bluuebunny/crossref_metadata_2025_split huggingface dataset:
The timing of visits by large and small bees differentially affects pollination success in Mimulus ringens
Authors: Mitchell Randall J. , Starvaggi Dana , Fitzgerald Victor , Karron Jeffrey D. 
Published: July 2024

AbstractPremiseCross‐fertilization in most flowering plants is facilitated by mobile animals that transport pollen while foraging for floral rewards. The contributions of different visitors can vary widely, depending on the amount of pollen transferred during a single visit and on the frequency and timing of the visits of each pollinator taxon.MethodsWe used three approaches to measure the pollination value of bees that visit Mimulus ringens: pollinator interviews, field population observations, and caging studies.ResultsThe single‐visit effectiveness of small bees (primarily Halictidae) was only half that of larger bees (primarily Bombus) for pollen delivery and removal. In five field populations, we found substantial temporal and spatial variation in visitation and pollination. In most sites big bees were active before 08:00 hours, and by 10:00–11:00 hours, stigmas were usually fully pollinated and closed, and little pollen remained in anthers. Small bees seldom visited before 10:00 hours. Excluding big bees from plants confirmed that pollination is reduced and delayed in this ecological context.ConclusionsBig bees are the primary pollinators of M. ringens, accounting for at least 75% of seed production. Not only are they more effective per visit, in most situations they also visit before small bees become active. Although small bees are not usually important pollinators of M. ringens, they have the potential to partially replace them as a “fail‐safe” pollinator in contexts where big bees are not abundant. In a world where pollinator abundance is declining, such backup pollinators may be important for maintaining plant reproduction.
Recent Advances on Synthesis of 2H‐Chromenes, and Chromenes Fused Hetrocyclic Compounds
Authors: Kumar Maurya Rohit , Dey Ashutosh , Kumara Vikash , Khatravath Mahender 
Published: July 2024

AbstractChromenes and 2H‐Chromenes are vital components of natural products, pharmaceuticals, and agrochemicals that have captured the attention of researchers worldwide. These heterocyclic compounds represent an essential class of structural scaffolds, and the quest for their synthesis in a mild and straightforward way has gained significant momentum. Chromenes are oxygen‐containing heterocycles that have been widely studied due to their potential medicinal properties. In the last two decades, researchers have made remarkable progress towards the synthesis of chromene based heterocyclic compounds using O‐propargylated benzaldehydes as a substrate. These substrates are highly versatile and contain functional groups that make them ideal for a wide range of reactions. This review article provides an in‐depth analysis of the latest advances in alkynes’ functionalization, emphasizing the substrate scope, limitations, regioselectivity control, and applications of these reactions. The review also covers a range of critical methods and strategies, including multicomponent reactions, used for the general synthesis of numerous types of chromene derivatives.
Lower Locus Coeruleus Integrity Signals Elevated Entorhinal Tau and Clinical Progression in Asymptomatic Older Individuals
Authors: Engels‐Domínguez Nina , Riphagen Joost M. , Van Egroo Maxime , Koops Elouise A. , Smegal Lindsay F. , Becker J. Alex , Prokopiou Prokopis C. , Bueichekú Elisenda , Kwong Kenneth K. , Rentz Dorene M. , Salat David H. , Sperling Reisa A. , Johnson Keith A. , Jacobs Heidi I.L. 
Published: July 2024

