Trends in cognitive function before and after stroke in China

Abstract Background While cognitive impairment after stroke is common, cognitive trends before stroke are poorly understood, especially among the Chinese population who have a relatively high stroke burden. We aimed to model the trajectories of cognitive function before and after new-onset stroke among Chinese. Methods A total of 13,311 Chinese participants aged ≥ 45 years and without a history of stroke were assessed at baseline between June 2011 and March 2012 and in at least one cognitive test between 2013 (wave 2) and 2018 (wave 4). Cognitive function was assessed using a global cognition score, which included episodic memory, visuospatial abilities, and a 10-item Telephone Interview of Cognitive Status (TICS-10) test to reflect calculation, attention, and orientation abilities. Results During the 7-year follow-up, 610 (4.6%) participants experienced a first stroke. Both stroke and non-stroke groups showed declined cognitive function during follow-up. After adjustment for covariates, there was no significant difference in pre-stroke cognitive trajectories between stroke patients and stroke-free participants. The stroke group showed an acute decline in episodic memory (− 0.123 SD), visuospatial abilities (− 0.169 SD), and global cognition (− 0.135 SD) after stroke onset. In the years following stroke, the decline rate of the TICS-10 test was higher than the rate before stroke (− 0.045 SD/year). Conclusions Chinese stroke patients had not experienced steeper declines in cognition before stroke compared with stroke-free individuals. Incident stroke was associated with acute declines in global cognition, episodic memory, visuospatial abilities, and accelerated declines in calculation, attention, and orientation abilities

Effect of annealing on electrochemical performance of anodized Tio2 nanotubes for lithium ion batteries

The effect of annealing on TiO2 nanotube arrays as anode for lithium ion batteries by X-ray diffraction, field emission scanning electron microscopy, cyclic voltammetry, galvanostatic charge-discharge testing, and electrochemical impedance spectroscopy was investigated. The crystalline structure of TiO2 nanotube can be changed by controlling the annealing temperature and the crystallization also has considerable effect on electrochemical performance. Amorphous TiO2 annealed at 250 °C shows the highest discharge capacity in coin cell tests with a discharge capacity of about 67 μAh cm-2 and good cycling stability during 50 charge-discharge cycles. The electrochemical impedance spectroscopy results show the smallest resistance compared to the other samples

Shear Localization and Mechanical Properties of Cu/Ta Metallic Nanolayered Composites: A Molecular Dynamics Study

With their excellent mechanical properties, Cu/Ta metallic nanolayered composites (MNCs) are extensively applied in aerospace and nuclear industry facilities. However, shear localization severely disrupts the ability of these materials to deform uniformly, attracting many researchers. The necessary time and length conditions of experiments limit the investigation of shear localization; thus, relevant studies are insufficient. The molecular dynamics simulation perfectly corresponds to the short duration and high strain rate of the deformation process. Therefore, in this study, we used molecular dynamics simulations to explore the effect of layer thickness on the shear localization of Cu/Ta MNCs with Kurdjumov–Sachs (KS) orientation–related interfaces. Our research demonstrates that shear localization occurs in samples with layer thicknesses below 2.5 nm, resulting in an inverse size effect on the flow strength. The quantitative analysis indicates that the asymmetry of dislocations in the slip transmission across the interface causes interface rotation. This activates dislocations parallel to the interface to glide beyond the distance of individual layer thicknesses, eventually forming shear bands. Both interface rotation and sliding dominate the plastic deformation in the shear band region. In addition, the dislocation density and amorphous phase increase with decreasing layer thickness

Oil generation threshold depth of Songliao Basin: Revision and its significance

A systematic analysis was carried out on the relation curve of hydrocarbon transformation ratio vs. buried depth and that of vitrinite reflectance (Ro) vs. buried depth in Binbei area, major source rock area (Qijia-Gulong Sag and Sanzhao Sag), and major source rock layer (Cretaceous Qing-1 Member, Qing-2 – Qing-3 Members) in Songliao Basin, to re-determine the oil generation threshold depth of the basin. The oil generation threshold depth of the major source rocks is likely to range from 1400 m to 1700 m, rather than 1 200 m in the previous estimation. The change of oil generation threshold has different effects on the resources potential and exploration orientation of various areas: For the major source rock areas, increase of oil generation threshold depth will cause decrease of oil generation and expulsion quantity, with no evident effect on the resources potential of major source rock area but with certain effect on the exploration orientation and favorable target evaluation. For the Binbei area with shallower buried depth of source rocks, it will have great effect on the exploration potential, exploration orientation, and favorable target evaluation. For the southeastern uplift area with great denudation in the basin, the oil generation threshold depth is reduced to about 700 m, which will improve the exploration potential of Chaoyanggou terrace, Changchunling anticline, and Binxian-Wangfu area. Key words: Songliao Basin, oil generation threshold depth, oil generation peak, major source rock area, major source rock layer, exploration potentia

Structure Characterization and Impact Effect of Al-Cu Graded Materials Prepared by Tape Casting

With the need of developing new materials, exploring new phenomenon, and discovering new mechanisms under extreme conditions, the response of materials to high-pressure compression attract more attention. However, the high-pressure state deviating from the Hugoniot line is difficult to realize by conventional experiments. Gas gun launching graded materials could reach the state. In our work, the corresponding Al-Cu composites and graded materials are prepared by tape casting and hot-pressing sintering. The microstructure and the acoustic impedance of the corresponding Al-Cu composites are analyzed to explain the impact behavior of Al-Cu graded materials. Computed tomographic testing and three-dimension surface profilometry machine results demonstrated well-graded structure and parallelism of the graded material. Al-Cu GMs with good parallelism are used to impact the Al-LiF target at 2.3 km/s using a two-stage light-gas gun, with an initial shock impact of 20.6 GPa and ramping until 27.2 GPa, deviating from the Hugoniot line

Automatic measurement of Centreline segregation in continuously cast line pipe steel slabs

Centreline segregation appears as a positive segregation of alloying elements like C, Mn and P in the mid thickness region of continuously cast slabs. It is an intrinsic phenomenon for the casting process and it is almost impossible to mitigate through post processing. Centreline segregation can be harmful to the weldability and integrity of any fabricated steel product, especially line pipe. At present, there is no international consensus on evaluation methods of centreline segregation. A repeatable and objective method for evaluation of centreline segregation is highly desirable for both steelmaking process improvement and also for the prediction of final product performance. In the current work, a MATLAB program based on image analysis was developed to evaluate the images of centreline segregation by automatic measurement of segregation features. The original grey scale images of the centre line segregation were reduced to black and white images for automatic measurement. The black features of the image, representing areas of element segregation, were identified according to predefined criteria. The degree of segregation was evaluated based on equations which were developed by considering different parameters of the segregation segments, and also was evaluated by rules gleaned from experienced steelmakers