bluuebunny/crossref_metadata_2025 huggingface dataset:
Those Who Never Make It and the Suffering of Those Left Behind: The Fate of Honduran Missing Migrants and their Families
Authors: Kirchbichler Elisabeth
Published: February 2011

Every day Hondurans leave their country to migrate to the U.S undocumented, risking their lives on the journey. Some reach the U.S.; many are deported after being picked up by either the Mexican or the U.S. authorities. This article focuses on a little acknowledged third group, those who go missing on the trip, and their families, who are left worrying and wondering what has happened. It looks at the cases of four missing migrants in the area of El Progreso, in north-western Honduras, considering what is at the root of their decision to migrate, what is suspected to have happened to them, how the situation is affecting their families and what the latter do to find them. It also examines the support they receive. These relatives are affiliated with a self-help committee founded with the aim of finding out what has happened. In the process of doing so, the committee has not only been able to locate some of those missing and put the topic on the public and political agenda in Honduras, its most active members have gained a previously unknown confidence in their ability to take the outcome of their lives into their own hands.
Stabilization analysis and implementation for MIMO NCS with time‐varying delays
Authors: Xia Yuanqing , Liu Xiaopeng , Liu Guo‐Ping , Rees David
Published: January 2011

This paper is concerned with the design of output feedback controllers for a class of maximum input maximum output networked control systems (NCSs). In view of NCSs with many independent sensors and actuators, a discrete‐time model with multiple time‐varying delays is proposed. By constructing a novel Lyapunov–Krasovskii functional, a new less conservative stability criterion is developed in terms of linear matrix inequality. On the basis of the obtained stability condition, a static output feedback controller can be designed by applying an iterative algorithm. Both simulation and practical experiment results are given to show the effectiveness of the proposed method. Copyright © 2011 John Wiley & Sons, Ltd.
Fatigue Damage Evolution in Ultrafine‐Grained Interstitial‐Free Steel
Authors: Niendorf Thomas , Canadinc Demircan , Maier Hans Jürgen
Published: January 2011

The current work presents the crack propagation behavior in ultrafine‐grained (UFG) interstitial‐free (IF) steel, and in particular, focuses on the damage evolution in UFG IF steel under cyclic loading. The current results indicate that equal‐channel angular pressing (ECAP) has a major influence on the cyclic deformation response of the UFG IF steel, such that the failure and the crack path depend on the inclination plane during ECAP. Furthermore, the UFG IF steel demonstrates significant notch sensitivity in comparison to its coarse‐grained counterpart. This is attributed to the ultrafine grains with a large volume fraction of high‐angle grain boundaries, where glide of dislocations is hindered and the resulting internal stresses increase the stress concentration further in the presence of a pre‐existing notch.
Mapping Lattice Spacing and Composition in Biological Materials by Means of Microbeam X‐Ray Diffraction
Authors: Paris Oskar , Aichmayer Barbara , Al‐Sawalmih Ali , Li Chenghao , Siegel Stefan , Fratzl Peter
Published: January 2011

Many biological materials and in particular biomineralized tissues exhibit structural and compositional gradients at several length scales. Nanostructural features varying at the micrometer scale can be imaged by employing synchrotron radiation based small‐ and wide‐angle X‐ray scattering combined with microbeam scanning. In particular, the lattice distortions caused by a substituted atoms within a crystal structure can be mapped by evaluating the corresponding shifts of Bragg reflections. As we demonstrate here by reviewing three examples of mineralized biological tissues, this approach delivers valuable complementary information to chemical imaging (e.g., X‐ray fluorescence imaging). Specifically, we show that strontium is incorporated in the hydroxyapatite crystal structure of human bone after osteoporosis treatment with Sr ranelate. Moreover, we discuss how local magnesium gradients within two different calcite phases in the tip of the sea urchin tooth may relate to the excellent mechanical properties and the self sharpening ability of this exceptional grinding tool. Finally, we show how this method allows drawing conclusions about the stability of the amorphous calcium carbonate in the cuticle of the American Lobster by determining the magnesium concentration after crystallization induced by an in situ heat treatment.
Large‐Scale Synthesis of Bi‐layer Graphene in Strongly Coupled Stacking Order
Authors: Luo Zhiqiang , Yu Ting , Shang Jingzhi , Wang Yingying , Lim Sanhua , Liu Lei , Gurzadyan Gagik G. , Shen Zexiang , Lin Jianyi
Published: January 2011

Large‐scale synthesis of single‐layer graphene (SLG) by chemical vapor deposition (CVD) has received a lot of attention recently. However, CVD synthesis of AB stacked bi‐layer graphene (BLG) is still challenging. Here, we report synthesis of BLG homogeneously at large scale by thermal CVD. The 2D Raman band of CVD BLG splits into four components, suggesting splitting of electronic bands due to strong interlayer coupling. The splitting of electronic bands in CVD BLG is further evidenced by the study of near infrared absorption and carrier dynamics are probed by transient absorption spectroscopy. UV photoelectron spectroscopy invesigation also indiates CVD BLG possesses different electronic structures to those of CVD SLG. The growth mechanism of BLG is found to be related to catalytic activity of the copper (Cu) surface, which is determined by the purity of Cu foils employed in the CVD process. Our work shows that strongly coupled or even AB stacked BLG can be grown on Cu foils at large scale, which is of particular importance for device applications based on their split electronic bands.
Thermoforming of Film‐Based Biomedical Microdevices
Authors: Truckenmüller Roman , Giselbrecht Stefan , Rivron Nicolas , Gottwald Eric , Saile Volker , van den Berg Albert , Wessling Matthias , van Blitterswijk Clemens
Published: January 2011

