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Messersmith L, Kolhe C, Ladha A, Das P, Rao SR, Mohammady M, Conant E, Bose R, Ramanathan N, Patel A, Hibberd PL. Providing optimal care in the neonatal care units in India: How Covid-19 exacerbated existing barriers. PLOS Glob Public Health 2024; 4:e0000393. [PMID: 38696540 PMCID: PMC11065213 DOI: 10.1371/journal.pgph.0000393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 04/05/2024] [Indexed: 05/04/2024]
Abstract
Nearly one quarter (600,000) of all neonatal deaths worldwide per year occur in India. To reduce neonatal mortality, the Indian Ministry of Health and Family Welfare established neonatal care units, including neonatal intensive care units and specialized neonatal care units to provide immediate care at birth, resuscitation for asphyxiation, postnatal care, follow up for high-risk newborns, immunization, and referral for additional or complex healthcare services. Despite these efforts, neonatal mortality remains high, and measures taken to reduce mortality have been severely challenged by multiple problems caused by the Covid-19 pandemic. In this qualitative study, we conducted seven focus group discussions with newborn care unit nurses and pediatric residents and 35 key informant interviews with pediatricians, residents, nurses, annual equipment maintenance contractors, equipment manufacturers, and Ministry personnel in the Vidarbha region of Maharashtra between December 2019 and November 2020. The goal of the study was to understand barriers and facilitators to providing optimal care to neonates, including the challenges imposed by the Covid-19 pandemic. Covid-19 exacerbated existing barriers to providing optimal care to neonates in these newborn care units. As a result of Covid-19, we found the units were even more short-staffed than usual, with trained pediatric nurses and essential equipment diverted from newborn care to attend to patients with Covid-19. Regular training of neonatal nursing staff was also disrupted due to Covid-19, leaving many staff without the skills to provide optimate care to neonates. Infection control was also exacerbated by Covid-19. This study highlights the barriers to providing optimal care for neonates were made even more challenging during Covid-19 because of the diversion of critically important neonatal equipment and staff trained to use that equipment to Covid-19 wards. The barriers at the individual, facility, and systems levels will remain challenging as the Covid-19 pandemic continues.
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Affiliation(s)
- Lisa Messersmith
- Department of Global Health, Boston University School of Public Health, Boston, Massachusetts, United States of America
| | | | - Alyana Ladha
- Department of Global Health, Boston University School of Public Health, Boston, Massachusetts, United States of America
| | - Prabir Das
- Lata Medical Research Foundation, Nagpur, India
| | - Sowmya R. Rao
- Department of Global Health, Boston University School of Public Health, Boston, Massachusetts, United States of America
| | - Marym Mohammady
- Nexleaf Analytics, Los Angeles, California, United States of America
| | - Emily Conant
- Nexleaf Analytics, Los Angeles, California, United States of America
| | - Rejesh Bose
- Nexleaf Analytics, Los Angeles, California, United States of America
| | - Nithya Ramanathan
- Nexleaf Analytics, Los Angeles, California, United States of America
| | - Archana Patel
- Lata Medical Research Foundation, Nagpur, India
- Datta Meghe Institute of Medical Sciences, Wardha, India
| | - Patricia L. Hibberd
- Department of Global Health, Boston University School of Public Health, Boston, Massachusetts, United States of America
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Selvan BR, Suneesh AS, Ramanathan N. Diglycolamic acid coated cation exchange adsorbent for uranium removal by extraction chromatography. J Radioanal Nucl Chem 2023. [DOI: 10.1007/s10967-023-08869-6] [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: 04/01/2023]
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3
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Chandra S, Mahapatra N, Ramanathan N, Sundararajan K. The Prominence of Facilitator π-Holes: The Classic N←N Pnictogen Bonding in Nitrobenzene-Ammonia Dimer with its Structural Elucidation and Experimental Characterization at Low Temperatures. Chemistry 2023; 29:e202203976. [PMID: 36648371 DOI: 10.1002/chem.202203976] [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: 12/20/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 01/18/2023]
Abstract
The nitrogen of nitro group is a paradigmatic pnictogen due the presence of a π-hole and a number of studies have been performed recently on prototypical nitromethane (NM). Homodimers and heterodimers of NM are sustained by π-hole driven pnictogen bonds hosted by nitrogen. To understand the effect of substitution on this π-hole and thus the pnictogen bond, heterodimers of nitrobenzene (NB; phenyl substitution in place of methyl) with ammonia (AM) have been probed, as a test case, using matrix isolation infrared spectroscopy and ab initio computations. Of the four structures optimized on the potential energy surface the energetically dominant global minimum, stabilized by π-hole driven O=N←N pnictogen bonding with co-operative N-H←O hydrogen bonding, was experimentally identified at low temperatures. A comparison of the pnictogen bonding of NB-AM dimers with NM counterpart (NM-AM dimers) divulged the dominance of electrostatic origin of pnictogen bonding in both the class of dimers. The reduced strength of pnictogen bonding in NB-AM dimers in comparison to NM-AM dimers was discerned, which has been established to be a consequence of the reduced electrostatic potential at the π-hole of NB relative to that in NM. The strength of π-hole driven pnictogen bond was directly correlated with the binding energy and the infrared shifts in the signature vibrational bands of the NB, NM and AM submolecules due to dimerization under matrix isolated conditions at low temperatures.
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Affiliation(s)
- Swaroop Chandra
- Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, 603102, Tamilnadu, India.,Indira Gandhi Centre for Atomic Research, A CI of Homi Bhabha National Institute, Kalpakkam, 603102, Tamilnadu, India
| | - Nandalal Mahapatra
- Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, 603102, Tamilnadu, India.,Indira Gandhi Centre for Atomic Research, A CI of Homi Bhabha National Institute, Kalpakkam, 603102, Tamilnadu, India
| | - N Ramanathan
- Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, 603102, Tamilnadu, India.,Indira Gandhi Centre for Atomic Research, A CI of Homi Bhabha National Institute, Kalpakkam, 603102, Tamilnadu, India
| | - K Sundararajan
- Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, 603102, Tamilnadu, India.,Indira Gandhi Centre for Atomic Research, A CI of Homi Bhabha National Institute, Kalpakkam, 603102, Tamilnadu, India
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Prathibha T, Kumar S, Chandra S, Maji S, Ramanathan N. The Complexation of Lanthanides by Glycolamide Extractants: Evidences from Electronic Spectroscopy and DFT Calculations. Inorganica Chim Acta 2023. [DOI: 10.1016/j.ica.2023.121396] [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: 01/19/2023]
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5
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Suryaprasad B, Chandra S, Ramanathan N, Sundararajan K. Collective stabilization through n→π* and P…π phosphorous bonding with cooperative halogen and hydrogen bonding in POCl3-Nitrile dimers: Matrix isolation infrared spectroscopic and ab initio computational studies. J Mol Struct 2023. [DOI: 10.1016/j.molstruc.2023.134916] [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: 01/07/2023]
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6
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Rajani P, Chandra S, Ramanathan N, Sundararajan K, Rao CB. Exploring the conformations of Dibutyl Phosphonate (DBP): A matrix isolation infrared spectroscopic and density functional theory studies. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.133762] [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: 11/30/2022]
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7
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Messersmith LJ, Ladha A, Kolhe C, Patel A, Summers JS, Rao SR, Das P, Mohammady M, Conant E, Ramanathan N, Hibberd PL. Poor power quality is a major barrier to providing optimal care in special neonatal care units (SNCU) in Central India. Gates Open Res 2022. [DOI: 10.12688/gatesopenres.13479.1] [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: 11/20/2022] Open
Abstract
Background: Approximately 25% of all neonatal deaths worldwide occur in India. The Indian Government has established Special Neonatal Care Units (SNCUs) in district and sub-district level hospitals to reduce neonatal mortality, but mortality rates have stagnated. Reasons include lack of personnel and training and sub-optimal quality of care. The role of medical equipment is critical for the care of babies, but its role in improving neonatal outcomes has not been well studied. Methods: In a qualitative study, we conducted seven focus group discussions with SNCU nurses and pediatric residents and thirty-five key informant interviews and with pediatricians, residents, nurses, annual equipment maintenance contractors, equipment manufacturers, and Ministry of Health personnel in Maharashtra between December 2019 and November 2020. The goal of the study was to understand challenges to SNCU care. In this paper, we focus on current gaps and future needs for SNCU equipment, quality of the power supply, and use of SNCU equipment. Results: Respondents described a range of issues but highlighted poor power quality as an important cause of equipment malfunction. Other concerns were lack of timely repair that resulted in needed equipment being unavailable for neonatal care. Participants recommended procuring uninterrupted power supply (UPS) to protect equipment, improving quality/durability of equipment to withstand constant use, ensuring regular proactive maintenance for SNCU equipment, and conducting local power audits to discern and address the causes of power fluctuations. Conclusions: Poor power quality and its negative impact on equipment function are major unaddressed concerns of those responsible for the care and safety of babies in SNCUs in Central India. Further research on the power supply and protection of neonatal equipment is needed to determine a cost-effective way to improve access to supportive care in SNCUs and desired improvements in neonatal mortality rates.
