bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of the small low‐pass filter by utilizing the slotted‐ground‐plane resonator
Authors: Wang Chien‐Jen , Wang Wan‐Ti
Published: March 2013

In this article, a new design for the compact low‐pass filter (LPF) with a wide rejection band is presented by utilizing the slotted‐ground‐plane (SGP) structure. A modified‐π slot is etched in the ground plane to excite three different resonant modes. A wide rectangular stub, which overlaps the connection slots, connects to the microstrip transmission line. This technique significantly enhances the rejection characteristics. A reversed‐C slot is embedded inside the modified‐π slot to lower the initial resonant frequency of the LPF. In particular, two shorted quarter‐wavelength branch slots are used to generate two transmission zeros such that the high‐frequency rejection performance can improve. An equivalent resistor, inductor, capacitor (RLC) circuit is proposed to model the introduced LPF and corresponding RLC parameters are extracted. A fabricated filter rejects the signals at the frequencies from 1.97 to 12.0 GHz with more that −20‐dB suppression. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1287–1291, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27595
The Movement and Exchange of Dogs in the Prehistoric Caribbean: An Isotopic Investigation
Authors: Laffoon J. E. , Plomp E. , Davies G. R. , Hoogland M. L. P. , Hofman C. L.
Published: March 2013

This study explores the feasibility of using strontium isotope (87Sr/86Sr) analyses of enamel from domestic dogs (Canis familiaris) to investigate networks of exchange in the prehistoric Circum‐Caribbean. Dog teeth were obtained from burial and domestic contexts from two prehistoric sites (Anse à la Gourde and Morel) on Grande‐Terre, Guadeloupe (Lesser Antilles). Strontium isotope results were compared with local biosphere 87Sr/86Sr data at the scale of the site, island and archipelago. The isotope results indicate both local and nonlocal origins with three dogs (30%) identified as nonlocal (one from Anse à la Gourde and two from Morel). The variance in 87Sr/86Sr ratios of the nonlocal dog teeth is consistent with diverse multiple origins external to the island of Grande‐Terre but consistent with origins from other islands of the Lesser Antilles. The diverse origins of the nonlocal dog samples indicate that the prehistoric circulation of dogs occurred at multiple scales from regional to long distance. Significantly, the 87Sr/86Sr ratios of some of the dog teeth are comparable with values of nonlocal humans at Anse à la Gourde determined in previous studies. It is possible that these comparable 87Sr/86Sr ratios result from similar natal origins, for example if individuals were migrating to Guadeloupe with dogs. The results of this study contribute to an ongoing regional investigation of the economic, social and political roles of animals and animal remains and the multiscalar networks of prehistoric mobility and exchange in the Circum‐Caribbean region. Copyright © 2013 John Wiley & Sons, Ltd.
Preoperative lifestyle intervention in bariatric surgery: Initial results from a randomized, controlled trial
Authors: Kalarchian M. A. , Marcus M. D. , Courcoulas A. P. , Cheng Y. , Levine M. D.
Published: March 2013

Objective:

To document preoperative outcomes of a behavioral lifestyle intervention delivered to patients prior to bariatric surgery in comparison to treatment as usual (insurance‐mandated physician supervised diet).

Design and Methods:

After completing a baseline assessment, candidates for surgery were randomized to a 6‐month, evidence‐informed, manualized lifestyle intervention (LIFESTYLE, n = 121) or to preoperative care as usual (USUAL CARE, n = 119). At 6 months, 187 participants remained candidates for bariatric surgery and were included in the analyses.

Results:

LIFESTYLE participants lost significantly more weight than those receiving USUAL CARE [8.3 ± 7.8 kg vs. 3.3 ± 5.5 kg, F(1,183) = 23.6, P < 0.0001], with an effect size of 0.72. Additionally, logistic regression modeling indicated that LIFESTYLE patients were significantly more likely to lose at least 5% of initial body weight than those in USUAL CARE [OR (95% CI) = 2.94 (1.253, 6.903)], as were participants who were heavier [OR (95% CI) = 1.07 (1.001‐1.14) for each unit increase in BMI] or with larger improvements in eating behaviors [OR (95% CI) = 1.1 (1.049, 1.145) for each unit increase on the Eating Behavior Inventory).

Conclusions:

A behavioral lifestyle intervention for severely overweight individuals leads to clinically significant weight loss prior to bariatric surgery. Post‐surgery follow‐up will allow us to examine the impact of the preoperative intervention on postoperative outcomes.
Erosion and reworking of Pacific sediments near the Eocene‐Oligocene boundary
Authors: Moore Ted C.
Published: March 2013

The Eocene‐Oligocene (E/O) boundary interval marks one of the largest and most rapid changes in climate during the last 50 Myr. Because of a very shallow calcium carbonate compensation depth in the Eocene, as well as the reworking of sediments and hiatuses in the boundary zone, it has also been one of the most difficult stratigraphic boundaries to study in deep water marine sections, especially in the Pacific Ocean. Recently, three drill sites have recovered complete sections of the E/O boundary interval in the tropical Pacific. A detailed study of these sections shows a series of pulses of reworked older radiolarians in the upper Eocene and lowermost Oligocene. The two largest pulses are coincident with the two sharp steps in carbon and oxygen isotope values that bracket the E/O boundary. Several smaller peaks in reworked material precede these two maxima. It is proposed that immixing of the older radiolarian species results from erosion and redeposition, possibly linked to pulses of new bottom water formation and the formation of a deep pycnocline.
Thermal characteristics of ethylene‐co‐vinyl acetate/cellulose microfibers composites
Authors: Sonia A. , Dasan K. Priya , Jayachandran Jeenet
Published: March 2013

