bluuebunny/crossref_metadata_2025 huggingface dataset:
Analyse quantitativer Partikelaufnahme von Zellen über verschiedene Messmethoden
Authors: Ashraf Sumaira , Hassan Said Alaa , Hartmann Raimo , Assmann Marcus‐Alexander , Feliu Neus , Lenz Peter , Parak Wolfgang J.
Published: October 2019

Im letzten Jahrzehnt gab es eine große Anzahl publizierter zweidimensionaler und zeitunabhängiger In‐vitro‐Studien über die Aufnahme kolloidaler Nano‐ und Mikropartikel in Zellen. In diesem Kurzaufsatz werden unterschiedliche angewandte Methoden solcher Untersuchungen zusammengefasst und kritisch diskutiert. Ergänzende experimentelle Daten erlauben einen direkten Vergleich zwischen diesen angewandten Techniken. Das Hauptaugenmerk wird darauf liegen, quantitative Parameter aus solchen Studien zu gewinnen, in denen mehrere verschiedene experimentelle Messmethoden genutzt wurden, mit dem Ziel eine bessere Vergleichbarkeit der Daten zu gewährleisten.
Nanographene: ultrastabile, schaltbare und helle Sonden für die hochauflösende Mikroskopie
Authors: Liu Xiaomin , Chen Shih‐Ya , Chen Qiang , Yao Xuelin , Gelléri Márton , Ritz Sandra , Kumar Sachin , Cremer Christoph , Landfester Katharina , Müllen Klaus , Parekh Sapun H. , Narita Akimitsu , Bonn Mischa
Published: October 2019

Die hochauflösende Fluoreszenzmikroskopie hat viele wichtige Entdeckungen in der Biologie und den Materialwissenschaften ermöglicht. Die Implementierungen der hochauflösenden Fluoreszenzmikroskopie, wie die Einzelmolekül‐Lokalisationsmikroskopie (SMLM) und die Minimalemissionsfluss‐Mikroskopie (MINFLUX) im Lokalisierungsmodus, nutzen Fluorophore, die blinken, d. h. stochastisch ein‐ und ausgeschaltet werden. Hier präsentieren wir Nanographene – große polyzyklische aromatische Kohlenwasserstoffe, die auch als atomar präzise Graphenquantenpunkte betrachtet werden können – als eine neue Klasse von Fluorophoren für die hochauflösende Fluoreszenzmikroskopie. Nanographene weisen hervorragende photophysikalische Eigenschaften auf: intrinsisches Blinken auch an Luft, ausgezeichnete Fluoreszenzrückgewinnung und Stabilität über mehrere Monate. Als Eignungsnachweis für hochauflösende Anwendungen verwenden wir Nanographene in SMLM, um hochaufgelöste 3D‐Bilder von Siliciumdioxid‐Nanorissen zu erzeugen. Unsere Ergebnisse öffnen die Tür für die breite Anwendung von Nanographen in der hochauflösenden Fluoreszenzmikroskopie.
A Nanoscale Metal–Organic Framework to Mediate Photodynamic Therapy and Deliver CpG Oligodeoxynucleotides to Enhance Antigen Presentation and Cancer Immunotherapy
Authors: Ni Kaiyuan , Luo Taokun , Lan Guangxu , Culbert August , Song Yang , Wu Tong , Jiang Xiaomin , Lin Wenbin
Published: October 2019

Checkpoint blockade immunotherapy (CBI) awakes a host innate immune system and reactivates cytotoxic T cells to elicit durable response in some cancer patients. Now, a cationic nanoscale metal–organic framework, W‐TBP, is used to facilitate tumor antigen presentation by enabling immunogenic photodynamic therapy (PDT) and promoting the maturation of dendritic cells (DCs). Comprised of dinuclear WVI secondary building units and photosensitizing 5,10,15,20‐tetra(p‐benzoato)porphyrin (TBP) ligands, cationic W‐TBP mediates PDT to release tumor associated antigens and delivers immunostimulatory CpG oligodeoxynucleotides to DCs. The enhanced antigen presentation synergizes with CBI to expand and reinvigorate cytotoxic T cells, leading to superb anticancer efficacy and robust abscopal effects with >97 % tumor regression in a bilateral breast cancer model.
Characterization of Radical SAM Adenosylhopane Synthase, HpnH, which Catalyzes the 5′‐Deoxyadenosyl Radical Addition to Diploptene in the Biosynthesis of C35 Bacteriohopanepolyols
Authors: Sato Shusuke , Kudo Fumitaka , Rohmer Michel , Eguchi Tadashi
Published: October 2019

Adenosylhopane is a crucial intermediate in the biosynthesis of bacteriohopanepolyols, which are widespread prokaryotic membrane lipids. Herein, it is demonstrated that reconstituted HpnH, a putative radical S‐adenosyl‐l‐methionine (SAM) enzyme, commonly encoded in the hopanoid biosynthetic gene cluster, converts diploptene into adenosylhopane in the presence of SAM, flavodoxin, flavodoxin reductase, and NADPH. NMR spectra of the enzymatic reaction product were identical to those of synthetic (22R)‐adenosylhopane, indicating that HpnH catalyzes stereoselective C−C formation between C29 of diploptene and C5′ of 5′‐deoxyadenosine. Further, the HpnH reaction in D2O‐containing buffer revealed that a D atom was incorporated at the C22 position of adenosylhopane. Based on these results, we propose a radical addition reaction mechanism catalyzed by HpnH for the formation of the C35 bacteriohopane skeleton.
Elucidating the Electrocatalytic CO2 Reduction Reaction over a Model Single‐Atom Nickel Catalyst
Authors: Liu Song , Yang Hong Bin , Hung Sung‐Fu , Ding Jie , Cai Weizheng , Liu Linghui , Gao Jiajian , Li Xuning , Ren Xinyi , Kuang Zhichong , Huang Yanqiang , Zhang Tao , Liu Bin
Published: October 2019

