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Fulltext Biopolymers Regulate Silver Nanoparticle under Microwave Irradiation for Effective Antibacterial and Antibiofilm Activities

Velusamy P, Su CH, Venkat Kumar G, Adhikary S, Pandian K, Gopinath SC, et al.

PLoS One, 2016;11(6):e0157612.
PMID: 27304672 DOI: 10.1371/journal.pone.0157612

In the current study, facile synthesis of carboxymethyl cellulose (CMC) and sodium alginate capped silver nanoparticles (AgNPs) was examined using microwave radiation and aniline as a reducing agent. The biopolymer matrix embedded nanoparticles were synthesized under various experimental conditions using different concentrations of biopolymer (0.5, 1, 1.5, 2%), volumes of reducing agent (50, 100, 150 μL), and duration of heat treatment (30 s to 240 s). The synthesized nanoparticles were analyzed by scanning electron microscopy, UV-Vis spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy for identification of AgNPs synthesis, crystal nature, shape, size, and type of capping action. In addition, the significant antibacterial efficacy and antibiofilm activity of biopolymer capped AgNPs were demonstrated against different bacterial strains, Staphylococcus aureus MTCC 740 and Escherichia coli MTCC 9492. These results confirmed the potential for production of biopolymer capped AgNPs grown under microwave irradiation, which can be used for industrial and biomedical applications.
Phase transition kinetics and surface binding states of methylammonium lead iodide perovskite

Rajendra Kumar G, Dennyson Savariraj A, Karthick SN, Selvam S, Balamuralitharan B, Kim HJ, et al.

Phys Chem Chem Phys, 2016 Mar 2;18(10):7284-92.
PMID: 26894928 DOI: 10.1039/c5cp06232b

We have presented a detailed analysis of the phase transition kinetics and binding energy states of solution processed methylammonium lead iodide (MAPbI3) thin films prepared at ambient conditions and annealed at different elevated temperatures. It is the processing temperature and environmental conditions that predominantly control the crystal structure and surface morphology of MAPbI3 thin films. The structural transformation from tetragonal to cubic occurs at 60 °C with a 30 minute annealing time while the 10 minute annealed films posses a tetragonal crystal structure. The transformed phase is greatly intact even at the higher annealing temperature of 150 °C and after a time of 2 hours. The charge transfer interaction between the Pb 4f and I 3d oxidation states is quantified using XPS.
Malignant transformation of mesenchymal hamartoma of the liver: case report and review of the literature

Ramanujam TM, Ramesh JC, Goh DW, Wong KT, Ariffin WA, Kumar G, et al.

J Pediatr Surg, 1999 Nov;34(11):1684-6.
PMID: 10591570

Here the first case in the literature of both mesenchymal hamartoma and malignant mesenchymoma occurring in a 6-year-old male child, at different times and at different sites in the liver, and also the possible malignant transformation of a mesenchymal hamartoma is reported. The tumor developed from a lesion in the right lobe that was overlooked initially during a left lateral segmentectomy at 18 months of age for a mesenchymal hamartoma. Malignant mesenchymoma is a rare and aggressive tumor. The origin of this tumor is not well understood. There has been no direct support to the hypothesis that malignant mesenchymoma may be the malignant counterpart of mesenchymal hamartoma. The authors provide clinical and histopathologic evidence in our case that suggests the possibility of malignant mesenchymoma arising from a mesenchymal hamartoma. This case emphasizes the need for complete removal of mesenchymal hamartoma and the need for long-term follow-up to detect multifocal lesion or malignant transformation.
Blastocystis in animal handlers

Rajah Salim H, Suresh Kumar G, Vellayan S, Mak JW, Khairul Anuar A, Init I, et al.

