On the optical properties of Ag^{+15} ion-beam irradiated TiO_{2} and SnO_{2} thin films

The effects of 200-MeV Ag^{+15} ion irradiation on the optical properties of TiO_{2} and SnO_{2} thin films prepared by using the RF magnetron sputtering technique were investigated. These films were characterized by using UV-vis spectroscopy, and with increasing irradiation fluence, the transmittance for the TiO_{2} films was observed to increase systematically while that for SnO_{2} was observed to decrease. Absorption spectra of the irradiated samples showed minor changes in the indirect bandgap from 3.44 to 3.59 eV with increasing irradiation fluence for TiO_{2} while significant changes in the direct bandgap from 3.92 to 3.6 eV were observed for SnO_{2}. The observed modifications in the optical properties of both the TiO_{2} and the SnO_{2} systems with irradiation can be attributed to controlled structural disorder/defects in the system.Comment: 6 pages, ICAMD-201

Malignant peripheral nerve sheath tumors associated with neurofibromatosis type 1 - Report of 4 cases

We report 4 cases of malignant peripheral nerve sheath tumors (MPNST) with neurofibromatosis type 1 (NF1). Mean age was 29.5. Two of them had a family history. Three of them were male. All of them had enlarging mass and pain in the background of neurofibromas. Locations were popliteal, thigh and forearm. The masses were greater than 5 cm in diameter in each case. In two cases the mass was showing continuity with a nerve. One patient had a nonossifying fibroma as well as a MPNST. Wide excision and radiotherapy were applied to three of the patients. One of them did not take any therapy after surgical resection. Two of the patients died of lung metastases after a mean period of 12.5 months. In a majority of NF1 patients MPNST emerges from a preexisting neurofibroma. The patients with NF1 are at greatest risk for developing sarcomas, so they should be followed closely

Prognostic value of proliferating cell nuclear antigen immunostaining in pediatric rhabdomyosarcomas

Background: The levels of proliferating cell nuclear antigen (PCNA) are almost negligible in long-term quiescent cells and increase dramatically during the cell cycle. Recently, the monoclonal antibodies to PCNA have been used to demonstrate the proliferative component of paraffin-embedded tumor tissues. It has been shown to be available as a simple histological marker of proliferative activity and the PCNA labeling index has been correlated with the prognosis of several malignant neoplasms

Gastric metastasis of malignant fibrous histiocytoma presenting as gastrointestinal bleeding

Malignant fibrous histiocytoma (MFH) is a soft-issue sarcoma originating from fibroblast cells, characterized by a high rate of metastasis or recurrence. With only 4 cases described in the available English literature up to now, gastric metastasis of MFH is extremely rare. Among them only one case has been reported to lead to gastrointestinal bleeding. We report the case of a 55-year-old woman who underwent total gastrectomy. 14 months after resection of an MFH from the right side of retroperitoneum. The neoplasm was detected at the time of diagnostic workup for upper gastrointestinal bleeding. The resected specimen contained multiple polypoid nodular lesions which were located in the greater curvature. The clinical and pathological characteristics of gastric metastasis of MFH are presented herein with review of literature