bluuebunny/crossref_metadata_2025 huggingface dataset:
Room‐Temperature Nonvolatile Memory Based on a Single‐Phase Multiferroic Hexaferrite
Authors: Zhai Kun , Shang Da‐Shan , Chai Yi‐Sheng , Li Gang , Cai Jian‐Wang , Shen Bao‐Gen , Sun Young
Published: December 2017

The cross‐coupling between electric polarization and magnetization in multiferroic materials provides a great potential for creating next‐generation memory devices. Current studies on magnetoelectric (ME) applications mainly focus on ferromagnetic/ferroelectric heterostructures because single‐phase multiferroics with strong magnetoelectric coupling at room temperature are still very rare. Here a type of nonvolatile memory device is presented solely based on a single‐phase multiferroic hexaferrite Sr3Co2Fe24O41 which exhibits nonlinear magnetoelectric effects at room temperature. The principle is to store binary information by employing the states (magnitude and sign) of the first‐order and the second‐order magnetoelectric coefficients (α and β), instead of using magnetization, electric polarization, and resistance. The experiments demonstrate repeatable nonvolatile switch of α and β by applying pulsed electric fields at room temperature, respectively. Such kind of memory device using single‐phase multiferroics paves a pathway toward practical applications of spin‐driven multiferroics.
Passivated Perovskite Crystallization via g‐C3N4 for High‐Performance Solar Cells
Authors: Jiang Lu‐Lu , Wang Zhao‐Kui , Li Meng , Zhang Cong‐Cong , Ye Qing‐Qing , Hu Ke‐Hao , Lu Ding‐Ze , Fang Peng‐Fei , Liao Liang‐Sheng
Published: December 2017

Organometallic halide perovskite films with good surface morphology and large grain size are desirable for obtaining high‐performance photovoltaic devices. However, defects and related trap sites are generated inevitably at grain boundaries and on surfaces of solution‐processed polycrystalline perovskite films. Seeking facial and efficient methods to passivate the perovskite film for minimizing defect density is necessary for further improving the photovoltaic performance. Here, a convenient strategy is developed to improve perovskite crystallization by incorporating a 2D polymeric material of graphitic carbon nitride (g‐C3N4) into the perovskite layer. The addition of g‐C3N4 results in improved crystalline quality of perovskite film with large grain size by retarding the crystallization rate, and reduced intrinsic defect density by passivating charge recombination centers around the grain boundaries. In addition, g‐C3N4 doping increases the film conductivity of perovskite layer, which is beneficial for charge transport in perovskite light‐absorption layer. Consequently, a champion device with a maximum power conversion efficiency of 19.49% is approached owing to a remarkable improvement in fill factor from 0.65 to 0.74. This finding demonstrates a simple method to passivate the perovskite film by controlling the crystallization and reducing the defect density.
Engineering of Self‐Propelling Microbots and Microdevices Powered by Magnetic and Electric Fields
Authors: Han Koohee , Shields C. Wyatt , Velev Orlin D.
Published: December 2017

In the last two decades, advances in micro‐ and nanofabrication have enabled the development of a wide variety of active or “self‐propelling” microparticles, which convert energy from their environment into directed motion. While these autonomous entities have shown promise for efficient locomotion on the microscale, their practical utility remains unrealized due to their inability to perform multiple useful tasks on demand. From an engineering perspective, the active particle behavior can be encoded on an individual level by tailoring key design elements such as shape, polarizability, surface pattern, and bulk functionality. This feature article focusses on active particles powered by electric and magnetic fields, as these sources of energy allow the particles to: (1) move in several phenomenologically unique ways, (2) respond in a reliable manner to the field parameters, and (3) interact synergistically to enable multiple functions. It is hypothesized how future generations of such particles may remotely harvest and transduce energy to perform several useful tasks such as biosensing and delivering drugs. As a step toward realizing such particles, several new types of active particles are demonstrated. Finally, a perspective on the future directions of this emerging field is provided by discussing current challenges, potential applications as well as future opportunities.
Electron Field Emission of Geometrically Modulated Monolayer Semiconductors
Authors: Yang Tung‐Han , Chiu Kuan‐Chang , Harn Yeu‐Wei , Chen Han‐Yi , Cai Ren‐Fong , Shyue Jing‐Jong , Lo Shen‐Chuan , Wu Jenn‐Ming , Lee Yi‐Hsien
Published: December 2017

Electron field emission, electrons emitted from solid surfaces under high electric field, offers significant scientific interests in materials sciences and potential optoelectronics applications. 2D atomic layers, such as MoS2, exhibit fascinating properties for diverse applications in next‐generation nanodevices and rich physical phenomena for fundamental research. However, the study on field emission of semiconducting monolayers is lacking owing to its low efficiency and stability of electron emission. Here, electron field emission of the geometrically modulated monolayer semiconductors suspended with 1D nanoarrays is demonstrated. Chemical vapor deposition synthesis of two prototype monolayers of transition metal dichalcogenides (TMD), MoS2 and MoSe2, is presented and their diverse band structures offer an ideal platform to explore the fundamental process of the electron emission in the TMD. Geometrical modulation and charge transfer of the semiconducting monolayers can be significantly tuned with the structural suspension with the 1D ZnO nanoarrays. Possible mechanisms on the enhanced electron emission of the 2D monolayers are discussed. With geometrical control of the monolayers, a highly efficient and stable electron emission of TMD monolayers is achieved in low turn‐on electric fields, enabling applications on electrons sources and opening a new avenue toward geometrically tuned atomic layers.
A Mechanoresponsive Phase‐Changing Electrolyte Enables Fabrication of High‐Output Solid‐State Photobioelectrochemical Devices from Pigment‐Protein Multilayers
Authors: Ravi Sai Kishore , Swainsbury David J. K. , Singh Varun Kumar , Ngeow Yoke Keng , Jones Michael R. , Tan Swee Ching
Published: December 2017

