77 research outputs found
Study of the Mg-Nd alloy obtained by electrolysis in molten oxifluoride media
Mg-Nd alloys have been produced by electrolysis of the molten mixture LiF-NdF3-MgF2 using Nd2(CO3)3 and MgF2 as raw materials. An electrolysis cell was designed having the anode made of super dense graphite and the cathode made of molybdenum metal. The quasi-binary system (NdF3-LiF)eutectic-MgF2 was investigated and the liquidus line was determined using thermo-differential analysis. The solubility of Nd2(CO3)3 in the LiF-NdF3-MgF2 system was investigated by the carbothermal technique
Assessment of the environmental status in Hellenic coastal waters (Eastern Mediterranean): from the Water Framework Directive to the Marine Strategy Water Framework Directive.
A  methodology is presented to assess the environmental status sensu the Marine Strategy Water Framework Directive (MSFD) based on data obtained from the monitoring of water quality in the Hellenic coastal waters within the Water Framework Directive (WFD).  An adapted decision tree used for integrating the results of the WFD in the Basque country was applied. Modifications lie to the evaluation of the physicochemical status based on a eutrophication index developed for Eastern Mediterranean waters. Results on hydromorphological, physicochemical and biological elements are presented. The chemical status was evaluated based on measurements of heavy metals in water. The evaluation of the biological quality was based on the use of metrics developed for phytoplankton biomass, benthic macroinvertebrates and macroalgae updated to accommodate MSFD needs. Results on the integrative status of the water bodies were validated by correlating classification results with a pressure index and environmental indicators in water column and sediment. Following this decision tree the majority of stations expected to be at risk of achieving the good status were found in moderate status. Benthos was found to be the element with the closest agreement with the integrated final status having an increased weighting in the decision tree. The quality of benthos and in some limited cases the eutrophication index determined largely the final status. The highest disagreement with the integrative classification was produced by macroalgae. All indicators used correlated with water and sediment parameters but benthos correlated better with sediment factors while phytoplankton and eutrophication index with water column parameters
Concurrent analysis of choice and control in childbirth?
Background: this paper reports original research on choice and control in childbirth. Eight women were interviewed as part of a wider investigation into locus of control in women with pre-labour rupture of membranes at term (PROM) [1].Methods: the following study uses concurrent analysis to sample and analyse narrative aspects of relevant literature along with these interviews in order to synthesise a generalisable analysis of the pertinent issues. The original PROM study had found that women experienced a higher degree of control in hospital, a finding that appeared at odds with contemporary notions of choice. However, this paper contextualises this finding by presenting narratives that lucidly subscribe to the dominant discourse of hospital as the safest place to give birth, under the premise of assuring a live healthy baby irrespective of their management type.Results: this complex narrative is composed of the following themes: 'perceiving risk', 'being prepared', 'reflecting on experience', maintaining control' and relinquishing control'. These themes are constructed within and around the medical, foetocentric, risk averse cultural context. Primary data are presented throughout to show the origins and interconnected nature of these themes.Conclusions: within this context it is clear that there is a highly valued role for competent health professionals that respect, understand and are capable of facilitating genuine choice for women
Spectral analysis of heart rate variability in the sepsis syndrome.
Sympathetic and parasympathetic activity was evaluated on 39 occasions in 17 patients with the sepsis syndrome, by measurement of the variation in resting heart rate using frequency spectrum analysis. Heart rate was recorded by electrocardiography and respiratory rate by impedance plethysmography. The sepsis syndrome was established on the basis of established clinical and physiological criteria. Subjects were studied, whenever possible, during the period of sepsis and during recovery. Spectral density of the beat-to-beat heart rate was measured within the low frequency band 0.04 to 0.10 Hz (low frequency power, LFP) modulated by sympathetic and parasympathetic activity, and within a 0.12 Hz band width at the respiratory frequency mode (respiratory frequency power, RFP) modulated by parasympathetic activity. Results were expressed as the total variability (total area beneath the power spectrum), as the spectral components normalized to the total power (LFPn, RFPn) or as the ratio of LFP/RFP. During the sepsis syndrome, total heart rate variability and the sympathetically mediated component, LFPn were significantly lower than during the following recovery phase (ANOVA, p < 0.0001, p < 0.01 respectively). Both APACHE II (Acute Physiological and Chronic Health Evaluation) and TISS (Therapeutic Intervention Scoring System) scores showed an inverse correlation with total heart rate variability, logLFP, LFPn and the LFP/RFP ratio (p < 0.002 to 0.0001). Sympathetically mediated heart rate variability was significantly lower during the sepsis syndrome and was inversely proportional to disease severity
Autonomic control of the heart and peripheral vessels in human septic shock.
OBJECTIVE: Circulating endotoxin impairs the sympathetic regulation of the cardiovascular system in animals. We studied the changes in the autonomic control of the heart and circulation during septic shock in humans. DESIGN: 12 patients (age 43.0 +/- 6, 17-83 years) were investigated during septic shock (mean duration: 3.5 +/- 0.5 days) and during recovery, fluctuations in R-R interval, invasive arterial pressure (AP) and peripheral arteriolar circulation (PC, photoplethysmography) were evaluated by spectral analysis as a validated noninvasive measure of sympathovagal tone. Apache II score was adopted as the disease severity index. Low frequency components (0.03-0.15 Hz) of the frequency spectra were expressed as relative to the overall variability (LFnu) for each cardiovascular variable. RESULTS: LFnu were low or absent during shock but, in the 10 patients who recovered, increased by the time of discharge (post-shock). R-R LFnu increased from 17 +/- 6 to 47 +/- 9 (p < 0.03), AP LFnu from 6 +/- 3 to 35 +/- 4 (p < 0.02) and PC LFnu from 18 +/- 3 to 66 +/- 4 (p < 0.001). Apache II fell from 23.1 +/- 1, at admission, to 14.8 +/- 1.8 at discharge (p < 0.005). Two patients died showing no LFnu increase. CONCLUSION: Reduced LF components of the variability of cardiovascular signals are characteristic of septic shock, confirming the presence of abnormal autonomic control. Restored sympathetic (LF) modulation seems to be associated with a favourable prognosis
- âŠ