bluuebunny/crossref_metadata_2025 huggingface dataset:
Transcatheter removal of atrial septal stent placed to decompress left atrium with VA ECMO
Authors: Veeram Reddy Surendranath Reddy , Guleserian Kristine J. , Nugent Alan W.
Published: January 2015

Left atrial (LA) decompression in infants with thick atrial septum placed on veno‐arterial extracorporeal membrane oxygenation (ECMO) can be reliably achieved with transcatheter atrial septal (AS) stent placement. However, with myocardial recovery and ECMO decannulation the stent causes a permanent left to right shunt and surgical removal of the AS stent is usually accomplished. Transcatheter removal of AS stent is an attractive option as the advantages of LA decompression would then be coupled with the advantage of avoiding a sternotomy for surgical removal of the stent. To our knowledge, this is the first reported case of successful transcatheter retrieval of AS stent used for LA decompression in a 13‐month‐old child. © 2015 Wiley Periodicals, Inc.
Longer‐term outcome of perventricular device closure of muscular ventricular septal defects in children
Authors: Kang Sok Leng , Tometzki Andrew , Caputo Massimo , Morgan Gareth , Parry Andrew , Martin Robin
Published: January 2015

Objective

To describe the longer‐term clinical experience and follow‐up with perventricular device closure of ventricular septal defects (VSD) in children.

Methods

Between January 2005 and December 2013, muscular ventricular septal defect closure with the Amplatzer Muscular VSD Occluder was undertaken using a hybrid perventricular approach. Data including demographic, echocardiographic parameter, and clinical outcome were reviewed retrospectively.

Results

Median age at the time of procedure was 8.9 months (range 1.9–31.0 months) and median weight was 6.6 kg (range 4.5–12.9 kg). All had a moderate to large muscular VSD, three had more than one VSD, four had previous coarctation repair, and five had previous pulmonary artery (PA) banding. A single Amplatzer muscular occluder (range 8–18 mm) was deployed in each patient without cardiopulmonary bypass under echocardiographic guidance. Two of ten patients subsequently required a short period of cardiopulmonary bypass for reconstruction of PA after de‐banding and closure of atrial septal defect in one. Occluder removal was necessary in one patient due to entrapment of the tricuspid valve and progressive tricuspid regurgitation. This patient underwent surgical repair with a good result and no device‐related valve damage. In the remaining nine patients, no severe complications such as device embolization, arrhythmia, or significant valve regurgitation were noted in the post‐operative period or follow‐up. At a median time of 6.5 years (range 0.9–8.4 years) post device implantation, complete closure was achieved in five patients and four had small residual leaks, which were not hemodynamically significant.

Conclusion

Perventricular muscular VSD closure is effective in small children with suitable muscular defects and may avoid the morbidity associated with cardiopulmonary bypass and conventional surgical repair. There have been no late complications with this approach. © 2015 Wiley Periodicals, Inc.
Multicenter evaluation of transcatheter aortic valve replacement using either SAPIEN XT or CoreValve: Degree of device oversizing by computed‐tomography and clinical outcomes
Authors: Dvir Danny , Webb John G. , Piazza Nicolo , Blanke Philipp , Barbanti Marco , Bleiziffer Sabine , Wood David A. , Mylotte Darren , Wilson Alex B. , Tan John , Stub Dion , Tamburino Corrado , Lange Rudiger , Leipsic Jonathon
Published: January 2015

Objective

To analyze the association between computed‐tomography‐derived degrees of device oversizing and clinical outcomes during transcatheter aortic valve replacement (TAVR).

Background

Previous reports suggest that different devices reach optimal results with different degrees of device oversizing. Therefore, similar sized devices of different types (SAPIEN XT and CoreValve) may be favored in different annular ranges and a case considered borderline between two sizes of a specific device might be within a favorable range of another.

Methods and Results

A multicenter registry of 615 consecutive transfemoral TAVR procedures using either SAPIEN XT or CoreValve was analyzed. A first group of 190 patients had annular sizes for which only moderate oversizing degree was feasible (5–20% by area or 2.5–9.5% by perimeter). A second group included 178 patients that had annulus size for which only large oversizing degree was feasible (20.1–35% by area or 9.6–16.2% by perimeter). In the “only large oversizing feasible group” there were more annular rupture events in patients treated by SAPIEN XT valve as compared to those treated by CoreValve (3.4% vs. 0%, P = 0.04). In the “only moderate oversizing feasible group”, those treated by CoreValve had more post balloon dilatation and 30‐day major stroke in comparison with those treated by SAPIEN XT (16.1% vs. 7.7%, P = 0.04 and 8% vs. 1.3%, P = 0.02, respectively).

Conclusions

Optimal clinical performance of CoreValve and SAPIEN XT appears to be reached with different degrees of oversizing. Certain annular sizes that allow for only moderate or large oversizing, but not both, appear to benefit from a device specific approach. © 2015 Wiley Periodicals, Inc.
Middle‐term results of trans‐catheter creation of atrial communication in patients receiving mechanical circulatory support
Authors: O'Byrne Michael L. , Glatz Andrew C. , Rossano Joseph W. , Schiavo Kellie L. , Dori Yoav , Rome Jonathan J. , Gillespie Matthew J.
Published: January 2015

Objective

To describe our center's middle‐term outcomes following trans‐catheter creation of atrial communication (ASD) in patients on mechanical circulatory support. Background: Trans‐catheter creation of an ASD in patients on mechanical circulatory support is an adjuvant therapy to reduce left atrial pressure and associated morbidity. Data on middle term outcomes following this procedure, specifically in regards to the fate of the ASD, are limited.