ObjectiveElevated entorhinal cortex (EC) tau in low beta‐amyloid individuals can predict accumulation of pathology and cognitive decline. We compared the accuracy of magnetic resonance imaging (MRI)‐derived locus coeruleus integrity, neocortical beta‐amyloid burden by positron emission tomography (PET), and hippocampal volume in identifying elevated entorhinal tau signal in asymptomatic individuals who are considered beta‐amyloid PET‐negative.MethodsWe included 188 asymptomatic individuals (70.78 ± 11.51 years, 58% female) who underwent 3T‐MRI of the locus coeruleus, Pittsburgh compound‐B (PiB), and Flortaucipir (FTP) PET. Associations between elevated EC tau and neocortical PiB, hippocampal volume, or locus coeruleus integrity were evaluated and compared using logistic regression and receiver operating characteristic analyses in the PiB− sample with a clinical dementia rating (CDR) of 0. Associations with clinical progression (CDR‐sum‐of‐boxes) over a time span of 6 years were evaluated with Cox proportional hazard models.ResultsWe identified 26 (21%) individuals with high EC FTP in the CDR = 0/PiB− sample. Locus coeruleus integrity was a significantly more sensitive and specific predictor of elevated EC FTP (area under the curve [AUC] = 85%) compared with PiB (AUC = 77%) or hippocampal volume (AUC = 76%). Based on the Youden‐index, locus coeruleus integrity obtained a sensitivity of 77% and 85% specificity. Using the resulting locus coeruleus Youden cut‐off, lower locus coeruleus integrity was associated with a two‐fold increase in clinical progression, including mild cognitive impairment.InterpretationLocus coeruleus integrity has promise as a low‐cost, non‐invasive screening instrument to detect early cortical tau deposition and associated clinical progression in asymptomatic, low beta‐amyloid individuals. ANN NEUROL 2024;96:650–661
Effect of Presodiation Additive on Structural and Interfacial Stability of Hard Carbon | P2‐Na0.66Mn0.75Ni0.2Mg0.05O2 Full Cell
Authors: Sbrascini Leonardo , Sarapulova Angelina , Gauckler Cornelius , Gehrlein Lydia , Jeschull Fabian , Akçay Tolga , Mönig Reiner , Marinaro Mario , Nobili Francesco , Dsoke Sonia 
Published: July 2024

AbstractThe compatibility between a corncob‐derived hard carbon anode and a layered oxide cathode (Na0.66Mn0.75Ni0.2Mg0.05O2), as well as the effect of presodiation via cathode additive (Na2C4O4), are investigated in a sodium‐ion full cell. Extensive physicochemical and electrochemical characterizations are performed to deeply investigate the structural and interfacial evolution of the materials in the presodiated cell, either within the single cycle or upon long‐term cycling. The use of sacrificial cathode additives is generally regarded as a method to improve full cell performance, especially when using sodium‐deficient materials. However, undesired effects upon decomposition of the sacrificial salt may arise due to the complexity of the system. In this study, it is evidenced that the presodiation changes the properties of the electrodes causing a worsening of the electrochemical performance of the cell during long‐term cycling. The surface morphology of the cathode is negatively affected by the formation of holes/cracks, while redox processes associated with structural transformations are suppressed in the voltage window of interest, with partial structural deformations occurring during activation cycles. The SEI and CEI are also affected by the formation of insulating organic species, which lead to an increased thickness and interphase resistance hampering the charge transfer kinetics of the cell.
The Combinatory Effects of Essential Oil from Lippia macrophylla on Multidrug Resistant Acinetobacter baumannii Clinical Isolates
Authors: da Silva Cirino Isis Caroline , de Santana Caroline Ferreira , Vasconcelos Rocha Igor , de Souza Larissa Isabela Oliveira , Silva Marcia Vanusa , Bressan Queiroz de Figueiredo Regina Celia , Coutinho Henrique D. M. , Leal‐Balbino Tereza Cristina 
Published: July 2024

AbstractTo assess the antibacterial effectiveness of Lippia macrophylla essential oil (LMEO) against multidrug‐resistant Acinetobacter baumannii isolates, both as a standalone treatment and in combination with conventional antibiotics. LMEO demonstrated a significant inhibitory effect on the growth of A. baumannii, with a minimum inhibitory concentration (MIC) below 500 μg/mL. Notably, LMEO was capable of reversing the antibiotic resistance of clinical isolates or reducing their MIC values when used in combination with antibiotics, showing synergistic (FICI≤0.5) or additive effects. The combination of LMEO and imipenem was particularly effective, displaying synergistic interactions for most isolates. Ultrastructural analyses supported these findings, revealing that the combination of LMEO+ceftazidime compromised the membrane integrity of the Acb35 isolate, leading to cytoplasmic leakage and increased formation of Outer Membrane Vesicles (OMVs). Taken together our results point for the use of LMEO alone or in combination as an antibacterial agent against A. baumannii. These findings offer promising avenues for utilizing LMEO as a novel antibacterial strategy against drug‐resistant infections in healthcare settings, underscoring the potential of essential oils in enhancing antibiotic efficacy.
Chrysin attenuates epithelial prostatic hyperplasia in the ventral prostate of spontaneously hypertensive rats
Authors: Santos Nathany R. L. dos , de Sousa Gessica C. , Lima Phâmella N. , Medeiros Bárbara C. M. , Manso Luana A. , Silva Cinthia R. B. , Silveira Carla C. R. da , Ghedini Paulo C. , Campos Hericles M. , Costa Matheus S. , Fernandes Isadora G. , Mendes Elizabeth P. , Taboga Sebastião R. , de Castro Carlos H. , Santos Fernanda C. A. dos , Biancardi Manoel F. 
Published: July 2024