Cellulose microfibers were obtained from Hibiscus sabadariffa by steam explosion technique. Structural and surface analysis of the microfibers showed a reduction in diameter and changes in surface morphology from that of raw fibers. The chemical composition of fibers showed increase in α‐cellulose content and decrease in lignin and hemicelluloses for the microfibers. These factors were further confirmed by XRD, SEM, and FTIR results. The CMF were introduced to EVA at different loading by melt extrusion. The composites were analyzed for their thermal stability and phase transition using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). TGA analysis of the composites showed increased onset temperatures for composites compared with pure EVA indicating the superior thermal stability of the composites with fiber loading. DSC analysis shows increase in melting enthalpy and percentage crystallinity with fiber loading increases. Kinetic parameter for the degradation of the composites was obtained using Broido, Coats–Redfern, and Horowitz‐Metzger methods. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers
Effect of organoclay content on the mechanical properties of ethylene‐vinyl acetate copolymer/ multi‐walled carbon nanotube/organoclay foams
Authors: Seol Sung‐Mok , Kim Gue‐Hyun
Published: March 2013

The main objective of this study is to obtain ethylene‐vinyl acetate copolymer (EVA)/multi‐walled carbon nanotube (MWCNT)/organoclay foams with improved mechanical properties without increase of their density, compared with EVA/MWCNT foams. MWCNT content was fixed at 5 phr in this study. To achieve the objective, EVA was melt‐mixed with MWCNTs and organoclays in a bench kneader. And the obtained EVA/MWCNT/organoclay mixtures were mixed with chemical blowing agent and cross‐linking agent in a two roll‐mill. After being mixed in a two roll‐mill, the mixtures were put in a mold and the foams were obtained by compression‐molding. The effect of organoclay content on the mechanical properties and surface resistivity of EVA/MWCNT (5 phr)/organoclay foams was investigated. The addition of 1 phr organoclays to the EVA/MWCNT (5 phr) foams resulted in the improvement of tensile strength, 100% tensile modulus, tear strength, and compression set without increase of the density. However, further increase in content of organoclay (3 phr) leaded to a deterioration of mechanical properties. Therefore, determining the optimal content of organoclay was very important in order to achieve the main objective of this study. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers
Preparation, characterization, and mechanical properties of poly(ε‐caprolactone)/polylactic acid blend composites
Authors: Akos Noel Ibrahim , Wahit Mat Uzir , Mohamed Rahmah , Yussuf Abdirahman Ali
Published: March 2013

Mechanical properties of poly(ε‐caprolactone) (PCL) and polylactic acid (PLA) blend reinforced with Dura and Tenera palm press fibers were studied. Dicumyl peroxide (DCP) was used as compatibilizer in the blend composites. Fourier transforms infrared spectrophotometer (FTIR) and field emission scanning electron microscope (FESEM) was used to study the effect of treatment on the fibers and fiber/matrix adhesion respectively. The uncompatibilized blend composites exhibited higher Young's modulus than the compatibilized blend composites. Impact strength of compatibilized blend composites of Tenera fibers (FM) increased by 161% at 10 wt% fiber load more than the uncompatibilized blend composites at same fiber load. The Dura fibers (FN) enhanced impact strength by 133% at 10 wt% fiber load. Tensile strength increased by 40% for compatibilized FM blend composites. In conclusion, it was observed that DCP incorporation resulted in good interfacial adhesion as revealed by the FESEM micrographs and evidenced in the improved mechanical properties. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers
Extruder‐made TPO nanocomposites. II. Effect of maleated poly(propylene)/organoclay ratio on morphology and thermal expansion behavior
Authors: Tiwari Rajkiran R. , Hunter Douglas L. , Paul Donald R.
Published: March 2013

Coefficients of linear thermal expansion (CTE) for poly(propylene)/ poly(propylene)‐grafted‐maleic anhydride/montmorillonite ethylene‐co‐octene elastomer (PP/PP‐g‐MA/MMT/EOR) blend nanocomposites were determined as a function of MMT content and various PP‐g‐MA/organoclay masterbatch ratios. The nanocomposites were prepared in a twin‐screw extruder at a fixed 30 wt % elastomer, 0–7 wt % MMT content, and various PP‐g‐MA/organoclay ratio of 0, 0.5, 1.0, and 1.5. The organoclay dispersion facilitated by the maleated PP helps to reduce the size of the dispersed phase elastomer particles in the PP matrix. The elastomer particle size decreased significantly as the PP‐g‐MA/organoclay ratio and MMT content increased; the elastomer particles viewed // to flow direction (FD) are smaller and less deformed compared to those viewed // to transverse direction (TD). The elastomer particle shape based on the view along the three orthogonal directions of the injection molded sample is similar to a prolate ellipsoid. The CTE decreased significantly in the FD and TD, whereas a slight increase is observed in the normal direction in the presence of MMT and PP‐g‐MA. The Chow model based on a two population approach showed better fit to experimental CTE when the effect of MMT and elastomer are considered individually. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B Polym. Phys. 2013, 51, 952–965
Existential behavioural therapy for informal caregivers of palliative patients: a randomised controlled trial
Authors: Fegg M. J. , Brandstätter M. , Kögler M. , Hauke G. , Rechenberg‐Winter P. , Fensterer V. , Küchenhoff H. , Hentrich M. , Belka C. , Borasio G. D.
Published: March 2013

Background

Existential behavioural therapy (EBT) was developed to support informal caregivers of palliative patients in the last stage of life and during bereavement as a manualised group psychotherapy comprising six sessions. We tested the effectiveness of EBT on mental stress and quality of life (QOL).

Methods

Informal caregivers were randomly assigned (1:1) to EBT or a treatment‐as‐usual control group using computer‐generated numbers in blocks of 10. Primary outcomes were assessed with the Brief Symptom Inventory (subscales somatisation, anxiety and depression), the Satisfaction with Life Scale (SWLS), the WHOQOL‐BREF and a numeric rating scale for QOL (QOL‐NRS, range 0–10). Data were collected at baseline, pre‐treatment, post‐treatment and follow‐ups after 3 and 12 months. Treatment effects were assessed with a multivariate analysis of covariance.

