bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chiral Recognition on Bare Gold Surfaces by Quartz Crystal Microbalance
Authors: Xiao Xiangyun , Chen Chao , Zhang Yehao , Kong Huihui , An Rong , Li Shuang , Liu Wei , Ji Qingmin 
Published: September 2021

AbstractQuartz crystal microbalance (QCM) is one of the powerful tools for the studies of molecular recognition and chiral discrimination. Its efficiency mainly relies on the design of the functional sensitive layer on the electrode surface. However, the organic sensitive layer may easily cause dissipation of oscillation or detachment and weaken the signal transfer during the molecular recognition processes. In this work, we reveal for the first time that the bare metal surface without the organic selector layer has the capability for chiral recognition in the QCM system. During the adsorption of various chiral amino acids, relatively higher selectivity of D‐enantiomers on gold (Au) surface was shown by the QCM detection. Based on analyses of the surface crystalline structure and density functional theory calculations, we demonstrate that the chiral nature of Au surface plays an important role in the selective binding of specific D‐amino acids. These results may open new insights on chiral detection by QCM system. It will also promote the construction of novel chiral sensing systems with both efficient detection and separation capability.
Stabilization of Reactive Nitrene by Silylenes without Using a Reducing Metal
Authors: Ding Yi , Sarkar Samir Kumar , Nazish Mohd , Muhammed Shahila , Lüert Daniel , Ruth Paul Niklas , Legendre Christina M. , Herbst‐Irmer Regine , Parameswaran Pattiyil , Stalke Dietmar , Yang Zhi , Roesky Herbert W. 
Published: September 2021

AbstractHerein, we report the stabilization of nitrene reagents as the source of a nitrogen atom to synthesize nitrogen‐incorporated R1LSi‐N←SiLR2 (1) [L=PhC(NtBu)2; R1=NTMS2, R2=NTMS]. Compound 1 is synthesized by reacting LSi(I)‐SiIL with 3.1 equivalents of Me3SiN3 at low temperature to afford a triene‐like structural framework. Whereas the reaction of the LSi(I)‐SiIL with 2.1 equivalents of Me3SiN3 at room temperature produced silaimine 2 with a central four‐membered Si2N2 ring which is accompanied by a silylene LSi and a cleaved silylene fragment. 1 further reacts with AgOTf at room temperature to yield compound 3 which shows coordination of nitrene to silver with the triflate salt. The compounds 1 and 2 were fully characterized by NMR, mass spectrometry, and X‐ray crystallographic analysis. The quantum mechanical calculations reveal that compounds 1 and 2 have dicoordinated monovalent N atoms having two active lone pairs of electrons. These lone pairs are stabilized by hyperconjugative interactions.
On‐Surface Synthesis of a Dicationic Diazahexabenzocoronene Derivative on the Au(111) Surface
Authors: Biswas Kalyan , Urgel José I. , Xu Kun , Ma Ji , Sánchez‐Grande Ana , Mutombo Pingo , Gallardo Aurelio , Lauwaet Koen , Mallada Benjamin , de la Torre Bruno , Matěj Adam , Gallego José M. , Miranda Rodolfo , Jelínek Pavel , Feng Xinliang , Écija David 
Published: September 2021

AbstractThe atomically precise control over the size, shape and structure of nanographenes (NGs) or the introduction of heteroatom dopants into their sp2‐carbon lattice confer them valuable electronic, optical and magnetic properties. Herein, we report on the design and synthesis of a hexabenzocoronene derivative embedded with graphitic nitrogen in its honeycomb lattice, achieved via on‐surface assisted cyclodehydrogenation on the Au(111) surface. Combined scanning tunnelling microscopy/spectroscopy and non‐contact atomic force microscopy investigations unveil the chemical and electronic structures of the obtained dicationic NG. Kelvin probe force microscopy measurements reveal a considerable variation of the local contact potential difference toward lower values with respect to the gold surface, indicative of its positive net charge. Altogether, we introduce the concept of cationic nitrogen doping of NGs on surfaces, opening new avenues for the design of novel carbon nanostructures.
Block Copolymers Based on Ethylene and Methacrylates Using a Combination of Catalytic Chain Transfer Polymerisation (CCTP) and Radical Polymerisation
Authors: Baffie Florian , Patias Georgios , Shegiwal Ataulla , Brunel Fabrice , Monteil Vincent , Verrieux Ludmilla , Perrin Lionel , Haddleton David M. , D'Agosto Franck 
Published: September 2021

