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1. Accelerating GW Calculations of Point Defects with the Defect-Patched Screening Approximation

   https://doi.org/10.1021/acs.jctc.3c01032  

   Li, Du; Liu, Zhen-Fei; Yang, Li (December 2023, Journal of Chemical Theory and Computation)
2. Synthesis and Properties of the Helium Clathrate and Defect Perovskite [He _2–x □ _x ][CaNb]F ₆

   https://doi.org/10.1021/acs.jpcc.4c02174  

   Ma, Shangye; Hester, Brett_R; Lloyd, II, Anthony_J; dos_Santos, Antonio_M; Molaison, Jamie_J; Wilkinson, Angus_P (June 2024, The Journal of Physical Chemistry C)
3. The swimming defect caused by the absence of the transcriptional regulator LdtR in Sinorhizobium meliloti is restored by mutations in the motility genes motA and motS

   https://doi.org/10.1111/mmi.15247  

   Sobe, Richard C.; Scharf, Birgit E. (March 2024, Molecular Microbiology)

   Abstract The flagellar motor is a powerful macromolecular machine used to propel bacteria through various environments. We determined that flagellar motility of the alpha‐proteobacteriumSinorhizobium melilotiis nearly abolished in the absence of the transcriptional regulator LdtR, known to influence peptidoglycan remodeling and stress response. LdtR does not regulate motility gene transcription. Remarkably, the motility defects of the ΔldtRmutant can be restored by secondary mutations in the motility genemotAor a previously uncharacterized gene in the flagellar regulon, which we namedmotS. MotS is not essential forS. melilotimotility and may serve an accessory role in flagellar motor function. Structural modeling predicts that MotS comprised an N‐terminal transmembrane segment, a long‐disordered region, and a conserved β‐sandwich domain. The C terminus of MotS is localized in the periplasm. Genetics based substitution of MotA with MotA_G12Salso restored the ΔldtRmotility defect. The MotA_G12Svariant protein features a local polarity shift at the periphery of the MotAB stator units. We propose that MotS may be required for optimal alignment of stators in wild‐type flagellar motors but becomes detrimental in cells with altered peptidoglycan. Similarly, the polarity shift in stator units composed of MotB/MotA_G12Smight stabilize its interaction with altered peptidoglycan. 

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4. Defect generation in TiO ₂ nanotube anodes via heat treatment in various atmospheres for lithium-ion batteries

   https://doi.org/10.1039/c8cp04368j  

   Savva, Andreas I.; Smith, Kassiopeia A.; Lawson, Matthew; Croft, Sterling R.; Weltner, Ariel E.; Jones, Chris D.; Bull, Hailey; Simmonds, Paul J.; Li, Lan; Xiong, Hui (January 2018, Physical Chemistry Chemical Physics)

   In this paper, ordered TiO 2 nanotubes were grown on a Ti substrate via electrochemical anodization and subsequently annealed at 450 °C for 4 h under various atmospheres to create different point defects. Oxygen-deficient environments such as Ar and N 2 were used to develop oxygen vacancies, while a water vapor (WV) atmosphere was used to generate titanium vacancies. Computational models by density functional theory predicted that the presence of oxygen vacancies would cause electronic conductivity to increase, while the presence of Ti vacancies could lead to decreased conductivity. The predictions were confirmed by two-point electrical conductivity measurements and Mott–Schottky analysis. Raman spectroscopy was also conducted to confirm the presence of defects. The annealed samples were then evaluated as anodes in lithium-ion batteries. The oxygen-deficient samples had an improvement in capacity by 10% and 25% for Ar- and N 2 -treated samples, respectively, while the WV-treated sample displayed a capacity increase of 24% compared to the stoichiometric control sample (annealed in O 2 ). Electrochemical impedance spectroscopy studies revealed that the WV-treated sample's increased capacity was a consequence of its higher Li diffusivity. The results suggest that balanced electrical and ionic conductivity in nanostructured metal oxide anodes can be tuned through defect generation using heat treatments in various atmospheres for improved electrochemical properties. 

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5. Defect and local uniformization

   https://doi.org/10.1007/s13398-019-00717-1  

   Cutkosky, Steven Dale; Mourtada, Hussein (October 2019, Revista de la Real Academia de Ciencias Exactas, Físicas y Naturales. Serie A. Matemáticas)