bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of cardiac performance by abdominal fetal ECG in twin‐to‐twin transfusion syndrome
Authors: Velayo Clarissa , Calvo Jesus Rodriguez , Sato Naoaki , Kimura Yoshitaka , Yaegashi Nobuo , Nicolaides Kypros 
Published: August 2012

ABSTRACTObjectiveTo investigate fetal cardiac performance by abdominal fetal electrocardiography (ECG) in monochorionic diamniotic pregnancies with twin‐to‐twin transfusion syndrome (TTTS‐MCDA).MethodsAbdominal fetal ECG was attempted in 16 singleton, 21 non‐TTTS‐MCDA, and 14 TTTS‐MCDA pregnancies at 16–27 weeks' gestation. Standard ECG parameters were compared across study groups and evaluated for their correlation with Doppler ultrasound indices.ResultsClear P‐QRST complexes were recognized in all cases. In the TTTS‐MCDA pregnancies, the QT interval and QTc were significantly longer than in both singletons and the non‐TTTS‐MCDA pregnancies (p = 0.002 and p = 0.0002, respectively), whereas in the recipient fetus, both the PR interval and PR/RR were significantly longer when compared with all other study groups (p = 0.019 and p = 0.012, respectively). Further comparison with Doppler ultrasound indices yielded significant reciprocal correlations between ductus venosus pulsatility index and the QT interval (r = 0.552, p = 0.041) and between umbilical artery pulsatility index and PR/RR (r = 0.654, p = 0.011) both demonstrated in recipient fetuses alone.ConclusionsAbdominal fetal ECG is feasible in second‐trimester twin pregnancies. In TTTS, there is evidence of a higher risk of cardiac dysfunction in the recipient twin. © 2012 John Wiley & Sons, Ltd.
Desire for formal psychological support among caregivers of patients with cancer: prevalence and implications for screening their needs
Authors: Merckaert Isabelle , Libert Yves , Lieutenant Frédérique , Moucheux Angélique , Farvacques Christine , Slachmuylder Jean‐Louis , Razavi Darius 
Published: August 2012

AbstractObjectiveTo investigate the prevalence of desire for formal psychological support of primary caregivers of patients with cancer and to identify caregivers' and patients' socio‐demographic and psychological characteristics as well as patients' disease‐related characteristics associated with this desire.MethodsThis is a multicenter, cross‐sectional study assessing desire for formal psychological support among consecutive primary caregivers of patients with cancer. Patients and caregivers completed the Hospital Anxiety and Depression Scale and reported their desire for formal psychological support.ResultsTwo‐hundred and eighty‐two patient–caregiver dyads were assessed. Forty percent of patients had breast cancer, 16% had a hematologic cancer, 12% had a gastrointestinal cancer, and 32% had another solid tumor. Nineteen percent of caregivers reported desiring formal support, and 54% experienced moderate to high levels of distress. Regression analysis showed that caregivers' desire for formal support was negatively associated with caregivers' age (Exp(B) = 0.95; p < 0.001) and education levels (Exp(B) = 0.35; p = 0.032) and positively with caregivers' level of distress (Exp(B) = 1.08; p < 0.001) and with patients' desire for formal psychological support (Exp(B) = 2.54; p = 0.008). These variables only predicted 25% of caregivers who desire formal support.ConclusionsOne out of five caregivers desires formal psychological support although one out of two caregivers experiences significant levels of distress. The weak association between caregivers' desire for formal support and distress emphasizes the need to implement systematic screenings of both their distress and their desire for formal psychological support in oncology.Copyright © 2012 John Wiley & Sons, Ltd.
Moving the Field into the Lab: Simulation of Water and Heat Transport in Subarctic Peat
Authors: Nagare Ranjeet M. , Schincariol Robert A. , Quinton William L. , Hayashi Masaki 
Published: August 2012

