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Ansari R, Aghdasi P, Shahnazari A. DFT-based finite element analysis of compressive response in armchair phosphorene nanotubes. J Mol Graph Model 2024; 129:108751. [PMID: 38430695 DOI: 10.1016/j.jmgm.2024.108751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 02/13/2024] [Accepted: 02/25/2024] [Indexed: 03/05/2024]
Abstract
In this paper, the finite element method is utilized to evaluate the behavior of the armchair phosphorene nanotubes under the compressive loading. The energy equations of the molecular and structural mechanics are used to obtain the elemental properties. The critical compressive forces of various armchair phosphorene nanotubes are computed with clamped-clamped and clamped-free boundary conditions. Results show that the stability of armchair phosphorene nanotubes increases with increasing nanotube aspect ratio, particularly under clamped-clamped boundary conditions. Finally, the buckling mode shapes of armchair phosphorene nanotubes under different boundary conditions are compared. Our work offers valuable insights into how these nanotubes respond to mechanical stress, helps determine elemental properties, and investigates the effects of nanotube geometry and different boundary conditions on their stability. This knowledge has broad applications in fields like nanotechnology, materials science, and nanomechanics, advancing the understanding of nanoscale materials and their potential for various practical uses.
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Affiliation(s)
- R Ansari
- Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran.
| | - P Aghdasi
- Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran; Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 2H5, Canada.
| | - A Shahnazari
- Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran
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2
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Mirnezhad M, Ansari R, Falahatgar SR, Aghdasi P. Analyzing fine scaling quantum effects on the buckling of axially-loaded carbon nanotubes based on the density functional theory and molecular mechanics method. Sci Rep 2024; 14:7435. [PMID: 38548779 PMCID: PMC10978868 DOI: 10.1038/s41598-024-55701-6] [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: 12/15/2023] [Accepted: 02/27/2024] [Indexed: 04/01/2024] Open
Abstract
In this paper, the quantum effects of fine scaling on the buckling behavior of carbon nanotubes (CNTs) under axial loading are investigated. Molecular mechanics and quantum mechanics are respectively utilized to study the buckling behavior and to obtain the molecular mechanics coefficients of fine-scale nanotubes. The results of buckling behavior of CNTs with different chiralities with finite and infinite dimensions are given, and a comparison study is presented on them. The differences between finite and infinite nanotubes reflect the quantum effects of fine scaling on the buckling behavior. In addition, the results show that the dimensional changes highly affect the mechanical properties and the buckling behavior of CNTs to certain dimensions. Moreover, dimensional changes have a significant effect on the critical buckling strain. Beside, in addition to the structure dimensions, the arrangement of structural and boundary atoms have a major influence on the buckling behavior.
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Affiliation(s)
- M Mirnezhad
- Faculty of Mechanical Engineering, University Campus 2, University of Guilan, Rasht, Iran
| | - R Ansari
- Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran.
| | - S R Falahatgar
- Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran
| | - P Aghdasi
- Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran.
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 2H5, Canada.
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Nickabadi S, Ansari R, Golmohammadi B, Aghdasi P. Vibrational analysis of double-walled silicon carbide nano-cones: a finite element investigation. Sci Rep 2024; 14:5114. [PMID: 38429395 PMCID: PMC10907353 DOI: 10.1038/s41598-024-55536-1] [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: 09/24/2023] [Accepted: 02/24/2024] [Indexed: 03/03/2024] Open
Abstract
A three-dimensional finite element model is used to investigate the vibrational properties of double-walled silicon carbide nano-cones with various dimensions. The dependence of the vibrational properties of double-walled silicon carbide nano-cones on their length, apex angles and boundary conditions are evaluated. Current model consists a combination of beam and spring elements that simulates the interatomic interactions of bonding and nonbonding. The Lennard-Jones potential is employed to model the interactions between two non-bonding atoms. The fundamental frequency and mode shape of the double-walled silicon carbide nano-cones are calculated.
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Affiliation(s)
- S Nickabadi
- Faculty of Mechanical Engineering, University of Imam Khomeini Marine Sciences, Nowshahr, Iran
| | - R Ansari
- Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran
| | - B Golmohammadi
- Department of Physical Chemistry, Faculty Chemistry, University of Tabriz, Tabriz, Iran.
| | - P Aghdasi
- Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran
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4
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Eghbalian M, Ansari R, Haghighi S. Molecular dynamics investigation of the mechanical properties and fracture behaviour of hydroxyl-functionalised carbon and silicon carbide nanotubes-reinforced polymer nanocomposites. Molecular Simulation 2023. [DOI: 10.1080/08927022.2022.2164022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- M. Eghbalian
- Faculty of Mechanical Engineering, University of Guilan, Rasht, Iran
| | - R. Ansari
- Faculty of Mechanical Engineering, University of Guilan, Rasht, Iran
| | - S. Haghighi
- Faculty of Mechanical Engineering, University of Guilan, Rasht, Iran
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Ajori S, Ameri A, Ansari R. High velocity impact analysis of free-free carbon nanotubes. J Mol Graph Model 2021; 111:108105. [PMID: 34896882 DOI: 10.1016/j.jmgm.2021.108105] [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: 05/30/2021] [Revised: 12/02/2021] [Accepted: 12/06/2021] [Indexed: 10/19/2022]
Abstract
In the present work, molecular dynamics (MD) simulations are used to investigate the impact behavior of single-walled carbon nanotubes (SWCNTs) with free boundary conditions in two directions, i.e. vertical and horizontal. To consider the effect of consecutive impacts, the number of carbon nanotubes (CNTs) participated in simulations is chosen from two to five in a row. MD results show that adding the number of impacts increases the magnitude of energy loss in both mentioned directions and reduces the maximum impact force in horizontal cases. In addition, by increasing the velocity of striker CNT from 1 km/s to the maximum value which causes any fracture, the effect of initial velocity on the impact properties and also the ultimate initial velocity for each model are investigated. It is demonstrated that the energy loss and the maximum value of impact force increase as the initial velocity of the striker increases. Also, it is found that the impact strength in the vertical direction is higher than that of the horizontal one, while the horizontal CNTs perform better in the absorption of impact energy. Moreover, for all models, the fracture mechanism of CNTs resulting from the impact process is represented and the procedure of failure is explained.
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Affiliation(s)
- S Ajori
- Department of Mechanical Engineering, Faculty of Engineering, University of Maragheh, P.O. Box 55136-553, Maragheh, Iran.
| | - A Ameri
- Department of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran
| | - R Ansari
- Department of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran.
