Hemostatic multilayer coatings

Spray layer-by-layer assembly is used to create hemostatic films containing thrombin and tannic acid. The spray assembly technique enables coating of porous and absorbent commercial gelatin sponges with these films. Coated sponges are able to promote instantaneous hemostasis in a porcine spleen bleeding model.     

Electrospun polystyrene fibers containing high temperature stable volatile fragrance/flavor facilitated by cyclodextrin inclusion complexes

In this study, we report on electrospinning of functional polystyrene (PS) fibers containing cyclodextrin-menthol inclusion complexes (CD-menthol-ICs). Our goal is to develop functional electrospun fibers containing fragrances/flavors with enhanced durability and stability assisted by cyclodextrin inclusion complexation. We have used menthol as a model fragrance/flavor material and CD-menthol-ICs were incorporated in electrospun PS fiber by using three types of CDs; α-CD, β-CD and γ-CD. Due to complexation of menthol with CDs, we observed that the stabilization of menthol was achieved up to 350 °C for all the PS/CD-menthol-IC webs whereas the PS fibers without the CD complex could not preserve volatile menthol molecules. In addition, γ-CD was more effective for the stabilization and release of menthol at a broad temperature range (100–350 °C) when compared to α-CD and β-CD. This study suggested that the electrospun fibers functionalized with CD-ICs are very effective for enhancing the temperature stability of volatile fragrances/flavors and therefore show potentials for the development of functional fibrous materials.     

Expert elicitation on ultrafine particles: likelihood of health effects and causal pathways

Background

Exposure to fine ambient particulate matter (PM) has consistently been associated with increased morbidity and mortality. The relationship between exposure to ultrafine particles (UFP) and health effects is less firmly established. If UFP cause health effects independently from coarser fractions, this could affect health impact assessment of air pollution, which would possibly lead to alternative policy options to be considered to reduce the disease burden of PM. Therefore, we organized an expert elicitation workshop to assess the evidence for a causal relationship between exposure to UFP and health endpoints.

Methods

An expert elicitation on the health effects of ambient ultrafine particle exposure was carried out, focusing on: 1) the likelihood of causal relationships with key health endpoints, and 2) the likelihood of potential causal pathways for cardiac events. Based on a systematic peer-nomination procedure, fourteen European experts (epidemiologists, toxicologists and clinicians) were selected, of whom twelve attended. They were provided with a briefing book containing key literature. After a group discussion, individual expert judgments in the form of ratings of the likelihood of causal relationships and pathways were obtained using a confidence scheme adapted from the one used by the Intergovernmental Panel on Climate Change.

Results

The likelihood of an independent causal relationship between increased short-term UFP exposure and increased all-cause mortality, hospital admissions for cardiovascular and respiratory diseases, aggravation of asthma symptoms and lung function decrements was rated medium to high by most experts. The likelihood for long-term UFP exposure to be causally related to all cause mortality, cardiovascular and respiratory morbidity and lung cancer was rated slightly lower, mostly medium. The experts rated the likelihood of each of the six identified possible causal pathways separately. Out of these six, the highest likelihood was rated for the pathway involving respiratory inflammation and subsequent thrombotic effects.

Conclusion

The overall medium to high likelihood rating of causality of health effects of UFP exposure and the high likelihood rating of at least one of the proposed causal mechanisms explaining associations between UFP and cardiac events, stresses the importance of considering UFP in future health impact assessments of (transport-related) air pollution, and the need for further research on UFP exposure and health effects.     

Discovery of Ligands for the Human Intestinal Di‐/Tripeptide Transporter (hPEPT1) Using a QSAR‐Assisted Virtual Screening Strategy

The discovery of novel ligands for the hPEPT1 transporter is reported. By exploiting a fast and rigorously validated QSAR model in combination with the distance in activity‐centered chemical space (DACCS) approach, a database of commercially available compounds (Sigma–Aldrich) was screened for virtual hits. Twelve compounds were then purchased and characterized in an apical [¹⁴C]Gly‐Sar uptake competition assay. Four compounds displayed affinity in the medium‐to‐high range. A simple benzophenone derivative displayed high affinity with a sub‐millimolar binding constant (K_i=0.24 mM ). The results of this study will serve as starting points for future projects, including the design and synthesis of compound libraries that seek to systematically explore the fundamental requirements for binding and transport by hPEPT1.     

Biodeterioration of synthetic materials – A brief review

Although synthetic polymers are part of our global waste problem because they are not sufficiently biologically degraded, microorganisms can severely impair the properties and functions of these materials. It seems as if consumers do not really acknowledge this cause of problems and there is only sparse systematic research about. Damaging mechanisms include (i) covering of surfaces (biofouling) which may be enhanced by leaching of biodegradable additives, (ii) depletion of such additives which can lead to loss of material properties, (iii) intrusion into materials by fungal hyphae, (iv) water uptake, and (v) discoloration. The common countermeasure is the addition of biocides or simply to tolerate the effects of biodeterioration and live on with them. It is suggested to encourage further systematic research, and to develop integrated strategies in order to avoid problems, e.g., based on nutrient and water limitation whenever possible.     

Pathway analysis for BioAmbients

Systems Biology aims for a holistic understanding of biological processes. In order to make this understanding operational and testable it can be recorded into formal process calculus models. This is a difficult task, however, because such formal models and their, often infinitely many, consequences are hard to enumerate and understand. In this paper we define a pathway analysis, based on static analysis techniques from programming languages, and show how it can be used to establish useful, finite, approximations to the set of causal consequences of models. The Pathway Analysis can be used to great advantage in all phases of the modelling approach – serving as the basis of debugging during model development, postdiction during model validation, and, finally, prediction during model guided drug design.     

Disconnect in concept learning by rhesus monkeys (Macaca mulatta): Judgment of relations and relations-between-relations.

The authors investigated the role that entropy measures, discriminative cues, and symbolic knowledge play for rhesus monkeys (Macaca mulatta) in the acquisition of the concepts of same and different for use in a computerized relational matching-to-sample task. After repeatedly failing to perceive relations between pairs of stimuli in a 2-choice discrimination paradigm, monkeys rapidly learned to discriminate between 8-element arrays. Subsequent tests with smaller arrays, however, suggested that, although important for the initial acquisition of the concept, entropy is not a variable on which monkeys are dependent. Not only do monkeys choose a corresponding relational pair in the presence of a cue, but they also choose the cue itself in the presence of the relational pair--in essence, labeling those relations. Subsequent failure in the judgment of relations-between-relations, however, suggests that perhaps a qualitatively different cognitive component exists that prevents monkeys from behaving analogically. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Function of gene 49 of bacteriophage T4 III. Isolation of Holliday structures from very fast-sedimenting DNA

Branched DNA molecules were identified in ClaI digests of cytosine containing very fast-sedimenting DNA (VFS-DNACYT) which was isolated from Escherichia coli infected with the multiple mutant 49-GT7 of phage T4. In about 10% of randomly picked ClaI fragments branches with three arms (Y-structures) as well as four arms (Holliday structures) were seen in the electron microscope. Branched structures were absent from ClaI digests after treatment with purified endonuclease VII (gp49) in vitro.