3D printed ventilation tubes and their effect on biological models.

BACKGROUND: Acute otitis media (AOM) causes inflammation and hearing loss. Ventilation tubes are key in treatment. 3D printing improves prostheses in otorhinolaryngology, offering precision and greater adaptability. MATERIALS AND METHODS: An experimental study was conducted with Wistar rats from July to December 2020. 3D tympanostomy tube models were designed, with technical specifications and tests performed on inexpensive 3D printers. The tympanostomy tube was inserted endoscopically. RESULTS: Procedures were performed on five rats with implants in both ears. Pre-intervention pathologies, such as atical retraction and glue ear, were found. The PLA-printed tympanostomy tube showed improvement after adjustments. Histopathological results revealed significant middle and inner ear damage. CONCLUSION: In our study, the design and 3D printing of implants fulfilled the desired functions when modified, with a height of 5 mm. Complications included PLA degradation and ear damage. There were no adverse events during observation, highlighting the need for further research on 3D-printed implants.

COVID-19 pandemic and its impact on medical interns' mental health of public and private hospitals in Guadalajara.

INTRODUCTION: Burnout syndrome is a global burden characterized by exhaustion, work detachment, and a sense of ineffectiveness. It affects millions of individuals worldwide, with a particularly high prevalence among medical students. Factors such as demanding education, exposure to suffering, and the COVID-19 pandemic have contributed to elevated stress levels. Addressing this issue is crucial due to its impact on well-being and health-care quality. MATERIALS AND METHODS: This cross-sectional survey study assessed fear of COVID-19 and burnout levels among medical student interns in hospitals in Guadalajara, Jalisco. The study used validated scales and collected data from September 2021 to September 2022. A snowball sampling method was employed and a minimum sample size of 198 participants was calculated. RESULTS: This study included 311 medical students (62.1% female and 37.9% male with a mean age of 23.51 ± 2.21 years). The majority were in their second semester of internship (60.5%) and from public hospitals (89.1%). Most students believed that the COVID-19 pandemic affected the quality of their internship (82.6%). Female students had higher personal burnout scores, while male students had higher work-related burnout scores. The mean score for fear of COVID-19 was 13.71 ± 6.28, with higher scores among women (p = 0.004) and those from public hospitals (p = 0.009). A positive weak correlation was found between COVID-19 scores and burnout subscales. CONCLUSION: Our study emphasizes the significant impact of various factors on burnout levels among medical students and health-care professionals during the COVID-19 pandemic. Prolonged exposure to COVID-19 patients, reduced staffing, and increased workload contributed to burnout, affecting well-being and quality of care. Targeted interventions and resilience-building strategies are needed to mitigate burnout and promote well-being in health-care settings.

Real-time karst groundwater monitoring and bacterial analysis as early warning strategies for drinking water supply contamination.

Karst aquifers have been globally exploited as a reliable source of drinking water but their intrinsic characteristics (concentrated recharge, high groundwater flow velocities, etc.) and the increase of anthropogenic pressures makes them highly vulnerable to pollution. Continuous monitoring of karst springs constitutes an effective approach for identifying episodic groundwater contamination and assuring safety conditions in drinking water supply systems. This study aims to improve groundwater protection insights through an integrated methodological approach based on real-time measurements of continuous water parameters coupled to bacterial analysis for the characterization of contamination events in a carbonate karst aquifer of a mountainous and rural area in S Spain. For this purpose, environmental, hydrodynamic and physico-chemical data in addition to bacterial activity (Escherichia coli) analysis were gathered from the analysis of eight flooding events at the two main outlets. In these karst springs, partially captured for drinking water supply, the recurrent turbid groundwater episodes suppose an important limitation for groundwater exploitation during several days, but also a concerning human health risk. The results revealed the different flow and sediment dynamics and mixing processes which determine the impact of faecal contamination derived from human activities on the karst groundwater drained by each spring. The described processes control the variable influence of allogenic recharge, which provokes notable differences regarding response times and maximum values of turbidity and associated bacterial activity in the investigated outlets. The outcomes of this work highlight the usefulness of the applied methodological framework to set the bases for an efficient implementation of early-warning strategies to prevent public health issues worldwide.

Carcass composition and physicochemical and sensory attributes of breast and leg meat from native Mexican guajolote (Meleagris g. gallopavo) as influenced by sex.

