468 research outputs found
Development and Experimentation of a CubeSat Magnetic Attitude Control System Testbed
For CubeSats requiring high pointing accuracy and slewing agility, ground-based hardware-in-the-loop simulations are strongly demanded to test and validate spacecraft subsystems and guidance, navigation, and control algorithms. In this article, a magnetic attitude control system (MACS) testbed for a CubeSat is developed utilizing a spherical air bearing and a Helmholtz cage. The design, development, and verification procedure of MACS is presented together with different test scenarios. To generate enough torque with the magnetorquer system in the dynamic testbed, the Helmholtz coil system of the testbed has driven to provide an augmented magnetic field. As an example of experimentation, the B-dot control algorithm was implemented to dissipate the angular momentum of the dynamic MACS testbed. The experimental results were compared with those of the numerical simulations
Ex vivo experimental study on the Thulium laser system : new horizons for interventional endoscopy (with videos)
BACKGROUND AND STUDY AIMS: The Thulium laser system (TLS) is an emerging interventional tool adopted in many surgical specialties. Its 2.0-\u3bcm wavelength allows precise coagulation (0.2\u200a-\u200a0.4\u200amm in depth) and cutting, limiting the possibilities of collateral injuries. We tested the impact of the TLS for gastric endoscopic submucosal dissection (ESD) and per oral endoscopic myotomy (POEM) ex vivo in pigs. MATERIALS AND METHODS: Ex vivo porcine stomach and esophagus models underwent 2 POEMs, and 3 ESDs (mean diameter 3.5\u200acm) with TLS using a 272-\ub5m and a 365-\ub5m thick optical fibers. Both continuous and pulsed laser emission were evaluated. Subsequent histopathological analysis was performed by an expert GI pathologist on the whole porcine models. RESULTS: Complete POEMs and gastric ESDs were successfully performed in all cases in 30 to 70 and 15 to 20 minutes. Both optical fibers were equally effective and precise. The best power output for mucosal incision was 25 to 30\u200aW during ESD and 25\u200aW for POEM using continuous laser emission. During submucosal dissection and tunneling the favorite power output was 20\u200aW and 15 to 20\u200aW, respectively, operating in continuous mode. No transmural perforation occurred throughout the operations and histopathology confirmed the absence of accidental muscular layer damage. CONCLUSIONS: The TLS stands out as a precise and manageable instrument in ex vivo models. This technique appears to be a promising tool for advanced interventional endoscopy
Maternal Antibiotic-Induced Early Changes in Microbial Colonization Selectively Modulate Colonic Permeability and Inducible Heat Shock Proteins, and Digesta Concentrations of Alkaline Phosphatase and TLR-Stimulants in Swine Offspring
Elevated intake of high energy diets is a risk factor for the development of metabolic diseases and obesity. High fat diets cause alterations in colonic microbiota composition and increase gut permeability to bacterial lipopolysaccharide, and subsequent low-grade chronic inflammation in mice. Chronic inflammatory bowel diseases are increasing worldwide and may involve alterations in microbiota-host dialog. Metabolic disorders appearing in later life are also suspected to reflect changes in early programming. However, how the latter affects the colon remains poorly studied. Here, we hypothesized that various components of colonic physiology, including permeability, ion exchange and protective inducible heat shock proteins (HSP) are influenced in the short- and long-terms by early disturbances in microbial colonization. The hypothesis was tested in a swine model. Offspring were born to control mothers (n = 12) or mothers treated with the antibiotic (ATB) amoxicillin around parturition (n = 11). Offspring were slaughtered between 14 and 42 days of age to study short-term effects. For long-term effects, young adult offspring from the same litters consumed a normal or a palm oil-enriched diet for 4 weeks between 140 and 169 days of age. ATB treatment transiently modified maternal fecal microbiota although the minor differences observed for offspring colonic microbiota were nonsignificant. In the short-term, consistently higher HSP27 and HSP70 levels and transiently increased horseradish peroxidase permeability in ATB offspring colon were observed. Importantly, long-term consequences included reduced colonic horseradish peroxidase permeability, and increased colonic digesta alkaline phosphatase (AP) and TLR2- and TLR4-stimulant concentrations in rectal digesta in adult ATB offspring. Inducible HSP27 and HSP70 did not change. Interactions between early ATB treatment and later diet were noted for paracellular permeability and concentrations of colonic digesta AP. In conclusion, our data suggest that early ATB-induced changes in bacterial colonization modulate important aspects of colonic physiology in the short- and longterms
Emotional susceptibility trait modulates insula responses and functional connectivity in flavor processing
