Dhoom Singh Mehta

Future impact of nanotechnology on medicine and dentistry

The human characteristics of curiosity, wonder, and ingenuity are as old as mankind. People around the world have been harnessing their curiosity into inquiry and the process of scientific methodology. Recent years have witnessed an unprecedented growth in research in the area of nanoscience. There is increasing optimism that nanotechnology applied to medicine and dentistry will bring significant advances in the diagnosis, treatment, and prevention of disease. Growing interest in the future medical applications of nanotechnology is leading to the emergence of a new field called nanomedicine. Nanomedicine needs to overcome the challenges for its application, to improve the understanding of pathophysiologic basis of disease, bring more sophisticated diagnostic opportunities, and yield more effective therapies and preventive properties. When doctors gain access to medical robots, they will be able to quickly cure most known diseases that hobble and kill people today, to rapidly repair most physical injuries our bodies can suffer, and to vastly extend the human health span. Molecular technology is destined to become the core technology underlying all of 21st century medicine and dentistry. In this article, we have made an attempt to have an early glimpse on future impact of nanotechnology in medicine and dentistry.

Elemental composition and sources of air pollution in the city of Chandigarh, India, using EDXRF and PIXE techniques

Abstract The aerosol samples collected from industrial, commercial and relatively cleaner zones from the city of Chandigarh, India, have been characterized using EDXRF and PIXE techniques. Sample collection was done over different time periods during 1994–1996 using the Millipore sampling kit. Sixteen elements, namely, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, and Pb, were quantified in these samples. The loading distribution of aerosol on the filter media was assessed by scanning the sample along its diameter using proton beam. The elemental concentrations in all the samples analyzed by both the techniques have been corrected for this distribution. The elemental concentrations measured at different sites were used in absolute principle component analysis in order to identify the major sources affecting these sites and to apportion the measured air pollutants to these sources. Plausible sources identified from this analysis are soil dust, industrial activity, vehicular traffic and refuse burning. The soil dust accounts for the major fraction of the measured mass.

K and L X-ray production cross sections and intensity ratios of rare-earth elements for proton impact in the energy range 20–25 MeV

Abstract The K α 1 , K α 2 , K β 1 , K β 2 , and the Ll, L α , L β and L γ X-ray production (XRP) cross sections and the relative intensity ratios for seven rare-earth elements with 60⩽ Z ⩽70 have been measured for 20, 22 and 25 MeV proton impact. The experimental data on the L-shell XRP cross sections for high energy proton impact have been reported for the first time. The measured XRP cross sections for all the K-lines and the relative intensity ratios K α 1 /K α , K α 2 /K α , K β 1 /K α , K β 2 /K α and K β /K α are in good agreement with the theoretical ones calculated using ECPSSR ionisation cross sections for all the elements investigated at the three beam energies. The Ll, L α , L β , and L γ XRP cross sections measured at the three proton energies are found to be in general higher than the theoretical values calculated using the ECPSSR ionisation cross sections and the RDHS model-based L i sub-shell fluorescence and Coster–Kronig (CK) yields. The measured relative intensity ratios L β /L α , and L γ /L α exhibit good agreement with the theoretical ones for all the elements under investigation, whereas the Ll/L α ratios are found to deviate from the theoretical ones.

Angular dependence of L x-ray emission in Pb following photoionization at 22.6 and 59.5 keV

The angular dependence of emission of L x-rays following photoionization at 22.6 and 59.5 keV in 82Pb has been investigated by measuring the intensity ratios I(L1)/I(L), I(L)/I(L) and I(L)/I(L) at different angles varying from 50° to 140°. The measurements were taken using 109Cd and 241Am radioisotopes as photon sources and a Si(Li) detector. The measured intensity ratios for various L x-rays are found to be angle independent within experimental error. This is contrary to the large anisotropic emission of L1 and L x-rays following photoionization as reported by Kahlon et al (1990a J. Phys. B: At. Mol. Opt. Phys. 23 2733; 1990b Pramana-J. Phys. 35 105) and by Ertugrul (1996 Nucl. Instrum. Methods B 119 345).

Photon-induced L X-ray production differential cross sections in thorium at 22.6 keV

Abstract The Ll, Lα, Lβ 2,4 , Lβ 1,3 and Lγ 1,5 X-ray production differential cross sections in 90 Th have been measured at 22.6 keV incident photon energy in an angular range 50–130°. The measurements were performed using a 109 Cd annular-source and a Si(Li) detector. The measured differential cross sections for various L X-rays are found to be angle-independent within experimental error. This is contrary to the strong angular-dependence of photon-induced Ll and Lα X-ray production cross sections as reported by Kahlon et al. (K.S. Kahlon, H.S. Aulakh, N. Singh, R. Mittal, K.L. Allawadhi, B.S. Sood, Phys. Rev. A 43 (1991) 1455) and Ertugrul (M. Ertugrul, Nucl. Instr. and Meth. B 119 (1996) 345). Integral cross sections for production of Ll, Lα, Lη, Lβ 6 , Lβ 2,4 , Lβ 1,3 , Lβ 9,10 , Lγ 1,5 and total Lγ X-rays are also deduced and are found to be in good agreement with those calculated using reliable theoretical values of the L i ( i =1, 2, 3) subshell photoionisation cross sections, fluorescence yields, X-ray emission rates and Coster–Kronig transition probabilities.

