bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reactivity of a Neutral Yttrium(III) Trimethyl Complex toward Brønsted and Lewis Acids
Authors: Mortis Alexandros , Malzacher Jonas , Maichle‐Mössmer Cäcilia , Anwander Reiner 
Published: May 2024

AbstractThe present study corroborates that the neutral tridentate N‐ligand 1,4,7‐trimethyl‐triazacyclononane (Me3TACN) qualifies as a versatile platform to study selective ligand exchange with rare‐earth‐metal alkyl complexes, herein [(Me3TACN)YMe3]. Treatment with Brønsted‐acidic bis(dimethylsilyl)amine, HN(SiHMe2)2, gave selectively the mono‐exchanged heteroleptic complex [(Me3TACN)YMe2{N(SiHMe2)2}]. Depending on the molecular ratio employed, the reaction of [(Me3TACN)YMe3] with AlMe3 resulted in the isolation/crystallization of [(Me3TACN)YMe2(AlMe4)] [1 : 1] or ion‐separated [(Me3TACN)YMe(AlMe4)][AlMe4] [1 : 2] and [(Me3TACN)YMe(AlMe4)][Al2Me7] [1 : 3]. Analogous reactions with the heavier group 13 methyls GaMe3 and InMe3 generated mixed methyl/tetramethylgallato complex [(Me3TACN)YMe2(GaMe4)] and ion‐separated [{(Me3TACN)YMe2}2{μ‐Me}][InMe4]. Finally, dimethylalane, HAlMe2, converted [(Me3TACN)YMe3] into heteroaluminate [(Me3TACN)Y(HAlMe3)3], representing an AlMe3‐supported, molecular yttrium trihydride complex. All compounds were investigated by single crystal X‐ray diffraction (SC‐XRD), homo‐ and heteronuclear (13C, 27Al, 89Y, 115In) NMR as well as IR spectroscopies and elemental analyses.
Recent Advances in Photochemical/Electrochemical Carboxylation of Olefins with CO2
Authors: Wang Qian , Wang Yanwei , Liu Min , Chu Ganghui , Qiu Youai 
Published: May 2024

Comprehensive SummaryCO2 is an abundant, nontoxic, and renewable C1 feedstock in synthetic chemistry. Direct carboxylation of readily available olefins incorporating CO2 is regarded as a promising strategy to access high value‐added carboxylic acids as well as CO2 fixation. However, due to the thermodynamic stability and kinetic inertness of CO2 and the difficulty in controlling the regioselectivity, the carboxylation of olefins with CO2 still remains challenging. Radical‐type functionalization with olefins represented a powerful protocol and enabled the development of novel transformations in this realm. More recently, the advance of new technology, such as photoredox catalysis and the renaissance of electrochemistry in organic synthesis, offered access to unique chemical reactivities of radical precursors and provided new solutions to the functionalization of olefins. This review presents the recent advances in the radical‐type carboxylation of olefins, which has mainly been achieved through photocatalysis and electrocatalysis in the last decade. In this article, we provide a comprehensive introduction of the progress, summarize the advantages and limitations of current research, and discuss the potential outlook for further development.
Key Scientists
Standard Response Calculation of Electric Dipole Polarizability and Specific Optical Rotation Power Densities
Authors: Summa Francesco F. , Monaco Guglielmo , Zanasi Riccardo 
Published: May 2024

AbstractA time‐dependent method has been developed to solve the standard response equation for the calculation of dynamic molecular property densities, endowed with the characteristic of being origin‐invariant, entirely in the atomic orbital basis at both HF and DFT level of theory. The method has been tuned in particular for the calculation of origin‐independent electric dipole polarizability density and specific rotation power density. Some demonstrations are given for the hexabenzocoronene molecule and the Tröger′s base.
Plasmon‐Mediated Organic Photoelectrochemistry Applied to Amination Reactions
Authors: Buravets Vladislav , Gorin Oleg , Burtsev Vasilii , Zabelina Anna , Zabelin Denis , Kosina Jiri , Maixner Jaroslav , Svorcik Vaclav , Kolganov Alexander A. , Pidko Evgeny A. , Lyutakov Oleksiy 
Published: May 2024