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Suneesh A, Selvan BR, Ramanathan N. A chemically functionalized hydroxyacetamide anchored polymeric adsorbent for the selective separation of zirconium from acidic aqueous solutions. REACT FUNCT POLYM 2022. [DOI: 10.1016/j.reactfunctpolym.2022.105173] [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: 11/24/2022]
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9
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Mahapatra N, Chandra S, Ramanathan N, Sundararajan K. Experimental proof for σ and π-hole driven dual pnicogen bonding in phosphoryl chloride-nitromethane heterodimers: A combined matrix isolation infrared and ab initio computational studies. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2021.132045] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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10
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Sarkar S, Chandra S, Suneesh A, Ramanathan N, Sundararajan K, Suresh A, Sivaraman N. Elucidating the extraction behaviour of tri-n-alkyl phosphates and tris(2-methylbutyl) phosphate with nitrates of uranyl and tetravalent metal ions from infrared spectroscopy and dynamic light scattering studies: A distinct correlation from conformational changes and variation in size of aggregates. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2021.131133] [Citation(s) in RCA: 1] [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: 10/20/2022]
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11
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Suneesh A, Selvan BR, Prathibha T, Sriram S, Ramanathan N. Extraction chromatography based separation of zirconium(IV) from simulated high-level liquid waste using N,N-di-octyl-2-hydroxyacetamide impregnated amberlite XAD-7 resin. Chemical Engineering Journal Advances 2021. [DOI: 10.1016/j.ceja.2021.100182] [Citation(s) in RCA: 1] [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: 11/27/2022] Open
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12
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Sruthi P, Ramanathan N, Sundararajan K. Pentavalent P…N phosphorus bonding in the heterodimers of POCl3…nitrogen bases: Evidence from matrix isolation infrared spectroscopy and Ab initio computations. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2021.130638] [Citation(s) in RCA: 4] [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: 01/04/2023]
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Chandra S, Suryaprasad B, Ramanathan N, Sundararajan K. Nitrogen as a pnicogen?: evidence for π-hole driven novel pnicogen bonding interactions in nitromethane-ammonia aggregates using matrix isolation infrared spectroscopy and ab initio computations. Phys Chem Chem Phys 2021; 23:6286-6297. [PMID: 33688865 DOI: 10.1039/d0cp06273a] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The role of nitrogen, the first member of the pnicogen group, as an electron donor in hypervalent non-covalent interactions has been established long ago, while observation of its electron accepting capability is still elusive experimentally, and remains quite intriguing, conceptually. In the light of minimal computational exploration of this novel class of pnicogen bonding so far, the present work provides experimental proof with unprecedented clarity, for the existence of N(acceptor)N(donor) interaction using the model nitromethane (NM) molecule with ammonia (AM) as a Lewis base in NM-AM aggregates. The NM-AM dimer, in which the nitrogen atom of NM (as a unique pnicogen) accepts electrons from AM (the traditional electron donor), was synthesized at low temperatures under isolated conditions within inert gas matrixes and was characterized using infrared spectroscopy. The experimental generation of the NM-AM dimer stabilized via NN interaction has strong corroboration from ab initio calculations. Furthermore, confirmation regarding the directional prevalence of this NN interaction over C-HN and N-HO hydrogen bonding is elucidated quantitatively by quantum theory of atoms in molecules (QTAIM), electrostatic potential mapping (ESP), natural bond orbital (NBO), non-covalent interaction (NCI) and energy decomposition (ED) analyses. The present study also allows the extension of σ-hole/π-hole driven interactions to the atoms of the second period, in spite of their low polarizability.
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Affiliation(s)
- Swaroop Chandra
- Homi Bhabha National Institute, Materials Chemistry & Metal Fuel Cycle Group, Indira Gandhi Center for Atomic Research, Kalpakkam - 603102, Tamil Nadu, India.
| | - B Suryaprasad
- Homi Bhabha National Institute, Materials Chemistry & Metal Fuel Cycle Group, Indira Gandhi Center for Atomic Research, Kalpakkam - 603102, Tamil Nadu, India.
| | - N Ramanathan
- Homi Bhabha National Institute, Materials Chemistry & Metal Fuel Cycle Group, Indira Gandhi Center for Atomic Research, Kalpakkam - 603102, Tamil Nadu, India.
| | - K Sundararajan
- Homi Bhabha National Institute, Materials Chemistry & Metal Fuel Cycle Group, Indira Gandhi Center for Atomic Research, Kalpakkam - 603102, Tamil Nadu, India.
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14
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Rout A, Kumar S, Ramanathan N. Probing the coordination of europium(III) in a functionalized ionic liquid using luminescence spectroscopy. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.115109] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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15
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Suryaprasad B, Chandra S, Ramanathan N, Sundararajan K. Pentavalent P…π phosphorus bonding with associated Cl…π halogen bonding in influencing the geometry of POCl3-Phenylacetylene heterodimers: Evidence from matrix isolation infrared spectroscopy and ab initio computations. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2020.129288] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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16
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Sarkar S, Chandra S, Suryaprasad B, Ramanathan N, Sundararajan K, Suresh A. Conformational topography of tris(2-methylbutyl) phosphate and the influence of methyl branching at the non-hyperconjugative carbon on the conformational landscape: insights from matrix isolation infrared spectroscopy and DFT computations. Phys Chem Chem Phys 2020; 22:24372-24392. [PMID: 33084659 DOI: 10.1039/d0cp03403g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The branching of a methyl group in a linear chain has a profound influence on the conformational morphology as it wields a strong control in reducing a large number of conformations. To unravel the effect of branching on the second non-hyperconjugative carbon atom on the conformational landscape, the conformations of tris(2-methylbutyl)phosphate (T2MBP) were studied using Density Functional Theory (DFT) computations and matrix isolation infrared spectroscopy. Experimentally, T2MBP along with N2/Ar/Kr/Xe gases was effusively expanded and deposited at a low temperature of 12 K, which was subsequently probed using infrared spectroscopy. The computations of all the conformations were accomplished using the B3LYP level of theory with the 6-311++G(d,p) basis set. A dimethyl(2-methylbutyl) phosphate (DM2MBP) prototype, a molecule containing a single 2-methylbutyl moiety, was examined for its conformations. Computations predicted 18 and 9 conformations each for the 'gauche' and 'trans' families, respectively, in which the third branched carbon completely influences the orientation of the fourth carbon, which simplifies the conformational problem of DM2MBP. Of the 18 and 9 bunches each in the 'gauche' and 'trans' families, only 7 and 3 conformations, respectively, became energetically important, which when extrapolated to T2MBP resulted in 343 and 147 conformational possibilities. The factor of degeneracy further reduced these numbers and a total of 168 conformations effectively contribute to the conformational composition of T2MBP in the gas phase. The role of stereo electronic and steric factors prevalent in the conformational clusters of T2MBP was unravelled respectively using natural bond orbital and non-covalent interaction analyses.
