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Abstract
We study the formation of spin-1 symbiotic spinor solitons in a quasi-one- (quasi-1D) and quasi-two-dimensional (quasi-2D) hyperfine spin F=1 ferromagnetic Bose-Einstein condensate (BEC). The symbiotic solitons necessarily have a repulsive intraspecies interaction and are bound due to an attractive interspecies interaction. Due to a collapse instability in higher dimensions, an additional spin-orbit coupling is necessary to stabilize a quasi-2D symbiotic spinor soliton. Although a quasi-1D symbiotic soliton has a simple Gaussian-type density distribution, novel spatial periodic structure in density is found in quasi-2D symbiotic SO-coupled spinor solitons. For a weak SO coupling, the quasi-2D solitons are of the (-1,0,+1) or (+1,0,-1) type with intrinsic vorticity and multiring structure, for Rashba or Dresselhaus SO coupling, respectively, where the numbers in the parentheses are angular momenta projections in spin components F_{z}=+1,0,-1, respectively. For a strong SO coupling, stripe and superlattice solitons, respectively, with a stripe and square-lattice modulation in density, are found in addition to the multiring solitons. The stationary states were obtained by imaginary-time propagation of a mean-field model; dynamical stability of the solitons was established by real-time propagation over a long period of time. The possibility of the creation of such a soliton by removing the trap of a confined spin-1 BEC in a laboratory is also demonstrated.
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Affiliation(s)
- S K Adhikari
- Instituto de Física Teórica, Universidade Estadual Paulista - UNESP, 01.140-070 São Paulo, São Paulo, Brazil
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Adhikari SK. Spatial order in a two-dimensional spin-orbit-coupled spin-1/2 condensate: superlattice, multi-ring and stripe formation. J Phys Condens Matter 2021; 33:425402. [PMID: 34289454 DOI: 10.1088/1361-648x/ac16ab] [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] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 07/21/2021] [Indexed: 06/13/2023]
Abstract
We demonstrate the formation of stable spatially-ordered states in auniformand alsotrappedquasi-two-dimensional (quasi-2D) Rashba or Dresselhaus spin-orbit (SO) coupled pseudo spin-1/2 Bose-Einstein condensate using the mean-field Gross-Pitaevskii equation. For weak SO coupling, one can have a circularly-symmetric (0, +1)- or (0, -1)-type multi-ring state with intrinsic vorticity, for Rashba or Dresselhaus SO coupling, respectively, where the numbers in the parentheses denote the net angular momentum projection in the two components, in addition to a circularly-asymmetric degenerate state with zero net angular momentum projection. For intermediate SO couplings, in addition to the above two types, one can also have states with stripe pattern in component densities with no periodic modulation in total density. The stripe state continues to exist for large SO coupling. In addition, a new spatially-periodic state appears in the uniform system: asuperlatticestate, possessing some properties of asupersolid, with a square-lattice pattern in component densities and also in total density. In a trapped system the superlattice state is slightly different with multi-ring pattern in component density and a square-lattice pattern in total density. For an equal mixture of Rashba and Dresselhaus SO couplings, in both uniform and trapped systems, only stripe states are found for all strengths of SO couplings. In a uniform system all these states are quasi-2D solitonic states.
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Affiliation(s)
- S K Adhikari
- Instituto de Física Teórica, Universidade Estadual Paulista-UNESP, 01.140-070 São Paulo, São Paulo, Brazil
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Adhikari SK. Supersolid-like states in a two-dimensional trapped spin-orbit-coupled spin-1 condensate. J Phys Condens Matter 2021; 33:265402. [PMID: 33882472 DOI: 10.1088/1361-648x/abfa5f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 04/21/2021] [Indexed: 06/12/2023]
Abstract
We study supersolid-like states in a quasi-two-dimensional trapped Rashba and Dresselhaus spin-orbit (SO) coupled spin-1 condensate. For small strengths of SO couplingγ(γ⪅ 0.75), in the ferromagnetic phase, circularly-symmetric (0, ±1, ±2)- and (∓1, 0, ±1)-type states are formed where the numbers in the parentheses denote the angular momentum of the vortex at the center of the components and where the upper (lower) sign correspond to Rashba (Dresselhaus) coupling; in the antiferromagnetic phase, only (∓1, 0, ±1)-type states are formed. For large strengths of SO coupling, supersolid-like superlattice and superstripe states are formed in the ferromagnetic phase. In the antiferromagnetic phase, for large strengths of SO coupling, supersolid-like superstripe and multi-ring states are formed. For an equal mixture of Rashba and Dresselhaus SO couplings, only a superstripe state is found. All these states are found to be dynamically stable and hence accessible in an experiment and will enhance the fundamental understanding of crystallization onto radially periodic states in solids.
