bluuebunny/crossref_metadata_2025_split huggingface dataset:
ISO2‐PU Honeycomb Porous Films with a Peculiar Crystalline Structure by the Breath Figure Method Promote Osteogenic Differentiation of Stem Cells
Authors: Yang Wei , Hong Yawen , Chen Yimei , Wang Yuanliang , Luo Yanfeng 
Published: July 2022

AbstractThe breath figure (BF) method is a handy strategy to prepare porous films. Linear shape memory polyurethanes (SMPUs) are among the most promising polymers for bone repair or regeneration. However, little attention has been paid to the fabrication of SMPU films by using the BF method. In this work, an amorphous SMPU containing isosorbide (ISO) in the long‐chain hard segments (ISO2‐PU) is fabricated into honeycomb porous films. Strikingly, a peculiar crystalline structure with a “Z” configuration and highly regional orientation is formed on the hexagonal holes of the porous films, which results in significantly enhanced mechanical properties. Moreover, the ISO2‐PU honeycomb porous films can markedly accelerate the osteogenic differentiation of rat mesenchymal stem cells, indicating that the porous films have great potentials as bone repair materials. It is further speculated that the Marangoni effect in the condensed water droplets and the molecular assembly of ISO2‐PU due to the strong hydrogen bonds and the chiral center effect of ISO are key contributors. This work, to the best of authors’ knowledge, is the first time that this special crystalline structure on BF‐based porous films is observed and also the first speculation that combines Marangoni effect with the microstructure of BF‐based porous films.
The transglutaminase 2 cancer cell survival factor maintains mTOR activity to drive an aggressive cancer phenotype
Authors: Chen Xi , Adhikary Gautam , Newland John J. , Xu Wen , Ma Emily , Naselsky Warren , Eckert Richard L. 
Published: July 2022

AbstractTransglutaminase 2 (TG2) is an important cancer stem‐like cell survival protein that is highly expressed in epidermal squamous cell carcinoma and drives an aggressive cancer phenotype. In the present study, we show that TG2 knockdown or inactivation results in a reduction in mammalian target of rapamycin (mTOR) level and activity in epidermal cancer stem‐like cells which are associated with reduced spheroid formation, invasion, and migration, and reduced cancer stem cell and epithelial–mesenchymal transition (EMT) marker expression. Similar changes were observed in both cultured cells and tumors. mTOR knockdown or treatment with rapamycin phenocopies the reduction in spheroid formation, invasion, and migration, and cancer stem cell and EMT marker expression. Moreover, mTOR appears to be a necessary mediator of TG2 action, as a forced expression of constitutively active mTOR in TG2 knockdown cells partially restores the aggressive cancer phenotype and cancer stem cell and EMT marker expression. Tumor studies show that rapamycin reduces tumor growth and cancer stem cell marker expression and EMT. These studies suggest that TG2 stimulates mTOR activity to stimulate cancer cell stemness and EMT and drive aggressive tumor growth.
Magnetic field strength dependent SNR gain at the center of a spherical phantom and up to 11.7T
Authors: Le Ster Caroline , Grant Andrea , Van de Moortele Pierre‐François , Monreal‐Madrigal Alejandro , Adriany Gregor , Vignaud Alexandre , Mauconduit Franck , Rabrait‐Lerman Cécile , Poser Benedikt A. , Uğurbil Kâmil , Boulant Nicolas 
Published: July 2022

