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1.
Phys Chem Chem Phys ; 23(27): 14898-14912, 2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34223588

RESUMO

The fusion of valuable material properties has led to the acceptance of sodium borosilicate (NBS) glasses for nuclear waste immobilization. Although popular, the mechanisms associated with these properties are still only partially discovered and need further exploration. Bearing this in mind, the combination of experiments, molecular dynamics (MD) simulations and the Dell, Yuan and Bray model have been used to understand the role of composition variation for structural and physical aspects of vitrified borosilicate glasses. Experiments have been conducted to evaluate the macroscopic glass parameters of density (ρ), glass transition temperature (Tg) and thermal expansion coefficient (TEC). Experimentally observed trends for ρ, Tg and TEC with composition have been found in good agreement with the MD results. MD studies also provide a microscopic understanding of the glass structure and phenomena associated with the change in the glass composition. A detailed view of local structure and medium-range connectivity for the borosilicate glasses has been explored. Owing to a large B4 population, the results showed the abundant presence of BO4-BO4 connections, we hereby omit the generally accepted "B[4] avoidance rule" for glass. The relative propensity for connecting SiO4/BO3/BO4 structural motifs is in line with the predictions made by the Dell, Yuan and Bray model. Furthermore, the effects of composition on the mechanical integrity of NBS glasses, including the elastic nature, plastic distortion, yielding, breaking stress, and brittle fracture, have been explored by MD simulations. In addition, the glass dynamics have been evaluated by diffusion coefficient and the results suggest that Na+ is likely to be more mobile in the case of NBS1 as compared to NBS2 and NBS3 due to significant disruption in the glass network introduced by a larger amount of Na2O network modifier. Also, the diffusivity was reduced with increasing B2O3 due to the altered role of Na+ ions from network modifiers to charge compensators. The combined study of experiments, MD simulations and the Dell, Yuan and Bray model establish the correlation between the microscopic structure and macroscopic properties of NBS glasses with varied composition, which might be of great scientific use for future glasses in various applications including nuclear waste immobilization.

3.
Phys Chem Chem Phys ; 22(26): 14682-14693, 2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32573611

RESUMO

Isotope effect is a quantum mechanical phenomenon and thus poses a challenge for the separation of isotopes of an element of interest, especially for heavy elements. Isotopic fractionation of zinc is also quite difficult and challenging but is necessitated due to various applications of its isotopes ranging from nuclear medicine to nuclear power reactors. Here, we developed the dibenzo-18-crown-6 (DB18C6) ether-functionalized poly(methacrylic acid) (PMA) resin by exploiting the ion and isotope recognition ability of the crown ether using DFT/MD simulations followed by experiments for isotopic fractionation of zinc. The PMADB18C6 adsorbent was prepared and suitably characterized. Both computational and experimental findings demonstrate that the adsorption and isotope separation of zinc with PMADB18C6 are due to the molecular recognition effect of the "O" dipole of the crown ether. Furthermore, both MD simulations and experiments suggest Langmuir type adsorption isotherms. The adsorption of Zn2+ ions on the PMA resin is predicted to be endothermic, whereas it is exothermic on the PMADB18C6 resin, as revealed from the experimentally observed enthalpy change. A small scale fixed bed column study was demonstrated to test the scale-up application. The values of the experimental separation factors: 1.0013 for 66/64 and 1.0027 for 68/64 confirm the computationally predicted results of 1.00088 and 1.0010, respectively, thus establishing the combined strength of the theory and experiments for the identification of efficient fractionating agents for a complex quantum isotope effect which eventually helps in planning further experiments in view of medicinal and technological applications of zinc isotopes.

