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Nagmani, Manna S, Puravankara S. Hierarchically porous closed-pore hard carbon as a plateau-dominated high-performance anode for sodium-ion batteries. Chem Commun (Camb) 2024; 60:3071-3074. [PMID: 38389498 DOI: 10.1039/d4cc00025k] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
Micro-spherical hard carbons (MSHCs) with distinct porosity features have been synthesized from an easy microwave-assisted solvothermal pre-treatment of sucrose, followed by carbonization, as anodes for sodium-ion batteries. The MSHC exhibits large interlayer spacing of turbostratic graphene nanosheets with more defective graphene planes, hierarchical pore structures, and closed pores. The MSHC anode delivered a high reversible capacity of 422 mA h g-1 at 0.1C rate with a low-potential battery-like plateau contribution of 57%, which is the best reported reversible sodium storage performance to date for an unmodified HC for SIBs. The MSHC shows 251 and 140 mA h g-1 high-rate capacities at 1C and 5C, respectively, with excellent capacity retention of 84% after 500 cycles at 1C. GITT and EPR measurements confirm the storage mechanism shift from intercalation to the quasi-metallic sodium clusters in the closed pores at low potentials. The full cell with the MSHC anode and a P2-Na0.67Ni0.33Mn0.67O2 (NNMO) cathode delivered a high energy density of 292 W h kg-1 at a working potential of 3.2 V.
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Affiliation(s)
- Nagmani
- School of Energy Science and Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India.
- Centre for Nanomaterials, International Advanced Research Centre for Powder Metallurgy and New Materials, Hyderabad 500005, Telangana, India
| | - S Manna
- School of Energy Science and Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India.
| | - S Puravankara
- School of Energy Science and Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India.
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Guin S, Halder SC, Manna S, Jana AD. Quantifying plasmonic characteristics of pure and alkali doped aluminium clusters. J Mol Graph Model 2024; 127:108690. [PMID: 38056171 DOI: 10.1016/j.jmgm.2023.108690] [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] [Received: 06/21/2023] [Revised: 11/15/2023] [Accepted: 11/28/2023] [Indexed: 12/08/2023]
Abstract
Study of plasmonic response of molecules and metal nanoclusters have drawn a considerable attention during recent times due to their various practical applications. In this study, the optical properties and the plasmonic response of our recently reported Al13+ cluster [Guin et al. Journal of Molecular Graphics and Modelling, 2020, 97, 107544] and its alkali doped counterparts [Guin et al. Journal of Molecular Modeling, 2021, 27, 235] have been investigated based on Transition dipole moment (TDM), Natural Transition Orbital (NTO) and transition inverse participation ratio (TIPR) indices. Recently these indices have been utilized by various scientists to characterize plasmonic transitions of molecular systems and metal nanoclusters. In TDM analysis, the magnitude of all the contributing TDMs associated with the molecular orbital transitions have been estimated along with the angles the individual dipoles make with the resultant dipole moment vector. A transition having at least two dominating TDM contributions along with phase matching indicate a collective or plasmonic transition. The collectiveness of orbital transitions is also corroborated through NTO and TIPR analysis. The effect of solvent medium on the optical properties and plasmonic transitions have also been studied using time dependent density functional theory in the conductor like polarizable continuum model (TDDFT-CPCM). The solvent has a strong impact on the optical properties as well as the plasmonic response of the clusters. The dielectric environment of the solvent red shifts and broadens the spectra with respect to that in the gas phase. Plasmon like excitations have been found for Li doped Al13+ cluster without solvent and Na doped Al13+ cluster in ethanol and THF.
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Affiliation(s)
- Surajit Guin
- Department of Physics, Behala College, Parnasree, Kolkata, 700060, West Bengal, India
| | - Sasthi Charan Halder
- Department of Physics, Behala College, Parnasree, Kolkata, 700060, West Bengal, India
| | - Shovan Manna
- Department of Physics, Behala College, Parnasree, Kolkata, 700060, West Bengal, India
| | - Atish Dipankar Jana
- Department of Physics, Behala College, Parnasree, Kolkata, 700060, West Bengal, India; Institute of Astronomy Space and Earth Sciences, P-177, CIT Road, Scheme 7m, Ultadanga station, Kolkata, 700054, India.
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Roy AS, Banerjee K, Roy P, Shil R, Ravishankar R, Datta R, Sen A, Manna S, Ghosh TK, Mukherjee G, Rana TK, Kundu S, Nayak SS, Pandey R, Paul D, Atreya K, Basu S, Mukhopadhyay S, Pandit D, Kulkarni MS, Bhattacharya C. Measurement of energy and directional distribution of neutron ambient dose equivalent for the 7Li(p,n) 7Be reaction. Appl Radiat Isot 2024; 204:111140. [PMID: 38070360 DOI: 10.1016/j.apradiso.2023.111140] [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] [Received: 03/14/2023] [Revised: 11/13/2023] [Accepted: 12/02/2023] [Indexed: 12/31/2023]
Abstract
Double differential neutron fluence distributions were measured in the 7Li(p,n)7Be reaction for proton beam energies 7, 9 and 12 MeV. Seven liquid scintillator based detectors were employed to measure neutron fluence distributions using the Time of Flight technique. Neutron ambient dose equivalents were determined from the measured fluence distribution using ICRP (International Commission on Radiological Protection) recommended fluence to dose equivalent conversion coefficients. Neutron dose equivalents were also measured using a conventional BF3 detector based REM counter. Ambient dose equivalent measured by the REM counter is found to be in agreement with that determined from the neutron fluence spectra within their uncertainties. Angular distributions of the ambient dose equivalents were also determined from the measured fluence distributions at different angles.
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Affiliation(s)
- A S Roy
- Health Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India; Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | - K Banerjee
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India; Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064, India.
