On Zero Frequency Zonal Flow and Second Harmonic Generation by Finite Amplitude Energetic Particle Induced Geodesic Acoustic Mode

Nonlinear self-interaction of finite amplitude energetic particle induced geodesic acoustic mode (EGAM) is investigated using nonlinear gyrokinetic theory. It is found that both zero frequency zonal flow(ZFZF) and second harmonic can be driven by finite amplitude EGAM, with energetic particles (EPs) playing a dominant role in the nonlinear couplings through finite orbit width effects. For ZFZF, the effects of EPs on EGAM nonlinear self-coupling dominate that of the thermal plasmas which are also present; while the second harmonic generation is only possible via finite amplitude coupling though EPs. Our findings may improve the understanding of stabilizing zonal modes, and consequently, drift wave turbulence

CRISPR-Cas13a system: A novel tool for molecular diagnostics

The clustered regularly interspaced short palindromic repeats (CRISPR) system is a natural adaptive immune system of prokaryotes. The CRISPR-Cas system is currently divided into two classes and six types: types I, III, and IV in class 1 systems and types II, V, and VI in class 2 systems. Among the CRISPR-Cas type VI systems, the CRISPR/Cas13a system has been the most widely characterized for its application in molecular diagnostics, gene therapy, gene editing, and RNA imaging. Moreover, because of the trans-cleavage activity of Cas13a and the high specificity of its CRISPR RNA, the CRISPR/Cas13a system has enormous potential in the field of molecular diagnostics. Herein, we summarize the applications of the CRISPR/Cas13a system in the detection of pathogens, including viruses, bacteria, parasites, chlamydia, and fungus; biomarkers, such as microRNAs, lncRNAs, and circRNAs; and some non-nucleic acid targets, including proteins, ions, and methyl groups. Meanwhile, we highlight the working principles of some novel Cas13a-based detection methods, including the Specific High-Sensitivity Enzymatic Reporter UnLOCKing (SHERLOCK) and its improved versions, Cas13a-based nucleic acid amplification-free biosensors, and Cas13a-based biosensors for non-nucleic acid target detection. Finally, we focus on some issues that need to be solved and the development prospects of the CRISPR/Cas13a system

Development of 146nm Vacuum UV Light Source

AbstractThe principle of dielectric-barrier discharge (DBD) producing 146nm vacuum ultraviolet (VUV) light is introduced in this article. MgF2 and Kr are used as the output window and the discharge gas, respectively, in the VUV light source. Fairly wide, narrow-bandwidth UV light could be generated with peak wavelength of 146nm and a full width at half maxima of 12nm. In addition, the impact of air pressure, voltage amplitude and frequency to the light source is also analyzed

X-ray radiation and runaway electron beams generated during discharges in atmospheric-pressure air at rise times of voltage pulse of 500 and 50 ns

The parameters of X-ray radiation and runaway electron beams (RAEBs) generated at long-pulse discharges in atmospheric-pressure air were investigated. In the experiments, high-voltage pulses with the rise times of 500 and 50 ns were applied to an interelectrode gap. The gap geometry provided non-uniform distribution of the electric field strength. It was founded that at the voltage pulse rise time of 500 ns and the maximum breakdown voltage Um for 1 cm-length gap, a duration [full width at half maximum (FWHM)] of a RAEB current pulse shrinks to 0.1 ns. A decrease in the breakdown voltage under conditions of a diffuse dischargeleads to an increase in the FWHM duration of the electron beam current pulse up to several nanoseconds. It was shown that when the rise time of the voltage pulse is of 500 ns and thediffuse discharge occurs in the gap, the FWHM duration of the X-ray radiation pulse canreach≈100 ns. It was established that at a pulse-periodic diffuse discharge fed by high-voltage pulses with the rise time of 50 ns, an energy of X-ray quanta and their number increase with increasing breakdown voltage. Wherein the parameter Um/pd is saved

Analysis of apparent resistivity change during waterproof coal pillar seepage based on finite element method

Waterproof coal pillar infiltration water makes water conduction channel formed in the coal pillar and may lead to the occurrence of underground water accident. The monitoring of seepage water in waterproof coal pillars is a necessary means to prevent and control the destabilization of waterproof coal pillars. This paper establishes a coupled model of seepage field and resistivity of water-bearing coal column, analyzes the changes of seepage field and pore water pressure of water- bearing coal column, and combines the inversion technique of direct current method to determine the apparent resistivity changes of seepage process. The following main conclusions are obtained in this paper: high-pressure water intrusion in the waterproof coal column aquifer is the essential cause of waterproof coal column seepage, and the inhomogeneous fissure network inside the coal body provides the necessary channel for high-pressure water circulation; staggered pore water areas are more favorable for pore water circulation compared with parallel pores, and the pore network area has a larger range of water pressures; the results of multiple inversions are obvious for the inversion of high-resistivity areas and low-resistivity areas. The low-resistance area of the apparent resistivity field corresponds well with the high water pressure area of the seepage field in space; there exists an obvious demarcation line between the low-resistance and high-resistance areas of the apparent resistivity, and the demarcation line is the demarcation line of the dangerous area of seepage when comparing with the area of the gradient change of the water pressure of the seepage field. The closer the visual resistivity inversion is to the roadway, the better the inversion effect is, and the higher the accuracy of the test results; the seepage water pressure at different depths shows a strong negative correlation with the visual resistivity, and the correlation reaches more than -0.8, and the DC method has a better detection effect for the seepage process of watertight coal pillars. This study provides a theoretical basis for the detection of seepage in waterproof coal pillars by DC electric method

The expression and role of protein kinase C (PKC) epsilon in clear cell renal cell carcinoma

Protein kinase C epsilon (PKCε), an oncogene overexpressed in several human cancers, is involved in cell proliferation, migration, invasion, and survival. However, its roles in clear cell renal cell carcinoma (RCC) are unclear. This study aimed to investigate the functions of PKCε in RCC, especially in clear cell RCC, to determine the possibility of using it as a therapeutic target. By immunohistochemistry, we found that the expression of PKCε was up-regulated in RCCs and was associated with tumor Fuhrman grade and T stage in clear cell RCCs. Clone formation, wound healing, and Borden assays showed that down-regulating PKCε by RNA interference resulted in inhibition of the growth, migration, and invasion of clear cell RCC cell line 769P and, more importantly, sensitized cells to chemotherapeutic drugs as indicated by enhanced activity of caspase-3 in PKCε siRNA-transfected cells. These results indicate that the overexpression of PKCε is associated with an aggressive phenotype of clear cell RCC and may be a potential therapeutic target for this disease