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匹配条件： “Courtney M. Wheatley” ，找到相关结果约481814条。
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Variability in Measures of Exhaled Breath Na+, Influence of Pulmonary Blood Flow and Salivary Na+
Courtney M. Wheatley, Nicholas A. Cassuto, William T. Foxx-Lupo and Eric M. Snyder
Clinical Medicine Insights: Circulatory, Respiratory and Pulmonary Medicine , 2012, DOI: 10.4137/CCRPM.S4718

Abstract: The assessment of inflammatory markers and ions in exhaled breath condensate (EBC) is being utilized more frequently in diseases such as asthma and cystic fibrosis with marked variability in EBC measures, including those of exhaled Na+. We sought to determine if variability in exhaled Na+ was due to differences in pulmonary blood flow (PBF) or Na+ in the mouth (salivary Na+). We measured exhaled Na+ three times with coinciding sampling of salivary Na+ and assessment of PBF (using acetylene rebreathing) in 13 healthy subjects (54% female, age = 27 ± 7 yrs., ht. = 172 ± 10 cm, wt. = 70 ± 21 kg, BMI = 22 ± 7 kg/m2 mean ± SD). Exhaled Na+ averaged 2.7 ± 1.2 mmol/l, and salivary Na+ averaged 5.51 ± 4.58 mmol/l. The coefficients of variation across all three measures in all 13 subjects averaged 30% for exhaled Na+ and 83% for salivary Na+, within subjects the variability across the three measures averaged 30% for exhaled Na+ and 38% for salivary Na+. Across all three measures in all 13 subjects the relationship between PBF and exhaled Na+ averaged 0.027 (P = 0.87), and the relationship between salivary Na+ and exhaled Na+ concentrations averaged 0.59 (P = 0.001). Also, we sought to determine the relationship between exhaled Na+ and serum Na+ in an addition 20 subjects. There was a moderate and significant relationship between serum Na+ and exhaled Na+ (r = 0.37, P = 0.04). These findings suggest there that the variability in exhaled Na+ is caused, at least in part, by droplet formation from within the mouth as turbulent air passes through and that there is a flux of ions from the pulmonary blood into the airways.

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Influence of the Vibralung Acoustical Percussor on pulmonary function and sputum expectoration in individuals with cystic fibrosis
Cori M. Daines,Courtney M. Wheatley,Eric M. Snyder,Hanna Phan,Marina G. Martinez,Sarah E. Baker,Wayne J. Morgan
- , 2018, DOI: 10.1177/1753466618770997

Abstract: The Vibralung Acoustical Percussor is a new airway clearance therapy (ACT) utilizing intrapulmonary sound waves in addition to positive expiratory pressure (PEP). We evaluated the safety of the Vibralung and collected preliminary data on its ability to mediate sputum expectoration in individuals with cystic fibrosis (CF)

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The influence of thoracic gas compression and airflow density dependence on the assessment of pulmonary function at high altitude
Alex Carlson,Bruce D. Johnson,Courtney Wheatley,Glenn M. Stewart,Jan Stepanek,Kirsten Coffman,Norman R. Morris,Troy J. Cross
- , 2018, DOI: 10.14814/phy2.13576

Abstract: The purpose of this report was to illustrate how thoracic gas compression (TGC) artifact, and differences in air density, may together conflate the interpretation of changes in the forced expiratory flows (FEFs) at high altitude (>2400 m). Twenty‐four adults (10 women; 44 ± 15 year) with normal baseline pulmonary function (>90% predicted) completed a 12‐day sojourn at Mt. Kilimanjaro. Participants were assessed at Moshi (Day 0, 853 m) and at Barafu Camp (Day 9, 4837 m). Typical maximal expiratory flow‐volume (MEFV) curves were obtained in accordance with ATS/ERS guidelines, and were either: (1) left unadjusted; (2) adjusted for TGC by constructing a “maximal perimeter” MEFV curve; or (3) adjusted for both TGC and differences in air density between altitudes. Forced vital capacity (FVC) was lower at Barafu compared with Moshi camp (5.19 ± 1.29 L vs. 5.40 ± 1.45 L, P < 0.05). Unadjusted data indicated no difference in the mid‐expiratory flows (FEF 25–75%) between altitudes (？ + 0.03 ± 0.53 L sec？1; ？ + 1.2 ± 11.9%). Conversely, TGC‐adjusted data revealed that FEF 25–75% was significantly improved by sojourning at high altitude (？ + 0.58 ± 0.78 L sec？1; ？ + 12.9 ± 16.5%, P < 0.05). Finally, when data were adjusted for TGC and air density, FEFs were “less than expected” due to the lower air density at Barafu compared with Moshi camp (？–0.54 ± 0.68 L sec？1; ？–10.9 ± 13.0%, P < 0.05), indicating a mild obstructive defect had developed on ascent to high altitude. These findings clearly demonstrate the influence that TGC artifact, and differences in air density, bear on flow‐volume data; consequently, it is imperative that future investigators adjust for, or at least acknowledge, these confounding factors when comparing FEFs between altitudes

