144 research outputs found

    Quantitative considerations in Medium Energy Ion Scattering

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    Due to its unique capability of providing near-quantitative compositional and layer structure information during depth profiling analysis, in favourable cases, with sub-nanometre resolution,medium energy ion scattering (MEIS) is becoming increasingly important to the characterisation of microelectronic device structures in which scaling laws have demanded the growth and doping of layers of nanometre thickness. Here we assess the quantitative accuracy in terms of both depth and concentration, that can be achieved in MEIS depth profiling

    Quantifying the global number of tuberculosis survivors: a modelling study

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    Background People who survive tuberculosis face clinical and societal consequences after recovery, including increased risks of recurrent tuberculosis, premature death, reduced lung function, and ongoing stigma. To describe the size of this issue, we aimed to estimate the number of individuals who developed first-episode tuberculosis between 1980 and 2019, the number who survived to 2020, and the number who have been treated within the past 5 years or 2 years. Methods In this modelling study, we estimated the number of people who survived treated tuberculosis using country-level WHO data on tuberculosis case notifications, excluding those who died during treatment. We estimated the number of individuals surviving untreated tuberculosis using the difference between WHO country-level incidence estimates and notifications, applying published age-stratified and HIV-stratified case fatality ratios. To estimate survival with time, post-tuberculosis life tables were developed for each country-year by use of UN World Population Prospects 2019 mortality rates and published post-tuberculosis mortality hazard ratios. Findings Between 1980 and 2019, we estimate that 363 million people (95% uncertainty interval [UI] 287 million–438 million) developed tuberculosis, of whom 172 million (169 million–174 million) were treated. Individuals who developed tuberculosis between 1980 and 2019 had lived 3480 million life-years (95% UI 3040 million–3920 million) after tuberculosis by 2020, with survivors younger than 15 years at the time of tuberculosis development contributing 12% (95% UI 7–17) of these life-years. We estimate that 155 million tuberculosis survivors (95% UI 138 million–171 million) were alive in 2020, the largest proportion (47% [37–57]) of whom were in the WHO South-East Asia region. Of the tuberculosis survivors who were alive in 2020, we estimate that 18% (95% UI 16–20) were treated in the past 5 years and 8% (7–9) were treated in the past 2 years. Interpretation The number of tuberculosis survivors alive in 2020 is more than ten times the estimated annual tuberculosis incidence. Interventions to alleviate respiratory morbidity, screen for and prevent recurrent tuberculosis, and reduce stigma should be immediately prioritised for recently treated tuberculosis survivors. Funding UK Medical Research Council, the UK Department for International Development, the National Institute for Health Research, and the European and Developing Countries Clinical Trials Partnership

    Delegating Clozapine Monitoring to Advanced Nurse Practitioners:An Exploratory, Randomized Study to Assess the Effect on Prescription and Its Safety

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    To test whether: (1) psychiatrists will prescribe clozapine more often if they can delegate the monitoring tasks to an advanced nurse practitioner (ANP), (2) clozapine monitoring by an ANP is at least as safe as monitoring by a psychiatrist. Patients from 23 Dutch outpatient teams were assessed for an indication for clozapine. ANPs affiliated to these teams were randomized to Condition A: clozapine monitoring by an ANP, or Condition B: monitoring by the psychiatrist. The safety of monitoring was evaluated by determining whether the weekly neutrophil measurements were performed. Staff and patients were blinded regarding the first hypothesis. Of the 173 patients with an indication for clozapine at baseline, only seven in Condition A and four in Condition B were prescribed clozapine (Odds Ratio = 2.24, 95% CI 0.61-8.21; p = 0.225). These low figures affected the power of this study. When we considered all patients who started with clozapine over the 15-month period (N = 49), the Odds Ratio was 1.90 (95% CI 0.93-3.87; p = 0.078). With regard to the safety of the monitoring of the latter group of patients, 71.2% of the required neutrophil measurements were performed in condition A and 67.3% in condition B (OR = 0.98; CI = 0.16-3.04; p = 0.98). Identifying patients with an indication for clozapine does not automatically lead to improved prescription rates, even when an ANP is available for the monitoring. Clozapine-monitoring performed by an ANP seemed as safe as that by a psychiatrist

