bluuebunny/crossref_metadata_2025_split huggingface dataset:
Makrozyklische FKBP51‐Liganden enthüllen einen transienten Bindungsmodus mit erhöhter Selektivität
Authors: Voll Andreas M. , Meyners Christian , Taubert Martha C. , Bajaj Thomas , Heymann Tim , Merz Stephanie , Charalampidou Anna , Kolos Jürgen , Purder Patrick L. , Geiger Thomas M. , Wessig Pablo , Gassen Nils C. , Bracher Andreas , Hausch Felix 
Published: April 2021

AbstractSubtyp‐Selektivität ist oft eine Herausforderung bei der Wirkstoffentwicklung. Ein Beispiel ist das FK506‐bindende Protein 51 (FKBP51) als Wirkstoffziel. Die am weitesten fortgeschrittenen FKBP51‐Liganden der SAFit‐Klasse sind hochselektiv gegenüber FKBP52, differenzieren aber kaum gegenüber den eng verwandten Proteinen FKBP12 und FKBP12.6. Eine Makrozyklisierungsstudie ergab, dass viele dieser makrozyklischen Analoga eine unerwartete, neuartige Präferenz für FKBP51 gegenüber FKBP12 und FKBP12.6 haben. Strukturellen Studien zufolge weisen diese Makrozyklen einen neuen Bindungsmodus auf, mit einer transienten Protein‐Konformation, die für die kleinen FKBPs ungünstig ist. Mithilfe eines konformationssensitiven Assays zeigen wir, dass dieser Bindungsmodus in Lösung auftritt und charakteristisch für diese neue Verbindungsklasse ist. Die Makrozyklen sind nicht immunsuppressiv, binden FKBP51 in Zellen und blockieren die zelluläre Wirkung von FKBP51 auf IKKα. Die Ergebnisse liefern ein neues chemisches Gerüst für verbesserte FKBP51‐Liganden und die strukturelle Grundlage für eine erhöhte Selektivität.
Addukte des Stammboraphosphaketens H2BPCO und deren Insertionsreaktionen mittels Decarbonylierung
Authors: Hagspiel Stephan , Fantuzzi Felipe , Dewhurst Rian D. , Gärtner Annalena , Lindl Felix , Lamprecht Anna , Braunschweig Holger 
Published: April 2021

AbstractDie ersten Beispiele für Lewis‐Basen‐Addukte des Stammboraphosphaketens H2B‐PCO und ihre cyclischen Dimere wurden hergestellt. Eines dieser Addukte zeigt unter milden Bedingungen eine Decarbonylierung und anschließende Insertion des Phosphinidens in die B‐C‐Bindung eines Borols, was in der Bildung sehr seltener Beispiele für 1,2‐Phosphaborinine, B,P‐Isostere von Benzol, resultiert. Die starken Donoreigenschaften dieser 1,2‐Phosphaborinine wurden durch die Synthese ihrer π‐Komplexe mit Metallen der Gruppe 6 bestätigt.
Intrinsic Electrocatalytic Activity for Oxygen Evolution of Crystalline 3d‐Transition Metal Layered Double Hydroxides
Authors: Dionigi Fabio , Zhu Jing , Zeng Zhenhua , Merzdorf Thomas , Sarodnik Hannes , Gliech Manuel , Pan Lujin , Li Wei‐Xue , Greeley Jeffrey , Strasser Peter 
Published: April 2021

AbstractLayered double hydroxides (LDHs) are among the most active and studied catalysts for the oxygen evolution reaction (OER) in alkaline electrolytes. However, previous studies have generally either focused on a small number of LDHs, applied synthetic routes with limited structural control, or used non‐intrinsic activity metrics, thus hampering the construction of consistent structure–activity‐relations. Herein, by employing new individually developed synthesis strategies with atomic structural control, we obtained a broad series of crystalline α‐MA(II)MB(III) LDH and β‐MA(OH)2 electrocatalysts (MA=Ni, Co, and MB=Co, Fe, Mn). We further derived their intrinsic activity through electrochemical active surface area normalization, yielding the trend NiFe LDH > CoFe LDH > Fe‐free Co‐containing catalysts > Fe‐Co‐free Ni‐based catalysts. Our theoretical reactivity analysis revealed that these intrinsic activity trends originate from the dual‐metal‐site nature of the reaction centers, which lead to composition‐dependent synergies and diverse scaling relationships that may be used to design catalysts with improved performance.
A comparison of the effects of traditional and wet mixing processes of rubber on metal friction and wear
Authors: Han Deshang , Zhang Shoufeng , Wang Kongshuo , Pan Yi , Zhu Donglin , Wang Chuansheng , Pan Yiren 
Published: April 2021

