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Introduction: Lower gastrointestinal bleeding (LGIB) frequently leads to emergency department (ED) visits and hospitalizations, encompassing a spectrum of outcomes from spontaneous resolution to intrahospital mortality. Aim: The purpose of this study was to validate a scoring system designed to identify cases of low‐risk LGIB, allowing for safe discharge from the ED. Methods: A retrospective analysis of all gastrointestinal bleeding cases presented at three EDs in 2020 was conducted, focusing specifically on patients with LGIB. The SHA2PE score incorporates factors such as systolic blood pressure, hemoglobin levels, use of antiplatelet or anticoagulant medications, pulse rate, and episodes of bright blood per rectum. Results: Out of 1112 patients presenting with LGIB to the ED, 55 were hospitalized, 20 required blood transfusions, 15 underwent colonoscopies, one underwent interventional radiology procedures, and two patients died. Employing a SHA2PE score with a cutoff value of 1 yielded a specificity of 78.5% (95% CI (confidence interval) [75.8–81.0]), sensitivity of 76.8% (95% CI [63.6–87.0]), positive predictive value (PPV) of 17.0% (95% CI [12.6–22.2]), and negative predictive value (NPV) of 98.3% (95% CI [97.2–99.1]) for predicting the need for hospitalization and intrahospital intervention. When considering return visits to the ED within 7 days with the same presentation, the score demonstrated a specificity of 78.8% (95% CI [76.0–81.3]), sensitivity of 68.6% (95% CI [56.4–79.1]), PPV of 19% (95% CI [14.3–24.4]), and NPV of 97.2% (95% CI [95.8–98.2]). Conclusions: The SHA2PE score demonstrates potential in predicting cases of low‐risk LGIB, offering a high NPV for hospitalization, the need for intrahospital intervention, and return visits to the ED. However, these findings should be interpreted cautiously given the low prevalence of interventions and limitations in the study's population and design. [ABSTRACT FROM AUTHOR]

Degradation of the fungicide benzovindiflupyr was slow in standard regulatory laboratory studies in soil and aquatic systems, suggesting it is a persistent molecule. However, the conditions in these studies differed significantly from actual environmental conditions, particularly the exclusion of light, which prevents potential contributions from the phototrophic microorganisms that are ubiquitous in both aquatic and terrestrial environments. Higher tier laboratory studies that include a more comprehensive range of degradation processes can more accurately describe environmental fate under field conditions. Indirect aqueous photolysis studies with benzovindiflupyr showed that the photolytic half‐life in natural surface water can be as short as 10 days, compared with 94 days in pure buffered water. Inclusion of a light–dark cycle in higher tier aquatic metabolism studies, to include the contribution of phototrophic organisms, reduced the total system half‐life from >1 year in dark test systems to as little as 23 days. The relevance of these additional processes was confirmed in an outdoor aquatic microcosm study in which the half‐life of benzovindiflupyr was 13–58 days. In laboratory soil degradation studies, the degradation rate of benzovindiflupyr was significantly faster in cores with an undisturbed surface microbiotic crust, incubated in a light–dark cycle (half‐life of 35 days), than in regulatory studies with sieved soil in the dark (half‐life >1 year). A radiolabeled field study validated these observations, showing residue decline with a half‐life of approximately 25 days over the initial 4 weeks. Conceptual models of environmental fate based on standard regulatory studies may be incomplete, and additional higher tier laboratory studies can be valuable in elucidating degradation processes and improving the prediction of persistence under actual use conditions. Environ Toxicol Chem 2023;42:995–1009. © 2023 SETAC [ABSTRACT FROM AUTHOR]

Degradation of agrochemicals in soil is frequently faster under field conditions than in laboratory studies. Field studies are carried out on relatively undisturbed soil, whereas laboratory studies typically use sieved soil, which can have a significant impact on the physical and microbial nature of the soil and may contribute to differences in degradation between laboratory and field studies. A laboratory study was therefore conducted to determine the importance of soil structure and variable soil moisture on the degradation of 2 fungicides (azoxystrobin and paclobutrazol) that show significant differences between laboratory and field degradation rates in regulatory studies. Degradation rates were measured in undisturbed cores of a sandy clay loam soil (under constant or variable moisture contents) and in sieved soil. For azoxystrobin, degradation rates under all conditions were similar (median degradation time [DegT50] 34–37 d). However, for paclobutrazol, degradation was significantly faster in undisturbed cores (DegT50 255 d in sieved soil and 63 d in undisturbed cores). Varying the moisture content did not further enhance degradation of either fungicide. Further examination into the impact of soil structure on paclobutrazol degradation, comparing undisturbed and sieved/repacked cores, revealed that the impact of sieving could not be mitigated by repacking the soil to a realistic bulk density. Examination of fungal and bacterial community structure using automated ribosomal spacer analysis showed significant initial differences between sieved/repacked and intact soil cores, although such differences were reduced at the end of the study (70 d). The present study demonstrates that disruption of soil structure significantly impacts microbial community structure, and for some compounds this may explain the differences between laboratory and field degradation rates. Environ Toxicol Chem 2021;40:2715–2725. © 2021 SETAC [ABSTRACT FROM AUTHOR]

Lysimeter studies can be used to identify and quantify soil degradates of agrochemicals (metabolites) that have the potential to leach to groundwater. However, the apparent metabolic profile of such lysimeter leachate samples will often be significantly more complex than would be expected in true groundwater samples. This is particularly true for S-metolachlor, which has an extremely complex metabolic pathway. Consequently, it was not practically possible to apply a conventional analytical approach to identify all metabolites in an S-metolachlor lysimeter study, because there was insufficient mass to enable the use of techniques such as nuclear magnetic resonance. Recent advances in high-resolution accurate mass spectrometry, however, allow innovative screening approaches to characterize leachate samples to a greater extent than previously possible. Leachate from the S-metolachlor study was screened for accurate masses (±5 ppm of the nominal mass) corresponding to more than 400 hypothetical metabolite structures. A refined list of plausible metabolites was constructed from these data to provide a comprehensive description of the most likely metabolites present. The properties of these metabolites were then evaluated using a principal component analysis model, based on molecular descriptors, to visualize the entire chemical space and to cluster the metabolites into a number of subclasses. This characterization and principal component analysis evaluation enabled the selection of suitable representative metabolites that were subsequently used as exemplars to assess the toxicological relevance of the leachate as a whole. Environ Toxicol Chem 2016;35:1401-1412. © 2015 SETAC [ABSTRACT FROM AUTHOR]

We have identified the promoter/operator region of the zntA gene of Escherichia coli and shown that Zn(II) is the primary inducer of expression of this Zn(II)/Cd(II) export gene. The promoter PzntA shows sequence similarities to the promoters of mercury resistance (mer ) operons, including a long spacer region containing an inverted repeat sequence. The gene encoding the transcriptional regulator of PzntA , designated zntR , has been identified from genome sequence data, by expression of the gene product and by insertional inactivation/complementation. The ZntR product is a member of the MerR family of transcriptional regulators and appears to act as a hypersensitive transcriptional switch. A hybrid MerR/ZntR protein has been constructed and indicates that the C-terminal region of ZntR recognizes Zn(II). [ABSTRACT FROM AUTHOR]