For roughly ten years now, a new class of polymer micromoulding processes comes more and more into the focus both of the microtechnology and the biomedical engineering community. These processes can be subsumed under the term “microthermoforming”. In microthermoforming, thin polymer films are heated to a softened, but still solid state and formed to thin‐walled microdevices by three‐dimensional stretching. The high material coherence during forming is in contrast to common polymer microreplication processes where the material is processed in a liquid or flowing state. It enables the preservation of premodifications of the film material. In this progress report, we review the still young state of the art of microthermoforming technology as well as its first applications. So far, the applications are mainly in the biomedical field. They benefit from the fact that thermoformed microdevices have unique properties resulting from their special, unusual morphology. The focus of this paper is on the impact of the new class of micromoulding processes and the processed film materials on the characteristics of the moulded microdevices and on their applications.
Superaligned Carbon Nanotube Arrays, Films, and Yarns: A Road to Applications
Authors: Jiang Kaili , Wang Jiaping , Li Qunqing , Liu Liang , Liu Changhong , Fan Shoushan
Published: January 2011

A superaligned carbon nanotube (CNT) array is a special kind of vertically aligned CNT array with the capability of being converted into continuous films and yarns. The as‐produced CNT films are transparent and highly conductive, with aligned CNTs parallel to the direction of drawing. After passing through volatile solutions or being twisted, CNT films can be further condensed into shrunk yarns. These shrunk yarns possess high tensile strengths and Young’s moduli, and are good conductors. Many applications of CNT films and shrunk yarns have been demonstrated, such as TEM grids, loudspeakers, touch screens, etc.
Disease Stage Characterization of Hepatorenal Fibrocystic Pathology in the PCK Rat Model of ARPKD
Authors: Mason Stephen B. , Liang Yun , Sinders Rachel M. , Miller Caroline A. , Eggleston‐Gulyas Tracy , Crisler‐Roberts Robin , Harris Peter C. , Gattone Vincent H.
Published: January 2011

Renal cysts in a 25 week male PCK kidney. See Mason et al., on page 1279, in this issue.
Protective Effect of Resveratrol on Acute Lung Injury Induced by Lipopolysaccharide in Mice
Authors: Cao Quan , Jing Changwen , Tang Xinyi , Yin Ye , Han Xiao , Wu Wenxi
Published: January 2011

Resveratrol, a phytoalexin found in a range of plant products, may exert a variety of pharmacological activities. In this study, we investigated the effect of resveratrol on acute lung injury (ALI) induced by lipopolysaccharide (LPS) in vivo, and we found that the pretreatment with resveratrol can effectively protect mice against LPS‐induced ALI. Mice were pretreated with 1 mg/kg resveratrol for 3 days before challenging with a dose of 15 mg/kg LPS. The histological result showed that resveratrol can suppress the edema, inflammatory cell infiltration, and alveolar structure damage of lungs in ALI mice, and a decrease in the lung W/D ratio was also observed in mice with resveratrol pretreatment. Additionally, resveratrol markedly decreased the production of inflammatory cytokines, including IL‐1β and MIP‐1α and prevented the release of nitric oxide (NO) through inhibiting the expression of inducible NO synthase in lung tissues. Furthermore, the pretreatment with resveratrol suppressed the nuclear translocation of NF‐κB in lung tissues, which may be partly responsible for its effect on the ALI. In conclusion, the results presented here may suggest resveratrol as a potential therapeutic agent for treating ALI in the future. Anat Rec, , 2011. © 2011 Wiley‐Liss, Inc.
Age‐Related Changes of the Oligodendrocytes in Rat Subcortical White Matter
Authors: Chen Lin , Lu Wei , Yang Zhengwei , Yang Shu , Li Chen , Shi Xiaoyan , Tang Yong
Published: January 2011

The age‐related changes, of the oligodendrocytes in rat subcortical white matter, were investigated in this study. The oligodendrocytes in subcortical white matter were labeled with anti‐2′,3′‐cyclic nucleotide 3′‐phosphodiesterase antibody (anti‐CNPase antibody, a specific marker of oligodendrocytes). The total number of CNPase+ cells was estimated with an unbiased stereological technique, the optical fractionator. In this study, we found that the total number of CNPase+ cells in the young male rats and aged male rats was 14.4 ± 1.2 × 106 and 9.0 ± 1.0 × 106, respectively. The total number of the CNPase+ cells in the subcortical white matter of aged rats was significantly decreased by 37.5% when compared to young male rats. This study demonstrated that there was an aged‐related decrease of the oligodendrocytes in subcortical white matter. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Ultrastructural and Immunohistochemical Analysis of Intestinal Myofibroblasts During the Early Organogenesis of the Human Small Intestine
Authors: Artells Rosa , Navarro Alfons , Diaz Tània , Monzó Mariano
Published: January 2011

Intestinal myofibroblasts (IMFs), also known as pericryptal fibroblasts, are found at the basement membrane of the intestinal epithelium. They are characterized by well‐developed endoplasmic reticulum, cytoplasmic fibers, and fibrous extensions called fibronexi. IMFs have structural features in common both with fibroblasts and smooth cells. Vimentin, desmin, and α‐smooth‐muscle actin (α‐SM) are markers commonly used to discriminate between IMFs and smooth muscle cells. Immunohistochemical studies have shown that, when α‐SM and vimentin are positive in both IMFs and smooth muscle cells, desmin is negative in IMFs but positive in smooth muscle cells. In the adult intestine, IMFs play an important role in various functions, especially in tissue repair and scar formation during wound healing. In the embryonic intestine, however, wound healing does not occur, and to date, no studies have investigated the first appearance and subsequent evolution of IMFs. In this study, we have examined the human small intestine in embryos at 7, 9, and 11 weeks of development by ultrastructural and immunohistochemical analysis to shed light on the formation of IMFs during these early phases of organogenesis. At 7 weeks, the embryonic mesenchymal cells are similar to proto‐myofibroblasts and may be the precursors of the IMFs detected at 9 weeks and more abundantly at 11 weeks by immunohistochemistry. These IMFs seem to mediate information flow between the epithelium and the mesenchyme and thus contribute to the development of the small intestine. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Comparative Morphological Configuration of the Cardiac Nervous System in Lorises and Galagos (Infraorder Lorisiformes, Strepsirrhini, Primates) with Evolutionary Perspective
Authors: Kawashima Tomokazu , Thorington Jr. Richard W.
Published: January 2011

