bluuebunny/crossref_metadata_2025_split huggingface dataset:
Water Permeation through Conical Nanopores: Complex Interplay between Surface Roughness and Chemistry
Authors: Nalaparaju Anjaiah , Wang John , Jiang Jianwen 
Published: March 2020

AbstractInspired by biological water channels (e.g., aquaporin with an hourglass shape), there is a growing interest in the use of conical nanopores for water purification; however, the surface roughness of conical nanopores has not been considered in the literature. In this work, a molecular dynamics simulation study is conducted to investigate water permeation through conical nanopores by considering both surface roughness and chemistry. In hydrophilic alumina nanopores, water permeability is found to increase with increasing surface roughness; however, a reverse trend is observed in hydrophobic carbon nanopores. Comprehensive microscopic analysis reveals that surface roughness in the carbon nanopores induces multiple high‐energy barriers and frequent forming/breaking of hydrogen bonding network, which impedes water permeation. In the alumina nanopores, water becomes more bulk‐like with increasing surface roughness, thus enhancing water permeation. The molecular insights from this simulation study provide quantitative understanding of water permeation in hydrophilic and hydrophobic conical nanopores and unravel the complex interplay between surface roughness and chemistry, facilitating the design of new materials for water purification.
Novel All‐Nitrogen Molecular Crystals of Aromatic N10
Authors: Liu Shijie , Zhao Lei , Yao Mingguang , Miao Maosheng , Liu Bingbing 
Published: March 2020

AbstractNitrogen has unique bonding ability to form single, double, and triple bonds, similar to that of carbon. However, a molecular crystal formed by an aromatic polynitrogen similar to a carbon system has not been found yet. Herein, a new form of stable all‐nitrogen molecular crystals consisting of only bispentazole N10 molecules with exceedingly high energy density is predicted. The crystal structures and the conformation of N10 molecules are strongly correlated, both depending on the applied external pressure. These molecular crystals can be recovered upon the release of the pressure. The first‐principles molecular dynamics simulations reveal that these all‐nitrogen materials decompose at temperatures much higher than room temperature. The decompositions always start from breaking off N2 molecules from the nitrogen ring and can release a large amount of energy. These new polynitrogens are aromatic and are more stable than all the other polynitrogen crystals reported previously, providing a new green strategy to get all‐nitrogen, nonpolluting high energy density materials without introducing any metal or other guest stabilizer.
Medical Gas Plasma Jet Technology Targets Murine Melanoma in an Immunogenic Fashion
Authors: Bekeschus Sander , Clemen Ramona , Nießner Felix , Sagwal Sanjeev Kumar , Freund Eric , Schmidt Anke 
Published: March 2020

AbstractMedical technologies from physics are imperative in the diagnosis and therapy of many types of diseases. In 2013, a novel cold physical plasma treatment concept was accredited for clinical therapy. This gas plasma jet technology generates large amounts of different reactive oxygen and nitrogen species (ROS). Using a melanoma model, gas plasma technology is tested as a novel anticancer agent. Plasma technology derived ROS diminish tumor growth in vitro and in vivo. Varying the feed gas mixture modifies the composition of ROS. Conditions rich in atomic oxygen correlate with killing activity and elevate intratumoral immune‐infiltrates of CD8+ cytotoxic T‐cells and dendritic cells. T‐cells from secondary lymphoid organs of these mice stimulated with B16 melanoma cells ex vivo show higher activation levels as well. This correlates with immunogenic cancer cell death and higher calreticulin and heat‐shock protein 90 expressions induced by gas plasma treatment in melanoma cells. To test the immunogenicity of gas plasma treated melanoma cells, 50% of mice vaccinated with these cells are protected from tumor growth compared to 1/6 and 5/6 mice negative control (mitomycin C) and positive control (mitoxantrone), respectively. Gas plasma jet technology is concluded to provide immunoprotection against malignant melanoma both in vitro and in vivo.
External‐Field‐Free Spin Hall Switching of Perpendicular Magnetic Nanopillar with a Dipole‐Coupled Composite Structure
Authors: Zhao Zhengyang , Smith Angeline K. , Jamali Mahdi , Wang Jian‐Ping 
Published: March 2020

