bluuebunny/crossref_metadata_2025_split huggingface dataset:
Autopolyploid lineage shows climatic niche expansion but not divergence inArabidopsis arenosa
Authors: Molina‐Henao Y. Franchesco , Hopkins Robin 
Published: January 2019

Premise of the StudySuccessful establishment of neopolyploids, and therefore polyploid speciation, is thought to be contingent on environmental niche shifts from their progenitors. We explore this niche shift hypothesis in the obligate outcrosserArabidopsis arenosacomplex, which includes diploid and recently formed autotetraploid populations.MethodsTo characterize the climatic niches for both cytotypes inArabidopsis arenosa,we first gathered climatic data from localities with known ploidy types. We then estimated the climatic niches for diploids and autotetraploids and calculated niche overlap. Using this niche overlap statistic, we tested for niche equivalency and similarity. We explored differences in niches by estimating and comparing niche optimum and breadth and then calculated indices of niche expansion and unfilling.Key ResultsClimatic niche overlap between diploids and autotetraploids is substantial. Although the two niche models are not significantly divergent, they are not identical as they differ in both optimum and breadth along two environmental gradients. Autotetraploids fill nearly the entire niche space of diploids and have expanded into novel environments.ConclusionsWe find climatic niche expansion but not divergence, together with a moderate change in the niche optimum, in the autotetraploid lineage ofArabidopsis arenosa. These results indicate that the climatic niche shift hypothesis alone cannot explain the coexistence of tetraploid and diploid cytotypes.
Positive School Climate as a Moderator of Violence Exposure for Colombian Adolescents
Authors: Gaias Larissa M. , Lindstrom Johnson Sarah , White Rebecca M. B. , Pettigrew Jonathan , Dumka Larry 
Published: January 2019

AbstractIn Colombia, many adolescents have experienced violence related to the decades‐long armed conflict in the country and have witnessed or been directly victimized by violence in their communities, often related to gang activity or drug trafficking. Exposure to violence, both political and community violence, has detrimental implications for adolescent development. This study used data from 1857 Colombian adolescents in an urban setting. We aim to understand the relations between exposure to violence and adolescent outcomes, both externalizing behaviors and developmental competence, and then to understand whether school climate (i.e., safety, connectedness, services) moderates these relations. Results demonstrate that armed conflict, community violence victimization, and witnessing community violence are positively associated with externalizing behaviors, but only armed conflict is negatively associated with developmental competence. School safety, connectedness, and services moderate the relation between community violence witnessing and externalizing behaviors. School services moderates the relation between community violence victimization and developmental competence. As students perceived more positive school climate, the effects of community violence exposure on outcomes were weakened. This study identifies potential levers for intervention regarding how schools can better support violence‐affected youth through enhancements to school safety, connectedness, and services.
Effects of some process parameters on the niflumic acid controlled release polymeric microspheres: Optimization using designs of experiments
Authors: Assas Nedjma , Elbahri Zineb , Baitiche Milad , Djerboua Ferhat 
Published: January 2019

AbstractMicroparticles charged by niflumic acid and based on cellulose derivatives as polymeric matrices, that is, ethylcellulose (EC) and mixtures of EC and hydroxypropylmethylcellulose (HPMC), were elaborated using microencapsulation by emulsion‐solvent evaporation technique. The niflumic acid is considered as a poorly water soluble drug, so the main objective of the paper is to use designs of experiment in order to prepare new solid formulations with a large range of size for the drug dissolution enhancement. The possible drug–polymer interaction was investigated by Fourier transform‐infrared spectroscopy, X‐ray diffraction, and differential scanning calorimetric analysis. Some of the process variables, namely, the stirring speed of emulsion, the emulsifier concentration, and the EC:HPMC ratio, were selected and varied. Their main and interactive effects on the microparticles' characteristics were obviously evaluated and discussed using Minitab software 16.1. The obtained microparticles' size (d10) ranged from 196 to 796 μm, and the drug entrapment reached 45% in some formulations. The drug dissolution results showed that the Higuchi's release constant varied from 0.011 to 0.067 min−1/2 and was enhanced especially when the HPMC concentration was increased.
Crack resistance improvement of rubber blend by a filler network of graphene
Authors: Zhou Xing , Wang Libing , Cao Xijuan , Yin Qiyan , Weng Gengsheng 
Published: January 2019