ABSTRACTLarge climate chambers are suitable to simulate, at or close to field scale, the annual freezing and thawing of layered peat in subarctic active layers above permafrost. An experiment in a climate chamber at the University of Western Ontario was designed to freeze and thaw four peat cores 60 cm in diameter. This paper describes the climate chamber and experimental setup, and evaluates their ability to maintain one‐dimensional change in soil moisture and temperature profiles. Preliminary results on soil water content (liquid and total) indicate that active‐layer freezing resulted in an upward movement of water towards a freezing front that propagated downward. The physical simulations will contribute towards improving conceptual and mathematical hydrological models for permafrost regions. Copyright © 2012 John Wiley & Sons, Ltd.
The inter‐observer variation of chest radiograph reading in acute lower respiratory tract infection among children
Authors: Xavier‐Souza Gabriel , Vilas‐Boas Ana Luisa , Fontoura Maria‐Socorro Heitz , Araújo‐Neto César Augusto , Andrade Sandra C. S. , Cardoso Maria‐Regina Alves , Nascimento‐Carvalho Cristiana Maria ,   the PNEUMOPAC‐Efficacy Study Group
Published: August 2012

AbstractThis study assessed the inter‐observer agreement in the interpretation of several radiographic features in the chest radiographs (CXR) of 803 children aged 2–59 months with non‐severe acute lower respiratory tract infection (ALRI). Inclusion criteria comprised: report of respiratory complaints, detection of lower respiratory findings, and presence of pulmonary infiltrate on the CXR taken on admission and read by the pediatrician on duty. Data on demographic and clinical findings on admission were collected from children included in a clinical trial on the use of amoxicillin (ClinicalTrials.gov Identifier NCT01200706). CXR was later read by two independent pediatric radiologists blinded to clinical information and pneumonia was finally diagnosed if there was agreement on the presence of pulmonary infiltrate or pleural effusion. The kappa index (κ) of agreement was calculated. The radiologists agreed that 774 (96.4%) and 3 (0.4%) CXR were appropriate or inappropriate for reading, respectively, and that 222 (28.7%) and 459 (59.3%) CXR presented or did not present pneumonia. In intent to treat analysis, that is, considering the 803 enrolled patients, κ for the presence of pneumonia was 0.725 (95% CI: 0.675–0.775). The overall agreement was 78.7% (normal CXR [n = 385, 60.9%], pneumonia [n = 222, 35.1%], other radiological diagnosis [n = 22, 3.5%], inappropriate for reading [n = 3, 0.5%]). The most frequent radiological findings were alveolar infiltrate (33.2%) and consolidation (32.9%) by radiologist 1 and consolidation (28.3%) and alveolar infiltrate (19.3%) by radiologist 2. Concordance for consolidation was 86.7% (k = 0.683, 95%CI: 0.631–0.741). Agreement was good between two pediatric radiologists when diagnosis of pneumonia among children with non‐severe ALRI was compared. Pediatr Pulmonol. 2013; 48:464–469. © 2012 Wiley Periodicals, Inc.
Evaluation of a cystic fibrosis transition program from pediatric to adult care
Authors: Chaudhry Sarah R. , Keaton Meghan , Nasr Samya Z. 
Published: August 2012

AbstractPurposeAs the cystic fibrosis (CF) patient population median survival increase, the need for transitioning their care to adult care centers increase as well. We have a structured transition program since the early 1980s. The purpose of this study is to evaluate the experiences and opinions of patients in our adult CF center who went through a formal transition versus those who did not, in an attempt to evaluate the overall process and to identify means for improvement.MethodsA questionnaire was given to adult CF patients at the University of Michigan during a clinic visit or inpatient hospitalization, after consent was obtained. Inclusion criteria included diagnosis of CF in childhood, previous care in a pediatric center, and current participation in our adult CF clinic.ResultsA total of 91 patients completed the questionnaire. 44 went through our structured transition program. On average, patients who participated in a formal transition process had higher satisfaction with both CF programs, perceived health status, and independence but no differences in their level of anxiety about transferring to the adult program. Patient opinions regarding when to transfer care were considered more often in patients who participated in a transition program (88% vs. 62% and P = 0.02).ConclusionAlthough structured transitions programs do not appear to decrease patient anxiety during this stressful period, it does appear to improve patient satisfaction, perceived health status, and independence. These findings suggest that establishing a transition program could be important in optimizing patient health, continuity of care and improving adherence. Pediatr Pulmonol. 2013; 48:658–665. © 2012 Wiley Periodicals, Inc.
Synthesis and characterization of CdSe/ZnS core‐shell quantum dots immobilized on solid substrates through laser irradiation
Authors: György E. , del Pino A. Pérez , Roqueta J. , Ballesteros B. , Miguel A. S. , Maycock C. , Oliva A. G. 
Published: August 2012

