122 results on '"Mondal PK"'
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2. Quantitative characterization of fluorine-centered noncovalent interactions in crystalline benzanilides.
- Author
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Mondal PK, Shukla R, Khandelwal S, Sharma K, Gonde S, Biswas S, Som S, and Chopra D
- Abstract
Six isomeric molecules, featuring a minimum of three fluorine atoms on either the benzoyl or aniline side, have been synthesized, crystallized and characterized through single crystal X-ray diffraction (SCXRD). In addition, two other compounds, containing six fluorine atoms, three on each of the benzoyl and aniline side of the benzanilide scaffold have also been characterized through SCXRD. This current study aims to augment the capacity for hydrogen bond formation, specifically involving organic fluorine, by elevating the acidity of the involved hydrogens through the incorporation of highly electronegative fluorine atoms, in the presence of strong N-H×××O=C H-bonds. Lattice energy calculations and assessment of intermolecular interaction energies elucidate the contributions of electrostatics and dispersion forces in crystal packing. The topological analysis of the electron density is characterized by the presence of bond critical points (BCPs) involving C-H×××F and F×××F contacts, thus establishing the bonding nature of these interactions which play a crucial role in the crystal packing in addition to the presence of traditional N-H×××O=C H-bonds., (© 2024 Wiley‐VCH GmbH.)
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- 2024
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3. Harvesting Enhanced Blue Energy in Charged Nanochannels Using Semidiluted Polyelectrolyte Solution.
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Mehta SK, Padhi P, Wongwises S, and Mondal PK
- Abstract
Blue energy generation in nanochannels based on salinity gradients is currently the most promising method in the area of nonconventional energy production. We used a semidiluted pure sodium carboxymethylcellulose (NaCMC)-KCl aqueous solution to study the characteristics of blue energy generation within a charged nanochannel. We solve the corresponding equations for ionic transport using a numerical technique based on the finite element method. Our analysis focused on the electric double layer (EDL) potential field, open circuit current, diffuse potential, electric conductance, maximum generated pore power, and maximum energy conversion efficiency by varying concentrations of the salt in the left-side reservoir and the bulk polyelectrolyte. The results indicate that as the polyelectrolyte concentration increases, the extent of EDL overlap considerably reduces. With an increase in polyelectrolyte concentration, the open circuit current increases, while the diffuse potential reduces. It was observed that both electrical conductance and maximal pore power improve considerably with higher polyelectrolyte concentrations. Interestingly, our modeling framework demonstrates a power density substantially higher (up to 16.31 W/m
2 ) than earlier configurations and surpasses the established commercial limit (5 W/m2 ). Furthermore, our findings reveal that the reservoir salt concentration significantly affects the rate of decline in the maximum energy conversion efficiency as the polyelectrolyte concentration increases. The research paves the way for the development of high-power-density devices with several practical applications.- Published
- 2024
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4. Evaluating the potential of ethyl cellulose/eudragit-based griseofulvin loaded nanosponge matrix for topical antifungal drug delivery in a sustained release pattern.
- Author
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Sengupta P, Das A, Khanam J, Biswas A, Mathew J, Mondal PK, Romero EL, Thomas S, Trotta F, and Ghosal K
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- Drug Carriers chemistry, Spectroscopy, Fourier Transform Infrared, Drug Delivery Systems, Administration, Topical, Microbial Sensitivity Tests, Nanoparticles chemistry, Calorimetry, Differential Scanning, Antifungal Agents pharmacology, Antifungal Agents chemistry, Antifungal Agents administration & dosage, Griseofulvin chemistry, Griseofulvin pharmacology, Griseofulvin administration & dosage, Delayed-Action Preparations, Cellulose chemistry, Cellulose analogs & derivatives, Drug Liberation
- Abstract
Fungal infections are very alarming nowadays and are common throughout the world. Severe fungal infections may lead to a significant risk of mortality and morbidity worldwide. Sustained delivery of antifungal agents is needed to mitigate this problem. In the current study, an attempt has been made to formulate griseofulvin-loaded nanosponges using the quasi-emulsion solvent diffusion technique. For characterization, griseofulvin loaded nanosponges were tested by different instrumental techniques such as optical microscopy, scanning electron microscopy (SEM), powder X-ray diffractometer (PXRD), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). The antifungal activity of the nanosponges was assessed against Candida albican strain using the agar well-diffusion method. Finally, the drug-loaded nanosponges' in vitro sustained release activity was evaluated. FTIR spectra showed no chemical interference between the drug and polymers. Some of the peaks of the drug are not visible in the FTIR spectrum, which suggests drug entrapment. PXRD data showed that the drug lost its high crystallinity when entrapped in the nanosponge matrix. From the morphological studies via SEM and TEM, a brief idea of the surface morphology of the nanosponges was obtained. The small pores throughout the structure proved its high porosity. The antifungal sensitivity assay was successful, and a zone of inhibition was observed in all the formulations. The in-vitro drug release study showed sustained behaviour. The sustaining effect was due to the polymer and cross-linker used, which gave rise to a porous scaffold matrix. From the results, it can be concluded that griseofulvin-loaded nanosponges can be used for antifungal drug delivery against various topical skin infections., Competing Interests: Declaration of competing interest Authors declare that there is no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)
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- 2024
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5. A novel pH-sensitive method for the quantification of Ca 2+ ions by complexometric titration with Na 3 HEDTA.
- Author
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Bhochiya R, Mondal PK, and Balkrishna SJ
- Abstract
A simple and accurate complexometric titration has been developed by the reaction between Ca
2+ ions (pH 7) and Na3 HEDTA (pH 11) solutions. Formation of a Ca-EDTA complex and release of H+ ions in the system were traced by a decrease in the pH. At the equivalence point of the titration, a sharp increase in the pH was observed. Looking at the working pH range (pH 6.2-7.5) of this method, another complexometric titration method has been developed by using bromothymol blue as a pH sensitive indicator. This is the first report of a complexometric titration by using an acid base indicator.- Published
- 2024
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6. Correction: Phytoplankton nutrient dynamics and flow cytometry based population study of a eutrophic wetland habitat in eastern India, a Ramsar site.
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Singha Roy A, Gorain PC, Paul I, Sengupta S, Mondal PK, and Pal R
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[This corrects the article DOI: 10.1039/C7RA12761H.]., (This journal is © The Royal Society of Chemistry.)
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- 2024
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7. Unveiling nutrient flow-mediated stress in plant roots using an on-chip phytofluidic device.
- Author
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Agarwal K, Mehta SK, and Mondal PK
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- Nitrogen metabolism, Stress, Physiological, Microfluidic Analytical Techniques instrumentation, Plant Roots metabolism, Lab-On-A-Chip Devices, Nutrients metabolism
- Abstract
The initial emergence of the primary root from a germinating seed is a pivotal phase that influences a plant's survival. Abiotic factors such as pH, nutrient availability, and soil composition significantly affect root morphology and architecture. Of particular interest is the impact of nutrient flow on thigmomorphogenesis, a response to mechanical stimulation in early root growth, which remains largely unexplored. This study explores the intricate factors influencing early root system development, with a focus on the cooperative correlation between nutrient uptake and its flow dynamics. Using a physiologically as well as ecologically relevant, portable, and cost-effective microfluidic system for the controlled fluid environments offering hydraulic conductivity comparable to that of the soil, this study analyzes the interplay between nutrient flow and root growth post-germination. Emphasizing the relationship between root growth and nitrogen uptake, the findings reveal that nutrient flow significantly influences early root morphology, leading to increased length and improved nutrient uptake, varying with the flow rate. The experimental findings are supported by mechanical and plant stress-related fluid flow-root interaction simulations and quantitative determination of nitrogen uptake using the total Kjeldahl nitrogen (TKN) method. The microfluidic approach offers novel insights into plant root dynamics under controlled flow conditions, filling a critical research gap. By providing a high-resolution platform, this study contributes to the understanding of how fluid-flow-assisted nutrient uptake and pressure affect root cell behavior, which, in turn, induces mechanical stress leading to thigmomorphogenesis. The findings hold implications for comprehending root responses to changing environmental conditions, paving the way for innovative agricultural and environmental management strategies.
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- 2024
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8. Assessment of mental well-being and its socio-economic determinants among older adults in the Rohingya refugee camp of Bangladesh.
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Anwar A, Akter N, Yadav UN, Ghimire S, Bhattacharjee S, Eusufzai SZ, Mahumud RA, Ali ARMM, Huda MN, Majumder MSI, Zahid A, Mondal PK, Rizwan AAM, Shuvo SD, Rosenbaum S, and Mistry SK
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- Humans, Bangladesh epidemiology, Male, Female, Aged, Middle Aged, Cross-Sectional Studies, Aged, 80 and over, Mental Health, Refugee Camps, Refugees psychology, Socioeconomic Factors
- Abstract
Older adults residing in refugee settlements with unhealthy living environments, inadequate access to health care services, and limited psychosocial support are vulnerable to experience mental health problems jeopardizing their mental well-being. The present study aims to explore the mental well-being status and its socio-economic determinants among the older adults living in the Rohingya refugee camp in Bangladesh. This cross-sectional study was conducted among adults aged ≥ 60 residing in five sub-camps within the Rohingya refugee camp of Cox's Bazar, Bangladesh. Data were collected through face-to-face interviews conducted between November and December 2021. The 14-item Warwick-Edinburgh Mental Well-being Scale was used to assess mental well-being. A cumulated score was derived using the scale ranging from 14 to 70, with higher scores indicating greater levels of mental well-being. A generalized linear regression model was used to examine the socio-economic factors associated with the mental well-being of older adults. A total of 864 older adults participated in the study having a mean mental well-being score of 45.4. Regression analysis revealed that the difference in the logs of mental well-being score was expected to be significantly lower among participants aged 70-79 years (β: - 1.661; 95% CI: - 2.750 to - 0.572; p = 0.003), aged ≥ 80 years (β: - 3.198; 95% CI: - 5.114 to - 1.282; p = 0.001), and those with any non-communicable chronic conditions (β: - 2.903; 95% CI: - 3.833 to - 1.974; p < 0.001) when compared to their counterparts. Conversely, the difference in the logs of mental well-being score was expected to be significantly higher among individuals with formal schooling (β: 3.370, 95% CI: 1.855 to 4.886, p < 0.001) and those having additional income besides aid (β: 1.629; 95% CI: 0.642 to 2.615; p = 0.001), compared to their respective counterparts. Our findings highlight the need to provide psychosocial assistance to older individuals, particularly those who live in large families, suffer from chronic diseases, and live in socio-economic deprivation., (© 2024. The Author(s).)
