bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanoarchitectonics for Transition‐Metal‐Sulfide‐Based Electrocatalysts for Water Splitting
Authors: Guo Yanna , Park Teahoon , Yi Jin Woo , Henzie Joel , Kim Jeonghun , Wang Zhongli , Jiang Bo , Bando Yoshio , Sugahara Yoshiyuki , Tang Jing , Yamauchi Yusuke 
Published: February 2019

AbstractHeterogenous electrocatalysts based on transition metal sulfides (TMS) are being actively explored in renewable energy research because nanostructured forms support high intrinsic activities for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, it is described how researchers are working to improve the performance of TMS‐based materials by manipulating their internal and external nanoarchitectures. A general introduction to the water‐splitting reaction is initially provided to explain the most important parameters in accessing the catalytic performance of nanomaterials catalysts. Later, the general synthetic methods used to prepare TMS‐based materials are explained in order to delve into the various strategies being used to achieve higher electrocatalytic performance in the HER. Complementary strategies can be used to increase the OER performance of TMS, resulting in bifunctional water‐splitting electrocatalysts for both the HER and the OER. Finally, the current challenges and future opportunities of TMS materials in the context of water splitting are summarized. The aim herein is to provide insights gathered in the process of studying TMS, and describe valuable guidelines for engineering other kinds of nanomaterial catalysts for energy conversion and storage technologies.
3D Scaffolds to Study Basic Cell Biology
Authors: Hippler Marc , Lemma Enrico Domenico , Bertels Sarah , Blasco Eva , Barner‐Kowollik Christopher , Wegener Martin , Bastmeyer Martin 
Published: February 2019

AbstractMimicking the properties of the extracellular matrix is crucial for developing in vitro models of the physiological microenvironment of living cells. Among other techniques, 3D direct laser writing (DLW) has emerged as a promising technology for realizing tailored 3D scaffolds for cell biology studies. Here, results based on DLW addressing basic biological issues, e.g., cell‐force measurements and selective 3D cell spreading on functionalized structures are reviewed. Continuous future progress in DLW materials engineering and innovative approaches for scaffold fabrication will enable further applications of DLW in applied biomedical research and tissue engineering.
ATG7 Promotes Bladder Cancer Invasion via Autophagy‐Mediated Increased ARHGDIB mRNA Stability
Authors: Zhu Junlan , Tian Zhongxian , Li Yang , Hua Xiaohui , Zhang Dongyun , Li Jingxia , Jin Honglei , Xu Jiheng , Chen Wei , Niu Beifang , Wu Xue‐Ru , Comincini Sergio , Huang Haishan , Huang Chuanshu 
Published: February 2019

AbstractSince invasive bladder cancer (BC) can progress to life threatening metastases, understanding the molecular mechanisms underlying BC invasion is crucial for potentially decreasing the mortality of this disease. Herein, it is discovered that autophagy‐related gene 7 (ATG7) is remarkably overexpressed in human invasive BC tissues. The knockdown of ATG7 in human BC cells dramatically inhibits cancer cell invasion, revealing that ATG7 is a key player in regulating BC invasion. Mechanistic studies indicate that MIR190A is responsible for ATG7 mRNA stability and protein overexpression by directly binding to ATG7 mRNA 3′‐UTR. Furthermore, ATG7‐mediated autophagy promotes HNRNPD (ARE/poly(U)‐binding/degradation factor 1) protein degradation, and in turn reduces HNRNPD interaction with ARHGDIB mRNA, resulting in the elevation of ARHGDIB mRNA stability, and subsequently leading to BC cell invasion. The identification of the MIR190A/ATG7 autophagic mechanism regulation of HNRNPD/ARHGDIB expression provides an important insight into understanding the nature of BC invasion and suggests that autophagy may represent a potential therapeutic strategy for the treatment of human BC patients.
Ultrafine α‐Phase Molybdenum Carbide Decorated with Platinum Nanoparticles for Efficient Hydrogen Production in Acidic and Alkaline Media
Authors: Song Hee Jo , Sung Myeong‐Chang , Yoon Hyunseok , Ju Bobae , Kim Dong‐Wan 
Published: February 2019

