bluuebunny/crossref_metadata_2025_split huggingface dataset:
Segmentation errors and intertest reliability in automated and manually traced hippocampal volumes
Authors: Brinkmann Benjamin H. , Guragain Hari , Kenney‐Jung Daniel , Mandrekar Jay , Watson Robert E. , Welker Kirk M. , Britton Jeffrey W. , Witte Robert J. 
Published: September 2019

AbstractObjectiveTo rigorously compare automated atlas‐based and manual tracing hippocampal segmentation for accuracy, repeatability, and clinical acceptability given a relevant range of imaging abnormalities in clinical epilepsy.MethodsForty‐nine patients with hippocampal asymmetry were identified from our institutional radiology database, including two patients with significant anatomic deformations. Manual hippocampal tracing was performed by experienced technologists on 3T MPRAGE images, measuring hippocampal volume up to the tectal plate, excluding the hippocampal tail. The same images were processed using NeuroQuant and FreeSurfer software. Ten subjects underwent repeated manual hippocampal tracings by two additional technologists blinded to previous results to evaluate consistency. Ten patients with two clinical MRI studies had volume measurements repeated using NeuroQuant and FreeSurfer.ResultsFreeSurfer raw volumes were significantly lower than NeuroQuant (P < 0.001, right and left), and hippocampal asymmetry estimates were lower for both automatic methods than manual tracing (P < 0.0001). Differences remained significant after scaling volumes to age, gender, and scanner matched normative percentiles. Volume reproducibility was fair (0.4–0.59) for manual tracing, and excellent (>0.75) for both automated methods. Asymmetry index reproducibility was excellent (>0.75) for manual tracing and FreeSurfer segmentation and fair (0.4–0.59) for NeuroQuant segmentation. Both automatic segmentation methods failed on the two cases with anatomic deformations. Segmentation errors were visually identified in 25 NeuroQuant and 27 FreeSurfer segmentations, and nine (18%) NeuroQuant and six (12%) FreeSurfer errors were judged clinically significant.InterpretationAutomated hippocampal volumes are more reproducible than hand‐traced hippocampal volumes. However, these methods fail in some cases, and significant segmentation errors can occur.
A Single‐Electron Transistor Made of a 3D Topological Insulator Nanoplate
Authors: Jing Yumei , Huang Shaoyun , Wu Jinxiong , Meng Mengmeng , Li Xiaobo , Zhou Yu , Peng Hailin , Xu Hongqi 
Published: September 2019

AbstractQuantum confined devices of 3D topological insulators are proposed to be promising and of great importance for studies of confined topological states and for applications in low‐energy‐dissipative spintronics and quantum information processing. The absence of energy gap on the topological insulator surface limits the experimental realization of a quantum confined system in 3D topological insulators. Here, the successful realization of single‐electron transistor devices in Bi2Te3 nanoplates using state‐of‐the‐art nanofabrication techniques is reported. Each device consists of a confined central island, two narrow constrictions that connect the central island to the source and drain, and surrounding gates. Low‐temperature transport measurements demonstrate that the two narrow constrictions function as tunneling junctions and the device shows well‐defined Coulomb current oscillations and Coulomb‐diamond‐shaped charge‐stability diagrams. This work provides a controllable and reproducible way to form quantum confined systems in 3D topological insulators, which should greatly stimulate research toward confined topological states, low‐energy‐dissipative devices, and quantum information processing.
Universal Strategy for Efficient Electron Injection into Organic Semiconductors Utilizing Hydrogen Bonds
Authors: Fukagawa Hirohiko , Hasegawa Munehiro , Morii Katsuyuki , Suzuki Kazuma , Sasaki Tsubasa , Shimizu Takahisa 
Published: September 2019

AbstractMolecular n‐dopants that can lower the electron injection barrier between organic semiconductors and electrodes are essential in present‐day organic electronics. However, the development of stable molecular n‐dopants remains difficult owing to their low ionization potential, which generally renders them unstable. It is shown that the stable bases widely used in organic synthesis as catalysts can lower the electron injection barrier similar to that in conventional n‐doping in organic optoelectronic devices. In contrast to conventional n‐doping, which is based on the electron transfer from dopants with low ionization potential, the reduction of the injection barrier caused by adding bases is determined by the formation of hydrogen bonds between the hosts and the bases, providing energy‐level‐independent electron injection. The observation of the efficient electron injection induced by hydrogen bonding affords new perspectives on the method for controlling the behavior of electrons unique to organic semiconductors.
Controlled Design of a Robust Hierarchically Porous and Hollow Carbon Fiber Textile for High‐Performance Freestanding Electrodes
Authors: Li Quanxiang , Wang Jiemin , Liu Chao , Fakhrhoseini Seyed Mousa , Liu Dan , Zhang Liangzhu , Lei Weiwei , Naebe Minoo 
Published: September 2019

