bluuebunny/crossref_metadata_2025_split huggingface dataset:
Binding Motifs in the Naked Complexes of Target Amino Acids with an Excerpt of Antitumor Active Biomolecule: An Ion Vibrational Spectroscopy Assay
Authors: Chiavarino Barbara , Sinha Rajeev K. , Crestoni Maria Elisa , Corinti Davide , Filippi Antonello , Fraschetti Caterina , Scuderi Debora , Maitre Philippe , Fornarini Simonetta 
Published: November 2020

AbstractThe structures of proton‐bound complexes of 5,7‐dimethoxy‐4H‐chromen‐4‐one (1) and basic amino acids (AAs), namely, histidine (His) and lysine (Lys), have been examined by means of mass spectrometry coupled with IR ion spectroscopy and quantum chemical calculations. This selection of systems is based on the fact that 1 represents a portion of glabrescione B, a natural small molecule of promising antitumor activity, while His and Lys are protein residues lining the cavity of the alleged receptor binding site. These species are thus a model of the bioactive adduct, although clearly the isolated state of the present study bears little resemblance to the complex biological environment. A common feature of [1+AA+H]+ complexes is the presence of a protonated AA bound to neutral 1, in spite of the fact that the gas‐phase basicity of 1 is comparable to those of Lys and His. The carbonyl group of 1 acts as a powerful hydrogen‐bond acceptor. Within [1+AA+H]+ the side‐chain substituents (imidazole group for His and terminal amino group for Lys) present comparable basic properties to those of the α‐amino group, taking part to a cooperative hydrogen‐bond network. Structural assignment, relying on the comparative analysis of the infrared multiple photon dissociation (IRMPD) spectrum and calculated IR spectra for the candidate geometries, derives from an examination over two frequency ranges: 900–1800 and 2900–3700 cm−1. Information gained from the latter one proved especially valuable, for example, pointing to the contribution of species characterized by an unperturbed carboxylic OH or imidazole NH stretching mode.
Electrophilic and Nucleophilic Aromatic Substitutions are Mechanistically Similar with Opposite Polarity
Authors: Mąkosza Mieczysław 
Published: November 2020

AbstractConfrontation of the recently formulated general mechanism of nucleophilic substitution in electron‐deficient arenes with the well‐known mechanism of electrophilic substitution revealed that these fundamental processes are mechanistically identical but proceed according to opposite polarity—an Umpolung relation. In this viewpoint this apparently controversial concept is supported by discussion of a variety of experimental results.
Tuning the Organogelating and Spectroscopic Properties of a C3‐Symmetric Pyrene‐Based Gelator through Charge Transfer
Authors: Gainar Adrian , Lai Thanh‐Loan , Oliveras‐González Cristina , Pop Flavia , Raynal Matthieu , Isare Benjamin , Bouteiller Laurent , Linares Mathieu , Canevet David , Avarvari Narcis , Sallé Marc 
Published: November 2020

AbstractTwo‐component organogels and xerogels based on a C3‐symmetric pyrene‐containing gelator have been deeply characterized through a wide range of techniques. Based on the formation of charge transfer complexes, the gelation phenomenon proved to be highly dependent on the nature of the electron poor dopant. This parameter significantly influenced the corresponding gelation domains, the critical gelation concentrations of acceptor dopants, the gel‐to‐sol transition temperatures, the microstructures formed in the xerogel state and their spectroscopic properties. In particular, titrations and variable‐temperature UV–visible absorption spectroscopy demonstrated the key role of donor–acceptor interactions with a remarkable correlation between the phase transition temperatures and the disappearance of the characteristic charge transfer bands. The assignment of these electronic transitions was confirmed through time‐dependent density functional theory (TD‐DFT) calculations. Eventually, it was shown that the luminescent properties of these materials can be tuned with the temperature, either in intensity or emission wavelength.
The Photosensitizing Efficacy of Micelles Containing a Porphyrinic Photosensitizer and KI against Resistant Melanoma Cells
Authors: Castro Kelly A. D. F. , Costa Letícia D. , Prandini Juliana A. , Biazzotto Juliana C. , Tomé Augusto C. , Hamblin Michael R. , da Graça P. M. S. Neves Maria , Faustino M. Amparo F. , da Silva Roberto S. 
Published: November 2020

