bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemoenzymatic Synthesis of Complex N‐Glycans of the Parasite S. mansoni to Examine the Importance of Epitope Presentation on DC‐SIGN recognition
Authors: Srivastava Apoorva D. , Unione Luca , Bunyatov Mehman , Gagarinov Ivan A. , Delgado Sandra , Abrescia Nicola G. A. , Ardá Ana , Boons Geert‐Jan 
Published: June 2021

AbstractThe importance of multivalency for N‐glycan‐protein interactions has primarily been studied by attachment of minimal epitopes to artificial multivalent scaffold and not in the context of multi‐antennary glycans. N‐glycans can be modified by bisecting GlcNAc, core xylosides and fucosides, and extended N‐acetyl lactosamine moieties. The impact of such modifications on glycan recognition are also not well understood. We describe here a chemoenzymatic methodology that can provide N‐glycans expressed by the parasitic worm S. mansoni having unique epitopes at each antenna and containing core xyloside. NMR, computational and electron microscopy were employed to investigate recognition of the glycans by the human lectin DC‐SIGN. It revealed that core xyloside does not influence terminal epitope recognition. The multi‐antennary glycans bound with higher affinity to DC‐SIGN compared to mono‐valent counterparts, which was attributed to proximity‐induced effective concentration. The multi‐antennary glycans cross‐linked DC‐SIGN into a dense network, which likely is relevant for antigen uptake and intracellular routing.
Large‐Scale Synthesis of Functionalized Nanowires to Construct Nanoelectrodes for Intracellular Sensing
Authors: Wu Wen‐Tao , Jiang Hong , Qi Yu‐Ting , Fan Wen‐Ting , Yan Jing , Liu Yan‐Ling , Huang Wei‐Hua 
Published: June 2021

AbstractA strategy for one‐pot and large‐scale synthesis of functionalized core–shell nanowires (NWs) to high‐efficiently construct single nanowire electrodes is proposed. Based on the polymerization reaction between 3,4‐ethylenedioxythiophene (EDOT) and noble metal cations, manifold noble metal nanoparticles‐polyEDOT (PEDOT) nanocomposites can be uniformly modified on the surface of any nonconductive NWs. This provides a facile and versatile approach to produce massive number of core–shell NWs with excellent conductivity, adjustable size, and well‐designed properties. Nanoelectrodes manufactured with such core–shell NWs exhibit excellent electrochemical performance and mechanical stability as well as favorable antifouling properties, which are demonstrated by in situ intracellular monitoring of biological molecules (nitric oxide) and unraveling its relevant unclear signaling pathway inside single living cells.
Heteroleptische Koordination durch einen endo‐funktionalisierten Käfig
Authors: Bete Sarah C. , Otte Matthias 
Published: June 2021

AbstractEin konzeptioneller Ansatz für die Synthese von quasi‐heteroleptischen Komplexen auf der Basis von endo‐funktionalisierten organischen Käfigen wird vorgestellt. Die Synthese des Liganden erfolgt über einen dynamisch kombinatorischen Ansatz und bedient sich eines maskierten Amins. Inspiriert von der facialen Triade in den aktiven Zentren diverser Enzyme besitzt dieser eine Carboxylat‐ und zwei Imidazolfunktionen als koordinierende Einheiten. Untersuchungen der FeII‐ und ZnII‐Komplexe bestätigen die angestrebte Struktur und insbesondere auch, dass keine unerwünschte, jedoch bei klassischen biomimetischen Komplexen oft beobachtete Dimerisierung stattfindet. Die Kristallstruktur des Eisen‐Triethylamin‐Komplexes zeigt ein fünffach koordiniertes Metallzentrum mit zweizähniger Anbindung des Carboxylatliganden, wodurch Fe@2 eine beispiellos genaue strukturelle Nachbildung von dieser Art von nicht‐Häm‐Eisenoxygenasen darstellt. Da, wie in der Kristallstruktur zu sehen, innerhalb der Kavität genug Platz für die Koordination externer Liganden möglich ist, wird der in diesem Kontext biologisch relevante Ligand α‐Ketoglutarat eingeführt, was in biomimetischer Reaktivität gegenüber Sauerstoff resultiert.
Sodium‐Decorated Amorphous/Crystalline RuO2 with Rich Oxygen Vacancies: A Robust pH‐Universal Oxygen Evolution Electrocatalyst
Authors: Zhang Lijie , Jang Haeseong , Liu Huihui , Kim Min Gyu , Yang Dongjiang , Liu Shangguo , Liu Xien , Cho Jaephil 
Published: June 2021

