bluuebunny/crossref_metadata_2025_split huggingface dataset:
Light‐Activated Reactivity of Nitrones with Amino Acids and Proteins
Authors: Skakuj Kacper , Iglhaut Maximilian , Shao Qian , Garcia Francisco J. , Huang Bo‐Yang , Brittain Scott M. , Nesvizhskii Alexey I. , Schirle Markus , Nomura Daniel K. , Toste F. Dean 
Published: November 2024

AbstractControlled modifications of amino acids are an indispensable tool for advancing fundamental and translational research based on peptides and proteins. Yet, we still lack methods to chemically modify each naturally occurring amino acid sidechain. To help address this gap, we show that N,α‐diaryl oxaziridines expand the scope of bioconjugation methods to chemically modify cysteine, methionine, and tryptophan residues with evidence for additional tyrosine labelling in a proteomic context. Conjugation primarily at tryptophan sites can be accessed by selective cleavage of modifications at other sidechains. The N,α‐diaryl oxaziridine reagents are accessed through photoisomerization of nitrones, which serve as photocaged reagents, thus providing an additional level of control over reactivity. Initial guiding principles for the design of nitrone reagents are developed by exploring the impact of structure on UV/Vis absorption, photoisomerization, and reactivity. We identify a nitrone structure that maximizes photoisomerization efficiency, the aqueous stability of the oxaziridine, the extent of amino acid modification, and the stability of the resulting amino acid conjugates. We then translate nitrone reagents to modify proteins in aqueous conditions. Finally, we use nitrones to profile reactive residues across the proteome of a mammalian cell line and find that they expand the proteome coverage.
A Photochemical Strategy towards Michael Addition Reactions of Cyclopropenes
Authors: Hussain Yaseen , R. Prasanna , Empel Claire , Sharma Deepak , Kloene Lennard , Zhu W. Felix , Kaiser Astrid , Weizel Lilia , Proschak Ewgenij , Koenigs Rene M. , Chauhan Pankaj 
Published: November 2024

AbstractThe development of Michael addition reactions to conjugated cyclopropenes is a challenge in organic synthesis due to the fleeting and reactive nature of such strained Michael acceptor systems. Herein, the development of a photochemical approach towards such conjugated cyclopropenes is reported that serves as a strategic entry point to densely functionalized cyclopropanes in a diastereoselective fashion. The process involves the light‐mediated generation of transient cyclopropenyl α,β‐unsaturated esters from vinyl diazo esters, followed by an organic base catalyzed nucleophilic addition of N‐heterocycles to directly access β‐N‐heterocyclic cyclopropanoic esters. With this synergistic approach, various trisubstituted cyclopropanes bearing N‐heteroaryl and N‐heterocyclic rings such as indole, pyrrole, benzimidazole, isatin, pyridinone, and quinolinone were accessed efficiently in good yield and decent to good diastereoselectivities. Further, β‐indolyl cyclopropanoic acids have been synthesized and were successfully evaluated as FABP‐4 inhibitors. Theoretical calculations have been performed to elucidate the mechanism, which was further supported by experimental findings.
Effect of peer facilitation in anatomy small group curriculum on academic performance and retention: A pilot study
Authors: Li Phoebe L. , Asri Rijul , Holan George , Traba Christin , Chen Sophia , Grachan Jeremy J. 
Published: November 2024

AbstractPeer‐assisted learning and group facilitation have been proven to foster active participation in small‐group learning, and these effective teaching modalities have been shown to enhance learning outcomes. This study introduced a student peer facilitator role in an anatomy small‐group curriculum for pre‐clerkship medical students and explored its impact on academic performance and retention. Students were required to rotate through this facilitator role and lead their small group during their designated sessions. Data collection methods included pre‐course and post‐course surveys, individual quiz grades, and retention quizzes sent 1 month after each quiz. Overall, the data revealed a significant increase in the overall combined quiz averages across the curriculum for facilitators compared to participants despite having no notable increase in preparation time (p = 0.004). While facilitators scored significantly higher on the course quizzes, the slight increase in their average retention quiz scores was not significant. This study was unable to identify any significant benefits to retention for either facilitators or participants. In all, this study suggests that a peer facilitation paradigm can be an effective educational modality for medical students, and future studies should explore ways to improve knowledge retention through this role.
Controllability of switched oscillatory systems and its applications to multiagent systems
Authors: Long Hao , Si Yuanchao 
Published: November 2024

