| 1. |
|
|
| 2. |
- Silvearv, Fredrik, et al.
(författare)
-
Establishing the most favorable metal-carbon bond strength for carbon nanotube catalysts
- 2015
-
Ingår i: Journal of Materials Chemistry C. - : Royal Society of Chemistry (RSC). - 2050-7526 .- 2050-7534. ; 3:14, s. 3422-3427
-
Tidskriftsartikel (refereegranskat)abstract
- We have studied a wide range of transition metals to find potential carbon nanotube (CNT) catalysts for chemical vapor deposition (CVD) production. The adhesion strengths between a CNT and a metal cluster were calculated using first principle density functional theory (DFT) for all 1st, 2nd and 3rd row transition metals. We have developed the criterion that the metal-carbon adhesion strength per bond must fulfill a Goldilocks principle for catalyzing CNT growth and used it to identify, besides the well known catalysts Fe, Co and Ni, a number of other potential catalysts, namely Y, Zr, Rh, Pd, La, Ce and Pt. Our results are consistent with previous experiments performed either in a carbon arc discharge environment or by a CVD-process with regard to CNT catalyst activity
|
|
| 3. |
- Larsson, Peter, 1979-, et al.
(författare)
-
Calculating carbon nanotube–catalyst adhesion strengths
- 2007
-
Ingår i: Physical Review B. Condensed Matter and Materials Physics. - : American Physical Society. - 1098-0121 .- 1550-235X. ; 75:11
-
Tidskriftsartikel (refereegranskat)abstract
- Density-functional theory is used to assess the validity of modeling metal clusters as single atoms or rings of atoms when determining adhesion strengths between clusters and single-walled carbon nanotubes (SWNTs). Representing a cluster by a single atom or ring gives the correct trends in SWNT-cluster adhesion strengths (Fe ≈ Co > Ni), but the single-atom model yields incorrect minimum-energy structures for all three metals. We have found that this is because of directional bonding between the SWNT end and the metal cluster, which is captured in the ring model but not by the single atom. Hence, pairwise potential models that do not describe directional bonding correctly, and which are commonly used to study these systems, are expected to give incorrect minimum-energy structures.
|
|
| 4. |
|
|
| 5. |
- Grigoriev, Anton, et al.
(författare)
-
Electron transport in stretched monoatomic gold wires
- 2006
-
Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 97, s. 236807-
-
Tidskriftsartikel (refereegranskat)abstract
- The conductance of monoatomic gold wires containing 3-7 gold atoms has been obtained from ab initio calculations. The transmission is found to vary significantly depending on the wire stretching and the number of incorporated atoms. Such oscillations are determined by the electronic structure of the one-dimensional (1D) part of the wire between the contacts. Our results indicate that the conductivity of 1D wires can be suppressed without breaking the contact.
|
|
| 6. |
- Panda, Pritam Kumar, PhD Student, 1991-, et al.
(författare)
-
Molecular nanoinformatics approach assessing the biocompatibility of biogenic silver nanoparticles with channelized intrinsic steatosis and apoptosis
- 2022
-
Ingår i: Green Chemistry. - : Royal Society of Chemistry (RSC). - 1463-9262 .- 1463-9270. ; 24:3, s. 1190-1210
-
Tidskriftsartikel (refereegranskat)abstract
- The developmental rapidity of nanotechnology poses higher risks of exposure to humans and the environment through manufactured nanomaterials. The multitude of biological interfaces, such as DNA, proteins, membranes, and cell organelles, which come in contact with nanoparticles, is influenced by colloidal and dynamic forces. Consequently, the ensued nano-bio interface depends on dynamic forces, encompasses many cellular absorption mechanisms along with various biocatalytic activities, and biocompatibility that needs to be investigated in detail. Addressing the issue, the study offers a novel green synthesis strategy for antibacterial AgNPs with higher biocompatibility and elucidates the mechanistic in vivo biocompatibility of silver nanoparticles (AgNPs) at the cellular and molecular levels. The analysis ascertained the biosynthesis of G-AgNPs with the size of 25 ± 10 nm and zeta potential of-29.2 ± 3.0 mV exhibiting LC50 of 47.2 μg mL-1 in embryonic zebrafish. It revealed the mechanism as a consequence of abnormal physiological metabolism in oxidative stress and neutral lipid metabolism due to dose-dependent interaction with proteins such as he1a, sod1, PEX protein family, and tp53 involving amino acids such as arginine, glutamine and leucine leading to improper apoptosis. The research gave a detailed insight into the role of diverse AgNPs-protein interactions with a unique combinatorial approach from first-principles density functional theory and in silico analyses, thus paving a new pathway to comprehending their intrinsic properties and usage.
|
|
| 7. |
- Sun, J., et al.