AbstractPhotodynamic therapy (PDT) is a promising alternative to overcome the resistance of melanoma to conventional therapies. Currently applied photosensitizers (PS) are often based on tetrapyrrolic macrocycles like porphyrins. Unfortunately, in some cases the use of this type of derivative is limited due to their poor solubility in the biological environment. Feasible approaches to surpass this drawback are based on lipid formulations. Besides that, and inspired in the efficacy of potassium iodide (KI) for antimicrobial photodynamic therapy (aPDT), the combined effect of singlet oxygen (1O2) with KI was assessed in this work, as an alternative strategy to potentiate the effect of PDT against resistant melanoma cells.
Noncovalent Helicene Structure between Nucleic Acids and Cyanuric Acid
Authors: Alenaizan Asem , Fauché Kévin , Krishnamurthy Ramanarayanan , Sherrill C. David 
Published: November 2020

AbstractCyanuric acid (CA), a triazine heterocycle, is extensively utilized for noncovalent self‐assembly. The association between poly(adenine) and CA into micron‐length fibers was a remarkable observation made by Sleiman and co‐workers, who proposed that adenine and CA adopt a hexameric rosette configuration in analogy with previously reported structures for CA assemblies. However, recent experimental observations from the Krishnamurthy group led to a reevaluation of the hexameric rosette model, wherein they have proposed a hydrogen‐bonded helicene model as an alternative. Our molecular dynamics simulations show that the hexad model is indeed unlikely and that this novel noncovalent helicene geometry, where the adenine and CA bases form an extended helical hydrogen‐bond network across the system, is a more probable structural motif. The existence of noncovalent helicene compounds may have wide‐ranging applications in DNA nanotechnology and helicene chemistry.
CompassR Yields Highly Organic‐Solvent‐Tolerant Enzymes through Recombination of Compatible Substitutions
Authors: Cui Haiyang , Jaeger Karl‐Erich , Davari Mehdi D. , Schwaneberg Ulrich 
Published: November 2020

AbstractThe CompassR (computer‐assisted recombination) rule enables, among beneficial substitutions, the identification of those that can be recombined in directed evolution. Herein, a recombination strategy is systematically investigated to minimize experimental efforts and maximize possible improvements. In total, 15 beneficial substitutions from Bacillus subtilis lipase A (BSLA), which improves resistance to the organic cosolvent 1,4‐dioxane (DOX), were studied to compare two recombination strategies, the two‐gene recombination process (2GenReP) and the in silico guided recombination process (InSiReP), employing CompassR. Remarkably, both strategies yielded a highly DOX‐resistant variant, M4 (I12R/Y49R/E65H/N98R/K122E/L124K), with up to 14.6‐fold improvement after screening of about 270 clones. M4 has a remarkably enhanced resistance in 60 % (v/v) acetone (6.0‐fold), 30 % (v/v) ethanol (2.1‐fold), and 60 % (v/v) methanol (2.4‐fold) compared with wild‐type BSLA. Molecular dynamics simulations revealed that attracting water molecules by charged surface substitutions is the main driver for increasing the DOX resistance of BSLA M4. Both strategies and obtained molecular knowledge can likely be used to improve the properties of other enzymes with a similar α/β‐hydrolase fold.
Der Schnellstart in die digitale Lehre unter Corona‐Randbedingungen
Authors: Kockmann Norbert 
Published: November 2020

