bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of the peak seismic response of asymmetric buildings under bidirectional horizontal ground motion using equivalentSDOFmodel
Authors: Fujii Kenji
Published: January 2018

The applicability of a simplified procedure, namely mode‐adaptive bidirectional pushover analysis (MABPA), to the prediction of the non‐linear peak response of a multistory asymmetric building subjected to bidirectional excitation is discussed. The first part of the paper summarizes the formulation of 2 independent equivalent single‐degree‐of‐freedom models representing the first and second modal responses. The relationship between the critical assumptions ofMABPAand the torsional index defined based on mode shape is then discussed. In the latter part of the paper, non‐linear time‐history analyses of 4‐story torsionally stiff (TS) or torsionally flexible asymmetric buildings are described, and the results are compared with the predictions. The results show thatMABPApredicts the peak response displacement of only theTSasymmetric buildings satisfactorily. Therefore,MABPAshould be considered applicable only toTSbuildings. The applicability ofMABPAto a given asymmetric building may be evaluated by using the torsional indices of the first 3 modes.
Is seizure frequency variance a predictable quantity?
Authors: Goldenholz Daniel M. , Goldenholz Shira R. , Moss Robert , French Jacqueline , Lowenstein Daniel , Kuzniecky Ruben , Haut Sheryl , Cristofaro Sabrina , Detyniecki Kamil , Hixson John , Karoly Philippa , Cook Mark , Strashny Alex , Theodore William H.
Published: January 2018

Background

There is currently no formal method for predicting the range expected in an individual's seizure counts. Having access to such a prediction would be of benefit for developing more efficient clinical trials, but also for improving clinical care in the outpatient setting.

Methods

Using three independently collected patient diary datasets, we explored the predictability of seizure frequency. Three independent seizure diary databases were explored: SeizureTracker (n = 3016), Human Epilepsy Project (n = 93), and NeuroVista (n = 15). First, the relationship between mean and standard deviation in seizure frequency was assessed. Using that relationship, a prediction for the range of possible seizure frequencies was compared with a traditional prediction scheme commonly used in clinical trials. A validation dataset was obtained from a separate data export of SeizureTracker to further verify the predictions.

Results

A consistent mathematical relationship was observed across datasets. The logarithm of the average seizure count was linearly related to the logarithm of the standard deviation with a high correlation (R2 > 0.83). The three datasets showed high predictive accuracy for this log–log relationship of 94%, compared with a predictive accuracy of 77% for a traditional prediction scheme. The independent validation set showed that the log–log predicted 94% of the correct ranges while the RR50 predicted 77%.

Conclusion

Reliably predicting seizure frequency variability is straightforward based on knowledge of mean seizure frequency, across several datasets. With further study, this may help to increase the power of RCTs, and guide clinical practice.
Cerebrovascular Events in Systemic Lupus Erythematosus: Results From an International Inception Cohort Study
Authors: Hanly John G. , Li Qiuju , Su Li , Urowitz Murray B. , Gordon Caroline , Bae Sang‐Cheol , Romero‐Diaz Juanita , Sanchez‐Guerrero Jorge , Bernatsky Sasha , Clarke Ann E. , Wallace Daniel J. , Isenberg David A. , Rahman Anisur , Merrill Joan T. , Fortin Paul , Gladman Dafna D. , Bruce Ian N. , Petri Michelle , Ginzler Ellen M. , Dooley M. A. , Steinsson Kristjan , Ramsey‐Goldman Rosalind , Zoma Asad A. , Manzi Susan , Nived Ola , Jonsen Andreas , Khamashta Munther A. , Alarcón Graciela S. , Chatham Winn , van Vollenhoven Ronald F. , Aranow Cynthia , Mackay Meggan , Ruiz‐Irastorza Guillermo , Ramos‐Casals Manuel , Lim S. Sam , Inanc Murat , Kalunian Kenneth C. , Jacobsen Soren , Peschken Christine A. , Kamen Diane L. , Askanase Anca , Theriault Chris , Farewell Vernon
Published: January 2018

Objective

To determine the frequency, characteristics, and outcomes of cerebrovascular events (CerVEs), as well as clinical and autoantibody associations in a multiethnic/racial inception cohort of patients with systemic lupus erythematosus (SLE).

Methods

A total of 1,826 patients were assessed annually for 19 neuropsychiatric (NP) events, including 5 types of CerVEs: 1) stroke, 2) transient ischemia, 3) chronic multifocal ischemia, 4) subarachnoid/intracranial hemorrhage, and 5) sinus thrombosis. Global disease activity (Systemic Lupus Erythematosus Disease [SLE] Activity Index 2000), damage scores (SLE International Collaborating Clinics/American College of Rheumatology Damage Index), and Short Form 36 (SF‐36) scores were collected. Time to event, linear and logistic regressions, and multistate models were used as appropriate.

Results

CerVEs were the fourth most frequent NP event: 82 of 1,826 patients had 109 events; of these events, 103 were attributed to SLE, and 44 were identified at the time of enrollment. The predominant events were stroke (60 of 109 patients) and transient ischemia (28 of 109 patients). CerVEs were associated with other NP events attributed to SLE, non–SLE‐attributed NP events, African ancestry (at US SLICC sites), and increased organ damage scores. Lupus anticoagulant increased the risk of first stroke and sinus thrombosis and transient ischemic attack. Physician assessment indicated resolution or improvement in the majority of patients, but patients reported sustained reduction in SF‐36 summary and subscale scores following a CerVE.

