bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of antioxidant‐enriched foods on plasma Coenzyme Q10 and total antioxidant capacity
Authors: Arsenio Leone , Caronna Silvana , Dall'Aglio Elisabetta , Frega Natale G. , Pacetti Deborah , Boselli Emanuele , Tiano Luca , Principi Federica , Littarru Gian Paolo
Published: October 2008

Twenty healthy subjects integrated their diet with two types of products sequentially: In the first phase (first 14 days), the volunteers were given the following food items not supplemented with vitamin E (vit. E) or Coenzyme Q10 (CoQ10): breakfast, 250 mL skimmed milk; mid‐morning snack, 330 mL fruit juice; mid‐afternoon snack, low‐fat yogurt 125 g; after dinner, low‐fat dessert 110 g. In the second phase, from day 14 to day 35, the same items were added with vit. E and CoQ10 (a total daily supplementation of 19.4 mg CoQ10 and 13.7 mg vit.E). After taking the supplemented products for 2 weeks, plasma CoQ10 reached 1.30 µg/mL, nearly twice the initial values. These levels further increased after 3 weeks of supplementation. Vit. E levels significantly (p <0.001) increased only after 3 weeks of supplementation, reaching 7.9 ± 2.8 µg/mL, 39% more than the initial value. The total plasma fatty acid pattern did not change substantially throughout the study. The increase of the total antioxidant capacity of plasma was significant (p <0.001) for days 28 and 35, with values close to 0.24 ± 0.09 mM Trolox (a nearly 60% increase).
Transformation of gem‐Dicyanoethenes by Samarium: Direct Formation of Indenes or Direct Decyanation with in Situ Disilylation
Authors: Liu Yongjun , Zhang Fuqiang , Qi Yan , Zhang Yongmin , Zhang Shusheng
Published: October 2008

Intramolecular cyclization of 1,1‐diaryl‐2,2‐dicyanoethenes promoted by samarium metal in DMF in the presence of TMSCl allowed direct construction of the indene core, whereas 1‐alkyl‐1‐aryl‐2,2‐dicyanoethenes underwent intermolecular coupling cyclization and decyanation under the same conditions. Simultaneously, disilylation occurred at the amino moiety resulting from the reduction of the cyano group. However, only simple reduction of the C=C bonds is observed when a trace amount of water presented.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Open Problems in Chemical Topology (Eur. J. Org. Chem. 30/2008)
Authors: Fenlon Edward E.
Published: October 2008

The cover picture shows a scheme depicting the open problem of the lower size limit for molecular knots. It also shows enantiomorphous conformations of a topological rubber glove – the colored figure eight knot. It is unknown whether the enantiomerization barrier for a topological rubber glove can be measured. A polyethylene trefoil knot, a trefoil rotaxaknot, and a Whitehead link are also shown. The syntheses of these topologically interesting compounds remain open problems. Details are presented in the Microreview by E. E. Fenlon on p. 5023 ff. The photograph of the rubber gloves was taken by Ethan S. Fenlon. Matt Watson is thanked for helping with the graphic of the polyethylene knot.
Signale aus Dahlem
Authors: Unterstell Rembert
Published: October 2008

Die DFG fordert auf ihrer Festversammlung die Überwindung von Grenzen in der Forschung – zwischen Fächern, Nationen und Geschlechtern
Am seidenen Faden der Reproduktion
Authors: Henke Alexander , Michel Caroline , Gromoll Jörg
Published: October 2008

Ohne Lutropin keine Nachkommen: Hormone spielen bei der Fortpflanzung die entscheidende Rolle. Ihre molekularen Mechanismen werden nun entschlüsselt
Aufbruch in Zentralasien
Authors: Bienert Hans‐Dieter
Published: October 2008

Wie die Wissenschaft in Kasachstan und Usbekistan internationalen Anschluss sucht
Jahrmarkt der Mathematik
Authors: Rateike Jutta
Published: October 2008

Auf dem Ausstellungsschiff, am Vortragsstand, im Abendprogramm: Beim Wissenschaftssommer 2008 machten DFG‐Projekte das verpönte Fach zum Erlebnis
Run Out of Landslides – Continuum Mechanics versus Discontinuum Mechanics Models
Authors: Poisel Rainer , Preh Alexander , Hungr Oldrich
Published: October 2008

In general, a rock slope failure leads to the detachment of a rock mass consisting of a mass of blocks. During the last few years continuum mechanics as well as discontinuum mechanics numerical codes have been developed for modelling the run out of these masses. In order to compare both methods, Punta Thurwieser Rock Avalanche and Frank Slide were modelled by the continuum mechanics numerical code DAN3D as well as by the distinct element method PFC3D modified for run out modelling. The simulations showed that the parameters necessary to get results coinciding with observations in nature are completely different and that Frank run out was a real “slide” of a coherent mass, whereas Punta Thurwieser run out was a rock mass fall with much internal movement. The parameters for a run out simulation, therefore, have to be chosen in such a way that the simulation gives a rock mass fall in one particular case and a slide of a coherent mass in another, corresponding to the real conditions. Therefore, the prediction of the run out kinematics and the fixing of the parameters is a demanding task in each case when modelling run outs.
Recent Developments in Rock Mechanics as Applied to Earthquake Dynamics
Authors: Uenishi Koji , Sakurai Shunsuke
Published: October 2008

