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Sarkar S, Paul S, Vishwakarma C, Kumar S, Verma G, Sainath M, Rapol UD, Santhanam MS. Nonexponential Decoherence and Subdiffusion in Atom-Optics Kicked Rotor. PHYSICAL REVIEW LETTERS 2017; 118:174101. [PMID: 28498690 DOI: 10.1103/physrevlett.118.174101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Indexed: 06/07/2023]
Abstract
Quantum systems lose coherence upon interaction with the environment and tend towards classical states. Quantum coherence is known to exponentially decay in time so that macroscopic quantum superpositions are generally unsustainable. In this work, slower than exponential decay of coherences is experimentally realized in an atom-optics kicked rotor system subjected to nonstationary Lévy noise in the applied kick sequence. The slower coherence decay manifests in the form of quantum subdiffusion that can be controlled through the Lévy exponent. The experimental results are in good agreement with the analytical estimates and numerical simulations for the mean energy growth and momentum profiles of an atom-optics kicked rotor.
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Verma G, Vishwakarma C, Dharmadhikari CV, Rapol UD. A compact atomic beam based system for Doppler-free laser spectroscopy of strontium atoms. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:033103. [PMID: 28372416 DOI: 10.1063/1.4977593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report the construction of a simple, light weight, and compact atomic beam spectroscopy cell for strontium atoms. The cell is built using glass blowing technique and includes a simple titanium sublimation pump for the active pumping of residual and background gases to maintain ultra-high vacuum. A commercially available and electrically heated dispenser source is used to generate the beam of Sr atoms. We perform spectroscopy on the 5s2S01→5s 5pP11 transition to obtain a well resolved Doppler free spectroscopic signal for frequency stabilization of the laser source. This design can be easily extended to other alkali and alkaline earth metals.
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Sardana K, Verma G. Propionibacterium acnes and the Th1/Th17 Axis, Implications in Acne Pathogenesis and Treatment. Indian J Dermatol 2017; 62:392-394. [PMID: 28794550 PMCID: PMC5527720 DOI: 10.4103/ijd.ijd_483_16] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Acne vulgaris is one of the most commonly seen conditions and the immunological link is a topic of active research. Recently, the Th17 pathway has been found to play a pivotal role in acne. The adaptive immune response toward Propionibacterium acnes leads to activation of Th17 axis. Consequently, the Th17 cytokines (IL-17, IL-1 β, IL-6, and tumor growth factor, in turn, activate the various pathogenic steps in acne. Drugs such as Vitamin D3 and isotretinoin which target the Th17 pathway may offer an additional pathway for their therapeutic response.
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Verma G, Sardana K, Gautam RK. Mutilating Keratoderma with Concomitant Alopecia and Keratoses Follicularis Spinulosa Decalvans: X-Linked Olmsted Syndrome and its Response to Isotretinoin. Indian Dermatol Online J 2017; 8:482-484. [PMID: 29204395 PMCID: PMC5707844 DOI: 10.4103/idoj.idoj_422_16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We report a case of mutilating keratoderma with alopecia and keratoses follicularis spinulosa decalvans (KFSD), which was initially diagnosed as ectodermal dysplasia and Olmsted syndrome but was revisited as a case of X-linked Olmsted (XLO) syndrome. We focus on this uncommon entity (XLO) to highlight the differentials of alopecia with palmoplantar keratoderma.
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Sastry NV, Singh DK, Thummar AD, Verma G, Hassan P. Effect of hydrocarbon surfactants on dexamethasone solubilization into silicone surfactant micelles in aqueous media and its release from agar films as carriers. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2016.11.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Verma G, Manjhi M, Kar HK. A pediatric case of primary cutaneous anaplastic large cell lymphoma: An unusual presentation. INDIAN JOURNAL OF PAEDIATRIC DERMATOLOGY 2017. [DOI: 10.4103/2319-7250.193029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Gupta N, Shastri S, Singh PK, Jana M, Mridha A, Verma G, Kabra M. Nasopharyngeal teratoma, congenital diaphragmatic hernia and Dandy-Walker malformation - a yet uncharacterized syndrome. Clin Genet 2016; 90:470-471. [PMID: 27506516 DOI: 10.1111/cge.12830] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 07/05/2016] [Accepted: 07/06/2016] [Indexed: 11/28/2022]
Abstract
An association of congenital diaphragmatic hernia, dandy walker malformation and nasopharyngeal teratoma is very rare. Here, we report a fourth case with this association where chromosomal microarray and whole exome sequencing (WES) was performed to understand the underlying genetic basis. Findings of few variants especially a novel variation in HIRA provided some insights. An association of congenital diaphragmatic hernia, dandy walker malformation and nasopharyngeal teratoma is very rare. Here, we report a fourth case with this association where chromosomal microarray and whole exome sequencing (WES) was performed to understand the underlying genetic basis. Findings of few variants especially a novel variation in HIRA provided some insights.
