bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic fracture modeling in shell structures based on XFEM
Authors: Larsson Ragnar , Mediavilla Jesus , Fagerström Martin
Published: December 2010

Through‐the‐thickness crack propagation in thin‐walled structures is dealt with in this paper. The formulation is based on the cohesive zone concept applied to a kinematically consistent shell model enhanced with an XFEM‐based discontinuous kinematical representation. The resulting formulation comprises the representation of continuous deformation, represented by midsurface placement, director and thickness inhomogeneous fields, and discontinuous deformation, represented by discontinuous placement and director fields. The shell model is implemented both for the implicit static analysis and in the context of explicit dynamic integration pertinent to impact loading, and the implementation results in a 7‐parameter solid‐shell element based on a 6‐noded triangular element. In order to properly formulate the dynamic fracture characteristics, a rate‐dependent cohesive zone model is employed with respect to, e.g. limiting crack speeds as observed experimentally. In the final example, this model has been applied to a blast loaded pressure vessel that has been experimentally tested. The results indicate that the right crack speed as well as fracture characteristics are relatively well captured. Furthermore, it appears that the discontinuous model exhibits the expected properties with respect to critical time step size in the dynamic analysis and convergence behavior towards the analytical static solution. Copyright © 2010 John Wiley & Sons, Ltd.
Direct numerical simulation of saturated deformable porous media using parallel hybrid Lattice–Boltzmann and finite element method
Authors: Khan Irfan , Aidun Cyrus K.
Published: December 2010

Numerical techniques for modeling saturated deformable porous media have mainly been based on mixture theory or homogenization techniques. However, these techniques rely on phenomenological relationships for the constitutive equations along with assumptions of homogeneous and isotopic material properties to obtain closure. Direct numerical simulations of the multiphasic problem for flow in deformable porous media avoid such assumptions and thus can provide significantly accurate understanding of the physics involved. They serve as a tool to investigate the constitutive relationships in complex geometries. They also allow the validation of the existing mixture theory models and determine their limitations.

In this work, a parallel hybrid method using Lattice Boltzmann Method (LBM) for fluid phase and Finite Element Method (FEM) for solid phase is used for direct numerical simulation of saturated deformable porous media. The method provides a number of unique features including scalability on distributed computing necessary for such a problem. The method has been validated for modeling fluid–structure interactions in complex geometries against a number of experimental and analytical solutions. Further some challenging problems has been chosen to show the capability of the method. Copyright © 2010 John Wiley & Sons, Ltd.
In vitro growth and activity of chondrocytes on three dimensional polycaprolactone/chitosan scaffolds
Authors: Jiang Xiaobing , Lu Xiaoling , Xiao Bo , Wan Ying , Zhao Yongxiang
Published: December 2010

Porous polycaprolactone/chitosan blend scaffolds with various compositional proportions were prepared using a particulate‐leaching method. The pore parameters of resultant scaffolds were found to be mainly modulated by porogen. The compressive mechanical properties and hydrophilicity of scaffolds were examined by measuring their compressive modulus and stress strength as well as swelling index. Selected chondrocytes isolated from articular cartilage of knee joints of rabbits were seeded on these scaffolds, and further in vitro cultured for various periods. The growth and activity of seeded cells were estimated by counting numbers of cells proliferated on scaffolds and measuring the amounts of proteoglycans and type II collagen synthesized by the seeded cells. It was found that some scaffolds composed of proper component ratios and having appropriate pore parameters exhibited promising characteristics for the adhesion and proliferation of seeded cells while maintaining the phenotype and activity of the cells. Copyright © 2010 John Wiley & Sons, Ltd.
BMS‐790052 – ein oral verfügbares Hepatitis‐C‐Virustatikum in der Pipeline
Authors: Schmitz Jens
Published: December 2010

In Deutschland leiden gegenwärtig ca. 500.000 Menschen an einer chronischen Hepatitis‐C‐Virus (HCV)‐Infektion. Die weltweite Prävalenz wird auf 170 Millionen Menschen geschätzt. Derzeit gilt die Behandlung mit pegyliertem Interferon‐α (PEG‐INF‐α) in Kombination mit Ribavirin über mehrere Monate als Standardtherapie. Die Ansprechrate ist jedoch bei Infektionen mit dem weitverbreiteten Virusgenotyp HCV‐1 nur ca. 50 %. Die Entwicklung von Wirkstoffen, die gegen alle HCV‐Genotypen aktiv sind, ist also dringend notwendig.
Impfstoffe gegen die Virushepatitiden A bis E. Was haben sie bewirkt, was können sie bewirken?
Authors: Jilg Wolfgang
Published: December 2010

Wir verfügen gegenwärtig über wirksame und sehr gut verträgliche Impfstoffe gegen Hepatitis A und B. Der Hepatitis‐A‐Impfstoff enthält formalininaktiviertes, adjuvantiertes Hepatitis‐A‐Virus. Die Schutzrate nach zwei Impfungen ist nahezu 100 %, die Schutzdauer beträgt mindestens 20 Jahre. Die Impfung ist in erster Linie indiziert für Reisende in Hepatitis‐A‐Endemiegebiete Afrikas, Asiens und Südamerikas.

Der Impfstoff gegen Hepatitis B besteht aus HBsAg, dem Oberflächenprotein des Hepatitis‐B‐Virus, das heute gentechnisch hergestellt wird. Auch dieser Impfstoff ist adjuvantiert. Die Grundimmunisierung mit drei Impfdosen führt in ca. 95 % der Geimpften zum Erfolg und verleiht für 10 bis 15 Jahre einen Schutz vor Infektion oder zumindest vor Erkrankung. Ob für einen lebenslangen Schutz Nachimpfungen notwendig sind, ist noch unklar. Die Impfung wird seit 1995 in Deutschland für alle Kinder im ersten Lebensjahr empfohlen. Geimpft werden sollten auch alle mit erhöhter Hepatitis‐B‐Gefährdung, z.B. medizinisches Personal. Der Hepatitis‐B‐Impfstoff schützt auch gegen das nur mit dem Hepatitis‐B‐Virus zusammen auftretende Hepatitis‐D‐Virus.

