Modelling Resonance Dependent Angular Distribution via DBRC in Monte Carlo Codes

R. Dagan,B. Becker,Y. Danon,M. Rapp,G. Lohnert 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.23

The development of a new energy dependent double differential resonance scattering kernel by Rothenstein & Dagan, Annals of Nuclear Energy (1998) was shown to have a significant impact on core calculations as far as their criticality, Doppler Effect and the nuclide inventory is concerned. Thereafter, it was of great interest to experimentally validate this scattering kernel in addition to analytically proving its consistency with the integral Doppler broadened cross section, which was achieved by integrating the new kernel over all angles and all scattered energies. This study deals with the unique experiment suggested by Y. Danon at the Gaerttner Linear Accelerator Laboratory at Rensselaer Polytechnic Institute (RPI). The main advantage of this facility is the ability to move the neutron production source off axis relative to the detector beam line. It was, therefore, possible to position the sample, from which the neutron were scattered, on the same axis as the detector. In this way it was possible to directly measure the angular distribution of scattered neutron from heavy nuclides with pronounced resonances. In this study the previous results obtained for ^(238)U were extended to ^(232)Th. Improvements were made to the new resonance scattering kernel by development of a stochastic formalism known as DBRC (Doppler Broadened Rejection Correction) which was implemented by Becker et al. in several Monte Carlo codes. Based on the good agreement between this DBRC model and the measurements presented in this paper, it was shown that the standard asymptotic back angle scattering used previously in Monte Carlo codes differs by almost 80% for highly scattering resonances. Moreover, the scattering angle measurements and the ability to simulate it accurately by means of stochastic methods emphasized the deficiencies of the current methods which use only transmission and capture measurements.

Postprandial Lipid Concentrations and Daytime Biological Variation of Lipids in a Healthy Chinese Population

Dagan Yang,Qian Cai,Xinglun Qi,Yunxian Zhou 대한진단검사의학회 2018 Annals of Laboratory Medicine Vol.38 No.5

Background: Several latest guidelines and consensus statements from Europe and the United States specify that there is no need for fasting prior to routine lipid tests. However, the latest Chinese guidelines still recommend fasting tests owing to a lack of local evidence. This study aimed to investigate postprandial lipid concentrations and daytime biological variation of lipids in a healthy Chinese population. Methods: Venous blood samples were collected from 41 ostensibly healthy Chinese volunteers at five time points during the day (06:30, 09:00, 12:00, 15:00, and 18:30). The same batch of reagents was used to determine lipid concentrations. A nested ANOVA was performed to calculate within-subject biological variation (CVI) and between-subject biological variation (CVG). Results: Postprandial concentrations of triglyceride were higher than fasting concentrations, with the maximum change occurring at 12:00 (0.5 hours after lunch, 0.21±0.65 mmol/L difference). The daytime biological variation of triglycerides was relatively high (CVI=25%, CVG=35.9%). The postprandial concentrations of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, apolipoprotein A1, and apolipoprotein B were mostly lower than the fasting concentrations, and their daytime biological variations were relatively low (CVI=2.4–4.4%, CVG=11.8–18.7%).

Use of ultra-low cost fitness trackers as clinical monitors in low resource emergency departments

Alon Dagan,Oren J Mechanic 대한응급의학회 2020 Clinical and Experimental Emergency Medicine Vol.7 No.3

In low resource hospitals, strained staffing ratios and lack of telemetry can put patients at risk for clinical deterioration and unexpected cardiac arrest. While traditional telemetry systems can provide real-time continuous vital signs, they are too expensive for widespread use in these settings. At the same time, developed countries such as the United States have been increasingly utilizing remote monitoring systems to shift patient care from hospital to home. While the context is dramatically different, the challenge of monitoring patients in otherwise unmonitored settings is the same. At-home monitoring solutions range from highly comprehensive and expensive systems to inexpensive fitness trackers. In the field of global health, the adoption of this technology has been somewhat limited. We believe that low cost fitness trackers present an opportunity to address the challenge of vital sign monitoring in resource-poor settings at a fraction of the cost of existing technical solutions.

