bluuebunny/crossref_metadata_2025_split huggingface dataset:
Domain Models of Ferromagnetic Shape Memory Materials
Authors: Rößler Ulrich K. 
Published: July 2012

AbstractMagnetic shape‐memory materials are multiferroics that combine ferroelastic and ferromagnetic order. The diffusionless transformation processes in these materials unroll by the creation of crystallographic domains or twinned microstructures that are coupled to magnetic domain patterns. Miniaturization of the crystallographic domains to the scale of lattice unit cells is afforded by the concept of adaptive modulated martensite. A ferroelastic model for these crystallographic domain patterns is introduced for the exemplary case of the Ni2MnGa Heusler alloy. The pseudo‐microscopic model incorporates data from ab initio calculations and phonon dispersion. The twin‐boundary energy for the diffuse wall of this model are very low of the order 1 mJ · m−2 fulfilling a key requirement for the formation of adaptive martensite in this material. An extension of the Ginzburg–Landau phase‐field model for large strain gradients is introduced to model atomically sharp twin‐boundaries.
Semi‐Transparent Tandem Organic Solar Cells with 90% Internal Quantum Efficiency
Authors: Tang Zheng , George Zandra , Ma Zaifei , Bergqvist Jonas , Tvingstedt Kristofer , Vandewal Koen , Wang Ergang , Andersson L. Mattias , Andersson Mats R. , Zhang Fengling , Inganäs Olle 
Published: July 2012

AbstractSemi‐transparent (ST) organic solar cells with potential application as power generating windows are studied. The main challenge is to find proper transparent electrodes with desired electrical and optical properties. In this work, this is addressed by employing an amphiphilic conjugated polymer PFPA‐1 modified ITO coated glass substrate as the ohmic electron‐collecting cathode and PEDOT:PSS PH1000 as the hole‐collecting anode. For active layers based on different donor polymers, considerably lower reflection and parasitic absorption are found in the ST solar cells as compared to solar cells in the standard geometry with an ITO/PEDOT:PSS anode and a LiF/Al cathode. The ST solar cells have remarkably high internal quantum efficiency at short circuit condition (∼90%) and high transmittance (∼50%). Hence, efficient ST tandem solar cells with enhanced power conversion efficiency (PCE) compared to a single ST solar cell can be constructed by connecting the stacked two ST sub‐cells in parallel. The total loss of photons by reflection, parasitic absorption and transmission in the ST tandem solar cell can be smaller than the loss in a standard solar cell based on the same active materials. We demonstrate this by stacking five separately prepared ST cells on top of each other, to obtain a higher photocurrent than in an optimized standard solar cell.
Development of a novel chemiluminescence method for the determination of cefazolin sodium in injectable powder and human urine based on a luminol‐Cu(III) complex reaction in alkaline medium
Authors: Sun Hanwen , Wang Juan , Wang Ting 
Published: July 2012

ABSTRACTA novel chemiluminescence (CL) method was developed for the determination of cefazolin sodium based on the CL reaction between the [Cu(HIO6)2]5‐Cu(III) complex and luminol in alkaline solution. Results showed that CL emission of Cu(III) complex–luminol in alkaline medium was significantly different from that in acidic medium. A possible mechanism of the enhanced effect of cefazolin on CL emission of the [Cu(HIO6)2]5‐‐ luminol system was proposed. The effect of the reaction conditions on CL emissions was examined. Under optimized conditions, a good linear relationship was obtained between CL intensity and concentrations of cefazolin sodium in the range of 2.0 x 10‐8 to 2.0 x 10‐6 g/mL with a correlation coefficient of R2 = 0.9978. The limit of detection was 4.58 x 10‐9 g/mL. The proposed method was applied for the determination of cefazolin sodium in real samples with recoveries of 82.0‐109% with an RSD of 0.7‐2.1%. The proposed method was successfully used for the determination of cefazolin sodium in injectable powder preparations and human urine with satisfactory results. Copyright © 2012 John Wiley & Sons, Ltd.
Evaluation of the Effectiveness of Different Methods for the Remediation of Contaminated Groundwater by Determining the Petroleum Hydrocarbon Content
Authors: Voyevoda Maryna , Geyer Wolfgang , Mosig Peter , Seeger Eva M. , Mothes Sibylle 
Published: July 2012

