bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of diffuse seafloor venting using a structured light laser sensor: 1. Development of a classification based detection method
Authors: Smart Clara , Roman Chris , Carey Steven
Published: June 2017

Systematic and remote detection of diffuse hydrothermal venting is complex yet necessary to establish a comprehensive understanding the distribution, contribution, and context of fluid flow within hydrothermal systems. Diffuse flow is characterized by both low temperature and low flow rates and cannot be consistently distinguished during extensive systematic surveys using current vehicle‐mounted visual, acoustic, or environmental sensors. The remotely operated vehicle‐mounted structured light laser sensor is sensitive to fluid density anomalies and seafloor characteristics. Presented advancements to the detection algorithm include the development and implementation of intensity normalization routines and a support vector machine classification algorithm. The resulting comprehensive maps establish the spatial distribution of potential hydrothermal vents and associated bacteria within a vent field.
Distribution pattern and mass budget of sedimentary polycyclic aromatic hydrocarbons in shelf areas of the Eastern China Marginal Seas
Authors: Wang C. L. , Zou X. Q. , Zhao Y. F. , Li Y. L. , Song Q. C. , Wang T. , Yu W. W.
Published: June 2017

This study conducted the first extensive and comprehensive investigation of the regional‐scale sedimentary polycyclic aromatic hydrocarbons (PAHs) concentration, flux, and budget in the continental shelves of the Eastern China Marginal Seas (ECMSs). Surface sediment samples from multiple sites were collected and assessed, and the latest data from current research were assessed. The spatial distribution pattern of PAHs in the ECMSs was significantly influenced by the regional hydrodynamics, sediment properties (grain‐size, total organic carbon [TOC] content, and sedimentation rate), and anthropogenic impacts. Relatively higher PAHs concentrations occurred in areas with fine‐grained sediment. Results of source apportionment found that the relative proportions of PAHs showed significant regional variation, mainly influenced by socioeconomic differences between north and south China. The PAHs burial flux in the study area ranged from 11.2 to 1308 ng cm−2 yr−1 with an average value of 101 ± 104 ng cm−2 yr−1. The area‐integrated sedimentary PAHs burial flux across the ECMSs was 494 t yr−1. A mass budget calculation revealed that riverine input and atmospheric deposition were the most significant sources contributing, 28.4% and 71.6%, respectively. The study demonstrated that net PAHs transportation occurs between the Bohai Sea (BS) and Yellow Sea (YS), with a flux of approximately 10.2 t yr−1. PAHs were also transported from YS to the East China Sea (ECS), due to water exchange between the YS and ECS. Additionally, substantial amounts of PAHs in the inner shelf of the ECS were transported out of the shelf area due to cross‐shelf plume.
MR‐safe personal radiation dosimeters
Authors: Tchistiakova E. , Kim A. , Song W. Y. , Pang G.
Published: June 2017

Magnetic resonance imaging (MRI) is being rapidly integrated for cancer treatments—such systems are referred to as MRI‐guided radiation therapy (MRIgRT). As the magnet of an MRI scanner is always on, the presence of a strong static magnetic field from the MRI scanner during radiotherapy delivery presents new challenges. One of the challenges is that a personal radiation dosimeter used to estimate the radiation dose deposited in an individual wearing the device must be MR‐safe. No such devices, however, are currently available. In this work we first modified an existing personal dosimeter (by removing a metal clip) to make it MR‐safe and then investigated potential effects of magnetic field on dosimeter readings, i.e., optically stimulated luminescent dosimeter (OSLD) readings. We found that the effect of magnetic field on OSLD sensitivity was within radiation protection tolerance levels. OSLD personal dosimeters can be directly used in conjunction with MRIgRT radiation protection purposes.
Proximal flow to middle cerebral artery is associated with higher thrombus density in terminal internal carotid artery occlusion
Authors: Pikija Slaven , Magdic Jozef , Killer‐Oberpfalzer Monika , Florea Cristina , Hauer Larissa , Novak Helmut F. , McCoy Mark R. , Sellner Johann
Published: June 2017

Proximal collaterals may determine the composition of occluding thrombi in acute ischemic stroke (AIS) in addition to source, hematocrit, time, and medication. Here, we performed a retrospective study of 39 consecutive patients with radiological evidence of I‐, L‐, and T‐type terminal internal carotid artery occlusion. Middle cerebral artery (MCA) thrombus density was assessed on noncontrast enhanced CT and proximal collaterals on CT angiography. In patients with presence of proximal collaterals to the MCA we detected more hyperdense clots (P = 0.003) and a higher frequency of leptomeningeal collaterals (P = 0.008). We expand the spectrum of factors that potentially determine clot perviousness and evolution of ischemic stroke.
Statistical Bias and Endorsement of Conspiracy Theories
Authors: Dagnall Neil , Denovan Andrew , Drinkwater Kenneth , Parker Andrew , Clough Peter
Published: June 2017

Previous research proposes that endorsement of anomalous beliefs is associated with proneness to conjunction error. This supposition ignores important differences between belief types. Correspondingly, the present study examined the degree to which components of statistical bias predicted conspiratorial ideation and belief in the paranormal. Confirmatory factor analysis and structural equation modelling revealed that conjunction error was associated with conspiratorial ideation, whilst perception of randomness most strongly predicted belief in the paranormal. These findings opposed the notion that anomalous beliefs, by virtue of possession of common characteristics, relate similarly to conjunction error. With regard to conspiracy, conjunction‐framing manipulations produced only minor variations in relationship strength. This supported the notion that conspiratorial ideation was associated with a domain‐general susceptibility to conjunction error. Framing, however, did influence the relationship between belief in the paranormal and conjunction; whilst paranormal conjunctions were generally easier to solve, performance declined as level of paranormal belief increased.Copyright © 2017 John Wiley & Sons, Ltd.
An online optimum voltage estimation and real‐time MPP tracking for a PV system
Authors: Farhat Maissa , Barambones Oscar , Sbita Lassâad
Published: June 2017

