bluuebunny/crossref_metadata_2025 huggingface dataset:
Using question and answer and story telling for unlocking creative potential in undergraduate research student
Authors: Ng Wenfa
Published: January 2018

The final year research project, a standard feature of most four year undergraduate curricula, aims to introduce undergraduates to scientific research as well as encourage them to think creatively and critically about problems from different perspectives. However, most courses in earlier parts of the curriculum focus on well defined problems with clear answers; thus, a huge gap exists between a research project’s desired educational outcomes and the students’ educational preparation. As a result, students experience significant difficulties in handling ambiguities (i.e., no defined answers) inherent in research - which, in turn, leads to lack of motivation or trepidation at their projects. Is the above due to students’ lack of creativity? Or does it have more to do with the difficulty of sparking students’ imagination, the reason on which lies in the lack of pedagogical techniques available. Postgraduates are the primary daily point of contact for undergraduates in the research lab; for example, during demonstration of experimental techniques or discussion of new observations. But how can postgraduates encourage undergraduates to think critically and creatively? One possibility is in using common lab observations and experiences to unlock students’ creative potential. In this abstract only preprint, I describe two simple pedagogical tools for helping initiate creative and critical thinking processes in students. Specifically, the Socratic approach of question and answer, used in guiding students to answer their own questions rather than having answers provided to them, helped ignite, in the students, deductive and inductive thinking processes critical to tackling any research problem. This also helps increase students’ self confidence in problem solving. More importantly, the tentative steps taken in independent thinking also helped debunk their misconception that there exists a single correct answer for every research question. Another pedagogical tool used was constructing narratives (unrelated to their subject matter) based on seemingly mundane electron and optical micrographs. For example, an electron micrograph of a collection of particles polydispersed in size and shape was entitled, “Pebbles on the river bed”, with a storyline describing children playing happily in a clear stream and, upon looking down, saw small gravel and pebbles on the stream bed. Besides bringing a light hearted moment into serious research work, such narratives also illustrated the utility of thinking about a problem from multiple angles; specifically, discovering new and creative interpretations of an image. Collectively, through simple pedagogical tools such as question and answer, and open ended story telling, postgraduates can demonstrate the thinking process involved in exploring different perspectives during problem solving, and hence, guide undergraduate students in thinking critically and creatively.
Towards extracellular secretion of poly-β-hydroxybutyric acid (PHB) biodegradable polymer
Authors: Ng Wenfa
Published: January 2018

Plastics’ poor biodegradablility, bioaccumulation and biomagnification potential, and emission of hazardous chemicals during incineration, pose challenging disposal problems. Biodegradable, bio-renewable and biocompatible bacterial lipid-based storage polymer, poly-β-hydroxybutyric acids (PHB), offers a good functional replacement for petroleum-derived plastics. Originally nature’s solution for helping bacteria moderate fluctuations in nutrient availability, progressive understanding of PHB biosynthetic pathway guided efforts aimed at overproducing the polymer via genetic engineering methods, or optimizing fermentation conditions and growth medium composition. Although increasing PHB production titer improves efficiency and reduces cost, the high price and lack of competitiveness of PHB in the consumer market stems largely from intracellular accumulation of PHB - where extraction and purification is the most significant cost component of PHB production. Additionally, use of toxic solvents and surfactants during PHB extraction may also contaminate the product. Thus, compared with increasing production titer, eliminating the extraction step would go further in reducing PHB’s relative price (cost), and improves production sustainability; thereby, motivating the development of techniques for inducing the secretion of PHB. Given society’s goal of mitigating climate change through reducing dependence on petroleum-derived chemicals, extracellular secretion of PHB would also help realize a bio-feedstock based chemical industry – where secreted PHB serves as precursors for synthesizing a range of platform chemicals. By tuning the size of PHB inclusion bodies and targeting them to appropriate cellular exporters through genetic engineering, recent research has described the creation of a recombinant Escherichia coli strain capable of secreting substantial fraction of size-limited PHB granules. Possible routes for increasing the amount of extracellularly exported PHB include: engineering PHB granules suitable for extracellular export, exploring and creating alternative export pathways and transporters through targeted genetic engineering and/or directed evolution, and creating “leaky” bacterial strains for facile PHB secretion. Overall, achieving progress on one or more of the above challenges would help advance PHB’s role in a bio-renewable chemical industry. Additional topics such as the utility of PHB as bacterial storage polymers; the genes and metabolic pathways mediating its synthesis; and fermentation and extraction methods enabling its production provide context for a holistic discussion on the evolutionary origins, contemporary rediscovery and production of this incredibly useful and versatile biopolymer.
Walking down computational chemistry memory lane one acronym at a time
Authors: Ng Wenfa
Published: January 2018

