372 research outputs found

    Development of a tanning technology with Tanning agents from Ligustrum vulgare

    Get PDF
    Content: The use of vegetable tanning agents alone for pre-tanning as an alternative to synthetic or chromiumcontaining tanning agents is one way of improving sustainability and ecology in leather production. In recent years, a new group of secondary plant compounds, the iridoids or secoiridoids, has been discovered for use as tanning agents. Due to their molecular structure, these substances probably have a reaction mechanism similar to glutaraldehyde, which means that known disadvantages of conventional vegetable tanning such as long process times or weak interactions can be avoided. Currently, a tanning agent from olive leaves with cross-linking active substances deriving from the secoiridoid Oleuropein is commercially available. In order to extend the product range of alternative vegetable tanning agents with covalent cross-linking mechanism by native raw material, we screened a number of further plants for such crosslinking active substances in a preceding project. Extracts from privet leaves showed a particularly high crosslinking activity. Privet belongs to the Oleacea family and is common in Asia with several species. In Europe, the species Ligustrum vulgare can be found everywhere, especially as a hedge plant. In addition to Oleuropein, the privet extracts contain a high proportion of the secoiridoid Ligustraloside A. The secoiridoids are deglycosylated during extraction and thus converted into an activated state. The analytical determination of the active secoiridoid degradation products is not yet possible, so that the quantitative determination of the tannin content is made more difficult. Here, we aimed to develop a technology for the production of leather that is exclusively pre- tanned with privet tanning agents. The development includes the production, characterization and optimization of the plant extracts, the development of the pre-tanning technology and the adaptation of the wet end for the corresponding application areas. The leathers which have been manufactured show high shrinkage temperature and good mechanical properties. They show an inherent coloring, but seem to be suitable for use in automotive interiors, as a comparison of the test results with the technical delivery conditions of automobile manufacturers shows. Take-Away: With a new tanning agent from a native widespread plant, leather of good quality can be produced

    Students' Community Service: Self-Selection and the Effects of Participation

    Get PDF
    Numerous studies demonstrate the effectiveness of university-based community service programs on students' personal, social, ethical, and academic domains. These effects depend on both, the characteristics of students enrolled and the characteristics of the programs, for instance whether they are voluntary or mandatory. Our study investigates whether effects of voluntary service programs are indeed caused by the service experience or by prior self-selection. Using data from a pre-post quasi-experimental design conducted at a public university in Europe and taking students' socioeconomic background into account, our findings on self-efficacy, generalized trust, empathic concern, and attributions for poverty show that there are no participation effects. Instead, students who join in community service differ significantly from nonparticipants with regard to almost all investigated domains a priori, indicating strong self-selection. Our results underline the importance of structured group reflection, most notably with regard to attitude-related topics

    Diisopropyl­ammonium methane­sulfonate

    Get PDF
    The title molecular salt, C6H16N+·CH3SO3 −, has been determined at 150 K. Two diisopropyl­ammonium cations (dipH) and two anions form N—H⋯O hydrogen-bonded cyclic dimers lying around centers of symmetry. Only two of the three O atoms of the methane­sulfonate anion are involved in hydrogen bonding, resulting in slightly longer S—O bond lengths. The title structure represents an example of a sulfonate anion that is part of a hydrogen-bonding R 4 4(12) graph-set motif, which is well known for related dipH acetates. Additionally, the Raman and the IR spectroscopic data for the title compound are presented

    Peripheral neural coding strategies for spectral analysis and sound source location in the non-teleost bony fish, Acipenser fulvescens

    Get PDF
    This work is an investigation of coding strategies for spectral analysis and sound source location in Acipenser fulvescens, the lake sturgeon. A. fulvescens belongs to one of the few extant non-teleost ray-finned fishes. The sturgeon taxonomic family, the (Acipenseridae), has a phylogenetic history that dates back about 200 million years. Studies on sensory coding in any species of this family or any other non-teleost species have not been conducted before. Thus, this is the first study on peripheral coding strategies by the auditory system in a non-teleost bony fish. For this study, a shaker system, similar to that used in previous experiments on teleosts, was used to simulate particle motion of sound at the ears and auditory periphery of A. fulvescens. Simultaneously, electrophysiological recordings of isolated single units from the eighth nerve were obtained. Peripheral coding strategies for spectral analysis and sound source location in A. fulvescens resembled those found in teleosts. Frequency data resembled the characteristics found for auditory afferents (with preferences for lower frequencies) in land vertebrates. In addition, the auditory periphery in A. fulvescens appears to be well suited to encode the intensity of sound. In terms of mechanisms for sound source location, eighth nerve afferents responded to directional stimuli in a cosine-like manner (as in teleosts), which can generally serve as the basis for coding the location of a sound source. Certain differences to teleosts were also found in A. fulvescens and these may have implications for the mechanisms for sound source location in azimuth. The common physiological characteristics between A. fulvescens, teleosts, and land vertebrates may reflect important functions (that are part of the process of auditory scene analysis) of the auditory system that have been conserved throughout the evolution of vertebrates

