bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crosslinking Induced Reassembly of Multiblock Polymers: Addressing the Dilemma of Stability and Responsivity
Authors: Yang Rui , Zheng Yi , Shuai Xiaoyu , Fan Fan , He Xueling , Ding Mingming , Li Jianshu , Tan Hong , Fu Qiang 
Published: March 2020

AbstractPhysical or chemical crosslinking of polymeric micelles has emerged as a straightforward approach to overcome the intrinsic instability of assemblies. However, the crosslinking process may compromise the responsivity of nanosystems and result in inefficient release of payloads. To address this dilemma, a crosslinking induced reassembly (CIRA) strategy is reported here to simultaneously increase the kinetic and thermodynamic stability and redox‐responsivity of polymeric micelles. It is found that the click crosslinking of a model multiblock polyurethane at the micellar interface induces microphase separation between the soft and hard segments. The aggregation of hard domains gathers liable disulfide linkages around the interlayer of micelles, which could facilitate the attack of reducing agents and act as an intelligent on‐off switch for high stability and triggered release. As a result, the CIRA approach enables an enhanced tumor targeting, improved biodistribution and excellent therapeutic efficacy in vivo. This work provides a facile and versatile platform for controlled delivery applications.
Silicon mitigates ammonium toxicity in plants
Authors: Campos Cid Naudi Silva , Silva Júnior Gabriel Barbosa da , Prado Renato de Mello , David Carlos Henrique Oliveira de , Souza Junior Jonas Pereira de , Teodoro Paulo Eduardo 
Published: March 2020

AbstractThe search for high yield has identified ammonium toxicity as a problem in arable soils world wide. Ammonia toxicity can be suppressed by the use of silicon, but this fact still needs to be elucidated. Therefore, this review aimed to highlight the harmful effects of ammonium toxicity on model plants, and to determine the effects of Si on the mitigation of abiotic stress. Some plant species are considered as tolerant, and others as sensitive to high N concentrations. In sensitive plants, high ammonium concentrations may hinder the plant's development and even lead to the plant's death due to biochemical, physiological, and nutritional changes. Studies have demonstrated that silicon can mitigate or alleviate the deleterious effects caused by the toxic effect of NH4+. These findings were attributed to improvements in the physiological and nutritional parameters of plants. Given the importance of ionic balance between N forms for the plant's development, further studies must be performed to detect mechanisms promoted by Si to decrease or mitigate the harmful effects caused by excess ammonium in plants.
Effect of physical damage to early‐ and late‐maturing cotton cultivars
Authors: Plumblee Michael T. , Dodds Darrin M. , Krutz L. Jason , Raper Tyson B. , Jones Andrea S. , Catchot Angus L. , Irby J. Trenton , Jenkins Johnie N. 
Published: March 2020

AbstractDetermining the effects of timing and intensity of physical damage in cotton (Gossypium hirsutum L.) grown in the Mid‐South could improve management decisions and insurance adjustments after weather‐ or wildlife‐related crop damage has occurred. Research was conducted to quantify the effects of time of damage and intensity of damage on early‐ and late‐maturing cotton varieties in the Mid‐South. Cultivar selection affected plant height at first bloom, first bloom + 4 wk, and harvest (p ≤ .0008), and number of nodes at first bloom + 4 wk and harvest (p ≤ .0372). The interaction of intensity of damage by time of damage had an effect on plant height and number of nodes at pinhead square, first bloom, first bloom + 4 wk, and at harvest (p ≤ .0001), where reductions in plant height ranged from 20 to 57% and the number of nodes were reduced by 12–64% as damage increased when compared to the untreated check. Damage intensity by time of damage interaction affected lint turnout, lint yield, micronaire, fiber length, and fiber strength (p ≤ .0391). Reductions in lint yield (11–70%), lint turnout (2–6%), and micronaire (3–8%) were observed. Increases of 3 and 2% in fiber length and fiber strength, respectively, were also observed at eight node removal at pinhead square. Overall, as the intensity of damage increased, lint yield declined regardless of growth stage, therefore it should be expected to have yield loss where damage has occurred in cotton.
Midseason cultivation effects on anthracnose of annual bluegrass turf
Authors: Hempfling James W. , Murphy James A. , Clarke Bruce B. 
Published: March 2020

