3,235 research outputs found
Rapid Screening and Quantification of Synthetic Cannabinoids in DART-MS and NMR Spectroscopy
The usage of herbal incenses intentionally doped with synthetic cannabinoids has caused an increase in medical incidents and has triggered legislation to ban these products throughout the world. Law enforcement agencies are experiencing sample backlogs due to the variety of the products and the addition of new and still-legal compounds. In our study, proton Nuclear Magnetic Resonance spectroscopy (NMR) was employed to promptly identify the synthetic cannabinoids after their rapid, direct detection on the herbs and in the powders by Direct Analysis in Real Time-Mass Spectrometry (DART-MS). Compared to conventional lengthy pre-NMR sample clean-up and purification, a simple sample preparation protocol was employed on 50 mg of herbal product samples for quick NMR detection. The combined DART-MS and NMR methods can be used to quickly screen synthetic cannabinoids in powder and herbal samples. Subsequently rapid quantification of cannabinoids can be achieved with short proton-NMR scans when an internal standard, maleic acid, is employed
Roads as nitrogen deposition hot spots
Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Biogeochemistry 114 (2013): 149-163, doi:10.1007/s10533-013-9847-z.Mobile sources are the single largest source of nitrogen emissions to the atmosphere in
the US. It is likely that a portion of mobile-source emissions are deposited adjacent to roads and
thus not measured by traditional monitoring networks, which were designed to measure longterm
and regional trends in deposition well away from emission sources. To estimate the
magnitude of near-source nitrogen deposition, we measured concentrations of both dissolved
inorganic nitrogen (DIN) and total (inorganic + organic) dissolved nitrogen (TDN) in throughfall
(i.e., the nitrogen that comes through the forest canopy) along transects perpendicular to two
moderately trafficked roads on Cape Cod in Falmouth MA, coupled with measurements of both
DIN and TDN in bulk precipitation made in adjacent open fields at the same transect distances.
We used the TDN throughfall data to estimate total nitrogen deposition, including dry gaseous
nitrogen deposition in addition to wet deposition and dry particle deposition. There was no
difference in TDN in the bulk collectors along the transects at either site; however TDN in the
throughfall collectors was always higher closest to the road and decreased with distance. These
patterns were driven primarily by differences in the inorganic N and not the organic N. Annual throughfall deposition was 8.7 (+0.4) and 6.8 (+0.5) TDN - kg N ha-1 yr-1 at sites 10 m and 150 m
away from the road respectively. We also characterized throughfall away from a non-road edge
(power line right-of-way) to test whether the increased deposition observed near road edges was
due to deposition near emission sources or due to a physical, edge effect causing higher
deposition. The increased deposition we observed near roads was due to increases in inorganic N
especially NH4
+. This increased deposition was not the result of an edge effect; rather it is due to
near source deposition of mobile source emissions. We scaled these results to the entire
watershed and estimate that by not taking into account the effects of increased gaseous N
deposition from mobile sources we are underestimating the amount of N deposition to the
watershed by 13% - 25%.This research was supported by Woods Hole SeaGrant (grant NA06OAR4170021), NSF
IGERT (grant DGE 0221658), an Edna Bailey Sussman Environmental Internship Award from
Cornell University, and a Mellon Foundation award though Cornell University.2014-04-1
Informing Practice through Collaborative Partnerships
This paper focuses on students and their teacher engaging in authentic tasks and materials couched in problem-oriented formats within meaningful learning contexts that foster thinking and learning. Authentic in that students construct meaning from real data and are asked to make sense of the world around them. Students pursue individual paths of inquiry using critical and imaginative thinking, and engage in social and solitary contexts that involve them in writing, intervening, and reflecting on ideas gleaned from conversations and readings (electronic and conventional) with a university educator and NASA science educator. The process engages students in formal skills such as written communication, literacy, logic, and calculation using an innovative electronic interactive network. Evaluations of timed writings, concept maps, and Vee diagrams are presente
Rapid Identification of Synthetic Cannabinoids in Herbal Incenses with DART-MS and NMR