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- 2024
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9. A novel syphilis Treponema pallidum lipoprotein peptide antigen diagnostic assay using red cell kodecytes in routine blood centre column agglutination testing platforms.
- Author
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Datta SS, Nagappan R, Biswas D, Basu D, Gupta K, Mondal PK, Tuzikov A, Bovin NV, and Henry SM
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- Humans, Erythrocytes microbiology, Agglutination Tests methods, Syphilis Serodiagnosis methods, Antibodies, Bacterial blood, Treponema pallidum immunology, Syphilis diagnosis, Syphilis blood, Lipoproteins immunology, Antigens, Bacterial immunology
- Abstract
Background and Objectives: The detection of treponemal antibodies, which are used to make a diagnosis of syphilis, is important both for diagnostic purposes and as a mandatory blood donor test in most countries. We evaluated the feasibility of using Kode Technology to make syphilis peptide red cell kodecytes for use in column agglutination serologic platforms., Materials and Methods: Candidate Kode Technology function-spacer-lipid (FSL) constructs were made for the Treponema pallidum lipoprotein (TmpA) of T. pallidum, using the peptide and FSL selection algorithms, and then used to make kodecytes. Developmental kodecytes were evaluated against a large range of syphilis antibody reactive and non-reactive samples in column agglutination platforms and compared against established methodologies. Overall, 150 reactive and 2072 non-reactive Syphicheck assay (a modified T. pallidum particle agglutination) blood donor samples were used to evaluate the agreement rate of the developed kodecyte assay., Results: From three FSL-peptide candidate constructs, one was found to be the most suitable for diagnostics. Of 150 Syphicheck assay reactive samples, 146 were TmpA-kodecyte reactive (97.3% agreement), compared with 58.0% with the rapid plasmin reagin (RPR) assay for the same samples. Against the 2072 expected syphilis non-reactive samples the agreement rate for TmpA-kodecytes was 98.8%., Conclusion: TmpA-kodecytes are viable for use as cost-effective serologic reagent red cells for the detection of treponemal antibodies to diagnose syphilis with a high level of specificity in blood centres. This kodecyte methodology also potentially allows for introduction of the reverse-algorithm testing into low-volume laboratories, by utilizing existing transfusion laboratory infrastructure., (© 2024 The Authors. Vox Sanguinis published by John Wiley & Sons Ltd on behalf of International Society of Blood Transfusion.)
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- 2024
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10. Maximizing blue energy: the role of ion partitioning in nanochannel systems.
- Author
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Mehta SK, Deb D, Nandy A, Shen AQ, and Mondal PK
- Abstract
This study describes a numerical analysis on blue energy generation using a charged nanochannel with an integrated pH-sensitive polyelectrolyte layer (PEL), considering ion partitioning effects due to permittivity differences. The mathematical model for ionic and fluidic transport is solved using the finite element method, and the model validation is performed against existing theoretical and experimental results. The study investigates the influence of electrolyte concentration, permittivity ratio, and salt types (KCl, BeCl
2 , AlCl3 ) on the energy conversion process. The findings illustrate the substantial role of ion partitioning in modulating ionic concentration and potential fields, thereby affecting current profiles and energy conversion efficiencies. Remarkably, overlooking ion partitioning leads to significant overestimations of power density, highlighting the necessity of this consideration for accurate device performance predictions. This work introduces a promising configuration that achieves higher power densities, paving the way for the next generation of efficient energy-harvesting devices. The findings offer valuable insights into the development of state-of-the-art blue energy harvesting nanofluidic devices, advancing sustainable energy production.- Published
- 2024
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11. One-Step Catalyst-Transfer Macrocyclization: Expanding the Chemical Space of Azaparacyclophanes.
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Ayuso-Carrillo J, Fina F, Galleposo EC, Ferreira RR, Mondal PK, Ward BD, and Bonifazi D
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In this paper, we report on a one-step catalyst-transfer macrocyclization (CTM) reaction, based on the Pd-catalyzed Buchwald-Hartwig cross-coupling reaction, selectively affording only cyclic structures. This route offers a versatile and efficient approach to synthesize aza[1
n ]paracyclophanes (APCs) featuring diverse functionalities and lumens. The method operates at mild reaction temperatures (40 °C) and short reaction times (∼2 h), delivering excellent isolated yields (>75% macrocycles) and up to 30% of a 6-membered cyclophane, all under nonhigh-dilution concentrations (35-350 mM). Structural insights into APCs reveal variations in product distribution based on different endocyclic substituents, with steric properties of exocyclic substituents having minimal influence on the macrocyclization. Aryl-type endocyclic substituents predominantly yield 6-membered macrocycles, while polycyclic aromatic units such as fluorene and carbazole favor 4-membered species. Experimental and computational studies support a proposed mechanism of ring-walking catalyst transfer that promotes the macrocycle formation. It has been found that the macrocyclization is driven by the formation of cyclic conformers during the oligomerization step favoring an intramolecular C-N bond formation that, depending on the cycle size, hinges on either preorganization effect or kinetic increase of the reductive elimination step or a combination of the two. The CTM process exhibits a "living" behavior, facilitating sequential synthesis of other macrocycles by introducing relevant monomers, thus providing a practical synthetic platform for chemical libraries. Notably, CTM operates both under diluted and concentrated regimes, offering scalability potential, unlike typical macrocyclization reactions usually operating in the 0.1-1 mM range.- Published
- 2024
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12. A nine-ring fused terrylene diimide exhibits switching between red TADF and near-IR room temperature phosphorescence.
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Jha S, Mehra KS, Dey M, S S, Ghosh D, Mondal PK, Polentarutti M, and Sankar J
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Herein, we report the first example of a terrylene diimide derivative that switches emission between thermally activated delayed fluorescence (TADF) and room temperature phosphorescence (RTP) in the red region. By design, the molecule TDI-cDBT boasts a symmetrical, consecutively fused nine-ring motif with a kite-like structure. The rigid core formed by the annulated dibenzothiophene moiety favoured efficient intersystem crossing and yielded a narrow-band emission with a full-width half maxima (FWHM) of 0.09 eV, along with high colour purity. A small Δ E
S of 0.04 eV facilitated thermally activated delayed fluorescence, enhancing the quantum yield to 88% in the red region. Additionally, it also prefers a direct triplet emission from the aggregated state. The room temperature phosphorescence observed from the aggregates has a longer emission lifetime of 1.8 ms, which is further prolonged to 8 ms at 77 K in the NIR region. Thus, the current strategy is successful in not only reducing Δ E1 -T1 S to favour TADF but also serves as a novel platform that can switch emission from TADF to RTP depending upon the concentration., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)1 -T1 - Published
- 2024
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13. Reutilization of ferro-arsenic waste sludge for the development of concrete blocks through solidification: conservation of natural aggregates with policy suggestion.
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Ruj B, Nayak J, Debbarma SR, Mondal PK, Bishayee B, Chatterjee RP, and Chakrabortty S
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- Compressive Strength, Construction Materials, Sewage, Arsenic, Iron chemistry
- Abstract
In the present study, arsenic sludge and iron sludge extracted from a laboratory scale water treatment plant were aimed to reutilize for the development of concrete blocks. Three different grades (M15, M20 and M25) of concrete blocks were made by blending of arsenic sludge and improved iron sludge (50% sand and 40% iron sludge) in the range of density of 425 to 535 kg/m3 at an optimum ratio of 10:90 (arsenic: iron sludge) followed by mixing of designed quantity cement, coarse aggregates, water and additives. Concrete blocks developed based on this such combination exhibited 26 MPa, 32 MPa and 41 MPa compressive strengths, and 4.68 MPa, 5.92 MPa and 7.78 MPa tensile strengths for M15, M20 and M25, respectively. In comparison with the developed concrete blocks and the blocks made with 10% arsenic sludge and 90% fresh sand, the developed ones (employing 50% sand, 40% iron sludge and 10% arsenic sludge) showed more than 200% higher strength perseverance on average. Successful Toxicity Characteristic Leaching Procedure (TCLP) and compressive strength of the sludge-fixed concrete cubes classified it as a non-hazardous and completely safe to use value-added material. This process involves stabilization of arsenic-rich sludge generated from high-volume long-run laboratory-based arsenic-iron abatement set-up from contaminated water with successful fixation in solid matrix of concrete through complete substitution of natural fine aggregates (river sand) in cement mixture. Techno-economic assessment reveals such concrete block preparation at $0.09 each which is lesser than 1/2 of the present market price of same quality concrete block in India.
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- 2024
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14. A thiolated copper-hydride nanocluster with chloride bridging as a catalyst for carbonylative C-N coupling of aryl amines under mild conditions: a combined experimental and theoretical study.
