Enter Your Search:
Results 1-2 (2)
Go to page number:
Select a Filter Below
Beilstein Journal of Nanotechnology (1)
Journal of Oral and Maxillofacial Pathology : JOMFP (1)
George, Antony (2)
Gölzhäuser, A (1)
Hlawacek, Gregor (1)
Lorbek, Stefan (1)
Mani, Varghese (1)
Mocking, Tijs F (1)
Poelsema, Bene (1)
Veligura, Vasilisa (1)
Zandvliet, Harold J W (1)
van Gastel, Raoul (1)
Year of Publication
Imaging ultra thin layers with helium ion microscopy: Utilizing the channeling contrast mechanism
Mocking, Tijs F
van Gastel, Raoul
Zandvliet, Harold J W
Beilstein Journal of Nanotechnology
Background: Helium ion microscopy is a new high-performance alternative to classical scanning electron microscopy. It provides superior resolution and high surface sensitivity by using secondary electrons.
Results: We report on a new contrast mechanism that extends the high surface sensitivity that is usually achieved in secondary electron images, to backscattered helium images. We demonstrate how thin organic and inorganic layers as well as self-assembled monolayers can be visualized on heavier element substrates by changes in the backscatter yield. Thin layers of light elements on heavy substrates should have a negligible direct influence on backscatter yields. However, using simple geometric calculations of the opaque crystal fraction, the contrast that is observed in the images can be interpreted in terms of changes in the channeling probability.
Conclusion: The suppression of ion channeling into crystalline matter by adsorbed thin films provides a new contrast mechanism for HIM. This dechanneling contrast is particularly well suited for the visualization of ultrathin layers of light elements on heavier substrates. Our results also highlight the importance of proper vacuum conditions for channeling-based experimental methods.
channeling; contrast mechanism; helium ion microscopy; ion scattering; thin layers
Gnathic osteosarcomas: Review of literature and report of two cases in maxilla
Journal of Oral and Maxillofacial Pathology : JOMFP
Primary neoplasms of the skeleton are rare, accounting for 0.2% of overall human tumor burden. Osteosarcoma (OS) accounts for 15–35% of all primary bone tumors, while gnathic osteosarcomas (GOS) represent 4–8% of all osteosarcomas. GOS shows a predilection for men, a peak incidence of 33 years, and affects the mandible more than the maxilla. We review the scientific literature for a better understanding of the clinical, radiographic, and histopathological features of GOS, along with its etiology, staging, treatment protocol, prognosis, and survival. Evidence from molecular research suggests that it is a differentiation disease that disrupts osteoblasts differentiation from mesenchymal stem cells. The classical radiographic finding of a “sunburst” appearance is appreciated only in 50% of GOS. The universally accepted staging system is not commonly used due to the rarity with which they metastasize to the regional lymph nodes. A number of distinct histopathological subtypes have been described, of which osteoblastic GOS are most common. The treatment protocol is multimodal consisting of preoperative chemotherapy followed by surgery and postoperative chemotherapy, and has a 60-70% five-year survival rate. We present two case reports of osteosarcoma involving the maxillary that were initially misdiagnosed as peripheral giant cell granuloma and osteoma of the maxilla, respectively. These case reports demonstrate the diverse clinical, radiographic, and histopathological features that can be encountered in GOS.
Bone tumor; gnathic; jaw; maxilla; metastasis; osteogenic sarcoma; osteosarcoma; prognosis; recurrence; staging; treatment
Results 1-2 (2)
Go to page number:
Remove citation from clipboard
Add citation to clipboard
This will clear all selections from your clipboard. Do you wish proceed?
Clipboard is full! Please remove an item and try again.
PubMed Central Canada is a service of the
Canadian Institutes of Health Research
(CIHR) working in partnership with the National Research Council's
Canada Institute for Scientific and Technical Information
in cooperation with the
National Center for Biotechnology Information
U.S. National Library of Medicine
(NCBI/NLM). It includes content provided to the
PubMed Central International archive
by participating publishers.