AbstractProlonged operations of mixers cause wear of mixer rotors and chamber walls and affect the clearances between the rotors and chamber walls, which reduce the mixing effect, weaken the dispersion of the packing, and affect the quality of rubber products. In this study, the effects of traditional mixing and wet mixing on the friction and wear of the chamber, and the properties of rubber were compared by using 60 phr of a silica natural rubber formulation system. The results show that a silanization reaction occurs between silica and the silane coupling agent during the mixing process and that the reaction rate is fastest when the temperature of the mixing chamber is maintained between 145 and 155°C for 1 min during the mixing process. The products of silanization reaction are ethanol and water; the water vapor that forms at high temperatures corrodes the mixing chamber of the internal mixer and aggravates wear and tear. Due to the high dispersion of silica during wet mixing, the silanization reaction is more complete and water vapor is produced at a high temperature. Hence, the rubber compound obtained by wet mixing has more significant wear on the mixing chamber.
An eco‐friendly procedure for achieving high‐yield carrageenan from Hypnea cervicornis suitable for wet spinning
Authors: Han Jie , Han Xiao , Xue Zhixin , Wang Qianqian , Xia Yanzhi , Zhao Zhihui 
Published: April 2021

AbstractIn this study, an eco‐friendly method was proposed to prepare carrageenan suitable for spinning into fibers. The extract from Hypnea cervicornis without alkali pretreatment was directly converted into the spinning solution, and carrageenan fibers were obtained via wet spinning. The improved procedure had a higher yield (61.8% ± 1.1%) than the traditional method (36.0% ± 1.3%). The chemical structure of the carrageenan was analyzed via fourier transform infrared spectroscopy (FTIR) and carbon nuclear magnetic resonance spectroscopy (13C NMR). It was confirmed that carrageenan extracted from Hypnea cervicornis was mainly ι‐carrageenan and its structure was not changed by alkali pretreatment. The properties of the spinning solution and fibers were characterized using dynamic light scattering (DLS), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), and tensile tests. The results showed that the spinning solution prepared by the improved procedure was homogeneous and suitable for spinning, and the mechanical strength of the novel prepared carrageenan fibers was equal to the fibers spanned from traditional carrageenan.
Effects of freezing and short‐term fixation on muscle mass, volume, and density
Authors: Leonard Kaitlyn C. , Worden Nikole , Boettcher Marissa L. , Dickinson Edwin , Hartstone‐Rose Adam 
Published: April 2021

AbstractPreventing postmortem deterioration of soft‐tissues is an important requisite of anatomical research. In order to provide corrections for potential myological distortions, this study quantifies the acute effects of freezing, formalin fixation and ethanol storage using muscles from (n = 46) rabbits (Oryctolagus cuniculus). Bilateral dissections of specific muscles were performed and each side was assigned to a different preparation group (fresh, formalin fixation only, fixation followed by short duration ethanol storage, and freezing once or twice). We demonstrate that short‐term freezing at −20C and thawing have no significant effect on muscle mass, volume, and density while short‐term formalin fixation and ethanol storage significantly reduces mass and volume (density remains relatively constant.) Although freezing may have less of an effect on the gross morphometric characteristics of the musculature than ethanol storage, slow freezing damages muscle microanatomy, and therefore, faster freezing and other modes of preservation such as formalin fixation and ethanol storage may be preferable. Based on our results, we derived the following correction factors for each preparation: the mass of specimens stored in 70% ethanol should be multiplied by 1.69 to approximate fresh muscle mass, and specimens fixed in 10% formalin multiplied by 1.32. Although not significant, specimens frozen‐once were slightly less massive and could be multiplied by 1.03 (frozen‐twice ×1.09). The volumetric corrections are: ethanol 1.64; 10% formalin 1.32; frozen‐once 1.03; frozen‐twice 1.10. While the density of ethanol preserved specimens is slightly less than that of fresh ones (correction: 1.03), those preserved in formalin and frozen maintain nearly the same density.
Nonserious Infections in Patients With Rheumatoid Arthritis: Results From the British Society for Rheumatology Biologics Register for Rheumatoid Arthritis
Authors: Bechman Katie , Halai Kapil , Yates Mark , Norton Sam , Cope Andrew P. ,   the British Society for Rheumatology Biologics Register for Rheumatoid Arthritis Contributors Group, Hyrich Kimme L. , Galloway James B. 
Published: April 2021

