Feasibility Study of a Proton Irradiation Facility for Radiobiological Measurements at an 18 MeV Cyclotron

A feasibility study of an experimental setup for the irradiation of biological samples at the cyclotron facility installed at the National Centre of Accelerators (Seville, Spain) is presented. This cyclotron, which counts on an external beam line for interdisciplinary research purposes, produces an 18 MeV proton beam, which is suitable for the irradiation of mono-layer cultures for the measurement of proton cell damages and Relative Biological Effectiveness (RBE) at energies below the beam nominal value. Measurements of this kind are of interest for proton therapy, since the variation of proton RBE at the distal edge of the Bragg curve may have implications in clinical proton therapy treatments. In the following, the characteristics of the beam line and the solutions implemented for the irradiation of biological samples are described. When dealing with the irradiation of cell cultures, low beam intensities and broad homogeneous irradiation fields are required, in order to assure that all the cells receive the same dose with a suitable dose rate. At the cyclotron, these constraints have been achieved by completely defocusing the beam, intercepting the beam path with tungsten scattering foils and varying the exit-window-to-sample distance. The properties of the proton beam thus obtained have been analysed and compared with Monte Carlo simulations. The results of this comparison, as well as the experimental measurement of the lateral dose profiles expected at the position of samples are presented. Meaningful dose rates of about 2–3 Gy/min have been obtained. Homogeneous lateral dose profiles, with maximum deviations of 5%, have been measured at a distance of approximately 50 cm in air from the exit window, placing a tungsten scattering foil of 200 μm in the beam path

Novel dual single sided silicon strip detector chip for radiotherapy verification

A novel dual single sided silicon strip detector (SSSSD) chip was designed to meet clinical requirements in radiotherapy verification. An available design from Micron Semiconductor Ltd. (BB7, 500 µ m thick) was the base of a two-dimensional detector adapted into a special configuration with the aim of uniforming and minimizing foreing materials around the active area (64 × 64 mm2). With this purpose, two independent BB7 SSSSDs were mounted in a perpendicular configuration, separated by a 500 µ m kapton dielectric film with the same dimensions as the silicon wafers, thus minimizing air gaps in between. This new configuration, called the dual SSSSD chip design, was mounted on kapton printed circuit board (PCB). Both silicon wafers were divided into 32 strips, 2 mm width each. The aim of developing this detector was to allow 2D dose measurements, improve spatial resolution and perform radiotherapy treatment verification faster than with a previous prototype. Characteristics and performance of the novel detector are presented

Motivating pregnant and breastfeeding women in Spain to avoid persistent toxic substances in their diet

The objective of this study was to explore what motivates pregnant and breastfeeding women to make changes in their diet, specifically to examine how their perceptions regarding diet facilitate or act as obstacles to introducing healthy eating habits. For the optimal development of the mother, the fetus, or breastfeeding baby, it is important to avoid foods containing substances, such as persistent toxic substances (PTSs), that are harmful to health during pregnancy and after the baby's birth. This study used a qualitative research methodology, based on semi-structured individual interviews, food diaries, free lists, and focus groups with 111 pregnant and breastfeeding women in Spain. This approach was followed by a systematic and exhaustive exploitation of the qualitative data obtained, following the methodological principles of grounded theory. From the study results, we conclude that the motivation for a change in diet to avoid PTSs is based on the desire to promote good health, beliefs about the importance of having a varied diet, and the avoidance of potential risks. The main obstacles to change can be attributed to inadequate information, contradictory discourses, and socioeconomic diffculties

Etiology and Viral Genotype in Patients with End-Stage Liver Diseases admitted to a Hepatology Unit in Colombia

