bluuebunny/crossref_metadata_2025 huggingface dataset:
GPS phase scintillation at high latitudes during the geomagnetic storm of 17–18 March 2015
Authors: Prikryl P. , Ghoddousi‐Fard R. , Weygand J. M. , Viljanen A. , Connors M. , Danskin D. W. , Jayachandran P. T. , Jacobsen K. S. , Andalsvik Y. L. , Thomas E. G. , Ruohoniemi J. M. , Durgonics T. , Oksavik K. , Zhang Y. , Spanswick E. , Aquino M. , Sreeja V.
Published: October 2016

The geomagnetic storm of 17–18 March 2015 was caused by the impacts of a coronal mass ejection and a high‐speed plasma stream from a coronal hole. The high‐latitude ionosphere dynamics is studied using arrays of ground‐based instruments including GPS receivers, HF radars, ionosondes, riometers, and magnetometers. The phase scintillation index is computed for signals sampled at a rate of up to 100 Hz by specialized GPS scintillation receivers supplemented by the phase scintillation proxy index obtained from geodetic‐quality GPS data sampled at 1 Hz. In the context of solar wind coupling to the magnetosphere‐ionosphere system, it is shown that GPS phase scintillation is primarily enhanced in the cusp, the tongue of ionization that is broken into patches drawn into the polar cap from the dayside storm‐enhanced plasma density, and in the auroral oval. In this paper we examine the relation between the scintillation and auroral electrojet currents observed by arrays of ground‐based magnetometers as well as energetic particle precipitation observed by the DMSP satellites. Equivalent ionospheric currents are obtained from ground magnetometer data using the spherical elementary currents systems technique that has been applied over the ground magnetometer networks in North America and North Europe. The GPS phase scintillation is mapped to the poleward side of strong westward electrojet and to the edge of the eastward electrojet region. Also, the scintillation was generally collocated with fluxes of energetic electron precipitation observed by DMSP satellites with the exception of a period of pulsating aurora when only very weak currents were observed.
Focal spot imaging based on zero lag cross‐correlation amplitude fields: Application to dense array data at the San Jacinto fault zone
Authors: Hillers G. , Roux P. , Campillo M. , Ben‐Zion Y.
Published: October 2016

We image the subsurface below a dense seismic array straddling the Clark branch of the San Jacinto fault zone in Southern California. The analysis is based on focal spots of surface waves associated with the zero lag amplitudes of noise cross‐correlations computed between all stations of the dense array. Local medium properties are inferred from the spatially variable focal spot size and shape based on the first zero crossing of amplitude versus distance distributions. The method provides simultaneous estimates of wave speed, apparent attenuation, and anisotropy without solving a tomographic inverse problem. The obtained images of the frequency dependent seismic velocity distributions are consistent with independent estimates from a far‐field Rayleigh wave tomography. We observe an anticorrelation between our apparent attenuation coefficient and seismic velocity, and a fault‐parallel alignment of fast propagation directions with greater structural complexity to the southwest of the fault. The results imply a complex fault zone structure including a waveguide to the northeast of the fault that is continuous across the observed depth range and a low‐velocity structure to the southwest associated with a shallow sedimentary basin.
Effects of turbulence‐induced collision enhancement on heavy precipitation: The 21 September 2010 case over the Korean Peninsula
Authors: Lee Hyunho , Baik Jong‐Jin
Published: October 2016

The effects of turbulence‐induced collision enhancement (TICE) on a heavy precipitation event that occurred on 21 September 2010 over the middle Korean Peninsula are examined. For this purpose, an updated bin microphysics scheme incorporating TICE for drop‐drop and drop‐graupel collisions is implemented into the Weather Research and Forecasting (WRF) model. The numerical simulation shows some differences in the strong precipitation system compared to the observations but generally captures well the important features of observed synoptic conditions, surface precipitation, and radar reflectivity. While the change in domain‐averaged surface precipitation amount due to TICE is small and similar to that due to small initial perturbations, the spatial distribution of surface precipitation amount is somewhat altered due to TICE. The surface precipitation amount is increased due to TICE in the area where the largest surface precipitation occurred, but the effects of different flow realizations also contribute to the changes. TICE accelerates the coalescence between small cloud droplets, which induces a decrease in condensation and an increase in excess water vapor transported upward. This causes an increase in relative humidity with respect to ice at high altitudes, hence increasing the depositional growth of ice particles. Therefore, the ice mass increases due to TICE, and this increase induces the increases in riming and melting of ice particles. A series of these microphysical changes due to TICE are regarded as partially contributing to the increase in surface precipitation amount in some areas, hence inducing alterations in the spatial distribution of surface precipitation amount.
WWLLN lightning and satellite microwave radiometrics at 37 to 183 GHz: Thunderstorms in the broad tropics
Authors: Solorzano N. N. , Thomas J. N. , Hutchins M. L. , Holzworth R. H.
Published: October 2016

We investigate lightning strokes and deep convection through the examination of cloud‐to‐ground (CG) lightning from the World Wide Lightning Location Network (WWLLN) and passive microwave radiometer data. Microwave channels at 37 to 183.3 GHz are provided by the Tropical Rainfall Measuring Mission satellite (TRMM) Microwave Imager (TMI) and the Special Sensor Microwave Imager/Sounder (SSMIS) on the Defense Meteorological Satellite Program (DMSP) satellite F16. The present study compares WWLLN stroke rates and minimum radiometer brightness temperatures (Tbs) for two Northern Hemisphere and Southern Hemisphere summers (2009–2011) in the broad tropics (35°S to 35°N). To identify deep convection, we use lightning data and Tbs derived from all channels and differences in the Tbs (ΔTbs) of the three water vapor channels near 183.3 GHz. We find that stroke probabilities increase with increasing Tb depressions for all frequencies examined. Moreover, we apply methods that use the 183.3 GHz channels to pinpoint deep convection associated with lightning. High lightning stroke probabilities are found over land regions for both intense and relatively weak convective systems, although the TMI 85 GHz results should be used with caution as they are affected by a 7 km gap between the conical scans. Over the ocean, lightning is associated mostly with larger Tb depressions. Generally, our results support the noninductive thundercloud charging mechanism but do not rule out the inductive mechanism during the mature stages of storms. Lastly, we present a case study in which lightning stroke rates are used to reconstruct microwave radiometer Tbs.
Simulation of orographic effects with a Quasi‐3‐D Multiscale Modeling Framework: Basic algorithm and preliminary results
Authors: Jung Joon‐Hee
Published: October 2016

