How delocalized are the polyacenes?

In an attempt to quantify electron delocalization in polyacenes with up to 50 carbon atoms, we have performed self-consistent field calculations in which the π electrons are constrained to occupy highly localized molecular orbitals (HILOs) centered on a maximum of two, six or ten adjacent carbon atoms. We have also performed similar calculations on simple polyacene analogs consisting only of hydrogen atoms and exhibiting electron delocalization in the σ framework. We find that the energetic cost of localizing the π electrons in the polyacenes is roughly 60, 5 or 0.1 kJ/mol per ring atom for the two-, six- and ten-atom HILOs, respectively, and the use of these localized models overestimates the predicted hydrogenation energies of the acenes by roughly 50%, 4% and 0.1%, respectively. We conclude that the chemistry of polyacenes can be modeled well using highly localized descriptions of the π electrons.

Hemoglobin Threshold for Blood Transfusion in Young Children Hospitalized with Iron Deficiency Anemia.

Current recommendations advise against blood transfusion in hemodynamically stable children with iron deficiency anemia. In an observational study of 125 children aged 6 through 36 months, hospitalized with iron deficiency anemia, we found that hemoglobin level predicted red blood cell transfusion (area under the curve 0.8862). A hemoglobin of 39 g/L had sensitivity 92% and specificity 72% for transfusion.

Emerging use of air eDNA and its application to forensic investigations - A review.

Biological material is routinely collected at crime scenes and from exhibits and is a key type of evidence during criminal investigations. Improvements in DNA technologies allow collection and profiling of trace samples, comprised of few cells, significantly expanding the types of exhibits targeted for DNA analysis to include touched surfaces. However, success rates from trace and touch DNA samples tend to be poorer compared to other biological materials such as blood. Simultaneously, there have been recent advances in the utility of environmental DNA collection (eDNA) in identification and tracking of different biological organisms and species from bacteria to naked mole rats in different environments, including, soil, ice, snow, air and aquatic. This paper examines the emerging methods and research into eDNA collection, with a special emphasis on the potential forensic applications of human DNA collection from air including challenges and further studies required to progress implementation.

Up in the air: Presence and collection of DNA from air and air conditioner units.

Biological material is routinely collected at crime scenes and from exhibits and is a key type of evidence during criminal investigations. Touch or trace DNA samples from surfaces and objects deemed to have been contacted are frequently collected. However, a person of interest may not leave any traces on contacted surfaces, for example, if wearing gloves. A novel means of sampling human DNA from air offers additional avenues for DNA collection. In the present study, we report on the results of a pilot study into the prevalence and persistence of human DNA in the air. The first aspect of the pilot study investigates air conditioner units that circulate air around a room, by sampling units located in four offices and four houses at different time frames post-cleaning. The second aspect investigates the ability to collect human DNA from the air in rooms, with and without people, for different periods of time and with different types of collection filters. Results of this pilot study show that human DNA can be collected on air conditioner unit surfaces and from the air, with air samples representing the more recent occupation while air conditioner units showing historic use of the room.

Neurological involvement in hospitalized children with SARS-CoV-2 infection: a multinational study.

