Engineering vibrationally-assisted energy transfer in a trapped-ion quantum simulator

Many important chemical and biochemical processes in the condensed phase are notoriously difficult to simulate numerically. Often this difficulty arises from the complexity of simulating dynamics resulting from coupling to structured, mesoscopic baths, for which no separation of time scales exists and statistical treatments fail. A prime example of such a process is vibrationally assisted charge or energy transfer. A quantum simulator, capable of implementing a realistic model of the system of interest, could provide insight into these processes in regimes where numerical treatments fail. We take a first step towards modeling such transfer processes using an ion trap quantum simulator. By implementing a minimal model, we observe vibrationally assisted energy transport between the electronic states of a donor and an acceptor ion augmented by coupling the donor ion to its vibration. We tune our simulator into several parameter regimes and, in particular, investigate the transfer dynamics in the nonperturbative regime often found in biochemical situations

Mechanistic features of isomerizing alkoxycarbonylation of methyl oleate.

The weakly coordinated triflate complex [(P∧P)Pd(OTf)]+(OTf)− (1) (P∧ P = 1,3-bis(di-tert-butylphosphino) propane) is a suitable reactive precursor for mechanistic studies of the isomerizing alkoxcarbonylation of methyl oleate. Addition of CH3OH or CD3OD to 1 forms the hydride species [(P∧P)PdH(CH3OH)]+(OTf)− (2-CH3OH) or the deuteride [(P∧P)PdD(CD3OD)]+(OTf)− (2DCD3OD), respectively. Further reaction with pyridine cleanly affords the stable and isolable hydride [(P∧P)PdH- (pyridine)]+(OTf)− (2-pyr). This complex yields the hydride fragment free of methanol by abstraction of pyridine with BF3·OEt2, and thus provides an entry to mechanistic observations including intermediates reactive toward methanol. Exposure of methyl oleate (100 equiv) to 2D-CD3OD resulted in rapid isomerization to the thermodynamic isomer distribution, 94.3% of internal olefins, 5.5% of α,β-unsaturated ester and <0.2% of terminal olefin. Reaction of 2-pyr/BF3·OEt2 with a stoichiometric amount of 1-13C-labeled 1-octene at −80 °C yields a 50:50 mixture of the linear alkyls [(P∧P)Pd13CH2(CH2)6CH3]+ and [(P∧P)PdCH2(CH2)6 13CH3]+ (4a and 4b). Further reaction with 13CO yields the linear acyls [(P∧P)Pd13C(=O)12/13CH2(CH2)6 12/13CH3(L)]+ (5-L; L = solvent or 13CO). Reaction of 2-pyr/ BF3·OEt2 with a stoichiometric amount of methyl oleate at −80 °C also resulted in fast isomerization to form a linear alkyl species [(P∧P)PdCH2(CH2)16C(=O)OCH3]+ (6) and a branched alkyl stabilized by coordination of the ester carbonyl group as a four membered chelate [(P∧P)PdCH{(CH2)15CH3}C(=O)OCH3]+ (7). Addition of carbon monoxide (2.5 equiv) at −80 °C resulted in insertion to form the linear acyl carbonyl [(P∧P)PdC(=O)(CH2)17C(=O)OCH3(CO)]+ (8-CO) and the fivemembered chelate [(P∧P)PdC(=O)CH{(CH2)15CH3}C(=O)OCH3]+ (9). Exposure of 8-CO and 9 to 13CO at −50 °C results in gradual incorporation of the 13C label. Reversibility of 7 + CO ⇄ 9 is also evidenced by ΔG = −2.9 kcal mol−1 and ΔG‡ = 12.5 kcal mol−1 from DFT studies. Addition of methanol at −80 °C results in methanolysis of 8-L (L = solvent) to form the linear diester, 1,19-dimethylnonadecandioate, whereas 9 does not react and no branched diester is observed. DFT yields a barrier for methanolysis of ΔG‡ = 29.7 kcal mol−1 for the linear (8) vs ΔG‡ = 37.7 kcal mol−1 for the branched species (9)

Age and body mass index affect fit of spirometry Global Lung Function Initiative references in schoolchildren