The global atmospheric models based on the Multi‐scale Modeling Framework (MMF) are able to explicitly resolve subgrid‐scale processes by using embedded 2‐D Cloud‐Resolving Models (CRMs). Up to now, however, those models do not include the orographic effects on the CRM grid scale. This study shows that the effects of CRM grid‐scale orography can be simulated reasonably well by the Quasi‐3‐D MMF (Q3D MMF), which has been developed as a second‐generation MMF. In the Q3D framework, the surface topography can be included in the CRM component by using a block representation of the mountains, so that no smoothing of the topographic height is necessary. To demonstrate the performance of such a model, the orographic effects over a steep mountain are simulated in an idealized experimental setup with each of the Q3D MMF and the full 3‐D CRM. The latter is used as a benchmark. Comparison of the results shows that the Q3D MMF is able to reproduce the horizontal distribution of orographic precipitation and the flow changes around mountains as simulated by the 3‐D CRM, even though the embedded CRMs of the Q3D MMF recognize only some aspects of the complex 3‐D topography. It is also shown that the use of 3‐D CRMs in the Q3D framework, rather than 2‐D CRMs, has positive impacts on the simulation of wind fields but does not substantially change the simulated precipitation.
International Retrospective Chart Review of Treatment Patterns in Severe Familial Mediterranean Fever, Tumor Necrosis Factor Receptor–Associated Periodic Syndrome, and Mevalonate Kinase Deficiency/Hyperimmunoglobulinemia D Syndrome
Authors: Ozen Seza , Kuemmerle‐Deschner Jasmin B. , Cimaz Rolando , Livneh Avi , Quartier Pierre , Kone‐Paut Isabelle , Zeft Andrew , Spalding Steve , Gul Ahmet , Hentgen Veronique , Savic Sinisa , Foeldvari Ivan , Frenkel Joost , Cantarini Luca , Patel Dony , Weiss Jeffrey , Marinsek Nina , Degun Ravi , Lomax Kathleen G. , Lachmann Helen J.
Published: October 2016

Objective

Periodic fever syndrome (PFS) conditions are characterized by recurrent attacks of fever and localized inflammation. This study examined the diagnostic pathway and treatments at tertiary centers for familial Mediterranean fever (FMF), tumor necrosis factor receptor–associated periodic syndrome (TRAPS), and mevalonate kinase deficiency (MKD)/hyperimmunoglobulinemia D syndrome (HIDS).

Methods

PFS specialists at medical centers in the US, the European Union, and the eastern Mediterranean participated in a retrospective chart review, providing de‐identified data in an electronic case report form. Patients were treated between 2008 and 2012, with at least 1 year of followup; all had clinical and/or genetically proven disease and were on/eligible for biologic treatment.

Results

A total of 134 patients were analyzed: FMF (n = 49), TRAPS (n = 47), and MKD/HIDS (n = 38). Fever was commonly reported as severe across all indications. Other frequently reported severe symptoms were serositis for FMF patients and elevated acute‐phase reactants and gastrointestinal upset for TRAPS and MKD/HIDS. A long delay from disease onset to diagnosis was seen within TRAPS and MKD/HIDS (5.8 and 7.1 years, respectively) compared to a 1.8‐year delay in FMF patients. An equal proportion of TRAPS patients first received anti–interleukin‐1 (anti‐IL‐1) and anti–tumor necrosis factor (anti‐TNF) biologic agents, whereas IL‐1 blockade was the main choice for FMF patients resistant to colchicine and MKD/HIDS patients. For TRAPS patients, treatment with anakinra versus anti‐TNF treatments as first biologic agent resulted in significantly higher clinical and biochemical responses (P = 0.03 and P < 0.01, respectively). No significant differences in responses were observed between biologic agents among other cohorts.

Conclusion

Referral patterns and diagnostic delays highlight the need for greater awareness and improved diagnostics for PFS. This real‐world treatment assessment supports the need for further refinement of treatment practices.
Subfertility in Women With Rheumatoid Arthritis and the Outcome of Fertility Assessments
Authors: Brouwer Jenny , Fleurbaaij Rosalie , Hazes Johanna M. W. , Dolhain Radboud J. E. M. , Laven Joop S. E.
Published: October 2016

Objective

Subfertility is frequently encountered among female rheumatoid arthritis (RA) patients and has been associated with disease activity and antirheumatic drugs. However, little is known about the results of the fertility assessments in these women. Our aim was to study the outcome of fertility assessments in subfertile women with RA.

Methods

A cross‐sectional study was performed in a nationwide cohort of female RA patients who were pregnant or trying to conceive between 2002 and 2010 (Pregnancy‐Induced Amelioration of Rheumatoid Arthritis Study). Patients who had given consent for future contact (n = 260) received a questionnaire on reproductive history, fertility examinations, and fertility treatments. Medical files were obtained from attending gynecologists.

Results

A completed questionnaire was returned by 178 women (68%), of whom 96% had ended their efforts to conceive. Eighty‐two subjects (46%) had at least 1 subfertile episode, and for 61 women a diagnosis for subfertility was available. Unexplained subfertility (48%) and anovulation (28%) were the most common gynecologic diagnoses, and both occurred more often in RA patients than reported in the general population. Women with unexplained subfertility more often used nonsteroidal antiinflammatory drugs (NSAIDs) during the periconceptional period. Seventeen percent of all pregnancies were conceived after fertility treatments. Fertility treatments had equal or higher pregnancy rates in RA compared to other subfertile populations.