History is often thought to be dull and boring – where large numbers of facts are memorized for passing exams. But the past informs both the present and future; particularly in delineating the context surrounding specific events that, in turn, help provide us with a deeper understanding of their underlying causes and potential implications. To the uninitiated, the computational chemistry literature appears intimating given the pervasive use of acronyms (each with specialist meaning) and eponymous method names. While jargons expedite communication of complex ideas between practitioners in the field, and add clarity to a discussion (e.g., explaining complicated concepts in plain language may not capture subtle - but important - nuances in meaning), they nevertheless presents a significant barrier to understanding for researchers in other fields. Specifically, an inability to comprehend the meaning of the various terms and jargons used would significantly impede understanding and navigation of the literature – and may translate into difficulty in selecting appropriate tools for the task at hand. Scientific progress – both incremental and breakthroughs - is built upon prior work. By placing various computational methods and techniques along a chronological thread, a commentary article aims to demystify the tangled web of acronyms and terms that populate the electronic structure calculations literature and highlights the interrelationships between methods – particularly, how one method evolved from another. Additionally, the chronological framework also allows readers to appreciate developments in computational chemistry through the lens of major “epochs” (e.g., transition from semi-empirical methods to first-principles calculations) and the centrality of key ideas (e.g., Schrodinger equation and Born-Oppenheimer approximation) in charting progress in the field. Finally, the chronological time-line delineated also provides an opportune backdrop for examining the perennial question of whether computational power (both capacity and speed) or theoretical insights play a more important role in advancing computational chemistry research. Particularly, while availability of large amount of computational power at declining cost and advent of graphics processing unit (GPU) powered parallel computing are enabling tools for solving hitherto intractable problems; the article argues, using Born-Oppenheimer approximation as an example, that theoretical insights’ role in unlocking problems through simple – but insightful – assumptions is often overlooked. Collectively, the article should be useful as a primer for researchers to gain a more holistic understanding of computational chemistry, and students wishing to learn more about the conceptual basis and purpose of various electronic structure calculations methods prior to venturing into the field’s expansive literature.
A newly developed dispersal capacity metric indicates the succession of benthic invertebrates in restored rivers
Authors: Li Fengqing , Sundermann Andrea , Stoll Stefan , Haase Peter
Published: January 2018

Dispersal capacity plays a fundamental role in the riverine benthic invertebrate colonization of new habitats that emerges following flash floods or restoration. However, an appropriate measure of dispersal capacity for benthic invertebrates is still lacking. The dispersal of benthic invertebrates occurs mainly during the aquatic (larval) and aerial (adult) life stages, and the dispersal of each life stage can be further subdivided into active and passive modes. Based on these four possible dispersal modes, we first developed a simple metric to estimate the dispersal capacity for 528 benthic invertebrate taxa by incorporating a weight for each mode. Second, we tested this metric using benthic invertebrate community data from a) 23 large restored river sites with improvements of river bottom habitats dating back 1 to 10 years, b) 23 unrestored sites, and c) 298 adjacent surrounding sites in the low mountain and lowland areas of Germany. We hypothesize that our metric will reflect the temporal succession process of benthic invertebrate communities colonizing the restored sites, whereas no temporal changes are expected in the unrestored and surrounding sites. By applying our metric to these three river treatment categories, we found that the average dispersal capacity of benthic invertebrate communities in the restored sites significantly decreased in the early years following restoration, whereas there were no changes in either the unrestored or the surrounding sites. After all taxa had been divided into quartiles representing weak to strong dispersers, this pattern became even more obvious; strong dispersers colonized the restored sites during the first year after restoration and then significantly decreased over time, whereas weak dispersers continued to increase. The successful application of our metric to river restoration might be promising in further applications of this metric, for example, in assessments of rivers or metacommunity structure.
Perceptual category learning of photographic and painterly stimuli in rhesus macaques (Macaca mulatta) and humans
Authors: Altschul Drew , Jensen Greg , Terrace Herbert S
Published: January 2018

Humans are highly adept at categorizing visual stimuli, but studies of human categorization are typically validated by verbal reports. This makes it difficult to perform comparative studies of categorization using non-human animals. Interpretation of comparative studies is further complicated by the possibility that animal performance may merely reflect reinforcement learning, whereby discrete features act as discriminative cues for categorization. To assess and compare how humans and monkeys classified visual stimuli, we trained 7 rhesus macaques and 41 human volunteers to respond, in a specific order, to four simultaneously presented stimuli at a time, each belonging to a different perceptual category. These exemplars were drawn at random from large banks of images, such that the stimuli presented changed on every trial. Subjects nevertheless identified and ordered these changing stimuli correctly. Three monkeys learned to order naturalistic photographs; four others, close-up sections of paintings with distinctive styles. Humans learned to order both types of stimuli. All subjects classified stimuli at levels substantially greater than that predicted by chance or by feature-driven learning alone, even when stimuli changed one every trial. However, humans more closely resembled monkeys when classifying the more abstract painting stimuli than the photographic stimuli. This points to a common classification strategy in both species, once that humans can rely on in the absence of linguistic labels for categories.
Analysis of institutional competitiveness of junior high schools through the admission Test to High School Education
Authors: Armendáriz Joyzukey , Tarango Javier , Machin-Mastromatteo Juan Daniel
Published: January 2018

This descriptive and correlational research studies 15,658 students from 335 secondary schools in the state of Chihuahua, Mexico, through the results of the examination of admission to high school education (National High School Admission Test - EXANI I from the National Assessment Center for Education - CENEVAL) on logical-mathematical and verbal reasoning, mathematics and Spanish, comparing along the variables of sex, system (public or private), type of school of origin (there are seven types) and ranking of grades, with which, the main objective is to identify levels of institutional competitiveness. The main findings of the research were: (i) private schools, in comparison with public ones, showed percentages of more favorable grades (60.54 and 43.58 respectively); (ii) influence of the academic average of the students in the result of the examination of admission (correlation of .0403; (iii) greater competence in the area of verbal reasoning (56.47) compared to logical-mathematical reasoning (55.69); and (iv) the identification of a small number of secondary schools considered as having sufficient institutional competitiveness (11 schools, equivalent to 3.28% of the total).
Hillslope Topography Mediates Spatial Patterns of Ecosystem Sensitivity to Climate
Authors: Hoylman Zachary H. , Jencso Kelsey G. , Hu Jia , Martin Justin T. , Holden Zachary A. , Seielstad Carl A. , Rowell Eric M.
Published: January 2018

