bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemoenzymatic Synthesis of Glycopeptides to Explore the Role of Mucin 1 Glycosylation in Cell Adhesion
Authors: Bello Claudia , Pranzini Erica , Piemontese Emanuele , Schrems Maximilian , Taddei Maria Letizia , Giovannelli Lisa , Schubert Mario , Becker Christian F. W. , Rovero Paolo , Papini Anna Maria
Published: March 2023

Post‐translational modifications affect protein biology under physiological and pathological conditions. Efficient methods for the preparation of peptides and proteins carrying defined, homogeneous modifications are fundamental tools for investigating these functions. In the case of mucin 1 (MUC1), an altered glycosylation pattern is observed in carcinogenesis. To better understand the role of MUC1 glycosylation in the interactions and adhesion of cancer cells, we prepared a panel of homogeneously O‐glycosylated MUC1 peptides by using a quantitative chemoenzymatic approach. Cell‐adhesion experiments with MCF‐7 cancer cells on surfaces carrying up to six differently glycosylated MUC1 peptides demonstrated that different glycans have a significant impact on adhesion. This finding suggests a distinct role for MUC1 glycosylation patterns in cancer cell migration and/or invasion. To decipher the molecular mechanism for the observed adhesion, we investigated the conformation of the glycosylated MUC1 peptides by NMR spectroscopy. These experiments revealed only minor differences in peptide structure, therefore clearly relating the adhesion behaviour to the type and number of glycans linked to MUC1.
Altering the Modular Architecture of Galectins Affects its Binding with Synthetic α‐Dystroglycan O‐Mannosylated Core M1 Glycoconjugates In situ
Authors: Villones Lareno L. , Ludwig Anna‐Kristin , Kikuchi Seiya , Ochi Rika , Nishimura Shin‐Ichiro , Gabius Hans‐Joachim , Kaltner Herbert , Hinou Hiroshi
Published: March 2023

The multifunctionality of galectins helps regulate a broad range of fundamental cellular processes via cis‐binding and trans‐bridging activities and has gained widespread attention with respect to the importance of the natural specificity/selectivity of this lectin family to its glycoconjugate receptors. Combining galectin (Gal)‐1, −3, −4, and −9 variant test panels, achieved via rational protein engineering, and a synthetic α‐dystroglycan (DG) O‐Mannosylated core M1 glycopeptide library, a detailed comparative analysis was performed, utilizing microarray experiments to delineate the design‐functionality relationships within this lectin family. Enhancement of prototype Gal‐1 and chimera‐type Gal‐3 cis‐binding toward the prepared ligands is possible by transforming these lectins into tandem‐repeat type and prototypes, respectively. Furthermore, Gal‐1 variants demonstrated improved trans‐bridging capabilities between core M1 α‐DG glycopeptides and laminins in microarray, suggesting the possible translational applications of these galectin variants in the treatment of some forms of α‐dystroglycanopathy.
Chemical Biology Approaches toward Precise Structure Control of IgG‐Based Antibody‐Oligonucleotide Conjugates
Authors: Shen Lin , Wu Yuanyuan , Xie Wenxue , Chen Guangyao , Xing Hang
Published: March 2023

Antibody‐oligonucleotide conjugates (AOCs) are important tools for drug development and biochemical analysis. However, the structural heterogeneity of AOCs synthesized through conventional coupling methods raises reproducibility and safety concerns in clinical trials. To address these issues, different covalent coupling approaches have been developed to synthesize AOCs with precise site‐specificity and degree of conjugation. This Concept article categorizes these approaches as linker‐free or linker‐mediated and provides details on their chemistry and potential applications. Several factors, including site‐specificity, conjugation control, accessibility, stability, and efficiency, are highlighted when evaluating the pros and cons of these approaches. The article also discusses the future of AOCs, including the development of better conjugation approaches to ensure stimuli‐responsive release and the application of high‐throughput methods to facilitate their development.
Bioresorbable stents: We have more work to do
Authors: El Hajj Milad , Krajcer Zvonimir
Published: March 2023

Key Points

The NeoVas sirolimus‐eluting bioresorbable stent is safe and efficacious for treating de novo coronary artery disease.

Lesion and patient‐specific characteristics may play a role in the long‐term safety profile of bioresorbable stents.

The role of bioresorbable scaffolds in complex coronary lesions needs to be further elucidated.
Exploring the Promotion of γ‐Al2O3 on Pd/CeO2‐Catalyzed Low‐Concentration Methane Oxidation Using Operando DRIFTS‐MS
Authors: Li Tao , Dong Mengling , Xu Jiacheng , Zhang Tiantian , Sun Yan , Li Ning , Wu Zuliang , Li Jing , Gao Erhao , Zhu Jiali , Yao Shuiliang , Huang Yong
Published: March 2023

CeO2/γ‐Al2O3, Pd/CeO2, and Pd/CeO2/γ‐Al2O3 were used for catalyzing low‐concentration CH4 oxidation. It was found that nano‐sized Pd could obviously promote CH4 oxidation on CeO2/γ‐Al2O3. The interaction between Pd and CeO2 on γ‐Al2O3 resulted in higher ratios of Ce3+/(Ce3++Ce4+), Pd2+/(Pd2++Pdδ+), and Oads/(Oads+Olatt), those benefited the formation of more oxygen vacancies and surface reactive oxygen species for CH4 oxidation. γ‐Al2O3 not only supplied a high surface area and enhanced Pd/CeO2 dispersion on γ‐Al2O3, but also simulated the formation of bicarbonate, where bicarbonate is easier to gasify to CO2 than bidentate carbonate that formed on Pd/CeO2. Operando diffuse reflectance infrared Fourier transform spectroscopy‐mass spectrometer analysis results showed that CH4 oxidation could occur at a temperature as low as 180 °C due to the reaction with surface reactive OH, this reaction was also accompanied by the formation of bicarbonate. The mechanism of CH4 oxidation promoted by bicarbonate formation on γ‐Al2O3 was proposed.
Vanadium Pentafulvene Complexes: Synthon for Unprecedented VanadoceneIIIDerivatives
Authors: de Graaff Simon , Schwitalla Kevin , Thye Hermann , Yusufzadeh Zainab , Willms Michael , Schmidtmann Marc , Beckhaus Rüdiger
Published: March 2023