AbstractThe development of efficient electrocatalysts is important to produce clean and sustainable hydrogen fuel on a large scale. With respect to cathodic reactions, Pt exhibits an overwhelming electrocatalytic capability in the hydrogen evolution reaction (HER) in comparison with other earth‐abundant electrocatalysts, despite its rarity and high cost. So, a hybrid catalyst that combines a low‐cost electrocatalyst with Pt would balance cost‐effectiveness with catalytic activity. Herein, α‐phase molybdenum carbide (MoC1−x) nanoparticles (NPs) decorated with a small amount of Pt (MoC1−x/Pt‐NPs) are designed to achieve high‐performance hydrogen production in acidic and alkaline media. MoC1−x‐NPs exhibit good electrocatalytic HER activity as well as stability and durability. They show favorable catalytic kinetics in an alkaline medium, suggesting an active water dissociation process. After Pt decoration, Pt‐NPs that are 2–3 nm in diameter are well incorporated with MoC1−x‐NPs. MoC1−x/Pt‐NPs with a small amount of Pt (2.7–3 wt%) and are able to perform superior electrocatalytic HER activity, and possess stability and durability that is comparable to that of commercial Pt/C. Notably, they exhibit a higher intrinsic catalytic activity compared to that of Pt/C in an alkaline medium, indicating that they promote the sluggish catalytic kinetics of Pt in alkaline medium.
The Effect of Electrostatic Interaction on n‐Type Doping Efficiency of Fullerene Derivatives
Authors: Liu Jian , Maity Sudeshna , Roosloot Nathan , Qiu Xinkai , Qiu Li , Chiechi Ryan C. , Hummelen Jan C. , von Hauff Elizabeth , Koster L. Jan Anton 
Published: February 2019

AbstractThe molecular doping of organic semiconductors represents a key strategy for advancing organic electronic applications. However, the n‐doping of organic materials is usually less efficient than p‐doping and strategies toward the design of more efficient n‐doping still remain less explored. In this contribution, the impact of electrostatic interaction is explored on the doping efficiency of fullerene derivatives. [6,6]‐Phenyl‐C61‐butyric acid methyl ester (PCBM) and a [60]fulleropyrrolidine with a more polarizable triethylene glycol type side chain (PTEG‐1) are employed for a comparative study. It is found that the doping efficiency of lightly doped PCBM layers is limited to a few percent, while doped PTEG‐1 films exhibit very high doping efficiency approaching 100%. The enhanced n‐doping of PTEG‐1 compared with that of PCBM is further substantiated by Raman and Fourier transform infrared spectroscopic studies. The activation energy for charge generation in doped PTEG‐1 is much smaller than that of doped PCBM, which confirms a higher probability for dissociation of charge transfer complexes in the former compared to the latter. The enhanced molecular n‐doping for PTEG‐1 is attributed to the electrostatic interaction between the charge transfer complex and the polar environment offered by the triethylene glycol diether side chain.
Twist and Degrade—Impact of Molecular Structure on the Photostability of Nonfullerene Acceptors and Their Photovoltaic Blends
Authors: Luke Joel , Speller Emily M. , Wadsworth Andrew , Wyatt Mark F. , Dimitrov Stoichko , Lee Harrison K. H. , Li Zhe , Tsoi Wing C. , McCulloch Iain , Bagnis Diego , Durrant James R. , Kim Ji‐Seon 
Published: February 2019

AbstractNonfullerene acceptors (NFAs) dominate organic photovoltaic (OPV) research due to their promising efficiencies and stabilities. However, there is very little investigation into the molecular processes of degradation, which is critical to guiding design of novel NFAs for long‐lived, commercially viable OPVs. Here, the important role of molecular structure and conformation in NFA photostability in air is investigated by comparing structurally similar but conformationally different promising NFAs: planar O‐IDTBR and nonplanar O‐IDFBR. A three‐phase degradation process is identified: i) initial photoinduced conformational change (i.e., torsion about the core–benzothiadiazole dihedral), induced by noncovalent interactions with environmental molecules, ii) followed by photo‐oxidation and fragmentation, leading to chromophore bleaching and degradation product formation, and iii) finally complete chromophore bleaching. Initial conformational change is a critical prerequisite for further degradation, providing fundamental understanding of the relative stability of IDTBR and IDFBR, where the already twisted IDFBR is more prone to degradation. When blended with the donor polymer poly(3‐hexylthiophene), both NFAs exhibit improved photostability while the photostability of the polymer itself is significantly reduced by the more miscible twisted NFA. The findings elucidate the important role of NFA molecular structure in photostability of OPV systems, and provide vital insights into molecular design rules for intrinsically photostable NFAs.
Scaling of phloem hydraulic resistance in stems and leaves of the understory angiosperm shrub Illicium parviflorum
Authors: Losada Juan M. , Holbrook N. Michele 
Published: February 2019