Conclusion

Unexplained subfertility is more often diagnosed in subfertile female RA patients than in the general population, and is related to periconceptional NSAID use. Despite the higher incidence of subfertility in women with RA, the outcome of fertility treatments in these women appears favorable.
Cold Metal Transfer Welding–Brazing of Pure Titanium TA2 to Aluminum Alloy 6061‐T6
Authors: Li Junzhao , Sun Qingjie , Liu Yibo , Cai Chunwei , Feng Jicai
Published: October 2016

Pure titanium TA2 and aluminum alloy 6061‐T6 are joined using AlSi5 filler wire by cold metal transfer (CMT) process in the form of two lap configurations. Results indicate that these two various lap joints are both composed of fusion welded joint and brazing joint. The fusion welded joint consists of α‐Al solid solution and Al–Si eutectic. Brazing joint is formed between local molten Ti base metal and weld metal, which produces a certain thickness of reaction layer. Al–Ti joint only has one joining interface with a thickness of 1–5 μm and the optimum tensile strength can reach up to 305.5 N mm−1, while Ti–Al joint forms three joining interfaces with tensile strength of 168.2 N mm−1. Moreover, Al–Ti joint fractures at the weld metal with plastic fracture mode, while Ti–Al joint fractures at joining interface.
In Vitro Topographical Model of Fuchs Dystrophy for Evaluation of Corneal Endothelial Cell Monolayer Formation
Authors: Rizwan Muhammad , Peh Gary S. , Adnan Khadijah , Naso Sacha L. , Mendez Alon R. , Mehta Jodhbir S. , Yim Evelyn K. F.
Published: October 2016

A common indication for corneal transplantation, which is the most transplanted tissue, is a dysfunctional corneal endothelium due to Fuchs' endothelial dystrophy (FED). FED is diagnosed by the presence of in vivo pathological microtopography on the Descemet membrane, which is called corneal guttata. Minimally invasive corneal endothelial cell regenerative procedures such as endothelial cell injection therapy and Rho kinase inhibitor pharmacotherapy have been proposed as alternatives to conventional corneal transplantation for FED patients. However, the effect of guttata on monolayer reformation following such therapies is unknown and there is no equivalent in vitro or animal model to study monolayer reformation. Using a synthetic guttata FED disease model, the formation of the monolayer is investigated to evaluate the efficacy of both therapies. Results obtained suggest that guttata dimensions, density, and spacing greatly affect the fate of corneal endothelial cells in terms of migratory behavior and monolayer reformation. Densely packed synthetic guttata mimicking late‐stage FED hinders monolayer reformation, while synthetic guttata of lower height and density show improved monolayer formation. These results suggest that severity of the FED, as determined by height and density of existing guttata, can potentially attenuate corneal endothelial monolayer formation of corneal cell injection therapy and pharmacotherapy.
All‐Carbon Thin‐Film Transistors as a Step Towards Flexible and Transparent Electronics
Authors: Sun Dong‐Ming , Liu Chang , Ren Wen‐Cai , Cheng Hui‐Ming
Published: October 2016

Carbon nanotubes and graphene have attracted great attention for potential applications in flexible and transparent electronics, owing to their exceptional properties including very high electrical conductivity, optical transmittance, mechanical strength and flexibility. Thin films of carbon nanotubes or graphene are promising for fabricating high‐quality semiconducting channels and transparent conductive films, as electrodes and interconnects in thin‐film transistors and integrated circuits, which allows the construction of all‐carbon electronics. This article reviews the main approaches to and important findings in the fabrication of flexible and transparent electrodes and channels for thin‐film transistors, and highlights recent achievements of flexible and transparent all‐carbon thin‐film transistors, in terms of design, fabrication and performance evaluation. This all‐carbon strategy opens up a way to achieve extremely flexible, transparent and stretchable electronics with relatively low cost and fast fabrication techniques, compared to the traditional rigid silicon, metal and metal oxide electronics.
Task distribution, work environment, and perceived health discomforts among Indian ceramic workers
Authors: Majumder Joydeep , Shah Priyanka , Bagepally Bhavani S.
Published: October 2016

Background

The study examined the work environment of Indian ceramics workers and assessed associations between work hazards, work category, and self‐reported symptoms.

Methods

The multi‐method ergonomic review technique (MMERT) checkpoints was used for work analysis and prevalence of self‐reported symptoms among 329 male workers.

Results

Ambient temperature and relative humidity in ceramic industries were 39.9°C and 17.4% respectively. Musculoskeletal discomfort was observed as a primary complaint; especially lower extremity pain (45%). Load handlers and machine operators had the highest levels of work hazards, including high skill requirement, strenuous work posture, poor commitment by the organization. Poor job autonomy, task clarity, hot workplace, inappropriate workplace design, inadequate auxiliary support, and mental overload were significantly associated with self‐reported symptoms (P < 0.001).

Conclusion

Work categories are associated with work hazards and may lead to various health symptoms among ceramic workers. Control of workplace hazards may lower rates of symptoms and thus may lead to improved health, productivity, and well‐being. Am. J. Ind. Med. 59:1145–1155, 2016. © 2016 Wiley Periodicals, Inc.
Palladium‐Catalyzed Heterocyclization: A Carbon‐Centered Approach
Authors: Phillips David , France David J.
Published: October 2016

Heterocycles are some of the most important and widely used motifs in synthetic and medicinal chemistry. It is therefore not surprising that the synthesis of heterocycles is a rich area of chemical research. Catalytic heterocyclization that makes use of heteroatomic nucleophiles, such as oxygen and nitrogen, is one such powerful strategy. This Focus Review considers an alternative approach that uses carbon‐based nucleophiles that are generated during palladium‐catalyzed heterocyclization reactions. This complimentary method allows access to a range of useful and otherwise‐inaccessible targets. Occurring through a range of different mechanisms, the utility of this approach can be seen in the wide range of transformations that can be undertaken, along with its repeated application in the synthesis of complex molecules.
Integrating feeding behavior, ecological data, and DNA barcoding to identify developmental differences in invertebrate foraging strategies in wild white‐faced capuchins (Cebus capucinus)
Authors: Mallott Elizabeth K. , Garber Paul A. , Malhi Ripan S.
Published: October 2016

Objectives

Invertebrate foraging strategies in nonhuman primates often require complex extractive foraging or prey detection techniques. As these skills take time to master, juveniles may have reduced foraging efficiency or concentrate their foraging efforts on easier to acquire prey than adults.