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Affiliation(s)
- S K Adhikari
- Instituto de Física Teórica, Universidade Estadual Paulista-UNESP, 01.140-070 São Paulo, São Paulo, Brazil
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Adhikari SK. Vortex-lattice formation in a spin-orbit coupled rotating spin-1 condensate. J Phys Condens Matter 2021; 33:065404. [PMID: 33120369 DOI: 10.1088/1361-648x/abc5d7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We study the vortex-lattice formation in a rotating Rashba spin-orbit (SO) coupled quasi-two-dimensional (quasi-2D) hyper-fine spin-1 spinor Bose-Einstein condensate (BEC) in the x-y plane using a numerical solution of the underlying mean-field Gross-Pitaevskii equation. In this case, the non-rotating Rashba SO-coupled spinor BEC can have topological excitation in the form of vortices of different angular momenta in the three components, e.g. the (0, +1, +2)- and (-1, 0, +1)-type states in ferromagnetic and anti-ferromagnetic spinor BEC: the numbers in the parenthesis denote the intrinsic angular momentum of the vortex states of the three components with the negative sign denoting an anti-vortex. The presence of these states with intrinsic vorticity breaks the symmetry between rotation with vorticity along the z and -z axes and thus generates a rich variety of vortex-lattice and anti-vortex-lattice states in a rotating quasi-2D spin-1 spinor ferromagnetic and anti-ferromagnetic BEC, not possible in a scalar BEC. For weak SO coupling, we find two types of symmetries of these states - hexagonal and 'square'. The hexagonal (square) symmetry state has vortices arranged in closed concentric orbits with a maximum of 6, 12, 18… (8, 12, 16…) vortices in successive orbits. Of these two symmetries, the square vortex-lattice state is found to have the smaller energy.
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Affiliation(s)
- S K Adhikari
- Instituto de Física Teórica, Universidade Estadual Paulista-UNESP, 01.140-070 São Paulo, São Paulo, Brazil
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Dhimal ML, Rana N, Aryal B, Adhikari SK, Shrestha R, Gyanwali P, Dhimal M. Age and Gender Differences in COVID 19 Morbidity and Mortality in Nepal. Kathmandu Univ Med J (KUMJ) 2020; 18:329-332. [PMID: 34165086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Background The global health community has emphasized the importance of reporting epidemiological data by age and sex groups in the COVID-19 pandemic. However, age and sex disaggregated data of COVID-19 cases and deaths are rarely reported. Such data are very crucial for public to make truly informed choices about their own diseases risk and also for governments for public policy response. Objective To assess age and gender difference among COVID-19 cases and deaths in Nepal. Method This is a retrospective study which uses public data on COVID-19 cases and deaths released by Ministry of Health and Population, Government of Nepal from January to November, 2020. The data analysis was carried out using SPPS software version 26. Result Nepal reported 233,452 confirmed cases and 1,566 deaths of COVID-19 from 23 January 2020 to 30 November 2020. We found statistically significant differences on COVID-19 cases by age and gender in Nepal with higher number of cases among males of economically active age groups (20-60 years). Similarly, we found significant difference in COVID-19 mortality with more death occurred among male group compared to female group and with highest number of deaths among the people of above 60 years. Furthermore, we found differences in cases and deaths among provinces. Conclusion The age and gender differences in COVID cases and deaths in Nepal indicates needs of considering age and sex groups seriously while planning for testing, case management and vaccination against COVID-19 infections in Nepal.