The aim of the study was to compare carcass composition and physicochemical and sensory attributes of breast and leg meat from native Mexican guajolote (Meleagris g. gallopavo) as influenced by sex. For this, slaughter weight and carcass characteristics of male (n=8) and female (n=8) guajolotes raised traditionally under extensive systems with similar housing and feeding conditions were recorded. Also, physical characteristics, proximate composition, the fatty acid profile, and sensory attributes were determined in breast and leg meat using standard procedures. The results showed that males had higher (P<0.001) slaughter weight, hot and cold carcass weights, and dressing percentage, as well as carcass part weights, while females had higher (P<0.001) abdominal fat weights than males. The lightness (L*), yellowness (b*), and drip loss values of breast meat, as well as redness (a*) and water-holding capacity values of leg meat, were significantly (P<0.05) influenced by sex. Male breast meat had higher (P<0.05) moisture content, crude protein, erucic acid (C22:1n9), ∑ MUFAs (total monounsaturated fatty acids), ∑ UFAs (unsaturated fatty acids), ∑ DFAs (desirable fatty acids), ∑ UFA / ∑ SFA (total saturated fatty acid) ratio, ∑ PUFA (total polyunsaturated fatty acid) / ∑ SFA ratio, and chewiness scores than females. Likewise, leg meat from males showed higher (P<0.05) ash content, myristic acid (C14:0), palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1n9c), palmitoleic acid (C16:1n7), ∑ SFAs, ∑ OFAs (odd fatty acids), thrombogenic index, and atherogenic index, whereas females had high fat content. In conclusion, it would be suggested that, from a nutritional point of view, the meat from male guajolotes was preferable to the meat from females.

Diagnostic Efficacy of Chest Computed Tomography with a Dual-Reviewer Approach in Patients Diagnosed with Pneumonia Secondary to Severe Acute Respiratory Syndrome Coronavirus 2.

To compare the diagnostic effectiveness of chest computed tomography (CT) utilizing a single- versus a dual-reviewer approach in patients with pneumonia secondary to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), we conducted a retrospective observational study of data from a cross-section of 4809 patients with probable SARS-CoV-2 from March to November 2020. All patients had a CT radiological report and reverse-transcription polymerase chain reaction (PCR) results. A dual-reviewer approach was applied to two groups while conducting a comparative examination of the data. Reviewer 1 reported 108 patients negative and 374 patients positive for coronavirus disease 2019 (COVID-19) in group A, and 266 negative and 142 positive in group B. Reviewer 2 reported 150 patients negative and 332 patients positive for COVID-19 in group A, and 277 negative and 131 positive in group B. The consensus result reported 87 patients negative and 395 positive for COVID-19 in group A and 274 negative and 134 positive in group B. These findings suggest that a dual-reviewer approach improves chest CT diagnosis compared to a conventional single-reviewer approach.

EFOMP policy statement 17: The role and competences of medical physicists and medical physics experts in the different stages of a medical device life cycle.

MPPs are trained in the branches of physics associated with the practice of medicine. Possessing a solid scientific background and technical skills, MPPs are well suited to play a leading role within each stage of a medical device life cycle. The various stages of the life cycle of a medical device include establishment of requirements with use-case assessment, investment planning, procurement of medical devices, acceptance testing especially regarding safety and performance, quality management, effective and safe use and maintenance, user training, interfacing with IT systems, and safe decommissioning and removal of the medical devices. Acting as an expert within the clinical staff of a healthcare organisation, the MPP can play an important role to achieve a balanced life cycle management of medical devices. Given that the functioning of medical devices and their clinical application in routine clinical practice and research is heavily physics and engineering based, the MPP is strongly associated with the hard science aspects and advanced clinical applications of medical devices and associated physical agents. Indeed, this is reflected in the mission statement of MPP professionals [1]. PURPOSE: The life cycle management of medical devices is described as well as the procedures involved. These procedures are performed by multi-disciplinary teams within a healthcare environment. The task of this workgroup was focused on clarifying and elaborating the role of the Medical Physicist and Medical Physics Expert - here collectively referred to as the Medical Physics Professional (MPP) - within these multi-disciplinary teams. This policy statement describes the role and competences of MPPs in every stage of a medical device life cycle. If MPPs are an integral part of these multi-disciplinary teams, the effective use, safety, and sustainability of the investment is likely to improve as well as the overall service quality delivered by the medical device during its life cycle. It leads to better health care quality and reduced costs. Furthermore, it gives MPPs a stronger position in health care organisations throughout Europe.