4.
Nutrients ; 12(2)2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32024020

RESUMO

Dietary record tools such as food frequency questionnaire (FFQ) and food diaries (FD) are the most commonly used choices for assessing dietary intakes in most large-scale epidemiological studies. The authors developed a self-administered 360-item food frequency questionnaire (FFQ) to assess dietary intakes amongst a population-based cohort in South Kerala. In the validation study (n = 460), the data were collected using FFQs that were administered on three different occasions which were then compared to 7-day food records. The intake of foods and nutrients was higher as determined by the FFQ than that assessed using food records. Spearman correlations for macro-nutrients ranged from 0.72 for protein to 0.61 for carbohydrates and for micronutrients, from 0.71 for vitamin B6 to 0.34 for magnesium. The correlation was improved with energy-adjusted nutrient intakes. On average, the exact agreement for the macronutrients ranged from 48.2% to 57.1%, and that for micronutrients ranged from 66.7% to 41.9%, with the median percentage of 49.58%. The authors conclude that the FFQ has an acceptable reproducibility, however, there was a systematic trend towards higher estimates with the FFQ for most nutrients compared to the FD records.


Assuntos
Inquéritos sobre Dietas/normas , Dieta/estatística & dados numéricos , Avaliação Nutricional , Inquéritos e Questionários/normas , Adulto , Estudos Transversais , Feminino , Humanos , Índia , Masculino , Micronutrientes/análise , Nutrientes/análise , Reprodutibilidade dos Testes
5.
Indian J Gastroenterol ; 38(3): 220-246, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31352652

RESUMO

INTRODUCTION: These Asian Working Group guidelines on diet in inflammatory bowel disease (IBD) present a multidisciplinary focus on clinical nutrition in IBD in Asian countries. METHODOLOGY: The guidelines are based on evidence from existing published literature; however, if objective data were lacking or inconclusive, expert opinion was considered. The conclusions and 38 recommendations have been subject to full peer review and a Delphi process in which uniformly positive responses (agree or strongly agree) were required. RESULTS: Diet has an important role in IBD pathogenesis, and an increase in the incidence of IBD in Asian countries has paralleled changes in the dietary patterns. The present consensus endeavors to address the following topics in relation to IBD: (i) role of diet in the pathogenesis; (ii) diet as a therapy; (iii) malnutrition and nutritional assessment of the patients; (iv) dietary recommendations; (v) nutritional rehabilitation; and (vi) nutrition in special situations like surgery, pregnancy, and lactation. CONCLUSIONS: Available objective data to guide nutritional support and primary nutritional therapy in IBD are presented as 38 recommendations.


Assuntos
Dieta , Doenças Inflamatórias Intestinais/dietoterapia , Doenças Inflamatórias Intestinais/etiologia , Avaliação Nutricional , Ásia , Consenso , Gorduras na Dieta , Proteínas na Dieta/administração & dosagem , Ingestão de Energia , Humanos , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/cirurgia , Desnutrição/diagnóstico , Desnutrição/etiologia , Período Pós-Operatório
6.
J Phys Chem B ; 123(29): 6290-6302, 2019 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-31247137

RESUMO

Selection of suitable glass composition for vitrification of high-level radioactive wastes (HLWs) is one of the major challenges in nuclear waste reprocessing. Atomic and molecular level understanding of various structural, thermodynamical, and dynamical properties of a glass matrix can help in preliminary screening and thus reduce the dependency to some extent on tedious experimental procedures. In that context, extensive molecular dynamics (MD) simulations have been performed to calculate various microscopic properties of the glass matrix. The present article demonstrates that the "Buckingham potential-included long-ranged Coulomb interaction" can be utilized to simulate the glasses of varied compositions. The proposed simulation model has been validated for a wide range of glass compositions: pure glass matrix-SiO2 and B2O3; binary glass mixtures-SiO2-B2O3, Na2O-SiO2, and Na2O-B2O3; ternary glass-Na2O-SiO2-B2O3; and also the Cs2O- and SrO-doped matrix of sodium borosilicate. Most importantly, the MD results have been validated with those of in-house synthesized glasses. The effect of alkali addition on the density and network connectivity of the glass matrix has been explored. The results capture well the boron anomalies for varied concentrations of network formers and network modifiers. The intermediate structural ordering in glasses has been explored by calculating the partial and total structure factors. Further, the characteristic vibration density of states of constituent atoms in the glass matrix is determined. In addition, the glass structures with the addition of dopant oxides Cs2O and SrO have been examined as they are known to be prime heat-generating agents in HLWs. The results establish the structure and dynamics of the doped glass matrix to be a complex nature of the dopant's mass, concentration, charge, and ionic radius. The present MD results might be of great academic and technological significance for further studies in the field of vitrification and prediction of effects associated with the dopant's nature and concentration.

