The analysis of tar, mostly characterized as polycyclic aromatic hydrocarbons (PAHs), describes a topic that has been researched for years. An online analysis of tar in the gas stream in particular is needed to characterize the tar conversion or formation in the biomass gasification process. The online analysis in the gas is carried out with ultraviolet-visible (UV-Vis) spectroscopy (190-720 nm). This online analysis is performed with a measuring cell developed by the Fraunhofer Institute for Chemical Technology (ICT). To this day, online tar measurements using UV-Vis spectroscopy have not been carried out in detail. Therefore, PAHs are analyzed as follows. The measurements are split into different steps. The first step to prove the online method is to vaporize single tar substances. These experiments show that a qualitative analysis of PAHs in the gas stream with the used measurement setup is possible. Furthermore, it is shown that the method provides very exact results, so that a differentiation of various PAHs is possible. The next step is to vaporize a PAH mixture. This step consists of vaporizing five pure substances almost simultaneously. The interpretation of the resulting data is made using a chemometric interpretation method, the multivariate curve resolution (MCR). The verification of the calculated results is the main aim of this experiment. It has been shown that the tar mixture can be analyzed qualitatively and quantitatively (in arbitrary units) in detail using the MCR. Finally it is the main goal of this paper to show the first steps in the applicability of the UV-Vis spectroscopy and the measurement setup on online tar analysis in view of characterizing the biomass gasification process. Due to that, the gasification plant (at the laboratory scale), developed and constructed by the Fraunhofer ICT, has been used to vaporize these substances. Using this gasification plant for the experiments enables the usage of the measurement setup also for the spectroscopic analysis of the tar formation during the biomass gasification.
The oviduct epithelium undergoes marked morphological and functional changes during the estrous cycle. It has been shown that a dramatic change in the frequencies of ciliated and non-ciliated cells occurs during the estrous cycle. At estrus the epithelium consists of secretory and ciliated cells and at diestrus mainly of ciliated cells. The oviduct provides the microenvironment for sperm capacitation, fertilization, and early cleavage-stage embryonic development. At the molecular level, only a few genes or proteins are known that change during the estrous cycle and which may be important for fertility, so as the bovine oviduct-specific glycoprotein, the major secretory protein in the oviduct. Therefore, we studied systematically the changes in gene expression in bovine ipsilateral oviduct epithelial cells at estrus and diestrus. To identify differentially expressed genes, a combination of subtracted cDNA libraries and cDNA array hybridization was used. Two subtracted libraries were produced to enrich cDNAs of upregulated genes at estrus and at diestrus. A total of 1536 cDNA clones of each library were analyzed with radioactively (33-P) labeled probes generated from the oviduct epithelial cells of six Simmental heifers, three of them slaughtered at Day 0 (estrus) and three at Day 12 after standing heat (diestrus). After normalization of the raw data and statistical analysis, all cDNAs showing significant differences in their expression levels at estrus compared to diestrus were sequenced. Sequencing revealed 84 different cDNAs; 42 of them matched bovine genes or their human/mouse homologs with known functions, and 42 matched genes without a known function. Half of the genes (n = 42) were expressed at a higher level at estrus; for the other (n = 42) expression levels were higher at diestrus. The regulated genes or their products represented a variety of functional classes, such as genes of the secretory pathway, genes involved in transcription regulation, cell-surface proteins, cell-cell interaction proteins, secreted proteins, members of signal transduction pathways, immune-related proteins, and some enzymes. The identification of genes differentially regulated in ipsilateral oviduct epithelial cells at estrus v. diestrus is the first step of a systematic analysis of differential gene expression during the estrous cycle. Further studies will follow, focusing on different compartments of the bovine oviduct and additional times of the estrous cycle.
EXPRESSION PATTERN OF CERTAIN DEVELOPMENTALLY IMPORTANT GENES IN BOVINE NUCLEAR TRANSFER EMBRYOS PRODUCED USING CELL LINES OF DIFFERENT EFFICIENCY
Z. Beyhan and N.L. FirstDepartment of Animal Science, University of Wisconsin-Madison, WI, USA. email: zbeyhan@wisc.edu Developmental abnormalities associated with the cloning process suggest that reprogramming of donor nuclei into an embryonic state may not be fully completed in most of the cloned animals. One of the areas of interest in this respect is the analysis of gene expression patterns in nuclear transfer embryos to ...
On the occasion of the XIIIth International Symposium on Spermatology held from 9 to 13 May 2018 in Stockholm (Sweden), participants (guest speakers and audience) collectively felt the need to make a public statement on the general issue of male reproductive health. Our intention is to raise awareness of what we believe is a neglected area of research despite alarming situations around the world. The disclosure strategy desired by the co-authors is to bring it to the attention of the greatest number partly by considering co-publication in the various periodicals dealing with Reproductive Biology and Andrology. BaCA’s editorial office accepted this mission and found it natural that our periodical, the official journal of the French Andrology Society (SALF), should carry this message.
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