BACKGROUND AND OBJECTIVES: Neurological involvement associated with SARS-CoV-2 infection is increasingly recognized. However, the specific characteristics and prevalence in pediatric patients remain unclear. The objective of this study was to describe the neurological involvement in a multinational cohort of hospitalized pediatric patients with SARS-CoV-2. METHODS: This was a multicenter observational study of children <18 years of age with confirmed SARS-CoV-2 infection or multisystemic inflammatory syndrome (MIS-C) and laboratory evidence of SARS-CoV-2 infection in children, admitted to 15 tertiary hospitals/healthcare centers in Canada, Costa Rica, and Iran February 2020-May 2021. Descriptive statistical analyses were performed and logistic regression was used to identify factors associated with neurological involvement. RESULTS: One-hundred forty-seven (21%) of 697 hospitalized children with SARS-CoV-2 infection had neurological signs/symptoms. Headache (n = 103), encephalopathy (n = 28), and seizures (n = 30) were the most reported. Neurological signs/symptoms were significantly associated with ICU admission (OR: 1.71, 95% CI: 1.15-2.55; p = 0.008), satisfaction of MIS-C criteria (OR: 3.71, 95% CI: 2.46-5.59; p < 0.001), fever during hospitalization (OR: 2.15, 95% CI: 1.46-3.15; p < 0.001), and gastrointestinal involvement (OR: 2.31, 95% CI: 1.58-3.40; p < 0.001). Non-headache neurological manifestations were significantly associated with ICU admission (OR: 1.92, 95% CI: 1.08-3.42; p = 0.026), underlying neurological disorders (OR: 2.98, 95% CI: 1.49-5.97, p = 0.002), and a history of fever prior to hospital admission (OR: 2.76, 95% CI: 1.58-4.82; p < 0.001). DISCUSSION: In this study, approximately 21% of hospitalized children with SARS-CoV-2 infection had neurological signs/symptoms. Future studies should focus on pathogenesis and long-term outcomes in these children.

Understanding the Meat-Masculinity Link: Traditional and Non-Traditional Masculine Norms Predicting Men's Meat Consumption.

Conformity to masculinity ideology predicts men's meat consumption and willingness to reduce their meat intake, but it is unknown which specific masculine norms account for these relationships. This study investigated which traditional and non-traditional masculine norms predict meat consumption, red and processed meat consumption, and willingness to reduce meat consumption in 557 Australian and English males. Men who support the use of physical violence and place high importance on sex ate more meat. Willingness to reduce was highest among men with gender egalitarian views. Targeting these specific masculine norms may be important for mitigating men's overconsumption of meat.

SARS-CoV-2 infection in technology-dependent children: a multicenter case series.

PURPOSE: The objective of this study was to describe the clinical course and outcomes in children with technology dependence (TD) hospitalized with SARS-CoV-2 infection. METHODS: Seventeen pediatric hospitals (15 Canadian and one each in Iran and Costa Rica) included children up to 17 years of age admitted February 1, 2020, through May 31, 2021, with detection of SARS-CoV-2. For those with TD, data were collected on demographics, clinical course and outcome. RESULTS: Of 691 children entered in the database, 42 (6%) had TD of which 22 had feeding tube dependence only, 9 were on supplemental oxygen only, 3 had feeding tube dependence and were on supplemental oxygen, 2 had a tracheostomy but were not ventilated, 4 were on non-invasive ventilation, and 2 were on mechanical ventilation prior to admission. Three of 42 had incidental SARS-CoV-2 infection. Two with end-stage underlying conditions were transitioned to comfort care and died. Sixteen (43%) of the remaining 37 cases required increased respiratory support from baseline due to COVID-19 while 21 (57%) did not. All survivors were discharged home. CONCLUSION: Children with TD appear to have an increased risk of COVID-19 hospitalization. However, in the absence of end-stage chronic conditions, all survived to discharge.

Economical Models for Electron Densities.

We discuss a new theoretical framework for modeling molecular electron densities. Our approach decomposes the total density into contributions from basis function products and then approximates each product using constrained least-squares approximation in a tailored local basis of functions with adjustable non-linear parameters. We show how to solve directly for the expansion coefficients and Lagrange multipliers and present an iterative method to optimize the non-linear parameters. Example products from the Dunning cc-pVTZ basis set are discussed.

Avoiding Negligible Shell Pairs and Quartets in Electronic Structure Calculations.

We define a significant shell pair in an electronic structure calculation as one that generates at least one two-electron integral larger than a preset threshold. We define a significant shell quartet similarly. We then explore several methods for identifying nonsignificant pairs and quartets so that they can be avoided and computational efficiency improved. We find that the widely used Cauchy-Schwarz bound identifies most nonsignificant quartets but that the Hölder bound is slightly more powerful for identifying nonsignificant pairs.

Psychosocial treatments for nightmares in adults and children: a systematic review.

