bluuebunny/crossref_metadata_2025_split huggingface dataset:
Advances in Functional Nanomaterials Science
Authors: Rahimi‐Iman Arash 
Published: August 2020

AbstractTechnologies employing nanomaterials, such as electronics, optoelectronics, nanobiotechnologies, quantum optics, and nanophotonics, are perceived as the key drivers of investigations on novel and functional materials and their nanostructures for various applications. It is well understood that the study of such materials and structures has been of great importance for the optimization and development of electrical and optical devices. From such devices, one does not only expect higher efficiencies, but also access to the development of completely new concepts, which are strongly demanded by modern information‐processing, quantum, or medical technologies, and sensing applications. In this context, a wide range of aspects such as the physics of novel materials, as well as materials engineering, characterization, and applications are summarized here. Novel materials, which can be used, for instance, for energy harvesting or light generation, as well as for future logic devices; material engineering, which can lead to improved device functionality and performance in optoelectronics; material physics, the study of which allows insight to be gained into optical and electrical properties of nanostructured systems and quantum materials; and technologies/devices, addressing progress on the application side of sophisticated material systems and quantum structures, are highlighted using representative examples.
Preparation of Nafion Membranes for Reproducible Ammonia Quantification in Nitrogen Reduction Reaction Experiments
Authors: Hanifpour Fatemeh , Sveinbjörnsson Arnar , Canales Camila Pía , Skúlason Egill , Flosadóttir Helga Dögg 
Published: August 2020

AbstractThis study highlights the importance of following a strict protocol for Nafion membrane pretreatment for electrochemical nitrogen reduction reaction experiments. Atmospheric ammonia pollution can be introduced to the experimental setup through membranes and interpreted falsely as catalysis product from N2. The sources of ammonia contamination vary drastically between locations worldwide and even within the same location between days depending on temperature, wind direction, fertilizer use, and manure accumulation in its vicinity. The study shows that significant amounts of ammonium is accumulated in the membranes after commonly practiced pretreatment methods, where the amount depends on the ammonia concentration in the surrounding of the experiment. Therefore, we introduce a new pretreatment method which removes all the ammonium in the membrane. The membranes can be stored for several days but a short final step in the method needs to be carried out right before NRR experiments.
α‐Kationische Phosphole: Synthese und Anwendungen als Liganden
Authors: Johannsen Tim , Golz Christopher , Alcarazo Manuel 
Published: August 2020

AbstractEine Reihe von strukturell unterschiedlichen α‐kationischen Phospholen mit Cyclopropenium‐, Imidazolium‐ und Iminium‐Subsituenten wurde durch die Reaktion von Chlorophosphol 1 mit den entsprechenden stabilen Carbenen synthetisiert. Die Evaluierung der Donor‐Eigenschaften dieser Verbindungen zeigt, dass deren starker π‐Akzeptor‐Charakter deutlich von der Art des kationischen Substituenten abhängig ist. Zusätzlich wurde die Koordinationschemie dieser neuen Liganden mit AuI untersucht und deren einzigartigen elektronischen Eigenschaften in der Katalyse gezeigt. Interessanterweise waren auf α‐kationischen Phospholen basierende Katalysatoren nicht nur in der Lage, die gewählten Cycloisomerisierungsreaktionen zu beschleunigen, sondern auch bei mehreren möglichen Reaktionspfaden einen deutlich zu bevorzugen und so die Bildung unerwünschter Produktgemische zu verhindern.
Reactivity–Stereoselectivity Mapping for the Assembly of Mycobacterium marinum Lipooligosaccharides
Authors: Hansen Thomas , Ofman Tim P. , Vlaming Joey G. C. , Gagarinov Ivan A. , van Beek Jessey , Goté Tessa A. , Tichem Jacoba M. , Ruijgrok Gijs , Overkleeft Herman S. , Filippov Dmitri V. , van der Marel Gijsbert A. , Codée Jeroen D. C. 
Published: August 2020

