bluuebunny/crossref_metadata_2025 huggingface dataset:
A pipe network simulation model with dynamic transition between free surface and pressurized flow
Authors: Fernández-Pato J. , García-Navarro P.
Published: January 2014

Abstract. Water flow numerical simulation in urban pipe systems is one of the topics that shows the need for surface flows and pressurized flows in steady and transient situations. The governing equations for both flow types are different and this must be taken into account in order to get a complete numerical model for solving transients. A numerical simulation model is developed in this work, capable of solving pipe networks mainly unpressurized, with isolated peaks of pressurization. For this purpose, a reformulation of the mathematical model through the Preissmann slot method is proposed. By means of this technique, a reasonable estimation of the water pressure is calculated in cases of pressurization. The numerical model is based on the first order Roe's scheme, in the frame of finite volume methods. It is adapted to abrupt transient situations, with subcritial and supercritical flows. The validation has been done by means of several cases with analytic solutions or empirical laboratory data. It has also been applied to some more complex and realistic cases, like junctions or pipe networks.
In-flight calibration of double-probe DC electric field measurements on Cluster
Authors: Khotyaintsev Y. V. , Lindqvist P.-A. , Cully C. M. , Eriksson A. I. , André M.
Published: January 2014

Abstract. Double-probe electric field instrument with long wire booms is one of the most popular techniques for in situ measurement of DC and AC electric fields in plasmas on spinning spacecraft platforms, which have been employed on a large number of space missions. Here we present an overview of the calibration procedure used for the EFW instrument on Cluster, which involves spin fits of the data and correction of several offsets. We also describe the procedure for the offset determination and present results for the long-term evolution of the offsets.
Coupled prediction of flood response and debris flow initiation during warm- and cold-season events in the Southern Appalachians, USA
Authors: Tao J. , Barros A. P.
Published: January 2014

Abstract. Debris flows associated with rainstorms are a frequent and devastating hazard in the Southern Appalachians in the United States. Whereas warm-season events are clearly associated with heavy rainfall intensity, the same cannot be said for the cold-season events. Instead, there is a relationship between large (cumulative) rainfall events independently of season, and thus hydrometeorological regime, and debris flows. This suggests that the dynamics of subsurface hydrologic processes play an important role as a trigger mechanism, specifically through soil moisture redistribution by interflow. We further hypothesize that the transient mass fluxes associated with the temporal-spatial dynamics of interflow govern the timing of shallow landslide initiation, and subsequent debris flow mobilization. The first objective of this study is to investigate this relationship. The second objective is to assess the physical basis for a regional coupled flood prediction and debris flow warning system. For this purpose, uncalibrated model simulations of well-documented debris flows in headwater catchments of the Southern Appalachians using a 3-D surface–groundwater hydrologic model coupled with slope stability models are examined in detail. Specifically, we focus on two vulnerable headwater catchments that experience frequent debris flows, the Big Creek and the Jonathan Creek in the Upper Pigeon River Basin, North Carolina, and three distinct weather systems: an extremely heavy summertime convective storm in 2011; a persistent winter storm lasting several days; and a severe winter storm in 2009. These events were selected due to the optimal availability of rainfall observations; availability of detailed field surveys of the landslides shortly after they occurred, which can be used to evaluate model predictions; and because they are representative of events that cause major economic losses in the region. The model results substantiate that interflow is a useful prognostic of conditions necessary for the initiation of slope instability, and should therefore be considered explicitly in landslide hazard assessments. Moreover, the relationships between slope stability and interflow are strongly modulated by the topography and catchment-specific geomorphologic features that determine subsurface flow convergence zones. The three case studies demonstrate the value of coupled prediction of flood response and debris flow initiation potential in the context of developing a regional hazard warning system.
Environmental flow assessments in estuaries related to preference of phytoplankton
Authors: Yang Z. F. , Sun T. , Zhao R.
Published: January 2014

Abstract. We developed an approach to assess environmental flows in estuaries related to preference of phytoplankton considering the complex relationship between hydrological modification and biomass in ecosystems. As a first step, a relationship was established between biomass requirements for organisms of primary and higher nutritional levels based on the principle of nutritional energy flow of ecosystem. Then, diagnostic pigments were employed to represent phytoplankton community biomass, which indicated competition between two groups of phytoplankton in the biochemistry process. Considering empirical relationships between diagnostic pigments and critical environmental factors, responses of biomass to river discharges were established based on a convection–diffusion model by simulating distributions of critical environmental factors under action of river discharges and tide currents. Consequently, environmental flows could be recommended for different requirements of fish biomass. In the case study in the Yellow River estuary, May and October were identified as critical months for fish reproduction and growth during dry years. Artificial hydrological regulation strategies should carefully consider the temporal variations of natural flow regime, especially for a high-amplitude flood pulse, which may cause negative effects on phytoplankton groups and higher organism biomass.
Quantification of octacalcium phosphate, authigenic apatite and detrital apatite in coastal sediments using differential dissolution and standard addition
Authors: Oxmann J. F. , Schwendenmann L.
Published: January 2014

