Abstract: As a major component in the air, nitrogen emits fluorescence when it interacts with intensive laser field. The fluorescence comes from the first negative band system (〈inline-formula〉〈tex-math id="M7"〉\begin{document}${{\rm{B}}^{{2}}}\Sigma _{\rm{u}}^{{ + }} \to {{\rm{X}}^{{2}}}\Sigma _{\rm{g}}^{{ + }}$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M7.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M7.png"/〉〈/alternatives〉〈/inline-formula〉 transition) of 〈inline-formula〉〈tex-math id="M8"〉\begin{document}${\rm{N}}_{{2}}^{{ + }}$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M8.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M8.png"/〉〈/alternatives〉〈/inline-formula〉 and the second positive band system (〈inline-formula〉〈tex-math id="M9"〉\begin{document}${{\rm{C}}^{{3}}}\Pi _{\rm{u}}^{{ + }} \to {{\rm{B}}^{{3}}}\Pi _{\rm{g}}^{{ + }}$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M9.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M9.png"/〉〈/alternatives〉〈/inline-formula〉 transition) of 〈inline-formula〉〈tex-math id="M10"〉\begin{document}${{\rm{N}}_{{2}}}$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M10.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M10.png"/〉〈/alternatives〉〈/inline-formula〉. Under the action of high-intensity femtosecond laser, 〈inline-formula〉〈tex-math id="M11"〉\begin{document}${{\rm{N}}_{{2}}}$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M11.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M11.png"/〉〈/alternatives〉〈/inline-formula〉 can be directly photo-ionized into 〈inline-formula〉〈tex-math id="M12"〉\begin{document}${\rm{N}}_{{2}}^{{ + }}{{(}}{{\rm{B}}^{{2}}}\Sigma _{\rm{u}}^{{ + }})$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M12.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M12.png"/〉〈/alternatives〉〈/inline-formula〉, which results in fluorescence emission of 〈inline-formula〉〈tex-math id="M13"〉\begin{document}${\rm{N}}_{{2}}^{{ + }}$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M13.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M13.png"/〉〈/alternatives〉〈/inline-formula〉. In the process of femtosecond laser filament formation, the dynamic processes such as ionization and excitation of nitrogen molecules are affected by the laser intensity distribution and laser polarization direction. The products show different distributions in the propagation direction and radial space, which, in turn, affects its light emission. Therefore, it is necessary to further ascertain its generation mechanism through the spatial distribution of nitrogen fluorescence. In this experiment, the spatial distribution of the nitrogen fluorescence emission generated by linearly polarized femtosecond laser pulse filaments in air is measured. By changing the polarization direction of the laser to study the distribution of nitrogen fluorescence in the radial plane, it is found that the fluorescence emission of 〈inline-formula〉〈tex-math id="M14"〉\begin{document}${\rm{N}}_2^ + $\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M14.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M14.png"/〉〈/alternatives〉〈/inline-formula〉 is more intense in the direction perpendicular to the laser polarization, while it is weaker in the direction parallel to the laser polarization. The nitrogen fluorescence emission has the same intensity in all directions. The ionization probability of a linear molecule depends on the angle between the laser polarization direction and the molecular axis, which is maximum (minimum) when the angle is 〈inline-formula〉〈tex-math id="M15"〉\begin{document}${{{0}}^{\rm{o}}}$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M15.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M15.png"/〉〈/alternatives〉〈/inline-formula〉(〈inline-formula〉〈tex-math id="M16"〉\begin{document}${{9}}{{{0}}^{\rm{o}}}$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M16.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M16.png"/〉〈/alternatives〉〈/inline-formula〉). The 〈inline-formula〉〈tex-math id="M17"〉\begin{document}${{\rm{N}}_{{2}}}$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M17.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M17.png"/〉〈/alternatives〉〈/inline-formula〉 gas is more likely to be ionized in the laser polarization direction, the nitrogen molecular ions 〈inline-formula〉〈tex-math id="M18"〉\begin{document}${\rm{N}}_{{2}}^{{ + }}$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M18.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M18.png"/〉〈/alternatives〉〈/inline-formula〉 and electrons are separated in the direction parallel to the laser polarization. Therefore, more ions (〈inline-formula〉〈tex-math id="M19"〉\begin{document}${\rm{N}}_{{2}}^{{ + }}$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M19.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M19.png"/〉〈/alternatives〉〈/inline-formula〉) are generated in the direction parallel to the laser polarization, and the fluorescence emission of 〈inline-formula〉〈tex-math id="M20"〉\begin{document}${\rm{N}}_{{2}}^{{ + }}$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M20.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M20.png"/〉〈/alternatives〉〈/inline-formula〉 is more intense. Along the propagation direction of the laser, it is found that the fluorescence of 〈inline-formula〉〈tex-math id="M21"〉\begin{document}${{\rm{N}}_{{2}}}$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M21.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M21.png"/〉〈/alternatives〉〈/inline-formula〉 appears before the fluorescence of 〈inline-formula〉〈tex-math id="M22"〉\begin{document}${\rm{N}}_2^ + $\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M22.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M22.png"/〉〈/alternatives〉〈/inline-formula〉 and disappears after the fluorescence of 〈inline-formula〉〈tex-math id="M23"〉\begin{document}${\rm{N}}_{{2}}^{{ + }}$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M23.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M23.png"/〉〈/alternatives〉〈/inline-formula〉 has vanished. This is due to the fact that 〈inline-formula〉〈tex-math id="M24"〉\begin{document}${{\rm{N}}_{{2}}}$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M24.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M24.png"/〉〈/alternatives〉〈/inline-formula〉 can be ionized into 〈inline-formula〉〈tex-math id="M25"〉\begin{document}${\rm{N}}_{{2}}^{{ + }}{{(}}{{\rm{B}}^{{2}}}\Sigma_{\rm{u}}^{{ + }})$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M25.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M25.png"/〉〈/alternatives〉〈/inline-formula〉 at the position of high enough laser intensity, thus emitting fluorescence of 〈inline-formula〉〈tex-math id="M26"〉\begin{document}${\rm{N}}_2^ + $\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M26.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M26.png"/〉〈/alternatives〉〈/inline-formula〉. However, the laser energy is not enough to ionize nitrogen at the beginning and end of laser transmission, but it can generate 〈inline-formula〉〈tex-math id="M27"〉\begin{document}${\rm{N}}_2^ * $\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M27.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M27.png"/〉〈/alternatives〉〈/inline-formula〉, which emits nitrogen fluorescence through the process of intersystem crossing 〈inline-formula〉〈tex-math id="M28"〉\begin{document}${\rm{N}}_2^*\xrightarrow{{{\rm{ISC}}}}{{\rm{N}}_2}({{\rm{C}}^3}\Pi _{\rm{u}}^ + )$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M28.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M28.png"/〉〈/alternatives〉〈/inline-formula〉. The spatial distribution of nitrogen fluorescence emission during femtosecond laser filament formation shows that in the case of short focal length, the intersystem crossing scheme can explain the formation of 〈inline-formula〉〈tex-math id="M29"〉\begin{document}${{\rm{N}}_{{2}}}{{(}}{{\rm{C}}^{{3}}}\Pi _{\rm{u}}^{{ + }})$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M29.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20201704_M29.png"/〉〈/alternatives〉〈/inline-formula〉. This research is helpful in understanding the mechanism of nitrogen fluorescence emission.

