More ferroelectrics discovered by switching spectroscopy piezoresponse force microscopy?

The local hysteresis loop obtained by switching spectroscopy piezoresponse force microscopy (SS-PFM) is usually regarded as a typical signature of ferroelectric switching. However, such hysteresis loops were also observed in a broad variety of non-ferroelectric materials in the past several years, which casts doubts on the viewpoint that the local hysteresis loops in SS-PFM originate from ferroelectricity. Therefore, it is crucial to explore the mechanism of local hysteresis loops obtained in SS-PFM testing. Here we proposed that non-ferroelectric materials can also exhibit amplitude butterfly loops and phase hysteresis loops in SS-PFM testing due to the Maxwell force as long as the material can show macroscopic D-E hysteresis loops under cyclic electric field loading, no matter what the inherent physical mechanism is. To verify our viewpoint, both the macroscopic D-E and microscopic SS-PFM testing are conducted on a soda-lime glass and a non-ferroelectric dielectric material Ba0.4Sr0.6TiO3. Results show that both materials can exhibit D-E hysteresis loops and SS-PFM phase hysteresis loops, which can well support our viewpoint.Comment: 12 pages,4 figure

FINITE ELEMENT SIMULATION ANALYSIS OF STEEL TRUSS ARCH BRIDGE JACKING CONSTRUCTION

In this study, a spatial model of a steel truss arch bridge was established using the finite element software Midas/Civil to simulate and analyze the jacking construction process. The stress performance of the guide beam and main structure at each jacking stage was obtained. The results showed that in the first stage of jacking, the maximum stress and deflection values of the main girder were observed. The maximum stress on the upper edge of the main girder was 34.9MPa, and on the lower edge, it was -60.4MPa. The maximum deflection was -35.88mm. The maximum stress in the guide beam occurred during the jacking process and was -53.2MPa, corresponding to the cross-section at the root of the guide beam. The maximum deflection of the guide beam occurred in the maximum cantilever state and was -30.79mm. During the arch rib jacking process, the maximum stress was -49.4MPa. Both the maximum stress and deflection values were within the allowable range, indicating that the structure was in a safe state. This study provides a reference for similar bridge jacking construction projects

Regulation of Porcine Conceptus Survival and Growth by L-arginine

This study was conducted to test the hypothesis that dietary supplementation with L-arginine during early pregnancy will ameliorate embryonic loss in pigs. Gilts were bred at the second estrus, and housed individually in pens and fed twice daily 1 kg of a corn- and soybean meal-based diet supplemented with 0.0%, 0.4%, or 0.8% L-arginine (w/w) between d 0 and 25 of gestation (Experiment 1) or between d 14 and 25 of gestation (Experiments 2 and 3). At d 25 (Experiment 1 and 2) or d 60 (Experiment 3) of gestation, gilts were hysterectomized to obtain uteri and conceptuses. Total RNA and protein were extracted from the frozen tissues. Quantitative RT-PCR, western blotting, and microarray analyses were performed to determine the changes of gene expression at mRNA and protein levels. Dietary supplementation with 0.8% L-arginine between d 0 and 25 of gestation decreased uterine weight, total number of fetuses, number of corpora lutea (CL), total fetal weight, total volume of allantoic and amniotic fluids, concentrations of progesterone in maternal plasma and allantoic fluid, compared to the control group. However, dietary supplementation with 0.4% or 0.8% L-arginine between d 14 and 25 of gestation increased total volume of amniotic fluid, total amounts of arginine in allantoic and amniotic fluids, total amounts of fructose and most amino acids in amniotic fluid, placental growth, and the number of viable fetuses per litter by 2. Dietary supplementation with 0.4% or 0.8% L-arginine between d 14 and 25 of gestation increased the total number of fetuses and number of live fetuses, rate of embryonic survival, and volumes of allantoic and amniotic fluids in gilts with 15 to 18 CL on d 60 of gestation compared with the control group. The abundance of placental protein and expression of mRNA related to the genes for arginine transport and metabolism, including cationic amino acid transporter 1, endothelial nitric oxide synthase (NOS3), phosphorylated-NOS3, ornithine decarboxylase, and guanosine triphosphate cyclohydrolase-I was increased by dietary supplementation with 0.8% L-arginine between d 0 and 25 of gestation. The abundance of total and phosphorylated mechanistic target of rapamycin was also enhanced by dietary 0.8% L-arginine supplementation between d 0 and 25 of gestation. Microarray analysis revealed that supplementation with 0.8% arginine between d 14 and 25 of gestation affected placental expression of 575 genes. Findings from the current study not only advance basic knowledge of mammalian reproductive biology, but also have important implications for developing practical means to enhance fertility in female pigs

