3,319 research outputs found

    Protocol for electrophysiological monitoring of carotid endarterectomies.

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    Near zero stroke rates can be achieved in carotid endarterectomy (CEA) surgery with selective shunting and electrophysiological neuromonitoring. though false negative rates as high as 40% have been reported. We sought to determine if improved training for interpretation of the monitoring signals can advance the efficacy of selective shunting with electrophysiological monitoring across multiple centers, and determine if other factors could contribute to the differences in reports. Processed and raw beta band (12.5-30 Hz) electroencephalogram (EEG) and median and tibial nerve somatosensory evoked potentials (SSEP) were monitored in 668 CEA cases at six surgical centers. A decrease in amplitude of 50% or more in any EEG or SSEP channel was the criteria for shunting or initiating a neuroprotective protocol. A reduction of 50% or greater in the beta band of the EEG or amplitude of the SSEP was observed in 150 cases. No patient showed signs of a cerebral infarct after surgery. Selective shunting based on EEG and SSEP monitoring can reduce CEA intraoperative stroke rate to a near zero level if trained personnel adopted standardized protocols. We also found that the rapid administration of a protective stroke protocol by attending anesthesiologists was an important aspect of this success rate

    The Effect of Penetration Depth on Thermal Contrast of NDT by Thermography

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    Nondestructive evaluation by Thermography (TNDE) is generally classified into two categories, the passive approach and the active approach. The passive approach is usually performed by measuring the natural temperature difference between the ambient and the material or structure to be tested. The active approach, on the other hand, requires the application of an external energy source to stimulate the material for inspection. A laser, a heater, a hot air blower, a high power thermal pulse, mechanical, or electromagnetic energy may provide the energy sources. For the external heating method to inspect materials for defects and imperfection at ambient temperature, a very short burst of heat can be introduced to one of the surfaces or slow heating of the side opposite to the side being observed. Due to the interruption of the heat flow through the defects, the thermal images will reveal the defective area by contrasting against the surrounding good materials. This technique is called transient Thermography, pulse video Thermography, or thermal wave imaging. As an empirical rule, the radius of the smallest defect should be at least one to two times larger than its depth under the surface. Thermography is being used to inspect void, debond, impact damage, and porosity in composite materials. It has been shown that most of the defects and imperfection can be detected. However, the current method of inspection using thermographic technique is more of an art than a practical scientific and engineering approach. The success rate of determining the defect location and defect type is largely depend on the experience of the person who operates thermography system and performs the inspection. The operator has to try different type of heat source, different duration of its application time, as well as experimenting with the thermal image acquisition time and interval during the inspection process. Further-more, the complexity of the lay-up and structure of composites makes it more difficult to determine the optimal operating condition for revealing the defects. In order to develop an optimal thermography inspection procedure, we must understand the thermal behavior inside the material subjected to transient heat in order to interpret the thermal images correctly. Fabrication of finite element models of characteristic defects in composite materials subjected to transient heat will enable the development of appropriate procedure for thermography inspection. Design of phantom defects could be modeled and behavior characterized prior to physically building these test parts. Since production of phantom test parts can be very time consuming and laborious, it is important to design good representative defects

    Perceptions of health risk among parents of overweight children: a cross-sectional study within a cohort.

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    OBJECTIVE: To identify the socio-demographic and behavioural characteristics associated with perceptions of weight-related health risk among the parents of overweight children. METHODS: Baseline data from a cohort of parents of children aged 4-11 years in five areas in England in 2010-2011 were analysed; the sample was restricted to parents of overweight children (body mass index ≥ 91(st) centile of UK 1990 reference; n=579). Associations between respondent characteristics and parental perception of health risk associated with their child's weight were examined using logistic regression analyses. RESULTS: Most parents (79%) did not perceive their child's weight to be a health risk. Perception of a health risk was associated with recognition of the child's overweight status (OR 10.59, 95% CI 5.51 to 20.34), having an obese child (OR 4.21, 95% CI 2.28 to 7.77), and having an older child (OR 2.67, 95% CI 1.32 to 5.41). However, 41% of parents who considered their child to be overweight did not perceive a health risk. CONCLUSIONS: Parents that recognise their child's overweight status, and the parents of obese and older children, are more likely to perceive a risk. However, many parents that acknowledge their child is overweight do not perceive a related health risk

    Surgical education and training during the COVID-19 pandemic: Strategies and solutions for Pakistan

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    The coronovirus disease-2019 pandemic has severely impacted surgical education and training in Pakistan and worldwide, causing problems, such as risk of infection, limited hands-on training, examination delays, and trainee redeployment to non-surgical specialties. The current review was planned to describe innovative strategies adopted by surgical training programmes worldwide in order to suggest comprehensive recommendations at the level of the College of Physicians and Surgeons Pakistan and individual institutions to counter the challenges presented by the pandemic in Pakistan. The innovative use of technology, including open-access online educational portals, virtual educational activities and simulation-based learning, can help reform education delivery during the pandemic. Hospitals\u27 implementation of shift schedules for rotations helps continue training while minimising risks. Moreover, examination boards and residency programmes must appropriately tailor their eligibility criteria and assessment processes to the current situation. Lastly, it is vital to safeguard trainees\u27 mental wellness during the pandemic and after by ensuring readily available professional psychological support when needed

    Placental expression of angiopoietin-1, angiopoietin-2 and tie-2 during placental development in an ovine model of placental insufficiency-fetal growth restriction.