Methods

Retrospective observational study of consecutive children and adults undergoing trans‐catheter creation of an atrial septal communication between 1/1/2006 and 5/1/2014, reviewing their baseline characteristics, procedural details, and data from follow‐up.

Results

Over the study period, 37/227 (16%) subjects undergoing veno‐arterial extra‐corporeal membrane oxygenation (VA‐ECMO) underwent trans‐catheter creation of an atrial communication. Mortality on VA‐ECMO support in this subgroup was 19%, with an additional 24% transitioning to ventricular assist device. Of the 57% who survived to separation from VA‐ECMO, 16/21 (76%) had residual atrial communications. 56% of these underwent closure procedures.

Conclusions

Following trans‐catheter creation of ASD, a residual ASD is present in the majority of assessable survivors and represents a potential volume overload and/or right to left shunt that may need to be addressed. © 2015 Wiley Periodicals, Inc.
Palladium Nanoparticles Supported on Fibrous‐Structured Silica Nanospheres (KCC‐1): An Efficient and Selective Catalyst for the Transfer Hydrogenation of Alkenes
Authors: Qureshi Ziyauddin S. , Sarawade Pradip B. , Albert Matthias , D'Elia Valerio , Hedhili Mohamed N. , Köhler Klaus , Basset Jean‐Marie
Published: January 2015

An efficient palladium catalyst supported on fibrous silica nanospheres (KCC‐1) has been developed for the hydrogenation of alkenes and α,β‐unsaturated carbonyl compounds, providing excellent yields of the corresponding products with remarkable chemoselectivity. Comparison (high‐resolution TEM, chemisorption) with analogous mesoporous (MCM‐41, SBA‐15) silica‐supported Pd nanocatalysts prepared under identical conditions, demonstrates the advantage of employing the fibrous KCC‐1 morphology versus traditional supports because it ensures superior accessibility of the catalytically active cores along with excellent Pd dispersion at high metal loading. This morphology ultimately leads to higher catalytic activity for the KCC‐1‐supported nanoparticles. The protocol developed for hydrogenation is advantageous and environmentally benign owing to the use of HCOOH as a source of hydrogen, water as a solvent, and because of efficient catalyst recyclability and durability. The recycled catalyst has been analyzed by XPS spectroscopy and TEM showing only minor changes in the oxidation state of Pd and in the morphology after the reaction, thus confirming the robustness of the catalyst.
Rhodium versus Iridium Catalysts in the Controlled Tandem Hydroformylation–Isomerization of Functionalized Unsaturated Fatty Substrates
Authors: Ternel Jérémy , Couturier Jean‐Luc , Dubois Jean‐Luc , Carpentier Jean‐François
Published: January 2015

The hydroformylation of 10‐undecenitrile (1) and related unsaturated fatty substrates (H2CCH(CH2)7CH2R; R=CO2Me, CH2Br, CHO) has been studied with rhodium, iridium, ruthenium, and palladium biphephos catalysts. The reactions proceeded effectively with all four systems, with high selectivities for the linear aldehyde (ratio of linear/branched aldehydes=99:1). The biphephos‐bis[chloro(cyclooctadiene)iridium] system showed a non‐optimized hydroformylation turnover frequency (TOFHF) of 770 h−1 that was only approximately 5 times lower than that of the rhodium‐based system (TOFHF=3320 h−1); the palladium and ruthenium biphephos systems were less active (TOFHF=210 and 310 h−1, respectively). Upon recycling, remarkable productivities were achieved in both cases (TON≈58 000 mol(1/1‐int) mol(Ir)−1 and 250 000 mol(1/1‐int) mol(Rh)−1, in which int=internal olefin). Competitive isomerization of terminal to internal olefins occurred with these catalysts. Iridium biphephos systems allowed slightly better control of the distribution of the internal isomers than the rhodium biphephos catalyst, with higher ratios of 9‐/8‐undecenitrile (1‐int).
Glucose Biochip Based on Flexible Carbon Fiber Electrodes: In Vivo Diabetes Evaluation in Rats
Authors: Iost Rodrigo M. , Sales Fernanda C. P. F. , Martins Marccus V. A. , Almeida Maria C. , Crespilho Frank N.
Published: January 2015

This paper reports an implantable biochip for intravenous glucose monitoring in rat blood. A key feature of this device is the combination of the flexibility of the flexible carbon fiber (FCF) electrodes for the micromanipulation of the biosensor in the implant. FCF, modified with a neutral red electrochemical mediator and an enzyme glucose oxidase, enables the biochip to be manipulated conveniently during insertion in the rat veins. For in vivo experiments, the biochip is inserted into the jugular vein of a living rat (Rattus novergicus) using a poly(propylene) catheter. The capability for in vivo glucose detection is evaluated with a normal concentration of glucose (30 mg dL−1) and with a diabetic simulation (200 mg dL−1). Through electrochemical data, this type of biochip can distinguish different concentration of glucose in the blood of the animal. The biochip showed promise performance for future applications of implantable bioelectronics devices.
Asymmetric Supercapacitors Based on Activated‐Carbon‐Coated Carbon Nanotubes
Authors: Shi Kaiyuan , Zhitomirsky Igor
Published: January 2015