Conclusion

CerVEs, the fourth most frequent NP event in SLE, are usually attributable to lupus. In contrast to good physician‐reported outcomes, patients reported a sustained reduction in health‐related quality of life following a CerVE.
Transformation Pathway upon Heating of Ti–Fe Alloys Deformed by High‐Pressure Torsion
Authors: Kriegel Mario J. , Kilmametov Askar , Rudolph Martin , Straumal Boris B. , Gornakova Alena S. , Stöcker Hartmut , Ivanisenko Yulia , Fabrichnaya Olga , Hahn Horst , Rafaja David
Published: January 2018

The current work presents the results of a study of the thermal stability of metastable ω‐Ti(Fe) produced by a high‐pressure torsion process and describes the phase transformations of ω‐Ti(Fe) upon heating. The titanium alloys under study contain between 1 and 7 wt% of iron, the phase transitions are investigated using a combination of in situ high‐temperature X‐ray diffraction and differential scanning calorimetry. The high‐temperature X‐ray diffraction reveals the phase sequence ω → α' → α + β → β upon heating. The differential scanning calorimetry shows that the first phase transformation is exothermal and that the temperature of this phase transition is independent of the iron concentration within the composition range under study. Subsequent phase transitions are endothermal and the respective transition temperatures depend on the iron concentration. The differences between the phase stabilities conclude from the phase diagram and the phase stabilities observe experimentally are explained by the partial coherence of the α/α′‐Ti and β‐Ti grains.
Flexible and Transparent Graphene Electrode Architecture with Selective Defect Decoration for Organic Light‐Emitting Diodes
Authors: Park Ick‐Joon , Kim Tae In , Yoon Taeshik , Kang Sumin , Cho Hyunsu , Cho Nam Sung , Lee Jeong‐Ik , Kim Taek‐Soo , Choi Sung‐Yool
Published: January 2018

Graphene produced by chemical vapor deposition (CVD) has attracted great interest as a transparent conducting material, due to its extraordinary characteristics such as flexibility, optical transparency, and high conductivity, especially in next‐generation displays. Graphene‐based novel electrodes have the potential to satisfy the important factors for high‐performance flexible organic light‐emitting diodes (OLEDs) in terms of sheet resistance, transmittance, work function, and surface roughness. In this study, flexible and transparent graphene electrode architecture is proposed by adopting a selective defect healing technique for CVD‐grown graphene, which results in several benefits that produce high‐performance devices with excellent stabilities. The proposed architecture, which has a multi‐layer graphene structure treated by a layer‐by‐layer healing process, exhibits significant improvement in sheet resistance with high optical transparency. For improving the charge transport property and mechanical robustness, various defect sites of the CVD‐grown graphene are successfully decorated with gold nanoparticles through a simple electroplating (EP) method. Further, a graphene‐based OLED device that integrates the proposed electrode architecture on flexible substrates is demonstrated. Therefore, this architecture provides a new strategy to fabricate graphene electrode in OLEDs, extending graphene's immense potential as an advanced conductor toward high‐performance, flexible, and transparent displays.
Black Phosphorus and Polymeric Carbon Nitride Heterostructure for Photoinduced Molecular Oxygen Activation
Authors: Zheng Yun , Yu Zihao , Ou Honghui , Asiri Abdullah M. , Chen Yilin , Wang Xinchen
Published: January 2018

Metal‐free heterostructure photocatalysts composed of black phosphorus (BP) and polymeric carbon nitride (CN) are successfully synthesized via a one‐step liquid exfoliation method assisted by sonication. The combination of BP with CN strengthens the visible‐light harvesting ability, facilitates the charge separation in the photocatalytic process, and renders promoted activity of photoinduced molecular oxygen activation, such as superoxide radicals (·O2−) evolution and H2O2 production. This work highlights that coupling semiconductors with well‐matched band levels provide a flexible route to enhance the performance of photocatalysts for producing reactive oxygen species, and gives ideas for the design of highly active and metal‐free materials toward sustainable solar‐to‐chemical energy conversion and environmental remediation.
Stamping of Flexible, Coplanar Micro‐Supercapacitors Using MXene Inks
Authors: Zhang Chuanfang (John) , Kremer Matthias P. , Seral‐Ascaso Andrés , Park Sang‐Hoon , McEvoy Niall , Anasori Babak , Gogotsi Yury , Nicolosi Valeria
Published: January 2018

The fast growth of portable smart electronics and internet of things have greatly stimulated the demand for miniaturized energy storage devices. Micro‐supercapacitors (MSCs), which can provide high power density and a long lifetime, are ideal stand‐alone power sources for smart microelectronics. However, relatively few MSCs exhibit both high areal and volumetric capacitance. Here rapid production of flexible MSCs is demonstrated through a scalable, low‐cost stamping strategy. Combining 3D‐printed stamps with arbitrary shapes and 2D titanium carbide or carbonitride inks (Ti3C2Tx and Ti3CNTx, respectively, known as MXenes), flexible all‐MXene MSCs with controlled architectures are produced. The interdigitated Ti3C2Tx MSC exhibits high areal capacitance: 61 mF cm−2 at 25 µA cm−2 and 50 mF cm−2 as the current density increases by 32 fold. The Ti3C2Tx MSCs also showcase capacitive charge storage properties, good cycling lifetime, high energy and power densities, etc. The production of such high‐performance Ti3C2Tx MSCs can be easily scaled up by designing pad or cylindrical stamps, followed by a cold rolling process. Collectively, the rapid, efficient production of flexible all‐MXene MSCs with state‐of‐the‐art performance opens new exciting opportunities for future applications in wearable and portable electronics.
Employing Polar Solvent Controlled Ionization in Precursors for Synthesis of High‐Quality Inorganic Perovskite Nanocrystals at Room Temperature
Authors: Fang Fan , Chen Wei , Li Yang , Liu Haochen , Mei Ming , Zhang Ruan , Hao Junjie , Mikita Marus , Cao Wanqiang , Pan Ruikun , Wang Kai , Sun Xiao Wei
Published: January 2018