AbstractIn this paper, we consider the controllability and minimum energy control problem of the switched oscillatory system. Firstly, we present the solution of the system by constructing some new nested matrix functions and establish the Gramian‐type and Kalman‐type criteria for the controllability of the system. Secondly, we derive another controllability criterion based on controllable subspace of the system. Thirdly, the optimal control to minimize the quadratic performance index of the system is presented. Lastly, the theories that we establish are applied to the controllability problem of the second‐order multiagent systems under consensus protocol and switching topologies.
Dual “Turn‐On” Fluorescent and Colorimetric Sensing of Permanganate Based on Yellow Carbon Dots
Authors: Zeng Hui‐Hui , Huang Ren‐Xiu , Qiu Yue , Duan Ju‐Lian , Jiang Shu‐Cheng 
Published: November 2024

ABSTRACTExisting permanganates (MnO4−) sensing methods suffered from the poor selectivity, restricted solubility, and/or less desirable signaling mechanisms (e.g., “turn‐off” processes), resulting in the false positive result. In this work, an effective “turn‐on” fluorescence method for MnO4− detection in aqueous media was proposed via yellow fluorescence carbon dots (Y‐CDs) with the maximum emission peak of 553 nm. Upon the introduction of MnO4−, the fluorescence of Y‐CDs increased significantly due to the enhanced surface passivation degree and intramolecular charge transfer. In the range of 0.1–10 μM, the fluorescence ratio (F/F0) is proportional to the MnO4− ions concentration, realizing the “turn‐on” fluorescence sensing of MnO4−. On the other hand, utilizing the significant color change of Y‐CDs by MnO4− ions, the colorimetric analysis can also be established for MnO4− assay. Compared with other probes, the analysis results obtained by bimodal sensing tactics of fluorescent and colorimetric can be mutually verified to improve the reliability and meet the sensing needs of targets in complex environments.
Supercritical fluid chromatography for milligram preparation of enantiomers
Authors: Knavs Naomi , Ghinet Alina , Lipka Emmanuelle 
Published: November 2024

AbstractPreparative chromatographic enantioseparation is now the preferred technique for obtaining milligram quantities of pure enantiomers in the initial phase of development of a therapeutic compound. Supercritical fluid chromatography offers several advantages over liquid chromatography and was therefore selected for the preparative enantioseparation of a new potential anti‐inflammatory molecule. Approximately 10 mg of each of the two enantiomers was successfully prepared using a Chiralpak AD‐H (tris‐3,5‐dimethylphenylcarbamate of amylose) polysaccharide‐based stationary phase with 40% of ethanol as a co‐solvent, using a stacked injection mode. A peak distortion was observed during volume overloading, which may be due to the mixed‐stream injection method.
Review of 3D‐Printed Titanium‐Based Implants: Materials and Post‐Processing
Authors: Li Yasi , Wang Fengtao 
Published: November 2024