Results

Out of 160 relatives, 81 were assigned to EBT and 79 to the control group. Participants were 54.5 ± 13.2 years old; 69.9% were female. The multivariate model was significant for the pre‐/post‐comparison (p = 0.005) and the pre‐/12‐month comparison (p = 0.05) but not for the pre‐/3‐month comparison. Medium to large effects on anxiety and QOL (SWLS, WHOQOL‐BREF, QOL‐NRS) were found at post‐treatment; medium effects on depression and QOL (QOL‐NRS) emerged in the 12‐month follow‐up. No adverse effects of the intervention were observed.

Conclusion

Existential behavioural therapy appears to exert beneficial effects on distress and QOL of informal caregivers of palliative patients. Further longitudinal evidence is needed to confirm these findings. Copyright © 2013 John Wiley & Sons, Ltd.
Clostridium perfringens epsilon toxin H149A mutant as a platform for receptor binding studies
Authors: Bokori‐Brown Monika , Kokkinidou Maria C. , Savva Christos G. , Fernandes da Costa Sérgio , Naylor Claire E. , Cole Ambrose R. , Moss David S. , Basak Ajit K. , Titball Richard W.
Published: March 2013

Clostridium perfringens epsilon toxin (Etx) is a pore‐forming toxin responsible for a severe and rapidly fatal enterotoxemia of ruminants. The toxin is classified as a category B bioterrorism agent by the U.S. Government Centres for Disease Control and Prevention (CDC), making work with recombinant toxin difficult. To reduce the hazard posed by work with recombinant Etx, we have used a variant of Etx that contains a H149A mutation (Etx‐H149A), previously reported to have reduced, but not abolished, toxicity. The three‐dimensional structure of H149A prototoxin shows that the H149A mutation in domain III does not affect organisation of the putative receptor binding loops in domain I of the toxin. Surface exposed tyrosine residues in domain I of Etx‐H149A (Y16, Y20, Y29, Y30, Y36 and Y196) were mutated to alanine and mutants Y30A and Y196A showed significantly reduced binding to MDCK.2 cells relative to Etx‐H149A that correlated with their reduced cytotoxic activity. Thus, our study confirms the role of surface exposed tyrosine residues in domain I of Etx in binding to MDCK cells and the suitability of Etx‐H149A for further receptor binding studies. In contrast, binding of all of the tyrosine mutants to ACHN cells was similar to that of Etx‐H149A, suggesting that Etx can recognise different cell surface receptors. In support of this, the crystal structure of Etx‐H149A identified a glycan (β‐octyl‐glucoside) binding site in domain III of Etx‐H149A, which may be a second receptor binding site. These findings have important implications for developing strategies designed to neutralise toxin activity.
Perampanel: first‐in‐class AED for partial‐onset seizures
Authors: Chaplin Steve , Kelso Andrew
Published: March 2013

Perampanel (Fycompa), an AMPA receptor antagonist, is licensed as adjunctive treatment of partial‐onset seizures. In our New products review, Steve Chaplin presents the clinical data relating to its efficacy and adverse events and Dr Andrew Kelso discusses its place in the treatment of epilepsy.
Epigallocatechin‐3‐Gallate Inhibits Collagen Production of Nasal Polyp‐Derived Fibroblasts
Authors: Kang Jae Seong , Park Il‐Ho , Cho Jung‐Sun , Hong Sung‐Moon , Kim Tae Hoon , Lee Sang Hag , Lee Heung‐Man
Published: March 2013

Nasal polyps are chronic inflammatory conditions characterized by myofibroblast differentiation and extracelluar matrix accumulation. The major catechin from green tea is (−)‐epigallocatechin‐3‐gallate (EGCG), which has garnered attention for its potential to prevent oxidative stress‐related diseases. The purpose of this study was twofold: (i) to determine the effect of EGCG on fibroblast differentiation into myofibroblasts and extracellular matrix accumulation in transforming growth factor (TGF)‐β1‐induced nasal polyp‐derived fibroblasts (NPDFs) and (ii) to determine if the antioxidative effect of EGCG on reactive oxygen species (ROS) production in TGF‐β1‐induced NPDFs is involved in the aforementioned processes. TGF‐β1‐induced NPDFs were treated with or without EGCG. α‐smooth muscle actin (α‐SMA) and collagen type I mRNA were analyzed by reverse transcription‐polymerase chain reaction. α‐SMA protein was also detected using immunofluorescent staining. The amount of total soluble collagen was analyzed by Sircol collagen assay. ROS activity was measured by the nitroblue tetrazolium reduction assay and visualized by fluorescent microscopy. EGCG significantly inhibited expressions of α‐SMA and collagen type I mRNA and reduced α‐SMA and collagen protein levels at concentrations of 10–20 µg/mL. EGCG also inhibited TGF‐β1‐induced ROS production at the same concentrations. These results suggest the possibility that EGCG may be effective at inhibiting the development of nasal polyps through an anti‐oxidant effect. Copyright © 2013 John Wiley & Sons, Ltd.
Effect of the Potent Antiviral 1‐Cinnamoyl‐3,11‐Dihydroxymeliacarpin on Cytokine Production by Murine Macrophages Stimulated with HSV‐2
Authors: Petrera Erina , Coto Celia E.
Published: March 2013