BACKGROUND: As nightmares may be a risk factor for, or symptom of, multiple psychological disorders, some researchers suggest that nightmares should be screened, diagnosed, and treated. Treatments for nightmares include trauma-focused Cognitive Behavioural Therapy and Image Rehearsal Therapy, and pharmacological interventions such as prazosin and nitrazepam. As recent research has put into question our current understanding of treatment efficacy, there is a need to systematically review findings related to the effectiveness of nightmare treatments to inform best practice. The current review assessed the efficacy of psychosocial treatments of nightmare in all cohorts. METHODS: A systematic search of four databases for peer reviewed journal articles from 2000 onwards produced 69 (35 RCTs, 34 non-RCTs) eligible articles that underwent narrative synthesis. RESULTS: The results provide strong evidence for exposure and image rehearsal treatments for the reduction of nightmare frequency, severity, and distress, in civilian, military, idiopathic, and posttraumatic stress disorder (PTSD) cohorts. There is emerging evidence that self-guided and brief treatment modalities offer efficient and effective treatment options. There is an urgent need for clinical trials of treatment effectiveness in children. CONCLUSIONS: The results suggest that treatments for nightmares are most effective when they facilitate a sense of control or mastery by directly targeting the nightmare content and/or the client's emotional responses to the nightmare content. TRIAL REGISTRATION: A review protocol was registered with PROSPERO (CRD42020204861).

The quality of paediatric asthma guidelines: evidence underpinning diagnostic test recommendations from a meta-epidemiological study.

BACKGROUND: Asthma is one of the most frequent reasons children visit a general practitioner (GP). The diagnosis of childhood asthma is challenging, and a variety of diagnostic tests for asthma exist. GPs may refer to clinical practice guidelines when deciding which tests, if any, are appropriate, but the quality of these guidelines is unknown. OBJECTIVES: To determine (i) the methodological quality and reporting of paediatric guidelines for the diagnosis of childhood asthma in primary care, and (ii) the strength of evidence supporting diagnostic test recommendations. DESIGN: Meta-epidemiological study of English-language guidelines from the United Kingdom and other high-income countries with comparable primary care systems including diagnostic testing recommendations for childhood asthma in primary care. The AGREE-II tool was used to assess the quality and reporting of the guidelines. The quality of the evidence was assessed using GRADE. RESULTS: Eleven guidelines met the eligibility criteria. The methodology and reporting quality varied across the AGREE II domains (median score 4.5 out of 7, range 2-6). The quality of evidence supporting diagnostic recommendations was generally of very low quality. All guidelines recommended the use of spirometry and reversibility testing for children aged ≥5 years, however, the recommended spirometry thresholds for diagnosis differed across guidelines. There were disagreements in testing recommendations for 3 of the 7 included tests. CONCLUSIONS: The variable quality of guidelines, lack of good quality evidence, and inconsistent recommendations for diagnostic tests may contribute to poor clinician adherence to guidelines and variation in testing for diagnosing childhood asthma.

The quality of diagnostic guidelines for children in primary care: A meta-epidemiological study.

AIM: To determine the quality of paediatric guidelines relevant to diagnosis of three of the most common conditions in primary care: fever, gastroenteritis and constipation. METHODS: We undertook a meta-epidemiological study of paediatric guidelines for fever, gastroenteritis and gastroenteritis. We systematically searched MEDLINE, Embase, Trip Database, Guidelines International Network, the National Guideline Clearinghouse and WHO from February 2011 to September 2022 for guidelines from high-income settings containing diagnostic recommendations. We assessed the quality of guideline reporting for included guidelines using the AGREE II tool. RESULTS: We included 16 guidelines: fever (n = 7); constipation (n = 4) and gastroenteritis (n = 5). The overall quality across the three conditions was graded moderate (median AGREE II score 4.5/7, range 2.5-6.5) with constipation guidelines rated the highest (median 6/7), and fever rated the lowest (median 3.8/7). Major methodological weaknesses included consideration of guideline applicability. Half of the guidelines did not report involving parent representatives, and 56% did not adequately declare or address their competing interests. CONCLUSIONS: Substantial variations exist in the quality of paediatric guidelines related to the diagnosis of primary care presentations. Better quality guidance is needed for general practitioners to improve diagnosis for children in primary care.

