bluuebunny/crossref_metadata_2025_split huggingface dataset:
Moisture Sensitive Smart Yarns and Textiles from Self‐Balanced Silk Fiber Muscles
Authors: Jia Tianjiao , Wang Yang , Dou Yuanyuan , Li Yaowang , Jung de Andrade Monica , Wang Run , Fang Shaoli , Li Jingjing , Yu Zhou , Qiao Rui , Liu Zhuangjian , Cheng Yuan , Su Yewang , Minary‐Jolandan Majid , Baughman Ray H. , Qian Dong , Liu Zunfeng 
Published: March 2019

AbstractSmart textiles that sense, interact, and adapt to environmental stimuli have provided exciting new opportunities for a variety of applications. However, current advances have largely remained at the research stage due to the high cost, complexity of manufacturing, and uncomfortableness of environment‐sensitive materials. In contrast, natural textile materials are more attractive for smart textiles due to their merits in terms of low cost and comfortability. Here, water fog and humidity‐driven torsional and tensile actuation of thermally set twisted, coiled, plied silk fibers, and weave textiles from these silk fibers are reported. When exposed to water fog, the torsional silk fiber provides a fully reversible torsional stroke of 547° mm−1. Coiled‐and‐thermoset silk yarns provide a 70% contraction when the relative humidity is changed from 20% to 80%. Such an excellent actuation behavior originates from water absorption‐induced loss of hydrogen bonds within the silk proteins and the associated structural transformation, which are corroborated by atomistic and macroscopic characterization of silk and molecular dynamics simulations. With its large abundance, cost‐effectiveness, and comfortability for wearing, the silk muscles will open up additional possibilities in industrial applications, such as smart textiles and soft robotics.
High‐Security Multifunctional Nano‐Bismuth‐Sphere‐Cluster Prepared from Oral Gastric Drug for CT/PA Dual‐Mode Imaging and Chemo‐Photothermal Combined Therapy In Vivo
Authors: Xuan Yang , Yang Xiao‐Quan , Song Zi‐Yu , Zhang Ruo‐Yun , Zhao Dong‐Hui , Hou Xiao‐Lin , Song Xian‐Lin , Liu Bo , Zhao Yuan‐Di , Chen Wei 
Published: March 2019

AbstractMultifunctional nanoprobes that can be applied for real‐time monitoring or precision treatment of tumors have received wide interest among researchers. However, most of these nanoprobes are obtained through chemical synthesis, and thereby may contain toxic residues or harmful reagents. In this article, a nano‐bismuth‐sphere‐cluster (Bi) is synthesized via a one‐step method (after an irradiation with ultra‐violet) and is then applied in dual‐mode computed tomography/photoacoustic imaging. Bismuth potassium citrate granules, which is a common gastric drug that is highly safe and has a low price (<1 China Yuan/g), is used as the only raw material. The results show that the Bi cluster has good stability with sizes of about 25–55 nm, and a photothermal conversion efficiency as high as 39.67%. After being adsorbed onto doxorubicin, the Bi cluster can be used directly in animal experiments. Due to the effect of enhanced permeability and retention, the probe can easily enter tumor cells. Drug release can be controlled by a near‐infrared laser and the acidic environment of tumor cells, which indicates that the combined chemo‐photothermal therapy is achieved. This work presents a new dual‐mode bio‐imaging and combined chemo‐photothermal therapeutic nanoprobe that can be applied in theragnostics for tumors.
Expanding the Horizon of Mechanochromic Detection by Luminescent Shear Stress Sensor Supraparticles
Authors: Wintzheimer Susanne , Reichstein Jakob , Wenderoth Sarah , Hasselmann Sebastian , Oppmann Maximilian , Seuffert Marcel T. , Müller‐Buschbaum Klaus , Mandel Karl 
Published: March 2019