PurposeThe SNR at the center of a spherical phantom of known electrical properties was measured in quasi‐identical experimental conditions as a function of magnetic field strength between 3 T and 11.7 T.MethodsThe SNR was measured at the center of a spherical water saline phantom with a gradient‐recalled echo sequence. Measurements were performed at NeuroSpin at 3, 7, and 11.7 T. The phantom was then shipped to Maastricht University and then to the University of Minnesota for additional data points at 7, 9.4, and 10.5 T. Experiments were carried out with the exact same type of birdcage volume coil (except at 3 T, where a similar coil was used) to attempt at isolating the evolution of SNR with field strength alone. Phantom electrical properties were characterized over the corresponding frequency range.ResultsElectrical properties were found to barely vary over the frequency range. Removing the influence of the flip‐angle excitation inhomogeneity was crucial, as expected. After such correction, measurements revealed a gain of SNR growing as B01.94 ± 0.16 compared with B02.13 according to ultimate intrinsic SNR theory.ConclusionsBy using quasi‐identical experimental setups (RF volume coil, phantom, electrical properties, and protocol), this work reports experimental data between 3 T and 11.7 T, enabling the comparison with SNR theories in which conductivity and permittivity can be assumed to be constant with respect to field strength. According to ultimate SNR theory, these results can be reasonably extrapolated to the performance of receive arrays with greater than about 32 elements for central SNR in the same spherical phantom.
Parametric research on the time step and spring stiffness in three‐dimensional discontinuous deformation analysis method
Authors: Fan Hongyun , Li Liping , Liu Hongliang , Ni Jian , Cheng Shuai , Zhou Hao 
Published: July 2022

AbstractThree‐dimensional discontinuous deformation analysis method (3D.DDA) is a dynamic calculation method based on the implicit solution. Inertial force is introduced in the solution process to ensure that the time variable is the real time variable, and springs are applied at the block boundary to avoid mutual intrusion between blocks. Therefore, the value of time step and contact spring stiffness directly affect the accuracy of 3D.DDA calculation results. Firstly, we analyzed the effects of the time step and contact spring stiffness on the numerical calculation results of the 3D.DDA method based on the theoretical formula derivation. Secondly, we studied the influence mechanism of time step on the simulation results of the 3D.DDA method individually based on the double block free falling model. And we determined the reasonable value area of time step. Then, considering the contacts between blocks, we studied the joint influence mechanism of time step and contact spring stiffness on the 3D.DDA simulation results based on the double block sliding model. And we analyzed the error between the 3D.DDA simulation value and the theoretical value under the conditions of different time step and contact spring stiffness. Based on that, we divided the combined value area of time step and contact spring stiffness into four regions (Q1, Q2, Q3, and Q4) and determined the optimal value area of time step and contact spring stiffness. At last, we carried out the slope rockfall model experiment and numerical simulation, and the trajectory of the falling rock in the numerical simulation was basically consistent with the experiment results, which verified the effectiveness of the optimal value area of time step and contact spring stiffness. The research results can provide a reference for the choice of the value of time step and contact spring stiffness in the numerical simulation based on the 3D.DDA method.
A length scale insensitive phase‐field model for fully coupled thermo‐mechanical fracture in concrete at high temperatures
Authors: Wu Jian‐Ying , Chen Wan‐Xin , Zhou Hao 
Published: July 2022

AbstractFracture in concrete at high temperatures involves complex thermo‐mechanical couplings and arbitrary crack evolution, imposing great challenges to its computational modeling. This work addresses a length scale insensitive phase‐field cohesive model for fully coupled thermo‐mechanical fracture in concrete at high temperatures. Both the thermal expansion and transient creep strain are accounted for in the kinematics. Based on the underlying phase‐field cohesive model for fracture in solids at ambient temperature, the temperature‐dependent mechanical properties of concrete, that is, Young's modulus, tensile and compressive strengths and fracture energy, and so forth, are all incorporated. In addition to the cracking‐induced mechanical damage mechanism represented by the crack phase‐field, the thermal deterioration mechanism is also considered by a temperature‐dependent thermal damage variable. The numerical implementation of the proposed model into the multi‐field finite element method is then briefly addressed. Several representative numerical examples, for example, thermally induced cracking in energy storage structures, thermal shock in quenched concrete plates, mode‐I and mixed‐mode failure of notched beams at high temperatures, and so forth, are presented for the validation. The effects of various expressions for the transient creep strain (TCS) on the global behavior of concrete structures are also studied. As in those purely mechanical problems, both the predicted crack pattern and global responses for all examples are insensitive to the incorporated phase‐field length scale. Being able to capture the fully coupled thermo‐mechanical fracture in concrete, the proposed phase‐field cohesive model, combined with a reliable hydro‐chemo‐thermal analysis, is promising in assessing the integrity and safety of concrete structures at high temperatures like fire scenarios.
High‐density polyethylene/zinc oxide nanocomposite with antibacterial and anti‐UV radiation properties to reduce evaporation from free surface waters
Authors: Najafi Niloufar , Abedi Koupai Jahangir , Karevan Mehdi , Mostajeran Mohsen 
Published: July 2022