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Affiliation(s)
- Subramee Sarkar
- Homi Bhabha National Institute, Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu, India.
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Sruthi PK, Chandra S, Ramanathan N, Sundararajan K. Unusual blue to red shifting of C-H stretching frequency of CHCl 3 in co-operatively P⋯Cl phosphorus bonded POCl 3-CHCl 3 heterodimers at low temperature inert matrixes. J Chem Phys 2020; 153:174305. [PMID: 33167652 DOI: 10.1063/5.0031162] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Heterodimers of POCl3-CHCl3 were generated in Ne, Ar, and Kr matrixes at low temperatures and were studied using infrared spectroscopy. The remarkable role of co-operative pentavalent phosphorus bonding in the stabilization of the structure dictated by hydrogen bonding is deciphered. The complete potential energy surface of the heterodimer was scanned by ab initio and density functional theory computational methodologies. The hydrogen bond between the phosphoryl oxygen of POCl3 and C-H group of CHCl3 in heterodimers induces a blue-shift in the C-H stretching frequency within the Ne matrix. However, in Ar and Kr matrixes, the C-H stretching frequency is exceptionally red-shifted in stark contrast with Ne. The plausibility of the Fermi resonance by the C-H stretching vibrational mode with higher order modes in the heterodimers has been eliminated as a possible cause within Ar and Kr matrixes by isotopic substitution (CDCl3) experiments. To evaluate the influence of matrixes as a possible cause of red-shift, self-consistent Iso-density polarized continuum reaction field model was applied. This conveyed the important role of the dielectric matrixes in inducing the fascinating vibrational shift from blue (Ne) to red (Ar and Kr) due to the matrix specific transmutation of the POCl3-CHCl3 structure. The heterodimer produced in the Ne matrix possesses a cyclic structure stabilized by hydrogen bonding with co-operative phosphorus bonding, while in Ar and Kr the generation of an acyclic open structure stabilized solely by hydrogen bonding is promoted. Compelling justification regarding the dispersion force based influence of matrix environments in addition to the well-known dielectric influence is presented.
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Affiliation(s)
- P K Sruthi
- Homi Bhabha National Institute, Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India
| | - Swaroop Chandra
- Homi Bhabha National Institute, Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India
| | - N Ramanathan
- Homi Bhabha National Institute, Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India
| | - K Sundararajan
- Homi Bhabha National Institute, Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India
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Gopi R, Ramanathan N, Sundararajan K. The structure of benzonitrile-water complex as unveiled by matrix isolation infrared spectroscopy: Is it linear or cyclic at low temperatures? J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.128636] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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19
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Chandra S, Suryaprasad B, Ramanathan N, Sundararajan K. Dominance of unique Pπ phosphorus bonding with π donors: evidence using matrix isolation infrared spectroscopy and computational methodology. Phys Chem Chem Phys 2020; 22:20771-20791. [PMID: 32909555 DOI: 10.1039/d0cp02880k] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Albeit the first account of hypervalentπ interactions has been reported with halogenπ interactions, the feasibility of their extension to other hypervalent atoms as possible Lewis acids is still open. In this work, the role of phosphorus as an acceptor from the π electron cloud (Pπ pnicogen or phosphorus bonding) in PCl3-C2H2 and PCl3-C2H4 heterodimers is explored, by combining matrix isolation infrared spectroscopy with ab initio and DFT computational methodologies. The respective potential energy surfaces of the PCl3-C2H2 and PCl3-C2H4 heterodimers reveal unique minima stabilized by a concert of reasonably strong to weak interactions, of which Pπ phosphorus bonding was energetically dominant. Heterodimers, trimers and tetramers bound primarily by this unique phosphorus bond were generated at low temperatures. The dominance of phosphorus bonding in the PCl3-C2H2 and PCl3-C2H4 heterodimers over other interactions (such as Hπ, HCl, HP, Clπ and lone pair-π interactions) was confirmed and substantiated using extended quantum theory of atoms in molecules, natural bond orbital, electrostatic potential mapping and energy decomposition analyses. The following inferences in correlation with results from non-covalent-interaction analysis offer a complete understanding of the nature of the Pπ phosphorus bonding interactions. The significance of electrostatic forces kinetically favoring the formation of phosphorus bonded heterodimers, in addition to thermodynamic stabilization, is demonstrated experimentally.
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Affiliation(s)
- Swaroop Chandra
- Homi Bhabha National Institute, Materials Chemistry & Metal Fuel Cycle Group, Indira Gandhi Center for Atomic Research, Kalpakkam - 603102, Tamil Nadu, India.
| | - B Suryaprasad
- Homi Bhabha National Institute, Materials Chemistry & Metal Fuel Cycle Group, Indira Gandhi Center for Atomic Research, Kalpakkam - 603102, Tamil Nadu, India.
| | - N Ramanathan
- Homi Bhabha National Institute, Materials Chemistry & Metal Fuel Cycle Group, Indira Gandhi Center for Atomic Research, Kalpakkam - 603102, Tamil Nadu, India.
| | - K Sundararajan
- Homi Bhabha National Institute, Materials Chemistry & Metal Fuel Cycle Group, Indira Gandhi Center for Atomic Research, Kalpakkam - 603102, Tamil Nadu, India.
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20
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Sarkar S, Ramanathan N, Sruthi P, Sundararajan K. Computational and experimental evidence of N–H…π and cooperative πN…π∗ interactions in pyrrole…benzene and pyrrole…ethylene heterodimers at low temperatures. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.127983] [Citation(s) in RCA: 1] [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: 10/24/2022]
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21
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Sarkar S, Sruthi P, Ramanathan N, Sundararajan K. Experimental evidence of N–H⋯N hydrogen bonding in the heterodimers of pyrrole with nitrogen bases. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2019.127511] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [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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22
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Sarkar S, Sruthi PK, Ramanathan N, Sundararajan K. Strong proton-shared hydrogen bonding in a methyl imidazole⋯HCl complex: evidence from matrix isolation infrared spectroscopy and ab initio computations. NEW J CHEM 2020. [DOI: 10.1039/d0nj00029a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Evidence for proton-shared hydrogen bonding is provided in a methyl imidazole⋯HCl complex using matrix isolation infrared spectroscopy and ab initio computations.
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Affiliation(s)
- Shubhra Sarkar
- Materials Chemistry & Metal Fuel Cycle Group
- Homi Bhabha National Institute
- Indira Gandhi Center for Atomic Research
- Kalpakkam.603102
- India
| | - P. K. Sruthi
- Materials Chemistry & Metal Fuel Cycle Group
- Homi Bhabha National Institute
- Indira Gandhi Center for Atomic Research
- Kalpakkam.603102
- India
| | - N. Ramanathan
- Materials Chemistry & Metal Fuel Cycle Group
- Homi Bhabha National Institute
- Indira Gandhi Center for Atomic Research
- Kalpakkam.603102
- India
| | - K. Sundararajan
- Materials Chemistry & Metal Fuel Cycle Group
- Homi Bhabha National Institute
- Indira Gandhi Center for Atomic Research
- Kalpakkam.603102
- India
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Ramanathan N, Sarkar S, Sundararajan K. Prototypical cyclohexane dimers: spectroscopic evidence for σ stacking at low temperatures. Phys Chem Chem Phys 2020; 22:905-913. [DOI: 10.1039/c9cp05237b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In this work, the first unambiguous spectroscopic evidence for the existence of σ stacking interactions in cyclohexane dimers has been provided using matrix isolation infrared spectroscopy.
