We study gamma-ray supernova remnant (SNR) W49B and its environment using recent radio and infrared data. Spitzer Infrared Spectrograph low resolution data of W49B shows shocked excitation lines of H ...sub(2) (0,0) S(0)-S(7) from the SNR-molecular cloud interaction. The H sub(2) gas is composed of two components with temperatures of ~260 K and ~1060 K, respectively. Various spectral lines from atomic and ionic particles are detected toward W49B. We suggest that the ionic phase has an electron density of ~500 cm super(-3) and a temperature of ~10 super(4) K by the spectral line diagnoses. The mid- and far-infrared data from MSX, Spitzer, and Herschel reveal a 151 + or - 20 K hot dust component with a mass of 7.5 + or - 6.6 x 10 super(-4)M sub(middot in circle) and a 45 + or - 4 K warm dust component with a mass of 6.4 + or - 3.2 M sub(middot in circle). The hot dust is likely from materials swept up by the shock of W49B. The warm dust may possibly originate from the evaporation of clouds interacting with W49B. We build the H i absorption spectra of W49B and four nearby H II regions (W49A, G42.90+0.58, G42.43-0.26, and G43.19-0.53) and study the relation between W49B and the surrounding molecular clouds by employing the 2.12 mu m infrared and CO data. We therefore obtain a kinematic distance of ~10 kpc for W49B and suggest that the remnant is likely associated with the CO cloud at about 40 km s super(-1).
Oral Organoids: Progress and Challenges Gao, X.; Wu, Y.; Liao, L. ...
Journal of Dental Research,
05/2021, Volume:
100, Issue:
5
Book Review, Journal Article
Peer reviewed
Oral organoids are complex 3-dimensional structures that develop from stem cells or organ-specific progenitors through a process of self-organization and re-create architectures and functionalities ...similar to in vivo organs and tissues in the oral and maxillofacial region. Recently, striking advancements have been made in the construction and application of oral organoids of the tooth, salivary gland, and tongue. Dental epithelial and mesenchymal cells isolated from tooth germs or derived from pluripotent stem cells could generate tooth germ–like organoids by self-organization in a specific culture system. Tooth organoids can also be constructed based on tissue engineering principles by seeding stem cells on a scaffold with the bioregulatory functions of odontogenic differentiation. Two main approaches have been used to construct salivary gland organoids: 1) incubation of salivary gland–derived stem/progenitor cells in a 3-dimensional culture system to form the structure of the gland through mimicking regenerative processes and 2) inducing of pluripotent stem cells to generate embryonic salivary glands by replicating the development process. Taste bud organoids can be generated by embedding isolated circumvallate papilla tissue in Matrigel with a mixture of growth factors, while lingual epithelial organoids have been constructed using lingual stem cells in a suitable culture system containing specific signaling molecules. These oral organoids usually maintain the main functions and characteristic structures of the corresponding organ to a certain extent. Furthermore, using cells isolated from patients, oral organoids could replicate specific diseases such as maxillofacial tumors and tooth dysplasia. Until now, oral organoids have been applied in the study of mechanisms of tooth development, pathology and regeneration of the salivary gland, and precision therapeutics for tongue cancer. These findings strongly demonstrate that the organoid technique is a novel paradigm for the study of the development, pathology, and regeneration of oral and maxillofacial tissue.
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CMK, NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
We provide a new distance estimate to the supernova remnant (SNR) Kes 73 and its associated anomalous X-ray pulsar (AXP) 1E 1841-045. 21 cm H i images and H i absorption/emission spectra from new VLA ...observations, and super(13)CO emission spectra of Kes 73 and two adjacent compact H ii regions (G27.276+0.148 and G27.491+0.189) are analyzed. The H i images show prominent absorption features associated with Kes 73 and the H ii regions. The absorption appears up to the tangent point velocity giving a lower distance limit to Kes 73 of 7.5 kpc, which has previously been given as the upper limit. In addition, G27.276+0.148 and G27.491+0.189 are at the far kinematic distances of their radio recombination line velocities. There is prominent H i emission in the range 80-90 km s super(-1) for all three objects. The two H ii regions show H i absorption at image84 km s super(-1), but there is no absorption in the Kes 73 absorption spectrum. This implies an upper distance limit of image9.8 kpc to Kes 73. This corrected larger distance to Kes 73/AXP 1E 1841-045 system leads to a refined age of the SNR of 500-1000 yr, and a image50% larger AXP X-ray luminosity.
