Objective.This study explores the feasibility of a stationary gantry cardiac gated computed tomography (CT) with carbon nanotube (CNT) linear x-ray source arrays.Approach.We developed a stationary gantry CT system utilizing multipixel CNT x-ray sources. Given the advantages of straightforward x-ray pulse control with these sources, we investigated the potential for gated prospective imaging. We implemented prospective respiratory and cardiac gating control and evaluated the system through dynamic phantom imaging studies followed by imaging of a porcine model.Main Results.The findings revealed minimal anatomical motion artifacts in the heart and lungs, confirming successful physiologic gated acquisition in stationary gantry cardiac CT. This indicates the potential of this imaging approach for reducing artifacts and improving image quality.Significance.This study demonstrates the feasibility of prospective physiological gating with CNT x-ray sources in a stationary gantry setup for cardiac imaging. This approach could potentially alleviate the need for beta blocker administration during cardiac CT scans, thereby increasing the flexibility of the imaging system and enabling the imaging of a wider variety of patient cardiac conditions.

Faster and predictable osseointegration is crucial for the success of dental implants, especially in patients with compromised local or systemic conditions. Despite various surface modifications on the commercially available Titanium (Ti) dental implants, the bioactivity of Ti is still low. Thus, to achieve both biological and therapeutic activity on titanium surfaces, surface modification techniques such as titanium nanotubes have been studied as nanotube surfaces can hold therapeutic drugs and molecules. The main aim of the present research work is to study the early osseointegration around the novel Simvastatin drug eluting nanotubular dental implant. In the present research, the titanium nanotubes were fabricated on the screw-shaped dental implant surface and the Simvastatin drug was loaded into the nanotubes using the ultrasonication dip method. In vitro and In vivo studies were carried out on the modified dental implants. In vitro cell culture study reported enhanced osteogenic activity on the drug-loaded nanotube surface implants. The invivo animal studies were evaluated by micro-CT, histopathology, and reverse torque removal analysis methods. The test results showed faster osseointegration with the strong interface on the Simvastatin drug-loaded implant surface at 4 weeks of healing as compared to the control implants.

Herein we have made a comparative study of the efficiency of three different nanotubes viz. Carbon nanotube (CNT), boron nitride nanotube (BNNT) and silicon carbide nanotube (SiCNT) to deliver the cancerous drug, Azacitidine (AZD). The atomistic description of the encapsulation process of AZD in these nanotubes has been analyzed by evaluating parameters like adsorption energy, electrostatic potential map, reduced density gradient (RDG). Higher adsorption energy of AZD with BNNT (-0.66eV), SiCNT (-0.92eV) compared to CNT (-0.56eV) confirms stronger binding affinity of the drug for the former than the later. Charge density and electrostatic potential map suggest that charge separation involving BNNT and CNT is more prominent than SiCNT. Evaluation of different thermodynamic parameters like Gibbs free energy, enthalpy change revealed that the overall encapsulation process is spontaneous and exothermic in nature and much favorable with BNNT and SiCNT. Stabilizing interactions of the drug with BNNT and SiCNT has been confirmed from RDG analysis. ADMP molecular dynamics simulation supports that the encapsulation process of the drug within the NT at room temperature. These results open up unlimited opportunities for the applications of these NTs as a drug delivery system in the field of nanomedicine.

A group of aromatic compounds (benzene, naphthalene, anthracene, and tetracene) was selected to design four sheets of graphene based on quantum mechanics calculations using the density function theory (DFT), leaning on the cyclic polymerization mechanism. Theoretical results offer that graphene-I is the most stable depending on the values of EHOMO (- 4.91601 eV), gap energy (2.76549 eV), and total energy (- 3447.42377654 a.u.). The thermodynamic theoretical outcome showed that all reactions are exothermic and spontaneous. Graphene is a two-dimensional plane, so the nanotube design process is with two possibilities: the first about the x-axis (horizontal (H)) and the second about the y-axis (vertical (V)). The theoretical results gave two groups: the first gave more stability to graphene at the expense of the nanotubes prepared from it, namely, graphene-I and the second gave less stability to graphene compared to the nanotubes prepared from it, namely, graphene-II, graphene-III, and graphene-IV), depending on the energy of HOMO and gap energy. The value of gap energy ranged (from 1.10370 to 1.79922 eV) for the following compounds (graphene-II, nanotube-II-V, nanotube-III-H, and nanotube-IV-V), making those important compounds in solar cells. These theoretical results showed the possibility of preparing graphene and then nanotubes from aromatic compounds, giving the benefit of doubling the preparation of new compounds with important applications and at the same time eliminating aromatic compounds harmful to the environment.

Based on density functional theory, we theoretically investigate the electronic structures of free-standing armchair Janus MoSSe nanoribbons (A-MoSSeNR) with width up to 25.5 nm. The equilibrium structures of nanoribbons with spontaneous curling are obtained by energy minimization in molecular dynamics (MD). The curvature is 0.178 nm-1 regardless of nanoribbon width. Both finite element method and analytical solution based on continuum theory provide qualitatively consistent results for the curling behavior, reflecting that relaxation of intrinsic strain induced by the atomic asymmetry acts as the driving force. The non-edge bandgap of curled A-MoSSeNR reduces faster with the increase of width compared with planar nanoribbons. It can be observed that the real-space wave function at the non-edge VBM is localized in the central region of the curled nanoribbon. When the curvature is larger than 1.0 nm-1, both edge bandgap and non-edge bandgap shrink with the further increase of curvature. Moreover, we explore the spontaneous curling and consequent sewing process of nanoribbon to form nanotube (Z-MoSSeNT) by MD simulations. The spontaneously formed Z-MoSSeNT with 5.6 nm radius possesses the lowest energy. When radius is smaller than 0.9 nm, the bandgap of Z-MoSSeNT drops rapidly as the radius decreases. We expect the theoretical results can help build the foundation for novel nanoscale devices based on Janus TMD nanoribbons.

