High-power cylindrical vector beam fiber laser based on an all-polarization-maintaining structure.

We propose and demonstrate an all-polarization-maintaining (PM) high-power cylindrical vector beam (CVB) fiber laser based on the principle of mode superposition. The non-degenerated LPy 11a is generated from the oscillator with the maximum power of 11.9W, whose slope efficiency is 24.4%. Then the stable single TE01 vector beam is achieved by the superposition of LPy 11a and LPx 11b in an all-PM architecture, its output power is 3.1W and mode purity of 91.2%. Due to the all-PM architecture, our configuration is free of adjusting polarization controller (PC) and reliable during long-term operation. This laser could be used as a high-power CVBs source for a wide range of applications towards scientific research and industrial field.

All-fiber bidirectional mode-locked laser to generate cylindrical vector beam asynchronous noise-like pulses.

We proposed and demonstrated a bidirectional mode-locked fiber laser to generate cylindrical vector beam (CVB) asynchronous pulses based on a graded index multimode fiber. A homemade fused taper two-mode fiber optical coupler (TMF-OC) is employed as a mode converter. The central wavelength for clockwise (CW) pulses can be tuned from 1030.32 nm to 1041.04 nm due to the filtering effect based on multimode interference, that of counterclockwise (CCW) pulses is from 1030.81 nm to 1039.28 nm. When the central wavelengths are 1033.22 nm and 1032.71 nm for CW direction and CCW direction respectively, CVB asynchronous noise-like pulses with a repetition rate difference of ∼436.9 Hz can be obtained. The purity of CVB in CW direction and CCW direction is 95.7% and 93.4% respectively. This bidirectional mode-locked fiber laser with CVB output can be better applied to laser gyroscopes, asynchronous sampling, and dual-comb technique, and impel the interdisciplinary studies in the future.

Generation of cylindrical vector beams in a linear cavity mode-locked fiber laser based on nonlinear multimode interference.

In this paper, a linear cavity mode-locked pulsed fiber laser generating cylindrical vector beams (CVBs) is proposed and demonstrated based on a nonlinear multimode interference. A homemade long-period fiber grating with a broad bandwidth of 121 nm is used as a mode converter inside the cavity. The saturable absorber was formed by single-mode fiber-graded index multimode fiber-single mode fiber (SMF-GIMF-SMF) structure. By controlling the pump power, the operation states are switchable among continuous-wave, Q-switched mode-locked (QML), and mode-locked regimes. The repetition rate of the QML CVB pulse envelope varies from 57.4 kHz to 102.7 kHz at the pump range of 118 to 285 mW. When increasing pump power to 380 mW, mode-locked CVB pulse repetition rate of 3.592 MHz, and pulse duration of 4.62 ns are achieved. In addition, the maximum single-pulse envelope energy can reach 510 nJ, and 142 mW average-power CVBs with a slope efficiency of as high as 20.2% can be obtained. Moreover, azimuthally and radially polarized beams can be obtained with mode purity over 95% in different operating regimes. The proposed fiber laser has a simple structure, and the operation is controllable in both temporal and spatial domains, which presents a flexible pulsed CVB source for application of laser processing, time or mode division multiplexing system, and spatiotemporal nonlinear optics.

High-efficiency mode-locked fiber laser with a switchable oscillating transverse mode in an all few-mode fiber linear cavity.

In this paper, an oscillating transverse mode switchable mode-locked fiber laser with a few-mode fiber linear cavity is proposed and demonstrated. An artificial filter is used to realize the mode gain modulation of the laser. The stable mode-locked pulsed operation with switchable wavelength is easily achieved and the oscillating transverse mode can be flexibly switched between the fundamental mode and high-order mode by adjusting the polarization controller. The mode-locked fiber laser directly oscillates in the high-order mode stably with a slope efficiency of as high as 12%, and the corresponding operating wavelength, repetition rate as well as pulse duration are 1054.07 nm, 22.662 MHz, 31.5 ps, respectively. Besides, a cylindrical vector beam with a high mode purity of 98.6% is obtained by removing the degeneracy of the LP11 mode. This compact and high-efficiency mode-locked fiber laser operating in switchable transverse mode has the potential application for laser processing, particle trapping, bioimaging, and mode division multiplexing system.

Manipulation of Skyrmion Motion Dynamics for Logical Device Application Mediated by Inhomogeneous Magnetic Anisotropy.

Magnetic skyrmions are promising potential information carriers for future spintronic devices owing to their nanoscale size, non-volatility and high mobility. In this work, we demonstrate the controlled manipulation of skyrmion motion and its implementation in a new concept of racetrack logical device by introducing an inhomogeneous perpendicular magnetic anisotropy (PMA) via micromagnetic simulation. Here, the inhomogeneous PMA can be introduced by a capping nano-island that serves as a tunable potential barriers/well which can effectively modulate the size and shape of isolated skyrmion. Using the inhomogeneous PMA in skyrmion-based racetrack enables the manipulation of skyrmion motion behaviors, for instance, blocking, trapping or allowing passing the injected skyrmion. In addition, the skyrmion trapping operation can be further exploited in developing special designed racetrack devices with logic AND and NOT, wherein a set of logic AND operations can be realized via skyrmion-skyrmion repulsion between two skyrmions. These results indicate an effective method for tailoring the skyrmion structures and motion behaviors by using inhomogeneous PMA, which further provide a new pathway to all-electric skyrmion-based memory and logic devices.