Exploitation of natural photovoltaic reaction center pigment proteins in biohybrid architectures for solar energy harvesting is attractive due to their global abundance, environmental compatibility, and near‐unity quantum efficiencies. However, it is challenging to achieve high photocurrents in a device setup due to limitations imposed by low light absorbance by protein monolayers and/or slow long‐range diffusion of liquid‐phase charge carriers. In an attempt to enhance the photocurrent density achievable by pigment proteins, here, an alternative solid‐state device architecture enabled by a mechanoresponsive gel electrolyte that can be applied under nondenaturing conditions is demonstrated. The phase‐changing electrolyte gel provides a pervading biocompatible interface for charge conduction through highly absorbing protein multilayers that are fabricated in a simple fashion. Assembled devices exhibit enhanced current stability and a maximal photoresponse of ≈860 µA cm−2, a fivefold improvement over the best previous comparable devices under standard illumination conditions. Photocurrent generation is enhanced by directional energy transfer through extended layers of light‐harvesting complexes, mimicking the modular antenna/transducer architecture of natural photosystems, and by metastable radical pair formation when photovoltaic reaction centers are embedded throughout light‐harvesting regions of the device.
Artificial Muscles: Mechanisms, Applications, and Challenges
Authors: Mirvakili Seyed M. , Hunter Ian W.
Published: December 2017

The area of artificial muscle is a highly interdisciplinary field of research that has evolved rapidly in the last 30 years. Recent advances in nanomaterial fabrication and characterization, specifically carbon nanotubes and nanowires, have had major contributions in the development of artificial muscles. However, what can artificial muscles really do for humans? This question is considered here by first examining nature's solutions to this design problem and then discussing the structure, actuation mechanism, applications, and limitations of recently developed artificial muscles, including highly oriented semicrystalline polymer fibers; nanocomposite actuators; twisted nanofiber yarns; thermally activated shape‐memory alloys; ionic‐polymer/metal composites; dielectric‐elastomer actuators; conducting polymers; stimuli‐responsive gels; piezoelectric, electrostrictive, magnetostrictive, and photostrictive actuators; photoexcited actuators; electrostatic actuators; and pneumatic actuators.
The Self‐Assembly of Cellulose Nanocrystals: Hierarchical Design of Visual Appearance
Authors: Parker Richard M. , Guidetti Giulia , Williams Cyan A. , Zhao Tianheng , Narkevicius Aurimas , Vignolini Silvia , Frka‐Petesic Bruno
Published: December 2017

By controlling the interaction of biological building blocks at the nanoscale, natural photonic nanostructures have been optimized to produce intense coloration. Inspired by such biological nanostructures, the possibility to design the visual appearance of a material by guiding the hierarchical self‐assembly of its constituent components, ideally using natural materials, is an attractive route for rationally designed, sustainable manufacturing. Within the large variety of biological building blocks, cellulose nanocrystals are one of the most promising biosourced materials, primarily for their abundance, biocompatibility, and ability to readily organize into photonic structures. Here, the mechanisms underlying the formation of iridescent, vividly colored materials from colloidal liquid crystal suspensions of cellulose nanocrystals are reviewed and recent advances in structural control over the hierarchical assembly process are reported as a toolbox for the design of sophisticated optical materials.
Continuous‐Wave Lasing in Cesium Lead Bromide Perovskite Nanowires
Authors: Evans Tyler J. S. , Schlaus Andrew , Fu Yongping , Zhong Xinjue , Atallah Timothy L. , Spencer Michael S. , Brus Louis E. , Jin Song , Zhu X.‐Y.
Published: December 2017

Lead halide perovskite nanowires (NWs) have been demonstrated in pulsed lasing with high quantum yields, low thresholds, and broad tunability. However, continuous‐wave (CW) lasing, necessary for many optoelectronic applications, has not been achieved to date. This is thought to be due to many‐body screening, which reduces the excitonic resonance enhancement of the oscillator strength at high excitation densities necessary for population inversion. Here CW lasing in CsPbBr3 perovskite NWs is reported. Analysis of the cavity modes and their temperature dependence reveals that both CW and pulsed lasing originate from polariton modes near the bottleneck region on the lower polariton branch, with a vacuum Rabi splitting of 0.20 ± 0.03 eV. These findings suggest that lead halide perovskite NWs may serve as low‐power CW coherent light sources and as model systems for polaritonics in the strong‐coupling regime.
Boosting the Photoluminescence of Monolayer MoS2 on High‐Density Nanodimer Arrays with Sub‐10 nm Gap
Authors: Hao Qi , Pang Jinbo , Zhang Yang , Wang Jiawei , Ma Libo , Schmidt Oliver G.
Published: December 2017