AbstractClimate change, through rising temperatures, higher evaporation rates, and changes in rainfall, can significantly affect the availability of water resources. Evaporation losses from open‐air reservoirs can exacerbate the problem of water scarcity, making it difficult to conserve water. Accordingly, this research aimed to develop nano‐reinforced floating covers to reduce evaporation from free water surfaces. For this purpose, high‐density polyethylene (HDPE), and zinc oxide (ZnO) nanoparticles, via melt‐blending procedures, were used to fabricate the nanocomposites. The morphological, mechanical, antibacterial, and photo‐degradation responses of HDPE/ZnO nanocomposites were assessed, and the physicochemical parameters of water samples were also examined to ensure that nanocomposites did not negatively affect water quality. The results indicated that adding 1 wt% nanofiller increased the tensile strength, while flexural strength values were modestly improved by increasing nanofillers up to 10 wt%. The irradiated nanocomposites generally displayed significant enhancement not only in the tensile strength but also in the flexural strength. Meanwhile, the addition of ZnO to HDPE had no adverse effects on water quality, though contributing to the antibacterial performance of the specimens over the neat polymer. To conclude, the fabricated nanocomposite with 1 wt% ZnO could be proposed as a promising candidate to reduce evaporation losses from free water surfaces, especially in arid and semi‐arid areas.
A review on self‐healing polymers and polymer composites for structural applications
Authors: Cioffi M. Odila H. , Bomfim Anne S. C. , Ambrogi Veronica , Advani Suresh G. 
Published: July 2022

AbstractPolymer composites when employed for structural applications undergo dynamic stresses and strains that initiate fatigue‐induced microcracks, which by their coalescence cause the failure of the materials, thus limiting their service life. To overcome this hurdle, one of the recent approaches relies on the development of smart self‐healing polymers that, analogously to biological systems, can use damage as a trigger to activate the self‐repair phenomenon, thus extending their service life. This work reviews the self‐healing approach in polymer‐based materials for structural applications. It focuses on three main aspects, which are also explained with schematics that illustrate the mechanisms involved. The first aspect describes the different strategies adopted for self‐healing polymeric structures, the self‐healing agents used, as well as the reactions responsible for repairing the damage. The second part is focused on the methods used to disperse the self‐healing agents and catalysts within the polymer systems. The third section details the different self‐healing mechanisms and the effectiveness of self‐healing approaches in terms of mechanical and dynamical‐mechanical behavior of materials. Challenges and future research outlook highlighting the importance of relaxation time and fatigue characterization and to understand the mechanisms and possible improvements are also presented.
Development of single nucleotide polymorphism markers and genetic diversity in guava (Psidium guajava L.)
Authors: Diaz‐Garcia Luis , Padilla‐Ramírez José S. 
Published: July 2022

Societal impact statementThere are many understudied fruits of great economic and productive importance for regional agricultural hubs. Guava is an American fruit species with attractive nutritional and adaptability characteristics. However, in many countries like Mexico, its cultivation is still limited to small‐to‐medium size plantings and home gardens and depends on poorly controlled germplasm that diminishes productivity and expansion. Our study provides valuable insight to better understand guava diversity and generate high‐yielding, high‐quality, and better adapted materials. Supporting the study and development of understudied crops will provide us with more resources for facing climate change adversities and for diversifying cropping systems.Summary

