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排序方式: 共有1016条查询结果,搜索用时 62 毫秒
101.
Abstract. Carbon dioxide anaesthesia differentially affects the knockdown and recovery of cockroaches, depending on the strain and the length of time that the colony has been subjected to a CO2 regime. Adult males from two laboratory and two field-collected strains of German cockroaches, Blattella germanica, are knocked down within 7–45 s after exposure to CO2. After 5 min of CO2 exposure, presumptive recovery (i.e. the time for the cockroach to right itself after knockdown) for laboratory strains occurs significantly sooner than for field-collected strains. Control cockroaches, exposed to compressed air rather than CO2, exit harbourage cups rapidly (≤3.20 min). However, although allowed a recovery period of 5 min, significant movement impairment occurs for all cockroach strains anaesthetized with CO2. Carbon dioxide exposure significantly reduces consumption of 2.15% hydramethylnon bait and delays mortality even when 24 h is allowed for recovery before bait placement. Cockroaches allowed to recover for 48 h after 5 min of CO2 exposure consume significantly more bait and die significantly faster than CO2 exposed groups allowed 24 h of recovery, and mortality is not significantly different from nonanaesthetized bait-fed controls. 相似文献
102.
A single intraperitoneal injection of DL-methionine (500 mg/kg body wt.) to adult male Wistar rats was shown to significantly
induce all the components of the hepatic microsomal mixed function oxidase system such as NADPH cytochrome C reductase activity,
cytochromes P-450 and b5, as well as activities of drug metabolizing enzymes such as aminopyrine demethylase and uridine 5′ -diphosphate-glucuronosyltransferase.
Combined administration of nicotinamide (250 mg/kg body wt.) and DL-methionine (500 mg/kg body wt.) was shown to bring about
an additional increase (25-30%) in the activities of these enzymes as compared to their induction on independent administration
of the two endobiotics. In rats bearing Yoshida sarcoma (ascites) tumour as well as in normal rats injected with serum from
tumour bearing animals, the decreased activities of hepatic mixed function oxidases could be restored to their normal levels
by administration of DL-methionine (500 mg/kg body wt.) to these rats. Whereas actinomycin D (1 mg/kg body wt.) had no effect
on the increased incorporation of [14C] labelled leucine into microsomal proteins following administration of nicotinamide, the enhanced incorporation of the label
following DL-methionine administration was completely inhibited by the same dose of actinomycin D. Administration of cycloheximide
(0·5 mg/kg body wt.) to rats could completely inhibit the increased incorporation of [14C] leucine into hepatic microsomal proteins following independent administration of nicotinamide and DL-methionine. Similar
inhibitory pattern with actinomycin D and cycloheximide was also demonstrated in case of induction of NADPH cytochromeC reductase activity by both these endobiotics. 相似文献
103.
Normal and mutant human adenosine deaminase genes 总被引:2,自引:0,他引:2
104.
Maize (Zea mays L.) and ricebean (Vigna umbellata [Thumb.] Ohwi and Ohashi) were grown in intercrop and monoculture on Tropaqualf soils under rainfed conditions in Northern
Thailand yearly from 1983 to 1986. De Wit's replacement design was used to compare intercrops and monocultures with a constant
plant density equivalent to 80 000 maize or 160 000 ricebean plants ha−1. Combined nitrogen was applied at varying levels to 200 kg N ha−1. In the final two seasons the intercrop ratio of maize: ricebean was also varied. At the time of maize maturity intercrops
yielded upt 49 kg ha−1 more N in the above ground plant parts than the best monoculture. Dry matter, grain and nitrogen yield of maize and ricebean
in intercrop relative to their monoculture yields (RY, relative yield) were significantly greater than their respective share
of the plant population. Relative yield totals (RYT) for grain, dry matter and nitrogen were always greater than 1.
Nitrogen uptake per maize plant increased with progressive replacement of maize by ricebean plants. This increase was similar
to that obtained by applying combined N. Available soil nitrogen tended to decrease with increasing maize:ricebean ratio.