Patterned plasmonic nanodimers are fabricated exploiting an ultrathin porous anodic aluminum oxide membrane as a mask during angle‐resolved shadow deposition. The fabricated nanodimer arrays exhibit consistent sub‐10 nm gaps and a high particle density up to 1.0 × 1010 cm−2 over a large area. The ultrasmall dimer gaps provide highly confined electromagnetic fields, which strongly enhance the photoluminescence (PL) emission and Raman scattering from the surrounding monolayer molybdenum disulphide (MoS2). The ensemble PL intensity from MoS2/dimers is enhanced by up to a factor of ≈160 by resonant excitation of the dimer modes. Anisotropic polarization‐dependent characteristics of PL and Raman from the MoS2/dimers confirm that the dominant enhancement originates from the dimer configuration. These experiments demonstrate a facile approach for the fabrication of low‐cost high‐performance 2D material‐based optoelectronic devices.
High Density and Super Ultra‐Microporous‐Activated Carbon Macrospheres with High Volumetric Capacity for CO2 Capture
Authors: Liu Jingjing , Liu Xin , Sun Yuan , Sun Chenggong , Liu Hao , Stevens Lee A. , Li Kaixi , Snape Colin E.
Published: December 2017

Activated carbon (AC) spheres with a diameter of 1.0–2.0 mm are synthesized from coal tar pitch for postcombustion carbon capture. The as‐prepared AC macrospheres after potassium hydroxide (KOH) activation are found to possess extraordinarily developed microporosity of which 87% is ultra‐microporosity with pore diameters less than 0.8 nm. Despite the relatively low surface area of just 714 m2 g−1 with a pore volume of 0.285 cm3 g−1, the macrospherical carbon adsorbents achieve exceedingly high CO2 uptake capacities of 3.15 and 1.86 mmol g−1 at 0 and 25 °C, respectively, with a CO2 partial pressure of 0.15 bar. Cyclic lifetime performance testing demonstrates that the CO2 uptake is fully reversible with fast adsorption and desorption kinetics. More importantly, due to their high bulk density of ≈1.0 g cm−3, the AC macrospheres exhibit extremely high volumetric CO2 uptakes of up to 81.8 g L−1 at 25 °C at 0.15 bar CO2, which represents the highest value ever reported for ACs. The high ultra‐microporosity coupled with the potassium‐modified physiochemical surface properties is found to be responsible for the outstanding CO2 adsorption performance of the pitch‐based AC macrospheres.
Improved interfacial properties of carbon fiber composites by building stress transition layer with carbon nanotubes
Authors: Zhang Wenqing , Yang Qing , Deng Xi , Bai Gang , Xiao Wei , Sui Gang , Yang Xiaoping
Published: December 2017

For the purpose of improvement in interfacial property of carbon fiber composites through a facile process, the carboxyl‐functionalized multiwalled carbon nanotubes (MWCNTs‐COOH) were incorporated into the surface of JH‐T800 carbon fiber using sizing and deposition technology. The surface morphology of MWCNTs‐COOH‐modified carbon fibers and fracture surfaces of unidirectional carbon fiber composites were observed via scanning electron microscopy and atomic force microscopy. According to the results of composites fragmentation test, the adoption of MWCNTs‐COOH‐modified carbon fibers resulted in the improved carbon fiber/epoxy matrix interfacial bonding and interlaminer property by 32.1% and 31.9%, respectively. Through the combination of the above two kinds of pretreating process of carbon fibers, a stress transition layer with the gradient distribution of MWCNTs was built between carbon fiber and resin matrix, which was favorable for releasing stress concentration and hindering the propagation of crack, resulting in a higher reinforcing efficiency for the existing carbon fiber composites.
Voltage Losses in Organic Solar Cells: Understanding the Contributions of Intramolecular Vibrations to Nonradiative Recombinations
Authors: Chen Xian‐Kai , Brédas Jean‐Luc
Published: December 2017

The large voltage losses usually encountered in organic solar cells significantly limit the power conversion efficiencies (PCEs) of these devices, with the result that the current highest PCE values in single‐junction organic photovoltaic remain smaller than for other solar cell technologies, such as crystalline silicon or perovskite solar cells. In particular, the nonradiative recombinations to the electronic ground state from the lowest‐energy charge‐transfer (CT) states at the donor–acceptor interfaces in the active layer of organic devices, are responsible for a significant part of the voltage losses. Here, to better comprehend the nonradiative voltage loss mechanisms, a fully quantum‐mechanical rate formula is employed within the framework of time‐dependent perturbation theory, combined with density functional theory. The objective is to uncover the specific contributions of intramolecular vibrations to the CT‐state nonradiative recombinations in several model systems, which include small‐molecule and polymer donors as well as fullerene and nonfullerene acceptors.
Optimized Concentration of Redox Mediator and Surface Protection of Li Metal for Maintenance of High Energy Efficiency in Li–O2 Batteries
Authors: Kwak Won‐Jin , Park Seong‐Jin , Jung Hun‐Gi , Sun Yang‐Kook
Published: December 2017

Recently, various approaches for adding redox mediators to electrolytes and introducing protective layers onto Li metal have been suggested to overcome the low energy efficiency and poor cycle life of Li–O2 batteries. However, the catalytic effect of the redox mediator for oxygen evolution gradually deteriorates during repeated cycling owing to its decomposition at the surfaces of both the oxygen electrode (cathode) and the Li metal electrode (anode). Here, optimized Li–O2 batteries are designed with a continuously effective redox mediator and a stable protective layer for the Li metal electrode by optimizing the LiBr concentration and introducing a graphene–polydopamine composite layer, respectively. These synergistic modifications lead to a reduction of the charge potential to below 3.4 V and significantly improve the stability and cycle life of Li–O2 batteries. Consequently, a high energy efficiency of above 80% is maintained over 150 cycles. Herein, it is confirmed that the relationships between all the battery materials should be understood in order to improve the performance of Li–O2 batteries.
Achieving zT > 2 in p‐Type AgSbTe2−xSex Alloys via Exploring the Extra Light Valence Band and Introducing Dense Stacking Faults
Authors: Hong Min , Chen Zhi‐Gang , Yang Lei , Liao Zhi‐Ming , Zou Yi‐Chao , Chen Yan‐Hui , Matsumura Syo , Zou Jin
Published: December 2017

