bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polyoxometalate‐Based Metal–Organic Framework as Molecular Sieve for Highly Selective Semi‐Hydrogenation of Acetylene on Isolated Single Pd Atom Sites
Authors: Liu Yiwei , Wang Bingxue , Fu Qiang , Liu Wei , Wang Yu , Gu Lin , Wang Dingsheng , Li Yadong 
Published: August 2021

AbstractAchieving highly selective acetylene semi‐hydrogenation in an ethylene‐rich gas stream is of great industrial importance. Herein, we construct isolated single Pd atom in a polyoxometalate‐based metal‐organic framework (POMOF). The unique internal environment allows this POMOF to separate acetylene from acetylene/ethylene gas mixtures and confine it close to the single Pd atom. After semi‐hydrogenation, the resulting ethylene is preferentially discharged from the pores, achieving a selectivity of 92.6 %. First‐principles simulations reveal that the adsorbed acetylene/ethylene molecules form hydrogen bond networks with oxygen atoms of SiW12O404− and create dynamic confinement regions, which preferentially release the produced ethylene. Besides, at the Pd site, the over‐hydrogenation of ethylene exhibits a higher reaction energy barrier than the semi‐hydrogenation of acetylene. The combined advantages of POMOF and single Pd atom provides an effective approach for the regulation of semi‐hydrogenation selectivity.
A Heteromeric Carboxylic Acid Based Single‐Crystalline Crosslinked Organic Framework
Authors: Liang Rongran , Samanta Jayanta , Shao Baihao , Zhang Mingshi , Staples Richard J. , Chen Albert D. , Tang Miao , Wu Yuyang , Aprahamian Ivan , Ke Chenfeng 
Published: August 2021

AbstractThe development of large pore single‐crystalline covalently linked organic frameworks is critical in revealing the detailed structure‐property relationship with substrates. One emergent approach is to photo‐crosslink hydrogen‐bonded molecular crystals. Introducing complementary hydrogen‐bonded carboxylic acid building blocks is promising to construct large pore networks, but these molecules often form interpenetrated networks or non‐porous solids. Herein, we introduced heteromeric carboxylic acid dimers to construct a non‐interpenetrated molecular crystal. Crosslinking this crystal precursor with dithiols afforded a large pore single‐crystalline hydrogen‐bonded crosslinked organic framework HCOF‐101. X‐ray diffraction analysis revealed HCOF‐101 as an interlayer connected hexagonal network, which possesses flexible linkages and large porous channels to host a hydrazone photoswitch. Multicycle Z/E‐isomerization of the hydrazone took place reversibly within HCOF‐101, showcasing the potential use of HCOF‐101 for optical information storage.
Chalcogenides by Reduction of their Dioxides in Ultra‐Alkaline Media
Authors: Albrecht Ralf , Ruck Michael 
Published: August 2021

AbstractThe reaction of chalcogen dioxides ChO2 (Ch=Se, Te) with As2O3 in a 30 molar KOH hydroflux at about 200 °C yielded crystals of potassium trichalcogenides K2Ch3 with dimensions up to 2 cm. Arsenic trioxide acts as electron donor and is oxidized to arsenate(V). The new heterochalcogenide anion (TeSe2)2− formed when starting from SeO2 and TeO2 simultaneously. The compound K2TeSe2 crystallizes isostructural to K2S3 and K2Se3. The unexpected redox reaction as well as the precipitation of hygroscopic compounds from an aqueous solution are attributed to a strongly reduced activity of water. The reactions were studied by Raman and UV/Vis spectroscopy. Depending on the concentration of As2O3, colorless monochalcogenide Ch2− or orange Se22− and purple Te22− anions are dominating the solutions.
Various Stacking Patterns of Two‐Dimensional Molecular Assemblies in Hydrogen‐Bonded Cocrystals: Insight into Competitive Intermolecular Interactions and Control of Stacking Patterns
Authors: Donoshita Masaki , Yoshida Yukihiro , Hayashi Mikihiro , Ikeda Ryuichi , Tanaka Susumu , Yamamura Yasuhisa , Saito Kazuya , Kawaguchi Shogo , Sugimoto Kunihisa , Kitagawa Hiroshi 
Published: August 2021