AbstractOrganic electrochemistry is currently experiencing an era of renaissance, which is closely related to the possibility of carrying out organic transformations under mild conditions, with high selectivity, high yields, and without the use of toxic solvents. Combination of organic electrochemistry with alternative approaches, such as photo‐chemistry was found to have great potential due to induced synergy effects. In this work, we propose for the first time utilization of plasmon triggering of enhanced and regio‐controlled organic chemical transformation performed in photoelectrochemical regime. The advantages of the proposed route is demonstrated in the model amination reaction with formation of C−N bond between pyrazole and substituted benzene derivatives. Amination was performed in photo‐electrochemical mode on the surface of plasmon active Au@Pt electrode with attention focused on the impact of plasmon triggering on the reaction efficiency and regio‐selectivity. The ability to enhance the reaction rate significantly and to tune products regio‐selectivity is demonstrated. We also performed density functional theory calculations to inquire about the reaction mechanism and potentially explain the plasmon contribution to electrochemical reaction rate and regioselectivity.
Enhanced Activity and Selectivity for Nitrogen Reduction Reaction in Electrides‐Based Heterostructures: A DFT Computational Study
Authors: Wijesingha Hetti , Wan Tsz Lok , Liu Junxian , Kou Liangzhi 
Published: May 2024

AbstractDeveloping sustainable and efficient catalysts for ammonia synthesis from atmospheric molecular N2 under ambient conditions presents a significant 21st‐century challenge. Two‐dimensional heterostructures, particularly single‐atom catalysts (SACs) supported on two‐dimensional materials, have emerged as a promising avenue due to their remarkable catalytic activity and selectivity. Electrides, characterized by an abundance of free electrons and high surface activity, have attracted substantial attention in this context. Through density functional theory (DFT) calculations, this study proposes electride‐graphene heterostructures (EGHS) as catalysts to effectively regulate charge distribution at the catalytic center, facilitating the optimization of catalytic performance. The EGHS model addresses challenges related to excessive adsorbate binding, mitigating electron transfer compared to electride monolayer adsorption. This novel approach utilizes heterogeneous heterostructures to finely tune the catalytic site, optimizing electron input for enhanced catalysis. Based on the optimized charge transfer for N2 activation, the Cr‐doped EGHS (Cr@EGHS) exhibits a promising performance in the nitrogen reduction reaction, leading to, a relatively low limiting potential of −0.85 V and high selectivity. The hypothesis charge transfer depend on N2 activation is further supported by modulating the distance between component layers of heterostructure. These findings contribute to design principles for 2D heterostructure catalysts and offer a reference for experimental synthesis.
Stability of carboxy‐hemoglobin during storage at different temperatures
Authors: Wachsmuth Nadine B. , Bajaa Bassem , Wachsmuth Christian , Schmidt Walter F. J. 
Published: May 2024

AbstractAccurate determination of carboxy‐hemoglobin (COHb%) is essential for the assessment of hemoglobin mass (Hbmass) by CO‐rebreathing. To analyze blood samples for a certain period of time after blood collection, it is necessary to know the stability of the COHb% during storage. The aim of the study was to determine the stability of COHb% at different storage temperatures over a period of up to 3 months. Twenty‐five milliliters of cubital venous blood was taken from five volunteers (three females and two males) before and after inhalation of 0.8/1.0 mL/kg carbon monoxide and stored at +20°C and +4°C for 6 days and at −70°C for 12 weeks. Within the first 6 days, the blood was analyzed daily, then weekly for 12 weeks. Additionally, Hbmass was determined in 13 endurance athletes immediately after blood collection and after storage for 3 days (eight cyclists) and 7 days (five swimmers) at +20°C or +4°C. COHb% before and after CO inhalation was 1.56 ± 0.48 and 5.86 ± 1.12%, respectively, and remained unchanged over 6 days, with no difference between storage at different temperatures. The standard deviation (STD) over time was between 0.07% and 0.12%. Similarly, storage at −70°C for 12 weeks did not change COHb%, whereas STD was 0.07%. Hbmass determined immediately and, after 3 or 7 days of storage, differed by 10 ± 7 g and 15 ± 11 g corresponding to a typical error of 0.8% and 1.1%. Blood storage at +20°C and +4°C for 6 days and at −70°C for 12 weeks does not affect COHb% and has, therefore, no influence on Hbmass assessment.
Reorganization of bird communities along a rainforest elevation gradient during a strong El Niño event in Papua New Guinea
Authors: Sam Katerina , Jorge Leonardo Ré , Koane Bonny , Hazell Richard J. , Shearman Philip L. , Novotny Vojtech 
Published: May 2024

