750 research outputs found

    Predicting length of treatment for neonatal abstinence syndrome in methadone-exposed neonates.

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    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

    Stress analysis of a simplified compression plate fixation system for fractured bones

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    AbstractA three-dimensional finite element model was generated of a plexiglass tube with an attached six-hole stainless steel compression plate to study the mechanics of internal fixation of fractured long bones. To demonstrate the importance of the plate-bone interface, this interface was represented three different ways in the finite element model. A plated tube with a uniform transverse osteotomy gap was also examined to study the mechanics of plated fractured bones. To validate the model, the results for the intact plated tube were compared to composite beam theory and strain gauge data from an instrumented physical model. Applications of the finite element model data included the prediction of screw failure modes, plate-induced osteopenia, and multi-axial strains in an interfragmentary region. The addition of sliding motion between the plate and tube resulted in a deviation from composite beam theory and improved correspondence with strain gage data when compared to a model having the plate and tube securely bonded. Sliding motion resulted in a much smaller region of bone subjected to reduced axial stress levels, which may decrease the extent of plate-induced osteopenia. The complex nature of induced strains in an osteotomy gap was also demonstrated, along with the tendency for failure of the screws nearest the fracture site

    Long-Term and Global Tradeoffs between Bio-Energy, Feed, and Food

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    Projections of U.S. ethanol production and its impacts on planted acreage, crop prices, livestock production and prices, trade, and retail food costs are presented under the assumption that current tax credits and trade policies are maintained. The projections were made using a multi-product, multi-country deterministic partial equilibrium model. The impacts of higher oil prices, a drought combined with an ethanol mandate, and removal of land from the Conservation Reserve Program (CRP) relative to baseline projections are also presented. The results indicate that expanded U.S. ethanol production will cause long-run crop prices to increase. In response to higher feed costs, livestock farmgate prices will increase enough to cover the feed cost increases. Retail meat, egg, and dairy prices will also increase. If oil prices are permanently $10-per-barrel higher than assumed in the baseline projections, U.S. ethanol will expand significantly. The magnitude of the expansion will depend on the future makeup of the U.S. automobile fleet. If sufficient demand for E-85 from flex-fuel vehicles is available, corn-based ethanol production is projected to increase to over 30 billion gallons per year with the higher oil prices. The direct effect of higher feed costs is that U.S. food prices would increase by a minimum of 1.1% over baseline levels. Results of a model of a 1988-type drought combined with a large mandate for continued ethanol production show sharply higher crop prices, a drop in livestock production, and higher food prices. Corn exports would drop significantly, and feed costs would rise. Wheat feed use would rise sharply. Taking additional land out of the CRP would lower crop prices in the short run. But because long-run corn prices are determined by ethanol prices and not by corn acreage, the long-run impacts on commodity prices and food prices of a smaller CRP are modest. Cellulosic ethanol from switchgrass and biodiesel from soybeans do not become economically viable in the Corn Belt under any of the scenarios. This is so because high energy costs that increase the prices of biodiesel and switchgrass ethanol also increase the price of corn-based ethanol. So long as producers can choose between soybeans for biodiesel, switchgrass for ethanol, and corn for ethanol, they will choose to grow corn. Cellulosic ethanol from corn stover does not enter into any scenario because of the high cost of collecting and transporting corn stover over the large distances required to supply a commercial-sized ethanol facility.biofuels, corn acreage, crop prices, ethanol production, food prices, Resource /Energy Economics and Policy,

    Relationship between maternal methadone dose at delivery and neonatal abstinence syndrome.

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    OBJECTIVE: To estimate the relationship between maternal methadone dose and the incidence of neonatal abstinence syndrome (NAS). STUDY DESIGN: We performed a retrospective cohort study of pregnant women treated with methadone for opiate addiction who delivered live-born neonates between 1996 and 2006. Four dose groups, on the basis of total daily methadone dose, were compared (160 mg/d). The primary outcome was treatment for NAS. Symptoms of NAS were objectively measured with the Finnegan scoring system, and treatment was initiated for a score\u3e24 during the prior 24 hours. RESULTS: A total of 330 women treated with methadone and their 388 offspring were included. Average methadone dose at delivery was 117+/-50 mg/d (range, 20-340 mg/d). Overall, 68% of infants were treated for NAS. Of infants exposed to methadone doses160 mg/d, treatment for NAS was initiated for 68%, 63%, 70%, and 73% of neonates, respectively (P=.48). The rate of maternal illicit opiate abuse at delivery was 26%, 28%, 19%, and 11%, respectively (P=.04). CONCLUSION: No correlation was found between maternal methadone dose and rate of NAS. However, higher doses of methadone were associated with decreased illicit opiate abuse at delivery

    A mild synthesis of substituted 1,8-naphthyridines

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    A greener method for the synthesis of substituted 1,8-naphthyridines has been developed, which is supported by reaction metric analysis. Using 2-aminonicotinaldehyde as a starting material with a variety of carbonyl reaction partners, the Friedländer reaction can be performed with high yield using water as the reaction solvent. Divergent reactivity was seen when using acrolein, and an alternative method was developed to give access to 2-vinyl-1,8-naphthyridine in high yield, and an assessment of addition reactions to 2-vinyl-1,8-naphthyridine was performed