AbstractFor most carbon‐based materials, hierarchical porous structure including well‐defined macropores, mesopores, and micropores is commonly seen in 3D aerogels, monoliths, or some carbothermic natural biomass. However, because of the filiform character and long draw ratio, it is difficult to achieve such pore network as well as attain excellent mechanical performance in a 1D single carbon fiber system. To address this issue, an innovative hierarchical porous and hollow carbon textile (HPHCT) is developed via the “dynamic template (KOH, SiO2, and Al2O3) calcination” strategy. Unlike conventional one‐step activated carbonized fiber simply with meso or micropores, the fabricated textile generates honeycomb‐like macropores uniformly spreading on fiber surface. More importantly, the ultra‐lightweight yet flexible HPHCT is mechanically robust, superior to ordinary carbonized one. In addition, it delivers high capacitance of maximum 220 F g−1 as well as keeping long term stability with 100% retention after 10 000 cycles as freestanding electrodes in supercapacitor. Meanwhile, the all‐solid integrated symmetric HPHCT supercapacitors demonstrates its high potential in powering electronics for wearable energy storage application.
Does Applicant Gender Have an Effect on Standardized Letters of Evaluation Obtained During Medical Student Emergency Medicine Rotations?
Authors: Andrusaitis Jessica , Clark Clelia , Saadat Soheil , Billimek John , Paradise Sara , Wray Alisa , Wiechmann Warren , Toohey Shannon , Boysen‐Osborn Megan 
Published: September 2019

AbstractBackgroundThe standardized letter of evaluation (SLOE) in emergency medicine (EM) is one of the most important items in a student's application to EM residency and replaces narrative letters of recommendation. The SLOE ranks students into quantile categories in comparison to their peers for overall performance during an EM clerkship and for their expected rank list position. Gender differences exist in several assessment methods in undergraduate and graduate medical education. No authors have recently studied whether there are differences in the global assessment of men and women on the SLOE.ObjectivesThe objective of this study was to determine if there is an effect of student gender on the outcome of a SLOE.MethodsThis was a retrospective observational study examining SLOEs from applications to a large urban, academic EM residency program from 2015 to 2016. Composite scores (CSs), comparative rank scores (CRSs), and rank list position scores (RLPSs) on the SLOE were compared for female and male applicants using Mann‐Whitney U‐test.ResultsFrom a total 1,408 applications, 1,038 applicants met inclusion criteria (74%). We analyzed 2,092 SLOEs from these applications. Female applicants were found to have slightly lower and thus better CRSs, RLPSs, and CSs than men. The mean CRS for women was 2.27 and 2.45 for men (p < 0.001); RLPS for women was 2.32 and 2.52 for men (p < 0.001) and CS was 4.59 for women and 4.97 for men (p < 0.001).ConclusionsFemale applicants have somewhat better performance on the EM SLOE than their male counterparts.
Understanding how deficit discourses work against implementing participatory approaches in Australian Indigenous policy
Authors: Brown Prudence R. 
Published: September 2019

AbstractOne of the few things that everyone can agree on with respect to Australian Indigenous policy is that repeated government experiments aimed at improving Indigenous well‐being in Australia and particularly in remote Australia have failed. Outcomes remain poor and are, if anything, deteriorating in a number of areas. Critics have characterised the history of Indigenous policy as a series of failed policy experiments. The latest experiment in the quest to improve outcomes involves attempts to move away from the usual rational‐technical approaches, toward participatory approaches or “partnerships”. However, governments are struggling to implement these innovations. Self‐evidently, the Closing the Gap policy is grounded in deficit discourse. This paper examines how this discourse works within the existing Indigenous policy world to create possibly irreconcilable tensions with attempts to introduce participatory approaches. It does this using Logics of Critical Explanation, an interpretive method which allows us to understand how policy actors work within an existing policy world to either replace or augment their norms, values and ideologies to work in the new ways that are asked of them, or to resist innovation and revert to the status quo.
Enantioselective Iridium‐Catalyzed Allylation of Acetylenic Ketones via 2‐Propanol‐Mediated Reductive Coupling of Allyl Acetate: C14‐C23 of Pladienolide D
Authors: Brito Gilmar A. , Jung Woo‐Ok , Yoo Minjin , Krische Michael J. 
Published: September 2019

