bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of Software for Image Analysis and Calibration of Automated Rain Simulator
Authors: Bonfim-Silva Edna Maria , Araújo da Silva Tonny José , De Souza Alves Rackel Danielly , Vieira José Jefferson 
Published: April 2019

Aims: To calibrate and evaluate a rain simulator, with automatic operation, as well as determine the average size, the effect of the height of the equipment (2.12; 2.42 and 2.72 m) and of the oscillations of the spray nozzle of the rain simulator (21, 29 and 40 oscillations min-1). Finally, to test and to compare the results of the count of drops by the software of analysis and processing of images Able Image Analyser, ImageJ and Safira.
Study Design: The experimental design was completely randomized, with 3 x 3 x 3 factorial scheme, with three repetitions (81 units).
Place and Duration of Study: The research was conducted in a greenhouse, in the municipality of Rondonópolis, Mato Grosso, located geographically at latitude 16°27'49 "S, longitude 550°34'47" W.
Methodology: For the calibration tests, the rainfall simulator was adjusted according to the heights (2.12; 2.42 and 2.72 m) and oscillations (21, 29 and 40 oscillations min-1), followed by trays with a uniform layer of wheat flour, 2 cm thick, where the simulated raindrops were sprayed for a period of 4 seconds. From this procedure, the drops were dried, sifted, weighed and counted. Droplet analysis was performed using three image analysis software Able Image Analyser, ImageJ and Safira.
Results: The softwares Able Image Analyzer, ImageJ and Safira did not show any significant difference in counting of the number of drops. It was observed that in the oscillation factor in setting that if gets drops of larger size (21 oscillations min-1) the terminal velocity is also greater. In the height factor of the equipment, the drops presented larger sizes at the lower height (2.12 m). There are larger drops, higher terminal velocity as the height of the spray nozzle decreases, and higher kinetic energy value per unit area as the height of the spray nozzle increases. The range of drop sizes observed was 1.2 mm to 3.1 mm.
Conclusion: Although the software does not present significant differences, the ImageJ software proved to be more suitable as a research tool, since it has the license of free use and greater ease of use. Satisfactory results were obtained compared to natural rains in more than one combination of height and swings.
Starvation-induced Changes in Memory Sensitization, Habituation and Psychosomatic Responses
Authors: Ilochi O. N. , Kolawole T. A. , Oluwatayo B. O. , Chuemere A. N. 
Published: April 2019

Starvation is a global challenge. Nutritional status of an organism may influence its psychosocial behavior and other nervous system processes like motor responses and its ability to learn and memorize. This study determined the impact of starvation-induced stress on memory sensitization, habituation and psychosomatic responses in an experimental animal design. 25 wistar rats were randomly sampled and grouped into 1-control, 2- feed after 6 hours deprivation, 3-feed after12 hours deprivation, 4-feed after 18 hours deprivation and 5-feed after 24 hours deprivation. Behavioral tests carried out included the multiple maze tests and elevated plus maze test. Grip strength test was performed to determine neuromuscular response and endurance in all groups. Biochemical investigation of brain stress markers was done on the last day of the study. There was a significant (P≤0.05) enhancement in memory processes and anxiolytic behavior after 6 hours feed deprivation. An increase in antioxidants after 6 hours feed deprivation was suspected to be a compensatory response. A progressive decrease in memory facilitation, anxiolytic behavior and muscular strength was reported after 12, 18 and 24 hours feed deprivation. The increase in habituation and decrease in psychosomatic response was observed and appreciated as the duration of feed deprivation was increased. This study provided evidence about a possible link between memory processes and stress-related alterations in calcium, magnesium and nitric oxide. Starvation may impair learning, memory and motor responses, but this tendency is dependent on the extent of feed deprivation and nutrient depletion.
Gradient Photothermal Field for Precisely Directing Cell Sheet Detachment
Authors: Jing Jiange , Chen Shuangshuang , Lu Qinghua 
Published: April 2019

AbstractDue to the remaining intact intercellular interactions, cell sheets play increasing roles in biomedical fields. Recently, spatiotemporal control of cell sheets has become an urgent requirement in the context of precise surgery. Here, the development of a gradient photothermal biointerface for precisely directing cell sheet detachment through quantitatively regulating the dissociation rate of collagen is reported. This novel and facile method shows great potential for application in precise regenerative medicine.
Controlled Fabrication of 3D Chiral Microwrinkles via Asymmetrical and Biaxial Bucklings
Authors: Hwang Myonghoo , Kim Changho , Kim Jinwoo , Son Jeong Gon , Yeom Bongjun 
Published: April 2019

