On inverse problems for several coupled PDE systems arising in mathematical biology.

In this paper, we propose and study several inverse problems of identifying/determining unknown coefficients for a class of coupled PDE systems by measuring the average flux data on part of the underlying boundary. In these coupled systems, we mainly consider the non-negative solutions of the coupled equations, which are consistent with realistic settings in biology and ecology. There are several salient features of our inverse problem study: the drastic reduction of the measurement/observation data due to averaging effects, the nonlinear coupling of multiple equations, and the non-negative constraints on the solutions, which pose significant challenges to the inverse problems. We develop a new and effective scheme to tackle the inverse problems and achieve unique identifiability results by properly controlling the injection of different source terms to obtain multiple sets of mean flux data. The approach relies on certain monotonicity properties which are related to the intrinsic structures of the coupled PDE system. We also connect our study to biological applications of practical interest.

Resveratrol Attenuates Ankylosing Spondylitis in Mice by Inhibiting the TLR4/NF-κB/NLRP3 Pathway and Regulating Gut Microbiota.

Ankylosing spondylitis (AS) is an autoimmune disease associated with disturbed gut microbiota. Currently, the treatments and outcomes of AS are not satisfactory. It is reported that resveratrol (RES) is a major phytoalexin with anti-inflammatory, antibacterial and some other pharmacological effects. However, there are no studies on the role of RES in AS. Therefore, this study aimed to explore the effect and mechanism of RES on AS. Proteoglycan and complete freund's adjuvant were used to conduct an AS mouse model, and then the AS mice were gavaged with RES (20 mg/kg and 50 mg/kg) daily for 4 weeks. Subsequently, the effect of RES on AS mice was assessed by detecting disease severity, inflammatory cytokines, NLRP3 inflammasome, TLR4/NF-κB pathway, intestinal mucosal barrier function, intestinal microbial barrier function. The assessment results indicated that RES could significantly relieve progression and severity of AS, inhibit the expression of pro-inflammatory cytokines (tumor necrosis factor-α, interleukin-6, interleukin-17A, interferon-γ), and promote the expression of anti-inflammatory cytokines (interleukin-4). RES intervention caused the inhibition of NLRP3 inflammasome and TLR4/NF-κB pathway. In terms of intestinal barrier function, experimental results found RES increased zonula occludens-1 and occludin expression, and additionally, changed the composition of the gut microbiota by increasing levels of Lactobacillus and Bifidobacterium and reducing levels of Enterococcus faecalis and Escherichia coli. Collectively, RES protects PG-induced AS mice by inhibiting inflammatory responses and TLR4/NF-κB/NLRP3 pathway, restoring intestinal mucosal barrier function, and regulating the composition of the gut microbiota. In other words, RES is a potential candidate for the treatment of AS.

Responsiveness and Predictive Ability of the Chinese Version of the Action Research Arm Test in People with Cerebral Infarction.

PURPOSE: To detect the responsiveness and predictive ability of the Chinese version Action Research Arm Test (C-ARAT) in participants within the first 3 months after cerebral infarction. METHODS: Ninety-seven individuals (75 men, mean age 59.87 ± 10.94 years) with a first cerebral infarction were enrolled in this study. The participants were evaluated by two outcome measures: C-ARAT and the Barthel Activities of Daily Living Index (BI) at five time points: 0D, 3W, 3M, 6M and 1Y after enrolment. The standardised response mean (SRM) and the Wilcoxon signed rank test were used to analyse responsiveness. Predictive validity was determined by using Spearman's rank correlation coefficients. The predicted performance of C-ARAT on activities of daily living (ADLs) was measured by linear regression model. Floor and ceiling effects were estimated by counting the proportion of subjects falling outside the 5% lower or upper boundary, respectively. RESULTS: The C-ARAT showed moderate to large responsiveness in detecting changes over time (SRM = 0.58-0.84). The C-ARAT subscales showed small to large responsiveness (SRM = 0.44-0.90). The C-ARAT at 0D showed moderate to good correlation with the BI scores at 3W, 3M and 6M (ρ = 0.561-0.624, p < 0.001), and exhibited fair correlation with the BI score 1Y after enrolment (ρ = 0.384, p < 0.05). C-ARAT was a good predictor (adjusted R 2 = 0.185-0.249) of BI within 3M follow-up. The C-ARAT total score showed a notable floor effect at 0D and 3W and a notable ceiling effect at 3M, 6M and 1Y. CONCLUSION: The results of this study support the use of the C-ARAT as a measurement of upper extremity function in individuals with a first cerebral infarction.

