333 research outputs found

    Secondary lithium cells for space applications

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    It is concluded that secondary lithium batteries are suitable for planetary missions requiring high specific energy, long active shelf life, and limited cycle life. Titanium disulfide cathode material meet all the requirements for rechargeable lithium cell, including high intrinsic reversibility and realizable specific energy. Secondary lithium technology is still evolving, although low capacity cells have been demonstrated and greater than 700 cycle life was achieved. Work is in progress to improve the cycle life and safety of the electrolytes, alternate lithium anode, and the separators

    Status of the development of rechargeable lithium cells

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    The progress in the development of the ambient temperature lithium - titanium disulfide rechargeable cell under development at the Jet Propulsion Laboratory is described in this paper. Originally aimed at achieving a specific energy of 100 Wh/kg, 'AA' cells have demonstrated 125 Wh/kg at the C/3 discharge rate. The results of evaluating cell design parameters are discussed and cycling test data are also included in the paper. Safety tests results at various over-charge and over discharge conditions and rates proved to be uneventful. The test results of cell with built-in overcharge mechanism proved the concept was feasible. Replacing the lithium foil electrode with a Li(x)C resulted in a capacity at 1mA/cm(exp 2) of 200 mAh/gm and 235 mAh/gm at 0.167 mA

    Design considerations for rechargeable lithium batteries

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    Viewgraphs of a discussion of design considerations for rechargable lithium batteries. The objective is to determine the influence of cell design parameters on the performance of Li-TiS2 cells. Topics covered include cell baseline design and testing, cell design and testing, cell design parameters studies, and cell cycling performance

    Breit Hamiltonian and QED Effects for Spinless Particles

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    We describe a simplified derivation for the relativistic corrections of order α4\alpha^4 for a bound system consisting of two spinless particles. We devote special attention to pionium, the bound system of two oppositely charged pions. The leading quantum electrodynamic (QED) correction to the energy levels is of the order of α3\alpha^3 and due to electronic vacuum polarization. We analyze further corrections due to the self-energy of the pions, and due to recoil effects, and we give a complete result for the scalar-QED leading logarithmic corrections which are due to virtual loops involving only the scalar constituent particles (the pions); these corrections are of order α5lnα\alpha^5 \ln \alpha for S states.Comment: 12 pages, LaTeX; references added (J. Phys. B, in press

    Lying Behavior, Family Functioning and Adjustment in Early Adolescence

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    Item does not contain fulltextCommunication between children and parents has been the subject of several studies, examining the effects of, for example, disclosure and secrecy on adolescents' social relationships and adjustment. Less attention has paid to adolescent deception. We developed and tested a new instrument on lying behavior in a sample of 671 parent-adolescent couples. Analyses on the psychometric properties showed that this instrument had one principal component, and high internal consistency, item-total correlations and inter-item correlations. Lying was moderately associated with other indicators of parent-child communication, the quality of the parent-child relationship, and with parenting practices. In addition, frequent lying was moderately related to behavioral problems and emotional problems.10 p

    Process interventions for vaccine injections: Systematic review of randomized controlled trials and quasi-randomized controlled trials

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    Background: This systematic review evaluated the effectiveness of process interventions (education for clinicians, parent presence, education of parents [before and on day of vaccination], and education of patients on day of vaccination) on reducing vaccination pain, fear, and distress and increasing the use of interventions during vaccination. Design/Methods: Databases were searched using a broad search strategy to identify relevant randomized and quasi-randomized controlled trials. Critical outcomes were pain, fear, distress (when applicable), and use of pain management interventions. Data were extracted according to procedure phase (preprocedure, acute, recovery, combinations of these) and pooled using established methods. Analyses were conducted using standardized mean differences (SMD) and risk ratios (RR). Results: Thirteen studies were included. Results were generally mixed. On the basis of low to very low-quality evidence, the following specific critical outcomes showed significant effects suggesting: (1) clinicians should be educated about vaccine injection pain management (use of interventions: SMD 0.66; 95% confidence interval [CI]: 0.47, 0.85); (2) parents should be present (distress preprocedure: SMD -0.85; 95% CI: -1.35, -0.35); (3) parents should be educated before the vaccination day (use of intervention preprocedure: SMD 0.83; 95% CI: 0.25, 1.41 and RR, 2.08; 95% CI: 1.51, 2.86; distress acute: SMD, -0.35; 95% CI: -0.57, -0.13); (4) parents should be educated on the vaccination day (use of interventions: SMD 1.02; 95% CI: 0.22, 1.83 and RR, 2.42; 95% CI: 1.47, 3.99; distress preprocedure+acute+ recovery: SMD -0.48; 95% CI: -0.82, -0.15); and (5) individuals 3 years of age and above should be educated on the day of vaccination (fear preprocedure: SMD -0.67; 95% CI: -1.28, -0.07). Conclusions: Educating individuals involved in the vaccination procedure (clinicians, parents of children being vaccinated; individuals above 3 y of age) is beneficial to increase use of pain management strategies, reduce distress surrounding with vaccination, and to reduce fear. When possible, parent presence is also recommended for children undergoing vaccination

    Psychological interventions for vaccine injections in children and adolescents: Systematic review of randomized and quasi-randomized controlled trials

