5,188 research outputs found
Noncontacting ultrasonic system for concurrent defect detection in solidified weld metal
In-process ultrasonic sensing of welding allows detection of weld defects in real time. A noncontacting ultrasonic system is being developed to operate in a production environment. The principal components are a pulsed laser for ultrasound generation, an electromagnetic acoustic transducer (EMAT) for ultrasound reception, and a PC-based data acquisition system which determine the quality of the weld on a pass-by-pass basis. The laser/EMAT system interrogates the area in the weld volume where defects are most likely to occur [5]. This area of interest is identified by computer calculations on a pass-by-pass basis using weld planning information provided by the off-line programmer. The absence of a signal above the threshold level in the computer-calculated time interval indicates a disruption of the sound path by a defect. The ultrasonic sensor system then provides an input signal to the weld controller about the defect condition
Sepsis: precision-based medicine for pregnancy and the puerperium
Sepsis contributes significantly to global morbidity and mortality, particularly in vulnerable populations. Pregnant and recently pregnant women are particularly prone to rapid progression to sepsis and septic shock, with 11% of maternal deaths worldwide being attributed to sepsis. The impact on the neonate is considerable, with 1 million neonatal deaths annually attributed to maternal infection or sepsis. Pregnancy specific physiological and immunological adaptations are likely to contribute to a greater impact of infection, but current approaches to the management of sepsis are based on those developed for the non-pregnant population. Pregnancy-specific strategies are required to optimise recognition and management of these patients. We review current knowledge of the physiology and immunology of pregnancy and propose areas of research, which may advance the development of pregnancy-specific diagnostic and therapeutic approaches to optimise the care of pregnant women and their babies
Healthcare, frugal innovation, and professional voluntarism : a cost-benefit analysis
This book investigates what international placements of healthcare employees in low resource settings add to the UK workforce and the efficacy of its national health system. The authors present empirical data collected from a volunteer deployment project in Uganda focused on reducing maternal and new-born mortality and discuss the learning and experiential outcomes for UK health care professionals acting as long term volunteers in low resource settings. They also develop a model for structured placement that offers optimal learning and experiential outcomes and minimizes risk, while shedding new light on the role that international placements play as part of continuing professional development both in the UK and in other sending countries
Association of Cognitive Performance with Time at Altitude, Sleep Quality, and Acute Mountain Sickness Symptoms
Objective It is well documented that cognitive performance may be altered with ascent to altitude, but the association of various cognitive performance tests with symptoms of acute mountain sickness (AMS) is not well understood. Our objective was to assess and compare cognitive performance during a high-altitude expedition using several tests and to report the association of each test with AMS, headache, and quality of sleep. Methods During an expedition to Mount Everest, 3 cognitive tests (Stroop, Trail Making, and the real-time cognitive assessment tool, an in-house developed motor accuracy test) were used along with a questionnaire to assess health and AMS. Eight team members were assessed pre-expedition, postexpedition, and at several time points during the expedition. Results There were no significant differences (P >.05) found among scores taken at 3 time points at base camp and the postexpedition scores for all 3 tests. Changes in the Stroop test scores were significantly associated with the odds of AMS (P <.05). The logistic regression results show that the percent change from baseline for Stroop score (Ī² = ā5.637; P = .032) and Stroop attempts (Ī² = ā5.269; P = .049) are significantly associated with the odds of meeting the criteria for AMS. Conclusions No significant changes were found in overall cognitive performance at altitude, but a significant relationship was found between symptoms of AMS and performance in certain cognitive tests. This research shows the need for more investigation of objective physiologic assessments to associate with self-perceived metrics of AMS to gauge effect on cognitive performance
High power TiO2 and high capacity Sn-doped TiO2 nanomaterial anodes for lithium-ion batteries
A range of phase-pure anatase TiO2 (ā¼5 nm) and Sn-doped TiO2 nanoparticles with the formula Ti1-xSnxO2 (where x = 0, 0.06, 0.11 and 0.15) were synthesized using a continuous hydrothermal flow synthesis (CHFS) reactor. Charge/discharge cycling tests were carried out in two different potential ranges of 3 to 1 V and also a wider range of 3 to 0.05 V vs Li/Li+. In the narrower potential range, the undoped TiO2 nanoparticles display superior electrochemical performance to all the Sn-doped titania crystallites. In the wider potential range, the Sn-doped samples perform better than undoped TiO2. The sample with composition Ti0.85Sn0.15O2, shows a capacity of ca. 350 mAh gā1 at an applied constant current of 100 mA gā1 and a capacity of 192.3 mAh gā1 at a current rate of 1500 mA gā1. After 500 charge/discharge cycles (at a high constant current rate of 382 mA gā1), the same nanomaterial anode retains a relatively high specific capacity of 240 mAh gā1. The performance of these nanomaterials is notable, particularly as they are processed into electrodes, directly from the CHFS process (after drying) without any post-synthesis heat-treatment, and they are made without any conductive surface coating
