365 research outputs found
Electric field penetration in Au/Nb:SrTiO3 Schottky junctions probed by bias-dependent internal photoemission
Demographic Predictors of Adult Behaviors in the Pediatric Postoperative Environment
Over 85% of children experience postoperative pain. If poorly treated, pediatric postoperative pain may lead to various negative health outcomes. Adult behaviors may be associated with child experiences in the postoperative environment. For example, adult behaviors such as distraction, humor, and coping advice divert a childâs attention away from their pain and thus, may significantly reduce child postoperative distress. In contrast, adult behaviors such as empathy, reassurance, and apology direct a childâs attention towards their pain which may increase a childâs overall postoperative distress. Moreover, patient demographic factors, like child ethnicity, may significantly alter the frequency of use of these adult behaviors. Therefore, this study aimed to determine which participant demographic factors are associated with the use of certain adult behaviors in response to child postoperative distress. This study included children ages 2 to 10 years old (N=112) undergoing elective surgery at the Childrenâs Hospital of Orange County. Participant demographics including ethnicity and race were collected prior to surgery. Nurse, parent, and child postoperative behavioral interactions were video recorded in the Post Anesthesia Care Unit (PACU). From these video recordings, adult behaviors were coded for their frequency of use. Multiple regressions analyses showed that adults were more likely to use humor with Non-Hispanic White children compared to Hispanic children (b = 0.393, p = 0.049). Moreover, fathers were marginally more likely to use empathy, reassurance, and apology with Hispanic children compared to Non-Hispanic White children (b = 0.249, p = 0.05). These results suggest that Hispanic and Non-Hispanic White children may receive different behavioral treatment in response to their postoperative distress. Implications for these findings suggest that child ethnicity may be predictive of different adult PACU behaviors which may illustrate how cultural differences can influence the child postoperative experience
Emotion Regulation and Positive Affect in the Context of Salivary Alpha-Amylase Response to Pain in Children with Cancer: Physiology, Self-Report, and Behavior
Children with cancer are repeatedly exposed to aversive stimuli including painful procedures. Therefore, emotional regulation techniques may prove useful during such experiences and contribute to pain resilience. This study aimed to determine whether three different emotional regulation strategies (distraction, reappraisal and reassurance) impacted physiological, self- reported and behavioral pain responses in pediatric patients with cancer ages 6 to 18 years (N = 73). The cold pressor task (CPT), an experimental task in which pain is induced by having participants place their hand in cold water, was used to examine pain responses. Patients placed their hand in 7 degree Celsius water for up to 4 minutes. Saliva samples were collected 15 minutes before, immediately after, and then 15 minutes after the CPT. Saliva samples were assayed for alpha amylase, a proxy for sympathetic nervous system activation. Self-reported pain severity was measured upon hand removal. Pain tolerance was assessed by length of time participants kept their hand in the water. Children in the reassurance condition exhibited salivary alpha amylase levels that continued to rise post completion of the CPT as compared to children in the distraction (Beta = -1.68, SE = 0.73, z = -2.30, p = .021, 95% CI [-3.10, -0.25]) and reappraisal (Beta = -1.24, SE = 0.72, z = -1.73, p = .084, 95% CI [-2.65, 0.17]) conditions. However, when self-reported pain and behavior were examined, no differences in pain severity (Wald Chi-squared (2) = 2.47, p = .292), or pain tolerance (Wald Chi-squared (2) = 1.38, p = 0.502) among the emotional regulation strategies were observed. Thus, significant findings were present for physiological markers of distress, but not for self-reported and behavioral measures. These findings suggest that in terms of physiological measures, specific emotional regulation strategies, such as distraction and reappraisal, may be more beneficial in reducing stress responses to painful medical procedures in pediatric patients with cancer as compared to reassurance. These results also demonstrate the importance of examining physiological outcomes in addition to self-report and behavioral outcomes
Pediatric Asthma and Psychological Resilience: Examining Whether Family Functioning and Social Support Relate to Asthma Symptoms and Lung Function
