Objective: Functionality and quality of life in patients with osteoarthritis undergoing total arthroplasty of the knee. Materials and Methods: This study was conducted in Ziauddin hospital, Karachi from April 2018 until August 2018, making up 40 individuals who have osteoarthrosis of the knee with an indication for total arthroplasty and not being carriers of any other disease affecting the limbs lower. Two scales of evaluation were applied at two different times: pre and postoperative. Health status questionnaire (SF-36) and Knee injury and osteoarthritis outcome score (KOOS) was applied and answered in the preoperative period (on the day of surgery) and the sixth postoperative week. Results: Regarding the dimensions of activities of daily living and activities, sporting and leisure activities were not statistically significant. Our results go against the conclusions reported by Culliton [1], in a study of 13 patients submitted to TKA. The participants were evaluated before the arthroplasty and four weeks later and the results showed that there was a tendency for pain to decrease in that period. Conclusion: It can be concluded that there was a tendency to decrease pain in this period accompanied by an improvement in the quality of life. Taking into account the results obtained, and stressing the concept that quality of life is related to the state of health of the person and that pain and functional limitation caused by OA negatively influence the well-being and the performance of the activities of the person's daily life, it can be concluded that the TCA contributes to the improvement of the performance of the person. Keywords: Osteoarthritis, Joint, Arthroplasty, Articular cartilage, Osteoarthrosis, Knee injury, QoL.
Herein the reaction mechanism and the origin of stereoselectivity of asymmetric hydrogenation of oximes to hydroxylamines catalyzed by the cyclometalated iridium (III) complexes with chiral substituted single cyclopentadienyl ligands (Ir catalysts A1 and B1) under acidic condition were unveiled using DFT calculations. The catalytic cycle for this reaction consists of the dihydrogen activation step and the hydride transfer step. The calculated results indicate that the hydride transfer step is the chirality-determining step and the involvement of methanesulfonate anion (MsO−) in this reaction is of importance in the asymmetric hydrogenation of oximes catalyzed by A1 and B1. The calculated energy barriers for the hydride transfer steps without an MsO− anion are higher than those with an MsO− anion. The differences in Gibbs free energies between TSA5−1fR/TSA5−1fS and TSB5−1fR/TSB5−1fS are 13.8/13.2 (ΔΔG‡ = 0.6 kcal/mol) and 7.5/5.6 (ΔΔG‡ = 1.9 kcal/mol) kcal/mol for the hydride transfer step of substrate protonated oximes with E configuration (E−2a−H+) with MsO− anion to chiral hydroxylamines product R−3a/S−3a catalyzed by A1 and B1, respectively. According to the Curtin–Hammet principle, the major products are hydroxylamines S−3a for the reaction catalyzed by A1 and B1, which agrees well with the experimental results. This is due to the non-covalent interactions among the protonated substrate, MsO− anion and catalytic species. The hydrogen bond could not only stabilize the catalytic species, but also change the preference of stereoselectivity of this reaction.
In this paper the density functional theory (DFT) method was employed to investigate the cross‐coupling of methanol with benzyl alcohol to afford methyl benzoate, catalysed by Mn‐PNN pincer complex. The whole reaction process mainly includes three stages: the dehydrogenation of benzyl alcohol to benzaldehyde, the coupling of benzaldehyde with methanol to hemiacetal and the dehydrogenation of hemiacetal to methyl benzoate. The calculated results indicated that two dehydrogenation processes are influenced by two competitive mechanisms of inner and outer spheres. Dehydrogenation of benzyl alcohol to benzaldehyde is the rate‐determining step of the whole reaction, with the energy barrier of 22.1 kcal/mol. In addition, the regeneration of catalyst is also extremely important. Compared with direct dehydrogenation, the dehydrogenation mode assisted by formic acid is more advantageous. This work might provide theoretical insights and shed light on the design of cheap transition‐metal catalysts for the dehydrogenation reaction.
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