Swiss Industrial Biocatalysis Consortium (SIBC)

Taking up the common challenges in biocatalysis, a group of industrialists decided to react with a bottom-up solution, and created the Swiss Industrial Biocatalysis Consortium (SIBC). The Swiss Industrial Biocatalysis Consortium is a pre-competitive working group to better implement and utilize existing know-how and resources in biocatalysis, and to influence and shape the economic and educational political environment. Recent examples of activities are outlined.     

Photosensitizers neutral red (type I) and rose bengal (type II) cause light-dependent toxicity in Chlamydomonas reinhardtii and induce the Gpxh gene via increased singlet oxygen formation

The connection between the mode of toxic action and the genetic response caused by the type I photosensitizer and photosynthesis inhibitor neutral red (NR) and the type II photosensitizer rose bengal (RB) was investigated in the green alga Chlamydomonas reinhardtii. For both photosensitizers, a light intensity-dependent increase in toxicity and expression of the glutathione peroxidase homologous gene (Gpxh) was found. The toxicity of RB was reduced by the singlet oxygen (1O2) quenchers 1,4-diazabicyclo[2.2.2]octane and L-histidine, and the RB-induced Gpxh expression was stimulated in deuterium oxide-supplemented growth medium. These observations clearly indicate the involvement of 1O2 in both toxicity and the genetic response caused by RB. NR up-regulated the expression of typical oxidative and general stress response genes, probably by a type I mechanism, and also strongly induced the Gpxh expression. The stimulating effect of deuterium oxide in the growth medium suggested the involvement of 1O2 also in the NR-induced response. Indeed, an increased 1O2 formation was detected with EPR-spin trapping in NR-treated spinach thylakoids. However, none of the 102 quenchers could reduce the light-dependent toxicity of NR in C. reinhardtii, indicating that NR has a different mode of toxic action than RB.     

Properties of Aqueous, Plastic Izer-Containing Ethyl Cellulose Dispersions and Prepared Films in Respect to the Production of oral Extended Release Formulations

Plasticized aqueous ethyl cellulose (EC) dispersions (Aquacoat^R ECD-30) are incompatible with concentrated electrolytes but stable with nonelectrolytes. The minimum film formation temperature (MFT) decreases with increasing plasticizer content, from 81°C to about 30°C with 20% dibutyl sebacate (DBS) in the resulting film. The plasticiser has to penetrate completely into the EC particles before film formation to obtain optimal plastification, the lowest film formation temperature and high permeability of the resulting film. This takes more than 5 hours with 20% DBS. Films prepared from plasticized dispersion with short standing times show craters of former plasticizer droplets. With increasing plasticizer content the sticking point of the films decreases. The plasticizer induce a high water absorption of the films: more than 30% with 23-26% DBS or diethyl phthalate (DEP). DBS is hardly released from the films within 5 hours, in contrast to DEP. Thus, the absorbed water is completely swelling water in case of DBS and partially also substitution water in case of DEP. The films squeeze out cetylalcohol (CA) and also sodium lauryl sulfate (NaLS) during storage, this may change the permeability of the films. EC contains a small amount of carboxylic groups which explains the pH dependent release of drugs from pellets coated with aqueous EC dispersions.     

工具磨削发展趋势

位于瑞士Etziken的Ewag公司是国际知名和领先的精密工具磨床开发与生产企业。在这一领域，Ewag以其有竞争力的研发工作创建了创新的磨削理念，对工具磨削技术的重大影响而著称。公司一直与汽车、航天、医疗、电子和手表制造业的用户紧密合作，不断积累在用户所用刀具开发方面的经验。当今的发展趋势集中在三个方面：     

Improvement of Aglycone π-Stacking Yields Nanomolar to Sub-nanomolar FimH Antagonists

Antimicrobial resistance has become a serious concern for the treatment of urinary tract infections. In this context, an anti-adhesive approach targeting FimH, a bacterial lectin enabling the attachment of E. coli to host cells, has attracted considerable interest. FimH can adopt a low/medium-affinity state in the absence and a high-affinity state in the presence of shear forces. Until recently, mostly the high-affinity state has been investigated, despite the fact that a therapeutic antagonist should bind predominantly to the low-affinity state. In this communication, we demonstrate that fluorination of biphenyl α-d -mannosides leads to compounds with perfect π–π stacking interactions with the tyrosine gate of FimH, yielding low nanomolar to sub-nanomolar K_D values for the low- and high-affinity states, respectively. The face-to-face alignment of the perfluorinated biphenyl group of FimH ligands and Tyr48 was confirmed by crystal structures as well as ¹H,¹⁵N-HSQC NMR analysis. Finally, fluorination improves pharmacokinetic parameters predictive for oral availability.     