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Eghbalian M, Ansari R, Haghighi S. On the mechanical properties and fracture analysis of polymer nanocomposites reinforced by functionalized silicon carbide nanotubes: A molecular dynamics investigation. J Mol Graph Model 2021; 111:108086. [PMID: 34861609 DOI: 10.1016/j.jmgm.2021.108086] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/17/2021] [Accepted: 11/18/2021] [Indexed: 11/25/2022]
Abstract
The mechanical characteristics of reinforced polymer nanocomposites with Hydrogen (H)- and Fluorine (F)-functionalized silicon carbide nanotubes (H-and F-fSiCNTs) are investigated herein using molecular dynamics (MD) simulations. The effects of covalent functionalization and chirality of SiCNT, and diverse polymer materials on Young's modulus, maximum stress, and strain to the failure point, as well as strain energy are studied. The results reveal that by increasing the functionalization degree, the maximum stress, maximum strain, elastic modulus, and strain energy decrease. The tensile strength of polymer nanocomposites containing SiCNT is higher than that of pure polymer and polymers containing functionalized silicon carbide nanotubes (fSiCNTs). It is also found that the incorporation of fSiCNT into the polymer matrix (fSiCNT/polymer) gives rise to a considerable improvement in the ultimate strength of nanocomposites compared to the pure polymer. Polymer nanocomposites reinforced by armchair SiCNTs and fSiCNTs withstand higher maximum stresses and possess less longitudinal Young's modulus as compared to the same systems comprising zigzag nanotubes. In every percent of functionalization, the zigzag F-fSiCNT/polymer tends to have a higher Young's modulus as compared to the zigzag H-fSiCNT/polymer. Similarly, the armchair F-fSiCNTs incorporated into the polyethylene (PE) matrix (F-fSiCNTs/PE) are stiffer than the armchair H-fSiCNTs/PE in each weight of functionalization. Moreover, the armchair fSiCNTs/polymer nanocomposites show higher storage of strain energy in comparison with their zigzag counterparts.
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Affiliation(s)
- M Eghbalian
- Faculty of Mechanical Engineering, University Campus 2, University of Guilan, Rasht, Iran
| | - R Ansari
- Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran.
| | - S Haghighi
- Faculty of Mechanical Engineering, University Campus 2, University of Guilan, Rasht, Iran
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Ansari R, Faraji Oskouie M, Nesarhosseini S, Rouhi H. Nonlinear Thermally Induced Vibration Analysis of Porous FGM Timoshenko Beams Embedded in an Elastic Medium. Transp Porous Media 2021. [DOI: 10.1007/s11242-021-01714-y] [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: 11/28/2022]
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Ajori S, Haghighi S, Parsapour H, Ansari R. Fundamental frequency analysis of endohedrally functionalized carbon nanotubes with metallic nanowires: a molecular dynamics study. J Mol Model 2021; 27:313. [PMID: 34611775 DOI: 10.1007/s00894-021-04933-8] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 09/21/2021] [Indexed: 10/20/2022]
Abstract
The endohedral functionalization of carbon nanotubes (CNTs) with nanowires (NWs), i.e., NWs@CNTs, has been the center of attention in a lot of research due to the applications of NWs@CNTs in nanoelectronic devices, heterogeneous catalysis, and electromagnetic wave absorption. To this end, based on the classical molecular dynamics (MD) simulations, the effect of four pentagonal structures of encapsulated metallic nanowires (mNWs), namely the eclipsed pentagon (E), the deformed staggered pentagon (Ds), staggered pentagon (S), and staggered pentagonal structure without the monatomic chain passing through the centers of the parallel pentagons (R) configurations on the vibrational behavior of CNTs, is investigated. Also, the effects of geometrical parameters such as length and radius of CNTs on the natural frequencies of simulated models are explored. The results illustrate that by increasing the length, the natural frequency of pure CNTs and mNWs@CNTs decreases. In a similar length, mNWs@CNTs possess lower natural frequencies compared to the pure CNTs. According to the results, the highest and lowest natural frequencies are calculated by inserting the S structure of sodium NW and Ds structure of aluminum NW inside their proper armchair CNT, i.e., Na-S NW@ (9,9) CNT and Al-Ds NW@ (7,7) CNT, respectively.
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Affiliation(s)
- S Ajori
- Department of Mechanical Engineering, Faculty of Engineering, University of Maragheh, P.O. Box 55136-553, Maragheh, Iran.
| | - S Haghighi
- Department of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran
| | - H Parsapour
- Department of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran
| | - R Ansari
- Department of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran.
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10
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Nickabadi S, Ansari R, Rouhi S, Aghdasi P. On the derivation of coefficient of Morse potential function for the silicene: a DFT investigation. J Mol Model 2021; 27:190. [PMID: 34050437 DOI: 10.1007/s00894-021-04780-7] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 04/28/2021] [Indexed: 11/26/2022]
Abstract
In this paper, the structural and mechanical properties of silicene are investigated by the density functional theory calculations. To calculate Young's, bulk, and shear moduli and Poisson's ratio of the silicene, the optimized unit cells containing two atoms are proposed and the effect of chirality on the elastic properties of silicene is examined. It is shown that the silicene has an isotropic behavior, while graphene has an anisotropic behavior. The results showed that calculated moduli for the silicene are significantly lower than those of graphene in zigzag and armchair directions, while Poisson's ratio of silicene is higher than that of graphene. The paper describes one common type of inharmonic interatomic potentials used for constructing nonlinear models of the material using the modified Morse potential function. Using this concept, the effects of chirality on dissociation energy, inflection point, and coefficients of the modified Morse potential function are studied. Comparison of the cutoff distance value in the modified Morse potential showed that inflection point values for the armchair and zigzag graphene are highly direction-dependent, whereas these values have negligible difference for silicene.
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Affiliation(s)
- S Nickabadi
- Faculty of Mechanical Engineering, University Campus 2, University of Guilan, Rasht, Iran
| | - R Ansari
- Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran.
| | - S Rouhi
- Young Researchers and Elite Club, Langarud Branch, Islamic Azad University, Langarud, Guilan, Iran
| | - P Aghdasi
- Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran
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11
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Dastmard M, Ansari R, Rouhi S. Mechanical properties of group IV single-walled nanotubes: a finite element approach based on the density functional theory. J Mol Model 2021; 27:163. [PMID: 33970328 DOI: 10.1007/s00894-021-04776-3] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 04/21/2021] [Indexed: 10/21/2022]
Abstract
In this article, the density functional theory is applied to characterize the mechanical properties of single-walled nanotubes of group IV of the periodic table. These materials include carbon nanotube, silicon nanotube, germanium nanotube, and stanene nanotube. (10,10) armchair nanotube is selected for the investigation. By establishing a link between potential energy expressions in molecular and structural mechanics, a finite element approach is proposed for modeling nanotubes. In the proposed model, the nanotubes are considered as an assemblage of beam elements. Young's modulus of the nanotubes is computed by the proposed finite element model. Young's modulus of carbon, silicon, germanium, and tin nanotubes are obtained as 1029, 159.82, 83.23, and 83.15 GPa, respectively, using the density functional theory. Also, the finite element approach gives the values as 1090, 154.67, 85.2, and 82.6 GPa, respectively. It is shown that the finite element model can predict the results of the density functional theory with good accuracy.