Through simultaneously enhancing the power factor by engineering the extra light band and enhancing phonon scatterings by introducing a high density of stacking faults, a record figure‐of‐merit over 2.0 is achieved in p‐type AgSbTe2−xSex alloys. Density functional theory calculations confirm the presence of the light valence band with large degeneracy in AgSbTe2, and that alloying with Se decreases the energy offset between the light valence band and the valence band maximum. Therefore, a significantly enhanced power factor is realized in p‐type AgSbTe2−xSex alloys. In addition, transmission electron microscopy studies indicate the appearance of stacking faults and grain boundaries, which together with grain boundaries and point defects significantly strengthen phonon scatterings, leading to an ultralow thermal conductivity. The synergetic strategy of simultaneously enhancing power factor and strengthening phonon scattering developed in this study opens up a robust pathway to tailor thermoelectric performance.
A Soft and Robust Spring Based Triboelectric Nanogenerator for Harvesting Arbitrary Directional Vibration Energy and Self‐Powered Vibration Sensing
Authors: Xu Minyi , Wang Peihong , Wang Yi‐Cheng , Zhang Steven L. , Wang Aurelia Chi , Zhang Chunli , Wang Zhengjun , Pan Xinxiang , Wang Zhong Lin
Published: December 2017

Vibration is a common mechanical phenomenon and possesses mechanical energy in ambient environment, which can serve as a sustainable source of power for equipment and devices if it can be effectively collected. In the present work, a novel soft and robust triboelectric nanogenerator (TENG) made of a silicone rubber‐spring helical structure with nanocomposite‐based elastomeric electrodes is proposed. Such a spring based TENG (S‐TENG) structure operates in the contact‐separation mode upon vibrating and can effectively convert mechanical energy from ambient excitation into electrical energy. The two fundamental vibration modes resulting from the vertical and horizontal excitation are analyzed theoretically, numerically, and experimentally. Under the resonant states of the S‐TENG, its peak power density is found to be 240 and 45 mW m−2 with an external load of 10 MΩ and an acceleration amplitude of 23 m s−2. Additionally, the dependence of the S‐TENG's output signal on the ambient excitation can be used as a prime self‐powered active vibration sensor that can be applied to monitor the acceleration and frequency of the ambient excitation. Therefore, the newly designed S‐TENG has a great potential in harvesting arbitrary directional vibration energy and serving as a self‐powered vibration sensor.
Using Geospatial Research Methods to Examine Resource Accessibility and Availability as it Relates to Community Participation of Individuals with Serious Mental Illnesses
Authors: Townley Greg , Brusilovskiy Eugene , Snethen Gretchen , Salzer Mark S.
Published: December 2017

Greater community participation among individuals with serious mental illnesses is associated with better psychosocial and health outcomes. Typically, studies examining community participation have utilized self‐report measures and been conducted in limited settings. The introduction of methodological advances to examining community participation of individuals with serious mental illnesses has the potential to advance the science of community mental health research and invigorate the work of community psychologists in this area. This study employed an innovative geospatial approach to examine the relationship between community participation and resource accessibility (i.e., proximity) and availability (i.e., concentration) among 294 individuals utilizing community mental health services throughout the United States. Findings suggest small but significant associations between community participation and the accessibility and availability of resources needed for participation. Furthermore, findings demonstrate the importance of car access for individuals residing in both urban and non‐urban settings. The methods and results presented in this study have implications for community mental health research and services and provide an illustration of ways that geospatial methodologies can be used to investigate environmental factors that impact community inclusion and participation of individuals with serious mental illnesses.
Understanding Systems Change in Early Implementation of Housing First in Canadian Communities: An Examination of Facilitators/Barriers, Training/Technical Assistance, and Points of Leverage
Authors: Worton S. Kathleen , Hasford Julian , Macnaughton Eric , Nelson Geoffrey , MacLeod Timothy , Tsemberis Sam , Stergiopoulos Vicky , Goering Paula , Aubry Tim , Distasio Jino , Richter Tim
Published: December 2017

We present interim findings of a cross‐site case study of an initiative to expand Housing First (HF) in Canada through training and technical assistance (TTA). HF is an evidence‐based practice designed to end chronic homelessness for consumers of mental health services. We draw upon concepts from implementation science and systems change theory to examine how early implementation occurs within a system. Case studies examining HF early implementation were conducted in six Canadian communities receiving HF TTA. The primary data are field notes gathered over 1.5 years and evaluations from site‐specific training events (k = 5, n = 302) and regional network training events (k = 4, n = 276). We report findings related to: (a) the facilitators of and barriers to early implementation, (b) the influence of TTA on early implementation, and (c) the “levers” used to facilitate broader systems change. Systems change theory enabled us to understand how various “levers” created opportunities for change within the communities, including establishing system boundaries, understanding how systems components can function as causes of or solutions to a problem, and assessing and changing systems interactions. We conclude by arguing that systems theory adds value to existing implementation science frameworks and can be helpful in future research on the implementation of evidence‐based practices such as HF which is a complex community intervention. Implications for community psychology are discussed.
Injury, illness, and disability risk in American seafarers
Authors: Lefkowitz Rafael Y. , Slade Martin D. , Redlich Carrie A.
Published: December 2017

Background

Seafarers are an understudied and essential workforce, isolated from medical care. This study describes injuries, illness, and risk factors for resultant disability in one shipping company with a majority of American seafarers.