Nach wie vor gibt es keinen Impfstoff gegen Hepatitis C, dagegen wurde ein experimenteller Impfstoff gegen Hepatitis E bereits erfolgreich eingesetzt.
Leitliniengerechte Therapie der Hepatitis C. Die Eradikation von HCV als Ziel
Authors: Sarrazin Christoph , Zeuzem Stefan
Published: December 2010

Für die Hepatitis C gilt weiterhin, dass bei dem Großteil der Patienten die Infektion bisher nicht bekannt ist. Die chronische Hepatitis C stellt jedoch eine der Hauptursachen für die Leberzirrhose und das Leberzellkarzinom in Deutschland dar. Ein breites Screening mithilfe des HCV‐Antikörperassays bei Patienten mit unklar erhöhten Leberwerten bzw. unklarer Lebererkrankung aber auch bei allen Personen mit entsprechenden Risikofaktoren für die Übertragung des Virus ist daher von besonderer Wichtigkeit. Die Indikation zur antiviralen Therapie der chronischen HCV‐Infektion ist großzügig zu stellen. Die Behandlung besteht aus der kombinierten Gabe von pegyliertem Interferon alfa und Ribavirin. Auf der Grundlage von zahlreichen Studien sind Stoppregeln zur frühzeitigen Beendigung der Behandlung, sowie Regeln zur Festlegung der optimalen Therapiedauer mithilfe der Ausgangsviruslast und der HCV‐RNA‐Kinetik unter Therapie etabliert worden. Größte Bedeutung kommt dem Management von Nebenwirkungen unter der Therapie zu, um möglichst eine vollständige Therapiedosis und ‐dauer zu erreichen. Durch die aktuell in der klinischen Phase II bis III befindlichen direkt antiviralen Substanzen werden sich die Heilungsraten der Therapie in naher Zukunft wesentlich verbessern.
Continuous and high‐dose cytarabine combined chemotherapy in children with down syndrome and acute myeloid leukemia: Report from the Japanese children's cancer and leukemia study group (JCCLSG) AML 9805 down study
Authors: Taga Takashi , Shimomura Yasuto , Horikoshi Yasuo , Ogawa Atsushi , Itoh Masaki , Okada Masahiko , Ueyama Junichi , Higa Takeshi , Watanabe Arata , Kanegane Hirokazu , Iwai Asayuki , Saiwakawa Yutaka , Kogawa Kazuhiro , Yamanaka Junko , Tsurusawa Masahito
Published: December 2010

Background

The aim of the JCCLSG AML 9805 Down study was to evaluate the effect of continuous and high‐dose cytarabine combined chemotherapy on the survival outcome of acute myeloid leukemia (AML) with Down syndrome (DS).

Procedure

From May 1998 to December 2006, DS patients with newly diagnosed AML were enrolled. Remission induction therapy consisted of two courses of pirarubicin, vincristine, and continuous‐dose cytarabine (AVC1). The patients who achieved complete remission (CR) after two courses of AVC1 were subsequently treated with mitoxantrone and continuous‐dose cytarabine (MC), etoposide and high‐dose cytarabine (EC) and pirarubicin, vincristine, and continuous‐dose cytarabine (AVC2).

Results

Twenty‐four patients were enrolled. All patients were younger than 4 years and diagnosed as having acute megakaryoblastic leukemia. Twenty‐one patients achieved CR. Three patients died during remission induction therapy due to serious infection. No toxic deaths were observed during remission. All but one patient maintained CR without serious complications. The 5‐year overall and event‐free survivals were 87.5% ± 6.8% and 83.1% ± 7.7%, respectively.

Conclusions

Continuous and high‐dose cytarabine combined chemotherapy with reduced intensity would be effective in DS children with AML. Pediatr Blood Cancer 2011;57:36–40. © 2011 Wiley‐Liss, Inc.
Determining the test characteristics of claims‐based diagnostic codes for the diagnosis of venous thromboembolism in a medical service claims database
Authors: Tagalakis Vicky , Kahn Susan R
Published: December 2010

Purpose

To determine the test characteristics of diagnostic codes within a medical service claims database for deep vein thrombosis (DVT) and pulmonary embolism (PE).

Methods

The Regie de l' Assurance Maladie du Québec (RAMQ) administers the health insurance program in Québec, Canada. RAMQ claims data were obtained for subjects with objectively diagnosed DVT with or without PE who were participants in the Venous Thrombosis Outcomes (VETO) Study from April 2001 to July 2002. Using the date of DVT and PE diagnosis in the VETO record as the reference standard, the proportion of subjects correctly classified by RAMQ diagnostic codes was determined for the exact date of DVT and PE occurrence and for four expanded time windows around this date.

Results

In all, 355 VETO patients were included, 301 with DVT alone and 54 with DVT and PE. Overall, 97% of VETO cases had a RAMQ diagnostic code for DVT and 82% of VETO cases with PE had a RAMQ diagnostic code for PE. Sensitivity for DVT and PE was 52% (95% confidence interval (CI), 47–57) and 35% (95% CI, 23–49), respectively for the exact date of diagnosis, and 87% (95% CI, 83–90) and 78% (95% CI, 64–88), respectively for a 60‐day window around this date. As all VETO participants had DVT, specificity for the diagnosis of DVT could not be determined.