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Affiliation(s)
- M Dastmard
- Faculty of Mechanical Engineering, University Campus 2, University of Guilan, Rasht, Iran
| | - R Ansari
- Faculty of Mechanical Engineering, University Campus 2, University of Guilan, Rasht, Iran. .,Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran.
| | - S Rouhi
- Department of Mechanical Engineering, Langarud Branch, Islamic Azad University, Langarud, Iran
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12
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Boroushak SH, Ajori S, Ansari R. Thermal conductivity of perfect and defective carbon nanotubes functionalized with carbene: a molecular dynamics study. Molecular Simulation 2021. [DOI: 10.1080/08927022.2021.1873322] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- S. H. Boroushak
- Department of Mechanical Engineering, University of Guilan, Rasht, Iran
| | - S. Ajori
- Department of Mechanical Engineering, Faculty of Engineering, University of Maragheh, Maragheh, Iran
| | - R. Ansari
- Department of Mechanical Engineering, University of Guilan, Rasht, Iran
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Aghdasi P, Ansari R, Rouhi S, Yousefi S. A DFT-based finite element approach for studying elastic properties, buckling and vibration of the arsenene. J Mol Graph Model 2020; 101:107725. [PMID: 32911118 DOI: 10.1016/j.jmgm.2020.107725] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [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: 07/03/2020] [Revised: 08/19/2020] [Accepted: 08/21/2020] [Indexed: 02/08/2023]
Abstract
A finite element model is developed to modeli the arsenene nanosheet. To obtain the element properties, which are used to represent As-As bonds in the structure of the arsenene, first principle calculation is used. The developed model is then used to compute Young's modulus, critical compressive force and the fundamental frequency of the arsenene nanosheet with different geometrical parameters. It is seen that the employed finite element model can be efficiently used to predict surface Young's modulus of the arsenene. Furthermore, larger arsenene nanosheets have larger surface Young's modulus. In the next step, the critical compressive forces of the arsenene nanosheet under different boundary conditions are computed. It is seen that the influence of the boundary conditions has higher impact on the bunking force of the smaller arsenenes nanosheets. Finally, investigating the vibrational characteristics of the arsenene nanosheets revealed that increasing the horizontal side length at a constant vertical side length leads to a reduction in the fundamental natural frequency.
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Affiliation(s)
- P Aghdasi
- Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran
| | - R Ansari
- Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran.
| | - S Rouhi
- Department of Mechanical Engineering, Langroud Branch, Islamic Azad University, Langroud, Iran
| | - Sh Yousefi
- Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran
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14
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Ajori S, Parsapour H, Ansari R. A molecular dynamics study on the buckling behavior of single-walled carbon nanotubes filled with gold nanowires. J Mol Model 2020; 26:196. [PMID: 32621021 DOI: 10.1007/s00894-020-04454-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Accepted: 06/21/2020] [Indexed: 11/27/2022]
Abstract
Molecular dynamics (MD) simulations are carried out to study the buckling of pure gold nanowires (GNWs) and hybrid GNWs@single-walled carbon nanotubes (SWCNTs). The effects of geometrical parameters and endohedral filling of SWCNTs on the critical buckling force are taken into consideration. Two different types of GNWs, namely multi-shell and pentagonal GNWs, with various structures are considered. The results illustrate that the buckling force of the pure GNWs is less than those of the pure SWCNTs and hybrid structures. Also, GNWs possess higher buckling forces by increasing their cross-section area. It is observed that enclosing the GNWs by SWCNTs improves the mechanical behaviors of both CNTs and GNWs. In hybrid multi-shell GNWs@SWCNTs, by increasing the radius, the effect of encapsulation on the buckling force is more remarkable. It can be seen that the encapsulation of pentagonal GNWs has a slightly more effect on the buckling behavior than the encapsulation of multi-shell GNWs. Moreover, it is found out that by increasing the length, the buckling force decreases.
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Affiliation(s)
- S Ajori
- Department of Mechanical Engineering, Faculty of Engineering, University of Maragheh, P.O. Box 55136-553, Maragheh, Iran.
| | - H Parsapour
- Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran
| | - R Ansari
- Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran.
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Heidari F, Karimi E, Firouzifar M, Khamushian P, Ansari R, Mohammadi Ardehali M, Heidari F. Anosmia as a prominent symptom of COVID-19 infection. Rhinology 2020; 58:302-303. [PMID: 32319971 DOI: 10.4193/rhin20.140] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
According to WHO recommendations, everyone must protect themselves against Coronavirus disease 2019 (COVID-19), which will also protect others. Due to the lack of current effective treatment and vaccine for COVID-19, screening, rapid diagnosis and isolation of the patients are essential (1, 2). Therefore, identifying the early symptoms of COVID-19 is of particular importance and is a health system priority. Early studies from COVID-19 outbreak in China have illustrated several non-specific signs and symptoms in infected patients, including fever, dry cough, dyspnea, myalgia, fatigue, lymphopenia, and radiographic evidence of pneumonia (3, 4). Recently, a probability of association between COVID-19 and altered olfactory function has been reported in South Korea, Iran, Italy, France, UK and the United States (5-8). However, to our knowledge, the definite association between COVID-19 and anosmia has not been published.
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Affiliation(s)
- F Heidari
- Otorhinolaryngology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - E Karimi
- Otorhinolaryngology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - M Firouzifar
- Otorhinolaryngology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - P Khamushian
- Internal Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - R Ansari
- Otorhinolaryngology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - M Mohammadi Ardehali
- Otorhinolaryngology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - F Heidari
- Otorhinolaryngology Research Center, Tehran University of Medical Sciences, Tehran, Iran
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Abideen Z, Koyro HW, Huchzermeyer B, Ansari R, Zulfiqar F, Gul B. Ameliorating effects of biochar on photosynthetic efficiency and antioxidant defence of Phragmites karka under drought stress. Plant Biol (Stuttg) 2020; 22:259-266. [PMID: 31618504 DOI: 10.1111/plb.13054] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [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: 08/02/2019] [Accepted: 09/27/2019] [Indexed: 05/21/2023]
Abstract
Biochar (BC) has been reported to improve growth and drought resistance in many plants. However, adequate information on the drought resistance mechanism mediated of BC on Phragmites karka, a bioenergy plant, is not available. The impact of BC addition (0%, 0.75% and 2.5%) on plant growth and physiology of P. karka under drought was assessed. Soil water-holding capacity and soil water content were significantly improved with 0.75% BC as compared with the un-amended controls. This resulted in improved plant performance under drought conditions. An increase of parameters, such as plant fresh and dry biomass, root to shoot ratio and root mass fraction, was paralleled by an increase of chlorophyll content, net photosynthesis rate and water use efficiency of plants. Plants treated with 0.75% BC experienced less oxidative stress due to higher photosystem II efficiency and stimulated activity of antioxidant defense systems. Our results demonstrate that soil amendment with 0.75% BC allow the potential energy plant P. karka to grow in an arid habitat.