AbstractHighly enantioselective catalytic reductive coupling of allyl acetate with acetylenic ketones occurs in a chemoselective manner in the presence of aliphatic or aromatic ketones. This method was used to construct C14‐C23 of pladienolide D in half the steps previously required.
Identifying Multinuclear Organometallic Intermediates in On‐Surface [2+2] Cycloaddition Reactions
Authors: Zhang Ran , Xia Bowen , Xu Hu , Lin Nian 
Published: September 2019

AbstractWe investigate the on‐surface [2+2] cycloaddition reaction of 2,3,6,7,10,11‐hexabromotriphenylene (HBTP) on Ag(111), Cu(111), Au(111), and Cu‐dosed Au(111) surfaces using STM and DFT simulation focusing on the organometallic intermediates. The fully debrominated HBTP molecules form an organo‐silver framework on Ag(111) and an organo‐copper framework on Cu(111), both incorporating multinuclear metal adatom clusters. The organo‐silver framework is converted into porous covalent networks via [2+2] cycloaddition above 240 °C. In contrast, the organo‐copper framework is very stable and does not undergo [2+2] cycloaddition even at 300 °C. On Au(111), no organo‐gold intermediate of [2+2] cycloaddition is observed. After loading Cu onto Au(111), the partially debrominated HBTP molecules bind to Cu adatom dimers to form multinuclear organo‐copper complexes at 100 °C which undergo [2+2] cycloaddition at 140 °C. This study shows that the choice of surface can direct the reaction pathway.
A High‐Valent Manganese(IV)–Oxo–Cerium(IV) Complex and Its Enhanced Oxidizing Reactivity
Authors: Karmalkar Deepika G. , Sankaralingam Muniyandi , Seo Mi Sook , Ezhov Roman , Lee Yong‐Min , Pushkar Yulia N. , Kim Won‐Suk , Fukuzumi Shunichi , Nam Wonwoo 
Published: September 2019

AbstractA mononuclear nonheme manganese(IV)–oxo complex binding the Ce4+ ion, [(dpaq)MnIV(O)]+–Ce4+ (1‐Ce4+), was synthesized by reacting [(dpaq)MnIII(OH)]+ (2) with cerium ammonium nitrate (CAN). 1‐Ce4+ was characterized using various spectroscopic techniques, such as UV/Vis, EPR, CSI‐MS, resonance Raman, XANES, and EXAFS, showing an Mn−O bond distance of 1.69 Å with a resonance Raman band at 675 cm−1. Electron‐transfer and oxygen atom transfer reactivities of 1‐Ce4+ were found to be greater than those of MnIV(O) intermediates binding redox‐inactive metal ions (1‐Mn+). This study reports the first example of a redox‐active Ce4+ ion‐bound MnIV‐oxo complex and its spectroscopic characterization and chemical properties.
H2‐Acceptorless Dehydrogenative Boration and Transfer Boration of Alkenes Enabled by Zirconium Catalyst
Authors: Shi Xiaonan , Li Sida , Wu Lipeng 
Published: September 2019

AbstractThe first example of an efficient and direct dehydrogenative boration of alkenes for vinyl boronate ester synthesis was achieved using a zirconium catalyst. Our methodology avoids using precious transition metals, additional hydrogen acceptors, high temperatures, and long reaction times, which were required to overcome the reducing ability of borane, to give alkyl boronate esters. Detailed mechanistic studies revealed a reversible reaction pathway and further suggested applying the zirconium complex as a “shuttle catalyst” for transfer boration, which thus sidesteps the use of relatively sensitive borane.
Lithium–Sulfur Batteries under Lean Electrolyte Conditions: Challenges and Opportunities
Authors: Zhao Meng , Li Bo‐Quan , Peng Hong‐Jie , Yuan Hong , Wei Jun‐Yu , Huang Jia‐Qi 
Published: September 2019