The benzene ligand at CpV(η6−C6H6) (1) is exchanged for pentafulvenes. Using sterically demanding pentafulvenes gives a clean exchange reaction, yielding vanadium pentafulvene (2 aand2 b) and benzofulvene complexes (3 aand3 b). The molecular structures of the target compounds suggest a π‐η5:σ‐η1coordination mode with a vanadiumIIIcenter. With the sterically low demanding 6,6‐dimethylpentafulvene, a C−H activation at the leaving ligand is observed, yielding the ring‐substituted vanadoceneII4. The reactivity of the pentafulvene complexes was investigated. A series of unprecedented vanadoceneIIIcompounds were synthesized: Under mild conditions, E−H splitting of 4‐tert‐butylphenol, diphenylamine, and 2,6‐diisopropylaniline yield well characterized examples of rare vanadoceneIIIphenolate and amide complexes. Insertion reactions into the V−Cexobond of the pentafulvene complexes by multiple bond containing substrates were found for acetone, 4‐chlorobenzonitril andN,N’‐dicyclohexylcarbodiimide.
Integrating Regioselective E→Z Isomerization of Trienones with Cascade Sequences under Photosensitizer‐Free Direct Irradiation at 390 nm
Authors: Maity Rajib , Ghosh Subhadeep , Das Indrajit
Published: March 2023

The regioselective E→Z isomerization of a target olefin unit embedded in a conjugated polyene is challenging. Examples are limited to retinal and its derivatives only. The problem is further amplified when such an isomerization is integrated into cascade sequences, among which the regioselectivity and subsequent directionality are the major bottlenecks. Indeed, there are no reports till date for such a transformation. Herein, it is reported that such a controlled isomerization and subsequent cyclization cascade can be enabled by photosensitizer‐free direct irradiation of linearly conjugated acyclic polyenes in dichloromethane solvent using a 390 nm LED. The directionality results from deconjugation of the extended π‐system in the transient Z‐isomer due to stabilizing n→π* interactions between 1,4‐dicarbonyls (C=O→C=O) or 1,4‐carbonyl/‐aryl (C=O→aryl) groups. The involvement of such noncovalent interactions has been supported by X‐ray crystallography and control experiments. Thus, conjugated trienones can be stereoselectively converted into oxabicyclo[3.2.1]octadienes in an atom‐ and step‐economic manner, including the first example by regioselective isomerization of a tetrasubstituted alkene. The reaction conditions are very general (>46 examples). The reaction can be conducted under open air atmosphere at ambient temperature. Such a cascade cyclization can also be realized in solid state.
Photomodulation on Active Sites of Adsorbents: Controllable Adsorption Processes with Improved Efficiency
Authors: Tan Peng , Bao Yu‐Fen , Liu Ding‐Hua , Liu Xiao‐Qin , Sun Lin‐Bing
Published: March 2023

Adsorption is a widely applied technique in producing high‐purity chemicals with advantages of low energy consumption, high selectivity, and mild operating conditions. However, traditional adsorbents have inflexible properties and suffer from the trade‐off between selective adsorption and efficient desorption. Recently, the emerging photoresponsive adsorbents have provided new avenues for adsorption techniques. Active sites of photoresponsive adsorbents can be regulated through steric hindrance or tunable adsorbent‐adsorbate interactions. Therefore, variation in adsorptive capacity is able to readily achieve through photomodulation, and the corresponding adsorption/desorption cycles are energy‐saving. This concept mainly summarizes recent efforts on the fabrication and application of photoresponsive adsorbents with tunable active sites. Also, the future opportunities and critical challenges of photoregulation on adsorptive sites are presented.
Biocatalytic Cascade Synthesis of Enantioenriched Epoxides and Triols from Biomass‐Derived Synthons Driven by Specifically Designed Enzymes
Authors: Grandi Eleonora , Crotti Michele , Sigmund Marie‐Cathérine , Xu Guangcai , Tepper Pieter G. , Poelarends Gerrit J.
Published: March 2023

Multi‐enzymatic cascades exploiting engineered enzymes are a powerful tool for the tailor‐made synthesis of complex molecules from simple inexpensive building blocks. In this work, we engineered the promiscuous enzyme 4‐oxalocrotonate tautomerase (4‐OT) into an effective aldolase with 160‐fold increased activity compared to 4‐OT wild type. Subsequently, we applied the evolved 4‐OT variant to perform an aldol condensation, followed by an epoxidation reaction catalyzed by a previously engineered 4‐OT mutant, in a one‐pot two‐step cascade for the synthesis of enantioenriched epoxides (up to 98 % ee) from biomass‐derived starting materials. For three chosen substrates, the reaction was performed at milligram scale with product yields up to 68 % and remarkably high enantioselectivity. Furthermore, we developed a three‐step enzymatic cascade involving an epoxide hydrolase for the production of chiral aromatic 1,2,3‐prim,sec,sec‐triols with high enantiopurity and good isolated yields. The reported one‐pot, three‐step cascade, with no intermediate isolation and being completely cofactor‐less, provides an attractive route for the synthesis of chiral aromatic triols from biomass‐based synthons.
Messebericht ACHEMA 2022: Zerkleinern
Authors: Mütze Thomas
Published: March 2023