AbstractNovel sensor particles have been developed that expand the variety of today's mechanochromic systems. The developed supraparticles consist of several different components to enable the sensor function. First, a luminescence‐quenching core material is coated with silica nanoparticles. Second, this structure is surrounded by raspberry‐like nanostructured silica particles, which host luminophore moieties. Upon shear stress, components spatially separated in the original supraparticles, namely quencher and luminophore components, come into contact. This causes an irreversible quenching of the luminescence (sensor turn‐off). Different options to select core, quencher, and luminophore components allow to drive the sensors to different sensing options regarding response time, sensitivity, and operation time. The sensors can be sensitive and rapid in response or generated to monitor the influence of shear stress over longer periods of time. Thus, a rapid, visible, “on‐the‐fly” sensing of shear stress is possible as well as monitoring the impact of prolonged shear stress. The particles are assembled by spray‐drying. This affords flexibility when choosing the type of quencher and luminophore moiety. As such, the sensitivity of this robust, particle‐based shear stress sensor system can be deliberately configured. Furthermore, the supraparticle sensor can be integrated in surfaces to create interactive, communicating materials.
Multifunctional Polypyrrole‐Coated Mesoporous TiO2 Nanocomposites for Photothermal, Sonodynamic, and Chemotherapeutic Treatments and Dual‐Modal Ultrasound/Photoacoustic Imaging of Tumors
Authors: He Yue , Wan Jingyuan , Yang Yang , Yuan Pei , Yang Cheng , Wang Zhigang , Zhang Liangke 
Published: March 2019

AbstractTiO2 nanoparticles have emerged as satisfactory sonosensitizers in sonodynamic therapy over the years, but shortcomings such as poor drug loading capability and inadequate techniques to construct suitable TiO2 nanoparticles, limit their broader applications. Hence, in this paper, versatile nanocomposites that combine mesoporous TiO2 nanoparticles (mTiO2s) with the promising photothermal material, polypyrrole (PPY) to exert synergistic therapeutic effects on tumors are fabricated. The PPY‐coated mesoporous TiO2 nanocomposites (mTiO2@PPYs) act as drug delivery vehicles and ultrasonically activated sonosensitizers as well as photothermal agents. Besides, mTiO2@PPY may have potential as an ultrasound/photoacoustic (US/PA) imaging contrast agent. The mTiO2@PPY shows a favorable drug loading and good photothermal conversion ability. Moreover, intracellular reactive oxygen species generation is verified. The in vitro cell experiments on HepG2 and 4T1 cells demonstrate that honokiol (HNK)‐loaded mTiO2@PPY has satisfactory cytotoxicity under laser and US irradiation, and the results are further validated by animal experiments. The ability of mTiO2@PPY as a contrast agent for US and PA imaging is investigated both in vitro and in vivo. The results indicate that mTiO2@PPY‐HNK has multitherapeutic effects and bimodal imaging property, which shows great prospect as a novel nanosystem in antitumor applications.
Buoyancy‐Driven Gradients for Biomaterial Fabrication and Tissue Engineering
Authors: Li Chunching , Ouyang Liliang , Pence Isaac J. , Moore Axel C. , Lin Yiyang , Winter Charles W. , Armstrong James P. K. , Stevens Molly M. 
Published: March 2019

AbstractThe controlled fabrication of gradient materials is becoming increasingly important as the next generation of tissue engineering seeks to produce inhomogeneous constructs with physiological complexity. Current strategies for fabricating gradient materials can require highly specialized materials or equipment and cannot be generally applied to the wide range of systems used for tissue engineering. Here, the fundamental physical principle of buoyancy is exploited as a generalized approach for generating materials bearing well‐defined compositional, mechanical, or biochemical gradients. Gradient formation is demonstrated across a range of different materials (e.g., polymers and hydrogels) and cargos (e.g., liposomes, nanoparticles, extracellular vesicles, macromolecules, and small molecules). As well as providing versatility, this buoyancy‐driven gradient approach also offers speed (<1 min) and simplicity (a single injection) using standard laboratory apparatus. Moreover, this technique is readily applied to a major target in complex tissue engineering: the osteochondral interface. A bone morphogenetic protein 2 gradient, presented across a gelatin methacryloyl hydrogel laden with human mesenchymal stem cells, is used to locally stimulate osteogenesis and mineralization in order to produce integrated osteochondral tissue constructs. The versatility and accessibility of this fabrication platform should ensure widespread applicability and provide opportunities to generate other gradient materials or interfacial tissues.
Electrochemical CO2 Reduction Using Electrons Generated from Photoelectrocatalytic Phenol Oxidation
Authors: Guo Chenyan , He Peng , Cui Rongrong , Shen Qi , Yang Nianjun , Zhao Guohua 
Published: March 2019