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Sawal N, Hans GDR, Verma G. Sexual practices, myths and misconceptions among long distance truck drivers in North India. QJM 2016; 109:467-72. [PMID: 26590208 DOI: 10.1093/qjmed/hcv205] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Long distance truck drivers and helpers constitute a high risk group for human immunodeficiency virus /acquired immune deficiency syndrome (HIV/AIDS). Despite increasing awareness of HIV/AIDS and safe sex practices, they still have a high incidence of new cases of HIV. AIMS This study carried out at an ART (anti-retroviral treatment) centre in North India aimed to evaluate the sexual myths and misconceptions prevalent among long distance drivers and helpers. DESIGN This was a retrospective study carried out at apex ART centre. METHODS Data were collected retrospectively from ART records of 129 long distance Truck drivers and 68 helpers. Details of socio-demographic characteristics, contact with commercial sex workers (CSW'S), pattern of condom usage with CSW'S and factors influencing it were studied. RESULTS We found that a significant number of drivers and helpers had sexual contact with CSW's and out of these, 30% of drivers and 50% of helpers reported not using condoms and instead resorting to methods like washing genitalia after sex with battery water/urine to avoid getting HIV. There was no significant relationship between pattern of condom usage and educational status, marital status and age. We also found that certain myths like sex with young CSW's was less likely to cause sexually transmitted diseases (STD's) and HIV were also widespread. CONCLUSION Owing to continuing prevalence of such sexual myths, long distance truck drivers and helpers do not use condoms while having sex with CSW's as they feel that they can enjoy sex with CSW's and still stay protected against STD's/HIV. It is imperative that this battery water/urine antiseptic myth be specifically targeted for better HIV control in this high risk group.
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Verma G, Barick KC, Shetake NG, Pandey BN, Hassan PA. Citrate-functionalized hydroxyapatite nanoparticles for pH-responsive drug delivery. RSC Adv 2016. [DOI: 10.1039/c6ra10659e] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Development of biocompatible citrate-functionalized hydroxyapatite nanoparticles for pH responsive delivery of doxorubicin.
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Verma G, Chan K, Swami A. Zealotry promotes coexistence in the rock-paper-scissors model of cyclic dominance. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:052807. [PMID: 26651744 DOI: 10.1103/physreve.92.052807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Indexed: 06/05/2023]
Abstract
Cyclic dominance models, such as the classic rock-paper-scissors (RPS) game, have found real-world applications in biology, ecology, and sociology. A key quantity of interest in such models is the coexistence time, i.e., the time until at least one population type goes extinct. Much recent research has considered conditions that lengthen coexistence times in an RPS model. A general finding is that coexistence is promoted by localized spatial interactions (low mobility), while extinction is fostered by global interactions (high mobility). That is, there exists a mobility threshold which separates a regime of long coexistence from a regime of rapid collapse of coexistence. The key finding of our paper is that if zealots (i.e., nodes able to defeat others while themselves being immune to defeat) of even a single type exist, then system coexistence time can be significantly prolonged, even in the presence of global interactions. This work thus highlights a crucial determinant of system survival time in cyclic dominance models.
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Verma S, Verma G, Shanker V, Tegta GR, Sharma A, Pandey ML. Facial lupus vulgaris of bilateral periorbital skin and conjunctiva: a case report and brief review. Indian J Med Microbiol 2015; 33:168-71. [PMID: 25560028 DOI: 10.4103/0255-0857.148438] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
A 22-year-old male presented to the Dermatology Department with bilateral plaque lesions distributed symmetrically over malar area, bridge of nose and upper eyelids progressing over 1 year 3 months. Lesion remained unhealed after antibiotic treatment. Microscopy and culture for fungal and mycobacterial infections were negative. The Mantoux test showed an exaggerated response and PCR was positive for Mycobacterium tuberculosis complex. Patient was treated successfully with anti-tubercular therapy.