A new method is developed for the fabrication of asymmetric supercapacitor devices containing fibrous electrode materials. The approach is based on the synthesis of uniform polypyrrole (PPy) coatings on multiwalled carbon nanotubes (MWCNT), which were used for the fabrication of MWCNTs coated with N‐doped activated carbon (N‐AC). The N‐AC‐MWCNT electrodes show good electrochemical performance in positive and negative potential windows. The electrochemical performance of positive electrodes is further enhanced by the development of MnO2‐coated N‐AC‐MWCNT. In this approach, the problem of MWCNT degradation in the reaction with KMnO4 is avoided by the use of a sacrificial N‐AC layer, which allows a relatively high mass content of MnO2 in the final material. The approach offers the advantages of small size of MnO2 nanoparticles, good electrical contact of MnO2 and MWCNT and fibrous microstructure of the material. Testing results show a remarkably high specific capacitance of 6.29 F cm−2 (311.7 F g−1) at a mass loading of 20 mg cm−2. The important finding is the possibility to fabricate asymmetric devices, which show a specific capacitance of 2.19 F cm−2 (62.7 F g−1) in a voltage window of 1.9 V in aqueous Na2SO4 electrolyte, an energy density of 26.4 mWh g−1 and a power density of 1.7 W g−1. The electrodes and devices show good capacitance retention at high charge–discharge rates and good cycling stability. The asymmetric capacitors developed herein are promising for practical energy‐storage applications.
Probing Structure Modification of Palladium Nanomaterials during Chemical Synthesis by using In Situ X‐ray Diffraction: Electrochemical Properties
Authors: Holade Yaovi , Napporn Teko W. , Morais Claudia , Servat Karine , Kokoh K. Boniface
Published: January 2015

Experimental evidence for Pd‐based structure modification of electrocatalysts with hydrogen during their chemical synthesis is still missing. Therefore, in situ X‐ray diffraction (XRD) techniques were as used to investigate hydrogen insertion into the lattice of Pd nanomaterials during their preparation. It was shown that the use of NaBH4as reducing agent led to PdHxwhereasL‐ascorbic acid gave Pd nanoparticles. The subsequent influence of hydrogen insertion on the catalytic properties of Pd nanostructures was demonstrated by using carbon monoxide and glucose as probing molecules. High active surface areas and catalytic activities were found for the unmodified Pd nanostructures through electrochemical studies. Notably, the reducing agent has a significant effect on the size distribution of the nanoparticles. Its use can precisely and effectively tune their catalytic properties. Consequently, the remarkable behavior uncovered herein provides new strategic routes that can be used for the preparation of Pd‐based nanomaterials.
Facile Synthesis of Mesoporous MoS2‐TiO2 Nanofibers for Ultrastable Lithium Ion Battery Anodes
Authors: Zhuang Wei , Li Licheng , Zhu Jiahua , An Rong , Lu Linghong , Lu Xiaohua , Wu Xinbing , Ying Hanjie
Published: January 2015

TiO2 hybrid nanocomposites are promising electrode materials for lithium‐ion batteries because of the large specific capacity, excellent rate capability, and high cycling stability. We have developed an effective facile incipient wetness impregnation method that can be used to fabricate novel mesoporous MoS2–TiO2 fibrous nanocomposites. The MoS2–TiO2 nanocomposites exhibited notable electrochemical performance with a high capacity of 120 mA h g−1 at a rate of 40 C and long‐term, stable capacity of 124 mA h g−1 with a capacity retention of 75.2 % after 1000 cycles. These results suggest that the structure of mesoporous TiO2 nanofibers composited with a thin, uniform, well‐dispersed MoS2 layer improve the rate performance and cycling stability. Such good performance may be derived from the dispersed MoS2 layer, which accelerates the surface electrochemical reactions and offers a stable structure.
Controlled Synthesis of Nanoporous Nickel Oxide with Two‐Dimensional Shapes through Thermal Decomposition of Metal–Cyanide Hybrid Coordination Polymers
Authors: Zakaria Mohamed B. , Hu Ming , Salunkhe Rahul R. , Pramanik Malay , Takai Kimiko , Malgras Victor , Choi Seyong , Dou Shi Xue , Kim Jung Ho , Imura Masataka , Ishihara Shinsuke , Yamauchi Yusuke
Published: January 2015

The urgent need for nanoporous metal oxides with highly crystallized frameworks is motivating scientists to try to discover new preparation methods, because of their wide use in practical applications. Recent work has demonstrated that two‐dimensional (2D) cyanide‐bridged coordination polymers (CPs) are promising materials and appropriate for this purpose (Angew. Chem. Int. Ed.­ 2013, 52, 1235). After calcination, 2D CPs can be transformed into nanoporous metal oxides with a highly accessible surface area. Here, this strategy is adopted in order to form 2D nanoporous nickel oxide (NiO) with tunable porosity and crystallinity, using trisodium citrate dihydrate as a controlling agent. The presence of trisodium citrate dihydrate plays a key role in the formation of 2D nanoflakes by controlling the nucleation rate and the crystal growth. The size of the nanoflakes gradually increases by augmenting the amount of trisodium citrate dihydrate in the reaction. After heating the as‐prepared CPs in air at different temperatures, nanoporous NiO can be obtained. During this thermal treatment, organic units (carbon and nitrogen) are completely removed and only the metal content remains to take part in the formation of nanoporous NiO. In the case of large‐sized 2D CP nanoflakes, the original 2D flake‐shapes are almost retained, even after thermal treatment at low temperature, but they are completely destroyed at high temperature because of further crystallization in the framework. Nanoporous NiO with high surface area shows significant efficiency and interesting results for supercapacitor application.
Experimental and Computational Studies on the CH Amination Mechanism of Tetrahydrocarbazoles via Hydroperoxides
Authors: Gulzar Naeem , Jones Kevin Mark , Konnerth Hannelore , Breugst Martin , Klussmann Martin
Published: January 2015