All inorganic cesium lead halide (CsPbX3, X = Cl, Br, I) perovskite nanocrystals (PeNCs) are synthesized by employing polar solvent controlled ionization (PCI) method in precursors. The new strategy can be easily carried out at room temperature and allow to employ smaller amount of weaker polarity and a broader range of low‐boiling low‐toxic solvents. The as prepared CsPbX3 PeNCs reveal tunable emission spectra from 380 to 700 nm and high quantum yields over 80% with narrow full width at half maximum (FWHM). Meanwhile, larger “effective Stokes shifts” of PeNCs in PCI method, which enlarges 200% more than other PeNCs in regular methods, are observed. Most interestingly, the PeNCs growth process is coupling with some typical crystals formations. The main morphologies of CsPbI3 PeNCs are hybrid of nanorods and nanoparticles. The primary morphologies of CsPbBrxI3‐x and CsPbBr3 PeNCs are nanowires, which are supposed to have great potentials for applying in laser arrays and highly sensitive photodetector applications. Furthermore, such superior optical is endowed to fabricate white light emitting diodes, which has wide color gamut covering up to 120% of the National Television Systems Committee color standard.
Confining Sulfur in Integrated Composite Scaffold with Highly Porous Carbon Fibers/Vanadium Nitride Arrays for High‐Performance Lithium–Sulfur Batteries
Authors: Zhong Yu , Chao Dongliang , Deng Shengjue , Zhan Jiye , Fang RuYi , Xia Yang , Wang Yadong , Wang Xiuli , Xia Xinhui , Tu Jiangping
Published: January 2018

Increasing the utilization efficiency of sulfur electrodes and suppressing the “shuttle effect” of intermediate polysulfides are the key challenge for high‐performance lithium–sulfur batteries (LSBs). Herein a facile combined strategy is reported to fabricate novel porous carbon fibers/vanadium nitride arrays (PCF/VN) composite scaffold for the storage of sulfur via a facile chemical etching united solvothermal–supercritical fluid method. More active sulfur can be stored in the PCF/VN backbone and dual blocking effects associated with “physical block and chemical absorption” for polysulfides are achieved in the PCF/VN/S integrated electrode. The PCF with highly porous structure provides large space to accommodate active sulfur and possesses cross‐linked maze channels to physically immobilize the polysulfide species. The VN nanobelt arrays demonstrate strong ability for chemically anchoring the polysulfides, thus retarding the shuttle effect. Due to the unique structure and dual confining effect, the designed PCF/VN/S electrode shows a high reversible capacity of 1310.8 mA h g−1 at 0.1 C, an extended cycle life (1052.5 mA h g−1 after 250 cycles) as well as enhanced rate capability, much better than other counterparts (CF/VN/S, PCF/S, and CF/S). This work opens a new door for fabricating high‐performance integrated electrodes for LSBs.
Electron Transfer Directed Antibacterial Properties of Graphene Oxide on Metals
Authors: Panda Sunita , Rout Tapan K. , Prusty Agnish Dev , Ajayan Pulickel M. , Nayak Sasmita
Published: January 2018

Nanomaterials such as silver nanoparticles and graphene‐based composites are known to exhibit biocidal activities. However, interactions with surrounding medium or supporting substrates can significantly influence this activity. Here, it is shown that superior antimicrobial properties of natural shellac‐derived graphene oxide (GO) coatings is obtained on metallic films, such as Zn, Ni, Sn, and steel. It is also found that such activities are directly correlated to the electrical conductivity of the GO‐metal systems; the higher the conductivity the better is the antibacterial activity. GO‐metal substrate interactions serve as an efficient electron sink for the bacterial respiratory pathway, where electrons modify oxygen containing functional groups on GO surfaces to generate reactive oxygen species (ROS). A concerted effect of nonoxidative electron transfer mechanism and consequent ROS mediated oxidative stress to the bacteria result in an enhanced antimicrobial action of naturally derived GO‐metal films. The lack of germicidal effect in exposed cells for GO supported on electrically nonconductive substrates such as glass corroborates the above hypothesis. The results can lead to new GO coated antibacterial metal surfaces important for environmental and biomedical applications.
Tunneling Diode Based on WSe2/SnS2 Heterostructure Incorporating High Detectivity and Responsivity
Authors: Zhou Xing , Hu Xiaozong , Zhou Shasha , Song Hongyue , Zhang Qi , Pi Lejing , Li Liang , Li Huiqiao , Lü Jingtao , Zhai Tianyou
Published: January 2018

van der Waals (vdW) heterostructures based on atomically thin 2D materials have led to a new era in next‐generation optoelectronics due to their tailored energy band alignments and ultrathin morphological features, especially in photodetectors. However, these photodetectors often show an inevitable compromise between photodetectivity and photoresponsivity with one high and the other low. Herein, a highly sensitive WSe2/SnS2 photodiode is constructed on BN thin film by exfoliating each material and manually stacking them. The WSe2/SnS2 vdW heterostructure shows ultralow dark currents resulting from the depletion region at the junction and high direct tunneling current when illuminated, which is confirmed by the energy band structures and electrical characteristics fitted with direct tunneling. Thus, the distinctive WSe2/SnS2 vdW heterostructure exhibits both ultrahigh photodetectivity of 1.29 × 1013 Jones (Iph/Idark ratio of ≈106) and photoresponsivity of 244 A W−1 at a reverse bias under the illumination of 550 nm light (3.77 mW cm−2).
Chemically Responsive Elastomers Exhibiting Unity‐Order Refractive Index Modulation
Authors: Wu Di M. , Solomon Michelle L. , Naik Gururaj V. , García‐Etxarri Aitzol , Lawrence Mark , Salleo Alberto , Dionne Jennifer A.
Published: January 2018

