High efficiency and collimated terahertz pulse from ultra-short intense laser and cone target.

We propose a new, to the best of our knowledge, method to radiate a high-efficiency and collimated terahertz (THz) pulse from a relativistic femtosecond laser and cone target. Particle-in-cell simulations demonstrate that a THz source of 40 mJ, pointing at an angle of ∼20 ∘, can be generated from a laser pulse of 1.9 J by using a cone target whose open angle is 10 ∘. The peak power of the THz pulse is 1011 W. This method, which manipulates the divergence angle and the energy conversion efficiency of the THz source, should promote THz science into the extra strong region with a compact laser system.

A versatile control program for positioning and shooting targets in laser-plasma experiments.

We introduce a LabVIEW-based control program that significantly improves the efficiency and flexibility in positioning and shooting solid targets in laser-plasma experiments. The hardware driven by this program incorporates a target positioning subsystem and an imaging subsystem, which enables us to install up to 400 targets for one experimental campaign and precisely adjust them in six freedom degrees. The overall architecture and the working modes of the control program are demonstrated in detail. In addition, we characterized the distributions of target positions of every target holder and simultaneously saved the target images, resulting in a large dataset that can be used to train machine learning models and develop image recognition algorithms. This versatile control system has become an indispensable platform when preparing and conducting laser-plasma experiments.

LncRNA FAM83A-AS1 aggravates the malignant development of esophageal cancer by binding to miR-495-3p.

OBJECTIVE: It is of significance to screen out differentially expressed long non-coding RNAs (lncRNAs) that can be utilized as tumor biomarkers in esophageal cancer. This study aims to uncover the effect of lncRNA FAM83A-AS1 on regulating migratory potential in esophageal cancer and the underlying mechanism. PATIENTS AND METHODS: Tumor tissues and adjacent normal ones were collected from 62 esophageal cancer patients for detecting FAM83A-AS1 levels. Correlations of FAM83A-AS1 with clinical indexes and overall survival of esophageal cancer patients were analyzed. Thereafter, regulatory effects of FAM83A-AS1 on migratory potential in OE19 and OE33 cells were examined by transwell and wound healing assay. Then, the target genes of FAM83A-AS1 were predicted and functionally analyzed, and a protein interaction network was constructed. Finally, the mechanism of FAM83A-AS1 in regulating the downstream gene miR-495-3p was analyzed through Luciferase assay and rescue experiments. RESULTS: It was found that FAM83A-AS1 was upregulated in esophageal cancer tissues and cell lines. Higher rates of lymphatic and distant metastasis and worse survival were observed in esophageal cancer patients expressing higher level of FAM83A-AS1. Besides, the knockdown of FAM83A-AS1 suppressed migratory potential in OE19 cells, while the overexpression of FAM83A-AS1 yielded the opposite trend in OE33 cells. Moreover, miR-495-3p was indicated to be the target gene binding FAM83A-AS1, and it was lowly expressed in esophageal cancer and negatively regulated by FAM83A-AS1. Furthermore, the overexpression of miR-495-3p partially abolished the regulatory effect of FAM83A-AS1 on migratory potential in esophageal cancer. CONCLUSIONS: FAM83A-AS1 is upregulated in esophageal cancer, and it stimulates migratory potential in esophageal cancer by negatively regulating miR-495-3p.

[Clinical analysis of 5 cases of dural arteriovenous fistulas complained of pulsatile tinnitus].

Objective: The clinical characteristics of dural arteriovenous fistula with pulsatile tinnitus were analyzed to deepen the understanding of the disease. Methods: The clinical data of five patients complained of pulsatile tinnitus and diagnosed dural arteriovenous fistula in Henan People's Hospital from May 2013 to June 2018 were retrospectively analyzed, including 3 males and 2 females, aged 27-65 years. Results: The main clinical symptoms of the five patients were continuous pulsatile tinnitus, accompanied/not accompanied by headache, memory decline, etc., with a course of three months to 20 years. They were diagnosed as dural arteriovenous fistula by digital subtraction angiography, and three cases of tinnitus disappeared and two cases of tinnitus were relieved after embolization. Conclusions: The dural arteriovenous fistula is a rare and complicated disease. When the patient complain of the pulsatile tinnitus, the related etiology should be considered and managed properly.

Detection and analysis of laser driven proton beams by calibrated Gafchromic HD-V2 and MD-V3 radiochromic films.

