Empirisch gestützte Entwicklung von Lerneinheiten zum Umgang mit Multimetern

Im Rahmen der Plattform FLexKom werden an der RWTH Aachen University Unterrichtsmaterialien zum Fördern und Lernen experimenteller Kompetenzen entwickelt. Dabei wurden auch zwei Module konzipiert, die den Umgang mit Multimetern thematisieren. Um einen detaillierten Einblick in die diesbezüglichen Fähigkeiten von Schülerinnen und Schülern und typische Schwierigkeiten bei der Nutzung von Multimetern zu erlangen, wurden umfangreiche Daten aus virtuellen Experimenten zu elektrischen Schaltungen analysiert. Diese Daten stammen aus dem Test zur Messung experimenteller Kompetenz in Large Scale Assessments (MeK-LSA) von H. Theyßen et al., in dem der Aufbau eines Experiments eine von acht getesteten Kompetenzen ist. Mittels 101 Testdatensätzen konnten verschiedene Fehler im Umgang mit Multimetern ausfindig gemacht werden, die gehäuft bei den Schülerinnen und Schülern aufgetreten sind. Diese Ergebnisse bildeten die Grundlage für die Entwicklung von zwei Modulen, in denen separat darauf fokussiert wird, wie Ampere- und Voltmeter in einen elektrischen Schaltkreis integriert bzw. eingestellt werden müssen. Neben den Ergebnissen der Analyse der MeK-LSA-Daten werden auch die konzipierten Module mit ihren Experimentieraufgaben und erste Ergebnisse ihrer Evaluierung vorgestellt

The effect of distension pressure on endothelial injury and vasodilatation response in saphenous vein grafts: conversion of a bypass graft to a dead pipe

Introduction: Endothelial damage caused by high pressure applied for spasm relaxation during graft preparation is one of the most plausible theories explaining early graft failure. Aim of the study: We aimed to demonstrate the extent of endothelial damage in saphenous vein grafts distended to different pressure levels by using immunohistochemical methods and in vitro tissue baths. Material and methods: Saphenous vein grafts (SVGs) of 25 patients who underwent isolated elective CABG surgery were used in this study. By using a specific mechanism, SVGs were distended to five different pressure levels for two minutes: 0 mmHg, 50 mmHg, 100 mmHg, 200 mmHg, 300 mmHg. In vitro tissue baths and immunohistochemical examinations were performed. Results: None of the grafts distended to 300 mmHg pressure were functional in the tissue bath system. The relaxation response to carbachol of SVGs distended to 0, 50, 100 and 200 mmHg was 97.87 +/- 4.47%, 98.52 +/- 3.95%, 93.78 +/- 3.64%, and 30.87 +/- 4.11%, respectively. There were no statistically significant differences in terms of relaxation responses between samples distended to 0, 50, and 100 mmHg (p = 0.490). The relaxation response of samples distended to 200 mmHg was significantly decreased (p = 0.021). The endothelia of samples distended to 0 mmHg were almost intact in CD31 staining. Endothelial cell loss occurred at all tested distension pressures at different degrees. Conclusion: In vitro and immunohistochemical studies revealed that distending an SVG used for coronary artery bypass grafting with pressures of 100 mmHg or less results in less endothelial damage and increases graft patency

Mucoid Cyst of The Penile Skin: A Rare Entity

A 9-year old male patient was admitted to our clinic for circumcision. Physical examination revealed a mass in the prepuce. After excision of the mass, histopathological examination was consistent with a mucoid cyst of the penile skin, which has been rarely reported. Pathologists and clinicians dealing with genitourinary system pathology should be familiar with this rarely encountered entity.Key Words: Mucoid cyst, penile ski

