Analysis of nuclear reactions to determine the radionuclides generated and its activity in various devices

[EN] Nuclear reactions can generate radionuclides and it is necessary to know the activity produced in the reaction. Most of the activation reactions are induced by neutrons since the addition of one neutron produces normally an instability in the nucleus, but other particles like protons can also be used to produce radionuclides. Nuclear reactors and accelerators are some of the most used devices to host nuclear reactions to produce radionuclides for various applications. The MCNP5 code based on the Monte Carlo (MC) method can be used to estimate the activity generated in the reaction. A summary of the simulation of neutron reactions is presented in the paper. The comparison of simulation results with experimental measurements allows the validation of developed models.Ródenas Diago, J.; Verdú Martín, GJ. (2020). Analysis of nuclear reactions to determine the radionuclides generated and its activity in various devices. Radiation Physics and Chemistry. 167:1-6. https://doi.org/10.1016/j.radphyschem.2019.05.011S16167Ródenas, J., Gallardo, S., Abarca, A., & Juan, V. (2010). Estimation of the activity generated by neutron activation in control rods of a BWR. Applied Radiation and Isotopes, 68(4-5), 905-908. doi:10.1016/j.apradiso.2009.09.059Ródenas, J., Abarca, A., Gallardo, S., & Sollet, E. (2010). Validation of the Monte Carlo model developed to assess the activity generated in control rods of a BWR. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 619(1-3), 258-261. doi:10.1016/j.nima.2009.10.084Ródenas, J., Gallardo, S., Abarca, A., & Juan, V. (2010). Analysis of the dose rate produced by control rods discharged from a BWR into the irradiated fuel pool. Applied Radiation and Isotopes, 68(4-5), 909-912. doi:10.1016/j.apradiso.2009.09.060Ródenas, J., Gallardo, S., Weirich, F., & Hansen, W. (2014). Application of dosimetry measurements to analyze the neutron activation of a stainless steel sample in a training nuclear reactor. Radiation Physics and Chemistry, 104, 368-371. doi:10.1016/j.radphyschem.2014.05.01

Aplicación de mensajería P2P cifrada y descentralizada

[ES] Actualmente, las aplicaciones de mensajería instantánea no permiten el envío p2p de mensajes entre usuarios. Estos son enviados a un servidor intermediario donde son almacenados a la espera de poder ser enviados al destinatario. El problema que se pretende abordar es la eliminación de ese servidor intermediario. De otro lado, las aplicaciones existentes que intentan resolver ese problema tienen fallos a nivel de privacidad y seguridad. Es por ello en este trabajo se llevará a cabo una nueva aplicación de mensajería instantánea punto a punto, capaz de proporcionar confidencialidad, autenticidad e integridad durante la transmisión de los mensajes. Además, asegurará la privacidad de los datos del usuario que se encuentren almacenados a nivel local. En conclusión, se ha desarrollado tanto un servidor de identificadores, empleado para que diferentes instancias de la aplicación puedan comunicarse entre sí, como una aplicación, que proporciona Perfect Forward Secrecy para la transmisión de mensajes y el cifrado para todos los datos del usuario almacenados en la base de datos.[EN] Nowadays, instant messaging applications do not allow sending p2p messages between users. These are sent to an intermidiary server where they are stored waiting to be sent to the recipient. The problem to be tackled is the elimination of the intermediary server. On the other hand, existing applications that try to solve this problem have privacy and security flaws. That is why in this work a new point-to-point instant messaging application will be carried out, capable of providing confidenciality, authenticity and integrity during the transmission of messages. In addition, it will ensure the privacy of user data that is stored locally. In conclusion, both an identifier server, used so that different instances of the application can communicate with each other, and an application that provides Perfect Forward Secrecy for the transmission of messages and encryption for all user data stored in the database.[CA] Actualment, les aplicacions de missatgeria instantània no permeten l’enviament p2p de missatges entre usuaris. Aquests són enviats a un servidor intermediari on són emmagatzemats a l’espera de poder ser enviats al destinatari. El problema que es pretén abordar és l’eliminació d’aqueix servidor intermediari. D’altra banda, les aplicacions existents que intenten resoldre aqueix problema tenen fallades a nivell de privacitat i seguretat. És per això en aquest treball es durà a terme una nova aplicació de missatgeria instantània punt a punt, capaç de proporcionar confidencialitat, autenticitat i integritat durant la transmissió dels missatges. A més, assegurarà la privacitat de les dades de l’usuari que es troben emmagatzemats a nivell local. En conclusió, s’ha desenvolupat tant un servidor d’identificadors, emprat perquè diferents instàncies de l’aplicació puguen comunicar-se entre si, com una aplicació, que proporciona Perfect Forward Secrecy per a la transmissió dels missatges i el xifrat per a totes les dades de l’usuari enmagatzemades a la base de dades.Ródenas Huerta, J. (2020). Aplicación de mensajería P2P cifrada y descentralizada. http://hdl.handle.net/10251/150149TFG

