949 resultados para Substances psychoactives


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当前,水资源污染越来越严重,人类的健康面临着巨大的威胁。高级氧化技术作为一 种经济、高效、无二次污染的水体处理方法,一直是水污染控制与治理领域研究的热点。 本文以环境中典型的有机污染物苯酚和水体中主要有机物腐殖酸为研究对象,利用自 制的紫外光(ultraviolet,UV)离线降解装置,采用紫外-可见光谱法和总有机碳(TOC) 分析法分别研究水相中苯酚、腐殖酸的紫外光降解情况,系统地考察不同初始pH值、初始 浓度、光照时间、光照强度、反应容器等因素对光降解效果的影响。为了模拟实际水体条 件和提高光降解效率,在体系中分别加入NaCl、Na2CO3、NaNO3、NaNO2和双氧水等化学 成分,探讨这些化学物质对苯酚、腐殖酸的紫外光降解效率和降解途径的影响。最后,首 次构建了石英螺旋管内壁负载TiO2膜的在线降解装置,结合UV/H2O2/TiO2联用体系,进行 海水中有机物的光降解研究。 紫外可见光谱分析表明:光降解速率随初始pH 值的降低而提高,相同条件下苯酚在 酸性溶液中降解速率高于碱性溶液,说明苯酚分子比酚氧离子容易光降解;硝酸钠和亚硝 酸钠有利于苯酚的光降解,说明它们在紫外光下容易分解生成自由基;在苯酚水溶液中加 入双氧水,光照15 min 后,光降解效率达到97%。各种介质中苯酚的降解速率大小依次为: 1.5 mmol/L 过氧化氢溶液 > 1.0 mmol/L 硝酸钠的海水 > 海水 > 纯水 > 0.5 mol/L 氯化钠溶液。然而,TOC 数据显示氯化钠的存在对苯酚的矿化有促进作用;同光谱的降解 速率相比,矿化速率要小。 腐殖酸的光降解效率随初始质量浓度的减小而提高,当质量浓度为10 mg/L时,光照 30 分钟后,降解效率高达到88%;初始pH值对腐殖酸的降解效率影响很大,腐殖酸在碱 性条件下比在中性和酸性条件更容易光降解;硝酸钠等盐分对中性和碱性溶液中腐殖酸的 光降解没有明显促进作用,但对酸性溶液中腐殖酸的光降解促进作用明显。采用UV/H2O2联 合降解时,腐殖酸降解效率得到显著提高。 相比离线降解方式,采用石英螺旋管在线降解苯酚和腐殖酸,降解效率均提高了15 倍 以上;海水经过在线降解后,紫外可见光光谱吸光度值缓慢下降;经过多次在线光降解后, 在290 nm波长处出现强烈吸收峰,再次光照后很快消失。这种现象表明海水中可能存在着 粒

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A study on the status of fisheries and environmental impact assessment (EIA) was conducted on Bashundhara Baridhara Housing Project (BBHP), Dhaka, Bangladesh for prediction and measure the effects of housing project related development activities that have already been implemented and planned for future implementation. The project is still under development phase and so far allotted 10,000 plots of different sizes. The study shows that the original water bodies and natural fish production there from have greatly declined due to earth filling carried out for development of land for the housing. The physico-chemical parameters of the existing water body within the project area were found to be suitable for fish farming in the estate. A number of economically important fish species are found available in the existing lake. However, the natural fisheries resources of the existing lake is under great stress due to the changes made in the ecosystem, siltation, construction of building and dumping of house building and household waste materials. This has caused some important fish species of the lake to become critically endangered and vulnerable which have been documented in this paper. Appropriate regulatory and mitigating measures with respect to water management, disposal of construction garbage and other biomedical toxic substances far away from the water bodies are required to be taken to keep the water safe and suitable for fish production as well as for multipurpose use of the lake water.

