A cluster randomized trial of a transition intervention for adolescents with congenital heart disease: rationale and design of the CHAPTER 2 study

BACKGROUND: The population of adolescents and young adults with congenital heart disease (CHD) is growing exponentially. These survivors are at risk of late cardiac complications and require lifelong cardiology care. However, there is a paucity of data on how to prepare adolescents to assume responsibility for their health and function within the adult health care system. Evidence-based transition strategies are required. METHODS: The Congenital Heart Adolescents Participating in Transition Evaluation Research (CHAPTER 2) Study is a two-site cluster randomized clinical trial designed to evaluate the efficacy of a nurse-led transition intervention for 16–17 year olds with moderate or complex CHD. The primary endpoint is excess time to adult CHD care, defined as the time interval between the final pediatric cardiology appointment and the first adult CHD appointment, minus the recommended time interval between these appointments. Secondary endpoints include the MyHeart score (CHD knowledge), Transition Readiness Assessment Questionnaire score, and need for catheter or surgical re-intervention. Participants are enrolled in clusters based on week of attendance in the pediatric cardiology clinic. The intervention consists of two one-hour individualized sessions between a cardiology nurse and study participant. Session One focuses on knowledge of the participant’s CHD, review of their cardiac anatomy and prior interventions, and potential late cardiac complications. Session Two focuses on self-management and communication skills through review and discussion of videos and role-play. The study will recruit 120 participants. DISCUSSION: Many adolescents and young adults experience a gap in care predisposing them to late cardiac complications. The CHAPTER 2 Study will investigate the impact of a nurse-led transition intervention among adolescents with CHD. Fidelity of the intervention is a major focus and priority. This study will build on our experience by (i) enrolling at two tertiary care programs, (ii) including a self-management intervention component, and (iii) evaluating the impact of the intervention on time to ACHD care, a clinically relevant outcome. The results of this study will inform pediatric cardiology programs, patients and policy makers in judging whether a structured intervention program provides clinically meaningful outcomes for adolescents and young adults living with CHD. TRIAL REGISTRATION: ClinicalTrials.gov ID NCT0172333

Characterization of different samples by Atomic Force Microscopy

Atomic Force Microscopy (AFM) finds wide scale appli-cation in the field of surface characterization of nanostructured materials including polymers, ceramics, biological and metallic materials. In metallic materials characterization by AFM, deformation dislocation slip steps of duplex steel in micrometer scale has been rep-orted. But study of twins or grain boundary sigma relat-ion by AFM will be interesting. Also, the use of AFM in characterization of different kinds of nanomaterials produced by biomimetic route is a fascinating task. This paper is a mini-review of AFM, its different modes of operation, advantages and attractive applications in nanostructured realm

Thermal behavior of ferromagnetic bio-compatible nanoparticles: A comparative DSC study

Three pairs of ferromagnetic nanoparticle - samples obtained with and without application of d.c. magnetic field during their synthesis in aqua solutions are investigated with differential scanning calorimeter (DSC). In all three cases during first heating, the results show significant difference in the behavior between the samples that are synthesized with application of a d.c. magnetic field versus samples obtained without magnetic field. At second heating run, the difference disappears. Obviously the specific self-organization phenomena induced by a d.c. magnetic field application during borohydride reduction synthesis is destroyed by the first heating to 450 ºC. It was found also that the thermal behavior of samples using monovalent Cl anion of Co salt as precursor is rather different as compared to samples obtained with polyvalent anions such as SO4 and (en)2. While the first gives separated peaks for dehydration and dehydroxlation the second types of samples shows very broad peaks with shoulders. Results show that DSC could be a valuable tool for investigation of the self-organization of ferromagnetic nanoparticle

Asymptotic sojourn time analysis of finite-source M/M/1 retrial queuing system with two-way communication

The aim of the present paper is to investigate a retrial queuing system M/M/1 with a finite number of sources and two-way communication. Each source can generate a request after an exponentially distributed time and will not generate another one until the previous call return to the source. If an incoming customer finds the server idle its service starts. Otherwise, if the server is busy an arriving (primary or repeated) customer moves into the orbit and after some exponentially distributed time it retries to enter the server. When the server is idle it generates an outgoing call after an exponentially distributed time with different parameters to the customers in the orbit and to the sources, respectively. The service times of the incoming and outgoing calls are exponentially distributed with different rates. Applying method of asymptotic analysis under the condition of unlimited growing number of sources it is proved that the limiting sojourn/waiting time of the customer in the system follows a generalized exponential distribution with given parameters. In addition, the asymptotic average number of customers in the orbit is obtained