Trials and tribulations of conducting interventional studies in urban slums of a developing country: Experiences from Kolkata, India

Mahapatra, Tanmay,Mahapatra, Sanchita,Pal, Debottam,Saha, Jayanta,Lopez, AnnaLena,Ali, Mohammad,Bannerjee, Barnali,Manna, Byomkesh,Sur, Dipika,Bhattacharya, Sujit,Kanungo, Suman TaylorFrancis 2016 Human vaccines & immunotherapeutics Vol.12 No.1

<P>Experimental studies involving human subjects provide most internally valid evidences in epidemiological research due to their robust methodology. While conducting population-based interventional studies, to achieve external validity, inclusion of information from vulnerable groups like urban slum-dwellers of the developing world, in the epidemiological estimates is of paramount importance. The challenges faced while conducting 2 consecutive large-scale, community-based vaccine trials in urban slums of Kolkata, India are presented in this article. Interventions in these communities often get constrained by issues pertaining to human rights and benefits, socio-cultural factors, political environment, methodological shortcomings in addition to the challenges in ensuring community participation. While conducting these trials although we intermittently faced obstacles, by virtue of having a long term and robust surveillance system and developing a trusted relationship between the researchers, community leaders and residents we were able to come up with a commendable community participation which culminated into the success of the interventions. Bridging the gap between research and field operations by incorporating knowledge gathered from interventional studies and making strategies to improve health conditions of these informal settlers is a major unfulfilled agenda. We believe the lessons learnt during our research will help researchers while developing efficient interventions in similar setting.</P>

Fuzzy decision-making on reliability of series system: Fuzzy geometric programming approach

G. S. Mahapatra,B. S. Mahapatra,P. K. Roy 원광대학교 기초자연과학연구소 2011 ANNALS OF FUZZY MATHEMATICS AND INFORMATICS Vol.1 No.1

In this paper, we have presented different type of fuzzy geometric programming based on fuzzy decision-making through max-min and max-additive operators. These operators are applied in the series system reliability model in fuzzy environment. In the problem we have considered reliability of series system with limited system cost as a constraint function. Numerical examples are given to illustrate fuzzy decision-making based fuzzy geometric programming on series system reliability model.

Investigation of structure–property correlation on the dielectric and optical properties of lanthanum modified barium titanate ceramic

Mahapatra A. K.,Badapanda T.,Sahoo S.,Sarangi S. 한국세라믹학회 2022 한국세라믹학회지 Vol.59 No.6

The present manuscript outlines the investigation of the structure, dielectric and optical properties of Lanthanum (La) doped BaTiO 3 (BLT) ceramic with compositions of Ba 1-xLa2x/3TiO 3 prepared by the solid-state reaction method. The Rietveld refi nement of the XRD pattern illustrates that La doping changes from tetragonal structure to cubic structure with a mixed phase in intermediate composition. The Raman spectra illustrate the existence of modes associated with tetragonal symmetry up to x = 0.05 and the disappearance of modes at 307  cm −1 confi rming the cubic symmetry for higher doping concentration. The temperature variant dielectric study in the studied range reveals a two-phase transition until x = 0.05 which merges for higher concentrations. The temperature variant dielectric study expresses that the transition temperature declines whereas the dielectric constant at transition temperature increases as a function of doping content. The dielectric loss of the doped samples is found to increase until x = 0.05 and thereby decreases for higher concentration values. The temperature coeffi cient of the dielectric constant was calculated for all the compositions. The diff usivity was calculated using the altered Curie–Wiess law revealing that the diff usivity increases because of doping percentages. A signature of relaxor nature is obtained in the composition x = 0.1, which is confi rmed by the Vogel–Fulcher (VF) fi tting. The optical property of all the prepared samples has been studied using UV–Vis spectroscopy and photoluminescence.

Nano-shape varied cerium oxide nanomaterials rescue human dental stem cells from oxidative insult through intracellular or extracellular actions

Mahapatra, Chinmaya,Singh, Rajendra K.,Lee, Jung-Hwan,Jung, Jieun,Hyun, Jung Keun,Kim, Hae-Won Elsevier Science B.V. Amsterdam 2017 ACTA BIOMATERIALIA Vol. No.

