Validation of numerical simulations and experiments on impulse characteristics induced by self-excited oscillation.

The high-frequency pulse flow, equivalent to the natural frequency of rocks, is generated by a self-excited oscillating cavity to achieve resonance rock-breaking. The flow field and oscillating mechanism of the self-excited oscillating cavity were simulated using the large eddy simulation method of Computational Fluid Dynamics (CFD). A field-scale testing apparatus was developed to investigate the impulse characteristics and verify the simulation results. The results show that the fluid at the outlet at the tool is deflected due to the pulse oscillation of the fluid. The size and shape of low-pressure vortices constantly change, leading to periodic changes in fluid impedance within the oscillating cavity. The impulse frequency reaches its highest point when the length-diameter ratio is 0.67. As the length-diameter ratio increases, the tool pressure loss also increases. Regarding the cavity thickness, the impulse frequency of the oscillating cavity initially decreases, then increases, and finally decreases again. Moreover, both the impulse frequency and pressure loss increase with an increase in displacement. The numerical simulation findings align with the experimental results, thus confirming the validity of the theoretical model. This research provides theoretical guidance for the practical application of resonance rock-breaking technology.

Case report: Electroacupuncture for acute pain flare-up of knee osteoarthritis.

Acute pain flare-up of knee osteoarthritis (KOA) is a common disease in orthopedics and is mainly treated with analgesic drugs. Patients usually refuse to take western medicines orally owing to gastrointestinal side effects or unsatisfactory treatment results. We report the case of a 69-year-old woman who had an acute pain flare-up of right KOA induced by long-distance walking. As the patient refused medication, we used electroacupuncture (EA) to relieve her symptoms. EA with a 2-Hz frequency and a 1-2-mA intensity had an analgesic effect on the acute pain flare-up of KOA. After 12 weeks of EA intervention, the bone marrow edema-like lesions (BMLs) improved significantly, as depicted on magnetic resonance imaging of the knee joint. However, more powerful evidence is needed to understand the mechanism of the EA technique that alleviates BMLs of KOA.

Upregulated lncRNA-NEF predicts recurrence and poor treatment outcomes of ankylosing spondylitis.

INTRODUCTION: Osteoporosis is related to lncRNA-neighboring enhancer of FOXA2 (NEF) and inversely correlated to ankylosing spondylitis (AS), implying that lncRNA-NEF might also relate to AS. Thus, the study was carried out to investigate the involvement of lncRNA-NEF in AS. METHODS: The study included 60 AS patients and 60 healthy controls. LncRNA-NEF expression in synovial fluid samples was analyzed by reverse transcription quantitative real-time polymerase chain reaction. Disease activity of the 60 AS patients was determined using the Ankylosing Spondylitis Disease Activity Score (ASDAS) 1-4 and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Western blot was carried out to investigate the effects of lncRNA-NEF on inflammatory factors in human fibroblast-like synovial (HFLS) cells. A 3-year follow-up was performed to analyze the role of lncRNA-NEF in the prediction of the recurrence of AS. RESULTS: Our study observed that lncRNA-NEF expression was upregulated in synovial fluid of AS patients and significantly correlated with the ASDAS 1-4, BASDAI, erythrocyte sedimentation rate (ESR), and C-reactive protein level (p < .05). Treatment with nonsteroidal anti-inflammatory drugs significantly downregulated lncRNA-NEF expression (p < .01). A 3-year follow-up showed that patients with high lncRNA-NEF levels had a high recurrence rate (hazard ratio = 2.266). In addition, lncRNA-NEF was found to regulate the expression of inflammatory factors in HFLS cells. CONCLUSIONS: Therefore, lncRNA-NEF upregulation can predict recurrence and poor treatment outcomes of AS and has a great potential to serve as a predictive biomarker factor for the recurrent AS.

Comparison of Different Insertion Techniques for Lumbosacral Fixation Improvement: A Finite Element Study.

OBJECTIVE: We create a new S1 cortical screw trajectory technique using 3D reconstruction and the finite element (FE) method to provide a more reliable theoretical basis for clinical practices and to advance internal fixation technology for treatment of lumbosacral degenerative diseases. METHODS: This retrospective study included patients (aged from 40 to 70 years) who needed intervertebral fusion surgery between August 2016 and August 2017. Data of patients with lumbosacral lesions was scanned and measured by 64-row spiral CT, and were then transmitted to the GE-AW4.3 post-processing system for 3D reconstruction. The trajectories of the three different screws were simulated by FE software and processed by mimics software to simulate the screw path: traditional PS fixation (Model A); traditional cortical screw (Model B); and new cortical screw (Model C). The CT value of the bone around the screw canal was recorded. Biomechanical effects of the three screws were analyzed and compared. RESULTS: The displacement of flexion and extension, the vertebral body stress of right torsion, and the cage stress of flexion showed no significant differences among the three models (P > 0.05). The results demonstrated that cortical screws exceeded pedicle screws in stability and pullout force. Models B and C showed higher vertebral displacement in left bending (0.41 and 0.31 mm) and right bending (0.58 and 0.40 mm), lower vertebral body stress on extension (48.37 and 38.92 MPa), left bending (0.76 and 0.74 mm) and right bending (0.50 and 0.53 mm), and higher cage stress on left bending (162.19 and 160.63 MPa), right bending (150.02 and 150.05 MPa), left torsion (158.45 and 146.27 MPa) and right torsion (167.33 and 171.15 MPa) (all P < 0.05) compared to model A. Compared to Model B, Model C had higher displacement of left and right torsion, lower pressure in extension and flexion, and lower stress on cages in extension (P < 0.05). CONCLUSION: The new cortical screw insertion method has similar effects to traditional cortical screw fixation. However, it demonstrated advantages in promoting lumbosacral interbody fusion, which protects vessels and nerves.