- Author
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Das AK, Biswas S, Pal A, Manna SS, Sardar A, Mondal PK, Sahoo B, Pathak B, and Mandal S
- Abstract
Atomically precise copper nanoclusters (Cu NCs), an emerging class of nanomaterials, have garnered significant attention owing to their versatile core-shell architecture and their potential applications in catalytic reactions. In this study, we present a straightforward synthesis strategy for [Cu
29 (St Bu)12 (PPh3 )4 Cl6 H10 ][BF4 ] (Cu29 ) NCs and explore their catalytic activity in the carbonylative C-N coupling reaction involving aromatic amines and N-heteroarenes with dialkyl azodicarboxylates. Through a combination of experimental investigations and density functional theory studies, we elucidate the radical mechanisms at play. The crucial step in the catalytic process is identified as the decomposition of diisopropyl azodicarboxylates on the surface of Cu29 NCs, leading to the generation of oxyacyl radicals and the liberation of nitrogen gas. Subsequently, an oxyacyl radical abstracts a hydrogen atom from aniline, initiating the formation of an aminyl radical. Finally, the aminyl radical reacts with another oxyacyl radical, culminating in the synthesis of the desired carbamate product. This detailed analysis provides insights into the intricate catalytic pathways of Cu29 NCs, shedding light on their potential for catalyzing carbonylative C-N coupling reactions.- Published
- 2024
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15. Modulation of Singlet-Triplet Gap in Atomically Precise Silver Cluster-Assembled Material.
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Chandrashekar P, Sardar G, Sengupta T, Reber AC, Mondal PK, Kabra D, Khanna SN, Deria P, and Mandal S
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Silver cluster-based solids have garnered considerable attention owing to their tunable luminescence behavior. While surface modification has enabled the construction of stable silver clusters, controlling interactions among clusters at the molecular level has been challenging due to their tendency to aggregate. Judicious choice of stabilizing ligands becomes pivotal in crafting a desired assembly. However, detailed photophysical behavior as a function of their cluster packing remained unexplored. Here, we modulate the packing pattern of Ag
12 clusters by varying the nitrogen-based ligand. CAM-1 formed through coordination of the tritopic linker molecule and NC-1 with monodentate pyridine ligand; established via non-covalent interactions. Both the assemblies show ligand-to-metal-metal charge transfer (LMMCT) based cluster-centered emission band(s). Temperature-dependent photoluminescence spectra exhibit blue shifts at higher temperatures, which is attributed to the extent of the thermal reverse population of the S1 state from the closely spaced T1 state. The difference in the energy gap (ΔEST ) dictated by their assemblies played a pivotal role in the way that Ag12 cluster assembly in CAM-1 manifests a wider ΔEST and thus requires higher temperatures for reverse intersystem crossing (RISC) than assembly of NC-1. Such assembly-defined photoluminescence properties underscore the potential toolkit to design new cluster- assemblies with tailored optoelectronic properties., (© 2023 Wiley-VCH GmbH.)- Published
- 2024
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16. Promotion of livelihood opportunities to address food insecurity in Rohingya refugee camps of Bangladesh.
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Anwar A, Ali AM, Yadav UN, Huda MN, Rizwan AAM, Parray AA, Sarma H, Halima O, Saha N, Shuvo SD, Mondal PK, Shamim AA, and Mistry SK
- Subjects
- Humans, Bangladesh, Refugee Camps, Refugees, Malnutrition
- Abstract
The world is facing a tremendous problem in the form of food insecurity that is posing a great challenge to achieving sustainable development goal 2 of creating a hunger-free world. Refugees and displaced populations are particularly vulnerable to food insecurity and malnutrition, who lack any productive assets and depend on aid. Rohingya refugees, displaced from Myanmar and took refuge in Cox's Bazar, Bangladesh, live in a crowded unhealthy environment and are severely vulnerable to food insecurity and malnutrition. In our recent study, we found that only 21.6% of the households in Rohingya refugee camps had acceptable food security status. Interestingly, this study further revealed that acceptable food security status was significantly higher among the households that had some additional income aside from aid, compared to those relying on aid alone. This shows the importance of promoting livelihood opportunities to improve food security status among the camp dwellers. In this paper, we presented our views on promoting livelihood opportunities to address the overwhelming food insecurity crisis among the Rohingya refugees in Bangladesh.
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- 2024
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17. AC Electrothermal Effect Promotes Enhanced Solute Mixing in a Wavy Microchannel.
- Author
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Mehta SK and Mondal PK
- Abstract
For liquids used in biological applications, a smaller diffusion coefficient results in a longer mixing time. We discuss, in this endeavor, the promising potential of the AC electrothermal (ACET) effect toward modulating enhanced mixing of electrolytic liquids with higher convective strength in a novel wavy micromixer. To this end, we develop a modeling framework and numerically solve the pertinent transport equations in a three-dimensional (3D) configuration numerically. By benchmarking the developed modeling framework with the experimental results available in this paradigm, we aptly demonstrate the maximum temperature rise, flow topology, species concentration field, and mixing efficiency in the proposed configuration for a set of parameters pertinent to this analysis. We find that the maximum temperature increase in the wavy micromixer, owing to the electrothermal effect, is less than 10 K even for the higher strength of the applied voltage, implying nondegradation of biological substances within the liquid sample. We report that the formation of significant lateral flow closer to the electrodes leads to a highly three-dimensional ACET flow field, which has a significant impact on the mixing efficiency for the range of diffusive Peclet numbers considered. We also report that the wave amplitude of the mixer, when intervening with the diffusive Peclet number, strongly impacts the mixing efficiency. As witnessed in this endeavor, for the smaller diffusive Peclet number, the mixing efficiency increases with amplitude, while the effect becomes the opposite for the higher Peclet number. The results of this study seem to provide an adequate basis for the design of a novel micromixer intended for enhanced solute mixing in realistic microfluidic applications.
- Published
- 2023
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18. Vortex-assisted electroosmotic mixing of Carreau fluid in a microchannel.
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Mehta SK and Mondal PK
- Subjects
- Rheology methods, Kinetics, Motion, Electroosmosis
- Abstract
Pertaining to the mixing of the non-Newtonian Carreau fluid under electrokinetic actuation inside a plane microchannel, we propose a new design of micromixer that involves inserting a two-part cylinder bearing zeta potential of the same sign but different magnitude in the upstream and downstream directions. We numerically solve the transport equations to predict the underlying mixing characteristics. We demonstrate that a substantial momentum difference between the microchannel's plane wall and cylinder leads to the development of a vortex in the flow pathway, which in turn, enhances mixing substantially. As shown, for a fluid having a highly shear-thinning nature, the vortex-assisted convection mixing strength increases with diffusivity of the candidate fluids. Moreover, it is shown that for the higher shear-thinning nature of the candidate fluid, an increase in cylinder radius enhances mixing efficiency and flow rate simultaneously, resulting in a "quick and efficient" mixing condition. Additionally, the fluid rheology significantly alters the kinetics of shear-induced binary aggregation. Our findings show that the shear-induced aggregation characteristic time sharply increases with increasing shear-thinning behavior of the fluid., (© 2023 Wiley-VCH GmbH.)
- Published
- 2023
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19. Dielectric polarization-mediated efficient solute mixing: Effect of the geometrical configuration of polarizing blocks.
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Pandey D, Mondal PK, and Wongwises S
- Subjects
- Solutions, Microfluidics methods, Electricity
- Abstract
We propose a novel technique, consistent with the induced charge electrokinetic (ICEK) phenomenon, for the efficient mixing of solute species at a microfluidic scale. A nonuniform bipolar electric double layer develops in the presence of an external electric field over a polarizable object is better known as the ICEK phenomenon. This ICEK is one of the most favorable techniques preferred for enhanced solute mixing in on-chip microfluidic platforms. In the purview of the ICEK phenomenon, instead of using perfectly conducting polarizable objects, for the first time in this study, we employ polarizable dielectric objects of different sizes and shapes for efficient mixing of solute species. We show that different types of vortices developed in the flow pathway adjacent to the polarizable dielectric blocks help in yielding efficient mixing in the proposed configuration. The novelty of our work is embellished in two different perspectives, that is, first, concentrating on the influences of the physical properties of the polarizable dielectric block on the underlying mixing, and, second, focusing on their sizes, shapes, and the arrangements in tuning the underlying mixing phenomena., (© 2023 Wiley-VCH GmbH.)
- Published
- 2023
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20. Salinity Gradient-Induced Power Generation in Nanochannels: The Role of pH-Sensitive Polyelectrolyte Layers.
- Author
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Mehta SK, Raj AR, and Mondal PK
- Abstract
By varying the pH values (pH
R ) and types of salt solution, we investigate the salinity gradient-induced electrical and mechanical flow energies inside a reservoir-connected charged nanochannel with a grafted pH-sensitive polyelectrolyte layer (PEL) on the inner surfaces. The aqueous solutions of KCl, LiCl, BaCl2 , BeCl2 , AlCl3 , and Co(en)3 Cl3 salts are used as the working fluid in the current investigation. We examine the associated ionic transport and flow field, aiming to understand the underlying physics behind the generation of electrical and hydraulic energy through alterations in pHR and types of salt solution. Our results reveal that the PEL space charge density decreases with increasing pHR at lower values, while it remains almost insensitive to higher pHR values. The electrical conductance and maximum pore power of the Co(en)3 Cl3 solution are significantly higher compared to salts with monovalent and divalent cations. Furthermore, the magnitude of these two parameters decreases with lower pHR and becomes insensitive to higher pHR values. The results illustrate that the maximum electrical energy conversion efficiency enhances with pHR , reaching its highest level for the Co(en)3 Cl3 solution. We expect that the findings of the current work will have a significant bearing on the design and development of a state-of-the-art salinity gradient-based energy convertor as a potential candidate for renewable energy sources.- Published
- 2023
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21. Anxiety and Stress Related to COVID-19 Among the Community Dwelling Older Adults Residing in the Largest Refugee Camp of the World.
