468 research outputs found
3D manufacturing tolerancing with probing of a local work coordinate system
International audienceThe safety and performance requirements for mechanisms are such that the necessary accuracy of part geometry is difficult to reach using classical manufacturing processes. This paper proposes a manufacturing tolerance stack-up method based on the analysis line method. This technique enables both the analysis and the synthesis of ISO manufacturing specifications through a new approach which relies on production specifications, adjustment specifications and their analysis to stack up the 3D resultant. The originality of the method resides in the 3D calculation for location requirements, which takes into account angular effects and probing operations on numerical-control machine-tools in order to define a local Work Coordinate System (WCS). For achieving tolerance analysis, deviations are modelled using Small-Displacement Torsor. This tolerance analysis method enables one to determine explicit three-dimensional linear relations between manufacturing tolerances and functional requirements. These relations can be used as constraints for tolerance optimization
Secondary metabolites of Bagassa guianensis Aubl. wood: A study of the chemotaxonomy of the Moraceae family
International audienceIn order to explain the durability of the Moraceae plant family, phytochemistry of Bagassa guianensis was performed. Ethyl acetate extract was obtained from the heartwood and 18 secondary metabolites were isolated, including 6 moracins [6-O-methyl-moracin M, 6-O-methyl-moracin N and moracin Z; previously identified: moracin M, moracin N and moracin P], 8 stilbenoids [presently identified: ( )-epialboctalol and arachidin 4; previously identified: alboctalol, trans-resveratrol, arachidin 2, trans-oxyresveratrol and artogomezianol], 3 previously identified flavonoids, steppogenin, katuranin and dihydromorin, bsitosterol and resorcinol. Previous studies suggest that stilbenoids are responsible for the natural durability of wood. Our study has determined that B. guianensis is closely related to Morus sp. in phylogeny and should be included in the Moreae sensu stricto tribe of the Moraceae family
High-pressure intrapleural chemotherapy: feasibility in the pig model.
International audienceABSTRACT: BACKGROUND: The usual treatments for pleural malignancies are mostly palliative. In contrast, peritoneal malignancies are often treated with a curative intent by cytoreductive surgery and intraperitoneal chemotherapy. As pressure has been shown to increase antitumor efficacy, we applied the concept of high-pressure intracavitary chemotherapy to the pleural space in a swine model. METHODS: Cisplatin and gemcitabine were selected because of their antineoplasic efficacy in vitro in a wide spectrum of cancer cell lines. The pleural cavity of 21 pigs was filled with saline solution; haemodynamic and respiratory parameters were monitored. The pressure was increased to 15-25 cm H2O. This treatment was associated with pneumonectomy in 6 pigs. Five pigs were treated with chemotherapy under pressure. RESULTS: The combination of gemcitabine (100 mg/l) and cisplatin (30 mg/l) was highly cytotoxic in vitro. The maximum tolerated pressure was 20 cm H20, due to haemodynamic failure. Pneumonectomy was not tolerated, either before or after pleural infusion. Five pigs survived intrapleural chemotherapy associating gemcitabine and cisplatin with 20 cm H2O pressure for 60 min. CONCLUSIONS: High-pressure intrapleural chemotherapy is feasible in pigs. Further experiments will establish the pharmacokinetics and determine whether the benefit already shown in the peritoneum is also obtained in the pleura
Impacts of climate change on high priority fruit fly species in Australia
Tephritid fruit flies are among the most destructive horticultural pests posing risks to Australiaâs multi-billion-dollar horticulture industry. Currently, there are 11 pest fruit fly species of economic concern in Australia. Of these, nine are native to this continent (Bactrocera aquilonis, B. bryoniae, B. halfordiae, B. jarvisi, B. kraussi, B. musae, B. neohumeralis, B. tryoni and Zeugodacus cucumis), while B. frauenfeldi and Ceratitis capitata are introduced. To varying degrees these species are costly to Australiaâs horticulture through in-farm management, monitoring to demonstrate pest freedom, quarantine and trade restrictions, and crop losses. Here, we used a common species distribution model, Maxent, to assess climate suitability for these 11 species under baseline (1960â1990) and future climate scenarios for Australia. Projections indicate that the Wet Tropics is likely to be vulnerable to all 11 species until at least 2070, with the east coast of Australia also likely to remain vulnerable to multiple species. While the Cape York Peninsula and Northern Territory are projected to have suitable climate for numerous species, extrapolation to novel climates in these areas decreases confidence in model projections. The climate suitability of major horticulture areas currently in eastern Queensland, southern-central New South Wales and southern Victoria to these pests may increase as climate changes. By highlighting areas at risk of pest range expansion in the future our study may guide Australiaâs horticulture industry in developing effective monitoring and management strategies