Methods

The study used a telemedicine database of injury and illness incidence in seafarers, and applied descriptive statistical methods and logistic regression modeling.

Results

Illnesses were more frequently reported than injuries (860 vs 479). The overall injury rate was 113 per 1000 person‐years, and the overall illness rate was 211 per 1000 person‐years. Seafarer ratings had higher risk for disability compared to officers (OR = 1.60; 95%CI 1.17, 2.18), and incidents on dry cargo ships (OR = 2.70; 95%CI 1.49, 4.91) and articulated tug‐barges (ATBs) (OR = 2.21; 95%CI 1.26, 3.86) had higher disability risk compared to container vessels.

Conclusion

Additional research in this vital American workforce may be useful to confirm these findings forming a basis for preventive interventions.
Longitudinal interplays of estrogen receptor alpha gene rs9340799 with social‐environmental factors on post‐traumatic stress disorder in Chinese Han adolescents after Wenchuan earthquake
Authors: Feng Yue , Su Mi , Si Yan Jun , Guo Qi Wei , Lin Jia , Cao Ting , Zhang Xin , Fan Mei , Fang Ding Zhi
Published: December 2017

Indirect evidences suggested associations of estrogen receptor alpha (ESR1) with post‐traumatic stress disorder (PTSD). However, the relationship between rs9340799 on ESR1 gene and PTSD has not been reported yet. The present study was to explore the longitudinal changes of prevalence and severity of PTSD in adolescents with different genotypes of rs9340799 after the 2008 Wenchuan earthquake. Social‐environmental factors were collected by questionnaires in 465 high school students. Variants of rs9340799 were determined by polymerase chain reaction‐restriction fragment length polymorphism analyses and verified by DNA sequencing. PTSD symptoms were assessed by PTSD Checklist‐Civilian Version (PCL‐C) at 6, 12, and 18 months after the earthquake. The female AA homozygotes had a trend of higher prevalence of PTSD and significantly higher PCL‐C scores than the female G allele carriers at 6 months after the earthquake. The female students had higher prevalence of PTSD and higher PCL‐C scores than the male subjects at 6 months in the AA homozygotes, but not in the G allele carriers. Consecutive decreases in PCL‐C scores were observed only in the female AA homozygotes. Only in the female, the AA genotype was the risk factor and predictor of PCL‐C scores at 6 months. Potential factors of PTSD prevalence and predictors of PCL‐C scores were different between the AA homozygotes and G allele carriers at different time during the follow‐up. These results suggest gene‐environment interactions may occur among rs9340799 and social‐environmental factors, and influence the development and natural rehabilitation of PTSD in the course after stressed by the earthquake.
Peripheral Templation‐Modulated Interconversion between an A4L6 Tetrahedral Anion Cage and A2L3 Triple Helicate with Guest Capture/Release
Authors: Bai Xuemin , Jia Chuandong , Zhao Yanxia , Yang Dong , Wang Shi‐Cheng , Li Anyang , Chan Yi‐Tsu , Wang Yao‐Yu , Yang Xiao‐Juan , Wu Biao
Published: December 2017

An anion‐coordination‐based A4L6 (“A” denotes anion and “L” is ligand) tetrahedral cage was constructed by a C2‐symmetric bis‐bis(urea) ligand and phosphate anion, which showed reversible interconversion with the A2L3 triple helicate as a response to the template, concentration, or solvent. Notably, an unusual “peripheral” templation was found to be critical to stabilize the tetrahedral structure. This peripheral effect was utilized to assemble an “empty” A4L6 cage that allows the multi‐stimuli‐controlled capture/release of biologically important species such as choline and acetylcholine.
Direct Annulation between Aryl Iodides and Epoxides through Palladium/Norbornene Cooperative Catalysis
Authors: Li Renhe , Dong Guangbin
Published: December 2017

Herein we report a direct annulation between aryl iodides and epoxides through palladium/norbornene (Pd/NBE) cooperative catalysis. An iso‐propyl ester substituted NBE was found to be most efficient to suppress the formation of multiple‐NBE‐insertion byproducts and affords the desired 2,3‐dihydrobenzofuran derivatives in 44–99 % yields. The reaction is scalable and tolerates a range of functional groups. Asymmetric synthesis is realized using an enantiopure epoxide. Application of this method into a concise synthesis of insecticide fufenozide is demonstrated.
Separation of Linear and Branched Alkanes Using Host–Guest Complexation of Cyclic and Branched Alkane Vapors by Crystal State Pillar[6]arene
Authors: Ogoshi Tomoki , Saito Kazuki , Sueto Ryuta , Kojima Ryosuke , Hamada Yukie , Akine Shigehisa , Moeljadi Adhitya Mangala Putra , Hirao Hajime , Kakuta Takahiro , Yamagishi Tada‐aki
Published: December 2017

