611 research outputs found

    Selectivity of interaction of spin-labelled lipids with peripheral proteins bound to dimyristoylphosphatidylglycerol bilayers, as determined by ESR spectroscopy.

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    The selectivity of interaction between spin-labelled lipids and the peripheral proteins, apocytochrome c, cytochrome c, lysozyme and polylysine has been studied using ESR spectroscopy. Derivatives of phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylserine (PS), phosphatidylinositol (PI), diphosphatidylglycerol (CL) and diacylglycerol (DG) spin-labelled at the 5-C atom position of the sn-2 chain were used to study the association of these proteins with bilayers of dimyristoylphosphatidylglycero. Binding of the proteins increased the outer hyperfine splitting in the ESR spectra of the lipid spin labees to an extent which depended both on the spin-labelled lipid species involved and on the particular protein. The order of selectivity for apocytochrome c follows the sequence: PI−>CL−≈DG PS−>PC±>PG−>PE±. The selectivity pattern for cytochrome c is: PI−>PG−>CL−>DG PS−≈PC±>PE±; for lysozyme is: CL−>PG−>DG PE−>PC±PS−>PI−; and that for polylysine is: CL−>PS−⩾PG−>PI−>PC±>DG PE+-. The overall strength of interaction is in the order lysozyme>cytochrome c>apcoytochrome c, for equivalent binding, and the spread of the selectivity for the different proteins is in the reverse order. Assuming fast exchange for the ESR spectra of the 5-C atom labelled lipids, the relative association constants of the different labels with the different proteins have been estimated

    Survival following surgical treatment for anorectal melanoma seems similar for local excision and extensive resection regardless of nodal involvement

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    Background: Anorectal melanoma is a rare malignancy with a dismal prognosis. The purpose of this study was to investigate whether the survival per stage is influenced by the surgical approaches (local excision or extensive resection), to assess prognostic factors of survival, and to answer the question whether the practiced surgical approaches changed over time. Methods: Dutch cancer registry organizations (IKNL and PALGA) were queried for all patients with a diagnosis of anorectal melanoma (1989-2019). Patients with disseminated disease at diagnosis were excluded. Survival outcomes were compared for the two surgical approaches stratified by stage (clinical node negative (cN0) and clinical node positive (cN+)) and date of diagnosis. Results: A total of 103 patients were included in this study. In both cN0 and cN+ patients the surgical strategy did not significantly influence survival (cN0: 21.7% 5-year survival, median 25 months for local excision versus 13.7% 5-year survival, median 17 months for extensive resection (p = 0.228), cN+: 11.1% 5-year survival for local excision, median 17 months versus 8.7% 5-year survival, median 14 months for extensive resection (p = 0.741)). Stage and date of diagnosis showed to be prognostic factors of survival. The ratio between the two surgical approaches was unchanged over three decades. Conclusions: Extensive resection does not seem to improve survival in both cN0 and cN+ anorectal melanoma patients compared to local excision. However in the past three decades no shift towards local excision has been found. cN+ stage and an older date of diagnosis are predictors for worse survival

    An Experimental Investigation Into the Performance of a Flush Water-Jet Inlet

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    An experimental investigation of the flow within a generic flush type water-jet inlet has been carried out to identify the principal flow features and provide a basis for development of computational fluid dynamics (CFD) models. Tests were performed in a cavitation tunnel with the model inlet fitted to the test section ceiling, and effects of thickening the ingested tunnel wall boundary layer were investigated. The model was fitted with a range of instrumentation to investigate the ramp pressure distribution and boundary layer development, lip incidence, and pump face flow properties. Observations of lip and duct cavitation inception and behavior were also made. The results showed the inlet performance to be generally improved with the ingestion of a thicker boundary layer. The thickened boundary layer significantly reduced ramp boundary layer separation and distortion of flow at the notional pump face. However, a greater range of lip incidence occurred with the thickened boundary layer with consequent greater likelihood of lip separation and cavitation occurrence. Ideal lip incidence and pump face flow uniformity occurred at flow parameters significantly different from those for ideal pump face pressure recovery. Large developed cavities on the inlet lip were observed for a range of conditions typical of conventional high-speed vessel operation

    The immediate impact of the coronavirus disease 2019 (COVID-19) pandemic on burn-out, work-engagement, and surgical training in the Netherlands