AbstractControl over the stacking patterns in 2D molecular assemblies is demonstrated using chemical modification. A target system is a hydrogen‐bonded cocrystal (2:1) composed of 2‐pyrrolidone (Py) and chloranilic acid (CA) (PyCA). X‐ray crystallography showed that weak intersheet interactions give rise to a variety of metastable overlapping patterns comprised of the 2D assemblies mainly formed via hydrogen bonds, affording reversible and irreversible structural phase transitions. We prepared cocrystals of Py and anilic acids bearing different halogens, in which 2D assemblies isostructural with those observed in PyCA exhibit various overlapping patterns. The order of stability for each overlapping pattern estimated using calculations of the intermolecular interactions did not completely coincide with those indicated by our experimental results, which can be explained by considering the entropic effect: the molecular motion of Py as detected using nuclear quadrupole resonance spectroscopy.
Bending for Better: Flexible Organic Single Crystals with Controllable Curvature and Curvature‐Related Conductivity for Customized Electronic Devices
Authors: Chen Yifu , Chang Zewei , Zhang Jiaxing , Gong Junbo 
Published: August 2021

AbstractElectronic microdevices of self‐bending coronene crystals are developed to reveal an unexplored link between mechanical deformation and crystal function. First, a facile approach towards length/width/curvature‐controllable micro‐crystals through bottom‐up solution crystallization was proposed for high processability and stability. The bending crystal devices show a significant increase beyond seven orders of magnitude in conductivity than the straight ones, providing the first example of deformation‐induced function enhancement in crystal materials. Besides, double effects caused by bending, including the change of π electron level as well as the enhancement of carrier mobility, were determined, respectively by the X‐ray photoelectric spectroscopy and X‐ray crystallography to coexist, contributing to the conductivity improvement. Our findings will promote future creation of flexible organic crystal systems with deformation‐enhanced functional features towards customized smart devices.
Crystal Structure Classification of Copper‐Based Sulfides as a Tool for the Design of Inorganic Functional Materials
Authors: Lemoine Pierric , Guélou Gabin , Raveau Bernard , Guilmeau Emmanuel 
Published: August 2021

AbstractResearch focusing on the interplay between structural features and transport properties of inorganic materials is of paramount importance for the identification, comprehension, and optimisation of functional materials. In this respect, Earth‐abundant copper sulfides have been receiving considerable attention from scientists as the urgency remains to discover and improve the efficiency of sustainable materials for energy applications. This proposed classification of copper sulfides, associated with p‐ and/or d‐block elements, is based on their crystallographic features and an analysis of their transport properties. It provides guidelines to help estimate some properties of new materials (type of main charge carriers, thermal conductivity, transport mechanisms, etc.) from consideration of only their chemical composition and crystal structure. The classification relies primarily on recent studies in the fields of thermoelectricity and photovoltaics as well as on crystal‐structure investigations.
Epitaxially Grown Heterostructured SrMn3O6−x‐SrMnO3 with High‐Valence Mn3+/4+ for Improved Oxygen Reduction Catalysis
Authors: Chen Cheng , Wang Xiao‐Tong , Zhong Jia‐Huan , Liu Jinlong , Waterhouse Geoffrey I. N. , Liu Zhao‐Qing 
Published: August 2021

AbstractHeterostructured catalysts show outstanding performance in electrochemical reactions owing to their beneficial interfacial properties. However, the rational design of heterostructured catalysts with the desired interfacial properties and charge‐transfer characteristics is challenging. Herein, we developed a SrMn3O6−x‐SrMnO3 (SMOx‐SMO) heterostructure through epitaxial growth, which demonstrated excellent electrocatalyst performance for the oxygen reduction reaction (ORR). The formation of high‐valence Mn3+/4+ is beneficial for promoting a positive shift in the position of the d‐band center, thereby optimizing the adsorption and desorption of ORR intermediates on the heterojunction surface and resulting in improved catalytic activity. When SMOx‐SMO was applied as an air‐electrode catalyst in a rechargeable zinc‐air battery, a high output voltage and power density was achieved, with performance comparable to a battery prepared with Pt/C‐IrO2 air‐electrode catalysts, albeit with much better cycling stability.
Photothermal‐Assisted Triphase Photocatalysis Over a Multifunctional Bilayer Paper
Authors: Huang Huining , Shi Run , Zhang Xuerui , Zhao Jiaqing , Su Chenliang , Zhang Tierui 
Published: August 2021

