100 research outputs found

    Human beings as islands of stability: Monitoring body states using breath profiles

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    By checking the reproducibility of conventional mid-infrared Fourier spectroscopy of human breath in a small test study (15 individuals), we found that a set of volatile organic compounds (VOC) of the individual breath samples remains reproducible at least for 18 months. This set forms a unique individual's "island of stability" (IOS) in a multidimensional VOC concentration space. The IOS stability can simultaneously be affected by various life effects as well as the onset of a disease. Reflecting the body state, they both should have different characteristics. Namely, they could be distinguished by different temporal profiles: In the case of life effects (beverage intake, physical or mental exercises, smoking etc.), there is a non-monotonic shift of the IOS position with the return to the steady state, whereas a progressing disease corresponds to a monotonic IOS shift. As a first step of proving these dependencies, we studied various life effects with the focus on the strength and characteristic time of the IOS shift. In general, our results support homeostasis on a long time scale of months, allostasis on scales of hours to weeks or until smoke quitting for smokers, as well as resilience in the case of recovery from a disease

    Reaction of dehydroacetic acid with aliphatic, aromatic and heterocyclic amines

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    710-71

    Sensitive spectroscopic breath analysis by water condensation

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    Breath analysis has great potential for becoming an important clinical diagnosis method due to its friendly and non-invasive way of sample collection. Hundreds of endogenous trace gases (volatile organic compounds (VOCs)) are present in breath, representing different metabolic processes of the body. They are not only characteristic for a person, their age, sex, habit etc, but also specific to different kinds of diseases. VOCs, related to diseases could serve as biomarkers for clinical diagnostics and disease monitoring. However, due to the large amount of water contained in breath, an identification of specific VOCs is a real challenge. In this work we present a technique of water suppression from breath samples, that enables us to identify several trace gases in breath, e.g., methane, isoprene, acetone, aldehyde, carbon monoxide, etc, using Fourier-transform infrared spectroscopy. In the current state, the technique reduces the water concentration by a factor of 2500. Sample preparation and data acquisition take about 25 min, which is clinically relevant. In this article we demonstrate the working principle of the water reduction technique. Further, with specific examples we demonstrate that water elimination from breath samples does not hamper the concentration of trace gases in breath. Preliminary experiments with real breath also indicate that the concentrations of methane, acetone and isoprene remain the same during the sample preparation

    Significant association of the dupA gene of Helicobacter pylori with duodenal ulcer development in a South-east Indian population

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    A novel virulence factor, duodenal ulcer-promoting gene A (dupA), in Helicobacter pylori has been found to be associated with disease in certain populations but not in others. This study analysed a South-east Indian population as part of the debate about the relevance of dupA for the prediction of clinical outcomes. A total of 140 H. pylori strains isolated from duodenal ulcer (DU) (n=83) and non-ulcer dyspepsia (NUD) patients (n=57) were screened by PCR and dot-blot hybridization to determine the presence of the ORFs jhp0917 and jhp0918. Part of jhp0917-jhp0918 was sequenced to search for the C/T insertion that characterizes dupA and the levels of dupA transcripts were also assessed. The PCR and dot-blot results indicated the presence of jhp0917 and jhp0918 in 37.3% (31/83) and 12.2% (7/57) of H. pylori strains isolated from DU and NUD patients, respectively. Sequencing analysis showed insertion of a C at nt 1386 in the 3' region of jhp0917, forming the dupA gene in 35 strains. RT-PCR analysis detected the dupA transcript in 28 of these 35 strains. The expression level of the dupA transcript varied from strain to strain, as shown by real-time PCR. The results demonstrated that analysis based on PCR only for dupA may produce an erroneous interpretation. The prevalence of dupA was significantly greater among strains isolated from patients with DU than from patients with NUD in this population (P=0.001, odds ratio=4.26, confidence interval=1.60-11.74). Based on these findings, dupA can be considered a biomarker for DU patients in India. The reported discrepancies for this putative virulence marker in different populations may be due to the genome plasticity of H. pylori

    Plant-Mediated Synthesis of Silver Nanoparticles: Their Characteristic Properties and Therapeutic Applications

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    Non-Invasive Disease Specific Biomarker Detection Using Infrared Spectroscopy: A Review

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    Many life-threatening diseases remain obscure in their early disease stages. Symptoms appear only at the advanced stage when the survival rate is poor. A non-invasive diagnostic tool may be able to identify disease even at the asymptotic stage and save lives. Volatile metabolites-based diagnostics hold a lot of promise to fulfil this demand. Many experimental techniques are being developed to establish a reliable non-invasive diagnostic tool; however, none of them are yet able to fulfil clinicians’ demands. Infrared spectroscopy-based gaseous biofluid analysis demonstrated promising results to fulfil clinicians’ expectations. The recent development of the standard operating procedure (SOP), sample measurement, and data analysis techniques for infrared spectroscopy are summarized in this review article. It has also outlined the applicability of infrared spectroscopy to identify the specific biomarkers for diseases such as diabetes, acute gastritis caused by bacterial infection, cerebral palsy, and prostate cancer

    Effect of Vegetation Cover on Sediment Yield: An Empirical Study through Plots Experiment

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    Rill and gully erosion is a critical environmental problem in India, where vegetal cover plays vital role in the runoff and soil loss reduction and stabilization of disturbed systems. Here, the impact of vegetal cover on runoff and soil erosion in lateritic environment was assessed through experimental observation on five plots (<5 m2 area), containing varied vegetal cover at successive time period. Runoff and rate of soil loss were measured in each plot under seven natural rain storm conditions and compared them. The observed data showed bare plots experienced larger sediment yield than they are with vegetal cover. The simulation results corroborated significant relationship between the soil detachment and explanatory variables, e.g. runoff volume and vegetal cover (R2= 0.95; P<0.001). A very significant relationship was found between vegetal cover and sediment concentration (Adjusted R2= 0.91, P<0.001). This plot-scale study has the advantage of allowing for detailed process monitoring at micro scale, providing a basic description of the most relevant aspect of vegetal cover on sediment yield. Keywords: Rill-gully erosion; lateritic environment; sediment yield; vegetation cove

    Synthesis and characterization of phosphorus containing adhesive polymers

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    103-111Synthesis of phosphorus containing epoxy terminated polymers from dichlorophenyl phosphine oxide, various diols like bisphenol-A, resorcinol, 4-4' thiodiphenol and 4-4' sulphone diphenol and epichlorohydrin was carried out by the interfacial polymerization process. These polymers were characteri zed by viscosity measurement, elemental analyses, Schoniger combustion method, 1H-NMR, 13C-NMR and 31P-NMR analyses. These resulting polymers were highly soluble in polar solvents like DMF, DMSO, NMP, HMPA, and acetone etc
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