Chameleons are masters of light, expertly changing their color, pattern, and reflectivity in response to their environment. Engineered materials that share this tunability can be transformative, enabling active camouflage, tunable holograms, and novel colorimetric medical sensors. While progress has been made in creating artificial chameleon skin, existing schemes often require external power, are not continuously tunable, and may prove too stiff or bulky for applications. Here, a chemically tunable, large‐area metamaterial is demonstrated that accesses a wide range of colors and refractive indices. An ordered monolayer of nanoresonators is fabricated, then its optical response is dynamically tuned by infiltrating its polymer substrate with solvents. The material shows a strong magnetic response with a dependence on resonator spacing that leads to a highly tunable effective permittivity, permeability, and refractive index spanning negative and positive values. The unity‐order index tuning exceeds that of traditional electro‐optic and photochromic materials and is robust to cycling, providing a path toward programmable optical elements and responsive light routing.
Large‐Area Atomic Layers of the Charge‐Density‐Wave Conductor TiSe2
Authors: Wang Hong , Chen Yu , Duchamp Martial , Zeng Qingsheng , Wang Xuewen , Tsang Siu Hon , Li Hongling , Jing Lin , Yu Ting , Teo Edwin Hang Tong , Liu Zheng
Published: January 2018

Layered transition metal (Ti, Ta, Nb, etc.) dichalcogenides are important prototypes for the study of the collective charge density wave (CDW). Reducing the system dimensionality is expected to lead to novel properties, as exemplified by the discovery of enhanced CDW order in ultrathin TiSe2. However, the syntheses of monolayer and large‐area 2D CDW conductors can currently only be achieved by molecular beam epitaxy under ultrahigh vacuum. This study reports the growth of monolayer crystals and up to 5 × 105 µm2 large films of the typical 2D CDW conductor—TiSe2—by ambient‐pressure chemical vapor deposition. Atomic resolution scanning transmission electron microscopy indicates the as‐grown samples are highly crystalline 1T‐phase TiSe2. Variable‐temperature Raman spectroscopy shows a CDW phase transition temperature of 212.5 K in few layer TiSe2, indicative of high crystal quality. This work not only allows the exploration of many‐body state of TiSe2 in 2D limit but also offers the possibility of utilizing large‐area TiSe2 in ultrathin electronic devices.
Nanoparticle–Cell Interaction: A Cell Mechanics Perspective
Authors: Septiadi Dedy , Crippa Federica , Moore Thomas Lee , Rothen‐Rutishauser Barbara , Petri‐Fink Alke
Published: January 2018

Progress in the field of nanoparticles has enabled the rapid development of multiple products and technologies; however, some nanoparticles can pose both a threat to the environment and human health. To enable their safe implementation, a comprehensive knowledge of nanoparticles and their biological interactions is needed. In vitro and in vivo toxicity tests have been considered the gold standard to evaluate nanoparticle safety, but it is becoming necessary to understand the impact of nanosystems on cell mechanics. Here, the interaction between particles and cells, from the point of view of cell mechanics (i.e., bionanomechanics), is highlighted and put in perspective. Specifically, the ability of intracellular and extracellular nanoparticles to impair cell adhesion, cytoskeletal organization, stiffness, and migration are discussed. Furthermore, the development of cutting‐edge, nanotechnology‐driven tools based on the use of particles allowing the determination of cell mechanics is emphasized. These include traction force microscopy, colloidal probe atomic force microscopy, optical tweezers, magnetic manipulation, and particle tracking microrheology.
Magnetic‐Induced‐Piezopotential Gated MoS2 Field‐Effect Transistor at Room Temperature
Authors: Liu Yudong , Guo Junmeng , Yu Aifang , Zhang Yang , Kou Jinzong , Zhang Ke , Wen Rongmei , Zhang Yan , Zhai Junyi , Wang Zhong Lin
Published: January 2018

Utilizing magnetic field directly modulating/turning the charge carrier transport behavior of field‐effect transistor (FET) at ambient conditions is an enormous challenge in the field of micro–nanoelectronics. Here, a new type of magnetic‐induced‐piezopotential gated field‐effect‐transistor (MIPG‐FET) base on laminate composites is proposed, which consists of Terfenol‐D, a ferroelectric single crystal (PMNPT), and MoS2 flake. When applying an external magnetic field to the MIPG‐FET, the piezopotential of PMNPT triggered by magnetostriction of the Terfenol‐D can serve as the gate voltage to effectively modulate/control the carrier transport process and the corresponding drain current at room temperature. Considering the two polarization states of PMNPT, the drain current is diminished from 9.56 to 2.9 µA in the Pup state under a magnetic field of 33 mT, and increases from 1.41 to 4.93 µA in the Pdown state under a magnetic field of 42 mT and at a drain voltage of 3 V. The current on/off ratios in these states are 330% and 432%, respectively. This work provides a novel noncontact coupling method among magnetism, piezoelectricity, and semiconductor properties, which may have extremely important applications in magnetic sensors, memory and logic devices, micro‐electromechanical systems, and human–machine interfacing.
Highly Efficient Inverted Structural Quantum Dot Solar Cells
Authors: Wang Ruili , Wu Xun , Xu Kaimin , Zhou Wenjia , Shang Yuequn , Tang Haoying , Chen Hao , Ning Zhijun
Published: January 2018

Highly efficient PbS colloidal quantum dot (QD) solar cells based on an inverted structure have been missing for a long time. The bottlenecks are the construction of an effective p–n heterojunction at the illumination side with smooth band alignment and the absence of serious interface carrier recombination. Here, solution‐processed nickel oxide (NiO) as the p‐type layer and lead sulfide (PbS) QDs with iodide ligand as the n‐type layer are explored to build a p–n heterojunction at the illumination side. The large depletion region in the QD layer at the illumination side leads to high photocurrent. Interface carrier recombination at the interface is effectively prohibited by inserting a layer of slightly doped p‐type QDs with 1,2‐ethanedithiol as ligands, leading to improved voltage of the device. Based on this graded device structure design, the efficiency of inverted structural heterojunction PbS QD solar cells is improved to 9.7%, one time higher than the highest efficiency achieved before.
Single Pt Atoms Confined into a Metal–Organic Framework for Efficient Photocatalysis
Authors: Fang Xinzuo , Shang Qichao , Wang Yu , Jiao Long , Yao Tao , Li Yafei , Zhang Qun , Luo Yi , Jiang Hai‐Long
Published: January 2018