This contribution summarizes some new findings related to the applied study of rock‐ and geomechanics in the field of engineering seismology. Our interest here is especially devoted to the influence of high‐frequency seismic waves on the damage of underground structures, which are considered to be earthquake‐resistant: On the occasion of the 1995 Hyogo‐ken Nanbu (Kobe) and the 2004 Niigata‐ken Chuetsu, Japan, earthquakes, unique and previously unrecognised damage to the underground structures was found both at depth and near the surface. Two‐dimensional elastodynamic analyses “inversely” show that the observed damage patterns were induced most likely by the dynamic interaction of vertical (longitudinal) oscillations of relatively high frequencies with the tunnels. The results also suggest that, contrary to the structures on the surface, underground structures subjected to dynamic waves vibrate with their surroundings and they are expected to function as sensors that respond only to waves of specific characters.
Russia Wharf Tunnelling Project
Authors: Skalla Gerald M.
Published: October 2008

The Silver Line Phase II in Boston, USA, (Logan Airport to South Station) includes the crossing of the Russia Wharf, a 100 year old, three building complex, each seven stories high. The first use of ground freezing and NATM in the US enabled these office buildings to stay fully operational and minimized the impacts on the tenants and these old structures while tunnelling underneath. Mitigation of settlements included temporary and permanent underpinning, raising and lowering of building columns and facades and the use of ground freezing which also created stable face conditions for the NATM mining operation only a few feet below surface.
Statentunnel in Rotterdam – Ausführungserfahrungen von Vereisungsbohrungen und der Vereisung von Querschlägen
Authors: Wenke Markus , Willner Michael
Published: October 2008

Der Statentunnel, erbaut im Auftrag der Rotterdams Electrische Tram, stellt für den Großraum Rotterdam eine deutliche Infrastrukturverbesserung für Pendler aus dem Umland dar. Die schwierigen geologischen Verhältnisse und die Querung von Hauptverkehrswegen in einem stark bebauten Gebiet erfordern Vereisungsmaßnahmen für die Herstellung von fünf Querschlägen, die zwei benachbarte mit einer TBM aufgefahrene Tunnelröhren verbinden. Die Herstellung der Vereisungsbohrungen unter engen Platzverhältnissen und eine Reihe zusätzlicher logistischer Randbedingungen erforderten ein hohes Maß an vorausschauender Planung. Darüber hinaus waren die Vermessung und die sorgfältige Ausführung zur Erreichung der geforderten Lagegenauigkeit der Vereisungsbohrungen wesentlich für die erfolgreiche Abwicklung des Projekts. Die mit einer Solelösung aus CaCl2 durchgeführte Baugrundvereisung erlaubte das Auffahren der Querschläge in Abschnitten mittels NÖT und nach der Ausführung von Abdichtungsmaßnahmen mit PVC Folien den Einbau der Betoninnenschale.
Design and Construction of the Venaus Powerhouse Cavern in Calcschists
Authors: Barla Giovanni , Fava Adriano Ruggero , Peri Guido
Published: October 2008

This paper examines the design and observed performance during construction, associated with staged excavation and support requirements of the Venaus powerhouse cavern, a component of the Pont Ventoux‐Susa hydroelectric scheme (in Northern Italy, near the city of Torino), which has been recently put into operation. This cavern, with a maximum height of 49 m, a length of 50 m, and a span of some 23 m, has been excavated in calcschists at a depth of 250 m below surface. Rock reinforcement consisted essentially of 9 to 15 m long primary rock anchors, for long term support, and 6 m long secondary rock dowels, together with a 25 cm thick reinforced shotcrete lining. Following comprehensive geological and geomechanical investigations with laboratory and in situ testing, design analyses have been performed by numerical modelling with both continuum and discontinuum methods. On the basis of the observed performance during early excavation of the upper cross section of the cavern, a discontinuum model, calibrated by back analysis procedures, was used for predicting the overall excavation stability. It is noteworthy that the design concepts adopted allowed this large cavern to be excavated and stabilized without the use of a cast‐in‐place concrete arch for roof support.
Die Detektionseffizienz von Vorausbohrungen im Tunnelbau
Authors: Ziegler Hans‐Jakob
Published: October 2008

Vor allem im Zusammenhang mit den großen Tunnelprojekten werden Vorausbohrungen zur Erkundung des Gebirges systematisch durchgeführt. Wie die Erfahrungen vom Lötschberg‐ und Gotthard‐Basistunnel zeigen, handelt es sich dabei um ein effizientes Hilfsmittel, um “unerwünschte Ereignisse” wie Schlamm‐ und Wassereinbrüche oder das Anfahren von unerwarteten Störungszonen zu vermeiden. Nur in drei Fällen traten solche “unerwünschten Ereignisse” bisher auf der betrachteten, ausgebrochenen Tunnelstrecke von insgesamt etwa 100 km auf. Dies zeigt klar den großen Nutzen von Vorausbohrungen für die Arbeits‐ und Planungssicherheit im modernen Tunnelbau. Die vorgestellten Beispiele belegen aber auch, dass auch mit den effizientesten Vorausbohrungen die Eintretenswahrscheinlichkeit von “unerwünschten Ereignissen” nie Null sein wird.
Theoretical and Applied Case Studies of Seismic Imaging in Tunnelling
Authors: Dickmann Thomas
Published: October 2008

Seismic measurements during tunnel operations aim at images of maximum spatial resolution. However, there are still principal limitations of the method applied in the tunnel with regard to spatial resolution by the signal frequency and attenuation and by the small angular illumination coverage. A finite‐difference simulation of elastic wave propagation had been performed to compute a synthetic tunnel seismic reflection survey. Synthetic data are used optimizing the best practice tunnel data processing sequence for both P‐ and S‐waves because every step between the acquisition of the seismic data and the derivation of the final image influences the final seismic resolution. Here, especially the use of attenuation models compensate amplitude loss as well as dispersion by an inverse Q‐filtering and the use of a spatially variable velocity model yielding the right image position of a reflecting geological element in space. The transfer and capability of this practice to real tunnel application is finally demonstrated by the case study of the tunnel seismic prediction method in the Koralm tunnel project in Austria.
Geophysikalische Vorauserkundung von Verkarstungs‐ und Störungszonen bei der TVM‐Auffahrung des Katzenbergtunnels
Authors: Richter Thomas , Boll Samuel , Weh Markus
Published: October 2008