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Affiliation(s)
- Z Abideen
- Dr. Muhammad Ajmal Khan Institute of Sustainable Halophyte Utilization, University of Karachi, Karachi, Pakistan
- Institute of Plant Ecology, Justus-Liebig-University Giessen, Giessen, Germany
- Institute of Botany, Gottfried Wilhelm Leibniz University, Herrenhäuser, Hannover, Germany
| | - H-W Koyro
- Institute of Plant Ecology, Justus-Liebig-University Giessen, Giessen, Germany
| | - B Huchzermeyer
- Institute of Botany, Gottfried Wilhelm Leibniz University, Herrenhäuser, Hannover, Germany
| | - R Ansari
- Dr. Muhammad Ajmal Khan Institute of Sustainable Halophyte Utilization, University of Karachi, Karachi, Pakistan
| | - F Zulfiqar
- Institute of Horticultural Sciences, University of Agriculture, Faisalabad, Pakistan
| | - B Gul
- Dr. Muhammad Ajmal Khan Institute of Sustainable Halophyte Utilization, University of Karachi, Karachi, Pakistan
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Ajori S, Ameri A, Ansari R. Adsorption analysis and mechanical characteristics of carbon nanotubes under physisorption of biological molecules in an aqueous environment using molecular dynamics simulations. Molecular Simulation 2020. [DOI: 10.1080/08927022.2020.1712380] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- S. Ajori
- Faculty of Engineering, Department of Mechanical Engineering, University of Maragheh, Maragheh, Iran
| | - A. Ameri
- Faculty of Mechanical Engineering, University of Guilan, Rasht, Iran
| | - R. Ansari
- Faculty of Mechanical Engineering, University of Guilan, Rasht, Iran
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18
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Ajori S, Haghighi S, Ansari R. Tensile characteristics of carbene-functionalized CNTs subjected to physisorption of polymer chains: a molecular dynamics study. J Mol Model 2019; 25:318. [PMID: 31598779 DOI: 10.1007/s00894-019-4189-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 08/27/2019] [Indexed: 11/30/2022]
Abstract
Tensile properties such as Young's modulus and ultimate tensile force are important properties in understanding the characteristics of nanocomposites. Besides, the importance of functionalization methods in modification of the unique mechanical and elastic properties of carbon nanotubes (CNTs) is being widely recognized. In this paper, the tensile properties of CNTs functionalized with carbene under physisorption of polymer chains, i.e., aramid and polyketone chains, are investigated by using a series of molecular dynamics (MD) simulations. The results illustrated that Young's modulus of carbene-functionalized CNTs (cfCNTs) decreases by rising the weight percentage of carbene. By contrast, Young's modulus of cfCNTs under physisorption of polymer chains (cfCNTs/polymers) increases as the carbene weight rises. In a particular carbene weight, Young's modulus of cfCNTs/polymers decreases by increasing the chains of non-covalent functional groups. Moreover, it is shown that similar to Young's modulus, ultimate tensile force of cfCNTs reduces by increasing the weight percentage of carbene whereas the ultimate tensile force of cfCNTs/polymers has an increasing trend with raising the carbene weight.
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Affiliation(s)
- S Ajori
- Department of Mechanical Engineering, Faculty of Engineering, University of Maragheh, P.O. Box 55136-553, Maragheh, Iran
| | - S Haghighi
- Faculty of Mechanical Engineering, University Campus2, University of Guilan, Rasht, Iran
| | - R Ansari
- Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran.
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Ansari R, Soni G, Ojha P, Aglave V, Barvalia P. Gas geyser syndrome: Preventable emerging toxic encephalopathy in developing countries. J Neurol Sci 2019. [DOI: 10.1016/j.jns.2019.10.1083] [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: 11/27/2022]
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Aglave V, Ojha P, Jagiasi K, Soni G, Singh R, Barvalia P, Ansari R. Clinical spectrum of Myelin Oligodendrocyte Glycoprotein (MOG) antibody associated CNS demyelination. J Neurol Sci 2019. [DOI: 10.1016/j.jns.2019.10.271] [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: 11/17/2022]
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21
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Ojha P, Aglave V, Jagiasi K, Soni G, Singh R, Ansari R, Barvalia P. Unusual strokes? Think of unusual etiology ! J Neurol Sci 2019. [DOI: 10.1016/j.jns.2019.10.696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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22
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Aglave V, Ojha P, Ansari R, Barvalia P. A case of clippers with spinal cord presentation. J Neurol Sci 2019. [DOI: 10.1016/j.jns.2019.10.1080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Haghighi S, Ansari R, Ajori S. Interfacial properties of 3D metallic carbon nanostructures (T6 and T14)-reinforced polymer nanocomposites: A molecular dynamics study. J Mol Graph Model 2019; 92:341-356. [PMID: 31446204 DOI: 10.1016/j.jmgm.2019.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 08/14/2019] [Accepted: 08/14/2019] [Indexed: 11/25/2022]
Abstract
Herein, the interfacial properties of new three-dimensional (3D) configurations of metallic carbon, namely T6 and T14, incorporated to different polymer matrices (T6 and T14@polymers) are studied using molecular dynamics (MD) simulations. The effects of two types of shape models for T6 and T14, i.e. beam- and plate-like models, various square cross-sectional areas for the reinforcements, pull-out velocity and polymer structure on the interaction energy and pull-out force of final system are investigated. The results reveal that the interfacial resistance of the system is improved by imposing a high pull-out velocity to the nanofillers. For each pull-out velocity, the effect of beam-like T6 and T14@polycarbonate (beam-like T6 and T14@PC) on increasing average pull-out force is more remarkable than that of similar models surrounded by polypropylene (PP). The beam- and plate-like structures@polymers possess the lowest and highest interfacial resistance, respectively. As the aspect ratio (length-to-width ratio) of nanofillers changes from the lowest value to the highest one, the average pull-out force decreases. The average pull-out force of plate-like T6@polymers is higher than their plate-like T14 counterparts. Besides, higher absolute values of interaction energy in plate-like T6 and T14@polymers in comparison with others imply that the load-carrying capacity from the surrounding matrix to the plate-like nanofillers is significantly increased.
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Affiliation(s)
- S Haghighi
- Department of Mechanical Engineering, University Campus2, University of Guilan, Rasht, Iran
| | - R Ansari
- Faculty of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran.
| | - S Ajori
- Department of Mechanical Engineering, Faculty of Engineering, University of Maragheh, P.O. Box 55136-553, Maragheh, Iran
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Haghighi S, Ansari R, Ajori S. Influence of polyethylene cross-linked functionalization on the interfacial properties of carbon nanotube-reinforced polymer nanocomposites: a molecular dynamics study. J Mol Model 2019; 25:105. [PMID: 30927080 DOI: 10.1007/s00894-019-3983-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 03/05/2019] [Indexed: 11/29/2022]
Affiliation(s)
- S Haghighi
- Department of Mechanical Engineering, University of Guilan, University Campus2, Rasht, Iran
| | - R Ansari
- Department of Mechanical Engineering, University of Guilan, PO Box 3756, Rasht, Iran.
| | - S Ajori
- Department of Mechanical Engineering, University of Maragheh, Maragheh, East Azerbaijan Province, Iran
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Ajori S, Ameri A, Ansari R. On the mechanical stability and buckling analysis of carbon nanotubes filled with ice nanotubes in the aqueous environment: A molecular dynamics simulation approach. J Mol Graph Model 2019; 89:74-81. [PMID: 30870651 DOI: 10.1016/j.jmgm.2019.03.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 02/26/2019] [Accepted: 03/01/2019] [Indexed: 10/27/2022]
Abstract
In this article, molecular dynamics (MD) simulations are utilized to investigate the buckling behavior of carbon nanotubes (CNTs) containing ice nanotubes in the vacuum and aqueous environment. The obtained results show that unlike the critical strain, the critical buckling load of CNT containing ice nanotube is higher than that of pure CNT in the vacuum. It is also indicated that the sensitivity of critical buckling load and the critical strain of CNT containing ice nanotube to the variation of length decreases when the nanostructure is subjected to the aqueous environment. Additionally, it is observed that the calculated critical buckling load and the critical strain of CNTs filled with ice nanotubes in the aqueous environment are respectively larger and smaller than those obtained in the vacuum. It is further observed that CNTs lose their symmetric buckling mode shape as they are filled with ice nanotubes in the vacuum. The results of these simulations can be used as a benchmark for further studies in designing novel potential applications such as proton electronic-based nanoelectromechanical systems (NEMS).