Superhydrophobic SLA 3D printed materials modified with nanoparticles biomimicking the hierarchical structure of a rice leaf.

The rice leaf, combining the surface properties of lotus leaves and shark skin, presents outstanding superhydrophobic properties motivating its biomimesis. We created a novel biomimetic rice-leaf superhydrophobic surface by a three-level hierarchical structure, using for a first time stereolithographic (SLA) 3D printed channels (100µm width) with an intrinsic roughness from the printing filaments (10µm), and coated with TiO2 nanoparticles (22 and 100nm). This structure presents a maximum advancing contact angle of 165° characterized by lower both anisotropy and hysteresis contact angles than other 3D printed surfaces, due to the presence of air pockets at the surface/water interface (Cassie-Baxter state). Dynamic water-drop tests show that the biomimetic surface presents self-cleaning, which is reduced under UV-A irradiation. The biomimetic surface further renders an increased floatability to 3D printed objects meaning a drag-reduction due to reduced water/solid contact area. Numerical simulations of a channel with a biomimetic wall confirm that the presence of air is essential to understand our results since it increases the average velocity and decreases the friction factor due to the presence of a wall-slip velocity. Our findings show that SLA 3D printing is an appropriate approach to develop biomimetic superhydrophobic surfaces for future applications in anti-fouling and drag-reduction devices.

Study of racial profile of the native Guajolote (Meleagris gallopavo gallopavo) in two regions of Mexico: morphometric characterization.

The present study aimed at the morphometric characterization of the native Guajolote reared in two regions of Mexico using multivariate analysis techniques. Data from a total of 362 unrelated native Guajolotes (257 males and 105 females) were used: of these, 160 were from the Central region and 202 were from the Southeast region. The birds were also grouped according to age, as youngs (≤ 8 months; n = 150) and adults (≥ 9 months; n = 212). The body weight (BW) and nine morphometric measurements-chest circumference (CC), body length (BL), body height (BH), neck length (NL), peak length (PL), shank length (SL), shank diameter (SD), wing length (WL) and wing width (WW)-were measured. There were significant differences (p < 0.05) due to the effect of region, sex and age for most of the morphometric measurements evaluated. There was a high percentage of positive and significant correlations (p < 0.001; p < 0.01) between the variables. In each region, three principal components were extracted that represented more than 75% of the accumulated variation among the variables. The most discriminating morphometric measurements between populations were WW, PL and NL. The Mahalanobis distance between the males and females of the two populations was 37.457 and 29.310 (p < 0.001), respectively. This differentiation can contribute to the definition of the phenotypic standard of this poultry genetic resource for its official recognition as a breed, as well as in the orientation of its genetic improvement programs in the future.

Uptake of infant and preschool immunisations in Scotland and England during the COVID-19 pandemic: An observational study of routinely collected data.