AbstractThe assembly of complex bacterial glycans presenting rare structural motifs and cis‐glycosidic linkages is significantly obstructed by the lack of knowledge of the reactivity of the constituting building blocks and the stereoselectivity of the reactions in which they partake. We here report a strategy to map the reactivity of carbohydrate building blocks and apply it to understand the reactivity of the bacterial sugar, caryophyllose, a rare C12‐monosaccharide, containing a characteristic tetrasubstituted stereocenter. We mapped reactivity–stereoselectivity relationships for caryophyllose donor and acceptor glycosides by a systematic series of glycosylations in combination with the detection and characterization of different reactive intermediates using experimental and computational techniques. The insights garnered from these studies enabled the rational design of building blocks with the required properties to assemble mycobacterial lipooligosaccharide fragments of M. marinum.
Nitro and Other Electron Withdrawing Group Activated Ruthenium Catalysts for Olefin Metathesis Reactions
Authors: Kajetanowicz Anna , Grela Karol 
Published: August 2020

AbstractAdvanced applications of the Nobel Prize winning olefin metathesis reaction require user‐friendly and highly universal catalysts. From many successful metathesis catalysts, which belong to the two distinct classes of Schrock and Grubbs‐type catalysts, the subclass of chelating‐benzylidene ruthenium complexes (so‐called Hoveyda–Grubbs catalysts) additionally activated by electron‐withdrawing groups (EWGs) provides a highly tunable platform. In the Review, the origin of the EWG‐activation concept and selected applications of the resulting catalysts in target‐oriented synthesis, medicinal chemistry, as well as in the preparation of fine‐chemicals and in materials chemistry is discussed. Based on the examples, some suggestions for end‐users regarding minimization of catalyst loading, selectivity control, and general optimization of the olefin metathesis reaction are provided.
α‐Cationic Phospholes: Synthesis and Applications as Ancillary Ligands
Authors: Johannsen Tim , Golz Christopher , Alcarazo Manuel 
Published: August 2020

AbstractA series of structurally differentiated α‐cationic phospholes containing cyclopropenium, imidazolium, and iminium substituents has been synthesized by reaction of chlorophosphole 1 with the corresponding stable carbenes. Evaluation of the donor properties of these compounds reveals that their strong π‐acceptor character is heavily influenced by the nature of the cationic group. The coordination chemistry of these newly prepared ligands towards AuI centers is also described and their unique electronic properties exploited in catalysis. Interestingly, α‐cationic phosphole containing catalysts were not only able to accelerate model cycloisomerization reactions, but also to efficiently discriminate between concurrent reaction pathways, avoiding the formation of undesired product mixtures.
Highly Selective Olefin Production from CO2 Hydrogenation on Iron Catalysts: A Subtle Synergy between Manganese and Sodium Additives
Authors: Xu Yao , Zhai Peng , Deng Yuchen , Xie Jinglin , Liu Xi , Wang Shuai , Ma Ding 
Published: August 2020

AbstractMn and Na additives have been widely studied to improve the efficiency of CO2 hydrogenation to valuable olefins on Fe catalysts, but their effects on the catalytic properties and mechanism are still under vigorous debate. This study shows that Fe‐based catalysts with moderate Mn and Na contents are highly selective for CO2 hydrogenation to olefins, together with low selectivities for both CO and CH4 and much improved space‐time olefin yields compared to state‐of‐the‐art catalysts. Combined kinetic assessment and quasi in situ characterizations further unveil that the sole presence of Mn suppresses the activity of Fe catalysts because of the close contact between Fe and Mn, whereas the introduction of Na mediates the Fe–Mn interaction and provides strong basic sites. This subtle synergy between Na and Mn sheds light on the importance of the interplay of multiple additives that could bring an enabling strategy to improve catalytic activity and selectivity.
Polymerized Small‐Molecule Acceptors for High‐Performance All‐Polymer Solar Cells
Authors: Zhang Zhi‐Guo , Li Yongfang 
Published: August 2020

AbstractAll‐polymer solar cells (all‐PSCs) have drawn tremendous research interest in recent years, due to their inherent advantages of good film formation, stable morphology, and mechanical flexibility. The most representative and most widely used n‐CP acceptor was the naphthalene diimide based D‐A copolymer N2200 before 2017, and the power conversion efficiency (PCE) of the all‐PSCs based on N2200 reached over 8% in 2016. However, the low absorption coefficient of N2200 in the near‐infrared (NIR) region limits the further increase of its PCE. In 2017, we proposed a strategy of polymerizing small‐molecule acceptors (SMAs) to construct new‐generation polymer acceptors. The polymerized SMAs (PSMAs) possess low band gap and strong absorption in the NIR region, which attracted great attention and drove the PCE of the all‐PSCs to over 15% recently. In this Minireview we explain the design strategies of the molecular structure of PSMAs and describe recent research progress. Finally, current challenges and future prospects of the PSMAs are analyzed and discussed.
Conformation and Aromaticity Switching in a Curved Non‐Alternant sp2 Carbon Scaffold
Authors: Zhu Chongwei , Shoyama Kazutaka , Würthner Frank 
Published: August 2020

