Head and Neck Lymphomas: Tip of the Iceberg?

ABSTRACT Background: Lymphomas comprise around 5% of all head and neck neoplasms and is the second most common extra nodal non hodgkin's lymphoma (NHL). However there is sporadic data on this entity from the subcontinent and hence we undertook this study. Methodology: This retrospective observational study was conducted at a tertiary care oncology center in India on diagnosed cases of NHL between January 2007 and December 2013. All patients were diagnosed based on histopathology and immunohistochemistry. Staging work up was done in all patients. Patients were considered as primary Head and Neck lymphomas if there was head and neck as the predominant site with or without regional lymph node involvement. Results: A total of 39 patients were studied. The age at presentation ranged from 29 to 78 years. The most common site of presentation was oral cavity (26%; n=10), followed by parotid and thyroid (18% each; n=7), eye (12%, n=5), maxilla (8%; n=3), paranasal sinuses (8%; n-=3) cheek (8%, n=3), and nasal cavity (2%, n=1). 41% (n=16) cases were in stage I, 43% (n=17) in stage II, 3% (n=1) in stage III, and 13% (n=5) were in stage IV. Most common histology was DLBCL (71%; n=28), followed by plasmablastic (10%; n=4), marginal zone (8%, n=3), mantle cell (3%; n=1), follicular lymphomas (5%; n=2), and NK/T cell lymphoma (3%; n=1). Most of the patients were of low risk (67%; n=26), followed by intermediate (23%; n=9), and high risk (10%; n=4). Patients were treated with anthracycline based chemotherapy +/-radiotherapy. In this study, stage I and stage II patients had a better prognosis and overall survival, median OS 28 months and 11 months, respectively. In stage III and IV, it was 7 and 3 months, respectively. According to site, the best median overall survival was seen with parotid (27 m), paranasal sinus (26m), and oral cavity (23 m), followed by thyroid (18 m) nasal cavity (17 m), maxilla (11 m), eye (8 m), and cheek (7 m)

Graphene Electrodes as Barrier-Free Contacts for Carbon Nanotube Field-Effect Transistors

This work evaluates the performance of carbon nanotube field-effect transistors (CNTFETs) using few layergraphene as the contact electrodematerial. We present the experimental results of the barrier height at carbon nanotube-graphene junction using temperature dependent I-V measurements. The estimated barrier height in our devices for both holes and electrons is close to zero indicating theohmic contact of graphenefor both p-type and n-type CNTFETs thus demonstrating the suitability of graphene as electrode material for CMOS-type circuits based on CNTFETs. Furthermore, we observe that there is no correlation between the barrier height and thickness of graphene

Towards Barrier Free Contacts to n-type CNTFETs using Graphene Electrodes

This work illustrates the performance of n-type carbon nanotube field effect transistors (CNTFET) contacted with few layer graphene. The true barrier height at graphene-CNT junction is estimated using temperature dependent I-V measurements. Thermionic emission model for carrier transport in CNTs is used in the study. The calculated barrier height values for electron transport are extremely small and slightly negative signifying the Ohmic contact of graphene with the conduction band of CNTs