Optimizing the Microstructure and Corrosion Resistance of BDD Coating to Improve the Service Life of Ti/BDD Coated Electrode.

The short service life of the Ti/BDD coated electrode is the main reason that limits its practical use. In this paper, the effect of structural change on the service life was studied using Ti/BDD coated electrodes prepared with the arc plasma chemical vapor deposition (CVD) method. It was found that the microstructural defects and corrosion resistance of BDD coatings were the main factors affecting the electrode service life. By optimizing the process parameters in different deposition stages, reducing the structural defects and improving the corrosion resistance of the BDD coating were conducted successfully, which increased the service life of the Ti/BDD coated electrodes significantly. The lifetime of the Ti/BDD samples increased from 360 h to 655 h under the electrolysis condition with a current density of 0.5 A/cm2, with an increase of 82%.

Translation and Initial Validation of the Chinese Version of the Action Research Arm Test in People with Stroke.

PURPOSE: This study aimed to translate the English version of the Action Research Arm Test (ARAT) into Chinese and to evaluate the initial validation of the Chinese version (C-ARAT) in patients with a first stroke. METHODS: An expert group translated the original ARAT from English into Chinese using a forward-backward procedure. Forty-four patients (36 men and 8 women) aged 22-80 years with a first stroke were enrolled in this study. The participants were evaluated using 3 stroke-specific outcome measures: C-ARAT, the upper extremity section of the Fugl-Meyer assessment (UE-FMA), and the Wolf Motor Function Test (WMFT). Internal consistency was analysed using Cronbach's α coefficients and item-scale correlations. Concurrent validity was determined using Spearman's rank correlation coefficients. Floor and ceiling effects were considered to be present when more than 20% of patients fell outside the preliminarily set lower or upper boundary, respectively. RESULTS: The C-ARAT items yielded excellent internal consistency, with a Cronbach's α of 0.98 (p < 0.001) and item-total correlations ranging from 0.727 to 0.948 (p < 0.001). The C-ARAT exhibited good-to-excellent correlations with the UE-FMA and WMFT functional ability (WMFT-FA) scores, with respective ρ values of 0.824 and 0.852 (p < 0.001), and an excellent negative correlation with the WMFT performance time (WMFT-time), with a ρ value of -0.940 (p < 0.001). The C-ARAT subscales generally exhibited good-to-excellent correlations with stroke-specific assessments, with ρ values ranging from 0.773 to 0.927 (p < 0.001). However, the gross subscale exhibited moderate-to-good correlations with the UE-FMA and WMFT-FA scores, with respective ρ values of 0.665 and 0.720 (p < 0.001). No significant floor effect was observed, and a significant ceiling effect was observed only on the WMFT-time. CONCLUSIONS: The C-ARAT demonstrated excellent internal consistency and good-to-excellent concurrent validity. This test could be used to evaluate upper extremity function in stroke patients without cognitive impairment.

The Crucial Changes of Sit-to-Stand Phases in Subacute Stroke Survivors Identified by Movement Decomposition Analysis.

OBJECTIVE: The aim of this study was to detect the key changes during sit-to-stand (STS) movement cycle in hemiparetic stroke survivors using a five-phase kinematic and kinetic analysis. METHODS: Twenty-five subacute stroke survivors and 17 age-matched healthy adults participated in this study. The kinematic and kinetic parameters during STS cycle were measured using three-dimensional motion analysis system with force plates. The five standard phases of STS cycle were identified by six timing transitional points. RESULTS: Longer total time as well as larger changes were observed at the initial phase (phase I, 0.76 ± 0.62 VS 0.43 ± 0.09 s; p = 0.049) and at the end of hip and knee extension phase (phase IV, 0.93 ± 0.41 VS 0.63 ± 0.14 s; p = 0.008) in the stroke group than healthy group. Time to maximal knee joint moment was significantly delayed in the stroke group than in the control group (1.14 ± 1.06 VS 0.60 ± 0.09 s, p < 0.001). The maximal hip flexion was lower during the rising phase from seated position on the affected side in the stroke group than in the control group (84.22° ± 11.64°VS 94.11° ± 9.40°; p = 0.022). Ground reaction force was lower (4.61 ± 0.73 VS 5.85 ± 0.53 N, p < 0.001) in the affected side of the stroke group than in the control group. In addition, knee joint flexion was significantly lower at just-standing phase (T4) and at end point (T5) (5.12° ± 5.25° VS 8.21° ± 7.28°, p = 0.039; 0.03° ± 5.41° VS 3.07° ± 6.71°, p = 0.042) on the affected side than the unaffected side. Crucial decrease of knee joint moment at abrupt transitory (T2) and the maximal moment was also observed on the affected side in comparison with the unaffected side (0.39 ± 0.29 VS 0.77 ± 0.25 Nm/kg, p < 0.001; 0.42 ± 0.38 VS 0.82 ± 0.24 Nm/kg, p < 0.001). CONCLUSION: The findings of movement decomposition analysis provided useful information to clinical evaluation of STS performance, and may potentially contribute to the design of rehabilitation intervention program for optimum functional recovery of STS after stroke.