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The hornet possesses highly toxic venom, which is rich in toxin, enzymes and biologically active peptides. Many bioactive substances were identified from wasp venom. Two families of antimicrobial peptides were purified and characterized from the venom of

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Adverse effects of toxic substances on the environmental quality have become a subject of concern in recent years. Toxicity of heavy metals has never been in dispute and therefore their presence in our natural environment is undesirable. This study was undertaken to establish the capability of Perna viridis as a monitor for pollution in the Manora channel. Accumulation of Zinc, Copper, Iron and Manganese by marine mussels, sampled from Manora channel, was determined. Metal load varied markedly between individuals from the same populatin. This variability was partly accounted for systematic relationship between metal load and body weight and age. The distribution of metal between the major organs was considered, but the analysis of separate organs showed no advantage for their use as a biological monitor. comparison between Iron, Manganese, Copper and Zinc concentration in ambient sea water and in the mussel showed no clear correspondence. The results suggest that the mussel is capable of acting as a biological monitor, although may not be a good short term monitor of Iron, Manganese, Zinc and Copper. It may have potential as a long term and site comparison monitor for metals, once inherent variability is taken into account

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Horseflies are economically important blood-feeding arthropods and also a nuisance for humans and vectors for filariasis. They rely heavily on the pharmacological properties of their saliva to get a blood meal and suppress immune reactions of hosts. Little information is available on antihemostatic substances in horsefly salivary glands; especially no horsefly immune suppressants have been reported. By proteomics or peptidomics and coupling transcriptome analysis with pharmacological testing, several families of proteins or peptides, which act mainly on the hemostatic system or immune system of the host, were identified and characterized from 30,000 pairs salivary glands of the horsefly Tabanus yao (Diptera, Tabanidae). They are: (i) a novel family of inhibitors of platelet aggregation including two members, which possibly inhibit platelet aggregation by a novel mechanism and act on platelet membrane, (ii) a novel family of immunosuppressant peptides including 12 members, which can inhibit interferon-gamma production and increase interleukin-10 secretion, (iii) a serine protease inhibitor with 56 amino acid residues containing anticoagulant activity, (iv) a serine protease with anticoagulant activity, (v) a protease with fibrinogenolytic activity, (vi) three families of antimicrobial peptides including six members, (vii) a hyaluronidase, (viii) a vasodilator peptide, which is an isoform of vasotab identified from Hybomitra bimaculata, and interestingly (ix) two metallothioneins, which are the first metallothioneins reported from invertebrate salivary glands. The current work will facilitate the understanding of the molecular mechanisms of the ectoparasite-host relationship and help in identifying novel vaccine targets and novel leading pharmacological compounds.

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Blood-feeding arthropods rely heavily on the pharmacological properties of their saliva to get a blood meal and suppress immune reactions of hosts. Little information is available on antihemostatic substances in horsefly salivary glands although their sal

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Triglycerides, phospholipids and sarcoplasmic proteins fractions of white pomfret produced considerable amounts of thiobarbituric acid reactive substances (TBRS) on irradiation. Incubation of malonaldehyde with pomfret skin under aseptic conditions developed yellow pigmentation of the skin tissues, similar in spectral characteristics to those produced on irradiation of the skin.

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Some presently used anti-fouling materials contain metals and other compounds, which are toxic in the environment. Coating products are not always stable, and there is a resulting pollution hazard. In particular if surfaces are poorly prepared and manufactures' instructions are not closely followed the application of anti-fouling substances becomes pointless and dangerous. In addition the salinity, constant biological activity and suspended particles make seawater a highly corrosive material in its own right.

