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Sehrin F, Jin L, Naher K, Das NC, Chan VF, Li DF, Bergson S, Gudwin E, Clarke M, Stephan T, Congdon N. The effect on income of providing near vision correction to workers in Bangladesh: The THRIVE (Tradespeople and Hand-workers Rural Initiative for a Vision-enhanced Economy) randomized controlled trial. PLoS One 2024; 19:e0296115. [PMID: 38568883 PMCID: PMC10990163 DOI: 10.1371/journal.pone.0296115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 11/29/2023] [Indexed: 04/05/2024] Open
Abstract
INTRODUCTION Presbyopia, the leading cause of vision impairment globally, is common during working years. However, no trials have assessed presbyopia's impact on income. METHODS In April 2017, we conducted a census among 59 Bangladesh villages to identify persons aged 35 to 65 years with presbyopia (presenting distance vision > = 6/12 bilaterally and correctable inability to see 6/13 at 40 cm with both eyes), who never had owned glasses. Participants were randomized (1:1) to receive immediate free reading glasses (intervention) or glasses delivered 8 months later (control). Visual demand of different jobs was stratified into three levels. Outcomes were between-group differences in the 8 month change in: self-reported monthly income (primary) and Near Vision Related Quality of Life (NVRQOL, secondary). RESULTS Among 10,884 census participants, 3,655 (33.6%) met vision criteria and 863 (23.6%) comprised a sample enriched for near vision-intensive jobs, but 39 (4.52%) could not be reached. All participants allocated to intervention (n = 423, 51.3%) and control (n = 401, 48.7%) received the appropriate intervention, and follow-up was available for 93.4% and 96.8% respectively. Groups were similar at baseline in all characteristics: mean age was 47 years, 50% were male, 35% literate, and about half engaged in "most near vision-intensive" occupations. Glasses wear at 8-month follow-up was 88.3% and 7.81% in intervention and control respectively. At baseline, both the intervention and control groups had a self-reported median monthly income of US$35.3. At endline, the median income for the intervention group was US$47.1 compared with US$35.3 for control, a difference of 33.4%. Predictors of greater income increase in multivariate models included intervention group allocation (OR 1.45, 95% CI 1.12, 1.88, P = 0.005), male sex (OR 2.41, 95% CI 1.84, 3.16, P <0.001), and not engaging in income-producing work at baseline (OR 2.35, 95% CI 1.69, 3.26, P<0.001). CONCLUSION Provision of reading glasses increases income in near vision-intensive occupations, and may facilitate return to work for those currently unemployed.
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Affiliation(s)
- Farzana Sehrin
- BRAC (Formerly: Bangladesh Rural Advancement Committee), Dhaka, Bangladesh
| | - Ling Jin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Kamrun Naher
- BRAC (Formerly: Bangladesh Rural Advancement Committee), Dhaka, Bangladesh
| | | | - Ving Fan Chan
- University of KwaZulu Natal, Durban, South Africa
- Centre for Public Health, Queen’s University Belfast, Belfast, Northern Ireland, United Kingdom
| | - Dong Feng Li
- Centre for Public Health, Queen’s University Belfast, Belfast, Northern Ireland, United Kingdom
| | - Susan Bergson
- VisionSpring, New York, New York, United States of America
| | - Ella Gudwin
- VisionSpring, New York, New York, United States of America
| | - Mike Clarke
- Centre for Public Health, Queen’s University Belfast, Belfast, Northern Ireland, United Kingdom
| | - Tai Stephan
- Orbis International, New York, New York, United States of America
| | - Nathan Congdon
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- Centre for Public Health, Queen’s University Belfast, Belfast, Northern Ireland, United Kingdom
- Orbis International, New York, New York, United States of America
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Ghosh T, Nandi S, Girigoswami A, Bhattacharyya SK, Ghosh SK, Mandal M, Ghorai UK, Banerji P, Das NC. Carbon Dots for Multiuse Platform: Intracellular pH Sensing and Complementary Intensified T1-T2 Dual Imaging Contrast Nanoprobes. ACS Biomater Sci Eng 2024; 10:1112-1127. [PMID: 38163852 DOI: 10.1021/acsbiomaterials.3c01389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
Measurement of pH in living cells is a great and decisive factor for providing an early and accurate diagnosis factor. Along with this, the multimodal transverse and longitudinal relaxivity enhancement potentiality over single modality within a single platform in the magnetic resonance imaging (MRI) field is a very challenging issue for diagnostic purposes in the biomedical field of application. Therefore, this work aims to design a versatile platform by fabricating a novel nanoprobe through holmium- and manganese-ion doping in carbon quantum dots (Ho-Mn-CQDs), which can show nearly neutral intracellular pH sensing and MRI imaging at the same time. These manufactured Ho-Mn-CQDs acted as excellent pH sensors in the near-neutral range (4.01-8.01) with the linearity between 6.01 and 8.01, which could be useful for the intracellular pH-sensing capability. An innumerable number of carboxyl and amino groups are present on the surface of the prepared nanoprobe, making it an excellent candidate for pH sensing through fluorescence intensity quenching phenomena. Cellular uptake and cell viability experiments were also executed to affirm the intracellular accepting ability of Ho-Mn-CQDs. Furthermore, with this pH-sensing quality, these Ho-Mn-CQDs are also capable of acting as T1-T2 dual modal imaging contrast agents in comparison with pristine Ho-doped and Mn-doped CQDs. The Ho-Mn-CQDs showed an increment of r1 and r2 relaxivity values simultaneously compared with only the negative contrast agent, holmium in holmium-doped CQDs, and the positive contrast agent, manganese in manganese-doped CQDs. The above-mentioned observations elucidate that its tiny size, excitation dependence of fluorescence behavior, low cytotoxicity, and dual modal contrast imaging capability make it an ideal candidate for pH monitoring in the near-neutral range and also as a dual modal MRI imaging contrast enhancement nanoprobe at the same time.
