492 research outputs found
Capacity planning of prisons in the Netherlands
In this paper we describe a decision support system developed to help in assessing the need for various type of prison cells. In particular we predict the probability that a criminal has to be sent home because of a shortage of cells. The problem is modelled through a queueing network with blocking after service. We focus in particular on the new analytical method to solve
this network
An (s,Q) inventory model with remanufacturing and disposal
In this paper we analyse an (s, Q) inventory model in which used products can be remanufactured to new ones. We develop two approximations for the average costs and compare their performance with that of an approximation suggested by Muckstadt and Isaac. Next we extend the model with the option to dispose returned products and present a heuristic optimisation procedure which is checked with full enumeration
Surface modification of hydrophobic polymers for improvement of endothelial cell-surface interactions
The aim of this study is to improve the interaction of endothelial cells with polymers used in vascular prostheses. Polytetrafluoroethylene (PTFE; Teflon) films were treated by means of nitrogen and oxygen plasmas. Depending on the plasma exposure time, modified PTFE surfaces showed water-contact angles of 15¿58° versus 96° for unmodified PTFE. Electron spectroscopy in chemical analysis (ESCA) measurements revealed incorporation of both nitrogenand oxygen-containing groups into the PTFE surfaces, dependent on the plasma composition and exposure time. In-vitro biological evaluation of unmodified and modified PTFE surfaces showed that human endothelial cells, seeded from 20% human serum-containing culture medium, adhered well on to modified PTFE surfaces, but not on to unmodified films. Adhesion of endothelial cells on to expanded PTFE graft material (Gore-Tex) was also stimulated by plasma treatment of this substrate. On plasma-treated expanded PTFE, the adhering endothelial cells formed a monolayer, which covered the textured surface. The latter observation is important in view of the hemocompatibility of vascular grafts seeded with endothelial cells before implantation
Behavioural and psychological symptoms of dementia in Down syndrome: Early indicators of clinical Alzheimer's disease?
Behavioural and Psychological Symptoms of Dementia (BPSD) are a core symptom of dementia and are associated with suffering, earlier institutionalization and accelerated cognitive decline for patients and increased caregiver burden. Despite the extremely high risk for Down syndrome (DS) individuals to develop dementia due to Alzheimer's disease (AD), BPSD have not been comprehensively assessed in the DS population. Due to the great variety of DS cohorts, diagnostic methodologies, sub-optimal scales, covariates and outcome measures, it is questionable whether BPSD have always been accurately assessed. However, accurate recognition of BPSD may increase awareness and understanding of these behavioural aberrations, thus enabling adaptive caregiving and, importantly, allowing for therapeutic interventions. Particular BPSD can be observed (long) before the clinical dementia diagnosis and could therefore serve as early indicators of those at risk, and provide a new, non-invasive way to monitor, or at least give an indication of, the complex progression to dementia in DS. Therefore, this review summarizes and evaluates the rather limited knowledge on BPSD in DS and highlights its importance and potential for daily clinical practice
Effects of Ethanol and Acetaldehyde on Tight Junction Integrity: In Vitro Study in a Three Dimensional Intestinal Epithelial Cell Culture Model
Background: Intestinal barrier dysfunction and translocation of endotoxins are involved in the pathogenesis of alcoholic liver disease. Exposure to ethanol and its metabolite, acetaldehyde at relatively high concentrations have been shown to disrupt intestinal epithelial tight junctions in the conventional two dimensional cell culture models. The present study investigated quantitatively and qualitatively the effects of ethanol at concentrations detected in the blood after moderate ethanol consumption, of its metabolite acetaldehyde and of the combination of both compounds on intestinal barrier function in a three-dimensional cell culture model. Methods and Findings: Caco-2 cells were grown in a basement membrane matrix (Matrigel (TM)) to induce spheroid formation and were then exposed to the compounds at the basolateral side. Morphological differentiation of the spheroids was assessed by immunocytochemistry and transmission electron microscopy. The barrier function was assessed by the flux of FITC-labeled dextran from the basal side into the spheroids' luminal compartment using confocal microscopy. Caco-2 cells grown on Matrigel assembled into fully differentiated and polarized spheroids with a central lumen, closely resembling enterocytes in vivo and provide an excellent model to study epithelial barrier functionality. Exposure to ethanol (10-40 mM) or acetaldehyde (25-200 mu M) for 3 h, dose-dependently and additively increased the paracellular permeability and induced redistribution of ZO-1 and occludin without affecting cell viability or tight junction-encoding gene expression. Furthermore, ethanol and acetaldehyde induced lysine residue and microtubules hyperacetylation. Conclusions: These results indicate that ethanol at concentrations found in the blood after moderate drinking and acetaldehyde, alone and in combination, can increase the intestinal epithelial permeability. The data also point to the involvement of protein hyperacetylation in ethanol- and acetaldehyde-induced loss of tight junctions integrity
