Secondary household transmission of SARS-CoV-2 among children and adolescents: Clinical and epidemiological aspects.

OBJECTIVE: To evaluate the secondary attack rate (SAR) in children and adolescents, contacts of essential activities workers who were infected by SARS-CoV-2; and to describe associated clinical and epidemiological data. METHODS: A cross-sectional study conducted in children and adolescents aged 5 to 19 years of age, that were household contacts of parents and other relatives who were infected by SARS-CoV-2 in the city of Goiânia, Central Brazil, from March to October 2020. Sociodemographic and clinical data were collected from all participants. Nasopharyngeal and oropharyngeal swabs were collected and tested for SARS-CoV-2 RNA using real-time reverse transcription polymerase chain reaction (RT-PCR). Factors associated with SARS-CoV-2 infection and SAR were analyzed using Poisson regression. RESULTS: A total of 267 children and adolescents were investigated. The prevalence of SARS-CoV-2 RNA by the real-time RT-PCR test and/or the presence of COVID-19 associated symptoms (anosmia/ageusia and flu syndrome) was 25.1% (95.0% Confidence Interval [95.0% CI] = 20.3-30.6). More than half (55.1%) of the participants had sygns and symptoms. The most prevalent signs and symptoms in positive individuals were nasal congestion (62.7%), headache (55.2%), cough (50.8%), myalgia (47.8%), runny nose (47.8%), and anosmia (47.8%). The Poisson model showed that the following signs or symptoms were associated with SARS-CoV-2 infection: fever, nasal congestion, decreased appetite, nausea, anosmia, and ageusia. Families that had more than one infected adult, in addition to the index case, presented greater transmissibility to children and adolescents. CONCLUSIONS: Our results contribute to the hypothesis that children and adolescents are not important sources of transmission of SARS-CoV-2 in the home environment during a period of social distancing and school closure; even though they are susceptible to infection in the household (around » of our study population).

Intranasal Dexmedetomidine Compared to a Combination of Intranasal Dexmedetomidine with Ketamine for Sedation of Children Requiring Dental Treatment: A Randomized Clinical Trial.

Outpatient pediatric sedation is challenging. This study aimed to test intranasal dexmedetomidine efficacy as a single drug or combined with ketamine (DK) to sedate children undergoing dental treatment. Children < 7 years were randomized into dexmedetomidine 2 mcg/kg and ketamine 1 mg/kg (DK) or dexmedetomidine 2.5 mcg/kg (D) groups. Videos from the dental sedation allowed the systematic assessment of children's behavior (primary outcome) according to the Ohio State University Behavioral Rating Scale (OSUBRS). Secondary outcomes were parental and dentist satisfaction, adverse events, and recovery time. The data were analyzed descriptively and through regression models. Participants were 88 children (44 per group; 50 boys). The duration of quiet behavior (OSUBRS) was higher than 50% (DK mean 58.4 [standard deviation 38.1]; D 55.2 [39.1]; p = 0.225). Parents (DK 78.0 [32.2]; D 72.7 [35.1]; p = 0.203) and dentists (KD 62.7 [41.0]; D 62.8 [40.1]; p = 0.339) were overall satisfied. Adverse events occurred in 16 cases (DK n = 10, 62.5%; D n= 6, 37.5%; p = 0.104) and were minor. The median recovery time in the DK group was 1.3 times greater than in group D (p < 0.05). Intranasal sedation with dexmedetomidine alone is equally efficacious and satisfactory for pediatric sedation with fewer adverse events and faster recovery than the DK combination.

Structure Formation and Coupling Reactions of Hexaphenylbenzene and Its Brominated Analog.

The on-surface coupling of the prototypical precursor molecule for graphene nanoribbon synthesis, 6,11-dibromo-1,2,3,4-tetraphenyltriphenylene (C42 Br2 H26 , TPTP), and its non-brominated analog hexaphenylbenzene (C42 H30 , HPB), was investigated on coinage metal substrates as a function of thermal treatment. For HPB, which forms non-covalent 2D monolayers at room temperature, a thermally induced transition of the monolayer's structure could be achieved by moderate annealing, which is likely driven by π-bond formation. It is found that the dibrominated carbon positions of TPTP do not guide the coupling if the growth occurs on a substrate at temperatures that are sufficient to initiate C-H bond activation. Instead, similar one-dimensional molecular structures are obtained for both types of precursors, HPB and TPTP.

Manipulation of the molecular spin crossover transition of Fe(H2B(pz)2)2(bipy) by addition of polar molecules.