Activated crystals of pillar[6]arene produced by removing the solvent upon heating were able to take up branched and cyclic alkane vapors as a consequence of their gate‐opening behavior. The uptake of branched and cyclic alkane vapors by the activated crystals of pillar[6]arene induced a crystal transformation to form one‐dimensional channel structures. However, the activated crystals of pillar[6]arene hardly took up linear alkane vapors because the cavity size of pillar[6]arene is too large to form stable complexes with linear alkanes. This shape‐selective uptake behavior of pillar[6]arene was further utilized for improving the research octane number of an alkane mixture of isooctane and n‐heptane: interestingly, the research octane number was dramatically improved from a low research octane number (17 %) to a high research octane number (>99 %) using the activated crystals of pillar[6]arene.
Crystal structure of meso‐substituted pyrazolyl porphyrin complexes and their highly active catalyst for oxidation of alkylbenzenes
Authors: Yao Yahong , Du Yanxia , Li Jun , Wang Chen , Zhang Zengqi , Zhao Xin
Published: December 2017

During the past few years, a great deal of effort has been devoted to the anchoring of catalytic oxidation. In this work, three new catalysts CuPp, MnPp and ZnPp by solvothermal methods with 5, 10, 15, 20‐tetrakis(4‐N‐pyrazolyl)‐phenyl porphyrin (H2Pp) and the corresponding metal salts have been synthesized and structurally characterized. The single crystal structures determined by X‐ray diffraction show the bond distances of M‐N in porphyrin cores determined the conformation of porphyrin rings. We explored the catalytic activity of CoPp, CuPp, MnPp and ZnPp for oxidation of alkylbenzenes. The experimental results display these products exhibit high catalytic activities and selectivities for oxidation of ethylbenzene to acetophenone, and can be reused by filtration without appreciable decrease in catalytic activity and selectivity.
Novel strategy for molybdenum disulfide nanosheets grown on titanate nanotubes for enhancing the flame retardancy and smoke suppression of epoxy resin
Authors: Li Aijiao , Xu Wenzong , Wang Guisong , Wang Xiaoling
Published: December 2017

A novel hybrid consisting of a molybdenum disulfide (MoS2) coating on a titanium dioxide nanotube (TNT) surface (MoS2–TNT) was synthesized by a hydrothermal method. The MoS2, TNTs, and MoS2–TNT hybrid were incorporated into epoxy resin (EP) to study their effects on its thermal performance and flame retardancy. Thermogravimetric analysis results show that the char yield at 700 °C of EP–MoS2–TNTs was obviously increased compared with that of the EP–MoS2 or EP–TNTs; this indicated that MoS2–TNTs had a good carbonization effect. The limiting oxygen index, cone calorimetry, and smoke density tests showed that MoS2–TNTs effectively improved the flame retardancy and smoke suppression of EP. This was attributed to the physical barrier effect of MoS2 and the adsorption of TNTs. Moreover, the flame retardancy and smoke suppression of the EP–MoS2–TNTs were better than those of the EP–MoS2 or EP–TNTs alone with the same amount of addition; this indicated that there was a synergistic effect between MoS2 and TNTs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46064.
The effect of mass transfer resistance and nonuniform initial solvent concentration on permeation through polymer membranes
Authors: Zielinski John M. , Alsoy Altinkaya Sacide
Published: December 2017

A numerical simulation model has been developed which enables one to examine the effects of surface mass transfer resistance on the evaluation of permeation (P*), diffusion (D), and solubility (S) coefficients from unsteady‐state mass transfer experiments as well as the transmission rate. A complementary analytical expression has been developed which validates the numerical model and facilitates the evaluation of the concentration dependence of P*, D, and S from sequential step‐change experiments, under experimental conditions when the surface mass transfer resistance can be neglected. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46126.
Zeolite filled siloxane composite foams: Compression property
Authors: Calabrese Luigi , Bonaccorsi Lucio , Bruzzaniti Paolo , Gullì Giuseppe , Freni Angelo , Proverbio Edoardo
Published: December 2017

In this article, mechanical behavior under compression loads of an innovative adsorbent material, based on silicone composite foams filled with SAPO 34 zeolite, is presented. The innovative composite foams were obtained profiting by the dehydrogenative coupling of siloxane constituents. These new adsorbent systems have been proposed to overcome to the low mechanical stability of conventional SAPO‐34 coating for adsorption chiller. In this concern, static and cyclic compressive tests at room temperature have been carried out. Samples at increasing content of SAPO 34 zeolite were tested to evaluate the influence of the filler content on the mechanical behavior of the composite foam. The results showed that the presence of zeolite reduces the elastic limit of the foam and increases the strength. The foams evidenced also acceptable mechanical stability to cyclic compressive loads. The encouraging results confirm the possible use of these new composite foams as adsorbent materials for cyclic adsorption heat pumps. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46145.
Toward green three‐phase composites with enhanced dielectric permittivity
Authors: Zyane Adel , Brouillette François , Belfkira Ahmed , Lucas Romain , Marchet Pascal
Published: December 2017

This work aims to investigate the dielectric potential of microcrystalline cellulose, a green biosourced material, as a third constituent in the three‐phase composites based on ethylene vinyl acetate‐vinyl ester of versatic acid (EVA‐VeoVa) terpolymer and BaTiO3. For that, new green three‐phase composites were prepared using an economic and green process, with simple implementation at room temperature and using water as a solvent. Compared with the binary composite EVA‐VeoVa/BaTiO3, the three‐phase composite EVA‐VeoVa/BaTiO3/microcrystalline cellulose showed an improvement of the BaTiO3 particles dispersion, enhanced relative permittivity, and reduced dielectric loss, which explains the significance of this study. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46147.
Synthesis and elastase inhibition activities of novel aryl, substituted aryl, and heteroaryl oxime ester derivatives
Authors: Hasdemir Belma , Sacan Ozlem , Yasa Hasniye , Kucuk Hatice B. , Yusufoglu Ayse S. , Yanardag Refiye
Published: December 2017

