Experimental research on the impact pressure of tidal bore fronts.

Tidal bore impact can be strong and destructive, placing estuarine infrastructures under great threat. However, there is a lack of research focusing on accurately estimating the impact pressure exerted by tidal bores. Herein new experiments were conducted to investigate the pressure of tidal bore fronts in a glass flume. Through analysis of instantaneous pressure of three forms of tidal bore, it was observed that the pressure fluctuation of weak and strong breaking bore fronts is characterized by impact pressure. The vertical distribution and maximum impact pressure of tidal bore were studied.The maximum impact pressure of breaking bore fronts appeared around 0.46 times height of it. The relationship between relative impact pressure and height of the tidal bore fronts was found to closely follow a normal probability density function. Through nonlinear regression analysis, an empirical equation was derived to calculate impact pressure, which was validated using observation data from the Qiantang River in China. This equation can be utilized to predict the impact pressure of tidal bore fronts and provide valuable support for estuarine engineering design.

Functional Alterations of the Basal Ganglia Are Associated with Voluntary Activation of the Core Stabilizing Muscles in Patients with Chronic Low Back Pain: A Cross-Sectional Study.

Purpose: Deficits in voluntary activation of the core stabilizing muscles are consistently observed in patients with chronic low back pain (CLBP); however, the underlying neural mechanism remains unclear. This cross-sectional study aimed at testing the hypothesis that the impaired voluntary activation of core stabilizing muscles is associated with structural and functional alterations in the basal ganglia, thalamus, and cortex in patients with CLBP. Methods: We obtained structural and resting-state functional magnetic resonance imaging (rs-fMRI) data from 53 patients with CLBP and 67 healthy controls and estimated the alterations in grey matter volume (GMV) and functional and effective connectivity (EC) of regions with altered GMV via whole brain analysis. The voluntary activation of the multifidus (MF) and transversus abdominis (TrA) was evaluated by ultrasound imaging in these patients. Results: Compared with the HCs, they displayed a significant decrease in GMV in the bilateral thalamus and caudate nucleus, a significant increase in GMV in the left middle frontal gyrus, and increased resting-state functional connectivity between the right caudate nucleus and the bilateral precuneus (voxel-level p < 0.005, Gaussian random field-corrected p < 0.05). The patients also showed increased EC from the right caudate nucleus to the bilateral precuneus, which was significantly correlated with voluntary activation of the bilateral MF and TrA (all p < 0.050). Conclusions: Grey matter alterations may be confined to regions responsible for perception, motor control, and emotion regulation in patients with CLBP. The interrupted EC from the basal ganglia to the default mode network might be involved in the impairment of voluntary activation of the core stabilizing muscles.

Does a home-based exercise program play any role in the treatment of knee osteoarthritis? A meta-analysis.

BACKGROUND: Knee-osteoarthritis is a very common joint disorder, affecting about 85% of the population worldwide. The effectiveness of home-based exercises is still debatable, with many studies indicating positive outcomes with few side effects, while others find them of limited utility. OBJECTIVES: To assess the role of home-based exercise (HBE) programs in the treatment of knee osteoarthritis. MATERIAL AND METHODS: Randomized controlled trials were included as per the predefined Population, Intervention, Comparison, Outcomes and Study (PICOS) criteria. Demographic summaries and event data for osteoarthritis therapy in the exercise and control groups were assessed, and comparative efficacy was evaluated using clustered graphs. The RevMan software was used to calculate the odds ratio (OR) and risk ratio of the included studies. The risk of bias was also evaluated and heterogeneity analysis was performed. RESULTS: Fifteen clinical trials performed from 2000 to 2022, with a total of 2922 osteoarthritis patients, were included in the study, according to the chosen inclusion criteria. We observed a reduction in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores but a more marked improvement in clinical symptoms in the exercise group. The Knee Injury and Osteoarthritis Outcome Score (KOOS) increased only in the exercise group and not in the control group. We obtained a pooled OR of 0.59 (95% confidence interval (95% CI): 0.36-0.98), T2 value of 0.88, χ2 value of 185.41, degrees of freedom (df) value of 14, I2 value of 92%, and p-value <0.00001. The overall Z effect was 2.04 with a p-value of 0.04. The pooled risk ratio was 0.81 (95% CI: 0.66-0.99) with a T2 value of 0.14, χ2 value of 191.53, df value of 14, I2 value of 93%, and p-value <0.00001. CONCLUSION: The data from the studies included in this meta-analysis are in favor of the use of HBEs for the treatment of knee osteoarthritis.

The Ultrasonographic Features of Shoulder Pain Patients in a Tertiary Hospital in South China.