Die maschinelle Auffahrung des Katzenbergtunnels (Deutschland) erforderte in beiden Röhren die Durchörterung eines etwa 520 m langen Gebirgsabschnitts im stark verkarstungsanfälligen Gestein des jurassischen Oxfordkalks (Weißjura). Die Erkennung von größeren offenen oder verfüllten Hohlräumen war für den Vortrieb und ist insbesondere für den späteren Betrieb des Tunnels eine entscheidende Voraussetzung. Die modernen Verfahren der Bohrloch‐Radar‐Technologie sind geeignet, Verkarstungs‐ und Störungszonen im Tunnelvorfeld zu lokalisieren. Diese neue Technologie wurde ergänzend zur Sondierung mittels Bohrungen erstmalig bei einem maschinellen Vortrieb eingesetzt. Die in der Regel steilstehenden, N‐S‐streichenden und korrosiv aufgeweiteten Karststrukturen konnten geophysikalisch mehrheitlich geortet, in ihrer Lage und Orientierung im Vollraum prognostiziert und anhand des Vergleichs mit den geologischen Ortsbrustkartierungen überprüft werden. Aus der Gegenüberstellung, Bewertung und Wichtung von angetroffenen und prognostizierten Strukturen konnten mittels Extrapolation dieser Ergebnisse verbesserte Aussagen zum Tunnelumfeld und zur Tunnelbettung gemacht werden. Der Artikel erläutert Einsatzmöglichkeiten, Nachweisgrenzen, Auflösung und Einsatzspektrum der Bohrloch‐Radar‐Technologie am Beispiel der abgeschlossenen Vorauserkundung im Katzenbergtunnel.
Exploration Ahead of a Tunnel Face by TSWD – Tunnel Seismic While Drilling
Authors: Brückl Ewald , Chwatal Werner , Mertl Stefan , Radinger Alexander
Published: October 2008

Geological and geophysical investigations, as well as drilling have brought the quality of geotechnical prognosis for tunnels to a high standard. However, the remaining risk during tunnel construction is still considerable, especially in case of construction by a tunnel boring machine (TBM). Seismic imaging of faults and other geological features affecting the construction ahead of a tunnel face can supply valuable information to reduce this risk. These methods are based on Vertical Seismic Profiling (VSP) locating sources and receivers in the tunnel and generating seismic waves by small blasts or mechanical devices. A fundamental problem in the application of this method is that reflectors (fault zones, petrologic boundaries, or similar) are imaged at their intersection with the tunnel axis only in case they are orthogonal to this axis. Reflectors oriented obliquely to the tunnel axis may be imaged perfectly. However, they must be extrapolated to their intersection with the tunnel axis, thus imposing major uncertainties on prediction.

Therefore it was decided to concentrate on Tunnel Seismic While Drilling (TSWD), an alternative method, which uses the vibrations produced by the cutting head of the TBM as seismic source. Continuous monitoring is possible by this method and the above mentioned problem may be overcome. Conventional seismic traces are extracted from the recordings by the use of a pilot signal recorded near the cutting head of the TBM. First results from a pilot study accompanying the construction of a gallery in the Gesäuse mountain range, Styria, Austria are presented. The bandwidth of the seismic signals is >200 Hz, a high signal to noise ratio is achieved, and excellent conventional seismic traces are extracted. Thus the most important component of the whole method has been realised successfully. Additional aspects of the method are discussed and an outlook to the continuation of the pilot study is given.
Technische Möglichkeiten und praktische Erfahrungen für tiefe Erkundungsbohrungen im Tunnelbau
Authors: Kogler Kurt
Published: October 2008

Tiefe Erkundungsbohrungen sind Grundlage und Voraussetzung für die Planung und Ausführung von großen Tunnelprojekten. Dabei spielen die Auswahl der Erkundungsmethode und der Einsatz der dazu erforderlichen Gerätschaften eine wesentliche Rolle. Der Beitrag gibt einen Überblick über die Bohrmethoden zur Untergrunderkundung und berichtet über praktische Erfahrungen aus Bohrarbeiten für tiefliegende Tunnelprojekte.
Druckstollen Limberg – Bemessung, Ausführung und Erfahrung im Bau
Authors: Zenz Gerald , Wagner Erich , Larcher Markus , Stering Paul
Published: October 2008

Der Ausbau von Hochdruckwasserkraftanlagen für den Turbinen‐ und Pumpbetrieb erfordert eine optimierte hydraulische Auslegung des Triebwasserwegs mit der Anordnung des Wasserschlosses zur Reduktion der Druckstoßbelastung. Neben den hydraulischen Anforderungen ist für die Wahl der Linienführung auf geotechnische und geohydraulische Randbedingungen besonderes Augenmerk zu legen. Zur Optimierung der Anlagenteile werden felsmechanische Großversuche kombiniert mit Laborversuchen ausgeführt. Während der Baudurchführung werden die Annahmen verifiziert. Anhand von Messergebnissen aus den Versuchen im Zug der Inbetriebnahme kann auf das mitwirkende Tragverhalten des Gebirges rückgeschlossen werden. Für das in Ausführung befindliche Pumpspeicherkraftwerk (PSW) Limberg II (Erweiterung Oberstufe KWG Kaprun) wurde eine Optimierung des Wasserschlosses durchgeführt. Dies wurde mit einer in dem Druckstollen integrierten “durchflossenen Unterkammer” sowie einem in geometrischer Verlängerung zum Schrägschacht ausgeführten Steigschacht zur Oberwasserkammer neutralisiert. Neben der hydraulischen Optimierung erfordert die konstruktive Gestaltung mit Betonauskleidung, Stahlpanzerung und einem an die geotechnischen Verhältnisse angepassten Injektionskonzept ein hohes Maß an Aufmerksamkeit der Ausführenden. Ausgehend von den hydraulischen Untersuchungen, der Bemessung und den geotechnischen Randbedingungen wird das Gesamtkonzept des Triebwasserwegs dargestellt.
Alcohol misuse, gender and depressive symptoms in community‐dwelling seniors
Authors: St. John Philip D. , Montgomery Patrick R. , Tyas Suzanne L.
Published: October 2008

