bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enzyme Engineering for High‐Yielding Amide Formation: Lipase‐Catalyzed Synthesis of N‐Acyl Glycines in Aqueous Media
Authors: Kua Glen Kai Bin , Nguyen Giang Kien Truc , Li Zhi 
Published: February 2023

AbstractAmide syntheses remain a key challenging green chemistry reaction. For instance, green synthesis of N‐acyl glycines as biosurfactants and therapeutics is highly desirable to replace chemical pathways using toxic phosgene. Herein, we report a novel concept for enzymatic amidation in an aqueous system via glycerol activation of fatty acids and theirsubsequent aminolysis with glycine to synthesize N‐acyl glycines. We then engineer an enzyme (proRML) by reshaping its catalytic pocket to enhance its aminolysis activity and catalytic efficiency by 103‐fold and 465‐fold, respectively. The evolved proRML (D156S/L258K/L267N/S83D/L58K/R86K/W88V) catalyzed the amidation of a fatty acid with glycine to give N‐lauroylglycine with high yield (80 %). It accepts a broad range of medium‐ to long‐chain fatty acids (C8–C18), giving high yields of N‐decanoyl‐, N‐myristoyl‐, and N‐oleoylglycine. The developed amidation concept may be general, and the engineered enzyme is useful for the green synthesis of N‐acyl glycines.
Correlative Cellular Mass Spectrometry Imaging and Amperometry Show Dose Dependent Changes in Lipid Composition and Exocytosis
Authors: Barut Inci , He Xiulan , Sener Erol , Sämfors Sanna , Ewing Andrew G. , Fletcher John S. 
Published: February 2023

AbstractAberrant functioning of the proteasome has been associated with crucial pathologic conditions including neurodegeneration. Yet, the complex underlying causes at the cellular level remain unclear and there are conflicting reports of neuroprotective to neurodegenerative effects of proteasomal inhibitors such as lactacystin that are utilised as models for neurodegenerative diseases. The conflicting results may be associated with different dose regimes of lactacystin and hence we have performed a dose dependent study of the effects of lactacystin to identify concurrent changes in the cell membrane lipid profile and the dynamics of exocytosis using a combination of surface sensitive mass spectrometry and single cell amperometry. Significant changes of negatively charged lipids were associated with different lactacystin doses that showed a weak correlation with exocytosis while changes in PE and PE−O lipids showed dose dependent changes correlated with initial pore formation and total release of vesicle content respectively.
A Quadruply Bridged Non‐Offset Face‐to‐Face Porphyrin Dimer and Cross‐Shaped Pentameric Porphyrin Tapes Based on 2,7,12,17‐Tetrakis(pinacolatoboryl) NiII Porphyrin
Authors: Ye Meng , Deng Fangling , Xu Ling , Rao Yutao , Yin Bangshao , Zhou Mingbo , Kurosaki Ryo , Aratani Naoki , Osuka Atsuhiro , Song Jianxin 
Published: February 2023

Abstract2,7,12,17‐Tetrakis(pinacolatoboryl) NiII porphyrin 5 Ni was synthesized in 75 % yield by Ir‐catalyzed borylation of porphine followed by NiII metalation and has been demonstrated to be a useful synthon, giving 2,7,12,17‐tetraaryated NiII porphyrins 6 a–d, peripherally octaarylated NiII porphyrins 8 a–d, quadruply bridged face‐to‐face non‐offset NiII‐porphyrin dimer 12, and cross‐shaped β‐meso singly linked porphyrin pentamers and nonamers. Oxidation of cross‐shaped β‐meso singly linked porphyrin pentamers 14 Ni and 14 Zn gave fused pentameric tapes 15 Ni and 15 Zn. The structures of 12, 14 Zn, and 15 Ni have been revealed by X‐ray diffraction analysis. Optical separation of 12 has been accomplished, showing a bisignate coupling pattern for exciton‐coupled blue‐shifted Soret band. Pentameric porphyrin tape 15 Zn exhibits a red‐shifted absorption band at 1156 nm and seven reversible redox waves.
Managing Secondary Phase Lead Iodide in Hybrid Perovskites via Surface Reconstruction for High‐Performance Perovskite Solar Cells with Robust Environmental Stability
Authors: Ye Linfeng , Guo Pengfei , Su Jie , Zhang Kaiyuan , Liu Chen , Yang Penghui , Zhao Wenhao , Zhao Pengzhen , Liu Zhe , Chang Jingjing , Ye Qian , Wang Hongqiang 
Published: February 2023