AbstractElectrochemical CO2 reduction (ECCO2R) requires electrons, for example, from oxygen evolution reaction (OER). However, such a multiple‐electron‐involved reaction is complicated and kinetically slow, leading to high overpotential. Herein, OER is replaced with photoelectrocatalytic phenol oxidation reaction (PECPOR) that provides electrons for ECCO2R. In an integrated cell, ECCO2R is conducted on the cathode of Cu nanowires and PECPOR is performed on the anode of SnO2 and Sb coated TiO2 nanotubes. Significant improvement of ECCO2R into CO and hydrocarbons is realized when PECPOR is conducted at a high current density. The use of this integrated system results in the reduction of the specific energy consumption by a factor of 51.33%, compared with the utilization of two half‐cells for individual ECCO2R and PECPOR. This study thus proposes a novel strategy to couple ECCO2R with PECPOR and eventually to tackle the problems of environmental pollution and energy crisis.
Collective Efficacy as a Key Context in Neighborhood Support for Urban Youth
Authors: Prince Dana M. , Hohl Bernadette , Hunter Bronwyn A. , Thompson Azure B. , Matlin Samantha L. , Hausman Alice J. , Tebes Jacob Kraemer 
Published: March 2019

AbstractNeighborhood context, including the physical and social environment, has been implicated as important contributors to positive youth development. A transactional approach to neighborhood asserts that place and people are mutually constitutive; negative perceptions of place are intrinsically bound with negative portrayals of stigmatized groups, including youth. Adult perceptions of neighborhood youth may contribute to an increased sense of alienation and youth antisocial behavior. This study uses street‐intercept interviews with adults (N = 408) to examine the relationship between neighborhood conditions and adult support for neighborhood youth. A path model was used to examine the direct and indirect relationship of neighborhood constructs (safety, aesthetic quality, and walkability) on adult support for neighborhood youth. Neighborhood aesthetic quality and the walking environment were directly associated with adult support for youth, whereas perceived safety was indirectly associated. Collective efficacy partially explained these relationships. Findings support theorized relationships between people and places; improvements to neighborhood physical environment may directly impact resident adults’ perceptions of neighborhood young people.
Doyle‐Kirmse Rearrangement Reactions of Difluoroacetates
Authors: Jana Sripati , Koenigs Rene M. 
Published: March 2019

AbstractIn this report, we describe an application of ethyl difluoroacetate‐substituted allylic sulfides in Doyle‐Kirmse rearrangement reactions that allow efficient access to valuable fluorinated small molecules with applications in total synthesis and drug discovery. A cheap and readily available rhodium catalyst or – in a metal‐free variant – visible light was used to generate a carbene intermediate to access rearrangement reactions in high yield.
Carbene‐Catalyzed Enantioselective Decarboxylative Annulations to Access Dihydrobenzoxazinones and Quinolones
Authors: Lee Ansoo , Zhu Joshua L. , Feoktistova Taisiia , Brueckner Alexander C. , Cheong Paul H.‐Y. , Scheidt Karl A. 
Published: March 2019

AbstractA direct decarboxylative strategy for the generation of aza‐o‐quinone methides (aza‐o‐QMs) by N‐heterocyclic carbene (NHC) catalysis has been discovered and explored. This process requires no stoichiometric additives in contrast with current approaches. Aza‐o‐QMs react with trifluoromethyl ketones through a formal [4+2] manifold to access highly enantioenriched dihydrobenzoxazin‐4‐one products, which can be converted to dihydroquinolones through an interesting stereoretentive aza‐Petasis–Ferrier rearrangement sequence. Complementary dispersion‐corrected density functional theory (DFT) studies provided an accurate prediction of the reaction enantioselectivity and lend further insight to the origins of stereocontrol. Additionally, a computed potential energy surface around the major transition structure suggests a concerted asynchronous mechanism for the formal annulation.
Selective oxidation of benzyl alcohol to benzaldehyde, 1‐phenylethanol to acetophenone and fluorene to fluorenol catalysed by iron (II) complexes supported by pincer‐type ligands: Studies on rapid degradation of organic dyes
Authors: Singh Ovender , Gupta Priyanka , Singh Anshu , Maji Ankur , Singh Udai P. , Ghosh Kaushik 
Published: March 2019

