Maximum Exposure Time Research Articles

Green Veterinary Pharmacology for Honey Bee Welfare and Health: Origanum heracleoticum L. (Lamiaceae) Essential Oil for the Control of the Apis mellifera Varroatosis.

Varroatosis, caused by the Varroa destructor mite, is currently the most dangerous parasitic disease threatening the survival of honey bees worldwide. Its adverse effect on the welfare and health of honey bees requires the regular use of specific acaricides. This condition has led to a growing development of resistance phenomena towards the most frequently used drugs. In addition, another important aspect that should not be understated, is the toxicity and persistence of chemicals in the environment. Therefore, the identification of viable and environmentally friendly alternatives is urgently needed. In this scenario, essential oils are promising candidates. The aim of this study was to assess the contact toxicity, the fumigation efficacy and the repellent effect of Origanum heracleoticum L. essential oil (EO) against V. destructor mite. In the contact tests, each experimental replicate consisted of 15 viable adult female mites divided as follows: 5 treated with EO diluted in HPLC grade acetone, 5 treated with acetone alone (as negative control) and 5 treated with Amitraz diluted in acetone (as positive control). The EO was tested at concentrations of 0.125, 0.25, 0.5, 1 and 2 mg/mL. For each experimental replicate, mortality was manually assessed after one hour. The efficacy of EO fumigation was evaluated through prolonged exposure at different time intervals. After each exposure, the 5 mites constituting an experimental replicate were transferred to a Petri dish containing a honey bee larva and mortality was assessed after 48 h. The repellent action was investigated by implementing a directional choice test in a mandatory route. During the repellency tests the behavior of the mite (90 min after its introduction in the mandatory route) was not influenced by the EO. In contact tests, EO showed the best efficacy at 2 and 1 mg/mL concentrations, neutralizing (dead + inactivated) 90.9% and 80% of the mites, respectively. In fumigation tests, the mean mortality rate of V. destructor at maximum exposure time (90 min) was 60% and 84% at 24 and 48 h, respectively. Overall, these results demonstrate a significant efficacy of O. heracleoticum EO against V. destructor, suggesting a possible alternative use in the control of varroatosis in honey bee farms in order to improve Apis mellifera welfare and health and, consequently, the hive productions.

Heat transfer model for predicting hen’s core temperature

The objective of this study was to develop a heat balance in laying hens and analyze their performance, besides simulating the partition between sensible and latent heats. The 28-d old Hy-line laying hens were subjected to a factorial combination of five levels of air temperature (20, 24, 28, 32, and 36 °C), two levels of air relative humidity (40 and 60%), and three levels of air velocity (0.2, 0.7 and 1.4 m∙s−1). The minimum and maximum exposure times for each bird to a given thermal challenge were 3 h and 6 h, respectively. Firstly, ANOVA and multiple regression were performed to fit equations of respiratory rate and the overall heat transfer coefficient by conduction in the bird's body (U), respectively. For the heat balance, the partitions of heat transferred to the bird’s body through conduction, convection, radiation and respiratory tract were taken into account. Different input settings were evaluated for convection heat transfer coefficient (hconv) and U. The validation of the proposed model was performed by comparing the predicted cloacal temperature values to those obtained experimentally. As a result, the model proved to be adequate for analyzing the interaction between hen and environment, and the complexity in determining U and hconv interferes in its performance. Statistical analysis reiterates that the use of constant values for these coefficients are not recommended. For the studied conditions, latent heat loss had a greater contribution than sensible forms from the temperature of 32.85 °C, not being influenced by air velocity. The model is accurate for the prediction of cloacal temperature, contributing to the identification of possible strategies for mitigating thermal stress, as it allows simulations of the thermoregulation mechanism of laying hens.

