Publications by authors named "M Praveen Kumar"

7,765 Publications

Recent developments in cold plasma-based enzyme activity (browning, cell wall degradation, and antioxidant) in fruits and vegetables.

Compr Rev Food Sci Food Saf 2022 Jan 26. Epub 2022 Jan 26.

Division of Crop Physiology, Biochemistry and Post-Harvest Technology, ICAR-Central Potato Research Institute, Shimla, India.

According to the Food and Agriculture Organization of United Nations reports, approximately half of the total harvested fruits and vegetables vanish before they reach the end consumer due to their perishable nature. Enzymatic browning is one of the most common problems faced by fruit and vegetable processing. The perishability of fruits and vegetables is contributed by the various browning enzymes (polyphenol oxidase, peroxidase, and phenylalanine ammonia-lyase) and ripening or cell wall degrading enzyme (pectin methyl-esterase). In contrast, antioxidant enzymes (superoxide dismutase and catalase) assist in reversing the damage caused by reactive oxygen species or free radicals. The cold plasma technique has emerged as a novel, economic, and environmentally friendly approach that reduces the expression of ripening and browning enzymes while increasing the activity of antioxidant enzymes; microorganisms are significantly inhibited, therefore improving the shelf life of fruits and vegetables. This review narrates the mechanism and principle involved in the use of cold plasma technique as a nonthermal agent and its application in impeding the activity of browning and ripening enzymes and increasing the expression of antioxidant enzymes for improving the shelf life and quality of fresh fruits and vegetables and preventing spoilage and pathogenic germs from growing. An overview of hurdles and sustainability advantages of cold plasma technology is presented.
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http://dx.doi.org/10.1111/1541-4337.12895DOI Listing
January 2022

Heavy metal impression in surface sediments and factors governing the fate of macrobenthic communties in tropical estuarine ecosystem, India.

Environ Sci Pollut Res Int 2022 Jan 26. Epub 2022 Jan 26.

Biogeochemistry Group, National Centre for Earth Science Studies, Akkulam, Thiruvananthapuram, India.

The present study aims to investigate the contamination of heavy metals in the sediments of a tropical ecosystem, India, and to evaluate the factors responsible for the dominance of specific macrobenthic communities, particularly in estuarine sediments. For the analysis of Cu, Cr, Ni, Zn, Pb and Cd in sediments, acid digestion and subsequent quantification by microwave plasma atomic emission spectroscopy was performed, whereas for Hg determination, cold vapour atomic absorption spectrophotometry was used. The general trend of the heavy metal concentration was observed as Cr > Cu > Zn > Ni > Pb > Cd > Hg, regardless of any seasonal alteration. The estuarine region was considerably contaminated by Cu and Cr (C.F. > 2) irrespective of any seasonal difference, and by Cd in 2017 non-monsoon (CF > 3). Heavy metal contamination was most pronounced during the monsoon (2018). Estuarine and marine zone together considered as deteriorated zone especially during monsoon seasons (PLI > 1, 2018 monsoon) while riverine zone remained poorly contaminated (PLI < 1). Clay Loam/Clay/Heavy Clay textures preferred polychaetes and bivalves in the estuarine and marine zone as compared to other macrobenthic communities (OMC). Among the hydrochemical parameters, total dissolved solids in general and euryhaline and slightly alkaline pH preferred domination of bivalves followed by polychaetes in non-monsoon seasons. The trace metal contamination in estuarine sediments increases the concern of bioaccumulation tendency of dominant bivalves of the estuarine and coastal sediments.
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http://dx.doi.org/10.1007/s11356-021-18394-2DOI Listing
January 2022

Novel biologically synthesized metal nanopowder from wastewater for dye removal application.

Environ Sci Pollut Res Int 2022 Jan 26. Epub 2022 Jan 26.

Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.

