Amyloids are highly ordered, cross-β-sheet rich protein/peptide aggregates associated with both h... more Amyloids are highly ordered, cross-β-sheet rich protein/peptide aggregates associated with both human diseases and native functions. Given the well-established ability of amyloids in interacting with cell membranes, we hypothesize that amyloids can serve as universal cell adhesive substrates. Here, we show that, similar to the extracellular matrix protein collagen, amyloids of various proteins/peptides support attachment and spreading of cells via robust stimulation of integrin expression and formation of integrin-based focal adhesions. Additionally, amyloid fibrils are also capable of immobilizing non-adherent red blood cells through charge-based interactions. Together, our results indicate that both active and passive mechanisms contribute to adhesion on amyloid fibrils. The present data may delineate the functional aspect of cell adhesion on amyloids by various organisms and its involvement in human diseases. Our results also raise the exciting possibility that cell adhesivity might be a generic property of amyloids.
[reaction: see text] A novel procedure for the preparation of 3-(4-alkoxyphenyl)-3-methylbutan-2-... more [reaction: see text] A novel procedure for the preparation of 3-(4-alkoxyphenyl)-3-methylbutan-2-one in excellent yield is described via polymer-supported AlCl3-catalyzed rearrangement of 1-(4-ethoxyphenyl)-2,2-dimehtylpropan-1-one, followed by O-alkylation under microwave irradiation condition.
American Journal of Respiratory and Critical Care Medicine, Feb 3, 2012
Since the 1989 discovery that mutations in the cystic fibrosis transmembrane conductance regulato... more Since the 1989 discovery that mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause cystic fibrosis (CF), there has been substantial progress toward understanding the molecular basis for CF lung disease, leading to the discovery and development of new therapeutic approaches. However, the earliest impact of the loss of CFTR function on airway physiology and structure and its relationship to initial infection and inflammation are poorly understood. Universal newborn screening for CF in the United States represents an unprecedented opportunity for investigating CF clinical manifestations very early in life. Recently developed animal models with pulmonary phenotypic manifestations also provide a window into the early consequences of this genetic disorder. For these reasons, the National Heart, Lung, and Blood Institute (NHLBI) convened a working group of extramural experts, entitled "Future Research Directions in Early CF Lung Disease" on September 21-22, 2010, to identify future research directions of great promise in CF. The priority areas identified included (1) exploring pathogenic mechanisms of early CF lung disease; (2) leveraging newborn screening to elucidate the natural history of early lung disease; (3) developing a spectrum of biomarkers of early lung disease that reflects CF pathophysiology, clinical outcome, and response to treatment; (4) exploring the role of genetics/genomics (e.g., modifier genes, gene-environmental interactions, and epigenetics) in early CF pathogenesis; (5) defining early microbiological events in CF lung disease; and (6) elucidating the initial airway inflammatory, remodeling, and repair mechanisms in CF lung disease.
Chemical pesticides of micronized form have been widely used for controlling pests and diseases o... more Chemical pesticides of micronized form have been widely used for controlling pests and diseases of crop plants. Recently nano formulation of these chemicals has received much attention. Synthesis of nano particles (NPs) of metallic compounds are being done by biological means using different species of bacteria (Pseudomonas, Lactobacillus, Escherichia, Thermomonospora), fungi (Aspergillus, Fusarium, Phoma, Verticillium), plants (Alfa alfa, Aloe vera, Azadirachta, Solanum, Lemon grass) and algae (Sargassum, Chlorella). They are also prepared synthetically. Silver nano particles are reported for controlling phytopathogens like Fusarium culmorum, Rafflaea sp., Rhizoctonia solani, Sclerotinia sclerotiorum, Bipolaris sorokiniana and Magnaporthe grisea. Nano copper was also effective in controlling rice bacterial blight disease caused by Xanthomonas oryzae pv. oryzae and leaf spot of mung caused by X. campestris pv. phseoli.