    Prescription and Underprescription of Clozapine in Dutch Ambulatory Care

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    Purpose: To our knowledge, no study has examined in a structured way the extent of underprescription of clozapine in ambulatory patients with Non-Affective Psychotic Disorder (NAPD). In the Netherlands, psychiatric care for such patients is provided by Flexible Assertive Community Treatment (FACT) teams and by early intervention teams. In 20 FACT teams and 3 early intervention teams we assessed the proportion of patients who: use clozapine (type 1 patients), previously used this drug (type 2), have an unfulfilled indication for this drug, by type of indication (type 3), or were at least markedly psychotic, but had not yet received two adequate treatments with other antipsychotic drugs (type 4). We expected to find major differences between teams. To rule out that these differences are caused by differences in severity of psychopathology, we also calculated the proportions of patients who use clozapine given an indication at any time (number of type 1 patients divided by the sum of type 1, 2, and 3 patients). Materials and methods: The nurse practitioner of each team identified the patients already on clozapine. Next, using a highly-structured decision tree, the nurse practitioner and psychiatrist assessed whether the remaining patients had an indication for this drug. Indications were treatment-resistant positive symptoms, tardive dyskinesia, aggression and suicidality. The severity of positive symptoms was determined using the Clinical Global Impression-Schizophrenia Scale (CGI-SCH). Results: In the participating FACT-teams 2,286 NAPD patients were assessed. The range among teams in proportions was: type 1: 8.8-34.7% (mean: 23.0%), type 2: 0-8.2% (mean: 3.5%), type 3: 1.7-15.6% (mean: 6.9%), type 4: 1.8-16.3% (mean: 8.6%). The range in proportions of patients using this drug given an indication was 49.0-90.9% (mean: 68.8%). These figures were lower in early intervention teams. Conclusions: The proportion of patients in FACT-teams who have an unfulfilled indication for clozapine is 6.9%. There were considerable differences between teams with respect to this proportion. Almost a third of the outpatients had at any time an indication for clozapine. If one takes type 4 patients into account, this proportion may be higher

    Shorter treatment for minimal tuberculosis (TB) in children (SHINE): A study protocol for a randomised controlled trial

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    BACKGROUND: Tuberculosis (TB) in children is frequently paucibacillary and non-severe forms of pulmonary TB are common. Evidence for tuberculosis treatment in children is largely extrapolated from adult studies. Trials in adults with smear-negative tuberculosis suggest that treatment can be effectively shortened from 6 to 4 months. New paediatric, fixed-dose combination anti-tuberculosis treatments have recently been introduced in many countries, making the implementation of World Health Organisation (WHO)-revised dosing recommendations feasible. The safety and efficacy of these higher drug doses has not been systematically assessed in large studies in children, and the pharmacokinetics across children representing the range of weights and ages should be confirmed. METHODS/DESIGN: SHINE is a multicentre, open-label, parallel-group, non-inferiority, randomised controlled, two-arm trial comparing a 4-month vs the standard 6-month regimen using revised WHO paediatric anti-tuberculosis drug doses. We aim to recruit 1200 African and Indian children aged below 16 years with non-severe TB, with or without HIV infection. The primary efficacy and safety endpoints are TB disease-free survival 72 weeks post randomisation and grade 3 or 4 adverse events. Nested pharmacokinetic studies will evaluate anti-tuberculosis drug concentrations, providing model-based predictions for optimal dosing, and measure antiretroviral exposures in order to describe the drug-drug interactions in a subset of HIV-infected children. Socioeconomic analyses will evaluate the cost-effectiveness of the intervention and social science studies will further explore the acceptability and palatability of these new paediatric drug formulations. DISCUSSION: Although recent trials of TB treatment-shortening in adults with sputum-positivity have not been successful, the question has never been addressed in children, who have mainly paucibacillary, non-severe smear-negative disease. SHINE should inform whether treatment-shortening of drug-susceptible TB in children, regardless of HIV status, is efficacious and safe. The trial will also fill existing gaps in knowledge on dosing and acceptability of new anti-tuberculosis formulations and commonly used HIV drugs in settings with a high burden of TB. A positive result from this trial could simplify and shorten treatment, improve adherence and be cost-saving for many children with TB. Recruitment to the SHINE trial begun in July 2016; results are expected in 2020

