bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis‐Structure‐Catalysis Relations in CHA Zeolites Applied for Selective Catalytic Reduction of NOx with Ammonia
Authors: Tsunoji Nao , Onishi Misae , Sonoda Sou , Ohnishi Takeshi , Ogura Masaru , Maeno Zen , Toyao Takashi , Shimizu Ken‐ichi 
Published: May 2024

AbstractMicroporous aluminosilicate zeolites are useful industrial catalysts. However, their hydrothermal synthesis is a multistep process with complicated and unclear reactions, limiting their rational functional design. Herein, we compare the formation pathway and the structural and catalytic properties of several CHA zeolites to obtain fundamental knowledge for intentionally controlling the catalytic function of zeolites. Three CHA zeolites were synthesized using different starting silica/alumina sources in the presence of tetraethylammonium hydroxide as an inexpensive organic structure‐directing agent. FAU zeolite and an amorphous synthesis gel prepared using two different methods were used as starting materials. The obtained CHA zeolites were applied for exhaust gas purification (selective catalytic reduction of NOx with ammonia, NH3‐SCR), and their structural characteristics and formation pathways were investigated using a combination of analytical methods. Stepwise gel preparation (SGP), which divides the compositional control of the amorphous synthesis gel, promotes the decomposition of the initial additive (zeolite seed), resulting in the formation of CHA zeolites with abundant micropores and paired Al sites. This structural feature obtained using the SGP method improves the catalytic durability of the NH3‐SCR reaction. The present relationship, including different crystallization phenomena, structures, and catalytic abilities, provides useful insights into rational zeolite synthesis and its application.
Characterizing the Oligomers Distribution along the Aggregation Pathway of Amyloid Aβ1‐40 by NMR
Authors: Pagano Katiuscia , De Rosa Lucia , Tomaselli Simona , Molinari Henriette , D'Andrea Luca Domenico , Ragona Laura 
Published: May 2024

AbstractThis study delves into the early aggregation process of the Aβ1‐40 amyloid peptide, elucidating the associated oligomers distribution. Motivated by the acknowledged role of small oligomers in the neurotoxic damage linked to Alzheimer's disease, we present an experimental protocol for preparing 26‐O‐acyl isoAβ1‐40, a modified Aβ1‐40 peptide facilitating rapid isomerization to the native amide form at neutral pH. This ensures seed‐free solutions, minimizing experimental variability. Additionally, we demonstrate the efficacy of coupling NMR diffusion ordered spectroscopy (DOSY) with the Inverse Laplace Transform (ILT) reconstruction method, for effective characterization of early aggregation processes. This innovative approach efficiently maps oligomers distributions across a wide spectrum of initial peptide concentrations offering unique insights into the evolution of oligomers relative populations. As a proof of concept, we demonstrate the efficacy of our approach assessing the impact of Epigallocathechin gallate, a known remodeling agent of amyloid fibrils, on the oligomeric distributions of aggregated Aβ1‐40. The DOSY‐ILT proposed approach stands as a robust and discriminating asset, providing a powerful strategy for rapidly gaining insight into potential inhibitors’ impact on the aggregation process.
Striking Borane Planarization in the Thermal Rearrangement (η5‐C5H5)Fe(η3‐B5H10)→(η5‐C5H5)Fe(η5‐B5H10)
Authors: Ferrer Maxime , Alkorta Ibon , Elguero José , Barrios‐Llacuachaqui Julio R. , Tiznado William , Oliva‐Enrich Josep M. 
Published: May 2024

AbstractIn 1977 Weiss and Grimes, by means of mass spectrometry and 1H and 11B NMR spectroscopy, proposed two structures (I and II) for the ferraborane (η5‐C5H5)Fe(B5H10), isoelectronic with ferrocene. In this work, by means of high‐level quantum‐chemical computations, we confirm the experimental structures of the two isomers with their corresponding energies, and assign the reported 1H and 11B NMR chemical shifts. A striking result from this study is the planarization (3D→2D) of the B5H10− ligand – an unknown isolated anion, isoelectronic with aromatic cyclopentadienyl anion C5H5− – when attached to the (η5‐C5H5)Fe+ moiety, thus resulting in a more stable ferraborane isomer II.
Stereoselective Synthesis of 2‐Deoxy‐α‐N‐Glycosides from Glycals with 1,4,2‐Dioxazol‐5‐ones
Authors: Shen Zhenpeng , Yin Guoyin , Li Yangyang 
Published: May 2024