Disability Progression in Multiple Sclerosis Is Afected by the Emergence of Comorbid Arterial Hypertension

Amir Dagan,Irina Gringouz,Iris Kliers,Gad Segal 대한신경과학회 2016 Journal of Clinical Neurology Vol.12 No.3

Background and PurposezzWe assessed the prevalence and potential association of hypertension with multiple sclerosis (MS)-related disability progression. MethodszzTis was a retrospective study of 2,813 patients who were followed for 20 years. We modeled the associations of several risk factors with the pattern of disability progression. Te primary end point was the rate of disability progression. ResultszzIn total, 2,396 patients were available for analysis, of which 1,074 (44.8%) scored 4 (EDSS4) on the Expanded Disability Status Scale (EDSS), 717 (29.9%) scored 6 (EDSS6), and 261 (10.9%) scored 8 (EDSS8). The mean times to reach scores of 4, 6, and 8 were 123.5, 163.1, and 218.9 months, respectively. Hypertension was present in 207 (8.6%) patients during follow-up. Hypertension was associated with a higher probability of reaching each EDSS score compared to non-hypertensive patients: 62% vs. 43% for EDSS4 (p<0.01), 51% vs. 28% for EDSS6 (p<0.01), and 17% vs. 10% for EDSS8 (p<0.01). Nevertheless, hypertensive MS patients experienced longer intervals to reach each EDSS score: longer by 51.6, 38.9, and 62.7 months to EDSS4, EDSS6, and EDSS8, respectively (p<0.01) when compared to non-hypertensive MS patients reaching the same EDSS scores. ConclusionszzDisability progression is more prevalent amongst hypertensive MS patients. However, they experience longer time intervals between the stages of disability progression.

Measurements of the Neutron Scattering Spectrum from 238U and Comparison of the Results with a Calculation at the 36.68-eV Resonance

Tae-Ik Ro,Yaron Danon,Emily Liu,Devin P. Barry,Ron Dagan 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.4

Neutrons elastically scattered from 238U were measured in the neutron energy region from 5 to 120 eV by using a Ta target with the 60-MV electron linear accelerator (LINAC) of RPI (Rensselaer Polytechnic Institute). The neutron energy, having a continuous spectrum, was measured by using the neutron time-of-flight (TOF) method and a 6Li scintillation detector. Two different thickness depleted uranium samples, 169 and 362 g of 7.62 × 7.62 cm2, were used in the experiments. The spectra of scattered neutrons were measured at 25.5 m from the U sample by using a 6Li detector, and the scattering direction was ∼39˚ forward from the direction of the incident neutrons. The peaks and the dips around resonance energy of the measured spectrum were identified and compared to the ENDF/B-VII.0 cross-section of 238U for the same neutron energy. The experimental 36.68- eV resonance was compared with the calculation results. The experimental and the calculation results can be used as reference data for benchmarking neutron scattering models in simulation codes. Neutrons elastically scattered from 238U were measured in the neutron energy region from 5 to 120 eV by using a Ta target with the 60-MV electron linear accelerator (LINAC) of RPI (Rensselaer Polytechnic Institute). The neutron energy, having a continuous spectrum, was measured by using the neutron time-of-flight (TOF) method and a 6Li scintillation detector. Two different thickness depleted uranium samples, 169 and 362 g of 7.62 × 7.62 cm2, were used in the experiments. The spectra of scattered neutrons were measured at 25.5 m from the U sample by using a 6Li detector, and the scattering direction was ∼39˚ forward from the direction of the incident neutrons. The peaks and the dips around resonance energy of the measured spectrum were identified and compared to the ENDF/B-VII.0 cross-section of 238U for the same neutron energy. The experimental 36.68- eV resonance was compared with the calculation results. The experimental and the calculation results can be used as reference data for benchmarking neutron scattering models in simulation codes.

