bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of positioning on the Hering‐Breuer reflex in the preterm infant
Authors: Hand Ivan L. , Noble Lawrence , Geiss Donna 
Published: November 2006

AbstractThe aim of this study was to determine the effect of positioning on the Hering‐Breuer inflation reflex (HBIR) in the preterm infant. Seven, non‐intubated, premature infants, ranging in birthweight from 732 to 1450 g with post‐conceptual ages of 32–36 weeks were studied. In each infant, pulmonary function testing, including the HBIR was obtained using the SensorMedics 2600 during quiet sleep in the supine and prone position. The strength of the HBIR was quantified by the measurement of the percent prolongation of expiration after an occluded breath. Sleep states were categorized by the criteria of Prechtl. There was a significant difference in Hering‐Breuer activity in the prone position versus the supine position with a consistently stronger reflex in the prone position. The mean percent prolongation of expiration was 237 ± 108% in the prone position versus 95 ± 32% in the supine position. Analysis of the data, using paired t‐testing revealed a mean difference of 142 ± 119% between prone and supine positions (P = 0.028). Significant differences in the strength of the HBIR occur in relation to positioning in the preterm infant. Newborn positioning may affect pulmonary reflexes and may play a role in control of breathing. Pediatr Pulmonol. 2007; 42:37–40. © 2006 Wiley‐Liss, Inc.
Prospectively assessed incidence, severity, and determinants of respiratory symptoms in the first year of life
Authors: Latzin P. , Frey U. , Roiha H.L. , Baldwin D.N. , Regamey N. , Strippoli M.‐P.F. , Zwahlen M. , Kuehni C.E. 
Published: November 2006

AbstractRespiratory symptoms are common in infancy. Nevertheless, few prospective birth cohort studies have studied the epidemiology of respiratory symptoms in normal infants. The aim of this study was to prospectively obtain reliable data on incidence, severity, and determinants of common respiratory symptoms (including cough and wheeze) in normal infants and to determine factors associated with these symptoms. In a prospective population‐based birth cohort, we assessed respiratory symptoms during the first year of life by weekly phone calls to the mothers. Poisson regression was used to examine the association between symptoms and various risk factors. In the first year of life, respiratory symptoms occurred in 181/195 infants (93%), more severe symptoms in 89 (46%). The average infant had respiratory symptoms for 4 weeks and 90% had symptoms for less than 12 weeks (range 0 to 23). Male sex, higher birth weight, maternal asthma, having older siblings and nursery care were associated with more, maternal hay fever with fewer respiratory symptoms. The association with prenatal maternal smoking decreased with time since birth. This study provides reliable data on the frequency of cough and wheeze during the first year of life in healthy infants; this may help in the interpretation of published hospital and community‐based studies. The apparently reduced risk in children of mothers with hayfever but no asthma, and the decreasing effect of prenatal smoke exposure over time illustrate the complexity of respiratory pathology in the first year of life. Pediatr Pulmonol. 2007; 42:41–50. © 2006 Wiley‐Liss, Inc.
Human metapneumovirus and respiratory syncytial virus infections in older children with cystic fibrosis
Authors: Garcia Daniel F. , Hiatt Peter W. , Jewell Alan , Schoonover Shauna L. , Cron Stanley G. , Riggs Mark , Grace Susan , Oermann Christopher M. , Piedra Pedro A. 
Published: November 2006

