bluuebunny/crossref_metadata_2025_split huggingface dataset:
kuenm: an R package for detailed development of ecological niche models using Maxent
Authors: Cobos Marlon E. , Peterson A. Townsend , Barve Narayani , Osorio-Olvera Luis 
Published: February 2019

BackgroundEcological niche modeling is a set of analytical tools with applications in diverse disciplines, yet creating these models rigorously is now a challenging task. The calibration phase of these models is critical, but despite recent attempts at providing tools for performing this step, adequate detail is still missing. Here, we present the kuenm R package, a new set of tools for performing detailed development of ecological niche models using the platform Maxent in a reproducible way.ResultsThis package takes advantage of the versatility of R and Maxent to enable detailed model calibration and selection, final model creation and evaluation, and extrapolation risk analysis. Best parameters for modeling are selected considering (1) statistical significance, (2) predictive power, and (3) model complexity. For final models, we enable multiple parameter sets and model transfers, making processing simpler. Users can also evaluate extrapolation risk in model transfers via mobility-oriented parity (MOP) metric.DiscussionUse of this package allows robust processes of model calibration, facilitating creation of final models based on model significance, performance, and simplicity. Model transfers to multiple scenarios, also facilitated in this package, significantly reduce time invested in performing these tasks. Finally, efficient assessments of strict-extrapolation risks in model transfers via the MOP and MESS metrics help to prevent overinterpretation in model outcomes.
DESIGN OPTIMIZATION OF EAST LONDON FORESHORE PROTECTION DURING CONSTRUCTION
Authors: Letsie Masupha , Setaka Malefetsane 
Published: February 2019

Transnet Group Capital (TGC) was appointed by
Transnet National Ports Authority (TNPA) to manage
construction of a revetment at East London Foreshore
in East London, South Africa. The revetment
construction was initiated to halt a 40 m regression of
the reclaimed land between the grain elevator and the
sea. This area accommodates the access road to the
terminus yard as well as the rail lines that serve the grain
elevator.
Phase‐Changeable Nanoemulsions for Oral Delivery of a Therapeutic Peptide: Toward Targeting the Pancreas for Antidiabetic Treatments Using Lymphatic Transport
Authors: Lin Po‐Yen , Chen Kuan‐Hung , Miao Yang‐Bao , Chen Hsin‐Lung , Lin Kun‐Ju , Chen Chiung‐Tong , Yeh Chun‐Nan , Chang Yen , Sung Hsing‐Wen 
Published: February 2019

AbstractThe oral absorption of a therapeutic peptide (such as exenatide; EXT) that can improve glycemic control in the treatment of type 2 diabetes is limited by multiple barriers of the intestinal epithelium. This work presents an oil‐structured nanoemulsion system that consists of a phase‐changeable fatty acid that allows EXT (EXT@PC/NEMs) to be delivered orally and absorbed efficiently in the small intestine. To construct an appropriate vehicle to encapsulate EXT, an oil‐in‐water single emulsion is generated at 37 °C, which is well above the melting point of the fatty acid but below the denaturation temperature of the peptide drug. The as‐prepared EXT@PC/NEMs are physically stable when stored at 4 °C, as they form a solid core, which prevents drug leakage. Upon their oral delivery at body temperature, the deformable liquid EXT@PC/NEMs may undergo effective cellular uptake, enhancing their permeability across the intestinal epithelium. The orally administered PC/NEMs significantly improve the bioavailability of EXT via intestinal lymphatic transport, ultimately accumulating in the pancreas, suggesting the possibility of orally delivering labile peptide drugs. The delivered EXT may act on pancreatic β‐ and α‐cells to stimulate insulin release and suppress glucagon secretion, respectively, reducing the blood glucose level, eventually having antidiabetic effects.
Sunlight‐Driven Wearable and Robust Antibacterial Coatings with Water‐Soluble Cellulose‐Based Photosensitizers
Authors: Jia Ruonan , Tian Weiguo , Bai Haotian , Zhang Jinming , Wang Shu , Zhang Jun 
Published: February 2019

