To explore the impact of vision impairment (VI) on the gait of hemiplegic patients, assess their walking ability and fall risks, and provide a basis for developing effective rehabilitation strategies.
Thirty hemiplegic patients were enrolled and stratified by the severity of visual acuity impairment into three groups (unimpaired, mildly impaired, and severely impaired). The gait data of patients under uncorrected vision were collected using the Qualisys motion capture system and the Kistler three-dimensional force platform, and the balance ability of patients was assessed simultaneously. Subsequently, the gait and assessment data were statistically analyzed to compare inter-group differences.
Compared with the visually unimpaired group, significant differences in step length, symmetry, and walking speed were observed in hemiplegic patients of the mild visual impairment group and severe visual impairment group. As VI increased, gait abnormalities became more pronounced, with a longer double-limb support phase, a longer swing phase of the affected limb, and a shorter single-limb support phase of the affected limb in the gait cycle. Compared with the visually unimpaired group, significant differences in center of pressure (COP) and COP symmetry were found between the mild visual impairment group and severe visual impairment group, with gait abnormalities intensifying. The Berg balance scale (BBS) scores showed that there was a significant difference between the visually unimpaired group and severe visual impairment group, indicating that the group with visual impairment had poorer balance ability.
VI has a significant negative impact on the gait and walking ability of hemiplegic patients. This study emphasizes the importance of focusing on the impact of VI in the rehabilitation of hemiplegic patients, with regular vision assessments and personalized interventions being conducted, which are of great significance in enhancing patients' walking quality.
To analyze the fluid resistance characteristics of different drafting formations in marathon swimming using computational fluid dynamics (CFD) method, and provide theoretical guidance for selecting optimal drafting strategies in competitions and training.
Multi-swimmer models were established via three-dimensional body scanning technology, and various formation models (I-, A-, V-, L-, H-type) were created by adjusting lateral and longitudinal distances between swimmers. The ANSYS Discovery Live software was used to simulate the overall resistance of different models and the resistance of individual swimmers within formations.
The I3-type formation exhibited an overall drag reduction effect, reducing total resistance by 55.21%, whereas other formations increased overall resistance. The V-type formation showed the most significant resistance increase (31.88%). During drafting, the lowest resistance position was the rear position in the I3-type formation, while the highest resistance position was the middle position in the L-type formation. When leading, the fluid resistance of the leading swimmer in the A-type formation was significantly greater than that of an individual swimmer (P<0.05).
Longitudinal drafting formations demonstrated superior drag reduction effects, with the rear position in a three-person longitudinal arrangement showing the optimal drag reduction. Considering both tactical considerations and drag reduction effects, swimmers are advised to avoid the middle position in lateral formations.
To investigate the dynamic balance ability of healthy young adults under different obstacle-crossing strategies, thereby providing a theoretical basis for fall prevention training and public facility design.
Twenty healthy young adults participated in the experiment using F-scan plantar pressure analysis insoles. The subjects were required to cross three obstacles with different combinations of height and width. With their dominant foot serving as the leading foot and the non-dominant foot as the trailing foot, the subjects performed both lateral and forward crossing maneuvers, and their plantar pressure data were collected.
Different crossing strategies significantly affected the adjustment speed of the leading foot's center of pressure in the medial-lateral direction (COP_ML), the area of the 95% confidence circle, ML amplitude, and anterior-posterior (AP) amplitude (P<0.05). These strategies also significantly impacted the trailing foot's COP_ML adjustment speed, the area of the 95% confidence circle, and the range between the maximum and minimum swings (P<0.05). For the leading foot, during lateral and forward crossing, the balance parameter values under different heights and widths were statistically significant (P<0.05), increasing as the height and width increased. For the trailing foot, during forward crossing, the balance parameter values under different heights were statistically significant (P<0.05), increasing with height, while during lateral crossing, the differences in balance parameter values were not statistically significant (P>0.05).
Healthy young adults demonstrate better balance ability with the leading foot during forward obstacle crossing, which aligns with the movement habits of the dominant foot and daily activity patterns. The trailing foot exhibits a more stable plantar pressure distribution during lateral obstacle crossing, likely due to a larger contact area and more even center of gravity distribution.
