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1.
The purpose of this work is to perform a detailed study of carbohydrate specificity of the new extracellular bacilli lectins which is considered to determine mechanisms of the lectins action. Sources of lectins were bacterial strains from Ukrainian collection of microorganisms. The optimized protocol of bacilli lectins isolation and purification included precipitation with ammonium sulfate with subsequent gel filtration chromatography on Sepharose CL-6B. Hemagglutinating activity of bacilli lectins and their fine carbohydrate specificity to sialic acids and their derivatives as well as sialic asid-containing and asialic glycoconjugates were studied. The ability of extracellular bacilli lectins to discriminate a- and 13-conformation of carbohydrate molecule and the type of connection between the monomers was determined. Studied lectins showed the most affinity to glycoconjugates containing both types of sialic acids (N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (NeuGc)) and it is supposed to be a basis of their diagnostic and analytical potential.  相似文献   
2.
The schemes for fractionation of soil microelement compounds were analyzed. A scheme of extracting As compounds that are sorbed specifically and nonspecifically and bound with oxides (hydroxides) of Fe, Al, Mn, organic matter, carbonates, and soil minerals is proposed. The scheme differs from the existing ones in the higher selectivity of extracting the fractions due to changes in the combination of the extractants and the sequence of their use.  相似文献   
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4.
Objectives To investigate whether there are any changes in the tidal breathing flow volume loop (TBFVL) in calm, non-dyspnoeic dogs with intratracheal masses. Methods We compared 4 dogs with intratracheal masses (group 1) with 10 healthy dogs (group 2). Routine clinical and laboratory examinations of the dogs were unremarkable, except for episodic upper respiratory obstructive signs in the dogs in group 1. Lateral radiography of the neck and thorax showed that group 1 dogs had masses that appeared to protrude into the tracheal lumen. Tracheoscopy and surgery or necropsy was performed to confirm the presence of the mass. Arterial blood gas and TBFVL analysis was carried out in all dogs to assess respiratory status. Results The shape of the TBFVL for dogs in group 1 was narrower and ovoid compared with that for the group 2 dogs. Tidal volume and expiratory and inspiratory times were significantly reduced, whereas the respiratory rate was increased for dogs in group 1 compared with dogs in group 2. Arterial blood gas analysis was unremarkable for all dogs. Conclusions TBFVL is a non-invasive technique that is easy to perform and well tolerated by dogs. In the absence of abnormalities detected by routine diagnostic evaluations and arterial blood gas analysis in dogs with intratracheal masses, the TBFVL contributes to the definition of the physiologic status of the airways at the time of testing, and results suggests that these dogs breathe quite normally when they are calm and non-dyspnoeic.  相似文献   
5.
Antidepressant drugs and psychotherapy combined are more effective in treating mood disorders than either treatment alone, but the neurobiological basis of this interaction is unknown. To investigate how antidepressants influence the response of mood-related systems to behavioral experience, we used a fear-conditioning and extinction paradigm in mice. Combining extinction training with chronic fluoxetine, but neither treatment alone, induced an enduring loss of conditioned fear memory in adult animals. Fluoxetine treatment increased synaptic plasticity, converted the fear memory circuitry to a more immature state, and acted through local brain-derived neurotrophic factor. Fluoxetine-induced plasticity may allow fear erasure by extinction-guided remodeling of the memory circuitry. Thus, the pharmacological effects of antidepressants need to be combined with psychological rehabilitation to reorganize networks rendered more plastic by the drug treatment.  相似文献   
6.
The objective of this study was to determine the number, morphology and ultrastructure of preantral ovarian follicles of buffalo (Bubalus bubalis) foetuses at different ages. Quantification revealed number of primordial, primary and secondary follicles of 48 857 ± 17 506, 26 000 ± 20 452, 18 428 ± 10 875 and 18 375 ± 19 690, 225 ± 349, 326 ± 288 at 12–34 cm and 35–60 cm crown rump length (CRL), respectively. Follicular diameter values were 28.9 (±3.4), 34.7 (±5.9) and 59.4 (±12.6) μm; oocyte diameters were 21.7 (±2.8), 24.3 (±3.4) and 33.0 (±7.7) μm, and the numbers of follicular cells in the follicle equatorial section were 7.1 (±1.4), 12.0 (±2.4) and 13.8 (±2.4) for primordial, primary and secondary follicles, respectively. The primordial follicle consisted of an oocyte surrounded by a layer of flattened follicular cells with a normally eccentric oocyte nucleus. Dispersed Golgi complex, smooth endoplasmic reticulum, rounded mitochondria and several lipid vesicles were observed in the cytoplasm and cell junctions between the follicle cell membranes and the oocyte. This work describes the number, morphometry and ultrastructure of preantral follicles of buffalo foetuses, concluding that folliculogenesis is established between 8 and 34 cm CRL and that follicle number varies individually and according to age and that further studies are needed in this species.  相似文献   
7.
On the basis of clinical signs and histological findings eight 9-month-old male rusa deer ( Cervus timorensis ) were diagnosed with sheep associated-malignant catarrhal fever. Following a variable course involving rectal temperatures around 40.5°C, depression, inappetence, diarrhoea, corneal opacity and hypopyon all animals died or were euthanased over a 5-week period. Severe multifocal vasculitis, mainly periglomerular and in the arcuate vessels were consistent histological findings which in the past have been adequate to confirm clinical diagnosis of sheep associated-malignant catarrhal fever. A nested poly-merase chain reaction test has been used to detect a sheep associated-malignant catarrhal fever PRC product, 238 base-pairs in size, in DNA extracted from lymphocyte preparations. The result supported the diagnosis of sheep associated-malignant catarrhal fever in these deer.  相似文献   
8.