The addition of various dipolar molecules is shown to affect the temperature dependence of the spin state occupancy of the much studied spin crossover Fe(II) complex, [Fe{H2B(pz)2}2(bipy)] (pz = pyrazol-1-yl, bipy = 2,2'-bipyridine). Specifically, the addition of benzimidazole results in a re-entrant spin crossover transition, i.e. the spin state starts in the mostly low spin state, then high spin state occupancy increases, and finally the high spin state occupancy decreases with increasing temperature. This behavior contrasts with that observed when the highly polar p -benzoquinonemonoimine zwitterion C6H2(…NH2)2(…O)2 was mixed with [Fe{H2B(pz)2}2(bipy)], which resulted in locking [Fe{H2B(pz)2}2(bipy)] largely into a low spin state while addition of the ethyl derivative C6H2(…NHC2H5)2(…O)2 did not appear to perturb the spin crossover transition of [Fe{H2B(pz)2}2(bipy)].

Impact of an Innovative Securement Dressing and Tourniquet in Peripheral Intravenous Catheter-Related Complications and Contamination: An Interventional Study.

Reusable tourniquets and conventional securement dressings are considered risk factors for the occurrence of reported complications and catheter-related bloodstream infections. This study's purpose is to assess the impact of single-use disposable tourniquets and advanced occlusive polyurethane dressings with reinforced cloth borders on peripheral intravenous catheter (PIVC)-related complications and contamination. A pre- and post-interventional prospective observational study was conducted in a cardiology ward of a tertiary hospital between April 2018 and February 2019. Overall, demographic and clinical data from 156 patients and PIVC-related outcomes were collected (n = 296) as well as PIVC tips for microbiological analysis (n = 90). In the pre-intervention phase (n = 118), complication rates of 62.1% were reported, while 44.1% of the PIVCs were contaminated (n = 34). In the post-intervention phase (n = 178), complication rates decreased to 57.3%, while contamination rates significantly decreased to 17.9% (p = 0.014; n = 56). Through a logistic regression, it was found that the use of innovative technologies reduces the chance of PIVC contamination by 79% (odds ratio (OR): 0.21; 95% confidence interval (CI): 0.05-0.98; p = 0.046). Meanwhile, PIVC-related complications and fluid therapy emerged as predictors for PIVC contamination. Findings suggest that the adoption of these innovative devices in nurses' practice contributes to the significant reduction of PIVC contamination.

On-Surface Synthesis and Spectroscopic Characterization of Laterally Extended Chevron Graphene Nanoribbons.

We report the on-surface synthesis and spectroscopic study of laterally extended chevron graphene nanoribbons (GNRs) and compare them with the established chevron GNRs, emphasizing the consistency of bandgap reduction of semiconducting GNRs with increased width. The laterally extended chevron GNRs grown on Au(111) exhibit a bandgap of about 2.2 eV, which is considerably smaller than the values reported for chevron GNRs in similar studies.

Dense monolayer films of atomically precise graphene nanoribbons on metallic substrates enabled by direct contact transfer of molecular precursors.

Atomically precise graphene nanoribbons (GNRs) of two types, chevron GNRs and N = 7 straight armchair GNRs (7-AGNRs), have been synthesized through a direct contact transfer (DCT) of molecular precursors on Au(111) and gradual annealing. This method provides an alternative to the conventional approach for the deposition of molecules on surfaces by sublimation and simplifies preparation of dense monolayer films of GNRs. The DCT method allows deposition of molecules on a surface in their original state and then studying their gradual transformation to polymers to GNRs by scanning tunneling microscopy (STM) upon annealing. We performed STM characterization of the precursors of chevron GNRs and 7-AGNRs, and demonstrate that the assemblies of the intermediates of the GNR synthesis are stabilized by π-π interactions. This conclusion was supported by the density functional theory calculations. The resulting monolayer films of GNRs have sufficient coverage and density of nanoribbons for ex situ characterization by spectroscopic methods, such as Raman spectroscopy, and may prove useful for the future GNR device studies.

Locking and Unlocking the Molecular Spin Crossover Transition.