The limonoid 1‐cinnamoyl‐3,11‐dihydroxymeliacarpin (CDM) isolated from leaf extracts of Melia azedarach L, has potent antiherpetic effect in epithelial cells. Since Meliacine, the partially purified extract source of CDM, has therapeutic effect on murine genital herpes, the potential use of CDM as microbicide against herpetic infections was studied here. To determine the cytotoxic effect of CDM, the MTT assay and acridine orange staining of living cells were performed. The antiherpetic action of CDM was measured by plaque reduction assay, and the immunomodulatory effect was determined by measuring the cytokine production using a bioassay and ELISA method. The results presented here showed that CDM inhibited Herpes Simplex Virus type 2 (HSV‐2) multiplication in Vero cells but did not affect its replication in macrophages which were not permissive to HSV infection. In macrophages, levels of TNF‐α, IFN‐γ, NO, IL‐6 and IL‐10 were increased by CDM used alone or in combination with HSV‐2. Besides, CDM not only synergized TNF‐α production combined with IFN‐γ, but also prolonged its expression in time. Results indicate that CDM inhibits HSV‐2 multiplication in epithelial cells and also increases cytokine production in macrophages, both important actions to the clearance of infecting virus in the mouse vagina. Copyright © 2013 John Wiley & Sons, Ltd.
The impact of Typhoon Jangmi (2008) on the midlatitude flow. Part II: Downstream evolution
Authors: Grams Christian M. , Jones Sarah C. , Davis Christopher A.
Published: March 2013

Extratropical transition (ET) of a tropical cyclone (TC) can modify the midlatitude flow and thus have implications for the weather and predictability in downstream regions such as North America or Europe. Albeit recurving and undergoing ET, the downstream impact of Typhoon Jangmi in September 2008 during the THORPEX Pacific Asian Regional Campaign (T‐PARC) was weak. In this study, we explore the physical processes inhibiting the reintensification of Jangmi and governing the forecast uncertainty during ET. The focus is on the relative contribution of the TC and the midlatitude flow. Quasi‐geostrophic diagnostics reveal that Jangmi is located south of and in phase with a midlatitude trough. Jangmi does not couple with the region favourable for reintensification ahead of the trough and subsequently decays. Instead, a weak frontal wave‐like cyclone develops. The role of the phasing of Typhoon Jangmi and the midlatitude Rossby wave pattern is tested in sensitivity experiments with the COSMO model in which Jangmi has been relocated. The simulations reveal two contrasting groups of scenarios. The first group reflects the weak actual ET and subsequent decay accompanied by a broad ridge over the Pacific. The second group is characterized by a strong ET with extratropical reintensification, the triggering of a pronounced Rossby wave train and downstream cyclogenesis. The displacement of Jangmi's initial position in the two contrasting groups is less than 1.25° (130 km). In the frame moving with the environmental background flow a critical bifurcation point for the track of Jangmi exists. The relative position to this bifurcation point determines whether Jangmi decays or reintensifies and triggers a Rossby wave train. A simple discrimination parameter is derived that allows for classifying the scenarios. The observed behaviour gives a simple explanation for the reduced predictability of the track and of the midlatitude flow in downstream regions during ET.
Rechnen und Bauen ‐ über den Einsatz des Computers im Bauwesen
Authors: Klooster T. , Permantier M.
Published: March 2013

Die Anwendung von Computergrafik und Animation spielt für Ingenieure und Architekten eine immer größere Rolle in ihrer praktischen Arbeit. Mit deren Einsatz bieten sich nicht nur für die Darstellung des fertigen Projektes, sondern auch während der Entwurfsphase neue Möglichkeiten. Visualisierungen verschiedener Entwurfsideen können die Kommunikation zwischen Ingenieur und Architekt und ihre Zusammenarbeit auf eine neue Grundlage stellen. Von den Vorraussetzungen, unter denen diese Zusammenarbeit funktioniert und von der besonderen Bedeutung, die dem computeranimierten Modell dabei zukommt, handelt der nachfolgende Aufsatz.
Bemessung von Zugstabsystemen mit Verankerungsteilen (Stabankern) aus Gußeisen mit Kugelgraphit
Authors: Kathage K.
Published: March 2013

Die Verwendung von industriell vorgefertigten Zugstabsystemen gewinnt in der modernen Architektur zunehmend an Bedeutung. Zugstabsysteme werden insbesondere bei filigranen Tragkonstruktionen des Hoch‐ und Industriebaus eingesetzt (z. B. zur Abspannung von Dachkonstruktionen, zur Unterspannung von leichten Stahl‐Glas‐Konstruktionen oder zur Ausbildung von Kreizverbänden). Der vorliegende Beitrag enthält Regeln für die Bemessung von Zugstabsystemen mit Zugstäben, die durch Verankerungsteile (Stabanker) aus Gußeisen mit Kugelgraphit (Gußsorten GGG 40 und GGG 40.3) mit entsprechend dimensionierten Anschlußblechen der Haupt‐Tragkonstruktion verbunden werden. Bei dieser Verbindung handelt es sich um eine gelenkige, zweischnittige Bolzenverbindung. Die in diesem Beitrag angegebene Vorgehensweise für die Ermittlung der Beanspruchbarkeiten ist Grundlage für die Erteilung allgemeiner bauaufsichtlicher Zulassungen für Zugstabsysteme mit Stabankern aus Gußeisen mit Kugelgraphit. Die Ermittllung der Beanspruchbarkeiten der Zugstäbe und der Anschlußbleche (Augenbleche) erfolgt dabei nach DIN 18800‐1 : 1990‐11, die Ermittlung der Beanspruchbarkeit der Stabanker (einschl. Bolzen) auf der Grundlage von Versuchen. Das dargestellte Bemessungsverfahren gilt für vorwiegend ruhende Beanspruchung. Es kann auch auf Zugstabsysteme mit Stabankern aus vergleichbaren Werkstoffen übertragen werden.
Eine Fachwerkbrücke in Leipzig
Authors: Schleicher W. , Stolze L.
Published: March 2013