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Affiliation(s)
- S Ajori
- Department of Mechanical Engineering, University of Maragheh, Maragheh, East Azerbaijan Province, Iran.
| | - A Ameri
- Department of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran
| | - R Ansari
- Department of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran.
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Beaver C, Behan F, Ansari R, Pooley R, Wilkinson P, Jackson D, Harper S, Iorio F, Yusa K, Garnett M. PO-327 Whole-genome CRISPR-CAS9 screening: the wellcome sanger institute cellular generation and phenotyping pipeline. ESMO Open 2018. [DOI: 10.1136/esmoopen-2018-eacr25.357] [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: 11/03/2022] Open
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Allen A, Ansari R, Thurley J, Murphy L, Chan E, McKinnon C, Fitzgerald R, Deeley A, Wachter R, Rajewski J. Adult ADHD and the use of mindfulness-based practice: A pilot study. Eur Psychiatry 2017. [DOI: 10.1016/j.eurpsy.2017.01.937] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Educational objectivesThe goal of this poster is to discuss a brief pilot study in which mindfulness – and yoga-based practices were utilized with a group of adult ADHD patients.MethodsA sample of 10 adults participated in a pilot group which utilized the use mindfulness-based and yoga practices to address ADHD. This group was a single 2 hour session which was a pilot for a future 6-week psycho-educational group. The participants completed the following questionnaires: the Cognitive and Affective Mindfulness Scale (CAMS-R), the Freiburg mindfulness inventory and the Mindful Attention Awareness Scale (MAAS) in addition to a survey regarding levels of knowledge of yoga and mindfulness prior to the beginning of the session. The participants completed a survey at the end of the session.ResultsIn our small sample group, all respondents reported that they found the session helpful (43% strongly agreed; 57% agreed). When asked if the participants were likely to explore and learn more about ADHD and meditation on their own based on what they learned in the session, most indicated that they were likely to (43% strongly agreed; 43% agreed and 14% were neutral).ConclusionsThe use of treatment modalities involving the use of meditation and mindfulness-based techniques in a group setting are thought to be helpful in addressing some of the target symptoms of ADHD. Based on the preliminary data collected in our small pilot study, our group intends to further explore the efficacy of meditation-based groups in the form of a 6-week training program in 2017.Disclosure of interestThe authors have not supplied their declaration of competing interest.
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Asadollahi A, Sohrabnezhad S, Ansari R. Enhancement of photocatalytic activity and stability of Ag2CO3 by formation of AgBr/Ag2CO3 heterojunction in mordenite zeolite. ADV POWDER TECHNOL 2017. [DOI: 10.1016/j.apt.2016.10.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Ajori S, Ansari R, Parsapour H. Buckling analysis of defective cross-linked functionalized single- and double-walled carbon nanotubes with polyethylene chains using molecular dynamics simulations. J Mol Model 2016; 22:298. [PMID: 27900580 DOI: 10.1007/s00894-016-3157-z] [Citation(s) in RCA: 3] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Accepted: 11/08/2016] [Indexed: 11/26/2022]
Abstract
Functionalized carbon nanotubes (CNTs) can be used for improving the mechanical properties and load transfer in nanocomposites. In this research, the buckling behavior of perfect and defective cross-linked functionalized CNTs with polyethylene (PE) chains is studied employing molecular dynamics (MD) simulations. Two different configurations with the consideration of vacancy defects, namely mapped and wrapped, are selected. According to the results, critical buckling force of cross-linked functionalized CNTs with PE chains increases as compared to pure CNTs, especially in the case of double-walled carbon nanotubes (DWCNTs). By contrast, it is demonstrated that critical strain of cross-linked functionalized CNTs decreases as compared to that of pristine CNTs. Also, it is observed that increasing the weight percentage leads to the higher increase and the decrease in critical buckling force and strain of cross-linked functionalized CNTs, respectively. Moreover, the presence of defect considerably reduces both critical buckling force and strain of cross-linked functionalized CNTs. Finally, it is shown that the critical buckling strain is more sensitive to the presence of defects as compared to critical buckling force.
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Affiliation(s)
- S Ajori
- Department of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran.
| | - R Ansari
- Department of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran.
| | - H Parsapour
- Department of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran
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Ansari R. Pharmacy performance measures submitted by URAC accredited specialty pharmacies in 2015. Res Social Adm Pharm 2016. [DOI: 10.1016/j.sapharm.2016.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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31
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Kelishadi R, Sadry G, Zadegan N, Hashemipour M, Sabet B, Bashardoust N, Ansari R, Alikhassy H. Smoking, Adolescents and Health: Isfahan Healthy Heart Programme-Heart Health Promotion from Childhood. Asia Pac J Public Health 2016; 16:15-22. [DOI: 10.1177/101053950401600104] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To evaluate the effect of some environmental factors on smoking, and to assess some health hazards of smoking in adolescents, this cross-sectional study was performed among 1950 students, ages11-18, selected by multi-stage random sampling from three cities in Iran. According to self-administered questionnaires, 12.9% of boys and 4% of girls reported to be smoker (OR=3.34, 95%CI: 2.33, 4.77, p<0.001). The mean values of total-and LDL-cholesterol were higher in smokers and their HDL-C was lower than non-smokers (163.33± 33.83, 90.73± 31 and 46.7± 12.24 vs.156± 29.53, 85±26.5 and 49.4±13.7 mg/dl, respectively, p<0.05). The mean systolic and diastolic blood pressures were higher in smokers than non-smokers (110.7± 14.5, 67.6± 11.55 vs. 104.9± 14.3, 63.2± 10.8 mmHg, respectively, p<0.05). The smokers had higher BMI than non-smokers (20.34 ±3.84 vs.19.55 ± 3.66, p<0.05). The mean food consumption frequency was lower for fruits and vegetables and higher for fat/salty snacks and fast foods in smokers than non-smokers. Logistic regression analysis showed significant association between sex, age, the number of family members and number of smokers in the family and smoking in students. The findings of this study have implications for future tobacco prevention strategies through community-based interventions. Asia Pac JPublic Health 2004; 16(1): 15-22.