AbstractThe effectiveness of different remediation procedures for decreasing the amount of TPH (total petroleum hydrocarbons) in contaminated groundwater was evaluated at the site of a former refinery. The investigations were carried out on samples taken from several gravel based HSSF (horizontal subsurface flow) constructed wetlands (CW) which differed in relation to their filter material additives (no additive, charcoal, and ferric oxides additives) and examined the potential effect of these additives on the overall treatment efficiency. Samples of the following gravel based HSSF CW were investigated. No filter additive (system A), 0.1% activated carbon (system B), 0.5% iron(III) hydroxide (system C), and the reference (system D). Systems A–C were planted with common reed (Phragmites australis), whereas system D remained unplanted. In addition, the influence of seasonal conditions on the reduction of these hydrocarbons and the correlation between the amounts of TPH and BTEX (benzene, toluene, ethylbenzene, and xylene isomers), on the one hand, and methyl tert‐butyl ether, on the other, was investigated. The study was carried out by using a modified GC‐FID approach and multivariate methods. The investigations carried out in the first year of operation demonstrated that the effectiveness of the petroleum hydrocarbon removal was highest and reached a level of 93 ± 3.5% when HSSF filters with activated carbon as a filter additive were used. This remediation method allowed the petroleum hydrocarbon content to be reduced independently of seasonal conditions. The correlation between the reduction of TPH and BTEX was found to be R = 0.8824. Using this correlation coefficient, the time‐consuming determination of the BTEX content was no longer necessary.
Adaptive radiation in extremophilic Dorvilleidae (Annelida): diversification of a single colonizer or multiple independent lineages?
Authors: Thornhill Daniel J. , Struck Torsten H. , Ebbe Brigitte , Lee Raymond W. , Mendoza Guillermo F. , Levin Lisa A. , Halanych Kenneth M. 
Published: July 2012

AbstractMetazoan inhabitants of extreme environments typically evolved from forms found in less extreme habitats. Understanding the prevalence with which animals move into and ultimately thrive in extreme environments is critical to elucidating how complex life adapts to extreme conditions. Methane seep sediments along the Oregon and California margins have low oxygen and very high hydrogen sulfide levels, rendering them inhospitable to many life forms. Nonetheless, several closely related lineages of dorvilleid annelids, including members of
Ophryotrocha, Parougia, and
Exallopus, thrive at these sites in association with bacterial mats and vesicomyid clam beds. These organisms are ideal for examining adaptive radiations in extreme environments. Did dorvilleid annelids invade these extreme environments once and then diversify? Alternatively, did multiple independent lineages adapt to seep conditions? To address these questions, we examined the evolutionary history of methane‐seep dorvilleids using 16S and Cyt b genes in an ecological context. Our results indicate that dorvilleids invaded these extreme habitats at least four times, implying preadaptation to life at seeps. Additionally, we recovered considerably more dorvilleid diversity than is currently recognized. A total of 3 major clades (designated “
Ophryotrocha,” “Mixed Genera” and “
Parougia”) and 12 terminal lineages or species were encountered. Two of these lineages represented a known species,
Parougia oregonensis, whereas the remaining 10 lineages were newly discovered species. Certain lineages exhibited affinity to geography, habitat, sediment depth, and/or diet, suggesting that dorvilleids at methane seeps radiated via specialization and resource partitioning.
Song convergence in multiple urban populations of silvereyes (Zosterops lateralis)
Authors: Potvin Dominique A. , Parris Kirsten M. 
Published: July 2012

AbstractRecent studies have revealed differences between urban and rural vocalizations of numerous bird species. These differences include frequency shifts, amplitude shifts, altered song speed, and selective meme use. If particular memes sung by urban populations are adapted to the urban soundscape, “urban‐typical” calls, memes, or repertoires should be consistently used in multiple urban populations of the same species, regardless of geographic location. We tested whether songs or contact calls of silvereyes (Zosterops lateralis) might be subject to such convergent cultural evolution by comparing syllable repertoires of geographically dispersed urban and rural population pairs throughout southeastern Australia. Despite frequency and tempo differences between urban and rural calls, call repertoires were similar between habitat types. However, certain song syllables were used more frequently by birds from urban than rural populations. Partial redundancy analysis revealed that both geographic location and habitat characteristics were important predictors of syllable repertoire composition. These findings suggest convergent cultural evolution: urban populations modify both song and call syllables from their local repertoire in response to noise.
Purposive versus random sampling for map validation: a case study on ecotope maps of floodplains in the Netherlands
Authors: Knotters M. , Brus D. J. 
Published: July 2012