In this paper, a photovoltaic system topology incorporating a new maximum power point tracking (MPPT) controller method is presented. This method uses an autotuning estimator and a PI controller to make the system work in the maximum power point. The controller is formulated based on the bijectivity in the photovoltaic generator characteristic; therefore, if the optimal voltage is reached, this means that the maximum of power is obtained. The proposed MPPT algorithm is implemented on a dSpace DS1104 controller board. In order to demonstrate the efficiency of the proposed algorithm in real time, an experimental setup using a boost converter connected to a resistive load is successfully implemented and studied. The obtained experimental results prove the validity of the proposed MPPT algorithm.
Enhancing Photodynamic Therapy through Resonance Energy Transfer Constructed Near‐Infrared Photosensitized Nanoparticles
Authors: Huang Ling , Li Zhanjun , Zhao Yang , Yang Jinyi , Yang Yucheng , Pendharkar Aarushi Iris , Zhang Yuanwei , Kelmar Sharon , Chen Liyong , Wu Wenting , Zhao Jianzhang , Han Gang
Published: June 2017

Photodynamic therapy (PDT) is an important cancer treatment modality due to its minimally invasive nature. However, the efficiency of existing PDT drug molecules in the deep‐tissue‐penetrable near‐infrared (NIR) region has been the major hurdle that has hindered further development and clinical usage of PDT. Thus, herein a strategy is presented to utilize a resonance energy transfer (RET) mechanism to construct a novel dyad photosensitizer which is able to dramatically boost NIR photon utility and enhance singlet oxygen generation. In this work, the energy donor moiety (distyryl‐BODIPY) is connected to a photosensitizer (i.e., diiodo‐distyryl‐BODIPY) to form a dyad molecule (RET‐BDP). The resulting RET‐BDP shows significantly enhanced absorption and singlet oxygen efficiency relative to that of the acceptor moiety of the photosensitizer alone in the NIR range. After being encapsulated with biodegradable copolymer pluronic F‐127‐folic acid (F‐127‐FA), RET‐BDP molecules can form uniform and small organic nanoparticles that are water soluble and tumor targetable. Used in conjunction with an exceptionally low‐power NIR LED light irradiation (10 mW cm−2), these nanoparticles show superior tumor‐targeted therapeutic PDT effects against cancer cells both in vitro and in vivo relative to unmodified photosensitizers. This study offers a new method to expand the options for designing NIR‐absorbing photosensitizers for future clinical cancer treatments.
Tunable Photocontrolled Motions Using Stored Strain Energy in Malleable Azobenzene Liquid Crystalline Polymer Actuators
Authors: Lu Xili , Guo Shengwei , Tong Xia , Xia Hesheng , Zhao Yue
Published: June 2017

A new strategy for enhancing the photoinduced mechanical force is demonstrated using a reprocessable azobenzene‐containing liquid crystalline network (LCN). The basic idea is to store mechanical strain energy in the polymer beforehand so that UV light can then be used to generate a mechanical force not only from the direct light to mechanical energy conversion upon the trans–cis photoisomerization of azobenzene mesogens but also from the light‐triggered release of the prestored strain energy. It is shown that the two mechanisms can add up to result in unprecedented photoindued mechanical force. Together with the malleability of the polymer stemming from the use of dynamic covalent bonds for chain crosslinking, large‐size polymer photoactuators in the form of wheels or spring‐like “motors” can be constructed, and, by adjusting the amount of prestored strain energy in the polymer, a variety of robust, light‐driven motions with tunable rolling or moving direction and speed can be achieved. The approach of prestoring a controllable amount of strain energy to obtain a strong and tunable photoinduced mechanical force in azobenzene LCN can be further explored for applications of light‐driven polymer actuators.
Reliable Piezoelectricity in Bilayer WSe2 for Piezoelectric Nanogenerators
Authors: Lee Ju‐Hyuck , Park Jae Young , Cho Eun Bi , Kim Tae Yun , Han Sang A. , Kim Tae‐Ho , Liu Yanan , Kim Sung Kyun , Roh Chang Jae , Yoon Hong‐Joon , Ryu Hanjun , Seung Wanchul , Lee Jong Seok , Lee Jaichan , Kim Sang‐Woo
Published: June 2017

Recently, piezoelectricity has been observed in 2D atomically thin materials, such as hexagonal‐boron nitride, graphene, and transition metal dichalcogenides (TMDs). Specifically, exfoliated monolayer MoS2 exhibits a high piezoelectricity that is comparable to that of traditional piezoelectric materials. However, monolayer TMD materials are not regarded as suitable for actual piezoelectric devices due to their insufficient mechanical durability for sustained operation while Bernal‐stacked bilayer TMD materials lose noncentrosymmetry and consequently piezoelectricity. Here, it is shown that WSe2 bilayers fabricated via turbostratic stacking have reliable piezoelectric properties that cannot be obtained from a mechanically exfoliated WSe2 bilayer with Bernal stacking. Turbostratic stacking refers to the transfer of each chemical vapor deposition (CVD)‐grown WSe2 monolayer to allow for an increase in degrees of freedom in the bilayer symmetry, leading to noncentrosymmetry in the bilayers. In contrast, CVD‐grown WSe2 bilayers exhibit very weak piezoelectricity because of the energetics and crystallographic orientation. The flexible piezoelectric WSe2 bilayers exhibit a prominent mechanical durability of up to 0.95% of strain as well as reliable energy harvesting performance, which is adequate to drive a small liquid crystal display without external energy sources, in contrast to monolayer WSe2 for which the device performance becomes degraded above a strain of 0.63%.
Approaching Intra‐ and Interchain Charge Transport of Conjugated Polymers Facilely by Topochemical Polymerized Single Crystals
Authors: Yao Yifan , Dong Huanli , Liu Feng , Russell Thomas P. , Hu Wenping
Published: June 2017