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are the principal risk factor associated to end-stage liver diseases in the world. A study was carried out on end-stage liver disease cases admitted to an important hepatology unit in Medellin, the second largest city in Colombia. From 131 patients recruited in this prospective study, 71% of cases were diagnosed as cirrhosis, 12.2% as HCC, and 16.8% as cirrhosis and HCC. Regarding the risk factors of these patients, alcohol consumption was the most frequent (37.4%), followed by viral etiology (17.6%). Blood and/or hepatic tissue samples from patients with serological markers for HCV or HBV infection were characterized; on the basis of the phylogenetic analysis of HCV 5′ UTR and HBV S gene, isolates belonged to HCV/1 and HBV/F3, respectively. These results confirm the presence of strains associated with poor clinical outcome, in patients with liver disease in Colombia; additionally, HBV basal core promoter double mutant was identified in HCC cases. Here we show the first study of cirrhosis and/or HCC in Colombian and HBV and HCV molecular characterization of these patients. Viral aetiology was not the main risk factor in this cohort but alcohol consumption

Genetic Susceptibility and Viral Clearance of Hepatitis C Virus infection

The hepatitis C virus (HCV) is still one of the leading causes of chronic hepatitis in the western world. Between 15% to 40% of the people acutely infected achieve spontaneous resolution, even though the variables and factors related to the viral clearance are not yet fully established. The study of the physiopathological mechanisms of the HCV is essential for the identification of the factors related either to spontaneous resolution or persistence of the viral infection. Some studies have found out variables from the host associated with this outcome, including the interleukin 28 (IL-28B) gene polymorphisms. This gene codifies the lambda 3 interferon (IFNL3). The purpose of this article is to perform a literature review of the physiopathology of HCV infection, describe the evidence of the role of the IL28 gene polymorphisms, and their impact in the spontaneous virus clearance and other aspects of the natural history and treatment of the viral infection

Endoscopic and Surgical Removal of Gastrointestinal Foreign Bodies in Dogs: An Analysis of 72 Cases

In emergency veterinary practice, gastrointestinal foreign body (GFB) removal is a common procedure that is performed with different techniques, such as endoscopy or surgery. The aims of this retrospective, multicentre, clinical study were to report the common locations and types of objects recovered and to investigate clinical factors and outcomes in dogs after surgical or endoscopic treatment for GFB removal. Records of dogs with a GFB diagnosis referred to the Teaching Veterinary Hospital or treated in three different veterinary hospitals from September 2017 to September 2019 were examined. The data obtained from each case included breed, age, clinical signs at presentation, duration of clinical signs, type and location of the GFB, treatment, length of hospitalisation and outcome. Seventy-two dogs were enrolled in the study. There were 42 males (58%) and 30 females (42%). The median age was 36 months (range: 3 months to 8 years). Endoscopic retrieval was performed in 56% of GFBs (located in the stomach or duodenum), whereas 44% of dogs underwent surgery. The type of FB detected varied greatly: kid toy (14%), metallic object/coin (13%), cloth (13%), sock (8%), ball (8%), plastic material (8%), peach stone (7%), fishhook (6%), sewing needle (4%), hair tie (4%), pacifier (3%), plant materials (3%) and others (9%). Moreover, the FBs were classified as sharp (13%, n = 9), pointed (33%, n = 24), blunt (26%, n = 19), or linear (28%, n = 20). In this study, 68% of FBs were localised in the stomach, 25% in the intestinal tract (50% duodenum, 28% jejunum, and 22% ileum), and 7% in both the stomach and small intestine. The type of GFB was not significantly associated with age, site or breed. There was a significant association between the type of GFB and sex: if the dog was male, there was a 38% probability of ingesting linear GFBs. The dog survival rate was 100% in cases treated by gastric endoscopic or surgical removal, 94% in cases treated with enterotomy and 33% in cases in which enterectomy was necessary. Enterectomy and multiple surgical sites were associated with a poor outcome. The presence of vomiting for more than 24 h was significantly associated with death

Analysis of biophysical variables in an onion crop (Allium cepa L.) with nitrogen fertilization by sentinel-2 observations