Hexacoordinated non‐heme iron complexes [FeII(L1)2](ClO4)2 (1) and [FeII(L2)2](PF6)2 (2) have been synthesized using ligands L1 = (E)‐2‐chloro‐6‐(2‐(pyridin‐2ylmethylene) hydrazinyl)pyridine and L2 = (E)‐2‐chloro‐6‐(2‐(1‐(pyridin‐2‐yl)ethylidene)hydrazinyl) pyridine]. These complexes are highly active non‐heme iron catalysts to catalyze the C (sp3)−H bonds of alkanes. These iron complexes have been characterized using ESI−MS analysis and molecular structures were determined by X‐ray crystallography. ESI − MS analysis also helped to understand the generation of intermediate species like FeIII−OOH and FeIV=O. DFT and TD−DFT calculations revealed that the oxidation reactions were performed through high‐valent iron center and a probable reaction mechanism was proposed. These complexes were also utilized for the degradation of orange II and methylene blue dyes.
Photoinitiated synthesis of poly(poly(ethylene glycol) methacrylate‐co‐diethyl amino ethyl methacrylate) superabsorbent hydrogels for dye adsorption
Authors: Alokour Mamoon , Yilmaz Elvan 
Published: March 2019

ABSTRACTRandom copolymers of poly(ethylene glycol) methacrylate (PEGM), and diethyl amino ethyl methacrylate (DEAEM) were synthesized at low, and high conversions by photoinitiation. Crosslinked poly(PEGM‐co‐DEAEM) samples were obtained, and characterized by FTIR, SEM, DSC, TGA, and elemental analyses. Swelling behavior of the copolymers revealed that the copolymers acted as superabsorbent hydrogels. The monomer reactivity ratios were calculated using Fineman Ross, Extended Kelen Tüdøs, and Mayo Lewis methods that gave r1(PEGM) = 0.90, r2(DEAEM) = 0.14 at low conversions. At high conversions r1 and r2 values were calculated as 1.01 and 0.40, respectively. Adsorption isotherms of methyl orange (MO) onto hydrogels were studied using Langmuir, Freundlich, and Temkin models. The experimental data fitted well with the Langmuir equation. The maximum adsorption capacity for MO was 212.7 mg g−1 at pH = 3. The adsorption data gave best fit with the pseudo‐second order kinetic model. Thermodynamic evaluation showed spontaneous nature for MO adsorption onto poly(PEGM‐co‐DEAEM) hydrogels. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47707.
Temperature controls phenology in continuously flowering Protea species of subtropical Africa
Authors: Daru Barnabas H. , Kling Matthew M. , Meineke Emily K. , van Wyk Abraham E. 
Published: March 2019

Premise of the StudyHerbarium specimens are increasingly used as records of plant flowering phenology. However, most herbarium‐based studies on plant phenology focus on taxa from temperate regions. Here, we explore flowering phenologic responses to climate in the subtropical plant genus Protea (Proteaceae), an iconic group of plants that flower year‐round and are endemic to subtropical Africa.MethodsWe present a novel, circular sliding window approach to investigate phenological patterns developed for species with year‐round flowering. We employ our method to evaluate the extent to which site‐to‐site and year‐to‐year variation in temperature and precipitation affect flowering dates using a database of 1727 herbarium records of 25 Protea species. We also explore phylogenetic conservatism in flowering phenology.ResultsWe show that herbarium data combined with our sliding window approach successfully captured independently reported flowering phenology patterns (r = 0.93). Both warmer sites and warmer years were associated with earlier flowering of 3–5 days/°C, whereas precipitation variation had no significant effect on flowering phenology. Although species vary widely in phenological responsiveness, responses are phylogenetically conserved, with closely related species tending to shift flowering similarly with increasing temperature.DiscussionOur results point to climate‐responsive phenology for this important plant genus and indicate that the subtropical, aseasonally flowering genus Protea has temperature‐driven flowering responses that are remarkably similar to those of better‐studied northern temperate plant species, suggesting a generality across biomes that has not been described elsewhere.
Smart Microdevices Laying “Breadcrumbs” to Find the Way Home: Chemotactic Homing TiO2/Pt Janus Microrobots
Authors: Kong Lei , Mayorga‐Martinez Carmen C. , Guan Jianguo , Pumera Martin 
Published: March 2019

AbstractSynthetic microrobots or micromotors are known to show “intelligent” behavior such as magnetotaxis, phototaxis, chemotaxis, active detection, and chemical communication. Herein, we present the concept of micromotors laying “breadcrumbs”; that is, these micromachines can move/return to a home position without external guidance after their external energy input is stopped. As a demonstration, TiO2/Pt Janus micromotors that move forward with UV light can return back following the previous path when the UV light is turned off. Such autonomy of motion opens the door for truly independent applications of micromotors in the “deliver‐and‐return” fashion.
Suboptimal time management of discrete event systems with uncontrollable events modeled by Petri nets
Authors: Yazdani Mojtaba , Dideban Abbas 
Published: March 2019

