bluuebunny/crossref_metadata_2025 huggingface dataset:
Metabolic Control During Macrophage Polarization by a Citrate‐Functionalized Scaffold for Maintaining Bone Homeostasis
Authors: Wu Xiaopei , Xia Yuhao , Dai Honglian , Hong Chuhang , Zhao Yanan , Wei Wenying , Zheng Dian
Published: April 2024

Metabolites, as markers of phenotype at the molecular level, can regulate the function of DNA, RNA, and proteins through chemical modifications or interactions with large molecules. Citrate is an important metabolite that affects macrophage polarization and osteoporotic bone function. Therefore, a better understanding of the precise effect of citrate on macrophage polarization may provide an effective alternative strategy to reverse osteoporotic bone metabolism. In this study, a citrate functional scaffold to control the metabolic pathway during macrophage polarization based on the metabolic differences between pro‐inflammatory and anti‐inflammatory phenotypes for maintaining bone homeostasis, is fabricated. Mechanistically, only outside M1 macrophages are accumulated high concentrations of citrate, in contrast, M2 macrophages consume massive citrate. Therefore, citrate‐functionalized scaffolds exert more sensitive inhibitory effects on metabolic enzyme activity during M1 macrophage polarization than M2 macrophage polarization. Citrate can block glycolysis‐related enzymes by occupying the binding‐site and ensure sufficient metabolic flux in the TCA cycle, so as to turn the metabolism of macrophages to oxidative phosphorylation of M2 macrophage, largely maintaining bone homeostasis. These studies indicate that exogenous citrate can realize metabolic control of macrophage polarization for maintaining bone homeostasis in osteoporosis.
First‐Principles Investigations on Effects of B‐Site Substitution (B═Mn, Fe, and Co) on La‐Based Perovskite Oxides As Bifunctional Electrocatalysts for Rechargeable Metal–Air Batteries
Authors: Somdee Siriwimol , Rittiruam Meena , Saelee Tinnakorn , Khajondetchairit Patcharaporn , Ektarawong Annop , Kheawhom Soorathep , Alling Björn , Praserthdam Piyasan , Praserthdam Supareak
Published: April 2024

The effects of B‐site substitution (B═Mn, Fe, and Co) in La‐based perovskite oxides (LPOs); LaMnO3, LaFeO3, LaCoO3, as bifunctional electrocatalysts during oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in metal–air batteries (MABs) under an alkaline electrolyte (pH = 13) are investigated using density functional theory (DFT). It is found that LaMnO3 exhibits higher ORR activity than others with ORR overpotential (ηORR) of 0.57 V, but its OER activity is poor with OER overpotential (ηOER) of 1.12 V. The ηORR (0.59 V) and ηOER (1.13 V) of LaMn0.75Fe0.25O3 closely resemble those of LaMnO3, suggesting that Fe substitution does not yield appreciable enhancements in activity. Fe substitution reduces the ORR and OER activity because the adsorption energies of intermediate species on Fe‐substituted LPOs surfaces are too strong to obtain a potential determining step for ORR and OER. According to Sabatier's principle, the LaMn0.25Co0.75O3 demonstrates superior OER activity compared to the other composition, while ORR activity approximates that of LaMnO3, evidenced by ηORR of 0.65 V and ηOER of 0.53 V. The Co‐terminated LaMn0.25Co0.75O3 shows bifunctional activity higher than Mn/Co termination, indicating that Co is an active site for OER and Mn is a promoter for improved ORR activity.
Surviving the Storm: The Role of Poly‐ and Depolyploidization in Tissues and Tumors
Authors: Zhao Yucui , He Sijia , Zhao Minghui , Huang Qian
Published: April 2024

Polyploidization and depolyploidization are critical processes in the normal development and tissue homeostasis of diploid organisms. Recent investigations have revealed that polyaneuploid cancer cells (PACCs) exploit this ploidy variation as a survival strategy against anticancer treatment and for the repopulation of tumors. Unscheduled polyploidization and chromosomal instability in PACCs enhance malignancy and treatment resistance. However, their inability to undergo mitosis causes catastrophic cellular death in most PACCs. Adaptive ploid reversal mechanisms, such as multipolar mitosis, centrosome clustering, meiosis‐like division, and amitosis, counteract this lethal outcome and drive cancer relapse. The purpose of this work is to focus on PACCs induced by cytotoxic therapy, highlighting the latest discoveries in ploidy dynamics in physiological and pathological contexts. Specifically, by emphasizing the role of “poly‐depolyploidization” in tumor progression, the aim is to identify novel therapeutic targets or paradigms for combating diseases associated with aberrant ploidies.
Loss of OVOL2 in Triple‐Negative Breast Cancer Promotes Fatty Acid Oxidation Fueling Stemness Characteristics
Authors: Lu Ruipeng , Hong Jingjing , Fu Tong , Zhu Yu , Tong Ruiqi , Ai Di , Wang Shuai , Huang Qingsong , Chen Ceshi , Zhang Zhiming , Zhang Rui , Guo Huiling , Li Boan
Published: April 2024

Triple‐negative breast cancer (TNBC), the most aggressive subtype of breast cancer, has a poor prognosis and lacks effective treatment strategies. Here, the study discovered that TNBC shows a decreased expression of epithelial transcription factor ovo‐like 2 (OVOL2). The loss of OVOL2 promotes fatty acid oxidation (FAO), providing additional energy and NADPH to sustain stemness characteristics, including sphere‐forming capacity and tumor initiation. Mechanistically, OVOL2 not only suppressed STAT3 phosphorylation by directly inhibiting JAK transcription but also recruited histone deacetylase 1 (HDAC1) to STAT3, thereby reducing the transcriptional activation of downstream genes carnitine palmitoyltransferase1 (CPT1A and CPT1B). PyVT‐Ovol2 knockout mice develop a higher number of primary breast tumors with accelerated growth and increased lung‐metastases. Furthermore, treatment with FAO inhibitors effectively reduces stemness characteristics of tumor cells, breast tumor initiation, and metastasis, especially in OVOL2‐deficient breast tumors. The findings suggest that targeting JAK/STAT3 pathway and FAO is a promising therapeutic strategy for OVOL2‐deficient TNBC.
Dynamic Reconfiguration and Local Polarization of NiFe‐Layered Double Hydroxide‐Bi2MoO6−x Heterojunction for Enhancing Piezo‐Photocatalytic Nitrogen Oxidation to Nitric Acid
Authors: Deng Xiaoxu , Chen Peng , Cui Ruirui , Gong Xingyong , Wu Yubo , Wang Xu , Deng Chaoyong
Published: April 2024

