bluuebunny/crossref_metadata_2025 huggingface dataset:
Définir et mesurer l’adhésion à la culture des gangs de rue
Authors: Fredette12 Chantal , Guay Jean-Pierre
Published: October 2014

L’adhésion à la culture des gangs de rue est au nombre des explications de la grande propension au crime des contrevenants associés à ces groupes. Or, peu de personnes se sont penchées spécifiquement sur l’opérationnalisation du concept. Les objectifs de la présente étude sont de définir la culture de gang, de décrire ses composantes et de proposer une mesure de l’adhésion à la culture de gang. D’abord, l’article présente une recension des écrits sur la culture des gangs de rue. Nous proposons une définition et une opérationnalisation du concept de culture de gang. Ensuite, l’article présente le processus de développement d’une mesure de l’adhésion à la culture de gang (MACg). Enfin, l’article fait état des données préliminaires de la MACgqui a été administrée à 204 contrevenants mineurs et adultes. Les résultats des analyses des calculs des coefficients alpha de Cronbach et des corrélations item-total corrigées révèlent la bonne cohérence interne de la MACg. Une mesure de l’adhésion à la culture de gang présente de nombreuses utilités. Elle contribue, d’une part, aux efforts de résolution des problèmes conceptuels et méthodologiques auxquels se heurte l’étude de l’influence des gangs sur les conduites délinquantes. D’autre part, elle peut servir l’amélioration des pratiques d’évaluation des contrevenants identifiés comme membres de gang.
Zinc finger protein Zfp335 is required for the formation of the naïve T cell compartment
Authors: Han Brenda Y , Wu Shuang , Foo Chuan-Sheng , Horton Robert M , Jenne Craig N , Watson Susan R , Whittle Belinda , Goodnow Chris C , Cyster Jason G
Published: October 2014

The generation of naïve T lymphocytes is critical for immune function yet the mechanisms governing their maturation remain incompletely understood. We have identified a mouse mutant, bloto, that harbors a hypomorphic mutation in the zinc finger protein Zfp335. Zfp335bloto/bloto mice exhibit a naïve T cell deficiency due to an intrinsic developmental defect that begins to manifest in the thymus and continues into the periphery, affecting T cells that have recently undergone thymic egress. The effects of Zfp335bloto are multigenic and cannot be attributed to altered thymic selection, proliferation or Bcl2-dependent survival. Zfp335 binds to promoter regions via a consensus motif, and its target genes are enriched in categories related to protein metabolism, mitochondrial function, and transcriptional regulation. Restoring the expression of one target, Ankle2, partially rescues T cell maturation. These findings identify Zfp335 as a transcription factor and essential regulator of late-stage intrathymic and post-thymic T cell maturation.
Global albedo change and radiative cooling from anthropogenic land cover change, 1700 to 2005 based on MODIS, land use harmonization, radiative kernels, and reanalysis
Authors: Ghimire Bardan , Williams Christopher A. , Masek Jeffrey , Gao Feng , Wang Zhuosen , Schaaf Crystal , He Tao
Published: October 2014

Widespread anthropogenic land cover change over the last five centuries has influenced the global climate system through both biogeochemical and biophysical processes. Models indicate that warming from carbon emissions associated with land cover conversion has been partially offset by cooling from elevated albedo, but considerable uncertainty remains partly because of uncertainty in model treatments of albedo. This study incorporates a new spatially and temporally explicit, land cover specific albedo product derived from Moderate Resolution Imaging Spectroradiometer with a historical land use data set (Land Use Harmonization product) to provide more precise, observationally derived estimates of albedo impacts from anthropogenic land cover change with a complete range of data set specific uncertainty. The mean annual global albedo increase due to land cover change during 1700–2005 was estimated as 0.00106 ± 0.00008 (mean ± standard deviation), mainly driven by snow exposure due to land cover transitions from natural vegetation to agriculture. This translates to a top‐of‐atmosphere radiative cooling of −0.15 ± 0.1 W m−2 (mean ± standard deviation). Our estimate was in the middle of the Intergovernmental Panel on Climate Change Fifth Assessment Report range of −0.05 to −0.25 W m−2 and incorporates variability in albedo within land cover classes.
First observation of the anomalous electric field in the topside ionosphere by ionospheric modification over EISCAT
Authors: Kosch M. J. , Vickers H. , Ogawa Y. , Senior A. , Blagoveshchenskaya N.
Published: October 2014

We have developed an active ground‐based technique to estimate the steady state field‐aligned anomalous electric field (E*) in the topside ionosphere, up to ~600 km, using the European Incoherent Scatter (EISCAT) ionospheric modification facility and UHF incoherent scatter radar. When pumping the ionosphere with high‐power high‐frequency radio waves, the F region electron temperature is significantly raised, increasing the plasma pressure gradient in the topside ionosphere, resulting in ion upflow along the magnetic field line. We estimate E* using a modified ion momentum equation and the Mass Spectrometer Incoherent Scatter model. From an experiment on 23 October 2013, E* points downward with an average amplitude of ~1.6 μV/m, becoming weaker at higher altitudes. The mechanism for anomalous resistivity is thought to be low‐frequency ion acoustic waves generated by the pump‐induced flux of suprathermal electrons. These high‐energy electrons are produced near the pump wave reflection altitude by plasma resonance and also result in observed artificially induced optical emissions.
Abundance, distribution, and isotopic composition of particulate black carbon in the northern Gulf of Mexico
Authors: Yang Weifeng , Guo Laodong
Published: October 2014

