bluuebunny/crossref_metadata_2025_split huggingface dataset:
Supercontinuum Generation in Media with Sign‐Alternated Dispersion
Authors: Zia Haider , Lüpken Niklas M. , Hellwig Tim , Fallnich Carsten , Boller Klaus‐J. 
Published: June 2020

AbstractWhen an ultrafast optical pulse with high intensity propagates through transparent material a supercontinuum can be coherently generated by self‐phase modulation, which is essential to many photonic applications in fibers and integrated waveguides. However, the presence of dispersion causes stagnation of spectral broadening past a certain propagation length, requiring an increased input peak power for further broadening. Overcoming such spectral stagnation will be key to achieve practical integrated supercontinuum devices. Here, a concept is presented to drive supercontinuum generation with significantly lower input power by counteracting spectral stagnation via repeatedly alternating the sign of group velocity dispersion along the propagation. The effect is experimentally demonstrated in dispersion alternating fiber in excellent agreement with modeling, revealing almost an order of magnitude reduced peak power compared to uniform dispersion. Calculations also reveal a similar power reduction with integrated optical waveguides, simultaneously with a significant increase in flat bandwidth, which is important for on‐chip broadband photonics.
Enhanced Mechanical and Shape Memory Properties of Poly(propylene glycol)‐Based Star‐Shaped Polyurethane
Authors: Xu Zhaozan , Cui Yangli , Li Tingting , Dang Haichun , Li Jianfeng , Cheng Fangqin 
Published: June 2020

AbstractA poly(propylene glycol)‐based star‐shaped thermoplastic shape memory polyurethane elastomer (STPU) is synthesized by bulk polymerization with the addition of trifunctional poly‐propylene glycerol (PPG‐3) to improve the mechanical and shape memory properties. The mechanical properties are enhanced significantly with the addition of PPG‐3. The tensile strength of STPU is up to 36.0 MPa, which is almost two times higher than that of linear polyurethane (18.4 MPa). The star‐shaped structure, reduction in microphase separation, and good phase compatibility of STPU are the reasons for the enhancement of mechanical properties. The branching degree of STPU (up to 1.83) is much higher than that of linear polyurethane (0.5). STPU shows higher shape memory fixity ratio (97.2%) at −10 °C and recovery ratio (96.7%) at 40 °C than TPU. Therefore, the design and synthesis of star‐shaped polyurethane is an effective approach for improving the mechanical and shape memory properties of polyurethane elastomer.
Sodium Citrate Kolbe Electrolysis Polymerization in Aqueous Solution with Controlled Molecular Weight Distribution
Authors: Liu Ting‐Ran , Hu Zhi‐Yang , Chen Jian‐Qiu , Zhao Yu‐Zeng , Ge Hong‐Hua 
Published: June 2020

AbstractControlled‐molecular‐weight‐distribution polymerization of sodium citrate in aqueous solution is successfully performed by Kolbe electrolysis reaction. It can be carried out in aqueous solution and no initiator and catalyst need to be added specially in this new polymerization procedure. The molecular weight of polymerization product linear rises with increasing conversion rate, and its distribution is maintained relatively narrowly (Mw/Mn < 1.55). The molecular weight and its distribution are obviously affected by a couple of elements, such as reaction temperature, as well as the kinds and amount of addition neutral salt ions in electrolysis solution. Kolbe electrolysis can realize the controlled‐molecular‐weight‐distribution polymerization of sodium citrate monomer effectively, which expands the scope of non‐olefin monomers used for controlled‐molecular‐weight‐distribution polymerization.
Preparation of Polyurethane‐Urea Elastomers Using Low Molecular Weight Aliphatic Diamines Enabled by Reversible CO2 Chemistry
Authors: Zhang Bo , Li Xiaoxiao , Tian Yumeng , Wang Jie , Zhao Xiaoli , Yang Xiaoniu 
Published: June 2020

