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51.
Chappell JC Song J Burke CW Klibanov AL Price RJ 《Small (Weinheim an der Bergstrasse, Germany)》2008,4(10):1769-1777
Therapeutic strategies in which recombinant growth factors are injected to stimulate arteriogenesis in patients suffering from occlusive vascular disease stand to benefit from improved targeting, less invasiveness, better growth-factor stability, and more sustained growth-factor release. A microbubble contrast-agent-based system facilitates nanoparticle deposition in tissues that are targeted by 1-MHz ultrasound. This system can then be used to deliver poly(D,L-lactic-co-glycolic acid) nanoparticles containing fibroblast growth factor-2 to mouse adductor muscles in a model of hind-limb arterial insufficiency. Two weeks after treatment, significant increases in both the caliber and total number of collateral arterioles are observed, indicating that the delivery of nanoparticles bearing fibroblast growth factor-2 by ultrasonic microbubble destruction may represent an effective and minimally invasive strategy for the targeted stimulation of therapeutic arteriogenesis. 相似文献
52.
Plants produce a variety of secondary metabolites that function as a defense against their natural enemies. Production of these secondary metabolites is genetically controlled, but is also phenotypically plastic and varies in response to both biotic and abiotic factors. Therefore, plant species may vary widely in their chemical defenses and such variation can be evident at temporal, spatial and tissue levels. Focusing on the chemical defenses of a native Colorado wildflower, Penstemon virgatus, we assessed the variation in iridoid glycoside (IG) content across two non-consecutive growing seasons, six natural populations and three tissue types: leaves, stems and flowers. Our results indicate that P. virgatus plants contain high concentrations of IGs (mean = 23.36% dry weight of leaves) and that IGs were differentially allocated among tissue types. Leaves contained the highest concentration of IGs, which varied quantitatively between sampling years, among plant populations, and plant parts. We also quantified leaf herbivore damage at all six populations but we found very little herbivore damage. Our study indicates that the IG concentrations of P. virgatus plants are both spatially and temporally variable. Furthermore, the high concentrations of secondary metabolites combined with the low levels of damage suggest that these plants are well defended against generalist herbivores. 相似文献
53.
Benjamin P. Jacot Caitlin T. Mueller 《Structural and Multidisciplinary Optimization》2017,55(5):1819-1829
In the design of discrete structures such as trusses and frames, important quantitative goals such as minimal weight or minimal compliance often dominate. Many numerical techniques exist to address these needs. However, an analytical approach exists to meet similar goals, which was initiated by Michell (1904) and has been mostly used for two-dimensional structures so far. This paper develops a method to extend the existing mainly two-dimensional approach to apply to three-dimensional structures. It will be referred as the Michell strain tensor method (MSTM). First, the proof that MSTM is consistent with the existing theory in two dimensions is provided. Second, two- and three-dimensional known solutions will be replicated based on MSTM. Finally, MSTM will be used to solve new three-dimensional cases. 相似文献
54.
Yactayo-Chang Jessica P. Mendoza Jorrel Willms Steven D. Rering Caitlin C. Beck John J. Block Anna K. 《Journal of chemical ecology》2021,47(8-9):799-809
Journal of Chemical Ecology - Fall armyworm (Spodoptera frugiperda) is a major global pest of many crops, including maize (Zea mays). This insect is known to use host plant-derived volatile organic... 相似文献
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56.
Comments on the original article, "Rethinking the concept of acculturation: Implications for theory and research," by S. J. Schwartz, J. B. Unger, B. L. Zamboanga, and J. Szapocznik (see record 2010-08987-001). Schwartz et al are to be commended for their attempts “to propose an expanded, multidimensional model of acculturation and of the demographic and contextual forces that can influence the acculturation process” (p. 238). In their article, they called attention to key factors such as the generational status of immigrants and their children; the role of location, particularly in ethnic enclaves; and the context of reception that immigrants enter, including the potential discrimination they may face. These variables are the crucial backdrop for the authors’ call to “focus on the higher order construct of receiving-culture acquisition as well as on the individual dimensions of this higher order construct—practices, values, and identifications” (p. 246). As a sociologist trained in social psychology, I am pleased by their incorporation of some of the sociological literature on these processes. However, I was surprised by important gaps in their discussion of Portes and Rumbaut’s (1996, 2006) work and by their neglect of one of the most widely used terms employed by sociologists to hypothesize outcomes for the very questions Schwartz et al were posing. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
57.