Comprehensive SummaryThe synthesis of N‐glycosides has received significant attention due to their crucial role in carbohydrate chemistry. Despite considerable advancements developed in the construction of N‐glycosides, methods for the stereoselective construction of 2‐deoxy‐α‐N‐glycosides are still limited. Herein, we disclosed a nickel‐catalyzed hydroamination of glycals under mild conditions. This transformation could allow for the stereoselective synthesis of an array of 2‐deoxy‐α‐N‐glycosides with excellent α‐stereoselectivity. Nickel‐catalyzed glycosylation reactions, particularly those involving anomeric C(sp3)‐metal bond formation, have proven to be an effective and stereoselective strategy for producing various N‐glycosides. Additionally, with highlight of the application of this reaction, γ‐sugar amino acid derivatives were synthesized.
Competitive Intramolecular Hydrogen Bonding: Offering Molecules a Choice
Authors: Sun Yu , Morton Evelyn R. , Bhabha Hunaida , Clark Ewan R. , Bučar Dejan‐Krešimir , Barros‐Metlova Victoria , Gould Jamie A. , Aliev Abil E. , Haynes Cally J. E. 
Published: May 2024

AbstractThe conformational preferences of N‐((6‐methylpyridin‐2‐yl)carbamothioyl)benzamide were studied in solution, the gas phase and the solid state via a combination of NMR, density functional theory (DFT) and single crystal X‐ray techniques. This acyl thiourea derivative can adopt two classes of low energy conformation, each stabilized by a different 6‐membered intramolecular hydrogen bond (IHB) pseudoring. Analysis in different solvents revealed that the conformational preference of this molecule is polarity dependent, with increasingly polar environments yielding a higher proportion of the minor conformer containing an NH⋅⋅⋅N IHB. The calculated barrier to interconversion is consistent with dynamic behaviour at room temperature, despite the propensity of 6‐membered IHB pseudorings to be static. This work demonstrates that introducing competitive IHB pathways can render static IHBs more dynamic and that such systems could have potential as chameleons in drug design.
Oxygen Atom from Carbonyl Group as an Important Binding Agent to the G‐Quadruplex – Study Case of Flavonoids
Authors: Stężycka Olga , Kasperkowiak Małgorzata , Frańska Magdalena , Nowak Damian , Hoffmann Marcin 
Published: May 2024

AbstractIn the field of anticancer therapy study it is of great interest to find effective G‐quadruplex ligands which may be of potential use in medical treatment or cancer prevention. Since among the compounds of natural origin, flavonoids have attracted notable attention because of their unique properties and promising therapeutic applications, an interesting question was to identify the flavonoid structural features that could provide effective binding properties toward G‐quadruplex. By using electrospray ionization mass spectrometry, followed by the survival yield method, it has been shown that the flavonoid molecules which contain an available C4=O carbonyl group form more stable adducts with G‐tetrads than the other ones. Molecular docking has shown that C4=O carbonyl group can be a source of hydrogen bonds and/or π‐stacking interactions. Therefore, the flavonoid molecules which contain an available C4=O carbonyl group can be regarded as good binders of G‐quadruplexes.
Establishment of Transgene‐Free Porcine Induced Pluripotent Stem Cells
Authors: Conrad J. Vanessa , Neira Jaime A. , Rusteika Margaret , Meyer Susanne , Clegg Dennis O. , Chu Li‐Fang 
Published: May 2024

AbstractAlthough protocols to generate authentic transgene‐free mouse and human induced pluripotent stem cells (iPSCs) are now well established, standard methods for reprogramming porcine somatic cells still suffer from low efficiency and transgene retention. The Basic Protocol describes reprogramming procedures to establish transgene‐free porcine iPSCs (PiPSCs) from porcine fibroblasts. This method uses episomal plasmids encoding POU5F1, SOX2, NANOG, KLF4, SV40LT, c‐MYC, LIN28A, and microRNA‐302/367, combined with an optimized medium, to establish PiPSC lines. Support protocols describe the establishment and characterization of clonal PiPSC lines, as well as the preparation of feeder cells and EBNA1 mRNA. This optimized, step‐by‐step approach tailored to this species enables the efficient derivation of PiPSCs in ∼4 weeks. The establishment of transgene‐free PiPSCs provides a new and valuable model for studies of larger mammalian species’ development, disease, and regenerative biology. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC.Basic Protocol: Reprogramming of porcine fibroblasts with episomal plasmidsSupport Protocol 1: Preparation of mouse embryonic fibroblasts for feeder layerSupport Protocol 2: Preparation of in vitro–transcribed EBNA1 mRNASupport Protocol 3: Establishment of clonal porcine induced pluripotent stem cell (PiPSC) linesSupport Protocol 4: PiPSC characterization: Genomic DNA PCR and RT‐PCRSupport Protocol 5: PiPSC characterization: Immunostaining
Minimizing Variability in Developmental Fear Studies in Mice: Toward Improved Replicability in the Field
Authors: Premachandran Hanista , Wilkin Jennifer , Arruda‐Carvalho Maithe 
Published: May 2024

