Comparison of cardiac outputs during major surgery using the Deltex CardioQ oesophageal Doppler monitor and the Novametrix-Respironics NICO: A prospective observational study

AbstractIntroductionRecent studies have emphasised the importance of optimisation of intraoperative fluid administration in patients undergoing major abdominal surgery. A variety of non-invasive devices capable of measuring cardiac output are available for this purpose. Most studies have used the Deltex CardioQ Oesophageal Doppler monitor (DCQ ODM, Deltex, Chichester, Sussex, UK). A relatively new, totally non-invasive cardiac monitor is now available, the Novametrix-Respironics NICO machine (Novametrix-Respironics, USA).AimsThis pilot study compared cardiac output values obtained during major abdominal surgery from the simultaneous use of these two devices.ObjectivesTo assess the reproducibility and consistency of the readings obtained to determine whether these monitors can be used interchangeably for optimising perioperative fluid administration.Methods182 simultaneous paired cardiac output readings were obtained from 12 consecutive patients undergoing prolonged major abdominal surgery. These were analysed using correlation coefficients, scattergrams and Bland Altman plots.ResultsAlthough the r value obtained for correlation was 0.3639 (p<0.0001), the Bland Altman plot showed significant differences of between −4.1 and +5.1lpm between the readings means with a bias of 0.5lpm for the NICO over the DCQ ODM. In addition, a sequential plot of simultaneous cardiac outputs showed great disparity between the two devices in some patients.ConclusionCaution should be exercised before using these monitors to optimise intraoperative fluid administration as potentially very large volumes of fluid may be administered to achieve surrogate endpoints. These devices need to be compared side by side with a gold standard method of determining cardiac output before they can be used interchangeably for optimising intraoperative fluid administration in abdominal surgery

The impact of second language learning on semantic and nonsemantic first language reading

The relationship between orthography (spelling) and phonology (speech sounds) varies across alphabetic languages. Consequently, learning to read a second alphabetic language, that uses the same letters as the first, increases the phonological associations that can be linked to the same orthographic units. In subjects with English as their first language, previous functional imaging studies have reported increased left ventral prefrontal activation for reading words with spellings that are inconsistent with their orthographic neighbors (e.g., PINT) compared with words that are consistent with their orthographic neighbors (e.g., SHIP). Here, using functional magnetic resonance imaging (fMRI) in 17 Italian--English and 13 English--Italian bilinguals, we demonstrate that left ventral prefrontal activation for first language reading increases with second language vocabulary knowledge. This suggests that learning a second alphabetic language changes the way that words are read in the first alphabetic language. Specifically, first language reading is more reliant on both lexical/semantic and nonlexical processing when new orthographic to phonological mappings are introduced by second language learning. Our observations were in a context that required participants to switch between languages. They motivate future fMRI studies to test whether first language reading is also altered in contexts when the second language is not in use

A biological-inspired support frame for an artificial cornea

Bilateral corneal blindness represents a quarter of the total blind, world-wide. The artificial cornea in assorted forms, was developed to replace opaque non-functional corneas and to return sight in otherwise hopeless cases that were not amenable to corneal grafts; believed to be 2% of corneal blind. Despite technological advances in materials design and tissue engineering no artificial cornea has provided absolute, long-term success. Formidable problems exist, due to a combination of unpredictable wound healing and unmanageable pathology. To have a solid guarantee of reliable success an artificial cornea must possess three attributes: an optical window to replace the opaque cornea; a strong, long term union to surrounding ocular tissue; and the ability to induce desired host responses. A unique artificial cornea possesses all three functional attributes- the Osteo-odonto-keratoprosthesis (OOKP). The OOKP has a high success rate and can survive for up to twenty years, but it is complicated both in structure and in surgical procedure; it is expensive and not universally available. The aim of this project was to develop a synthetic substitute for the OOKP, based upon key features of the tooth and bone structure. In doing so, surgical complexity and biological complications would be reduced. Analysis of the biological effectiveness of the OOKP showed that the structure of bone was the most crucial component for implant retention. An experimental semi-rigid hydroxyapatite framework was fabricated with a complex bone-like architecture, which could be fused to the optical window. The first method for making such a framework, was pressing and sintering of hydroxyapatite powders; however, it was not possible to fabricate a void architecture with the correct sizes and uniformity of pores. Ceramers were synthesised using alternative pore forming methods, providing for improved mechanical properties and stronger attachment to the plastic optical window. Naturally occurring skeletal structures closely match the structural features of all forms of natural bone. Synthetic casts were fabricated using the replamineform process, of desirable natural artifacts, such as coral and sponges. The final method of construction by-passed ceramic fabrication in favour of pre-formed coral derivatives and focused on methods for polymer infiltration, adhesion and fabrication. Prototypes were constructed and evaluated; a fully penetrative synthetic OOKP analogue was fabricated according to the dimensions of the OOKP. Fabrication of the cornea shaped OOKP synthetic analogue was also attempted