Am nördlichen Stadtrand von Leipzig befindet sich in Leipzig‐Mockau das Kreuzungsbauwerk der Bundesbahnstrecken Leipzig‐Wahren ‐ Leipzig‐Engelsdorf sowie Neuwiederitzsch ‐ Leipzig‐Mockau mit der Bundesstraße B 2 und den Bahnstrecken Magdeburg und Bitterfeld nach Leipzig. In Zuge der Sanierung dieses Knotenpunktes erfolgte ein Ersatzneubau der Überführung der Strecke Wahren ‐ Engelsdorf über die Bahntrassen nach Magdeburg und Bitterfeld. Eine Einbauzeit von 10 Tagen für die 1650 t schwere neue Fachwerkbrücke erforderte die Vormontage neben der Bahnstrecke. Komplizierte Baugrundverhältnisse verursachten einen aufwendigen Quer‐ und Längsverschub in die Endlage.
Eine unerwartete Versagensform bei schlanken windbelasteten Kreiszylinderschalen
Authors: Schneider W. , Thiele R.
Published: March 2013

Bei sehr schlanken dünnwandigen windbelasteten Kreiszylinderschalen kann eine Versagensform auftreten, die bisher noch nicht untersucht wurde: heckseitiges Einknicken zwischen 0,14 h und 0,61 h. Es handelt sich dabei um eine Schaleninstabilität unter Verlust der Querschnittsform, die durch den spezifischen Anstrengungszustand infolge des über den Umfang ungleichmäßig angreifenden Windes möglich wird. Die Arbeit gibt den Geometriebereich für diese Versagensfigur an und erläutert die Voraussetzungen für deren Ausbildung. Verformungsplots zeigen die Variationsbreite des überraschenden Kollapsmusters und verdeutlichen die grundsätzlichen Aussagen.
Tafeln der Torsionskenngrößen von Walzprofilen unter Verwendung von FE‐Diskretisierungen
Authors: Wagner W. , Sauer R. , Gruttmann F.
Published: March 2013

Ausgehend von der Differentialgleichung und den Randbedingungen der St.‐Venantschen Torsionstheorie wird eine Finite‐Element‐Formulierung zur Ermittlung der Verwölbungen beliebiger Querschnitte beschrieben. Hierbei werden keine vereinfachende Annahmen hinsichtlich Querschnittsgeometrie sowie Verlauf der Verwölbungen getroffen. Auf dieser Basis werden die Torsionskennwerte der gängigen Walzprofile bestimmt. Die gewonnenen Ergebnisse werden den DIN‐Tafelwerten gegenübergestellt, welche auf den Berechnungen von Bornscheuer, beruhen. Die Unterschiede werden diskutiert.
Numerische Vergleichsanalyse zu Beulversuchen an Torussegmenten aus Stahl unter Axialdruck
Authors: Velickov D. , Maur J. , Schmidt H.
Published: March 2013

Mit Hilfe des FE‐Programmsystems ANSYS (5.3) werden unter Beachtung der im Entwurf zur DASt‐Ri 017 enthaltenen Richtlinien für numerisch gestützte Beulsicherheitsnachweise Vergleichsberechnungen zu Beulversuchen an zwei axialgedrückten stählernen Torussegmenten mit positiver bzw. negativer Krümmung durchgeführt.

Aufgrund des Vergleiches von Berechnungs‐ und Versuchsergebnissen sowie der hier bei Anwendung der E‐DASt‐Ri 017 auftretenden Besonderheiten werden kritische Anmerkungen zu diesem Regelwerk formuliert.
Einfluß von Punktversteifungen auf die Biegedrillknicklast einfachsymmetrischer Stäbe
Authors: Gosowski B.
Published: March 2013

Behandelt wurde die Lösung des Problems der elastischen Biegedrillknickung eines an den Enden beliebig gelagerten dünnwandigen Bauelementes mit festem einfachsymmetrischem offenem Querschnitt mit punktförmigen Längs‐ und Querversteifungen auf der Länge unter Druck‐ und Biegebeanspruchung in der Symmetrieebene. Unter Nutzung von eigenen EDV‐Programmen, erstellt aufgrund der behandelten Lösung, wurde eine eingehende numerische Analyse der auf der Länge punktförmig versteiften Stahlbauelemente durchgeführt. Dabei wurden querversteifte (in der Ebene der kleineren Biegesteifheit) sowie längsversteifte (mit Querrippen, die mit Flanschen und dem Steg verbunden sind) Stützen und Balken untersucht. Die auf den Diagrammen und in den Tabellen dargestellten Ergebnisse ermöglichen es, den Einfluß der Punktversteifungen auf die kritische Belastung der räumlichen Stabilität der untersuchten Elemente zu beurteilen. Sie bieten außerdem die Möglichkeit, eine Reihe von praktischen Hinweisen zu formulieren.
Haus der Dienstleistungen der Landesgirokasse Stuttgart am Bollwerk
Authors: Jehlicka M. , Horstkötter K. , Beyerlein R. , Janku H.
Published: March 2013

Die Landesgirokasse Stuttgart hat nach dem Entwurf des Architekturbüros Behnisch & Partner ein neues Dienstleistungszentrum Bollwerk gebaut. Mit der Tragwerksplanung wurde das Ingenieurbüro Leonhardt, Andrä und Partner beauftragt.