(författare)
-
Effects of Atorvastatin on T-Cell Activation and Apoptosis in Systemic Lupus Erythematosus and Novel Simulated Interactions With C-Reactive Protein and Interleukin 6
- 2021
-
Ingår i: ACR Open Rheumatology. - : Wiley. - 2578-5745. ; 3:9, s. 642-653
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: We study activation of T helper 17 (Th17) and regulatory T (Treg) cells and induction of apoptosis in cells from patients with systemic lupus erythematosus (SLE) compared with controls and effects of atorvastatin and its simulated interactions with other compounds. Methods: Mononuclear cells from 10 patients with SLE and 10 controls were cultured in conditions that induce Th17 and/or Treg cell polarization and/or apoptosis and were studied by FACScan. Gene expression was determined by quantitative real-time reverse transcription–polymerase chain reaction. Cytokines in plasma were determined by enzyme-linked immunosorbent assay. The Search Tool for Interactions of Chemicals (STITCH) was used to retrieve information regarding the binding properties of atorvastatin. Results: Among patients with SLE, the proportion of Th17 (CD4+IL17+) cells was higher compared with controls after activation, with Th17 or Treg polarizing cytokines, phorbol myristate acetate, and ionomycin. In contrast, Treg cells (CD4+CD25+CD127dim/−) frequencies were lower. CD95 stimulation induced relatively more apoptosis in Treg cells and less in Th17 cells, as compared with controls. Addition of atorvastatin normalized Th17/Treg cell balance and apoptosis induction. Accordingly, the ratio of RORC/FoxP3 decreased in patients with SLE. Interleukin 17 and interleukin 6 (IL-6) levels were increased in patients with SLE. Atorvastatin interacted strongly with C-reactive protein (CRP) and also significantly with IL-6. Conclusion: There is a higher proportion of Th17 cells and a lower proportion of Treg cells in patients with SLE after activation. Th17 cells were more resistant than Treg cells to CD95-induced apoptosis in SLE. Atorvastatin normalized these effects. Our findings reveal a novel mechanism behind the imbalance of Th17/Treg cells with implications for treatment in SLE. We determine for the first time simulated interaction between atorvastatin, CRP, and IL-6, implying a novel role of atorvastatin.
|
|
| 8. |
- Ahuja, Rajeev, et al.
(författare)
-
Electronic and optical properties of lead iodide
- 2002
-
Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 92:12, s. 7219-7224
-
Tidskriftsartikel (refereegranskat)abstract
- The electronic properties and the optical absorption of lead iodide (PbI2) have been investigated experimentally by means of optical absorption and spectroscopic ellipsometry, and theoretically by a full-potential linear muffin-tin-orbital method. PbI2 has been recognized as a very promising detector material with a large technological applicability. Its band-gap energy as a function of temperature has also been measured by optical absorption. The temperature dependence has been fitted by two different relations, and a discussion of these fittings is given.
|
|
| 9. |
|
|
| 10. |
- Arhammar, C., et al.
(författare)
-
A theoretical study of possible point defects incorporated into alpha-alumina deposited by chemical vapor deposition
- 2013
-
Ingår i: Theoretical Chemistry accounts. - : Springer Science and Business Media LLC. - 1432-881X .- 1432-2234. ; 133:2, s. 1433-
-
Tidskriftsartikel (refereegranskat)abstract
- The energetics and electronic structure of carbon, chlorine, hydrogen, and sulfur in alpha-Al2O3 was investigated by first principles and thermodynamical calculations. These species are present in the gas phase during the synthesis of alpha-Al2O3 by chemical vapor deposition (CVD) but little is known of their solubility in this compound. The heat of formation from standard reference states of the elements varying the chemical potential of each element was calculated. An attempt to model the actual conditions in the CVD process was made, using the species and solid compounds present in a common CVD process as reference states. Our calculations suggest that sulfur from the catalyzing agent H2S will not solve in alpha-Al2O3 during deposition by CVD. It is found that the neutral chlorine and hydrogen interstitial defects display the lowest heat of formation, 281 and 280 kJ/mol, respectively, at the modeled CVD conditions. This energy is too high in order for neutral defects to form during CVD of alpha-Al2O3 at any significant amounts. The charged defects and their compensation were studied. Carbon substituting oxygen is found to be energetically favored under the modeled CVD conditions, considering carbon dioxide as competing species to solid solubility in alpha-Al2O3 at an energy of -128 kJ/mol. However, care needs to be taken when choosing the possible competing carbon-containing phases. Compensation of carbon substituting for oxygen by oxygen vacancies takes place at 110 kJ/mol from standard reference states, graphite, fcc-Al and O-2. The carbon solubility in Al2O3 is difficult to measure with standard analysis techniques such as X-ray diffraction and energy dispersive X-ray spectroscopy, but several stable compounds in the Al-C-O are available in the literature.
|
|
