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Introduction: Human immunodeficiency virus (HIV) infection is a major health problem in India. The importance of oral lesions as clinical features of HIV infection and their gender specificity have been reported worldwide. However, there are very few reports on this aspect from the Indian subcontinent., Materials and Methods: The study population comprised 1000 consecutive HIV seropositive patients presenting to YRG CARE, a non-governmental organisation in Chennai, South India. The oral lesions were diagnosed based on clinical appearance using international criteria. Data were entered into a database and analysed using the SPSS package., Results: The male-to-female ratio was 3.4:1, and 95% of the patients had acquired infection via heterosexual contact. Majority of the patients (84%) were in the 21- to 40-year-old age groups. Pulmonary tuberculosis (12%) was the most common systemic finding. Oral lesions were seen in 86.6% of the patients. Gingivitis (72.3%) and periodontitis (33.2%) were the most common lesions followed by oral pigmentation (26.3%), oral candidiasis (23.8%), angular cheilitis (7.9%), oral ulcers (3.3%), oral hairy leukoplakia (2.1%), oral submucous fibrosis (0.9%) and leukoplakia (1.5%). The prevalence of oral candidiasis, periodontitis and oral hairy leukoplakia was higher in males than in females., Conclusions: Oral lesions occur commonly in HIV infection. A comprehensive oral examination plays an important role not only in the management of the patients, but also in assessing the immune status and in their follow-up.

Nano structured noble metals have very important applications in diverse fields as photovoltaics, catalysis, electronic and magnetic devices, etc. Here, we report the application of dual beam thermal lens technique for the determination of the effect of silver sol on the absolute fluorescence quantum yield (FQY) of the laser dye rhodamine 6G. A 532 nm radiation from a diode pumped solid state laser was used as the excitation source. It has been observed that the presence of silver sol decreases the fluorescence quantum efficiency. This is expected to have a very important consequence in enhancing Raman scattering which is an important spectrochemical tool that provides information on molecular structures. We have also observed that the presence of silver sol can enhance the thermal lens signal which makes the detection of the signal easier at any concentration., (Copyright 2003 Elsevier B.V.)

Talon cusp is a dental anomaly, which is present as an accessory cusp and is seen both in the deciduous and permanent dentition. It may occur unilaterally or bilaterally and has been reported mostly in maxillary teeth, with a few cases occurring in the mandible. Talon cusp is usually asymptomatic; however, there are many clinical problems associated with it. Talon cusp is clinically manifested in three forms: talon, semi-talon and trace talon. In this article, we present four case reports of talon cusp with an overview of different clinical variants of talon cusp, classification, etiopathogenesis, associated syndromes, clinical problems, and treatment modalities.

Optical absorption, fluorescence emission and surface enhanced Raman spectra of 1,5-dipiperidino anthraquinone (1,5-DPAQ) have been examined to elucidate the nature of molecule in different environments. Fluorescence emission and optical absorption measurements show that the polarity of the solvent plays a vital role through intermolecular hydrogen bonding and reorientational motion of solvent molecule around excited state fluorophore. Anisotropy measurement gives the angle between absorption and emission transition dipoles. The vibrational features observed in surface enhanced Raman spectroscopy (SERS) suggest that the molecules are chemisorbed. The adsorption of the molecule is through pi electrons in the anthraquinone ring and the axial lone pair of electrons of nitrogen. The orientation of the molecule is found to be 'flat-on'.

Surface enhanced Raman spectrum of 1,4-dimethylamino anthraquinone (1,4-DMAAQ) adsorbed on silver particles has been analyzed to understand the interaction between the molecule and silver surface. By studying the band intensities, the orientation of the molecule is determined. The high intensity and frequency downshifted peak due to carbonyl stretching vibration plays a major role, which shows that the molecules are chemisorbed through coordinating sites. The new peaks observed due to C-N and N-H stretching vibrations also provide the evidence for adsorption through co-ordinating sites. Optical absorption and laser induced fluorescence spectra of this molecule have also been studied in different solvents to understand the effect of environment. Polarization and anisotropy measurements provide the change in orientation induced by solvent molecules between absorption and emission transition dipoles.