Conclusion

Diagnostic codes within a medical service claims database are relatively sensitive indicators for DVT and PE, and use of claims data for VTE research purposes can be considered. Copyright © 2010 John Wiley & Sons, Ltd.
Prevalence, incidence and persistence of etanercept and adalimumab in Norway 2005–2009
Authors: Mahic Milada , Skurtveit Svetlana , Selmer Randi , Rønning Marit , Furu Kari
Published: December 2010

Purpose

Examining the prevalence, incidence and persistence of use of etanercept and adalimumab in Norway during 2005–2009.

Methods

We retrieved data from the nationwide Norwegian Prescription Database (NorPD) for all individuals who were dispensed etanercept or adalimumab from pharmacies during 2005–2009. The NorPD covers the total Norwegian population in ambulatory care. Key measurements were one‐year prevalence, incidence rate and persistence (minimum refill).

Results

The one‐year prevalence for etanercept and adalimumab was 1.59‰ (n = 3840) for men and 1.85‰ (n = 4483) for women in 2009, an increase from 0.76‰ (n = 1752) for men and 1.21‰ (n = 2830) for women from 2005. The prevalence increased during the entire study time in all ages, with the highest prevalence for both genders among those aged 50–69. A total of 7786 individuals started therapy with etanercept or adalimumab during 2005–2009. Annual incidence of new users increased with 23.6% from 2005 to 2009. Sixty one percent of new users redeemed etanercept as the first drug, and 39% redeemed adalimumab. Sixty seven percent of all individuals who received etanercept or adalimumab in 2005 refilled their prescription at least once each of the following 4 years.

Conclusions

Both prevalence and incidence of use of etanercept and adalimumab increased in Norway during 2005–2009. A high proportion of the individuals redeemed prescriptions regularly over 5 years. Copyright © 2010 John Wiley & Sons, Ltd.
Modelle für Graphen – einfach und dennoch eindrucksvoll
Authors: Quadbeck‐Seeger Hans‐Jürgen
Published: December 2010

Am 10. Dezember erhielten Andre Geim und Konstantin Novoselov den Physik‐Nobelpreis 2010 für ihre Arbeiten zum Graphen. Lässt sich diese interessante, monomolekulare Schicht des Graphits auch mit herkömmlichen Molekülbausätzen als Modell nachbilden? Im Prinzip ja, praktisch gibt es jedoch eine triviale Grenze: die unzureichende Zahl an C‐Atomen in der sp2‐Struktur. Mit dem System Moletomics™ tritt dieses Problem erst gar nicht auf. Beliebig große Modellflächen lassen sich einfach und preiswert herstellen.
Schneemuster auf Pflastersteinen
Authors: Schlichting Hans J.
Published: December 2010

Fällt Schnee auf ein Steinpflaster, so zeichnet er die Fugen und Steine nach. Doch während er in einem Fall auf den Steinen schmilzt, bleibt er im anderen Fall auf ihnen liegen. Welcher physikalische Mechanismus sorgt für dieses unterschiedliche Verhalten?
Vom Steigen und Sinken
Authors: Vilgis Thomas
Published: December 2010

Liebhaber von Rohmilch oder nicht homogenisierter Milch beobachten häufig das Aufrahmen: Nach einiger Zeit setzt sich eine schmackhafte Rahmschicht ab, die sich aus größeren Fettpartikeln und Milchproteinen zusammensetzt. Die Aufrahmung lässt sich zwar mit einfachen Mitteln der makroskopischen Physik verstehen, allerdings spielen bei genauerem Hinsehen stochastische Kräfte eine nicht unerhebliche Rolle.
Optische Minimagnetometer
Authors: Knappe Svenja , Preusser Jan , Trahms Lutz , Sander Tilmann
Published: December 2010

Mit einfachen, auf der Brust angebrachten Elektroden lässt sich bekanntlich ein Elektrokardiogramm (EKG) aufzeichnen. Hierbei nutzt man die Tatsache, dass die Ströme im menschlichen Herzmuskel Potentialänderungen auf der Haut verursachen. Gleichzeitig entstehen schwache Magnetfelder, die sich mit supraleitenden Magnetometern (SQUIDs, Superconducting Quantum Interference Devices) messen lassen. Diese müssen allerdings mit flüssigem Helium auf etwa – 269 °C gekühlt werden. Seit einiger Zeit können auch optische Magnetometer Magnetkardiogramme erstellen. Im Gegensatz zu SQUIDs benötigen sie keine aufwändige Kühltechnik.
Die (wirkliche) Dreifachspaltung schwerer Kerne
Authors: von Oertzen Wolfram
Published: December 2010

Schwere radioaktive Kerne zerfallen in zwei Fragmente mittlerer Masse, wie man seit den ersten Experimenten von Otto Hahn und Fritz Straßmann weiß. Dabei werden große Energiemengen frei. Vor etwa 35 Jahren führten jedoch Rechnungen zu der Voraussage, dass auch Spaltungen in drei mittelschwere Fragmente vorkommen müssten – mit noch höherer Energieausbeute, aber auch mit sehr geringer Wahrscheinlichkeit. Kürzlich gelang einer russisch‐deutschen Kollaboration am Flerov Laboratory im JINR in Dubna (Russland) unter Beteiligung des Helmholtz‐Zentrums Berlin (HZB) erstmals der Nachweis dieses seltenen Zerfalls am spontanen Zerfall von Californium‐252 und bei der neutroneninduzierten Spaltung von Uran‐235.
Quantenteilchen unter dem Mikroskop
Authors: Kuhr Stefan
Published: December 2010

Ultrakalte Atome in einem Lichtgitter können sich wie ein Supraleiter oder ein Isolator verhalten. Physikern ist es nun gelungen, diese Vorgänge mit Hilfe eines Mikroskops Atom für Atom, Gitterplatz für Gitterplatz sichtbar zu machen. Dies ist auch für zukünftige Quantencomputer von großer Bedeutung.
Steiler oder flacher? Optimale Wurfwinkel im Sport
Authors: Thaller Sigrid , Mathelitsch Leopold
Published: December 2010