Parasitol Res, 1999 Dec;85(12):1032-3.
PMID: 10599928

The present study investigated whether people working closely with animals were at higher risk of getting infected with Blastocystis hominis. The prevalence of the parasite was determined in two population groups, i.e., animal handlers and normal healthy individuals who did not work with animals. In all, 105 stool samples were collected from animal handlers from 2 local research institutions, a local zoo, and a local abattoir and 163 stool samples were collected from normal healthy individuals residing in high-rise flats in the city. The in vitro culture method used in the study detected that 41% of 105 animal handlers and 17% of 163 flat-dwellers in the city were positive for Blastocystis. This statistically significant finding (P = 0.0000313) shows that people who work closely with animals do stand at risk of acquiring Blastocystis infection.
Fulltext Use of 100 kV versus 120 kV in computed tomography pulmonary angiography in the detection of pulmonary embolism: effect on radiation dose and image quality

Gill MK, Vijayananthan A, Kumar G, Jayarani K, Ng KH, Sun Z

Quant Imaging Med Surg, 2015 Aug;5(4):524-33.
PMID: 26435916 DOI: 10.3978/j.issn.2223-4292.2015.04.04

To determine the effective radiation dose and image quality resulting from 100 versus 120 kilovoltage (kV) protocols among patients referred for computed tomography pulmonary angiography (CTPA).
Fulltext An efficient approach for the synthesis of novel methyl sulfones in acetic acid medium and evaluation of antimicrobial activity

Ravi Kumar G, Dasireddy CR, Varala R, Kotra V, Bollikolla HB

Turk J Chem, 2020;44(5):1386-1394.
PMID: 33488238 DOI: 10.3906/kim-2003-10

A series of nine methyl sulphones ( 3a -3 i ) starting from the aldehydes ( 1a-1i ) were synthesized in two consecutive steps. In the first step, preparation of allyl alcohols ( 2a-2i ) from their corresponding aldehydes by the reaction of sodium borohydride in methanol at room temperature is reported. Finally, methyl sulphones are synthesized by condensing sodium methyl sulfinates with allyl alcohols in the presence of BF 3 .Et 2 O in acetic acid medium at room temperature for about 2-3 h. The reaction conditions are simple, yields are high (85%-95%), and the products were obtained with good purity. All the synthesized compounds were characterized by their 1 H, 13 C NMR, and mass spectral analysis. All the title compounds were screened for antimicrobial activity. Among the compounds tested, the compound 3f has inhibited both Gram positive and Gram negative bacteria effectively and compound 3i has shown potent antifungal activity. These promising components may help to develop more potent drugs in the near future for the treatment of bacterial and fungal infections.
A review on bio-electrochemical systems (BESs) for the syngas and value added biochemicals production

Kumar G, Saratale RG, Kadier A, Sivagurunathan P, Zhen G, Kim SH, et al.

Chemosphere, 2017 Jun;177:84-92.
PMID: 28284119 DOI: 10.1016/j.chemosphere.2017.02.135

Bio-electrochemical systems (BESs) are the microbial systems which are employed to produce electricity directly from organic wastes along with some valuable chemicals production such as medium chain fatty acids; acetate, butyrate and alcohols. In this review, recent updates about value-added chemicals production concomitantly with the production of gaseous fuels like hydrogen and methane which are considered as cleaner for the environment have been addressed. Additionally, the bottlenecks associated with the conversion rates, lower yields and other aspects have been mentioned. In spite of its infant stage development, this would be the future trend of energy, biochemicals and electricity production in greener and cleaner pathway with the win-win situation of organic waste remediation. Henceforth, this review intends to summarise and foster the progress made in the BESs and discusses its challenges and outlook on future research advances.
Microbiome involved in microbial electrochemical systems (MESs): A review

Saratale RG, Saratale GD, Pugazhendhi A, Zhen G, Kumar G, Kadier A, et al.