Understanding how hillslope topography modulates ecosystem dynamics across topoclimatic gradients is critical for predicting future climate change impacts on vegetation function. We examined the influence of hillslope topography on ecosystem productivity, structure, and photosynthetic activity across a range of water and energy availability using three independent methods in a forested watershed (Montana, USA): 308 tree cores; light detection and ranging quantification of stem density, basal area, foliar biomass, and total biomass; and the enhanced vegetation index (EVI; 1984–2012). Multiple linear regression analysis across three conifer species revealed significant increases in measured basal area increment growth rates (from 56 to 2,058 mm2/yr) with increasing values of the topographic wetness index and decreases in the climatic water deficit. At the watershed scale, we observed strong gradients in total biomass (e.g., 52 to 75 Mg/ha), which increased from ridgelines to convergent hollows. The most predominant topographic organization of forest biomass occurred along locations of climatically driven water limitations. Similarly, an analysis of growing season EVI indicated enhanced photosynthetic activity and a prolonged growing season in convergent hillslope positions. Collectively, these analyses confirm that within water‐limited landscapes, meter‐scale differences in topographic position can mediate the effects of the local energy balance and contribute to large differences in local hydrometeorological processes that are a necessary consideration for quantifying spatial patterns of ecosystem productivity. Further, they suggest that local topography and its topology with regional climate may become increasingly important for understanding spatial patterns of ecosystem productivity, mortality, and resilience as regional climates become more arid.
Hodgkin–Huxley Artificial Synaptic Membrane Based on Protonic/Electronic Hybrid Neuromorphic Transistors
Authors: Fu Yang Ming , Wan Chang Jin , Zhu Li Qiang , Xiao Hui , Chen Xiao Dong , Wan Qing
Published: January 2018

Iontronics is a newly emerging interdisciplinary concept that bridges electronics and ionics. It provides new opportunities for biomimic information processing. Iontronic devices can act as building blocks for neuromorphic platforms. Here, a proof‐of‐principle Hodgkin–Huxley artificial synaptic membrane is proposed for the first time based on inorganic proton conductor. Phosphosilicate glass‐based proton conductor electrolyte demonstrates unique short‐term volatile charging behaviors, indicating potential short‐term synaptic plasticity applications. By using protonic/electronic hybrid oxide transistor configuration, dynamic synaptic membrane potential responses are triggered with gate current spikes. Typical resting potential, excitatory/inhibitory postsynaptic potential behaviors, and membrane depolarization/activation behaviors are mimicked on the proposed Hodgkin–Huxley artificial synaptic membrane. Moreover, proton‐related electrostatic coupling enables the device to possess short‐term synaptic plasticities with low power consumption. The proposed Hodgkin–Huxley artificial synaptic membrane provides a new prototype for neuromorphic system applications.
Magnetic Actuation of Multifunctional Nanorobotic Platforms to Induce Cancer Cell Death
Authors: Serrà Albert , Vázquez‐Mariño Gonzalo , García‐Torres José , Bosch Manel , Vallés Elisa
Published: January 2018

Single‐bath potentiostatic‐pulsed electrodeposition enables the synthesis of bicomponent (i.e., gold and nickel–nickel oxide) multi‐segmented magnetic nanowires that, with extraordinarily low cytotoxicity, are ideal three‐functional medical nanoplatforms because they can transport two types of functional molecules and be magnetically actuated for both controlled targeting and inducing cancer cell death. Alternated segments of Au and Ni–Ni oxide are selected to confer a magnetic character to the nanowires, prevent their dissolution in the cellular medium, and permit selective bio‐functionalization with thiol and porphyrin test molecules. The bi‐functionalized nanowires internalized in HeLa cancer cells, similar to other organelles, move inside the living cells. Applying the rotating magnetic fields cause them vibrate and increase their motion, although high viscosity and the presence of the cytoskeleton and other protein matrices preclude their rotation inside cells. Since no magneto‐mechanical destruction of the HeLa cells occurs on their membranes, organelles, or cytoskeletons programmed cancer cell death is likely induced by the vibration and translation of the nanowires, not by mechanical destruction.
Ferroelectricity in Polar Polymer‐Based FETs: A Hysteresis Analysis
Authors: Georgiou Vasileia , Veksler Dmitry , Campbell Jason P. , Shrestha Pragya R. , Ryan Jason T. , Ioannou Dimitris E. , Cheung Kin P.
Published: January 2018