AbstractIn rodents, the first weeks of postnatal life feature remarkable changes in fear memory acquisition, retention, extinction, and discrimination. Early development is also marked by profound changes in brain circuits underlying fear memory processing, with heightened sensitivity to environmental influences and stress, providing a powerful model to study the intersection between brain structure, function, and the impacts of stress. Nevertheless, difficulties related to breeding and housing young rodents, preweaning manipulations, and potential increased variability within that population pose considerable challenges to developmental fear research. Here we discuss several factors that may promote variability in studies examining fear conditioning in young rodents and provide recommendations to increase replicability. We focus primarily on experimental conditions, design, and analysis of rodent fear data, with an emphasis on mouse studies. The convergence of anatomical, synaptic, physiological, and behavioral changes during early life may increase variability, but careful practice and transparency in reporting may improve rigor and consensus in the field. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC.
Heterogeneous Ni‐Boride/Phosphide Anchored Amorphous B‐C Layer for Overall Water Electrocatalysis
Authors: Song Shiwei , Wang Yanhui , Liu Yucan , Tian Pengfei , Zang Jianbing 
Published: May 2024

AbstractThe rational design of efficient and economical bifunctional electrocatalysts remained a challenge for overall water electrolysis. In this work, the Ni‐boride/ phosphide particles anchored amorphous B‐doped carbon layer with hierarchical porous characteristics in Ni foam (Ni3P/Ni3B/B−C/NF) was fabricated for overall water splitting. The Boroncarbide (B4C) power was filled and fixed in the NF interspace through the electroplating and electroless plating, and then annealed in vacuum high temperature. The amorphous B−C layer derived from the B4 C not only speeded up the electron transport, but also cooperate with Ni‐boride/phosphide to enhance the electrocatalytic activity for HER and OER synergistically. Furthermore, the hierarchical porous architecture of Ni3P/Ni3B/B−C/NF increased space utilization to load more active materials. The self‐supported Ni3P/Ni3B/B−C/NF electrode possessed a low overpotential of 212 and 280 mV to deliver 100 mA cm−2 for HER and OER, respectively, and high stability for 48 h. In particular, the electrolyzer constituted with the Ni3P/Ni3B/B−C/NF bifunctional electrocatalyst only required a voltage of 1.59 V at 50 mA cm−2 for water electrocatalysis under alkaline medium, and demonstrated long‐term stability for 48 h. This study provides a new technical path for the development of bifunctional of transition metal borides to promote the application of hydrogen production from water splitting.
PI3K/mTOR inhibition induces tumour microenvironment remodelling and sensitises pS6high uterine leiomyosarcoma to PD‐1 blockade
Authors: De Wispelaere Wout , Annibali Daniela , Tuyaerts Sandra , Messiaen Julie , Antoranz Asier , Shankar Gautam , Dubroja Nikolina , Herreros‐Pomares Alejandro , Baiden‐Amissah Regina E. M. , Orban Marie‐Pauline , Delfini Marcello , Berardi Emanuele , Van Brussel Thomas , Schepers Rogier , Philips Gino , Boeckx Bram , Baietti Maria Francesca , Congedo Luigi , HoWangYin Kiave Yune , Bayon Emilie , Van Rompuy Anne‐Sophie , Leucci Eleonora , Tabruyn Sebastien P. , Bosisio Francesca , Mazzone Massimiliano , Lambrechts Diether , Amant Frédéric 
Published: May 2024

