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71.
Bisi A Rampa A Budriesi R Gobbi S Belluti F Ioan P Valoti E Chiarini A Valenti P 《Bioorganic & medicinal chemistry》2003,11(7):1353-1361
The synthesis and pharmacological profile of some hybrid compounds bearing both the benzazepinone moiety present in Zatebradine and typical beta-blocker aryloxypropanolamine groups are described. The new compounds proved to be endowed with negative chronotropic and inotropic activity and are weak vasorelaxant agents. The cardiodepressant action is probably due to selective beta(1)-noncompetitive reversible antagonism. Both enantiomers of the most active compound 5c were synthesized and they showed a different cardiovascular profile, that is (+)-(R)-enantiomer displays affinity for cardiac beta(1)-adrenoceptors, while (-)-(S)-enantiomer shows specificity for vessel smooth muscle. 相似文献
72.
73.
Assoc. Prof. Dr. Ioan I. Bucur Dr. Carol Strutinski Dipl. Geol. Dana Pop-Stratila 《Facies》1994,30(1):85-100
Summary The Sasca zone situated in the innermost part of the Getic Domain from the South Carpathians comprises mainly Triassic deposits
of Scythian-Anisian (?Ladinian) age that can be ascribed to four different members forming the Sasca Formation. Three of the
members consist of carbonate deposits. Their study permitted a brief characterization of the main microfacies types, and especially
in the Valea Susara Limestone Member the identification of a relatively rich association of foraminifers and calcareous algae.
The assemblage withMeandrospira dinarica, Pilammina densa, Oligoporella pilosa andPoncetella hexaster identified in these limestones indicates a Middle Anisian age (Pelsonian-Lowermost Illyrian). Difficulties arise in differentiating
between the forms belonging to theOligoporella-Physoporella group for which a taxonomic revision is necessary. The morphologic characteristics of the three varieties ofDiplopora subtilis allow a splitting into different species.Teutloporella peniculiformis
Ott, 1963 is regarded as anomen nudum. 相似文献
74.
I Lascu T Barzu N G Ty L D Ngoc O Barzu H H Mantsch 《Biochimica et biophysica acta》1977,482(2):251-260
A total of 26 different purine nucleotides with specific modifications in the base moiety and/or in the polyphosphate chain as well as various combinations of nucleotides were tested as allosteric effectors of beef liver glutamate dehydrogenase (L-glutamate : NAD(P)+ oxidoreductase (deaminating), EC 1.4.1.3). The capacity of these nucleotide analogs to activate or to inhibit the glutamate dehydrogenase activity is expressed quantitatively and scaled between the extreme effects of ADP and GTP, respectively. The significance of distinct structural elements for the enzyme-effector interaction is discussed. While the inhibitory GTP site is less specific, accepting many natural and most modified nucleoside triphosphates as inhibitors, the activating ADP site shows a much higher specificity for nucleotides as activators. 相似文献
75.
Dr. Ioan Davies 《Cell and tissue research》1977,184(4):529-538
Summary The ultrastructure of mid-gut cells of female Nasonia fed on a diet of 10% sterile sucrose is described. There are extensive alterations in cell organelles, particularly the mitochondria, rough endoplasmic reticulum (R.E.R.) and lipid inclusions, when compared to similar insects fed a normal diet of dipteran pupae. A proportion of the mitochondria found in the apical cell region are enlarged in size and contain electron-dense granules. The remaining mitochondria are smaller, but also contain electron-dense granules. Cytochrome-c oxidase activity appears to be absent from the enlarged mitochondria. The R.E.R. appears reduced in many cells of the 1 day old, sugar-fed insects, however, this component fluctuates throughout the remaining life span. The lipid inclusions prominent in the 1 day old, pupae-fed insects are not present in sucrose-fed females of the same age, but lipid deposition was recorded later in the life span. There are many large residual bodies and cytolysosomes present in the old, sugar-fed insects. These changes in ultrastructure are discussed in relation to diet and longevity. 相似文献
76.
Boido A Budriesi R Boido CC Ioan P Terranova E Chiarini A Sparatore F 《化学与生物多样性》2005,2(10):1290-1304
A series of pharmacologically interesting 1- and 2-[omega-(4-arylpiperazin-1-yl)alkyl]-1,2,3-benzotriazoles, compounds 1-27, were synthesized (Scheme) and subjected to various biological studies to identify structure-activity relationships (SAR). The new compounds were found to exhibit good non-selective binding affinity towards the alpha1-adrenoreceptor (Table 1). In several cases, high functional antagonism was observed towards the alpha1A-, alpha1B-, and alpha1D-adrenoreceptor subtypes (Table 2). The selectivity for these three subtypes was comparable with or superior to that displayed by the standard drug prazosin. The most-common selectivity rank order was alpha1D > alpha1B > alpha1A, followed by alpha1B > alpha1D > alpha1A. In functional experiments, antagonism towards the alpha2-adrenoreceptor was generally low; however, a few compounds were endowed with significant antagonist properties (pA2 values of up to 7.87). 相似文献
77.
Here we compare gene orders on the Silene latifolia sex chromosomes. On the basis of the deletion mapping results (11 markers and 23 independent Y chromosome deletion lines used), we conclude that a part of the Y chromosome (covering a region corresponding to at least 23.9 cM on the X chromosome) has been inverted. The gradient in silent-site divergence suggests that this inversion took place after the recombination arrest in this region. Because recombination arrest events followed by Y chromosome rearrangements also have been found in the human Y chromosome, this process seems to be a general evolutionary pathway. 相似文献
78.
The Catalytic Mechanism of Nucleoside Diphosphate Kinases 总被引:8,自引:0,他引:8
Nucleoside diphosphate kinases catalyze the reversible transfer of the phosphate of nucleosidetriphosphates to nucleoside diphosphates. This minireview presents recent advances inunderstanding the reaction mechanism using steady-state and fast kinetic studies, X-raycrystallography, and site-directed mutagenesis. We also briefly discuss the physiological relevance ofin vitro studies. 相似文献
79.
80.
Petrisor IG Dobrota S Komnitsas K Lazar I Kuperberg JM Serban M 《International journal of phytoremediation》2004,6(1):1-15
Intensive mining and processing activities worldwide resulted in the generation of huge amounts of waste (tailings), generally characterized as toxic, radioactive, and/or hazardous. The exposure potential and, hence, the risk posed by such wastes is enhanced by a general lack of vegetation. Phytostabilization has proven to be efficient in reducing this risk. However, establishing vegetation on tailing dumps may be expensive due to the intensive use of amendments and chemical fertilizers. In this article, investigations on artificial inoculation of mine tailings with bacterial strains as a means to improve the development of vegetative covers and reduce application cost by eliminating chemical fertilization are presented and discussed. The development of plants and microbial communities from tailings, as well as the impact of inoculation on metal uptake in plants, were studied. Experiments were carried out in greenhouse using two types of mine tailings (phosphogypsum and sulphidic tailings) from the Romanian Black Sea coast. Indigenous herbaceous plants were cultivated on tailings with the addition of chemical fertilizers versus bacterial inoculation. After a 6-month experimental period, excellent plant growth, which is associated with a rich microbial community, was observed in all inoculated treatments, in contrast with poor plant growth and microbiota from the chemical fertilization treatments alone. Additionally, artificial inoculation improved plant resistance to heavy metals by reducing the uptake of some toxic metals. Once a rich microbial community is established, inoculation may be discontinued. Based on these results, efficient and cost-effective phytostabilization schemes can be proposed. 相似文献