Charge transport of small molecules is measured well with scanning tunneling microscopy, conducting atomic force microscopy, break junction, nanopore, and covalently bridging gaps. However, the manipulation and measurement of polymer chains remain a long‐standing fundamental issue in conjugated polymers and full of challenge since conjugated polymers are naturally disordered materials. Here, a fundamental breakthrough in generating high‐quality conjugated‐polymer nanocrystals with extended conjugation and exceptionally high degrees of order using a surface‐supported topochemical polymerization method is demonstrated. In the crystal the conjugated‐polymer chains are extended along the long axis of the crystal with the side chains perpendicular to the long axis. Devices with conducting channels along the polymer chains show efficient charge transport, nearly two orders of magnitude greater than the interchain charge transport along the π–π stacking direction. This is the first example to clarify intra‐ and interchain charge transport based on an individual single crystal of conjugated polymers, and demonstrate the importance of intrachain charge transport in plastic electronics.
Metasurfaces and Colloidal Suspensions Composed of 3D Chiral Si Nanoresonators
Authors: Verre Ruggero , Shao Lei , Odebo Länk Nils , Karpinski Pawel , Yankovich Andrew B. , Antosiewicz Tomasz J. , Olsson Eva , Käll Mikael
Published: June 2017

High‐refractive‐index silicon nanoresonators are promising low‐loss alternatives to plasmonic particles in CMOS‐compatible nanophotonics applications. However, complex 3D particle morphologies are challenging to realize in practice, thus limiting the range of achievable optical functionalities. Using 3D film structuring and a novel gradient mask transfer technique, the first intrinsically chiral dielectric metasurface is fabricated in the form of a monolayer of twisted silicon nanocrescents that can be easily detached and dissolved into colloidal suspension. The metasurfaces exhibit selective handedness and a circular dichroism as large as 160° µm−1 due to pronounced differences in induced current loops for left‐handed and right‐handed polarization. The detailed morphology of the detached particles is analyzed using high‐resolution transmission electron microscopy. Furthermore, it is shown that the particles can be manipulated in solution using optical tweezers. The fabrication and detachment method can be extended to different nanoparticle geometries and paves the way for a wide range of novel nanophotonic experiments and applications of high‐index dielectrics.
A High‐Performance Li–O2 Battery with a Strongly Solvating Hexamethylphosphoramide Electrolyte and a LiPON‐Protected Lithium Anode
Authors: Zhou Bin , Guo Limin , Zhang Yantao , Wang Jiawei , Ma Lipo , Zhang Wen‐Hua , Fu Zhengwen , Peng Zhangquan
Published: June 2017

The aprotic Li–O2 battery has attracted a great deal of interest because theoretically it can store more energy than today's Li‐ion batteries. However, current Li–O2 batteries suffer from passivation/clogging of the cathode by discharged Li2O2, high charging voltage for its subsequent oxidation, and accumulation of side reaction products (particularly Li2CO3 and LiOH) upon cycling. Here, an advanced Li–O2 battery with a hexamethylphosphoramide (HMPA) electrolyte is reported that can dissolve Li2O2, Li2CO3, and LiOH up to 0.35, 0.36, and 1.11 × 10−3m, respectively, and a LiPON‐protected lithium anode that can be reversibly cycled in the HMPA electrolyte. Compared to the benchmark of ether‐based Li–O2 batteries, improved capacity, rate capability, voltaic efficiency, and cycle life are achieved for the HMPA‐based Li–O2 cells. More importantly, a combination of advanced research techniques provide compelling evidence that operation of the HMPA‐based Li–O2 battery is backed by nearly reversible formation/decomposition of Li2O2 with negligible side reactions.
Real‐Time Observation of Carbon Nanotube Etching Process Using Polarized Optical Microscope
Authors: Zhao Qiuchen , Yao Fengrui , Wang Zequn , Deng Shibin , Tong Lianming , Liu Kaihui , Zhang Jin
Published: June 2017

Controllable synthesis of carbon nanotubes (CNTs) is of great importance in its further application, which attracts broad attention. As growth and etching are the two sides in the process of material crystallography and the control of the competition between them forms the foundation for modern technology of materials design and manufacture, the understanding on etching process of carbon nanotubes is still very unclear because technically it is of great challenge to characterize the dynamics in such small one‐dimensional (1D) scale. Here the real‐time investigation on the etching process of CNTs is reported, by the hot‐wall chemical reactor equipped with a polarized optical microscope. It is discovered that the CNT etching behavior in air is totally of random, including the etching sites, termination sites, and structure dependence. Combining with the dynamic simulation, it is revealed that the random behavior reflects the unique “self‐termination” phenomenon. A structure‐independent etching propagation barrier of 2.4 eV is also obtained, which indicates that the etching propagation process still follows the conventional Kinetic Wulff construction theory. The results represent the new knowledge on the etching process in carbon nanotube and can contribute to its selective enrichment. Furthermore, the “self‐termination” phenomenon may be a universal behavior in 1D process.
Enhancing the Regeneration Process of Consumed NaBH4 for Hydrogen Storage
Authors: Ouyang Liuzhang , Chen Wei , Liu Jiangwen , Felderhoff Michael , Wang Hui , Zhu Min
Published: June 2017