The present study aimed at investigating the relationship between Emotional Susceptibility (ES), an aspect of the personality trait Neuroticism, and individual differences in the neural responses in anterior insula to primary sensory stimuli colored by affective valence, i.e., distasting or pleasantly tasting oral stimuli. In addition, it was studied whether intrinsic functional connectivity patterns of brain regions characterized by such differential responses could be related to ES. To this purpose 25 female participants underwent functional magnetic resonance imaging scanning, while being involved in a flavor experiment. During the experiment, flavor stimuli were administered consisting of small amounts of liquid with a different affective valence: neutral, pleasant, unpleasant. The results showed that individual differences in ES trait predicted distinct neural activity patterns to the different stimulus conditions in a region of left anterior insula that a previous meta-analysis revealed to be linked with olfacto-gustatory processing. Specifically, low ES was associated with enhanced neural responses to both pleasant and unpleasant stimuli, compared to neutral stimuli. By contrast, high ES participants showed equally strong neural responses to all types of stimuli without differentiating between the neutral and affective stimuli. Finally, during a task-free state, high ES trait appeared also to be related to decreased intrinsic functional connectivity between left anterior insula and left cerebellum. Our findings show that individual differences in ES are associated with differential anterior insula responses to primary sensory (flavor) stimuli as well as to intrinsic functional cortico-cerebellar connectivity, the latter suggesting a basis in the brain intrinsic functional architecture of the regulation of emotional experiences
Proposta de uso da vazão de referência mensal em substituição à anual no Rio Dourados.
bitstream/item/145320/1/CT201636.pd
Terminal ileum ileoscopy and histology in patients undergoing high-definition colonoscopy with virtual chromoendoscopy for chronic nonbloody diarrhea : a prospective, multicenter study
Background and aims: Ileo-colonoscopy is the procedure of choice for chronic nonbloody diarrhea (CNBD) of unknown origin. Histological evaluation at different colonic sites is mandatory to assess the presence of microscopic colitis. However, the value of routine ileal biopsy on normal-appearing mucosa as assessed by means of standard-resolution white-light ileoscopy is controversial given its reported low diagnostic yield. Hence, we have assessed for the first time the accuracy of retrograde ileoscopy using high-definition and dyeless chromoendoscopy (HD + DLC), thereby calculating the impact and cost of routine ileal biopsy in CNBD. Methods: Patients with CNBD of unknown origin were prospectively enrolled for ileo-colonoscopy with HD + DLC at five referral centers. Multiple biopsies were systematically performed on each colorectal segment and in the terminal ileum for histopathological analysis. Results: Between 2014 and 2017, 546 consecutive patients were recruited. Retrograde ileoscopy success rate was 97.6%. A total of 492 patients (mean age: 53 \ub1 18 years) fulfilled all the inclusion criteria: Following endoscopic and histopathological work-up, 7% had lymphoid nodular hyperplasia and 3% had isolated ileitis. Compared to the histopathology as the gold standard, retrograde ileoscopy with HD + DLC showed 93% sensitivity, 98% specificity and 99.8% negative predictive value. In patients with normal ileo-colonoscopy, ileum histology had no diagnostic gain and resulted in a cost of US $26.5 per patient. Conclusions: Retrograde ileoscopy with HD + DLC predicts the presence of ileitis in CNBD with excellent performance. The histopathological evaluation of the terminal ileum is the gold standard for the diagnostic assessment of visible lesions but has no added diagnostic value in CNBD patients with negative ileo-colonoscopy inspection using modern endoscopic imaging techniques
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Positive Youth Development: Parental Warmth, Values, and Prosocial Behavior in 11 Cultural Groups
The current cross-cultural study aimed to extend research on parenting and children\u27s prosocial behavior by examining relations among parental warmth, values related to family obligations (i.e., children\u27s support to and respect for their parents, siblings, and extended family), and prosocial behavior during the transition to adolescence (from ages 9 to 12). Mothers, fathers, and their children (N = 1107 families) from 8 countries including 11 cultural groups (Colombia; Rome and Naples, Italy; Jordan; Kenya; the Philippines; Sweden; Thailand; and African Americans, European Americans, and Latin Americans in the United States) provided data over 3 years in 3 waves (M-age of child in wave 1 = 9.34 years, SD = 0.75; 50.5% female). Overall, across all 11 cultural groups, multivariate change score analysis revealed positive associations among the change rates of parental warmth, values related to family obligations, and prosocial behavior during late childhood (from age 9 to 10) and early-adolescence (from age 10 to 12). In most cultural groups, more parental warmth at ages 9 and 10 predicted steeper mean-level increases in prosocial behavior in subsequent years. The findings highlight the prominent role of positive family context, characterized by warm relationships and shared prosocial values, in fostering children\u27s positive development in the transition to adolescence. The practical implications of these findings are discussed