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Affiliation(s)
- Trisita Ghosh
- Rubber Technology Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Suvendu Nandi
- School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Agnishwar Girigoswami
- Medical Bionanotechnology, Faculty of Allied Health Sciences, Chettinad Hospital and Research Institute (CHRI), Chettinad Academy of Research and Education (CARE), Kelambakkam, Chennai 603 103, India
| | | | - Suman Kumar Ghosh
- Rubber Technology Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Mahitosh Mandal
- School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Uttam Kumar Ghorai
- Department of Industrial Chemistry and Applied Chemistry, Ramakrishna Mission Vidyamandira, Howrah 711202, India
| | - Pallab Banerji
- Materials Science Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Narayan Chandra Das
- Rubber Technology Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
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Maity PP, Kapat K, Poddar P, Bora H, Das CK, Das P, Ganguly S, Das NC, Dhara D, Mandal M, Roy Chowdhury A, Mukherjee S, Dhara S. Capra cartilage-derived peptide delivery via carbon nano-dots for cartilage regeneration. Front Bioeng Biotechnol 2023; 11:1213932. [PMID: 37701494 PMCID: PMC10493328 DOI: 10.3389/fbioe.2023.1213932] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/15/2023] [Indexed: 09/14/2023] Open
Abstract
Targeted delivery of site-specific therapeutic agents is an effective strategy for osteoarthritis treatment. The lack of blood vessels in cartilage makes it difficult to deliver therapeutic agents like peptides to the defect area. Therefore, nucleus-targeting zwitterionic carbon nano-dots (CDs) have immense potential as a delivery vehicle for effective peptide delivery to the cytoplasm as well as nucleus. In the present study, nucleus-targeting zwitterionic CDs have been synthesized as delivery vehicle for peptides while also working as nano-agents towards optical monitoring of cartilage healing. The functional groups of zwitterion CDs were introduced by a single-step microwave assisted oxidation procedure followed by COL II peptide conjugation derived from Capra auricular cartilage through NHS/EDC coupling. The peptide-conjugated CDs (PCDs) allows cytoplasmic uptake within a short period of time (∼30 m) followed by translocation to nucleus after ∼24 h. Moreover, multicolor fluorescence of PCDs improves (blue, green, and read channel) its sensitivity as an optical code providing a compelling solution towards enhanced non-invasive tracking system with multifunctional properties. The PCDs-based delivery system developed in this study has exhibited superior ability to induce ex-vivo chondrogenic differentiation of ADMSCs as compared to bare CDs. For assessment of cartilage regeneration potential, pluronic F-127 based PCDs hydrogel was injected to rabbit auricular cartilage defects and potential healing was observed after 60 days. Therefore, the results confirm that PCDs could be an ideal alternate for multimodal therapeutic agents.
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Affiliation(s)
| | - Kausik Kapat
- Department of Medical Devices, NIPER Kolkata, Kolkata, India
| | - Puja Poddar
- Department of Chemistry, IIT Kharagpur, Kharagpur, India
| | - Hema Bora
- School of Medical Science and Technology, IIT Kharagpur, Kharagpur, India
| | - Chandan Kanta Das
- School of Medical Science and Technology, IIT Kharagpur, Kharagpur, India
| | - Poushali Das
- Department of Chemistry, IIT Kharagpur, Kharagpur, India
| | - Sayan Ganguly
- Department of Chemistry, IIT Kharagpur, Kharagpur, India
| | | | - Dibakar Dhara
- Department of Chemistry, IIT Kharagpur, Kharagpur, India
| | - Mahitosh Mandal
- School of Medical Science and Technology, IIT Kharagpur, Kharagpur, India
| | - Amit Roy Chowdhury
- Aerospace Engineering and Applied Mechanics, IIEST Shibpur, Howrah, West Bengal, India
| | - Sumanta Mukherjee
- Production Engineering Department, BIT Sindri, Dhanbad, Jharkhand, India
| | - Santanu Dhara
- School of Medical Science and Technology, IIT Kharagpur, Kharagpur, India
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Panda P, Dutta A, Pal S, Ganguly D, Chattopadhyay S, Das NC, Das RK. Strain sensing multi-stimuli responsive light emitting lanthanide-based tough and stretchable hydrogels with tunable luminescence and fast self-recovery using metal-ligand and hydrophobic interaction. NEW J CHEM 2023. [DOI: 10.1039/d2nj05263f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Lanthanide-based hydrogels have recently attracted massive interest due to their multipurpose applications like optical sensing, optical image probe, UV OLED, electroluminescent device and biological applications. Here we have developed dual...
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Bhattacharyya SK, Nandi S, Dey T, Ray SK, Mandal M, Das NC, Banerjee S. Fabrication of a Vitamin B12-Loaded Carbon Dot/Mixed-Ligand Metal Organic Framework Encapsulated within the Gelatin Microsphere for pH Sensing and In Vitro Wound Healing Assessment. ACS Appl Bio Mater 2022; 5:5693-5705. [PMID: 36475584 DOI: 10.1021/acsabm.2c00725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Bacterial invasion is a serious concern during the wound healing process. The colonization of bacteria is mainly responsible for the pH fluctuation at the wound site. Therefore, the fabrication of a proper wound dressing material with antibacterial activity and pH monitoring ability is necessary to acquire a fast healing process. Therefore, this work is dedicated to designing a vitamin B12-loaded gelatin microsphere (MS) decorated with a carbon dot (CD) metal-organic framework (MOF) for simultaneous pH sensing and advanced wound closure application. The resultant MS portrayed a high specific surface area and a hierarchically porous structure. Furthermore, the surface of the resultant MS contained numerous carboxyl groups and amine groups whose deprotonation and protonation with the pH alternation are accountable for the pH-sensitive properties. The vitamin B12 release study was speedy from the MOF structure in an acidic medium, which was checked by gelatin coating, and a controlled drug release behavior was observed. The system showed excellent cytocompatibility toward the L929 cell line and remarkable antibacterial performance against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Furthermore, the combined effect of Zn2+, the imidazole unit, and CDs produces an outstanding bactericidal effect on the injury sites. Finally, the in vitro wound model suggests that the presence of the vitamin B12-loaded gelatin MS accelerates the proliferation of resident fibroblast L929 cells and causes tissue regeneration in a time-dependent manner. The relative wound area, % of wound closure, and wound healing speed values are remarkable and suggest the requirement for assessing the response of the system before exploiting its prospective in vivo application.