The detailed systematic morphology and comparative anatomy of the autonomic cardiac nervous system (ACNS) with its surrounding structures were examined in 14 sides of 7 Lorisiformes species (lorises and galagos) to consider its evolutionary differences and similarities to others in the primate lineage. Our detailed descriptions clarified that (1) a family‐dependent morphology of the ACNS does not exist although several variations are recognized as common variation in Lorisiformes, (2) the morphology of the ACNS in Lorisiformes is almost consistent regardless of the number of presacral vertebrae and cardiac positions, and (3) the ACNS morphology in Lorisiformes is extremely different from that in New and Old World monkeys, gibbons, and human, specifically in a narrower contribution of the superior cervical ganglion to the spinal cervical nerves, the caudal position and organization of the cervicothoracic ganglion, and the narrower origins of the sympathetic cardiac nerves, although all parasympathetic vagal cardiac branches are consistently present among the primates. Based on these detailed findings, the systematic and evolutionary morphologies of the ACNS are discussed and compared with our previous works. These results suggest the primate ACNS preserves its evolutionary history without modification and specialization by its functional adaptation as seen in the somatic system. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
A dense GNSS meteorological network for observing deep convection in the Amazon
Authors: Adams David K. , Fernandes Rui M. S. , Kursinski E. Robert , Maia Jair M. , Sapucci Luiz F. , Machado Luiz A. T. , Vitorello Icaro , Monico João Francisco Galera , Holub Kirk L. , Gutman Seth I. , Filizola Naziano , Bennett Richard A.
Published: January 2011

A dense Global Navigation Satellite System (GNSS) meteorological network (∼20 stations) in the central Amazon Basin in Brazil is being developed for long‐term studies of deep convection/water vapor interactions and feedback. In this article, the network is described and preliminary results are presented: GNSS‐derived precipitable water vapor is useful for tracking water vapor advection and in identifying convective events and water vapor convergence timescales. Upon network completion (early 2011), 3D water vapor field analyses and participation in the intensive field campaign GPM‐CHUVA will provide unique data sets for initializing, constraining or validating high‐resolution models or refining convective parameterizations. Copyright © 2011 Royal Meteorological Society
The Geoengineering Model Intercomparison Project (GeoMIP)
Authors: Kravitz Ben , Robock Alan , Boucher Olivier , Schmidt Hauke , Taylor Karl E. , Stenchikov Georgiy , Schulz Michael
Published: January 2011

To evaluate the effects of stratospheric geoengineering with sulphate aerosols, we propose standard forcing scenarios to be applied to multiple climate models to compare their results and determine the robustness of their responses. Thus far, different modeling groups have used different forcing scenarios for both global warming and geoengineering, complicating the comparison of results. We recommend four experiments to explore the extent to which geoengineering might offset climate change projected in some of the Climate Model Intercomparison Project 5 experiments. These experiments focus on stratospheric aerosols, but future experiments under this framework may focus on different means of geoengineering. Copyright © 2011 Royal Meteorological Society and Crown copyright
Methodik und Beispiel einer Brückenertüchtigung durch externe Vorspannung
Authors: Alex Jörg , Berlin Manfred
Published: January 2011

Neben dem Brückenneubau gewinnt die Brückenertüchtigung immer mehr an Bedeutung. Die Ursachen hierfür liegen in der Veränderung der Art, der Anzahl und des Fahrverhaltens der Güterverkehrstransportmittel, so dass immer mehr Bestandsbrücken Tragfähigkeitsdefizite aufweisen. Mit Hilfe verschiedener zur Verfügung stehender Verfahren ist eine schnelle, effektive und kostengünstige Steigerung der Trag‐ und Gebrauchsfähigkeit möglich. Die Methodik und die Ausführung solcher Planungen sollen im Folgenden vorgestellt werden.
Grundlagen und Entwicklung von stochastischen Modellen zur Beurteilung der Schädigung von Massivbrücken auf der Grundlage der Ergebnisse von Bauwerksüberprüfungen
Authors: Braml Thomas , Keuser Manfred , Bergmeister Konrad
Published: January 2011

In zwei Beiträgen wird ein auf der Zuverlässigkeitstheorie basierendes probabilistisches Verfahren für eine schnelle Bewertung der Tragfähigkeit eines geschädigten Stahlbetonbrückenbauwerks vorgestellt. Es ersetzt keine statische Nachberechnung, unterstützt jedoch den Bauwerksprüfer noch während der Prüfung gemäß DIN 1076 und lässt eine schnelle Entscheidung über die Art und Weise einer ggf. erforderlichen Nutzungseinschränkung noch vor einer Nachberechnung zu. Mit dem Verfahren ist es möglich, eine verbesserte Bewertung über die Auswirkung von Schäden und Mängeln an Stahlbetonbrücken auf deren Tragfähigkeit im Rahmen einer handnahen visuellen Bauwerksprüfung zu erreichen. Teil 1 behandelt die Grundlagen des Verfahrens sowie die Entwicklung der veränderten stochastischen Material‐ und Geometrieparameter infolge Schädigung. In Teil 2 wird die Modellunsicherheit “Bauwerksprüfer” sowie das baupraktische Näherungsverfahren für eine Anwendung im Rahmen der RI‐EBW‐PRÜF vorgestellt.

