RESUMO
The human fetal immune system begins to develop early during gestation; however, factors responsible for fetal immune-priming remain elusive. We explored potential exposure to microbial agents in utero and their contribution toward activation of memory T cells in fetal tissues. We profiled microbes across fetal organs using 16S rRNA gene sequencing and detected low but consistent microbial signal in fetal gut, skin, placenta, and lungs in the 2nd trimester of gestation. We identified several live bacterial strains including Staphylococcus and Lactobacillus in fetal tissues, which induced in vitro activation of memory T cells in fetal mesenteric lymph node, supporting the role of microbial exposure in fetal immune-priming. Finally, using SEM and RNA-ISH, we visualized discrete localization of bacteria-like structures and eubacterial-RNA within 14th weeks fetal gut lumen. These findings indicate selective presence of live microbes in fetal organs during the 2nd trimester of gestation and have broader implications toward the establishment of immune competency and priming before birth.
Assuntos
Bactérias/metabolismo , Desenvolvimento Embrionário , Feto/citologia , Feto/microbiologia , Leucócitos/citologia , Adulto , Bactérias/genética , Bactérias/ultraestrutura , Proliferação de Células , Células Dendríticas/metabolismo , Feminino , Feto/ultraestrutura , Trato Gastrointestinal/embriologia , Trato Gastrointestinal/ultraestrutura , Humanos , Memória Imunológica , Ativação Linfocitária/imunologia , Viabilidade Microbiana , Gravidez , Segundo Trimestre da Gravidez , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Reprodutibilidade dos Testes , Linfócitos T/citologiaRESUMO
Understanding and characterizing multistabilities, whether homogeneous or heterogeneous, is crucial in various fields as it helps to unveil complex system behaviors and provides insights into the resilience and adaptability of these systems when faced with perturbations or changes. Homogeneous and heterogeneous multistabilities refer, respectively, to situation in which various multiple stable states within a system are qualitatively similar or distinct. Generating such complex phenomena with multi-scrolls from inherent circuits is less reported. This paper aims to investigate extreme multistability dynamics with homogeneous and heterogeneous multi-scrolls in two coupled resonant oscillators through a shunted Josephson junction. Analysis of equilibrium points revealed that the system supports both hidden and self-excited attractors. Various dynamical tools, including bifurcation diagrams, spectrum of Lyapunov exponents, and phase portraits, are exploited to establish the connection between the system parameters and various complicated dynamical features of the system. By tuning both system parameters and initial conditions, some striking phenomena, such as homogeneous and heterogeneous extreme multistability, along with the emergence of multi-scrolls, are illustrated. Furthermore, it is observed that one can readily control the number of scrolls purely by varying the initial conditions of the investigated system. A multi-metastable phenomenon is also captured in the system and confirmed using the finite-time Lyapunov exponents. Finally, the microcontroller implementation of the system demonstrates strong alignment with the numerical investigations.
RESUMO
Achieving synchronization in coupled non-identical chaotic systems has been a difficult endeavor, and improving the stability of synchronization in such systems poses additional challenges. This research work addresses these challenges by identifying stable synchronization in coupled non-identical chaotic systems and enhancing its stability. The study explores chaotic attractors that arise from various system parameters to provide generalized results. Furthermore, the impact of the transient uncoupling factor on improving synchronization stability in coupled non-identical counter-rotating chaotic oscillators is discussed. By investigating these aspects, the research aims to contribute to the understanding and advancement of synchronization in coupled non-identical chaotic systems.
RESUMO
In recent times, equivalent source method-based near-field acoustic holography methods have been extensively applied in sound source localization and characterization. The most commonly used equivalent sources are spherical harmonics. In a non-reverberant environment with no reflections, these equivalent sources could be the best choice since spherical harmonics are derived for the Sommerfeld boundary condition. However, these methods are not the best fit for reverberating environments. In such cases, a new relationship can be calculated between the field weights and the measured pressure with enough training examples. The proposed machine learning models include linear regression (LR) with adaptive moment estimation (Adam), LR with limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS), and multi-layer perceptron with one and two hidden layers. These methods are tested for multiple monopoles and vibrating plate simulations in a room with different wall absorption coefficients. The data-driven methods are also studied on loudspeakers numerically and experimentally in a free field environment. The results from these methods are compared with the results of one norm convex optimization (L1CVX). LR with L-BFGS performed the best among all the methods studied and performed better than L1CVX for less absorption coefficient for geometrically separable sources. LR with L-BFGS also has much faster inference times.