AbstractMechanical injury from cultivation practices is reported to enhance anthracnose disease, caused by the fungus Colletotrichum cereale Manns sensu lato Crouch, Clarke, and Hillman, of annual bluegrass (ABG) [Poa annua L. forma reptans (Hausskn.) T. Koyama]. Two field experiments were initiated with the objectives of determining the effects of midseason cultivation practices (Experiment 1) and scarifying depth (Experiment 2) on anthracnose severity of ABG maintained at a 3.2‐mm mowing height on a Nixon sandy loam in North Brunswick, NJ. Experiment 1 treatments consisted of grooming, verticutting, scarifying, and solid‐tining every 21 d as well as weekly grooming and no cultivation over 2 years. Experiment 2 evaluated single treatments of shallow and deep scarifying and a nontreated control in three runs. Verticutting increased the area under the disease progress curve (AUDPC) compared with no cultivation during the first year, whereas verticutting and scarifying increased AUDPC relative to no cultivation during the second year. No other cultivation treatments differed from the control during either year in Experiment 1. In Experiment 2, scarifying did not increase AUDPC during any run at either depth. Results from these experiments indicate that cultivation practices that affect at least 15% of the turf surface area and injure crowns may increase anthracnose severity, whereas practices that affect a smaller turf area or only leaf tissue will not increase disease severity.
Hired helpers at the nest: The association between life‐cycle servants and net fertility in North Orkney, 1851–1911
Authors: Jennings Julia A. 
Published: March 2020

AbstractObjectivesThe presence of kin is often, but not always, associated with higher fertility in historical populations. However, the effect of other household members on fertility is less frequently studied. While not genetically related, life‐cycle servants lived and worked alongside household members and may have provided assistance to reproducing families. Female servants in particular may have helped mothers with small children through direct help with childcare activities or by replacing the economic effort of mothers whose work was not compatible with childcare. This study examines the presence of servants in the households of married women of reproductive age to assess whether households with young children are more likely to also have servants.Materials and methodsThis study uses individual‐level census data from North Orkney, Scotland (1851–1911) to investigate the relationship between the presence of servants in households and a measure of recent net marital fertility, the number of women's own‐children under age 5, using logistic regression models.ResultsHouseholds with young children were more likely to have a female, but not male, servant in the household after controlling for the effects of other possible helpers, including older children, mothers, and mothers‐in‐law.DiscussionThese findings are consistent with prior research that indicates the importance of female labor to smallholder agricultural households and suggests that female servants may have provided support to reproducing families. Life‐cycle servants should be considered one component of biocultural reproduction in historical Northwest Europe. The use of hired help is not restricted to contemporary or elite groups.
Phosphorescence Energy Transfer: Ambient Afterglow Fluorescence from Water‐Processable and Purely Organic Dyes via Delayed Sensitization
Authors: Kuila Suman , George Subi J. 
Published: March 2020

AbstractAmbient afterglow luminescence from metal‐free organic chromophores would provide a promising alternative to the well‐explored inorganic phosphors. However, the realization of air‐stable and solution‐processable organic afterglow systems with long‐lived triplet or singlet states remains a formidable challenge. In the present study, a delayed sensitization of the singlet state of organic dyes via phosphorescence energy transfer from organic phosphors is proposed as an alternative strategy to realize “afterglow fluorescence”. This concept is demonstrated with a long‐lived phosphor as the energy donor and commercially available fluorescent dyes as the energy acceptor. Triplet‐to‐singlet Förster‐resonance energy‐transfer (TS‐FRET) between donor and acceptor chromophores, which are co‐organized in an amorphous polymer matrix, results in tuneable yellow and red afterglow from the fluorescent acceptors. Moreover, these afterglow fluorescent hybrids are highly solution‐processable and show excellent air‐stability with good quantum yields.
Delocalized aromatic molecules with matched electron‐donating and electron‐withdrawing groups enhancing insulating performance of polyethylene blends
Authors: Wei Zuojun , Liu Haiyan , Yu Linwei , Xiao Shuwen , Hou Yaxin , Chen Xiangrong 
Published: March 2020