There exists increasing evidence supporting the important role of black carbon in global carbon cycles. Particulate black carbon (PBC) is allochthonous and has distinct reactivities compared to the bulk particulate organic carbon (tot‐POC) in marine environments. However, the abundance, geochemical behavior of PBC and its importance in oceanic carbon budget remain poorly understood. Here we report the abundance, distribution, and stable isotopic signatures of BC derived from the chemo‐thermal oxidation (CTO‐375) method (BCCTO) in the Gulf of Mexico. Our results show that BCCTO abundance decreased from shelf to basin, and more than a half of riverine BCCTO could be removed over the shelf. Moreover, BCCTO is much more refractory compared to the tot‐POC and has δ13C values lower than those of BC‐excluded POC. These results highlight the significance of PBC in marine carbon cycles and potentially suggest the need for a new end‐member term in quantifying POC sources in the ocean.
An integrated permeability‐depth model for Earth's crust
Authors: Kuang Xingxing , Jiao Jiu Jimmy
Published: October 2014

Permeability, which generally decreases with depth, is the most important parameter that controls fluid flow in Earth's crust. There are two categories of models that describe the permeability‐depth relationship: one category forces permeability to approach infinity at the surface, and the other category leads to too much decrease in permeability with depth. Here we present a new model that integrates and reconciles existing models thus allowing for complete description of crustal permeability from the surface and through the entire crust. Our model provides improved description of observed data and is applicable to both continental crust and oceanic crust. It can be used to obtain a better understanding of the role of fluids in crustal processes.
Magnitude of extreme heat waves in present climate and their projection in a warming world
Authors: Russo Simone , Dosio Alessandro , Graversen Rune G. , Sillmann Jana , Carrao Hugo , Dunbar Martha B. , Singleton Andrew , Montagna Paolo , Barbola Paulo , Vogt Jürgen V.
Published: October 2014

An extreme heat wave occurred in Russia in the summer of 2010. It had serious impacts on humans and natural ecosystems, it was the strongest recorded globally in recent decades and exceeded in amplitude and spatial extent the previous hottest European summer in 2003. Earlier studies have not succeeded in comparing the magnitude of heat waves across continents and in time. This study introduces a new Heat Wave Magnitude Index that can be compared over space and time. The index is based on the analysis of daily maximum temperature in order to classify the strongest heat waves that occurred worldwide during the three study periods 1980–1990, 1991–2001, and 2002–2012. In addition, multimodel ensemble outputs from the Coupled Model Intercomparison Project Phase 5 are used to project future occurrence and severity of heat waves, under different Representative Concentration Pathways, adopted by the Intergovernmental Panel on Climate Change for its Fifth Assessment Report (AR5). Results show that the percentage of global area affected by heat waves has increased in recent decades. Moreover, model predictions reveal an increase in the probability of occurrence of extreme and very extreme heat waves in the coming years, in particular, by the end of this century, under the most severe IPCC AR5 scenario, events of the same severity as that in Russia in the summer of 2010 will become the norm and are projected to occur as often as every 2 years for regions such as southern Europe, North America, South America, Africa, and Indonesia.
Termination 1 timing in radiocarbon‐dated regional benthic δ18O stacks
Authors: Stern Joseph V. , Lisiecki Lorraine E.
Published: October 2014

Benthic δ18O changes are often assumed to be globally synchronous, but studies comparing 2–9 radiocarbon‐dated records over the most recent deglaciation (Termination 1) have proposed differences in the timing of benthic δ18O change between the Atlantic and Pacific, intermediate and deep, and North and South Atlantic. Because of the relatively small number of records used in these previous studies, it has remained unclear whether these differences are local or regional in scale. Here we present seven regional benthic δ18O stacks for 0–40 kyr B.P. that include 252 records with independent regional age models constrained by 852 planktonic foraminiferal 14C dates from 61 of these cores. We find a 4000 year difference between the earliest termination onset in the intermediate South Atlantic at 18.5 (95% confidence interval: 17.9–19.0) kyr B.P. and the latest in the deep Indian at 14.5 (14.1–15.0) kyr B.P. The termination onset occurs at 17.5 kyr B.P. in the intermediate and deep North Atlantic, deep South Atlantic, and deep Pacific. However, throughout the termination deep North Atlantic benthic δ18O leads the deep Pacific by an average of 1000 year and a maximum of 1700 year. Additionally, the intermediate Pacific termination onset at 16.5 (16.1–16.9) kyr B.P. demonstrates that intermediate‐depth benthic δ18O change was not globally synchronous. These regional stacks provide better age models than a global stack across Termination 1 and potentially important constraints on deglacial ocean circulation changes.
Estimating the vector electric field using monostatic, multibeam incoherent scatter radar measurements
Authors: Nicolls Michael J. , Cosgrove Russell , Bahcivan Hasan
Published: October 2014

An algorithm has been developed to image the local structure in the convection electric field using multibeam incoherent scatter radar (ISR) data. The imaged region covers about 4° in magnetic latitude and 8° in magnetic longitude for the specific geometry considered (that of the Poker Flat ISR). The algorithm implements the Lagrange method of undetermined multipliers to regularize the underdetermined problem posed by the radar measurements. The error on the reconstructed image is estimated by mapping the mathematical form to a Bayesian estimate and observing that the Lagrangian method determines an effective a priori covariance matrix from a user‐defined regularization metric. There exists a unique solution when the average measurement error is smaller than the average measurement amplitude. The algorithm is tested using synthetic and real data and appears surprisingly robust at estimating the divergence of the field. Future applications include imaging the current systems surrounding auroral arcs in order to distinguish physical mechanisms.
Technology of Active Shock Absorbers and Benefits in Regards of Ride and Handling
Authors: Schürr Heinrich , Kutsche Thomas , Maurischat Christian
Published: October 2014

Since the 1980s, there has been ongoing development of the so‐called active shock absorbers and the performance is always compared to conventional dampers, which generate damping power by holes with consistent diameters and valves with constant settings. To make active dampers work, it is necessary to change the diameters of the holes or the valve settings during operation in the car.

