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991.
Azuka N. Iwobi Ingrid Huber Georg Hauner Andreas Miller Ulrich Busch 《Food Analytical Methods》2011,4(3):389-398
The verification of declared components in meat products is an essential task of food control agencies worldwide. To date,
the ELISA and species-specific polymerase chain reaction (PCR) are two commonly applied analytical tools employed by many
authorized food control laboratories. These trusted methods however do not allow the simultaneous detection of all the animal
species present in a meat sample. Additionally, detection of undeclared components resulting from inadvertent contamination
or deliberate adulteration of the meat products requires additional processing of the samples, resulting in increased expenditure.
The use of DNA biochip analysis that allows simultaneous processing of many meat products, while concomitantly generating
results for the detection of all animal species present in the meat products is thus highly desirable. In this work, two commercially
available animal chip detection systems (CarnoCheck Test Kit and MEATspecies LCD Array) are compared in terms of sensitivity, robustness, reproducibility, and ease of handling. The two animal species
differentiation biochip methods compared well in efficiency and could simultaneously detect from eight to 14 animal species
in the meat products. Detection limits were found to be in the range of 0.1% to 0.5% in meat admixtures, with good reproducibility
of results. More than 70 commercially available meat samples were analyzed in this work, with the results validated against
traditional PCR methodology. Both biochip methods performed well and could be implemented for routine use in any food control
agency. 相似文献
992.
Katharina Lommel Dr. Gabriela Schäfer Konstantin Grenader Christoph Ruland Prof. Dr. Andreas Terfort Prof. Dr. Werner Mäntele Dr. Georg Wille 《Chembiochem : a European journal of chemical biology》2013,14(3):372-380
CO2‐consuming reactions, in particular carboxylations, play important roles in technical processes and in nature. Their kinetic behavior and the reaction mechanisms of carboxylating enzymes are difficult to study because CO2 is inconvenient to handle as a gas, exists in equilibrium with bicarbonate in aqueous solution, and typically yields products that show no significant spectroscopic differences from the reactants in the UV/Vis range. Here we demonstrate the utility of 3‐nitrophenylacetic acid and related compounds (caged CO2) in conjunction with infrared spectroscopy as widely applicable tools for the investigation of such reactions, permitting convenient measurement of the kinetics of CO2 consumption. The use of isotopically labeled caged CO2 provides a tool for the assignment of infrared absorption bands, thus aiding insight into reaction intermediates and mechanisms. 相似文献
993.
Roman Günthner Vankayala Ramaiah Santhosh Kumar Georg Lorenz Hans-Joachim Anders Maciej Lech 《International journal of molecular sciences》2013,14(9):18124-18147
The cell type-, organ-, and species-specific expression of the pattern-recognition receptors (PRRs) are well described but little is known about the respective expression profiles of their negative regulators. We therefore determined the mRNA expression levels of A20, CYLD, DUBA, ST2, CD180, SIGIRR, TANK, SOCS1, SOCS3, SHIP, IRAK-M, DOK1, DOK2, SHP1, SHP2, TOLLIP, IRF4, SIKE, NLRX1, ERBIN, CENTB1, and Clec4a2 in human and mouse solid organs. Humans and mice displayed significant differences between their respective mRNA expression patterns of these factors. Additionally, we characterized their expression profiles in mononuclear blood cells upon bacterial endotoxin, which showed a consistent induction of A20, SOCS3, IRAK-M, and Clec4a2 in human and murine cells. Furthermore, we studied the expression pattern in transient kidney ischemia-reperfusion injury versus post-ischemic atrophy and fibrosis in mice. A20, CD180, ST2, SOCS1, SOCS3, SHIP, IRAK-M, DOK1, DOK2, IRF4, CENTB1, and Clec4a2 were all induced, albeit at different times of injury and repair. Progressive fibrosis was associated with a persistent induction of these factors. Thus, the organ- and species-specific expression patterns need to be considered in the design and interpretation of studies related to PRR-mediated innate immunity, which seems to be involved in tissue injury, tissue regeneration and in progressive tissue scarring. 相似文献
994.