- Author
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Anwar A, Yadav UN, Huda MN, Das S, Rosenbaum S, Ali ARMM, Mondal PK, Rizwan AAM, Hossain SFA, Das Shuvo S, and Mistry SK
- Subjects
- Humans, Aged, Cross-Sectional Studies, Pandemics, Refugee Camps, Anxiety epidemiology, Independent Living, COVID-19 epidemiology
- Abstract
The current cross-sectional study was conducted among 864 older adults aged ≥ 60 years residing in Rohingya refugee camp through face-to-face interviews during November-December 2021. COVID-19-related anxiety was measured using the five-point Coronavirus Anxiety Scale (CAS) and perceived stress using the 10-point Perceived Stress Scale (PSS). The linear regression model identified the factors associated with COVID-19-related anxiety and perceived stress. The prevalence of COVID-19-related anxiety and perceived stress was 68% and 93%, respectively. The average COVID-19-related anxiety score expected to be significantly higher among those who were physically inactive, concerned about COVID-19, had a close friend/family member diagnosed with COVID-19, and had some difficulty in getting food and routine medical care during the COVID-19 pandemic. Meanwhile, the average perceived stress score was expected to be significantly higher among those without partners, who were feeling overwhelmed by COVID-19, and who experienced COVID-19-related anxiety during the pandemic. The findings suggest providing immediate psychosocial support to older Rohingya adults., (© 2023. The Author(s).)
- Published
- 2023
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22. Prevalence and determinants of self-reported functional status among older adults residing in the largest refugee camp of the world.
- Author
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Anwar A, Yadav UN, Huda MN, Rifat MA, Ali AM, Mondal PK, Rizwan AAM, Shuvo SD, and Mistry SK
- Subjects
- Humans, Male, Female, Aged, Self Report, Prevalence, Cross-Sectional Studies, Functional Status, Refugee Camps, Refugees
- Abstract
Background: The older adults of refugee camps might be vulnerable to exhibiting limited functional abilities because of the limited resources available to create a supportive environment for older population in the camps. This study aims to explore the prevalence and determinants of self-reported functional status among the older adults residing in the Rohingya refugee camp in Bangladesh., Methods: This cross-sectional study was conducted on 864 older adults aged 60 years and above living in five selected sub-camps of Rohingya refugee camp in Cox's Bazar, Bangladesh. Data were collected through face-to-face interviews of the participants between November-December 2021. Functional status was measured using the Barthel Index. Information on participants' sociodemographic characteristics, self-reported chronic diseases and lifestyle characteristics were also collected. A multiple logistic regression model was used to assess the factors associated with self-reported functional abilities among the participants., Results: The overall percentage of people having limited self-reported functional ability was 26.5% (male: 22.6% and female: 31.5%) with inability most found in grooming (33.2%), bathing (31.8%), stair using (13.2%) and mobility (10.7%). In the final adjusted model, having age of 80 years or more (aOR = 2.01,95% CI: 1.08,3.75), being female (aOR = 1.44, 95% CI: 1.04,2.0), having low memory or concentration (aOR = 1.83, 95% CI: 1.30,2.56), loneliness (aOR = 2.89, 95% CI:1.74,4.80) and living with aid alone (aOR = 2.89, 95% CI: 1.74,4.80) were found to be associated with self-reported limited functional ability., Conclusion: The findings of this study highlight the need for attention from policymakers and public health practitioners on addressing functional limitations among older adults residing in the Rohingya refugee camp. Our findings emphasize the need for the development of comprehensive interventions that can address the wider unmet needs (e.g., ensuring family/caregiver support, engaging in social and physical activities, providing nutritional support packages, etc.) to improve the health and well-being of older Rohingya adults., (© 2023. The Author(s).)
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- 2023
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23. Luminescent [CO 2 @Ag 20 (SAdm) 10 (CF 3 COO) 10 (DMA) 2 ] nanocluster: synthetic strategy and its implication towards white light emission.
- Author
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Biswas S, Das AK, Sardar A, Manna SS, Mondal PK, Polentarutti M, Pathak B, and Mandal S
- Abstract
Owing to the quantized size and associated discrete energy levels, atomically precise silver nanoclusters (Ag NCs) hold great potential for designing functional luminescent materials. However, the thermally activated non-radiative transition of Ag(I)-based NCs has faded the opportunities. To acquire the structurally rigid architecture of cluster nodes for constraining such transitions, a new synthetic approach is unveiled here that utilizes a neutral template as a cluster-directing agent to assemble twenty Ag(I) atoms that ensure the maximum number of surface-protecting ligand attachment possibilities in a particular solvent medium. The solvent polarity triggers the precise structural design to circumvent the over-reliance of the templates, which results in the formation of [CO
2 @Ag20 (SAdm)10 (CF3 COO)10 (DMA)2 ] NC (where SAdm = 1-adamantanethiolate and DMA = N , N -dimethylacetamide) exhibiting an unprecedented room-temperature photoluminescence emission. The high quantum yield of the generated blue emission ensures its candidature as an ideal donor for artificial light-harvesting system design, and it is utilized with the two-step sequential energy transfer process, which finally results in the generation of ideal white light. For implementing perfect white light emission, the required chromophores in the green and red emission regions were chosen based on their effective spectral overlap with the donor components. Due to their favorable energy-level distribution, excited state energy transfers occurred from the NC to β-carotene at the initial step, then from the conjugate of the NC and β-carotene to another chromophore, Nile Blue, at the second step via a sequential Förster resonance energy transfer pathway.- Published
- 2023
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24. Chemiosomotic flow in a soft conical nanopore: harvesting enhanced blue energy.
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Pandey D, Mondal PK, and Wongwises S
- Abstract
The salinity gradient energy or the 'blue energy' is one of the most promising inexpensive and abundant sources of clean energy, having immense capabilities to serve modern-day society. In this article, we overlay an extensive analysis of reverse electrodialysis (RED) for harvesting salinity gradient energy in a single conical nanochannel, grafted with a pH-tunable polyelectrolyte layer (PEL) on the inner surfaces. We primarily focus on the distinctiveness of the solution pH of the connecting reservoirs. In spite of acquiring a maximum power density of ∼1.2 kW m
-2 in the chosen configuration, we notice a counter-intuitive patterning of the ion transport for a certain span of pH, leading to diminishing power. To this end, we discuss the possible strategic avenues essentially to achieve a higher amount of power density. In order to achieve a desirable outcome within that pH zone, we employ two separate approaches intending to counter the underlying physics. Results reveal a great enhancement in the power density as well as in the efficiency even under the framework of both strategies proposed herein. Moreover, as shown, the window of solution pH has increased by three times, implicating the maximum power density mentioned above. We expect that the strategic procedure of augmented energy harvesting as discussed in this analysis can be of importance from the perspective of fabricating state-of-the-art nanodevices aimed at blue energy harvesting.- Published
- 2023
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25. Predicting Childhood Obesity Based on Single and Multiple Well-Child Visit Data Using Machine Learning Classifiers.
- Author
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Mondal PK, Foysal KH, Norman BA, and Gittner LS
- Subjects
- Child, Humans, United States, Body Mass Index, Overweight, Risk Factors, Machine Learning, Pediatric Obesity diagnosis, Pediatric Obesity epidemiology
- Abstract
Childhood obesity is a public health concern in the United States. Consequences of childhood obesity include metabolic disease and heart, lung, kidney, and other health-related comorbidities. Therefore, the early determination of obesity risk is needed and predicting the trend of a child's body mass index (BMI) at an early age is crucial. Early identification of obesity can lead to early prevention. Multiple methods have been tested and evaluated to assess obesity trends in children. Available growth charts help determine a child's current obesity level but do not predict future obesity risk. The present methods of predicting obesity include regression analysis and machine learning-based classifications and risk factor (threshold)-based categorizations based on specific criteria. All the present techniques, especially current machine learning-based methods, require longitudinal data and information on a large number of variables related to a child's growth (e.g., socioeconomic, family-related factors) in order to predict future obesity-risk. In this paper, we propose three different techniques for three different scenarios to predict childhood obesity based on machine learning approaches and apply them to real data. Our proposed methods predict obesity for children at five years of age using the following three data sets: (1) a single well-child visit, (2) multiple well-child visits under the age of two, and (3) multiple random well-child visits under the age of five. Our models are especially important for situations where only the current patient information is available rather than having multiple data points from regular spaced well-child visits. Our models predict obesity using basic information such as birth BMI, gestational age, BMI measures from well-child visits, and gender. Our models can predict a child's obesity category (normal, overweight, or obese) at five years of age with an accuracy of 89%, 77%, and 89%, for the three application scenarios, respectively. Therefore, our proposed models can assist healthcare professionals by acting as a decision support tool to aid in predicting childhood obesity early in order to reduce obesity-related complications, and in turn, improve healthcare.
- Published
- 2023
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26. Influence of viscoelectric effect on diffusioosmotic transport in nanochannel.
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Mehta SK and Mondal PK
- Subjects
- Electroosmosis methods, Electricity
- Abstract
We have investigated the role of viscoelectric effect on diffusioosmotic flow (DOF) through a nanochannel connected with two reservoirs. The transport equations governing the flow dynamics are solved numerically using the finite element technique. We have extensively analyzed the variation of induced field due to electric double layer (EDL) phenomenon, relative viscosity as modulated by the viscoelectric effect as well as reservoir's concentration difference, and their eventual impact on the underlying flow characteristics. It is revealed that the induced electric field in the EDL enhances fluid viscosity substantially near the charged wall at a higher concentration. We have shown that neglecting viscoelectric effect in the paradigm of diffusioosmotic transport overestimates the net throughput, particularly at a higher concentration difference. Furthermore, we show that pertaining to chemiosmosis dominated regime, the average flow velocity modifies with the increase in concentration difference up to a critical value. In comparison, the rise in the strength of resistive electroosmotic actuation by the accumulation of anions in the upstream reservoir reduces the average flow velocity at a higher concentration difference. We have reported a reduction in critical concentration with the increase in viscoelectric effect. The inferences of this analysis are deemed pertinent to reveal the bearing of viscoelectric effect as a flow control mechanism pertaining to DOF at nanoscale., (© 2022 Wiley-VCH GmbH.)