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Impact of chronic systolic heart failure on lung structure–function relationships in large airways
Bruce D. Johnson,Bryan J. Taylor,Courtney M. Wheatley,Eric M. Snyder,Kenneth C. Beck,Lyle J. Olson,Robert J. Wentz,Steven C. Chase
- , 2016, DOI: 10.14814/phy2.12867

Abstract: Heart failure (HF) is often associated with pulmonary congestion, reduced lung function, abnormal gas exchange, and dyspnea. We tested whether pulmonary congestion is associated with expanded vascular beds or an actual increase in extravascular lung water (EVLW) and how airway caliber is affected in stable HF. Subsequently we assessed the influence of an inhaled short acting beta agonist (SABA). Thirty‐one HF (7F; age, 62 ± 11 years; ht. 175 ± 9 cm; wt. 91 ± 17 kg; LVEF, 28 ± 15%) and 29 controls (11F; age; 56 ± 11 years; ht. 174 ± 8 cm; wt. 77 ± 14 kg) completed the study. Subjects performed PFTs and a chest computed tomography (CT) scan before and after SABA. CT measures of attenuation, skew, and kurtosis were obtained from areas of lung tissue to assess EVLW. Airway luminal areas and wall thicknesses were also measured. CT tissue density suggested increased EVLW in HF without differences in the ratio of airway wall thickness to luminal area or luminal area to TLC (skew: 2.85 ± 1.08 vs. 2.11 ± 0.79, P < 0.01; Kurtosis: 15.5 ± 9.5 vs. 9.3 ± 5.5 P < 0.01; control vs. HF). PFTs were decreased in HF at baseline (% predicted FVC:101 ± 15% vs. 83 ± 18%, P < 0.01;FEV1:103 ± 15% vs. 82 ± 19%, P < 0.01;FEF25–75: 118 ± 36% vs. 86 ± 36%, P < 0.01; control vs. HF). Airway luminal areas, but not CT measures, were correlated with PFTs at baseline. The SABA cleared EVLW and decreased airway wall thickness but did not change luminal area. Patients with HF had evidence of increased EVLW, but not an expanded bronchial circulation. Airway caliber was maintained relative to controls, despite reductions in lung volume and flow rates. SABA improved lung function, primarily by reducing EVLW

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Superfluid anisotropy in YBCO: Evidence for pair tunneling superconductivity
T. Xiang,J. M. Wheatley
Physics , 1995, DOI: 10.1103/PhysRevLett.76.134

Abstract: Proximity effect and pair tunneling models are applied as alternative scenarios to explain the recently measured $ab$-plane and $c$-axis components of the superfluid tensor in Copper-Oxide superconductors which contain chains, such as $YBa_2Cu_3O_{6.95}$. It is argued that conventional proximity effect models, which couple chains and planes via single electron tunneling only, are incompatible with the experimental observations. On the other hand several surprising features of the experimental data are readily explained by the presence of a microscopic pair tunneling process.

