The preparation of HEMA-MPC films for ocular drug delivery

There is a need to prolong drug residence time using a biocompatible formulation in the subconjunctival space after surgery to treat glaucoma. Drug releasing discs were prepared with 2-(hydroxyethyl)methacrylate (HEMA) and 2-methacryloyl-oxyethyl phosphorylcholine (MPC). The ratio of bound water (Wb) to free water (Wf) ratio increased from 1:0.3 to 1:6.8 with increasing MPC (0 to 50%, w/w). The optimal balance between water content, SR and mechanical strength were obtained with 10% MPC (w/w) hydrogels. Water-alcohol mixtures were examined to facilitate loading of poorly soluble drugs, and they showed greater hydrogel swelling than either water or alcohol alone. The SR was 1.2 ± 0.02 and 3.3 ± 0.1 for water and water:ethanol (1:1) respectively. HEMA-MPC (10%) discs were loaded with dexamethasone using either water:ethanol (1:1) or methanol alone. Drug release was examined in an outflow rig model that mimics the subconjunctival space in the eye. Dexamethasone loading increased from 0.3 to 1.9 mg/disc when the solvent was changed from water:ethanol (1:1) to methanol with the dexamethasone half-life (t½) increasing from 1.9 to 9.7 days respectively. These encouraging results indicate that HEMA-MPC hydrogels have the potential to sustain the residence time of a drug in the subconjunctival space of the eye

Plântulas de soja 'Tracajá' expostas ao ozônio sob condições controladas

The objective of this work was to assess initial growth, biomass production, gas exchange and antioxidative defenses of soybean 'Tracajá' seedlings, cultivated in the Amazonian region, exposed to ozone under controlled conditions. Seeds germinated in pots were placed in two chambers, one with filtered air (AF) and other with filtered air plus 30 ppb of ozone (AF + O 3). At 10 and 20 days after sowing, gas exchange, growth and biomass were measured; at 20 days after sowing, antioxidative defenses (ascorbic acid and superoxide dismutase) were analyzed. Net photosynthesis, stomatal conductance, transpiration rate, height, leaf area and biomass were 16, 27, 11, 22, 29 and 18% smaller, respectively, in AF + O3 at 10 days after sowing. At 20 days after sowing, besides this parameters, root length, stem diameter and root:shoot ratio were 10, 15 and 12% smaller, respectively, although ascorbic acid concentrations and superoxide dismutase activity increased. Soybean 'Tracajá' seedlings have low tolerance to concentration of 30 ppb of ozone

Beurteilung des immissionsbedingten Schaedigungsgrades von Laub- und Nadelbaeumen anhand biochemischer Kriterien sowie Erprobung der Schutzmoeglichkeiten durch MERNIEL-Behandlung Endbericht

Available from TIB Hannover: D.Dt.F. AC 1000(34,52) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Monitoring von Schaeden in Waldoekosystemen des bayerischen Alpenraumes

This regional multifactorial investigation addresses the dependence of vitality of Norway spruce and European beech (crown transparency, site index, root systems and nutritional status) on ecological factors and the presence of pathogens in mountain forests of the Bavarian Alps (Germany). Existing data on airborne deposition and ozone concentrations were supplemented by 2 elevational transects, in which wet bulk deposition was measured and ozone passive samplers were exposed during 2 vegetation periods. The distribution of crown transparency in spruce and beech as related to site conditions and its relationships with long-term stand growth, nutritional status and root morphology suggest that transparent crowns as observed in the Calcareous Alps are nothing new and unlikely to be caused by atmospheric pollution. Their distribution must be regarded as an old, long-lasting and natural pattern of tree vitality. (orig.)Es wurde die Abhaengigkeit der Vitalitaet von Fichten und Buchen (Kronentransparenz, Bestandesbonitaet, Wurzel- und Ernaehrungszustand) in den Bergwaeldern des Werdenfelser Landes (Oberbayern) von Standortsfaktoren und vom Befall durch pilzliche Pathogene mit einem regionalstatistischen, multifaktoriellen Ansatz untersucht. Vorhandene Daten zu Stoffeintrag und Ozonbelastung wurden durch eine zweijaehrige Beprobung des Freilandniederschlags und Ozon-Passivsammler-Messungen in zwei Hoehenprofilen ergaenzt. Die standortbezogene Verteilung der Kronentransparenz und ihre Beziehungen zum langfristigen Bestandeswachstum, zum Ernaehrungs- und Wurzelzustand legen nahe, dass es sich in den Kalkalpen nicht um neuartige, immissionsbedingte Waldschaeden, sondern um seit Alters her bestehende, natuerliche Vitalitaetsunterschiede handelt. (orig.)SIGLEAvailable from TIB Hannover: RN 7632(155) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Veraenderung der Konzentration praeformierter Abwehrtoxine gegenueber mikrobiellen Schaderregern in Koniferennadeln

TIB Hannover: FR 3263+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman