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Intervertebral disc degeneration (IDD) is the cause of low back pain (LBP), and recent research has suggested that inflammatory cytokines play a significant role in this process. Maslinic acid (MA), a natural compound found in olive plants ( Olea europaea), has anti-inflammatory properties, but its potential for treating IDD is unclear. The current study aims to investigate the effects of MA on TNFα-induced IDD in vitro and in other in vivo models. Our findings suggest that MA ameliorates the imbalance of the extracellular matrix (ECM) and mitigates senescence by upregulating aggrecan and collagen II levels as well as downregulating MMP and ADAMTS levels in nucleus pulposus cells (NPCs). It can also impede the progression of IDD in rats. We further find that MA significantly affects the PI3K/AKT and NF-κB pathways in TNFα-induced NPCs determined by RNA-seq and experimental verification, while the AKT agonist Sc-79 eliminates these signaling cascades. Furthermore, molecular docking simulation shows that MA directly binds to PI3K. Dysfunction of the PI3K/AKT pathway and ECM metabolism has also been confirmed in clinical specimens of degenerated nucleus pulposus. This study demonstrates that MA may hold promise as a therapeutic agent for alleviating ECM metabolism disorders and senescence to treat IDD.
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Degeneração do Disco Intervertebral , NF-kappa B , Núcleo Pulposo , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Ratos Sprague-Dawley , Transdução de Sinais , Triterpenos , Degeneração do Disco Intervertebral/metabolismo , Degeneração do Disco Intervertebral/tratamento farmacológico , Degeneração do Disco Intervertebral/patologia , Animais , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , NF-kappa B/metabolismo , Núcleo Pulposo/metabolismo , Núcleo Pulposo/efeitos dos fármacos , Núcleo Pulposo/patologia , Masculino , Triterpenos/farmacologia , Ratos , Humanos , Simulação de Acoplamento Molecular , Fator de Necrose Tumoral alfa/metabolismo , Matriz Extracelular/metabolismo , Matriz Extracelular/efeitos dos fármacos , Feminino , Células Cultivadas , Ácido Oleanólico/análogos & derivadosRESUMO
Both inside data centers (DCs) and in short optical links between data centers (DC campuses), intensity-modulation and direct-detection (IMDD) systems using four-level pulse amplitude modulation (PAM4) will dominate this decade due to low transceiver price and power consumption. The next DC transceiver generation based on 100 Gbaud PAM4 will require advanced digital signal processing (DSP) algorithms and more powerful forward error correction (FEC) codes. Because of bandwidth limitations, the conventional DC DSP based on a few-tap linear feed-forward equalizer (FFE) is likely to be upgraded to more complex but still low-complexity Volterra equalizers followed by a noise whitening filter and either a maximum likelihood sequence estimation (MLSE) or a maximum a posteriori probability (MAP) algorithm. However, stringent power consumption and latency requirements may limit the use of complex algorithms such as decision feedback equalizer (DFE) or MLSE/MAP in DC networks (DCN). In this paper, we introduce a low-complexity, low-latency algorithm based on a feedforward structure, yielding a performance between DFE and MLSE. We call the novel equalization algorithm probabilistic noise cancellation (PNC), since it weights noise patterns based on their probabilities in the presence of bandwidth limitations. The probabilistic weighting is efficiently exploited in correcting correlated errors caused by noise coloring in the FFE.
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BACKGROUND CONTEXT: Facet joint osteoarthritis (FJOA) is associated with lumbar disc degeneration and has a significant role in the development of lumbar spinal stenosis (LSS). The relationship between various radiographic parameters and the grade of FJOA is not well understood. PURPOSE: To explore radiographical parameters associated with FJOA in LSS without lumbar dynamic instability. STUDY DESIGN: Retrospective study analysis. PATIENT SAMPLE: A total of 122 patients diagnosed with LSS who visited our hospital between January 2015 and July 2022. OUTCOME MEASURES: We evaluated radiographic parameters of patients at L4-5 including lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), grades of FJOA, facet joint orientation (FO), facet joint tropism (FT), intervertebral height index (IHI) and the relative cross-sectional area (RCSA) of paraspinal muscles. METHODS: Patients diagnosed with LSS between January 2015 and July 2022 were enrolled. Demographic characteristics and radiographic parameters were collected. Spinopelvic parameters were measured through the preoperative lateral image of the whole spine, including LL, PI, pelvic tilt, and sacral slope. Lumbar computed tomography scan and magnetic resonance imaging were collected to measure the FO, FT, IHI, and the RCSA of paraspinal muscles respectively. Patients were divided into three groups according to the severity of FJOA graded by the Weishaupt classification: grade 0 and grade 1 were group A, grade 2 were group B, and grade 3 were group C. All variables were compared among the three groups, while the relationship between parameters and grades of FJOA were also analyzed. RESULTS: A total of 122 patients were included. PI was significantly greater in group C compared to group A (p = 0.025) and group B (p=0.022). FT was significantly greater in group C compared to group A (p<.001) and group B (p<.001). The RCSA of multifidus in group A were significantly greater than that in group B (p=0.02) and C (p=0.002). Additionally, FO in group C were significantly lower than group A (p<.001) and group B (p=0.028). The IHI in group C was significantly lower than group A (p=0.017). The correlation analysis indicated that grades of FJOA was positively related to Age, BMI (body mass index), PI, LL and FT, while negatively related to IHI, FO, RCSA of multifidus and RCSA of psoas major. Furthermore, the logistics regression showed that FT, PI, and IHI were important influence factors for FJOA. CONCLUSIONS: The current study confirmed that FT, PI and IHI were significantly associated with grades of FJOA at L4-5. Additionally, longitudinal studies are needed to understand the causal relationship between these parameters and FJOA.
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Lordose , Osteoartrite , Estenose Espinal , Articulação Zigapofisária , Humanos , Articulação Zigapofisária/diagnóstico por imagem , Articulação Zigapofisária/patologia , Estenose Espinal/diagnóstico por imagem , Estenose Espinal/patologia , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Estudos Retrospectivos , Lordose/patologia , Tropismo , Osteoartrite/epidemiologiaRESUMO
Cartilage is derived from the chondrogenic differentiation of stem cells, for which the regulatory mechanism has not been fully elucidated. N6-methyladenosine (m6A) messenger RNA (mRNA) methylation is the most common posttranscriptional modification in eukaryotic mRNAs and is mediated by m6A regulators. However, whether m6A regulators play roles in chondrogenic differentiation is unknown. Herein, we aim to determine the role of a main m6A reader protein, YTH N6-methyladenosine RNA binding protein 1 (YTHDF1), in chondrogenic differentiation regulation. Western blotting (WB) assays found that the expression of YTHDF1 increased during chondrogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). The results of quantitative polymerase chain reaction, WB, immunohistochemistry, and Alcian blue staining revealed that overexpression of YTHDF1 increased cartilage matrix synthesis and the expression of chondrogenic markers when hBMSCs, ATDC5 cells, or C3H10T1/2 cells were induced to undergo chondrogenesis. Conversely, chondrogenesis was clearly inhibited when YTHDF1 was knocked down in hBMSCs, ATDC5 cells, or C3H10T1/2 cells. Further RNA sequencing and molecular biology experiments found that YTHDF1 activated the Wnt/ß-catenin signaling pathway during chondrogenic differentiation. Finally, the effects of overexpression and knockdown of YTHDF1 on chondrogenic differentiation were reversed by inhibiting or activating ß-catenin activity. Therefore, we demonstrated that YTDHF1 promoted chondrogenic differentiation through activation of the Wnt/ß-catenin signaling pathway.
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Células-Tronco Mesenquimais , Via de Sinalização Wnt , Humanos , Via de Sinalização Wnt/genética , Condrogênese/genética , Diferenciação Celular , beta Catenina/metabolismo , Células-Tronco/metabolismo , RNA Mensageiro/metabolismo , Células Cultivadas , Proteínas de Ligação a RNA/metabolismoRESUMO
The purpose of this paper is to investigate the fatigue properties of C17200 alloy under the condition of quenching aging heat treatment at high temperatures, and to provide a design reference for its application in a certain temperature range. For this purpose, the tensile and rotary bending fatigue (RBF) tests were carried out at different temperatures (25 °C, 150 °C, 350 °C, and 450 °C). The tensile strength was obtained, and relationships between the applied bending stress levels and the number of fatigue fracture cycles were fitted to the stress-life (S-N) curves, and the related equations were determined. The fractured surfaces were observed and analyzed by a scanning electron microscopy (SEM). The results show that the RBF fatigue performance of C17200 alloy specimens is decreased with the increase in test temperature. When the temperature is below 350 °C, the performance degradation amplitudes of mechanical properties and RBF fatigue resistance are at a low level. However, compared to the RBF fatigue strength of 1 × 107 cycles at 25 °C, it is decreased by 38.4% when the temperature reaches 450 °C. It is found that the fatigue failure type of C17200 alloy belongs to surface defect initiation. Below 350 °C, the surface roughness of the fatigue fracture is higher, which is similar to the brittle fracture, so the boundary of the fracture regions is not obvious. At 450 °C, due to the further increase in temperature, oxidation occurs on the fracture surface, and the boundary of typical fatigue zone is obvious.