There is an increasing number of reports on polar polymer‐based ferroelectric field effect transistors (FeFETs), where the hysteresis of the drain current–gate voltage (Id–Vg) curve is investigated as the result of the ferroelectric polarization effect. However, separating ferroelectric effect from many of the factors (such as charge injection/trapping and the presence of mobile ions in the polymer) that confound interpretation is still confusing and controversial. This work presents a methodology to reliably identify the confounding factors which obscure the polarization effect in FeFETs. Careful observation of the Id–Vg curves, as well as monitoring the Id–Vg hysteresis and flat band voltage shift as a function of temperature and sweep frequency, identifies the dominant mechanism. This methodology is demonstrated by using 15 nm thick high glass transition temperature polar polymer‐based FeFETs. In these devices, room temperature hysteresis is largely a consequence of charge trapping and mobile ions, while ferroelectric polarization is observed at elevated temperatures. This methodology can be used to unambiguously prove the effect of ferroelectric polarization in FeFETs.
New Strategy for Polysulfide Protection Based on Atomic Layer Deposition of TiO2 onto Ferroelectric‐Encapsulated Cathode: Toward Ultrastable Free‐Standing Room Temperature Sodium–Sulfur Batteries
Authors: Ma Dingtao , Li Yongliang , Yang Jingbo , Mi Hongwei , Luo Shan , Deng Libo , Yan Chaoyi , Rauf Muhammad , Zhang Peixin , Sun Xueliang , Ren Xiangzhong , Li Jianqing , Zhang Han
Published: January 2018

The room temperature (RT) sodium–sulfur batteries (Na–S) hold great promise for practical applications including energy storage and conversion due to high energy density, long lifespan, and low cost, as well based on the abundant reserves of both sodium metal and sulfur. Herein, freestanding (C/S/BaTiO3)@TiO2 (CSB@TiO2) electrode with only ≈3 wt% of BaTiO3 additive and ≈4 nm thickness of amorphous TiO2 atomic layer deposition protective layer is rational designed, and first used for RT Na–S batteries. Results show that such cathode material exhibits high rate capability and excellent durability compared with pure C/S and C/S/BaTiO3 electrodes. Notably, this CSB@TiO2 electrode performs a discharge capacity of 524.8 and 382 mA h g−1 after 1400 cycles at 1 A g−1 and 3000 cycles at 2 A g−1, respectively. Such superior electrochemical performance is mainly attributed from the “BaTiO3‐C‐TiO2” synergetic structure within the matrix, which enables effectively inhibiting the shuttle effect, restraining the volumetric variation and stabilizing the ionic transport interface.
Helical Nanomachines as Mobile Viscometers
Authors: Ghosh Arijit , Dasgupta Debayan , Pal Malay , Morozov Konstantin I. , Leshansky Alexander M. , Ghosh Ambarish
Published: January 2018

A wide variety of applications are envisioned and demonstrated with artificial micro‐ and nanomachines, ranging from targeted drug or gene delivery, microsurgery, environmental sensing, and many more. Here, it is demonstrated how helical nanomachines can be used to measure and map the local mechanical properties of a complex heterogeneous environment. The positions of the nanomachines are precisely controlled using externally applied magnetic fields, while their instantaneous orientations provide estimation of the viscosity of the surrounding medium with high spatial and temporal accuracy. The measurement technique can be applied to both Newtonian as well as shear thinning media, and all experimental results are in good agreement with the theoretical analysis. It is believed that this novel application of helical nanomachines can be particularly relevant to biophysical studies and microfluidic technologies.
pH‐Responsive PEG–Doxorubicin‐Encapsulated Aza‐BODIPY Nanotheranostic Agent for Imaging‐Guided Synergistic Cancer Therapy
Authors: Chen Dapeng , Tang Qianyun , Zou Jianhua , Yang Xiaoyan , Huang Wei , Zhang Qi , Shao Jinjun , Dong Xiaochen
Published: January 2018

Synergistic cancer therapy is of great interest for multiple advantages, such as excellent targeting accuracy, low side effects, and enhanced therapeutic efficiency. Herein, a near‐infrared photosensitizer aza‐BODIPY (AB) with high singlet oxygen quantum yield (ΦΔ= 82%) is designed and synthesized. With Schiff's base obtained from condensation reaction between doxorubicin (DOX) and polyethylene glycol‐benzaldehyde (PEG–CHO) as the polymer matrix, aza‐BODIPY is encapsulated to afford hydrophilic nanoparticles (DAB NPs). The DAB NPs exhibit high reactive oxygen species (ROS) generation rate and outstanding photothermal conversion efficiency (η = 38.3%) under irradiation. In vivo fluorescence‐ and photothermal‐imaging (PTI) results demonstrate that DAB NPs can specifically accumulate at tumor sites and serve as dual‐modal imaging probe for cancer diagnosis. Particularly, triggered by acidic tumor microenvironment, the HCN bond of Schiff's base would be broken simultaneously, resulting in the efficient release of DOX from DAB NPs at tumor sites as well as enhancing the targeting performance of chemotherapeutics. Compared with free DOX and aza‐BODIPY nanoparticles, DAB NPs can inhibit tumor growth more effectively through pH‐responsive photodynamic/photothermal/chemo synergistic therapy. This report may also present a practicable strategy to develop a pH‐responsive nanotheranostic agent for tumor targeting, imaging, and therapy.
Stable High‐Index Faceted Pt Skin on Zigzag‐Like PtFe Nanowires Enhances Oxygen Reduction Catalysis
Authors: Luo Mingchuan , Sun Yingjun , Zhang Xu , Qin Yingnan , Li Mingqiang , Li Yingjie , Li Chunji , Yang Yong , Wang Lei , Gao Peng , Lu Gang , Guo Shaojun
Published: January 2018

