Ferromagnetism in graphene nanoribbons: split versus oxidative unzipped ribbons

Two types of graphene nanoribbons: (a) potassium-split graphene nanoribbons (GNRs), and (b) oxidative unzipped and chemically converted graphene nanoribbons (CCGNRs) were investigated for their magnetic properties using the combination of static magnetization and electron spin resonance measurements. The two types of ribbons possess remarkably different magnetic properties. While the low temperature ferromagnet-like feature is observed in both types of ribbons, such room temperature feature persists only in potassium-split ribbons. The GNRs show negative exchange bias, but the CCGNRs exhibit a 'positive exchange bias'. Electron spin resonance measurements infer that the carbon related defects may responsible for the observed magnetic behaviour in both types of ribbons. Furthermore, proton hyperfine coupling strength has been obtained from hyperfine sublevel correlation experiments performed on the GNRs. Electron spin resonance provides no indications for the presence of potassium (cluster) related signals, emphasizing the intrinsic magnetic nature of the ribbons. Our combined experimental results may infer the coexistence of ferromagnetic clusters with anti-ferromagnetic regions leading to disordered magnetic phase. We discuss the origin of the observed contrast in the magnetic behaviours of these two types of ribbons

J Am Pharm Assoc (2003)

ObjectiveTo test the feasibility of offering rapid, point-of-care human immunodeficiency virus (HIV) testing at community pharmacies and retail clinics.DesignPilot program to determine how to implement confidential HIV testing services in community pharmacies and retail clinics.Setting21 community pharmacies and retail clinics serving urban and rural patients in the United States, from August 2011 to July 2013.Participants106 community pharmacy and retail clinic staff members.InterventionA model was developed to implement confidential HIV counseling and testing services using community pharmacy and retail clinic staff as certified testing providers, or through collaborations with organizations that provide HIV testing. Training materials were developed and sites selected that serve patients from urban and rural areas to pilot test the model. Each site established a relationship with its local health department for HIV testing policies, developed referral lists for confirmatory HIV testing/care, secured a CLIA Certificate of Waiver, and advertised the service. Staff were trained to perform a rapid point-of-care HIV test on oral fluid, and provide patients with confidential test results and information on HIV. Patients with a preliminary positive result were referred to a physician or health department for confirmatory testing and, if needed, HIV clinical care.Main outcome measuresNumber of HIV tests completed and amount of time required to conduct testing.ResultsThe 21 participating sites administered 1,540 HIV tests, with 1,087 conducted onsite by staff during regular working hours and 453 conducted at 37 different HIV testing events (e.g., local health fairs). The median amount of time required for pretest counseling/consent, waiting for test results, and posttest counseling was 4, 23, and 3 minutes, respectively. A majority of the sites (17) said they planned to continue HIV testing after the project period ended and would seek assistance or support from the local health department, a community-based organization, or an AIDS service organization.ConclusionThis pilot project established HIV testing in several community pharmacies and retail clinics to be a feasible model for offering rapid, point-of-care HIV testing. It also demonstrated the willingness and ability of staff at community pharmacies and retail clinics to provide confidential HIV testing to patients. Expanding this model to additional sites and evaluating its feasibility and effectiveness may serve unmet needs in urban and rural settings.200-2009-30908-00004/PHS HHS/United StatesCC999999/Intramural CDC HHS/United States2016-01-04T00:00:00Z25216878PMC469887