bluuebunny/crossref_metadata_2025_split huggingface dataset:
[3+2]‐Fragmentierung von Pentaphosphidoliganden durch Cyanid
Authors: Hoidn Christian M. , Maier Thomas M. , Trabitsch Karolina , Weigand Jan J. , Wolf Robert 
Published: October 2019

AbstractDie Aktivierung von weißem Phosphor (P4) durch Übergangsmetallkomplexe wird seit Jahrzehnten erforscht, allerdings wurde die Funktionalisierung und Freisetzung der hierbei gebildeten Phosphorliganden vergleichsweise selten realisiert. In dieser Arbeit berichten wir über die Bildung von ungewöhnlichen Diphosphan‐1‐idanionen durch die Reaktion von einem P5‐Liganden mit Cyanidanionen. Neue Cobaltkomplexe mit Organopentaphosphidoliganden wurden in zwei Stufen durch die Umsetzung eines α‐Diimincobaltkomplexes mit weißem Phosphor und anschließend mit Diorganochlorphosphanen erhalten. Reaktionen der Diorganopentaphosphidokomplexe mit Tetraalkylammoniumcyanid bzw. Kaliumcyanid führen zu einem anionischen Cyclotriphosphidokomplex5und 1‐Cyano‐diphosphan‐1‐idanionen [R2PPCN]−(6‐R). Die Molekülstruktur eines verwandten Reaktionsproduktes7gibt einen Hinweis auf den möglichen Reaktionsmechanismus. Hierbei verursacht die Koordination des Cyanidanions an Cobalt eine Umlagerung des Pentaphosphidoliganden. Anschließend setzt der nukleophile Angriff eines zweiten Cyanidanions an einem Phosphoratom das [R2PPCN]−‐Anion (6‐R) frei.
Halide Anion Triggered Reactions of Michael Acceptors with Tropylium Ion
Authors: Hussein Mohanad A. , Tran Uyen P. N. , Huynh Vien T. , Ho Junming , Bhadbhade Mohan , Mayr Herbert , Nguyen Thanh V. 
Published: October 2019

AbstractTropylium bromide undergoes noncatalyzed, regioselective additions to a large variety of Michael acceptors. In this way, acrylic esters are converted into β‐bromo‐α‐cycloheptatrienylpropionic esters. The reactions are interpreted as nucleophilic attack of bromide ions at the electron‐deficient olefins and the approach of the tropylium ion to the incipient carbanion. Quantum chemical calculations were performed to elucidate the analogy to the amine‐ or phosphine‐catalyzed Rauhut–Currier reactions. Subsequent synthetic transformations of the bromo‐cycloheptatrienylated adducts are reported.
Exploring the Trans‐Cleavage Activity of CRISPR‐Cas12a (cpf1) for the Development of a Universal Electrochemical Biosensor
Authors: Dai Yifan , Somoza Rodrigo A , Wang Liu , Welter Jean F. , Li Yan , Caplan Arnold I , Liu Chung Chiun 
Published: October 2019

AbstractAn accurate, rapid, and cost‐effective biosensor for the quantification of disease biomarkers is vital for the development of early‐diagnostic point‐of‐care systems. The recent discovery of the trans‐cleavage property of CRISPR type V effectors makes CRISPR a potential high‐accuracy bio‐recognition tool. Herein, a CRISPR‐Cas12a (cpf1) based electrochemical biosensor (E‐CRISPR) is reported, which is more cost‐effective and portable than optical‐transduction‐based biosensors. Through optimizing the in vitro trans‐cleavage activity of Cas12a, E‐CRIPSR was used to detect viral nucleic acids, including human papillomavirus 16 (HPV‐16) and parvovirus B19 (PB‐19), with a picomolar sensitivity. An aptamer‐based E‐CRISPR cascade was further designed for the detection of transforming growth factor β1 (TGF‐β1) protein in clinical samples. As demonstrated, E‐CRISPR could enable the development of portable, accurate, and cost‐effective point‐of‐care diagnostic systems.
A Pyrazine‐Based Polymer for Fast‐Charge Batteries
Authors: Mao Minglei , Luo Chao , Pollard Travis P. , Hou Singyuk , Gao Tao , Fan Xiulin , Cui Chunyu , Yue Jinming , Tong Yuxin , Yang Gaojing , Deng Tao , Zhang Ming , Ma Jianmin , Suo Liumin , Borodin Oleg , Wang Chunsheng 
Published: October 2019