AbstractSpin Hall effect (SHE)‐induced reversal of perpendicular magnetization has attracted significant interest, due to its potential for low‐power memory and logic devices. However, the switching requires an assisted in‐plane magnetic field, which hampers its practical applications. Here, a new approach for external‐field‐free spin Hall switching of a perpendicular nanomagnet is introduced. This approach utilizes a local dipolar field arising from an in‐plane biasing layer to assist the switching. Robust switching of a 285 × 95 nm2 perpendicular CoFeB nanomagnet is demonstrated in the absence of any external magnetic field. Micromagnetic simulation is performed to illustrate the magnetic dynamics of the switching process. Large in‐plane compensation field of 135 Oe is obtained in the composite nanodevices, reflecting a strong symmetry‐breaking behavior. Compared with other proposed methods for external‐field‐free spin Hall switching, the dipole‐coupled composite structure is compatible with a wide range of spin Hall systems and perpendicular magnetic tunnel junctions, paving a way towards practical spin–orbit torque‐based memory and logic applications.
Global Health Training in U.S. Emergency Medicine Residency Programs
Authors: Rybarczyk Megan M. , Muck Andrew , Kolkowitz Ilan , Tupesis Janis P. , Jacquet Gabrielle A. 
Published: March 2020

AbstractObjectivesFormal education in global health (GH) and short‐term experiences in GH (STEGH) are offered by many emergency medicine (EM) residency programs in the United States. In an increasingly connected world, training in GH and STEGH can provide essential knowledge and practical skills to trainees, particularly at the graduate medical education level. The current core programmatic components and the essential competencies and curricula that support ethical and effective STEGH, however, still vary widely. The authors conducted a survey of the 228 EM residency programs in the United States to describe the current state of GH training and STEGH.MethodsAn online survey was developed in REDCap by a team of GH faculty. In July 2018, programs were invited to participate via individual invitation of program directors from a directory. The programs received two reminders to participate until January 2019.ResultsOf the 84 programs that responded, 75% offer STEGH and 39% have longitudinal GH curricula. Within these programs, only 55% have dedicated GH faculty and only 70% have dedicated sites. Both faculty and residents encounter funding and insurance barriers; most notably, only 20% of programs that offer STEGH provide evacuation insurance for their residents. Most residents (95%) engage in clinical work along with teaching and other activities, but 24% of programs do not allow these activities to fulfill any residency requirements. Finally, only 80 and 85% of programs offer preparatory and debriefing activities for residents, respectively.ConclusionsWhile the results of this survey show progress relative to prior surveys, there are still barriers to implementing GH curricula and supporting safe, ethical, and effective STEGH, particularly in the form of continued financial and logistic support for faculty and for residents, in U.S. EM training programs.
Hydroseeding with mesotrione in tankmix for establishment of perennial ryegrass
Authors: Pease B.W. , Stier J.C. 
Published: March 2020

AbstractMesotrione (2‐[4‐(methylsulfonyl)‐2‐nitrobenzoyl]‐1,3‐cyclohexanedione) is a proven effective weed control product in agricultural and turf settings but its use within a hydroseeding mixture has not been investigated. Two experiments were conducted to evaluate the effects of (1) mesotrione rate and (2) duration of herbicide exposure on turf establishment and weed populations through hydroseeding establishment methodology. The experimental design of both studies was a randomized complete block, incorporating a split‐plot in the second study, with four replications and repeated in two years. Perennial ryegrass (Lolium perenne L., variety not stated) was hydroseeded on a silt loam soil (pH 7.0) in summer at 39 g m−2 in a slurry delivering 6.1 L m−2. Treatments in the first study were mesotrione rates of 0.000, 0.088, 0.175, and 0.263 kg a.i. ha−1. Treatments in the second study were duration of mixture in tank before applying of 0, 2, and 4 h, with and without mesotrione at 0.175 kg a.i. ha−1. Turfgrass percent cover, turfgrass injury, and weed populations were assessed for both studies. The addition of mesotrione at any rate to the hydroseeding slurry did not reduce desired turf populations; in many cases, the amount of desired turf cover increased. Weed populations were significantly reduced by all mesotrione rates; the effect was most evident at the two highest rates. No treatments caused turf injury. Length of time in the hydroseeding slurry did not reduce herbicide efficacy or desired turf populations, or cause turf injury.
Gigantic chloroplasts, including bizonoplasts, are common in shade‐adapted species of the ancient vascular plant family Selaginellaceae
Authors: Liu Jian‐Wei , Li Shau‐Fu , Wu Chin‐Ting , Valdespino Iván A. , Ho Jia‐Fang , Wu Yeh‐Hua , Chang Ho‐Ming , Guu Te‐Yu , Kao Mei‐Fang , Chesson Clive , Das Sauren , Oppenheimer Hank , Bakutis Ane , Saenger Peter , Salazar Allen Noris , Yong Jean W. H. , Adjie Bayu , Kiew Ruth , Nadkarni Nalini , Huang Chun‐Lin , Chesson Peter , Sheue Chiou‐Rong 
Published: March 2020