Increasing the maize:ricebean ratio increased the % of nitrogen derived from fixation in ricebean, the increase being equivalent
to that obtained by decreasing combined nitrogen application. Approximately the same amount of fertilizer and soil nitrogen
was taken up by maize plus ricebean in intercrop as the maize monoculture. The results suggest that the improved nitrogen
economy of the intercrop resulted from the strong competitiveness of maize in the use of mineral nitrogen and the enhancement
of nitrogen fixation in intercropped ricebean which made it less dependent on the depleted pool of soil nitrogen. 相似文献
105.
Paul M. O Neill Paul A. Stocks Sunil Sabbani Natalie L. Roberts Richard K. Amewu Emma R. Shore Ghaith Aljayyoussi I?igo Angulo-Barturén María Belén Santiago Ferrer Bazaga María Santos Martínez Brice Campo Raman Sharma Susan A. Charman Eileen Ryan Gong Chen David M. Shackleford Stephen A. Ward 《Bioorganic & medicinal chemistry》2018,26(11):2996-3005
A series of aryl carboxamide and benzylamino dispiro 1,2,4,5-tetraoxane analogues have been designed and synthesized in a short synthetic sequence from readily available starting materials. From this series of endoperoxides, molecules with in vitro IC50s versus Plasmodium falciparum (3D7) as low as 0.84?nM were identified. Based on an assessment of blood stability and in vitro microsomal stability, N205 (10a) was selected for rodent pharmacokinetic and in vivo antimalarial efficacy studies in the mouse Plasmodium berghei and Plasmodium falciparum Pf3D70087/N9 severe combined immunodeficiency (SCID) mouse models. The results indicate that the 4-benzylamino derivatives have excellent profiles with a representative of this series, N205, an excellent starting point for further lead optimization studies. 相似文献
106.
Smruthi G. Prabhu Govindan Srinikethan 《International journal of phytoremediation》2018,20(9):947-956
Biosorption is a surface-dependent phenomenon. Surface modifications by chemical treatment methods could either improve or reduce the biosorption capacity of potential biosorbents. In the present work, pristine Pteris vittata L. pinnae (PPV) powder was treated separately with sodium hydroxide (NaOH), calcium chloride (CaCl2), and nitric acid (HNO3). The pristine and treated biosorbents were used to assess the biosorption of Pb(II), Cd(II), and Cr(VI) as a function of pH. Kinetics and adsorption isotherms were studied. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and scanning electron microscope combined with energy dispersive x-ray (SEM-EDX) spectroscopic techniques were used to characterize the biosorbents before and after chemical treatments. The possible functional groups contributing to the metal sorption were identified. Results revealed favorable biosorption of Pb(II), Cd(II), and Cr(VI) described by pseudo-second order kinetics. NaOH-treated P. vittata (NPV) showed higher biosorption capacity for Pb(II) and Cd(II) compared to that of PPV. ATR-FTIR studies indicated that -OH, -COOH, and -NH2 groups were mainly involved in Cr(VI) and -OH in Pb(II) and Cd(II) biosorption. The enhanced efficiency of NPV and CaCl2 treated P. vittata (CPV) in the uptake of Pb(II) and Cd(II) compared to PPV can be associated with their altered physicochemical characters. 相似文献
107.
Echinocereus is a morphologically diverse genus that includes 64 species grouped into eight taxonomic sections based on morphological traits. In previous molecular phylogenetic analyses, the relationships amongst Echinocereus species were not entirely revealed and useful characters to recognize clades were not provided. The inclusion of several sources of evidence in a phylogenetic analysis is likely to produce more supported hypotheses. Therefore, we performed a combined phylogenetic analysis with a set of 44 morphological characters and six chloroplast DNA sequences. Topologies from parsimony and Bayesian analyses were mostly congruent. However, the relationships of E. poselgeri were not consistent between analyses. A second Bayesian analysis using a long-branch extraction test resulted in a topology with the morphological position of E. poselgeri congruent with that in parsimony analysis. Parsimony and Bayesian analyses corroborated the monophyly of Echinocereus, which included eight monophyletic groups. The combined phylogeny integrated into different clades those taxa that were not determined in previous analyses and changed the relationships of some recognized clades. The clades did not recover the recent infrageneric classification. In the present study, a new sectional classification for Echinocereus is proposed based on the eight recovered clades, which is supported by a combination of morphological and molecular characters. An identification key for sections in the genus is included. 相似文献
108.