The positive effects of active dampers are demonstrated in this chapter, as well as the different designs of those dampers being shown in the figures. These figures also explain the historical development of active damping.

Active damping needs sensors and an ECU, as the damper characteristic must be changed dynamically according to the driving situation. A short explanation is given to see the signal exchange with other systems in the car. The used control strategies are Skyhook, Groundhook, and H‐infinity control. Today, mostly Skyhook is used for practical application. This working principle is discussed more in detail.

Real test drives show the benefits of the active dampers. It is possible to improve driving safety and driving comfort as well as driving dynamics.

The given technological outlook is mainly driven by cost reasons, as the cars of the future may be smaller cars only with lower demands in technology and performance.
Permanent Magnet Machines for Traction Applications
Authors: Zhu Z.Q.
Published: October 2014

This chapter overviews various permanent magnet (PM) brushless machines for traction applications. PM brushless DC and AC machines and drives are firstly compared in terms of constant torque and constant power capabilities, and their controllability. Various stator winding configurations, rotor topologies, and basic and novel machine topologies, including fractional slot PM, stator PM, and variable flux PM machines, as well as their features are highlighted. Then, alternate methods for enhancing the PM excitation torque and reluctance torque components, and thereby improving the torque and power capability, are described, together with methods for reducing the torque ripples and improving the overload, flux weakening, fault‐tolerant, and demagnetization withstand capabilities.
Critical Engine Layout Dimensions
Authors: Jenckes Charles H.
Published: October 2014

A critical layout dimension is an engine parameter, which characterizes an aspect of an engine. Examples of critical layout dimension are: displacement, cylinder bore diameter, stroke, number of cylinders, connecting rod length, and deck height. Many factors drive the critical layout dimensions of an engine. The art of engine design is balancing the tradeoffs to meet the technical goals for the engine. This chapter discusses these critical layout dimensions.
Transmission and Driveline: Introduction
Authors: Vaughan Nicholas
Published: October 2014

This chapter provides background information for the section of the Encyclopedia describing the transmission and driveline components within a powertrain system. This chapter also includes cross references where possible to other chapters or parts within the Encyclopedia to help the reader in understanding the overall structure and place this part in context. The principal features of the main transmission types are described and their relative importance in the global marketplace discussed. These transmission types are placed in a historical context by identifying their origins, which in most cases go back to the earliest days of motoring. There are also references made to the potential development of these transmissions with future manufacturing trends. There is a larger section devoted to the dual clutch transmission, as it was not possible to include a chapter specific to this transmission type. Finally, the logic of the organization and structure of the remaining chapters within this part of the Encyclopedia are described with cross‐referencing where appropriate.
Manual Transmissions
Authors: Krüttgen Rolf , Kunze Christian , Geis‐Drescher Wolfgang , Paluch Arnold
Published: October 2014

Manual transmission systems will remain most popular in many global key markets through the forecast period to 2020. Market share of manual transmission are currently at around 50% and is expected to remain in that region through 2020. Manual transmission is characterized by low manufacturing cost, low integration effort without any required specific calibration and deliver by appropriate usage long term durability. This section focus on principle design features, performance criteria like NVH and shift comfort and provides a short explanation about transmission assembly and testing.
Split‐Path Transmissions
Authors: Vaughan Nicholas
Published: October 2014

The topic of split‐path transmissions, by whatever name, has been well established in some mobile vehicle sectors and has more recently spread into the automobile and light vehicle segments. This chapter describes the concepts and potential advantages of using a continuously variable transmission system with more than one path between input and output. The basic concept is introduced and the simplest configurations to split the power flow are discussed. There is a detailed review of the analysis of the simple epicyclic gear in the form that is most amenable for split‐path analysis. This leads into an analysis and presentation of the main characteristics of split‐path transmissions using a single epicyclic gear. The most advantageous regions of operation are identified and representative implementations in the automobile sector using different variators are described. Attention is drawn to possible component speed and torque limits and the inclusion of some allowance for variator efficiency. The extension of the technique to the use of more than one epicyclic gear is introduced, and the difference in characteristics from a single epicyclic is identified. Reference is made to some implementations of these configurations, including multimode systems.
Coupling Connections and Splines
Authors: Hahn Steven
Published: October 2014

Coupling connections and splines have been in use even before the industrial revolution. In this chapter, it is highlighted in driveshaft applications that are common connections with flanges and splines in automotive applications. A coupling is a device used to connect two shafts together at their ends for the purpose of transmitting power. Couplings discussed here do not allow disconnection of shafts during operation. Splines are ridges or teeth on a driveshaft that mesh with grooves in a mating piece and transfer torque to it, maintaining the angular correspondence between them. The transmission of mechanical power between the two components from an input drive to a driven output are discussed and reviewed.
Semiconductor Sensors (2): Sensors for Safety Systems
Authors: Kanda Shoji
Published: October 2014

Key automotive safety systems include airbag systems, which help protect the driver and passengers in a crash, and chassis control systems, which help reduce the likelihood of an accident. The operation of both types of systems depends on the detection of inertia‐related phenomena such as impacts and side slip. The physical quantities relevant to these phenomena are detected using inertia sensors.