Premise of the StudyRecent studies in canopy‐dominant trees revealed axial scaling of phloem structure. However, whether this pattern is found in woody plants of the understory, the environment of most angiosperms from the ANA grade (Amborellales‐Nymphaeales‐Austrobaileyales), is unknown.MethodsWe used seedlings and adult plants of the understory tropical shrub Illicium parviflorum, a member of the lineage Austrobaileyales, to explore the anatomy and physiology of the phloem in their aerial parts, including changes through ontogeny.Key ResultsAdult plants maintain a similar proportion of phloem tissue across stem diameters, but larger conduit dimensions and number cause the hydraulic resistance of the phloem to decrease toward the base of the plant. Small sieve plate pores resulted in an overall higher sieve tube hydraulic resistance than has been reported in other woody angiosperms. Sieve elements increase in size from minor to major leaf veins, but were shorter and narrower in petioles. The low carbon assimilation rates of seedlings and mature plants contrasted with a 3‐fold higher phloem sap velocity in seedlings, suggesting that phloem transport velocity is modulated through ontogeny.ConclusionsThe overall architecture of the phloem tissue in this understory angiosperm shrub scales in a manner consistent with taller trees that make up the forest canopy. Thus, the evolution of larger sieve plate pores in canopy‐dominant trees may have played a key role in allowing woody angiosperms to extend beyond their understory origins.
The neuroplastic effect of olfactory training to the recovery of olfactory system in mouse model
Authors: Kim Boo‐Young , Park Ju Yeon , Kim Eui Jin , Kim Byung Guk , Kim Sung Won , Kim Soo Whan 
Published: February 2019

BackgroundSeveral studies have reported the benefits of olfactory training (OT) in the olfactory nervous system of mouse models. Therefore, in this study we performed next‐generation sequencing to evaluate the effects of OT on mRNA sequencing in the olfactory area.MethodsMice in each group were administered 300 mg of 3‐methylindole per kilogram of mouse weight. The olfactory function was evaluated by a food‐finding test once a week. The olfactory neuroepithelium was harvested for histologic examination and protein analysis. Subsequently, data analysis, gene ontology and pathway analysis, quantitative real‐time polymerase chain reaction of mRNA, and Western blot analysis were conducted.ResultsMice were divided into 4 groups according to treatment. Control, anosmia, training, and steroid group mice resumed food finding. Olfactory Maker Protein, olfr1507, ADCY3, and GNAL mRNA expression was higher in the olfactory neuroepithelium of OT than anosmia group mice. In total, 26,364 mRNAs were analyzed. Comparison of the results of OT vs anosmia revealed that ADCY8,10, GFAP, NGF, NGFR, GFAP, and BDNF mRNAs were upregulated in the gene ontology.ConclusionOT improved olfactory function, as indicated by the food‐finding test. OT improved the olfactory recovery time to stimulate olfactory nerve regeneration. OT may initially stimulate the olfactory receptor, followed by neurogenesis. Steroid therapy and OT operated under completely different mechanisms in the upregulated gene study. These results indicate that OT may be one of the future modalities for treating olfactory impairment.
Catalyst‐Free Deaminative Functionalizations of Primary Amines by Photoinduced Single‐Electron Transfer
Authors: Wu Jingjing , Grant Phillip S. , Li Xiabing , Noble Adam , Aggarwal Varinder K. 
Published: February 2019

AbstractThe use of pyridinium‐activated primary amines as photoactive functional groups for deaminative generation of alkyl radicals under catalyst‐free conditions is described. By taking advantage of the visible light absorptivity of electron donor–acceptor complexes between Katritzky pyridinium salts and either Hantzsch ester or Et3N, photoinduced single‐electron transfer could be initiated in the absence of a photocatalyst. This general reactivity platform has been applied to deaminative alkylation (Giese), allylation, vinylation, alkynylation, thioetherification, and hydrodeamination reactions. The mild conditions are amenable to a diverse range of primary and secondary alkyl pyridiniums and demonstrate broad functional group tolerance.
Chemical Syntheses and Chemical Biology of Carboxyl Polyether Ionophores: Recent Highlights
Authors: Liu Han , Lin Shaoquan , Jacobsen Kristian M. , Poulsen Thomas B. 
Published: February 2019