It is highly desirable yet remains challenging to improve the dispersion and usage of noble metal cocatalysts, beneficial to charge transfer in photocatalysis. Herein, for the first time, single Pt atoms are successfully confined into a metal–organic framework (MOF), in which electrons transfer from the MOF photosensitizer to the Pt acceptor for hydrogen production by water splitting under visible‐light irradiation. Remarkably, the single Pt atoms exhibit a superb activity, giving a turnover frequency of 35 h−1, ≈30 times that of Pt nanoparticles stabilized by the same MOF. Ultrafast transient absorption spectroscopy further unveils that the single Pt atoms confined into the MOF provide highly efficient electron transfer channels and density functional theory calculations indicate that the introduction of single Pt atoms into the MOF improves the hydrogen binding energy, thus greatly boosting the photocatalytic H2 production activity.
Versatile Indolocarbazole‐Isomer Derivatives as Highly Emissive Emitters and Ideal Hosts for Thermally Activated Delayed Fluorescent OLEDs with Alleviated Efficiency Roll‐Off
Authors: Zhang Dongdong , Song Xiaozeng , Cai Minghan , Kaji Hironori , Duan Lian
Published: January 2018

Maintaining high efficiency at high brightness levels is an exigent challenge for real‐world applications of thermally activated delayed fluorescent organic light‐emitting diodes (TADF‐OLEDs). Here, versatile indolocarbazole‐isomer derivatives are developed as highly emissive emitters and ideal hosts for TADF‐OLEDs to alleviate efficiency roll‐off. It is observed that photophysical and electronic properties of these compounds can be well modulated by varying the indolocarbazole isomers. A photoluminescence quantum yield (ηPL) approaching unity and a maximum external quantum efficiency (EQEmax) of 25.1% are obtained for the emitter with indolo[3,2‐a]carbazolyl subunit. Remarkably, record‐high EQE/power efficiency of 26.2%/69.7 lm W−1 at the brightness level of 5000 cd m−2 with a voltage of only 3.74 V are also obtained using the same isomer as the host in a green TADF‐OLED. It is evident that TADF hosts with high ηPL values, fast reverse intersystem crossing processes, and balanced charge transport properties may open the path toward roll‐off‐free TADF‐OLEDs.
Characterization and Manipulation of Interfacial Activity for Aqueous Galinstan Dispersions
Authors: Koh Amanda , Mrozek Randy , Slipher Geoffrey
Published: January 2018

Room temperature liquid eutectic metals have the potential to maintain electrical and thermal conductivity during deformation, a combination of properties difficult to obtain. Two such metals, eutectic gallium–indium (EGaIn) and galinstan (eutectic gallium–indium–tin), exhibit similar flow behavior attributed to a thin oxide shell. Understanding the oxide shell is critical for understanding the interactions that influence mixing and stability of the liquid metals in other media. In this paper, the effect of aqueous HCl on the interfacial tension (IFT), interfacial rheology, and dispersibility of galinstan are systematically evaluated. It is determined that the IFT of galinstan/water and galinstan/1 m HCl are similar (≈530 mN m−1), but at 0.001 to 0.5 m HCl IFT decreases to 160 mN m−1. Similar discontinuous behavior is observed in the interfacial rheology. The low IFT coupled with a mechanically strong interface at intermediate acid concentrations suggests a change in interface composition. This is supported by SnO2 particles, present during the dispersion process, producing more stable galinstan dispersions than Ga2O3 or In2O3. Interestingly, SnO2 also improves the dispersion of EGaIn despite its lack of tin. This new interfacial manipulation method enables galinstan dispersions in a range of aqueous and nonaqueous phases to enhance the electrical and thermal properties.
Microfluidic Gel Patterning Method by Use of a Temporary Membrane for Organ‐On‐Chip Applications
Authors: Tibbe Martijn P. , Leferink Anne M. , van den Berg Albert , Eijkel Jan C. T. , Segerink Loes I.
Published: January 2018

Organ‐on‐chip systems promise to be useful tools for disease modeling and drug testing. These systems focus on the separation of the parenchymal tissue from endothelial cells, which form the vasculature. Previous organ‐on‐chip models make use of artificial membranes to separate two fluidic channels representing the parenchymal and the endothelial side of native barriers. However, artificial membranes disallow close cell association. During this study, a microfluidic chip, in which a temporary chitosan‐based membrane can be formed, is developed, making direct cell–cell contact between multiple cell types possible. This cell–cell contact on chip can be used to study the behavior of the blood–brain barrier. Chitosan is a polysaccharide that forms a gel‐like solid upon deprotonation. By creating an interface between a basic buffer solution and an acidic chitosan solution, the chitosan gets deprotonated at the interface forming a membrane in the chip. This membrane can be used as a physical barrier for cell culture. 24 h after cell seeding, the temporary membrane of chitosan can be removed by flushing an acidic solution through one of the channels. The membrane fabrication and removal method demonstrated here can be used to create membrane‐free cocultures in a microfluidic device for organs‐on‐chip research.
High‐Performance All‐Aryl Phenazasilines via Metal‐Free Radical‐Mediated CH Silylation for Organic Light‐Emitting Diodes
Authors: Xu Shen , Li Huanhuan , Chen Runfeng , Chen Zhicai , Xu Lijia , Tang Yuting , Huang Wei
Published: January 2018