BACKGROUND: References from the Global Lung Function Initiative (GLI) are widely used to interpret children's spirometry results. We assessed fit for healthy schoolchildren. METHODS: LuftiBus in the School was a population-based cross-sectional study undertaken in 2013-2016 in the canton of Zurich, Switzerland. Parents and their children aged 6-17 years answered questionnaires about respiratory symptoms and lifestyle. Children underwent spirometry in a mobile lung function lab. We calculated GLI-based z-scores for forced expiratory volume in 1 s (FEV$_{1}$), forced vital capacity (FVC), FEV$_{1}$/FVC and forced expiratory flow for 25-75% of FVC (FEF$_{25-75}$) for healthy White participants. We defined appropriate fit to GLI references by mean values between +0.5 and -0.5 z-scores. We assessed whether fit varied by age, body mass index, height and sex using linear regression models. RESULTS: We analysed data from 2036 children with valid FEV$_{1}$ measurements, of whom 1762 also had valid FVC measurements. The median age was 12.2 years. Fit was appropriate for children aged 6-11 years for all indices. In adolescents aged 12-17 years, fit was appropriate for FEV$_{1}$/FVC z-scores (mean±sd -0.09±1.02), but not for FEV$_{1}$ (-0.62±0.98), FVC (-0.60±0.98) and FEF$_{25-75}$ (-0.54±1.02). Mean FEV$_{1}$, FVC and FEF$_{25-75}$ z-scores fitted better in children considered overweight (-0.25, -0.13 and -0.38, respectively) than normal weight (-0.55, -0.50 and -0.55, respectively; p-trend <0.001, 0.014 and <0.001, respectively). FEV$_{1}$, FVC and FEF$_{25-75}$ z-scores depended on both age and height (p-interaction 0.033, 0.019 and <0.001, respectively). CONCLUSION: GLI-based FEV$_{1}$, FVC, and FEF$_{25-75}$ z-scores do not fit White Swiss adolescents well. This should be considered when using reference equations for clinical decision-making, research and international comparison

Age and body mass index affect fit of spirometry Global Lung Function Initiative references in schoolchildren.

Background References from the Global Lung Function Initiative (GLI) are widely used to interpret children's spirometry results. We assessed fit for healthy schoolchildren. Methods LuftiBus in the School was a population-based cross-sectional study undertaken in 2013-2016 in the canton of Zurich, Switzerland. Parents and their children aged 6-17 years answered questionnaires about respiratory symptoms and lifestyle. Children underwent spirometry in a mobile lung function lab. We calculated GLI-based z-scores for forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC and forced expiratory flow for 25-75% of FVC (FEF25-75) for healthy White participants. We defined appropriate fit to GLI references by mean values between +0.5 and -0.5 z-scores. We assessed whether fit varied by age, body mass index, height and sex using linear regression models. Results We analysed data from 2036 children with valid FEV1 measurements, of whom 1762 also had valid FVC measurements. The median age was 12.2 years. Fit was appropriate for children aged 6-11 years for all indices. In adolescents aged 12-17 years, fit was appropriate for FEV1/FVC z-scores (mean±sd -0.09±1.02), but not for FEV1 (-0.62±0.98), FVC (-0.60±0.98) and FEF25-75 (-0.54±1.02). Mean FEV1, FVC and FEF25-75 z-scores fitted better in children considered overweight (-0.25, -0.13 and -0.38, respectively) than normal weight (-0.55, -0.50 and -0.55, respectively; p-trend <0.001, 0.014 and <0.001, respectively). FEV1, FVC and FEF25-75 z-scores depended on both age and height (p-interaction 0.033, 0.019 and <0.001, respectively). Conclusion GLI-based FEV1, FVC, and FEF25-75 z-scores do not fit White Swiss adolescents well. This should be considered when using reference equations for clinical decision-making, research and international comparison

Phenotypic characteristics, healthcare use, and treatment in children with night cough compared with children with wheeze