The role of the left head of caudate in suppressing irrelevant words

Suppressing irrelevant words is essential to successful speech production and is expected to involve general control mechanisms that reduce interference from task-unrelated processing. To investigate the neural mechanisms that suppress visual word interference, we used fMRI and a Stroop task, using a block design with an event-related analysis. Participants indicated with a finger press whether a visual stimulus was colored pink or blue. The stimulus was either the written word "BLUE," the written word "PINK," or a string of four Xs, with word interference introduced when the meaning of the word and its color were "incongruent" (e.g., BLUE in pink hue) relative to congruent (e.g., BLUE in blue) or neutral (e.g., XXXX in pink). The participants also made color decisions in the presence of spatial interference rather than word interference (i.e., the Simon task). By blocking incongruent, congruent, and neutral trials, we identified activation related to the mechanisms that suppress interference as that which was greater at the end relative to the start of incongruency. This highlighted the role of the left head of caudate in the control of word interference but not spatial interference. The response in the left head of caudate contrasted to bilateral inferior frontal activation that was greater at the start than at the end of incongruency, and to the dorsal anterior cingulate gyrus which responded to a change in the motor response. Our study therefore provides novel insights into the role of the left head of caudate in the mechanisms that suppress word interference

A neighbourhood level mortality classification of England and Wales, 2006-2009

The paper provides an overview of a neighbourhood level classification of mortality for England and Wales (2006–2009). Standardised mortality ratios for 63 causes of death were calculated for middle super output areas (weighted by prevalence). A k-means partitional method was used to classify the data. An eight cluster solution was found to best segment mortality patterns. Clusters mostly differentiated in terms of prevalence, however the importance of neurodegenerative diseases and causes related to unhealthy behaviours were important. The results describe a neighbourhood classification that can be an important tool to help inform policy development, resource allocation and targeting of services

Proton magnetic resonance and polarographic studies of some aminated naphthoquinones

Variable temperature n.m.r. and polarographic measurements have been performed on a series of cyclic secondary aminonaphthoquinones. The results indicate that ring strain is not the only factor which would explain the order of effective electron donation by the various amines to the quinone nucleus

Improving reservoir conformance using gelled polymer systems

The general objectives are to (1) to identify and develop gelled polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) to determine the performance of these systems in bulk and in porous media, and (3) to develop methods to predict the capability of these systems to recover oil from petroleum reservoirs. This work focuses on three types of gel systems - an aqueous polysaccharide (KUSPI) system that gels as a function of pH, the chromium-based system where polyacrylamide and xanthan are crosslinked by CR(III) and an organic crosslinked system. Development of the KUSPI system and evaluation and identification of a suitable organic crosslinked system will be done. The laboratory research is directed at the fundamental understanding of the physics and chemistry of the gelation process in bulk form and in porous media. This knowledge will be used to develop conceptual and mathematical models of the gelation process. Mathematical models will then be extended to predict the performance of gelled polymer treatments in oil reservoirs. Accomplishments for this period are presented for the following tasks: development and selection of gelled polymer systems, physical and chemical characterization of gel systems; and mathematical modeling of gel systems

A pyrene-appended spiropyran for selective photo-switchable binding of Zn(II): UV-visible and fluorescence spectroscopy studies of binding and non-covalent attachment to graphene, graphene oxide and carbon nanotubes

