Distribution of Gold Nanoparticles in the Anterior Chamber of the Eye after Intracameral Injection for Glaucoma Therapy.

In glaucoma therapy, nanoparticles (NPs) are a favorable tool for delivering drugs to the outflow tissues of the anterior chamber of the eye where disease development and progression take place. In this context, a prerequisite is an efficient enrichment of NPs in the trabecular meshwork with minimal accumulation in off-target tissues such as the cornea, lens, iris and ciliary body. We evaluated the optimal size for targeting the trabecular meshwork by using gold NPs of 5, 60, 80 and 120 nm with a bare surface (AuNPs) or coated with hyaluronic acid (HA-AuNPs). NPs were compared regarding their colloidal stability, distribution in the anterior chamber of the eye ex vivo and cellular uptake in vitro. HA-AuNPs demonstrated an exceptional colloidal stability. Even after application into porcine eyes ex vivo, the HA coating prevented an aggregation of NPs inside the trabecular meshwork. NPs with a diameter of 120 nm exhibited the highest volume-based accumulation in the trabecular meshwork. Off-target tissues in the anterior chamber demonstrated an exceptionally low gold content. Our findings are particularly important for NPs with encapsulated anti-glaucoma drugs because a higher particle volume would be accompanied by a higher drug payload.

Characteristics of predrinking and associated risks: a survey in a sample of German high school students.

OBJECTIVES: Finding predictors for predrinking and placing the new phenomenon of predrinking on a greater database. Predrinking is defined as alcohol consumption, alone or with friends, at home or at public places, before going out in the evening to a party or in bars or discotheques. METHODS: Data were collected from a representative sample of 757 ninth- and tenth-grade students from 31 high schools located in a south German rural region and a city. RESULTS: Predrinkers, especially those who show this behaviour frequently, were notably more likely to engage in hazardous drinking, and experienced significantly more frequent involvements in fights and alcohol-induced blackouts. They also stated more often that they had the intention of getting drunk when consuming alcohol. CONCLUSIONS: Predrinking proves to be a high-risk behaviour, particularly when it occurs at a high frequency. This behaviour has to be seen as part of a new youth culture, which does not seem to be limited to a certain subgroup-with all of the associated risks.

Preferences and illusions in quantified spatial relational reasoning.

The following presents the results of an investigation of strategies and preferences in human reasoning about quantified spatial relational assertions. An empirical study revealed a clear preference effect for specific models: The initially constructed model depends on the number of mental model operations. The participants' strategies can be classified as follows: (1) Models with grouped elements are preferred; (2) Models are constructed according to a parsimonious representation strategy. Systematic reasoning errors and illusions can be identified with logical connectors (AND: 86 % valid initial models; XOR: 47 %; Wilcoxon z = 4.6; p < .001). Error rates were smallest when using two universal quantifiers (All-All), they increase significantly when using one (Some-All; All-Some) and again using none (Some-Some) (Page's L = 436; z = 3.40 p < .001). Although the different assertions allowed for multiple situations, the difficulty can be traced back to specific quantifiers and logical connectors.