AbstractThe oxygen evolution reaction (OER) is a key reaction for many electrochemical devices. To date, many OER electrocatalysts function well in alkaline media, but exhibit poor performances in neutral and acidic media, especially the acidic stability. Herein, sodium‐decorated amorphous/crystalline RuO2 with rich oxygen vacancies (a/c‐RuO2) was developed as a pH‐universal OER electrocatalyst. The a/c‐RuO2 shows remarkable resistance to acid corrosion and oxidation during OER, which leads to an extremely high catalytic stability, as confirmed by a negligible overpotential increase after continuously catalyzing OER for 60 h at pH=1. Besides, a/c‐RuO2 also exhibits superior OER activities to commercial RuO2 and most reported OER catalysts under all pH conditions. Theoretical calculations indicated that the introduction of Na dopant and oxygen vacancy in RuO2 weakens the adsorption strength of the OER intermediates by engineering the d‐band center, thereby lowering the energy barrier for OER.
Total Structure of Bimetallic Core–Shell [Au42Cd40(SR)52]2− Nanocluster and Its Implications
Authors: Tang Li , Ma Along , Zhang Cheng , Liu Xuguang , Jin Rongchao , Wang Shuxin 
Published: June 2021

AbstractBimetallic core–shell nanostructures hold great promise in elucidating the bimetallic synergism. However, it remains a challenge to construct atomically precise core–shell with high‐valence active metals on the gold surface. In this work, we report the total structure of a [Au42Cd40(SR)52]2− core–shell nanocluster and multiple implications. Single crystal X‐ray diffraction (SCXRD) reveals that the structure possesses a two‐shelled Au6@Au36 core and a closed cadmium shell of Cd40, and the core–shell structure is then protected by 52 thiolate (‐SR) ligands. The composition of the nanocluster is further confirmed by electrospray ionization mass spectrometry (ESI‐MS). A catalytic test for styrene oxidation and a comparison with relevant nanoclusters reveal the surface effect on the catalytic activity and selectivity.
A Primary Acyl Phosphine Stabilized by a Phosphonium Ylide
Authors: Petrone David A. , Szkop Kevin M. , Miao Linkun , St. Onge Piers , Qu Zheng‐Wang , Grimme Stefan , Stephan Douglas W. 
Published: June 2021

AbstractPrimary acyl‐phosphines are scarce in the literature. Here we show that the reaction of Ph3GePCO with the ylide Ph3PCH2proceeds to give the species Ph3PCHC(O)PH(GePh3)1. Deprotonation of1with Na[N(SiMe3)2] generates the salt [Na(THF)2][Ph3PCHC(O)P(GePh3)]2which provides subsequent access to thebis‐germanylated acylphosphine, Ph3PCHC(O)P(GePh3)23. Alternatively, treatment of1with HCl in dioxane affords the primary acylphosphine Ph3PCHC(O)PH24. Compound4is a rare example of an air stable primary acyl‐phosphines and the first devoid of a stabilizing heteroatom adjacent to the carbonyl fragment.
In Situ Implanting of Single Tungsten Sites into Defective UiO‐66(Zr) by Solvent‐Free Route for Efficient Oxidative Desulfurization at Room Temperature
Authors: Ye Gan , Wang Hanlu , Chen Wenxing , Chu Hongqi , Wei Jinshan , Wang Dagang , Wang Jin , Li Yadong 
Published: June 2021

AbstractDesign of single‐site catalysts with catalytic sites at atomic‐scale and high atom utilization, provides new opportunities to gain superior catalytic performance for targeted reactions. In this contribution, we report a one‐pot green approach for in situ implanting of single tungsten sites (up to 12.7 wt.%) onto the nodes of defective UiO‐66(Zr) structure via forming Zr‐O‐W bonds under solvent‐free condition. The catalysts displayed extraordinary activity for the oxidative removal of sulfur compounds (1000 ppm S) at room temperature within 30 min. The turnover frequency (TOF) value can reach 44.0 h−1 at 30 °C, which is 109.0, 12.3 and 1.2 times higher than that of pristine UiO‐66(Zr), WO3, and WCl6 (homogeneous catalyst). Theoretical and experimental studies show that the anchored W sites can react with oxidant readily and generate WVI‐peroxo intermediates that determine the reaction activity. Our work not only manifests the application of SSCs in the field of desulfurization of fuel oil but also opens a new solvent‐free avenue for fabricating MOFs based SSCs.
Visible‐Light‐Enabled Organocatalyzed Controlled Alternating Terpolymerization of Perfluorinated Vinyl Ethers
Authors: Quan Qinzhi , Ma Mingyu , Wang Zongtao , Gu Yu , Chen Mao 
Published: June 2021