METHODS: Patients with shoulder pain were recruited in an outpatient rehabilitation clinic at the Third Affiliated Hospital of Sun Yat-Sen University from January 1, 2017, to June 30, 2018. These shoulder pain patients with or without limitation in joint movement can be included in the study. All of them received musculoskeletal ultrasound scanning. Demographic and imaging data including age, gender, duration of shoulder pain, pain side, and pathologies found by musculoskeletal ultrasound imaging were collected and analyzed. Patients were divided into three groups: <45 years (young group), between 45 and 60 years (middle-aged group), and >60 years (elderly group). The rates of various shoulder pathologies were evaluated and compared between the groups. RESULTS: This study recruited a total of 346 patients with shoulder pain. There were more female (62.1%) than male patients (37.9%), with the largest number of patients in the 45-60 years of age group (40.5%). Forty-eight percent of patients had shoulder pain within a period of 3 months. A total of 380 shoulders were assessed using musculoskeletal ultrasound imaging. The occurrence rate of subacromial disorder (83.8%) was the highest. The rate of supraspinatus tendinopathy, acromioclavicular joint degeneration, and adhesive shoulder capsulitis varied significantly between age groups (P < 0.05). The rate of acromioclavicular joint degeneration was the highest in the elderly group followed by the middle-aged and young groups (P < 0.0167). The rate of supraspinatus tendinopathy and adhesive capsulitis in the middle-aged and elderly groups was significantly higher than that in the young group (P < 0.0167). CONCLUSIONS: Musculoskeletal ultrasound can be a useful imaging tool in making an accurate diagnosis of shoulder pain. The occurrence rates of different shoulder pain pathologies in all age groups were thoroughly calculated in this study. More female and more subcoracoid disorder patients than western countries are attributed to repetitive lifting in daily life and work in this study. Correlations between these pathologies and their associated images can be a solid foundation for the development of artificial intelligence in diagnosing the cause of shoulder pain.

Expanded activated autologous lymphocyte infusions improve outcomes of low- and intermediate-risk childhood acute myeloid leukemia with low level of minimal residual disease.

The presence of minimal residual disease (MRD) is a risk factor for relapse among children with acute myeloid leukemia (AML), and eliminating MRD can usually improve survival rates. To investigate the effect of expanded activated autologous lymphocytes (EAALs) combined with chemotherapy on eliminating MRD and improving survival rates of children with AML, we retrospectively analyzed the results of 115 children with low- or intermediate-risk AML with MRD treated at the Pediatric Hematological Center, Peking University People's Hospital, between January 2010 and January 2016. The patients were assigned to the chemotherapy plus EAAL (combined therapy) group (n = 61) and chemotherapy group (n = 54). The MRD-negativity rates were 95.1% (58/61) in the combined therapy group and 63.0% (34/54) in the chemotherapy group (P < 0.0001) during consolidation treatment. The 5-year event-free survival rate was higher in the combined therapy group than in the chemotherapy group (86.3 ± 4.6% vs. 72.1 ± 6.1%, P = 0.025). No severe adverse event was observed after EAAL infusion. The present study showed that EAAL combined with chemotherapy could improve the MRD-negativity rate and event-free survival rate among children with AML with low level MRD-positive status.

Compressed Symmetric Nested Arrays and Their Application for Direction-of-Arrival Estimation of Near-Field Sources.

In this paper, a new sensor array geometry, called a compressed symmetric nested array (CSNA), is designed to increase the degrees of freedom in the near field. As its name suggests, a CSNA is constructed by getting rid of some elements from two identical nested arrays. The closed form expressions are also presented for the sensor locations and the largest degrees of freedom obtainable as a function of the total number of sensors. Furthermore, a novel DOA estimation method is proposed by utilizing the CSNA in the near field. By employing this new array geometry, our method can identify more sources than sensors. Compared with other existing methods, the proposed method achieves higher resolution because of increased array aperture. Simulation results are demonstrated to verify the effectiveness of the proposed method.

Identification of autotoxic compounds in fibrous roots of Rehmannia (Rehmannia glutinosa Libosch.).

Rehmannia is a medicinal plant in China. Autotoxicity has been reported to be one of the major problems hindering the consecutive monoculture of Rehmannia. However, potential autotoxins produced by the fibrous roots are less known. In this study, the autotoxicity of these fibrous roots was investigated. Four groups of autotoxic compounds from the aqueous extracts of the fibrous roots were isolated and characterized. The ethyl acetate extracts of these water-soluble compounds were further analyzed and separated into five fractions. Among them, the most autotoxic fraction (Fr 3) was subjected to GC/MS analysis, resulting in 32 identified compounds. Based on literature, nine compounds were selected for testing their autotoxic effects on radicle growth. Seven out of the nine compounds were phenolic, which significantly reduced radicle growth in a concentration-dependent manner. The other two were aliphatic compounds that showed a moderate inhibition effect at three concentrations. Concentration of these compounds in soil samples was determined by HPLC. Furthermore, the autotoxic compounds were also found in the top soil of the commercially cultivated Rehmannia fields. It appears that a close link exists between the autotoxic effects on the seedlings and the compounds extracted from fibrous roots of Rehmannia.