PremiseUnique among vascular plants, some species of Selaginella have single giant chloroplasts in their epidermal or upper mesophyll cells (monoplastidy, M), varying in structure between species. Structural variants include several forms of bizonoplast with unique dimorphic ultrastructure. Better understanding of these structural variants, their prevalence, environmental correlates and phylogenetic association, has the potential to shed new light on chloroplast biology unavailable from any other plant group.MethodsThe chloroplast ultrastructure of 76 Selaginella species was studied with various microscopic techniques. Environmental data for selected species and subgeneric relationships were compared against chloroplast traits.ResultsWe delineated five chloroplast categories: ME (monoplastidy in a dorsal epidermal cell), MM (monoplastidy in a mesophyll cell), OL (oligoplastidy), Mu (multiplastidy, present in the most basal species), and RC (reduced or vestigial chloroplasts). Of 44 ME species, 11 have bizonoplasts, cup‐shaped (concave upper zone) or bilobed (basal hinge, a new discovery), with upper zones of parallel thylakoid membranes varying subtly between species. Monoplastidy, found in 49 species, is strongly shade associated. Bizonoplasts are only known in deep‐shade species (<2.1% full sunlight) of subgenus Stachygynandrum but in both the Old and New Worlds.ConclusionsMultiplastidic chloroplasts are most likely basal, implying that monoplastidy and bizonoplasts are derived traits, with monoplastidy evolving at least twice, potentially as an adaptation to low light. Although there is insufficient information to understand the adaptive significance of the numerous structural variants, they are unmatched in the vascular plants, suggesting unusual evolutionary flexibility in this ancient plant genus.
An Endergonic Synthesis of Single Sondheimer–Wong Diyne by Local Probe Chemistry
Authors: Kawai Shigeki , Sang Hongqian , Kantorovich Lev , Takahashi Keisuke , Nozaki Kyoko , Ito Shingo 
Published: March 2020

AbstractRecent advances in scanning probe microscopy on surface enable not only direct observation of molecular structures but also local probe reactions, in which unstable short‐lived products have been synthesized and analyzed. Now, an endergonic reaction to synthesize a single Sondheimer–Wong diyne from 6,13‐dibromopentaleno[1,2‐b:4,5‐b′]dinaphthalene by local probe chemistry on a ultra‐thin film of NaCl formed on a Cu(111) surface at 4.3 K is presented. The structures of the precursor, two intermediates, and the final product were directly identified by the differential conductance imaging with a CO functionalized tip. DFT calculations revealed that the multiple‐step reaction, being endergonic overall, is facilitated by temporal charging and discharging of the molecule placed in the nanometric junction between the Cu tip and the Cu substrate underneath the ultra‐thin NaCl film. This local probe reaction expands possibilities to synthesize nanocarbon materials in a bottom‐up manner.
Electrophotocatalytic Decarboxylative C−H Functionalization of Heteroarenes
Authors: Lai Xiao‐Li , Shu Xiao‐Min , Song Jinshuai , Xu Hai‐Chao 
Published: March 2020

AbstractDecarboxylative C−H functionalization reactions are highly attractive methods for forging carbon–carbon bonds considering their inherent step‐ and atom‐economical features and the pervasiveness of carboxylic acids and C−H bonds. An ideal approach to achieve these dehydrogenative transformations is through hydrogen evolution without using any chemical oxidants. However, effective couplings by decarboxylative carbon–carbon bond formation with proton reduction remain an unsolved challenge. Herein, we report an electrophotocatalytic approach that merges organic electrochemistry with photocatalysis to achieve the efficient direct decarboxylative C−H alkylation and carbamoylation of heteroaromatic compounds through hydrogen evolution. This electrophotocatalytic method, which combines the high efficiency and selectivity of photocatalysis in promoting decarboxylation with the superiority of electrochemistry in effecting proton reduction, enables the efficient coupling of a wide range of heteroaromatic bases with a variety of carboxylic acids and oxamic acids. Advantageously, this method is scalable to decagram amounts, and applicable to the late‐stage functionalization of drug molecules.
“Anti‐Electrostatic” Halogen Bonding
Authors: Holthoff Jana M. , Engelage Elric , Weiss Robert , Huber Stefan M. 
Published: March 2020