Chemosphere, 2017 Mar 09;177:176-188.
PMID: 28288426 DOI: 10.1016/j.chemosphere.2017.02.143

Microbial electrochemical systems (MESs) are an attracting technology for the disposal of wastewater treatment and simultaneous energy production. In MESs, at the anode microorganisms through the catalytic activity generates electrons that can be converted into electricity or other valuable chemical compounds. Microorganisms those having ability to donate and accept electrons to and from anode and cathode electrodes, respectively are recognized as 'exoelectrogens'. In the MESs, it renders an important function for its performance. In the present mini-review, we have discussed the role of microbiome including pure culture, enriched culture and mixed culture in different BESs application. The effects of operational and biological factors on microbiome development have been discussed. Further discussion about the molecular techniques for the evaluation of microbial community analysis is addressed. In addition different electrochemical techniques for extracellular electron transfer (EET) mechanism of electroactive biofilms have been discussed. This review highlights the importance of microbiome in the development of MESs, effective operational factors for exo-electrogens activities as well their key challenges and future technological aspects are also briefly discussed.
Risk Factors and Treatment Needs among Orphan School Children

Shanthi M, Goud EVSS, Kumar GP, Rajguru JP, Ratnasothy S, Ealla KK

J Contemp Dent Pract, 2017 Oct 01;18(10):893-898.
PMID: 28989126

AIM: The aim of the study was to identify risk factors and treatment needs of orphan children of Selangor, Kuala Lumpur, Malaysia. Ob ectives: (1) To identify the association between the frequency of snacking and caries among orphan schoolchildren, (2) To assess Streptococcus mutans and Lactobacilli (microbiological assessment) in saliva of orphan children, and (3) To formulate treatment needs for orphan children.
MATERIALS AND METHODS: A cross-sectional study was done among 253 children of 5-, 12-, and 15-year-olds living in various orphanage houses of Selangor, Kuala Lumpur, Malaysia. Demographic data, and dietary and oral hygiene practices were collected through a structured questionnaire. Clinical examinations of children were conducted to assess oral health status and recorded in the World Health Organization oral health assessment form (1997). Stimulated saliva was collected for S. mutans and Lactobacilli levels. The statistical software, namely, Statistical Package for the Social Sciences version 19.0 was used for the analysis of the data.
RESULTS: The final data analysis included 253 children of which 116 (45.8%) were boys and 137 (54.2%) were girls. Overall, 140 (55.33%) children were caries-free and 113 (44.66%) children presented with caries (decayed/missing/filled surface >0). High levels of salivary microbiological counts (S. mutans and Lactobacilli), i.e., ≥105, stress the importance of necessary preventive oral health services. Treatment needs among orphan children showed that most of the children, i.e., 58 (22.9%), need preventive or caries-arresting care followed by 49 (19.4%) who require two-surface filling as an immediate measure.
CONCLUSION: From the results of our study, orphan children have low utilization of preventive and therapeutic oral health services. Urgent attention is required to plan a comprehensive dental health-care program to improve their oral health status.
CLINICAL SIGNIFICANCE: Parents are the primary caretakers of children, but woefully some of them have to lead their lives without parents, the latter either being dead or incapable of bringing up their children. Such a group of children is known as orphans. As oral health is an integral part of general health, it is essential for health-care policy makers to address oral health needs of this underprivileged group of society. This article highlights the risk factors and treatment needs among orphan schoolchildren.
A comprehensive review on two-stage integrative schemes for the valorization of dark fermentative effluents

Sivagurunathan P, Kuppam C, Mudhoo A, Saratale GD, Kadier A, Zhen G, et al.