AbstractA curved sp2 carbon scaffold containing fused pentagon and heptagon units (1) was synthesized by Pd‐catalyzed [5+2] annulation from a 3,9‐diboraperylene precursor and shows two reversible oxidation processes at low redox potential, accompanied by a butterfly‐like motion. Stepwise oxidation produced radical cation 1.+ and dication 12+. In the crystal structure, 1 exhibits a chiral cisoid conformation and partial π‐overlap between the enantiomers. For the radical cation 1.+, a less curved cisoid conformation is observed with a π‐dimer‐type arrangement. 12+ adopts a more planar structure with transoid conformation and slip‐stacked π‐overlap with closest neighbors. We also observed an intermolecular mixed‐valence complex of 1⋅(1.+)3 that has a huge trigonal unit cell [(1)72(SbF6)54⋅(hexane)101] and hexagonal columnar stacks. In addition to the conformational change, the aromaticity of 1 changes from localized to delocalized, as demonstrated by AICD and NICS(1)zz calculations.
Enantio‐ and Regioselective NiH‐Catalyzed Reductive Hydroarylation of Vinylarenes with Aryl Iodides
Authors: He Yuli , Liu Chuang , Yu Lei , Zhu Shaolin 
Published: August 2020

AbstractA highly enantio‐ and regioselective hydroarylation process of vinylarenes with aryl halides has been developed using a NiH catalyst and a new chiral bis imidazoline ligand. A broad range of structurally diverse, enantioenriched 1,1‐diarylalkanes, a structure found in a number of biologically active molecules, have been obtained with excellent yields and enantioselectivities under extremely mild conditions.
Comprehensive Behavioral Phenotyping of a 16p11.2 Del Mouse Model for Neurodevelopmental Disorders
Authors: Lynch Joseph F. , Ferri Sarah L. , Angelakos Christopher , Schoch Hannah , Nickl‐Jockschat Thomas , Gonzalez Arnold , O'Brien William Timothy , Abel Ted 
Published: August 2020

The microdeletion of copy number variant 16p11.2 is one of the most common genetic mutations associated with neurodevelopmental disorders, such as Autism Spectrum Disorders (ASDs). Here, we describe our comprehensive behavioral phenotyping of the 16p11.2 deletion line developed by Alea Mills on a C57BL/6J and 129S1/SvImJ F1 background (Delm). Male and female Delm mice were tested in developmental milestones as preweanlings (PND2‐PND12), and were tested in open field activity, elevated zero maze, rotarod, novel object recognition, fear conditioning, social approach, and other measures during post‐weaning (PND21), adolescence (PND42), and adulthood (>PND70). Developmentally, Delm mice show distinct weight reduction that persists into adulthood. Delm males also have reduced grasp reflexes and limb strength during development, but no other reflexive deficits whereas Delm females show limb strength deficits and decreased sensitivity to heat. In a modified version of a rotarod task that measures balance and coordinated motor activity, Delm males, but not females, show improved performance at high speeds. Delm males and females also show age‐specific reductions in anxiety‐like behavior compared with WTs, but neither sex show deficits in a social preference task. When assessing learning and memory, Delm males and females show age‐specific impairments in a novel object or spatial object recognition, but no deficits in contextual fear memory. This work extends the understanding of the behavioral phenotypes seen with 16p11.2 deletion by emphasizing age and sex‐specific deficits; important variables to consider when studying mouse models for neurodevelopmental disorders.Lay SummaryAutism spectrum disorder is a common neurodevelopmental disorder that causes repetitive behavior and impairments in social interaction and communication. Here, we assess the effects of one of the most common genetic alterations in ASDs, a deletion of one copy of 29 genes, using a mouse model. These animals show differences in behavior between males and females and across ages compared with control animals, including changes in development, cognition, and motor coordination. Autism Res 2020, 13: 1670–1684. © 2020 International Society for Autism Research and Wiley Periodicals LLC
Neue numerische Simulation für alte Holzkonstruktionen
Authors: Konopka Daniel , Stöcklein Josef , Kaliske Michael 
Published: August 2020