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    BACKGROUND: The coronavirus disease 2019 pandemic led to major changes in health care and education options for all health care employees. The aim of this study is to achieve insight into coronavirus disease-care participation of surgical residents in the Netherlands, the impact of coronavirus disease 2019 on the experienced quality of surgical training, and the influence on Burn-out and Work Engagement compared with the non-coronavirus disease 2019 period in January 2020.METHODS: In this study, we have conducted 2 digital surveys immediately before and 2 months after the start of the coronavirus disease 2019 pandemic. We surveyed a validated Dutch questionnaire 'Utrecht Burn-out Scale,' derived from the Maslach Burn-out Inventory, and also collected the 'Utrecht Work Engagement Scale' measuring work engagement. Additionally, we describe the coronavirus disease-care participation of surgical residents, the impact on how they experienced the quality of their surgical training, and the influence on 'Burn-out and Work Engagement' compared with the pre-coronavirus disease 2019 period for surgical residents in the Netherlands.RESULTS: In January 2020, a total of 317 residents completed the online survey, and in April 2020, a total of 313 residents completed the online survey. Of the responders, 48.6%, in April, participated in coronavirus disease-care in both the coronavirus disease ward as well as the coronavirus disease intensive care unit. Residents experienced that the coronavirus disease 2019 influenced their surgical training in 85.2% of responders. In only 5% of the residents did the pandemic not affect the exposure to surgical training in the operating theater. More burn-out symptoms were noted amongst coronavirus disease ward deployed residents versus no coronavirus disease ward deployment, (16.0% vs 7.6%, P = .06). The Work-Engagement questionnaire showed a significantly lower work engagement score of 4.2 for residents who were deployed in a coronavirus disease-care intensive care unit versus a score of 4.6 for residents scheduled in a coronavirus disease ward (P = .02).CONCLUSION: This study shows a significant impact of the first months of the coronavirus disease 2019 pandemic on the Dutch surgical trainee program, with a major redistribution of residents with a decrease of surgical exposure and education. We emphasize the need for adequate guidance of all surgical residents and potentially lengthening the surgical training program.</p

    Phospholipid Motional Characteristics in a Dry Biological System

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    Focal Thyroid Incidentalomas on F-18-FDG PET/CT:A Systematic Review and Meta-Analysis on Prevalence, Risk of Malignancy and Inconclusive Fine Needle Aspiration

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    BackgroundThe rising demand for 18F-fluorodeoxyglucose positron emission tomography with computed tomography (18F-FDG PET/CT) has led to an increase of thyroid incidentalomas. Current guidelines are restricted in giving options to tailor diagnostics and to suit the individual patient.ObjectivesWe aimed at exploring the extent of potential overdiagnostics by performing a systematic review and meta-analysis of the literature on the prevalence, the risk of malignancy (ROM) and the risk of inconclusive FNAC (ROIF) of focal thyroid incidentalomas (FTI) on 18F-FDG PET/CT.Data SourcesA literature search in MEDLINE, Embase and Web of Science was performed to identify relevant studies.Study SelectionStudies providing information on the prevalence and/or ROM of FTI on 18F-FDG PET/CT in patients with no prior history of thyroid disease were selected by two authors independently. Sixty-one studies met the inclusion criteria.Data AnalysisA random effects meta-analysis on prevalence, ROM and ROIF with 95% confidence intervals (CIs) was performed. Heterogeneity and publication bias were tested. Risk of bias was assessed using the quality assessment of diagnostic accuracy studies (QUADAS-2) tool.Data SynthesisFifty studies were suitable for prevalence analysis. In total, 12,943 FTI were identified in 640,616 patients. The pooled prevalence was 2.22% (95% CI = 1.90% - 2.54%, I2 = 99%). 5151 FTI had cyto- or histopathology results available. The pooled ROM was 30.8% (95% CI = 28.1% - 33.4%, I2 = 57%). 1308 (83%) of malignant nodules were papillary thyroid carcinoma (PTC). The pooled ROIF was 20.8% (95% CI = 13.7% - 27.9%, I2 = 92%).LimitationsThe main limitations were the low to moderate methodological quality of the studies and the moderate to high heterogeneity of the results.ConclusionFTI are a common finding on 18F-FDG PET/CTs. Nodules are malignant in approximately one third of the cases, with the majority being PTC. Cytology results are non-diagnostic or indeterminate in one fifth of FNACs. These findings reveal the potential risk of overdiagnostics of FTI and emphasize that the workup of FTI should be performed within the context of the patient’s disease and that guidelines should adopt this patient tailored approach

    Національні тенденції розвитку університетської освіти

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    В сучасному динамічно змінюваному світі університет - це перш за все вищий навчальний заклад, який є індикатором цивілізаційності регіону та держави. Проте у наші дні класичні університети постали перед серйозними викликами часу.В современном динамически изменяющемся мире университет - это прежде всего высшее учебное заведение, которое является индикатором цивилизационности региона и государства. Однако в наши дни классические университеты встали перед серьезными вызовами времени

    S-100B as an extra selection tool for FDG PET/CT scanning in follow-up of AJCC stage III melanoma patients

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    Background and Objectives This current study assessed the value of S-100B measurement to guide fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scanning for detecting recurrent disease in stage III melanoma patients. Methods This study included 100 stage III melanoma patients in follow-up after curative lymph node dissection. Follow-up visits included physical examination and S-100B monitoring. FDG PET/CT scanning was indicated by clinical symptoms and/or elevated S-100B. Results Of 100 patients, 13 (13%) had elevated S-100B without clinical symptoms, of whom 7 (54%) showed disease evidence upon FDG PET/CT scanning. Twenty-six patients (26%) had clinical symptoms with normal S-100B and FDG PET/CT revealed metastasis in 20 (77%). Three patients had clinical symptoms and elevated S-100B, and FDG PET/CT revealed metastasis in all three (100%). Overall, FDG PET/CT scanning revealed metastasis in 30 of the 42 patients (71.4%). For seven recurrences, elevated S-100B prompted early detection of asymptomatic disease; 10% of all asymptomatic patients in follow-up, 23% of all patients with recurrent disease. Conclusion S-100B cannot exclude recurrent disease during follow-up of stage III melanoma. However, adding S-100B measurement to standard clinical assessment can guide FDG PET/CT scanning for detecting recurrent melanoma
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