Does emotional valence modulate word recognition? A behavioral study manipulating frequency and arousal

Effects of emotional valence have been observed in lexical decision tasks, suggesting that valence information modulates early word recognition. However, is still unclear the processing advantage of the different valence categories, and how these advantages might be modulated by word frequency and arousal. To clarify this question, a lexical decision task was designed using emotional words as stimuli. Emotional words were divided into three categories: 60 positive, 60 negative, and 60 neutral words. Word frequency was manipulated into low and high conditions and arousal was controlled among experimental conditions (word valence and frequency). In the first experiment, 54 participants performed the task with a maximum stimuli exposure time of 2000 ms. In a follow-up experiment, 42 participants performed the same task with two shorter fixed time exposures (150 ms and 300 ms). The results were similar between experiments: positive words were recognized faster and negative words were recognized slower than neutral ones. Furthermore, this valence effect was modulated by word frequency, affecting only words that take longer to be recognized (low-frequency words). However, the valence by frequency interaction was attenuated for high-arousal words when the pressure to respond was high (short exposure time - 150 ms). Overall, the results confirm that the emotional status of a word can affect word processing at early stages when automatic processes are taking place.

Dose conversion coefficients to marine biota due to natural radionuclides in an oil spill accident using Monte Carlo simulation

The crude oil that reached the Brazilian coast in 2019 was the most significant environmental disaster ever recorded in Brazilian marine waters, with severe ecological and economic repercussions not fully dimensioned and understood. One consequence of this kind of oil spill is the absorbed dose delivered to marine organisms. The biota exposure to radiation can introduce consequences that range from fertility decrease to death of exposed population. Therefore, the current study aims to use the ICRP reference organisms (flatfish, crab, and brown seaweed) to assess marine biota exposure due to uranium and thorium series radiation. The oil spill scenario, as well as the reference biota, were simulated in MCNP. Thorium series stood out for presenting a significant contribution to the dose. Furthermore, it was noticed that a remedial action capable of removing Tl-208 would significantly decrease the effects of radiation on marine biota. Finally, dose conversion coefficients for both uranium and thorium series were obtained as oil activity concentration functions. The results obtained here can be used in an oil spill event along with other worldwide recognized models. In addition, the dose coefficients can be used strategically to assess the maximum exposure time for emergency oil control, removal, and mitigation.

Self-compacting concrete between workability performance and engineering properties using natural stone wastes

The current work aims at studying the chemical and mineralogical composition in addition to the physical properties of natural stone wastes as cement replacement and their effect on the fresh and hardened properties of self-compacting concretes (SCC). In the present study, two types of natural stone wastes were used: carbonaceous stone wastes (C) and siliceous stone wastes (S). The chemical, mineralogical, and physical characterization of the different wastes were performed using X-ray fluorescence (XRF), X-ray diffraction (XRD), water pycnometer, and Specific surface area.Nine SCC mixes coded (Ref., C10, 20, 30, 40% - S10, 20, 30, 40%) were formulated by incorporating four proportions of each type of the stone wastes other than the reference mix. The initial and final setting times, fresh density, air content, flowing - ability by slump flow, filling ability by T500 and V-funnel time, passing ability by L-box, U-box, and block assessment by J-ring were measured for the fresh mixes. For the hardened mixes, the water absorption, density, voids, compressive, flexure, and splitting tensile strengths were tested, in addition to their resistances against water penetration and chloride ion penetration, as well as sulfuric acid attack.The results revealed a slight to noticeable enhancement in the workability performance of SCCs with increasing stone wastes proportions. Using up to 40% stone wastes led to an increase in the flow- and passing-abilities by not less than (1.45%, 4.88%), while decreasing in the filling times by not less than (7.14%, 30%) as compared to the reference mix with a slight sign of bleeding and lacking an evidence of segregation or blocking.Using up to 10% stone wastes has an insignificant drop in the water absorption and density, compressive, flexure, and splitting tensile strengths values by not more than (1.64%, 0.42%, 3.65%, 3.88%, 10.51%), respectively at late age. A better resistance toward the sulphuric acid attack, in terms of strength and mass loss, was noticed for all replacement levels by not less than (17%, 13%), respectively at maximum exposure time, as compared to the reference mix.