Airbag systems operate in combination with the seatbelts to help reduce the number of traffic accident fatalities. In these systems, the key role of detecting collisions is performed by semiconductor acceleration sensors. The latest systems have 10 acceleration sensors, 2 at the front of the vehicle, 6 at the sides, and 2 in the airbag ECU.

Chassis control systems include antilock brake systems (ABS), electronic stability control (ESC), traction control systems (TCS), and the like. The aim of these systems is to help reduce the likelihood of an accident by stabilizing vehicle behavior in unexpected situations. Each control system detects vehicle behavior using multiple acceleration sensors and yaw‐rate sensors.

This chapter describes the principles and structure of acceleration and yaw‐rate sensors as examples of semiconductor inertia sensors. It also details how such sensors are used in automotive safety systems. As both types of sensors are used in chassis control systems, the principles and structure of the sensors are described first, followed by application examples of both sensors in safety systems.
Generators and Charging Control
Authors: Asada Tadatoshi
Published: October 2014

Generators consist of alternators and regulators and function to charge the battery and to supply power to electrical loads such as the lamps and air conditioners. Alternators are driven by a belt from the engine and supply the required power by transforming mechanical into electrical energy. If the alternator power supply is less than the demand, extra power is drawn temporarily from the battery. However, in normal driving conditions, the alternator recharges the battery to a normal state. In addition, the generated voltage constantly fluctuates due to the driving conditions. For this reason, the regulator suppresses the voltage generated by the alternator and functions to supply the appropriate power to each item of electrical equipment and to charge the battery as required. Recently, the aim of charging control systems has been to improve fuel consumption by adjusting the generated voltage in accordance with the driving conditions, state of electrical load, and battery status. This fuel consumption improvement is achieved by suppressing generation during acceleration and increasing regeneration during deceleration.
Asymmetric Michael Addition of 5 H‐Oxazol‐4‐ones to Vinyl Sulfones: Stereoselective Synthesis of Monofluorinated Analogs of 2‐Tertiary Hydroxyl‐3‐Methyl‐Substituted Carboxylic Acidl Derivatives
Authors: Liu Qian , Qiao Baokun , Chin Kek Foo , Tan Choon‐Hong , Jiang Zhiyong
Published: October 2014

An asymmetric Michael addition of 5H‐oxazol‐4‐ones to vinyl sulfones has been developed. In the presence of 10 mol % of quinine‐based benzyl‐substituted thiourea as catalyst at 0 °C, the products could be obtained with excellent enantio‐ and diastereoselectivity (up to>99 % ee and>20:1 dr). 1.0 mol % of catalyst also produced the corresponding adducts with similar stereoselective results when the temperature was increased to 25 °C. The obtained adducts have been demonstrated as significant synthetic fragments to conveniently access the monofluorinated analogs of biologically important 2‐tertiary hydroxyl‐3‐methyl‐substituted carboxylic acid derivatives.

magnified image
Function and disability in children with Costello syndrome and Cardiofaciocutaneous syndrome
Authors: Johnson Barbara , Goldberg‐Strassler Dina , Gripp Karen , Thacker Mihr , Leoni Chiara , Stevenson David
Published: October 2014

There is limited research on function in individuals with RASopathies. Our hypothesis was that there was function and disability differences between Costello syndrome (CS) and Cardiofaciocutaneous syndrome (CFCS). The purpose of this study was to describe and compare the functional performance and level of disability of children with CS and CFCS using the Pediatric Outcomes Data Collection Instrument (PODCI) and Pediatric Evaluation of Disability Index (PEDI). Parents of individuals with a medical diagnosis of CS and CFCS completed the computer or paper version of the questionnaires. Comparisons of response data were made between the two syndromes and published normative data. Fifty‐two parents participated in the study, 38 in the CS group and 14 in the CFCS group. There were no significant differences in PODCI or PEDI scores between the CS and CFCS groups. There were statistically significant differences from normative values for all PODCI domains (P ≤ 0.012). The PEDI T‐scores of both groups were greater than two standard deviations below normative scores in mobility (CS = 12.37, CFCS = 2.37), social (CS = 24.01, CFCS = 20.08), and activity (CS = 15.88, CFCS = 14.32). Responsibility T scores were in the normal range (30–70) for the CS group (31.38), but not for the CFCS group (28.40). The CS and CFCS groups had activity limitations in the PODCI domains of upper extremity function, transfers, and mobility, sport and physical function. These functional limitations cause significant disability in the PEDI domains of daily activity, mobility, and socialization and cognition. CS and CFCS are similar conditions in respect to functional limitations and severity of disability. © 2014 Wiley Periodicals, Inc.
Oxidative Metalation as a Route to Size‐Mismatched Macrocyclic Complexes: Osmium Corroles
Authors: Alemayehu Abraham B. , Gagnon Kevin J. , Terner James , Ghosh Abhik
Published: October 2014

