Subclinical hypothyroidism (SCH) has been shown to be associated with microbiota. However, the association between SCH and oral microbiota has not yet been elucidated. The results of our previous ...clinical studies showed that Prevotella intermedia was abundant in the oral microbiota of SCH patients. This study aimed to investigate the relationship between SCH and oral microbiota, verify the pathogenicity of P. intermedia in SCH, and preliminarily explore the possible mechanism. The SCH mouse model with oral application of P. intermedia was established, and the variance in the mouse oral microbiota and changes in thyroid function and metabolism were detected in mice. Student’s t test and analysis of variance were used for statistical analysis. Oral application of P. intermedia changed the composition of the oral microbiota of SCH mice, which enhanced the damage to the thyroid and decreased the expression of functional genes of the thyroid. Moreover, P. intermedia decreased oxygen consumption and aggravated glucose and lipid metabolism disorders in SCH mice. Glucose tolerance and insulin tolerance decreased, and the triglyceride content of the liver and inflammatory infiltration in adipose tissue increased in SCH mice after P. intermedia stimulation. Mechanistically, P. intermedia increased the proportion of CD4+ T cells in cervical lymph nodes and thyroids in SCH mice. Th1 cells were suggested to play an important role in the pathogenesis of SCH involving P. intermedia. In conclusion, P. intermedia aggravated SCH manifestations, including thyroid dysfunction and glucose and lipid metabolism disorders, by causing immune imbalance in mice. This study sheds new light on the pathogenesis of SCH from the perspective of oral microbiota.
ABSTRACT
The dynamical state of galaxy clusters describes if clusters are relaxed dynamically or in a merging process of subclusters. Using archival images from the Chandra X-ray Observatory, we ...derive a set of parameters to describe the dynamical state for 964 galaxy clusters. Three widely used indicators for dynamical state, the concentration index c, the centroid shift ω, and the power ratio P3/P0 are calculated in the circular central region with a radius of 500 kpc. We also derive two adaptive parameters, the profile parameter κ and the asymmetry factor α, in the best fitted elliptical region. The morphology index δ is then defined by combining these two adaptive parameters, which indicates the dynamical state of galaxy clusters and has good correlations to the concentration index c, the centroid shift ω, the power ratio P3/P0, and the optical relaxation factor Γ. For a large sample of clusters, the dynamical parameters are continuously distributed from the disturbed to relaxed states with a peak in the between, rather than the bimodal distribution for the two states. We find that the newly derived morphology index δ works for the similar fundamental plane between the radio power, cluster mass, and the dynamical state for clusters with diffuse radio giant-haloes and mini-haloes. The offset between masses estimated from the Sunyaev–Zeld́ovich effect and X-ray images depends on dynamical parameters. All dynamical parameters for galaxy clusters derived from the Chandra archival images are available on http://zmtt.bao.ac.cn/galaxy_clusters/dyXimages/.
Global petroleum exploration is currently undergoing a strategic shift from conventional to unconventional hydrocarbon resources. Unconventional hydrocarbons in tight reservoirs show characteristics ...distinct from those of conventional hydrocarbon sources hosted in structural and stratigraphic traps. The characteristic features include the following: a hydrocarbon source and reservoir coexist; porosity and permeability are ultra-low; nano-pore throats are widely distributed; hydrocarbon-bearing reservoir bodies are continuously distributed; there is no obvious trap boundary; buoyancy and hydrodynamics have only a minor effect, and Darcy's law does not apply; phase separation is poor; there is no uniform oil–gas–water interface or pressure system; and oil or gas saturation varies. Examples of unconventional hydrocarbon accumulations are the Mesozoic tight sandstone oil province and the Upper Paleozoic tight sandstone gas province in the Ordos Basin, north-central China. Generally, continuous hydrocarbon accumulation over a large area is a distinguishing characteristic of unconventional hydrocarbon sources. Because of the great potential of unconventional petroleum resources, it is believed that research on such resources will be at the forefront of the future development of petroleum geology.
ABSTRACT
The alignment between the brightest cluster galaxies (BCGs) and host clusters can reveal the mystery of the formation and evolution of galaxy clusters. We measure cluster orientations in ...optical based on the projected distribution of member galaxies and in X-ray by fitting the morphology of intracluster medium (ICM). Cluster orientations determined in the two wavelengths are generally consistent. The orientation alignment between BCGs and host clusters is confirmed and more significant than in previous works. We find that BCGs are more aligned with cluster orientations measured in X-ray than those from optical data. Clusters with a brighter BCG generally show a stronger alignment. We argue that the detected redshift evolution of the alignment is probably caused by observational bias rather than intrinsic evolution. The alignment is not related to the ellipticity of BCGs, and the richness, ellipticity, and dynamical state of host clusters. The strong alignment between BCGs and the morphology of ICMs may be the consequence of the co-evolution between the central massive galaxy and host clusters.
By cross-matching the currently largest optical catalogue of galaxy clusters and the NVSS radio survey data base, we obtain a large complete sample of brightest cluster galaxies (BCGs) in the ...redshift range of 0.05 < z ≤ 0.45, which have radio emission and redshift information. We confirm that more powerful radio BCGs tend to be these optically very bright galaxies located in more relaxed clusters. We derived the radio luminosity functions of the largest sample of radio BCGs, and find that the functions depend on the optical luminosity of BCGs and the dynamic state of galaxy clusters. However, the radio luminosity function does not show significant evolution with redshift.
