790 research outputs found

    Isolated X-ray -- infrared sources in the region of interaction of the supernova remnant IC 443 with a molecular cloud

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    The nature of the extended hard X-ray source XMMU J061804.3+222732 and its surroundings is investigated using XMM-Newton, Chandra, and Spitzer observations. This source is located in an interaction region of the IC 443 supernova remnant with a neighboring molecular cloud. The X-ray emission consists of a number of bright clumps embedded in an extended structured non-thermal X-ray nebula larger than 30" in size. Some clumps show evidence for line emission at ~1.9 keV and ~3.7 keV at the 99% confidence level. Large-scale diffuse radio emission of IC 443 passes over the source region, with an enhancement near the source. An IR source of about 14" x 7" size is prominent in the 24 um, 70 um, and 2.2 um bands, adjacent to a putative Si K-shell X-ray line emission region. The observed IR/X-ray morphology and spectra are consistent with those expected for J/C-type shocks of different velocities driven by fragmented supernova ejecta colliding with the dense medium of a molecular cloud. The IR emission of the source detected by Spitzer can be attributed to both continuum emission from an HII region created by the ejecta fragment and line emission excited by shocks. This source region in IC 443 may be an example of a rather numerous population of hard X-ray/IR sources created by supernova explosions in the dense environment of star-forming regions. Alternative Galactic and extragalactic interpretations of the observed source are also discussed.Comment: The Astrophysical Journal, v. 677 (April 2008), in pres

    XMM-Newton observations of the supernova remnant IC443: I. soft X-ray emission from shocked interstellar medium

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    The shocked interstellar medium around IC443 produces strong X-ray emission in the soft energy band (E<1.5 keV). We present an analysis of such emission as observed with the EPIC MOS cameras on board the XMM-Newotn observatory, with the purpose to find clear signatures of the interactions with the interstellar medium (ISM) in the X-ray band, which may complement results obtained in other wavelenghts. We found that the giant molecular cloud mapped in CO emission is located in the foreground and gives an evident signature in the absorption of X-rays. This cloud may have a torus shape and the part of torus interacting with the IC443 shock gives rise to 2MASS-K emission in the southeast. The measured density of emitting X-ray shocked plasma increases toward the northeastern limb, where the remnant is interacting with an atomic cloud. We found an excellent correlation between emission in the 0.3-0.5 keV band and bright optical/radio filament on large spatial scales. The partial shell structure seen in this band therefore traces the encounter with the atomic cloud.Comment: 10 pages, 10 figures, accepted for publication in ApJ (20 September 2006, v649). For hi-res figures, see http://www.astropa.unipa.it/Library/OAPA_preprints/ic443ele1.ps.g

    Preliminary analysis of an extensive one year survey of trace elements and compounds in the suspended particulate matter in Cleveland, Ohio

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    Beginning in 1971 a cooperative program has been carried on by the City of Cleveland Division of Air Pollution Control and NASA Lewis Research Center to study the trace element and compound concentrations in the ambient suspended particulate matter in Cleveland Ohio as a function of source, monitoring location and meteorological conditions. The major objectives were to determine the ambient concentration levels at representative urban sites and to develop a technique using trace element and compound data in conjunction with meteorological conditions to identify specific pollution sources which could be developed into a practical system that could be readily utilized by an enforcement agency

    Comparing Galaxy Morphology at Ultraviolet and Optical Wavelengths

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    We have undertaken an imaging survey of 34 nearby galaxies in far-ultraviolet (FUV, ~1500A) and optical (UBVRI) passbands to characterize galaxy morphology as a function of wavelength. This sample, which includes a range of classical Hubble types from elliptical to irregular with emphasis on spirals at low inclination angle, provides a valuable database for comparison with images of high-z galaxies whose FUV light is redshifted into the optical and near- infrared bands. Ultraviolet data are from the UIT Astro-2 mission. We present images and surface brightness profiles for each galaxy, and we discuss the wavelength-dependence of morphology for different Hubble types in the context of understanding high-z objects. In general, the dominance of young stars in the FUV produces the patchy appearance of a morphological type later than that inferred from optical images. Prominent rings and circumnuclear star formation regions are clearly evident in FUV images of spirals, while bulges, bars, and old, red stellar disks are faint to invisible at these short wavelengths. However, the magnitude of the change in apparent morphology ranges from dramatic in early--type spirals with prominent optical bulges to slight in late-type spirals and irregulars, in which young stars dominate both the UV and optical emission. Starburst galaxies with centrally concentrated, symmetric bursts display an apparent ``E/S0'' structure in the FUV, while starbursts associated with rings or mergers produce a peculiar morphology. We briefly discuss the inadequacy of the optically-defined Hubble sequence to describe FUV galaxy images and estimate morphological k-corrections, and we suggest some directions for future research with this dataset.Comment: Accepted for publication in the ApJS. 15 pages, 17 JPEG figures, 10 GIF figures. Paper and full resolution figures available at http://nedwww.ipac.caltech.edu/level5/Kuchinski/frames.htm

