bluuebunny/crossref_metadata_2025_split huggingface dataset:
From Passive Inorganic Oxides to Active Matters of Micro/Nanomotors
Authors: Liu Wenjuan , Chen Xiao , Lu Xiaolong , Wang Joseph , Zhang Yanan , Gu Zhongwei 
Published: July 2020

AbstractControllable actuation and coordinating motion of artificial self‐propelled micro/nanomotors to mimic the motile natural microorganism systems are of great significance for constructing intelligent nanoscale machines. In particular, inorganic oxide particles have shown considerable promise in implementation of synthetic micro/nanomotors, due to their unique features and active response to environmental stimuli. This work critically reviews the recent progress in inorganic oxide‐based micro/nanomotors and focuses on their propulsion response to chemical and physical stimuli, especially emphasizing and discussing operating principles in the single engine, adaptive navigation under composite‐driven powers, and intriguing collective behaviors. The impact of oxide structure, multiple fields in motion controllability, and interaction between grouped micro/nanomotors are explored. Practical applications of individual and assembled micro/nanomotors in environmental and biomedical fields are demonstrated, including the removal of pollutants, drug delivery, cancer therapy, and in vivo imaging. Finally, current challenges for the development of novel micro/nanomotors and possible constraints toward the defined structure and accumulated toxicity are discussed along with future opportunities and directions. Owing to their facile synthesis, impressive physicochemical performances, high biocompatibility, and versatile actuations, it is expected that the association of inorganic oxides with micro/nanomotors will bring new and unique capabilities to the field of active matter.
Active Site Engineering in Porous Electrocatalysts
Authors: Chen Hui , Liang Xiao , Liu Yipu , Ai Xuan , Asefa Tewodros , Zou Xiaoxin 
Published: July 2020

AbstractElectrocatalysis is at the center of many sustainable energy conversion technologies that are being developed to reduce the dependence on fossil fuels. The past decade has witnessed significant progresses in the exploitation of advanced electrocatalysts for diverse electrochemical reactions involved in electrolyzers and fuel cells, such as the hydrogen evolution reaction (HER), the oxygen reduction reaction (ORR), the CO2 reduction reaction (CO2RR), the nitrogen reduction reaction (NRR), and the oxygen evolution reaction (OER). Herein, the recent research advances made in porous electrocatalysts for these five important reactions are reviewed. In the discussions, an attempt is made to highlight the advantages of porous electrocatalysts in multiobjective optimization of surface active sites including not only their density and accessibility but also their intrinsic activity. First, the current knowledge about electrocatalytic active sites is briefly summarized. Then, the electrocatalytic mechanisms of the five above‐mentioned reactions (HER, ORR, CO2RR, NRR, and OER), the current challenges faced by these reactions, and the recent efforts to meet these challenges using porous electrocatalysts are examined. Finally, the future research directions on porous electrocatalysts including synthetic strategies leading to these materials, insights into their active sites, and the standardized tests and the performance requirements involved are discussed.
Recent Advances in the Construction of Spiro Compounds via Radical Dearomatization
Authors: Yang Wen‐Chao , Zhang Ming‐Ming , Feng Jian‐Guo 
Published: July 2020

AbstractThe field in dearomatization of aromatic compounds for the construction of spirocycle compounds has been developed rapidly over the last two decades and it provides alternative synthetic method without using extra stoichiometric amounts of chemical oxidants or reductants. In addition, the radical cascade reactions of alkenes or alkynes that produce multiple chemical bonds in one‐step are significant in the direct and efficient building of complex molecules. By combining these two concepts, dearomatization and radical cascade reactions of alkenes or alkynes opens a new and powerful avenue in accessing spirocycle molecules. These cascade reactions have been well explored in the past decade. As a result, we summarize recent eventful advances in this rapidly growing area as a review, in which the typical examples are listed and mechanism are also discussed.magnified image
Involvement of Unsaturated Switching in the Endurance Cycling of Si‐doped HfO2 Ferroelectric Thin Films
Authors: Li Shuaidong , Zhou Dayu , Shi Zhixin , Hoffmann Michael , Mikolajick Thomas , Schroeder Uwe 
Published: July 2020