AbstractThe development of energy‐storage devices has received increasing attention as a transformative technology to realize a low‐carbon economy and sustainable energy supply. Lithium–sulfur (Li–S) batteries are considered to be one of the most promising next‐generation energy‐storage devices due to their ultrahigh energy density. Despite the extraordinary progress in the last few years, the actual energy density of Li–S batteries is still far from satisfactory to meet the demand for practical applications. Considering the sulfur electrochemistry is highly dependent on solid‐liquid‐solid multi‐phase conversion, the electrolyte amount plays a primary role in the practical performances of Li–S cells. Therefore, a lean electrolyte volume with low electrolyte/sulfur ratio is essential for practical Li–S batteries, yet under these conditions it is highly challenging to achieve acceptable electrochemical performances regarding sulfur kinetics, discharge capacity, Coulombic efficiency, and cycling stability especially for high‐sulfur‐loading cathodes. In this Review, the impact of the electrolyte/sulfur ratio on the actual energy density and the economic cost of Li–S batteries is addressed. Challenges and recent progress are presented in terms of the sulfur electrochemical processes: the dissolution–precipitation conversion and the solid–solid multi‐phasic transition. Finally, prospects of future lean‐electrolyte Li–S battery design and engineering are discussed.
Solvent‐Induced Cluster‐to‐Cluster Transformation of Homoleptic Gold(I) Thiolates between Catenane and Ring‐in‐Ring Structures
Authors: Xu Guang‐Tao , Wu Liang‐Liang , Chang Xiao‐Yong , Ang Tim Wai Hung , Wong Wai‐Yeung , Huang Jie‐Sheng , Che Chi‐Ming 
Published: September 2019

AbstractSupramolecular ensembles adopting ring‐in‐ring structures are less developed compared with catenanes featuring interlocked rings. While catenanes with inter‐ring closed‐shell metallophilic interactions, such as d10–d10 AuI–AuI interactions, have been well‐documented, the ring‐in‐ring complexes featuring such metallophilic interactions remain underdeveloped. Herein is described an unprecedented ring‐in‐ring structure of a AuI‐thiolate Au12 cluster formed by recrystallization of a AuI‐thiolate Au10 [2]catenane from alkane solvents such as hexane, with use of a bulky dibutylfluorene‐2‐thiolate ligand. The ring‐in‐ring AuI‐thiolate Au12 cluster features inter‐ring AuI–AuI interactions and underwent cluster core change to form the thermodynamically more stable Au10 [2]catenane structure upon dissolving in, or recrystallization from, other solvents such as CH2Cl2, CHCl3, and CH2Cl2/MeCN. The cluster‐to‐cluster transformation process was monitored by 1H NMR and ESI‐MS measurements. Density functional theory (DFT) calculations were performed to provide insight into the mechanism of the “ring‐in‐ring⇌ [2]catenane” interconversions.
Enzymatic Incorporation of a Coumarin–Guanine Base Pair
Authors: Johnson Aaron , Karimi Ashkan , Luedtke Nathan W. 
Published: September 2019

AbstractPrevious expansions beyond nature's preferred base‐pairing interactions have utilized either nonpolar shape‐fitting interactions or classical hydrogen bonding. Reported here is a hybrid of these systems. By replacing a single N−H with C−H at a Watson–Crick interface, the design space for new drug candidates and fluorescent nucleobase analogues is dramatically expanded, as demonstrated here by the new, highly fluorescent deoxycytidine mimic 3‐glycosyl‐5‐fluoro‐7‐methoxy‐coumarin‐2′‐deoxyribose (dCC). dGTP is selectively incorporated across from a template dCC during enzymatic DNA synthesis. Likewise, dCC is selectively incorporated across from a template guanine when dCC is provided as the triphosphate dCCTP. DNA polymerase I (Klenow fragment) exhibited about a 10‐fold higher affinity for dCCTP than dCTP, allowing selective incorporation of dCC in direct competition experiments. These results demonstrate that a single C−H can replace N−H at a Watson–Crick‐type interface with preservation of functional selectivity and enhanced activity.
Detection of Exhaled Volatile Organic Compounds Improved by Hollow Nanocages of Layered Double Hydroxide on Ag Nanowires
Authors: Qiao Xuezhi , Chen Xiangyu , Huang Chuanhui , Li Ailin , Li Xiao , Lu Zhili , Wang Tie 
Published: September 2019

AbstractTo detect biomarkers from human exhalation, air flow dynamics on the nanoparticle surface were explored by a surface‐enhanced Raman scattering (SERS) sensor. A hollow Co‐Ni layered double hydroxide (LDH) nanocage on Ag nanowires (Ag@LDH) was prepared. Ag nanowires provided amplified Raman signals for trace determination; hollow LDH nanocages served as the gaseous confinement cavity to improve capture and adsorption of gaseous analytes. The Raman intensity and logarithmic analyte concentration exhibit an approximately linear relationship; the detection limit of SERS sensors for aldehyde is 1.9×10−9 v/v (1.9 ppb). Various aldehydes in mixed mimetic gas are distinguished by Raman spectra statistical analysis assisted by multivariate methods, including principal component analysis and hierarchical cluster analysis. The information was recorded in a barcode, which can be used for the design and development of a desktop SERS sensor analysis system for large‐scale lung cancer detection.
Construction of lanthanide complexes supported by 2,3‐dimethoxybenzoic acid and 5,5’‐dimethy‐2,2’‐bipyridine: crystal structures, thermoanalysis, magnetic and fluorescence properties
Authors: Li Ying‐Ying , Ren Ning , He Shu‐Mei , Wang Shu‐Ping , Zhang Jian‐Jun 
Published: September 2019