Sarah Schneider Mariana Gutiérrez Tatyana Sandalova Dr. Gunter Schneider Prof. Dr. Pere Clapés Dr. Georg A. Sprenger Prof. Dr. Anne K. Samland Dr. 《Chembiochem : a European journal of chemical biology》2010,11(5):681-690
Recently, we reported on a transaldolase B variant (TalB F178Y) that is able to use dihydroxyacetone (DHA) as donor in aldol reactions. In a second round of protein engineering, we aimed at improving the affinity of this variant towards nonphosphorylated acceptor aldehydes, that is, glyceraldehyde (GA). The anion binding site was identified in the X‐ray structure of TalB F178Y where a sulfate ion from the buffer was bound in the active site. Therefore, we performed site‐directed saturation mutagenesis at three residues forming the putative phosphate binding site, Arg181, Ser226 and Arg228. The focused libraries were screened for the formation of D ‐fructose from DHA and d,l ‐GA by using an adjusted colour assay. The best results with respect to the synthesis of D ‐fructose were achieved with the TalB F178Y/R181E variant, which exhibited an at least fivefold increase in affinity towards d,l ‐GA (KM=24 mM ). We demonstrated that this double mutant can use D ‐GA, glycolaldehyde and the L ‐isomer, L ‐GA, as acceptor substrates. This resulted in preparative synthesis of D ‐fructose, D ‐xylulose and L ‐sorbose when DHA was used as donor. Hence, we engineered a DHA‐dependent aldolase that can synthesise the formation of polyhydroxylated compounds from simple and cheap substrates at preparative scale. 相似文献
995.
Tobias Krüger Dr. Stefanie Weiland Mareile Boschanski Dr. Prem Kumar Sinha Georg Falck Prof. Dr. Kristian M. Müller Prof. Dr. Thomas Dierks Prof. Dr. Norbert Sewald 《Chembiochem : a European journal of chemical biology》2019,20(16):2074-2078
Formylglycine-generating enzymes provide a convenient tool for site-specific protein derivatization. Their ability to oxidize cysteine or serine residues within a defined consensus sequence to Cα-formylglycine (FGly) allows for the targeted introduction of a unique chemical handle for various bioconjugation reactions. In recent years, oxygen-dependent FGly-generating enzyme saw broad use in protein functionalization and the generation of protein conjugates. Yet, the FGly-generating system AtsB, along with its capability to convert unusual aldehyde tag sequences, remains mostly unused. Herein, the ability of AtsB from Methanosarcina mazei to convert nonclassical aldehyde tags of the SX(A/P)XR-type and its potential use in bioconjugation chemistry are demonstrated. 相似文献
996.
We consider the numerical approximation of volume integrals over bounded domainsD:={D∈R 3:H(x>≤0}, whereH:R 3→R is a suitable decidability function. The integrands may be smooth maps or singular maps such as those arising in the volume potentials for boundary integral methods. An adaptive extrapolation method is described which is based on some simple quadrature rules. It utilizes an automatic simplicial subdivision of the domain. The method offers improvements over recently given approaches. A special version is offered for the important application of the numerical computation of volume potentials in boundary integral methods. Several examples illustrate the performance of the method. 相似文献
997.
998.
The power‐to‐gas process is an option to transform fluctuating renewable electric energy into methane via water electrolysis and subsequent conversion of H2 by methanation with CO2. The dynamic behavior of the methanation reactor may then be a critical aspect. The kinetics of CO2 methanation on a Ni‐catalyst were determined under isothermal and stationary conditions. Transient isothermal kinetic experiments showed a fast response of the rate on step changes of the concentrations of H2, CO2; in case of H2O, the response was delayed. Non‐isothermal experiments were conducted in a wall‐cooled fixed‐bed reactor. Temperature profiles were measured and the effect of a changing volumetric flow was studied. The experimental data were compared with simulations by a transient reactor model. 相似文献
999.
Hydrogels: One Step Creation of Multifunctional 3D Architectured Hydrogels Inducing Bone Regeneration (Adv. Mater. 10/2015) 下载免费PDF全文
1000.