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1.
Sensors (Basel) ; 20(12)2020 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-32599903

RESUMO

There is currently a large demand for aluminum components to measure the mechanical and thermal loads to which they are subjected. With structural health monitoring, components in planes, vehicles, or bridges can monitor critical loads and potentially prevent an impending fatigue failure. Externally attached sensors need a structural model to obtain knowledge of the mechanical load at the point of interest, whereas embedded sensors can be used for direct measurement at the point of interest. To produce an embedded sensor, which is automatically encapsulated against environmental influence, the sensor must be able to withstand the boundary conditions of the host component's manufacturing process. This embedding process is particularly demanding in the case of casting. Previous work showed that silicon-based sensors have a high failure rate when embedded in cast aluminum parts and that using aluminum as a substrate is preferable under these circumstances. In the present paper, we present the fabrication process for the combination of a thick-film insulation and a thin-film strain gauge sensor, on such an aluminum substrate. The sensor is capable of withstanding high temperatures of at least 600 °C for over 20 min and a subsequent embedding in a gravity die casting process.

2.
Br J Hosp Med (Lond) ; 81(6): 1-3, 2020 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-32589538

RESUMO

Amid the global COVID-19 pandemic, adaptation of healthcare systems, with strong medical leadership, has been integral to coping with the ever-changing situation. This article is based on the personal experiences of doctors in the NHS and insights into the frontline response to this situation. It reflects on leadership dilemmas and strategies implemented to overcome them, with a focus on systems thinking and adaptive leadership.


Assuntos
Infecções por Coronavirus/epidemiologia , Liderança , Pandemias , Médicos , Pneumonia Viral/epidemiologia , Medicina Estatal/organização & administração , Análise de Sistemas , Betacoronavirus , Humanos , Reino Unido/epidemiologia
3.
Emerg Infect Dis ; 26(7): 1456-1464, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32568037

RESUMO

Invasive listeriosis is a severe foodborne infection in humans and is difficult to control. Listeriosis incidence is increasing worldwide, but some countries have implemented molecular surveillance programs to improve recognition and management of listeriosis outbreaks. In Germany, routine whole-genome sequencing, core genome multilocus sequence typing, and single nucleotide polymorphism calling are used for subtyping of Listeria monocytogenes isolates from listeriosis cases and suspected foods. During 2018-2019, an unusually large cluster of L. monocytogenes isolates was identified, including 134 highly clonal, benzalkonium-resistant sequence type 6 isolates collected from 112 notified listeriosis cases. The outbreak was one of the largest reported in Europe during the past 25 years. Epidemiologic investigations identified blood sausage contaminated with L. monocytogenes highly related to clinical isolates; withdrawal of the product from the market ended the outbreak. We describe how epidemiologic investigations and complementary molecular typing of food isolates helped identify the outbreak vehicle.

4.
GMS J Med Educ ; 37(3): Doc33, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32566735

RESUMO

Medical education has the responsibility to react to developments and changing demands in healthcare. This implies the need for experts in the area of medical education as well as nationally coordinated initiatives. An innovative model based on trans-institutional cooperation and nationwide consensus for establishing a master's degree course in Medical Education (MME) and long-term results are presented here to other countries and other programs, facing similar challenges. A MME program with the following goals was implemented at the Medical Faculty of Heidelberg University, Germany, in 2004: Qualification of leaders in medical faculties, professionalization and improvement of teaching quality, promotion of nationwide and international exchange, and stimulation of research in medical education. Since then, 15 cohorts with a total of 380 participants have started their studies, 179 participants have graduated and 90 publications resulted from the master's theses (as at November 2018). Evaluation and survey data revealed a very high degree of satisfaction among the participants and a lasting development to medical education experts. Our concept shows that the bundling of regional expertise into a clearly structured trans-institutional network can be a driving force for nationwide comprehensive changes, in order to address changing demands in healthcare systems and transfer it into medical education programs.