7.
Phys Chem Chem Phys ; 21(16): 8529-8542, 2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30957831

RESUMO

Nanotube appended membranes are shown to be very promising due to their ultrafast water transport and very high salt rejection ability. Using classical molecular dynamics, the present study reports the nanoscopic assessment of various molecular events for nanotube-based desalination, which might be useful for nanoscale devices during process operation at the macroscopic scale. The characteristics of water and ion flow are discussed with varied strength of pressure gradient and salt concentration for different scales of confinement. The results revealed that the membranes comprising nanotubes of 1.0-1.1 nm diameter can be optimized for efficient water desalination with more than >95% salt rejection. Furthermore, the anomalies in water flux through nanotubes are linked with the hydration characteristics of ions inside CNTs. The results show the maximum hydration of confined ions inside the nanotubes, which indicated the minimum permeability of water due to freezing effects. Furthermore, the MD results revealed that akin to bulk phases, the mass transport through nanotubes can be linked with the component diffusivity in the medium. It has been demonstrated that not only the diffusivities of water and ions, but even the gradient of water to ion diffusivity might be utilized to predict and explore the experimental observations, which might be helpful in optimizing the operational regime in nanotube-based filtrations. Moreover, the thermodynamic characteristics of the flow are discussed in terms of the entropy of water and ions using the robust two-phase thermodynamic (2PT) method. The results reflect that the entropy of water is linked to the distortion of the hydrogen bond network inside the nanotube confinement, at the nanotube-water interface and at the bulk solution, whereas the entropy of ions seems to be majorly dominated by their oscillation. Also, the interconnection of hydration structure, mass flux and the diffusivity of water and ions along with their thermodynamic origin are discussed.

9.
J Phys Chem B ; 122(14): 4115-4130, 2018 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-29569915

RESUMO

The Cu complex, which is the key chemical species in well-known Cu-Cl hybrid thermochemical cycles and also in numerous metal hydrometallurgical and sedimentary deposit processes, displays a wide variety of structural and dynamical characteristics that are further complicated by the presence of multiple oxidation states of Cu ions with different coordination chemistries, therefore they are difficult to explore from experiments alone. In this article, an attempt has been made to understand the coordination behavior of the Cu complex using MD simulations. The study provides compelling evidence of the experimentally observed multiple stoichiometries of Cu ions, i.e., 1:6:0, 1:5:1, and 1:4:2 for Cu+:H2O:Cl- and 1:6:0 for Cu2+:H2O:Cl-. The presence of the anionic Cu complex, [Cu+Cl2]-·2H2O, [Cu+Cl2]-·3H2O, [Cu2+Cl3]-·H2O, and [Cu2+Cl3]-·2H2O, was captured in the presence of excess chloride ions. Furthermore, the probability distribution profiles have been estimated to determine the most possible complex in the considered systems. The results establish structural and dynamical reformation of the Cu complex with change in the salt concentration or variation in the solvent medium in which they are dissolved. Moreover, the structure and kinetics of the Cu ions in the Cu-Cl electrolyzer have been explored over a large range of the electric field by extending the simulated systems for varied strengths of the electric fields. It has been observed that with an increase in the strength of the electric field, the water molecules lose their coordination strength with central Cu ions, which, on the other hand, results in a significant change in the structure of the captured complex. The diffusion dynamics of the ions is altered while applying the electric field, which is furthermore modified while increasing the strength of electric field beyond a critical limit. In fact, the diffusion mechanism of the ions was seen to be transformed from Brownian-like to linear motion and then to hopping diffusion with the increasing strength of the electric field. To the best of our knowledge, this is the first time when the multiple oxidation states of the Cu ion are explored using MD simulations, and the coexisting pictures of the multiple coordinations and the solvent effects have been clearly revealed. Also to date, the present article is the first one to report the insights of the structure and the dynamics of the ions in the Cu-Cl electrolyzer over a wide range of the electric field. The present studies will be very helpful in understanding the mechanism involved in numerous metal hydrometallurgical and sedimentary deposit processes and to comprehend the analogies involved in the electrode reactions of the Cu-Cl cycle for hydrogen generation.