AbstractThe use of low molecular weight (LMw) aliphatic diamines for the synthesis of polyurethane‐urea elastomers (PUUEs) is an effective method for introducing abundant, strong hydrogen bonds with the aim of improving the thermal and mechanical properties of PUUEs. However, the reaction between isocyanates and LMw aliphatic diamines is too rapid to produce PUUEs. In this study, PUUEs incorporating LMw aliphatic diamines as chain extenders are prepared via the reversible reaction of CO2 with diamines. The phase separation, thermal properties, and thermomechanical and mechanical properties of polyurethane materials are investigated as the chain extender changed from diol to diamine. Replacing the diol chain extenders with diamine results in the formation of more abundant and stronger hydrogen bonds in PUUEs, which enables the assembly of long range ordered structures and improved microphase separation. The tensile strengths of PUUEs, from 8.4 to 13 MPa, are much higher than their corresponding polyurethanes, owing to the physical crosslinks formed by the more and stronger hydrogen bonds in the PUUEs.
Poly(dl‐Lactic Acid)‐Based Linear Polyurethanes Capable of Forming Physical Crosslinking via UPy Quadruple Hydrogen Bonding Assembly
Authors: Chen Yimei , Meng Yanli , Luo Yanfeng , Wang Yuanliang 
Published: June 2020

AbstractLinear shape memory polyurethanes based on poly(dl‐lactic acid) (PDLLA) macrodiol (PDLLA‐SMPUs) have various advantages such as good processability, biodegradability, shape memory effect, and biocompatibility, yet the insufficient mechanical properties prevent their effective applications in bone repair. 2‐Ureido‐4[1H]‐pyrimidone (UPy) can form strong quadruple hydrogen bonding. Here, a new linear PDLLA‐SMPU containing pendant UPy units (UPy‐p‐PDLLA‐SMPU) is designed and synthesized. The pendant UPy units may dimerize to form physical crosslinking among UPy‐p‐PDLLA‐SMPU chains. As a result, UPy‐p‐PDLLA‐SMPU demonstrates both good processability and significantly higher mechanical properties than the corresponding linear PDLLA‐SMPU without pendant UPys. In addition, UPy‐p‐PDLLA‐SMPU shows excellent shape memory effect near body temperature, with a shape fixity ratio of up to 98.6% and a recovery ratio of up to 92.9%. This work provides a new strategy to design SMPUs integrating the merits of linear and crosslinked polyurethanes, and the obtained UPy‐p‐PDLLA‐SMPU is a promising material for bone tissue repair in view of the mechanical, thermal, and shape memory properties.
A Multiscale Approach for Estimating Permeability Properties of Polymers with Complex Aromatic Backbones: A Case Study on Diffusivity of Small Gas Molecules in Polyphenylene Ether
Authors: Sweere Augustinus J. M. , Patham Bhaskar , Sugur Vijayakumar , Handgraaf Jan‐Willem 
Published: June 2020

AbstractState‐of‐the‐art multiscale computational chemistry simulations is employed to predict diffusivity of small gaseous molecules in a generic polyphenylene ether (PPE). The diffusivities are obtained from trajectory analysis of gaseous molecules in molecular dynamics simulations using coarse‐grained dissipative particle dynamics (DPD) simulations to design the amorphous starting structure. Required intra‐ and intermolecular parameters of the DPD simulations are automatically generated using the automated fragmentation and parametrization protocol. A comparison of calculated diffusion coefficients with experimental data for five gaseous molecules in PPE shows adequate accuracy of computational‐chemistry‐based approaches in the prediction of diffusion coefficients. These estimates, validated against measurements reported in the literature, serve as proof of concept for applicability of these new multiscale modeling strategies for complex polymers with aromatic backbones.
Unconnected Body Accrual of Dietary Lipid and Protein in Rats Fed Diets with Different Lipid and Protein Content
Authors: Oliva Laia , Aranda Tania , Alemany Marià , Fernández‐López José‐Antonio , Remesar Xavier 
Published: June 2020

ScopeEating large amounts of fat is usually associated with fat accumulation. However, different types of diets (not only lipids) elicit different metabolic responses.Methods and resultsMale and female rats (10 week‐old) are distributed in four groups and fed for 1 month a standard diet (SD), or this diet enriched with either lipid (high‐fat diet, HF) or protein (high‐protein diet, HP), or a cafeteria diet (CAF). Both HF and CAF diets share the percentage of energy from lipids (40%) but these are different. Protein‐derived energy in the HP diet is also 40%. Feeding SD, HF, and HP diets does not result in differences in energy intake, energy expenditure, total body weight, or lipid content. However, the CAF‐fed groups show increases in these parameters, which are more marked in the male rats. The CAF diet increases the mass of adipose tissue while the HF diet does not.ConclusionDifferent diets produce substantial changes in the fate of ingested nutrient energy. Dietary lipids are not essential for sustaining an increase in body lipid (or adipose tissue) content. Body protein accrual is unrelated to dietary lipids and overall energy intake. Both protein and lipid accrual are more efficient in male rats.
A quantitative analysis of biomechanical lung model consistency using 5DCT datasets
Authors: Stiehl Brad , Lauria Michael , O'Connell Dylan , Hasse Katelyn , Barjaktarevic Igor Z. , Lee Percy , Low Daniel A. , Santhanam Anand P. 
Published: June 2020

