Carbon fiber reinforced poly ether ether ketone (CF/PEEK) composite possesses excellent biocompatible, biomechanical and bio-tribological properties. It is one of the most promising implant materials for artificial joint. Many factors influence the bio-tribological properties of CF/PEEK composites. In this paper, the authors reviewed on the biotribology research progress of CF/PEEK composites. The influences of various factors such as lubricant, reinforcement surface modification, functional particles, friction counterpart and friction motion modes on the bio-tribological properties of CF/PEEK composites are discussed. Based on the recent research, the authors suggest that the further research should be focused on the synergistic effect of multiple factors on the wear and lubrication mechanism of CF/PEEK.
Speech enhancement methods based on microphone array adopt many microphones to record speech signal simultaneously. As spatial information is increased, these methods can increase speech recognition for cochlear implant in noisy environment. Due to the size limitation, the number of microphones used in the cochlear implant cannot be too large, which limits the design of microphone array beamforming. To balance the size limitation of cochlear implant and the spatial orientation information of the signal acquisition, we propose a speech enhancement and beamforming algorithm based on dual thin uni-directional / omni-directional microphone pairs (TP) in this paper. Each TP microphone contains two sound tubes for signal acquisition, which increase the overall spatial orientation information. In this paper, we discuss the beamforming characteristics with different gain vectors and the influence of the inter-microphone distance on beamforming, which provides valuable theoretical analysis and engineering parameters for the application of dual microphone speech enhancement technology in cochlear implants.
The measurement of network is one of the important researches in resolving neuronal population information processing mechanism using complex network theory. For the quantitative measurement problem of functional neural network, the relation between the measure indexes, i.e. the clustering coefficient, the global efficiency, the characteristic path length and the transitivity, and the network topology was analyzed. Then, the spike-based functional neural network was established and the simulation results showed that the measured network could represent the original neural connections among neurons. On the basis of the former work, the coding of functional neural network in nidopallium caudolaterale (NCL) about pigeon's motion behaviors was studied. We found that the NCL functional neural network effectively encoded the motion behaviors of the pigeon, and there were significant differences in four indexes among the left-turning, the forward and the right-turning. Overall, the establishment method of spike-based functional neural network is available and it is an effective tool to parse the brain information processing mechanism.
Objectives To observe the distribution of enlarged perivascular spaces (EPVSs) in acute ischemic stroke, and determine the factors that influence basal ganglia and centrum semiovale EPVSs. Methods We prospectively registered consecutive patients with acute ischemic stroke at the neurological wards of Jianyang Municipal People’s Hospital and West China Hospital of Sichuan University from February 1st to November 1st, 2014. Patients with ischemic stroke within 14 days of symptom onset, having magnetic resonance image (MRI) scan were included. Basal ganglia and centrum semiovale EPVSs, white matter hyperintensity, cerebral atrophy and lacunar infraction were rated using validated scales by reading MRI. Clinical information was obtained using standardized forms. The distribution of EPVSs was observed and analyzed. The evalution of EPVSs was analyzed in relation to age, vascular risk factor, cerebral atrophy, white matter hyperintensity, lacunar infraction, etc, by using univariate and multivariate logistical regression to evaluate the influencing factors for basal ganglia and centrum semiovale EPVSs. Results A total of 170 patients with acute ischemic stroke within 14 days from onset were included; in whom, 97.6% had EPVSs in basal ganglia and all had EPVSs in centrum semiovale. The most common scores of basal ganglia EPVSs were 1 point and 2 points. The most common scores of centrum semiovale EPVSs were 2 and 3 points. In logistic regression, age [odds ratio (OR)=1.043, 95% confidence interval (CI) (1.015, 1.071), P=0.002], periventricular white matter hyperintensity [OR=4.203, 95%CI (1.525, 11.583), P=0.006] and hypertension [OR=3.965, 95%CI (1.927, 8.157), P<0.001] were independently associated with increased severity of basal ganglia EPVSs. Only periventricular white matter hyperintensity [OR=2.248, 95%CI (1.054, 4.795), P=0.036] was independently associated with increased severity of centrum semiovale EPVSs in logistic regression. Conclusions EPVSs are common in ischemic stroke. There is a lower prevalence of EPVS in the basal ganglia compared with the centrum semiovale. Compared with centrum semiovale EPVSs, basal ganglia EPVSs are more associated with hypertensive cerebral small vessel disease, which may be a marker for hypertensive cerebral small vessel disease.