Materials and methods

We use DNA barcoding, behavioral observations, and ecological data to assess age‐based differences in invertebrate prey foraging strategies in a group of white‐faced capuchins (Cebus capucinus) in northeastern Costa Rica. Invertebrate availability was monitored using canopy traps and sweep netting. Fecal samples were collected from adult female, adult male, and juvenile white‐faced capuchins (n = 225).COImtDNA sequences were compared with known sequences in GenBank and the Barcode of Life Database.

Results

Frequencies of Lepidoptera and Hymenoptera consumption were higher in juveniles than in adults. A significantly smaller proportion of juvenile fecal samples contained Gryllidae and Cercopidae sequences, compared with adults (0% and 4.2% vs. 4.6% and 12.5%), and a significantly larger proportion contained Tenthredinidae, Culicidae, and Crambidae (5.6%, 9.7%, and 5.6% vs. 1.3%, 0.7%, and 1.3%). Juveniles spent significantly more time feeding and foraging than adults, and focused their foraging efforts on prey that require different skills to capture or extract. Arthropod availability was not correlated with foraging efficiency, and the rate of consumption of specific orders of invertebrates was not correlated with the availability of those same taxa.

Discussion

Our data support the hypothesis that juveniles are concentrating their foraging efforts on different prey than adults, potentially focusing their foraging efforts on more easily acquired types of prey.
Repair of caudal septal deviation: the fishing line technique
Authors: Yaniv Dan , Hadar Tuvia , Hod Roe , Lansberg Roee , Koren Ilan , Yaniv Eitan
Published: October 2016

Background

Repair of caudal septal deviation using currently described methods is challenging technically. The aim of this work is to describe a novel and simple technique for the treatment of caudal septal deviations that protects the nasal tip, by fixating of cartilage to the columella.

Methods

All patients with caudal septal deviation operated on between June 2008 to November 2013 in 2 major medical centers were operated using the “fishing line technique.” Patient satisfaction was recorded by a standard questionnaire (16‐item Sino‐Nasal Outcome Test [SNOT‐16]), before and after surgery. The fishing line technique was performed in 63 patients with a severe caudal septal deviation of which 14 also had rhinoplasty. A mucoperichondrial flap was elevated on either side of the damaged septal cartilage. The cartilage was excised and remodeled into a straight sheet, and then repositioned between the mucoperichondrial flaps, and fixed to the septal columella.

Results

Mean age of the study group was 36 years. Follow‐up ranged from 24 to 70 months. At the last follow‐up, the septum was straight in all cases, with no deviation from the nostrils to the choana. Good airway was found in 53 patients. Eight patients had partial turbinate hypertrophy with an impaired airway, and 2 had severe turbinate hypertrophy. SNOT‐16 mean score improved from 27 to 10 (p < 0.001). All patients were satisfied with the aesthetic outcome.

Conclusion

The fishing‐line technique for severe caudal septum deviations is easy to perform and yields satisfactory anatomic and aesthetic results.
The Origin of Improved Electrical Double‐Layer Capacitance by Inclusion of Topological Defects and Dopants in Graphene for Supercapacitors
Authors: Chen Jiafeng , Han Yulei , Kong Xianghua , Deng Xinzhou , Park Hyo Ju , Guo Yali , Jin Song , Qi Zhikai , Lee Zonghoon , Qiao Zhenhua , Ruoff Rodney S. , Ji Hengxing
Published: October 2016

Low‐energy density has long been the major limitation to the application of supercapacitors. Introducing topological defects and dopants in carbon‐based electrodes in a supercapacitor improves the performance by maximizing the gravimetric capacitance per mass of the electrode. However, the main mechanisms governing this capacitance improvement are still unclear. We fabricated planar electrodes from CVD‐derived single‐layer graphene with deliberately introduced topological defects and nitrogen dopants in controlled concentrations and of known configurations, to estimate the influence of these defects on the electrical double‐layer (EDL) capacitance. Our experimental study and theoretical calculations show that the increase in EDL capacitance due to either the topological defects or the nitrogen dopants has the same origin, yet these two factors improve the EDL capacitance in different ways. Our work provides a better understanding of the correlation between the atomic‐scale structure and the EDL capacitance and presents a new strategy for the development of experimental and theoretical models for understanding the EDL capacitance of carbon electrodes.
Netzwerke aus Supertetraedern und Lithiumionenbeweglichkeit in Li2SiP2 und LiSi2P3
Authors: Haffner Arthur , Bräuniger Thomas , Johrendt Dirk
Published: October 2016

Die neuen Phosphidosilicate Li2SiP2 und LiSi2P3 wurden aus den Elementen bei 1123 K synthetisiert und durch Einkristallstrukturanalyse charakterisiert. Li2SiP2 (I41/acd, Z=32, a=12.111(1) Å, c=18.658(2) Å) enthält zwei sich durchdringende Diamant‐analoge Tetraedernetzwerke aus eckenverknüpften T2‐Supertetraedern [(SiP4/2)4]. In der komplexen Struktur von LiSi2P3 (I41/a, Z=100, a=18.4757(3) Å, c=35.0982(6) Å) liegen Sphalerit‐analoge sich durchdringende Netzwerke aus T4‐ und T5‐Supertetraedern mit je einer gemeinsamen SiP4‐Gruppe vor. Lithium ist in den Zwischenräumen der Supertetraeder durch vier bis sechs Phosphoratome koordiniert. Temperaturabhängige 7Li‐MAS‐NMR‐Spektren deuten auf eine hohe Beweglichkeit der Li+‐Ionen mit geringen Aktivierungsenergien von 0.1 eV für Li2SiP2 und 0.07 eV für LiSi2P3.
C(sp3)−H Oxidative Addition and Transfer Hydrogenation Chemistry of a Titanium(II) Synthon: Mimicry of Late‐Metal Type Reactivity
Authors: Aguilar‐Calderón J. Rolando , Metta‐Magaña Alejandro J. , Noll Bruce , Fortier Skye
Published: October 2016