Objectives: Population‐based studies of children with dry night cough alone compared with those who also wheeze are few and inconclusive. We compared how children with dry night cough differ from those who wheeze. Methods: LuftiBus in the school is a population‐based study of schoolchildren conducted between 2013 and 2016 in Zurich, Switzerland. We divided children into four mutually exclusive groups based on reported dry night cough (henceforth referred as “cough”) and wheeze and compared parent‐reported symptoms, comorbidities, exposures, FeNO, spirometry, and healthcare use and treatment. Results: Among 3457 schoolchildren aged 6–17 years, 294 (9%) reported “cough,” 181 (5%) reported “wheeze,” 100 (3%) reported “wheeze and cough,” and 2882 (83%) were “asymptomatic.” Adjusting for confounders in a multinomial regression, children with “cough” reported more frequent colds, rhinitis, and snoring than “asymptomatic” children; children with “wheeze” or “wheeze and cough” more often reported hay fever, eczema, and parental histories of asthma. FeNO and spirometry were similar among “asymptomatic” and children with “cough,” while children with “wheeze” or “wheeze and cough” had higher FeNO and evidence of bronchial obstruction. Children with “cough” used healthcare less often than those with “wheeze,” and they attended mainly primary care. Twenty‐two children (7% of those with “cough”) reported a physician diagnosis of asthma and used inhalers. These had similar characteristics as children with wheeze. Conclusion: Our representative population‐based study confirms that children with dry night cough without wheeze clearly differed from those with wheeze. This suggests asthma is unlikely, and they should be investigated for alternative aetiologies, particularly upper airway disease

Phenotypic characteristics, healthcare use, and treatment in children with night cough compared with children with wheeze.

OBJECTIVES Population-based studies of children with dry night cough alone compared with those who also wheeze are few and inconclusive. We compared how children with dry night cough differ from those who wheeze. METHODS LuftiBus in the school is a population-based study of schoolchildren conducted between 2013 and 2016 in Zurich, Switzerland. We divided children into four mutually exclusive groups based on reported dry night cough (henceforth referred as "cough") and wheeze and compared parent-reported symptoms, comorbidities, exposures, FeNO, spirometry, and healthcare use and treatment. RESULTS Among 3457 schoolchildren aged 6-17 years, 294 (9%) reported "cough," 181 (5%) reported "wheeze," 100 (3%) reported "wheeze and cough," and 2882 (83%) were "asymptomatic." Adjusting for confounders in a multinomial regression, children with "cough" reported more frequent colds, rhinitis, and snoring than "asymptomatic" children; children with "wheeze" or "wheeze and cough" more often reported hay fever, eczema, and parental histories of asthma. FeNO and spirometry were similar among "asymptomatic" and children with "cough," while children with "wheeze" or "wheeze and cough" had higher FeNO and evidence of bronchial obstruction. Children with "cough" used healthcare less often than those with "wheeze," and they attended mainly primary care. Twenty-two children (7% of those with "cough") reported a physician diagnosis of asthma and used inhalers. These had similar characteristics as children with wheeze. CONCLUSION Our representative population-based study confirms that children with dry night cough without wheeze clearly differed from those with wheeze. This suggests asthma is unlikely, and they should be investigated for alternative aetiologies, particularly upper airway disease

Agreement of parent- and child-reported wheeze and its association with measurable asthma traits

Objectives In epidemiological studies, childhood asthma is usually assessed with questionnaires directed at parents or children, and these may give different answers. We studied how well parents and children agreed when asked to report symptoms of wheeze and investigated whose answers were closer to measurable traits of asthma. Methods LuftiBus in the school is a cross-sectional survey of respiratory health among Swiss schoolchildren aged 6–17 years. We applied questionnaires to parents and children asking about wheeze and exertional wheeze in the past year. We assessed agreement between parent–child answers with Cohen's kappa (k), and associations of answers from children and parents with fractional exhaled nitric oxide (FeNO) and forced expiratory volume in 1 s over forced vital capacity (FEV1/FVC), using quantile regression. Results We received questionnaires from 3079 children and their parents. Agreement was poor for reported wheeze (k = 0.37) and exertional wheeze (k = 0.36). Median FeNO varied when wheeze was reported by children (19 ppb, interquartile range [IQR]: 9–44), parents (22 ppb, IQR: 12–46), both (31 ppb, IQR: 16–55), or neither (11 ppb, IQR: 7–19). Median absolute FEV1/FVC was the same when wheeze was reported by children (84%, IQR: 78–89) and by parents (84%, IQR: 78–89), lower when reported by both (82%, IQR: 78–87), and higher when reported by neither (87%, IQR: 82–91). For exertional wheeze findings were similar. Results did not differ by age or sex. Conclusion Our findings suggest that surveying both parents and children and combining their responses can help us to better identify children with measurable asthma traits