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Affiliation(s)
- N. Ramanathan
- Materials Chemistry and Metal Fuel Cycle Group
- Homi Bhabha National Institute
- Indira Gandhi Centre for Atomic Research
- Kalpakkam 603 102
- India
| | - Shubhra Sarkar
- Materials Chemistry and Metal Fuel Cycle Group
- Homi Bhabha National Institute
- Indira Gandhi Centre for Atomic Research
- Kalpakkam 603 102
- India
| | - K. Sundararajan
- Materials Chemistry and Metal Fuel Cycle Group
- Homi Bhabha National Institute
- Indira Gandhi Centre for Atomic Research
- Kalpakkam 603 102
- India
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Ramanathan N, Sundararajan K, Sarkar S, Sruthi P. Exploring reactive species of chlorocarbons and oxygen atom generation at low temperatures using electron gun assembly. Chem Phys 2019. [DOI: 10.1016/j.chemphys.2019.05.016] [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: 11/28/2022]
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Sarkar S, Ramanathan N, Sruthi PK, Sundararajan K. Conformations of diethyl ether and its interaction with pyrrole at low temperatures. Spectrochim Acta A Mol Biomol Spectrosc 2019; 213:361-369. [PMID: 30721851 DOI: 10.1016/j.saa.2019.01.076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/25/2019] [Accepted: 01/26/2019] [Indexed: 06/09/2023]
Abstract
Conformations of diethyl ether (DEE) were studied at low temperatures in N2 and Ar matrixes. Computations performed at B3LYP/aug-cc-pVDZ level of theory yielded three minima corresponding to tt, tg± and g±g± conformers of DEE. Of the three, the tt and tg± conformers of DEE were experimentally identified in N2 and Ar matrixes. Furthermore, hydrogen bonded complexes of pyrrole (py) with DEE have been investigated using Density Functional Theory (DFT) and matrix isolation infrared spectroscopy. Computations performed at B3LYP level of theory using aug-cc-pVDZ basis set on pyrrole with tt and tg± conformers of DEE gave py-DEE-tt and py-DEE-tg± complexes, both characterized by NH⋯O interaction. Experimental evidence for the formation of py-DEE-tt and py-DEE-tg± complexes was affirmed from the shifts in the NH stretching, NH bending regions of pyrrole and COC and CH stretching regions of DEE. NBO analysis was carried out to understand the charge-transfer delocalization interactions in the conformers of DEE and its hydrogen bonded complexes.
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Affiliation(s)
- Shubhra Sarkar
- Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Homi Bhabha National Institute, Kalpakkam 603 102, India
| | - N Ramanathan
- Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Homi Bhabha National Institute, Kalpakkam 603 102, India
| | - P K Sruthi
- Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Homi Bhabha National Institute, Kalpakkam 603 102, India
| | - K Sundararajan
- Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Homi Bhabha National Institute, Kalpakkam 603 102, India.
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Sruthi PK, Sarkar S, Ramanathan N, Sundararajan K. Elusive hypervalent phosphorus⋯π interactions: evidence for paradigm transformation from hydrogen to phosphorus bonding at low temperatures. Phys Chem Chem Phys 2019; 21:12250-12264. [DOI: 10.1039/c9cp01925a] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A paradigm transformation from hydrogen to phosphorus bonding is found to depend on the proton affinity of the interacting π-systems.
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Affiliation(s)
- P. K. Sruthi
- Materials Chemistry and Metal Fuel Cycle Group
- Homi Bhabha National Institute
- Indira Gandhi Centre for Atomic Research
- Kalpakkam-603 102
- India
| | - Shubhra Sarkar
- Materials Chemistry and Metal Fuel Cycle Group
- Homi Bhabha National Institute
- Indira Gandhi Centre for Atomic Research
- Kalpakkam-603 102
- India
| | - N. Ramanathan
- Materials Chemistry and Metal Fuel Cycle Group
- Homi Bhabha National Institute
- Indira Gandhi Centre for Atomic Research
- Kalpakkam-603 102
- India
| | - K. Sundararajan
- Materials Chemistry and Metal Fuel Cycle Group
- Homi Bhabha National Institute
- Indira Gandhi Centre for Atomic Research
- Kalpakkam-603 102
- India
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Comulada WS, Swendeman D, Rezai R, Ramanathan N. Time Series Visualizations of Mobile Phone-Based Daily Diary Reports of Stress, Physical Activity, and Diet Quality in Mostly Ethnic Minority Mothers: Feasibility Study. JMIR Form Res 2018; 2:e11062. [PMID: 30684407 PMCID: PMC6334694 DOI: 10.2196/11062] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 10/08/2018] [Accepted: 10/09/2018] [Indexed: 11/18/2022] Open
Abstract
Background Health behavior patterns reported through daily diary data are important to understand and intervene upon at the individual level in N-of-1 trials and related study designs. There is often interest in relationships between multiple outcomes, such as stress and health behavior. However, analyses often utilize regressions that evaluate aggregate effects across individuals, and standard analyses target single outcomes. Objective This paper aims to illustrate how individuals’ daily reports of stress and health behavior (time series) can be explored using visualization tools. Methods Secondary analysis was conducted on 6 months of daily diary reports of stress and health behavior (physical activity and diet quality) from mostly ethnic minority mothers who pilot-tested a self-monitoring mobile health app. Time series with minimal missing data from 14 of the 44 mothers were analyzed. Correlations between stress and health behavior within each time series were reported as a preliminary step. Stress and health behavior time series patterns were visualized by plotting moving averages and time points where mean shifts in the data occurred (changepoints). Results Median correlation was small and negative for associations of stress with physical activity (r=−.14) and diet quality (r=−.08). Moving averages and changepoints for stress and health behavior were aligned for some participants but not for others. A third subset of participants exhibited little variation in stress and health behavior reports. Conclusions Median correlations in this study corroborate prior findings. In addition, time series visualizations highlighted variations in stress and health behavior across individuals and time points, which are difficult to capture through correlations and regression-based summary measures.