| | - Pratap Roy
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India; Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064, India
| | - R Shil
- Visva Bharati University, Santiniketan, Bolpur, West Bengal 731235, India
| | - R Ravishankar
- Health Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - R Datta
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India; RP&AD, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - A Sen
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India; Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064, India
| | - S Manna
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India; Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064, India
| | - T K Ghosh
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India; Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064, India
| | - G Mukherjee
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India; Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064, India
| | - T K Rana
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India; Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064, India
| | - S Kundu
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India; Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064, India
| | - S S Nayak
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India; Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064, India
| | - R Pandey
- Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064, India
| | - D Paul
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India; Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064, India
| | - K Atreya
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India; Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064, India
| | - S Basu
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India; Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064, India
| | - S Mukhopadhyay
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India; Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064, India
| | - Deepak Pandit
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India; Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064, India
| | - M S Kulkarni
- Health Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India; Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | - C Bhattacharya
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India; Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064, India
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Pofelski A, Deng S, Yu H, Park TJ, Jia H, Manna S, Chan MKY, Sankaranarayanan SKR, Ramanathan S, Zhu Y. Dopant Mapping of Partially Hydrogenated Vanadium Dioxide using the Energy Loss Near Edge Structure Technique. Microsc Microanal 2023; 29:1667-1668. [PMID: 37613910 DOI: 10.1093/micmic/ozad067.858] [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] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- A Pofelski
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, USA
| | - S Deng
- School of Materials Engineering, Purdue University, West Lafayette, IN, USA
| | - H Yu
- School of Materials Engineering, Purdue University, West Lafayette, IN, USA
| | - T J Park
- School of Materials Engineering, Purdue University, West Lafayette, IN, USA
| | - H Jia
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, IL, USA
| | - S Manna
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, IL, USA
- Department of Mechanical and Industrial Engineering, University of Illinois, Chicago, IL, USA
| | - M K Y Chan
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, IL, USA
| | - S K Rs Sankaranarayanan
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, IL, USA
- Department of Mechanical and Industrial Engineering, University of Illinois, Chicago, IL, USA
| | - S Ramanathan
- School of Materials Engineering, Purdue University, West Lafayette, IN, USA
- Department of Electrical and Computer Engineering, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Y Zhu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, USA
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Saha A, Mishra A, Manna S, Ghosh T, Bhattacharya J, Goswami S, Biswas L, Mitra S, Sarkar B, Banik A, Chowdhury S, Biswal S, Mandal S, George K, Soren P, Gazi M. 109P Setting up 4D-CT based image guided radiotherapy (IGRT) for locally advanced lung cancer: Is it safe to reduce PTV margin for dosimetric benefit? J Thorac Oncol 2023. [DOI: 10.1016/s1556-0864(23)00364-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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Das D, Prakash J, Goutam UK, Manna S, Gupta SK, Sudarshan K. Oxygen vacancy and valence engineering in CeO 2 through distinct sized ion doping and their impact on oxygen reduction reaction catalysis. Dalton Trans 2022; 51:18572-18582. [PMID: 36444845 DOI: 10.1039/d2dt03198a] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Defect tuning in ceria to enhance its catalytic properties is a subject of great interest for the scientific community owing to the growing demand for catalytic materials in drug, automobile and chemical industries. Doping induced defect engineering was found to be one of the most sought out strategies particularly in oxides for achieving multifunctionality. Here, in this study, we have doped ceria with distinct sized trivalent rare-earth ions, namely, Y3+, Eu3+ and La3+, using combustion techniques. Positron annihilation lifetime spectroscopy (PALS) suggested enhanced defect density with doping in general and higher concentration of oxygen vacancies in La3+ doped ceria compared to Y3+ and Eu3+ counterparts. X-ray photoelectron spectroscopy (XPS) suggested the existence of both Ce3+ and Ce4+, with the former having higher fraction in CeO2:La3+ compared to CeO2:Y3+. The electron transfer resistance (Rct) reduced in all the doped samples when compared to undoped ceria and they demonstrated improved catalytic activity towards the oxygen reduction reaction (ORR). The highest reduction in Rct was seen in the 5% La doped sample owing to the very high concentration of oxygen vacancies and Ce3+/Ce4+ ratio and CeO2:5.0% La3+ showed the best performance towards ORR electrocatalysis. The studies are expected to help in further tuning the catalysts in terms of dopant concentrations, and in future work, the strategy will be to control the Ce3+/Ce4+ ratio and see its implication in both catalytic and magnetic applications.
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Affiliation(s)
- Debarati Das
- Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai-400085, India. .,Homi Bhabha National Institute, Anushaktinagar, Mumbai-400094, India
| | - Jyoti Prakash
- Homi Bhabha National Institute, Anushaktinagar, Mumbai-400094, India.,Materials Group, Bhabha Atomic Research Centre, Mumbai-400085, India
| | - U K Goutam
- Technical Physics Division, Bhabha Atomic Research Centre, Mumbai-400085, India
| | - S Manna
- Homi Bhabha National Institute, Anushaktinagar, Mumbai-400094, India.,Analytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai-400085, India
| | - Santosh K Gupta
- Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai-400085, India. .,Homi Bhabha National Institute, Anushaktinagar, Mumbai-400094, India
| | - K Sudarshan
- Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai-400085, India. .,Homi Bhabha National Institute, Anushaktinagar, Mumbai-400094, India
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Shailesh M, Suman SK, Malti PK, Pol V, Manna S, Kolekar RV, Satpati SK. Radiological safety during sodium diuranate dissolution process: A radiological data study. Radiat Prot Environ 2022. [DOI: 10.4103/rpe.rpe_12_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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De Leacy R, Bageac DV, Manna S, Gershon BS, Kirke D, Shigematsu T, Sinclair C, Chada D, Som P, Doshi A, Nael K, Berenstein A. A Radiologic Grading System for Assessing the Radiographic Outcome of Treatment in Lymphatic and Lymphatic-Venous Malformations of the Head and Neck. AJNR Am J Neuroradiol 2021; 42:1859-1864. [PMID: 34446456 DOI: 10.3174/ajnr.a7260] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 05/28/2021] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Two-thirds of lymphatic malformations in children are found in the head and neck. Although conventionally managed through surgical resection, percutaneous sclerotherapy has gained popularity. No reproducible grading system has been designed to compare sclerotherapy outcomes on the basis of radiologic findings. We propose an MR imaging-based grading scale to assess the response to sclerotherapy and present an evaluation of its interrater reliability. MATERIALS AND METHODS A grading system was developed to stratify treatment outcomes on the basis of interval changes observed on MR imaging. By means of this system, 56 consecutive cases from our institution with formally diagnosed head and neck lymphatic malformations treated by sclerotherapy were retrospectively graded. Each patient underwent pre- and posttreatment MR imaging. Each study was evaluated by 3 experienced neuroradiologists. Interrater reliability was assessed using the Krippendorff α statistic, intraclass coefficient, and 2-way Spearman ρ correlation. RESULTS The overall Krippendorff α statistic was 0.93 (95% CI, 0.89-0.95), denoting excellent agreement among raters. Intraclass coefficients with respect to consistency and absolute agreements were both 0.97 (95% CI, 0.96-0.98), illustrating low variability. Every combination of individual rater pairs demonstrated statistically significant (P < .01) linear Spearman ρ correlations, with values ranging from 0.90 to 0.95. CONCLUSIONS The proposed radiographic grading scale demonstrates excellent interrater reliability. Adoption of this new scale can standardize reported outcomes following sclerotherapy for head and neck lymphatic malformation and may aid in the investigation of future questions regarding optimal management of these lesions.