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Affiliation(s)
- M L Dhimal
- Global Institute for Interdisciplinary Studies, Kathmandu, Nepal
| | - N Rana
- Nepal Health Research Council, Ramshah Path, Kathmandu, Nepal
| | - B Aryal
- Nepal Health Research Council, Ramshah Path, Kathmandu, Nepal
| | - S K Adhikari
- Ministry of Health and Population, Ramshah Path, Kathmandu, Nepal
| | - R Shrestha
- Dhulikhel Hospital, Kathmandu University Hospital, Dhulikhel, Kavre, Nepal
| | - P Gyanwali
- Nepal Health Research Council, Ramshah Path, Kathmandu, Nepal
| | - M Dhimal
- Nepal Health Research Council, Ramshah Path, Kathmandu, Nepal
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Abstract
We study numerically the vortex-lattice formation in a rapidly rotating uniform quasi-two-dimensional Bose-Einstein condensate (BEC) in a box trap. We consider two types of boxes: square and circle. In a square-shaped 2D box trap, when the number of generated vortices is the square of an integer, the vortices are found to be arranged in a perfect square lattice, although deviations near the center are found when the number of generated vortices is arbitrary. In case of a circular box trap, the generated vortices in the rapidly rotating BEC lie on concentric closed orbits. Near the center, these orbits have the shape of polygons, whereas near the periphery the orbits are circles. The circular box trap is equivalent to the rotating cylindrical bucket used in early experiment(s) with liquid He II. The number of generated vortices in both cases is in qualitative agreement with Feynman's universal estimate. The numerical simulation for this study is performed by a solution of the underlying mean-field Gross-Pitaevskii (GP) equation in the rotating frame, where the wave function for the generated vortex lattice is a stationary state. Consequently, the imaginary-time propagation method can be used for a solution of the GP equation, known to lead to an accurate numerical solution. We also demonstrated the dynamical stability of the vortex lattices in real-time propagation upon a small change of the angular frequency of rotation, using the converged imaginary-time wave function as the initial state.
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Affiliation(s)
- S K Adhikari
- Instituto de Física Teórica, UNESP-Universidade Estadual Paulista, 01.140-070 São Paulo, São Paulo, Brazil
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Abstract
The formation of a regular lattice of quantized vortices in a fluid under rotation is a smoking-gun signature of its superfluid nature. Here we study the vortex lattice in a dilute superfluid gas of bosonic atoms at zero temperature along the crossover from the weak-coupling regime, where the inter-atomic scattering length is very small compared to the average distance between atoms, to the unitarity regime, where the inter-atomic scattering length diverges. This study is based on high-performance numerical simulations of the time-dependent nonlinear Schrödinger equation for the superfluid order parameter in three spatial dimensions, using a realistic analytical expression for the bulk equation of state of the system along the crossover from weak-coupling to unitarity. This equation of state has the correct weak-coupling and unitarity limits and faithfully reproduces the results of an accurate multi-orbital microscopic calculation. Our numerical predictions of the number of vortices and root-mean-square sizes are important benchmarks for future experiments.
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Affiliation(s)
- S K Adhikari
- Instituto de Física Teórica, UNESP - Universidade Estadual Paulista, 01.140-070 São Paulo, São Paulo, Brazil
| | - L Salasnich
- Dipartimento di Fisica e Astronomia "Galileo Galilei", Università di Padova, Via Marzolo 8, 35131, Padova, Italy. .,Istituto Nazionale di Ottica (INO) del Consiglio Nazionale delle Ricerche (CNR), Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy.
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Adhikari SK. Elastic collision and molecule formation of spatiotemporal light bullets in a cubic-quintic nonlinear medium. Phys Rev E 2016; 94:032217. [PMID: 27739812 DOI: 10.1103/physreve.94.032217] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Indexed: 06/06/2023]
Abstract
We consider the statics and dynamics of a stable, mobile three-dimensional (3D) spatiotemporal light bullet in a cubic-quintic nonlinear medium with a focusing cubic nonlinearity above a critical value and any defocusing quintic nonlinearity. The 3D light bullet can propagate with a constant velocity in any direction. Stability of the light bullet under a small perturbation is established numerically. We consider frontal collision between two light bullets with different relative velocities. At large velocities the collision is elastic with the bullets emerge after collision with practically no distortion. At small velocities two bullets coalesce to form a bullet molecule. At a small range of intermediate velocities the localized bullets could form a single entity which expands indefinitely, leading to a destruction of the bullets after collision. The present study is based on an analytic Lagrange variational approximation and a full numerical solution of the 3D nonlinear Schrödinger equation.