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Affiliation(s)
- R. Kelishadi
- Preventive Paediatric Cardiology Department, Isfahan
Cardiovascular Research Centre, Isfahan University of Medical Sciences,
| | - G. Sadry
- Health Services, Isfahan University of Medical Sciences, Isfahan Provincial Health Office
| | - N.S. Zadegan
- Isfahan Cardiovascular Research Centre, Isfahan University
of Medical Sciences
| | - M. Hashemipour
- Paediatric Endocrinology Department, Isfahan University
of Medical Sciences
| | - B. Sabet
- Surveillance Unit, Isfahan Cardiovascular Research Centre,
Isfahan University of Medical Sciences
| | | | - R. Ansari
- Preventive Paediatric Cardiology Department, Isfahan
Cardiovascular Research Centre, Isfahan University of Medical Sciences
| | - H. Alikhassy
- Nutrition Department, Isfahan Cardiovascular Research
Centre, Isfahan University of Medical Sciences
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Rouhi S, Alizadeh Y, Ansari R. On the elastic properties of single-walled carbon nanotubes/poly(ethylene oxide) nanocomposites using molecular dynamics simulations. J Mol Model 2016; 22:41. [PMID: 26791535 DOI: 10.1007/s00894-015-2889-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [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: 10/13/2014] [Accepted: 12/10/2015] [Indexed: 10/22/2022]
Abstract
Molecular dynamics simulations are used to study the physical and mechanical properties of single-walled carbon nanotubes/poly(ethylene oxide) nanocomposites. The effects of nanotube atomic structure, diameter, and volume fraction on the polymer density distribution, polymer atom distribution, stress-strain curves of nanocomposites and Young's, and shear moduli of single-walled carbon nanotubes/poly(ethylene oxide) nanocomposites are explored. It is shown that the density of polymer, surrounding the nanotube surface, has a peak near the nanotube surface. However, increasing distance leads to dropping it to the value near the density of pure polymer. It is seen that for armchair nanotubes, the average polymer atoms distances from the single-walled carbon nanotubes are larger than the polymer atom distance from zigzag nanotubes. It further is shown that zigzag nanotubes are better candidates to reinforce poly (ethylene oxide) than their armchair counterparts.
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Affiliation(s)
- S Rouhi
- Young Researchers and Elite Club, Langroud Branch, Islamic Azad University, Langroud, Guilan, Iran
| | - Y Alizadeh
- Mechanical Engineering Department, Amirkabir University of Technology, Tehran, Iran.
| | - R Ansari
- Mechanical Engineering Department, University of Guilan, P.O. Box 3756, Rasht, Iran
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Ansari R, Ajori S, Ameri A. Elastic and structural properties and buckling behavior of single-walled carbon nanotubes under chemical adsorption of atomic oxygen and hydroxyl. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2014.10.036] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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34
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Arvand M, Ansari R, Heydari L. The behavior of polyaniline-coated PVC membrane based on 7,16-didecyl-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane for ph measurements in highly acidic media. J Anal Chem 2014. [DOI: 10.1134/s1061934814090020] [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: 11/23/2022]
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35
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Hochster HS, Grothey A, Hart L, Rowland K, Ansari R, Alberts S, Chowhan N, Ramanathan RK, Keaton M, Hainsworth JD, Childs BH. Improved time to treatment failure with an intermittent oxaliplatin strategy: results of CONcePT. Ann Oncol 2014; 25:1172-8. [PMID: 24608198 DOI: 10.1093/annonc/mdu107] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Oxaliplatin is an integral component of colorectal cancer treatment, but its use is limited by neurotoxicity. The Combined Oxaliplatin Neurotoxicity Prevention Trial (CONcePT) tested intermittent oxaliplatin (IO) administration and the use of concurrent calcium and magnesium salts (Ca/Mg), two modifications intended to reduce neurotoxicity and extend the duration of treatment. PATIENTS AND METHODS In this trial involving double randomization, 140 patients were randomized to receive modified FOLFOX7 plus bevacizumab with IO (eight-cycle blocks of oxaliplatin treatment) versus continuous oxaliplatin (CO); and Ca/Mg versus placebo (pre- and postoxaliplatin infusion). The primary end point was time-to-treatment failure (TTF). RESULTS One hundred thirty-nine patients were entered and treated up to the point of early study termination due to concerns by the data-monitoring committee (DMC) that Ca/Mg adversely affected tumor response. Tumor response was not a study end point. Given DMC concerns, an additional independent, blinded radiology review of all images showed no adverse effect of treatment schedule or Ca/Mg on response by Response Evaluation Criteria In Solid Tumors. The IO schedule was superior to CO [hazard ratio (HR) = 0.581, P = 0.0026] for both TTF and time-to-tumor progression (TTP) (HR = 0.533, P = 0.047). CONCLUSIONS An IO dosing schedule had a significant benefit on both TTF and TTP versus CO dosing in this trial despite the very attenuated sample. There was no effect of Ca/Mg on response.
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Affiliation(s)
- H S Hochster
- Yale Cancer Center, Yale School of Medicine, New Haven
| | - A Grothey
- Department of Medical Oncology, Mayo Clinic Rochester, Rochester
| | - L Hart
- Drug Development Program, Florida Cancer Specialists, Ft. Myers
| | - K Rowland
- Cancer center, Carle Cancer Center, Urbana
| | - R Ansari
- Department of Medical Oncology, Michiana Hematology Oncology, South Bend
| | - S Alberts
- Division of Medical Oncology, Mayo Clinic, Rochester
| | - N Chowhan
- Department of Medical Oncology, Floyd Memorial Cancer Center of Indiana, New Albany
| | - R K Ramanathan
- Clinical Trials Program, Scottsdale Healthcare Research Institute at The Virginia B. Piper Cancer Center, Scottsdale
| | - M Keaton
- Department of Hematology and Oncology, Augusta Oncology Associates, Augusta
| | - J D Hainsworth
- Department of Oncology, Sarah Cannon Research Institute, Nashville
| | - B H Childs
- Department of Oncology, Sanofi US, Bridgewater, USA
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Ansari R, Malakpour S, Faghihnasiri M, Ajori S. Characterization of the Mechanical Properties of Monolayer Molybdenum Disulfide Nanosheets Using First Principles. J Nanotechnol Eng Med 2014. [DOI: 10.1115/1.4026207] [Citation(s) in RCA: 5] [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: 11/08/2022]
Abstract
Recently, synthesized inorganic two-dimensional monolayer nanostructures are very promising to be applied in electronic devices. This article explores the mechanical properties of a monolayer molybdenum disulfide (MoS2) including Young's bulk and shear moduli and Poisson's ratio by applying density functional theory (DFT) calculation based on the generalized gradient approximation (GGA). The results demonstrate that the elastic properties of MoS2 nanosheets are less than those of graphene and hexagonal boron-nitride (h-BN) nanosheets. However, their Poisson's ratio is found to be higher than that of graphene and h-BN nanosheet. It is also observed that due to the special structure of MoS2, the thickness of nanosheet changes when the axial strain is applied.
