Displaying publications 41 - 60 of 66 in total

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  1. Mazaheri H, Lee KT, Bhatia S, Mohamed AR
    Bioresour Technol, 2010 Oct;101(19):7641-7.
    PMID: 20510608 DOI: 10.1016/j.biortech.2010.04.072
    Thermal decomposition of oil palm fruit press fiber (FPF) with sub/supercritical methanol, ethanol, acetone, and 1,4-dioxane treatments were investigated using a high-pressure autoclave reactor. When FPF was decomposed with methanol, ethanol, and acetone from 483 to 603 K, the highest degree of conversion obtained were 81.5%, 77.8%, and 67.9% while the highest liquid product yield (LP) obtained were 38.0%, 36.9%, and 38.5%, respectively. For the case of 1,4-dioxane, the conversion of FPF increased from 18.30% to 80.00%, while LP yield increased dramatically from 13.30% to 50.90% (consisting of 42.3% bio-oil compounds) when the reaction temperature was increased from 483 to 563 K. However, the conversion of FPF and LP yield decreased to 69.60% and 24.10%, respectively, when the temperature was further increased to 603 K. Comparison between all the solvents, subcritical 1,4-dioxane treatment was found very effective in the degradation of FPF to produce bio-oil component.
  2. Mazaheri H, Lee KT, Bhatia S, Mohamed AR
    Bioresour Technol, 2010 Dec;101(23):9335-41.
    PMID: 20656481 DOI: 10.1016/j.biortech.2010.07.004
    Thermal decomposition of oil palm fruit press fiber (FPF) into a liquid product (LP) was achieved using subcritical water treatment in the presence of sodium hydroxide in a high pressure batch reactor. This study uses experimental design and process optimisation tools to maximise the LP yield using response surface methodology (RSM) with central composite rotatable design (CCRD). The independent variables were temperature, residence time, particle size, specimen loading, and additive loading. The mathematical model that was developed fit the experimental results well for all of the response variables that were studied. The optimal conditions were found to be a temperature of 551 K, a residence time of 40 min, a particle size of 710-1000 microm, a specimen loading of 5 g, and a additive loading of 9 wt.% to achieve a LP yield of 76.16%.
  3. Mazaheri H, Lee KT, Bhatia S, Mohamed AR
    Bioresour Technol, 2010 Jan;101(2):745-51.
    PMID: 19740652 DOI: 10.1016/j.biortech.2009.08.042
    Decomposition of oil palm fruit press fiber (FPF) to various liquid products in subcritical water was investigated using a high-pressure autoclave reactor with and without the presence of catalyst. When the reaction was carried in the absence of catalyst, the conversion of solid to liquid products increased from 54.9% at 483 K to 75.8% at 603 K. Simultaneously, the liquid yield increased from 28.8% to 39.1%. The liquid products were sub-categorized to bio-oil (benzene soluble, diethylether soluble, acetone soluble) and water soluble. When 10% ZnCl(2) was added, the conversion increased slightly but gaseous products increased significantly. However, when 10% Na(2)CO(3) and 10% NaOH were added independently, the solid conversion increased to almost 90%. In the presence of catalyst, the liquid products were mainly bio-oil compounds. Although solid conversion increased at higher reaction temperature, but the liquid yield did not increase at higher temperature.
  4. Min CS, Bhatia S, Kamaruddin AH
    Artif Cells Blood Substit Immobil Biotechnol, 1999 Sep-Nov;27(5-6):417-21.
    PMID: 10595442
    Continuous hydrolysis of palm oil triglyceride in organic solvent using immobilized Candida rugosa on the Amberlite MB-1 as a source of immobilized lipase was studied in packed bed reactor. The enzymatic kinetics of hydrolysis reaction was studied by changing the substrate concentration, reaction temperature and residence time(tau) in the reactor. At 55 degrees C, the optimum water concentration was found to be 15 % weight per volume of solution (%w/v). The Michaelis-Menten kinetic model was used to obtain the reaction parameters, Km(app) and V max(app). The activation energies were found to be quite low indicating that the lipase-catalyzed process is controlled by diffusion of substrates. The Michaelis-Menten kinetic model was found to be suitable at low water concentration 10-15 %w/v of solution. At higher water concentration, substrate inhibition model was used for data analysis. Reactor operation was found to play an important role in the palm oil hydrolysis kinetic.
  5. Modi R, Kohli S, Rajeshwari K, Bhatia S
    Eur J Dent, 2015 6 4;9(2):255-261.
    PMID: 26038660 DOI: 10.4103/1305-7456.156847
    OBJECTIVE: The aim of the study is to evaluate the stress distribution in tooth supported 5-unit fixed partial denture (FPD) having tooth as pier abutment using rigid and nonrigid connectors respectively, under simultaneous and progressive loading.