Abstract. Knowledge of calcium phosphate (Ca-P) solubility is crucial for understanding temporal and spatial variations of phosphorus (P) concentrations in water bodies and sedimentary reservoirs. In-situ relationships between liquid and solid-phase levels cannot be fully explained by dissolved analytes alone and need to be verified by determination of particular sediment P species. Lack of quantification methods for these species limits the knowledge of the P cycle. To address this issue, we (i) optimized a specifically developed conversion-extraction (CONVEX) method for P species quantification using standard additions; and (ii) simultaneously determined solubilities of Ca-P standards by measuring their pH-dependent contents in the sediment matrix. Ca-P minerals including various carbonate fluorapatite (CFAP) specimens from different localities, fluorapatite (FAP), fish bone apatite, synthetic hydroxylapatite (HAP) and octacalcium phosphate (OCP) were characterized by XRD, Raman, FTIR and elemental analysis. Sediment samples were incubated with and without these reference minerals and then sequentially extracted to quantify Ca-P species by their differential dissolution at pH values between 3 and 8. The quantification of solid-phase phosphates at varying pH revealed solubilities in the following order: OCP > HAP > CFAP (4.5% CO3) > CFAP (3.4% CO3) > CFAP (2.2% CO3) > FAP. Thus, CFAP was less soluble in sediment than HAP, and CFAP solubility increased with carbonate content. Unspiked sediment analyses together with standard addition analyses indicated consistent differential dissolution of natural sediment species vs. added reference species and therefore verified the applicability of the CONVEX method in separately determining the most prevalent Ca-P minerals. We found surprisingly high OCP contents in the analyzed coastal sediments which supports the hypothesis of apatite formation by an OCP precursor.
A 0.6 million year record of millennial‐scale climate variability in the tropics
Authors: Gibson Kelly Ann , Peterson Larry C.
Published: January 2014

A ~600 kyr long scanning X‐ray fluorescence record of redox variability from the Cariaco Basin, Venezuela, provides insight into rapid climate change in the tropics over the past five glacial‐interglacial cycles. Variations in the sediment accumulation of the redox‐sensitive element molybdenum (Mo) can be linked to changes in Intertropical Convergence Zone migration and reveal that millennial‐scale variability is a persistent feature of tropical climate over the past 600 kyr, including during periods of interglacial warmth. This new record supports the idea that high‐frequency tropical climate variability is not controlled solely by ice volume changes, with implications for the role of high‐latitude forcing of Intertropical Convergence Zone position and tropical hydrology on millennial timescales.
Swiss tree rings reveal warm and wet summers during medieval times
Authors: Kress Anne , Hangartner Sarah , Bugmann Harald , Büntgen Ulf , Frank David C. , Leuenberger Markus , Siegwolf Rolf T.W. , Saurer Matthias
Published: January 2014

We present a 1200 year drought reconstruction for the European Alpine region based on carbon isotope variations of tree rings from living larch trees and historic timber. The carbon isotope fractionation at the study site is sensitive to summer precipitation, temperature, and irradiance, resulting in a stable and high correlation with a drought index for interannual to decadal frequencies and possibly beyond (r2 = 0.58 for 1901–2004, July/August). When combining this information with maximum latewood density‐derived summer temperature, a strongly reduced occurrence of summer droughts during the warm A.D. 900–1200 period is evident, coinciding with the Medieval Climate Anomaly (MCA), with a shift to colder and drier conditions for the subsequent centuries. The warm‐wet MCA contrasts strongly with the climate of the drought‐prone warm phase of the recent decades, indicating different forcing mechanism for these two warm periods and pointing to beneficial conditions for agriculture and human well‐being during the MCA in this region.
Modeling ice‐ocean interaction in ice‐shelf crevasses
Authors: Jordan James R. , Holland Paul R. , Jenkins Adrian , Piggott Matthew D. , Kimura Satoshi
Published: January 2014

Ocean freezing within ice‐shelf basal crevasses could potentially act as a stabilizing influence on ice shelves; however, ice‐ocean interaction and ocean dynamics within these crevasses are as yet poorly understood. To this end, an idealized 2‐D model of an ice‐shelf basal crevasse has been developed using Fluidity, a finite‐element ocean model using an unstructured mesh. A simple model of frazil ice formation and deposition has been incorporated into Fluidity to better represent the freezing process. Model results show two different flow regimes, dependent on the amount of freezing in the crevasse: one driven by freezing at the top of the crevasse and the other by the ingress of meltwater from outside the crevasse. In the first, freezing at the top of the crevasse leads to the formation of an unstable overturning circulation due to the rejection of dense, salty water. In the second, a buoyant layer is formed along the sides and roof of the crevasse, stratifying the water column. Frazil ice precipitation is found to be the dominant freezing process at the top of the basal crevasse in the freeze‐driven case, with direct freezing being dominant in the melt‐driven case. In both cases, melting occurs lower down on the walls of the crevasse due to the strong overturning circulation. The freezing in ice‐shelf crevasses and rifts is found to be highly dependent upon ocean temperature, providing a stabilizing influence on ice shelves underlain by cold waters that is not present elsewhere.
Configuration and assessment of the GISS ModelE2 contributions to the CMIP5 archive
Authors: Schmidt Gavin A. , Kelley Max , Nazarenko Larissa , Ruedy Reto , Russell Gary L. , Aleinov Igor , Bauer Mike , Bauer Susanne E. , Bhat Maharaj K. , Bleck Rainer , Canuto Vittorio , Chen Yong‐Hua , Cheng Ye , Clune Thomas L. , Del Genio Anthony , de Fainchtein Rosalinda , Faluvegi Greg , Hansen James E. , Healy Richard J. , Kiang Nancy Y. , Koch Dorothy , Lacis Andy A. , LeGrande Allegra N. , Lerner Jean , Lo Ken K. , Matthews Elaine E. , Menon Surabi , Miller Ron L. , Oinas Valdar , Oloso Amidu O. , Perlwitz Jan P. , Puma Michael J. , Putman William M. , Rind David , Romanou Anastasia , Sato Makiko , Shindell Drew T. , Sun Shan , Syed Rahman A. , Tausnev Nick , Tsigaridis Kostas , Unger Nadine , Voulgarakis Apostolos , Yao Mao‐Sung , Zhang Jinlun
Published: January 2014