AbstractImplants are essential in medical treatments, as they offer restored function, quality of life enhancement, and long‐term solutions. The global demand for implants is increasing due to the aging population, medical innovation, and improved medical payment capacity. 3D printing, also known as additive manufacturing, has revolutionized the fabrication of implants due to its ability to produce complex geometries and customizable designs. The superior biocompatibility, corrosion resistance, and mechanical properties of titanium (Ti) and its alloys make them ideal and common for orthopedic and dental implants. Materials are the basis of 3D‐printed implants. Ti‐based materials for 3D printing are summarized, including commercial pure titanium, binary Ti alloys, ternary Ti alloys, quaternary Ti alloys, and multicomponent Ti alloys. Post‐processing is necessary to ensure the desired performance of 3D‐printed implants. Post‐processing methods for 3D‐printed implants are reviewed from the perspective of improving the performance of the mechanical property, osseointegrative property, antibacterial property, and multiple properties. In this review, the published literatures related to the materials and post‐processing of 3D‐printed Ti‐based implants are collected and discussed. The current challenges and future trends are also analyzed. It is expected to provide a basis for the application of 3D‐printed Ti‐based implants.
A Review of the Experimental Analysis of Gas–Solid Cyclone Separators
Authors: Bayareh Morteza 
Published: November 2024

AbstractGas–solid cyclones are broadly employed in the industrial sector. Even though numerical methods are currently a strong tool for predicting the characteristics of flow patterns inside cyclone separators, they should be validated using experimental data. On the other hand, several practical aspects must be considered to analyze the operating circumstances of cyclones and their design optimization. This paper summarizes cyclone working principles and measurement techniques utilized in experimental analysis. Besides, experimental aspects, including various geometries, surface roughness, erosion rate, external electric field, particle properties, etc., are discussed. Eventually, research gaps and future directions are introduced.
New approach of recycling vanadium‐bearing slags as a binder in high‐alumina refractory castables application
Authors: Derensy Mathilda , Zanin Thomas , Bleck Jan‐Felix , Tonnesen Thorsten , Gonzalez‐Julian Jesus 
Published: November 2024

AbstractHandling the massive quantities of by‐products from metallurgical processes has become a major concern in recent decades. Efforts to develop sustainable alternatives for these secondary resources are ongoing to achieve the transition to climate neutrality. This study has investigated the potential of employing vanadium‐bearing slag as a new value‐added binder in refractories, aiming to replace virgin raw materials. Two types of vanadium‐bearing slags from BOF, each containing <2 wt.% vanadium were studied. Low‐cement vanadium slag‐based castables were prepared by gradually substituting 0, 2.5, and 5 wt.% of the commercial calcium aluminate cements (Secar71 and CMA72) by the slags. The flow values of the mixes containing 5 wt.% of slag decrease significantly from about 90% to 30% after 30 min, showing poor ability to flow and thus are not considered as self‐flow castables. Castables containing 2.5 wt.% of slag present a cold crushing strength value, in the range of 71–116 MPa while values for castables containing 5 wt.% of slag fall into the range of 53–68 MPa due to the lower packing properties leading to higher porosity and reduce in strength. Similar observation was concluded for cold modulus of rupture. The micrographs of the samples containing both slag and cement show promising compatibility between the binder and aggregates after sintering at 1500°C. Overall, characteristics obtained with the samples containing slag show promising alternatives as a refractory lining.
Developing an On‐Resin Synthesis of α‐Galactosylceramide‐Peptide Conjugate Vaccines
Authors: Meijlink Michael A. , Chan Susanna T. S. , Farrand Kathryn J. , Draper Sarah L. , Burn Oliva K. , Seifert‐Simpson Jasmine M. , Mason Ngarangi C. , Connor Lisa M. , Hermans Ian F. , Painter Gavin F. , Compton Benjamin J. 
Published: November 2024