    MATERIAL AND METHODS: The three-dimensional (3D) finite element program (ANSYS software) was used to construct the mathematical model. Two 5-unit FPD'S were simulated, one with rigid connector and another one with nonrigid connector. For analysis, each of these models were subjected to axial and oblique forces under progressive loading (180, 180, 120, 120, 80 N force on first and second molars, premolars and canine respectively) and simultaneous loading (100, 100, 100, 100, 100 N force on first and second molars, premolars and canine respectively).

    RESULTS: The rigid and nonrigid connector design have effect on stress distribution in 5-unit FPDs with pier abutments.

    CONCLUSION: Oblique forces produce more stresses than vertical forces. Nonrigid connector resulted in decrease in stress at the level of prosthesis and increase in stress at the level of alveolar crest.

  6. Nagendrababu V, Pulikkotil SJ, Suresh A, Veettil SK, Bhatia S, Setzer FC
    Int Endod J, 2019 Jun;52(6):779-789.
    PMID: 30638269 DOI: 10.1111/iej.13072
    The management of pain during root canal treatment is important. The aim of this systematic review and network meta-analysis was to identify the anaesthetic solution that would provide the best pulpal anaesthesia for inferior alveolar nerve blocks (IANB) treating mandibular teeth with irreversible pulpitis. Two electronic databases (PubMed and Scopus) were searched to identify studies up to October 2018. Randomized clinical trials comparing at least two anaesthetic solutions (lidocaine (lignocaine), articaine, bupivacaine, prilocaine or mepivacaine) used for IANB for treatment of irreversible pulpitis were included. The revised Cochrane risk of bias tool for randomized trials was used to assess the quality of the included studies. Pairwise meta-analysis, network meta-analysis using a random-effects model, and SUCRA ranking were performed. The network meta-analysis estimated the probability of each treatment performing best. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations approach. In total, 11 studies (n = 750) were included in the meta-analysis. The network meta-analysis revealed that only mepivacaine significantly increased the success rate of IANB compared to lidocaine (RR, 1.42 [95% CI 1.04-1.95]). However, no significant differences in the success rate of IANB were observed between mepivacaine and other anaesthetic agents (articaine and bupivacaine). Of all anaesthetic agents, mepivacaine (SUCRA = 0.81) ranked first in increasing the success rate of IANB, followed by prilocaine (SUCRA = 0.62), articaine (SUCRA = 0.54), bupivacaine (SUCRA = 0.41) and lidocaine (SUCRA = 0.13). The overall quality of evidence was very low to moderate. In conclusion, based on the evidence from the randomized clinical trials included in this review, mepivacaine with epinephrine demonstrated the highest probability of providing effective pulpal anaesthesia using IANB for teeth with irreversible pulpitis compared to prilocaine, articaine, bupivacaine and lidocaine. Further, high-quality clinical trials are needed to support the conclusion of this review.
  7. Naik SV, K R, Kohli S, Zohabhasan S, Bhatia S
    Open Dent J, 2016;10:196-206.
    PMID: 27386005 DOI: 10.2174/1874210601610010196
    The usage of ozone in dentistry has been proposed because of its antimicrobial, disinfectant, biocompatibility and healing properties. In the last decade a number of therapeutic protocols with ozone have been developed to address common dental infections associated with periodontal disease, RCT and caries. Despite these advantages, therapeutic ozone's application in dentistry is limited because of its possible side effects. Hence, dental practitioners need to know the proper usage of ozone therapy that can provide better patient care and considerably cut down the time and cost of the treatment.
