Effect of Short Chain Branching on the Interlamellar Structure of Semicrystalline Polyethylene

We use molecular simulations with a united atom force field to examine the effect of short chain branching (SCB) on the noncrystalline, interlamellar structure typical of linear low density polyethylene (LLDPE). The model is predicated on a metastable thermodynamic equilibrium within the interlamellar space of the crystal stack and accounts explicitly for the various chain topologies (loops, tails, and bridges) therein. We examine three branched systems containing methyl, ethyl, and butyl side branches and compare our results to high density polyethylene (HDPE), without branches. We also compare results for two united atom force fields, PYS and TraPPE-UA, within the context of these simulations. In contrast to conventional wisdom, our simulations indicate that the thicknesses of the interfacial regions in systems with SCB are smaller than those observed for a linear polyethylene without branches and that branches are uniformly distributed throughout the interlamellar region. We find a prevalence of gauche states along the backbone due to the presence of branches and an abrupt decrease in the orientational order in the region immediately adjacent to the crystallite

Vertical Turbulent Cooling of the Mixed Layer in the Atlantic ITCZ and Trade Wind Regions

The causes of the seasonal cycle of vertical turbulent cooling at the base of the mixed layer are assessed using observations from moored buoys in the tropical Atlantic Intertropical Convergence Zone (ITCZ) (4°N, 23°W) and trade wind (15°N, 38°W) regions together with mixing parameterizations and a one-dimensional model. At 4°N the parameterized turbulent cooling rates during 2017–2018 and 2019 agree with indirect estimates from the climatological mooring heat budget residual: both show mean cooling of 25–30 W m (Formula presented.) during November–July, when winds are weakest and the mixed layer is thinnest, and 0–10 W m (Formula presented.) during August–October. Mixing during November–July is driven by variability on multiple time scales, including subdiurnal, near-inertial, and intraseasonal. Shear associated with tropical instability waves (TIWs) is found to generate mixing and monthly mean cooling of 15–30 W m (Formula presented.) during May–July in 2017 and 2019. At 15°N the seasonal cycle of turbulent cooling is out of phase compared to 4°N, with largest cooling of up to 60 W m (Formula presented.) during boreal fall. However, the relationships between wind speed, mixed layer depth, and turbulent mixing are similar: weaker mean winds and a thinner mixed layer in the fall are associated with stronger mixing and turbulent cooling of SST. These results emphasize the importance of seasonal modulations of mixed layer depth at both locations and shear from TIWs at 4°N

Imaging correlates of molecular signatures in oligodendrogliomas.

Molecular subsets of oligodendroglioma behave in biologically distinct ways. Their locations in the brain, rates of growth, and responses to therapy differ with their genotypes. Retrospectively, we inquired whether allelic loss of chromosomal arms 1p and 19q, an early molecular event and favorable prognostic marker in oligodendrogliomas, were reflected in their appearance on magnetic resonance imaging. Loss of 1p and 19q was associated with an indistinct border on T(1) images and mixed intensity signal on T(1) and T(2). Loss of 1p and 19q was also associated with paramagnetic susceptibility effect and with calcification, a common histopathological finding in oligodendrogliomas. These data encourage prospective evaluation of molecular alterations and magnetic resonance imaging characteristics of glial neoplasms

Stroke impact on mortality and psychologic morbidity within the Childhood Cancer Survivor Study.

BackgroundPoor socioeconomic and health-related quality of life (HRQOL) outcomes in survivors of childhood cancer can lead to distress and overall negatively impact the lives of these individuals. The current report has highlighted the impact of stroke and stroke recurrence on mortality, psychological HRQOL, and socioeconomic outcomes within the Childhood Cancer Survivor Study (CCSS).MethodsThe CCSS is a retrospective cohort study with longitudinal follow-up concerning survivors of pediatric cancer who were diagnosed between 1970 and 1986. Mortality rates per 100 person-years were calculated across 3 periods: 1) prior to stroke; 2) after first stroke and before recurrent stroke; and 3) after recurrent stroke. Socioeconomic outcomes, the standardized Brief Symptoms Inventory-18, the Medical Outcomes Study 36-Item Short Form Health Survey, and the CCSS-Neurocognitive Questionnaire also were assessed.ResultsAmong 14,358 participants (median age, 39.7 years), 224 had a stroke after their cancer diagnosis (single stroke in 161 patients and recurrent stroke in 63 patients). Based on 2636 deaths, all-cause late mortality rates were 0.70 (95% CI, 0.68-0.73) prior to stroke, 1.03 (95% CI, 0.73-1.46) after the first stroke, and 2.42 (95% CI, 1.48-3.94) after the recurrent stroke. Among 7304 survivors, those with stroke were more likely to live with a caregiver (single stroke odds ratio [OR], 2.3 [95% CI, 1.4-3.8]; and recurrent stroke OR, 5.3 [95% CI, 1.7-16.8]) compared with stroke-free survivors. Stroke negatively impacted task efficiency (single stroke OR, 2.4 [95% CI, 1.4-4.1] and recurrent stroke OR, 3.3 [95% CI, 1.1-10.3]) and memory (single stroke OR, 2.1 [95% CI, 1.2-3.7]; and recurrent stroke OR, 3.5 [95% CI, 1.1-10.5]).ConclusionsStroke and stroke recurrence are associated with increased mortality and negatively impact HRQOL measures in survivors of pediatric cancer