AbstractTwo scalable polymerisation methods are used in combination for the synthesis of ethylene and methacrylate block copolymers. ω‐Unsaturated methacrylic oligomers (MMAn) produced by catalytic chain transfer (co)polymerisation (CCTP) of methyl methacrylate (MMA) and methacrylic acid (MAA) are used as reagents in the radical polymerisation of ethylene (E) in dimethyl carbonate solvent under relatively mild conditions (80 bar, 70 °C). Kinetic measurements and analyses of the produced copolymers by size exclusion chromatography (SEC) and a combination of nuclear magnetic resonance (NMR) techniques indicate that MMAn is involved in a degradative chain transfer process resulting in the formation of (MMA)n‐b‐PE block copolymers. Molecular modelling performed by DFT supports the overall reactivity scheme and observed selectivities. The effect of MMAn molar mass and composition is also studied. The block copolymers were characterised by differential scanning calorimetry (DSC) and their bulk behaviour studied by SAXS/WAXS analysis.
Relationship between microstructure evolution and properties enhancement of carbon nanotubes‐filled polybutylene terephthalate/polypropylene blends induced by thermal annealing
Authors: Shang Mengyao , Gao Zhuyi , Cheng Henglun , Wu Chinan , Shentu Baoqing 
Published: September 2021

AbstractThermal annealing induced microstructure evolution and properties enhancement of polybutylene terephthalate/polypropylene/carbon nanotubes (PBT/PP/CNTs) nanocomposites was methodically investigated. The electrical conductive PBT/PP/CNTs nanocomposites with a low percolation threshold were obtained by simple melt blending due to the selective location of the CNTs in PBT phase and the formation of the double percolation structure. Thermal annealing further remarkably decreased the volume resistivity of the nanocomposites, with the maximum reduction of seven orders of magnitude. Scanning electron microscope observation and rheology tests demonstrated that the relatively large CNTs agglomerates were redistributed to build more homogeneous CNTs networks after annealing. The phase coalescence during annealing promoted the formation of the more perfect co‐continuous structure. These phenomena helped to enhance the electrical conductivity of the nanocomposites. Flexural properties of the nanocomposites were also enhanced after annealing, which might be due to the more effective stress transfer between the polymer and CNTs induced by the reconstructed CNTs networks. The nanocomposites obtained in this study possess excellent electrical and mechanical properties, which can be applied to the fields of sensors, electromagnetic interference shielding, anti‐static materials, and so forth.
Identification of additional young nearby runaway stars based on Gaia data release 2 observations and the lithium test
Authors: Bischoff Richard , Mugrauer Markus , Torres Guillermo , Geymeier Michael , Neuhäuser Ralph , Stenglein Wolfgang , Michel Kai‐Uwe 
Published: September 2021

AbstractRunaway stars are characterized by their remarkably high space velocities, and the study of their formation mechanisms has attracted considerable interest. Young, nearby runaway stars are the most favorable for identifying their place of origin, and for searching for possible associated objects such as neutron stars. Usually, the research field of runaway stars focuses on O‐ and B‐type stars, because these objects are better detectable at larger distances than late‐type stars. Early‐type runaway stars have the advantage that they evolve faster and can therefore better be confirmed to be young. In contrast to this, the catalog of Young runaway stars within 3 kpc by Tetzlaff, N., Neuhäuser, R., & Hohle, M. M. (2011, MNRAS, 410(1), 190–200) contains also stars of spectral type A and later. The objects in this catalog were originally classified as young ( Myr) runaway stars by using Hipparcos data to estimate the ages from their location in the Hertzsprung‐Russell diagram and evolutionary models. In this article, we redetermine and/or constrain their ages not only by using the more precise second data release of the Gaia mission, but also by measuring the equivalent width of the lithium (6,708 Å) line, which is a youth indicator. Therefore, we searched for lithium absorption in the spectra of 51 target stars, taken at the University Observatory Jena between March and September 2020 with the Échelle spectrograph FLECHAS, and within additional TRES‐spectra from the Fred L. Whipple Observatory. The main part of this campaign with its 308 reduced spectra, accessible at VizieR, was already published. In this work, which is the continuation and completion of the in 2015 initiated observing campaign, we found three additional young runaway star candidates.
Identification of colon tumor marker NKD1 via integrated bioinformatics analysis and experimental validation
Authors: Wang Yue , Yang Chunxia , Li Wenjing , Shen Ying , Deng Jianzhong , Lu Wenbin , Jin Jianhua , Liu Yongping , Liu Qian 
Published: September 2021