Air pollution exposure during pregnancy and lung function in childhood: The LUIS study

BACKGROUND: The adverse effects of high air pollution levels on childhood lung function are well‐known. Limited evidence exists on the effects of moderate exposure levels during early life on childhood lung function. We investigated the association of exposure to moderate air pollution during pregnancy, infancy, and preschool time with lung function at school age in a Swiss population‐based study. METHODS: Fine‐scale spatiotemporal model estimates of particulate matter with a diameter <2.5 µm (PM$_{2.5}$) and nitrogen dioxide (NO$_{2}$) were linked with residential address histories. We compared air pollution exposures within different time windows (whole pregnancy, first, second, and third trimester of pregnancy, first year of life, preschool age) with forced expiratory volume in 1 s (FEV$_{1}$) and forced vital capacity (FVC) measured cross‐sectionally using linear regression models adjusted for potential confounders. RESULTS: We included 2182 children, ages 6−17 years. Prenatal air pollution exposure was associated with reduced lung function at school age. In children aged 12 years, per 10 µg·m$^{−3}$ increase in PM$_{2.5}$ during pregnancy, FEV$_{1}$ was 55 mL lower (95% CI −84 to −25 mL) and FVC 62 mL lower (95% CI −96 to −28 mL). Associations were age‐dependent since they were stronger in younger and weaker in older children. PM$_{2.5}$ exposure after birth was not associated with reduced lung function. There was no association between NO$_{2}$ exposure and lung function. CONCLUSION: In utero lung development is most sensitive to air pollution exposure, since even modest PM$_{2.5}$ exposure during the prenatal time was associated with reduced lung function, most prominent in younger children

Evaluation of the double-tracer gas single-breath washout test in a pediatric field study.

BACKGROUND The early-life origins of chronic pulmonary diseases are thought to arise in peripheral small airways. Predictors of ventilation inhomogeneity, a proxy of peripheral airway function, are understudied in schoolchildren. RESEARCH QUESTION Is the double-tracer gas single-breath washout (DTG-SBW) measurement feasible in a pediatric field study setting? What are the predictors of the DTG-SBW derived ventilation inhomogeneity estimate in unselected schoolchildren? STUDY DESIGN AND METHODS In this prospective cross-sectional field study, a mobile lung function-testing unit visited participating schools in Switzerland. We applied DTG-SBW, fraction of exhaled nitric oxide (FeNO), and spirometry measurements. The DTG-SBW is based on tidal inhalation of helium (He) and sulfur-hexafluoride (SF6) and the phase III slope (SIIIHe-SF6) is derived. We assessed feasibility, repeatability, and associations of SIIIHe-SF6 with the potential predictors anthropometrics, presence of wheeze (i.e. parental report of ≥ 1 episode of wheeze in the prior year), FeNO, forced expiratory volume in the first second (FEV1), and FEV1/forced vital capacity (FVC). RESULTS In 1782 children, 5223 DTG-SBW trials were obtained. The DTG-SBW was acceptable in 1449 (81.3%) children, coefficient of variation was 39.8%. SIIIHe-SF6 was independently but weakly positively associated with age and BMI. In 276 (21.2%) children, wheeze was reported. SIIIHe-SF6 was higher by 0.049 g.mol.L-1 in children with wheeze as compared to those without and remained associated with wheeze after adjusting for age and BMI in a multi-variable linear regression model. SIIIHe-SF6 was not associated with FeNO, FEV1, and FEV1/FVC. INTERPRETATION The DTG-SBW is feasible in a pediatric field study setting. On the population level, age, body composition and wheeze are independent predictors of peripheral airway function in unselected schoolchildren. The variation of the DTG-SBW possibly constrains its current applicability on the individual level