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991.
Baños CE Silva M 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2011,879(17-18):1412-1418
A rapid clean-up method using ultra-filtration was developed to remove sample matrix in the determination of low-molecular mass aldehydes in human urine. The ensuing filtrate was derivatized with fluorescein 5-thiosemicarbazide and the labelled aldehydes determined by capillary zone electrophoresis with laser-induced fluorescence detection. Practical aspects related to the effect of the urine sample matrix on the label chemistry and the electrophoretic separation showed that the urine samples must be diluted 20-fold after their ultra-filtration. By using synthetic urine, linear ranges were established in the range of 15-5000 μg/l with limits of detection between 4.5 and 9 μg/l. The intra- and inter-assay precision (relative standard deviation, %) of the aldehydes ranged from 4.1% to 8.4% and 6.1%-9.6%, respectively, and the average specific uncertainty was 149±12 ng. The average recoveries performed on two levels by enriching synthetic urine samples ranged between 94% and 100%. Finally, the proposed method was applied to check low-molecular mass aldehydes in the human urine of a female volunteer to obtain information about the risk in her exposure to these chemicals in the workplace. 相似文献
992.
Rodríguez-Bonilla P López-Nicolás JM Méndez-Cazorla L García-Carmona F 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2011,879(15-16):1091-1097
In this work, a reversed phase high performance liquid chromatography (RP-HPLC) method was developed for the determination of pterostilbene in food samples. The novel method is based on the addition of cyclodextrins (CDs) to the mobile phase where the complexation of pterostilbene by CDs is carried out. In order to select the most suitable conditions for the RP-HPLC method, the effect of several physico-chemical parameters on the complexation of pterostilbene by CDs was studied. Our results show that the addition of 12 mM HP-β-CD to a 50:50 (v/v) methanol:water mobile phase at 25°C and pH 7.0 significantly improves the main analytical parameters. In addition, it was seen that pterostilbene forms a 1:1 complex with HP-β-CD, showing an apparent complexation constant of 251±13 M(-1). Finally, in order to study the validity of the proposed method, blueberries were analyzed and the concentration of pterostilbene has been determined. 相似文献
993.
994.
Galofré JC Gómez-Sáez JM álvarez Escola C álvarez García E Anda Api?aniz E Calleja A Donnay S Lucas-Martin A Menéndez Torre E Navarro González E Pereg V Pérez Corral B Santamaría Sandi J Riesco Eizaguirre G Zafón Llopis C;Toma de posición del Grupo de Trabajo de Cáncer de Tiroides de la Sociedad Espa?ola de Endocrinología y Nutrición 《Endocrinología y nutrición》2011,58(8):381-386
995.
Jager M Chiori R Alié A Dayraud C Quéinnec E Manuel M 《Journal of experimental zoology. Part B. Molecular and developmental evolution》2011,(3):171-187
Ctenophores are non-bilaterian animals sharing with cnidarians and bilaterians the presence of sensory receptors, nerve cells, and synapses, absent in placozoans and sponges. Although recent immunofluorescence studies have renewed our knowledge of cnidarian neuro-anatomy, ctenophores have been much less investigated despite their importance to understanding the origin and early evolution of the nervous system. In this study, the neuro-anatomy of the ctenophore Pleurobrachia pileus (Müller, 1776) was explored by whole-mount fluorescent antibody staining using antibodies against tyrosylated -tubulin, FMRFamide, and vasopressin. We describe the morphology of nerve nets and their local specializations, and the organization of the aboral neuro-sensory complex comprising the apical organ and polar fields. Two distinct nerve nets are distinguished: a mesogleal nerve net, loosely organized throughout body mesoglea, and a much more compact “nerve net” with polygonal meshes in the ectodermal epithelium. The latter is organized as a plexus of short nerve cords. This epithelial nervous system contains distinct sub-populations of dispersed FMRFamide and vasopressin immunoreactive nerve cells. In the aboral neuro-sensory complex, our most significant observations include specialized nerve nets underlying the apical organ and polar fields, a tangential bundle of actin-rich fibers (interpreted as a muscle) within the polar fields, and distinct groups of neurons labeled by anti-FMRFamide and anti-vasopressin antibodies, within the apical organ floor. These results are discussed in a comparative perspective. 相似文献
996.