Many studies have indicated an important implication of radiation-induced bystander effects (RIBEs) in cancer radiotherapy, but the detailed signalling remains unclear.
The roles of tumour growth ...factor-beta1 (TGF-β1) and miR-21 in medium-mediated RIBEs in H1299 non-small-cell lung cancer cells were investigated using DNA damage, changes in proliferation and levels of reactive oxygen species (ROS) as end points. SB431542, a specific inhibitor of TGF-β type 1 receptor kinases, was used to inhibit TGF-β1 pathways in irradiated and bystander cells. Exogenous miR-21 regulation was achieved through inhibitor or mimic transfection.
Compared with relative sham-radiation-conditioned medium, radiation-conditioned medium (RCM) from irradiated cells 1 h post radiation (1-h RCM) caused an increase in ROS levels and DNA damage in bystander cells, while 18-h RCM induced cell cycle delay and proliferation inhibition. All these effects were eliminated by TGF-βR1 inhibition. One-hour RCM upregulated miR-21 expression in bystander cells, and miR-21 inhibitor abolished bystander oxidative stress and DNA damage. Eighteen-hour RCM downregulated miR-21 of bystander cells, and miR-21 mimic eliminated bystander proliferation inhibition. Furthermore, the dysregulation of miR-21 was attenuated by TGF-βR1 inhibition.
The TGF-β1-miR-21-ROS pathway of bystander cells has an important mediating role in RIBEs in H1299 cells.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The interval process model describes a time-variant or dynamic uncertain parameter by the upper and lower bounds rather than the precise probability distribution at each time point, providing an ...effective structural dynamic uncertainty quantification model with insufficient sample information. By reference to the Karhunen-Loève (K-L) expansion for stochastic process and random field models, a novel expansion method for the interval process model, namely, the interval K-L expansion is proposed in this work. The interval K-L expansion describes the continuous uncertainty of the interval process in time domain by superposition of infinite deterministic time-related functions with uncorrelated interval coefficients, which makes the interval process model much more convenient to use. By introducing a splicing technique, the interval K-L expansion method for multiple correlated interval processes is also presented. Based on the interval K-L expansion, the vibration of structures subject to interval process excitations is analyzed, where the analytic formulation of dynamic response bounds for linear elastic systems and continuum structures are derived. Finally, several numerical examples are investigated to demonstrate the effectiveness of the proposed method.
•A novel interval K-L expansion is proposed for the interval process model.•The interval K-L expansion is applicable to multiple correlated interval processes.•A novel non-random vibration analysis is presented based on interval K-L expansion.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We report on the analysis of XMM-Newton observations of the non-thermal shell-type supernova remnant HESS J1731−347 (G353.6-0.7). For the first time the complete remnant shell has been covered in ...X-rays, which allowed direct comparison with radio and TeV observations. We carried out a spatially resolved spectral analysis of XMM-Newton data and confirmed the previously reported non-thermal power-law X-ray spectrum of the source with negligible variations of spectral index across the shell. On the other hand, the X-ray absorption column is strongly variable and correlates with the CO emission thus confirming that the absorbing material must be in the foreground and reinforcing the previously suggested lower limit on distance. Finally, we find that the X-ray emission of the remnant is suppressed towards the Galactic plane, which points to lower shock velocities in this region, likely due to the interaction of the shock with the nearby molecular cloud.
