Chiral Single-Molecule Potentiometers Based on Stapled ortho- Oligo(phenylene)ethynylenes.

We report on the chemical design of chiral molecular junctions with stress-dependent conductance, whose helicity is maintained during the stretching of a single molecule junction due to the stapling of both ends of the inner helix. In the reported compounds, different conductive pathways are observed, with clearly different conductance values and plateau-length distributions, attributed to different conformations of the helical structures. The large chiro-optical responses and the potential use of these molecules as unimolecular spin filters have been theoretically proved using state-of-the-art Density Functional Theory (DFT) calculations, including a fully ab-initio estimation of the CISS-originating spin polarization which is done, for the first time, for a realistic molecular system.

Impact of a supervised training course on spirometry competency for primary care pediatricians.

OBJECTIVE: Spirometry is the most commonly performed lung function test, and performance, adherence to acceptability and repeatability criteria, and accurate interpretation of results help optimize the test's usefulness. This study aimed to measure the effects of spirometry training courses supported by the Italian Pediatric Respiratory Society (IPRS) on primary care pediatricians' (PCP) knowledge of spirometry test quality, ability to interpret results, and overall degree of satisfaction with the course. METHODS: Of the six face-to-face courses, four lasted two days and two lasted one day: mean duration of theoretical lessons was five and four hours respectively; and practical sessions lasted eight and six hours, respectively. At the end of each course, participants took a learning test consisting of evaluating six flow-volume curves. Degree of satisfaction was assessed by asking participants to rank the relevance, quality, and usefulness of the course. RESULTS: 261 PCPs were involved, with most (67.43%) taking two-day courses. Nearly all participants correctly identified normal and restrictive patterns. Intrathoracic large-airway obstruction was the pattern most difficult to identify correctly (70.5% overall), whereas > 80% of the participants correctly classified artifacts, obstructive-restrictive, and obstructive patterns. Participants in longer courses reported significantly higher values on the learning score. The overall degree of satisfaction average ranged between "good" and "excellent". CONCLUSIONS: This pilot study showed the greater impact of two-day courses than one-day courses for training PCPs to properly interpret spirometry, confirming that a practical module lasting at least six hours is sufficient to deliver adequate training on spirometry for healthcare professionals.

Fetal Origins of Asthma: A Longitudinal Study from Birth to Age 36 Years.

Rationale: Deficits in infant lung function-including the ratio of the time to reach peak tidal expiratory flow to the total expiratory time (tptef/te) and maximal expiratory flow at FRC (V̇maxFRC)-have been linked to increased risk for childhood asthma.Objectives: To examine the individual and combined effects of tptef/te and V̇maxFRC in infancy on risk for asthma and abnormalities of airway structure into mid-adult life.Methods: One hundred eighty participants in the Tucson Children's Respiratory Study birth cohort had lung function measured by the chest-compression technique in infancy (mean age ± SD: 2.0 ± 1.2 mo). Active asthma was assessed in up to 12 questionnaires between ages 6 and 36 years. Spirometry and chest high-resolution computed tomographic (HRCT) imaging were completed in a subset of participants at age 26. The relations of infant tptef/te and V̇maxFRC to active asthma and airway structural abnormalities into adult life were tested in multivariable mixed models.Measurements and Main Results: After adjustment for covariates, a 1-SD decrease in infant tptef/te and V̇maxFRC was associated with a 70% (P = 0.001) and 55% (P = 0.005) increased risk of active asthma, respectively. These effects were partly independent, and two out of three infants who were in the lowest tertile for both tptef/te and V̇maxFRC developed active asthma by mid-adult life. Infant V̇maxFRC predicted reduced airflow and infant tptef/te reduced HRCT airway caliber at age 26.Conclusions: These findings underscore the long-lasting effects of the fetal origins of asthma, support independent contributions by infant tptef/te and V̇maxFRC to development of asthma, and link deficits at birth in tptef/te with HRCT-assessed structural airway abnormalities in adult life.

Technical standards for respiratory oscillometry.