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    Fetal growth restriction (FGR) is associated with increased perinatal morbidity and mortality, and often results from functional placental insufficiency. Placentation requires extensive vasculogenesis and subsequent angiogenesis, in both maternal and fetal tissues. Angiopoietin-1 (Ang-1) and Angiopoietin-2 (Ang-2) are angiogenic growth factors expressed in the placenta, and compete for binding to a common receptor, Tunica interna endothelial cell kinase-2 (Tie-2). Our objective was to examine Ang-1, Ang-2 and Tie-2 expression in ovine placental tissue obtained from normal and FGR pregnancies throughout gestation. Fetal cotyledon and maternal caruncle tissue concentrations of Ang-1, Ang-2 and Tie-2 mRNA were assessed by real-time reverse transcriptase-polymerase chain reaction and protein concentrations were assessed by Western immunoblot analysis, at 55, 90 and 135 d gestational age (dGA). Concentrations of Ang-1, Ang-2 and Tie-2 mRNA in FGR fetal cotyledons were increased at 55 dGA, and Tie-2 mRNA concentrations were decreased in FGR fetal cotyledons and maternal caruncles at 135 dGA. Immunoblot analysis demonstrated increased concentrations of Ang-2 in the fetal cotyledon at 55 dGA, and lower concentrations at 135 dGA. In contrast, concentrations of Tie-2 were increased at 90 dGA, but tended to decrease at 135 dGA in FGR maternal caruncles. The changes observed during early- to mid-gestation may result in increased branching angiogenesis, but may also set the stage for increased nonbranching angiogenesis during late gestation, altered placental architecture and placental insufficiency that result in FGR

    A Natural Plasmid Uniquely Encodes Two Biosynthetic Pathways Creating a Potent Anti-MRSA Antibiotic

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    Background Understanding how complex antibiotics are synthesised by their producer bacteria is essential for creation of new families of bioactive compounds. Thiomarinols, produced by marine bacteria belonging to the genus Pseudoalteromonas, are hybrids of two independently active species: the pseudomonic acid mixture, mupirocin, which is used clinically against MRSA, and the pyrrothine core of holomycin. Methodology/Principal Findings High throughput DNA sequencing of the complete genome of the producer bacterium revealed a novel 97 kb plasmid, pTML1, consisting almost entirely of two distinct gene clusters. Targeted gene knockouts confirmed the role of these clusters in biosynthesis of the two separate components, pseudomonic acid and the pyrrothine, and identified a putative amide synthetase that joins them together. Feeding mupirocin to a mutant unable to make the endogenous pseudomonic acid created a novel hybrid with the pyrrothine via “mutasynthesis” that allows inhibition of mupirocin-resistant isoleucyl-tRNA synthetase, the mupirocin target. A mutant defective in pyrrothine biosynthesis was also able to incorporate alternative amine substrates. Conclusions/Significance Plasmid pTML1 provides a paradigm for combining independent antibiotic biosynthetic pathways or using mutasynthesis to develop a new family of hybrid derivatives that may extend the effective use of mupirocin against MRSA

    Predictors of health-related behaviour change in parents of overweight children in England.

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    OBJECTIVE: Providing parents with information about their child's overweight status (feedback) could prompt them to make lifestyle changes for their children. We assessed whether parents of overweight children intend to or change behaviours following feedback, and examined predictors of these transitions. METHODS: We analysed data from a cohort of parents of children aged 4-5 and 10-11 years participating in the National Child Measurement Programme in five areas of England, 2010-2011. Parents of overweight children (body mass index ≥91st centile) with data at one or six months after feedback were included (n=285). The outcomes of interest were intention to change health-related behaviours and positive behaviour change at follow-up. Associations between respondent characteristics and outcomes were assessed using logistic regression analysis. RESULTS: After feedback, 72.1% of parents reported an intention to change; 54.7% reported positive behaviour change. Intention was associated with recognition of child overweight status (OR 11.20, 95% CI 4.49, 27.93). Parents of older and non-white children were more likely to report behaviour changes than parents of younger or white children. Intention did not predict behaviour change. CONCLUSIONS: Parental recognition of child overweight predicts behavioural intentions. However, intentions do not necessarily translate into behaviours; interventions that aim to change intentions may have limited benefits

    Can the relationship between ethnicity and obesity-related behaviours among school-aged children be explained by deprivation? A cross-sectional study.

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    OBJECTIVES: It is unclear whether cultural differences or material disadvantage explain the ethnic patterning of obesogenic behaviours. The aim of this study was to examine ethnicity as a predictor of obesity-related behaviours among children in England, and to assess whether the effects of ethnicity could be explained by deprivation. SETTING: Five primary care trusts in England, 2010-2011. PARTICIPANTS: Parents of white, black and South Asian children aged 4-5 and 10-11 years participating in the National Child Measurement Programme (n=2773). PRIMARY OUTCOME MEASURES: Parent-reported measures of child behaviour: low level of physical activity, excessive screen time, unhealthy dietary behaviours and obesogenic lifestyle (combination of all three obesity-related behaviours). Associations between these behaviours and ethnicity were assessed using logistic regression analyses. RESULTS: South Asian ethnic groups made up 22% of the sample, black ethnic groups made up 8%. Compared with white children, higher proportions of Asian and black children were overweight or obese (21-27% vs16% of white children), lived in the most deprived areas (24-47% vs 14%) and reported obesity-related behaviours (38% with obesogenic lifestyle vs 16%). After adjusting for deprivation and other sociodemographic characteristics, black and Asian children were three times more likely to have an obesogenic lifestyle than white children (OR 3.0, 95% CI 2.1 to 4.2 for Asian children; OR 3.4, 95% CI 2.7 to 4.3 for black children). CONCLUSIONS: Children from Asian and black ethnic groups are more likely to have obesogenic lifestyles than their white peers. These differences are not explained by deprivation. Culturally specific lifestyle interventions may be required to reduce obesity-related health inequalities
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