1,020 research outputs found

    ingenierie contractuelle et performance de l'entreprise : perspective économique et dynamique de droit des contrats

    Get PDF
    Comment s'articulent les rationalités managériales et juridiques ? Les règles de droit ont longtemps été réduites par les entrepreneurs au rang de contraintes entravant les libertés de commerce et d'entreprendre. Pourtant, l'application des règles de droit influence fortement la gestion des risques et la performance juridique de l'entreprise. La question, en effet, ne se résoud pas dans l'analyse de la fraude et il est possible d'observer une convergence des règles de droit et du projet économiques de l'entreprise . Dans le même sens, le développement récent des analyses économiques du droit a posé les jalons d'un cadre théorique permettant d'envisager l'application du droit comme un outil de performance, dans lequel s'inscrit du reste une doctrine émergente que l'on pourrait qualifier d'utilitariste

    The erythrocytic schizogony of two synchronized strains of Plasmodium berghei, NK65 and ANKA, in normocytes and reticulocytes

    Get PDF
    By a modified Percoll-glucose centrifugation technique the rings and young trophozoites of two strains of Plasmodium berghei, NK65 and ANKA, were separated from the other erythrocytic stages and inoculated into mice. The subsequent infection was followed for ANKA in normal mice and for NK65 in normal mice and in mice with high-grade reticulocytosis induced by injections of phenylhydrazine. The duration of the erythrocytic schizogony of the NK65 strain was shown to be independent of the age of the host cell, and the hour of inoculation did not influence the cycle of the ANKA strain

    Tecnicas de laboratorio para la seleccion de sustancias antimalaricas

    Get PDF

    Oesophageal perforation: an unexpected complication during extraction of a pacing lead. A case report.

    Get PDF
    Background: Peri-procedural transoesophageal echocardiography (TOE) is important in monitoring and minimizing major complications during pacing lead extraction. It is a widely accepted precautionary measure, especially in extractions considered to be higher risk. Pacing lead extraction may be challenging, and it is associated with significant risk of major bleeding from vascular trauma. Case summary: We present a case of an 87-year-old woman who had an extraction of a ventricular pacing lead that had perforated to an extra-cardiac location, most likely to the left pleural space. Peri-procedural TOE was used as a precaution. The entire pacing lead was successfully extracted with gentle traction using standard equipment (mechanical technique). Extraction was followed by development of pneumomediastinum and a left pleural effusion, initially attributed to pulmonary injury from the pacing lead but which proved to be related to oesophageal injury from the TOE. Discussion: Transoesophageal echocardiography-related complications are uncommon but should be considered in cases of unexpected post-procedural deterioration. Clinical deterioration after a seemingly uneventful procedure should prompt a thorough case review. A systematic approach should be applied to identify the offending cause and enable corrective measures to be undertaken. This case report is an important reminder to all operators utilizing TOE for peri-procedural purposes that this precautionary measure itself also independently exposes the patient to additional risk

    Biological activities of nitidine, a potential anti-malarial lead compound

    Get PDF
    International audienceAbstract Background Nitidine is thought to be the main active ingredient in several traditional anti-malarial remedies used in different parts of the world. The widespread use of these therapies stresses the importance of studying this molecule in the context of malaria control. However, little is known about its potential as an anti-plasmodial drug, as well as its mechanism of action. Methods In this study, the anti-malarial potential of nitidine was evaluated in vitro on CQ-sensitive and -resistant strains. The nitidine's selectivity index compared with cancerous and non-cancerous cell lines was then determined. In vivo assays were then performed, using the four-day Peter's test methodology. To gain information about nitidine's possible mode of action, its moment of action on the parasite cell cycle was studied, and its localization inside the parasite was determined using confocal microscopy. The in vitro abilities of nitidine to bind haem and to inhibit β-haematin formation were also demonstrated. Results Nitidine showed similar in vitro activity in CQ-sensitive and resistant strains, and also a satisfying selectivity index (> 10) when compared with a non-cancerous cells line. Its in vivo activity was moderate; however, no sign of acute toxicity was observed during treatment. Nitidine's moment of action on the parasite cycle showed that it could not interfere with DNA replication; this was consistent with the observation that nitidine did not localize in the nucleus, but rather in the cytoplasm of the parasite. Nitidine was able to form a 1-1 complex with haem in vitro and also inhibited β-haematin formation with the same potency as chloroquine. Conclusion Nitidine can be considered a potential anti-malarial lead compound. Its ability to complex haem and inhibit β-haematin formation suggests a mechanism of action similar to that of chloroquine. The anti-malarial activity of nitidine could therefore be improved by structural modification of this molecule to increase its penetration of the digestive vacuole in the parasite, where haemoglobin metabolization takes place

    Mental Workload Alters Heart Rate Variability, Lowering Non-linear Dynamics

    Get PDF
    Mental workload is known to alter cardiovascular function leading to increased cardiovascular risk. Nevertheless, there is no clear autonomic nervous system unbalance to be quantified during mental stress. We aimed to characterize the mental workload impact on the cardiovascular function with a focus on heart rate variability (HRV) non-linear indexes. A 1-h computerized switching task (letter recognition) was performed by 24 subjects while monitoring their performance (accuracy, response time), electrocardiogram and blood pressure waveform (finger volume clamp method). The HRV was evaluated from the beat-to-beat RR intervals (RRI) in time-, frequency-, and informational- domains, before (Control) and during the task. The task induced a significant mental workload (visual analog scale of fatigue from 27 ± 26 to 50 ± 31 mm, p < 0.001, and NASA-TLX score of 56 ± 17). The heart rate, blood pressure and baroreflex function were unchanged, whereas most of the HRV parameters markedly decreased. The maximum decrease occurred during the first 15 min of the task (P1), before starting to return to the baseline values reached at the end of the task (P4). The RRI dimension correlation (D2) decrease was the most significant (P1 vs. Control: 1.42 ± 0.85 vs. 2.21 ± 0.8, p < 0.001) and only D2 lasted until the task ended (P4 vs. Control: 1.96 ± 0.9 vs. 2.21 ± 0.9, p < 0.05). D2 was identified as the most robust cardiovascular variable impacted by the mental workload as determined by posterior predictive simulations (p = 0.9). The Spearman correlation matrix highlighted that D2 could be a marker of the generated frustration (R = –0.61, p < 0.01) induced by a mental task, as well as the myocardial oxygen consumption changes assessed by the double product (R = –0.53, p < 0.05). In conclusion, we showed that mental workload sharply lowered the non-linear RRI dynamics, particularly the RRI correlation dimension
    corecore