A Nurse-led International Cohort for Disease Prevention: The International Network for Cascade Genetic Screening in Hereditary Cancer

Bora Moon,Yonju Yoo,Jiyoon Jang,Yeeun Kim,Sivia Barnoy,Efrat Dagan,Maria Katapodi,Sue Kim 한국간호과학회 2023 한국간호과학회 학술대회 Vol.2023 No.11

Structural Switch of Lysyl-tRNA Synthetase between Translation and Transcription

Ofir-Birin, Y.,Fang, P.,Bennett, Steven P.,Zhang, H.M.,Wang, J.,Rachmin, I.,Shapiro, R.,Song, J.,Dagan, A.,Pozo, J.,Kim, S.,Marshall, Alan G.,Schimmel, P.,Yang, X.L.,Nechushtan, H.,Razin, E.,Guo, M. Cell Press 2013 Molecular Cell Vol.49 No.1

Lysyl-tRNA synthetase (LysRS), a component of the translation apparatus, is released from the cytoplasmic multi-tRNA synthetase complex (MSC) to activate the transcription factor MITF in stimulated mast cells through undefined mechanisms. Here we show that Ser207 phosphorylation provokes a new conformer of LysRS that inactivates its translational function but activates its transcriptional function. The crystal structure of an MSC subcomplex established that LysRS is held in the MSC by binding to the N terminus of the scaffold protein p38/AIMP2. Phosphorylation-created steric clashes at the LysRS domain interface disrupt its binding grooves for p38/AIMP2, releasing LysRS and provoking its nuclear translocation. This alteration also exposes the C-terminal domain of LysRS to bind to MITF and triggers LysRS-directed production of the second messenger Ap<SUB>4</SUB>A that activates MITF. Thus our results establish that a single conformational change triggered by phosphorylation leads to multiple effects driving an exclusive switch of LysRS function from translation to transcription.

Can a low-cost exercise monitor provide useful heart rate monitoring for use in low-resource emergency departments?

Thomas A. O’Mara,Miguel Armengol de la Hoz,Oren J. Mechanic,Alon Dagan 대한응급의학회 2021 Clinical and Experimental Emergency Medicine Vol.8 No.3

Objective Our objective was to study the clinical monitoring capabilities of a low-cost fitness wristband while measuring patient satisfaction with a mobility permitting device in the emergency department. Methods Patients enrolled were on continuous three-lead telemetry monitoring in a high acuity zone of the emergency department. Patients were given a fitness band to wear while simultaneously monitored with standard three-lead monitor. A brief survey was conducted upon study end, and data was compared between wristband and three-lead telemetry. Median heart rate (HR) values were calculated, a Bland-Altman plot was generated, and sensitivity and specificity were calculated for comparison of the formal telemetry and the inexpensive wristband. Results Thirty-four patients with an average age of 61.5 years were enrolled. From June to October 2019, over 100 hours of data were collected. In comparison for comfort, participants scored 9.5 of 10, preferring wristband over telemetry. Using a correlation coefficient graph, we found a significant disparity of HR readings within a telemetry range of 40 to 140 beats/min. An R-value of 0.36 was detected. Using a Bland-Altman plot, we observed a significant difference in HR between the telemetry monitor and the wristband. The sensitivity and specificity of the wristband to detect bradycardia (HR <60 beats/min) were 76% and 86%, respectively, while the sensitivity and specificity of the wristband to detect tachycardia (HR >100 beats/min) were 92% and 51%, respectively. Conclusion Inexpensive fitness bands cannot be a suitable tool for monitoring patient’s HR because of inaccuracy in detecting bradycardia or tachycardia.