Selectively exposing active surfaces and judiciously tuning the near‐surface composition of electrode materials represent two prominent means of promoting electrocatalytic performance. Here, a new class of Pt3Fe zigzag‐like nanowires (Pt‐skin Pt3Fe z‐NWs) with stable high‐index facets (HIFs) and nanosegregated Pt‐skin structure is reported, which are capable of substantially boosting electrocatalysis in fuel cells. These unique structural features endow the Pt‐skin Pt3Fe z‐NWs with a mass activity of 2.11 A mg−1 and a specifc activity of 4.34 mA cm−2 for the oxygen reduction reaction (ORR) at 0.9 V versus reversible hydrogen electrode, which are the highest in all reported PtFe‐based ORR catalysts. Density function theory calculations reveal a combination of exposed HIFs and formation of Pt‐skin structure, leading to an optimal oxygen adsorption energy due to the ligand and strain effects, which is responsible for the much enhanced ORR activities. In contrast to previously reported HIFs‐based catalysts, the Pt‐skin Pt3Fe z‐NWs maintain ultrahigh durability with little activity decay and negligible structure transformation after 50 000 potential cycles. Overcoming a key technical barrier in electrocatalysis, this work successfully extends the nanosegregated Pt‐skin structure to nanocatalysts with HIFs, heralding the exciting prospects of high‐effcient Pt‐based catalysts in fuel cells.
Nickel‐Based (Photo)Electrocatalysts for Hydrogen Production
Authors: Ji Lvlv , Lv Cuncai , Chen Zuofeng , Huang Zhipeng , Zhang Chi
Published: January 2018

Hydrogen is considered a promising energy carrier for replacing traditional fossil fuels. Electrochemical or solar‐driven water splitting is a green and sustainable method of producing hydrogen. To lower the overpotential and minimize energy costs, numerous reports have focused on developing noble‐metal‐free catalysts for hydrogen production, with special attention paid to nickel‐based materials. Herein, the current state of research on the use of Ni‐based materials as electrocatalysts, cocatalysts, and photoactive materials in hydrogen production is reviewed. Recent research efforts toward the development of various Ni‐based (photo)electrocatalysts, their applications in hydrogen production, and the corresponding mechanisms are covered. The approaches used to improve or optimize these materials are summarized, and the key remaining challenges are discussed.
In Situ shRNA Synthesis on DNA–Polylactide Nanoparticles to Treat Multidrug Resistant Breast Cancer
Authors: Ni Qianqian , Zhang Fuwu , Zhang Yunlei , Zhu Guizhi , Wang Zhe , Teng Zhaogang , Wang Chunyan , Yung Bryant C. , Niu Gang , Lu Guangming , Zhang Longjiang , Chen Xiaoyuan
Published: January 2018

Nanomedicine has shown unprecedented potential for cancer theranostics. Nucleic acid (e.g., DNA and RNA) nanomedicines are of particular interest for combination therapy with chemotherapeutics. However, current nanotechnologies to construct such nucleic acid nanomedicines, which rely on chemical conjugation or physical complexation of nucleic acids with chemotherapeutics, have restrained their clinical translation due to limitations such as low drug loading efficiency and poor biostability. Herein, in situ rolling circle transcription (RCT) is applied to synthesize short hairpin RNA (shRNA) on amphiphilic DNA–polylactide (PLA) micelles. Core–shell PLA@poly‐shRNA structures that codeliver a high payload of doxorubicin (Dox) and multidrug resistance protein 1 (MDR1) targeted shRNA for MDR breast cancer (BC) therapy are developed. DNA–PLA conjugates are first synthesized, which then self‐assemble into amphiphilic DNA–PLA micelles; next, using the conjugated DNA as a promoter, poly‐shRNA is synthesized on DNA–PLA micelles via RCT, generating PLA@poly‐shRNA microflowers; and finally, microflowers are electrostatically condensed into nanoparticles using biocompatible and multifunctional poly(ethylene glycol)‐grafted polypeptides (PPT‐g‐PEG). These PLA@poly‐shRNA@PPT‐g‐PEG nanoparticles are efficiently delivered into MDR breast cancer cells and accumulated in xenograft tumors, leading to MDR1 silencing, intracellular Dox accumulation, potentiated apoptosis, and enhanced tumor therapeutic efficacy. Overall, this nanomedicine platform is promising to codeliver anticancer nucleic acid therapeutics and chemotherapeutics.
Hierarchical Porous Nanosheets Constructed by Graphene‐Coated, Interconnected TiO2 Nanoparticles for Ultrafast Sodium Storage
Authors: Li Baosong , Xi Baojuan , Feng Zhenyu , Lin Yue , Liu Jincheng , Feng Jinkui , Qian Yitai , Xiong Shenglin
Published: January 2018

Sodium‐ion batteries (SIBs) are considered promising next‐generation energy storage devices. However, a lack of appropriate high‐performance anode materials has prevented further improvements. Here, a hierarchical porous hybrid nanosheet composed of interconnected uniform TiO2 nanoparticles and nitrogen‐doped graphene layer networks (TiO2@NFG HPHNSs) that are synthesized using dual‐functional C3N4 nanosheets as both the self‐sacrificing template and hybrid carbon source is reported. These HPHNSs deliver high reversible capacities of 146 mA h g−1 at 5 C for 8000 cycles, 129 mA h g−1 at 10 C for 20 000 cycles, and 116 mA h g−1 at 20 C for 10 000 cycles, as well as an ultrahigh rate capability up to 60 C with a capacity of 101 mA h g−1. These results demonstrate the longest cyclabilities and best rate capability ever reported for TiO2‐based anode materials for SIBs. The unprecedented sodium storage performance of the TiO2@NFG HPHNSs is due to their unique composition and hierarchical porous 2D structure.
Liquid Letters
Authors: Shi Shaowei , Liu Xubo , Li Yanan , Wu Xuefei , Wang Dong , Forth Joe , Russell Thomas P.
Published: January 2018