Auf der ACHEMA 2022 waren in Frankfurt 38 Anbieter von Zerkleinerungstechnik vertreten. Der vorliegende Bericht fasst kurz zusammen, welche Aussteller vertreten waren und was – vor allem an Neuerungen – gezeigt wurde. Schwerpunkte waren einerseits Maschinen zum Dispergieren verklumpter bzw. sehr feinkörniger Pulver zur besseren Verarbeitbarkeit oder zum Einmischen in Flüssigkeiten sowie andererseits Mahlkörpermühlen zur Fein‐ und Feinstmahlung.
Advancements in droplet reactor systems represent new opportunities in chemical reactor engineering: A perspective
Authors: Zhang Meng , Vokoun Asher E. , Chen Boyuan , Deng Weichen , Dupont Robert L. , Xu Yang , Wang Xiaoguang
Published: March 2023

Traditional chemical reactors, such as batch reactors, continuous reactors, and semi‐batch reactors, have been extensively studied and frequently act as central components of modern chemical plants. Recently, various advances in reaction times, surface‐to‐volume ratios, required amounts of reagents, and throughput have led to new directions in the design of miniaturized chemical reactors. In this Perspective, we provide an overview of the progress from traditional to miniaturized chemical reactors by summarizing the characteristics and applications of different types of reactors. Furthermore, we compare classical chemical reactors and miniaturized droplet reactors to highlight advancements in the design of droplet reactor systems based on open functional surfaces. Finally, we provide an outlook on the research directions of miniaturized droplet reactors.
Molecular and cellular level characterization of cytoskeletal mechanics using a quartz crystal microbalance
Authors: Kerivan Emily M. , Tobin Lyle , Basil Mihir , Reinemann Dana N.
Published: March 2023

A quartz crystal microbalance (QCM) is an instrument that has the ability to measure nanogram‐level changes in mass on a quartz sensor and is traditionally used to probe surface interactions and assembly kinetics of synthetic systems. The addition of dissipation monitoring (QCM‐D) facilitates the study of viscoelastic systems, such as those relevant to molecular and cellular mechanics. Due to real‐time recording of frequency and dissipation changes and single protein‐level precision, the QCM‐D is effective in interrogating the viscoelastic properties of cell surfaces and in vitro cellular components. However, few studies focus on the application of this instrument to cytoskeletal systems, whose dynamic parts create interesting emergent mechanics as ensembles that drive essential tasks, such as division and motility. Here, we review the ability of the QCM‐D to characterize key kinetic and mechanical features of the cytoskeleton through in vitro reconstitution and cellular assays and outline how QCM‐D studies can yield insightful mechanical data alone and in tandem with other biophysical characterization techniques.
CYP3A4 Catalyzes the Rearrangement of the Dual Orexin Receptor Antagonist Daridorexant to 4‐Hydroxypiperidinol Metabolites
Authors: Treiber Alexander , Aissaoui Hamed , Delahaye Stéphane , Glutz Sven , Grimont Julien , Müller Claus , Seeland Swen , Siefken Valérie , Boss Christoph
Published: March 2023

The dual orexin receptor antagonist daridorexant was approved in 2022 in the USA and EU for the treatment of insomnia. The purpose of this study was the identification of its metabolic pathways and the human cytochrome P450 (P450) enzymes involved in its biotransformation. With human liver microsomes, daridorexant underwent hydroxylation at the methyl group of the benzimidazole moiety, oxidative O‐demethylation of the anisole to the corresponding phenol, and hydroxylation to a 4‐hydroxy piperidinol derivative. While the chemical structures of the benzylic alcohol and the phenol proved to be products of standard P450 reactions, 1D and 2D NMR data of the latter hydroxylation product was incompatible with the initially postulated hydroxylation of the pyrrolidine ring and suggested the disappearance of the pyrrolidine ring and formation of a new 6‐membered ring. Its formation is best explained by initial hydroxylation of the pyrrolidine ring in 5‐position to yield a cyclic hemiaminal. Hydrolytic ring opening then results in an aldehyde that subsequently cyclizes onto one of the benzimidazole nitrogen atoms to yield the final 4‐hydroxy piperidinol. The proposed mechanism was substantiated using an N‐methylated analogue, which might hydrolyze to the open‐chain aldehyde but cannot undergo the final cyclization step. CYP3A4 was the major P450 enzyme responsible for daridorexant metabolism, accounting for 89 % of metabolic turnover.
Bis‐Catecholamide‐Based Materials for Uranium Extraction
Authors: Mossand Guillaume , Lelong Evan , Xing Chen , Ndebulia Watchou Frantz , Leydier Antoine , Arrachart Guilhem , Pellet‐Rostaing Stéphane
Published: March 2023

Invited for this month′s cover is the collaborating group of Dr Guilhem Arrachart and Dr Stéphane Pellet‐Rostaing at Institut de Chimie Séparative de Marcoule (ICSM). The cover picture shows a person going uranium fishing thanks to the use of bis‐catecholamide materials. These materials have shown interesting performance for the recovery of uranium in saline environments such as seawater. More information can be found in the Research Article by G. Arrachart, S. Pellet‐Rostaing, and co‐workers.
Thermal Decomposition Assisted Construction of Nano‐Li3N Sites Interface Layer Enabling Homogeneous Li Deposition
Authors: Li Hongyang , Li Ling , Zheng Jingang , Huang Hao , Zhang Han , An Baigang , Geng Xin , Sun Chengguo
Published: March 2023