We present a description of the ModelE2 version of the Goddard Institute for Space Studies (GISS) General Circulation Model (GCM) and the configurations used in the simulations performed for the Coupled Model Intercomparison Project Phase 5 (CMIP5). We use six variations related to the treatment of the atmospheric composition, the calculation of aerosol indirect effects, and ocean model component. Specifically, we test the difference between atmospheric models that have noninteractive composition, where radiatively important aerosols and ozone are prescribed from precomputed decadal averages, and interactive versions where atmospheric chemistry and aerosols are calculated given decadally varying emissions. The impact of the first aerosol indirect effect on clouds is either specified using a simple tuning, or parameterized using a cloud microphysics scheme. We also use two dynamic ocean components: the Russell and HYbrid Coordinate Ocean Model (HYCOM) which differ significantly in their basic formulations and grid. Results are presented for the climatological means over the satellite era (1980–2004) taken from transient simulations starting from the preindustrial (1850) driven by estimates of appropriate forcings over the 20th Century. Differences in base climate and variability related to the choice of ocean model are large, indicating an important structural uncertainty. The impact of interactive atmospheric composition on the climatology is relatively small except in regions such as the lower stratosphere, where ozone plays an important role, and the tropics, where aerosol changes affect the hydrological cycle and cloud cover. While key improvements over previous versions of the model are evident, these are not uniform across all metrics.
Modifying Effect of N‐Acetyltransferase 2 Genotype on the Association Between Systemic Lupus Erythematosus and Consumption of Alcohol and Caffeine‐Rich Beverages
Authors: Kiyohara Chikako , Washio Masakazu , Horiuchi Takahiko , Asami Toyoko , Ide Saburo , Atsumi Tatsuya , Kobashi Gen , Takahashi Hiroki , Tada Yoshifumi ,   the Kyushu Sapporo SLE (KYSS) Study Group
Published: January 2014

Objective

N‐acetyltransferase 2 (NAT2) is involved in the metabolism of various environmental substances, both with and without carcinogenic potential. Alcoholic and nonalcoholic caffeine‐rich beverages may be associated with markers of inflammation. Systemic lupus erythematosus (SLE) is a chronic, multifaceted inflammatory disease. We investigated the effects of alcoholic and nonalcoholic caffeine‐rich beverages on risk of SLE and determined whether the effects were modified by NAT2 status.

Methods

The NAT2 polymorphism was genotyped in 152 SLE cases and 427 healthy controls, all women and Japanese. We assessed effect modification by testing an interaction term for the NAT2 polymorphism and consumption of beverages.

Results

Consumption of black tea (odds ratio [OR] 1.88, 95% confidence interval [95% CI] 1.03–3.41) and coffee (OR 1.57, 95% CI 0.95–2.61), but not green tea, was associated with an increased risk of SLE, while alcohol use (OR 0.33, 95% CI 0.20–0.55) was associated with a decreased risk of SLE. There were significant interactions between the NAT2 polymorphism and either alcohol use (Pinteraction = 0.026) or consumption of black tea (Pinteraction = 0.048).

Conclusion

The NAT2 polymorphism significantly modified the effects of alcohol use and black tea consumption on SLE, emphasizing the importance of incorporating genetic and metabolic information in studies on management of SLE. Additional studies are warranted to confirm the findings suggested in this study.
Adaptive control for high‐order time‐delay uncertain nonlinear system and application to chemical reactor system
Authors: Lv Li‐Na , Sun Zong‐Yao , Xie Xue‐Jun
Published: January 2014

This paper focuses on global adaptive state‐feedback stabilization for a class of high‐order uncertain nonlinear systems with multiple delays. Restriction on system growth is relaxed. Two dynamic gains are introduced to deal with uncertainty and nonlinear growth rate of the system. Without precise information about time‐delay being needed and only by like Lyapunov function, a new control strategy is presented based on homogeneous domination idea and two necessary transformations. As an application, the developed scheme is utilized to control design of a two‐stage chemical reactor with delayed recycle streams. Copyright © 2014 John Wiley & Sons, Ltd.
Engineering Biomolecular Microenvironments for Cell Instructive Biomaterials
Authors: Custódio Catarina A. , Reis Rui L. , Mano João F.
Published: January 2014

Engineered cell instructive microenvironments with the ability to stimulate specific cellular responses are a topic of high interest in the fabrication and development of biomaterials for application in tissue engineering. Cells are inherently sensitive to the in vivo microenvironment that is often designed as the cell “niche.” The cell “niche” comprising the extracellular matrix and adjacent cells, influences not only cell architecture and mechanics, but also cell polarity and function. Extensive research has been performed to establish new tools to fabricate biomimetic advanced materials for tissue engineering that incorporate structural, mechanical, and biochemical signals that interact with cells in a controlled manner and to recapitulate the in vivo dynamic microenvironment. Bioactive tunable microenvironments using micro and nanofabrication have been successfully developed and proven to be extremely powerful to control intracellular signaling and cell function. This Review is focused in the assortment of biochemical signals that have been explored to fabricate bioactive cell microenvironments and the main technologies and chemical strategies to encode them in engineered biomaterials with biological information.
A Straightforward Organocatalytic Alkylation of 2‐Arylacetaldehydes: An Approach towards Bisabolanes
Authors: Gualandi Andrea , Canestrari Pietro , Emer Enrico , Cozzi Pier Giorgio
Published: January 2014