<P><B>Abstract</B></P> <P>Cerium oxide nanomaterials (CeNMs), due to their excellent scavenging properties of reactive oxygen species (ROS), have gained great promise for therapeutic applications. A high level of ROS often degrades the potential of stem cells in terms of survivability, maintenance and lineage differentiation. Here we hypothesize the CeNMs may play an important role in protecting the capacity of stem cells against the oxidative insult, and the suppression mechanism of ROS level may depend on the internalization of CeNMs. We synthesized CeNMs with different directional shapes (aspect ratios) by a pH-controlled hydrothermal method, and treated them to stem cells derived from human dental pulp at various doses. The short CeNMs (nanoparticles and nanorods) were internalized rapidly to cells whereas long CeNMs (nanowires) were slowly internalized, which led to different distributions of CeNMs and suppressed the ROS levels either intracellularly or extracellularly under the H<SUB>2</SUB>O<SUB>2</SUB>-exposed conditions. Resultantly, the stem cells, when dosed with the CeNMs, were rescued to have excellent cell survivability; the damages in intracellular components including DNA fragmentation, lipid rupture and protein degradation were significantly alleviated. The findings imply that the ROS-scavenging events of CeNMs need special consideration of aspect ratio-dependent cellular internalization, and also suggest the promising use of CeNMs to protect stem cells from the ROS-insult environments, which can ultimately improve the stem cell potential for tissue engineering and regenerative medicine uses.</P> <P><B>Statement of Significance</B></P> <P>Oxidative stress governs many stem cell functions like self-renewal and lineage differentiation, and the biological conditions involving tissue repair and disease cure where stem cell therapy is often needed. Here we demonstrate the unique role of cerium oxide nanomaterials (CeNMs) in rescuing stem cell survivability, migration ability, and intracellular components from oxidative stress. In particular, we deliver a novel finding that nano-morphologically varied CeNMs show different mechanisms in their scavenging reactive oxygen species either intracellularly or extracellularly, and this is related with their different cellular internalizations. We used human dental pulp stem cells for the model study and proved the CeNMs were effective in controlling ROS level by means of scavenging intracellularly or extracellularly, which ultimately led to improving the intact therapeutic potential of stem cells. This work touches an important biological issue of nanomaterial interactions with stem cells under the conditions related with oxidative stress and the resultant damage. The correlation of shape factor in therapeutic nanomaterials with stem cell interaction and the oxidative stress-related functions will provide informative ideas in the design of CeNMs for cellular therapy.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Nanodiamond-grafted hyperbranched polymers anchored with carbon nanotubes: Mechanical, thermal, and photothermal shape-recovery properties

Mahapatra, Sibdas Singha,Yadav, Santosh K.,Lee, Byung Hak,Cho, Jae Whan Elsevier 2019 Polymer Vol.160 No.-

<P><B>Abstract</B></P> <P>Nanodiamond-grafted hyperbranched polyurethanes (HPU-g-NDs) with various nanodiamond (ND) loadings were synthesized and composites with multi-walled carbon nanotubes (MWNTs) were prepared. The HPU-g-ND/MWNT composites showed significantly improved mechanical, thermal, and photothermal shape-recovery properties, compared to the HPU-g-NDs. Scanning electron microscopy of fractured surfaces revealed that the HPU-g-NDs are highly compatible with the polymer matrix as well as the highly dispersed MWNTs. The mechanical properties of the HPU-g-NDs were profoundly enhanced by the addition of MWNTs. The breaking stress and modulus of the HPU-g-ND (1 wt% ND) composite were enhanced by 29% and 42%, respectively, with the incorporation of only 1 wt% MWNTs. An exceptional increase in thermal stability, of about 60 °C at a weight loss of 50%, was observed for HPU-g-ND at 1 wt% ND, compared with that of pure HPU; this composite also exhibited better shape recovery and faster actuation behavior during laser-driven photothermal actuation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Covalently bonded hyperbranched polyurethane with nanodiamonds was synthesized. </LI> <LI> The MWNTs enhanced the mechanical properties of the HPU-g-ND composites. </LI> <LI> An exceptional increase in thermal degradation temperature was observed for HPU-g-ND composites. </LI> <LI> The HPU-g-ND/MWNT composites exhibited excellent photothermal shape recovery and fast actuation speed. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A MULTIOBJECTIVE MODEL OF WHOLESALER-RETAILERS' PROBLEM VIA GENETIC ALGORITHM

MAHAPATRA, NIRMAL KUMAR,BHUNIA, ASOKE KUMAR,MAITI, MANORANJAN 한국전산응용수학회 2005 Journal of applied mathematics & informatics Vol.19 No.1

In the existing literature, most of the purchasing models were developed only for retailers problem ignoring the constraint of storage capacity of retailers shop/showroom. In this paper, we have developed a deterministic model of wholesaler-retailers' problem of single product. The storage capacity of wholesaler's warehouse/showroom and retailers' showroom/shop are assumed to be finite. The items are transported from wholesaler's warehouse to retailers' Own Warehouse (OW) in a lot. The customer's demand is assumed to be displayed inventory level dependent. Demands are met from OW and that spaces of OW will immediately be filled by shifting the same amount from the Rented Warehouse (RW) till the RW is empty. The time duration between selling from OW and filling up its space by new ones from RW is negligible. According to relative size of the retailers' existing (own) warehouse capacity and the demand factors, different scenarios are identified. Our objectives are to optimize the cost functions of wholesaler and two retailers separately. To solve this problem, a real coded Genetic Algorithm (GA) with roulette wheel selection/reproduction, whole arithmetic crossover and non-uniform mutation is developed. Finally a numerical example is presented to illustrate the results for different scenarios. To compare the results of GA, Generalised Reduced Gradient Method has been used for the problem. Also, a sensitivity analysis has been performed to study the variations of the optimal average cost with respect to the different parameters.