Constructing heterojunctions with vacancies has garnered substantial attention in the field of piezo‐photocatalysis. However, the presence of interfacial vacancies can serve as charge‐trapping sites, leading to the localization of electrons and hindering interfacial charge transfer. Herein, dual oxygen vacancies in the NiFe‐layered double hydroxide and Bi2MoO6−x induced interfacial bonds have been designed for the piezo‐photocatalytic N2 oxidation to NO3−. Fortunately, it achieves sensational nitric acid production rates (7.23 mg g−1 h−1) in the absence of cocatalysts and sacrificial agents, which is 6.03 times of pure Bi2MoO6 that under ultrasound and light illumination. Theoretical and experimental results indicate that interfacial bonds act as “charge bridge” and “strain center” to break the carrier local effect and negative effects with piezocatalysis and photocatalysis for promoting exciton dissociation and charge transfer. Moreover, the strong electronic interaction of the interfacial bond induces internal reconstruction under ultrasound for promoting the local polarization and adsorption of N2, which accelerates the fracture of the N≡N bonds and reduces the activation energy of the reaction. The research not only establishes a novel approach for optimizing the combined effects of piezo‐catalysis and photocatalysis, but also achieves equilibrium between the synergistic impacts of vacancies and heterojunctions.
Secondary Structure in Enzyme‐Inspired Polymer Catalysts Impacts Water Oxidation Efficiency
Authors: Sedenho Graziela C. , Nascimento Steffane Q. , Zamani Marjon , Crespilho Frank N. , Furst Ariel L.
Published: April 2024

Protein structure plays an essential role on their stability, functionality, and catalytic activity. In this work, the interplay between the β‐sheet structure and its catalytic implications to the design of enzyme‐inspired materials is investigated. Here, inspiration is drawn from the active sites and β‐sheet rich structure of the highly efficient multicopper oxidase (MCO) to engineer a bio‐inspired electrocatalyst for water oxidation utilizing the abundant metal, copper. Copper ions are coordinated to poly‐histidine (polyCuHis), as they are in MCO active sites. The resultant polyCuHis material effectively promotes water oxidation with low overpotentials (0.15 V) in alkaline systems. This activity is due to the 3D structure of the poly‐histidine backbone. By increasing the prevalence of β‐sheet structure and decreasing the random coil nature of the polyCuHis secondary structures, this study is able to modulates the electrocatalytic activity of this material is modulated, shifting it toward water oxidation. These results highlight the crucial role of the local environment at catalytic sites for efficient, energy‐relevant transformations. Moreover, this work highlights the importance of conformational structure in the design of scaffolds for high‐performance electrocatalysts.
Self‐Sacrificial Template Synthesis of Fe‐N‐C Catalysts with Dense Active Sites Deposited on A Porous Carbon Network for High Performance in PEMFC
Authors: Jiao Li , Arman Tanvir Alam , Hwang Sooyeon , Fonseca Javier , Okolie Norbert , Shaaban Ehab , Li Gonghu , Liu Ershuai , Pasaogullari Ugur , Babu Siddharth Komini , Mukerjee Sanjeev , Spendelow Jacob Schatz , Cullen David A. , Jaouen Frédéric , Jia Qingying
Published: April 2024

Iron‐nitrogen‐carbon (Fe‐N‐C) single‐atom catalysts are promising sustainable alternatives to the costly and scarce platinum (Pt) to catalyze the oxygen reduction reactions (ORR) at the cathode of proton exchange membrane fuel cells (PEMFCs). However, Fe‐N‐C cathodes for PEMFC are made thicker than Pt/C ones, in order to compensate for the lower intrinsic ORR activity and site density of Fe‐N‐C materials. The thick electrodes are bound with mass transport issues that limit their performance at high current densities, especially in H2/air PEMFCs. Practical Fe‐N‐C electrodes must combine high intrinsic ORR activity, high site density, and fast mass transport. Herein, it has achieved an improved combination of these properties with a Fe‐N‐C catalyst prepared via a two‐step synthesis approach, constructing first a porous zinc‐nitrogen‐carbon (Zn‐N‐C) substrate, followed by transmetallating Zn by Fe via chemical vapor deposition. A cathode comprising this Fe‐N‐C catalyst has exhibited a maximum power density of 0.53 W cm−2 in H2/air PEMFC at 80 °C. The improved power density is associated with the hierarchical porosity of the Zn‐N‐C substrate of this work, which is achieved by epitaxial growth of ZIF‐8 onto g‐C3N4, leading to a micro‐mesoporous substrate.
Raisins in a Hydrogen Pie: Ultrastable Cesium and Rubidium Polyhydrides
Authors: Zhou Di , Semenok Dmitrii , Galasso Michele , Alabarse Frederico Gil , Sannikov Denis , Troyan Ivan A. , Nakamoto Yuki , Shimizu Katsuya , Oganov Artem R.
Published: April 2024

