bluuebunny/crossref_metadata_2025 huggingface dataset:
Source characteristics of the 2015 Mw6.5 Lefkada, Greece, strike‐slip earthquake
Authors: Melgar Diego , Ganas Athanassios , Geng Jianghui , Liang Cunren , Fielding Eric J. , Kassaras Ioannis
Published: March 2017

We present a kinematic slip model from the inversion of 1 Hz GPS, strong motion, and interferometric synthetic aperture radar (InSAR) data for the 2015 Mw6.5 Lefkada, Greece, earthquake. We will show that most of the slip during this event is updip of the hypocenter (10.7 km depth) with substantial slip (>0.5 m) between 5 km depth and the surface. The peak slip is ~1.6 m, and the inverted rake angles show predominantly strike‐slip motion. Slip concentrates mostly to the south of the hypocenter, and the source time function indicates a total duration of ~17 s with peak moment rate at ~6 s. We will show that a 65° dipping geometry is the most plausible due to a lack of polarity reversals in the InSAR data and good agreement with Coulomb stress modeling, aftershock locations, and regional moment tensors. We also note that there was an ~20 cm peak‐to‐peak tsunami observed at one tide gauge station 300 km away from the earthquake. We will discuss tsunami modeling results and study the possible source of the amplitude discrepancy between the modeled and the observed data at far‐field tide gauges.
Incorporating geologic information into hydraulic tomography: A general framework based on geostatistical approach
Authors: Zha Yuanyuan , Yeh Tian‐Chyi J. , Illman Walter A. , Onoe Hironori , Mok Chin Man W. , Wen Jet‐Chau , Huang Shao‐Yang , Wang Wenke
Published: March 2017

Hydraulic tomography (HT) has become a mature aquifer test technology over the last two decades. It collects nonredundant information of aquifer heterogeneity by sequentially stressing the aquifer at different wells and collecting aquifer responses at other wells during each stress. The collected information is then interpreted by inverse models. Among these models, the geostatistical approaches, built upon the Bayesian framework, first conceptualize hydraulic properties to be estimated as random fields, which are characterized by means and covariance functions. They then use the spatial statistics as prior information with the aquifer response data to estimate the spatial distribution of the hydraulic properties at a site. Since the spatial statistics describe the generic spatial structures of the geologic media at the site rather than site‐specific ones (e.g., known spatial distributions of facies, faults, or paleochannels), the estimates are often not optimal. To improve the estimates, we introduce a general statistical framework, which allows the inclusion of site‐specific spatial patterns of geologic features. Subsequently, we test this approach with synthetic numerical experiments. Results show that this approach, using conditional mean and covariance that reflect site‐specific large‐scale geologic features, indeed improves the HT estimates. Afterward, this approach is applied to HT surveys at a kilometer‐scale‐fractured granite field site with a distinct fault zone. We find that by including fault information from outcrops and boreholes for HT analysis, the estimated hydraulic properties are improved. The improved estimates subsequently lead to better prediction of flow during a different pumping test at the site.
Space‐time duality for the fractional advection‐dispersion equation
Authors: Kelly James F. , Meerschaert Mark M.
Published: March 2017

The fractional advection‐dispersion equation replaces the second spatial derivative in the usual advection‐dispersion equation with a fractional derivative in the spatial variable. It was first applied to tracer tests in underground aquifers, and later to tracer tests in rivers. An alternative model replaces the first time derivative with a fractional derivative in time. Previous work has shown that both models provide a reasonable fit to breakthrough curves in rivers, which has led to a controversy regarding the physically appropriate fractional model. This paper shows that the relevant space‐fractional model is mathematically equivalent to the corresponding time‐fractional model, thus resolving the controversy.
The mechanistic basis for storage‐dependent age distributions of water discharged from an experimental hillslope
Authors: Pangle Luke A. , Kim Minseok , Cardoso Charlene , Lora Marco , Meira Neto Antonio A. , Volkmann Till H. M. , Wang Yadi , Troch Peter A , Harman Ciaran J.
Published: March 2017

Distributions of water transit times (TTDs), and related storage‐selection (SAS) distributions, are spatially integrated metrics of hydrological transport within landscapes. Recent works confirm that the form of TTDs and SAS distributions should be considered time variant—possibly depending, in predictable ways, on the dynamic storage of water within the landscape. We report on a 28 day periodic‐steady‐state‐tracer experiment performed on a model hillslope contained within a 1 m3 sloping lysimeter. Using experimental data, we calibrate physically based, spatially distributed flow and transport models, and use the calibrated models to generate time‐variable SAS distributions, which are subsequently compared to those directly observed from the actual experiment. The objective is to use the spatially distributed estimates of storage and flux from the model to characterize how temporal variation in water storage influences temporal variation in flow path configurations, and resulting SAS distributions. The simulated SAS distributions mimicked well the shape of observed distributions, once the model domain reflected the spatial heterogeneity of the lysimeter soil. The spatially distributed flux vectors illustrate how the magnitude and directionality of water flux changes as the water table surface rises and falls, yielding greater contributions of younger water when the water table surface rises nearer to the soil surface. The illustrated mechanism is compliant with conclusions drawn from other recent studies and supports the notion of an inverse‐storage effect, whereby the probability of younger water exiting the system increases with storage. This mechanism may be prevalent in hillslopes and headwater catchments where discharge dynamics are controlled by vertical fluctuations in the water table surface of an unconfined aquifer.
Stress field and kinematics for diffuse microseismicity in a zone of continental transpression, South Island, New Zealand
Authors: Warren‐Smith Emily , Lamb Simon , Stern Tim A.
Published: March 2017