AbstractIn the past decade, extensive studies on HfO2‐based ferroelectric thin films have been carried out in order to realize their application in high‐density, low‐power, and high‐speed nonvolatile memories. However, understanding the field cycling endurance, which is extremely important for device performance, is still a serious issue. In this work, the frequency and field dependent subcycling behavior is carefully examined. The differences in split‐up effects induced at different subcycling conditions are analyzed by comparing the evolution of polarization‐electric field and transient current hysteresis loops monitored by two subsequent triangular voltage waveforms with different amplitudes. Using the first‐order reversal curves, the evolution of the switching and backswitching field distribution before and after numerous subcycles is characterized. An intuitive model based on the migration of oxygen vacancies from switchable regions to non‐switchable regions and subsequent movement toward top/bottom electrode interface driven by the transient depolarization field is proposed to explain the generation and enhancement of local bias fields.
Soil inorganic carbon under no‐till dryland crop rotations
Authors: Sainju Upendra M. , Allen Brett L. , Jabro Jalal D. , Stevens William B. 
Published: July 2020

AbstractSoil inorganic carbon (SIC) constitutes a large proportion of soil total carbon (STC) under dryland cropping systems in arid and semiarid regions. Information on the effect of management practices on SIC is scarce. We evaluated the effect of 1‐ to 4‐yr no‐till diversified crop rotations on SIC at the 0‐ to 120‐cm depth in Sidney and Friod, MT. The SIC increased from the soil surface to 90‐cm depth and then declined. Crop rotations did not affect SIC and STC, except at 90–120 cm in Sidney where barley (Hordeum vulgare L) and winter wheat (Triticum aestivum L) in rotation with pea (Pisum sativum L.) had higher SIC than other crop rotations. The SIC contributed from 0% of STC at 0–15 cm for most crop rotations to 78% at 60–90 cm for barley–pea rotation. Long‐term studies are needed to evaluate the effect of dryland crop rotations on SIC in the northern Great Plains.
Transition‐Metal‐Mediated/Catalyzed Synthesis of Pyridines, Pyrimidines, and Triazines by [2+2+2] Cycloaddition Reactions
Authors: Nagata Tatsuki , Obora Yasushi 
Published: July 2020

AbstractNitrogen‐containing six‐membered heterocycles such as pyridines, pyrimidines, and triazines are widely used in the synthesis of natural products and pharmaceuticals. Recently, a promising approach to these structures via [2+2+2] cycloadditions of alkynes and nitriles has been developed. Transition‐metal complex catalysts play key roles in the regio‐, chemo‐, or stereo‐selectivity of transformations. Here, we summarize recent advances in metal‐mediated/catalyzed [2+2+2] cycloadditions for synthesizing pyridines and pyrimidines. We also describe progress in triazine synthesis via metal‐mediated/catalyzed nitrile cyclotrimerization.
Medical and surgical treatment outcomes in patients with chronic rhinosinusitis and immunodeficiency: a systematic review
Authors: Samargandy Shireen , Grose Elysia , Chan Yvonne , Monteiro Eric , Lee John M. , Yip Jonathan 
Published: July 2020

BackgroundImmunodeficiency is a risk factor for recalcitrant chronic rhinosinusitis (CRS). Currently, there is no consensus on effective treatment modalities for immunodeficient CRS patients. This review aims to evaluate the existing evidence on the treatment outcomes and its limitations in patients with CRS and immunodeficiency.MethodsMEDLINE, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched from inception to April 2019 for studies reporting measurable medical or surgical treatment outcomes for adult patients with CRS and underlying primary or secondary immunodeficiency.ResultsOf the 2459 articles screened, 13 studies met the inclusion criteria: 2 prospective double‐blind placebo‐controlled trials, 2 prospective case‐control studies, 2 prospective cohort studies, and 7 case series. The high degree of study heterogeneity precluded a meta‐analysis. Antibiotic monotherapy was not linked with significant improvement in clinical, radiographic, or endoscopic outcomes. Immunoglobulin replacement therapy may potentially reduce the frequency of acute or chronic sinusitis in patients with primary immunodeficiency (PID) but may not improve their sinonasal symptoms. Outcomes from endoscopic sinus surgery (ESS) were reported in 8 studies, which found that surgery was linked with improvement in symptoms, disease‐specific quality of life, endoscopy scores, and radiographic scores. The average reported ESS revision rate was 14%.ConclusionPatients with CRS and immunodeficiency likely benefit from ESS based on the available evidence. Data supporting medical therapy in this targeted population is limited overall, but there may be a potential role for immunoglobulin therapy in patients with PID and CRS.
A physician‐staffed ground emergency medical service does not significantly shorten door‐to‐balloon time in patients with STEMI: an observational study in a single emergency center in Japan
Authors: Yoshioka Yuki , Teshima Ryota , Gamo Mina , Yoneda Ryuhei , Matsunaga Naoki , Takada Tadaaki , Fukuta Yasushi , Kishi Koichi 
Published: July 2020