Oscillometry (also known as the forced oscillation technique) measures the mechanical properties of the respiratory system (upper and intrathoracic airways, lung tissue and chest wall) during quiet tidal breathing, by the application of an oscillating pressure signal (input or forcing signal), most commonly at the mouth. With increased clinical and research use, it is critical that all technical details of the hardware design, signal processing and analyses, and testing protocols are transparent and clearly reported to allow standardisation, comparison and replication of clinical and research studies. Because of this need, an update of the 2003 European Respiratory Society (ERS) technical standards document was produced by an ERS task force of experts who are active in clinical oscillometry research.The aim of the task force was to provide technical recommendations regarding oscillometry measurement including hardware, software, testing protocols and quality control.The main changes in this update, compared with the 2003 ERS task force document are 1) new quality control procedures which reflect use of "within-breath" analysis, and methods of handling artefacts; 2) recommendation to disclose signal processing, quality control, artefact handling and breathing protocols (e.g. number and duration of acquisitions) in reports and publications to allow comparability and replication between devices and laboratories; 3) a summary review of new data to support threshold values for bronchodilator and bronchial challenge tests; and 4) updated list of predicted impedance values in adults and children.

Official American Thoracic Society Clinical Practice Guidelines: Diagnostic Evaluation of Infants with Recurrent or Persistent Wheezing.

BACKGROUND: Infantile wheezing is a common problem, but there are no guidelines for the evaluation of infants with recurrent or persistent wheezing that is not relieved or prevented by standard therapies. METHODS: An American Thoracic Society-sanctioned guideline development committee selected clinical questions related to uncertainties or controversies in the diagnostic evaluation of wheezing infants. Members of the committee conducted pragmatic evidence syntheses, which followed the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. The evidence syntheses were used to inform the formulation and grading of recommendations. RESULTS: The pragmatic evidence syntheses identified few studies that addressed the clinical questions. The studies that were identified constituted very low-quality evidence, consisting almost exclusively of case series with risk of selection bias, indirect patient populations, and imprecise estimates. The committee made conditional recommendations to perform bronchoscopic airway survey, bronchoalveolar lavage, esophageal pH monitoring, and a swallowing study. It also made conditional recommendations against empiric food avoidance, upper gastrointestinal radiography, and gastrointestinal scintigraphy. Finally, the committee recommended additional research about the roles of infant pulmonary function testing and food avoidance or dietary changes, based on allergy testing. CONCLUSIONS: Although infantile wheezing is common, there is a paucity of evidence to guide clinicians in selecting diagnostic tests for recurrent or persistent wheezing. Our committee made several conditional recommendations to guide clinicians; however, additional research that measures clinical outcomes is needed to improve our confidence in the effects of various diagnostic interventions and to allow advice to be provided with greater confidence.

Paediatrics in Barcelona.

This update will describe the paediatric highlights from the 2013 European Respiratory Society (ERS) annual congress in Barcelona, Spain. Abstracts from the seven groups of the ERS Paediatric Assembly (Respiratory Physiology and Sleep, Asthma and Allergy, Cystic Fibrosis, Respiratory Infection and Immunology, Neonatology and Paediatric Intensive Care, Respiratory Epidemiology, and Bronchology) have been chosen by group officers and are presented in the context of current literature.

Case Report: Epi-endocardial bridges in refractory cavotricuspid isthmus-dependent atrial flutter: technical analysis of epi-endocardial breakthrough.

Background: Typical isthmus-dependent atrial flutter (AFL) is traditionally treated through radiofrequency (RF) ablation to create a bidirectional conduction block across the cavo-tricuspid isthmus (CTI) in the right atrium. While this approach is successful in many cases, certain anatomical variations can present challenges, making CTI ablation difficult. Methods: We enrolled four patients with typical counter-clockwise AFL who displayed an epicardial bridge at the CTI. Patients underwent high-resolution mapping of the right atrium and CTI ablation. Results: Post-mapping identified areas of early focal activation outside the lesion line which suggested the presence of an epi-endocardial bridge with an endocardial breakthrough, confirmed by recording a unipolar rS pattern on electrograms at that site. A stable CTI block was achieved in all patients only after ablation at the site of the epi-endocardial breakthrough. Conclusions: The presence of an epicardial bridge at the CTI, allowing conduction to persist despite endocardial ablation, should be considered in challenging cases of CTI-dependent AFL. Understanding this phenomenon and utilizing appropriate mapping and ablation techniques are essential for achieving successful and lasting CTI block.

Unravelling the respiratory health path across the lifespan for survivors of preterm birth.