RESUMO
In the present scenario, a considerable assiduity is provided to develop novel human-machine interface technologies that rapidly outpace the capabilities of display technology in automotive industries. It is necessary to use a new cockpit design in conjunction with a fully automated driving environment in order to enhance the driving experience. It can create a seamless and futuristic dashboard for automotive infotainment application. In the present study, an endeavor was made to equip the In-vehicle bezels with printed capacitive sensors for providing superior sensing capabilities. Silver Nanoparticles based interdigitated pattern electrodes were formed over polycarbonate substrates to make printed capacitive sensors using screen printing process. The developed sensor was investigated to evaluate the qualitative and quantitative measures using direct and in-direct contact of touch. The proposed approach for sensors pattern and fabrication can highly impact on sensor performance in automotive infotainment application due to the excellent spatial interpolation with lower cost, light weight, and mechanical flexibility.
Assuntos
Nanopartículas Metálicas , Percepção do Tato , Eletrodos , Humanos , Prata , TatoRESUMO
Major Depressive Disorder (MDD) is associated with low rates of treatment and medication non-adherence, more so in low- and middle-income countries (LMICs). Mobile mental health (mHealth) interventions offer promise as a tool to address these problems. However, the feasibility and acceptability of mHealth interventions among rural women in LMICs is unknown. We examined barriers to accessing mental health treatment, reasons for non-adherence, and attitudes towards mHealth solutions among women with MDD in rural south India. Six focus groups were conducted among women with MDD (n = 69) who had been in treatment at a rural community health center. The discussion was transcribed and analyzed using a modified grounded-theory approach. Women perceived limited autonomy within their family structure, and experienced financial and systemic barriers as contributing to poor treatment access and non-adherence. Illiteracy, limited personal access to mobile phones, and preference for in-person clinical consultation were identified as barriers to use of mHealth. This is the first qualitative study, to our knowledge, that examines attitude towards mHealth among women with MDD in a rural setting in India. The study identified contextual barriers that will be important to address before implementing mHealth interventions.
Assuntos
Telefone Celular , Transtorno Depressivo Maior/terapia , Acessibilidade aos Serviços de Saúde , Telemedicina/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Serviços Comunitários de Saúde Mental , Feminino , Grupos Focais , Humanos , Índia , Pessoa de Meia-Idade , Pobreza , Pesquisa Qualitativa , População Rural , Adulto JovemRESUMO
Mechanical modes are a potentially useful resource for quantum information applications, such as quantum-level wavelength transducers, due to their ability to interact with electromagnetic radiation across the spectrum. A significant challenge for wavelength transducers is thermomechanical noise in the mechanical mode, which pollutes the transduced signal with thermal states. In this Letter, we eliminate thermomechanical noise in the GHz-frequency mechanical breathing mode of a piezoelectric optomechanical crystal using cryogenic cooling in a dilution refrigerator. We optically measure an average thermal occupancy of the mechanical mode of only 0.7±0.4 phonons, providing a path towards low-noise microwave-to-optical conversion in the quantum regime.
RESUMO
Significant efforts have been made to address the hidden hunger challenges due to iron, zinc, iodine, and vitamin A since the beginning of the 21st century. Prioritizing the vitamin A deficiency (VAD) disorders, many countries are looking for viable alternative strategies such as biofortification. One of the leading causes of VAD is the poor bioconversion of ß-carotene into retinoids. This review is focused on the opportunities of bacterial biosynthesis of retinoids, in particular, through the gut microbiota. The proposed hypothesis starts with the premise that an animal can able to store and timely convert carotenoids into retinoids in the liver and intestinal tissues. This theory is experimental with many scientific insights. The syntrophic metabolism, potential crosstalk of bile acids, lipocalins and lipopolysaccharides of gut microbiota are reported to contribute significantly to the retinoid biosynthesis. The gut bacteria respond to these kinds of factors by genetic restructuring driven mainly by events like horizontal gene transfer. A phylogenetic analysis of ß-carotene 15, 15'-mono (di) oxygenase enzymes among a selected group of prokaryotes and eukaryotes was carried out to validate the hypotheses. Shedding light on the probiotic strategies through non-genetically modified organism such as gut bacteria capable of synthesizing vitamin A would address the VAD disorders.