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Affiliation(s)
| | - Suvendu Nandi
- School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur721302, India
| | - Tamal Dey
- Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur721302, India
| | - Samit Kumar Ray
- School of Nano Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur721302, India.,Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur721302, India
| | - Mahitosh Mandal
- School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur721302, India
| | - Narayan Chandra Das
- School of Nano Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur721302, India.,Rubber Technology Centre, Indian Institute of Technology Kharagpur, Kharagpur721302, India
| | - Susanta Banerjee
- School of Nano Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur721302, India.,Materials Science Centre, Indian Institute of Technology Kharagpur, Kharagpur721302, India
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Nath K, Ghosh SK, Katheria A, Das P, Das NC. Facile production of binary polymer/carbonic nanofiller‐based biodegradable electromagnetic interference shield films with low electrical percolation threshold. POLYM ENG SCI 2022. [DOI: 10.1002/pen.26151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Krishnendu Nath
- Rubber Technology Centre Indian Institute of Technology Kharagpur India
| | - Suman Kumar Ghosh
- Rubber Technology Centre Indian Institute of Technology Kharagpur India
| | - Ankur Katheria
- Rubber Technology Centre Indian Institute of Technology Kharagpur India
| | - Palash Das
- Rubber Technology Centre Indian Institute of Technology Kharagpur India
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Sit S, Chakraborty G, Das NC. Superior
EMI
shielding effectiveness with enhanced electrical conductivity at low percolation threshold of flexible novel ethylene methyl acrylate/single‐walled carbon nanotube nanocomposites. POLYM ENG SCI 2022. [DOI: 10.1002/pen.25987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Subhashis Sit
- Department of Mechanical Engineering Indian Institute of Technology Kharagpur Kharagpur India
| | - Goutam Chakraborty
- Department of Mechanical Engineering Indian Institute of Technology Kharagpur Kharagpur India
| | - Narayan Chandra Das
- Rubber Technology Centre Indian Institute of Technology Kharagpur Kharagpur India
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Remanan S, Padmavathy N, Rabiya R, Ghosh S, Das TK, Bose S, Sen R, Das NC. Converting Polymer Trash into Treasure: An Approach to Prepare MoS 2 Nanosheets Decorated PVDF Sponge for Oil/Water Separation and Antibacterial Applications. Ind Eng Chem Res 2020. [DOI: 10.1021/acs.iecr.0c03069] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Sanjay Remanan
- Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302, West Bengal, India
| | - Nagarajan Padmavathy
- Department of Materials Engineering, Indian Institute of Science, Bangalore 560012, Karnataka, India
| | - Rabiya Rabiya
- Department of Biotechnology, Indian Institute of Technology, Kharagpur 721302, West Bengal, India
| | - Sabyasachi Ghosh
- Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302, West Bengal, India
| | - Tushar Kanti Das
- Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302, West Bengal, India
| | - Suryasarathi Bose
- Department of Materials Engineering, Indian Institute of Science, Bangalore 560012, Karnataka, India
| | - Ramkrishna Sen
- Department of Biotechnology, Indian Institute of Technology, Kharagpur 721302, West Bengal, India
| | - Narayan Chandra Das
- Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302, West Bengal, India
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Bhattacharyya SK, Dule M, Paul R, Dash J, Anas M, Mandal TK, Das P, Das NC, Banerjee S. Carbon Dot Cross-Linked Gelatin Nanocomposite Hydrogel for pH-Sensing and pH-Responsive Drug Delivery. ACS Biomater Sci Eng 2020; 6:5662-5674. [PMID: 33320568 DOI: 10.1021/acsbiomaterials.0c00982] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Delivery of therapeutics to the intestinal region bypassing the harsh acidic environment of the stomach has long been a research focus. On the other hand, monitoring a system's pH during drug delivery is a crucial diagnosis factor as the activity and release rate of many therapeutics depend on it. This study answered both of these issues by fabricating a novel nanocomposite hydrogel for intestinal drug delivery and near-neutral pH sensing at the same time. Gelatin nanocomposites (GNCs) with varying concentrations of carbon dots (CDs) were fabricated through simple solvent casting methods. Here, CDs served a dual role and simultaneously acted as a cross-linker and chromophore, which reduced the usage of toxic cross-linkers. The proposed GNC hydrogel sample acted as an excellent pH sensor in the near-neutral pH range and could be useful for quantitative pH measurement. A model antibacterial drug (cefadroxil) was used for the in vitro drug release study at gastric pH (1.2) and intestinal pH (7.4) conditions. A moderate and sustained drug release profile was noticed at pH 7.4 in comparison to the acidic medium over a 24 h study. The drug release profile revealed that the pH of the release medium and the percentage of CDs cross-linking influenced the drug release rate. Release data were compared with different empirical equations for the evaluation of drug release kinetics and found good agreement with the Higuchi model. The antibacterial activity of cefadroxil was assessed by the broth microdilution method and found to be retained and not hindered by the drug entrapment procedure. The cell viability assay showed that all of the hydrogel samples, including the drug-loaded GNC hydrogel, offered acceptable cytocompatibility and nontoxicity. All of these observations illustrated that GNC hydrogel could act as an ideal pH-monitoring and oral drug delivery system in near-neutral pH at the same time.