Objectives

Alcohol misuse in seniors has been studied in clinical samples and in small communities, but relatively few studies are population‐based. Objectives are: (1) to describe the characteristics of seniors who score 1 or more on the CAGE (Cut down; Annoyed; Guilty; Eye‐opener) questionnaire of alcohol problems; (2) to determine if depressive symptoms are associated with alcohol misuse after accounting for other factors.

Methods

Cross‐sectional study of community‐dwelling older people (65+ years) sampled from a representative population registry in Manitoba, Canada. Participants were initially interviewed in 1991–1992 and reinterviewed in 1996–1997. Data from Time 2 were used; 1,028 persons were included in the analyses. Sociodemographic characteristics, the CAGE questionnaire, Activities of Daily Living (ADLs) and instrumental ADLs (IADLs), the Center for Epidemiologic Studies—Depression (CES‐D) scale and the Mini‐Mental State Examination (MMSE) were assessed by trained interviewers.

Results

Males were more likely to score positive on the CAGE questionnaire. After adjusting for gender, age, and education, there was a strong association between depressive symptoms and alcohol misuse. Poor self‐rated health and impairments in IADLs were also associated with alcohol misuse.

Conclusions

Male gender, depressive symptoms, and poor functional status were associated with alcohol misuse in this population‐based study. Attention to depressive symptoms and functional status may be important in the care of seniors with alcohol misuse. Alternatively, physicians should enquire about alcohol use in seniors with functional impairment or depressive symptoms. Copyright © 2008 John Wiley & Sons, Ltd.
Factors controlling the acid‐neutralizing capacity of Japanese cedar forest watersheds in stands of various ages and topographic characteristics
Authors: Fukushima Keitaro , Tokuchi Naoko
Published: October 2008

Acid‐neutralizing capacity (ANC) is an important index for streamwater acidification caused by external factors (i.e. chronic acid deposition) and internal factors such as soil acidification due to nitrification. In this study, the influence of forest clear‐cutting and subsequent regrowth on internal acidification was investigated in central Japan, where stream pH (near 7·0) and ANC (above 0·1 meq L−1) are high. pH, the concentrations of major cations (Na+, K+, Mg2+ and Ca2+), major anions (NO3−, Cl− and SO42−) and dissolved silica (Si), and ANC were measured in 33 watersheds of various stand ages, during 2002 to 2004. Only NO3− concentration decreased with stand age, whereas pH, ANC, and concentrations of the sum of base cations (BC) and Si were negatively correlated with the minimum elevation of the watershed. The correlation between the BC/Si ratio and minimum elevation suggested that factors contributing to acid neutralization changed at 1100 m above sea level. In watersheds at lower elevations (⩽1100 m), the relatively high contribution of soil water with longer soil contact times should result in higher ANC, and cation exchange reactions should be the dominant process for acid neutralization due to deposition of colluvial soils on the lower slope. In contrast, in higher‐elevation watersheds (≥1100 m), weathered residual soils are thin and the small contribution of deeper groundwater results in lower ANC. These results suggest that the local acid sensitivity is determined by the hydrological and geomorphologic factors generated by steep topography. Copyright © 2008 John Wiley & Sons, Ltd.
Murine pneumotropic virus chimeric Her2/neu virus‐like particles as prophylactic and therapeutic vaccines against Her2/neu expressing tumors
Authors: Andreasson Kalle , Tegerstedt Karin , Eriksson Mathilda , Curcio Claudia , Cavallo Federica , Forni Guido , Dalianis Tina , Ramqvist Torbjörn
Published: October 2008

Virus‐like particles (VLPs) have increasingly attracted attention as DNA‐free and safe antigen carriers in tumor immunotherapy, requiring only minute amounts of antigens. Previously, we have immunized with murine polyomavirus (MPyV) VLPs carrying human Her2/neu and prevented the outgrowth of a human Her2/neu expressing tumor in a transplantable tumor model as well as outgrowth of spontaneous rat Her2/neu carcinomas in BALB‐neuT mice. Here, we examine if prophylactic and therapeutic protection could be obtained with murine pneumotropic virus (MPtV) VLPs, and study the cross‐reactivity between human and rat Her2/neu. VLPs from MPyV and MPtV carrying human or rat Her2/neu were tested in two transplantable tumor models against a human Her2/neu positive (D2F2/E2) and a rat Her2/neu positive tumor cell line (TUBO). Rat Her2/neu‐VLPs were also tested in BALB‐neuT mice. Her2/neu‐MPtVLPs were as efficient as prophylactic vaccines against D2F2/E2 and TUBO as those from MPyV. Homologous Her2/neu was better than heterologous, i.e. human Her2/neu‐VLPs were better than rat Her2/neu‐VLPs against D2F2/E2 and vice versa. Moreover, therapeutic immunization with human Her2/neu‐VLPs together with CpG given up to 6 days after challenge protected against D2F2/E2. In BALB‐neuT mice, rat Her2/neu‐VLPs were less efficient than human Her2/neu‐VLPs used in our previous study, implying that protection seen in that study was partly due to the use of human rather than rat Her2/neu. In conclusion, Her2/neu‐MPtVLPs are effective both as prophylactic and therapeutic tumor vaccines. Homologous Her2/neu‐VLPs are superior to heterologous in transplantable tumor models, while the opposite is true in BALB‐neuT mice. © 2008 Wiley‐Liss, Inc.
Hydrogels used for cell‐based drug delivery
Authors: Schmidt John J. , Rowley Jon , Kong Hyun Joon
Published: October 2008