AbstractThe lack of high‐power and stable cathodes prohibits the development of rechargeable metal (Na, Mg, Al) batteries. Herein, poly(hexaazatrinaphthalene) (PHATN), an environmentally benign, abundant and sustainable polymer, is employed as a universal cathode material for these batteries. In Na‐ion batteries (NIBs), PHATN delivers a reversible capacity of 220 mAh g−1at 50 mA g−1, corresponding to the energy density of 440 Wh kg−1, and still retains 100 mAh g−1at 10 Ag−1after 50 000 cycles, which is among the best performances in NIBs. Such an exceptional performance is also observed in more challenging Mg and Al batteries. PHATN retains reversible capacities of 110 mAh g−1after 200 cycles in Mg batteries and 92 mAh g−1after 100 cycles in Al batteries. DFT calculations, X‐ray photoelectron spectroscopy, Raman, and FTIR show that the electron‐deficient pyrazine sites in PHATN are the redox centers to reversibly react with metal ions.
Anisotropic Thermal Expansion as the Source of Macroscopic and Molecular Scale Motion in Phosphorescent Amphidynamic Crystals
Authors: Jin Mingoo , Yamamoto Sho , Seki Tomohiro , Ito Hajime , Garcia‐Garibay Miguel A. 
Published: October 2019

AbstractHerein we report a crystalline molecular rotor with rotationally modulated triplet emission that displays macroscopic dynamics in the form of crystal moving and/or jumping, also known as salient effects. Molecular rotor 2 with a central 1,4‐diethynyl‐2,3‐difluorophenylene rotator linked to two gold(I) nodes, crystalizes as infinite 1D chains through intermolecular gold(I)–gold(I) interactions. The rotational motion changes the orientation of the central phenylene, changing the electronic communication between adjacent chromophores, and thus the emission intensities. Crystals of 2 showed the large and reversible thermal expansion/compression anisotropy, which accounts for 1) a nonlinear Arrhenius behavior in molecular‐level rotational dynamics, which correlates with 2) changes in emission, and determines 3) the macroscopic crystal motion. A molecular rotor analogue 3 has properties similar to those of 2, suggesting a generalized way to control mechanical properties at molecular and macroscopic scales.
Nickel‐Catalyzed Domino Heck‐Type Reactions Using Methyl Esters as Cross‐Coupling Electrophiles
Authors: Zheng Yan‐Long , Newman Stephen G. 
Published: October 2019

AbstractWhile esters are frequently used as traditional electrophiles in substitution chemistry, their application in cross‐coupling chemistry is still in its infancy. This work demonstrates that methyl esters can be used as coupling electrophiles in Ni‐catalyzed Heck‐type reactions through the challenging cleavage of the C(acyl)−O bond under relatively mild reaction conditions at either 80 or 100 °C. With the σ‐NiII intermediate generated from the insertion of acyl NiII species into the tethered C=C bond, carbonyl‐retentive products were formed by domino Heck/Suzuki–Miyaura coupling and Heck/reduction pathways when organoboron and mild hydride nucleophiles are used.
Proto‐Urea‐RNA (Wöhler RNA) Containing Unusually Stable Urea Nucleosides
Authors: Okamura Hidenori , Crisp Antony , Hübner Sarah , Becker Sidney , Rovó Petra , Carell Thomas 
Published: October 2019

AbstractThe RNA world hypothesis assumes that life on Earth began with nucleotides that formed information‐carrying RNA oligomers able to self‐replicate. Prebiotic reactions leading to the contemporary nucleosides are now known, but their execution often requires specific starting materials and lengthy reaction sequences. It was therefore proposed that the RNA world was likely proceeded by a proto‐RNA world constructed from molecules that were likely present on the early Earth in greater abundance. Herein, we show that the prebiotic starting molecules bis‐urea (biuret) and tris‐urea (triuret) are able to directly react with ribose. The urea‐ribosides are remarkably stable because they are held together by a network of intramolecular, bifurcated hydrogen bonds. This even allowed the synthesis of phosphoramidite building blocks and incorporation of the units into RNA. Investigations of the nucleotides’ base‐pairing potential showed that triuret:G RNA base pairs closely resemble U:G wobble base pairs. Based on the probable abundance of urea on the early Earth, we postulate that urea‐containing RNA bases are good candidates for a proto‐RNA world.
Biodegradable Poly(butylene adipate‐co‐terephthalate) composites reinforced with bio‐based nanochitin: Preparation, enhanced mechanical and thermal properties
Authors: Meng Dan , Xie Jiazhuo , Waterhouse Geoffrey I. N. , Zhang Kun , Zhao Qinghua , Wang Shuo , Qiu Shuo , Chen Kaijun , Li Jinxi , Ma Chizhen , Pan Yue , Xu Jing 
Published: October 2019