Über die Besonderheiten der Berechnung und der Bauausführung wird in folgendem Beitrag berichtet.
Verbundstützen und Querkraftanschlüsse der Verbundflachdecken beim Millennium Tower
Authors: Angerer Th. , Rubin D. , Taus M.
Published: March 2013

Es wird das Konzept für die Wahl der Verbundstützenquerschnitte vorgestellt und erläutert, wie die Stützenlasten ermittelt wurden und die Bemessung der Stützen erfolgte. Weiters wird beschrieben, wie die Verbunddeckenquerkräfte in die Verbundstützen im Kalt‐ und Warmzustand eingeleitet werden. Eine erstmals im Verbundbau in dieser Größenordnung angewandte Verwendung von Setznägeln und ‐bolzen, wird beschrieben. Ergänzt wird dieser Beitrag durch die Beschreibung des Anschlusses Verbunddeckenträger‐Stahlbetonkern.
Innovation im Verbundbrückenbau ‐ Talbrücke Oberhartmannsreuth
Authors: Allmeier S. , Frenzel J. , Schiefer S. , Seidl G. , Weber J.
Published: March 2013

Im Beitrag wird ein neues Konzept im Verbundbau vorgestellt ‐ wirtschaftlich und konstruktiv, aber auch gestalterisch anspruchsvoll. Die Konzeption und Durchführung einer Talbrücke in der VFT‐Bauweise wird von den beteiligten Partnern auf Vorteile und Problempunkte beleuchtet. Massenauszüge, Ablaufbeschreibungen und Konstruktionsdetails geben einen Einblick in die Erfahrungen beim Bau der Oberhartmannsreuther Talbrücke.
Dauerhafte Ausführung von Hängeranschlüssen an stählernen Bogenbrücken
Authors: Günther G. H. , Hortmanns M. , Schwarzkopf D. , Sedlacek G. , Bohmann D.
Published: March 2013

In den letzten Jahren sind vereinzelt Schäden an Stabbogenbrücken aufgrund nichtruhender Belastung aufgetreten, die zum Teil zu einer Beeinträchtigung der Standsicherheit der Brücken geführt haben. Eine wichtige dynamische Einwirkung sind Regen‐Wind‐induzierte Schwingungen an den Hängern. In diesem Beitrag werden daher Hilfen zur Bemessung und Konstruktion von Hängeranschlüssen im Hinblick auf die Ermüdungsfestigkeit unter Berücksichtigung statischer und dynamischer Anforderungen gegeben. Es werden vereinfachte Verfahren vorgestellt, mit deren Hilfe die Anschlüsse hinsichtlich iher Schwinungsgefährdung klassifiziert und ohne die Anwendung von FE‐Programmen auf Dauerfestigkeit überprüft werden können.
Untersuchungen zum Knittern von Sandwichelementen mit ebenen und gesickten Deckschichten
Authors: Ewert E. , Banke F. , Schulz U. , Wolters M.
Published: March 2013

Der Beitrag geht auf das Stabilitätsverhalten von biegebeanspruchten Sandwichelementen ein. Es wird mittels der Methode der Finiten Elemente der Einfluß der Schaumorthotropie, der Haftfestigkeit zwischen Deckschicht und Schaumkern und der Schaumkerndicke auf die Knitterspannung untersucht. Die Approximation numerisch für Sandwichelemente mit gesickten Deckschichten ermittelter Knitterspannungen führte zu einem Formelausdruck, mit dem der Stabilitätsnachweis derartiger Elemente erfolgen kann. Es ist schließlich eine experimentelle Verifikation vorgenommen worden.
Zur Nachrechnung, Restnutzungsdauerberechnung und Ertüchtigungsuntersuchung der Eisenbahnhochbrücke über den Nord‐Ostsee‐Kanal in Rendsburg
Authors: Graße W. , Schmachtenberg R. , Geißler K.
Published: March 2013

Für die ca. 90 Jahre alte Eisenbahnhochbrücke Rendsburg wurden eine durchgängige statische Nachrechnung, Restnutzungsdauerermittlung sowie Ertüchtigungsuntersuchung durchgeführt. Der folgende Beitrag beschreibt die einzelnen Bauwerke mit den jeweiligen Besonderheiten in bezug auf die realitätsnahe Modellierung der Systeme. Aufgrund der Bedeutsamkeit des Bauwerkes als Nadelöhr für den Skandinavienverkehr wurde die Anwendung zusätzlicher Methoden wie z.B. von Messungen zur besseren Erfassung des Systemtragverhaltens praktiziert. Abschließend werden Verstärkungsmaßnahmen diskutiert, deren Erarbeitung die Grundlage für die Kostenberechnungen zur Ertüchtigung der Hochbrücke für verschiedene mögliche Streckenklassen bildet.
The 2010–2012 drought in England and Wales
Authors: Kendon Mike , Marsh Terry , Parry Simon
Published: March 2013

The inherent variability of the UK’s climate achieved an extreme expression in 2012 when one of the most significant prolonged droughts for a century was dramatically terminated by the wettest April to July over England and Wales in almost 250 years. Through late spring and summer, runoff and aquifer recharge rates increased steeply and there were numerous instances of flooding, underlining a hydrological transformation with no close modern parallel at this time of year.

This paper reviews the development, severity and impacts of the 2010–2012 drought. It is intended that a companion paper will examine the exceptionally wet conditions which began in April 2012 and resulted in runoff and aquifer recharge patterns very rarely experienced during the summer half‐year.
Generalized skyrmions in QCD and the electroweak sector
Authors: Ellis John , Karliner Marek , Praszalowicz Michal
Published: March 2013

Abstract

We discuss the stability and masses of topological solitons in QCD and strongly-interacting models of electroweak symmetry breaking with arbitrary combinations of two inequivalent Lagrangian terms of fourth order in the field spatial derivatives. We find stable solitons for only a restricted range of the ratio of these combinations, in agreement with previous results, and we calculate the corresponding soliton masses. In QCD, the experimental constraints on the fourth-order terms force the soliton to resemble the original Skyrmion solution. However, this is not necessarily the case in strongly-interacting models of electroweak symmetry breaking, in which a non-Skyrmion-like soliton is also possible. This possibility will be constrained by future LHC measurements and dark matter experiments. Current upper bounds on the electroweak soliton mass range between 18 and 59 TeV, which would be reduced to 4.6 to 8.1 TeV with the likely sensitivity of LHC data to the fourth-order electroweak Lagrangian parameters.
Influence of chronic exercise on serum cortisol levels in older adults
Authors: Corazza Danilla Icassatti , Sebastião Émerson , Pedroso Renata Valle , Andreatto Carla Andreza Almeida , de Melo Coelho Flavia Gomes , Gobbi Sebastião , Teodorov Elizabeth , Santos-Galduróz Ruth Ferreira
Published: March 2013

