Deepa Jatti Patil

Temperature dependence of oxygen isotope fractionation of CO2 from magnesite-phosphoric acid reaction

Abstract New experimental results are reported on oxygen isotope fractionation factors, α T , between the δ 18 O compositions of carbon dioxide liberated by phosphoric acid in the temperature interval of 323 to 373K and that of total oxygen from a natural magnesite (MgCO 3 ). These results are distinctly different from some previously published mutually inconsistent data, and can be expressed as a linear relationship: 10 3 lnα T = [{(6.845 ± 0.475)∗10 5 }/T 2 ] + (4.22 ± 0.08), where 10 3 lnα T refers to fractionation at different temperatures T in Kelvin. Fractionation factors have also been determined at 323 and 368K on a natural calcite. The results on calcite are in excellent agreement with previously published data and can be written as:10 3 lnα T = [{(5.608 ± 0.151)∗10 5 }/T 2 ] + (3.89 ± 0.08). The combined results on magnesite and calcite yield a computed value of α = 1.01117 for dolomite at 298K, assuming equal proportion of 0.5 mole of magnesium and calcium in dolomite, the previously reported experimental values being 1.01109 and 1.01110.

Positive δ13C excursion in carbonate and organic fractions from the Paleoproterozoic Aravalli Supergroup, Northwestern India

Abstract Carbon and oxygen isotopic investigations have been carried out on the Archean and Paleoproterozoic carbonate rocks of the Udaipur region in the Aravalli Mountain Belt, northwestern India. The study has led to the interesting finding of 13 C enrichment in the carbonate rocks of the Jhamarkotra Formation (δ 13 C carb up to 11.1‰ V-PDB) belonging to the ∼2200–1900 Ma Paleoproterozoic Aravalli Supergroup. Further, it is observed that the organic carbon from phosphorite bearing stromatolitic dolomites of the same formation are also enriched in 13 C (δ 13 C org up to −11.1‰). However, it must be emphasized that the 13 C enriched carbonates and the organic fractions are from different stratigraphic levels although in the same formation, the former being at a lower stratigraphic level. A critical analysis of the field geological, petrological as well as the isotopic data indicates that the observed δ 13 C excursion in the carbonate carbon is not due to local causes such as methanogenesis or evaporitic conditions. The shallow water environment of deposition of these carbonates as well as the immediately overlying formations rules out the stratified ocean model for the observed excursion. The model involving high sedimentation rates and organic carbon burial has been preferred to explain the δ 13 C excursion in the carbonates of the Jhamarkotra Formation. The 13 C enrichment in organic fraction occurred in localized regions of the Aravalli sedimentary basin, where high productivity was supported by phosphorous supply indicating that the diffusion-limited pathways of organic carbon fixation were operative in the Paleoproterozoic itself. The 13 C enriched carbonate rocks of the Jhamarkotra Formation serve as the Indian example for the Paleoproterozoic global δ 13 C excursion.

Trace, rare-earth element, and oxygen isotopic systematics for the genesis of banded iron-formations: Evidence from Kushtagi schist belt, Archaean Dharwar Craton, India

Abstract The REE distribution pattern shapes (ΣFREE = 5.92 and 27.87 ppm in chert and hematite, respectively), positive Eu anomalies (Eu/Eu∗ = 3.25 and 2.1), and La N Yb N ratios (0.75 and 0.87) of the chert and hematite layers of the oxide facies BIFs of Kushtagi schist belt indicate that these constituents were derived from hydrothermal solutions generated and emplaced at an Archaean ocean ridge. However, their oxygen isotopic composition have been modified by mixing with the ambient ocean water and diagenetic reactions. δ18O values (13.9–17.4%c and −8.6 to 3.3‰ in chert and hematite, respectively) yield 150–250°C temperature in the diagenetic and lowest greenschist facies field. The mixing model of hydrothermal solutions with ocean water of 1:1000 ratio will not significantly change the oxygen isotope ratio of the ambient ocean water. Therefore, while the trace element data have retained hydrothermal signatures, oxygen isotopic signatures are imprinted by diagenetic processes.

