Application of quantitative real-time PCR to detect Mink Circovirus in minks, foxes and raccoon dogs in northern China

Mink circovirus disease caused by Mink Circovirus (MiCV) is a serious infectious disease of mink that has become prevalent in recent years in China, severely affecting the reproductive performance of mink and causing significant economic losses to farms. To date, there have been few studies on MiCV, its pathogenic mechanism is not clear, and there is no effective vaccine or drug to prevent and control the disease. Therefore, it is necessary to establish a rapid and reliable molecular diagnostic method, which would aid future studies of this novel virus. In our study, we developed a sensitive and specific TaqMan-based quantitative real-time PCR assay targeting the MiCV Cap gene. The assay showed no cross-reaction with other tested animal viruses. The assay is highly sensitive, with a detection limit of as low as 10 plasmid DNA copies and 2.38 × 10−2 pg of viral DNA. The intra and inter--assay coefficients of variation were both low. The positive detection rate of MiCV in clinical samples from minks, foxes, and raccoon dogs were 58.8% (133/226), 50.7% (72/142), and 42.2% (54/128), respectively, giving a total positive detection rate of 52.2% (259/496). Higher contamination levels were observed in samples from the environment in direct or indirect contact with animals, with a total positive detection rate of 75.1% (220/293). These epidemiological results showed that minks, foxes, and raccoon dogs had high infection rates of MiCV. This was also the first study to detect MiCV on the ground and equipment of fur-bearing animal farms. Our assay is highly sensitive and specific for the diagnosis and quantification of MiCV, and should provide a reliable real-time tool for epidemiological and pathogenetic study of MiCV infection

An Active Multi-Beam Antenna Design Method and Its Application for the Future 6G Satellite Network

The active multi-beam antenna can be widely used in the 6G integrated satellite network project, the national satellite Internet project, and other major satellite projects. It determines the key performance indicators of the satellite such as the service coverage area and the communication capacity of all the beams in the forward link and the return link. The active multi-beam antenna is the core technology of satellite payload and has been developed rapidly in recent years. Based on the antenna performance requirements such as the number of giant-scale beams, super-large coverage area, high gain, and high carrier-to-interference ratio (C/I), this paper proposes a new active multi-beam antenna design method, which integrates the multi-objective coordination and multi-feed amplitude and phase weighted optimization algorithms. A balanced optimal solution that meets the performance requirements can be obtained by constraining each other with different objective functions. In the optimization process, the surrogate model of convolutional autoencoder based on artificial intelligence technology is proposed for multi-objective optimization solution, which efficiently completes the search of optimal beam excitation coefficients. This paper takes the demand for very-high-throughput communication satellites serving the Asia-Pacific region as an example and applies the design method to the multi-beam antenna design of the satellite. The simulation verification of the antenna is completed, achieving good performance of 976 beams. All results meet the performance requirements, supporting the implementation of 1 Tbps communication capacity for the entire satellite, and verifying the correctness of the design method

First Prototype of a Cesium Oven Design for Negative-Ion-Source-Based Neutral Beam Injector at ASIPP

The RF-driven negative ion source has a steady state characteristic and will be a promising ion source for neutral beam injection (NBI) in the future. Cesium (Cs) injection is an efficient method to enhance the yield of negative ions during plasma discharge. In order to support the engineering and physical research in this field, the Cs oven prototype has been developed for negative ion source based neutral beam injector at ASIPP. This article presents the design details of a Cs oven system, including the constant temperature control system, the mechanical structure of Cs oven, and the surface ionization detector (SID). SID is a measurement method for the cesium flux in the nozzle. The experiment results of constant temperature control system show that the control accuracy and function meet the requirements of device operation. Meanwhile, the simulation analysis of Cs vapor concentration has been carried out in this paper. According to the simulation results, the graph of total Cs flux is given in the article, which presents the reference for the subsequent device testing

A wash-free SNAP-tag fluorogenic probe based on the additive effects of quencher release and environmental sensitivity

A 1,8-naphthalimide-derived fluorogenic probe was reported to label SNAP-tag fusion proteins in living cells. The probe can rapidly label a SNAP-tag and exhibit a fluorescence increase of 36-fold due to the additive effects of environment sensitivity of fluorophores and inhibition of photo-induced electron transfer from O-6-benzylguanine to the fluorophore. The labeling of intracellular proteins has been successfully achieved without a wash-out procedure

A naphthalimide-derived fluorogenic probe for SNAP-tag with a fast record labeling rate

SNAP-tag is one of most popular genetically encoded protein tags that can be labeled with fluorescent molecules for visualizing a protein of interest in live cells. Fluorogenic probes keep dark until they label protein tags, significantly improving the signal-to-noise ratio to image proteins without wash-out step. However, most of reported fluorogenic probes for SNAP-tag suffered from the low or mild labeling rate comparing with non-fluorogenic ones. In this paper, we reported a 4-amino-naphthliamide derived fluorogenic probe for SNAP-tag, which exhibited the fast record labeling rate among fluorogenic probes. Finally, we applied this probe to image proteins in mitochondria and nucleus in live cells without washout steps. (C) 2017 Elsevier Ltd. All rights reserved