Two‐electron reduction of the TiIV compound (ketguan)(ImDippN)Ti(OTf)2 (3) gives the arene‐masked complex (ketguan)(η6‐ImDippN)Ti (1) in excellent yield. Upon standing in solution, 1 converts to a TiIV metallacycle (4) through dehydrogenation of a pendant isopropyl group. Spectroscopic evidence shows this transformation initially proceeds via the oxidative addition of a C(sp3)−H bond and can be reversed upon exposure of 4 to H2. Interestingly, treatment of 1 with cyclohexene gives cyclohexane and 4 via a titanium‐mediated transfer hydrogenation reaction, a process that can be extended to catalytically hydrogenate other unsaturated hydrocarbons under mild conditions. These results, rare for the early‐metals, suggest 1 possesses chemical characteristics reminiscent of noble, late‐metals.
Vesikel in der Natur und im Labor: die Aufklärung der biologischen Eigenschaften und die Synthese zunehmend komplexer synthetischer Vesikel
Authors: Fernandez‐Trillo Francisco , Grover Liam M. , Stephenson‐Brown Alex , Harrison Paul , Mendes Paula M.
Published: October 2016

Die wichtige Rolle von Vesikeln in vielen Bereichen der Zellfunktion ist gut bekannt, aber erst seit kurzem offenbart sich mithilfe neuer, komplexerer Bildgebungsverfahren ihre Allgegenwart in der Natur. Während die biologischen Eigenschaften von Vesikeln und ihre physiologischen Funktionen immer besser verstanden werden, werden auch vermehrt sehr elegante, künstliche Vesikel für eine Reihe technischer Anwendungen und die Grundlagenforschung entwickelt. Hier wollen wir den Stand der Technik von biologischen und synthetischen Vesikeln darstellen und ihre biologischen Eigenschaften in Zusammenhang mit aktuellen Syntheseentwicklungen bringen, um so einen Überblick über diese komplexen, rasch aufstrebenden Fachgebiete zu geben. Darüber hinaus werden die Herausforderungen und Möglichkeiten für die zukünftige biologische und präparative Entwicklung von Vesikeln präsentiert.
Das Zusammenspiel zwischen einer multifunktionalen Dehydratase‐Domäne und einer C‐Methyltransferase bewirkt die Doppelbindungsverschiebung in der Ambruticin‐Biosynthese
Authors: Berkhan Gesche , Merten Christian , Holec Claudia , Hahn Frank
Published: October 2016

Die Doppelbindungsverschiebung ist eine wichtige Modifizierung während der Polyketidbiosynthese. Insbesondere für cis‐AT‐PKS vom Typ I ist nur wenig über die enzymatischen Mechanismen bekannt. Wir präsentieren unsere In‐vitro‐Studien zur Doppelbindungsverschiebung während der Ambruticin‐Biosynthese. Die multifunktionale AmbDH4‐Domäne katalysiert aufeinander folgende Dehydratisierung, Epimerisierung und Enoylisomerisierung. Das erhaltene 3‐Enthioat wird durch α‐Methylierung, katalysiert durch die C‐Methyltransferase AmbM, aus dem Gleichgewicht entfernt. Dieser thermodynamisch eigentlich ungünstige Prozess wird jedoch durch die hohe und aufeinander abgestimmte Substratspezifität der beteiligten Enzyme ermöglicht. AmbDH4 ist eng verwandt mit DH‐Domänen, wobei erste mechanistische Studien vermuten lassen, dass die Doppelbindungsisomerisierung, ähnlich wie bei EI‐Domänen aus trans‐AT‐PKS, über die Verschiebung eines einzelnen Protons verläuft.
A Ruthenium(III)–Oxyl Complex Bearing Strong Radical Character
Authors: Shimoyama Yoshihiro , Ishizuka Tomoya , Kotani Hiroaki , Shiota Yoshihito , Yoshizawa Kazunari , Mieda Kaoru , Ogura Takashi , Okajima Toshihiro , Nozawa Shunsuke , Kojima Takahiko
Published: October 2016

Proton‐coupled electron‐transfer oxidation of a RuII−OH2 complex, having an N‐heterocyclic carbene ligand, gives a RuIII−O. species, which has an electronically equivalent structure of the RuIV=O species, in an acidic aqueous solution. The RuIII−O. complex was characterized by spectroscopic methods and DFT calculations. The oxidation state of the Ru center was shown to be close to +3; the Ru−O bond showed a lower‐energy Raman scattering at 732 cm−1 and the Ru−O bond length was estimated to be 1.77(1) Å. The RuIII−O. complex exhibits high reactivity in substrate oxidation under catalytic conditions; particularly, benzaldehyde and the derivatives are oxidized to the corresponding benzoic acid through C−H abstraction from the formyl group by the RuIII−O. complex bearing a strong radical character as the active species.
DNA‐Accelerated Catalysis of Carbene‐Transfer Reactions by a DNA/Cationic Iron Porphyrin Hybrid
Authors: Rioz‐Martínez Ana , Oelerich Jens , Ségaud Nathalie , Roelfes Gerard
Published: October 2016

