| 311. |
- Joshi, S. V., et al.
(författare)
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Plasma spraying of an indigenous yttria stabilized zirconia powder prepared by the sol-gel technique
- 1993
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Ingår i: Bulletin of Materials Science. - : Springer India. ; 16:1, s. 19-28
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Tidskriftsartikel (refereegranskat)abstract
- An indigenous sol-gel derived yttria-partially stabilized zirconia (Y-PSZ) powder has been characterized and its suitability for plasma spraying applications evaluated. The powder, determined to have about 5·1% yttria content, predominantly consisted of spherical particles with an average equivalent particle diameter close to 25 μm. Furthermore, it was found that the powder did not contain any particles >50 μm, which is considered the ideal upper size limit for spray-grade ceramic powders in order to ensure complete melting during spraying. The sol-gel produced powder exhibited good flow characteristics and the plasma sprayed coatings developed using this powder were also found to have excellent thermal shock resistance. The corresponding results obtained using an imported Y-PSZ powder are also presented for the purpose of comparison. © 1993 Indian Academy of Sciences.
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| 312. |
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| 313. |
- Karoly, Janik, et al.
(författare)
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The JCMT BISTRO Survey: Studying the Complex Magnetic Field of L43
- 2023
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Ingår i: Astrophysical Journal. - 1538-4357 .- 0004-637X. ; 952:1
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Tidskriftsartikel (refereegranskat)abstract
- We present observations of polarized dust emission at 850 mu m from the L43 molecular cloud, which sits in the Ophiuchus cloud complex. The data were taken using SCUBA-2/POL-2 on the James Clerk Maxwell Telescope as a part of the BISTRO large program. L43 is a dense (N-H2 similar to 10(22) - 10(23) cm(-2)) complex molecular cloud with a submillimeter-bright starless core and two protostellar sources. There appears to be an evolutionary gradient along the isolated filament that L43 is embedded within, with the most evolved source closest to the Sco OB2 association. One of the protostars drives a CO outflow that has created a cavity to the southeast. We see a magnetic field that appears to be aligned with the cavity walls of the outflow, suggesting interaction with the outflow. We also find a magnetic field strength of up to similar to 160 +/- 30 mu G in the main starless core and up to similar to 90 +/- 40 mu G in the more diffuse, extended region. These field strengths give magnetically super- and subcritical values, respectively, and both are found to be roughly trans-Alfvenic. We also present a new method of data reduction for these denser but fainter objects like starless cores.
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| 314. |
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| 315. |
- Kim, Shi En, et al.
(författare)
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Extremely anisotropic van der Waals thermal conductors
- 2021
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 597:7878, s. 660-665
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Tidskriftsartikel (refereegranskat)abstract
- The densification of integrated circuits requires thermal management strategies and high thermal conductivity materials1–3. Recent innovations include the development of materials with thermal conduction anisotropy, which can remove hotspots along the fast-axis direction and provide thermal insulation along the slow axis4,5. However, most artificially engineered thermal conductors have anisotropy ratios much smaller than those seen in naturally anisotropic materials. Here we report extremely anisotropic thermal conductors based on large-area van der Waals thin films with random interlayer rotations, which produce a room-temperature thermal anisotropy ratio close to 900 in MoS2, one of the highest ever reported. This is enabled by the interlayer rotations that impede the through-plane thermal transport, while the long-range intralayer crystallinity maintains high in-plane thermal conductivity. We measure ultralow thermal conductivities in the through-plane direction for MoS2 (57 ± 3 mW m−1 K−1) and WS2 (41 ± 3 mW m−1 K−1) films, and we quantitatively explain these values using molecular dynamics simulations that reveal one-dimensional glass-like thermal transport. Conversely, the in-plane thermal conductivity in these MoS2 films is close to the single-crystal value. Covering nanofabricated gold electrodes with our anisotropic films prevents overheating of the electrodes and blocks heat from reaching the device surface. Our work establishes interlayer rotation in crystalline layered materials as a new degree of freedom for engineering-directed heat transport in solid-state systems.
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| 316. |
- Klingelhoefer, L., et al.