PublishedArticleSynthesis of photo-switchable, Zn2+ sensitive hybrid materials was achieved by facile non-covalent functionalization of graphene, graphene oxide and carbon nanotubes with a pyrene-appended spiropyran. Solution phase binding studies, using UV–visible and fluorescence spectroscopy, indicated that the pyrene-spiropyran dyad was highly selective for Zn2+ over a range of potentially competitive cations and that binding occurred with 1:1 stoichiometry and a binding constant of K=1.4×104 mol−1 dm3 at 295 K. Zn2+ binding was promoted by UV irradiation or in darkness and reversed upon irradiation with visible light.Engineering & Physical Sciences Research Council (EPSRC

Vapor pressures and vapor compositions in equilibrium with hypostoichiometric plutonium dioxide at high temperatures

Vapor pressures and vapor compositions in equilibrium with a hypostoichiometric plutonium dioxide condensed phase have been calculated for the temperature range 1500 less than or equal to T less than or equal to 4000 K. Thermodynamic functions for the condensed phase and for each of the gaseous species were combined with an oxygen-potential model to obtain the partial pressures of O/sub 2/, O, Pu, PuO, and PuO/sub 2/. New thermodynamic functions for the solid oxide were calculated from available information and from new estimates of the heat capacity of the liquid. Thermodynamic functions for the vapor species were calculated previously. A suitable oxygen-potential model has been used previously for the solid hypostoichiometric plutonium dioxide; this model has been extended into the liquid region using several alternative methods. The effects of these alternatives on the calculated oxygen pressures have been examined in detail

Increased Oil Recovery From Mature Oil Fields Using Gelled Polymer Treatments

Gelled polymer treatments are applied to oil reservoirs to increase oil production and to reduce water production by altering the fluid movement within the reservoir. This report describes the results of a three-year research program aimed at reducing barriers to the widespread use of gelled polymer treatments by (1) developing methods to predict gel behavior during placement in matrix rock and fractures, (2) determining the persistence of permeability reduction after gel placement, and (3) developing methods to design production well treatments to control water production. The work focused on the gel system composed of polyacrylamide and chromium acetate. The molar mass of the polymer was about six million. Chromium(III) acetate reacted and formed crosslinks between polymer molecules. The crosslinked polymer molecules, or pre-gel aggregates, combine and grow to eventually form a 3-dimensional gel. A fundamental study to characterize the formation and growth of pre-gel aggregates was conducted. Two methods, flow field-flow fractionation (FFFF) and multi-angle laser light scattering (MALLS) were used. Studies using FFFF were inconclusive. Data taken using MALLS showed that at the gel time the average molar mass of gel aggregates increased by a factor of about three while the average size increase was approximately 50%. Increased acetate concentration in the gelant increases the gel time. The in situ performance of an added-acetate system was investigated to determine the applicability for in-depth treatments. Increased acetate concentrations delayed the development of increased flow resistance during gelant injection in short sandpacks. The development of increased flow resistance (in situ gelation) was extended from 2 to 34 days by increasing the acetate-to-chromium ratio from 38 to 153. In situ gelation occurred at a time that was approximately 22% of the bulk gelation time. When carbonate rocks are treated with gel, chromium retention in the rock may limit in-depth treatment. Chromium retention due to precipitation was investigated by flowing chromium acetate solutions through carbonate rock. Chromium precipitated faster in the rocks than in beaker experiments at similar conditions. A mathematical model previously developed fit the precipitation data reasonably well. The stability of gels when subjected to stress was investigated by experiments with gels placed in tubes and in laboratory-scale fractures. Rupture pressures for gels placed in small diameter tubes were correlated with the ratio of tube length to tube ID. In fractures, fluid leakoff from the fracture to adjacent matrix rock affected gel formation and gel stability in a positive way. Disproportionate permeability reduction (DPR) was studied in unconsolidated sandpacks and in Berea sandstone cores. A conceptual model was developed to explain the presence of DPR. The effect of a pressure gradient, imposed by injection of oil or brine, on the permeability of gel-treated cores was investigated. DPR increased significantly as the pressure gradient was decreased. The magnitude of the pressure gradient had a much larger effect on water permeability than on oil permeability