Validity, Reliability, and Measurement Invariance of the Diabetes Stress Questionnaire-Short Form.

OBJECTIVE: The purpose of this study was to develop a short form of the Diabetes Stress Questionnaire (DSQ) with adequate psychometric properties (i.e., internal consistency, convergent, criterion, discriminant validity, construct validity, and measurement invariance). METHODS: In total, 181 youth with type 1 diabetes (T1D) completed the 65-item DSQ, and archival data were obtained from 142 youth with T1D to serve as an independent cross-validation sample. Twenty-four items were chosen to retain the original eight scales of the DSQ and to maximize internal consistency and correlations to full subscales. Confirmatory factor analyses were used to evaluate the proposed factor structure of the Diabetes Stress Questionnaire-Short Form (DSQ-SF) and to assess invariance of the DSQ-SF across sex, race, grade level, glycemic control, illness duration, and annual income categories. RESULTS: The 24-item DSQ-SF was found to have good internal consistency, factor structure and fit, correlated highly to the full scale (r = .98), and was invariant across sex, race, grade level (<9th grade or >9th grade), glycemic control, illness duration, and annual income. CONCLUSIONS: The DSQ-SF appears to be a psychometrically robust measure of diabetes-specific stress in youth with T1D. Present findings suggest that the DSQ-SF has the potential to be a useful, quick, cost-effective, and comprehensive screening tool for identifying youth with T1D who may benefit from T1D-specific stress reduction interventions as a way to improve health behaviors, psychosocial well-being, and glycemic control.

Dielectrophoretic trapping of nanoparticles with an electrokinetic nanoprobe.

A high aspect ratio 3D electrokinetic nanoprobe is used to trap polystyrene particles (200 nm), gold nanoshells (120 nm), and gold nanoparticles (mean diameter 35 nm) at low voltages (<1 V(rms)). The nanoprobe is fabricated using room temperature self-assembly methods, without the need for nanoresolution lithography. The nanoprobe (150-500 nm in diameter, 2-150 µm in length) is mounted on the end of a glass micropipette, enabling user-specified positioning. The nanoprobe is one electrode within a point-and-plate configuration, with an indium-tin oxide cover slip serving as the planar electrode. The 3D structure of the nanoprobe enhances dielectrophoretic capture; further, electro-hydrodynamic flow enhances trapping, increasing the effective trapping region. Numerical simulations show low heating (1 K), even in biological media of moderate conductivity (1 S/m).