A new method for synthesis of metal polyhydrides via high‐pressure thermal decomposition of corresponding amidoboranes in diamond anvil cells is proposed. Within this approach, molecular semiconducting cesium (P4/nmm‐CsH7, P1‐CsH15+x) and rubidium (RbH9‐x) polyhydrides with a very high hydrogen content reaching 93 at.% are synthesized. Preservation of CsH7 at near ambient conditions, confirmed both experimentally and theoretically, represents a significant advance in the stabilization of hydrogen‐rich compounds. In addition, two crystalline modifications of RbH9‐x with pseudohexagonal and pseudotetragonal structures identified by synchrotron X‐ray diffraction, and Raman measurements are synthesized. Both phases are stable at 8–10 GPa. This is an unprecedentedly low stabilization pressure for polyhydrides. These discoveries open up possibilities for modifying existing hydrogen storage materials to increase their efficiency.
Superdense Lithium Deposition via Mixed Ionic/Electronic Conductive Interfaces Implanted In Vivo/Vitro for Stable Lithium Metal Batteries
Authors: Ma Changjing , Jiang Wenlong , Duan Qiange , Ning De , Wang Man , Wang Jun , Chen Bingan , Jiang Haobo , Yang Chunlei , Wu Wei
Published: April 2024

Lithium metal batteries specialize in energy density, while the immoderate dendrite growth and solid electrolyte interphase (SEI) proliferation have been impeding their practical application. The key is the regulation of Li+ diffusion/nucleation behaviors toward a dense deposition. Herein, Li9Al4/Li3N energized mixed ionic/electronic conductive (MIEC) interfaces are pre‐implanted in both the surface and bulk of the lithium metal anode. Such MIEC interfaces are activated from the in situ conversion and nano‐alloying reactions between AlN and metallic Li and are uniformly dispersed via facile mechanical kneading. In vitro, MIEC interfaces participate in the formation of an inorganic‐enriched SEI that balances ionic transport, electron blocking, and mechanical strength to guarantee homogeneous ion fluxes and structural integrity. In vivo, a unique nanorod‐array architecture enables a released internal stress and rapid diffusion kinetics, affording a dense and large granular plating manner. As a result, the symmetric cell delivers a striking cumulative capacity of >120000 mAh cm−2 at 20 mA cm−2@20 mAh cm−2 with a prolonged lifespan of over 6000 h. The improved machinability also enables a scalable fabrication of ultrathin foil to achieve a stable high‐areal‐capacity full cell for 320 cycles with enhanced energy density characteristics both gravimetrically and volumetrically.
Adding mirror clauses within the European Green Deal: Hype or hope?
Authors: Gohin Alexandre , Matthews Alan
Published: April 2024

The proposed reductions in farm input uses foreseen in the European Green Deal may penalize European farm production while increasing environmental leakages to foreign countries where production may expand. These expected impacts have led to calls for a more restrictive trade policy based on mirror clauses. This paper considers as a case study a potential ban on glyphosate in vegetable and fruits production. We develop an original computable general equilibrium model with endogenous adoption of new European production standards by foreign producers on currently latent markets. We find in our case study that adding mirror clauses to the Green Deal marginally improves European farm income and the global environmental footprint of food. We find that foreign producers as a whole can gain from these clauses and not lose as in a standard analysis. European households support these clauses by paying higher food bills while consuming vegetables and fruits produced without glyphosate.
Integration effects of soil amendments and cover crops on dryland no‐till corn
Authors: Adeli A. , Brooks J. P. , Miles D. M. , Hu J. , Huang Y. , Bheemanahalli R. , Jenkins J. N.
Published: April 2024

A field study was carried out at the Mississippi Agricultural and Forestry Experiment Station near Pontotoc to evaluate the synergistic impacts of broiler litter (BL) and inorganic fertilizer nitrogen (N) with flue gas desulfurization (FGD) gypsum and lignite in the presence of winter cover crops (WCCs) on dryland no‐till corn (Zea mays L.) in Falkner silt loam soil. The experimental design was a split‐plot randomized complete block design with three replications. The main plots were WCC and winter fallow (WF), and the subplots were fertilization treatments. Fertilization treatments included BL, inorganic fertilizer N, FGD gypsum and lignite with BL, FGD gypsum and lignite with inorganic fertilizer N, and an unfertilized control. BL, FGD gypsum, and lignite were applied at the rates of 13.4, 3.4, and 3.4 Mg ha−1, respectively. Inorganic fertilizer N was applied to corn at 168 kg N ha−1. BL increased soil carbon (C), soil infiltration, and resulted in higher corn grain yield compared to both inorganic fertilizer N and unfertilized control in 2020 and 2022. Averaged across fertilization treatments, WCC improved soil moisture, soil C, and soil infiltration by 16%, 19%, and 25% at the 0‐ to 15‐cm depth, respectively, and increased corn grain yield by 25% as compared to WF in 2022. Cover crops boosted corn grain yield during drier years. The combination of FGD gypsum and lignite with BL increased corn grain yield by 15% in 2020 and 13% in 2022 compared to BL alone. This approach can be considered to promote the sustainability of agroecosystems.
Ionic liquid for simultaneous desulfurization and dehydration of flue gas: Data‐driven thermodynamics and mechanisms
Authors: Zhao Fei , Liu Qinghua , Song Minghao , Kang Hongwei , Liu Shuqing , Cheng Yongqiang , Lei Zhigang
Published: April 2024

A process of simultaneous desulfurization and dehydration of flue gas with ionic liquid was explored. The selection of ionic liquid was completed based on COSMO‐SAC model. Random forest (RF) and one‐dimensional convolutional neural network were trained for the prediction of CO2 and SO2 solubility. A feature selection method is designed to remove verbose descriptors. The feature importance was analyzed by SHAP analysis. Quantum chemistry calculation and molecular dynamics (MD) simulation were used to investigate the type and position of intermolecular forces. The results show that the R2 coefficients of the two prediction models for CO2 and SO2 test sets reach 0.981 and 0.983. [EMIM][SCN] was selected as the optimal solvent, and the interaction with SO2 is mainly electrostatic and orbital interaction, while the interaction with H2O is strong hydrogen bond.
Direct biosynthesis of massive intracellular CdSe QDS across entire S. oneidensisMR‐1 for photosynthesis of hydrogen
Authors: Yi Xiaofeng , Liu Shurui , Li Yixin , Luo Qingliu , Li Qingbiao , Xia Dong , Wang Yuanpeng
Published: April 2024

