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Stylianos Tzeis Sokratis Pastromas George Andrikopoulos 《Indian pacing and electrophysiology journal》2013,13(6):231-234
In the present case, we describe the abrupt transformation of intra-pulmonary vein activity from rapid firing to dissociated ectopic activity during sinus rhythm, as an easily identifiable, though rare to encounter, sign which documents the achievement of bidirectional block. 相似文献
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Julio Bohrquez Danielle Calenti Emilio García‐Robledo Sokratis Papaspyrou Juan Luis Jimenez‐Arias Eddy Humberto Gmez‐Ramírez Alfonso Corzo 《Journal of phycology》2019,55(3):625-636
Primary production of microphytobenthos (MPB) contributes significantly to the total production in shallow coastal environments. MPB is a diverse community in which diatoms are usually the main microalgal group. Diatoms require N, P, and other nutrients as with other autotrophs, but in addition require silicate to create their outer cell wall. Therefore, dissolved silica (DSi) might be a potential limiting factor for benthic primary production in areas with reduced freshwater input. To test this hypothesis, a microcosm experiment was conducted using intact sediment cores collected from an intertidal mudflat in the Bay of Cádiz and supplied with increasing concentrations of DSi (0, 5, 10, 25, and 45 μmol · L?1). After 7 d of enrichment, we determined chlorophyll a and c (Chl a, c) contents, metabolic rates (Net [Pn] and Areal Gross [PgA] Production and Light [RL] and Dark [RD] Respiration), as well as fluxes of inorganic nutrients across the sediment‐water interface. Chl a and c contents increased significantly with respect to the initial conditions but no differences between treatments were found. Both Pn and PgA showed a saturating‐like pattern with silicate concentration, reaching maximum rates at a DSi concentration of 45 μmol · L?1. The addition of DSi also resulted in an increase of DSi and ammonium uptake by the sediment, which was significantly higher in light than in darkness. Our results clearly show that water column DSi concentrations have a direct impact on benthic primary production, also controlling other related processes such as inorganic nutrient fluxes. 相似文献
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We have characterized the dopamine D2 receptor photoaffinity probe, [3H]azido-N-methylspiperone ([3H]AMS). In the absence of light, [3H]AMS bound reversibly and with high affinity (Kd 70 pM) to sites in canine striatal membranes and was competitively inhibited by dopaminergic agonists and antagonists with an appropriate D2 receptor specificity. Upon photolysis, [3H]AMS covalently incorporated into a peptide of Mr 92,000 as assessed by fluorography following SDS-polyacrylamide gel electrophoresis. Labelling of this peptide was specifically and stereoselectively blocked by D2 antagonists and agonists. Minor specifically labelled peptides of Mr 70,000-55,000 were observed under some conditions and were the result of proteolytic degradation of the peptide at Mr 92,000. 相似文献
85.
The clonal multipotential RCJ 3.1 cell line, which gives rise to myotubes, adipocytes, chondrocytes, and osteoblasts, contains different progenitor subpopulations. By limiting dilution analysis, of 296 single colonies identified, approximately 20% contained a single recognizable cell type, approximately 10% contained two cell types, and approximately 1% contained three cell types. We recloned RCJ 3.1 and isolated continuously growing subclones, including four novel bipotential (adipocytes/chondrocytes; adipocytes/myotubes and chondrocytes/myotubes) cell populations, whose phenotypes bred true. In the bipotential subclones, single colony analyses confirmed the presence of single cells which could both self-renew the bipotential progenitors and give rise to their respective committed monopotential lineages. Eight subclones were restricted to a single cell lineage and were considered monopotential; one of these is a novel cell line differentiating into cartilage. Thus, we have isolated unique monopotential and bipotential progenitor cell lines which provide a valuable model for studying the mechanisms leading to lineage restriction in mesenchymal populations. 相似文献
86.
D Bauer A Locker P Grigoriadis H G Goslar K H Jaeger 《Biochemistry and experimental biology》1979,15(2):147-153
The lethal irradiation with gamma-rays (LD 100/30) of adult mice at ambient temperature of 32.5 degrees C heavily alterates the pattern of LDH in liver. In close correspondence with the radioprotective effect of Solcoseryl on the survival rate of irradiated mice -- which amounts to 100% as compared with 40% survival of solely heat adapted animals -- Solcoseryl normalizes the LDH distribution both histochemically and biochemically. Since Solcoseryl alone generally enhances enzyme activity the normalization observed is obviously attributable to an intrinsically regulatory property of this natural compound. 相似文献
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