5.
GMS J Med Educ ; 37(3): Doc34, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32566736

RESUMO

Objective: We analyze the extent to which students of human, veterinary and dental medicine complete study-related stays abroad (frequency, type and duration of stays abroad and countries visited). Furthermore, we investigate the possible correlations between completed stays abroad and the duration of studies, the completion of a doctorate and entering professional life. Methods: The data come from a written cross-sectional survey of 742 graduates of their respective study programs at Bavarian universities. The evaluation was carried out using descriptive and inferential statistical methods. Results: Slightly more than half of the surveyed students completed study-associated stays abroad, with notable differences between the three study programs. The students most frequently completed internships abroad lasting an average of nine weeks. Switzerland was the most common country of destination for the stays abroad. Furthermore, there were no or only weak correlations between stays abroad, the duration of studies and progress towards a doctorate or the commencement of professional employment abroad. There were no correlations with the stress experienced as part of initial employment after graduation. Conclusion: The results clearly indicate that stays abroad are quite usual for students in the medical disciplines and are almost standard in the study of human medicine. The selection of the countries visited indicates that the primary goal of the students' stays abroad is to deepen their competence with a view to later employment in their home country.

6.
Patient Educ Couns ; 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32423834

RESUMO

OBJECTIVE: Emotion-handling skills are key components for interpersonal communication by medical professionals. The Verona Coding Definitions of Emotional Sequences (VR-CoDES) appears useful to develop a Situational Judgment Test (SJT) for assessing emotion-handling skills. METHODS: In phase 1 we used a multi-stage process with expert panels (npanel1 = 16; npanel2 = 8; npanel3 = 20) to develop 12 case vignettes. Each vignette includes (1) video representing a critical incident containing concern(s) and/or cue(s), (2) standardized lead-in-question, (3) five response alternatives. In phase 2 we piloted the SJT to assess validity via an experimental study with medical students (n = 88). RESULTS: Experts and students rated most of the 'Reduce space' responses as inappropriate and preferred 'Explicit' responses. Women scored higher than men and there was no decline of empathy according to students' year of study. There were medium correlations with self-assessment instruments. The students' acceptance of the SJT was high. CONCLUSION: The use of VR-CoDES, authentic vignettes, videos and expert panels contributed to the development and validity of the SJT. PRACTICE IMPLICATIONS: Development costs were high but could be made up over time. The agreement on a proper score and the implementation of an adequate feedback structure seem to be useful.

7.
Perspect Med Educ ; 2020 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-32468274

RESUMO

INTRODUCTION: In high-stakes assessment, the measurement precision of pass-fail decisions is of great importance. A concept for analyzing the measurement precision at the cut score is conditional reliability, which describes measurement precision for every score achieved in an exam. We compared conditional reliabilities in Classical Test Theory (CTT) and Item Response Theory (IRT) with a special focus on the cut score and potential factors influencing conditional reliability at the cut score. METHODS: We analyzed 32 multiple-choice exams from three Swiss medical schools comparing conditional reliability at the cut score in IRT and CCT. Additionally, we analyzed potential influencing factors such as the range of examinees' performance, year of study, and number of items using multiple regression. RESULTS: In CTT, conditional reliability was highest for very low and very high scores, whereas examinees with medium scores showed low conditional reliabilities. In IRT, the maximum conditional reliability was in the middle of the scale. Therefore, conditional reliability at the cut score was significantly higher in IRT compared with CTT. It was influenced by the range of examinees' performance and number of items. This influence was more pronounced in CTT. DISCUSSION: We found that conditional reliability shows inverse distributions and conclusions regarding the measurement precision at the cut score depending on the theory used. As the use of IRT seems to be more appropriate for criterion-oriented standard setting in the framework of competency-based medical education, our findings might have practical implications for the design and quality assurance of medical education assessments.