10.
J Chem Phys ; 142(7): 074501, 2015 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-25702017

RESUMO

Thermodynamic properties of the fluid in the hydrophobic pores of nanotubes are known to be different not only from the bulk phase but also from other conventional confinements. Here, we use a recently developed theoretical scheme of "two phase thermodynamic (2PT)" model to understand the driving forces inclined to spontaneous filling of carbon nanotubes (CNTs) with polar (water) and nonpolar (methane) fluids. The CNT confinement is found to be energetically favorable for both water and methane, leading to their spontaneous filling inside CNT(6,6). For both the systems, the free energy of transfer from bulk to CNT confinement is favored by the increased entropy (TΔS), i.e., increased translational entropy and increased rotational entropy, which were found to be sufficiently high to conquer the unfavorable increase in enthalpy (ΔE) when they are transferred inside CNT. To the best of our knowledge, this is the first time when it has been established that the increase in translational entropy during confinement in CNT(6,6) is not unique to water-like H bonding fluid but is also observed in case of nonpolar fluids such as methane. The thermodynamic results are explained in terms of density, structural rigidity, and transport of fluid molecules inside CNT. The faster diffusion of methane over water in bulk phase is found to be reversed during the confinement in CNT(6,6). Studies reveal that though hydrogen bonding plays an important role in transport of water through CNT, but it is not the solitary driving factor, as the nonpolar fluids, which do not have any hydrogen bond formation capacity can go inside CNT and also can flow through it. The associated driving force for filling and transport of water and methane is enhanced translational and rotational entropies, which are attributed mainly by the strong correlation between confined fluid molecules and availability of more free space for rotation of molecule, i.e., lower density of fluid inside CNT due to their single file-like arrangement. To the best of our information, this is perhaps the first study of nonpolar fluid within CNT using 2PT method. Furthermore, the fast flow of polar fluid (water) over nonpolar fluid (methane) has been captured for the first time using molecular dynamic simulations.

11.
Appl Radiat Isot ; 97: 40-46, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25528019

RESUMO

An alkaline based continuous leaching process is commonly used for extraction of uranium from uranium ore. The reactor in which the leaching process is carried out is called a continuous leaching reactor (CLR) and is expected to behave as a continuously stirred tank reactor (CSTR) for the liquid phase. A pilot-scale CLR used in a Technology Demonstration Pilot Plant (TDPP) was designed, installed and operated; and thus needed to be tested for its hydrodynamic behavior. A radiotracer investigation was carried out in the CLR for measurement of residence time distribution (RTD) of liquid phase with specific objectives to characterize the flow behavior of the reactor and validate its design. Bromine-82 as ammonium bromide was used as a radiotracer and about 40-60MBq activity was used in each run. The measured RTD curves were treated and mean residence times were determined and simulated using a tanks-in-series model. The result of simulation indicated no flow abnormality and the reactor behaved as an ideal CSTR for the range of the operating conditions used in the investigation.