Fifteen novel aryl, substituted aryl and heteroaryl γ‐hydroxy‐ (2a–e), γ‐methoxyimino‐ (3a–e), and γ‐benzyloxyimino‐ (4a–e) butyric acid methyl esters were investigated for their enzyme inhibition, and the synthesis of 10 compounds (3a–e, 4a–e) is given in this study. The other five compounds (2a–e) were synthesized before in another study. Compounds 3a–e and 4a–e were synthesized in this work as original compounds and characterized by 1H and 13C NMR, IR, mass, and elemental analyses. Their (E/Z)‐isomerisation ratios were analyzed by 1H and 13C NMR. All of them are of pure (E)‐configuration. Due to the literature survey, the elastase inhibition activity was not studied for these compounds. Elastase inhibition ability was investigated in this work for five γ‐hydroxy‐ (2a–e), five γ‐methoxy‐ (3a–e), and five γ‐benzyloxyimino‐ (4a–e) butyric acid methyl esters. All these 15 compounds showed elastase inhibition activity. Compound 2b was the best one and exhibited a better activity than the standard ursolic acid whereas compound 2a worked like the standard. All these compounds can be novel elastase inhibitor agents in the pharmaceutical and cosmetic industries.
Impact and educational outcomes of a small group self‐directed teaching strategy in a clinical neuroscience curriculum
Authors: Nathaniel Thomas I. , Gainey Jordan C. , Williams Jessica A. , Stewart Bianca L. , Hood Michael C. , Brechtel Leanne E. , Faulkner Rakiya V. , Pendergrass Jasmine S. , Black Leigh‐Ann , Griffin Scott K. , Troup Christopher E. , Reuben Jayne S. , Black Asa C.
Published: December 2017

The complexity of the material being taught in clinical neuroscience within the medical school curriculum requires creative pedagogies to teach medical students effectively. Many clinical teaching strategies have been developed and are well described to address these challenges. However, only a few have been evaluated to determine their impact on the performance of students studying clinical neuroscience. Interactive, 2‐hour, self‐directed small‐group interactive clinical case‐based learning sessions were conducted weekly for 4 weeks to integrate concepts learned in the corresponding didactic lectures. Students in the small groups analyzed cases of patients suffering from neurological disease that were based on eight learning objectives that allowed them to evaluate neuroanatomical data and clinical findings before presenting their case analysis to the larger group. Students’ performances on the formative quizzes and summative tests were compared to those of first‐year medical students in the previous year for whom the self‐directed, small‐group interactive clinical sessions were not available. There was a significant improvement in the summative performance of first‐year medical students with self‐directed clinical case learning in the second year (Y2) of teaching clinical neuroscience (P < 0.05) when compared with first‐year students in the first year (Y1) for whom the self‐directed learning approach was not available. Student performance in the formative assessments between Y1 and Y2 was not significantly different (P = 0.803). A target of ≥70% student scoring above 80% in the final summative examination was met. The current study revealed evidence for the impact and educational outcomes of a self‐directed, clinical teaching strategy in a clinical neuroscience curriculum for first‐year medical students. Anat Sci Educ 11: 478–487. © 2017 American Association of Anatomists.
Patterns of altered neural synchrony in the default mode network in autism spectrum disorder revealed with magnetoencephalography (MEG): Relationship to clinical symptomatology
Authors: Lajiness‐O'Neill Renée , Brennan Jonathan R. , Moran John E. , Richard Annette E. , Flores Ana‐Mercedes , Swick Casey , Goodcase Ryan , Andersen Tiffany , McFarlane Kaitlyn , Rusiniak Kenneth , Kovelman Ioulia , Wagley Neelima , Ugolini Maggie , Albright Jeremy , Bowyer Susan M
Published: December 2017

Disrupted neural synchrony may be a primary electrophysiological abnormality in autism spectrum disorders (ASD), altering communication between discrete brain regions and contributing to abnormalities in patterns of connectivity within identified neural networks. Studies exploring brain dynamics to comprehensively characterize and link connectivity to large‐scale cortical networks and clinical symptoms are lagging considerably. Patterns of neural coherence within the Default Mode Network (DMN) and Salience Network (SN) during resting state were investigated in 12 children with ASD (MAge = 9.2) and 13 age and gender‐matched neurotypicals (NT) (MAge = 9.3) with magnetoencephalography. Coherence between 231 brain region pairs within four frequency bands (theta (4–7 Hz), alpha, (8–12 Hz), beta (13–30 Hz), and gamma (30–80 Hz)) was calculated. Relationships between neural coherence and social functioning were examined. ASD was characterized by lower synchronization across all frequencies, reaching clinical significance in the gamma band. Lower gamma synchrony between fronto‐temporo‐parietal regions was observed, partially consistent with diminished default mode network (DMN) connectivity. Lower gamma coherence in ASD was evident in cross‐hemispheric connections between: angular with inferior/middle frontal; middle temporal with middle/inferior frontal; and within right‐hemispheric connections between angular, middle temporal, and inferior/middle frontal cortices. Lower gamma coherence between left angular and left superior frontal, right inferior/middle frontal, and right precuneus and between right angular and inferior/middle frontal cortices was related to lower social/social‐communication functioning. Results suggest a pattern of lower gamma band coherence in a subset of regions within the DMN in ASD (angular and middle temporal cortical areas) related to lower social/social‐communicative functioning.Autism Res2018, 11: 434–449. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