Sodium borohydride (NaBH4) is regarded as an excellent hydrogen‐generated material, but its irreversibility of hydrolysis and high cost of regeneration restrict its large‐scale application. In this study a convenient and economical method for NaBH4 regeneration is developed for the first time without hydrides used as starting materials for the reduction process. The real hydrolysis by‐products (NaBO2·2H2O and NaBO2·4H2O), instead of dehydrated sodium metaborate (NaBO2), are applied for the regeneration of NaBH4 with Mg at room temperature and atmospheric pressure. Therefore, the troublesome heat‐wasting process to obtain NaBO2 using a drying procedure at over 350 °C from NaBO2·xH2O is omitted. Moreover, the highest regeneration yields of NaBH4 are achieved to date with 68.55% and 64.06% from reaction with NaBO2·2H2O and NaBO2·4H2O, respectively. The cost of NaBH4 regeneration shows a 34‐fold reduction compared to the previous study that uses MgH2 as the reduction agent, where H2 is obtained from a separate process. Furthermore, the regeneration mechanism of NaBH4 is clarified and the intermediate compound, NaBH3(OH), is successfully observed for the first time during the regeneration process.
Epileptic networks in action: Synchrony between distant hemodynamic responses
Authors: Khoo Hui Ming , von Ellenrieder Nicolás , Zazubovits Natalja , Dubeau François , Gotman Jean
Published: June 2017

Objective

Structural and functional imaging studies in focal epilepsy often reveal distributed regions of abnormality. These are interpreted as representing the existence of epileptic networks, but the presence of actual neuronal interactions between these regions has not been demonstrated. We sought to determine whether the distributed hemodynamic responses often seen in functional magnetic resonance imaging (fMRI) studies of scalp interictal epileptic discharges (IEDs) actually correspond to synchronized neuronal activities when examining the intracerebral electroencephalogram (iEEG) at distant nodes of the network.

Methods

We studied 28 patients who underwent first EEG‐fMRI and then iEEG, and had significant hemodynamic responses in the gray matter. We coregistered the hemodynamic responses to the iEEG electrode contact positions and analyzed synchrony, measured by correlation, between IEDs recorded by iEEG in regions with and without hemodynamic responses.

Results

The synchrony of intracerebral IED activity between pairs of regions showing a hemodynamic response was higher compared to that between pairs of regions without (p < 0.0001) and between pairs of regions, one with and one without hemodynamic response (p < 0.0001). These differences were found during the interictal periods with IEDs but were absent during the interictal periods without IEDs. Higher synchrony was also observed between regions involved at seizure onset (p < 0.0001).

Interpretation

EEG‐fMRI studies are unique in their ability to reveal hemodynamic concomitants of IEDs anywhere in the brain. This study proves that iEEG activity is synchronized between these regions of hemodynamic response, thus demonstrating the existence of an actual neuronally based interictal epileptic network. This also validates the EEG‐fMRI approach to reveal this network noninvasively. Ann Neurol 2017;82:57–66
Synthesis and Reactivity of Fluoroalkyl Copper Complexes by the Oxycupration of Tetrafluoroethylene
Authors: Ohashi Masato , Adachi Takuya , Ishida Naoyoshi , Kikushima Kotaro , Ogoshi Sensuke
Published: June 2017

The copper(I)‐mediated generation of ‐OCF2CF2‐ moieties by the oxycupration of tetrafluoroethylene (TFE) using either copper aryloxides or alkoxides is disclosed. The key intermediates, 2‐aryloxy‐1,1,2,2‐tetrafluoroethyl and 2‐alkoxy‐1,1,2,2‐tetrafluoroethyl copper complexes, were obtained from the reaction of the corresponding aryloxy and alkoxy copper complexes with TFE, and their structures in solution and in the solid state were unambiguously determined by multinuclear NMR spectroscopy and X‐ray diffraction analysis. These copper complexes subsequently reacted with aryl iodides (ArI) to afford ROCF2CF2Ar (R=aryl or alkyl) in high yields.
1,4‐Diphosphinine aus Imidazol‐2‐thionen
Authors: Koner Abhishek , Pfeifer Gregor , Kelemen Zsolt , Schnakenburg Gregor , Nyulászi László , Sasamori Takahiro , Streubel Rainer
Published: June 2017

1,4‐Diphosphinine, substituiert mit zwei Thioharnstoff‐Gruppen, wurden aus tricyclischen 1,4‐Dichlor‐1,4‐dihydro‐1,4‐diphosphininen synthetisiert. Ihre Strukturen und spektroskopischen Eigenschaften werden beschrieben. Elektrochemische Untersuchungen zeigen sehr niedrige Oxidationspotentiale, bedingt durch effektive π‐Wechselwirkungen zwischen dem 1,4‐Diphosphinin‐Ring und den Orbitalen der beiden ylidischen C=S‐Bindungen. In Übereinstimmung mit dem niedrig liegenden LUMO, das größtenteils an den zwei Phosphorzentren lokalisiert ist, wird die Dianion‐Bildung stark bevorzugt. Trotz des kleinen HOMO‐LUMO‐Abstands, der in Einklang mit der roten Farbe der Titelverbindung ist, legen theoretische Rechnungen eine beträchtliche Aromatizität des 1,4‐Diphosphinin‐Ringes nahe.
One Model, Two Enzymes: Activation of Hydrogen and Carbon Monoxide
Authors: Ogo Seiji , Mori Yuki , Ando Tatsuya , Matsumoto Takahiro , Yatabe Takeshi , Yoon Ki‐Seok , Hayashi Hideki , Asano Masashi
Published: June 2017