BACKGROUND: In 2020, the SARS-CoV-2 (COVID-19) pandemic and lockdown control measures threatened to disrupt routine childhood immunisation programmes with early reports suggesting uptake would fall. In response, public health bodies in Scotland and England collected national data for childhood immunisations on a weekly or monthly basis to allow for rapid analysis of trends. The aim of this study was to use these data to assess the impact of different phases of the pandemic on infant and preschool immunisation uptake rates. METHODS AND FINDINGS: We conducted an observational study using routinely collected data for the year prior to the pandemic (2019) and immediately before (22 January to March 2020), during (23 March to 26 July), and after (27 July to 4 October) the first UK "lockdown". Data were obtained for Scotland from the Public Health Scotland "COVID19 wider impacts on the health care system" dashboard and for England from ImmForm. Five vaccinations delivered at different ages were evaluated; 3 doses of "6-in-1" diphtheria, tetanus, pertussis, polio, Haemophilus influenzae type b, and hepatitis B vaccine (DTaP/IPV/Hib/HepB) and 2 doses of measles, mumps, and rubella (MMR) vaccine. This represented 439,754 invitations to be vaccinated in Scotland and 4.1 million for England. Uptake during the 2020 periods was compared to the previous year (2019) using binary logistic regression analysis. For Scotland, uptake within 4 weeks of a child becoming eligible by age was analysed along with geographical region and indices of deprivation. For Scotland and England, we assessed whether immunisations were up-to-date at approximately 6 months (all doses 6-in-1) and 16 to 18 months (first MMR) of age. We found that uptake within 4 weeks of eligibility in Scotland for all the 5 vaccines was higher during lockdown than in 2019. Differences ranged from 1.3% for first dose 6-in-1 vaccine (95.3 versus 94%, odds ratio [OR] compared to 2019 1.28, 95% confidence intervals [CIs] 1.18 to 1.39) to 14.3% for second MMR dose (66.1 versus 51.8%, OR compared to 2019 1.8, 95% CI 1.74 to 1.87). Significant increases in uptake were seen across all deprivation levels. In England, fewer children due to receive their immunisations during the lockdown period were up to date at 6 months (6-in-1) or 18 months (first dose MMR). The fall in percentage uptake ranged from 0.5% for first 6-in-1 (95.8 versus 96.3%, OR compared to 2019 0.89, 95% CI 0.86- to 0.91) to 2.1% for third 6-in-1 (86.6 versus 88.7%, OR compared to 2019 0.82, 95% CI 0.81 to 0.83). The use of routinely collected data used in this study was a limiting factor as detailed information on potential confounding factors were not available and we were unable to eliminate the possibility of seasonal trends in immunisation uptake. CONCLUSIONS: In this study, we observed that the national lockdown in Scotland was associated with an increase in timely childhood immunisation uptake; however, in England, uptake fell slightly. Reasons for the improved uptake in Scotland may include active measures taken to promote immunisation at local and national levels during this period and should be explored further. Promoting immunisation uptake and addressing potential vaccine hesitancy is particularly important given the ongoing pandemic and COVID-19 vaccination campaigns.

Resiliencia de la cobertura vegetal en el Suroeste de México ante los efectos del cambio climático / Resilience of vegetation cover in Southwest Mexico to the climate change effects

Resumen El modelado de escenarios de cambios climáticos utilizando sistemas de información geográfica para estimar la resiliencia de la cobertura vegetal es una herramienta útil para proyectar impactos futuros e implementar estrategias de conservación o manejo. En el presente trabajo asociamos espacialmente la biodiversidad de la cobertura vegetal del Suroeste de México con su capacidad para adaptarse a los efectos del cambio climático. Para analizar esta asociación se estimaron índices de riqueza y diversidad de especies, y su relación con escenarios de clima futuro. Se utilizaron los registros geográficos del Inventario Nacional Forestal y de Suelos para ocho comunidades vegetales (arbórea, arbustiva, herbácea, palma, cactus, bejucos, helechos y xerófita) distribuidas entre Guerrero, Oaxaca y Chiapas. La proyección climática fue al 2050, con modelos de circulación global A2 (promedio CCCMA, HADCM3 y CSIRO), 19 variables bioclimáticas y una resolución de 2.5 minutos. Los escenarios de cambio climático se modelaron con el algoritmo MaxEnt y la riqueza de especies, índice de diversidad y regresiones espaciales con el software Diva-GIS v7.5. Los modelos de regresión espacial estimaron que a mayor riqueza y diversidad de especies mayor seria la resiliencia que mostraría el ecosistema. Las comunidades vegetales cactus, palma y xerófita mostraron mayor vulnerabilidad al cambio climático. Las variaciones en la estacionalidad de la temperatura resultó ser el factor que condicionaría su distribución futura. Por lo que, las estrategias de conservación o manejo deberían considerar a la diversidad como un agente del ecosistema que amortiguaría a los efectos negativos del clima futuro.

Abstract The scenarios modeling of climate changes using geographic information systems to estimate the vegetation cover resilience is a useful tool to project future impacts and implement conservation or management strategies. We associate spatially the biodiversity of the vegetation cover of Southwest Mexico with its ability to adapt to the effects of climate change. We analysis this association estimating species richness and diversity indices, and its relationship with scenarios of future climate. Geographical records of the National Forest and Soil Inventory were obtained for eight plant communities (arboreal, shrubby, herbaceous, palm, cactus, vines, ferns, and xerophyte) distributed in Guerrero, Oaxaca, and Chiapas. The climatic projection was to 2050, with global circulation A2 models (CCCMA, HADCM3 and CSIRO average), 19 bioclimatic variables and a resolution of 2.5 minutes. Climate change scenarios were modelled with the MaxEnt algorithm and species richness, diversity index, and spatial regressions with Diva-GIS v7.5 software. The spatial regression models estimated that higher richness and species diversity, the greater resilience that the ecosystem would show. The cactus, palm, and xerophytic plant communities presented greater vulnerability to climate change. Variations in temperature seasonality turned out to be the factor that would condition its future distribution. Therefore, in conservation or management strategies, diversity should be considered as an agent of the ecosystem that cushions the negative effects of future climate.

