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Neurons in the superficial layers of the superior colliculus are key elements in the visual system of rodents since they receive extensive afferent projections from retinal ganglion cells. The NADPH-diaphorase histochemical technique was used to detect differences in neuronal nitric oxide synthase (nNOS) in the superficial layers of the superior colliculus (sSC) of young adult (3 months) and aged (24 and 26 months) rats. The orientation of the dendritic processes of NADPH-diaphorase-positive neurons, cross-sectional area, and number of neurons per mm2 were analyzed. NADPH-d histochemistry revealed a high number of NADPH-d-positive cells in the stratum zonale and stratum griseum superficiale in adult and aged animals. NADPH-d-positive neurons were classified into the following morphological types: marginal, horizontal, pyriform, narrow-field vertical, wide-field vertical, and stellate. During aging, narrow field vertical and wide field vertical neurons present somatic atrophy and an increase in dendritic processes with dorsoventral orientation, whereas wide field vertical neurons show a decrease in those with lateromedial orientation. Marginal neurons undergo somatic hypertrophy at 26 months when compared with those at 3 months. The remaining types of neurons do not undergo size changes. Finally, the number of NADPH-d-positive neurons per mm2 in the various types of morphology does not significantly change with age. It is suggested to be likely that the aging process in the nitrergic neurons of the sSC does not lead to significant changes in the synthesis of NO from the constitutive NOS isoforms. 相似文献
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Monica Patrascu Alexandra Florentina Stancu Florin Pop 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2014,18(12):2565-2576
Today, there is a substantial need for population evolution modeling in multidisciplinary research areas, such as social sciences (sociology, anthropology etc.), which can neither be solved formally, nor empirically at global scale, thus requiring the development of heuristic techniques, like evolutionary algorithms. Therefore, existent methodologies of social simulation can be extended from microenvironments to large scale modeling of extremely complex systems, as it is the case of human evolution. The modeling of population evolution prediction is currently used in high interest areas, from migration flows, to financial crisis simulation, to the free-market economy models, as well as multi-national family dynamics and cultural aspects. The high performance of evolutionary computing has been already proven in the context of virus population evolution, be they biological or cybernetic, thus making them the perfect method for our endeavour. This paper presents the design and implementation of a soft computing application, namely HELGA—heterogeneous encoding lifelike genetic algorithm. HELGA was designed for the modeling and simulation of Earth population evolution, on a global scale, throughout multiple historical eras. The model shows the tendency of human evolution towards one mixed race. The algorithm takes into account the influence of social factors, such as the Industrial Revolution or the discovery of the New World. Our method, for which all constraints have been based on validated research, has aligned precisely to real historical events: it anticipated the end of antiquity, the industrial era, the baby boom phenomenon and so on. For example, the poor health conditions of the Middle Ages have caused a drastic drop in population size. The presented model shows the valiant result of one final race, and although this theory cannot be formally proved in the present, we consider that our results can be used as hypothesis for future social science research. Also, HELGA can be extended with new capabilities and constraints. 相似文献
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Florentina Tone 《Journal of scientific computing》2009,38(3):331-348
Pursuing our work in Tone (Asymptot. Analysis 51:231–245, 2007) and Tone and Wirosoetisno (SIAM J. Number. Analysis 44:29–40, 2006), we consider in this article the two-dimensional magnetohydrodynamics equations, we discretize these equations in time using
the implicit Euler scheme and with the aid of the classical and uniform discrete Gronwall lemma, we prove that the scheme
is H
2-uniformly stable in time. 相似文献
45.