We analyze shallow (0–20 km) microseismicity adjacent to the Alpine Fault in New Zealand, where there is oblique convergence of the Australian and Pacific plates. Focal mechanisms for 155 earthquakes (June 2012 to October 2013) are inverted to determine the orientation of the stress field. This yields a principal horizontal axis of compression, SHmax = 114° ± 10°, which cannot be explained in terms of the sum of stress from tectonic loading due to plate convergence, indicated by GPS observations, and gravitational stresses. The azimuth of slip vectors for individual focal mechanisms cluster perpendicular and parallel to the plate convergence vector. These faults, however, strike at ~45° to SHmax from the stress inversion, suggesting a very low coefficient of friction. The earthquake slip directions may be kinematically controlled, accommodating the plate convergence on a limited set of fractures, similar to the segmentation for neotectonic faulting along the Alpine Fault, which is partitioned into strike‐slip and thrust segments at a 1–10 km scale. We suggest two possible controls on our calculated SHmax azimuths. First, there may be a slight clockwise bias in the estimates of SHmax from earthquakes; slip may be occurring on a more limited range of fractures than assumed by the stress inversion method, although this effect is likely to be relatively small (±5°). More importantly, the components of the stress field may be relieved at different timescales during big earthquakes, resulting in a residual stress field that varies significantly (±15°) on timescales of several large earthquakes.
Tunneling and Superconductivity
Authors: Ruggiero Steven T.
Published: March 2017

The article contains sections titled:

Introduction

Normal/Insulator/Normal Tunnel Junctions

Normal/Insulator/Superconducting Tunnel Junctions

Superconductor/Insulator/Superconducting Tunnel Junctions

Superconducting Quantum Interference Devices (SQUIDs)

Phonon Structure

Geometrical Resonances

Scanning Tunneling Microscopy

Charging Effects
Superconducting Magnets for Fusion
Authors: Duchateau Jean‐Luc
Published: March 2017

The article contains sections titled:

Introduction to Fusion and Superconductivity

ITER

Cable in Conduit Conductors (CICC)

Quench Protection and Quench Detection in Fusion Magnets

Prospective about Future Fusion Reactors:DEMO

Conclusion
Single Cooper Pair Circuits and Quantum Metrology
Authors: Zorin Alexander B.
Published: March 2017

The article contains sections titled:

Introduction

Engineering of the Electromagnetic Environment

The Bloch Oscillations and Their Phase Locking

New Concept of the Experiment with Superconducting Nanowires

Cooper Pair Pumps and Single Quasiparticle Circuits

Metrological Aspect

Conclusion

Acknowledgement
Radiation and Particle Detectors
Authors: Grupen Claus
Published: March 2017

Particle and radiation detectors have a large number of applications in many different fields like high energy physics, astro‐particle physics, nuclear physics, medicine, biology, and even in art and other fields. The article describes the basic interaction processes for typical detectors and their applications used in many different fields. Special emphasis is put on detectors for high resolution spectroscopy. In this respect the best results are obtained with cryogenic detectors which benefit from the low energy required to achieve quantum transitions, in contrast e.g. to ionisation processes. These detection techniques are particularly important for the measurement of low energy particles and rare proceses, like the search for weakly interacting massive particles, which are used in this article as an example for the research possibilities for cryogenic detectors.
Superconducting Hot Electron Bolometers and Transition Edge Sensors
Authors: Pepe Giovanni P. , Cristiano Roberto , Gatti Flavio
Published: March 2017

The article contains sections titled:

Introduction

The Energy Scenario and Timescales

The Hot Electron Bolometer

Transition Edge Sensor

The Main Physical Parameters

Recent Achievements
Quantum Computing
Authors: Lisenfeld Jürgen
Published: March 2017

The article contains sections titled:

Introduction

Quantum Computing

Decoherence

Phase Qubits

Charge Qubits

Transmon Qubits
Digital
SQUID
s
Authors: Febvre Pascal
Published: March 2017

The article contains sections titled:

Introduction

History of Digital
SQUID
s

Recent Developments of Digital
SQUID
s

An Application of Digital
SQUID
s for Studying Natural Hazards

Prospects
Investigations on Mechanical and Tribological Behavior of dcMS/HPPMS CrN and (Cr,Al)N Hard Coatings Using Nanoscratch Technique
Authors: Bobzin Kirsten , Brögelmann Tobias , Kruppe Nathan C. , Arghavani Mostafa
Published: March 2017

In this paper, interfacial adhesion strength and tribological behavior of systems, consisting of CrN and (Cr,Al)N coatings and AISI 420 steel substrate are investigated. The coatings are deposited using a hybrid technology consisting of direct current and high power pulse magnetron sputtering dcMS/HPPMS. Conventional Rockwell and scratch tests as well as nanoscratch analyses are performed. For the nanoscratch tests, a Berkovich and a conical indenters are used. Damage mechanisms are analyzed using Scanning Electron Microscopy (SEM) and explained by the plastic work from the nanoindentation tests. Investigations show a stronger interfacial adhesion strength and a higher abrasion resistance of the system AISI 420/(Cr,Al)N compared to the AISI 420/CrN.
Nanoscale Defect Engineering and the Resulting Effects on Domain Wall Dynamics in Ferroelectric Thin Films
Authors: McGilly Leo J. , Sandu Cosmin S. , Feigl Ludwig , Damjanovic Dragan , Setter Nava
Published: March 2017

