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991.
Whalen Carol K.; Odgers Candice L.; Reed Preston L.; Henker Barbara 《Canadian Metallurgical Quarterly》2011,25(3):402
It is well known that parents of children with attention-deficit/hyperactivity disorder (ADHD) experience elevated levels of caregiver stress, but little is known about the ebb and flow of parental distress as it happens, or the degree of synchrony between short-term oscillations in child behaviors and maternal distress. Electronic diaries (eDiaries) were used to dissect daily distress in natural settings. Across 7 days during nonschool hours, half-hourly eDiaries were completed independently by mothers and their 8- to 12-year-old children (51 receiving medication for ADHD and 58 comparison peers). Diary items tapped behaviors, moods, and contexts, with children reporting their own behaviors and mothers reporting on themselves and their children. Maternal distress and child ADHD-type behaviors exhibited moderate to strong associations “in the moment,” whether child behaviors were reported by mothers or children. This mother-child synchrony emerged for the comparison as well as the ADHD group, although the associations were stronger when the dyad included a child with ADHD. Because fixed-effects analyses were conducted, these patterns are not attributable to levels of psychopathology or other stable individual differences in mothers or children. Further moderation analyses revealed that the links between child behaviors and maternal distress were strengthened by maternal risk and attenuated by child behavioral self-esteem; these effects were modest but detectable. These findings can help guide not only interventions targeted on improving quality of life in families of children with ADHD, but also programs designed to help all parents identify and manage their own parenting stressors. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
992.
Clark Luke; Dombrovski Alexander Y.; Siegle Greg J.; Butters Meryl A.; Shollenberger Cori L.; Sahakian Barbara J.; Szanto Katalin 《Canadian Metallurgical Quarterly》2011,26(2):321
Suicidal behavior is a potentially lethal complication of late-life depression. In younger adults, suicide has been linked to abnormal decision-making ability. Given that there are substantial age-related decreases in decision-making ability, and that older adults experience environmental stressors that require effective decision-making, we reasoned that impaired decision-making may be particularly relevant to suicidal behavior in the elderly. We thus compared performance on a probabilistic decision-making task that does not involve working memory (“Cambridge Gamble Task”) in four groups of older adults: (1) individuals with major depression and a history of suicide attempt (n = 25), (2) individuals with major depression with active suicidal ideation but no suicide attempt (n = 13), (3) individuals with major depression without suicidality (n = 35), and (4) nondepressed control subjects (n = 22). There was a significant effect of group on quality of decision-making, whereby the suicide attempters exhibited poorer ability to choose the likely outcome, compared with the nonsuicidal depressed and nondepressed comparison subjects. There were no group differences in betting behavior. The suicide attempters differed in several aspects of social problem-solving on a self-report scale. Quality of decision-making was negatively correlated with the score on the impulsive/careless problem-solving subscale. These data suggest that older suicide attempters have a deficit in risk-sensitive decision-making, extending observations in younger adults. More specifically, older suicide attempters seem to neglect outcome probability and make poor choices. These impairments may precipitate and perpetuate suicidal crisis in depressed elders. Identification of decision-making impairment in suicidal elders may help with designing effective interventions. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
993.
Yun Pan Keqiang Lai Yuxia Fan Chunying Li Lu Pei Barbara A. Rasco Yiqun Huang 《Journal of food science》2014,79(6):T1225-T1230
Monitoring the level of tert‐butylhydroquinone (TBHQ), a permissible antioxidant additive in edible vegetable oils in many countries, is important to ensure that oils and products that contain them comply with the relevant import regulations. Surface‐enhanced Raman spectroscopy (SERS) technology coupled with chemometric methods including partial least squares (PLS) and support vector machine (SVM) regression was applied to determine levels of TBHQ in spiked corn oils (0 to 500 mg/kg, n = 40) and commercial vegetable oils (0 to 99.7 mg/kg, n = 25). The lowest detectable concentration was 5 mg/L for TBHQ in standard solutions and 10 mg/kg of TBHQ in vegetable oils from various plant sources. The TBHQ levels predicted by the PLS or SVM model had a high correlation with actual TBHQ levels in commercial oil samples (SVM: R2 = 0.972, ratio of performance to deviation [RPD] = 5.55, root mean square error [RMSE] = 5.73 mg/kg; PLS: R2 = 0.976, RPD = 6.43, RMSE = 4.94 mg/kg), indicating great potential of SERS methods for detection and quantification of TBHQ in oils from a variety of sources. 相似文献
994.