Behaviour of 54.4SiO2-13.7Na2O-1.7K2O-5.0CaO-12.4MgO-0.6Y2O3-11.3Al2O3-0.9B2O3 HT-SOFC glass sealant under oxidising and reducing atmospheres

The behaviour of the promising glass sealant 54.4SiO2-13.7Na2O-1.7K2O-5.0CaO-12.4MgO-0.6Y2O3-11.3Al2O3-0.9B2O3 for solid oxide fuel cells (SOFCs) under SOFC operating conditions was studied. First, the kinetics of the crystallisation processes at the operating temperature (850 °C) was discussed (maximum exposure time of 1000 h), and the effect of crystallisation on the coefficient of thermal expansion (CTE) of the sealant was studied. Furthermore, the degradation processes at the interface of the glass sealant and functional SOFC materials (Crofer 22 APU, YSZ, and NiO(Ni)-YSZ) during exposure to 850 °C in oxidising and reducing atmospheres for 500 h were studied. The tests demonstrated good performance of the sealant studied and possibility of its application in SOFCs.

Time-Dependent Gas Permeability of Class C Fly Ash Concrete and Correlation with Its Microstructural Parameters

Based on the field tests of fly ash concrete with a maximum exposure time of 840 days, the effects of fly ash content and exposure time on gas permeability of concrete were studied. A time-dependent gas permeability coefficient model considering the influence of fly ash content was established. The pore structure parameters of fly ash concrete with different exposure times were measured by the nuclear magnetic resonance (NMR) method. In addition, the time-dependent relationship between microstructural parameters and gas permeability coefficient was discussed. Results show that adding 20%–40% fly ash into concrete can effectively reduce the gas permeability and improve its microstructural features after exposure of 360 days; concrete with 30% fly ash has the minimum critical pore size and average pore size, which have the most significant effect on reducing the gas permeability. With prolonged exposure times, fly ash concrete can increase (decrease effectively) the proportion of pore diameter of 10–50 nm (100–500 nm). Total porosity and critical pore diameter can better characterize the time-dependent gas permeability.

Ozonation of Bovine Peritoneal Membrane for Preservation: Preliminary Investigation

ABSTRACT A dynamic fluid system using ozonated water flowing over the bovine peritoneal membrane was developed. Histological analyses were performed to verify the maximum time of ozone exposure to maintain the viability of the biological material. The results indicate that the biological viability of the peritoneum tissue was impaired after 15 minutes of exposure (5.5 mg O3 (cm2)−1) to ozonated water in a dynamic condition. Thus, this biological sample can be submitted to the dynamic fluid system with ozonated water for 10 minutes at an applied ozone dose of 3.7 mg O3 (cm2)−1, without inducing significant changes to the tissue.

Hand-Arm Vibration Controls for Jackleg Rock Drills: A Pilot Study Assessing Ergonomic Hazards.

Jackleg drill operators are exposed to harmful levels of hand-arm vibration (HAV). Anti-vibration handles and gloves provide modest reductions in HAV exposures and forearm muscle exertion from the use of AV handles and gloves by jackleg drill operators. The goal of this pilot study was to investigate changes in HAV with the use of anti-vibration gloves and handles compared to forearm muscle exertion experienced by operators and measured with surface electromyography (EMG). Five subjects operated the drill under four different cases: no anti-vibration controls, anti-vibration gloves only, anti-vibration handle only, and simultaneous anti-vibration handle and glove use. Muscle exertion was expressed as a percent of maximum voluntary contraction (%MVC) and was compared using Welch's ANOVA with Games-Howell post-hoc comparisons. The case with both anti-vibration controls in use simultaneously (largest grip diameter) was associated with a mean %MVC of 36.13% during operation for all forearm muscles combined, which was significantly higher than the other cases (p < 0.05). There were no statistically significant differences in mean HAV exposures. The anti-vibration handle with anti-vibration glove case only increased the maximum allowable exposure time by eight minutes as compared to the control case without any anti-vibration controls. These results suggest that the modest HAV exposure reductions from the use of anti-vibration handles and gloves may pale in comparison to the increased muscle exertion resulting from their use, and this tradeoff among jackleg drill operators is a potential concern that warrants further investigation.