Stem cells, progenitor cells, and lineage‐committed cells are being considered as a new generation of drug depots for the sustained release of therapeutic biomolecules. Hydrogels are often used in conjunction with the therapeutic secreting cells to provide a physical barrier to protect the cells from hostile extrinsic factors. Although the hydrogels significantly improve the therapeutic efficacy of transplanted cells, there have been no successful products commercialized based on these technologies. Recently, biomaterials are increasingly designed to provide cells with both a physical barrier and an extracellular matrix to further improve the secretion of therapeutic proteins from cells. This review will discuss (1) the cell encapsulation process, (2) the immunogenicity of the encapsulating hydrogel, (3) the transport properties of the hydrogel, (4) the hydrogel mechanical properties, and will propose new strategies to improve the hydrogel and cell interaction for successful cell‐based drug delivery strategies. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Porous tantalum in hip and knee reconstructive surgery
Authors: Patil Nilesh , Lee Kevin , Goodman Stuart B.
Published: October 2008

Conventional porous‐coated joint prostheses used in hip and knee reconstruction have demonstrated good clinical results, however, these implants possess some inherent shortcomings such as low volumetric porosity, suboptimal frictional characteristics, and higher modulus of elasticity relative to that of bone. Porous tantalum, a novel porous biomaterial was developed to address these limitations. Extensive laboratory studies have revealed that porous tantalum has physical, mechanical and tissue in growth properties that makes it a potentially improved biomaterial particularly in complex joint reconstructions. Porous tantalum is a highly porous biomaterial with good biocompatibility, excellent corrosion resistance, and high coefficient of friction. The short term clinical results of porous tantalum in primary hip, revision hip, and knee reconstructive surgery are encouraging but further studies will be needed to determine whether the theoretical advantages of porous tantalum can provide long term biological fixation and stability. This review presents the biomaterial properties and clinical results of porous tantalum devices in hip and knee reconstructive surgeries. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Observations on an in‐vivo failure of a titanium dental implant/abutment screw system: A case report
Authors: Manda Marianthi G. , Psyllaki Pandora P. , Tsipas Dimitrios N. , Koidis Petros T.
Published: October 2008

Titanium and its alloys are widely used in prosthetic dentistry, due to their biocompatibility, excellent mechanical and anti‐corrosion behavior. However, delayed fracture of dental prosthetics is frequently encountered. Mechanisms leading to fracture are not generic but are strongly related to the particular environmental (quality of biological fluids) and mechanical loading conditions (mastication habits, presence of prosthetic metallic/ceramic components) in the patients' oral cavity. In this study, a commercially pure titanium implant‐screw system has failed after 15 years of operation in the oral cavity of an old female. The system was retrieved in three pieces: the upper part of the implant, part of the abutment screw, and the apical part of the implant to which a part of the screw was embedded. This is considered as a rare case, where the whole dental assembly was retrieved after fracture allowing the extensive fractographic analysis of the conjugate pieces and the establishment of a thorough in‐vivo failure scenario. Scanning electron microscopy observations performed on all three retrieved parts indicated a synergistic effect of distinct mechanisms, which led to total failure under extrinsic common fatigue loading. The principal mechanism was the propagation of a main crack, which was previously initiated in the body of the implant and affected by a wedging mechanism due to Ca/P aggregates developed within the crack. Because of the strong fixation between the implant and the abutment screw, this main crack was transferred to the latter causing eventually total failure of the assembly. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
The new adhesion prophylaxis membrane A‐part®—From in vitro testing to first in vivo results
Authors: Jaenigen Bernd Martin , Weis Christine , Odermatt Erich Kurt , Hopt Ulrich Theodor , Obermaier Robert
Published: October 2008

Introduction: Formation of postoperative intra‐abdominal adhesions is a severe problem in surgery. Apart from standard surgical procedures, a variety of different substances is available to prevent adhesions, but no universal method has been developed so far. A membrane consisting of polyvinyl alcohol (PVA) and carboxymethylcellulose (CMC) has been demonstrated to be antiadhesive. Here, the in vitro testing and first in vivo results in a rabbit sidewall model are reported. Materials and Methods: A‐part® membrane contains a PVA/CMC mixture in a thickness of 40 μm. The composition, dissolution, tensile strength, and elasticity were examined to characterize the membrane in vitro. Experiments in vivo were carried out using a ‘rabbit sidewall model’ in which a standardized peritoneal trauma was covered with a 5 × 6 cm A‐part® membrane. Adhesion formation in A‐part®‐treated animals was compared with that in Adept® (15 mL/kg body weight) and untreated controls. Results: An 80/20 PVA/CMC mixture forms a stable, elastic, transparent membrane, which can easily be placed intraoperatively. The dissolution shows a half‐life of about 2 weeks [day 15: (45.1 ± 4.9)% SD], which affords good adhesion protection during the initial critical phase of adhesion formation. In wet conditions, the membrane follows abdominal movements without tearing (tensile strength 5.0 ± 4.2 N/cm SD; elasticity 29.5%). In a rabbit sidewall model, A‐part® membrane significantly reduced adhesion development by (83.1 ± 31.5)% SD compared with the control and the Adept group (p < 0.001). Conclusion: The properties of the A‐part® membrane suggest that it may be useful as an antiadhesive in surgery. A‐part® is effective in invivo testing as determined in a rabbit sidewall model. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Long‐term in vitro stability assessment of polycarbonate urethane micro catheters: Resistance to oxidation and stress cracking
Authors: Chandy Thomas , Van Hee Justin , Nettekoven William , Johnson Jay
Published: October 2008