PurposeLung biomechanical models are important for understanding and characterizing lung anatomy and physiology. A key parameter of biomechanical modeling is the underlying tissue elasticity distribution. While human lung elasticity estimations do not have ground truths, model consistency checks can and should be employed to gauge the stability of the estimation techniques. This work proposes such a consistency check using a set of 10 subjects.MethodsWe hypothesize that lung dynamics will be stable over a 2–3 min time period and that this stability can be employed to check biomechanical estimation stability. For this purpose, two sets of 12 fast helical free breathing computed tomography scans (FHFBCT) were acquired back‐to‐back for each of the subjects. A published breathing motion model [five‐dimensional CT (5DCT)] was generated from each set. Both of the models were used to generate two biomechanical modeling input sets: (a) The lung geometry at the end‐exhalation, and (b) the voxel displacement map that mapped the end‐exhalation lung geometry with the end‐inhalation lung geometry. Finite element biomechanical lung models were instantiated using the end‐exhalation lung geometries. The models included voxel‐specific lung tissue elasticity values and were optimized using a gradient search approach until the biomechanical model‐generated displacement maps matched those of the 5DCT voxel displacement maps. Finally, the two elasticity distributions associated with each of the patient 5DCTs were quantitatively compared. Because the end‐exhalation geometries differed slightly between the two scan datasets, the elasticity distributions were deformably mapped to one of the exhalation datasets.ResultsFor the 10 patients, on average, 90% of parenchymal voxels had <2 kPa Young’s modulus difference between the two estimations, with a mean voxel difference of only 0.6 kPa. Similarly, 97% of the parenchymal voxels had <2 mm displacement difference between the two models with a mean difference of 0.48 mm. Furthermore, overlapping elasticity histograms for voxels between −600 and −900 HU (parenchymal tissues) showed that the histograms were consistent between the two estimations.ConclusionIn this paper, we demonstrated that biomechanical lung models can be consistently estimated when using motion‐model based imaging datasets, even though the models were created from scans acquired at different breaths.
Paradoxes of person‐centred care: A discussion paper
Authors: Summer Meranius Martina , Holmström Inger K. , Håkansson Jakob , Breitholtz Agneta , Moniri Farah , Skogevall Sofia , Skoglund Karin , Rasoal Dara 
Published: June 2020

AbstractAimPrevious research has mainly focused on the advantages of PCC and less on its disadvantages. Hence, there is a need to further explore the recent research regarding PCC from both sides. Therefore, the aim of this paper is to elucidate the advantages and disadvantages of PCC.DesignDiscussion paper.MethodsWe searched relevant literature published January 2000–March 2018 in PubMed, Medline, CHINAL, Scopus and Web of Science.ResultsThe results showed that PCC can contribute to improved health and well‐being, improved mutual interaction in relationships, improved cost‐effectiveness and improved work environment, while the disadvantages can involve increased personal and financial costs, exclusion of certain groups, increased personal and financial costs, exclusion of staff's personhood and unfairness due to empathy. An analysis of the existing literature on PCC showed paradoxes, which call for further investigation.
Near infrared photopolymer for micro‐optics applications
Authors: Dika Ihab , Diot Frédéric , Bardinal Véronique , Malval Jean‐Pierre , Ecoffet Carole , Bruyant Aurélien , Barat David , Reig Benjamin , Doucet Jean‐Baptiste , Camps Thierry , Soppera Olivier 
Published: June 2020

AbstractNear infrared (NIR) activable photopolymers suitable for versatile fabrication of micro‐optical elements were developed. The first main objective of this article is to show that these new photopolymers can be used for microfabrication and investigate the parameters governing the microfabrication process. The impact of photonic, physico‐chemical, and chemical parameters is discussed. High quality microstructures with a good control over their size and shape are demonstrated. The second main objective is to show practical examples of microlenses and waveguides implemented on single core and multiple core optical fibers, VCSELs, and glass slides are then presented. The NIR photosensitivity of this negative tone photoresists allows using the device source itself as to start the crosslinking process, which constitutes a convenient approach for micro‐optics self‐positioning on NIR sources and justifies the interest of such NIR photopolymer for the fabrication micro‐optical elements and optical interconnects.
Nanoparticles of Iron Nitride Encapsulated in Nitrogen‐Doped Carbon Bulk Derived from Polyaniline/Fe2O3 Blends and Its Electrochemical Performance
Authors: He Tianqi , Tu Mengyuan , Zhang Junlei , Kong Lingbin , Ran Fen 
Published: June 2020