The usage of herbal incenses containing synthetic cannabinoids has caused an increase in medical incidents and triggered legislations to ban these products throughout the world. Law enforcement agencies are experiencing sample backlogs due to the variety of the products and the addition of new and still-legal compounds. In our study, proton nuclear magnetic resonance (NMR) spectroscopy was employed to promptly screen the synthetic cannabinoids after their rapid, direct detection on the herbs and in the powders by direct analysis in real time mass spectrometry (DART-MS). A simple sample preparation protocol was employed on 50 mg of herbal sample matrices for quick NMR detection. Ten synthetic cannabinoids were discovered in fifteen herbal incenses. The combined DART-MS and NMR methods can be used to quickly screen synthetic cannabinoids in powder and herbal samples, serving as a complementary approach to conventional GC-MS or LC-MS methods
Combined TRPC3 and TRPC6 blockade by selective small-molecule or genetic deletion inhibits pathological cardiac hypertrophy
Chronic neurohormonal and mechanical stresses are central fea-tures of heart disease. Increasing evidence supports a role forthe transient receptor potential canonical channels TRPC3 andTRPC6 in this pathophysiology. Channel expression for both is nor-mally very low but is increased by cardiac disease, and geneticgain- or loss-of-function studies support contributions to hypertro-phy and dysfunction. Selective small-molecule inhibitors remainscarce, and none target both channels, which may be useful giventhe high homology among them and evidence of redundant sig-naling. Here we tested selective TRPC3/6 antagonists (GSK2332255Band GSK2833503A; IC50,3–21 nM against TRPC3 and TRPC6) andfound dose-dependent blockade of cell hypertrophy signaling trig-gered by angiotensin II or endothelin-1 in HEK293T cells as well as inneonatal and adult cardiac myocytes. In vivo efficacy in mice andrats was greatly limited by rapid metabolism and high protein bind-ing, although antifibrotic effects with pressure overload were ob-served. Intriguingly, although gene deletion of TRPC3 or TRPC6alone did not protect against hypertrophy or dysfunction frompressure overload, combined deletion was protective, support-ing the value of dual inhibition. Further development of thispharmaceutical class may yield a useful therapeutic agent forheart disease management.Fil: Seo, Kinya. Johns Hopkins Medical Institutions. Department of Medicine; Estados UnidosFil: Rainer, Peter P.. Johns Hopkins Medical Institutions. Department of Medicine; Estados Unidos. Medical University of Graz. Department of Medicine; AustriaFil: Shalkey Hahn, Virginia. Johns Hopkins Medical Institutions. Department of Medicine; Estados UnidosFil: Lee, Dong-ik. Johns Hopkins Medical Institutions. Department of Medicine; Estados UnidosFil: Jo, Su-Hyun. Kangwon National University School of Medicine; Corea del Sur. Johns Hopkins Medical Institutions. Department of Medicine; Estados UnidosFil: Andersen, Asger. Aarhus University Hospital. Department of Cardiology; DinamarcaFil: Liu, Ting. Johns Hopkins Medical Institutions. Department of Medicine; Estados UnidosFil: Xu, Xiaoping. GlaxoSmithKline Heart Failure Discovery Performance Unit; Estados UnidosFil: Willette, Robert N.. GlaxoSmithKline Heart Failure Discovery Performance Unit; Estados UnidosFil: Lepore, John J.. GlaxoSmithKline Heart Failure Discovery Performance Unit; Estados UnidosFil: Marino, Joseph P.. GlaxoSmithKline Heart Failure Discovery Performance Unit; Estados UnidosFil: Birnbaumer, Lutz. ational Institute of Environmental Health Sciences; Estados Unidos. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de Investigaciones BiomĂ©dicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones BiomĂ©dicas; ArgentinaFil: Schnackenberg, Christine G.. GlaxoSmithKline Heart Failure Discovery Performance Unit; Estados UnidosFil: Kass, David A.. Johns Hopkins Medical Institutions. Department of Medicine; Estados Unido
Retinoblastoma protein prevents enteric nervous system defects and intestinal pseudo-obstruction
The retinoblastoma 1 (RB1) tumor suppressor is a critical regulator of cell cycle progression and development. To investigate the role of RB1 in neural crest–derived melanocytes, we bred mice with a floxed Rb1 allele with mice expressing Cre from the tyrosinase (Tyr) promoter. TyrCre(+);Rb1(fl/fl) mice exhibited no melanocyte defects but died unexpectedly early with intestinal obstruction, striking defects in the enteric nervous system (ENS), and abnormal intestinal motility. Cre-induced DNA recombination occurred in all enteric glia and most small bowel myenteric neurons, yet phenotypic effects of Rb1 loss were cell-type specific. Enteric glia were twice as abundant in mutant mice compared with those in control animals, while myenteric neuron number was normal. Most myenteric neurons also appeared normal in size, but NO-producing myenteric neurons developed very large nuclei as a result of DNA replication without cell division (i.e., endoreplication). Parallel studies in vitro found that exogenous NO and Rb1 shRNA increased ENS precursor DNA replication and nuclear size. The large, irregularly shaped nuclei in NO-producing neurons were remarkably similar to those in progeria, an early-onset aging disorder that has been linked to RB1 dysfunction. These findings reveal a role for RB1 in the ENS
Out-of-equilibrium dynamics of photoexcited spin-state concentration waves
