| 1. |
- Aad, G, et al.
(author)
-
- 2015
-
swepub:Mat__t
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Beal, Jacob, et al.
(author)
-
Robust estimation of bacterial cell count from optical density
- 2020
-
In: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
-
Journal article (peer-reviewed)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
|
|
| 6. |
- Gerkin, RC, et al.
(author)
-
The best COVID-19 predictor is recent smell loss: a cross-sectional study
- 2020
-
In: medRxiv : the preprint server for health sciences. - : Cold Spring Harbor Laboratory.
-
Journal article (other academic/artistic)abstract
- BackgroundCOVID-19 has heterogeneous manifestations, though one of the most common symptoms is a sudden loss of smell (anosmia or hyposmia). We investigated whether olfactory loss is a reliable predictor of COVID-19.MethodsThis preregistered, cross-sectional study used a crowdsourced questionnaire in 23 languages to assess symptoms in individuals self-reporting recent respiratory illness. We quantified changes in chemosensory abilities during the course of the respiratory illness using 0-100 visual analog scales (VAS) for participants reporting a positive (C19+; n=4148) or negative (C19-; n=546) COVID-19 laboratory test outcome. Logistic regression models identified singular and cumulative predictors of COVID-19 status and post-COVID-19 olfactory recovery.ResultsBoth C19+ and C19-groups exhibited smell loss, but it was significantly larger in C19+ participants (mean±SD, C19+: -82.5±27.2 points; C19-: -59.8±37.7). Smell loss during illness was the best predictor of COVID-19 in both single and cumulative feature models (ROC AUC=0.72), with additional features providing negligible model improvement. VAS ratings of smell loss were more predictive than binary chemosensory yes/no-questions or other cardinal symptoms, such as fever or cough. Olfactory recovery within 40 days was reported for ∼50% of participants and was best predicted by time since illness onset.ConclusionsAs smell loss is the best predictor of COVID-19, we developed the ODoR-19 tool, a 0-10 scale to screen for recent olfactory loss. Numeric ratings ≤2 indicate high odds of symptomatic COVID-19 (4<OR<10), which can be deployed when viral lab tests are impractical or unavailable.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Kong, P. P., et al.
(author)
-
Superconductivity in Strong Spin Orbital Coupling Compound Sb2Se3
- 2014
-
In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 4, s. 6679-
-
Journal article (peer-reviewed)abstract
- Recently, A(2)B(3) type strong spin orbital coupling compounds such as Bi2Te3, Bi2Se3 and Sb2Te3 were theoretically predicated to be topological insulators and demonstrated through experimental efforts. The counterpart compound Sb2Se3 on the other hand was found to be topological trivial, but further theoretical studies indicated that the pressure might induce Sb2Se3 into a topological nontrivial state. Here, we report on the discovery of superconductivity in Sb2Se3 single crystal induced via pressure. Our experiments indicated that Sb2Se3 became superconductive at high pressures above 10 GPa proceeded by a pressure induced insulator to metal like transition at similar to 3 GPa which should be related to the topological quantum transition. The superconducting transition temperature (T-C) increased to around 8.0 K with pressure up to 40 GPa while it keeps ambient structure. High pressure Raman revealed that new modes appeared around 10 GPa and 20 GPa, respectively, which correspond to occurrence of superconductivity and to the change of T-C slop as the function of high pressure in conjunction with the evolutions of structural parameters at high pressures.
|
|
| 10. |
- Meresse, Y, et al.
(author)
-
X-ray diffraction studies of AuCu3-type neptunium compounds under pressure
- 2000
-
In: JOURNAL OF ALLOYS AND COMPOUNDS. - : ELSEVIER SCIENCE SA. - 0925-8388. ; 296:1-2, s. 27-32
-
Journal article (peer-reviewed)abstract
- NpX3 (AuCu3-type structure) compounds with X=Al, Ga, Ge, In and Sn were studied up to 50 GPa using the energy dispersive X-ray diffraction (EDXRD) technique. No structural phase transitions were observed for any of the compounds studied up to the highest
|
|
| 11. |
- Panda, Pritam Kumar, PhD Student, 1991-, et al.