ABSTRACTCrack resistance of rubbers is of vital importance in many applications (e.g., tire and shock absorber). In this work, we demonstrate the crack resistance improvement and toughening of natural rubber–solution polymerized butadiene styrene rubber (NR–SSBR) blend by designing a filler network composed of graphene (GE). The well‐dispersed GE nanosheets contact with each other and bridge the adjacent GE nanosheets based on the π–π conjugation interaction, which preferentially break upon deformation and dissipate energy before the failure of the materials. The mechanisms of energy dissipation under small and large strains were further discussed. The approach of crack‐tip morphology monitoring was also applied to understand the crack resistance behavior of the rubber material. The GE network and its energy dissipation not only increase the tensile strength and toughness, but also enhance the crack resistance of the NR–SSBR by expanding the tear energy region of high cracking energy dissipation. Improvement on these properties will provide the rubber blend with better long‐term sustainability in practical applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47278.
Predicting embrittlement of polymer glasses using a hydrostatic stress criterion
Authors: Clarijs Coen C. W. J. , Leo Vito , Kanters Marc J. W. , van Breemen Lambert C. A. , Govaert Leon E. 
Published: January 2019

ABSTRACTIn this study, the aging‐induced embrittlement of three polymer glasses is investigated using a previously developed hybrid experimental–numerical method. The evolution of yield stress of unnotched tensile bars upon aging is coupled to the evolution of embrittlement of notched tensile bars using a numerical model combined with a critical hydrostatic stress criterion that determines the onset of failure. The time‐to‐embrittlement of notched tensile bars with a different notch geometry is predicted and in good agreement with the experimentally determined value. Next to that, the approach is extended to three polysulfone polymers, and it is shown that the value of the critical hydrostatic stress correlates well with the polymers entanglement density: : polymers with a denser entangled network display higher values, that is, a higher resistance against incipient cavitation. © 2019 The Authors. Journal of Applied Polymer Science published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47373.
Liposomes actively recognizing the glucose transporter GLUT1 and integrin αvβ3 for dual‐targeting of glioma
Authors: Fu Qiuyi , Zhao Yi , Yang Zhongzhen , Yue Qiming , Xiao Wenjiao , Chen Yang , Yang Yang , Guo Li , Wu Yong 
Published: January 2019

AbstractThe treatment of glioma is a great challenge because of the existence of the blood–brain barrier (BBB). In order to develop an efficient glioma‐targeting drug delivery system to greatly improve the brain permeability of anti‐cancer drugs and target glioma, a novel glioma‐targeted glucose‐RGD (Glu‐RGD) derivative was designed and synthesized as ligand for preparing liposomes to effectively deliver paclitaxel (PTX) to cross the BBB and target glioma. The liposomes were prepared and characterized for particle size, zeta potential, encapsulation efficiency, release profile, stability, hemolysis, and cell cytotoxicity. Also, the Glu‐RGD modified liposomes showed superior targeting ability in in vitro and in vivo evaluation as compared to naked PTX, non‐coated, singly modified liposomes and liposomes co‐modified by physical blending. The relative uptake efficiency and concentration efficiency were enhanced by 4.41‐ and 4.72‐fold compared to that of naked PTX, respectively. What is more, the Glu‐RGD modified liposomes also displayed the maximum accumulation of DiD‐loaded liposomes at tumor sites compared to the other groups in in vivo imaging. All the results in vitro and in vivo suggested that Glu‐RGD‐Lip would be a potential delivery system for PTX to treat integrin αvβ3‐overexpressing tumor‐bearing mice.
A Zwitterionic Liquid Electrolyte for Magnesium Batteries
Authors: Tröger‐Müller Steffen , Liedel Clemens 
Published: January 2019

AbstractRechargeable magnesium batteries are promising energy storage devices due to their high theoretical capacity. However, currently a crucial hindrance for their realization is the limited number of suitable electrolytes, all of which show severe disadvantages. We circumvent volatility, flammability, and instability issues of other systems by presenting an electrolyte based on magnesium borohydride and the zwitterionic liquid (ZIL) 1‐butyl‐3‐methylimidazol‐2‐ylidene borane. We investigate the structure and properties of the electrolyte and compare it to a similar conventional system. Pronounced intermolecular interactions in the new electrolyte are investigated by 1H and 11B NMR spectroscopy. We also characterize galvanostatic cycling and deposition of magnesium on different electrodes and analyze the deposited material. Because of high reversibility and stability of the ZIL based electrolyte system, it shows promising potential for future magnesium based batteries.
Analyzing conditions for recognizing pictures of family members in a patient with Alzheimer's disease
Authors: Brogård‐Antonsen Anette , Arntzen Erik 
Published: January 2019