Clinical implications of prescribing nonsteroidal anti-inflammatory drugs in oral health care—a review

Nonsteroidal anti-inflammatory drugs (NSAIDs), including both the traditional nonselective NSAIDs and the selective cyclooxygenase (COX)-2 inhibitors, are widely used for their anti-inflammatory and analgesic effects. They are routinely prescribed in dental practice for the management of pain and swelling. Their use in treating acute dental pain and chronic orofacial pain, as adjuncts to the treatment of periodontal disease, and to minimize edema following surgical procedures is well documented. However, long-term utilization of nonselective NSAIDs could increase the risk of gastrointestinal symptoms, ranging from mild (e.g., dyspepsia, nausea, or vomiting) to serious gastric problems (e.g., gastric bleeding or perforation). Therefore, selective COX-2 inhibitors have been developed with fewer GI side effects but the recently identified cardiovascular adverse reactions limit their routine use in dental practice. Another major concern for oral physicians is NSAID-induced mucosal lesions and prolongation of bleeding time during invasive dental procedures. This article reviews therapeutic and analgesic uses of NSAIDs in dentistry. The various issues surrounding NSAID-induced adverse reactions and their implications in dentistry are also discussed.

Botulinum toxin in the management of head and neck disorders

Botulinum toxin is a polypeptide protoxin synthesized by Clostridium botulinum that results in localized reduction of muscle activity by inhibiting acetylcholine release at the neuromuscular junction. In 2004, the US Food and Drug Administration approved its application in the treatment of various medical conditions, such as facial wrinkles, strabismus, cervical dystonia, blepharospasm, and hyperhidrosis. Later, its application extended to improving dental esthetics and gummy smile. It was found to be a safe and effective alternative to medical therapy to treat various head and neck disorders that have a neurologic component. In this review, we will highlight the mechanism of action and therapeutic benefits of botulinum toxin in the management of head and neck disorders.

Natural agents in the management of oral mucositis in cancer patients-systematic review

Introduction Oral mucositis is most severe complication of cancer therapy characterized by ulcerative lesions of oral mucosa causing negative impact on patients quality of life. Wide variety of therapeutic agents are available to reduce the lesions of mucositis. Currently, natural herbal remedies have become popular in treating this condition due to fewer side effects than synthetic drugs. Aim The aim of this systematic review is to compile evidence based studies to evaluate the effectiveness of natural agents in the management of oral mucositis induced by chemotherapy or radiotherapy in cancer patients. Materials and method Computerized literature searches were performed to identify all published articles in the subject. The following databases were used: PUBMED [MEDLINE], SCOPUS, COCHRANE DATABASE, EMBASE and SCIENCE DIRECT using specific keywords. The search was for limited articles published in English which were read in full by two authors. Results Twenty six randomized controlled trials satisfied our inclusion criteria. Most studies showed statistically significant result demonstrating the efficacy of natural agents with minimal side effects except manuka honey which was not tolerated by few patients. Conclusion Natural agents proved to be promising in healing cancer induced oral mucositis but future demands further randomized controlled clinical trials on these agents which should also be focused on drug interactions of the natural remedies.

Fusion imaging: a bipartite approach

Image fusion is the process of registering and combining multiple images from single or multiple imaging modalities to improve the imaging quality and applicability. It reduces randomness and redundancy to increase the diagnostic value of images for better assessment of medical problems. Fusion imaging was designed to overcome the disadvantages of morphological and/or functional imaging, and attempts to provide inputs that improve treatment planning, resulting in better prognostication. This review attempts to summarize the techniques and their applications in head and neck imaging.

Incidence of Helicobacter Pylori in oral aphthous stomatitis

Background/Aims: The aim of this study was to determine probable HP infection in oral aphthous samples by RUT in patients with recurrent aphthous stomatitis. Materials and Methods: This in vivo cross-sectional study was approved by the Ethics Committee of Swami Devi Dayal Dental College and Hospital according to the ethical standards. A total of 30 patients with minor recurrent aphthous stomatitis and 20 healthy control groups were included in the study. Results: Out of 30 patients with minor recurrent aphthous stomatitis, including 17 male and 13 female patients, with mean age of 47 and 38 years respectively, 21 patients (70%) were RUT (positive). Out of 20 healthy control groups, 12 males and 8 females, 2 (10%) were RUT (positive) [Table 1]. Conclusion: HP may play a role in the etiology of RAS; also it is likely that RUT may be rapid and reliable for investigation of HP in RAS lesions.

Dental considerations of capillary malformation

Hemangiomas and vascular malformations (VMs) are the two types of vascular lesions. VMs are further subdivided according to the type of involved vessels present as arterial, arterio-venous, venous, and capillary or lymphatic malformations. The capillary malformation (CM) previously was considered to be a hemangioma and was known as port wine stain, and hereby presenting a case report on the orodental manifestations of CM.