AbstractNano‐ and microsized chiral materials are receiving significant attention because of their unique characteristics, which include chiroptical activities and enantioselective interactions with living materials. However, the realization of chiral morphologies in such small‐scale materials has been an issue because of the complicated fabrication methods and limited material selection. In this study, a facile and reproducible method is developed for fabricating 3D chiral microwrinkles with twisted shapes by asymmetric and biaxial buckling. Soft polydimethylsiloxane (PDMS) substrates are asymmetrically stretched with angled biaxial strains and exposed to UV/ozone to prepare hard silica layers on top of the PDMS substrates to induce microwrinkles. The chiral shapes are controlled by changing the angle (θ) between the two strain axes and the UV/ozone exposure times (t1, t2) in each stage of buckling. The 3D chiral microwrinkles are shaped like “fusilli pasta” and occupy an area of 1.5 cm × 1.5 cm. The patterned area can be easily scaled, and no innate chiral biomaterial is necessary. This method could be widely extended to the fabrication of diverse types of chiral materials for advanced optical and bio‐applications.
Hole Transport Materials Based on 6,12‐Dihydroindeno[1,2‐b]fluorine with Different Periphery Groups: A New Strategy for Dopant‐Free Perovskite Solar Cells
Authors: Liu Fan , Wu Fei , Tu Zongxiao , Liao Qiuyan , Gong Yanbin , Zhu Linna , Li Qianqian , Li Zhen 
Published: April 2019

AbstractAlthough several hole‐transporting materials (HTMs) have been designed to obtain perovskite solar cells (PSCs) devices with high performance, the dopant‐free HTMs for efficient and stable PSCs remain rare. Herein, a rigid planar 6,12‐dihydroindeno[1,2‐b]fluorine (IDF) core with different numbers of bulky periphery groups to construct dopant‐free HTMs of IDF‐SFXPh, IDF‐DiDPA, and IDF‐TeDPA is modified. Thanks to the contributions of the planar IDF core and the twisted SFX periphery groups, the dopant‐free IDF‐SFXPh‐based PSCs device achieves a device performance of 17.6%, comparable to the doped 2,2′,7,7′‐tetrakis(N,N‐di‐p‐methoxyphenylamine)‐9,9′‐spirobifluorene (spiro‐OMeTAD)‐based device (17.6%), with much enhanced device stability under glovebox and ambient conditions.
Zr‐Doped Indium Oxide (IZRO) Transparent Electrodes for Perovskite‐Based Tandem Solar Cells
Authors: Aydin Erkan , De Bastiani Michele , Yang Xinbo , Sajjad Muhammad , Aljamaan Faisal , Smirnov Yury , Hedhili Mohamed Nejib , Liu Wenzhu , Allen Thomas G. , Xu Lujia , Van Kerschaver Emmanuel , Morales‐Masis Monica , Schwingenschlögl Udo , De Wolf Stefaan 
Published: April 2019

AbstractParasitic absorption in transparent electrodes is one of the main roadblocks to enabling power conversion efficiencies (PCEs) for perovskite‐based tandem solar cells beyond 30%. To reduce such losses and maximize light coupling, the broadband transparency of such electrodes should be improved, especially at the front of the device. Here, the excellent properties of Zr‐doped indium oxide (IZRO) transparent electrodes for such applications, with improved near‐infrared (NIR) response, compared to conventional tin‐doped indium oxide (ITO) electrodes, are shown. Optimized IZRO films feature a very high electron mobility (up to ≈77 cm2 V−1 s−1), enabling highly infrared transparent films with a very low sheet resistance (≈18 Ω □−1 for annealed 100 nm films). For devices, this translates in a parasitic absorption of only ≈5% for IZRO within the solar spectrum (250–2500 nm range), to be compared with ≈10% for commercial ITO. Fundamentally, it is found that the high conductivity of annealed IZRO films is directly linked to promoted crystallinity of the indium oxide (In2O3) films due to Zr‐doping. Overall, on a four‐terminal perovskite/silicon tandem device level, an absolute 3.5 mA cm−2 short‐circuit current improvement in silicon bottom cells is obtained by replacing commercial ITO electrodes with IZRO, resulting in improving the PCE from 23.3% to 26.2%.
Superamphiphobic Porous Structure: Design and Implementation
Authors: Li Fang , Du Miao , Xiao Jianliang , Cao Can , Xia Xueke , Xie Jian , Zhao Xinbing , Song Yihu , Zheng Qiang 
Published: April 2019

