The first catalytic asymmetric construction of 3,3'-bisindole skeletons bearing both axial and central chirality has been established by organocatalytic asymmetric addition reactions of 2-substituted 3,3'-bisindoles with 3-indolylmethanols (up to 98 % yield, all >95:5 d.r., >99 % ee). This reaction also represents the first highly enantioselective construction of axially chiral 3,3'-bisindole skeletons, and utilizes the strategy of introducing a bulky group to the ortho-position of prochiral 3,3'-bisindoles. This reaction not only provides a good example for simultaneously controlling axial and central chirality in one operation, but also serves as a new strategy for catalytic enantioselective construction of axially chiral 3,3'-bisindole backbones from prochiral substrates.
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http://dx.doi.org/10.1002/anie.201811177 | DOI Listing |
Am J Vet Res
January 2025
Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria, South Africa.
Objective: The aim was to investigate the patellar ligament strain with varying degrees of tibial plateau angles (TPAs) after tibial plateau leveling osteotomy (TPLO) in a cranial cruciate ligament (CrCL)-deficient stifle during the stance phase.
Methods: 12 pelvic cadaver limbs were secured to a custom-built jig to mimic a loadbearing stance after which an axial load of 120 N was applied. Patellar ligament strain, change in strain, and percent change in strain were calculated on pre-TPLO (intact and transected CrCL) and post-TPLO tibial TPAs of -5°, 0°, 5°, 10°, and 15°.
Dalton Trans
January 2025
Department of Chemistry and Bioscience, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea.
Porphyrin-based two-dimensional porous materials (SnP-H2TCPP, SnP-ZnTCPP) composed of robust Sn(IV)-porphyrin linkages have been synthesized by reacting -dihydroxo[5,10,15,20-tetraphenylporphyrinato]tin(IV) (SnP) with [5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin] (HTCPP) and [5,10,15,20-tetrakis(4-carboxyphenyl)porphyrinato]zinc(II) (ZnTCPP), respectively. The strength of the interaction between the carboxylic acid group of the monomeric porphyrins (HTCPP and ZnTCPP) and the axial hydroxyl moiety of SnP enables the construction of highly stable framework materials, which were characterized by FT-IR, UV-vis, and emmission spectroscopy, powder XRD, elemental analysis, and thermogravimetric analysis (TGA). SnP-H2TCPP and SnP-ZnTCPP absorb visible light strongly over a wide range, demonstrating weak perturbation in the electronic ground state structures of the π-conjugated aromatic moieties compared to the starting monomeric units.
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December 2024
School of Civil Engineering, Central South University, Changsha, 410075, China.
An improved method tailored for anisotropic soft soils is presented, integrating theoretical models and field data to calculate the grouting quantity required for tunnel foundations. Given the complexities of soil interactions, particularly under variable geological conditions, this approach incorporates nonlinear behaviors and empirical field data to improve accuracy. Our findings reveal that integrating these theoretical frameworks significantly enhances the understanding of stress-strain behavior during grouting, enabling precise calculations of both axial and vertical expansion.
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December 2024
Department of Orthopaedics and Traumatology, The University of Hong Kong, Pok Fu Lam, Hong Kong.
Establishing normative values and understanding how proprioception varies among body parts is crucial. However, the variability across individuals, especially adolescents, makes it difficult to establish norms. This prevents further investigation into classifying patients with abnormal proprioception.
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November 2024
Aerospace Engineering, Universiti Putra Malaysia, Kuala Lumpur, MYS.
Introduction Spinal fusion surgery with pedicle screws is commonly performed to stabilize the spine of osteoporotic patients. However, securing a strong screw fixation in osteoporotic bone presents significant challenges due to the reduced bone density. This study aimed to compare the biomechanical performance in an osteoporotic bone model of pedicle screws inserted using two different techniques, the Jamshidi needle technique and the pedicle probe technique, as well as the influence of tapping on both these techniques.
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