Mesoscale Confinement Effects and Emergent Quantum Interference in Titania Antidot Thin Films.

The effect of confinement on electron and ion transport in oxide films is of interest both fundamentally and technologically for the design of next-generation electronic devices. In metal oxides with mobile ions and vacancies, it is the interplay of the different modes of charge transport and the corresponding current-voltage signatures that is of interest. We developed a patterned structure in titania films, with feature sizes of 11-20 nm, that allow us to explore confined transport. We describe how confinement changes the competing charge transport mechanisms, the patterned antidot array leads to displacement fields and confines the charge density that results in modified and emergent electron transport with an increase in conductivity. This emergent behavior can be described by considering electron interference effects. Characterization of the charge transport with electron holography and impedance spectroscopy, and through comparison with modeling, show that nanoscale confinement is a way to control quantum interference.

Ferroelectric Domain Studies of Patterned (001) BiFeO3 by Angle-Resolved Piezoresponse Force Microscopy.

We have studied the ferroelectric domains in (001) BiFeO3 (BFO) films patterned into mesas with various aspect ratios, using angle-resolved piezoresponse force microscope (AR-PFM), which can image the in-plane polarization component with an angular resolution of 30°. We observed not only stable polarization variants, but also meta-stable polarization variants, which can reduce the charge accumulated at domain boundaries. We considered the number of neighboring domains that are in contact, in order to analyze the complexity of the ferroelectric domain structure. Comparison of the ferroelectric domains from the patterned and unpatterned regions showed that the elastic relaxation induced by removal of the film surrounding the mesas led to a reduction of the average number of neighboring domains, indicative of a decrease in domain complexity. We also found that the rectangular BFO patterns with high aspect ratio had a simpler domain configuration and enhanced piezoelectric characteristics than square-shaped mesas. Manipulation of the ferroelectric domains by controlling the aspect ratio of the patterned BFO thin film mesas can be useful for nanoelectronic applications.

Acanthosis nigricans associated with an adrenocortical tumor in a pediatric patient.

Malignant acanthosis nigricans (AN) is a rare paraneoplastic syndrome seen primarily in adults with an underlying diagnosis of gastrointestinal adenocarcinoma. Malignant AN is characterized by hyperpigmentation and velvety hyperplasia of the epidermis. This condition is generally not associated with tumors in pediatric populations or in the adrenal gland. We present a case of malignant AN in a pediatric patient with a nonmalignant, functional adrenocortical tumor.

The effect of ratio and interval training on Pavlovian-instrumental transfer in mice.

Conditional stimuli (CS) that are paired with reward can be used to motivate instrumental responses. This process is called Pavlovian-instrumental transfer (PIT). A recent study in rats suggested that habitual responses are particularly sensitive to the motivational effects of reward cues. The current experiments examined this idea using ratio and interval training in mice. Two groups of animals were trained to lever press for food pellets that were delivered on random ratio or random interval schedules. Devaluation tests revealed that interval training led to habitual responding while ratio training produced goal-directed actions. The presentation of CSs paired with reward led to positive transfer in both groups, however, the size of this effect was much larger in mice that were trained on interval schedules. This result suggests that habitual responses are more sensitive to the motivational influence of reward cues than goal-directed actions. The implications for neurobiological models of motivation and drug seeking behaviors are discussed.

Benign transient hyperphosphatasemia in infants and children: a prospective cohort.

A total of 20 children with benign transient hyperphosphatasemia were prospectively evaluated with no additional investigations recommended except repeat serologic evaluation in 2-3 months. The average age of our patients was 2.5 years (range 1 year 2 months-5 years 10 months). The serum levels of alkaline phosphatase averaged 2383 IU/L (range 1013-5700 IU/L). Levels returned to normal within several months. This condition should be recognized by the clinician in order not to put patients through lengthy, expensive and unnecessary investigations.

Benign transient hyperphosphatasemia in infants and children: a prospective cohort.

A total of 20 children with benign transient hyperphosphatasemia were prospectively evaluated with no additional investigations recommended except repeat serologic evaluation in 2-3 months. The average age of our patients was 2.5 years (range: 1 year 2 months-5 years 10 months). The serum levels of alkaline phosphatase averaged 2383 IU/L (range: 1013-5700 IU/L). Levels returned to normal within several months. This condition should be recognized by the clinician in order not to put patients through lengthy, expensive and unnecessary investigations.

Continuous subcutaneous glucose monitoring in children with type 1 diabetes mellitus: a single-blind, randomized, controlled trial.

BACKGROUND: Tight glycemic control delays the long-term complications of type 1 diabetes mellitus (T1DM) but increases the risk for hypoglycemia. The continuous glucose-monitoring system (CGMS) provides blood glucose (BG) readings every 5 min, and its accuracy and reliability has been established in adults. However, there are limited data on its efficacy and safety in children. The purpose of this study was to determine if CGMS use improves metabolic control in children with T1DM. METHODS: Twenty-seven children (12 male) with T1DM participated in this single-blind, randomized, controlled trial. Participants (age: 11.4 +/- 3.7 (mean +/- SD) yr, range: 7-17 yr) were randomized to an intervention group (n = 18) or a control group (n = 9). Both groups wore the CGMS for 72-h periods at 0, 2, and 4 months. Adjustments in therapy for the intervention group were based on both CGMS and self-monitoring of BG (SMBG) data, while only SMBG data were used for the control group. Hemoglobin A1c (HbA1c) was determined at 0, 2, 4, and 6 months. The change in HbA1c from 0 to 6 months (HbA1c(Delta1-4)) and mean daily area under the CGMS curve for glucose <70 mg/dL area under the curve (AUC(<70)) were compared between groups. RESULTS: At study entry, HbA1c levels were similar in the intervention and control groups (8.4 +/- 0.98 and 8.8 +/- 0.86%, respectively; p = 0.12) but were significantly lower in the intervention group compared with the control group at study completion (7.8 +/- 0.88 and 8.6 +/- 0.95%, respectively; p = 0.02). The decrease in HbA1c of 0.61 +/- 0.68% in the intervention group was statistically significant (p = 0.03), whereas the decrease in HbA1c of 0.28 +/- 0.78% in the control group was not. Nonetheless, the differences in HbA1c(Delta1-4) between groups did not reach statistical significance (p = 0.13). There was no statistically significant difference in AUC(<70) between study groups (p = 0.18). CONCLUSION: CGMS use may improve metabolic control in children with T1DM without increasing the risk for hypoglycemia.