AbstractPorous materials with an excellent super‐repellency exist in many applications in life and industry, and their preparation is convenient and cost effective. It would be advantageous to fabricate super‐repellent porous materials. However, because of a lack of understanding of the detailed relationship between structural features and super‐repellency, it is difficult to prepare porous materials with a superamphiphobicity. Based on a theoretical analysis and the discussion of several porous structures' repellant behaviors, the criteria for fabricating super‐repellent porous materials are proposed as: (1) the most appropriate pore size being tens of micrometers to ≈100–200 µm; (2) a larger pore height; (3) a smaller porous‐network thickness; and (4) an appropriate adequate secondary microscopic structure that favors the effective pinning of a gas–liquid–solid three‐phase contact line. According to the four criteria, an optimized superamphiphobic porous material is achieved, which is a dopamine/redox graphene‐oxide‐assembled microscale porous material, which displays a super‐repellency for droplets with a surface tension of 72.8–20 mN m−1. By using the dopamine/graphene‐assembled microscale porous material, a low gate voltage (500 V) for water impaling is acquired.
SBA‐15/POSS‐Imidazolium Hybrid as Catalytic Nanoreactor: the role of the Support in the Stabilization of Palladium Species for C−C Cross Coupling Reactions.
Authors: Calabrese Carla , Campisciano Vincenzo , Siragusa Fabiana , Liotta Leonarda F. , Aprile Carmela , Gruttadauria Michelangelo , Giacalone Francesco 
Published: April 2019

AbstractSupported imidazolium modified polyhedral oligomeric silsesquioxanes (POSS) on SBA‐15 have been used as platform for Pd(II) species. The so‐obtained material was firstly characterized by means of TGA, solid state NMR, TEM, XPS, SAXS, porosimetry and ICP‐OES and it was successfully tested as pre‐catalyst in C−C cross couplings, namely Suzuki‐Miyaura and Heck reactions. In both cases, the solid proved to be highly efficient and easily recoverable from the reaction mixture. The recyclability was verified for up to seven cycles without showing any activity decrease. Interestingly, only Pd(II) was detected in the reused catalyst in the Heck reaction. Therefore, the versatility of the material was investigated by using various aryl halides. Our palladium nanocomposite was able to promote both Suzuki and Heck reactions down to 0.0007 mol% showing outstanding turnover frequency (TOF) values of 114,286 and 32,381 h−1, respectively. Comparison with the palladium catalyst on SiO2‐POSS‐imidazolium support showed interesting differences in terms of stabilization of Pd species and recyclability. The excellent outcome of the reactions could be ascribed to the textural properties of the SBA‐15 support and the presence of the imidazolium‐POSS nanocage within the pores of SBA‐15, that worked as a sort of nanoreactor.magnified image
Macrophages‐Triggered Sequential Remodeling of Endothelium‐Interstitial Matrix to Form Pre‐Metastatic Niche in Microfluidic Tumor Microenvironment
Authors: Kim Hyunho , Chung Hyewon , Kim Jaehoon , Choi Dong‐Hee , Shin Yoojin , Kang Yong Guk , Kim Beop‐Min , Seo Sang‐Uk , Chung Seok , Seok Seung Hyeok 
Published: April 2019

AbstractThe primed microenvironment of future metastatic sites, called the pre‐metastatic niche, is a prerequisite for overt metastasis. However, a mechanistic understanding of the contributions of recruited cells to the niche is hindered by complex in vivo systems. Herein, a microfluidic platform that incorporates endothelial cells and extracellular matrix (ECM) scaffolds is developed, and the distinct role of recruited monocytes and macrophages in establishing pre‐metastatic niches is delineated. It is observed that monocyte‐derived matrix metalloproteinase 9 facilitates cancer cell extravasation through destruction of endothelial tight junctions. Furthermore, subsequent cancer cell invasiveness is significantly enhanced. Close examination of ECM structures reveals that cancer cells move within characteristic “microtracks” generated by macrophages, suggesting that macrophages could serve as a compensatory mechanism for the reduced migratory capacity of cancer cells. Thus, the first evidence of monocyte/macrophage‐induced remodeling is shown, and these findings will open up new horizons for improving characterization of the pre‐metastatic niche and corresponding immunotherapies.
A New Mode of Chemical Reactivity for Metal‐Free Hydrogen Activation by Lewis Acidic Boranes
Authors: Bennett Elliot L. , Lawrence Elliot J. , Blagg Robin J. , Mullen Anna S. , MacMillan Fraser , Ehlers Andreas W. , Scott Daniel J. , Sapsford Joshua S. , Ashley Andrew E. , Wildgoose Gregory G. , Slootweg J. Chris 
Published: April 2019