  8. Nijhawan P, Behl T, Chigurupati S, Sehgal A, Singh S, Sharma N, et al.
    PMID: 34997511 DOI: 10.1007/s11356-022-18531-5
    Obesity is a multifaceted disease encompassing deposition of an unnecessary amount of fat which upsurges the possibility of other complications, viz., hypertension and certain type of cancers. Although obesity results from combination of genetic factors, improper diet and inadequate physical exercise also play a major role in its onset. The present study aims at exploring the anti-obesity activity of Crinum latifolia leaf extract in obese rats. The leaves were extracted using hydroalcoholic extraction which was later diluted with water and given to obese rats. The dosing was started from the 4th week (by oral administration of extract of Crinum latifolia (100 mg/kg and 200 mg/kg) and combination of Crinum latifolia leaf extract 200 mg/kg and orlistat 30 mg/kg) till the 10th week. Various angiogenic, antioxidant, biochemical, and inflammatory biomarkers were assessed at the end of the study. The obese symptoms were progressively reduced in treatment groups when compared to disease control groups. The angiogenic parameters and inflammatory parameters were consequently reduced in treatment groups. The oxidative parameters superoxide dismutase (SOD) and catalase were gradually increased, while levels of TBARS were reduced in treatment groups showing antioxidant nature of leaf hydroalcoholic extract. The Crinum latifolia leaf extract possesses anti-obesity properties and therefore can be used as a therapeutic option in the management of obesity.
  9. Ong AL, Kamaruddin AH, Bhatia S, Aboul-Enein HY
    J Sep Sci, 2008 Jul;31(13):2476-85.
    PMID: 18646277 DOI: 10.1002/jssc.200800086
    An enzymatic membrane reactor (EMR) for enantioseparation of (R,S)-ketoprofen via Candida antarctica lipase B (CALB) as biocatalyst was investigated. A comparative study of free and immobilized CALB was further conducted. The catalytic behaviour of CALB in an EMR was affected by the process parameters of enzyme load, substrate concentration, substrate molar ratio, lipase solution pH, reaction temperature, and substrate flow rate. Immobilization of CALB in the EMR was able to reduce the amount of enzyme required for the enantioseparation of (R,S)-ketoprofen. Immobilized CALB in the EMR assured higher reaction capacity, better thermal stability, and reusability. It was also found to be more cost effective and practical than free CALB in a batch reactor.
  10. Pan JYY, Parolia A, Chuah SR, Bhatia S, Mutalik S, Pau A
    BMC Oral Health, 2019 01 14;19(1):14.
    PMID: 30642318 DOI: 10.1186/s12903-019-0710-z
    BACKGROUND: To determine the root canal morphology of human permanent maxillary and mandibular teeth in a Malaysian subpopulation using cone-beam computed tomography (CBCT).

    METHODS: A total of 208 CBCT images were examined retrospectively. Prevalence of an extra root/canal and internal morphology based on Vertucci's classification were observed in human maxillary and mandibular permanent teeth. Variations in the external and internal morphology were compared in relation to gender and tooth side (left vs right) using Pearson Chi-square and Fisher's exact tests with significance level set at p 

  11. Rengarajan A, Rogers BD, Wong Z, Tolone S, Sifrim D, Serra J, et al.
    Clin Gastroenterol Hepatol, 2022 Mar;20(3):e398-e406.
    PMID: 33144149 DOI: 10.1016/j.cgh.2020.10.052
    OBJECTIVE: High-resolution manometry (HRM) is the current standard for characterization of esophageal body and esophagogastric junction (EGJ) function. We aimed to examine the prevalence of abnormal esophageal motor patterns in health, and to determine optimal thresholds for software metrics across HRM systems.