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Affiliation(s)
| | - Madhab Dule
- Materials Science Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Raj Paul
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Jyotirmayee Dash
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Md Anas
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Tarun Kumar Mandal
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Poushali Das
- School of Nano Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Narayan Chandra Das
- School of Nano Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.,Rubber Technology Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Susanta Banerjee
- School of Nano Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.,Materials Science Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
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Ghosh SK, Das TK, Ghosh S, Ganguly S, Nath K, Das NC. Physico‐mechanical, rheological and gas barrier properties of organoclay and inorganic phyllosilicate reinforced thermoplastic films. J Appl Polym Sci 2020. [DOI: 10.1002/app.49735] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Suman Kumar Ghosh
- Rubber Technology Centre Indian Institute of Technology Kharagpur India
| | - Tushar Kanti Das
- Rubber Technology Centre Indian Institute of Technology Kharagpur India
| | - Sabyasachi Ghosh
- Rubber Technology Centre Indian Institute of Technology Kharagpur India
| | - Sayan Ganguly
- Department of Chemistry, Institute of Nanotechnology and Advanced Materials Bar Ilan University Ramat‐Gan Israel
| | - Krishnendu Nath
- Rubber Technology Centre Indian Institute of Technology Kharagpur India
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Remanan S, Ghosh S, Das TK, Sharma M, Bose M, Bose S, Das AK, Das NC. Gradient crystallinity and its influence on the poly(vinylidene fluoride)/poly(methyl methacrylate) membrane‐derived by immersion precipitation method. J Appl Polym Sci 2020. [DOI: 10.1002/app.48677] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Sanjay Remanan
- Rubber Technology Centre Indian Institute of Technology Kharagpur 721302 India
| | - Sabyasachi Ghosh
- Rubber Technology Centre Indian Institute of Technology Kharagpur 721302 India
| | - Tushar Kanti Das
- Rubber Technology Centre Indian Institute of Technology Kharagpur 721302 India
| | - Maya Sharma
- Soft Matter Rheology and Technology Division, Department of Chemical Engineering KU Leuven Leuven 3001 Belgium
| | - Madhuparna Bose
- Department of Biotechnology Indian Institute of Technology Kharagpur 721302 India
| | - Suryasarathi Bose
- Department of Materials Engineering Indian Institute of Science Bangalore 560012 India
| | - Amit Kumar Das
- Department of Biotechnology Indian Institute of Technology Kharagpur 721302 India
| | - Narayan Chandra Das
- Rubber Technology Centre Indian Institute of Technology Kharagpur 721302 India
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Das P, Ganguly S, Maity PP, Srivastava HK, Bose M, Dhara S, Bandyopadhyay S, Das AK, Banerjee S, Das NC. Converting waste Allium sativum peel to nitrogen and sulphur co-doped photoluminescence carbon dots for solar conversion, cell labeling, and photobleaching diligences: A path from discarded waste to value-added products. Journal of Photochemistry and Photobiology B: Biology 2019; 197:111545. [DOI: 10.1016/j.jphotobiol.2019.111545] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 06/16/2019] [Accepted: 06/28/2019] [Indexed: 02/07/2023]
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Maity PP, Dutta D, Ganguly S, Kapat K, Dixit K, Chowdhury AR, Samanta R, Das NC, Datta P, Das AK, Dhara S. Isolation and mass spectrometry based hydroxyproline mapping of type II collagen derived from Capra hircus ear cartilage. Commun Biol 2019; 2:146. [PMID: 31044171 PMCID: PMC6488623 DOI: 10.1038/s42003-019-0394-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 03/18/2019] [Indexed: 11/19/2022] Open
Abstract
Collagen II (COLII), the most abundant protein in vertebrates, helps maintain the structural and functional integrity of cartilage. Delivery of COLII from animal sources could improve cartilage regeneration therapies. Here we show that COLII can be purified from the Capra ear cartilage, a commonly available bio-waste product, with a high yield. MALDI-MS/MS analysis evidenced post-translational modifications of the signature triplet, Glycine-Proline-Hydroxyproline (G-P-Hyp), in alpha chain of isolated COLII (COLIIA1). Additionally, thirty-two peptides containing 59 Hyp residues and a few G-X-Y triplets with positional alterations of Hyp in COLIIA1 are also identified. Furthermore, we show that an injectable hydrogel formulation containing the isolated COLII facilitates chondrogenic differentiation towards cartilage regeneration. These findings show that COLII can be isolated from Capra ear cartilage and that positional alteration of Hyp in its structural motif, as detected by newly developed mass spectrometric method, might be an early marker of cartilage disorder.
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Affiliation(s)
- Priti Prasanna Maity
- School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, 721302 India
- Centre for Healthcare Science and Technology, Indian Institute of Engineering Science and Technology, Shibpur, Howrah, 711103 India
| | - Debabrata Dutta
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, 721302 India
| | - Sayan Ganguly
- Rubber Technology Centre, Indian Institute of Technology Kharagpur, Kharagpur, 721302 India
| | - Kausik Kapat
- School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, 721302 India
| | - Krishna Dixit
- School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, 721302 India
| | - Amit Roy Chowdhury
- Centre for Healthcare Science and Technology, Indian Institute of Engineering Science and Technology, Shibpur, Howrah, 711103 India
| | - Ramapati Samanta
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, 721302 India
| | - Narayan Chandra Das
- Rubber Technology Centre, Indian Institute of Technology Kharagpur, Kharagpur, 721302 India
| | - Pallab Datta
- Centre for Healthcare Science and Technology, Indian Institute of Engineering Science and Technology, Shibpur, Howrah, 711103 India
| | - Amit Kumar Das
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, 721302 India
| | - Santanu Dhara
- School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, 721302 India
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Das P, Ganguly S, Banerjee S, Das NC. Graphene based emergent nanolights: a short review on the synthesis, properties and application. Res Chem Intermed 2019. [DOI: 10.1007/s11164-019-03823-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Das P, Ganguly S, Bose M, Ray D, Ghosh S, Mondal S, Aswal VK, Das AK, Banerjee S, Das NC. Surface quaternized nanosensor as a one-arrow-two-hawks approach for fluorescence turn “on–off–on” bifunctional sensing and antibacterial activity. NEW J CHEM 2019. [DOI: 10.1039/c8nj06308g] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The hydrothermal synthesis of κ-carrageenan and lemon juice derived carbon dots and their application in a fluorescence sensor for Cr(vi) and ascorbic acid are demonstrated.