AbstractCdSe/ZnS core‐shell quantum dots (QDs) have been immobilized onto solid substrates by matrix assisted pulsed laser evaporation (MAPLE). An UV KrF* (λ = 248 nm, τFWHM ≅ 25 ns) excimer laser source was used for irradiations of the composite MAPLE targets. The targets were prepared by the dispersion of the CdSe/ZnS QDs in a solvent with high absorption at the incident laser radiation. The dependence of the surface morphology, crystalline structure, chemical composition, and functional properties of the laser transferred CdSe/ZnS QDs on the processing conditions as incident laser fluence value and ambient atmosphere inside the irradiation chamber was investigated. The possible physical mechanisms implied in the laser ablation process were identified.
In situ boron doping during heteroepitaxial growth of diamond on Ir/YSZ/Si
Authors: Sartori André F. , Fischer Martin , Gsell Stefan , Schreck Matthias 
Published: August 2012

AbstractIn situ boron doping of heteroepitaxial diamond films grown by microwave plasma chemical vapor deposition on Ir/YSZ/Si (001) is investigated. The study comprises the analysis of the gas phase by optical emission spectroscopy (OES) and measurements of B doped films by secondary ion mass spectroscopy (SIMS), cathodoluminescence (CL), and X‐ray diffraction (XRD). The OE intensity of BH species scales linearly with the concentration of the boron precursor trimethylboron (TMB) in the feed gas. Addition of CO2 as an oxygen source causes a proportional reduction of the BH signal. At a ratio C:O = 1, a reduction factor of ∼50 is obtained. It is shown for two diamond samples that the boron incorporation drops nearly identical to the BH emission intensity. We conclude that the influence of oxygen on boron incorporation is a pure gas phase effect. In contrast, CN and BH emission indicate a negligible interaction between N2 and TMB added to the feed gas. At the same time, preliminary growth rate measurements show that the boron background pressure in the chamber after growth with TMB completely cancels the growth acceleration by nitrogen up to N2 concentrations of 100 ppm which points to the dominance of surface processes. Heteroepitaxial diamond films grown on Ir at 50 mbar between 720 and 900 °C contain high intrinsic stress that varies from −2.2 GPa compressive at the lowest to slightly tensile at the highest deposition temperature. The observed behavior is similar to former work at 200 mbar in which effective climb of dislocations was suggested as responsible mechanism. Addition of boron rather enhances the stress formation than causing a relaxation. The B concentration in the heteroepitaxial films is deduced by SIMS, CL, and XRD and correlated with the TMB concentration in the gas phase.
Natural aging of Mg–Gd and Mg–Tb alloys
Authors: Čížek Jakub , Smola Bohumil , Stulíková Ivana , Hruška Petr , Vlach Martin , Vlček Marián , Melikhova Oksana , Procházka Ivan 
Published: August 2012

AbstractSubstantial natural aging occurring on the time scale of less than 1 month was observed in solution‐treated Mg–Gd and Mg–Tb alloys. Solution treatment at 500 and 530 °C for Mg–Gd and Mg–Tb alloys, respectively, leads to dissolution of Gd or Tb in the Mg matrix. By quenching of solution‐treated alloys to room temperature a supersaturated solid solution of Gd or Tb in Mg was formed. During subsequent aging at ambient temperature the hardness of quenched alloys increases, most probably, due to agglomeration of dissolved Gd or Tb atoms into small clusters. Positron lifetime spectroscopy combined with coincident Doppler broadening revealed that quenched alloys contain vacancies bound to Gd or Tb atoms. Quenched‐in vacancies facilitate clustering of Gd or Tb solutes and disappear from the samples when the clusters are fully developed.
An exploration of the equivalent weights particle filter
Authors: Ades M. , van Leeuwen P. J. 
Published: August 2012