Designing effective electrocatalysts for the carbon dioxide reduction reaction (CO2RR) is an appealing approach to tackling the challenges posed by rising CO2 levels and realizing a closed carbon cycle. However, fundamental understanding of the complicated CO2RR mechanism in CO2 electrocatalysis is still lacking because model systems are limited. We have designed a model nickel single‐atom catalyst (Ni SAC) with a uniform structure and well‐defined Ni‐N4 moiety on a conductive carbon support with which to explore the electrochemical CO2RR. Operando X‐ray absorption near‐edge structure spectroscopy, Raman spectroscopy, and near‐ambient X‐ray photoelectron spectroscopy, revealed that Ni+ in the Ni SAC was highly active for CO2 activation, and functioned as an authentic catalytically active site for the CO2RR. Furthermore, through combination with a kinetics study, the rate‐determining step of the CO2RR was determined to be *CO2−+H+→*COOH. This study tackles the four challenges faced by the CO2RR; namely, activity, selectivity, stability, and dynamics.
Zeolite‐Encaged Single‐Atom Rhodium Catalysts: Highly‐Efficient Hydrogen Generation and Shape‐Selective Tandem Hydrogenation of Nitroarenes
Authors: Sun Qiming , Wang Ning , Zhang Tianjun , Bai Risheng , Mayoral Alvaro , Zhang Peng , Zhang Qinghong , Terasaki Osamu , Yu Jihong
Published: October 2019

Single‐atom catalysts are emerging as a new frontier in heterogeneous catalysis because of their maximum atom utilization efficiency, but they usually suffer from inferior stability. Herein, we synthesized single‐atom Rh catalysts embedded in MFI‐type zeolites under hydrothermal conditions and subsequent ligand‐protected direct H2 reduction. Cs‐corrected scanning transmission electron microscopy and extended X‐ray absorption analyses revealed that single Rh atoms were encapsulated within 5‐membered rings and stabilized by zeolite framework oxygen atoms. The resultant catalysts exhibited excellent H2 generation rates from ammonia borane (AB) hydrolysis, up to 699 min−1 at 298 K, representing the top level among heterogeneous catalysts for AB hydrolysis. The catalysts also showed superior catalytic performance in shape‐selective tandem hydrogenation of various nitroarenes by coupling with AB hydrolysis, giving >99 % yield of corresponding amine products.
Discriminative Detection of Biothiols by Electron Paramagnetic Resonance Spectroscopy using a Methanethiosulfonate Trityl Probe
Authors: Tan Xiaoli , Ji Kaiyun , Wang Xing , Yao Ru , Han Guifang , Villamena Frederick A. , Zweier Jay L. , Song Yuguang , Rockenbauer Antal , Liu Yangping
Published: October 2019

Biothiols, such as glutathione (GSH), homocysteine (Hcy), and cysteine (Cys), coexist in biological systems with diverse biological roles. Thus, analytical techniques that can detect, quantify, and distinguish between multiple biothiols are desirable but challenging. Herein, we demonstrate the simultaneous detection and quantitation of multiple biothiols, including up to three different biothiols in a single sample, using electron paramagnetic resonance (EPR) spectroscopy and a trityl‐radical‐based probe (MTST). We term this technique EPR thiol‐trapping. MTST could trap thiols through its methanethiosulfonate group to form the corresponding disulfide conjugate with an EPR spectrum characteristic of the trapped thiol. MTST was used to investigate effects of l‐buthionine sulfoximine (BSO) and pyrrolidine dithiocarbamate (PDTC) on the efflux of GSH and Cys from HepG2 cells.
Development and Investigation of a NASICON‐Type High‐Voltage Cathode Material for High‐Power Sodium‐Ion Batteries
Authors: Chen Mingzhe , Hua Weibo , Xiao Jin , Cortie David , Guo Xiaodong , Wang Enhui , Gu Qinfen , Hu Zhe , Indris Sylvio , Wang Xiao‐Lin , Chou Shu‐Lei , Dou Shi‐Xue
Published: October 2019

Herein, we introduce a 4.0 V class high‐voltage cathode material with a newly recognized sodium superionic conductor (NASICON)‐type structure with cubic symmetry (space group P213), Na3V(PO3)3N. We synthesize an N‐doped graphene oxide‐wrapped Na3V(PO3)3N composite with a uniform carbon coating layer, which shows excellent rate performance and outstanding cycling stability. Its air/water stability and all‐climate performance were carefully investigated. A near‐zero volume change (ca. 0.40 %) was observed for the first time based on in situ synchrotron X‐ray diffraction, and the in situ X‐ray absorption spectra revealed the V3.2+/V4.2+ redox reaction with high reversibility. Its 3D sodium diffusion pathways were demonstrated with distinctive low energy barriers. Our results indicate that this high‐voltage NASICON‐type Na3V(PO3)3N composite is a competitive cathode material for sodium‐ion batteries and will receive more attention and studies in the future.
Quantitative Particle Uptake by Cells as Analyzed by Different Methods
Authors: Ashraf Sumaira , Hassan Said Alaa , Hartmann Raimo , Assmann Marcus‐Alexander , Feliu Neus , Lenz Peter , Parak Wolfgang J.
Published: October 2019

There is a large number of two‐dimensional static in vitro studies about the uptake of colloidal nano‐ and microparticles, which has been published in the last decade. In this Minireview, different methods used for such studies are summarized and critically discussed. Supplementary experimental data allow for a direct comparison of the different techniques. Emphasis is given on how quantitative parameters can be extracted from studies in which different experimental techniques have been used, with the goal of allowing better comparison.
Nanographenes: Ultrastable, Switchable, and Bright Probes for Super‐Resolution Microscopy
Authors: Liu Xiaomin , Chen Shih‐Ya , Chen Qiang , Yao Xuelin , Gelléri Márton , Ritz Sandra , Kumar Sachin , Cremer Christoph , Landfester Katharina , Müllen Klaus , Parekh Sapun H. , Narita Akimitsu , Bonn Mischa
Published: October 2019

