Building a Conceptual Model for the Environmental Fate of the Fungicide Benzovindiflupyr.

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.

Clinical effects of ascending colon patching ileorectal heart-shaped anastomosis on total colonic aganglionosis.

OBJECTIVE: We studied the clinical effects of ascending colon patching ileorectal heart-shaped anastomosis in treating total colonic aganglionosis. PATIENTS AND METHODS: From June 2006 to June 2013, 15 children with severe abdominal distension, low small intestine obstruction and intestinal perforation in the neonatal period, were enrolled in this study. In phase I, patients received emergency terminal ileum stoma plus multi-site colonic biopsy and 6 to 12 months later, ascending colon patching ileorectal heart-shaped anastomosis was conducted in phase II. The occurrence of postoperative complications was recorded. Patients' defecation and anal manometry during the follow-up period were monitored and recorded. All operations were successful, and the average hospitalization time was 10.5 days, and the average amount of bleeding was 30 mL. RESULTS: There were 2 cases of enterocolitis, but no intestinal anastomotic leakage, no incision infection, no anal stenosis and no mortality. Postoperative follow-up lasted for 1 to 2 years with an average of 1.2 years. Perianal redness and erosion occurred in an early stage after the operation, but disappeared after 6 months. Postoperative defecation frequency was about 6 to 9 times, but after 2 years this frequency reduced to 2 to 3 times. Feces transformed from watery into soft forms. Normal results were obtained in the detection of serum K+, Na+, Cl-, HCO3-, hemoglobin, albumin and globulin levels in postoperative follow-up. Rectal rest pressure and anal canal rest pressure after a radical operation on megacolon were significantly lower than those of before operation (p < 0.05). CONCLUSIONS: Ascending colon patching ileorectal heart-shaped anastomosis preserved right hemicolon with relatively good absorptive capability and complied with the physiology of colon. Meanwhile, the ileorectal heart-shaped anastomosis was conducted. The anastomotic stoma was in an oblique heart shape, and its aperture was wide and in different planes without stenosis, blind bag and gate syndrome. We concluded that ascending colon patching ileorectal heart-shaped anastomosis was an effective and feasible method for the radical operation on total colonic aganglionosis.

Renal circulation and microcirculation during intra-abdominal hypertension in a porcine model.

OBJECTIVE: The purpose of the study is to further investigate the effects of increased intra-abdominal pressure (IAP) on renal hemodynamics and renal perfusion, and to evaluate the renal cortical and sublingual microcirculation by sidestream dark field (SDF) imaging, both with a porcine model. MATERIALS AND METHODS: IAP was increased stepwise to 10, 15, 20, 25 mmHg, during which hemodynamic parameters, urinary output, renal contrast-enhanced ultrasound (CEUS), sublingual and renal SDF videos were all recorded from 12 pigs. RESULTS: Wash in time (WT) and time to peak (TTP) prolonged significantly (p<0.05), while peak intensity (PI) wash in slope (WS) and AUC (area under curve) in CEUS declined significantly (p<0.05) compared with baseline when IAP elevated to 25 mm Hg. With an increase of abdominal pressure, sublingual microvascular flow index (MFI) drop significantly, especially upon IAP was over 20 mmHg. But other parameters such as the total vascular density (TVD), De Backer Score, proportion of perfused vessels (PPV), perfused vessel density (PVD), and heterogeneity index (HI) of tongue were not significantly changed. With increasing IAP, renal vascular resistance increased and MFI decreased about 30%. RFG, instead of RFG showed a moderate correlation with AUC (R=0.47, p<0.05) and MFI (R=0.49, p<0.05). CONCLUSIONS: CEUS is a safe, real-time dynamic, noninvasive and simple technique to evaluate renal microvascular perfusion in intra-abdominal hypertension. Descending slope, PI and AUC can be used for the diagnosis of the renal microvascular damage in a porcine model of IAP-induced renal impairment. Also, SDF on the surface of the kidney is a useful tool to evaluate the microcirculation of kidney but sublingual SDF imaging was barely useful.

Quantifying soil surface photolysis under conditions simulating water movement in the field: a new laboratory test design.

Soil surface photolysis can be a significant dissipation pathway for agrochemicals under field conditions, although it is assumed that such degradation ceases once the agrochemical is transported away from the surface following rainfall or irrigation and subsequent drainage of soil porewater. However, as both downward and upward water movements occur under field conditions, relatively mobile compounds may return to the surface, prolonging exposure to ultraviolet light and increasing the potential for degradation by photolysis. To test this hypothesis, a novel experimental system was used to quantify the contribution of photolysis to the overall dissipation of a new herbicide, bicyclopyrone, under conditions that mimicked field studies more closely than the standard laboratory test guidance. Soil cores were taken from 3 US field study sites, and the surfaces were treated with [(14) C]-bicyclopyrone. The radioactivity was redistributed throughout the cores using a simulated rainfall event, following which the cores were incubated under a xenon-arc lamp with continuous provision of moisture from below and a wind simulator to induce evaporation. After only 2 d, most of the test compound had returned to the soil surface. Significantly more degradation was observed in the irradiated samples than in a parallel dark control sample. Degradation rates were very similar to those observed in both the thin layer photolysis study and the field dissipation studies and significantly faster than in the soil metabolism studies conducted in the dark. Thus, for highly soluble, mobile agrochemicals, such as bicyclopyrone, photolysis is not terminated permanently by rainfall or irrigation but can resume following transport to the surface in evaporating water.

[The normalization creep functions of C5.6,T6.7,L4.5 interverbral discs of human vertebral column].

In this paper are reported the creep experimental studies on 9 fresh C5.6 intervertebral discs,9 fresh T6.7 intervertebral discs and 10 L4.5 intervertebral discs that were taken from the bodies of ten men(aged 19-35 years) who had died of head injury 1-4 h before. By simulating the temperature of human body (36.5 degrees C +/- 0.5 degree C) and putting 300 N load on the discs, we measured the intervertebral creep effects and obtained the strain-time curves.