AbstractParticle filters are fully nonlinear data assimilation techniques that aim to represent the probability distribution of the model state given the observations (the posterior) by a number of particles. In high‐dimensional geophysical applications, the number of particles required by the sequential importance resampling (SIR) particle filter (in order to capture the high‐probability region of the posterior) is too large to make them usable. However particle filters can be formulated using proposal densities, which give greater freedom in how particles are sampled and allow for a much smaller number of particles. Here a particle filter is presented which uses the proposal density to ensure that all particles end up in the high‐probability region of the posterior probability density function. This gives rise to the possibility of nonlinear data assimilation in large‐dimensional systems. The particle filter formulation is compared to the optimal proposal density particle filter and the implicit particle filter, both of which also utilise a proposal density. We show that, when observations are available every time step, both schemes will be degenerate when the number of independent observations is large, unlike the new scheme. The sensitivity of the new scheme to its parameter values is explored theoretically and demonstrated using the Lorenz (1963) model. Copyright © 2012 Royal Meteorological Society
Preconditioning of variational data assimilation and the use of a bi‐conjugate gradient method
Authors: El Akkraoui Amal , Trémolet Yannick , Todling Ricardo 
Published: August 2012

AbstractPresently, a preferred minimization for strong‐constraint four‐dimensional variational (4D‐Var) assimilation uses a Lanczos‐based conjugate gradient (CG) algorithm. This requires the availability of a square‐root of the background‐error covariance matrix (B). In the context of weak‐constraint 4D‐Var, this requirement might be too restrictive for the formulations of the model error term. It might therefore be desirable to avoid a square‐root decomposition of the augmented background term. An appealing minimization scheme is the double CG minimization employed, for example, in the grid‐point statistical interpolation (GSI) analysis. Realizing the double CG algorithm is a special case of the more general bi‐conjugate gradient (BiCG) method for solving non‐symmetric problems, the present work introduces a Lanczos‐based preconditioning strategy when B, instead of its square‐root, is used initially. Implementation of the scheme is done in the context of the GSI analysis system, and preliminary experiments are presented using its 3D‐Var version. Comparison of the Lanczos‐based CG and the BiCG shows that the algorithms converge at the same rate and to the same solution. Despite the additional computational cost, the importance of the re‐orthogonalization step is also shown to be fundamental to any of these CG algorithms. Furthermore, when using the Hessian eigenvectors for preconditioning, the BiCG behaviour is shown to be comparable to that of the Lanczos‐CG algorithm. Both schemes construct the same approximation of the Hessian with the same number of eigenvectors, and benefit in the same way from the reduction of the condition number. The efficiency, computational cost, and stability of the three algorithms are discussed. Copyright © 2012 Royal Meteorological Society
Visualizing the Growth and Dynamics of Liquid‐Ordered Domains During Lipid Bilayer Folding in a Microfluidic Chip
Authors: Kendall Eric L. , Shao Chenren , DeVoe Don L. 
Published: August 2012

AbstractA microfluidic platform enabling optical monitoring of bilayer lipid membrane formation by a new monolayer folding process is described. The thermoplastic chips integrate dried lipid films that are rehydrated by microfluidic perfusion, which enables delivery of lipid‐laden air bubbles across a membrane‐supporting aperture. As in traditional Montal–Mueller bilayer formation, lipid monolayers are delivered independently to each side of the aperture, thereby allowing asymmetric lipid composition in the resulting bilayer to be achieved. Confocal microscopy is used to image the monolayer folding process, and reveals the growth and dynamics of asymmetric liquid‐ordered domains during bilayer stabilization.
Mechanical Testing and Finite Element Simulations for the Use of Cellular Metals as Car Seat Components
Authors: Nesic Srecko , Unruh Klaus , Michels Wilhelm , Krupp Ulrich 
Published: August 2012

AbstractDue to the high energy absorption capacity at constant compressive stress level, cellular metals may be used as crash‐energy‐absorbing elements in autobody structures or car components, e.g., car seats. Modern car seats do not only have a high technical functionality, like electronic positioning, heating, and ventilation systems; in the case of a crash they must protect the passenger. The present paper deals with an analysis of potentially suitable cellular metals for integration in car seats. By means of different quasi‐static tests, i.e., compression, tensile, shear, and bending testing of several candidate metal foams and foam sandwich structures, the general material properties, the damage behavior and the reproducibility of mechanical data are tested. The results, which include optical 3D strain distribution measurements of the chosen cellular metals during quasi‐static testing, are implemented in the engineering design of structural car seat components and finite element calculations to simulate the crash behavior. Objective of the work is the derivation of robust and reliable mechanical testing procedures and standards as well as an improved understanding of the damage mechanisms of cellular metals under different loading conditions to finally derive design guidelines for cellular metals.
Finite Element Analysis of Glass Fiber‐Reinforced Polyamide Engine Oil Pan Subjected to Localized Low Velocity Impact from Flying Projectiles
Authors: Mouti Zakaria , Westwood Keith , Long Darren , Njuguna James 
Published: August 2012