AbstractHalogen bonding is often described as being driven predominantly by electrostatics, and thus adducts between anionic halogen bond (XB) donors (halogen‐based Lewis acids) and anions seem counterintuitive. Such “anti‐electrostatic” XBs have been predicted theoretically but for organic XB donors, there are currently no experimental examples except for a few cases of self‐association. Reported herein is the synthesis of two negatively charged organoiodine derivatives that form anti‐electrostatic XBs with anions. Even though the electrostatic potential is universally negative across the surface of both compounds, DFT calculations indicate kinetic stabilization of their halide complexes in the gas phase and particularly in solution. Experimentally, self‐association of the anionic XB donors was observed in solid‐state structures, resulting in dimers, trimers, and infinite chains. In addition, co‐crystals with halides were obtained, representing the first cases of halogen bonding between an organic anionic XB donor and a different anion. The bond lengths of all observed interactions are 14–21 % shorter than the sum of the van der Waals radii.
Organoboron‐Functionalization Enables the Hierarchical Assembly of Giant Polyoxometalate Nanocapsules
Authors: Li Shujun , Zhou Yanfang , Ma Nana , Zhang Jie , Zheng Zhiping , Streb Carsten , Chen Xuenian 
Published: March 2020

AbstractThe aggregation of molecular metal oxides into larger superstructures can bridge the gap between molecular compounds and solid‐state materials. Here, we report that functionalization of polyoxotungstates with organo‐boron substituents leads to giant polyoxometalate‐based nanocapsules with dimensions of up to 4 nm. A “lock and key” mechanism enables the site‐specific anchoring of aromatic organo‐boronic acids to metal‐functionalized Dawson anions [M3P2W15O62]9− (M=TaV or NbV), resulting in unique nanocapsules containing up to twelve POM units. Experimental and theoretical studies provide initial insights into the role of the organo‐boron moieties and the metal‐functionalized POMs for the assembly of the giant aggregates. The study therefore lays the foundations for the design of organo‐POM‐based functional nanostructures.
Functional analysis of novel sulfotransferases in the silkworm Bombyx mori
Authors: Bairam Ahsan F. , Kermasha Zainab W. , Liu Ming‐Cheh , Kurogi Katsuhisa , Yamamoto Kohji 
Published: March 2020

AbstractSulfoconjugation plays a vital role in the detoxification of xenobiotics and in the metabolism of endogenous compounds. In this study, we aimed to identify new members of the sulfotransferase (SULT) superfamily in the silkworm Bombyx mori. Based on amino acid sequence and phylogenetic analyses, two new enzymes, swSULT ST1 and swSULT ST2, were identified that appear to belong to a distinct group of SULTs including several other insect SULTs. We expressed, purified, and characterized recombinant SULTs. While swSULT ST1 sulfated xanthurenic acid and pentachlorophenol, swSULT ST2 exclusively utilized xanthurenic acid as a substrate. Based on these results, and those concerning the tissue distribution and substrate specificity toward pentachlorophenol analyses, we hypothesize that swSULT ST1 plays a role in the detoxification of xenobiotics, including insecticides, in the silkworm midgut and in the induction of gametogenesis in silkworm ovary and testis. Collectively, the data obtained herein contribute to a better understanding of SULT enzymatic functions in insects.
Regulation of 2D Graphene Materials for Electrocatalysis
Authors: Zhang Xinqun , Gao Jian , Xiao Yukun , Wang Jiaqi , Sun Guoqiang , Zhao Yang , Qu Liangti 
Published: March 2020

AbstractBenefiting from unique excellent physical and chemical characteristics, graphene has attracted widespread attention in the application of electrocatalysis. As a promising candidate, graphene is usually regulated with surface defects, heteroatoms, metal atoms and other active materials through covalent or non‐covalent bonds to substitute for noble metal catalysts, which has not been targeted in a report yet. In this review, we summarize the recent advances of approaches for engineering graphene‐based electrocatalysts and emphasize the corresponding electrocatalytic active sites in various electrocatalysis circumstances, such as electrocatalytic hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), etc. The opportunities and challenges in the future development of graphene‐based catalysts are also discussed.
Ghost Introgression: Spooky Gene Flow in the Distant Past
Authors: Ottenburghs Jente 
Published: March 2020