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Affiliation(s)
- W Scott Comulada
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA, United States
| | - Dallas Swendeman
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA, United States
| | - Roxana Rezai
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA, United States
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Sarkar S, Ramanathan N, Sundararajan K. Experimental Evidence of Synergistic Interactions in Pyrrole–Phenol Complexes at Low Temperatures under Isolated Conditions. J Phys Chem A 2018; 122:9073-9083. [DOI: 10.1021/acs.jpca.8b09076] [Citation(s) in RCA: 5] [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: 11/29/2022]
Affiliation(s)
- Shubhra Sarkar
- Materials Chemistry & Metal Fuel Cycle Group, Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu 603 102, India
| | - N. Ramanathan
- Materials Chemistry & Metal Fuel Cycle Group, Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu 603 102, India
| | - K. Sundararajan
- Materials Chemistry & Metal Fuel Cycle Group, Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu 603 102, India
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Swendeman D, Comulada WS, Koussa M, Worthman CM, Estrin D, Rotheram-Borus MJ, Ramanathan N. Longitudinal Validity and Reliability of Brief Smartphone Self-Monitoring of Diet, Stress, and Physical Activity in a Diverse Sample of Mothers. JMIR Mhealth Uhealth 2018; 6:e176. [PMID: 30249576 PMCID: PMC6231816 DOI: 10.2196/mhealth.9378] [Citation(s) in RCA: 14] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 05/10/2018] [Accepted: 06/21/2018] [Indexed: 12/14/2022] Open
Abstract
Background Multiple strategies can be used when self-monitoring diet, physical activity, and perceived stress, but no gold standards are available. Although self-monitoring is a core element of self-management and behavior change, the success of mHealth behavioral tools depends on their validity and reliability, which lack evidence. African American and Latina mothers in the United States are high-priority populations for apps that can be used for self-monitoring of diet, physical activity, and stress because the body mass index (BMI) of mothers typically increases for several years after childbirth and the risks of obesity and its’ sequelae diseases are elevated among minority populations. Objective To examine the intermethod reliability and concurrent validity of smartphone-based self-monitoring via ecological momentary assessments (EMAs) and use of daily diaries for diet, stress, and physical activity compared with brief recall measures, anthropometric biomeasures, and bloodspot biomarkers. Methods A purposive sample (n=42) of primarily African American (16/42, 39%) and Latina (18/42, 44%) mothers was assigned Android smartphones for using Ohmage apps to self-monitor diet, perceived stress, and physical activity over 6 months. Participants were assessed at 3- and 6-month follow-ups. Recall measures included brief food frequency screeners, physical activity assessments adapted from the National Health and Nutrition Examination Survey, and the nine-item psychological stress measure. Anthropometric biomeasures included BMI, body fat, waist circumference, and blood pressure. Bloodspot assays for Epstein–Barr virus and C-reactive protein were used as systemic load and stress biomarkers. EMAs and daily diary questions assessed perceived quality and quantity of meals, perceived stress levels, and moderate, vigorous, and light physical activity. Units of analysis were follow-up assessments (n=29 to n=45 depending on the domain) of the participants (n=29 with sufficient data for analyses). Correlations, R2 statistics, and multivariate linear regressions were used to assess the strength of associations between variables. Results Almost all participants (39/42, 93%) completed the study. Intermethod reliability between smartphone-based EMAs and diary reports and their corresponding recall reports was highest for stress and diet; correlations ranged from .27 to .52 (P<.05). However, it was unexpectedly low for physical activity; no significant associations were observed. Concurrent validity was demonstrated for diet EMAs and diary reports on systolic blood pressure (r=−.32), C-reactive protein level (r=−.34), and moderate and vigorous physical activity recalls (r=.35 to.48), suggesting a covariation between healthy diet and physical activity behaviors. EMAs and diary reports on stress were not associated with Epstein–Barr virus and C-reactive protein level. Diary reports on moderate and vigorous physical activity were negatively associated with BMI and body fat (r=−.35 to −.44, P<.05). Conclusions Brief smartphone-based EMA use may be valid and reliable for long-term self-monitoring of diet, stress, and physical activity. Lack of intermethod reliability for physical activity measures is consistent with prior research, warranting more research on the efficacy of smartphone-based self-monitoring of self-management and behavior change support.
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Affiliation(s)
- Dallas Swendeman
- Department of Psychiatry and Biobehavioral Sciences, David Geffon School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Warren Scott Comulada
- Department of Psychiatry and Biobehavioral Sciences, David Geffon School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Maryann Koussa
- Department of Psychiatry and Biobehavioral Sciences, David Geffon School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Carol M Worthman
- Department of Anthropology, Emory University, Atlanta, GA, United States
| | - Deborah Estrin
- Cornell Tech, Cornell University, New York, NY, United States
| | - Mary Jane Rotheram-Borus
- Department of Psychiatry and Biobehavioral Sciences, David Geffon School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Nithya Ramanathan
- Department of Computer Science, University of California, Los Angeles, Los Angeles, CA, United States
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Ramanathan N, Sarkar S, Sundararajan K, Chandrasekar A, Sankaran K, Suresh A. Influence of Branching on the Conformational Space: Case Study of Tri-sec-butyl Phosphate Using Matrix Isolation Infrared Spectroscopy and DFT Computations. J Phys Chem A 2018; 122:8229-8242. [DOI: 10.1021/acs.jpca.8b08157] [Citation(s) in RCA: 5] [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: 11/28/2022]
Affiliation(s)
- N. Ramanathan
- Materials Chemistry & Metal Fuel Cycle Group, Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu, India
| | - Shubhra Sarkar
- Materials Chemistry & Metal Fuel Cycle Group, Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu, India
| | - K. Sundararajan
- Materials Chemistry & Metal Fuel Cycle Group, Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu, India
| | - Aditi Chandrasekar
- Materials Chemistry & Metal Fuel Cycle Group, Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu, India
| | - K. Sankaran
- Materials Chemistry & Metal Fuel Cycle Group, Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu, India
| | - A. Suresh
- Materials Chemistry & Metal Fuel Cycle Group, Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu, India
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Sarkar S, Ramanathan N, Sundararajan K. Effect of Methyl Substitution on the N–H···O Interaction in Complexes of Pyrrole with Water, Methanol, and Dimethyl Ether: Matrix Isolation Infrared Spectroscopy and ab Initio Computational Studies. J Phys Chem A 2018; 122:2445-2460. [DOI: 10.1021/acs.jpca.8b00023] [Citation(s) in RCA: 6] [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: 11/28/2022]
Affiliation(s)
- Shubhra Sarkar
- Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, India
- Homi Bhabha National Institute, Kalpakkam 603 102, India
| | - N. Ramanathan
- Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, India
- Homi Bhabha National Institute, Kalpakkam 603 102, India
| | - K. Sundararajan
- Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, India
- Homi Bhabha National Institute, Kalpakkam 603 102, India
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Sruthi PK, Ramanathan N, Sarkar S, Sundararajan K. Pentavalent phosphorus as a unique phosphorus donor in POCl3 homodimer and POCl3–H2O heterodimer: matrix isolation infrared spectroscopic and computational studies. Phys Chem Chem Phys 2018; 20:22058-22075. [DOI: 10.1039/c8cp03937b] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Phosphorus, an important element among the pnicogen group, opens up avenues for experimental and computational explorations of its interaction in a variety of compounds.
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Affiliation(s)
- P. K. Sruthi
- Materials Chemistry & Metal Fuel Cycle Group
- Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research
- Kalpakkam 603 102
- India
| | - N. Ramanathan
- Materials Chemistry & Metal Fuel Cycle Group
- Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research
- Kalpakkam 603 102
- India
| | - Shubhra Sarkar
- Materials Chemistry & Metal Fuel Cycle Group
- Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research
- Kalpakkam 603 102
- India
| | - K. Sundararajan
- Materials Chemistry & Metal Fuel Cycle Group
- Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research
- Kalpakkam 603 102
- India
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33
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Lennon P, Atuhaire B, Yavari S, Sampath V, Mvundura M, Ramanathan N, Robertson J. Root cause analysis underscores the importance of understanding, addressing, and communicating cold chain equipment failures to improve equipment performance. Vaccine 2017; 35:2198-2202. [PMID: 28364931 DOI: 10.1016/j.vaccine.2016.09.068] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [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: 05/11/2016] [Accepted: 09/30/2016] [Indexed: 11/30/2022]
Abstract
Vaccine cold chain equipment (CCE) in developing countries is often exposed to harsh environmental conditions, such as extreme temperatures and humidity, and is subject to many additional challenges, including intermittent power supply, insufficient maintenance capacity, and a scarcity of replacement parts. Together, these challenges lead to high failure rates for refrigerators, potentially damaging vaccines and adversely affecting immunization coverage. Providing a sustainable solution for improving CCE performance requires an understanding of the root causes of failure. Project teams conducted small-scale studies to determine the root causes of CCE failure in selected locations in Uganda and Mozambique. The evaluations covered 59 failed refrigerators and freezers in Uganda and 27 refrigerators in Mozambique. In Uganda, the vast majority of failures were due to a cooling unit fault in one widely used refrigerator model. In Mozambique, 11 of the 27 problems were attributable to solar refrigerators with batteries that were unable to hold a charge, and another eight problems were associated with a need to adjust thermostat settings. The studies showed that tracking and evaluation of equipment performance and failure can yield important, actionable information for a range of stakeholders, including local CCE technicians, the ministry of health, equipment manufacturers, and international partners such as the United Nations Children's Fund, World Health Organization, and Gavi, the Vaccine Alliance. Collaborative efforts to systematically collect and communicate data on CCE performance and causes of failure will help to improve the efficiency and reach of immunization programs in low- and middle-income countries.