(författare)
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Dystonia Non-Motor Symptoms Questionnaire (DNMSQuest) zur Erhebung nichtmotorischer Symptome bei Dystonie : Interkulturelle Adaptation in deutscher Sprache
- 2020
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Ingår i: Nervenarzt. - : Springer Science and Business Media LLC. - 0028-2804. ; 91, s. 337-342
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Tidskriftsartikel (refereegranskat)abstract
- Background: Non-motor symptoms (NMS) in patients with dystonia have a relevant impact on health-related quality of life; however, a comprehensive easy to use NMS assessment tool for clinical bedside use is currently not available. Objective: The validated German version of the dystonia non-motor symptoms questionnaire (DNMSQuest) for assessing NMS in craniocervical dystonia is presented. Methods: The DNMSQuest in the German language was developed based on internationally recognized standards for intercultural adaptation of self-completed patient questionnaires. Translation of the original English questionnaire into the German language as well as back translation to English was carried out independently by four bilingual specialists in neurological movement disorders. In each case a consensus version accepted by each translator was created by another neurologist. The back translated English version was compared with the original English questionnaire for relevant linguistic and content discrepancies by a neurologist who was significantly involved in the development of the original questionnaire. The final German version was used in 130 patients with cervical dystonia and 48 healthy controls in an international, multicenter validation study. Results: An interculturally adapted validated version of the DNMSQuest in the German and English languages was developed for rapid bedside assessment and evaluation of NMS in cervical dystonia. Conclusion: The DNMSQuest successfully bridges the current gap of a validated disease-specific, patient self-administered, short, comprehensive questionnaire for NMS assessment in routine clinical practice in craniocervical dystonia. It is envisaged that this tool will be useful for the clinical practice and trials.
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| 317. |
- Kocis, Petr, et al.
(författare)
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Elucidating the Aβ42 Anti-Aggregation Mechanism of Action of Tramiprosate in Alzheimer's Disease: Integrating Molecular Analytical Methods, Pharmacokinetic and Clinical Data.
- 2017
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Ingår i: CNS drugs. - : Springer Science and Business Media LLC. - 1179-1934 .- 1172-7047. ; , s. 1-15
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Tidskriftsartikel (refereegranskat)abstract
- Amyloid beta (Aβ) oligomers play a critical role in the pathogenesis of Alzheimer's disease (AD) and represent a promising target for drug development. Tramiprosate is a small-molecule Aβ anti-aggregation agent that was evaluated in phase III clinical trials for AD but did not meet the primary efficacy endpoints; however, a pre-specified subgroup analysis revealed robust, sustained, and clinically meaningful cognitive and functional effects in patients with AD homozygous for the ε4 allele of apolipoprotein E4 (APOE4/4 homozygotes), who carry an increased risk for the disease. Therefore, to build on this important efficacy attribute and to further improve its pharmaceutical properties, we have developed a prodrug of tramiprosate ALZ-801 that is in advanced stages of clinical development. To elucidate how tramiprosate works, we investigated its molecular mechanism of action (MOA) and the translation to observed clinical outcomes.The two main objectives of this research were to (1) elucidate and characterize the MOA of tramiprosate via an integrated application of three independent molecular methodologies and (2) present an integrated translational analysis that links the MOA, conformation of the target, stoichiometry, and pharmacokinetic dose exposure to the observed clinical outcome in APOE4/4 homozygote subjects.We used three molecular analytical methods-ion mobility spectrometry-mass spectrometry (IMS-MS), nuclear magnetic resonance (NMR), and molecular dynamics-to characterize the concentration-related interactions of tramiprosate versus Aβ42 monomers and the resultant conformational alterations affecting aggregation into oligomers. The molecular stoichiometry of the tramiprosate versus Aβ42 interaction was further analyzed in the context of clinical pharmacokinetic dose exposure and central nervous system Aβ42 levels (i.e., pharmacokinetic-pharmacodynamic translation in humans).We observed a multi-ligand interaction of tramiprosate with monomeric Aβ42, which differs from the traditional 1:1 binding. This resulted in the stabilization of Aβ42 monomers and inhibition of oligomer formation and elongation, as demonstrated by IMS-MS and