Osteopromoting Reservoir of Stem Cells: Bioactive Mesoporous Nanocarrier/Collagen Gel through Slow-Releasing FGF18 and the Activated BMP Signaling

Mahapatra, Chinmaya,Singh, Rajendra K.,Kim, Jung-Ju,Patel, Kapil D.,Perez, Roman A.,Jang, Jun-Hyeog,Kim, Hae-Won American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.41

<P>Providing an osteogenic stimulatory environment is a key strategy to construct stem cell-based bone-equivalent tissues. Here we design a stem cell delivering gel matrix made of collagen (Col) with bioactive glass nanocarriers (BGn) that incorporate osteogenic signaling molecule, fibroblast growth factor 18 (FGF18), a reservoir considered to cultivate and promote osteogenesis of mesenchymal stem cells (MSCs). The presence of BGn in the gel was shown to enhance the osteogenic differentiation of MSCs, possibly due to the therapeutic role of ions released. The mesoporous nature of BGn was effective in loading FGF18 at large quantity, and the FGF18 release from the BGn-Col gel matrix was highly sustainable with almost a zero-order kinetics, over 4 weeks as confirmed by the green fluorescence protein signal change. The released FGF18 was effective in accelerating osteogenesis (alkaline phosphatase activity and bone related gene expressions) and bone matrix formation (osteopontin, bone sialoprotein, and osteocalcin production) of MSCs. This was attributed to the bone morphogenetic protein (BMP) signaling pathway, where the FGF18 release stimulated the endogenous secretion of BMP2 and the downstream signal Smad1/5/8. Taken together, the FGF18-BGn/Col gel is considered an excellent osteopromoting depot to support and signal MSCs for bone tissue engineering.</P>

Synthesis and characterization of multi-walled carbon nanotubes functionalized with hyperbranched poly(urea-urethane).

Mahapatra, Sibdas Singha,Yadav, Santosh Kumar,Cho, Jae Whan American Scientific Publishers 2010 Journal of nanoscience and nanotechnology Vol.10 No.12

<P>Two types of hyperbranched poly(urea-urethane)-functionalized multi-walled carbon nanotubes (GHPU) have been synthesized in the presence of bis- and tris-hydroxy terminated carbon nanotubes (MWNT-OH). For comparison of the grafting efficiency on carbon nanotubes, pure hyper-branched poly(urea-urethane)s (HPUs) were also synthesized to prepare pristine carbon nanotubes-reinforced nanocomposites (HPNTs). Better MWNT dispersion in the polymer matrix was obtained for GHPU than for HPNT, and the effect was superior in the case of highly branched GHPU from tris-hydroxy-functionalized MWNTs, compared to GHPU from bis-hydroxy-functionalized MWNTs. TEM measurements for GHPUs clearly showed hyperbranched polymer-wrapped MWNT structures. Crystallization of hyperbranched polymers in GHPU was more developed than that of the HPNT nanocomposites, although MWNT-induced crystallization was observed for both the GHPU and HPNT samples. The hyperbranched polymer-grafting effect on MWNTs resulted in greater enhancement of the mechanical properties of GHPU at the same nanotube loading, compared to the case of HPNT nanocomposites. However, a too highly branched structure was found to lower the crystallization and mechanical properties of both the GHPUs and HPNTs.</P>

Pyrolysis kinetics and thermodynamics of discarded Bakelite

Mahapatra Pabitra Mohan,Panda Achyut Kumar,Ahmed Sahin,Kumar Sachin 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.6

The thermal degradation kinetics of discarded Bakelite was studied by using different model fitting, model-free methods (Kissinger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa (FWO), Friedman (FRM), Starink (STR), Li and Tang (LTA), Vyazovkin (VYZ), Avrami (AVM)) and Master plot (MP), for computing the kinetics triplets (A, Ea, and n) and also predict a suitable mechanism. The thermal degradation experiment of the sample was carried out from ambient to 1,000 °C at five different heating rates 5, 10, 20, 30, and 50 °C/min. under inert gas N2 atmosphere. The thermal degradation of discarded Bakelite shows an order-based F5 — model mechanism with the activation energy (Ea) of 213 KJ/mol, and the accuracy of the Ea was also proved by KAS, FWO, and VYZ iso-conversional method. The ordered-based model for the reaction mechanism was also explained by the master plot (MP). Based on the results of the non-linear method (VYZ), the mean error percentage of Ea, which is tested for various linear ways, was found to increase in the following order: FWO<KAS<STR<FRM<LTA and ranged from 0.115% to 23.492% for the degradation of discarded Bakelite. The change in free energy (ΔG), change in enthalpy (ΔH), and change in entropy (ΔS) are 560.743 KJ/mol, 100.835 KJ/mol, and −820.989× 10−3 JK−1 mol−1, respectively. The complete kinetic and thermodynamics analysis of the thermal degradation would help to design a process for the conversion of these wastes to high-valued carbonaceous products.

Electrical response of microcellular EPDM rubber composites: complex dielectric modulus formalism and current–voltage characteristics

Mahapatra, S. P.,Tripathy, D. K.,Lee, Y. Springer-Verlag 2012 Polymer bulletin Vol.68 No.7