Heteroatom‐containing organic molecules show a unique combination of properties for high‐performance optoelectronic applications. With both Si and N heteroatoms in an aromatic architecture, phenazasilines are promising for optoelectronic devices, except for their synthetic difficulties. Through a newly developed two‐step SiH/CH coupling silylation in a metal‐free intramolecular radical‐mediated catalysis mechanism, all‐aryl phenazasilines that can be hardly synthesized by previous methods are facilely prepared and found to have excellent optoelectronic properties with both high thermal stability and high solubility due to the effects of bulky diphenyl substituents on Si, which cannot only strengthen the intramolecular interactions but also alleviate the intermolecular packing of phenazasilines. Using these compounds as host materials, high device performance was achieved with external quantum efficiency up to 21.3% and very low efficiency roll‐off (1.4% at 1000 cd m−2), which are among the best of the recent reported results of blue phosphorescent organic light emitting diodes. This design strategy featuring rigid all‐aryl phenazasiline motifs and the metal‐free radical‐catalyzed synthetic methodology should be important in developing high‐performance multiheteroatom modified aromatic molecules for organic optoelectronics.
Characterization of HIF‐1α/Glycolysis Hyperactive Cell Population via Small‐Molecule‐Based Imaging of Mitochondrial Transporter Activity
Authors: Wang Yang , Liao Xingyun , Sun Jianguo , Yi Bin , Luo Shenglin , Liu Tao , Tan Xu , Liu Dengqun , Chen Zelin , Wang Xin , Shi Chunmeng
Published: January 2018

The characterization of cancer stem‐like cells (CSCs) has profound implications for elucidating cancer biology and developing treatment strategies. Although surface markers are already used to identify CSCs, the expression of these markers is controversially linked to the phenotypes in different types of tumors and does not represent all functionally relevant of CSCs. Very recently, hyperactive HIF‐1α/glycolysis metabolic pathway is recognized as a master regulator of CSCs. In this study, a near‐infrared fluorescent small‐molecule, IR‐780, is identified for the exclusive characterization of human CSCs through the HIF‐1α/glycolysis dependent mitochondrial transporter ABCB10's activity. The results identified for the first time that ABCB10 is involved in the preferential uptake of IR‐780 in CSCs, which is regulated by HIF‐1α via the direct interaction with the binding site of ABCB10 gene promoter region. In addition, IR‐780 is demonstrated to conjugate with anticancer drug 5‐fluorouracil to act as a potential drug delivery carrier for CSC‐targeted therapy. Thus, the studies provide a new rational approach independent of surface markers to characterize CSCs via small‐molecule‐based imaging of HIF‐1α/glycolysis hyperactive metabolic pathway dependent mitochondrial transporter's activity, which holds promise for the further development of CSCs targeted diagnostic and therapeutic strategies.
Enhanced Ion Conductivity in Conducting Polymer Binder for High‐Performance Silicon Anodes in Advanced Lithium‐Ion Batteries
Authors: Zeng Wenwu , Wang Lei , Peng Xiang , Liu Tiefeng , Jiang Youyu , Qin Fei , Hu Lin , Chu Paul K. , Huo Kaifu , Zhou Yinhua
Published: January 2018

Polymer binders with high ion and electron conductivities are prepared by assembling ionic polymers (polyethylene oxide and polyethylenimine) onto the electrically conducting polymer poly(3,4‐ethylenedioxythiophene): poly(styrenesulfonate) chains. Crosslinking, chemical reductions, and electrostatics increase the modulus of the binders and maintain the integrity of the anode. The polymer binder shows lithium‐ion diffusivity and electron conductivity that are 14 and 90 times higher than those of the widely used carboxymethyl cellulose (with acetylene black) binder, respectively. The silicon anode with the polymer binder has a high reversible capacity of over 2000 mA h g−1 after 500 cycles at a current density of 1.0 A g−1 and maintains a superior capacity of 1500 mA h g−1 at a high current density of 8.0 A g−1.
Manganese‐Catalyzed C−H Cyanation of Arenes with N‐Cyano‐N‐(4‐methoxy)phenyl‐p‐toluenesulfonamide
Authors: Yu Xiaoqiang , Tang Jingjing , Jin Xinxin , Yamamoto Yoshinori , Bao Ming
Published: January 2018

A manganese‐catalyzed C−H cyanation reaction of arenes has been developed using N‐cyano‐N‐(4‐methoxy)phenyl‐p‐toluenesulfonamide as the cyanating agent. The reaction proceeds smoothly with high regioselectivity to provide monocyanated products in satisfactory yields.
Metal‐Free Azidoarylation of Vinylcyclopropanes for the Synthesis of N3‐Containing Dihydronaphthalenes
Authors: Li Zong‐Rui , Wu Dun‐Qi , Sun Jian , Shen Jing , Deng Qing‐Hai
Published: January 2018

An efficient methodology for the direct metal‐free azidoarylation of vinylcyclopropanes using trimethylsilyl azide as the N3‐transfer reagent is described. The reaction can be performed on a gram scale and a series of N3‐containing dihydronaphthalene derivatives (20 examples) were prepared in good to high yields under mild reaction conditions. Furthermore, three of these organic azides were selected for facile conversion into the corresponding 1,2,3‐triazoles or amino derivatives.
Lewis‐Acid‐Catalyzed Activation of Zerumbone towards Sesquiterpenoid Derivatives: Sustainable Utilization of Abundant Natural Resources for the Synthesis of Chemically Diverse Architectures
Authors: Dhanya Bhandara Purayil , Gopalan Greeshma , Sasikumar Parameswaran , Neethu Sivadas , Meenu Murugan Thulasi , Sharathna Puthiyaparambath , John Jubi , Varughese Sunil , Sabu Mamiyil , Dan Mathew , Radhakrishnan Kokkuvayil Vasu
Published: January 2018

