Acute Toxicity of Fungicide-Insecticide-Adjuvant Combinations Applied to Almonds During Bloom on Adult Honey Bees.

Beekeepers report significant honey bee deaths during and after almond bloom. These losses pose a major problem for the California almond industry because of its dependence on honey bees as pollinators. The present study aimed to determine if combinations of pesticides applied during almond bloom during daylight hours were a possible explanation for these losses. In this study we aimed to mimic the spray application route of exposure to pesticides using a Potter Spray Tower to treat adult honey bees with commonly encountered pesticides and pesticide combinations at multiples of the maximum recommended field application rates. Tested insecticides included Altacor® and Intrepid®, and tested fungicides included Tilt®, Pristine®, Luna Sensation®, and Vangard®. Synergistic toxicity was observed when the fungicide Tilt (active ingredient propiconazole) was applied with the insecticide Altacor (chlorantraniliprole), though neither caused significant mortality when applied independently. The study also looked at the effect of adding a spray adjuvant, Dyne-Amic®, to pesticide mixtures. Dyne-Amic was toxic to honey bees at concentrations above the maximum recommended field application rate, and toxicity was increased when combined with the fungicide Pristine (pyraclostrobin and boscalid). Addition of Dyne-Amic also increased toxicity of the Tilt and Altacor combination. These results suggest that application of Altacor and Tilt in combination with an adjuvant at the recommended field application rates could cause mortality in adult honey bees. These findings highlight a potential explanation for honey bee losses around almond bloom, emphasize that the safety of spray adjuvants to bees should not be assumed, and provide support for recommendations to protect bees from pesticides through application at night when bees are not foraging. Environ Toxicol Chem 2022;41:1042-1053. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

An in vitro model for preclinical testing of thrombogenicity of resorbable metallic stents.

Vascular stents that can biodegrade and disappear in time have been reported as a promising solution to the problems of late-stent thrombosis and in-stent restenosis. Iron alloys in particular have many advantages in terms of cytocompatibility and mechanical properties. Despite mechanical behavior and biocompatibility studies, little attention has been given to the thrombogenic potential of these stents. This article presents the first study that aims to close this gap by addressing the hemocompatibility of resorbable iron-based alloys and composites in an in vitro porcine blood model. The investigated braided biodegradable stents included 99.95% pure Fe (50% cold worked), Fe35Mn alloy, Fe35Mn-25% ZM21 (ZM21 is 2% Zn, 0.5% Mn, balance Mg), Fe-25% Mg, and Fe-57% Mg. All stents were formed by braiding 127 µm diameter wires into stents with an outer diameter of 6.35 mm. Inflammatory reaction and thrombocyte activation were examined by assessment of ß-thromboglobulin, thrombin-antithrombin complex, and polymorphonuclear elastase levels. The potential of Fe35Mn for use in vascular stenting is demonstrated by its exhibition of the least thrombogenic potential among tested materials. All bioresorbable Fe-Mn alloy compositions showed a reduced propensity towards platelet adhesion compared to 316L stainless steel, further indicating a general positive shift towards reduced thrombogenicity compared to traditional stents.