251 research outputs found
Role of stress-assisted martensite in the design of strong ultrafine-grained duplex steels
This work explains the occurrence of transformation-induced plasticity via
stress-assisted martensite, when designing ultrafine-grained duplex steels. It
is found that, when the austenite is reduced to a fine scale of about 300 nm,
the initial deformation-induced microstructure can be dominated by parallel
lamellae of epsilon martensite or mechanical twinning, which cannot efficiently
provide nucleation sites for strain-induced martensite. Hence, alpha martensite
nucleation occurs independently by a stress-assisted process that enhances
transformation-induced plasticity in ultrafine-grained austenite. This
metallurgical principle was validated experimentally by using a combination of
transmission Kikuchi diffraction mapping, transmission electron microscopy, and
atom probe microscopy, and demonstrated theoretically by the thermodynamics
model of stress-assisted martensite.The authors acknowledge the facilities, and the scientific and technical assistance of the
Australian Microscopy & Microanalysis Research Facility (ammrf.org.au) node at
Sydney Microscopy & Microanalysis, at the University of Sydney.This is the accepted manuscript. The final version is available from Elsevier at http://www.sciencedirect.com/science/article/pii/S1359645414006958
Dietary intake in children on the autism spectrum is altered and linked to differences in autistic traits and sensory processing styles
Diets of children and adolescents on the autism spectrum often differ when compared to their non-autistic peers. Most dietary studies have been limited by small sample sizes and rarely assess the heterogeneity of autism. Addressing this gap, this study compared the anthropometrics, dietary composition, dietary quality, and food variety of 154 Australian children and adolescents on the spectrum and 213 non-autistic children (71 siblings and 142 unrelated controls). Beyond the case-control approach, within-group comparisons assessed the influence of autism clinical presentations and sensory processing styles on body mass index (BMI) and measures of dietary intake among those on the spectrum. In this word first study of diet that included between-group comparisons with non-autistic peers (siblings and an unrelated comparison group) and within-autism group comparisons, we found that children on the spectrum consumed limited variety and lower quality of food and non-autistic siblings also ate comparably higher levels of energy-dense, nutrient poor food, and less diary. This may be due to autistic traits influencing family's diets or shared sensory sensitivities driving dietary intake. Within the autism group, higher autistic traits were associated with lower BMIs and a specific dietary pattern higher in simple carbohydrates and lower in unprocessed protein. Contrastingly, greater sensitivity to sensory stimuli was associated with a healthier diet. Increased age was linked to more varied diets but also diets higher in saturated fats and energy-dense, nutrient poor foods. Overall, this research highlights that potential mediators of dietary intake, such as familial influences, autistic traits, sensory processing styles, age and sex, need to be considered when assessing diet in the autistic population. Lay Summary: In this study of dietary differences linked to autism, children, and teenagers on the spectrum ate fewer different foods and were less likely to eat recommended amounts of fruits and vegetables when compared to non-autistic siblings and unrelated children and teenagers. There were also family differences, in that those on the spectrum and their siblings ate more unhealthy foods and less dairy. Among those on the spectrum, dietary differences were linked to age, sex, autistic traits and sensory processing styles
Comparison of intravenous lignocaine and esmolol in attenuating hemodynamic response and cough reflex during extubation in hypertensive patients under general anaesthesia
Tracheal extubation carries higher complication rates compared to intubation during
general anaesthesia (GA). Thus, various drugs are used to attenuate hemodynamic
responses and cough reflex during extubation. We investigated if intravenous
(IV) lignocaine and esmolol, given prior extubation, was able to achieve that in
hypertensive patients under GA. In this prospective, double-blinded, randomised
controlled study, 68 hypertensive patients on treatment undergoing GA were
analysed. Group L received IV lignocaine 1 mg/kg while Group E received IV
esmolol 1.5 mg/kg, 2 minutes before extubation. Heart rate (HR), systolic blood
pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP)
were recorded at the following interval: before study drug administration (T-0),
prior extubation (T-1), 1 minute (T-2), 3 minutes (T-3), 5 minutes (T-4) and 10
minutes (T-5) post-extubation. Group L showed significantly increase in HR at T-2
while SBP and MAP increased significantly from T-1 until T-5. Group E showed
a significant reduction in HR at T-1 up to T-5 and significantly lower HR at T-1
and T-2 compared to Group L. Group E showed stable SBP, DBP and MAP at
all intervals. In conclusion, IV esmolol at 1.5 mg/kg was able to attenuate the
hemodynamic response more pronounced when compared to IV lignocaine at
1 mg/kg from extubation stress in patients with hypertension on treatment. Both
lignocaine and esmolol were equally effective in suppressing cough reflex during
extubation
HRCT quantification of bronchiectasis: a functional-morphologic study
published_or_final_versio
The intestinal virome in children with cystic fibrosis differs from healthy controls.