The acid‐catalyzed reactions of photochemically generated tetrahydrocarbazole peroxides with anilines have been studied experimentally and computationally to identify the underlying reaction mechanism. The kinetic data indicate a reaction order of one in the hydroperoxide and zero in the aniline. Computational investigations using density functional theory support the experimental findings and predict an initial tautomerization between an imine and enamine substructure of the primarily generated tetrahydrocarbazole peroxide to be the rate controlling step. The enamine tautomer then loses hydrogen peroxide upon protonation, generating a stabilized allylic carbocation that is reversibly trapped by solvent or aniline to form the isolated products.
Micro‐/Nanostructured Multicomponent Molecular Materials: Design, Assembly, and Functionality
Authors: Yan Dongpeng
Published: January 2015

Molecule‐based micro‐/nanomaterials have attracted considerable attention because their properties can vary greatly from the corresponding macro‐sized bulk systems. Recently, the construction of multicomponent molecular solids based on crystal engineering principles has emerged as a promising alternative way to develop micro‐/nanomaterials. Unlike single‐component materials, the resulting multicomponent systems offer the advantages of tunable composition, and adjustable molecular arrangement, and intermolecular interactions within their solid states. The study of these materials also supplies insight into how the crystal structure, molecular components, and micro‐/nanoscale effects can influence the performance of molecular materials. In this review, we describe recent advances and current directions in the assembly and applications of crystalline multicomponent micro‐/nanostructures. Firstly, the design strategies for multicomponent systems based on molecular recognition and crystal engineering principles are introduced. Attention is then focused on the methods of fabrication of low‐dimensional multicomponent micro‐/nanostructures. Their new applications are also outlined. Finally, we briefly discuss perspectives for the further development of these molecular crystalline micro‐/nanomaterials.
Regulation of Charge Delocalization in a Heteronuclear Fe2Ru System by a Stepwise Photochromic Process
Authors: Xu Guang‐Tao , Li Bin , Wang Jin‐Yun , Zhang Dao‐Bin , Chen Zhong‐Ning
Published: January 2015

Heteronuclear complexes FeCp2DTECCRu(dppe)2Cl (1 o; dppe=1,2‐bis(diphenylphosphino)ethane, Cp=cyclopentadienyl, DTE=dithienylethene) and FeCp2DTECCRu(dppe)2CCDTEFeCp2 (2 oo), with redox‐active ferrocenyl and ruthenium centers separated by a photochromic DTE moiety, were prepared to achieve photoswitchable charge delocalization and Fe⋅⋅⋅Ru electronic communication. Upon UV‐light irradiation of 2 oo, the Fe⋅⋅⋅Ru heterometallic electronic interaction is increasingly facilitated with stepwise photocyclization, 2 oo→2 co→2 cc; this is ascribed to the gradual increase in π‐conjugated systems. The near‐infrared absorptions in mixed‐valence species [2 oo]+/[2 co]+/[2 cc]+ are gradually intensified following the conversion of [2 oo]+→[2 co]+→[2 cc]+, which demonstrates that the extent of charge delocalization shows progressive enhancement with stepwise photocyclization. As revealed by electrochemical, spectroscopic, and theoretical studies, complex 2 exhibits nine switchable states through stepwise photochromic and reversible redox processes.
Masked Unsaturated Esters/Amides in Asymmetric Organocatalysis
Authors: Monge David , Jiang Hao , Alvarez‐Casao Yolanda
Published: January 2015

This Concept article summarizes strategies and developments regarding the use of masked unsaturated esters/amides in asymmetric organocatalysis. Useful substrates are categorized by the design of their inherent carboxylate template. This template group not only enables their functionality as ester surrogates, but also define their accessibilities, modes of interactions with catalysts and the simplicity with which they transform back to the parent carboxylates. Both covalent and noncovalent catalytic systems are discussed and examples showing the entire process (from substrates‐to‐functionalized ester/amides) are given.
Three‐Dimensional Fe2N@C Microspheres Grown on Reduced Graphite Oxide for Lithium‐Ion Batteries and the Li Storage Mechanism
Authors: Yu Peng , Wang Lei , Sun Fanfei , Zhao Dongdong , Tian Chungui , Zhao Lu , Liu Xu , Wang Jianqiang , Fu Honggang
Published: January 2015

Nanostructured iron compounds as lithium‐ion‐battery anode material have attracted considerable attention with respect to improved electrochemical energy storage and excellent specific capacity, so lots of iron‐based composites have been developed. Herein, a novel composite composed of three‐dimensional Fe2N@C microspheres grown on reduced graphite oxide (denoted as Fe2N@C‐RGO) has been synthesized through a simple and effective technique assisted by a hydrothermal and subsequent heating treatment process. As the anode material for lithium‐ion batteries, the synthetic Fe2N@C‐RGO displayed excellent Li+‐ion storage performance with a considerable initial capacity of 847 mAh g−1, a superior cycle stability (a specific discharge capacity of 760 mAh g−1 remained after the 100th cycle), and an improved rate‐capability performance compared with those of the pure Fe2N and Fe2N‐RGO nanostructures. The good performance should be attributed to the existence of RGO layers that can facilitate to enhance the conductivity and shorten the lithium‐ion diffusion path; in addition, the carbon layer on the surface of Fe2N can avert the structure decay caused by the volume change during the lithiation/delithiation process. Moreover, in situ X‐ray absorption fine‐structure analysis demonstrated that the excellent performance can be attributed to the lack of any obvious change in the coordination geometry of Fe2N@C‐RGO during the charge/discharge processes.
The Influence of the Capping Agent on the Oxidation of Silver Nanoparticles: Nano‐impacts versus Stripping Voltammetry
Authors: Toh Her Shuang , Jurkschat Kerstin , Compton Richard G.
Published: January 2015

