All Sky Camera and Fabry-Perot Interferometer Observations in the Northern Polar Cap

Wu Qian,Killeen Timothy L.,Solomon Stanley C.,McEwen Donald J.,Guo, Weiji Korea Institute of Ocean ScienceTechnology 2002 Ocean and Polar Research Vol.24 No.3

We report all sky camera and Fabry-Perot interferometer (FPI) observations of mesospheric gravity waves and a 12-hour wave at Resolute $(75^{\circ}N)$ and a joint observation of 10-hour wave with Eureka $(80^{\circ}N)$. All sky camera observations showed a low occurrence of mesosphere gravity waves during equinoxes, which is similar to the mid-latitude region. A slightly higher occurrence near solstice appears to indicate that gravity waves are not filtered out by the neutral wind in the winter. The FPI observation of a 12-hour wave showed amplitude variations from day to day. The phase of the wave is mostly stable and consistent with the GSWM prediction in the winter. The phase shifts with season as predicted by the GSWM. Four events of the 12-hour wave were found in spring with amplitudes larger than the GSW predictions. The FPls at Resolute and Eureka also observed a wave with period close to 10 hours. The 10-hour wave maybe the result of the non-linear interaction between the semi-diurnal tide and the quasi-two day wave. Further studies are under way. Overall, the combined Resolute and Eureka observation have revealed some new fractures about the mesospheric gravity wave, tidal wave, and other oscillations.

All Sky Camera and Fabry-Perot Interferometer Observations in the Northern Polar Cap

Qian Wu,Timothy L. Killeen,Stanley C. Solomon,Donald J. McEwen,Weiji Guo 한국해양과학기술원 2002 Ocean and Polar Research Vol.24 No.3

We report all sky camera and Fabry-Perot interferometer (FPI) observations of mesospheric gravity waves and a 12-hour wave at Resolute (75oN) and a joint observation of 10-hour wave with Eureka (80oN). All sky camera observations showed a low occurrence of mesosphere gravity waves during equinoxes, which is similar to the mid-latitude region. A slightly higher occurrence near solstice appears to indicate that gravity waves are not filtered out by the neutral wind in the winter. The FPI observation of a 12-hour wave showed amplitude variations from day to day. The phase of the wave is mostly stable and consistent with the GSWM prediction in the winter. The phase shifts with season as predicted by the GSWM. Four events of the 12-hour wave were found in spring with amplitudes larger than the GSWM predictions. The FPIs at Resolute and Eureka also observed a wave with period close to 10 hours. The 10-hour wave maybe the result of the non-linear interaction between the semi-diurnal tide and the quasi-two day wave. Further studies are under way. Overall, the combined Resolute and Eureka observation have revealed some new features about the mesospheric gravity wave, tidal wave, and other oscillations.

Tumor-suppressive miRNA-135a inhibits breast cancer cell proliferation by targeting ELK1 and ELK3 oncogenes

Akhlaq Ahmad,Weijie Zhang,Mingming Wu,Sheng Tan,Tao Zhu 한국유전학회 2018 Genes & Genomics Vol.40 No.3

Breast cancer is the most common malignant disease amongst women. miRNAs are small, non-coding RNAs that regulate gene expression, thus have the potential to play an important role during cancer development. Emerging evidence shows that miR-135a is down-regulated in breast cancer cells, but the functional roles of miR-135a in breast cancer cells remains unexplored. For this purpose, we investigated the expression of miR-135a in breast cancer cells and explored its functional role during breast cancer progression. In vitro study showed that miR-135a may be a novel tumor suppressor. Further studies showed that transcription factors ELK1 and ELK3 are direct target genes of miR-135a that modulates the suppressive function of miR- 135a in breast cancer cells. Induced expression of miR-135a significantly downregulated the expression of ELK1 and ELK3 both at mRNA and protein levels. Furthermore, the effect of miR-135a in MCF-7 and T47D cells was investigated by the overexpression of miR-135a mimics. In vitro, induced expression of miR-135a in breast cancer cells inhibited cell Proliferation and clongenicity. Moreover, a luciferase activity assay revealed that miR-135a could directly target the 3′-untranslated region (3′ UTRS) of ELK1 and ELK3 oncogenes. In addition, rescue experiment demonstrated that the promoted cell growth by transcription factors ELK1 and ELK3 was attenuated by the over-expression of miR-135a. Our study demonstrates that miR-135a regulates cell proliferation in breast cancer by targeting ELK1 and ELK3 oncogenes, and suggests that miR-135a potentially can act as a tumor suppressor.

Tension-Compression Asymmetry of a Rolled Mg-Y-Nd Alloy

Bo Song,Hucheng Pan,Weijie Ren,Ning Guo,Zehong Wu,Renlong Xin 대한금속·재료학회 2017 METALS AND MATERIALS International Vol.23 No.4

In this work, tension and compression deformation behaviors of rolled and aged Mg-Y-Nd alloys were investigated. The microstructure evolution and plastic deformation mechanism during tension and compression wereanalyzed by combined use of electron backscatter diffraction and a visco-plastic self-consistent crystal plasticitymodel. The results show that both rolled and aged Mg-Y-Nd sheets show an extremely low yield asymmetry. Elimination of yield asymmetry can be ascribed to the tilted basal texture and suppression of {10-12} twinning. The rolled sheet has almost no yield asymmetry, however exhibits a remarkable strain-hardening behavior asymmetry. Compressed sample shows lower initial strain hardening rate and keeps higher strain hardening rate at thelater stage compared with tension. The strain-hardening asymmetry can be aggravated by aging at 280 C. It is consideredthe limited amount of twins in compression plays the critical role in the strain hardening asymmetry. Finally, the relevant mechanism was analyzed and discussed.