Assuntos
Bactérias/metabolismo , Vitamina A/biossíntese , Animais , Microbioma Gastrointestinal , Humanos , Deficiência de Vitamina ARESUMO
This article extends the research focusing on the early origins of psychopathology into the prenatal period, by exploring the association between maternal prenatal depression and offspring (fetal and infant) neurobehavior. The sample is recruited from a rural population in South India where women in the third trimester of pregnancy were assessed for depression and the heart rate responses of their fetuses to extrinsically applied vibroacoustic stimuli were studied. At 2 months postbirth, infant temperament and cortisol responsivity to immunization were assessed. The association between maternal prenatal depression and fetal responsivity to vibroacoustic stimulation, and infant responsivity to immunization, was U shaped with higher levels of responsivity noted in the offspring of mothers with very high and very low depression scores, and lower levels noted in the offspring of mothers with moderate depression scores. Maternal prenatal depression was not associated with infant temperament. The findings highlight the importance of environmental influences in the developmental origins of neurobehavior, suggesting that such differences, not evident at baseline, may emerge upon exposure to stressors. The study also emphasizes the need for further investigation in low- and middle-income contexts by providing preliminary evidence of the differing patterns of association observed between high- and low-income populations.
Assuntos
Transtorno Depressivo/fisiopatologia , Transtornos do Neurodesenvolvimento/fisiopatologia , Complicações na Gravidez/fisiopatologia , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Temperamento/fisiologia , Populações Vulneráveis , Adulto , Estudos de Coortes , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/psicologia , Feminino , Humanos , Hidrocortisona/sangue , Índia , Lactente , Recém-Nascido , Transtornos do Neurodesenvolvimento/diagnóstico , Transtornos do Neurodesenvolvimento/psicologia , Pobreza/psicologia , Gravidez , Complicações na Gravidez/diagnóstico , Complicações na Gravidez/psicologia , Efeitos Tardios da Exposição Pré-Natal/psicologia , População Rural , Populações Vulneráveis/psicologiaRESUMO
A series of 3-Benzylchroman-4-ones were synthesized and screened for anticancer activity by MTT assay. The compounds were evaluated against two cancerous cell lines BT549 (human breast carcinoma), HeLa (human cervical carcinoma), and one noncancerous cell line vero (normal kidney epithelial cells). 3b was found to be the most active molecule against BT549 cells (IC50â¯=â¯20.1⯵M) and 3h against HeLa cells (IC50â¯=â¯20.45⯵M). 3b also exhibited moderate activity against HeLa cells (IC50â¯=â¯42.8⯵M). The molecular structures of 3h and 3i were solved by single crystal X-ray crystallographic technique. Additionally, the molecular docking studies between the tumour suppressor protein p53 with the lead compound 3h, which exhibited better anticancer activity against HeLa cells was examined.
Assuntos
Antineoplásicos/farmacologia , Simulação de Acoplamento Molecular , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Chlorocebus aethiops , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Relação Estrutura-Atividade , Células VeroRESUMO
OBJECTIVE: South Asians are a high-risk group for type 2 diabetes and coronary heart disease. We sought to determine ethnic differences in newborn adiposity comparing South Asians (SA) to White Caucasians (Whites). METHODS: Seven hundred ninety pregnant women (401 SA, 389 Whites) and their full-term offspring from two birth cohorts in Canada were analyzed. Pregnant women completed a health assessment including a 75-g oral glucose tolerance test to assess for dysglycemia. Birthweight, length, waist and hip circumference, and triceps and subscapular skinfold thickness (a surrogate measure of body adiposity) were measured in all newborns. Multivariate regression was used to identify maternal factors associated with newborn skinfold measurements. RESULTS: South Asian women were younger (30.1 vs 31.8 years, P<0.001), their prepregnancy body mass index was lower (23.7 vs 26.2, P<0.0001) and gestational diabetes was substantially higher (21% vs 13%, P=0.005) compared with Whites. Among full-term newborns, South Asians had lower birthweight (3283 vs 3517 g, P=0.0001), had greater skinfold thickness (11.7 vs 10.6 mm; P=0.0001) and higher waist circumference (31.1 vs 29.9 cm, P=0.0001) compared with Whites. Risk factors for newborn skinfold thickness included South Asian ethnicity (standardized estimate (s.e.): 0.24; P<0.0001), maternal glucose (s.e.: 0.079; P=0.04) and maternal body fat (s.e.: 0.14; P=0.0002). CONCLUSIONS: South Asian newborns are lower birthweight and have greater skinfold thickness, compared with White newborns, and this is influenced by maternal body fat and glucose. Interventions aimed at reducing body fat prior to pregnancy and gestational diabetes during pregnancy in South Asians may favorably alter newborn body composition and require evaluation.