AbstractBackgroundColorectal cancer is an important death‐related disease in the worldwide. However, specific colon cancer tumor markers currently used for diagnosis and treatment are few. The purpose of this study is to screen the potential colon cancer markers by bioinformatics and verify the results with experiments.MethodsGene expression data were downloaded from two different databases: TCGA database and GEO datasets, which were then analyzed by two different methods (difference analysis and WGCNA method). Venn and PPI analysis obtained the potential core genes, which were then performed the GO enrichment and KEGG pathway analysis. Expressions levels of NKD1 in colon carcinoma tissues were further confirmed by immunohistochemical staining and western blot assays. Moreover, the function was measured by MTT, clone formation, and tumor transplantation experiments. Importantly, co‐immunoprecipitation, immunofluorescence, and protein stability assays were further performed to explore the underlying mechanism of NKD1 promoting cell proliferation.ResultsNine potential core genes highly expressed in colon cancer samples were screened out by bioinformatics analysis. NKD1, one of the hub genes, highly expressed in the colon carcinoma tissues could enhance the proliferation of colon cancer cells. Mechanism research demonstrated that NKD1 was essential for the combination between Wnt signalosome (DVL) and β‐catenin, and that NKD1 knockout remarkably decreased the β‐catenin expression. Immunofluorescence assays further implied that NKD1 knockout significantly inhibited β‐catenin nuclear accumulation. Importantly, the stability of β‐catenin proteins was maintained by NKD1 in the colon cancer cells.ConclusionWe believe that NKD1 well expressed in the colorectal carcinoma tissues can enhance the proliferation of colon cancer cells. Furthermore, the functions that NKD1 may have in colon cancer cells should be different from that NKD1 has played in the zebrafish. Thus, NKD1 could be a specific colorectal cancer marker.
Identification and Composition of Clasper Scent Gland Components of the Butterfly Heliconius erato and Its Relation to Mimicry
Authors: Ehlers Stephanie , Szczerbowski Daiane , Harig Tim , Stell Matthew , Hötling Susan , Darragh Kathy , Jiggins Chris D. , Schulz Stefan 
Published: September 2021

AbstractThe butterfly Heliconius erato occurs in various mimetic morphs. The male clasper scent gland releases an anti‐aphrodisiac pheromone and additionally contains a complex mixture of up to 350 components, varying between individuals. In 114 samples of five different mimicry groups and their hybrids 750 different compounds were detected by gas chromatography/mass spectrometry (GC/MS). Many unknown components occurred, which were identified using their mass spectra, gas chromatography/infrared spectroscopy (GC/IR)‐analyses, derivatization, and synthesis. Key compounds proved to be various esters of 3‐oxohexan‐1‐ol and (Z)‐3‐hexen‐1‐ol with (S)‐2,3‐dihydrofarnesoic acid, accompanied by a large variety of other esters with longer terpene acids, fatty acids, and various alcohols. In addition, linear terpenes with up to seven uniformly connected isoprene units occur, e. g. farnesylfarnesol. A large number of the compounds have not been reported before from nature. Discriminant analyses of principal components of the gland contents showed that the iridescent mimicry group differs strongly from the other, mostly also separated, mimicry groups. Comparison with data from other species indicated that Heliconius recruits different biosynthetic pathways in a species‐specific manner for semiochemical formation.
Thiophene‐Based Dual Modulators of Aβ and Tau Aggregation
Authors: Ramesh Madhu , Acharya Anand , Murugan N. Arul , Ila Hiriyakkanavar , Govindaraju Thimmaiah 
Published: September 2021

AbstractAlzheimer's disease is characterized by the accumulation of amyloid beta (Aβ) and Tau aggregates in the brain, which induces various pathological events resulting in neurodegeneration. There have been continuous efforts to develop modulators of the Aβ and Tau aggregation process to halt or modify disease progression. A few small‐molecule‐based inhibitors that target both Aβ and Tau pathology have been reported. Here, we report the screening of a targeted library of small molecules to modulate Aβ and Tau aggregation together with their in vitro, in silico and cellular studies. In vitro ThT fluorescence assay, dot blot assay, gel electrophoresis and transmission electron microscopy (TEM) results have shown that thiophene‐based lead molecules effectively modulate Aβ aggregation and inhibit Tau aggregation. In silico studies performed by employing molecular docking, molecular dynamics and binding‐free energy calculations have helped in understanding the mechanism of interaction of the lead thiophene compounds with Aβ and Tau fibril targets. In cellulo studies revealed that the lead candidate is biocompatible and effectively ameliorates neuronal cells from Aβ and Tau‐mediated amyloid toxicity.
Protein Design with Fluoroprolines: 4,4‐Difluoroproline Does Not Eliminate the Rate‐Limiting Step of Thioredoxin Folding
Authors: O' Loughlin Jennie , Napolitano Silvia , Rubini Marina 
Published: September 2021