AbstractPhotocatalysis as one of the future environment technologies has been investigated for decades. Despite great efforts in catalyst engineering, the widely used powder dispersion and photoelectrode systems are still restricted by sluggish interfacial mass transfer and chemical processes. Here we develop a scalable bilayer paper from commercialized TiO2 and carbon nanomaterials, self‐supported at gas‐liquid‐solid interfaces for photothermal‐assisted triphase photocatalysis. The photogeneration of reactive oxygen species can be facilitated through fast oxygen diffusion over triphase interfaces, while the interfacial photothermal effect promotes the following free radical reaction for advanced oxidation of phenol. Under full spectrum irradiation, the triphase system shows 13 times higher reaction rate than diphase controlled system, achieving 88.4 % mineralization of high concentration phenol within 90 min full spectrum irradiation. The bilayer paper also exhibits high stability over 40 times cycling experiments and sunlight driven feasibility, showing potentials for large scale photocatalytic applications by being further integrated into a triphase flow reactor.
Fragment‐type 4‐azolylcoumarin derivatives with anticancer properties
Authors: Simic Milena , Petkovic Milos , Jovanovic Predrag , Jovanovic Milos , Tasic Gordana , Besu Irina , Zizak Zeljko , Aleksic Ivana , Nikodinovic‐Runic Jasmina , Savic Vladimir 
Published: August 2021

AbstractSeveral coumarin derivatives with a directly attached azole substituent at C‐4 were synthesized and biologically studied for their anticancer properties. The cell lines used for this investigation (HeLa, K‐562, MDA‐MB‐53, and MCF‐7) demonstrated different sensitivities. The best response in the MTT (3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2H‐tetrazolium bromide) assay was shown by K‐562 cells, with compounds displaying activity (3c, IC50 3.06 μM; 4a, IC50 5.24 μM; 4c, IC50 4.7 μM) similar to that of cisplatin (IC50 ~6 μM), which was used as the standard. The studied azole‐substituted coumarins demonstrated weaker activity toward other cell lines, except for compound 4c, which was equally potent in the case of MCF‐7 cells. Additional biological evaluations supported interference with the cell cycle as a potential mechanism of action and confirmed the absence of toxicity in zebrafish embryos. On the basis of these initial results, 4‐azole coumarins should be explored further. Although their activity would need additional optimization, the fact that these compounds are fragment‐like structures with MW <300 and clog P <3 offers enough flexibility to fine‐tune their drug‐like properties.
Cu Doping‐Induced Transformation from [Ag62S12(SBut)32]2+ to [Ag62−xCuxS12(SBut)32]4+ Nanocluster
Authors: Zhou Jun , Yang Sha , Tan Yesen , Cheng Huaisheng , Chai Jinsong , Zhu Manzhou 
Published: August 2021

AbstractThe change in the valence state of nanocluster can induce remarkable changes in the properties and structure. However, achieving the valence state changes in nanoclusters is still a challenge. In this work, we use Cu2+ as dopant to “oxidize” [Ag62S12(SBut)32]2+ (4 free electrons) to obtain the new nanocluster: [Ag62−xCuxS12(SBut)32]4+ with 2 free electrons. As revealed by its structure, the [Ag62−xCuxS12(SBut)32]4+ (x=10∼21) has a similar structure to that of [Ag62S12(SBut)32]2+ precursor and all the Cu atoms occupy the surface site of nanocluster. It′s worth noting that with the Cu atoms doping, the [Ag62−xCuxS12(SBut)32]4+ nanocluster is more stable than [Ag62S12(SBut)32]2+ at higher temperature and in electrochemical cycle. This result has laid a foundation for the subsequent application and exploration. Overall, this work reveals crystals structure of a new Ag−Cu nanocluster and offers a new insight into the electron reduction/oxidation of nanocluster.
Refined pancreatobiliary UroVysion criteria and an approach for further optimization
Authors: Mettman Daniel , Saeed Azhar , Shold Janna , Laury Raquele , Ly Andrew , Khan Irfan , Golem Shivani , Olyaee Mojtaba , O'Neil Maura 
Published: August 2021

AbstractPancreatobiliary strictures are a common source of false negatives for malignancy detection. UroVysion is more sensitive than any other method but remains underutilized because of conflicting sensitivities and specificities due to a lack of standardized cutoff criteria and confusion in interpreting results in the context of primary sclerosing cholangitis. We set out to determine the sensitivities and specificities of UroVysion, brushing cytology, forceps biopsies, and fine needle aspiration (FNAs) for pancreatobiliary stricture malignancy detection. A retrospective review was performed of all biopsied pancreatobiliary strictures at our institution over 5 years. UroVysion was unquestionably the most sensitive method and all methods were highly specific. Sensitivity was highest while maintaining specificity when a malignant interpretation was limited to cases with 5+ cells with the same polysomic signal pattern and/or loss of one or both 9p21 signals. Only UroVysion detected the metastases and a neuroendocrine tumor. In reviewing and analyzing the signal patterns, we noticed trends according to location and diagnosis. Herein we describe our method for analyzing signal patterns and propose cutoff criteria based upon observations gleaned from such analysis.
EGFR‐mutated stage IV non‐small cell lung cancer: What is the role of radiotherapy combined with TKI?
Authors: Liu Bailong , Liu Hui , Ma Yunfei , Ding Qiuhui , Zhang Min , Liu Xinliang , Liu Min 
Published: August 2021