The Fe(II) spin crossover complex [Fe{H2 B(pz)2 }2 (bipy)] (pz = pyrazol-1-yl, bipy = 2,2'-bipyridine) can be locked in a largely low-spin-state configuration over a temperature range that includes temperatures well above the thermal spin crossover temperature of 160 K. This locking of the spin state is achieved for nanometer thin films of this complex in two distinct ways: through substrate interactions with dielectric substrates such as SiO2 and Al2 O3 , or in powder samples by mixing with the strongly dipolar zwitterionic p-benzoquinonemonoimine C6 H2 (-⋯ NH2 )2 (-⋯ O)2 . Remarkably, it is found in both cases that incident X-ray fluences then restore the [Fe{H2 B(pz)2 }2 (bipy)] moiety to an electronic state characteristic of the high spin state at temperatures of 200 K to above room temperature; that is, well above the spin crossover transition temperature for the pristine powder, and well above the temperatures characteristic of light- or X-ray-induced excited-spin-state trapping. Heating slightly above room temperature allows the initial locked state to be restored. These findings, supported by theory, show how the spin crossover transition can be manipulated reversibly around room temperature by appropriate design of the electrostatic and chemical environment.

Epitaxial growth of aligned atomically precise chevron graphene nanoribbons on Cu(111).

Atomically precise chevron graphene nanoribbons (GNRs) have been synthesized on Cu(111) substrates by the surface-assisted coupling of 6,11-dibromo-1,2,3,4-tetraphenyltriphenylene (C42Br2H26) and thermal cyclodehydrogenation of the resulting polymer. The GNRs form on Cu(111) epitaxially along the 〈112〉 crystallographic directions, which was found to be in agreement with the computational results, and at lower temperatures than on Au(111). This work demonstrates that the substrate plays an important role in the on-surface synthesis of GNRs and can result in new assembly modes of GNR structures.

Graphene-like Boron-Carbon-Nitrogen Monolayers.

A strategy to synthesize a 2D graphenic but ternary monolayer containing atoms of carbon, nitrogen, and boron, h-BCN, is presented. The synthesis utilizes bis-BN cyclohexane, B2N2C2H12, as a precursor molecule and relies on thermally induced dehydrogenation of the precursor molecules and the formation of an epitaxial monolayer on Ir(111) through covalent bond formation. The lattice mismatch between the film and substrate causes a strain-driven periodic buckling of the film. The structure of the film and its corrugated morphology is discussed based on comprehensive data from molecular-resolved scanning tunneling microscopy imaging, X-ray photoelectron spectroscopy, low-energy electron diffraction, and density functional theory. First-principles calculations further predict a direct electronic band gap that is intermediate between gapless graphene and insulating h-BN.

Controversies Regarding the Psychometric Properties of the Brief COPE: The Case of the Brazilian-Portuguese Version "COPE Breve".

The Brief Coping Orientation to Problems Experienced (COPE) inventory investigates the different ways in which people respond to stressful situations. Knowledge is lacking regarding the coping strategies and styles of people in developing countries, including Brazil. This study aimed to adapt and validate the Brief COPE to Brazilian Portuguese (named COPE Breve) by focusing on dispositional coping. For the cross-cultural adaptation, the original Brief COPE in English (28 items grouped into 14 subscales) was adapted according to a universalistic approach, following these steps: translation, synthesis, back-translation, analysis by an expert panel, and pretest with 30 participants. Then, 237 adults from the community health service responded to the COPE Breve. Psychometric analyses included reliability and exploratory factor analysis. Most of the 14 subscales from the original Brief COPE exhibited problems related to internal consistency. A Velicer's minimum average partial test (MAP) was performed and pointed out 3 factors. Exploratory factor analysis produced a revised 20-item version with a 3-factor solution: religion and positive reframing, distraction and external support. The psychometric properties of the COPE Breve with three factors were appropriate. Limitations of this study as well as suggestions for future studies are presented. The COPE Breve should be used in Brazilian clinics and investigations, but divergences in its psychometrics should be further explored in other contexts.

Memory effects of sedative drugs in children and adolescents--protocol for a systematic review.

BACKGROUND: Some sedatives used in children and adolescents can affect memory function. Memory impairment of traumatic experience can minimize the chance of future psychological trauma. Knowledge about the potential of different sedatives to produce amnesia can help in the decision-making process of choosing a sedative regimen. The aim of this systematic review is to evaluate the effect of different sedatives on memory of perioperative events in children and adolescents. METHODS/DESIGN: Electronic databases and other sources, such as trial registers, gray literature, and conference abstracts will be searched. Randomized controlled trials will be included that assess memory of perioperative events in children and adolescents 2-19 years old receiving sedative drugs as premedication or as agents for procedural sedation in a medical or dental settings. The outcomes will be loss of memory after and before sedative administration (anterograde and retrograde amnesia). Two independent reviewers will perform screening, study selection, and data extraction. Disagreement at all levels will be resolved by consensus or by involving a third reviewer. Assessment of the risk of bias of included studies will be performed according to "Cochrane Collaboration's Tool for Assessing Risk of Bias in Randomized Trials." Clinical and methodological heterogeneity across studies will be evaluated to determine if it is possible to combine or not combine study results in a meta-analysis. DISCUSSION: To the best of our knowledge, there is no systematic review that specifically addresses this question. Findings from the review will be useful in the decision-making process about the best sedative for minimizing recall of the medical/dental event and possible psychological trauma. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42015017559.