8.
Mol Ecol ; 2020 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-32395881

RESUMO

It is generally accepted that the spatial distribution of neutral genetic diversity within a species' native range mostly depends on effective population size, demographic history, and geographic position. However, it is unclear how genetic diversity at adaptive loci correlates with geographic peripherality or with habitat suitability within the ecological niche. Using exome-wide genomic data and distribution maps of the Alpine range, we first tested whether geographic peripherality correlates with four measures of population genetic diversity at > 17,000 SNP loci in 24 Alpine populations (480 individuals) of Swiss stone pine (Pinus cembra) from Switzerland. To distinguish between neutral and adaptive SNP sets, we used four approaches (two gene diversity estimates, FST outlier test, and environmental association analysis) that search for signatures of selection. Second, we established ecological niche models for P. cembra in the study range and investigated how habitat suitability correlates with genetic diversity at neutral and adaptive loci. All estimates of neutral genetic diversity decreased with geographic peripherality, but were uncorrelated with habitat suitability. However, heterozygosity (He ) at adaptive loci based on Tajima's D declined significantly with increasingly suitable conditions. No other diversity estimates at adaptive loci were correlated with habitat suitability. Our findings suggest that populations at the edge of a species' geographic distribution harbour limited neutral genetic diversity due to demographic properties. Moreover, we argue that populations from suitable habitats went through strong selection processes, are thus well adapted to local conditions, and therefore exhibit reduced genetic diversity at adaptive loci compared to populations at niche margins.

9.
Radiologe ; 2020 Apr 04.
Artigo em Alemão | MEDLINE | ID: mdl-32248250

RESUMO

PURPOSE: To objectify effects of an anatomical viewing scheme on the respective correctness of (a) findings, (b) interpretations, and (c) self-assessments of readers in chest radiographs acquired in one plane and the assessment of other influencing factors. MATERIALS AND METHODS: In all, 20 radiologists with 3-60 months of full-time radiography experience evaluated 12 chest radiographs of varying difficulty: once with and once without using an anatomical viewing scheme with at least 1 month in between (n = 480). In consensus of 3 radiological experts (a) and (b) were determined by means of a current computed tomography. The self-assessment (c) of readers was queried. RESULTS: (a) Findings were either missed or not described in 21%. Another 20% were recognized, but incorrectly described, (b) 62% of interpretations and 31% of derived clinical consequences were wrong and (c) in 39% of items the readers overestimated themselves. Experts were faster and better than novices, but for the scheme usage no further significant differences were detected (p > 0.5, respectively). The most pronounced effect was found in comparison with the routine report produced by the joint evaluation of novices and experts being clearly superior even to the expert study results (a), (b) and (c) alone (p < 0.001, respectively). CONCLUSION: Reporting of chest X­rays acquired in one plane was often incomplete or even wrong, and the evaluators overestimated themselves, which was not influenced by the use of the anatomical viewing scheme. Since errors between the evaluators sometimes differed greatly, duplicate evaluation of the radiographs by two different radiologists, which is already the case in many training facilities, may possibly be advisable in general.

10.
GMS J Med Educ ; 37(1): Doc11, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32270025

RESUMO

Objective: ECG interpretation is prone to errors that can lead to relevant misdiagnoses and incorrect treatment. Prompts are one way in lectures to encourage learning from one's own mistakes and to reduce error rates. Prompts are measures such as questions, hints, and suggestions of content-related or metacognitive nature, which can lead to self-explanation in the learner and thus to a deeper understanding of an issue. The aim of the study was therefore to investigate whether the use of prompts can reduce the error rate in ECG interpretation among students. Method: In a 2x2 experimental test and control group design, N=100 final year medical students carried out ECG interpretation tasks in the form of online case vignettes in CASUS®. In these tasks, justification prompts (B) and error analysis prompts (F) were systematically varied in four groups and the learning success was measured using a knowledge test. In addition, prior knowledge in ECG interpretation, motivation, interest in the topic, subjective confidence in ECG interpretation, and cognitive load was collected. Results: Neither error analysis prompts nor justification prompts had a significant effect on the correct ECG interpretation by students, F(1,96)=1.03, p=.31. Justification prompts seemed to have a positive effect on the confidence of answering the questions, F(1,96)=10.15, p=.002, partial η 2 =.10; and a negative effect on student motivation, F(1,96)=8.13 , p=.005, partial η 2 =.08; but both with comparable diagnostic accuracy. Conclusion: The present study could not confirm the positive effects of prompts on the error rate in ECG interpretation reported in the literature but showed significant effects on subjective confidence and motivation which should be investigated in further studies.