The production of onions bulbs (Allium cepa L.) requires a high amount of nitrogen. Ac cording to the demand of sustainable agriculture, the information-development and communication technologies allow for improving the efficiency of nitrogen fertilization. In the south of the province of Buenos Aires, Argentina, between 8000 and 10,000 hectares per year−1 are cultivated in the districts of Villarino and Patagones. This work aimed to analyze the relationship of biophysical variables: leaf area index (LAI), canopy chlorophyll content (CCC), and canopy cover factor (fCOVER), with the nitrogen fertilization of an intermediate cycle onion crop and its effects on yield. A field trial study with different doses of granulated urea and granulated urea was carried out, where biophysical char acteristics were evaluated in the field and in Sentinel-2 satellite observations. Field data correlated well with satellite data, with an R2 of 0.91, 0.96, and 0.85 for LAI, fCOVER, and CCC, respectively. The application of nitrogen in all its doses produced significantly higher yields than the control. The LAI and CCC variables had a positive correlation with yield in the months of November and December. A significant difference was observed between U250 (62 Mg ha−1) and the other treatments. The U500 dose led to a yield increase of 27% compared to U250, while the difference between U750 and U500 was 6%.Fil: Casella, Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Clima y Agua; ArgentinaFil: Orden, Luciano. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; Argentina. Universidad Miguel Hernández. Centro de Investigación e Innovación Agroalimentaria y Agroambiental. GIAAMA Reseach Group; EspañaFil: Pezzola, Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; ArgentinaFil: Bellaccomo, Maria Carolina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; ArgentinaFil: Winschel, Cristina Ines. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; ArgentinaFil: Caballero, Gabriel. Technological University of Uruguay. Departamento de Montevideo, UruguayFil: Delegido, Jesús. Universidad de Valencia. Image Processing Laboratory (IPL); EspañaFil: Navas Gracia, Luis Manuel. Universidad de Valladolid. Departamento de Ingenieria Agrícola y Forestal; EspañaFil: Verrelst, Jochem. Universidad de Valencia. Image Processing Laboratory (IPL); Españ

Dosimetric response of radiochromic films to protons of low energies in the Bragg peak region

One of the major advantages of proton or ion beams, applied in cancer treatment, is their excellent depth-dose profile exhibiting a low dose in the entrance channel and a distinct dose maximum (Bragg peak) near the end of range in tissue. In the region of the Bragg peak, where the protons or ions are almost stopped, experimental studies with low-energy particle beams and thin biological samples may contribute valuable information on the biological effectiveness in the stopping region. Such experiments, however, require beam optimization and special dosimetry techniques for determining the absolute dose and dose homogeneity for very thin biological samples. At the National Centre of Accelerators in Seville, one of the beam lines at the 3 MV Tandem Accelerator was equipped with a scattering device, a special parallel-plate ionization chamber with very thin electrode foils and target holders for cell cultures. In this work, we present the calibration in absolute dose of EBT3 films [Gafchromic radiotherapy films, http://www.ashland.com/products/gafchromic-radiotherapy-films] for proton energies in the region of the Bragg peak, where the linear energy transfer increases and becomes more significant for radiobiology studies, as well as the response of the EBT3 films for different proton energy values. To irradiate the films in the Bragg peak region, the energy of the beam was degraded passively, by interposing Mylar foils of variable thickness to place the Bragg peak inside the active layer of the film. The results obtained for the beam degraded in Mylar foils are compared with the dose calculated by means of the measurement of the beam fluence with an ionization chamber and the energy loss predicted by srim2008 code.EU Initial Training Marie Curie Network FP7-PEOPLE-2011-ITN-289485Spanish Research Projects No. FPA2014-53290-C2-2-PSpanish Research Projects No. FPA2013-47327-C2-1-RAndalusian Research Project No. P12-FQM-160

Short–term effects of air pollution and noise on emergency hospital admissions in Madrid and economic assessment

The aim of this study was to study the effect of air pollution and noise has on the population in Madrid Community (MAR) in the period 2013–2018, and its economic impact