Lithium (Li) metal is a highly desirable anode for all‐solid‐state lithium‐ion batteries (ASSLBs) due to its high theoretical capacity and being well matched with solid‐state electrolytes. However, the practical applications of Li metal anode are hindered by the uneven Li metal plating/stripping behavior and poor contact between electrolyte and Li anode. Herein, a convenient and efficient strategy to construct the Li3N‐based interlayer between solid poly(ethylene oxide) (PEO) electrolyte and Li anode is proposed by in situ thermal decomposition of 2,2′‐azobisisobutyronitrile (AIBN) additive. The evolved Li3N nanoparticles are capable of combining LiF, cyano derivatives and PEO electrolyte to form a buffer layer of about 0.9 μm during the cell cycle, which can buffer Li+ concentration and homogenize Li deposition. The Li||Li symmetric cells with Li3N‐based interlayer show excellent cycle stability at 0.2 mA cm−2, which is at least 4 times longer cycle life than that of PEO electrolytes without Li3N layer. This work provides a convenient strategy for designing interface engineering between solid‐state polymer electrolyte and Li anode.
Long‐term exclusion of invasive ungulates alters tree recruitment and functional traits but not total forest carbon
Authors: Allen Kara , Bellingham Peter J. , Richardson Sarah J. , Allen Robert B. , Burrows Larry E. , Carswell Fiona E. , Husheer Sean W. , St. John Mark G. , Peltzer Duane A.
Published: March 2023

Forests are major carbon (C) sinks, but their ability to sequester C and thus mitigate climate change, varies with the environment, disturbance regime, and biotic interactions. Herbivory by invasive, nonnative ungulates can have profound ecosystem effects, yet its consequences for forest C stocks remain poorly understood. We determined the impact of invasive ungulates on C pools, both above‐ and belowground (to 30 cm), and on forest structure and diversity using 26 paired long‐term (>20 years) ungulate exclosures and adjacent unfenced control plots located in native temperate rainforests across New Zealand, spanning 36–41° S. Total ecosystem C was similar between ungulate exclosure (299.93 ± 25.94 Mg C ha−1) and unfenced control (324.60 ± 38.39 Mg C ha−1) plots. Most (60%) variation in total ecosystem C was explained by the biomass of the largest tree (mean diameter at breast height [dbh]: 88 cm) within each plot. Ungulate exclusion increased the abundance and diversity of saplings and small trees (dbh ≥2.5, <10 cm) compared with unfenced controls, but these accounted for ~5% of total ecosystem C, demonstrating that a few, large trees dominate the total forest ecosystem C but are unaffected by invasive ungulates at a timescale of 20–50 years. However, changes in understory C pools, species composition, and functional diversity did occur following long‐term ungulate exclusion. Our findings suggest that, although the removal of invasive herbivores may not affect total forest C at the decadal scale, major shifts in the diversity and composition of regenerating species will have longer term consequences for ecosystem processes and forest C.
Developing the “single‐session mindset” in eating disorder research: Commentary on Schleider et al., 2023 “Realizing the untapped promise of single‐session interventions for eating disorders”
Authors: Wade Tracey D.
Published: March 2023

Schleider and colleagues' paper on the application of single‐session interventions (SSIs) to eating disorders is timely given the broader focus in mental health on flexible approaches to delivering support at the time the person needs it most. The eating disorder field needs to embrace these innovations including developing a “single‐session mindset” with greater attention paid to testing the relevance of SSI for eating disorders. The use of well‐powered trials of brief, focused and rapidly scalable interventions is an ideal vehicle for generation and evaluation of new and longer interventions. Our future research agenda needs to carefully consider our target audience, the primary outcome variable of most relevance, and the SSI topic that would be most likely to effect change. Research in prevention might focus on weight concern and evaluation of SSIs that focus on self‐compassion or cognitive dissonance related to appearance ideals in the media. Work in early intervention could target denial and disordered eating using SSIs on growth mindset, behavioral activation, and imagery rescripting. Treatment waitlists provide another suitable opportunity, evaluating SSIs that aim to increase hope for change, treatment retention, and kick start early change in therapy, a robust predictor of better treatment outcome.
Cascading impacts of changes in subsidy quality on recipient ecosystem functioning
Authors: Osakpolor Stephen E. , Manfrin Alessandro , Leroux Shawn J. , Schäfer Ralf B.
Published: March 2023

Resource quantity and quality can differ between adjacent ecosystems, and these differences can impact subsidies exchanged between ecosystems. The quantity and quality of subsidies are rapidly changing in response to stressors associated with global environmental change, but while we have models to predict the effects of changes in subsidy quantity, we currently lack models to predict the effects of changes in subsidy quality on recipient ecosystem functioning. We developed a novel model to predict the effects of subsidy quality on recipient ecosystem biomass distribution, recycling, production, and efficiency. We parameterized the model for a case study of a riparian ecosystem subsidized by pulsed emergent aquatic insects. In this case study we focused on a common measure of subsidy quality that differs between riparian and aquatic ecosystems: the higher content of long‐chain polyunsaturated fatty acids (PUFAs) in aquatic ecosystems. We analyzed how changes in the PUFA concentration of aquatic subsidies affect the dynamics in biomass stocks and functions of the riparian ecosystem. We also conducted a global sensitivity analysis to identify key drivers of subsidy impacts. Our analysis showed that subsidy quality increased the functioning of the recipient ecosystem. Recycling increased more strongly than production per unit subsidy quality increase, meaning there was a threshold where an increase in subsidy quality led to stronger effects of subsidies on recycling relative to the production of the recipient ecosystem. Our predictions were most sensitive to basal nutrient input, highlighting the relevance of recipient ecosystem nutrient levels to understanding the effects of ecosystem connections. We argue that recipient ecosystems that rely on high‐quality subsidies, such as aquatic–terrestrial ecotones, are highly sensitive to changes in subsidy–recipient ecosystem connections. Our novel model unifies the subsidy hypothesis and food quality hypothesis and provides testable predictions to understand the effects of ecosystem connections on ecosystem functioning under global changes.
Magnesium Complexes Supported by 6,6’‐Dimethylbiphenyl‐Bridged Salen Ligands: Synthesis, Characterization and Catalysis for rac‐Lactide Polymerization
Authors: Chen Ruyi , Ma Haiyan
Published: March 2023