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- 2023
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27. RAV1 mediates cytokinin signaling for regulating primary root growth in Arabidopsis.
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Mandal D, Datta S, Raveendar G, Mondal PK, and Nag Chaudhuri R
- Subjects
- Plant Roots metabolism, Gene Expression Regulation, Plant, Cytokinins metabolism, Meristem, Indoleacetic Acids metabolism, DNA-Binding Proteins genetics, Nuclear Proteins metabolism, Arabidopsis metabolism, Arabidopsis Proteins metabolism
- Abstract
Root growth dynamics is an outcome of complex hormonal crosstalk. The primary root meristem size, for example, is determined by antagonizing actions of cytokinin and auxin. Here we show that RAV1, a member of the AP2/ERF family of transcription factors, mediates cytokinin signaling in roots to regulate meristem size. The rav1 mutants have prominently longer primary roots, with a meristem that is significantly enlarged and contains higher cell numbers, compared with wild-type. The mutant phenotype could be restored on exogenous cytokinin application or by inhibiting auxin transport. At the transcript level, primary cytokinin-responsive genes like ARR1, ARR12 were significantly downregulated in the mutant root, indicating impaired cytokinin signaling. In concurrence, cytokinin induced regulation of SHY2, an Aux/IAA gene, and auxin efflux carrier PIN1 was hindered in rav1, leading to altered auxin transport and distribution. This effectively altered root meristem size in the mutant. Notably, CRF1, another member of the AP2/ERF family implicated in cytokinin signaling, is transcriptionally repressed by RAV1 to promote cytokinin response in roots. Further associating RAV1 with cytokinin signaling, our results demonstrate that cytokinin upregulates RAV1 expression through ARR1, during post-embryonic root development. Regulation of RAV1 expression is a part of secondary cytokinin response that eventually represses CRF1 to augment cytokinin signaling. To conclude, RAV1 functions in a branch pathway downstream to ARR1 that regulates CRF1 expression to enhance cytokinin action during primary root development in Arabidopsis., (© 2022 Society for Experimental Biology and John Wiley & Sons Ltd.)
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- 2023
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28. Leveraging spreadsheet analysis tool for electrically actuated start-up flow of non-Newtonian fluid in small-scale systems.
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Roy M, Chakraborty P, Mondal PK, and Wongwises S
- Abstract
In this article, we demonstrate the solution methodology of start-up electrokinetic flow of non-Newtonian fluids in a microfluidic channel having square cross-section using Spreadsheet analysis tool. In order to incorporate the rheology of the non-Newtonian fluids, we take into consideration the Ostwald-de Waele power law model. By making a comprehensive discussion on the implementation details of the discretized form of the transport equations in Spreadsheet analysis tool, and establishing the analytical solution for a special case of the start-up flow, we compare the results both during initial transience as well as in case of steady-state scenario. Also, to substantiate the efficacy of the proposed spreadsheet analysis in addressing the detailed flow physics of rheological fluids, we verify the results for several cases with the corresponding numerical results. It is found that the solution obtained from the Spreadsheet analysis is in good agreement with the numerical results-a finding supporting spreadsheet analysis's suitability for capturing the fine details of microscale flows. We strongly believe that our analysis study will open up a new research scope in simulating microscale transport process of non-Newtonian fluids in the framework of cost-effective and non-time consuming manner., (© 2022. The Author(s).)
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- 2022
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29. DNA methylome in pancreatic cancer identified novel promoter hyper-methylation in NPY and FAIM2 genes associated with poor prognosis in Indian patient cohort.
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Chatterjee A, Bararia A, Ganguly D, Mondal PK, Roy P, Banerjee S, Ghosh S, Gulati S, Ghatak S, Chattopadhay BK, Basu P, Chatterjee A, and Sikdar N
- Abstract
Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the leading cancers worldwide and has a poor survival, with a 5-year survival rate of only 8.5%. In this study we investigated altered DNA methylation associated with PDAC severity and prognosis., Methods: Methylome data, generated using 450 K bead array, was compared between paired PDAC and normal samples in the TCGA cohort (n = 9) and our Indian cohort (n = 7). The total Indian Cohort (n = 75) was split into cohort 1 (n = 7), cohort 2 (n = 22), cohort 3 (n = 26) and cohort 4 (n = 20).Validation of differential methylation (6 selected CpG loci) and associated gene expression for differentially methylated genes (10 selected gDMs) were carried out in separate validation cohorts, using MSP, RT-PCR and IHC correlations between methylation and gene expression were observed in TCGA, GTEx cohorts and in validation cohorts. Kaplan-Meier survival analysis was done to study differential prognosis, during 2-5 years of follow-up., Results: We identified 156 DMPs, mapped to 91 genes (gDMs), in PDAC; 68 (43.5%) DMPs were found to be differentially methylated both in TCGA cohort and our cohort, with significant concordance at hypo- and hyper-methylated loci. Enrichments of "regulation of ion transport", "Interferon alpha/beta signalling", "morphogenesis and development" and "transcriptional dysregulation" pathways were observed among 91 gDMs. Hyper-methylation of NPY and FAIM2 genes with down-regulated expression in PDAC, were significantly associated with poor prognosis in the Indian patient cohort., Conclusions: Ethnic variations among populations may determine the altered epigenetic landscape in the PDAC patients of the Indian cohort. Our study identified novel differentially methylated genes (mainly NPY and FAIM2) and also validated the previously identified differentially methylated CpG sites associated with PDAC cancer patient's survival. Comparative analysis of our data with TCGA and CPTAC cohorts showed that both NPY and FAIM2 hyper-methylation and down-regulations can be novel epigenetically regulated genes in the Indian patient population, statistically significantly associated with poor survival and advanced tumour stages., (© 2022. The Author(s).)
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- 2022
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30. Ultrasensitive colorimetric detection of fluoride and arsenate in water and mammalian cells using recyclable metal oxacalixarene probe: a lateral flow assay.
- Author
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Dey S, Kumar A, Mondal PK, Chopra D, Roy R, Jindani S, Ganguly B, Mayya C, Bhatia D, and Jain VK
- Subjects
- Aluminum, Arsenates, Colorimetry methods, Fluorides, Humans, Mouthwashes, Toothpastes, Water chemistry, Arsenic, Nucleic Acids
- Abstract
Globally 3 billion people are consuming water with moderately high concentrations of fluoride and arsenic. The development of a simple point of care (PoC) device or home device for the detection of fluoride/arsenic ensures safety before consuming water. Till date, lateral flow assay (LFA) based PoC devices can detect nucleic acids, viruses and diseases. An aluminium complex of rhodamine B functionalized oxacalix[4]arene (L) was designed to execute the LFA-based PoC device. Initially, Al
3+ and Fe3+ ions were involved in complexation with the rhodamine B functionalized oxacalix[4]arene (L), resulting C1 (L-Al3+ ) and C2 (L-Fe3+ ) complexes respectively. The receptor L, as well as the probes (C1 , C2 ), were characterized thoroughly using mass spectroscopy, FTIR, NMR, and EA. C1 and C2 were further utilized as recyclable probes for the detection of aqueous fluoride (21 ppb) and arsenate (1.92 ppb) respectively. The computational calculation indicates that upon complexation, the spirolactam ring opening at the rhodamine B site leads to optoelectronic changes. The consistency of LFA-based portable sensing device has been tested with water samples, synthetic fluoride standards and dental care products like toothpaste and mouthwash with concentrations ≥ 3 ppm. Moreover, fixed cell imaging experiments were performed to ascertain the in-vitro sensing phenomena., (© 2022. The Author(s).)- Published
- 2022
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31. Blue energy generation by the temperature-dependent properties in funnel-shaped soft nanochannels.
- Author
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Karimzadeh M, Khatibi M, Ashrafizadeh SN, and Mondal PK
- Abstract
Salinity energy generation (SEG) studies have only been done under isothermal conditions at ambient temperature. The production of salinity energy can be improved under non-isothermal conditions, albeit preserving the energy efficiency. In the current study, the effects of gradients of temperature and concentration on the salinity energy generation process were examined simultaneously. Based on the temperature-dependent properties resulting from both temperature and concentration gradients, a numerical study was carried out to determine the maximum efficiency of salinity energy generation in funnel-shaped soft nanochannels. It was presumed that a dense layer of negative charge, called a polyelectrolyte layer (PEL), is coated on the walls of the nanochannels. Co-current and counter-current modes were used to obtain temperature and concentration gradients. Under steady-state conditions, the Poisson-Nernst-Planck, Stokes-Brinkman, and energy equations were numerically solved using equivalent approaches. The results revealed that by increasing the temperature and concentration ratios in both co-current and counter-current modes of operation, the salinity energy generation increased appreciably. The salinity energy generation increased from 30 to 80 pW upon increasing the temperature ratio from 1 to 8 at a constant concentration ratio of 1000 in counter-current mode. As verified from this analysis, low-grade heat sources (<100 °C) provide considerable energy conversion in PEL grafted nanofluidic confinement when placed between electrolyte solutions of different temperatures.
- Published
- 2022
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32. Skeletal Features of Osteogenesis Imperfecta.