Defect engineering is one of the cornerstones of the modern electronics industry. Almost all electronic devices include materials that have been doped by ion bombardment. For materials where crystallinity is essential, such as ferroelectrics, defect type and concentration can vastly influence properties and are often used to optimize device performance. This study shows a method to effectively control the density and position on the nanoscale of defect sites in thin films of Pb(Zr,Ti)O3 via focused ion beam microscopy. This allows for exceptional clarity of observation of the role of defects in nucleation, polarization switching, and domain wall interaction through investigation with piezoresponse force microscopy and transmission electron microscopy, adding insight to accepted but seldom‐demonstrated facts on defect‐induced effects. This nanoscale defect engineering can be used as a tool to control material properties, and furthermore, a route is demonstrated toward a practical application.
Chemically Resistant, Shapeable, and Conducting Metal‐Organic Gels and Aerogels Built from Dithiooxamidato Ligand
Authors: Vallejo‐Sánchez Daniel , Amo‐Ochoa Pilar , Beobide Garikoitz , Castillo Oscar , Fröba Michael , Hoffmann Frank , Luque Antonio , Ocón Pilar , Pérez‐Yáñez Sonia
Published: March 2017

Metal‐organic gels (MOGs) appear as a blooming alternative to well‐known metal‐organic frameworks (MOFs). Porosity of MOGs has a microstructural origin and not strictly crystalline like in MOFs; therefore, gelation may provide porosity to any metal‐organic system, including those with interesting properties but without a porous crystalline structure. The easy and straightforward shaping of MOGs contrasts with the need of binders for MOFs. In this contribution, a series of MOGs based on the assembly of 1D‐coordination polymer nanofibers of formula [M(DTA)]n (MII: Ni, Cu, Pd; DTA: dithiooxamidato) are reported, in which properties such as porosity, chemical inertness, mechanical robustness, and stimuli‐responsive electrical conductivity are brought together. The strength of the MS bond confers an unusual chemical resistance, withstanding exposure to acids, alkalis, and mild oxidizing/reducing chemicals. Supercritical drying of MOGs provides ultralight metal‐organic aerogels (MOAs) with densities as low as 0.03 g cm−3 and plastic/brittle behavior depending on the nanofiber aspect ratio. Conductivity measurements reveal a semiconducting behavior (10−12 to 10−7 S cm−1 at 298 K) that can be improved by doping (10−5 S cm−1). Moreover, it must be stressed that conductivity of MOAs reversibly increases (up to 10−5 S cm−1) under the presence of acetic acid.
Fabricating Aptamer‐Conjugated PEGylated‐MoS2/Cu1.8S Theranostic Nanoplatform for Multiplexed Imaging Diagnosis and Chemo‐Photothermal Therapy of Cancer
Authors: Meng Xiangdan , Liu Zhiqiang , Cao Yu , Dai Wenhao , Zhang Kai , Dong Haifeng , Feng Xiaoyan , Zhang Xueji
Published: March 2017

Fabricating theranostic nanoparticles combining multimode disease diagnosis and therapeutic has become an emerging approach for personal nanomedicine. However, the diagnostic capability, biocompatibility, and therapeutic efficiency of theranostic nanoplatforms limit their clinic widespread applications. Targeting to the theme of accurate diagnosis and effective therapy of cancer cells, a multifunctional nanoplatform of aptamer and polyethylene glycol (PEG) conjugated MoS2 nanosheets decorated with Cu1.8S nanoparticles (ATPMC) is developed. The ATPMC nanoplatform accomplishes photoluminescence imaging, photoacoustic imaging, and photothermal imaging for in vitro and in vivo tumor cells imaging diagnosis. Meanwhile, the ATPMC nanoplatform facilitates selective delivery of gene probe to detect intracellular microRNA aberrantly expressed in cancer cells and anticancer drug doxorubicin (DOX) for chemotherapy. Moreover, the synergistic interaction of MoS2 and Cu1.8S renders the ATPMC nanoplatform with superb photothermal conversion efficiency. The ATPMC nanoplatform loaded with DOX displays near‐infrared laser‐induced programmed chemotherapy and advanced photothermal therapy, and the targeted chemo‐photothermal therapy presents excellent antitumor efficiency.
The Effect of H‐ and J‐Aggregation on the Photophysical and Photovoltaic Properties of Small Thiophene–Pyridine–DPP Molecules for Bulk‐Heterojunction Solar Cells
Authors: Más‐Montoya Miriam , Janssen René A. J.
Published: March 2017

The performance of organic semiconductors in optoelectronic devices depends on the functional properties of the individual molecules and their mutual orientations when they are in the solid state. The effect of H‐ and J‐aggregation on the photophysical properties and photovoltaic behavior of four electronically identical but structurally different thiophene–pyridine–diketopyrrolopyrrole molecules is studied. By introducing and changing the position of two hexyl side chains on the two peripheral thiophene units of these molecules, their aggregation in thin films between H‐type and J‐type is effectively tuned, as evidenced from the characteristics of optical absorption, fluorescence, and excited state lifetime. The two derivatives that assemble into J‐type aggregates exhibit a significantly enhanced photovoltaic performance, up to an order of magnitude, compared to the two molecules that form H‐type aggregates. The reasons for this remarkably different behavior are discussed.
808‐nm‐Light‐Excited Lanthanide‐Doped Nanoparticles: Rational Design, Luminescence Control and Theranostic Applications
Authors: Liu Bei , Li Chunxia , Yang Piaoping , Hou Zhiyao , Lin Jun
Published: March 2017

808 nm‐light‐excited lanthanide (Ln3+)‐doped nanoparticles (LnNPs) hold great promise for a wide range of applications, including bioimaging diagnosis and anticancer therapy. This is due to their unique properties, including their minimized overheating effect, improved penetration depth, relatively high quantum yields, and other common features of LnNPs. In this review, the progress of 808 nm‐excited LnNPs is reported, including their i) luminescence mechanism, ii) luminescence enhancement, iii) color tuning, iv) diagnostic and v) therapeutic applications. Finally, the future outlook and challenges of 808 nm‐excited LnNPs are presented.
Atomic Defects in Two‐Dimensional Materials: From Single‐Atom Spectroscopy to Functionalities in Opto‐/Electronics, Nanomagnetism, and Catalysis
Authors: Hong Jinhua , Jin Chuanhong , Yuan Jun , Zhang Ze
Published: March 2017