Resch J. Aaron; Villarreal Victor; Johnson Caitlin L.; Elliott Timothy R.; Kwok Oi-Man; Berry Jack W.; Underhill Andrea T. 《Canadian Metallurgical Quarterly》2009,54(1):51
Objectives: The trajectories of life satisfaction for 609 individuals who sustained a traumatic brain injury (TBI) were studied. Hierarchical linear modeling analysis examined individual level growth trends over the first 5 years following TBI using gender, functional independence, age, and time to estimate life satisfaction trajectories. Measures: Participants completed the Functional Independence Measure and the Life Satisfaction Inventory at years 1, 2, 4, and 5 after sustaining TBI. Results: Participants who reported higher functional independence at year 1 also had higher life satisfaction at year 1. Participants with lower functional independence across the 5-year period had life satisfaction trajectories that decreased at significantly greater rates than the individuals with more functional independence. The life satisfaction trajectory declined for the sample, but participants reporting lower cognitive and motor functional independence had significantly greater declines in life satisfaction trajectories. Age and gender were not significant factors in predicting life satisfaction trajectories following TBI. Implications: Individuals with greater cognitive and motor impairments following TBI are likely to experience significant declines in life satisfaction within 5 years of living with TBI. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
58.
Johnson Caitlin L.; Resch J. Aaron; Elliott Timothy R.; Villarreal Victor; Kwok Oi-Man; Berry Jack W.; Underhill Andrea T. 《Canadian Metallurgical Quarterly》2010,55(2):180
Objectives: Examined the influence of functional impairment, stable marital status, and family satisfaction on life satisfaction trajectories for 609 individuals (435 men, 174 women) over the first 5 years after traumatic brain injury (TBI). Measures: Participants completed the Family Satisfaction Scale (FSS), Functional Independence Measure (FIM), and the Life Satisfaction Index (LSI) at years 1, 2, 4, and 5 after sustaining a TBI. Results: Trajectory modeling revealed that higher family satisfaction was associated with increases in life satisfaction for individuals with less functional impairment. Stable marital status was not significantly associated with life satisfaction trajectories. Implications: Family satisfaction appears to have pronounced beneficial effects on life satisfaction for persons with less functional impairment after TBI regardless of marital status. In contrast, a stable marriage appears to have no apparent benefits to self-reported life satisfaction over the first 5 years post-TBI. Theoretical and clinical implications of these results are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
59.
Toomey Russell B.; Ryan Caitlin; Diaz Rafael M.; Card Noel A.; Russell Stephen T. 《Canadian Metallurgical Quarterly》2010,46(6):1580
Past research documents that both adolescent gender nonconformity and the experience of school victimization are associated with high rates of negative psychosocial adjustment. Using data from the Family Acceptance Project's young adult survey, we examined associations among retrospective reports of adolescent gender nonconformity and adolescent school victimization due to perceived or actual lesbian, gay, bisexual, or transgender (LGBT) status, along with current reports of life satisfaction and depression. The participants included 245 LGBT young adults ranging in age from 21 to 25 years. Using structural equation modeling, we found that victimization due to perceived or actual LGBT status fully mediates the association between adolescent gender nonconformity and young adult psychosocial adjustment (i.e., life satisfaction and depression). Implications are addressed, including specific strategies that schools can implement to provide safer environments for gender-nonconforming LGBT students. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
60.
Fuchs Lynn S.; Fuchs Douglas; Craddock Caitlin; Hollenbeck Kurstin N.; Hamlett Carol L.; Schatschneider Christopher 《Canadian Metallurgical Quarterly》2008,100(3):491
This study assessed the effects of small-group tutoring with and without validated classroom instruction on at-risk students' math problem solving. Stratifying within schools, 119 3rd-grade classes were randomly assigned to conventional or validated problem-solving instruction (Hot Math, schema-broadening instruction). Students identified as at risk (n=243) were randomly assigned, within classroom conditions, to receive or not receive Hot Math tutoring. Students were tested on problem-solving and math applications measures before and after 16 weeks of intervention. Analyses of variance, which accounted for the nested structure of the data, revealed that the tutored students who received validated classroom instruction achieved better than the tutored students who received conventional classroom instruction (effect size=1.34). However, the advantage for tutoring over no tutoring was similar whether students received validated or conventional classroom instruction (effect sizes=1.18 and 1.13). Tutoring, not validated classroom instruction, reduced the prevalence of math difficulty. Implications for responsiveness-to-intervention prevention models and for enhancing math problem-solving instruction are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献