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Affiliation(s)
- Pat Lennon
- PATH, 2201 Westlake Avenue, Suite 200, Seattle, WA 98121, USA.
| | | | - Shahrzad Yavari
- Nexleaf Analytics, 2356 Pelham Avenue, Los Angeles, CA 90064, USA.
| | - Vidya Sampath
- VillageReach, 2900 Eastlake Avenue East, Suite 230, Seattle, WA 98102, USA.
| | - Mercy Mvundura
- PATH, 2201 Westlake Avenue, Suite 200, Seattle, WA 98121, USA.
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Sarkar S, Ramanathan N, Gopi R, Sundararajan K. Pyrrole multimers and pyrrole-acetylene hydrogen bonded complexes studied in N2 and para-H2 matrixes using matrix isolation infrared spectroscopy and ab initio computations. J Mol Struct 2017. [DOI: 10.1016/j.molstruc.2017.07.110] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [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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Affiliation(s)
- N. Ramanathan
- Materials Chemistry & Metal Fuel Cycle Group, ‡Homi Bhabha National Institute, Indira Gandhi Center for Atomic Research, Kalpakkam 603102, Tamil Nadu, India
| | - K. Sankaran
- Materials Chemistry & Metal Fuel Cycle Group, ‡Homi Bhabha National Institute, Indira Gandhi Center for Atomic Research, Kalpakkam 603102, Tamil Nadu, India
| | - K. Sundararajan
- Materials Chemistry & Metal Fuel Cycle Group, ‡Homi Bhabha National Institute, Indira Gandhi Center for Atomic Research, Kalpakkam 603102, Tamil Nadu, India
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36
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Ramanathan N, Sundararajan K, Viswanathan KS. Conformational Landscape of Tri-n-butyl Phosphate: Matrix Isolation Infrared Spectroscopy and Systematic Computational Analysis. J Phys Chem A 2017; 121:6108-6121. [DOI: 10.1021/acs.jpca.7b05006] [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: 11/29/2022]
Affiliation(s)
- N. Ramanathan
- Materials
Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu, India
| | - K. Sundararajan
- Materials
Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu, India
| | - K. S. Viswanathan
- Department of Chemical Sciences, Indian Institute of Science Education & Research, Sector 81, Mohali 140306, Punjab, India
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Gopi R, Ramanathan N, Sundararajan K. Experimental evidence for the blue-shifted hydrogen-bonded complexes of CHF 3 with π-electron donors. Spectrochim Acta A Mol Biomol Spectrosc 2017; 181:137-147. [PMID: 28351820 DOI: 10.1016/j.saa.2017.03.048] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 03/10/2017] [Accepted: 03/20/2017] [Indexed: 06/06/2023]
Abstract
Blue-shifted hydrogen-bonded complexes of fluoroform (CHF3) with benzene (C6H6) and acetylene (C2H2) have been investigated using matrix isolation infrared spectroscopy and ab initio computations. For CHF3-C6H6 complex, calculations performed at the B3LYP and MP2 levels of theory using 6-311++G (d,p) and aug-cc-pVDZ basis sets discerned two minima corresponding to a 1:1 hydrogen-bonded complex. The global minimum correlated to a structure, where the interaction is between the hydrogen of CHF3 and the π-electrons of C6H6 and a weak local minimum was stabilized through H…F interaction. For the CHF3-C2H2 complex, computation performed at MP2/aug-cc-pVDZ level of theory yielded two minima, corresponding to the cyclic C-H…π complex A (global) and a linear C-H…F (n-σ) complex B (local). Experimentally a blue-shift of 32.3cm-1 and 7.7cm-1 was observed in the ν1 C-H stretching mode of CHF3 sub-molecule in Ar matrix for the 1:1 C-H…π complexes of CHF3 with C6H6 and C2H2 respectively. Natural bond orbital (NBO), Atoms-in-molecule (AIM) and energy decomposition (EDA) analyses were carried out to explain the blue-shifting and the nature of the interaction in these complexes.
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Affiliation(s)
- R Gopi
- Materials Chemistry & Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India; Homi Bhabha National Institute, Kalpakkam 603102, India
| | - N Ramanathan
- Materials Chemistry & Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India
| | - K Sundararajan
- Materials Chemistry & Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India; Homi Bhabha National Institute, Kalpakkam 603102, India.
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van Heerden A, Harris DM, van Rooyen H, Barnabas RV, Ramanathan N, Ngcobo N, Mpiyakhe Z, Comulada WS. Perceived mHealth barriers and benefits for home-based HIV testing and counseling and other care: Qualitative findings from health officials, community health workers, and persons living with HIV in South Africa. Soc Sci Med 2017; 183:97-105. [PMID: 28475904 DOI: 10.1016/j.socscimed.2017.04.046] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [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: 11/16/2016] [Revised: 02/13/2017] [Accepted: 04/25/2017] [Indexed: 10/19/2022]
Abstract
mHealth has been proposed to address inefficiencies in the current South African healthcare system, including home-based HIV testing and counseling (HTC) programs. Yet wide-scale adoption of mHealth has not occurred. Even as infrastructure barriers decrease, a need to better understand perceived adoption barriers by stakeholders remains. We conducted focus group discussions (FGD) in South Africa in 2016 with 10 home-based HTC field staff, 12 community health workers (CHWs) and 10 persons living with HIV (PLH). Key informant (KI) interviews were conducted with five health officials. Perceptions about current home-based HTC practices, future mHealth systems and the use of biometrics for patient identification were discussed, recorded and transcribed for qualitative analysis. Themes were based on a conceptual model for perceived mHealth service quality. Stakeholders brought up a lack of communication in sharing patient health information between clinics, between clinics and CHWs, and between clinics and patients as major barriers to care that mHealth can address. CHWs need better patient information from clinics in terms of physical location and health status to plan visitation routes and address patient needs. CHWs perceive that communication barriers create distrust towards them by clinic staff. PLH want automated appointment and medication reminders. KI see mHealth as a way to improve health information transfer to government officials to better allocate healthcare resources. Stakeholders are also optimistic about the ability for biometrics to improve patient identification but disagreed as to which biometrics would be acceptable, especially in older patients. All stakeholders provided useful information towards the development of mHealth systems. Hospitals are adopting patient-centered approaches that solicit feedback from patients and incorporate them into decision-making processes. A similar approach is needed in the development of mHealth systems. Further, such systems are critical to the successful extension of the health system from health facilities into people's homes.
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Affiliation(s)
- Alastair van Heerden
- Human and Social Development Research Programme, Human Sciences Research Council, South Africa; Developmental Pathways to Health Research Unit, School of Community Medicine, University of the Witwatersrand, South Africa.
| | - Danielle M Harris
- Department of Psychiatry & Biobehavioral Sciences, Global Center for Children and Families, University of California, Los Angeles, 10920 Wilshire Blvd, Suite 350, Los Angeles, CA 90024, United States.
| | - Heidi van Rooyen
- Human and Social Development Research Programme, Human Sciences Research Council, South Africa.
| | - Ruanne V Barnabas
- Global Health and Medicine, University of Washington, Seattle, WA, United States.
| | | | - Nkosinathi Ngcobo
- Human and Social Development Research Programme, Human Sciences Research Council, South Africa.
| | - Zukiswa Mpiyakhe
- Human and Social Development Research Programme, Human Sciences Research Council, South Africa.
| | - W Scott Comulada
- Department of Psychiatry & Biobehavioral Sciences, Global Center for Children and Families, University of California, Los Angeles, 10920 Wilshire Blvd, Suite 350, Los Angeles, CA 90024, United States.