ABSTRACT Probabilistic forecasting of one-day maximum annual runoff is essential for safe and cos... more ABSTRACT Probabilistic forecasting of one-day maximum annual runoff is essential for safe and cost-effective planning and designing of surface runoff storage systems especially in arid and semi-arid regions of developing countries. In the present study, one-day maximum annual runoff is probabilistically forecasted at selected return periods for eight watersheds of Udaipur, Rajasthan, India. Of the eight selected watersheds in the study, seven are interconnected and one is independent. Total annual runoff from these watersheds for a period of 30 years was estimated by using Soil Conservation Service – Curve Number (SCS-CN) model. The estimated runoff is compared with the observed runoff for one independent reservoir (i.e., Bari) for validating the SCS-CN model for runoff estimation. It is found that SCS-CN model estimates runoff values well. Furthermore, seven kinds of regression models were fitted to annual rainfall and annual runoff values for individual watersheds. Based on coefficient of determination as the best-fit criteria, it is found that linear and polynomial regression models can be used for describing the relationship between annual rainfall and annual runoff for the watersheds of Udaipur. However, use of linear regression model is advantageous over the other models. Moreover, one-day and consecutive 2- and 3-day maximum annual runoff for eight individual watersheds were fitted with three selected probability distributions (i.e., log normal, log Pearson type-III, and Gumbel). The chi-squared test for goodness-of-fit was applied for selecting the best-fit distribution for consecutive days’ maximum runoff from individual watersheds. Based on the results of the Chi-square test, it was found that the best-fit distributions for describing the one-day annual maximum runoff from Bari, Chhota Madar, Lakhawali, Fatehsagar and Udaisagar watersheds is log Pearson type-III distribution. Similarly, the best-fit distribution for one-day annual maximum runoff from Pichhola, Bada Madar, and Chikalwas watersheds is Gumbel. Finally, one-day maximum annual runoff at selected return periods (i.e., 1.05, 1.11, 1.25, 2, 5, 10, 15, and 30 years) were forecasted, which are very useful for safe and economic planning and design of soil and water conservation structures in the watersheds of Udaipur.
We have designed molecules which release alcohols upon exposure to UV light independent of the re... more We have designed molecules which release alcohols upon exposure to UV light independent of the reaction media, making it possible to liberate alcohols in a controlled manner in applications. Photolysis of 2-(2-isopropylbenzoyl)benzoate ester derivatives 4 in various solvents and in thin films results in the liberation of the alcohol moiety from the ester. The reaction mechanism for the release of the alcohol has been elucidated by time-resolved laser flash photolysis. Upon irradiation the triplet excited state of ketone, 4 is formed, and its lifetime can be estimated to be between 0.08 and 0.8 ns. The triplet excited state decays by efficient intramolecular H-atom abstraction to form a 1,4-biradical, 8, that has a lifetime of less than 17 ns and is trapped by molecular oxygen. In the absence of oxygen, biradical 8 intersystem crosses to form photoenols (Z)-9 and (E)-10 in a ratio of 5:2, respectively. Photoenol (Z)-9 has a lifetime of ∼3000 ns in protic solvents and returns to the starting material through 1,5 intramolecular hydrogen transfer. The other isomer, (E)-10, is much longer lived (>1 ms) and releases the alcohol moiety through an intramolecular lactonization.
International Journal of Advanced Remote Sensing and Gis, Oct 31, 2013
Impact of population explosion is clear on urban landscape of not only metropolitan cities but al... more Impact of population explosion is clear on urban landscape of not only metropolitan cities but also on small and medium towns of India. Dehradun, the interim capital of Uttrakhand state, India also witnessed tremendous developments over last two decades. It alters the landscape pattern of the city. In this study, changes in the landscape pattern of Dehradun city and surroundings has been explored using Landsat TM image of 1986 and IRS-1C/1D LISS III image of 1998 and 2011. For this purpose, the calculation of the metrics i.e., percentage of landscape (PLAND), number of patch (NP), mean patch size (MPS) have been carried out with public domain software-Fragstatsver 4.
Expression of the Pseudomonas aeruginosa type III secretion system is induced by contact with euk... more Expression of the Pseudomonas aeruginosa type III secretion system is induced by contact with eukaryotic cells, serum or low Ca2+ concentrations. We report that ExsD, a unique protein, is a negative regulator of the type III regulon. Localization studies indicate that ExsD is not secreted by P. aeruginosa. To determine the role of exsD, a non-polar deletion was returned to the chromosome by allelic exchange. The delta exsD mutant is competent for type III secretion and translocation of the ExoU cytotoxin to eukaryotic host cells. To examine the effect of ExsD on transcription, lacZ transcriptional reporter fusions were integrated into the chromosome. Promoters controlling transcription of genes encoding the type III secretory, regulatory and effector proteins demonstrated significant derepression in the delta exsD background. Expression of ExsD from a multicopy plasmid completely repressed transcription of the regulon. Although a mutant in pscC, encoding a structural component of the type III translocase, is repressed for expression of the regulon, a delta exsD, pscC:: omega double mutant is derepressed. Bacterial two-hybrid data indicate that ExsD binds the transcriptional activator of the regulon, ExsA. We conclude that ExsD is a negative regulator and propose that ExsD functions as an ExsA antiactivator to regulate transcription of the regulon.