Novel Template Plasmids pCyaA'-Kan and pCyaA'-Cam for Generation of Unmarked Chromosomal cyaA' Translational Fusion to T3SS Effectors in Salmonella.

The type III secretion systems (T3SS) encoded in pathogenicity islands SPI-1 and SPI-2 are key virulence factors of Salmonella. These systems translocate proteins known as effectors into eukaryotic cells during infection. To characterize the functionality of T3SS effectors, gene fusions to the CyaA' reporter of Bordetella pertussis are often used. CyaA' is a calmodulin-dependent adenylate cyclase that is only active within eukaryotic cells. Thus, the translocation of an effector fused to CyaA' can be evaluated by measuring cAMP levels in infected cells. Here, we report the construction of plasmids pCyaA'-Kan and pCyaA'-Cam, which contain the ORF encoding CyaA' adjacent to a cassette that confers resistance to kanamycin or chloramphenicol, respectively, flanked by Flp recombinase target (FRT) sites. A PCR product from pCyaA'-Kan or pCyaA'-Cam containing these genetic elements can be introduced into the bacterial chromosome to generate gene fusions by homologous recombination using the Red recombination system from bacteriophage λ. Subsequently, the resistance cassette can be removed by recombination between the FRT sites using the Flp recombinase. As a proof of concept, the plasmids pCyaA'-Kan and pCyaA'-Cam were used to generate unmarked chromosomal fusions of 10 T3SS effectors to CyaA' in S. Typhimurium. Each fusion protein was detected by Western blot using an anti-CyaA' monoclonal antibody when the corresponding mutant strain was grown under conditions that induce the expression of the native gene. In addition, T3SS-1-dependent secretion of fusion protein SipA-CyaA' during in vitro growth was verified by Western blot analysis of culture supernatants. Finally, efficient translocation of SipA-CyaA' into HeLa cells was evidenced by increased intracellular cAMP levels at different times of infection. Therefore, the plasmids pCyaA'-Kan and pCyaA'-Cam can be used to generate unmarked chromosomal cyaA' translational fusion to study regulated expression, secretion and translocation of Salmonella T3SS effectors into eukaryotic cells.

Co-occurrence Interaction Networks of Extremophile Species Living in a Copper Mining Tailing.

Copper mining tailings are characterized by high concentrations of heavy metals and an acidic pH, conditions that require an extreme adaptation for any organism. Currently, several bacterial species have been isolated and characterized from mining environments; however, very little is known about the structure of microbial communities and how their members interact with each other under the extreme conditions where they live. This work generates a co-occurrence network, representing the bacterial soil community from the Cauquenes copper tailing, which is the largest copper waste deposit worldwide. A representative sampling of six zones from the Cauquenes tailing was carried out to determine pH, heavy metal concentration, total DNA extraction, and subsequent assignment of Operational Taxonomic Units (OTUs). According to the elemental concentrations and pH, the six zones could be grouped into two sectors: (1) the "new tailing," characterized by neutral pH and low concentration of elements, and (2) the "old tailing," having extremely low pH (~3.5) and a high concentration of heavy metals (mainly copper). Even though the abundance and diversity of species were low in both sectors, the Pseudomonadaceae and Flavobacteriaceae families were over-represented. Additionally, the OTU identifications allowed us to identify a series of bacterial species with diverse biotechnological potentials, such as copper bioleaching and drought stress alleviation in plants. Using the OTU information as a template, we generated co-occurrence networks for the old and new tailings. The resulting models revealed a rearrangement between the interactions of members living in the old and new tailings, and highlighted conserved bacterial drivers as key nodes, with positive interactions in the network of the old tailings, compared to the new tailings. These results provide insights into the structure of the soil bacterial communities growing under extreme environmental conditions in mines.