Abstract: Arterial medial calcification is a common disease in patients with type 2 diabetes, end-stage renal disease and hypertension, resulting in high incidence and mortality of cardiovascular event. H19 has been demonstrated to be involved in cardiovascular diseases like aortic valve diseases. However, role of H19 in arterial medial calcification remains largely unknown. We identified that H19 was upregulated in ß -glycerophosphate ( β -GP) induced vascular smooth muscle cells (VSMCs), a cellular calcification model in vitro . Overexpression of H19 potentiated while knockdown of H19 inhibited osteogenic differentiation of VSMCs, as demonstrated by changes of osteogenic genes Runx2 and ALP as well as ALP activity. Notably, H19 interacted with miR-140-5p directly, as demonstrated by luciferase report system and RIP analysis. Mechanistically, miR-140-5p attenuated osteoblastic differentiation of VSMCs by targeting Satb2 and overexpression of miR-140-5p blocked H19 induced elevation of Satb2 as well as the promotion of osteoblastic differentiation of VSMCs. Interestingly, over-expression of Satb2 induced phosphorylation of ERK1/2 and p38MAPK. In conclusion, H19 promotes VSMC calcification by acting as competing endogenous RNA of miR-140-5p and at least partially by activating Satb2-induced ERK1/2 and p38MAPK signaling.

Abstract: Bucket teeth of electric excavator used in metal mine bear severe impact and friction, so their life is short and this have an negative effect on productivity. The paper analyzes the case of failure and material of bucket teeth, and researches into the mechanism of abrasion of bucket teeth and distinguishing feature of the work hardening of ZGMn13, and draw the conclusion that it is correct to choose ZGMn13 as material of bucket teeth used in metal mine. Improve configuration of bucket teeth or enhance the abrasion resistance can prolong the service life.

Abstract: This study aimed to discover the novel noninvasive biomarkers for the diagnosis of pulmonary tuberculosis (TB). We applied iTRAQ 2D LC‐MS/MS technique to investigate protein profiles in patients with pulmonary TB and other lung diseases. A total of 34 differentially expressed proteins (24 upregulated proteins and ten downregulated proteins) were identified in the serum of pulmonary TB patients. Significant differences in protein S100‐A9 (S100A9), extracellular superoxide dismutase [Cu‐Zn] (SOD3), and matrix metalloproteinase 9 (MMP9) were found between pulmonary TB and other lung diseases by ELISA. Correlations analysis revealed that the serum concentration of MMP9 in the pulmonary TB was in moderate correlation with SOD3 ( r = 0.581) and S100A9 ( r = 0.471), while SOD3 was in weak correlation with S100A9 ( r = 0.287). The combination of serum S100A9, SOD3, and MMP9 levels could achieve 92.5% sensitivity and 95% specificity to discriminate between pulmonary TB and healthy controls, 90% sensitivity and 87.5% specificity to discriminate between pulmonary TB and pneumonia, and 85% sensitivity and 92.5% specificity to discriminate between pulmonary TB and lung cancer, respectively. The results showed that S100A9, SOD3, and MMP9 may be potential diagnostic biomarkers for pulmonary TB, and provided experimental basis for the diagnosis of pulmonary TB.

Abstract: This paper presents the molecular dynamics simulations of atomic structures of nanocrystals (1—3nm).The X-ray diffraction patterns and the radial distribution functions corresponding to the above nanocrystalline structures were also computed.The results show that the interfacial component exhibits short-range order,and the distortion in crystalline component increases with the decrease of grain size.