11.
J Phys Chem Lett ; : 3601-3607, 2020 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-32302143

RESUMO

Using time-lapsed ambient-pressure X-ray photoelectron spectroscopy, we investigate the thermal oxidation of single-crystalline Ir(100) films toward rutile IrO2(110) in situ. We initially observe the formation of a carbon-free surface covered with a complete monolayer of oxygen, based on the binding energies of the Ir 4f and O 1s core level peaks. During a rather long induction period with nearly constant oxygen coverage, the work function of the surface changes continuously as sensed by the gas phase O 1s signal. The sudden and rapid formation of the IrO2 rutile phase with a thickness above 3 nm, manifested by distinct binding energy changes and substantiated by quantitative XPS analysis, provides direct evidence that the oxide film is formed via an autocatalytic growth mechanism that was previously proposed for PbO and RuO2.

12.
Stem Cell Reports ; 14(5): 788-802, 2020 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-32302556

RESUMO

Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) represent an attractive model to investigate CM function and disease mechanisms. One characteristic marker of ventricular specificity of human CMs is expression of the ventricular, slow ß-myosin heavy chain (MyHC), as opposed to the atrial, fast α-MyHC. The main aim of this study was to investigate at the single-cell level whether contraction kinetics and electrical activity of hESC-CMs are influenced by the relative expression of α-MyHC versus ß-MyHC. For effective assignment of functional parameters to the expression of both MyHC isoforms at protein and mRNA levels in the very same hESC-CMs, we developed a single-cell mapping technique. Surprisingly, α- versus ß-MyHC was not related to specific contractile or electrophysiological properties of the same cells. The multiparametric cell-by-cell analysis suggests that in hESC-CMs the expression of genes associated with electrical activity, contraction, calcium handling, and MyHCs is independently regulated.

14.
BMC Med Educ ; 20(1): 73, 2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32171297

RESUMO

INTRODUCTION: Clinical reasoning has been fostered with varying case formats including the use of virtual patients. Existing literature points to different conclusions regarding which format is most beneficial for learners with diverse levels of prior knowledge. We designed our study to better understand which case format affects clinical reasoning outcomes and cognitive load, dependent on medical students' prior knowledge. METHODS: Overall, 142 medical students (3 rd to 6 th year) were randomly assigned to either a whole case or serial cue case format. Participants worked on eight virtual patients in their respective case format. Outcomes included diagnostic accuracy, knowledge, and cognitive load. RESULTS: We found no effect of case format on strategic knowledge scores pre- vs post-test (whole case learning gain = 3, 95% CI. -.01 to .01, serial cue learning gain = 3, 95% CI. -.06 to .00 p = .50). In both case formats, students with high baseline knowledge (determined by median split on the pre-test in conceptual knowledge) benefitted from learning with virtual patients (learning gain in strategic knowledge = 5, 95% CI .03 to .09, p = .01) while students with low prior knowledge did not (learning gain = 0, 95%CI -.02 to .02). We found no difference in diagnostic accuracy between experimental conditions (difference = .44, 95% CI -.96 to .08, p = .22), but diagnostic accuracy was higher for students with high prior knowledge compared to those with low prior knowledge (difference = .8, 95% CI 0.31 to 1.35, p < .01). Students with low prior knowledge experienced higher extraneous cognitive load than students with high prior knowledge (multiple measurements, p < .01). CONCLUSIONS: The whole case and serial cue case formats alone did not affect students' knowledge gain or diagnostic accuracy. Students with lower knowledge experienced increased cognitive load and appear to have learned less from their interaction with virtual patients. Cognitive load should be taken into account when attempting to help students learn clinical reasoning with virtual patients, especially for students with lower knowledge.

