bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of a hierarchy of models reveals importance of substrate limitation for predicting carbon dioxide and methane exchange in restored wetlands
Authors: Oikawa P. Y. , Jenerette G. D. , Knox S. H. , Sturtevant C. , Verfaillie J. , Dronova I. , Poindexter C. M. , Eichelmann E. , Baldocchi D. D.
Published: December 2016

Wetlands and flooded peatlands can sequester large amounts of carbon (C) and have high greenhouse gas mitigation potential. There is growing interest in financing wetland restoration using C markets; however, this requires careful accounting of both CO2and CH4exchange at the ecosystem scale. Here we present a new model, the PEPRMT model (Peatland Ecosystem Photosynthesis Respiration and Methane Transport), which consists of a hierarchy of biogeochemical models designed to estimate CO2and CH4exchange in restored managed wetlands. Empirical models using temperature and/or photosynthesis to predict respiration and CH4production were contrasted with a more process‐based model that simulated substrate‐limited respiration and CH4production using multiple carbon pools. Models were parameterized by using a model‐data fusion approach with multiple years of eddy covariance data collected in a recently restored wetland and a mature restored wetland. A third recently restored wetland site was used for model validation. During model validation, the process‐based model explained 70% of the variance in net ecosystem exchange of CO2(NEE) and 50% of the variance in CH4exchange. Not accounting for high respiration following restoration led to empirical models overestimating annual NEE by 33–51%. By employing a model‐data fusion approach we provide rigorous estimates of uncertainty in model predictions, accounting for uncertainty in data, model parameters, and model structure. The PEPRMT model is a valuable tool for understanding carbon cycling in restored wetlands and for application in carbon market‐funded wetland restoration, thereby advancing opportunity to counteract the vast degradation of wetlands and flooded peatlands.
Winter respiratory C losses provide explanatory power for net ecosystem productivity
Authors: Haeni M. , Zweifel R. , Eugster W. , Gessler A. , Zielis S. , Bernhofer C. , Carrara A. , Grünwald T. , Havránková K. , Heinesch B. , Herbst M. , Ibrom A. , Knohl A. , Lagergren F. , Law B. E. , Marek M. , Matteucci G. , McCaughey J. H. , Minerbi S. , Montagnani L. , Moors E. , Olejnik J. , Pavelka M. , Pilegaard K. , Pita G. , Rodrigues A. , Sanz Sánchez M. J. , Schelhaas M.‐J. , Urbaniak M. , Valentini R. , Varlagin A. , Vesala T. , Vincke C. , Wu J. , Buchmann N.
Published: December 2016

Accurate predictions of net ecosystem productivity (NEPc) of forest ecosystems are essential for climate change decisions and requirements in the context of national forest growth and greenhouse gas inventories. However, drivers and underlying mechanisms determining NEPc (e.g., climate and nutrients) are not entirely understood yet, particularly when considering the influence of past periods. Here we explored the explanatory power of the compensation day (cDOY)—defined as the day of year when winter net carbon losses are compensated by spring assimilation—for NEPc in 26 forests in Europe, North America, and Australia, using different NEPc integration methods. We found cDOY to be a particularly powerful predictor for NEPc of temperate evergreen needleleaf forests (R2 = 0.58) and deciduous broadleaf forests (R2 = 0.68). In general, the latest cDOY correlated with the lowest NEPc. The explanatory power of cDOY depended on the integration method for NEPc, forest type, and whether the site had a distinct winter net respiratory carbon loss or not. The integration methods starting in autumn led to better predictions of NEPc from cDOY then the classical calendar method starting 1 January. Limited explanatory power of cDOY for NEPc was found for warmer sites with no distinct winter respiratory loss period. Our findings highlight the importance of the influence of winter processes and the delayed responses of previous seasons' climatic conditions on current year's NEPc. Such carry‐over effects may contain information from climatic conditions, carbon storage levels, and hydraulic traits of several years back in time.
Improving operating policies of large‐scale surface‐groundwater systems through stochastic programming
Authors: Macian‐Sorribes H. , Tilmant A. , Pulido‐Velazquez M.
Published: December 2016

The management of large‐scale water resource systems with surface and groundwater resources requires considering stream‐aquifer interactions. Optimization models applied to large‐scale systems have either employed deterministic optimization (with perfect foreknowledge of future inflows, which hinders their applicability to real‐life operations) or stochastic programming (in which stream‐aquifer interaction is often neglected due to the computational burden associated with these methods). In this paper, stream‐aquifer interaction is integrated in a stochastic programming framework by combining the Stochastic Dual Dynamic Programming (SDDP) optimization algorithm with the Embedded Multireservoir Model (EMM). The resulting extension of the SDDP algorithm, named Combined Surface‐Groundwater SDDP (CSG‐SDDP), is able to properly represent the stream‐aquifer interaction within stochastic optimization models of large‐scale surface‐groundwater resource systems. The algorithm is applied to build a hydroeconomic model for the Jucar River Basin (Spain), in which stream‐aquifer interactions are essential to the characterization of water resources. Besides the uncertainties regarding the economic characterization of the demand functions, the results show that the economic efficiency of the operating policies under the current system can be improved by better management of groundwater and surface resources.
Hierarchical Architectures to Enhance Structural and Functional Properties of Brittle Materials
Authors: Bermejo Raúl , Daniel Rostislav , Schuecker Clara , Paris Oskar , Danzer Robert , Mitterer Christian
Published: December 2016