An efficacy trial of an electronic health record-based strategy to inform patients on safe medication use: The role of written and spoken communication

We tested the feasibility and efficacy of an electronic health record (EHR) strategy that automated the delivery of print medication information at the time of prescribing

Intra-arterial nitroglycerin as directed acute treatment in experimental ischemic stroke

Background: Nitroglycerin (also known as glyceryl trinitrate (GTN)), a vasodilator best known for treatment of ischemic heart disease, has also been investigated for its potential therapeutic benefit in ischemic stroke. The completed Efficacy of Nitric Oxide in Stroke trial suggested that GTN has therapeutic benefit with acute (within 6 hours) transdermal systemic sustained release therapy. Objective: To examine an alternative use of GTN as an acute therapy for ischemic stroke following successful recanalization. Methods: We administered GTN IA following transient middle cerebral artery occlusion in mice. Because no standard dose of GTN is available following emergent large vessel occlusion, we performed a dose–response (3.12, 6.25, 12.5, and 25 .ig/.iL) analysis. Next, we looked at blood perfusion (flow) through the middle cerebral artery using laser Doppler flowmetry. Functional outcomes, including forced motor movement rotor rod, were assessed in the 3.12, 6.25, and 12.5 .ig/.iL groups. Histological analysis was performed using cresyl violet for infarct volume, and glial fibrillary activating protein (GFAP) and NeuN immunohistochemistry for astrocyte activation and mature neuron survival, respectively. Results: Overall, we found that acute post-stroke IA GTN had little effect on vessel dilatation after 15 min. Functional analysis showed a significant difference between GTN (3.12 and 6.25 .ig/.iL) and control at post-stroke day 1. Histological measures showed a significant reduction in infarct volume and GFAP immunoreactivity and a significant increase in NeuN. Conclusions: These results demonstrate that acute IA GTN is neuroprotective in experimental ischemic stroke and warrants further study as a potentially new stroke therapy

Flow field visualization of entangled polybutadiene solutions under nonlinear viscoelastic flow conditions

Using self-designed particle visualization instrumentation, startup shear and step-strain tests were conducted under a series of systematically varied rheological and geometrical conditions, and the velocity profiles in three different well-entangled polybutadiene/oligomer solutions were obtained. For startup shear tests, in the regime of entanglement densities up to 89 and nominal reptation Weissenberg numbers up to 18.6, we generally observe either wall slip and a linear velocity/strain profile or simply the linear profile with no wall slip unless a massive edge fracture or instability has occurred in the sample. Meanwhile, step-strain tests conducted at similar and higher step Weissenberg numbers revealed little particle motion upon cessation. These results lead us to a conclusion that there is no compelling evidence of shear banding or nonquiescent relaxation in the range of entanglement density and Wi investigated; we interpret the results to imply that any observed banding probably correlates with edge effects.National Science Foundation (U.S.) (Grant DMR-0934305

Eight Characteristics of Rigorous Multilevel Implementation Research: A Step-by-Step Guide