Heavy‐element corroles are of great interest as optical sensors, near‐IR dyes, phosphors, organic light‐emitting diodes, and anticancer compounds. Insertion of 5d metals into corroles, however, is often a difficult and unpredictable process. Against this backdrop, oxidative metalation of meso triarylcorroles with [Os3(CO)12]/NaN3 in refluxing 1:2 diethylene glycol monomethyl ether/glycol has provided a convenient and relatively high‐yielding route to nitridoosmium(VI) corroles, three of which could be characterized with single‐crystal X‐ray structure analysis.
Kaskadenreaktionen in der Totalsynthese von Akuammilin‐Alkaloiden
Authors: Smith Joel M. , Moreno Jesus , Boal Ben W. , Garg Neil K.
Published: October 2014

Die Akuammilin‐Alkaloide bilden eine Klasse faszinierender Naturstoffe, die vielfach Beachtung gefunden haben. Obwohl viele Akuammiline schon vor über 50 Jahren entdeckt wurden, ist es erst vor kurzem gelungen, diese Strukturen zu synthetisieren. Dieser Kurzaufsatz gibt einen Überblick über die Geschichte der Akuammilin‐Alkaloide, einschließlich ihrer Isolierung, Strukturaufklärung, biologischen Aktivität und vorgeschlagenen Biosynthesen. Darüber hinaus werden kürzlich abgeschlossene Totalsynthesen vorgestellt. Diese Beispiele veranschaulichen nicht nur die Leistungsfähigkeit der Totalsynthese zum Aufbau von Alkaloiden, sie zeigen außerdem, wie die Molekülgerüste der Akuammiline die Entdeckung und Realisierung von innovativen Kaskadenreaktionen zum schnellen Aufbau komplexer Strukturen angeregt haben.
Metal‐Free Enantioselective Electrophilic Activation of Allenamides: Stereoselective Dearomatization of Indoles
Authors: Romano Ciro , Jia Minqiang , Monari Magda , Manoni Elisabetta , Bandini Marco
Published: October 2014

The effective and unprecedented chiral BINOL phosphoric acid catalyzed (1–10 mol %) dearomatization of indoles through electrophilic activation of allenamides (ee up to 94 %), is documented. Besides the synthesis of 3,3‐disubstituted indolenine cores, a dearomatization/hydrogen transfer cascade sequence is also presented as a new synthetic shortcut toward highly enantiomerically enriched indolines.
Synthese, Struktur und Frequenzverdopplungseffekt von Calciumcyanurat
Authors: Kalmutzki Markus , Ströbele Markus , Wackenhut Frank , Meixner Alfred J. , Meyer H.‐Jürgen
Published: October 2014

Calciumcyanurat entsteht bei der Festkörpermetathesereaktion von Calciumchlorid mit Kaliumcyanat. Die Bildung der neuen Verbindung Ca3(O3C3N3)2 (CCY), die unter Cyclotrimerisierung von Cyanat‐Ionen erfolgt, wurde thermoanalytisch untersucht und die Kristallstruktur mittels Einkristallstrukturanalyse bestimmt. Die Struktur von CCY ist eng mit der Struktur des bekannten Oxoborats β‐BaB2O4 (BBO) verwandt. SHG‐Messungen an Kristallpulvern zeigen für CCY eine um ca. eine Größenordnung höhere SHG‐Effizienz als für BBO.
Elektronischer Energietransfer über lange Distanzen in lichtsammelnden supramolekularen Polymeren
Authors: Winiger Christian B. , Li Shaoguang , Kumar Ganesh R. , Langenegger Simon M. , Häner Robert
Published: October 2014

Das effiziente Sammeln von Sonnenenergie beruht auf dem Design und der Entwicklung von präzise strukturierten lichtabsorbierenden Systemen. Wir beschreiben hier, dass supramolekulare, mit Pyren dotierte Phenanthrenpolymere effiziente Kollektoren von Lichtenergie sind. Die linearen Polymere bilden sich durch geordnetes Zusammenfügen kurzer, amphiphiler Oligomere in wässrigem Medium. Lichtenergie wird von Phenanthrenbausteinen absorbiert und über lange Distanzen (>100 nm) entlang der Polymere zu den Pyren‐Akzeptormolekülen transportiert. Die hohen Fluoreszenzquantenausbeuten belegen einen effizienten Energietransfer und lassen auf einen quantenkohärenten Mechanismus schließen.
Hydroboration of Arynes with N‐Heterocyclic Carbene Boranes
Authors: Taniguchi Tsuyoshi , Curran Dennis P.
Published: October 2014

Arynes were generated in situ from ortho‐silyl aryl triflates and fluoride ions in the presence of stable N‐heterocyclic carbene boranes (NHCBH3). Spontaneous hydroboration ensued to provide stable B‐aryl‐substituted NHC‐boranes (NHCBH2Ar). The reaction shows good scope in terms of both the NHC‐borane and aryne components and provides direct access to mono‐ and disubstituted NHC‐boranes. The formation of unusual ortho regioisomers in the hydroboration of arynes with an electron‐withdrawing group supports a hydroboration process with hydride‐transfer character.
Construction of Axial Chirality by Rhodium‐Catalyzed Asymmetric Dehydrogenative Heck Coupling of Biaryl Compounds with Alkenes
Authors: Zheng Jun , You Shu‐Li
Published: October 2014

Enantioselective construction of axially chiral biaryls by direct CH bond functionalization reactions has been realized. Novel axially chiral biaryls were synthesized by the direct CH bond olefination of biaryl compounds, using a chiral [Cp*RhIII] catalyst, in good to excellent yields and enantioselectivities. The obtained axially chiral biaryls were found as suitable ligands for rhodium‐catalyzed asymmetric conjugate additions.
Cascade Reactions: A Driving Force in Akuammiline Alkaloid Total Synthesis
Authors: Smith Joel M. , Moreno Jesus , Boal Ben W. , Garg Neil K.
Published: October 2014