The Effectiveness of Manual Therapy for Relieving Pain, Stiffness, and Dysfunction in Knee Osteoarthritis: A Systematic Review and Meta-Analysis.

BACKGROUND: Knee osteoarthritis (KOA) is the most common form of arthritis, leading to pain disability in seniors and increased health care utilization. Manual therapy is one widely used physical treatment for KOA. OBJECTIVE: To evaluate the effectiveness and adverse events (AEs) of manual therapy compared to other treatments for relieving pain, stiffness, and physical dysfunction in patients with KOA. STUDY DESIGN: A systematic review and meta-analysis of manual therapy for KOA. METHODS: We searched PubMed, EMBASE, the Cochrane Library, and Chinese databases for relevant randomized controlled trials (RCTs) of manual therapy for patients with KOA from the inception to October 2015 without language restrictions. RCTs compared manual therapy to the placebo or other interventional control with an appropriate description of randomization. Two reviewers independently conducted the search results identification, data extraction, and methodological quality assessment. The methodological quality was assessed by PEDro scale. Pooled data was expressed as standard mean difference (SMD), with 95% confident intervals (CIs) in a random effects model. The meta-analysis of manual therapy for KOA on pain, stiffness, and physical function were conducted. RESULTS: Fourteen studies involving 841 KOA participants compared to other treatments were included. The methodological quality of most included RCTs was poor. The mean PEDro scale score was 6.6. The meta-analyses results showed that manual therapy had statistically significant effects on relieving pain (standardized mean difference, SMD = -0.61, 95% CI -0.95 to -0.28, P = 76%), stiffness (SMD = -0.58, 95% CI -0.95 to -0.21, P = 81%), improving physical function (SMD = -0.49, 95% CI -0.76 to -0.22, P = 65%), and total score (SMD = -0.56, 95% CI -0.78 to -0.35, P = 50%). But in the subgroups, manual therapy did not show significant improvements on stiffness and physical function when treatment duration was less than 4 weeks. And the long-term information for manual therapy was insufficient. LIMITATIONS: The limitations of this systematic review include the paucity of literature and inevitable heterogeneity between included studies. CONCLUSION: The preliminary evidence from our study suggests that manual therapy might be effective and safe for improving pain, stiffness, and physical function in KOA patients and could be treated as complementary and alternative options. However, the evidence may be limited by potential bias and poor methodological quality of included studies. High-quality RCTs with long-term follow-up are warranted to confirm our findings.Key words: Knee osteoarthritis, manual therapy, systematic review.

Harnessing ontology and machine learning for RSO classification.

Classification is an important part of resident space objects (RSOs) identification, which is a main focus of space situational awareness. Owing to the absence of some features caused by the limited and uncertain observations, RSO classification remains a difficult task. In this paper, an ontology for RSO classification named OntoStar is built upon domain knowledge and machine learning rules. Then data describing RSO are represented by OntoStar. A demo shows how an RSO is classified based on OntoStar. It is also shown in the demo that traceable and comprehensible reasons for the classification can be given, hence the classification can be checked and validated. Experiments on WEKA show that ontology-based classification gains a relatively high accuracy and precision for classifying RSOs. When classifying RSOs with imperfect data, ontology-based classification keeps its performances, showing evident advantages over classical machine learning classifiers who either have increases of 5 % at least in FP rate or have decreases of 5 % at least in indexes such as accuracy, precision and recall.

An Inhibitory Role of Osthole in Rat MSCs Osteogenic Differentiation and Proliferation via Wnt/ß-Catenin and Erk1/2-MAPK Pathways.