Basics and Development of Stochastic Models for a Structural Reliability Assessment of Reinforced Concrete Bridges on the Basis of the Results from Bridge Inspection

A probabilistic method based on the reliability theory allows a quick assessment of the load bearing capacity of damaged reinforced concrete bridges. The aim is to support the bridge inspection engineer during the bridge inspection according to DIN 1076 and not to replace a static recalculation. It should allow a quick decision as to whether or not a restriction of the crossing traffic is necessary. With this method it is possible to achieve a better assessment of the influence of damages on reinforced concrete bridges which are seen in a visual bridge inspection. Part 1 of the two papers describes the basics of the methodology and shows the development of the stochastic models for the material and geometry parameters which have changed as a result of damage. In Part 2 the model uncertainty for the bridge inspector and the practical use in accordance with the RI‐EBW‐PRÜF are shown.
Schlanke Fußgängerbrücke aus Textilbeton
Authors: Hegger Josef , Goralski Claus , Kulas Christian
Published: January 2011

In Albstadt‐Lautlingen wurde eine ältere Fußgängerbrücke aus Stahlbeton durch eine elegante Brücke aus Textilbeton ersetzt. Durch die Kombination von textilbewehrtem Beton mit einer Vorspannung ohne Verbund ließ sich eine für Betontragwerke außergewöhnliche Schlankheit erzielen. Die 97 m lange Brücke über die Bundesstraße B 463 besteht aus sechs Fertigteilen, die bei einer Elementlänge von 17,2 m eine Bauhöhe von 43 cm aufweisen. Im Beitrag werden Konstruktion, Bemessung und insbesondere das Schwingungsverhalten beschrieben. Die Untersuchungen zu den verwendeten Baustoffen sowie zum Tragverhalten und zur Dauerhaftigkeit finden sich in einem separaten Beitrag in diesem Heft.

A Pedestrian Bridge Made of Textile Reinforced Concrete

The pedestrian bridge over a state road in Albstadt, Germany, had to be torn down due to immense corrosion damages of the steel reinforcement and was replaced by a new bridge. The design of the new bridge allows a slender and durable construction with high demands on the concrete surface. The bridge with a total length of 97 m is subdivided in six prefabricated parts with a maximum element length of 17,2 m and a span of Ls = 15 m. The height of only 43 cm is possible by using the innovative composite material textile reinforced concrete. Thus, a slenderness of Ls/H = 35 and an extreme slender bridge construction is achieved. Due to the non‐corrosive textile reinforcement a very small concrete cover is possible and, thus, webs and cantilever arms can be designed very thin. The paper describes the construction, design and dynamic behaviour. A report on materials, load bearing behaviour and on the durability is available as a separate paper in this issue.
Massive Verbundbrücken für die Bahn
Authors: Seidl Günter , Müller Jens
Published: January 2011

In bestehenden Bahnstrecken sind zukünftig in großem Umfang Brücken zu erneuern, da viele Bauwerke nun ihre Lebensdauer erreicht haben. Hierfür sind Brückenkonzepte erforderlich, die die Erneuerungskosten und den Erhaltungsaufwand erheblich reduzieren. Brückenkontruktionen mit externer Bewehrung werden beiden Anforderungen gerecht.
Nachrechnen und Verstärken älterer Spannbetonbrücken
Authors: Haveresch Karlheinz
Published: January 2011

Es zeichnet sich ab, dass die Investitionen in die Verstärkung und Erneuerung des Straßenbrückenbestands in Deutschland zukünftig stark erhöht werden müssen, damit das Fernstraßennetz bestmöglich nutzbar bleibt. Erste Erfahrungen mit der Nachrechnung von Brücken zeigen, dass viele ältere Brücken sehr kurzfristig verstärkt oder erneuert werden müssen. Besonders kritische ältere Brücken, die nicht kurzfristig verstärkt oder erneuert werden können, müssen für den Schwerverkehr eingeschränkt werden, da sie nach den Regeln der Nachrechnungsrichtlinie erheblich überbeansprucht sind.

Zur Verstärkung älterer Spannbetonbrücken hat sich in den letzten Jahren eine Externe Vorspannung als vorteilhafteste Verstärkungstechnik herausgestellt. Die Regeln zur Bemessung, Konstruktion und Bauausführung sind inzwischen vielfach angewendet und erprobt. Noch verbleibende Regeln für die Querkraftbemessung älterer Spannbetonbrücken im Rahmen der Nachrechnung sind in der Entwicklung und müssen den Tragwerksplanern baldmöglichst zur Verfügung gestellt werden.

Checking and Strengthening older Prestressed Concrete Bridges

In Germany it seems to indicate, that very high investments are necessary to strengthen or replace older road bridges in order to maintain a sustainable and effective traffic infrastructure. First experiences with a new guideline for checking older bridges are, that many older bridges have to be checked and strengthened in a short‐term. Weak structures without strengthening have to be closed for the heavy‐duty traffic, because these bridges are overloaded.

The strengthening with additional external tendons is the best available technology for older prestressed concrete bridges. That is the experience of the last years. In the following paper principles of design, detailing possibilities and construction works are illustrated. Special rules for shear design of older bridges with low thrust reinforcement and additional external tendons are at the development stage.
Entwurf und Ausführungsplanung der Stöbnitztalbrücke
Authors: Jung Rolf , Marx Steffen , Schenkel Marcus , Stockmann Rico
Published: January 2011

Auf der Neubaustrecke Erfurt – Leipzig/Halle werden zurzeit einige Talbrücken realisiert, die einen neuen, ganzheitlich orientierten Entwurfsansatz verfolgen. Bei diesen integralen bzw. semi‐integralen Bauwerken sind die Überbauten monolithisch mit den Pfeilern und teilweise mit den Widerlagern verbunden. Sie können deshalb schlanker und mit stetigen Übergängen zwischen den Bauteilen ausgeführt werden. Durch den weitgehenden Verzicht auf Lager und Fugen und durch die robuste Bauweise besitzen integrale Bauwerke eine wesentlich längere Lebenserwartung als herkömmliche Talbrücken. Die Scherkondetalbrücke und die Gänsebachtalbrücke wurden bereits in vorherigen Ausgaben beschrieben. In diesem Beitrag wird über den Bau der Stöbnitztalbrücke berichtet, die als Sondervorschlag der ausführenden Baufirma realisiert wird.