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In this paper, the responses of machined surface roughness and milling tool cutting forces under the different milling processing parameters (cutting speed v, feed rate f, and axial cutting depth ap) are experimentally investigated to meet the increasing requirements for the mechanical machining of T2 pure copper. The effects of different milling processing parameters on cutting force and tool displacement acceleration are studied based on orthogonal and single-factor milling experiments. The three-dimensional morphologies of the workpieces are observed, and a white-light topography instrument measures the surface roughness. The results show that the degree of influence on Sa (surface arithmetic mean deviation) and Sq (surface root mean square deviation) from high to low level is the v, the f, and the ap. When v = 600 m/min, ap = 0.5 mm, f = 0.1 mm/r, Sa and Sq are 1.80 µm and 2.25 µm, respectively. The cutting forces in the three directions negatively correlate with increased cutting speed; when v = 600 m/min, Fx reaches its lowest value. In contrast, an increase in the feed rate and the axial cutting depth significantly increases Fx. The tool displacement acceleration amplitudes demonstrate a positive relationship. Variation of the tool displacement acceleration states leads to the different microstructure of the machined surfaces. Therefore, selecting the appropriate milling processing parameters has a positive effect on reducing the tool displacement acceleration, improving the machined surface quality of T2 pure copper, and extending the tool's life. The optimal milling processing parameters in this paper are the v = 600 m/min, ap = 0.5 mm, and f = 0.1 mm/r.
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STUDY DESIGN: A combined retrospective and prospective analysis on the therapeutic effect of physiotherapeutic scoliosis-specific exercise (PSSE) in mild juvenile idiopathic scoliosis (JIS) patients. BACKGROUND: At present, patients with mild JIS are generally treated by observation without any interventional treatment. This study analyzed the effects of PSSE on mild JIS, which provided a new approach for the treatment of JIS. METHOD: A total of 52 patients with mild JIS (Cobb angle 10-19°), aged 4-9 years, self-selected into an observation group and a PSSE group. Patients performed the corrective posture exercises daily based on the Scientific Exercise Approach to Scoliosis (SEAS) to the best of their ability, and performed the over-corrective training based on Schroth methods for 30 min each day. Before and one year after the treatment, the Cobb angle and the angle of trunk rotation (ATR) were evaluated, and the results were compared between the two groups. RESULTS: After one year of treatment, the Cobb angle in the PSSE group decreased from 15.0(11.0-17.0)° to 5.0(2.0-12.0)°(p ≤ 0.001), while the Cobb angle in the observation group increased from 13.5(11.0-17.3)° to 16.0(10.8-20.0)° (p = 0.010). The ATR in the PSSE group decreased from 5.0(2.0-7.0)° to 3.0(2.0-4.0)° (p = 0.009), while the change of ATR in the observation group was not significant. Compared with the observation group, 69.57% of patients in PSSE group had a decreased Cobb angle of more than 5 degrees, which was statistically significant(p ≤ 0.001). CONCLUSION: For mild JIS, PSSE decreased the Cobb angle and ATR.