This paper reviews current activities at the Montanuniversität Leoben on the hierarchical design of flaw‐tolerant brittle materials in the fields of layered ceramics, hard coatings, fibre reinforced laminates, and biomimetic functional systems. Different examples of reinforcement mechanisms are presented acting at different length scales. Novel strategies are analyzed that make use of tailored residual stresses, textured microstructures, compositional heterogeneity and spatial variations in properties, fiber arrangement and laminate stacking, or functionalization of hierarchical materials from brittle constituents. Potential implications of hierarchical structures combining different materials science approaches for future engineering designs are discussed.
AFM Identification of Beetle Exocuticle: Bouligand Structure and Nanofiber Anisotropic Elastic Properties
Authors: Yang Ruiguo , Zaheri Alireza , Gao Wei , Hayashi Cheryl , Espinosa Horacio D.
Published: December 2016

One of the common architectures in natural materials is the helicoidal (Bouligand) structure, where fiber layers twist around a helical screw. Despite the many studies that have shown the existence of Bouligand structures, methods for nanoscale structural characterization and identification of fiber mechanical properties remain to be developed. In this study, we used the exocuticle of Cotinis mutabilis (a beetle in the Cetoniinae) as a model material to develop a new experimental‐theoretical methodology that combines atomic force microscopy‐based nanoindentation and anisotropic contact mechanics analysis. Using such methodology, we studied both the helicoidal structure and the mechanical properties of its constituent fibers. The twist angle between the layers was found to be in the range of 12°–18° with a pitch size of 220 nm for the helicoidal pattern. In addition, the constituent fiber diameter was measured to be approximately 20 nm, which is consistent with the fiber diameters found in helicoids of other arthropod species. The longitudinal, transverse, and shear modulus of the nanofiber were determined to be 710 MPa, 70 MPa, and 90 MPa, respectively. The established experimental‐theoretical methodology promises to be a useful tool for nanoscale characterization of helicoidal and other structures found in biological materials.
Active Regulation of On‐Demand Drug Delivery by Magnetically Triggerable Microspouters
Authors: Shademani Ali , Zhang Hongbin , Jackson John K. , Chiao Mu
Published: December 2016

Triggerable devices capable of on‐demand, controlled release of therapeutics are attractive options for the treatment of local diseases because of their potential to enhance therapeutic effectiveness with reduced systemic toxicity. Here, the design and fabrication of a miniaturized device, termed a microspouter, is described. This device is shown to provide active and precise control of localized delivery of drugs on demand. The microspouter is composed of a magnetic sponge to provide the force for drug release through magnetic field‐induced reversible deformation, a reservoir for the sponge installation and drug loading, and a soft membrane for sealing the device. Following application of a magnetic field to the microspouter, the shrinking of the sponge may trigger a spouting of drug through a membrane's microaperture. The efficiency of the device in controlling the dose and time course of drug release under different external magnetic fields has been demonstrated using methylene blue and docetaxel as model drugs. Additionally, the microspouter is found to have low background drug leakage that allows for tunable drug release in an ex vivo implantation experiment. All the results confirm the microspouter as a potential device for safe, long‐time, and controlled drug release in local disease treatment.
High‐Performance Organic Heterojunction Phototransistors Based on Highly Ordered Copper Phthalocyanine/para‐Sexiphenyl Thin Films
Authors: Qian Chuan , Sun Jia , Kong Ling‐An , Gou Guangyang , Zhu Menglong , Yuan Yongbo , Huang Han , Gao Yongli , Yang Junliang
Published: December 2016

High‐performance organic heterojunction phototransistors are fabricated using highly ordered copper phthalocyanine (CuPc) and para‐sexiphenyl (p‐6P) thin films. The p‐6P thin film plays an important role on the performance of CuPc/p‐6P heterojunction phototransistors. It acts as a molecular template layer to induce the growth of highly ordered CuPc thin film, which dramatically improves the charge transport and decreases the grain boundaries. On the other hand, the p‐6P thin film can form an effective heterojunction with CuPc thin film, which is greatly helpful to enhance the light absorption and photogenerated carriers. Under 365 nm ultraviolet light irradiation, the ratio of photocurrent and dark current and photoresponsivity of CuPc/p‐6P heterojunction phototransistors reaches to about 2.2 × 104 and 4.3 × 102 A W−1, respectively, which are much larger than that of CuPc phototransistors of about 2.7 × 102 and 7.3 A W−1, respectively. A detailed study carried out with current sensing atomic force microscopy proves that the photocurrent is predominately produced inside the highly ordered CuPc/p‐6P heterojunction grains, while the photocurrent produced at the boundaries between grains can be neglected. The research provides a good method for fabricating high‐performance organic phototransistors using a combination of molecular template growth and organic heterojunction.
Impact of Crystal Surface on Photoexcited States in Organic–Inorganic Perovskites
Authors: Birkhold Susanne T. , Zimmermann Eugen , Kollek Tom , Wurmbrand Daniel , Polarz Sebastian , Schmidt‐Mende Lukas
Published: December 2016

Despite their outstanding photovoltaic performance, organic–inorganic perovskite solar cells still face severe stability issues and limitations in their device dimension. Further development of perovskite solar cells therefore requires a deeper understanding of loss mechanisms, in particular, concerning the origin and impact of trap states. Here, different surface properties of submicrometer sized CH3NH3PbI3 particles are studied as a model system by photoluminescence spectroscopy to investigate the impact of the perovskite crystal surface on photoexcited states. Comparison of single crystals with either isolating or electron‐rich surface passivation indicates the presence of positively charged surface trap states that can be passivated in case of the latter. These surface trap states cause enhanced nonradiative recombination at room temperature, which is a loss mechanism for solar cell performance. In the orthorhombic phase, the origin of multiple emission peaks is identified as the recombination of free and bound excitons, whose population ratio critically depends on trap state properties. The dynamics of exciton trapping at 50 K are observed on a time‐scale of tens of picoseconds by a simultaneous population decrease and increase of free and bound excitons, respectively. These results emphasize the potential of surface passivation to further improve the performance of perovskite solar cells.
Fuel‐Free Synthetic Micro‐/Nanomachines
Authors: Xu Tailin , Gao Wei , Xu Li‐Ping , Zhang Xueji , Wang Shutao
Published: December 2016