Two‐dimensional layered graphene‐like crystals including transition‐metal dichalcogenides (TMDs) have received extensive research interest due to their diverse electronic, valleytronic, and chemical properties, with the corresponding optoelectronics and catalysis application being actively explored. However, the recent surge in two‐dimensional materials science is accompanied by equally great challenges, such as defect engineering in large‐scale sample synthesis. It is necessary to elucidate the effect of structural defects on the electronic properties in order to develop an application‐specific strategy for defect engineering. Here, two aspects of the existing knowledge of native defects in two‐dimensional crystals are reviewed. One is the point defects emerging in graphene and hexagonal boron nitride, as probed by atomically resolved electron microscopy, and their local electronic properties, as measured by single‐atom electron energy‐loss spectroscopy. The other will focus on the point defects in TMDs and their influence on the electronic structure, photoluminescence, and electric transport properties. This review of atomic defects in two‐dimensional materials will offer a clear picture of the defect physics involved to demonstrate the local modulation of the electronic properties and possible benefits in potential applications in magnetism and catalysis.
Gold and Hairpin DNA Functionalization of Upconversion Nanocrystals for Imaging and In Vivo Drug Delivery
Authors: Han Sanyang , Samanta Animesh , Xie Xiaoji , Huang Ling , Peng Juanjuan , Park Sung Jin , Teh Daniel Boon Loong , Choi Yongdoo , Chang Young‐Tae , All Angelo Homayoun , Yang Yanmei , Xing Bengang , Liu Xiaogang
Published: March 2017

Although multifunctional upconversion imaging probes have recently attracted considerable interest in biomedical research, there are currently few methods for stabilizing these luminescent nanoprobes with oligonucleotides in biological systems. Herein, a method to robustly disperse upconversion nanoprobes in physiological buffers based on rational design and synthesis of nanoconjugates comprising hairpin‐DNA‐modified gold nanoparticles is presented. This approach imparts the upconversion nanoprobes with excellent biocompatibility and circumvents the problem of particle agglomeration. By combining single‐band anti‐Stokes near‐infrared emission and the photothermal effect mediated by the coupling of gold to upconversion nanoparticles, a simple, versatile nanoparticulate system for simultaneous deep‐tissue imaging and drug molecule release in vivo is demonstrated.
Colorless‐to‐Black/Gray Electrochromic Devices Based on Single 1‐Alkyl‐1′‐Aryl Asymmetric Viologen‐Modified Monolayered Electrodes
Authors: Alesanco Yolanda , Viñuales Ana , Cabañero Germán , Rodriguez Javier , Tena‐Zaera Ramón
Published: March 2017

In the rising tendency of electrochromics and incipient development of multicolor systems, big attention is recently being paid to the colorless‐to‐black or gray electrochromic (EC) materials, since they can extend the applicability of the EC technology. However, the achievement of high performance EC materials which intrinsically provide colorless‐to‐gray/black electrochromism remains a strategic challenge. The present study reports on colorless‐to‐black/gray EC devices (ECDs) based on new 1‐alkyl‐1′‐aryl asymmetric viologens assembled in a nanostructured device configuration with poly(vinyl alcohol) (PVA)–borax gel electrolyte (conducting glass/viologen‐modified‐TiO2/PVA–borax gel electrolyte/conducting glass). The asymmetric viologens reported herein have been conveniently functionalized with anchoring groups in both alkyl and aryl substituents, ensuring rapid anchoring process (≈1 min) and strong binding affinity toward TiO2 monolayered working electrode. It is demonstrated herein that these ECDs based on a single asymmetric viologen provide not only gray but also real black electrochromism (a* and b* ≤ |5|) with great variation of the level of coloration (ΔL* = 53) and transmittance change (Δ%T ≥ 60), along with satisfactory switching times (5–10 s), transparent colorless‐off state, and good cyclability (≈10 000 cycles). Furthermore, these asymmetric viologens have also been tested in light‐scattering electrodes to prove their compatibility with them, extending their field of application.
Semiconductor‐to‐Metal Transition and Quasiparticle Renormalization in Doped Graphene Nanoribbons
Authors: Senkovskiy Boris V. , Fedorov Alexander V. , Haberer Danny , Farjam Mani , Simonov Konstantin A. , Preobrajenski Alexei B. , Mårtensson Niels , Atodiresei Nicolae , Caciuc Vasile , Blügel Stefan , Rosch Achim , Verbitskiy Nikolay I. , Hell Martin , Evtushinsky Daniil V. , German Raphael , Marangoni Tomas , van Loosdrecht Paul H. M. , Fischer Felix R. , Grüneis Alexander
Published: March 2017

A semiconductor‐to‐metal transition in N = 7 armchair graphene nanoribbons causes drastic changes in its electron and phonon system. By using angle‐resolved photoemission spectroscopy of lithium‐doped graphene nanoribbons, a quasiparticle band gap renormalization from 2.4 to 2.1 eV is observed. Reaching high doping levels (0.05 electrons per atom), it is found that the effective mass of the conduction band carriers increases to a value equal to the free electron mass. This giant increase in the effective mass by doping is a means to enhance the density of states at the Fermi level which can have palpable impact on the transport and optical properties. Electron doping also reduces the Raman intensity by one order of magnitude, and results in relatively small (4 cm−1) hardening of the G phonon and softening of the D phonon. This suggests the importance of both lattice expansion and dynamic effects. The present work highlights that doping of a semiconducting 1D system is strikingly different from its 2D or 3D counterparts and introduces doped graphene nanoribbons as a new tunable quantum material with high potential for basic research and applications.
Recent Developments in Pd0‐Catalyzed Alkene‐Carboheterofunctionalization Reactions
Authors: Garlets Zachary J. , White Derick R. , Wolfe John P.
Published: March 2017