AbstractBackground:Human metapneumovirus (hMPV) has been isolated from children with acute respiratory infection worldwide. Its epidemiology remains to be defined in children with cystic fibrosis (CF). We describe the epidemiology and clinical impact of hMPV in CF children and compared it to respiratory syncytial virus (RSV).Methods:CF children ages 7–18 years were studied prospectively during the 1998–1999 RSV season. Nasopharyngeal specimens were collected during acute respiratory illnesses and tested for respiratory viruses. Blood specimens were drawn early, mid, and end of the RSV season, and tested for serological evidence of hMPV and RSV infections. Rates of lower respiratory tract illnesses (LRTI) and hospitalizations for pulmonary exacerbations were compared during the time intervals they developed serological evidence of infection to their non‐infection intervals.Results:Six of 44 CF children had a virus positive respiratory illness in 56 LTRI events and 18 hospitalizations. Serological evidence of hMPV and RSV infections occurred in 16 and 20 CF children, respectively; 8 had infections with both viruses. A greater proportion of CF children had ≥1 LRTI during their infection intervals compared to their non‐infection intervals (13/25 vs. 5/25; P = 0.03). A trend for higher rates of LRTI was observed in the infection intervals compared to non‐infection intervals (9.5 ± 11.0 vs. 4.2 ± 9.9 per 1,000 child‐days; P = 0.06), and it was significantly greater with a more conservative estimate (one event per child per interval; 7.4 ± 7.7 vs. 2.6 ± 5.4 per 1,000 child‐days; P ≤0.01). No differences in hospitalizations rates were detected.Conclusion:The infection rates and clinical impact observed for hMPV were comparable to that for RSV in CF children 7–18 years of age. Pediatr Pulmonol. 2007; 42:66–74. © 2006 Wiley‐Liss, Inc.
Sequential alterations of tracheal mechanical properties in the neonatal lamb: Effect of mechanical ventilation
Authors: Miller Thomas L. , Zhu Yan , Altman Allison R. , Dysart Kevin , Shaffer Thomas H. 
Published: November 2006

AbstractAlterations in neonatal airway mechanics resulting from ventilatory therapies are implicated in airway collapse and chronic disease. Quantifying the functional impact of mechanical ventilation (MV) on the neonatal airway and elucidating the time course of these changes will support development of protective therapies. The objective of this study was to test the hypothesis that conventional MV would result in decreased static and dynamic elastance of an isolated tracheal segment and thinning of the muscle (trachealis) region of the tracheal wall in a time dependent manner. Tracheal segments were isolated in newborn lambs spontaneously breathing through the distal trachea; segments were MV (n = 7; PIP/PEEP = 35/5 cmH2O; 40 breaths/min) or instrumented, non‐ventilated (SHAM; n = 7; PIP/PEEP = 0/0 cmH2O) for 4 hr. At baseline and hourly, tracheal segments were filled with saline, and static pressure–volume curves were constructed as the pressure response to stepwise volume infusions. Then, cross‐sectional ultrasound images were captured at 0 cmH2O on SHAM, and at 0 cmH2O, peak inspiratory pressure (PIP) and positive end expiratory pressure (PEEP), on MV tracheae for subsequent dimensional analysis. Tracheal elasticity indices were derived from static pressure–volume data, and during dynamic ventilation using ultrasound images to calculate the stress–strain relationships. Over 4 hr of MV, tracheal internal diameter (ID) increased (14%; P < 0.05). Markers of tracheal mechanical properties indicated a decrease in elasticity under both static (bulk modulus; 28%; P < 0.05) and dynamic (elastic modulus; 282 %; P < 0.05) conditions, indicating a significant alteration in elastic components. No time dependent changes were identified in dimensions or mechanical properties in the SHAM group. Conclusions: MV results in dimensional alterations that increased anatomical dead space and reduced static and dynamic elastance of the neonatal trachea. Pediatr Pulmonol. 2007; 42:141–149. © 2006 Wiley‐Liss, Inc.
Routine physiotherapy does not induce a cardiorespiratory training effect post‐stroke, regardless of walking ability
Authors: Kuys Suzanne , Brauer Sandra , Ada Louise 
Published: November 2006

