Controlling the nanoscale rippling of graphene with SiO2 nanoparticles.

The electronic properties of graphene can be significantly influenced by mechanical strain. One practical approach to induce strain in graphene is to transfer atomically thin membranes onto pre-patterned substrates with specific corrugations. The possibility of using nanoparticles to impart extrinsic rippling to graphene has not been fully explored yet. Here we study the structure and elastic properties of graphene grown by chemical vapour deposition and transferred onto a continuous layer of SiO2 nanoparticles with diameters of around 25 nm, prepared on a Si substrate by the Langmuir-Blodgett technique. We show that the corrugation of the transferred graphene, and thus the membrane strain, can be modified by annealing at moderate temperatures. The membrane parts bridging the nanoparticles are suspended and can be reversibly lifted by the attractive forces between an atomic force microscope tip and graphene. This allows the dynamic control of the local morphology of graphene nanomembranes.

Histopathological and immunohistochemical features of gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal tumors of the gastrointestinal tract. Major advances in their definition and classification and the understanding of their molecular mechanisms have recently been made. These advances have become a model of targeted therapy in oncology. The diagnosis of GISTs relies on histological arguments - proliferation of spindle cells, seldom of epithelioid cells or both spindle and epithelioid cells - and on immunohistochemical arguments - expression of CD117 usually associated with CD34 expression. The evaluation of the prognosis is essential and based on a simple algorithm using two prognostic parameters, tumor size and mitotic index. The aim of this paper is a complex histopathological assessment, using both classic and modern (immunohistochemistry) techniques, of the GISTs comprised in the study. GISTs occur mainly in older adults (median age 60-69 years), anywhere along the gastrointestinal tract but also retroperitoneal. Most of them were nodular (75%), tumor necrosis and mucosal ulceration being the most frequent encountered secondary alterations; these modifications proved to be significantly correlated with large tumor size and high malignancy. Immunohistochemical evaluation revealed that 77 (97%) cases of GISTs presented a positive reaction for CD117, 50 (63%) cases were positive for CD34, 19 (24%) were positive for SMA and only 10 (13%) were positive for S100. Immunohistochemical evaluation remains an important tool of pathology in the diagnosis of GISTs, in the differential diagnosis from other gastrointestinal mesenchymal tumors and represents the gold standard for diagnosis of these tumors and an eligibility criterion for imatinib therapy.

[Dental rehabilitation in the mentally retarded performed under general anesthesia]. / Szellemi fogyatékosok általános érzéstelenítésben végzett fogászati rehabilitációja.

Experiences of dental treatments carried out in general anesthetization at the Oral Surgery and Dental Clinic between 1980 and 89. The 372 intravenous and 49 intratracheal narcoses and treatments are of "team" work characteristic and invite a better organization of the dental treatment of the mentally deficient.

[Side effects of dissolved and lyophilized cisplatin in the treatment of 133 head and neck tumors]. / Nebenwirkungen von gelöstem und lyophilisiertem Cisplatin bei der Behandlung von 133 Tumoren im Kopf-Hals-Bereich.

The authors have studied the side effects of a lyophilized and a dissolved cisplatin preparation in 133 patients with head and neck tumors. After intraarterial treatment (30 mg/24 hours) with dissolved cisplatin no nausea was observed, while treatment with lyophilized cisplatin was followed by nausea in rare cases (33%). Systemic treatment with dissolved cisplatin (50 mg/die) was associated with vomiting far less frequently (37%) than lyophilized cisplatin (90%). Metoclopramide was found to reduce these side effects.

Mechanism of local skin atrophy caused by intradermally injected corticosteroids.

Different hydrocortisone microcrystal suspensions applied intradermally in rabbits caused skin atrophy. This could be ascribed to secondary tissue degeneration as was ascertained histologically. The degree of degeneration was related to the concentration of the suspension, size of the microcrystals and frequency of the intervals between the injections. The ground substance of the connective tissue changes and is characterized by a basophilic granular mass, homogenized collagen fibers and degeneration of the elastic fibers. The pathomechanism of local skin atrophy not only differs from connective tissue degeneration caused by systemic corticosteroid treatment but also from the degeneration caused by topical treatment.