68 research outputs found
Evolving localizations in reaction-diffusion cellular automata
We consider hexagonal cellular automata with immediate cell neighbourhood and
three cell-states. Every cell calculates its next state depending on the
integral representation of states in its neighbourhood, i.e. how many
neighbours are in each one state. We employ evolutionary algorithms to breed
local transition functions that support mobile localizations (gliders), and
characterize sets of the functions selected in terms of quasi-chemical systems.
Analysis of the set of functions evolved allows to speculate that mobile
localizations are likely to emerge in the quasi-chemical systems with limited
diffusion of one reagent, a small number of molecules is required for
amplification of travelling localizations, and reactions leading to stationary
localizations involve relatively equal amount of quasi-chemical species.
Techniques developed can be applied in cascading signals in nature-inspired
spatially extended computing devices, and phenomenological studies and
classification of non-linear discrete systems.Comment: Accepted for publication in Int. J. Modern Physics
Pressure support ventilation attenuates ventilator-induced protein modifications in the diaphragm
OnLine Journal Article Number : R116 The electronic version of this article is the complete one and can be found online at: http://ccforum.com/content/12/5/R116International audienceINTRODUCTION: Controlled mechanical ventilation (CMV) induces profound modifications of diaphragm protein metabolism, including muscle atrophy and severe ventilator-induced diaphragmatic dysfunction. Diaphragmatic modifications could be decreased by spontaneous breathing. We hypothesized that mechanical ventilation in pressure support ventilation (PSV), which preserves diaphragm muscle activity, would limit diaphragmatic protein catabolism. METHODS: Forty-two adult Sprague-Dawley rats were included in this prospective randomized animal study. After intraperitoneal anesthesia, animals were randomly assigned to the control group or to receive 6 or 18 hours of CMV or PSV. After sacrifice and incubation with 14C-phenylalanine, in vitro proteolysis and protein synthesis were measured on the costal region of the diaphragm. We also measured myofibrillar protein carbonyl levels and the activity of 20S proteasome and tripeptidylpeptidase II. RESULTS: Compared with control animals, diaphragmatic protein catabolism was significantly increased after 18 hours of CMV (33%, P = 0.0001) but not after 6 hours. CMV also decreased protein synthesis by 50% (P = 0.0012) after 6 hours and by 65% (P < 0.0001) after 18 hours of mechanical ventilation. Both 20S proteasome activity levels were increased by CMV. Compared with CMV, 6 and 18 hours of PSV showed no significant increase in proteolysis. PSV did not significantly increase protein synthesis versus controls. Both CMV and PSV increased protein carbonyl levels after 18 hours of mechanical ventilation from +63% (P < 0.001) and +82% (P < 0.0005), respectively. CONCLUSIONS: PSV is efficient at reducing mechanical ventilation-induced proteolysis and inhibition of protein synthesis without modifications in the level of oxidative injury compared with continuous mechanical ventilation. PSV could be an interesting alternative to limit ventilator-induced diaphragmatic dysfunction
Response to Recruitment Maneuver Influences Net Alveolar Fluid Clearance in Acute Respiratory Distress Syndrome
Background: Alveolar fluid clearance is impaired in the majority of patients with acute respiratory distress syndrome (ARDS). Experimental studies have shown that a reduction of tidal volume increases alveolar fluid clearance. This study was aimed at assessing the impact of the response to a recruitment maneuver (RM) on net alveolar fluid clearance. Methods: In 15 patients with ARDS, pulmonary edema fluid and plasma protein concentrations were measured before and after an RM, consisting of a positive end-expiratory pressure maintained 10 cm H 2 O above the lower inflection point of the pressure-volume curve during 15 min. Cardiorespiratory parameters were measured at baseline (before RM) and 1 and 4 h later. RM-induced lung recruitment was measured using the pressure-volume curve method. Net alveolar fluid clearance was measured by measuring changes in bronchoalveolar protein concentrations before and after RM. Results: In responders, defined as patients showing an RMinduced increase in arterial oxygen tension of 20% of baseline value or greater, net alveolar fluid clearance (19 ŘŽ 13%/h) and significant alveolar recruitment (113 ŘŽ 101 ml) were observed. In nonresponders, neither net alveolar fluid clearance (ŘŠ24 ŘŽ 11%/h) nor alveolar recruitment was measured. Responders and nonresponders differed only in terms of lung morphology: Responders had a diffuse loss of aeration, whereas nonresponders had a focal loss of aeration, predominating in the lower lobes. Conclusion: In the absence of alveolar recruitment and improvement in arterial oxygenation, RM decreases the rate of alveolar fluid clearance, suggesting that lung overinflation may be associated with epithelial dysfunction
Management of lower urinary tract fibroepithelial polyps in children
Introduction
Fibroepithelial polyps (FEP) of the lower urinary tract are relatively common in adults but rare in children, with fewer than 250 cases reported in the literature to date.
Objective
The aim of this study was to address the experience of FEP management in children.
Study design
A retrospective multicenter review was undertaken in children with defined FEP of the lower urinary tract managed between 2008 and 2018. The data at 18 pediatric surgery centers were collected. Their demographic, radiological, surgical, and pathological information were reviewed.
Results
A total of 33 children (26 boys; 7 girls) were treated for FEP of the lower urinary tract at 13 centers. The most common presentation was urinary outflow as hematuria (41%), acute urinary retention (25%), dysuria (19%), or urinary infections (28%). A prenatal diagnosis was made for three patients with hydronephrosis. Almost all of the children (94%) underwent ultrasound imaging of the urinary tract as the first diagnostic examination, 23 (70%) of them also either had an MRI (15%), cystourethrography (25%), computerized tomography (6%), or cystoscopy (45%). Two of these children (6%) had a biopsy prior to the surgery. The median preoperative delay was 7.52 (range: 1–48) months. Most of the patients were treated endoscopically, although four (12.1%) had open surgery and two (6.1%) had an additional incision for specimen extraction. The median hospital stay was 1.5 (range: 1–10) days. There were no recurrences and no complications after a median follow-up of 13 (range: 1–34) months.
Discussion
The main limitation of our study is the retrospective design, although it is the largest one for this pathology.
Conclusion
This series supports sonography as the most suitable diagnosis tool before endoscopy to confirm the diagnosis and to perform the resection for most FEP in children. This report confirms the recognized benign nature in the absence of recurrences
Etiopathogènie et traitements de quatre malformations congénitales curables en anténatal
DIJON-BU MĂ©decine Pharmacie (212312103) / SudocSudocFranceF
Utilisation du mélange oxygène-protoxyde d'azote aux urgences chirurgicales pédiatriques du CHU de Dijon (à la lumière d'une expérience de 11 ans)
DIJON-BU MĂ©decine Pharmacie (212312103) / SudocSudocFranceF
Traitement des kystes solitaires du rein chez l'enfant
DIJON-BU MĂ©decine Pharmacie (212312103) / SudocSudocFranceF
Ant Colony Optimisation for Exploring Logical Gene-Gene Associations in Genome Wide Association Studies
Abstract. In this paper a search for the logical variants of gene-gene interactions in genome-wide association study (GWAS) data using ant colony optimisation is proposed. The method based on stochastic algorithms is tested on a large established database from the Wellcome Trust Case Control Consortium and is shown to discover logical operations between combinations of single nucleotide polymorphisms that can discriminate Type II diabetes. A variety of logical combinations are explored and the best discovered associations are found within reasonable computational time and are shown to be statistically significant
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