molecular dynamics. Using NMR spectroscopy and molecular dynamics, we also showed that tramiprosate bound to Lys16, Lys28, and Asp23, the key amino acid side chains of Aβ42 that are responsible for both conformational seed formation and neuronal toxicity. The projected molar excess of tramiprosate versus Aβ42 in humans using the dose effective in patients with AD aligned with the molecular stoichiometry of the interaction, providing a clear clinical translation of the MOA. A consistent alignment of these preclinical-to-clinical elements describes a unique example of translational medicine and supports the efficacy seen in symptomatic patients with AD. This unique "enveloping mechanism" of tramiprosate also provides a potential basis for tramiprosate dose selection for patients with homozygous AD at earlier stages of disease.We have identified the molecular mechanism that may account for the observed clinical efficacy of tramiprosate in patients with APOE4/4 homozygous AD. In addition, the integrated application of the molecular methodologies (i.e., IMS-MS, NMR, and thermodynamics analysis) indicates that it is feasible to modulate and control the Aβ42 conformational dynamics landscape by a small molecule, resulting in a favorable Aβ42 conformational change that leads to a clinically relevant amyloid anti-aggregation effect and inhibition of oligomer formation. This novel enveloping MOA of tramiprosate has potential utility in the development of disease-modifying therapies for AD and other neurodegenerative diseases caused by misfolded proteins.
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| 318. |
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| 319. |
- Kumari, P., et al.
(författare)
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An all phosphorene lattice nanometric spin valve
- 2024
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Phosphorene is a unique semiconducting two-dimensional platform for enabling spintronic devices integrated with phosphorene nanoelectronics. Here, we have designed an all phosphorene lattice lateral spin valve device, conceived via patterned magnetic substituted atoms of 3d-block elements at both ends of a phosphorene nanoribbon acting as ferromagnetic electrodes in the spin valve. Through First-principles based calculations, we have extensively studied the spin-dependent transport characteristics of the new spin valve structures. Systematic exploration of the magnetoresistance (MR) of the spin valve for various substitutional atoms and bias voltage resulted in a phase diagram offering a colossal MR for V and Cr-substitutional atoms. Such MR can be directly attributed to their specific electronic structure, which can be further tuned by a gate voltage, for electric field controlled spin valves. The spin-dependent transport characteristics here reveal new features such as negative conductance oscillation and switching of the sign of MR due to change in the majority spin carrier type. Our study creates possibilities for the design of nanometric spin valves, which could enable integration of memory and logic elements for all phosphorene 2D processors.
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| 320. |
- Kumari, P., et al.
(författare)
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High efficiency spin filtering in magnetic phosphorene
- 2020
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : ROYAL SOC CHEMISTRY. - 1463-9076 .- 1463-9084. ; 22:10, s. 5893-5901
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Tidskriftsartikel (refereegranskat)abstract
- Phosphorene has a unique set of characteristics such as a semiconducting nature, good carrier mobility and low-spin orbit coupling aspects which makes it a highly prospective two dimensional material for cross-hybrid architectures in nanoelectronics, spintronics, and optoelectronics. In the spintronic context, the creation of a stable magnetic order in phosphorene can be immensely beneficial for designing phosphorene spin circuits. In this work, we present high efficiency spin filtering behaviour in magnetically rendered phosphorene. First, we calculate the effect of doping various 3d block elements in phosphorene to introduce a stable magnetic order. Next, by varying doping concentrations in distinct doping configurations, an extensive phase diagram has been obtained depicting the presence of various electronic and magnetic states. This allows us to achieve a high magnetisation in the presence of various transition metal atoms, with a spin polarisation of similar to 100% in half-metallic regimes. The transport behaviour reveals a map of the spin injection efficiency showing enhancement with doping concentration and reaching a perfect spin filtering capacity of similar to 100% in the presence of Ti, Cr, Mn, Co, and Fe atoms. The present results offer new insights into engineered designs of multi-functional phosphorene spintronic circuits.
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