RADIOSENSITIVITY ENHANCEMENT OF HUMAN GLIOBLASTOMA MULTIFORME BY A HERPES SIMPLEX VIRUS VECTOR

Ionizing radiation (IR) is the primary adjuvant treatment for glioblastoma multiforme (GBM), the most aggressive primary brain tumor in adults. Enhancement of the effects of IR may increase patient survival and quality of life in patients with GBM. The repair of DNA double strand breaks (DSBs) produced by IR proceeds along two pathways, nonhomologous end-joining (NHEJ) and homologous repair (HR). The herpes simplex virus (HSV) immediate-early protein, ICP0, has been shown to induce the degradation of the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs). DNA-PKcs is the primary component of NHEJ, the major DNA DSB repair pathway in mammalian cells. A replication-defective HSV-1 vector, d106, which solely expresses the immediate-early (IE) protein, ICP0, was used to determine the effect of ICP0 on GBM cell survival and DNA repair after IR treatment. Preinfection of two radioresistant GBM cells lines by d106 resulted in decreased cell survival and proliferation, protein degradation of DNA-PKcs, inhibition of DNA DSB repair, and enhanced apoptosis following IR. Optimal intracerebral delivery of the HSV-1 mutant, d106, was established by convection-enhanced delivery (CED) in a mouse model. Translation of the effects of ICP0 in combination with IR was performed with CED of d106 in a mouse glioma model. CED of d106 in combination with whole-brain irradiation significantly increased animal survival

Structure and Magnetism of Mn5Ge3 Nanoparticles

In this work, we investigated the magnetic and structural properties of isolated Mn5Ge3 nanoparticles prepared by the cluster-beam deposition technique. Particles with sizes between 7.2 and 12.6 nm were produced by varying the argon pressure and power in the cluster gun. X-ray diffraction (XRD)and selected area diffraction (SAD) measurements show that the nanoparticles crystallize in the hexagonal Mn5Si3-type crystal structure, which is also the structure of bulk Mn5Ge3. The temperature dependence of the magnetization shows that the as-made particles are ferromagnetic at room temperature and have slightly different Curie temperatures. Hysteresis-loop measurements show that the saturation magnetization of the nanoparticles increases significantly with particle size, varying from 31 kA/m to 172 kA/m when the particle size increases from 7.2 to 12.6 nm. The magnetocrystalline anisotropy constant K at 50 K, determined by fitting the high-field magnetization data to the law of approach to saturation, also increases with particle size, from 0.4 × 105 J/m3 to 2.9 × 105 J/m3 for the respective sizes. This trend is mirrored by the coercivity at 50 K, which increases from 0.04 T to 0.13 T. A possible explanation for the magnetization trend is a radial Ge concentration gradient

Fundamental and Magnetic-Hardening Studies of Rare-Earth and Nanocomposite Magnets

In this project we study new nanocrystalline and nanocomposite structures that have high potential for permanent-magnet development. These materials, which can be synthesized to have either very high or intermediate coercivities, have many applications in electric power, transportation, and information-storage industries. There is great interest in further development of understanding and application of these materials. Following are brief discussions of recent research highlights for the present grant

Anomalous magnetic hysteresis in an amorphous Nd\u3csub\u3e54\u3c/sub\u3eCo\u3csub\u3e36\u3c/sub\u3eB\u3csub\u3e10\u3c/sub\u3e alloy

The hysteresis and crystallization behavior of an amorphous Nd54Co36B10 alloy have been examined over a range of temperatures. Crystallization studies show a glass transition temperature around 210 °C, two crystallization peaks at around 220 and 360 °C, and two endothermic peaks at around 530 and 600 °C, respectively. ac susceptibility measurements show an ordering temperature of 38 K for the amorphous phase. Four additional magnetic phases have been observed in the crystallized samples with ordering temperatures 17, 45, 90, and 190 K, respectively. Magnetic measurements on melt-spun ribbons reveal a coercivity of 6 kOe at 4.2 K. The coercivity at 4.2 K of a sample heat treated at the first crystallization temperature is increased to 8 kOe but is reduced gradually upon annealing at higher temperatures and is only 2.5 kOe in a sample annealed at a temperature close to the second endothermic peak. Journal of Applied Physics is copyrighted by The American Institute of Physics

COVID-19 and the use of masks by children. Statement from the Association of Schools of Public Health in the European Region and the European Academy of Paediatrics

Despite the fact that the use of masks and respirators in adults has already reached a consensus in almost all countries and for situations in which they are recommended, this is not the case for the use of mask by children. This statement, regarding the usage of mask by children, has been jointly produced by the Association of Schools of Public Health in the European Region (ASPHER) and the European Academy of Paediatrics (EAP). It provides recommendations on the size of the mask, the material and ergonomics of children's masks. The authors also discuss the psychological dimension of children when they are asked to wear a mask. Moreover, they tackle the difficulties of children with disabilities.info:eu-repo/semantics/publishedVersio