The akuammiline alkaloids are a family of intricate natural products which have received considerable attention from scientists worldwide. Despite the fact that many members of this alkaloid class were discovered over 50 years ago, synthetic chemistry has been unable to address their architectures until recently. This minireview provides a brief overview of the rich history of the akuammiline alkaloids, including their isolation, structural features, biological activity, and proposed biosyntheses. Furthermore, several recently completed total syntheses are discussed in detail. These examples not only serve to highlight modern achievements in alkaloid total synthesis, but also demonstrate how the molecular scaffolds of the akuammilines have provided inspiration for the discovery and implementation of innovative cascade reactions for the rapid assembly of complex structures.
Enantioselective, Protecting‐Group‐Free Total Synthesis of Sarpagine Alkaloids—A Generalized Approach
Authors: Krüger Sebastian , Gaich Tanja
Published: October 2014

A generalized synthetic access to sarpagine alkaloids through a joint synthetic sequence has been accomplished. Its applicability is showcased by the enantioselective total syntheses of vellosimine (1), N‐methylvellosimine (3), and 10‐methoxyvellosimine (8). The synthetic sequence is concise (eight steps) from known compound 13, and requires no protecting groups. The indole heterocycle was introduced in the last step. This strategy allows access to sarpagine alkaloids through a shared synthetic route leading to precursor 10, which we term “privileged intermediate”. Starting from this intermediate, all sarpagine alkaloids can be synthesized using phenylhydrazines with different substitution patterns (15–17). Our approach brings about the advantage, that synthesis optimization only needs to be performed once for many natural products. The key features of the synthesis are a [5+2]‐cycloaddition and a ring enlargement.
Synthesis, Structure, and Frequency‐Doubling Effect of Calcium Cyanurate
Authors: Kalmutzki Markus , Ströbele Markus , Wackenhut Frank , Meixner Alfred J. , Meyer H.‐Jürgen
Published: October 2014

Calcium cyanurate is synthesized by reacting calcium chloride with potassium cyanate following a solid‐state reaction. The formation of the new compound Ca3(O3C3N3)2 (CCY), which occurs by the cyclotrimerization of cyanate ions, was examined thermoanalytically and the crystal structure was determined by single‐crystal structure analysis. The structure of CCY is closely related to the structure of the well‐known oxoborate β‐BaB2O4 (BBO). Second harmonic generation (SHG) measurements on crystal powders show a higher SHG efficiency for CCY than for BBO by about one order of magnitude.
Polyoxometalate‐Based Entangled Coordination Networks Induced by an Extended Bis(triazole) Ligand
Authors: Hao Xiu‐Li , Ma Yuan‐Yuan , Zhou Wen‐Zhe , Zang Hong‐Ying , Wang Yong‐Hui , Li Yang‐Guang
Published: October 2014

The introduction of an extended bridging bis(triazole) ligand, that is, 4,4′‐bis(1,2,4‐triazol‐1‐ ylmethyl)biphenyl (BBPTZ), into the hydrothermal reaction system containing transition metal ions and Keggin‐type polyoxometalates (POMs) led to the isolation of three new organic–inorganic hybrid entangled coordination networks, [CuI2CuII(BBPTZ)6][SiW12O40]⋅12 H2O (1), [Ni(BBPTZ)2(H2O)][H2SiW12O40]⋅11 H2O (2), and [Ni2(BBPTZ)4(H2O)2][SiW12O40]⋅3 H2O (3). All three compounds were characterized by elemental analysis, IR spectroscopy, TG analysis, powder X‐ray diffraction, and single‐crystal X‐ray diffraction. Compound 1 contains a 2‐D POM‐based metal–organic layer entangled with 1‐D ladder‐like metal–organic chains. The adjacent 2‐D networks are parallel to each other, further stacking into a 3‐D supramolecular framework with 1‐D channels. Compound 2 exhibits a 1‐D cantilever‐type loop‐containing chain. The Keggin‐type POMs act as the cantilever groups, leading to the adjacent catilever‐type chains interwaving together to form a 3‐D supramolecular open framework with two types of channels. Compound 3 possesses a 3‐D open framework based on 2‐D metal–organic undulated layer and Keggin‐type POM clusters. Three sets of such frameworks further interpenetrate with each other to form an interesting three‐fold interpenetrating framework. The photocatalytic activities of compounds 1–3 for the decomposition of methylene blue (MB) under UV light have been investigated.
An FITC‐BODIPY FRET Couple: Application to Selective, Ratiometric Detection and Bioimaging of Cysteine
Authors: Ma Dong Hee , Kim Dokyoung , Akisawa Takuya , Lee Kyung‐Ha , Kim Kyong‐Tai , Ahn Kyo Han
Published: October 2014

