Spinosad is a reduced-risk insecticide with a novel mode of action that provides an alternative to older classes of insecticides such as organophosphates, carbamates and pyrethroids. A comprehensive ecological risk assessment for spinosad use in US cotton crops is presented within a framework of tiered levels of refinement following the guidelines of the US EPA for ecological risk assessments. Toxicity information for a variety of species is documented and utilized, environmental concentrations estimated, and risk characterizations in the form of risk quotients are quantified. Results indicate that spinosad use in cotton does not exceed the most conservative Tier I levels of concern (LOC) values for groundwater, mammals and birds or acute risk to aquatic organisms. Use of very conservative Tier I screening methods resulted in exceeding LOC values for chronic exposure for some aquatic organisms, thus prompting further refinement. When the exposure prediction was refined using less conservative, Tier II mechanistic environmental fate transport models to predict offsite transport and environmental concentrations, chronic risk was not predicted for these species. Spinosad is acutely toxic to bees under laboratory conditions, but toxicity of residue studies and field studies indicate that under actual use conditions the impact on bees is minimal. 相似文献
A three-month-old female Rottweiler puppy was referred for intravascular correction of a previously identified cor triatriatum dexter. Echocardiography confirmed the presence of a hyperechoic membrane that divided the right atrium into a cranial and caudal chamber. A foramen in this membrane allowed the blood to flow from the caudal to the cranial chamber. Balloon dilation of the defect under transthoracic echocardiographic guidance was scheduled for the following day. The dog was premedicated with 0.5 μg/kg sufentanil and 0.2 mg/kg midazolam administered intravenously. General anaesthesia was induced with 2 mg/kg propofol and maintained with inhaled isoflurane in oxygen; at the same time, a constant rate infusion of 0.5 μg/kg/h sufentanil was administered by means of an infusion pump. Uneventful ventricular and supraventricular tachyarrhythmias developed during the placement of catheters and balloon dilation. At the end of procedure, when the guide wire and balloon catheter were removed, normal sinus rhythm was observed. To the authors’ knowledge, no previous reports have described the anaesthetic management of a balloon dilation procedure for cor triatriatum dexter in dogs. 相似文献
The aim of this study was to evaluate the effects of a recruiting maneuver (RM) on lung aeration, gas exchange, and respiratory mechanics during general anesthesia in mechanically ventilated dogs. A thoracic computed tomography (CT) scan, an arterial blood sample, and measurement of respiratory mechanics were performed 10 min before (baseline) and both 5 and 30 min after a vital capacity RM in 10 dogs under general anesthesia. The RM was performed by inflating the lung at 40 cm H2O for 20 s. Lung aeration was estimated by analyzing the radiographic attenuation of the CT images. Lung aeration and gas exchange improved significantly 5 min after the RM compared to baseline and returned to values similar to baseline by 30 min. Static lung compliance was not significantly affected by the RM. An RM induces a temporary improvement in lung function in healthy dogs under general anesthesia.
Reduction of acids to molecular hydrogen as a means of storing energy is catalyzed by platinum, but its low abundance and high cost are problematic. Precisely controlled delivery of protons is critical in hydrogenase enzymes in nature that catalyze hydrogen (H(2)) production using earth-abundant metals (iron and nickel). Here, we report that a synthetic nickel complex, [Ni(P(Ph)(2)N(Ph))(2)](BF(4))(2), (P(Ph)(2)N(Ph) = 1,3,6-triphenyl-1-aza-3,6-diphosphacycloheptane), catalyzes the production of H(2) using protonated dimethylformamide as the proton source, with turnover frequencies of 33,000 per second (s(-1)) in dry acetonitrile and 106,000 s(-1) in the presence of 1.2 M of water, at a potential of -1.13 volt (versus the ferrocenium/ferrocene couple). The mechanistic implications of these remarkably fast catalysts point to a key role of pendant amines that function as proton relays. 相似文献
The safe recycling of organic wastes such as the nutrients obtained from agriculture activities is a relevant aspect of the “One Health” strategy, a worldwide initiative including all aspects of health care for humans and animals, as well as aspects related to the conservation and development of the environment. It represents an important opportunity to mitigate the potential impact of microbial pathogens likely present in nutrient natural sources, as digestate, when applied to land as fertilizers. The objectives of the current study were to determine the inactivation of enteric microorganisms in swine digestate (effluent and sludge) during storage in anaerobic conditions and at different ambient temperatures of tropical zones (16, 22, and 37 °C). Human adenovirus 2 (HAdV-2), bacteriophage PhiX-174, and Salmonella enterica serovar typhimurium (S. typhimurium) were used as enteric microbial models to determine the minimum storage time required to reduce at least 3log of enteric microorganisms load in both matrices at the mentioned temperatures. The minimum storage time required for S. typhimurium was shorter than those observed for viruses at 37 °C, while reduction of at least 3log for S. typhimurium was observed after just 1 day; 20 and 90 days were needed for similar reductions for HAdV-2 and PhiX-174, respectively. Similar results were also observed at lower temperatures: 30 and 45 days were needed for S. typhimurium at 22 and 16 °C, respectively, but 30 and 90 days were needed at 22 °C for HAdV-2 PhiX-174, respectively, or 90 and 120 days at 16 °C for HAdV-2 PhiX-174, respectively. This is a pioneering study on the evaluation of inactivation of enteric viruses in swine digestate in usual tropical ambient temperatures; it demonstrates that the time for a considerable inactivation is longer than that observed for a enteric microorganisms (S. typhimurium), and shows that the storage of swine digestate at the referred temperatures can be used as a low-cost post-treatment to inactivate enteric microorganisms, allowing a further use as safer fertilizer. 相似文献