ObjectiveTo describe the frequency and predictors of nonserious infections (NSI) and compare incidence across biologic agents within the British Society for Rheumatology Biologics Register for Rheumatoid Arthritis (BSRBR‐RA).MethodsThe BSRBR‐RA is a prospective observational cohort study. An NSI was defined as an infection that did not require hospitalization or intravenous therapy. Infections were captured from clinician questionnaires and patient diaries. Individuals were considered “at risk” from the date of initiation of biologic treatment for up to 3 years. Drug exposure was defined by agent: tumor necrosis factor inhibitor (TNFi), interleukin‐6 (IL‐6) inhibitor, B cell depletion (rituximab), or conventional synthetic disease‐modifying antirheumatic drugs (csDMARDs) alone. A multiple‐failure Cox model was used with multivariable adjustment. Missing data were addressed using multiple imputation.ResultsThere were 17,304 NSI in 8,145 patients, with an event rate of 27.0 per person per year (95% confidence interval [95% CI] 26.6–27.4). Increasing age, female sex, comorbidity burden, glucocorticoid therapy, higher Disease Activity Score in 28 joints, and higher Health Assessment Questionnaire disability index were associated with an increased risk of NSI. There was a significant reduction in NSI risk with csDMARDs compared to biologic treatments. Compared to TNFi, IL‐6 inhibition and rituximab were associated with a higher NSI risk (adjusted hazard ratio 1.45 [95% CI 1.29–1.63] and adjusted hazard ratio 1.28 [95% CI 1.14–1.45], respectively), while the csDMARD cohort had a lower risk (adjusted hazard ratio 0.64 [95% CI 0.59–0.70]). Within the TNFi class, adalimumab was associated with a higher NSI risk than etanercept (adjusted hazard ratio 1.11 [95% CI 1.05–1.17]).ConclusionNSI occur frequently in RA, and predictors mirror those reported with serious infections. All biologics are associated with a greater risk of NSI, with differences observed between agents. While unmeasured confounding must be considered, the magnitude of effect is large, and a relationship between NSI and targeted immunomodulatory therapy likely exists.
Azine Steric Hindrances Switch Halogen Bonding to N‐Arylation upon Interplay with σ‐Hole Donating Haloarenenitriles
Authors: Baykov Sergey V. , Geyl Kirill K. , Ivanov Daniil M. , Gomila Rosa M. , Frontera Antonio , Kukushkin Vadim Y. 
Published: April 2021

AbstractAn interplay between 4‐bromo‐ and 4‐iodo‐5‐nitrophthalonitriles (XNPN, X=Br or I) and any one of the azines (pyridine 1, 4‐dimethylaminopyridine 2, isoquinoline 3, 4‐cyanopyridine 4, 2‐methylpyridine 5, 2‐aminopyridine 6, quinoline 7, 1‐methylisoquinoline 8, and 2,2’‐bipyridine 9) proceeds differently depending on steric and electronic effects of the heterocycles. Sterically unhindered azines 1–3 underwent N‐arylation to give the corresponding azinium salts (characterized by 1H and 13C{H} NMR and high‐resolution ESI‐MS). In contrast, azines 4–9 with sterically hindered N atoms or bearing an electron‐withdrawing substituent, form stable co‐crystals with XNPN, where two interacting molecules are bound by halogen bonding. In all obtained co‐crystals, X⋅⋅⋅N structure‐directed halogen bonds were recognized and theoretically evaluated including DFT calculations (PBE0‐D3/def2‐TZVP level of theory), QTAIM analysis, molecular electrostatic potential surfaces, and noncovalent interaction plot index. Estimated energies of halogen bonding vary from −7.6 kcal/mol (for 6 ⋅ INPN) to −11.4 kcal/mol (5 ⋅ INPN).
Electrochemical Characterization of Battery Materials in 2‐Electrode Half‐Cell Configuration: A Balancing Act Between Simplicity and Pitfalls
Authors: Heubner Christian , Maletti Sebastian , Lohrberg Oliver , Lein Tobias , Liebmann Tobias , Nickol Alexander , Schneider Michael , Michaelis Alexander 
Published: April 2021