This Focus Review summarizes recent developments in palladium‐catalyzed alkene carboalkoxylation and carboamination reactions. New synthetic methods that have been reported within the past four years are described, along with mechanistic insights and the influence of reaction mechanism on product stereochemistry. The applications of these transformations to the synthesis of natural products and other biologically relevant compounds are also discussed.
Flexible control of highly‐directive emissions based on bifunctional metasurfaces with low polarization cross‐talking
Authors: Xu He‐Xiu , Tang Shiwei , Ling Xiaohui , Luo Weijie , Zhou Lei
Published: March 2017

Achieving flexible and highly directive emissions toward pre‐designed directions has intrigued long‐held interest in both science and engineering community, but most available efforts suffer the issues of bulky size, limited functionalities, and low efficiency. Here, we propose a general strategy to efficiently and flexibly control the emission beams with dual functionalities realized independently by orthogonal excitations. To overcome the polarization cross‐talking, a novel planar multi‐mode anisotropic meta‐atom is designed by incorporating the screening effect of a surrounding wire loop. As the result, we can design the polarization‐dependent phase profile under certain polarization, without worrying about their influences on the other polarization. As an illustration, two proof‐of‐concept metasurfaces are actualized at microwave frequencies, of which one combines the functionalities of focused‐beam and large‐angle multibeam emissions while another hybrids the functionalities of beam‐steering and small‐angle multibeam emissions. Theoretical, full‐wave simulation, and experimental results are in excellent agreement with each other, which collectively demonstrate the desired performances of our bifunctional devices. Our proposed strategy paves the way to realize high‐performance multifunctional optical devices with high integration and complex wavefront manipulations.

image
Regioselektive Photoisomerisierung/C‐C‐Bindungsbildung von asymmetrischem B(ppy)(Mes)(Ar): die Rolle von Arylgruppen am Boratom
Authors: Mellerup Soren K. , Li Cally , Peng Tai , Wang Suning
Published: March 2017

Asymmetrische N,C‐chelatisierte Organoborverbindungen mit zwei unterschiedlichen Arylgruppen am Borzentrum gehen Photoisomerisierungen ein, bei denen infolge der ausschließlichen Reaktion an der weniger sperrigen Arylgruppe intensiv gefärbte “dunkle Isomere” entstehen. Diese Spezies isomerisieren thermisch durch einen direkten H‐Atomtransfer vom Boriranring auf den Pyridylring und Ringexpansion zu 4bH‐Azaborepinen. Mechanistische Einblicke in diese hoch regioselektive Umwandlung wurden sowohl aus kinetischen Daten als auch durch computergestützte Rechnungen erhalten.
Fervent Hype behind Magnesium Batteries: An Open Call to Synthetic Chemists—Electrolytes and Cathodes Needed
Authors: Muldoon John , Bucur Claudiu B. , Gregory Thomas
Published: March 2017

Magnesium metal is a superior anode which has double the volumetric capacity of lithium metal and has a negative reduction potential of −2.37 V vs. the standard hydrogen electrode. A major benefit of magnesium is the apparent lack of dendrite formation during charging which is one of the crucial concerns of using a lithium metal anode. In this Review, we highlight the foremost research in the development of electrolytes and cathodes and discuss some of the significant challenges which must be overcome in realizing a practical magnesium battery.
Modified cyclopentadienyl molybdenum compounds with enhanced cytotoxic activity towards MOLT‐4 leukaemia cells
Authors: Honzíčková Iva , Vinklárek Jaromír , Růžičková Zdeňka , Řezáčová Martina , Honzíček Jan
Published: March 2017

A series of new cyclopentadienyl molybdenum compounds bearing substituted phenanthroline ligands [(η5‐C5H4CH2C6H4X‐4)Mo(CO)2(N,NL)][BF4] (X = F, Cl, Br; N,NL = phen, 5‐NH2‐phen, 4,7‐Ph2‐phen) was prepared and characterized using infrared and NMR spectroscopies. Crystal structures of [(η5‐C5H4CH2C6H4F‐4)Mo(CO)2(NCMe)2][BF4], [(η5‐C5H4CH2C6H4X‐4)Mo(CO)2(phen)][BF4] (X = F, Cl, Br) and [(η5‐C5H4CH2C6H4Cl‐4)Mo(CO)2(4,7‐Ph2‐phen)][BF4]⋅(4,7‐Ph2‐phen)⋅HBF4 were determined using X‐ray diffraction analysis. Biological studies revealed a strong cytotoxic effect of the chelating ligands. Although the cytostatic effect of the halogen in the side chain of the cyclopentadienyl ring is negligible, it could be used for future post‐modification of these types of cytotoxic active molybdenum‐based compounds.
Randomized Controlled Trial of Rituximab and Cost‐Effectiveness Analysis in Treating Fatigue and Oral Dryness in Primary Sjögren's Syndrome
Authors: Bowman Simon J. , Everett Colin C. , O'Dwyer John L. , Emery Paul , Pitzalis Costantino , Ng Wan‐Fai , Pease Colin T. , Price Elizabeth J. , Sutcliffe Nurhan , Gendi Nagui S. T. , Hall Frances C. , Ruddock Sharon P. , Fernandez Catherine , Reynolds Catherine , Hulme Claire T. , Davies Kevin A. , Edwards Christopher J. , Lanyon Peter C. , Moots Robert J. , Roussou Euthalia , Giles Ian P. , Sharples Linda D. , Bombardieri Michele
Published: March 2017

Objective

To investigate whether rituximab, an anti–B cell therapy, improves symptoms of fatigue and oral dryness in patients with primary Sjögren's syndrome (SS).

