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131.
The introduction of deuterated and partially deuterated protein samples has greatly facilitated the 13C assignment of larger proteins. Here we present a new version of the HC(CO)NH-TOCSY experiment, the ed-H(CCO)NH-TOCSY experiment for partially deuterated samples, introducing a multi-quantum proton evolution period. This approach removes the main relaxation source (the dipolar coupling to the directly bound 13C spin) and leads to a significant reduction of the proton and carbon relaxation rates. Thus, the indirect proton dimension can be acquired with high resolution, combined with a phase labeling of the proton resonances according to the C-C spin system topology. This editing scheme, independent of the CHn multiplicity, allows to distinguish between proton side-chain positions occurring within a narrow chemical shift range. Therefore this new experiment facilitates the assignment of the proton chemical shifts of partially deuterated samples even of high molecular weights, as demonstrated on a 31 kDa protein. 相似文献
132.
Decoupling the retention time of easily degradable and persistent substances using ultrafiltration membranes increases biogas production yield 下载免费PDF全文
Anja Schreiber Gerd‐Rainer Vollmer Uta Breuer Michael Nelles 《Engineering in Life Science》2016,16(1):60-66
The decoupling of the retention time of easily degradable and persistent substances relieves the degradation process from inhibitors and increases the biogas yield. Anaerobic digestion of maize silage was investigated in a pilot‐scale plant with a coupled ultrafiltration membrane. The aim of the study was the evaluation of the influence of the membrane‐based relief of the degradation process and the increase of the retention time of persistent substances. For that purpose, the fermenter content was separated into solid and liquid fractions. The solid fraction was recirculated to the fermenter for longer retention time and higher substrate degradation rates. The fermentation process was improved by the removal of the liquid fraction and adding volatile fatty acids. The results showed an increase of the biogas yield by 7.2% in comparison to the anaerobic digestion without membrane filtration. 相似文献
133.
Zeno Fldes-Papp Gerd Baumann Eckhard Birch-Hirschfeld Holger Eickhoff Karl Otto Greulich Albrecht K. Kleinschmidt Hartmut Seliger 《Biopolymers》1998,45(5):361-379
In this paper we put forward improved mathematical methods for detecting synthesis parameters in connection with analyzing crude products of chemically synthesized oligonucleotides. The crude products experimentally sampled are separated by high-performance capillary electrophoresis and ion-exchange high-performance liquid chromatography. The measured separation profiles of experimental syntheses can be expressed as target and nontarget yields; they are characterized by a few parameters. These parameters account for nonlinear synthesis equations that are solvable by employing iteration procedures. We provide here a theoretical as well as computational analysis based upon specific models for stepwise chain growth. Under nonconstant (nonuniform) conditions we use here an exponential form of growth, with different expressions for calculating the fractal dimension of the biochemical process under study. Step lengths of parameter variations in an interval of finite length have to be adjusted properly to find convergent solutions in a mathematical, regularly four-dimensional parameter space. It is conceivable to have most, if not all, of the calculating and plotting carefully done by a computer. This analysis represents the experimental situation up to 65-mer target oligonucleotides analyzed so far. We thus obtain the dynamics of the polymerization process limited in number by fractal models. The advantage, calculating these new methods as compared to qualitatively judged experimental methods, lies in the satisfactory evaluation of crude products, also of large amounts, of syntheses of these biopolymers. © 1998 John Wiley & Sons, Inc. Biopoly 45: 361–379, 1998 相似文献
134.
Gerd Gäde 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1989,159(5):589-596
Summary Extracts of corpora cardiaca from two members of the family Tenebrionidae,Zophobas rugipes andTenebrio molitor, from one member of the Chrysomelidae,Leptinotarsa decemlineata, and from three members of the Scarabaeidae,Pachnoda marginata, P. sinuata andMelolontha hippocastani, were assayed for adipokinetic and hypertrehalosaemic activity in acceptor locusts (Locusta migratoria) and cockroaches (Periplaneta americana), respectively. All corpus cardiacum material tested, except that from the cockchafer,M. hippocastani, gave positive bioassay results. Biological activities of corpus cardiacum extracts from all species investigated can be resolved on reversed-phase high performance liquid chromatography (RP-HPLC). Gland extracts from the two tenebrionid species each show a single peak of biological activity associated with a single peak of UV absorbance having an identical retention time in both species. The two biologically active fractions from the corpora cardiaca of the potato beetle,L. decemlineata, coelute with exogenous (synthetic) hypertrehalosaemic hormones I and II of the American cockroach. The two species of the genusPachnoda contain two active compounds in their glands; compound I of each species is more abundant and elutes just ahead of the (synthetic) hypertrehalosaemic hormone of the cockroachBlaberus discoidalis. The gland material ofM. hippocastani exhibits and absorbance peak with the same retention time as the major peak from thePachnoda-species; however, this peak material does not elicit biological activity in the assays used here. After fractionation by RP-HPLC the main biologically active compounds were subjected to amino acid analyses. All factors are peptidic and contain 8 amino acid residues. The peptides from the tenebrionid species have the amino acid residues Asx(2), Glx(1), Ser(1), Pro(1), Leu(1), Phe(1) and Trp(i), whereas the main peptide from corpora cardiaca ofP. marginata contains the residues Asx(2), Glx(1), Ser(1), Pro(1), Tyr(1), Leu(1) and Trp(1). Amino acid composition analyses of the two active fractions fromL. decemlineata reveal the residues Asx(2), Glx(1), Ser(1), Pro(1), Val(1), Phe(1) and Trp(1) for compound I and Asx(1), Glx(1), Thr(2), Pro(1), Leu(1), Phe(1) and Trp(1) for compound II. 相似文献
135.