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Affiliation(s)
- Poushali Das
- School of Nanoscience and Technology
- Indian Institute of Technology
- Kharagpur 721302
- India
| | - Sayan Ganguly
- Rubber Technology Centre
- Indian Institute of Technology
- Kharagpur 721302
- India
| | - Madhuparna Bose
- Department of Biotechnology
- Indian Institute of Technology
- Kharagpur 721302
- India
| | - Debes Ray
- Solid State Physics Division
- Bhabha Atomic Research Centre
- Mumbai 400085
- India
| | - Sabyasachi Ghosh
- Rubber Technology Centre
- Indian Institute of Technology
- Kharagpur 721302
- India
| | - Subhadip Mondal
- Rubber Technology Centre
- Indian Institute of Technology
- Kharagpur 721302
- India
| | - Vinod K. Aswal
- Solid State Physics Division
- Bhabha Atomic Research Centre
- Mumbai 400085
- India
| | - Amit Kumar Das
- Department of Biotechnology
- Indian Institute of Technology
- Kharagpur 721302
- India
| | - Susanta Banerjee
- School of Nanoscience and Technology
- Indian Institute of Technology
- Kharagpur 721302
- India
- Materials Science Centre
| | - Narayan Chandra Das
- School of Nanoscience and Technology
- Indian Institute of Technology
- Kharagpur 721302
- India
- Rubber Technology Centre
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Affiliation(s)
- Poushali Das
- School of Nanoscience and Technology; Indian Institute of Technology; Kharagpur 721302 West Bengal India
| | - Madhuparna Bose
- Department of Biotechnology; Indian Institute of Technology; Kharagpur 721302 West Bengal India
| | - Amit Kumar Das
- Department of Biotechnology; Indian Institute of Technology; Kharagpur 721302 West Bengal India
| | - Susanta Banerjee
- Materials Science Centre; Indian Institute of Technology; Kharagpur 721302 West Bengal India
| | - Narayan Chandra Das
- School of Nanoscience and Technology; Indian Institute of Technology; Kharagpur 721302 West Bengal India
- Rubber Technology Centre; Indian Institute of Technology; Kharagpur 721302 West Bengal India
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Manoharan P, Anagha MG, Das NC, Naskar K. INFLUENCE OF DIFFERENT SPECIFIC SURFACE AREA OF HIGHLY DISPERSIBLE SILICA AND INTERFACIAL CHARACTERISTICS OF GREEN ELASTOMER COMPOSITES. Rubber Chemistry and Technology 2018. [DOI: 10.5254/rct-18-82632] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
ABSTRACT
Epoxidized natural rubber (ENR) is a modified form of NR bearing polar epoxy groups. The focus is on dispersion of highly dispersible silica (HDS) filler with three different specific surface areas in ENR 25/ENR 50 composites. The effect of three different specific surface areas of HDS on bound rubber content, Payne effect, physicomechanical properties, and viscoelastic properties of the green composites was studied in detail. Also, the influences of epoxide content in ENRs in the absence of silane coupling agent are evaluated on the overall properties of green composites. The highest level of reinforcement was obtained for the intermediate specific surface area of HDS due to the homogenous dispersion in the ENR matrix. Small-angle X-ray scattering (SAXS) has been used to analyze the particle network and cluster establishment in the green composites. The present SAXS method provides a unique insight into the aggregate formation according to the Beaucage model. On the other hand, SAXS results demonstrate that the particle network can be efficiently suppressed by increasing the specific surface area of HDS.
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Affiliation(s)
- Partheban Manoharan
- Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302, India
| | - M. G. Anagha
- Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302, India
| | - Narayan Chandra Das
- Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302, India
| | - Kinsuk Naskar
- Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302, India
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Das P, Bose M, Ganguly S, Mondal S, Das AK, Banerjee S, Das NC. Green approach to photoluminescent carbon dots for imaging of gram-negative bacteria Escherichia coli. Nanotechnology 2017; 28:195501. [PMID: 28417900 DOI: 10.1088/1361-6528/aa6714] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Fluorescent carbon dots, zero-dimensional nanomaterials with surface ligands, have been studied extensively over the past few years in biolabelling or fluorescence-based live cell assays. In the past, synthetic organic dyes have been used as cell tracking materials, but they have severe limitations; fluorescent carbon dots may pave the way to biolabelling and cell imaging. In this work, green fluorescent carbon dots have been synthesized from a green source, gram, without any sort of covalent or ionic modifications. These gram-derived carbon dots are unique with respect to synthetic commercial cell-tracking dyes as they are non-toxic, cell internalization occurs quickly, and they have excellent bioconjugation with bacterial cells. Our aim is to establish these carbon dots in a biolabelling assay with its other physicochemical features like the tunable luminescence property, high degree of water solubility and low toxicity, towards various environments (wide range of pH, high ionic strength). Our study introduces a new perspective on the commercialization of carbon dots as a potential alternative to synthetic organic dyes for fluorescence-based cell-labelling assays.
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Affiliation(s)
- Poushali Das
- School of Nanoscience and Technology, Indian Institute of Technology, Kharagpur 721302, India
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Manoharan P, Chandra Das N, Naskar K. On-demand tuned hazard free elastomeric composites: A green approach. Biopolymers 2017; 107. [PMID: 28369686 DOI: 10.1002/bip.23019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 03/03/2017] [Accepted: 03/23/2017] [Indexed: 11/11/2022]
Abstract
Rising ecological concerns and depletion of the potentially harmful environmental impacts caused by rubber products, are of prime importance in the industry. Therefore, implementation of sustainable greener materials is required to minimize the detrimental influences. In this research, we investigated the beneficial influence of naturally derived bio-resin toward the effects of association with Zinc Oxide Nanoparticles in highly dispersible silica (HDS) reinforced Natural rubber (NR)/Epoxidized Natural Rubber (ENR)-based composites. This novel green composite offers impressive properties which were analyzed based on bound rubber content, transmission electron microscopy, physico-mechanical, dynamic mechanical, and cure characteristics. Nanoindentation studies demonstrated the enhanced hysteresis phenomenon of the green composites. The small angle X-ray scattering (SAXS) characterization has been studied by using a Beaucage model and results corroborates that the insertion of bio-resin exhibits ameliorated state of silica dispersion in the green composites. Overall, the study with the bio-resin has provided the impetus in employing it as an alternative to the expensive synthetic route of silane coupling agent and toxic process oil.
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Affiliation(s)
- Partheban Manoharan
- Indian Institute of Technology, Rubber Technology Centre, Kharagpur, 721302, India
| | - Narayan Chandra Das
- Indian Institute of Technology, Rubber Technology Centre, Kharagpur, 721302, India
| | - Kinsuk Naskar
- Indian Institute of Technology, Rubber Technology Centre, Kharagpur, 721302, India
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Das P, Ganguly S, Bose M, Mondal S, Das AK, Banerjee S, Das NC. A simplistic approach to green future with eco-friendly luminescent carbon dots and their application to fluorescent nano-sensor 'turn-off' probe for selective sensing of copper ions. Mater Sci Eng C Mater Biol Appl 2017; 75:1456-1464. [PMID: 28415437 DOI: 10.1016/j.msec.2017.03.045] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 03/04/2017] [Indexed: 12/11/2022]
Abstract
Zero-dimensional fluorescent nanoparticles having specificity as molecular probe appears to be strategically balanced fluorescent nano-probes. In this work, purified lemon extract and l-arginine have been thermally coupled for the extremely acute detection of Cu2+ in aqueous medium. The Cu2+ ions may be captured by the amino groups on the surface of the nano-sensor to form cupric ammine complex resulting in quenched fluorescence via an inner filter effect. Our proposed nano-probe is N-doped carbon dots (NCDs) which are efficiently selective as fluorescent chemosensor due to enormous binding affinity towards Cu2+ in a wide range of concentration (0.05-300μM) within a few minutes.