(author)
-
Molecular nanoinformatics approach assessing the biocompatibility of biogenic silver nanoparticles with channelized intrinsic steatosis and apoptosis
- 2022
-
In: Green Chemistry. - : Royal Society of Chemistry (RSC). - 1463-9262 .- 1463-9270. ; 24:3, s. 1190-1210
-
Journal article (peer-reviewed)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.
|
|
| 12. |
|
|
| 13. |
- Rkhis, M., et al.
(author)
-
Engineering the hydrogen storage properties of the perovskite hydride ZrNiH3 by uniaxial/biaxial strain
- 2022
-
In: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 47:5, s. 3022-3032
-
Journal article (peer-reviewed)abstract
- In the present work, the bonding length, electronic structure, stability, and dehydrogenation properties of the Perovskite-type ZrNiH3 hydride, under different uniaxial/biaxial strains are investigated through ab-initio calculations based on the plane-wave pseudopotential (PW-PP) approach. The findings reveal that the uniaxial/biaxial compressive and tensile strains are responsible for the structural deformation of the ZrNiH3 crystal structure, and its lattice deformation becomes more significant with decreasing or increasing the strain magnitude. Due to the strain energy contribution, the uniaxial/biaxial strain not only lowers the stability of ZrNiH3 but also decreases considerably the dehydrogenation enthalpy and decomposition temperature. Precisely, the formation enthalpy and decomposition temperature are reduced from -67.73 kJ/mol.H2 and 521 K for non-strained ZrNiH3 up to -33.73 kJ/mol.H2 and 259.5 K under maximal biaxial compression strain of epsilon = -6%, and to -50.99 kJ/mol.H2 and 392.23 K for the maximal biaxial tensile strain of epsilon = +6%. The same phenomenon has been also observed for the uniaxial strain, where the formation enthalpy and decomposition temperature are both decreased to -39.36 kJ/mol.H2 and 302.78 K for a maximal uniaxial compressive strain of epsilon = - 12%, and to -51.86 kJ/mol.H2 and 399 K under the maximal uniaxial tensile strain of epsilon = +12%. Moreover, the densities of states analysis suggests that the strain-induced variation in the dehydrogenation and structural properties of ZrNiH3 are strongly related to the Fermi level value of total den- sities of states. These ab-initio calculations demonstrate insightful novel approach into the development of Zr-based intermetallic hydrides for hydrogen storage practical applications. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
|
|
| 14. |
- Abdel-Hafiez, Mahmoud, et al.
(author)
-
Pressure-induced reentrant transition in NbS3 phases : Combined Raman scattering and x-ray diffraction study
- 2019
-
In: Physical Review B. - : AMER PHYSICAL SOC. - 2469-9950 .- 2469-9969. ; 99:23
-
Journal article (peer-reviewed)abstract
- We report the evolution of charge density wave states under pressure for two NbS3 phases: triclinic (phase I) and monoclinic (phase II) at room temperature. Raman and x-ray diffraction (XRD) techniques are applied. The x-ray studies on the monoclinic phase under pressure show a compression of the lattice at different rates below and above similar to 7 GPa but without a change in space group symmetry. The Raman spectra of the two phases evolve similarly with pressure; all peaks almost disappear in the similar to 6-8 GPa range, indicating a transition from an insulating to a metallic state, and peaks at new positions appear above 8 GPa. The results suggest suppression of the ambient charge-density waves and their subsequent recovery with new orderings above 8 GPa.
|
|
| 15. |
|
|
| 16. |
- Ahuja, Satpal, et al.
(author)
-
Epilogue
- 2011
-
In: Usher Syndrome: Pathogenesis, Diagnosis and Therapy. - 9781612092270 ; , s. 429-434
-
Book chapter (other academic/artistic)
|
|
| 17. |
- Ahuja, Satpal, et al.
