The Experts below are selected from a list of 114 Experts worldwide ranked by ideXlab platform
Joel N Bixler - One of the best experts on this subject based on the ideXlab platform.
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ultrasensitive detection of waste products in water using fluorescence emission cavity enhanced spectroscopy
Proceedings of the National Academy of Sciences of the United States of America, 2014Co-Authors: Joel N Bixler, Michael T Cone, Brett H Hokr, John D Mason, Eleonora FigueroaAbstract:Clean water is paramount to human health. In this article, we present a technique for detection of trace amounts of human or animal waste products in water using fluorescence emission cavity-enhanced spectroscopy. The detection of femtomolar concentrations of Urobilin, a metabolic byproduct of heme metabolism that is excreted in both human and animal waste in water, was achieved through the use of an integrating cavity. This technique could allow for real-time assessment of water quality without the need for expensive laboratory equipment.
Ashok Kumar Mishra - One of the best experts on this subject based on the ideXlab platform.
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understanding the photophysics of stercobilin zn ii and Urobilin zn ii complexes towards faecal pigment analysis
Chemosphere, 2021Co-Authors: Swayam Prakash, Suraj Kumar Panigrahi, Rebecca Paulina Dorner, Martin Wagner, Wido Schmidt, Ashok Kumar MishraAbstract:A detailed photophysical study of two faecal pigments (FPs), Urobilin (UB) and Stercobilin (SB), and their zinc complexes [FP-Zn(II)] was carried out. The enhancement of UB and SB fluorescence resulting from the formation of their Zn(II) complexes was attributed to the complexation-induced rigidity of the chromophoric units, and the corresponding decrease of nonradiative decay rate constants of the excited singlet states (knr). The effect of various physicochemical environments was also studied in detail in order to understand the fluorescence behaviour of the Zn(II) complexes. FP-Zn(II) complexes have a lower solubility in water that results in the formation of molecular aggregates. The aggregation-induced loss of fluorescence of FP-Zn(II) complexes could be overcome by using the appropriate mixture of ethanol and water (70:30). Molecular orbital calculations on the FP-Zn(II) complexes provided a good idea of the geometry of the complexes and helped rationalise the enhancement of fluorescence after complexation. This study could pave the way towards developing a convenient non-extraction aqueous phase analytical procedure for detection of FPs using Zn(II) complexation method.
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stercobilin and Urobilin in aqueous media existence of specific h aggregates and nonspecific higher aggregates at different concentrations
Journal of Physical Chemistry A, 2020Co-Authors: Swayam Prakash, Ashok Kumar MishraAbstract:Fecal matter is considered to be one of the primary sources of water pollution. Understanding the aggregation behavior of the fecal pigments (FPs) could play a critical role in their detection and analysis. This work shows that in aqueous media, the fluorescence of FPs indicates the presence of multiple emitting species, which have been assigned to monomers, lower-order H-aggregates (dimers), and higher-order H-aggregates. Steady-state absorbance, fluorescence and time-resolved fluorescence decay studies conclude that the emission of FPs in aqueous medium indicates H-type of aggregation, even up to nanomolar and sub-nanomolar concentrations. Four sets of independent experiments involving the variation of (i) concentration of FPs, (ii) temperature, (iii) pH, and (iv) ethanol/water composition as solvent media suggest the presence of monomer (540 nm), dimer (516 nm), and higher-order aggregates (500 nm) of FPs in aqueous solutions. The dimeric FP species appear to be present in the entire concentration range of 1 pM to 1 μM. Fluorescence lifetimes of H-aggregates are relatively longer as compared to the corresponding monomers. Hydrogen bonding appears to play an important role in forming H-aggregates in the aqueous phase of FPs as observed in the IR spectra of the FPs in dichloromethane. Density functional theory (DFT) calculations using the B3LYP functional and the LANL2DZ basis set show the contributions of π-π stacking and hydrogen-bonding interactions toward the formation of H-aggregated dimer of FPs in aqueous media.
Paul Russo - One of the best experts on this subject based on the ideXlab platform.