AbstractSeven delocalized aromatic molecules with electron‐donating and electron‐withdrawing groups are applied as voltage stabilizers to improve the insulation properties of polyethylene blends. Voltage stabilizers 1 wt% are added into the blends (90 wt% low‐density polyethylene and 10 wt% high density polyethylene) by diffusion loading method. Electrical measurements including electrical treeing, space charge distribution, and direct current conductivity are conducted to disclose their effects. The results show that the co‐existence of matched electron‐donating and electron‐withdrawing groups in the molecules is favorable for the insulation properties. A 50% increase of tree initiation voltage is achieved with the addition of 3‐aminobenzoic acid, which is also able to inhibit the space charge and decrease the conductivity at lower temperature. Besides, the grafting sample of the optimal molecule is successfully prepared and displayed enhanced electrical properties. Finally, the common internal mechanism of the delocalized molecules on different electrical properties is revealed.
Novel robust observer‐controller synthesis method for Takagi‐Sugeno systems
Authors: Xie Wen‐Bo , Zheng Hua , Li Ming‐Yang , Shen Mou‐Quan 
Published: March 2020

AbstractFor the output feedback control problem of a T‐S fuzzy system, an
observer‐controller synthesis method is proposed. First, with parallel distributed compensation fuzzy observer and controller, an augmented error system is obtained. Based on Lyapunov function approaches, system stability and robust conditions are achieved. Then, by dividing the non‐convex conditions into observer‐dominant and controller dominant parts, the conditions are converted into convex form to facilitate the numerical solving process. Also, input saturation and system measurement disturbance are considered in the synthesis procedure. Finally, a numerical and a vessel control example are adopted to make comparisons with existing methods, with the results clearly showing the conservatism reduction effects and good control performance of the proposed method.
Developmental Transcriptional Enhancers: A Subtle Interplay between Accessibility and Activity
Authors: Bozek Marta , Gompel Nicolas 
Published: March 2020

AbstractMeasurements of open chromatin in specific cell types are widely used to infer the spatiotemporal activity of transcriptional enhancers. How reliable are these predictions? In this review, it is argued that the relationship between the accessibility and activity of an enhancer is insufficiently described by simply considering open versus closed chromatin, or active versus inactive enhancers. Instead, recent studies focusing on the quantitative nature of accessibility signal reveal subtle differences between active enhancers and their different inactive counterparts: the closed silenced state and the accessible primed and repressed states. While the open structure as such is not a specific indicator of enhancer activity, active enhancers display a higher degree of accessibility than the primed and repressed states. Molecular mechanisms that may account for these quantitative differences are discussed. A model that relates molecular events at an enhancer to changes in its activity and accessibility in a developing tissue is also proposed.
Nanobiohybrid Material‐Based Bioelectronic Devices
Authors: Yoon Jinho , Shin Minkyu , Lim Joungpyo , Kim Dong Yeon , Lee Taek , Choi Jeong‐Woo 
Published: March 2020

AbstractBiomolecules, especially proteins and nucleic acids, have been widely studied to develop biochips for various applications in scientific fields ranging from bioelectronics to stem cell research. However, restrictions exist due to the inherent characteristics of biomolecules, such as instability and the constraint of granting the functionality to the biochip. Introduction of functional nanomaterials, recently being researched and developed, to biomolecules have been widely researched to develop the nanobiohybrid materials because such materials have the potential to enhance and extend the function of biomolecules on a biochip. The potential for applying nanobiohybrid materials is especially high in the field of bioelectronics. Research in bioelectronics is aimed at realizing electronic functions using the inherent properties of biomolecules. To achieve this, various biomolecules possessing unique properties have been combined with novel nanomaterials to develop bioelectronic devices such as highly sensitive electrochemical‐based bioelectronic sensing platforms, logic gates, and biocomputing systems. In this review, recently reported bioelectronic devices based on nanobiohybrid materials are discussed. The authors believe that this review will suggest innovative and creative directions to develop the next generation of multifunctional bioelectronic devices.
Effect of admixtures and supplementary cementitious material on mechanical properties and durability of concrete
Authors: Asadollahfardi Gholamreza , Yahyaei Behnaz , Salehi Amir M. , Ovesi Arash 
Published: March 2020