The Bridge over Stoebnitz Valley – a Bridge without Bearings on High‐Speed Railway Route Erfurt – Leipzig/Halle

Currently some large valley bridges are under construction on high‐speed railway route Erfurt‐Leipzig/Halle. These bridges follow a new holistic design philosophy. The superstructures of those integral or semi‐integral bridges are rigidly connected to the abutments and the columns. Therefore, they are more slender than conventional bridges and the bridges are very robust and durable because of the omitting of bearings and dilatation joints. The bridges over Scherkonde valley and over Gaensebach valley were already described in previous issues. In this paper the construction of the bridge crossing Stoebnitz valley is reported. This bridge is being built as an alternate design of the contractor.
Randomized clinical trial of endovenous laser ablation compared with conventional surgery for great saphenous varicose veins
Authors: Carradice D , Mekako A I , Mazari F A K , Samuel N , Hatfield J , Chetter I C
Published: January 2011

Background

Endovenous laser ablation (EVLA) is a popular minimally invasive treatment for varicose veins. Surgical treatment, featuring junctional ligation and inversion stripping, has shown excellent clinical and cost effectiveness. The clinical effectiveness of both treatments was compared within a randomized trial.

Methods

Some 280 patients were randomized equally into groups receiving either surgery or EVLA. Participants had primary, symptomatic, unilateral venous insufficiency, with isolated saphenofemoral junction incompetence, leading to reflux into the great saphenous vein. Outcomes included: quality of life (QoL), Venous Clinical Severity Score (VCSS), pain scores and time taken to return to normal function. Owing to the nature of the procedures, blinding was not possible.

Results

Both groups had significant improvements in VCSS after treatment (P < 0·001), which resulted in improved disease-specific QoL (Aberdeen Varicose Vein Questionnaire, P < 0·001) and quality-adjusted life year (QALY) gain (P < 0·001). The pain and disability following surgery impaired normal function, with a significant decline in five of eight Short Form 36 (SF-36®) domains (P < 0·001 to P = 0·029). Periprocedural QoL was relatively preserved following EVLA, leading to a significant difference between the two treatments in pain scores (P < 0·001), six of eight SF-36® domains (P = 0·004 to P = 0·049) and QALYs (P = 0·003). As a result, surgical patients took longer to return to work and normal activity (14 versus 4 days; P < 0·001). Complications were rare.

Conclusion

EVLA was as effective as surgery for varicose veins, but had a less negative impact on early postintervention QoL. Registration number: NCT00759434 (http://www.clinicaltrials.gov).
Pd‐Catalyzed Borylative Polycyclization of Enediynes to Alkylboronates
Authors: Marco‐Martínez Juan , Buñuel Elena , López‐Durán Ruth , Cárdenas Diego J.
Published: January 2011

Pd‐catalyzed bicyclization of 1‐ene‐6,11‐diynes with bis(pinacolato)diboron smoothly affords synthetically useful homoallylic alkylboronates under mild conditions, avoiding the use of highly nucleophilic or basic reagents. One CB bond and two new CC bonds are created, and two new stereogenic centers are stereospecifically formed in a single tandem operation. The obtained products suggest a cascade reaction in which the last step is the transmetalation of bis(pinacolato)diboron, this being faster than a possible β‐hydride elimination process. The reaction is general and has been applied to enediynes with different substituents on the alkene unit, the bridging groups, and the alkyne moiety. The bicyclized alkylboronates thus obtained can be functionalized by oxidation to alcohols, formation of trifluoroborate salts, or by Suzuki coupling reactions.
Multivariate Statistical Identification of Human Bladder Carcinomas Using Ambient Ionization Imaging Mass Spectrometry
Authors: Dill Allison L. , Eberlin Livia S. , Costa Anthony B. , Zheng Cheng , Ifa Demian R. , Cheng Liang , Masterson Timothy A. , Koch Michael O. , Vitek Olga , Cooks R. Graham
Published: January 2011

Diagnosis of human bladder cancer in untreated tissue sections is achieved by using imaging data from desorption electrospray ionization mass spectrometry (DESI‐MS) combined with multivariate statistical analysis. We use the distinctive DESI‐MS glycerophospholipid (GP) mass spectral profiles to visually characterize and formally classify twenty pairs (40 tissue samples) of human cancerous and adjacent normal bladder tissue samples. The individual ion images derived from the acquired profiles correlate with standard histological hematoxylin and eosin (H&E)‐stained serial sections. The profiles allow us to classify the disease status of the tissue samples with high accuracy as judged by reference histological data. To achieve this, the data from the twenty pairs were divided into a training set and a validation set. Spectra from the tumor and normal regions of each of the tissue sections in the training set were used for orthogonal projection to latent structures (O‐PLS) treated partial least‐square discriminate analysis (PLS‐DA). This predictive model was then validated by using the validation set and showed a 5 % error rate for classification and a misclassification rate of 12 %. It was also used to create synthetic images of the tissue sections showing pixel‐by‐pixel disease classification of the tissue and these data agreed well with the independent classification that uses histological data by a certified pathologist. This represents the first application of multivariate statistical methods for classification by ambient ionization although these methods have been applied previously to other MS imaging methods. The results are encouraging in terms of the development of a method that could be utilized in a clinical setting through visualization and diagnosis of intact tissue.
Gold‐Nanoparticle‐Catalyzed Synthesis of Propargylamines: The Traditional A3‐Multicomponent Reaction Performed as a Two‐Step Flow Process
Authors: Abahmane Lahbib , Köhler J. Michael , Groß G. Alexander
Published: January 2011