Assuntos
Tecido Adiposo/metabolismo , Povo Asiático , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Gestacional/metabolismo , Suscetibilidade a Doenças/etnologia , Obesidade/metabolismo , Gestantes/etnologia , População Branca , Adulto , Composição Corporal , Canadá/epidemiologia , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/etnologia , Diabetes Gestacional/epidemiologia , Diabetes Gestacional/etnologia , Feminino , Teste de Tolerância a Glucose , Humanos , Recém-Nascido , Masculino , Obesidade/epidemiologia , Obesidade/etnologia , Gravidez , Estudos Prospectivos , Dobras CutâneasRESUMO
A rapid and sensitive fluorescent sensor based on the MoS2 nanosheet/DNA/carbon dot nanoassembly has been developed towards the detection of mercury(ii) present in environmental samples. Bio-carbon dots (CDs) having strong fluorescence maxima at 451 nm were synthesized via one-step treatment with honey under low temperature carbonization. These CDs were nearly spherical with good size distribution and excellent monodispersity, and the average sizes of CD were around 2-4 nm as evidenced from transmission electron microscopy. The conjugation of DNA strands on the surface of the carbon dots provided an efficient fluorescent probe. The fluorescence of the MoS2 nanosheet/DNA/carbon dot nanoassembly enhanced gradually with the increase in the concentration of Hg2+ ions and the detection limit was found to be 1.02 nM. Furthermore, the fluorescence intensity was found to be linear with the concentration of Hg2+ ions in the range from 0 to 10 nM and their respective coefficient of determination was found to be 0.93676 and 0.98178. The present MoS2 nanosheet/DNA/carbon dot nanoassembly is highly selective toward Hg2+ ions over a wide range of metal ions tested.
Assuntos
Carbono , DNA/química , Mercúrio/análise , Pontos Quânticos , Corantes Fluorescentes , Espectrometria de FluorescênciaRESUMO
PURPOSE: To quantitatively evaluate the diffusion tensor metrics p, q, L and fractional anisotropy in intracranial epidermoids in comparison with normal white matter in the splenium of the corpus callosum. METHODS: This retrospective study included 20 consecutive patients referred to our institute. All patients had a magnetic resonance imaging (MRI) study on a 1.5-Tesla MR system. A spin-echo echo-planar DTI sequence with diffusion gradients along 30 non-collinear directions was performed. The eigen values (λ1, λ2, λ3) were computed for each voxel and, using p: q tensor decomposition, the DTI metrics p, q and L-values and fractional anositropy (FA) were calculated. The region of interest (ROI) (6 pixels each) was placed within the lesion in all the cases and in the splenium of the corpus callosum. RESULTS: The mean FA in the lesion and splenium were 0.50 and 0.88 respectively, with a statistically significant difference between them (P<0.01). On p: q tensor decomposition, the mean p-value in the epidermoid was 1.55±0.24 and 1.35±0.20 in the splenium; the mean q-values in the epidermoid was 0.67±0.13 and 1.27±0.17 in the splenium; the differences were statistically significant (P=0.01 and <0.01 respectively). The significant difference between p- and q-values in epidermoids compared with the splenium of callosum was probably due to structural and orientation differences in the keratin flakes in epidermoids and white matter bundles in the callosum. However, no significant statistical difference in L-values was noted (P=0.44). CONCLUSION: DTI metrics p and q have the potential to quantify the diffusion and anisotropy in various tissues thereby gaining information about their internal architecture. The results also suggest that significant differences of DTI metrics p and q between epidermoid and the splenium of the corpus callosum are due to the difference in structural organization within them.
Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Carcinoma de Células Escamosas/diagnóstico por imagem , Carcinoma de Células Escamosas/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Imagem de Tensor de Difusão/métodos , Adulto , Anisotropia , Corpo Caloso/anatomia & histologia , Corpo Caloso/diagnóstico por imagem , Feminino , Humanos , Estudos RetrospectivosRESUMO
Moringa oleifera is an affordable and rich source of dietary folate. Quantification of folate by HPLC showed that 5-formyl-5,6,7,8-tetrahydrofolic acid (502.1 µg/100 g DW) and 5,6,7,8-tetrahydrofolic acid (223.9 µg/100 g DW) as the most dominant forms of folate in M. oleifera leaves. The bioavailability of folate and the effects of folate depletion and repletion on biochemical and molecular markers of folate status were investigated in Wistar rats. Folate deficiency was induced by keeping the animals on a folate deficient diet with 1 % succinyl sulfathiazole (w/w). After the depletion period, animals were repleted with different levels of folic acid and M. oleifera leaves as a source of folate. Feeding the animals on a folate deficient diet for 7 weeks caused a significant (3.4-fold) decrease in serum folate content, compared to non-depleted control animals. Relative bioavailability of folate from dehydrated leaves of M. oleifera was 81.9 %. During folate depletion and repletion, no significant changes in liver glycine N-methyl transferase and 5-methyltetrahydrofolate-homocysteine methyltransferase expression were recorded. In RDA calculations, only 50 % of natural folate is assumed to be bioavailable. Therefore, the bioavailability of folate from Moringa is much higher, suggesting that M. oleifera based food can be used as a significant source of folate.
RESUMO
The agricultural wastes like Citrus Limettioides peel and seed to be suitable precursor for the preparation of carbon [Citrus Limettioides peel carbon (CLPC) and seed carbon (CLSC)] has been explored in the present work, utilizing sulfuric acid as the activating agent. Adsorption studies were performed by varying contact time, solution pH, adsorbent dose and temperature. The equilibrium time for Ni(II) ions was determined as 4h and optimal pH was 4-7. Surface morphology and functionality of the CLPC and CLSC were characterized by SEM, EDX and FT-IR. The experimental data were analysed using the Freundlich, Langmuir, Temkin, Redlich-Peterson, Sips and Dubinin-Radushkevich adsorption isotherm equations using nonlinear regression analysis. Equilibrium data were found to fit well in the Langmuir isotherm, which confirmed the monolayer coverage of Ni(II) ions. The Langmuir monolayer adsorption capacity of CLPC and CLSC was found to be 38.46 and 35.54 mg/g. The thermodynamic parameters indicated that the adsorption process was spontaneous and exothermic in nature. The kinetic data followed pseudo-second order model with film diffusion process. The adsorbents were tested with Ni(II) plating wastewater in connection with the reuse and selectivity of the adsorbents.
Assuntos
Carvão Vegetal/química , Citrus/química , Frutas/química , Níquel/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Carbono , Concentração de Íons de Hidrogênio , Íons , Cinética , Sementes , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier , Ácidos Sulfúricos , Temperatura , TermodinâmicaRESUMO
BACKGROUND: Maternal depression during pregnancy is associated with an increased risk of adverse child outcomes. One potential mechanism is the influence of antenatal depression on the foetal hypothalamic-pituitary-adrenal axis. This can be observed as disturbances in baseline cortisol secretion during childhood. The influence of antenatal depression on infant cortisol reactivity to a stressor may provide further insight into this association. In addition, the dose-response relationship between foetal exposure to antenatal depression and infant cortisol reactivity is unclear. METHODS: A consecutive sample of 133 pregnant women in their third trimester was recruited from an antenatal clinic in Karnataka, South India. Women were assessed for depression before and after birth on the Edinburgh Postnatal Depression Scale (EPDS) and the Kessler 10 Scale. Salivary cortisol response to immunization was measured in 58 infants at 2 months of age. We aimed (i) to investigate the association between antenatal depression and infant cortisol reactivity to immunization and (ii) to explore whether the relationship is dose-dependent. RESULTS: Exposure to antenatal depression independently predicted elevated infant cortisol responses to immunization (ß = 0.53, P = 0.04). The association was found to be U-shaped, for antenatal depression measured on the EPDS, with the infants exposed to the highest and lowest levels of maternal antenatal EPDS scores during intra-uterine life showing elevated cortisol responses to immunization (R(2) = 0.20, P = 0.02). Infants exposed to moderate levels of maternal antenatal depression showed the lowest cortisol response to immunization. CONCLUSIONS: These findings suggest that the association between antenatal depression and infant cortisol reactivity is dose-dependent and U-shaped, implying that infants exposed to both low and high levels of maternal depression showed greater reactivity. The study provides the first evidence of such an association from a low-income setting.
