Maternal Beliefs Surrounding Infant Feeding, but Not Maternal BMI or Hospital Experience, Predict Breastfeeding Exclusivity and Behavior.

BACKGROUND: Overweight/Obese (OW/Ob) women are at risk for breastfeeding failure. How maternal BMI affects lactation support received in-hospital, or maternal attitudes and beliefs surrounding infant feeding remains poorly understood. We investigated 1) the impact of in-hospital lactation support and maternal attitudes and behaviors regarding infant feeding on breastfeeding exclusivity, and 2) whether these potentially modifiable attitudes and behaviors differed between normal weights (NW) versus OW/Ob women. METHODS: NW (n=18) and OW/Ob (n=20) women and their infants were followed from birth to 4-months postpartum. In-hospital experiences, problems and help received regarding breastfeeding were documented. Six maternal attitudes and behaviors surrounding infant feeding were assessed at 2-weeks and 4-months. These factors were compared between NW and OW/OB women, and in relation to breastfeeding exclusivity. RESULTS: In-hospital experiences, assistance received regarding breastfeeding difficulties, and infant breastfeeding exposure did not differ between NW and OW/Ob women. At 4-months OW/Ob women were more likely to feed their infant on a schedule (p<0.03); this was the only difference in attitudes/behaviors between BMI-groups. Feeding the infant on a schedule was predictive of lower total breastfeeding exposure (p<0.05). Maternal concern about infant under-eating/becoming underweight was associated with several negative feeding behaviors, including reduced breastfeeding exposure (p<0.02), pressuring feeding style (p<0.01), and feeding to calm fussiness (p<0.01). CONCLUSION: This hospital setting provided equitable breastfeeding support to OW/Ob and NW women. Maternal concern over infant under-eating/under-gaining and encouragement to feed on-demand are prime interventional targets to improve breastfeeding outcomes; the latter may be especially relevant to OW/Ob mothers.

Tailoring the microstructure and surface morphology of metal thin films for nano-electro-mechanical systems applications.

Metallic structural components for micro-electro-mechanical/nano-electro-mechanical systems (MEMS/NEMS) are promising alternatives to silicon-based materials since they are electrically conductive, optically reflective and ductile. Polycrystalline mono-metallic films typically exhibit low strength and hardness, high surface roughness, and significant residual stress, making them unusable for NEMS. In this study we demonstrate how to overcome these limitations by co-sputtering Ni-Mo. Detailed investigation of the Ni-Mo system using transmission electron microscopy and high-resolution transmission electron microscopy (TEM/HRTEM), x-ray diffraction (XRD), nanoindentation, and atomic force microscopy (AFM) reveals the presence of an amorphous-nanocrystalline microstructure which exhibits enhanced hardness, metallic conductivity, and sub-nanometer root mean square (RMS) roughness. Uncurled NEMS cantilevers with MHz resonant frequencies and quality factors ranging from 200-900 are fabricated from amorphous Ni-Mo. Using a sub-regular solution model it is shown that the electrical conductivity of Ni-Mo is in excellent agreement with Bhatia's structural model of electrical resistivity in binary alloys. Using a Langevin-type stochastic rate equation the structural evolution of amorphous Ni-Mo is modeled; it is shown that the growth instability due to the competing processes of surface diffusion and self-shadowing is heavily damped out due to the high thermal energies of sputtering, resulting in extremely smooth films.

Electrokinetic control of fluid flow in native poly(dimethylsiloxane) capillary electrophoresis devices.

Capillary zone electrophoresis (CZE) devices fabricated in poly(dimethylsiloxane) (PDMS) require continuous voltage control of all intersecting channels in the fluidic network in order to avoid catastrophic leakage at the intersections. This contrasts with the behavior of similar flow channel designs fabricated in glass substrates. When the injection plugs are shaped by voltage control and leakage from side channels is controlled by the application of pushback voltages during separation, fluorescein samples give 64 200 theoretical plates (7000 V separation voltage, E = 1340 V/cm). Native PDMS devices exhibit stable retention times (+/- 8.6% RSD) over a period of five days when filled with water. Contact angles were unchanged (+/- 1.9% RSD) over a period of 16 weeks of dry storage, in contrast to the known behavior of plasma-oxidized PDMS surfaces. Electroosmotic flow (EOF) was observed in the direction of the cathode for the buffer systems studied (phosphate, pH 3-10.5), in the presence or absence of hydrophobic ions such as tetrabutylammonium or dodecyl sulfate. Electroosmotic mobilities of 1.49 x 10(-5) and 5.84 x 10(-4) cm2/Vs were observed on average at pH 3 and 10.5, respectively, the variation strongly suggesting that silica fillers in the polymer dominate the zeta potential of the material. Hydrophobic compounds such as dodecyl sulfate and BODIPY 493/503 adsorbed strongly to the PDMS, indicating the hydrophobicity of the channel walls is clearly problematic for CZE analysis of hydrophobic analytes. A method to stack multiple channel layers in PDMS is also described.