Cu(II) complexes of acenaphthaquinonemono(4-methylquinolinyl)hydrazone (AMH) of general compositi... more Cu(II) complexes of acenaphthaquinonemono(4-methylquinolinyl)hydrazone (AMH) of general composition [CuLX2] (where L =AMH; X =CI, Br, I, OAc or NO3) with the exception of sulphato complex, where the composition is found to be [CuLSO4]2 have been synthesized and characterized by elemental analyses, magnetic moment measurements, conductivity measurements, IR, electronic and EPR spectral techniques and by thermal analysis. A planar geometry is indicated for all the complexes. TG curves show one step decomposition of complexes and formation of Cu20 at the end of the step.
Geocarto International, Vol. 15, No. 4, December 2000 Published by Geocarto International Centre,... more Geocarto International, Vol. 15, No. 4, December 2000 Published by Geocarto International Centre, GPO Box 4122, Hong Kong. ... Integrated GIS and Remote Sensing Approach to Map Pollution ... Nitin Kumar Tripathi Space Technology Application and Research Program, ...
Preparation of G-rich TFOs containing cholesterol at the end presents challenging problems due to... more Preparation of G-rich TFOs containing cholesterol at the end presents challenging problems due to low yield in synthesis and loss in purification due to aggregation. These compounds also have low solubility which can result in variability in their uptake properties and cellular efficacy. To overcome these problems we have designed and synthesized cholesteryl -CPG (6) and -TentaGel (7) supports and phosphoramidite (8) containing a triglycyl linker.
Amyloids are highly ordered, cross-β-sheet rich protein/peptide aggregates associated with both h... more Amyloids are highly ordered, cross-β-sheet rich protein/peptide aggregates associated with both human diseases and native functions. Given the well-established ability of amyloids in interacting with cell membranes, we hypothesize that amyloids can serve as universal cell adhesive substrates. Here, we show that, similar to the extracellular matrix protein collagen, amyloids of various proteins/peptides support attachment and spreading of cells via robust stimulation of integrin expression and formation of integrin-based focal adhesions. Additionally, amyloid fibrils are also capable of immobilizing non-adherent red blood cells through charge-based interactions. Together, our results indicate that both active and passive mechanisms contribute to adhesion on amyloid fibrils. The present data may delineate the functional aspect of cell adhesion on amyloids by various organisms and its involvement in human diseases. Our results also raise the exciting possibility that cell adhesivity might be a generic property of amyloids.
[reaction: see text] A novel procedure for the preparation of 3-(4-alkoxyphenyl)-3-methylbutan-2-... more [reaction: see text] A novel procedure for the preparation of 3-(4-alkoxyphenyl)-3-methylbutan-2-one in excellent yield is described via polymer-supported AlCl3-catalyzed rearrangement of 1-(4-ethoxyphenyl)-2,2-dimehtylpropan-1-one, followed by O-alkylation under microwave irradiation condition.
American Journal of Respiratory and Critical Care Medicine, Feb 3, 2012
Since the 1989 discovery that mutations in the cystic fibrosis transmembrane conductance regulato... more Since the 1989 discovery that mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause cystic fibrosis (CF), there has been substantial progress toward understanding the molecular basis for CF lung disease, leading to the discovery and development of new therapeutic approaches. However, the earliest impact of the loss of CFTR function on airway physiology and structure and its relationship to initial infection and inflammation are poorly understood. Universal newborn screening for CF in the United States represents an unprecedented opportunity for investigating CF clinical manifestations very early in life. Recently developed animal models with pulmonary phenotypic manifestations also provide a window into the early consequences of this genetic disorder. For these reasons, the National Heart, Lung, and Blood Institute (NHLBI) convened a working group of extramural experts, entitled "Future Research Directions in Early CF Lung Disease" on September 21-22, 2010, to identify future research directions of great promise in CF. The priority areas identified included (1) exploring pathogenic mechanisms of early CF lung disease; (2) leveraging newborn screening to elucidate the natural history of early lung disease; (3) developing a spectrum of biomarkers of early lung disease that reflects CF pathophysiology, clinical outcome, and response to treatment; (4) exploring the role of genetics/genomics (e.g., modifier genes, gene-environmental interactions, and epigenetics) in early CF pathogenesis; (5) defining early microbiological events in CF lung disease; and (6) elucidating the initial airway inflammatory, remodeling, and repair mechanisms in CF lung disease.