    Civil Society and Its Institutional Context in CEE

    Get PDF
    Although civil societies in Central and Eastern Europe are often portrayed as similar, united by a shared communist past, they have developed along increasingly divergent trajectories over the past three decades. This article investigates the current state of civil society in the region and the role the institutional context plays in it. Drawing on historical institutionalism and the process of European integration, we classify the 14 countries under investigation into three distinct groups and analyze data from a survey of more than 350 local civil society experts. We find that, together with domestic governments, international donors and the EU are perceived as the most influential institutional actors for civil society organizations. Their respective influences, however, depend largely on a country's stage in the EU accession process. Overall, the study provides a differentiated mapping of civil society in this region and a better understanding of how the institutional context relates to a Country's civil society

    Save the Bees, They Prevent Caries

    Get PDF
    Research poster investigating the question: Does the use of natural product based dental products containing propolis provide a decreased risk of caries compared to dental products that are not natural product based? Propolis is a product that is created from bees that is commonly found in a wide variety of natural dental products. Propolis has many beneficial effects; antiviral, antibacterial, antifungal, anticancer, and anti-inflammatory. Dental caries are prominent in children worldwide. Propolis containing products were shown to be as effective in reducing plaque-biofilm as non-natural products.https://dune.une.edu/dh_studpost/1016/thumbnail.jp

    In vitro biocompatibility evaluation of a heat-resistant 3D printing material for use in customized cell culture devices

    Get PDF
    Additive manufacturing (3D printing) enables the fabrication of highly customized and complex devices and is therefore increasingly used in the field of life sciences and biotechnology. However, the application of 3D-printed parts in these fields requires not only their biocompatibility but also their sterility. The most common method for sterilizing 3D-printed parts is heat steam sterilization—but most commercially available 3D printing materials cannot withstand high temperatures. In this study, a novel heat-resistant polyacrylate material for high-resolution 3D Multijet printing was evaluated for the first time for its resistance to heat steam sterilization and in vitro biocompatibility with mouse fibroblasts (L929), human embryonic kidney cells (HEK 293E), and yeast (Saccharomyces cerevisiae (S. cerevisiae)). Analysis of the growth and viability of L929 cells and the growth of S. cerevisiae confirmed that the extraction media obtained from 3D-printed parts had no negative effect on the aforementioned cell types, while, in contrast, viability and growth of HEK 293E cells were affected. No different effects of the material on the cells were found when comparing heat steam sterilization and disinfection with ethanol (70%, v/v). In principle, the investigated material shows great potential for high-resolution 3D printing of novel cell culture systems that are highly complex in design, customized and easily sterilizable—however, the biocompatibility of the material for other cell types needs to be re-evaluated

    Feasibility Study of Neoadjuvant Olaparib for Frontline BRCA Mutant Ovarian Cancer

    Get PDF
    https://openworks.mdanderson.org/sumexp22/1095/thumbnail.jp

    Versatile Genetic Tool Box for the Crenarchaeote Sulfolobus acidocaldarius

    Get PDF
    For reverse genetic approaches inactivation or selective modification of genes are required to elucidate their putative function. Sulfolobus acidocaldarius is a thermoacidophilic Crenarchaeon which grows optimally at 76°C and pH 3. As many antibiotics do not withstand these conditions the development of a genetic system in this organism is dependent on auxotrophies. Therefore we constructed a pyrE deletion mutant of S. acidocaldarius wild type strain DSM639 missing 322 bp called MW001. Using this strain as the starting point, we describe here different methods using single as well as double crossover events to obtain markerless deletion mutants, tag genes genomically and ectopically integrate foreign DNA into MW001. These methods enable us to construct single, double, and triple deletions strains that can still be complemented with the pRN1 based expression vector. Taken together we have developed a versatile and robust genetic tool box for the crenarchaeote S. acidocaldarius that will promote the study of unknown gene functions in this organism and makes it a suitable host for synthetic biology approaches
    corecore