Upwards of 6 million children in the United States are afflicted with pediatric asthma. While previous research has linked asthma to multiple contributing biological and environmental factors, recent research suggests that psychological and social factors may have an impact on physiological outcomes of asthma like lung function and lung inflammation. Therefore, we suggest the need to study the impact of positive psychological factors such as a well-functioning family environment and beneficial social support on symptoms and lung function of children diagnosed with asthma. In the present pilot study, we recruited a total of 15 children with a confirmed asthma diagnosis and their parents from the Division of Pulmonology at the Childrenâs Hospital of Orange County. Participants were asked to complete an initial baseline assessment as well as ecological momentary assessments four times a day for seven days followed by a final follow up survey. Asthma symptoms and pulmonary function were measured using a 7-item Asthma Control Diary, and peak expiratory flow (PEF) values were gathered using data from self-administered spirometer recordings during the ecological momentary assessment portion of the study. This pilot study demonstrates the feasibility in collecting ecological momentary assessments surrounding positive psychological factors. Further, in testing the associations between family functioning and social support on childrenâs asthma symptoms and lung function, children who received more support from teachers (b = 0.03, t = 2.34, p = 0.048) and close friends (b = 0.04, t = 3.88, p = 0.006) had worse symptoms and lung function. Family functioning was not significantly associated with asthma symptoms and lung function (b = -0.00, t = -0.03, p = 0.975). Based on the results obtained, significant associations were only found in some aspects of social support. Interestingly, it seems as though children with more social support had worse asthma symptoms and lung function. This negative association might be an issue of reverse causality in which children who need more assistance receive more support. Next steps in this work include testing these associations in a larger-scale study. In sum, as pediatric asthmaâs prevalence continues to rise, future studies should further examine the relationship between positive psychological factors and childrenâs asthma resilience
Rigorous Multicomponent Reactive Separations Modelling : Complete Consideration of Reaction-Diffusion Phenomena
This paper gives the first step of the development of a rigorous multicomponent reactive separation model. Such a model is highly essential to further the optimization of acid gases removal plants (CO2 capture, gas treating, etc.) in terms of size and energy consumption, since chemical solvents are conventionally used.Firstly, two main modelling approaches are presented: the equilibrium-based and the rate-based approaches. Secondly, an extended rate-based model with rigorous modelling methodology for diffusion-reaction phenomena is proposed. The film theory and the generalized Maxwell-Stefan equations are used in order to characterize multicomponent interactions. The complete chain of chemical reactions is taken into account. The reactions can be kinetically controlled or at chemical equilibrium, and they are considered for both liquid film and liquid bulk. Thirdly, the method of numerical resolution is described. Coupling the generalized Maxwell-Stefan equations with chemical equilibrium equations leads to a highly non-linear Differential-Algebraic Equations system known as DAE index 3. The set of equations is discretized with finite-differences as its integration by Gear method is complex. The resulting algebraic system is resolved by the Newton- Raphson method. Finally, the present model and the associated methods of numerical resolution are validated for the example of esterification of methanol. This archetype non-electrolytic system permits an interesting analysis of reaction impact on mass transfer, especially near the phase interface. The numerical resolution of the model by Newton-Raphson method gives good results in terms of calculation time and convergence. The simulations show that the impact of reactions at chemical equilibrium and that of kinetically controlled reactions with high kinetics on mass transfer is relatively similar. Moreover, the Fickâs law is less adapted for multicomponent mixtures where some abnormalities such as counter-diffusion take place
Optically tuned dimensionality crossover in photocarrier-doped SrTiO: onset of weak localization
We report magnetotransport properties of photogenerated electrons in undoped
SrTiO single crystals under ultraviolet illumination down to 2 K. By tuning
the light intensity, the steady state carrier density can be controlled, while