(author)
-
MicroRNAs in Retinal Pathophysiology and Therapeutics
- 2011
-
In: Usher Syndrome: Pathogenesis, Diagnosis and Therapy. - 9781612092270 ; , s. 199-211
-
Book chapter (peer-reviewed)abstract
- Following identification of tRNA and rRNA, the non-protein coding RNAs (ncRNAs) have been demonstrated to possess catalytic ribozyme functions (Cech et al., 1981; Guerrier-Takada et al., 1983). In recognition of the latter work, T.R. Cech and S. Altman were awarded the 1989 Noble Prize in Chemistry. Fire, et al. (1998) discovered that small double stranded RNA (ds RNA) silences the gene expression. For this observation Andre Fire and C.C. Mello earned the 2006 Nobel Prize in Physiology or Medicine. Two years later, V.R. Ambros, D.C. Baucombe, and G.B. Ruvkun were honored with the Albert Lasker Basic Medical Research Award (2008) for their contributions in the field of small RNA dependent gene regulation in plants and animals. All these findings have revolutionized the fields of gene regulation, RNA biology and brought out the possibilities of its exploitation for understanding the living processes and for use as therapeutic agents.
|
|
| 18. |
- Ahuja, Satpal, et al.
(author)
-
Preface
- 2011
-
In: Usher Syndrome: Pathogenesis, Diagnosis and Therapy. - 9781612092270
-
Book chapter (other academic/artistic)
|
|
| 19. |
- Arapan, S., et al.
(author)
-
Formation of sp(3) hybridized bonds and stability of CaCO3 at very high pressure
- 2007
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 98:26
-
Journal article (peer-reviewed)abstract
- By performing ab initio electronic structure calculations, we observed a new high-pressure phase transition within the Pmcn structure of CaCO3. This transition is characterized by the change of the carbon's sp hybridization state and is driven by the intrinsic property of the carbon atom to form tetrahedral covalent bonds at high pressure. The formation of sp(3) hybridized bonds explains the stability of MgCO3 and CaCO3 at Earth's lower mantle pressure conditions and may serve as a criterion for searching new possible high-pressure phases of carbon bearing minerals.
|
|
| 20. |
- Da Silva, A. F., et al.
(author)
-
Electronic and optical properties of TiO2
- 2005
-
Conference paper (peer-reviewed)abstract
- The electronic and optical properties of the rutile titanium dioxide compound have been investigated experimentally by absorption measurements and theoretically by a full-potential linearized augmented plane wave (FPLAPW) method within the local density approximation (LDA). The thin films for the absorption measurements were prepared by DC magnetron sputtering. The theoretical results for the absorption compared qualitatively well with the experimental findings. The dielectric functions and band-structure have also been calculated, and the LDA band-gap energy is corrected by an on-site Coulomb potential.
|
|
| 21. |
- da Silva, A. F., et al.
(author)
-
Electronic and optical properties of wurztzie and zinc-blende TlN and AlN
- 2005
-
In: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248 .- 1873-5002. ; 281:1, s. 151-160
-
Journal article (peer-reviewed)abstract
- We present calculations of the band structure, density of states and the real and imaginary parts of the dielectric functions in intrinsic TIN and AlN, both for wurtzite and the zinc-blende polytypes. They are based on the local density approximation (LDA) within the density functional theory (DFT), employing the first-principles, full-potential linearized augmented plane wave (FPLAPW) method. We correct the band gap of the AlN by using a quasi-particle method proposed by Bechstedt and Del Sole. The calculated energy gaps, lattice constants and dielectric constants for AlN are in good agreement with available experimental values while for TIN there is no experimental investigation.
|
|
| 22. |
- Dantas, N. S., et al.
(author)
-
Novel semiconducting materials for optoelectronic applications : Al1-xTlxN alloys
- 2008
-
In: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 92:12
-
Journal article (peer-reviewed)abstract
- We proprose the ternary semiconducting Al1-xTlxN alloys as new material for optoelectronic applications. Ab initio calculations have been performed to study structural, electronic, and optical properties of the theoretically designed thallium-aluminum based nitride alloys. We found that the lattice constants vary linearly with thallium composition whereas the band gap and absorption edge span from ultraviolet to infrared energy region by increasing thallium content which make the predicted material interesting for infrared optical devices among other technological applications.
|
|
| 23. |
- Dubrovinsky, L., et al.