Super‐resolution fluorescence microscopy has enabled important breakthroughs in biology and materials science. Implementations such as single‐molecule localization microscopy (SMLM) and minimal emission fluxes (MINFLUX) microscopy in the localization mode exploit fluorophores that blink, i.e., switch on and off, stochastically. Here, we introduce nanographenes, namely large polycyclic aromatic hydrocarbons that can also be regarded as atomically precise graphene quantum dots, as a new class of fluorophores for super‐resolution fluorescence microscopy. Nanographenes exhibit outstanding photophysical properties: intrinsic blinking even in air, excellent fluorescence recovery, and stability over several months. As a proof of concept for super‐resolution applications, we use nanographenes in SMLM to generate 3D super‐resolution images of silica nanocracks. Our findings open the door for the widespread application of nanographenes in super‐resolution fluorescence microscopy.
Ultrafast Condensation of Carbon Nitride on Electrodes with Exceptional Boosted Photocurrent and Electrochemiluminescence
Authors: Zhao Tingting , Zhou Qing , Lv Yanqin , Han Dan , Wu Kaiqing , Zhao Lufang , Shen Yanfei , Liu Songqin , Zhang Yuanjian
Published: October 2019

Semiconducting polymeric carbon nitride (CN) has drawn wide attention ranging from photocatalysis to more recent biosensing owing to unique defect‐tolerated optoelectronic properties and being metal‐free, cheap, and highly stable. However, at the core of electrical–optical interconversion, the preparation of the CN photoelectrode is still challenging. Now, the growth of CN on electrodes is achieved simply by microwave‐assisted condensation in seconds. The ultrafast heating not only addressed the thermodynamic contradiction of precursor volatilization during polymerization but also led to strongly adhesive CN layer on electrodes with gradient carbon‐rich texture, greatly accelerating the electron–hole separation and mobility. Consequently, the CN photoelectrode exhibited a remarkable photocurrent and a record cathodic efficiency of electrochemiluminescence up to 7 times that of benchmark Ru(bpy)3Cl2in aqueous solution.
Bioassay of ferulic acid derivatives as influenza neuraminidase inhibitors
Authors: Cui Man‐Ying , Xiao Meng‐Wu , Xu Lv‐Jie , Chen Yun , Liu Ai‐Lin , Ye Jiao , Hu Ai‐Xi
Published: October 2019

Four series of ferulic acid derivatives were designed, synthesized, and evaluated for their neuraminidase (NA) inhibitory activities against influenza virus H1N1 in vitro. The pharmacological results showed that the majority of the target compounds exhibited moderate influenza NA inhibitory activity, which was also better than that of ferulic acid. The two most potent compounds were 1m and 4a with IC50 values of 12.77 ± 0.47 and 12.96 ± 1.34 μg/ml, respectively. On the basis of the biological results, a preliminary structure–activity relationship (SAR) was derived and discussed. Besides, molecular docking was performed to study the possible interactions of compounds 1p, 2d, 3b, and 4a with the active site of NA. It was found that the 4‐OH‐3‐OMe group and the amide group (CON) of ferulic acid amide derivatives were two key pharmacophores for NA inhibitory activity. It is meaningful to further modify the natural product ferulic acid to improve its influenza NA inhibitory activity.
Differential profiles of response inhibition deficit between male children with autism spectrum disorders and schizophrenia
Authors: Shi Li‐juan , Zhou Han‐yu , Shen Yan‐mei , Wang Ya , Fang Yu‐min , He Yu‐qiong , Ou Jian‐jun , Luo Xue‐rong , Cheung Eric F. C. , Chan Raymond C. K.
Published: October 2019

Autism spectrum disorders (ASD) and schizophrenia (SZ) are both associated with response inhibition impairment. However, the relative pattern of deficits in these two disorders remains unclear. Twenty‐three male children with ASD, 23 male children with SZ, and 32 typically developing male controls were recruited to complete a set of tasks measuring response inhibition in the visual, auditory, and verbal domains. We found that visual, auditory, and verbal response inhibitions were impaired in both children with ASD and children with SZ. Compared with typically developing controls, children with ASD made more commission errors whereas children with SZ responded much slower in the visual response inhibition task. Both clinical groups showed comparable impairment in verbal response inhibition, but children with SZ were more impaired in auditory response inhibition than children with ASD. These different patterns of response inhibition deficit between male children with ASD and SZ may help to differentiate between these two disorders and may be potential targets for intervention. Autism Res 2020, 13: 591–602. © 2019 International Society for Autism Research, Wiley Periodicals, Inc.

Lay Summary

In this study, we found that male children with autism spectrum disorder (ASD) made more commission errors whereas male children with schizophrenia (SZ) responded much slower in the visual response inhibition task. Both clinical groups exhibited comparable impairments in verbal response inhibition, but male children with SZ were more impaired in auditory response inhibition than male children with ASD. Our findings provide potential targets for intervention.
Preparative and Kinetic Analysis of β‐1,4‐ and β‐1,3‐Glucan Phosphorylases Informs Access to Human Milk Oligosaccharide Fragments and Analogues Thereof
Authors: Singh Ravindra Pal , Pergolizzi Giulia , Nepogodiev Sergey A. , de Andrade Peterson , Kuhaudomlarp Sakonwan , Field Robert A.
Published: October 2019

The enzymatic synthesis of oligosaccharides depends on the availability of suitable enzymes, which remains a limitation. Without recourse to enzyme engineering or evolution approaches, herein we demonstrate the ability of wild‐type cellodextrin phosphorylase (CDP: β‐1,4‐glucan linkage‐dependent) and laminaridextrin phosphorylase (Pro_7066: β‐1,3‐glucan linkage‐dependent) to tolerate a number of sugar‐1‐ phosphate substrates, albeit with reduced kinetic efficiency. In spite of catalytic efficiencies of <1 % of the natural reactions, we demonstrate the utility of given phosphorylase–sugar phosphate pairs to access new‐to‐nature fragments of human milk oligosaccharides, or analogues thereof, in multi‐milligram quantities.
Isoindoline‐Based Nitroxides as Bioresistant Spin Labels for Protein Labeling through Cysteines and Alkyne‐Bearing Noncanonical Amino Acids
Authors: Braun Theresa Sophie , Widder Pia , Osswald Uwe , Groß Lina , Williams Lara , Schmidt Moritz , Helmle Irina , Summerer Daniel , Drescher Malte
Published: October 2019

