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Current research on prothioconazole (PTC), a broad-spectrum triazole fungicide, mainly focuses on its efficacy and residues; only a few studies have been assessing its toxicological effects. Using acute and chronic toxicity tests, we assessed the effects of PTC and its metabolite prothioconazole-desthio (PTCd) on the inhibition of the activity, growth, and reproduction of Daphnia magna. A dose–response relationship was established to determine sensitive biological indicators. In the acute and chronic toxicity tests, the 48-h EC50 (concentration for 50% of the maximal effect) of PTC and PTCd for D. magna were 2.82 and 5.19 mg/L and 0.0807 and 0.132 mg/L, respectively; in the latter test, PTC was 1.64 times more toxic than PTCd. Acute-to-chronic toxicity ratios were calculated using chronic toxicity data; the ratios were 227 and 27.5 for PTC and PTCd, respectively. Our results indicate that both PTC and PTCd affect the growth and reproduction of D. magna and that the toxicity of PTC is greater than that of PTCd. In conclusion, the metabolites of PTD are toxic to D. magna at certain concentrations, and their environmental risks should not be neglected. [ABSTRACT FROM AUTHOR]

The residue levels and risk assessment of imidacloprid (IMI) and chlorantraniliprole (CAP) in celery grown under open field and greenhouse cultivation were investigated. Both pesticides were used through foliar application and soil drench application at the recommended dose (RD) and 10-fold recommended dose (10RD). The half-lives of IMI and CAP in celery were 1.9 to 5.8 days and 4.3 to 6.5 days after foliar application, respectively, and the dietary risk quotients of IMI and CAP were 14.8 to 18.3% and 1.0 to 1.2%, respectively. For soil drench application, the half-lives of IMI and CAP in soil were 17.5 to 28.5 days and 15.1 to 23.7 days, respectively. Celery plants were able to absorb both insecticides from the soil. The highest concentrations of IMI in celery plants were 0.12 to 0.24 mg kg−1 (RD) and 0.34 to 0.39 mg kg−1 (10RD), and those for CAP were 0.0081 to 0.015 mg kg−1 (RD) and 0.028 to 0.057 mg kg−1 (10RD). Based on the highest residues of IMI and CAP in celery, the dietary risk quotients of IMI and CAP were 15.0% (RD) to 15.6% (10RD) and 1.0% (RD and 10RD) after soil drench application, respectively. The observed bioconcentration factors were 1.38 to 2.11 (IMI) and 0.35 to 0.48 (CAP), indicating that celery accumulated IMI more easily than CAP. The foliar and soil applications of IMI and CAP in celery at the RD and 10RD do not pose a safety risk to consumers. [ABSTRACT FROM AUTHOR]

A method for performing simultaneous measurements of the electrical resistivity and the Seebeck coefficient at high pressure and high temperature (HPHT) in cubic multi-anvil apparatus is described. For high pressure and high temperature measurements, a four-probe arrangement is used to measure the electrical resistivity and two pairs of chromel-alumel type thermocouples are employed to determine the Seebeck coefficient, respectively. Results of an expected temperature-induced phase transition, pressure-induced metallization and enhancement of the thermoelectric properties were obtained in Ag2Te. This method can provide the necessary data of thermoelectric materials at HPHT. [ABSTRACT FROM AUTHOR]

The parasitoid Trichogramma confusum Viggiani (Hymenoptera: Trichogrammatidae) is an important natural enemy of many lepidopterans throughout the world. Extensive toxicological tests have clarified the toxic effects of insecticides on trichogrammatids, but only few studies have examined these effects on T. confusum. Among the seven classes of tested chemicals, organophosphates and carbamates exhibited the highest intrinsic toxicity to the parasitoid with LC50 values ranging from 0.037 (0.030-0.046) to 0.29 (0.23-0.38) and from 0.17 (0.15-0.19) to 1.61 (1.45-1.79) mg AI L-1 respectively. They were followed by phenylpyrazoles, avermectins, pyrethroids, and neonicotinoids, which induced variable toxicity responses with LC50 values ranging from 0.63 to 45.26, 1.06-21.73, 3.89-19.36, and 0.24-754.2 mg AI LT-1, respectively. In contrast, insect growth regulators (IGRs) showed the least toxicity to the parasitoid with LC50 values ranging from 3,907 (3,432- 4,531) to 10,154 (8,857-12,143) mg AI LT-1. A risk quotient analysis indicated that neonicotinoids (except thiamethoxam), avermectins, pyrethroids, IGRs, and phenylpyrazoles are safe, but organophosphates and carbamates are slightly to moderately or dangerously toxic to T. confusum. This study provides informative data for implementing both biological and chemical control strategies in integrated pest management of lepidopterans. [ABSTRACT FROM AUTHOR]