Crit Rev Biotechnol, 2018 Sep;38(6):868-882.
PMID: 29264932 DOI: 10.1080/07388551.2017.1416578

This review provides the alternative routes towards the valorization of dark H2 fermentation effluents that are mainly rich in volatile fatty acids such as acetate and butyrate. Various enhancement and alternative routes such as photo fermentation, anaerobic digestion, utilization of microbial electrochemical systems, and algal system towards the generation of bioenergy and electricity and also for efficient organic matter utilization are highlighted. What is more, various integration schemes and two-stage fermentation for the possible scale up are reviewed. Moreover, recent progress for enhanced performance towards waste stabilization and overall utilization of useful and higher COD present in the organic source into value-added products are extensively discussed.
Predictions of biochar production and torrefaction performance from sugarcane bagasse using interpolation and regression analysis

Chen WH, Hsu HJ, Kumar G, Budzianowski WM, Ong HC

Bioresour Technol, 2017 Dec;246:12-19.
PMID: 28803060 DOI: 10.1016/j.biortech.2017.07.184

This study focuses on the biochar formation and torrefaction performance of sugarcane bagasse, and they are predicted using the bilinear interpolation (BLI), inverse distance weighting (IDW) interpolation, and regression analysis. It is found that the biomass torrefied at 275°C for 60min or at 300°C for 30min or longer is appropriate to produce biochar as alternative fuel to coal with low carbon footprint, but the energy yield from the torrefaction at 300°C is too low. From the biochar yield, enhancement factor of HHV, and energy yield, the results suggest that the three methods are all feasible for predicting the performance, especially for the enhancement factor. The power parameter of unity in the IDW method provides the best predictions and the error is below 5%. The second order in regression analysis gives a more reasonable approach than the first order, and is recommended for the predictions.
Fulltext Novel same-metal three electrode system for cyclic voltammetry studies

Periasamy V, Elumalai PNN, Talebi S, Subramaniam RT, Kasi R, Iwamoto M, et al.

RSC Adv, 2023 Feb 14;13(9):5744-5752.
PMID: 36816072 DOI: 10.1039/d3ra00457k

Conventional three-electrode systems used in electrochemical measurement demand time-consuming and maintenance intensive procedures to enable accurate and repeatable electrochemical measurements. Traditionally, different metal configurations are used to establish the electrochemical gradient required to acquire the redox activity, and vary between different electrochemical measurement platforms. However, in this work, we report using the same metal (gold) for the counter, working and reference electrodes fabricated on a miniaturized printed circuit board (PCB) for a much simpler design. Potassium ferricyanide, widely used as a redox probe for electrochemical characterization, was utilized to acquire cyclic voltametric profiles using both the printed circuit board-based gold-gold-gold three-electrode and conventional three-electrode systems (glassy carbon electrode or graphite foil as the working electrode, platinum wire as the counter electrode, and Ag/AgCl as the reference electrode). The results show that both types of electrode systems generated similar cyclic voltammograms within the same potential window (-0.5 to +0.7 V). However, the novel PCB-based same-metal three-electrode electrochemical cell only required a few activation cycles and exhibited impressive cyclic voltametric repeatability with higher redox sensitivity and detection window, while using only trace amounts of solutions/analytes.
Microalgae gasification over Ni loaded perovskites for enhanced biohydrogen generation

Valizadeh S, Khani Y, Farooq A, Kumar G, Show PL, Chen WH, et al.

Bioresour Technol, 2023 Jan 18;372:128638.
PMID: 36669624 DOI: 10.1016/j.biortech.2023.128638

Steam gasification of microalgae upon perovskite oxide-supported nickel (Ni) catalysts was carried out for H2-rich gas production. Ni-perovskite oxide catalysts with partial substitution of B in perovskite structures (Ni/CaZrO3, Ni/Ca(Zr0.8Ti0.2)O3, and Ni/Ca(Zr0.6Ti0.4)O3) were synthesized and compared with those of the Ni/Al2O3 catalyst. The perovskite oxide supports improved Ni dispersion by reducing the particle size and strengthening the Ni-support interaction. Higher gas yields and H2 selectivity were obtained using Ni-perovskite oxide catalysts rather than Ni/Al2O3. In particular, Ni/Ca(Zr0.8Ti0.2)O3 showed the highest activity and selectivity for H2 production because of the synergetic effect of metallic Ni and elements present in the perovskite structures caused by high catalytic activity coupled with enhanced oxygen mobility. Moreover, increasing the temperature promoted the yield of gas and H2 content. Overall, considering the outstanding advantages of perovskite oxides as supports for Ni catalysts is a promising prospect for H2 production via gasification technology.
Fulltext Whole-genome sequencing of four culturable endophytic bacteria from German hardneck garlic cloves (Allium sativum L.)