Electron paramagnetic resonance (EPR) spectroscopy in combination with site‐directed spin labeling (SDSL) is a powerful tool in protein structural research. Nitroxides are highly suitable spin labeling reagents, but suffer from limited stability, particularly in the cellular environment. Herein we present the synthesis of a maleimide‐ and an azide‐modified tetraethyl‐shielded isoindoline‐based nitroxide (M‐ and Az‐TEIO) for labeling of cysteines or the noncanonical amino acid para‐ethynyl‐l‐phenylalanine (pENF). We demonstrate the high stability of TEIO site‐specifically attached to the protein thioredoxin (TRX) against reduction in prokaryotic and eukaryotic environments, and conduct double electron–electron resonance (DEER) measurements. We further generate a rotamer library for the new residue pENF‐Az‐TEIO that affords a distance distribution that is in agreement with the measured distribution.
A Genetically Encoded Diazirine Analogue for RNA–Protein Photo‐crosslinking
Authors: Dziuba Dmytro , Hoffmann Jan‐Erik , Hentze Matthias W. , Schultz Carsten
Published: October 2019

Ultraviolent crosslinking is a key experimental step in the numerous protocols that have been developed for capturing and dissecting RNA–protein interactions in living cells. UV crosslinking covalently stalls dynamic interactions between RNAs and the directly contacting RNA‐binding proteins and enables stringent denaturing downstream purification conditions needed for the enrichment and biochemical analysis of RNA–protein complexes. Despite its popularity, conventional 254 nm UV crosslinking possesses a set of intrinsic drawbacks, with the low photochemical efficiency being the central caveat. Here we show that genetically encoded photoreactive unnatural amino acids bearing a dialkyl diazirine photoreactive group can address this problem. Using the human iron regulatory protein 1 (IRP1) as a model RNA‐binding protein, we show that the photoreactive amino acids can be introduced into the protein without diminishing its RNA‐binding properties. A sevenfold increase in the crosslinking efficiency compared to conventional 254 nm UV crosslinking was achieved using the diazirine‐based unnatural amino acid DiAzKs. This finding opens an avenue for new applications of the unnatural amino acids in studying RNA–protein interactions.
Ascorbate Oxidase Mimetic Activity of Copper(II) Oxide Nanoparticles
Authors: He Shao‐Bin , Hu Ai‐Ling , Zhuang Quan‐Quan , Peng Hua‐Ping , Deng Hao‐Hua , Chen Wei , Hong Guo‐Lin
Published: October 2019

Although oxidase mimetic nanozymes have been widely investigated, specific biological molecules have rarely been explored as substrates, particularly in the case of ascorbate oxidase (AAO) mimetic nanozymes. Herein, we demonstrate for the first time that copper(II) oxide nanoparticles (CuO NPs) catalyze the oxidation of ascorbic acid (AA) by dissolved O2 (as a green oxidant) to form dehydroascorbic acid (DHAA), thus functioning as a new kind of AAO mimic. Under neutral conditions, the Michaelis–Menten constant of CuO NPs (0.1302 mm) is similar to that of AAO (0.0840 mm). Furthermore, the robustness of CuO NPs is greater than that of AAO, thus making them suitable for applications under various conditions. As a demonstration, a fluorescence AA sensor based on the AAO mimetic activity of CuO NPs was developed. To obtain a fluorescent product, o‐phenylenediamine (OPDA) was used to react with the DHAA produced by the oxidation of AA catalyzed by CuO NPs. The developed sensor was cost‐effective and easy to fabricate and exhibited high selectivity/sensitivity with a wide linear range (1.25×10−6 to 1.125×10−4 m) and a low detection limit (3.2×10−8 m). The results are expected to aid in expanding the applicability of oxidase mimetic nanozymes in a variety of fields such as biology, medicine, and detection science.
Photoelectrochemical CO2 Reduction to Formate with the Sacrificial Reagent Free System of Semiconductor Photocatalysts and Formate Dehydrogenase
Authors: Ishibashi Tomoya , Higashi Masanobu , Ikeda Shigeru , Amao Yutaka
Published: October 2019

Efficient sacrificial reagent free (and no external bias) photoelectrochemical CO2 reduction to formate with a hybrid system consisting of semiconductor‐based photocatalytic TiO2 nanoparticles, methylviologen (MV) as an electron carrier, and biocatalytic formate dehydrogenase (FDH) was investigated. To develop the sacrificial reagent free photoelectrochemical cell for the CO2 reduction to formate, the photoanode based on TiO2 film and cathode based on the carbon fabric paper (CFP) were separated into two compartments using a proton‐permeable Nafion film to prevent gas diffusion. When the anode was irradiated with Xenon lamp (>300 nm), MV reduction and CO2 reduction to formate with FDH on the cathode side proceeded in this system. For MV reduction with photoelectrochemical cell, MV was reduced using TiO2 film at each pH (6, 7 and 8) without bias, the reduction of MV did not progressed at pH 6. In contrast, MV reduction was progressed at pH 7 or 8. For CO2 reduction to formate in the presence FDH on the cathode side with photoelectrochemical cell, the rate of formate production was estimated to be 31.9 nmol h−1 at pH 8 under continuous irradiation without bias. Moreover, the rates of formate production at pH 7 and 8 were estimated to be 56.5 and 168.8 nmol h−1, respectively under continuous irradiation with bias (0.4 V vs. cathode). By using this system, we have succeeded in constructing CO2 reduction to formate using water as an electron donor, which does not require a sacrificial reagent.
Iron‐Electrocatalyzed C−H Arylations: Mechanistic Insights into Oxidation‐Induced Reductive Elimination for Ferraelectrocatalysis
Authors: Zhu Cuiju , Stangier Maximilian , Oliveira João C. A. , Massignan Leonardo , Ackermann Lutz
Published: October 2019

