The impact of backpack load on adolescent's stair descent gait.

This study investigates the impact of increasing backpack load on the gait of adolescents during stair descent. Sixteen healthy male students (age = 12.9 ± 0.6 years) were required to descend the stairs in 4 loaded conditions. The kinematic, kinetic, and EMG data were collected synchronously and gait parameters, especially indicators of balance control, were analyzed. The posterior tilt angles (COM-COP IA in the sagittal plane) (0 %-42 %, 48 %-53 %, 58 %-91 %, p < 0.01), trunk anterior tilt angles (9-33 %, 51-65 %, p < 0.01), and CV of stride length (p < 0.01) increased with the backpack load. The COM-Step edge separation decreased with the increased backload (p < 0.01). In addition, the hip flexion torque (25-40 %, 45-51 %, p < 0.01), the rectus femoris activation, and the hip stiffness increased significantly as the load up to 15 % Body Weight (BW)and 20 % BW. The increasing backpack load may affect adolescent's stair descent gait. Especially as the load was up to 15 % BW, the adolescents' bodies tended to tilt backwards relative to the support foot during the single stance phase. They may activate the hip flexors and tilt forward the trunk to recover from the balance perturbation, which was associated with increased hip flexion torques. This adjustment was more pronounced with the increasing backpack load. However, excessive forward flexion may increase the risk of forward falls. The boundaries of adjustment need further research in the future. Findings from this study provide baseline information on the intrinsic mechanisms of balance control during stair descent.

Effects of Mobile Phone Use on Gait and Balance Control in Young Adults: A Hip-Ankle Strategy.

BACKGROUND: This study aimed to derive the effects of walking while using a mobile phone on balance perturbation and joint movement among young adults. METHODS: Sixteen healthy college students with no history of brain injury were tested. The participants were asked to walk under four different conditions: (1) walking, (2) browsing, (3) dialing, and (4) texting. Indicators related to balance control and lower limb kinematic/kinetic parameters were analyzed using the continuous relative phase and statistical nonparametric mapping methods. RESULTS: Walking while using a mobile phone slowed participants' gait speed and reduced the cadence, stride length, and step length. The posterior tilt angle (0-14%, 57-99%), torque of the hip flexion (0-15%, 30-35%, 75-100%), and angle of the hip flexion (0-28%, 44-100%) decreased significantly. The activation of biceps femoris and gastrocnemius, hip stiffness, and ankle stiffness increased significantly. This impact on gait significantly differed among three dual tasks: texting > browsing > dialing. CONCLUSION: Che overlap of walking and mobile phone use affects the gait significantly. The "hip-ankle strategy" may result in a "smooth" but slower gait, while this strategy was deliberate and tense. In addition, this adjustment also increases the stiffness of the hip and ankle, increasing the risk of fatigue. Findings regarding this effect may prove that even for young healthy adults, walking with mobile phone use induces measurable adjustment of the motor pattern. These results suggest the importance of simplifying the control of the movement.

Increase in Cd Tolerance through Seed-Borne Endophytic Fungus Epichloë gansuensis Affected Root Exudates and Rhizosphere Bacterial Community of Achnatherum inebrians.

Soil cadmium (Cd) pollution is a serious environmental problem imperiling food safety and human health. The endophyte Epichloë gansuensis can improve the tolerance of Achnatherum inebrians to Cd stress. However, it is still unknown whether and how the endophyte helps host plants build up a specific bacterial community when challenged by CdCl2. In this study, the responses of the structure and function of bacterial community and root exudates of E+ (E. gansuensis infected) and E- (E. gansuensis uninfected) plants to Cd stress were investigated. Analysis of bacterial community structure indicated that the rhizosphere bacterial community predominated over the root endosphere bacterial community in enhancing the resistance of CdCl2 in a host mediated by E. gansuensis. E+ plant strengthened the interspecific cooperation of rhizosphere bacterial species. Moreover, the analysis of root exudates demonstrated E. gansuensis and increased the contents of organic acids and amino acids under Cd stress, and most root exudates were significantly correlated with rhizosphere bacteria. These results suggested that E. gansuensis employed a specific strategy to recruit distinct rhizosphere bacterial species and relevant functions by affecting root exudates to improve the tolerance of the host to Cd stress. This study provides a firm foundation for the potential application of symbionts in improving phytostabilization efficiency.