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Gopi R, Ramanathan N, Sundararajan K. Probing C-H⋯N interaction in acetylene-benzonitrile complex using matrix isolation infrared spectroscopy and DFT computations. Chem Phys 2017. [DOI: 10.1016/j.chemphys.2016.11.019] [Citation(s) in RCA: 2] [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: 11/30/2022]
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40
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Ramanathan N, Sundararajan K, Gopi R, Sankaran K. Photooxidation of Trimethyl Phosphite in Nitrogen, Oxygen, and para-Hydrogen Matrixes at Low Temperatures. J Phys Chem A 2017; 121:2121-2131. [DOI: 10.1021/acs.jpca.6b12296] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [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)
- N. Ramanathan
- Materials
Chemistry and Metal Fuel Cycle Group and ‡Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, India
| | - K. Sundararajan
- Materials
Chemistry and Metal Fuel Cycle Group and ‡Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, India
| | - R. Gopi
- Materials
Chemistry and Metal Fuel Cycle Group and ‡Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, India
| | - K. Sankaran
- Materials
Chemistry and Metal Fuel Cycle Group and ‡Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, India
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Sreenivasulu B, Suresh A, Rajeswari S, Ramanathan N, Antony MP, Sivaraman N, Joseph M. Physicochemical properties and radiolytic degradation studies on tri-iso-amyl phosphate (TiAP). RADIOCHIM ACTA 2016. [DOI: 10.1515/ract-2016-2674] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The solvent composed of tri-iso-amyl phosphate (TiAP) in n-dodecane (n-DD) is regarded as a promising candidate for reprocessing of spent fuel. In this context, the radiolytic degradation of a solution of TiAP in n-dodecane was investigated by irradiating the solvent to various absorbed dose levels of γ-radiation. The neat extractant or a solution of extractant in n-dodecane was irradiated in the presence of nitric acid. Physicochemical properties such as density, viscosity and interfacial tension (IFT) were measured for unirradiated and irradiated solutions. The extent of degradation was determined by measuring the variation in extraction behavior of U(VI) and Pu(IV) with irradiated solvent systems. Uranium and plutonium retention with irradiated solvents was also measured. The distribution ratio of uranium and plutonium increased with increase in absorbed dose. Effect of alpha degradation was studied by plutonium retention as a function of time using 1.1 M TiAP/n-DD. Laser desorption/ionization mass spectrometric technique was employed to identify the possible radiolytic degradation products. Similar studies were also carried out with tri-n-butyl phosphate (TBP) based solvent system under identical experimental conditions and the results are compared.
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Affiliation(s)
- B. Sreenivasulu
- Chemistry Group, Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102, Tamil Nadu, India
| | - A. Suresh
- Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102, Tamil Nadu, India
| | - S. Rajeswari
- Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102, Tamil Nadu, India
| | - N. Ramanathan
- Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102, Tamil Nadu, India
| | - M. P. Antony
- Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102, Tamil Nadu, India
| | - Nagarajan Sivaraman
- Chemistry Group, Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102, Tamil Nadu, India , Fax: 27480065
| | - M. Joseph
- Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102, Tamil Nadu, India
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Sundararajan K, Gopi R, Ramanathan N. Conformations of propargyl alcohol and its interaction with acetylene: A matrix isolation infrared and DFT computations. J Mol Struct 2016. [DOI: 10.1016/j.molstruc.2016.05.047] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Sundararajan K, Sankaran K, Ramanathan N, Gopi R. Production and characterization of para-hydrogen gas for matrix isolation infrared spectroscopy. J Mol Struct 2016. [DOI: 10.1016/j.molstruc.2016.03.068] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Ramanathan N, Kamaruddin KA, Othman A, Mustafa F, Awang MS. Cystic Meningioma Masquerading as a Metastatic Tumor: A Case Report. Malays J Med Sci 2016; 23:92-94. [PMID: 27418876 PMCID: PMC4934725] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 06/30/2015] [Indexed: 06/06/2023] Open
Abstract
Cystic meningioma is a rare form of intracranial meningioma. Meningiomas are typically solid tumors but may rarely have cystic components. The diagnosis of cystic meningioma is clinically challenging as the finding of multiple intra-axial tumors, including metastatic tumors, is relatively common. We report a case of cystic meningioma initially diagnosed as a metastatic tumor from a recurrence of acute lymphoid leukemia. However, postoperative histopathological examination demonstrated an atypical meningioma.
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Affiliation(s)
- Nithya Ramanathan
- Unit of Neurosurgery, Hospital Tengku Ampuan Afzan, 25100 Kuantan, Pahang, Malaysia
| | | | - Aizzat Othman
- Unit of Neurosurgery, Hospital Tengku Ampuan Afzan, 25100 Kuantan, Pahang, Malaysia
| | - Fadhli Mustafa
- Department of Pathology, Hospital Tengku Ampuan Afzan, 25100 Kuantan, Pahang, Malaysia
| | - Mohamed Saufi Awang
- International Islamic University Malaysia, Bandar Indera Mahkota, 25200 Kuantan, Pahang, Malaysia
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45
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Rajapandi S, Ramanathan N, Pourouchottamane R, Thiruvenkadan AK, Kumar VRS, Pankaj PK, Rajendiran AS. Analysis of Reproductive Traits of Broiler Rabbits Reared in Sub-temperate Climate of Kodai Hills, Tamil Nadu, India. Vet World 2016; 8:1045-50. [PMID: 27047196 PMCID: PMC4774770 DOI: 10.14202/vetworld.2015.1045-1050] [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] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 07/25/2015] [Accepted: 08/04/2015] [Indexed: 11/18/2022] Open
Abstract
Aim: The present study was carried out at Institute Rabbit Farm of Southern Regional Research Centre, Mannavanur, Kodaikanal, Tamil Nadu, India having sub-temperate climate with winter temperature during night hours going below 0°C with an objective of finding the influence of different factors such as breed, year, season and parity on different reproductive traits of broiler rabbits in order to come out with the best strategies for improving the productivity. Materials and Methods: A total of 1793 records (946 White Giant and 847 Soviet Chinchilla) for weight at mating (WM), weight at kindling (WK), gestation length (GL), litter size at birth (LSB) and litter size at weaning (LSW), litter weight at birth (LWB), and litter weight at weaning (LWW) were collected in the period between 2000 and 2009 and the data was analyzed using general linear model option of SAS 9.2. Results: The overall mean GL, WM, WK, LSB, LSW, LWB, and LWW were 31.68±0.04 days, 3.65±0.01 kg, 3.84±0.01 kg, 6.91±0.08, 5.49±0.09, 387.62±4.07 g, and 4.66±0.07 kg, respectively. The breed has significantly influenced GL, WK, LSW, LWB, and LWW. The LSB, LSW, LWB, and LWW were 7.05±0.11, 5.76±0.13, 399.55±5.88 g, and 4.87±0.10 kg, respectively in White Giant and corresponding values for Soviet Chinchilla were 6.78±0.11, 5.22±0.12, 375.91±5.64 g, and 4.46±0.09 kg, respectively. The year of kindling had significantly affected all the reproductive traits under study and is varying over different years. The parity significantly influenced the WM, WK, and LWW. The LWW increased from first (4.16±0.21 kg) to second parity (4.86±0.19 kg) and remained in the same range from third parity onward. WM was significantly higher in spring season (3.72±0.02) than the animals in rainy (3.59±0.02) and winter season (3.65±0.02). Better reproductive performance in terms of higher LSB, LSW, LWB, and LWW as observed in the present study might be due to conducive environmental conditions prevailing in the region. Conclusion: The significant effects of the non-genetic factors like year of kindling on all reproductive traits, season, and parity on some of the traits in rabbit breeds are indications that any future production enhancement strategy must take into consideration the environment by providing additional care, feed supplementation and better shelter management to the rabbits, so that the full genetic potential can be realized.