Mustafa Durmuş Ali Rıza Kosker Yeşim Ozogul Mehmet Aydin Yılmaz UÇar Deniz Ayas 《人类与生态风险评估》2018,24(3):731-742
The effects of seasonal and sexual differences on the levels of macro, trace element, and toxic metal levels in Mullus barbatus were investigated using the ICP-MS. The quantity relationships of macro elements were found as K>P>Na>Ca>Mg for male, P>K>Na>Ca>Mg in female; the quantity relationships of trace elements were determined as Fe>Zn>Mn>Mo>Se>Cu>Ni>Co in male, Fe>Zn>Mn>Se>Cu>Ni>Mo>Co in female; and the quantity relationship of toxic elements were found as As>Pb>Cd in both male and female. Macro, trace, and toxic metal levels showed no significant differences (p > .05) in terms of sexuality, but demonstrated seasonal differences (p > .05). Overall, the highest level of macro elements was determined in the autumn, while the high level of trace elements was measured in the winter. The As, Cd, and Pb levels in the muscle tissue of red mullet fish were higher than acceptable limits. However, when the Estimated Daily Intake (EDI) and Estimated Weekly Intake (EWI) of both toxic metals are considered, they appear to be below acceptable limits. As a result, it was determined that the red mullet had been contaminated with toxic metals (Cd and Pb) but their levels according to EDI and EWI were below the limit. 相似文献
109.
Origin and potential ecological risk assessment of trace elements in the watershed topsoil and coastal sediment of the Oualidia lagoon,Morocco 总被引:1,自引:0,他引:1
Mehdi Maanan Meryem El Barjy Najwa Hassou Hakima Zidane Bendahhou Zourarah Mohamed Maanan 《人类与生态风险评估》2018,24(3):602-614
The Oualidia lagoon provides important ecosystem services, such as fishing, aquaculture, tourism and high biological and ecological productivity. Many indices have been developed to evaluate environmental risks and to estimate the anthropogenic contribution of potentially toxic elements (PTE) in surficial sediments. The results show that the concentrations of the PTE found in surface sediments due to the anthropogenic activities in the area (urban effluents, aquaculture and agricultural areas) are significantly higher than those from the local background and sediment quality guidelines (SQGs). The potential ecological and biological risk index present satisfactory results. However, the sites near to the areas where anthropogenic activities are developed present 49% probability of toxicity, while the rest of the lagoon, present 9% to 21% probability of toxicity and low potential ecological risk, except for Hg where the risk was considered to be considerable. The PTE are mainly originated from the anthropogenic activities; nevertheless, anthropogenic contributions represent up to 69% of the total sediment of content, but it depends on the PTE: Cd (16%), Ni (38%), Zn (41%), Cr (43%), Cu (56%), Hg (68%), Pb (69%). Compared with the Sub-basin soils, the PTE are higher than 80%, hence the sub-basin feeds the lagoon by these elements (PTE). 相似文献
110.
Thatjana Gardeitchik Miski Mohamed Benedetta Ruzzenente Daniela Karall Sergio Guerrero-Castillo Daisy Dalloyaux Mariël van den Brand Sanne van Kraaij Ellyze van Asbeck Zahra Assouline Marlene Rio Pascale de Lonlay Sabine Scholl-Buergi David F.G.J. Wolthuis Alexander Hoischen Richard J. Rodenburg Wolfgang Sperl Zsolt Urban Eva Morava 《American journal of human genetics》2018,102(4):685-695