【摘要】 目的 观察机械通气对黏蛋白（mucin，MUC）-5AC表达的影响及复方川贝精片的干预作用。 方法 新西兰兔25只，6个月龄，雄性；随机分为对照组、机械通气12 h组及复方川贝精片低、中、高剂量组。收集支气管灌洗液，分别采用实时荧光定量聚合酶链式反应法和酶联免疫吸附试验检测支气管灌洗液中p38 MAPK mRNA，MUC-5AC蛋白和mRNA的表达。 结果 机械通气能增强MUC-5AC的分泌（Plt;0.05）；加用复方川贝精片能降低机械通气后MUC-5AC蛋白和mRNA的表达（Plt;0.05）；复方川贝精片中、高剂量组与低剂量组比较，能降低机械通气后MUC-5AC蛋白和mRNA的表达（Plt;0.05）。 结论 机械通气能促进支气管黏膜上皮细胞分泌MUC-5AC，复方川贝精片能抑制机械通气所致MUC-5AC表达升高，其机制可能与其抑制p38 MAPK表达有关。【Abstract】 Objective To observe the effect of mechanical ventilation by breathing machine on the expression of mucin (MUC-5AC) and the interfering effect of compound tablet of fritillary bulb. Methods New Zealand Rabbits were randomly divided into control group, twelve-hour mechanical ventilation group, and low, medium and high-dose compound tablet of fritillary bulb group. Contents of p38 MAPK mRNA, MUC-5AC mRNA and protein in bronchial irrigating solution were detected by realtime RT-PCR and ELISA methods. Results Mechanical ventilation could increase the expression of MUC-5AC in bronchial irrigating solution (Plt;0.05). Compound tablet of fritillary bulb could decrease the expression of MUC-5AC mRNA and protein after mechanical ventilation (Plt;0.05). Compared with low-dose compound tablet of fritillary bulb group, the expression of MUC-5AC mRNA and protein was lower for the high and medium-dose groups (Plt;0.05). Conclusions Mechanical ventilation can promote the expression of MUC-5AC in bronchial endothelial cells, which can be suppressed by compound tablet of fritillary bulb. This may be due to the suppression effect of p38 MAPK expression.
ObjectiveTo investigate the clinical signification of plasma interleukin-17 (IL-17) 1evel in patients with acute respiratory distress syndrome (ARDS).MethodsForty-five adult ARDS patients and 22 healthy controls were enrolled in this study. The plasma cytokine levels of IL-17, IL-6 and IL-10 were measured by enzyme linked immunosorbent assay. Meanwhile, the baseline data of demographic and clinical tests including oxygenation index, procalcitonin and brain natriuretic peprtide were collected, the acute physiological and chronic health Ⅱ (APACHEⅡ) score and sequential organ failure assessment (SOFA) score were recorded. The main outcome was defined as hospital mortality within 28-day follow-up.ResultsThe plasma concentration of IL-17, IL-6 were higher in the ARDS patients (P<0.05) compared with the controls and the mean levels of IL-17, IL-6 and the APACHEⅡ score and the SOFA score in the non-survivors was higher than those in the survivors (P<0.05). In particular, there was a significant correlation between the plasma levels of IL-17 and IL-6 (P<0.05). Logistic regression and COX multivariate survival analysis suggested that age and SOFA score may be prognostic factors for ARDS.ConclusionsThe plasma concentration of IL-17 is significantly increased in ARDS patients, and its expression is linearly related to the proinflammatory factor IL-6. Both are important inflammatory markers in the acute phase of ARDS and may be important disease severity and prognostic indicators in addition to age and SOFA score.