AbstractThe development of advanced battery materials requires fundamental research studies, particularly in terms of electrochemical performance. Most investigations on novel materials for Li‐ or Na‐ion batteries are carried out in 2‐electrode half‐cells (2‐EHC) using Li‐ or Na‐metal as the negative electrode. Although such cells are easy to assemble and generally provide sufficient stability, scientists should be aware of any effects that may influence the measurements, and care should be taken when interpreting the corresponding results. The present work addresses specific effects that can affect the electrochemical response of measurements in 2‐EHC. Critical points to be considered for long‐term cycling tests and impedance analyses are discussed and illustrated with relevant examples. The different behavior of electrochemically deposited and pristine alkali metal electrodes is shown, deriving the corresponding impact on the characterization of the actual material of interest. We demonstrate possible impacts of anode‐cathode crosstalk effects on the evaluation of measurements in 2‐EHC and highlight challenges and pitfalls in the interpretation of measurements in 2‐EHC with respect to kinetic and thermodynamic properties and battery performance. These findings contribute to the understanding of the limitations of electrochemical characterization in 2‐EHCs and should be carefully considered by researchers when evaluating novel battery materials.
The first spectrofluorimetric approach for quantification of colistin sulfate and its prodrug colistimethate sodium in pharmaceutical dosage form and human plasma
Authors: Badr El‐Din Khalid M. , Abdelmajed Mahmoud A. , Omar Mahmoud A. , Attia Tamer Z. 
Published: April 2021

AbstractA new, accurate, nonextractive, and sensitive fluorimetric approach was proposed and validated for the first time estimation of colistin sulfate and its inactive prodrug colistimethate sodium in its bulk form, pharmaceutical formulations, and human plasma. The approach relied on condensation between acetylacetone/formaldehyde and the primary amino moiety of nonfluorescent colistin in Teorell and Stenhagen buffer (pH 2.8) by the Hantzsch reaction to form a highly fluorescent dihydropyridine derivative. The fluorescent product was measured at 460 nm (λex = 402 nm). A plot of relative fluorescence intensity (RFI) versus concentration was rectilinear over the range 200–4000 ng ml−1 with excellent correlation (r) and determination (r2) coefficients of 0.9999 and 0.9998, respectively. The limit of detection (LOD) and limit of quantitation (LOQ) were 40.91 and 123.99 ng ml−1, respectively. The present procedure was useful for determination of colistin sulfate either in powder form for suspension or in its parenteral prodrug colistimethate sodium in vial formulation. The investigated approach was applied for in vitro quantification of this drug in spiked human plasma, with a per cent mean recovery of 98.24 ± 1.34. The proposed method is reliable, selective, and does not require tedious sample pretreatment steps, expensive instrumentation, or harmful reagents, all of which make it ideally suited for use in quality control laboratories.
Determination of the optimal distillation sequence of a ternary mixture incorporating heat integration by means of Microsoft Excel Solver
Authors: Vázquez Ana , Briones Laura , Morales Victoria , Iglesias José , Morales Gabriel , Escola José M. 
Published: April 2021

AbstractNowadays, the computer skills acquisition by Chemical Engineering (ChE) students is based on practical uses of specialized software packages in different applications. Process optimization courses use high‐level algebraic programming languages, such as GAMS (General Algebraic Modeling System) or AMPL (A Mathematical Programming Language), which are usually reserved for advanced programs in ChE degrees or ChE M.Eng. Commercial software for process optimization has several benefits, such as the possibility of facing complex numerical problems in a more efficient and straightforward way. By contrast, they typically present expensive license fees, and students usually require intense training to get the proper user‐level skills. The use of simpler and economic software tools may help overcoming these limitations. In this context, Microsoft (MS) Excel Solver tool is a widespread software with the potential to be used worldwide by any ChE student, and with the power to solve complex optimization problems at the academic level. In this paper, we introduce the application of MS Excel Solver for the optimization of a distillation sequence for the separation of a ternary mixture, including the heat integration in the definition of the problem. This is an MINLP problem, which usually requires specialized software performing stochastic methods, such as Simulated Annealing, to achieve a solution. In this regard, the approach to solve an optimization problem using the MS Excel Solver tool shown in this study was successfully employed by a student of ChE M.Eng. at Rey Juan Carlos University and the Autónoma University of Madrid in the development of her master thesis.
Exploring the experiences of young people completing the YP‐CORE to capture clinical need on a digital counselling platform
Authors: Mindel Charlotte , Oppong Crystal , Jacob Jenna 
Published: April 2021

AbstractBackgroundAssessing clinical mental health needs through standardised mental health assessment measures is commonplace within young people's mental health services. To date, any investigation into the use of such measures within online services has been limited.AimsThe aim of this research is to contribute to the knowledge base of young people's motivation to complete voluntary standardised mental health assessment measures and how the accuracy of the information derived may be improved.MethodsParticipatory action research was utilised to conduct semi‐structured interviews with young people (N = 6). Questions were developed using the frameworks of the Theory of Planned Behaviour and Self‐Determination Theory. The data were analysed using thematic analysis, to develop global themes in response to the research aims.FindingsGlobal themes identified (N = 6) from six interviews referring to the areas of motivation and experience include “Drivers,” “Behavioural Preferences,” “Outcomes of Being Honest,” “Discomfort,” “Internal harmony” and “Self‐sabotaging beliefs.”ConclusionsThe findings from this small‐scale research demonstrate the need for transparency online, to instil trust in those completing standardised mental health assessment measures. This may be implemented through co‐designed visual materials which contribute to the young people's understanding of how the data collected through assessment will be used and what the response of the service will be following assessment.
Comply with latest protections against discrimination based on sexual orientation, gender identity
Authors: Patterson Jollee Faber , Burris Erin 
Published: April 2021