Guava (Psidium guajava L.) is a fruit crop species native to tropical and subtropical regions of America with great productive and economic potential due to its extensive environmental adaptability, nutritional value, and medicinal properties. However, the lack of molecular resources for accelerated breeding, limited knowledge about its evolutionary and domestication history, and unfavorable policies have limited its genetic improvement and broader adoption as a commercial fruit crop.
Here, we present the first diversity study in guava employing genome‐wide single nucleotide polymorphisms (SNPs). Forty‐eight accessions collected from Mexico and other continents were examined with more than 6000 high‐quality SNP markers, which represents a marker density increase of ~30x compared with previous studies. Relationships between genetic groupings and geographic origins were not apparent in this diverse guava collection using principal component and structure analyses.
Extensive germplasm exchange among guava‐producing regions and limited varietal control at commercial plantations might have contributed to ambiguities when defining the true origin and identities of existing germplasm materials. However, an analysis of domestication syndrome traits (fruit size and sugar) by wild or improved germplasm revealed several putative genomic regions under selection.
Knowledge about germplasm origins and genetic relatedness, in conjunction with reliable molecular resources and better agronomic practices, is necessary to support breeding efforts and facilitate broader adoption of orphan crops such as guava, which have increasingly important roles in light of climate change adversities and in diversifying diets and food systems.
Improvement of tissue‐specific distribution and biotransformation potential of nicotinamide mononucleotide in combination with ginsenosides or resveratrol
Authors: Bai Long‐Bo , Yau Lee‐Fong , Tong Tian‐Tian , Chan Wai‐Him , Zhang Wei , Jiang Zhi‐Hong 
Published: July 2022

AbstractDecreased Nicotinamide adenine dinucleotide (NAD+) level has received increasing attention in recent years since it plays a critical role in many diseases and aging. Although some research has proved that supplementing nicotinamide mononucleotide (NMN) could improve the level of NAD+, it is still uncertain whether the NAD+ level in specific tissues could be improved in combination with other nutrients. So far, a variety of nutritional supplements have flooded the market, which contains the compositions of NMN coupled with natural products. However, the synergy and transformation process of NMN has not been fully elucidated. In this study, oral administration of NMN (500 mg/kg) combined with resveratrol (50 mg/kg) or ginsenoside Rh2&Rg3 (50 mg/kg) was used to validate the efficacy of appropriate drug combinations in mice. Compared with NMN alone, NMN combined with resveratrol could increase the levels of NAD+ in the heart and muscle by about 1.6 times and 1.7 times, respectively, whereas NMN coupled with ginsenoside Rh2&Rg3 could effectively improve the level of NAD+ in lung tissue for approximately 2.0 times. Our study may provide new treatment ideas for aging or diseases in cardiopulmonary caused by decreased NAD+ levels.
Distributed iterative learning temperature control for large‐scale buildings
Authors: He Xun , Shen Dong 
Published: July 2022

AbstractThis article investigates the distributed iterative learning control for heating ventilation and air condition (HVAC) systems. Large‐scale building HVAC systems consisting of several subsystems are generally disturbed by the external environment and random human activities. The control objective is to achieve all units of the large‐scale building consistently maintaining the desired temperature. A distributed learning control (DLC) scheme with a decreasing gain is proposed and analyzed for the first time. To accelerate convergence speed, an adaptation mechanism is introduced to generate an adaptive learning gain sequence. Then, an accelerated distributed learning control (ADLC) scheme is designed to improve the transient convergence performance. For the DLC scheme, the input error is proved convergent to zero in the mean‐square sense, whereas the convergence with probability 1 is proved for the ADLC scheme. Numerical results are presented to verify the effectiveness of the proposed schemes.
Maximum turn‐off control for discrete‐time linear systems
Authors: Iwata Takumi , Azuma Shun‐ichi , Ariizumi Ryo , Asai Toru 
Published: July 2022