Predicting the spatiotemporal exposure of aquatic species to intrusions of fire retardant in streams with limited data

Because fire retardant can enter streams and harm aquatic species including endangered fish, agencies such as the U.S. Forest Service (USFS) must estimate the downstream extent of toxic effects every time fire retardant enters streams (denoted as an “intrusion”). A challenge in estimating the length of stream affected by the intrusion and the exposure time of species in the affected reach is the lack of data typically available on the stream's geometry and flow characteristics. Previously, the USFS estimated the affected reach length assuming instantaneous mixing of the retardant over the reach; however, this approach neglects key river mixing processes. An approach is described that accounts for advection and dispersion of the retardant as well as the downstream growth of the stream. Applied to 13 intrusions documented by the USFS, the new approach shows affected reach lengths range between 8.0 and 362 km; all 13 cases exceeded previous estimates from an instantaneous mixing model. The time that a stationary individual in the affected reach is exposed to concentrations above a pre-defined toxicity threshold (10% of 96-hour LC50, for example) ranges from 0.17 to 2.73 h, with all but one case having a maximum exposure time less than 1.5 h. Results from 1152 hypothetical intrusions provided by the USFS confirm that exposure times rarely exceed 5 h. This result suggests that 96-hour tests to determine toxicity (LC50) to various species should be reconsidered. Although the approach described can be improved in several ways, it provides a first estimate of the effects of fire retardant intrusions.

Biochemical Analysis of the Differential Tissue Expression of Heat Shock Protein70 Following Exposure to Electromagnetic

Low field electromagnetic radiation that is emitted from cell phones may induce morphological aberrations and change in gene expression of heat shock protein 70 (Hsp 70). Using Real Time PCR (RTPCR) and protein concentration methods, we studied changes in levels of Hsp70 mRNA and protein synthesis after exposure to the physical stimulus. We also evaluated the suitability of using chick embryo as a model to study alteration in heat shock proteins expression and translation using specific egg incubator set up. Zero-day fertilized chicken eggs were used and a popular mobile phone and service provider was selected with 1800 MHz frequency, power of 0.47 W/kg body and SAR 1.10 w/KG (head). The total daily exposure duration was 50 minutes in each 24 hours with variable maximum exposure time. Experimental samples were divided into controls with no exposure and experimental samples. The developing embryos were removed and different organs were isolated for estimation of Hsp70mRNA and protein. This physical stimulus caused a sequential increase of mRNA corresponding to the period of exposure. Liver tissue demonstrated higher levels of mRNA than heart tissue. Nonetheless, this increase in mRNA was not matched with an increase in the amount of protein of the corresponding mRNA in both tissues at different exposure times. Total protein in all tissues remained unchanged due to slow down of the clearance process and as an indication that the cell is struggling to preserve housekeeping proteins signaling attempt of survival.

Analysis of Hyperthermia of Children in Enclosed Vehicle

Aiming at the problem of high temperature hazard in children stranded in cars, based on the thermal environment parameters of the enclosed vehicle during outdoor thermal soaking in summer, the predicted heat strain (PHS) model was used, combined with children’s height, weight, clothing and other factors, to simulate the changes in physiological indicators such as core temperature, rectal temperature and water loss, and to scientifically determined the maximum allowable exposure time. It was predicted that the core temperature of human body exceeded 38°C at 72 minutes, and then the body began to heat exhaustion.