Institutions of higher education should pay close attention to recent events increasing protections for LGBTQ+ individuals, as both the U.S. Supreme Court and President Joe Biden have taken significant action on this front, and more changes are likely on the horizon. Just last year, the U.S. Supreme Court expanded employment protections under Title VII to prohibit discrimination on the basis of gender identity and sexual orientation. And on the first day of his presidency, President Biden issued an executive order announcing that those same protections will apply under his administration's enforcement of Title IX. In February 2021, the U.S. House of Representatives passed the Equality Act, which would amend the Civil Rights Act to include protections against discrimination based on sexual orientation and gender identity in employment, housing, public accommodations, and other services. Although the Equality Act will still need to pass in the Senate, it's clear there are growing legal protections for LGBTQ+ individuals, and education institutions must act accordingly.
Se(IV) Immobilization onto Natural Siderite: Implications for High‐Level Nuclear Waste Repositories
Authors: Pavón Sandra , Martínez Maria , Giménez Javier , de Pablo Joan 
Published: April 2021

AbstractSorption processes of metals and semimetals on siderite are studied because of its potential adequacy for removing contaminants from natural waters and its wide availability, as well as its capacity to reduce the oxidation state of some contaminants such as selenium. In this work, it has been demonstrated that siderite reduces selenite ions in solution, showing a higher selenium immobilization capacity compared to other iron(III) minerals, which is probably due to both sorption and reduction processes.
Pd/TiO2 Coated in a Microscale‐Based Reactor by Electrophoretic Deposition for Biohydrogenated Diesel Production
Authors: Sa-ngasaeng Yanika , Sirimungkalakul Nichaporn , Boonyongmaneerat Yuttanant , Jongpatiwut Siriporn 
Published: April 2021

AbstractElectrophoretic deposition (EPD) was applied for the coating of a Pd/TiO2 catalyst for the production of biohydrogenated diesel (BHD) in a microscale‐based reactor. The coating of TiO2 using EPD was investigated under various operating conditions. The Pd/TiO2 catalysts prepared by EPD were compared with the samples obtained by the conventional washcoating (WC) technique. The optimum EPD condition giving a high degree of adhesion was determined, using Tiron and Pluronic F127 as the additives. The coated catalysts were tested for their catalytic activity. By comparing with Pd/TiO2(WC), Pd/TiO2(EPD) catalysts exhibited a higher catalytic performance which could be explained by their uniformity, high amount of Ti3+ species, and oxygen vacancies.
Improving the Cβ Stereoselectivity of l‐Threonine Aldolase for the Synthesis of l‐threo‐4‐Methylsulfonylphenylserine by Modulating the Substrate‐Binding Pocket To Control the Orientation of the Substrate Entrance
Authors: Wang Lichao , Xu Lian , Su Bingmei , Lin Wei , Xu Xinqi , Lin Juan 
Published: April 2021

Abstractl‐Threonine aldolase from Actinocorallia herbida (AhLTA) is an ideal catalyst for producing l‐threo‐4‐methylsulfonylphenylserine [(2S,3R)‐1 b], a key chiral precursor for florfenicol and thiamphenicol. The moderate Cβ stereoselectivity is the main obstacle to the industrial application of AhLTA. To address this issue, a combinatorial active‐site saturation test (CAST) together with sequence conservatism analysis was applied to engineer the AhLTA toward improved Cβ stereoselectivity. The optical mutant Y314R could asymmetrically synthesize l‐threo‐4‐methylsulfonylphenylserine with 81 % diastereomeric excess (de), which is 23 % higher than wild‐type AhLTA. Molecular dynamic (MD) simulations revealed that the mechanism for the improvement in Cβ stereoselectivity of Y314R is due to the acylamino group of residues Arg314 controlling the orientation of substrate 4‐methylsulfonyl benzaldehyde (1 a) in the active pocket by directed interaction with the methylsulfonyl group; this leads to asymmetric synthesis of l‐threo‐4‐methylsulfonylphenylserine. The success in this study demonstrates that direct control of substrates in an active pocket is an attract strategy to address the Cβ stereoselectivity problem of LTA and contribute to the industrial application of LTA.