The influence of capping agents on the oxidation of silver nanoparticles was studied by using the electrochemical techniques of anodic stripping voltammetry and anodic particle coulometry (“nano‐impacts”). Five spherical silver nanoparticles each with a different capping agent (branched polyethylenimine (BPEI), citrate, lipoic acid, polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP)) were used to perform comparative experiments. In all cases, regardless of the capping agent, complete oxidation of the single nanoparticles was seen in anodic particle coulometry. The successful quantitative detection of the silver nanoparticle size displays the potential application of anodic particle coulometry for nanoparticle characterisation. In contrast, for anodic stripping voltammetry using nanoparticles drop casting, it was observed that the capping agent has a very significant effect on the extent of silver oxidation. All five samples gave a low oxidative charge corresponding to partial oxidation. It is concluded that the use of anodic stripping voltammetry to quantify nanoparticles is unreliable, and this is attributed to nanoparticle aggregation.
Gold‐Catalyzed Multiple Cascade Reaction of 2‐Alkynylphenylazides with Propargyl Alcohols
Authors: Li Nan , Wang Tian‐Yi , Gong Liu‐Zhu , Zhang Liming
Published: January 2015

An unprecedented gold‐catalyzed multiple cascade reaction between 2‐alkynyl arylazides and alkynols has been developed, allowing for the step‐economical synthesis of pyrroloindolone derivatives with a wide range of structural diversity. In this reaction, the gold complex participates in triple catalysis in tandem fashion. Moreover, the efficient chirality transfer from optically pure alkynol substrates enables facile access to chiral pyrroloindolone derivatives with two stereogenic centers, including a quaternary one, with excellent levels of optical purity.
Enzymatic Resolution of α‐Methyleneparaconic Acids and Evaluation of their Biological Activity
Authors: Chakrabarty Kuheli , Defrenza Ivana , Denora Nunzio , Drioli Sara , Forzato Cristina , Franco Massimo , Lentini Giovanni , Nitti Patrizia , Pitacco Giuliana
Published: January 2015

Both enantiomers of three biologically relevant paraconic acids—MB‐3, methylenolactocin, and C75—were obtained with enantioselectivities up to 99% by kinetic enzymatic resolutions. Good enantiomeric excesses were obtained for MB‐3 and methylenolactocin, using α‐chymotrypsin and aminoacylase as enantiocomplementary enzymes, while C75 was resolved with aminoacylase. They all were evaluated for their antiproliferative, antibacterial, and antifungal activities, showing weak effects and practically no difference between enantiomers in each case. At high concentrations (16–64 µg/mL), (–)‐ C75 acted as an antimicrobial agent against Gram‐positive bacteria. Chirality 27:239–246, 2015. © 2015 Wiley Periodicals, Inc.
Entmischungsvorgänge bei Schüttgütern und ihre Simulation mit der Diskrete‐Element‐Methode
Authors: Dau Günter , Ripperger Siegfried
Published: January 2015

Ein typischer Vorgang bei der Handhabung von Schüttgütern ist das Aufhäufen eines Schüttkegels, wobei unterschiedliche Eigenschaften der Partikel zu einer Entmischung führen. Dieser Vorgang wurde an binären Kugelmischungen experimentell untersucht. Der Entmischungsgrad wurde durch eine Entmischungskennzahl charakterisiert und die Abhängigkeit von verschiedenen experimentellen Parametern dargestellt. Die Simulation des Versuches durch die Diskrete‐Elemente‐Methode gab eine gute Übereinstimmung, wenn die zugrunde gelegten Rechenparameter sinnvoll angepasst wurden.
Do mothers prefer helpers or smaller litters? Birth sex ratio and litter size adjustment in cotton‐top tamarins (Saguinus oedipus)
Authors: Boulton Rebecca A. , Fletcher Alison W.
Published: January 2015

Sex allocation theory has been a remarkably productive field in behavioral ecology with empirical evidence regularly supporting quantitative theoretical predictions. Across mammals in general and primates in particular, however, support for the various hypotheses has been more equivocal. Population‐level sex ratio biases have often been interpreted as supportive, but evidence for small‐scale facultative adjustment has rarely been found. The helper repayment (HR) also named the local resource enhancement (LRE) hypothesis predicts that, in cooperatively breeding species, mothers invest more in the sex which assists with rearing future offspring and that this bias will be more pronounced in mothers who require extra assistance (i.e., due to inexperience or a lack of available alloparents). We tested these hypotheses in captive cotton‐top tamarins (Saguinus oedipus) utilizing the international studbook and birth records obtained through a questionnaire from ISIS‐registered institutions. Infant sex, litter size, mother's age, parity, and group composition (presence of nonreproductive subordinate males and females) were determined from these records. The HR hypothesis was supported over the entire population, which was significantly biased toward males (the “helpful” sex). We found little support for helper repayment at the individual level, as primiparous females and those in groups without alloparents did not exhibit more extreme tendencies to produce male infants. Primiparous females were, however, more likely to produce singleton litters. Singleton births were more likely to be male, which suggests that there may be an interaction between litter size adjustment and sex allocation. This may be interpreted as supportive of the HR hypothesis, but alternative explanations at both the proximate and ultimate levels are possible. These possibilities warrant further consideration when attempting to understand the ambiguous results of primate sex ratio studies so far.
Enhanced immunostimulatory activity of cyclic dinucleotides on mouse cells when complexed with a cell‐penetrating peptide or combined with CpG
Authors: Yildiz Soner , Alpdundar Esin , Gungor Bilgi , Kahraman Tamer , Bayyurt Banu , Gursel Ihsan , Gursel Mayda
Published: January 2015

