87 research outputs found

    The effect of epidural anaesthesia on peripheral resistance and graft flow following femorodistal reconstruction

    Get PDF
    Objective:To determine the extent to which epidural anaesthesia influences peripheral resistance and graft blood flow following femorocrural reconstruction.Design:Prospective, controlled study measuring blood flow, arterial pressure and peripheral resistance in femorocrural bypass grafts for 20 min following onset of epidural anaesthesia with 15ml of 0.25% bupivacaine.Patients:Twenty patients undergoing femorocrural reconstruction for critical lower-limb ischaemia with in situ long saphenous vein, under general anaesthesia. Ten patients had epidural cannulae inserted preoperatively and injected with bupivacaine after completion of the graft.Results:Peripheral resistance fell in all 10 patients receiving epidural anaesthesia from a mean (range) of 1.07 PRU (0.32–2.2) to 0.49 PRU (0.19–0.72), compared to control values of 0.95 PRU (0.39–2.0) to 0.91 PRU (0.41–1.51; P < 0.01, Wilcoxon). There was a tendency for blood pressure to fall in the study patients (not significant) but graft blood flow still increased from 98 ml min−1 (41–221) to 160 ml min−1 (101–250), compared to flow in the control patients of 101 ml min−1 (45–176) at baseline to 104 ml min−1 (56–168; p < 0.01) at 20 min.Conclusions:Epidural anaesthesia significantly decreases peripheral resistance and increases graft blood flow in femorocrural grafts and would appear, therefore, to be of benefit for patients undergoing femorodistal reconstruction

    On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection

    Get PDF
    A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)

    Effect of maturation on carbazole distributions as revealed by the hydrous pyrolysis of an organic-sulphur-rich source rock (Ghareb Formation, Jordan)

    No full text
    Hydrous pyrolysis experiments were performed on the Ghareb Formation (Upper Cretaceous, Jordan), a carbonate- and organic-rich (TOC 19.6%) source rock, using a temperature range of 200 to 360°C (72 h). The original sediment contains only low amounts of carbazoles, (maximum 2.2 g/g bitumen for 1-methylcarbazole). With increasing thermal maturation, intense generation begins at temperatures only in excess of 300°C, reaching a maximum at 360°C. Likewise, during natural maturation, generation occurs at later stages of maturity (e.g. for Tithonian source rocks at >0.81% Rr and for Posidonia Shale at >0.88% Rr). Some isomeric changes during hydrous pyrolysis do not resemble those in nature whereas others do. The relative abundances of selected C1- and C2-alkylcarbazoles on ternary diagrams reveal differences, whereas the benzo[a]carbazole/benzo[a]carbazole+benzo[c]carbazole ratio is closely similar. The latter result supports the contention that maturation plays a key role in controlling carbazole distributions in source rocks. However, the results for alkylcarbazoles, especially the C2-carbazoles, are not easy to interpret

    Agreement between premortem and postmortem diagnoses in patients with acquired immunodeficiency syndrome observed at a brazilian teaching hospital

    No full text
    Acquired immunodeficiency syndrome (AIDS) is one of the main causes of death in adults worldwide. More commonly than in the general population, in patients with AIDS there is substantial disagreement between causes of death which are clinically suspected and those established by postmortem examination. The findings of 52 postmortem examinations were compared to the premortem (clinical) diagnoses, and there was 46% agreement between them. Fifty two percent of the patients had more than one postmortem diagnosis, and 48% had at least one AIDS-related disease not suspected clinically. Cytomegalovirus infection was the commonest (30.7%) autopsy finding, but not a single case had been suspected premortem. Bacterial infection, tuberculosis, and histoplasmosis were also common, sometimes not previously suspected, postmortem findings. This study shows that multiple infections occur simultaneously in AIDS patients, and that many among them are never suspected before the postmortem examination. These findings suggest that an aggressive investigation of infections and cancers should be done in patients with AIDS, particularly in those who do not respond to therapy of an already recognized condition<br>Concordância entre diagnósticos clínicos e de necrópsia em pacientes com síndrome da imunodeficiência adquirida observados em um hospital universitário brasileiro A síndrome da imunodeficiência adquirida (SIDA) é uma das principais causas de morte em adultos em todo mundo. Com maior freqüência do que ocorre na população geral, há em pacientes com SIDA uma substancial discordância entre as causas de morte clinicamente suspeitadas e as estabelecidas pelas autópsias. Revisamos os achados de 52 necrópsias de pacientes com SIDA e seus respectivos diagnósticos clínicos, e encontramos 46% de concordância entre eles. Cinquenta e dois por cento dos pacientes tiveram mais de um diagnóstico necroscopicamente definido e 48% tiveram pelo menos uma doença relacionada à SIDA, não suspeitada clinicamente. Infecção pelo citomegalovírus foi o achado necroscópico mais comum (30,7%) e em nenhum dos casos o diagnóstico foi suspeitado em vida. Infecção bacteriana, tuberculose, e histoplasmose foram também achados freqüentes de necrópsia, por vezes não suspeitados anteriormente. Este estudo demonstra que múltiplas infecções ocorrem simultaneamente em pacientes com SIDA, sendo que muitas delas sequer são suspeitadas clinicamente. Estes achados sugerem que investigação agressiva de infecções e neoplasias deva ser feita em pacientes com SIDA, particularmente naqueles que não respondem ao tratamento de uma patologia já diagnosticad

    Background languages, learner motivation and self-assessed progress in learning Zulu as an additional language in the UK

    No full text
    The paper reports results of a study of beginner-level learners of Zulu in higher education in the UK, focussing on learners’ linguistic background, their motivation and reasons for studying Zulu, and their self-assessed progress at the beginning of the second term of teaching. The study shows that participants typically studied Zulu as an additional or L3 language and often had prior knowledge of three or four background languages, including in many cases prior knowledge of an African language. They studied Zulu for personal, academic and professional reasons and their motivation was integrative as well as instrumental. Many expected to use Zulu professionally, in particular for work or study in South Africa. While learners’ motivation does not interact significantly with self-assessed progress, the study suggests that both a higher number of background languages, and knowledge of an African language structurally similar to Zulu might have positive effects on self-assessed progress
    • …
    corecore