136.
Ralf W. Dittmann Peter M. Wehmeier Alexander Schacht Martin Lehmann Gerd Lehmkuhl 《Attention deficit and hyperactivity disorders》2009,1(2):187-200
To report on (1) psychometric properties of the Rosenberg Self-Esteem Scale (SES) studied in adolescents with ADHD, (2) correlations of SES with ADHD scale scores, and (3) change in patient-reported self-esteem with atomoxetine treatment. ADHD patients (12–17 years), treated in an open-label study for 24 weeks. Secondary analyses on ADHD symptoms (assessed with ADHD-RS, CGI, GIPD scales) and self-esteem (SES) were performed. One hundred and fifty-nine patients were treated. A dichotomous structure of the SES could be confirmed. Reliability and internal consistency were moderate to excellent. Highest coefficients were found for the correlation between SES and GIPD scores. Self-esteem significantly increased over time, accompanied by an improvement of ADHD symptoms and related perceived difficulties. The Rosenberg SES was shown to be internally consistent, reliable, and sensitive to treatment-related changes of self-esteem. According to these findings, self-esteem may be an important individual patient outcome beyond the core symptoms of ADHD. 相似文献
137.
Campagnolo C Meyers KJ Ryan T Atkinson RC Chen YT Scanlan MJ Ritter G Old LJ Batt CA 《Journal of biochemical and biophysical methods》2004,61(3):283-298
Conventional techniques for the detection of biomolecular interactions can be limited by the need for exogenous labels, time- and labor-intensive protocols, as well as by poor sensitivity levels. A refractometer instrument has been reconfigured to detect biomolecular interactions through changes in surface plasmon resonance (SPR). The binding kinetics and affinity values of anti-NY-ESO-1 monoclonal antibody, ES121, to the cancer-testis antigen NY-ESO-1 were determined according to the surface heterogeneity model and resulted in K(D) values of 1.3x10(-9) and 2.1x10(-10) M. The reconfigured instrument was then used to measure the interaction between tumor antigens and serum antibodies against these antigens in preselected cancer patient sera samples. The tumor antigens assayed included NY-ESO-1, SSX2 and p53, all used as recombinant proteins containing polyhistidine tags. These results demonstrated that the instrument is capable of detecting the binding of serum antibodies from cancer patient sera to immobilized tumor antigens, consistent with those observed previously in ELISA-based experiments. These results demonstrate the potential of SPR technology for the rapid diagnosis and monitoring immune responses. 相似文献
138.
Johannes Ingrisch Stefan Karlowsky Alba Anadon-Rosell Roland Hasibeder Alexander König Angela Augusti Gerd Gleixner Michael Bahn 《Ecosystems》2018,21(4):689-703
Climate extremes and land-use changes can have major impacts on the carbon cycle of ecosystems. Their combined effects have rarely been tested. We studied whether and how the abandonment of traditionally managed mountain grassland changes the resilience of carbon dynamics to drought. In an in situ common garden experiment located in a subalpine meadow in the Austrian Central Alps, we exposed intact ecosystem monoliths from a managed and an abandoned mountain grassland to an experimental early-summer drought and measured the responses of gross primary productivity, ecosystem respiration, phytomass and its components, and of leaf area index during the drought and the subsequent recovery period. Across all these parameters, the managed grassland was more strongly affected by drought and recovered faster than the abandoned grassland. A bivariate representation of resilience confirmed an inverse relationship of resistance and recovery; thus, low resistance was related to high recovery from drought and vice versa. In consequence, the overall perturbation of the carbon cycle caused by drought was larger in the managed than the abandoned grassland. The faster recovery of carbon dynamics from drought in the managed grassland was associated with a significantly higher uptake of nitrogen from soil. Furthermore, in both grasslands leaf nitrogen concentrations were enhanced after drought and likely reflected drought-induced increases in nitrogen availability. Our study shows that ongoing and future land-use changes have the potential to profoundly alter the impacts of climate extremes on grassland carbon dynamics. 相似文献
139.
André Overmeyer Sandra Schrader-Lippelt Volker Kasche Gerd Brunner 《Biotechnology letters》1999,21(1):65-69
The reaction rate and selectivity of the enzymatic kinetic resolution of ibuprofen and 1-phenylethanol with supercritical CO2 as solvent were studied in a batch reactor from 40 °C to 160 °C. The commercial enzyme, Novozym 435, remained partly active for at least 14 h up to 140 °C at 15 MPa. The maximum reaction rate for the esterification of 1-phenylethanol and ibuprofen was at about 90 °C. The enantiomeric excess for 1-phenylethanol exceeds 99% and was temperature independent. Selectivity for ibuprofen esterification reached a lower enantiomeric excess of 61% caused by equilibrium adjustment. The results show that with supercritical CO2 as reaction medium enzymes remain active above 100 °C. 相似文献
140.
Marcus Jäger Frank Peter Tillmann Thomas S Thornhill Marcus Mahmoudi Dirk Blondin Rüdiger Gerd Hetzel Christoph Zilkens Rüdiger Krauspe 《Arthritis research & therapy》2008,10(5):1-14