Inspired by the swimming of natural microorganisms, synthetic micro‐/nanomachines, which convert energy into movement, are able to mimic the function of these amazing natural systems and help humanity by completing environmental and biological tasks. While offering autonomous propulsion, conventional micro‐/nanomachines usually rely on the decomposition of external chemical fuels (e.g., H2O2), which greatly hinders their applications in biologically relevant media. Recent developments have resulted in various micro‐/nanomotors that can be powered by biocompatible fuels. Fuel‐free synthetic micro‐/nanomotors, which can move without external chemical fuels, represent another attractive solution for practical applications owing to their biocompatibility and sustainability. Here, recent developments on fuel‐free micro‐/nanomotors (powered by various external stimuli such as light, magnetic, electric, or ultrasonic fields) are summarized, ranging from fabrication to propulsion mechanisms. The applications of these fuel‐free micro‐/nanomotors are also discussed, including nanopatterning, targeted drug/gene delivery, cell manipulation, and precision nanosurgery. With continuous innovation, future autonomous, intelligent and multifunctional fuel‐free micro‐/nanomachines are expected to have a profound impact upon diverse biomedical applications, providing unlimited opportunities beyond one's imagination.
Nanoarchitectured Design of Porous Materials and Nanocomposites from Metal‐Organic Frameworks
Authors: Kaneti Yusuf Valentino , Tang Jing , Salunkhe Rahul R. , Jiang Xuchuan , Yu Aibing , Wu Kevin C.‐W. , Yamauchi Yusuke
Published: December 2016

The emergence of metal‐organic frameworks (MOFs) as a new class of crystalline porous materials is attracting considerable attention in many fields such as catalysis, energy storage and conversion, sensors, and environmental remediation due to their controllable composition, structure and pore size. MOFs are versatile precursors for the preparation of various forms of nanomaterials as well as new multifunctional nanocomposites/hybrids, which exhibit superior functional properties compared to the individual components assembling the composites. This review provides an overview of recent developments achieved in the fabrication of porous MOF‐derived nanostructures including carbons, metal oxides, metal chalcogenides (metal sulfides and selenides), metal carbides, metal phosphides and their composites. Finally, the challenges and future trends and prospects associated with the development of MOF‐derived nanomaterials are also examined.
Solution Processable Metal Oxide Thin Film Deposition and Material Growth for Electronic and Photonic Devices
Authors: Glynn Colm , O'Dwyer Colm
Published: December 2016

A comprehensive review of recent advances in solution processing and growth of metal‐oxide thin films for electronic and photonic devices is presented, with specific focus on precise solution‐based technological coatings for electronics and optics, and new concepts for oxide material growth for electrochemical, catalytic, energy storage and conversion systems, information technology, semiconductor device processing and related devices. Throughout, the nature of the soluble precursors solutions and their relationship to film formation process by various solution coating techniques are collated and compared, highlighting advantages in precursor design for creating complex oxides for devices. Because of the versatility of solution‐processable oxides and functional material coating, it is important to capture the advances made in oxide deposition for plastic electronics, see‐through and wearable devices, and high‐fidelity thin film transistors on curved or flexible displays. Solution processing, even for oxides, allows control over composition, thickness, optical constants, porosity, doping, tunable optical absorbance/transmission, band structure engineering, 3D‐substrate coating, complex composite oxide formation and multi‐layered oxide systems that are more difficult to achieve using chemical vapor deposition (CVD) or atomic layer deposition (ALD) processes. We also discuss limitations of solution processing for some technologies and comment on the future of solution‐based processing of metal‐oxide materials for electronics, photonics and other technologies.
Ultrafast All‐Optical Switching
Authors: Chai Zhen , Hu Xiaoyong , Wang Feifan , Niu Xinxiang , Xie Jingya , Gong Qihuang
Published: December 2016

Ultrafast all‐optical switching, possessing the unique function of light controlling light, is an essential component of on‐chip ultrafast optical connection networks as well as integrated logic computing chips. Ultrafast all‐optical switching has attracted enormous research interests, the latest great developments of which have also yield progress in nanophotonics, integrated optics, nonlinear optics, material science, and optical communications, and so on. This review summarizes the fundamental realization principles, novel configurations, fancy materials, improved performance indexes, and ameliorated trigger method (transitioning from a traditional impractical free‐space‐vertical trigger to a more practical on‐chip trigger) of ultrafast all‐optical switching. Not only a systematic discussion of the current state‐of‐the art is provided, but also a brief outlook on the remaining challenges in the pursuit of the application of a practical on‐chip ultrafast all‐optical switching is also afforded.
Graphene Based Terahertz Light Modulator in Total Internal Reflection Geometry
Authors: Liu Xudong , Chen Zefeng , Parrott Edward P. J. , Ung Benjamin S.‐Y. , Xu Jianbin , Pickwell‐MacPherson Emma
Published: December 2016