Despite major advances, organometallic C−H transformations are dominated by precious 5d and 4d transition metals, such as iridium, palladium and rhodium. In contrast, the unique potential of less toxic Earth‐abundant 3d metals has been underexplored. While iron is the most naturally abundant transition metal, its use in oxidative, organometallic C−H activation has faced major limitations due to the need for superstoichiometric amounts of corrosive, cost‐intensive DCIB as the sacrificial oxidant. To fully address these restrictions, we describe herein the unprecedented merger of electrosynthesis with iron‐catalyzed C−H activation through oxidation‐induced reductive elimination. Thus, ferra‐ and manganaelectro‐catalyzed C−H arylations were accomplished at mild reaction temperatures with ample scope by the action of sustainable iron catalysts, employing electricity as a benign oxidant.
Controlled Synthesis of Ni‐Doped MoS2 Hybrid Electrode for Synergistically Enhanced Water‐Splitting Process
Authors: Wang Ying , Sun Wenming , Ling Xiaofei , Shi Xiangkai , Li Lanlan , Deng Yida , An Cuihua , Han Xiaopeng
Published: October 2019

The development of high‐efficiency, low‐cost, and earth‐abundant electrocatalysts for overall water splitting remains a challenge. In this work, Ni‐modified MoS2 hybrid catalysts are grown on carbon cloth (Ni‐Mo‐S@CC) through a one‐step hydrothermal treatment. The optimized Ni‐Mo‐S@CC catalyst shows excellent hydrogen evolution reaction (HER) activity with a low overpotential of 168 mV at a current density of 10 mA cm−2 in 1.0 m KOH, which is lower than those of Ni‐Mo‐S@CC (1:1), Ni‐Mo‐S@CC (3:1), and pure MoS2. Significantly, the Ni‐Mo‐S@CC hybrid catalyst also displays outstanding oxygen evolution reaction (OER) activity with a low overpotential of 320 mV at a current density of 10 mA cm−2, and remarkable long‐term stability for 30 h at a constant current density of 10 mA cm−2. Experimental results and theoretical analysis based on density functional theory demonstrate that the excellent electrocatalytic performance can be attributed mainly to the remarkable conductivity, abundant active sites, and synergistic effect of the Ni‐doped MoS2. This work sheds light on a unique strategy for the design of high‐performance and stable electrocatalysts for water‐splitting electrolyzers.
Evidence for the Prerequisite Formation of Phenoxyl Radicals in Radical‐Mediated Peptide Tyrosine Nitration In Vacuo
Authors: Lai Cheuk Kuen , Tang Wai Kit , Siu Chi‐Kit , Chu Ivan K.
Published: October 2019

The elementary mechanism of radical‐mediated peptide tyrosine nitration, which is a hallmark of post‐translational modification of proteins under nitrative stress in vivo, has been elucidated in detail by using an integrated approach that combines the gas‐phase synthesis of prototypical molecular tyrosine‐containing peptide radical cations, ion–molecule reactions, and isotopic labeling experiments with DFT calculations. This reaction first involves the radical recombination of .NO2 towards the prerequisite phenoxyl radical tautomer of a tyrosine residue, followed by proton rearrangements, finally yielding the stable and regioselective 3‐nitrotyrosyl residue product. In contrast, nitration with the π‐phenolic radical cation tautomer is inefficient. This first direct experimental evidence for the elementary steps of the radical‐mediated tyrosine nitration mechanism in the gas phase provides a fundamental insight into the regioselectivity of biological tyrosine ortho‐nitration.
Spirobifluorene‐Based o‐Carboranyl Compounds: Insights into the Rotational Effect of Carborane Cages on Photoluminescence
Authors: Kim Seonah , Lee Ji Hye , So Hyunhee , Ryu Jiyeon , Lee Junseong , Hwang Hyonseok , Kim Youngjo , Park Myung Hwan , Lee Kang Mun
Published: October 2019

9,9′‐Spirobifluorene‐based closo‐o‐carboranyl (SFC1 and SFC2) compounds and their nido‐derivatives (nido‐SFC1 and nido‐SFC2) were prepared and characterized. The two closo‐compounds displayed major absorption bands assignable to π–π* transitions involving the spirobifluorene group, as well as weak intramolecular charge‐transfer (ICT) transitions between the o‐carboranes and their spirobifluorene moieties. The nido‐compounds exhibited slightly blueshifted absorption bands resulting from the absence of the ICT transitions corresponding to the o‐carborane moieties due to the anionic character of the nido‐o‐carboranes. While SFC1 exhibited only high‐energy emissions in THF at 298 K (only from locally excited (LE) states assignable to π–π* transitions on the spirobifluorene group), remarkable emissions in the low‐energy region were observed in the rigid state such as in THF at 77 K and in the film state. SFC2 displayed intense emissions in the low‐energy region in all states. The fact that neither of the nido‐derivatives of SFC1 and SFC2 exhibited low‐energy emissions and the TD‐DFT calculation results of each closo‐compound clearly verified that the low‐energy emission was based on ICT‐based radiative decay. The conformational barriers from each relative energy calculation upon changing the dihedral angles around the o‐carborane cages for both compounds confirmed that the rotation of the o‐carborane cages and terminal phenyl rings for SFC1 is freer than that for SFC2.
Consecutive Supramolecular Polymerization of a Rylene‐Based Twistacene
Authors: Martínez Manuel A. , Greciano Elisa E. , Sánchez Luis
Published: October 2019