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Affiliation(s)
- S K Adhikari
- Instituto de Física Teórica, UNESP-Universidade Estadual Paulista, 01.140-070 São Paulo, São Paulo, Brazil
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Poudel R, Singh SK, Basnet S, Devkota H, Adhikari SK. Clinicopathological study of gall bladder cancer and its relationship with gall stones. J Soc Surg Nepal 2016. [DOI: 10.3126/jssn.v18i3.15308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Introduction: Gall bladder cancer is the most common cancer of the biliary tree and one of the highly malignant tumors with poor prognosis. Although its incidence is low in west, it is common in our part of the world. There are very few studies regarding gall bladder cancer in Nepal. The incidence of gallstones in patients with gall bladder cancer is high. The aim of the study was to evaluate the clinicopathological aspect of the disease in patients with gallbladder cancer and to Asses the incidence of gallstones in patients with gall bladder cancer.Material and Methods: This was a retrospective study carried out in GI Surgery unit of National Academy of Medical Science, Bir Hospital, Kathmandu, Nepal. All patients diagnosed as gallbladder carcinomas during 12 years period from 2002 to 2014 were included in this study. Their clinical characteristics, laboratory data, tumor histopathology reports were obtained and analyzed using SPSS17.Results: Total of 47 patients who met inclusion criteria were included in the study. Male to Female ratio was 1:1.8. Age ranged from 32 to 72 years with mean age of 54. Most common presenting symptom was Pain abdomen (93.6%) followed by weight loss (51.1%) and Jaundice (46.8%). Most common finding on examination was Icterus (42.6%) followed by palpable gall bladder (34%) and Hepatomegaly (29.8%). Gall Stones were seen in 37 (72.3%) patients. Most common histopathology was Adenocarcinoma (93.6%).Conclusion: Most of the patient with gall bladder cancer remained asymptomatic until late. Pain abdomen was most common presenting symptom and icterus was most common findings. There was strong association between gall bladder cancer and gallstones. There should be high index of suspicion if patient with gallstones has constant pain in right hypochondrium and has jaundice.
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Poudel R, Acharya A, Pokhrel S, Adhikari SK. Mucinous Cystic Borderline Tumor of the Mesentery: A Case Report. Kathmandu Univ Med J (KUMJ) 2015; 13:170-1. [PMID: 26643837 DOI: 10.3126/kumj.v13i2.16793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Mucinous cystic neoplasms are rare tumors of uncertain histogenesis. They arise from the ovaries, pancreas, and other intra-abdominal sites but more unusually from the mesentery. They can present with abdominal pain, distension, or a palpable mass but are commonly an incidental finding. We present a case of a 33-year-old female who presented with complain of pain abdomen for one-year duration. On Physical examination there was a palpable lump in right lumbar region extending to right iliac fossa. CT scan of abdomen and pelvis suggested the mass to be a Mesenteric Cyst. Enucleation of the cyst was done and histopathology report revealed Mucinous Cystic borderline tumor of the Mesentery.
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Affiliation(s)
- R Poudel
- Department of Surgery National Academy of Medical Science Bir Hospital, Kathmandu, Nepal
| | - A Acharya
- Department of Surgery National Academy of Medical Science Bir Hospital, Kathmandu, Nepal
| | - S Pokhrel
- Department of Surgery National Academy of Medical Science Bir Hospital, Kathmandu, Nepal
| | - S K Adhikari
- Department of Surgery National Academy of Medical Science Bir Hospital, Kathmandu, Nepal
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Adhikari SK. Stable spatial and spatiotemporal optical soliton in the core of an optical vortex. Phys Rev E Stat Nonlin Soft Matter Phys 2015; 92:042926. [PMID: 26565323 DOI: 10.1103/physreve.92.042926] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Indexed: 06/05/2023]
Abstract
We demonstrate a robust, stable, mobile, two-dimensional (2D) spatial and three-dimensional (3D) spatiotemporal optical soliton in the core of an optical vortex, while all nonlinearities are of the cubic (Kerr) type. The 3D soliton can propagate with a constant velocity along the vortex core without any deformation. Stability of the soliton under a small perturbation is established numerically. Two such solitons moving along the vortex core can undergo a quasielastic collision at medium velocities. Possibilities of forming such a 2D spatial soliton in the core of a vortical beam are discussed.