Chemical pesticides of micronized form have been widely used for controlling pests and diseases o... more Chemical pesticides of micronized form have been widely used for controlling pests and diseases of crop plants. Recently nano formulation of these chemicals has received much attention. Synthesis of nano particles (NPs) of metallic compounds are being done by biological means using different species of bacteria (Pseudomonas, Lactobacillus, Escherichia, Thermomonospora), fungi (Aspergillus, Fusarium, Phoma, Verticillium), plants (Alfa alfa, Aloe vera, Azadirachta, Solanum, Lemon grass) and algae (Sargassum, Chlorella). They are also prepared synthetically. Silver nano particles are reported for controlling phytopathogens like Fusarium culmorum, Rafflaea sp., Rhizoctonia solani, Sclerotinia sclerotiorum, Bipolaris sorokiniana and Magnaporthe grisea. Nano copper was also effective in controlling rice bacterial blight disease caused by Xanthomonas oryzae pv. oryzae and leaf spot of mung caused by X. campestris pv. phseoli.
ABSTRACT Probabilistic forecasting of one-day maximum annual runoff is essential for safe and cos... more ABSTRACT Probabilistic forecasting of one-day maximum annual runoff is essential for safe and cost-effective planning and designing of surface runoff storage systems especially in arid and semi-arid regions of developing countries. In the present study, one-day maximum annual runoff is probabilistically forecasted at selected return periods for eight watersheds of Udaipur, Rajasthan, India. Of the eight selected watersheds in the study, seven are interconnected and one is independent. Total annual runoff from these watersheds for a period of 30 years was estimated by using Soil Conservation Service – Curve Number (SCS-CN) model. The estimated runoff is compared with the observed runoff for one independent reservoir (i.e., Bari) for validating the SCS-CN model for runoff estimation. It is found that SCS-CN model estimates runoff values well. Furthermore, seven kinds of regression models were fitted to annual rainfall and annual runoff values for individual watersheds. Based on coefficient of determination as the best-fit criteria, it is found that linear and polynomial regression models can be used for describing the relationship between annual rainfall and annual runoff for the watersheds of Udaipur. However, use of linear regression model is advantageous over the other models. Moreover, one-day and consecutive 2- and 3-day maximum annual runoff for eight individual watersheds were fitted with three selected probability distributions (i.e., log normal, log Pearson type-III, and Gumbel). The chi-squared test for goodness-of-fit was applied for selecting the best-fit distribution for consecutive days’ maximum runoff from individual watersheds. Based on the results of the Chi-square test, it was found that the best-fit distributions for describing the one-day annual maximum runoff from Bari, Chhota Madar, Lakhawali, Fatehsagar and Udaisagar watersheds is log Pearson type-III distribution. Similarly, the best-fit distribution for one-day annual maximum runoff from Pichhola, Bada Madar, and Chikalwas watersheds is Gumbel. Finally, one-day maximum annual runoff at selected return periods (i.e., 1.05, 1.11, 1.25, 2, 5, 10, 15, and 30 years) were forecasted, which are very useful for safe and economic planning and design of soil and water conservation structures in the watersheds of Udaipur.