AbstractHolz ist ein Werkstoff mit langer Tradition und breitem Anwendungsspektrum. Der Beitrag gibt einen Einblick in die Methodenentwicklung für die numerische Simulation historischer Kulturgüter aus Holz mit der Finite‐Elemente‐Methode. Die vorgestellten Ansätze sind konsistent auf alle Klassen von Holzstrukturen übertragbar. Die Materialeigenschaften von Holz sind grundsätzlich nichtlinear, skalen‐, richtungs‐, klima‐ und zeitabhängig. In Holzstrukturen tragen u. a. auch Klebfugen, Lackierungen und Furniere wesentlich zum klimaabhängigen Strukturverhalten bei. An Strukturbeispielen werden die Einflüsse des Materials, der mechanischen und insbesondere der klimatischen Beanspruchungen auf das zeitabhängige Strukturverhalten sowie die Ansätze der numerischen Simulation zur Bewertung des Tragverhaltens von Holzstrukturen mit aktuellen Modellen verdeutlicht. Der vorliegende Beitrag wurde am 18. Oktober 2019 im Rahmen des 23. Dresdner Baustatik Seminars präsentiert.
The effects of aerobic exercise on markers of maternal metabolism during pregnancy
Authors: McDonald Samantha M. , Strom Cody , Remchak Mary‐Margaret , Chaves Alec , Broskey Nicholas T. , Isler Christy , Haven Kelley , Newton Edward , DeVente James , Acosta‐Manzano Pedro , Aparicio Virginia A. , May Linda E. 
Published: August 2020

AbstractBackgroundOptimal maternal metabolism during pregnancy is essential for healthy fetal growth and development. Chronic exercise is shown to positively affect metabolism, predominantly demonstrated in nonpregnant populations.ObjectiveTo determine the effects of aerobic exercise on maternal metabolic biomarkers during pregnancy, with expected lower levels of glucose, insulin, and lipids among exercise‐trained pregnant women.MethodsSecondary data analyses were performed using data from two, longitudinal prenatal exercise intervention studies (ENHANCED by MOM and GESTAFIT). Exercisers completed 150 min of weekly moderate‐intensity exercise during pregnancy (24+ weeks) while nonexercisers attended stretching sessions. Pregnant women were 31–33 years of age, predominantly non‐Hispanic white, and “normal weight” body mass index. At 16 and 36 weeks of gestation, fasting blood samples were collected via fingerstick and venipuncture. Maternal glucose, insulin, insulin resistance (HOMA‐IR), total cholesterol (TC), low‐density lipoproteins (LDL), high‐density lipoproteins (HDL), and triglycerides (TG) were analyzed. ANCOVA analyses were performed to evaluate the effects of aerobic exercise on markers of maternal metabolism in late pregnancy, controlling for baseline levels.ResultsOur sample included 12 aerobic exercisers and 54 nonexercising control groups. Significant between‐groups differences at 16 weeks of gestation were found for TG (92.3 vs. 121.2 mg/dl, p = .04), TC (186.8 vs. 219.6 mg/dl, p = .002), and LDL (104.1 vs. 128.8 mg/dl, p = .002). Aerobic‐trained pregnant women exhibited lower insulin levels in late pregnancy (β = −2.6 μIU/ml, 95% CI:−4.2, −0.95, p = .002) and a reduced increase in insulin levels from 16 to 36 week of gestation (β = −2.3 μIU/ml, 95% CI: −4.4, −0.2, p = .034) compared with nonexercising pregnant women. No statistically significant effects were observed for maternal HOMA‐IR, TC, LDL, HDL, TC:HDL, and TG in late pregnancy.ConclusionsThe observations of this study demonstrate that prenatal exercise may positively affect maternal insulin, with aerobic‐trained pregnant women exhibiting lower insulin levels in late pregnancy. Additionally, we found no appreciable effects of prenatal exercise on maternal lipids in late pregnancy.
Development of a Thai tool for assessing behavioral and psychological symptoms of dementia: A confirmatory factor analysis
Authors: Phannarus Harisd , Muangpaisan Weerasak , Siritipakorn Pitiporn , Pianchob Sudarat , Supapueng Orawan 
Published: August 2020