Factors Associated with Surgery and Imaging Characteristics in Severe Orbital Infections.

OBJECTIVES: To evaluate risk factors associated with surgical intervention and subperiosteal/orbital abscess in hospitalized children with severe orbital infections. STUDY DESIGN: We conducted a multicenter cohort study of children 2 months to 18 years hospitalized with periorbital or orbital cellulitis from 2009 to 2018 at 10 hospitals in Canada. Clinical details were extracted, and patients were categorized as undergoing surgical or medical-only management. Primary outcome was surgical intervention and the main secondary outcome was clinically important imaging. Logistic regression was used to identify predictors. RESULTS: Of 1579 patients entered, median age was 5.4 years, 409 (25.9%) had an orbital/subperiosteal abscess, and 189 (12.0%) underwent surgery. In the adjusted analysis, the risk of surgical intervention was associated with older age (age 9 to <14: aOR 3.9, 95% CI 2.3-6.6; and age 14 to ≤18 years: aOR 7.0, 95% CI 3.4-14.1), elevated C-reactive protein >120 mg/L (aOR 2.8, 95% CI 1.3-5.9), elevated white blood cell count of 12-20 000/µL (aOR 1.7, 95% CI 1.1-2.6), proptosis (aOR 2.6, 95% CI 1.7-4.0), and subperiosteal/orbital abscess (aOR 5.3, 95% CI 3.6-7.9). There was no association with antibiotic use before hospital admission, sex, presence of a chronic disease, temperature greater than 38.0°C, and eye swollen shut. Complications were identified in 4.7% of patients, including vision loss (0.6%), intracranial extension (1.6%), and meningitis (0.8%). CONCLUSIONS: In children hospitalized with severe orbital infections, older age, elevated C-reactive protein, elevated white blood cell count, proptosis, and subperiosteal/orbital abscess were predictors of surgical intervention.

EEF1A2 pathogenic variant presenting in an infant with failure to thrive and frequent apneas requiring respiratory support.

EEF1A2 is a gene whose protein product, eukaryotic translation elongation factor 1 alpha 2 (eEF1A2), plays an important role in neurodevelopment. Reports of individuals with pathogenic variants in EEF1A2 are rare, with less than 40 individuals reported world-wide, however a common feature is the association of the variant with developmental and epileptic encephalopathy. Thus far, there have been limited reports of other organ systems or body functions affected by variants in this gene. Here, we present a case of a child with EEF1A2-related disorder who presented at 3 months of age with hypotonia, microcephaly, failure to thrive, and respiratory insufficiency with central apneas requiring respiratory support. Our case highlights the notion that the respiratory system may be highly implicated in EEF1A2-related disorder, allowing for better phenotypic characterization of the disorder.

Predictors of severe illness in children with multisystem inflammatory syndrome after SARS-CoV-2 infection: a multicentre cohort study.