AbstractWe aim to address the problem of finding a control input maximizing the time instants when all control channels take a zero‐value (are turned off) while stabilizing the system to zero over a given horizon length. This problem is called the maximum turn‐off control problem. To solve it, we reduce the problem into a block‐sparse optimization problem with respect to the control input sequence, where the norm of the control input sequence is the objective function that must be minimized. Because the problem is not convex, we introduce a relaxed problem based on the norm, which is a convex function, and characterize the equivalence relation between the original and relaxed problems using the so‐called block restricted isometry property (block‐RIP). Based on the equivalence, the solution can be obtained by solving the convex relaxed problem. However, the block‐RIP is not easy to interpret and verify. Thus, we propose the notion of sparse controllability Gramians, which is an extension of the controllability Gramians, and show that the block‐RIP can be interpreted by the eigenvalues of the sparse controllability Gramian. This study presents an easy‐to‐check condition of the block‐RIP. Moreover, the above control framework is extended to a model predictive control scheme. These results are demonstrated using numerical examples.
Comparison of the accuracy of two UAV‐mounted uncooled thermal infrared sensors in predicting river water temperature
Authors: Niwa Hideyuki 
Published: July 2022

AbstractMeasurement by a unmanned aerial vehicles (UAV) equipped with thermal infrared sensors has great potential as a new technique for understanding the spatial heterogeneity of river water temperature; however, the measurement technique has not been established yet. Therefore, this study measured surface and water temperatures using two uncooled thermal infrared sensors, which are commercially available, for 7 months, to obtain knowledge to establish a method for predicting the river water temperature using uncooled thermal infrared sensors mounted on UAVs. The survey covered a 500 m section upstream from the confluence of the Inukai River in the Katsura River of the Yodo River system, in Japan. DJI Zenmuse XT2 and MicaSense Altum were mounted on a DJI Matrice 300 at the same time and took images seven times at intervals of approximately 1 month between June 2021 and January 2022. The water temperature and depth were measured at several locations within the study area within 1.5 hr after the UAV acquisition. Then, the relationship between the measured water temperature and the surface temperature extracted from the thermal infrared orthorectified mosaic image was analyzed. Altum was more suitable than XT2 for obtaining thermal infrared orthorectified mosaic images with less inconsistencies among courses in the surface temperature range, and the difference in water temperature was also smaller, making it suitable for understanding the river water temperature. To predict water temperature from surface temperature, actual measured data of water temperature is necessary, but I demonstrated that it is possible to measure the river water temperature in a spatially continuous manner.
A New Blending Method for the Preparation of Macroporous Open‐cell Polyvinyl Formaldehyde Foams with High Water‐Absorption Capacity
Authors: Li Yuanpeng , Pu Taohong , Wu Xun 
Published: July 2022

AbstractA new blending method for the preparation of a series of macroporous open‐cell polyvinyl formaldehyde (PVF) foams is reported here. Mechanism of foam‐formation was detailedly analyzed and it was found that the addition of polyvinyl alcohol (PVA) with a low degree of polymerization was important and crucial for the formation of PVF foams. Further, the addition of PVA with a low degree of polymerization is beneficial for the improvement of water solubility. The structures and properties of PVF foams were investigated by Fourier transform infrared (FTIR), scanning electron microscope (SEM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The macroporous open‐cell PVF foams had a pore size ranging from 120.88 to 16.16 μm with an increased degree of acetalization and the water absorption capacity increased with the addition of PVA with a low degree of polymerization. PVF foams generally have higher thermal stability because of their cross‐linked network structure. The highest water absorption capacity of the PVF foam obtained presently can reach up to 960 wt%, which is much higher than most PVF foams reported so far.