Ist in einer Sportart, sei es Kugelstoßen oder Weitsprung, eine maximale Weite erwünscht, beträgt der Abwurfwinkel im Idealfall 45°. Anfangshöhe und Anfangsgeschwindigkeit, Luftwiderstand, aerodynamische Effekte und physiologische Eigenschaften des Werfers können den idealen Wurfwinkel jedoch erheblich verändern. Geht es um das Erreichen eines bestimmten Ziels, wie zum Beispiel im Basketball, Fußball oder Dart, dann beeinflusst die Treffgenauigkeit den angestrebten Abwurfwinkel. Beim Jonglieren muss auch noch die Zeitdauer eines Wurfes berücksichtigt werden.
Die Anatomie des Ribosoms. Kristallographie mit Synchrotronlicht
Authors: Schlünzen Frank , Harms Jörg M.
Published: December 2010

Ribosomen übersetzen die genetische Information der DNA im Schritt der Proteinbiosynthese in die vielfältigen Proteine, die eine Zelle benötigt. Was dabei genau geschieht und wie die molekulare Struktur dieser riesigen Molekülkomplexe im Detail aussieht, war lange ein Rätsel. Einen wichtigen Beitrag zur Strukturaufklärung leistete die kristallographische Untersuchung mit Sychrotronstrahlung am Forschungszentrum DESY in Hamburg. Von der Kristallzucht bis zur Röntgendiffraktion erforderte dies eine ausgefeilte Experimentiertechnik. Die genaue Kenntnis der molekularen Struktur ermöglicht nun auch eine zielgerichtete Entwicklung neuer Antibiotika. Viele dieser Wirkstoffe blockieren die Proteinbiosynthese im Ribosom.
Effects of scale and data source in periglacial distribution modelling in a high arctic environment, western Svalbard
Authors: Hjort Jan , Etzelmüller Bernd , Tolgensbakk Jon
Published: December 2010

The effects of scale (modelling resolution) and sources of data were explored in relation to periglacial distribution modelling for an area on western Svalbard in the High Arctic. To assess the effects of scale on predictive performance, the distributions of sorted circles and solifluction lobes were modelled at two resolutions (20 × 20 m and 200 × 200 m) using a boosted regression tree, a novel statistical ensemble method. To analyse the effects of sources of data on periglacial distribution modelling, a generalised linear model and a variation partitioning method were used. The explanatory variables were topographic parameters computed from a digital elevation model, vegetation and soil moisture indices derived from a Landsat TM 5 scene, and field survey‐based information on surficial materials. Firstly, similar levels of success were achieved in predicting the periglacial feature distributions at the local (20 m) and landscape (200 m) scales. Secondly, results indicated the potential for modelling to replace labour‐intensive field observations. The importance of topographic parameters for predicting the distribution of periglacial features in the sparsely vegetated High Arctic environment was also evident. Methodologically, novel statistical techniques and earth observation data provided an efficient combination for analysing periglacial landforms and processes in this remote region. Copyright © 2010 John Wiley & Sons, Ltd.
Higher Tobramycin concentration and vibrating mesh technology can shorten antibiotic treatment time in cystic fibrosis
Authors: Coates Allan L. , Denk Oliver , Leung Kitty , Ribeiro Nancy , Chan Jeffrey , Green Maria , Martin Sean , Charron Martin , Edwardes Michael , Keller Manfred
Published: December 2010

Poor adherence to recommended therapy in cystic fibrosis (CF) is often because of the time demands of therapy. Tobramycin (TOBI®, 300 mg at 60 mg/ml) inhaled from the PARI LC PLUS® nebulizer requires about 20 min. This study determined if equivalent levels of pulmonary deposition could be achieved in shorter time using 1.5 ml of 100 mg/ml tobramycin solution delivered by an investigational eFlow® nebulizer. Sixteen males with stable CF, 8 children and 8 adults, and an FEV1 > 45% predicted inhaled both preparations on two occasions with 99mTc‐DTPA added to the tobramycin. Blood samples were taken for quantification of tobramycin in the serum. The PARI LC PLUS® delivered 45.4 (39.3–51.6), mean and 95% CI, mg to the lungs in 17.0 ± 2.5 min (mean ± SD) with serum levels of 1,089 ± 388 µg/L. The investigational eFlow® delivered 46.3(40.3–51.7) mg in 4.0 ± 1.0 min with blood levels of 909 ± 458 µg/L. Only the time of delivery was significantly different with P < 0.0001 (paired t‐test). Tolerability of the treatment was comparable for both inhalation regimes, but the shorter treatment was preferred by all patients. These results demonstrate the possibility of delivering equivalent levels of tobramycin much faster into the lungs of CF patients when using eFlow®, a very efficient electronic nebulizer. Pediatr Pulmonol. 2011; 46:401–408. © 2010 Wiley‐Liss, Inc.
Efficacy of metered‐dose inhalers for children with acute asthma exacerbations
Authors: Goh Anne Eng Neo , Tang Jenny Poh Lin , Ling Ho , Hoe Teoh Oon , Chong Ng Kee , Moh Chay Oh , Huak Chan Yiong
Published: December 2010

Objective

To compare the effectiveness of the administration of inhaled beta‐agonists delivered via a metered‐dose inhaler (MDI) with spacers—as part of an evidence‐based asthma pathway developed to manage acute asthma exacerbations in children at the emergency room level and in inpatient management—against administration via nebulization.

Design

Case with historical control.

Setting

KK Women's and Children's Hospital (Singapore).

Participants

A total of 19,951 children (infants to older children) aged 18 years and younger who attended the emergency room for asthma exacerbations.

