Core and Corona Modifications for the Design of Polymeric Micelle Drug-Delivery Systems

Polymeric nanoparticle micelles are formed from amphiphilic polymers with a hydrophobic core and a hydrophilic corona. Often comprised of a biodegradable, biocompatible polymer core and a poly(ethylene glycol) corona, these nanoparticle micelles encapsulate a hydrophobic drug and enable surface modification with targeting ligands. Strategies to enhance hydrophobic drug encapsulation are described as chemistries that facilitate covalent modification with antibodies using water-based click chemistry.     

Rapid Communication: Experimental Evidence that Juvenile Pelagic Jacks (Carangidae) Respond Behaviorally to DMSP

Dimethylsulfoniopropionate (DMSP) is produced by marine algae and released during foraging activity by zooplankton and fish. Pelagic fishes depend on patchily distributed foraging opportunities, and DMSP may be an important signaling molecule for these events. We have previously shown that the abundance of carangid jacks is positively associated with elevated DMSP levels over coral reefs in the Gulf of Mexico, suggesting that these fishes may use spatial and temporal variation in DMSP to locate foraging opportunities. Here, we extend this work by demonstrating that juveniles of two species of pelagic jack, crevalle jack, Caranx hippos, and bluefin trevally, C. melampygus, detect and respond to DMSP in a flow-through tank in the laboratory. Juveniles of these species showed elevated swimming activity in response to ecologically relevant concentrations of DMSP (10⁻⁹ M). These results provide further evidence that this chemical may serve as a chemosensory cue for carangid species.     

Response of a Generalist Herbivore <Emphasis Type="Italic">Trichoplusia ni</Emphasis> to Jasmonate-Mediated Induced Defense in Tomato

The up-regulation of plant defense-related toxins or metabolic enzyme binding proteins often leads to a negative effect on herbivorous insects. These negative effects can manifest themselves at three points: changes in food ingestion, post-ingestive-changes, and post-digestive changes. Many studies have related the decrease in herbivore growth and/or survival with expression of chemicals that interfere with post-digestive effects such as the anti-nutritive effects of protease inhibitors. Nevertheless, it is unclear whether such compounds impact herbivores via earlier ingestive processes. We addressed this question by using a jasmonate-deficient mutant (Def-1), a jasmonate-overexpressor mutant (Prosystemin or Prosys), and wild-type tomato in three trials with 5th instar Trichoplusia ni. Decreases in relative growth rate (RGR) confirmed that T. ni fed on the Prosys plants developed poorly compared to those feeding on Def-1 plants (larvae on wild-types were intermediate). Preingestive and postingestive processes contributed to this effect. Total food ingested and the consumptive index were 25% lower on Prosys plants compared to Def-1 plants. Post-ingestive processes, measured by approximate digestibility, were 62% greater on Prosy plants. Post-digestive efficiency measured by conversion of ingested and digested food (ECI and ECD) decreased on Prosys plants two-fold compared to Def-1 plants. This post-digestive interference correlated well with the 2-fold decrease in activity of digestive enzymes, serine proteases, in Prosys-fed T. ni compared to those on Def-1 plants. No difference in detoxifying enzyme activity was detected.     

High molecular weight copolymers of vinylferrocene and 3-phenyl[5]ferrocenophane-1,5-dimethylene with various N-substituted maleimides

Two series of ferrocene-containing polymers have been synthesized from various N-substituted maleimides with 3-phenyl[5]ferrocenophane-1,5-dimethylene (3A–C) or vinylferrocene (4A–C). These copolymers exhibit high molecular weights and 4A–C formed free standing films. Electrochemical studies with copolymers 3A–C and 4A–C in dimethylacetamide show chemical reversibility for all of the materials but only copolymers 4A–C show electrochemical reversibility. These copolymers were also electrochemically deposited from methylene chloride onto a platinum electrode to form chemically modified electrodes (CMEs). The CMEs show desorption of the ferrocene polymers in acetonitrile solutions but exhibited good stability in aqueous solution. The thermal stabilities of the copolymers 4A–C are typical for a ferrocene containing polymer with 10% weight loss occurring at ca. 385 °C. Copolymers 3A–C exhibit higher thermal stabilities with 10% weight loss at 438 °C. Differential scanning calorimetry measurements of the copolymers showed melt transitions just before the onset of thermal decomposition.     

赫尔辛基中央图书馆

正PAR建筑事务所参与了赫尔辛基中央图书馆设计竞赛,本案是他们的参赛方案。作为北欧国家芬兰的首都,赫尔辛基城市景观多样,梦幻般的波罗的海、点缀着尖顶建筑的广袤天际线、T(o|¨)(o|¨)l(o|¨)nlahti地区的都市化气息都为设计这样一栋垂直立体感十足的图书馆建筑提供了源源不断的灵感来源。     

Measurement of rotation of individual spherical particles in cohesive granulates

To explore dynamical processes in granular matter, we use a combination of 3D imaging and mechanical testing. We analyze structural changes using confocal microscopy while applying a compression load simultaneously. Fluorescently labeled polydisperse silica particles were hydrophobized with long alkyl chains and dispersed in an index-matching liquid. The particles show a weak attraction. Photobleaching the central plane of individual particles generates an optical anisotropy without changing particle interaction. In a series of 3D images, we follow trajectories and rotation of single particles. We focus on particle translation and rotation in dependency of the local volume fraction. During compression, restructuring happens predominantly in regions of low packing density. We show that rotation plays an important role and is hence a key parameter for explaining dynamical processes in granular systems.     

Metals in female scalp hair globally and its impact on perceived hair health

Globally, billions of individuals wash their hair in water, which acts as an exogenous metal source. Many studies which measure the metal levels found on human hair specifically aim to remove exogenous materials prior to analysis. Although this is needed when using hair analysis to probe the impact of the local environment on endogenous metal levels, it is not relevant for understanding exactly what is on hair as a result of contact with its daily environment. Understanding these levels are important, as the presence of redox active metals, such as copper and iron, can impact fibre health, either as a result of UV irradiation, or during the hair colouring process. A global hair sampling study of over 300 individuals from nine countries has been performed, and the combined endogenous and exogenous metals analysed. The levels measured vary widely, even within the narrow geography of each hair sampling location. The levels of calcium, magnesium, copper and iron were not correlated, and within each location, there are expected to be individuals with high metal levels. Levels increased from hair root to tip for calcium, magnesium and copper, attributed to hair contact with the environment showing the impact of exogenous metals in the overall levels on hair. Levels of redox metals were comparable between individuals who coloured or did not colour their hair, although water hardness ions were statistically significantly higher for hair colouring individuals. Individuals who perceived their hair health as poor had higher metal levels on their hair. Controlling metals on hair, either by preventing their binding during environmental contact, or through controlling their ability to cause hair damage, should lead to improved consumer perceived hair health.     

Emotion recognition in schizophrenia: Further investigation of generalized versus specific deficit models.

In this study, the authors examined the nature of emotion perception in schizophrenia. Two samples of people with schizophrenia, one receiving acute care for a recent exacerbation of symptoms and the other receiving extended care, were compared with a nonclinical control group on emotion perception and general perception measures. The nonclinical control group obtained the highest scores on all of the study measures, and the acutely ill group obtained the lowest scores. Furthermore, the acutely ill sample had a specific deficit in emotion perception that remained present after controlling for performance on the general perception tasks. Conversely, the deficits in emotion discrimination in the extended-care sample reflected generalized poor performance. Differences in performance on the emotion identification task between the 2 clinical groups were reduced when controlling for active symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)