    DESIGN: Manometry studies from asymptomatic adults were solicited from motility centers worldwide, and were manually analyzed using integrated relaxation pressure (IRP), distal latency (DL), and distal contractile integral (DCI) in standardized fashion. Normative thresholds were assessed using fifth and/or 95th percentile values. Chicago Classification v3.0 criteria were applied to determine motor patterns across HRM systems, study positions (upright vs supine), ages, and genders.

    RESULTS: Of 469 unique HRM studies (median age 28.0, range 18-79 years). 74.6% had a normal HRM pattern; none had achalasia. Ineffective esophageal motility (IEM) was the most frequent motor pattern identified (15.1% overall), followed by EGJ outflow obstruction (5.3%). Proportions with IEM were lower using stringent criteria (10.0%), especially in supine studies (7.1%-8.5%). Other motor patterns were rare (0.2%-4.1% overall) and did not vary by age or gender. DL thresholds were close to current norms across HRM systems, while IRP thresholds varied by HRM system and study position. Both fifth and 95th percentile DCI values were lower than current thresholds, both in upright and supine positions.

    CONCLUSIONS: Motor abnormalities are infrequent in healthy individuals and consist mainly of IEM, proportions of which are lower when using stringent criteria in the supine position. Thresholds for HRM metrics vary by HRM system and study position.

  12. Rogers BD, Rengarajan A, Abrahao L, Bhatia S, Bor S, Carlson DA, et al.
    Neurogastroenterol Motil, 2021 06;33(6):e14009.
    PMID: 33094875 DOI: 10.1111/nmo.14009
    BACKGROUND: Esophagogastric junction contractile integral (EGJ-CI) and EGJ morphology are high-resolution manometry (HRM) metrics that assess EGJ barrier function. Normative data standardized across world regions and HRM manufacturers are limited.

    METHODS: Our aim was to determine normative EGJ metrics in a large international cohort of healthy volunteers undergoing HRM (Medtronic, Laborie, and Diversatek software) acquired from 16 countries in four world regions. EGJ-CI was calculated by the same two investigators using a distal contractile integral-like measurement across the EGJ for three respiratory cycles and corrected for respiration (mm Hg cm), using manufacturer-specific software tools. EGJ morphology was designated according to Chicago Classification v3.0. Median EGJ-CI values were calculated across age, genders, HRM systems, and regions.

    RESULTS: Of 484 studies (28.0 years, 56.2% F, 60.7% Medtronic studies, 26.0% Laborie, and 13.2% Diversatek), EGJ morphology was type 1 in 97.1%. Median EGJ-CI was similar between Medtronic (37.0 mm Hg cm, IQR 23.6-53.7 mm Hg cm) and Diversatek (34.9 mm Hg cm, IQR 22.1-56.1 mm Hg cm, P = 0.87), but was significantly higher using Laborie equipment (56.5 mm Hg cm, IQR 35.0-75.3 mm Hg cm, P 