AbstractIron nitride nanoparticles encapsulated in nitrogen‐doped carbon bulk is fabricated by a simple costep nitridation of Fe2O3 and carbonization of polyaniline. The microstructure and elemental composition of the materials are analyzed by transmission electron microscope, scanning electron microscope, X‐ray diffraction, and X‐ray photoelectron spectroscopy. The pore size distribution and specific surface area of the materials are identified using nitrogen adsorption and desorption method. The results illustrate that iron nitride nanoparticles with 5–20 nm in size are uniformly dispersed in the carbon bulk. The presence of carbon bulk effectively prevents the agglomeration of iron nitride nanoparticles, making the electrochemical performance of iron nitride nanoparticles/carbon nitride composite nanomaterials superior to that of pure iron nitride nanomaterials. At a current density of 0.5 A g−1, the specific capacitance (257.5 F g−1) of the iron nitride nanoparticles/nitrogen‐doped carbon bulk is much higher than that (119.5 F g−1) of pure iron nitride.
Efficiency of budesonide delivery via a mesh nebulizer in an in‐vitro neonatal ventilator model
Authors: Esmaeilizand Rana , Rocha Taciano , Harrison Ava , Gray Shari , Fusch Gerhard , Dolovich Myrna , Mukerji Amit 
Published: June 2020

AbstractObjectiveTo determine the delivery efficiency of budesonide aerosol via a mesh nebulizer in a neonatal ventilator model.Design/MethodIn an in‐vitro ventilated neonatal model, budesonide suspension was administered using a mesh nebulizer. A collection filter was placed distal to the endotracheal tube and budesonide captured by the filter was measured using UV spectroscopy. The ventilator was, in turn, either on high frequency or conventional ventilation mode and the nebulizer was placed either proximal (close to the endotracheal tube) or distal (between the wet side of humidifier and the inspiratory circuit). Each combination (nebulizer position and ventilation mode) to assess budesonide delivery was tested five times.ResultsOverall delivery of budesonide to the distal end of the endotracheal tube a small percentage of the total dose administered. The deposition with conventional ventilation was 2.12% (±1.06) and 1.26% (±0.27), with proximal and distal placement of the nebulizer, respectively. With high‐frequency ventilation, the deposition percentages were 1.82% (±0.82) and 1.69% (±0.23), with proximal and distal nebulizer placement, respectively.ConclusionOnly a small percentage of administered budesonide is delivered to the distal endotracheal tube, irrespective of ventilation mode, and nebulizer placement.
Numerical Research on the Impinging Effect of Sequential Muzzle Blast Waves Formed by Successive Shooting at High Frequency
Authors: Li Pengfei , Zhang Xiaobing 
Published: June 2020

AbstractThe impingement of muzzle blast wave is an important engineering problem and has been widely discussed for decades. The problem becomes more complex when the cannon shots at a high frequency. An accumulation phenomenon of the impingement of multiple blast waves is observed. In this research, the numerical study on impinging flows, which are generated by the propellant gas released from the muzzle of a high‐frequency launch system, is achieved. The interior ballistics model is employed in the simulation of muzzle flow. In order to have insight into the effect of continuous impingement, three cases with different launch frequencies are studied and compared. Under the computational load of muzzle flow impingement, the dynamic response of monitoring equipment is discussed based on an elastic mechanics model, and the contribution of the impinging frequency to the damaging effect is analyzed. It can be concluded that the frequency of the muzzle flow impingement has an important influence on the damaging effect. Furthermore, the accumulation of impingement depends on the shooting frequency and the intensity of each impingement.
A C‐type lectin with dual‐CRD from Tribolium castaneum is induced in response to bacterial challenge
Authors: Bi Jingxiu , Ning Mingxiao , Li Jia , Zhang Ping , Wang Lumen , Xu Shi , Zhong Yi , Wang Ziyi , Song Qisheng , Li Bin 
Published: June 2020