The synthesis and self‐assembling features of twistacene 1 are reported. The supramolecular polymerization of 1 displays a consecutive pathway to afford slipped (AggI) and rotationally displaced (AggII) aggregates conditioned by the formation of intramolecularly H‐bonded pseudocycles. In methylcyclohexane, both AggI and AggII are highly stable and the interconversion of the kinetically controlled AggI into the thermodynamically controlled AggII takes several weeks to occur. The utilization of toluene as solvent changes the energetic level for both aggregates and favors a faster conversion of AggI into AggII within a period of minutes. This conversion can be accelerated by the addition of seeds. Furthermore, concentration dependent kinetic studies demonstrate the consecutive character of the supramolecular polymerization of 1.
Azaacene Dimers: Acceptor Materials with a Twist
Authors: Ahrens Lukas , Butscher Julian , Brosius Victor , Rominger Frank , Freudenberg Jan , Vaynzof Yana , Bunz Uwe H. F.
Published: October 2019

The synthesis of five spiro‐linked azaacene dimers is reported and their properties are compared to that of their monomers. Dimerization quenches emission of the longer (≥(hetero)tetracenes) derivatives and furnishes amorphous thin‐films, the absorption is not affected. The larger derivatives were tested as acceptors in bulk‐heterojunction photovoltaic devices with a maximum power conversion efficiency of up to 1.6 %.
Hydrothermally Grown ZnO Nanorods as Promising Materials for Low Cost Electronic Skin
Authors: Fraleoni‐Morgera Alessandro , Cesini Ilaria , Kumar Pramod , Oddo Calogero Maria
Published: October 2019

ZnO nanorods (NRs) are nanomaterials with a wide range of applications (photocatalysis, optoelectronics, catalysis, etc). One peculiar property of ZnO NRs is their piezoelectricity, which opens up a wealth of possibilities in the field of pressure sensors. In fact, thanks also to the recent availability of low cost hydrothermal growth, it is already possible to fabricate flexible, large area, self‐powered, distributed pressure sensors, with a high potential for use in robotics and prosthetics as “electronic skins”. This review focuses hence on ZnO NRs grown by the hydrothermal method, with an eye on the relationship between the reaction parameters and the resulting NRs morphology, and on their specific application in pressure sensing in terms of device design and performance.
Original Suzuki–Miyaura Coupling Using Nitro Derivatives for the Synthesis of Perylenediimide‐Based Multimers
Authors: Rocard Lou , Hatych Danylo , Chartier Thomas , Cauchy Thomas , Hudhomme Piétrick
Published: October 2019

A series of perylenediimide (PDI)‐based multimers were synthesized using an original Suzuki–Miyaura Coupling (SMC) reaction. The new approach considers the reaction between 1‐nitroPDI as the electrophilic reagent with a wide variety of boronic esters to reach PDI dimers, trimers and tetramers which are of particular interest as Non‐Fullerene Acceptors (NFAs) in organic photovoltaics. In this work, we compared the reactivity of 1‐bromoPDI and 1‐nitroPDI towards this pallado‐catalyzed cross‐coupling reaction. Considering that 1‐nitroPDI is more accessible in terms of selectivity, time reaction, purification efficiency, atom economy, etc, we have shown that the use of nitroarenes is largely favored in the preparation of these PDI‐based multimers. The latter were characterized with determination of their spectroscopic and electrochemical properties. With the aim of extending this SMC reaction to N‐annulated PDI analogues, an original and efficient transformation of nitro‐PDI into pyrrole‐fused PDI was found as an alternative to the well‐known reductive Cadogan cyclization. The SMC reaction was applied to bromo and nitro N‐annulated PDI derivatives, and DFT calculations were accomplished in order to clarify the oxidative addition step of the cross‐coupling and understand the difference of reactivity between the bromo‐ and nitro‐PDI based electrophiles.
Recent developments in capillary and microchip electroseparations of peptides (2017–mid 2019)
Authors: Kašička Václav
Published: October 2019

The review presents a comprehensive survey of recent developments and applications of high performance capillary and microchip electroseparation methods (zone electrophoresis, isotachophoresis, isoelectric focusing, affinity electrophoresis, electrokinetic chromatography, and electrochromatography) for analysis, micropreparation, and physicochemical and biochemical characterization of peptides since 2017 up to about the middle of 2019. Progress in the study of electromigration properties of peptides and in the methodology of their analysis (sample preseparation, preconcentration and derivatization, adsorption suppression, EOF control, and detection) are described. Advances in CE and CEC methods are demonstrated and their applications in the following areas are presented: qualitative and quantitative analysis, determination in complex (bio)matrices, monitoring of chemical and enzymatical reactions and physical changes, amino acid, sequence and chiral analysis, and peptide mapping of proteins. In addition, micropreparative separations and determinations of important physicochemical characteristics of peptides by CE and CEC methods are reported.
Pathways to care for people with dementia: An international multicentre study
Authors: Volpe Umberto , Amin Hania , Ayinde Olatunde O. , Burns Alistair , Chan Wai Chi , David Renaud , Dejanovic Slavica Djukic , Djokic Gorica , Eraslan Defne , Fischer Giulia A.L. , Gracia‐García Patricia , Hamdani Syed Usman , Han Changsu , Jafri Hussain , Kallivayalil Roy A. , Kriekaart Roderick Leonard , Kua Ee Heok , Lam Linda C.W. , Lecic‐Tosevski Dusica , Leroi Iracema , Lobo Antonio , Mihai Adriana , Minhas Fareed Aslam , Mistry Heena , Ogundele Afolakemi T. , Olde Rikkert Marcel G.M. , Olivera Javier , Palumbo Claudia , Parker Angela , Pejuskovic Bojana , Riese Florian , Robert Philippe , Semrau Maya , Stoppe Gabriela , Sudhakar Sanu , Tirintica Andreea Raluca , Tofique Sehrish , Tsoi Chris , Wolski Lucas , Yalug Irem , Wang Huali , Yu Xin , Sartorius Norman
Published: October 2019

Objective

The aim of the present study was to characterize the clinical pathways that people with dementia (PwD) in different countries follow to reach specialized dementia care.