The radiochromic film (RCF) is a high-dose, high-dynamic range dosimetry detection medium. A stack of RCFs can be used to detect both spatial and energetic distribution of laser driven ion beams with a large divergence angle and continuous energy spectrum. Two types of RCFs (HD-V2 and MD-V3, from Radiation Products Design, Inc.) have been calibrated using MeV energy protons and carbon ions produced by using a 2 × 6 MV tandem electrostatic accelerator. The proportional relationship is obtained between the optical density and the irradiation dose. For protons, the responses are consistent at all energies with a variation of about 15%. For carbon ions, the responses are energy related, which should be noted for heavy ion detection. Based on the calibration, the broad energy spectrum and charge distribution of laser accelerated proton beam with energy from 3 to 8 MeV and pC charge were detected and reconstructed at the Compact LAser Plasma Accelerator at Peking University.

Autophagy attenuates the oxidative stress-induced apoptosis of Mc3T3-E1 osteoblasts.

OBJECTIVE: The oxidative stress-induced osteoblast apoptosis plays an important role in the pathological process of osteoporosis, but the roles of autophagy in oxidative stress and apoptosis of osteoblasts remain unclear. This study aimed to observe the role of autophagy in oxidative stress injury of osteoblasts and the relationship between autophagy and apoptosis. MATERIALS AND METHODS: Mc3T3-E1 cells were stimulated with different concentrations (0.1, 0.5, and 1 mM) of hydrogen peroxide. The cell viability was detected via cell counting kit 8 (CCK8) at different time points (0, 2, 6, 8, and 12 h), the apoptosis was detected via Western blotting and flow cytometry, and the autophagy was detected via macrophage-derived chemokine (MDC) and transmission electron microscope. The changes in expression of autophagy-associated protein, Beclin1, and LC3II/I ratio, were detected via Western blotting. Moreover, the intracellular reactive oxygen species (ROS) level and extracellular superoxide dismutase (SOD) level were observed using the autophagy regulators, rapamycin (Rap) and 3-methyladenine (3-MA), so as to clarify the interaction between autophagy and cellular oxidation. RESULTS: Hydrogen peroxide-induced apoptosis and autophagy of osteoblasts were in dose- and time-dependent manners; the hydrogen peroxide inhibitors could inhibit the autophagy level, and autophagy inhibitor (3-MA) could significantly enhance the hydrogen peroxide-induced ROS level and apoptosis rate in cells. Besides, Western blotting confirmed that the cleaved caspase-3 and cleaved poly adenosine diphosphate ribose polymerase (PARP) proteins were increased. The autophagy inducer (Rap) partially inhibited the hydrogen peroxide-induced oxidative stress and apoptosis. CONCLUSIONS: Autophagy inhibits the oxidative stress-mediated apoptosis of osteoblasts, which is a potential target for the osteoporosis treatment.

[Meiosis-like reduction in the culture system for somatic embryogenesis of Arabidopsis thaliana].

The somatic meiosis-like reduction was observed in some cells in the embryogenic calli of Arabidopsis thaliana. One type was somatic chromosome reductional grouping, in which the chromosomes in a cell either separated into two groups, or separated into more than two groups at prophase or metaphase. The chromosomes separated directly, the morphology of the chromosomes did not show any role of the spindle fibers. Chromosome reductional grouping happened more frequently in polyploid cells. The other type was somatic meiossi which was analogous to that existed in the process of gametogenesis, and characterized by the pairing and synapsis of homologues chromosomes. In the embryogenic calli cultured on dedifferentiation medium, about 3% of the observed cells contained haploid number of chromosomes, while the tetrad cells occurred at a frequency of about 4%. The somatic meiosis-like reduction could result in the recombination of chromosomes in the cells generated by these processes. The roles of somatic meiosis-like reduction in the somatic embryogenesis and somaclonal variations were discussed.

Effect of MWCNTs on Gastric Emptying in Mice.

After making model of gastric functional disorder (FD), part of model mice were injected intravenously (i.v.) with oxide multi-walled carbon nanotubes (oMWCNTs) to investigate effect of carbon nanotubes on gastric emptying. The results showed that NO content in stomach, compared with model group, was decreased significantly and close to normal level post-injection with oMWCNTs (500 and 800 µg/mouse). In contrast to FD or normal groups, the content of acetylcholine (Ach) in stomach was increased obviously in injection group with 500 or 800 µg/mouse of oMWCNTs. The kinetic curve of emptying was fitted to calculate gastric motility factor k; the results showed that the k of injection group was much higher than FD and normal. In other words, the gastric motility of FD mice was enhanced via injection with oMWCNTs. In certain dosage, oMWCNTs could improve gastric emptying and motility.