AbstractLung cancer is the leading cause of cancer‐related death globally and poses a considerable threat to public health. Asia has the highest prevalence of epidermal growth factor receptor (EGFR) mutations in patients with non‐small cell lung cancer (NSCLC). Despite the reasonable response and prolonged survival associated with EGFR‐tyrosine kinase inhibitor (TKI) therapy, the acquisition of resistance to TKIs remains a major challenge. Additionally, patients with EGFR mutations are at a substantially higher risk of brain metastasis compared with those harboring wild‐type EGFR. The role of radiotherapy (RT) in EGFR‐mutated (EGFRm) stage IV NSCLC requires clarification, especially with the advent of next‐generation TKIs, which are more potent and exhibit greater central nervous system activity. In particular, the feasible application of RT, including the timing, site, dose, fraction, and combination with TKI, merits further investigation. This review focuses on these key issues, and provides a flow diagram with proposed treatment options for metastatic EGFRm NSCLC, aiming to provide guidance for clinical practice.
Biosynthesis of the Fungal Organophosphonate Fosfonochlorin Involves an Iron(II) and 2‐(Oxo)glutarate Dependent Oxacyclase
Authors: Gama Simanga R. , Stankovic Toda , Hupp Kendall , Al Hejami Ahmed , McClean Mimi , Evans Alysa , Beauchemin Diane , Hammerschmidt Friedrich , Pallitsch Katharina , Zechel David L. 
Published: August 2021

AbstractThe fungal metabolite Fosfonochlorin features a chloroacetyl moiety that is unusual within known phosphonate natural product biochemistry. Putative biosynthetic genes encoding Fosfonochlorin in Fusarium and Talaromyces spp. were investigated through reactions of encoded enzymes with synthetic substrates and isotope labelling studies. We show that the early biosynthetic steps for Fosfonochlorin involve the reduction of phosphonoacetaldehyde to form 2‐hydroxyethylphosphonic acid, followed by oxidative intramolecular cyclization of the resulting alcohol to form (S)‐epoxyethylphosphonic acid. The latter reaction is catalyzed by FfnD, a rare example of a non‐heme iron/2‐(oxo)glutarate dependent oxacyclase. In contrast, FfnD behaves as a more typical oxygenase with ethylphosphonic acid, producing (S)‐1‐hydroxyethylphosphonic acid. FfnD thus represents a new example of a ferryl generating enzyme that can suppress the typical oxygen rebound reaction that follows abstraction of a substrate hydrogen by a ferryl oxygen, thereby directing the substrate radical towards a fate other than hydroxylation.
Tetramethylpyrazine induces the release of BDNF from BM‐MSCs through activation of the PI3K/AKT/CREB pathway
Authors: Chen Bo , An Jing , Guo Yun‐Shan , Tang Juan , Zhao Jing‐Jing , Zhang Rui , Yang Hao 
Published: August 2021

AbstractCompelling evidences suggest that transplantation of bone marrow‐derived mesenchymal stem cells (BM‐MSCs) can be therapeutically effective for central nervous system (CNS) injuries and neurodegenerative diseases. The therapeutic effect of BM‐MSCs mainly attributes to their differentiation into neuron‐like cells which replace injured and degenerative neurons. Importantly, the neurotrophic factors released from BM‐MSCs can also rescue injured and degenerative neurons, which plays a biologically pivotal role in enhancing neuroregeneration and neurological functional recovery. Tetramethylpyrazine (TMP), the main bioactive ingredient extracted from the traditional Chinese medicinal herb Chuanxiong, has been reported to promote the neuronal differentiation of BM‐MSCs. This study aimed to investigate whether TMP regulates the release of neurotrophic factors from BM‐MSCs. We examined the effect of TMP on brain‐derived neurotrophic factor (BDNF) released from BM‐MSCs and elucidated the underlying molecular mechanism. Our results demonstrated that TMP at concentrations of lower than 200 μM increased the release of BDNF in a dose‐dependent manner. Furthermore, the effect of TMP on increasing the release of BDNF from BM‐MSCs was blocked by inhibiting the phosphatidylinositol‐4,5‐bisphosphate 3‐kinase (PI3K)/protein kinase B (AKT)/cAMP‐response element binding protein (CREB) pathway. Therefore, we concluded that TMP could induce the release of BDNF from BM‐MSCs through activation of the PI3K/AKT/CREB pathway, leading to the formation of neuroprotective and proneurogenic microenvironment. These findings suggest that TMP possesses novel therapeutic potential to promote neuroprotection and neurogenesis through improving the neurotrophic ability of BM‐MSCs, which provides a promising nutritional prevention and treatment strategy for CNS injuries and neurodegenerative diseases via the transplantation of TMP‐treated BM‐MSCs.
Cultured human skeletal muscle satellite cells exhibit characteristics of mesenchymal stem cells and play anti‐inflammatory roles through prostaglandin E2 and hepatocyte growth factors
Authors: Kim Seongyup , Jung Pil Young , Lee Jin Suk , Hwang Soonjae , Sohn Joon Hyung , Yoon Yongdae , Bae Keum Seok , Eom Young Woo 
Published: August 2021

