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1.
Metabolites of corticosteroids that contain the 21-oic acid moiety are found in human urine. The acids from neutral steroids and urinary pigments have been separated by passing the mixture through a column of polyethyleneimine cellulose. The acids adhering to the column are quantitatively eluted with dilute formic acid. The purified preparation is suitable for derivatization and chromatographic analysis. 相似文献
2.
Mercedes González-Wangüemert Francisca Giménez-Casalduero Ángel Pérez-Ruzafa 《Biochemical Systematics and Ecology》2006
Genetic variation at 10 enzyme loci was analysed in Elysia timida sacoglossan mollusc samples, originating from both coastal lagoon and marine sites. The observed heterozygosity ranged from 0.390 (Los Urrutias) to 0.277 (Tabarca). Marine and coastal lagoon populations were characterised by exclusive alleles. 相似文献
3.
The population ecology of the beetle Speonomus hydrophilus , occurring both in caves (reduced fluctuations in many abiotic parameters) and under the deepest layer of soil in mountains (MSS, more exposed to climatic variations), was studied in four habitats in the French central Pyrenees We have assessed some of the characteristics of the environment where these populations occur c g physical data (altitude and exposure), geologic data (nature of the parent-rock) and abiotic parameters (temperature with its seasonal fluctuations) and we investigated the relative importance of environmental structure and ecological characteristics on the temporal organization of S hydrophilus and the troglobitic fauna which cohabits The climatic study shows the existence of an annual thermal cycle which is regular and well marked for the MSS habitats but slightly out of phase with the surface cycle These periodic variations however slight may be stressful for troglobitic species In the MSS populations, the phenology of the entire community is reflected in the pattern seen in Speonomus The analysis of faunal profiles shows that samples follow the same seasonal succession during the annual cycle A potential seasonal rhythm of emergence may reflect a seasonal rhythm of vitellogenesis which produces a rhythm of egg-laying 相似文献
4.
A procedure for enzymatic production of dihydroneopterin triphosphate is described that allows GTP cyclohydrolase I to be reused repetitively. The reaction takes place in an ultrafiltration cell, and the product is collected in the filtrate, whereas the enzyme remains in the cell to be reused with additional substrate. This is repeated until the enzyme activity drops below a desirable level. The purity of the dihydroneopterin triphosphate is satisfactory for utilization of this compound for studies on enzymes involved in the synthesis of tetrahydrobiopterin and drosopterin. A procedure for purification of dihydroneopterin triphosphate is described that uses C18-silica and silica cartridges. 相似文献
5.
Maria Jesús García Rosario Brieva Francisca Rebolledo Vicente Gotor 《Biotechnology letters》1991,13(12):867-870
Summary 2,2,2-Trifluoroethyl -chloro--phenylacetate is succesfully hydrolysed in organic solvent in the presence of aniline andCandida cylindracea orPseudomonas cepacia lipase as catalysts. 相似文献
6.
A geometrical model of the emergence of a primordium at the shoot apex in dicotyledons is proposed. It is based on recent fundamental results on plant morphogenesis, i.e.:
- the emergence is preceded by the reorganization of the microtubules of the cortical cytoskeleton, leading to a new orientation of the synthesis of the cell wall microfibrils;
- the resulting global stress is related to the general orientation of the cell growth.
- Why does the principal stem shift its growth direction after each lateral emergence?
- Why do the three axes involved in any ramification (namely the old and the new principal stems and the lateral emergence) exhibit a plane configuration whereas this is an essentially three dimensional phenomenon?
- Does phyllotaxis exclusively depend upon the local emergence of a primordium?
7.