The ability to catalyze the oxidation of both H2 and CO in one reaction pot would be a major boon to hydrogen technology since CO is a consistent contaminant of H2 supplies. Here, we report just such a catalyst, with the ability to catalyze the oxidation of either or both H2 and CO, based on the pH value. This catalyst is based on a NiIr core that mimics the chemical function of [NiFe]hydrogenase in acidic media (pH 4–7) and carbon monoxide dehydrogenase in basic media (pH 7–10). We have applied this catalyst in a demonstration fuel cell using H2, CO, and H2/CO (1/1) feeds as fuels for oxidation at the anode. The power density of the fuel cell depends on the pH value in the media of the fuel cell and shows a similar pH dependence in a flask. We have isolated and characterized all intermediates in our proposed catalytic cycles.
Diastereoselective Total Synthesis of the Euphorbia Diterpenoid Pepluanol A: A Reductive Annulation Approach
Authors: Xuan Jun , Liu Zhaobo , Zhu An , Rao Peirong , Yu Lei , Ding Hanfeng
Published: June 2017

A new titanium(III)‐catalyzed reductive annulation constructed a series of diversely functionalized 1,5‐diols in good to excellent yields with respect to a wide scope of vinyl epoxide‐aldehyde substrates. Taken together with a Diels–Alder reaction and a substrate‐controlled diastereoselective cyclopropanation as additional key steps, the synthetic utility of this novel method has been preliminarily explored by the first and concise total synthesis of the Euphorbia diterpenoid (±)‐pepluanol A.
Alkyltin Keggin Clusters Templated by Sodium
Authors: Saha Sumit , Park Deok‐Hie , Hutchison Danielle C. , Olsen Morgan R. , Zakharov Lev N. , Marsh David , Goberna‐Ferrón Sara , Frederick Ryan T. , Diulus J. Trey , Kenane Nizan , Herman Gregory S. , Johnson Darren W. , Keszler Douglas A. , Nyman May
Published: June 2017

Dodecameric (Sn12) and hexameric topologies dominate monoalkyltin–oxo cluster chemistry. Their condensation, triggered by radiation exposure, recently produced unprecedented patterning performance in EUV lithography. A new cluster topology was crystallized from industrial n‐BuSnOOH, and additional characterization techniques indicate other clusters are present. Single‐crystal X‐ray analysis reveals a β‐Keggin cluster, which is known but less common than other Keggin isomers in polyoxometalate and polyoxocation chemistry. The structure is formulated [NaO4(BuSn)12(OH)3(O)9(OCH3)12(Sn(H2O)2)] (β‐NaSn13). SAXS, NMR, and ESI MS differentiate β‐NaSn13, Sn12, and other clusters present in crude “n‐BuSnOOH” and highlight the role of Na as a template for alkyltin Keggin clusters. Unlike other alkyltin clusters that are cationic, β‐NaSn13 is neutral. Consequently, it stands as a unique model system, absent of counterions, to study the transformation of clusters to films and nanopatterns.
Initiator‐Loaded Gold Nanocages as a Light‐Induced Free‐Radical Generator for Cancer Therapy
Authors: Wang Xiao‐Qiang , Gao Fan , Zhang Xian‐Zheng
Published: June 2017

Tumor hypoxia greatly suppresses the therapeutic efficacy of photodynamic therapy (PDT), mainly because the generation of toxic reactive oxygen species (ROS) in PDT is highly oxygen‐dependent. In contrast to ROS, the generation of oxygen‐irrelevant free radicals is oxygen‐independent. A new therapeutic strategy based on the light‐induced generation of free radicals for cancer therapy is reported. Initiator‐loaded gold nanocages (AuNCs) as the free‐radical generator were synthesized. Under near‐infrared light (NIR) irradiation, the plasmonic heating effect of AuNCs can induce the decomposition of the initiator to generate alkyl radicals (R.), which can elevate oxidative‐stress (OS) and cause DNA damages in cancer cells, and finally lead to apoptotic cell death under different oxygen tensions. As a proof of concept, this research opens up a new field to use various free radicals for cancer therapy.
Synthesis of [5,6]‐Bicyclic Heterocycles with a Ring‐Junction Nitrogen Atom: Rhodium(III)‐Catalyzed C−H Functionalization of Alkenyl Azoles
Authors: Halskov Kim Søholm , Roth Howard S. , Ellman Jonathan A.
Published: June 2017

The first syntheses of privileged [5,6]‐bicyclic heterocycles, with ring‐junction nitrogen atoms, by transition metal catalyzed C−H functionalization of C‐alkenyl azoles is disclosed. Several reactions are applied to alkenyl imidazoles, pyrazoles, and triazoles to provide products with nitrogen incorporated at different sites. Alkyne and diazoketone coupling partners give azolopyridines with various substitution patterns. In addition, 1,4,2‐dioxazolone coupling partners yield azolopyrimidines. Furthermore, the mechanisms for the reactions are discussed and the utility of the developed approach is demonstrated by iterative application of C−H functionalization for the rapid synthesis of a patented drug candidate.
Synthesis and Characterization of a Metallacyclic Framework with Three Fused Five‐membered Rings
Authors: Zhu Congqing , Wu Jingjing , Li Shenyan , Yang Yuhui , Zhu Jun , Lu Xin , Xia Haiping
Published: June 2017