Objective To summarize the application of double valve ring enlargement combined with mitral Chimney technique (Chimney Commando) in the secondary valve replacement and to analyze the efficacy in the near and medium term. Methods Patients who underwent the secondary aortic valve and mitral valve (double valve) replacement by Chimney Commando in Wuhan Asia Heart Hospital from 2019 to 2022 were included, and their clinical data were retrospectively collected to analyze the safety and feasibility of this procedure in secondary valve replacement of small aortic root patients. Results A total of 49 patients (44 females and 5 males) were included. The body surface area was 1.64±0.17 m2. The time from the first operation was 13.10±5.90 years. Except for 4 patients whose first operation was valvuloplasty, the remaining 45 patients were all patients after valve replacement, 41 patients of double valves replacement, including 39 patients with mechanical valve and 2 patients with biological valve. The majority of the aortic valves were St.Jude regent 19 mm or St.Jude regent 21 mm, accounting for 30.61% and 34.69%, respectively. The mitral valves were predominantly St.Jude 25 mm mechanical valves, making up 65.31%. All patients underwent Chimney Commando double valve ring enlargement, and the mean time of aortic occlusion was 154.00±45.40 min. The mean size of the aortic valve was 23.90±1.40 mm and that of the mitral valve was 28.20±1.20 mm, and the transvalvular pressure difference across the aortic valve was 20.16±5.76 mm Hg at 6 months postoperatively. There was one death during hospitalization due to multi-organ failure. The follow-up time ranged from 1 to 24 months with a median time of 8 months. Two patients were implanted with permanent pacemakers during the follow-up period and 1 patient died due to massive stroke and malignant arrhythmia. Conclusion Chimney Commando is safe and effective in patients with secondary double valve replacement, and the postoperative prosthetic valves have good hemodynamics, and can achieve good clinical results in the near and medium term.
Objective To analyze the short-term effectiveness of repairing musculus extensor carpi radialis brevis (ECRB) and extensor digitorum communis (EDC) tendon using suture anchor after debridement of extensor tendon insertion for recalcitrant lateral epicondylitis. Methods Between March 2009 and May 2011, 10 patients (10 elbows) with recalcitrant lateral epicondylitis received repair of the ECRB and EDC tendon to the lateral epicondyle using a single suture anchor after debridement of extensor tendon insertion. There were 6 males and 4 females with an average age of 45.4 years (range, 36-57 years). The dominant elbow was involved in 8 patients and nondominant elbow in 2 patients; there were 4 manual workers and 6 ordinary workers. The disease duration ranged from 8 to 24 months (mean, 12.3 months). All patients had epicondylus lateralis humeri pain, local swelling and tenderness, and positive Mill sign. The average elbow range of motion (ROM) was 11.3°(range, 0-30°) in extension and was 132.5°(range, 120-145°) in flexion. Preoperative MRI showed external humeral epicondylitis in all patients. ResultsPrimary wound healing was obtained in all patients without complications of infection, leakage of joint fluid, and stiffness of elbow. Ten patients were followed up 4 to 23 months with an average of 12 months (more than 12 months in 7 cases). The time to return to work was (3.75 ± 0.95) months for manual workers and was (2.91 ± 0.20) months for ordinary workers, showing no significant difference (t=1.715, P=0.180). Compared with preoperation, the mean visual analogue scale (VAS) score significantly decreased (P lt; 0.05), and Mayo score and the grip strength of dominant and nondominant significantly increased (P lt; 0.05), but no significant difference was found when compared with non-surgical side at last follow-up (P gt; 0.05). At last follow-up, the average ROM was —1.5° (range, 0-—10°) in extension and was 150.5°(range, 140-160°) in flexion. ConclusionTo suture anchor for repairing the ECRB and EDC after debridement is a satisfactory procedure to treat recalcitrant lateral epicondylitis. It can effectively prevent loss of the forearm extensor strength, relieve the pain, recover the grip strength, and obtain good results.