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Affiliation(s)
- Poushali Das
- School of Nanoscience and Technology, Indian Institute of Technology, Kharagpur 721302, India
| | - Sayan Ganguly
- Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302, India
| | - Madhuparna Bose
- Department of Biotechnology, Indian Institute of Technology, Kharagpur 721302, India
| | - Subhadip Mondal
- Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302, India
| | - Amit Kumar Das
- Department of Biotechnology, Indian Institute of Technology, Kharagpur 721302, India
| | - Susanta Banerjee
- Materials Science Centre, Indian Institute of Technology, Kharagpur 721302, India
| | - Narayan Chandra Das
- School of Nanoscience and Technology, Indian Institute of Technology, Kharagpur 721302, India; Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302, India.
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Hossain MI, Das NC, Bhattacharjee P, Ahamad MSU, Rahman Z. Colonic adenocarcinoma with coexisting tuberculosis: an unusual presentation. Bangladesh J Med Sci 2016. [DOI: 10.3329/bjms.v15i1.27173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Tuberculosis affecting the colon is an uncommon extra-pulmonary form of the disease, and its association with malignancy is highly unusual. A 66-year man presented with lower gastrointestinal bleeding altered bowel habit and significant weight loss. On examination, he had ulcer infiltrative growth in the descending colon, with friable mucosa, bleeds easily on touch. With the diagnosis of carcinoma of the descending colon, he underwent left hemicolectomy. The histopathological examination revealed carcinoma colon with coexisting tuberculosis. The aetiological association between the tuberculosis and colon cancer is a matter of debate. However, the treating surgeon should be aware of this association, to avoid confusion and delay in the management.Bangladesh Journal of Medical Science Vol.15(1) 2016 p.131-134
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Ganguly S, Das NC. Chlorosulphonated Polyethylene and Its Composites for Electronic Applications. Flexible and Stretchable Electronic Composites 2016. [DOI: 10.1007/978-3-319-23663-6_8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Ganguly S, Das NC. A comparison on self-seeding and isothermal crystallization of polyethylene in solution using small angle neutron scattering. POLYMER 2015. [DOI: 10.1016/j.polymer.2015.02.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Chattopadhyay PK, Praveen S, Chandra Das N, Chattopadhyay S. Contribution of organomodified clay on hybrid microstructures and properties of epoxidized natural rubber-based nanocomposites. POLYM ENG SCI 2012. [DOI: 10.1002/pen.23339] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Zhang J, Kumbhar A, He J, Das NC, Yang K, Wang JQ, Wang H, Stokes KL, Fang J. Simple Cubic Super Crystals Containing PbTe Nanocubes and Their Core−Shell Building Blocks. J Am Chem Soc 2008; 130:15203-9. [DOI: 10.1021/ja806120w] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jun Zhang
- Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902, Electron Microscope Facility, Clemson University, Anderson, South Carolina 29625, Coordinated Instrumentation Facility, Tulane University, New Orleans, Louisiana 70118, Department of Mechanical Engineering, State University of New York at Binghamton, Binghamton, New York 13902, Department of Physics, State University of New York at Binghamton, Binghamton, New York 13902, and Department of Physics, University
| | - Amar Kumbhar
- Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902, Electron Microscope Facility, Clemson University, Anderson, South Carolina 29625, Coordinated Instrumentation Facility, Tulane University, New Orleans, Louisiana 70118, Department of Mechanical Engineering, State University of New York at Binghamton, Binghamton, New York 13902, Department of Physics, State University of New York at Binghamton, Binghamton, New York 13902, and Department of Physics, University
| | - Jibao He
- Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902, Electron Microscope Facility, Clemson University, Anderson, South Carolina 29625, Coordinated Instrumentation Facility, Tulane University, New Orleans, Louisiana 70118, Department of Mechanical Engineering, State University of New York at Binghamton, Binghamton, New York 13902, Department of Physics, State University of New York at Binghamton, Binghamton, New York 13902, and Department of Physics, University
| | - Narayan Chandra Das
- Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902, Electron Microscope Facility, Clemson University, Anderson, South Carolina 29625, Coordinated Instrumentation Facility, Tulane University, New Orleans, Louisiana 70118, Department of Mechanical Engineering, State University of New York at Binghamton, Binghamton, New York 13902, Department of Physics, State University of New York at Binghamton, Binghamton, New York 13902, and Department of Physics, University
| | - Kaikun Yang
- Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902, Electron Microscope Facility, Clemson University, Anderson, South Carolina 29625, Coordinated Instrumentation Facility, Tulane University, New Orleans, Louisiana 70118, Department of Mechanical Engineering, State University of New York at Binghamton, Binghamton, New York 13902, Department of Physics, State University of New York at Binghamton, Binghamton, New York 13902, and Department of Physics, University
| | - Jian-Qing Wang
- Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902, Electron Microscope Facility, Clemson University, Anderson, South Carolina 29625, Coordinated Instrumentation Facility, Tulane University, New Orleans, Louisiana 70118, Department of Mechanical Engineering, State University of New York at Binghamton, Binghamton, New York 13902, Department of Physics, State University of New York at Binghamton, Binghamton, New York 13902, and Department of Physics, University
| | - Howard Wang
- Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902, Electron Microscope Facility, Clemson University, Anderson, South Carolina 29625, Coordinated Instrumentation Facility, Tulane University, New Orleans, Louisiana 70118, Department of Mechanical Engineering, State University of New York at Binghamton, Binghamton, New York 13902, Department of Physics, State University of New York at Binghamton, Binghamton, New York 13902, and Department of Physics, University
| | - Kevin L. Stokes
- Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902, Electron Microscope Facility, Clemson University, Anderson, South Carolina 29625, Coordinated Instrumentation Facility, Tulane University, New Orleans, Louisiana 70118, Department of Mechanical Engineering, State University of New York at Binghamton, Binghamton, New York 13902, Department of Physics, State University of New York at Binghamton, Binghamton, New York 13902, and Department of Physics, University
| | - Jiye Fang
- Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902, Electron Microscope Facility, Clemson University, Anderson, South Carolina 29625, Coordinated Instrumentation Facility, Tulane University, New Orleans, Louisiana 70118, Department of Mechanical Engineering, State University of New York at Binghamton, Binghamton, New York 13902, Department of Physics, State University of New York at Binghamton, Binghamton, New York 13902, and Department of Physics, University
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Das NC, Hikosaka M, Okada K, Toda A, Inoue K. Nucleation and size distribution of nucleus during induction period of polyethylene crystallization. J Chem Phys 2007; 123:204906. [PMID: 16351316 DOI: 10.1063/1.2128703] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The crystallization process from supercooled melt results in the formation of nanosize nuclei in the earlier stage (induction period) through subsequent attachment or detachment of repeating unit to nuclei. The size distribution of nucleus f(N(j),t) in the induction period of nucleation process from the melts has not been experimentally confirmed yet by direct observation. The reason is that the number density of nuclei nu is too small to be detected experimentally. In our previous work, we showed the direct evidence of nucleation experimentally by means of small angle x-ray scattering (SAXS) technique. Further we have succeeded to observe the nucleation and f(N(j),t) of polymer crystallization from the melts by SAXS using synchrotron radiation. We increased nu by adding a nucleating agent to a polymer (polyethylene). The time evolution of f(N(j),t) was observed for the first time.