The influence of anesthetics on neurotransmitters in the nervous system of Sepia pharaonis

Anesthesia is a stress mitigation technique widely used during transportation and short-term human manipulation, such as labeling and measurement of body parameters of aquatic animals. This is because anesthetics affect the content of neurotransmitters, exerting various effects on the body. This study determined optimal anesthetic concentration for cuttlefish by measuring the anesthetic and recovery duration of Sepia pharaonis. This was assessed with Nuclear magnetic resonance (NMR) combined with high performance liquid chromatography (HPLC) detection of nervous system metabolites and specific changes in the content of six neurotransmitters. Successful anesthetization of cuttlefish was observed with ethanol concentration (10–30 mL L−1). The cuttlefish recovered after anesthesia, with the longest exposure time being 60 min at a concentration of 10 mL L−1 ethanol. Likewise, the cuttlefish also reached a sedative state at a concentration below 5 mL L−1 ethanol, but with a maximum exposure time of 270 min. We concluded that the action of ethanol attributed to the 10–20% increase of glycine and tyrosine using NMR and HPLC analysis. We postulate the anesthetic role of ethanol in cuttlefish led to increased inhibitory neurotransmitters gamma-Aminobutyric acid, (GABA) and Glycine (Gly) while it reduced the levels of excitatory neurotransmitters acetylcholine (Ach), dopamine (DA) and 5-hydroxytryptamine (5-HT).However, cuttlefish recovery from anesthesia was probably due to rising Ach and Glutamate (Glu) levels.

Quantitative assessment of the risk of airborne transmission of SARS-CoV-2 infection: Prospective and retrospective applications

Airborne transmission is a recognized pathway of contagion; however, it is rarely quantitatively evaluated. The numerous outbreaks that have occurred during the SARS-CoV-2 pandemic are putting a demand on researchers to develop approaches capable of both predicting contagion in closed environments (predictive assessment) and analyzing previous infections (retrospective assessment).This study presents a novel approach for quantitative assessment of the individual infection risk of susceptible subjects exposed in indoor microenvironments in the presence of an asymptomatic infected SARS-CoV-2 subject. The application of a Monte Carlo method allowed the risk for an exposed healthy subject to be evaluated or, starting from an acceptable risk, the maximum exposure time. We applied the proposed approach to four distinct scenarios for a prospective assessment, highlighting that, in order to guarantee an acceptable risk of 10−3 for exposed subjects in naturally ventilated indoor environments, the exposure time could be well below one hour. Such maximum exposure time clearly depends on the viral load emission of the infected subject and on the exposure conditions; thus, longer exposure times were estimated for mechanically ventilated indoor environments and lower viral load emissions. The proposed approach was used for retrospective assessment of documented outbreaks in a restaurant in Guangzhou (China) and at a choir rehearsal in Mount Vernon (USA), showing that, in both cases, the high attack rate values can be justified only assuming the airborne transmission as the main route of contagion. Moreover, we show that such outbreaks are not caused by the rare presence of a superspreader, but can be likely explained by the co-existence of conditions, including emission and exposure parameters, leading to a highly probable event, which can be defined as a “superspreading event”.

The Effects of Clothing Insulation and Acclimation on the Thermal Comfort of Underground Mine Workers

Excessive heat exposure is among the health and safety hazards that have adverse effects on the mine workers. The very nature of the underground climate makes it a convenient avenue for heat generation and accumulation from several heat sources including autocompression, equipment, and heat from strata. This study investigated the effects of clothing insulation and acclimation on the thermal comfort of mine workers who are exposed to heat in underground working environments. Several clothing ensembles have been considered to analyze the effect of the thermal resistance of clothing on the thermal comfort of workers. To investigate the impact of the clothing insulation, the thermal comfort limit of an underground miner was calculated in the form of maximum allowable exposure time for an 8-h shift. Parametric analyses were subsequently performed using an already developed thermal comfort model using MATLAB software. The results demonstrate that clothing insulation has a significant effect on the thermal comfort of mine workers. Increase in the clothing insulation decreases the maximum allowable exposure time of mine workers. This is especially true for the new and non-acclimated workers. Since acclimatized workers can tolerate a higher level of the dehydration and are capable of losing more water by sweat per shift, the maximum allowable exposure time for the acclimated workers are higher than non-acclimated workers. These analyses have shown that acclimated workers can have more continuous work per shift compared with non-acclimated workers. For example, in an environmental condition with clothing that a non-acclimated worker cannot work more than 5 h, an acclimated worker can work a full 8-h shift.