    Catatonia: Clinical overview of the diagnosis, treatment, and clinical challenges

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    Catatonia is a syndrome that has been associated with several mental illness disorders but that has also presented as a result of other medical conditions. Schizophrenia and other psychiatric disorders such as mania and depression are known to be associated with catatonia; however, several case reports have been published of certain medical conditions inducing catatonia, including hypo-natremia, cerebral venous sinus thrombosis, and liver transplantation. Neuroleptic Malignant Syndrome and anti-NMDA receptor encephalitis are also prominent causes of catatonia. Patients taking benzodiazepines or clozapine are also at risk of developing catatonia following the withdrawal of these medications—it is speculated that the prolonged use of these medications increases gamma-aminobutyric acid (GABA) activity and that discontinuation may increase excitatory neurotrans-mission, leading to catatonia. The treatment of catatonia often involves the use of benzodiazepines, such as lorazepam, that can be used in combination therapy with antipsychotics. Definitive treatment may be found with electroconvulsive therapy (ECT). Aberrant neuronal activity in different motor pathways, defective neurotransmitter regulation, and impaired oligodendrocyte function have all been proposed as the pathophysiology behind catatonia. There are many clinical challenges that come with catatonia and, as early treatment is associated with better outcomes, it becomes imperative to understand these challenges. The purpose of this manuscript is to provide an overview of these challenges and to look at clinical studies regarding the pathophysiology, diagnosis, and treatment of as well as the complications and risk factors associated with catatonia

    Novel Designer Benzodiazepines: Comprehensive Review of Evolving Clinical and Adverse Effects.

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    As tranquilizers, benzodiazepines have a wide range of clinical uses. Recently, there has been a significant rise in the number of novel psychoactive substances, including designer benzodiazepines. Flubromazolam(8-bromo-6-(2-fluorophenyl)-1-methyl-

    The Ultraviolet Imaging Telescope: Instrument and Data Characteristics

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    The Ultraviolet Imaging Telescope (UIT) was flown as part of the Astro observatory on the Space Shuttle Columbia in December 1990 and again on the Space Shuttle Endeavor in March 1995. Ultraviolet (1200-3300 Angstroms) images of a variety of astronomical objects, with a 40 arcmin field of view and a resolution of about 3 arcsec, were recorded on photographic film. The data recorded during the first flight are available to the astronomical community through the National Space Science Data Center (NSSDC); the data recorded during the second flight will soon be available as well. This paper discusses in detail the design, operation, data reduction, and calibration of UIT, providing the user of the data with information for understanding and using the data. It also provides guidelines for analyzing other astronomical imagery made with image intensifiers and photographic film.Comment: 44 pages, LaTeX, AAS preprint style and EPSF macros, accepted by PAS

