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PurposeTo characterize the use of demographic data in multiple-choice questions from a commercial preclinical question bank and determine if there is appropriate use of different distractors.BackgroundMultiple-choice questions for medical students often include vignettes describing a patient’s presentation to help guide students to a diagnosis, but overall patterns of usage between different types of nonmedical patient information in question stems has yet to be determined.Methods380 of 453 randomly selected questions were included for analysis after determining they contained a clinical vignette and required a diagnosis. The vignettes and following explanations were then examined for the presence/absence of 11 types of demographic information, including age, sex/gender, and socioeconomic status. We compared both the usage frequency and relevance between the 11 information types.ResultsMost information types were present in less than 10% of clinical vignettes, but age and sex/gender were present in over 95% of question stems. Over 50% of questions included irrelevant information about age and sex/gender, but 75% of questions did not include any irrelevant information of other types. Patient weight and environmental exposures were significantly more likely to be relevant than age or sex/gender.DiscussionStudents using the questions in this study will frequently gain practice incorporating age and sex/gender into their clinical reasoning while receiving little exposure to other demographic information. Based on our findings, we posit that questions could include more irrelevant information, outside age and sex/gender, to better approximate real clinical scenarios and ensure students do not overvalue certain demographic data.

The purpose of this study was to see the effectiveness of the services provided on the level of anxiety of final year students towards their supervisors. This study uses experimental research methods. In this study, counseling services were carried out using self-modeling techniques to relieve final year students' anxiety towards their supervisors, this research was an experimental study with an experimental design, where the sample in this study was single subject research. Based on the results of the study, the type of counseling service with self-modeling techniques was proven to reduce the level of anxiety of final semester students towards their supervisors, marked by a significant change from the baseline state to a better level after the intervention with a decrease in score of 10.58. In conclusion, individual counseling with self-modeling techniques is generally effective in developing self-confidence and reducing the level of anxiety of final year students in dealing with supervisors. Keywords: Self Confidence, Anxiety, Self Modeling

The calcium-activated chloride channel TMEM16A enables chloride secretion across several transporting epithelia, including in the airway where it represents a therapeutic target for the treatment of cystic fibrosis. Additional roles for TMEM16A have also been proposed, including enhancing goblet cell exocytosis, increasing goblet cell numbers and stimulating smooth muscle contraction. The aim of the present study was to test whether the pharmacological regulation of TMEM16A channel function, both potentiation and inhibition, could affect any of these proposed biological roles.In vitro, a recently described potent and selective TMEM16A potentiator (ETX001) failed to stimulate mucin release from primary human bronchial epithelial (HBE) cells over a 24h exposure period using both biochemical and imaging endpoints. In addition, treatment of HBE cells with ETX001 or a potent and selective TMEM16A inhibitor (Ani9) for 4 days did not influence mucin release or goblet cell formation. In vivo, a TMEM16A potentiator was without effect on goblet cell emptying in an IL-13 driven goblet cell metaplasia model.Using freshly isolated human bronchi and pulmonary arteries, neither ETX001 or Ani9 had any effect on the contractile or relaxant responses of the tissues. In vivo, ETX001 also failed to influence either lung or cardiovascular function when delivered directly into the airways of telemetered rats.Together, these studies do not support a role for TMEM16A in the regulation of goblet cell numbers or mucin release, or on the regulation of airway or pulmonary artery smooth muscle contraction.

Emissions from oil fires associated with the “Deepwater Horizon” explosion and oil discharge that began on April 20, 2010 in the Gulf of Mexico were analyzed chemically to only a limited extent at the time but were shown to induce oxidative damage in vitro and in mice. To extend this work, we burned oil floating on sea water and performed extensive chemical analyses of the emissions (Gullett et al., Marine Pollut Bull, in press, 2017). Here, we examine the ability of a dichloromethane extract of the particulate material with an aerodynamic size ≤ 2.5 µm (PM2.5) from those emissions to induce oxidative damage in human lung cells in vitro and mutagenicity in 6 strains of Salmonella. The extract had a percentage of extractable organic material (EOM) of 7.0% and increased expression of the heme oxygenase (HMOX1) gene in BEAS-2B cells after exposure for 4 hr at 20 µg of EOM/ml. However, the extract did not alter mitochondrial respiration rate as measured by extracellular flux analysis. The extract was most mutagenic in TA100 +S9, indicative of a role for polycyclic aromatic hydrocarbons (PAHs), reflective of the high concentrations of PAHs in the emissions (1 g/kg of oil consumed). The extract had a mutagenicity emission factor of 1.8 ± 0.1 × 105 revertants/megajoulethermal in TA98 +S9, which was greater than that of diesel exhaust and within an order of magnitude of open burning of wood and plastic. Thus, organics from PM2.5 of burning oil can induce oxidative responses in human airway epithelial cells and are highly mutagenic. Environ. Mol. Mutagen. 58:162–171, 2017. © 2017 Wiley Periodicals, Inc.