AbstractThis paper investigates low velocity impact involving a glass fiber‐reinforced polyamide engine oil pan as part of a complete new development of thermoplastic components. The assessment of the impact resistance has driven the need to employ LS DYNA for finite element modeling in order to benchmark and predict the strength and fracture behavior of stressed plastic parts. In order to develop a reliable predictive capability and to validate simulations, complete components were manufactured by injection molding techniques for the experimental samples. Low velocity impact investigations were carried out using a gas gun and a falling weight tester in order to simulate impact events to which the oil pan is subjected whilst in operational service. This was intended to point out damage tolerance and failure mechanisms likely to occur in the structure. The study results show the significant contribution of the design in terms of shock absorption. Specific oil pan design with protective ribbing combined with a superior material considerably improves the impact resistance. The paper provides results and discussions on experimental and finite element analysis investigations before concluding with some remarks.
Computational and Experimental Analysis of Carbo‐Nitride Precipitation in Tempered Martensite
Authors: Zamberger Sabine , Wojcik Tomasz , Klarner Jürgen , Klösch Gerald , Schifferl Herbert , Kozeschnik Ernst 
Published: August 2012

AbstractThe present work describes the analysis of carbo‐nitride precipitation kinetics in tempered martensite of Nb–Ti‐microalloyed steel with a carbon content of 0.3 wt%. Based on the information obtained from transmission electron microscopy and scanning electron microscopy, a computational simulation procedure is developed within the software package MatCalc, which is capable of describing the experimental results in terms of the number density, composition, and type of precipitate phases. No explicit fitting parameters are used in the computer simulation. The input data is entirely based on independent physical or microstructural parameters. To determine the chemical composition and type of precipitates, energy dispersive X‐ray spectroscopy and selected area electron diffraction are utilized. The simulation results and the experimentally obtained information are in good agreement.
Resonance energy flow dynamics of coherently delocalized excitons in biological and macromolecular systems: Recent theoretical advances and open issues
Authors: Jang Seogjoo , Cheng Yuan‐Chung 
Published: August 2012

AbstractRecent experimental and theoretical studies suggest that biological photosynthetic complexes utilize the quantum coherence in a positive manner for efficient and robust flow of electronic excitation energy. Clear and quantitative understanding of such suggestion is important for identifying the design principles behind efficient flow of excitons coherently delocalized over multiple chromophores in condensed environments. Adaptation of such principles for synthetic macromolecular systems has also significant implication for the development of novel photovoltaic systems. Advanced theories of resonance energy transfer are presented, which can address these issues. Applications to photosynthetic light harvesting complex systems and organic materials demonstrate the capabilities of new theoretical approaches and future challenges.This article is categorized under:

Molecular and Statistical Mechanics > Molecular Dynamics and Monte-Carlo Methods
Comparing cytosolic expression to peroxisomal targeting of the chimeric L1/L2 (ChiΔH‐L2) gene from human papillomavirus type 16 in the methylotrophic yeasts Pichia pastoris and Hansenula polymorpha
Authors: Smith J. J. , Burke A. , Bredell H. , van Zyl W. H. , Görgens J. F. 
Published: August 2012

AbstractThe chimeric ChiΔH‐L2 gene from human papillomavirus type 16, consisting of structural proteins L1 and L2, was successfully expressed in the cytosol of both Pichia pastoris and Hansenula polymorpha during methanol induction. In addition, a novel approach was employed whereby ChiΔH‐L2 was targeted to the peroxisome using peroxisomal targeting sequence 1 (PTS1) to compare ChiΔH‐L2 yields in the peroxisome vs the cytosol. The ChiΔH‐L2 gene was yeast‐optimized and cloned into plasmids aimed at genomic integration. Levels of intracellular ChiΔH‐L2 accumulation in the cytosol were highest in P. pastoris KM71 strain KMChiΔH‐L2 (1.43 mg/l), compared to the maximum production level of 0.72 mg/l obtained with H. polymorpha. ChiΔH‐L2 targeting to the peroxisome was successful; however, it appeared to negatively affect ChiΔH‐L2 production in both P. pastoris and H. polymorpha. Copyright © 2012 John Wiley & Sons, Ltd.