ABSTRACTThe quality of ecotope maps of five districts of main water courses in the Netherlands was assessed on the basis of independent validation samples of field observations. The overall proportion of area correctly classified, and user's and producer's accuracy for each map unit were estimated. In four districts, the validation samples were selected purposively in the past. For the fifth district, a stratified two‐stage probability sample was designed, such that the spatial pattern resembles that of the purposive samples. For the purposively sampled districts, measures of map quality were estimated following a model‐based approach, using a model for the spatial variation of classification errors. For the randomly sampled district, measures of map quality were obtained following a design‐based approach, using the inclusion probabilities of the sampling points. The overall proportions of area correctly classified vary from 61% to 76%. Both user's and producer's accuracies show large variation among the map units. Model‐based predictions of producer's accuracies from two models differed strongly, indicating that with the model‐based approach the validation results strongly depend on model assumptions. We demonstrate that stratified two‐stage random sampling answers to the same practical and budgetary constraints as purposive sampling. Stratified two‐stage sampling combined with a design‐based estimation method results in model‐free estimates of the overall proportion of area correctly classified, user's and producer's accuracies. This means that the inferential validity of the estimated overall proportion of area correctly classified and user's and producer's accuracies is rigorously established if a design‐based approach is followed. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis of five and six‐membered cyclic glycerilic carbonates bearing exocyclic urethane functions
Authors: Nohra Bassam , Candy Laure , Blanco Jean‐François , Raoul Yann , Mouloungui Zephirin 
Published: July 2012

AbstractFive (5CGC) and six (6CGC) membered cyclic glycerilic carbonates having exocyclic urethane functions, as potential monomers for polyurethanes and polycarbonates, were prepared by two different routes: “two‐steps” and the “one‐pot” synthesis. For the “two‐steps” route, based on the consecutive aminolysis and transesterification reactions, a catalyst screening has been performed. Phosphazene showed the best catalytic activity and provided 5CGC and 6CGC in appreciable amounts whereas the other catalysts favored 5CGC formation. An increase in molar ratio of dimethyl carbonate (DMC) increased the yield and the conversion. In the “one‐pot” synthesis, where aminolysis and transesterification were simultaneous, a competition between products formation was demonstrated. In addition to the formation of mono‐hydroxyurethanes and glycerilic cyclic carbonates (5CGC and 6CGC), the fast aminolysis of 6CGC and the slower aminolysis of 5CGC was responsible for a partial di‐hydroxyurethanes production. The controlled and combined effects of catalyst and DMC excess acting as solvent and reagent allowed to selectively controlling the aminolysis and the transesterification reactions. The same reaction conditions were used for the synthesis of bicyclic carbonates. These new molecules enriched with urethane functions, provided novel and more environmentally friendly synthons for the synthesis of polyurethanes without the use of phosgene or isocyanate.
Convergent Synthesis of Glycodendropeptides by Click Chemistry Approaches
Authors: Kowalczyk Wioleta , Mascaraque Ainhoa , Sánchez‐Navarro Macarena , Rojo Javier , Andreu David 
Published: July 2012

AbstractMannosylation facilitates the uptake of immunogenic peptides by antigen‐processing cells expressing mannose receptors at their surface. Mannose‐receptor interactions not only induce internalization but also trigger strong T‐cell stimulation, such as that of the dendritic cell‐specific intercellular ICAM‐3 grabbing non‐integrin (DC‐SIGN), a lectin that plays a key role in the immune response against different pathogens. We describe here two efficient synthetic strategies for structurally well‐defined mannose‐displaying glycodendropeptides with up to 16 peptide and 9 mannose copies. Our approaches integrate previously optimized synthetic methods for producing both peptide and glycan dendrimers, and make extensive use of CuI‐catalyzed Huisgen 1,3‐dipolar cycloaddition for both the building of the glycodendron moieties and their subsequent conjugation to the peptide components. These strategies are versatile and straightforward enabling full control of chemical structure as well as readily tunable valency.
Unambiguous Characterization of the Sesquiterpene (7R,9E)‐1,2,11‐Trihydroxy‐1,3,5,9‐bisabolatetraene through Its Enantioselective Synthesis
Authors: Serra Stefano , Fronza Giovanni 
Published: July 2012