AbstractThe El Niño 2015 event, most extreme since 1997, led to severe droughts in tropical wet Papua New Guinea (PNG), reducing May to October dry season rainfall by 75% in the lowlands and 25% in the highlands. Such droughts are likely to have significant effects on terrestrial ecosystems, but they have been poorly explored in Papua New Guinea. Here, we report changes in bird community composition prior to, during, and after the 2015 El Niño event along the elevational gradient ranging from 200 m to 2700 m a.s.l. at the Mt. Wilhelm rainforest in PNG. The abundance of birds in the lowlands dropped by 60% but increased by 40% at elevations above 1700 m during El Niño year. In the following year, the individual bird species reached mean population sizes similar to pre‐El Niño years but did not fully recover. Species richness roughly followed the pattern of observed abundance and quickly and fully re‐established after the event to the pre‐ El Niño values. Thus, at least some terrestrial birds seem to react quickly to the extreme droughts in lowlands and shift to less affected mountain habitats. We recorded upper elevational range limits to shifts by more than 500 m a.s.l. in 22 bird species (out of 237 recorded in total) during El Niño year, in contrast to their typical ranges. Our study suggests that a strong El Niño event can have strong but reversible effects on bird communities as long as they have an opportunity to move to more favorable sites through undisturbed habitats.
Phthalimide and 3‐Formylindole Derivatives for Oligonucleotide Conjugation by Amide or Oxime Ligation
Authors: Graidia Nessrine , Meyer Albert , Smietana Michael , Morvan François 
Published: May 2024

AbstractA phthalimide or 3‐formylindole functionality was incorporated into a tris(hydroxymethyl)ethane (THME) scaffold, and the resulting compounds were subsequently transformed into phosphoramidites and solid supports. These building blocks were then used to synthesise oligonucleotides containing amine or aldehyde groups at various positions within their sequences. The resulting modified oligonucleotides were further conjugated through either amide bond formation or oxime ligation. These novel building blocks expand the repertoire of phosphoramidites and solid supports available for modifying oligonucleotides.
Are we tackle ready? Cross‐sectional video analysis of match tackle characteristics in elite women's Rugby Union
Authors: Dane Kathryn , West Stephen W. , Hendricks Sharief , Simms Ciaran , van Dyk Nicol , Connors Will , Wilson Fiona 
Published: May 2024

AbstractThe tackle contest is the most common and most injurious match contact event in rugby and is an indicator of performance. Tackle Ready is World Rugby's tackle technique education program. Limited research has characterized the tackle contest in women's rugby. The purpose of this study is to: (1) identify the match situational characteristics, ball‐carrier and tackler technical actions demonstrated in elite women's Rugby Union and (2) to determine the extent to which Tackle Ready recommended tackle techniques were exhibited. Technical characteristics for 1500 tackle events in the 2022–2023 Women's Six Nations Championship were visually assessed according to a predefined coding framework and the Tackle Ready program. Tackles lacked full completion (0.2%) of the 22 coded Tackle Ready techniques with 47% of the recommended techniques demonstrated in each tackle on average (range 15%–98%). A high proportion of tackles involved two defenders (48%), approaching ball‐carriers from the side (38%) or oblique angles (39%), in an upright position (30%), and with initial contact made with the arm (51%). Incorrect pre‐contact head positioning and head placement upon contact accounted for 50% and 15% of tackles, respectively, and there was a mean of 14 (95% CI 11–18) head and neck contacts to a tackler and 18 (95% CI 14–22) head and neck contacts to a ball‐carrier per game. Targeted interventions to encourage adoption of recommended techniques are needed to reduce tackle‐related injury risk in women's rugby. This study provides valuable context for future discussion across law enforcement, coach education and gender‐specific tackle coaching in the women's game.
Structural and non‐structural numerical blind prediction of shaking table experimental tests on fixed‐base and base‐isolated hospitals
Authors: Mazza Fabio , Donnici Angelo , Labernarda Rodolfo 
Published: May 2024