FACTORS AFFECTING INSOLE USAGE IN PATIENTS WITH PES PLANUS

Introduction: Insoles and exercise programs are the main treatment methods for pes planus patients. Insole using may prevent the formation of pain in daily activities as well as increasing the quality of walking. The aim of this study was to investigate insole usage time and the factors affecting this situation in patient with pes planus. Materials and Methods: 136 patients with pes planus who were prescribed an insole, included in the study. We invited patients to participate in a telephone survey. Patients´ demographics, insole usage time, reasons to quit and the quitting time were questioned. Insole usage rates and the demographic data of patients were compared. Results: Of the 136 patients included in the present study, 80 were women (59%) and 56 were male (31%). 86 of these patients used an insole six months and over, 15 of them used shorter than six months and 35 of them bought the insoles but they didn't use it (63%, 11% and 26% respectively ). The average age of patients who used insoles was 32.80±18.14 and who did not use insoles was 40.77±12.54 (p=0.04). 33.8 percent of women and 14.3 percent of men did not use insoles. This difference is statistically significant (p=0.04). We did not find any significant relationship between height, weight, body mass index values and usage of insoles (p>0:05). Conclusion: The use of insoles in treating patients with pes planus is widely accepted and may be affected by the demographics such as gender and age. Besides wearing comfort, female sex and older age should be considered that may affect the use of insoles

Empirisch gestützte Entwicklung von Lerneinheiten zum Umgang mit Multimetern

Im Rahmen der Plattform FLexKom werden an der RWTH Aachen University Unterrichtsmaterialien zum Fördern und Lernen experimenteller Kompetenzen entwickelt. Dabei wurden auch zwei Module konzipiert, die den Umgang mit Multimetern thematisieren. Um einen detaillierten Einblick in die diesbezüglichen Fähigkeiten von Schülerinnen und Schülern und typische Schwierigkeiten bei der Nutzung von Multimetern zu erlangen, wurden umfangreiche Daten aus virtuellen Experimenten zu elektrischen Schaltungen analysiert. Diese Daten stammen aus dem Test zur Messung experimenteller Kompetenz in Large Scale Assessments (MeK-LSA) von H. Theyßen et al., in dem der Aufbau eines Experiments eine von acht getesteten Kompetenzen ist. Mittels 101 Testdatensätzen konnten verschiedene Fehler im Umgang mit Multimetern ausfindig gemacht werden, die gehäuft bei den Schülerinnen und Schülern aufgetreten sind. Diese Ergebnisse bildeten die Grundlage für die Entwicklung von zwei Modulen, in denen separat darauf fokussiert wird, wie Ampere- und Voltmeter in einen elektrischen Schaltkreis integriert bzw. eingestellt werden müssen. Neben den Ergebnissen der Analyse der MeK-LSA-Daten werden auch die konzipierten Module mit ihren Experimentieraufgaben und erste Ergebnisse ihrer Evaluierung vorgestellt

Relationship between lymphovascular invasion and clinicopathological features of papillary thyroid carcinoma

Lymphovascular invasion (LVI) is an important prognostic factor in various solid tumors, however, data on the association between LVI and thyroid carcinomas are limited. In this study, we evaluated the relationship between LVI and clinicopathological features of papillary thyroid carcinoma (PTC). Six hundred seventy-eight patients diagnosed with PTC between 2012 and 2015 were included into the study. Patients were classified based on the presence or absence of LVI. Gender, age, ultrasonography (US), tumor size and multifocality, BRAFV600E mutation, perineural and capsular invasion, extrathyroid extension (ETE), nodal metastasis, and recurrences were evaluated, and risk analysis was performed for each parameter. The number of patients with LVI [LVI (+)] was 63, while the number of patients without LVI [LVI (-)] was 615. The female/male ratio was 564/114. LVI was present in 18.4% of male patients and in 7.4 % of female patients. In the age group between 17-25 years LVI was detected in 6/13 patients, and this result was statistically significant compared to other age groups (p = 0.004). Suspicious lymph nodes upon US, perineural or capsular invasion, ETE, tumor size, and nodal metastasis were significantly more frequent in LVI (+) group (p < 0.001). The frequency of BRAFV600E mutation was also significantly higher in LVI (+) group (p < 0.001). Overall, the presence of LVI was associated with gender, tumor size, age, lymph node metastasis, pathological lymph nodes, perineural and capsular invasion, ETE, and BRAFV600E mutation. These results suggest that in PTC patients undergoing thyroidectomy, the presence of LVI should be considered as an indicator of aggressive clinicopathological features and those patients should be followed up carefully for recurrences and metastasis

Sensorimotor pathway controlling stopping behavior during chemotaxis in the Drosophila melanogaster larva.

