We have found that radiation-hydrodynamic calculations that use the high flux model assumptions 1 can accurately predict the radiation drive produced by a laser-heated hohlraum under certain ...conditions, but can not predict drive over a broad range of parameters (pulse energy, hohlraum gas fill density, hohlraum case-to-capsule ratio). In particular, the model is accurate for ∼7 ns long laser pulses used to implode capsules with high density carbon (HDC) ablators in hohlraums with helium fill gas densities of 0-0.6 mg cc. By systematically varying the gas fill density from 0 to 1.6 mg cc we found that the agreement with drive begins to diverge for fills > 0.85 mg cc. This divergence from the model coincides with the onset of measureable SRS backscatter. In this same set of experiments the radiation drive symmetry inferred from the imploded shape of a gas-filled capsule is not predicted with this model. Finally, several possible fixes to the model to reduce the observed discrepancies are considered.
There is limited information about the applicability and effectiveness of tobacco and illicit drug use interventions in urban and racial/ethnic minority youth, a population with great need for ...prevention of alcohol and drug use. We pilot-tested the feasibility of a behavioral intervention to reduce alcohol, tobacco, and illicit drug use among urban young adults in New Orleans, Louisiana.
The 12-week intervention pilot project was developed to be implemented at a community-based social service organization that provides educational, juvenile justice-related case management, and mentoring services to youth with substance use and incarceration histories.
One-hour intervention sessions included interactive discussions and lesson reviews guided by a health educator and peer facilitators. Recruitment was done by case managers. Thirty African American young adults aged 16-21 years participated between January 2016 and July 2017.
We were able to adapt the 14-session intervention to a 12-session, weekly curriculum that was well-received by the target population. Average rating for each session was 9.5 ± 0.3 (scale 0-10). Youth were willing to engage in the program, but retention was low. Rates of alcohol and drug use were significantly higher within our pilot population than national estimates. We found no significant decreases in self-reported alcohol, tobacco, or illicit drug use after participation in the intervention.
Results emphasize the need to devote additional educational resources to intervention and retention factors for vulnerable youth. Individuals often experiment with drugs during adolescence; thus, this period represents a prime opportunity for education and intervention.
Abstract This paper presents the rationale and feasibility of standardized performance measures for use of pharmacotherapy in the treatment of substance use disorders (SUD), an evidence-based ...practice and critical component of treatment that is often underused. These measures have been developed and specified by the Washington Circle, to measure treatment of alcohol and opioid dependence with FDA-approved prescription medications for use in office-based general health and addiction specialty care. Measures were pilot tested in private health plans, the Veterans Health Administration (VHA), and Medicaid. Testing revealed that use of standardized measures using administrative data for overall use and initiation of SUD pharmacotherapy is feasible and practical. Prevalence of diagnoses and use of pharmacotherapy vary widely across health systems. Pharmacotherapy is generally used in a limited portion of those for whom it might be indicated. An important methodological point is that results are sensitive to specifications, so that standardization is critical to measuring performance across systems.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Patients with stable blunt great vessel injury (GVI) can have poor outcomes if the injury is not identified early. With current pediatric trauma radiation reduction efforts, these injuries may be ...missed. As a known association between scapular fracture and GVI exists in adult blunt trauma patients, we examined whether that same association existed in pediatric blunt trauma patients.
Bluntly injured patients younger than 18 years old were identified from 2012 to 2014 in the National Trauma Data Bank. Great vessel injury included all major thoracic vessels and carotid/jugular. Demographics of patients with and without scapular fracture were compared with descriptive statistics. The χ test was used to examine this association using SAS Version 9.4 (SAS Institute, Inc, Cary, NC).
We found a significant association between pediatric scapular fracture and GVI. Of 291,632 children identified, 1,960 had scapular fractures. Children with scapular fracture were 10 times more likely to have GVI (1.2%) compared to those without (0.12%, p < 0.0001). Most common GVI seen were carotid artery, thoracic aorta, and brachiocephalic or subclavian artery or vein. Children with both scapular fracture and GVI were most commonly injured by motor vehicles (57% collision, 26% struck).
Injured children with blunt scapular fracture have a 10-fold greater risk of having a GVI when compared to children without scapular fracture. Presence of blunt traumatic scapular fracture should have appropriate index of suspicion for a significant GVI in pediatric trauma patients.
Epidemiologic and prognostic study, level III; Therapeutic, level IV.