AbstractHerein, a simple, effective, and general strategy is demonstrated to obtain a water‐soluble and nontoxic cellulose‐based photosensitizer (CPS) with enhanced photodynamic antibacterial activity through introducing protoporphyrin IX (PpIX) and quaternary ammonium salt (QAS) groups onto the cellulose backbone. The synergistic effect of the anchoring and diluting effect of the cellulose backbone and the electrostatic repulsion between QAS groups effectively inhibit the π–π stacking of PpIX groups, thus the as‐prepared CPS exhibits markedly enhanced reactive oxygen species (ROS) yield. Meanwhile, the positively charged QAS groups endow the CPS with water‐solubility and a strong attractive force to bacteria. As a result, the CPS can rapidly and efficiently kill drug‐resistant bacteria strains, including E. coli and S. aureus, with a low light dose (2.4 J cm−2) and low concentration of PpIX groups (0.35 × 10−6m). Benefiting from the excellent processability and formability, the CPS is readily applied as a sunlight‐driven wearable and robust antibacterial coating by a spray coating and later crosslinking procedure.
Antibiotic‐Free Cationic Dendritic Hydrogels as Surgical‐Site‐Infection‐Inhibiting Coatings
Authors: Andrén Oliver C. J. , Ingverud Tobias , Hult Daniel , Håkansson Joakim , Bogestål Yalda , Caous Josefin S. , Blom Kristina , Zhang Yuning , Andersson Therese , Pedersen Emma , Björn Camilla , Löwenhielm Peter , Malkoch Michael 
Published: February 2019

AbstractA non‐toxic hydrolytically fast‐degradable antibacterial hydrogel is herein presented to preemptively treat surgical site infections during the first crucial 24 h period without relying on conventional antibiotics. The approach capitalizes on a two‐component system that form antibacterial hydrogels within 1 min and consist of i) an amine functional linear‐dendritic hybrid based on linear poly(ethylene glycol) and dendritic 2,2‐bis(hydroxymethyl)propionic acid, and ii) a di‐N‐hydroxysuccinimide functional poly(ethylene glycol) cross‐linker. Broad spectrum antibacterial effect is achieved by multivalent representation of catatonically charged β‐alanine on the dendritic periphery of the linear dendritic component. The hydrogels can be applied readily in an in vivo setting using a two‐component syringe delivery system and the mechanical properties can accurately be tuned in the range equivalent to fat tissue and cartilage (G′ = 0.5–8 kPa). The antibacterial effect is demonstrated both in vitro toward a range of relevant bacterial strains and in an in vivo mouse model of surgical site infection.
Sulfur‐Catalyzed Oxidative Coupling of Dibenzyl Disulfides with Amines: Access to Thioamides and Aza Heterocycles
Authors: Nguyen Thanh Binh , Nguyen Le Phuong Anh , Nguyen Thi Thu Tram 
Published: February 2019

AbstractIn the presence of catalytic amounts of elemental sulfur, dibenzyl disulfide/DMSO was found to be an excellent thiobenzoylating agent of amines to provide a wide range of thioamides. The reaction becomes autocatalytic when anilines substituted by an o‐cyclizable group were used as nucleophile, leading to the corresponding 2‐aryl aza heterocycles.magnified image
Fundamental Understanding of Photocurrent Hysteresis in Perovskite Solar Cells
Authors: Liu Pengyun , Wang Wei , Liu Shaomin , Yang Huagui , Shao Zongping 
Published: February 2019

AbstractOrganic–inorganic hybrid perovskite solar cells (PSCs) have become a promising candidate in the photovoltaic field due to their high power conversion efficiency and low material cost. However, the development of PSCs is limited by their poor stability under practical conditions in the presence of oxygen, moisture, sunlight, heat, and the current–voltage (I–V) hysteresis. In particular, the hysteretic I–V issue casts doubt on the validity of the photovoltaic performance results that are achieved, making it difficult to evaluate the authentic performance of PSCs. This review article focuses on understanding the I–V hysteresis behavior in PSCs and on exploring the possible reasons leading to this hysteresis phenomenon. The various strategies attempted to suppress the I–V hysteresis in PSCs are summarized, and a brief future recommendation is provided.
Impact of shift duration on alertness among air‐medical emergency care clinician shift workers
Authors: Patterson P. Daniel , Weaver Matthew D. , Markosyan Mark A. , Moore Charity G. , Guyette Frank X. , Doman Jack M. , Sequeira Denisse J. , Werman Howard A. , Swanson Doug , Hostler David , Lynch Joshua , Templin Megan A. , Rozario Nigel L. , Russo Lindsey , Hines Linda , Swecker Karen , Runyon Michael S. , Buysse Daniel J. 
Published: February 2019