Purpose

The main goal of the study was to evaluate biogeochemical effects of particular factors changing the structure of landscapes due to enhanced mass migration and erosion of the outcropping rocks by studying transformation of chemical composition of the draining waters and flood plain soils; chemical composition of the solid and liquid phases of the Ardon River waters; and by assessing ecological consequences and risk of contamination of the area by heavy metals.

Materials and methods

Water, soil, and biota species (plants, algae, and amphibian) were sampled at the plots located up- and downstream the mining and industrial areas of North Ossetia (the Ardon River basin) before and after the mudflow that took place in 2002. The air-dried samples were decomposed in a mixture of mineral acids. Heavy metals were determined by means of AAS with the help of AAS-80 (Hitachi) or AAS-2A (KORTEC) using standard reference materials of hair (CRM 397), plant mixture (SBMT-02), and soil (SRM 2709). Hydrochemical and biochemical analyses were performed with the help of the known methods (Kraynov and Shvets 1992; Burtis et al. 2006).

Results and discussion

The study showed that activity of the Misur Mining Combine and its Ardon-Khost tailings caused a significant local increase of Pb, Cd, Cu, and Zn content in soils, water, and biotic components as compared to the background values. The mudflow of 2002 changed the structure of landscapes and was followed by a considerable transformation of chemical composition of the downstream river waters and floodplain soils, and by invasion of particular hydrophyte species. Algae and amphibian adapted to the changed conditions and indicated both natural and anthropogenic transformation of the environment. A distinct relation between the particle size of the suspended matter in the Ardon River waters and water salinity was discovered.

Conclusions

Therefore, the Unal basin presents a vivid example of modern natural and anthropogenic evolution of Pb-Zn biogeochemical province under conditions of the extreme and dynamic geochemical environment leading to enhanced risks of ecological damage. Algae species demonstrated high adaptive and indicative capacity in case of both the fast natural and man-made impact.
  相似文献   
9.
The long-term application of different mineral fertilizers in field experiments conducted at the Dolgoprudnaya and Luberetskaya agrochemical experimental stations and in the Chashnikovo Training and Experimental Soil-Ecological Center of Moscow State University resulted in an increase in the content of nonsilicate iron in soddy-podzolic soils of different texture, compared to the control (unfertilized) soils, which could be caused by an enhancement of the soil weathering. The greatest effect on the soil weathering was observed for nitrogen (ammonium nitrate) and potassium (potassium chloride) fertilizers. Periodic liming decreased the content of the nonsilicate iron minerals. The citrate-dithionite solution extracted 50 to 80% of the total zinc and 37 to 82% of the total strontium from the soil, which were probably bound to the nonsilicate iron compounds. The latter participate in the redistribution of the strontium arriving to the soil with phosphoric fertilizers: the content of the metal passed into the citrate-dithionite extract from the soil treated with simple superphosphate for a long time period and was 1.3 times higher than that extracted from the control soil.  相似文献   
10.
On the basis of a differentiated analysis of a number of elements and crystal chemistry of minerals in fractions with a size < 1, 1–5, and 5–10 μm, data are obtained on reserves of plant nutrient elements in agrogray heavy loam soils of Vladimir opolie.  相似文献   
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