A facile Lewis‐acid‐catalyzed method for the synthesis of structurally diverse sesquiterpenoid derivatives from readily available and abundant 11‐membered natural product zerumbone has been developed. Starting from zerumbone, we have developed an efficient cyclization process for the creation of [5.7], [5.8], and [5.8.3] fused‐ring systems. This process was exemplified by the selective functionalization of zerumbone; by controlling the conformation of the 11‐membered ring, the ring‐closing process could be tuned to afford the fused‐ring system of choice.
Submucosal gland mucus strand velocity is decreased in chronic rhinosinusitis
Authors: Tipirneni Kiranya E. , Zhang Shaoyan , Cho Do‐Yeon , Grayson Jessica , Skinner Daniel F. , Mackey Calvin , Moore Lindsay , Cole Denzel , Banks Catherine G. , Woodworth Bradford A.
Published: January 2018

Background

Chronic rhinosinusitis (CRS) may be initiated by innately impaired host defense mechanisms that predispose the upper airways to infection. Recent evidence suggests tethering of submucosal gland mucus strands represents an inciting event within cystic fibrosis (CF) airways, occurring prior to onset of chronic infection. Submucosal gland hypertrophy and defective mucociliary clearance (MCC) are present in actively inflamed sinuses, but mucus strand velocity may also be affected as a secondary event, further contributing to chronic disease. The objective of this study is to assess whether mucus strand velocity is decreased in patients with CRS.

Methods

Mucosal explants from patients with and without CRS were submerged in Ringer's solution mixed with fluorescent nanospheres. Methacholine was then added, and videos demonstrating strand growth and detachment were generated from a time‐lapse of Z‐stack images using a multiphoton confocal microscope. Dynamic mucus strands were identified and individual velocities quantified with the MTrackJ plug‐in of ImageJ.

Results

Fifteen patients met criteria for ex vivo analysis of mucus strand velocities (CRS, n = 9 vs controls, n = 6). Mucus strands were recorded (pixels/second) streaming from the submucosal gland openings. Average mucus strand velocities were significantly decreased in patients with CRS (1.53 ± 0.67 vs controls, 4.86 ± 1.68 pixels/second; p < 0.001).

Conclusion

This study is the first to report evidence of abnormal mucus strand velocity from submucosal glands in diseased sinonasal mucosa. Future pharmacologic studies targeting this critical component of MCC are warranted.
Interconversion of Molybdenum Imido and Amido Complexes by Proton‐Coupled Electron Transfer
Authors: Bezdek Máté J. , Chirik Paul J.
Published: January 2018

Interconversion of the molybdenum amido [(PhTpy)(PPh2Me)2Mo(NHtBuAr)][BArF24] (PhTpy=4′‐Ph‐2,2′,6′,2“‐terpyridine; tBuAr=4‐tert‐butyl‐C6H4; ArF24=(C6H3‐3,5‐(CF3)2)4) and imido [(PhTpy)(PPh2Me)2Mo(NtBuAr)][BArF24] complexes has been accomplished by proton‐coupled electron transfer. The 2,4,6‐tri‐tert‐butylphenoxyl radical was used as an oxidant and the non‐classical ammine complex [(PhTpy)(PPh2Me)2Mo(NH3)][BArF24] as the reductant. The N−H bond dissociation free energy (BDFE) of the amido N−H bond formed and cleaved in the sequence was experimentally bracketed between 45.8 and 52.3 kcal mol−1, in agreement with a DFT‐computed value of 48 kcal mol−1. The N−H BDFE in combination with electrochemical data eliminate proton transfer as the first step in the N−H bond‐forming sequence and favor initial electron transfer or concerted pathways.
Asymmetric Catalytic Preparation of Polysubstituted Cyclopropanol and Cyclopropylamine Derivatives
Authors: Simaan Marwan , Marek Ilan
Published: January 2018

The catalytic asymmetric carbometalation of cyclopropenes followed by either an electrophilic oxidation or amination reaction provides a unique approach to the formation of diastereomerically pure and enantiomerically enriched cyclopropanol and cyclopropylamine derivatives, respectively.
Barbier–Negishi Coupling of Secondary Alkyl Bromides with Aryl and Alkenyl Triflates and Nonaflates
Authors: Zhang Ke‐Feng , Christoffel Fadri , Baudoin Olivier
Published: January 2018

A mild and practical Barbier–Negishi coupling of secondary alkyl bromides with aryl and alkenyl triflates and nonaflates has been developed. This challenging reaction was enabled by the use of a very bulky imidazole‐based phosphine ligand, which resulted in good yields as well as good chemo‐ and site selectivities for a broad range of substrates at room temperature and under non‐aqueous conditions. This reaction was extended to primary alkyl bromides by using an analogous pyrazole‐based ligand.
Molecular‐Barrier‐Enhanced Aromatic Fluorophores in Cocrystals with Unity Quantum Efficiency
Authors: Ye Huanqing , Liu Guangfeng , Liu Sheng , Casanova David , Ye Xin , Tao Xutang , Zhang Qichun , Xiong Qihua
Published: January 2018

Singlet–triplet conversion in organic light‐emitting materials introduces non‐emissive (dark) and long‐lived triplet states, which represents a significant challenge in constraining the optical properties. There have been considerable attempts at separating singlets and triplets in long‐chain polymers, scavenging triplets, and quenching triplets with heavy metals; nonetheless, such triplet‐induced loss cannot be fully eliminated. Herein, a new strategy of crafting a periodic molecular barrier into the π‐conjugated matrices of organic aromatic fluorophores is reported. The molecular barriers effectively block the singlet‐to‐triplet pathway, resulting in near‐unity photoluminescence quantum efficiency (PLQE) of the organic fluorophores. The transient optical spectroscopy measurements confirm the absence of the triplet absorption. These studies provide a general approach to preventing the formation of dark triplet states in organic semiconductors and bring new opportunities for the development of advanced organic optics and photonics.
Enantioselective Polyene Cyclization Catalyzed by a Chiral Brønsted Acid
Authors: Fan Liwen , Han Chunyu , Li Xuerong , Yao Jiasheng , Wang Zhengning , Yao Chaochao , Chen Weihao , Wang Tao , Zhao Junfeng
Published: January 2018