Modulation of visible light has been easily achieved for decades, but modulation of terahertz (THz) light still remains a challenge. To address this issue, the Fresnel equations have been developed to describe a conductive interface in a total internal reflection geometry and reveal a new approach for modulation. To demonstrate this new mechanism, a broadband device achieving a modulation depth greater than 90% between 0.15 and 0.4 THz, and reaching a maximum of 99.3% at 0.24 THz has been designed. The modulation is achieved by applying a gate voltage between −0.1 and 2 V to a graphene layer in a total internal reflection geometry. Compared to conventional designs, the high modulation is realized without assistance from metamaterial structures, resonant cavities, or multistacked graphene layers. Thus, the design is efficient and easy‐to‐fabricate and can be easily retrofitted to most existing THz systems. This work opens up a new avenue of research as the device has verified the theory and demonstrates how it can be used to make practical devices, bringing a promising new paradigm for THz modulation, thin‐film sensing, and noninvasive material characterization.
Plasmonics in Organic and Perovskite Solar Cells: Optical and Electrical Effects
Authors: Chan Kah , Wright Matthew , Elumalai Naveen , Uddin Ashraf , Pillai Supriya
Published: December 2016

Solution processed thin‐film solar technologies, such as organic photovoltaics, and more recently, perovskite solar cells, may provide low‐cost electricity generation. These technologies suffer from insufficient light absorption due to thin absorber layers. Plasmonic nanostructures have been incorporated in both technologies, initially with the aim of increasing light absorption, but reports have also shown significant enhancement in electrical characteristics in devices. Enhancement mechanisms that are facilitated by plasmonic nanostructures such as improved exciton dissociation and charge carrier transport, can occur concurrently with improved light absorption. This work surveys the myriad enhancement mechanisms and, importantly, discusses the extent of current understanding, as well as insights gained in plasmonics applications thus far. Given the substantial opportunities, the continuous focus on characterization and interpretation of enhancement mechanisms is imperative to unlock the full potential of plasmonic organic and perovskite solar cells. In particular, electrical or electronic effects from plasmonic nanostructure integration deserves further attention as a promising complement to improvements in device performance from optical effects.
Photocatalytic Trifluoromethylthiolation of Aromatic Alkenes Associated with Hydroxylation and Alkoxylation
Authors: Li Yanjie , Koike Takashi , Akita Munetaka
Published: December 2016

A photoredox‐catalyzed trifluoromethylthiolation process of aromatic alkenes has been developed. A strongly reducing photocatalyst, fac‐[Ir(4‐MeO‐ppy)3] (4‐MeO‐ppy=2‐pyridyl‐5‐methoxyphenyl), and an electrophilic trifluoromethylthiolating reagent, 1‐(trifluoromethylthio)pyrrolidine‐2,5‐dione (1 a), play key roles in the efficient generation of a trifluoromethansulfenyl radical (.SCF3). The well‐designed photoredox system induces a single‐step, regioselective installation of a CF3S and a hydroxy or an alkoxy group onto vicinal carbon atoms through redox‐neutral processes. The present oxytrifluoromethylthiolation features mild reaction conditions without extra additives for the activation of the CF3S reagent, making the present protocol applicable to a wide variety of functionalized aromatic alkenes.
Efficacy of direct hemoperfusion with a polymyxin B‐immobilized fiber column in miliary tuberculosis
Authors: Kawano Yasumasa , Nagashima Ryotaro , Morimoto Shinichi , Izutani Yoshito , Yamasaki Reiko , Nishida Takeshi , Iwaasa Mitsutoshi , Ishikura Hiroyasu
Published: December 2016

Case

A 75‐year‐old woman presented with a 10‐day history of intermittent fever, general fatigue, and progressive dyspnea. Although she had a low PaO2/FIO2 ratio, the cause of acute respiratory distress syndrome was not clear until day 9 in hospital.

Outcome

We treated the patient with direct hemoperfusion with a polymyxin B‐immobilized fiber column incidentally; the PaO2/FIO2 ratio improved following this therapy. Acid‐fast bacilli, which were not seen in the sputum on admission, were detected in cultures from sputum, urine, bone marrow, liver biopsy, and blood samples, with a real‐time polymerase chain reaction assay confirming tuberculosis. She was immediately transferred to a specialized tuberculosis hospital, and after a 3‐month treatment, was discharged.

Conclusion

Treatment with polymyxin B‐immobilized fiber column may provide good results for pulmonary oxygenation in acute respiratory distress syndrome caused by tuberculosis.
Anti‐LGI1 encephalitis is strongly associated with HLA‐DR7 and HLA‐DRB4
Authors: van Sonderen Agnes , Roelen Dave L. , Stoop Johannes A. , Verdijk Robert M. , Haasnoot Geert W. , Thijs Roland D. , Wirtz Paul W. , Schreurs Marco W. J. , Claas Frans H. J. , Sillevis Smitt Peter A. E. , Titulaer Maarten J.
Published: December 2016

Leucine‐rich glioma‐inactivated1 (LGI1) encephalitis is an antibody‐associated inflammation of the limbic area. An autoimmune etiology is suspected but not yet proven. We performed human leukocyte antigen (HLA) analysis in 25 nontumor anti‐LGI1 patients and discovered a remarkably strong HLA association. HLA‐DR7 was present in 88% compared to 19.6% in healthy controls (p = 4.1 × 10−11). HLA‐DRB4 was present in all patients and in 46.5% controls (p = 1.19 × 10−7). These findings support the autoimmune hypothesis. An exploratory analysis was performed in a small group of 4 tumor‐LGI1 patients. The strong HLA association seems not applicable in these patients. Therefore, the absence of HLA‐DR7 or HLA‐DRB4 could raise tumor suspicion in anti‐LGI1 patients. Ann Neurol 2017;81:193–198
Katalytische enantioselektive und diastereoselektive allylische Alkylierung mit Fluorenolaten: Synthese von C3‐fluorierten und quartären Oxindolen
Authors: Balaraman Kaluvu , Wolf Christian
Published: December 2016