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Non-magnetic impurities in two dimensional superconductors
T. Xiang,J. M. Wheatley
Physics , 1995, DOI: 10.1103/PhysRevB.51.11721

Abstract: A numerical approach to disordered 2D superconductors described by BCS mean field theory is outlined. The energy gap and the superfluid density at zero temperature and the quasiparticle density of states are studied. The method involves approximate self-consistent solutions of the Bogolubov-de$\,$Gennes equations on finite square lattices. Where comparison is possible, the results of standard analytic approaches to this problem are reproduced. Detailed modeling of impurity effects is practical using this approach. The {\it range} of the impurity potential is shown to be of {\it quantitative importance} in the case of strong potential scatterers. We discuss the implications for experiments, such as the rapid suppression of superconductivity by Zn doping in Copper-Oxide superconductors.

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Disorder effect in low dimensional superconductors
T Xiang,J M Wheatley
Physics , 1994, DOI: 10.1016/0921-4534(94)92425-2

Abstract: The quasiparticle density of states (DOS), the energy gap, the superfluid density $\rho_s$, and the localization effect in the s- and d-wave superconductors with non-magnetic impurity in two dimensions (2D) are studied numerically. For strong (unitary) scatters, we find that it is the range of the scattering potential rather than the symmetry of the superconducting pairing which is more important in explaining the impurity dependences of the specific heat and the superconducting transition temperature in Zn doped YBCO. The localization length is longer in the d-wave superconducting state than in the normal state, even in the vicinity of the Fermi energy.

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Quasiparticle energy dispersion in doped two dimensional quantum antiferromagnets
T. Xiang,J. M. Wheatley
Physics , 1996, DOI: 10.1103/PhysRevB.54.R12653

Abstract: The quasiparticle dispersion in the one-hole t-t'-t"-J model is studied. Both the finite-size diagonalization and the self-consistent Born approximation calculations have been performed and compared. The quasiparticle band structures in the hole and electron doped high-Tc cuprates are qualitatively different. In the hole doped compounds, the band maxima locate at (pi/2 , pi/2), while in the electron doped compounds the band maxima locate at (pi, 0) and its equivalent points. The angle-resolved photoemission data for the quasiparticle dispersion of Sr_2CuO_2Cl_2 can be quantitatively reproduced using the one band t-t'-t"-J model with the three-site hopping term.

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c axis superfluid response of Copper-Oxide superconductors
T. Xiang,J. M. Wheatley
Physics , 1996, DOI: 10.1103/PhysRevLett.77.4632

Abstract: A novel interplay between d-wave superconducting order parameter symmetry and the underlying Cu 3d orbital based electronic structure of Copper-Oxides leads to a striking anisotropy in the superfluid response of these systems. In clean tetragonal materials the c-axis penetration depth increases as T^5 at low temperature T, in contrast to linear T behavior in the ab-plane. Disorder is a relevant perturbation which causes all components of the superfluid response to depend quadratically on temperature at low temperature. However, the cross-over temperature scale from the intrinsic d-wave behavior to the disorder dominated behavior for the in-plane response may be different from that for the out-plane response.

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Impact of the Glucosinolate Sinigrin on Bacterial Communities in Pieris rapae [PDF]
Leslie M. McKinnon, Courtney J. Robinson
Advances in Microbiology (AiM) , 2016, DOI: 10.4236/aim.2016.68057

Abstract: Dynamics in animal-associated microbiota can be difficult to study due to community complexity. Previous work showed that microbial communities in the midguts of Pieris rapae larvae contain relatively few members. In this study, we used P. rapae to test hypotheses related to how diet impacts gastrointestinal microbiota. More specifically, we investigated how the concentration of sinigrin, a glucosinolate in the natural diet of this insect, alters microbial community structure. Larvae were fed either sterile wheat germ diet alone or amended with 3.0 mg/ml, 6.0 mg/ml, or 9.0 mg/ml of sinigrin. In order to determine shifts in the gut microbial community, 16S rRNA genes from midguts were subjected to pyrosequencing and analyzed. Sinigrin had a significant impact on microbial communities in fourth instar P. rapae larvae, but this was dependent on concentration. The predominant phyla in all treatment groups were Proteobacteria and Firmicutes. Significant difference in beta diversity was typically observed when sinigrin 6 mg/ml and the control treatment groups were compared. The impact of sinigrin on the structure of the midgut microbiota is dependent on concentration, but not in a linear fashion. This may indicate that types and concentrations of glucosinolates have varied impact on midgut microbial community.

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