BackgroundGreater than half of Emergency Medical Services (EMS) shift workers report fatigue at work and most work long duration shifts. We sought to compare the alertness level of EMS shift workers by shift duration.MethodsWe used a multi‐site, 14‐day prospective observational cohort study design of EMS clinician shift workers at four air‐medical EMS organizations. The primary outcome was behavioral alertness as measured by psychomotor vigilance tests (PVT) at the start and end of shifts. We stratified shifts by duration (< 24 h and 24 h), night versus day, and examined the impact of intra‐shift napping on PVT performance.ResultsOne hundred and twelve individuals participated. The distribution of shifts <24 h and 24 h with complete data were 54% and 46%, respectively. We detected no differences in PVT performance measures stratified by shift duration (P > 0.05). Performance for selected PVT measures (lapses and false starts) was worse on night shifts compared to day shifts (P < 0.05). Performance also worsened with decreasing time between waking from a nap and the end of shift PVT assessment.ConclusionsDeficits in performance in the air‐medical setting may be greatest during night shifts and proximal to waking from an intra‐shift nap. Future research should examine alertness and performance throughout air‐medical shifts, as well as investigate the timing and duration of intra‐shift naps on outcomes.
Excitonic Emission in van der Waals Nanotubes of Transition Metal Dichalcogenides
Authors: Shubina Tatiana V. , Remškar Maja , Davydov Valery Yu. , Belyaev Kirill G. , Toropov Alexey A. , Gil Bernard 
Published: February 2019

AbstractNanotubes (NTs) of transition metal dichalcogenides (TMDs), were first synthesized more than a quarter of a century ago; nevertheless, many of their optical properties have so far remained basically unknown. Herein, the state of the art in the knowledge of the optical properties of TMD NTs is presented. First, general properties of multilayered crystals are evaluated, and available data on related NTs are analyzed. Then, the technology for the formation and the structural characteristics of NTs are represented, focusing on the structures synthesized by chemical transport reaction. The core of this work is the presentation of the ability of synthesized TMD NTs to emit bright photoluminescence (PL), which has been discovered recently. By means of micro‐PL spectroscopy of individual tubes, we show that excitonic transitions relevant to both direct and indirect band gaps contribute to the emission spectra of the NTs despite having the dozens of monolayers in their walls. The performance of the tubes as efficient optical resonators is highlighted, where confined optical modes strongly affect the emission. Finally, a brief conclusion is presented, along with an outlook of the future studies of this novel radiative member of the NTs family, which have unique potential for different nanophotonics applications.
Light‐Driven Self‐Healing of Nanoparticle‐Based Metamolecules
Authors: Nan Fan , Yan Zijie 
Published: February 2019

AbstractMetamolecules and crystals consisting of nanoscale building blocks offer rich models to study colloidal chemistry, materials science, and photonics. Herein we demonstrate the self‐assembly of colloidal Ag nanoparticles into quasi‐one‐dimensional metamolecules with an intriguing self‐healing ability in a linearly polarized optical field. By investigating the spatial stability of the metamolecules, we found that the origin of self‐healing is the inhomogeneous interparticle electrodynamic interactions enhanced by the formation of unusual nanoparticle dimers, which minimize the free energy of the whole structure. The equilibrium configuration and self‐healing behavior can be further tuned by modifying the electrical double layers surrounding the nanoparticles. Our results reveal a unique route to build self‐healing colloidal structures assembled from simple metal nanoparticles. This approach could potentially lead to reconfigurable plasmonic devices for photonic and sensing applications.
Interfacing Formate Dehydrogenase with Metal Oxides for the Reversible Electrocatalysis and Solar‐Driven Reduction of Carbon Dioxide
Authors: Miller Melanie , Robinson William E. , Oliveira Ana Rita , Heidary Nina , Kornienko Nikolay , Warnan Julien , Pereira Inês A. C. , Reisner Erwin 
Published: February 2019

AbstractThe integration of enzymes with synthetic materials allows efficient electrocatalysis and production of solar fuels. Here, we couple formate dehydrogenase (FDH) from Desulfovibrio vulgaris Hildenborough (DvH) to metal oxides for catalytic CO2 reduction and report an in‐depth study of the resulting enzyme–material interface. Protein film voltammetry (PFV) demonstrates the stable binding of FDH on metal‐oxide electrodes and reveals the reversible and selective reduction of CO2 to formate. Quartz crystal microbalance (QCM) and attenuated total reflection infrared (ATR‐IR) spectroscopy confirm a high binding affinity for FDH to the TiO2 surface. Adsorption of FDH on dye‐sensitized TiO2 allows for visible‐light‐driven CO2 reduction to formate in the absence of a soluble redox mediator with a turnover frequency (TOF) of 11±1 s−1. The strong coupling of the enzyme to the semiconductor gives rise to a new benchmark in the selective photoreduction of aqueous CO2 to formate.
Stacking‐Layer‐Number Dependence of Water Adsorption in 3D Ordered Close‐Packed g‐C3N4 Nanosphere Arrays for Photocatalytic Hydrogen Evolution
Authors: Lin Bo , Yang Guidong , Wang Lianzhou 
Published: February 2019