To study how lipid bilayer fluidity modulates the interaction between β1 integrin and CD40L, as well as the formation of CD40L-mediated tumor cell contact interfaces.
Supported lipid bilayers (SLB) with different fluidities were prepared through adjusting the 1, 2-dioleoyl-sn-glycero-3-[N-(5-amino-1-carboxypentyl) iminodiacetic acid] succinyl nickel salt (DGS-NTA) content. The functionalization of lipid bilayers was achieved by anchoring fluorescently labeled CD40L molecules onto the membrane surface. The contact interface formation of PC9 cells on the functionalized lipid bilayers was observed through confocal fluorescence imaging and fluorescence recovery after photobleaching (FRAP) experiments, and data of two dimensional (2D) reaction kinetics of β1 integrin and CD40L were extracted from Zhu-Golan plots.
The diffusion coefficient of molecules in lipid bilayer was negatively correlated with DGS-NTA content. High fluidity of lipid bilayer promoted CD40L accumulation at cell contact interface and expanded the cell contact area. The 2D dissociation constants (2D Kd) of β1 integrin-CD40L complexes were approximately 13, 31 and 65 molecules/μm2 for the three lipid bilayers with high, moderate and low fluidities, respectively.
High fluidity of lipid bilayers significantly facilitates diffusion and aggregation of CD40L to the cell contact interface, thus enhancing β1 integrin-CD40L interaction and the stability of cell contact interfaces.
To elucidate the regulatory effects of titanium surface modification on the immune function of immature dendritic cells (imDCs), different crystalline nanomorphologies were constructed on titanium surface to investigate the mechanobiological response of imDCs to nanomorphologies with different crystalline phases.
Nanomorphologies with different crystalline phases were constructed on the titanium surface by anodic oxidation and calcination. The changes of the cytoskeleton F-actin, cell adhesion and morphology of imDCs cultured on nanomorphologies with different crystalline phases were observed by fluorescence staining. The relative gene expression of adhesion molecules was detected by quantitative real-time PCR. The migration behaviors of imDCs were observed using real-time live-cell imaging, and the membrane fluidity was detected by fluorescence polarization.
Nanomorphologies with different crystalline phases, namely amorphous phase, anatase and rutile, were obtained on the titanium surface by anodic oxidation and calcination. The cytoskeleton of imDCs on nanomorphologies with different crystalline phases was remodeled. The spreading area of cells on anatase crystalline phase was relatively small, which was (353.3±148.5) μm2. The number of adherent cells was the largest, which was 587±132. The expression of adhesion molecules such as CD11a, integrin β2, ICAM1, and VCAM1 were also increased in cells which cultured on anatase crystalline phase. The imDCs cultured on anatase crystalline phase were equipped with strong migration ability. The accumulative migration distance was (383.6±177.7) μm, and the Euclidean migration distance was (51.82±50.13) μm. The membrane fluidity was relatively weak, and the fluorescence polarization was 0.348 5±0.041 8.
imDCs can respond to nanomorphologies with different crystalline phases on the titanium surface and exhibit different biomechanical behaviors. The results might provide a theoretical basis for the design of titanium biomaterials with immunomodulatory functions.
To analyze the effects and differences of two veno-arterial extracorporeal membrane oxygenation (VA-ECMO) cannulation methods and subsequent left ventricular unloading on cardiac function and hemodynamics.
The lumped parameter model (LPM) of VA-ECMO integrated with the cardiovascular system in the MATLAB/Simulink environment was extended to simulate and analyze the changes in ventricular function and blood flow in the heart failure patient model under central VA-ECMO or peripheral VA-ECMO support. The effects of using arterial vasodilators or a left atrial drainage cannula on left ventricular function under central VA-ECMO support at a pump flow rate of 3 L/min were compared.
