amines. Also, the effect of gas flow rate used in the bubble column reactor upon the absorption kinetics has been analysed.
Medical Algorithm: Early Introduction of Food Allergens in High Risk PopulationsHelen R Fisher,1,2 Gideon Lack,1,2,3 Graham Roberts,4,5,6 Henry T Bahnson,7 George Du Toit.1,2,31Paediatric Allergy Group, Department of Women and Children’s Heath, School of Life Course Sciences, King’s College London, London, United Kingdom2Paediatric Allergy Group, Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, King’s College London, London, United Kingdom.3Children’s Allergy Service, Guy’s and St. Thomas’ NHS Foundation Trust, London, United Kingdom.4The David Hide Asthma and Allergy Research Centre, St Mary’s Hospital, Newport, UK.5NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK.6Faculty of Medicine, Clinical and Experimental Sciences, Human Development in Health Academic Units, University of Southampton, Southampton, UK.7Immune Tolerance Network, Benaroya Research Institute, Seattle, WashingtonCorresponding Authour:Professor George Du ToitPaediatric AllergyBlock B, South WingSt Thomas’ HospitalLondonSE1 7EHTel: 0207 188 9784Email: George.firstname.lastname@example.orgWord Count: 602Tables: 0Figures: 1Oral Tolerance Induction (OTI) is the only RCT-proven effective intervention for preventing childhood food allergy.(1) OTI to peanut is effective in a general population, with the greatest effect, 81% RRR, noted in the high-risk population.(2) OTI also reduced egg allergy in the general population.(1) Many governmental and allergy societies now recommend introducing peanut in infancy and some suggest other foods, such as well-cooked egg, are also introduced. Choosing which infants should undergo OTI, at what age, to which foods, and under which circumstances is critical for successful OTI prevention in populations where food allergy is a public health concern.Infants with eczema are at increased risk of food allergy but infants from the general population are also at risk and contribute most cases at a population level. Risk of food sensitisation or food allergy increase with age; OTI is most likely to be successful when started in early infancy. Oral tolerance induction from 4 months of age, when completed using standard foods, is safe for nutrition, growth and general child health outcomes (3). Commencing multiple food OTI at 4 months of age, has no detrimental effect on established breastfeeding.(4) All children should adopt a diverse weaning diet, including allergenic foods such as well-cooked egg and peanut, as soon as weaning commences. High risk children should not delay weaning but start weaning and actively include peanut and well-cooked egg, as soon as developmentally ready; usually at about 4 months of age (Fig 1).A 2g/week dosing regime of peanut and well-cooked egg in early infancy is more effective in inducing oral tolerance than later introduction.(5) A lower dosing regime has not been shown to be effective in preventing allergy but, importantly, does not increase allergy risk above that of children who introduce allergenic foods in later infancy.(4) There are limited data regarding the efficacy of OTI to other allergenic foods, or the dose required.(1) All infants should aim to consume about 2g of peanut protein and well-cooked egg per week; parents of high-risk infants should give these amounts more diligently. Given the benefit observed for peanut and egg, it is reasonable for all weaning infants to additionally incorporate 2g of other common and nutritious food allergens; cow’s milk (e.g. as yoghurt), wheat, fish and sesame.Whether children should undergo allergy testing and/or have their first feed of peanut under medical supervision is contested. This cautious approach, potentially requiring large numbers of children to access specialist allergy care, must be balanced against the risks of severe allergic reaction, particularly as most allergic reactions occur on first oral exposure. RCTs of OTI using whole foods had no cases of anaphylaxis on first exposure (4, 6) although anaphylaxis has occurred to OTI using pasteurised whole egg powder.(7) Children with no personal food allergy risk factors do not require testing prior to, or medical supervision during, their first consumption of peanut or well-cooked egg. Children with moderate to severe eczema, or with an existing food allergy should undergo allergy testing +/- OFC at a specialist allergy centre(8), if doing so would not cause undue delay to OTI. It is likely that rapid access to allergy services will be further compromised as a consequence of the COVID-19 pandemic. It may however be that access to SpIgE is available through GP or paediatrician which, if ≥0.35KiU/L, will require referral for OFC. If negative (<0.35KiU/L) the food may be introduced at home following precautionary measures for the first feed: child is well; parent is aware of the signs of IgE mediated reaction has, access to medical support if required and age-appropriate form of the food is given incrementally (Figure 1).
Adolescent and young adult (AYA) patients need additional support while they experience the challenges associated with their age. They need specific training to learn the knowledge and skills required to confidently self-manage their allergies and/or asthma. Transitional care is a complex process which should address the psychological, medical, educational and vocational needs of AYA in the developmentally appropriate way. The European Academy of Allergy and Clinical Immunology has developed a clinical practice guideline to provide evidence-based recommendations for healthcare professionals to support the transitional care of AYA with allergy and/or asthma. This guideline was developed by a multi-disciplinary working panel of experts and patient representatives based on two recent systematic reviews. It sets out a series of general recommendations on operating a clinical service for AYA, which include: (i) starting transition early (11-13 years), (ii) using a structured, multidisciplinary approach, (iii) ensuring AYA fully understand their condition and have resources they can access, (iv) active monitoring of adherence and (v) discussing any implications for further education and work. Specific allergy and asthma transition recommendations include (i) simplifying medication regimes and using reminders; (ii) focusing on areas where AYA are not confident and involving peers in training AYA patients; (iii) identifying and managing psychological and socioeconomic issues impacting disease control and quality of life; (iv) enrolling the family in assisting AYA to undertake self-management and (v) encouraging AYA to let their friends know about their allergies and asthma. These recommendations may need to be adapted to fit into national healthcare systems.