Main Outcome Measures

Average length of stay, proportion admitted to high dependency or intensive care, proportion readmitted for unresolved symptoms within 72 hr, cost per patient and overall.

Results

There was no increase in the mean proportion of emergency room attendances admitted to inpatient care with use of an MDI (mean difference 0.97%, 95% CI: −1.6–3.5%, P = 0.447), nor of children admitted to intensive care (0.21 vs. 0.20 pre‐ and post‐pathway, P = 0.827) or to high dependency units (2.21 vs. 1.37 pre‐ and post‐pathway, P = 0.200) but a significant reduction in the within 72 hr re‐attendance rate (mean difference 1.4%, 95% CI: 0.78–2.0%, P < 0.001) with use of an MDI. The average length and cost per patient for an inpatient stay for acute asthma exacerbations was reduced with use of an MDI.

Conclusions

The use of an MDI with spacer as part of an evidence‐based asthma pathway was effective in the management of acute asthma exacerbations in the emergency room setting and for inpatient management. Pediatr. Pulmonol. 2011; 46:421–427. © 2010 Wiley‐Liss, Inc.
Relation between partial and raised volume forced expiratory flows in sick infants
Authors: Bar‐Yishay Ephraim , Springer Chaim , Hevroni Avigdor , Godfrey Simon
Published: December 2010

Rationale

The maximal expiratory flow–volume (MEFV) and the partial expiratory flow–volume (PEFV) maneuvers are interchangeably performed when testing infant lung function. In recent years, the MEFV has gained popularity over the PEFV as it offers the investigator various forced expiratory flow and volume variables in addition to the sole, maximal flow at functional residual capacity (${\dot {\rm {V}}}{\max} {\rm FRC}$) available from the PEFV maneuver. Both types of measure are considered to provide information on airway function.

Objectives

To compare ${\dot {\rm {V}}}{\max} {\rm FRC}$ values by PEFV to flows at low lung volumes by MEFV in infants suffering from a variety of illnesses.

Methods

Retrospective analysis of records of 175 infants attending a tertiary out‐patient clinic (age range 2–234 weeks). Comparisons between parameters derived from the PEFV and MEFV curves were made by linear regression and by Bland–Altman plots.

Measurements and Main Results

${\dot {\rm {V}}}{\max} {\rm FRC}$ highly correlated with forced expiratory flows at 85% of forced vital capacity (FEF85; r = 0.87, P < 0.0001) with a mean bias of 20 ml/sec, and at 75% (FEF75; r = 0.83, P < 0.0001) with a greater mean bias of −72 ml/sec, but less with forced expired volume in 0.5 sec (FEV0.5; r = 0.66, P < 0.0001) showing a much wider scatter especially in infants with more severe obstruction. Same agreement between ${\dot {\rm {V}}}{\max} {\rm FRC}$ and FEF85 or FEF75 was seen when presented as z‐scores (r = 0.77 and 0.76; respectively).

Conclusions

Regardless of the maneuver performed, PEFV or MEFV, ${\dot {\rm {V}}}{\max} {\rm FRC}$ and FEF85, and FEF75 show high agreement in sick infants. As they both describe small airways function, both maneuvers may be interchangeable. Pediatr. Pulmonol. 2011; 46:458–463. © 2010 Wiley‐Liss, Inc.
Modifiable lifestyle factors impact airway health in non‐asthmatic prepubescent boys but not girls
Authors: Rosenkranz Sara K. , Swain Katherine E. , Rosenkranz Richard R. , Beckman Bethany , Harms Craig A.
Published: December 2010

Introduction

The prevalence of both childhood obesity and childhood asthma has increased dramatically over the past few decades. Little is known concerning the role of body composition and lifestyle influences on airway health in children.

Purpose

To determine whether body composition, fruit and vegetable intake (FV) and physical activity (PA) impact airway health in healthy prepubescent children.

Methods

Pulmonary function tests (forced expiratory flow in 1‐sec, forced vital capacity, forced expiratory flow at 25–75% of vital capacity) and exhaled nitric oxide (eNO) were measured pre‐ and post‐exercise in 40 healthy (20 boys, 20 girls), non‐asthmatic prepubescent children (age 9.7 ± 0.8 years). PA and FV intake were assessed via questionnaire. Each participant completed an incremental cycle‐ergometer exercise test to exhaustion (V02max). Body composition was measured via Dual Energy X‐ray Absorptiometry. Participants were stratified by sex for analyses, and follow‐up analyses were performed using a clinically significant drop in FEV1 of ≥10% to divide participants into groups.

Results

In the overall group, the change in FEV1 (pre‐ and post‐exercise) was inversely related (r = −0.47, P < 0.05) to % body fat; participants with the highest body fat demonstrated the greatest decrease in FEV1 (i.e., airway narrowing). When participants were divided by sex, this association held true only for boys (r = −0.61, P < 0.01). Percent body fat was the only significant contributor to the overall prediction of ▵FEV1 in boys. Boys engaged in significantly more PA than girls (3.45 ± 2.39; 2.00 ± 1.30 activities/day). Boys also had significantly higher V02max adjusted for lean body mass than girls (48.06 ± 5.09; 42.30 ± 6.06). Body fat percent was not different by sex (P > 0.05). The participants in the ≥10% FEV1 group had a significantly greater body fat (28.1 ± 9.6%) compared to the <10% drop group (18.8 ± 9.8%).

Conclusion

These results suggest that PA, FV consumption, and body fat collectively impact airway health in prepubescent boys but not girls. Body fat, however, is the only independent predictor of post‐exercise airway narrowing. Pediatr. Pulmonol. 2011; 46:464–472. © 2010 Wiley‐Liss, Inc.
Age of Pseudomonas aeruginosa acquisition and subsequent severity of cystic fibrosis lung disease
Authors: Pittman Jessica E. , Calloway Elizabeth H. , Kiser Michelle , Yeatts John , Davis Stephanie D. , Drumm Mitchell L. , Schechter Michael S. , Leigh Margaret W. , Emond Mary , Van Rie Annelies , Knowles Michael R.
Published: December 2010

Rationale

Pseudomonas aeruginosa (Pa) is associated with poor pulmonary outcomes in cystic fibrosis (CF), but the association between age of Pa infection and severity of subsequent lung disease has not been thoroughly investigated.