ABSTRACTThe accumulation of nonbiodegradable petrochemical‐based polymers in the environment motivates the development and use of low‐cost, eco‐friendly, and biodegradable polymers. A series of biodegradable poly(butylene adipate‐co‐terephthalate) composites reinforced by sustainably sourced nanochitin were successfully prepared using melt blending and compression molding methods. Structural, thermal, and mechanical characterizations of poly(butylene adipate‐co‐terephthalate) (PBAT)/nanochitin composites were performed. SEM revealed that the nanochitin was uniformly dispersed throughout the PBAT matrix at low contents (<2 wt %), while DSC analyses revealed a corresponding increase in the crystallinity (32.6% enhancement) of the PBAT matrix. The tensile strength and elongation at break of the PBAT/nanochitin composite containing 0.5 wt % nanochitin were higher by 82.5 and 64.2%, respectively, compared with pristine PBAT. The Chitin‐0.5 composite also showed improved thermal stability compared with PBAT (the char yield improved by 8%) due to the uniform dispersion of nanochitin in the PBAT matrix. The enhanced performance of the PBAT/nanochitin composites, prepared without an added compatibilizer, informs the development of improved biodegradable PBAT‐based polymers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48485.
Toughening of thermoset green zein resin: A comparison between natural rubber‐based additives and plasticizers
Authors: Souzandeh Hamid , Netravali Anil N. 
Published: October 2019

ABSTRACTZein‐based brittle thermoset green resin was toughened using sorbitol, natural rubber fibers (NRF), and epoxidized natural rubber fibers (ENRF). NRF and ENRF were electrospun directly into zein slurry. Chemical, thermal, and mechanical properties of zein resin containing NRF (Zein/NRF) and ENRF (Zein/ENRF) were compared with those of sorbitol‐plasticized zein. NRF was found to be immiscible in zein and Zein/NRF resins showed two distinct glass transition temperatures (T
g), whereas Zein/ENRF specimens showed significant increases in both T
g and degradation temperature (T
d) due to crosslinking between zein and epoxidized natural rubber. ENRF was more effective in enhancing fracture toughness of zein than NRF or sorbitol. Increased ENRF loading to 15 wt % showed significant increase in toughness with minimal decreases in strength and Young's modulus. Sorbitol and NRF were unable to improve the toughness of zein resin significantly. Environment‐friendly zein/ENRF resin with higher fracture toughness developed in this study would be suitable in many applications including green composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48512.
Improving ultraviolet light photocatalytic activity of polyaniline/silicon carbide composites by Fe‐doping
Authors: Koysuren Ozcan 
Published: October 2019

ABSTRACTIt was aimed to prepare polyaniline (Pani) composites, including silicon carbide (SiC) nanofibers doped with iron (Fe) ions. The Fe‐doping of SiC was performed to enhance the photocatalytic activity of the composites through the separation of photoexcited mobile charge carriers. For comparison purposes, Pani composites were also prepared with undoped SiC nanofibers. The composite samples were characterized by FTIR, XRD, SEM, EDX, and UV–Vis spectroscopies. Experiments on photocatalytic degradation of methylene blue under ultraviolet light irradiation revealed that Pani/SiC‐Fe composites exhibited higher photocatalytic activity when compared with Pani/SiC composites. Almost 22% dye removal was obtained within 300 min with the Pani composite, containing 15 wt.% SiC‐Fe. FTIR, XRD, SEM, EDX, and UV–Vis spectroscopies demonstrated that SiC nanofibers were successfully doped with iron ions and incorporated into the polyaniline matrix. The original aspect of this study was to research the photocatalytic activity of polyaniline composites containing Fe‐doped SiC nanofibers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48524.
Poly(vinyl alcohol)/carboxyl graphene mixed matrix membranes: High‐power ultrasonic treatment for enhanced pervaporation performance
Authors: Han Guang Lu , Chen Zhe , Cai Li Fang , Zhang Yong Hui , Tian Jun Feng , Ma Huan Huan , Fang Shao Ming 
Published: October 2019