QuestionCystic fibrosis (CF) is characterised by the accumulation of viscous adherent mucus in the lungs. While several hypotheses invoke a direct relationship with cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction (i.e. acidic airway surface liquid (ASL) pH, low bicarbonate (HCO3−) concentration, airway dehydration), the dominant biochemical alteration of CF mucus remains unknown.Materials/methodsWe characterised a novel cell line (CFTR-KO Calu3 cells) and the responses of human bronchial epithelial (HBE) cells from subjects with G551D or F508del mutations to ivacaftor and elexacaftor-tezacaftor-ivacaftor. A spectrum of assays such as short-circuit currents, quantitative PCR, ASL pH, Western blotting, light scattering/refractometry (size-exclusion chromatography with inline multi-angle light scattering), scanning electron microscopy, percentage solids and particle tracking were performed to determine the impact of CFTR function on mucus properties.ResultsLoss of CFTR function in Calu3 cells resulted in ASL pH acidification and mucus hyperconcentration (dehydration). Modulation of CFTR in CF HBE cells did not affect ASL pH or mucin mRNA expression, but decreased mucus concentration, relaxed mucus network ultrastructure and improved mucus transport. In contrast with modulator-treated cells, a large fraction of airway mucins remained attached to naïve CF cells following short apical washes, as revealed by the use of reducing agents to remove residual mucus from the cell surfaces. Extended hydration, but not buffers alkalised with sodium hydroxide or HCO3−, normalised mucus recovery to modulator-treated cell levels.ConclusionThese results indicate that airway dehydration, not acidic pH and/or low [HCO3−], is responsible for abnormal mucus properties in CF airways and CFTR modulation predominantly restores normal mucin entanglement.

Emissions from oil fires associated with the Deepwater Horizon explosion and oil discharge that began on April 20, 2010 in the Gulf of Mexico were analyzed chemically to only a limited extent at the time but were shown to induce oxidative damage in vitro and in mice. To extend this work, we burned oil floating on sea water and performed extensive chemical analyses of the emissions [Gullett et al., submitted]. Here we examine the ability of a dichloromethane extract of the particulate material with an aerodynamic size ≤ 2.5 µm (PM2.5) from those emissions to induce oxidative damage in human lung cells in vitro and mutagenicity in 6 strains of Salmonella. The extract had a percentage of extractable organic material (EOM) of 7.0% and increased expression of the heme oxygenase (HMOX1) gene in BEAS-2B cells after exposure for 4 h at 20 µg of EOM/ml. However, the extract did not alter mitochondrial respiration rate as measured by extracellular flux analysis. The extract was most mutagenic in TA100 +S9, indicative of a role for polycyclic aromatic hydrocarbons (PAHs), reflective of the high concentrations of PAHs in the emissions (1 g/kg of oil consumed). The extract had a mutagenicity emission factor of 1.8 ± 0.1 × 105 revertants/megajoulethermal in TA98 +S9, which was greater than that of diesel exhaust and within an order of magnitude of wood burning in residential fireplaces and the open burning of plastic. Thus, organics from PM2.5 of burning oil can induce oxidative responses in human airway epithelial cells and are highly mutagenic.

This paper presents a model and its identification, which characterizes the thermal dynamic heating cycle for No. 22 Hot Blast Stove, located in the No. 2 Blast Furnace, at “CompaniaSiderurgicaHuachipato” in Talcahuano, Chile. System identification was used to model the dynamics for heating cycle based on the empirical data from the plant. In addition, a control system is proposed to obtain heating curves that generate energy savings. Model Predictive Control (MPC) was employed to minimize the tracking error to the reference while satisfying operation constraints. The feasibility of the proposal is verified according to the simulation results, estimating a 4% savings in fuel usage.