Using the interfacial jamming of cellulose nanocrystal (CNC) surfactants, a new concept, termed all‐liquid molding, is introduced to produce all‐liquid objects that retain the shape and details of the mold with high fidelity, yet remain all liquid and are responsive to external stimuli. This simple process, where the viscosity of the CNC dispersion can range from that of water to a crosslinked gel, opens tremendous opportunities for encapsulation, delivery systems, and unique microfluidic devices. The process described is generally applicable to any functionalized nanoparticles dispersed in one liquid and polymer ligands having complementary functionality dissolved in a second immiscible liquid. Such sculpted liquids retain all the characteristics of the liquids but retain shape indefinitely, very much like a solid, and provide a new platform for next‐generation soft materials.
Digitalizing Self‐Assembled Chiral Superstructures for Optical Vortex Processing
Authors: Chen Peng , Ma Ling‐Ling , Duan Wei , Chen Ji , Ge Shi‐Jun , Zhu Zhi‐Han , Tang Ming‐Jie , Xu Ran , Gao Wei , Li Tao , Hu Wei , Lu Yan‐Qing
Published: January 2018

Cholesteric liquid crystal (CLC) chiral superstructures exhibit unique features; that is, polychromatic and spin‐determined phase modulation. Here, a concept for digitalized chiral superstructures is proposed, which further enables the arbitrary manipulation of reflective geometric phase and may significantly upgrade existing optical apparatus. By encoding a specifically designed binary pattern, an innovative CLC optical vortex (OV) processor is demonstrated. Up to 25 different OVs are extracted with equal efficiency over a wavelength range of 116 nm. The multiplexed OVs can be detected simultaneously without mode crosstalk or distortion, permitting a polychromatic, large‐capacity, and in situ method for parallel OV processing. Such complex but easily fabricated self‐assembled chiral superstructures exhibit versatile functionalities, and provide a satisfactory platform for OV manipulation and other cutting‐edge territories. This work is a vital step towards extending the fundamental understanding and fantastic applications of ordered soft matter.
Binuclear Copper Complex Ink as a Seed for Electroless Copper Plating Yielding >70% Bulk Conductivity on 3D Printed Polymers
Authors: Farraj Yousef , Layani Michael , Yaverboim Avi , Magdassi Shlomo
Published: January 2018

3D printed electronics is an emerging field of high importance in both academic research and industrial manufacturing. It enables fabrication of 3D devices with embedded or conformal electronic circuits, which are relevant to a variety of applications, such as Internet of things, soft robotics, and medical devices. Patterning of electrical conductors with conductivity higher than 50% bulk copper is challenging and usually involves electroless or electrolytic deposition processes that require the use of very costly catalyst, mainly palladium, as a seed material. Here, the use of a binuclear copper complex as a very efficient replacement for the conventional catalysts, which can be directly inkjet printed onto 3D plastic objects, is described. After printing, the copper complex is converted into pure copper upon short exposure to low‐temperature plasma. By combining the binuclear complex with electroless plating, resistivity as low as 2.38 µΩ cm, which corresponds to a 72% conductivity of bulk copper, is obtained. The applicability of the complex ink and the process is demonstrated in the fabrication of a near‐field communication antenna on a 3D printed plastic object.
Fabrication of Excellent Heterojunction Assisting by Interfaced Oxygen Vacancy to Improve the Separation Capacity of Photogenerated Carriers
Authors: Sun Dandan , Zhang Yue , Yan Shuang , Sun Kaili , Wang Guixue , Bu Yuyu , Xie Guangwen
Published: January 2018

Heterojunction connecting by interface chemical bonds is a promising method as it can provide more efficient route for photogenerated charge separation. In this work, the oxygen vacancies are introduced into the surface of SrTiO3 by a one‐step hydrogenation method. SrTiO3 with oxygen vacancy (STO) is compounded with Cd0.5Zn0.5S (CZS) by hydrothermal method, resulting in the successful formation of a good heterojunction structure. By comparing with the pristine SrTiO3/CZS composites, it is found that the oxygen vacancies play an important role in the formation of excellent heterojunctions, in addition to the traditional reports as charge traps and adsorption sites or the ability to cause band changes. X‐ray photoelectron spectroscopy (XPS) and high‐resolution transmission electron microscope results disclose that S2− enters the oxygen vacancy on the (110) plane of STO and interacts with the adjacent Ti in the van der Waals force to form the Ti‐O‐S group, which results in the formation of excellent heterojunctions and makes the CZS nanoparticles growth evenly on the STO nanoplates. Furthermore, the formation of excellent heterojunction and the introduction of interfaced oxygen vacancy significantly improve the separation efficiency of photogenerated charge carriers, which dramatically increases the photoelectrochemical performance.
High‐Efficiency Thin‐Film Superlattice Thermoelectric Cooler Modules Enabled by Low Resistivity Contacts
Authors: He Yuping , Léonard François , Medlin Douglas L. , Baldasaro Nicholas , Temple Dorota S. , Barletta Philip , Spataru Catalin D.
Published: January 2018

