The Wide Field-of-View Cherenkov Telescope Array (WFCTA) and the Water Cherenkov Detector Array (WCDA) of LHAASO are designed to work in combination for measuring the energy spectra of the cosmic ray ...species over a very wide energy range from a few TeV to 10 PeV. The energy calibration can be achieved with a proven technique of measuring the westward shift of the Moon shadow cast by galactic cosmic rays due to the geomagnetic field. This deflection angle Δ is inversely proportional to the cosmic ray rigidity. The precise measurement of the shifts by WCDA allows us to calibrate its energy scale for energies as high as 35 TeV. Through a set of commonly triggered events, the energy scales can be propagated to WFCTA. The energies of the events can be derived both by WCDA-1 and WFCTA with the median energies 23.4 ± 0.1 ± 1.3 TeV and ( 21.9 ± 0.1 TeV ), respectively, which are consistent within uncertainties. In addition, the propagation of the energy scale is also validated by the Moon shadow based on the same data selection criteria of the commonly triggered events. This paper reports, for the first time, an observational measurement of the absolute energy scale of the primary cosmic rays generating showers observed by air Cherenkov telescopes.
Pedicularis is the largest genus in the Orobanchaceae (>300) with many species co-occurring and co-blooming in subalpine to alpine meadows in the Himalayas. Although it is well known that different ...Pedicularis species place pollen on different parts of the same bumblebee's body, thus reducing interspecific pollen transfer, it is not known whether post-pollination components also contribute to reproductive isolation (RI). In this study, we quantified the individual strengths and absolute contributions of six pre- and post-pollination components of RI between three sympatric species in two pairs; Pedicularis gruina × Pedicularis tenuisecta (gru × ten) and Pedicularis comptoniifolia × Pedicularis tenuisecta (com × ten). All three Pedicularis species shared the same Bombus species. Individual foragers showed a high, but incomplete, floral constancy for each species. Therefore, pre-pollination barriers were potentially 'leaky' as Bombus species showed a low but consistent frequency of interspecific visitation. The RI strength of pre-pollination was lower in com × ten than in gru × ten. In contrast, post-pollination barriers completely blocked gene flow between both sets of species pairs. Two post-pollination recognition sites were identified. Late acting rejection of interspecific pollen tube growth occurred in com♀ × ten♂, while seeds produced in bi-directional crosses of gru × ten failed to germinate. We propose that, although floral isolation based on pollen placement on pollinators in the genus Pedicularis is crucial to avoid interspecific pollen transfer, the importance of this mode of interspecific isolation may be exaggerated. Post-pollination barriers may play even larger roles for currently established populations of co-blooming and sympatric species in this huge genus in the Himalayas.
The impact of impurity ions on a pedestal has been investigated in the HL-2A Tokamak, at the Southwestern Institute of Physics, Chengdu, China. Experimental results have clearly shown that during the ...H-mode phase, an electromagnetic turbulence was excited in the edge plasma region, where the impurity ions exhibited a peaked profile. It has been found that double impurity critical gradients are responsible for triggering the turbulence. Strong stiffness of the impurity profile has been observed during cyclic transitions between the I-phase and H-mode regime. The results suggest that the underlying physics of the self-regulated edge impurity profile offers the possibility for an active control of the pedestal dynamics via pedestal turbulence.
Polyamines play an important role in stress response. In the pathway of polyamines synthesis, S-adenosylmethionine decarboxylase (SAMDC) is one of the key enzymes. In this study, a full length cDNA ...of SAMDC (AhSAMDC) was isolated from peanut (Arachis hypogaea L.). Phylogenetic analysis revealed high sequence similarity between AhSAMDC and SAMDC from other plants.
In peanut seedlings exposed to sodium chloride (NaCl), the transcript level of AhSAMDC in roots was the highest at 24 h that decreased sharply at 72 and 96 h after 150 mM NaCl treatment. However, the expression of AhSAMDC in peanut leaves was significantly inhibited, and the transcript levels in leaves were not different compared with control
These results implied the tissue‐specific and time-specific expression of AhSAMDC. The physiological effects and functional mechanism of AhSAMDC were further evaluated by overexpressing AhSAMDC in tobaccos. The transgenic tobacco lines exhibited higher germination rate and longer root length under salt stress. Reduced membrane damage, higher antioxidant enzyme activity, and higher proline content were also observed in the transgenic tobacco seedlings. What's more, AhSAMDC also led to higher contents of spermidine and spermine, which can help to scavenge reactive oxygen species.
Together, this study suggests that AhSAMDC enhances plant resistance to salt stress by improving polyamine content and alleviating membrane damage
AhSAMDC subcloned into tobacco plants may play an important role in alleviating oxidative stress and membrane damages by improving antioxidant enzymes under salt stress.
In this study, we aimed to describe a classification method (position and displacement (PD) classification) and the corresponding treatment strategies for condylar fractures in children, based on the ...anatomical position and displacement of the fractures. Moreover, we aimed to explore the effect of the treatment strategies for condylar fractures in children. Such fractures were classified into the following three types by PD classification: condylar head fracture (type A), mildly displaced condylar neck and base fracture (type B), and severely displaced condylar neck and base fracture (type C). According to this classification, we proposed the corresponding treatment strategy of closed treatment for types A and B fractures and open treatment for type C fractures. Eighty-four patients who had 123 condylar fractures (type A = 97, type B = 16, type C = 10) were included in this study. Type A fractures showed the restoration of normal function with favourable remodelling in the condyles. Types B and C fractures had good function and symmetry in the condylar angle and height of the condylar neck. The PD classification and corresponding treatment strategies may serve as a better option for the clinical treatment of condylar fractures in children.