Many survivors of preterm birth will have abnormal lung development, reduced peak lung function and, potentially, an increased rate of physiological lung function decline, each of which places them at increased risk of chronic obstructive pulmonary disease across the lifespan. Current rates of preterm birth indicate that by the year 2040, around 50 years since the introduction of surfactant therapy, more than 700 million individuals will have been born prematurely-a number that will continue to increase by about 15 million annually. In this Personal View, we describe current understanding of the impact of preterm birth on lung function through the life course, with the aim of putting this emerging health crisis on the radar for the respiratory community. We detail the potential underlying mechanisms of prematurity-associated lung disease and review current approaches to prevention and management. Furthermore, we propose a novel way of considering lung disease after preterm birth, using a multidimensional model to determine individual phenotypes of lung disease-a first step towards optimising management approaches for prematurity-associated lung disease.

Paediatrics in Vienna.

The aim of this update is to describe, in the context of the current literature, major papers from the seven groups of the Paediatric Assembly (Respiratory Physiology; Asthma and Allergy; Cystic Fibrosis; Respiratory Infection and Immunology; Neonatology and Paediatric Intensive Care; Respiratory Epidemiology; and Bronchology) presented during the annual European Respiratory Society congress held in 2012 in Vienna, Austria.

Bronchodilator response by interrupter technique to guide management of preschool wheeze.

OBJECTIVE: We examined relationships between clinical features and pulmonary function before and after inhaled corticosteroid (ICS) treatment in wheezy preschool children, and specifically, whether measuring bronchodilator response (BDR) could predict benefit from ICS. DESIGN: Clinical non-randomised intervention study SETTING: Secondary care. PATIENTS: Preschool children (2 years to <6 years) with recurrent wheeze. INTERVENTIONS: Inhaled beta-agonist, ICS. OUTCOME MEASURES: We measured prebronchodilator and postbronchodilator interrupter resistance (Rint) and symptom scores at 0 (V1), 4 (V2) and 12 (V3) weeks. At V2, those with a predetermined symptom level commenced ICS. Modified Asthma Predictive Index (mAPI) and parental perception of response to bronchodilator were recorded. Response to ICS was defined as a reduction in daily symptom score of >0.26. Positive BDR was defined as fall in Rint of ≥0.26 kPa.s/L, ≥35% predicted or ≥1.25 Z Scores. RESULTS: Out of 138 recruited children, 67 completed the full study. Mean (SD) prebronchodilator Rint at V2 was 1.22 (0.35) kPa.s/L, and fell after starting ICS (V3) to 1.09 (0.33) kPa.s/L (p<0.001), while mean (SD) daily symptom score fell from 0.56 (0.36) to 0.28 (0.36) after ICS (p<0.001). Positive Rint BDR before ICS (at V1 and/or V2), using all three threshold criteria, was significantly associated with response to ICS on symptom scores at V3 (p<0.05). mAPI was not significantly associated with response to ICS, and parents' perception of response to bronchodilator was not related to measured Rint BDR . CONCLUSIONS: Rint BDR may be helpful in selecting which wheezy preschool children are likely to benefit from ICS.

Lung clearance index in children with cystic fibrosis previously diagnosed with CRMS/CFSPID: A monocentric prospective experience.

INTRODUCTION: No data are available on the values and role of lung clearance index (LCI) in cystic fibrosis (CF) Screen Positive Inconclusive Diagnosis (CFSPID) progressed to CF diagnosis (CFSPID > CF). This study aimed to assess the value of the LCI in correctly predicting the progression of CFSPID to CF. METHODS: This is a prospective study carried out at the CF Regional Center of Florence, Italy from September 1, 2019. We compared LCI values in children with CF diagnosed for positive newborn screening (NBS), CFSPID or CFSPID > CF for pathological sweat chloride (SC). The Exhalyzer-D (EcoMedics AG, Duernten, Switzerland, software version 3.3.1) was used to conduct the LCI tests, every 6 months on stable children. RESULTS: Forty-two cooperating children were enrolled (mean age at LCI tests: 5.4 years, range: 2.7-8.7): 26 (62%) had CF, 8 (19%) were CFSPID > CF for positive SC, while 8 (19%) kept the CFSPID label at last LCI test. The mean LCI value for patients with CF (7.39; 5.98-10.24) was statistically higher compared to both the mean LCI in the CFSPID > CF (6.62; 5.69-7.58) and in CFSPID (6.56; 5.64-7.21). CONCLUSIONS: Most of asymptomatic CFSPID or progressed to CF have normal LCI. Further data on the longitudinal course of LCI during follow up of CFSPID and on larger cohorts is needed.