Objective

Our goal was to determine the association between age of Pa acquisition and subsequent severity of CF lung disease.

Methods

Case–control study using CF Foundation Registry data of 629 ΔF508 homozygotes with severe and mild lung disease (FEV1 in the lowest and highest quartile of birth cohort, respectively). Multivariate logistic regression was performed to determine the association between age of Pa acquisition and lung disease severity.

Results

Earlier age of Pa infection was strongly associated with increased odds of severe lung disease. For first and persistent Pa, adjusted odds ratios for severe lung disease were 6.5 (95% CI 3.1, 13.7; P < 0.0001) and 11.2 (5.4, 23.1; P < 0.0001), respectively, for subjects with infection before age 5 versus at ≥10 years; the association was stronger in females than males.

Conclusions

Earlier Pa infection, particularly before 5 years of age, is strongly associated with severe CF lung disease later in life. This study is not designed to determine causality; Pa infection may be causing lung injury, or may be a marker of ongoing inflammation and lung damage in young children with CF. Pediatr. Pulmonol. 2011; 46:497–504. © 2010 Wiley‐Liss, Inc.
Low birth weight and respiratory hospitalizations in adolescence
Authors: Walter Eric C. , Koepsell Thomas D. , Chien Jason W.
Published: December 2010

Objective

Some low birth weight survivors are at increased risk of respiratory disease. We studied whether low birth weight was associated with hospitalization for respiratory illness in adolescence and to what degree bronchopulmonary dysplasia, cerebral palsy, and other comorbidities accounted for this association.

Methods

We performed a population‐based retrospective cohort study using Washington State birth certificates from 1987 to 1994 to identify exposed (low birth weight) and unexposed (normal birth weight) subjects. Normal birth weight subjects were randomly selected from birth certificates, frequency matched to low birth weight subjects by birth year. Deaths prior to age 12 were excluded. The primary exposure was low birth weight: subcategorized as moderately‐low‐birth weight (1,500–2,499 g) and very‐low‐birth weight (<1,500 g). The primary outcome was the first respiratory related hospitalization between the ages of 12–20. Respiratory hospitalizations were defined by ICD‐9 discharge diagnosis codes.

Results

After adjustment, the hazard ratio for hospitalization was 1.39 for moderately‐low‐birth weight (95% CI 1.17–1.65, P < 0.001) and 2.52 for very‐low‐birth weight (1.80–3.53, P < 0.001). Controlling for bronchopulmonary dysplasia attenuated the risk for very‐low‐birth weight to 1.76 (1.17–2.64; P = 0.006). A similar attenuation was seen after controlling for cerebral palsy [HR 1.49 (1.02–2.18), P = 0.04], suggesting that some of the risk is mediated through these diagnoses. Among moderately‐low‐birth weight survivors, controlling for these diagnoses had less of an effect.

Conclusions

Low birth weight was associated with an increased risk of respiratory hospitalizations in adolescence. Comorbidities explained some of this risk. However, low birth weight remained independently associated with an increased risk of hospitalization. Pediatr. Pulmonol. 2011; 46:473–482. © 2010 Wiley‐Liss, Inc.
Life‐threatening anaphylactic reaction after the administration of airway topical lidocaine
Authors: Soong Wen‐Jue , Lee Yu‐Sheng , Soong Yen‐Hui , Tsao Pei‐Chen , Yang Chia‐Feng , Jeng Mei‐Ji , Peng Yu‐Yun
Published: December 2010

A 9‐year‐old boy who developed a life‐threatening anaphylaxis reaction of the airway and subsequent dyspnea and circulation collapse because of instilled the topical lidocaine into the airway within 2 min before performing flexible bronchoscopy (FB). FB revealed swollen airway mucosa and extensive foamy secretion that severely compromised the ventilation lumen. Rapid detection with FB and immediate resuscitation, including prompt administration of epinephrine, volume expander, and positive pressure ventilation with pure oxygen via an endotracheal tube, were successfully save the patient's life. Pediatr. Pulmonol. 2011; 46:505–508. © 2010 Wiley‐Liss, Inc.
Neuromuscular electrical stimulation is no more effective than usual care for the treatment of primary dysphagia in children
Authors: Christiaanse Mary E. , Mabe Betty , Russell Greg , Simeone Tanya Long , Fortunato John , Rubin Bruce
Published: December 2010

Objective

Dysphagia can lead to chronic aspiration and pulmonary disease. The objective of this study was to compare change in swallowing function in pediatric patients with dysphagia who received neuromuscular electrical stimulation (NMES) to a control group who received usual oral motor training and dietary manipulations without NMES.

Study design

Retrospective analysis of change in Functional Oral Intake Scale (FOIS) level derived from videofluoscopic swallowing studies performed before and after NMES (treatment group: N = 46) compared to control group (control group: N = 47). Children were classified into two groups based on the etiology of their dysphagia (primary vs. acquired). NMES took place in a tertiary medical center for an average of 22 treatment sessions over 10 weeks. An independent t‐test was used to test for differences in the change in FOIS level between groups. An analysis of covariance was run within groups to assess the relationship between diagnosis and change in FOIS level.

Results

Both groups improved in their FOIS level (P < 0.01) but the amount of change was not different (P = 0.11). Only the treatment group who had acquired dysphagia improved more than the similar subgroup of control children (P = 0.007).