The initial desertification in the Asian interior is thought to be one of the most prominent climate changes in the Northern Hemisphere during the Cenozoic era. But the dating of this transition is ...uncertain, partly because desert sediments are usually scattered, discontinuous and difficult to date. Here we report nearly continuous aeolian deposits covering the interval from 22 to 6.2 million years ago, on the basis of palaeomagnetic measurements and fossil evidence. A total of 231 visually definable aeolian layers occur as brownish loesses interbedded with reddish soils. This new evidence indicates that large source areas of aeolian dust and energetic winter monsoon winds to transport the material must have existed in the interior of Asia by the early Miocene epoch, at least 14 million years earlier than previously thought. Regional tectonic changes and ongoing global cooling are probable causes of these changes in aridity and circulation in Asia.
One of the most promising approaches to reach a high gain in inertial confinement fusion is the fast ignition scheme. In this scheme, a relativistic electron beam is generated; this passes through ...the imploded plasma and deposits parts of its energy in the core. However, the large angular spread of the relativistic electron beam and the poorly controlled compression of the target affect realization of the fast ignition technique. Here, we demonstrate that indirectly driven (that is, driven by X-rays generated inside a gold hohlraum) implosions with a ‘high-foot’ and a short-coast time of less than 200 ps allow us to tightly compress the shell. Furthermore, we show the ability to optimize the symmetry of the imploding shell by changing the hohlraum length, successfully tuning a suitable tube-shaped shell to compensate for the large angular spread of the relativistic electron beam and to enhance the electron-to-core coupling efficiency via resistive magnetic fields. Benefiting from those experimental techniques, a significant enhancement in neutron yield was achieved in our indirectly driven fast ignition experiments. These results pave the way towards high-coupling fast ignition experiments with indirectly driven targets similar to those at the National Ignition Facility.Experiments realizing the indirect-drive fast ignition scheme for inertial confinement fusion are reported. Enabled by a tightly compressed target, an increase of neutron yield is observed.
ABSTRACT
X-ray images of galaxy clusters often show disturbed structures that are indications of cluster mergers. To complement our previous work on the dynamical state of 964 clusters observed by ...Chandra, we process the X-ray images for 1308 clusters from XMM–Newton archival data, together with the images of 22 clusters newly released by Chandra, and we evaluate their dynamical state from these X-ray images. The concentration index c, the centroid shift ω and the power ratio P3/P0 are calculated in circular regions with a certain radius of 500 kpc, and the morphology index δ is estimated within elliptical regions that can be adapted to the cluster size and shape. In addition, the dynamical parameters for 42 clusters previously estimated from Chandra images are upgraded based on the newly available redshifts. Good consistence is found between dynamical parameters derived from XMM–Newton and Chandra images for the overlapped sample of clusters in the two data sets. The dependence of mass scaling relations on the dynamical state is shown by using the data of 388 clusters. All data and related software are available at http://zmtt.bao.ac.cn/galaxy_clusters/dyXimages/.
HUBS: Hot Universe Baryon Surveyor Cui, W.; Chen, L.-B.; Gao, B. ...
Journal of low temperature physics,
04/2020, Volume:
199, Issue:
1-2
Journal Article
Peer reviewed
Hot Universe Baryon Surveyor (HUBS) is proposed in China as a major X-ray mission for the next decade. It is designed to be highly focused scientifically, with two primary objectives: (1) detecting ...X-ray emission from hot baryons in intergalactic medium and circumgalactic medium (CGM), and characterizing their physical and chemical properties; (2) studying, based on the observations, the accretion and feedback processes that are thought to be highly relevant to the heating and chemical enrichment of the baryons in the CGM. Because of very low densities, the signal is expected to be very weak and thus technically difficult to detect. On the other hand, the spectrum of the emission is expected to be line rich, so it would be effective for detecting the hot baryons in bright emission lines. For that, an instrument with high spectral resolution, large effective area and large field of view (FoV) would be required. HUBS will couple a TES-based X-ray imaging spectrometer to a large FoV X-ray telescope to satisfy these requirements. A preliminary design of HUBS is presented.
ABSTRACT Diffuse radio emission in galaxy clusters is known to be related to cluster mass and cluster dynamical state. We collect the observed fluxes of radio halos, relics, and mini-halos for a ...sample of galaxy clusters from the literature, and calculate their radio powers. We then obtain the values of cluster mass or mass proxies from previous observations, and also obtain the various dynamical parameters of these galaxy clusters from optical and X-ray data. The radio powers of relics, halos, and mini-halos are correlated with the cluster masses or mass proxies, as found by previous authors, while the correlations concerning giant radio halos are in general the strongest. We found that the inclusion of dynamical parameters as the third dimension can significantly reduce the data scatter for the scaling relations, especially for radio halos. We therefore conclude that the substructures in X-ray images of galaxy clusters and the irregular distributions of optical brightness of member galaxies can be used to quantitatively characterize the shock waves and turbulence in the intracluster medium responsible for re-accelerating particles to generate the observed diffuse radio emission. The power of radio halos and relics is correlated with cluster mass proxies and dynamical parameters in the form of a fundamental plane.
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