The influence of contrasting suspended particulate matter transport regimes on the bias and precision of flux estimates 总被引:2,自引:0,他引:2
Moatar F Person G Meybeck M Coynel A Etcheber H Crouzet P 《The Science of the total environment》2006,370(2-3):515-531
A large database (507 station-years) of daily suspended particulate matter (SPM) concentration and discharge data from 36 stations on river basins ranging from 600 km(2) to 600,000 km(2) in size (USA and Europe) was collected to assess the effects of SPM transport regime on bias and imprecision of flux estimates when using infrequent surveys and the discharge-weighted mean concentration method. By extracting individual SPM concentrations and corresponding discharge values from the database, sampling frequencies from 12 to 200 per year were simulated using Monte Carlo techniques. The resulting estimates of yearly SPM fluxes were compared to reference fluxes derived from the complete database. For each station and given frequency, bias was measured by the median of relative errors between estimated and reference fluxes, and imprecision by the difference between the upper and lower deciles of relative errors. Results show that the SPM transport regime of rivers affects the bias and imprecision of fluxes estimated by the discharge-weighted mean concentration method for given sampling frequencies (e.g. weekly, bimonthly, monthly). The percentage of annual SPM flux discharged in 2% of time (Ms(2)) is a robust indicator of SPM transport regime directly related to bias and imprecision. These errors are linked to the Ms(2) indicator for various sampling frequencies within a specific nomograph. For instance, based on a deviation of simulated flux estimates from reference fluxes lower than +/-20% and a bias lower than 1% or 2%, the required sampling intervals are less than 3 days for rivers with Ms(2) greater than 40% (basin size<10,000 km(2)), between 3 and 5 days for rivers with Ms(2) between 30 and 40% (basin size between 10,000 and 50,000 km(2)), between 5 and 12 days for Ms(2) from 20% to 30% (basin size between 50,000 and 200,000 km(2)), 12-20 days for Ms(2) in the 15-20% range (basin size between 200,000 and 500,000 km(2)). 相似文献
46.
Dantigny P Guilmart A Radoi F Bensoussan M Zwietering M 《International journal of food microbiology》2005,98(3):261-269
The effect of ethanol (E) on the radial growth rate (mu) of food spoilage moulds (Aspergillus candidus, Aspergillus flavus, Aspergillus niger, Cladosporium cladosporioides, Eurotium herbariorum, Mucor circinelloides, Mucor racemosus, Paecilomyces variotii, Penicillium chrysogenum, Penicillium digitatum, Rhizopus oryzae and Trichoderma harzianum) was assessed in Potato Dextrose Agar (PDA) medium at a(w) 0.99, 25 degrees C. In order to model this effect, the Monod type equation described previously by Houtsma et al. (Houtsma, P.C., Kusters, B.J.M., de Wit, J.C., Rombouts, F.M., Zwietering, M.H., 1994. Modelling growth rates of Listeria monocytogenes as a function of lactate concentration. Int. J. Food. Microbiol. 24, 113-123.) was re-parameterised: mu = mu(opt)[K(E(max)-E)/K E(max)-2KE+E(max)E]; E(max) (%, wt/wt): ethanol concentration at which no growth occurs, K (%, wt/wt): ethanol concentration at which mu = mu(opt)/2, mu(opt) (mm day(-1)): growth rate at 0% ethanol. The model was capable of describing curves, mu vs. E, with either a concave shape (KE(max)/2) with a good accuracy (root mean square error (RMSE) < or = 0.136) with the notable exception of R. oryzae and T. harzianum. After growth rate data were square-root transformed to stabilise the variance, E(max) was estimated in the range 3% to 5% for all moulds with the exception of T. harzianum (E(max) 2.14%) and P. variotii (E(max) 6.43%). Ethanol would appear an effective additional barrier to inhibit fungal growth in food products and would represent an interesting alternative to the use of preservatives. 相似文献
47.