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Affiliation(s)
- S K Adhikari
- Instituto de Física Teórica, Universidade Estadual Paulista, 01.140-070 São Paulo, São Paulo, Brazil
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Dwivedi SN, Shukla RR, Singh R, Adhikari SK, Nambi KA, Purty SS, Roy GK. Determining the recharging capacity of an injection well in a semi-confined alluvial aquifer. CURR SCI INDIA 2015. [DOI: 10.18520/cs/v109/i6/1177-1181] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [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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Dwivedi SN, Shukla RR, Singh R, Adhikari SK, Nambi KA, Purty SS, Roy GK. Determining the recharging capacity of an injection well in a semi-confined alluvial aquifer. CURR SCI INDIA 2015. [DOI: 10.18520/v109/i6/1177-1181] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Abstract
INTRODUCTION Chronic dacryocystitis results in chronic infection and inflammation of the lacrimal sac. OBJECTIVE To identify the aetiology of chronic dacryocystitis and to determine their antimicrobial susceptibility pattern. MATERIALS AND METHODS A cross - sectional study was undertaken including 120 lacrimal swab materials collected from patients aged above 15 years suffering from chronic dacryocystitis. STATISTICS Data analysis was done by using software "Win pepi'' ver 7.9. RESULTS The bacteria of eight different species were isolated from 76.66 % (92/120) culture positive samples. 85.86 % showed a single and 14.13 % showed a mixed growth pattern. Coagulase negative staphylococci were the most common bacteria (P= 0.018) accounting for 33.96 % followed by Staphylococcus aureus (25.46 %), Streptococcus pneumoniae ( 19.81 % ), Streptococci viridans (5.66 %), Escherichia coli (5.66 %), Haemophilus spp ( 4.71 % ), Streptococcus pyogenes (3.77 %) and Bacillus spp (0.94 % ). Staphylococcus aureus were the most predominant bacteria in mixed growth. Rate of infection was higher in males 81.39 % than in females 74.02 %. Infection was higher in the age group of above 31 years. In the antimicrobial susceptibility test, except staphylococcus aureus, all the Gram positive isolates were 100 % sensitive to chloramphenicol and were least sensitive to tobramycin, but Gram negative isolates were equally sensitive to Chloramphenicol and Nalidixic acid. CONCLUSION Coagulase negative staphylococci are the most frequently isolated bacteria. Staphylococcus aureus is predominantly found in mixed growth. Chloramphenicol is the most effective drug of choice for chronic dacryocystitis.
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Affiliation(s)
- M Chaudhary
- B P Koirala Lion's Centre for Ophthalmic Studies, Kathmandu, Nepal
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Nitha B, De S, Adhikari SK, Devasagayam TPA, Janardhanan KK. Evaluation of free radical scavenging activity of morel mushroom, Morchella esculenta mycelia: a potential source of therapeutically useful antioxidants. Pharm Biol 2010; 48:453-460. [PMID: 20645726 DOI: 10.3109/13880200903170789] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Cellular damage caused by reactive oxygen species (ROS) has been implicated in several diseases and antioxidants are known to protect the body from this damage. Antioxidants thus, have gained significant importance in human health. The search for effective, non-toxic natural compounds with antioxidant activity has intensified in recent years. Mycelia of a number mushrooms have recently been successfully used for the development of novel pharmaceutical products. We examined the aqueous-ethanol extract of cultured mycelia of the morel mushroom, Morchella esculenta (L.) Pers. (Morchellaceae) for its ability to scavenge super oxide, hydroxyl, nitric oxide, 2,2'-diphenyl-1-picrylhydrazyl (DPPH), and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radicals as well as for inhibition of lipid peroxidation. The extract efficiently scavenged all these radicals and also inhibited lipid peroxidation. Ferric reducing antioxidant power (FRAP) assay indicated the hydrogen donating capacity of the extract. The pulse radiolysis studies using ABTS and carbonate radical (CO(3)(*-)) showed that the extract significantly carried out the decay of these radicals in a concentration-dependent manner. In conclusion, the investigation showed that the morel mushroom mycelium is an excellent source of antioxidants which are capable of imparting protection at different levels. The findings suggest the potential therapeutic use of morel mushroom, M. esculenta mycelia as an efficient antioxidant.
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Affiliation(s)
- B Nitha
- Department of Microbiology, Amala Cancer Research Centre, Thrissur, India
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Adhikari SK. Numerical study of the coupled time-dependent Gross-Pitaevskii equation: application to Bose-Einstein condensation. Phys Rev E Stat Nonlin Soft Matter Phys 2001; 63:056704. [PMID: 11415042 DOI: 10.1103/physreve.63.056704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2000] [Indexed: 05/23/2023]
Abstract
We present a numerical study of the coupled time-dependent Gross-Pitaevskii equation, which describes the Bose-Einstein condensate of several types of trapped bosons at ultralow temperature with both attractive and repulsive interatomic interactions. The same approach is used to study both stationary and time-evolution problems. We consider up to four types of atoms in the study of stationary problems. We consider the time-evolution problems where the frequencies of the traps or the atomic scattering lengths are suddenly changed in a stable preformed condensate. We also study the effect of periodically varying these frequencies or scattering lengths on a preformed condensate. These changes introduce oscillations in the condensate, which are studied in detail. Good convergence is obtained in all cases studied.
