Flexible covalent-organic frameworks (COFs) display a variety of guest-dependent dynamic behaviors, but because these are an emerging class of materials, very little experimental adsorption data exists. This work examines the adsorption properties of COF-506 and COF-506-Cu utilizing various adsorbates as probe molecules. These materials have small surface areas (<100 m/g) but still have significant capacity for methanol and isopropanol compared to activated carbon, even though the COF contains approximately 1/10th the surface area of many activated carbons.
View Article and Find Full Text PDFThis study examined the impact of a hypercaloric high-fat high-fructose diet (HFFD) in dogs as a potential model for human impaired glucose tolerance (IGT) and type 2 diabetes mellitus (T2DM). The HFFD not only led to weight gain but also triggered metabolic alterations akin to the precursors of human T2DM, notably insulin resistance and β-cell dysfunction. Following the HFFD intervention, the dogs exhibited a 50% decrease in insulin sensitivity within the first four weeks, paralleling observations in the progression from normal to IGT in humans.
View Article and Find Full Text PDFEndogenous insulin secretion is a key regulator of postprandial hepatic glucose metabolism, but this process is dysregulated in diabetes. Subcutaneous insulin delivery alters normal insulin distribution, causing relative hepatic insulin deficiency and peripheral hyperinsulinemia, a major risk factor for metabolic disease. Our aim was to determine whether insulin's direct effect on the liver is preeminent even when insulin is given into a peripheral vein.
View Article and Find Full Text PDFAims: We previously quantified the hypoglycaemia-sparing effect of portal vs peripheral human insulin delivery. The current investigation aimed to determine whether a bioequivalent peripheral vein infusion of a hepatopreferential insulin analog, insulin-406, could similarly protect against hypoglycaemia.
Materials And Methods: Dogs received human insulin infusions into either the hepatic portal vein (PoHI, n = 7) or a peripheral vein (PeHI, n = 7) for 180 minutes at four-fold the basal secretion rate (6.
A comprehensive investigation of the Pacific cicada killer, Sphecius convallis Patton, was undertaken to examine the behavioral and physiological mechanisms by which they are able to complete their life cycle in the thermal extremes of the Upper Sonoran Desert. S. convallis were endothermic, exhibiting elevated and relatively constant thorax temperatures during many activities.
View Article and Find Full Text PDFHypoglycemia limits optimal glycemic control in type 1 diabetes mellitus (T1DM), making novel strategies to mitigate it desirable. We hypothesized that portal (Po) vein insulin delivery would lessen hypoglycemia. In the conscious dog, insulin was infused into the hepatic Po vein or a peripheral (Pe) vein at a rate four times of basal.
View Article and Find Full Text PDFThis study evaluated foraging effectiveness of Pacific cicada killers (Sphecius convallis) by comparing observed prey loads to that predicted by an optimality model. Female S. convallis preyed exclusively on the cicada Tibicen parallelus, resulting in a mean loaded flight muscle ratio (FMR) of 0.
View Article and Find Full Text PDFWe examined the role of vagus nerves in the transmission of the portal glucose signal in conscious dogs. At time 0, somatostatin infusion was started along with intraportal insulin and glucagon at 4-fold basal and basal rates, respectively. Glucose was infused via a peripheral vein to create hyperglycemia ( approximately 2 fold basal).
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