Unfolding X-ray spectra using a flat panel detector. Determination of the accuracy of the method with the Monte Carlo method

[EN] The primary X-ray spectrum depends on different parameters such as high voltage, filament current, high voltage ripple, anode angle and thickness of filter material. The objective of this work is to determine whether the unfolding technique based on the Tikhonov regularization method is accurate enough to estimate the X-ray spectrum when slight changes in the operation variables are considered. In this frame, several X-ray spectra are considered (extracted from the IPEM78 Catalogue Report) varying the main operation variables of the X-ray tube (high voltage, voltage ripple, filter thickness and filter material). With those spectra, the corresponding absorbed dose curves are obtained by simulation with a MCNP5 model reproducing a flat panel detector and a PMMA wedge. Once the absorbed dose curves are simulated and applying the unfolding Tikhonov regularization method, the unfolded spectrum is obtained, which is finally compared with the theoretical one (IPEM78 Catalogue Report). Discrepancies between unfolded and primary X-ray spectra can be attributed to the fact that this is an ill-posed problem, and the unfolding of the spectrum is strongly affected by the method used to improve the conditioning of the response function (response matrix).Gallardo Bermell, S.; Ródenas Diago, J.; Verdú Martín, GJ. (2019). Unfolding X-ray spectra using a flat panel detector. Determination of the accuracy of the method with the Monte Carlo method. Radiation Physics and Chemistry. 155:233-238. https://doi.org/10.1016/j.radphyschem.2018.09.014S23323815

Multimorbidity as specific disease combinations, an important predictor factor for mortality in octogenarians: the Octabaix study

BACKGROUND: The population is aging and multimorbidity is becoming a common problem in the elderly. OBJECTIVE: To explore the effect of multimorbidity patterns on mortality for all causes at 3- and 5-year follow-up periods. MATERIALS AND METHODS: A prospective community-based cohort (2009-2014) embedded within a randomized clinical trial was conducted in seven primary health care centers, including 328 subjects aged 85 years at baseline. Sociodemographic variables, sensory status, cardiovascular risk factors, comorbidity, and geriatric tests were analyzed. Multimorbidity patterns were defined as combinations of two or three of 16 specific chronic conditions in the same individual. RESULTS: Of the total sample, the median and interquartile range value of conditions was 4 (3-5). The individual morbidities significantly associated with death were chronic obstructive pulmonary disease (COPD; hazard ratio [HR]: 2.47; 95% confidence interval [CI]: 1.3; 4.7), atrial fibrillation (AF; HR: 2.41; 95% CI: 1.3; 4.3), and malignancy (HR: 1.9; 95% CI: 1.0; 3.6) at 3-year follow-up; whereas dementia (HR: 2.04; 95% CI: 1.3; 3.2), malignancy (HR: 1.84; 95% CI: 1.2; 2.8), and COPD (HR: 1.77; 95% CI: 1.1; 2.8) were the most associated with mortality at 5-year follow-up, after adjusting using Barthel functional index (BI). The two multimorbidity patterns most associated with death were AF, chronic kidney disease (CKD), and visual impairment (HR: 4.19; 95% CI: 2.2; 8.2) at 3-year follow-up as well as hypertension, CKD, and malignancy (HR: 3.24; 95% CI: 1.8; 5.8) at 5 years, after adjusting using BI. CONCLUSION: Multimorbidity as specific combinations of chronic conditions showed an effect on mortality, which would be higher than the risk attributable to individual morbidities. The most important predicting pattern for mortality was the combination of AF, CKD, and visual impairment after 3 years. These findings suggest that a new approach is required to target multimorbidity in octogenarians