AbstractRationally managing the secondary‐phase excess lead iodide (PbI2) in hybrid perovskite is of significance for pursuing high performance perovskite solar cells (PSCs), while the challenge remains on its conversion to a homogeneous layer that is robust stable against environmental stimuli. We herein demonstrate an effective strategy of surface reconstruction that converts the excess PbI2 into a gradient lead sulfate‐silica bi‐layer, which substantially stabilizes the perovskite film and reduces interfacial charge transfer barrier in the PSCs device. The perovskite films with such bi‐layer could bear harsh conditions such as soaking in water, light illumination at 70 % relative humidity, and the damp‐thermal (85 °C and 30 % humidity) environment. The resulted PSCs deliver a champion efficiency up to 24.09 %, as well as remarkable environmental stability, e.g., retaining 78 % of their initial efficiency after 5500 h of shelf storage, and 82 % after 1000 h of operational stability testing.
The Directional Crystallization Process of Poly (triazine imide) Single Crystals in Molten Salts
Authors: Liang Xiaocong , Xue Sikang , Yang Can , Ye Xiaoyuan , Wang Yulan , Chen Qidi , Lin Wei , Hou Yidong , Zhang Guigang , Shalom Menny , Yu Zhiyang , Wang Xinchen 
Published: February 2023

AbstractPoly (triazine imide) photocatalysts prepared via molten salt methods emerge as promising polymer semiconductors with one‐step excitation capacity of overall water splitting. Unveiling the molecular conjugation, nucleation, and crystallization processes of PTI crystals is crucial for their controllable structure design. Herein, microscopy characterization was conducted at the PTI crystallization front from meso to nano scales. The heptazine‐based precursor was found to depolymerize to triazine monomers within molten salts and KCl cubes precipitate as the leading cores that guide the directional stacking of PTI molecular units to form aggregated crystals. Upon this discovery, PTI crystals with improved dispersibility and enhanced photocatalytic performance were obtained by tailoring the crystallization fronts. This study advances insights into the directional assembling of PTI monomers on salt templates, placing a theoretical foundation for the ordered condensation of polymer crystals.
Spectroscopy vs. Electrochemistry: Catalyst Layer Thickness Effects on Operando/In Situ Measurements
Authors: Diercks Justus S. , Herranz Juan , Ebner Kathrin , Diklić Nataša , Georgi Maximilian , Chauhan Piyush , Clark Adam H. , Nachtegaal Maarten , Eychmüller Alexander , Schmidt Thomas J. 
Published: February 2023

AbstractIn recent years, operando/in situ X‐ray absorption spectroscopy (XAS) has become an important tool in the electrocatalysis community. However, the high catalyst loadings often required to acquire XA‐spectra with a satisfactory signal‐to‐noise ratio frequently imply the use of thick catalyst layers (CLs) with large ion‐ and mass‐transport limitations. To shed light on the impact of this variable on the spectro‐electrochemical results, in this study we investigate Pd‐hydride formation in carbon‐supported Pd‐nanoparticles (Pd/C) and an unsupported Pd‐aerogel with similar Pd surface areas but drastically different morphologies and electrode packing densities. Our in situ XAS and rotating disk electrode (RDE) measurements with different loadings unveil that the CL‐thickness largely determines the hydride formation trends inferred from spectro‐electrochemical experiments, therewith calling for the minimization of the CL‐thickness in such experiments and the use of complementary thin‐film control measurements.
The Origin of Solvent Deprotonation in LiI‐added Aprotic Electrolytes for Li‐O2 Batteries
Authors: Wang Aiping , Wu Xiaohong , Zou Zheyi , Qiao Yu , Wang Da , Xing Lidan , Chen Yuhui , Lin Yuxiao , Avdeev Maxim , Shi Siqi 
Published: February 2023