AbstractPolymerizations of perfluorinated vinyl ethers (PFVEs) provide an important category of fluoropolymers that have received considerable interests in applications. In this work, we report the development of an organocatalyzed controlled radical alternating terpolymerization of PFVEs and vinyl ethers (VEs) under visible‐light irradiation. This method not only enables the synthesis of a broad scope of fluorinated terpolymers of low dispersities and high chain‐end fidelity, facilitating tuning the chemical compositions by rationally choosing the type and/or ratio of comonomers, but also allows temporal control of chain‐growth, as well as the preparation of a variety of novel fluorinated block copolymers. To showcase the versatility of this method, fluorinated alternating terpolymers have been synthesized and customized to simultaneously display a variety of desirable properties for solid polymer electrolyte design, creating new opportunities in high‐performance energy storage devices.
Heteroleptic Ligation by an endo‐Functionalized Cage
Authors: Bete Sarah C. , Otte Matthias 
Published: June 2021

AbstractA conceptual approach for the synthesis of quasi‐heteroleptic complexes with properly endo‐functionalized cages as ligands is presented. The cage ligand reported here is of a covalent organic nature, it has been synthesized via a dynamic combinatorial chemistry approach, making use of a masked amine. Inspired by enzymatic active sites, the described system bears one carboxylate and two imidazole moieties as independent ligating units through which it is able to coordinate to transition metals. Analysis of the iron(II) complex in solution and the solid state validates the structure and shows that no undesired but commonly observed dimerization process takes place. The solid‐state structure shows a five‐coordinate metal center with the carboxylate bidentately bound to iron, which makes Fe@2 an unprecedentedly detailed structural model complex for this kind of non‐heme iron oxygenases. As, as confirmed by the crystal structure, sufficient space for other organic ligands is available, the biologically relevant ligand α‐ketoglutarate is implemented. We observe biomimetic reaction behavior towards dioxygen that opens studies investigating Fe@2 as a functional model complex.
Polishing entire stems and roots using sandpaper under water: An alternative method for macroscopic analyses
Authors: Barbosa Antonio C. F. , Gerolamo Caian S. , Lima André C. , Angyalossy Veronica , Pace Marcelo R. 
Published: June 2021

PremisePolishing entire stem and root samples is an effective method for studying their anatomy; however, polishing fresh samples to preserve woods with soft tissues or barks is challenging given that soft tissues shrink when dried. We propose sanding fresh or liquid‐preserved samples under water as an alternative, given that it preserves all tissues in an intact and clear state.Methods and ResultsBy manually grinding the surface of the samples under water using three ascending grits of waterproof sandpapers, an excellent polished sanded surface is obtained. The wood swarf goes into the water without clogging the cell lumina, rendering the surfaces adequate for cell visualization and description. We show results in palms, liana stems, roots, and wood blocks.ConclusionsUsing this simple, inexpensive, rapid technique, it is possible to polish either fresh, dry, or liquid‐preserved woody plant samples, preserving the integrity of both the soft and hard tissues and allowing for detailed observations of the stems and roots.
A bridge too far for artificial intelligence?: Automatic classification of stanzas in Spanish poetry
Authors: Pérez Pozo Álvaro , de la Rosa Javier , Ros Salvador , González‐Blanco Elena , Hernández Laura , de Sisto Mirella 
Published: June 2021

AbstractThe rise in artificial intelligence and natural language processing techniques has increased considerably in the last few decades. Historically, the focus has been primarily on texts expressed in prose form, leaving mostly aside figurative or poetic expressions of language due to their rich semantics and syntactic complexity. The creation and analysis of poetry have been commonly carried out by hand, with a few computer‐assisted approaches. In the Spanish context, the promise of machine learning is starting to pan out in specific tasks such as metrical annotation and syllabification. However, there is a task that remains unexplored and underdeveloped: stanza classification. This classification of the inner structures of verses in which a poem is built upon is an especially relevant task for poetry studies since it complements the structural information of a poem. In this work, we analyzed different computational approaches to stanza classification in the Spanish poetic tradition. These approaches show that this task continues to be hard for computers systems, both based on classical machine learning approaches as well as statistical language models and cannot compete with traditional computational paradigms based on the knowledge of experts.
Graphite Carbon Nitride and Its Composites for Medicine and Health Applications
Authors: Zhang Jie‐ran , Kan Yin‐shi , Gu Ling‐ling , Wang Cheng‐yin , Zhang Yu 
Published: June 2021