AbstractBACKGROUNDC‐type lectins (CTLs), a group of pattern recognition receptors, are involved in regulating the immune response of insects and could be used as potential targets for pest control. However, information about roles of CTLs in the innate immunity of Tribolium castaneum, a serious, worldwide pest that damages stored grain products, is relatively scarce.RESULTSHere, a CTL with dual carbohydrate recognition domains (CRDs) containing a highly conserved WHD (Trp53‐His54‐Asp55) motif was identified in T. castaneum and named as TcCTL3. Spatiotemporal analysis showed that TcCTL3 was highly expressed in all developmental stages except early eggs, and mainly distributed in central nervous system and hemolymph. The transcript levels of TcCTL3 were significantly increased after lipopolysaccharide (LPS) and peptidoglycan (PGN) stimulation. Recombinant TcCTL3 was able to bind directly to LPS, PGN and all tested bacteria and induce a broad spectrum of microbial agglutination in the presence of Ca2+. The binding was shown mainly through CRD1 domain of TcCTL3. When TcCTL3 was knocked down by RNA interference, expression of nine antimicrobial peptides (AMPs) (attacin1, attacin2, attacin3, defensins1, defensins2, coleoptericin1, coleoptericin2, cecropins2 and cecropins3) and four transcription factors (TFs) (dif1, dif2, relish and jnk) were significantly decreased under LPS and PGN stimulation, leading to increased mortality of T. castaneum when infected with Gram‐positive Staphylococcus aureus or Gram‐negative Escherichia coli infection.CONCLUSIONTcCTL3 could mediate the immune response in T. castaneum via the pattern recognition, agglutination and AMP expression. These findings indicate a potential mechanism of TcCTL3 in resisting bacteria and provide an alternative molecular target for pest control. © 2020 Society of Chemical Industry
Confining Tiny MoO2 Clusters into Reduced Graphene Oxide for Highly Efficient Low Frequency Microwave Absorption
Authors: Wu Cao , Chen Zhaofeng , Wang Meiling , Cao Xun , Zhang Yong , Song Pin , Zhang Tianyuan , Ye Xinli , Yang Yong , Gu Weihua , Zhou Jiadong , Huang Yizhong 
Published: June 2020

AbstractHerein, a supermolecular‐scale cage‐confinement pyrolysis strategy is proposed to build two dielectric electromagnetic wave absorbents, in which MoO2 nanoparticles are sandwiched uniformly between porous carbon shells and reduced graphene oxide (RGO). Both sandwich structures are derived from hybrid hydrogels doped by two different crosslinkers (with/without oxygen bridge), which can precisely confine Mo source (e.g., PMo12). Without adding magnetic components, both absorbents exhibit excellent low frequency absorption performance in combination with electrically tunable ability and enhanced reflection loss value, which is superior over other relative 2D dielectric absorbers and satisfies the requirements of portable electronics. Notably, introducing oxygen bridges in the crosslinker generates a more stable confining configuration, which in turn renders its corresponding derivative exhibiting an extra multifrequency electromagnetic wave absorption trait. The intrinsic electromagnetic wave adjustment mechanism of the ternary hybrid absorbent is also explored. The result reveals that the elevated electromagnetic wave absorbing property is attributed to moderate attenuation constant and glorious impendence matching. The cage‐confinement pyrolysis route to fabricate 2D MoO2‐based dielectric electromagnetic wave absorbents opens a new path for the design of electromagnetic wave absorbents used in multi/low frequency.
Enhanced Thermoelectric Performance in Black Phosphorus Nanotubes by Band Modulation through Tailoring Nanotube Chirality
Authors: Chen Xin , Duan Shuai , Yi Wencai , Singh David J. , Guo Jiangang , Liu Xiaobing 
Published: June 2020

AbstractBlack phosphorus (BP) has attracted great attention for applications in thermoelectric devices, owing to its unique in‐plane anisotropic electrical and thermal properties. However, its limited conversion efficiency hinders practical application. Here, the thermoelectric properties of 1D BP nanotubes (BPNTs) with different tube chirality are investigated using first‐principles calculations and Boltzmann transport theory. The results reveal that variation of crystallographic orientation has a distinct impact on band dispersions, which provides a wide tunability of electronic transport. It is shown that (1,1)‐oriented BPNT structure can yield an order‐of‐magnitude enhanced thermoelectric figure of merit ZT at room temperature (as high as 1.0), compared with the bulk counterpart. The distinct enhancement is attributed to the favorable multiple band structures that lead to high carrier mobility of 2430 cm2 V−1 s−1. Further performance improvement can be realized by suitable doping, such as N‐alloying, reaching an increase of room‐temperature ZT by a factor of 3 over that of pristine BPNT. The work provides an applicable method to achieve band engineering design, and presents a new strategy of designing 1D BPNT that are promising candidates for flexible, eco‐friendly, and high‐performance thermoelectrics.