A series of racemic 6,6’‐[(6,6’‐dimethyl‐[1,1’‐biphenyl]‐2,2’‐diyl)bis(nitrylomethilidyne)]‐bis(2‐R1‐4‐R2‐phenol) proligands (L1H2, R1=R2=Me; L2H2, R1=tBu, R2=Me; L3H2, R1=R2=cumyl; L4H2, R1=CPh3, R2=Me) were reacted with {Mg[N(SiMe3)2]2}2 to provide mononuclear and dinuclear magnesium complexes [L12Mg2] (1), L2–4Mg (2–4), {L1–3[MgN(SiMe3)2]2} (5–7). Complexes 3* and 4* in which each metal center is coordinated with a THF molecule were obtained when the corresponding crude complexes were recrystallized with a mixture of THF and n‐hexane. Similarly, the formation of THF coordinated structure 7* of the heteroleptic dinuclear complex 7 was identified. The molecular structures of complexes 3*, 6 and 7* were established by X‐ray single crystal diffraction studies, which show that mononuclear complex 3* possesses a five‐coordinated metal center adopting a distorted square pyramid configuration, the two metal centers of the dinuclear complex 6 are bridged by two phenoxy oxygen atoms and each has a four‐coordinated distorted tetrahedral configuration, and each metal center of the dinuclear complex 7* is still four‐coordinated upon the coordination of THF but without bridging to each other. All complexes were investigated for the ring‐opening polymerization (ROP) of rac‐lactide (rac‐LA) at 60 °C in toluene or tetrahydrofuran. Compared with the mononuclear counterparts, the dinuclear magnesium silylamido complexes showed significantly higher activities.
Complexes of Fe(III) and Ga(III) Derived from the Cyclic 6‐ and 7‐Membered Hydroxamic Acids Found in Mixed Siderophores
Authors: Jewula Pawel , Grandmougin Mickaël , Choppin Mélanie , Tivelli Anna Maria Chiara , Amati Agnese , Rousselin Yoann , Karmazin Lydia , Chambron Jean‐Claude , Meyer Michel
Published: March 2023

Six‐ and seven‐membered cyclic hydroxamic acids are found as terminal binding units in different families of siderophores, including exochelins and mycobactins. The simplest models of these preorganized chelating ligands were known, but their coordination chemistry with Fe3+, the target metal ion of siderophores, had never been reported. Four complexes were synthesized and studied: two Fe3+ complexes, one with the six‐membered ring hydroxamate PIPO− and one with the seven‐membered ring hydroxamate AZEPO−, and the two corresponding Ga3+ complexes. X‐ray diffraction studies showed that the interligand repulsion energies were better minimized in the case of the AZEPO− complexes whatever the metal cation considered, and that the Fe−O bond distances were shorter in [Fe(AZEPO)3] by comparison with [Fe(PIPO)3].
Synthesis of the N‐Amykitanosyl Tetramic Acid Moiety of Amycolamicin
Authors: Meguro Yasuhiro , Enomoto Masaru , Kuwahara Shigefumi
Published: March 2023

An improved five‐step synthetic route from l‐fucose to an N‐glycosyl l‐valine methyl ester has been developed. The new route involves glycosidation of l‐fucose with phenol in a β‐selective manner without protection/deprotection steps and one‐pot stereochemical inversion of a secondary alcohol intermediate and is superior to our previous one both in the number of steps and in overall yield. An N‐glycosyl l‐valine benzyl ester, prepared from l‐fucose in an analogous way, has been elaborated into an N‐amykitanosyl tetramic acid derivative, Li's synthetic intermediate for amycolamicin, via a four‐step sequence which features the utilization of Bestmann's ylide to stereoconvergently construct an N‐glycosyl tetramic acid intermediate in a single step, opening of a cyclic carbonate ring with an amine to regioselectively install a carbamate functionality, and visible light‐mediated oxidative debenzylation of an N,N‐dibenzyl carbamate.
Pd/Ni Co‐catalyzed Selective Cross‐Coupling of Aryl Bromides and Aryl Fluorosulfonates at Room Temperature
Authors: Zhang Guofu , Luo Xuefei , Guan Chenfei , Cui Yin , Ding Chengrong
Published: March 2023

Multimetallic catalysis can effectively enhance the selectivity for the heterocoupling product over homocoupling products in cross‐electrophilic couplings. We report the selective cross‐coupling of aryl bromides with aryl fluorosulfonates via palladium and nickel cooperative catalysis for the synthesis of biaryls, which can be carried out at room temperature while having marvelous chemoselectivity. In addition, the reaction also has a good performance on the gram‐scale reaction.
Site‐directed mutagenesis improves the practical application of L‐glutamic acid decarboxylase inEscherichia coli
Authors: Fengmin Liu , Heng Zhang , Xiangjun Zhang , Xiaobo Wei , Huiyan Liu , Haitian Fang
Published: March 2023

γ‐Aminobutyric acid (GABA) is a kind of non‐proteinogenic amino acid which is highly soluble in water and widely used in the food and pharmaceutical industries. Enzymatic conversion is an efficient method to produce GABA, whereby glutamic acid decarboxylase (GAD) is the key enzyme that catalyzes the process. The activity of wild‐type GAD is usually limited by temperature, pH or biotin concentration, and hence directional modification is applied to improve its catalytic properties and practical application. GABA was produced using whole cell transformation of the recombinant strainsEscherichia coliBL21(DE3)‐Gad B,E. coliBL21(DE3)‐Gad B‐T62S andE. coliBL21(DE3)‐Gad B‐Q309A. The corresponding GABA concentrations in the fermentation broth were 219.09, 238.42, and 276.66 g/L, and the transformation rates were 78.02%, 85.04%, and 98.58%, respectively. The results showed that Gad B‐T62S and Gad B‐Q309A are two effective mutation sites. These findings may contribute to ideas for constructing potent recombinant strains for GABA production.