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Paul R, Mondal PK, Gayen BK, Seth BC, and Sarkar R
- Subjects
- Humans, Osteogenesis Imperfecta complications, Osteogenesis Imperfecta diagnostic imaging
- Published
- 2022
33. Lattice dynamics of Ge 1 -x Sn x alloy nanowires.
- Author
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Raha S, Biswas S, Doherty J, Mondal PK, Holmes JD, and Singha A
- Abstract
Alloying group IV semiconductors offers an effective way to engineer their electronic properties and lattice dynamics. The incorporation of Sn in Ge permits a transition from an indirect to a direct bandgap semiconductor. Here, by combining polarization, laser power-dependent and temperature-dependent micro-Raman spectroscopy we explore the full lattice dynamics of Ge
1- x Snx ( x = 0.01, 0.06 and 0.08) alloy nanowires. In the high Sn content samples ( x ≥ 0.06), a low-frequency tail and a high-frequency shoulder are observed which are associated with the F2g optical phonon mode of Ge (Ge-Ge mode). The new modes are assigned to the stretching of Ge-Ge bonds due to Sn-induced lattice relaxation and compression, respectively. The symmetry of the observed Raman modes has been studied by polarization-dependent Raman scattering. Nonlinear fitting of the laser power-dependent intensity of the high-frequency Ge-Ge mode in the Ge1- x Snx alloy nanowires with x = 0.06 and 0.08 suggests the activation of a third-order stimulated Raman scattering process, due to the high intensity localized electric field surrounding the Sn clusters. Finally, from the temperature-dependent Raman study, we have estimated the isobaric Grüneisen parameters for all the observed modes.- Published
- 2022
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34. Interest In and Uptake of HIV Pre-Exposure Prophylaxis (PrEP): A Cross-Sectional Study of High-Risk Patients in Western Canada.
- Author
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Enebeli S, Okpalauwaekwe U, Mondal PK, Opondo J, and Leis A
- Abstract
Rationale Pre-exposure prophylaxis (PrEP) is a highly effective, evidence-based HIV prevention strategy. However, its use in the city of Saskatoon, Saskatchewan province of western Canada, is relatively new. Therefore, this study aimed to examine the interest and uptake of PrEP and investigate factors associated with HIV PrEP by high-risk patients. Methods A cross-sectional, self-administered survey of patients attending Saskatoon's Public Health Services Sexual Health Clinic was conducted from October until December 2018. The primary outcome was the interest in taking PrEP to reduce the risk of HIV infection. This outcome was evaluated for its association with potential correlates, which included: sociodemographic characteristics, HIV risk perception, prior PrEP awareness, and sexual behaviors/lifestyles. Descriptive, univariate, and multivariate analyses were used to pursue our research objectives. Results One hundred forty-one participants were recruited from a sexual health clinic in Saskatoon. The median age (interquartile range) was 26 (22-31) years. The median number of partners (interquartile range) was 3 (2-4) partners. A total of 66.0% of participants were unaware of PrEP, and almost half ( 49.6%) indicated an interest in taking PrEP. Among those disinterested in PrEP, 49.3% perceived minimal HIV risk, 35.2% expressed concern regarding side effects, 28.1% cited the added need for condom use, 23.9% indicated incomplete effectiveness, and 22.5% did not wish to undergo regular bloodwork. Multivariate analysis showed that interested patients were more likely to have been previously aware of PrEP (OR: 2.6, p-value = 0.03), perceived themselves to be vulnerable to HIV (OR: 15.7, p = <0.0001), or were unsure about their risk (OR: 3.9, p = 0.001). Conclusion This study suggests that a lack of knowledge regarding personal HIV risk and PrEP as a preventive option may influence PrEP interest. There lies a need for more health promotion campaigns around the health benefits of PrEP, including literacy efforts on HIV risk, concerns around side effects, and associated blood work with PrEP use., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Enebeli et al.)
- Published
- 2022
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35. Characterization of condensation on nanostructured surfaces and associated thermal hydraulics using a thermal lattice Boltzmann method.
- Author
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Mukherjee A, Basu DN, Mondal PK, and Chen L
- Abstract
The dynamics of the condensation process on nanostructured surfaces can be modulated substantially by tuning the surface architecture. Present study uses the mesoscopic framework of lattice Boltzmann method (LBM) to explore the role of surface morphology and cold spot temperature in determining the visual state of the condensate droplet, mode of nucleation, and associated rates of energy and mass interactions. A multiple relaxation time-(MRT)-based LBM solver, coupled with pseudopotential model, has been developed to simulate a rectangular domain of saturated vapor, housing a cold spot on the bottom rough surface. Superhydrophobicity has been achieved for certain combinations of surface parameters, with the intercolumn spacing being the most influential one. Gradual increase in the spacing modifies the nucleation mode from top through side to bottom, while the droplet changes from Cassie to Wenzel state. The Cassie drop in top nucleation mode exhibits the largest contact angle and least rate of surface heat transfer. Both types of Wenzel drops display large rate of condensation and two peaks in heat transfer, along with very short nucleation time in comparison with Cassie drops. Couple of phase diagrams have been developed combining all four scenarios of condensation predicted by the present model. One important novelty of the present study is the consideration of nonisothermal condition within LB structure. Enhancement in the degree of subcooling at the cold spot encourages greater condensation and Cassie-to-Wenzel transition.
- Published
- 2022
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36. Implications of updated protocol for classification of childhood malnutrition and service delivery in world's largest refugee camp amid this COVID-19 pandemic.
- Author
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Anwar A, Mondal PK, Yadav UN, Shamim AA, Rizwan AAM, and Mistry SK
- Subjects
- Body Weight, Child, Child, Preschool, Humans, Pandemics, Refugee Camps, COVID-19 epidemiology, Malnutrition diagnosis, Malnutrition epidemiology
- Abstract
Objectives: During the COVID-19 pandemic, the authorities made a change in the classification of malnutrition and concomitant service delivery protocol among the Rohingya children, residing in world's largest refugee camp, located in Cox's Bazar, Bangladesh. In this paper, we discussed the potential implications of this updated protocol on the malnutrition status among children residing in the Rohingya camps., Design: This paper reviewed relevant literature and authors' own experience to provide a perspective of the updated protocol for the classification of malnutrition among the children in the Rohingya camps and its implication from a broader perspective., Setting: Rohingya refugee camps, Bangladesh., Participants: Children aged less than five years residing in the Rohingya camps., Results: Major adaptation during this COVID-19 was the discontinuation of using weight-for-height z-score (WHZ) and the use of only mid upper arm circumference (MUAC) and presence of oedema for admission, follow-up and discharge of malnourished children in the camps. However, evidence suggests that use of MUAC only can underestimate the prevalence of malnutrition among the children in Rohingya camps. These apparently non-malnourished children are devoid of the rations that they would otherwise receive if classified as malnourished, making them susceptible to more severe malnutrition., Conclusions: Our analysis suggests that policymakers should consider using the original protocol of using both MUAC and WHZ to classify malnutrition and retain the guided ration size. We also believe that it would not take an extra effort to adopt the original guideline as even with MUAC only guideline, certain health measures needed to adopt during this pandemic.
- Published
- 2022
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37. Efficacy of adjuvant trastuzumab in women with HER2-positive T1a or bN0M0 breast cancer: a population-based cohort study.
- Author
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Ali S, Hendry J, Le D, Mondal PK, Sami A, Chalchal H, Haider K, Ahmed O, El-Gayed A, Wright P, Pauls M, Johnson K, and Ahmed S
- Subjects
- Adult, Aged, Aged, 80 and over, Antibodies, Monoclonal, Humanized therapeutic use, Breast Neoplasms pathology, Canada epidemiology, Chemotherapy, Adjuvant methods, Cohort Studies, Disease-Free Survival, Female, Humans, Middle Aged, Neoplasm Recurrence, Local drug therapy, Proportional Hazards Models, Receptor, ErbB-2 genetics, Receptor, ErbB-2 metabolism, Breast Neoplasms drug therapy, Trastuzumab therapeutic use
- Abstract
Adjuvant trastuzumab has been associated with superior survival in women with ≥ T1c or node-positive HER2-positive early-stage breast cancer; however, there is a lack of phase III trials in women with T1a/bN0 disease. Our study aimed to assess the outcomes of women with HER2-positive T1a/bN0 breast cancer who received adjuvant trastuzumab in Saskatchewan, Canada. We evaluated all women diagnosed with HER2-positive T1a/bN0 breast cancer in Saskatchewan between 2008 and 2017. We performed Cox proportional multivariable analysis to determine factors correlated with survival. In addition, inverse probability treatment weighting (IPTW) using propensity score was performed to assess benefit of adjuvant trastuzumab. Ninety-one eligible women with a median age of 61 years (range 30-89) were identified. Thirty-nine (43%) women received adjuvant trastuzumab. Women who received trastuzumab were younger and had a higher rate of T1b disease. Overall, 3% of women who received trastuzumab compared to 12% of women who did not receive trastuzumab developed breast cancer recurrence (p = 0.23). Five-year disease-free survival (DFS) of women who received adjuvant trastuzumab was 94.8% compared to 82.7% of women who did not receive trastuzumab (p = 0.22). Five-year overall survival was 100% of women who received trastuzumab compared to 90.4% of women who did not receive adjuvant trastuzumab (p = 0.038). In the multivariable analysis, grade III tumors were correlated with inferior DFS (hazard ratio [HR] 5.5, 95% CI [1.7-17.7]). The propensity score using the inverse probability of treatment weighting showed that lack of adjuvant trastuzumab was correlated inferior DFS, with an HR of 4 (95% CI 1.05-15.5). Women with HER2-positive T1a/bN0 breast cancer had overall low recurrence of breast cancer. However, the results of this exploratory analysis indicate that women who received adjuvant trastuzumab had better survival., (© 2022. The Author(s).)
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- 2022
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38. Direct Arylation of Distal and Proximal C(sp 3 )-H Bonds of t -Amines with Aryl Diazonium Tetrafluoroborates via Photoredox Catalysis.
- Author
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Mondal PK, Tiwari SK, Singh P, and Pandey G
- Subjects
- Catalysis, Oxidation-Reduction, Amines, Light
- Abstract
A visible light-mediated arylation protocol for t- amines has been reported through the coupling of γ - and α -amino alkyl radicals with different aryl diazonium salts using Ru(bpy)
3 Cl2 ·6H2 O as a photocatalyst. Structurally different 9-aryl-9,10-dihydroacridine, 1-aryl tetrahydroisoquinoline, hexahydropyrrolo[2,1- a ]isoquinoline, and hexahydro-2 H -pyrido[2,1- a ]isoquinoline frameworks with different substitution patterns have been synthesized in good yield using this methodology.- Published
- 2021
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39. Numerical study of the vortex-induced electroosmotic mixing of non-Newtonian biofluids in a nonuniformly charged wavy microchannel: Effect of finite ion size.