AbstractBackgroundUterine leiomyosarcomas (uLMS) are aggressive tumours with poor prognosis and limited treatment options. Although immune checkpoint blockade (ICB) has proven effective in some ‘challenging‐to‐treat’ cancers, clinical trials showed that uLMS do not respond to ICB. Emerging evidence suggests that aberrant PI3K/mTOR signalling can drive resistance to ICB. We therefore explored the relevance of the PI3K/mTOR pathway for ICB treatment in uLMS and explored pharmacological inhibition of this pathway to sensitise these tumours to ICB.MethodsWe performed an integrated multiomics analysis based on TCGA data to explore the correlation between PI3K/mTOR dysregulation and immune infiltration in 101 LMS. We assessed response to PI3K/mTOR inhibitors in immunodeficient and humanized uLMS patient‐derived xenografts (PDXs) by evaluating tumour microenvironment modulation using multiplex immunofluorescence. We explored response to single‐agent and a combination of PI3K/mTOR inhibitors with PD‐1 blockade in humanized uLMS PDXs. We mapped intratumoural dynamics using single‐cell RNA/TCR sequencing of serially collected biopsies.ResultsPI3K/mTOR over‐activation (pS6high) associated with lymphocyte depletion and wound healing immune landscapes in (u)LMS, suggesting it contributes to immune evasion. In contrast, PI3K/mTOR inhibition induced profound tumour microenvironment remodelling in an ICB‐resistant humanized uLMS PDX model, fostering adaptive anti‐tumour immune responses. Indeed, PI3K/mTOR inhibition induced macrophage repolarisation towards an anti‐tumourigenic phenotype and increased antigen presentation on dendritic and tumour cells, but also promoted infiltration of PD‐1+ T cells displaying an exhausted phenotype. When combined with anti‐PD‐1, PI3K/mTOR inhibition led to partial or complete tumour responses, whereas no response to single‐agent anti‐PD‐1 was observed. Combination therapy reinvigorated exhausted T cells and induced clonal hyper‐expansion of a cytotoxic CD8+ T‐cell population supported by a CD4+ Th1 niche.ConclusionsOur findings indicate that aberrant PI3K/mTOR pathway activation contributes to immune escape in uLMS and provides a rationale for combining PI3K/mTOR inhibition with ICB for the treatment of this patient population.
Safety and efficacy of low‐power pure‐cut hot snare polypectomy for small nonpedunculated colorectal polyps compared with conventional resection methods: A propensity score matching analysis
Authors: Kimura Hidenori , Oi Masayuki , Imai Kenichiro , Imai Takayuki , Morita Yukihiro , Nishida Atsushi , Bamba Shigeki , Inatomi Osamu , Andoh Akira 
Published: May 2024

AbstractObjectivesCold snare polypectomy (CSP) is widely performed for small colorectal polyps. However, small colorectal polyps sometimes include high‐grade adenomas or carcinomas that require endoscopic resection with electrocautery. This study aimed to evaluate the efficacy and safety of a novel resection technique, hot snare polypectomy with low‐power pure‐cut current (LPPC‐HSP) for small colorectal polyps, compared with CSP and conventional endoscopic mucosal resection (EMR).MethodsRecords of patients who underwent CSP, EMR, or LPPC‐HSP for nonpedunculated colorectal polyps less than 10 mm between April 2021 and March 2022 were retrospectively evaluated. We analyzed and compared the treatment outcomes of CSP and EMR with those of LPPC‐HSP using propensity score matching.ResultsAfter propensity score matching of 396 pairs, an analysis of CSP and LPPC‐HSP indicated that LPPC‐HSP had a significantly higher R0 resection rate (84% vs. 68%; p < 0.01). Delayed bleeding was observed in only two cases treated with CSP before matching. Perforation was not observed with either treatment. After propensity score matching of 176 pairs, an analysis of EMR and LPPC‐HSP indicated that their en bloc and R0 resection rates were not significantly different (99.4% vs. 100%, p = 1.00; 79% vs. 81%, p = 0.79). Delayed bleeding and perforation were not observed with either treatment.ConclusionsThe safety of LPPC‐HSP was comparable to that of CSP. The treatment outcomes of LPPC‐HSP were comparable to those of conventional EMR for small polyps. These results suggest that this technique is a safe and effective treatment for nonpedunculated polyps less than 10 mm.
A comprehensive review of experimental studies on shear behavior of bolted rock joints with varying rock joint and bolt parameters and normal stress
Authors: Zhou Chang , Lang Zhenwei , Huang Shun , Dong Qinghong , Wang Yanzhi , Zheng Wenbo 
Published: May 2024