AimCurrent guidelines recommend a door‐to‐balloon time (DTBT) of <90 min for reperfusion treatment of patients with ST‐segment elevation myocardial infarction (STEMI). A physician‐staffed ground emergency medical service (GEMS) using a rapid response car (RRC) system was implemented at our hospital in April 2015. The medical team, including a physician and nurse, is dispatched to assess the patient and expedite the start of treatment by emergency physicians and cardiologists after arrival at the hospital. The study aimed to determine whether the RRC system shortened the DTBT.MethodsThis retrospective observational study was carried out in a tertiary emergency center in Japan. Those STEMI patients with primary percutaneous intervention between January 2016 and December 2018 were evaluated. The DTBTs of patients transported by the RRC system, the emergency medical service (EMS), and transferred from other hospitals after STEMI diagnosis (TRANS group) were compared.ResultsA total of 121 patients were included, 33 in the RCC, 20 in the EMS, and 68 in the TRANS groups. The median DTBT was 51 min (interquartile range [IQR], 43–67) in the RRC, 61 min (IQR, 52–85) in the EMS, and 59 min (IQR, 48–72) in the TRANS groups (P = 0.13). The DTBT was not significantly shorter in the RRC than in the other groups.ConclusionAn RRC physician‐staffed GEMS did not significantly shorten the DTBT of patients with STEMI compared with other transport systems.
Catalyst‐Controlled Transannular Polyketide Cyclization Cascades: Selective Folding of Macrocyclic Polyketides
Authors: Raps Felix C. , Fäseke Vincent C. , Häussinger Daniel , Sparr Christof 
Published: July 2020

AbstractThe biomimetic synthesis of aromatic polyketides from macrocyclic substrates by means of catalyst‐controlled transannular cyclization cascades is described. The macrocyclic substrates, which feature increased stability and fewer conformational states, were thereby transformed into several distinct polyketide scaffolds. The catalyst‐controlled transannular cyclizations selectively led to aromatic polyketides with a defined folding and oxygenation pattern, thus emulating β‐keto‐processing steps of polyketide biosynthesis.
Modulating Benzothiadiazole‐Based Covalent Organic Frameworks via Halogenation for Enhanced Photocatalytic Water Splitting
Authors: Chen Weiben , Wang Lei , Mo Daize , He Feng , Wen Zhilin , Wu Xiaojun , Xu Hangxun , Chen Long 
Published: July 2020

AbstractTwo‐dimensional covalent organic frameworks (2D COFs), an emerging class of crystalline porous polymers, have been recognized as a new platform for efficient solar‐to‐hydrogen energy conversion owing to their pre‐designable structures and tailor‐made functions. Herein, we demonstrate that slight modulation of the chemical structure of a typical photoactive 2D COF (Py‐HTP‐BT‐COF) via chlorination (Py‐ClTP‐BT‐COF) and fluorination (Py‐FTP‐BT‐COF) can lead to dramatically enhanced photocatalytic H2 evolution rates (HER=177.50 μmol h−1 with a high apparent quantum efficiency (AQE) of 8.45 % for Py‐ClTP‐BT‐COF). Halogen modulation at the photoactive benzothiadiazole moiety can efficiently suppress charge recombination and significantly reduce the energy barrier associated with the formation of H intermediate species (H*) on polymer surface. Our findings provide new prospects toward design and synthesis of highly active organic photocatalysts toward solar‐to‐chemical energy conversion.
Near‐Infrared Light‐Triggered Chlorine Radical (.Cl) Stress for Cancer Therapy
Authors: Song Ruixue , Wang Han , Zhang Meng , Liu Yanyan , Meng Xianfu , Zhai Shaojie , Wang Chao‐chao , Gong Teng , Wu Yelin , Jiang Xingwu , Bu Wenbo 
Published: July 2020