A novel DNA‐based hybrid catalyst comprised of salmon testes DNA and an iron(III) complex of a cationic meso‐tetrakis(N‐alkylpyridyl)porphyrin was developed. When the N‐methyl substituents were placed at the ortho position with respect to the porphyrin ring, high reactivity in catalytic carbene‐transfer reactions was observed under mild conditions, as demonstrated in the catalytic enantioselective cyclopropanation of styrene derivatives with ethyl diazoacetate (EDA) as the carbene precursor. A remarkable feature of this catalytic system is the large DNA‐induced rate acceleration observed in this reaction and the related dimerization of EDA. It is proposed that high effective molarity of all components of the reaction in or near the DNA is one of the key contributors to this unique reactivity. This study demonstrates that the concept of DNA‐based asymmetric catalysis can be expanded into the realm of organometallic chemistry.
Aromatic Osmacyclopropenefuran Bicycles and Their Relevance for the Metal‐Mediated Hydration of Functionalized Allenes
Authors: Batuecas María , Castro‐Rodrigo Ruth , Esteruelas Miguel A. , García‐Yebra Cristina , López Ana M. , Oñate Enrique
Published: October 2016

The aromatic osmacyclopropenefuran bicycles [OsTp{κ3‐C1,C2,O‐(C1H2C2CHC(OEt)O)}(PiPr3)]BF4 (Tp=hydridotris(1‐pyrazolyl)borate) and [OsH{κ3‐C1,C2,O‐(C1H2C2CHC(OEt)O)}(CO)(PiPr3)2]BF4, with the metal fragment in a common vertex between the fused three‐ and five‐membered rings, have been prepared via the π‐allene intermediates [OsTp(η2‐CH2=CCHCO2Et)(OCMe2)(PiPr3)]BF4 and [OsH(η2‐CH2=CCHCO2Et)(CO)(OH2)(PiPr3)2]BF4, and their aromaticity analyzed by DFT calculations. The bicycle containing the [OsH(CO)(PiPr3)2]+ metal fragment is a key intermediate in the [OsH(CO)(OH2)2(PiPr3)2]BF4‐catalyzed regioselective anti‐Markovnikov hydration of ethyl buta‐2,3‐dienoate to ethyl 4‐hydroxycrotonate.
Pentaindenocorannulene: Properties, Assemblies, and C60 Complex
Authors: Lampart Samuel , Roch Loïc M. , Dutta Amit K. , Wang Yujia , Warshamanage Rangana , Finke Aaron D. , Linden Anthony , Baldridge Kim K. , Siegel Jay S.
Published: October 2016

Pentaindenocorannulene (C50H20 , 1), a deep bowl polynuclear aromatic hydrocarbon, accepts 4 electrons, crystallizes in columnar bowl‐in‐bowl assemblies and forms a nested C60@12 complex. Spectra, structures and computations are presented.
Alkyne cellulose for Huisgen [3 + 2] cycloaddition with azido‐terminated targets
Authors: Cao Liangcheng , Wang Yuechuan
Published: October 2016

Azido‐grafted cellulose has been reported widely applied for further functionalization by click chemistry. As an alternative method, we proposed alkyne‐grafted cellulose as a prototype molecule for Huisgen [3 + 2] cycloaddition with azido‐terminated target compounds. Alkyne cellulose was synthesized by acylation with prop‐2‐ynyl 5‐chloro‐5‐oxopentanoate and, subsequently cycloaddition with 4‐aminophenylazide, ethyl 2‐azidoacetate, and (S)‐2‐(Azidomethyl)‐1‐(tert‐butoxycarbonyl)pyrrolidine (Boc‐pyrrolidine azide) to form triazole cellulose in a click manner. The reactions were confirmed qualitatively by Fourier transform infrared and NMR spectroscopy and analyzed quantitatively with elemental analysis data. The results show that a degree of substitution of up to 1.91 was obtained for esterification and, in most cases, was preferred completely in a selective way for the primary hydroxyl groups at the O‐6 position and partially at the O‐2 and O‐3 positions. Cycloaddition conversions were found as high as 0.95, 0.99, and 0.99 for aniline–triazole cellulose, acetate–triazole cellulose, and Boc‐pyrrolidine‐triazole cellulose, respectively. Both esterification and cycloaddition were undertaken under mild conditions without additional heating. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44410.
Polymorphisms in the F Pocket of HLA–B27 Subtypes Strongly Affect Assembly, Chaperone Interactions, and Heavy‐Chain Misfolding
Authors: Guiliano David B. , North Helen , Panayoitou Eleni , Campbell Elaine C. , McHugh Kirsty , Cooke Fiona G. M. , Silvestre Marine , Bowness Paul , Powis Simon J. , Antoniou Antony N.
Published: October 2016

Objective

HLA–B27 is associated with the inflammatory spondyloarthritides (SpA), although subtypes HLA–B*27:06 and HLA–B*27:09 are not. These subtypes differ from the HLA–B*27:05 disease‐associated allele primarily at residues 114 and 116 of the heavy chain, part of the F pocket of the antigen‐binding groove. Dimerization of HLA–B27 during assembly has been implicated in disease onset. The purpose of this study was to investigate the factors that influence differences in dimerization between disease‐associated and non–disease‐associated HLA–B27 alleles.

Methods

HLA–B*27:05 and mutants resembling the HLA–B*27:06 and 09 subtypes were expressed in the rat C58 T cell line, the human CEM T cell line and its calnexin‐deficient variant CEM.NKR. Immunoprecipitation, pulse–chase experiments, flow cytometry, and immunoblotting were performed to study the assembly kinetics, heavy‐chain dimerization, and chaperone associations.

Results

By expressing HLA–B*27:05, 06‐like, and 09 alleles on a restrictive rat transporter associated with antigen processing background, we demonstrate that a tyrosine expressed at p116, either alone or together with an aspartic acid residue at p114, inhibited HLA–B27 dimerization and increased the assembly rate. F‐pocket residues altered the associations with chaperones of the early major histocompatibility complex class I folding pathway. Calnexin was demonstrated to participate in endoplasmic reticulum (ER) stress–mediated degradation of dimers, whereas the oxidoreductase ERp57 does not appear to influence dimerization.