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Affiliation(s)
- Narayan Chandra Das
- Materials Science and Engineering, Michigan Technological University, Houghton, MI 49931, USA.
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Sharma P, Vatsa RK, Rajasekhar BN, Das NC, Ghanty TK, Kulshreshtha SK. Photoionization of CH(3)I mediated by the C state in the visible and ultraviolet regions. Rapid Commun Mass Spectrom 2005; 19:1522-8. [PMID: 15880668 DOI: 10.1002/rcm.1951] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Three/two-photon resonant multiphoton ionization (MPI) of the CH3I monomer has been studied in the gas phase at 532 and 355 nm using time-of-flight mass spectrometry. Under low laser intensity (approximately 10(9) W/cm2) the mass spectra showed peaks at m/z 15, 127 and 142, corresponding to [CH3]+, [I]+ and [CH3I]+ species, at both these wavelengths. The laser power dependence for [CH3I]+, [I]+ and [CH3]+ ions showed a three-photon dependence at 532 nm. For the same three ions, photoionization studies at 355 nm gave a power dependence of 2. Both these results suggest that a vibronic energy level at approximately 7 eV, lying in the Rydberg C state, acts as a resonant intermediate level in ionization of CH3I. In the case of 355 nm, with increasing intensity additional peaks at m/z 139 and 141 were observed which could be assigned to [CI]+ and [CH2I]+ fragments. In contrast, for high intensity radiation at 532 nm ( approximately 2 x 10(10) W/cm2), only the [CI]+ fragment was observed. At these wavelengths, fragment ions observed in mass spectra mainly arise from photodissociation of the parent ion. Experiments at another wavelength in the visible region (564.2 nm) confirmed the results obtained at 532 nm. In order to assess the role of the A state in these MPI experiments, additional experiments were performed at 266 and 282.1 nm, which access the A state directly via a one-photon transition, and showed absence of a surviving precursor ion. Reaction energies for various possible dissociation channels of CH3I/[CH3I]+/[CH2I]+ were calculated theoretically at the MP2 level using the GAMESS electronic structure program.
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Affiliation(s)
- P Sharma
- Novel Materials and Structural Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India
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Das NC, Yamazaki S, Hikosaka M, Chaki TK, Khastgir D, Chakraborty A. Electrical conductivity and electromagnetic interference shielding effectiveness of polyaniline-ethylene vinyl acetate composites. POLYM INT 2004. [DOI: 10.1002/pi.1660] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Bhattacharyya D, Sahoo NK, Thakur S, Das NC. Characterization of a multilayer highly reflecting mirror by spectroscopic phase-modulated ellipsometry. Appl Opt 2001; 40:1707-1714. [PMID: 18357168 DOI: 10.1364/ao.40.001707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The characterization of optical multilayer coatings has been a challenging task for thin-film scientists and engineers because of the various complex, interdependent layer parameters that exist in the system. Spectroscopic phase-modulated ellipsometry has some advantages in the postanalysis of the layer parameters of such multilayer coatings because it suitably models the layer structure with respect to the ellipsometric measurements. An algorithm to characterize multilayer optical coatings with large numbers of layers has been described by spectroscopic ellipsometry by use of a discrete spectral zone fitting approach. A 23-layer multilayer highly reflecting mirror has been characterized by this technique in the wavelength range 280-1000 nm. The ellipsometric spectra (? and D versus wavelength) have been fitted separately in three wavelength regimes. Fitting the ellipsometric spectra in the wavelength regime of 700-1000 nm permitted the sample structure to be determined. The data were then fitted in the wavelength range 280-340 nm, i.e., near the fundamental absorption edge of TiO(2), to yield the dispersion relation for the optical constants of TiO(2). Finally, the data were fitted in the wavelength range 340-700 nm, and the true dispersion of the refractive index of TiO(2), along with the best-fitting sample structure, was obtained.
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Das NC, Madden RP, Seyoum HM. Image Evaluation of the High Resolution VUV Spectrometer at SURF II by Ray Tracing. J Res Natl Inst Stand Technol 1998; 103:483-495. [PMID: 28009381 PMCID: PMC4889313 DOI: 10.6028/jres.103.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 05/11/1998] [Indexed: 06/06/2023]
Abstract
A high resolution VUV spectroscopic facility has been in use for several years at SURF II, the Synchrotron Ultraviolet Radiation Facility at the National Institute of Standards and Technology in Gaithersburg, Maryland. At this facility, a combination of three cylindrical mirrors is utilized to focus the light originating in the storage ring onto the horizontal entrance slit of the spectrometer. The spectrometer uses a 6.65 m concave grating having a groove density of 4800 lines/mm in the off-plane Eagle mounting. In preparation for the installation of an array detector in the exit image plane, a ray tracing program has been formulated and spot diagrams have been constructed by plotting the coordinates of the points of intersection of the diffracted rays with the image plane, which is tangent to the Rowland circle. In creating the spot diagrams, we have considered both parallel and tilted configurations of the entrance slit with respect to the grating grooves. It is shown that the line widths of the spectral images can be reduced when the entrance slit is properly tilted. Finally, we have estimated the spectral widths of the images when they are recorded on an array detector placed tangent to the Rowland circle. We conclude that an image spectral width of 0.41 pm to 0.88 pm in first order can be achieved over the wavelength region of 40 nm to 120 nm.