AbstractIn the present study, an 89‐year‐old woman with the neurocognitive disorder Alzheimer's disease participated. The purpose was to study recognition of the participant's relatives' faces with the use of sorting tests and matching‐to‐sample (MTS) trainings and tests for emergent relations. The stimuli used were pictures of her relatives, their written names, and their family relationship. The study also focused on how responding to pictures of relatives changed over time. Therefore, the participant was presented with experimental conditions over three time periods. Time Period 1 included only sorting tests. In Time Period 2, which began 9 months after Time Period 1, the participant was presented with both sorting tests and conditional discrimination training and testing. In Time Period 3, which began 1 year after Time Period 2, both sorting tests and conditional discrimination training and testing were again presented. The results from Time Periods 2 and 3 showed that the percentage of stimuli sorted correctly was maintained over time. Additionally, the results from the MTS training and tests were maintained at the second follow‐up periods.
The use of behavioral skills training to improve staff performance of discrete trial training
Authors: Clayton Michael , Headley Ali 
Published: January 2019

Well‐trained staff are a prerequisite for successful implementation of treatment plans when working in human service contexts. The high rate of turnover makes the use of efficient and effective staff training all the more important. Previous research has used behavioral skills training to train teachers in correct implementation of discrete trial training of children with autism. They showed that a brief 10‐min procedure could effectively train staff and result in improved performance. The current study elaborated on previous work by using participants without prior exposure to the method, including treatment integrity data and testing for maintenance 1 month after training ended. The mean percentage of correct teaching responses for the three participants increased from 70%, 58%, and 66% during baseline to 97%, 96%, and 99%, respectively, following training. Results indicated that the training package was effective and the results were maintained 30 days later.
The Effect of sequential bilateral low‐frequency rTMS over dorsolateral prefrontal cortex on serum level of BDNF and GABA in patients with primary insomnia
Authors: Feng Jie , Zhang Qing , Zhang Chengliang , Wen Zhongmin , Zhou Xianju 
Published: January 2019

AbstractObjectiveThis study aimed to investigate the effect of sequential bilateral low‐frequency repetitive transcranial magnetic stimulation (rTMS) over dorsolateral prefrontal cortex (DLPFC) on patients with primary insomnia (PI).MethodsA total of 32 eligible right‐handed participants diagnosed by PI according to International classification of sleep disorders (ICD‐3) were recruited into this study. Participants received 10 daily sessions of sequential bilateral 1 Hz rTMS over DLPFC. Before and after the whole procedure of rTMS, patients were assessed by Pittsburgh Sleep Quality Index (PSQI) for the severity of sleep disturbance. Meanwhile, serum concentration of brain‐derived neurotrophic factor (BDNF) and gamma‐aminobutyric acid (GABA) in patients was measured by ELISA and UPLC, respectively. Moreover, the amplitude of MEPs reflecting the right cortical excitability was examined. Finally, Pearson correlation analysis was performed to evaluate the correlation among the change of these variables.ResultsAfter rTMS treatment, the PSQI score was markedly decreased as compared to pre‐rTMS; the concentrations of serum BDNF and GABA were significantly higher; the amplitude of MEPs was markedly reduced. Pearson correlation analysis revealed that the change of PSQI score was negatively associated with the alteration of serum BDNF level and serum GABA level, and positively associated with the change of MEPs amplitude; the change of MEPs amplitude was negatively associated with fold change in the serum BDNF level and the serum GABA level; the increase in serum GABA level was positively associated with the serum BDNF level.ConclusionsA sequential bilateral low‐frequency rTMS over DLPFC significantly improves primary insomnia probably by increasing the level of BDNF and GABA in the brain and reducing cortical excitability.
A Review on Quantitative Multiplexed Proteomics
Authors: Pappireddi Nishant , Martin Lance , Wühr Martin 
Published: January 2019