Under central VA-ECMO or peripheral VA-ECMO support, left ventricular pressure and volume increased, and stroke volume and ventricular work decreased. Both arterial vasodilators and the left atrial drainage cannula could reduce left ventricular pressure and volume. Arterial vasodilators additionally increased stroke volume and improved left ventricular ejection fraction from 11.6% to 19.5%.
Both VA-ECMO cannulation methods provide effective circulatory support in the heart failure patient model, with similar effects on ventricular function. Under central VA-ECMO support, arterial vasodilators can improve left ventricular function more effectively than the left atrial drainage cannula.
Cardiovascular diseases are the leading cause of death worldwide, and hemodynamics plays a significant role in understanding the mechanisms of these diseases, predicting disease progression, and guiding treatment strategies. Traditional methods for obtaining personalized hemodynamic parameters in clinical settings have numerous limitations, while the rise of deep learning technology has brought new opportunities for their computation. This review focuses on the application of deep learning in obtaining hemodynamic parameters in clinical settings, covering its progress in computational fluid dynamics preprocessing, hemodynamic computation (data-driven and PINN method), and magnetic resonance anagiography. It analyzes the advantages and challenges of each method and discusses future development directions, aiming to provide a reference for research on obtaining hemodynamic parameters in clinical settings using artificial intelligence method.
To analyze the reverse mechano-electric effect of the layered structure of articular cartilage and its influencing factors.
The cartilage samples were classified according to their physiological thickness (approximately 0.4 mm for the upper layer, 1 mm for the middle layer, and 0.6 mm for the lower layer). Through a non-contact external electric field testing method, how different influencing factors affected the reverse mechano-electric effect of articular cartilage was analyzed.
When the electric field spacing decreased, water content increased, and in vitro time decreased, the displacement of normal layered cartilage in a non-contact electric field increased by 18, 10, 15 μm, respectively. In the case of simulated arthritis defects, as the defect depth and radius increased, the overall deviation deflection of articular cartilage gradually decreased by about 7 μm.
The three-layer cartilage differed in their reverse mechano-electricity effects, showing the greatest deflection in the middle layer at 90% water content, under 7 mm electric field spacing, and after 12 hours ex vivo.
The wear debris generated during artificial joint prosthesis service can react with bone tissues to form osteolysis, seriously affecting the life-time of artificial joint prostheses. This paper reviews, summarizes, and analyzes domestic and international research literature on the extraction, characterization, and identification of wear debris from different artificial joint materials, aiming to provide references and feasible ideas for the future construction of a systematic and hierarchical research system for artificial joint wear debris. The main findings are as follows: strong alkali protein degradation test, strong acid protein degradation test, and protease protein degradation test are the commonly used method for extracting artificial joint wear debris, and researchers have clarified the protein degradation mechanisms of these three debris extraction methods. The characterization of wear debris in-vitro and in-vivo is mostly for hip and knee joints, with a small amount involving cervical spine and ankle joints. Studies have shown that the size, quantity, shape, and volume of wear particles are influenced by factors such as joint type, contact area, material selection, and implantation time. Both domestic and international studies have conducted characterization research on wear debris after in-vitro simulation testing, but there is still a lack of wear debris characterization analysis of clinical retrievals in China. Currently, most research is on the recognition of wear debris in the traditional mechanical field, but research on the intelligent recognition of artificial joint wear debris is relatively few, indicating that there is a certain lag in the application of computer technology in the field of artificial joint wear debris recognition.
Knee osteoarthritis (OA) is a primary cause of joint dysfunction. Knee osteotomy has garnered significant attention due to its potential to delay the progression of knee OA and enhance joint function. As a pivotal biomechanical factor in the onset and progression of OA, the accurate correction of abnormal knee alignment is the central objective of knee osteotomy. This article systematically reviews the biomechanical research progress related to knee osteotomy, with a focus on the precision and personalized correction of force line. The development of new classification system and measurement technology of force line is summarized, the biomechanical mechanism of knee OA induced by abnormal mechanical load is analyzed, and the goal of force line and clinical application progress of knee osteotomy is discusses, so as to provide a new perspective and idea for the clinical treatment of knee OA with knee osteotomy.