tuning the wavelength controls the effective electronic thickness by modulating
the optical penetration depth. At short wavelengths, when the sheet conductance
is close to the two-dimensional Mott minimum conductivity we have observed
critical behavior characteristic of weak localization. Negative
magnetoresistance at low magnetic field is highly anisotropic, indicating
quasi-two-dimensional electronic transport. The high mobility of photogenerated
electrons in SrTiO allows continuous tuning of the effective electronic
dimensionality by photoexcitation.Comment: 7 pages, 7 figure
Built-in and induced polarization across LaAlO/SrTiO heterojunctions
Ionic crystals terminated at oppositely charged polar surfaces are inherently
unstable and expected to undergo surface reconstructions to maintain
electrostatic stability. Essentially, an electric field that arises between
oppositely charged atomic planes gives rise to a built-in potential that
diverges with thickness. In ultra thin film form however the polar crystals are
expected to remain stable without necessitating surface reconstructions, yet
the built-in potential has eluded observation. Here we present evidence of a
built-in potential across polar \lao ~thin films grown on \sto ~substrates, a
system well known for the electron gas that forms at the interface. By
performing electron tunneling measurements between the electron gas and a
metallic gate on \lao ~we measure a built-in electric field across \lao ~of 93
meV/\AA. Additionally, capacitance measurements reveal the presence of an
induced dipole moment near the interface in \sto, illuminating a unique
property of \sto ~substrates. We forsee use of the ionic built-in potential as
an additional tuning parameter in both existing and novel device architectures,
especially as atomic control of oxide interfaces gains widespread momentum.Comment: 6 pages, 4 figures. Submitted to Nature physics on May 1st, 201
Parental Satisfaction of Child\u27s Perioperative Care
Background
Satisfaction in the hospital setting is an important component of both hospital funding and patient experience. When it comes to a child\u27s hospital experience, parent satisfaction of their child\u27s perioperative care is also necessary to understand. However, little research has been conducted on the predictors of this outcome. Therefore, the purpose of this current study was to validate a priori selected predictors for parental satisfaction in their child\u27s perioperative process. Methods
Eight hundred and ten pediatric patients who underwent tonsillectomy and adenoidectomy surgery and their parents were included in this study. The primary outcome was assessed using a 21âitem parent satisfaction questionnaire resulting in three satisfaction scores: overall care satisfaction, OR/induction satisfaction, and total satisfaction. Results
Descriptive statistics and correlational analysis found that sedativeâpremedication, parental presence at anesthesia induction, child social functioning, parental anxiety, and language were all significant predictors of various components of the satisfaction score. Regression models, however, revealed that only parent anxiety and child social functioning remained significant predictors such that parents who reported lower state anxiety (OR/induction satisfaction: OR = 0.975, 95% CI [0.957, 0.994]; total satisfaction: OR = 0.968, 95% CI [0.943, 0.993]) and who had higher socially functioning children (overall care satisfaction: OR = 1.019, 95% CI [1.005, 1.033]; OR/induction satisfaction: OR = 1.011, 95% CI [1.000, 1.022]) were significantly more satisfied with the perioperative care they received. Conclusion
Lower parent anxiety and higher child social functioning were predictive of higher parental satisfaction scores
Ab-initio study of BaTiO3 surfaces
We have carried out first-principles total-energy calculations of (001)
surfaces of the tetragonal and cubic phases of BaTiO3. Both BaO-terminated
(type I) and TiO2-terminated (type II) surfaces are considered, and the atomic
configurations have been fully relaxed. We found no deep-gap surface states for
any of the surfaces, in agreement with previous theoretical studies. However,
the gap is reduced for the type-II surface, especially in the cubic phase. The
surface relaxation energies are found to be substantial, i.e., many times
larger than the bulk ferroelectric well depth. Nevertheless, the influence of
the surface upon the ferroelectric order parameter is modest; we find only a
small enhancement of the ferroelectricity near the surface.Comment: 8 pages, two-column style with 4 postscript figures embedded. Uses
REVTEX and epsf macros. Also available at
http://www.physics.rutgers.edu/~dhv/preprints/index.html#pad_sur
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