Bulletin agrométéorologique - Situation au 30 juin 2010
A la fin du mois de juin, les conditions mĂ©tĂ©orologiques peuvent ĂȘtre qualifiĂ©es de globalement bonnes sur la plus grande partie du territoire belge. De bons rendements sont annoncĂ©s sans toutefois atteindre les rendements exceptionnels comme ceux du blĂ© de lâan dernier. Les analyses spatiales dĂ©rivĂ©es de la tĂ©lĂ©dĂ©tection confirment cette tendance favorable tout en
indiquant une hĂ©tĂ©rogĂ©nĂ©itĂ© importante dans certaines rĂ©gions du pays qui peut ĂȘtre mise sur le compte de prĂ©cipitations orageuses localisĂ©es. Les conditions climatiques des prochaines semaines seront dĂ©terminantes pour conserver tous les bons potentiels de rendement des cultures et Ă©viter que la situation ne se dĂ©grade pour les zones Ă plus faible potentiel
Bulletin agrométéorologique - Situation au 21 juin 2009
Depuis le dernier bulletin publiĂ© fin avril, les conditions mĂ©tĂ©orologiques ont Ă©tĂ© fort proches des normales avec toutefois quelques Ă©pisodes orageux qui ont pu causer ça et lĂ des dĂ©gĂąts aux cultures. La vĂ©gĂ©tation semble avoir ralenti davantage sa croissance que ce qui sâobserve dâhabitude depuis dix ans, cela en particulier dans le Nord et le Nord-Ouest du pays, probablement en raison des conditions pluvieuses rencontrĂ©es dans ces zones. Cependant les prĂ©visions de rendements Ă lâĂ©chelle nationale ne semblent pas ĂȘtre affectĂ©es. A lâexception du maĂŻs, les rendements sâannoncent meilleurs que la moyenne des quatre derniĂšres annĂ©es
Bulletin agrométéorologique - Situation au 30 avril 2009
Alors que lâon pouvait craindre les consĂ©quences de lâhiver froid que nous avons connu cette annĂ©e, il apparaĂźt, au niveau de nos indicateurs mĂ©tĂ©orologiques et de nos indicateurs spatiaux dĂ©rivĂ©s de la tĂ©lĂ©dĂ©tection, que les grandes cultures ont dans lâensemble bien passĂ© lâhiver et elles ont largement rattrapĂ© le retard accumulĂ© au cours des mois dâhiver et du tout dĂ©but de printemps. Ceci se vĂ©rifie Ă©galement sur le terrain oĂč les stades phĂ©nologiques sont trĂšs
proches de la situation normale. Aucune prĂ©vision de rendement nâest faite Ă ce stade
Pharmacokinetic modelling and development of Bayesian estimators for therapeutic drug monitoring of mycophenolate mofetil in reduced-intensity haematopoietic stem cell transplantation.
International audienceBACKGROUND: Mycophenolate mofetil, a prodrug of mycophenolic acid (MPA), is used during non-myeloablative and reduced-intensity conditioning haematopoetic stem cell transplantation (HCT) to improve engraftment and reduce graft-versus-host disease (GVHD). However, information about MPA pharmacokinetics is sparse in this context and its use is still empirical. OBJECTIVES: To perform a pilot pharmacokinetic study and to develop maximum a posteriori Bayesian estimators (MAP-BEs) for the estimation of MPA exposure in HCT. PATIENTS AND METHODS: Fourteen patients administered oral mycophenolate mofetil 15 g/kg three times daily were included. Two consecutive 8-hour pharmacokinetic profiles were performed on the same day, 3 days before and 4 days after the HCT. One 8-hour pharmacokinetic profile was performed on day 27 after transplantation. For these 8-hour pharmacokinetic profiles, blood samples were collected predose and 20, 40, 60, 90 minutes and 2, 4, 6 and 8 hours post-dose. Using the iterative two-stage (ITS) method, two different one-compartment open pharmacokinetic models with first-order elimination were developed to describe the data: one with two gamma laws and one with three gamma laws to describe the absorption phase. For each pharmacokinetic profile, the Akaike information criterion (AIC) was calculated to evaluate model fitting. On the basis of the population pharmacokinetic parameters, MAP-BEs were developed for the estimation of MPA pharmacokinetics and area under the plasma concentration-time curve (AUC) from 0 to 8 hours at the different studied periods using a limited-sampling strategy. These MAP-BEs were then validated using a data-splitting method. RESULTS: The ITS approach allowed the development of MAP-BEs based either on 'double-gamma' or 'triple-gamma' models, the combination of which allowed correct estimation of MPA pharmacokinetics and AUC on the basis of a 20 minute-90 minute-240 minute sampling schedule. The mean bias of the Bayesian versus reference (trapezoidal) AUCs was 20%. AIC was systematically calculated for the choice of the most appropriate model fitting the data. CONCLUSION: Pharmacokinetic models and MAP-BEs for mycophenolate mofetil when administered to HCT patients have been developed. In the studied population, they allowed the estimation of MPA exposure based on three blood samples, which could be helpful in conducting clinical trials for the optimization of MPA in reduced-intensity HCT. However, prior studies will be needed to validate them in larger populations
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