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Affiliation(s)
- S Rajapandi
- Department of Agriculture and Animal Husbandry, Gandhi Gram Rural Institute, Gandhigram, Dindigul, Tamil Nadu, India
| | - N Ramanathan
- Department of Agriculture and Animal Husbandry, Gandhi Gram Rural Institute, Gandhigram, Dindigul, Tamil Nadu, India
| | - R Pourouchottamane
- Southern Regional Research Centre, ICAR - CSWRI, Mannavanur, Kodaikanal, Tamil Nadu, India
| | - A K Thiruvenkadan
- Department of Bio Statistics, Veterinary College & Research Institute (TANUVAS), Namakkal, Tamil Nadu, India
| | - V Ramesh Saravana Kumar
- Department of Livestock Production Management, Veterinary College & Research Institute (TANUVAS), Namakkal, Tamil Nadu, India
| | - P K Pankaj
- Section of Transfer of Technology, ICAR - Central Research Institute for Dryland Agriculture,Saidabad, Hyderabad,Telangana, India
| | - A S Rajendiran
- Southern Regional Research Centre, ICAR - CSWRI, Mannavanur, Kodaikanal, Tamil Nadu, India
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Olson MR, Graham E, Hamad S, Uchupalanun P, Ramanathan N, Schauer JJ. Quantification of elemental and organic carbon in atmospheric particulate matter using color space sensing-hue, saturation, and value (HSV) coordinates. Sci Total Environ 2016; 548-549:252-259. [PMID: 26802353 DOI: 10.1016/j.scitotenv.2016.01.032] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Revised: 01/06/2016] [Accepted: 01/07/2016] [Indexed: 05/22/2023]
Abstract
A fast and cost effective application of color sensing was used to quantify color coordinates of atmospheric particulate matter collected on filters to quantify elemental and organic carbon (EC/OC) loading. This is a unique and novel approach for estimating OC composition. The method used a colorimeter and digital photography to obtain XYZ color space values and mathematically transformed them to HSV cylindrical-coordinates; a quantification method was applied to estimate the NIOSH and IMPROVE (TOR) EC/OC loadings from a set of globally diverse PM samples. When applied to 315 samples collected at three US EPA Chemical Speciation Network (CSN) sampling sites, the HSV model proved to be a robust method for EC measurement with an R(2)=0.917 for predicted versus measured loading results and a CV(RMSE)=16.1%. The OC quantified from the same sample filters had an R(2)=0.671 and a CV(RMSE)=24.8% between the predicted and measured results. The method was applied to NIOSH EC/OC results from a set of samples from rural China, Bagdad, and the San Joaquin Valley, CA, and the EC and OC CV(RMSE) were 30.8% and 49.3%, respectively. Additionally, the method was applied to samples with color quantified by a digital photographic image (DPI) with EC results showing good agreement with a CV(RMSE) of 22.6%. OC concentrations were not captured as accurately with the DPI method, with a CV(RMSE) of 77.5%. The method's low analytical cost makes it a valuable tool for estimating EC/OC exposure in developing regions and for large scale monitoring campaigns.
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Affiliation(s)
- Michael R Olson
- University of Wisconsin-Madison, Department of Civil and Environmental Engineering, WSEL 660 North Park Street, Madison, WI 53706, USA
| | - Eric Graham
- Nexleaf Analytics, 2356 Pelham Ave., Los Angeles, CA 90064, USA; Central Washington University, Department of Biology, Ellensburg, WA 98926, USA
| | - Samera Hamad
- University of Wisconsin-Madison, Department of Civil and Environmental Engineering, WSEL 660 North Park Street, Madison, WI 53706, USA
| | - Pajean Uchupalanun
- University of Wisconsin-Madison, Department of Civil and Environmental Engineering, WSEL 660 North Park Street, Madison, WI 53706, USA
| | | | - James J Schauer
- University of Wisconsin-Madison, Department of Civil and Environmental Engineering, WSEL 660 North Park Street, Madison, WI 53706, USA.
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Ramanathan N, Sundararajan K, Vidya K, Jemmis ED. Non-covalent C-Cl…π interaction in acetylene-carbon tetrachloride adducts: Matrix isolation infrared and ab initio computational studies. Spectrochim Acta A Mol Biomol Spectrosc 2016; 157:69-78. [PMID: 26722673 DOI: 10.1016/j.saa.2015.12.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 11/23/2015] [Accepted: 12/14/2015] [Indexed: 06/05/2023]
Abstract
Non-covalent halogen-bonding interactions between π cloud of acetylene (C2H2) and chlorine atom of carbon tetrachloride (CCl4) have been investigated using matrix isolation infrared spectroscopy and quantum chemical computations. The structure and the energies of the 1:1 C2H2-CCl4 adducts were computed at the B3LYP, MP2 and M05-2X levels of theory using 6-311++G(d,p) basis set. The computations indicated two minima for the 1:1 C2H2-CCl4 adducts; with the C-Cl…π adduct being the global minimum, where π cloud of C2H2 is the electron donor. The second minimum corresponded to a C-H…Cl adduct, in which C2H2 is the proton donor. The interaction energies for the adducts A and B were found to be nearly identical. Experimentally, both C-Cl…π and C-H…Cl adducts were generated in Ar and N2 matrixes and characterized using infrared spectroscopy. This is the first report on halogen bonded adduct, stabilized through C-Cl…π interaction being identified at low temperatures using matrix isolation infrared spectroscopy. Atoms in Molecules (AIM) and Natural Bond Orbital (NBO) analyses were performed to support the experimental results. The structures of 2:1 ((C2H2)2-CCl4) and 1:2 (C2H2-(CCl4)2) multimers and their identification in the low temperature matrixes were also discussed.
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Affiliation(s)
- N Ramanathan
- Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, India
| | - K Sundararajan
- Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, India.
| | - K Vidya
- School of Chemistry, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala 695016, India
| | - Eluvathingal D Jemmis
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012, India.
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Abstract
A phosphorous trichloride (PCl3)–benzene (C6H6) heterodimer was generated in a low temperature N2 matrix and was characterized using infrared spectroscopy.
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Affiliation(s)
- N. Ramanathan
- Chemistry Group
- Indira Gandhi Center for Atomic Research
- Kalpakkam – 603102
- India
| | - K. Sankaran
- Chemistry Group
- Indira Gandhi Center for Atomic Research
- Kalpakkam – 603102
- India
| | - K. Sundararajan
- Chemistry Group
- Indira Gandhi Center for Atomic Research
- Kalpakkam – 603102
- India
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49
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Tangmunarunkit H, Hsieh CK, Longstaff B, Nolen S, Jenkins J, Ketcham C, Selsky J, Alquaddoomi F, George D, Kang J, Khalapyan Z, Ooms J, Ramanathan N, Estrin D. Ohmage. ACM T INTEL SYST TEC 2015. [DOI: 10.1145/2717318] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Participatory sensing (PS) is a distributed data collection and analysis approach where individuals, acting alone or in groups, use their personal mobile devices to systematically explore interesting aspects of their lives and communities [Burke et al. 2006]. These mobile devices can be used to capture diverse spatiotemporal data through both intermittent self-report and continuous recording from on-board sensors and applications.
Ohmage (http://ohmage.org) is a modular and extensible open-source, mobile to Web PS platform that records, stores, analyzes, and visualizes data from both prompted self-report and continuous data streams. These data streams are authorable and can dynamically be deployed in diverse settings. Feedback from hundreds of behavioral and technology researchers, focus group participants, and end users has been integrated into ohmage through an iterative participatory design process. Ohmage has been used as an enabling platform in more than 20 independent projects in many disciplines. We summarize the PS requirements, challenges and key design objectives learned through our design process, and ohmage system architecture to achieve those objectives. The flexibility, modularity, and extensibility of ohmage in supporting diverse deployment settings are presented through three distinct case studies in education, health, and clinical research.
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Ramanathan N, Brahmmananda Rao CVS, Sankaran K, Sundararajan K. Unraveling the Conformational Landscape of Triallyl Phosphate: Matrix Isolation Infrared Spectroscopy and Density Functional Theory Computations. J Phys Chem A 2015; 119:4017-31. [DOI: 10.1021/acs.jpca.5b00889] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [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)
- N. Ramanathan
- Chemistry
Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu, India
| | | | - K. Sankaran
- Chemistry
Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu, India
| | - K. Sundararajan
- Chemistry
Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu, India
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