Intracellular biosynthesis of massive quantum dots inside bacteria remains a grand challenge, with such a technology unsatisfactory due to the high toxicity of metal ions to the cell and the ultralow yield of quantum dots. Herein, a gshA‐overexpressed Shewanella oneidensis MR‐1 strain was constructed with the ability to effectively detoxify SeO32− species, rendering the formation of substantial CdSe quantum dots across the entire cell entity. As such, the photoexcited electrons generated from the entire bacterium entity led to promoted electron mobilization efficiency and photoelectron‐involved cellular energy metabolism, along with the direct contact between quantum dots and hydrogenase to significantly reduce electron transfer resistance. Consequently, the constructed system disclosed distinctive performance for artificial H2 photosynthesis, with an appreciable H2 production rate of 32.4 μM⋅h−1. This work opens up new avenues for the direct biosynthesis of intracellular quantum dots across the entire microbes.
Trabecular bone variation in the gorilla calcaneus
Authors: Harper Christine M. , Patel Biren A.
Published: April 2024

Objectives

Calcaneal external shape differs among nonhuman primates relative to locomotion. Such relationships between whole‐bone calcaneal trabecular structure and locomotion, however, have yet to be studied. Here we analyze calcaneal trabecular architecture in Gorilla gorilla gorilla, Gorilla beringei beringei, and G. b. graueri to investigate general trends and fine‐grained differences among gorilla taxa relative to locomotion.

Materials and methods

Calcanei were micro‐CT scanned. A three‐dimensional geometric morphometric sliding semilandmark analysis was carried out and the final landmark configurations used to position 156 volumes of interest. Trabecular thickness (Tb.Th), trabecular spacing (Tb.Sp), and bone volume fraction (BV/TV) were calculated using the BoneJ plugin for ImageJ and MATLAB. Non‐parametric MANOVAs were run to test for significant differences among taxa in parameter raw values and z‐scores. Parameter distributions were visualized using color maps and summarized using principal components analysis.

Results

There are no significant differences in raw BV/TV or Tb.Th among gorillas, however G. b. beringei significantly differs in z‐scores for both parameters (p = <0.0271). All three taxa exhibit relatively lower BV/TV and Tb.Th in the posterior half of the calcaneus. This gradation is exacerbated in G. b. beringei. G. b. graueri significantly differs from other taxa in Tb.Sp z‐scores (p < 0.001) indicating a different spacing distribution.

Discussion

Relatively higher Tb.Th and BV/TV in the anterior calcaneus among gorillas likely reflects higher forces associated with body mass (transmitted through the subtalar joint) relative to forces transferred through the posterior calcaneus. The different Tb.Sp pattern in G. b. graueri may reflect proposed differences in foot positioning during locomotion.
White matter hyperintensities and the surrounding normal appearing white matter are associated with water channel disruption in the oldest old
Authors: Silbert Lisa C. , Roese Natalie E. , Krajbich Victoria , Hurworth Justin , Lahna David , Schwartz Daniel L. , Dodge Hiroko H. , Woltjer Randall L.
Published: April 2024

INTRODUCTION

Age‐related magnetic resonance imaging (MRI) T2 white matter hyperintensities (WMHs) are common and associated with neurological decline. We investigated the histopathological underpinnings of MRI WMH and surrounding normal appearing white matter (NAWM), with a focus on astroglial phenotypes.

METHODS

Brain samples from 51 oldest old Oregon Alzheimer's Disease Research Center participants who came to autopsy underwent post mortem (PM) 7 tesla MRI with targeted histopathological sampling of WMHs and NAWM. Stained slides were digitized and quantified. Mixed‐effects models determined differences in molecular characteristics between WMHs and the NAWM and across NAWM.

RESULTS

PM MRI‐targeted WMHs are characterized by demyelination, microglial activation, and prominent astrocytic alterations, including disrupted aquaporin (AQP) expression. Similar changes occur within the surrounding NAWM in a pattern of decreasing severity with increased distance from WMHs.

DISCUSSION

Decreased AQP expression within WMH and proximal NAWM suggest an overwhelmed system wherein water homeostasis is no longer maintained, contributing to WM damage in older individuals.

Highlights

Post mortem magnetic resonance imaging (MRI) was used to characterize the pathology of white matter hyperintensities (WMHs) and surrounding normal appearing white matter (NAWM).

Stained immunohistochemical (IHC) slides from targeted WMH and NAWM samples were digitized and quantified.

WMHs and NAWM were associated with inflammation, demyelination, and gliosis.

WMHs and NAWM astrocytic changes included decreased AQP1 and AQP4 expression.

Abnormal NAWM pathology diminished in severity with increasing distance from WMH.
Optomechanical Coupling Optimization in Engineered Nanocavities
Authors: Edelstein S. , Gomis‐Bresco J. , Arregui G. , Koval P. , Lanzillotti‐Kimura N. D. , Torrent D. , Sotomayor‐Torres C. M. , García P. D.
Published: April 2024

In optomechanics, the interaction between light and matter is enhanced by engineering cavities where the electromagnetic field and the mechanical displacement are confined simultaneously within the same volume. This leads to a wide range of interesting phenomena, such as optomechanically induced transparency and the cooling of macroscopic objects to their lowest possible motion state. In this manuscript, the focus is on designed optomechanical cavities exploiting heterostructures in air‐slot photonic‐crystal waveguides, incorporating different hole shapes and dimensions to engineer and control their optomechanical properties. The aim is to maximize the optical quality factor of the optical cavity, while ensuring optical mode volumes below the diffraction limit. These optimized optical modes interact with in‐plane motional degrees of freedom of the structures achieving high optomechanical coupling rates, thus opening up the possibility of mechanical amplification, nonlinear dynamics and chaos through the optomechanical back‐action.
Perfluorooxosulfate Salts as SOF4‐Gas‐Free Precursors to Multidimensional SuFEx Electrophiles
Authors: Zogu Armir , Ullah Karim , Spanopoulos Stefanos , Ismalaj Ermal , De Borggraeve Wim M. , Demaerel Joachim
Published: April 2024