Polycyclic complexes containing a bridgehead transition metal are interesting species because the transition metal is shared by all the rings simultaneously. In this study, we present a novel osmium–bridgehead system with three fused five‐membered rings. This novel framework can be viewed as a 10‐atom carbon chain coordinating to the osmium center. In sharp contrast to the nonplanar organic analogue, this unique metallacycle exhibits good planarity, which was unambiguously verified by means of X‐ray diffraction. Interestingly, preliminary DFT calculations show that the aromaticity in the three 5MRs of these osmatricycles can be easily tuned by the ligand substitution. Finally, the broad UV/Vis absorption spectra of these novel polycyclic complexes were also reported.
1,4‐Diphosphinines from Imidazole‐2‐thiones
Authors: Koner Abhishek , Pfeifer Gregor , Kelemen Zsolt , Schnakenburg Gregor , Nyulászi László , Sasamori Takahiro , Streubel Rainer
Published: June 2017

1,4‐Diphosphinines that are fused to two thiourea units were synthesized from the corresponding tricyclic 1,4‐dichloro‐1,4‐dihydro‐1,4‐diphosphinines, and their structures and spectroscopic features are described. Electrochemical studies revealed very low oxidation potentials, which are due to the effective π‐interaction between the 1,4‐diphosphinine ring and the orbitals of the two ylidic C=S bonds. In accordance with the low‐lying LUMO, which is largely localized at the two phosphorus centers, dianion formation is strongly preferred. Despite the small HOMO–LUMO gap, which is in accordance with the red color of the title compounds, theoretical calculations suggest considerable aromaticity for the 1,4‐diphosphinine ring.
Polytriazole polyether elastomers with widely tunable mechanical properties: The role of network structure and crystallization behavior
Authors: Zou Yecheng , Yang Rongjie , Zhai Jinxian
Published: June 2017

The polytriazole polyether elastomers were prepared by the propargyl‐terminated ethylene oxide‐tetrahydrofuran [PTP(E‐co‐T)] prepolymer and the multi‐azide group glycidyl ether with different curing parameter R. The relationship between the network structure, mechanical properties, and crystallization behaviors of the elastomers were investigated by swelling testing, tensile testing machine, differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WAXD), and in situ wide‐angle X‐ray scattering at 60, 20, and −40 °C, respectively. The mechanical properties of the polytriazole elastomers exhibited obviously different dependences on R values at different testing temperatures. At 60 and 20 °C, with the increase of R, the tensile stress at breaking gives a parabola going downwards with a maximum at R = 1.1. However, at −40 °C, the stress exhibited an analogous parabola going upward with a minimum at R = 1.1. The DSC and WAXD results indicated that at 60 and 20 °C, the polytriazole elastomers was amorphous, but at −40 °C, the polytriazole elastomers were crystallizable and the crystallization capability of the polytriazole elastomers are also observed. Therefore, it can be inferred that at 60 and 20 °C, the mechanical properties of the polyether polytriazole elastomer depend on completeness of the network structures, while the crystallization behavior of the polytriazole elastomers induces its different mechanical properties at −40 °C. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45298.
Single‐ and two‐step procedures of AGET emulsion ATRP of methyl methacrylate in a well‐mixed batch reactor
Authors: Upadhayay Regmi Kishor N. , Mehrvar Mehrab , Dhib Ramdhane
Published: June 2017

This study investigates the atom transfer radical emulsion polymerization of methyl methacrylate in a 2 L well‐mixed stirred batch reactor using activators generated by electron transfer as the initiation technique. The polymerization was carried out with ethyl‐2‐bromoisobutyrate as the initiator, copper bromide with 4,4′‐di‐5‐nonyl‐2,2′‐bipyridine as the catalyst system, Brij 98 as the surfactant, and ascorbic acid as the reducing agent. The reaction was carried out at constant temperature in the range of 50 to 70 °C under a blanket of nitrogen to minimize the presence of air in the system. Polymerizations were carried out according to single‐step and two‐step procedures. The coagulation was found to be a major problem, especially at high monomer conversion. However, adding more surfactant and lowering the reaction temperature weakened the effect of the coagulation but at the expense of the low monomer conversion. Measurement of molecular weight distribution and Đ using gel permeation show that the two‐step techniques produced polymers with living features of atom transfer radical emulsion polymerization much better than those in the single‐step procedure. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45308.
Lignin nanoparticles by ultrasonication and their incorporation in waterborne polymer nanocomposites
Authors: Garcia Gonzalez Maria Nelly , Levi Marinella , Turri Stefano , Griffini Gianmarco
Published: June 2017

Lignin nanoparticles (nanolignin, NL) were prepared in this work by ultrasonic treatment of softwood kraft lignin to obtain lignin‐water dispersions with excellent colloidal stability. A thorough characterization of the chemical, physical, and morphological properties of the new NL particles allowed for direct comparisons with the untreated parent material. Such NL particles were incorporated into a waterborne thermoplastic polyurethane matrix at different concentrations to yield bio‐based nanocomposite materials. The effect of the bio‐filler type (NL vs. untreated lignin) and loading on the chemical, physical, thermal, and morphological characteristics of the resulting nanocomposites was extensively investigated. In addition, tensile tests carried out on these systems highlighted the superior mechanical properties of NL‐based nanocomposites compared to composite materials incorporating untreated lignin. The results of this study provide a direct demonstration of an easy and environmentally friendly approach to obtain waterborne polyurethane‐based nanocomposites reinforced with NL in a relatively straightforward and accessible way and clearly evidence the potential of lignin nanoparticles as fully bioderived fillers for advanced nanocomposite applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45318.
Inducing Thought Processes: Bringing Process Measures and Cognitive Processes Closer Together
Authors: Schulte‐Mecklenbeck Michael , Kühberger Anton , Gagl Benjamin , Hutzler Florian
Published: June 2017