RIS-Aided Wireless Communications: Prototyping, Adaptive Beamforming, and Indoor/Outdoor Field Trials

The prospects of using a Reconfigurable Intelligent Surface (RIS) to aid wireless communication systems have recently received much attention from academia and industry. Most papers make theoretical studies based on elementary models, while the prototyping of RIS-aided wireless communication and real-world field trials are scarce. In this paper, we describe a new RIS prototype consisting of 1100 controllable elements working at 5.8 GHz band. We propose an efficient algorithm for configuring the RIS over the air by exploiting the geometrical array properties and a practical receiver-RIS feedback link. In our indoor test, where the transmitter and receiver are separated by a 30 cm thick concrete wall, our RIS prototype provides a 26 dB power gain compared to the baseline case where the RIS is replaced by a copper plate. A 27 dB power gain was observed in the short-distance outdoor measurement. We also carried out long-distance measurements and successfully transmitted a 32 Mbps data stream over 500 m. A 1080p video was live-streamed and it only played smoothly when the RIS was utilized. The power consumption of the RIS is around 1 W. Our paper is vivid proof that the RIS is a very promising technology for future wireless communications.Comment: 13 pages, 18 figures, submitte

On the Migration Origin of the Hercules Moving Group with GAIA, LAMOST, APOGEE, and GALAH Surveys

Using Gaia DR3 data and the wavelet transformation technique, we study the substructures of the Hercules moving group (HMG): Hercules 1 (H1) and Hercules 2 (H2). Spectroscopic survey data from LAMOST, APOGEE, and GALAH are used to obtain metallicities and ages of stars belonging to the HMG. Our analysis leads to several key findings as follows: ($a$) the HMG is on average richer in metallicity than the Galactic disk, with H2 being metal richer than H1; ($b$) the HMG likely has a radial metallicity gradient distinct from that of the disk; ($c$) the HMG is on average older than the disk, with H2 being older than H1; ($d$) the HMG likely has a radial age gradient distinct from that of the disk; and ($e$) the metallicity and age distributions of the HMG depend mainly on the Galactic radius but show no dependence on the azimuthal velocity. Taken all together, we conclude that the HMG is composed primarily of stars undergoing radial migration. We suggest that the HMG is associated with a higher-order dynamical resonance of the bar of the Galaxy.Comment: 15 pages, 6 figures. Accepted by Ap

Long Non-Coding RNA Urothelial Carcinoma Associated 1 Promotes Proliferation, Migration and Invasion of Osteosarcoma Cells by Regulating microRNA-182

Background/Aims: Previous studies demonstrated the oncogenic roles of lncRNA UCA1 in osteosarcoma. This study aimed to explore the internal molecular mechanism of UCA1 on promoting osteosarcoma cell proliferation, migration and invasion. Methods: qRT-PCR was conducted to measure the expression levels of UCA1, miR-182 and TIMP2. Cell transfection was used to change the expression levels of UCA1, miR-182 and TIMP2. Cell viability, migration, invasion and apoptosis were measured using CCK-8 assay, two-chamber migration (invasion) assay and Guava Nexin assay, respectively. The associations between UCA1, miR-182 and iASPP were analyzed by dual luciferase activity assay. The protein expression levels of key factors involved in cell apoptosis, PI3K/AKT/GSK3β pathway and NF-κB pathway, as well as p53, Rb, RECQ family and iASPP were evaluated by western blotting. Results: UCA1 was highly expressed in osteosarcoma MG63 and OS-732 cells. Knockdown of UCA1 inhibited OS-732 cell viability, migration and invasion, but promoted cell apoptosis. miR-182 was up-regulated in OS-732 cells after UCA1 knockdown and participated in the effects of UCA1 on OS-732 cells. TIMP2 was downstream factor of miR-182 and involved in the regulatory roles of miR-182 on OS-732 cell viability, migration, invasion, apoptosis, as well as PI3K/AKT/GSK3β and NF-κB pathways. UCA1 knockdown up-regulated p53, Rb and RECQL5 levels in OS-732 cells, while down-regulated the expression of iASPP. TGF-β or TNF-α treatment could enhance the expression of UCA1 in OS-732 cells. Conclusion: Our research verified that UCA1 exerted oncogenic roles in osteosarcoma cells by regulating miR-182 and TIMP2, as well as PI3K/AKT/GSK3β and NF-κB pathways