[Study of lower extremity muscle function in stroke patients by velocity-encoded phase-contrast magnetic resonance imaging].

OBJECTIVE: To compare the difference of muscle dynamic characteristics for the ankle dorsiflexors and plantarflexors between stroke patients at the chronic stage and healthy controls so as to provide a new method of assessing the in vivo muscle function in patients with hemiplegia. METHODS: From May 2008 to May 2009, 26 stroke patients and 21 age-and gender-matched normal controls were recruited. All subjects were positioned on a scanner table and requested to perform the voluntary movement of ankle flexion-extension. The velocity encoded phase contrast magnetic resonance imaging (VE-PC MRI) provided the images of tibialis anterior muscle (TA), medial head of gastrocnemius muscle (MG) and soleus muscle (SOL) during a movement cycle. By measuring the calf muscle contraction velocity, the balance function was assessed by Berg balance scale (BBS). The correlation between scores of BBS and the mean maximum velocity were compared and analyzed. RESULTS: The peak velocity of TA (1 - 8 phase, 8.900 - 21.120 mm/s vs 12.99 - 34.50 mm/s), MG (12-19phase, 13.60 - 13.28 mm/s vs 25.85 - 18.38 mm/s) and SOL (12 - 16 phase, 18.63 - 33.62 mm/s vs 27.68 - 47.22 mm/s) was lower in the affected side than that in the controls during ankle extension (P < 0.05); During ankle dorsiflexion, the co-contraction index of SOL/TA (2 - 9 phase, 0.81 - 0.82 vs 0.27 - 0.44) and the co-contraction index of GM/TA (2 - 9 phase, 0.73 - 0.58 vs 0.10 - 0.11) was markedly higher in the affected side than the controls. The patient score of BBS was negatively correlated with the mean velocity of TA (r = -0.69, P = 0.001) and GM (r = -0.47, P = 0.01) in the affected side. There was correlation between TA (r = -0.60, P = 0.001) and GM (r = -0.49, P = 0.01) in the unaffected side. CONCLUSION: During the movement of active ankle flexion-extension, the velocities of TA, SOL and MG are lower in the affected side. The co-contraction index is markedly higher in the affected side during ankle dorsiflexion. This in turn leads to a decline of balance function in patients. VE-PC MRI can provide quantitative in vivo measurements of lower extremity muscle function in stroke patients.

[Relationship between the changes of surface electromyographic signal of thigh muscle and balance function in stroke patients].

OBJECTIVE: To explore the relationship between the changes of surface electromyography (sEMG) signal of thigh muscles and balance function in stroke patients during maximum isometric voluntary contraction (MIVC) of knee extension and flexion so as to provide rationales for rehabilitation. METHODS: Twenty-one stroke patients and 18 age- and sex-matched normal controls were recruited for this study. The surface electromyographic signals of of vastus medialis (VM), rectus femoris (RF), vastus lateralis (RL) and biceps femoris (BF) were recorded during MIVC of knee extension and flexion. Root mean square (RMS) and co-contraction ratio (CR) of both groups were compared and analyzed. The balance function was assessed by Berg balance scale (BBS). RESULTS: There were significant differences in RMS of VM, RF, VL and BF of ipsilateral [(136 +/- 63) microV, (107 +/- 24) microV, (154 +/- 19) microV, (91 +/- 63) microV], thigh during knee extension and flexion (P < 0.05). There were significant differences in CR on ipsilateral thigh muscles than the unaffected (43% +/- 13% vs 37% +/- 20%) and controls (43% +/- 13% vs 32% +/- 10%) during knee flexion (P < 0.05). The RMS of RF and BF on ipsilateral thigh was significantly positively correlated with the score of BBS (rRF = 0.53, P = 0.01 vs rBF = 0.51, P = 0.02); The CR of knee extension and flexion on ipsilateral thigh had a significantly negative correlation (CRE = -0.59, P = 0.005 vs. CRF = -0.41, P = 0.046). CONCLUSION: The strength of bilateral thigh muscles decreases in stroke patients. The spasticity of thigh extensor still exists. Besides reducing the spasticity of hemiplegic limb extensor, rehabilitation should also focus upon bilateral thigh muscles, particularly ipsilateral RF and BF strength training to improve the knee joint stability and improve the balance function.