A novel austenite-martensite dual-phase steel with a ductility of ~30% and tensile strength over 1.4 GPa was developed. The hard martensite in the dual phase steel was strengthened through ...precipitation strengthening by Cu/NiAl precipitates, forming the maraging phase. The deformation mechanisms of the steel were investigated using in situ neutron diffraction and transmission electron microscopy (TEM). The results indicate that the maraging phase constrains the deformation of soft austenite, forming a strong skeleton frame with the soft austenite involved in the frame. The yield strength was controlled by the deformation of hard maraging phase, leading to the high strength of the steel. The plasticity of the maraging phase was improved through the synchronously deformation and rotation of martensite grains along with the frame-structure effect. During deformation of the maraging phase, the transfer of the dynamic stress and strain from the hard phase to a soft one compels the cooperative deformation of the soft phase together with the hard phase. This deformation contributes further to the ductility through the transformation-induced plasticity (TRIP) effects of the soft austenite. Furthermore, the cooperative deformation and the dynamic stress/strain partitions can effectively suppress the strain localization at the phase interface, retarding the crack initiation.
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•A frame-structured dual phase microstructure was developed.•Strengthened martensite forms skeleton frame with the soft austenite involved.•Hard phase with frame effect controls the yielding behavior of the steel.•The cooperative deformation and stress partitions suppress the strain localization.
In December 2019, novel coronavirus pneumonia epidemic occurred in Wuhan, Hubei Province, and spread rapidly across the country. In the early stages of the epidemic, China adopted the containment ...strategy and implemented a series of core measures around this strategic point, including social mobilization, strengthening case isolation and close contacts tracking management, blocking epidemic areas and traffic control to reduce personnel movements and increase social distance, environmental measures and personal protection, with a view to controlling the epidemic as soon as possible in limited areas such as Wuhan. This article summarizes the background, key points and core measures in the country and provinces. It sent prospects for future prevention and control strategies.
The moiré-pattern with slightly interlayer-twisted bilayer two-dimensional (2D) materials has recently been receiving substantial attention. One of the major characters for these intriguing ...structures is the appearance of low-energy ultra-flat bands and thus a package of new physics associated with strong electron correlation emerges. However, such new physics may become vague unless the twist-angle θ is sufficiently small such as θ ∼ 1°, making practical applications and control-flexibility hard to handle. In this work, we explore the possible flat-band moiré physics in recently concerned 2D bilayer α-In2Se3 which is antiferroelectric with sublayer out-of-plane (OP) polarizations, addressing the potential role of polarization-bound charges in modulation of electron–electron correlation and interlayer hybridization, based on the extensive first-principles calculations. On one hand, it is found that the low energy band becomes extremely flat in the bilayer α-In2Se3 moiré-pattern with relatively large twist-angle, e.g. θ = 13.17°, which is more easily accessible experimentally. On the other hand, the impact of the sublayer OP polarizations on the band structure is asymmetric, and the flattening effect is much more remarkable for the end-to-end polarization alignment but weaker for the head-to-head alignment. This work thus opens a broad roadmap for technological access to artificial fabrication of novel moiré-patterned 2D materials by means of low-dimensional ferroelectricity.
In this paper, we report on the discovery of an optical flare observed in the R band from the red-dwarf eclipsing binary CU Cancri, whose component stars are at the upper boundary of full convection ...(M
1= 0.43 M⊙ and M
2= 0.4 M⊙, where M⊙ is the solar mass). The amplitude of the flare is the largest among those detected in the R band (∼0.52 mag) and the duration time is about 73 min. Like flares observed on the Sun, quasi-periodic oscillations were seen during and after the flare. Three more R-band flares were found by follow-up monitoring. In total, this binary was monitored photometrically by using an R filter for 79.9 h, which has revealed an R-band flare rate of about 0.05 flares per hour. Together with other strong chromospheric and coronal activities (i.e. very strong Hα and Hβ emission features and an extreme ultraviolet and X-ray source), these detections indicate that it has very strong magnetic activity. Therefore, the apparent faintness (∼1.4 mag in the V band) of CU Cnc, compared with other single red dwarfs of the same mass, can be plausibly explained by the high coverage of dark spots.
Both miR-21 and miR-183 are upregulated in hepatocellular carcinoma (HCC) and are considered as oncomiR. However, their oncogenic roles are still not fully understood. This study aimed to explore the ...regulative role of miR-21 and miR-183 over suppressors of cytokine signaling 6 (SOCS6), a negative regulator of cytokine receptor signaling.
qRT-PCR analysis was performed to assess miR-21 and miR-183 expression in tumor tissues obtained from HCC patients and in HCC cell lines HepG2 and Hep3B. Their regulation over SOCS6 is verified using dual luciferase assay and Western blot analysis. The function of miR-21/miR-183-SOCS6 axis in cell growth, invasion and apoptosis was studied.
MiR-21 and miR-183 expression in HCC tissues than in adjacent normal tissues. Knockdown of miR-21 and miR-183 in HepG2 and Hep3B cells could decrease cell viability, increase cell apoptosis and decrease cell invasion. Based on the dual luciferase assay and Western blot analysis, we confirmed that both miR-21 and miR-183 can simultaneously target SOCS6 and modulate its expression at protein level. Overexpression of SOCS6 without 3'UTR could significantly lower cell growth rate and invasion capability, but increase relative caspase 3/7 activity and the ratio of apoptotic cells. However, these effects could not be blocked by miR-21 or miR-183 mimics.
This study revealed a novel miR-21/miR-183-SOCS6 axis that might play an important role in modulating cell growth and invasion of HCC cells.
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