Maternal sepsis update: current management and controversies
ā¢Sepsis is a leading cause of maternal morbidity and mortality, globally and in the UK. ā¢In pregnancy and the puerperium, women may be more susceptible to rapid deterioration of illness following an infection. ā¢Sepsis has a complex pathophysiology and the immunological and cardiovascular adaptations of normal pregnancy may have an adverse impact on the maternal response to infection. Furthermore, physiological changes of pregnancy, which mimic those of sepsis, often delay optimal management. ā¢āBedsideā identification of pathogens and their antibiotic resistance patterns may help to improve clinical outcomes. ā¢Recent updates in sepsis management, areas of controversy and the importance of translational research and clinical trials for pregnancy and the puerperium are discussed
A living systematic review and meta-analysis characterising treatment regimes, clinical outcomes and complications associated with extracorporeal life support (ELS) for critical COVID-19 in women in pregnancy and the puerperium compared to non-pregnant women of reproductive age and comparing materno-fetal outcomes to pregnant women without COVID-19
Human labour is associated with altered regulatory T cell function and maternal immune activation
During human pregnancy, regulatory T cell (Treg) function is enhanced and immune activation is repressed allowing the growth and development of the fetoāplacental unit. Here, we have investigated whether human labour is associated with a reversal of the pregnancyāinduced changes in the maternal immune system. We tested the hypothesis that human labour is associated with a decline in Treg function, specifically their ability to modulate Tollālike receptor (TLR)āinduced immune responses. We studied the changes in cell number, activation status and functional behaviour of peripheral blood, myometrial (myoMC) and cord blood mononuclear cells (CBMC) with the onset of labour. We found that Treg function declines and that Treg cellular targets change with labour onset. The changes in Treg function were associated with increased activation of myoMC, assessed by their expression of major histocompatibility complex (MHC) class II molecules and CBMC inflammatory cells. The innate immune system showed increased activation, as shown by altered monocyte and neutrophil cell phenotypes, possibly to be ready to respond to microbial invasion after birth or to contribute to tissue remodelling. Our results highlight changes in the function of the adaptive and innate immune systems that may have important roles in the onset of human labour
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Robust rf control of accelerators
The problem of controlling the variations in the rf power systems can be effectively cast as an application of modern control theory. Two components of this theory are obtaining a model and a feedback structure. The model inaccuracies influence the choice of a particular controller structure. One can design wither a variable, adaptive controller or a fixed, robust controller to achieve the desired objective. The adaptive control scheme usually results in very complex hardware; and therefore, shall not be pursued. In contrast, the robust control method leads to simplified hardware. However, robust control requires a more accurate mathematical model of the physical process than is required by adaptive control. Our research at the Los Alamos National Laboratory (LANL) and the University of New Mexico has led to the development and implementation of a new rf power feedback system. In this paper, we report on our research progress. In section one, the robust control problem for the rf power system and the philosophy adopted for the beginning phase of our research is presented. In section two, results of our proof-of-principle experiments are presented. In section three, we describe the actual controller configuration that is used in LANL FEL physics experiments. The novelty of our approach is that the control hardware is implemented directly in rf without demodulating, compensating, and then remodulating
Cardiogenic shock in pregnancy
Cardiac disease complicates 1%ā4% of pregnancies globally, with a predominance in low and middle-income countries (LMICs). Increasing maternal age, rates of obesity, cardiovascular comorbidities, pre-eclampsia and gestational diabetes all contribute to acquired cardiovascular disease in pregnancy. Additionally, improved survival in congenital heart disease (CHD) has led to increasing numbers of women with CHD undergoing pregnancy. Implementation of individualised care plans formulated through pre-conception counselling and based on national and international guidance have contributed to improved clinical outcomes. However, there remains a significant proportion of women of reproductive age with no apparent comorbidities or risk factors that develop heart disease during pregnancy, with no indication for pre-conception counselling. The most extreme manifestation of cardiac disease is cardiogenic shock (CS), where the primary cardiac pathology results in inadequate cardiac output and hypoperfusion, and is associated with significant mortality and morbidity. Key to management is early recognition, intervention to treat any potentially reversible underlying pathology and supportive measures, up to and including mechanical circulatory support (MCS). In this narrative review we discuss recent developments in the classification of CS, and how these may be adapted to improve outcomes of pregnant women with, or at risk of developing, this potentially lethal condition
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