  13. Sharma N, Zahoor I, Sachdeva M, Subramaniyan V, Fuloria S, Fuloria NK, et al.
    Environ Sci Pollut Res Int, 2021 Nov;28(43):60459-60476.
    PMID: 34545518 DOI: 10.1007/s11356-021-16570-y
    Meningitis is an inflammation of the protective membranes called meninges and fluid adjacent the brain and spinal cord. The inflammatory progression expands all through subarachnoid space of the brain and spinal cord and occupies the ventricles. The pathogens like bacteria, fungi, viruses, or parasites are main sources of infection causing meningitis. Bacterial meningitis is a life-threatening health problem that which needs instantaneous apprehension and treatment. Nesseria meningitidis, Streptococcus pneumoniae, and Haemophilus flu are major widespread factors causing bacterial meningitis. The conventional drug delivery approaches encounter difficulty in crossing this blood-brain barrier (BBB) and therefore are insufficient to elicit the desired pharmacological effect as required for treatment of meningitis. Therefore, application of nanoparticle-based drug delivery systems has become imperative for successful dealing with this deadly disease. The nanoparticles have ability to across BBB via four important transport mechanisms, i.e., paracellular transport, transcellular (transcytosis), endocytosis (adsorptive transcytosis), and receptor-mediated transcytosis. In this review, we reminisce distinctive symptoms of meningitis, and provide an overview of various types of bacterial meningitis, with a focus on its epidemiology, pathogenesis, and pathophysiology. This review describes conventional therapeutic approaches for treatment of meningitis and the problems encountered by them while transmitting across tight junctions of BBB. The nanotechnology approaches like functionalized polymeric nanoparticles, solid lipid nanoparticles, nanostructured lipid carrier, nanoemulsion, liposomes, transferosomes, and carbon nanotubes which have been recently evaluated for treatment or detection of bacterial meningitis have been focused. This review has also briefly summarized the recent patents and clinical status of therapeutic modalities for meningitis.
  14. Sim JH, Kamaruddin AH, Bhatia S
    Bioresour Technol, 2010 Dec;101(23):8948-54.
    PMID: 20675129 DOI: 10.1016/j.biortech.2010.07.039
    The objective of this research is to investigate the potential of transesterification of crude palm oil (CPO) to biodiesel at 30 degrees C. The mass transfer limitations problem crucial at 30 degrees C due to the viscosity of CPO has been addressed. The process parameters that are closely related to mass transfer effects like enzyme loading, agitation speed and reaction time were optimized. An optimum methanol to oil substrate molar ratio at 6.5:1 was observed and maintained throughout the experiments. The optimum operating condition for the transesterification process was found at 6.67 wt% of enzyme loading and at 150 rpm of agitation speed. The corresponding initial reaction and FAME yield obtained at 6 h were 89.29% FAME yield/hr and 85.01%, respectively. The 85% FAME yield obtained at 30 degrees C operation of CPO transesterification shows that the process is potentially feasible for the biodiesel synthesis.
  15. Singh R, Jayanna M, Wong J, Lim LG, Zhang J, Lv J, et al.
    Endosc Int Open, 2015 Feb;3(1):E14-8.
    PMID: 26134765 DOI: 10.1055/s-0034-1377610
    The advent and utility of new endoscopic imaging modalities for predicting the histology of Barrett's esophagus (BE) in real time with high accuracy appear promising and could potentially obviate the need to perform random biopsies where guidelines are poorly adhered to. We embarked on evaluating the performance characteristics of white-light endoscopy with magnification (WLE-z), narrow-band imaging with magnification (NBI-z) and a combination of both modalities.
  16. Sugano K, Spechler SJ, El-Omar EM, McColl KEL, Takubo K, Gotoda T, et al.
    Gut, 2022 Aug;71(8):1488-1514.
    PMID: 35725291 DOI: 10.1136/gutjnl-2022-327281
    OBJECTIVE: An international meeting was organised to develop consensus on (1) the landmarks to define the gastro-oesophageal junction (GOJ), (2) the occurrence and pathophysiological significance of the cardiac gland, (3) the definition of the gastro-oesophageal junctional zone (GOJZ) and (4) the causes of inflammation, metaplasia and neoplasia occurring in the GOJZ.

    DESIGN: Clinical questions relevant to the afore-mentioned major issues were drafted for which expert panels formulated relevant statements and textural explanations.A Delphi method using an anonymous system was employed to develop the consensus, the level of which was predefined as ≥80% of agreement. Two rounds of voting and amendments were completed before the meeting at which clinical questions and consensus were finalised.