AbstractThe aim of this study was to evaluate the effects of chrysin on the ventral prostate of spontaneously hypertensive rats (SHR). Ten‐week‐old male Wistar and SHR rats received 100 mg/kg/day of chrysin (TW and TSHR) or 200 µL/day of the dilution vehicle (CW and CSHR) for 70 days. After the treatment, the animals were euthanized and the prostates were dissected out, fixed, and processed for further morphological, immunohistochemical, and biochemical analyses. Blood was collected for serological analysis. Chrysin did not interfere with the blood pressure. Morphologically, the epithelial height increased in TW and decreased in TSHR. Stereology showed an increase in the epithelial and stromal relative frequency, and a decrease in the lumen of TW, whereas the epithelium in TSHR was reduced. Normal alveoli decreased, and hyperplastic alveoli had an increment in TW, whereas in TSHR normal alveoli increased and intense hyperplasia decreased. The secretion area was reduced in TW. Immunohistochemical analysis showed a smaller number of PCNA‐positive cells in TW. Finally, the biochemical analysis showed a reduction in malondialdehyde, carbonylated proteins, superoxide dismutase, and catalase in TW and TSHR. We concluded that the chrysin effect is dependent on the context in which this flavonoid is employed. In normal conditions, the anabolic potential of the chrysin was favored, disrupting the morphology of the prostate. However, when used in animals predisposed to develop hyperplasia, this flavonoid attenuates the hyperplastic status, improving the morphology of the gland.
Luminescent Platinum(II) Complexes with Stimuli‐Responsive Flexible Lewis Pair Ligands: Spectroscopic and Computational Studies
Authors: Tong Ka‐Ming , Toigo Jessica , Kamal Saeid , Patrick Brian O. , Wolf Michael O. 
Published: July 2024

AbstractA series of new luminescent bimetallic platinum(II) complexes with stimuli‐responsive flexible Lewis pair (FlexLP) ligands are described. The FlexLP ligands consist of a dimesitylboron Lewis acid and diphenylphosphine oxide Lewis base which are in equilibrium between the unbound open form and the Lewis adduct, controlled by the hydrogen bond donating strength of the solvent. Spectroscopic techniques and density functional theory (DFT) calculations were used to interpret the photophysics of the platinum(II) complexes. All complexes exhibit tunable absorption in the region of 300–500 nm and green to orange photoluminescence, depending on the ratio of weak (THF) to strong (MeOH) hydrogen bond donating solvent employed. Spectroscopic and computational data shows that phosphine and peripheral acetylide ligands on the platinum(II) centers have limited influence on the emission energy, indicating the emission originates from the FlexLP‐dominated fluorescence. Using time‐resolved transient absorption spectroscopy it is shown that the complexes undergo intersystem crossing (ISC) to the triplet excited state upon photoexcitation, and the ISC efficiency is affected by the peripheral acetylide ligands. The triplet excited state lifetime can also be manipulated by the state of the FlexLP ligand, with the closed form complexes having longer lifetimes than the open form complexes.
Carbonylation Reactions of a Metallapentalyne: Synthesis of Its Ester and Amide Derivatives
Authors: Zhu Yongfa , Chen Dafa , Luo Ming , Xia Haiping 
Published: July 2024

Comprehensive SummaryCarbonylation reactions are a valuable synthetic method to construct carbonyl compounds and carbonylation reactions of aryl halides stand out as a highly significant tool for generating carbonyl substituted arenes. However, the important reactions have never been realized in aromatic metallacycles. Herein, we present the first carbonylation reactions of metallaaromatics, specifically alkoxycarbonylation and aminocarbonylation reactions of an osmapentalyne. During the carbonylation process, the electronic and steric properties of nucleophiles are regarded as critical factors. The alcohols with bulky substituents (isopropanol) require more reaction time and tert‐butyl alcohol is inert in the reaction. Comparatively, amines, being stronger nucleophiles, exhibit divergent behaviors. Bulky amines undergo aminocarbonylation, whereas small amines prefer direct nucleophilic additions. Control experiments revealed that the intermediate derived from coupling of metal carbyne with CO plays a significant role in the carbonylation reaction. According to these observations, a divergent pathway for the reaction is proposed. Furthermore, the photophysical properties of these carbonyl‐functionalized osmapentalene complexes are studied, and the maximum absorption peak of compound with a carboxylic group exhibits a significant red‐shift due to the smaller HOMO‐LUMO gap. These findings contribute to expanding the reactivity of metallaaromatics and offer new opportunities for the synthesis of carbonyl‐functionalized metallacycles.
The Rivalry between Intramolecular Tetrel Bonds and Intermolecular Hydrogen Bonds in (O−Si) Chelates of N‐Silylmethylamides and ‐ureas. A Theoretical Study
Authors: Chipanina Nina N. , Shainyan Bagrat A. , Oznobikhina Larisa P. , Lazareva Nataliya F. 
Published: July 2024