Igho Onakpoya Katherine Hunt Barbara Wider Edzard Ernst 《Critical reviews in food science and nutrition》2014,54(1):17-23
Background : Several slimming aids being sold as food supplements are widely available. One of them is pyruvate. Its efficacy in causing weight reduction in humans has not been fully established. The objective of this systematic review was to examine the efficacy of pyruvate in reducing body weight. Methods: Electronic and nonelectronic searches were conducted to identify all relevant human randomized clinical trials. The bibliographies of all located articles were also searched. No restrictions in language or time were applied. Two independent reviewers extracted the data according to predefined criteria. A fixed-effect model was used to calculate mean differences (MD) and 95% confidence interval (CI). Results: Nine trials were identified and 6 were included. All had methodological weaknesses. The meta-analysis revealed a statistically significant difference in body weight with pyruvate compared to placebo (MD: ?0.72 kg; 95% CI: ?1.24 to ?0.20). The magnitude of the effect is small, and its clinical relevance is uncertain. Adverse events included gas, bloating, diarrhea, and increase in low-density lipoprotein (LDL) cholesterol. Conclusion: The evidence from randomized clinical trials does not convincingly show that pyruvate is efficacious in reducing body weight. Limited evidence exists about the safety of pyruvate. Future trials involving the use of this supplement should be more rigorous and better reported. 相似文献
995.
Abstract La0,5Sr0,5CoO3 (LSCO) thin films were prepared from water solutions of lanthanum nitrate La(NO3)3x6H2O, strontium nitrate Sr(NO3)2 and cobalt nitrate Co(NO3)2x6H2O with different amounts of polyvinylalcohol (PVA). Thin films were deposited on platinum coated and thermally oxidized silicon substrates. The influence of the amount of PVA on the thermal decomposition of LSCO precursors, the surface wetting and the microstructure of LSCO thin films were investigated. The effort was also focused on the optimization of the thermal treatment to obtain dense LSCO thin films. 相似文献
996.
Sara Tomaselli Barbara Bonamassa Anna Alisi Valerio Nobili Franco Locatelli Angela Gallo 《International journal of molecular sciences》2013,14(11):22796-22816
Adenosine deaminase acting on RNA (ADAR) enzymes convert adenosine (A) to inosine (I) in double-stranded (ds) RNAs. Since Inosine is read as Guanosine, the biological consequence of ADAR enzyme activity is an A/G conversion within RNA molecules. A-to-I editing events can occur on both coding and non-coding RNAs, including microRNAs (miRNAs), which are small regulatory RNAs of ~20–23 nucleotides that regulate several cell processes by annealing to target mRNAs and inhibiting their translation. Both miRNA precursors and mature miRNAs undergo A-to-I RNA editing, affecting the miRNA maturation process and activity. ADARs can also edit 3′ UTR of mRNAs, further increasing the interplay between mRNA targets and miRNAs. In this review, we provide a general overview of the ADAR enzymes and their mechanisms of action as well as miRNA processing and function. We then review the more recent findings about the impact of ADAR-mediated activity on the miRNA pathway in terms of biogenesis, target recognition, and gene expression regulation. 相似文献
997.