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Affiliation(s)
- R. Ansari
- Department of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran e-mail:
| | - S. Malakpour
- Department of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran
| | - M. Faghihnasiri
- Department of Physics, University of Guilan, P.O. Box 1914, Rasht, Iran
| | - S. Ajori
- Department of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran
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Affiliation(s)
- S Moossavi
- Digestive Oncology Research Center, Digestive Disease Research Institute, Tehran University of Medical Sciences , Tehran, Iran
| | - R Ansari
- Digestive Oncology Research Center, Digestive Disease Research Institute, Tehran University of Medical Sciences , Tehran, Iran
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38
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Affiliation(s)
- B. Motevalli
- Dept. of Mechanical Engineering, Univ. of Guilan, P.O. Box 3756, Rasht, Iran
| | - R. Ansari
- Dept. of Mechanical Engineering, Univ. of Guilan, P.O. Box 3756, Rasht, Iran (corresponding author)
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Almasalha F, Xu D, Keenan GM, Khokhar A, Yao Y, Chen YC, Johnson A, Ansari R, Wilkie DJ. Data mining nursing care plans of end-of-life patients: a study to improve healthcare decision making. Int J Nurs Knowl 2012; 24:15-24. [PMID: 23413930 DOI: 10.1111/j.2047-3095.2012.01217.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
PURPOSE To reveal hidden patterns and knowledge present in nursing care information documented with standardized nursing terminologies on end-of-life (EOL) hospitalized patients. METHOD 596 episodes of care that included pain as a problem on a patient's care plan were examined using statistical and data mining tools. The data were extracted from the Hands-On Automated Nursing Data System database of nursing care plan episodes (n = 40,747) coded with NANDA-I, Nursing Outcomes Classification, and Nursing Intervention Classification (NNN) terminologies. System episode data (episode = care plans updated at every hand-off on a patient while staying on a hospital unit) had been previously gathered in eight units located in four different healthcare facilities (total episodes = 40,747; EOL episodes = 1,425) over 2 years and anonymized prior to this analyses. RESULTS Results show multiple discoveries, including EOL patients with hospital stays (<72 hr) are less likely (p < .005) to meet the pain relief goals compared with EOL patients with longer hospital stays. CONCLUSIONS The study demonstrates some major benefits of systematically integrating NNN into electronic health records.
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Ansari R, Kazemi E, Mahmoudinezhad E, Sadeghi F. Preferred Position and Orientation of Anticancer Drug Cisplatin During Encapsulation Into Single-Walled Carbon Nanotubes. J Nanotechnol Eng Med 2012. [DOI: 10.1115/1.4006916] [Citation(s) in RCA: 4] [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] [Indexed: 12/20/2022]
Abstract
Cisplatin is one of the most widely prescribed chemotherapy drugs to treat different types of cancers. However, this anticancer drug has a number of side effects such as kidney and nerve damages, anaphylactic reactions, hearing loss, nausea, and vomiting that strongly restrict its function. In the present study, single-walled carbon nanotubes (SWCNTs) are used as protective drug carriers which can decrease these severe side effects to some extent. Using the hybrid discrete-continuum model in conjunction with Lennard-Jones potential, new semi-analytical expressions in terms of single integrals are given to evaluate van der Waals (vdW) potential energy and interaction force between an offset cisplatin and a SWCNT. In addition, molecular dynamics (MD) simulations are conducted to validate the results of such a hybrid approach. The preferred location and orientation of cisplatin while entering SWCNTs are determined. It is shown that the equilibrium condition of the drug may be affected by the radius of nanotube, the orientation of cisplatin, and the distance between the central molecule of the drug (Pt) and the left end of nanotube. Furthermore, the influence of equilibrium condition on the distributions of vdW interactions is investigated.
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Affiliation(s)
- R. Ansari
- Department of Mechanical Engineering, University of Guilan,P.O. Box 3756, Rasht, Iran
| | - E. Kazemi
- Department of Mechanical Engineering, University of Guilan,P.O. Box 3756, Rasht, Iran
| | - E. Mahmoudinezhad
- Department of Mechanical Engineering, University of Guilan,P.O. Box 3756, Rasht, Iran
| | - F. Sadeghi
- Department of Mechanical Engineering, University of Guilan,P.O. Box 3756, Rasht, Iran
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Abstract
On the basis of the continuum approximation along with Lennard–Jones potential function, new semi-analytical expressions are presented to evaluate the van der Waals interactions between an ellipsoidal fullerene and a semi-infinite single-walled carbon nanotube. Using direct method, these expressions are also extended to model ellipsoidal carbon onions inside multiwalled carbon nanotubes. In addition, acceptance and suction energies which are two noticeable issues for medical applications such as drug delivery are determined. Neglecting the frictional effects and by imposing some simplifying assumptions on the van der Waals interaction force, a simple formula is given to evaluate the oscillation frequency of ellipsoidal carbon onions inside multiwalled carbon nanotubes. Also, the effects of the number of tube shells and ellipsoidal carbon onion shells on the oscillatory behavior are examined. It is shown that there exists an optimal value for the number of tube shells beyond which the oscillation frequency remains unchanged.
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Affiliation(s)
- F. Sadeghi
- Department of Mechanical Engineering,University of Guilan, P.O. Box 3756, Rasht, Iran
| | - R. Ansari
- Department of Mechanical Engineering,University of Guilan, P.O. Box 3756, Rasht, Iran
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Abstract
There are many new nanomechanical devices created based on carbon nanostructures among which gigahertz oscillators have generated considerable interest to many researchers. In the present paper, the oscillatory behavior of ellipsoidal fullerenes inside single-walled carbon nanotubes is studied comprehensively. Utilizing the continuum approximation along with Lennard–Jones potential, new semi-analytical expressions are presented to evaluate the potential energy and van der Waals interaction force of such systems. Neglecting the frictional effects, the equation of motion is directly solved on the basis of the actual force distribution between the interacting molecules. In addition, a semi-analytical expression is given to determine the oscillation frequency into which the influence of initial conditions is incorporated. Based on the newly derived expression, a thorough study on the various aspects of operating frequencies under different system variables such as geometrical parameters and initial conditions is conducted. Based on the present study, some new aspects of such nano-oscillators have been disclosed.
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Affiliation(s)
| | - F. Sadeghi
- Department of Mechanical Engineering,University of Guilan, P.O. Box 3756, Rasht, Iran
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Alisafaei F, Ansari R, Rouhi H. Continuum Modeling of van der Waals Interaction Force Between Carbon Nanocones and Carbon Nanotubes. J Nanotechnol Eng Med 2012. [DOI: 10.1115/1.4005485] [Citation(s) in RCA: 12] [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: 11/08/2022]
Abstract
Using the Lennard–Jones potential, continuum modeling of the van der Waals potential energy and interaction force distributions are investigated for the eccentric and concentric single-walled carbon nanocones inside the single-walled carbon nanotubes. Furthermore, a new semi-analytical solution is presented to evaluate the van der Waals interaction of the nanocone located on the axis of the nanotube. Eccentric and concentric configurations of these nanostructures are also investigated to obtain the preferred position of the nanocone inside the nanotubes. Finally, the optimum radius of a carbon nanotube for which the preferred location of carbon nanocones is along the tube axis is found.