Sulfur(VI) Fluoride Exchange (SuFEx) chemistry stands as a well‐established method for swiftly constructing complex molecules in a modular fashion. An especially promising segment of this toolbox is reserved for multidimensional SuFEx hubs: three or more substituents pluggable into a singular SVI centre to make ‘beyond‐linear’ clicked constructions. Sulfurimidoyl difluorides (RNSOF2) stand out as the prime example of this, however their preparation from the scarcely available thionyl tetrafluoride (SOF4) limits this chemistry to only a few laboratories with access to this gas. In this work, we identify silver pentafluorooxosulfate (AgOSF5) as a viable SuFEx hub with reactivity equal to SOF4. The AgF2‐mediated oxidation of SOCl2 gives rise to the hexacoordinate AgOSF5 adduct, which in contact with primary amines produces the sulfurimidoyl fluorides in high yields. In addition, we have found this workflow to be fully extendable to the trifluoromethyl homologue, AgOSF4CF3, and we propose the use of AgOSF4X salts as a general route to azasulfur SuFEx electrophiles from commercial starting materials.
SilE−R und SilE−S – DABB‐Proteine mit der Fähigkeit zur enantiospezifischen Hydrolyse von Organosilylethern
Authors: Pick Lisa M. , Oehme Viviane , Hartmann Julia , Wenzlaff Jessica , Tang Qingyun , Grogan Gideon , Ansorge‐Schumacher Marion B.
Published: April 2024

Silylether spielen in der synthetisch‐organischen Chemie als Schutzgruppen eine wichtige Rolle. Einen Schlüsselfaktor für ihre Verwendung bildet die selektive Spaltung. Erstmals stellen wir hier zwei Enzyme – SilE−R und SilE−S – vor, die in der Lage sind, Silylether zu hydrolysieren. Sie gehören zur Familie der Stress‐Response‐A/B‐Barrel‐Domäne‐beinhaltenden Proteine (DABB) und spalten die Si−O‐Bindung mit entgegengesetzter Enantiopräferenz. Akzeptiert werden Silylether mit aromatischen, cyclischen oder aliphatischen Alkoholanteilen und, je nach Alkohol, Silylfunktionen bis hin zu TBDMS. Aus der Röntgenkristallstruktur von SilE−R, die mit einer Auflösung von 1,98 Å bestimmt wurde, und Mutationsstudien konnte ein aktives Zentrum mit zwei Histidinresten, H8 und H79, abgeleitet werden. Die Reste scheinen synergistisch als Nukleophil und Brønsted‐Base zu wirken, wie es in bekannten Mechanismen der enzymatischen Hydrolyse bisher nicht beschrieben wurde. Die natürliche Funktion von SilE−R und SilE−S ist noch unbekannt, für synthetische Anwendungen ist aber großes Potenzial dieser „Silyletherasen“ zu erwarten.
Organo‐Photocatalytic Anti‐Markovnikov Hydroamidation of Alkenes with Sulfonyl Azides: A Combined Experimental and Computational Study
Authors: Fu Rui , Xu Mengyu , Wang Yujing , Wu Xinxin , Bao Xiaoguang
Published: April 2024

The construction of C(sp3)−N bonds via direct N‐centered radical addition with olefins under benign conditions is a desirable but challenging strategy. Herein, we describe an organo‐photocatalytic approach to achieve anti‐Markovnikov alkene hydroamidation with sulfonyl azides in a highly efficient manner under transition‐metal‐free and mild conditions. A broad range of substrates, including both activated and unactivated alkenes, are suitable for this protocol, providing a convenient and practical method to construct sulfonylamide derivatives. A synergistic experimental and computational mechanistic study suggests that the additive, Hantzsch ester (HE), might undergo a triplet‐triplet energy transfer manner to achieve photosensitization by the organo‐photocatalyst under visible light irradiation. Next, the resulted triplet excited state 3HE* could lead to a homolytic cleavage of C4−H bond, which triggers a straightforward H‐atom transfer (HAT) style in converting sulfonyl azide to the corresponding key amidyl radical. Subsequently, the addition of the amidyl radical to alkene followed by HAT from p‐toluenethiol could proceed to afford the desired anti‐Markovnikov hydroamidation product. It is worth noting that mechanistic pathway bifurcation could be possible for this reaction. A feasible radical chain propagation mechanistic pathway is also proposed to rationalize the high efficiency of this reaction.
A Zeolitic Octahedral Metal Oxide with Ultrahigh Porosity for High‐temperature and High‐humidity Alkyne/Alkene Separation
Authors: Ma Baokai , Hu Panpan , Zou Liangcheng , Zhu Qianqian , Zhang Lifeng , Ishikawa Satoshi , Ueda Wataru , Li Yanshuo , Zhang Zhenxin
Published: April 2024

Zeolitic octahedral metal oxide is a newly synthesized all‐inorganic zeolitic material and has been used for adsorption, separation, and catalysis. Herein, a new zeolitic octahedral metal oxide was synthesized and characterized. The porous framework was established through the assembly of [P2Mo13O50] clusters with PO4 linkers. Guest molecules occupied the framework, which could be removed through heat treatment, thereby opening the micropores. The pore characteristics were controlled by the cations within the micropore, enabling the adjustment of the interactions with alkynes and alkenes. This resulted in good separation performance of ethylene/acetylene and propylene/propyne even under high temperature and humidity conditions. The high stability of the material enabled the efficient recovery and reuse without discernible loss in the separation performance. Due to the relatively weak interaction between the adsorbed alkyne and the framework, the adsorbent facilitated the recovery of a highly pure alkyne. This feature enhances the practical applicability of the material in various industrial processes.
SilE‐R and SilE‐S—DABB Proteins Catalysing Enantiospecific Hydrolysis of Organosilyl Ethers
Authors: Pick Lisa M. , Oehme Viviane , Hartmann Julia , Wenzlaff Jessica , Tang Qingyun , Grogan Gideon , Ansorge‐Schumacher Marion B.
Published: April 2024