    RESULTS: Twenty eight clinical questions and statements were finalised after extensive amendments. Critical consensus was achieved: (1) definition for the GOJ, (2) definition of the GOJZ spanning 1 cm proximal and distal to the GOJ as defined by the end of palisade vessels was accepted based on the anatomical distribution of cardiac type gland, (3) chemical and bacterial (Helicobacter pylori) factors as the primary causes of inflammation, metaplasia and neoplasia occurring in the GOJZ, (4) a new definition of Barrett's oesophagus (BO).

    CONCLUSIONS: This international consensus on the new definitions of BO, GOJ and the GOJZ will be instrumental in future studies aiming to resolve many issues on this important anatomic area and hopefully will lead to better classification and management of the diseases surrounding the GOJ.

  17. Sumathi S, Bhatia S, Lee KT, Mohamed AR
    J Hazard Mater, 2010 Apr 15;176(1-3):1093-6.
    PMID: 20018447 DOI: 10.1016/j.jhazmat.2009.11.037
    This work examines the impregnated carbon-based sorbents for simultaneous removal of SO(2) and NOx from simulated flue gas. The carbon-based sorbents were prepared using palm shell activated carbon (PSAC) impregnated with several metal oxides (Ni, V, Fe and Ce). The removal of SO(2) and NOx from the simulated flue gas was investigated in a fixed-bed reactor. The results showed that PSAC impregnated with CeO(2) (PSAC-Ce) reported the highest sorption capacity among other impregnated metal oxides for the simultaneous removal of SO(2) and NOx. PSAC-Ce showed the longest breakthrough time of 165 and 115 min for SO(2) and NOx, respectively. The properties of the pure and impregnated PSAC were analyzed by BET, FTIR and XRF. The physical-chemical features of the PSAC-Ce sorbent indicated a catalytic activity in both the sorption of SO(2) and NOx. The formation of both sulfate (SO(4)(2-)) and nitrate (NO(3-)) species on spent PSAC-Ce further prove the catalytic role played by CeO(2).
  18. Sumathi S, Bhatia S, Lee KT, Mohamed AR
    Bioresour Technol, 2009 Feb;100(4):1614-21.
    PMID: 18952414 DOI: 10.1016/j.biortech.2008.09.020
    Optimizing the production of microporous activated carbon from waste palm shell was done by applying experimental design methodology. The product, palm shell activated carbon was tested for removal of SO2 gas from flue gas. The activated carbon production was mathematically described as a function of parameters such as flow rate, activation time and activation temperature of carbonization. These parameters were modeled using response surface methodology. The experiments were carried out as a central composite design consisting of 32 experiments. Quadratic models were developed for surface area, total pore volume, and microporosity in term of micropore fraction. The models were used to obtain the optimum process condition for the production of microporous palm shell activated carbon useful for SO2 removal. The optimized palm shell activated carbon with surface area of 973 m(2)/g, total pore volume of 0.78 cc/g and micropore fraction of 70.5% showed an excellent agreement with the amount predicted by the statistical analysis. Palm shell activated carbon with higher surface area and microporosity fraction showed good adsorption affinity for SO2 removal.
  19. Tamunaidu P, Bhatia S
    Bioresour Technol, 2007 Dec;98(18):3593-601.
    PMID: 17208441
    Oil palm is widely grown in Malaysia. Palm oil has attracted the attention of researchers to develop an 'environmentally friendly' and high quality fuel, free of nitrogen and sulfur. In the present study, the catalytic cracking of palm oil to biofuel was studied over REY catalyst in a transport riser reactor at atmospheric pressure. The effect of reaction temperature (400-500 degrees C), catalyst/palm oil ratio (5-10) and residence time (10-30s) was studied over the yield of bio-gasoline and gas as fuel. Design of experiments was used to study the effect of operating variables over conversion of palm oil and yield of hydrocarbon fuel. The response surface methodology was used to determine the optimum value of the operating variables for maximum yield of bio-gasoline fraction in the liquid product obtained.
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