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931.
932.
Alexandra Lymberopoulou-Karaliota Despina Hatzipanayioti Marianna Potamianou Vasilios Aletras 《Inorganica chimica acta》2005,358(11):2975-2995
Dimeric or oligomeric oxo-complexes of Mo(VI) with 2,3-dihydroxybenzoic acid were prepared in aqueous solutions in the presence or not of K2S2O5 (acting as a reducing agent) in various conditions. The complexes were found to contain the cis-(Mo2O5)2+ core and the ligands in the catecholate, semiquinonate or mixed valence oxidation form, depending on the reaction conditions and especially on the presence or not of the reductant. The isolated complexes in the presence or absence of reductant and the oxidation products in solution in the presence of air were studied via elemental, thermogravimetric and electrochemical analysis, Infrared, Raman, NMR and ESR spectroscopies and Electrospray Mass Spectra. The general molecular formula for the complexes is {[(PPh4)2(Mo2O5L2X2] · xH2O)}n, where the coordinated ligand’s L oxidation form varies and X involves coordinated water or hydroxyl group depending on the ligand oxidation state. 相似文献
933.
Carmela Mennella Marianna Visciano Aurora Napolitano Maria Dolores Del Castillo Vincenzo Fogliano 《Journal of peptide science》2006,12(4):291-296
Protein glycation through Maillard reaction (MR) is a fundamental reaction both in foods and in the human body. The first step of the reaction is the formation of Amadori product (AP) that is converted into intermediate and advanced MR products during reaction development. Although the MR is not an enzymatic reaction, a certain degree of specificity in the glycation site has been observed. In the present study, we have monitored the glycation of different lysine-containing dipeptides to evaluate the influence on the NH(2) reactivity of the neighboring amino acid.Lysine dipeptides were reacted with glucose, galactose, lactose and maltose. The formation and identification of glycated compounds were monitored by mass spectrometry (MALDI-TOF and ESI-MS/MS) and by HPLC of their Fmoc derivatives. MS/MS analysis showed that the glucose APs formed on dipeptides have a characteristic fragmentation pattern: the fragment at [M - 84](+) due to the formation of pyrylium and furylium ion is mainly present in the monoglucosylated form, while the [M - 162](+) and the [M - 324](+) are more evident in the fragmentation pattern of the diglucosylated forms.The nature of the vicinal amino acids strongly affects lysine reactivity towards the different carbohydrates: the presence of hydrophobic residues such as Ile, Leu, Phe strongly increases lysine reactivity. Contrasting results were obtained with basic residues. The Lys-Arg dipeptide was among the most reactive while the Lys-Lys was not. 相似文献
934.
Claudia Angelini Luisa Cutillo Daniela De Canditiis Margherita Mutarelli Marianna Pensky 《BMC bioinformatics》2008,9(1):415
Background
Gene expression levels in a given cell can be influenced by different factors, namely pharmacological or medical treatments. The response to a given stimulus is usually different for different genes and may depend on time. One of the goals of modern molecular biology is the high-throughput identification of genes associated with a particular treatment or a biological process of interest. From methodological and computational point of view, analyzing high-dimensional time course microarray data requires very specific set of tools which are usually not included in standard software packages. Recently, the authors of this paper developed a fully Bayesian approach which allows one to identify differentially expressed genes in a 'one-sample' time-course microarray experiment, to rank them and to estimate their expression profiles. The method is based on explicit expressions for calculations and, hence, very computationally efficient. 相似文献935.
Bak Marianna I.; Ingwall Joanne S. 《American journal of physiology. Cell physiology》1998,274(4):C992
The ability toresynthesize ATP during recovery from ischemia is limited tothe size of endogenous pool of adenine nucleotides. CytosolicAMP-specific 5'-nucleotidase (5'-NT) plays a key role inATP degradation and hence the capacity for ATP resynthesis. We havesuggested (J. Clin. Invest. 93:40-49, 1994) that intracellular acidosis [intracellular pH(pHi)] is a potentinhibitor of 5'-NT under in vivo conditions. To test thishypothesis further, we used the hyperthyroid rat heart because we couldalter pHi during ischemiaand determine the consequences of lowerpHi on AMPaccumulation (by chemical assay) and ATP resynthesis (by31P nuclear magnetic resonancespectroscopy) during reperfusion. Global no-flow ischemiacaused pHi to decrease from 7.1 under well-oxygenated control perfusion to 6.7. We found thatdecreasing pHi further from pH 6.7 to 6.4 leads to increased accumulation (30%) of AMP duringischemia and to a 2.5-fold increase in ATP resynthesis duringreperfusion. Analysis of all known substrates, products, activators,and inhibitors of the 5'-NT suggests that 5'-NT isactivated primarily by Mg2+ andADP and is inhibited by H+. Thusthese observations provide evidence for a salutary effect ofintracellular acidosis on preserving the AMP pool due to inhibition of5'-NT and suggest a novel role ofH+ in protecting ischemic tissue. 相似文献
936.