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The diversity and evolution of bitter taste perception in mammals is not well understood. Recent discoveries of bitter taste receptor (T2R) genes provide an opportunity for a genetic approach to this question. We here report the identification of 10 and 30 putative T2R genes from the draft human and mouse genome sequences, respectively, in addition to the 23 and 6 previously known T2R genes from the two species. A phylogenetic analysis of the T2R genes suggests that they can be classified into three main groups, which are designated A, B, and C. Interestingly, while the one-to-one gene orthology between the human and mouse is common to group B and C genes, group A genes show a pattern of species- or lineage-specific duplication. It is possible that group B and C genes are necessary for detecting bitter tastants common to both humans and mice, whereas group A genes are used for species-specific bitter tastants. The analysis also reveals that phylogenetically closely related T2R genes are close in their chromosomal locations, demonstrating tandem gene duplication as the primary source of new T2Rs. For closely related paralogous genes, a rate of nonsynonymous nucleotide substitution significantly higher than the rate of synonymous substitution was observed in the extracellular regions of T2Rs, which are presumably involved in tastant-binding. This suggests the role of positive selection in the diversification of newly duplicated T2R genes. Because many natural poisonous substances are bitter, we conjecture that the mammalian T2R genes are under diversifying selection for the ability to recognize a diverse array of poisons that the organisms may encounter in exploring new habitats and diets.

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Production of bioethanol through acidic and enzymatic hydrolysis of aquatic Azolla sp., as a new source of bio-mass, has been performed, as a means to control increasing growth and reducing undesirable effects of this plant in Anzali lagoon. After sampling, drying and crushing, Azolla was hydrolyzed, using diluted acid and enzyme. Diluted acid hydrolysis was done using both autoclave and a high-pressure system (Batch Synth® Microwave synthesizer). The effects of temperature and time (in autoclave) and concentration of acid (in both) were compared. Cellubrix®, a ommercial cellulase source, was used for enzymatic hydrolysis process. The amounts of reducing sugars, glucose and furfural, released from hydrolyzate, were measured. To produce alcohol, Sacchromyces cerevisiae (to ferment sixcarbon sugars), Zygowilliopsis californica and Pichia stipitis (to ferment five-carbon and sixcarbon sugars) were used. Maximum amounts of glucose (4.83% w/w) and reducing sugars (14.15% w/w) were obtained using acid hydrolysis in autoclave. In the microwave oven, maximum glucose (5.04% w/w) and reducing sugars (13.27 w/w) were obtained at 180 and 200 °C, respectively. Under these conditions, maximum produced furfural was 1.54 g/L. The difference between amounts of furfural obtained from acid hydrolysis of Azolla in microwave oven compared to autoclave was statistically significant. Amounts of alcohol produced and its yields were 3.99 g/L and 33.13% for S. cerevisiae in 48 hours, 3.73 g/L and 30.45% for Pichia stipites in 48 hours, and 3.73 g/L and 30.45% for Z. californica in 24 hours after inoculation, respectively, with significant differences. Statistical comparison of results showed significant differences (P<0.05) in glucose production, at different conditions. Amounts of reducing sugars and glucose increased after optimization of levels of acid, time, and temperature. The overall optimum released sugar and glucose were obtained with 1.67% (w/v) acid using autoclave. Higher temperatures in microwave oven caused a significant increase (P<0.05) in furfural. Furfural severely inhibits fermentation. Hence, regarding the issues of energy consumption and time, amounts of inhibiting substances and sugar production, autoclave is found to be superior to the high temperature and pressure, generated in microwave oven, for hydrolyzing Azolla. Furthermore, given the amounts of Azolla in Anzali lagoon, it may be recommendable to use this plant as a biomass resource.