A highly stereoselective organocatalytic α‐alkylation of 2‐arylacetaldehydes with a commercially available carbenium tetrafluoroborate is described. The stereoselective alkylation was carried out in acetonitrile/water, under air in the presence of a commercially available imidazolidinone (MacMillan’s catalyst). Key intermediates for the synthesis of bisabolanes were obtained through a simple chemistry. In particular a direct, enantioselective and facile synthesis of (R)‐(−)‐curcumene is described.

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Silicon‐Microtube Scaffold Decorated with Anatase TiO2 as a Negative Electrode for a 3D Litium‐Ion Microbattery
Authors: Eustache Etienne , Tilmant Pascal , Morgenroth Laurence , Roussel Pascal , Patriarche Gilles , Troadec David , Rolland Nathalie , Brousse Thierry , Lethien Christophe
Published: January 2014

An optimized scaffold based on silicon microtubes is designed to increase the surface capacity of 3D lithium‐ion microbatteries. High‐depth, mechanically robust microstructures are fabricated using microelectronic facilities. Conformal deposition of anatase TiO2 is achieved using atomic layer deposition, realizing the targeted improvement for microbatteries; a surface capacity of 0.2 mA h cm–2 at a charge rate of C/10 is obtained in standard liquid electrolyte. This work paves the way for the fabrication of solid‐state 3D Li‐ion microbatteries with an efficient 3D scaffold.
Iron deficiency alters megakaryopoiesis and platelet phenotype independent of thrombopoietin
Authors: Evstatiev Rayko , Bukaty Adam , Jimenez Kristine , Kulnigg‐Dabsch Stefanie , Surman Lidia , Schmid Werner , Eferl Robert , Lippert Kathrin , Scheiber‐Mojdehkar Barbara , Michael Kvasnicka Hans , Khare Vineeta , Gasche Christoph
Published: January 2014

Iron deficiency is a common cause of reactive thrombocytosis, however, the exact pathways have not been revealed. Here we aimed to study the mechanisms behind iron deficiency‐induced thrombocytosis. Within few weeks, iron‐depleted diet caused iron deficiency in young Sprague–Dawley rats, as reflected by a drop in hemoglobin, mean corpuscular volume, hepatic iron content and hepcidin mRNA in the liver. Thrombocytosis established in parallel. Moreover, platelets produced in iron deficient animals displayed a higher mean platelet volume and increased aggregation. Bone marrow studies revealed subtle alterations that are suggestive of expansion of megakaryocyte progenitors, an increase in megakaryocyte ploidy and accelerated megakaryocyte differentiation. Iron deficiency did not alter the production of hematopoietic growth factors such as thrombopoietin, interleukin 6 or interleukin 11. Megakaryocytic cell lines grown in iron‐depleted conditions exhibited reduced proliferation but increased ploidy and cell size. Our data suggest that iron deficiency increases megakaryopoietic differentiation and alters platelet phenotype without changes in megakaryocyte growth factors, specifically TPO. Iron deficiency‐induced thrombocytosis may have evolved to maintain or increase the coagulation capacity in conditions with chronic bleeding. Am. J. Hematol. 89:524–529, 2014. © 2014 Wiley Periodicals, Inc.
Aktuelle Anwendungen für Phasenübergangsmaterialien (PCMs): auch Hans kann noch was lernen!
Authors: Hyun Dong Choon , Levinson Nathanael S. , Jeong Unyong , Xia Younan
Published: January 2014

Der nebulöse Begriff Phasenübergangsmaterial (phase change material, PCM) bezieht sich auf jegliche Substanz mit einer hohen Schmelzwärme und einem scharfen Schmelzpunkt. PCMs werden seit Jahren in kommerziellen Anwendungen eingesetzt, im Wesentlichen für Wärmemanagementzwecke. Seit kurzem finden diese faszinierenden Materialien jedoch eine neue Verwendung in vielfältigen Technologiebereichen, die von einem zielgerichteten Wirkstofftransport, über Informationsspeicherung, Strichcodierung bis hin zur Detektion reichen. Mit diesem Aufsatz möchten wir das Interesse an dieser unglaublich vielseitigen Materialklasse neu beleben und verschiedenste Aspekte im Hinblick auf Zusammensetzungen, Herstellung und neue Anwendungen von PCMs beleuchten.
Toehold‐initiated Rolling Circle Amplification for Visualizing Individual MicroRNAs In Situ in Single Cells
Authors: Deng Ruijie , Tang Longhua , Tian Qianqian , Wang Ying , Lin Lei , Li Jinghong
Published: January 2014

