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21.
The topography of the Sado estuary, the second largest of Portugal, comprises the outer estuary inside the entrance channel
and the inner estuary, on the inward side of which begins the tidal mudflats. The outer estuary subtidal area covers approximately
70 km2 and presents a series of longitudinal intertidal sandbanks, separating a northern and a southern channel.
A benthic survey was undertaken in the outer estuary during June 1986, in which superficial sediments and macrofauna were
sampled at 133 locations. The environmental variables measured in the superficial sediments were the temperature, the granulometric
structure, the silt, sand and the gravel content, and the total organic matter content. The primary macrofauna biological
variables studied were the species composition, abundance and biomass, calculated on wet, dry and ash-free dry weight.
The granulometry and the organic content of superficial sediments agreed with the transient and the residual currents velocity
field, simulated in a 2-D hydrodynamic model previously elaborated for the outer estuary. The northern channel superficial
sediments showed higher silt and total organic matter content, while the model also suggested lower transient and residual
velocities, water flow and shear stress in this channel.
The distribution patterns of the subtidal macrofauna were separated into two main groups of species, one comprising taxa essentially
settled near the estuarine mouth and the other inwards. Biological primary variables also showed consistent patterns, comparable
to other Portuguese estuaries. The major subtidal benthic biotopes were obtained through classification analysis and related
to the prevailing hydrophysical and sedimentary conditions in the outer estuary. 相似文献
22.
Marta Clariano Vanda Marques João Vaz Salma Awam Marta B. Afonso Maria Jesus Perry Cecília MP Rodrigues 《化学与生物多样性》2023,20(3):e202300222
Curcumin has a plethora of biological properties, making this compound potentially effective in the treatment of several diseases, including cancer. However, curcumin clinical use is compromised by its poor pharmacokinetics, being crucial to find novel analogs with better pharmacokinetic and pharmacological properties. Here, we aimed to evaluate the stability, bioavailability and pharmacokinetic profiles of monocarbonyl analogs of curcumin. A small library of monocarbonyl analogs of curcumin 1a–q was synthesized. Lipophilicity and stability in physiological conditions were both assessed by HPLC-UV, while two different methods assessed the electrophilic character of each compound monitored by NMR and by UV-spectroscopy. The potential therapeutic effect of the analogs 1a–q was evaluated in human colon carcinoma cells and toxicity in immortalized hepatocytes. Our results showed that the curcumin analog 1e is a promising agent against colorectal cancer, with improved stability and efficacy/safety profile. 相似文献
23.
Rafael Fogaça de Almeida Aline Castro Rodrigues Lucena Michel Batista Fabricio Klerynton Marchini Lyris Martins Franco de Godoy 《Proteomics》2023,23(16):2200230
Post-translational methylation of proteins, which occurs in arginines and lysines, modulates several biological processes at different levels of cell signaling. Recently, methylation has been demonstrated in the regulation beyond histones, for example, in the dynamics of protein-protein and protein-nucleic acid interactions. However, the presence and role of non-histone methylation in Trypanosoma cruzi, the etiologic agent of Chagas disease, has not yet been elucidated. Here, we applied mass spectrometry-based-proteomics (LC-MS/MS) to profile the methylproteome of T. cruzi epimastigotes, describing a total of 1252 methyl sites in 824 proteins. Functional enrichment and protein-protein interaction analysis show that protein methylation impacts important biological processes of the parasite, such as translation, RNA and DNA binding, amino acid, and carbohydrate metabolism. In addition, 171 of the methylated proteins were previously reported to bear phosphorylation sites in T. cruzi, including flagellar proteins and RNA binding proteins, indicating that there may be an interplay between these different modifications in non-histone proteins. Our results show that a broad spectrum of functions is affected by methylation in T. cruzi, indicating its potential to impact important processes in the biology of the parasite and other trypanosomes. 相似文献
24.
Brittonia - Two new species ofCompsoneura (Myristicaceae) from recent collections are described, discussed, and illustrated:Compsoneura rigidifolia, a species from the wet forest along the... 相似文献
25.
26.
Rodrigues C.R. Barreiro E.J. Romeiro N.C. Albuquerque M.G. De Sant'anna C.M.R. Bicca De Alencastro R. Da Motta Neto J.D. 《Molecular Engineering》1997,7(3-4):473-490
Two families of autacoids from cell membrane phospholipids have been identified. The first, the icosanoids, which are formed
from arachidonic acid, include prostaglandins and leukotrienes. The other includes modified phospholipids, as the platelet
aggregating factor (PAF). These compounds are related to inflammatory and cardiovascular diseases.
We review in this paper some of the work that has been done in our laboratories in the last few years relating to the modeling
of new potential thromboxane synthase (TXS) and 5-lipoxygenase (5-LO) and cyclooxygenase (COX) inhibitors, and TXA2 receptor antagonists derived from nitrogenated heterocycles. We include the results of the modeling of a group of proposed
PAF antagonists, and compare their structures with PAF itself and with a recently proposed PAF antagonist model.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
27.
The phytoplankton community of Lake Camaleão, a smallfloodplainlake influenced by a large whitewater river, the Solimões, was monthlyinvestigated for the composition and abundance of itsphytoplankton. The seasonal influence of the floodregime on biomass, species richness and diversity, andits relation with physical and chemical factors(temperature, pH, dissolved oxygen, electricalconductivity, total seston and inorganic nutrients)was analyzed and subjected to principal componentanalysis. Diversity was variable along the seasonalcycle: relatively high values were observed at the endof the dry season supported by high nutrientconcentrations. The phytoplankton was comprised of 262 taxa,with strong dominanceof euglenoids (81%). The three sample stations did not differamong each other, except in the dry season, due todata cluster in relation to theprincipal axis (1 and 2), explaining 63% of thevariation. Biomass accumulation as a function of lakearea reduction contributed to theseresults, indicating that the phytoplankton dynamicswere hydrology-driven. 相似文献
28.
T. Macedo C. A. Fontes Ribeiro D. Cotrim P. Tavares M. T. Morgadinho M. Caramona M. T. Nunes Vicente L. Rodrigues M. G. Cardoso M. L. Keating 《Molecular neurobiology》1995,11(1-3):21-29
This work evaluated in a population of heroin and heroin plus cocaine human addicts:
- Norepinephrine (NE), epinephrine (Epi), and 3-methoxy-4-hydroxyphenylglycol (MHPG) (the principal metabolite of brain NE) plasma levels;
- Monoamine oxidase (MAO) activity; and
- 3H-imipramine specific binding to the amine carrier in platelets.
29.
R A Prysor-Jones J J Silverlight J S Jenkins A N Stevens J L Rodrigues J R Griffiths 《FEBS letters》1984,177(1):71-75
Intravenous thyrotrophin releasing hormone (TRH) caused a 6.5-fold increase in plasma prolactin (PRL) in rats carrying implanted pituitary tumours. Vasoactive intestinal polypeptide (VIP) had no effect, but TRH given after VIP raised TRH stimulated secretion 13-fold above basal. 31P NMR spectroscopy showed that VIP caused a decrease in high energy metabolites (depleted phosphocreatine, elevated inorganic phosphate and lowered intracellular pH). TRH alone caused a similar but smaller effect; given after VIP, it caused no detectable depletion. We suggest that the changes in high energy metabolite concentrations reflect increased cellular energy consumption consistent with a priming process (stage 1) in PRL secretion, followed by hormone release (stage 2). VIP induces stage 1 whereas RTH induced both stages. 相似文献
30.