Effect of Virtual Reality on Postural and Balance Control in Patients with Stroke: A Systematic Literature Review.

Objective. To critically evaluate the studies that were conducted over the past 10 years and to assess the impact of virtual reality on static and dynamic balance control in the stroke population. Method. A systematic review of randomized controlled trials published between January 2006 and December 2015 was conducted. Databases searched were PubMed, Scopus, and Web of Science. Studies must have involved adult patients with stroke during acute, subacute, or chronic phase. All included studies must have assessed the impact of virtual reality programme on either static or dynamic balance ability and compared it with a control group. The Physiotherapy Evidence Database (PEDro) scale was used to assess the methodological quality of the included studies. Results. Nine studies were included in this systematic review. The PEDro scores ranged from 4 to 9 points. All studies, except one, showed significant improvement in static or dynamic balance outcomes group. Conclusions. This review provided moderate evidence to support the fact that virtual reality training is an effective adjunct to standard rehabilitation programme to improve balance for patients with chronic stroke. The effect of VR training in balance recovery is less clear in patients with acute or subacute stroke. Further research is required to investigate the optimum training intensity and frequency to achieve the desired outcome.

[Effects of ankle-foot orthosis on gait stability and balance control in patients with hemiparetic stroke].

OBJECTIVE: To quantitatively analyze the effects of ankle-foot orthosis (AFO) on gait stability and explore its use for walking capacity, gait stability and balance control in post-stroke patients. METHODS: A total of 25 inpatients with prior chronic hemiparesis from stroke who could walk at least 10 meters without assistance were recruited. The maximal walking speed and gait asymmetry index were examined by a motion analysis system. Functional balance was assessed by the Functional Ambulation Categories, Berg Balance Scale and Five-Times-Sit-to-Stand Test. RESULTS: AFO had positive effects on the hemiplegic gait parameters of improving walking speed, gait stability and functional balance (P < 0.01). Pair wise comparisons suggested that there were significant differences in the maximal walking speed, Functional Ambulation Categories and gait asymmetry index after an immediate use of AFO (P < 0.05). At Week 4, there were significant differences in the parameters of walking speed, gait asymmetry index and functional balance control (P < 0.01). CONCLUSION: The use of AFO may compensate the instability of gait and balance. Functional tests improve significantly with orthosis.

[A randomized controlled study on warming needle moxibustion for treatment of knee osteoarthritis].

OBJECTIVE: To assess the short-term and long-term therapeutic effect of warming needle moxibustion for treatment of knee osteoarthritis. METHODS: Ninety cases were randomly divided into a warming needle moxibustion group, a western medicine group and a waiting group, 30 cases in each group. The warming needle moxibustion group was treated with warming needle moxibustion on Xuehai (SP 10), Dubi (ST 35) and Zusanli (ST 36), etc.; the western medicine group was treated with oral administration of Ibuprofen sustained release capsule; the waiting group did not receive any treatment. Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and Chinese version of SF-16 were used to assess the therapeutic effect before treatment, after treatment and 10 weeks after treatment. RESULTS: After treatment for 2 weeks, the total effective rate was 86.7% in the warming needle moxibustion group, 90.0% in the western medicine group, and 60.0% in the waiting group, both the warming needle moxibustion group and the western medicine group being significantly better than the waiting group (both P<0.05) and with no significant difference between the warming needle moxibustion group and the western medicine group (P>0.05); 10 weeks after treatment, the total effective rate of 83.3% in the warming needle moxibustion group was better than that of 60.0% in the western medicine group (P<0.05). There were no significant differences in comparison of WOMAC and SF-16 scores after treatment between the warming needle moxibustion group and the western medicine group, and the warming needle moxibustion group in improvement of these scores was superior to the western medicine group (P<0.01, P<0.05). CONCLUSION: The therapy of warming needle moxibustion is effective for treatment of knee osteoarthritis, and the short-term therapeutic effect is same as that of oral administration of Ibuprofen and the long-term therapeutic effect is better than that of Ibuprofen.