Mechanism of magnetization reduction in iron oxide nanoparticles.

Iron oxide nanoparticles are presently considered as main work horses for various applications including targeted drug delivery and magnetic hyperthermia. Several questions remain unsolved regarding the effect of size onto their overall magnetic behavior. One aspect is the reduction of magnetization compared to bulk samples. A detailed understanding of the underlying mechanisms of this reduction could improve the particle performance in applications. Here we use a number of complementary experimental techniques including neutron scattering and synchrotron X-ray diffraction to arrive at a consistent conclusion. We confirm the observation from previous studies of a reduced saturation magnetization and argue that this reduction is mainly associated with the presence of antiphase boundaries, which are observed directly using high-resolution transmission electron microscopy and indirectly via an anisotropic peak broadening in X-ray diffraction patterns. Additionally small-angle neutron scattering with polarized neutrons revealed a small non-magnetic surface layer, that is, however, not sufficient to explain the observed loss in magnetization alone.

[Ophthalmological symptoms of measles and their treatment]. / A kanyaró szemészeti tünetei és kezelése.

Measles, caused by the Morbilli virus, is a highly (about 95 %) contagious disease affecting primarily children, but without proper immunisation, adults can also be infected. The leading symptoms of the disease are high fever that presents after an incubation period of 9-10 days and the red rash that begins several days after the fever starts. Beyond specific generalized symptoms, measles may have ocular symptoms. The most commonly occurring conjunctivitis, the so-called "red eye symptom", is not characteristic only for measles infection, however, by taking the generalized symptoms it can suggest the diagnosis at the beginning of the disease. Conjunctivitis of varying severity is noticed in the half of the cases without using ophthalmological instrumentation. Using ophthalmological instrumentation, the mild forms of conjunctivitis can be diagnosed, by meticulous ophthalmological examination, further eye diseases can be discovered. The viral conjunctivitis can progress to keratitis and bacterial superinfection can occur. If the infection presents in childhood it can affect the posterior segment. The fight against measles is very effective in Hungary since the vaccination has been introduced, and the lack of vaccination is also the primary cause of the risk to the disease. In the diagnosis, symptomatic treatment of the disease and the curbing of possible mass infections, the practicing physician (general practitioner) has a key role. The correct care of the infected patient in Hungary is provided by a methodological letter, professional information and legal guides. Orv Hetil. 2017; 158(39): 1523-1527.

[Ocular symptoms and treatment of Ebola virus disease]. / Az Ebola-vírusos betegség szemészeti tünetei és kezelése.

Ocular signs and symptoms of Ebola infection initially suggest banal conjunctivitis, but in advanced cases severe haemorrhagic conjunctivitis appears and, in the final stage of the disease, retinal and chorioidal haemorrhages may occur which can cause even blindness. Although the viral infection accompanied by ocular symptoms of a non-specific conjunctivitis, the high fever present from the onset of the disease should raise the suspicion of Ebola infection. There is no causal therapy know so far, and the only adjunctive treatment may be delivered by an ophthalmologist. Because the virus can be detected in the tear, it can theoretically be the mediator of the infection and, therefore, ophthalmological examinations should be carried out with the highest caution. In case of suspected Ebola infection the nearest competent healthcare authority should be immediately alerted in order to take further actions.

Spotted-dick, a zinc-finger protein of Drosophila required for expression of Orc4 and S phase.

The highly condensed chromosomes and chromosome breaks in mitotic cells of a Drosophila mutant, spotted-dick/pita, are the consequence of defects in DNA replication. Reduction of levels of Spotted-dick protein, by either RNAi or mutation, leads to the accumulation of cells that have DNA content intermediate to 2N and 4N in proliferating tissues and also compromises endoreduplication in larval salivary glands. The Spotted-dick Zinc-finger protein is present in the nuclei of cells committed to proliferation but necessary in cells undertaking S phase. We show that Spotted-dick/Pita functions as a transcription factor and that, in cultured S2 cells, it is an activator of expression of some 30 genes that include the Orc4 gene, required for initiation of DNA replication. Chromatin immunoprecipitation indicates that it associates with the genes that it activates in S2 cells together with other sites that could represent genes activated in other tissues. We discuss the role of Spotted-dick in the coordination of cellular growth and DNA replication.

Metabolic effects of infection and postnatal steroids.

Optimal development of the newborn depends on rapid accretion of substrate in the neonatal period, particularly in the premature infant. Steroids and infection not only induce catabolism, but associated endogenous responses reprioritize crucial substrate to restore homeostasis. The result is a protein/energy deficit and concomitant delay in growth and development. Innovative feeding strategies and novel therapies are needed to reduce the impact of catabolism in this population.