BACKGROUND: SARS-CoV-2 infection can lead to multisystem inflammatory syndrome in children (MIS-C). We sought to investigate risk factors for admission to the intensive care unit (ICU) and explored changes in disease severity over time. METHODS: We obtained data from chart reviews of children younger than 18 years with confirmed or probable MIS-C who were admitted to 15 hospitals in Canada, Iran and Costa Rica between Mar. 1, 2020, and Mar. 7, 2021. Using multivariable analyses, we evaluated whether admission date and other characteristics were associated with ICU admission or cardiac involvement. RESULTS: Of 232 children with MIS-C (median age 5.8 yr), 130 (56.0%) were male and 50 (21.6%) had comorbidities. Seventy-three (31.5%) patients were admitted to the ICU but none died. We observed an increased risk of ICU admission among children aged 13-17 years (adjusted risk difference 27.7%, 95% confidence interval [CI] 8.3% to 47.2%), those aged 6-12 years (adjusted risk difference 25.2%, 95% CI 13.6% to 36.9%) or those with initial ferritin levels greater than 500 µg/L (adjusted risk difference 18.4%, 95% CI 5.6% to 31.3%). Children admitted to hospital after Oct. 31, 2020, had numerically higher rates of ICU admission (adjusted risk difference 12.3%, 95% CI -0.3% to 25.0%) and significantly higher rates of cardiac involvement (adjusted risk difference 30.9%, 95% CI 17.3% to 44.4%). At Canadian sites, the risk of ICU admission was significantly higher for children admitted to hospital between December 2020 and March 2021 than those admitted between March and May 2020 (adjusted risk difference 25.3%, 95% CI 6.5% to 44.0%). INTERPRETATION: We observed that age and higher ferritin levels were associated with more severe MIS-C. We observed greater severity of MIS-C later in the study period. Whether emerging SARS-CoV-2 variants pose different risks of severe MIS-C needs to be determined.

Thrombosis and hemorrhage experienced by hospitalized children with SARS-CoV-2 infection or MIS-C: Results of the PICNIC registry.

INTRODUCTION: Coagulopathy and thrombosis associated with SARS-CoV-2 infection are well defined in hospitalized adults and leads to adverse outcomes. Pediatric studies are limited. METHODS: An international multicentered (n = 15) retrospective registry collected information on the clinical manifestations of SARS-CoV-2 and multisystem inflammatory syndrome (MIS-C) in hospitalized children from February 1, 2020 through May 31, 2021. This sub-study focused on coagulopathy. Study variables included patient demographics, comorbidities, clinical presentation, hospital course, laboratory parameters, management, and outcomes. RESULTS: Nine hundred eighty-five children were enrolled, of which 915 (93%) had clinical information available; 385 (42%) had symptomatic SARS-CoV-2 infection, 288 had MIS-C (31.4%), and 242 (26.4%) had SARS-CoV-2 identified incidentally. Ten children (1%) experienced thrombosis, 16 (1.7%) experienced hemorrhage, and two (0.2%) experienced both thrombosis and hemorrhage. Significantly prevalent prothrombotic comorbidities included congenital heart disease (p-value .007), respiratory support (p-value .006), central venous catheter (CVC) (p = .04) in children with primary SARS-CoV-2 and in those with MIS-C included respiratory support (p-value .03), obesity (p-value .002), and cytokine storm (p = .012). Comorbidities prevalent in children with hemorrhage included age >10 years (p = .04), CVC (p = .03) in children with primary SARS-CoV-2 infection and in those with MIS-C encompassed thrombocytopenia (p = .001) and cytokine storm (p = .02). Eleven patients died (1.2%), with no deaths attributed to thrombosis or hemorrhage. CONCLUSION: Thrombosis and hemorrhage are uncommon events in children with SARS-CoV-2; largely experienced by those with pre-existing comorbidities. Understanding the complete spectrum of coagulopathy in children with SARS-CoV-2 infection requires ongoing research.

DFT exchange: sharing perspectives on the workhorse of quantum chemistry and materials science.

In this paper, the history, present status, and future of density-functional theory (DFT) is informally reviewed and discussed by 70 workers in the field, including molecular scientists, materials scientists, method developers and practitioners. The format of the paper is that of a roundtable discussion, in which the participants express and exchange views on DFT in the form of 302 individual contributions, formulated as responses to a preset list of 26 questions. Supported by a bibliography of 777 entries, the paper represents a broad snapshot of DFT, anno 2022.

Research priorities for children with neurological impairment and medical complexity in high-income countries.