AbstractDer Corona‐Lockdown und die Campus‐Schließung der TU Dortmund führten zu einem vollständig digitalen Sommersemester 2020 der Fakultät für Bio‐ und Chemieingenieurwesen. Vollständig digital? Nein! Dieser Beitrag gibt Beispiele für unterschiedliche digitale Lehrveranstaltungen. Aus der Sicht des Studiendekans werden Erfahrungen und persönliche Reflexionen zu diesem ungewöhnlichen Semester bis Juli 2020 dargestellt. Nach einer kurzen Einleitung werden Maßnahmen zur digitalen Lehre mit der schrittweisen Teilöffnung beschrieben. Insbesondere der Erfahrungsaustausch zusammen mit dem Feedback der Studierenden brachte interessante Ergebnisse und Erfahrungen mit digitalen Werkzeugen. Die daraus gezogenen Lehren werden skizziert zusammen mit Empfehlungen für verschiedene digitale Werkzeuge und einem Ausblick auf kommende Semester vorgestellt.
Local Distortions in a Prototypical Zeolite Framework Containing Double Four‐Ring Cages: The Role of Framework Composition and Organic Guests**
Authors: Fischer Michael , Freymann Linus 
Published: November 2020

AbstractCube‐like double four‐ring (d4r) cages are among the most frequent building units of zeolites and zeotypes. In materials synthesised in fluoride‐containing media, the fluoride anions are preferentially incorporated in these cages. In order to study the impact of framework composition and organic structure‐directing agents (OSDAs) on the possible occurrence of local distortions of fluoride‐containing d4r cages, density functional theory (DFT) calculations and DFT‐based molecular dynamics simulations were performed for AST‐type zeotypes, considering four different compositions (SiO2, GeO2, AlPO4, GaPO4) and two different OSDA cations (tetramethylammonium [TMA] and quinuclidinium [QNU]). All systems except SiO2‐AST show significant deformations, with a pyritohedron‐like distortion of the d4r cages occurring in GeO2‐ and GaPO4‐AST, and a displacement of the fluoride anions towards one of the corners of the cage in AlPO4‐ and GaPO4‐AST. While the distortions occur at random in TMA‐containing zeotypes, they exhibit a preferential orientation in systems that incorporate QNU cations. In addition to providing detailed understanding of the local structure of a complex host‐guest system on the picosecond timescale, this work indicates the possibility to stabilise ordered distortions through a judicious choice of the OSDA, which might enable a tuning of the material's properties.
Corridors through time: Does resource continuity impact pollinator communities, populations, and individuals?
Authors: Nicholson Charlie C. , J.‐M. Hayes Jen , Connolly Samantha , Ricketts Taylor H. 
Published: November 2020

AbstractSpatial aspects of connectivity have received considerable attention from ecologists and conservationists, yet temporal connectivity, the periodic linking of habitats, plays an equally important, but largely overlooked role. Different biological and biophysical attributes of ecosystems underpin temporal connectivity, but here we focus on resource continuity, the uninterrupted availability of foraging sites. We test the response of pollinators to resource continuity at community, population, and individual levels using a novel natural experiment consisting of farms with either single or sequential cropping systems. We found significant effects at the population level; colony density of an important crop pollinator (Bombus impatiens L.) was greater when crop floral resources were continuously available. However, we did not find significant effects at the community or individual level; wild bee abundance, diversity and body size did not respond to resource continuity. Raspberry farms with greater early season resources provided by blueberry had greater bumble bee populations, suggesting beneficial effects on resource availability due to crop diversity. Better understanding the impact of resource continuity via crop diversity on broader patterns of biodiversity is essential for the co‐management of biodiversity and ecosystem services.
Mapping features of pathological exercise using hierarchical‐dimensional modeling
Authors: Dreier Melissa J. , Coniglio Kathryn , Selby Edward A. 
Published: November 2020