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Affiliation(s)
- F. Alisafaei
- Department of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht 3756, Iran
| | - R. Ansari
- Department of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht 3756, Iran
| | - H. Rouhi
- Department of Mechanical Engineering, University of Guilan, P.O. Box 3756, Rasht 3756, Iran
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Jalal SI, Riggs HD, Melnyk A, Richards D, Agarwala A, Neubauer M, Ansari R, Govindan R, Bruetman D, Fisher W, Breen T, Johnson CS, Yu M, Einhorn L, Hanna N. Updated survival and outcomes for older adults with inoperable stage III non-small-cell lung cancer treated with cisplatin, etoposide, and concurrent chest radiation with or without consolidation docetaxel: analysis of a phase III trial from the Hoosier Oncology Group (HOG) and US Oncology. Ann Oncol 2011; 23:1730-8. [PMID: 22156624 DOI: 10.1093/annonc/mdr565] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Concurrent chemoradiation with etoposide and cisplatin (EP/XRT) is standard treatment for inoperable stage III locally advanced non-small-cell lung cancer (LA-NSCLC). Consolidation docetaxel (D; Taxotere) after EP/XRT resulted in increased toxicity but no improvement in survival compared with observation (O). We report updated survival for the entire study population and include an analysis of efficacy and tolerability of EP/XRT with or without D in patients aged ≥ 70 years. PATIENTS AND METHODS Hoosier Oncology Group LUN 01-24 enrolled 243 patients with LA-NSCLC and randomized 166 after EP/XRT to three cycles of D versus O. the trial was terminated after an analysis of the first 203 patients demonstrated futility of D. RESULTS Median survival time (MST) for the overall study population was 21.5 months, and 3-, 4-, and 5-year survival rates were 30.7%, 18.0%, and 13.9%, respectively. No differences in MST or 3-year survival were noted between D and O arms. Older patients had similar MST (17.1 versus 22.8 months for younger patients, P = 0.15) but higher rates of grade 3/4 toxicity and hospitalization during induction. CONCLUSIONS Consolidation docetaxel after EP/XRT does not improve survival in LA-NSCLC. Fit older adults with LA-NSCLC benefit from concurrent chemoradiation similarly as younger patients but experience higher rates of hospitalization and toxicity.
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Affiliation(s)
- S I Jalal
- Division of Hematology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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Ansari R, Gholami R, Hosseini K, Sahmani S. A sixth-order compact finite difference method for vibrational analysis of nanobeams embedded in an elastic medium based on nonlocal beam theory. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.mcm.2011.06.030] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Vahedi H, Ansari R, Mir-Nasseri MM, Jafari E. Irritable bowel syndrome: a review article. Middle East J Dig Dis 2010; 2:66-77. [PMID: 25197516 PMCID: PMC4154827] [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] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Accepted: 08/25/2010] [Indexed: 11/13/2022] Open
Abstract
Irritable bowel syndrome (IBS) is the most prevalent functional gastrointestinal disorder noted in the general population worldwide. Its chronic nature, signs and symptoms which vary periodically from mild to severe have many negative effects on the quality of life for the sufferer; therefore the appropriate treatment of these patients is highly important. Patients should be informed by their doctors that the nature of the disease is benign, and educated on how to deal with and control symptoms of the disease. This article sets out a review of recent studies on the prevalence of IBS in Iran and appropriate methods for management of patients affected by IBS.
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Affiliation(s)
- H Vahedi
- 1Digestive Disease Research Center, Tehran University of Medical Sciences, Shariati Hospital, Tehran, Iran
| | - R Ansari
- 1Digestive Disease Research Center, Tehran University of Medical Sciences, Shariati Hospital, Tehran, Iran
| | - MM Mir-Nasseri
- 1Digestive Disease Research Center, Tehran University of Medical Sciences, Shariati Hospital, Tehran, Iran
| | - E Jafari
- 1Digestive Disease Research Center, Tehran University of Medical Sciences, Shariati Hospital, Tehran, Iran
,Corresponding Author: Elham Jafari MD, MPH Digestive Disease Research Center, Tehran University of Medical Sciences, Shariati Hospital, Tehran 14117, Iran Tel: +98 21 82415173 Fax: +98 21 82415400
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Ansari R, Mosayebzadeh Z. Removal of basic dye methylene blue from aqueous solutions using sawdust and sawdust coated with polypyrrole. JICS 2010. [DOI: 10.1007/bf03246019] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Treat JA, Gonin R, Socinski MA, Edelman MJ, Catalano RB, Marinucci DM, Ansari R, Gillenwater HH, Rowland KM, Comis RL, Obasaju CK, Belani CP. A randomized, phase III multicenter trial of gemcitabine in combination with carboplatin or paclitaxel versus paclitaxel plus carboplatin in patients with advanced or metastatic non-small-cell lung cancer. Ann Oncol 2009; 21:540-547. [PMID: 19833819 DOI: 10.1093/annonc/mdp352] [Citation(s) in RCA: 45] [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: 01/09/2023] Open
Abstract
BACKGROUND Paclitaxel-carboplatin is used as the standard regimen for patients with advanced or metastatic non-small-cell lung cancer (NSCLC). This trial was designed to compare gemcitabine + carboplatin or gemcitabine + paclitaxel to the standard regimen. PATIENTS AND METHODS A total of 1135 chemonaive patients with stage IIIB or IV NSCLC were randomly allocated to receive gemcitabine 1000 mg/m(2) on days 1 and 8 plus carboplatin area under the concentration-time curve (AUC) 5.5 on day 1 (GC), gemcitabine 1000 mg/m(2) on days 1 and 8 plus paclitaxel 200 mg/m(2) on day 1 (GP), or paclitaxel 225 mg/m(2) plus carboplatin AUC 6.0 on day 1 (PC). Stratification was based on disease stage, baseline weight loss, and presence or absence of brain metastases. Cycles were repeated every 21 days for up to six cycles or disease progression. RESULTS Median survival (months) with GC was 7.9 compared with 8.5 for GP and 8.7 for PC. Response rates (RRs) were as follows: GC, 25.3%; GP, 32.1%; and PC, 29.8%. The GC arm was associated with a greater incidence of grade 3 or 4 hematologic events but a lower rate of neurotoxicity and alopecia when compared with GP and PC. CONCLUSIONS Non-platinum and non-paclitaxel gemcitabine-containing doublets demonstrate similar overall survival and RR compared with the standard PC regimen. However, the treatment arms had distinct toxicity profiles.
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Affiliation(s)
- J A Treat
- US Medical Division, Lilly USA, Indianapolis, IN.
| | | | - M A Socinski
- Division of Hematology/Oncology, Multidisciplinary Thoracic Oncology Group, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC
| | - M J Edelman
- Division of Hematology/Oncology, University of Maryland Greenbaum Cancer Center, Baltimore, MD
| | - R B Catalano
- Drexel University College of Medicine, Philadelphia, PA
| | - D M Marinucci
- Drexel University College of Medicine, Philadelphia, PA
| | - R Ansari
- Northern Indiana Cancer Research Consortium, South Bend, IN
| | - H H Gillenwater
- Department of Hematology/Oncology, University of Virginia Cancer Center, Charlottesville, VA
| | - K M Rowland
- Department of Medicine, Carle Clinic Cancer Center, Urbana, IL
| | - R L Comis
- Drexel University College of Medicine, Philadelphia, PA
| | - C K Obasaju
- US Medical Division, Lilly USA, Indianapolis, IN
| | - C P Belani
- Division of Hematology/Oncology, Penn State Hershey Cancer Institute, Hershey, PA, USA
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