AbstractBackground and Purpose. Cardiorespiratory fitness is increasingly being recognized as an impairment requiring physiotherapy intervention after stroke. The present study seeks to investigate if routine physiotherapy treatment is capable of inducing a cardiorespiratory training effect and if stroke patients attending physiotherapy who are unable to walk experience less cardiorespiratory stress during physiotherapy when compared to those who are able to walk. Method. A descriptive, observational study, with heart rate monitoring and video‐recording of physiotherapy rehabilitation, was conducted. Thirty consecutive stroke patients from a geriatric and rehabilitation unit of a tertiary metropolitan hospital, admitted for rehabilitation, and requiring physiotherapy were included in the study. The main measures of the study were duration (time) and intensity (percentage of heart rate reserve) of standing and walking activities during physiotherapy rehabilitation for non‐walking and walking stroke patients. Results. Stroke patients spent an average of 21 minutes participating in standing and walking activities that were capable of inducing a cardiorespiratory training effect. Stroke patients who were able to walk spent longer in these activities during physiotherapy rehabilitation than non‐walking stroke patients (p < 0.05). An average intensity of 24% heart rate reserve (HRR) during standing and walking activities was insufficient to result in a cardiorespiratory training effect, with a maximum of 35% achieved for the stroke patients able to walk and 30% for those unable to walk. Conclusions. Routine physiotherapy rehabilitation had insufficient duration and intensity to result in a cardiorespiratory training effect in our group of stroke patients. Copyright © 2006 John Wiley & Sons, Ltd.
Co‐variation of tests commonly used in stroke rehabilitation
Authors: Langhammer Birgitta , Stanghelle Johan Kvalvik 
Published: November 2006

AbstractBackground and Purpose. The aim of the present study was to analyse the co‐variation of different tests commonly used in stroke rehabilitation, and specifically used in a recent randomized, controlled study of two different physiotherapy models in stroke rehabilitation. Method. Correlations of the performed tests and recordings from previous work were studied. The test results from three‐month, one‐year and four‐year follow‐up were analysed in an SPSS Version 11 statistical package with Pearson and Spearman correlations. Results. There was an expected high correlation between the motor function tests, both based on partial and total scores. The correlations between Nottingham Health Profile Part 1 and Motor Assessment Scale (MAS), Sødring Motor Eevaluation Scale (SMES), the Berg Balance Scale (BBS) and Barthel Activities of Daily Living (ADL) index were low for all items except physical condition. The correlations between registered living conditions, assistive devices, recurrent stroke, motor function (MAS, SMES), ADL (Barthel ADL index) and balance (BBS) were high. The same variables showed weak or poor correlation to the Nottingham Health Profile (NHP). Conclusions. The co‐variations of motor function tests and functional tests were high, but the co‐variations of motor, functional and self‐reported life‐quality tests were poor. The patients rated themselves on a higher functional level in the self‐reported tests than was observed objectively in the performance‐based tests. A possible reason for this is that the patients may have been unaware they modified their performance to adjust for physical decline, and consequently overestimate their physical condition. This result underlines the importance of both performance‐based and self‐reported tests as complementary tools in a rehabilitation process. Copyright © 2006 John Wiley & Sons, Ltd.
Tests and finite element models of wood light‐frame shear walls with openings
Authors: Doudak G. , Smith I. , McClure G. , Mohammad M. , Lepper P. 
Published: November 2006

AbstractShear walls are the primary means by which low and medium rise wood light‐frame buildings resist effects of lateral loads caused by wind, seismic or other events. Traditionally, adequacy of shear walls has been a minor concern because wood light‐frame buildings tended to be small, their shapes were regular, the amount of external and interior walls available to resist lateral forces was considerable, and the number and extent of openings in walls was limited. In modern times however, changes in the range of wood‐based construction products used, changes in construction detailing, increased geometric irregularity of buildings, more open interiors, and more numerous and larger wall openings, has raised concerns about the lateral resistance of wood frame buildings. Shear walls and how they interact with the rest of the system needs to be properly understood. They should be analysed based on generalized engineering principles that are comprehensively validated.This paper addresses proper understanding of wood light‐frame shear walls and engineering models for their analysis. Focus of analysis is on detailed finite element models suitable for representing shear walls with openings. Predictive abilities of models are verified against results of specially designed laboratory tests on shear wall segments containing a window or door opening and different hold‐down construction detailing. There is no intent that finite element models need be adopted by structural designers. Rather, the purpose of such models is that once rigorously verified they provide a benchmark against which the acceptability of simpler ‘design level’ models can be rationally assessed.Very good agreement exists between finite element models presented here and test results for shear walls loaded to destruction, with correct prediction of failure mechanisms for different configurations. Both experiments and modelling clearly demonstrate that both stiffness and strength of shear walls reduces disproportionately in relation to the extent of openings in them. This suggests that neither simplistic conceptualization of how shear walls behave nor simple design practices will lead to solutions that are both economic and safe, across a broad range of situations. However, comparison of test results and model predictions with state‐of‐the‐art design code rules indicates that the code rules quite accurately predict actual strengths of the shear walls tested by the authors.Further work is required to elucidate fully reliable design practices for buildings containing wood light‐frame shear walls. Emphasis within this will need be on the question of how to apportion lateral loads between various shear walls within a complete building.
Effect of exchange and dipolar interactions on the hysteresis of magnetic nanoparticle systems
Authors: Du H. F. , Du A. 
Published: November 2006

