27 research outputs found
A High Throughput Method for Measuring Polycyclic Aromatic Hydrocarbons in Seafood Using QuEChERS Extraction and SBSE
National Oceanic and Atmospheric Administration (NOAA) Method NMFS-NWFSC-59 2004 is currently used to quantitatively analyze seafood for polycyclic aromatic hydrocarbon (PAH) contamination, especially following events such as the Deepwater Horizon oil rig explosion that released millions of barrels of crude oil into the Gulf of Mexico. This method has limited throughput capacity; hence, alternative methods are necessary to meet analytical demands after such events. Stir bar sorptive extraction (SBSE) is an effective technique to extract trace PAHs in water and the quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction strategy effectively extracts PAHs from complex food matrices. This study uses SBSE to concentrate PAHs and eliminate matrix interference from QuEChERS extracts of seafood, specifically oysters, fish, and shrimp. This method provides acceptable recovery (65â138%) linear calibrations and is sensitive (LOD = 0.02âppb, LOQ = 0.06âppb) while providing higher throughput and maintaining equivalency between NOAA 2004 as determined by analysis of NIST SRM 1974b mussel tissue
A High Throughput Method for Measuring Polycyclic Aromatic Hydrocarbons in Seafood Using QuEChERS Extraction and SBSE
National Oceanic and Atmospheric Administration (NOAA) Method NMFS-NWFSC-59 2004 is currently used to quantitatively analyze seafood for polycyclic aromatic hydrocarbon (PAH) contamination, especially following events such as the Deepwater Horizon oil rig explosion that released millions of barrels of crude oil into the Gulf of Mexico. This method has limited throughput capacity; hence, alternative methods are necessary to meet analytical demands after such events. Stir bar sorptive extraction (SBSE) is an effective technique to extract trace PAHs in water and the quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction strategy effectively extracts PAHs from complex food matrices. This study uses SBSE to concentrate PAHs and eliminate matrix interference from QuEChERS extracts of seafood, specifically oysters, fish, and shrimp. This method provides acceptable recovery (65-138%) linear calibrations and is sensitive (LOD = 0.02 ppb, LOQ = 0.06 ppb) while providing higher throughput and maintaining equivalency between NOAA 2004 as determined by analysis of NIST SRM 1974b mussel tissue
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies,
expounded a compelling and poetic vision for the future of astronomy, calling
for an infrared-optimized space telescope with an aperture of at least .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the James Webb Space Telescope. A
generation of astronomers will celebrate their accomplishments for the life of
the mission, potentially as long as 20 years, and beyond. This report and the
scientific discoveries that follow are extended thank-you notes to the 20,000
team members. The telescope is working perfectly, with much better image
quality than expected. In this and accompanying papers, we give a brief
history, describe the observatory, outline its objectives and current observing
program, and discuss the inventions and people who made it possible. We cite
detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space
Telescope Overview, 29 pages, 4 figure
Marijuana-based Drugs: Innovative Therapeutics or Designer Drugs of Abuse?
Marijuana has been used recreationally and medicinally for centuries. The principle psychoactive component, Î9-tetrahydrocannabinol (Î9-THC), activates CB1 cannabinoid receptors (CB1Rs). CB1R agonists and antagonists could potentially treat a wide variety of diseases; unfortunately, therapeutic doses produce unacceptable psychiatric effects. âK2â or âSpiceâ (K2/Spice), an emerging drug of abuse, exhibits psychotropic actions via CB1R activation. Because of structural dissimilarity to Î9-THC, these drugs are widely unregulated and touted as âlegalâ marijuana. This review summarizes current and future therapeutic uses of CB1R ligands and provides a historical perspective of the K2/Spice âphenomenonâ so the reader can decide if marijuana-based drugs will truly provide innovative therapeutics or instead perpetuate drug abuse
A Major Glucuronidated Metabolite of JWH-018 Is a Neutral Antagonist at CB1 Receptors
Recently, hydroxylated metabolites of JWH-018, a synthetic
cannabinoid
found in many K2/Spice preparations, have been shown to retain affinity
and activity for cannabinoid type 1 receptors (CB1Rs). The activity
of glucuronidated metabolites of JWH-018 is not known; hence, this
study investigated the affinity and activity of a major metabolite,
JWH-018-<i>N</i>-(5-hydroxypentyl) ÎČ-d-glucuronide
(018-gluc), for CB1Rs. The 018-gluc binds CB1Rs (<i>K</i><sub>i</sub> = 922 nM), has no effect on G-protein activity, but
antagonizes JWH-018 activity at CB1Rs. The data suggests that hydroxylation
by cytochrome P450s and subsequent glucuronidation by UDP-glucuronosyltransferases
produces a metabolite, 018-gluc, which possesses antagonistic activity
at CB1Rs
Hemodynamic changes in the kidney in a pediatric rat model of sepsis-induced acute kidney injury
Sepsis is a leading cause of acute kidney injury (AKI) and mortality in children. Understanding the development of pediatric sepsis and its effects on the kidney are critical in uncovering new therapies. The goal of this study was to characterize the development of sepsis-induced AKI in the clinically relevant cecal ligation and puncture (CLP) model of peritonitis in rat pups 17â18 days old. CLP produced severe sepsis demonstrated by time-dependent increase in serum cytokines, NO, markers of multiorgan injury, and renal microcirculatory hypoperfusion. Although blood pressure and heart rate remained unchanged after CLP, renal blood flow (RBF) was decreased 61% by 6 h. Renal microcirculatory analysis showed the number of continuously flowing cortical capillaries decreased significantly from 69 to 48% by 6 h with a 66% decrease in red blood cell velocity and a 57% decline in volumetric flow. The progression of renal microcirculatory hypoperfusion was associated with peritubular capillary leakage and reactive nitrogen species generation. Sham adults had higher mean arterial pressure (118 vs. 69 mmHg), RBF (4.2 vs. 1.1 ml·minâ1·gâ1), and peritubular capillary velocity (78% continuous flowing capillaries vs. 69%) compared with pups. CLP produced a greater decrease in renal microcirculation in pups, supporting the notion that adult models may not be the most appropriate for studying pediatric sepsis-induced AKI. Lower RBF and reduced peritubular capillary perfusion in the pup suggest the pediatric kidney may be more susceptible to AKI than would be predicted using adults models