Micro catheter tubes were prepared from poly (carbonate urethane) (PCU, Bionate) and poly (ether urethane) (PEU, Pellethane) and their stability was investigated in vitro under applied strain. The tubes were stretched to an elongation of 200% or 300% and exposed to hydrogen peroxide/cobalt chloride (H2O2/CoCl2) solution for specific periods of time (up to 10 months). The samples were observed for surface degradation via scanning electron microscopy, the bulk erosion via the weight difference, and the changes in molecular weight using gel permeation chromatography. The 200% and 300% strained Pellethane tubes kept in H2O2/CoCl2 solution for 1 month showed substantial cracking of the surface layer with pitting and have degraded completely within 45 to 60 days (from scanning electron microscopy). Bionate tubes treated in similar conditions for a 10‐month period exhibited minute surface erosion in the depth of 0.25–1 μm and showed no evidence of major cracking or pitting. The gel permeation chromatography analysis of 300% strained catheters indicated that the degradation of Bionate tubes was negligible. The 10‐month samples had shown ∼18% reduction in their number average molecular weight (Mn) and about 8% reduction in weight average molecular weight (Mw). The Pellethane studied in similar conditions had indicated ∼72% reduction in Mn and about ∼50% reduction in Mw for 1 month. Overall, the Bionate underwent less degradation and the degradated surface layer was much thinner than Pellethane. These in vitro results are valuable in designing the in vivo studies for using Bionate tube as a long‐term implant. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
The effect of a self‐assembling peptide nanofiber scaffold (peptide) when used as a wound dressing for the treatment of deep second degree burns in rats
Authors: Meng Hui , Chen Liyan , Ye Zhaoyang , Wang Songtao , Zhao Xiaojun
Published: October 2008

RADARADARADARADA (RADA16‐I) peptide, consisting of 16 alternating hydrophobic and hydrophilic (also alternating negative and positive charges) amino acids, forms extremely stable β‐pleated sheet structure and then self‐assembles into nanofibers to produce high‐order interwoven nanofiber scaffold hydrogel. To investigate its therapeutic effects, a burn model of partial thickness‐deep dermal injury (the deep second degree burns) was performed at the dorsal skin of female Sprague‐Dawley rats with an electrical scalding machine. The wounds treated with either RADA16‐I or control materials were carefully examined at morphological, histological and cellular levels. We found that RADA16‐I can advance the time of eschar appearance and the time of eschar disappearance both by 3–5 days, and speed up wound contraction by 20–30% compared with contrast groups (chitosan, poly(DL)‐lactic acid (PDLA), collagen I and the blank) without obvious edema. Immunohistochemical studies showed that both FGF and EGF were obviously expressed in nascent tissue such as epidermis and glands when wounds were treated with the RADA16‐I after injury. When peptide stock solution was diluted from 10 to 0.17 mg/mL, atomic force microscopy (AFM) observation showed that the shape of peptide nanofibers changed from the globular‐pieces‐clustered filaments with 4.8 ± 0.38 nm in height, 61.6 ± 6.10 nm in width and 708 ± 80.2 nm in length, to general filaments with 1.4 ± 0.36 nm, 17.5 ± 1.13 nm and 1108 ± 184 nm. The nanofiber surface porosity gradually decreased from 49–70% to 12–28%. These characteristics contribute to wound healing by offering an “ideal dressing” moist healing microenvironment and a nanofiber 3D scaffold. These results suggest that the self‐assembling peptide might be a promising wound dressing with being simple, effective, and affordable. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Control of surface free energy in titanium doped phosphate based glasses by co‐doping with zinc
Authors: Neel Ensanya Ali Abou , O'Dell Luke Austin , Chrzanowski Wojciech , Smith Mark Edmund , Knowles Jonathan Campbell
Published: October 2008

To significantly improve the biocompatibility of titanium doped phosphate based glasses, codoping with zinc has been attempted. This study investigated the effect of doping a quaternary 15Na2O:30CaO:5TiO2:50P2O5 glass with zinc oxide (1, 3, and 5 mol %) on bulk, structural, surface, and biological properties; the results were compared with glasses free from ZnO and/or TiO2. ZnO as adjunct to TiO2 was effective in changing density, interchain bond forces, degradation behavior, and ions released from the degrading glasses. Incorporation of both TiO2 and ZnO in T5Z1, T5Z3, and T5Z5 glasses reduced the level of Zn2+ release by two to three orders of magnitude compared with glasses containing ZnO only (Z5). 31P NMR results for T5Z1, T5Z3, and T5Z5 glasses showed the presence of Q3 species suggesting that the TiO2 is acting as a network former, and the phosphate network becomes slightly more connected with increasing ZnO incorporation. Regardless of their relative lower hydrophilicity and surface reactivity compared with the control glass free from TiO2 and ZnO (T0Z0), these glasses have significantly higher surface reactivity compared with Thermanox®. This has been also reflected in the maintenance of >98% viable Osteoblasts, proliferation rate, and expression level of osteoblastic marker genes in a comparable manner to Thermanox® and T5 glasses, particularly T5Z1 and T5Z3 glasses. However, T0Z0 and Z5 glasses showed significantly reduced viability compared to Thermanox®. Therefore, it can be concluded that ZnO doped titanium phosphate glasses, T5Z1 and T5Z3 in particular, can be promising substrates for bone tissue engineering applications. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Color Doppler sonography of intrahepatic vascular shunts
Authors: Bertolotto Michele , Martinoli Carlo , Migaleddu Vincenzo , Cernic Stefano , Zappetti Roberta
Published: October 2008

Purpose.