We have designed molecules which release alcohols upon exposure to UV light independent of the re... more We have designed molecules which release alcohols upon exposure to UV light independent of the reaction media, making it possible to liberate alcohols in a controlled manner in applications. Photolysis of 2-(2-isopropylbenzoyl)benzoate ester derivatives 4 in various solvents and in thin films results in the liberation of the alcohol moiety from the ester. The reaction mechanism for the release of the alcohol has been elucidated by time-resolved laser flash photolysis. Upon irradiation the triplet excited state of ketone, 4 is formed, and its lifetime can be estimated to be between 0.08 and 0.8 ns. The triplet excited state decays by efficient intramolecular H-atom abstraction to form a 1,4-biradical, 8, that has a lifetime of less than 17 ns and is trapped by molecular oxygen. In the absence of oxygen, biradical 8 intersystem crosses to form photoenols (Z)-9 and (E)-10 in a ratio of 5:2, respectively. Photoenol (Z)-9 has a lifetime of ∼3000 ns in protic solvents and returns to the starting material through 1,5 intramolecular hydrogen transfer. The other isomer, (E)-10, is much longer lived (>1 ms) and releases the alcohol moiety through an intramolecular lactonization.
International Journal of Advanced Remote Sensing and Gis, Oct 31, 2013
Impact of population explosion is clear on urban landscape of not only metropolitan cities but al... more Impact of population explosion is clear on urban landscape of not only metropolitan cities but also on small and medium towns of India. Dehradun, the interim capital of Uttrakhand state, India also witnessed tremendous developments over last two decades. It alters the landscape pattern of the city. In this study, changes in the landscape pattern of Dehradun city and surroundings has been explored using Landsat TM image of 1986 and IRS-1C/1D LISS III image of 1998 and 2011. For this purpose, the calculation of the metrics i.e., percentage of landscape (PLAND), number of patch (NP), mean patch size (MPS) have been carried out with public domain software-Fragstatsver 4.
Expression of the Pseudomonas aeruginosa type III secretion system is induced by contact with euk... more Expression of the Pseudomonas aeruginosa type III secretion system is induced by contact with eukaryotic cells, serum or low Ca2+ concentrations. We report that ExsD, a unique protein, is a negative regulator of the type III regulon. Localization studies indicate that ExsD is not secreted by P. aeruginosa. To determine the role of exsD, a non-polar deletion was returned to the chromosome by allelic exchange. The delta exsD mutant is competent for type III secretion and translocation of the ExoU cytotoxin to eukaryotic host cells. To examine the effect of ExsD on transcription, lacZ transcriptional reporter fusions were integrated into the chromosome. Promoters controlling transcription of genes encoding the type III secretory, regulatory and effector proteins demonstrated significant derepression in the delta exsD background. Expression of ExsD from a multicopy plasmid completely repressed transcription of the regulon. Although a mutant in pscC, encoding a structural component of the type III translocase, is repressed for expression of the regulon, a delta exsD, pscC:: omega double mutant is derepressed. Bacterial two-hybrid data indicate that ExsD binds the transcriptional activator of the regulon, ExsA. We conclude that ExsD is a negative regulator and propose that ExsD functions as an ExsA antiactivator to regulate transcription of the regulon.
Cu(II) complexes of acenaphthaquinonemono(4-methylquinolinyl)hydrazone (AMH) of general compositi... more Cu(II) complexes of acenaphthaquinonemono(4-methylquinolinyl)hydrazone (AMH) of general composition [CuLX2] (where L =AMH; X =CI, Br, I, OAc or NO3) with the exception of sulphato complex, where the composition is found to be [CuLSO4]2 have been synthesized and characterized by elemental analyses, magnetic moment measurements, conductivity measurements, IR, electronic and EPR spectral techniques and by thermal analysis. A planar geometry is indicated for all the complexes. TG curves show one step decomposition of complexes and formation of Cu20 at the end of the step.
Geocarto International, Vol. 15, No. 4, December 2000 Published by Geocarto International Centre,... more Geocarto International, Vol. 15, No. 4, December 2000 Published by Geocarto International Centre, GPO Box 4122, Hong Kong. ... Integrated GIS and Remote Sensing Approach to Map Pollution ... Nitin Kumar Tripathi Space Technology Application and Research Program, ...
Preparation of G-rich TFOs containing cholesterol at the end presents challenging problems due to... more Preparation of G-rich TFOs containing cholesterol at the end presents challenging problems due to low yield in synthesis and loss in purification due to aggregation. These compounds also have low solubility which can result in variability in their uptake properties and cellular efficacy. To overcome these problems we have designed and synthesized cholesteryl -CPG (6) and -TentaGel (7) supports and phosphoramidite (8) containing a triglycyl linker.
Uploads
Papers by Pradeep Singh