AbstractLiI and LiBr have been employed as soluble redox mediators (RMs) in electrolytes to address the sluggish oxygen evolution reaction kinetics during charging in aprotic Li‐O2 batteries. Compared to LiBr, LiI exhibits a redox potential closer to the theoretical one of discharge products, indicating a higher energy efficiency. However, the reason for the occurrence of solvent deprotonation in LiI‐added electrolytes remains unclear. Here, by combining ab initio calculations and experimental validation, we find that it is the nucleophile
that triggers the solvent deprotonation and LiOH formation via nucleophilic attack, rather than the increased solvent acidity or the elongated C−H bond as previously suggested. As a comparison, the formation of
in LiBr‐added electrolytes is found to be thermodynamically unfavorable, explaining the absence of LiOH formation. These findings provide important insight into the solvent deprotonation and pave the way for the practical application of LiI RM in aprotic Li‐O2 batteries.
pH‐Triggered Recovery of Organic Polymer Photocatalytic Particles for the Production of High Value Compounds and Enhanced Recyclability
Authors: Li Rong , Heuer Julian , Kuckhoff Thomas , Landfester Katharina , Ferguson Calum T. J. 
Published: February 2023

AbstractPseudo‐homogeneous polymeric photocatalysts are an emerging class of highly efficient and tunable photocatalytic materials, where the photocatalytic centers are easily accessible. The creation of highly efficient photocatalytic materials that can be rapidly separated and recovered is one of the critical challenges in photocatalytic chemistry. Here, we describe pH‐responsive photocatalytic nanoparticles that are active and well‐dispersed under acidic conditions but aggregate instantly upon elevation of pH, enabling easy recovery. These responsive photocatalytic polymers can be used in various photocatalytic transformations, including CrVI reduction and photoredox alkylation of indole derivative. Notably, the cationic nature of the photocatalyst accelerates reaction rate of an anionic substrate compared to uncharged species. These photocatalytic particles could be readily recycled allowing multiple successive photocatalytic reactions with no clear loss in activity.
Carboxylic Acid Salts as Dual‐Function Reagents for Carboxylation and Carbon Isotope Labeling
Authors: Wang Shuo , Larrosa Igor , Yorimitsu Hideki , Perry Gregory J. P. 
Published: February 2023

AbstractThe potassium salts of carboxylic acids are developed as efficient carboxylating agents through CO2 exchange. We describe these carboxylates as dual‐function reagents because they function as a combined source of CO2 and base/metalating agent. By using the salt of a commercially available carboxylic acid, this protocol overcomes difficulties when using CO2 gas or organometallic reagents, such as pressurized containers or strictly inert conditions. The reaction proceeds under mild conditions, does not require transition metals or other additives, and shows broad substrate scope. Through the preparation of several biologically important molecules, we show how this strategy provides an opportunity for isotope labeling with low equivalents of labeled CO2.
Organocatalytic Enantioselective Synthesis of Axially ChiralN,N′‐Bisindoles
Authors: Chen Zhi‐Han , Li Tian‐Zhen , Wang Ning‐Yi , Ma Xiao‐Fang , Ni Shao‐Fei , Zhang Yu‐Chen , Shi Feng 
Published: February 2023

AbstractThis study establishes the first organocatalytic enantioselective synthesis of axially chiralN,N′‐bisindoles via chiral phosphoric acid‐catalyzed formal (3+2) cycloadditions of indole‐based enaminones as novel platform molecules with 2,3‐diketoesters, where de novo indole‐ring formation is involved. Using this new strategy, various axially chiralN,N′‐bisindoles were synthesized in good yields and with excellent enantioselectivities (up to 87 % yield and 96 % ee). More importantly, this class of axially chiralN,N′‐bisindoles exhibited some degree of cytotoxicity toward cancer cells and was derived into axially chiral phosphine ligands with high catalytic activity. This study provides a new strategy for enantioselective synthesis of axially chiralN,N′‐bisindoles using asymmetric organocatalysis and is the first to realize the applications of such scaffolds in medicinal chemistry and asymmetric catalysis.
Engineered Binding Microenvironments in Halogen Bonding Polymers for Enhanced Anion Sensing
Authors: Bąk Krzysztof M. , Patrick Sophie C. , Li Xiaoxiong , Beer Paul D. , Davis Jason J. 
Published: February 2023

AbstractMimicking Nature's polymeric protein architectures by designing hosts with binding cavities screened from bulk solvent is a promising approach to achieving anion recognition in competitive media. Accomplishing this, however, can be synthetically demanding. Herein we present a synthetically tractable approach, by directly incorporating potent supramolecular anion‐receptive motifs into a polymeric scaffold, tuneable through a judicious selection of the co‐monomer. A comprehensive analysis of anion recognition and sensing is demonstrated with redox‐active, halogen bonding polymeric hosts. Notably, the polymeric hosts consistently outperform their monomeric analogues, with especially large halide binding enhancements of ca. 50‐fold observed in aqueous‐organic solvent mixtures. These binding enhancements are rationalised by the generation and presentation of low dielectric constant binding microenvironments from which there is appreciable solvent exclusion.
A Photoisomerizable Zinc (II) Complex Inhibits Microtubule Polymerization for Photoactive Therapy
Authors: Cao Fengshu , Wang Haobing , Lu Nong , Zhang Pingyu , Huang Huaiyi 
Published: February 2023