The alkyne, aldehyde, amine A3‐coupling reaction, a traditional multicomponent reaction (MCR), has been investigated as a two‐step flow process. The implicated aminoalkylation reaction of phenylacetylene with appropriate aldimine intermediates was catalyzed by gold nanoparticles impregnated on alumina. The aldimine formation was catalyzed by Montmorillonite K10 beforehand. The performance of the process has been investigated with respect to different reaction regimes. Usually, the A3‐multicomponent reaction is performed as a “one‐pot” process. Diversity‐oriented syntheses using MCRs often have the shortcoming that only low selectivity and low yields are achieved. We have used a flow‐chemistry approach to perform the A3‐MCR in a sequential manner. In this way, the reaction performance was significantly enhanced in terms of shortened reaction time, and the desired propargylamines were obtained in high yields.
One‐Dimensional End‐To‐End Azide‐Bridged MnIII Complexes Incorporating Alkali Metal Ions: Slow Magnetic Relaxations and Metamagnetism
Authors: Yoon Jung Hee , Lee Jin Wuk , Ryu Dae Won , Yoon Sung Won , Suh Byoung Jin , Kim Hyoung Chan , Hong Chang Seop
Published: January 2011

Three azide‐bridged MnIII chains [Mn(3‐MeOsalpn)(N3)]⋅0.5 AClO4 (A=Na (1), K (2), Rb (3); 3‐MeOsalpn=N,N′‐propylenebis(3‐methoxysalicylideneiminato) dianion) incorporating alkali metal ions and perchlorate anions were systematically synthesized. The overall structure can be described as a one‐dimensional chain bridged by end‐to‐end azide ligands, although spatial arrangements of Jahn–Teller axes of Mn in 1 and 2 are different from that in 3. Relying on the alkali metal ions, magnetic properties are varied from a two‐step phase transition (1) to metamagnetic transitions (2 and 3). In this system, spin canting definitely plays a central role in giving rise to the apparent slow magnetic relaxations in 1 and 2 because application of a high external magnetic field tends to destroy single‐chain magnet (SCM) properties. Despite the existence of a long‐range antiferromagnetic order at TN, slow magnetic relaxation is notably observed in 2, which likely emanates from the operative spin canting below TN.
Pd‐ and Ni‐Catalyzed Cross‐Coupling Reactions of Functionalized Organozinc Reagents with Unsaturated Thioethers
Authors: Melzig Laurin , Metzger Albrecht , Knochel Paul
Published: January 2011

A variety of unsaturated thioethers have been subjected to cross‐coupling reactions with functionalized zinc reagents in the presence of a transition‐metal catalyst. Three different catalytic systems based on Pd(OAc)2or [Ni(acac)2] and the ligands S‐Phos or DPE‐Phos gave the best results. N‐Heterocyclic thioethers based on a pyridine, pyrimidine, pyrazine, pyridazine, triazine, benzothiazole, benzoxazole, pyrrole, or quinazoline ring, as well as thiomethylacetylenes, serve as electrophiles in this cross‐coupling reaction. Aryl‐, heteroaryl‐, benzylic, and alkylzinc halides with sensitive functionalities, such as ester, nitrile, or ketone groups react at ambient temperature with unsaturated thioethers using a Ni catalyst. The corresponding Pd‐catalyzed reactions require slightly higher temperatures. Large‐scale cross‐coupling experiments (10–20 mmol) with N‐heterocycles are also reported.
Sorption of ortho‐Phenylphenol to Soils
Authors: Zheng Chunli , Focks Andreas , Ellebrake Katrin , Eggers Till , Fries Elke
Published: January 2011

Conflicting sorption coefficients for ortho‐phenylphenol (OPP) have been reported in the literatures, which resulted in the conflicting assessments on OPP mobility in soil. To ascertain the sorption coefficient of OPP, batch experiments were performed based on OECD guideline 106, using three types of soils. Headspace solid‐phase microextraction (HS‐SPME) and GC‐MS were applied to the determination of OPP concentration in the liquid phase. The sorption isotherms obtained for all three soils under equilibrium conditions were described well, assuming linear sorption. The organic carbon normalized distribution coefficients (Koc) ranged from 894 to 1703 L kg−1, which suggested that OPP is moderately mobile in soil. The results also showed that the Koc value of OPP can be predicted precisely from Kow, whereas it was underestimated by one order of magnitude when water solubility is used.
Combinatorial Pharmacologic Effects of Gemcitabine and its Metabolite dFdU
Authors: Benyumov Alexey , Gurvich Vadim J. , Lis Lev G. , Williams Brent W. , Kirstein Mark N.
Published: January 2011

Recent evidence has shown that the gemcitabine metabolite, dFdU, is pharmacologically active. Though less potent, dFdU has a longer half‐life and could potentiate or antagonize the activity of gemcitabine. Hence, studies were undertaken to evaluate the combined effects. Following chemical synthesis, an improved purification procedure for dFdU was developed (80 % yield; >99 % purity). Zebrafish phenotype‐based embryo screens revealed no acute toxicity after gemcitabine or dFdU treatment. Only gemcitabine affected zebrafish development in a dose‐dependent manner. Synergy or antagonism for the combination was not observed. Antitumor effects for dFdU were dose dependent. Antagonism was tumor cell‐line dependent and did not depend on formation of the intracellular active metabolite of gemcitabine, suggesting that the drug–metabolite interaction occurs later. These studies highlight a platform for testing the pharmacologic activity for anticancer agent and metabolite combinations. Such analyses are expected to provide insight into the beneficial or harmful effect(s) of metabolites towards parent drug activity.
Improved Temporal Resolution and Linked Hidden Markov Modeling for Switchable Single‐Molecule FRET
Authors: Uphoff Stephan , Gryte Kristofer , Evans Geraint , Kapanidis Achillefs N.
Published: January 2011

