67 research outputs found

    EVLA imaging of methanimine and hydrogen cyanide in Arp 220

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    We present observations of the 5289.8MHz110→1111{10}\rightarrow1_{11} transition of the pre-biotic molecule methanimine(\meth) and the 6731.9 MHz J=5 direct ∣|-type transition in the vibrationally excited(ν2=1\nu_2=1) state of hydrogen cyanide(HCN) toward the nearest Ultraluminous Infrared Galaxy, Arp 220, taken with the Expanded Very Large Array (EVLA) in A configuration. The 5289.8 MHz \meth\ line was detected in emission toward the western nucleus, but not toward the eastern nucleus. The 6731.9 MHz HCN line was detected in absorption toward the western nucleus, but not toward the eastern nucleus. Both of these are new results from the observations reported in this thesis, and are in contrast with rotational HCN transitions that trace cold and dense molecular gas and have been observed in emission toward both nuclei. We have also confirmed that the\meth\line is most like a maser; this represents the first independent confirmation of the only \meth\ maser ever detected. This \meth\ maser was found to have an isotropic luminosity of 5L⊙L_\odot, close to the luminosity (12LodotL_odot) of a formaldehyde maser in Arp 220, and similar to the luminosities of \h\ kilomasers, most of which are believed to be excited in active star forming regions in external galaxies. The western nucleus is known to have undergone an intense starburst, and we conclude that the \meth\ maser is being amplified in the foreground gas along the line of sight to the western nucleus by the background continuum of the nucleus. The absorbing HCN gas toward the western nucleus was found to have a column density ∼1.04×1019\sim 1.04\times 10^{19}cm−2^{-2} corresponding to an excitation temperature near 550 K; the column density may be an order of magnitude higher at ∼1020\sim 10^{20} cm−2Siftheexcitationtemperaturehasalowervalueof150K.IfweassumethattheHCNabundancerelativetomolecularhydrogenisthesameasinourGalaxy(^{-2}S if the excitation temperature has a lower value of 150K. If we assume that the HCN abundance relative to molecular hydrogen is the same as in our Galaxy (10^{-5}),thisgivesabout), this gives about 1 \times 10^{24}cmcm^{-2}(or(or10^{25}cm cm^{-2}$) for the molecular hydrogen column density, which is in reasonable agreement with the values reported by other observers toward the western nucleus. We conclude that the observed HCN absorption is likely taking place in a column of highly excited molecular gas in the foreground of the western nucleus. The observations reported in this thesis provide a self consistent picture of highly excited gas in the foreground of the western nucleus, and a convincing demonstration that the line of sight toward the western nucleus has different physical conditions than that toward the eastern nucleus. These observations have demonstrated conclusively that a new range of molecular transitions can now be detected and imaged with cm-wavelength telescopes like the EVLA, thus opening up new opportunities for the study of the physics and chemistry of other galaxies

    Perspectives of family medicine physicians on the importance of adolescent preventive care: a multivariate analysis

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    BACKGROUND: The study objective was to identify commonalities amongst family medicine physicians who endorse annual adolescent visits. METHODS: A nationally weighted representative on-line survey was used to explore pediatrician (N = 204) and family medicine physicians (N = 221) beliefs and behaviors surrounding adolescent wellness. Our primary outcome was endorsement that adolescents should receive annual preventive care visits. RESULTS: Pediatricians were significantly more likely (p < .01) to endorse annual well visits. Among family medicine physicians, bivariate comparisons were conducted between those who endorsed an annual visit (N = 164) compared to those who did not (N = 57) with significant predictors combined into two multivariate logistic regression models. Model 1 controlled for: patient race, proportion of 13-17 year olds in provider's practice, discussion beliefs scale and discussion behaviors with parents scale. Model 2 controlled for the same first three variables as well as discussion behaviors with adolescents scale. Model 1 showed for each discussion beliefs scale topic selected, family medicine physicians had 1.14 increased odds of endorsing annual visits (p < .001) and had 1.11 greater odds of endorsing annual visits with each one-point increase in discussion behaviors with parents scale (p = .51). Model 2 showed for each discussion beliefs scale topic selected, family medicine physicians had 1.15 increased odds of also endorsing the importance of annual visits (p < .001). CONCLUSIONS: Family medicine physicians that endorse annual visits are significantly more likely to affirm they hold strong beliefs about topics that should be discussed during the annual exam. They also act on these beliefs by talking to parents of teens about these topics. This group appears to focus on quality of care in thought and deed