Bactericidal and virucidal activity of ethanol and povidone-iodine.

Ethanol and povidone‐iodine (PVP‐I) are important microbicides that inactivate bacteria and viruses. The present study provides a review of literature data on the concentration‐dependent bactericidal and virucidal activity of ethanol and PVP‐I in vitro. A systematic search was performed using the meta‐database for biomedicine PubMed. Eventually, 74 studies with original data on the reduction of bacterial and viral infectivity using in vitro tests were analyzed. A safe bactericidal effect of ethanol can be expected at concentrations between 60% and 85%, and the exposure times vary between ≤0.5 and ≥5 min. Within an exposure of up to 5 min, 80%–90% ethanol also exerts virucidal/low‐level activity, which includes its action against enveloped viruses plus adeno‐, noro‐, and rotaviruses. For PVP‐I, the best bactericidal and virucidal/high‐level effect is present at a concentration range of approx. 0.08%–0.9% depending on the free iodine concentration. The maximum exposure times are 5 min for bacteria and 60 min for viruses. The available data may help optimize the significant inactivation of bacteria and viruses in various areas. However, as the conditions in application practice can vary, concrete recommendations for the application can only be derived to a limited extent.

Functionalized poly l-lactic acid synthesis and optimization of process parameters for 3D printing of porous scaffolds via digital light processing (DLP) method

In the present study, Poly l-lactic acid (PLLA) resin compatible with digital light processing (DLP) 3D printing method was synthesized to produce hard tissue scaffolds. PLLA has been chosen as a decent material to mimic biological structures due to its relatively high strength as well as proper biocompatibility and biodegradation rate. After synthesis and functionalization of PLLA, using a facile method, porous models with 600-micron pore size and 70 % nominal porosity were designed and fabricated via DLP technique in order to investigate the effects of the two process parameters, light exposure time and dye concentration, on compressive strength and morphological features of the printed samples. The experimental results were then reconciled with plotted working curves for each dye concentration to validate the defined exposure time levels. It was concluded that the synthesized polymer and the used method of 3D printing are suitable for fabricating scaffolds with intricate structures. Moreover, by conducting the compression test, a maximum 2.2 MPa strength was achieved for the sample with minimum dye concentration and maximum exposure time. From the biological point of view, no cytotoxic effect was seen after a 3-day in vitro cell viability testing. Altogether, it was shown that optimal adjustment of the process parameters is essential to achieve appropriate dimensional and mechanical properties, which were acknowledged by plotted working curves.

Análisis del ambiente físico del trabajo en aserraderos de El Salto, Durango, México

<strong>Introduction:</strong> Sawmill workers carry out their work in an adverse physical environment that influences their well-being, not knowing if safety levels in the area are acceptable. <br/> <strong>Objective:</strong> To analyze workers’ exposure to noise, thermal comfort, and lighting at five workstations in six sawmills in the El Salto region of Durango, Mexico.<br/> <strong>Materials and methods:</strong> The physical variables of the work environment were measured directly at three times of the day for seven workdays at five workstations (forklift, edger, swing saw, resaw, and head saw). The maximum allowable time of exposure to noise, thermal comfort through effective temperature, and lighting of the work area were determined. Statistical differences in physical variables between workstations, sawmills and times of the day were detected by analysis of variance and Kruskal-Wallis median range comparison tests.<br/> <strong>Results and discussion:</strong> The noise level (85 to 102 dB[A]) represents a greater hearing risk at the head saw, resaw and swing saw workstations as it exceeds 90 dB (A). Thermal comfort was 20 °C, which ensures that the worker can be exposed 100 % of the time of the workday to this temperature. Lighting levels were high, exceeding 2 000 lx.<br/> <strong>Conclusions:</strong> The noise and lighting levels are high in the assessed sawmills and pose a risk to the safety of workers if the mandatory use of ear and eye protectors is not monitored.