Kumar G, Gan HM, Wengert P, Penix T, Parthasarathy A, Hudson AO, et al.

Microbiol Resour Announc, 2024 Apr 11;13(4):e0122523.
PMID: 38470029 DOI: 10.1128/mra.01225-23

We present the whole-genome sequence of four bacterial endophytes associated with German hardneck garlic cloves (Allium sativum L.). Among them, Agrobacterium fabrum and Pantoea agglomerans are associated with plant protection, while Rahnella perminowiae and Stenotrophomonas lactitubi are pathogens. These data will facilitate the identification of genes to improve garlic.
Fulltext Printed-Circuit-Board-Based Two-Electrode System for Electronic Characterization of Proteins

Talebi S, Daraghma SMA, Subramaniam RT, Bhassu S, Gnana Kumar G, Periasamy V

ACS Omega, 2020 Apr 14;5(14):7802-7808.
PMID: 32309689 DOI: 10.1021/acsomega.9b03831

Proteins have been increasingly suggested as suitable candidates for the fabrication of biological computers and other biomolecular-based electronic devices mainly due to their interesting structure-related intrinsic electrical properties. These natural biopolymers are environmentally friendly substitutes for conventional inorganic materials and find numerous applications in bioelectronics. Effective manipulation of protein biomolecules allows for accurate fabrication of nanoscaled device dimensions for miniaturized electronics. The prerequisite, however, demands an interrogation of its various electronic properties prior to understanding the complex charge transfer mechanisms in protein molecules, the knowledge of which will be crucial toward development of such nanodevices. One significantly preferred method in recent times involves the utilization of solid-state sensors where interactions of proteins could be investigated upon contact with metals such as gold. Therefore, in this work, proteins (hemoglobin and collagen) were integrated within a two-electrode system, and the resulting electronic profiles were investigated. Interestingly, structure-related electronic profiles representing semiconductive-like behaviors were observed. These characteristic electronic profiles arise from the metal (Au)-semiconductor (protein) junction, clearly demonstrating the formation of a Schottky junction. Further interpretation of the electronic behavior of proteins was done by the calculation of selected solid-state parameters. For example, the turn-on voltage of hemoglobin was measured to occur at a lower turn-on voltage, indicating the possible influence of the hem group present as a cofactor in each subunit of this tetrameric protein.
Fulltext Whole-Genome Sequence of Endophytic Bacteria Associated with Poison Ivy Vine (Toxicodendron radicans)

Gan HM, Penix TS, Wengert PC, Wong NH, Hudson AO, Kumar G, et al.

Microbiol Resour Announc, 2023 Apr 18;12(4):e0123222.
PMID: 36920211 DOI: 10.1128/mra.01232-22

Here, we report the genome assemblies of 11 endophytic bacteria, isolated from poison ivy vine (Toxicodendron radicans). Five species belonging to the genus Pseudomonas, two species of Curtobacterium, one strain of Pantoea agglomerans, and one species from the Bacillus, Cellulomonas, and Enterobacter genera were isolated from the interior tissue of poison ivy.
Diffusion-in-gel enzyme-linked immunosorbent assay, ELISA and IFA test in the detection of malarial antibodies

Kumar GS, Mak JW, Lam PL, Tan MA, Lim PK

Southeast Asian J Trop Med Public Health, 1987 Dec;18(4):502-6.
PMID: 3129797

Malarial antibodies in 80 patients were measured using the diffusion-in-gel enzyme linked immunosorbent assay (DIG-ELISA), enzyme-linked immunosorbent assay (ELISA) and the indirect fluorescent antibody (IFA) test. Good correlations were obtained between all three tests in terms of sensitivity and reliability. DIG-ELISA has the advantage of being a rapid diagnostic tool for the detection of malarial antibodies.
Assessment of the Efficacy of TMJ Arthroscopy-Assisted Masseter Nerve Avulsion on Hemimasticatory Spasm: An Original Research