Both chemical and biological methods are essential for control of insects, for example, lepidopterans, on rice. Thus, it is important to know the effect of chemicals on the biological control agents. In this study, we assessed the toxicity of commonly used insecticides on a biological control agent, Trichogramma japonicum Ahmead (an egg parasitoid of rice lepidopterans) by using a dry film residue method. Results showed that thirty insecticides from seven chemical classes exhibited various degree of toxicity to this parasitoid. Among the seven classes of chemicals tested, organophosphates (chlorpyrifos, fenitrothion, phoxim, profenofos, and triazophos) and carbamates (carbaryl, carbsulfan, isoprocarb, metolcarb, and promecarb) exhibited the highest intrinsic toxicity to T. japponicum, with an LC50 of 0.035 (0.029-0.044) to 0.49 (0.34-0.87) mg active ingredient (a.i.) L-1, followed by antibiotics (abamectin, emamectin benzoate, and ivermectin), phenylpyrazoles (butane-fipronil, ethiprole, and fipronil), pyrethroids (cyhalthrin, cypermethrin, fenpropathrin, and lambda-cyhaothrin), and neonicotinoids (acetamiprid, imidacloprid, imidaclothiz, nitenpyram, thiacloprid, and thiamethoxam). Moreover, the insect growth regulator insecticides (chlorfluazuron, fufenozide, hexaflumuron and tebufenozide) exhibited the lowest toxicity to the wasps with an LC50 of 3,383 (2406-5499) to 30206 (23107-41008) mg a.i. L-1. Risk quotient analysis showed that phenylpyrazoles, pyrethroids, insect growth regulators, neonicotinoids (with the exception of thiamethoxam), and antibiotics (with the exception of abamectin) are classified as safe agents to the parasitoid, while organophosphates and carbamates are classified as slightly, moderately, or highly toxic agents to the parasitoid. The data presented in this paper provided useful information on the selection of compatible insecticides with T. japonicum. [ABSTRACT FROM AUTHOR]

The structure and the magnetic properties of silica-coated cobalt ferrite nanoparticles (80 wt% CoFe2O4), prepared by sol–gel method and submitted to thermal treatments in the range 800–1,000 °C, were investigated through XRD, FT-IR, TEM and VSM. The effects of thermal treatment temperatures on the structure and magnetic properties of nanoparticles were examined. A silica shell thickness of about 5 nm was synthesized on top of cobalt ferrite nanoparticles. The non-crystalline silica confines the growth of cobalt ferrite nanoparticles, i.e., the particle sizes are almost independent of the thermal treatment. Saturation magnetization (Ms) was decreased slightly and coercivity (Hc) was increased, when the non-crystalline silica was coated on the surface of cobalt ferrite nanoparticles. [ABSTRACT FROM AUTHOR]

The effect of Fe3+ ions substitutions by rare-earth ions on magnetic properties of nanocrystalline Ni–Mn ferrite prepared by emulsion method was investigated. X-ray diffraction pattern indicated the presence of cubic structure of spinel ferrite. The crystallite sizes increased with an increase in the heat treatment temperatures, while it decreased for the substitution of rare-earth ions. The magnetic properties were changed with types of rare-earth ions and heat treatment temperatures. Room temperature Mössbauer spectra can differentiate between superparamagnetism and ferrimagnetism in nature. [ABSTRACT FROM AUTHOR]