Switchable FRET is the combination of single‐molecule Förster resonance energy transfer (smFRET) with photoswitching, the reversible activation and deactivation of fluorophores by light. By photoswitching, multiple donor–acceptor fluorophore pairs can be probed sequentially, thus allowing observation of multiple distances within a single immobilized molecule. Control of the photoinduced switching rates permits adjustment of the temporal resolution of switchable FRET over a wide range of timescales, thereby facilitating application to various dynamical biological systems. We show that fast total internal reflection (TIRF) microscopy can achieve measurements of two FRET pairs with 10 ms temporal resolution within less than 2 s. The concept of switchable FRET is also compatible with confocal microscopy on immobilized molecules, providing better data quality at high temporal resolution. To identify states and extract their transitions from switchable FRET time traces, we also develop linked hidden Markov modeling (HMM) of both FRET and donor–acceptor stoichiometry. Linked HMM successfully identifies transient states in the two‐dimensional FRET–stoichiometry space and reconstructs their connectivity network. Improved temporal resolution and novel data analysis make switchable FRET a valuable tool in molecular and structural biology.
DEC‐205 mediates antigen uptake and presentation by both resting and activated human plasmacytoid dendritic cells
Authors: Tel Jurjen , Benitez‐Ribas Daniel , Hoosemans Sander , Cambi Alessandra , Adema Gosse J. , Figdor Carl G. , Tacken Paul J. , de Vries I. Jolanda M.
Published: January 2011

DEC‐205 is a type I C‐type lectin receptor (CLR) that is expressed on various APC subsets and has been suggested to bind necrotic and apoptotic cells. Here we study DEC‐205 characteristics in plasmacytoid DCs (pDCs) obtained from healthy individuals and assess its ability to mediate antigen presentation by isolating sufficient numbers of pDCs from apheresis material obtained from stage III/IV melanoma patients. The results demonstrate that DEC‐205 is expressed on human pDCs. Internalization of DEC‐205 after antibody ligation is clathrin‐ and dynamin‐dependent as it is blocked by hypertonic shock or by inhibition of dynamin activity. Antibody targeting to DEC‐205 does not affect TLR‐induced expression levels of co‐stimulatory and MHC molecules, but clearly impairs TLR‐induced IFN‐α secretion by 40%. We observed that TLR‐mediated signaling increases DEC‐205 expression levels without affecting receptor internalization. Moreover, human pDCs retained the capacity to present antigens via DEC‐205 following TLR activation.
Hyaluronan binding identifies the most proliferative activated and memory T cells
Authors: Maeshima Nina , Poon Grace F. T. , Dosanjh Manisha , Felberg Jackie , Lee Sally S. M. , Cross Jennifer L. , Birkenhead Darlene , Johnson Pauline
Published: January 2011

CD44 is expressed on T cells where its ability to bind hyaluronan is tightly regulated. Here, we investigated when T cells bind hyaluronan during an immune response. We found that naïve, murine T cells do not bind fluoresceinated hyaluronan but are induced to bind upon antigen‐induced T‐cell activation in vitro and in vivo. Hyaluronan binding occurred on proliferating T cells and the percentage of hyaluronan‐binding cells correlated with the strength of the activation stimulus. A small percentage of hyaluronan‐binding cells persisted after in vitro activation and had a memory phenotype (CD122+CD44hi). This hyaluronan‐binding population increased after culture with IL‐7 or IL‐15 and proliferated more rapidly than nonbinding cells. In vivo, approximately 20–30% of antigen‐specific OT‐I CD8+ memory T cells in the spleen and BM bound hyaluronan. Hyaluronan binding identified memory cells that proliferated faster in IL‐7 and IL‐15, and enriched for CD62L+ central memory cells. In vivo homeostatic proliferation induced hyaluronan binding on a small percentage of the most rapidly dividing cells after several cell divisions. This study demonstrates that hyaluronan binding is induced upon antigen‐induced T‐cell activation and occurs on a percentage of the most proliferative activated and memory T cells.
HIV interferes with SOCS‐1 and ‐3 expression levels driving immune activation
Authors: Miller Regina C. , Schlaepfer Erika , Baenziger Stefan , Crameri Reto , Zeller Sabine , Byland Rahel , Audigé Annette , Nadal David , Speck Roberto F.
Published: January 2011

HIV infection is characterized by sustained immune activation, which is reflected by activated T cells and, in particular, by increased levels of phosphorylated STAT proteins. Here, we hypothesized that T‐cell activation in HIV infection is partially due to the inability of SOCS‐1 and SOCS‐3 to control the JAK/STAT pathway. We found higher levels of SOCS‐1/3 mRNA levels in CD4+ T cells of HIV‐infected patients than in healthy controls. However, SOCS protein levels were lower, explaining the lack of attenuation of the JAK/STAT pathway. Infection of CD4+ T cells alone did not activate STATs, while ex vivo infection of PBMC did, indicating that non‐T cells critical for shaping the immune response, e.g. DC were responsible for the STAT‐1 activation. Supernatants from ex vivo‐infected PBMC transferred to CD4+ T cells induced JAK/STAT activation, pointing to a central role of soluble factors. Notably, over‐expression of SOCS‐1/3 in CD4+ T cells prevented JAK/STAT activation. Thus, HIV infection interferes with SOCS‐1/3 expression driving immune activation. Sustained immune activation disrupts the lymphoid system and favors HIV replication since HIV preferentially infects activated cells. We speculate that regulating SOCS may be a potential way to counteract immune activation in HIV disease.
Molybdenum and Tungsten Oxidoreductase Models
Authors: Schulzke Carola
Published: January 2011

This microreview gives an overview about advances in bioinorganic model chemistry for molybdenum‐ and tungsten‐dependent oxidoreductases with respect to specific aspects of the evolution, structure or function of distinct active‐site properties. The approaches to evaluate catalytic properties fine‐tuned by the ligand sphere, interpret and assign enzyme spectra and to understand why two different metals are used for the same task but in distinct habitats and respective evolutionary aspects are discussed on the basis of exemplary case studies. This short review provides a personal perspective and appreciation of the complex problems associated with the respective foremost synthetic and analytical model chemistry and their solutions partly accompanied and supported by theoretical results.
Structural, Magnetic and Dynamic Characterization of Liquid Crystalline Iron(III) Schiff Base Complexes with Asymmetric Ligands
Authors: Domracheva Natalia , Pyataev Andrew , Manapov Rafil , Gruzdev Matvey , Chervonova Ulyana , Kolker Arkadij
Published: January 2011