AbstractWe herein explore whether tris(aryl)borane Lewis acids are capable of cleaving H2 outside of the usual Lewis acid/base chemistry described by the concept of frustrated Lewis pairs (FLPs). Instead of a Lewis base we use a chemical reductant to generate stable radical anions of two highly hindered boranes: tris(3,5‐dinitromesityl)borane and tris(mesityl)borane. NMR spectroscopic characterization reveals that the corresponding borane radical anions activate (cleave) dihydrogen, whilst EPR spectroscopic characterization, supported by computational analysis, reveals the intermediates along the hydrogen activation pathway. This radical‐based, redox pathway involves the homolytic cleavage of H2, in contrast to conventional models of FLP chemistry, which invoke a heterolytic cleavage pathway. This represents a new mode of chemical reactivity for hydrogen activation by borane Lewis acids.
Formation of Twinned Graphene Polycrystals
Authors: Dong Jichen , Geng Dechao , Liu Fengning , Ding Feng 
Published: April 2019

AbstractLiquid metals have been widely used as substrates to grow graphene and other 2D materials. On a homogeneous and isotropic liquid surface, a polycrystalline 2D material is formed by coalescence of many randomly nucleated single‐crystal islands, and as a result, the domains in a polycrystal are expected to be randomly aligned. Here, we report the unexpected finding that only 30°‐twinned graphene polycrystals are grown on a liquid Cu surface. Atomic simulations confirm that the unique domain alignment in graphene polycrystals is due to the free rotation of graphene islands on the liquid Cu surface and the highly stable 30°‐grain boundaries in graphene. In‐depth analysis predicts 30 types of possible 30°‐twinned graphene polycrystals and 27 of them are observed. The revealed formation mechanism of graphene polycrystals on a liquid Cu surface deepens our fundamental understanding on polycrystal growth and could serve as a guideline for the controlled synthesis of 2D materials.
Electrochemical Monitoring of ROS/RNS Homeostasis Within Individual Phagolysosomes Inside Single Macrophages
Authors: Zhang Xin‐Wei , Oleinick Alexander , Jiang Hong , Liao Quan‐Lan , Qiu Quan‐Fa , Svir Irina , Liu Yan‐Ling , Amatore Christian , Huang Wei‐Hua 
Published: April 2019

AbstractThe existence of a homeostatic mechanism regulating reactive oxygen/nitrogen species (ROS/RNS) amounts inside phagolysosomes has been invoked to account for the efficiency of this process but could not be unambiguously documented. Now, intracellular electrochemical analysis with platinized nanowire electrodes (Pt‐NWEs) allowed monitoring ROS/RNS effluxes with sub‐millisecond resolution from individual phagolysosomes impacting onto the electrode inserted inside a living macrophage. This shows for the first time that the consumption of ROS/RNS by their oxidation at the nanoelectrode surface stimulates the production of significant ROS/RNS amounts inside phagolysosomes. These results establish the existence of the long‐postulated ROS/RNS homeostasis and allows its kinetics and efficiency to be quantified. ROS/RNS concentrations may then be maintained at sufficiently high levels for sustaining proper pathogen digestion rates without endangering the macrophage internal structures.
Tautomer‐Specific Resonant Photoelectron Imaging of Deprotonated Cytosine Anions
Authors: Zhu Guo‐Zhu , Qian Chen‐Hui , Wang Lai‐Sheng 
Published: April 2019

AbstractTautomers of the nucleobases play fundamental roles in spontaneous mutations of DNA. Tautomers of neutral cytosine have been studied in the gas phase, but much less is known about charged species. Here, we report the observation and characterization of three tautomers of deprotonated cytosine anions, [trans‐keto‐amino‐N3H‐H8b] (tKAN3H8b−), [cis‐keto‐amino‐N3H‐H8a] (cKAN3H8a−) and [keto‐amino‐H] (KAN1−), produced by electrospray ionization. Excited dipole‐bound states (DBSs) are uncovered for the three anions by photodetachment spectroscopy. Excitations to selected DBS vibrational levels of cKAN3H8a− and tKAN3H8b− yield tautomer‐specific resonant photoelectron spectra. The current study provides further insight into tautomerism of cytosine and suggests a new method to study the tautomers of nucleobases using electrospray ionization and anion spectroscopy.
Der Naturstoff Elegaphenon verstärkt antibiotische Effekte gegen Pseudomonas aeruginosa
Authors: Zhao Weining , Cross Ashley R. , Crowe‐McAuliffe Caillan , Weigert‐Munoz Angela , Csatary Erika E. , Solinski Amy E. , Krysiak Joanna , Goldberg Joanna B. , Wilson Daniel N. , Medina Eva , Wuest William M. , Sieber Stephan A. 
Published: April 2019