Severe pediatric asthma therapy: Omalizumab-A systematic review and meta-analysis of efficacy and safety profile.

Background: Omalizumab is the first biological therapy used to treat moderate-to-severe asthma and certainly the one with the highest number of publications. Methods: A systematic review and meta-analysis were performed to examine two critical outcomes of omalizumab therapy, asthma exacerbation rate, the reduction of the use of inhaled corticosteroids (ICS), and the improvement of the lung function as a secondary outcome using the following keywords in the MEDLINE database: "anti-IgE, severe asthma, children, and randomized controlled trial." We specifically selected papers that included moderate-to-severe asthma patients and collected data on children and adolescents. Results: Four RCT studies (total number of patients = 1,239) were included in the analysis. The reported data on exacerbations showed an overall improvement in the exacerbation rate with a decreased use of inhaled steroids and some other minimal clinically important difference (MCID). Conclusions: Our systematic review confirms the known findings that omalizumab therapy decreases asthma exacerbation rate and reduces background therapy inhaled steroid dose. Therefore, add-on therapy with omalizumab shows a good efficacy and safety profile, thus proving to be a useful additional therapeutic option. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier: CRD42023396785.

Constrained DFT for Molecular Junctions.

We have explored the use of constrained density functional theory (cDFT) for molecular junctions based on benzenediamine. By elongating the junction, we observe that the energy gap between the ionization potential and the electronic affinity increases with the stretching distance. This is consistent with the trend expected from the electrostatic screening. A more detailed analysis shows how this influences the charge distribution of both the individual metal layers and the molecular atoms. Overall, our work shows that constrained DFT is a powerful tool for studying screening effects in molecular junctions.

Lung function at school age in infants with lower respiratory tract infections with and without wheezing: A birth cohort study.

OBJECTIVE: To evaluate the relationship between lower respiratory tract infections (LRTI), in the first 2 years of life and lung function at school age in the Piccolipiù birth cohort (Italy). METHODS: Data on LRTI (doctor diagnosis of bronchitis, bronchiolitis, pneumonia) and wheezing (≥3 episodes or a diagnosis of asthmatic bronchitis) in the first 2 years of life were obtained from parental questionnaires. Lung function was assessed at 7 years by spirometry and forced volume vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC, forced expiratory flow between 25% and 75%, and at 75% of FVC (FEF25-75 and FEF75 ) were reported as Z-scores. The associations between LRTI and spirometric variables were estimated with linear regression models. RESULTS: Among 877 children studied, 22.1% had LRTI only, 5.4% wheezing only, 13.2% had both, and 59.3% had neither LRTI nor wheezing. Children with LRTI had lower FVC and FEV1 than children without (Z-score differences: -0.18 [95% confidence intervals: -0.31; -0.06] and -0.15 [-0.27; -0.03]). When children were stratified by history of both LRTI and wheezing, there was no association between LRTI only and spirometric values. Conversely, having had both LRTI and wheezing was inversely associated with all lung function measures: Z-score differences of -0.24 (-0.42; -0.07); -0.42 (-0.59; -0.24); -0.25 (-0.41; -0.08); -0.37 (-0.54; -0.21); -0.30 (-0.46; -0.14) for FVC, FEV1, FEV1 /FVC, FEF25-75 and FEF75, respectively. CONCLUSION: Infants with wheezing and LRTI, but not those with LRTI only, had reduced lung function at school-age.

International consensus on lung function testing during the COVID-19 pandemic and beyond.

Coronavirus disease 2019 (COVID-19) has negatively affected the delivery of respiratory diagnostic services across the world due to the potential risk of disease transmission during lung function testing. Community prevalence, reoccurrence of COVID-19 surges and the emergence of different variants of SARS-CoV-2 have impeded attempts to restore services. Finding consensus on how to deliver safe lung function services for both patients attending and for staff performing the tests are of paramount importance. This international statement presents the consensus opinion of 23 experts in the field of lung function and respiratory physiology balanced with evidence from the reviewed literature. It describes a robust roadmap for restoration and continuity of lung function testing services during the COVID-19 pandemic and beyond. Important strategies presented in this consensus statement relate to the patient journey when attending for lung function tests. We discuss appointment preparation, operational and environmental issues, testing room requirements including mitigation strategies for transmission risk, requirement for improved ventilation, maintaining physical distance and use of personal protection equipment. We also provide consensus opinion on precautions relating to specific tests, filters, management of special patient groups and alternative options to testing in hospitals. The pandemic has highlighted how vulnerable lung function services are and forces us to re-think how long-term mitigation strategies can protect our services during this and any possible future pandemic. This statement aspires to address the safety concerns that exist and provide strategies to make lung function tests and the testing environment safer when tests are required.