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Affiliation(s)
- R De Leacy
- From the Department of Neurosurgery (R.D.L., D.V.B., S.M., B.S.G., T.S., D.C., A.B.), Icahn School of Medicine at Mount Sinai, New York, New York
| | - D V Bageac
- From the Department of Neurosurgery (R.D.L., D.V.B., S.M., B.S.G., T.S., D.C., A.B.), Icahn School of Medicine at Mount Sinai, New York, New York
| | - S Manna
- From the Department of Neurosurgery (R.D.L., D.V.B., S.M., B.S.G., T.S., D.C., A.B.), Icahn School of Medicine at Mount Sinai, New York, New York
- Department of Otolaryngology-Head and Neck Surgery (S.M., D.K., C.S., P.S.), Icahn School of Medicine at Mount Sinai, New York, New York
- Department of Radiology (S.M., P.S., A.D., K.N.), Icahn School of Medicine at Mount Sinai, New York
| | - B S Gershon
- From the Department of Neurosurgery (R.D.L., D.V.B., S.M., B.S.G., T.S., D.C., A.B.), Icahn School of Medicine at Mount Sinai, New York, New York
- College of Medicine (B.S.G.), SUNY Downstate, Brooklyn, New York, New York
| | - D Kirke
- Department of Otolaryngology-Head and Neck Surgery (S.M., D.K., C.S., P.S.), Icahn School of Medicine at Mount Sinai, New York, New York
| | - T Shigematsu
- From the Department of Neurosurgery (R.D.L., D.V.B., S.M., B.S.G., T.S., D.C., A.B.), Icahn School of Medicine at Mount Sinai, New York, New York
| | - C Sinclair
- Department of Otolaryngology-Head and Neck Surgery (S.M., D.K., C.S., P.S.), Icahn School of Medicine at Mount Sinai, New York, New York
| | - D Chada
- From the Department of Neurosurgery (R.D.L., D.V.B., S.M., B.S.G., T.S., D.C., A.B.), Icahn School of Medicine at Mount Sinai, New York, New York
| | - P Som
- Department of Otolaryngology-Head and Neck Surgery (S.M., D.K., C.S., P.S.), Icahn School of Medicine at Mount Sinai, New York, New York
- Department of Radiology (S.M., P.S., A.D., K.N.), Icahn School of Medicine at Mount Sinai, New York
| | - A Doshi
- Department of Radiology (S.M., P.S., A.D., K.N.), Icahn School of Medicine at Mount Sinai, New York
| | - K Nael
- Department of Radiology (S.M., P.S., A.D., K.N.), Icahn School of Medicine at Mount Sinai, New York
| | - A Berenstein
- From the Department of Neurosurgery (R.D.L., D.V.B., S.M., B.S.G., T.S., D.C., A.B.), Icahn School of Medicine at Mount Sinai, New York, New York
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Manna S, Chaudhuri RK, Chattopadhyay S. Taming the excited states of butadiene, hexatriene, and octatetraene using state specific multireference perturbation theory with density functional theory orbitals. J Chem Phys 2020; 152:244105. [DOI: 10.1063/5.0007198] [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: 11/14/2022] Open
Affiliation(s)
- Shovan Manna
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103, India
| | | | - Sudip Chattopadhyay
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103, India
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Manna S, Sinha Ray S, Ghosh P, Chattopadhyay S. Structural properties and isomerisation of simple S-nitrosothiols: ab initio studies with a simplified treatment of correlation effects. Mol Phys 2020. [DOI: 10.1080/00268976.2019.1641639] [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: 10/26/2022]
Affiliation(s)
- Shovan Manna
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Howrah, India
| | | | - Pradipta Ghosh
- Department of Chemistry, Jhargram Raj College, Jhargram, India
| | - Sudip Chattopadhyay
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Howrah, India
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Pop L, Manna S, Christley S, Freifeld Y, Vo D, Filatenkov A, Kapur P, Monson N, Pedrosa I, Brugarolas J, Timmerman R, Margulis V, Cowell L, Hannan R. Immune Correlates of Abscopal Response in a Lead-in Phase II Trial of Neoadjuvant Stereotactic Ablative Radiotherapy (SABR) for Renal Cell Carcinoma Inferior Vena Cava Tumor Thrombus. Int J Radiat Oncol Biol Phys 2019. [DOI: 10.1016/j.ijrobp.2019.06.430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Manna S, Mulgaonkar A, Woolford L, Nham K, Hao G, Pop L, Bowman I, Brugarolas J, Sun X, Hannan R. Immuno-PET Evaluation of In Vivo Therapeutic Resistance in Renal Cell Carcinoma Patient-Derived Xenografts. Int J Radiat Oncol Biol Phys 2019. [DOI: 10.1016/j.ijrobp.2019.06.1064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Manna S, Ray SS, Chattopadhyay S, Chaudhuri RK. A simplified account of the correlation effects to bond breaking processes: The Brillouin-Wigner perturbation theory using a multireference formulation. J Chem Phys 2019. [DOI: 10.1063/1.5097657] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Shovan Manna
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103, India
| | - Suvonil Sinha Ray
- Department of Chemistry, University of Calcutta, Kolkata 700009, India
| | - Sudip Chattopadhyay
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103, India
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Manna S, Ray SS, Ghosh P, Chattopadhyay S. On the conversion XCN ⟷ XNC via an efficient and economic perturbative wave function approach. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1464224] [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: 10/17/2022]
Affiliation(s)
- Shovan Manna
- Department of Chemistry, Indian Institute of Engineering Science and Technology , Shibpur, India
| | - Suvonil Sinha Ray
- Department of Chemistry, Indian Institute of Engineering Science and Technology , Shibpur, India
| | - Pradipta Ghosh
- Department of Chemistry, Jhargram Raj College , Jhargram, India
| | - Sudip Chattopadhyay
- Department of Chemistry, Indian Institute of Engineering Science and Technology , Shibpur, India
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Manna S, Ortika BD, Dunne EM, Holt KE, Kama M, Russell FM, Hinds J, Satzke C. A novel genetic variant of Streptococcus pneumoniae serotype 11A discovered in Fiji. Clin Microbiol Infect 2017; 24:428.e1-428.e7. [PMID: 28736074 PMCID: PMC5869949 DOI: 10.1016/j.cmi.2017.06.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 06/13/2017] [Accepted: 06/30/2017] [Indexed: 11/26/2022]
Abstract
Objectives As part of annual cross-sectional Streptococcus pneumoniae carriage surveys in Fiji (2012–2015), we detected pneumococci in over 100 nasopharyngeal swabs that serotyped as ‘11F-like’ by microarray. We examined the genetic basis of this divergence in the 11F-like capsular polysaccharide (cps) locus compared to the reference 11F cps sequence. The impact of this diversity on capsule phenotype, and serotype results using genetic and serologic methods were determined. Methods Genomic DNA from representative 11F-like S. pneumoniae isolates obtained from the nasopharynx of Fijian children was extracted and subject to whole genome sequencing. Genetic and phylogenetic analyses were used to identify genetic changes in the cps locus. Capsular phenotypes were evaluated using the Quellung reaction and latex agglutination. Results Compared to published 11F sequences, the wcwC and wcrL genes of the 11F-like cps locus are phylogenetically divergent, and the gct gene contains a single nucleotide insertion within a homopolymeric region. These changes within the DNA sequence of the 11F-like cps locus have modified the antigenic properties of the capsule, such that 11F-like isolates serotype as 11A by Quellung reaction and latex agglutination. Conclusions This study demonstrates the ability of molecular serotyping by microarray to identify genetic variants of S. pneumoniae and highlights the potential for discrepant results between phenotypic and genotypic serotyping methods. We propose that 11F-like isolates are not a new serotype but rather are a novel genetic variant of serotype 11A. These findings have implications for invasive pneumococcal disease surveillance as well as studies investigating vaccine impact.
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Affiliation(s)
- S Manna
- Pneumococcal Research, Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia.
| | - B D Ortika
- Pneumococcal Research, Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| | - E M Dunne
- Pneumococcal Research, Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| | - K E Holt
- Centre for Systems Genomics, The University of Melbourne, Parkville, Victoria, Australia; Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - M Kama
- Ministry of Health and Medical Services, Suva, Fiji
| | - F M Russell
- Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia; Centre for International Child Health, Murdoch Childrens Research Institute, Melbourne, Australia
| | - J Hinds
- Institute for Infection and Immunity, St. George's, University of London, United Kingdom; BUGS Bioscience, London Bioscience Innovation Centre, London, United Kingdom
| | - C Satzke
- Pneumococcal Research, Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia; Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia; Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Parkville, Victoria, Australia
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Sinha Ray S, Manna S, Chaudhuri RK, Chattopadhyay S. Description of C2 dissociation using a naive treatment of dynamical correlation in the presence of quasidegeneracy of varying degree. Mol Phys 2017. [DOI: 10.1080/00268976.2017.1323129] [Citation(s) in RCA: 7] [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: 10/19/2022]
Affiliation(s)
- Suvonil Sinha Ray
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Howrah, India
| | - Shovan Manna
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Howrah, India
| | | | - Sudip Chattopadhyay
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Howrah, India
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17
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Manna S, Kamlapure A, Cornils L, Hänke T, Hedegaard EMJ, Bremholm M, Iversen BB, Hofmann P, Wiebe J, Wiesendanger R. Interfacial superconductivity in a bi-collinear antiferromagnetically ordered FeTe monolayer on a topological insulator. Nat Commun 2017; 8:14074. [PMID: 28094258 PMCID: PMC5247605 DOI: 10.1038/ncomms14074] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 11/25/2016] [Indexed: 11/09/2022] Open
Abstract
The discovery of high-temperature superconductivity in Fe-based compounds triggered numerous investigations on the interplay between superconductivity and magnetism, and on the enhancement of transition temperatures through interface effects. It is widely believed that the emergence of optimal superconductivity is intimately linked to the suppression of long-range antiferromagnetic (AFM) order, although the exact microscopic picture remains elusive because of the lack of atomically resolved data. Here we present spin-polarized scanning tunnelling spectroscopy of ultrathin FeTe1-xSex (x=0, 0.5) films on bulk topological insulators. Surprisingly, we find an energy gap at the Fermi level, indicating superconducting correlations up to Tc∼6 K for one unit cell FeTe grown on Bi2Te3, in contrast to the non-superconducting bulk FeTe. The gap spatially coexists with bi-collinear AFM order. This finding opens perspectives for theoretical studies of competing orders in Fe-based superconductors and for experimental investigations of exotic phases in superconducting layers on topological insulators.