Biosafety steps in the manufacturing process of spray-dried plasma: a review with emphasis on the use of ultraviolet irradiation as a redundant biosafety procedure

Spray dried plasma (SDP) is a functional protein source obtained from blood of healthy animals, approved by the veterinary authorities from animals declared to be fit for slaughter for human consumption. Blood of these animals is collected at the slaughterhouse, treated with an anticoagulant, chilled and transported to industrial facilities in which blood is centrifuged to separate the red blood cells from the plasma fraction. Plasma is then concentrated, and spray dried at high temperatures (80 °C throughout its substance) to convert it in a powder. Such method preserves the biological activity of its proteins, mainly albumins and globulins. SDP is mainly used in pig feed diets to significantly improve daily gain, feed intake, production efficiency, and to reduce post-weaning lag caused by the appearance of post-weaning diarrhea. Although SDP is considered a safe product and its manufacturing process consists of several biosafety steps, the security of the SDP is often questioned due to its nature as raw blood by-product, especially when emergent or re-emergent pathogens appear. This review provides an evaluation and validation of the different safety steps present in the manufacturing process of SDP, with special focus on a new redundant pathogen inactivation step, the UV-C irradiation, that may be implemented in the manufacturing process of the SDP. Overall results showed that the manufacturing process of SDP is safe and the UV-C radiation was effective in inactivating a wide range of bacteria and viruses spiked and naturally present in commercially collected liquid animal plasma and it can be implemented as a redundant biosafety step in the manufacturing process of the SDP.info:eu-repo/semantics/publishedVersio

Using lattice tools and unfolding methods for hpge detector efficiency simulation with the Monte Carlo code MCNP5

In environmental radioactivity measurements, High Purity Germanium (HPGe) detectors are commonly used due to their excellent resolution. Efficiency calibration of detectors is essential to determine activity of radionuclides. The Monte Carlo method has been proved to be a powerful tool to complement efficiency calculations. In aged detectors, efficiency is partially deteriorated due to the dead layer increasing and consequently, the active volume decreasing. The characterization of the radiation transport in the dead layer is essential for a realistic HPGe simulation. In this work, the MCNP5 code is used to calculate the detector efficiency. The F4MESH tally is used to determine the photon and electron fluence in the dead layer and the active volume. The energy deposited in the Ge has been analyzed using the *F8 tally. The F8 tally is used to obtain spectra and to calculate the detector efficiency. When the photon fluence and the energy deposition in the crystal are known, some unfolding methods can be used to estimate the activity of a given source. In this way, the efficiency is obtained and serves to verify the value obtained by other methods.Querol Vives, A.; Gallardo Bermell, S.; Ródenas Diago, J.; Verdú Martín, GJ. (2015). Using lattice tools and unfolding methods for hpge detector efficiency simulation with the Monte Carlo code MCNP5. Radiation Physics and Chemistry. 116:219-225. doi:10.1016/j.radphyschem.2015.01.027S21922511

Biosafety steps in the manufacturing process of spray-dried plasma : a review with emphasis on the use of ultraviolet irradiation as a redundant biosafety procedure