Synthetisch vielseitige 3,3‐disubstituierte Fluoroxindole mit benachbarten Chiralitätszentren wurden in hohen Ausbeuten und mit exzellenten Enantio‐, Diastereo‐ und Regioselektivitäten durch katalytische asymmetrische Alkylierung von Fluorenolaten mit Allylacetaten erhalten. Die Reaktion verläuft unter milden Bedingungen und kann in größeren Ansätzen ohne Beeinträchtigung der asymmetrischen Induktion durchgeführt werden. Der präparative Nutzen der Produkte wird durch den Einbau von zusätzlichen Funktionsgruppen und die Bildung von C3‐fluorierten Oxindolen mit vier angrenzenden Chiralitätszentren belegt. Eine neue Methode zur C‐F‐Bindungsfunktionalisierung, die neuartige Möglichkeiten für die stereoselektive Erzeugung eines chiralen quartären Kohlenstoffzentrums im Alkaloidgerüst ermöglicht, wird aufgezeigt.
Aufklärung des Dexter‐Energietransfers in DNA an der Thymin‐Thymin‐Dimerbildung mithilfe von Photosensibilisatoren als artifizielle Nucleoside
Authors: Antusch Linda , Gaß Nadine , Wagenknecht Hans‐Achim
Published: December 2016

Die C‐Nucleoside von 4‐Methylbenzophenon, 4‐Methoxybenzophenon und 2′‐Methoxyacetophenon wurden als interne Photosensibilisatoren synthetisch in DNA‐Doppelstränge eingebaut. Dieser strukturell neuartige Ansatz erlaubt es, die Distanzabhängigkeit der Thymidin‐Dimerbildung zu untersuchen, weil der Ort der photoinduzierten Injektion der Triplettenergie eindeutig definiert ist. Den Gegensträngen dieser modifizierten Oligonucleotide fehlte die Phosphodiesterbindung zwischen zwei benachbarten Thymidinen, die miteinander reagieren sollten. Deren Dimerisierung konnte durch Gelelektrophorese nachgewiesen werden, weil die kovalente Verbindung durch die Cyclobutanbildung zwischen den zwei Thymidinen die Mobilität verändert. Eine schwache exponentielle Distanzabhängigkeit der Thymidin‐Dimerbildung wurde über bis zu 10 A‐T‐Basenpaare beobachtet, was im Einklang mit einem Dexter‐Triplett‐Triplett‐Energietransfermechanismus steht. Gleichzeitig wurde eine deutliche Menge an photoinduzierten DNA‐Crosslinks beobachtet.
Dipolar Relaxation Dynamics at the Active Site of an ATPase Regulated by Membrane Lateral Pressure
Authors: Fischermeier Elisabeth , Pospíšil Petr , Sayed Ahmed , Hof Martin , Solioz Marc , Fahmy Karim
Published: December 2016

The active transport of ions across biological membranes requires their hydration shell to interact with the interior of membrane proteins. However, the influence of the external lipid phase on internal dielectric dynamics is hard to access by experiment. Using the octahelical transmembrane architecture of the copper‐transporting P1B‐type ATPase from Legionella pneumophila as a model structure, we have established the site‐specific labeling of internal cysteines with a polarity‐sensitive fluorophore. This enabled dipolar relaxation studies in a solubilized form of the protein and in its lipid‐embedded state in nanodiscs. Time‐dependent fluorescence shifts revealed the site‐specific hydration and dipole mobility around the conserved ion‐binding motif. The spatial distribution of both features is shaped significantly and independently of each other by membrane lateral pressure.
Catalytic Enantioselective and Diastereoselective Allylic Alkylation with Fluoroenolates: Efficient Access to C3‐Fluorinated and All‐Carbon Quaternary Oxindoles
Authors: Balaraman Kaluvu , Wolf Christian
Published: December 2016

Synthetically versatile 3,3‐disubstituted fluorooxindoles exhibiting vicinal chirality centers were obtained in high yields and with excellent enantio‐, diastereo‐, and regioselectivity through catalytic asymmetric fluoroenolate alkylation with allylic acetates. The reaction proceeds under mild conditions and can be scaled up without compromising the asymmetric induction. The unique synthetic usefulness of the products is highlighted by the incorporation of additional functionalities and the formation of 3‐fluorinated oxindoles exhibiting an array of four adjacent centers of chirality. A new C−F bond functionalization path that provides unprecedented possibilities for the stereoselective generation of a chiral quaternary carbon center in the alkaloid scaffold is introduced.
Consideration of different heating lengths of needles with induction heating and resistance system: A novel design of needle module for thermal ablation
Authors: Bui Huy‐Tien , Hwang Sheng‐Jye , Lee Huei‐Huang , Huang Durn‐Yuan
Published: December 2016

Thermal ablation using alternating electromagnetic fields is a promising method to treat tissues including tumors. With this approach, an electromagnetic field is generated around an induction coil, which is supplied with high frequency current from a power source. Any electrically conducting object, which is placed in the electromagnetic field, is then heated due to eddy currents. Basic principles underlying this novel thermotherapy needle system are internal induction and resistance heating. This presents a new design of a standard gauge 18 percutaneous trans‐hepatic cholangiography needle module combined with a compact power source. Three needle modules containing coils of different lengths were used to locally heat up different volumes of tissues in in vitro experiments on pig livers. Temperature on the inside surface of the needle was controlled and monitored through a K‐type thermocouple. By using this needle module system, no two‐section or ferromagnetic nanoparticle‐coated needles were required; the system worked well with the SUS‐304 stainless‐steel needle. Successful results were demonstrated in the in vitro experiments on pig livers with different heating lengths of 10, 20, and 30 mm needles. With low power sources, needles could be heated up to a high temperature. The novel design of the needle module incorporated with a high frequency power source was thus shown to be a promising technology for tissue ablation. Bioelectromagnetics.38:220–226, 2017. © 2016 Wiley Periodicals, Inc.
RF‐EMF exposure at 1800 MHz did not elicit DNA damage or abnormal cellular behaviors in different neurogenic cells
Authors: Su Liling , Wei Xiaoxia , Xu Zhengping , Chen Guangdi
Published: December 2016