BACKGROUND/AIMS: Bone marrow-derived mesenchymal stem cells (MSCs) are responsible for new bone formation during adulthood. Accumulating evidences showed that Osthole promotes the osteogenic differentiation in primary osteoblasts. The aim of this study was to investigate whether Osthole exhibits a potential to stimulate the osteogenic differentiation of MSCs and the underlying mechanism. METHODS: MSCs were treated with a gradient concentration of Osthole (6.25 µM, 12.5 µM, and 25 µM). Cell proliferation was assessed by western blotting with the proliferating cell nuclear antigen (PCNA) and Cyclin D1 antibodies, fluorescence activated cell sorting (FACS), and cell counting kit 8 (CCK8). MSCs were cultured in osteogenesis-induced medium for one or two weeks. The osteogenic differentiation of MSCs was estimated by Alkaline Phosphatase (ALP) staining, Alizarin red staining, Calcium influx, and quantitative PCR (qPCR). The underlying mechanism of Osthole-induced osteogenesis was further evaluated by western blotting with antibodies in Wnt/ß-catenin, PI3K/Akt, BMPs/smad1/5/8, and MAPK signaling pathways. RESULTS: Osthole inhibited proliferation of rat MSCs in a dose-dependent manner. Osthole suppressed osteogenic differentiation of rat MSCs by down-regulating the activities of Wnt/ß-catenin and Erk1/2-MAPK signaling. CONCLUSIONS: Osthole inhibits the proliferation and osteogenic differentiation of rat MSCs, which might be mediated through blocking the Wnt/ß-catenin and Erk1/2-MAPK signaling pathways.

[Early efficacies of total knee arthroplasty for knees with severe lateral instability].

OBJECTIVE: To evaluate the outcomes of primary total knee arthroplasty (TKA) in the treatment of knee with severe lateral instability and summarize the essential points of operation and rehabilitation. METHODS: From February 2005 to August 2010, primary TKA was performed in 27 severe lateral unstable knees (25 cases), including 3 males (3 knees) and 22 females (24 knees). Their mean age was 57.8 (37-71) years. And their primary diseases included rheumatoid arthritis (22 knees in 21 cases) and osteoarthritis (5 knees in 4 cases). Thirteen lateral unstable knees were accompanied with 18.08° ± 5.96°(15-35°) varus deformity; in the rest 14 knees, there was medial instability with 20.71° ± 7.03° (15-35°) valgus deformity. Blood loss volume, operative duration and complications were recorded. During the follow-up period, HSS score, knee stability and varus/valgus status were recorded preoperatively, 1, 3, 6, 12 months and then annually postoperatively. RESULTS: AORI type I bone defect was found at the proximal tibia in 18 knees and distal lateral femoral condyle in 10 knees. All defects were reconstructed with cement or autograft. AORI type II bone defects at proximal tibia in 3 knees were reconstructed with metal augmentation. Blood loss during the first 24 hours were (438.9 ± 109.5) (400-700) ml and operative duration (91.1 ± 11.6) (70-110) min. The mean follow-up period was (41.6 ± 10.9) (27-60) months. At the final follow-up, the HSS score increased from (45.8 ± 5.4) to (85.4 ± 4.5) (t = 30.15, P < 0.01) .Five knees in 5 cases had mild postoperative instability. All cases were allowed to walk with knee orthosis for 4-6 weeks. At the end of follow-up, mild lateral instability of 2 knees persisted. One augmented knee had osteolysis beneath metal block. CONCLUSION: TKA for knees with severe lateral instability requires a deep understanding of causes and a rational treatment. Proper handling of bone defects and careful release of lateral soft tissue are two critical points for postoperative knee stability. Wearing knee orthosis during the early postoperative stage may be helpful or residual mild instability.

[Effects of Tuina and Chinese patent drug Shuxuetong injection on deep venous thrombosis and functional rehabilitation after total knee arthroplasty].

OBJECTIVE: To evaluate the efficacy of Tuina and Chinese patent drug Shuxuetong injection in preventing patients undergoing total knee arthroplasty from deep venous thrombosis and in functional rehabilitation. METHODS: A total of 120 patients with diagnosed rheumatoid arthritis in the Department of Orthopaedic Surgery, Shanghai Guanghua Hospital of Integrated Traditional Chinese and Western Medicine in China were enrolled for this study. The patients underwent total knee arthroplasty and were divided into treatment group (n=60) and control group (n=60) after surgery. Patients in the control group received conventional rehabilitation training, including using a continuous passive motion machine and training of muscle contractions of the lower limb. Patients in the treatment group were administered Shuxuetong injection and Tuina based on the conventional rehabilitation training. The course of treatment lasted for 2 weeks. Hospital for Special Surgery (HSS) knee score, rate of deep venous thrombosis and range of motion of the knee joint were evaluated before and after treatment. RESULTS: There was no significant difference in HSS knee score and range of motion as compared before and after treatment in two group (P>0.05). The rate of deep venous thrombosis of the treatment group was 13.33%, which was lower than 20% of the control group (P<0.05). CONCLUSION: Tuina combined with Shuxuetong injection treatment can prevent deep venous thrombosis in patients with rheumatoid arthritis after total knee arthroplasty.