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Affiliation(s)
- S K Adhikari
- Instituto de Física Teórica, Universidade Estadual Paulista, 01.405-900 São Paulo, São Paulo, Brazil
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Adhikari SK. Numerical study of the spherically symmetric gross-pitaevskii equation in two space dimensions. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 2000; 62:2937-2944. [PMID: 11088777 DOI: 10.1103/physreve.62.2937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2000] [Indexed: 05/23/2023]
Abstract
We present a numerical study of the time-dependent and time-independent Gross-Pitaevskii (GP) equation in two space dimensions, which describes the Bose-Einstein condensate of trapped bosons at ultralow temperature with both attractive and repulsive interatomic interactions. Both time-dependent and time-independent GP equations are used to study the stationary problems. In addition the time-dependent approach is used to study some evolution problems of the condensate. Specifically, we study the evolution problem where the trap energy is suddenly changed in a stable preformed condensate. In this case the system oscillates with increasing amplitude and does not remain limited between two stable configurations. Good convergence is obtained in all cases studied.
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Affiliation(s)
- SK Adhikari
- Instituto de Fisica Teorica, Universidade Estadual Paulista, 01. 405-900 Sao Paulo, Sao Paulo, Brazil
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Stosic BD, Gomes MA, Adhikari SK. Quantum tunneling fragmentation model. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 2000; 61:6111-9. [PMID: 11088284 DOI: 10.1103/physreve.61.6111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/1999] [Revised: 01/03/2000] [Indexed: 04/15/2023]
Abstract
A nonthermal quantum mechanical statistical fragmentation model based on tunneling of particles through potential barriers is studied in compact two- and three-dimensional systems. It is shown that this fragmentation dynamics gives origin to several static and dynamic scaling relations. The critical exponents are found and compared with those obtained in classical statistical models of fragmentation of general interest, in particular with thermal fragmentation involving classical processes over potential barriers. Besides its general theoretical interest, the fragmentation dynamics discussed here is complementary to classical fragmentation dynamics of interest in chemical kinetics and can be useful in the study of a number of other dynamic processes such as nuclear fragmentation.
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Affiliation(s)
- BD Stosic
- Departamento de Fisica, Universidade Federal de Pernambuco, 50670-901 Recife-PE, Brazil
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Adhikari SK, Tomio L. Relativistic effect on low-energy nucleon-deuteron scattering. Phys Rev C Nucl Phys 1995; 51:70-77. [PMID: 9970039 DOI: 10.1103/physrevc.51.70] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Adhikari SK, de Araujo CF, Frederico T. Theoretical prevision for the low-energy 3S1-3D1 mixing parameters. Phys Rev C Nucl Phys 1994; 50:R2684-R2686. [PMID: 9970034 DOI: 10.1103/physrevc.50.r2684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Adhikari SK, Frederico T, Goldman ID, Sharma SS. Model for asymptotic D-state parameters of light nuclei: Application to 4He. Phys Rev C Nucl Phys 1994; 50:822-830. [PMID: 9969725 DOI: 10.1103/physrevc.50.822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Adhikari SK, Tomio L, Frederico T. Relativistic three-particle scattering equations. Phys Rev C Nucl Phys 1993; 48:2105-2107. [PMID: 9969059 DOI: 10.1103/physrevc.48.2105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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27
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Adhikari SK, Delfino A, Frederico T, Tomio L. Model independence of scattering of three identical bosons in two dimensions. Phys Rev A 1993; 47:1093-1100. [PMID: 9909032 DOI: 10.1103/physreva.47.1093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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28
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Delfino A, Adhikari SK, Tomio L, Frederico T. Unusually strong attraction in the presence of continuum bound state. Phys Rev C Nucl Phys 1992; 46:1612-1616. [PMID: 9968280 DOI: 10.1103/physrevc.46.1612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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29
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Delfino A, Adhikari SK, Tomio L, Frederico T. Three-body collapse for Tabakin potentials and the Thomas effect. Phys Rev C Nucl Phys 1992; 46:471-476. [PMID: 9968140 DOI: 10.1103/physrevc.46.471] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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31
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Adhikari SK, Frederico T. Analytical model for the triton asymptotic D-state parameters. Phys Rev C Nucl Phys 1990; 42:128-137. [PMID: 9966694 DOI: 10.1103/physrevc.42.128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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33