AbstractWater adsorption capacity is a key factor to influence the photocatalytic H2 evolution activity of polymeric g‐C3N4 . Herein, we report the synthesis of 3D ordered close‐packed g‐C3N4 nanosphere arrays (CNAs) that significantly enhance the water adsorption capacity. Through precisely controlling the average stacking‐layer number (ASLN) of the nanospheres in CNAs, we reveal an interesting stacking‐layer‐number dependence of water adsorption in the newly designed CNAs for accelerating the H2 evolution reaction, which can be attributed to the differences in adsorption surface areas and adsorption sites endowed by the point‐defect cavities in sample CNAs.
From Octahedral to Icosahedral Metal–Organic Polyhedra Assembled from Two Types of Polyoxovanadate Clusters
Authors: Xu Na , Gan Hongmei , Qin Chao , Wang Xinlong , Su Zhongmin 
Published: February 2019

AbstractDesign and synthesis of metal–organic polyhedra (MOPs) with targeted geometries from predetermined secondary building units (SBUs) is a long‐standing challenge in chemistry and material science. Theoretical prediction shows that there are 6 possible polyhedra from the 3‐coordinated, 4‐coordinated octahedron ((3,4)‐c octahedron) to (3,5)‐c icosahedron with minimal transitivity (simplest possible). Except for one missing polyhedron (mtr) due to the unfavorable angles, we report five MOPs based on these structures, including an octahedral (3,4)‐c VMOP‐21 (rdo), an icosahedral (3,5)‐c VMOP‐25 (trc), and three intermediate derived trinodal (3,4,5)‐c VMOP‐22–24 (ghm, hmg, xum). Remarkably, all these MOPs obey the minimal transitivity principle and are consistent with geometrical predictions.
Nickel‐Catalyzed Thiolation of Aryl Halides and Heteroaryl Halides through Electrochemistry
Authors: Liu Dong , Ma Hong‐Xing , Fang Ping , Mei Tian‐Sheng 
Published: February 2019

AbstractTransition‐metal‐catalyzed coupling reactions are useful tools for synthesizing aryl sulfur compounds. However, conventional transition‐metal‐catalyzed thiolation of aryl bromides and chlorides typically requires the use of strong base under elevated reaction temperature. Herein, we report the first examples of nickel‐catalyzed electrochemical thiolation of aryl bromides and chlorides in the absence of an external base at room temperature using undivided electrochemical cells.
Some new Ag(I), VO(II) and Pd(II) chelates incorporating tridentate imine ligand: Design, synthesis, structure elucidation, density functional theory calculations for DNA interaction, antimicrobial and anticancer activities and molecular docking studies
Authors: Abdel‐Rahman Laila H. , Abu‐Dief Ahmed M. , Shehata Mohamed R. , Atlam Faten M. , Abdel‐Mawgoud Azza A. Hassan 
Published: February 2019