Methods

We recruited 548 consecutive clinical attendees with a standardized diagnosis of dementia, in 19 specialized public centres for dementia care in 15 countries. The WHO “encounter form,” a standardized schedule that enables data concerning basic socio‐demographic, clinical, and pathways data to be gathered, was completed for each participant.

Results

The median time from the appearance of the first symptoms to the first contact with specialist dementia care was 56 weeks. The primary point of access to care was the general practitioners (55.8%). Psychiatrists, geriatricians, and neurologists represented the most important second point of access. In about a third of cases, PwD were prescribed psychotropic drugs (mostly antidepressants and tranquillizers). Psychosocial interventions (such as psychological counselling, psychotherapy, and practical advice) were delivered in less than 3% of situations. The analyses of the “pathways diagram” revealed that the path of PwD to receiving care is complex and diverse across countries and that there are important barriers to clinical care.

Conclusions

The study of pathways followed by PwD to reach specialized care has implications for the subsequent course and the outcome of dementia. Insights into local differences in the clinical presentations and the implementation of currently available dementia care are essential to develop more tailored strategies for these patients, locally, nationally, and internationally.
Modelling inter‐annual and spatial variability of ice cover in a temperate lake with complex morphology
Authors: Caramatti Irene , Peeters Frank , Hamilton David , Hofmann Hilmar
Published: October 2019

The formation of ice cover on lakes alters heat and energy transfer with the water column. The fraction of surface area covered by ice and the timing of ice‐on and ice‐off therefore affects hydrodynamics and the seasonal development of stratification and related ecosystem processes. Multi‐year model simulations of temperate lake ecosystems that freeze partially or completely therefore require simulation of the formation and duration of ice cover. Here we present a multi‐year hydrodynamic simulation of an alpine lake with complex morphology (Lower Lake Constance, LLC) using the three‐dimensional (3D) model Aquatic Ecosystem Model (AEM3D) over a period of 9 years. LLC is subdivided into three basins (Gnadensee, Zeller See and Rheinsee) which differ in depth, morphological features, hydrodynamic conditions and ice cover phenology and thickness. Model results were validated with field observations and additional information on ice cover derived from a citizen science approach using information from social media. The model reproduced the occurrence of thin ice as well as its inter‐annual variability and differentiated the frequency and extent of ice cover between the three sub‐basins. It captured that full ice cover occurs almost each winter in Gnadensee, but only rarely in Zeller See and Rheinsee. The results indicate that the 3D model AEM3D is suitable for simulating long‐term dynamics of thin ice cover in lakes with complex morphology and inter‐annual changes in spatially heterogeneous ice cover.
Sustained release of silibinin‐loaded chitosan nanoparticle induced apoptosis in glioma cells
Authors: Alipour Maryam , reza Bigdeli Mohammad , Aligholi Hadi , Rasoulian Bahram , Khaksarian Mojtaba
Published: October 2019

In this study, a chitosan nanoparticle formulation was synthesized for loading silibinin as a sustained‐release drug system to evaluate its effects on apoptosis in C6 glioma cells. This synthesized nanoparticle was analyzed by measurement methods including Fourier transform infrared (FTIR), field emission‐scanning electron microscopy (FE‐SEM), dynamic light scattering (DLS), X‐ray diffraction (XRD), and differential scanning calorimetry (DSC). The formation and amorphization of nanoparticle were confirmed by FTIR and XRD analysis, respectively. The mean diameter of silibinin‐loaded chitosan nanoparticles (SCNP) was 50 ± 7 and 188.6 ± 0.17 nm by using FE‐SEM and DLS, respectively. In addition, the positive zeta potential of nanoparticles was +11.5. Rhodamine‐conjugated SCNP analysis showed the internalization of silibinin to C6 glioma cells. The cytotoxicity assay indicated that the nanoformulation of silibinin was toxic to C6 glioma cells. Although SCNP significantly increased the expression of the both apoptotic genes in C6 cells, Bax and caspase3, it did not have any significant effect on the level of the antiapoptotic gene, Bcl2. In contrast, SCNP did not have any toxic effect on H9C2 cells. In conclusion, the results of the current study indicated that SCNP can be considered as a sustained‐release drug system for future cell‐based therapeutic strategies.
Implementing user‐defined atlas‐based auto‐segmentation for a large multi‐centre organisation: the Australian Experience
Authors: Hu Yunfei , Byrne Mikel , Archibald‐Heeren Ben , Thompson Kenton , Fong Andrew , Knesl Marcel , Teh Amy , Tiong Eve , Foster Richard , Melnyk Paul , Burr Michelle , Thompson Amelia , Lim Jiy , Moore Luke , Gordon Fiona , Humble Rylie , Hardy Anna , Williams Saul
Published: October 2019

Introduction

Contouring has become an increasingly important aspect of radiation therapy due to inverse planning, and yet is extremely time‐consuming. To improve contouring efficiency and reduce potential inter‐observer variation, the atlas‐based auto‐segmentation (ABAS) function in Velocity was introduced to ICON cancer centres (ICC) throughout Australia as a solution for automatic contouring.

Methods

This paper described the implementation process of the ABAS function and the construction of user‐defined atlas sets and compared the contouring efficiency before and after the introduction of ABAS.

Results

The results indicate that the main limitation to the ABAS performance was Velocity's sub‐optimal atlas selection method. Three user‐defined atlas sets were constructed. Results suggested that the introduction of the ABAS saved at least 5 minutes of manual contouring time (P < 0.05), although further verification was required due to limitations in the data collection method. The pilot rollout adopting a ‘champion’ approach was successful and provided an opportunity to improve the user‐defined atlases prior to the national implementation.