A novel FRET couple of fluorescein is disclosed, and it was readily constructed by conjugating an amino‐BODIPY dye, a new FRET donor, with fluorescein isocyanate. Its potential was demonstrated by a fluorescence sensing system for cysteine, which was prepared by introducing acryloyl groups to the fluorescein moiety. The FRET probe exhibited promising ratiometric response to cysteine with high selectivity and sensitivity in a buffer solution containing acetonitrile at a physiological pH of 7.4, but showed slow reactivity. This slow response was solved by addition of a surfactant, thus allowing ratiometric imaging and determination of the endogenous level of cysteine in cells in HEPES buffer, by confocal fluorescence microscopy. Imaging experiments toward various cells suggested that such aryl acrylate type probes are vulnerable to the ubiquitous esterase activity. For the selected C6 cell line, in which the esterase activity was minimal, the ratiometric quantification of cysteine level was demonstrated. The FRET probe was also applied to determine the level of cysteine in human blood plasma.
A Systematic Literature Review of Emotion Regulation Measurement in Individuals With Autism Spectrum Disorder
Authors: Weiss Jonathan A. , Thomson Kendra , Chan Lisa
Published: October 2014

Emotion regulation (ER) difficulties are a potential common factor underlying the presentation of multiple emotional and behavioral problems in individuals with Autism Spectrum Disorder (ASD). To provide an overview of how ER has been studied in individuals with ASD, we conducted a systematic review of the past 20 years of ER research in the ASD population, using established keywords from the most comprehensive ER literature review of the typically developing population to date. Out of an initial sampling of 305 studies, 32 were eligible for review. We examined the types of methods (self‐report, informant report, naturalistic observation/ behavior coding, physiological, and open‐ended) and the ER constructs based on Gross and Thompson's modal model (situation selection, situation modification, attention deployment, cognitive change, and response modulation). Studies most often assessed ER using one type of method and from a unidimensional perspective. Across the 32 studies, we documented the types of measures used and found that 38% of studies used self‐report, 44% included an informant report measure, 31% included at least one naturalistic observation/behavior coding measure, 13% included at least one physiological measure, and 13% included at least one open‐ended measure. Only 25% of studies used more than one method of measurement. The findings of the current review provide the field with an in‐depth analysis of various ER measures and how each measure taps into an ER framework. Future research can use this model to examine ER in a multicomponent way and through multiple methods. Autism Res 2014, 7: 629–648. © 2014 The Authors. Autism Research published by Wiley Periodicals, Inc. on behalf of International Society for Autism Research
Identifying (non‐)coding RNAs and small peptides: Challenges and opportunities
Authors: Pauli Andrea , Valen Eivind , Schier Alexander F.
Published: October 2014

Over the past decade, high‐throughput studies have identified many novel transcripts. While their existence is undisputed, their coding potential and functionality have remained controversial. Recent computational approaches guided by ribosome profiling have indicated that translation is far more pervasive than anticipated and takes place on many transcripts previously assumed to be non‐coding. Some of these newly discovered translated transcripts encode short, functional proteins that had been missed in prior screens. Other transcripts are translated, but it might be the process of translation rather than the resulting peptides that serves a function. Here, we review annotation studies in zebrafish to discuss the challenges of placing RNAs onto the continuum that ranges from functional protein‐encoding mRNAs to potentially non‐functional peptide‐producing RNAs to non‐coding RNAs. As highlighted by the discovery of the novel signaling peptide Apela/ELABELA/Toddler, accurate annotations can give rise to exciting opportunities to identify the functions of previously uncharacterized transcripts.
Determination of ethanol using permanganate–CdS quantum dot chemiluminescence system
Authors: Abolhasani Jafar , Hassanzadeh Javad
Published: October 2014

A novel and highly sensitive chemiluminescence (CL) method for the determination of ethanol was developed based on the CdS quantum dots (QDs)–permanganate system. It was found that KMnO4 could directly oxidize CdS QDs in acidic media resulting in relatively high CL emission. A possible mechanism was proposed for this reaction based on UV/Vis absorption, fluorescence and the generated CL emission spectra. However, it was observed that ethanol had a remarkable inhibition effect on this system. This effect was exploited in the determination of ethanol within the concentration range 12–300 µg/L, with detection at 4.3 µg/L. In order to evaluate the capability of presented method, it was satisfactorily utilized in the determination of alcohol in real samples. Copyright © 2014 John Wiley & Sons, Ltd.
Direct Synthesis of Partially Modified 2′‐O‐Pivaloyloxymethyl RNAs by a Base‐Labile Protecting Group Strategy and their Potential for Prodrug‐Based Gene‐Silencing Applications
Authors: Biscans Annabelle , Bos Maxence , Martin Anthony R. , Ader Nicholas , Sczakiel Georg , Vasseur Jean‐Jacques , Dupouy Christelle , Debart Françoise
Published: October 2014

An original and straightforward synthesis of partially modified 2′‐O‐pivaloyloxymethyl‐substituted (PivOM‐substituted) oligoribonucleotides has been achieved. The aim of this 2′‐enzymolabile modification was to enhance nuclease stability of RNA and transmembrane transport. To make these modified RNAs easily available we developed a base‐labile protecting group strategy with standard protections for nucleobases (acyl) and phosphates (cyanoethyl), a Q‐linker and two different acetalester protection groups for 2′‐OH: propionyloxymethyl (PrOM) and PivOM. Interestingly, orthogonal deprotection conditions based on anhydrous butylamine in THF were found to remove propionyloxymethyl groups selectively, while preserving PivOM groups. Duplex stability, circular dichroism studies and nuclease resistance, as well as the ability to inhibit gene expression of modified 2′‐O‐PivOM RNA, were evaluated.
Engineered Pt‐Doped Nanoceria for Oxidase‐Based Bioelectrodes Operating in Oxygen‐Deficient Environments
Authors: Sardesai Naimish P. , Karimi Anahita , Andreescu Silvana
Published: October 2014