AbstractThe comparison of the results of theoretical calculations of (O−Si) chelates of N‐silylmethylated amides and ureas with the axial chlorine or fluorine atom at silicon to the data of X‐ray analysis of related compounds revealed the formation of covalent O−Si tetrel bonds (TB) or noncovalent O⋅⋅⋅Si tetrel bonds (NTB). The nature of the formed tetrel bond depends on the substituents at silicon and the polarity of the medium. The competition between the intramolecular TB and intermolecular hydrogen bonds (HB) with proton donors depends on the center of basicity involved in the formation of HB, which could be either oxygen or halogen. The hydrogen bonding can result in changing the nature of the tetrel bonds from covalent to noncovalent and vice versa by varying their lengths and energies. The O−Si bond energies estimated by QTAIM analysis of N‐[(chlorodimethylsilyl)methyl]‐N‐methylacetamide and its H‐complexes vary within the range of 7.2 and 12 kcal/mol in gas and solution, respectively, and correlate with the O−Si bond lengths.
Tailoring the Oxidizing Intermediate in the Fenton Reaction, OH⋅ or FeIV=Oaq, by Modifying the pKa of the (H2O)5FeII(H2O2) Complex, and the Case of PDS – a DFT Study
Authors: Meyerstein Dan , Stanbury David M. , Kornweitz Haya 
Published: July 2024

AbstractA DFT analysis of the Fenton and Fenton‐like reactions points out that the pH effect on the nature of the oxidizing intermediate formed is due to a pKa of the peroxide when hydroperoxides are used. When S2O82− is used, the pH effect is due to the pKa of one of the water ligands of the central iron cation. The results suggest that the choice of the hydroperoxide and the ligands present affects the pH at which the transition from the formation of hydroxyl radicals to the formation of FeIV=Oaq occurs.
SBA‐15 Supported Ni‐Cu Catalysts for Hydrodeoxygenation of m‐cresol to Toluene
Authors: Deplazes Roger , Teles Camila Abreu , Ciotonea Carmen , Simon Pardis , El Rassi Elias , Dhainaut Jérémy , Marinova Maya , Canilho Nadia , Richard Frédéric , Royer Sébastien 
Published: July 2024

AbstractAmidst concerns over fossil fuel dependency and environmental sustainability, the utilization of biomass‐derived aromatic compounds emerges as a viable solution across diverse industries. In this scheme, the conversion of biomass involves pyrolysis, followed by a hydrodeoxygenation (HDO) step to reduce the oxygen content of pyrolysis oils and stabilize the end products including aromatics. In this study, we explored the properties of size controlled NiCu bimetallic catalysts supported on ordered mesoporous silica (SBA‐15) for the catalytic gas‐phase HDO of m‐cresol, a lignin model compound. We compared their performances with monometallic Ni and Cu catalysts. The prepared catalysts contained varying Ni to Cu ratios and featured an average particle size of approximately 2 nm. The catalytic tests revealed that the introduction of Cu alongside Ni enhanced the selectivity for the direct deoxygenation (DDO) pathway, yielding toluene as the primary product. Optimal performance was observed with a catalyst composition comprising 5 wt.% Ni and 5 wr.% Cu, achieving 85 % selectivity to toluene. Further increasing the Cu content improved turnover frequency (TOF) values, but reduced DDO selectivity. These findings underscore the importance of catalyst design in facilitating biomass‐derived compound transformations and offer insights into optimizing catalyst composition for more selective HDO reactions.
Subjective hearing and memory problems are associated with dementia and cognition in later life
Authors: Stevenson‐Hoare Joshua , Stocker Hannah , Trares Kira , Holleczek Bernd , Brenner Hermann 
Published: July 2024