V‐telluride superlattice thin films have shown promising performance for on‐chip cooling devices. Recent experimental studies have indicated that device performance is limited by the metal/semiconductor electrical contacts. One challenge in realizing a low resistivity contact is the absence of fundamental knowledge of the physical and chemical properties of interfaces between metal and V‐telluride materials. This study presents a combination of experimental and theoretical efforts to understand, design, and harness low resistivity contacts to V‐tellurides. Ab initio calculations are used to explore the effects of interfacial structure and chemical compositions on the electrical contacts, and an ab initio based macroscopic model is employed to predict the fundamental limit of contact resistivity as a function of both carrier concentration and temperature. Under the guidance of theoretical studies, an experimental approach is developed to fabricate low resistivity metal contacts to V‐telluride thin film superlattices, achieving a 100‐fold reduction compared to previous work. Interfacial characterization and analysis using both scanning transmission electron microscopy and energy‐dispersive X‐ray spectroscopy show unusual interfacial morphology and the potential for further improvement in contact resistivity. Finally, the improved contacts are harnessed to realize an improved high‐performance thermoelectric cooling module.
Sodium–Sulfur Flow Battery for Low‐Cost Electrical Storage
Authors: Yang Fengchang , Mousavie Seyed Mohammad Ali , Oh Tae K. , Yang Tairan , Lu Yingqi , Farley Charles , Bodnar Robert J. , Niu Li , Qiao Rui , Li Zheng
Published: January 2018

A new sodium–sulfur (Na–S) flow battery utilizing molten sodium metal and flowable sulfur‐based suspension as electrodes is demonstrated and analyzed for the first time. Unlike the conventional flow battery and the high‐temperature Na–S battery, the proposed flow battery system decouples the energy and power thermal management by operating at different temperatures for the storage tank (near room temperature) and the power stack (100–150 °C). The new Na–S flow battery offers several advantages such as easy preparation and integration of the electrode, low energy efficiency loss due to temperature maintenance, great tolerance of the volume change of the metal anode, and efficient utilization of sulfur. The Na–S flow battery has an estimated system cost in the range of $50–100 kWh−1 which is very competitive for grid‐scale energy storage applications.
New Na‐Ion Solid Electrolytes Na4−xSn1−xSbxS4 (0.02 ≤ x ≤ 0.33) for All‐Solid‐State Na‐Ion Batteries
Authors: Heo Jongwook W. , Banerjee Abhik , Park Kern Ho , Jung Yoon Seok , Hong Seung‐Tae
Published: January 2018

Sulfide Na‐ion solid electrolytes (SEs) are key to enable room‐temperature operable all‐solid‐state Na‐ion batteries that are attractive for large‐scale energy storage applications. To date, few sulfide Na‐ion SEs have been developed and most of the SEs developed contain P and suffer from poor chemical stability. Herein, discovery of a new structural class of tetragonal Na4−xSn1−xSbxS4 (0.02 ≤ x ≤ 0.33) with space group I41/acd is described. The evolution of a new phase, distinctly different from Na4SnS4 or Na3SbS4, allows fast ionic conduction in 3D pathways (0.2–0.5 mS cm−1 at 30 °C). Moreover, their excellent air stability and reversible dissolution in water and precipitation are highlighted. Specifically, TiS2/Na–Sn all‐solid‐state Na‐ion batteries using Na3.75Sn0.75Sb0.25S4 demonstrates high capacity (201 mA h (g of TiS2)−1) with excellent reversibility.
Preclinical therapeutic efficacy of the ciprofloxacin‐eluting sinus stent for Pseudomonas aeruginosa sinusitis
Authors: Cho Do‐Yeon , Lim Dong‐Jin , Mackey Calvin , Skinner Daniel , Weeks Christopher , Gill Gobind S. , Hergenrother Robert W. , Swords William E. , Woodworth Bradford A.
Published: January 2018

Background

The ciprofloxacin‐coated sinus stent (CSS) has unique therapeutic potential to deliver antibiotics to the sinuses. The objective of this study is to evaluate the efficacy of the CSS stent in eliminating Pseudomonas aeruginosa infection in a rabbit model of sinusitis.

Methods

A ciprofloxacin‐eluting sinus stent was created by coating ciprofloxacin/Eudragit RS100 on biodegradable poly‐D/L‐lactic acid (2 mg). After analyzing in‐vitro inhibition of P aeruginosa (PAO‐1 strain) biofilm formation, a total of 8 stents (4 shams, 4 CSSs) were placed unilaterally in rabbit maxillary sinuses via dorsal sinusotomy after inducing infection for 1 week with PAO‐1. Animals were assessed 2 weeks after stent insertion with nasal endoscopy, sinus culture, computed tomography (CT) scan, histopathology, and scanning electron microscopy (SEM).

Results

PAO‐1 biofilm formation was significantly reduced in vitro with exposure to the CSS (p < 0.0001). Insertion of the stent in PAO‐1–infected rabbits for 2 weeks resulted in significant improvement in sinusitis according to endoscopy scoring (p < 0.0001) and CT scoring (p < 0.002). Histology and SEM revealed marked improvement in the structure of the mucosa and submucosa with no detection of biofilm structures in the CSS cohort.