The challenge in inferring cognitive processes from observational data is to correctly align overt behavior with its covert cognitive process. To improve our understanding of this overt–covert mapping in the domain of decision making, we collected eye‐movement data during decisions between gamble‐problems. Participants were either free to choose or instructed to use a specific choice strategy (maximizing expected value or a choice heuristic). We found large differences in looking patterns between free and instructed choices. Looking patterns provided no support for the common assumption that attention is equally distributed between outcomes and probabilities, even when participants were instructed to maximize expected value. Eye‐movement data are to some extent ambiguous with respect to underlying cognitive processes. Copyright © 2017 John Wiley & Sons, Ltd.
Molecular Containers Bind Drugs of Abuse in Vitro and Reverse the Hyperlocomotive Effect of Methamphetamine in Rats
Authors: Ganapati Shweta , Grabitz Stephanie D. , Murkli Steven , Scheffenbichler Flora , Rudolph Maíra I. , Zavalij Peter Y. , Eikermann Matthias , Isaacs Lyle
Published: June 2017

We measured the affinity of five molecular container compounds (calabadions 1 and 2, CB[7], sulfocalix[4]arene, and HP‐β‐CD) toward seven drugs of abuse in homogenous aqueous solution at physiological pH by various methods (1H NMR, UV/Vis, isothermal titration calorimetry [ITC]) and found binding constants (Ka values) spanning from <102 to >108 m−1. We also report X‐ray crystal structures of CB[7]⋅methamphetamine and 1⋅methamphetamine. We found that 2, but not CB[7], was able to ameliorate the hyperlocomotive activity of rats treated with methamphetamine. The bioavailability of the calabadions and their convergent building block synthesis suggest potential for further structural optimization as reversal agents for intoxication with nonopioid drugs of abuse for which no treatments are currently available.
Impact of the Co : Cu Ratio in CoCu‐Containing Oxidic Solids on their Activity for the Water‐Splitting Reaction
Authors: Polyakov Mykola , Surkus Annette‐Enrica , Maljusch Artjom , Hoch Sascha , Martin Andreas
Published: June 2017

Noble metal free bimetallic CoCu‐containing water splitting catalysts for the oxygen evolution reaction (OER) in basic media with different Co : Cu ratios were synthesized. A simple sol‐gel method with citric acid as a multipurpose chelating and reduction agent was used. The subsequent thermal treatment was carried out in an oxygen‐deficient atmosphere (pyrolysis). The catalysts were characterized by rotating disc electrode (RDE) OER measurements, N2 adsorption, XRD, XPS, TEM, DLS and elemental analyses. The highest activity in the OER was achieved with a Co : Cu ratio of 5 (47 A gcatalyst−1 at 1.6 V versus the reversible hydrogen electrode). This is the first time that such high activity has been reported. These transition metal oxide catalysts might be promising candidates as an anode material in alkaline water electrolyzers. Higher and lower Co : Cu ratios revealed less activity.
Electrochemiluminescence Detection in Paper‐Based and Other Inexpensive Microfluidic Devices
Authors: Gross Erin M. , Durant Hannah E. , Hipp Kenneth N. , Lai Rebecca Y.
Published: June 2017

There is a need in the field of microfluidics for integration of analytical detection methods onto small fluidic chips. Electrogenerated chemiluminescence (ECL) is an effective method for detecting a wide range of analytes, including small molecules, metal ions and bacteria. This Minireview discusses recent applications of ECL‐based detection methods to inexpensive microfluidic devices. We discuss various paper and cloth based devices, including 3D‐origami devices and devices utilizing bipolar electrodes. We also discuss novel devices that have replaced traditional instrumentation with inexpensive and portable equipment, such as mobile phones.
Synthesis of Magnetic‐Nanoparticle/Ansamitocin Conjugates—Inductive Heating Leads to Decreased Cell Proliferation In Vitro and Attenuation Of Tumour Growth In Vivo
Authors: Seidel Katja , Balakrishnan Asha , Alexiou Christoph , Janko Christina , Komoll Ronja‐Melinda , Wang Liang‐Liang , Kirschning Andreas , Ott Michael
Published: June 2017

Conjugates based on nanostructured, superparamagnetic particles, a thermolabile linker and a cytotoxic maytansinoid were developed to serve as a model for tumour‐selective drug delivery and release. It combines chemo‐ with thermal therapy. The linker‐modified toxin was prepared by a combination of biotechnology and semisynthesis. Drug release was achieved by hyperthermia through an external oscillating electromagnetic field that induces heat inside the particles. Efficacy of this release concept was demonstrated both for cancer cell proliferation in vitro, and for tumour growth in vivo, in a xenograft mouse model. Biocompatibility studies for these magnetic‐nanoparticle/ansamitocin conjugates complement this work.
Differential neuronal and glial expression of nuclear factor I proteins in the cerebral cortex of adult mice
Authors: Chen Kok‐Siong , Harris Lachlan , Lim Jonathan W. C. , Harvey Tracey J. , Piper Michael , Gronostajski Richard M. , Richards Linda J. , Bunt Jens
Published: June 2017