Pillai AR, Kumar GJ, Kumar P, Nizar SA, Pendyala SK, Baig FAH

J Pharm Bioallied Sci, 2023 Jul;15(Suppl 1):S110-S113.
PMID: 37654296 DOI: 10.4103/jpbs.jpbs_430_22

The goal of this study is to find a cure for the masticatory muscle disease known as hemimasticatory spasm (HMS). This retrospective investigation intends to find a more efficient therapeutic approach for HMS patients by examining the clinical effectiveness of masseteric nerve avulsion performed on HMS using a temporomandibular arthroscope. A clinical study was piloted where the subjects were treated for masseter nerve avulsion by TMJ arthroscopy. The follow-up was done till 2 years, and the subjects were evaluated for the various characteristics like difficulties, masticatory abilities, and various sounds at the joint for the various functions of the joint. The diagnosis was done using the electrophysiological electromyogram (EMG) at the designated time intervals. There was a complete remission in all the subjects. The masseter nerve avulsion was effective since the scores lowered. Within 3 years of the operation, electrophysiological EMG depicted no discharge potential with a high frequency, and the total efficiency when paired with the clinical effectiveness was deemed acceptable. The maximal masseter power between the treated and nontreated sides was comparable. The mastication, on comparing, was also as effective as the normal side; however, lower mastication was noted in the first year. The avulsed nerve tissues lacked any apparent demyelination. Masseteric nerve avulsion with temporomandibular arthroscope assistance provided acceptable and stable total effectiveness for the intervention of the hemimasticatory spasm. While the strength of the muscle of the afflicted side was only marginally reduced, its masticatory effectiveness was optimally preserved.
Endophytic bacteria associated with wild-type banana seed (Musa balbisiana): whole genome sequencing

Kumar G, Gan HM, Popielarz H, Steele J, Parthasarathy A, Hudson AO, et al.

Microbiol Resour Announc, 2023 Nov 03.
PMID: 37921458 DOI: 10.1128/MRA.00650-23

We present the whole-genome sequences of five endophytic bacteria isolated from Musa balbisiana seeds. These strains represent five different genera: Bacillus, Brachybacterium, Enterobacter, Enterococcus, and Pantoea. Among these, three genera (Bacillus, Pantoea, and Enterobacter) were previously recognized for their antagonistic effects against Fusarium wilt, a highly destructive disease that affects banana plants.
Synthesis of Pectin and Eggshell Biowaste-Mediated Nano-hydroxyapatite (nHAp), Their Physicochemical Characterizations, and Use as Antibacterial Material

Thakur P, Arivarasan VK, Kumar G, Pant G, Kumar R, Pandit S, et al.

Appl Biochem Biotechnol, 2024 Jan;196(1):491-505.
PMID: 37145344 DOI: 10.1007/s12010-023-04550-6

The current study reports the synthesis of sustainable nano-hydroxyapatite (nHAp) using a wet chemical precipitation approach. The materials used in the green synthesis of nHAp were obtained from environmental biowastes such as HAp from eggshells and pectin from banana peels. The physicochemical characterization of obtained nHAp was carried out using different techniques. For instance, X-ray diffractometer (XRD) and FTIR spectroscopy were used to study the crystallinity and synthesis of nHAp respectively. In addition, the morphology and elemental composition of nHAP were studied using FESEM equipped with EDX. HRTEM showed the internal structure of nHAP and calculated its grain size which was 64 nm. Furthermore, the prepared nHAp was explored for its antibacterial and antibiofilm activity which has received less attention previously. The obtained results showed the potential of pectin-bound nHAp as an antibacterial agent for various biomedical and healthcare applications.

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