Oral and periodontal manifestations associated with systemic sclerosis: A case series and review

Systemic sclerosis is a rare connective tissue disorder with a wide range of oral manifestations. This case series reports significant oral and periodontal changes and also makes an attempt to correlate oral and systemic findings in these patients which enable the clinician for a better diagnosis and evolve a comprehensive treatment plan. Six patients with a known diagnosis of systemic sclerosis were included. After obtaining the patients informed consent, relevant medical history, oral manifestations including periodontal findings and oral hygiene index simplified index were recorded. In these patients, oral changes included restricted mouth opening and, resorption of the mandible. The periodontal changes observed were gingival recession, absence or minimal gingival bleeding on probing, and widened periodontal ligament space, radiographically. Patients with systemic sclerosis often show wide range of oral manifestations, which is of major concern for the dentist.

Determination of antibacterial activity of green coffee bean extract on periodontogenic bacteria like Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans: An in vitrostudy

Background: The aim of this study was to evaluate the antibacterial activity of pure green coffee bean extract on periodonto pathogenic bacteria Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn) and Aggregatibacter actinomycetemcomitans (Aa). Materials and Methods: Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBC) were used to assess the antibacterial effect of pure green coffee bean extract against periodonto pathogenic bacteria by micro dilution method and culture method, respectively. Results: MIC values of Pg, Pi and Aa were 0.2 μg/ml whereas Fn showed sensitive at concentration of 3.125 μg/ml. MBC values mirrors the values same as that of MIC. Conclusion: Antimicrobial activity of pure green coffee bean extract against Pg, Pi, Fn and Aa suggests that it could be recommended as an adjunct to mechanical therapy in the management of periodontal disease.

Comparative evaluation of plasma ROM levels in chronic periodontitis patients before and after non-surgical and surgical periodontal therapy: A clinical trial

Objective: Chronic periodontitis (CP) is associated with increased levels of blood reactive oxygen species (ROS). So, treatment of CP may lead to decrease in blood ROS. However, not much literature is available comparing the effect of surgical and non-surgical periodontal treatment on blood ROS levels. Reactive oxygen metabolites (ROMs) are a useful measure of blood ROS. The aim of this study was to investigate the effect of periodontal treatment on plasma ROM levels in CP patients. Materials and Methods: Thirty CP patients and 15 controls were monitored. Plasma samples were collected at baseline and the clinical parameters were recorded. The CP patients were randomly divided into two groups: Scaling and root planing (Group II) and periodontal flap surgery (Group III). Both groups were re-evaluated 1 and 2 months after therapy. Clinical parameters were reviewed, plasma samples collected, and ROM levels were determined using a spectrophotometric technique. Results: At baseline, the ROM levels for Group II and Group III were 519.8 ± 62.4 and 513.4 ± 74.7 CARR U, respectively, which were higher than Group I value (282.9 ± 23.9, P < 0.001). Periodontal treatment in CP patients resulted in improvement of clinical parameters and a highly significant reduction in plasma ROM level (P < 0.001) after 2 months. Also, there was a more significant reduction in plasma ROM levels in Group III as compared to Group II (P < 0.05). Conclusions: In CP patients, surgical periodontal treatment was more effective in lowering the plasma ROM levels than when non-surgical periodontal treatment was performed alone and, therefore, may be more beneficial in reducing systemic oxidative stress.

Gingival enlargement as an early diagnostic indicator in therapy-related acute myeloid leukemia: A rare case report and review of literature.

Treatment for Hodgkins lymphoma (HL) has resulted in excellent survival rates but is associated with increased risks of secondary therapy-related acute myeloid leukemia (t-AML). Gingival enlargement associated with bleeding and ulceration is the most common rapidly appearing oral manifestations of leukemic involvement. An 8 months pregnant patient reported with generalized gingival enlargement, with localized cyanotic and necrotic papillary areas. Co-relating the hematological report with the oral lesions and her past medical history of HL, a diagnosis of t-AML secondary to treatment for HL was made by the oncologist. As oral lesions are one of the initial manifestations of acute leukemia, they may serve as a significant diagnostic indicator for the dental surgeons and their important role in diagnosing and treating such cases. Furthermore, this case report highlights the serious complication of t-AML subsequent to HL treatment and the important role that a general and oral health care professional may play in diagnosing and treating such cases.

High-Spin States in Odd–Odd 168Lu

Abstract: High-spin states in the odd-odd 168Lu nucleus, populated in the 154Sm(19F,5n) reaction at a beam energy of 96 MeV, were investigated using in-beam γ-ray spectroscopy techniques. The BC neutron crossing in the yrast band, based on πg7/2[404]7/2+⊗νi13/2[642]5/2+ configuration, occurs at ħω= 0.31 MeV. The two side bands, based on πh11/2[514]9/2−⊗νi13/2[642]5/2+ and πh9/2[541]1/2−⊗νi13/2[642]5/2+ configurations, show anomalous signature-splitting and signature-inversion in the first one, to occur at ħω= 0.24 MeV. A moderately delayed BC-crossing is anticipated in the second one.