Human oral cancer is the single largest group of malignancies in the Indian subcontinent and the sixth largest group of malignancies worldwide. Squamous cell carcinomas (SCC) are the most common epithelial malignancy of the oral cavity, constituting over 90% of oral cancers. About 90% of OSCCs arise from pre-existing, potentially malignant lesions. According to WHO, OSCC has a 5-year survival rate of 45–60%. Late diagnosis, recurrence, and regional or lymph nodal metastases could be the main causes of the high mortality rates. Biomarkers may help categorize and predict premalignant lesions as high risk of developing malignancy, local recurrence, and lymph nodal metastasis. However, at present, there is a dearth of such markers, and this is an area of ongoing research. Keratins (K) or cytokeratins are a group of intermediate filament proteins that show paired and differentiation dependent expression. Our laboratory and others have shown consistent alterations in the expression patterns of keratins in both oral precancerous lesions and tumors. The correlation of these changes with clinicopathological parameters has also been demonstrated. Furthermore, the functional significance of aberrant keratins 8/18 expression in the malignant transformation and progression of oral tumors has also been documented. This article reviews the literature that emphasizes the value of keratins as biomarkers for the prognostication of human oral precancers and cancers.
Oral carcinogenesis is a multistep process. As much as 5% to 85% of oral tumors can develop from potentially malignant disorders (PMD). Although the oral cavity is accessible for visual examination, the ability of current clinical or histological methods to predict the lesions that can progress to malignancy is limited. Thus, developing biological markers that will serve as an adjunct to histodiagnosis has become essential. Our previous studies comprehensively demonstrated that aberrant vimentin expression in oral premalignant lesions correlates to the degree of malignancy. Likewise, overwhelming research from various groups show a substantial contribution of vimentin in oral cancer progression. In this review, we have described studies on vimentin in oral cancers, to make a compelling case for vimentin as a prognostic biomarker.
Natural gas can contain significant amounts of impurifies, including CO2, H2S, N2, He, and C3+ hydrocarbons. These C3+ hydrocarbons are valuable chemical feedstocks and can be used as a liquid fuel for power generation. Membrane-based separation technologies have recently emerged as an economically favorable alternative due to reduced capital and operating cost. Polymeric membranes for the separation and removal of C3+ hydrocarbons from natural gas have been practiced in chemical and petrochemical industries. Therefore, these industries can benefit from membranes with improved C3+ hydrocarbon separation. This chapter overviews the different gas processing technologies for C3+ hydrocarbon separation and recovery from natural gas, highlighting the advantages, research and industrial needs, and challenges in developing highly efficient polymer-based membranes. More specifically, this chapter summarizes the removal of C3H8 and C4H10 from CH4 by prospective polymer architectures based on reverse-selective glassy polymers, rubbery polymers, and its hybrid mixed matrix membranes. In addition, the effect of testing conditions and gas compositions on the membrane permeation properties (permeability and selectivity) is reviewed.
The disordered structural pattern in ferrofluid occurs under external magnetic filed gives rise to significant optical properties such as birefringence, magnetochromatics and transmission. In this work transmission property has been utilized for making optical switch which can be electronically controlled with external TTL logic signal.