Linear hydrogen adsorbate structures on graphite induced by self-assembled molecular monolayers

Combined scanning tunnelling microscopy measurements and density functional theory calculations reveal a method to induce linear structures of hydrogen adsorbates on graphite by covering the surface with a self-assembled molecular monolayer of cyanuric acid and exposing it to atomic hydrogen. The method can in principle be applied to obtain nanopatterned hydrogen structures on free standing graphene and graphene laid down on insulating substrates, hereby opening up for the possibility of substrate independent bandgap engineering of graphene.     

Conversion of the maltogenic {alpha}-amylase Novamyl into a CGTase

Novamyl is a thermostable five-domain maltogenic     

A method for cognitive 3D geological voxel modelling of AEM data

Airborne electromagnetic (AEM) data have proven successful for the purpose of near-surface geological mapping and are increasingly being collected worldwide. However, conversion of data from measured resistivity to lithology is not a straightforward task. Therefore, it is still challenging to make full use of these data. Many limitations must be considered before a successful geological interpretation can be performed and a reasonable 3D geological model constructed. In this paper, we propose a method for 3D geological modelling of AEM data in which the limitations are jointly considered together with a cognitive and knowledge-driven data interpretation. The modelling is performed iteratively by using voxel modelling techniques with tools developed for this exact purpose. Based on 3D resistivity grids, the tools allow the geologist to select voxel groups that define any desirable volumetric shape in the 3D model. Recent developments in octree modelling ensure exact modelling with a limited number of voxels.     

A comparison of filtered vs. unfiltered metal concentrations in treatment wetlands

Filtered vs. unfiltered metals analyses are compared from two demonstration wetlands built by ARCO in Butte, Montana. The Wetlands Demonstration Project 1 (WDP1) facility was an anaerobic, subsurface flow wetland, whereas the Colorado Tailings (CT) facility was a lime-added, aerobic system. At both sites, a significant fraction of each metal of concern (Cu, Cd, Zn, Fe, and Mn) existed in particulate form in some parts of the treatment system. The anaerobic WDP1 wetland removed dissolved metals to very low levels, but had mixed success in filtering out fine-grained sulfide precipitates of Cu, Cd and Zn. The CT wetland showed better capacity to remove particulate metals. Based on these two case studies, the importance of obtaining both filtered and unfiltered (total recoverable) samples at treatment wetlands is stressed.     

鱼肌肉蛋白质组学分级过程的重现性研究

在比较蛋白质组学中,分级过程经常被用于去除高丰度蛋白质,从而提高低丰度蛋白质的浓度至检出限以上。作者为了证实在二维凝胶电泳分离流程中增加额外的分级过程将会减小对金头鲷宰前应激响应时间依赖检测中所引入的噪声和批次间的偏差,采用多维标度对结果数据进行了多参数分析。结果表明生物响应比分级引入的误差高出几个数量级,而批次间误差不小于不同IEF/SDS-PAGE运行所引入的偏差。     

AFM study of glucagon fibrillation via oligomeric structures resulting in interwoven fibrils

Glucagon is a 29-residue amphiphatic hormone involved in the regulation of blood glucose levels in conjunction with insulin. In concentrated aqueous solutions, glucagon spontaneously aggregates to form amyloid fibrils, destroying its biological activity. In this study we utilize the atomic force microscope (AFM) to elucidate the fibrillation mechanism of glucagon at the nanoscale under acidic conditions (pH?2.0) by visualizing the nanostructures of fibrils formed at different stages of the incubation. Hollow disc-shaped oligomers form at an early stage in the process and subsequently rearrange to more solid oligomers. These oligomers co-exist with, and most likely act as precursors for, protofibrils, which subsequently associate to form at least three different classes of higher-order fibrils of different heights. A repeat unit of around 50?nm along the main fibril axis suggests a helical arrangement of interwoven protofibrils. The diversity of oligomeric and fibrillar arrangements formed at pH?2.0 complements previous spectroscopic analyses that revealed that fibrils formed under different conditions can differ substantially in stability and secondary structure.     

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.