Clinical significance and applications of oscillometry.

Recently, "Technical standards for respiratory oscillometry" was published, which reviewed the physiological basis of oscillometric measures and detailed the technical factors related to equipment and test performance, quality assurance and reporting of results. Here we present a review of the clinical significance and applications of oscillometry. We briefly review the physiological principles of oscillometry and the basics of oscillometry interpretation, and then describe what is currently known about oscillometry in its role as a sensitive measure of airway resistance, bronchodilator responsiveness and bronchial challenge testing, and response to medical therapy, particularly in asthma and COPD. The technique may have unique advantages in situations where spirometry and other lung function tests are not suitable, such as in infants, neuromuscular disease, sleep apnoea and critical care. Other potential applications include detection of bronchiolitis obliterans, vocal cord dysfunction and the effects of environmental exposures. However, despite great promise as a useful clinical tool, we identify a number of areas in which more evidence of clinical utility is needed before oscillometry becomes routinely used for diagnosing or monitoring respiratory disease.

Artificial intelligence for quality control of oscillometry measures.

BACKGROUND: The forced oscillation technique (FOT) allows non-invasive lung function testing during quiet breathing even without expert guidance. However, it still relies on an operator for excluding breaths with artefacts such as swallowing, glottis closure and coughing. This manual selection is operator-dependent and time-consuming. We evaluated supervised machine learning methods to exclude breaths with artefacts from data analysis automatically. METHODS: We collected 932 FOT measurements (Resmon Pro Full, Restech) from 155 patients (6-87 years) following the European Respiratory Society (ERS) technical standards. Patients were randomly assigned to either a training (70%) or test set. For each breath, we computed 71 features (including anthropometric, pressure stimulus, breathing pattern, and oscillometry data). Univariate filter, multivariate filter and wrapper methods for feature selection combined with several classification models were considered. RESULTS: Trained operators identified 4333 breaths with- and 10244 without artefacts. Features selection performed by a wrapper method combined with an AdaBoost tree model provided the best performance metrics on the test set: Balanced Accuracy = 85%; Sensitivity = 79%; Specificity = 91%; AUC-ROC = 0.93. Differences in FOT parameters computed after manual or automatic breath selection was less than ∼0.25 cmH2O*s/L for 95% of cases. CONCLUSION: Supervised machine-learning techniques allow reliable artefact detection in FOT diagnostic tests. Automating this process is fundamental for enabling FOT for home monitoring, telemedicine, and point-of-care diagnostic applications and opens new scenarios for respiratory and community medicine.

COVID-19 Pandemic and Reduced Physical Activity: Is There an Impact on Healthy and Asthmatic Children?

Physical activity (PA) has been seen to improve asthma symptoms, lung function, and quality of life, as well as to reduce airway inflammation and bronchial responsiveness. As a consequence of the COVID-19 pandemic, the minimal amount of PA recommended by the World Health Organization-i.e., about 60 min/day of moderate-to-high intensity-is difficult to achieve for many children, particularly those living in urban areas. Short-term changes in PA because of the COVID-19 pandemic may become habitual, increasing the risk of adverse asthma outcomes in children. Indeed, prolonged home confinement during the COVID-19 pandemic reduces PA levels and increases sedentary behaviors, possibly impairing immune system function and increasing susceptibility to inflammatory diseases. However, there is limited evidence regarding the effects of lockdown due to COVID-19 on PA and sedentary behaviors in asthmatic children. Given that children stay longer indoors, indoor air pollution represents a major issue to consider during home confinement. This narrative review aims to summarize the available evidence about the impact of decreased PA and increased sedentary behaviors on children with asthma during the COVID-19 pandemic. In addition, strategies for supporting PA in children with asthma during the COVID-19 pandemic are suggested, also looking at the issue of indoor air quality.