AbstractINTRODUCTIONSubjective hearing and memory problems are detectable earlier than objective measures of sensory loss and cognitive decline, which are known to be related to an increased risk of dementia in later life.METHODSUsing a population‐representative cohort of 6006 individuals (aged 50–75) we examined whether participants who self‐reported hearing and short‐term memory issues showed greater rates of dementia within 17 years of follow‐up. A sub‐cohort was tested for audiometric threshold and cognition after 14 years.RESULTSHearing and memory problems were associated with a greater risk of dementia (hazard ratios [HRs] = 1.42 [95% confidence interval: 1.11–1.81], 1.57 [1.30–1.90]), and poorer cognition 14 years later. The risk was greatest in those reporting both problems (HR = 1.99 [1.42–2.80]). At follow‐up, the level of hearing loss was associated with lower cognitive scores.DISCUSSIONSelf‐reports of hearing and short‐term memory problems are associated with poorer cognitive performance and a greater risk of dementia. Subjective assessments may have predictive power over more than a decade.Highlights
In a sample of older adults subjective hearing and memory problems were associated with dementia risk.
Cross‐sectionally, the audiometric screening threshold was associated with cognitive test scores.
Subjective sensory and memory loss questions are easy to implement and show good predictive power.
Detection of the GH analog somatrogon in sports drug testing: Immunological approaches and LC‐HRMS/MS
Authors: Walpurgis Katja , Thomas Andreas , Sato Mitsuhiko , Okano Masato , Geyer Hans , Thevis Mario 
Published: July 2024

AbstractDue to the presumed lipolytic and anabolic properties, the misuse of human growth hormone (hGH) and its synthetic analogs in sports is prohibited both in‐ and out‐of‐competition. Within this research project, the detectability of somatrogon, a recombinant fusion glycoprotein of 22 kDa hGH and the C‐terminal peptide (CTP) of the human chorionic gonadotropin (hCG) β‐subunit, with current WADA‐approved doping control assays for hGH and hCG was investigated. For that purpose, cross‐reactivity tests and a somatrogon administration study were conducted, and only “Kit 2” of the GH isoform differential immunoassays proved applicable to the detection of somatrogon administration in serum. In urine, the immunoassay specific for total hCG yielded presumptively positive findings for several post‐administration samples, which can probably be attributed to the presence of an immunoreactive fragment of the hCG β‐subunit. As the detectability of somatrogon with these approaches was found to be limited, a highly specific detection assay (LOD: 10 ng/mL) for the drug in serum samples was developed by using affinity purification with GH receptor (GHR)‐conjugated magnetic beads, proteolytic digestion, and liquid chromatography high‐resolution tandem mass spectrometry (LC‐HRMS/MS). Following optimization, the approach was comprehensively characterized, and authentic post‐administration serum samples were successfully analyzed as proof‐of‐concept, indicating a detection window of at least 96 h. Consequently, the presented method can be employed to confirm the presence of somatrogon in serum samples, where only “Kit 2” of the currently used immunoassay kits yielded an abnormally high Rec/Pit ratio.
Evaluation of stream ordering systems in the context of topography and open‐source data
Authors: Pareta Kuldeep , Pareta Upasana 
Published: July 2024

AbstractSatellite‐derived digital elevation models (DEMs) and geographic information systems (GIS) offer effective means for both qualitative and quantitative analysis of drainage networks within watersheds. An extensive review of various stream order systems reveals their outdated nature, given advancements in digital technology and the availability of fine to coarse resolutions data. Analysis of open‐source DEMs with resolutions ranging from 12.5 to 225 m, along with topographical maps at scales of 1:50 000 and 1:250 000, was conducted across four physiographically distinct micro‐watersheds of approximately equal size (~300 km2). The steepest descent algorithm (D8) was utilized to derive raster stream networks, applying a channel initiation threshold (CIT) of 900 m2 as a criterion. It was observed that stream order numbers are influenced by map scale, leading to variability in mainstream order extraction across different DEM datasets and topographic maps. To address this issue, an innovative stream order system was proposed to ensure consistent mainstream order regardless of the spatial resolution of DEM data or map scale. Correlation analysis highlighted the importance of considering both spatial resolution and topographic variability in stream order analysis, underscoring the significance of accurate DEM data and landscape characteristics in understanding stream network dynamics. This method of classifying stream orders is recognized by scientists in geography, geology, hydrology and geomorphology for providing crucial information about the size and strength of waterways within stream networks, contributing to effective water management strategies.