Methods

We conducted a multicenter, randomized, double‐blind, placebo‐controlled, parallel‐group trial that included health economic analysis. Anti‐Ro–positive patients with primary SS, symptomatic fatigue, and oral dryness were recruited from 25 UK rheumatology clinics from August 2011 to January 2014. Patients were centrally randomized to receive either intravenous (IV) placebo (250 ml saline) or IV rituximab (1,000 mg in 250 ml saline) in 2 courses at weeks 0, 2, 24, and 26, with pre‐ and postinfusion medication including corticosteroids. The primary end point was the proportion of patients achieving a 30% reduction in either fatigue or oral dryness at 48 weeks, as measured by visual analog scale. Other outcome measures included salivary and lacrimal flow rates, quality of life, scores on the European League Against Rheumatism (EULAR) Sjögren's Syndrome Patient Reported Index and EULAR Sjögren's Syndrome Disease Activity Index, symptoms of ocular and overall dryness, pain, globally assessed disease activity, and cost‐effectiveness.

Results

All 133 patients who were randomized to receive placebo (n = 66) or rituximab (n = 67) were included in the primary analysis. Among patients with complete data, 21 of 56 placebo‐treated patients and 24 of 61 rituximab‐treated patients achieved the primary end point. After multiple imputation of missing outcomes, response rates in the placebo and rituximab groups were 36.8% and 39.8%, respectively (adjusted odds ratio 1.13 [95% confidence interval 0.50, 2.55]). There were no significant improvements in any outcome measure except for unstimulated salivary flow. The mean ± SD costs per patient for rituximab and placebo were £10,752 ± 264.75 and £2,672 ± 241.71, respectively. There were slightly more adverse events (AEs) reported in total for rituximab, but there was no difference in serious AEs (10 in each group).

Conclusion

The results of this study indicate that rituximab is neither clinically effective nor cost‐effective in this patient population.
Sequential Functionalization of a Natural Crosslinker Leads to Designer Silicone Networks
Authors: Laengert Scott E. , Schneider Alyssa F. , Lovinger Eric , Chen Yang , Brook Michael A.
Published: March 2017

Precise silicone networks are difficult to prepare from multiple starting materials because of poor spatial control over crosslink location, competing side reactions, and incompatible catalysts among other reasons. We demonstrate that cure processes catalyzed by B(C6F5)3 (the Piers–Rubinsztajn reaction) and platinum‐catalyzed hydrosilylation are perfectly compatible, and can be used in either order. It is possible to perform three different, selective, sequential reactions in the same pot using H‐terminated silicones as chain extenders in all cases to give explicit networks. Eugenol, a readily available aromatic compound, acts as a trifunctional crosslinker (HO, MeO, HC=CH2), each functional group of which can be induced to undergo selective reaction. With platinum catalysis, the reaction of SiH groups with alkenes is fastest, while B(C6F5)3 catalyzes reaction at phenols much faster than methoxybenzene. Thus, a variety of H‐terminated telechelic siloxanes can be used to form chain extended polymers or elastomers or foams in which the morphology of the material and its constituent parts can be manipulated at will.
Taylor polynomial Approximation and Adaptive Passivity‐Based Control Applied to the Level Regulation of a Conical Tank
Authors: Travieso‐Torres Juan Carlos , Duarte‐Mermoud Manuel A. , Beytía‐Cancino Orlando
Published: March 2017

The techniques of Taylor polynomial approximation (TPA) and adaptive passivity‐based controller (APBC) are combined in this study and applied to the level regulation of a conical tank. The design and comparative experimental results with a classical PI controller are presented. After combining these two approaches a robust adaptive controller named TPA–APBC, which is simpler than the classical APBC and PI controller, is obtained. This new TPA–APBC preserves the stability of the overall system after assuming that the nonlinear system is unknown and that it can be suitably represented by a first‐order linear model with unknown parameters.
Delivery of growth factor‐based therapeutics in vascular diseases: Challenges and strategies
Authors: Xu He‐Lin , Yu Wen‐Ze , Lu Cui‐Tao , Li Xiao‐Kun , Zhao Ying‐Zheng
Published: March 2017

Either cardiovascular or peripheral vascular diseases have become the major cause of morbidity and mortality worldwide. Recently, growth factors therapeutics, whatever administrated in form of exogenous growth factors or their relevant genes have been discovered to be an effective strategy for the prevention and therapy of vascular diseases, because of their promoting angiogenesis. Besides, as an alternative, stem cell‐based therapy has been also developed in view of their paracrine‐mediated effect or ability of differentiation toward angiogenesis‐related cells under assistance of growth factors. Despite of being specific and potent, no matter growth factors or stem cells‐based therapy, their full clinical transformation is limited from bench to bedside. In this review, the potential choices of therapeutic modes based on types of different growth factors or stem cells were firstly summarized for vascular diseases. The confronted various challenges such as lack of non‐invasive delivery method, the physiochemical challenge, the short half‐life time, and poor cell survival, were carefully analyzed for these therapeutic modes. Various strategies to overcome these limitations are put forward from the perspective of drug delivery. The expertised design of a suitable delivery form will undoubtedly provide valuable insight into their clinical application in the regenerative medicine.
Cultivation‐based strategies to find efficient marine biocatalysts
Authors: Rodrigues Carlos J. C. , Pereira Ricardo F.S. , Fernandes Pedro , Cabral Joaquim M.S. , de Carvalho Carla C. C. R.
Published: March 2017