(author)
-
Noblest of all metals is structurally unstable at high pressure
- 2007
-
In: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 98:4
-
Journal article (peer-reviewed)abstract
- In a series of experiments in externally electrically heated diamond anvil cells we demonstrate that at pressures above similar to 240 GPa gold adopts a hexagonal-close-packed structure. Ab initio calculations predict that at pressures about 250 GPa different stacking sequences of close-packed atomic layers in gold become virtually degenerate in energy, strongly supporting the experimental observations.
|
|
| 24. |
|
|
| 25. |
|
|
| 26. |
- Gupta, S, et al.
(author)
-
Dynamical modeling of miR-34a, miR-449a, and miR-16 reveals numerous DDR signaling pathways regulating senescence, autophagy, and apoptosis in HeLa cells
- 2022
-
In: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 12:1, s. 4911-
-
Journal article (peer-reviewed)abstract
- Transfection of tumor suppressor miRNAs such as miR-34a, miR-449a, and miR-16 with DNA damage can regulate apoptosis and senescence in cancer cells. miR-16 has been shown to influence autophagy in cervical cancer. However, the function of miR-34a and miR-449a in autophagy remains unknown. The functional and persistent G1/S checkpoint signaling pathways in HeLa cells via these three miRNAs, either synergistically or separately, remain a mystery. As a result, we present a synthetic Boolean network of the functional G1/S checkpoint regulation, illustrating the regulatory effects of these three miRNAs. To our knowledge, this is the first synthetic Boolean network that demonstrates the advanced role of these miRNAs in cervical cancer signaling pathways reliant on or independent of p53, such as MAPK or AMPK. We compared our estimated probability to the experimental data and found reasonable agreement. Our findings indicate that miR-34a or miR-16 may control senescence, autophagy, apoptosis, and the functional G1/S checkpoint. Additionally, miR-449a can regulate just senescence and apoptosis on an individual basis. MiR-449a can coordinate autophagy in HeLa cells in a synergistic manner with miR-16 and/or miR-34a.
|
|
| 27. |
- Heathman, S., et al.
(author)
-
A high-pressure structure in curium linked to magnetism
- 2005
-
In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 309:5731, s. 110-113
-
Journal article (peer-reviewed)abstract
- Curium ties at the center of the actinide series and has a half-filled shell. with seven 5f electrons spatially residing inside its radon core. As a function of pressure, curium exhibits five different crystallographic phases up to 100 gigapascals, of which all but one are also found in the preceding element, americium. We describe here a structure in curium, Cm III, with monoctinic symmetry, space group C2/c, found at intermediate pressures (between 37 and 56 gigapascals). Ab initio electronic structure calculations agree with the observed sequence of structures and establish that it is the spin polarization of curium's 5f electrons that stabilizes Cm Ill. The results reveal that curium is one of a few elements that has a lattice structure stabilized by magnetism.
|
|
| 28. |
- Heathman, S., et al.
(author)
-
Structural investigation of californium under pressure
- 2013
-
In: Physical Review B. Condensed Matter and Materials Physics. - : American Physical Society. - 1098-0121 .- 1550-235X. ; 87:21, s. 214111-
-
Journal article (peer-reviewed)abstract
- The high-pressure structural behavior of californium has been studied experimentally and theoretically up to 100 GPa. A valence change from divalent to trivalent forms was observed under modest pressure revealing californium to be the only actinide to exhibit more than one metallic valence at near to ambient conditions as is the case for cerium in the lanthanide series. Three metallic valencies and four different crystallographic phases were observed in californium as a function of pressure. High-pressure techniques, synchrotron radiation, and ab initio electronic structure calculations of total energies were used to investigate the material and to determine the role which californium's 5f electrons play in influencing these transitions. The crystallographic structures observed are similar to those found in the preceding actinide elements, curium and americium, with the initially localized 5f states becoming completely delocalized under the influence of high pressure.
|
|
| 29. |
- Heathman, S., et al.