The ability to quantitate and visualize microRNAs (miRNAs) in situ in single cells would greatly facilitate the elucidation of miRNA‐mediated regulatory circuits and their disease associations. A toehold‐initiated strand‐displacement process was used to initiate rolling circle amplification of specific miRNAs, an approach that achieves both stringent recognition and in situ amplification of the target miRNA. This assay, termed toehold‐initiated rolling circle amplification (TIRCA), can be utilized to identify miRNAs at physiological temperature with high specificity and to visualize individual miRNAs in situ in single cells within 3 h. TIRCA is a competitive candidate technique for in situ miRNA imaging and may help us to understand the role of miRNAs in cellular processes and human diseases in more detail.
Iridium‐Catalyzed Direct CH Amidation with Weakly Coordinating Carbonyl Directing Groups under Mild Conditions
Authors: Kim Jinwoo , Chang Sukbok
Published: January 2014

An iridium‐catalyzed direct CH amidation of weakly coordinating substrates, in particular of those bearing ester and ketone groups, under very mild conditions has been developed. The observed high reaction efficiency was achieved by the combined use of acetic acid and lithium carbonate as additives.
Heart Regeneration: Opportunities and Challenges for Drug Discovery with Novel Chemical and Therapeutic Methods or Agents
Authors: Plowright Alleyn T. , Engkvist Ola , Gill Adrian , Knerr Laurent , Wang Qing‐Dong
Published: January 2014

Following a heart attack, more than a billion cardiac muscle cells (cardiomyocytes) can be killed, leading to heart failure and sudden death. Much research in this area is now focused on the regeneration of heart tissue through differentiation of stem cells, proliferation of existing cardiomyocytes and cardiac progenitor cells, and reprogramming of fibroblasts into cardiomyocytes. Different chemical modalities (i.e. methods or agents), ranging from small molecules and RNA approaches (including both microRNA and anti‐microRNA) to modified peptides and proteins, are showing potential to meet this medical need. In this Review, we outline the recent advances in these areas and describe both the modality and progress, including novel screening strategies to identify hits, and the upcoming challenges and opportunities to develop these hits into pharmaceuticals, at which chemistry plays a key role.
Structural Basis of Microtubule Stabilization by Laulimalide and Peloruside A
Authors: Prota Andrea E. , Bargsten Katja , Northcote Peter T. , Marsh May , Altmann Karl‐Heinz , Miller John H. , Díaz José Fernando , Steinmetz Michel O.
Published: January 2014

Laulimalide and peloruside A are microtubule‐stabilizing agents (MSAs), the mechanism of action on microtubules of which is poorly defined. Here, using X‐ray crystallography it is shown that laulimalide and peloruside A bind to a unique non‐taxane site on β‐tubulin and use their respective macrolide core structures to interact with a second tubulin dimer across protofilaments. At the same time, they allosterically stabilize the taxane‐site M‐loop that establishes lateral tubulin contacts in microtubules. Structures of ternary complexes of tubulin with laulimalide/peloruside A and epothilone A are also solved, and a crosstalk between the laulimalide/peloruside and taxane sites via the M‐loop of β‐tubulin is found. Together, the data define the mechanism of action of laulimalide and peloruside A on tubulin and microtubules. The data further provide a structural framework for understanding the synergy observed between two classes of MSAs in tubulin assembly and the inhibition of cancer cell growth.
Mechanistic Insights into the Interface‐Directed Transformation of Thiols into Disulfides and Molecular Hydrogen by Visible‐Light Irradiation of Quantum Dots
Authors: Li Xu‐Bing , Li Zhi‐Jun , Gao Yu‐Ji , Meng Qing‐Yuan , Yu Shan , Weiss Richard G. , Tung Chen‐Ho , Wu Li‐Zhu
Published: January 2014

Quantum dots (QDs) offer new and versatile ways to harvest light energy. However, there are few examples involving the utilization of QDs in organic synthesis. Visible‐light irradiation of CdSe QDs was found to result in virtually quantitative coupling of a variety of thiols to give disulfides and H2 without the need for sacrificial reagents or external oxidants. The addition of small amounts of nickel(II) salts dramatically improved the efficiency and conversion through facilitating the formation of hydrogen atoms, thereby leading to faster regeneration of the ground‐state QDs. Mechanistic studies reveal that the coupling reaction occurs on the QD surfaces rather than in solution and offer a blueprint for how these QDs may be used in other photocatalytic applications. Because no sacrificial agent or oxidant is necessary and the catalyst is reusable, this method may be useful for the formation of disulfide bonds in proteins as well as in other systems sensitive to the presence of oxidants.
High performance of bamboo‐based fiber composites from long bamboo fiber bundles and phenolic resins
Authors: Yu Yang‐Lun , Huang Xian‐Ai , Yu Wen‐Ji
Published: January 2014

Lignocellulosic materials can be used for the development of bio‐based composites. This study explores the potential of long bamboo fiber bundles extracted directly from bamboo stems using the novel mechanical method and bamboo‐based fiber composites (BFC) fabricated using long bamboo fiber bundles and phenolic resins via cold pressing and thermal cure process. The microstructure, mechanical properties, and durability of BFC were evaluated, results being compared with raw bamboo and other commercialized bamboo fiber composites. The mechanical properties of BFC reinforced with 87% (w/w) long bamboo fiber bundles increased more than 50% than those of raw bamboo and were significantly higher than those of other bamboo‐based composites. Lower water absorption and thickness swelling were obtained in the case where bamboo fiber bundles with the small fineness. Higher tensile strength was obtained in the case where bamboo fiber bundles with large sizes of bamboo fiber bundles. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40371.
Influence of the synthesis conditions on the structural and thermal properties of poly(l‐lactide)‐b‐poly(ethylene glycol)‐b‐poly(l‐lactide)
Authors: Trinca Rafael Bergamo , Felisberti Maria Isabel
Published: January 2014