AbstractA central goal of chemical biology is to develop molecular probes that enable fundamental studies of cellular systems. In the hierarchy of bioactive molecules, the so‐called ionophore class occupies an unflattering position in the lower branches, with typical labels being “non‐specific” and “toxic”. In fact, the mere possibility that a candidate molecule possesses “ionophore activity” typically prompts its removal from further studies; ionophores—from a chemical genetics perspective—are molecular outlaws. In stark contrast to this overall poor reputation of ionophores, synthetic chemistry owes some of its most amazing achievements to studies of ionophore natural products, in particular the carboxyl polyethers renowned for their intricate molecular structures. These compounds have for decades been academic battlegrounds where new synthetic methodology is tested and retrosynthetic tactics perfected. Herein, we review the most exciting recent advances in carboxyl polyether ionophore (CPI) synthesis and in addition discuss the burgeoning field of CPI chemical biology.
CO2‐philic polyether‐block‐amide/glycerol triacetate blend membranes: gas‐permeation performance, thermal stability, and storage stability
Authors: Feng Shichao , Ren Jizhong , Zhao Dan , Li Hui , Hua Kaisheng , Li Xinxue , Deng Maicun 
Published: February 2019

ABSTRACTPolyether‐block‐amide (Pebax)/glycerol triacetate (GTA) blend membranes with various compositions were prepared with a solution‐casting method. The gas‐separation performance, thermal stability, and storage stability of the prepared membranes were investigated at different pressures and temperatures. The Arrhenius equation was used to describe the gas‐permeation performance of the Pebax1074/GTA membranes with a low GTA concentration (≤40 wt %) rather than those membranes with a high GTA concentration (>40 wt %). A higher GTA content, lower treatment temperature, and storage temperature increased the gas permeability and induced a stronger hydrostatic pressure effect. The low‐storage temperature was beneficial for fixing GTA on the blend membrane. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47620.
Acid‐treated Bentonite as filler in the development of novel composite PVA hydrogels
Authors: Sanchez Laura M. , Alvarez Vera A. , Ollier Romina P. 
Published: February 2019

ABSTRACTIn this study, novel eco‐friendly hydrogel adsorbents were synthesized based on poly(vinyl alcohol) (PVA) and different contents of an acid‐treated bentonite (1–5 wt %). The hydrogels were prepared by freezing–thawing, which is a simple and nontoxic method. The materials were morphologically and thermally characterized by means of swelling assays, X‐ray diffraction, scanning electron microscopy, dynamic scanning calorimetry, and thermogravimetric analysis in order to evaluate the effect of acid‐treated bentonite loading. The composite hydrogels showed very distinct porous structure and thermal features in comparison to neat PVA as a consequence of the addition of the clay. Moreover, the performance of the obtained composite hydrogels was tested toward the adsorption of cationic (methylene blue) and anionic dyes (methyl red and methyl orange) from aqueous media. The presence of acid bentonite seems to be beneficial for improving the removal capacity of PVA‐based hydrogels. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47663.
Improved fracturing fluid using: Organic amino boron composite crosslinker with BN covalent bond
Authors: Zhang Zhaoyang , Mao Jincheng , Zhang Yang , Han Tianxing , Yang Bo , Xiao Wei 
Published: February 2019

ABSTRACTIn order to create an improved fracturing fluid, an organic amine boron composite crosslinker (ABC‐1) was prepared from boric acid, triethylenetetramine, ethylene glycol, and mannitol. It has no irritating smell and its synthesis is simple, making it suitable for large‐scale field applications. To illustrate the advantages of the new crosslinker, it was compared to the organic borate crosslinker prepared from boric acid, ethylene glycol, and mannitol. The sand‐carrying capacities, micronetwork structure, and rheological behaviors of fluids with these crosslinkers were investigated at 90, 100, and 110 °C. The results show that the additional BN r covalent bond in the ABC‐1 crosslinker leads to the formation of a denser network structure making it possible to reduce the amount of thickener by about 10%. The temperature resistance could also be enhanced at least 10 °C. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47675.
The Spectrum of Learning and Teaching: The Impact of a Fourth‐Year Anatomy Course on Medical Student Knowledge and Confidence
Authors: Lufler Rebecca S. , Lazarus Michelle D. , Stefanik Joshua J. 
Published: February 2019