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Affiliation(s)
- S Manna
- Department of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany
| | - A Kamlapure
- Department of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany
| | - L Cornils
- Department of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany
| | - T Hänke
- Department of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany
| | - E M J Hedegaard
- Department of Chemistry and iNANO, Center for Materials Crystallography, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark
| | - M Bremholm
- Department of Chemistry and iNANO, Center for Materials Crystallography, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark
| | - B B Iversen
- Department of Chemistry and iNANO, Center for Materials Crystallography, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark
| | - Ph Hofmann
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, DK-8000 Aarhus C, Denmark
| | - J Wiebe
- Department of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany
| | - R Wiesendanger
- Department of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany
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Srivastava V, Bhattacharya C, Rana T, Manna S, Kundu S, Bhattacharya S, Banerjee K, Roy P, Pandey R, Mukherjee G, Ghosh T, Meena J, Roy T, Chaudhuri A, Sinha M, Saha A, Asgar MA, Dey A, Roy S, Moin Shaikh M. Excited states of 26Al studied via the reaction 27Al(d,t). EPJ Web of Conferences 2016. [DOI: 10.1051/epjconf/201611707022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Kapoor R, Roy VK, Manna S, Bhattacharjee M. Level of Mercury Manometer With Respect to Heart: Does it Affect Blood Pressure Measurement? Indian J Physiol Pharmacol 2015; 59:238-241. [PMID: 26685514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Measurement of blood pressure is an integral part of clinical examination. Over the years various types of instruments have been used to measure blood pressure but till date the mercury sphygmomanometer is regarded as the gold standard. However, there is a myth prevalent among health professionals regarding the level of the manometer in relation to heart at the time of measuring of blood pressure. Many professionals insist that it has to be placed at the level of the heart. We argue that the limb from which pressure is measured must be at the heart level rather than the manometer. We conducted a study in which we measured the blood pressure in adults by placing the manometer at three different levels with respect to the heart. The values of blood pressure obtained at all levels were similar and did not show any statistically significant difference. We therefore conclude that the level of sphygmomanometer per se does not affect blood pressure measurement.
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Manna S, Aluguri R, Bar R, Das S, Prtljaga N, Pavesi L, Ray SK. Enhancement of photoluminescence intensity of erbium doped silica containing Ge nanocrystals: distance dependent interactions. Nanotechnology 2015; 26:045202. [PMID: 25558802 DOI: 10.1088/0957-4484/26/4/045202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Photo-physical processes in Er-doped silica glass matrix containing Ge nanocrystals prepared by the sol-gel method are presented in this article. Strong photoluminescence at 1.54 μm, important for fiber optics telecommunication systems, is observed from the different sol-gel derived glasses at room temperature. We demonstrate that Ge nanocrystals act as strong sensitizers for Er(3+) ions emission and the effective Er excitation cross section increases by almost four orders of magnitude with respect to the one without Ge nanocrystals. Rate equations are considered to demonstrate the sensitization of erbium luminescence by Ge nanocrystals. Analyzing the erbium effective excitation cross section, extracted from the flux dependent rise and decay times, a Dexter type of short range energy transfer from a Ge nanocrystal to erbium ion is established.
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Affiliation(s)
- S Manna
- Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur-721 302, India
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21
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Srivastava V, Bhattacharya C, Rana TK, Manna S, Kundu S, Bhattacharya S, Banerjee K, Roy P, Pandey R, Mukherjee G, Ghosh TK, Meena JK, Roy T, Chaudhuri A, Sinha M, Saha A, Dey A, Asgar MA, Roy S, Shaikh MM. Structure of26Al studied by one - nucleon transfer reaction27Al(d,t). EPJ Web of Conferences 2015. [DOI: 10.1051/epjconf/20158600055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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22
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Rana TK, Bhattacharya C, Manna S, Srivastava V, Banerjee K, Kundu S, Roy P, Pandey R, Chaudhuri A, Roy T, Ghosh TK, Mukherjee G, Bhattacharya S, Meena JK, Pandit SK, Mahata K, Patale P, Shrivastava A, Nanal V. Fragment emission studies in low energy light heavy-ion reactions. EPJ Web of Conferences 2015. [DOI: 10.1051/epjconf/20158600036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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23
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Arenas-Lopez S, Mulla H, Manna S, Durward A, Murdoch I, Tibby S. Enteral absorption and haemodynamic response of clonidine in infants post-cardiac surgery. Br J Anaesth 2014; 113:964-9. [DOI: 10.1093/bja/aeu258] [Citation(s) in RCA: 11] [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: 11/13/2022] Open
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Farina G, Menditto E, Manna S, Pagliaro C, Troncone C, Putignano D, Orlando V, Linguiti C, Buffardi GF, Tari MG. Analysis of Prescribing Patterns of Atypical Antipsychotics in Lhu Caserta. Value Health 2014; 17:A464-A465. [PMID: 27201311 DOI: 10.1016/j.jval.2014.08.1297] [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] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
| | - E Menditto
- CIRFF- Center of Pharmacoeconomics, Naples, Italy
| | | | | | | | - D Putignano
- CIRFF- Center of Pharmacoeconomics, Naples, Italy
| | - V Orlando
- CIRFF- Center of Pharmacoeconomics, Naples, Italy
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Das K, Mukherjee S, Manna S, Ray SK, Raychaudhuri AK. Single Si nanowire (diameter ≤ 100 nm) based polarization sensitive near-infrared photodetector with ultra-high responsivity. Nanoscale 2014; 6:11232-9. [PMID: 25126742 DOI: 10.1039/c4nr03170a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We report the fabrication and optical response of boron-doped single silicon nanowire-based metal-semiconductor-metal photodetector. Typical single nanowire devices with diameter of ∼80-100 nm and electrode spacing of ∼1 μm were made using electron-beam lithography from nanowires, grown by a metal-assisted chemical etching process. A high responsivity, of the order of 10(4) A W(-1), was observed even at zero bias in a single nanowire photodetector with peak responsivity in the near-infrared region. The responsivity was found to increase with increasing bias and decreasing nanowire diameter. Finite element based optical simulation was proposed to explain the diameter dependent performance of a single nanowire. The observed photoresponse is sensitive to the polarization of exciting light source, allowing the device to act as a polarization-dependent near-infrared photodetector.
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Affiliation(s)
- K Das
- Theme Unit of Excellence in Nanodevice Technology, S.N. Bose National Center for Basic Sciences, Sector-III, Salt Lake, Kolkata-700098, India.
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Manna S, Aluguri R, Katiyar A, Das S, Laha A, Osten HJ, Ray SK. MBE-grown Si and Si(1-x)Ge(x) quantum dots embedded within epitaxial Gd2O3 on Si(111) substrate for floating gate memory device. Nanotechnology 2013; 24:505709. [PMID: 24284782 DOI: 10.1088/0957-4484/24/50/505709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Si and Si(1-x)Ge(x) quantum dots embedded within epitaxial Gd2O3 grown by molecular beam epitaxy have been studied for application in floating gate memory devices. The effect of interface traps and the role of quantum dots on the memory properties have been studied using frequency-dependent capacitance-voltage and conductance-voltage measurements. Multilayer quantum dot memory comprising four and five layers of Si quantum dots exhibits a superior memory window to that of single-layer quantum dot memory devices. It has also been observed that single-layer Si(1-x)Ge(x) quantum dots show better memory characteristics than single-layer Si quantum dots.