ABSTRACTHigh‐power ultrasonic treatment was conducted during the mixing process to obtain poly(vinyl alcohol) (PVA)/carboxyl graphene (CG) mixed matrix membranes (MMMs). Results from X‐ray photoelectron spectrometer and thermogravimetric analysis confirmed the enhanced esterification reaction. The increased amorphous region and free volume were investigated by wide‐angle X‐ray diffraction and positron annihilation lifetime spectroscopy. Scanning electron microscope and atomic force microscope measurements suggested that ultrasonic could uniformly disperse CG in PVA polymer matrix. The mechanical properties and hydrophilicity of as‐prepared membrane were enhanced due to ultrasonic treatment. The permeation flux and separation factor of PVA/CG‐US membrane for 90 wt % ethanol aqueous solution were 0.79 kg m−2 h−1 and 860, respectively. For methanol (15 wt %)/methyl tert‐butyl ether mixture, its permeation flux and separation factor were also increased significantly compared with membranes without ultrasonic treatment. Due to the simplicity of the ultrasonic process and the versatility of the inorganic fillers, this method may contribute to the design of various MMMs and extend the application of these membranes in different uses. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48526.
Genome‐wide characterization and transcriptomic analyses of neuropeptides and their receptors in an endoparasitoid wasp, Pteromalus puparum
Authors: Xu Gang , Teng Zi‐Wen , Gu Gui‐Xiang , Qi Yi‐Xiang , Guo Lei , Xiao Shan , Wang Fei , Fang Qi , Wang Fang , Song Qi‐Sheng , Stanley David , Ye Gong‐Yin 
Published: October 2019

AbstractIn insects, neuropeptides constitute a group of signaling molecules that act in regulation of multiple physiological and behavioral processes by binding to their corresponding receptors. On the basis of the bioinformatic approaches, we screened the genomic and transcriptomic data of the parasitoid wasp, Pteromalus puparum, and annotated 36 neuropeptide precursor genes and 33 neuropeptide receptor genes. Compared to the number of precursor genes in Bombyx mori (Lepidoptera), Chilo suppressalis (Lepidoptera), Drosophila melanogaster (Diptera), Nilaparvata lugens (Hemiptera), Apis mellifera (Hymenoptera), and Tribolium castaneum (Coleoptera), P. puparum (Hymenoptera) has the lowest number of neuropeptide precursor genes. This lower number may relate to its parasitic life cycle. Transcriptomic data of embryos, larvae, pupae, adults, venom glands, salivary glands, ovaries, and the remaining carcass revealed stage‐, sex‐, and tissue‐specific expression patterns of the neuropeptides, and their receptors. These data provided basic information about the identity and expression profiles of neuropeptides and their receptors that are required to functionally address their biological significance in an endoparasitoid wasp.
Beyond the proportional frailty model: Bayesian estimation of individual heterogeneity on mortality parameters
Authors: Colchero Fernando , Kiyakoglu Burhan Y. 
Published: October 2019

AbstractToday, we know that demographic rates can be greatly influenced by differences among individuals in their capacity to survive and reproduce. These intrinsic differences, commonly known as individual heterogeneity, can rarely be measured and are thus treated as latent variables when modeling mortality. Finite mixture models and mixed effects models have been proposed as alternative approaches for inference on individual heterogeneity in mortality. However, in general models assume that individual heterogeneity influences mortality proportionally, which limits the possibility to test hypotheses on the effect of individual heterogeneity on other aspects of mortality such as ageing rates. Here, we propose a Bayesian model that builds upon the mixture models previously developed, but that facilitates making inferences on the effect of individual heterogeneity on mortality parameters other than the baseline mortality. As an illustration, we apply this framework to the Gompertz–Makeham mortality model, commonly used in human and wildlife studies, by assuming that the Gompertz rate parameter is affected by individual heterogeneity. We provide results of a simulation study where we show that the model appropriately retrieves the parameters used for simulation, even for low variances in the heterogeneous parameter. We then apply the model to a dataset on captive chimpanzees and on a cohort life table of 1751 Swedish men, and show how model selection against a null model (i.e., without heterogeneity) can be carried out.
Calcium imaging of primary canine sensory neurons: Small‐diameter neurons responsive to pruritogens and algogens
Authors: Ganchingco Joy Rachel C. , Fukuyama Tomoki , Yoder Jeffrey A. , Bäumer Wolfgang 
Published: October 2019