16.
J Biol Chem ; 295(18): 5970-5983, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32184353

RESUMO

Barttin is the accessory subunit of the human ClC-K chloride channels, which are expressed in both the kidney and inner ear. Barttin promotes trafficking of the complex it forms with ClC-K to the plasma membrane and is involved in activating this channel. Barttin undergoes post-translational palmitoylation that is essential for its functions, but the enzyme(s) catalyzing this post-translational modification is unknown. Here, we identified zinc finger DHHC-type containing 7 (DHHC7) protein as an important barttin palmitoyl acyltransferase, whose depletion affected barttin palmitoylation and ClC-K-barttin channel activation. We investigated the functional role of barttin palmitoylation in vivo in Zdhhc7 -/- mice. Although palmitoylation of barttin in kidneys of Zdhhc7 -/- animals was significantly decreased, it did not pathologically alter kidney structure and functions under physiological conditions. However, when Zdhhc7 -/- mice were fed a low-salt diet, they developed hyponatremia and mild metabolic alkalosis, symptoms characteristic of human Bartter syndrome (BS) type IV. Of note, we also observed decreased palmitoylation of the disease-causing R8L barttin variant associated with human BS type IV. Our results indicate that dysregulated DHHC7-mediated barttin palmitoylation appears to play an important role in chloride channel dysfunction in certain BS variants, suggesting that targeting DHHC7 activity may offer a potential therapeutic strategy for reducing hypertension.

17.
J Exp Biol ; 223(Pt 7)2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32098886

RESUMO

A considerable body of work has examined the dynamics of different dog gaits, but there are no studies that have focused on limb dynamics in jumping. Jumping is an essential part of dog agility, a dog sport in which handlers direct their dogs through an obstacle course in a limited time. We hypothesized that limb parameters like limb length and stiffness indicate the skill level of dogs. We analyzed global limb parameters in jumping for 10 advanced and 10 beginner dogs. In experiments, we collected 3D kinematics and ground reaction forces during dog jumping at high forward speeds. Our results revealed general strategies of limb control in jumping and highlighted differences between advanced and beginner dogs. In take-off, the spatially leading forelimb was 75% (P<0.001) stiffer than the trailing forelimb. In landing, the trailing forelimb was 14% stiffer (P<0.001) than the leading forelimb. This indicates a strut-like action of the forelimbs to achieve jumping height in take-off and to transfer vertical velocity into horizontal velocity in landing (with switching roles of the forelimbs). During landing, the more (24%) compliant forelimbs of beginner dogs (P=0.005) resulted in 17% (P=0.017) higher limb compression during the stance phase. This was associated with a larger amount of eccentric muscle contraction, which might in turn explain the soft tissue injuries that frequently occur in the shoulder region of beginner dogs. For all limbs, limb length at toe-off was greater for advanced dogs. Hence, limb length and stiffness might be used as objective measures of skill.

