We analyze the binary gravitational microlensing event OGLE-2017-BLG-1130 (mass ratio q ∼ 0.45), the first published case in which the binary anomaly was detected only by the Spitzer Space Telescope. ...This event provides strong evidence that some binary signals can be missed by observations from the ground alone but detected by Spitzer. We therefore invert the normal procedure, first finding the lens parameters by fitting the space-based data and then measuring the microlensing parallax using ground-based observations. We also show that the normal four-fold space-based degeneracy in the single-lens case can become a weak eight-fold degeneracy in binary-lens events. Although this degeneracy is resolved in event OGLE-2017-BLG-1130, it might persist in other events.
The expression of hypoxia-inducible factor-1 (HIF-1) correlates with poor clinical outcomes and confers resistance to the apoptosis of the tumor cells that are exposed to hypoxia. Presently, the ...mechanism underlying this phenomenon is poorly understood. In this study we provide evidence that transglutaminase 2 (TG2), an enzyme that catalyses protein crosslinking reactions, is a transcriptional target of HIF-1 to enhance the survival of hypoxic cells. We found that hypoxia induces TG2 expression through an HIF-1 dependent pathway and concurrently activates intracellular TG2. The hypoxic cells overexpressing TG2 showed resistance to apoptosis. Conversely, the hypoxic cells treated with either TG2 inhibitor or small interfering RNA (siRNA) became sensitive to apoptosis. Activation of TG2 in response to hypoxic stress inhibited caspase-3 activity by forming crosslinked multimer, resulting in insoluble aggregates. TG2 also activates nuclear factor (NF)-κB pathway after hypoxic stress, and thereby induces the expression of cellular inhibitor of apoptosis 2. The anti-apoptotic role of TG2 was further confirmed in vivo using xenografts in athymic mice. Our results indicate that TG2 is an antiapoptotic mediator of HIF-1 through modulating both apoptosis and survival pathways and may confer a selective growth advantage to tumor cells. These findings suggest that the inhibition of TG2 may offer a novel strategy for anticancer therapy. Oncogene (2010) 29, 356-367; doi: 10.1038/onc.2009.342; published online 19 October 2009 Keywords: apoptosis; caspase 3; hypoxia-inducible factor-1; NF-κB; transglutaminase 2
We analyze the combined Spitzer and ground-based data for OGLE-2017-BLG-1140 and show that the event was generated by a Jupiter-class planet orbiting a mid-late M dwarf that lies in the foreground of ...the microlensed Galactic-bar source star. The planet-host projected separation is , i.e., well beyond the snow line. By measuring the source proper motion from ongoing long-term OGLE imaging and combining this with the lens-source relative proper motion derived from the microlensing solution, we show that the lens proper motion is consistent with the lens lying in the Galactic disk, although a bulge lens is not ruled out. We show that while the Spitzer and ground-based data are comparably well fitted by planetary (i.e., binary-lens (2L1S)) and binary-source (1L2S) models, the combination of Spitzer and ground-based data decisively favors the planetary model. This is a new channel to resolve the 2L1S/1L2S degeneracy, which can be difficult to break in some cases.
We report the analysis of the first resolved caustic-crossing binary-source microlensing event OGLE-2016-BLG-1003. The event is densely covered by round-the-clock observations of three surveys. The ...light curve is characterized by two nested caustic-crossing features, which is unusual for typical caustic-crossing perturbations. From the modeling of the light curve, we find that the anomaly is produced by a binary source passing over a caustic formed by a binary lens. The result proves the importance of high-cadence and continuous observations, and the capability of second-generation microlensing experiments to identify such complex perturbations that are previously unknown. However, the result also raises the issues of the limitations of current analysis techniques for understanding lens systems beyond two masses and of determining the appropriate multiband observing strategy of survey experiments.
► EBSD micrographs show that more surface plastic deformation is observed in the surface layer of the UNSM-treated surface comparing to the untreated surface. ► The key point for realizing the ...surface nanocrystallization of a bulk material is to introduce interfaces into the surface layers, so that its microstructure is transformed into nano-sized crystallites. ► UNSM is an effective technology to realize the surface nanocrystallization on metallic materials.
It is well known that dimpled surface can improve tribological characteristics. The fundamental aim of the present research is to demonstrate the process of making micro-dimples by ultrasonic nanocrystalline surface modification (UNSM) technology and to evaluate its effects on tribological characteristics. Ball-on-disk test was performed in order to reveal the influence of mechanism and micro-dimples. UNSM-treated surface is compared to ground surface and friction coefficient of the UNSM-treated surface has been reduced by about 25%, which is a significant phenomenon in improving tribological properties of mating surfaces. Wear volume loss of UNSM-treated surface has also been reduced by about 60%. Scanning electron microscopy (SEM) and surface roughness profile measurement were utilized to study the worn surface.