AbstractWith the progress of science and technology and the improvement of people‘s living standards, the performance of traditional materials can no longer fully meet the needs of social development. Graphitic phase carbon nitride (g‐C3N4), as a new type of nanomaterial, has good properties. Its unique graphite like structure and stable thermodynamic characteristics have led an increasing number of researchers to explore its diverse functions and use this as a basis to develop related energy and products for applications in various fields. Among them, applications in the field of medicine health have become popular in recent years. Therefore, this review summarizes the synthesis methods of g‐C3N4 and its composites, as well as their applications in food, medicine, environmental monitoring and disease treatment, in the hope of providing references and basis for further expanding the applications of g‐C3N4 in large health areas.
Targeted CHO cell engineering approaches can reduce HCP‐related enzymatic degradation and improve mAb product quality
Authors: Dovgan Tatiana , Golghalyani Vahid , Zurlo Fabio , Hatton Diane , Lindo Viv , Turner Richard , Harris Claire , Cui Tingting 
Published: June 2021

AbstractHost cell proteins (HCP) that co‐purify with biologics produced in Chinese hamster ovary cells have been shown to impact product quality through proteolytic degradation of recombinant proteins, leading to potential product losses. Several problematic HCPs can remain in the final product even after extensive purification. Each recombinant cell line has a unique HCP profile that can be determined by numerous upstream and downstream factors, including clonal variation and the protein sequence of the expressed therapeutic molecule. Here, we worked with recombinant cell lines with high levels of copurifying HCPs, and showed that in those cell lines even modest downregulation (≤50%) of the difficult to remove HCP Cathepsin D, through stable short hairpin RNA interference or monoallelic deletion of the target gene using CRISPR‐Cas9, is sufficient to greatly reduce levels of co‐purifying HCP as measured by high throughput targeted LC‐MS. This reduction led to improved product quality by reducing fragmentation of the drug product in forced degradation studies to negligible levels. We also show the potential of cell engineering to target other undesired HCPs and relieve the burden on downstream purification.
Molecular genetic analysis of neural stem cells after space flight and simulated microgravity on earth
Authors: Han Yilin , Zeger Lukas , Tripathi Rekha , Egli Marcel , Ille Fabian , Lockowandt Christian , Florin Gunnar , Atic Edvin , Redwan Itedale N. , Fredriksson Robert , Kozlova Elena N. 
Published: June 2021

AbstractUnderstanding how stem cells adapt to space flight conditions is fundamental for human space missions and extraterrestrial settlement. We analyzed gene expression in boundary cap neural crest stem cells (BCs), which are attractive for regenerative medicine by their ability to promote proliferation and survival of cocultured and co‐implanted cells. BCs were launched to space (space exposed cells) (SEC), onboard sounding rocket MASER 14 as free‐floating neurospheres or in a bioprinted scaffold. For comparison, BCs were placed in a random positioning machine (RPM) to simulate microgravity on earth (RPM cells) or were cultured under control conditions in the laboratory. Using next‐generation RNA sequencing and data post‐processing, we discovered that SEC upregulated genes related to proliferation and survival, whereas RPM cells upregulated genes associated with differentiation and inflammation. Thus, (i) space flight provides unique conditions with distinctly different effects on the properties of BC compared to earth controls, and (ii) the space flight exposure induces postflight properties that reinforce the utility of BC for regenerative medicine and tissue engineering.
Determination of bupivacaine tissue concentration in human biopsy samples using high‐performance liquid chromatography with mass spectrometry
Authors: Istenič Simon , Cvetko Erika , Zabret Joži , Stopar Pintarič Tatjana , Umek Nejc 
Published: June 2021