AbstractThe covalent attachment of peptide antigens to the NKT cell agonist, α‐galactosylceramide (αGalCer), generates self‐adjuvanting vaccines that prevent and/or eliminate disease in animal models of cancer and infectious disease. To date, the manufacture of these glycolipid‐peptide (GLP) conjugate vaccines utilises an automated solid‐phase process to produce the peptide followed by a manual ‘wet chemistry’ conjugation step. To expedite GLP vaccine manufacture, we sought to develop methodology that enables the attachment of resin‐bound peptide antigen to αGalCer via an amide bond thereby avoiding the need to carry out a separate chemoselective conjugation step. To facilitate this approach, novel analogues of αGalCer incorporating an activated ester spaced by an acid‐resistant, protease‐sensitive linker from either the 6′′‐position or the N‐acyl lipid were synthesised. Reacting these with resin‐bound peptide afforded the conjugate vaccines in good to excellent yields and purity. In vivo testing showed that vaccines incorporating peptide antigen attached via the galactosyl head group induced strong antigen specific CD8+ T cell responses compared to those with antigen attached via the lipid tail and control vaccine manufactured in a stepwise manner.
Mechanism of Substrate Activation by Tryptophan Hydroxylase: A Computational Study
Authors: Mokkawes Thirakorn , de Visser Sam P. 
Published: November 2024

AbstractSerotonin is a hormone that is responsible for mood regultion in the brain; however, details on its biosynthetic mechanism remain controversial. Tryptophan hydroxylase catalyzes the first step in the serotonin biosynthesis in the human body, where it regio‐ and stereoselectively hydroxylates a free tryptophan (Trp) amino acid at the C5‐position. In this work, we present a computational study ranging from molecular dynamics (MD) to quantum mechanics (QM) methods, focused on the mechanism of tryptophan hydroxylase. An MD simulation on an enzyme structure with the substrate, co‐substrate and dioxygen bound reveals a tightly bound conformation of substrate and co‐substrate, while the protein's three‐dimensional structure stays virtually intact during the simulation. Subsequently, large active‐site cluster models containing more than 200 atoms were created, and oxygen atom transfer reactions were studied. The calculations predict that the co‐factor tetrahydrobiopterin binds covalently to the iron center and react with a dioxygen molecule to form an iron(IV)‐oxo species and pterin‐4a‐carbinolamine in a stepwise manner with small energy barriers (<5 kcal mol−1) along an exergonic pathway. However, the rate‐determining step, is Trp activation through a C−O activation transition state, followed by a rapid proton relay to produce 5‐hydroxy‐L‐Trp.
The Divergent Reactivity of Acid Chlorides Under Transition Metal Catalysis
Authors: Denton Elliott H. , Stepanović Olivera , Morandi Bill 
Published: November 2024

AbstractThe power and ability of catalysis to build multiple C−C bonds in a single step has had a transformative impact on organic synthesis. While the reactivity of organohalides with metal catalysts is widely appreciated, the related and more intricate reactivity of acid chlorides is less so, despite their use as common reagents in synthesis. Here, we review the transformations of acid chlorides in combination with unsaturated C−C bonds catalyzed by palladium, rhodium, or iridium and provide an outlook for future research opportunities.
Development of Small Molecular Hyper‐activators of Human Caseinolytic Peptidase P (hClpP) with a [1,8]‐naphthyridinone Scaffold as Novel Anti‐cancer Agents
Authors: Fu Yuantao , Yuan Yinan , Tan Rongliang , Jiang Jinxin , Li Zhilong , Li Tong , Xie Guangjun , Xiao Yibei , Sun Haiying 
Published: November 2024

AbstractBased on a clinical staged small molecular hClpP activator ONC201, a class of novel hClpP agonists with a [1,8]naphthyridinone scaffold was designed, synthesized and evaluated in a series of biochemical and biological assays. Mechanism studies for the representative compound F20 indicated that it can potently bind to and activate hClpP, efficiently promote the degradation of hClpP substrates, robustly induce ATF4/CHOP regulated integrated stress responses, strongly inhibit cell growth and effectively induce apoptosis in a subset of cancer cell lines. F20 showed good PK profiles when dosed by intravenous injection and exhibited moderate oral bioavailability in mice.
Correcting images for individual differences in color appearance
Authors: Simoncelli Camilla , Webster Michael A. 
Published: November 2024