Conclusion

Although this study had a small sample size, we identified robust therapeutic efficacy of the CSS by reducing bacterial load and biofilm formation of P aeruginosa in a preclinical model of sinusitis after placement for 2 weeks.
Cross‐Linking/Mass Spectrometry for Studying Protein Structures and Protein–Protein Interactions: Where Are We Now and Where Should We Go from Here?
Authors: Sinz Andrea
Published: January 2018

Structural mass spectrometry (MS) is gaining increasing importance for deriving valuable three‐dimensional structural information on proteins and protein complexes, and it complements existing techniques, such as NMR spectroscopy and X‐ray crystallography. Structural MS unites different MS‐based techniques, such as hydrogen/deuterium exchange, native MS, ion‐mobility MS, protein footprinting, and chemical cross‐linking/MS, and it allows fundamental questions in structural biology to be addressed. In this Minireview, I will focus on the cross‐linking/MS strategy. This method not only delivers tertiary structural information on proteins, but is also increasingly being used to decipher protein interaction networks, both in vitro and in vivo. Cross‐linking/MS is currently one of the most promising MS‐based approaches to derive structural information on very large and transient protein assemblies and intrinsically disordered proteins.
LMI‐Based Robust PID Controller Design for Voltage Control of Islanded Microgrid
Authors: Armin Maniza , Roy Priyo Nath , Sarkar Subroto K. , Das Sajal K.
Published: January 2018

This paper presents the design of a robust proportional integral derivative (PID) controller for the control of a single phase microgrid voltage. A microgrid consists of loads, distributed generation units and several power‐electronics interfaced LC filter and voltage source inverter. These loads are unknown and parameters are uncertain which produce unmodeled load dynamics. This unmodeled load dynamics reduces the voltage tracking performance of the microgrid. The proposed controller gives the robustness of the system with unmodeled load dynamics. Under different kinds of uncertainties, PID controller guarantees the stability and provides zero steady‐state error and fast transient response. The robustness and optimal performance of the controller is obtained by using linear matrix inequality approach. The performance of the controller under different uncertainties is studied. Results indicate the robustness and high voltage tracking performance of the microgrid system.
Delayed Feedback MPC Algorithms of Vehicle Platoons Subject to Constraints on Measurement Range and Driving Behaviors
Authors: Yu Shi‐Ming , Wu Sai‐Nan , Zhao Yun‐Bo , He De‐Feng
Published: January 2018

The control problem of vehicle platoons considering sensors with limited measurement range and actuator time delay is investigated in the face of constraints. A new delayed feedback model predictive control scheme is proposed to solve the problem while satisfying the constraints on measurement range and driving behaviors. A family of controllers is presented with free parameters which are then computed by online solving of a receding horizon optimal control problem. Terminal equality constraints are adopted to guarantee stability of the closed‐loop system. Some sufficient conditions with guaranteed string stability of the platoon and zero steady‐state error are established. The effectiveness and advantages of the presented method are demonstrated by simulating two classical road scenarios.
The symbolic violence of setting: A Bourdieusian analysis of mixed methods data on secondary students’ views about setting
Authors: Archer Louise , Francis Becky , Miller Sarah , Taylor Becky , Tereshchenko Antonina , Mazenod Anna , Pepper David , Travers Mary‐Claire
Published: January 2018

‘Setting’ is a widespread practice in the UK, despite little evidence of its efficacy and substantial evidence of its detrimental impact on those allocated to the lowest sets. Taking a Bourdieusian approach, we propose that setting can be understood as a practice through which the social and cultural reproduction of dominant power relations is enacted within schools. Drawing on survey data from 12,178 Year 7 (age 11/12) students and discussion groups and individual interviews with 33 students, conducted as part of a wider project on secondary school grouping practices, we examine the views of students who experience setting, exploring the extent to which the legitimacy of the practice is accepted or challenged, focusing on students’ negative views about setting. Analyses show that privileged students (White, middle class) were most likely to be in top sets whereas working‐class and Black students were more likely to be in bottom sets. Students in the lowest sets (and boys, Black students and those in receipt of free school meals) were the most likely to express negative views of setting and to question the legitimacy and ‘fairness’ of setting as a practice, whereas top‐set students defended the legitimacy of setting and set allocations as ‘natural’ and ‘deserved’. This paper argues that setting is incompatible with social justice approaches to education and calls for the foregrounding of the views of those who are disadvantaged by the practice as a tool for challenging the doxa of setting.
Donor Variability in Growth Kinetics of Healthy hMSCs Using Manual Processing: Considerations for Manufacture of Cell Therapies
Authors: Detela Giulia , Bain Owen W. , Kim Hae‐Won , Williams David J. , Mason Chris , Mathur Anthony , Wall Ivan B.
Published: January 2018

Human mesenchymal stromal cells (hMSCs) are excellent candidates for cell therapy but their expansion to desired clinical quantities can be compromised by ex vivo processing, due to differences between donor material and process variation. The aim of this article is to characterize growth kinetics of healthy baseline “reference” hMSCs using typical manual processing. Bone‐marrow derived hMSCs from ten donors are isolated based on plastic adherence, expanded, and analyzed for their growth kinetics until passage 4. Results indicate that hMSC density decreases with overall time in culture (p < 0.001) but no significant differences are observed between successive passages after passage 1. In addition, fold increase in cell number dropped between passage 1 and 2 for three batches, which correlated to lower performance in total fold increase and expansion potential of these batches, suggesting that proliferative ability of hMSCs can be predicted at an early stage. An indicative bounded operating window is determined between passage 1 and 3 (PDL < 10), despite the high inter‐donor variability present under standardized hMSC expansion conditions used. hMSC growth profile analysis will be of benefit to cell therapy manufacturing as a tool to predict culture performance and attainment of clinically‐relevant yields, therefore stratifying the patient population based on early observation.