The effect of the incorporation of fluoride into strontium containing bioactive glasses

Recently, the porous bioactive glasses have attracted a lot of attention for use as scaffolds for tissue engineering bone; such glasses include the high phosphate, strontium containing glass (Stronbone P). However, the previous studies suggest that strontium can have a detrimental effect on the ability of apatite-like phase formation of the glass. The previously studied high phosphate all Sr glass showed an unidentified phase rather than an apatite-like phase upon immersion. Octa-calcium phosphate (OCP) is believed to be a precursor phase to apatite, however octa-strontium phosphate does not exist. Fluoride is known to knock out the OCP formation and promotes fluorapatite formation. This work presents the incorporation of a small amount of fluoride into calcium/strontium bioactive glasses. Differential scanning calorimetry was used to estimate the glass thermal properties. All of the studied glass compositions were subjected to bioactivity studies in Tris buffer (pH = 7.4) for up to 21 days. The initial glasses and the resultant precipitates were analysed using Fourier transform infrared spectroscopy, X-ray diffraction and magic angle spinning-nuclear magnetic resonance. The findings showed that all the fluoride containing glasses were amorphous and there was a marked increase in the rate of apatite formation in vitro compared to the equivalent fluoride free glasses, particularly for the all strontium containing glass. This indicates that the presence of fluoride affects the pathway of apatite formation, forming fluorapatite directly instead of via the transformation from OCP to hydroxyapatite. Therefore, fluoride may have potential future clinical applications as an additive to increase apatite formation

Stimulation of hepatocarcinogenesis by neutrophils upon induction of oncogenic kras expression in transgenic zebrafish

Background & AimsChronic inflammation is a major etiological factor for hepatocellular carcinoma (HCC), but how immune cells respond in the initiation of hepatocarcinogenesis remains uncharacterized. This study aims to investigate the response and roles of neutrophils in early hepatocarcinogenesis.MethodsBy inducible expression of oncogenic krasV12 in hepatocytes in transgenic zebrafish combined with live imaging of neutrophils in transparent larvae, the response of neutrophils to oncogenic liver was characterized and their roles investigated by pharmaceutical and genetic manipulations.ResultsWe found a rapid recruitment of neutrophils to the liver upon induction of krasV12 expression. Pharmaceutical stimulation of neutrophils resulted in further increases of neutrophils in oncogenic livers, liver size and tumor severity, while inhibition of neutrophils caused decreases of liver-associated neutrophils and liver size. Time-lapse video indicated that neutrophils had a stagnant migratory pattern meandering along the tumor edge but became relatively stationary upon entering the krasV12-expressing liver. Both oncogenic hepatocytes and tumor-associated neutrophils (TANs) were isolated via fluorescence-activated cell sorting. Molecular analyses indicated a pro-inflammatory microenvironment, as marked by increased tgfβ1a expression in krasV12-expressing hepatocytes and a loss of anti-tumor activities in TANs. Depletion of Tgf-β significantly reduced the number of TANs and the size of oncogenic liver.ConclusionsAn inflammatory cue from oncogenic hepatocytes upon induction of krasV12 expression causes a rapid recruitment of neutrophils to oncogenic liver and the neutrophils play a promoting role in early hepatocarcinogenesis

Insight-HXMT observations of Swift J0243.6+6124 during its 2017-2018 outburst

The recently discovered neutron star transient Swift J0243.6+6124 has been monitored by {\it the Hard X-ray Modulation Telescope} ({\it Insight-\rm HXMT). Based on the obtained data, we investigate the broadband spectrum of the source throughout the outburst. We estimate the broadband flux of the source and search for possible cyclotron line in the broadband spectrum. No evidence of line-like features is, however, found up to $\rm 150~keV$. In the absence of any cyclotron line in its energy spectrum, we estimate the magnetic field of the source based on the observed spin evolution of the neutron star by applying two accretion torque models. In both cases, we get consistent results with $B\rm \sim 10^{13}~G$, $D\rm \sim 6~kpc$ and peak luminosity of $\rm >10^{39}~erg~s^{-1}$ which makes the source the first Galactic ultraluminous X-ray source hosting a neutron star.Comment: publishe

Overview to the Hard X-ray Modulation Telescope (Insight-HXMT) Satellite

As China's first X-ray astronomical satellite, the Hard X-ray Modulation Telescope (HXMT), which was dubbed as Insight-HXMT after the launch on June 15, 2017, is a wide-band (1-250 keV) slat-collimator-based X-ray astronomy satellite with the capability of all-sky monitoring in 0.2-3 MeV. It was designed to perform pointing, scanning and gamma-ray burst (GRB) observations and, based on the Direct Demodulation Method (DDM), the image of the scanned sky region can be reconstructed. Here we give an overview of the mission and its progresses, including payload, core sciences, ground calibration/facility, ground segment, data archive, software, in-orbit performance, calibration, background model, observations and some preliminary results.Comment: 29 pages, 40 figures, 6 tables, to appear in Sci. China-Phys. Mech. Astron. arXiv admin note: text overlap with arXiv:1910.0443

FUNCTIONAL AND TRANSCRIPTOMIC STUDY OF NEUTROPHILS IN EARLY HEPATOCARCINOGENESIS IN KRASG12V TRANSGENIC ZEBRAFISH MODEL

Ph.DDOCTOR OF PHILOSOPH

Research on key technologies of intelligent gangue sorting robot

This paper introduces the application and research status of the intelligent gangue sorting robot. This paper points out that the intelligent gangue sorting robot is mainly based on the principle of X-ray and image identification. And the high-pressure pneumatic sorting and truss robot grasping sorting are used to separate coal and gangue. The sorting actuators are mainly truss type, parallel type and series type of intelligent gangue sorting robot. The sorting actuators have fast response speed and often separate the gangue in the form of 'pulling' and 'grasping'. In the process of belt transportation, the compatibility of different gangue sizes and the optimization of movement path need to be considered in the 'pulling' of the intelligent gangue sorting robot. And the working space of the manipulator and the bearing capacity of the robot need to be considered in the 'grasping'. This paper analyzes the key technologies such as deep learning-based coal and gangue identification, unstructured multi-constraint environment-oriented motion planning of gangue sorting manipulator, force feedback-based active compliance control of manipulator and multi-arm cooperative sorting task allocation strategy and control. These technologies are used for intelligent gangue sorting robot to effectively realize gangue sorting in complex on-site environment. This paper points out that coal and gangue identification technology based on deep learning is one of the key technologies of gangue sorting robot. It still needs further research on the efficient construction method of coal gangue data set, improving the generalization of coal gangue identification algorithm, and the real-time optimization of coal gangue identification algorithm. Combined with the demand of field application and intelligent robot development, the future research directions of intelligent gangue sorting robot are pointed out. In the complex environment on site, it is suggested to improve the robustness and adaptability of the coal gangue identification algorithm. It is suggested to develop intelligent sensing and control technology for complex environment and high-precision three-dimensional pose estimation technology for gangue. It is suggested to develop intelligent gangue picking technology of gangue picking robot based on force position hybrid control. It is suggested to research intelligent gangue sorting robot underground gangue sorting technology