To illustrate the sonographic and Doppler features of the different types of intrahepatic vascular shunts.

Methods.

Patients presenting in our department with intrahepatic vascular shunts with healthy livers or with a variety of liver pathologies underwent color Doppler interrogation and spectral analysis.

Results.

Intrahepatic vascular shunts may involve all liver vessels. Arterioportal and arteriosystemic venous connections can be recognized in normal and cirrhotic livers, following trauma, within tumors, and within nontumoral arteriovenous malformations. Portosystemic intrahepatic venous shunts are categorized into 4 morphologic types. Systemic‐to‐systemic shunts are more often recognized in patients with chronic hepatic venous congestion or with Budd‐Chiari syndrome. Portal‐to‐portal intrahepatic venous shunts are rare, with few cases described.

Conclusion.

In general, all the liver vessels can be associated with formation of arterioportal, arteriosystemic, and portosystemic venous shunts and, rarely, systemic venous shunts and portal‐to‐portal communications. Sonography allows characterization of the different intrahepatic shunts. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Two‐probe electrical measurements in transmission electron microscopes—Behavioral control of tungsten microwires
Authors: Costa Pedro M.F.J. , Fang Xiaosheng , Wang Shiliang , He Yuehui , Bando Yoshio , Mitome Masanori , Zou Jin , Huang Han , Golberg Dmitri
Published: October 2008

Tungsten microwires have been manipulated and electrically probed inside a transmission electron microscope. Using Au electrodes, the current–voltage characteristics of the W structures were extracted. These showed highly variable behaviors dependent on various factors, the most important of these being orientation and stiffness of the contact. Careful control of loading force and Au–W contact angle enabled a considerable degree of behavior tailoring from nonlinear to Ohmic responses. Microsc. Res. Tech., 2009. © 2008 Wiley‐Liss, Inc.
Synergistic neuroprotective effect via simian lentiviral vector‐mediated simultaneous gene transfer of human pigment epithelium‐derived factor and human fibroblast growth factor‐2 in rodent models of retinitis pigmentosa
Authors: Miyazaki Masanori , Ikeda Yasuhiro , Yonemitsu Yoshikazu , Goto Yoshinobu , Kohno Ri‐ichiro , Murakami Yusuke , Inoue Makoto , Ueda Yasuji , Hasegawa Mamoru , Tobimatsu Shozo , Sueishi Katsuo , Ishibashi Tatsuro
Published: October 2008

Background

We previously demonstrated that a new lentiviral vector derived from nonpathogenic simian immunodeficiency virus (SIVagm) was efficient and safe for long‐lasting retinal gene transfer, and that it provided the significant therapeutic effect of expressing human pigment epithelium‐derived factor (hPEDF) in Royal College of Surgeons (RCS) rats. In the present study, to obtain a more pronounced outcome, we assessed the potential synergistic effect of the simultaneous gene transfer of hPEDF and human fibroblast growth factor‐2 (hFGF‐2) by improved third‐generation SIV on RCS rats and retinal degeneration slow (rds) mice, because the former targets the primary neurons, including photoreceptor cells (PCs), whereas the latter is effective for targeting secondary neural cells, including Muller cells.

Methods

Vector solution (SIV‐hPEDF, SIV‐hFGF‐2, a 1 : 1 mixture of SIV‐hPEDF and SIV‐hFGF‐2, or SIV‐enhanced green fluorescent protein) was injected into the peripheral subretinal space of 3‐week‐old RCS rats or rds mice. Histopathological and electroretinographic assessments were made at several points after gene transfer.

Results

Administration of SIV‐hPEDF or SIV‐hFGF‐2 significantly delayed the histological PC degeneration and electrical deficit in RCS rats, and these delays were synergistically and significantly pronounced by SIV‐hPEDF + SIV‐hFGF‐2 (1 : 1 mixture). In rds mice, functional therapeutic effects were observed even by SIV‐PEDF, or SIV‐FGF‐2 alone and, moreover, both SIV‐PEDF and SIV‐FGF‐2 showed higher therapeutic effects.

Conclusions

These synergistic rescues of retinitis pigmentosa (RP) model animals are the ‘proof concept’ that the ‘dual’ expression of hPEDF and hFGF‐2 dramatically improved therapeutic efficacy by keeping lower titers. This strategy may contribute to safer and more effective gene therapy for RP. Copyright © 2008 John Wiley & Sons, Ltd.
Contractors and connectors of graph algebras
Authors: Lovász László , Szegedy Balázs
Published: October 2008

We study generalizations of the “contraction‐deletion” relation of the Tutte polynomial, and other similar simple operations, to other graph parameters. The question can be set in the framework of graph algebras introduced by Freedman at al [Reflection positivity, rank connectivity, and homomorphisms of graphs, J. Amer. Math. Soc. 20 (2007), 37–51.] Graph algebras are defined by a graph parameter, and they were introduced in order to study and characterize homomorphism functions. We prove that for homomorphism functions, these graph algebras have special elements called “contractors” and “connectors”. This gives a new characterization of homomorphism functions. © 2008 Wiley Periodicals, Inc. J Graph Theory 60: 11–30, 2009
Small‐scale farmer participation in new agri‐food supply chains: Case of the supermarket supply chain for fruit and vegetables in Honduras
Authors: Blandon Jose , Henson Spencer , Cranfield John
Published: October 2008