12.
J Mol Model ; 19(12): 5277-91, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24141630

RESUMO

The preferential selectivity of dicyclohexano-18-crown-6 (DCH18C6) for bivalent Sr(+2) ion over tetravalent Th(+4) ion was investigated using generalized gradient approximated (GGA) BP86 and the hybrid B3LYP density functional, employing split valence plus polarization (SV(P)) and triple-zeta valence plus polarization (TZVP) basis sets in conjunction with the COSMO (conductor-like screening model) solvation approach. The calculated theoretical selectivity of DCH18C6 for Sr(+2) ion over Th(+4) ion was found to be in accord with the selectivity for Sr(+2) ion over Th(+4) ion observed when performing liquid-liquid extraction experiments in different organic solvents. While 1:1(M:L) stoichiometric complexation reactions can be used to predict the preferential selectivity of Sr(2+) ion over Th(4+) ion, the results obtained are not consistent with the experimental results observed upon increasing the dielectric constant of the solvent. The calculated theoretical gas-phase data for the free energy of complexation, ∆G, fail to explain the selectivity for Sr(+2) ion over Th(+4) ion. However, when 1:2 (M:L) stoichiometric complexation reactions (reported in previous X-ray crystallography studies) are considered, correct and consistent results for the selectivity for Sr(+2) ion over a wide range of dielectric constants are predicted. The distribution constant for Sr(2+) and Th(4+) ions was found to gradually increase with increasing dielectric constant of the organic solvent, and was found to be highest in nitrobenzene. The selectivity data calculated from ∆∆G ext are in excellent agreement with the results obtained from solvent extraction experiments.

13.
Indian J Gastroenterol ; 31(4): 195-7, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22763897

RESUMO

Peritoneal tuberculosis, carcinomatosis and pancreatic ascites are often considered as differential diagnosis of hemorrhagic ascites. Endometriosis can rarely present as hemorrhagic ascites and closely mimic these conditions. When this occurs without common clinical features of endometriosis, it can create a diagnostic challenge to the treating physician. We present three patients with endometriosis who presented with hemorrhagic ascites; two of them did not have gynecological symptoms or significant pelvic disease. These patients were evaluated several times in many centers and even received multiple courses of anti-tuberculous treatment. The diagnosis was made by histologic examination of parietal peritoneum obtained by laparoscopy or laparotomy. The diagnosis was missed possibly because of the atypical presentation, lack of clinical suspicion and incomplete assessment. In conclusion, this potentially treatable condition should be considered as a differential diagnosis for hemorrhagic ascites in a premenopausal woman.


Assuntos
Ascite/diagnóstico , Endometriose/diagnóstico , Hemorragia Gastrointestinal/diagnóstico , Adulto , Ascite/etiologia , Ascite/cirurgia , Diagnóstico Diferencial , Endometriose/patologia , Endometriose/cirurgia , Feminino , Hemorragia Gastrointestinal/cirurgia , Humanos , Laparoscopia , Laparotomia
14.
Indian J Gastroenterol ; 30(3): 118-27, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21792655

RESUMO

BACKGROUND: Gastroesophageal reflux disease (GERD) and its complications are thought to be infrequent in India; there are no data from India on the prevalence of and risk factors for GERD. The Indian Society of Gastroenterology formed a task force aiming to study: (a) the frequency and profile of GERD in India, (b) factors including diet associated with GERD. METHODS: In this prospective, multi-center (12 centers) study, data were obtained using a questionnaire from 3224 subjects regarding the frequency, severity and duration of heartburn, regurgitation and other symptoms of GERD. Data were also obtained regarding their dietary habits, addictions, and lifestyle, and whether any of these were related or had been altered because of symptoms. Data were analyzed using univariate and multivariate methods. RESULTS: Two hundred and forty-five (7.6%) of 3224 subjects had heartburn and/or regurgitation at least once a week. On univariate analysis, older age (OR 1.012; 95% CI 1.003-1.021), consumption of non-vegetarian and fried foods, aerated drinks, tea/coffee were associated with GERD. Frequency of smoking was similar among subjects with or without GERD. Body mass index (BMI) was similar in subjects with and without GERD. On multivariate analysis, consumption of non-vegetarian food was independently associated with GERD symptoms. Overlap with symptoms of irritable bowel syndrome was not uncommon; 21% reported difficulty in passage of stool and 9% had mucus in stools. About 25% of patients had consulted a doctor previously for their gastrointestinal symptoms. CONCLUSION: 7.6% of Indian subjects have significant GERD symptoms. Consumption of non-vegetarian foods was an independent predictor of GERD. BMI was comparable among subjects with or without GERD.