Understanding the effect of copper oxide (CuO)-decorated zinc oxide nanotube on carbon monoxide (CO) adsorption is crucial for designing a high-performance CO gas sensor. In this work, CO sensing properties of copper oxide-decorated zinc oxide (CuO-ZnO) nanotube are studied theoretically by employing first-principles density functional theory for the first time. The stability, adsorption mechanism, density of states, and change in electrical conductivity are studied. The results of calculating the adsorption energy show strong chemical adsorption of CO on CuO-ZnO nanotubes. The adsorption energy of CO on CuO-ZnO nanotube is calculated as 7.5 times higher than that on ZnO nanotube. The results of the Mulliken charge analysis reveal that electron transfer occurs from CO molecules to CuO-ZnO nanotubes. Additionally, the electrical conductivity of CuO-ZnO nanotubes significantly changes after adsorption of CO at room temperature. According to these studies, CuO-ZnO nanotube sensors can be used for the detection of CO gas. The results are in excellent agreement with the reported experimental results.

We report a Monte-Carlo simulation of the formation of skyrmions under a rotary magnetic field on a nanotube. The zero-field magnetic state is characterized as helical stripe domains swirling on the nanotube, with one to three periods depending on the ratio of Dzyaloshinskii-Moriya to ferromagnetic interaction and tubular size. Under a rotary magnetic field, the formation of skyrmions is in pair and the skyrmion number can be tuned. The movement of skyrmions is neither synchronous along with the rotary field, nor along a helical trajectory perpendicular to the rotary field. It is ascribed to that within a skyrmion pair, on one hand, the coupling between skyrmions is nonnegligible; on the other hand, different skyrmion pairs side by side are decoupled. This work predicts a way of nanotube-based skyrmion manipulation, and might develop the rotary information storage on energy- and space-saving modes or an edgeless racetrack memory.

Background: One of the underlying mechanisms of Parkinson\'s disease is the aggregation of α-synuclein proteins, including amyloids and Lewy bodies in the brain. Aim: To study the inhibitory effect of doped carbon nanotubes (CNTs) on amyloid aggregation. Materials & methods: Molecular dynamics tools were utilized to simulate the influence of CNTs doped with phosphorus, nitrogen and bromine and nitrogen on the formation of α-synuclein amyloid. Results: The CNTs exhibited strong interactions with α-synuclein, with phosphorus-doped CNTs having the most substantial interactions. Conclusion: Doped-CNTs, especially phosphorus-doped carbon nanotube could effectively prevent α-synuclein amyloid formation, thus, it could be considered as a potential treatment for Parkinson\'s disease. However, further in vitro and clinical investigations are required.

Carbon-based tubular materials have sparked a great interest in future electronics and optoelectronics device applications. In this work, we computationally studied the mechanical properties of nanotubes generated from popgraphene (PopNTs). Popgraphene is a 2D carbon allotrope composed of 5-8-5 rings. We carried out fully atomistic reactive (ReaxFF) molecular dynamics for PopNTs of different chiralities ( n , 0 and 0 , n ) and/or diameters and at different temperatures (from 300 up to 1200 K). Results showed that the tubes are thermally stable (at least up to 1200 K). All tubes presented stress/strain curves with a quasi-linear behavior followed by an abrupt drop of stress values. Interestingly, armchair-like PopNTs ( 0 , n ) can stand a higher strain load before fracturing when contrasted to the zigzag-like ones ( n , 0 ). Moreover, it was obtained that Young\'s modulus (YMod ) (750-900 GPa) and ultimate strength (σUS ) (120-150 GPa) values are similar to the ones reported for conventional armchair and zigzag carbon nanotubes. YMod values obtained for PopNTs are not significantly temperature-dependent. While the σUS values for the 0 , n showed a quasi-linear dependence with the temperature, the n , 0 exhibited no clear trends.

Due to unique features in surface activity, thermal stability, electrical and thermal conductivity, and compatibility with biomolecules such as DNA and proteins, carbon-based nanoparticles are raised potential as a candidate for various applications such as catalytic processes, drug delivery, light, and electrical engineering. Based on this premise, thermodynamic features of pure, graphene, and carbon nanotube (CNT)-based gold nanoparticles (AuNPs) are investigated using molecular dynamics approach. Melting, heat capacity, thermal conductivity, contact angle of molten AuNPs, and phase transition are calculated as indicators of thermodynamic properties of pure and carbon-based AuNPs. Simulation results indicate that the presence of a carbon platform and its contact surface area has a significant role in the thermodynamic properties of AuNPs and leads the phononic heat capacity and thermal conductivity to decrease for AuNPs. The platform also causes the melting point temperature of AuNPs to increase. The melting of gold on the carbon base is of the first-order type. In addition, contact angle for molten AuNPs on the Graphene is significantly higher than the one on the CNT due to more contact area on the Graphene substrate.Graphical abstract .