Silyl ethers fulfil a fundamental role in synthetic organic chemistry as protecting groups and their selective cleavage is an important factor in their application. We present here for the first time two enzymes, SilE−R and SilE−S, which are able to hydrolyse silyl ethers. They belong to the stress‐response dimeric A/B barrel domain (DABB) family and are able to cleave the Si−O bond with opposite enantiopreference. Silyl ethers containing aromatic, cyclic or aliphatic alcohols and, depending on the alcohol moiety, silyl functions as large as TBDMS are accepted. The X‐ray crystal structure of SilE−R, determined to a resolution of 1.98 Å, in combination with mutational studies, revealed an active site featuring two histidine residues, H8 and H79, which likely act synergistically as nucleophile and Brønsted base in the hydrolytic mechanism, which has not previously been described for enzymes. Although the natural function of SilE−R and SilE−S is unknown, we propose that these ‘silyl etherases’ may have significant potential for synthetic applications.
Binuclear copper complex as a new dual‐use catalyst for cycloaddition and coupling reactions: Synthesis, characterization, and application
Authors: Amini Mojtaba , Sheykhi Ayda , Khandar Ali Akbar , Janczak Jan
Published: April 2024

A binuclear copper (II) complex [Cu2(dien)2(ox)(ClO4)] (dien = diethylenetriamine and ox = oxalate) was readily synthesized and obtained in the perchlorate salt form. The structure of the compound has been determined using X‐ray crystallography, UV–Vis spectroscopy, and infrared techniques. This new catalyst has effectively facilitated the production of 1,2,3‐triazole derivatives by “Click reaction” in an aqueous environment and propargylamine derivatives by “A3‐coupling reaction” under solvent‐free conditions, resulting in yields ranging from good to excellent. Additionally, subsequent investigations have revealed that this catalytic system can be recovered and reused for up to five cycles in both cycloaddition and coupling reactions.
Preparation and characterization of reprocessable poly(1,2,3‐triazolium)
Authors: Zhang Jun , Lv Shuaikang , Tang Junkun , Liu Zuozhen , Huang Farong
Published: April 2024

Poly(1,2,3‐triazolium) (PTAM) is a dynamic reversible crosslinking polymer based on 1,2,3‐triazolium. Structural rearrangement of PTAM can occur through dynamic exchange reactions of 1,2,3‐triazolium. But there are not any applications derived from the dynamic reversible crosslinking properties of 1,2,3‐triazolium. In the paper, to expand the function and application of PTAM, a reprocessable PTAM resin has been prepared and the reprocess ability is studied in detail. PTAM can achieve complete stress relaxation within 2 min at 160°C through the exchange reaction of dynamically reversible crosslinked 1,2,3‐triazolium. Under the condition of 160°C and 10 MPa pressure, PTAM can achieve mechanical properties recovery after 2 h of reprocessing. The recovery rate of tensile strength can reach 94.2%. After four consecutive cycles reprocessing, the recovery rate of tensile strength is maintained at about 90%. And the thermal stability of PTAM is unchanged. PTAM has a possible application in the recycling of thermoset‐based plastics and composites. The result provides a reference for the functional application and development of dynamic reversible crosslinking polymers.
Whole‐body donation through the lens of Shona culture and Christian religion in Zimbabwe
Authors: Dongo Varaidzo , Chengetanai Samson , Chibhabha Fidelis
Published: April 2024

Voluntary donation is the ethically acceptable method for whole‐body acquisition for anatomy education worldwide. In Africa, educational institutions struggle with this since many people remain unwilling to donate their bodies due to the strong influence of cultural and religious beliefs in decision‐making. As part of wider efforts to improve the ethical sourcing of bodies in Zimbabwean medical schools, which are heavily reliant on unclaimed bodies, this study sought to determine the influences traditional and religious beliefs have on such decisions. We ascertained traditional and religious leaders' knowledge of whole‐body donation, explored cultural and religious views toward death, dying and whole‐body donation as well as their underlying reasons. Semi‐structured interviews were conducted with traditional chiefs and Christian leaders who are considered the custodians of Zimbabwean traditional cultural and Christian values, respectively. Thematic analysis of traditional chiefs' interviews revealed that none of the chiefs had accurate knowledge regarding whole‐body donation or the processes involved. Due to set traditional practices around death, most traditional chiefs viewed the practice as foreign with possible negative repercussions to the dissectors. Most of the Christian leaders had knowledge of whole‐body donation. Their views were split between support for whole‐body donation and regard as a religious and cultural misfit. Overall, both traditional chiefs and Christian leaders understood the importance of whole‐body donation and requested further societal sensitization and education if the practice is to become socially acceptable.
Modelling on a Biomimetic [Cu−O−Cu]2+–mediated Methane–to–Methanol Conversion Unveils the Site for Methane Activation
Authors: Arora Sumangla , Gupta Puneet
Published: April 2024