LncRNA ASAP1-IT1 enhances cancer cell stemness via regulating miR-509-3p/YAP1 axis in NSCLC.

BACKGROUND: Non-small cell lung cancer (NSCLC) is a major cause of cancer-related death worldwide, and cancer stem cell is responsible for the poor clinical outcome of NSCLC. Previous reports indicated that long noncoding RNAs (lncRNAs) play important roles in maintaining cancer stemness, however, the underlying mechanisms remain unclear. This study investigates the role of ASAP1 Intronic Transcript 1 (ASAP1-IT1) in cancer cell stemness of NSCLC. METHODS: The expression of ASAP1-IT1, microRNA-509-3p (miR-509-3p) and apoptosis-/stemness-related genes was analyzed by qRT-PCR in NSCLC tissues, cancer cells and spheres of cancer stem cells. Knockdown of ASAP1-IT1 or overexpression of miR-509-3p in NSCLC cells by infection or transfection of respective plasmids. Sphere formation and colony formation were used to detect NSCLC stem cell-like properties and tumor growth in vitro. Luciferase reporter assays, RNA immunoprecitation (RIP) and qRT-PCR assays were used to analyze the interaction between lncRNA and miRNA. The expression of expression of regulated genes of ASAP1-IT1/miR-509-3p axis was evaluated by qRT-PCR and Western blot. The NSCLC xenograft mouse model was used to validate the role of ASAP1-IT1 in NSCLC stemness and tumor growth in vivo. RESULTS: ASAP1-IT1 was up-regulated in NSCLC tissues, cancer cells, and in spheres of A549-derived cancer stem cells. Downregulation of ASAP1-IT1 or overexpression of miR-509-3p significantly decreased cell colony formation and stem cell-like properties of A549-dereived stem cells with decreased expression of stem cell biomarkers SOX2, CD34, and CD133, and suppressing the expression of cell growth-related genes, Cyclin A1, Cyclin B1, and PCNA. Furthermore, knockdown of ASAP1-IT1 or overexpression of miR-509-3p repressed tumor growth in nude mice via reducing expression of tumorigenic genes. ASAP1-IT1 was found to interact with miR-509-3p. Moreover, overexpression of ASAP1-IT1 blocked the inhibition by miR-509-3p on stem cell-like properties and cell growth of A549-dereived stem cells both in vitro and in vivo. Finally, the level of YAP1 was regulated by ASAP1-IT1 and miR-509-3p. CONCLUSIONS: YAP1-involved ASAP1-IT1/miR-509-3p axis promoted NSCLC progression by regulating cancer cell stemness, and targeting this signaling pathway could be is a promising therapeutic strategy to overcome NSCLC stemness.

Generation of mode-locked square-shaped and chair-like pulse based on reverse saturable absorption effect of nonlinear multimode interference.

In this paper, the phenomenon of reverse saturable absorption of offset-spliced graded index multimode fibers (OS-GIMF) is revealed. And based on that, the stable square-shaped and chair-like mode-locked pulses are demonstrated with the maximum pulse energy of 0.14 µJ and 23.8 nJ respectively, while the OS-GIMF acts as a saturable absorber (SA) in fiber laser. By adjusting polarization controller (PC) and the pump power, square-shaped and chair-like pulse can be switched to each other. This multimode SA could sever as high power light source owing to its high damage threshold, compact structure and low cost.

Ethical Inspection about laboratory animals.

Laboratory animals and animal experiments are foundations and important support conditions for life sciences, especially for medical research. The animal experiments have drawn extensive attention from the society because of the ethical issue. This paper takes Wenzhou Medical University as an example to give a brief introduction to the ethical review about laboratory animals in the university so as to further draw attention and concerns from the public about the ethical issue of laboratory animals. We successively introduce its scientific projects, nurturing environment and ethical review of laboratory animals.

Self-ligating brackets and their impact on oral health-related quality of life in Chinese adolescence patients: a longitudinal prospective study.

INTRODUCTION: Although the associations between orthodontic and oral health-related quality of life (OHRQOL) have been explored, little research has been done to address the influence of brackets type on perceived OHRQOL. The aim of this study was to assess whether the levels of OHRQOL in Chinese adolescence patients were influenced by the type of brackets. MATERIALS AND METHODS: One hundred fifty Chinese orthodontic adolescence patients completed the 14-item Oral Health Impact Profile (OHIP-14, Chinese version) at five distinct intervals: after insertion of the fixed appliance at 1 week (T1), 1 month (T2), 3 months (T3), and 6 months (T4); and after treatment (T5). RESULTS: Patients with self-ligating brackets were associated with less pain and discomfort at any intervals compared with conventional brackets, but no significant difference of overall OHIP-14 scores could be found between two groups. Moreover, in both groups, overall scores at T1 and T2 were significantly higher than the scores at any other intervals in both groups. CONCLUSIONS: The type of orthodontic appliance did not affect oral health-related quality of life in Chinese adolescence patients.