Intestinal bacterial dysbiosis is evident in children with cystic fibrosis (CF) and intestinal viruses may be contributory, given their influence on bacterial species diversity and biochemical cycles. We performed a prospective, case-control study on children with CF and age and gender matched healthy controls (HC), to investigate the composition and function of intestinal viral communities. Stool samples were enriched for viral DNA and RNA by viral extraction, random amplification and purification before sequencing (Illumina MiSeq). Taxonomic assignment of viruses was performed using Vipie. Functional annotation was performed using Virsorter. Inflammation was measured by calprotectin and M2-pyruvate kinase (M2-PK). Eight CF and eight HC subjects were included (50% male, mean age 6.9 ± 3.0 and 6.4 ± 5.3 years, respectively, p = 0.8). All CF subjects were pancreatic insufficient. Regarding the intestinal virome, no difference in Shannon index between CF and HC was identified. Taxonomy-based beta-diversity (presence-absence Bray-Curtis dissimilarity) was significantly different between CF and HC (R2 = 0.12, p = 0.001). Myoviridae, Faecalibacterium phage FP Taranis and unclassified Gokushovirinae were significantly decreased in CF compared with HC (q<0.05). In children with CF (compared to HC), the relative abundance of genes annotated to (i) a peptidoglycan-binding domain of the peptidoglycan hydrolases (COG3409) was significantly increased (q<0.05) and (ii) capsid protein (F protein) (PF02305.16) was significantly decreased (q<0.05). Picornavirales, Picornaviridae, and Enterovirus were found to positively correlate with weight and BMI (r = 0.84, q = 0.01). Single-stranded DNA viruses negatively correlated with M2-PK (r = -0.86, q = 0.048). Children with CF have an altered intestinal virome compared to well-matched HC, with both taxonomic and predicted functional changes. Further exploration of Faecalibacterium phages, Gokushovirinae and phage lysins are warranted. Intestinal viruses and their functions may have important clinical implications for intestinal inflammation and growth in children with CF, potentially providing novel therapeutic targets
Identification and validation of clinical predictors for the risk of neurological involvement in children with hand, foot, and mouth disease in Sarawak
Background: Human enterovirus 71 (HEV71) can cause Hand, foot, and mouth disease (HFMD) with neurological
complications, which may rapidly progress to fulminant cardiorespiratory failure, and death. Early recognition of children
at risk is the key to reduce acute mortality and morbidity.
Methods: We examined data collected through a prospective clinical study of HFMD conducted between 2000 and 2006
that included 3 distinct outbreaks of HEV71 to identify risk factors associated with neurological involvement in children
with HFMD.
Results: Total duration of fever ≥ 3 days, peak temperature ≥ 38.5°C and history of lethargy were identified as
independent risk factors for neurological involvement (evident by CSF pleocytosis) in the analysis of 725 children
admitted during the first phase of the study. When they were validated in the second phase of the study, two or more
(≥ 2) risk factors were present in 162 (65%) of 250 children with CSF pleocytosis compared with 56 (30%) of 186 children
with no CSF pleocytosis (OR 4.27, 95% CI2.79–6.56, p < 0.0001). The usefulness of the three risk factors in identifying
children with CSF pleocytosis on hospital admission during the second phase of the study was also tested. Peak
temperature ≥ 38.5°C and history of lethargy had the sensitivity, specificity, positive predictive value (PPV) and negative
predictive value (NPV) of 28%(48/174), 89%(125/140), 76%(48/63) and 50%(125/251), respectively in predicting CSF
pleocytosis in children that were seen within the first 2 days of febrile illness. For those presented on the 3rd or later day
of febrile illness, the sensitivity, specificity, PPV and NPV of ≥ 2 risk factors predictive of CSF pleocytosis were 75%(57/
76), 59%(27/46), 75%(57/76) and 59%(27/46), respectively.
Conclusion: Three readily elicited clinical risk factors were identified to help detect children at risk of neurological
involvement. These risk factors may serve as a guide to clinicians to decide the need for hospitalization and further
investigation, including cerebrospinal fluid examination, and close monitoring for disease progression in children with
HFMD
Effect of remote ischemic preConditioning on liver injury in patients undergoing liver resection: the ERIC-LIVER trial
OBJECTIVE: Novel hepatoprotective strategies are needed to improve clinical outcomes during liver surgery. There is mixed data on the role of remote ischemic preconditioning (RIPC). We investigated RIPC in partial hepatectomy for primary hepatocellular carcinoma (HCC). METHODS: This was a Phase II, single-center, sham-controlled, randomized controlled trial (RCT). The primary hypothesis was that RIPC would reduce acute liver injury following surgery indicated by serum alanine transferase (ALT) 24 h following hepatectomy in patients with primary HCC, compared to sham. Patients were randomized to receive either four cycles of 5 min/5 min arm cuff inflation/deflation immediately prior to surgery, or sham. Secondary endpoints included clinical, biochemical and pathological outcomes. Liver function measured by Indocyanine Green pulse densitometry was performed in a subset of patients. RESULTS: 24 and 26 patients were randomized to RIPC and control groups respectively. The groups were balanced for baseline characteristics, except the duration of operation was longer in the RIPC group. Median ALT at 24 h was similar between groups (196 IU/L IQR 113.5-419.5 versus 172.5 IU/L IQR 115-298 respectively, p = 0.61). Groups were similar in secondary endpoints. CONCLUSION: This RCT did not demonstrate beneficial effects with RIPC on serum ALT levels 24 h after partial hepatectomy
Automated segmentation of normal and diseased coronary arteries – The ASOCA challenge
Cardiovascular disease is a major cause of death worldwide. Computed Tomography Coronary Angiography (CTCA) is a non-invasive method used to evaluate coronary artery disease, as well as evaluating and reconstructing heart and coronary vessel structures. Reconstructed models have a wide array of for educational, training and research applications such as the study of diseased and non-diseased coronary anatomy, machine learning based disease risk prediction and in-silico and in-vitro testing of medical devices. However, coronary arteries are difficult to image due to their small size, location, and movement, causing poor resolution and artefacts. Segmentation of coronary arteries has traditionally focused on semi-automatic methods where a human expert guides the algorithm and corrects errors, which severely limits large-scale applications and integration within clinical systems. International challenges aiming to overcome this barrier have focussed on specific tasks such as centreline extraction, stenosis quantification, and segmentation of specific artery segments only. Here we present the results of the first challenge to develop fully automatic segmentation methods of full coronary artery trees and establish the first large standardized dataset of normal and diseased arteries. This forms a new automated segmentation benchmark allowing the automated processing of CTCAs directly relevant for large-scale and personalized clinical applications
- …