Practical Application: Enzymatic properties of the GAD fromEscherichia coliand GAD site‐specific mutants were examined by analyzing their conserved sequences, substrate contacts, contact between GAD amino acid residues and mutation energy (ΔΔG) of the GAD mutants. The enzyme activity and stability of Gad B‐T62S and Gad B‐Q309A mutants were improved compared to Gad B. The kinetic parameters Kmand Vmaxof Gad B, Gad B‐T62S, and Gad B‐Q309A mutants were 11.3 ± 2.1 mM and 32.1 ± 2.4 U/mg, 7.3 ± 2.5 mM and 76.1 ± 3.1 U/mg, and 7.2 ± 3.8 mM and 87.3 ± 1.1 U/mg, respectively. GABA was produced using whole cell transformation of the recombinant strainsE. coliBL21(DE3)‐Gad B,E. coliBL21(DE3)‐Gad B‐T62S, andE. coliBL21(DE3)‐Gad B‐Q309A. The corresponding GABA concentrations in the fermentation broth were 219.09, 238.42, and 276.66 g/L, and the transformation rates were 78.02%, 85.04%, and 98.58%, respectively.
Applications of artificial neural networks for calculation of the Erlang B formula and its inverses
Authors: Marinković Zlatica , Stošić Biljana P.
Published: March 2023

In this article, a novel approach to calculate the Erlang B formula and its inverses is proposed. It is based on application of artificial neural networks (ANNs). Namely, ANNs are trained to calculate the Erlang B call blocking probability as well as to solve the inverse problem, i.e. to calculate the required number of channels or the maximum amount of traffic for the given call blocking probability. Comparing to direct calculation of Erlang B formula, computational efficiency is significantly increased, while the accuracy is maintained. As far as the calculation of Erlang B inverse values is considered, as there is a lack of exact mathematical formulas, the proposed approach provides the closed‐form mathematical expressions.
Portable Photovoltaic Power Generation System for Applications along the Railway and Its Improved Efficiency by Automatic Dust Removal by Foldable Solar Energy Collector
Authors: Sun Zhengcheng , Lu Linhai , Li Dongyang , Hao Daning , Zhang Zutao , Wu Xiaoping , Kong Lingji , Lyu Xiaoqin
Published: March 2023

To meet the demands of power supply for applications along the railway in treacherous terrain, this article proposes a portable photovoltaic power generation system (PVPGS) based on a foldable mechanism for applications along the railway. First, the designed system mainly consists of a foldable solar energy collector (FSEC) and an energy conduit. Dust deposited on the photovoltaic panels is reduced while the FSEC is being folded or unfolded. Moreover, the characteristics of dust particles, effects of natural dust on photovoltaic glass transmittance, and power of portable PVPGS are investigated. In addition, the mechanism on improving the power generation efficiency of PVPGS is analyzed. The results demonstrate that the designed foldable mechanism can contain the dust deposition on photovoltaic power loss within 4%. Finally, Chengdu city and Sichuan–Tibet Railway are selected for an application prospect, and the results show that the average annual power generation of one portable PVPGS can reach up to 16.7 kWh, which is enough to power sensors and other applications along the railway. Simulations, theoretical analyses, and experiments confirm the feasibility of using the proposed portable PVPGS to power applications along the railway.
Effects ofPoria cocosextract and protein powder mixture on glucolipid metabolism and rhythm changes in obese mice
Authors: Xie Qiaoling , Jia Xiuzhen , Zhang Wei , Xu Yuhan , Zhu Meizhen , Zhao Zifu , Hao Jingyu , Li Haoqiu , Du Jinrui , Liu Yan , Feng Haotian , Li Hongwei
Published: March 2023

Herein, we explored the effects ofPoria cocosextract, protein powder mixture, and their combined intervention on weight loss in high‐fat diet (HFD)‐induced obese mice. Male C57BL/6J mice were selected and fed a HFD for 8 weeks; obese mice that were successfully modeled were divided into modeling and five intervention groups, and given the corresponding treatment for 10 weeks. Body weight, fat, and muscle tissue, blood glucose, lipids, inflammatory factors, and other glucose and lipid metabolism‐related indicators were measured to evaluate the effect ofP. cocosand protein powder intervention on weight loss in obese mice. The body weight of the intervention group was reduced compared with the HFD group. Fat content of mice in F3PM group decreased significantly (p < .05). Levels of blood glucose, lipids, adiponectin, leptin, and inflammatory factors, including interleukin‐1 β and tumor necrosis factor‐ α showed improvement. Lipoprotein lipase (lower about 2.97 pg/ml, vs. HFD mice 10.65 mmoL/ml) and sterol regulatory element‐binding transcription factor (lower about 1413.63 pg/ml, vs. HFD mice 3915.33 pg/ml) levels in liver tissue were decreased. The respiratory exchange rate (RER) of mice in the HFD and subject intervention groups had no circadian rhythm and was maintained at approximately 0.80. The protein powder mixture (PM) group had the lowest RER (p < .05), theP. cocosextract (FL) and F1PM groups had similar RER to the HFD group (p < .05), and the F2PM group had a higher RER than the HFD group (p < .05). And food intake and energy metabolism returned to circadian rhythm, with an increase in the dose ofP. cocosextract, the feeding rhythms of F1PM, F2PM, and F3PM were closer to that of the normal diet (ND) group. Feeding intervention withP. cocosand protein powder improved fat distribution, glucolipid metabolism, and energy metabolism, with the combination of F3PM showing more diverse benefits.
Effect on Ziziphus jujuba Mill. fruit powders embedded on physicochemical properties, biological activities, and rheologic quality of cake
Authors: Elaloui Meriem , Ammari Youssef , Ghazghazi Hanen , Gorrab Afwa Ep Ben Othmen , Laamouri Abdelwahed , Driouich Chaouachi Rim
Published: March 2023