AbstractIn the present study, we developed a simple and rapid analytical method for the quantification of bupivacaine hydrochloride in human biopsy samples of adipose, muscle, neural, connective and cartilage tissue using liquid chromatography‐mass spectrometry. Anesthetics were extracted from the tissue samples using 0.1% formic acid in acetonitrile for protein denaturation and hexane for removal of lipophilic impurities. Analytes were separated adequately on Phenomenex Luna Omega polar C18 column using a gradient mobile phase 0.1% formic acid in water and 0.1% formic acid in acetonitrile. The lower limits of quantification were ≤ 97 ng g−1tissue for all studied tissues. Intra‐day recoveries were between 48.2% and 82.1% with relative standard deviations (RSDs) between 1.47% and 14.28%, whereas inter‐day recoveries were between 52.2% and 77.6% with RSDs between 2.98% and 14.79%. The calibration curve showed a linear fit with R2higher than 0.99 in the concentration range from 0.16 to 100 μg g−1. Lidocaine hydrochloride was tested as internal standard because its recoveries and matrix effects were comparable to bupivacaine hydrochloride. Post‐analytical corrections of measured bupivacaine tissue concentrations can accordingly be made based on recovery of lidocaine as internal standard, with recoveries between 51.2% and 86.9% and RSDs between 1.99% and 16.88%. The developed method could be used to study time‐dependent spread of bupivacaine locally or to more distant locations across tissue barriers.
Brain functional changes in patients with Crohn's disease: A resting‐state fMRI study
Authors: Li Lu , Ma Jie , Xu Jian‐Guang , Zheng Yan‐Ling , Xie Qian , Rong Lan , Liang Zong‐Hui 
Published: June 2021

AbstractBackgroundCrohn's disease (CD) is a chronic recurrent intestinal inflammatory disease, often accompanied by poor adaptation and excessive stress response. However, the potential neurological mechanisms of these symptoms have not yet been studied in‐depth.ObjectiveTo investigate alterations in brain activity in patients with Crohn's disease and study the relationship between altered regions and clinical indices.MethodsA total of 15 CD patients and 26 matched healthy controls were recruited. All participants underwent fMRI scans. The amplitude of low‐frequency fluctuations (ALFF) and regional homogeneity (ReHo) assessed differences in spontaneous regional brain activity. Differences between the groups were selected as seeds for functional connectivity (FC) analyses. Correlations between disease duration and ALFF/ReHo/FC values in abnormal regions were analyzed.ResultsPatients with CD had significantly higher ALFF values in the left superior frontal gyrus, anterior cingulate cortex, and supplementary motor area, and lower values in the left hippocampus. They also had higher ReHo values in the left anterior cingulate cortex, supplementary motor area, putamen, and the bilateral superior frontal gyri. FC strength in the left precentral and middle temporal gyri was found to be increased when the left superior frontal gyrus was used as the seed point. FC strength was also observed to be increased in the left postcentral, middle frontal gyri, inferior frontal orbital cortex, and right rolandic operculum when the left anterior cingulate cortex was used as the seed point.ConclusionCD demonstrated abnormal neural activity and FC in various regions primarily associated with emotional, pain and cognitive‐related functions, which provides more information to further understand the neural mechanisms of the disease.
Psychometric properties of a patient‐reported outcome set in acute stroke patients
Authors: Philipp Rebecca , Lebherz Lisa , Thomalla Götz , Härter Martin , Appelbohm Hannes , Frese Marc , Kriston Levente 
Published: June 2021

AbstractObjectivesImpairments after stroke may affect multiple domains of health‐related quality of life (HRQoL). Patient‐reported outcome measures (PROMs) have proven valuable in measuring patients’ well‐being. We examine the psychometric properties of a standard set of PROMs assessing global health, anxiety, and depression, and functioning in a German health care setting.MethodWe included inpatients at the Department of Neurology at the University Medical Center Hamburg‐Eppendorf, diagnosed with stroke. Following the stroke‐specific standard set of the International Consortium for Health Outcome Measurement, we collected demographic and clinical information at baseline, and PROMs for global health (PROMIS‐10), three items for self‐reported functioning, anxiety, and depression (PHQ‐4) at 90 days follow‐up. We calculated confirmatory factor analyses to test factorial validity and correlation analyses to test construct validity. We further conducted item and reliability analyses.ResultsIn a sample of 487 patients (mean age, SD: 71.1, 12.6; 47% female) with mild and moderate symptoms, model fit for the PROMIS‐10 was acceptable for the two‐factor and single‐factor models. Factor loadings ranged from 0.52 to 0.94. The postulated single‐factor model for functioning was saturated with zero degrees of freedom. Factor loadings ranged from 0.90 to 0.96. For the PHQ‐4, the two‐factor model showed excellent model fit. Factor loadings ranged from 0.78 to 0.87. Internal consistency was acceptable to good. Construct validity was generally confirmed.ConclusionsThe PROMIS‐10 is a valid and reliable instrument to measure HRQoL among German stroke patients. While the PHQ‐4 was confirmed as a screening measure for mental disorders, further research is needed on items assessing self‐reported functioning. Results are limited to patients showing minimal functional deficits.