Pulsed laser treatment at Fe/C<SUB>6</SUB>H<SUB>6</SUB> interface: a Mossbauer effect study

The pulsed ruby laser induced reactive-quenching process at Fe/C6H6 Ibenzenel has been investigated using conversion electron Mossbauer spectroscopy [CEMS]. It is shown that iron carbide phases can be synthesized when an iron foil immersed in benzene is treated with ruby Laser pulses [&#955;=694 nm, pulse width ~30 ns, energy density =15 J/cm2]. The results indicate the formation of &#949;-carbide and Fe5C2 phases in the as-treated sample and its transformation to Fe3C upon thermal treatment. The result of the CEMS measurements are supported by small angle X-ray diffractometry

Gymnemic acids inhibit hyphal growth and virulence in Candida albicans

Candida albicans is an opportunistic and polymorphic fungal pathogen that causes mucosal, disseminated and invasive infections in humans. Transition from the yeast form to the hyphal form is one of the key virulence factors in C. albicans contributing to macrophage evasion, tissue invasion and biofilm formation. Nontoxic small molecules that inhibit C. albicans yeast-to-hypha conversion and hyphal growth could represent a valuable source for understanding pathogenic fungal morphogenesis, identifying drug targets and serving as templates for the development of novel antifungal agents. Here, we have identified the triterpenoid saponin family of gymnemic acids (GAs) as inhibitor of C. albicans morphogenesis. GAs were isolated and purified from Gymnema sylvestre leaves, the Ayurvedic traditional medicinal plant used to treat diabetes. Purified GAs had no effect on the growth and viability of C. albicans yeast cells but inhibited its yeast-to-hypha conversion under several hypha-inducing conditions, including the presence of serum. Moreover, GAs promoted the conversion of C. albicans hyphae into yeast cells under hypha inducing conditions. They also inhibited conidial germination and hyphal growth of Aspergillus sp. Finally, GAs inhibited the formation of invasive hyphae from C. albicans-infected Caenorhabditis elegans worms and rescued them from killing by C. albicans. Hence, GAs could be useful for various antifungal applications due to their traditional use in herbal medicine

Mossbauer spectroscopy of ion-bombarded material surfaces

Recent trends in the field of ion bombardment of material surfaces are reviewed with a brief discussion about the present understanding of the subject. The use of novel characterization concepts to explore the ion beam-induced phenomena is emphasized and in this context the importance of the technique of conversion electron Mossbauer spectroscopy (CEMS) is brought out. A number of specific examples of the use ofCEMS technique to studies on ion implantation, ion beam mixing and corrosion of ion-bombarded surfaces have been given

Multicentric study on prevalence and risk factors for hypertension and diabetes in tribal communities in Western and Northern Maharashtra

Background and Objectives: Although a number of studies have been conducted on the prevalence of hypertension (HTN) and diabetes on tribal populations in different parts of India, comparative tribe-specific information is very meager. The main objective of this study is to generate tribe-specific information on the noncommunicable disorders (NCDs) and associated risk factors in scheduled tribes (STs) in Coastal and Western Maharashtra. Methods: The study was conducted on 1864 (females 960) adults (≥18 years) of both sexes in four dominant tribes in the region, namely, Bhils (748), Katkaris (560), Kokana (352), and Thakars (204), using the protocols approved by the Institutional Review Board. The study areas were geographically separated by large distances (250–500 km apart). Prevalence of overweight, diabetes, HTN, and hypercholesterolemia was measured using standard field-based techniques described in our earlier publication. Results: All STs in this study are grossly underweight; the Katkaris are worst affected. The prevalence of obesity (body mass index ≥30 kg/m2), HTN (blood pressure ≥140 mmHg), diabetes (capillary blood glucose >126 mg/dl), and hypercholesterolemia (cholesterol ≥200 mg/dl) was 0.9%, 11.7%, 6.7%, and 0.6% respectively. There are no statistically significant inter-tribal differences in the prevalence of these parameters. Age and obesity appeared to be the most dominant risk factors for HTN. However, there is no clear-cut picture about the influence of risk factors on diabetes or hypercholesterolemia. Interpretation and Conclusion: The prevalence of NCDs is still very low in STs, probably due to near absence of the risk factors such as obesity, sedentary lifestyle, and hyperlipidemia. STs are highly endogamous, and the study areas are separated by large distances ruling out intermingling of tribes. Yet, there is no consistent inter-tribal prevalence pattern for NCDs. Although the sample size is small, the results support the view that environmental factors are likely to be more important than host genetics in the causation of NCDs

Ion-beam mixing at the Fe/SiO<SUB>2</SUB> interface: a conversion-electron Mossbauer spectroscopy and x-ray-diffraction study

The effect of ion-beam-induced atomic mixing and subsequent thermal transformations at the Fe:SiO2 (single crystal) interface have been investigated by means of conversion-electron Mossbauer spectroscopy and small-angle x-ray-diffraction measurements. The ion-beam-mixed sample in the as-mixed state shows the presence of the Fe7SiO10 phase along with magnetic Fe-Si-O complexes. The mixed state undergoes structural modifications upon annealing at 450 &#176;C for several hours leading to an increase in Fe3+-to-Fe2+ ratio. The as-deposited sandwich structure upon annealing at 450 &#176;C leads to the formation of metal island structures

Formation of diamond particulates by pulsed ruby laser irradiation of graphite immersed in benzene

Pulsed ruby laser irradiation of pyrolytic graphite surface under benzene is shown to lead to formation of diamond particulates. Use of the techniques of laser Raman spectroscopy, scanning electron microscopy and small angle x-ray diffraction has been made to establish the result. A model based on the notion of hydrodynamic sputtering is proposed to explain the process