Marine bacteria have evolved to survive in the marine environment by using unique physiological, biochemical and metabolic features and the ability to produce enzymes and compounds which may have commercial value. The Azores archipelago presents several ecosystems with strong volcanic activity where bacteria thrive under e.g. high temperatures. In this study, samples collected in the island of São Miguel were screened for biocatalysts possessing e.g. lipase, esterase, amylase, and inulinase activities. After isolation of several hundred bacterial strains, high throughput screening methods allowed the fast identification of biocatalysts. The first cultivation tests were performed on 24‐wells microtiter plates with online oxygen monitoring and bacteria able to grow within 24 h were selected for further process development. Bacteria able to produce the desired enzymes were selected for the first round of tests. Four Bacillus strains presented high inulinase activity. The next step in process development was the determination of key parameters for enzyme activity such as temperature, pH, salinity and substrate concentration. The highest inulinase activity, 2.2 gsugars/gprotein h, was attained when the supernatant of a culture of a Bacillus subtilis strain was used in a magnetically stirred bioreactor. This study demonstrates how bacterial strains from marine environments may be used successfully in biotechnological processes.
A simple and cost‐effective HPLC‐UV method for the detection of levetiracetam in plasma/serum of patients with epilepsy
Authors: Engelbrecht Lynette , Grobler C. J. , Rheeders Malie
Published: March 2017

A simple, fast and cost‐effective method was developed and validated for the determination of levetiracetam (LEV) in plasma/serum of patients using high performance liquid chromatography (HPLC) with ultraviolet detection. The stability of LEV plasma/serum samples over time and in different blood collection tubes was evaluated. Serum/plasma samples were deproteinized by methanol spiked with the internal standard, gabapentin. HPLC was carried out on a Venusil XBP C18, 250 × 4.6 mm, 5 μm column, at a flow rate of 1.0 mL/min and with mobile phase consisting of 50 mm potassium dihydrogen phosphate–acetonitrile at a pH of 5.5. The UV detector was set at 205 nm and 10 μL was injected. Total runtime was 15 min. Calibration curves were linear (correlation coefficient = 0.999) over a concentration range of 1–60 μg/mL. Relative standard deviation values for both the inter‐day and intra‐day precision and accuracy were <5% for the concentration range. The influence of different collection tubes and the effect of time on the stability of LEV was investigated. These factors may cause inaccuracies owing to drug–protein binding and interference in the matrix. This method is simple, fast, cost‐effective, reliable and accurate with minimal sample preparation for daily routine use in therapeutic drug monitoring.
Development of an LC–MS/MS method for quantification of two pairs of isomeric flavonoid glycosides and other ones in rat plasma: Application to pharmacokinetic studies
Authors: Zhang Sixi , Xie Yang , Wang Jing , Geng Yanmei , Zhou Yu , Sun Chengxin , Wang Guangshu
Published: March 2017

A liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed and validated for simultaneous determination of six flavonoid glycosides – isoorientin (1), orientin (2), 2″‐O‐β‐d‐xylopyranosyl isoorientin (3), 2″‐O‐β‐d‐xylopyranosyl isovitexin (4), 6‐C‐l‐α‐arabipyranosyl vitexin (5) and vitexin (6) – in rat plasma using isoquercitrin as the internal standard (IS). Plasma samples were prepared by a one‐step protein precipitation with acetonitrile. Chromatographic analysis was carried out on a 25 cm C18 column with a gradient mobile phase consisting of acetonitrile and 0.1% aqueous formic acid. Six analytes and IS were detected through electrospray ionization in negative‐ion selection reaction monitoring mode. The mass transitions were as follows: m/z 447.2 → 327.0 for 1, m/z 447.2 → 327.0 for 2, m/z 579.3 → 458.9 for 3, m/z 563.0 → 293.1 for 4, m/z 563.0 → 353.0 for 5, m/z 431.1 → 311.1 for 6, and m/z 463.1 → 300.2 for IS. Calibration curves exhibited good linearity (r2 > 0.9908) over a wide concentration range for all compounds. Intra‐ and inter‐day precision (RSD, %) at four different levels were both <14.2% and the accuracy (RE, %) ranged from −11.9 to 12.0%. The extraction recoveries of the six components ranged from 88.2 to 103.6%. The validated assay was successfully applied to the pharmacokinetic studies of the six components in male rat plasma after intravenous administration of total flavonoids of Scorzonera austriaca Wild.
Emerging applications of exosomes in cancer therapeutics and diagnostics
Authors: Inamdar Sahil , Nitiyanandan Rajeshwar , Rege Kaushal
Published: March 2017

Exosomes are nanoscale extracellular vesicles that are shed from different cells in the body. Exosomes encapsulate several biomolecules including lipids, proteins, and nucleic acids, and can therefore play a key role in cellular communication. These vesicles can be isolated from different body fluids and their small sizes make them attractive in various biomedical applications. Here, we review state‐of‐the art approaches in exosome isolation and purification, and describe their potential use in cancer vaccines, drug delivery, and diagnostics.
Study of normal volumetric variation in the putamen with age and sex using magnetic resonance imaging
Authors: Halkur Shankar Sujay , Ballal Sandeep , Shubha R.
Published: March 2017