AbstractThe dependence of remanence and coercivity on the exchange and dipolar fields in a three‐dimensional simple cubic assembly of nanoparticles is studied by a modified Monte Carlo method in which the thermal fluctuation of magnetic moments of nanoparticles is completely considered. The long‐range dipolar interaction is summed directly in real space during the simulation. It is found that the dipolar field elongates the hysteresis loop horizontally, but the exchange field elongates it vertically. The competition between dipolar and exchange interparticle interactions leads to complex dependences of the remanence and coercivity on the exchange and dipolar fields at low temperature. Both remanence and coercivity decrease with the increase of temperature. Some results are in agreement with the experimental measurements. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Elementary energy bands in the band structure of AIV, AIIIBV crystals and superlattices built upon them
Authors: Bercha D. M. , Glukhov K. E. , Sznajder M. 
Published: November 2006

AbstractA concept of the elementary energy bands was applied to interpret the electronic energy spectra of crystals from the cubic system and the superlattices (GaAs)M /AlAsM (M = 5, 10), (Si)10/(Ge)10 built upon them. Based upon this example, it was shown that the elementary energy bands concept elaborated in the empty‐lattice approximation allows one to predict the symmetry and topology of the valence band of artificial periodic systems as well as the spatial valence‐electron density distribution in a unit cell of those systems. A verification of this conclusion was confirmed by the ab‐initio band‐structure calculations of the superlattices mentioned above. An energy‐structural factor was found that joins two elementary energy bands characteristic for Td2 symmetry crystals into a physical complex that is related to the elementary energy band of the Oh7 symmetry crystals. This relationship between the elementary energy bands was utilized to find the actual Wyckoff position in the superlattice's unit cell responsible for the spatial electron density distribution. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High pressure studies of radiative recombination mechanisms in InN
Authors: Suski T. , Franssen G. , Teisseyre H. , Khachapuridze A. , Dmowski L. H. , Plesiewicz J. A. , Kamińska A. , Lu H. , Schaff W. 
Published: November 2006

AbstractReported hydrostatic pressure measurements of Hall electron concentration and Hall mobility of InN suggest the presence of a localized donor state in the conduction band. Since localized‐state emission is rather inefficient, the involvement of such a localized state would be highly inadvantageous for device applications. Pressure‐dependent photoluminescence (PL) experiments of InN epilayers show PL pressure coefficients dE E/dp of 30.7 ± 2.0 meV/GPa and 21.4 ± 3.0 meV/GPa for InN epilayers with electron concentration of ∼5 × 1018 cm–3 and ∼5 × 1017 cm–3, respectively. These values are comparable with the InN band gap pressure coefficient dE G/dp of ∼25–30 meV/GPa (indicating regular band‐to‐band emission), and differ significantly from the value of 5–10 meV/GPa that should be expected in the case of localized‐state emission. Therefore, in the presented experiments no evidence of the involvement of localized donor states in radiative recombination processes in InN is found. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Variation of the Jahn–Teller distortion with pressure in perovskite layers A2CuCl4. Influence on the charge‐transfer band
Authors: Rodríguez F. , Aguado F. , Valiente R. , Hanfland M. , Itiè J. P. 
Published: November 2006