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Affiliation(s)
- S Manna
- Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur-721302, India
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Manna S, Prtljaga N, Das S, Daldosso N, Ray SK, Pavesi L. Photophysics of resonantly and non-resonantly excited erbium doped Ge nanowires. Nanotechnology 2012; 23:065702. [PMID: 22248558 DOI: 10.1088/0957-4484/23/6/065702] [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] [Indexed: 05/31/2023]
Abstract
We have fabricated Er doped germanium nanowires of different diameters by pulsed laser deposition and chemical methods. Er induced photoluminescence emission due to the intra-4f (4)I(13/2)→(4)I(15/2) transition of Er energy levels at 1.53 µm has been achieved at room temperature using both resonant (980 nm) and non-resonant (325 nm) excitation of Er ions. The observed 1.53 µm photoluminescence signal upon non-resonant 325 nm excitation is attributed to the Ge related oxygen deficiency centers surrounding the Ge core. For direct excitation, the infrared photoluminescence characteristics have been studied as a function of Er concentration, photon flux, and diameter of the nanowires. The Er related emission signal is found to be enhanced with increase in Er concentration, pump flux of 980 nm, and the nanowire diameter. The time resolved characteristics of the Er induced emission peak have been studied as a function of the pump flux as well as the diameter of the Ge nanowires.
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Affiliation(s)
- S Manna
- Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur, India
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Chowdhury SR, Manna S, Saha P, Basak RK, Sen R, Roy D, Adhikari B. Composition analysis and material characterization of an emulsifying extracellular polysaccharide (EPS) produced by Bacillus megaterium RB-05: a hydrodynamic sediment-attached isolate of freshwater origin. J Appl Microbiol 2011; 111:1381-93. [PMID: 21973188 DOI: 10.1111/j.1365-2672.2011.05162.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
AIMS This work was aimed to isolate, purify and characterize an extracellular polysaccharide (EPS) produced by a freshwater dynamic sediment-attached micro-organism, Bacillus megaterium RB-05, and study its emulsifying potential in different hydrocarbon media. METHODS AND RESULTS Bacillus megaterium RB-05 was found to produce EPSs in glucose mineral salts medium, and maximum yield (0.864 g l(-1) ) was achieved after 24-h incubation. The recovery rates of the polysaccharide material by ion-exchange and gel filtration chromatography were around 67 and 93%, respectively. As evident from HPLC and FT-IR analyses, the polysaccharide was found to be a heteropolymer-containing glucose, galactose, mannose, arabinose, fucose and N-acetyl glucosamine. Different oligosaccharide combinations namely hexose(3), hexose(4), hexose(5) deoxyhexose(1) and hexose(5) deoxyhexose(1) pentose(3) were obtained after partial hydrolysis of the polymer using MALDI-ToF-MS. The polysaccharide with an average molecular weight of 170 kDa and thermal stability up to 180°C showed pseudoplastic rheology and significant emulsifying activity in hydrocarbon media. CONCLUSIONS Isolated polysaccharide was found to be of high molecular weight and thermally stable. The purified EPS fraction was composed of hexose, pentose and deoxyhexose sugar residues, which is a rare combination for bacterial polysaccharides. Emulsifying property was either better or comparable to that of other commercially available natural gums and polysaccharides. SIGNIFICANCE AND IMPACT OF THE STUDY This is probably one of the few reports about characterizing an emulsifying EPS produced by a freshwater sediment-attached bacterium. The results of this study contribute to understand the influence of chemical composition and material properties of a new microbial polysaccharide on its application in industrial biotechnology. Furthermore, this work reconfirms freshwater dynamic sediment as a potential habitat for bioprospecting extracellular polymer-producing bacteria. This study will improve our knowledge on the exploitation of a nonconventional renewable resource, which also seems to be ecologically significant.
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Affiliation(s)
- S R Chowdhury
- Materials Science Centre, Indian Institute of Technology Kharagpur, Kharagpur, WB, India
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Abstract
AbstractSeveral species of aquatic bacteria are known to exploit the earth's geomagnetic field as a means of directing their motion towards suitable habitats. A feature common to these bacteria is the presence of discrete intracellular magnetic inclusions, magnetosomes, aligned in chains along the long axis of the organism. The size and orientation of the individual magnetic particles imparts a permanent magnetic dipole moment to the cell which is, in turn, responsible for the magnetotactic response. In all species examined to date the magnetic particles have been found to be well-ordered, single domain, membrane-bounded crystals with reproducible, species-specific morphologies. Until recently, however, only crystals of the mixed valence iron oxide, magnetite (Fe3O4), were identified in these magnetotactic bacteria. We have now identified three species of bacteria from sulphidic environments which contain crystals of the mixed valence ferrimagnetic iron sulphide, greigite (Fe3S4). High resolution electron microscopical studies of the biogenic greigite crystals showed that they also exhibit the narrow size range (50–90nm) and unique crystallographic habits (e.g. cubo-octahedral, rectangular prismatic) which characterized and distinguished the inclusions in other magnetotactic species. Thus, it would appear that the bio-precipitation of iron sulphides in magnetotactic bacteria is a highly regulated process which is directed and controlled at the molecular level. These findings are not only important to our understanding of biomineralization in unicellular organisms but may also be significant to studies of paleomagnetism. Furthermore, the controlled synthesis of greigite presents an interesting challenge to material scientists and solid state chemists.
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Jana A, Saha R, Ghosh A, Manna S, Ribas J, Ray Chaudhuri N, Mostafa G. Role of weak interactions in controlling the topology of coordination polymeric chains in [Pt(CN)4]2− bridged Cu(II) complexes: Syntheses, crystal structure and magnetic studies. Polyhedron 2009. [DOI: 10.1016/j.poly.2009.06.076] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
Three medicinal plants Ocimum sanctum, Ocimum bacilicum and Leucas aspera were screened to study endophytic diversity of the plants. Altogether 103 fungal endophytes belonging to fourteen genera were isolated. Leaves of all three medicinal plants were colonized by a great number of endophytic fungi. Leaves of O. sanctum were colonized by the most, that is, eleven endophytes. Highest Shannon-Wiener index (2.256) was exhibited by O. sanctum with the highest Simpson's diversity (0.8654) indicating great species specificity. O. bacilicum and L. aspera showed the highest similarity coefficient. Some fungal genera have been showed to be host specific. In the present study Curvularia sp., Hymenula sp., Tricoderma sp. and Tubercularia sp. exclusively colonized O. sanctum ; whereas Alternaria sp. and Spicaria sp. colonized only L. aspera .
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Affiliation(s)
- D Banerjee
- Department of Microbiology, Vidyasagar University, West Bengal, India.
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Manna S, Majumder S, De SK. Tuning of the spin gap transition of spin dimer compound Ba(3)Mn(2)O(8) by doping with La and V. J Phys Condens Matter 2009; 21:236005. [PMID: 21825602 DOI: 10.1088/0953-8984/21/23/236005] [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] [Indexed: 05/31/2023]
Abstract
We have successfully synthesized the coupled spin dimer systems La(x)Ba(3-x)Mn(2)O(8) (x = 0, 0.2, 0.5, 1) and Ba(3)Mn(2-y)V(y)O(8) (y = 0.5, 1.0, 2.0). The magnetic properties have been investigated as a function of magnetic field and temperature down to 2 K. The susceptibility increases and the intradimer spin exchange interaction decreases with increase of La concentration. The most important finding in higher La doped systems reveals hysteresis in magnetization as a function of magnetic field. The substitution of La (x = 0.5, 1.0) for Ba induces ferromagnetism due to the formation of a mixed valence state of Mn and enhancement of the inter-bilayer ferromagnetic interaction. The replacement of Mn by non-magnetic V destroys the spin gap. La and V doping significantly affect the magnetic properties of the quantum antiferromagnetic compound Ba(3)Mn(2)O(8).