(author)
-
The unique high-pressure behavior of curiurn probed further using alloys
- 2007
-
In: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388 .- 1873-4669. ; 444, s. 138-141
-
Journal article (peer-reviewed)abstract
- The changing role of the 5f electrons across the actinide series has been of prime interest for many years. The remarkable behavior of americium's 5f electrons under pressure was determined experimentally a few years ago and it precipitated a strong interest in the heavy element community. Theoretical treatments of americium's behavior under pressure followed and continue today. Experimental and theoretical findings regarding curium's behavior under pressure have shown that the pressure behavior of curium was not a mirror image of that for americium. Rather, one of the five crystallographic phases observed with curium (versus four for americium) was a unique monoclinic structure whose existence is due to a spin stabilization effect by curium's 5f(7) electronic configuration and its half-filled 5f-shell. We review briefly the behavior of pure curium under pressure but focus on the pressure behaviors of three curium alloys with the intent of comparing them with pure curium. An important experimental finding confirmed by theoretical computations, is that dilution of curium with its near neighbors is sufficient to prevent the formation of the unique C2/c phase that appears in pure Cm metal under pressure. As this unique C2/c phase is very sensitive to having a 5f7 configuration to maximize the magnetic spin polarization, dilution of this state with adjacent actinide neighbors reduces its stability.
|
|
| 30. |
|
|
| 31. |
- Islam, M. S., et al.
(author)
-
Augmenting the sensing aptitude of hydrogenated graphene by crafting with defects and dopants
- 2016
-
In: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 228, s. 317-321
-
Journal article (peer-reviewed)abstract
- Density functional theory (DFT) level calculations were performed to study the interaction of hydrogenated graphene (CH) monolayer towards methane (CH4) gas molecules. The structural, electronic and gas sensing properties of pure, defected and light metal-doped CH monolayer were investigated. For the pristine CH, the estimated binding energy of CH4 fell short of the desired physisorption range and limit its gas sensing application at ambient conditions. However, upon crafting defects on pure CH layer by introducing hydrogen vacancies, a sharp increase in adsorption energies were observed when the CH4 molecules approached the defected sites of CH. Further, the effect of metal doping was studied by uniformly distributing light metal adatoms on CH monolayer which significantly enhanced the CH4 adsorption. To have better accuracy in calculating adsorption energies, we have incorporated van der Waals type corrections to our calculations for these weakly interacting systems.
|
|
| 32. |
- Jha, Ealisha, et al.
(author)
-
Intrinsic atomic interaction at molecular proximal vicinity infer cellular biocompatibility of antibacterial nanopepper
- 2021
-
In: Nanomedicine. - : Future Medicine. - 1743-5889 .- 1748-6963. ; 16:4, s. 307-322
-
Journal article (peer-reviewed)abstract
- Aim: Fabrication of nanopepper (NP) for antibacterial application and elucidation of its molecular and cellular biocompatibility. Materials & methods: Synthesis of NP was achieved using a high-energy ball milling method. Following characterization, its antibacterial activity and cellular and molecular biocompatibility were evaluated in vitro by experimental and computational approaches. Results: A total of 15 h of milling pepper produced NP with a size of 44 +/- 12 nm and zeta potential of -22 +/- 12 mV. Bulk pepper and NP showed antibacterial activity and an LC50 of 1.9 mu M and 2.1 mu M in HCT116 colon cells. Components of pepper, piperine and beta-caryophyllene were found to interact with superoxide dismutase [Cu-Zn] and apoptotic protease-activating factor-1-caspase-9 through different amino acids via H-bonds. Conclusion: NP exhibits significant antibacterial activity with cellular biocompatibility due to intrinsic atomic interaction.
|
|
| 33. |
|
|
| 34. |
- Kulkarni, Shrinivas R., et al.
(author)
-
Study of Ti2SC under compression up to 47 GPa
- 2008
-
In: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388 .- 1873-4669. ; 448:1-2, s. L1-L4
-
Journal article (peer-reviewed)abstract
- The pressure dependence of the lattice parameters of the ternary layered carbide, Ti2SC, was measured by using synchrotron radiation X-ray diffraction and a diamond anvil cell setup. The experiment was conducted at room temperature and no phase transformation was observed up to the maximum pressure of 47 GPa. The a and c lattice parameters at room condition are 3.216 (A) over circle and 11.22 (A) over circle, respectively. The bulk modulus, calculated using the Birch-Murnaghan equation of state, is 191 +/- 3 GPa, with a pressure derivative of 4.0 +/- 0.3 and that obtained by our ab initio calculations is 183 GPa, with a pressure derivative of 4.1. L Like the majority of the ternary layered carbides (MAX phases), compressibility along the c-axis was higher than that along the a-axis.
|
|
| 35. |
|
|
| 36. |
- Lou, H. B., et al.