Sensory navigation results from coordinated transitions between distinct behavioral programs. During chemotaxis in the Drosophila melanogaster larva, the detection of positive odor gradients extends runs while negative gradients promote stops and turns. This algorithm represents a foundation for the control of sensory navigation across phyla. In the present work, we identified an olfactory descending neuron, PDM-DN, which plays a pivotal role in the organization of stops and turns in response to the detection of graded changes in odor concentrations. Artificial activation of this descending neuron induces deterministic stops followed by the initiation of turning maneuvers through head casts. Using electron microscopy, we reconstructed the main pathway that connects the PDM-DN neuron to the peripheral olfactory system and to the pre-motor circuit responsible for the actuation of forward peristalsis. Our results set the stage for a detailed mechanistic analysis of the sensorimotor conversion of graded olfactory inputs into action selection to perform goal-oriented navigation

Alcoholic extract of Tarantula cubensis (Theranekron®) induce autophagy on gastric cancer cells

Aim: To evaluate the effects of theranekron in respect of autophagy on gastric cancer that is the fifth leading cancer type worldwide. Metods: In the present study, metastatic AGS and non-metastatic MKN-45 human gastric cell lines were used together with HEK-293 non-cancer cells as controls. Cytotoxic effect of theranekron besides appropriate treatment time was investigated through cell proliferation by using Cell Proliferation assay Kit (MTT) using different concentrations of the drug. The autophagic effect of the drug was determined using the LC3-GFP translocation assay and western blot analysis. All experiments were performed also using the ethanol since Tarantula cubensis spider was processed and diluted in 60% alcohol to generate as a drug. Results: MTT assay results demonstrated that the half maximal inhibitory concentration of theranekron was ~100 μM, its effect was found to be significant at 6 hrs, and theranekron decreased the cell viability in all cell lines without specificity in respect to the increasing concentrations. Additionally, a significantly increased GFP accumulation was detected in the autophagosomes of the cells treated with theranekron compared to non-treated cells, indicating the presence of autophagy. Conclusion: These findings were confirmed by LC3-I to LC3-II conversion with the western blot analysis. The data of ethanol experiments; however, demonstrated that ethanol also induced a cytotoxic effect and autophagic cell death. Our results suggested that theranekron results in cell death and stimulate autophagy process, but it is not specific for cancer cells since it represented similar results on non-cancer control cells. Moreover, the effect of theranekron on cell death might mostly occur through alcohol in which it is extracted

Performance of the Bethesda system for reporting thyroid cytology in multi-institutional large cohort of pediatric thyroid nodules: a detailed analysis

Background: To evaluate the performance of TBSRTC through multi-institutional experience in the paediatric population and questioning the management recommendation of ATA Guidelines Task Force on Paediatric Thyroid Cancer; Methods: A retrospective search was conducted in 4 institutions to identify consecutive thyroid FNAC cases in paediatric population between 2000 and 2018. Following the 2nd TBSRTC, the risk of malignancy ratios (ROMs) was given in ranges and calculated by 2 different ways. Sensitivity, specificity, PPV, NPV and DA ratios were calculated using histologic diagnosis as the gold standard; Results: Among a total of 405 specimens, the distribution of cases for each category was, 44 (11%) for ND, 204 (50%) for B category, 40 (10%) for AUS/FLUS, 36 (9%) for FN/SFN, 24 (6%) for SFM and 57 (14%) for M categories. 153 cases have a histological diagnosis. The ratio of surgery was 23% in ND, 16% in the B, 45% for AUS/FLUS, 75% for SFN/FN and 92% for SFM and 75% in M categories; Conclusions: The data underlines the high ROM values in paediatric population which might be clinically meaningful. The high rate of malignancy of the cohort of operated patients (50%) also underlines the need of better preoperative indicators for stratification. Considering that more than half of the nodules in AUS/FLUS category were benign, direct surgery recommendation could be questionable as proposed in ATA 2015 guidelines.info:eu-repo/semantics/publishedVersio