Extensive small-bowel Crohn's disease detected by the newly introduced 360° panoramic viewing capsule endoscopy system
IL-33 promotes recovery from acute colitis by inducing miR-320 to stimulate epithelial restitution and repair
Defective and/or delayed wound healing has been implicated in the pathogenesis of several chronic inflammatory disorders, including inflammatory bowel disease (IBD). The resolution of inflammation is particularly important in mucosal organs, such as the gut, where restoration of epithelial Barrier function is critical to reestablish homeostasis with the interfacing microenvironment. Although IL-33 and its receptor ST2/ILRL1 are known to be increased and associated with IBD, studies using animal models of colitis to address the mechanism have yielded ambiguous results, suggesting both pathogenic and protective functions. Unlike those previously published studies, we focused on the functional role of IL-33/ST2 during an extended (2-wk) recovery period after initial challenge in dextran sodium sulfate (DSS)-induced colitic mice. Our results show that during acute, resolving colitis the normal function of endogenous IL-33 is protection, and the lack of either IL-33 or ST2 impedes the overall recovery process, while exogenous IL-33 administration during recovery dramatically accelerates epithelial restitution and repair, with concomitant improvement of colonic inflammation. Mechanistically, we show that IL-33 stimulates the expression of a network of microRNAs (miRs) in the Caco2 colonic intestinal epithelial cell (IEC) line, especially miR-320, which is increased by >16-fold in IECs isolated from IL-33–treated vs. vehicle-treated DSS colitic mice. Finally, IL-33–dependent in vitro proliferation and wound closure of Caco-2 IECs is significantly abrogated after specific inhibition of miR-320A. Together, our data indicate that during acute, resolving colitis, IL-33/ST2 plays a crucial role in gut mucosal healing by inducing epithelial-derived miR-320 that promotes epithelial repair/restitution and the resolution of inflammation
Sanitary housing conditions modify the performance and behavioural response of weaned pigs to feed- and housing-related stressors
Pigs are confronted with changes in farming practices that may affect performance and animal well-being. The sanitary conditions of the farm can have an impact on the ability of pigs to adapt to these changes. This study aimed to analyse how weaned pigs respond to common farming practices of changes in diet and housing in terms of performance, health and behaviour, and how these responses are affected by the sanitary housing conditions, qualified here as good or poor. At weaning at 4 weeks of age, 20 piglets were assigned to 10 blocks of two littermates and each pig within a litter was randomly assigned to one of two sanitary conditions. Pigs were housed individually and received a starter diet. A diet change occurred on day 12 post weaning (starter to weaner diets) and pigs were transferred to the grower unit on day 33 post weaning and continued to receive the weaner diet. From 43 days post weaning, pigs were offered a grower diet and were vaccinated against swine influenza on day 47 and 61 post weaning. On the basis of this design, three post-weaning phases were identified: phase I from day 1 to 11 (post weaning), phase II from day 12 to 32 (after the diet change) and phase III from day 33 to 42 (after the housing change). Individual BW was measured every 3 days, and feed refusals and faecal scores were recorded on a daily basis. Behavioural observations were performed during 28 days by using the instantaneous scan sampling method. Individual blood samples were collected at the end of each phase to analyse the plasma concentration of haptoglobin and on day 68 post weaning to analyse the anti-influenza immunoglobulins G (IgG). Poor sanitary conditions resulted in a decrease in daily gain, feed intake and gain to feed ratio of, respectively, 11%, 5% and 7% (P < 0.05). Pigs in poor sanitary conditions had higher faecal scores (P < 0.05), tended to have higher plasma haptoglobin concentration in phase II (P = 0.06) and had a higher anti-influenza IgG titre (P = 0.11). The diet change affected performance and behavioural responses of pigs in poor but not in good sanitary conditions. Housing change resulted in a 30% decrease in growth and an increase in behaviour oriented towards exploration and excitement. The results of this study show an effect of sanitary conditions on the responses of pigs to a diet change, whereas those to a housing change were little affected by the sanitary conditions
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