The Cu−O−Cu core exhibits methane‐to‐methanol conversion, mirroring the reactivity of the copper–containing enzyme pMMO. Herein, we computationally examined the reactivity of a biomimetic Cu−O−Cu core towards methane–to–methanol conversion. The oxygen atom of the Cu−O−Cu core abstracts hydrogen present in the C−H bond of methane. The spin density at the bridging oxygen helps to abstract hydrogen from the C−H bond. We modulated the spin density of the bridging oxygen by substituting only a single copper atom of the Cu−O−Cu core by metals (M) such as Fe, Co, and Ag. These substitutions result in bimetallic [Cu−O−M]2+ models. We observed that the energy barriers for the C−H activation step and the subsequent rebound step vary with the metal M. [Cu−O−Ag]2+ exhibits the highest reactivity for M2M conversion, while [Cu−O−Fe]2+ displays the lowest reactivity. To understand the different reactivity of these models towards M2M conversion, we employed distortion‐interaction analysis, orbital analysis, spin density analysis, and quantum theory of atoms in molecules analysis. Orbital analysis reveals that all four adducts follow a hydrogen atom transfer mechanism for C−H activation. Further, spin density analysis reveals that a higher spin density on the bridging oxygen leads to a lower C−H activation barrier.
Current treatment and novel insights regarding ROS1‐targeted therapy in malignant tumors
Authors: Li Shizhe , Zhang He , Chen Ting , Zhang Xiaowen , Shang Guanning
Published: April 2024

Background

The proto‐oncogene ROS1 encodes an intrinsic type I membrane protein of the tyrosine kinase/insulin receptor family. ROS1 facilitates the progression of various malignancies via self‐mutations or rearrangements. Studies on ROS1‐directed tyrosine kinase inhibitors have been conducted, and some have been approved by the FDA for clinical use. However, the adverse effects and mechanisms of resistance associated with ROS1 inhibitors remain unknown. In addition, next‐generation ROS1 inhibitors, which have the advantage of treating central nervous system metastases and alleviating endogenous drug resistance, are still in the clinical trial stage.

Method

In this study, we searched relevant articles reporting the mechanism and clinical application of ROS1 in recent years; systematically reviewed the biological mechanisms, diagnostic methods, and research progress on ROS1 inhibitors; and provided perspectives for the future of ROS1‐targeted therapy.

Results

ROS1 is most expressed in malignant tumours. Only a few ROS1 kinase inhibitors are currently approved for use in NSCLC, the efficacy of other TKIs for NSCLC and other malignancies has not been ascertained. There is no effective standard treatment for adverse events or resistance to ROS1‐targeted therapy. Next‐generation TKIs appear capable of overcoming resistance and delaying central nervous system metastasis, but with a greater incidence of adverse effects.

Conclusions

Further research on next‐generation TKIs regarding the localization of ROS1 and its fusion partners, binding sites for targeted drugs, and coadministration with other drugs is required. The correlation between TKIs and chemotherapy or immunotherapy in clinical practice requires further study.
Bioactives of Melipona rufiventris Propolis: Exploring its Antimicrobial, Anti‐Inflammatory, and Antioxidant Activities
Authors: Santini Amanda Tristão , Pinto Rayra Annara Otacílio , Lazarini Josy Goldoni , de Morais Daniel Vieira , de Piloto Fernandes Anna Maria Alves , Franchin Marcelo , de Carvalho Patrícia Lunardelli Negreiros , Pressete Carolina Girotto , Rosalen Pedro Luiz , de Alencar Severino Matias , de Oliveira Carvalho Patrícia , Ionta Marisa , Ikegaki Masaharu
Published: April 2024

This study explores the potential of propolis, a resinous substance produced by bees, from Melipona rufiventris species. With its composition encompassing resin, wax, pollen, and soil, propolis holds historical significance in traditional medicine within tropical regions. This research is driven by the scarcity of information surrounding M. rufiventris propolis, prompting an investigation into its chemical constituents, in vivo toxicity, and antimicrobial, antioxidant, and anti‐inflammatory properties. This exploration could potentially uncover novel applications for this natural product, bolstering both meliponiculture practices and the preservation of native bee populations. The propolis was sampled in Cabo Verde‐MG and underwent ethanolic extraction to yield an extract (EEP) for analysis. Chemical assessments (Folin‐Ciocalteau, and UHPLC‐HRMS) revealed the presence of polyphenols, including flavonoids. The EEP demonstrated higher antimicrobial activity against Gram‐positive bacteria and exhibited efficacy against multiresistant strains isolated from complex wounds. Synergistic interactions with commercial antibiotics were also observed. Furthermore, anti‐inflammatory evaluations showcased the EEP′s potential in reducing NF‐kB activation and TNF‐α release at non‐toxic concentrations. Despite these promising biological activities, the EEP exhibited no antiproliferative effects and demonstrated safety in both the MTS assay and the G. mellonella model. Collectively, these findings highlight the M. rufiventris propolis extract as a valuable reservoir of bioactive compounds with multifaceted potential.
Co‐Immobilization of ADH and GDH on Metal–Organic‐Framework: An Effective Biocatalyst for Asymmetric Reduction of Ketones
Authors: Ran Lu , Lin Yu , Su Guorong , Yang Zhenyan , Teng Huailong
Published: April 2024

Chiral alcohols are not only important building blocks of various bioactive natural compounds and pharmaceuticals, but can serve as synthetic precursors for other valuable organic chemicals, thus the synthesis of these products is of great importance. Bio‐catalysis represents one effective way to obtain these molecules, however, the weak stability and high cost of enzymes often hinder its broad application. In this work, we designed a biological nanoreactor by embedding alcohol dehydrogenase (ADH) and glucose dehydrogenase (GDH) in metal‐organic‐framework ZIF‐8. The biocatalyst ADH&GDH@ZIF‐8 could be applied to the asymmetric reduction of a series of ketones to give chiral alcohols in high yields (up to 99 %) and with excellent enantioselectivities (>99 %). In addition, the heterogeneous biocatalyst could be recycled and reused at least four times with slight activity decline. Moreover, E. coli containing ADH and GDH was immobilized by ZIF‐8 to form biocatalyst E. coli@ZIF‐8, which also exhibits good catalytic behaviours. Finally, the chiral alcohols are further converted to marketed drugs (R)‐Fendiline, (S)‐Rivastigmine and NPS R‐568 respectively.
Tuning the Microenvironment of Co−N4 Ensemble for Co Single‐Atom Catalysts for Electrocatalytic CO2 Reduction
Authors: Zeng Zizhen , Xu Junli , Zhao Yiran , Li Jiwei , Du Congcong , Sun Yifei , Xiong Haifeng
Published: April 2024