(author)
-
Pressure-induced amorphous-to-amorphous configuration change in Ca-Al metallic glasses
- 2012
-
In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 2, s. 376-
-
Journal article (peer-reviewed)abstract
- Pressure-induced amorphous-to-amorphous configuration changes in Ca-Al metallic glasses (MGs) were studied by performing in-situ room-temperature high-pressure x-ray diffraction up to about 40 GPa. Changes in compressibility at about 18 GPa, 15.5 GPa and 7.5 GPa during compression are detected in Ca80Al20, Ca72.7Al27.3, and Ca66.4Al33.6 MGs, respectively, whereas no clear change has been detected in the Ca50Al50 MG. The transfer of s electrons into d orbitals under pressure, reported for the pressure-induced phase transformations in pure polycrystalline Ca, is suggested to explain the observation of an amorphous-to-amorphous configuration change in this Ca-Al MG system. Results presented here show that the pressure induced amorphous-to-amorphous configuration is not limited to f electron-containing MGs.
|
|
| 37. |
- Mikhaylushkin, A. S., et al.
(author)
-
Structural and magnetic properties of FeHx (x=0.25; 0.50; 0.75)
- 2006
-
In: AIP Conf. Proc.. - : AIP. - 0735403295 - 9780735403291 ; , s. 161-167
-
Conference paper (peer-reviewed)abstract
- The structural and magnetic properties of the FeHx (x=0.25; 0.50; 0.75) compounds have been studied using the projector augmented wave (PAW) method within the generalized gradient approximation (GGA). We compare the hcp, dhcp and fcc structures and find that for the considered concentrations of hydrogen the hcp structure is most stable in a wide pressure range. The magnetic behavior of iron is crucially influenced by hydrogen. In particular, the local moment on a Fe atom depends on the number of hydrogen atoms in the atom surroundings. Iron atoms, which are crystallographically equivalent in their original structures (hcp, fcc) but have different number of hydrogen neighbors, are shown to have different local magnetic moments. This finding suggests that the experimental observations of two magnetic moments in iron hydride can be explained by nonstoichiometry of the hydride and might not be a direct evidence for the presence of the dhcp phase.
|
|
| 38. |
|
|
| 39. |
- Nabi, Z., et al.
(author)
-
Ferromagnetism in CdOX (X = Mn and N) with and without intrinsic point defects : A density functional theory
- 2013
-
In: RESULTS IN PHYSICS. - : Elsevier BV. - 2211-3797. ; 3, s. 205-208
-
Journal article (peer-reviewed)abstract
- The purpose of this study is to further understanding of the structural, electronic, magnetic properties of CdO doped with transition metal (Mn) and non metal element (N). The calculations are performed by the developed full-potential augmented plane wave plus local orbitals method within the spin density functional theory. As exchange-correlation potential we used the generalized gradient approximation (GGA) form. Moreover, the electronic structure study for our compounds was performed with and without oxygen deficiency. We treated the ferromagnetic and antiferromagnetic states and we found that all compounds are stable in the ferromagnetic structure, and all doped materials CdO:Mn and CdO: N adopt the half metallic character. In addition, we notice that the oxygen vacancy destroyed the ferromagnetism in N doped CdO, while Mn doped CdO becomes semiconductor.
|
|
| 40. |
- Panigrahi, P., et al.