Genetic and endocrine control of renin activity in the submaxillary gland of the mouse 总被引:2,自引:0,他引:2
Carol M. Wilson Marianna Cherry Benjamin A. Taylor Jean D. Wilson 《Biochemical genetics》1981,19(5-6):509-523
Basal activity of submaxillary gland (SMG) renin is high in female mice that carry the Rnr
s allele and is induced to higher levels by treatment with dihydrotestosterone (DHT). To determine whether the difference in basal activity between high (Rnr
s/Rnrs) and low (Rnr
b/Rnrb) strains is due to enhanced sensitivity of Rnr
s/Rnrs strains to endogenous androgen, we first studied the effect of several types of endocrine ablation on SMG renin in young female mice, and second, we removed normal androgen receptor protein by introducing the X-linked Tfm gene. Adrenalectomy with or without castration had no effect on basal SMG renin; hypophysectomy decreased basal renin activity 400-fold but did not abolish responsiveness to DHT. Loss of androgen receptor did not affect basal renin activity but did prevent enhancement by DHT. Basal and induced renin activities in L.AKR(Alll)/Cy, a congenic strain homozygous for Rnr
s introduced from AKR/J into the background of C57L/J, an Rnr
b/Rnrb type strain, are intermediate between levels observed in the original strains. We conclude that (1) the basal level of SMG renin is regulated directly or indirectly by some pituitary hormone(s) but not by androgen, (2) androgen induction of renin activity requires a normal androgen receptor, and (3) major gene(s) that regulate basal as well as induced SMG renin are in a circumscribed region of chromosome 1.This work has been aided by Grants GM26414 and AM03892 from the National Institutes of Health, a grant from the Texas affiliate of the American Heart Association, and by research contract NO1-CP33255 from the Division of Cancer Cause and Prevention, the National Cancer Institute. The Jackson Laboratory is fully accredited by the American Association for Accreditation of Laboratory Animal Care. 相似文献
937.
Habitat discrimination of juvenile sardines in the Aegean Sea using remotely sensed environmental data 总被引:1,自引:0,他引:1
Konstantinos Tsagarakis Athanassios Machias Stylianos Somarakis Marianna Giannoulaki Andreas Palialexis Vasilis D. Valavanis 《Hydrobiologia》2008,612(1):215-223
Despite the importance of the recruitment process for small pelagic fish and the high economic importance of European sardine
(Sardina pilchardus, Walbaum 1792) in the Mediterranean Sea, knowledge on the distribution and environmental characteristics of its nursery grounds
is very limited. In the present study, we used pelagic trawl data collected during 1995–2006 to explore the spatial distribution
of sardine juveniles in the Aegean Sea in early summer. Based on sardine abundance per length class, a cluster analysis was
initially used to define hauls dominated by juveniles. In a subsequent step, Discriminant Function Analysis (DFA) was applied
to discriminate stations with high relative abundance of juveniles using satellite environmental data and bottom depth. The
parameters contributing mostly to the discrimination of juvenile grounds were sea level anomaly, photosynthetically active
radiation, sea surface temperature, chlorophyll-α and bottom depth. The classification functions of DFA were finally used
to post classify unsampled areas in the Greek Seas and the Mediterranean Sea in order to map grounds that meet characteristic
environmental conditions for young sardine. Such areas were mostly located inshore, in semi-closed productive areas and often
in proximity to river mouths, a pattern that is generally supported by existing information.
Guest editor: V. D. Valavanis
Essential Fish Habitat Mapping in the Mediterranean 相似文献
938.
Marianna Zahurak Giovanni Parmigiani Wayne Yu Robert B Scharpf David Berman Edward Schaeffer Shabana Shabbeer Leslie Cope 《BMC bioinformatics》2007,8(1):142