Some new complexes derived from VO(II), Ag(I) and Pd(II) metal ions and HNA imine ligand (L), i.e. (2‐((6‐allylidene‐2‐hydroxycyclohexa‐1,3‐dienylmethylene)amino)benzoic acid), have been prepared and their structures elucidated via molar conductance measurements, elemental analyses, infrared, NMR and electronic spectra and magnetic susceptibility estimations. Moreover, stability constants of the synthesized complexes were evaluated utilizing a spectrophotometric technique. On the basis of molar conductance and elemental analyses, the metal imine chelates have structure [M(L)], where M = Pd(II), VO(II) and Ag(I). The results indicate that the prepared HNA imine ligand acts as a tridentate moiety via nitrogen atom of azomethine group and two oxygen atoms of phenolic and carboxylic groups. All the complexes are found to be monomeric with 1:1 stoichiometry with square planar geometry for Pd(II), tetrahedral geometry for Ag(I) and distorted square pyramidal for VO(II). Theoretical density functional theory calculations were applied to verify the molecular geometry of the chelators and their metal chelates. The geometry optimization results are in agreement with experimental observations. The antimicrobial properties of the prepared HNA imine ligand and its metal chelates were evaluated against numerous plant pathogenic fungi and bacteria. The results of these studies indicate that the metal complexes exhibit a stronger antibacterial and antifungal effect compared to the imine ligand. In addition, the interaction of the metal imine chelates with calf thymus DNA was observed by way of viscosity, gel electrophoreses and spectral studies. Absorption titration studies reveal that each of the complexes is an avid binder to calf thymus DNA. Also, there are appreciable changes in the relative viscosity of DNA, which are consistent with enhanced hydrophobic interaction of the aromatic rings and intercalation mode of binding. Additionally, the cytotoxic activity of the investigated compounds against various cancer cell lines shows promising results which makes them prospective compounds for antibiotic and anticancer medicament studies. Furthermore, docking studies of the prepared compounds were conducted for confirming the biological results.
Surface texture and barrier performance of poly(lactic acid)–cellulose nanocrystal extruded‐cast films
Authors: Liu Yuzhu , Matuana Laurent M. 
Published: February 2019

ABSTRACTIn this study, we assessed the influence of cellulose nanocrystal (CNC) addition level (0.5–2 wt %) on the surface texture, thickness, and barrier properties of poly(lactic acid) (PLA) extruded‐cast films. Regardless of the CNC content, the addition of CNC increased the surface average roughness and maximum roughness of the PLA films in both the machine and cross‐machine directions because of the presence of CNC agglomerates. The increased roughness resulted in films with uneven thicknesses; this affected their accurate measurements with a conventional micrometer. Rather, accurate thickness measurements were obtained through the density method, a more appropriate thickness measurement method for films with rough surfaces. The permeability values were negatively correlated with the increased crystallinity. Both the water vapor permeability and oxygen permeability (OP) values decreased significantly by approximately 26–45 and 25–50%, respectively, as the CNC content increased from 0.5 to 2 wt % because of the tortuosity effect. The OP values of the neat PLA and composite films remained insensitive to changes in the relative humidity (from 0 to 75%) when they were tested at 23 °C. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47594.
The discovery and characterization of K‐563, a novel inhibitor of the Keap1/Nrf2 pathway produced by Streptomyces sp
Authors: Hori Ran , Yamaguchi Kozo , Sato Hidetaka , Watanabe Miwa , Tsutsumi Kyoko , Iwamoto Susumu , Abe Masayuki , Onodera Hideyuki , Nakamura Satoshi , Nakai Ryuichiro 
Published: February 2019

AbstractKeap1/Nrf2 pathway regulates the antioxidant stress response, detoxification response, and energy metabolism. Previous reports found that aberrant Keap1/Nrf2 pathway activation due to Kelch‐like ECH‐associated protein 1 (Keap1) mutations or Nuclear factor E2‐related factor 2 (Nrf2) mutations induced resistance of cancer cells to chemotherapy and accelerated cell growth via the supply of nutrients. Therefore, Keap1/Nrf2 pathway activation is associated with a poor prognosis in many cancers. These previous findings suggested that inhibition of Keap1/Nrf2 pathway could be a target for anti‐cancer therapies. To discover a small‐molecule Keap1/Nrf2 pathway inhibitor, we conducted high‐throughput screening in Keap1 mutant human lung cancer A549 cells using a transcriptional reporter assay. Through this screening, we identified the novel Keap1/Nrf2 pathway inhibitor K‐563, which was isolated from actinomycete Streptomyces sp. K‐563 suppressed the expression of Keap1/Nrf2 pathway downstream target genes or the downstream target protein, which induced suppression of GSH production, and activated reactive oxygen species production in A549 cells. K‐563 also inhibited the expression of downstream target genes in other Keap1‐ or Nrf2‐mutated cancer cells. Furthermore, K‐563 exerted anti‐proliferative activities in these mutated cancer cells. These in vitro analyses showed that K‐563 was able to inhibit cell growth in Keap1‐ or Nrf2‐mutated cancer cells by Keap1/Nrf2 pathway inhibition. K‐563 also exerted synergistic combinational effects with lung cancer chemotherapeutic agents. An in vivo study in mice xenotransplanted with A549 cells to further explore the therapeutic potential of K‐563 revealed that it also inhibited Keap1/Nrf2 pathway in lung cancer tumors. K‐563, a novel Keap1/Nrf2 pathway inhibitor, may be a lead compound for development as an anti‐cancer agent.