There is growing demand from accrediting agencies for improved basic science integration into fourth‐year medical curricula and inculcation of medical students with teaching skills. The objective of this study was to determine the effectiveness of a fourth‐year medical school elective course focused on teaching gross anatomy on anatomical knowledge and teaching confidence. Fourth‐year medical student “teacher” participants' gross anatomy knowledge was assessed before and after the course. Students rated their overall perceived anatomy knowledge and teaching skills on a scale from 0 (worst) to 10 (best), and responded to specific knowledge and teaching confidence items using a similar scale. First‐year students were surveyed to evaluate the effectiveness of the fourth‐year student teaching on their learning. Thirty‐two students completed the course. The mean anatomy knowledge pretest score and posttest scores were 43.2 (±22.1) and 74.1 (±18.4), respectively (P < 0.001). The mean perceived anatomy knowledge ratings before and after the course were 6.19 (±1.84) and 7.84 (±1.30), respectively (P < 0.0001) and mean perceived teaching skills ratings before and after the course were 7.94 (±1.24) and 8.53 (±0.95), respectively (P = 0.002). Student feedback highlighted five themes which impacted fourth‐year teaching assistant effectiveness, including social/cognitive congruence and improved access to learning opportunities. Together these results suggest that integrating fourth‐year medical students in anatomy teaching increases their anatomical knowledge and improves measures of perceived confidence in both teaching and anatomy knowledge. The thematic analysis revealed that this initiative has positive benefits for first‐year students.
Fault reconstruction for delay systems via least squares and time‐shifted sliding mode observers
Authors: Pinto Hardy L. C. P. , Oliveira Tiago Roux , Hsu Liu 
Published: February 2019

AbstractIn this article, we address the problem of fault reconstruction in delayed systems by introducing a time‐shifted sliding mode observer (SMO). While time‐varying delays of arbitrary duration are considered in the measured output signal, the actuator fault is parametrized as a weighted sum of known regressor functions with unknown coefficients. The prediction scheme utilizes the variation of constants formula to obtain the present time estimate of the unmeasured state. The fault is also identified at present time by means of the continuous‐time Least Squares approaches. Ideal sliding mode can be guaranteed in theory, even in the presence of such adverse delays, since there is no chattering in the output estimation error of the SMO. An application to petroleum engineering with numerical simulations is presented to show the effectiveness of the proposed method.
Robust H∞ sliding mode observer‐based fault‐tolerant control for One‐sided Lipschitz nonlinear systems
Authors: Rastegari Abbas , Arefi Mohammad Mehdi , Asemani Mohammad Hassan 
Published: February 2019

AbstractThis paper presents fault tolerant controllers for a class of one‐sided Lipschitz nonlinear systems with external disturbances. A sliding mode observer (SMO) is integrated with the H∞ filtering approach as the fault detection and isolation module. The problem is investigated in the presence of faults and disturbances simultaneously. The H∞‐SMO is capable of approximating faults accurately, while reducing the effect of disturbances in the estimation of the state vector and occurred faults. Accordingly, using only a single SMO, the estimation error of the state vector and faults can be made simultaneously arbitrarily small. In addition, to deal with the weighted bilinear form appearing in the one‐sided Lipschitz condition, the quadratically inner bounded condition presented in the literature is employed in this paper as a useful solution. The proposed method guarantees the stability of the overall closed‐loop system, and after a short transient time, the estimation errors for state vector and fault signal converge to a small neighborhood of the origin. The effectiveness of the presented algorithm is confirmed in two examples including a single arm robot with a flexible joint and a numerical simulation.
Facile reflux synthesis of polyethyleneimine‐capped fluorescent carbon dots for sequential bioassays toward Cu2+/H2S and its application for a logic system
Authors: Chen Zi‐Han , Han Xin‐Yue , Lin Zi‐Yang , Fan Yu‐Lin , Shi Guoyue , Zhang Shengqiang , Zhang Min 
Published: February 2019

AbstractIn this work, we present a novel facile strategy for green synthesis of polyethyleneimine (PEI)‐capped carbon dots (PEI‐CDs), in which citric acid and PEI were chosen as reactants and highly fluorescent PEI‐CDs could be readily obtained via a simple one‐pot refluxing under 120 °C within 2 H. Fluorescence studies indicate that the as‐prepared PEI‐CDs exhibit strong fluorescence emission at 446 nm with excitation at 365 nm. Upon the sequential addition of Cu2+ and H2S, PEI‐CDs result in an interesting “ON−OFF−ON” three‐state emission responses, promising a bifunctional sensory platform. Moreover, the Cu2+/H2S‐facilated reversible fluorescence changes of PEI‐CDs have demonstrated the design of an INHIBIT logic system based on Boolean logic.