The first enantioselective polyene cyclization initiated by a BINOL‐derived chiral N‐phosphoramide (NPA) catalyzed protonation of an imine is described. The ion‐pair formed between the iminium ion and chiral counter anion of the NPA plays an important role for controlling the stereochemistry of the overall transformation. This strategy offers a highly efficient approach to fused tricyclic frameworks containing three contiguous stereocenters, which are widely found in natural products. In addition, the first catalytic asymmetric total synthesis of (−)‐ferruginol was accomplished with an NPA catalyzed enantioselective polyene cyclization, as the key step for the construction of the tricyclic core, with excellent yield and enantioselectivity.
Disilenyl Silylene Reactivity of a Cyclotrisilene
Authors: Zhao Hui , Leszczyńska Kinga , Klemmer Lukas , Huch Volker , Zimmer Michael , Scheschkewitz David
Published: January 2018

The highly reactive silicon congeners of cyclopropene, cyclotrisilenes (c‐Si3R4), typically undergo either π‐addition to the Si=Si double bond or σ‐insertion into the Si−Si single bond. In contrast, treatment of c‐Si3Tip4 (Tip=2,4,6‐iPr3C6H2) with styrene and benzil results in ring opening of the three‐membered ring to formally yield the [1+2]‐ and [1+4] cycloaddition product of the isomeric disilenyl silylene to the C=C bond and the 1,2‐diketone π system, respectively. At elevated temperature, styrene is released from the [1+2]‐addition product leading to the thermodynamically favored housane species after [2+2] cycloaddition of styrene and c‐Si3Tip4.
Stable trans isomer as the kinetic and theromodynamic product for the oxidative addition of MeI to cycloplatinated(II) complexes comprising isocyanide ligands
Authors: Shahsavari Hamid R. , Aghakhanpour Reza Babadi , Hossein‐Abadi Mojdeh , Kia Reza , Raithby Paul R.
Published: January 2018

The present investigation introduces a new series of cycloplatinated(II) complexes, with the general formula Pt(O‐bpy)(Me)(CN‐R)] (R = benzyl, 2‐naphtyl and tert‐butyl), which are able to generate the stable trans‐Pt(IV) product in the solution after the reaction with iodomethane. In fact, the trans product is both the kinetic and thermodynamic product of the reaction; this observation was supported by DFT calculations. These Pt(II) complexes are supported by 2,2'‐bipyridine N‐oxide (O‐bpy) and one of several isocyanides as the cyclometalated and ancillary ligands, respectively. These new Pt(II) complexes undergo oxidative addition with MeI to give the corresponding trans‐Pt(IV) complexes. All the complexes were identified employing the multi‐nuclear NMR spectroscopy and single crystal X‐ray crystallography. The kinetic investigations were also performed for the oxidative addition reactions in order to measure the reaction rates; the reaction was followed by UV‐Vis spectroscopy. The rates obtained follow the trend CN‐tBu > CN‐Bz > CN‐2 Np for the CN‐R ligands in the Pt(II) complexes. The order can be related to the degree of electron‐donation of the R group (tert‐butyl > benzyl > 2‐naphtyl).
Nitrogen‐doped graphene as an alternative to ecotoxic zinc oxide in rubbers
Authors: Glebova Yulia , Severin Nikolai , Shershnev Vladimir , Rabe Jürgen P.
Published: January 2018

Zinc oxide (ZnO) is an essential ingredient in industrial rubber production; it regulates the onset of vulcanization, accelerates the kinetics of vulcanization, and improves the mechanical properties of rubber. However, environmental pollution with ZnO is a concern because it is recognized to be significantly ecotoxic and might also have adverse effects on human health. One of the major sources of ZnO environmental pollution is rubber items, tires in particular. Nitrogen (N)‐doped graphene is a promising next‐generation catalyst. We show here that the replacement of 3 phr ZnO by just 0.1 phr N‐doped graphene in styrene–butadiene rubber reduced the vulcanization onset time by more than a factor of two while retaining the fast vulcanization kinetics and enhancing the tensile strength in comparison with rubber with just ZnO. A shorter vulcanization time implies energy savings, which, together with the nontoxicity of N‐graphene, should make the resulting rubbers substantially more environmentally friendly. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46116.
Reconstruction of molecular network evolution from cross‐sectional omics data
Authors: Aflakparast Mehran , de Gunst Mathisca C. M. , van Wieringen Wessel N.
Published: January 2018

Cross‐sectional studies may shed light on the evolution of a disease like cancer through the comparison of patient traits among disease stages. This problem is especially challenging when a gene–gene interaction network needs to be reconstructed from omics data, and, in addition, the patients of each stage need not form a homogeneous group. Here, the problem is operationalized as the estimation of stage‐wise mixtures of Gaussian graphical models (GGMs) from high‐dimensional data. These mixtures are fitted by a (fused) ridge penalized EM algorithm. The fused ridge penalty shrinks GGMs of contiguous stages. The (fused) ridge penalty parameters are chosen through cross‐validation. The proposed estimation procedures are shown to be consistent and their performance in other respects is studied in simulation. The down‐stream exploitation of the fitted GGMs is outlined. In a data illustration the methodology is employed to identify gene–gene interaction network changes in the transition from normal to cancer prostate tissue.