Chemical Composition, Antibacterial Activity of the Essential Oil from Roots of <i>Radix aucklandiae</i>against Selected Food-Borne Pathogens

Radix aucklandiae from Yunnan Province in China is a significant medicinal plant. In the present study, the essential oil composition from?Radix aucklandiae roots was investigated by gas chromatography-mass spectrometry (GC-MS). A total of 23 compounds representing 57.95% of the essential oil were tentatively identified. The main constituents were eremanthin (12.74%), d-Guaiene (6.26%), ζ-Himachalene (6.16%) and l-Caryophyllene (4.84%). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the essential oil from R. aucklandiae were evaluated against three Gram-positive bacteria (Staphylococcus aureus, Staphylococcus albus and Bacillus subtilis) three Gram-negative bacteria (Salmonella typhimurium, Escherichia coli and Shigella dysenteriae). Results revealed that the essential oil exhibited significant in vitro antimicrobial property. Among all the tested microorganisms, the essential oil showed the strongest inhibitory effect against S. typhimurium. The data of this study suggests that the essential oil from Radix aucklandiae has great potential for application as a natural antimicrobial agent to preserve food.

Emerging single-photon detection technique for high-performance photodetector

Single-photon detections(SPDs)represent a highly sensitive light detection technique capable of detecting individual photons at extremely low light intensity levels.This technology mainly relies on the mainstream SPDs,such as photomultiplier tubes(PMTs),avalanche photodiodes(SAPD),superconducting nanowire single-photon detectors(SNSPDs),supercon-ducting transition-edge sensor(TES),and hybrid lead halide perovskite.However,the complexity and high manufacturing cost,coupled with the requirement of special conditions like a low-temperature environment,pose significant challenges to the wide adoption of SPDs.To address the challenges faced by SPDs,significant efforts have been devoted to enhan-cing their performance.In this review,we first summarize the principles and technical challenges of several SPDs.Conductors,superconductors,semiconductors,3D bulk materials,2D film materials,1D nanowires,and OD quantum dots have all been discussed for single-photon detectors.Methods such as special optical structure,waveguide integration,and strain engineering have been employed to elevate the performance of single-photon detectors.These techniques enhance light absorption and modulate the band structure of the material,thereby improving the single-photon sensitivity.By providing an overview of the current situation and future challenges of SPDs,this review aims to propose potential solutions for photon detection technology.