Assuntos
Refluxo Gastroesofágico/diagnóstico , Refluxo Gastroesofágico/epidemiologia , Inquéritos e Questionários , Adulto , Dieta , Feminino , Refluxo Gastroesofágico/terapia , Azia/etiologia , Humanos , Índia/epidemiologia , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Perfil de Impacto da Doença , Sociedades Médicas
15.
Indian Pediatr ; 46 Suppl: s59-62, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19279372

RESUMO

This study was conducted to find out the anthropometric, biosocial and obstetric predictors of birthweight in Kerala. The study sample consisted of 599 consecutive liveborn babies delivered at SAT Hospital, Medical College, Thiruvananthapuram and their mothers in November 2001. Details of maternal history, anthropometry, and biosocial and demographic factors were recorded. Birthweight was primary outcome variable. Multivariate analysis revealed that the biologically acceptable predictors of birthweight of a baby in our population are maternal height (P <0.001), parity (P < 0.001) gestational age (P < 0.001), pregnancy induced hypertension(P=0.05) and history of low birthweight in the previous pregnancy(P=0.05).


Assuntos
Peso ao Nascer , Peso ao Nascer/fisiologia , Estatura , Estudos Transversais , Feminino , Idade Gestacional , Humanos , Índia , Recém-Nascido , Masculino , Mães , Análise Multivariada , Paridade , Gravidez
16.
Indian J Gastroenterol ; 27(1): 22-8, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18541934

RESUMO

AIMS: To study the profile of irritable bowel syndrome (IBS), and the frequency of such symptoms among the general population, in India. METHODS: In this prospective, multi-center study, data were obtained from 2785 patients with chronic lower gastrointestinal symptoms (complainants) with no alarm feature and negative investigations for organic causes visiting physicians at 30 centers, and from 4500 community subjects (non-complainants), using separate questionnaires. RESULTS: Most complainants were middle-aged (mean age 39.4 years) and male (1891; 68%). The common symptoms were: abdominal pain or discomfort (1958; 70%), abdominal fullness (1951; 70%); subjective feeling of constipation (1404 of 2656; 53%), or diarrhea (1252 of 2656, 47%), incomplete evacuation (2134; 77%), mucus with stools (1506; 54%), straining at stools (1271; 46%), epigastric pain (1364; 49%) and milk intolerance (906; 32%). Median stool frequency was similar in patients who felt they had constipation or those who felt they had diarrhea. Information to subtype symptoms using standard criteria was available in 1301 patients; of these, 507 (39%) had constipation-predominant IBS ( 3 3 stools/day) and 744 (57%) had indeterminate symptoms. Among non-complainants, most subjects reported daily defecation frequency of one (2520 [56%]) or two (1535 [34%]). Among non-complainants, 567 (12.6%) reported abdominal pain, 503 (11%) irregular bowel, 1030 (23%) incomplete evacuation, 167 (4%) mucus and 846 (18%) straining at stools; a combination of abdominal pain or discomfort relieved by defecation, and incomplete evacuation was present in 189/4500 (4.2%) community subjects. CONCLUSIONS: Most patients with IBS in India are middle-aged men, and have a sense of incomplete evacuation and mucus with stools. Abdominal pain or discomfort is frequent but not universal. Importantly, stool frequency was similar irrespective of whether the patients felt having constipation or diarrhea. Most (90%) non-complainant subjects had 1 or 2 stools per day; symptoms complex suggestive of IBS was present in 4.2% of community subjects.


Assuntos
Síndrome do Intestino Irritável/epidemiologia , Adulto , Feminino , Gastroenterologia , Humanos , Índia/epidemiologia , Síndrome do Intestino Irritável/fisiopatologia , Masculino , Estudos Prospectivos , Sociedades Médicas
17.
Indian J Med Res ; 123(6): 760-9, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16885597