Assuntos
Depressão/imunologia , Hidrocortisona/metabolismo , Sistema Hipófise-Suprarrenal/imunologia , Complicações na Gravidez/imunologia , Gestantes , Efeitos Tardios da Exposição Pré-Natal/imunologia , Adulto , Formação de Anticorpos/imunologia , Linfócitos T CD4-Positivos , Depressão/epidemiologia , Depressão/fisiopatologia , Relação Dose-Resposta Imunológica , Feminino , Humanos , Imunização , Índia/epidemiologia , Recém-Nascido , Ativação Linfocitária , Masculino , Sistema Hipófise-Suprarrenal/fisiopatologia , Gravidez , Terceiro Trimestre da Gravidez , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Efeitos Tardios da Exposição Pré-Natal/fisiopatologiaRESUMO
Excessive free radical generation overbalancing the rate of their removal leads to oxidative stress. Oxidative stress has been implicated in the etiology of cardiovascular disease, inflammatory diseases, cancer, and other chronic diseases. Antioxidants are compounds that hinder the oxidative processes and thereby delay or suppress oxidative stress. There is a growing interest in natural antioxidants found in plants. Herbs and spices are most important targets to search for natural antioxidants from the point of view of safety. A wide variety of phenolic compounds present in spices that are extensively used as food adjuncts possess potent antioxidant, anti-inflammatory, antimutagenic, and cancer preventive activities. This paper reviews a host of spice compounds as exogenous antioxidants that are experimentally evidenced to control cellular oxidative stress, both in vitro and in vivo, and their beneficial role in preventing or ameliorating oxidative-stress-mediated diseases, from atherosclerosis to diabetes to cataract to cancer. The antioxidative effects of turmeric/curcumin, clove/eugenol, red pepper/capsaicin, black pepper/piperine, ginger/gingerol, garlic, onion, and fenugreek, which have been extensively studied and evidenced as potential antioxidants, are specifically reviewed in this treatise.
Assuntos
Antioxidantes , Especiarias/análise , Alcaloides , Anti-Inflamatórios , Antimutagênicos , Benzodioxóis , Capsaicina , Cardiotônicos , Catecóis , Curcumina , Eugenol , Álcoois Graxos , Alho , Humanos , Neoplasias/prevenção & controle , Cebolas , Estresse Oxidativo , Fenóis , Piperidinas , Alcamidas Poli-Insaturadas , TrigonellaRESUMO
BACKGROUND & OBJECTIVES: Nicotine dependence is a widely prevalent and harmful chronic addictive disorder. Quitting tobacco use is however, uncommon in India. We present long-term treatment outcomes of out-patient, tobacco cessation treatments from a specialty clinic setting in southern India. METHODS: Patients seen in a tobacco cessation clinic were characterized for tobacco use, nicotine dependence and motivation for quitting and offered pharmacologic/non-pharmacologic treatment. They were subsequently contacted telephonically at a mean (±standard deviation) of 24 (±9.1) months to assess tobacco cessation outcome defined as 'point prevalence of 1-month abstinence' by self-reporting. RESULTS: The mean age of participants was 48.0 ±14.0 yr. Tobacco use distribution was: beedis only (22%), cigarettes only (49%), beedis and cigarettes (18%), chewing only (2%), and smoking and chewing (9%). Two-thirds had high level of nicotine dependence. Of the 189 patients enrolled, only 15 per cent attended follow up clinics. Only 106 (56%) patients were successfully contacted telephonically and 83 (44%) were lost to follow up. Self-reported point prevalence abstinence was 5 per cent by 'intent-to-treat' analysis and 10 per cent by 'responder' analysis. Two clinical parameters - high level of nicotine dependence [estimated by the heaviness of smoking index (HSI)] and the absence of vascular or other chronic disease were found to be associated with successful quitting; these were however, not significant on multivariate analysis. INTERPRETATION & CONCLUSIONS: Our study has identified low quit-rates in a cohort of patients attending a hospital-based tobacco cessation clinic. In the absence of clear-cut predictors of cessation with low quit-rates, there should be continued efforts to improve cessation outcomes and identify predictors for action.