The poly(l‐lactide)‐b‐poly(ethylene glycol)‐b‐poly(l‐lactide) block copolymers (PLLA‐b‐PEG‐b‐PLLA) were synthesized in a toluene solution by the ring‐opening polymerization of 3,6‐dimethyl‐1,4‐dioxan‐2,5‐dione (LLA) with PEG as a macroinitiator or by transterification from the homopolymers [polylactide and PEG]. Two polymerization conditions were adopted: method A, which used an equimolar catalyst/initiator molar ratio (1–5 wt %), and method B, which used a catalyst content commonly reported in the literature (<0.05 wt %). Method A was more efficient in producing copolymers with a higher yield and monomer conversion, whereas method B resulted in a mixture of the copolymer and homopolymers. The copolymers achieved high molar masses and even presenting similar global compositions, the molar mass distribution and thermal properties depends on the polymerization method. For instance, the suppression of the PEG block crystallization was more noticeable for copolymer A. An experimental design was used to qualify the influence of the catalyst and homopolymer amounts on the transreactions. The catalyst concentration was shown to be the most important factor. Therefore, the effectiveness of method A to produce copolymers was partly due to the transreactions. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40419.
Pregnancy Outcome After Methotrexate Treatment for Rheumatic Disease Prior to or During Early Pregnancy: A Prospective Multicenter Cohort Study
Authors: Weber‐Schoendorfer Corinna , Chambers Christina , Wacker Evelin , Beghin Delphine , Bernard Nathalie ,   on behalf of the Network of French Pharmacovigilance Centers, Shechtman Svetlana , Johnson Diana , Cuppers‐Maarschalkerweerd Benedikte , Pistelli Alessandra , Clementi Maurizio , Winterfeld Ursula , Eleftheriou Georgios , Pupco Anna , Kao Kelly , Malm Heli , Elefant Elisabeth , Koren Gideon , Vial Thierry , Ornoy Asher , Meister Reinhard , Schaefer Christof
Published: January 2014

Objective

High‐dose methotrexate (MTX) exposure during pregnancy is associated with embryopathy. The teratogenic potential of MTX at dosages typically used in the treatment of rheumatic diseases remains uncertain. The aim of this study was to evaluate the risk of spontaneous abortion, major birth defects, elective termination of pregnancy, shortened gestational age at delivery, and reduced birth weight in women exposed to MTX.

Methods

Pregnancy outcome in women taking MTX (≤30 mg/week) either after conception or within the 12 weeks before conception was evaluated in a prospective observational multicenter cohort study. Pregnancy outcomes in the MTX group were compared to outcomes in a group of disease‐matched women and a group of women without autoimmune diseases (neither group was exposed to MTX).

Results

The study sample included 324 MTX‐exposed pregnancies (188 exposed post‐conception, 136 exposed pre‐conception), 459 disease‐matched comparison women, and 1,107 comparison women without autoimmune diseases. In the post‐conception cohort, the cumulative incidence of spontaneous abortion was 42.5% (95% confidence interval [95% CI] 29.2–58.7), which was significantly higher than the incidence of spontaneous abortion in either comparison group. The risk of major birth defects (7 of 106 [6.6%]) was elevated compared to both the cohort of women without autoimmune diseases (29 of 1,001 [2.9%]) (adjusted odds ratio [OR] 3.1 [95% CI 1.03–9.5]) and the disease‐matched cohort (14 of 393 [3.6%]) (adjusted OR 1.8 [95% CI 0.6–5.7]). None of the malformations were clearly consistent with MTX embryopathy. Neither the cumulative incidence of spontaneous abortion (14.4% [95% CI 8.0–25.3]) nor the risk of major birth defects (4 of 114 [3.5%]) was increased in the pre‐conception cohort. Elective termination rates were increased in both of the MTX‐exposed cohorts. There were no other significant differences among groups in other study end points.

Conclusion

Post‐conception administration of MTX at dosages typically used in the treatment of rheumatic diseases was associated with an increased risk of major birth defects and spontaneous abortion. Such evidence was not found among women in our pre‐conception cohort.
Myeloid‐Related Proteins 8 and 14 Contribute to Monosodium Urate Monohydrate Crystal–Induced Inflammation in Gout
Authors: Holzinger Dirk , Nippe Nadine , Vogl Thomas , Marketon Kristina , Mysore Vijayashree , Weinhage Toni , Dalbeth Nicola , Pool Bregina , Merriman Tony , Baeten Dominique , Ives Annette , Busso Nathalie , Foell Dirk , Bas Sylvette , Gabay Cem , Roth Johannes
Published: January 2014

Objective

Monosodium urate monohydrate (MSU) crystal–induced interleukin‐1β (IL‐1β) secretion is a critical factor in the pathogenesis of gout. However, without costimulation by a proIL‐1β–inducing factor, MSU crystals alone are insufficient to induce IL‐1β secretion. The responsible costimulatory factors that act as a priming endogenous signal in vivo are not yet known. We undertook this study to analyze the costimulatory properties of myeloid‐related protein 8 (MRP‐8) and MRP‐14 (endogenous Toll‐like receptor 4 [TLR‐4] agonists) in MSU crystal–induced IL‐1β secretion and their relevance in gout.