AbstractBase‐isolated hospitals are frequently preferred to fixed‐base ones because of their improved seismic structural performance. Despite this, the question remains open on the advisability of using this modern seismic protection technology in preference to other conventional solutions, on the grounds of a holistic approach based on limiting non‐structural damage as well as continuity of service to the community in the aftermath of an earthquake. Two full‐scale four‐storey (fixed‐base) and three‐storey (base‐isolated) hospital buildings have been recently built and subjected to three‐dimensional shaking table tests at the National Research Institute for Earth Science and Disaster Prevention (Japan), with particular attention to evaluating and classifying functionality of non‐structural components and vital medical equipment. A two‐phase experimental campaign was carried out considering two earthquakes scaled at different intensity levels and applied along the horizontal and vertical directions. The current study aims to provide results of a numerical structural and non‐structural blind prediction of these hospital settings. A homemade numerical code is developed to account for lumped plasticity modelling of steel frame members and variability of the friction coefficient of spherical sliding bearings. Moreover, three non‐structural components are modelled in the fixed‐base structure: that is, elastic single degree of freedom systems representing two tanks filled with sand at the top floor; elastic beam elements for piping at the third floor; five‐element macro‐model for the in‐plane‐out‐of‐plane nonlinear response of partition walls at the first floor. The identification of predominant vibration periods of the fixed‐base structure is carried out using a homemade numerical code based on the continuous wavelet transforms in combination with the complex Morlet wavelet. Finally, the sliding and rocking motion of three items of medical equipment (i.e., incubator at third floor, dialysis machine at second floor and surgical bed at first floor) are analysed by means of a homemade numerical code, considering acceleration time histories of selected structural nodes of the fixed‐base structure.
Simplification errors in predictive models
Authors: van Veen Barbara L. , Roland Ortt J. 
Published: May 2024

AbstractOrganizational and political responses to strategic surprises such as the credit crunch in 2008 and the pandemic in 2020 are increasingly reliant on scientific insights. As a result, the accuracy of scientific models has become more critical, and models have become more complex to capture the real‐world phenomena as best as they can. So much, so that appeals for simplification are beginning to surface. But unfortunately, simplification has its issues. Too simple models are so generic that they no longer accurately describe or predict real‐world cause‐effect relationships. On the other hand, too complex models are hard to generalize. Somewhere on the continuum between too simple and too complex lies the optimal model. In this article, the authors contribute to the ongoing discussion on model complexity by presenting a logical and systematic framework of simplification issues that may occur during the conceptualization and operationalization of variables, relationships, and model contexts. The framework was developed with the help of two cases, one from foresight, a relatively young discipline, and the other from the established discipline of innovation diffusion. Both disciplines have a widely accepted foundational predictive model that could use another look. The shared errors informed the simplification framework. The framework can help social scientists to detect possible oversimplification issues in literature reviews and inform their choices for either in‐ or decreases in model complexity.
Interplay between α‐thalassemia and β‐hemoglobinopathies: Translating genotype–phenotype relationships into therapies
Authors: Vadolas Jim , Nualkaew Tiwaporn , Voon Hsiao P. J. , Vilcassim Shahla , Grigoriadis George 
Published: May 2024

Abstractα‐Thalassemia represents one of the most important genetic modulators of β‐hemoglobinopathies. During this last decade, the ongoing interest in characterizing genotype–phenotype relationships has yielded incredible insights into α‐globin gene regulation and its impact on β‐hemoglobinopathies. In this review, we provide a holistic update on α‐globin gene expression stemming from DNA to RNA to protein, as well as epigenetic mechanisms that can impact gene expression and potentially influence phenotypic outcomes. Here, we highlight defined α‐globin targeted strategies and rationalize the use of distinct molecular targets based on the restoration of balanced α/β‐like globin chain synthesis. Considering the therapies that either increase β‐globin synthesis or reactivate γ‐globin gene expression, the modulation of α‐globin chains as a disease modifier for β‐hemoglobinopathies still remains largely uncharted in clinical studies.
Maternal deaths among Brazilian indigenous women—Analysis from 2015 to 2021
Authors: Lopes Garrafa Julia , Dantas‐Silva Amanda , Garanhani Surita Fernanda , de Siqueira Guida José Paulo , Bhadra Vale Diama , de Campos Brandão Marina , Trapani Alberto , Knobel Roxana 
Published: May 2024