Ultrasound-Guided Dry Needling for Trigger Point Inactivation in the Treatment of Postherpetic Neuralgia Mixed with Myofascial Pain Syndrome: A Prospective and Controlled Clinical Study.

Objective: To evaluate the safety and effectiveness of ultrasound-guided dry needling for trigger point inactivation in the treatment of postherpetic neuralgia (PHN) mixed with myofascial pain syndrome (MPS). Methods: A prospective and controlled clinical study was conducted. From January 2020 to December 2020, among the 100 patients who received PHN treatment in the pain department, 54 patients complicated with MPS were randomly divided into the dry needling group D (n = 28) and pharmacotherapeutic group P (n = 26). Visual analogue score (VAS) and McGill Pain Questionnaire (MPQ) were taken as primary indicators. Ultrasound-guided inactivation of myofascial trigger points (MTrPs) with dry needling and intradermal needling combined with press needling were applied on group D and pharmacotherapeutic only treatment on group P respectively. The VAS score <3 and/or the MPQ score <2 represents effective treatment. The VAS score >3 and/or the MPQ score >2 represents recurrent in follow-up study three months after the treatment. Results: After four weeks treatment, the effective rate of one month later of the group D was 92.9% and the effective rate of group P was 38.5%, respectively. The recurrent rate of group D was 7.1% and 34.6% for group P, respectively, for follow-up three months later. The satisfactory rate of group D was higher than that of group P. Conclusion: Ultrasound-guided dry needling and intradermal needling combined with press needling were more effective than only pharmacotherapeutic treatment for PHN mixed with MPS, with lower recurrent rate and higher patient's satisfactory rate.

A retrospective cohort analysis for the risk factors of intraoperative hypotension.

AIM OF THE STUDY: To reveal the risk factors of intraoperative hypotension (IH) and investigate whether IH was corrected in time. METHODS USED TO CONDUCT THE STUDY: This retrospective cohort study included patients undergoing surgeries in one medical centre. We divided all patients into two groups, the IH group and non-IH group. The clinical features of these two groups were compared and the independent risk factors for IH were analysed. RESULTS OF THE STUDY: A total of 5864 non-cardiac surgery patients were included, of which 931 patients had IH diagnose. The independent risk factors of IH include older age, high grade American Society of Anaesthesiologists (ASA) physical status, intrathecal anaesthesia, emergency surgery and medical history of hypertension (P < .01). Among the patients with IH, 44.5% had hypotension lasting between 30 and 120 minutes, and 25.2% had hypotension lasting >120 minutes. Patients with IH are more likely to develop major post-operative complications after surgery (P < .01). CONCLUSIONS: The independent risk factors of IH include older age, high grade ASA physical status, intrathecal anaesthesia, emergency surgery and history of hypertension. Hypotension during surgery is not always effectively treated.

Adaptive Repetitive Control of A Linear Oscillating Motor under Periodic Hydraulic Step Load.

A linear oscillating motor has a direct and efficient linear motion output and is widely used in linear actuation systems. The motor is often applied to compact hybrid electrohydraulic actuators to drive a linear pump. However, the periodic switch of the rectification valve in the pump brings the hydraulic step load to the linear motor, which causes periodic oscillation waveform distortions. The distortion results in the reduction of pumping capacity. The conventional feedback proportional-integral-derivative control is applied to the pump, however, this solution cannot handle the step load as well as resolving nonlinear properties and uncertainties. In this paper, we introduce a nonlinear model to identify periodic hydraulic load. Then, the loads are broken up into a set of simple terms by Fourier series approximation. The uncertain terms and other modeling uncertainties are estimated and compensated by the practical adaptive controller. A robust control term is also developed to handle uncertain nonlinearities. The controller overcame drawbacks of conventional repetitive controllers, such as heavy memory requirements and noise sensitivity. The controller can achieve a prescribed final tracking accuracy under periodic hydraulic load via Lyapunov analysis. Finally, experimental results on the linear oscillating motor-pump are provided for validation of the effectiveness of the scheme.