Methods

MRP‐8/MRP‐14 was measured in paired serum and synovial fluid samples by enzyme‐linked immunosorbent assay (ELISA) and localized in synovial tissue from gout patients by immunohistochemistry. Serum levels were correlated with disease activity, and MSU crystal–induced release of MRPs from human phagocytes was measured. Costimulatory effects of MRP‐8 and MRP‐14 on MSU crystal–induced IL‐1β secretion from phagocytes were analyzed in vitro by ELISA, Western blotting, and polymerase chain reaction. The impact of MRP was tested in vivo in a murine MSU crystal–induced peritonitis model.

Results

MRP‐8/MRP‐14 levels were elevated in the synovium, tophi, and serum of patients with gout and correlated with disease activity. MRP‐8/MRP‐14 was released by MSU crystal–activated phagocytes and increased MSU crystal–induced IL‐1β secretion in a TLR‐4–dependent manner. Targeted deletion of MRP‐14 in mice led to a moderately reduced response of MSU crystal–induced inflammation in vivo.

Conclusion

MRP‐8 and MRP‐14, which are highly expressed in gout, are enhancers of MSU crystal–induced IL‐1β secretion in vitro and in vivo. These endogenous TLR‐4 ligands released by activated phagocytes contribute to the maintenance of inflammation in gout.
Modulation of the Relationship Between External Knee Adduction Moments and Medial Joint Contact Forces Across Subjects and Activities
Authors: Trepczynski Adam , Kutzner Ines , Bergmann Georg , Taylor William R. , Heller Markus O.
Published: January 2014

Objective

The external knee adduction moment (EAM) is often considered a surrogate measure of the distribution of loads across the tibiofemoral joint during walking. This study was undertaken to quantify the relationship between the EAM and directly measured medial tibiofemoral contact forces (Fmed) in a sample of subjects across a spectrum of activities.

Methods

The EAM for 9 patients who underwent total knee replacement was calculated using inverse dynamics analysis, while telemetric implants provided Fmed for multiple repetitions of 10 activities, including walking, stair negotiation, sit‐to‐stand activities, and squatting. The effects of the factors “subject” and “activity” on the relationships between Fmed and EAM were quantified using mixed‐effects regression analyses in terms of the root mean square error (RMSE) and the slope of the regression.

Results

Across subjects and activities a good correlation between peak EAM and Fmed values was observed, with an overall R2 value of 0.88. However, the slope of the linear regressions varied between subjects by up to a factor of 2. At peak EAM and Fmed, the RMSE of the regression across all subjects was 35% body weight (%BW), while the maximum error was 127 %BW.

Conclusion

The relationship between EAM and Fmed is generally good but varies considerably across subjects and activities. These findings emphasize the limitation of relying solely on the EAM to infer medial joint loading when excessive directed cocontraction of muscles exists and call for further investigations into the soft tissue–related mechanisms that modulate the internal forces at the knee.
A condition‐based imperfect replacement policy for a periodically inspected system with two dependent wear indicators
Authors: Mercier Sophie , Pham Hai Ha
Published: January 2014

A two‐component system is considered, which is subject to accumulative deterioration. Because of common stress, the components are dependent. Their joint deterioration is modelled with a bivariate nondecreasing Lévy process. The deterioration level of both components is known only through perfect and periodic inspections. By an inspection, components with deterioration level beyond a specific threshold are instantaneously replaced by new ones (corrective or preventive replacements). Otherwise, they are left as they are. Between inspections, failures remain unrevealed. This replacement policy is classical in a univariate setting, with deterioration modelled by a Gamma process. In the bivariate case, it leads to imperfect repairs at the system level, which highly complicates the study. The replacement policy is assessed through cost functions on both finite and infinite horizons, which take into account some economical dependence between components. Markov renewal theory is used to study the behaviour of the system, in a continuous and bivariate setting. Numerical experiments illustrate the study, considering a specific Lévy process with univariate Gamma processes as margins. Although technical details are not provided here for the numerical computations, the paper shows that there is a technical gap between the traditional one‐dimensional studies and the present two‐dimensional one, especially for the computation of the asymptotic distribution of the underlying Markov chain. Hence, there is a need for further development in the bivariate (or multivariate) setting. Copyright © 2014 John Wiley & Sons, Ltd.
FRET‐based and other fluorescent proteinase probes
Authors: Hu Hai‐Yu , Gehrig Stefanie , Reither Gregor , Subramanian Devaraj , Mall Marcus A. , Plettenburg Oliver , Schultz Carsten
Published: January 2014

The continuous detection of enzyme activities and their application in medical diagnostics is one of the challenges in the translational sciences. Proteinases represent one of the largest groups of enzymes in the human genome and many diseases are based on malfunctions of proteolytic activity. Fluorescent sensors may shed light on regular and irregular proteinase activity in vitro and in vivo and provide a deeper insight into the function of these enzymes and their role in pathophysiological processes. The focus of this review is on Förster resonance energy transfer (FRET)‐based proteinase sensors and reporters because these probes are most likely to provide quantitative data. The medical relevance of proteinases are discussed using lung diseases as a prominent example. Probe design and probe targeting are described and fluorescent probe development for disease‐relevant proteinases, including matrix‐metalloproteinases, cathepsins, caspases, and other selected proteinases, is reviewed.
Systematic review and meta-analysis of enhanced recovery programmes in surgical patients
Authors: Nicholson A , Lowe M C , Parker J , Lewis S R , Alderson P , Smith A F
Published: January 2014

Background

Enhanced recovery programmes (ERPs) have been developed over the past 10 years to improve patient outcomes and to accelerate recovery after surgery. The existing literature focuses on specific specialties, mainly colorectal surgery. The aim of this review was to investigate whether the effect of ERPs on patient outcomes varies across surgical specialties or with the design of individual programmes.

