23 research outputs found
Variable Interstellar Absorption toward the Halo Star HD 219188 - Implications for Small-Scale Interstellar Structure
Within the last 10 years, strong, narrow Na I absorption has appeared at
v_sun ~ -38 km/s toward the halo star HD 219188; that absorption has continued
to strengthen, by a factor 2-3, over the past three years. The line of sight
appears to be moving into/through a relatively cold, quiescent intermediate
velocity (IV) cloud, due to the 13 mas/yr proper motion of HD 219188; the
variations in Na I probe length scales of 2-38 AU/yr. UV spectra obtained with
the HST GHRS in 1994-1995 suggest N(H_tot) ~ 4.8 X 10^{17} cm^{-2}, ``halo
cloud'' depletions, n_H ~ 25 cm^{-3}, and n_e ~ 0.85-6.2 cm^{-3} (if T ~ 100 K)
for the portion of the IV cloud sampled at that time. The relatively high
fractional ionization, n_e/n_H >~ 0.034, implies that hydrogen must be
partially ionized. The N(Na I)/N(H_tot) ratio is very high; in this case, the
variations in Na I do not imply large local pressures or densities.Comment: 12 pages; aastex; to appear in ApJ
Polarized Broad H-alpha Emission from the LINER Nucleus of NGC 1052
Optical spectropolarimetry of the nucleus of the LINER NGC 1052, obtained at
the Keck Observatory, reveals a rise in polarization in the wings of the
H-alpha line profile. The polarization vector of H-alpha is offset by 67
degrees from the parsec-scale radio axis and by 83 degrees from the
kiloparsec-scale radio axis, roughly in accord with expectations for scattering
within the opening cone of an obscuring torus. The broad component of H-alpha
has FWHM ~ 2100 km/s in total flux and FWHM ~ 5000 km/s in polarized light.
Scattering by electrons is the mechanism most likely responsible for this
broadening, and we find T_e ~ 10^5 K for the scattering medium, similar to
values observed in Seyfert 2 nuclei. This is the first detection of a polarized
broad emission line in a LINER, demonstrating that unified models of active
galactic nuclei are applicable to at least some LINERs.Comment: 6 pages, 2 figures, prepared using the emulateapj style file,
accepted for publication in The Astrophysical Journal Letter
Predicting length of treatment for neonatal abstinence syndrome in methadone-exposed neonates.
OBJECTIVE: The objective of the study was to identify maternal variables predicting length of treatment for neonatal abstinence syndrome (NAS).
STUDY DESIGN: This was a retrospective cohort study of infants treated for NAS during 2000-2006 whose mothers were on methadone maintenance at delivery. Mixed-effects linear regression was used to examine the interaction of maternal and neonatal variables with length of treatment.
RESULTS: Of 204 neonates born to methadone exposed mothers, the average dose at delivery was 127 mg daily (25-340 mg) with median length of treatment 32 days (1-122 days). Trimester of initial exposure (P = .33), methadone dose at delivery (P = .198), body mass index (P = .31), antidepressant use (P = .40), cigarette use (P = .76), race (P = .78), and maternal age (P = .84) did not predict length of treatment. In the multivariate analysis, gestational age at delivery and benzodiazepine use were significant predictors of length of treatment.
CONCLUSION: Later gestational age and concomitant benzodiazepine use were associated with longer treatment
Independent Emission and Absorption Abundances for Planetary Nebulae
Emission-line abundances have been uncertain for more than a decade due to
unexplained discrepancies in the relative intensities of the forbidden lines
and weak permitted recombination lines in planetary nebulae (PNe) and H II
regions. The observed intensities of forbidden and recombination lines
originating from the same parent ion differ from their theoretical values by
factors of more than an order of magnitude in some of these nebulae. In this
study we observe UV resonance line absorption in the central stars of PNe
produced by the nebular gas, and from the same ions that emit optical forbidden
lines. We then compare the derived absorption column densities with the
emission measures determined from ground-based observations of the nebular
forbidden lines. We find for our sample of PNe that the collisionally excited
forbidden lines yield column densities that are in basic agreement with the
column densities derived for the same ions from the UV absorption lines. A
similar comparison involving recombination line column densities produces
poorer agreement, although near the limits of the formal uncertainties of the
analyses. An additional sample of objects with larger abundance discrepancy
factors will need to be studied before a stronger statement can be made that
recombination line abundances are not correct.Comment: 19 pages, 13 figures, accepted by ApJ. Preprint utilizes
emulateapj.cls v. 12/01/06 (included
Is there a role for the quantification of RRM1 and ERCC1 expression in pancreatic ductal adenocarcinoma?
