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The aim of this study was to determine the link between the elements of a riverbed system (river length, longitudinal profile, bottom width, river bed depth, bank slope, bank protection, bottom substrate, and level of silt build-up), modified by regulatory and maintenance work, the number of aquatic vascular plant species, and their evenness present in both small and medium lowland streams in Poland. 100 study sections were analysed in 29 watercourses. Due to their geological, hydromorphological, and climate settings, the examined watercourses are representative of the central European plains, of which 65 sections are located in regulated and maintained watercourses and 35 are in unmodified streams. The Shapley value regression method was used to establish the influence of the stream features on aquatic plants. Results identified 27 different macrophyte taxa, where the most frequently occurring were Sparganium emersum Rehmann, Phalaris arundinacea L., and Lemna minor L. The results found that aquatic plant communities were influenced by the analysed factors, regardless of whether a watercourse was shaped by technical means or not. The most influential parameters were the level of silt build-up and bottom width. Furthermore, results brought to evidence that watercourses are complex systems where elements are linked by a series of relationships and that single correlations among environmental elements, anthropogenic interactions, and aquatic plants are very rare.
Schizophrenia manifests itself primarily with positive symptoms, negative symptoms and cognitive disorders. Animal models of mental diseases seem to be an important tool in understanding key theories related with pathophysiology of the disorder and are used to assess efficacy of new drugs. References describe four basic groups of animal models of schizophrenia, such as: models created by pharmacological intervention, genetic models, lesion models and models of developmental disorders of primary brain structures. Of the models referred to above, the group of developmental disorder models is particularly noteworthy, as they are primarily easy to use, and the methods are highly sensitive. High scientific value of these models is associated with the neurodevelopmental theory which stipulates that at an early stage of body development, a number of interactions between genetic and environmental factors may affect the development of neurons which may cause disorders of brain cytoarchitecture development.We review six developmental models of schizophrenia in rats (MAM - methylooxymethanol acetate, prenatal stress, maternal deprivation, isolation rearing, prenatal immune challenge and maternal malnutrition) that are all validated by disruption in PPI.
Cenajek, D., Szczawińska, K., Chodera, A. and Nowakowska, E.: Development of tolerance to pethidine in rats, pretreated or not, with ß-naphtoflavone or SKF 525 A. Acta physiol, pol., 1988, 39 (4): 281-287. Tolerance to the analgesic effect of pethidine (PD) in rats, treated with a dose of 15 mg/kg of the compound twice daily at 12 h intervals for 1-3 weeks, was assessed using both, heat and current irritating stitnuli, (Tolerance could be detected earlier by the current irritating method, .than by the hot plate technique. Pretreatment with β -naphtoflavone did only slightly affect the development of tolerance to the antinofciceptive effect of (PD. In contrast after one week of treatment with SKF 525 А PD retained its1 analgesic effect. The prolonged pretreatment with SKF 525 A did not prevent the development of tolerance to the analgesic effect of PD.
The paper presents the problem of the financial access to medications and possibilities to improve the situation. One of the possibilities is the legal practice of parallel import. The problem of differences in medication prices is vital, for they are substantial between various countries. The paper points out that efforts to enable patients to take efficacious medicine, regardless of the place of residence, are necessary.
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Szczawińska, K., Cenajek-Musiał, D., Nowakowska, E. and Chodera, A.: Pharmacokinetic disposition of pethidine under tolerance. Acta physiol pol., 1989, 40 (4): 374-380. Under tolerance, evoked by multiple doses of pethidine (PD), the serum and brain tissue content of PD was related to diminished analgesic activity. Even though in tolerant rats no enhancement of PD biotransformation in the liver could be recognized (as followed by the measurement of hepatic esterase and N-demethylase activity), the amounts of both PD and nor-PD excreted in urine were increased under tolerance. The authors conclude that the faster disposition of PD may contribute to the development of tolerance.
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L-deprenyl in the dose of 0.25 mg/kg (the dose with no effect on locomotor activity) was administered to Wistar rats in single and prolonged treatment (21 days). In the same manner carboxymethyl cellulose was given to the control group. In the forced swimming test the rats from the deprenyl group showed reduced immobility time only once, after 7 days of treatment, as compared with the control group. In the Crawley’s test one parameter was increased after deprenyl — the white square entries (WSE), showing that the rats were emboldened to move more freely in the white, lighted area. In the maze test the most important observations were that deprenyl shortened the food finding time and significantly counteracted the elongation of this time after scopolamine. The authors discuss the possibility that deprenyl has a modulatory effect on learning and memory and this effect depends on the dose used. It seems also that the increase of monoamine and cholinergic transmission may be involved. The small antidepressant and anxiolytic effect may be due to the metabolites of deprenyl of the amphetamine group.
Alcoholism is a chronic and recurrent disease. The studies on ethyl alcohol show a progressive deterioration of cognitive functions (motor hyperactivity, operating memory). The aim of the study was to establish whether combined single and chronic administration of aripiprazole (ARI) and fluoxetine (FLU) affects animal locomotor activity or modifies spatial memory functions in female rats exposed to ethyl alcohol. Female Wistar rats were studied in the Morris Water Maze (MWM) and locomotor activity test. Rats undergoing the MWM and locomotor activity test were injected with saline on day 1, 7, 14 and 21 of testing. Results showed a statistically significant mobility increase in the group of ethanol‑exposed females (CEt) (21 days) compared to the non‑ethanol‑exposed group (CNEt). Upon ARI administration to CEt, no statistically significant differences in animal mobility were found, either upon single or chronic administration. Chronic administration of FLU (21 days) as well as combined administration of ARI+FLU (14 and 21 days) caused a statistically significant reduction of the females’ mobility compared to the control CEt group. Single and chronic administration of ARI (7x) both show a spatial memory improvement in CEt. No memory improvement was observed, however, after 14 and 21 days of ARI administration. FLU, likewise, improved spatial memory both upon single and chronic administration. Combined administration of ARI+FLU improved memory in CEt only upon single administration. Lack of effect upon chronic administration may be due to tolerance to memory improvement developing upon combined administration of ARI+FLU. It can be concluded that ARI (1.5 mg/kg), FLU (5 mg/kg), and combined administration of these drugs improves spatial memory in CEt.
Celem artykułu jest ocena wpływu rozpoznania podłoża gruntowego na posadowienie konstrukcji. Podstawą do opracowania były dokumentacje archiwalne (pierwotna i wtórna), między którymi stwierdzono znaczne rozbieżności. Projekt posadowienia analizowanego obiektu wykonano według pierwotnej dokumentacji, w której nie uwzględniono występowania w podłożu gruntów organicznych. W celu określenia znaczenia rozpoznania podłoża gruntowego przy wyborze posadowienia dokonano weryfikacji stanów granicznych posadowienia w obu dokumentacjach. Największe różnice stwierdzono przy obliczonym osiadaniu, które wynikły z uwzględnienia wpływu ściśliwości gruntów organicznych.
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