15 research outputs found

    How the Atmosphere over Eastern Himalaya, India is Polluted with Carbonyl Compounds? Temporal Variability and Identification of Sources

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    A study was conducted on atmospheric carbonyl compounds for the first time over a Himalayan atmosphere in India. Samples were collected from a high altitude hill station, Darjeeling (27.01°N, 88.15°E, 2200 masl) during June 2012 to May 2013. Temporal variation, meteorological influence, source apportionment and ozone formation potential etc were studied for acetaldehyde, formaldehyde, acetone, butanaldehyde, propanaldehyde, benzaldehyde, crotonaldehyde, valeraldehyde, isovaleraldehyde, hexanaldehyde, p-tolualdehyde and o-tolualdehyde. High concentration of Acetone (81.6 ± 63.5 ”g m–3) was observed which could be due to the higher photochemical production from its precursor volatile organic compounds emitted from tea plants and tea processing units. The concentration of acetaldehyde (20.7 ± 47.6 ”g m–3) and formaldehyde (11.6 ± 16.3 ”g m–3) were found to be comparable with metro cities of India and world. The average annual concentration of total carbonyl compounds was 174.2 ± 184.6 ”g m–3 with maximum during postmonsoon (456.9 ± 199.5 ”g m–3) and minimum during winter season (72.2 ± 42.9 ”g m–3). Meteorological parameters like temperature and surface reaching solar radiative flux played the major roles for the seasonal variation of the carbonyl concentration over the hill station. The average ratio of formaldehyde to acetaldehyde over Darjeeling was found to be 1.64 ± 1.43 well representing a typical urban atmosphere at this part of Himalaya. Positive matrix factorization model showed that the biogenic emissions from tea plants and vehicular emissions were the major sources of carbonyl compounds over the hill station

    Tribological Performance Analysis of Electroless Nickel Coated Mild Steel: A Comparative Experimental Study

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    In the pursuit of sustainable materials, electroless Nickel coating has emerged as a breakthrough in the development of novel materials with excellent tribological properties. In the present work, NiP and NiB coating has been performed over mild steel specimens for an hour. The tribological character for various loads of NiP and NiB-coated mild steel was determined through tribological tests. The wear behavior of both NiP and NiB-coated mild steel has been analyzed. The NiB-coated mild steel was found to show less coefficient of friction and wear rate than NiP-coated mild steel

    Tripodal molecular propellers perturb microtubule dynamics: indole acts as a blade and plays a crucial role in anticancer activity

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    An indole-rich tripodal microtubule inhibitor is designed, which binds at the DCVJ site of tubulin and inhibits its polymerization. It causes apoptotic death of cancer cells without affecting normal cells and inhibits the growth of tumors. Finally, STD-NMR and TR-NOESY experiments reveal that the indole appendages play a crucial role in interacting with tubulin

    Generalization of Runoff Risk Prediction at Field Scales to a Continental- Scale Region Using Cluster Analysis and Hybrid Modeling

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    As surface water resources in the U.S. continue to be pressured by excess nutrients carried by agricultural runoff, the need to assess runoff risk at the field scale continues to grow in importance. Most landscape hydrologic models developed at regional scales have limited applicability at finer spatial scales. Hybrid models can be used to address the scale mismatch between model simulation and applicability, but could be limited by their ability to generalize over a large domain with heterogeneous hydrologic characteristics. To assist the generalization, we develop a regionalization approach based on the principal component analysis and K- means clustering to identify the clusters with similar runoff potential over the Great Lakes region. For each cluster, hybrid models are developed by combining National Oceanic and Atmospheric Administration’s National Water Model and a data- driven model, eXtreme gradient boosting with field- scale measurements, enabling prediction of daily runoff risk level at the field scale over the entire region.Plain Language SummaryNutrient loading is an important factor determining water quality in the Great Lakes. Transport of nutrients to surface water is often correlated with runoff, causing detrimental effects to aquatic ecosystems, such as harmful algal blooms. Runoff risk forecasts constituting an early warning system can be used to improve timing of nutrient application, leading to dual benefits of reducing nutrient transport to surface water and leaving more nutrients in the field for crop growth. However, measurements of the edge- of- field runoff are conducted at the field scale and sparse over the Great Lakes region, posing a great challenge to developing such a warning system over the continental scale. To address the challenge, we developed a generalization approach that allows predictive models developed using the runoff measurements at the field scale to be generalized to large regions with similar hydrogeologic characteristics. We can then predict the daily runoff risk level over the entire Great Lakes domain at 1 km- by- 1 km resolution, which shows promise to be the backbone of the early warning system on the forecast of daily risk level for the Contiguous U.S.Key PointsIdentify five clusters in the Great Lakes region with similar runoff potentialGeneralize hybrid models developed at field scales to a continental- scale regionPredict daily runoff risk on 1 km- by- 1 km grid over the entire Great Lakes regionPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/174817/1/grl64743.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/174817/2/2022GL100667-sup-0001-Supporting_Information_SI-S01.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/174817/3/grl64743_am.pd