Recognition of pathogen‐derived nucleic acids by immune cells is critical for the activation of protective innate immune responses. Bacterial cyclic dinucleotides (CDNs) are small nucleic acids that are directly recognized by the cytosolic DNA sensor STING (stimulator of IFN genes), initiating a response characterized by proinflammatory cytokine and type I IFN production. Strategies to improve the immune stimulatory activities of CDNs can further their potential for clinical development. Here, we demonstrate that a simple complex of cylic‐di‐GMP with a cell‐penetrating peptide enhances both cellular delivery and biological activity of the cyclic‐di‐GMP in murine splenocytes. Furthermore, our findings establish that activation of the TLR‐dependent and TLR‐independent DNA recognition pathways through combined use of CpG oligonucleotide (ODN) and CDN results in synergistic activity, augmenting cytokine production (IFN‐α/β, IL‐6, TNF‐α, IP‐10), costimulatory molecule upregulation (MHC class II, CD86), and antigen‐specific humoral and cellular immunity. Results presented herein indicate that 3′3′‐cGAMP, a recently identified bacterial CDN, is a superior stimulator of IFN genes ligand than cyclic‐di‐GMP in human PBMCs. Collectively, these findings suggest that the immune‐stimulatory properties of CDNs can be augmented through peptide complexation or synergistic use with CpG oligonucleotide and may be of interest for the development of CDN‐based immunotherapeutic agents.
Bifunctional N‐Heterocyclic Carbene Ferrocenyl Ligands – Synthesis and Palladium(II) Complexes
Authors: Loxq Pauline , Daran Jean‐Claude , Manoury Eric , Poli Rinaldo , Labande Agnès
Published: January 2015

Two ferrocenylimidazolium tetrafluoroborate salts [R = Me, 7 and R = (2,4,6‐trimethylphenyl), 8], precursors of new ferrocenylimidazol‐2‐ylidene bifunctional ligands, have been prepared for the first time. The free 1‐(2‐dimethylaminomethyl)ferrocenyl‐3‐methylimidazol‐2‐ylidene (12) was isolated and characterised by 1H and 13C NMR spectroscopy and represents the second example of an isolated and characterised imidazol‐2‐ylidene directly linked to ferrocene. Neutral (compound 13) and cationic (compound 14) palladium(II) complexes were obtained in moderate yields and characterised by 1H and 13C NMR spectroscopy and mass spectrometry.
Li14(PON3)2O – A Non‐Condensed Oxonitridophosphate Oxide
Authors: Baumann Dominik , Schnick Wolfgang
Published: January 2015

Li14(PON3)2O was synthesized by reaction of phosphoric triamide PO(NH2)3 with LiNH2 at 550 °C. It crystallizes in a trigonal structure [P$\bar {3}$ (no. 147), a = 5.6880(5), c = 8.0855(8) Å, V = 226.55(5) Å3, Z = 1] that can be described as a defect variant of the antifluorite structure type. The crystal structure was elucidated from X‐ray powder diffraction data and corroborated by FTIR and solid‐state NMR spectroscopy. Li14(PON3)2O is composed of non‐condensed PON36– tetrahedra and O2– ions that are surrounded by tetrahedrally coordinated Li+. This is the first example of an ortho‐oxonitridophosphate.
Stereocontrolled One‐Step Synthesis of Difunctionalised Cispentacin Derivatives through Ring‐Opening Metathesis of Norbornene β‐Amino Acids
Authors: Kiss Loránd , Kardos Márton , Forró Enikő , Fülöp Ferenc
Published: January 2015

Through the ring‐opening metathesis of norbornene or oxanorbornene β‐amino acids with ethylene in the presence of certain Ru catalysts, a facile and convenient stereocontrolled one‐step method was devised for the preparation of divinylated cispentacins and oxacyclic cispentacin stereoisomers with four chiral centres. The products are interesting scaffolds for peptide chemistry and for the synthesis of novel functionalised materials through olefinic bond transformations. The ring‐opening metathesis proceeds without affecting the chiral centres of the starting molecules, so that their stereochemistry was conserved and determines the configuration of the chiral centres in the products.
Carbon capture and geological storage in Brazil: an overview
Authors: Iglesias Rodrigo S. , Ketzer J. Marcelo , Melo Clarissa L. , Heemann Roberto , Machado Claudia X.
Published: January 2015

Brazil is recognized for possessing a low carbon‐intensive energy matrix, with most of its power being generated from hydroelectricity. Its greenhouse gas emissions profile is dominated by deforestation and land‐use change. Despite this characteristic, the country has been committed to the development of carbon capture and geological storage (CCS) research since this technology started to be recognized as a relevant solution for greenhouse gas emission reductions. This development has gained attention recently owing to the beginning of the production of pre‐salt reservoirs, which may contain significant amounts of CO2 in the produced fluids. The work has been carried out mostly through the efforts of the academia and industrial enterprises. This paper presents a summary and a brief description of the recent activities being carried out by these sectors, aiming to develop and promote CCS in Brazil.
There Is Enough Time
Authors: Hobson Sarah R. , Vu Julie F.
Published: January 2015