Background Although healthcare is delivered in inherently multilevel contexts, implementation science has no widely endorsed methodological standards defining the characteristics of rigorous, multilevel implementation research. We identify and describe eight characteristics of high-quality, multilevel implementation research to encourage discussion, spur debate, and guide decision-making around study design and methodological issues. Recommendations Implementation researchers who conduct rigorous multilevel implementation research demonstrate the following eight characteristics. First, they map and operationalize the specific multilevel context for defined populations and settings. Second, they define and state the level of each construct under study. Third, they describe how constructs relate to each other within and across levels. Fourth, they specify the temporal scope of each phenomenon at each relevant level. Fifth, they align measurement choices and construction of analytic variables with the levels of theories selected (and hypotheses generated, if applicable). Sixth, they use a sampling strategy consistent with the selected theories or research objectives and sufficiently large and variable to examine relationships at requisite levels. Seventh, they align analytic approaches with the chosen theories (and hypotheses, if applicable), ensuring that they account for measurement dependencies and nested data structures. Eighth, they ensure inferences are made at the appropriate level. To guide implementation researchers and encourage debate, we present the rationale for each characteristic, actionable recommendations for operationalizing the characteristics in implementation research, a range of examples, and references to make the characteristics more usable. Our recommendations apply to all types of multilevel implementation study designs and approaches, including randomized trials, quantitative and qualitative observational studies, and mixed methods. Conclusion These eight characteristics provide benchmarks for evaluating the quality and replicability of multilevel implementation research and promote a common language and reference points. This, in turn, facilitates knowledge generation across diverse multilevel settings and ensures that implementation research is consistent with (and appropriately leverages) what has already been learned in allied multilevel sciences. When a shared and integrated description of what constitutes rigor is defined and broadly communicated, implementation science is better positioned to innovate both methodologically and theoretically

Cardiometabolic results from an armband-based weight loss trial

Purpose: This report examines the blood chemistry and blood pressure (BP) results from the Lifestyle Education for Activity and Nutrition (LEAN) study, a randomized weight loss trial. A primary purpose of the study was to evaluate the effects of real-time self-monitoring of energy balance (using the SenseWearTM Armband, BodyMedia, Inc Pittsburgh, PA) on these health factors. Methods: 164 sedentary overweight or obese adults (46.8 ± 10.8 years; BMI 33.3 ± 5.2 kg/m2; 80% women) took part in the 9-month study. Participants were randomized into 4 conditions: a standard care condition with an evidence-based weight loss manual (n = 40), a group-based behavioral weight loss program (n = 44), and armband alone condition (n = 41), and a group plus armband (n = 39) condition. BP, fasting blood lipids and glucose were measured at baseline and 9 months. Results: 99 participants (60%) completed both baseline and follow-up measurements for BP and blood chemistry analysis. Missing data were handled by baseline carried forward. None of the intervention groups had significant changes in blood lipids or BP when compared to standard care after adjustment for covariates, though within-group lowering was found for systolic BP in group and group + armband conditions, a rise in total cholesterol and LDL were found in standard care and group conditions, and a lowering of triglycerides was found in the two armband conditions. Compared with the standard care condition, fasting glucose decreased significantly for participants in the group, armband, and group + armband conditions (all P \u3c 0.05), respectively. Conclusion: Our results suggest that using an armband program is an effective strategy to decrease fasting blood glucose. This indicates that devices, such as the armband, can be a successful way to disseminate programs that can improve health risk factors. This can be accomplished without group-based behavioral programs, thereby potentially reducing costs

CO in Protostars (COPS): HerschelHerschel-SPIRE Spectroscopy of Embedded Protostars

We present full spectral scans from 200-670$\mu$m of 26 Class 0+I protostellar sources, obtained with $Herschel$-SPIRE, as part of the "COPS-SPIRE" Open Time program, complementary to the DIGIT and WISH Key programs. Based on our nearly continuous, line-free spectra from 200-670 $\mu$m, the calculated bolometric luminosities ($L_{\rm bol}$) increase by 50% on average, and the bolometric temperatures ($T_{\rm bol}$) decrease by 10% on average, in comparison with the measurements without Herschel. Fifteen protostars have the same Class using $T_{\rm bol}$ and $L_{\rm bol}$/$L_{\rm submm}$. We identify rotational transitions of CO lines from J=4-3 to J=13-12, along with emission lines of $^{13}$CO, HCO$^+$, H$_{2}$O, and [CI]. The ratios of $^{12}$CO to $^{13}$CO indicate that $^{12}$CO emission remains optically thick for $J_{\rm up}$ < 13. We fit up to four components of temperature from the rotational diagram with flexible break points to separate the components. The distribution of rotational temperatures shows a primary population around 100 K with a secondary population at $\sim$350 K. We quantify the correlations of each line pair found in our dataset, and find the strength of correlation of CO lines decreases as the difference between $J$-level between two CO lines increases. The multiple origins of CO emission previously revealed by velocity-resolved profiles are consistent with this smooth distribution if each physical component contributes to a wide range of CO lines with significant overlap in the CO ladder. We investigate the spatial extent of CO emission and find that the morphology is more centrally peaked and less bipolar at high-$J$ lines. We find the CO emission observed with SPIRE related to outflows, which consists two components, the entrained gas and shocked gas, as revealed by our rotational diagram analysis as well as the studies with velocity-resolved CO emission.Comment: 50 pages, 18 figures, accepted to ApJS. Revised for Table 6 and Figure