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Rohiwal S, Tiwari A, Verma G, Pawar S. Preparation and evaluation of bovine serum albumin nanoparticles for ex vivo colloidal stability in biological media. Colloids Surf A Physicochem Eng Asp 2015. [DOI: 10.1016/j.colsurfa.2015.04.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Goswami A, Verma G, Hassan PA, Bhagwat SS. Equilibrium and Dynamic Surface Tension Behavior of Triblock Copolymer PEO-PPO-PEO in Aqueous Medium. J DISPER SCI TECHNOL 2015. [DOI: 10.1080/01932691.2014.936021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Waagen A, Verma G, Chan K, Swami A, D'Souza R. Effect of zealotry in high-dimensional opinion dynamics models. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 91:022811. [PMID: 25768556 DOI: 10.1103/physreve.91.022811] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Indexed: 06/04/2023]
Abstract
Most of the work on opinion dynamics models focuses on the case of two or three opinion types. We consider the case of an arbitrary number of opinions in the mean field case of the naming game model in which it is assumed the population is infinite and all individuals are neighbors. A particular challenge of the naming game model is that the number of variables, which corresponds to the number of possible sets of opinions, grows exponentially with the number of possible opinions. We present a method for generating mean field dynamical equations for the general case of k opinions. We calculate the steady states in two important special cases in arbitrarily high dimension: the case in which there exist zealots of only one type, and the case in which there are an equal number of zealots for each opinion. We show that in these special cases a phase transition occurs at critical values p(c) of the parameter p describing the fraction of zealots. In the former case, the critical value determines the threshold value beyond which it is not possible for the opinion with no zealots to be held by more nodes than the opinion with zealots, and this point remains fixed regardless of dimension. In the latter case, the critical point p(c) is the threshold value beyond which a stalemate between all k opinions is guaranteed, and we show that it decays precisely as a lognormal curve in k.
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Hassan PA, Rana S, Verma G. Making sense of Brownian motion: colloid characterization by dynamic light scattering. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:3-12. [PMID: 25050712 DOI: 10.1021/la501789z] [Citation(s) in RCA: 305] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Dynamic light scattering (DLS) has evolved as a fast, convenient tool for particle size analysis of noninteracting spherical colloids. In this historical review, we discuss the basic principle, data analysis, and important precautions to be taken while analyzing colloids using DLS. The effect of particle interaction, polydispersity, anisotropy, light absorption, and so forth, on measured diffusion coefficient is discussed. New developments in this area such as diffusing wave spectroscopy, particle tracking analysis, microrheological studies using DLS, and so forth, are discussed in a manner that can be understood by a beginner.
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Goswami A, Verma G, Hassan PA, Aswal VK, Bhagwat SS. Dynamic Interfacial Behavior of Poly(oxyethylene) Lauryl Ether Based Surfactant Mixtures. J DISPER SCI TECHNOL 2014. [DOI: 10.1080/01932691.2013.871554] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Verma G, Chuck AW, Jacobs P. Tuberculosis screening for long-term care: a cost-effectiveness analysis. Int J Tuberc Lung Dis 2014; 17:1170-7. [PMID: 23928166 DOI: 10.5588/ijtld.12.0934] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING Long-term care facilities in Canada, a low tuberculosis (TB) incidence country. OBJECTIVE To compare the impact and cost-effectiveness of three screening strategies for TB on entry to long-term care: no screening, screening for latent tuberculous infection (LTBI) using the tuberculin skin test (TST) or screening for active disease with a chest X-ray. DESIGN Cost effectiveness analysis. RESULTS With the LTBI screening strategy, the number needed to screen to prevent one active case was 1410 and the cost per case averted was Canadian $109 913. The number needed to screen to prevent one case using the active screening strategy was 1266, and the cost per case averted was $672 298. CONCLUSIONS Our findings suggest that TB screening strategies on entry to long-term care are costly, with large numbers needed to screen. Screening with TST was more cost-effective than chest X-ray screening. Higher risk of reactivation of LTBI is associated with improved cost-effectiveness of screening. Short time horizons and test performance characteristics place limitations on screening programmes in this setting. Future considerations include the changing demographics of the institutionalised elderly.