Feasibility of Administering Anti-CD45 Iodine (131I) Apamistamab [Iomab-B] for Targeted Conditioning in Older Patients with Active, Relapsed or Refractory AML without Lead-Lined Rooms: Ongoing Phase III Sierra Trial Experience at 6 Study Sites

<h3>Introduction</h3> Patients ≥55 years of age with active, relapsed or refractory acute myeloid leukemia (AML) who have failed standard induction and salvage therapies do not routinely undergo allogeneic hematopoietic cell transplantation due to their inability to receive myeloablative conditioning. The SIERRA trial is a prospective, randomized, phase 3, open-label, multicenter trial designed to address this significant unmet need. Preliminary results have shown that targeted conditioning with Iomab-B can lead to successful engraftment. Due to the activity level of infused ¹³¹I (300-1030 mCi, mean ∼600 mCi), patients are shielded from the public in a hospital room for 3-7 days. As a dedicated lead-lined isolation room is not always available, we present our experience from 6 SIERRA study sites demonstrating the feasibility of using mobile shielding in standard inpatient rooms to comply with radiation safety regulations. <h3>Methods</h3> Six hospitals (1. Memorial Sloan Kettering Cancer Center, 2. Banner MD Anderson Cancer Center, 3. Medical College of Wisconsin, 4. Weill Cornell Medical Center, 5. University of Nebraska Medical Center, and 6. Stony Brook University Hospital) out of 20 sites have identified regular corner inpatient rooms (4 of them are on top floor) for isolation after Iomab-B therapeutic infusion. Shielding calculations were performed taking into consideration the patient room layout, bed position, surrounding areas (hall way, nursing station and adjacent rooms) and their occupancy to determine placement of mobile shielding. Radiation surveys were performed in identified areas following Iomab-B infusion and during the isolation period. <h3>Results</h3> As shown in Table 1, both calculation with 800 mCi of ¹³¹I and the survey immediately following therapeutic (time of maximum exposure) have shown that appropriate use of mobile shields can effectively decrease the exposure rate in surrounding public accessible areas to be less than the regulated limit of 2 mR/hour. <h3>Conclusion</h3> Lead-lined rooms are not required for treating R/R AML patients with Iomab-B. The use of mobile shields enables treatment of patients in regular inpatient rooms.

EXPERIMENTO ACADÊMICO: APLICAÇÃO DO MÉTODO DE DIFERENÇAS FINITAS PARA A ANÁLISE DO RESFRIAMENTO DE UMA BETERRABA COZIDA

&#x0D; &#x0D; &#x0D; &#x0D; Diante da crescente preocupação com a segurança alimentar e seus respectivos parâmetros, estabelecidos pelos órgãos responsáveis, é importante que se saiba a respeito do tempo máximo de exposição de um alimento ao ar atmosférico de forma a evitar possíveis contaminações microbiológicas. A determinação do perfil de temperaturas nos alimentos e a forma como este varia ao longo do tempo permitem um maior controle sobre esse fator. Dessa forma, o presente estudo tem o objetivo de averiguar, por meio dos métodos numéricos de diferenças finitas e capacitância global, o processo de resfriamento de uma beterraba cozida, estabelecendo o tempo após o qual o alimento atingiria a temperatura de 60 ºC e estaria, assim, suscetível a contaminação. Após o cozimento do legume em questão, foram mensuradas as temperaturas em pontos de suas faces para intervalos de tempo preestabelecidos. Os resultados obtidos mostraram que, antes mesmo das aferições em tempos futuros, já existiam pontos na superfície às temperaturas de 52,9 e 56,6 ºC, indicando que o método utilizado não foi satisfatório para a análise inicialmente proposta.&#x0D; &#x0D; &#x0D; &#x0D;