Lay Summary

Communication between different areas of the brain was observed in children with ASD and neurotypical children while awake, but not working on a task. Magnetoencephalography was used to measure tiny magnetic fields naturally generated via brain activity. The brains of children with ASD showed less communication between areas that are important for social information processing compared to the brains of neurotypical children. The amount of communication between these areas was associated with social and social communication difficulties.
Rückbau von Spannbeton‐Talbrücken mit Vorschubgerüst
Authors: Däbritz Michael , Mertinaschk André
Published: December 2017

Die mitteleuropäische Fernstraßeninfrastruktur der 1960er‐ und 1970er‐Jahre ist geprägt durch eine zunehmende Überbeanspruchung. Instandsetzungsmaßnahmen an diesen Bauwerken ermöglichen die weitere Nutzung häufig nur für einen begrenzten Zeitraum. Rückbau und Ersatzneubau erfordern insbesondere in ökologisch sensiblen Bereichen und solchen mit hoher Dichte an kreuzenden Verkehrswegen Sorgfalt bei der Auswahl eines Rückbausystems, welches zudem sicherstellt, dass Unterbrechungen des Verkehrs auf der betroffenen Strecke während der Baumaßnahmen auf ein Minimum beschränkt werden.

Der Rückbau von Talbrücken mit Vorschubgerüst stellt einen geeigneten Lösungsansatz dar, welcher den Anforderungen an die Bauwerke und die Verkehrssicherheit gerecht wird. Der Artikel beschreibt Einsatzbedingungen für das Rückbauverfahren, die Funktionsweise und die Unterscheidung zum bekannten Neubau mit Vorschubgerüsten. Im Vergleich zu Neubauvorhaben muss im Grundsatz von höheren Belastungen ausgegangen werden, von einer Unschärfe zu erwartender Lasten aus dem Bestandsbauwerk und von zusätzlichen am Projekt beteiligten Gewerken wie dem Abbruchunternehmen. Anhand bisher durchgeführter Projekte werden Anforderungen an Planung, Montage und Robustheit der Konstruktion beschrieben sowie Schnittstellen zu anderen Projektbeteiligten berührt, die vor und während des Rückbauvorhabens in teilweise größerem Maße zu berücksichtigen sind als beim Neubau.
Engineering tunable biosensors for monitoring putrescine in Escherichia coli
Authors: Chen Xue‐Feng , Xia Xiao‐Xia , Lee Sang Yup , Qian Zhi‐Gang
Published: December 2017

Biosensors can be a powerful tool for real‐time monitoring of specific small molecules and for precise control of gene expression in biological systems. Thus, biosensors have attracted much attention for monitoring increasing number of molecules. However, strategies to tune the properties of biosensors remain less explored, which might restrict their wide applicability. Here we report the development of tunable biosensors for monitoring putrescine, an important member of biological polyamines, in Escherichia coli. The native putrescine‐responsive PuuR repressor protein was employed as a sensing component, and its cognate operator was installed in engineered promoters to control the expression of downstream green fluorescent protein (GFP) mut3 as a reporter protein. The engineered biosensors were specific for putrescine, and the response time could be modulated by altering growth medium of the biosensor strains. In addition, the response dynamics and detection ranges of the biosensors can be tuned at the genetic level by modulation of PuuR expression, and by manipulation of the chromosomal genes involved in putrescine biosynthesis. To demonstrate utility of the biosensors, we were able to monitor the changes of endogenous putrescine levels caused by genetic manipulations. Furthermore, a link between the excretory putrescine titer and intracellular GFP fluorescence was established for an E. coli strain that was engineered for improved putrescine biosynthesis and excretion. This study provides a strategy for engineering synthetic biosensor circuit for monitoring and tuning the dynamics in sensing putrescine, which can be generally applicable for monitoring other chemicals through taking a similar approach in circuit design.
HPLC‐MS/MS analysis of anthocyanins in human plasma and urine using protein precipitation and dilute‐and‐shoot sample preparation methods, respectively
Authors: Liu Junguo , Song Jiuxue , Huang Karen , Michel Deborah , Fang Jim
Published: December 2017

A high‐performance liquid chromatography tandem–mass spectrometry (HPLC‐MS/MS) method has been developed to analyze anthocyanins in urine and plasma to further understand their absorption, distribution, metabolism and excretion. The method employed a Synergi RP‐Max column (250 × 4.6 mm, 4 μm) and an API 4000 mass spectrometer. A gradient elution system consisted of mobile phase A (water–1% formic acid) and mobile phase B (acetonitrile) with a flow rate of 0.60 mL/min. The gradient was initiated at 5% B, increased to 21% B at 20 min, and then increased to 40% B at 35 min. The analysis of anthocyanins presents a challenge because of the poor stability of anthocyanins during sample preparation, especially during solvent evaporation. In this method, the degradation of anthocyanins was minimized using protein precipitation and dilute‐and‐shoot and sample preparation methods for plasma and urine, respectively. No interferences were observed from endogenous compounds. The method has been used to analyze anthocyanin concentrations in urine and plasma samples from volunteers administered saskatoon berries. Cyanidin‐3‐galactoside, cyanidin‐3‐glucoside, cyanidin‐3‐arabinoside, cyanidin‐3‐xyloside and quercetin‐3‐galactoside, the five major flavonoid components in saskatoon berries, were identified in plasma and urine samples.