Despite many years of studies, the debate on genotoxic effects of radiofrequency electromagnetic fields (RF‐EMF) continues. To systematically evaluate genotoxicity of RF‐EMF, this study examined effects of RF‐EMF on DNA damage and cellular behavior in different neurogenic cells. Neurogenic A172, U251, and SH‐SY5Y cells were intermittently (5 min on/10 min off) exposed to 1800 MHz RF‐EMF at an average specific absorption rate (SAR) of 4.0 W/kg for 1, 6, or 24 h. DNA damage was evaluated by quantification of γH2AX foci, an early marker of DNA double‐strand breaks. Cell cycle progression, cell proliferation, and cell viability were examined by flow cytometry, hemocytometer, and cell counting kit‐8 assay, respectively. Results showed that exposure to RF‐EMF at an SAR of 4.0 W/kg neither significantly induced γH2AX foci formation in A172, U251, or SH‐SY5Y cells, nor resulted in abnormal cell cycle progression, cell proliferation, or cell viability. Furthermore, prolonged incubation of these cells for up to 48 h after exposure did not significantly affect cellular behavior. Our data suggest that 1800 MHz RF‐EMF exposure at 4.0 W/kg is unlikely to elicit DNA damage or abnormal cellular behaviors in neurogenic cells. Bioelectromagnetics. 38:175–185, 2017. © 2016 Wiley Periodicals, Inc.
The re‐emerging arboviral threat: Hidden enemies
Authors: Dutra Heverton Leandro Carneiro , Caragata Eric Pearce , Moreira Luciano Andrade
Published: December 2016

Mayaro, Oropouche, and O'Nyong‐Nyong share many traits with more prominent arboviruses, like dengue and yellow fever, chikungunya, and Zika. These include severe clinical symptoms, multiple animal hosts, and widespread vector species living in close proximity to human habitats, all of which constitute significant risk factors for more frequent outbreaks in the future, greatly increasing the potential of these hidden enemies to follow Zika and become the next wave of global arboviral threats. Critically, the current dearth of knowledge on these arboviruses might impede the success of future control efforts, including the potential application ofWolbachia pipientis. This bacterium inherently possesses broad anti‐pathogen properties and a means of genetic drive that allows it to eliminate or replace target vector populations. We conclude that control of obscure arboviruses withWolbachiamight be possible, but successful implementation will be critically dependent on the ability to transinfect key vector species.
Estimating latent trends in multivariate longitudinal data via Parafac2 with functional and structural constraints
Authors: Helwig Nathaniel E.
Published: December 2016

Longitudinal data are inherently multimode in the sense that such data are often collected across multiple modes of variation, for example, time × variables × subjects. In many longitudinal studies, multiple variables are collected to measure some latent construct(s) of interest. In such cases, the goal is to understand temporal trends in the latent variables, as well as individual differences in the trends. Multimode component analysis models provide a powerful framework for discovering latent trends in longitudinal data. However, classic implementations of multimode models do not take into consideration functional information (i.e., the temporal sequence of the collected data) or structural information (i.e., which variables load onto which latent factors) about the study design. In this paper, we reveal how functional and structural constraints can be imposed in multimode models (Parafac and Parafac2) in order to elucidate trends in longitudinal data. As a motivating example, we consider a longitudinal study on per capita alcohol consumption trends conducted from 1970 to 2013 by the U.S. National Institute on Alcohol Abuse and Alcoholism. We demonstrate how functional and structural information about the study design can be incorporated into the Parafac and Parafac2 alternating least squares algorithms to understand temporal and regional trends in three latent constructs: beer consumption, spirits consumption, and wine consumption. Our results reveal that Americans consume more than the recommended amount of alcohol, and total alcohol consumption trends show no signs of decreasing in the last decade.
Conformational properties and aggregation of homo‐oligomeric β3(R)‐valine peptides in organic solvents
Authors: Vasantha Basavalingappa , Yamanappa Hunashal , Raghothama Srinivasarao , Balaram Padmanabhan
Published: December 2016

The conformational characteristics of protected homo‐oligomeric Boc‐[β3(R)Val]n‐OMe, n = 1, 2, 3, 4, 6, 9, and 12 have been investigated in organic solvents using nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) absorption spectroscopy and circular dichroism (CD) methods. The detailed 1H NMR analysis of Boc‐[β3(R)Val]12‐OMe reveals that the peptide aggregates extensively in CDCl3, but is disaggregated in 20%, (v/v) dimethyl sulfoxide (DMSO) in CDCl3 and in CD3OH. Limited assignment of the N‐terminus NH groups, together with solvent dependence of NH chemical shifts and temperature coefficients provides evidence for 14‐helix conformation in the 12‐residue peptide. FTIR analysis in CHCl3 establishes that the onset of folding and aggregation, as evidenced by NH stretching bands at 3375 cm−1 (intramolecular) and 3285 cm−1 (intermolecular), begins at the level of the tetrapeptide. The observed CD bands, 214 nm (negative) and 198 nm (positive), support 14‐helix formation in the 9 and 12 residue sequences. The folding and aggregation tendencies of homo‐oligomeric α‐, β‐, and γ‐ residues is compared in the model peptides Boc‐[ωVal]n‐NHMe, ω = α, β, and γ and n = 1, 2, and 3. Analysis of the FTIR spectra in CHCl3, establish that the tendency to aggregate at the di and tripeptide level follows the order β > α∼γ, while the tendency to fold follows the order γ > β > α.
Cr‐MIL‐101‐Encapsulated Keggin Phosphomolybdic Acid as a Catalyst for the One‐Pot Synthesis of 2,5‐Diformylfuran from Fructose
Authors: Zhao Jun , Anjali Jayakumar , Yan Yibo , Lee Jong‐Min
Published: December 2016