AbstractOver the last few decades, mass spectrometry‐based proteomics has become an increasingly powerful tool that is now able to routinely detect and quantify thousands of proteins. A major advance for global protein quantification was the introduction of isobaric tags, which, in a single experiment, enabled the global quantification of proteins across multiple samples. Herein, these methods are referred to as multiplexed proteomics. The principles, advantages, and drawbacks of various multiplexed proteomics techniques are discussed and compared with alternative approaches. We also discuss how the emerging combination of multiplexing with targeted proteomics might enable the reliable and high‐quality quantification of very low abundance proteins across multiple conditions. Lastly, we suggest that fusing multiplexed proteomics with data‐independent acquisition approaches might enable the comparison of hundreds of different samples without missing values, while maintaining the superb measurement precision and accuracy obtainable with isobaric tag quantification.
A Large Stokes Shift Fluorescent Protein Constructed from the Fusion of Red Fluorescent mCherry and Far‐Red Fluorescent BDFP1.6
Authors: Zhao Bao‐Qing , Ding Wen‐Long , Tan Zi‐Zhu , Tang Qi‐Ying , Zhao Kai‐Hong 
Published: January 2019

AbstractPhycobiliproteins are constituents of phycobilisomes that can harvest orange, red, and far‐red light for photosynthesis in cyanobacteria and red algae. Phycobiliproteins in the phycobilisome cores, such as allophycocyanins, absorb far‐red light to funnel energy to the reaction centers. Therefore, allophycocyanin subunits have been engineered as far‐red fluorescent proteins, such as BDFP1.6. However, most current fluorescent probes have small Stokes shifts, which limit their applications in multicolor bioimaging. mCherry is an excellent fluorescent protein that has maximal emittance in the red spectral range and a high fluorescence quantum yield, and thus, can be used as a donor for energy transfer to a far‐red acceptor, such as BDFP1.6, by FRET. In this study, mCherry was fused with BDFP1.6, which resulted in a highly bright far‐red fluorescent protein, BDFP2.0, with a large Stokes shift (≈79 nm). The excitation energy was absorbed maximally at 587 nm by mCherry and transferred to BDFP1.6 efficiently; thus emitting strong far‐red fluorescence maximally at 666 nm. The effective brightness of BDFP2.0 in mammalian cells was 4.2‐fold higher than that of iRFP670, which has been reported as the brightest far‐red fluorescent protein. The large Stokes shift of BDFP2.0 facilitates multicolor bioimaging. Therefore, BDFP2.0 not only biolabels mammalian cells, including human cells, but also biolabels various intracellular components in dual‐color imaging.
Crystal Structures of the C‐Terminally Truncated Endoglucanase Cel9Q from Clostridium thermocellum Complexed with Cellodextrins and Tris
Authors: Jeng Wen‐Yih , Liu Chia‐I , Lu Te‐Jung , Lin Hong‐Jie , Wang Nai‐Chen , Wang Andrew H.‐J. 
Published: January 2019

AbstractEndoglucanase CtCel9Q is one of the enzyme components of the cellulosome, which is an active cellulase system in the thermophile Clostridium thermocellum. The precursor form of CtCel9Q comprises a signal peptide, a glycoside hydrolase family 9 catalytic domain, a type 3c carbohydrate‐binding module (CBM), and a type I dockerin domain. Here, we report the crystal structures of C‐terminally truncated CtCel9Q (CtCel9QΔc) complexed with Tris, Tris+cellobiose, cellobiose+cellotriose, cellotriose, and cellotetraose at resolutions of 1.50, 1.70, 2.05, 2.05 and 1.75 Å, respectively. CtCel9QΔc forms a V‐shaped homodimer through residues Lys529–Glu542 on the type 3c CBM, which pairs two β‐strands (β4 and β5 of the CBM). In addition, a disulfide bond was formed between the two Cys535 residues of the protein monomers in the asymmetric unit. The structures allow the identification of four minus (−) subsites and two plus (+) subsites; this is important for further understanding the structural basis of cellulose binding and hydrolysis. In the oligosaccharide‐free and cellobiose‐bound CtCel9QΔc structures, a Tris molecule was found to be bound to three catalytic residues of CtCel9Q and occupied subsite −1 of the CtCel9Q active‐site cleft. Moreover, the enzyme activity assay in the presence of 100 mm Tris showed that the Tris almost completely suppressed CtCel9Q hydrolase activity.
A Systematic Study on Bond Activation Energies of NO, N2, and O2 on Hexamers of Eight Transition Metals
Authors: Ichino Tomoya , Takagi Makito , Maeda Satoshi 
Published: January 2019