The iron(III) complexes that were formed by coordination of the FeIII ion with the asymmetric tridentate liquid crystalline Schiff base ligand (L), the water molecules and the different counterions [PF6– (1), NO3– (2), and Cl– (3)] were studied by electron paramagnetic resonance (EPR) spectroscopy. EPR spectroscopy demonstrated that each of the complexes investigated consists of two types of iron centers: S = 1/2 low‐spin (LS) and S = 5/2 high‐spin (HS). LS iron complexes 2, 3 and LS complex 1 in the temperature range 4.2–250 K have a (dxz,dyz)4(dxy)1 ground state. Interesting features werefound for the monocationic FeIII complex 1, [Fe(L)X(H2O)2]+X–, with X = PF6– as the counterion. The LS and HS iron centers of 1 are coupled together antiferromagnetically and form a dimer structure by means of the water molecules and the PF6– counterion. The second‐type of LS and HS centers that are visible by means of EPR spectroscopy were best observed in the liquid crystalline (387–405 K) phase. The monitoring and the simulation of the EPR spectra enabled us to trace the dynamics of changing the number of the second‐type of LS centers with respect to the first‐type of LS centers. The observed dynamic process is characterized by the enthalpy value ΔH = 27.9 kJ/mol, which was caused by reorientation of the PF6– counterion. Calculation of the observed g values for the second‐type of LS complex 1 indicated that, in this case, the (dxy)2(dxz,dyz)3 ground state is stabilized. The conversion between the electron (dxz,dyz)4(dxy)1/(dxy)2(dxz,dyz)3 configurations was found to be temperature dependent and was detected in the same material for the first time in iron complexes.
C–H Activation in Diiron Bridging Vinyliminium Ligands: Reaction with CS2 to Form New Zwitterionic Complexes Acting as Organometallic Ligands
Authors: Marchetti Fabio , Zacchini Stefano , Salmi Mauro , Busetto Luigi , Zanotti Valerio
Published: January 2011

The reactions of vinyliminium complexes [Fe2{μ‐η1:η3‐C(R′)=C(H)C=N(Me)(R)}(μ‐CO)(CO)(Cp)2][SO3CF3] (R = Xyl, R′ = Me, 1a; R = Xyl, R′ = Tol, 1b; R = Xyl, R′ = COOMe, 1c; R = Me, R′ = Me, 1d; R = Me, R′ = nBu, 1e; R = p‐MeOC6H4, R′ = Me, 1f; Tol = 4‐C6H4Me, Xyl = 2,6‐Me2C6H3) with CS2 and NaH resulted in the replacement of CH hydrogen (in the bridging frame) with CS2 to give the corresponding dithiocarboxylate‐vinyliminium complexes [Fe2{μ‐η1:η3‐C(R′)=C(CS2)C=N(Me)(R)}(μ‐CO)(CO)(Cp)2] (2a–2f). Analogously, 1a and 1d reacted with NaH and SCNPh to afford the complexes[Fe2{μ‐η1:η3‐C(R′)=C{C(NPh)S}C=N(Me)(R)}(μ‐CO)(CO)(Cp)2](R = Xyl, R′ = Me, 3a; R = Me, R′ = Me, 3b), respectively. Complex 2b was methylated at the dithiocarboxylate group upon treatment with CH3SO3CF3 to yield [Fe2{μ‐η1:η3‐C(R′)=C(CS2Me)C=N(Me)(Xyl)}(μ‐CO)(CO)(Cp)2][SO3CF3] (4a). Likewise, the zwitterionic complexes 2d–f underwent addition of the metal fragment [Fe(CO)2Cp]+ at the dithiocarboxylate group to yield the corresponding triiron complexes [Fe2{μ‐η1:η3‐C(R′)=C(CS2Fp)C=N(Me)(R)}(μ‐CO)(CO)(Cp)2][SO3CF3] [R = R′ = Me, 4b; R = Me, R′ = nBu, 4c; R = p‐MeOC6H4, R′ = Me, 4d; Fp = Fe(CO)2Cp]. In a related reaction with [Pd(CH3CN)2Cl2], 2a binded to Pd through the dithiocarboxylate group as chelating ligand to afford the complex [PdCl2{κ2‐(S,S)‐2a}] (5). The X‐ray structures of 2b, 3a and 4d have been determined.
Studies on Tetrahydrofuran‐Based Highly O‐Functionalized Alkynes: Applications to Synthesis of Tetrahydrofuranyl‐Polyynes and C‐Nucleoside Analogues
Authors: Reddy P. Venkat , Bajpai Vikas , Kumar Brijesh , Shaw Arun K.
Published: January 2011

The enantiomerically pure tetrahydrofuranylalkynes 17–20 were synthesized by using various methods. By utilizing these alkynes, an efficient CuI‐catalysed sp‐sp carbon homo‐coupling protocol in dry DMF without other additives (like amine or base, phosphane and palladium catalyst) has been developed. The method has been applied to the synthesis of symmetrical butadiynyl (32–37), octatetraynyl (47) and dodecahexaynyl (49) polyynes. The unsymmetrically substituted diynes 39, 40 and 41 and triynes 43 and 44 were synthesized by coupling reaction between the newly synthesized bromoalkyne/diynes 38/42 and commercially available (trialkylsilyl)acetylenes. Syntheses of the 1,2,3‐triazolyl‐C‐nucleoside analogue 51 and of the ethynyl‐ and butadiynyl‐bridged 1,2,3‐triazolyl‐C‐nucleoside analogues 52 and 53 were performed by 1,3‐dipolar cycloaddition reaction (“click“ chemistry) of their respective alkyne precursors.