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Fish are an important part of a healthy diet since they contain high quality protein, but typically present a low fat percent when compared to other meats. Fish is an extremely perishable food commodity. On the other hand, food borne diseases are still a major problem in the world, even in well-developed countries. The increasing incidence of food borne diseases coupled with the resultant social and economic implications means there is a constant striving to produce safer food and to develop new antimicrobial agents concerns over the safety of some chemical preservatives and negative consumer reactions to preservatives they perceive as chemical and artificial, have prompted on increased interest in more ‘‘naturalgreen’’ alternatives for the maintenance or extension of product shelf-life. Particular interest has focused on the potential applications of plant essential oils. However, to establish the usefulness of natural antimicrobial preservatives, they must be evaluated alone and in combination with other preservation factors to determine whether there are synergistic effects and multiple hurdles can be devised. In this study, were evaluated the effects of different concentrations of Rosmarinus officinalis and nisin and storage time (15 days) on growth of Streptococcus iniae GQ850377 in a lab conditions and a food model system (fillets of rainbow trout) in 4 and 8 °C. In addition, we also studied multi factorial effects of four different concentration of rosemary, three different concentrations of nisin, two different levels of pH in 3 temperature 4,15 and 37 °C on log% of S.iniae during 43 days in BHI broth. The results on growth of S. iniae were evaluated using SPSS 20.0 statistical software and analyzed the logarithm of total count of the bacterial by Tukey Test. Results were considered statistically significant when P<0.05. MIC and MBC values of rosemary and nisin were 0.03, 0.075 % and 5, 40 μg/mL, respectively. The growth of S. iniae was effected significantly (P<0.05) by rosemary and nisin and also combination of rosemary and nisin in 4 and 8 °C. Samples treated with 0.135 and 0.405 % of rosemary showed a significant decrease on the growth of the bacteria compared with control sample(P<0.05). The most ١٤٦ inhibitory effects were seen in samples treated with 0.135 and 0.405% of rosemary until 9 days after storage. Also, the synergism effects of rosemary and nisin on the growth rate of bacteria was significant (P<0.05) compared with untreated samples and samples treated with the rosemary or nisin, only. Synergistic effects was observed at concentration of 0.405% rosemary and 0.75 μg/mL nisin in both temprature. Results of this study showed that different concentration of rosemary a significant inhibitory effect (P<0.05) on log% of S. iniae, in BHI broth in pH 5.5 and 7 in 4,15 and 37 °C during 43 days. In concentration of 0% rosemary (control) in pH 5.5 and 7 and 37°C, log% were 1.099 and 3.15, whereas in concentration of 0.015% rosemary were -4/241 and 1.454, respectively. The use of essential oils may improve food safety and overall microbial quality. If essential oils were to be more widely applied as antibacterials in foods, the organoleptic impact would be important. In addition, it is recommended to apply essential oils or their compounds as part of a hurdle system and to use it as an antimicrobial component along with other preservation techniques. Thus essential of R. officinalis with high antibacterial activity selected in this study could be a potential source for inhibitory substances against some food-borne pathogens and they may be candidates for using in foods or food-processing systems.

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Trace elements associated with organic subfractions (humic, fulvic, and non-humic substances) were identified for seven core sediments from Lake Mariut, Egypt. Results indicated that the amounts of trace metals in humic acid and non-humic substances decreased in the following order: Zn>Cu>Pb>Cr>Cd, while in fulvic acid the order the order was Cu>Zn>Pb>Cr>Cd. There is a higher contribution of Zn, Pb, Cu and Cr in humic acid compared to fulvic acid in most samples. Slight changes in the amounts of cadmium bounded with humic and fulvic acids was also found.

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The effect of adenosine on the function of the heart in Octopus vulgaris was studied using an isolated heart preparation. Bolus injections of adenosine or AMP (adenosine precursor) induced both positive chronotropic and inotropic effects. The maximum inotropic effect preceded the maximum chronotropic effect. The impermeable adenosine analogue 2-chloroadenosine elicited a similar effect, while the adenosine uptake blocker dipyridamole did not affect the adenosine response. These results suggest that adenosine acted extracellularly. The concentration-response curves of adenosine and AMP were also determined, by evaluating the effects on ventricular and coronary function. Under these conditions, the potent chronotropic effect elicited by both substances apparently masked or compensated for the inotropic effect, owing to the negative force-frequency relationship known to occur in the octopus heart. The AMP displayed a lower threshold than adenosine, suggesting an higher affinity for the purinergic receptors involved or a strict association between 5'-nucleotidase and the adenosine receptor on the plasma membrane.