RESUMO

BACKGROUND & OBJECTIVES: Hepatitis A is highly prevalent in India and mainly presents as a sporadic disease. This study investigated an outbreak of viral hepatitis at Medical College Hospital area, Kottayam, Kerala state, India during January 2005. METHODS: Blood (133), faecal (1), sewage (4), and water samples (13) were collected. Sera were tested for IgG- and IgM-anti-HAV and IgM antibodies against hepatitis E (IgM-anti-HEV). Sewage, faeces and water samples were tested for HAV RNA in nested RT-PCR and HAV RNA positive samples were further processed for RNA quantitation using Real Time PCR. RESULTS: Of the 1180 total cases, 540 were reported from Medical college area. Two deaths were reported among doctors. Patients from the community gave a previous history of visit to medical college hospital area. The sewage treatment plant at the campus was non-functional since 1990 and the untreated sewage was constantly overflowing and getting mixed with a canal. At the time of the study, all the water sources were superchlorinated. HAV RNA was present in the faeces of hepatitis A patient (1.36 x 10(7) copies/ml), sewage tank (2.57 x 10(3) copies/ml and the canal (<100 copies/ml). None of the 13 water samples concentrated 10,000-fold and the soil sample showed presence of HAV RNA. Phylogenetic analysis based on 5'-non-coding and P2 regions showed HAV-genotype IIIA in all samples. INTERPRETATION & CONCLUSION: The aetiological agent of the present outbreak was found to be HAV. Epidemic hepatitis A (genotype-IIIA) is emerging in Indian adults, emphasizing the need for definite policy for control.


Assuntos
Surtos de Doenças , Vírus da Hepatite A/genética , Hepatite A/epidemiologia , Hepatite A/imunologia , Anticorpos Antivirais/sangue , Sequência de Bases , Análise por Conglomerados , Primers do DNA , Fezes/virologia , Hepatite A/genética , Vírus da Hepatite A/imunologia , Vírus da Hepatite E/imunologia , Humanos , Índia/epidemiologia , Dados de Sequência Molecular , Filogenia , Prevalência , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Esgotos/virologia
18.
Curr Med Res Opin ; 22(4): 641-8, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16684424

RESUMO

BACKGROUND AND RATIONALE: Atherosclerotic vascular disease (AVD), including coronary heart disease (CHD), is on the rise in India. Mortality due to CHD is estimated to be 40% higher in Indian Asians compared with Europeans. Hyperhomocyst(e)inaemia (hypertHcy) is emerging as a novel independent risk factor for AVD. Moreover, there is increasing evidence of its association with CHD in subjects of Indian origin possibly because of inadequate folic acid and B(12) status. However, there is a lack of epidemiological data on its prevalence in Indians. A need to evaluate the optimum dose of folic acid required to reduce plasma homocyst(e)ine (tHcy) also exists. OBJECTIVES AND METHODS: The CARDIOVIT study, divided into two stages, is designed to determine the prevalence and relevance of hypertHcy in Indian subjects and also evaluate the tHcy-lowering effect of a marketed multivitamin formulation (Cardiovit). Stage I is a cross-sectional epidemiological study to estimate the prevalence of hypertHcy in a randomly selected population in South India. We planned to screen 2000 subjects between 25 and 64 years of age for established risk factors; plasma tHcy levels will be estimated and the correlation of AVD with established risk factors, plasma tHcy and nutritional factors was evaluated. Subjects having tHcy levels > 12 micromol/L are recruited in Stage II; a randomized, three-arm, double-blind, double-dummy, placebo-controlled, parallel-group, comparative study designed to evaluate the tHcy-lowering effect of a multivitamin formulation containing 300 microg folic acid, 1 microg vitamin B(12) and 1.5 mg vitamin B(6), along with Vitamins A, C, E and selenium. Subjects will be randomized into three groups (n = 64 completed subjects each) and receive either two placebos, or one placebo and multivitamin, or two multivitamin tablets for 6 weeks. Serum vitamin B(12), serum and red cell folate are estimated at baseline and at 6 weeks. Descriptive, univariate analysis, multiple logistic regression model and appropriate statistical tests will be used to analyse the prevalence of hypertHcy, association with risk factors of AVD, efficacy and safety of the multivitamin formulation and other data per protocol. CONCLUSIONS: CARDIOVIT is one of the first and largest studies in India to provide insight into the prevalence of hypertHcy, its association with AVD and conventional risk factors and the role of multivitamins in reducing it.