AbstractSkeletal muscle satellite cells (SkMSCs) play crucial roles in muscle fiber maintenance, repair, and remodeling; however, it remains unknown if these properties are preserved in cultured SkMSCs. In this study, we investigated the characteristics of cultured SkMSCs and their ability to regulate the activity of M1 macrophages. SkMSCs grew well with an average population doubling time of 26.26 ± 6.85 h during 10 passages (P). At P5, Pax7, MyoD, cluster of differentiation (CD)34, and CD56 were not expressed in SkMSCs, but the MSC markers CD73, CD105, and CD90 were expressed and the cells were differentiated into adipocytes and osteoblasts. When SkMSCs were cocultured with macrophages, interleukin (IL)‐1β secretion was decreased, prostaglandin (PG)E2 was produced in coculture, and cyclooxygenase‐2 protein was induced in an SkMSC‐dependent manner. Hepatocyte growth factor (HGF) was highly secreted by monocultured SkMSCs; interferon‐γ and lipopolysaccharide reduced its expression level. However, HGF expression recovered when SkMSCs and macrophages were cocultured. Although exogenous PGE2 upregulated macrophage pro‐IL‐1β expression, it suppressed the secretion of cleaved IL‐1β. In contrast, HGF decreased active IL‐1β secretion without affecting pro‐IL‐1β expression. Co‐treatment of macrophages with HGF and PGE2 reduced pro‐IL‐1β expression level and active IL‐1β secretion. Our results suggest that SkMSCs lose their satellite cell properties during serial passaging but acquire mesenchymal stem cell properties including the ability to exert an anti‐inflammatory response for macrophages through PGE2 and HGF.
Revealing the Effect of Nickel Nanoparticles for Li Plating and Stripping Processes on Ni−Nx Doped Hollow Carbon Sphere
Authors: Liu Ting , Huang Ying , Zhou Shengqi , Wang Runtong , Lei Jie , Xu Pan , Yuan Ruming , Dong Quanfeng , Chen Jiajia 
Published: August 2021

AbstractIn this work, the effects of the coexistence of Ni−Nx sites and Ni metal nanoparticles of Ni−N−C (nickel‐nitrogen‐carbon) materials on the thermodynamic Li nucleation overpotential (η) and kinetic exchange current density (j0) are systematically studied. Ni‐Nx sites guarantee reduced nucleation resistance on the hollow carbon sphere (HCS) host, while the low amount residual of Ni nanoparticles plays an adverse role. The Li nucleation overpotential was down to 10.6 mV and the exchange current density increased from 1.139 to 2.325 mA cm−2 when the residual Ni nanoparticles in the prepared Ni−N−C composite were removed. As a result, pure Ni‐Nx sites displayed an average CE of 98.4 % over 300 cycles and a stable Li plating/stripping behavior for over 800 h.
A Chiral Molecular Cage Comprising Diethynylallenes and N‐Heterotriangulenes for Enantioselective Recognition
Authors: Míguez‐Lago Sandra , Gliemann Bettina D. , Kivala Milan , Cid María Magdalena 
Published: August 2021

AbstractChirality, a characteristic tool of molecular recognition in nature, is often a complement of redox active systems. Scientists, in their eagerness to mimic such sophistication, have designed numerous chiral systems based on molecular entities with cavities, such as macrocycles and cages. In an attempt to combine chirality and redox‐active species, in this contribution we report the synthesis and detailed characterization of a chiral shape‐persistent molecular cage based on the combination of enantiopure diethynylallenes and electron‐rich bridged triarylamines, also known as N‐heterotriangulenes. Its ability for chiral recognition in solution was revealed through UV/vis titrations with enantiopure helicenes.