AbstractIndividual differences are a prominent feature of normal color vision and range from variations in sensitivity to perception and color naming. Corrections for differences in spectral sensitivity are common, and there is growing interest in calibrating displays for the sensitivity of an individual observer. In contrast, few studies have explored calibrations for aspects of color appearance. We developed a technique for adjusting images based directly on an individual's hue percepts and illustrate the principle of the approach using a set of hue scaling functions measured previously for a large sample of color‐normal observers (Emery et al. PNAS 2023). Colors in an image are mapped onto the average scaling function to define the hue perceived by the average “standard observer.” This hue is then mapped back to the chromaticity that would elicit the same response in any individual observer. With this correction, different observers – each looking at physically different images calibrated for their own hue percepts – should in principle agree on the perceived colors. Adjustments of this kind could be easily implemented on standard displays, because they require only measures of hue percepts and not spectral sensitivity, and could lead to greater consistency in the perception and communication about color across individuals with potentially widely different perceptual experiences of color.
Enhanced Performance of Lithium‐Sulfur Batteries Using Construction Wastes: A Sustainable Approach to High‐Loading Sulfur Cathodes
Authors: Huang Yi‐Chen , Wu Cheng‐Che , Chung Sheng‐Heng 
Published: November 2024

AbstractAdvancing lithium‐sulfur battery technology requires addressing both extrinsic cell‐fabrication and intrinsic material challenges to improve efficiency, cyclability, and environmental sustainability. A key challenge is the low conductivity of sulfur cathodes, which is typically managed by incorporating conductive carbon materials. These materials enhance the performance of sulfur cathodes by facilitating high sulfur loading and improving polysulfide retention. In line with green chemistry principles and circular economy concepts, this study explores the use of recycled materials–specifically recycled quartz and board–as substrates for graphene coatings in lithium‐sulfur cells. Recycled quartz bricks and blocks, predominantly SiO2, and recycled shelf boards, rich in Al2O3, are successfully coated with graphene, which significantly improves polysulfide adsorption and overall battery performance. The graphene‐coated quartz exhibits high sulfur loading (8 mg cm−2), exceptional charge‐storage capacity (1,114 mA h g−1), and long cycle stability (200 cycles) with an energy density of 19 mW h cm−2. This approach enhances the electrochemical performance of the lithium‐sulfur cells and also aligns with sustainability goals by repurposing waste materials and minimizing environmental impact. This novel methodology demonstrates that integrating recycled materials can effectively address key challenges in lithium‐sulfur battery technology, advancing both performance and environmental sustainability.
Phenological mismatch is less important than total nectar availability for checkerspot butterflies
Authors: Crone Elizabeth E. , Arriens June V. , Brown Leone M. 
Published: November 2024

AbstractChanges in phenology are a conspicuous fingerprint of climate change, leading to fears that phenological mismatches among interacting species will be a leading cause of population declines and extinction. We used quantile regression to analyze museum collection data and estimate changes in the phenological overlap of Baltimore checkerspot butterflies and 12 common nectar plant species over several decades in two geographic regions. We combined these museum data with field estimates of each species' flower density and nectar sugar production to estimate changes in resource availability caused by shifts in phenological overlap. Phenological overlap (measured as the proportion of plant flowering during the flight period of an average butterfly) decreased through time, primarily because the flowering period of nectar plants was longer, but the flight period of butterflies was shorter in recent years. Our study was also motivated by the hypothesis that phenological mismatches may be more severe in the southern region due to a midsummer dearth in floral resources, but this hypothesis was not supported by our data. Although phenological overlap was somewhat smaller in the southern region, changes in overlap through time were similar in both regions. When phenological overlap was weighted by nectar sugar production of different species, the overlap increased in the southern region but decreased in the northern region (the opposite of our prediction). Overall, nectar resources were much more abundant at study sites in our northern region than in our southern region, possibly due to differences in land management. Our study demonstrates the complexities of phenological mismatch of interacting species and highlights that phenological changes may have small impacts on population viability.