Roberto de la Herrán Miguel Hermida Juan Andres Rubiolo Jèssica Gómez-Garrido Fernando Cruz Francisca Robles Rafael Navajas-Pérez Andres Blanco Paula Rodriguez Villamayor Dorinda Torres Pablo Sánchez-Quinteiro Daniel Ramirez Maria Esther Rodríguez Alberto Arias-Pérez Ismael Cross Neil Duncan Teresa Martínez-Peña Ana Riaza Adrian Millán M. Cristina De Rosa Davide Pirolli Marta Gut Carmen Bouza Diego Robledo Laureana Rebordinos Tyler Alioto Carmelo Ruíz-Rejón Paulino Martínez 《Molecular ecology resources》2023,23(4):886-904
Sex determination (SD) shows huge variation among fish and a high evolutionary rate, as illustrated by the Pleuronectiformes (flatfishes). This order is characterized by its adaptation to demersal life, compact genomes and diversity of SD mechanisms. Here, we assembled the Solea senegalensis genome, a flatfish of great commercial value, into 82 contigs (614 Mb) combining long- and short-read sequencing, which were next scaffolded using a highly dense genetic map (28,838 markers, 21 linkage groups), representing 98.9% of the assembly. Further, we established the correspondence between the assembly and the 21 chromosomes by using BAC-FISH. Whole genome resequencing of six males and six females enabled the identification of 41 single nucleotide polymorphism variants in the follicle stimulating hormone receptor (fshr) consistent with an XX/XY SD system. The observed sex association was validated in a broader independent sample, providing a novel molecular sexing tool. The fshr gene displayed differential expression between male and female gonads from 86 days post-fertilization, when the gonad is still an undifferentiated primordium, concomitant with the activation of amh and cyp19a1a, testis and ovary marker genes, respectively, in males and females. The Y-linked fshr allele, which included 24 nonsynonymous variants and showed a highly divergent 3D protein structure, was overexpressed in males compared to the X-linked allele at all stages of gonadal differentiation. We hypothesize a mechanism hampering the action of the follicle stimulating hormone driving the undifferentiated gonad toward testis. 相似文献
8.
Angel García-Gutiérrez Francisco R. Cantón Fernando Gallardo Francisca Sánchez-Jiménez Francisco M. Cánovas 《Plant molecular biology》1995,27(1):115-128
Pine seedlings are able to accumulate chlorophylls and develop green plastids in a light-independent manner. In this work, we have characterized ferredoxin-dependent glutamate synthase (EC 1.4.7.1; Fd-GOGAT), a key enzyme in nitrogen interconversion during this process. Fd-GOGAT has been purified about 170-fold from cotyledons of maritime pine (Pinus pinaster). As occurs in angiosperms, the native enzyme is a single polypeptide with an apparent molecular mass of 163–168 kDa that is confined to the chloroplast stroma. Polyclonal antibodies generated against the purified enzyme were used to immunoscreen a gt11 expression library from Scots pine (Pinus sylvestris) seedlings and partial cDNA clones were isolated and characterized. The clone with the longest cDNA insert (pGOP44) contained the codification for the C-terminal (550 amino acids) of the pine Fd-GOGAT polypeptide. Immunological cross-reactivity and comparative amino sequence analysis revealed that Fd-GOGAT is a well conserved protein in higher plants. Western blot analyses showed that protein was expressed in chloroplast-containing pine tissues and this expression pattern was not affected by exogenously supplied nitrogen. Fd-GOGAT mRNA, polypeptide and enzyme activity accumulated in substantial amounts in dark-grown pine seedlings. The presence of a functional Fd-GOGAT may be important to provide the required glutamate for the biosynthesis of nitrogen compounds during chloroplast biogenesis in the dark. 相似文献
9.
Consuelo Díaz de la Guardia Roberto Alonso Francisca Alba Francisco Valle 《Aerobiologia》1995,11(1):47-50
We have carried out a study on the annual and daily pollen concentrations from Gramineae over four consecutive years in the atmosphere of Granada (Spain). Samples of pollen grains were collected by the volumetric method with the aid of a Burkard sporetrap. Gramineae, according both to their high sensitizing capacity and to data from allergologists, are responsible for many pollinoses diagnosed in this area. In this work, daily pollen levels from April to July are monitored and the variations identified are interpreted in relation to meteorological conditions. Results indicated that the highest airborne concentrations of Gramineae pollen were found in May and June, although the beginning and intensity of pollination have been variable during these 4 years. 相似文献
10.
Isabel Haro Rosa M. Pinto Juan F. Gonzalez-Dankaart Jose A. Perez Francisca Reig Albert Bosch 《Microbiology and immunology》1995,39(7):485-490
Peptide VP1 (11-25) of the capsid of hepatitis A virus was synthesized by the Fmoc-polyamide solid phase method, and administered to mice in different forms: (1) free, (2) encapsulated in multilamellar liposomes, (3) coupled to keyhole limpet hemocyanin (KHL), and (4) incorporated into a tetrameric branched lysine core. The highest anti-VP1 peptide responses were generated by synthetic peptides entrapped into liposomes and coupled to KLH. No anti-HAV response was generated with the free peptide, while all the other forms induced both anti-HAV and HAV-neutralizing antibodies. Maximum neutralization indices were observed in ascites from mice treated with liposome-entrapped and KLH peptides. 相似文献