AbstractThe shear characteristics of bolted rock joints are crucial for the stability of tunneling and mining, particularly in deep underground engineering, where rock bolt materials are exposed to high stress, water pressure, and engineering disturbance. However, due to the complex interaction between bolted rock joints and various geological contexts, many challenges and unsolved problems arise. Therefore, more investigation is needed to understand the shear performance of bolted joints in the field of deep underground engineering. This study presents a comprehensive review of research findings on the responses of bolted joints subjected to shearing under different conditions. As is revealed, the average shear strength of bolted rock joints increases linearly with the normal stress and increases with the compressive strength of rock until it reaches a stable value. The joint roughness coefficient (JRC) affects the contact area, friction force, shear strength, bending angle, and axial force of bolted rock joints. A mathematical function is proposed to model the relationship between JRC, normal load, and shear strength. The normal stress level also influences the deformation model, load‐carrying capacity, and energy absorption ratio of bolts within bolted rock joints, and can be effectively characterized by a two‐phase exponential equation. Additionally, the angle of the bolts affects the ratio of tensile and shear strength of the bolts, as well as the mechanical behavior of both bolted rock joints and surrounding rock, which favors smaller angles. This comprehensive review of experimental data on the shear behavior of bolted rock joints offers valuable theoretical insights for the development of advanced shear devices and further pertinent investigations.
Broad‐scale acoustic monitoring of koala populations suggests metapopulation stability, but varying bellow rate, in the face of major disturbances and climate extremes
Authors: Law Bradley , Gonsalves Leroy , Brassil Traecey , Kerr Isobel 
Published: May 2024

AbstractPopulation trends are lacking for most threatened species, especially those that are cryptic and difficult to survey. Recent developments in passive acoustics and semi‐automated call recognition provide a cost‐effective option to systematically monitor populations of vocal species. We assessed recent trends for the koala Phascolarctos cinereus, an iconic marsupial, based on 7 years of acoustic monitoring across 224 forested sites. The study period overlapped with a severe drought and extensive megafires in 2019 followed by 2 years of extremely high rainfall. Dynamic occupancy modelling with a range of covariates at multiple landscape scales found that initial occupancy was related to elevation (−ve), NDVI (+ve) and previous selective harvesting (16–30‐year age class; weakly +ve). Extinction probability increased with the extent of high‐severity fire. Colonisation probability was related to a range of factors, with the top model showing a decrease with increasing lagged annual rainfall. However, the null model was also supported, suggesting weak associations for colonisation. Using these relationships, koala occupancy was found to be high and stable over the study period. Fire did not influence regional trends because koalas often persisted with low‐ to moderate‐severity fire and because high‐severity fire was limited to 11% of their habitat. In contrast, bellow rate varied across years, being initially low and declining immediately after the 2019 fires, with the driver of these changes unclear. Neither timber harvesting nor low‐severity fire influenced koala occupancy or bellow rate. Given the extensive area of koala habitat in the region, our results point to the presence of a large population in these public forests, and in recent years, stable occupancy (albeit with site‐scale reductions in density with high‐severity fire). Ongoing monitoring is crucial for tracking future changes, especially with predictions of more frequent, severe forest fires due to climate change.
Synthesis of 1,4‐Disubstituted and 1‐Substituted β‐Carbolines via 3‐Substituted 2‐Acylindoles
Authors: Thees Katharina , Untergehrer Martin , Jourjine Ilya A. P. , Bracher Franz 
Published: May 2024

Abstractβ‐Carbolines represent a large class of bioactive natural products, whereby most of these alkaloids bear residues at C1, and occasionally at C3, and only limited examples of 1,4‐disubstituted β‐carbolines are known. In this project we worked out a novel approach to 1,4‐disubstituted β‐carbolines and performed a comprehensive analysis of the scope and limitations of this methodology. The 1,4‐disubstituted β‐carbolines were synthesized via 3‐substituted 2‐acylindoles, for which effective synthesis procedures were developed. Our studies revealed that a broad range of target compounds with electron‐withdrawing substituents at C4 are accessible. Limitations of this method arose from competing CH and NH acidities of precursors. Nevertheless, the work described herein provides a unique approach to highly substituted β‐carbolines. In addition, intermediates from this route opened a novel approach to 1‐substituted β‐carbolines utilizing a chemoselective Mo(CO)6‐catalyzed amide reduction with tetramethyldisiloxane.
Brønsted Acid Catalyzed Dehydroxylative Cyanation of Benzylic Alcohols with Trimethylsilyl Cyanide Using 1,1,1,3,3,3‐Hexafluoro‐2‐propanol as a Solvent
Authors: Makino Kosho , Hasebe Mai , Sueki Shunsuke , Anada Masahiro 
Published: May 2024

AbstractA concise and direct Brønsted acid catalyzed cyanation of secondary and tertiary benzylic and allylic alcohols has been developed using trimethylsilyl cyanide (TMSCN) as a cyanide source and 1,1,1,3,3,3‐hexafluoro‐2‐propanol (HFIP) as a solvent. The present transition‐metal‐free catalytic process is operationally simple to perform under “open‐flask” conditions and is applicable to the preparation of a number of α‐arylacetonitriles as well as late‐stage material transformations. The effectiveness of the present protocol was further demonstrated by the first enantioselective synthesis and determination of the absolute configuration of verimol F.