117 research outputs found

    Biochemical, histological and histochemical changes in Aristichthys nobilis Rich. liver exposed to thiamethoxam

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    Background and purpose: The aim of the present study was to investigate the effects of the insecticide thiamethoxam on some biochemical, histological and histochemical parameters of bighead carp liver (Aristichthys nobilis), which is an economically important fish species for aquaculture. Materials and methods: Different increasing concentrations of 6.6 mg l-1, 10 mg l-1 and 20 mg l-1 of the test chemical under laboratory conditions were tested for their toxicity on fish for 96. The hepatic activity of the enzymes lactate dehydrogenase (LDH), aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) were measured. In addition, the hepatic histological structure was observed for alterations, as well as the lipid content was observed by histochemical staining. Results: It was determined that the enzymatic activity of the exposed fish was increased compared to the control group (p<0.05). Furthermore, the enzymatic activity was increased proportionally to the increasing thiamethoxam concentrations. The histological lesions, which were observed in the liver parenchyma, were degenerative and necrotic. The degenerative alterations were as follows: granular, balloon and fatty degeneration. The necrotic alterations in the fish liver were associated with presence of karyopyknosis, karyorrehsis and karyolysis, respectively. The histological alterations in the liver blood vessels were hyperemia and lymphocyte proliferation. Along with the established histological changes in the liver parenchyma, we found presence of fatty degeneration in the hepatocytes using Sudan III staining on cryostat sections. Conclusions: Our study shows that there is a relation between the concentration of the insecticide and biochemical changes, as well the severity of expression of the histological and histochemical alterations in the bighead carp liver. Overall, such experiments could be successfully applied in research and monitoring programs to study the effects of pesticides on fish

    Auxin pretreatment promotes regeneration of sugarcane (Saccharum spp. hybrids) midrib segment explants

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    We have developed a new, simple, quick and genotype-independent method for direct regeneration of sugarcane using novel midrib segment explants. Our protocol involves two steps: the pretreatment of starting material on MS (Murashige and Skoog (1962) Physiol Plant 15:473–497) medium containing 3.0 mg/l 2,4- dichlorophenoxyacetic acid (2,4-D) for 8 days under continuous dark and subsequent transfer of the explants to MS medium augmented with 0.1 mg/l benzyladenine (BA) and 0.1 mg/l naphthaleneacetic acid (NAA) under light-dark conditions. On the regeneration medium, numerous globular structures appeared from the explants and subsequently differentiated into shoots. Regenerated shoots attained 2–5 cm height within 30 days of culture initiation and readily rooted on MS basal medium. Hardened plants were successfully established in the greenhouse. The regulation of sugarcane morphogenesis by auxin pretreatment is discussed

    Asian dust-storm activity dominated by Chinese dynasty changes since 2000 BP

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    The Asian monsoon (AM) played an important role in the dynastic history of China, yet it remains unknown whether AM-mediated shifts in Chinese societies affect earth surface processes to the point of exceeding natural variability. Here, we present a dust storm intensity record dating back to the first unified dynasty of China (the Qin Dynasty, 221–207 B.C.E.). Marked increases in dust storm activity coincided with unified dynasties with large populations during strong AM periods. By contrast, reduced dust storm activity corresponded to decreased population sizes and periods of civil unrest, which was co-eval with a weakened AM. The strengthened AM may have facilitated the development of Chinese civilizations, destabilizing the topsoil and thereby increasing the dust storm frequency. Beginning at least 2000 years ago, human activities might have started to overtake natural climatic variability as the dominant controls of dust storm activity in eastern China

    Incresing the efficiency of heat and mass exchange in an improved rotary film evaporator for concentration of fruit-andberry purre

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    An improved model of a rotary film evaporator with a cutting blade having a reflective surface and equipped with an autonomous heating system which is fed by a power supply from Peltier elements. The reflective surface of the advanced cutting blade had an area of 0.06 m2 and was heated by a flexible film resistive electric heater of radiating type with a ~15...20 W power supply. This solution provides additional heating and mixing and helps to capture the cut-off layer of puree while reducing the useful surface of the working chamber by 7 %. Most evaporators have a low heat transfer coefficient reducing the energy content of the process and final quality of the product. The heat exchange efficiency can be increased by improving the design of the film-forming element of the rotary film evaporator. The use of the proposed cutting blade with a reflective surface enables an increase in the heat transfer coefficient by approximately 20 % compared to the basic rectangular blade design. When comparing the calculated data, it can be concluded that the main indicator of resource efficiency, namely specific energy consumption for heating a unit volume of product in the RFE amounts to 408 kJ/kg compared to 1,019 kJ/kg with the basic vacuum evaporator which means a 1.97 times consumption reduction. The duration of heat treatment in the RFE is 60 s compared to 1 h in the basic VE which shows a significant reduction of raw material exposure to high temperatures. The obtained data show the effectiveness of engineering and technological solutions. The engineering and technological component of any heat and mass exchange processes, in particular the concentration of fruit-and-berry raw materials, is the main component in the production of semi-finished food products of a high degree of readiness

    Ginkgo Biloba Extract Ameliorates Oxidative Phosphorylation Performance and Rescues Aβ-Induced Failure

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    Energy deficiency and mitochondrial failure have been recognized as a prominent, early event in Alzheimer's disease (AD). Recently, we demonstrated that chronic exposure to amyloid-beta (Abeta) in human neuroblastoma cells over-expressing human wild-type amyloid precursor protein (APP) resulted in (i) activity changes of complexes III and IV of the oxidative phosphorylation system (OXPHOS) and in (ii) a drop of ATP levels which may finally instigate loss of synapses and neuronal cell death in AD. Therefore, the aim of the present study was to investigate whether standardized Ginkgo biloba extract LI 1370 (GBE) is able to rescue Abeta-induced defects in energy metabolism
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