Conclusion

The implementation of user‐defined ABAS for head and neck (H&N) and female thorax patients at ICCs was successful, which achieved at least 5 minutes of efficiency gain.
Body‐ and Movement‐Oriented Interventions for Posttraumatic Stress Disorder: A Systematic Review and Meta‐Analysis
Authors: van de Kamp Minke M. , Scheffers Mia , Hatzmann Janneke , Emck Claudia , Cuijpers Pim , Beek Peter J.
Published: October 2019

To assess the efficacy of body‐ and movement‐oriented interventions (BMOIs) in traumatized adults with posttraumatic stress disorder (PTSD), we conducted a systematic review and meta‐analysis of pertinent literature. Four bibliographical databases (PsycINFO, Ovid MEDLINE(R), EMBASE, and the Cochrane Central Register of Controlled Trials) were searched using keywords and text words for trials on BMOIs addressing PTSD. The search included articles published between October 2005 and August 2017. Studies were included if participants were adults suffering from PTSD, if BMOIs were the therapeutic strategy under investigation, and if a psychometrically evaluated standardized outcome measure for PTSD was used. No limitations for control conditions were applied. Hedges’ g was computed as the effect size (ES) for the treatment versus control condition. The meta‐analysis included 15 studies, which resulted in a mean ES of g = 0.85, 95% CI [0.31, 1.39], with very high heterogeneity, I2 = 91%. After removing one study as outlier, a mean effect size of g = 0.56, 95% CI [0.29, 0.82] (i.e., medium effect), still with considerable heterogeneity, I2 = 57%, was found. BMOIs seem to be effective in reducing symptoms of PTSD, but more research is needed to identify working mechanisms and to determine which types of intervention are most effective for various subgroups of patients.
Influence of biodiversity and iron availability on soil peroxide: Implications for soil carbon stabilization and storage
Authors: Yu Guang‐Hui , Sun Fu‐Sheng , Yang Liu , He Xin‐Hua , Polizzotto Matthew L.
Published: October 2019

Intensive agriculture results in soil degradation, especially with the depletion of soil organic carbon (SOC). Application of organic fertilizers (e.g., animal manures) alone or combined with chemical fertilizers can alleviate soil degradation by increasing soil C while causing variations in soil hydrogen peroxide (H2O2) and iron availability. However, the underlying relationships among soil H2O2 production, iron availability, and soil C storage following organic fertilization remain poorly understood. By combining results from three agroecosystem experiments from temperate northern to subtropical southern China with 25–29 years of different fertilization treatments (no fertilization, Control; inorganic nitrogen, phosphorus and potassium fertilization [NPK]; NPK plus manure [NPKM]), here, we show that NPK treatments increased soil H2O2 but decreased biodiversity (i.e., Shannon index) and SOC compared with NPKM treatments across all of the three experiments. In all of the examined soils, the contents of H2O2 were approximately 0.7– to 7–fold higher under NPK treatment than under Control or NPKM treatments. The contents of H2O2 were significantly affected by the fertilization regimes, experimental places, and their interaction. Compared with Control and NPKM treatments, NPK treatment decreased Shannon index to the greatest extent (~1.5) at the Qiyang experiment in subtropical southern China, followed by Jinxian (~0.6) in subtropical southern China, and Gongzhuling (~0.3) in temperate northern China. There was a significant and negative correlation between soil H2O2 and Shannon index or mobilized iron, indicating that high biodiversity and high mobilized iron were beneficial to the decay of soil H2O2. Results from microcosm experiments support the field observations, implying that the occurrence of microbial‐mediated Fenton‐like reactions or free radical reactions was influenced by organic inputs. Together, these findings suggest that long‐term manure inputs to soil initialize free radical reactions by activating microbial communities and mobilizing iron, providing benefits for soil C stabilization and storage by increasing recalcitrance and SOC interactions.
Error correction iterative method for the stationary incompressible MHD flow
Authors: Yang Yun‐Bo , Jiang Yao‐Lin
Published: October 2019

A new iterative finite element method for solving the stationary incompressible magnetohydrodynamics (MHD) equations is derived in this paper. The method consists of two steps at each iteration step, we need first to solve the MHD equations by the Oseen‐type iterative scheme, and then an error correction strategy is applied to control the error arising from the linearization of the nonlinear MHD equations. The new method not only maintains the advantage of the standard Oseen‐type scheme but also possesses a rapid rate of convergence. It is proved that the convergence rate of the proposed method is increased greatly under the uniqueness condition. The uniform stability and convergence of the new scheme are analyzed. Ample numerical experiments are performed to validate the accuracy and the efficiency of the new numerical scheme.
Computational 1H NMR: Part 1. Theoretical background
Authors: Krivdin Leonid
Published: October 2019

This is the first of three closely interrelated reviews prepared for Magnetic Resonance in Chemistry dealing accordingly with theoretical background, chemical applications, and biochemical studies by means of computational 1H NMR. Presented in the first part of the review is a general outline of the modern theoretical methods and accuracy factors of computational 1H NMR involving locally dense basis set schemes, solvent effects, vibrational corrections, and relativistic effects performed at the DFT and/or nonempirical levels. This review is dedicated to Professor Stephan Sauer in view of his invaluable contribution to the field of computational NMR.
Improved algorithms for generalized finite element simulations of three‐dimensional hydraulic fracture propagation
Authors: Shauer Nathan , Duarte Carlos Armando
Published: October 2019

This paper reports improvements to algorithms for the simulation of 3‐D hydraulic fracturing with the Generalized Finite Element Method (GFEM). Three optimizations are presented and analyzed. First, an improved initial guess based on solving a 3‐D elastic problem with the pressure from the previous step is shown to decrease the number of Newton iterations and increase robustness. Second, an improved methodology to find the time step that leads to fracture propagation is proposed and shown to decrease significantly the number of iterations. Third, reduced computational cost is observed by properly recycling the linear part of the coupled stiffness matrix. Two representative examples are used to analyze these improvements. Additionally, a methodology to include the leak‐off term is presented and verified against asymptotic analytical solutions. Conservation of mass is shown to be well satisfied in all examples.