AbstractIntroductionRodent primary sensory neurons are commonly used for studying itch and pain neurophysiology, but translation from rodents to larger mammals and humans is not direct and requires further validation to make correlations.MethodsThis study developed a primary canine sensory neuron culture from dorsal root ganglia (DRG) excised from cadaver dogs. Additionally, the canine DRG cell cultures developed were used for single‐cell ratiometric calcium imaging, with the activation of neurons to the following pruritogenic and algogenic substances: histamine, chloroquine, canine protease‐activated receptor 2 (PAR2) activating peptide (SLIGKT), compound 48/80, 5‐hydroxytryptamine receptor agonist (5‐HT), bovine adrenal medulla peptide (BAM8‐22), substance P, allyl isothiocyanate (AITC), and capsaicin.ResultsThis study demonstrates a simple dissection and rapid processing of DRG collected from canine cadavers used to create viable primary sensory neuron cultures to measure responses to pruritogens and algogens.ConclusionRatiometric calcium imaging demonstrated that small‐diameter canine sensory neurons can be activated by multiple stimuli, and a single neuron can react to both a pruritogenic stimulation and an algogenic stimulation.
E‐learning engineers based on constructive and multidisciplinary approach
Authors: Pecanin Emir , Spalevic Petar , Mekic Edis , Jovic Srdjan , Milovanovic Ivan 
Published: October 2019

AbstractIn this study, we applied constructive approach to education supplemented with the innovation cycle approach. The main goal is to develop the innovative ideas from a clear start up to the implementation phase. Since multiple ideas tackle multidisciplinary problems, to properly present all needed concepts we used teachers from different fields of science. This was implemented through a pilot project and all results were assessed using a quasi experimental approach and constructive qualitative methodology to show the increase of interest with students in the areas of innovation, constructivism, and multidisciplinary on the cognitive, behavioral, and the affective level.
Plant system simulation for engineering training workshops
Authors: Ji Zuzhen , Pons D. J. , Pearse J. 
Published: October 2019

AbstractPlant system engineering (PSE) is a method of efficiently integrating machinery and human labor. Studies in PSE have been mainly concerned with production facilities rather than teaching facilities. Conventional simulation methods assume that the product moves through the workstations. In the more complex situation of the training workshop, both the student and the artifact being produced move through the workstations. Hence a training workshop requires a fundamentally different way of approaching the simulation. Also, the waiting time experience of the students needs consideration, from a teaching perspective. We adapted the system simulation methodology by including multiple work‐streams through the workshop, and by adding decision stages into the model. The method was applied to a training workshop. The results identified specific changes in the way the students were assigned to machines, and the number of different types of machines, that would improve the operation of the facility. The improvement measures were reduction in waiting time by students, and greater machine utilization. Multiple different class sizes were explored. The approach is broadly applicable to other situations where the people move through a facility along with a partially completed physical product. This work develops an approach to optimize the performance of a manufacturing system, for the unusual class situations where the product moving through the simulation is not merely a physical product as in conventional simulation approaches, but rather the combination of people (students) and their partially completed physical product.
Fecal occult blood test screening uptake among immigrants from Muslim majority countries: A retrospective cohort study in Ontario, Canada
Authors: Vahabi Mandana , Lofters Aisha , Wong Josephine Pui‐Hing , Ellison Lisa , Graves Erin , Damba Cynthia , Glazier Richard H. 
Published: October 2019

AbstractBackgroundColorectal cancer (CRC) is the second and third highest cause of cancer deaths among Canadian men and women, respectively. Population‐based screening through fecal occult blood testing (FOBT) has been proven to be effective in reducing CRC morbidity and mortality. Although participation in Ontario's organized CRC screening program has been increasing steadily since 2008, its uptake remains low among recent immigrant populations despite the known benefits of screening. To promote participation in CRC screening, it is imperative to understand both individual and system level barriers and enablers. Although a number of immigrant and nonimmigrant factors have been associated with low participation, there is a dearth of knowledge related to the religious affiliation in CRC screening uptake. Our study is among the first to examine this issue in Ontario, one of the most ethnically diverse Canadian provinces and preferred settlement destinations for immigrants.MethodsWe conducted a population‐based retrospective cohort study using linked health care administrative databases. Our cohort included Ontario residents, age 50‐74 who were eligible for FOBT from 1 April 2013 to 31 March 2015.ResultsWe found that immigrants from the Middle East and North Africa and Eastern Europe and Central Asia had the lowest rates of screening. Furthermore, being born in a Muslim‐majority country was associated with lower FOBT screening even after controlling for other confounders including world region and income (ie, overall adjusted relative risk (ARR) of screening 0.92 [95% CI 0.90‐0.93]). Moreover, being enrolled in a primary care model, having a female primary care provider and having an internationally trained physician were associated with increased screening among immigrants from Muslim‐majority countries.ConclusionsThese findings can inform future efforts to improve screening uptake like: enhancing access to primary care providers and enrollment in primary care models, targeted FOBT education for male providers and providers not in a primary care model, development of culturally sensitive and appropriate educational materials, and use of interactive approaches for communication of cancer screening information.