    Phenolic Phytochemicals for Prevention and Treatment of Colorectal Cancer: A Critical Evaluation of In Vivo Studies

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    Colorectal cancer (CRC) is the third most diagnosed and second leading cause of cancer-related death worldwide. Limitations with existing treatment regimens have demanded the search for better treatment options. Different phytochemicals with promising anti-CRC activities have been reported, with the molecular mechanism of actions still emerging. This review aims to summarize recent progress on the study of natural phenolic compounds in ameliorating CRC using in vivo models. This review followed the guidelines of the Preferred Reporting Items for Systematic Reporting and Meta-Analysis. Information on the relevant topic was gathered by searching the PubMed, Scopus, ScienceDirect, and Web of Science databases using keywords, such as “colorectal cancer” AND “phenolic compounds”, “colorectal cancer” AND “polyphenol”, “colorectal cancer” AND “phenolic acids”, “colorectal cancer” AND “flavonoids”, “colorectal cancer” AND “stilbene”, and “colorectal cancer” AND “lignan” from the reputed peer-reviewed journals published over the last 20 years. Publications that incorporated in vivo experimental designs and produced statistically significant results were considered for this review. Many of these polyphenols demonstrate anti-CRC activities by inhibiting key cellular factors. This inhibition has been demonstrated by antiapoptotic effects, antiproliferative effects, or by upregulating factors responsible for cell cycle arrest or cell death in various in vivo CRC models. Numerous studies from independent laboratories have highlighted different plant phenolic compounds for their anti-CRC activities. While promising anti-CRC activity in many of these agents has created interest in this area, in-depth mechanistic and well-designed clinical studies are needed to support the therapeutic use of these compounds for the prevention and treatment of CRC

    Phenolic Phytochemicals for Prevention and Treatment of Colorectal Cancer: A Critical Evaluation of In Vivo Studies

    No full text
    Colorectal cancer (CRC) is the third most diagnosed and second leading cause of cancer-related death worldwide. Limitations with existing treatment regimens have demanded the search for better treatment options. Different phytochemicals with promising anti-CRC activities have been reported, with the molecular mechanism of actions still emerging. This review aims to summarize recent progress on the study of natural phenolic compounds in ameliorating CRC using in vivo models. This review followed the guidelines of the Preferred Reporting Items for Systematic Reporting and Meta-Analysis. Information on the relevant topic was gathered by searching the PubMed, Scopus, ScienceDirect, and Web of Science databases using keywords, such as “colorectal cancer” AND “phenolic compounds”, “colorectal cancer” AND “polyphenol”, “colorectal cancer” AND “phenolic acids”, “colorectal cancer” AND “flavonoids”, “colorectal cancer” AND “stilbene”, and “colorectal cancer” AND “lignan” from the reputed peer-reviewed journals published over the last 20 years. Publications that incorporated in vivo experimental designs and produced statistically significant results were considered for this review. Many of these polyphenols demonstrate anti-CRC activities by inhibiting key cellular factors. This inhibition has been demonstrated by antiapoptotic effects, antiproliferative effects, or by upregulating factors responsible for cell cycle arrest or cell death in various in vivo CRC models. Numerous studies from independent laboratories have highlighted different plant phenolic compounds for their anti-CRC activities. While promising anti-CRC activity in many of these agents has created interest in this area, in-depth mechanistic and well-designed clinical studies are needed to support the therapeutic use of these compounds for the prevention and treatment of CRC
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