Mucoid and nonmucoid Burkholderia cepacia complex bacteria in cystic fibrosis infections.

RATIONALE: infection with Burkholderia cepacia complex (BCC) bacteria in cystic fibrosis (CF) is associated with an unpredictable rate of pulmonary decline. Some BCC, but not others, elaborate copious mucoid exopolysaccharide, endowing them with a gross mucoid phenotype, the clinical significance of which has not been described. OBJECTIVES: to determine whether there was a correlation between bacterial mucoid phenotype, as assessed in a semiquantitative manner from plate culture, and severity of disease as assessed by the rate of decline in lung function. METHODS: we performed a retrospective clinical review of 100 patients with CF attending the Vancouver clinics between 1981 and 2007 and analyzed the rate of lung function decline (% predicted FEV(1)). MEASUREMENTS AND MAIN RESULTS: patients infected exclusively with nonmucoid BCC had a more rapid decline in lung function (annual FEV(1) change, -8.51 ± 2.41%) than those infected with mucoid bacteria (-3.01 ± 1.09%; P < 0.05). Linear mixed-effects data modeling revealed a statistically significant inverse association between semiquantitative mucoid exopolysaccharide production and rate of decline of lung function. In vitro incubation of BCC with ceftazidime and ciprofloxacin but not meropenem caused conversion of BCC from mucoid to nonmucoid. CONCLUSIONS: our data suggest an inverse correlation between the quantity of mucoid exopolysaccharide production by BCC bacteria and rate of decline in CF lung function. Certain antibiotics may induce a change in bacterial morphology that enhances their virulence. A simple in vitro test of bacterial mucoidy may be useful in predicting the rate of decline of respiratory function in CF.

Dental sedation by dentists: a view from anesthesiologists working in central Western Brazil.

BACKGROUND: Anesthesia care has been provided by diverse health professionals worldwide, but little is known about anesthesiologists' views about this. Using a survey, we sought the opinions of a group of Brazilian anesthesiologists regarding nitrous oxide/oxygen and oral minimal/moderate sedation performed by dentists. METHODS: A 3-part postal questionnaire was sent to 206 physician anesthesiologists working in the state of Goias, in Central Western Brazil. Part 1 consisted of 4 questions describing respondents' characteristics: gender, time elapsed since completion of the residency program, and experience in providing sedation and general anesthesia for dental treatment. In Part 2, respondents were asked to give their opinions on 11 statements about sedation performed by dentists. Possible responses ranged from total disagreement to total agreement (minimum score = 11 and maximum score = 55). Part 3 was a section for general comments. Data were analyzed by k-means clusters, chi(2), and Student's t-test. RESULTS: The response rate was 53.8% (111 questionnaires). Most anesthesiologists (85.6%) had rarely or never provided sedation or general anesthesia for dental treatment, and 92.8% disagreed with the statement that dentists can administer moderate sedation in the dental office. Two clusters representing more favorable (n = 21) or less favorable (n = 90) opinions were established. Anesthesiologists in the "less favorable" group had more experience with dental sedation (P = 0.006) and dental general anesthesia (P = 0.008) than those in the "more favorable" group. Gender and time elapsed since residency completion did not significantly affect anesthesiologists' opinions. CONCLUSIONS: Many anesthesiologists in Central Western Brazil do not sedate dental patients and are not confident that dentists are able to do it. Dental sedation is an issue that still needs to be clarified in this region; the respective roles of physicians and dentists need to be determined to benefit the population.

[Clinical findings observed in rabbits, meat type, infected experimentally by Cystoisospora felis (Wenyon, 1923) Frenkel, 1977 (Apicomplexa: Cystoisosporinae)]. / Alterações clínicas observadas em coelhos, tipo carne, infectados experimentalmente com Cystoisospora felis (Wenyon, 1923) Frenkel, 1977 (Apicomplexa: Cystoisosporinae).