Conclusion

NMES treatment of anterior neck muscles in a heterogeneous group of pediatric patients with dysphagia did not improve the swallow function more than that seen in patients who did not receive NMES treatment. However, there may be subgroups of children that will improve with NMES treatment. Pediatr. Pulmonol. 2011; 46:559–565. © 2010 Wiley‐Liss, Inc.
Exercise parameters in the management of breast cancer: A systematic review of randomized controlled trials
Authors: Pastakia Khushnum , Kumar Saravana
Published: December 2010

Aim. Previous systematic reviews have examined the efficacy of exercise in improving the quality of life for patients with, and survivors of, breast cancer. This review sets out to determine the parameters of exercise programmes used in randomized controlled trials. Methods. A systematic review of randomized controlled trials was conducted. Only trials that reported significant improvement on the quality of life outcome were included. Data relating to the parameters of exercise (mode, duration, frequency and intensity and delivery method) were analyzed. Results. Nine randomized controlled trials were included in this review. Overall quality of the trials was average. Aerobic exercise was featured in eight of the nine trials and was used in combination with resistance training in four trials. All the trials were gym‐based, were under the supervision of a physiotherapist and included a warm‐up and cool‐down phase. Conclusions. This review concludes that aerobic exercise performed with or without weight training is a common feature of exercise programmes that report significant quality of life–related outcomes. The most commonly reported exercise parameters were three sessions per week, at moderate intensity being equivalent to 50% to 80% of the maximum heart rate for greater than 30 minutes. Copyright © 2010 John Wiley & Sons, Ltd.
Signs and symptoms of temporomandibular disorders and their impact on psychosocial status in non‐patient university student's population
Authors: Rodrigues Jeniffer Holley , Biasotto‐Gonzalez Daniela Aparecida , Bussadori Sandra Kalil , Mesquita‐Ferrari Raquel Agnelli , Fernandes Kristianne Porta Santos , Tenis Carlos Alberto , Martins Manoela Domingues
Published: December 2010

Background and Purpose. Temporomandibular disorders (TMD) exhibit a combination of signs and symptoms, mainly characterized by pain and dysfunction, which impairs the functional capacity of the mastication system. These symptoms may produce a negative impact on social activities, employment and leisure. The aim of this study was to early identify the signs and symptoms of TMD and their impact on daily life of non‐patient university students. Methods. Data were collected from 183 students of the dentistry course. The Axis II of the Research Diagnostic Criteria for Temporomandibular Disorders was administered and analyzed using Spearman test at a significance level of 0.05. Results. Among the 183 participants, 107 were women (58.47%) and 76 were men (41.53%). Age ranged from 18 to 47, with a mean age of 25.35 years. In relation to pain intensity and disability, 129 participants (70.88%) reported no pain in the previous 6 months. An analysis of depression revealed that 35 (19.67%) had moderate and 7 (3.83%) had severe depression. The assessment of nonspecific physical symptoms including pain revealed that nine (4.92%) exhibited moderate symptoms, and one (0.55%) exhibited severe symptoms. The nonspecific physical symptoms excluding items of pain analysis revealed that 44 (24.04%) exhibited moderate symptoms, and 91 (49.73%) exhibited severe. The functions reported as most adversely affected by jaw disability were yawning, eating hard foods, chewing, smiling and laughing. Regarding the habit, 64 (35%) confirmed having the nighttime and 59 daytime (32.3%) teeth grinding with a significant correlation with the four domains analyzed. A significant correlation was observed among all domains. Conclusion. This study analyzed a young population that exhibited para‐functional habits and nonspecific physical symptoms excluding pain that need some intervention since they could progress to a symptomatic TMD in future. Copyright © 2010 John Wiley & Sons, Ltd.
A new adaptive CUSUM control chart for detecting the multivariate process mean
Authors: Dai Yi , Luo Yunzhao , Li Zhonghua , Wang Zhaojun
Published: December 2010

We propose a new multivariate CUSUM control chart, which is based on self adaption of its reference value according to the information from current process readings, to quickly detect the multivariate process mean shifts. By specifying the minimum magnitude of the process mean shift in terms of its non‐centrality parameter, our proposed control chart can achieve an overall performance for detecting a particular range of shifts. This adaptive feature of our method is based on two EWMA operators to estimate the current process mean level and make the detection at each step be approximately optimal. Moreover, we compare our chart with the conventional multivariate CUSUM chart. The advantages of our control chart detection for range shifts over the existing charts are greatly improved. The Markovian chain method, through which the average run length can be computed, is also presented. Copyright © 2010 John Wiley & Sons, Ltd.
Generalized nonlinear ℋ︁∞synthesis condition with its numerically efficient solution
Authors: Zheng Qian , Wu Fen
Published: December 2010

In this paper, we will first derive a general synthesis condition for the output‐feedbackℋ︁∞control of smooth nonlinear systems. Computationally efficient ℋ︁∞control design procedure for a subclass of smooth nonlinear systems with polynomial vector field is then proposed by converting the resulting Hamilton‐Jacobi‐Isaacs inequalities from rational forms to their equivalent polynomial forms. Using quadratic Lyapunov functions, both the state‐feedback and output‐feedback problems will be reformulated as semi‐definite optimization conditions and locally tractable solutions can be obtained through sum‐of‐squares (SOS) programming. The proposed nonlinear ℋ︁∞design approach achieves significant relaxations on the plant structure compared with existing results in the literature. Moreover, the SOS‐based solution algorithm provides an effective computational scheme to break the bottleneck in solving nonlinear ℋ︁∞and optimal control problems. The proposed nonlinear ℋ︁∞control approach has been applied to several examples to demonstrate its advantages over existing nonlinear control techniques and its usefulness to engineering problems. Copyright © 2010 John Wiley & Sons, Ltd.
Tribological evaluation of HVOF thermal‐spray coatings as a hard chrome replacement
Authors: Picas Josep A. , Punset Miquel , Teresa Baile M. , Martín Enric , Forn Antonio
Published: December 2010

