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Attachment Behavior (attachment + behavior)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Kinetics of microbubble,solid surface interaction and attachment

AICHE JOURNAL, Issue 4 2003
Chun Yang
Microbubble,solid surface interaction and attachment under the influence of hydrodynamic and physicochemical forces were studied experimentally and theoretically. An impinging-jet technique was developed to measure bubble-attachment flux onto a flat solid surface in an impinging-jet stagnation flow. A video imaging system enables direct observation of the attachment behavior of hydrogen microbubbles onto two different collector surfaces: hydrophilic untreated glass and hydrophobic methylated glass. Experimental results showed that the attachment flux depends on both hydrodynamic flow and electrolyte concentration. A mass-transfer model developed computes bubble-attachment flux, considering hydrodynamic convection, Brownian diffusion, migration under gravitational buoyancy, and DLVO surface forces (that is, van der Waals and electric double-layer forces). At high flow rates, the numerical predictions for attachment rates onto methylated glass generally agreed well with the experimental data. However, a difference exists between theoretical and experimentally determined attachment rates for both untreated and methylated glass when the Reynolds number of the flow is low. Several mechanisms are proposed to account for this discrepancy. [source]

Behavior of human periodontal ligament cells on CO2 laser irradiated dentinal root surfaces: an in vitro study

JOURNAL OF PERIODONTAL RESEARCH, Issue 6 2004
V. Pant
Objective:, The aim of this study was to investigate the in vitro attachment behavior of human periodontal ligament fibroblasts on periodontally involved root surface after conditioning with CO2 laser and to compare its efficacy with chemical conditioning agents, namely tetracycline hydrochloride, citric acid, hydrogen peroxide (H2O2) and EDTA, using scanning electron microscopy. Methods:, A total of 84 scaled and root-planed specimens from periodontally involved single-rooted human teeth showing hopeless prognosis were selected and assigned to two groups. One group was lased with a CO2 laser (from 5 cm at 3 W for 0.8, 1.0 and 1.2 s), and the other group was treated with either tetracycline hydrochloride (2.5%), citric acid (saturated solution, pH 1), H2O2 (6%) or EDTA (5%; pH 7.4) for 3 min. The specimens were then seeded with human periodontal ligament fibroblasts, incubated for either 12 h or 24 h, and then the cell attachment behavior was observed. Results:, CO2 laser irradiation for 1.0 s was found to be the most efficient, showing consistently good cell attachment with the highest mean value (15.00 ± 3.41 cells/10,000 µm2 after incubation for 12 h and 29.17 ± 2.04 cells/10,000 µm2 after 24 h), followed by irradiation for 0.8 s (13.11 ± 3.04 cells/10,000 µm2 after incubation for 12 h and 22.91 ± 7.10 cells/10,000 µm2 after 24 h). Charring was observed following irradiation for 1.2 s. Amongst chemical conditioning agents, citric acid was found to be the most efficient, with a mean cell attachment of 17.82 ± 2.16 cells/10,000 µm2 after incubation for 12 h and 23.62 ± 1.94 cells/10,000 µm2 after 24 h. EDTA and H2O2 did not do well in the study. Conclusion:, The results suggest that CO2 laser irradiation for 1.0 s may promote comparatively better attachment of periodontal ligament fibroblast on dentinal root surfaces than the conventional chemical conditioning agents used in the study. [source]

Physical sequelae and self-perceived attachment in adult survivors of childhood cancer

PSYCHO-ONCOLOGY, Issue 4 2001
David Joubert
The association between the physical sequelae of childhood cancer and self-reported attachment behavior was investigated in 97 adult survivors. Attachment was assessed using standardized self-report questionnaires. Functional disability and cosmetic sequelae of the cancer and its treatment were evaluated by the attending oncologist using a standardized rating scale. Results suggest that attachment is not significantly associated with physician-rated physical sequelae, but may be related to the time of onset of the functional deficits, independent of the current age or age at diagnosis. Further, survivors with functional sequelae in adulthood describe themselves as more insecure in their relationships in general and more ambivalent in their relationship with their parents. These findings, if replicated, suggest that the duration of the functional deficits as well as the developmental stage of the individual when they began may be important variables which affect the survivor's capacity to develop and maintain intimate relationships that are secure and satisfying. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Improvements in early care in Russian orphanages and their relationship to observed behaviors

INFANT MENTAL HEALTH JOURNAL, Issue 2 2005
Christina J. Groark
This article describes a unique study that attempts to promote positive social-emotional relationships and attachment between caregivers and children in orphanages in St. Petersburg, Russia. The children who reside in these orphanages are typically between birth and 48 months of age; approximately 50% are diagnosed with disabilities, and approximately 60% leave through foreign adoption. Initially, their orphanage caregivers showed a high level of current anxiety and depression and were detached from and communicated little with the children. Likewise, during baseline observations, the children demonstrated poor attachment behaviors such as indiscriminant friendliness, lack of eye contact with adults, aggression, and impulsive behavior. Two interventions were used in a quasiexperimental design: (a) training of caregivers to promote warm, responsive caregiving and (b) staffing and structural alterations to support relationship building, especially increasing the consistency of caregivers. The methodology required that both the training and staffing interventions be provided to one orphanage, only the training to a second, and neither to a third. (At any one time, ns = 80,120 in each condition.) Initial informal observations reveal positive behaviors for both the caregivers and the children, such as increased two-way conversations, animated and enthusiastic emotional responses, and positive social and language interactions. Early data analyses show an increase in the consistency and stability of caregivers and increased scores for caregivers on every subscale of the HOME Scales. Children showed improvements in physical growth, cognition, language, motor, personal-social, and affect, with children having severe disabilities improving the most. The implications of these findings suggest that training staff with modest educational backgrounds and structural changes are effective, can increase socially responsive caregiving behaviors, and improves social interactions of children, at least temporarily. ©2005 Michigan Association for Infant Mental Health. [source]