AbstractThe bisabolane sesquiterpene (7R,9E)‐1,2,11‐trihydroxy‐1,3,5,9‐bisabolatetraene previously extracted from Commiphora kua resins was prepared by enantioselective synthesis using an enzyme‐mediated resolution procedure as the key step. Both the chemical structure and the absolute configuration were unambiguously assigned, although the comparison of the obtained analytical data with those previously reported for the isolated terpene indicated a possible error in the characterization of the natural product. A further study on the chemical stability of the aforementioned compound revealed that it is very unstable in an acidic environment, where it cyclizes readily to give the corresponding chromane derivatives.
Nitrogen‐ and Oxygen‐Enriched Carbon With Square Tubular Structure Prepared From Polyaniline as Electrode for Supercapacitors
Authors: Xiang X. , Liu E. , Wu Y. , Tian Y. , Xie H. , Wu Z. , Zhu Y. 
Published: July 2012

AbstractSquare tubular carbon with a large number of surface functional groups are prepared by carbonizing and activating polyaniline, which are synthesized by polymerization of aniline with a template‐free self‐assembly method in aqueous media. The physicochemical properties of the square tubular carbon is characterized by scanning and transmission electron microscopy, Brunauer–Emmett–Teller surface area measurements, Raman spectroscopy, and X‐ray photoelectron spectroscopy measurements. When used as an electrode, the square tubular carbon exhibit a specific capacitance of 223 F g–1 at a scan rate of 2 mV s–1, which could still stay over 90% when the scan rate increased by 10 times. The specific capacitance even hardly decrease at a current density of 3 A g–1 after 10,000 cycles, which indicates that the square tubular carbon have good cycle durability and may be a promising candidate as an electrode for supercapacitors.
Raman investigation of artificial patinas on recent bronze‒part II: urban rain exposure
Authors: Kosec Tadeja , Ropret Polonca , Legat Andraž 
Published: July 2012

Patinas form spontaneously on copper and high copper alloys when exposed to humidity and air. They usually protect the underlying metal from corrosion. Bronze is often chemically patinated by artists to achieve an antique appearance. However, in the case of chemical patinations on bronze, there is a lack of studies about their change over time during exposure to different types of environments.Recent types of bronze, brown patina and two green type patinas (green chloride and green nitrate patina) applied over a brown patina, were selected for testing. The aim of the present study was to monitor the transformation process of chemically formed patinas and of the bronze itself after exposure to simulated urban acid rain, for a period of 35 days. The structures of the patina and corrosion products were characterized by scanning electron microscopy (SEM) and Raman spectroscopy.Three differently coloured patinas were scraped off from the bronze statue of the poet France Prešeren, two green type patinas and one brown type, to predict the probable influences of the environment, the base alloy and previously used patination techniques. Copyright © 2012 John Wiley & Sons, Ltd.
Investigations Into Amphiphilic Chitosan: Properties and Availability of Original and Newly Introduced Functional Groups
Authors: Fasl Hubert , Zemljič Lidija Fras , Goessler Walter , Stana‐Kleinschek Karin , Ribitsch Volker 
Published: July 2012

AbstractThe accessibility of functional groups of 3,6‐O‐chitosansulfate in water is studied using conductometric and polyelectrolyte titration techniques. These studies reveal the good accessibility of protonated amino groups following conductometric titrations and pH dependency on the accessibility of negatively charged sulfate groups following polyelectrolyte titrations. In addition, the influence of negatively charged sulfate groups, introduced onto polymer backbone by synthesis, is analyzed regarding the well‐known antimicrobial activities of chitosan. The assessment of the mortality rates of Gram‐negative, Gram‐positive bacteria, and pathogenic fungi reveal that sulfate groups in chitosan lead to a tremendous loss in antimicrobial activity compared with nonmodified chitosan.
Oligoepoxide‐Based Monoliths: Synthesis and Application as Affinity Capillary Column for Enrichment of Immunoglobulin G
Authors: Pecher Heike S. , Zimathies Annett , Weller Michael G. 
Published: July 2012