AbstractC4‐substituted fluoroprolines (4R)‐fluoroproline ((4R)‐Flp) and (4S)‐fluoroproline ((4S)‐Flp) have been used in protein engineering to enhance the thermodynamic stability of peptides and proteins. The electron‐withdrawing effect of fluorine can bias the pucker of the pyrrolidine ring, influence the conformational preference of the preceding peptide bond, and can accelerate the cis/trans prolyl peptide bond isomerisation by diminishing its double bond character. The role of 4,4‐difluoroproline (Dfp) in the acceleration of the refolding rate of globular proteins bearing a proline (Pro) residue in the cis conformation in the native state remains elusive. Moreover, the impact of Dfp on the thermodynamic stability and bioactivity of globular proteins has been seldom described. In this study, we show that the incorporation of Dfp caused a redox state dependent and position dependent destabilisation of the thioredoxin (Trx) fold, while the catalytic activities of the modified proteins remained unchanged. The Pro to Dfp substitution at the conserved cisPro76 in the thioredoxin variant Trx1P did not elicited acceleration of the rate‐limiting trans‐to‐cis isomerization of the Ile75‐Pro76 peptide bond. Our results show that pucker preferences in the context of a tertiary structure could play a major role in protein folding, thus overtaking the rules determined for cis/trans isomerisation barriers determined in model peptides.
Comparative studies on physicochemical properties of rice with germinated dark purple giant embryo rice and normal embryo rice
Authors: Chung Soo Im , Kang Mi Young 
Published: September 2021

AbstractBackground and objectivesAs a cultivar developed by breeding, pigmented rice Keunnunjami has a dark purple pericarp and a giant embryo and has been found to possess strong antioxidant properties. The present study investigated the effect of 72‐hr germination on the physicochemical properties of Keunnunjami, in comparison with that of its parental pigmented normal embryo cultivar, Heukjinju, and ordinary normal brown rice.FindingsGermination generally increased the amounts of reducing sugar, amino acids isoleucine, leucine, phenylalanine, valine, alanine, cysteine, glycine, proline, and tyrosine, and minerals such as calcium, magnesium, and phosphorus while it decreased the levels of histidine, lysine, methionine, threonine, arginine, aspartic acid, glutamic acid, serine, and potassium in the rice grains. The germinated Keunnujami exhibited higher amounts of essential and non‐essential amino acids and reducing sugar than the germinated Heukjinju and normal brown rice. The starch granules from all rice samples showed holes and pits on the surface after germination.ConclusionsThese changes in the chemical composition and morphological properties are possibly due to partial hydrolysis of starch and protein caused by enzymes that were activated during germination.Significance and noveltyResults of this study could serve as the baseline information for evaluating the quality and possible food industry applications of germinated Keunnunjami.
The first description of a singular case of synchronous chronic myelomonocytic leukemia and diffuse large b‐cell lymphoma
Authors: Romano Alessandra , Giusti Michele , Di Giorgio MaryAnn , Lumera Giovanni , Laura Parrinello Nunziatina , Cosentino Sebastiano , Ippolito Massimo , Villari Loredana , Alberto Palumbo Giuseppe , Di Raimondo Francesco , Santo Signorelli Salvatore 
Published: September 2021

AbstractIn CMML, neoplastic monocytes can be distinguished based on their immunophenotype. Supportive care myeloid growth factors in concomitant extranodal non‐Hodgkin Lymphoma are safe.
Computational Analysis of Photophysical Properties and Reactivity of a New Phototherapeutic Cyclometalated Au(III)‐Hydride Complex
Authors: Scoditti Stefano , Mazzone Gloria , Sicilia Emilia 
Published: September 2021