Gasser M Wick P Clift MJ Blank F Diener L Yan B Gehr P Krug HF Rothen-Rutishauser B 《Particle and fibre toxicology》2012,9(1):17-13
ABSTRACT: BACKGROUND: Increasing concern has been expressed regarding the potential adverse health effects that may be associated with human exposure to inhaled multi-walled carbon nanotubes (MWCNTs). Thus it is imperative that an understanding as to the underlying mechanisms and the identification of the key factors involved in adverse effects are gained. In the alveoli, MWCNTs first interact with the pulmonary surfactant. At this interface, proteins and lipids of the pulmonary surfactant bind to MWCNTs, affecting their surface characteristics. Aim of the present study was to investigate if the pre-coating of MWCNTs with pulmonary surfactant has an influence on potential adverse effects, upon both (i) human monocyte derived macrophages (MDM) monocultures, and (ii) a sophisticated in vitro model of the human epithelial airway barrier. Both in vitro systems were exposed to MWCNTs either pre-coated with a porcine pulmonary surfactant (Curosurf) or not. The effect of MWCNTs surface charge was also investigated in terms of amino (NH2) and carboxyl (COOH) surface modifications. RESULTS: Pre-coating of MWCNTs with Curosurf affects their oxidative potential by increasing the reactive oxygen species levels and decreasing intracellular glutathione depletion in MDM as well as decreases the release of Tumour necrosis factor alpha (TNF-alpha). In addition, an induction of apoptosis was observed after exposure to Curosurf pre-coated MWCNTs. In triple cell-co cultures the release of Interleukin-8 (IL-8) was increased after exposure to Curosurf pre-coated MWCNTs. Effects of the MWCNTs functionalizations were minor in both MDM and triple cell co-cultures. CONCLUSIONS: The present study clearly indicates that the pre-coating of MWCNTs with pulmonary surfactant more than the functionalization of the tubes is a key factor in determining their ability to cause oxidative stress, cytokine/chemokine release and apoptosis. Thus the coating of nano-objects with pulmonary surfactant should be considered for future lung in vitro risk assessment studies. 相似文献
998.
Barbara Lothenbach Gwenn Le Saout Mohsen Ben Haha Renato Figi Erich Wieland 《Cement and Concrete Research》2012,42(2):410-423
The hydration of a low-alkali cement based on CEM III/B blended with 10 wt.% of nanosilica has been studied. The nanosilica reacted within the first days and 90% of the slag reacted within 3.5 years. C-S-H (Ca/Si ~ 1.2, Al/Si ~ 0.12), calcite, hydrotalcite, ettringite and possibly strätlingite were the main hydrates. The pore water composition revealed ten times lower alkali concentrations than in Portland cements. Reducing conditions (HS?) and a pH value of 12.2 were observed. Between 1 month and 3.5 years of hydration more hydrates were formed due to the ongoing slag reaction but no significant differences in the composition of the pore solution or solid phase assemblage were observed.On the basis of thermodynamic calculations it is predicted that siliceous hydrogarnet could form in the long-term and, in the presence of siliceous hydrogarnet, also thaumasite. Nevertheless, even after 3.5 year hydration, neither siliceous hydrogarnet nor thaumasite have been observed. 相似文献
999.
Florian Deschner Frank Winnefeld Barbara Lothenbach Sebastian Seufert Peter Schwesig Sebastian Dittrich Friedlinde Goetz-Neunhoeffer Jürgen Neubauer 《Cement and Concrete Research》2012,42(10):1389-1400
The effects of two different low calcium fly ashes on the hydration of ordinary Portland cement (OPC) pastes containing 50 wt.% of fly ash were investigated over a hydration time of 550 days. The results were compared with a reference blend of OPC containing 50 wt.% of inert quartz powder allowing the distinction between "filler effect" and pozzolanic reaction.Until 2 days, no evidence of fly ash reaction was measured and its influence on the hydration is mainly related to the “filler effect”. From 7 days on, the effects of the pozzolanic reaction were observed by the consumption of portlandite, the change of the pore solution chemistry, the formation of a presumably water-rich inner hydration product and the change of the C–S–H composition towards higher Al/Si ratio compared to the C–S–H of neat OPC. Additional strength due to the pozzolanic reaction developed after 28 days of hydration. 相似文献
1000.
Barbara Natalie Unger Alexander Kock Hans Georg Gemünden Daniel Jonas 《International Journal of Project Management》2012
Project portfolios are vehicles for strategy implementation. Senior management should terminate projects no longer conforming to corporate strategy in order to ensure strategic fit. This paper investigates how rigorous termination of bad and troubled projects affects portfolio effectiveness and senior management's decisive role in this context. We introduce the concept of project termination quality, analyse its consequences for strategic fit and how it is affected by senior management involvement. Using a quantitative longitudinal study of a sample of project portfolios, we show that termination quality positively affects strategic fit. We also show a positive, but inverted u-shaped relationship between senior management involvement and termination quality. We conclude that there is an optimal degree of involvement, beyond which an additional involvement of senior managers results in negative effects. 相似文献