A novel adsorbent based on metal sulfide nanoparticles (MeSNPs) was biologically synthesized from metallic wastewater and examined for azo dyes removal from aqueous solution in batch and continuous systems. The size of the MeSNPs was in the range of 8-10 nm, with an average specific surface area of 120.4 m/g. Batch adsorption study was then carried out using Direct Red 80 (DR 80) and Mordant Blue 9 (MB 9) as the model azo dyes by varying MeSNPs dosage, contact time, pH, and initial dye concentration. More than 99% removal efficiency of both the dyes was achieved by using MeSNPs at the following optimum conditions: 200 mg dosage, pH 2, 6 min contact time, and 100 mg L initial dye concentration. The batch sorption isotherm results were described using the Sips model, with the maximum predicted capacity values of 143.7 and 198.3 mg of dye per gram of adsorbent for DR 80 and MB 9, respectively. Besides, the sorption kinetic data for both the dyes followed the pseudo-second-order rate. Furthermore, maximum desorption efficiency values of 93% for DR 80 and 97% for MB 9 were achieved using an aqueous solution of pH 12, thus indicating that the adsorbent can be regenerated and reused further. Dynamic adsorption of the dyes was studied using a fixed-bed column with the MeSNPs as a function of liquid flow rates. The results showed an increase in breakthrough time with a decline in the flow rates for both DR 80 and MB 9 and the breakthrough behavior was explained using Thomas, Clark, and Yoon-Nelson models.
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http://dx.doi.org/10.1007/s11356-022-18723-zDOI Listing
January 2022

Efficacy and safety of avanafil as compared with sildenafil in the treatment of erectile dysfunction: A randomized, double blind, multicenter clinical trial.

Int J Urol 2022 Jan 26. Epub 2022 Jan 26.

Department of Clinical Research and Regulatory Affairs, Zydus Healthcare Limited, India.

Objective: To compare the efficacy and safety of avanafil as compared with sildenafil in the management of patients with erectile dysfunction.

Methods: It was a prospective, randomized, double-blind, two-arm, active-controlled, parallel, multicenter, non-inferiority clinical study carried out in patients with erectile dysfunction for at least 3 months and International Index of Erectile Function - Erectile Function domain score of <26 at enrolment.

Results: A total of 220 patients were randomized to receive either avanafil tablets 100 mg or sildenafil tablets 50 mg in 1:1 ratio. After 4 weeks of treatment, 40.0% of patients in the avanafil group and 45.6% of patients in the sildenafil group required dose escalation to a high dose (avanafil 200 mg/sildenafil 100 mg). The difference in the mean change of International Index of Erectile Function - Erectile Function score from baseline in the two groups increased from week 4 (1.1, 95% confidence interval -0.2 to 2.5) to week 8 (1.4, 95% confidence interval 0.1-2.7) and week 12 (2.1, 95% confidence interval 0.8-3.5), showing non-inferiority at week 4, and superiority at week 8 and week 12. Avanafil showed a faster onset of action as shown by a significantly better response to modified Sexual Encounter Profile 1 in the avanafil group (84.8%) as compared with that in the sildenafil group (28.2%; P < 0.001). Both avanafil and sildenafil were well tolerated by all the patients in the study; the most common adverse event reported during the study was headache in both the groups.

Conclusion: Avanafil is superior to sildenafil in improving the International Index of Erectile Function - Erectile Function domain score at the end of 12 weeks of treatment with the added advantage of faster onset of action.
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http://dx.doi.org/10.1111/iju.14785DOI Listing
January 2022

Breast milk contains red cell isohaemagglutinins: An observational study of 176 mothers.

Vox Sang 2022 Jan 26:e13253. Epub 2022 Jan 26.

Department of Transfusion Medicine and Immunohaematology, Christian Medical College, Vellore, India.

Background And Objectives: Maternal antibodies are transferred to the child, predominantly IgG, via the transplacental route, and mostly IgA through breast milk. Cases reported by us and others have shown the transfer of red cell allo-antibodies through breast milk. This study was conducted to assess the presence of isohaemagglutinins in breast milk, the range of titres, and the correlation between breast milk and maternal plasma titres.

Materials And Methods: A total of 176 mothers were recruited in this study. Breast milk was collected after sufficient feeding was established and within 2-5 days of delivery in a sterile container without any anticoagulant. Antibody screen, identification and titres were performed on maternal plasma as well as breast milk.

Results: Anti-A and anti-B in breast milk corresponding to their respective maternal blood groups were found in all the samples. This study has shown titres in the breast milk of anti-A and anti-B ranging from 2 to 1024 in both saline and Coombs phases. There was no association between plasma and breast milk titres, thus making it impossible to predict which mother may potentially transfer a larger amount of these haemagglutinins. Isotypes of anti-A and anti-B were evaluated in both plasma and breast milk of 11 samples, which showed predominantly IgG in 7 (63.63%) and predominantly IgA in 4 (36.36%) samples.

Conclusion: Our study demonstrates the presence of a wide range of titres for IgG antibodies of the ABO blood group system in breast milk. The clinical impact of this finding needs to be studied further, as it assumes great relevance in developing countries where anaemia continues to challenge young infants.
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http://dx.doi.org/10.1111/vox.13253DOI Listing
January 2022
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