Assuntos
Aterosclerose/epidemiologia , Estudos Transversais , Suplementos Nutricionais , Hiper-Homocisteinemia/tratamento farmacológico , Hiper-Homocisteinemia/epidemiologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Vitaminas/uso terapêutico , Adulto , Antioxidantes/uso terapêutico , Aterosclerose/complicações , Aterosclerose/tratamento farmacológico , Feminino , Ácido Fólico/uso terapêutico , Homocisteína/sangue , Homocisteína/efeitos dos fármacos , Humanos , Hiper-Homocisteinemia/complicações , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Resultado do Tratamento , Complexo Vitamínico B/uso terapêutico
19.
J Periodontol ; 77(4): 692-8, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16584352

RESUMO

BACKGROUND: The microorganism Helicobacter pylori has been closely linked to chronic gastritis, peptic ulcer, gastric cancer, and mucosa-associated lymphoid tissue (MALT) lymphoma. Despite the current treatment regimens that lead to successful management of H. pylori-positive chronic gastritis, the reinfection rate is high. It has been suggested that one of the possible mechanisms of reinfection is the recolonization from dental plaque. The purpose of this study was to determine whether dental plaque, poor oral hygiene, and periodontal disease were risk factors for H. pylori infection. METHODS: Among the 134 patients, 65 patients who had a positive H. pylori serology or positive rapid urease test or histologic evidence for the presence of H. pylori in antral biopsy specimens were categorized as cases. The remaining 69 patients who were negative for H. pylori serology, the rapid urease test, and histology were controls. RESULTS: It was found that the association of periodontal disease and poor oral hygiene with H. pylori infection was not significant. There was a higher prevalence of H. pylori in the dental plaque of patients with gastric H. pylori infection than in controls, but both groups had a surprisingly high positive urease test for H. pylori in plaque (89% and 71%, respectively). CONCLUSIONS: H. pylori in dental plaque is seldom eliminated by H. pylori-eradication therapy, and this may act as a source for future reinfection. Hence, eradication of H. pylori from the dental plaque should be made an important part of comprehensive management of H. pylori-associated gastric diseases.


Assuntos
Placa Dentária/complicações , Placa Dentária/microbiologia , Infecções por Helicobacter/etiologia , Helicobacter pylori/isolamento & purificação , Doenças Periodontais/complicações , Adolescente , Adulto , Idoso , Análise de Variância , Animais , Estudos de Casos e Controles , Reservatórios de Doenças , Feminino , Gastrite/microbiologia , Infecções por Helicobacter/transmissão , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Higiene Bucal , Fatores de Risco , Fatores Socioeconômicos , Urease/metabolismo , Zoonoses/microbiologia
20.
J Indian Med Assoc ; 101(6): 387-8, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-14579989

RESUMO

To document the clinical efficacy and tolerability of itopride hydrochloride in patients with non-ulcer dyspepsia an open-label, non-comparative study, was undertaken at the Medical College, Thiruvananthapuram, among patients with endoscopically confirmed diagnosis of non-ulcer dyspepsia or chronic gastritis. Itopride hydrochloride 50 mg (1 tablet) thrice a day for 2 weeks was administered among them. Relief of symptoms at the end of two weeks treatment, assessed as marked/complete, moderate, slight, none or worse; QT interval on ECG; adverse events; haemogram; serum chemistry for hepatic and renal functions. None had QT prolongation on ECG. At the end of 2 weeks' treatment, moderate to complete relief of symptoms was reported by 22 patients (73%), whereas 5 (17%) reproted slight improvement, and 3 (10%) reported no improvement. Clinical tolerability was excellent in 28 patients (93%) and good in 2 (7%). None of the patients had any prolongation of QT on ECG, nor did any patient show any abnormality in haemogram or serum chemistry during the treatment.


Assuntos
Benzamidas/uso terapêutico , Compostos de Benzil/uso terapêutico , Dispepsia/tratamento farmacológico , Adulto , Benzamidas/efeitos adversos , Compostos de Benzil/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
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