AbstractNaturstoffe sind eine ergiebige Quelle für Antibiotika, die vielfältige zelluläre Zielstrukturen adressieren. Die Erforschung ihrer Zielproteine mittels chemischer Proteomik wird häufig durch das Einbringen sterisch anspruchsvoller photoreaktiver Gruppen erschwert. Hier verwenden wir Elegaphenon, ein weitestgehend uncharakterisiertes Naturstoffantibiotikum mit einem nativen Benzophenongrundgerüst für affinitätsbasiertes Protein Profiling (AfBPP) in grampositiven und gramnegativen Bakterien. In dieser Studie wurde das Naturstoffgerüst alkinyliert und als Sonde verwendet wodurch es gelungen ist, den Transkriptionsregulator AlgP als biologisches Angriffsziel aufzudecken. Weiterhin wurden durch Proteomprofiling einer Pseudomoas aeruginosa AlgP‐Transposonmutanten einzigartige Erkenntnisse über den Wirkmechanismus gewonnen. Elegaphenon verstärkt die Eliminierung intrazellulärer P. aeruginosa in Makrophagen bei Behandlung mit dem Fluorchinolonantibiotikum Norfloxacin in subinhibitorischen Konzentrationen.
The Structure of the Elusive Urease–Urea Complex Unveils the Mechanism of a Paradigmatic Nickel‐Dependent Enzyme
Authors: Mazzei Luca , Cianci Michele , Benini Stefano , Ciurli Stefano 
Published: April 2019

AbstractUrease, the most efficient enzyme known, contains an essential dinuclear NiII cluster in the active site. It catalyzes the hydrolysis of urea, inducing a rapid pH increase that has negative effects on human health and agriculture. Thus, the control of urease activity is of utmost importance in medical, pharmaceutical, and agro‐environmental applications. All known urease inhibitors are either toxic or inefficient. The development of new and efficient chemicals able to inhibit urease relies on the knowledge of all steps of the catalytic mechanism. The short (microseconds) lifetime of the urease–urea complex has hampered the determination of its structure. The present study uses fluoride to substitute the hydroxide acting as the co‐substrate in the reaction, preventing the occurrence of the catalytic steps that follow substrate binding. The 1.42 Å crystal structure of the urease–urea complex, reported here, resolves the enduring debate on the mechanism of this metalloenzyme.
Acyl Fluorides in Late‐Transition‐Metal Catalysis
Authors: Ogiwara Yohei , Sakai Norio 
Published: April 2019

AbstractIn this Review, we summarize the current state of the art in late‐transition‐metal‐catalyzed reactions of acyl fluorides, covering both their synthesis and further transformations. In organic reactions, the relationship between stability and reactivity of the starting substrates is usually characterized by a trade‐off. Yet, acyl fluorides display a very good balance between these properties, which is mostly due to their moderate electrophilicity. Thus, acyl fluorides (RCOF) can be used as versatile building blocks in transition‐metal‐catalyzed reactions, for example, as an “RCO” source in acyl coupling reactions, as an “R” source in decarbonylative coupling reactions, and as an “F” source in fluorination reactions. Starting from the cleavage of the acyl C−F bond in acyl fluorides, various transformations are accessible, including C−C, C−H, C−B, and C−F bond‐forming reactions that are catalyzed by transition‐metal catalysts that contain the Group 9–11 metals Co, Rh, Ir, Ni, Pd, or Cu.
Catalytic Enantioselective Intermolecular Benzylic C(sp3)−H Amination
Authors: Nasrallah Ali , Boquet Vincent , Hecker Alexandra , Retailleau Pascal , Darses Benjamin , Dauban Philippe 
Published: April 2019

AbstractA practical general method for asymmetric intermolecular benzylic C(sp3)−H amination has been developed by combining the pentafluorobenzyl sulfamate PfbsNH2 with the chiral rhodium(II) catalyst Rh2(S‐tfptad)4. Various substrates can be used as limiting components and converted to benzylic amines with excellent yields and high levels of enantioselectivity. Additional key features for the reaction are the low catalyst loading and the ability to remove the Pfbs group under mild conditions to give NH‐free benzylic amines.