(author)
-
Light metal decorated graphdiyne nanosheets for reversible hydrogen storage
- 2018
-
In: Nanotechnology. - : Institute of Physics (IOP). - 0957-4484 .- 1361-6528. ; 29:35
-
Journal article (peer-reviewed)abstract
- The sensitive nature of molecular hydrogen (H-2) interaction with the surfaces of pristine and functionalized nanostructures, especially two-dimensional materials, has been a subject of debate for a while now. An accurate approximation of the H-2 adsorption mechanism has vital significance for fields such as H2 storage applications. Owing to the importance of this issue, we have performed a comprehensive density functional theory (DFT) study by means of several different approximations to investigate the structural, electronic, charge transfer and energy storage properties of pristine and functionalized graphdiyne (GDY) nanosheets. The dopants considered here include the light metals Li, Na, K, Ca, Sc and Ti, which have a uniform distribution over GDY even at high doping concentration due to their strong binding and charge transfer mechanism. Upon 11% of metal functionalization, GDY changes into a metallic state from being a small band-gap semiconductor. Such situations turn the dopants to a partial positive state, which is favorable for adsorption of H-2 molecules. The adsorption mechanism of H-2 on GDY has been studied and compared by different methods like generalized gradient approximation, van der Waals density functional and DFT-D3 functionals. It has been established that each functionalized system anchors multiple H-2 molecules with adsorption energies that fall into a suitable range regardless of the functional used for approximations. A significantly high H-2 storage capacity would guarantee that light metal-doped GDY nanosheets could serve as efficient and reversible H-2 storage materials.
|
|
| 41. |
- Panigrahi, P., et al.
(author)
-
Tuning the selective sensing properties of transition metal dichalcogenides (MoX2 X= Se, Te) toward sulfurrich gases
- 2022
-
In: Materials Today Chemistry. - : Elsevier. - 2468-5194. ; 26
-
Journal article (peer-reviewed)abstract
- There is an urgent need for an efficient sensor to mitigate the effects of toxic pollutants possessing severe impacts on humans and the environment. Motivated by this, we investigated the selected transition metal dichalcogenides (MoX2: X = Se, Te) monolayers toward the toxic sulfur-containing gases, such as H2S and SO2. We employed density functional theory simulations in combination with nonequilibrium Green's function formalism to study the optimized geometries, binding strength, electronic structures, charge transfer mechanism, and transport (current-voltage) characteristics of MoX2 with and without H2S and SO2. Weak binding energies (<-0.30 eV) of H2S/SO2 on pristine MoX2 were enhanced by selectively substituting the latter with elements like As, Ge, and Sb at lower doping concentrations of around 2%. We find that the doped MoX2 strongly adsorbs H2S/SO2 yielding significant changes in their electronic properties, which were the fundamentals for the efficient sensing mechanism and were studied through the density of states and work function calculations. For the practical sensing applica-tions, we considered the statistical thermodynamic analysis to investigate the sensing properties of pristine and doped MoX2 monolayers under varied conditions of the temperatures and pressures. We are confident that our findings would pave the way for synthesizing sensitive and selective transition metal dichalcogenides-based nanosensor toward H2S/SO2.
|
|
| 42. |
- Ragupathi, V., et al.
(author)
-
Enhanced electrochemical performance of LiMnBO3 with conductive glassy phase : a prospective cathode material for lithium-ion battery
- 2017
-
In: Ionics (Kiel). - : Springer. - 0947-7047 .- 1862-0760. ; 23:7, s. 1645-1653
-
Journal article (peer-reviewed)abstract
- LiMnBO3 has been identified as a promising cathode material for next-generation lithium-ion batteries. In this study, LiMnBO3 along with glassy lithium borate material (LiMnBO3 (II)) is synthesized by sol-gel method. X-ray diffraction (XRD) analysis depicts the existence of LiBO2 glassy phase along with m-LiMnBO3 phase. Transmission electron microscopy (TEM) analysis confirms the presence of LiBO2 glassy phase. An enhanced electrical conductivity of 3.64 x 10(-7) S/cm is observed for LiMnBO3 (II). The LiBO2 glassy phase is found to promote the Li reaction kinetics in LiMnBO3 (II). The synthesized LiMnBO3 (II) delivers a first discharge capacity of 310 mAh g(-1) within a potential window of 1.5-4.5 V at C/10 rate. Further, a discharge capacity of 186 mAh g(-1) at the 27th cycle shows a better cycle performance. The enhanced capacity is due to the presence of LiBO2 glassy phase and more than one Li-ion transfer in the lithium-rich stoichiometry of LiMnBO3 (II). Density functional theory calculation reveals the exact electronic structure of m-LiMnBO3 with a band gap of 3.05 eV. A charge transfer mechanism is predicted for delithiation process of m-LiMnBO3.
|
|
| 43. |
|
|
| 44. |
- Roman, L. S., et al.