Sensitivity Experiments of the Local Wildland Fire with WRF-Fire Module

Lai Shaojun,Chen Haishan,He Fen,Wu Weijie 한국기상학회 2020 Asia-Pacific Journal of Atmospheric Sciences Vol.56 No.4

In this paper, it is discussed the performance of theWeather Research and Forecasting (WRF) model coupled with a wildland firebehavior module (WRF-Fire model) by the observational data collected in an experiment with a low-intensity prescribed fire (LIPF) conducted in the New Jersey Pine Barrens (NJPB) on March 6, 2012. The sensitivity experiments of theWRF-Fire model are carried out to investigate the interactions between the wildland fire and the atmospheric planetary boundary layer. The twoway WRF-Fire model conofigured with fire and large eddy simulation (LES) mode is used to explore the fire characteristics of perimeter shape, intensity, spread direction and external factors ofwind speed, and to discuss how these external parameters affect the fire, and the interactions between the atmosphere and fire. Results show that the sensitive experiments can provide the meteorological elements close to observations, such as the temperatures, winds and turbulent kinetic energy near the surface in the vicinity of the fire. The simulations also can reproduce the fire spread shape and speed, fire intensity, and heat flux released from fire. From the view of energy, the heat flux feed back to the atmospheric model and heat the air near the surface, which will induce strong thermal and dynamic instability causing strong horizontal convergence and updraft, and form the fire-induced convective boundary layer. The updraft will be tilted downstream of the fire area based on the height of the ambient winds. Due to the effect of the this updrafts, the particles and heat from the fuel combustion can be transported to the downwind and lateral regions of the fire area. Meanwhile, there is a downdraft flow with higher momentum nearby the fire line transporting fresh oxygen to the near surface, which will increase winds behind the fire line, accelerate the rate of spread (ROS) and make the fire spread to a larger area. Ultimately, a fire-induced climate is established.

Vapour–liquid–solid growth of monolayer MoS₂ nanoribbons

Li, Shisheng,Lin, Yung-Chang,Zhao, Wen,Wu, Jing,Wang, Zhuo,Hu, Zehua,Shen, Youde,Tang, Dai-Ming,Wang, Junyong,Zhang, Qi,Zhu, Hai,Chu, Leiqiang,Zhao, Weijie,Liu, Chang,Sun, Zhipei,Taniguchi, Takaaki,Os Nature Publishing Group UK 2018 Nature Materials Vol.17 No.6

<P>Chemical vapour deposition of two-dimensional materials typically involves the conversion of vapour precursors to solid products in a vapour-solid-solid mode. Here, we report the vapour-liquid-solid growth of monolayer MoS2, yielding highly crystalline ribbons with a width of few tens to thousands of nanometres. This vapour-liquid-solid growth is triggered by the reaction between MoO3 and NaCl, which results in the formation of molten Na-Mo-O droplets. These droplets mediate the growth of MoS2 ribbons in the 'crawling mode' when saturated with sulfur. The locally well-defined orientations of the ribbons reveal the regular horizontal motion of the droplets during growth. Using atomic-resolution scanning transmission electron microscopy and second harmonic generation microscopy, we show that the ribbons are grown homoepitaxially on monolayer MoS2 with predominantly 2H-or 3R-type stacking. Our findings highlight the prospects for the controlled growth of atomically thin nano-structure arrays for nanoelectronic devices and the development of unique mixed-dimensional structures.</P>

Effects of Black Raspberry Supplementation on Methylation Pathways in Vav-cre Asxl1fl/fl Tet2fl/fl Double Knockout Mice with Early-stage Myelodysplastic Syndrome

Athena Dong,Yi-Wen Huang,Ben Niu,Ruiling Liu,Weijie Wu,Haiyan Gao,Jianhua Yu 대한암예방학회 2023 Journal of cancer prevention Vol.28 No.4

Myelodysplastic syndromes (MDS) are a subset of myeloid malignancies defined by clonality of immature hematopoietic stem cells that leads to faulty blood cell development. These syndromes can lead to an increased risk of infection and may transform into acute myeloid leukemia, making it critical to determine effective treatments for the condition. While hypomethylating agents such as azacitidine and decitabine, as well as stem cell transplants, have been delineated as favored treatments for MDS, not all patients are physiologically receptive to these treatments. However, black raspberries (BRBs) have been shown to exert hypomethylating effects in various malignancies, with minimal adverse effects and thus a broader range of potential candidacies. This study aimed to investigate the potential of BRBs to exert such effects on MDS using Addition of Sex Combs Like/Tet Methylcytosine Dioxygenase 2 (Asxl1/Tet2) double knockout mice (Vav-cre Asxl1fl/fl Tet2fl/fl), which typically manifest symptoms around 25 weeks of age, mirroring genetic mutations found in humans with MDS. Following a 12-week dietary supplementation of Vav-cre Asxl1fl/fl Tet2fl/fl mice with 5% BRBs, we observed both hyper- and hypomethylation at multiple transcription start sites and intragenic locations linked to critical pathways, including hematopoiesis. This methylation profile may have implications for delaying the onset of MDS, prompting a need for in-depth investigation. Our results emphasize the importance of exploring whether an extended BRB intervention can effectively alter MDS risk and elucidate the relationship between BRB-induced methylation changes, thus further unlocking the potential benefits of BRBs for MDS patients.