The conversion of fructose into 2,5‐diformylfuran (DFF) is a tandem reaction that consists of the dehydration of fructose to 5‐hydroxymethylfurfural (HMF) catalyzed by an acid catalyst and subsequent oxidation of HMF to DFF by a redox catalyst. Phosphomolybdic acid encapsulated in MIL‐101 (PMA–MIL‐101), with high Brønsted acidity and moderate redox potential, was evaluated as a promising catalyst for the one‐pot synthesis of DFF directly from fructose. The results demonstrated that PMA–MIL‐101 was an efficient and recyclable bifunctional catalyst for the production of DFF from fructose in DMSO; it showed high activity and selectivity towards the direct transformation of fructose into DFF, and it could be reused. A satisfactory DFF yield of 75.1 % was obtained over 2 PMA–MIL‐101 in a one‐pot, one‐step reaction under optimal reaction conditions.
Characterization of New Wire Gauze High‐Capacity Structured Packing with Varied Inclination Angle
Authors: Amini Younes , Karimi-Sabet Javad , Esfahany Mohsen Nasr
Published: December 2016

A new high‐capacity structured packing (PACK‐1300) was investigated for the separation of mixtures with low separation factor. The effect of the inclination angle was studied. In order to enhance the pressure drop and the separation efficiency of PACK‐1300, the surface area and porosity were increased. In addition, comprehensive parametric studies were performed to evaluate the dry/wet pressure drop and mass‐transfer efficiency under various operating conditions. Increasing the inclination angle enhances the capacity and decreases the efficiency of the packings. PACK‐1300W reduced the dry and wet pressure drop significantly more than PACK‐1300Z. Finally, the separation efficiency results show that the height equivalent to a theoretical plate decreased with decreasing inclination angle.
Alkene Metalates as Hydrogenation Catalysts
Authors: Büschelberger Philipp , Gärtner Dominik , Reyes‐Rodriguez Efrain , Kreyenschmidt Friedrich , Koszinowski Konrad , Jacobi von Wangelin Axel , Wolf Robert
Published: December 2016

First‐row transition‐metal complexes hold great potential as catalysts for hydrogenations and related reductive reactions. Homo‐ and heteroleptic arene/alkene metalates(1−) (M=Co, Fe) are a structurally distinct catalyst class with good activities in hydrogenations of alkenes and alkynes. The first syntheses of the heteroleptic cobaltates [K([18]crown‐6)][Co(η4‐cod)(η2‐styrene)2] (5) and [K([18]crown‐6)][Co(η4‐dct)(η4‐cod)] (6), and the homoleptic complex [K(thf)2][Co(η4‐dct)2] (7; dct=dibenzo[a,e]cyclooctatetraene, cod=1,5‐cyclooctadiene), are reported. For comparison, two cyclopentadienylferrates(1−) were synthesized according to literature procedures. The isolated and fully characterized monoanionic complexes were competent precatalysts in alkene hydrogenations under mild conditions (2 bar H2, r.t., THF). Mechanistic studies by NMR spectroscopy, ESI mass spectrometry, and poisoning experiments documented the operation of a homogeneous mechanism, which was initiated by facile redox‐neutral π‐ligand exchange with the substrates followed by H2 activation. The substrate scope of the investigated precatalysts was also extended to polar substrates (ketones and imines).
Voltage combined with pace mapping is simple and effective for ablation of noninducible premature ventricular contractions originating from the right ventricular outflow tract
Authors: Wang Zefeng , Zhang Heping , Peng Hui , Shen Xuhua , Sun Zhijun , Zhao Can , Dong Ruiqing , Gao Huikuan , Wu Yongquan
Published: December 2016

Background

Premature ventricular contractions (PVCs) from the right ventricular outflow tract (RVOT) can resist conventional mapping strategies. Studies regarding optimal mapping and ablation methods for patients with noninducible RVOT‐PVCs are limited. We retrospectively evaluated the efficacy and safety of a novel mapping strategy for these cases: voltage mapping combined with pace mapping.

Hypothesis

Methods

We retrospectively included symptomatic patients (n = 148; 76 males; age, 44.5 ± 1.4 years) with drug‐refractory PVCs originating from the RVOT, who underwent radiofrequency catheter ablation (RFCA), and stratified them as Group 1 and Group 2. Group 1 patients had noninducible RVOT‐PVCs, determined after programmed stimulation, burst pacing, and isoproterenol infusion (n = 21; 12 males; age, 39.5 ± 10.8 years). Group 2 patients had inducible PVCs. Group 1 patients were subjected to voltage mapping combined with pace mapping; Group 2 underwent conventional mapping. In all patients prior to RFCA, detailed 3‐dimensional electroanatomic voltage maps of the RVOT were obtained during sinus rhythm using the CARTO system.

Results

Patients from both groups had similar success and complication rates associated with the RFCA. In Group 2, 89% (113/127) experienced the earliest and the successful ablation points in the voltage transitional zone. During the follow‐up (36 ± 8 months), patients from both groups suffered similar rates of PVC relapse (2/21 and 7/127, respectively; P = 0.826).