AbstractEvolution is a continuous trial and error process in which most lineages go extinct without leaving fossil remains. Many of these lineages would be closely related and occasionally hybridized with lineages that gave rise to extant species. Hence, it is likely that one can find genetic signatures of these ancient introgression events in present‐day genomes, so‐called ghost introgression. The increasing availability of high‐quality genome assemblies for non‐model organisms and the development of more sophisticated methods for detecting introgression will undoubtedly reveal more cases of ghost introgression, indicating that the Tree of Life is even more reticulated than assumed. The presence of ghost introgression has important consequences for the study of numerous evolutionary processes, including adaptation, speciation, and macroevolutionary patterns. In addition, detailed studies of introgressed regions could provide insights into the morphology of the extinct lineage, providing an unexpected link between genomics and the fossil record. Hence, new methods that take into account ghost introgression will need to be developed.
Research and application of situated teaching design for NC machining course based on virtual simulation technology
Authors: Li Meng , Li Yongxiang , Guo Haixia 
Published: March 2020

AbstractAs virtual simulation technology can display three‐dimensional materials as well as their dynamic cutting process and the learners’ motivation is enhanced in the situated learning environment, a virtual‐situated learning system for numerical control (NC) machining course is proposed to explore the learning effectiveness of learners when combining virtual simulation technology and the situation learning theory. This study aims to use the concept of embedding NC machining simulation system and the situated learning into a real situation to improve the learners’ situated thinking ability and innovative literacy. The features of the system include (a) the learning activities and contents that are planned and designed using the key factors of situated learning based on the specific teaching contents and objectives, (b) combining virtual objects with a real environment using virtual simulation technology to provide a project‐based learning situation for learners, and (c) probing into the specific methods of implementing situated teaching design in NC machining course. To assess the acceptance of the proposed system, an independent sample t‐test was then applied to evaluate the learning achievement of learners. The results show that the research scale is highly reliable and that all assumptions made are valid. In addition, the effect of the situated teaching was investigated through questionnaire survey. The experimental results suggest that the virtual‐situated teaching design has significant positive impact on improving the students' learning efficiency and performance skills and indicates that the participants were attracted to and willing to use the system, which directly enhances their incentive to actively learn and promote learning achievement.
Trichodermaloids A–C, Cadinane Sesquiterpenes from a Marine Sponge Symbiotic Trichoderma sp. SM16 Fungus
Authors: Cui Jie , Shang Ru‐Yi , Sun Mei , Li Yi‐Xuan , Liu Hong‐Yan , Lin Hou‐Wen , Jiao Wei‐Hua 
Published: March 2020

AbstractThree new cadinane sesquiterpenes, trichodermaloids A (1), B (2), and C (5) were isolated from a symbiotic fungus Trichoderma sp. SM16 derived from the marine sponge Dysidea sp., together with three known ones, aspergilloid G (3), rhinomilisin E (4), and rhinomilisin G (6). The complete structures of three new compounds were determined by HR‐MS and NMR spectroscopic analyses coupled with ECD calculations. The absolute configurations of two known compounds (4 and 6) were determined for the first time. The six isolates were inactive as antibacterial agents. However, trichodermaloids A and B have shown cytotoxicity on human NCIH‐460 lung, NCIC‐H929 myeloma, and SW620 colorectal cancer cell lines with IC50 values at the range of 6.8–12.7 μm.
Enzyme Mimic Nanomaterials and Their Biomedical Applications
Authors: Shang Yingxu , Liu Fengsong , Wang Yuanning , Li Na , Ding Baoquan 
Published: March 2020

AbstractNanomaterials with enzyme‐mimicking behavior (nanozymes) have attracted a lot of research interest recently. In comparison to natural enzymes, nanozymes hold many advantages, such as good stability, ease of production and surface functionalization. As the catalytic mechanism of nanozymes is gradually revealed, the application fields of nanozymes are also broadly explored. Beyond traditional colorimetric detection assays, nanozymes have been found to hold great potential in a variety of biomedical fields, such as tumor theranostics, antibacterial, antioxidation and bioorthogonal reactions. In this review, we summarize nanozymes consisting of different nanomaterials. In addition, we focus on the catalytic performance of nanozymes in biomedical applications. The prospects and challenges in the practical use of nanozymes are discussed at the end of this Minireview.