AbstractObjectivePathological exercise is common among those with eating disorders and has typically been characterized as excessive, compulsive, or compensatory in nature. Little is known about how pathological exercise is associated with other eating disorder behaviors or personality traits, or whether these associations differ between men and women.MethodWe used hierarchical dimensional modeling in three samples, including college women (N = 205), women with eating psychopathology (N = 268), and college men (N = 235), to examine latent associations between pathological exercise and eating disorder psychopathology, namely compulsivity, emotion regulation, and body dissatisfaction.ResultsUsing Goldberg's (2006) “bass‐ackwards” method, we identified separate 10‐factor solutions (women) or an 11‐factor solution (men). A distinct muscle building factor arose in the three‐factor solution for men, and it also notably arose in the six‐ and eight‐factor solutions for community and college women, respectively, highlighting an important understudied motivation factor in both healthy and pathological exercise. Each solution accounted for 64.8% (college women), 51.9% (women with eating psychopathology), and 43.9% (college men) of the variance in excessive exercise, respectively.DiscussionFindings indicate that pathological exercise is associated with different psychological traits (e.g., poor emotion regulation, compulsivity) across populations, and such differences may necessitate unique treatment approaches tailored accordingly.
Evolutionary history of endangered and relict tree species Dipteronia sinensis in response to geological and climatic events in the Qinling Mountains and adjacent areas
Authors: Shahzad Khurram , Liu Mi‐Li , Zhao Yu‐He , Zhang Ting‐Ting , Liu Jian‐Ni , Li Zhong‐Hu 
Published: November 2020

AbstractGeological and climatic events are considered to profoundly affect the evolution and lineage divergence of plant species. However, the evolutionary histories of tree species that have responded to past geological and climate oscillations in central China's mountainous areas remain mostly unknown. In this study, we assessed the evolutionary history of the endangered and relict tree species Dipteronia sinensis in the Qinling Mountains (QM) and adjacent areas in East Asia based on variations in the complete chloroplast genomes (cpDNA) and reduced‐genomic scale single nucleotide polymorphisms (SNPs). Population structure and phylogenetic analysis based on the cpDNA variations suggested that D. sinensis could be divided into two intraspecific genetic lineages in the eastern and western sides of the QM (EQM and WQM, respectively) in East Asia. Molecular dating suggested that the intraspecific divergence of D. sinensis occurred approximately 39.2 million years ago during the later Paleogene. It was significantly correlated with the orogeny of the QM, where the formation of this significant geographic barrier in the region may have led to the divergence of independent lineages. Bayesian clustering and demographic analysis showed that intraspecific gene flow was restricted between the EQM and WQM lineages. Isolation‐with‐migration analysis indicated that the two genetic lineages experienced significant demographic expansions after the Pleistocene ice ages. However, the genetic admixture was determined in some populations between the two lineages by the large scale of SNP variations due to DNA incompatibility, the large significant population size, and rapid gene flow of nuclear DNA markers. Our results suggest that two different conservation and management units should be constructed for D. sinensis in the EQM and WQM areas. These findings provide novel insights into the unprecedented effects of tectonic changes and climatic oscillations on lineage divergence and plant population evolution in the QM and adjacent areas in East Asia.
Glycemic control, associated factors, acute complications of Type 1 Diabetes Mellitus in children, adolescents and young adults in Tanzania
Authors: McLarty Ronald P. , Alloyce Julius P. , Chitema Grace G. , Msuya Levina J. 
Published: November 2020

AbstractObjectiveTo determine the factors associated with poor glycemic control in children (1‐10 years), adolescents (11‐18 years) and young adults (19‐40 years) with Type 1 Diabetes Mellitus (T1DM) in Kilimanjaro Christian Medical Center (KCMC) in Moshi, Mount Meru Regional Referral Hospital (MMRRH) and Meru District Hospital (MDH) in Arusha, Tanzania.MethodsCross sectional study of 150 participants conducted from January to June 2019, data was collected by structured questionnaire and analyzed using SPSS version 23.ResultsThe mean HbA1c was 12.3 ± 2.2%, 146 had poor glycemic control (HbA1c > 7.5%). BMI, insulin regime and caretaker education were associated with poor glycemic control. There were 16 participants diagnosed in DKA and the most frequently reported complications in the prior 3 months were hyperglycemia (n = 25), DKA (n = 18) and hypoglycemia (n = 4).ConclusionsGlycemic control is still very poor particularly in adolescents. Significant associations with glycemic control were higher BMI, insulin regime and guardian education. The study revealed lower prevalence of DKA at diagnosis compared to previous studies.
Temporal trends of a vasopressin V2 receptor antagonist in heart failure using a nationwide database in Japan
Authors: Kuragaichi Takashi , Sato Yukihito 
Published: November 2020