This paper draws upon an explanation of the proleptic, an understanding of time as being socially constructed within specific contexts, to interpret a series of dramatic sequences enacted in ethnodramatic pedagogy. The authors present two major arguments: (1) teachers can help students analyze the processes that influence and shape their identities by adopting a proleptic framework; (2) ethnodrama, a dramatic and dialogic approach to interpreting texts, creates an opportunity for students to evaluate the social forces that shape identity construction as they situate and reflect on texts within multiple contexts. The authors delineate the ways in which teachers can use ethnodrama to help students revise their understandings of the personal and cultural implications of texts by situating these understandings in different configurations of place, space, and time.
Cytotoxicity associated with electrospun polyvinyl alcohol
Authors: Pathan Saif G. , Fitzgerald Lisa M. , Ali Syed M. , Damrauer Scott M. , Bide Martin J. , Nelson David W. , Ferran Christiane , Phaneuf Tina M. , Phaneuf Matthew D.
Published: January 2015

Polyvinyl alcohol (PVA) is a synthetic, water‐soluble polymer, with applications in industries ranging from textiles to biomedical devices. Research on electrospinning of PVA has been targeted toward optimizing or finding novel applications in the biomedical field. However, the effects of electrospinning on PVA biocompatibility have not been thoroughly evaluated. In this study, the cytotoxicity of electrospun PVA (nPVA) which was not crosslinked after electrospinning was assessed. PVA polymers of several molecular weights were dissolved in distilled water and electrospun using the same parameters. Electrospun PVA materials with varying molecular weights were then dissolved in tissue culture medium and directly compared against solutions of nonelectrospun PVA polymer in human coronary artery smooth muscle cells and human coronary artery endothelial cells cultures. All nPVA solutions were cytotoxic at a threshold molar concentration that correlated with the molecular weight of the starting PVA polymer. In contrast, none of the nonelectrospun PVA solutions caused any cytotoxicity, regardless of their concentration in the cell culture. Evaluation of the nPVA material by differential scanning calorimetry confirmed that polymer degradation had occurred after electrospinning. To elucidate the identity of the nPVA component that caused cytotoxicity, nPVA materials were dissolved, fractionated using size exclusion columns, and the different fractions were added to HCASMC and human coronary artery endothelial cells cultures. These studies indicated that the cytotoxic component of the different nPVA solutions were present in the low‐molecular‐weight fraction. Additionally, the amount of PVA present in the 3–10 kg/mol fraction was approximately sixfold greater than that in the nonelectrospun samples. In conclusion, electrospinning of PVA resulted in small‐molecular‐weight fractions that were cytotoxic to cells. This result demonstrates that biocompatibility of electrospun biodegradable polymers should not be assumed on the basis of success of their nonelectrospun predecessors. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 1652–1662, 2015.
One‐Pot Synthesis of Some Dynamic 2‐Substituted Benzoxazinones and Their Corresponding Qinazolinones of Anticipated Biological Activity
Authors: El‐Hashash Maher A. , Azab Mohamed E. , Morsy Jehan M.
Published: January 2015

Reactions of 6‐bromo‐2‐isopropyl‐4(3H)‐3,1‐benzoxazin‐4‐one toward mono‐ and di‐dentate nitrogen nucleophiles, e.g. primary aliphatic and aromatic amines, 1,2‐phenylenediamine, hydrazine hydrate, and formamide, have been investigated and afford the corresponding quinazolinones which are expected to have some interesting biological activity. The behavior of 3, 1‐benzoxazin‐4‐one toward active methylene compounds, namely, acetylacetone in basic medium has been studied and gave 3‐acetylquinoline. The last reaction is considered as an illustrative model of heterocyclic transformation reactions.
An analytical model of triple‐material double‐gate metal–oxide–semiconductor field‐effect transistor to suppress short‐channel effects
Authors: Baral Biswajit , Das Aloke Kumar , De Debashis , Sarkar Angsuman
Published: January 2015

This paper presents an analytical subthreshold model for surface potential and threshold voltage of a triple‐material double‐gate (DG) metal–oxide–semiconductor field‐effect transistor. The model is developed by using a rectangular Gaussian box in the channel depletion region with the required boundary conditions at the source and drain end. The model is used to study the effect of triple‐material gate structure on the electrical performance of the device in terms of changes in potential and electric field. The device immunity against short‐channel effects is evaluated by comparing the relative performance parameters such as drain‐induced barrier lowering, threshold voltage roll‐off, and subthreshold swing with its counterparts in the single‐material DG and double‐material DG metal–oxide–semiconductor field‐effect transistors. The developed surface potential model not only provides device physics insight but is also computationally efficient because of its simple compact form that can be utilized to study and characterize the gate‐engineered devices. Furthermore, the effects of quantum confinement are analyzed with the development of a quantum‐mechanical correction term for threshold voltage. The results obtained from the model are in close agreement with the data extracted from numerical Technology Computer Aided Design device simulation. Copyright © 2015 John Wiley & Sons, Ltd.
Proteomic analysis of Streptomyces sp. ssr‐198 grown on paddy straw
Authors: Singh Surender , Tiwari Rameshwar , Renuse Santosh , Pranaw Kumar , Nain Lata
Published: January 2015

The filamentous bacteria Streptomyces spp. produces diverse extracellular enzymes and other secondary metabolites. Proteomic analysis of the secretome of holocellulolytic Streptomyces sp. ssr‐198 was done by tandem mass spectrometry using an Orbitrap Velos hybrid mass spectrometer. A wide range of hydrolytic enzymes, including glycoside hydrolases (17), proteases (17), polysaccharide lyases (3), esterases (2), and hypothetical proteins (14) were detected in the secretome analyzed. Overall, the secretome composition constituted of 12.50% cellulases, 17.50% hemicellulases, 21.25% proteases, 17.50% hypothetical proteins, and 31.25% other proteins. Comprehensive analysis of secretome will be useful in gaining better understanding of the unique role of hydrolytic enzymes in lignocellulose hydrolysis and helps in determining the industrial applications of these potent enzymes.
Role of manganese in protection against oxidative stress under iron starvation in cyanobacterium Anabaena 7120
Authors: Kaushik Manish Singh , Srivastava Meenakshi , Verma Ekta , Mishra Arun Kumar
Published: January 2015