AbstractFree radicals with reactive chemical properties can fight tumors without causing drug resistance. Reactive oxygen species (ROS) has been widely used for cancer treatment, but regrettably, the common O2 and H2O2 deficiency in tumors sets a severe barrier for sufficient ROS production, leading to unsatisfactory anticancer outcomes. Here, we construct a chlorine radical (.Cl) nano‐generator with SiO2‐coated upconversion nanoparticles (UCNPs) on the inside and Ag0/AgCl hetero‐dots on the outside. Upon near‐infrared (NIR) light irradiation, the short‐wavelength emission UCNP catalyzes .Cl generation from Ag0/AgCl with no dependence on O2/H2O2. .Cl with strong oxidizing capacity and nucleophilicity can attack biomolecules in cancer cells more effectively than ROS. This .Cl stress treatment will no doubt broaden the family of oxidative stress‐induced antitumor strategies by using non‐oxygen free radicals, which is significant in the development of new anticancer agents.
Mechanical‐Bending‐Induced Fluorescence Enhancement in Plastically Flexible Crystals of a GFP Chromophore Analogue
Authors: Bhattacharya Biswajit , Roy Debjit , Dey Somnath , Puthuvakkal Anisha , Bhunia Surojit , Mondal Saikat , Chowdhury Rituparno , Bhattacharya Manjima , Mandal Mrinal , Manoj Kochunnoonny , Mandal Prasun K. , Reddy C. Malla 
Published: July 2020

AbstractSingle crystals of optoelectronic materials that respond to external stimuli, such as mechanical, light, or heat, are immensely attractive for next generation smart materials. Here we report single crystals of a green fluorescent protein (GFP) chromophore analogue with irreversible mechanical bending and associated unusual enhancement of the fluorescence, which is attributed to the strained molecular packing in the perturbed region. Soft crystalline materials with such fluorescence intensity modulations occurring in response to mechanical stimuli under ambient pressure conditions will have potential implications for the design of technologically relevant tunable fluorescent materials.
Electroreduction of Carbon Dioxide in Metallic Nanopores through a Pincer Mechanism
Authors: Feng Yi , Cheng Chuan‐Qi , Zou Cheng‐Qin , Zheng Xue‐Li , Mao Jing , Liu Hui , Li Zhe , Dong Cun‐Ku , Du Xi‐Wen 
Published: July 2020

AbstractMetallic catalysts with nanopores are advantageous on improving both activity and selectivity, while the reason behind that remains unclear all along. In this work, porous Zn nanoparticles (P‐Zn) were adopted as a model catalyst to investigate the catalytic behavior of metallic nanopores. In situ X‐ray absorption spectroscopy, in situ Fourier transform infrared spectroscopy, and density functional theory (DFT) analyses reveal that the concave surface of nanopores works like a pincer to capture and clamp CO2 and H2O precursors simultaneously, thus lowering the energy barriers of CO2 electroreduction. Resultantly, the pincer mechanism endows P‐Zn with a high Faradic efficiency (98.1 %) towards CO production at the potential of −0.95 V vs. RHE. Moreover, DFT calculation demonstrates that Co and Cu nanopores exhibit the pincer behavior as well, suggesting that this mechanism is universal for metallic nanopores.
Iodine‐Transfer Polymerization (ITP) of Ethylene and Copolymerization with Vinyl Acetate
Authors: Wolpers A. , Baffie F. , Verrieux L. , Perrin L. , Monteil V. , D'Agosto F. 
Published: July 2020

AbstractControlled radical polymerization of ethylene using different commercially available, cheap, and non‐toxic iodo alkyls is performed by iodine transfer polymerization (ITP) under mild conditions (≤100 °C and ≤200 bar). The formed well‐defined iodo end‐capped polyethylene (PE−I) species is very stable upon storage. Narrow molar‐mass distributions (dispersities around 1.6) were obtained up to number average molar masses of 7300 g mol−1. The ethylene copolymerization by ITP (ITcoP) with vinyl acetate allowed to form a broad range of poly(ethylene‐co‐vinyl acetate) (EVA) containing from 0 to 85 mol % of VAc unit. In addition, EVA‐b‐PE block copolymers or EVA‐b‐EVA gradient block copolymers with different content of VAc in the blocks were obtained for the first time using ITP. Finally, reactivity trends were explored by a theoretical mechanistic study. This highly versatile synthetic platform provides a straightforward access to a diverse range of well‐defined PE based polymer materials.
Identifying a Real Catalyst of [NiFe]‐Hydrogenase Mimic for Exceptional H2 Photogeneration
Authors: Wang Xu‐Zhe , Meng Shu‐Lin , Xiao Hongyan , Feng Ke , Wang Yang , Jian Jing‐Xin , Li Xu‐Bing , Tung Chen‐Ho , Wu Li‐Zhu 
Published: July 2020