Mariem Bouhadida Mar��a ��ngeles Moreno Mar��a Jos�� Gonzalo Jos�� Manuel Alonso Yolanda Gogorcena 《Tree Genetics & Genomes》2011,7(2):257-270
A set of 94 peach cultivars including Spanish native peach and foreign commercial cultivars were analyzed using 15 SSR markers,
selected for their high level of polymorphism. The number of alleles obtained varied from two to 11 with an average of 6.73
giving 185 different genotypes. All the cultivars showed a unique genetic profile, each one using different genotypic combination
of all loci. BPPCT001 was the most informative locus showing also the highest discrimination power. Only six loci allowed
the unambiguous separation of all the Spanish native cultivars studied, and the genotypic combination of only eight loci permitted
the total differentiation of the 94 peach cultivars analyzed. The six selected loci (BPPCT001, BPPCT006, BPPCT008, PS9f8,
UDP98-022, and UDP98-412) seem to be very useful for future Spanish peach identification works, and they will help to establish
a molecular data base for native peach cultivars. UPGMA analysis was performed from the genetic distance matrix, and allowed
the arrangement of all genotypes according to their genetic diversity. The genetic diversity among cultivars, observed in
this work, led to their separation according to their regional origin, their morphological characteristics, and especially
according to their fruit traits. Analysis of molecular variance was performed for seven populations from different regions
of Spain and USA to examine the distribution of genetic variation of the studied accessions, showing that the major variation
occurred within populations in each geographic site. The results reveal the existence of two diversity regions in Spain for
peach germplasm. 相似文献
997.
Wu H Pomeroy SL Ferreira M Teider N Mariani J Nakayama KI Hatakeyama S Tron VA Saltibus LF Spyracopoulos L Leng RP 《Nature medicine》2011,17(3):347-355
The TP53 gene (encoding the p53 tumor suppressor) is rarely mutated, although frequently inactivated, in medulloblastoma and ependymoma. Recent work in mouse models showed that the loss of p53 accelerated the development of medulloblastoma. The mechanism underlying p53 inactivation in human brain tumors is not completely understood. We show that ubiquitination factor E4B (UBE4B), an E3 and E4 ubiquitin ligase, physically interacts with p53 and Hdm2 (also known as Mdm2 in mice). UBE4B promotes p53 polyubiquitination and degradation and inhibits p53-dependent transactivation and apoptosis. Notably, silencing UBE4B expression impairs xenotransplanted tumor growth in a p53-dependent manner and overexpression of UBE4B correlates with decreased expression of p53 in these tumors. We also show that UBE4B overexpression is often associated with amplification of its gene in human brain tumors. Our data indicate that amplification and overexpression of UBE4B represent previously undescribed molecular mechanisms of inactivation of p53 in brain tumors. 相似文献
998.
999.
Wan L Zou W Gao D Inuzuka H Fukushima H Berg AH Drapp R Shaik S Hu D Lester C Eguren M Malumbres M Glimcher LH Wei W 《Molecular cell》2011,44(5):721-733
The APC/Cdh1 E3 ubiquitin ligase plays an essential role in both mitotic exit and G1/S transition by targeting key cell-cycle regulators for destruction. There is mounting evidence indicating that Cdh1 has other functions in addition to cell-cycle regulation. However, it remains unclear whether these additional functions depend on its E3 ligase activity. Here, we report that Cdh1, but not Cdc20, promotes the E3 ligase activity of Smurf1. This is mediated by disruption of an autoinhibitory Smurf1 homodimer and is independent of APC/Cdh1 E3 ligase activity. As a result, depletion of Cdh1 leads to reduced Smurf1 activity and subsequent activation of multiple downstream targets, including the MEKK2 signaling pathway, inducing osteoblast differentiation. Our studies uncover a cell-cycle-independent function of Cdh1, establishing Cdh1 as an upstream component that governs Smurf1 activity. They further suggest that modulation of Cdh1 is a potential therapeutic option for treatment of osteoporosis. 相似文献
1000.
Nazaret Hidalgo Giulia Mangiameli Teresa Manzano Galina G. Zhadan John F. Kennedy Valery L. Shnyrov Manuel G. Roig 《Biotechnology and Bioprocess Engineering》2011,16(4):821-829
The degradation and removal of a series of dyes used in the textile industry for polyester/wool (PES/WO) blends and present
in effluents, such as Green, Ash-Grey, Black, Navy Blue, Red and Yellow Domalan, and Orange and Red Bemacid, by catalytic
action, in the presence of H2O2, of extracts of a novel peroxidase from postharvest lentil stubble was investigated. The extracts of this peroxidase (LSP)
were effective in degrading these lastgeneration textile dyes, especially Green Domalan, Orange Bemacid, Grey and Black Domalan.
A sensitivity study was carried out for Green Domalan biodegradation to determine the effects of process parameters such as
pH, H2O2, enzyme and dye concentrations, contact and centrifugation times, and temperature. Standard ecotoxicity studies performed
with Vibrio fischeri revealed that the dye solutions treated with peroxidase and H2O2 were less ecotoxic than the untreated ones. 相似文献