Single‐atom catalysts (SACs), with their well‐defined structure, serve as an efficient catalyst model for studying the structure‐performance relation in the electrocatalytic CO2 reduction reaction (CO2RR). Current CO2RR research primarily focus on the coordination interactions between metal single atoms and coordinated ligands, while the impact of the metal SAC′s microenvironment remains largely unexplored. Herein, we generate three microenvironments for a CoN4 ensemble by using different nitrogen sources to prepare Co SACs, i. e. pyridine‐type Co−N4 (Co−N4 SACPhen), the pyrrole‐type Co−N4 (Co−N4 SACDp) and the mixed‐type Co−N4(Co−N4 SACMm). It reveals that the Co−N4 SACPhen contributes to CO generation with 99.5 % selectivity at −0.76 vs RHE, whereas the Co−N4 SACDp accelerates a severe hydrogen evolution reaction. Experimental studies confirmed that the Co−N4 SACPhen possesses distinctive electrochemical properties and electronic structure, with the pyridine‐N being more conducive to electron accumulation and exhibited a higher electron delocalization, thereby promoting the generation of CO. This study deepens our understanding of the cobalt SAC′s microenvironment‘s influence on CO2RR.
Artificial Metalloenzyme‐Catalyzed Enantioselective Carboamination of Alkenes
Authors: Yu Kun , Tachibana Ryo , Rumo Corentin , Igareta Nico V. , Zhang Kailin , Ward Thomas R.
Published: April 2024

Relying on ubiquitous alkenes, carboamination reactions enable the difunctionalization of the double bond by the concurrent formation of a C−N and a C−C single bond. In the past years, several groups have reported on elegant strategies for the carboamination of alkenes relying on homogeneous catalysts or enzymes. Herein, we report on an artificial metalloenzyme for the enantioselective carboamination of dihydrofuran. Genetic optimization, combined with a Bayesian optimization of catalytic performance, afforded the disubstituted tetrahydrofuran product in up to 22 TON and 85 % ee. X‐ray analysis of the evolved artificial carboaminase shed light on critical amino acid residues that affect catalytic performance.
Confined cobalt single‐atom catalysts with strong electronic metal‐support interactions based on a biomimetic self‐assembly strategy
Authors: Guo Bowen , Wang Zekun , Zheng Lei , Mo Guang , Zhou Hongjun , Luo Dan
Published: April 2024

Designing high‐performance and low‐cost electrocatalysts for oxygen evolution reaction (OER) is critical for the conversion and storage of sustainable energy technologies. Inspired by the biomineralization process, we utilized the phosphorylation sites of collagen molecules to combine with cobalt‐based mononuclear precursors at the molecular level and built a three‐dimensional (3D) porous hierarchical material through a bottom‐up biomimetic self‐assembly strategy to obtain single‐atom catalysts confined on carbonized biomimetic self‐assembled carriers (Co SACs/cBSC) after subsequent high‐temperature annealing. In this strategy, the biomolecule improved the anchoring efficiency of the metal precursor through precise functional groups; meanwhile, the binding‐then‐assembling strategy also effectively suppressed the nonspecific adsorption of metal ions, ultimately preventing atomic agglomeration and achieving strong electronic metal‐support interactions (EMSIs). Experimental characterizations confirm that binding forms between cobalt metal and carbonized self‐assembled substrate (Co–O4–P). Theoretical calculations disclose that the local environment changes significantly tailored the Co d‐band center, and optimized the binding energy of oxygenated intermediates and the energy barrier of oxygen release. As a result, the obtained Co SACs/cBSC catalyst can achieve remarkable OER activity and 24 h durability in 1 M KOH (η10 at 288 mV; Tafel slope of 44 mV dec−1), better than other transition metal‐based catalysts and commercial IrO2. Overall, we presented a self‐assembly strategy to prepare transition metal SACs with strong EMSIs, providing a new avenue for the preparation of efficient catalysts with fine atomic structures.
Biphase‐to‐monophase structure evolution of Na0.766+xLixNi0.33−xMn0.5Fe0.1Ti0.07O2 toward ultradurable Na‐ion batteries
Authors: Liu Mengting , Cheng Zhiwei , Zhu Xu , Dong Haojie , Yan Tianran , Zhang Liang , Zheng Lu , Yao Hu‐Rong , Wang Xian‐Zuo , Yu Lianzheng , Xiao Bing , Xiao Yao , Wang Peng‐Fei
Published: April 2024

Layered composite oxide materials with O3/P2 biphasic crystallographic structure typically demonstrate a combination of high capacities of the O3 phase and high operation voltages of the P2 phase. However, their practical applications are seriously obstructed by difficulties in thermodynamic phase regulation, complicated electrochemical phase transition, and unsatisfactory cycling life. Herein, we propose an efficient structural evolution strategy from biphase to monophase of Na0.766+xLixNi0.33−xMn0.5Fe0.1Ti0.07O2 through Li+ substitution. The role of Li+ substitution not only simplifies the unfavorable phase transition by altering the local coordination of transition metal (TM) cations but also stabilizes the cathode–electrolyte interphase to prevent the degradation of TM cations during battery cycling. As a result, the thermodynamically robust O3‐Na0.826Li0.06Ni0.27Mn0.5Fe0.1Ti0.07O2 cathode delivers a high capacity of 139.4 mAh g−1 at 0.1 C and shows prolonged cycling life at high rates, with capacity retention of 81.6% at 5 C over 500 cycles. This work establishes a solid relationship between the thermodynamic structure evolution and electrochemistry of layered cathode materials, contributing to the development of long‐life sodium‐ion batteries.