Twenty four rabbits type meat, cross-breed of White New Zealand and California, of both sexes, with age of 58 days old, and average weight of 1,586 g were used. Than, they were divided in three groups of eight rabbits each. The first group was inoculated orally, in two serial days, with 10(6) sporulated oocysts of Cystoisospora felis per animal, second group was considered per feed, and thirty group was left as control. Clinical signs as body weight, feed consumption, rectal temperature, and breathing frequency were taken daily. Carcasses weights were taking at 2, 4, 6, 8, 9, 16, 22 and 29 days after infection (DAI) when they were posted. In the first DAI, anorexia, slow movements, low percent of food consumption (85.76%), and of alimentary conversion were observed. Difference of 3.52% in the food consumption was observed between control and infected animals. The inoculated rabbits had high temperatures in the first DAI in comparison to controls and per fed animals (p<0.01) at 2nd and at 4th DAI. In relationship to the weight gain in the 1st week the carcasses of the infected rabbits had minimal difference in comparison to control animals. As conclusion, cystoisosporosis, beside clinical signs, can be interfered in the development of the rabbit.

[Rotavirus A infections and reinfections: genotyping and vaccine implications]. / Infecções e reinfecções por Rotavirus A: genotipagem e implicações vacinais.

OBJECTIVE: To identify rotavirus A and the most prevalent G and P genotypes in children with acute diarrhea, and to the describe the occurrence of rotavirus infection and reinfection. METHODS: Group A rotavirus specimens were obtained from fecal samples from children with acute diarrhea in Goiânia, state of Goiás, Brazil from July 2000 to October 2002. Rotavirus A positive children and a control group (children of the same age and sex, without diarrhea and with no evidence of rotavirus in the first fecal samples) were followed prospectively during one year. All rotavirus A positive samples were genotyped using RT-PCR/nested-PCR. RESULTS: A total of 77 group A rotavirus strains (37.2%) were identified in the diarrheic samples of 207 children. The following G genotypes were identified: G1 (62.3%), G9 (34.4%) and G4 (3.3%). With regard to P genotyping, 59% were characterized as P[8], 7.7% as P[6], 23.1% as P[6]+P[8], 7.7% as P[4]+P[8] and 2.6% as P[4]+P[8]. The following associations were observed: G1P[8] (77.8%), G9P[8] (11.1%), G4P[8] (5.6%) and G1P[6] (5.6%). No reinfection was observed in the 40 rotavirus A (+) children. However, but two of 40 children who were initially negative for this agent developed rotavirus infection during the same period. CONCLUSIONS: The predominant G and P genotypes observed were similar to those found in new vaccines. No reinfection occurred during one-year of follow-up for any of the genotypes identified.

Infecções e reinfecções por Rotavirus A: genotipagem e implicações vacinais / Rotavirus A infections and reinfections: genotyping and vaccine implications

OBJETIVOS: Identificar Rotavirus A em crianças com diarréia aguda, determinando os genótipos G e P prevalentes e avaliar a ocorrência de infecções e reinfecções por rotavírus do grupo A em crianças. MÉTODOS: Foram estudadas, prospectivamente, crianças com doença diarréica aguda e identificação de Rotavirus A em Goiânia (GO), durante o período de julho de 2000 a outubro de 2002. Igual número de crianças, pareadas por idade e sexo, que não apresentavam diarréia aguda e sem identificação de rotavírus nas amostras fecais à admissão ao estudo, representou o grupo controle. Foram analisadas a ocorrência de infecções ou reinfecções sintomáticas ou assintomáticas por rotavírus durante o período de estudo, durante um ano de seguimento em ambos os grupos. Todas as amostras positivas foram submetidas a genotipagem G e P através das reações de RT-PCR e Nested PCR. RESULTADOS: A infecção por rotavírus ocorreu em 37,2 por cento (77 de 207 amostras fecais) das crianças com diarréia aguda durante o período do estudo. Os genótipos G e P identificados foram, simultaneamente: G1 (62,3 por cento), G9 (34,4 por cento) e G4 (3,3 por cento) e P[8] (59 por cento), P[6] (7,7 por cento), P[6]+P[8] (23,1 por cento), P[4]+P[8] (7,7 por cento) e P[4]+P[6] (2,6 por cento). As associações de genótipos G e P identificados durante o estudo foram: G1P[8] (77,8 por cento), G9P[8] (11,1 por cento), G4P[8] (5,6 por cento) e G1P[6] (5,6 por cento). Não houve reinfecção por rotavírus nos pacientes do grupo Rotavirus A (+) durante o período de seguimento, enquanto duas crianças do grupo controle apresentaram infecções sintomáticas por rotavírus durante o mesmo período. CONCLUSÕES: Os genótipos G e P predominantes correspondem aos das candidatas atuais à vacina contra rotavírus. Não houve reinfecção por rotavírus pelo período de um ano em relação a todos os genótipos identificados.