Conclusions

Voltage mapping combined with pace mapping is effective and safe for patients with noninducible RVOT‐PVCs determined by conventional methods.
Impact of diabetes on mortality in peripheral artery disease: a meta‐analysis
Authors: Vrsalovic Mislav , Vucur Ksenija , Vrsalovic Presecki Ana , Fabijanic Damir , Milosevic Milan
Published: December 2016

Background

There are accumulating studies showing the association between diabetes and all‐cause mortality in peripheral vascular disease. However, the results in these studies are conflicting regarding the impact of diabetes on outcome.

Hypothesis

Diabetes is associated with increased risk of mortality in peripheral artery disease.

Methods

Using MEDLINE and Scopus, we searched for studies published before January 2016. Additionally, studies were identified by manual search of references of original articles or review studies on this topic. Of the 1072 initially identified records, 21 studies with 15,857 patients were included in the final analysis.

Results

Diabetes was associated with a statistically significant increased risk of all‐cause mortality (odds ratio: 1.89, 95% confidence interval: 1.51‐2.35, P < 0.001), without detected publication bias (Egger bias = 0.75, P = 0.631). The stronger effect on outcome was obtained in patients with critical limb ischemia (odds ratio: 2.38, 95% confidence interval: 1.22‐4.63, P < 0.001) as the most severe form of peripheral vascular disease.

Conclusions

Diabetes is associated with an increased risk of mortality in peripheral vascular disease, and the effect is even more pronounced in patients with critical limb ischemia.
Expression of programmed cell death‐1 and its ligand B7 homolog 1 in peripheral blood lymphocytes from patients with peripartum cardiomyopathy
Authors: Xia Guozhi , Zheng Xiaopu , Yao Xinye , Yao Xiaowei , Liu Zhongwei , Wang Junkui
Published: December 2016

Background

Immune response has been postulated to play a prominent role in the pathogenesis of peripartum cardiomyopathy (PPCM). Given the importance of programmed death (PD)‐1 and its ligand B7 homologue 1 (B7‐H1) costimulatory molecules as an immune regulatory pathway, this study aimed to investigate the effect of PD‐1 and B7‐H1 expression on immune response in peripheral blood lymphocytes from the patients with PPCM.

Hypothesis

PD‐1 and B7‐H1 may be involved in modulating immune response in PPCM.

Methods

Peripheral blood lymphocytes were obtained from PPCM and pregnancy‐matched healthy women. PD‐1 and B7‐H1 expression were determined using fluorescence quantitative reverse transcription‐polymerase chain reactions (RT‐PCR) and Western blot. The presence of serum interferon (IFN)‐γ and interleukin (IL)‐4 were determined with enzyme‐linked immunosorbent assay.

Results

The levels of pro‐brain natriuretic peptide and IFN‐γ were markedly elevated, whereas the levels of left ventricular ejection fraction and IL‐4 were significantly reduced in PPCM patients compared to controls. Additionally, both RT‐PCR and Western blot revealed that the levels of PD‐1 and B7‐H1 expression were decreased significantly in PPCM patients compared with controls. A significant positive correlation was observed between PD‐1 and B7‐H1 expression. Furthermore, PD‐1 and B7‐H1 expression showed significant negative correlation with IFN‐γ, as well as positive correlation with IL‐4. Therefore, decreased expression of PD‐1 and B7‐H1 led to a dysregulating immune response such that cellular immunity linked to T helper (Th)1 cells was predominant over humoral immunity linked to Th2 cells in PPCM.

Conclusions

This study provided the first findings that PD‐1 and B7‐H1 expression were decreased, which might impair functional regulation of negative costimulation on immune response that may work in the etiopathogenesis of PPCM.
Evaluation of left ventricular diastolic function profile in patients with pulmonary hypertension due to heart failure with preserved ejection fraction
Authors: Raeisi‐Giglou Pejman , Lam Louis , Tamarappoo Balaji K. , Newman Jennie , Dweik Raed A. , Tonelli Adriano R.
Published: December 2016

Background

Echocardiography plays an important role in the diagnostic work up of heart failure with preserved ejection fraction (HFpEF). We sought to determine the left ventricular (LV) diastolic profile by echocardiography in patients diagnosed with pulmonary hypertension (PH) due to PH‐HFpEF.

Hypothesis

The study of LV diastolic function by echocardiography has limitations in patients with HFpEF and PH, and certain LV diastolic determinations convey a worse prognosis.

Methods

We included patients with postcapillary PH and diagnosis of PH‐HFpEF. Investigators reviewed Doppler echocardiograms completed within 3 months of the diagnostic right heart catheterization.

Results

We included 149 patients with a mean ± standard deviation age of 63 ± 14 years; 58% were women. LV diastolic function profile was determined as normal (41%), grade I (34%), and grade II and grade III (25%). Pulmonary artery pressure and pulmonary vascular resistance were higher and cardiac output lower in patients with LV diastolic dysfunction profile; however, pulmonary artery wedge pressure was not significantly different among grades of LV diastolic function. Although there was an association between the presence of LV diastolic dysfunction profile and long‐term survival (P = 0.03), it disappeared when adjusting for age and gender. Right ventricular (RV) dysfunction, paradoxical septal motion, and higher RV systolic pressure remained the only variables significantly associated with poor survival.

Conclusions

The profile of LV diastolic dysfunction by conventional echocardiography is highly variable in patients with PH‐HFpEF and has no significant impact on long‐term survival. A more severe RV function and higher right ventricle systolic pressure were associated with worse survival.