Tuning the Fabrication of Nanostructures by Low-Energy Highly Charged Ions.

Slow highly charged ions have been utilized recently for the creation of monotype surface nanostructures (craters, calderas, or hillocks) in different materials. In the present study, we report on the ability of slow highly charged xenon ions (^{129}Xe^{Q+}) to form three different types of nanostructures on the LiF(100) surface. By increasing the charge state from Q=15 to Q=36, the shape of the impact induced nanostructures changes from craters to hillocks crossing an intermediate stage of caldera structures. A dimensional analysis of the nanostructures reveals an increase of the height up to 1.5 nm as a function of the potential energy of the incident ions. Based on the evolution of both the geometry and size of the created nanostructures, defect-mediated desorption and the development of a thermal spike are utilized as creation mechanisms of the nanostructures at low and high charge states, respectively.

Study of peripheral stem cells mobilization as a treatment line of pediatric dilated cardiomyopathy.

BACKGROUND: Mobilizing hematopoietic stem cells may be a promising intervention for the treatment of idiopathic dilated cardiomyopathy (IDCM) in infant and children. So the aim of the work is to evaluate the efficacy of granulocyte-colony stimulating factor (G-CSF) as a therapeutic modality in pediatric IDCM. METHODS: A randomized clinical trial was conducted on 40 pediatric patients with IDCM. They were subjected to history taking, clinical examination, serum lactate dehydrogenase (LDH), total creatinine phosphokinase (CPK), creatinine phosphokinase isoenzyme B (CK-MB) isoenzyme, and peripheral blood CD34(+) cell assessment before and at day 7 after subcutaneous G-CSF injection for 5 consecutive days. Echocardiography was done before and 1, 3 and 6 months after therapy. RESULTS: Clinical improvement in the form of regression of patients Modified Ross heart failure (MRHC) classification classes. Increased percentage of CD34(+) mobilized cells from the bone marrow, and significant increase in blood counts especially white blood cells 7 days after G-CSF injection. Significant improvement was found in echocardiographic data evaluating systolic function of the heart [Ejection fraction, Fractional shortening and systolic velocity at mitral annulus (Sm)]. CONCLUSIONS: Administration of G-CSF may be beneficial in improving systolic functions of the heart in pediatric IDCM and more studies with a large number of patients are needed.

Single ion induced surface nanostructures: a comparison between slow highly charged and swift heavy ions.

This topical review focuses on recent advances in the understanding of the formation of surface nanostructures, an intriguing phenomenon in ion-surface interaction due to the impact of individual ions. In many solid targets, swift heavy ions produce narrow cylindrical tracks accompanied by the formation of a surface nanostructure. More recently, a similar nanometric surface effect has been revealed for the impact of individual, very slow but highly charged ions. While swift ions transfer their large kinetic energy to the target via ionization and electronic excitation processes (electronic stopping), slow highly charged ions produce surface structures due to potential energy deposited at the top surface layers. Despite the differences in primary excitation, the similarity between the nanostructures is striking and strongly points to a common mechanism related to the energy transfer from the electronic to the lattice system of the target. A comparison of surface structures induced by swift heavy ions and slow highly charged ions provides a valuable insight to better understand the formation mechanisms.