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FMFMET, NUK, UL, UM, UPUK
The historical supernova remnant (SNR) Tycho SN 1572 originates from the explosion of a normal Type Ia supernova that is believed to have originated from a carbon-oxygen white dwarf in a binary ...system. We analyze the 21 cm continuum, H I, and 12CO-line data from the Canadian Galactic Plane Survey in the direction of SN 1572 and the surrounding region. We construct H I absorption spectra to SN 1572 and three nearby compact sources. We conclude that SN 1572 has no molecular cloud interaction, which argues against previous claims that a molecular cloud is interacting with the SNR. This new result does not support a recent claim that dust, newly detected by AKARI, originates from such an SNR-cloud interaction. We suggest that the SNR has a kinematic distance of 2.5-3.0 kpc based on a nonlinear rotational curve model. Very high energy Delta *g-ray emission from the remnant has been detected by the VERITAS telescope, so our result shows that its origin should not be an SNR-cloud interaction. Both radio and X-ray observations support that SN 1572 is an isolated Type Ia SNR.
In the present study, we preformed a two-dimensional numerical simulation of the motion and coalescence of bubble pairs rising in the stationary liquid pool, using the moving particle semi-implicit ...(MPS) method. Moving particles were used to describe the liquid phase and the vapor phase was evaluated using real vapor sate equation. The bubble–liquid interface was set to be a free surface boundary which could be captured according to the motion and location of interfacial particles. The behaviors of coalescence between two identical bubbles predicted by the MPS method were in good agreement with the experimental results reported in the literature. Numerical results indicated that the rising velocity of the trailing bubble was larger than that of the leading bubble. Both of the leading bubble and the trailing bubble rose faster than the isolated bubble. After coalescence, the coalesced bubble showed velocity and volume oscillations. The time of the volume oscillations increased with increasing initial bubble diameter. The wake flow and vortex would form behind the coalesced bubble.
► Coalescence of bubble pairs was numerically investigated using the MPS method.► The bubble–liquid interface was captured by the motion of interfacial particles.► The leading bubble could influence the motion of the trailing bubble greatly.► Bubble deformation characteristics were obtained under various parametric ranges.► MPS method is competent in evaluating the complicated bubble dynamics.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In pursuit of lightweighting of automobiles and low emission of transportation, the efforts to develop high-strength, heat-resistant and fatigue-resistant Al alloys and/or composites have been ...ongoing. Here we report a novel Al matrix composite with ultrahigh strength reinforced by a three dimensional network of nano-AlN particles for the first time. The in-situ synthesized AlN particles are connected by twinning bonding chains and built up a three dimensional network strengthening Al matrix enormously like the skeleton to human body. The composite containing 16.4wt.% AlN particles shows excellent properties: the ultimate tensile strengths can be up to 518MPa at room temperature and 190MPa at 350 °C. This peculiar performance results from the novel spatial distribution of nano-scale AlN particles. Our findings in this work would help to develop a potential candidate for high-performance heat resistance light-metal based materials.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
We analyse the Suzaku X-ray Imaging Spectrometer data of the central region of supernova remnant G332.5-5.6. The X-ray data are well described by a single non-equilibrium ionization thermal model, ...vnei, with an absorbing hydrogen column density of 1.4
$^{+0.4}_{-0.1}$
× 1021 cm−2. The plasma is characterized by an electron temperature of 0.49
$^{+0.08}_{-0.06}$
keV with subsolar abundances for O (0.58
$^{+0.06}_{-0.05}$
solar value) and Fe (0.72
$^{+0.06}_{-0.05}$
solar value) and slightly overabundance for Mg (1.23
$^{+0.14}_{-0.14}$
solar value). It seems that the central X-ray emission originates from a projection effect or evaporation of residual clouds inside G332.5-5.6. We estimate a distance of 3.0 ± 0.8 kpc for G332.5-5.6 based on the extinction–distance relation. G332.5-5.6 has an age of 7–9 kyr.
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