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Adhikari SK, Gomes MA, Pessoa LF. Wentzel-Kramers-Brillouin-type approximations for bound states in short-range nonsingular potentials. Phys Rev C Nucl Phys 1989; 40:2276-2281. [PMID: 9966227 DOI: 10.1103/physrevc.40.2276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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34
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Adhikari SK, Kowalski KL. Universality of off-shell two-body scattering amplitudes at negative and positive energies: Gamma -matrix formalism. Phys Rev A Gen Phys 1989; 40:2270-2275. [PMID: 9902400 DOI: 10.1103/physreva.40.2270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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35
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Adhikari SK, Hussein MS. Sum rule approach to the study of statistical decay properties of nuclear giant resonances. Phys Rev C Nucl Phys 1988; 37:2332-2333. [PMID: 9954714 DOI: 10.1103/physrevc.37.2332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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36
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Adhikari SK, Delfino A, Frederico T, Goldman ID, Tomio L. Efimov and Thomas effects and the model dependence of three-particle observables in two and three dimensions. Phys Rev A Gen Phys 1988; 37:3666-3673. [PMID: 9899475 DOI: 10.1103/physreva.37.3666] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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37
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Adhikari SK, Das TK. Effect of polarization potential in proton-deuteron scattering. Phys Rev C Nucl Phys 1988; 37:1376-1378. [PMID: 9954588 DOI: 10.1103/physrevc.37.1376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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38
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Frederico T, Goldman ID, Adhikari SK. Possibility of new information about the N-N force in N-d polarization observables. Phys Rev C Nucl Phys 1988; 37:949-953. [PMID: 9954527 DOI: 10.1103/physrevc.37.949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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39
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Frederico T, Adhikari SK, Hussein MS. Estimate of the triton asymptotic D to S ratio. Phys Rev C Nucl Phys 1988; 37:364-369. [PMID: 9954446 DOI: 10.1103/physrevc.37.364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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41
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Adhikari SK, Tomio L. Unified formulation of variational approaches and separable expansions for the solution of scattering equations. Phys Rev C Nucl Phys 1987; 36:1275-1285. [PMID: 9954215 DOI: 10.1103/physrevc.36.1275] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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42
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Tomio L, Delfino A, Adhikari SK. Trinucleon system in a two-body model: Coulomb effect on bound and scattering states. Phys Rev C Nucl Phys 1987; 35:441-447. [PMID: 9953788 DOI: 10.1103/physrevc.35.441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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44
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Gerjuoy E, Adhikari SK. Lippmann-Schwinger equation in a soluble three-body model: Surface integrals at infinity. Phys Rev C Nucl Phys 1987; 35:415-429. [PMID: 9953786 DOI: 10.1103/physrevc.35.415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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45
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46
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Dias H, Hussein MS, Adhikari SK. Decay properties of giant multipole resonances: Collective doorways and statistical doorways. Phys Rev Lett 1986; 57:1998-2001. [PMID: 10033606 DOI: 10.1103/physrevlett.57.1998] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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47
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Gerjuoy E, Adhikari SK. Alternative interpretations of the many-particle Lippmann-Schwinger equation. Phys Rev C Nucl Phys 1986; 34:1-13. [PMID: 9953419 DOI: 10.1103/physrevc.34.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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48
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Adhikari SK. Exit doorways and intermediate structure resonances. Phys Rev C Nucl Phys 1986; 33:471-480. [PMID: 9953170 DOI: 10.1103/physrevc.33.471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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49
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Adhikari SK, Tomio L. Iteration-subtraction method for scattering equations compared with continued fractions method. Phys Rev C Nucl Phys 1986; 33:467-470. [PMID: 9953169 DOI: 10.1103/physrevc.33.467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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50
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Gerjuoy E, Adhikari SK. Nonuniqueness of solutions to the Lippmann-Schwinger equation in a soluble three-body model. Phys Rev A Gen Phys 1985; 31:2005-2019. [PMID: 9895728 DOI: 10.1103/physreva.31.2005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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