Conclusion

Residues within the F pocket of the peptide‐binding groove, which differ between disease‐associated and non–disease‐associated HLA–B27 subtypes, can influence the assembly process and heavy‐chain dimerization, events which have been linked to the initiation of disease pathogenesis.
Nanoscale Distribution of Transforming Growth Factor Receptor on Post‐Golgi Vesicle Revealed by Super‐resolution Microscopy
Authors: Ruan Hefei , Yu Jianqiang , Yuan Jinghe , Li Nan , Fang Xiaohong
Published: October 2016

Transforming growth factor‐β (TGF‐β) type II receptor (TβRII) plays a critical role in the initiation of TGF‐β signaling pathway; therefore, the study of its synthesis and transport processes is of great important. In this work, we achieved super‐resolution imaging of a new type of TβRII‐containing post‐Golgi vesicle by our home‐built stimulated emission depletion (STED) microscope. We visualized the ring‐shaped structure of these vesicles containing newly synthesized TβRII in the cytoplasm and characterized their size distribution from 300 to 1000 nm. These vesicles could be swollen by chloroquine treatment. Further investigation revealed that TβRII formed clusters on the outer ring of the post‐Golgi vesicles. This study offers new information on the intracellular transportation of TGF‐β receptors for better understanding its signaling process.
Particle Smoother for Nonlinear Systems With One‐Step Randomly Delayed Measurements
Authors: Yu‐Long Huang , Yong‐Gang Zhang
Published: October 2016

In this paper, a new particle smoother based on forward filtering backward simulation is developed to solve the nonlinear and non‐Gaussian smoothing problem when measurements are randomly delayed by one sampling time. The heart of the proposed particle smoother is computation of delayed posterior filtering density based on stochastic sampling approach, whose particles and corresponding weights are updated in Bayesian estimation framework by considering the one‐step randomly delayed measurement model. The superior performance of the proposed particle smoother as compared with existing methods is illustrated in a numerical example concerning univariate non‐stationary growth model.
Analysis of incoming biomass burning aerosol plumes over southern Brazil
Authors: de Oliveira Aline Macedo , Mariano Glauber Lopes , Alonso Marcelo Félix , Mariano Ericka Voss Chagas
Published: October 2016

We characterized the aerosol particles and their transport to southern Brazil during the austral winter months of June, July, and August from 2002 to 2011. To obtain the aerosol optical depth (AOD) (0.55 μm) and the Ångström exponent (0.47–0.66 μm), we used MODIS data. High values of AOD were observed in 2002, 2005, 2007, and 2010, with the highest values in August. We also used the CCATT–BRAMS model to simulate the AOD in southern Brazil. Both approaches suggest an increase of the AOD in the northwestern part of the region, evidence for the transport of biomass burning plumes from central Brazil.
Optimal design of a short‐turning strategy considering seat availability
Authors: Ji Yuxiong , Yang Xiyu , Du Yuchuan
Published: October 2016

We develop a methodology to optimize the schedule coordination of a full‐stop service pattern and a short‐turning service pattern on a bus route. To capture the influence of bus crowding and seat availability on passengers' riding experience, we develop a Markov model to describe the seat‐searching process of a passenger and an approach to estimate the transition probabilities of the Markov model. An optimization model that incorporates the Markov model is proposed to design the short‐turning strategy. The proposed model minimizes the total cost, which includes operational cost, passengers' waiting time cost and passengers' in‐vehicle travel time cost. Algorithm is developed to produce optimal values of the decision variables. The proposed methodology is evaluated in a case study. Compared with methodologies that ignore the effect of bus crowding, the proposed methodology could better balance bus load along the route and between two service patterns, provide passengers with better riding experience and reduce the total cost. In addition, it is shown that the optimal design of the short‐turning strategy is sensitive to seat capacity. Copyright © 2016 John Wiley & Sons, Ltd.
Monitoring der neuen Schrägseilbrücke über den Chao Phraya, Nonthaburi, Thailand
Authors: Mack Thomas , Geier Roman , Kahl Thomas , Kasper Marcel
Published: October 2016

Im Norden von Bangkok (Thailand) wurde in den letzten Jahren zur Entlastung der umliegenden Straßenzüge in der Provinz Nonthaburi ein neuer Autobahnabschnitt realisiert, dessen Hauptmerkmal eine Extradosed‐Brücke über den Chao Phraya mit einer Gesamtlänge von 460 m darstellt. Das Bauwerk, bestehend aus zwei Pylonen mit goldener Kuppel, trägt mit 96 Schrägseilen einen Hohlkastenquerschnitt, ausgelegt für sechs Fahrstreifen, über den Fluss. Zur Überwachung des Tragverhaltens wurde vom Bauherrn ein umfangreiches Monitoringsystem ausgeschrieben, welches von Schimetta Consult in Kooperation mit DYWIDAG Systems International GmbH optimiert, geplant und umgesetzt wurde. 45 Sensoren überwachen dauerhaft die Temperaturen, Dehnungen und Durchbiegungen der Brücke, Neigungen der Pylone, Öffnung der Fahrbahnübergänge, Windgeschwindigkeiten, Beschleunigungen und Seilkräfte. Die Daten werden automatisiert vor Ort gespeichert, über eine UMTS‐Verbindung auf einen externen Server übermittelt und dem Bauherrn innerhalb weniger min über eine Homepage zur laufenden Kontrolle zur Verfügung gestellt. Darüber hinaus werden die Messdaten in einem halbjährlichen Intervall zusammengefasst und analysiert sowie die Ergebnisse dem Bauherrn in einem Messbericht übermittelt. Das Monitoringsystem zeichnet seit Messbeginn Anfang 2015 zuverlässig Daten auf und ermöglicht so einen guten Einblick in das Tragverhalten des Objekts.
Feuchtemessungen in Bauteilen und anderen Strukturen mit Bluetooth Low Energy
Authors: Köppe Enrico , Moldenhauer Laura , Haamkens Frank , Helmerich Rosemarie
Published: October 2016