ABSTRACT We report the discovery of a microlensing exoplanet OGLE-2012-BLG-0563Lb with the planet-star mass ratio of . Intensive photometric observations of a high-magnification microlensing event ...allow us to detect a clear signal of the planet. Although no parallax signal is detected in the light curve, we instead succeed at detecting the flux from the host star in high-resolution JHK′-band images obtained by the Subaru/AO188 and Infrared Camera and Spectrograph instruments, allowing us to constrain the absolute physical parameters of the planetary system. With the help of spectroscopic information about the source star obtained during the high-magnification state by Bensby et al., we find that the lens system is located at 1.3 kpc from us, and consists of an M dwarf (0.34 M ) orbited by a Saturn-mass planet (0.39 MJup) at the projected separation of 0.74 AU (close model) or 4.3 AU (wide model). The probability of contamination in the host star's flux, which would reduce the masses by a factor of up to three, is estimated to be 17%. This possibility can be tested by future high-resolution imaging. We also estimate the and colors of the host star, which are marginally consistent with a low metallicity mid-to-early M dwarf, although further observations are required for the metallicity to be conclusive. This is the fifth sub-Jupiter-mass ( ) microlensing planet around an M dwarf with the mass well constrained. The relatively rich harvest of sub-Jupiters around M dwarfs is contrasted with a possible paucity of ∼1-2 Jupiter-mass planets around the same type of star, which can be explained by the planetary formation process in the core-accretion scheme.
Objective
The purposes of this study were to isolate and characterize stem cells from inflamed pulp tissue of human functional deciduous teeth (iSHFD) and to evaluate the influence of fibroblastic ...growth factor‐2 (FGF‐2) on the regenerative potential.
Materials and methods
We successfully isolated mesenchymal stem cells (MSCs) from the inflamed dental pulp tissue of human deciduous teeth and demonstrated that their regenerative potential could be enhanced by the application of FGF‐2 (20 ng ml−1) during ex vivo expansion. Isolated stem cells expanded in FGF‐2 were characterized using a colony‐forming assay, proliferation, migration, in vitro differentiation, in vivo ectopic transplantation assay, and gene expression profiling.
Results
MSCs isolated from the inflamed pulp tissue of functional deciduous teeth potentially possess the qualities of those from human exfoliated deciduous teeth. FGF‐2 applied to iSHFD during expansion enhanced the colony‐forming efficiency of these cells, increased their proliferation and migration potential, and reduced their differentiation potential in vitro. However, the ectopic transplantation of iSHFD/FGF‐2 in vivo increased the formation of dentin‐like material.
Conclusion
FGF‐2 expansion of stem cells from inflamed pulp tissues of human deciduous teeth can be a good source of stem cells for future clinical applications and a novel way of using discarded inflamed tissues.
ABSTRACT We report the discovery of an extrasolar planet detected from the combined data of a microlensing event OGLE-2015-BLG-0051/KMT-2015-BLG-0048 acquired by two microlensing surveys. Despite the ...fact that the short planetary signal occurred in the very early Bulge season during which the lensing event could be seen for just about an hour, the signal was continuously and densely covered. From the Bayesian analysis using models of the mass function, and matter and velocity distributions, combined with information on the angular Einstein radius, it is found that the host of the planet is located in the Galactic bulge. The planet has a mass and it is orbiting a low-mass M-dwarf host with a projected separation . The discovery of the planet demonstrates the capability of the current high-cadence microlensing lensing surveys in detecting and characterizing planets.
Mass measurements of gravitational microlenses require one to determine the microlens parallax πE, but precise πE measurement, in many cases, is hampered due to the subtlety of the microlens-parallax ...signal combined with the difficulty of distinguishing the signal from those induced by other higher-order effects. In this work, we present the analysis of the binary-lens event OGLE-2017-BLG-0329, for which πE is measured with a dramatically improved precision using additional data from space-based Spitzer observations. We find that while the parallax model based on the ground-based data cannot be distinguished from a zero-πE model at the 2 level, the addition of the Spitzer data enables us to identify two classes of solutions, each composed of a pair of solutions according to the well-known ecliptic degeneracy. It is found that the space-based data reduce the measurement uncertainties of the north and east components of the microlens-parallax vector by factors ∼18 and ∼4, respectively. With the measured microlens parallax combined with the angular Einstein radius measured from the resolved caustic crossings, we find that the lens is composed of a binary with component masses of either (M1, M2) ∼ (1.1, 0.8) M or ∼(0.4, 0.3) M according to the two solution classes. The first solution is significantly favored but the second cannot be securely ruled out based on the microlensing data alone. However, the degeneracy can be resolved from adaptive optics observations taken ∼10 years after the event.
ABSTRACT In this paper, we demonstrate the severity of the degeneracy between the microlens-parallax and lens-orbital effects by presenting the analysis of the gravitational binary-lens event ...OGLE-2015-BLG-0768. Despite the obvious deviation from the model based on the linear observer motion and the static binary, it is found that the residual can be almost equally well explained by either the parallactic motion of the Earth or the rotation of the binary-lens axis, resulting in the severe degeneracy between the two effects. We show that the degeneracy can be readily resolved with the additional data provided by space-based microlens parallax observations. By enabling us to distinguish between the two higher-order effects, space-based microlens parallax observations will not only make it possible to accurately determine the physical lens parameters but also to further constrain the orbital parameters of binary lenses.
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