AIM: To identify the highest-priority clinical research areas related to children with neurological impairment and medical complexity among clinicians and caregivers. METHOD: A modified, three-stage Delphi study using online surveys and guided by a steering committee was completed. In round 1, clinicians and family caregivers suggested clinical topics and related questions that require research to support this subgroup of children. After refinement of the suggestions by the steering committee, participants contributed to 1 (family caregivers) or 2 (clinicians) subsequent rounds to develop a prioritized list. RESULTS: A diverse international expert panel consisting of 49 clinicians and 12 family caregivers provided 601 responses. Responses were distilled into 26 clinical topics comprising 126 related questions. The top clinical topics prioritized for research were irritability and pain, child mental health, disorders of tone, polypharmacy, sleep, aspiration, behavior, dysautonomia, and feeding intolerance. The clinician expert panel also prioritized 10 specific research questions. INTERPRETATION: Study findings support a research agenda for children with neurological impairment and medical complexity focused on addressing clinical questions, prioritized by an international group of clinicians and caregivers.

Infants hospitalized for acute COVID-19: disease severity in a multicenter cohort study.

Age is the most important determinant of COVID-19 severity. Infectious disease severity by age is typically J-shaped, with infants and the elderly carrying a high burden of disease. We report on the comparative disease severity between infants and older children in a multicenter retrospective cohort study of children 0 to 17 years old admitted for acute COVID-19 from February 2020 through May 2021 in 17 pediatric hospitals. We compare clinical and laboratory characteristics and estimate the association between age group and disease severity using ordinal logistic regression. We found that infants comprised one-third of cases, but were admitted for a shorter period (median 3 days IQR 2-5 versus 4 days IQR 2-7), had a lower likelihood to have an increased C-reactive protein, and had half the odds of older children of having severe or critical disease (OR 0.50 (95% confidence interval 0.32-0.78)).    Conclusion: When compared to older children, there appeared to be a lower threshold to admit infants but their length of stay was shorter and they had lower odds than older children of progressing to severe or critical disease. What is Known: • A small proportion of children infected with SARS-CoV-2 require hospitalization for acute COVID-19 with a subgroup needing specialized intensive care to treat more severe disease. • For most infectious diseases including viral respiratory tract infections, disease severity by age is J-shaped, with infants having more severe disease compared to older children. What is New: • One-third of admitted children for acute COVID-19 during the first 14 months of the pandemic were infants. • Infants had half the odds of older children of having severe or critical disease.

Effectiveness and safety of tranexamic acid in pediatric trauma: A systematic review and meta-analysis.

OBJECTIVE: Trauma is the leading cause of childhood death in the United States. Our goal was to determine the effectiveness of tranexamic acid (TXA) in improving survival in pediatric trauma. METHODS: MEDLINE (OVID), Embase (OVID), Cochrane Central Register databases, CINAHL (EBSCO), Web of Science (Clarivate Analytics), and grey literature sources were searched for publications reporting survival and safety outcomes in children receiving TXA in acute trauma, with no language restrictions, published until February 11, 2021. Two independent researchers assessed studies for eligibility, bias, and quality. Data on the study setting, injury type, participants, design, interventions, TXA dosing and outcomes were extracted. The primary outcome was survival in children who received TXA following trauma. Forest plots of effect estimates were constructed for each study. Heterogeneity was assessed and data were pooled by meta-analysis using a random-effects model. RESULTS: Fourteen articles met inclusion criteria - six single-institution and eight multicentre retrospective cohort studies. Overall, TXA use was not associated with increased survival in pediatric trauma (adjusted odds ratio [aOR]: 0.61, 95% CI: 0.30-1.22) after adjustment for patient-level variables, such as injury severity. Increased survival was documented in the subset of children experiencing trauma in combat settings (aOR for mortality: 0.31, 95% CI: 0.14-0.68). There were no differences in the odds of thromboembolic events (OR 1.15, 95% CI: 0.46-2.87) in children who received TXA versus not. CONCLUSIONS: The utility of TXA in children with trauma is unclear. Guidelines supporting TXA use in pediatric trauma may not be based on the available evidence of its use in this context. Rigorous trials measuring survival and other meaningful outcomes and exploring optimal TXA dosing are urgently needed. Study Registration (PROSPERO): CRD42020157683.