Putamen volume is seen to alter in neurological and psychiatric disorders like Parkinson's disease, depression, schizophrenia, Alzheimer's disease, and in individuals treated with antipsychotics. To establish a trend in volume changes in pathologic states, studies on factors influencing normal variation in a given population become essential. This study aimed to evaluate the normal variations in putamen volume in the Indian population and correlate them with the effects of age and sex. Bilateral symmetry was also evaluated. The study included MR images of 98 individuals aged 10–87 years. Axial sections of T2‐weighted spin echo sequences were used to estimate putamen volume. The putamen was delineated manually and its volume was estimated using Cavalieri's principle. Linear regression and paired t‐test were used to analyze data. Bilateral putamen volume reduced with age in both sexes. This was statistically significant (P < 0.05) except for the left putamen volume in males. There was no significant age‐adjusted effect of sex on putamen volume in both hemispheres (P > 0.05). Age and sex interaction was not found to be statistically significant. Hemispherical asymmetry was not established as the difference between the right and left putamen volume did not reach statistical significance in both males and females (P > 0.05). In conclusion, this study demonstrated an age related decline in the volumes of both putamen in males and females. The rate of volume reduction was not affected by sex. The study failed to establish a significant sex difference and hemispherical asymmetry in putamen volume. Clin. Anat. 30:461–466, 2017. © 2017 Wiley Periodicals, Inc.
The innominate tubercle of the femur: Application to anterior surgical approaches to the hip
Authors: Kielbasinski Podlaszewska O. , Bekvalac J. , Williams R.L. , Adds P.J.
Published: March 2017

There has recently been an increase in popularity of the direct anterior approach (DAA) hip arthroplasty, due to the muscle sparing nature of its interneural intervals, with the innominate tubercle being used as a lateral reference point for the femoral neck osteotomy. However, there is very little information in the literature on this rather enigmatic structure, with no evidence as to whether it is a consistent and reliable marker, or if it varies significantly in the population. In this study, data were gathered from 79 pairs of adult, post‐medieval skeletal femora to investigate the effects of sex, age, femoral side, femoral length, femoral neck length, and femoral neck‐shaft angle on the width, length, and height of the innominate tubercle. The sex, age, and date of death of the individuals had been recorded. Statistical analysis included canonical correlation and multivariate multiple regression. We found that there was no statistical significance or correlation between the width, length, or height of the tubercle with respect to any of the variables investigated. These results suggest that the innominate tubercle does not differ markedly between individuals in the Caucasian population, and, is therefore, a reliable landmark for femoral neck osteotomy during DAA hip arthroplasty. We present what we believe to be a definitive survey of the variability of the innominate tubercle in a Caucasian population. Clin. Anat. 30:578–584, 2017. © 2017 Wiley Periodicals, Inc.
A New 1,5‐Dihydroxy‐4‐methoxyisoquinoline from Scolopendra subspinipes mutilans
Authors: Guo Ya‐Ru , Wu Peng‐Xiang , Xu Han‐Mei , Qi Wei‐Yan
Published: March 2017

A new isoquinoline, 1,5‐dihydroxy‐4‐methoxyisoquinoline (1), was obtained from Scolopendra subspinipes mutilans. Compound 1 showed moderate cytotoxicity on tumour cells with IC50 values ranging from 13 to 26 μm against five esophageal squamous cancer cells whereas low cytotoxicity against normal human esophageal epithelial cells. Isoquinoline ring oxidized at C(1), C(4), and C(5) can enhance its cytotoxicity. In addition, compound 1 showed potent inhibitory effect (inhibition rate > 50% at 13 μm) on cell migration in human umbilical vein endothelial cells. This article mainly studies the structure and activity of 1, and more modification of 1 as a potential anticancer agent.
Discovering Drugs with DNA‐Encoded Library Technology: From Concept to Clinic with an Inhibitor of Soluble Epoxide Hydrolase
Authors: Belyanskaya Svetlana L. , Ding Yun , Callahan James F. , Lazaar Aili L. , Israel David I.
Published: March 2017

DNA‐encoded chemical library technology was developed with the vision of its becoming a transformational platform for drug discovery. The hope was that a new paradigm for the discovery of low‐molecular‐weight drugs would be enabled by combining the vast molecular diversity achievable with combinatorial chemistry, the information‐encoding attributes of DNA, the power of molecular biology, and a streamlined selection‐based discovery process. Here, we describe the discovery and early clinical development of GSK2256294, an inhibitor of soluble epoxide hydrolase (sEH, EPHX2), by using encoded‐library technology (ELT). GSK2256294 is an orally bioavailable, potent and selective inhibitor of sEH that has a long half life and produced no serious adverse events in a first‐time‐in‐human clinical study. To our knowledge, GSK2256294 is the first molecule discovered from this technology to enter human clinical testing and represents a realization of the vision that DNA‐encoded chemical library technology can efficiently yield molecules with favorable properties that can be readily progressed into high‐quality drugs.
Oxidation of d‐Glucose to Glucaric Acid Using Au/C Catalysts
Authors: Solmi Stefania , Morreale Calogero , Ospitali Francesca , Agnoli Stefano , Cavani Fabrizio
Published: March 2017

The reactivity of Au and AuBi nanoparticles supported on activated carbon AC was investigated in the direct oxidation of glucose to glucaric acid. The catalysts were very active, regardless of the Au nanoparticles size, but the catalyst with the smallest average particle diameter was the least selective to glucaric acid because of the enhanced consecutive oxidative degradation of the intermediately formed gluconic acid. The reaction network included the fast oxidation of glucose to gluconic acid, which was the only primary product, and its consecutive oxidation into either glucaric acid or lighter mono and dicarboxylic acids. The best glucaric acid yield obtained with a AuBi/AC catalyst (Au/Bi 3:1) was 31 %, with 18 % residual gluconic acid. The control of reaction parameters was essential to achieving the best selectivity. Specifically, the glucose concentration turned out to be a critical parameter in relation to O2 pressure and to glucose/metal ratio.