The circulating level of cortisol is regulated by the hypothalamic-pituitary-adrenal axis through a neuroendocrine feedback circuit. This circuit can be activated by physiological stimuli such as stress, diseases, and exercise. High levels of serum cortisol hormone normally occur as a byproduct of aging, and can cause several types of damage to the organism and exacerbate immunosenescence. There is a great deal of variability in the cortisol response with regard to type, intensity, volume, and frequency of exercise. However, these relationships have been extensively studied with respect to the acute effects of exercise. Despite the well-known effects of acute exercise on cortisol response, it is unclear how it is affected by chronic exercise and the aging process. Therefore, the aim of this study was to conduct a review of studies that attempt to analyze the influence of chronic exercise on serum cortisol hormone in older people. In order to accomplish this goal, a review from 1970 to June 2012 period was performed using the following databases: Biological Abstracts, PsycINFO, PubMed/Medline, and the Web of Science. Eight articles met the criteria used in this study. Based on the included articles, chronic exercise may influence the serum levels of cortisol levels in older people. Despite this evidence, these results may not be generalized to the entire population of older people, given the few number of studies and especially because the studies showed diversity in variables and methodologies.
Priority Patient Safety Issues Identified by Perioperative Nurses
Authors: Steelman Victoria M. , Graling Paula R. , Perkhounkova Yelena
Published: March 2013

Much of the work done by perioperative nurses focuses on patient safety. Perioperative nurses are aware that unreported near misses occur every day, and they use that knowledge to prioritize activities to protect the patient. The purpose of this study was to identify the highest priority patient safety issues reported by perioperative RNs. We sent a link to an anonymous electronic survey to all AORN members who had e‐mail addresses in AORN's member database. The survey asked respondents to identify top perioperative patient safety issues. We received 3,137 usable responses and identified the 10 highest priority safety issues, including wrong site/procedure/patient surgery, retained surgical items, medication errors, failures in instrument reprocessing, pressure injuries, specimen management errors, surgical fires, perioperative hypothermia, burns from energy devices, and difficult intubation/airway emergencies. Differences were found among practice settings. The information from this study can be used to inform the development of educational programs and the allocation of resources to enhance safe perioperative patient care.
Drain's Perianesthesia Nursing: A Critical Care Approach
Authors: Mariotti Nadine A.
Published: March 2013

Jan Odom‐Forren, Drain's Perianesthesia Nursing: A Critical Care Approach, 6th edition, 2013, Elsevier Saunders, 839 pages, hardcover
Lead with Purpose: Giving Your Organization a Reason to Believe in Itself
Authors: Tinkham Michelle R.
Published: March 2013

Lead with Purpose: Giving Your Organization a Reason to Believe in Itself, John Baldoni, 2011, AMACOM Books, 207 pages, hardcover
Clinical Issues—April 2013
Authors: Ogg Mary J. , Wood Amber
Published: March 2013

This Month

Eye examinations for health care personnel using lasers

Key words: lasers, eye examinations, laser eye injuries.

The difference between a laser safety specialist and a laser safety site contact

Key words: laser, laser safety specialist, laser safety site contact, laser safety officer.

Isolation precautions during care of a patient with a herpes simplex virus infection of the eye

Key words: herpes simplex virus (HSV), herpes, eye infection, ocular infection, contact isolation precautions, standard precautions, personal protective equipment.

Environmental cleaning of blood spills on the floor of the OR

Key words: OR cleaning, environmental cleaning, blood spills.
Human Factoring in Sterile Processing Departments
Authors: Hilsgen Jana
Published: March 2013

Human Factoring in Sterile Processing Departments, Michele DeMeo, Self‐published, https://www.createspace.com/4010422 2012, 62 pages, softcover
A Quality Improvement Project for–Safe and Effective Patient Positioning During Robot‐Assisted Surgery
Authors: Sutton Shauna , Link Terri , Makic Mary Beth Flynn
Published: March 2013

During the initiation of a new robotic surgery program, a quality improvement team explored different techniques for positioning patients in the lithotomy and steep Trendelenburg position during robot‐assisted procedures. Concerns associated with placing patients in the steep Trendelenburg position include the patient slipping toward the head of the bed and experiencing hemodynamic changes that may result in a rise in blood pressure, increased intraocular and intracranial pressures, and difficulty with ventilation, particularly in patients with a high body mass index. Skin integrity is also of concern because perioperative personnel are responsible for protecting the patient's skin from excessive sheer, friction, and injury. The quality improvement team evaluated and compared two positioning devices: an air‐inflated positioning device and high‐density foam padding. Both methods allowed personnel to position the patient without compromise; the surgeons performing the robot‐assisted procedures preferred the high‐density foam padding.
Proper Use of Surgical N95 Respirators and Surgical Masks in the OR
Authors: Benson Stacey M. , Novak Debra A. , Ogg Mary J.
Published: March 2013

Proper adherence to infection control precautions, including appropriate selection and use of personal protective equipment (PPE), is of significant importance to the health and well‐being of perioperative personnel. Surgical masks are intended for use as a barrier to protect the wearer's face from large droplets and splashes of blood and other body fluids; however, surgical and high‐filtration surgical laser masks do not provide enough protection to be considered respiratory PPE. Potential exposure to airborne contaminants and infectious agents, including those present in surgical smoke, necessitates the use of respiratory PPE, such as a surgical N95 particulate filtering facepiece respirator. Filtering facepiece respirators greatly reduce a wide size range of particles from entering the wearer's breathing zone and are designed to protect the user from both droplet and airborne particles. Every health care worker who must use a respirator to control hazardous exposures in the workplace must be trained to properly use the respirator and pass a fit test before using it in the workplace.
What's New in the Transplant OR?
Authors: Paramesh Anil S.
Published: March 2013