Die Langzeitüberwachung von Bauteilen (Structural Health Monitoring, SHM) ging in den letzten Jahren zunehmend von verkabelten Sensoren [1] zu kabellosen Sensornetzwerken (WSN) [2] über. Frühwarnsysteme sollen rechtzeitige Signale senden, wenn Schädigungsprozesse einsetzen, wenn ein Bauteil z. B. zu feucht wird (Deiche, Staumauern), oder wenn Feuchteprozesse in Bauteilen auftreten, die den Transport von schädlichen Stoffen ermöglichen. Mittels handelsüblicher multifunktionaler Sensoren wie einem Bluetooth Low Energy (BLE) wurden erste Machbarkeitsuntersuchungen zur Massenfeuchtemessung durchgeführt. Die untersuchten Parameter sind der sogenannte Received Signal Strength Indicator (RSSI) eines Bluetooth‐Low‐Energy(BLE)‐Signals und die abgestrahlte Sendeleistung eines eingebetteten BLE‐Moduls. Das BLE‐Modul kommuniziert mit einem mobilen smarten Empfänger wie einem Tablet oder einem Smartphone als SmartHub. Die Veränderung des RSS‐Indikators ist ein Maß für die Veränderung der Feuchte im Bauteil, während die ausgesandte Signalstärke konstant bleibt. Wenn das BLE‐Signal einen feuchten Bereich im Baumaterial durchläuft, verändert sich der RSS‐Indikator. Nach erfolgreicher Machbarkeitsstudie wurde nun ein aus dem Netzwerk MI4G (Modern Industry for Germany) zwischen der Bundesanstalt für Materialprüfung und dem Klein‐ und mittelständigen Unternehmen LinTech GmbH heraus beantragtes ZIM‐Projekt bewilligt. Der Bericht zeigt erste Ergebnisse von Voruntersuchungen und gibt einen Ausblick auf weitere Forschungsaktivitäten.
Festakt zur Verleihung des Deutschen Brückenbau preises 2016 und 26. Dresdner Brückenbausymposium
Authors: Stritzke Jürgen
Published: October 2016

Am 14. März d. J. war es wieder so weit: In einem großartigen Festakt wurde der Deutsche Brückenbaupreis 2016 vor über 1 200 Gästen im Hörsaalzentrum der Technischen Universität Dresden verliehen. Diesen bedeutenden Ingenieurpreis hatte die Bundesingenieurkammer gemeinsam mit dem Verband Beratender Ingenieure (VBI) bereits zum sechsten Mal für herausragende Leistungen auf dem Gebiet des Brückenbaus ausgelobt.

Er ging auch diesmal an ganzheitlich gelungene Brückenbauwerke in den beiden Kategorien „Straßen‐ und Eisenbahnbrücken” sowie „Fuß‐ und Radwegbrücken”, die Beiträge zur Baukultur leisten. Die Ingenieure, deren kreative Leistungen maßgeblich zum Entstehen der ausgezeichneten Brückenbauwerke geführt haben, erhielten die Preisskulptur [1]. Der alle zwei Jahre vergebene Ingenieurpreis der Königsdisziplin des Ingenieurbaus steht unter der Schirmherrschaft des BMVI. Hauptsponsor ist die Deutsche Bahn AG. Durch den Festakt führte die vom TV‐Sender rbb bekannte Moderatorin Petra Gute.
Leichte Dachschalen aus Carbonbeton
Authors: Scholzen Alexander , Chudoba Rostislav , Hegger Josef , Will Norbert
Published: October 2016

Für einfach gekrümmte Dachschalen aus Textilbeton wurde eine Herstellmethodik entwickelt, die sowohl den Produktionsprozess im Fertigteilwerk als auch materialgerechte Lösungsansätze für Transport und Montage der filigranen Betonschalen auf der Baustelle umfasst. Darüber hinaus wurde anhand von Prototypen die statische Leistungsfähigkeit der Dachschalen im Bauteilversuch verifiziert und über Sägeschnitte die hohe Ausführungsqualität der hergestellten Fertigteile dokumentiert. Die Anwendung der entwickelten Methoden wurde bei einer Dachkonstruktion aus fünf Carbonbeton‐Dachschalen erfolgreich demonstriert. Die Bauteildicke der 10 m2 großen Fertigteile betrug lediglich 2 cm und unterstreicht so eindrucksvoll die Leistungsfähigkeit und das architektonische Anwendungspotenzial des neuartigen Kompositwerkstoffs.
Luminescence characterization of Dy and Eu doped Na6Mg(SO4)4 phosphors
Authors: Kore Bhushan P. , Pardhi Shilpa A. , Dhoble N. S. , Dhoble S. J. , Swart H. C.
Published: October 2016

A series of single‐phase phosphors based on Na6Mg(SO4)4 (Zeff = 11.70) doped with Dy and Eu was prepared by the wet chemical method. The photoluminescence (PL) and thermoluminescence (TL) properties of Dy3+‐ and Eu3+‐activated Na6Mg(SO4)4 phosphors were investigated. The characteristic emissions of Dy3+ and Eu3+ were observed in the Na6Mg(SO4)4 host. The TL glow curve of the Na6Mg(SO4)4:Dy phosphor consisted of a prominent peak at 234°C and a very small hump at 158°C. The TL sensitivity of the Na6Mg(SO4)4:Dy phosphor was found to be four times less than the commercialized CaSO4:Dy phosphor. The TL dose–response of the Na6Mg(SO4)4:Dy phosphor was studied from a dose range of 5–10 kGy and the linear dose–response was observed up to 1 kGy which is good for a microcrystalline phosphor. Trapping parameters for both the samples were calculated using the Initial Rise and Chen's peak shape methods.