Johansenwaller1111

Accurate neutron spectrum measurements at light source facilities are difficult to perform because of relatively low and time-varying neutron intensities. A homemade Bonner cylinder spectrometer was used to determine the energy spectra of neutrons outside the lateral shielding wall of the Taiwan Photon Source before and after the installation of local injection shielding. The spectrometer, similar to the design of conventional Bonner spheres, features (1) highly sensitive neutron detection and (2) a wide-range response to neutrons with energies up to the GeV range. Neutron measurements were conducted by intentionally parking the injected 3-GeV electrons at the septum of the storage ring. On the basis of high-fidelity FLUKA simulations, neutron spectra at the measurement location under the experimental conditions were obtained and adopted as an initial guess for spectrum unfolding. The neutron spectra determined before and after the local shielding were comprehensively compared in terms of their intensities and characteristics. The local shielding resulted in overall reductions of approximately 44% and 38% in total neutron flux and dose rate, respectively. Both before and after the local shielding, high-energy neutrons (>10 MeV) were the dominant component of the radiation field, which contributed approximately 30% to 35% of the total neutron flux and 55% to 59% of the total neutron dose rate.Radiation workers might be exposed to polyenergetic photon radiation beams at different directions in their working environments. In this regard, their effective dose (E) should be accurately estimated using a two-dosimeter algorithm (TDA), based on the measurements of two thermoluminescent dosimeters (TLDs) or film badges that are mounted on the front and back of the body. However, considering different human anatomies, radiation workers may have a variety of weight percentiles. This work sought to find whether TDA obtained for the reference weight percentile (50) can be used for higher weight percentiles (including; 65, 75, 85, and 95). MCNPX was used to simulate different weight percentiles on the revised ORNL phantom by adding extra layers of muscle and adipose on the torso. Then front and back TLD responses were calculated for external beam photon energies of 40 keV to 10 MeV in different irradiation geometries. The results revealed that E value declines with increasing the weight percentile. In this study, three TDA were investigated consisting of Eest = 0.73 Rf + 0.53 Rb (73/53), Eest = 0.55 Rf + 0.50 Rb (55/50), and Eest = 0.70 Rf + 0.30 Rb (70/30). The ratio of Eest/E was calculated for each TDA in different energy bins and weight percentiles. Results obtained using the 55/50 and 70/30 showed higher underestimation for most of the energy bins, especially for PA and AP geometries. Compared to these two TDA, the 73/53 algorithm resulted in higher overestimation for RLAT and LLAT geometries for the same energy bins. Variation of the algorithms showed a similar trend for the studied weight percentiles. To conclude, results obtained by TDA for the 50% weight percentile are applicable for weight percentiles >50%.Radiofrequency electromagnetic fields (EMFs) are used to enable a number of modern devices, including mobile telecommunications infrastructure and phones, Wi-Fi, and Bluetooth. As radiofrequency EMFs at sufficiently high power levels can adversely affect health, ICNIRP published Guidelines in 1998 for human exposure to time-varying EMFs up to 300 GHz, which included the radiofrequency EMF spectrum. Since that time, there has been a considerable body of science further addressing the relation between radiofrequency EMFs and adverse health outcomes, as well as significant developments in the technologies that use radiofrequency EMFs. Accordingly, ICNIRP has updated the radiofrequency EMF part of the 1998 Guidelines. This document presents these revised Guidelines, which provide protection for humans from exposure to EMFs from 100 kHz to 300 GHz.OBJECTIVES Little is known on causative pathogens of intravascular catheters infection according to the catheter insertion site. The present study aimed to describe the epidemiology of causative microorganisms of catheter-related infection and colonization according to the insertion site. PRN2246 DESIGN Multicenter observational study using data from four large randomized controlled trials investigating different prevention strategies in which extensive prospective high-quality data collection at catheter insertion and catheter removal was performed. SETTING Twenty-five ICUs in France. PATIENTS Patients were recruited from 2006 to 2014 as soon as they required a catheterization with a short-term central venous catheter or peripheral arterial catheter with an expected duration of use of more than 48 hours. We described the distribution of microorganisms in central venous catheter and arterial catheter-related bloodstream infections and colonization according to the insertion type (femoral vs nonfemoral) included in th frequently observed at the femoral site (20% vs nonfemoral site 12%; p = 0.01). CONCLUSIONS The proportion of intravascular catheter infections due to nonfermenting Gram-negative bacilli was high for the femoral insertion site. Empirical antipseudomonal therapy should be considered if a femoral catheter-related bloodstream infection is suspected.OBJECTIVES To elucidate the impact of early tracheostomy on hospitalization outcomes in patients with traumatic brain injury. DATA SOURCES Lilacs, PubMed, and Cochrane databases were searched. The close-out date was August 8, 2018. STUDY SELECTION Studies written in English, French, Spanish, or Portuguese with traumatic brain injury as the base trauma, clearly formulated question, patient's admission assessment, minimum follow-up during hospital stay, and minimum of two in-hospital outcomes were selected. Retrospective studies, prospective analyses, and case series were included. Studies without full reports or abstract, commentaries, editorials, and reviews were excluded. DATA EXTRACTION The study design, year, patient's demographics, mean time between admission and tracheostomy, neurologic assessment at admission, confirmed ventilator-assisted pneumonia, median ICU stay, median hospital stay, mortality rates, and ICU and hospital costs were extracted. DATA SYNTHESIS A total of 4,219 studies were retrieved and screened.