This study aimed to improve the effects on the physical, textural, and rheological characteristics of cake supplied with Ziziphus jujuba fruit powder at rates of 0%, 3%, 5%, and 10%. The Physicochemical and antioxidant as well as the antibacterial activity and sensory qualities of Z. jujuba fruits were also investigated. The highest levels reached the values of 245.15 mg GAE/g DW (phenol) and 180.23 mg RE/g DW (flavonoids). Pulp extracts were also subjected to HPLC analysis in order to identify and quantify the sugar composition. This technique allowed us to identify Mahdia as the richest provenance especially in glucose (136.51%) and sucrose (113.28%) contents. The antioxidant activities investigated using DPPH assay decreased slightly from 175 μg/mL (Sfax) to 55 μg/mL (Mahdia). Furthermore, the antibacterial activity indicated that the S. aureus was the most inhibited especially by Sfax powder extracts (from 12 to 20 mm). Our results showed that the incorporation of Z. jujuba powder ameliorated the physicochemical and rheological characteristics (humidity, gluten yield, tenacity, falling time, and configuration) of the dough. Sensory analysis showed that consumer scores were increased with the increasing supplementation powder levels. Highest scores attributed to the cake supplied with 3% jujube powder collected from Mahdia provenance and confirmed that Ziziphus fruit could be advised a part of our diet. These results could validate a novel method to conserve Z. jujuba fruits in order to avoid their soilages for a long period.
Geochronology, geochemistry and Hf isotopic compositions of late Silurian granodiorites in the Shaolang River metallogenic belt: Implications for magmatism and tectonic evolution
Authors: Wang Chun‐Guang , Liu Jie‐Xun , Gu Zhong‐Yuan , Liu Xin‐Yue , Yang Yang , Sun Guo‐Sheng
Published: March 2023

The Shaolang River metallogenic belt in Inner Mongolia is one of the main lead‐zinc polymetallic belt on the northern margin of the North China Plate. The granodiorites, which are closely coexisting with lead‐zinc veins in deposit, are extensively developed. Previous geochronological research results show that the dikes and veins in the metallogenic belt belong to the products of magmatic hydrothermal activity in the middle Yanshanian, so the genesis of the metallogenic belt deposit is generally considered to be a hydrothermal vein type deposit related to sub‐volcanic dikes. We obtained zircon LA‐ICP‐MS U–Pb ages and Hf isotopic compositions of granodiorites, which are widely distributed in the deposit and were considered to be closely connected with the genesis of the deposits. The zircon U–Pb ages are 419.4 ± 1.4 Ma and 424.5 ± 4.1 Ma for the granodiorites, respectively, and they formed in the late Silurian. The geological and geochemical data indicate that the granodiorites are consistent with the geochemical characteristics of typical adakite. All εHf(t) values of the granodiorites are minus, on the zircon Hf isotope age diagram, εHf(t) are below the evolution curve of chondrite. The two‐stage model ages (tDM2) are 2.45 ~ 2.79 Ga and 1.87 ~ 2.29 Ga, respectively, showing rock‐forming materials mainly derived from the Paleoproterozoic and earlier crustal partial melting, and there may have been mantle‐derived magma underplating of the lower crust. Combining with the previous regional research, it is concluded that the granodiorites were formed during the extinction of the island arc under the background of subduction of the Paleo‐Asian Ocean and North China Craton. Because of the 125 ~ 170 Ma metallogenic age, we concluded that the granodiorites in the ore areas have no obvious relationship with the deposit genesis. However, it provided the advantageous space for the formation of the lead‐zinc veins, it can be regarded as an important prospecting indicator in metallogenic belt.
Community centers for older adults and psychosocial factors: Evidence from the German Ageing Survey
Authors: Hajek André , Kretzler Benedikt , Gyasi Razak M. , König Hans‐Helmut
Published: March 2023

Introduction

There is a dearth of studies examining the association between the use of community centers for older adults and psychosocial factors. Thus, our aim was to examine the association between the use of community centers for older adults and psychosocial factors (in terms of loneliness, perceived social isolation, and life satisfaction; also stratified by sex)—which is important for successful aging.

Methods/Design

Data were taken from a nationally representative sample—the German Ageing Survey—including older community‐dwelling individuals. The De Jong Gierveld tool was used to measure loneliness, the Bude and Lantermann tool was used to measure perceived social isolation, and the Satisfaction with Life Scale was used to quantify life satisfaction. Multiple linear regressions were used to evaluate the hypothesized associations.

Results

In the analytical sample, n equaled 3246 individuals (mean age was 75 years, 65–97 years). After adjusting for various socioeconomic, lifestyle‐related, and health‐related covariates, multiple linear regressions showed that the use of community centers was associated with higher life satisfaction among men (β = 0.12, p < 0.01), but not women. The use of community centers was not associated with loneliness or perceived social isolation for either gender.

Conclusions

The use of community centers was positively associated with satisfaction with one's own life among male older adults. Thus, encouraging older men to use such services may be beneficial. This quantitative study provides an initial basis for further research in this neglected area. For example, longitudinal studies are required to confirm our present findings.
Stratification of surgical margin distances by the millimeter on local recurrence in oral cavity cancer: A systematic review and meta‐analysis
Authors: Young Kurtis , Bulosan Hannah , Kida Carley C. , Bewley Arnaud F. , Abouyared Marianne , Birkeland Andrew C.
Published: March 2023