AbstractInspired by the natural [NiFe]‐H2ase, we designed mimic 1, (dppe)Ni(μ‐pdt)(μ‐Cl)Ru(CO)2Cl to realize effective H2 evolution under photocatalytic conditions. However, a new species 2 was captured in the course of photo‐, electro‐, and chemo‐ one‐electron reduction. Experimental studies of in situ IR spectroscopy, EPR, NMR, X‐ray absorption spectroscopy, and DFT calculations corroborated a dimeric structure of 2 as a closed‐shell, symmetric structure with a RuI center. The isolated dimer 2 showed the real catalytic role in photocatalysis with a benchmark turnover frequency (TOF) of 1936 h−1 for H2 evolution, while mimic 1 worked as a pre‐catalyst and evolved H2 only after being reduced to 2. The remarkably catalytic activity and unique dimer structure of 2 operated in photocatalysis unveiled a broad research prospect in hydrogenases mimics for advanced H2 evolution.
Unveiling the Activity and Stability Origin of BiVO4 Photoanodes with FeNi Oxyhydroxides for Oxygen Evolution
Authors: Zhang Beibei , Huang Xiaojuan , Zhang Yan , Lu Gongxuan , Chou Lingjun , Bi Yingpu 
Published: July 2020

AbstractUnderstanding the origin of formation and active sites of oxygen evolution reaction (OER) cocatalysts is highly required for solar photoelectrochemical (PEC) devices that generate hydrogen efficiently from water. Herein, we employed a simple pH‐modulated method for in situ growth of FeNi oxyhydroxide ultrathin layers on BiVO4 photoanodes, resulting in one of the highest currently known PEC activities of 5.8 mA cm−2 (1.23 VRHE, AM 1.5 G) accompanied with an excellent stability. More importantly, both comparative experiments and density functional theory (DFT) studies clearly reveal that the selective formation of Bi−O−Fe interfacial bonds mainly contributes the enhanced OER activities, while the construction of V−O−Ni interfacial bonds effectively restrains the dissolution of V5+ ions and promotes the OER stability. Thereby, the synergy between iron and nickel of FeNi oxyhydroxides significantly improved the PEC water oxidation properties of BiVO4 photoanodes.
Intense Red‐Blue Luminescence Based on Superfine Control of Metal–Metal Interactions for Self‐Assembled Platinum(II) Complexes
Authors: Saito Daisuke , Ogawa Tomohiro , Yoshida Masaki , Takayama Junichi , Hiura Satoshi , Murayama Akihiro , Kobayashi Atsushi , Kato Masako 
Published: July 2020

AbstractA series of assembled PtII complexes comprising N‐heterocyclic carbene and cyanide ligands was constructed using different substituent groups, [Pt(CN)2(R‐impy)] (R‐impyH+=1‐alkyl‐3‐(2‐pyridyl)‐1H‐imidazolium, R=Me (Pt‐Me), Et (Pt‐Et), iPr (Pt‐iPr), and tBu (Pt‐tBu)). All the complexes exhibited highly efficient photoluminescence with an emission quantum yield of 0.51–0.81 in the solid state at room temperature, originating from the triplet metal‐metal‐to‐ligand charge transfer (3MMLCT) state. Their emission colors cover the entire visible region from red for Pt‐Me to blue for Pt‐tBu. Importantly, Pt‐tBu is the first example that exhibits blue 3MMLCT emission. The 3MMLCT emission was proved and characterized based on the temperature dependences of the crystal structures and emission properties. The wide‐range color tuning of luminescence using the 3MMLCT emission presents a new strategy of superfine control of the emission color.
Spatially Responsive Multicolor Lanthanide‐MOF Heterostructures for Covert Photonic Barcodes
Authors: Gao Zhenhua , Xu Baoyuan , Zhang Tongjin , Liu Zhen , Zhang Weiguang , Sun Xun , Liu Yang , Wang Xue , Wang Zifei , Yan Yongli , Hu Fengqin , Meng Xiangeng , Zhao Yong Sheng 
Published: July 2020

AbstractMicro/nanoscale photonic barcodes based on multicolor luminescent segmented heterojunctions hold potential for applications in information security. However, such multicolor heterojunctions reported thus far are exclusively based on static luminescent signals, thus restricting their application in advanced confidential information protection. Reported here is a strategy to design responsive photonic barcodes with heterobimetallic (Tb3+/Eu3+) metal—organic framework multicolor heterostructures. The spatial colors could be precisely controlled by thermally manipulating the energy‐transfer process between the two lanthanides, thus achieving responsive covert photonic barcodes. Also demonstrated is that spatially resolved responsive barcodes with multi‐responsive features could be created in a single heterostructure. These findings offer unique opportunities to purposely design highly integrated responsive microstructures and smart devices toward advanced anti‐counterfeiting applications.