AbstractWe studied the effects of superplasticizer (SP) (PCE1 and PCE2), air‐entraining admixtures (AEA), and supplementary cementitious material (silica fume and fly ash) on the mechanical and durability properties of concrete samples. Eight concrete mix designs were prepared. The first six concrete mix design contained similar aggregates, PCE2 SP, AEA, 350 kg/m3cement, and water to cement ratio equal to 0.38, and one of the mentioned mix design was selected as control samples with water to cement ratio equal to 0.57, without PCE2 SP and AEA. We used a different quantity of PCE2 SP and AEA and replaced the fly ash or silica fume as part of cement in two of the mentioned mix designs. The last two concrete mix designs studied the effect of PCE1 SP and AEA on freezing and thawing of concrete mix design. Adding PCE2 SP in concrete mix design increased compressive strength at age 11, 42, and 90 days sharply and reduced the depth of water penetration at the age of 28 and 90 days compared to the control sample. Using simultaneous PCE2 and AEA in concrete mix design did not improve compressive strength significantly and increased slightly depth of water penetration compared to only using PCE2. However, increasing the quantity of AEA to 5% improved both compressive strength and reduced depth of water penetration. In the second group of concrete mix design, adding both PCE1 and AEA increased the number of resistible freezing and thawing cycles of concrete. Side chain length and molecular weight of PCE1 and PCE2 SPs had no important effect on the compressive strength and performance properties of concrete.
Mechanism and Origin of MAD‐Induced Ni/N‐Heterocyclic Carbene‐Catalyzed Regio‐ and Enantioselective C−H Cyclization of Pyridines with Alkenes
Authors: Zhao Xia , Ma Xuexiang , Zhu Rongxiu , Zhang Dongju 
Published: March 2020

AbstractThis work presents a DFT‐based computational study on the regio‐ and enantioselective C−H functionalization of pyridines with alkenes at the relatively unreactive C4‐position, which was successfully achieved by Shi et al. [J. Am. Chem. Soc. 2019, 141, 5628–5634] using Ni0/N‐heterocyclic carbene (NHC) catalysis under the assistance of an aluminum‐based Lewis acid additive (2,6‐tBu2‐4‐Me‐C6H2O)2AlMe (MAD). The calculations indicate that the selective functionalization involves a three‐step mechanism in which a unique H‐migration assisted oxidation metalation (HMAOM) step is identified as the rate‐ and enantioselectivity‐determining step. The newly proposed mechanism can well rationalize the experimental observation that the preferred product is the endo‐type (vs. exo‐type), R‐configuration (vs. S‐configuration) product at the C4 (vs. C2) position, and also unveil the reasons that the NHC ligand and the MAD additive can facilitate the reaction.
Optoelectronic Properties of Carbon‐Bound Boron Difluoride Hydrazone Dimers
Authors: Cappello Daniela , Maar Ryan R. , Staroverov Viktor N. , Gilroy Joe B. 
Published: March 2020

AbstractThe creation of dimeric boron difluoride complexes of chelating N‐donor ligands is a proven strategy for the enhancement of the optoelectronic properties of fluorescent dyes. We report dimers based on the boron difluoride hydrazone (BODIHY) framework, which offer unique and sometimes unexpected substituent‐dependent absorption, emission, and electrochemical properties. BODIHY dimers have low‐energy absorption bands (λmax=421 to 479 nm, ϵ=17 200 to 39 900 m−1 cm−1) that are red‐shifted relative to monomeric analogues. THF solutions of these dimers exhibit aggregation‐induced emission upon addition of water, with emission enhancement factors ranging from 5 to 18. Thin films of BODIHY dimers are weakly emissive as a result of the inner‐filter effect, attributed to intermolecular π‐type interactions. BODIHY dimers are redox‐active and display two one‐electron oxidation and two one‐electron reduction waves that strongly depend on the N‐aryl substituents. These properties are rationalized using density‐functional theory calculations and X‐ray crystallography experiments.
Robust multivariate change point analysis based on data depth
Authors: Chenouri Shojaeddin , Mozaffari Ahmad , Rice Gregory 
Published: March 2020

AbstractModern methods for detecting changes in the scale or covariance of multivariate distributions rely primarily on testing for the constancy of the covariance matrix. These depend on higher‐order moment conditions, and also do not work well when the dimension of the data is large or even moderate relative to the sample size. In this paper, we propose a nonparametric change point test for multivariate data using rankings obtained from data depth measures. As the data depth of an observation measures its centrality relative to the sample, changes in data depth may signify a change of scale of the underlying distribution, and the proposed test is particularly responsive to detecting such changes. We provide a full asymptotic theory for the proposed test statistic under the null hypothesis that the observations are stable, and natural conditions under which the test is consistent. The finite sample properties are investigated by means of a Monte Carlo simulation, and these along with the theoretical results confirm that the test is robust to heavy tails, skewness and high dimensionality. The proposed methods are demonstrated with an application to structural break detection in the rate of change of pollutants linked to acid rain measured in Turkey lake, a lake in central Ontario, Canada. Our test suggests a change in the rate of acid rain in the late 1980s/early 1990s, which coincides with clean air legislation in Canada and the US.The Canadian Journal of Statistics48: 417–446; 2020 © 2020 Statistical Society of Canada
Learners’ conceptions about the chemical equilibrium – A systematic Review
Authors: Heeg Julian , Bittorf Robert M. , Schanze Sascha 
Published: March 2020

