A Portable Nucleic Acid Sensor Based on PCR for Simple, Rapid, and Sensitive Testing of Botrytis cinerea in Ginseng.

Botrytis cinerea is a ubiquitous pathogen that can infect at least 200 dicotyledonous plant species including many agriculturally and economically important crops. In Ginseng, the fungus may cause ginseng gray mold disease, causing great economic losses in the ginseng industry. Therefore, the early detection of B. cinerea in the process of ginseng production is necessary for the disease prevention and control of the pathogen's spread. In this study, a polymerase chain reaction-nucleic acid sensor (PCR-NAS) rapid detection technique was established, and it can be used for field detection of B. cinerea through antipollution design and portable integration. The present study showed that the sensitivity of PCR-NAS technology is 10 times higher than that of traditional PCR-electrophoresis, and there is no need for expensive detection equipment or professional technicians. The detection results of nucleic acid sensors can be read by the naked eye in under 3 min. Meanwhile, the technique has high specificity for the detection of B. cinerea. The testing of 50 field samples showed that the detection results of PCR-NAS were consistent with those of the real-time quantitative PCR (qPCR) method. The PCR-NAS technique established in this study can be used as a novel nucleic acid field detection technique, and it has a potential application in the field detection of B. cinerea to achieve early warning of the pathogen infection.

Gas-flow humidity control system for neutron reflectivity measurements.

We developed a novel humidity control system for neutron reflectivity measurements based on the two-way gas-flow method that can generate up to 85% relative humidity (RH) within a temperature range of 5 °C-85 °C. The system consists of a gas-flow-type humidity generator and a thermostatic sample chamber, each of which can independently control the temperature. The key features include rapid humidity response and long stable operation time. The humidity reaches equilibrium within 2 to 5 min during the humidity change, and the system exhibited acceptable stability over a three-day, nonstop experimental measurement duration, with a precision of ±1% RH at 85 °C and 85% RH. The sample chamber is capable of measuring substrate samples with dimensions of up to 2-in. in diameter and 5-mm in thickness. We demonstrate the reflectivity data measured at a pulsed neutron facility, MLF BL17, in the Japan Proton Accelerator Research Complex. The combined use of this system with neutrons permits in situ, time-resolved studies of the swelling process of polyvinyl alcohol and adhesive materials.

Development of a biaxial tensile testing machine for pulsed neutron experiments.

A biaxial tensile testing method has been used to get macroscopic information on elastoplastic deformation of a thin steel specimen and improve the accuracy of plastic processing of steel materials. We newly developed a biaxial tensile testing machine for pulsed neutron experiments (BTM-NEU) to provide the microscopic crystallographic information of steel materials under biaxial load and correlate it with the macroscopic mechanical properties of the materials. The performance of the BTM-NEU was experimentally evaluated with cold-rolled mild steel and hot-rolled high-tensile-strength steel materials and compared with that of a standard biaxial tensile testing machine (BTM-std) as follows. •The BTM-NEU can test an ISO-standardized cruciform specimen as the BTM-std and its performance is equivalent to that of the BTM-std.•The BTM-NEU has excellent long-time reliability and stability necessary for pulsed neutron experiments, especially Bragg-edge neutron imaging experiments.•The BTM-NEU can be applied to pulsed neutron experiments using a Bragg-edge imaging method.