The cyanobacterium Anabaena sp. PCC 7120 was grown in presence and absence of iron to decipher the role of manganese in protection against the oxidative stress under iron starvation and growth, manganese uptake kinetics, antioxidative enzymes, lipid peroxidation, electrolyte leakage, thiol content, total peroxide, proline and NADH content was investigated. Manganese supported the growth of cyanobacterium Anabaena 7120 under iron deprived conditions where maximum uptake rate of manganese was observed with lower Km and higher Vmax values. Antioxidative enzymes were also found to be elevated in iron‐starved conditions. Estimation of lipid peroxidation and electrolyte leakage depicted the role of manganese in stabilizing the integrity of the membrane which was considered as the prime target of oxygen free radicals in oxidative stress. The levels of total peroxide, thiol, proline and NADH content, which are the representative of oxidative stress response in Anabaena 7120, were also showed increasing trends in iron starvation. Hence, the results discerned, clearly suggested the role of manganese in protection against the oxidative stress in cyanobacterium Anabaena 7120 under iron starvation either due to its antioxidative properties or involvement as cofactor in a number of antioxidative enzymes.
Speciation and determination of bioavailable arsenic species in soil samples by one‐step solvent extraction and high‐performance liquid chromatography with inductively coupled plasma mass spectrometry
Authors: Sun Jing , Ma Li , Yang Zhaoguang , Lee Hsiaowan , Wang Lin
Published: January 2015

A new analytical method was developed to determine the bioavailable arsenic species (arsenite, arsenate, monomethylarsonic acid, and dimethylarsonic acid) in soil samples using high‐performance liquid chromatography with inductively coupled plasma mass spectrometry. Bioavailable arsenic was extracted with ammonium phosphate buffer by a simplified one‐step solvent extraction procedure. To estimate the effect of variables on arsenic extraction, a two‐level Plackett–Burman factorial design was conducted to screen the significant factors that were further investigated by a separate univariate approach. The optimum conditions were confirmed by compromising the stability of arsenic species and the extraction efficiency. The concentration of arsenic species was determined in method blank and soil‐certified reference materials both spiked with standard solutions of arsenic species. All the target arsenic species were stable during the whole extraction procedure. Furthermore, the proposed method was applied to release bioavailable arsenic from contaminated soil samples, showing that the major arsenic species in soil samples were inorganic arsenic: arsenite and arsenate, of which the latter was dominant.
An alternative approach for quasi‐static large deformation analysis of saturated porous media using meshfree method
Authors: Khoshghalb Arman , Khalili Nasser
Published: January 2015

An alternative coupled large deformation formulation combined with a meshfree approach is proposed for flow–deformation analysis of saturated porous media. The formulation proposed is based on the Updated Lagrangian (UL) approach, except that the spatial derivatives are defined with respect to the configuration of the medium at the last time step rather than the configuration at the last iteration. In this way, the Cauchy stresses are calculated directly, rendering the second Piola–Kirchhoff stress tensor not necessary for the numerical solution of the equilibrium equations. Moreover, in contrast with the UL approach, the nodal shape function derivatives are calculated once in each time step and stored for use in subsequent iterations, which reduces the computational cost of the algorithm. Stress objectivity is satisfied using the Jaumann stress rate, and the spatial discretisation of the governing equations is achieved using the standard Galerkin method. The equations of equilibrium are satisfied directly, and the nonlinear parts of the system matrix are derived independent of the stresses of the medium resulting in a stable numerical algorithm. Temporal discretisation is effected based on a three‐point approximation technique that avoids spurious ripple effects and has second‐order accuracy. The radial point interpolation method is used to construct the shape functions. The application of the formulation and the significance of large deformation effects on the numerical results are demonstrated through several numerical examples. Copyright © 2015 John Wiley & Sons, Ltd.
In vivo quantitative magnetization transfer imaging correlates with histology during de‐ and remyelination in cuprizone‐treated mice
Authors: Turati Laura , Moscatelli Marco , Mastropietro Alfonso , Dowell Nicholas G. , Zucca Ileana , Erbetta Alessandra , Cordiglieri Chiara , Brenna Greta , Bianchi Beatrice , Mantegazza Renato , Cercignani Mara , Baggi Fulvio , Minati Ludovico
Published: January 2015

The pool size ratio measured by quantitative magnetization transfer MRI is hypothesized to closely reflect myelin density, but their relationship has so far been confirmed mostly in ex vivo conditions. We investigate the correspondence between this parameter measured in vivo at 7.0 T, with Black Gold II staining for myelin fibres, and with myelin basic protein and beta‐tubulin immunofluorescence in a hybrid longitudinal study of C57BL/6 and SJL/J mice treated with cuprizone, a neurotoxicant causing relatively selective myelin loss followed by spontaneous remyelination upon treatment suspension. Our results confirm that pool size ratio measurements correlate with myelin content, with the correlation coefficient depending on strain and staining method, and demonstrate the in vivo applicability of this MRI technique to experimental mouse models of multiple sclerosis. Copyright © 2015 John Wiley & Sons, Ltd.