Three-electrode electrochemical impedance technique was investigated for detection of Salmonella typhimurium by monitoring the growth of bacteria in selenite cystine (SC) broth supplemented with trimethylamine oxide hydrochloride (TMAO.HCl) and mannitol (M). The change in the system impedance during the growth of bacteria was studied using frequency spectral scanning. It was found that the impedance at low frequencies (<10 kHz) mainly came from the double-charged layer capacitance, reflecting the changes at the electrode interface and the adsorption on the electrode surface. While at high frequencies (>10 kHz), the system impedance mainly depended on the medium resistance. The adsorption of bacteria on the electrode surface was detected by measuring low frequency impedance, and verified with Faradic impedance spectroscopy. Enumeration of S. typhimurium using a low frequency (1 Hz) capacitance measurement and a high frequency (1 MHz) resistance measurement were compared. The detection times were determined for quantitative analysis based on the growth curves of bacteria referring to either the medium resistance or electrode capacitance. The regression equations for the detection times (t(d), h) and the initial cell number (N, cells.ml(-1)) were t(d)=-1.24logN+13.4 with R(2)=0.98 and t(d)=-1.40logN+14.46 with R(2)=0.97 for the medium resistance and electrode capacitance methods, respectively.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/s0956-5663(03)00229-x | DOI Listing |
RSC Adv
January 2025
The Center for Chemical Biology, School of Fundamental Science and Technology, Graduate School of Science and Technology, Keio University 3-14-1 Hiyoshi, Kohoku-ku Yokohama 223-8522 Japan +81-45-566-1580 +81-45-566-1839.
We prepared a cellulose nanofiber (CNF)-based porous membrane with three dimensional cellular structures. CNF was concentrated a surfactant-induced assembly by mixing CNF with a cationic surfactant, domiphen bromide (DB). Furthermore, they were accumulated by centrifugation to obtain a CNF-DB sol.
View Article and Find Full Text PDFWater Environ Res
January 2025
Zhejiang Key Laboratory of Petrochemical Environmental Pollution Control, Zhejiang Ocean University, Zhoushan, P. R. China.
The tolerance and degradation characteristics of a marine oil-degrading strain Acinetobacter sp. Y9 were investigated in the presence of diesel oil and simulated radioactive nuclides (Mn, Co, Ni, Sr, Cs) at varying concentrations, as well as exposure to γ-ray radiation (Co-60). The maximum tolerable concentrations for Coand Ni were found to be 5 mg/l and 25 mg/l, respectively, while the tolerable concentrations for Mn, Sr, and Cs exceeded 400 mg/l, 1000 mg/l, and 1000 mg/l, respectively.
View Article and Find Full Text PDFBMC Biol
January 2025
The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Science, Jiangsu Normal University, Xuzhou, Jiangsu, 221116, China.
Background: The variations in alliin content are a crucial criterion for evaluating garlic quality and is the sole precursor for allicin biosynthesis, which is significant for the growth, development, and stress response of garlic. WRKY transcription factors are essential for enhancing stress resistance by regulating the synthesis of plant secondary metabolites. However, the molecular mechanisms regulating alliin biosynthesis remain unexplored.
View Article and Find Full Text PDFJ Transl Med
January 2025
Siriraj Center of Research Excellence for Cancer Immunotherapy (SiCORE-CIT), Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Background: Multiple myeloma (MM) is an incurable plasma cell malignancy with increasing global incidence. Chimeric antigen receptor (CAR) T-cell therapy targeting BCMA has shown efficacy in relapsed or refractory MM, but it faces resistance due to antigen loss and the tumor microenvironment. Bispecific T-cell engaging (BITE) antibodies also encounter clinical challenges, including short half-lives requiring continuous infusion and potential toxicities.
View Article and Find Full Text PDFJ Mater Chem B
January 2025
Research Center for Macromolecules and Biomaterials, National Institute for Materials Science, Ibaraki 305-0044, Japan.
The colon possesses a unique physiological environment among human organs, where there is a highly viscous body fluid layer called the mucus layer above colonic epithelial cells. Dysfunction of the mucus layer not only contributes to the occurrence of colorectal cancer (CRC) but also plays an important role in the development of chemoresistance in CRC. Although viscosity is an essential property of the mucus layer, it remains elusive how viscosity affects chemoresistance in colon cancer cells.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!