AbstractIntroductionThe early recognition and management of the behavioral and psychological symptoms of dementia (BPSD) are important to inform treatment decisions. Current BPSD screening tools are time‐consuming and require advanced skills, limiting their application in routine clinical practice. An easier and quicker tool for use by nonphysician healthcare personnel is needed.MethodsA 14‐item, Thai‐language, BPSD scoring system for dementia (BPSD‐T) was developed, based on clinical surveys and modifications after a pilot study. The Neuropsychiatric Inventory (NPI), BPSD‐T, Thai Mental State Examination (TMSE), Clinical Dementia Rating Scale (CDR), and Barthel Index were performed. BPSD‐T and NPI scores were compared, and test validity and reliability were analyzed.ResultsA total of 168 people with dementia (mean age, 80.7 ± 6.7 years) and their primary caregivers were recruited. A total of 105 (62.5%) subjects were diagnosed with Alzheimer's disease (AD), and 31 (18.5%) with AD with small‐vessel disease. The Global CDR was 0.5–1 for 73.8% of subjects, and 2–3 for 26.2%. The BPSD‐T content validity index was 0.80–0.98, with high inter‐rater and test–retest reliability. Confirmatory factor analysis showed the goodness of fit of 5 clusters of BPSD‐T included a psychomotor syndrome (aggression, irritability, delusions, insomnia), an affective syndrome (apathy, repeating, anxiety, depression), a psychosis syndrome (misidentification, hallucinations), a behavior syndrome (hoarding, rummaging, wandering), and a euphoria syndrome (euphoria). Convergent validity showed a high correlation of the frequency score (r = 0.66) and caregiver distress score (r = 0.76) with the NPI. The BPSD‐T score was significantly higher with more severe dementia. The average completion time for the BPSD‐T (230.9 ± 65.5 s) was significantly less than that for NPI (506 ± 196.9 s; p < .001).ConclusionsBPSD‐T is a quick, reliable, and valid test to evaluate BPSD from the common dementia subtypes and severity, with a good correlation with the NPI. Its application in routine clinical practice will enable earlier recognition, targeted intervention, improved quality of care, and reduced caregiver burden.
Incorporation of Halogenated Amino Acids into Antibody Fragments at Multiple Specific Sites Enhances Antigen Binding
Authors: Hayashi Akiko , Haruna Ken‐ichi , Sato Haruna , Ito Kenichiro , Makino Chisato , Ito Takuhiro , Sakamoto Kensaku 
Published: August 2020

AbstractExpansion of the amino‐acid repertoire with synthetic derivatives introduces novel structures and functionalities into proteins. In this study, we improved the antigen binding of antibodies by incorporating halogenated tyrosines at multiple selective sites. Tyrosines in the Fab fragment of an anti‐EGF‐receptor antibody 059–152 were systematically replaced with 3‐bromo‐ and 3‐chlorotyrosines, and simultaneous replacements at four specific sites were found to cause a tenfold increase in the affinity toward the antigen. Structure modeling suggested that this effect was due to enhanced shape complementarity between the antigen and antibody molecules. On the other hand, we showed that chlorination in the constant domain, far from the binding interface, of Rituximab Fab also increased the affinity significantly (up to 17‐fold). Our results showed that antigen binding is tunable with the halogenation in and out of the binding motifs.
Biochemical and Structural Characterization of an Unusual and Naturally Split Class 3 Intein
Authors: Hoffmann Simon , Terhorst Tobias M. E. , Singh Rohit K. , Kümmel Daniel , Pietrokovski Shmuel , Mootz Henning D. 
Published: August 2020

AbstractSplit inteins are indispensable tools for protein engineering because their ligation and cleavage reactions enable unique modifications of the polypeptide backbone. Three different classes of inteins have been identified according to the nature of the covalent intermediates resulting from the acyl rearrangements in the multistep protein‐splicing pathway. Class 3 inteins employ a characteristic internal cysteine for a branched thioester intermediate. A bioinformatic database search of non‐redundant protein sequences revealed the absence of split variants in 1701 class 3 inteins. We have discovered the first reported split class 3 intein in a metagenomics data set and report its biochemical, mechanistic and structural analysis. The AceL NrdHF intein exhibits low sequence conservation with other inteins and marked deviations in residues at conserved key positions, including a variation of the typical class‐3 WCT triplet motif. Nevertheless, functional analysis confirmed the class 3 mechanism of the intein and revealed excellent splicing yields within a few minutes over a wide range of conditions and with barely detectable cleavage side reactions. A high‐resolution crystal structure of the AceL NrdHF precursor and a mutagenesis study explained the importance and roles of several residues at the key positions. Tolerated substitutions in the flanking extein residues and a high affinity between the split intein fragments further underline the intein's future potential as a ligation tool.