ABSTRACT
The nonlinear electrical characteristic of carbon nanodots (CNDs) has revealed important physical phenomena of charge trapping playing a dominant role in surface interactions. Functional groups on the surface of CNDs attract ambient water molecules which in turn act as charge traps and give rise to electrical hysteresis that plays a dominant role in understanding charge transport in CNDs on surface interactions. Hysteresis in the current-voltage response is further utilized to study the interaction of the CNDs with nitrogen dioxide gas as an external stimuli. The hysteresis area is observed to be dependent on the time of gas interaction with the CNDs, therefore revealing the interaction mechanism of the CNDs with the gas.
ABSTRACT
PURPOSE: Although much has been mentioned in the literature worldwide regarding the outcome of pectoralis major myocutaneous flaps (PMMFs), hardly any studies are available that mention the outcome of PMMFs in female patients. It has been presumed that complication rates after PMMF reconstruction in female patients are higher because of the presence of more adipose tissue in the flap. The objective of this study was to analyze our data regarding the outcomes of PMMFs in female patients with oral cancer undergoing reconstruction after tumor ablation. MATERIALS AND METHODS: In this retrospective study from January 2008 to May 2012, performed in a single institution in south India, we have analyzed our data on PMMFs in 140 female patients with oral cancer. The operative technique used was essentially the same as that described originally by Ariyan. However, to preserve the deltopectoral flap area, the incision was appropriately modified in a manner as described by Schuller. RESULTS: The mean age of the patients was 52.36 years, with a range from 30 to 76 years. They presented mostly with ulcers or ulceroproliferative lesions. Most of the patients had a history of tobacco and betel nut chewing. All of them underwent composite resection and reconstruction with PMMF under general anesthesia. Of the patients, 30 (21.4%) had complications, comprising infection (8), superficial flap necrosis (11), combined wound infection and superficial flap necrosis (3), total flap failure (2), and orocutaneous fistula (6). CONCLUSIONS: PMMF reconstruction is a reliable and cosmetically acceptable method of reconstruction in female patients for oral cavity defects after tumor ablation.
Subject(s)
Mouth Neoplasms/surgery , Myocutaneous Flap/transplantation , Pectoralis Muscles/transplantation , Plastic Surgery Procedures/methods , Adult , Aged , Areca , Carcinoma, Squamous Cell/secondary , Carcinoma, Squamous Cell/surgery , Cutaneous Fistula/etiology , Female , Follow-Up Studies , Graft Survival , Humans , Lymphatic Metastasis/pathology , Middle Aged , Neck Dissection , Necrosis , Neoplasm Staging , Oral Fistula/etiology , Oral Ulcer/surgery , Postoperative Complications , Retrospective Studies , Smoking , Surgical Wound Infection/etiology , Nicotiana , Treatment OutcomeABSTRACT
We demonstrate the electrical transport behavior of carbon nanotubes (CNTs) upon exposure to organic analytes (namely ethanol, benzene, acetone and toluene). The resulting nonlinear current-voltage characteristics revealed a power law dependence of the differential conductivity on the applied bias voltage. Moreover, suppression of differential conductivity at zero bias is found to be dependent on different selective analytes. The power law exponent values have been monitored before, during and after exposure to the chemicals, which revealed a reversible change in the number of electron conducting channels. Therefore, the reduction in the number of conductive paths can be attributed to the interaction of the chemical analyte on the CNT surfaces, which causes a decrease in the differential conductivity of the CNT sample. These results demonstrate chemical selectivity of CNTs due to varying electronic interaction with different chemical analytes.