    Regulation of Class-Switch Recombination and Plasma Cell Differentiation by Phosphatidylinositol 3-Kinase Signaling

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    SummaryClass-switch recombination (CSR) is essential for humoral immunity. However, the regulation of CSR is not completely understood. Here we demonstrate that phosphatidylinositol 3-kinase (PI3K) actively suppressed the onset and frequency of CSR in primary B cells. Consistently, mice lacking the lipid phosphatase, PTEN, in B cells exhibited a hyper-IgM condition due to impaired CSR, which could be restored in vitro by specific inhibition of PI3Kδ. Inhibition of CSR by PI3K was partially dependent on the transcription factor, BLIMP1, linking plasma cell commitment and cessation of CSR. PI3K-dependent activation of the serine-threonine kinase, Akt, suppressed CSR, in part, through the inactivation of the Forkhead Box family (Foxo) of transcription factors. Reduced PI3K signaling enhanced the expression of AID (activation-induced cytidine deaminase) and accelerated CSR. However, ectopic expression of AID could not fully overcome inhibition of CSR by PI3K, suggesting that PI3K regulates both the expression and function of AID

    Elastase activity on sputum neutrophils correlates with severity of lung disease in cystic fibrosis

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    Neutrophil elastase (NE) is a key risk factor for severity of cystic fibrosis (CF) lung disease. Recent studies identified increased NE activity on the surface of airway neutrophils from CF-like mice and patients with CF. However, the role of surface-bound NE in CF lung disease remains unknown. We determined the relationship between surface-bound NE activity and severity of lung disease in CF.Surface-bound NE activity was measured on sputum neutrophils from 35 CF patients and eight healthy controls using novel lipidated Förster resonance energy transfer reporters and correlated with free NE activity, neutrophil counts, interleukin-8, myeloperoxidase and antiproteases in sputum supernatant, and with lung function parameters.Surface-bound NE activity was increased in CF compared to healthy controls (p&lt;0.01) and correlated with free NE activity (p&lt;0.05) and other inflammation markers (p&lt;0.001). Surface-bound and free NE activity correlated with forced expiratory volume in 1 s % predicted (p&lt;0.01 and p&lt;0.05), but only surface-bound NE activity correlated with plethysmographic functional residual capacity % pred (p&lt;0.01) in patients with CF.We demonstrate that surface-bound NE activity on airway neutrophils correlates with severity of lung disease in patients with CF. Our results suggest that surface-bound NE activity may play an important role in the pathogenesis and serve as novel biomarker in CF lung disease.</jats:p

    Incident and long-term opioid therapy among patients with psychiatric conditions and medications: a national study of commercial health care claims

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    There is growing evidence that opioid prescribing in the United States follows a pattern in which patients who are at the highest risk of adverse outcomes from opioids are more likely to receive long-term opioid therapy. These patients include, in particular, those with substance use disorders (SUDs) and other psychiatric conditions. This study examined health insurance claims among 10,311,961 patients who filled prescriptions for opioids. Specifically, we evaluated how opioid receipt differed among patients with and without a wide range of preexisting psychiatric and behavioral conditions (ie, opioid and nonopioid SUDs, suicide attempts or other self-injury, motor vehicle crashes, and depressive, anxiety, and sleep disorders) and psychoactive medications (ie, antidepressants, benzodiazepines, hypnotics, mood stabilizers, antipsychotics, and medications used for SUD, tobacco cessation, and attention-deficit/hyperactivity disorder). Relative to those without, patients with all assessed psychiatric conditions and medications had modestly greater odds of subsequently filling prescriptions for opioids and, in particular, substantially greater risk of long-term opioid receipt. Increases in risk for long-term opioid receipt in adjusted Cox regressions ranged from approximately 1.5-fold for prior attention-deficit/hyperactivity disorder medication prescriptions (hazard ratio [HR] = 1.53; 95% confidence interval [CI], 1.48-1.58) to approximately 3-fold for prior nonopioid SUD diagnoses (HR = 3.15; 95% CI, 3.06-3.24) and nearly 9-fold for prior opioid use disorder diagnoses (HR = 8.70; 95% CI, 8.20-9.24). In sum, we found evidence of greater opioid receipt among commercially insured patients with a breadth of psychiatric conditions. Future studies assessing behavioral outcomes associated with opioid prescribing should consider preexisting psychiatric conditions