This paper explores the role of transaction costs and collective action in shaping small‐scale farmer participation in the fresh fruit and vegetable (FFV) supply chain to supermarkets (SSC) in Honduras. Transaction costs and collective action are found to be significant in determining farmer participation in the SSC. Contrary to the findings of other studies, human capital and farm characteristic variables are not significant, suggesting that small‐scale farmers can be included in new supply chains under certain conditions, especially if incentives to farmers, trust‐based relationships between buyers and sellers, risk reduction practices and new forms of collective action are put in place. Copyright © 2008 John Wiley & Sons, Ltd.
How does economic empowerment affect women's risk of intimate partner violence in low and middle income countries? A systematic review of published evidence
Authors: Vyas Seema , Watts Charlotte
Published: October 2008

Objectives

To identify whether individual and household economic empowerment is associated with lower intimate partner violence in low and middle income country settings.

Methods

Systematic PubMed and internet searches.

Results

Published data from 41 sites were reviewed. Household assets and women's higher education were generally protective. Evidence about women's involvement in income generation and experience of past year violence was mixed, with five finding a protective association and six documenting a risk association.

Conclusion

At an individual and household level, economic development and poverty reduction may have protective impacts on IPV. Context specific factors influence whether financial autonomy is protective or associated with increased risk. Copyright © 2008 John Wiley & Sons, Ltd.

This article was published online on 6 October 2008. Errors were subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected [17 April 2009].
Why do the poor pay more? Exploring the poverty penalty concept
Authors: Mendoza Ronald U.
Published: October 2008

The poverty penalty refers to the relatively higher cost shouldered by the poor, when compared to the non‐poor, in their participation in certain markets. By trying to further develop this concept, this paper clarifies some of the subtle and more direct ways through which the poor could be marginalised in the market system. A brief review of the business and economics literature suggests that there are different possible causes behind various forms of the poverty penalty, and hence distinct ways to address them, depending on its form, the nature of the market under analysis, the specific country context, the characteristics of the poor themselves and the prevalence of market failures among other factors. Copyright © 2008 John Wiley & Sons, Ltd.
Oxidoreductase activities of polyclonal IgGs from the sera of Wistar rats are better activated by combinations of different metal ions
Authors: Tolmacheva Anna S. , Zaksas Nataliya P. , Buneva Valentina N. , Vasilenko Nataliya L. , Nevinsky Georgy A.
Published: October 2008

It was shown that IgGs purified from the sera of healthy Wistar rats contain several different bound Me2+ ions and oxidize 3,3′‐diaminobenzidine through a H2O2‐dependent peroxidase and H2O2‐independent oxidoreductase activity. IgGs have lost these activities after removing the internal metal ions by dialysis against EDTA. External Cu2+ or Fe2+ activated significantly both activities of non‐dialysed IgGs containing different internal metals (Fe ≥ Pb ≥ Zn ≥ Cu ≥ Al ≥ Ca ≥ Ni ≥ Mn > Co ≥ Mg) showing pronounced biphasic dependencies corresponding to ∼0.1–2 and ∼2–5 mM of Me2+, while the curves for Mn2+ were nearly linear. Cu2+ alone significantly stimulated both the peroxidase and oxidoreductase activities of dialysed IgGs only at high concentration (≥ 2 mM), while Mn2+ weakly activated peroxidase activity at concentration >3 mM but was active in the oxidoreductase oxidation at a low concentration (<1 mM). Fe2+‐dependent peroxidase activity of dialysed IgGs was observed at 0.1–5 mM, but Fe2+ was completely inactive in the oxidoreductase reaction. Mg2+, Ca2+, Zn2+, Al2+ and especially Co2+ and Ni2+ were not able to activate dialysed IgGs, but slightly activated non‐dialysed IgGs. The use of the combinations of Cu2+ + Mn2+, Cu2+ + Zn2+, Fe2+ + Mn2+, Fe2+ + Zn2+ led to a conversion of the biphasic curves to hyperbolic ones and in parallel to a significant increase in the activity as compared with Cu2+, Fe2+ or Mn2+ ions taken separately; the rates of the oxidation reactions, catalysed by non‐dialysed and dialysed IgGs, became comparable. Mg2+, Co2+ and Ni2+ markedly activated the Cu2+‐dependent oxidation reactions catalysed by dialysed IgGs, while Ca2+ inhibited these reactions. A possible role of the second metal in the oxidation reactions is discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Protein profile and malt activity during sorghum germination
Authors: Correia Isabel , Nunes Alexandra , Barros António S , Delgadillo Ivonne
Published: October 2008

BACKGROUND: The effect of germination time on major sorghum macromolecules was followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy. Sorghum flour was also incubated with sorghum malt to evaluate amylase and protease activities.

RESULTS: The SDS‐PAGE results showed that levels of high‐molecular‐weight aggregates, β monomer and γ and α monomers increased by 120.5, 20.3 and 12.7% respectively during the first few days of germination. This behaviour shows the enhancement of prolamin extractability and concentration in sorghum as a result of starch degradation. After the third day, proteins suffered degradation by intrinsic proteases. FTIR spectroscopy showed a gradual decrease in lipid and protein levels and starch structural changes during the germination period. These modifications are due to intrinsic lipases, proteases and amylases. Sorghum flour was incubated with different malt samples resulting from 0–7 days of germination. It was found that a 5 day malt led to a sixfold increase in carbohydrate digestibility and a fourfold increase in free amino acid content.

CONCLUSION: A 5 day sorghum malt is the best inoculum for porridge preparation, representing an inexpensive, effortless and culturally acceptable way to prepare weaning foods at domestic and industrial levels. Copyright © 2008 Society of Chemical Industry