International audienceThe spin crossover compound [FeIIH2L2-Me][PF6]2 presents a two-step phase transition. In the intermediate phase, a spin state concentration wave (SSCW) appears resulting from a symmetry breaking (cell doubling) associated with a long-range order of alternating high and low spin molecular states. By combining time-resolved optical and X-ray diffraction measurements on a single crystal, we study how such a system responds to femtosecond laser excitation and we follow in real time the erasing and rewriting of the SSC
A Straight and Narrow Ionized Filament
We report the discovery of a extremely narrow, extremely linear, ionized
filament. The filament is 2.5 degrees long and has an H surface
brightness of 0.5 rayleighs. The filament is approximately ``Y'' shaped. The
widest separation of the two diagonal segments is 5 arcminutes. We discuss four
possible origins for this feature: (1) an extremely low density, nearby jet,
(2) an unusually linear filament associated with some large-scale nearby
nebula, perhaps even the Local Bubble, (3) an ionized trail left by mechanical
input from a star or compact object moving through the ISM, or (4) an ionized
trail left by photoionization (``Fossil \stromgren Trail'') from a star or
compact object. We favor this last hypothesis, and derive some of the basic
properties for an ionized trail. Regardless of whether this latter hypothesis
applies to this specific filament, the basic properties of such a trail, its
length, width, and brightness, are interesting, predictable, and should be
observable behind some white dwarfs. We suggest future tests for ascertaining
the origin of this filament, and discuss how this structure might be useful to
constrain the thermal and velocity structure of the nearby interstellar medium.Comment: 18 pages, 5 figures, to appear in AJ, 2001; astroph abstract is
abridge
Geriatric Conditions and Prescription of Vitamin K Antagonists vs. Direct Oral Anticoagulants Among Older Patients With Atrial Fibrillation: SAGE-AF
Background: Geriatric conditions are common among patients with atrial fibrillation (AF) and relate to complications of oral anticoagulation (OAC).
Objective: To examine the prevalence of geriatric conditions among older patients with AF on OAC and relate type of OAC to geriatric conditions.
Methods: Participants had a diagnosis of AF, were aged \u3e /=65 years, CHA2DS2VASC \u3e /= 2, and had no OAC contraindications. Participants completed a 6-component geriatric assessment that included validated measures of frailty (CHS Frailty Scale), cognitive function (MoCA), social support (MOS), depressive symptoms (PHQ9), vision, and hearing. Type of OAC prescribed was documented in medical records.
Results: 86% of participants were prescribed an OAC. These participants were on average aged 75.7 (SD: 7.1) years, 49% were women, two thirds were frail or pre-frail, and 44% received a DOAC. DOAC users were younger, had lower CHA2DS2VASC and HAS-BLED scores, and were less likely to be frail. In Massachusetts, pre-frailty was associated with a significantly lower odds of DOAC vs. VKA use (OR = 0.64, 95%CI 0.45, 0.91). Pre-frailty (OR = 0.33, 95%CI 0.18-0.59) and social isolation (OR = 0.38, 95%CI 0.14-0.99) were associated with lower odds of DOAC receipt in patients aged 75 years or older. Social isolation was associated with higher odds of DOAC use (OR = 2.13, 95%CI 1.05-4.29) in patients aged 65-74 years.
Conclusions: Geriatric conditions were common and related to type of OAC prescribed, differentially by age group. Research is needed to evaluate whether a geriatric examination can be used clinically to better inform OAC decision-making in older patients with AF
Hard X-ray Emission Associated with White Dwarfs
We have used the WGACAT to search for hard X-ray sources associated with
white dwarfs (WDs) from the catalog of McCook & Sion (1999). We find 17 X-ray
sources coincident with WDs showing significant hard X-ray emission at energies
>0.5 keV. Twelve of these WDs are in known binary systems, in two of which the
accretion of the close companion's material onto the white dwarf produces the
hard X-ray emission, and in the other ten of which the late-type companions'
coronal activity emits hard X-rays. One WD is projected near an AGN which is
responsible for the hard X-ray emission. The remaining four WDs and two
additional white dwarfs with hard X-ray emission appear single. The lack of
near-IR excess from the apparently single WDs suggests that either X-ray
observations are more effective than near-IR photometry in diagnosing faint
companions or a different emission mechanism is needed. It is intriguing that
50% of the six apparently single WDs with hard X-ray emission are among the
hottest WDs. We have compared X-ray properties of 11 hot WDs with different
spectral types, and conclude that stellar pulsation and fast stellar winds are
not likely the origin of the hard X-ray emission, but a leakage of the
high-energy Wien tail of emission from deep in the stellar atmosphere remains a
tantalizing source of hard X-ray emission from hot DO and DQZO WDs. (This
abstract is an abridged version.)Comment: 35 pages, 8 figures, 4 tables, accepted for publication in AJ, April
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