Hard chrome plating has been used in several different applications in industries that require abrasive sliding wear resistance, such as hydraulic pistons, shafts or bearings. However, the increasing environmental and worker safety pressures on electrolytic hard chrome are leading companies to adopt alternatives. The improvements of the high‐velocity‐oxy‐fuel (HVOF) thermal spray process allow the chromium coating replacement with a comparable or superior surface treatment and are more environmentally friendly. This HVOF process, as a flexible dry‐coating technology, avoids high‐volume waste streams and enables a flexible choice of coating material for each application. The cobalt–chromium‐cemented tungsten carbides are some of the easiest materials to spray and the WC‐10Co‐4Cr coatings have demonstrated superior performance over hard chrome with regard to mechanical and tribological properties. In this work, this coating has been deposited with a Sulzer Metco WokaJet‐400 kerosene fuel spray gun, and the spray conditions have been optimized in order to ensure the best properties of the coatings. The mechanical and tribological properties have been evaluated in coatings sprayed with four deposition conditions that involve different gas flow rates. The most wear‐resistant coating is obtained with those HVOF parameters that prevent decarburization of WC particles and, at the same time, allow an adequate agglomerate melting giving a good intersplat adhesion. The results indicate that HVOF‐sprayed WC‐CoCr coatings are a reliable alternative to electrolytic hard chrome (EHC) in the aeronautical industry to coat landing gear components. In particular, in the dry wear tests, the WC‐CoCr coatings outperform hard chrome coatings in wear resistance. Copyright © 2010 John Wiley & Sons, Ltd.
Modified robust variance estimator for generalized estimating equations with improved small‐sample performance
Authors: Wang Ming , Long Qi
Published: December 2010

Generalized estimating equations (GEE (Biometrika 1986; 73(1):13–22) is a general statistical method to fit marginal models for correlated or clustered responses, and it uses a robust sandwich estimator to estimate the variance–covariance matrix of the regression coefficient estimates. While this sandwich estimator is robust to the misspecification of the correlation structure of the responses, its finite sample performance deteriorates as the number of clusters or observations per cluster decreases. To address this limitation, Pan (Biometrika 2001; 88(3):901–906) and Mancl and DeRouen (Biometrics 2001; 57(1):126–134) investigated two modifications to the original sandwich variance estimator. Motivated by the ideas underlying these two modifications, we propose a novel robust variance estimator that combines the strengths of these estimators. Our theoretical and numerical results show that the proposed estimator attains better efficiency and achieves better finite sample performance compared with existing estimators. In particular, when the sample size or cluster size is small, our proposed estimator exhibits lower bias and the resulting confidence intervals for GEE estimates achieve better coverage rates performance. We illustrate the proposed method using data from a dental study. Copyright © 2010 John Wiley & Sons, Ltd.
Impacts of contextual and explicit instruction on preservice elementary teachers' understandings of the nature of science
Authors: Bell Randy L. , Matkins Juanita Jo , Gansneder Bruce M.
Published: December 2010

This mixed‐methods investigation compared the relative impacts of instructional approach and context of nature of science instruction on preservice elementary teachers' understandings. The sample consisted of 75 preservice teachers enrolled in four sections of an elementary science methods course. Independent variables included instructional approach to teaching nature of science (implicit vs. explicit) and the context of nature of science instruction (as a stand‐alone topic vs. situated within instruction about global climate change and global warming). These treatments were randomly applied to the four class sections along a 2 × 2 matrix, permitting the comparison of outcomes for each independent variable separately and in combination to those of a control group. Data collection spanned the semester‐long course and included written responses to pre‐ and post‐treatment administrations of the VNOS‐B, semi‐structured interviews, and a variety of classroom artifacts. Qualitative methods were used to analyze the data with the goal of constructing profiles of participants' understandings of the nature of science and of global climate change /global warming (GCC/GW). These profiles were compared across treatments using non‐parametric statistics to assess the relative effectiveness of the four instructional approaches. Results indicated that preservice teachers who experienced explicit instruction about the nature of science made statistically significant gains in their views of nature of science regardless of whether the nature of science instruction was situated within the context of GCC/GW or as a stand‐alone topic. Further, the participants who experienced explicit nature of science instruction as a stand‐alone topic were able to apply their understandings of nature of science appropriately to novel situations and issues. We address the implications of these results for teaching the nature of science in teacher preparation courses. © 2010 Wiley Periodicals, Inc., Inc. J Res Sci Teach 48: 414–436, 2011
A typology of undergraduate students' conceptions of size and scale: Identifying and characterizing conceptual variation
Authors: Swarat Su , Light Greg , Park Eun Jung , Drane Denise
Published: December 2010

The importance of “size and scale” in nanoscience and engineering has been recognized by both scientists and science educators. A solid understanding of this concept is key to the learning of nanoscience. Students, however, have been reported to have considerable difficulty grasping this concept; yet little is known regarding their state of understanding. To address this knowledge gap, we conducted a series of studies that were aimed at exploring the different ways students conceive of “size and scale” in the context of undergraduate nanoscience and engineering courses. Informed by Variation Theory of Learning (Marton and Booth, 1997), we identified four major categories (with two sub‐categories within each) of student conception—fragmented, linear, proportional, and logarithmic. These conception categories, together with the aspects of variation that characterize and distinguish them, are summarized in a typology. In addition to serving as a diagnostic tool to describe students' understanding, this typology can also be used to guide the development of instructional interventions that facilitate students to move toward a more sophisticated understanding of “size and scale.” © 2011 Wiley Periodicals, Inc., Inc. J Res Sci Teach 48: 512–533, 2011