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Affiliation(s)
- S Manna
- Department of Materials Science, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India. Centre for Advanced Materials, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
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Dasgupta D, Manna S, Garai A, Dawn A, Rochas C, Guenet JM, Nandi AK. Morphology, Structure, Rheology, and Thermodynamics of Piezoelectric Poly(vinylidene fluoride)−Ethylene Carbonate Thermoreversible Gel. Macromolecules 2008. [DOI: 10.1021/ma7021502] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Riphagen S, Alasnag M, Hanna S, Manna S, McDougall M. Inter-rater agreement in the triage of calls to a paediatric interhospital transfer service. Crit Care 2007. [PMCID: PMC4095493 DOI: 10.1186/cc5600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Abstract
This study examined the effect of deltamethrin on some of the neuropharmacological paradigms in a rat brain such as the motor co-ordination test using a rotarod, the pentobarbitone-induced sleeping time and pentylenetetrazole (PTZ)-induced convulsion as well as the gamma aminobutyric acid (GABA) level. Albino Wistar rats were used as the experimental animals. Different neuropharmacological paradigms such as the motor co-ordination by the rotarod, pentobarbitone-induced sleeping time and the PTZ-induced convulsion were examined after administering deltamethrin orally at two doses, 150 mg/kg (LD50) and 15 mg/kg (1/10 LD50). The GABA level in the rat brain was estimated by HPLC after a single oral dose of 150mg/kg deltamethrin. Deltamethrin significantly reduced the motor coordination, decreased the onset time and increased the sleeping time duration induced by pentobarbitone. In addition, it also decreased the onset time and increased the duration of convulsions induced by PTZ at 150 mg/kg (LD50) and 15 mg/kg (1/10 LD50), respectively. Further deltamethrin administration decreased the GABA levels in the cerebellum as well as in the whole brain (except the cerebellum) significantly at the LD50 dose level. There was some correlation between the effect of deltamethrin on the central GABA levels and its neuropharmacological effects.
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Affiliation(s)
- S Manna
- Institute of Animal Health and Veterinary Biologicals (R&T), 37-Belgachia Rd, Kolkata-700 037, India.
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Banerjee S, Manna S, Saha P, Panda CK, Das S. Black tea polyphenols suppress cell proliferation and induce apoptosis during benzo(a)pyrene-induced lung carcinogenesis. Eur J Cancer Prev 2005; 14:215-21. [PMID: 15901989 DOI: 10.1097/00008469-200506000-00004] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
One of the most promising strategies for cancer prevention is chemoprevention by daily used food and beverages. Black tea, the most widely consumed beverage, is a source of compounds with antioxidative, antimicrobial, antimutagenic and anticarcinogenic properties. Lung cancer is the most common cause of cancer deaths in both men and women worldwide. Over one million people around the world are likely to be killed by lung cancer due to increased tobacco smoking and environmental pollutants, especially car exhausts. Therefore chemopreventive intervention using black tea and its active components may be a viable means to reduce lung cancer death. In the present investigation, we used benzo(a)pyrene (BP) to induce lung carcinogenesis in mice for the assessment of potential apoptosis-inducing and proliferation-suppressing effects of theaflavins and epigallocatechin gallate, active components of black tea. Hyperplasia, dysplasia and carcinoma in situ evident in the carcinogen control group on the 8th, 17th and 26th weeks respectively, were effectively reduced after treatment with theaflavins and epigallocatechin gallate. Significant reduction in number of proliferating cells and increased number of apoptotic cells was also found on the 8th, 17th and 26th week of treatment with theaflavins and epigallocatechin gallate in BP-exposed mice. Our observation suggests a promising role for black tea polyphenols in the prevention of lung cancer.
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Affiliation(s)
- S Banerjee
- Department of Cancer Chemoprevention, Chittarajan National Cancer Institute, 37, S.P. Mukherjee Road, Kolkata 700026, West Bengal, India
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Dasgupta D, Manna S, Malik S, Rochas C, Guenet JM, Nandi AK. Thermodynamic Structural and Morphological Investigation of Poly(Vinylidene Fluoride)−Camphor Systems, Preparing Porous Gels from a Solid Solvent. Macromolecules 2005. [DOI: 10.1021/ma050582a] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- D. Dasgupta
- Polymer Science Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India, Institut Charles Sadron, CNRS UPR 22, BP 40016, 6 Rue Boussingault, 67083 Strasbourg Cedex, France, and Laboratoire de Spectrometrie Physique CNRS-UJF UMR5588, 38402 Saint Martin d'Heres Cedex, France
| | - S. Manna
- Polymer Science Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India, Institut Charles Sadron, CNRS UPR 22, BP 40016, 6 Rue Boussingault, 67083 Strasbourg Cedex, France, and Laboratoire de Spectrometrie Physique CNRS-UJF UMR5588, 38402 Saint Martin d'Heres Cedex, France
| | - S. Malik
- Polymer Science Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India, Institut Charles Sadron, CNRS UPR 22, BP 40016, 6 Rue Boussingault, 67083 Strasbourg Cedex, France, and Laboratoire de Spectrometrie Physique CNRS-UJF UMR5588, 38402 Saint Martin d'Heres Cedex, France
| | - C. Rochas
- Polymer Science Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India, Institut Charles Sadron, CNRS UPR 22, BP 40016, 6 Rue Boussingault, 67083 Strasbourg Cedex, France, and Laboratoire de Spectrometrie Physique CNRS-UJF UMR5588, 38402 Saint Martin d'Heres Cedex, France
| | - J. M. Guenet
- Polymer Science Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India, Institut Charles Sadron, CNRS UPR 22, BP 40016, 6 Rue Boussingault, 67083 Strasbourg Cedex, France, and Laboratoire de Spectrometrie Physique CNRS-UJF UMR5588, 38402 Saint Martin d'Heres Cedex, France
| | - A. K. Nandi
- Polymer Science Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India, Institut Charles Sadron, CNRS UPR 22, BP 40016, 6 Rue Boussingault, 67083 Strasbourg Cedex, France, and Laboratoire de Spectrometrie Physique CNRS-UJF UMR5588, 38402 Saint Martin d'Heres Cedex, France
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Felix K, Wise K, Manna S, Yamauchi K, Wilson BL, Thomas RL, Kulkarni A, Pellis NR, Ramesh GT. Altered cytokine expression in tissues of mice subjected to simulated microgravity. Mol Cell Biochem 2005; 266:79-85. [PMID: 15646029 DOI: 10.1023/b:mcbi.0000049136.55611.dd] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [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: 11/12/2022]
Abstract
Space flight is known to induce microgravity-associated immune dysfunction in humans, non-human primates and rodents. To understand the mechanism underlying these defects, several studies in rodents have been conducted in a ground-based antiorthostatic suspension (AOS) model that would mimic the effects of microgravity. In all these in vivo studies that showed the effects on cytokine profiles actually investigated the ex vivo production from culturing the cells isolated from whole organism that was exposed to space flight and/or microgravity. So, the purpose of the study was to examine the in vivo expression of cytokines in mice in immunologically important tissue environments of mice that were subjected to AOS. Cytokines such as Interleukin-1beta, (IL-1beta), IL-2, IL-3, IL-6, Interferon-gamma (IFN-gamma) and Tumor Necrosis Factor-alpha (TNF-alpha) were measured by Enzyme Linked Immunosorbent Assay (ELISA) in the homogenates of spleen tissue, lymph nodes and also in serum of AOS mice and compared with that of control mice. AOS induced no change in the IL-3 levels, but IL-1beta was increased significantly whereas IL-2 levels decreased in spleen, lymph nodes and serum. IL-6 levels did not differ in spleen but were significantly increased in lymph nodes and serum of AOS mice. IFN-gamma levels in spleen did not change but showed nonsignificant reduction in lymph nodes and significant reduction in serum in response to AOS. TNF-alpha levels in spleen and serum were unchanged and increased in lymph nodes. This in vivo cytokine study confirms the earlier findings that microgravity-simulated conditions induce tissue-specific immune response.