Advancements in transplantation offer promising treatment options for a variety of diseases. Organ donation, an essential part of organ transplantation, may be performed at hospitals even if the facility is not a transplant center; therefore, perioperative nurses should be aware of developments in transplantation and the implications for patient care at their facilities. Considerations for organ transplant protocols include the type of documentation required, the elements of the transplant OR time out, and the use of intraoperative anti‐rejection medications. Considerations for organ donation protocols include issues specific to a deceased donor, a living donor, or a donation after cardiac death. Newer developments in the transplant OR include laparoscopic kidney donation and transplantation, kidney paired donation transplantation, other living donor procedures, and transplantation procedures using robotic technology.
Instituting Code Blue Drills in the–OR
Authors: Lanfranchi Joy A.
Published: March 2013

A code blue in the OR is a low‐volume, high‐risk event. To be effective during a code blue event, perioperative personnel must be able to properly execute a response plan and perform seldom‐used skills and procedures. I developed and implemented a code blue drill educational experience for OR staff members that included a review of code blue policy, how to use a defibrillator, and simulated code blue scenarios. In addition, I worked with educational facilitators to provide an assessment of the personnel who performed the simulated code blue drills to identify key learning opportunities, such as gaps in communication, poor performance of cardiopulmonary resuscitation, ineffective delegation skills, and lack of assertiveness. One month after the educational experience, all team members passed an observed competency for responding to a code blue in a simulation laboratory. These results show the effectiveness of the educational experience as part of the code blue drills program in the hospital's main OR.
Using Simulation Training to Improve Perioperative Patient Safety
Authors: Mullen Linda , Byrd Debra
Published: March 2013

Simulation learning provides medical and nursing personnel with the opportunity to develop and refine their skills without putting patients at risk. Faced with ensuring the competence of a large number of new staff members, the management team at one facility implemented a simulation training program. Surgical team members are able to participate in an ongoing program of simulated scenarios involving surgical drape fires and airway fires, cardiac arrest of patients in the supine position and prone position, respiratory depression in the postanesthesia care unit, and malignant hyperthermia. The simulations help OR staff members identify problems that can happen during real emergencies and help them work as a team to prepare for events that may represent life‐threatening situations for patients.
Review of Multidetector Computed Tomography Angiography as a Screening Modality in the Assessment of Blunt Vascular Neck Injuries
Authors: Liang Teresa , McLaughlin Patrick D. , Louis Luck , Nicolaou Savvas
Published: March 2013

Blunt vascular neck injuries (BVNI), previously thought to be rare, have demonstrated increasing incidence rates in recent literature and are associated with significant mortality and morbidity. A radiologist needs to efficiently recognize these injuries on preliminary screening to enable initiation of early management. When initiation of accurate management is started promptly, decreased rates of postinjury complications, for example, stroke, have been demonstrated. This article reviews the incidence, pathophysiology, and rationale for screening for these BVNI injuries. The utility of computed tomography angiography (CTA) as the potential new criterion standard as the screening and follow-up imaging modality for BVNI will be discussed. The application of new multidetector CTA techniques available, such as dual-energy CT and iterative reconstruction, are also reviewed. In addition, the characteristic imaging findings on CTA and the associated Denver Grading scale for BVNI will be reviewed to allow readers to become familiar with the injury patterns and to understand the prognostic and clinical implications, respectively. Examples of the spectrum of injuries, potential injury mimics, and different artifacts on multidetector CTA are shown to help familiarize readers and allow them to successfully and confidently recognize a true BVNI.
Evolutionary psychology is not the only productive evolutionary approach to understanding consumer behavior
Authors: Downes Stephen M.
Published: March 2013

I respond to Vladas Griskevicius and Douglas T. Kendrick (G&K) and Gad Saad's (S) defenses of the view that Consumer Studies would benefit from the appeal to evolution in all work aimed at understanding consumer behavior. I argue that G&K and S's reliance on one theoretical perspective, that of evolutionary psychology, limits their options. Further, I point out some specific problems with the theoretical perspective of evolutionary psychology. Finally, I introduce some alternative evolutionary approaches to studying human behavior that could profitably be adopted in consumer research.
Paranoia and post-traumatic stress disorder in the months after a physical assault: a longitudinal study examining shared and differential predictors
Authors: Freeman D. , Thompson C. , Vorontsova N. , Dunn G. , Carter L.-A. , Garety P. , Kuipers E. , Slater M. , Antley A. , Glucksman E. , Ehlers A.
Published: March 2013

Background

Being physically assaulted is known to increase the risk of the occurrence of post-traumatic stress disorder (PTSD) symptoms but it may also skew judgements about the intentions of other people. The objectives of the study were to assess paranoia and PTSD after an assault and to test whether theory-derived cognitive factors predicted the persistence of these problems.

Method

At 4 weeks after hospital attendance due to an assault, 106 people were assessed on multiple symptom measures (including virtual reality) and cognitive factors from models of paranoia and PTSD. The symptom measures were repeated 3 and 6 months later.

Results

Factor analysis indicated that paranoia and PTSD were distinct experiences, though positively correlated. At 4 weeks, 33% of participants met diagnostic criteria for PTSD, falling to 16% at follow-up. Of the group at the first assessment, 80% reported that since the assault they were excessively fearful of other people, which over time fell to 66%. Almost all the cognitive factors (including information-processing style during the trauma, mental defeat, qualities of unwanted memories, self-blame, negative thoughts about self, worry, safety behaviours, anomalous internal experiences and cognitive inflexibility) predicted later paranoia and PTSD, but there was little evidence of differential prediction.

Conclusions

Paranoia after an assault may be common and distinguishable from PTSD but predicted by a strikingly similar range of factors.