18.
Eur J Clin Nutr ; 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32001814

RESUMO

BACKGROUND: Weight maintenance remains to be a challenge for patients in a reduced obese state and it has been recommended to provide them more individualized support. For this purpose it is crucial to understand the barriers patients are experiencing after weight loss. Many have been identified by qualitative studies. We evaluated if a quantitative assessment of patient perspective during weight maintenance can help identify major barriers that refer to actual regain. METHODS: Follow-up data were analyzed from patients attempting weight maintenances after successful completion of a nonsurgical weight loss and lifestyle intervention for morbid obesity. The data were acquired at mandatory follow-up assessments and included rating of 26 probable difficulties. A principal component analysis was carried out to explore whether these difficulties could be grouped into meaningful factors. Associations with socio-demographics, follow-up time, and weight changes were evaluated. RESULTS: Data from 88 out of 102 patients were available (baseline BMI 49.5 ± 7.4 kg/m2; 12-month weight loss 24.3 ± 9.6%; follow-up time 1.48 ± 0.6 years). Four solid factors, composed of 21 items and explaining 56% of the variance were extracted and interpreted as 'Hedonic Hunger', 'Mental Distress', 'Binge Eating', and 'Demoralization'. Weight regain (12.4 ± 12%) was correlated with each factor, most closely with 'Mental Distress' (r = 0.38). When controlling for age and follow-up time, 'Binge Eating' was the most important predictor (adj. R2 = 0.297). CONCLUSIONS: A quantitative assessment of patient perspective during the first years after weight loss can help identify valid barriers to weight loss maintenance.

19.
Anaerobe ; 62: 102152, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32001335

RESUMO

BACKGROUND: In microbiological diagnosis of periprosthetic joint infection (PJI) there is much controversial discussion about culture media and incubation time, especially if anaerobic bacteria are the causative agents. This retrospective analysis was conducted to compare the results obtained by inoculation of sonicate fluid from prosthetic components into BD Bactec blood culture bottles with those obtained by our culture method using sensitive supplemented growth media. METHODS: Twenty-eight cases were included in this study. For definition of PJI, the criteria of the Musculoskeletal Infection Society (MSIS) were considered. The quantity and time to positivity of anaerobes detected in sonicate fluid were monitored both from inoculated supplemented liver thioglycollate broth and anaerobic blood culture bottles. Furthermore, phenotypic testing was performed on the antimicrobial activity within the sonicate fluid. RESULTS: The most frequently isolated microbes were Cutibacterium species, followed by Finegoldia magna, Parvimonas micra, Robinsoniella peoriensis, Clostridium species, Peptoniphilus harei and Slackia exigua. In 24 cases, the microorganisms became detectable within five days (median time 3.2 days) when sonicate fluid was incubated in supplemented liver thioglycollate broth, regardless of whether the patients had taken antimicrobial agents prior to surgery. However, when sonicate fluid was inoculated into anaerobic Bactec bottles, the median time to positivity was 7.4 days and only 12 cases (43%) were correctly identified. Sixteen cases remained negative after 14 days of incubation. CONCLUSION: Depending on the pathogen, incubation of sonicate fluid using blood culture bottles can support diagnosis of PJI but compared with our culture medium it is less efficient if anaerobes are the suspected cause of infection. Microbiological expertise is therefore indispensable to ensure reliable detection of these microorganisms in PJI until a gold standard for laboratory handling of anaerobes has been established.

20.
Med Teach ; 42(5): 578-584, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32024438

RESUMO

Aim: To develop and pilot a General Practice (GPr) OSCE assessing medical students dealing with patient encounters, which are typical for GPr and to compare different measurement instruments (global ratings, content-specific checklists).Methods: A blueprint based on Entrusted Professional Activities was used to develop prototypical OSCE stations. Four stations were tested with voluntary medical students. Students were videotaped and assessed with self-developed content-specific checklists, a global rating for communication skills, and mini-CEX. Results were compared according to students' phases of studies.Results: All three measurements were able to discriminate between clinical and pre-clinical students. Clearest results were achieved by using mini-CEX. Content-specific checklists were not able to differentiate between those groups for the more difficult stations. Inter-station reliability for the global ratings was sufficient for high-stakes exams. Students enjoyed the OSCE-setting simulating GPr consultation hours. They would prefer feedback from GPs after the OSCE and from simulated patients after each encounter.Discussion and conclusion: Although the OSCE was short, results indicate advantages for using a global rating instead of checklists. Further research should include validating these results with a larger group of students and to find the threshold during the phases of education for switching from checklists to global ratings.

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