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benign and tumor parenchyma metabolomic profiles affect compensatory renal growth in renal cell carcinoma surgical patients
PLOS ONE, 2017Co-Authors: Barak Rosenzweig, Nimrod D Rubinstein, Roman Shingarev, Krishna Juluru, Oguz Akin, James J Hsieh, Edgar A Jaimes, Paul Russo, Ed Reznik, Katalin SusztakAbstract:BACKGROUND AND OBJECTIVES: Pre-operative kidney volume is an independent predictor of glomerular filtration rate in renal cell carcinoma patients. Compensatory renal growth (CRG) can ensue prior to nephrectomy in parallel to tumor growth and benign parenchyma loss. We aimed to test whether renal metabolite abundances significantly associate with CRG, suggesting a causative relationship. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: Tissue metabolomics data from 49 patients, with a median age of 60 years, were previously collected and the pre-operative fold-change of their contra to ipsi-lateral benign kidney volume served as a surrogate for their CRG. Contra-lateral kidney volume fold-change within a 3.3 +/- 2.1 years follow-up interval was used as a surrogate for long-term CRG. Using a multivariable statistical model, we identified metabolites whose abundances significantly associate with CRG. RESULTS: Our analysis found 13 metabolites in the benign (e.g. L-Urobilin, Variable Influence in Projection, VIP, score = 3.02, adjusted p = 0.017) and 163 metabolites in the malignant (e.g. 3-indoxyl-sulfate, VIP score = 1.3, adjusted p = 0.044) tissues that significantly associate with CRG. Benign/tumor fold change in metabolite abundances revealed three additional metabolites with that significantly positively associate with CRG (e.g. p-cresol sulfate, VIP score = 2.945, adjusted p = 0.033). At the pathway level, we show that fatty-acid oxidation is highly enriched with metabolites whose benign tissue abundances strongly positively associate with CRG, both pre-operatively and long term, whereas in the tumor tissue significant enrichment of dipeptides and benzoate (positive association), glycolysis/gluconeogenesis, lysolipid and nucleotide sugar pentose (negative associations) sub-pathways, were observed. CONCLUSION: These data suggest that specific biological processes in the benign as well as in the tumor parenchyma strongly influence compensatory renal growth.
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effect of benign and tumor parenchyma metabolomic profiles on compensatory renal growth in renal cell carcinoma surgical patients
Journal of Clinical Oncology, 2017Co-Authors: Barak Rosenzweig, Nimrod D Rubinstein, Eduard Reznik, Piotr Zareba, Roman Shingarev, Krishna Juluru, Oguz Akin, James J Hsieh, Edgar A Jaimes, Paul RussoAbstract:446Background: Pre-operative kidney volume is an independent predictor of glomerular filtration rate in renal cell carcinoma patients. Compensatory renal growth (CRG) can ensue prior to nephrectomy in parallel to tumor growth and benign parenchyma loss. We aimed to test whether renal metabolite abundances significantly associate with CRG, suggesting a causative relationship. Methods: Tissue metabolomics data from 49 patients, with a median age of 60 years, were previously collected and the pre-operative fold-change of their contra to ipsi-lateral benign kidney volume served as a surrogate for their CRG. Contra-lateral kidney volume fold-change within a 3.3 +/- 2.1 years follow-up interval was used as a surrogate for long-term CRG. Using a multivariable statistical model we identified metabolites whose abundances significantly associate with CRG. Results: We identified 13 metabolites in the benign (e.g. L-Urobilin) and 163 metabolites in the malignant (e.g. 3-indoxyl-sulfate) tissues to significantly assoc...
Barak Rosenzweig - One of the best experts on this subject based on the ideXlab platform.
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benign and tumor parenchyma metabolomic profiles affect compensatory renal growth in renal cell carcinoma surgical patients
PLOS ONE, 2017Co-Authors: Barak Rosenzweig, Nimrod D Rubinstein, Roman Shingarev, Krishna Juluru, Oguz Akin, James J Hsieh, Edgar A Jaimes, Paul Russo, Ed Reznik, Katalin SusztakAbstract:BACKGROUND AND OBJECTIVES: Pre-operative kidney volume is an independent predictor of glomerular filtration rate in renal cell carcinoma patients. Compensatory renal growth (CRG) can ensue prior to nephrectomy in parallel to tumor growth and benign parenchyma loss. We aimed to test whether renal metabolite abundances significantly associate with CRG, suggesting a causative relationship. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: Tissue metabolomics data from 49 patients, with a median age of 60 years, were previously collected and the pre-operative fold-change of their contra to ipsi-lateral benign kidney volume served as a surrogate for their CRG. Contra-lateral kidney volume fold-change within a 3.3 +/- 2.1 years follow-up interval was used as a surrogate for long-term CRG. Using a multivariable statistical model, we identified metabolites whose abundances significantly associate with CRG. RESULTS: Our analysis found 13 metabolites in the benign (e.g. L-Urobilin, Variable Influence in Projection, VIP, score = 3.02, adjusted p = 0.017) and 163 metabolites in the malignant (e.g. 3-indoxyl-sulfate, VIP score = 1.3, adjusted p = 0.044) tissues that significantly associate with CRG. Benign/tumor fold change in metabolite abundances revealed three additional metabolites with that significantly positively associate with CRG (e.g. p-cresol sulfate, VIP score = 2.945, adjusted p = 0.033). At the pathway level, we show that fatty-acid oxidation is highly enriched with metabolites whose benign tissue abundances strongly positively associate with CRG, both pre-operatively and long term, whereas in the tumor tissue significant enrichment of dipeptides and benzoate (positive association), glycolysis/gluconeogenesis, lysolipid and nucleotide sugar pentose (negative associations) sub-pathways, were observed. CONCLUSION: These data suggest that specific biological processes in the benign as well as in the tumor parenchyma strongly influence compensatory renal growth.