Sobreexposición laboral a radiaciones ionizantes en el medio sanitario / Occupational overexposure to ionizing radiation in healthcare environment

Tras la comunicación por parte del Centro Nacional de Dosimetría (CND) de una potencial superación del límite de dosis de radiación en el dosímetro de anillo del trabajador de Medicina Nuclear que maneja radiofármacos, el Servicio de Prevención de Riesgos Laborales (SPRL) elabora un informe de investigación del incidente ocurrido, que se registra como accidente de trabajo. El Servicio de Radiofisica y Protección Radiológica (SRPR) también elabora un informe del incidente. Se observa que, debido a una avería en el fraccionador automático de radiofármacos, el trabajador ha realizado el fraccionamiento manualmente. El registro del dosímetro de anillo del trabajador da una lectura mensual estimada final de 505,3 mSv, que supera los límites anuales de dosis equivalente para extremidades. El SPRL, además realiza una vigilancia de la salud especial del trabajador, establece un apto con limitaciones durante un año y adapta el puesto de trabajo con restricción de tareas y con seguimientos periódicos. Se aplican las medidas preventivas pertinentes de organización y seguridad

Following the communication by the National Dosimetry Center (CND) of a potential exceeding the radiation dose limit in the ring dosimeter of the Nuclear Medicine worker who handles radiopharmaceuticals, the Health and Safety Occupational Service prepares a research report of the incident occurred, which is recorded as an occupational accident. The Radiophysical and Radiation Protection Service also prepares an incident report. It shows that, due to a breakdown in the automatic radiopharmaceutical fractionator, the worker performs it manually. The worker's ring dosimeter record gives a final estimated monthly reading of 505.3 mSv, which exceeds the annual equivalent dose limits for limbs. The Health and Safety Occupational Service performs a special health surveillance of the worker, establishes an apt with limitations for one year and adapts the job position with restriction of tasks and with periodic follow-ups. The relevant preventive measures of organization and safety are applied

Complete Genome Sequences of Five Salmonella enterica Phages, NBSal001, NBSal002, NBSal003, NBSal004, and NBSal005.

Salmonella enterica is a Gram-negative bacterium, recognized as one of the most important foodborne pathogens in the world. Bacteriophages represent a promising alternative to the biocontrol of Salmonella Here, we report the isolation of five Salmonella bacteriophages, the sequencing of their full genomes, and initial genomic characterization.

Comparison of four nonlinear growth models in Creole chickens of Mexico.

Animal growth is a complex and dynamic process that involves physiological and morphological changes from hatching to maturity. It is defined as the increase in body size per time unit. Mathematical functions, called growth models, have been used to explain growth patterns. The aim of this study was to compare the Gompertz-Laird, logistic, Richards, and Von Bertalanffy growth models to determine which best fits the data of the Creole chickens (CC). Three hundred forty-seven CC were individually weighed from hatching until 177 D of age. Birds were fed a starter diet (0-18 D of age; 19% crude protein (CP) and 3,000 kcal of ME/kg) and grower diet (19-177 D of age; 18% CP and 2,800 kcal of ME/kg). Data were analyzed using PROC NLIN to fit the nonlinear growth curve. The coefficient of determination (R2), Akaike information criteria (AIC), and Bayesian information criteria (BIC) were used to compare the goodness of fit of the models. The Von Bertalanffy (R2: 0.9382, 0.9415; AIC: 2,224.1, 2,424.8; BIC: 2,233.5, 2,434.3, for females and males, respectively) was the model that best explained growth of the birds. On the other hand, both the Gompertz-Laird and logistic models overestimated hatching BW and underestimated the final BW of CC. Females reached age of maximum growth faster than males. The asymptotic weight was higher in males (3,011 g) than in females (2,011 g). Body weight at inflection point was 892 g at 64 D of age for males and 596 g at 54 D for females. In conclusion, the best fit of the data was obtained with the Von Bertalanffy growth model; the information is intended to serve as the basis for utilizing CC.

Soybean meal substitution by dehulled lupine (Lupinus angustifolius) with enzymes in broiler diets.

