109 research outputs found
The effect of incubation temperature on the specificity of the BANA (N-benzoyl-DL-arginine-naphthylamide) test
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75429/1/j.1399-302X.1993.tb00544.x.pd
Kitozanski umetci za periodontitis: Utjecaj koliÄine lijeka, plastifikatora i umreĆŸavanja na oslobaÄanje metronidazola in vitro
Chitosan based metronidazole (MZ) inserts were fabricated by the casting method and characterized with respect to mass and thickness uniformity, metronidazole loading and in vitro metronidazole release kinetics. The fabricated inserts exhibited satisfactory physical characteristics. The mass of inserts was in the range of 5.63 ± 0.42 to 6.04 ± 0.89 mg. The thickness ranged from 0.46 ± 0.06 to 0.49 ± 0.08 mm. Metronidazole loading was in the range of 0.98 ± 0.09 to 1.07 ± 0.07 mg except for batch CM3 with MZ loading of 2.01 ± 0.08 mg. The inserts exhibited an initial burst release at the end of 24 h, irrespective of the drug to polymer ratio, plasticizer content or cross-linking. However, further drug release was sustained over the next 6 days. Cross-linking with 10% (m/m) of glutaraldehyde inhibited the burst release by ~30% and increased the mean dissolution time (MDT) from 0.67 to 8.59 days. The decrease in drug release was a result of reduced permeability of chitosan due to cross-linking.Umetci metronidazola na bazi kitozana napravljeni su kasting metodom. ProuÄavana je ujednaÄenost mase i debljine, koliÄina ljekovite tvari i kinetika oslobaÄanja metronidazola in vitro. FiziÄke karakteristike umetaka bile su zadovoljavajuÄe: masa je bila u rasponu 5,63 ± 0,42 â 6,04 ± 0,89 mg, debljina od 0.46 ± 0.06 â 0.49 ± 0.08 mm with, koliÄina metronidazola od 0,98 ± 0,09 â 1,07 ± 0,07 mg. Nakon 24 h iz svih umetaka, neovisno o omjeru ljekovite tvari i polimera, koliÄini plastifikatora ili umreĆŸavanju, dio metronidazola se naglo oslobodio. MeÄutim, daljnje oslobaÄanje je bilo polagano tijekom 6 dana. UmreĆŸavanje s 10% (m/m) otopinom glutaraldehida sprijeÄilo je naglo oslobaÄanje za ~30% i poveÄalo je srednje vrijeme oslobaÄanja (MDT) s 0,67 na 8,59 dana. Smanjenje u oslobaÄanju ljekovite tvari posljedica je smanjenja permeabilnosti umreĆŸenog kitozana
Scanning electron microscope study of 48-hour plaque on different bridge pontics designs.
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EfficacitĂ© dâinsecticides contre Scaphoideus titanus en vignobles biologiques et effets secondaires
La flavescence dorĂ©e de la vigne et la lutte obligatoire contre son vecteur Scaphoideus titanus posent dâimportants problĂšmes dans les vignobles conduits en culture biologique. Afin de dĂ©velopper une stratĂ©gie de lutte basĂ©e sur des insecticides compatibles avec la viticulture biologique, des essais en plein champ ont Ă©tĂ© conduits au Tessin en 2006-2007. Le Parexan N (pyrĂ©thrine + huile de sĂ©same) sâest avĂ©rĂ© le seul produit biologique efficace Ă plus de 90% contre les formes immatures de S. titanus, par contre il nâa eu aucun effet contre les adultes. Lâapplication rĂ©pĂ©tĂ©e de Parexan N sâest montrĂ©e toxique pour les typhlodromes de lâespĂšce Amblyseius andersoni. MalgrĂ© cette toxicitĂ©, la seule stratĂ©gie de lutte efficace et recommandĂ©e dans les vignobles biologique consiste en trois applications de Parexan N Ă un intervalle de dix jours dĂšs lâapparition des premiers individus du 3e stade larvaire
The CropSyst model to simulate the N balance of rice for alternative management
CropSyst is a mechanistic model developed for simulating the growth and development of potentially all herbaceous crops under potential and water/nitrogen (N)-limited conditions. Although the model has been widely used for many crops under different pedo-climatic and management conditions, studies on the simulation of water and N balance for flooded rice are lacking. We evaluated the CropSyst model for simulating the N balance of north-Italian rice fields for scatter-seeded rice grown under continuously flooded conditions. In order to calibrate and validate the model for the processes involved with soil N transformation, data collected in field experiments carried out in northern Italy between 2002 and 2004 were used. The results show the robustness of the model in reproducing the course of the measured soil mineral nitrogen content: the Modeling Efficiencies which describe the agreement between measured and simulated trends, are in most cases positive and the model error fell almost always within the experimental error on the measurements (P = 0.95). Moreover, the model showed the same level of reliability while simulating the nitrogen balances under different levels of nitrogen fertilization, thus depicting it as suitable for comparing N fertilization scenarios. This first attempt at using a model for simulating the nitrogen balance under flooded conditions encourages further studies because of the need of effective tools for optimizing the nitrogen management of flooded rice systems, considered significant sources of groundwater pollution and greenhouse gases in many European rice districts
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