AbstractDas chemische Gleichgewicht ist ein wichtiger und zugleich schwieriger Themenbereich für Lernende wie Lehrende. Eine kategoriengestützte Übersicht von Lernendenvorstellungen kann einerseits als Planungshilfe verwendet werden, um an den Vorstellungen anzuknüpfen und sie gezielt als Lernmittel einzusetzen. Andererseits kann er Forschenden dazu dienen, Forschungsbedarfe zu identifizieren. Ergänzend ist es möglich die Ergebnisse eines solchen systematischen Überblicks als Ausgangspunkt für die fachdidaktische Lehre und die damit verbundenen Professionalisierungsprozesse von angehenden Lehrkräften zu nutzen. Der vorliegende Beitrag hat daher das Ziel, einen systematischen Überblick über dokumentierte Lernendenvorstellungen zum Themenbereich des chemischen Gleichgewichts zu geben. Hierfür wurden systematisch aus 284 Studien 18 Studien ausgewählt und untersucht, die explizit Lernendenvorstellungen zum chemischen Gleichgewicht formulieren. Die erfassten 239 Vorstellungen wurden ins Deutsche übersetzt und anschließend den folgenden fünf fachbezogenen Kategorien zugeordnet: (1) Zeitraum der Einstellung des dynamischen Gleichgewichts, (2) Charakteristika des chemischen Gleichgewichts, (3) Änderung der Reaktionsbedingungen, (4) Beeinflussung des chemischen Gleichgewichts durch Zugabe eines Katalysators und/oder inerten Gases und (5) Heterogene Gleichgewichtssysteme. Abschließend werden Implikationen für die fachdidaktische Forschung und Lehre skizziert.
Hippocampus‐avoidance whole‐brain radiation therapy with a simultaneous integrated boost for multiple brain metastases
Authors: Popp Ilinca , Rau Stephan , Hintz Mandy , Schneider Julius , Bilger Angelika , Fennell Jamina Tara , Heiland Dieter Henrik , Rothe Thomas , Egger Karl , Nieder Carsten , Urbach Horst , Grosu Anca Ligia 
Published: March 2020

BackgroundThe current study was aimed at investigating the feasibility of hippocampus‐avoidance whole‐brain radiation therapy with a simultaneous integrated boost (HA‐WBRT+SIB) for metastases and at assessing tumor control in comparison with conventional whole‐brain radiation therapy (WBRT) in patients with multiple brain metastases.MethodsBetween August 2012 and December 2016, 66 patients were treated within a monocentric feasibility trial with HA‐WBRT+SIB: hippocampus‐avoidance WBRT (30 Gy in 12 fractions, dose to 98% of the hippocampal volume ≤ 9 Gy) and a simultaneous integrated boost (51 or 42 Gy in 12 fractions) for metastases/resection cavities. Intracranial tumor control, hippocampal failure, and survival were subsequently compared with a retrospective cohort treated with WBRT via propensity score matching analysis.ResultsAfter 1:1 propensity score matching, there were 62 HA‐WBRT+SIB patients and 62 WBRT patients. Local tumor control (LTC) of existing metastases was significantly higher after HA‐WBRT+SIB (98% vs 82% at 1 year; P = .007), whereas distant intracranial tumor control was significantly higher after WBRT (82% vs 69% at 1 year; P = .016); this corresponded to higher biologically effective doses. Intracranial progression‐free survival (PFS; 13.5 vs 6.4 months; P = .03) and overall survival (9.9 vs 6.2 months; P = .001) were significantly better in the HA‐WBRT+SIB cohort. Four patients (6.5%) developed hippocampal metastases after hippocampus avoidance. The neurologic death rate after HA‐WBRT+SIB was 27.4%.ConclusionsHA‐WBRT+SIB can be an efficient therapeutic option for patients with multiple brain metastases and is associated with improved LTC of existing metastases, higher intracranial PFS, a reduction of the neurologic death rate, and an acceptable risk of radiation necrosis. The therapy has the potential to prevent neurocognitive adverse effects, which will be further evaluated in the multicenter, phase 2 HIPPORAD trial.