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Affiliation(s)
- K Felix
- Molecular Neurotoxicology Laboratory, Department of Biology, Texas Southern University, Houston, TX 77004, USA
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Manna S, Bhattacharyya D, Mandal TK, Das S. Repeated dose toxicity of alfa-cypermethrin in rats. J Vet Sci 2004; 5:241-5. [PMID: 15365239] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023] Open
Abstract
The present study was performed to investigate the subacute effect of alpha-cypermethrin (alpha-CP) in rats. Alfacypermethrin a synthetic pyrethroid insecticide, dissolved in dimethyl sulfoxide (DMSO) and oral LD50 was investigated after administering orally different doses in rats and was determined as 145 mg/kg. Other groups of rats were given repeated daily oral dose (1/10 LD50) of alpha-CP for 30 days. The animals were sacrificed on 31st day. Activities of various enzymes, cytochrome P450 and b5 contents in liver, hepatic antioxidant status, tissue residue concentration, haemogram and pathological changes were studied. It increased the serum aminotransaminases (AST, ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) activities and blood glucose level significantly. alpha-CP decreased RBC count, PCV and Hb level significantly. It significantly decreased cytochrome P450 in liver. Residues were present in different tissues. It increased malondialdehyde (MDA) level, while decreased the activities of catalase (CAT), superoxide dismutase (SOD) and glycogen level in liver significantly. Mild to moderate histological alterations were observed in lungs, liver, stomach, kidneys, testes and cerebellum. So repeated daily oral doses of alpha-CP at 1/10LD50 altered the biochemical parameters, decreased cytochrome P450 content, antioxidant status, which correlated with histopathological changes of tissues.
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Affiliation(s)
- S Manna
- I A H & V B (R&T), Room No. 122, 68-K. B. Sarani, Kolkata 700037, India.
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Affiliation(s)
- S Manna
- Research Assistant, I A H & V B (R&T), Room No. 122, 68-K. B. Sarani, Kolkata 700037, India
| | - D Bhattacharyya
- Research Assistant, I A H & V B (R&T), Room No. 122, 68-K. B. Sarani, Kolkata 700037, India
| | - T K Mandal
- Research Assistant, I A H & V B (R&T), Room No. 122, 68-K. B. Sarani, Kolkata 700037, India
| | - S Das
- Research Assistant, I A H & V B (R&T), Room No. 122, 68-K. B. Sarani, Kolkata 700037, India
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Falck JR, Manna S, Jacobson HR, Estabrook RW, Chacos N, Capdevila J. Absolute configuration of epoxyeicosatrienoic acids (EETs) formed during catalytic oxygenation of arachidonic acid by purified rat liver microsomal cytochrome P-450. J Am Chem Soc 2002. [DOI: 10.1021/ja00323a046] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Qin H, Valentino J, Manna S, Tripathi PK, Bhattacharya-Chatterjee M, Foon KA, O'Malley BW, Chatterjee SK. Gene therapy for head and neck cancer using vaccinia virus expressing IL-2 in a murine model, with evidence of immune suppression. Mol Ther 2001; 4:551-8. [PMID: 11735339 DOI: 10.1006/mthe.2001.0493] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [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] [Indexed: 11/22/2022] Open
Abstract
We evaluated the efficiency of recombinant vaccinia virus expressing interleukin-2 (rvv-IL-2) as a tumor vaccine in an immunocompetent mouse model of head and neck squamous cell carcinoma (SCC VII/SF). Mice with five-day-old tumors in the floor of the mouth were treated with rvv-IL-2 by intratumoral injections. These treated mice survived longer (P <.03) than mice treated with control vaccines. Splenocytes, bone marrow, and lymph node cells from tumor-bearing mice responded poorly to concanavalin A stimulation, suggesting induction of immunosuppression. The rvv-IL-2 virus grew for 7 days in the tumor following intratumoral injection. We did not detect any virus particles in several normal organs following rvv-IL-2 injection. Comparison of expression levels of several potential immune inhibitory mediators between the tumors growing in mice and cultured tumor cells demonstrated higher expression of IL-10, GM-CSF, TGF-beta, and NO synthetase in tumors. These results suggested possible roles for these molecules in immunosuppression. We conclude that rvv-IL-2 has potential as a therapeutic vaccine for head and neck cancer and that it can be more effective provided the immunosuppression is reversed.
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Affiliation(s)
- H Qin
- Department of Internal Medicine and the Barrett Cancer Center, University of Cincinnati, Cincinnati, Ohio 45267, USA
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Jarrahian A, Manna S, Edgemond WS, Campbell WB, Hillard CJ. Structure-activity relationships among N-arachidonylethanolamine (Anandamide) head group analogues for the anandamide transporter. J Neurochem 2000; 74:2597-606. [PMID: 10820223 DOI: 10.1046/j.1471-4159.2000.0742597.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.0] [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] [Indexed: 11/20/2022]
Abstract
Two putative endocannabinoids, N-arachidonylethanolamine (AEA) and 2-arachidonylglycerol, are inactivated by removal from the extracellular environment by a process that has the features of protein-mediated facilitated diffusion. We have synthesized and studied 22 N-linked analogues of arachidonylamide for the purpose of increasing our understanding of the structural requirements for the binding of ligands to the AEA transporter. We have also determined the affinities of these analogues for both the CB(1) cannabinoid receptor and fatty acid amide hydrolase (FAAH). We have identified several structural features that enhance binding to the AEA transporter in cerebellar granule cells. We have confirmed the findings of others that replacing the ethanolamine head group with 4-hydroxybenzyl results in a high-affinity ligand for the transporter. However, we find that the same molecule is also a competitive inhibitor of FAAH. Similarly, replacement of the ethanolamine of AEA with 3-pyridinyl also results in a high-affinity inhibitor of both the transporter and FAAH. We conclude that the structural requirements for ligand binding to the CB(1) receptor and binding to the transporter are very different; however, the transporter and FAAH share most, but not all, structural requirements.
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Affiliation(s)
- A Jarrahian
- Department of Pharmacology, Medical College of Wisconsin, Milwaukee 53226, USA
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Chatterjee SK, Qin H, Manna S, Tripathi PK. Recombinant vaccinia virus expressing cytokine GM-CSF as tumor vaccine. Anticancer Res 1999; 19:2869-73. [PMID: 10652566] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
The efficacy of a recombinant vaccinia virus (rvv-GM-CSF) expressing the granulocyte macrophage colony stimulating factor (GM-CSF) as tumor vaccine was evaluated in the murine B16-F10 melanoma model. The vaccine was prepared by infection of irradiated tumor cells with rvv-GM-CSF. Control vaccine was B-16 cells infected with a recombinant vaccinia virus expressing Escherichia coli beta-galactosidase (rvv-lacZ). Pre-vaccination of naive C57BL/6 mice later inoculated with tumor cells and treatment of mice bearing tumors with GM-CSF vaccine inhibited tumor development and prolonged survival. Lung metastasis of B-16 was also inhibited by treatment with GM-CSF vaccine. The vaccine effects appeared to be tumor cell specific. The efficacy of the vaccine was comparable to a retroviral vaccine (MFG-muGM-CSF) in this system. The vaccine was also effective when rvv-GM-CSF was directly injected into the tumor. These data suggest that this vaccine approach has potential for use in cancer treatment, especially for patients with easily accessible tumors.
