Reorganization of corticospinal tract in a patient with posterior limb infarct of the internal capsule

Several diffusion tensor-imaging studies have demonstrated motor recovery mechanisms in stroke patients with subcortical infarct, including the corona radiata, pons, and medulla. However, studies of motor recovery mechanisms have not been reported in patients with posterior limb infarcts of the intemal capsule. The present study reports on a 77-year-old man with complete paralysis of the left extremities at stroke onset. At 6 months after onset, motor function of the left extremities recovered to a nearly normal state. The 3-week diffusion tensor tractography of the affected （right） hemisphere showed that corticospinal tract discontinued below the posterior limb. In contrast, 6-month diffusion tensor tractography revealed that the right corticospinal tract originated from the precentral gyrus and descended along the anterior area of the infarcted posterior limb. Motor function of the affected extremities was reorganized into the anterior area of the posterior limb infarct.

Nonlinear Energy Cascading in Turbulence during the Internal Reconnection Event at the Sino-United Spherical Tokamak

The characteristics of the energy transfer and nonlinear coupling among edge electromagnetic turbulence in thermal quench sub-period of the internal reconnection event （IRE） are studied at the sino-united spherical tokamak device using multiple Langmuir and magnetic probe arrays. The wavelet bispectral analysis and the modified Kim method are applied to investigate linear growth/damping and nonlinear energy transfer rates, along with multi-field turbulence interactions. The results show a multi-field nonlinear energy transfer from electrostatic to magnetic turbulence that results in two-mode coupling in magnetic turbulence, which may play a crucial role to trigger the IRE.

Validity Study on the Test Paper of the Academic English Reading and Writing Course

The aim of this study is to conduct the validity analysis of the test paper of the academic English reading and writing course referring to the freshmen of non-English majors in a university of Technology in Shanghai.The validity is mainly analyzed from these three aspects:the content and construct validity,the reaction process,and the internal structure of the test paper.And the principles of language assessment in the design of the test paper are given in this study.The validity study was also conducted in a class with 42 freshmen,and the scores of them were analyzed through the internal correlation coefficient from Statistic Package for Social Science(SPSS)25.0.Finally,the validity of the test paper is concluded.

Investigation on the potential barrier to internal rotation in molecules——Ab initio calculation and energy partition of the internal rotation barrier in complex molecule H_3N-BH_3

Based on the ab initio/6-31Gcalculation, the potential barrier to internal rotation in mol-ecule HN--BHhas been studed by means of PD/LSF atomic charge model and Buckingham（exp--6-1）energy partition method. The results indicate that the order of the contributions of the componentsto the total energy barrier △E is |△V|（electrostatic） >|△V| （charge transfer）>|△V| （exchangerepulsion）>|△V| （dispersion）. For △Vthere are maxima at θ= 30°and 90°, and a saddle atθ= 60°. There are good linear relationships for the total barrier △E, △Vand △Vwith cos3θrespectively, and the same for the dipole moment from PD/LSF model (μ) and that from abinitio calculation (μ) vs. cos3θ respectively.

Isolation and mechanism analysis of a catalytic efciency improved L‑aspartateβ‑decarboxylase toward 3‑methylaspartic acid

L-Aspartateβ-decarboxylase from Acinetobacter radioresistens(ArASD)has been modifed to convert 3-methylaspartic acid into 2-aminobutyric acid,which activated a novel process for biosynthesis of 2-aminobutyric acid.However,the process is limited by the low activity of the ArASD.Here,the activity of ArASD was signifcantly improved by modifcation based on sequence alignment and structural analysis.The 38th residue of ArASD is speculated to be the key residue for regulating the conformation of the internal aldimine,and site-directed mutagenesis on R38 residue was carried out.A variant,K18A/R38K/V287I,with 2.2 times higher specifc activity was isolated.Molecular dynamics simulation indicated that the torsion angle of the imine bond of the variant decreased,which was benefcial to the protonation of the internal aldimine and the increase in the initial energy of the enzyme.Therefore,the energy barrier of the transition state was reduced,resulting in improved catalytic activity toward 3-methylaspartic acid.These results provide a reference and a new point of view for enzyme modifcation by increasing the energy of the initial state.