AbstractObjectiveThis study examines maternal mortality among Brazilian indigenous women from 2015 to 2021, contrasting their causes of death with non‐indigenous women.MethodsAn observational study utilizing Ministry of Health data analyzed maternal deaths' characteristics, comparing indigenous and non‐indigenous groups based on death certificates and live‐birth records. Variables included age, region, location, time, and cause of death. Maternal mortality ratios (MMR) were calculated with linear regression and outliers identified with Grubbs test. Prevalence ratios compared MMR and causes of death.ResultsBetween 2015 to 2021, Brazil recorded 13 023 maternal deaths. Among these, with 205 among indigenous women (1.60% of total). Indigenous women had higher MMR (115.14/100 000), than non‐ indigenous women (66.92/100 000), consistently across years. Hemorrhagic causes notably contributed to the indigenous women's elevated MMR.ConclusionIndigenous Brazilian women face elevated maternal mortality rates across all causes, primarily due to hemorrhage, contrasting wih national trends.
Climate‐driven runoff variability in semi‐mountainous reservoirs of the Vietnamese Mekong Delta: Insights for sustainable water management
Authors: Minh Huynh Vuong Thu , Kumar Pankaj , Meraj Gowhar , Van Thinh Lam , Downes Nigel K. , Van Ty Tran , Nam Nguyen Dinh Giang , Zhang Fei , Liu Bin , Hung Le Thien , Van Duy Dinh , Ly Tran Thi Truc , Luat Nguyen Quoc , Avtar Ram , Almazroui Mansour 
Published: May 2024

AbstractThe Mekong Delta, South East Asia's ‘rice bowl’, sustains more than 18 million people through its agricultural output. This yield is secured by efficient water management systems but is susceptible to climatic changes. As Vietnam's policies aim to optimize the delta's semi‐mountainous regions reliant on rain‐fed agriculture, this study investigates drought risks and climate change impacts on runoff in the O Ta Soc and O Tuk Sa reservoirs, An Giang Province, Vietnam. Using simulation models, we determined runoff volumes for specific rainfall return periods and climate scenarios for the 2030s and 2050s. Using the storm water management model (SWMM), we simulated the reservoir water balance considering rainfall, evaporation and infiltration. Our findings suggest potentially increased runoff and reservoir storage due to intensified monsoons and reduced off‐season rainfall. The 4.77 km2 drainage of the O Ta Soc reservoir could benefit from this, while the 2.55 km2 drainage of the O Tuk Sa watershed may require alternative water‐sourcing strategies. This research offers insights for drought predictions, flood management and water strategies in An Giang. To refine these predictions, future research should consider upcoming rainfall patterns.
Molecular insights into the antioxidant and anticancer properties: A comprehensive analysis through molecular modeling, docking, and dynamics studies
Authors: Banu Hamza Serina , Parvin Ismail sheriff , Priyadharshini Subramanian Deepika , Gayathiri Ekambaram , Prakash Palanisamy , Pratheep Thangaraj 
Published: May 2024

AbstractPlants are rich sources of therapeutic compounds that often lack the side effects commonly found in synthetic chemicals. Researchers have effectively synthesized pharmaceuticals from natural sources, taking inspiration from traditional medicine, in their pursuit of modern drugs. This study aims to evaluate the phenolic and flavonoid content of Solanum virginianum seeds using different solvent extracts, enzymatic assays including 2,2‐diphenyl‐1‐picrylhydrazyl activity, reducing power, and superoxide activity. Our phytochemical screening identified active compounds, such as phenols, flavonoids, tannins, and alkaloids. The methanol extract notably possesses higher levels of total phenolic and flavonoid content in comparison to the other extracts. The results highlight the superior antioxidant activity of methanol‐extracted leaves, demonstrated by their exceptional IC50 values, which surpass the established standard. In this study, molecular docking techniques were used to assess the binding affinity and to predict the binding conformation of the compounds. Quercetin 3‐O beta‐d‐galactopyranoside displayed a binding energy of −8.35 kcal/mol with several important amino acid residues, PHE222, TRP440, ILE184, LEU192, VAL221, LEU218, SER185, and ALA188. Kaempferol 3‐O‐beta‐l‐glucopyranoside exhibited a binding energy of −8.33 kcal/mol, interacting with specific amino acid residues including ALA 441, VAL318, VAL322, MET307, ILI409, GLY442, and PHE439. The results indicate that the methanol extract has a distinct composition of biologically active constituents compared to the other extracts. Overall, seeds exhibit promise as natural antioxidants and potential agents for combating cancer. This study highlights the significance of utilizing the therapeutic capabilities of natural compounds and enhancing our comprehension of their pharmacological characteristics.