| 1. |
- Edin, Emil, 1987-
(författare)
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Computational Insights into Atomic Scale Wear Processes in Cemented Carbides
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- As Ti-alloys become more and more utilized the need for efficient and robust manufacturing of Ti-alloy components increase in importance. Ti-alloys are more difficult to machine than e.g. steel, mainly due to their poor thermal conductivity leading to rapid tool wear. The atomic scale processes responsible for this wear is not well understood. Here the focus is turned to the effects of C diffusion out of the tools as a source of the observed wear. A combination of Density Functional Theory (DFT) making use of Harmonic Transition State Theory (HTST), classical Molecular Dynamics (MD) and kinetic Monte Carlo (kMC) is used to investigate C diffusion into and within experimentally observed WC/W interfaces that exists as a consequence of the C depletion. Further, tools are built and used to evaluate interface parameters for large sets of interfaces within the WC/W system to determine which are energetically preferred. The results from the DFT study show stable interfaces with large differences in activation energy between the two most prominent surfaces found in WC materials, namely the basal and prismatic surfaces. Within the WC/W interfaces the diffusion barriers are similar between the two. The classical MD simulations support the view of stable interfaces at the early stages of C depletion. As C is removed this picture shifts to one in which the diffusion barriers are substantially decreased and the difference between the basal and the prismatic interfaces vanish pointing to a process which starts out slow but accelerates as C is continually removed. From the kMC simulations the overall diffusion pre-factor and activation energy is estimated to be D0=1.8x10-8 m2/s and dE=1.24 eV for the investigated [10-10]-I/[100] interface, the kMC simulations also confirm previous results indicating that the diffusion is restricted to the interface region. The investigation and screening of properties for WC/W interfaces show a preference for the W terminated [10-10]-I/[110] and [0001]/[110] interface combinations based on the interfacial energy.
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| 2. |
- Gupta, Shantanu, et al.
(författare)
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Network analysis reveals that the tumor suppressor lncRNA GAS5 acts as a double-edged sword in response to DNA damage in gastric cancer
- 2022
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- The lncRNA GAS5 acts as a tumor suppressor and is downregulated in gastric cancer (GC). In contrast, E2F1, an important transcription factor and tumor promoter, directly inhibits miR-34c expression in GC cell lines. Furthermore, in the corresponding GC cell lines, lncRNA GAS5 directly targets E2F1. However, lncRNA GAS5 and miR-34c remain to be studied in conjunction with GC. Here, we present a dynamic Boolean network to classify gene regulation between these two non-coding RNAs (ncRNAs) in GC. This is the first study to show that lncRNA GAS5 can positively regulate miR-34c in GC through a previously unknown molecular pathway coupling lncRNA/miRNA. We compared our network to several in-vivo/in-vitro experiments and obtained an excellent agreement. We revealed that lncRNA GAS5 regulates miR-34c by targeting E2F1. Additionally, we found that lncRNA GAS5, independently of p53, inhibits GC proliferation through the ATM/p38 MAPK signaling pathway. Accordingly, our results support that E2F1 is an engaging target of drug development in tumor growth and aggressive proliferation of GC, and favorable results can be achieved through tumor suppressor lncRNA GAS5/miR-34c axis in GC. Thus, our findings unlock a new avenue for GC treatment in response to DNA damage by these ncRNAs.
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| 3. |
- Panda, Pritam Kumar, PhD Student, 1991-, et al.
(författare)
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Structure-based drug designing and immunoinformatics approach for SARS-CoV-2
- 2020
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 6:28
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Tidskriftsartikel (refereegranskat)abstract
- The prevalence of respiratory illness caused by the novel SARS-CoV-2 virus associated with multiple organ failures is spreading rapidly because of its contagious human-to-human transmission and inadequate globalhealth care systems. Pharmaceutical repurposing, an effective drug development technique using existing drugs, could shorten development time and reduce costs compared to those of de novo drug discovery. We carried out virtual screening of antiviral compounds targeting the spike glycoprotein (S), main protease (M-pro), and the SARS-CoV-2 receptor binding domain (RBD)-angiotensin-converting enzyme 2 (ACE2) complex of SARS-CoV-2. PC786, an antiviral polymerase inhibitor, showed enhanced binding affinity to all the targets. Furthermore, the postfusion conformation of the trimeric S protein RBD with ACE2 revealed conformational changes associated with PC786 drug binding. Exploiting immunoinformatics to identify T cell and B cell epitopes could guide future experimental studies with a higher probability of discovering appropriate vaccine candidates with fewer experiments and higher reliability.
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| 4. |
- Zhao, Xiaofeng, et al.
(författare)
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Strain-Engineered Metal-Free h-B2O Monolayer as a Mechanocatalyst for Photocatalysis and Improved Hydrogen Evolution Reaction
- 2020
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Ingår i: The Journal of Physical Chemistry C. - : AMER CHEMICAL SOC. - 1932-7447 .- 1932-7455. ; 124:14, s. 7884-7892
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Tidskriftsartikel (refereegranskat)abstract
- Developing stable metal-free materials with a highly efficient hydrogen evolution reaction (HER) has received intense research interest due to its renewable and environmentally friendly properties. In this work, we systematically investigated the HER catalytic activity of a new h-B2O monolayer based on first-principles calculations. The results show the B site in the h-B2O structure is energetically favorable for hydrogen with the calculated Gibbs free energy (Delta G(H*)) of -0.07 eV, which is comparable to that of the Pt catalyst (Delta G(H*)) = -0.09 eV). Moreover, the catalytic activity of the h-B2O monolayer is quite robust with increasing hydrogen coverages (from 1/9 to 9/9). Interestingly, the HER activity of the h-B2O monolayer is sensitive to the strains-driven. For example, applied tensile strains (0-2%) could weaken the bonding between hydrogen and the substrate, resulting in Delta G(H*) even close to 0 eV. However, the opposite trend is found for applied compressive strain. After analyzing the density of states (DOS), we found the h-B2O monolayer with absorbed hydrogen retains the metallic property, still exhibiting excellent electrical conductivity. These results reveal that the metal-free h-B2O monolayer is a promising candidate for HER applications.
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