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Prebiotics are non-digestible food ingredients that profitably affect the host by selectively stimulating the growth and /or activation of one or a limited number of bacteria in the intestine that can enhance host health status. Immunoster (IS) and Immunowall (IW) are prebiotics and immunostimulants derived from the outer cell wall of brewers yeast, Saccharomyces cerevisiae. These substances contain MOS and �-glucans. After a four-week acclimatization period to rearing conditions and basal diet, 450 farmed great sturgeon juveniles weighing 95.58 ± 9.38 g were randomly distributed into 15 fiberglass tanks (2 × 2 × 0.53 m) in five treatments (Control, IS 1%, IW 1%, IS 3%, and IW 3%) in three replicates (completely randomized design) and kept at a density of 30 fish per tank for a period of 8 weeks at water temperature 20.55 ± 5.11ºC, dissolved oxygen 6.73 ± 0.35 mg L-1 and pH 7.92 ± 0.09. IS and IW were added at two levels of 1% and 3% to the basal diet in place of cellulose, except the control. At the beginning, in the middle and at the end of the trial, carcass analysis was done to determine the moisture, protein, fat, ash, and total carbohydrate. Also, blood samples were collected to measure hematological, biochemical and immune indices. At the end of the trial, final weight, final length, body weight increase (BWI), specific growth rate (SGR), average daily growth (ADG), protein efficiency ratio (PER), feed conversion ratio (FCR), and condition factor (CF) in fish fed on IS and IW in both levels 1% and 3% showed some differences. These differences were significant in IS 3% and IW 1% and 3% compared with the control (P<0.05). HSI showed no significant difference (P>0.05) and survival rate was 100% in all treatments. Crude protein of carcass in fish fed on IS and IW at 1% and 3% showed an increase in comparison with the control. There was significant difference between IS 3% and the control in crude protein of carcass (P<0.05). Fish fed on IS and IW at 1% and 3% showed various results in hematological and biochemical factors. It was observed significant difference in MCV between IW 1% and IS 3% compared with the control (P<0.05). Although there was an increase in values of hematocrit, hemoglobin (except IS 1%), WBC (except IW 3%), MCH, neutrophil, total protein, albumin (except IS 3%), K+, and lysozyme in fish fed on IS and IW compared with the control, it was no significant (P>0.05). The maximum count of WBC and the highest value of Ca2+ were seen in IW 1%. The maximum count of lymphocyte, the highest values of total protein, albumin and IgM were recorded in IW 3%. IS 1% had the maximum count of neutrophil and the highest concentration of lysozyme. Based on obtained results, it can be declared that IS and IW at two levels of 1% and 3% can enhance growth performance and feed efficiency and also improve some hematological, biochemical, and immune indices in farmed great sturgeon juveniles.

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In this project sampling was done from 9 stations in 3 depths during 5 seasons to separate, identify and examine the biodiversity of cyanobacteria. Another sampling also has been done to analyse all physical and physicochemical parameters, primary production and polluting agents such as heavy metals and oil hydrocarbons in water and sediments. Along with optimization of Oscillatoria to study the ability of producing natural substances, these cyanobacteria were analysed from the point of antimicrobial and mutagenic effects. To examine the relationships among analysed parameters, the regression test, analysis of varian and Post Hoc were used. As the result of this study 48 genus of cyanobacteria were pecognised among which 35.5% were croco ccales and 64.4% were Hermogonals. Oscillatoria was one of the Filamentous cyanobacteria which had antibacterial and mutagenic effects. The results of multicommunity consistency varians test, post Hoc and homogenous subsets show significant difference between biodiversity of cyanotbacteria in coral ecosystem, Mangrove and transite. The linear correlation coefficient between biodiversity of cyanobacteria and bioenvironmental agents were examined, but there was no continuous relation between these factors and biological biodiversity. In Surface layer there was a significant correlation coefficent at 0.048 and probability at 95% confidence interval. Also, the biodiversity is depended on oil pollution and heavy metals such as copper (Cu) and chromium (Cr).