There are limited data supporting the commonly suggested 5 mm margin cutoff as the optimum value in defining clear margins in oral cancer. A database search of Pubmed/Medline, Web of Science, and EBSCOhost was performed from inception to June 2022. A random‐effects model was chosen for this meta‐analysis. The Preferred Reporting Items for Systematic Reviews and Meta‐analyses (PRISMA) guidelines were followed throughout this study. Seven studies met study criteria (2215 patients). The risk ratio was significantly higher for margins <5 mm when compared to those ≥5 mm (2.09 (95%CI: 1.53–2.86, I2 = 0.47)). Subgroup analysis (I2 = 0.15) of margin distances of 0.0–0.9, 1.0–1.9, 2.0–2.9, 3.0–3.9, and 4.0–4.9 mm calculated risk ratios for local recurrence of 2.96, 2.01, 2.17, 1.8, and 0.98, respectively. Margins between 4.0 and 4.9 mm had similar risk ratios for local recurrence compared to ≥5 mm, while margins <4.0 were significantly higher.
EGFR is a potential therapeutic target for highly glycosylated and aggressive pancreatic neuroendocrine neoplasms
Authors: Xiao Zhiwen , Xu Huaxiang , Strosberg Jonathan R. , Lu Renquan , Zhu Xinzhe , Deng Shengming , Ding Lei , Ni Quanxing , Warshaw Andrew L. , Yu Xianjun , Luo Guopei
Published: March 2023

pNENs are relative indolent tumors with heterogeneous clinical presentation at diagnosis. It is important to establish aggressive subgroups of pNENs and identify potential therapeutic targets. Patients with pNEN (322 cases) were included to examine the association between glycosylation biomarkers and clinical/pathological traits. The molecular and metabolic features stratified by glycosylation status were assessed by RNA‐seq/whole exome sequencing and immunohistochemistry. A considerable proportion of patients had elevated glycosylation biomarkers (carbohydrate antigen [CA] 19‐9, 11.9%; CA125, 7.5%; carcinoembryonic antigen [CEA], 12.8%). CA19‐9 (hazard ratio [HR] = 2.26, P = .019), CA125 (HR = 3.79, P = .004) and CEA (HR = 3.16, P = .002) were each independent prognostic variables for overall survival. High glycosylation group, defined as pNENs with elevated level of circulating CA19‐9, CA125 or CEA, accounted for 23.4% of all pNENs. High glycosylation (HR = 3.14, P = .001) was an independent prognostic variable for overall survival and correlated with G3 grade (P < .001), poor differentiation (P = .001), perineural invasion (P = .004) and distant metastasis (P < .001). Epidermal growth factor receptor (EGFR) was enriched in high glycosylation pNENs using RNA‐seq. EGFR was expressed in 21.2% of pNENs using immunohistochemistry and associated with poor overall survival (P = .020). A clinical trial focusing on EGFR expressed pNENs was initiated (NCT05316480). Thus, pNEN with aberrant glycosylation correlates with a dismal outcome and suggests potential therapeutic target of EGFR.
Inventory overproduction and managerial ability
Authors: He Haihong
Published: March 2023

This study examines a sample of manufacturing firms in order to assess the relationship between overproduction levels with different levels of managerial ability. Using the managerial ability measure developed by Demerjian et al. (2012), this paper shows that firms with high levels of managerial ability have smaller size of overproduction. Furthermore, when overproduction occurs in firms with high levels of managerial ability, it is less likely to reverse in the following year and is more likely to be associated with future sales increases. Overall, the results suggest that high managerial ability firms generally avoid overproduction. High‐ability managers having fewer overproduction reversals suggest that they are less likely to use overproduction to manage earnings; instead, they are more likely to overproduce to build up inventory to expect higher future sales.
A review of the signaling pathways of aerobic and anaerobic exercise on atherosclerosis
Authors: Liu Sibo , Liu Yuhe , Liu Zhihan , Hu Yansong , Jiang Meixiu
Published: March 2023

Atherosclerosis (AS), a chronic inflammatory vascular disease with lipid metabolism abnormalities, is one of the major pathological bases of coronary heart disease. As people's lifestyles and diets change, the incidence of AS increases yearly. Physical activity and exercise training have recently been identified as effective strategies for lowering cardiovascular disease (CVD) risk. However, the best exercise mode to ameliorate the risk factors related to AS is not clear. The effect of exercise on AS is affected by the type of exercise, intensity, and duration. In particular, aerobic and anaerobic exercise are the two most widely discussed types of exercise. During exercise, the cardiovascular system undergoes physiological changes via various signaling pathways. The review aims to summarize signaling pathways related to AS in two different exercise types and provide new ideas for the prevention and treatment of AS in clinical practice.
Ultrasound‐based measures in carpal tunnel syndrome: What to measure?
Authors: Akpan Eyerusalem B. , Nunez Sharon E. , Sibbitt Wilmer L.
Published: March 2023

Carpal tunnel syndrome (CTS) is the most common peripheral entrapment neuropathy and is caused by compression of the median nerve (MN) at the level of transverse carpal ligament of the volar wrist. Radiomics is an advanced semi‐automated image analysis method that is utilized to identify characteristics in the MN that can detect CTS with considerable reproducibility.
Weak degeneracy of graphs
Authors: Bernshteyn Anton , Lee Eugene
Published: March 2023

Motivated by the study of greedy algorithms for graph coloring, we introduce a new graph parameter, which we call weak degeneracy. By definition, every ‐degenerate graph is also weakly ‐degenerate. On the other hand, if is weakly ‐degenerate, then (and, moreover, the same bound holds for the list‐chromatic and even the DP‐chromatic number of ). It turns out that several upper bounds in graph coloring theory can be phrased in terms of weak degeneracy. For example, we show that planar graphs are weakly 4‐degenerate, which implies Thomassen's famous theorem that planar graphs are 5‐list‐colorable. We also prove a version of Brooks's theorem for weak degeneracy: a connected graph of maximum degree is weakly ‐degenerate unless . (By contrast, all ‐regular graphs have degeneracy .) We actually prove an even stronger result, namely that for every , there is such that if is a graph of weak degeneracy at least , then either contains a ‐clique or the maximum average degree of is at least . Finally, we show that graphs of maximum degree and either of girth at least 5 or of bounded chromatic number are weakly ‐degenerate, which is best possible up to the value of the implied constant.