AbstractA series of new epoxide‐based monoliths is synthesized by self‐polymerization of polyglycerol polyglycidyl ether as porous support for affinity chromatography. Porosity and mean pore sizes are investigated as a function of the porogen ratio and analyzed by mercury porosimetry. The morphologies are visualized by environmental scanning electron microscope. With a particularly rigid monolith prepared with 75 vol% porogen (66% porosity and 12 μm mean pore size), a capillary column (0.5 mm ID) is prepared and directly functionalized with recombinant protein A to extract immunoglobulin G from rabbit serum.
Synthesis and characterization of the novel meta‐modified aramid fibers with liquid crystalline properties
Authors: Jin Hui , Wang Yiyong 
Published: July 2012

AbstractTo improve the interfacial adhesion between the meta‐aramid fibers and the matrix, the new method of interfacial polymerization was used to complete the aramid's surface modification. Two new kinds of grafted fibers which had liquid crystalline properties were prepared. The structure and properties of the aramid fibers before and after modification were characterized by scanning electron microscope (SEM), Fourier transform infrared, differential scanning calorimetry, and polarizing optical microscope. The surface of grafted aramid fibers was very rough. The range of liquid crystalline phase of the grafted fibers AF‐1 and AF‐2 on the cooling scan, respectively, is from 147 to 209°C and from 163 to 221°C. It was novel that the grafted fibers with rigid‐rod structure had typical nematic texture. The grafted aramid fibers as the ideal substitute material of asbestos were used as reinforcing fibers in nitrile butadiene rubber (NBR) matrix. Combining with NBR, the composites reinforced with the unmodified and grafted aramid fibers were synthesized. The micrographs of the composites' fractured surface were studied by SEM. The mechanical properties of the grafted fibers/NBR composites were superior to the unmodified fibers/NBR composites. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Risk of Guillain–Barré syndrome after meningococcal conjugate vaccination
Authors: Velentgas Priscilla , Amato Anthony A. , Bohn Rhonda L. , Arnold Chan K. , Cochrane Thomas , Funch Donnie P. , Dashevsky Inna , Duddy April L. , Gladowski Patricia , Greenberg Steven A. , Kramer Judith M. , McMahill‐Walraven Cheryl , Nakasato Cynthia , Spettell Claire M. , Syat Beth L. , Wahl Peter M. , Walker Alexander M. , Zhang Fang , Brown Jeffrey S. , Platt Richard 
Published: July 2012

ABSTRACTPurposeA new meningococcal conjugate vaccine (MCV4) was introduced in 2005. Shortly after, case reports of Guillain–Barré syndrome (GBS), a serious demyelinating disease, began to be reported to the Vaccine Adverse Event Reporting System. In 2006, the Centers for Disease Control and Prevention and the Food and Drug Administration requested the evaluation of GBS risk after MCV4 vaccination. We conducted a study to assess the risk of GBS after MCV4 vaccination using health plan administrative and claims data together with the review of primary medical records of potential cases.MethodsRetrospective cohort study among 12.6 million 11‐ to 21‐year‐old members of five US health plans with a total membership of 50 million. Automated enrollment and medical claims data from March 2005 through August 2008 were used to identify the population, the vaccinations administered, and the medical services associated with possible GBS. Medical records were reviewed and adjudicated by a neurologist panel to confirm cases of GBS. The study used distributed data analysis methods that minimized sharing of protected health information.ResultsWe confirmed 99 GBS cases during 18,322,800 person‐years (5.4/1,000,000 person‐years). More than 1.4 million MCV4 vaccinations were observed. No confirmed cases of GBS occurred within 6 weeks after vaccination. The upper 95% CI for the attributable risk of GBS associated with MCV4 is estimated as 1.5 cases per 1,000,000 doses.ConclusionsAmong members of five US health plans, MCV4 vaccination was not associated with increased GBS risk. Copyright © 2012 John Wiley & Sons, Ltd.