A series of novel trivalent lanthanide complexes, [Ln(2,3‐DMOBA)3(5,5′‐DM‐2,2′‐bipy)]2·C2H5OH (Ln = Eu(1), Sm(2), Gd(3), Ho(4) Er(5), Pr(6), Nd(7)) (2,3‐DMOBA = 2,3‐dimethoxybenzoate, 5,5′‐DM‐2,2′‐bipy = 5,5′‐dimethy‐2,2′‐bipyridine), have been successfully synthesized and structurally validated by single crystal diffraction. All complexes discussed herein feature a binuclear structure, and contain only one free ethanol molecule, which is interesting in the lanthanide complexes. The coordination number of center Ln3+ ions is nine, showing a distorted monocapped square anti‐prismatic coordination geometry. Through a pair of alternating identical C‐H···O hydrogen bonding interactions between two 2,3‐DMOBA ligands on the same lanthanum binuclear unit with 5,5′‐DM‐2,2′‐bipy ligands on two neighboring units, the binuclear complexes can form one‐ The thermal analysis of these complexes are investigated by TG‐DSC/FTIR, the result show that the decomposition process of complexes are mainly divided into four stages with the formation of the respective oxides. The visible light emission experiment of complex 1 is carried out, and the characteristic luminescence behavior of intense red light is exhibited. What'more, fluorescence lifetimes as well as the fluorescent quantum yield of complex 1 is calculated. And the magnetic properties of complexes 3–5 are also studied.
Effects of biomass diatom frustule on structure and properties of polyurethane elastomer
Authors: Wang Jun , Zhao Dan , Liu Zhiqiang , Chen Hongxiang , Zhou Yu , Zhou Yang , Zhu Bailin 
Published: September 2019

ABSTRACTInorganic particles can dramatically promote the mechanical and thermal properties of polymer materials. However, the study on the effects of inorganic particles on the structure and properties of polymers, as well as the structure–property relationship, is still challengeable. Biomass diatom frustule can be applied to modify polyurethane (PU) elastomer due to its unique network structure, outstanding thermal stability, and wide availability. The PU/modified diatom (MD) frustule composites were prepared by bulk polymerization using PU as substrate and MD frustule as reinforcing phase. The effects of MD frustule on the structure and properties of PU elastomers and the structure–property relationship of composites were investigated. The results reveal that the composites have a certain degree of improvement in the mechanical properties and thermal stability as compared with pristine PU elastomer. It is ascribed to a relatively strong interaction between the MD frustule and PU, so the addition of MD frustule can change the interaction between hard segments and soft segments of PU as well as microphase separation structure. This research provides an experimental basis for the potential application of biomass diatom frustule. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48452.
Lightweight silver@carbon microsphere@graphene (Ag@CMS@GR) composite materials for highly efficiency electromagnetic interference shielding properties
Authors: Zhang Han , Zhang Junhua 
Published: September 2019

ABSTRACTIn this article, lightweight silver@carbon microsphere@graphene (Ag@CMS@GR) composite materials were fabricated. First, carbon microsphere (CMS) was prepared by redox hydrothermal method in the presence of FeCl3 and polyvinyl alcohol. Next, on the surface, silver was deposited to form Ag@CMS particles. And finally, the graphene sheets were added to connect Ag@CMS particles to obtain Ag@CMS@GR composites. Because of the silver nanoparticle may form a conductive pathway, Ag@CMS with relative high content of silver nanoparticles show superior EMI shielding properties. Next, graphene was introduced into Ag@CMS with relative low content of silver particles to form Ag@CMS@GR composites, which is helpful for decreasing the apparent density of composites to around 1.01 g·cm−3. And the composites also show good EMI shielding properties. The highest SE and specific SE values of Ag@CMS@GR reached 39.26 dB and 38.87 dB·cm3·g−1 with 5 wt % graphene content. The EMI shielding mechanism of Ag@CMS@GR composites was discussed. It can be potentially used for lightweight EMI shielding applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48459.