Airborne contamination by 99Tcm has been monitored in the Nuclear Medicine Department in our hospital to assess the risk of internal contamination to occupational workers exposed to Technegas studies. An air sampler fitted with a membrane filter was used. The optimum time for air absorption for obtaining the maximum activity in the filter was calculated. Maximum activity in the membrane filter ensures minimum uncertainty, which is especially important when low-level activities are being measured. The optimum time depends on air absorption velocity, room volume and filter efficiency for isotope collection. It tends to 1/lambda (lambda = disintegration constant for 99Tcm) for large volume and low velocity. Room activity with the air pump switched on was related to filter activity, and its variation with time was studied. Free activity in air for each study was approximately 7 x 10(-4) the activity used, and the effective half-life of the isotope in the room was 13.9 min (decay and diffusion). For a typical study (630 MBq), the effective dose to staff was 0.01 microSv when in the room for 10 min.
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http://dx.doi.org/10.1097/00006231-199912000-00006 | DOI Listing |
Environ Sci Technol
January 2025
State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
The effects of particulate matter (PMs) from different cities on the nervous system remain unclear. In this study, aqueous solutions of 0.45 μm membrane-filtered PM from 31 major Chinese cities were intravenously administered to rats.
View Article and Find Full Text PDFRSC Adv
January 2025
Centre for Advanced Materials and Devices (CAMD), Department of Chemistry, Faculty of Science, University of Colombo Colombo Sri Lanka
The global scarcity of irrigation-grade water poses severe concerns in the agricultural sector. Desalination techniques including reverse osmosis, electrodialysis, capacitive deionization, membrane filtration, and multi-stage flash are some dynamic solutions to mitigate this challenge. In this study, novel bio-filter materials were explored and developed for the application of membrane-based electrodialysis.
View Article and Find Full Text PDFFood Chem X
January 2025
State Key Laboratory of Digital Medical Engineering, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
Here, we report a SERS based VFA using PNC as a sensing substrate for highly sensitive multiplex mycotoxins detection. The PNC was fabricated by filtration-based self-assembled monodisperse SiO NPs on a filter membrane as a template, and the obtained PNC had an ordered complementary inverse opal structure. In parallel, three kinds of Raman dyes encoding Au@Ag, Au@Ag and Au@Ag SERS nanotags were synthesized for the detection of OTA, AFB1 and ZON.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Pharmaceutical Chemistry, Semmelweis University, Hőgyes Endre U. 9, 1092, Budapest, Hungary.
Microtiter-plate-based systems are unified platforms of high-throughput experimentation (HTE). These polymeric devices are used worldwide on a daily basis-mainly in the pharmaceutical industry-for parallel syntheses, reaction optimization, various preclinical studies and high-throughput screening methods. Accordingly, laboratory automation today aims to handle these commercially available multiwell plates, making developments focused on their modifications a priority area of modern applied research.
View Article and Find Full Text PDFProg Neurobiol
January 2025
Department of Biomedicine, University of Basel, Klingelbergstrasse 50, Basel 4056, Switzerland. Electronic address:
The brain faces the challenging task of preserving a consistent portrayal of the external world in the face of disruptive sensory inputs. What alterations occur in sensory representation amidst noise, and how does brain activity adapt to it? Although it has previously been shown that background white noise (WN) decreases responses to salient sounds, a mechanistic understanding of the brain processes responsible for such changes is lacking. We investigated the effect of background WN on neuronal spiking activity, membrane potential, and network oscillations in the mouse central auditory system.
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