Search results for "Roth"

Sublethal bioconcentration of fenitrothion in the blood and brain of the european eel.

1998

Pesticide toxicokinetics in fish: accumulation and elimination.

1998

Bioaccumulation of fenitrothion in the European eel (Anguilla anguilla) was studied using two sublethal concentrations of this pesticide in a flow-through test system. The pesticide concentrations used were one-tenth (0.002 ppm) and one-fifth (0.04 ppm) the 96-h LC50 of fenitrothion in this species. Steady state was reached early (2 h) when the animals were exposed to 0.02 ppm of toxicant, and after 48 h when the animals were exposed to 0.04 ppm. Toxicokinetic parameters for fenitrothion in eel muscle (K1, K2, and T1/2) were calculated for both experiments. The highest bioconcentration factor was calculated for animals exposed to 0.04 ppm of toxicant, indicating the relationship between the…

Physiological stress responses ofAnguilla anguillato fenitrothion

1996

The present communication deals with the effect of fenitrothion (0.04 ppm) on the carbohydrate metabolism of the european eel Anguilla anguilla and its recovery from intoxication. Analysis of various parameters such as glycogen, lactate and glucose was made on different eel tissues after 2, 8, 12, 24, 32, 48, 56, 72 and 96 hr of fenitrothion exposure. Subsequently, the fish were allowed recovery periods of 8, 12, 24, 48, 72, 96, 144 and 192 hr in clean water, and the same parameters were evaluated. Muscle glycogen content decreased significantly during the exposure time, while blood glucose levels increased markedly. Gill, muscle and blood lactate values increased during pesticide exposure.…

Aquaporin 3 Expression Loss in Urothelial Carcinoma: Association with Tumor Invasion Depth, but not with Grading?

2017

We have previously provided molecular evidence of expression of aquaporin 3 (AQP3) in normal human urothelium and in UBC of various stages. Whereas former studies demonstrated that loss of AQP3 was associated with invasive and high-grade disease and worse progression-free and cancer-specific survival, this report investigates the expression of AQP3 in associated CIS. Contrary to what we had expected, all CIS specimens were shown to exhibit strong AQP3 expression, suggesting loss of AQP3 in UBC is primarily associated with the ability of tumor cells for invasion but not with grading as sign of dedifferentiation.

Electrochemical characterization of iron sites in ex-framework FeZSM-5

2002

Abstract The electrochemical response of FeZSM-5 prepared by an ex-framework method has been studied using Paraloid B72 polymer film electrodes immersed in aqueous media using H2SO4, HCl, Na2EDTA and NaCl electrolytes. The ex-framework method comprises the hydrothermal synthesis of isomorphously substituted FeZSM-5, followed by calcination at 823 K and subsequent steam treatment (300 mbar H2O in N2) at 873 K. During this process iron is extracted to extra-framework positions. Also partial dealumination of the zeolite framework takes place. Characteristic voltammetric responses in the +1.0 to −0.6 V versus SCE potential range have been recorded and were used to characterize the iron species …

Chemical and isotopic characterization of Ischia hydrothermal system: an interpretative model of fluids circulation

2009

A Combined Experimental and Theoretical Approach to the Photogeneration of 5,6-Dihydropyrimidin-5-yl Radicals in Nonaqueous Media

2016

The chemical fate of radical intermediates is relevant to understand the biological effects of radiation and to explain formation of DNA lesions. A direct approach to selectively generate the putative reactive intermediates is based on the irradiation of photolabile precursors. But, to date, radical formation and reactivity have only been studied in aqueous media, which do not completely mimic the micro environment provided by the DNA structure and its complexes with proteins. Thus, it is also important to evaluate the photogeneration of nucleoside-based radicals in nonaqueous media. The attention here is focused on the independent generation of 5,6-dihydropyrimidin-5-yl radicals in organic…

Kilohertz and Low-Frequency Electrical Stimulation With the Same Pulse Duration Have Similar Efficiency for Inducing Isometric Knee Extension Torque …

2017

International audience; Objective To test the hypotheses that, as compared with pulsed current with the same pulse duration, kilohertz frequency alternating current would not differ in terms of evoked-torque production and perceived discomfort, and as a result, it would show the same current efficiency.Design A repeated-measures design with 4 stimuli presented in random order was used to test 25 women: (1) 500-microsecond pulse duration, (2) 250-microsecond pulse duration, (3) 500-microsecond pulse duration and low carrier frequency (1 kHz), (4) 250-microsecond pulse duration and high carrier frequency (4 kHz). Isometric peak torque of quadriceps muscle was measured using an isokinetic dyna…

Cuticle: Formation, Moulting and Control

1984

The relative rigidity of the arthropod exoskeleton makes it impossible for body size to increase continuously during the postembryonic development of these animals. Once they have hatched from the egg, they grow in steps, passing through a variable number of (larval) stages (Fig. 1 a). Apart from a few exceptions, there are between 3 and 10 such stages in the arachnids, 3–20 in the crustaceans, and 3–10 in the insects. In many cases a metamorphosis stage intervenes (some crustaceans; holometabolous insects) (Fig. 9b, c).

A New Species of Palarus Latreille from Spain with a Comparative Study on Nesting Behavior and Larvae in the Genus (Hymenoptera: Sphecidae)

1992

Palarus almerienis n. sp. is described from Spain (including imago, larva, and nesting habits). P. confusus Turner, currently considered a subspecies of P. ambustus Klug, is raised to full species status. The most important differences among the three species involve sculpture of the mesopleuron. The geographical distribution of these three taxa is discussed. Females of P. almeriensis excavate unicellular nests and capture not only Hymenoptera (the usual prey of the genus), but also Diptera (Stratiomyiidae). They make temporary closures and store the prey in the gallery before transferring it to the cell, which they dig during provisioning. Several species of Diptera (Miltogramminae) are na…