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Affiliation(s)
- N C Das
- Spectroscopy Division, Bhabha Atomic Research Center, Bombay2400 085, India
| | - R P Madden
- National Institute of Standards and Technology, Gaithersburg, MD 20899-0001
| | - H M Seyoum
- Department of Physics, University of the District of Columbia, Washington, DC 20008
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Das S, Das NC. Theory of hole superconductivity. II. Phys Rev B Condens Matter 1994; 50:4131-4138. [PMID: 9976697 DOI: 10.1103/physrevb.50.4131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Das S, Das NC. Erratum: Theory of hole superconductivity. Phys Rev B Condens Matter 1994; 49:752. [PMID: 10021604 DOI: 10.1103/physrevb.49.752.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Das NC, Padhi AK, Bandyopadhyay M. A design of a vermiculite column adsorber for the removal of lead from water. Environ Pollut 1993; 80:129-132. [PMID: 15091855 DOI: 10.1016/0269-7491(93)90138-e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/1991] [Accepted: 02/17/1992] [Indexed: 05/24/2023]
Abstract
Mini-column techniques were employed to determine the mass transfer coefficient for lead adsorption onto vermiculite. Variation of the mass transfer coefficient with flow rate, particle size of sorbent, and influent lead concentration were studied. Multiple linear regression (MLR) analysis showed that the mass transfer coefficient varied as the 0.43 power of the liquid flow rate and inversely as the 0.272 power of particle diameter of the vermiculite, but was independent of the influent concentration of lead. Different parameters of a fixed bed column design for the removal of lead by vermiculite were determined using the data from the batch sorption study. The performance of the liquid bed column in removing lead was in close agreement with predicted performance using the batch isotherm data.
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Affiliation(s)
- N C Das
- Civil Engineering Dept, Bangladesh Institute of Technology, Dhaka, Gazipur-1700, Bangladesh
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Das NC, Madden RP, Olson WB, Seyoum HM. Theoretical evaluation of the high-resolution vacuum ultraviolet spectrometer on SURF II. Appl Opt 1992; 31:6724-6733. [PMID: 20733905 DOI: 10.1364/ao.31.006724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The high-resolution vacuum-ultraviolet spectroscopic facility at SURF II, the Synchrotron Ultraviolet Radiation Facility at the National Institute of Standards and Technology in Gaithersburg, Md., consists of a fore-optics system of three cylindrical mirrors and a 6.65-m concave grating spectrometer using the off-plane Eagle mounting. To prepare for the evaluation of the actual performance of this nationalfacility spectrometer against theoretical expectations, we computed scanning parameters, spectral resolution, and the optimum curvature and tilt of both entrance and exit slits. It is planned eventually to replace the exit slit of this instrument with a two-dimensional array detector to increase data collection efficiency. Therefore a major motivation for this work is that the results on the tilt and curvature of the exit slit can be used to maximize the resolution obtainable with the array detector through data processing.
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Sahu T, Das NC. Bond-angle disorder effects on the magnetic susceptibility of amorphous semiconductors. Phys Rev B Condens Matter 1992; 45:13336-13344. [PMID: 10001416 DOI: 10.1103/physrevb.45.13336] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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37
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Das NC. Vital rates of India for intercensal period with declining fertility and declining mortality. Genus 1992; 48:199-215. [PMID: 12317868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2023] Open
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38
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Abstract
In this paper I discuss the construction and the aberration properties of plane-holographic diffraction gratings in a Czerny-Turner mounting. A ray-tracing scheme has been formulated for computing the aberrations of the system. It has been found that in the area near the recording wavelength for the holographic grating, the system has better resolution than does a conventional grating system. The design parameters of a medium-sized holographic grating spectrograph are specified. The performance of the spectrograph is evaluated by plotting spot diagrams, which show that astigmatic defects are much reduced.
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Das NC. Preservation of health of nurses with special reference to mental health. Nurs J India 1991; 82:121. [PMID: 1852652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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40
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Das NC. A note on the estimation of marriage rate from census data. Genus 1989; 45:143-51. [PMID: 12283192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2023] Open
Abstract
"The level and trend in nuptiality for the developing countries can not be studied because necessary data are not available. A broad idea of the trend is obtained by examining the never-married proportion for different age cohorts at different censuses. In this paper, a methodology for estimating age-specific marriage rates from census data is presented." (SUMMARY IN FRE AND ITA)
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Das NC. Mental hygiene and the environment. Nurs J India 1989; 80:143-4. [PMID: 2616338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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42
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Panigrahi S, Das NC. Effect of spin scattering and magnetic order on the electronic heat capacity of magnetic superconductors. Phys Rev B Condens Matter 1987; 35:4781-4786. [PMID: 9940650 DOI: 10.1103/physrevb.35.4781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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43
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Das NC. Studies on personality profile with special reference to nursing. Nurs J India 1986; 77:321-2. [PMID: 3646680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Raina VK, Singh H, Das NC. Prevalence of intestinal parasitic infection in some urban localities of Solan District, Himachal Pradesh. J Commun Dis 1984; 16:157-9. [PMID: 6491235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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45
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Russel S, Das NC, Ray JK, Rao CK. Prevalence of intestinal parasitic infection in selected railway colonies of Tamil Nadu. J Commun Dis 1983; 15:65-7. [PMID: 6677690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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46
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Paul RC, Das NC, John VM, Rao CK. Prevalence of intestinal parasitic infection in selected rural population of Arunachal Pradesh. J Commun Dis 1982; 14:309-12. [PMID: 7184958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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47
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Paul RC, Das NC, Rao CK, Joshi M, Mathur AB. Prevalence of intestinal parasites in three villages of Dungarpur district, Rajasthan. J Commun Dis 1982; 14:149-51. [PMID: 7153483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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48
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Das NC, Apparao MC, Venkatasubbaiah N, Rao CK. Prevalence of intestinal parasites in rural population of West Godavari District, Andhra Pradesh. J Commun Dis 1981; 13:165-171. [PMID: 7343601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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49
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Das NC, Russel S, Trivedi GK, Joshi VK, Rao CK. Prevalence of intestinal parasites in Jamnagar and Okha towns--Gujarat. J Commun Dis 1981; 13:67-70. [PMID: 7320492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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50
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Das NC, Rao CK, Kumar S, Ganguly P. Prevalence of intestinal parasites in a special camp in Tripura. J Commun Dis 1980; 12:169-70. [PMID: 7229316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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