- Author
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Mehta SK, Pati S, and Mondal PK
- Subjects
- Rheology, Electroosmosis, Models, Chemical
- Abstract
We propose a micromixer for obtaining better efficiency of vortex induced electroosmotic mixing of non-Newtonian bio-fluids at a relatively higher flow rate, which finds relevance in many biomedical and biological applications. To represent the rheology of non-Newtonian fluid, we consider the Carreau model in this study, while the applied electric field drives the constituent components in the micromixer. We show that the spatial variation of the applied field, triggered by the topological change of the bounding surfaces, upon interacting with the non-uniform surface potential gives rise to efficient mixing as realized by the formation of vortices in the proposed micromixer. Also, we show that the phase-lag between surface potential leads to the formation of asymmetric vortices. This behavior offers better mixing performance following the appearance of undulation on the flow pattern. Finally, we establish that the assumption of a point charge in the paradigm of electroosmotic mixing, which is not realistic as well, under-predicts the mixing efficiency at higher amplitude of the non-uniform zeta potential. The inferences of the present analysis may guide as a design tool for micromixer where rheological properties of the fluid and flow actuation parameters can be simultaneously tuned to obtain phenomenal enhancement in mixing efficiency., (© 2021 Wiley-VCH GmbH.)
- Published
- 2021
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40. Favorable and unfavorable attachment of colloids in a discrete sandstone fracture.
- Author
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Spanik S, Rrokaj E, Mondal PK, and Sleep BE
- Subjects
- Microspheres, Osmolar Concentration, Porosity, Colloids
- Abstract
The transport of cationic amine-modified latex (AML) and anionic carboxylate-modified latex (CML) microspheres through a discrete sandstone fracture with mineralogical heterogeneity and roughness was studied. Two microsphere sizes (200 nm and 1000 nm), two ionic strengths (5 mM and 10 mM), and two specific discharges (0.35 mm.s-1 and 0.70 mm.s-1) were tested to observe the impact on transport under favorable and unfavorable conditions. The difference in retention between AML (net favorable) and CML (net unfavorable) microsphere attachment was 25% for the 200 nm microspheres and 13% for the 1000 nm microspheres. Less than 50% of the AML microspheres were retained in the fracture, postulated to be due to the effects of mineralogical heterogeneity and fracture surface roughness. The effect of an increase in ionic strength in increasing retention was significant for unfavorable attachment, but was not significant for favorable attachment conditions. The effect of specific discharge was minor for all but the 200 nm CML microspheres at 10 mM ionic strength. When flushing the fracture first with cationic microspheres, then with anionic microspheres, the recovery of anionic microspheres resembled favorable attachment presumably due to interaction with cationic microspheres that remained attached to the sandstone surface. Colloid breakthrough curves could be fit well with a two site attachment model, with reversible and irreversible sites., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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41. Spreadsheet analysis of the field-driven start-up flow in a microfluidic channel.
- Author
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Mondal PK and Roy M
- Subjects
- Electroosmosis, Microfluidics, Models, Theoretical
- Abstract
We discuss, in this article, the solution method of the unsteady electroosmotic flow of Newtonian fluid in a square microfluidic channel cross-section in the framework of spreadsheet analysis. We demonstrate the implementation of the finite difference scheme, which is used for the discretization of the transport equations governing the flow dynamics of the present problem, in the spreadsheet tool. Also, we have shown the implementation details of different boundary conditions, which are typically used for the underlying electrohydrodynamics in a microfluidic channel, in the spreadsheet analysis tool. We show that the results obtained from the spreadsheet analysis match accurately with the numerical solutions for both the electrostatic potential distribution and the flow velocity. Our results of this analysis justify the credibility of the spreadsheet tool for capturing the intricate details of the electrically actuated microflows during the initial transiences, that is, for the start-up flows and the phenomenon due to the electrical double layer effect, quite effectively. The inferences of this analysis will open up a new research paradigm of microfluidics and microscale transport processes by providing the potential applicability of the spreadsheet tools to obtain the flow physics of our interest in a very intuitive and less expensive manner., (© 2021 Wiley-VCH GmbH.)
- Published
- 2021
- Full Text
- View/download PDF
42. Acute Kidney Injury in Hornet Sting: Two Cases from East India.
- Author
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Paul R, Mondal PK, Gayen BK, and Seth BC
- Subjects
- Animals, India, Acute Kidney Injury etiology, Insect Bites and Stings, Wasps
- Published
- 2021
43. Quantitative model for predicting the imbibition dynamics of viscoelastic fluids in nonuniform microfluidic assays.
- Author
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Rawat Y, Kalia S, and Mondal PK
- Abstract
We develop a mathematical model to quantitatively describe the imbibition dynamics of an elastic non-Newtonian fluid in a conical (nonuniform cross section) microfluidic assay. We consider the simplified Phan-Thien-Tanner viscoelastic model to represent the rheology of the elastic non-Newtonian fluid. Our model accounts for the geometrical features of the fluidic assay, the key parameters affecting the rheological behavior of the fluid, and predicts the imbibition dynamics effectively. By demonstrating the temporal advancement of the filling length in the conical capillary graphically, obtained for pertinent parametric values belonging to their physically permissible range, we report an underlying balance between capillary and viscous forces during imbibition resulting in three distinct regimes of filling. Nonuniformity in the capillary cross section gives rise to an alteration in the viscous force being applied at the contact line (manifested through the alteration in shear rate) during the imbibition process, which upon maintaining a balance with the dominant capillary force results in three different regimes of filling. We believe that the present analysis has a twofold significance. First, this work will enhance the understanding of underlying imbibition dynamics of viscoelastic fluids (most of the biofluids exhibit viscoelastic rheology) in nonuniform fluidic pathways. Second, the developed model is of significant practical relevance for the optimum design of microfluidic assays, primarily used for sample diagnostics in biochemical and biomedical applications.
- Published
- 2021
- Full Text
- View/download PDF
44. Cocrystals, Salts, and Salt-Solvates of olanzapine; selection of coformers and improved solubility.
- Author
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Gong W, Mondal PK, Ahmadi S, Wu Y, and Rohani S
- Subjects
- Crystallization, Hydrogen Bonding, Olanzapine, Solubility, Salts
- Abstract
Pharmaceutical cocrystals and salts are extensively researched in recent years due to their ability to tune the physicochemical properties of active pharmaceutical ingredients (APIs). A model API, olanzapine, an atypical antipsychotic drug classified as Biopharmaceutical Classification System class II, is used in this study. Cocrystals and salts of olanzapine are discovered using solvent drop grinding and ball milling. Appropriate coformers were selected based on a combination of hydrogen-bond propensity (HBP) and hydrogen-bond coordination (HBC) calculations. Eight new multicomponent phases of olanzapine, including one cocrystal hydrate with phenol; four anhydrous salts with salicylic acid, terephthalic acid, anthranilic acid, 3-hydroxybenzoic acid, and 2-aminoterephthalic acid; one salt dihydrate with terephthalic acid; and one salt solvate with 3-hydroxybenzoic acid and acetonitrile, have been discovered and characterized by PXRD and DSC. One reported cocrystal (olanzapine-resorcinol) has also been considered for the dissolution test. All these newly formed solid phases followed the "ΔpK
a rule of 3". The crystal structures of cocrystal/salts were determined by single-crystal X-ray (sc-XRD) diffraction. With the collected single-crystal data, the crystal packings were found to be primarily stabilized via strong hydrogen bonds between carboxyl, phenolic hydroxyl of co-formers/salt-formers with the piperazine and diazepine nitrogen of olanzapine, which confirmed the predicted result from the HBP and HBC calculations. HPLC coupled with UV-vis detector was used in the solubility and dissolution test instead of UV-vis spectroscopy, to avoid the peak overlap between olanzapine and co-formers/salt-formers. A threefold increase in the solubility was observed in olanzapinium 3-hydroxybenzoate and olanzapinium anthranilate, and an almost fivefold increase in solubility of olanzapinium 2-aminoterephthalate., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
- Full Text
- View/download PDF
45. p -Silylation of Arenes via Organic Photoredox Catalysis: Use of p -Silylated Arenes for Exclusive o -Silylation, o -Acylation, and o -Alkylation Reactions.
- Author
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Pandey G, Tiwari SK, Singh P, and Mondal PK
- Abstract
Photocatalytic regiospecific p -silylation of arenes has been achieved by the coupling of in situ generated silyl radical with arene radical cation. The strategy involves reductive activation of PhSe-SiR
3 and single electron transfer from the electron rich arene to 9,10-dimethoxyanthracene radical cation (DMA•+ ). p -Silyl arenes, thus formed, are further utilized for exclusive o -silylation reaction and for regiospecific o -acylation as well as o- alkylation reaction.- Published
- 2021
- Full Text
- View/download PDF
46. Demographics, Pattern of Care, and Outcome Analysis of Malignant Melanomas - Experience From a Tertiary Cancer Centre in India.