Eukaryotic cell division is an orderly and timely process involving the error-free segregation of chromosomes and cytoplasmic components to give rise to two separate daughter cells. Defects in genome ...maintenance mechanisms such as cell cycle checkpoints and DNA repair can impact the segregation of the genome during mitosis leading to multiple chromosomal imbalances. In mammals, the DNA damage checkpoint effector Checkpoint Kinase 1 (Chk1) is essential for responses to DNA replication errors, external DNA damage, and chromatin breaks. We reported recently that Chk1 also was essential for chromosome segregation and completion of cytokinesis to prevent genomic instability. Our studies demonstrated that Chk1 deficiency in mitotic cells causes chromosome mis-alignment, lagging chromosomes, chromosome mis- segregation, cytokinetic regression, and binucleation. In addition, abrogation of Chk1 resulted in aberrant localization of mitotic Aurora B kinase at the metaphase plate, anaphase spindle midzone, and cytokinetic midbody as studied both in various cell lines and in a mouse model. Therefore, inappropriate regulation of Chk1 levels during cell cycle progression will result in failed cell division and enhanced genomic instability.
Full text
Available for:
BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
In this paper, we analyze a discrete choice model for partially ordered alternatives. The alternatives are differentiated along two dimensions: the first an unordered 'horizontal' dimension, and the ...second an ordered 'vertical' dimension. The model can be used in circumstances in which individuals choose among products of different brands, wherein each brand offers an ordered choice menu, for example, by offering products of varying quality. The unordered-ordered nature of the discrete choice problem is used to characterize the identified set of model parameters. Following an initial nonparametric analysis that relies on shape restrictions inherent in the ordered dimension of the problem, we then provide a specialized analysis for parametric specifications that generalize common ordered choice models. We characterize conditional choice probabilities as a function of model primitives with particular analysis focusing on cases in which unobservable taste for quality of each brand offering is multivariate normally distributed. We provide explicit formulae used for estimation and inference via maximum likelihood, and we consider inference based on Wald and quasi-likelihood ratio statistics, the latter of which can be robust to a possible lack of point identification. An empirical illustration is conducted using data on razor blade purchases in which each brand has product offerings vertically differentiated by quality.
Full text
Available for:
BFBNIB, CEKLJ, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
IMPORTANCE: Chronic pain is debilitating and profoundly affects health-related quality of life. Spinal cord stimulation (SCS) is a well-established therapy for chronic pain; however, SCS has been ...limited by the inability to directly measure the elicited neural response, precluding confirmation of neural activation and continuous therapy. A novel SCS system measures the evoked compound action potentials (ECAPs) to produce a real-time physiological closed-loop control system. OBJECTIVE: To determine whether ECAP-controlled, closed-loop SCS is associated with better outcomes compared with fixed-output, open-loop SCS at 24 months following implant. DESIGN, SETTING, AND PARTICIPANTS: The Evoke study was a double-blind, randomized, controlled, parallel arm clinical trial with 36 months of follow-up. Participants were enrolled from February 2017 to 2018, and the study was conducted at 13 US investigation sites. SCS candidates with chronic, intractable back and leg pain refractory to conservative therapy, who consented, were screened. Key eligibility criteria included overall, back, and leg pain visual analog scale score of 60 mm or more; Oswestry Disability Index score of 41 to 80; stable pain medications; and no previous SCS. Analysis took place from October 2020 to April 2021. INTERVENTIONS: ECAP-controlled, closed-loop SCS was compared with fixed-output, open-loop SCS. MAIN OUTCOMES AND MEASURES: Reported here are the 24-month outcomes of the trial, which include all randomized patients in the primary and safety analyses. The primary outcome was a reduction of 50% or more in overall back and leg pain assessed at 3 and 12 months (previously published). RESULTS: Of 134 randomized patients, 65 (48.5%) were female and the mean (SD) age was 55.2 (10.6) years. At 24 months, significantly more closed-loop than open-loop patients were responders (≥50% reduction) in overall pain (53 of 67 79.1% in the closed-loop group; 36 of 67 53.7% in the open-loop group; difference, 25.4% 95% CI, 10.0%-40.8%; P = .001). There was no difference in safety profiles between groups (difference in rate of study-related adverse events: 6.0 95% CI, −7.8 to 19.7). Improvements were also observed in health-related quality of life, physical and emotional functioning, and sleep, in parallel with opioid reduction or elimination. Objective neurophysiological measurements substantiated the clinical outcomes and provided evidence of activation of inhibitory pain mechanisms. CONCLUSIONS AND RELEVANCE: ECAP-controlled, closed-loop SCS, which elicited a more consistent neural response, was associated with sustained superior pain relief at 24 months, consistent with the 3- and 12-month outcomes.
PDF