    Clinical standards for drug-susceptible TB in children and adolescents

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    BACKGROUND: These clinical standards aim to provide guidance for diagnosis, treatment, and management of drug-susceptible TB in children and adolescents. METHODS: Fifty-two global experts in paediatric TB participated in a Delphi consensus process. After eight rounds of revisions, 51/52 (98%) participants endorsed the final document. RESULTS: Eight standards were identified: Standard 1, Age and developmental stage are critical considerations in the assessment and management of TB; Standard 2, Children and adolescents with symptoms and signs of TB disease should undergo prompt evaluation, and diagnosis and treatment initiation should not depend on microbiological confirmation; Standard 3, Treatment initiation is particularly urgent in children and adolescents with presumptive TB meningitis and disseminated (miliary) TB; Standard 4, Children and adolescents should be treated with an appropriate weight-based regimen; Standard 5, Treating TB infection (TBI) is important to prevent disease; Standard 6, Children and adolescents should receive home-based/community-based treatment support whenever possible; Standard 7, Children, adolescents, and their families should be provided age-appropriate support to optimise engagement in care and clinical outcomes; and Standard 8, Case reporting and contact tracing should be conducted for each child and adolescent. CONCLUSION: These consensus-based clinical standards, which should be adapted to local contexts, will improve the care of children and adolescents affected by TB.National Institutes of HealthRevisión por pare

    Parents' experiences of an abnormal ultrasound examination - vacillating between emotional confusion and sense of reality

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    <p>Abstract</p> <p>Background</p> <p>An ultrasound examination is an important confirmation of the pregnancy and is accepted without reflection to any prenatal diagnostic aspects. An abnormal finding often comes unexpectedly and is a shock for the parents. The aim was to generate a theoretical understanding of parents' experiences of the situation when their fetus is found to have an abnormality at a routine ultrasound examination.</p> <p>Methods</p> <p>Sixteen parents, mothers and fathers, whose fetus had been diagnosed with an abnormality during an ultrasound scan in the second or third trimester, were interviewed. The study employed a grounded theory approach.</p> <p>Results</p> <p>The core category <it>vacillating between the emotional confusion and sense of reality </it>is related to the main concern <it>assessment of the diagnosis impact on the well-being of the fetus</it>. Two other categories <it>Entering uncertainty </it>and <it>Involved in an ongoing change and adaptation </it>have each five sub-categories.</p> <p>Conclusions</p> <p>Parents are aware of that ultrasound examination is a tool for identifying abnormalities prenatally. The information about the abnormality initially results in broken expectations and anxiety. Parents become involved in ongoing change and adaptation. They need information about the ultrasound findings and the treatment without prolonged delay and in a suitable environment. The examiner who performs the ultrasound examination must be aware of how anxiety can be intensified by environmental factors. All parents should to be offered a professional person to give them <it>s</it>upport as a part of the routine management of this situation.</p

    Superconductivity in Silicon Nanostructures

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    We present the findings of the superconductivity in the silicon nanostructures prepared by short time diffusion of boron after preliminary oxidation of the n-type Si (100) surface. These Si-based nanostructures represent the p-type high mobility silicon quantum well (Si-QW) confined by the delta - barriers heavily doped with boron. The ESR studies show that the delta - barriers appear to consist of the trigonal dipole centers, B(+)-B(-), which are caused by the negative-U reconstruction of the shallow boron acceptors, 2B(0)=>B(+)-B(-). The temperature and magnetic field dependencies of the resistance, thermo-emf, specific heat and magnetic susceptibility demonstrate that the high temperature superconductivity observed seems to result from the transfer of the small hole bipolarons through these negative-U dipole centers of boron at the Si-QW - delta - barrier interfaces. The value of the superconductor energy gap obtained is in a good agreement with the data derived from the oscillations of the conductance in normal state and of the zero-resistance supercurrent in superconductor state as a function of the bias voltage. These oscillations appear to be correlated by on- and off-resonance tuning the two-dimensional subbands of holes with the Fermi energy in the superconductor delta - barriers. Finally, the proximity effect in the S- Si-QW -S structure is revealed by the findings of the multiple Andreev reflection (MAR) processes and the quantization of the supercurrent