Pressure cell for investigations of solid-liquid interfaces by neutron reflectivity

We describe an apparatus for measuring scattering length density and structure of molecular layers at planar solid-liquid interfaces under high hydrostatic pressure conditions. The device is designed for in situ characterizations utilizing neutron reflectometry in the pressure range 0.1-100 MPa at temperatures between 5 and 60?°C. The pressure cell is constructed such that stratified molecular layers on crystalline substrates of silicon, quartz, or sapphire with a surface area of 28 cm(2) can be investigated against noncorrosive liquid phases. The large substrate surface area enables reflectivity to be measured down to 10(-5) (without background correction) and thus facilitates determination of the scattering length density profile across the interface as a function of applied load. Our current interest is on the stability of oligolamellar lipid coatings on silicon surfaces against aqueous phases as a function of applied hydrostatic pressure and temperature but the device can also be employed to probe the structure of any other solid-liquid interface.     

The Dynamic Emission Zone in Sandwich Polymer Light‐Emitting Electrochemical Cells

In light‐emitting electrochemical cells (LECs), the position of the emission zone (EZ) is not predefined via a multilayer architecture design, but governed by a complex motion of electrical and ionic charges. As a result of the evolution of doped charge transport layers that enclose a dynamic intrinsic region until steady state is reached, the EZ is often dynamic during turn‐on. For thick sandwich polymer LECs, a continuous change of the emission color provides a direct visual indication of a moving EZ. Results from an optical and electrical analysis indicate that the intrinsic zone is narrow at early times, but starts to widen during operation, notably well before the electrical device optimum is reached. Results from numerical simulations demonstrate that the only precondition for this event to occur is that the mobilities of anions (μ_a) and cations (μ_c) are not equal, and the direction of the EZ shift dictates μ_c > μ_a. Quantitative ion profiles reveal that the displacement of ions stops when the intrinsic zone stabilizes, confirming the relation between ion movement and EZ shift. Finally, simulations indicate that the experimental current peak for constant‐voltage operation is intrinsic and the subsequent decay does not result from degradation, as commonly stated.     

Modelling crosstalk through common semiconductor layers in AMOLED displays

High pixel density displays are demanded for active matrix organic light‐emitting diode displays (AMOLED) in applications such as virtual reality headsets, micro‐displays, and high‐end smartphones. Parasitic emission from non‐addressed neighboring pixels (crosstalk) is a common problem in such high pixel density AMOLED, and this crosstalk becomes more severe as the pixel density and fill ratio of the display increases. One of the causes of crosstalk is parasitic currents that travel through common organic semiconductor layers. In this paper, we model and quantify the pixel crosstalk using a 2 + 1D finite element model that is based on the conductivity of the common layer and the luminance–current–voltage curves of the subpixels as measured input parameters. We assess the effect of crosstalk on the pixel current, observed color, and luminance. The 2 + 1D model limits the number of degrees of freedom so that calculations on a standard personal computer are feasible.     

Arsenic species in rice and rice-based products consumed by toddlers in Switzerland

Inorganic arsenic (iAs) is a contaminant present in food, especially in rice and rice-based products. Toxicity of arsenic compounds (As) depends on species and oxidative state. iAs species, such as arsenite (As(III)) and arsenate (As(V)), are more bioactive and toxic than organic arsenic species, like methylarsonic acid (MMA(V)) and dimethylarsinic acid (DMA(V)) or arsenosugars and arsenobetaine. An ion chromatography-inductively coupled-plasma-mass spectroscopy method was developed to separate the four following arsenic anions: As(III), As(V), MMA(V) and DMA(V). Sample preparation was done in mild acidic conditions to ensure species preservation. The predominant arsenic species found in rice and rice-based products, except for rice drinks, was As(III), with 60–80% of the total As content, followed by DMA(V) and As(V). MMA(V) was measured only at low levels (<3%). Analyses of rice products (N = 105) intended for toddlers, including special products destined for infants and toddlers, such as dry form baby foods (N = 12) or ready-to-use form (N = 9), were done. It was found in this study that there is little or no margin of exposure. Risk assessment, using the occurrence data and indicated intake scenarios compared to reference BMDLs as established by EFSA, demonstrated toddlers with a high consumption of rice based cereals and rice drinks are at risk of high iAs exposure, for which a potential health risk cannot be excluded.