- Author
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Bajpai J, Abraham G, Saklani AP, Agarwal A, Das S, Chatterjee A, Kapoor A, Eaga P, Mondal PK, Chandrasekharan A, Bhargava PG, Srinivas S, Turkar S, Rekhi B, Khanna N, Janu AK, Bal M, Ostwal VS, Ramaswamy A, Rohila J, Desouza AL, Guha A, Kumar R, Menon NS, Rath S, Patil VM, Noronha VM, Joshi AP, Laskar S, Rangarajan V, Prabhash K, Gupta S, and Banavali S
- Abstract
Background: Treatment of malignant melanoma has undergone a paradigm shift with the advent of immune checkpoint inhibitors (ICI) and targeted therapies. However, access to ICI is limited in low-middle income countries (LMICs)., Patients and Methods: Histologically confirmed malignant melanoma cases registered from 2013 to 2019 were analysed for pattern of care, safety, and efficacy of systemic therapies (ST)., Results: There were 659 patients with a median age of 53 (range 44-63) years; 58.9% were males; 55.2% were mucosal melanomas. Most common primary sites were extremities (36.6%) and anorectum (31.4%). Nearly 10.8% of the metastatic cohort were BRAF mutated. Among 368 non-metastatic patients (172 prior treated, 185 de novo, and 11 unresectable), with a median follow-up of 26 months (0-83 months), median EFS and OS were 29.5 (95% CI: 22-40) and 33.3 (95% CI: 29.5-41.2) months, respectively. In the metastatic cohort, with a median follow up of 24 (0-85) months, the median EFS for BSC was 3.1 (95% CI 1.9-4.8) months versus 3.98 (95% CI 3.2-4.7) months with any ST (HR: 0.69, 95% CI: 0.52-0.92; P = 0.011). The median OS was 3.9 (95% CI 3.3-6.4) months for BSC alone versus 12.0 (95% CI 10.5-15.1) months in any ST (HR: 0.38, 95% CI: 0.28-0.50; P < 0.001). The disease control rate was 51.55%. Commonest grade 3-4 toxicity was anemia with chemotherapy (9.5%) and ICI (8.8%). In multivariate analysis, any ST received had a better prognostic impact in the metastatic cohort., Conclusions: Large real-world data reflects the treatment patterns adopted in LMIC for melanomas and poor access to expensive, standard of care therapies. Other systemic therapies provide meaningful clinical benefit and are worth exploring especially when the standard therapies are challenging to administer., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Bajpai, Abraham, Saklani, Agarwal, Das, Chatterjee, Kapoor, Eaga, Mondal, Chandrasekharan, Bhargava, Srinivas, Turkar, Rekhi, Khanna, Janu, Bal, Ostwal, Ramaswamy, Rohila, Desouza, Guha, Kumar, Menon, Rath, Patil, Noronha, Joshi, Laskar, Rangarajan, Prabhash, Gupta and Banavali.)
- Published
- 2021
- Full Text
- View/download PDF
47. PseudoGA: cell pseudotime reconstruction based on genetic algorithm.
- Author
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Mondal PK, Saha US, and Mukhopadhyay I
- Subjects
- Cell Cycle genetics, Cells, Cultured, Cluster Analysis, Humans, Muscle, Skeletal cytology, Myoblasts cytology, RNA-Seq methods, Algorithms, Computational Biology methods, Gene Expression Profiling methods, Muscle, Skeletal metabolism, Myoblasts metabolism, Single-Cell Analysis methods, Transcriptome genetics
- Abstract
Dynamic regulation of gene expression is often governed by progression through transient cell states. Bulk RNA-seq analysis can only detect average change in expression levels and is unable to identify this dynamics. Single cell RNA-seq presents an unprecedented opportunity that helps in placing the cells on a hypothetical time trajectory that reflects gradual transition of their transcriptomes. This continuum trajectory or 'pseudotime', may reveal the developmental pathway and provide us with information on dynamic transcriptomic changes and other biological processes. Existing approaches to build pseudotime heavily depend on reducing huge dimension to extremely low dimensional subspaces and may lead to loss of information. We propose PseudoGA, a genetic algorithm based approach to order cells assuming that gene expressions vary according to a smooth curve along the pseudotime trajectory. We observe superior accuracy of our method in simulated as well as benchmarking real datasets. Generality of the assumption behind PseudoGA and no dependence on dimensionality reduction technique make it a robust choice for pseudotime estimation from single cell transcriptome data. PseudoGA is also time efficient when applied to a large single cell RNA-seq data and adaptable to parallel computing. R code for PseudoGA is freely available at https://github.com/indranillab/pseudoga., (© The Author(s) 2021. Published by Oxford University Press on behalf of Nucleic Acids Research.)
- Published
- 2021
- Full Text
- View/download PDF
48. Reciprocal interplay between asporin and decorin: Implications in gastric cancer prognosis.
- Author
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Basak D, Jamal Z, Ghosh A, Mondal PK, Dey Talukdar P, Ghosh S, Ghosh Roy B, Ghosh R, Halder A, Chowdhury A, Dhali GK, Chattopadhyay BK, Saha ML, Basu A, Roy S, Mukherjee C, Biswas NK, Chatterji U, and Datta S
- Subjects
- Decorin genetics, Extracellular Matrix Proteins genetics, Female, Humans, Kaplan-Meier Estimate, Male, Middle Aged, Neoplasm Staging, Phosphorylation, Prognosis, Protein Binding, RNA, Messenger metabolism, Smad2 Protein metabolism, Stomach Neoplasms mortality, Transforming Growth Factor beta metabolism, Vascular Endothelial Growth Factor A metabolism, Decorin metabolism, Extracellular Matrix Proteins metabolism, Stomach Neoplasms pathology
- Abstract
Effective patient prognosis necessitates identification of novel tumor promoting drivers of gastric cancer (GC) which contribute to worsened conditions by analysing TCGA-gastric adenocarcinoma dataset. Small leucine-rich proteoglycans, asporin (ASPN) and decorin (DCN), play overlapping roles in development and diseases; however, the mechanisms underlying their interplay remain elusive. Here, we investigated the complex interplay of asporin, decorin and their interaction with TGFβ in GC tumor and corresponding normal tissues. The mRNA levels, protein expressions and cellular localizations of ASPN and DCN were analyzed using real-time PCR, western blot and immunohistochemistry, respectively. The protein-protein interaction was predicted by in-silico interaction analysis and validated by co-immunoprecipitation assay. The correlations between ASPN and EMT proteins, VEGF and collagen were achieved using western blot analysis. A significant increase in expression of ASPN in tumor tissue vs. normal tissue was observed in both TCGA and our patient cohort. DCN, an effective inhibitor of the TGFβ pathway, was negatively correlated with stages of GC. Co-immunoprecipitation demonstrated that DCN binds with TGFβ, in normal gastric epithelium, whereas in GC, ASPN preferentially binds TGFβ. Possible activation of the canonical TGFβ pathway by phosphorylation of SMAD2 in tumor tissues suggests its role as an intracellular tumor promoter. Furthermore, tissues expressing ASPN showed unregulated EMT signalling. Our study uncovers ASPN as a GC-promoting gene and DCN as tumor suppressor, suggesting that ASPN can act as a prognostic marker in GC. For the first time, we describe the physical interaction of TGFβ with ASPN in GC and DCN with TGFβ in GC and normal gastric epithelium respectively. This study suggests that prevention of ASPN-TGFβ interaction or overexpression of DCN could serve as promising therapeutic strategies for GC patients., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2021
- Full Text
- View/download PDF
49. Multifunctional liquid marbles to stabilize and transport reactive fluids.
- Author
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Harsha L, Bhuyan T, Maity S, Mondal PK, Ghosh SS, and Bandyopadhyay D
- Abstract
The self-organized transport and delivery of reactive liquids without spillage or loss of activity have been among the most daunting challenges for a long time. In this direction, we employ the concept of forming "liquid marbles" (LMs) to encapsulate and transport reactive hydrogen peroxide (H2O2) coated with functional microparticles. For example, peroxide marbles coated with a toner ink display remote-controlled magnetotactic movement inside a fluidic medium, thus overcoming the weaknesses associated with use of the bare droplets. Interestingly, in such a scenario, the coating of the marbles could also be removed or reformed by bringing the magnet towards or away from the marble. In this way, this process could ensure an on-demand remotely guided coating on the peroxide droplet or its removal. The liquid marbles carrying peroxide solutions are found to preserve the activity of the peroxide and exhibit a low evaporation rate compared with the uncoated peroxide fuel. Interestingly, oil droplets floating on the water could be recovered by introducing the armoured LMs into water under magnetic guidance. Further, the functionalized marbles could be employed as suicide bags for the on-demand delivery of reactive materials in targeted locations. Preliminary research on the antibacterial activity of such liquid marbles has proven to be effective in bacterial killing, which may create new avenues for emerging antibacterial and antibiofilm applications. Finally, such functionalized LMs have been employed to investigate the effects of surface charge on attachment of recombinant Escherichia coli bacteria expressing green fluorescent protein and monitoring the real-time imaging of bacterial death attached to the marble surface.
- Published
- 2021
- Full Text
- View/download PDF
50. Algorithmic augmentation in the pseudopotential-based lattice Boltzmann method for simulating the pool boiling phenomenon with high-density ratio.
- Author
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Mukherjee A, Basu DN, and Mondal PK
- Abstract
The pseudopotential-based lattice Boltzmann method (LBM), despite enormous potential in facilitating natural development and migration of interfaces during multiphase simulation, remains restricted to low-density ratios, owing to inherent thermodynamic inconsistency. The present paper focuses on augmenting the basic algorithm by enhancing the isotropy of the discrete equation and thermodynamic consistency of the overall formulation, to expedite simulation of pool boiling at higher-density ratios. Accordingly, modification is suggested in the discrete form of the updated interparticle interaction term, by expanding the discretization to the eighth order. The proposed amendment is successful in substantially reducing the spurious velocity in the vicinity of a static droplet, while allowing stable simulation at a much higher-density ratio under identical conditions, which is a noteworthy improvement over existing Single Relaxation Time (SRT)-LBM algorithms. Various pool boiling scenarios have been explored for a reduced temperature of 0.75, which itself is significantly lower than reported in comparable literature, in both rectangular and cylindrical domains, and also with micro- and distributed heaters. All three regimes of pool boiling have aptly been captured with both plain and structured heaters, allowing the development of the boiling curve. The predicted value of critical heat flux for the plain heater agrees with Zuber correlation within 10%, illustrating both quantitative and qualitative capability of the proposed algorithm.
- Published
- 2021
- Full Text
- View/download PDF
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