AbstractCatalytic bond activation pathways of diatomic molecules on small metal clusters have been studied by density functional theory calculations. The focus of this study is dissociation of NO, N2, and O2 on hexamers of eight transition metals (Ni, Cu, Rh, Pd, Ag, Ir, Pt, and Au). For all the 24 cases, the lowest energy structures at the molecular‐adsorption state, bond dissociation transition state (TS), and dissociative‐adsorption state were identified by a systematic procedure. At TS of 20 cases, the transition metal hexamer moiety took a different shape from bare transition metal hexamers. The results support the importance of metastable cluster structures in catalytic activity, recently proposed in several catalytic systems. Furthermore, using the obtained dataset, a simple linear regression analysis was made to explore the applicability of the Brønsted‐Evans‐Polanyi principle to flexible metal cluster catalysts.
Bioelectrocatalytic Electrodes Modified with PQQ‐Glucose Dehydrogenase‐Calmodulin Chimera Switchable by Peptide Signals: Pathway to Generic Bioelectronic Systems Controlled by Biomolecular Inputs
Authors: Gamella Maria , Guo Zhong , Alexandrov Kirill , Katz Evgeny 
Published: January 2019

AbstractConstruction of artificial allosteric protein switches is one of the central goals of synthetic biology that holds promise to transform the way we detect and quantify substances in vitro and in vivo. An artificial chimeric fusion protein of pyrroloquinoline quinone‐dependent glucose dehydrogenase with calmodulin (PQQ‐GDH‐CaM) was covalently attached to graphene nanosheets produced electrochemically on a carbon fiber electrode. The chimeric PQQ‐GDH‐CaM represents an artificial allosteric switch activated by association of a calmodulin‐binding peptide with the Ca2+‐bound calmodulin domain. The activity of the immobilized enzyme was switched between active and inactive states by adding/removing the activating peptide. The peptide‐signal switchable features originated from the enzyme 3D‐structural variations induced by the conformational (folding/unfolding) changes in the connected calmodulin unit upon formation/dissociation of its complex with the specific peptide. The peptide‐activated immobilized PQQ‐GDH‐CaM enzyme displayed direct (non‐mediated) electron transfer to the conducting electrode support upon glucose oxidation. On the contrary, in the absence of the peptide, the inactive form of the enzyme demonstrated very low bioelectrocatalytic activity for glucose oxidation. Since the conformational changes of the PQQ‐GDH‐CaM depend on the presence of Ca2+ cations and the calmodulin‐binding peptide, both of them were used as input signals to control the enzyme activity mimicking a Boolean AND logic gate. The switchable behavior of the enzyme‐modified electrode was studied electrochemically and used to assemble a signal‐switchable biofuel cell. The use of the peptide as the signaling messenger enables the design of generalizable bioelectronic systems controlled by native and synthetic biochemical signaling systems.
Flavonoids enantiomer distribution in different parts of goldenrod (Solidago virgaurea L.), lucerne (Medicago sativa L.) and phacelia (Phacelia tanacetifolia Benth.)
Authors: Kruk Judyta , Baranowska Irena , Buszewski Bogusław , Bajkacz Sylwia , Kowalski Bartosz , Ligor Magdalena 
Published: January 2019

AbstractPlant material is a rich source of valuable compounds such as flavanones. Their different forms influence bioavailability and biological activity, causing problems with the selection of plant material for specific purposes. The purpose of this research was to determine selected flavanone (eriodictyol, naringenin, liquiritigenin, and hesperetin) enantiomer contents in free form and bonded to glycosides by an RP‐UHPLC‐ESI‐MS/MS method. Different parts (stems, leaves, and flowers) of goldenrod (Solidago virgaurea L.), lucerne (Medicago sativa L.), and phacelia (Phacelia tanacetifolia Benth.) were used. The highest content of eriodictyol was found in goldenrod flowers (13.1 μg/g), where it occurred mainly as the (S)‐enantiomer, and the greatest proportion of the total amount was bonded to glycosides. The richest source of naringenin was found to be lucerne leaves (4.7 μg/g), where it was mainly bonded to glycosides and with the (S)‐enantiomer as the dominant form. Liquiritigenin was determined only in lucerne, where the flowers contained the highest amount (1.2 μg/g), with the (R)‐enantiomer as dominant aglycone form and the (S)‐enantiomer as the dominant glycosylated form. The highest hesperetin content was determined in phacelia leaves (0.38 μg/g), where it was present in the form of a glycoside and only as the (S)‐enantiomer. A comparison of the different analyte forms occurring in different plant parts was performed for the first time.