OBJECTIVE: Evaluate the effects of i) dehulling of lupine seed on chemical composition and apparent metabolizable energy (AME) and ii) soybean meal substitution by dehulled lupine seed in broiler diets with enzymes on productive performance, size of digestive organs and welfare-related variables. METHODS: Experiment 1, chemical composition and AME were determined in whole and dehulled lupine seed. Experiment 2, two hundred eighty-eight one-day-old male Ross 308 broilers were used. The experimental diets were maize-soybean meal (MS), MS with enzymes (MSE) and maize-dehulled lupine seed with enzymes (MLE). Diets were assigned to the experimental units under a completely randomized design (eight replicates per diet). The body weight (BW) gain, feed intake, feed conversion, digestive organ weights, gait score, latency to lie down and valgus/varus angulation were evaluated. RESULTS: The dehulling process increased protein (25.0% to 31.1%), AME (5.9 to 8.8 MJ/kg) and amino acid contents. The BW gain of broilers fed the MLE diet was similar (p>0.05) to that of those fed the MS diet, but lower than that of those fed the MSE diet. Feed intake of broilers fed the MLE diet was higher (p<0.05) than that of those fed the MS diet and similar (p>0.05) to those fed the MSE diet. Feed conversion of broilers fed the MLE diet was 8.0% and 8.7% higher (p<0.05) than that of those fed the MS and MSE diets, respectively. Broilers fed the MLE diet had the highest (p<0.05) relative proventriculus and gizzard weights, but had poor welfare-related variables. CONCLUSION: It is possible to substitute soybean meal by dehulled lupine seed with enzymes in broiler diets, obtaining similar BW gains in broilers fed the MLE and MS diets; however, a higher feed intake is required. Additionally, the MLE diet reduced welfare-related variables.

Fnr and ArcA Regulate Lipid A Hydroxylation in Salmonella Enteritidis by Controlling lpxO Expression in Response to Oxygen Availability.

Lipid A is the bioactive component of lipopolysaccharide, and presents a dynamic structure that undergoes modifications in response to environmental signals. Many of these structural modifications influence Salmonella virulence. This is the case of lipid A hydroxylation, a modification catalyzed by the dioxygenase LpxO. Although it has been established that oxygen is required for lipid A hydroxylation acting as substrate of LpxO in Salmonella, an additional regulatory role for oxygen in lpxO expression has not been described. The existence of this regulation could be relevant considering that Salmonella faces low oxygen tension during infection. This condition leads to an adaptive response by changing the expression of numerous genes, and transcription factors Fnr and ArcA are major regulators of this process. In this work, we describe for the first time that lipid A hydroxylation and lpxO expression are modulated by oxygen availability in Salmonella enterica serovar Enteritidis (S. Enteritidis). Biochemical and genetic analyses indicate that this process is regulated by Fnr and ArcA controlling the expression of lpxO. In addition, according to our results, this regulation occurs by direct binding of both transcription factors to specific elements present in the lpxO promoter region. Altogether, our observations revealed a novel role for oxygen acting as an environment signal controlling lipid A hydroxylation in S. Enteritidis.

A collapsed-cone based transit EPID dosimetry method.

PURPOSE: To develop a transit-dose portal dosimetry method based on a commercial collapsed-cone algorithm. METHODS: A Varian Clinac21EX (Varian Medical Systems, USA), equipped with an amorphous-silicon EPID aS1000, was used. Dose calculations were performed with the collapsed-cone algorithm of Pinnacle3 v8.0 m (Philips Medical Systems, USA). A model for the energy of 6 MV was made in Pinnacle3 and afterwards validated for clinical use. A virtual phantom with different densities was contoured and superimposed on the patient images, simulating the presence of the EPID during the treatment. Corrections for photon spectral variations were introduced using Matlab (Mathworks, USA). Transit dosimetry was verified with an anthropomorphic phantom, on which different treatment fields were simulated in locations of skull, thorax and pelvis. In addition, a prostate treatment with IMRT was administered thereon. Dose distributions were compared with gamma index. RESULTS: The dose differences at the central point did not exceed 2%, except for the 20 x 20 cm2 field size centered in the skull. The model presented in this work, assumes that the dimensions of the solid water phantom, are infinite, except for the thickness. The mean values for the gamma index pass rates were 85.62% for (3%, 3 mm), 91.73% (4%, 3 mm) and 95.68% (5%, 3 mm). CONCLUSIONS: The value of 95% for γ (5%, 3 mm) can be established as the value below which the origin of the discrepancies should be investigated. It should be considered that the proposed method is complementary and not a substitute for pre-treatment dosimetry.