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    Background: This systematic review evaluated the effectiveness of psychological interventions for reducing vaccination pain and related outcomes in children and adolescents. Design/Methods: Database searches identified relevant randomized and quasi-randomized controlled trials. Data were extracted and pooled using established methods. Pain, fear, and distress were considered critically important outcomes. Results: Twenty-two studies were included; 2 included adolescents. Findings showed no benefit of false suggestion (n=240) for pain (standardized mean difference [SMD] -0.21 [-0.47, 0.05]) or distress (SMD -0.28 [-0.59, 0.11]), or for use of repeated reassurance (n=82) for pain (SMD -0.18 [-0.92, 0.56]), fear (SMD -0.18 [-0.71, 0.36]), or distress (SMD 0.10 [-0.33, 0.54]). Verbal distraction (n=46) showed reduced distress (SMD -1.22 [-1.87, -0.58]), but not reduced pain (SMD -0.27 [-1.02, 0.47]). Similarly, video distraction (n=328) showed reduced distress (SMD -0.58 [-0.82, -0.34]), but not reduced pain (SMD -0.88 [-1.78, 0.02]) or fear (SMD 0.08 [-0.25, 0.41]). Music distraction demonstrated reduced pain when used with children (n=417) (SMD -0.45 [-0.71, -0.18]), but not with adolescents (n=118) (SMD -0.04 [-0.42, 0.34]). Breathing with a toy (n=368) showed benefit for pain (SMD -0.49 [-0.85, -0.13]), but not fear (SMD -0.60 [-1.22, 0.02]); whereas breathing without a toy (n=136) showed no benefit for pain (SMD -0.27 [-0.61, 0.07]) or fear (SMD -0.36 [-0.86, 0.15]). There was no benefit for a breathing intervention (cough) in children and adolescents (n=136) for pain (SMD -0.17 [-0.41, 0.07]). Conclusions: Psychological interventions with some evidence of benefit in children include: verbal distraction, video distraction, music distraction, and breathing with a toy

    HELPinKids & Adults knowledge synthesis of the management of vaccination pain and high levels of needle fear limitations of the evidence and recommendations for future research

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    The HELPinKids&Adults knowledge synthesis for the management of vaccination-related pain and high levels of needle fear updated and expanded upon the 2010 HELPinKIDS knowledge synthesis and clinical practice guideline for pain mitigation during vaccine injections in childhood. Interventions for vaccine pain management in adults and treatment of individuals with high levels of needle fear, phobias, or both were included, thereby broadening the reach of this work. The present paper outlines the overarching limitations of this diverse evidence base and provides recommendations for future research. Consistent with the framing of clinical questions in the systematic reviews, the Participants, Intervention, Comparison, Outcome, Study design (PICOAS) framework was used to organize these predominant issues and research directions. The major limitations we identified across systematic reviews were an overall dearth of trials on vaccination, lack of methodological rigor, failure to incorporate important outcomes, poor study reporting, and various sources of heterogeneity. Future research directions in terms of conducting additional trials in the vaccination context, improving methodological quality and rigor, assessment of global acceptability and feasibility of interventions, and inclusion of outcomes that stakeholders consider to be important (eg, compliance) are recommended. Given concerns about pain and fear are known contributors to vaccine hesitancy, improving and expanding this evidence base will be integral to broader efforts to improve vaccine compliance and public health worldwide

    Interventions for individuals with high levels of needle fear: Systematic review of randomized controlled trials and quasi-randomized controlled trials

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    Background: This systematic review evaluated the effectiveness of exposure-based psychological and physical interventions for the management of high levels of needle fear and/or phobia and fainting in children and adults. Design/Methods: A systematic review identified relevant randomized and quasi-randomized controlled trials of children, adults, or both with high levels of needle fear, including phobia (if not available, then populations with other specific phobias were included). Critically important outcomes were self-reported fear specific to the feared situation and stimulus (psychological interventions) or fainting (applied muscle tension). Data were pooled using standardized mean difference (SMD) or relative risk with 95% confidence intervals. Results: The systematic review included 11 trials. In vivo exposurebased therapy for children 7 years and above showed benefit on specific fear (n=234; SMD: -1.71 [95% CI: -2.72, -0.7]). In vivo exposure-based therapy with adults reduced fear of needles posttreatment (n=20; SMD: -1.09 [-2.04, -0.14]) but not at 1-year follow-up (n=20; SMD: -0.28 [-1.16, 0.6]). Compared with single session, a benefit was observed for multiple sessions of exposure-based therapy posttreatment (n=93; SMD: -0.66 [-1.08, -0.24]) but not after 1 year (n=83; SMD: -0.37 [-0.87, 0.13]). Non in vivo e.g., imaginal exposure-based therapy in children reduced specific fear posttreatment (n=41; SMD: -0.88 [-1.7, -0.05]) and at 3 months (n=24; SMD: -0.89 [-1.73, -0.04]). Non in vivo exposure-based therapy for adults showed benefit on specific fear (n=68; SMD: -0.62 [-1.11, -0.14]) but not procedural fear (n=17; SMD: 0.18 [-0.87, 1.23]). Applied tension showed benefit on fainting posttreatment (n=20; SMD: -1.16 [-2.12, -0.19]) and after 1 year (n=20; SMD: -0.97 [-1.91, -0.03]) compared with exposure alone. Conclusions: Exposure-based psychological interventions and applied muscle tension show evidence of benefit in the reduction of fear in pediatric and adult populations
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