Lifestyle modifications in an adolescent dormi­tory: a clinical trial

Abu-Kishk, Ibrahim,Alumot-Yehoshua, Michal,Reisler, Gadi,Efrati, Shai,Kozer, Eran,Doenyas-Barak, Keren,Feldon, Michal,Dagan, Zahi,Reifen, Rami,Berkovitch, Matitiahu The Korean Pediatric Society 2014 Clinical and Experimental Pediatrics (CEP) Vol.57 No.12

Purpose: Childhood obesity is an increasing public health issue worldwide. We examined dietary patterns among adolescents in a dormitory school, identified obese adolescents and tried to intervene to improve food habits and physical activity. Methods: We conducted an experimental prospective longitudinal study based on 36 obese (body mass index $[BMI]{\geq}95th$ percentile) adolescents (aged 12-18 years) compared with controls (healthy children: normal age-appropriate BMI ($BMI{\leq}85th$ percentile). Six months' intervention included lifestyle-modification counseling (once a week by a clinical dietician), and an exercise regimen twice a week, 60 minutes each time, instructed by a professional pediatric trainer). Both groups underwent baseline measurements at the beginning of the study and 6 months later (arterial stiffness, blood pressure, pulse, weight and height, hemoglobin, creatinine, liver enzymes, highly sensitive C-reactive protein and complete lipid profile). Results: Twenty-one participants completed the study. Low compliance from participants, school staff and parents was observed (participation in planned meetings; 71%-83%). BMI significantly decreased from $32.46{\pm}3.93kg/m^2$ to $30.32{\pm}3.4kg/m^2$ (P=0.002) in the study group. Arterial stiffness was not significantly different between the 2 groups and did not change significantly after 6 months' intervention (P=0.494). No significant changes in CRP and lipid profile were observed after the intervention. Conclusion: Making lifestyle modifications among adolescents in a dormitory school is a complex task. Active intervention indeed ameliorates BMI parameters. However, in order to maximize the beneficial effects, a multidisciplinary well-trained team is needed, with emphasis on integrating parents and the school environment.

Lifestyle modifications in an adolescent dormitory: a clinical trial

Ibrahim Abu-Kishk,Michal Alumot-Yehoshua,Gadi Reisler,Shai Efrati,Eran Kozer,Keren Doenyas-Barak,Michal Feldon,Zahi Dagan,Rami Reifen,Matitiahu Berkovitch 대한소아청소년과학회 2014 Clinical and Experimental Pediatrics (CEP) Vol.57 No.12

Purpose: Childhood obesity is an increasing public health issue worldwide. We examined dietarypatterns among adolescents in a dormitory school, identified obese adolescents and tried to interveneto improve food habits and physical activity. Methods: We conducted an experimental prospective longitudinal study based on 36 obese (bodymass index [BMI]≥95th percentile) adolescents (aged 12–18 years) compared with controls (healthychildren: normal age-appropriate BMI (BMI≤85th percentile). Six months’ intervention includedlifestyle-modification counseling (once a week by a clinical dietician), and an exercise regimen twicea week, 60 minutes each time, instructed by a professional pediatric trainer). Both groups underwentbaseline measurements at the beginning of the study and 6 months later (arterial stiffness, bloodpressure, pulse, weight and height, hemoglobin, creatinine, liver enzymes, highly sensitive C-reactiveprotein and complete lipid profile). Results: Twenty-one participants completed the study. Low compliance from participants, schoolstaff and parents was observed (participation in planned meetings; 71%–83%). BMI significantlydecreased from 32.46±3.93 kg/m2 to 30.32±3.4 kg/m2 (P=0.002) in the study group. Arterialstiffness was not significantly different between the 2 groups and did not change significantly after 6months’ intervention (P=0.494). No significant changes in CRP and lipid profile were observed afterthe intervention. Conclusion: Making lifestyle modifications among adolescents in a dormitory school is a complex task. Active intervention indeed ameliorates BMI parameters. However, in order to maximize the beneficialeffects, a multidisciplinary well-trained team is needed, with emphasis on integrating parents and theschool environment.