Methods

MEDLINE, Embase, CINAHL and the Cochrane Central Register of Controlled Trials were searched from inception to January 2013 for randomized or quasi-randomized trials comparing ERPs with standard care in adult elective surgical patients.

Results

Thirty-eight trials were included in the review, with a total of 5099 participants. Study design and quality was poor. Meta-analyses showed that ERPs reduced the primary length of stay (standardized mean difference −1·14 (95 per cent confidence interval −1·45 to −0·85)) and reduced the risk of all complications within 30 days (risk ratio (RR) 0·71, 95 per cent c.i. 0·60 to 0·86). There was no evidence of a reduction in mortality (RR 0·69, 95 per cent c.i. 0·34 to 1·39), major complications (RR 0·95, 0·69 to 1·31) or readmission rates (RR 0·96, 0·59 to 1·58). The impact of ERPs was similar across specialties and there was no consistent evidence that elements included within ERPs affected patient outcomes.

Conclusion

ERPs are effective in reducing length of hospital stay and overall complication rates across surgical specialties. It was not possible to identify individual components that improved outcome. Qualitative synthesis may be more appropriate to investigate the determinants of success.
Observations from the IMPROVE trial concerning the clinical care of patients with ruptured abdominal aortic aneurysm
Authors:   IMPROVE trial investigators, Powell J T , Hinchliffe R J , Thompson M M , Sweeting M J , Ashleigh R , Bell R , Gomes M , Greenhalgh R M , Grieve R J , Heatley F , Thompson S G , Ulug P
Published: January 2014

Background

Single-centre series of the management of patients with ruptured abdominal aortic aneurysm (AAA) are usually too small to identify clinical factors that could improve patient outcomes.

Methods

IMPROVE is a pragmatic, multicentre randomized clinical trial in which eligible patients with a clinical diagnosis of ruptured aneurysm were allocated to a strategy of endovascular aneurysm repair (EVAR) or to open repair. The influences of time and manner of hospital presentation, fluid volume status, type of anaesthesia, type of endovascular repair and time to aneurysm repair on 30-day mortality were investigated according to a prespecified plan, for the subgroup of patients with a proven diagnosis of ruptured or symptomatic AAA. Adjustment was made for potential confounding factors.

Results

Some 558 of 613 randomized patients had a symptomatic or ruptured aneurysm: diagnostic accuracy was 91·0 per cent. Patients randomized outside routine working hours had higher operative mortality (adjusted odds ratio (OR) 1·47, 95 per cent confidence interval 1·00 to 2·17). Mortality rates after primary and secondary presentation were similar. Lowest systolic blood pressure was strongly and independently associated with 30-day mortality (51 per cent among those with pressure below 70 mmHg). Patients who received EVAR under local anaesthesia alone had greatly reduced 30-day mortality compared with those who had general anaesthesia (adjusted OR 0·27, 0·10 to 0·70).

Conclusion

These findings suggest that the outcome of ruptured AAA might be improved by wider use of local anaesthesia for EVAR and that a minimum blood pressure of 70 mmHg is too low a threshold for permissive hypotension.
Neurofilament Heavy polypeptide CpG island methylation associates with prognosis of renal cell carcinoma and prediction of antivascular endothelial growth factor therapy response
Authors: Dubrowinskaja Natalia , Gebauer Kai , Peters Inga , Hennenlotter Jörg , Abbas Mahmoud , Scherer Ralph , Tezval Hossein , Merseburger Axel S. , Stenzl Arnulf , Grünwald Viktor , Kuczyk Markus A. , Serth Jürgen
Published: January 2014

Neurofilament Heavy polypeptid (NEFH) belongs to the group of type IV intermediate filament proteins. DNA methylation of the NEFH promoter and loss of expression have previously been shown to activate the AKT/β‐catenin pathway in tumor cells. When identifying hypermethylation of the NEFH CpG island (CGI) in renal cell cancer (RCC) we asked whether methylation could provide clinical or prognostic information for RCC and/or predict therapy response in patients with metastatic RCC (mRCC) undergoing antiangiogenic therapy. Relative methylation of the NEFH CGI was analyzed in 132 RCC samples and 83 paired normal tissues using quantitative methylation‐specific PCR. Results were statistically compared with tumor histology, clinicopathological parameters, progression‐free survival (PFS) as well as with overall survival (OS) in a subset of 18 mRCC patients following antiangiogenic therapy regimens. The NEFH CGI methylation demonstrated a tumor‐specific increase (P < 0.001), association with advanced disease (P < 0.001), and distant metastasis (P = 0.005). Higher relative methylation was also significantly associated with a poor PFS (HR = 8.6, P < 0.001) independent from the covariates age, gender, diameter of tumors, state of advanced disease, and local and distant metastasis. Median OS following targeted therapy was 29.8 months for patients with low methylation versus 9.8 months for the group with high methylation (P = 0.028). We identified NEFH methylation as a candidate epigenetic marker for prognosis of RCC patients as well as prediction of anti‐vascular endothelial growth factor‐based therapy response.