AbstractThe photoisomerization‐induced cytotoxicity in photopharmacology provides a unique pathway for phototherapy because it is independent of endogenous oxygen. In this study, we developed a biosafe photoisomerizable zinc(II) complex (Zn1), which releases its trans ligand (trans‐L1) after being irradiated with blue light. This causes the complex to undergo photoisomerization and produce the toxic cis product (cis‐L1) and generate singlet oxygen (1O2). The resulting series of events caused impressive phototoxicity in hypoxic A431 skin cancer cells, as well as in a tumor model in vivo. Interestingly, Zn1 was able to inhibit tumor microtubule polymerization, while still showing good biocompatibility and biosafety in vivo. This photoisomerizable zinc(II) complex provides a novel strategy for addressing the oxygen‐dependent limitation of traditional photodynamic therapy.
Effect of curing time on the mechanical properties of poly(glycerol sebacate)
Authors: Wu Zebin , Jin Kaixiang , Wang Lizhen , Fan Yubo 
Published: February 2023

AbstractBiodegradable polymers have been widely used in tissue engineering for their good biocompatibility, controlled mechanical properties and processability. Among them, poly(glycerol sebacate) (PGS) is a promising biodegradable polymer that has been used in diverse tissue engineering applications such as skin, muscle, cornea, nerve, vessel, cartilage, and so on. However, one of the synthesis parameters, curing time on PGS properties is still a confusing problem waiting to be resolved. In this article, PGS was cured for 0, 24, 36, 48, 60, 72, 84, and 96 h at 130°C and their properties were characterized by a series of techniques. Differential scanning calorimetry results indicated that the melting point, crystallization temperature, melting enthalpy and crystallization enthalpy of PGS decreased with the increase of curing time. Curing time was positively correlated to the degree of crosslinking. Longer curing time not only enhanced Young's modulus of PGS but also reduced its hydrophilicity. The Young's modulus of PGS curing for 96 h was about 5 times higher than that of PGS curing for 36 h. This study suggests that the effect of curing time on PGS properties provides detailed reference for potential applications.
Effects of halloysite nanotubes modified by organic phosphate on the performance improvement for polypropylene
Authors: Deng Zhaopeng , Meng Xin , Li Chenyang , Yao Zhongyang , Gong Weiguang 
Published: February 2023

AbstractThe enhancement of halloysite nanotubes (HNT) for polymer mechanical performance is limited due to the poor compatibility with matrix. In this work, hydrophobic 2,2′‐methylene‐bis‐(4,6‐di‐tert‐butylphenyl) organic phosphate (MBP) with multiple methyl groups was firstly used for HNT compatibilization modification. The hydrophobicity transition of modified HNT (HNT‐M) and the dispersibility difference in isotactic polypropylene (iPP) matrix were distinguished by water contact angle and SEM analyses, respectively. In addition, the binding energy evaluated the interfacial interaction and compatibility with matrix before and after modification by molecular dynamic simulation. Correspondingly, the iPP performance was optimized after addition of HNT‐M. The onset decomposition temperature of system at 5% and 10% weight loss was increased by 7 and 11°C compared with neat iPP, respectively. Moreover, the flexural modulus and impact strength of iPP/HNT‐M system were 18.9% and 9.6% higher than neat iPP showing simultaneous enhancement. In addition, iPP/HNT‐M system crystallized begin at higher temperature showing enhanced crystallization ability. Furthermore, the faster crystallization process and more uniform spherulite size were obtained. As a result, the enhancement for iPP performance was obtained when the compatibility between HNT and matrix was improved through surface modification.
Co‐catalytic system design for deriving reactive diluent to construct robust benzoxazine resin with microphase‐separated structure
Authors: Li Qing , Xiang Shuangfei , Fu Feiya , Liu Xiangdong , Zhao Shujun 
Published: February 2023