The use of Pt‐doped nanoceria as a new catalytic amplification system for first‐generation electrochemical oxidase‐based biosensors is described. The catalytic activity and oxygen‐rich surface of nanoceria, combined with the high conductivity of noble‐metal Pt electrocatalysts, provide enhanced performance characteristics of mediatorless glucose oxidase biosensors for the detection of glucose in oxygen‐deficient environments. The Pt‐doped nanoceria particles act as both an internal oxygen reservoir to satisfy the oxygen requirement for the enzymatic reaction and a catalytic amplification system for the detection of enzymatically generated H2O2. The biosensor allows detection of glucose in anaerobic conditions with a detection limit of 37.4 μM. The proposed strategy can be widely applicable to other oxidase‐based biosensors that require measurements of their substrates in oxygen‐deficient conditions.
The Mtr Pathway of Shewanella oneidensis MR‐1 Couples Substrate Utilization to Current Production in Escherichia coli
Authors: TerAvest Michaela A. , Zajdel Tom J. , Ajo‐Franklin Caroline M.
Published: October 2014

The front cover artwork is provided by the group of Dr. Caroline Ajo‐Franklin at Berkeley Lab, USA. The cover image shows electrogenic E. coli transporting electrical energy, originating from its metabolism, to external metals. Read the full text of the article at 10.1002/celc.201402194.
Coumarin‐3‐Aldehyde as a Scaffold for the Design of Tunable PET‐Modulated Fluorescent Sensors for Neurotransmitters
Authors: Hettie Kenneth S. , Glass Timothy E.
Published: October 2014

NeuroSensor 521 (NS521) is a fluorescent sensor for primary‐amine neurotransmitters based on a platform that consists of an aryl moiety appended to position C4 of the coumarin‐3‐aldehyde scaffold. We demonstrate that sensors based on this platform behave as a directly linked donor–acceptor system that operates through an intramolecular acceptor‐excited photoinduced electron transfer (a‐PET) mechanism. To evaluate the PET process, a series of benzene‐ and thiophene‐substituted derivatives were prepared and the photophysical properties, binding affinities, and fluorescence responses toward glutamate, norepinephrine, and dopamine were determined. The calculated energy of the highest occupied molecular orbital (EHOMO) of the pendant aryl substituents, along with oxidation and reduction potential values derived from the calculated molecular orbital energy values of the platform components, allowed for calculation of the fluorescence properties of the benzene sensor series. Interestingly, the thiophene derivatives did not fit the typical PET model, highlighting the limitations of the method. A new sensor, NeuroSensor 539, displayed enhanced photophysical properties aptly suited for biological imaging. NeuroSensor 539 was validated by selectively labeling and imaging norepinephrine in secretory vesicles of live chromaffin cells.
Excimer Formation in a Confined Space: Photophysics of Ladderphanes with Tetraarylethylene Linkers
Authors: Chen Chih‐Hsien , Satyanarayana Kamani , Liu Yi‐Hung , Huang Shou‐Ling , Lim Tsong‐Shin , Luh Tien‐Yau
Published: October 2014

Communication between chromophores is vital for both natural and non‐natural photophysical processes. Spatial confinements offer unique conditions to scrutinize such interactions. Polynorbornene‐ and polycyclobutene‐based ladderphanes are ideal model compounds in which all tetraarylethylene (TAE) linkers are aligned coherently. The spans for each of the monomeric units in these ladderphanes are 4.5–5.5 Å. Monomers do not exhibit emission, because bond rotation in TAE can quench the excited‐state energy. However, polymers emit at 493 nm (Φ=0.015) with large Stokes shift under ambient conditions and exhibit dual emission at 450 and 493 nm at 150 K. When the temperature is lowered, the emission intensity at 450 nm increases, whereas that at 493 nm decreases. At 100 K, both monomers and polymers emit only at 450 nm. This shorter‐wavelength emission arises from the intrinsic emission of TAE chromophore, and the emission at 493 nm could be attributed to the excimer emission in the confined space of ladderphanes. The fast kinetics suggest diffusion‐controlled formation of the excimer.
Bispidines for Dual Imaging
Authors: Stephan Holger , Walther Martin , Fähnemann Silke , Ceroni Paola , Molloy Jennifer K. , Bergamini Giacomo , Heisig Fabian , Müller Christa E. , Kraus Werner , Comba Peter
Published: October 2014

The efficient transformation of the hexadentate bispidinol 1 into carbamate derivatives yields functional bispidines enabling convenient functionalization for targeted imaging. The BODIPY‐substituted bispidine 3 combines a coordination site for metal ions, such as radioactive 64CuII, with a fluorescent unit. Product 3 was thoroughly characterized by standard analytical methods, single crystal X‐ray diffraction, radiolabeling, and photophysical analysis. The luminescence of ligand 3 was found to be strongly dependent on metal ion coordination: CuII quenches the BODIPY fluorescence, whereas NiII and ZnII ions do not affect it. It follows that, in imaging applications with the positron emitter 64CuII, residues of its origin from enriched 64Ni and the decay products 64NiII and 64ZnII, efficiently restore the fluorescence of the ligand. This allows for monitoring of the emitted radiation as well as the fluorescence signal. The stability of the 64CuII3 complex is investigated by transmetalation experiments with ZnII and NiII, using fluorescence and radioactivity detection, and the results confirm the high stability of 64CuII3. In addition, metal complexes of ligand 3 with the lanthanide ions TbIII, EuIII, and NdIII are shown to exhibit emission of the BODIPY ligand and the lanthanide ion, thus enabling dual emission detection.