Ajuts: Secretaria de Universitats i Recerca del Departament d'Economia i Coneixement de la Generalitat de Catalunya 014 DI 066Spray dried plasma (SDP) is a functional protein source obtained from blood of healthy animals, approved by the veterinary authorities from animals declared to be fit for slaughter for human consumption. Blood of these animals is collected at the slaughterhouse, treated with an anticoagulant, chilled and transported to industrial facilities in which blood is centrifuged to separate the red blood cells from the plasma fraction. Plasma is then concentrated, and spray dried at high temperatures (80 °C throughout its substance) to convert it in a powder. Such method preserves the biological activity of its proteins, mainly albumins and globulins. SDP is mainly used in pig feed diets to significantly improve daily gain, feed intake, production efficiency, and to reduce post-weaning lag caused by the appearance of post-weaning diarrhea. Although SDP is considered a safe product and its manufacturing process consists of several biosafety steps, the security of the SDP is often questioned due to its nature as raw blood by-product, especially when emergent or re-emergent pathogens appear. This review provides an evaluation and validation of the different safety steps present in the manufacturing process of SDP, with special focus on a new redundant pathogen inactivation step, the UV-C irradiation, that may be implemented in the manufacturing process of the SDP. Overall results showed that the manufacturing process of SDP is safe and the UV-C radiation was effective in inactivating a wide range of bacteria and viruses spiked and naturally present in commercially collected liquid animal plasma and it can be implemented as a redundant biosafety step in the manufacturing process of the SDP

Age-dependent changes of nuclear morphology are uncoupled from longevity in Caenorhabditis elegans IGF/insulin receptor daf-2 mutants

Nuclear envelope (NE) architecture and aging have been associated since the discovery that certain human progeria diseases are due to perturbations in processing of lamin A protein, generating alterations in NE morphology. However, whether changes in the NE are a causal effect of normal and premature aging is still controversial. Caenorhabditis elegans is a model organism where observations supporting both, dependent and independent roles of nuclear architecture in the aging process, have been reported. We found that the long-lived glp-1 mutant and dietary restriction delayed age-associated nuclear morphology changes. In addition, we observed that the long-lived mutant of the insulin/IGF receptor daf-2 delayed the age-dependent changes of nuclear architecture at 25 °C, as previously described. However, when daf-2 animals were incubated at 20 °C they remained long-lived, but nuclear appearance changed at similar rate as in the wild type. This supports the idea that both phenotypes, longevity and maintenance of nuclear architecture are tightly associated but can be separated and argues that nuclear morphology deterioration is not a cause of the natural aging process.This work was funded by the Autonomous Government of Andalusia (P07-CVI- 02697). In addition, we wish to acknowledge Fundación Ramón Areces for a fellowship to ER. Some nematode strains used in this work were provided by the ‘‘Caenorhabditis Genetic Center’’, which is funded by the NIH National Center for Research Resources (NCRR).Peer Reviewe

Commercial feed containing porcine plasma spiked with African swine fever virus is not infective in pigs when administered for 14 consecutive days

The objective of this study was to determine if commercially collected liquid porcine plasma contaminated with African swine fever virus (ASFV) and fed for 14 consecutive days would infect pigs. Commercially collected liquid porcine plasma was mixed with the serum from an ASFV experimentally infected pig. To simulate the potential of pigs slaughtered being ASFV viremic but asymptomatic and passing antemortem inspection, the ratio of liquid plasma from healthy animals to serum from an ASFV infected pig used in this study represented 0.4% or 2.0% of the pigs slaughtered being viremic (Studies 1 or 2, respectively). The contaminated liquid plasma was mixed on commercial feed and pigs were fed for 14 consecutive days providing to each pig 104.3 or 105.0 TCID50 ASFV daily (Studies 1 or 2, respectively). Pigs were observed for an additional 5 or 9 days (Studies 1 or 2, respectively). In both experiments, the pigs did not become infected with ASFV during the 14d feeding period or during the subsequent observation period. In these experiments, unprocessed liquid plasma contaminated with ASFV mixed on commercial feed and fed for 14 consecutive days did not infect pigs. From our results we can conclude that the infectious dose of ASFV on feed is much higher than that previously reported, at least with ASFV-spiked raw plasma.info:eu-repo/semantics/publishedVersio