    Assessment of Clinical Outcomes Among Children and Adolescents Hospitalized With COVID-19 in 6 Sub-Saharan African Countries

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    Importance: Little is known about COVID-19 outcomes among children and adolescents in sub-Saharan Africa, where preexisting comorbidities are prevalent. / Objective: To assess the clinical outcomes and factors associated with outcomes among children and adolescents hospitalized with COVID-19 in 6 countries in sub-Saharan Africa. / Design, Setting, and Participants: This cohort study was a retrospective record review of data from 25 hospitals in the Democratic Republic of the Congo, Ghana, Kenya, Nigeria, South Africa, and Uganda from March 1 to December 31, 2020, and included 469 hospitalized patients aged 0 to 19 years with SARS-CoV-2 infection. / Exposures: Age, sex, preexisting comorbidities, and region of residence. / Main Outcomes and Measures: An ordinal primary outcome scale was used comprising 5 categories: (1) hospitalization without oxygen supplementation, (2) hospitalization with oxygen supplementation, (3) ICU admission, (4) invasive mechanical ventilation, and (5) death. The secondary outcome was length of hospital stay. / Results: Among 469 hospitalized children and adolescents, the median age was 5.9 years (IQR, 1.6-11.1 years); 245 patients (52.4%) were male, and 115 (24.5%) had comorbidities. A total of 39 patients (8.3%) were from central Africa, 172 (36.7%) from eastern Africa, 208 (44.3%) from southern Africa, and 50 (10.7%) from western Africa. Eighteen patients had suspected (n = 6) or confirmed (n = 12) multisystem inflammatory syndrome in children. Thirty-nine patients (8.3%) died, including 22 of 69 patients (31.9%) who required intensive care unit admission and 4 of 18 patients (22.2%) with suspected or confirmed multisystem inflammatory syndrome in children. Among 468 patients, 418 (89.3%) were discharged, and 16 (3.4%) remained hospitalized. The likelihood of outcomes with higher vs lower severity among children younger than 1 year expressed as adjusted odds ratio (aOR) was 4.89 (95% CI, 1.44-16.61) times higher than that of adolescents aged 15 to 19 years. The presence of hypertension (aOR, 5.91; 95% CI, 1.89-18.50), chronic lung disease (aOR, 2.97; 95% CI, 1.65-5.37), or a hematological disorder (aOR, 3.10; 95% CI, 1.04-9.24) was associated with severe outcomes. Age younger than 1 year (adjusted subdistribution hazard ratio [asHR], 0.48; 95% CI, 0.27-0.87), the presence of 1 comorbidity (asHR, 0.54; 95% CI, 0.40-0.72), and the presence of 2 or more comorbidities (asHR, 0.26; 95% CI, 0.18-0.38) were associated with reduced rates of hospital discharge. / Conclusions and Relevance: In this cohort study of children and adolescents hospitalized with COVID-19 in sub-Saharan Africa, high rates of morbidity and mortality were observed among infants and patients with noncommunicable disease comorbidities, suggesting that COVID-19 vaccination and therapeutic interventions are needed for young populations in this region

    Protecting children in low-income and middle-income countries from COVID-19

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    CITATION: Ahmed, S. et al. 2020. Protecting children in low-income and middle-income countries from COVID-19. BMJ Global Health, 5:e002844. doi:10.1136/bmjgh-2020-002844.The original publication is available at https://gh.bmj.comA saving grace of the COVID-19 pandemic in high-income and upper middle-income countries has been the relative sparing of children. As the disease spreads across low-income and middle-income countries (LMICs), long-standing system vulnerabilities may tragically manifest, and we worry that children will be increasingly impacted, both directly and indirectly. Drawing on our shared child pneumonia experience globally, we highlight these potential impacts on children in LMICs and propose actions for a collective response.https://gh.bmj.com/content/5/5/e002844.abstractPublisher's versio
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