    Association of Mental Health Conditions and Treatments With Long-term Opioid Analgesic Receipt Among Adolescents

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    Importance: Adults with mental health conditions are more likely than those without to receive long-term opioid therapy. Less is known about opioid therapy among adolescents, especially those with mental health conditions. Objective: To examine associations between preexisting mental health conditions and treatments and initiation of any opioid and long-term opioid therapy among adolescents. Design, Setting, and Participants: A cohort of 1 224 520 incident opioid recipients without cancer diagnoses aged 14 to 18 years at first receipt was extracted from nationwide commercial health care claims data from January 1, 2003, to December 31, 2014. Analysis was conducted from August 19, 2016, to November 16, 2017. Associations between preexisting mental health conditions and treatments and any opioid receipt were examined by comparing recipients with nonrecipients matched on sex, calendar year and years of age of first enrollment, and months of enrollment (prior to the index month for recipients, ever for nonrecipients). Associations between preexisting mental health conditions and treatments and subsequent long-term opioid therapy were examined among recipients with at least 6 months' follow-up using Cox proportional hazards regressions adjusted for demographics. Exposures: Mental health condition diagnoses and treatments recorded in inpatient, outpatient, and filled-prescription claims prior to opioid receipt. Main Outcomes and Measures: Opioid receipt, defined as any opioid analgesic prescription claim, and long-term opioid therapy, defined as more than 90 days' supply within a 6-month window having no gaps in supply of more than 32 days. Results: Of the 1 224 520 new opioid recipients included, the median age at first receipt was 17 years (interquartile range, 16-18 years), and 51.1% were female. Median follow-up after first receipt was 625 days (interquartile range, 255-1268 days). Adolescents with anxiety, mood, neurodevelopmental, sleep, and nonopioid substance use disorders and most mental health treatments were significantly more likely to receive any opioid (odds ratios from 1.13 [95% CI, 1.10-1.16] for nonopioid substance use disorders to 1.69 [95% CI, 1.58-1.81] for nonbenzodiazepine hypnotics). Among the 1 000 453 opioid recipients (81.7%) who had at least 6 months' follow-up, the cumulative incidence of long-term opioid therapy was 3.0 (95% CI, 2.8-3.1) per 1000 recipients within 3 years after first opioid receipt. All preexisting mental health conditions and treatments were strongly associated with higher rates of long-term opioid therapy (adjusted hazard ratios from 1.73 [95% CI 1.54-1.95] for attention-deficit/hyperactivity disorder to 8.90 [95% CI, 5.85-13.54] for opioid use disorder). Conclusions and Relevance: Commercially insured adolescents with many types of preexisting mental health conditions and treatments were modestly more likely to receive any opioid and were substantially more likely to subsequently transition to long-term opioid therapy relative to those without, although overall rates of long-term opioid therapy were low

    A Census of Early-phase High-mass Star Formation in the Central Molecular Zone

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    We present new observations of the C-band continuum emission and masers to assess high-mass (>8 M⊙{M}_{\odot }) star formation at early evolutionary phases in the inner 200 pc of the Central Molecular Zone (CMZ) of the Galaxy. The continuum observation is complete to free–free emission from stars above 10–11 M⊙{M}_{\odot } in 91% of the covered area. We identify 104 compact sources in the continuum emission, among which five are confirmed ultracompact H ii regions, 12 are candidates of ultracompact H ii regions, and the remaining 87 sources are mostly massive stars in clusters, field stars, evolved stars, pulsars, extragalactic sources, or of unknown nature that is to be investigated. We detect class ii CH3OH masers at 23 positions, among which six are new detections. We confirm six known H2CO masers in two high-mass star-forming regions and detect two new H2CO masers toward the Sgr C cloud, making it the ninth region in the Galaxy that contains masers of this type. In spite of these detections, we find that current high-mass star formation in the inner CMZ is only taking place in seven isolated clouds. The results suggest that star formation at early evolutionary phases in the CMZ is about 10 times less efficient than expected from the dense gas star formation relation, which is in line with previous studies that focus on more evolved phases of star formation. This means that if there will be any impending, next burst of star formation in the CMZ, it has not yet begun
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