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effect of benign and tumor parenchyma metabolomic profiles on compensatory renal growth in renal cell carcinoma surgical patients
Journal of Clinical Oncology, 2017Co-Authors: Barak Rosenzweig, Nimrod D Rubinstein, Eduard Reznik, Piotr Zareba, Roman Shingarev, Krishna Juluru, Oguz Akin, James J Hsieh, Edgar A Jaimes, Paul RussoAbstract:446Background: Pre-operative kidney volume is an independent predictor of glomerular filtration rate in renal cell carcinoma patients. Compensatory renal growth (CRG) can ensue prior to nephrectomy in parallel to tumor growth and benign parenchyma loss. We aimed to test whether renal metabolite abundances significantly associate with CRG, suggesting a causative relationship. Methods: Tissue metabolomics data from 49 patients, with a median age of 60 years, were previously collected and the pre-operative fold-change of their contra to ipsi-lateral benign kidney volume served as a surrogate for their CRG. Contra-lateral kidney volume fold-change within a 3.3 +/- 2.1 years follow-up interval was used as a surrogate for long-term CRG. Using a multivariable statistical model we identified metabolites whose abundances significantly associate with CRG. Results: We identified 13 metabolites in the benign (e.g. L-Urobilin) and 163 metabolites in the malignant (e.g. 3-indoxyl-sulfate) tissues to significantly assoc...
Shizuo Suzuki - One of the best experts on this subject based on the ideXlab platform.
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estimation of i Urobilin movement in an aquatic environment
Symposium on toxicology and environmental health, 1994Co-Authors: Yuichi Miyabara, Junzo Suzuki, Shizuo SuzukiAbstract:A large amount of i-Urobilin is present in the bottom sediment of urban rivers, and the value of distribution ratio (sediment/water) increase along the river, being higher at the river mouth. The adsorption equilibrium of i-Urobilin is important to estimate the movement of i-Urobilin as a fecal pollution indicator in the aquatic environment. A model adsorption experiment was carried out to determine the factors affecting the uptake of i-Urobilin by the bottom sediment. The particle size of sediment affected the adsorption of i-Urobilin. Furthermore, the content of i-Urobilin in sediment agreed with the model adsorption experiment. It was reported previously that the content of i-Urobilin and suspended solids in river water increased after rainfall. These indicated that i-Urobilin moved with suspended solids, which would precipitate at the river mouth. These results suggested that sediment samples should be collected at the mouth of the river, where i-Urobilin was concentrated.
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degradations of Urobilin and stercobilin during activated sludge treatment of night soil
Environmental Pollution, 1994Co-Authors: Yuichi Miyabara, Junzo Suzuki, Shizuo SuzukiAbstract:This paper deals with the degradation of Urobilin and stercobilin in the sewage treatment plant or domestic septic tank and elucidates the factors contributing to their decomposition. The quantities of urobolin or stercobilin in the effluents from the sewage treatment plants were low and these substances were degraded by treatment with activated sludge. The efficacies of aeration, bacterial decomposition and free chlorine treatment in degrading Urobilin or stercobilin were examined. Urobilin and stercobilin were decomposed by aeration and the decomposition rate was accelerated under alkaline conditions. Both compounds were decomposed by activated sludge, isolated bacteria and free chlorine treatments. These results show the decomposition of Urobilin and stercobilin at sewage treatment plants.
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evaluation of fecal pollution of river sediment by detection of Urobilin
Environmental Pollution, 1994Co-Authors: Yuichi Miyabara, Junzo Suzuki, Koji Miyata, Shizuo SuzukiAbstract:In this study, we attempted to establish a new indicator for fecal pollution of river sediment using a sensitive detection method for Urobilin. Urobilin contained in sediment was extracted with an alkaline buffer solution. The suitable buffer solution for extraction of Urobilin consisted of 0.1 M Tris-HCl buffer (pH 10.0) containing 0.1 m sodium chloride. The ratio of sediment to buffer was 1:10. The distribution of Urobilin in river sediment was studied by this method. The amount of Urobilin in the river sediment of Tokyo (urban) and the Miura peninsula (rural) area was surveyed. Large quantities of Urobilin were detected in the sediments of the urban rivers, but it was scarce in the rural rivers. Urobilin showed a higher content in sediment than in water. Urobilin in river sediment is distributed in large amounts in the lower reaches, where the water is polluted with domestic sewage and industrial waste, but is scarce in the upper streams. The amount of Urobilin decreases to the lower layers.
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separation and sensitive determination of i Urobilin and 1 stercobilin by high performance liquid chromatography with fluorimetric detection
Journal of Chromatography B: Biomedical Sciences and Applications, 1992Co-Authors: Yuichi Miyabara, Junzo Suzuki, Masako Tabata, Shizuo SuzukiAbstract:i-Urobilin and 1-stercobilin were separated by high-performance liquid chromatography on a reversed-phase octadecylsilane-bonded column and detected fluorimetrically through formation of phosphor with zinc ions in the eluent. The separation and the intensity of the fluorescence response were affected by concentrations of zinc acetate and sodium borate buffer, pH and methanol content in the eluent. The optimal eluent used consisted of 0.1% zinc acetate in 75 mM boric acid buffer (pH 6.0)-methanol (25:75). The detection limit was 0.2 microgram/l for both i-Urobilin and 1-stercobilin (signal-to-noise ratio 2), which makes the method 250-2500 times more sensitive than conventional methods.