<p>Abstract</p> <p>Background</p> <p>RRM1 and ERCC1 overexpression has been extensively investigated as potential predictive markers of tumor sensitivity to conventional chemotherapy agents, most thoroughly in lung cancer. However, data in pancreatic cancer are scarce.</p> <p>Methods</p> <p>We investigated the mRNA and protein expression of ERCC1 and RRM1 by RT-PCR and immunohistochemistry (IHC) in formalin-fixed, paraffin-embedded pancreatic ductal carcinoma (PDA) tissues. The primary outcome investigated was the association between RRM1 and ERCC1 expression and overall survival (OS) or disease-free survival (DFS).</p> <p>Results</p> <p>A total of 94 patients with resected PDA were included in this study. Most of them (87%) received gemcitabine based chemotherapy. Data for OS analysis was available in all cases but only 68% had enough information to estimate DFS. IHC analysis revealed information for 99% (93/94) and 100% of the cases for RRM1 and ERCC1 expression respectively. However, PCR data interpretation was possible in only 49 (52%) and 79 (84%) cases respectively. There was no significant association between high or low expression of either RRM1 or ERCC1, detected by IHC and OS (14.4 vs. 19.9 months; <it>P </it>= 0.5 and 17.1 vs. 19.9; <it>P </it>= 0.83 respectively) or PCR and OS (48.0 vs. 24.1 months; <it>P </it>= 0.21 and 22.0 vs. 16.0 months; <it>P </it>= 0.39 respectively). Similar results were obtained for DFS.</p> <p>Conclusions</p> <p>RRM1 and ERCC1 expression does not seem to have a clear predictive or prognostic value in pancreatic cancer. Our data raise some questions regarding the real clinical and practical significance of analyzing these molecules as predictors of outcomes.</p
Recommended from our members
Preadmission Hyperglycemia is an Independent Risk Factor for In-Hospital Symptomatic Pulmonary Embolism After Major Orthopedic Surgery
We investigate whether preadmission hyperglycemia is a risk factor for developing in-hospital symptomatic pulmonary embolism after major orthopedic surgery. Medical records of patients undergoing total hip or total knee arthroplasty from January 2001 to April 2006 were reviewed. The incidence of PE was 1.47% (107/7282 patients). Multivariate analysis showed that preadmission blood glucose (BG) of at least 200 mg/dL independently increased the risk of pulmonary embolism by 3.19 times (
P = .015), when compared with patients with BG of less than 110 mg/dL. Other significant risks factors were age (≥70 years old), body mass index of more than 30 kg/m
2, and congestive heart failure. Total knee had 2.19 times (
P = .002) more risk than total hip arthroplasty and bilateral procedure increased the risk by 2.13 times (
P = .015). Sex, American Society of Anesthesiologists status, duration of surgery, malignancy, pulmonary disease, hypertension, diabetes mellitus, dyslipidemia, sleep apnea, and stroke were not found to be significant risk factors for pulmonary embolism
Metabolic syndrome increases risk for pulmonary embolism after hip and knee arthroplasty
Aim To investigate whether patients with metabolic syndrome
(MetS) undergoing total hip or knee replacement
have an increased risk for pulmonary embolism (PE).
Methods We studied patients undergoing total hip or
total knee replacement from January 2001 to April 2006.
The diagnosis of PE was based on a positive finding with
a chest CT or a lung scan. Components of MetS were defined
as 1) BMI≥30 kg/m2, 2) non-fasting preadmission glucose
≥11.1 mmol/L or diagnosis of diabetes, 3) hypertension,
and 4) dyslipidemia. MetS was diagnosed if at least
three of these components were present.
Results Of 7282 patients, 107 (1.47%) were diagnosed
with PE. The incidence of PE in patients with 0, 1, 2, 3, and
4 MetS components was respectively 0.85% (16/1888; 95%
confidence interval [CI] 0.5%-1.4%), 1.24% (31/2500; 95%
CI 0.9%-1.8%), 1.76% (34/1936; 95% CI 1.2%-2.5%), 2.64%
(21/796; 95% CI 1.7%-4.1%), and 3.09% (5/162; 95% CI
1.1%-7.4%). The independent risk factors for PE were age
≥70, knee as opposite to hip replacement, bilateral knee
surgery, congestive heart failure, and MetS or the number
of MetS components. The odds of PE independently increased
1.6 times (95% CI 1.01-2.56; P = 0.043) for patients
with MetS and 1.23 times (95% CI 1.02-1.48; P = 0.028) per
each additional MetS component.
Conclusion Patients with MetS are at increased risk for PE
after total joint arthroplasty. The increasing number of MetS
components significantly increased the incidence of PE
Initial Tumor Metabolic Parameters (Maximum SUV and Metabolic Volume) Predict Death From Lung Cancer and Rapid SUV Decline is Associated with Local Control
Factors associated with local failure and death from lung cancer were evaluated based on post-treatment FDG-PET imaging in patients (pts) with non-small cell lung cancer (NSCLC).
PET-CT scans were obtained 6-8 weeks after thoracic RT and approximately every 3 months thereafter