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Dey J, Kumar S, Srivastava A, Verma G, Hassan P, Aswal V, Kohlbrecher J, Ismail K. Effect of ethylene glycol on the special counterion binding and microstructures of sodium dioctylsulfosuccinate micelles. J Colloid Interface Sci 2014; 414:103-9. [DOI: 10.1016/j.jcis.2013.10.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 10/02/2013] [Accepted: 10/04/2013] [Indexed: 10/26/2022]
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Verma G, Hassan PA. Self assembled materials: design strategies and drug delivery perspectives. Phys Chem Chem Phys 2013; 15:17016-28. [DOI: 10.1039/c3cp51207j] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Bhattacharjee J, Verma G, Aswal VK, Patravale V, Hassan PA. Microstructure, drug binding and cytotoxicity of Pluronic P123–aerosol OT mixed micelles. RSC Adv 2013. [DOI: 10.1039/c3ra44983a] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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Verma G, Aswal V, Fritz-Popovski G, Shah C, Kumar M, Hassan P. Dilution induced thickening in hydrotrope-rich rod-like micelles. J Colloid Interface Sci 2011; 359:163-70. [DOI: 10.1016/j.jcis.2011.03.061] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Revised: 03/15/2011] [Accepted: 03/16/2011] [Indexed: 11/27/2022]
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Sharma VK, Mitra S, Verma G, Hassan PA, Garcia Sakai V, Mukhopadhyay R. Internal dynamics in SDS micelles: neutron scattering study. J Phys Chem B 2010; 114:17049-56. [PMID: 21138301 DOI: 10.1021/jp108274y] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The molecular dynamics of sodium dodecyl sulfate (SDS) micelle has been investigated using high-resolution incoherent quasielastic neutron scattering technique. Data analysis clearly shows presence of two distinct motions: whole micellar motion or global diffusion and faster internal motion of the SDS monomer. The global diffusion associated with the whole micelle is found to be Fickian in nature, and the corresponding diffusion coefficients are found to be consistent with those obtained from dynamic light scattering measurements. The internal motion is described with a model consistent with the structure of the micelle and which accounts for the flexibility of the chains. The SDS monomer consists of a head group, which lies on the surface of the globular micelle, and a tail that hangs from the head toward the center of the globule. Considering various factors like conformational changes of the SDS chains, bending, stretching of the chemical bonds, etc., the dynamics of the SDS molecules is successfully described by a model in which the hydrogen atoms undergo localized translational motion confined within spherical volumes. This volume increases linearly along the SDS chain such that the hydrogen atoms closer to the head group move within smaller spheres with lower diffusion constant than the hydrogen atoms away from the head group. This model is found to be consistent with the data over the whole temperature and concentration range. Diffusivity and the volume of the spheres are also found to increase with temperature. The effect of lowering the SDS concentration is found to be similar to that of increasing the temperature.
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Bhattacharjee J, Verma G, Aswal VK, Date AA, Nagarsenker MS, Hassan PA. Tween 80-sodium deoxycholate mixed micelles: structural characterization and application in doxorubicin delivery. J Phys Chem B 2010; 114:16414-21. [PMID: 21080698 DOI: 10.1021/jp108225r] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The objective of the present investigation is to develop and characterize anionic mixed micelles of two biocompatible surfactants, Tween 80 (T-80) and sodium deoxycholate (NaDC), and evaluate their potential in the delivery of doxorubicin hydrochloride (DOX), a cationic anticancer drug. The mixed micelles were characterized for their microstructure, intermicellar interactions, and doxorubicin binding ability by dynamic light scattering, small angle neutron scattering (SANS), viscosity, and optical absorption measurements. Salt-induced growth of the mixed micelles at different compositions suggests that both electrostatic interaction of the anionic bile salts and steric repulsion of the ethylene oxide groups in nonionic components are affected by the presence of electrolytes. Addition of bile salt molecules to T-80 micelles suppresses the salt-induced growth of nonionic T-80 micelles. SANS studies indicate that bile salt micelles are prolate ellipsoidal in shape, and the addition of T-80 transforms them toward a spherical shape. The anionic bile salt can successfully bind to the cationic drug doxorubicin. The in vitro cytotoxicity studies in various cancer cell lines revealed that DOX-loaded micelles have greater in vitro anticancer activity as compared to DOX solution, indicating their potential in pharmaceutical applications.
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Koshy P, Verma G, Aswal VK, Venkatesh M, Hassan PA. Viscoelastic Fluids Originated from Enhanced Solubility of Sodium Laurate in Cetyl Trimethyl Ammonium Bromide Micelles through Cooperative Self-Assembly. J Phys Chem B 2010; 114:10462-70. [DOI: 10.1021/jp104009f] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kadam Y, Bharatiya B, Hassan P, Verma G, Aswal V, Bahadur P. Effect of an amphiphilic diol (Surfynol®) on the micellar characteristics of PEO–PPO–PEO block copolymers in aqueous solutions. Colloids Surf A Physicochem Eng Asp 2010. [DOI: 10.1016/j.colsurfa.2010.04.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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