AbstractPreventing systems from entering to forbidden states is a crucial issue in discrete event systems control. Adding supervisors to the system is a common method to avoid entering to forbidden states. In discrete event systems modeled by Petri net adding a supervisor could be done by means of control places. Since, the time is not considered in designing this supervisor, in presence of uncontrollable transitions adding control places can lead to increase the operation time of the system modeled by timed Petri net. Because, the firing of some transitions is prevented when it is not necessary. So, to design a more efficient controller, we will be required to use time information of the system component. Therefore, in this paper, a method for optimizing the time behavior of a supervised timed Petri net will be proposed. To obtain an efficient operation, some timed places as timer will be added to the net. The time of this timer places is calculated to permit firing of some controllable transitions in order to enter into some weakly forbidden states while entering to forbidden states is prevented. This concept leads to increase the speed of system as well as obtain an acceptable operation. This method can be applied for all systems modeled by Petri nets. The efficiency of proposed approach will be discussed and validated with a case study.
Computation of controllability and observability Gramians in modeling of discrete‐time noncommensurate fractional‐order systems
Authors: Rydel Marek , Stanisławski Rafał 
Published: March 2019

AbstractThis paper presents a new algorithm for computation of controllability and observability Gramians for an expanded state space form of integer‐order approximator to linear time‐invariant discrete‐time noncommensurate fractional‐order systems. The introduced methodology can significantly reduce the time complexity of the Gramians' calculation, being the main computational burden in modeling of discrete‐time fractional‐order systems by means of a high integer‐order expanded state space approximator and the balanced truncation reduction method. Simulation experiments illustrate an efficiency of the introduced methodology, in particular for low‐dimension fractional‐order systems and high implementation lengths.
A consolidated road map for economically gainful efficient utilization of agro‐wastes for eco‐friendly products
Authors: Gajula Sampath , Antonyraj Churchil A. , Odaneth Annamma A. , Srinivasan Kannan 
Published: March 2019

AbstractThe replacement of fossil carbon with biomass is currently crucial for ecological, environmental, and economic reasons. Although the use of biomass‐derived eco‐friendly products is appealing to the public and to industry, research is slow to meet the demand for it. This may be due to lack of awareness and cooperation among different sectors of science and stakeholders. This paper takes a holistic perspective. It discusses the importance of agro‐waste as a biomass resource and provides suggestions for its effective utilization to make economical and eco‐friendly products. Taking an interdisciplinary approach, it discusses the opportunities for direct, economical, and environmentally friendly research fields such as the modification of plant structure, increasing biomass yield, and conversion of agro‐waste to materials and chemicals. It suggests how these various fields can benefit industry and the public, and also discusses the importance of dialogue between the different stakeholders to accelerate growth in innovation, implementation, and development. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd
Determination of d‐limonene in mice plasma and tissues by a new GC–MS/MS method: Comparison of the pharmacokinetics and tissue distribution by oral and inhalation administration in mice
Authors: Chen Chen , Sheng Yunhua , Hu Yue , Sun Jie , Li Wei , Feng Hongmin , Tang Liming 
Published: March 2019

AbstractThe aim of the present study was to develop a method based on gas chromatography–tandem mass spectrometry (GC–MS/MS) to determine and quantify the d‐limonene in mouse plasma and tissue samples. This new method was validated for the quantification of d‐limonene with the linearity ranges 1.0–1000.0 ng/mL (r2 > 0.9952) for plasma samples and 5.0–5000.0 ng/g (r2 > 0.9940) for tissue samples. The intra‐ and inter‐day assay of precisions in plasma and tissues were <13.4% and the accuracies were within 91.1–105.8%. In the oral/inhalation administration pharmacokinetics and tissue distribution studies, the main pharmacokinetic parameters were the peak concentration = (97.150 ± 34.450)/(4336.415 ± 1142.418) ng/mL, the area under the curve = (162.828± 27.447)/(2085.721 ± 547.787) h ng/mL and the half‐life = (3.196 ± 0.825)/(0.989 ± 0.095) h. The tissue distribution of d‐limonene in mice after oral/inhalation administration demonstrated a decreasing tendency in different tissues (liver > kidney > heart > lung > spleen).