Electrons in graphene can travel for several microns without scattering at low temperatures, and their motion becomes ballistic, following classical trajectories. When a magnetic field B is applied perpendicular to the plane, electrons follow cyclotron orbits.Magnetic focusing occurs when electrons injected from one narrow contact focus onto a second contact located an integer number of cyclotron diameters away. By tuning the magnetic field B and electron density n in the graphene layer, we observe magnetic focusing peaks. We use a cooled scanning gate microscope to image cyclotron trajectories in graphene at 4.2 K. The tip creates a local change in density that casts a shadow by deflecting electrons flowing nearby; an image of flow can be obtained by measuring the transmission between contacts as the tip is raster scanned across the sample. On the first magnetic focusing peak, we image a cyclotron orbit that extends from one contact to the other. In addition, we study the geometry of orbits deflected into the second point contact by the tip. KEYWORDS:Graphene, scanning gate microscope, image cyclotron orbits, magnetic focusing. 2The unusual properties of graphene offer new approaches to electronics based on the ballistic motion of electrons. 14,16,17 Electrons that enter the graphene sheet at different angles all travel in a circle -as a consequence of this geometry, the electron flux peaks at a distance d c where circles overlap. As B is increased from zero, the electron transmission from one contact reaches the first magnetic focusing peak when d c = L. As the field continues to increase additional magnetic focusing peaks can occur when L is an integer multiple of d c , if the electron orbit bounces off the edge of the sample specularly. 16,[18][19][20] In this paper, we present images of the cyclotron orbits in graphene associated with the first magnetic focusing peak, recorded using a cooled SPM at 4.2 K with a tip that acts as a movable gate. [13][14][15][16][17] The sample is a high-mobility hBN-graphene-hBN sandwich patterned into a hall bar geometry using reactive ion etching with a mixture of CHF 3 and O (Fig. 1b) The first magnetic focusing peak is clearly shown in in Fig. 2a which presents experimental measurements of R m vs. B and n 1/2 at 4.2K with no tip present. As the density and magnetic field are increased, the transresistance peaks (red) along a track with B 1 ∝ n 1/2 as predicted by theory.At magnetic fields B along either side of the magnetic focusing peak, the transmission between the two contacts is reduced (blue), because cyclotron orbit trajectories are focused away from the receiving contact. Evidence for the second magnetic focusing peak with one bounce off the edge between contacts is seen (black) at magnetic fields B ~ 2B 1 . The intensity of the second peak is reduced by diffuse boundary scattering, which reduces the probability of specular reflection to 5 0.3 to 0.4 in magnetic focusing measurements 20 in graphene, and to almost zero in 1.0 µm wide ballistic graphene w...

Background: Perinatal intimate partner violence (IPV) is common and has significant negative health outcomes for mothers and infants. This study evaluated the effectiveness of an IPV intervention in reducing violence among abused women in perinatal home visiting programs. Materials and Methods: This assessor-blinded multisite randomized control trial of 239 women experiencing perinatal IPV was conducted from 2006 to 2012 in U.S. urban and rural settings. The Domestic Violence Enhanced Home Visitation Program (DOVE) intervention group (n = 124) received a structured abuse assessment and six home visitor-delivered empowerment sessions integrated into home visits. All participants were screened for IPV and referred appropriately. IPV was measured by the Conflicts Tactics Scale2 at baseline through 24 months postpartum. Results: There was a significant decrease in IPV over time (F = 114.23; p < 0.001) from baseline to 1, 3, 6, 12, 18, and 24 months postpartum (all p < 0.001). Additional models examining change in IPV from baseline indicated a significant treatment effect (F = 6.45; p < 0.01). Women in the DOVE treatment group reported a larger mean decrease in IPV scores from baseline compared to women in the usual care group (mean decline 40.82 vs. 35.87). All models accounted for age and maternal depression as covariates. Conclusions: The DOVE intervention was effective in decreasing IPV and is brief, thereby facilitating its incorporation within well-woman and well-child care visits, as well as home visiting programs, while satisfying recommendations set forth in the Affordable Care Act for IPV screening and brief counseling.

ObjectiveTo evaluate whether saxagliptin is non-inferior to basal-bolus insulin therapy for glycemic control in patients with controlled type 2 diabetes mellitus (T2DM) admitted to hospital with non-critical illnesses.Research design and methodsThis was an open-label, randomized controlled clinical trial. Patients received either saxagliptin or basal-bolus insulin, both with correctional insulin doses. The main study outcome was the mean daily blood glucose (BG) after the first day of randomization.ResultsOf 66 patients completing the study, 33 (age 69±10 years, 40% men) were randomized to saxagliptin and 33 (age 67±10 years, 52% men) to basal-bolus insulin therapy. The mean daily BG was 149.8±22.0 mg/dL in the saxagliptin group and 146.9±30.5 mg/dL in the insulin group (p=0.59). With an observed group difference of 2.9 mg/dL and an a priori margin of 20 mg/dL, inferiority of saxagliptin was rejected in favor of non-inferiority (p=0.007). There was no significant difference in the percentage of high or low BG values. The insulin group received a higher number of insulin injections (2.3±1.7/day vs 1.2±1.9/day; p<0.001) as well as a higher daily insulin dose (13.3±12.9 units/day vs 2.4±3.3 units/day; p<0.001) than did the saxagliptin group. Continuous BG monitoring showed that glycemic variability was lower in the saxagliptin group as compared to the insulin group. Patient satisfaction scores were similar in the two groups.ConclusionsWe conclude that saxagliptin use is non-inferior to basal-bolus insulin in non-critically ill hospitalized patients with T2DM controlled on 0–2 oral agents without insulin. Saxagliptin use may decrease glycemic variability in these patients.Trial registration numberNCT02182895.

OBJECTIVES: Intimate partner violence (IPV) during pregnancy affects 0.9% to 17% of women and affects maternal health significantly. The impact of IPV extends to the health of children, including an increased risk of complications during pregnancy and the neonatal period, mental health problems, and cognitive delays. Despite substantial sequelae, there is limited research substantiating best practices for engaging and retaining high-risk families in perinatal home visiting (HV) programs, which have been shown to improve infant development and reduce maltreatment. METHODS:The Domestic Violence Enhanced Home Visitation Program (DOVE) is a multistate longitudinal study testing the effectiveness of a structured IPV intervention integrated into health department perinatal HV programs. The DOVE intervention, based on an empowerment model, combined 2 evidence-based interventions: a 10-minute brochurebased IPV intervention and nurse home visitation.RESULTS: Across all sites, 689 referrals were received from participating health departments. A total of 339 abused pregnant women were eligible for randomization; 42 women refused, and 239 women were randomly assigned (124 DOVE; 115 usual care), resulting in a 71% recruitment rate. Retention rates from baseline included 93% at delivery, 80% at 3 months, 76% at 6 months, and 72% at 12 months. CONCLUSIONS:Challenges for HV programs include identifying and retaining abused pregnant women in their programs. DOVE strategies for engaging and retaining abused pregnant women should be integrated into HV programs' federal government mandates for the appropriate identification and intervention of women and children exposed to IPV. Pediatrics 2013;132:S134-S139