The nuclear factor I (NFI) family of transcription factors plays an important role in the development of the cerebral cortex in humans and mice. Disruption of nuclear factor IA (NFIA), nuclear factor IB (NFIB), or nuclear factor IX (NFIX) results in abnormal development of the corpus callosum, lateral ventricles, and hippocampus. However, the expression or function of these genes has not been examined in detail in the adult brain, and the cell type‐specific expression of NFIA, NFIB, and NFIX is currently unknown. Here, we demonstrate that the expression of each NFI protein shows a distinct laminar pattern in the adult mouse neocortex and that their cell type‐specific expression differs depending on the family member. NFIA expression was more frequently observed in astrocytes and oligodendroglia, whereas NFIB expression was predominantly localized to astrocytes and neurons. NFIX expression was most commonly observed in neurons. The NFI proteins were equally distributed within microglia, and the ependymal cells lining the ventricles of the brain expressed all three proteins. In the hippocampus, the NFI proteins were expressed during all stages of neural stem cell differentiation in the dentate gyrus, with higher expression intensity in neuroblast cells as compared to quiescent stem cells and mature granule neurons. These findings suggest that the NFI proteins may play distinct roles in cell lineage specification or maintenance, and establish the basis for further investigation of their function in the adult brain and their emerging role in disease.
Centrality in heterogeneous social networks for lurkers detection: An approach based on hypergraphs
Authors: Amato Flora , Moscato Vincenzo , Picariello Antonio , Piccialli Francesco , Sperlí Giancarlo
Published: June 2017

Nowadays, social networks provide users an interactive platform to create and share heterogeneous content for a lot of different purposes (eg, to comment events and facts, and express and share personal opinions on specific topics), allowing millions of individuals to create online profiles and share personal information with vast networks known and sometimes also unknown people. Knowledge about users, content, and relationships in a social network may be used for an adversary attack of some victims easily. Although a number of works have been done for data privacy preservation on relational data, they cannot be applied in social networks and in general for big data analytics. In this paper, we first propose a novel data model that integrates and combines information on users belonging to 1 or more heterogeneous online social networks, together with the content that is generated, shared, and used within the related environments, using an hypergraph data structure; then we implemented the most diffused centrality measures and also introduced a new centrality measure—based on the concept of “neighborhood” among users—that may be efficiently applied for a number of data privacy issues, such as lurkers and neighborhood attack prevention, especially in “interest‐based” social networks. Some experiments using the Yelp dataset are discussed.
Ultrafast Excited‐State Deactivation Dynamics of Cyclotrisazobenzene—A Novel Type of UV‐B Absorber
Authors: Slavov Chavdar , Yang Chong , Schweighauser Luca , Wegner Hermann A. , Dreuw Andreas , Wachtveitl Josef
Published: June 2017

Azobenzenes are widely utilized as molecular photoswitches for control of nanoscale processes. Their photoisomerization reaction is highly robust and is retained even in extremely rigid systems. Currently, it is not clear what geometric restrictions are required to block this isomerization successfully. We present here a combined experimental and theoretical study on the ultrafast dynamics of cyclotrisazobenzene (CTA) and demonstrate that the structural constraints in CTA prevent isomerization of the photoswitch units. In the developed molecular picture, the N=N bonds respond elastically to the motion along the isomerization coordinates, which leads to ultrafast and complete dissipation of the UV excitation as heat. Based on this property, CTA and possibly other similarly designed molecules can be utilized as UV absorbers, for example in sunscreens; other potential applications are also envisioned.
Visible‐Light Photoreduction of CO2 to CH4 over ZnTe‐Modified TiO2 Coral‐Like Nanostructures
Authors: Ehsan Muhammad Fahad , Khan Rabia , He Tao
Published: June 2017

Rapidly depleting fossil fuels and the related environmental issues are two alarming global concerns the world is facing today. To address these issues efficiently, future energy requirements need to be fulfilled by renewable and environmentally friendly resources. In this context, we report the ZnTe‐modified TiO2 photocatalysts with varying amounts of ZnTe (1.96, 16, and 65 %) for the photoreduction of carbon dioxide into methane under visible light. The hydrothermally synthesized photocatalysts have been characterized by using various techniques, such as X‐ray diffraction, scanning electron microscopy coupled with energy‐dispersive X‐ray spectroscopy, transmission electron microscopy, UV/Vis spectroscopy, X‐ray photoelectron spectroscopy and Brunauer–Emmett–Teller (BET) analysis for surface‐area measurements. The photocatalyst with 1.96 % ZnTe shows the best results, which are attributed to its high BET specific surface area and the formation of a heterojunction at the interface, which can facilitate efficient charge transfer.
Computational Insights into the CH3Cl+OH Chemical Reaction Dynamics at the Air–Water Interface
Authors: Martins‐Costa Marilia T. C. , Anglada Josep M. , Ruiz‐López Manuel F.
Published: June 2017

The reaction of methyl chloride with the hydroxyl radical OH is an important process in the troposphere. The kinetics of this reaction has been thoroughly studied in the gas phase, both experimentally and theoretically, but little is known about the effect of water on this reaction. In particular, investigating the reaction mechanism at the air–water interface is key in order to better understand the role of cloud water droplets and aerosols on the overall oxidation capacity of the troposphere. In this work, we have implemented a “rare event” approach combined to QM/MM (quantum mechanics and molecular mechanics) molecular dynamics simulations to investigate the dynamics of the H‐abstraction reaction CH3Cl+OH→CH2Cl+H2O at the air–water interface. For comparison, high‐level ab initio calculations for the reaction mechanism in the gas phase are also reported and accurate kinetic constants at different temperatures are provided.