Kunsteducatie in de 21ste Eeuw:Geavanceerde Afspraken, Innovatie Organisatievormen en Nieuwe Werkrelaties
Heterogeneity in glucose response curves during an oral glucose tolerance test and associated cardiometabolic risk
We aimed to examine heterogeneity in glucose response curves during an oral glucose tolerance test with multiple measurements and to compare cardiometabolic risk profiles between identified glucose response curve groups. We analyzed data from 1,267 individuals without diabetes from five studies in Denmark, the Netherlands and the USA. Each study included between 5 and 11 measurements at different time points during a 2-h oral glucose tolerance test, resulting in 9,602 plasma glucose measurements. Latent class trajectories with a cubic specification for time were fitted to identify different patterns of plasma glucose change during the oral glucose tolerance test. Cardiometabolic risk factor profiles were compared between the identified groups. Using latent class trajectory analysis, five glucose response curves were identified. Despite similar fasting and 2-h values, glucose peaks and peak times varied greatly between groups, ranging from 7-12 mmol/L, and 35-70 min. The group with the lowest and earliest plasma glucose peak had the lowest estimated cardiovascular risk, while the group with the most delayed plasma glucose peak and the highest 2-h value had the highest estimated risk. One group, with normal fasting and 2-h values, exhibited an unusual profile, with the highest glucose peak and the highest proportion of smokers and men. The heterogeneity in glucose response curves and the distinct cardiometabolic risk profiles may reflect different underlying physiologies. Our results warrant more detailed studies to identify the source of the heterogeneity across the different phenotypes and whether these differences play a role in the development of type 2 diabetes and cardiovascular disease
Real patient learning integrated in a preclinical block musculoskeletal disorders. Does it make a difference?
Although musculoskeletal disorders are the most common reason for general practitioner visits, training did not keep pace. Implementation of learning from patients with rheumatologic disorders linked together with the teaching of theoretical knowledge in the preclinical medical education might be an important step forward in the improvement of quality of care for these patients. The Leiden Medical School curriculum has implemented two non-obligatory real patient learning (RPL) practicals integrated within the preclinical block musculoskeletal disorders. This study investigates the educational effectiveness of the practicals, the expectations students have of RPL, and students’ satisfaction. Participants’ grades on the end-of-block test served as the test results of the educational effectiveness of the practicals and were compared with those of the non-participants. Qualitative data was collected by means of questionnaires generated by focus groups. The participants in practicals scored significantly higher at the end-of-block test. The expected effects of the contact with real patients concerned positive effects on cognition and skills. ‘Contextualizing of the theory’, ‘better memorizing of clinical pictures’, and ‘understanding of the impact of the disease’ were the most frequently mentioned effects of the practicals. Overall, the participants were (very) enthusiastic about this educational format. The RPL practicals integrated within a preclinical block musculoskeletal disorders are a valuable addition to the Leiden medical curriculum. This relatively limited intervention exhibits a strong effect on students’ performance in tests. Future research should be directed towards the long-term effects of this intervention
ベルト・モリゾと日本美術(1) : 扇・団扇のジャポニスムから1890年ビングの「日本版画展」まで
textabstractA human genomic fragment comprising the cellular retinoic acid binding protein (CRABP) gene was isolated. By using a panel of somatic cell hybrids, this gene could be assigned to human chromosome 15. Subsequently, a possible involvement of the CRABP gene in translocation (15;17) (q22;q11) positive acute promyelocytic leukemia (APL) was investigated. Although transposition of the CRABP gene could be demonstrated, we did not observe any gross CRABP rearrangement in a series of primary APL patients, nor in the acute myeloblastic leukemia cell line HL-60. Thus, the observed lack of CRABP expression in these leukemic cells may not be caused by disruption of its gene. CRABP maps to the region 15q22-qter
Acute epiglottitis as the initial presentation of pediatric Systemic Lupus Erythematosus
We report a case of a 5-year old girl, who initially presented with acute epiglottitis, sepsis and multi-organ failure. She was subsequently diagnosed as having Systemic Lupus Erythematosus. To the best of our knowledge, this article describes the first case of Haemophilus influenzae type f epiglottitis as the initial presentation of SLE in childhood
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