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Affiliation(s)
- S K Chatterjee
- Department of Internal Medicine, Lucille Parker Markey Cancer Center, University of Kentucky Medical Center, Lexington 40536, USA
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Hillard CJ, Manna S, Greenberg MJ, DiCamelli R, Ross RA, Stevenson LA, Murphy V, Pertwee RG, Campbell WB. Synthesis and characterization of potent and selective agonists of the neuronal cannabinoid receptor (CB1). J Pharmacol Exp Ther 1999; 289:1427-33. [PMID: 10336536] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
Two subtypes of the cannabinoid receptor (CB1 and CB2) are expressed in mammalian tissues. Although selective antagonists are available for each of the subtypes, most of the available cannabinoid agonists bind to both CB1 and CB2 with similar affinities. We have synthesized two analogs of N-arachidonylethanolamine (AEA), arachidonylcyclopropylamide (ACPA) and arachidonyl-2-chloroethylamide (ACEA), that bind to the CB1 receptor with very high affinity (KI values of 2.2 +/- 0.4 nM and 1.4 +/- 0.3 nM, respectively) and to the CB2 receptor with low affinity (KI values of 0.7 +/- 0.01 microM and 3.1 +/- 1.0 microM, respectively). Both ACPA and ACEA have the characteristics of agonists at the CB1 receptor; both inhibit forskolin-induced accumulation of cAMP in Chinese hamster ovary cells expressing the human CB1 receptor, and both analogs increase the binding of [35S]GTPgammaS to cerebellar membranes and inhibit electrically evoked contractions of the mouse vas deferens. ACPA and ACEA produce hypothermia in mice, and this effect is inhibited by coadministration of the CB1 receptor antagonist SR141716A. Therefore, ACPA and ACEA are high-affinity agonists of the CB1 receptor but do not bind the CB2 receptor, suggesting that structural analogs of AEA can be designed with considerable selectivity for the CB1 receptor over the CB2 receptor.
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Affiliation(s)
- C J Hillard
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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Abstract
Eicosanoids are a large group of biologically active metabolites of arachidonic acid and related C20 fatty acids. Many of these compounds contain hydroxyl groups which can be converted to oxo groups by a variety of substrate-specific dehydrogenases. In many cases, this results in a reduction in potency, but in others, such as the oxidation of 5-hydroxyeicosatetraenoic acid to its oxo metabolite 5-oxo-eicosatetraenoic acid, there is a dramatic increase in biological activity. Thus, it is often very important to analyze the relative amounts of oxo- and hydroxy-eicosanoids formed by various cells and tissues. The present study was designed to compare the chromatographic behavior of oxo-eicosanoids and their hydroxy counterparts in commonly used mobile phases for reversed-phase and normal-phase HPLC. We examined three groups of eicosanoids: prostaglandins, leukotriene B4 and some of its metabolites, and monohydroxy-eicosanoids and their oxo metabolites. We found that in reversed-phase HPLC, the retention times of oxo-eicosanoids were longer than those of the corresponding hydroxy-eicosanoids in mobile phases containing acetonitrile as the major organic component, whereas the reverse was true for mobile phases containing methanol. Normal-phase HPLC using mobile phases containing hexane, isopropanol, and acetic acid gave excellent separation of oxo- and hydroxy-eicosanoids. Increasing the concentration of acetic acid in the mobile phase selectively reduced the retention times of oxo-eicosatetraenoic acids compared to monohydroxy-eicosatetraenoic acids, whereas the reverse was true for isopropanol. Differences in the chromatographic behavior of oxo- and hydroxy-eicosanoids can be useful clues in the structural characterization of these compounds, as illustrated by the chromatographic properties of a complex series of LTB4 metabolites formed by rat neutrophils.
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Affiliation(s)
- W S Powell
- Meakins-Christie Laboratories, McGill University, Montreal, Quebec, Canada.
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Powell WS, Rokach J, Khanapure SP, Manna S, Hashefi M, Gravel S, Macleod RJ, Falck JR, Bhatt RK. Effects of metabolites of leukotriene B4 on human neutrophil migration and cytosolic calcium levels. J Pharmacol Exp Ther 1996; 276:728-36. [PMID: 8632343] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Leukotriene B4 (LTB4) is metabolized by beta-oxidation, omega-oxidation and the 12-hydroxyeicosanoid dehydrogenase/delta 10-reductase pathway. We have investigated the effects of metabolites formed by the latter pathway on calcium mobilization and migration in human neutrophils and have compared their potencies with those of other LTB4 derivatives. 12-Oxo-LTB4 and 10,11-dihydro-LTB4 were 60 to 100 times less potent than LTB4 in stimulating neutrophils, whereas 10,11-dihydro-12-oxo-LTB4 and 10,11-dihydro-12-epi-LTB4 exhibited still lower potencies. The 6-trans isomers of 12-oxo-LTB4 and 10,11-dihydro-12-oxo-LTB4 were much less potent than the 6-cis compounds. The EC50 values for biologically and chemically (6-cis) synthesized 12-oxo-LTB4 were similar, indicating that the 6,7-double bond is retained in the cis configuration in the biologically formed compound. Methylation of LTB4 markedly reduced its effect on cytosolic calcium levels, whereas addition of a 3-hydroxyl group had a much more modest effect. Modifications of the omega end of the molecule also resulted in lower potencies for calcium mobilization. Nearly all of the compounds tested desensitized neutrophils to LTB4-induced calcium mobilization, which suggests that their effects were mediated by receptors for the latter compound. However, modifications in the carboxyl end of the molecule had smaller effects on desensitization than on calcium mobilization, whereas the reverse was true for modifications in the omega end of the molecule. This suggests that the structural requirements for agonist-induced desensitization to LTB4 may differ to some extent from the requirements for calcium mobilization.
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Affiliation(s)
- W S Powell
- Meakins-Christie Laboratories, Respiratory Health Network of Centers of Excellence, McGill University, Montreal, Canada
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Manna S, Sinha A, Sadhukhan R, Chakrabarty SL. Purification, characterization and antitumor activity of L-asparaginase isolated from Pseudomonas stutzeri MB-405. Curr Microbiol 1995; 30:291-8. [PMID: 7766157 DOI: 10.1007/bf00295504] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
An L-asparaginase produced by Pseudomonas stutzeri MB-405 was isolated and characterized. After initial ammonium sulfate fractionation, the enzyme was purified by consecutive column chromatography on Sephadex G-100, Ca-hydroxylapatite, and DEAE-Sephadex A-50. The 665.5-fold purified enzyme thus obtained has the specific activity of 732.3 units mg protein-1 with an overall recovery of 27.2%. The apparent M(r) of the enzyme under nondenaturing and denaturing conditions was 34 kDa and 33 kDa respectively, and the isoelectric point was 6.38 +/- 0.02. It displayed optimum activity at pH 9.0 and 37 degrees C. The enzyme was very specific for L-asparagine and did not hydrolyze L-glutaminate. The Km of the L-asparaginase was found to be 1.45 x 10(-4) M towards L-asparagine and was competitively inhibited by 5-diazo-4-oxo-L- norvaline (DONV) with a Ki of 0.03 mM. Metal ions such as Mn2+, Zn2+, Hg2+, Fe3+, Ni2+, and Cd2+ potentially inhibited the enzyme activity. The activity was enhanced in the presence of thiol-protecting reagents such as DTT, 2-ME, and glutathione (reduced), but inhibited by PCMB and iodoacetamide. The tumor inhibition study with Dalton's lymphoma tumor cells in vivo indicated that this enzyme possesses antitumor properties.
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Affiliation(s)
- S Manna
- Department of Microbiology, Bose Institute, Calcutta, India
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