AbstractExploitation a facile and effective strategy for preparing benzoxazine resins with outstanding processability and robust mechanical properties still exists a challenge. In this work, a co‐catalytic concept was proposed to fabricate high‐performance benzoxazine resin by employing curing agent to derive reactive diluent to construct microphase‐separated system. Given on the design, the reactive diluent dissolved solid benzoxazine into a low‐viscosity solution, after which the curing agent presented a catalytic effect on diluent and benzoxazine to optimize the curing crosslinking reactions. As a result, it not only increased crosslinking density for a stable mechanical network, but also induced a microphase‐separated structure to effectively dissipate energy for a strong yet tough resin system, as proved by Fourier transform infrared, differential scanning calorimetry, and dynamic mechanical analyses measurements. Moreover, the as‐prepared modified benzoxazine resin showed great potential to fabricated composites with glass fiber, in which the values of tensile strength, elongation at break, and toughness presented an improvement of 212.1%, 106.8%, and 75.0% compared to composite with pristine PH‐ddm and glass fiber, respectively. These results suggested an effective path to improve the processability and overall mechanical properties of benzoxazine resins, opening a new strategy to develop high‐performance benzoxazine materials.
A graphite furnace‐atomic absorption spectrometry‐based rubidium efflux assay for screening activators of the Kv7.2/3 channel
Authors: Bartz Frieda‐Marie , Beirow Kristin , Wurm Konrad , Baecker Daniel , Link Andreas , Bednarski Patrick J. 
Published: February 2023

AbstractFor the characterization of Kv7.2/3 channel activators, several analytical methods are available that vary in effort and cost. In addition to the technically elaborate patch‐clamp method, which serves as a reference method, there exist several medium to high‐throughput screening methods including a rubidium efflux flame‐atomic absorption spectrometry (F‐AAS) assay and a commercial thallium uptake fluorescence‐based assay. In this study, the general suitability of a graphite furnace atomic absorption spectrometry (GF‐AAS)‐based rubidium efflux assay as a screening method for Kv7.2/3 channel activators was demonstrated. With flupirtine serving as a reference compound, 16 newly synthesizedcompounds and the known Kv7.2/3 activator retigabine were first classified as either active or inactive by using the GF‐AAS‐based rubidium (Rb) efflux assay. Then, the results were compared with a thallium (Tl) uptake fluorescence‐based fluorometric imaging plate reader (FLIPR) potassium assay. Overall, 16 of 17 compounds were classified by the GF‐AAS‐based assay in agreement with their channel‐activating properties determined by the more expensive Tl uptake, fluorescence‐based assay. Thus, the performance of the GF‐AAS‐based Rb assay for primary drug screening of Kv7.2/3‐activating compounds was clearly demonstrated, as documented by the calculated Z’‐factor of the GF‐AAS‐based method. Moreover, method development included optimization of the coating of the microtiter plates and the washing procedure, which extended the range of this assay to poorly adherent cells such as the HEK293 cells used in this study.
Transforming musculoskeletal anatomy learning with haptic surface painting
Authors: Shapiro Leonard , Hobbs Ella , Keenan Iain D. 
Published: February 2023

AbstractAnatomical body painting has traditionally been utilized to support learner engagement and understanding of surface anatomy. Learners apply two‐dimensional representations of surface markings directly on to the skin, based on the identification of key landmarks. Esthetically satisfying representations of musculature and viscera can also be created. However, established body painting approaches do not typically address three‐dimensional spatial anatomical concepts. Haptic Surface Painting (HSP) is a novel activity, distinct from traditional body painting, and aims to develop learner spatial awareness. The HSP process is underpinned by previous work describing how a Haptico‐visual observation and drawing method can support spatial, holistic, and collaborative anatomy learning. In HSP, superficial and underlying musculoskeletal and vascular structures are located haptically by palpation. Transparent colors are then immediately applied to the skin using purposive and cross‐contour drawing techniques to produce corresponding visual representations of learner observation and cognition. Undergraduate students at a United Kingdom medical school (n = 7) participated in remote HSP workshops and focus groups. A phenomenological study of learner perspectives identified four themes from semantic qualitative analysis of transcripts: Three‐dimensional haptico‐visual exploration relating to learner spatial awareness of their own anatomy; cognitive freedom and accessibility provided by a flexible and empowering learning process; altered perspectives of anatomical detail, relationships, and clinical relevance; and delivery and context, relating to curricular integration, session format, and educator guidance. This work expands the pedagogic repertoire of anatomical body painting and has implications for anatomy educators seeking to integrate innovative, engaging, and effective learning approaches for transforming student learning.