    Viloxazine in the Treatment of Attention Deficit Hyperactivity Disorder

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    Attention deficit hyperactivity disorder (ADHD) is the most common neurodevelopmental disorder in children. Over the past twenty years, research on the disease and its characteristics and treatment options has grown exponentially. The first-line pharmacologic treatment of ADHD is stimulants, which have a response rate of ~70%. With the support of four phase 3 studies involving more than 1,000 pediatric patients 6–17 years old, the FDA has approved the non-stimulant, serotonin-norepinephrine modulating agent (SNMA) viloxazine in an extended-release capsule (viloxazine ER) for treatment of ADHD in children aged 6–17. Viloxazine modulates serotonergic activity as a selective 5-HT22B receptor antagonist and 5-HT2C receptor agonist and moderately inhibits norepinephrine transporter (NET), thus blocking the reuptake of norepinephrine. A phase 2 study by Johnson et al. found that once-daily dosing of viloxazine ER in 200, 300, or 400 mg dosages in children with ADHD for eight weeks resulted in a statistically significant reduction of ADHD-RS-IV total score. A post hoc analysis of data from four phase 3, randomized, placebo-controlled, double-blind, three-arm, clinical trials by Faraone et al. found that early response to viloxazine treatment, defined as a change in ADHD-RS-5 total score at week 2, best predicted the treatment response at week 6 [75% positive predictive power (PPP), 75% sensitivity]. Proper treatment of the symptoms and comorbidities associated with ADHD is crucial in improving a patient\u27s quality of life, cognitive function, and overall therapeutic outcomes. Viloxazine\u27s mechanism of action, clinical effects, and limited side effect profile point toward the drug\u27s relevance in the treatment of ADHD

    Selective serotonin reuptake inhibitors and adverse effects: A narrative review

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    Depression is the most prevalent psychiatric disorder in the world, affecting 4.4% of the global population. Despite an array of treatment modalities, depressive disorders remain difficult to manage due to many factors. Beginning with the introduction of fluoxetine to the United States in 1988, selective serotonin reuptake inhibitors (SSRIs) quickly became a mainstay of treatment for a variety of psychiatric disorders. The primary mechanism of action of SSRIs is to inhibit presynaptic reuptake of serotonin at the serotonin transporter, subsequently increasing serotonin at the postsynaptic membrane in the serotonergic synapse. The six major SSRIs that are marketed in the USA today, fluoxetine, citalopram, escitalopram, paroxetine, sertraline, and fluvoxamine, are a group of structurally unrelated molecules that share a similar mechanism of action. While their primary mechanism of action is similar, each SSRI has unique pharmacokinetics, pharmacodynamics, and side effect profile. One of the more controversial adverse effects of SSRIs is the black box warning for increased risk of suicidality in children and young adults aged 18–24. There is a lack of understanding of the complexities and interactions between SSRIs in the developing brain of a young person with depression. Adults, who do not have certain risk factors, which could be confounding factors, do not seem to carry this increased risk of suicidality. Ultimately, when prescribing SSRIs to any patient, a risk–benefit analysis must factor in the potential treatment effects, adverse effects, and dangers of the illness to be treated. The aim of this review is to educate clinicians on potential adverse effects of SSRIs

    Adjuvant drugs for peripheral nerve blocks: The role of nmda antagonists, neostigmine, epinephrine, and sodium bicarbonate

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    The potential for misuse, overdose, and chronic use has led researchers to look for other methods to decrease opioid consumption in patients with acute and chronic pain states. The use of peripheral nerve blocks for surgery has gained increasing popularity as it minimizes peripheral pain signals from the nociceptors of local tissue sustaining trauma and inflammation from surgery. The individualization of peripheral nerve blocks using adjuvant drugs has the potential to improve patient outcomes and reduce chronic pain. The major limitations of peripheral nerve blocks are their limited duration of action and dose-dependent adverse effects. Adjuvant drugs for peripheral nerve blocks show increasing potential as a solution for postoperative and chronic pain with their synergistic effects to increase the duration of action and decrease the required dosage of local anesthetic. N-methyl-d-aspartate (NMDA) receptor antagonists are a viable option for patients with opioid resistance and neuropathic pain due to their affinity to the neurotransmitter glutamate, which is released when patients experience a noxious stimulus. Neostigmine is a cholinesterase inhibitor that exerts its effect by competitively binding at the active site of acetylcholinesterase, which prevents the hydrolysis of acetylcholine and subsequently retaining acetylcholine at the nerve terminal. Epinephrine, also known as adrenaline, can potentially be used as an adjuvant to accelerate and prolong analgesic effects in digital nerve blocks. The theorized role of sodium bicarbonate in local anesthetic preparations is to increase the pH of the anesthetic. The resulting alkaline solution enables the anesthetic to more readily exist in its un-ionized form, which more efficiently crosses lipid membranes of peripheral nerves. However, more research is needed to show the efficacy of these adjuvants for nerve block prolongation as studies have been either mixed or have small sample sizes
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