    Impact of long-term nitrogen deposition on the response of dune grassland ecosystems to elevated summer ozone

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    Nitrogen deposition and tropospheric ozone are important drivers of vegetation damage, but their interactive effects are poorly understood. This study assessed whether long-term nitrogen deposition altered sensitivity to ozone in a semi-natural vegetation community. Mesocosms were collected from sand dune grassland in the UK along a nitrogen gradient (5–25 kg N/ha/y, including two plots from a long-term experiment), and fumigated for 2.5 months to simulate medium and high ozone exposure. Ozone damage to leaves was quantified for 20 ozone-sensitive species. Soil solution dissolved organic carbon (DOC) and soil extracellular enzymes were measured to investigate secondary effects on soil processes. Mesocosms from sites receiving the highest N deposition showed the least ozone-related leaf damage, while those from the least N-polluted sites were the most damaged by ozone. This was due to differences in community-level sensitivity, rather than species-level impacts. The N-polluted sites contained fewer ozone-sensitive forbs and sedges, and a higher proportion of comparatively ozone-resistant grasses. This difference in the vegetation composition of mesocosms in relation to N deposition conveyed differential resilience to ozone. Mesocosms in the highest ozone treatment showed elevated soil solution DOC with increasing site N deposition. This suggests that, despite showing relatively little leaf damage, the ‘ozone resilient’ vegetation community may still sustain physiological damage through reduced capacity to assimilate photosynthate, with its subsequent loss as DOC through the roots into the soil. We conclude that for dune grassland habitats, the regions of highest risk to ozone exposure are those that have received the lowest level of long-term nitrogen deposition. This highlights the importance of considering community- and ecosystem-scale impacts of pollutants in addition to impacts on individual species. It also underscores the need for protection of ‘clean’ habitats from air pollution and other environmental stressors

    Real-Time Mobile Detection of Drug Use with Wearable Biosensors: A Pilot Study

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    While reliable detection of illicit drug use is paramount to the field of addiction, current methods involving self-report and urine drug screens have substantial limitations that hinder their utility. Wearable biosensors may fill a void by providing valuable objective data regarding the timing and contexts of drug use. This is a preliminary observational study of four emergency department patients receiving parenteral opioids and one individual using cocaine in a natural environment. A portable biosensor was placed on the inner wrist of each subject, to continuously measure electrodermal activity (EDA), skin temperature, and acceleration. Data were continuously recorded for at least 5 min prior to drug administration, during administration, and for at least 30 min afterward. Overall trends in biophysiometric parameters were assessed. Injection of opioids and cocaine use were associated with rises in EDA. Cocaine injection was also associated with a decrease in skin temperature. Opioid tolerance appeared to be associated with a blunted physiologic response as measured by the biosensor. Laterality may be an important factor, as magnitude of response varied between dominant and nondominant wrists in a single patient with bilateral wrist measurements. Changes in EDA and skin temperature are temporally associated with intravenous administration of opioids and cocaine; the intensity of response, however, may vary depending on history and extent of prior use.University of Massachusetts Medical School. Department of Emergency MedicineNational Institute on Drug AbuseNational Institutes of Health (U.S.) (Grant R01DA033769-01

    Scanning Electron Microscopy Analysis of Polyethylene Oxide Hydrogels for Blood Contact

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    Hydrogels are a class of synthetic material, composed of a polymer-water matrix and have been proposed as tissue substitutes and drug delivery vehicles. Polyethylene oxide (PEO) hydrogels were synthesized and used to produce coated wires and conduits for baboon blood compatibility studies. Blood-material interactions were studied both by Scanning Electron Microscopy (SEM) and 111In labeled platelet deposition. SEM processing modifications were first evaluated in order to reduce shrinkage and surface distortion incurred during sample preparation of these high water content materials. Pretreatment with 1% tannic acid reduced bulk shrinkage associated with critical point drying by 10-20%. This effect is small, nevertheless, it prevented major sample disruption. Coated guidewires were exposed to baboon blood for one hour in the inferior vena cava and conduits were placed for either 30 or 60 minutes in an ex vivo femoral arteriovenous shunt. Reference materials included Gore-tex®, polyethylene and silica-free polydimethyl siloxane (PDMS). In the guidewire studies, 111In labeled platelet levels were highest on Gore-tex® (6568.97 platelets/ 1000 μm2) and large thrombotic deposits were well visualized by SEM. Formulations containing PEO had low levels of platelet deposition and little evidence of platelet activation was noted by SEM. Shunt studies demonstrated that materials of high PEO content and molecular weight had the lowest levels of platelet deposition. After 60 minutes of blood flow, mean platelet deposition on PDMS and Gore-tex® was 50 and 1000 fold higher than on a network composed of 65% PEO 20,000 (p \u3c 0.05). SEM confirmed these findings
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