AbstractGold(III) complexes have recently emerged as new versatile and efficacious metal containing anticancer agents. In an attempt to reconcile the specific affinity of such complexes for target sulfur containing biomolecules with their capability to strongly bind thiol‐containing compounds widely distributed in non‐tumoral cells, a new series of cyclometalated Au(III)‐hydride complexes has been proposed as photoactivatable anticancer prodrugs. Here, the computational exploration of the photophysical properties and reactivity in dark and under light irradiation of the first member of the series, named 1 a, is reported. Complex 1 a low hydricity in dark together with facile hydride substitution leading to H2 elimination under excitation by visible light have been examined by means of DFT and TD‐DFT computations. Both singlet and triplet excited states have been characterized, allowing the identification of the active species involved in photoactivation pathways leading to the controlled detachment of the hydride ligand. Also the viable two‐photon activation at the ideal phototherapeutic window has been investigated.
Microwave Spectrum of Two‐Top Molecule: 2‐Acetyl‐3‐Methylthiophene
Authors: Dindić Christina , Nguyen Ha Vinh Lam 
Published: September 2021

AbstractThe microwave spectrum of 2‐acetyl‐3‐methylthiophene (2A3MT) was recorded in the frequency range from 2 to 26.5 GHz using a molecular jet Fourier transform microwave spectrometer and could be fully assigned to the anti‐conformer of the molecule, while the syn‐conformer was not observable. Torsional splittings of all rotational transitions in quintets due to internal rotations of the acetyl methyl and the ring methyl groups were resolved and analyzed, yielding barriers to internal rotation of 306.184(46) cm−1 and 321.813(64) cm−1, respectively. The rotational and centrifugal distortion constants were determined with high accuracy, and the experimental values are compared to those derived from quantum chemical calculations. The experimentally determined inertial defect supports the conclusion that anti‐2A3MT is planar, even though a number of MP2 calculations predicted the contrary.
Implementing general environmental duties: Regulators' perceptions of complementary toolkits
Authors: Edwards Joel , Windholz Eric , Faulkner Nicholas , Werbeloff Lara 
Published: September 2021

AbstractStatutory general duties prioritise the prevention of harm, placing the onus for compliance on individuals and businesses alike to take steps to manage risks posed by their activities. In the case of general environmental duties specifically, they mandate that all parts of the community minimise the risk of environmental harm from their activities. However, encouraging compliant behaviour across such a diverse cohort is a significant challenge. To assist in meeting this challenge, general duties are supported by a variety of complementary regulatory tools. However, little is known about which complementary tools are used by regulators to support general environmental duties, and which factors may influence their application. This article addresses this knowledge gap, with a focus on Anglosphere countries where the use of statutory general duties is becoming increasingly popular. Through semi‐structured interviews with staff from environmental and occupational health and safety regulators, we demonstrate that the existence of a complementary tool does not necessarily mean it will be selected, and that staff responsible for the implementation of general duties are influenced by seven factors. These factors impact not only the selection of complementary tools, but when and how they are applied. The article concludes by discussing implications for practise and future research.
Aptamer‐functionalized Ti3C2‐MXene Nanosheets with One‐step Potentiometric Detection of Programmed Death‐ligand 1
Authors: Li Bin , Pu Wenyuan , Weng Lingyan , Lyu Peng , Xu Houxi , Zhang Wen , Ge Lilin , Kwok Hang Fai , Wu Qinan 
Published: September 2021

AbstractThis communication describes a simple sensitive one‐step potentiometric aptasensing method for quantitative detection of a referenced therapeutic biomarker (programmed death‐ligand 1, PD−L1). The aptasensor is constructed by modifying PD−L1‐specific aptamer on Ti3C2‐MXene nanosheets‐functionalized electrode. Introduction of PD−L1 induces the specific reaction between PD−L1 and aptamer, thereby resulting in the change of spatial structures. The surface electric potential of modified electrode is shifted upon addition of PD−L1 proteins before and after the reaction of aptamer with the analyte. Interestingly, potentiometric aptamer with Ti3C2‐MXene nanosheets can achieve a higher sensitivity and a lower detection limit toward target PD−L1 relative to aptamer‐modified electrode. Experimental results indicated that the linear range and detection limit of using Ti3C2‐MXene nanosheets were 0.01–100 ng mL−1 and 7.8 pg mL−1 PD−L1, respectively. Meanwhile, the specificity, reproducibility, storing stability and accuracy of potentiometric aptasensor are acceptable for the screening of PD−L1 in human serum samples.