Díaz F Moreno P Villena A Vidal L Pérez De Vargas I 《Microscopy research and technique》2003,62(5):431-438
The aim of this study was to investigate the effect of aging on glial cells and neurons from the superficial layers of the superior colliculus in rats. We used stereological methods to estimate the volume of the superficial layers, neuron size, and the number of neurons and glial cells in Wistar male rats aged 3, 24, 26, and 28 months. A 32.6% volume increase was found in the stratum griseum superficiale between the ages of 3 and 26 months, while in the 28-month-old animals a 19% decrease was observed. The stratum opticum did not show any changes in volume with age. Also, our analysis revealed a process of somatic and nuclear atrophy in the neurons of the superficial layers in animals aged 26 and 28 months. On the other hand, no statistically significant differences were found in the numbers of neurons. The number of glial cells in the stratum griseum superficiale showed an increase between the 3rd and 26th month, while the stratum opticum suffered no change. 相似文献
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Carmen Elena Condrat Valentin Nicolae Varlas Florentina Duic Panagiotis Antoniadis Cezara Alina Danila Dragos Cretoiu Nicolae Suciu Sanda Maria Creoiu Silviu Cristian Voinea 《International journal of molecular sciences》2021,22(8)
Extracellular vesicles (EVs) are small vesicles ranging from 20–200 nm to 10 μm in diameter that are discharged and taken in by many different types of cells. Depending on the nature and quantity of their content—which generally includes proteins, lipids as well as microRNAs (miRNAs), messenger-RNA (mRNA), and DNA—these particles can bring about functional modifications in the receiving cells. During pregnancy, placenta and/or fetal-derived EVs have recently been isolated, eliciting interest in discovering their clinical significance. To date, various studies have associated variations in the circulating levels of maternal and fetal EVs and their contents, with complications including gestational diabetes and preeclampsia, ultimately leading to adverse pregnancy outcomes. Furthermore, EVs have also been identified as messengers and important players in viral infections during pregnancy, as well as in various congenital malformations. Their presence can be detected in the maternal blood from the first trimester and their level increases towards term, thus acting as liquid biopsies that give invaluable insight into the status of the feto-placental unit. However, their exact roles in the metabolic and vascular adaptations associated with physiological and pathological pregnancy is still under investigation. Analyzing peer-reviewed journal articles available in online databases, the purpose of this review is to synthesize current knowledge regarding the utility of quantification of pregnancy related EVs in general and placental EVs in particular as non-invasive evidence of placental dysfunction and adverse pregnancy outcomes, and to develop the current understanding of these particles and their applicability in clinical practice. 相似文献
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Investigations of obtaining BiSb, BiTe, SbTe and BiSbTe films in concentrated chloride aqueous solution (5 M NaCl + 1 M HCl) or in ionic liquid based on choline chloride + malonic acid mixture were reported. The concentrations of Bi, Sb, Te, existing as complex anions due to high Cl− concentration, were within 10–90 mM. The measurements were carried out at room temperature for aqueous medium and 85 °C for ionic liquid. Cyclic voltammetry and electrochemical impedance spectroscopy using Pt electrode were used for investigating the interface process in both electrolytes. The morphology and chemical composition of films deposited on Cu in chloride aqueous solution using current pulses or potential pulses were determined by AFM and SEM microscopy. For BiSb, the effects of change from unipolar to reverse pulses and increase in cathodic current were shown as favorable. SEM images for BiSbTe confirmed the morphology modification by increasing the current pulses, while energy dispersive spectroscopy analyses indicate a dramatic change of composition. 相似文献
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Alina Florentina Vladu Denisa Ficai Alexandra Gabriela Ene Anton Ficai 《International journal of molecular sciences》2022,23(18)
Polyphenols represent a structural class of mainly natural organic chemicals that contain multiple phenol structural units. The beneficial properties of polyphenols have been extensively studied for their antitumor, anti-inflammatory, and antibacterial effects, but nowadays, their medical applications are starting to be extended to many other applications due to their prebiotic role and their impact on the microbiota. This review focused on the use of polyphenols in cancer treatment. Their antineoplastic effects have been demonstrated in various studies when they were tested on numerous cancer lines and some in in vivo models. A431 and SCC13 human skin cancer cell lines treated with EGCG presented a reduced cell viability and enhanced cell death due to the inactivation of β-catenin signaling. Additionally, resveratrol showed a great potential against breast cancer mainly due to its ability to exert both anti-estrogenic and estrogenic effects (based on the concentration) and because it has a high affinity for estrogen receptors ERα and Erβ. Polyphenols can be combined with different classical cytostatic agents to enhance their therapeutic effects on cancer cells and to also protect healthy cells from the aggressiveness of antitumor drugs due to their anti-inflammatory properties. For instance, curcumin has been reported to reduce the gastrointestinal toxicity associated with chemotherapy. In the case of 5-FU-induced, it reduced the gastrointestinal toxicity by increasing the intestinal permeability and inhibiting mucosal damage. Co-administration of EGCG and doxorubicin induced the death of liver cancer cells. EGCG has the ability to inhibit autophagic activity and stop hepatoma Hep3B cell proliferation This symbiotic approach is well-known in medical practice including in multiple chemotherapy. 相似文献