AbstractAimsReal‐world data on the use of tolvaptan, an oral selective vasopressin 2 receptor antagonist, for patients with heart failure (HF) are not available in Western countries because tolvaptan is not indicated in the Western countries for volume overload in HF. This study aimed to investigate the current status and recent trends of tolvaptan use for HF in Japan by analysing a nationwide Japanese Diagnosis Procedure Combination database.Methods and resultsWe retrospectively identified 257 812 patients hospitalized because of HF between 1 April 2008 and 30 November 2018. The diagnosis of HF at admission was based on the International Classification of Diseases, Tenth Revision, and in‐hospital treatment. We investigated patient characteristics, in‐hospital diuretic treatment, and tolvaptan treatment after discharge. The proportion of patients who were prescribed with tolvaptan for HF increased from 3.2% in 2011 to 39% in 2018. Since 2015, tolvaptan was prescribed within 2 days of hospitalization in >50% of HF cases. At discharge of a patient who was prescribed with tolvaptan, the rate of oral loop diuretic prescription at a dose ≥80 mg decreased, while the rate of diuretic prescription at a dose <40 mg increased. After discharge, the rate of tolvaptan prescription gradually increased from 34.0% in 2011 to 69.7% in 2018; however, tolvaptan prescriptions lasting >14 days decreased after 2012.ConclusionsThis large‐scale survey indicated an increased rate of tolvaptan prescription and an early shift to tolvaptan treatment in patients with HF in Japan. The prognostic effects of this change in HF treatment remain unclear.
Demands on nonstructural components in buildings with controlled rocking braced frames
Authors: Buccella Nathan , Wiebe Lydell , Konstantinidis Dimitrios , Steele Taylor 
Published: November 2020

AbstractControlled Rocking Braced Frames (CRBFs) have been developed as a high‐performance seismic force resisting system that can self‐center after an earthquake and avoid structural damage. A CRBF is designed to uplift and rock on its foundation, and this response is controlled using prestressing and energy dissipation devices that are engaged by uplift. Although CRBFs have been shown to have desirable structural performance, a comprehensive assessment of this system must also consider the performance of nonstructural components, which have a significant impact on the safety and economic viability of the system. The purpose of this paper is to evaluate the demands on nonstructural components in buildings with CRBFs in comparison to demands in a reference codified system, taken here as a buckling restrained braced frame (BRBF), as well as to identify which design parameters influence these demands. The responses of various types of nonstructural components, including anchored components, stocky unanchored components that slide, and slender unanchored components that rock, are determined using a cascading analysis approach, where absolute floor accelerations generated from nonlinear response history analyses of each system are used as input for computing the responses of nonstructural components. The results show that the downside of maintaining elastic behavior of the CRBF members is, in general, larger demands on nonstructural components compared to the BRBF system. These demands are not highly influenced by impact during rocking or by the supplemental energy dissipation provided, as the vibration of the CRBF in its higher modes is primarily responsible for the higher demands.
Unavoidable chromatic patterns in 2‐colorings of the complete graph
Authors: Caro Yair , Hansberg Adriana , Montejano Amanda 
Published: November 2020

AbstractGiven a graph on edges, we consider the following two extremal problems: provided is large enough, what is the minimum integer , if it exists, such that any 2‐coloring of the edges of a complete graph on vertices having more than edges in each color class, contains a balanced copy of , that is, a copy of with exactly edges in one of the colors? Graphs for which this is possible are called balanceable. The second problem deals with a similar question but we seek to guarantee copies of in every tone, that is, having exactly edges in, say, color red, for every . Graphs with this property are called omnitonal. We study these problems for different graph families, including paths, stars, and trees in general. When studying such extremal parameters, the question of its existence is obliged. In this line, two universal unavoidable patterns in 2‐edge‐colorings of the complete graph with sufficient representation in each of the colors emerge naturally and they are the key to characterizing balanceable as well as omnitonal graphs. For the two universal unavoidable patterns, which were already known to exist via a Ramsey‐theoretic approach, we present here a Turán‐type counterpart.