(author)
-
Optical band-edge absorption of oxide compound SnO2
- 2006
-
In: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 252:15, s. 5361-5364
-
Journal article (peer-reviewed)abstract
- Tin oxide (SnO2) is an important oxide for efficient dielectrics, catalysis, sensor devices, electrodes and transparent conducting coating oxide technologies. SnO2 thin film is widely used in glass applications due to its low infra-red heat emissivity. In this work, the SnO2 electronic band-edge structure and optical properties are studied employing a first-principle and fully relativistic full-potential linearized augmented plane wave (FPLAPW) method within the local density approximation (LDA). The optical band-edge absorption alpha(omega) of intrinsic SnO2 is investigated experimentally by transmission spectroscopy measurements and their roughness in the light of the atomic force microscopy (AFM) measurements. The sample films were prepared by spray pyrolysis deposition method onto glass substrate considering different thickness layers. We found for SnO2 qualitatively good agreement of the calculated optical band-gap energy as well as the optical absorption with the experimental results.
|
|
| 45. |
- Sahoo, Shubham, et al.
(author)
-
Remarkable enhancement of the adsorption and diffusion performance of alkali ions in two-dimensional (2D) transition metal oxide monolayers via Ru-doping
- 2024
-
In: Scientific Reports. - : Springer Nature. - 2045-2322. ; 14
-
Journal article (peer-reviewed)abstract
- Transition metal oxides (TMO) are the preferred materials for metal ion battery cathodes because of their high redox potentials and good metal-ion intercalation capacity, which serve as an outstanding replacement for layered sulphide. In this work, using first-principles calculations based on Density functional theory approach, we explored the structural and electronic properties which comprise of adsorption and diffusion behaviour along with the analysis of voltage profile and storage capacity of Ru doped two-dimensional transition metal oxide MnO2, CoO2, and NiO2 monolayers. The adsorption of alkali ions (Li, Na) to the surface of TMOs is strengthened by Ru-atom doping. Ru doping enhanced the adsorption energy of Li/Na-ion by 25%/11% for MnO2, 8%/13% for CoO2, and 10%/11% NiO2 respectively. The open circuit voltage (OCV) also increases due to the high adsorption capacity of doped Monolayers. Ru doping makes the semiconducting TMOs conduct, which is suitable for battery application. As alkali ion moves closer to the dopant site, the adsorption energy increases. When alkali ions are close to the vicinity of doping site, their diffusion barrier decrease and rises as they go further away. Our current findings will be useful in finding ways to improve the storage performance of 2D oxide materials for application in energy harvesting and green energy architecture.
|
|
| 46. |
|
|
| 47. |
- Shin, D. W., et al.
(author)
-
Size dependence of the electronic structure of copper nanoclusters in SiC matrix
- 2006
-
In: Chemical Physics Letters. - : Elsevier BV. - 0009-2614 .- 1873-4448. ; 422:4-6, s. 543-546
-
Journal article (peer-reviewed)abstract
- We studied the size dependence of the electronic structure of nanocrystalline copper embedded in silicon carbide by means of soft Xray absorption spectroscopy. Changes in the local electronic states of copper nanoclusters, including the shift in binding energy and the reduction of s-p-d hybridization, occurred. The experimental result was compared with the ab initio self-consistent, real-space, multiple-scattering calculation. The calculation was in good agreement with the trend found in our experimental results. We concluded that the reduction of d-d interaction and the concomitant changes in s-p-d hybridization in copper nanoclusters arise due to the surface effect.
|
|
| 48. |
|
|
| 49. |
|
|
| 50. |
- Sun, J., et al.
(author)
-
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
-
In: ACR Open Rheumatology. - : Wiley. - 2578-5745. ; 3:9, s. 642-653
-
Journal article (peer-reviewed)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.
|
|