AbstractThis work investigates the variation of the first charge‐transfer (CT) transition with pressure in the A2CuCl4 layered perovskites, in terms of structural changes, in particular, the local structure of the (CuCl6)4– octahedra. We show that pressure partially reduces the Jahn–Teller distortion. The decrease of the axial Cu–Cl distance, R ax, is an order of magnitude bigger than the decrease of the equatorial distance, R eq, but the in‐plane Cu–Cu distance reduction is almost twice that the sum of R ax and R eq, thus indicating pressure‐induce tilts. This phenomenon avoids suppression of the JT effect, keeping the (CuCl6)4– axial distortion above 10 GPa. Both the partial reduction of the JT distortion and tiliting can account for the CT redshift induced by pressure. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pressure and temperature tuning of laser diodes
Authors: Trzeciakowski W. , Bercha A. , Dybala F. , Bohdan R. , Adamiec P. , Mariani O. 
Published: November 2006

AbstractPressure and temperature change the bandgap of III–V semiconductors and therefore they shift the gain spectrum of laser diodes. With 20 kbar pressure (achievable in a liquid pressure cell) we can increase the energy of the laser emission by about 200 meV for lasers grown on GaAs, InP, or GaSb. The main physical limitation of pressure tuning for shorter wavelengths (i.e. between 600 and 800 nm) is the reduction of indirect gap (Γ–X) in the barriers and claddings of the laser structure, leading to strong increase of leakage and threshold currents. In this wavelength range temperature tuning seems more practical. Cooling down the laser from room temperature (300 K) to about 100 K we should be able to increase the emission energy by about 80 meV. The combination of pressure/temperature tuning with tuning by external grating turned out to combine the merits of both methods: wide spectral range, narrow linewidth, stable emission wavelength. The method seems promising although several issues still have to be addressed like the reliability of lasers and pressure cells after multiple pressure cycles, stability of coupling between the laser diode and fiber under high pressure etc. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of applied hydrostatic pressure on the e–h ground transition in self‐assembled InAs/GaAs quantum lens
Authors: Rodríguez Arezky H. , Duque C. A. , Trallero‐Giner C. , Vázquez G. J. , Castillo‐Mussot M. del , Porras‐Montenegro N. 
Published: November 2006

AbstractA theoretical study of the e–h ground transition in self‐assembled InAs/GaAs quantum dots under hydrostatic pressure P is performed. The quantum dots have lens shape geometry of maximum height b and circular cross section or radius a with b < a. In the framework of the envelope‐function approximation the electronic states are evaluated as a function of the finite wall potentials, hydrostatic pressure and different lens geometry b /a. It is assumed that the increase of P keep constant the geometrical lens ratio b /a. The pressure dependence of all parameters entering into the description of the e–h transition have been taken into account. The results obtained taking the finite barrier are compared with the infinite model. It is shown that the variation of the e–h ground transition can be modelled using the simple infinite hard wall model with an effective dot radius as a fitting parameter. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The influence of pressure on the birefringence in semiconductor compounds ZnS, CuGaS2, and InPS4
Authors: Lavrentyev A. A. , Gabrelian B. V. , Kulagin B. B. , Nikiforov I. Ya. , Sobolev V. V. 
Published: November 2006

AbstractUsing the modified method of augmented plane waves and the code WIEN2k the calculations of the electron band structure, densities of electron states, and imaginary part of dielectric response function were carried out for different polarization of the vector of electrical field εxx and εzz for the semiconductor compounds ZnS, CuGaS2, and InPS4. The calculations were performed both for undisturbed crystals and for distorted crystals due to the applied pressure. The compounds studied have the similar crystallographic structures: ZnS – sphalerite, CuGaS2 – chalcopyrite, and InPS4 – twice defective chalcopyrite. It is known, that in cubic ZnS there is no birefringence, whereas in CuGaS2 and InPS4 there is one. But CuGaS2 has so called isotropic point (where εxx = εzz) in the visible optical range, and InPS4 has no such point. Our calculations of εxx and εzz have shown that in ZnS under the pressure the isotropic points arise, but in InPS4 they do not exist. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)