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Escoliose , Terapia por Exercício/métodos , Humanos , Modalidades de Fisioterapia , Estudos Retrospectivos , Escoliose/diagnóstico por imagem , Escoliose/terapia , Resultado do TratamentoRESUMO
BACKGROUND: The treatment of severe and rigid scoliosis is challenging. We developed a surgical strategy for severe and rigid scoliosis since 2014. This study aimed to retrospectively analyze the safety and efficacy of apical region correction and global balance with 3 rods as a surgical strategy for the treatment of severe and rigid scoliosis. METHODS: A retrospective study was performed for patients with severe and rigid scoliosis who underwent one-stage posterior corrective operation using the apical region correction and global balance with 3 rods surgical strategy between February 2014 and April 2020. The inclusion criteria were as follows: [1] Cobb angle > 90°; [2] flexibility < 30%; [3] a minimum 2-year follow-up. Patients were excluded if they had a history of traction or spinal surgery. Coronal and sagittal parameters, including Cobb angle, flexibility, apex vertebra translation, trunk shift (TS), thoracic kyphosis, lumbar lordosis, and sagittal vertical axis (SVA) were measured preoperatively, postoperatively and at the final follow-up. The Scoliosis Research Society 22-item questionnaire was administered preoperatively and at the final follow-up. During the operation, one slightly-bent short rod was placed into the concave side of apical region and correction was achieved by rod-rotation and distraction. Two pre-bent long rods were placed into both sides of the scoliosis and global balance was improved by leveling the proximal thoracic vertebrae and distal lumbar vertebrae. RESULTS: A total of 41 patients were included, with an average age of 20 years (range, 12-49 years) and follow-up of 34 months (range, 24-58 months). Postoperative correction rate was 53% for scoliosis. There were 14 patients with normal kyphosis before surgery, and 28 patients with normal kyphosis at the last follow-up. 88% of the patients (23/26) with preoperative coronal imbalance (TS > 20 mm) restored coronal balance at the final follow-up. 87% of the patients (14/16) with preoperative sagittal imbalance (SVA > 40 mm) restored sagittal balance at the final follow-up. The mean operation time and blood loss were 286 min and 941 mL, respectively. No patients had neurological complications or implant failure. CONCLUSION: The surgical strategy of apical region correction and global balance with 3 rods is a safe and effective alternative for the surgical treatment of severe and rigid scoliosis.
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Cifose , Escoliose , Fusão Vertebral , Adulto , Humanos , Cifose/diagnóstico por imagem , Cifose/cirurgia , Estudos Retrospectivos , Escoliose/diagnóstico por imagem , Escoliose/cirurgia , Fusão Vertebral/efeitos adversos , Vértebras Torácicas/diagnóstico por imagem , Vértebras Torácicas/cirurgia , Resultado do Tratamento , Adulto JovemRESUMO
Unbalanced metabolism of an extracellular matrix (ECM) in nucleus pulposus cells (NPCs) is widely acknowledged as the primary cause of intervertebral disc degeneration (IDD). Irisin, a novel myokine, is cleaved from fibronectin type III domain-containing 5 (FNDC5) and has recently been proven to regulate the metabolism of ECM. However, little is known about its potential on NPCs and the development of IDD. Therefore, this study sought to examine the protective effects and molecular mechanism of irisin on IDD in vivo and in vitro. Decreased expression levels of FNDC5 and anabolism markers (COL2A1 and ACAN) but increased levels of catabolism markers (ADAMTS4) were found in degenerative nucleus pulposus (NP) tissues. In a punctured-induced rat IDD model, irisin treatment was found to significantly slow the development of IDD, and in TNF-α-stimulated NPCs, irisin treatment partly reversed the disorder of ECM metabolism. In mechanism, RNA-seq results suggested that irisin treatment affected the Hippo signaling pathway. Further studies revealed that with irisin treatment, the phosphorylation levels of key factors (LATS and YAP) were downregulated, while the expression level of CTGF was upregulated. Moreover, CTGF knockdown partially eliminated the protective effects of irisin on the metabolism of ECM in NPCs, including inhibiting the anabolism and promoting the catabolism. Taken together, this study demonstrated that the expression levels of FNDC5 were decreased in degenerative NP tissues, while irisin treatment promoted the anabolism, inhibited the catabolism of the ECM in NPCs, and delayed the progression of IDD via LATS/YAP/CTGF signaling. These results shed light on the protective actions of irisin on NPCs, leading to the development of a novel therapeutic target for treating IDD.
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Degeneração do Disco Intervertebral , Disco Intervertebral , Núcleo Pulposo , Animais , Ratos , Fator de Crescimento do Tecido Conjuntivo , Matriz Extracelular/metabolismo , Fibronectinas/metabolismo , Disco Intervertebral/metabolismo , Degeneração do Disco Intervertebral/metabolismo , Núcleo Pulposo/metabolismo , Proteínas Serina-Treonina Quinases , Transdução de Sinais , Proteínas de Sinalização YAPRESUMO
[This corrects the article on p. 2205 in vol. 10, PMID: 30093957.].
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Low back pain is one of the top disorders that leads to disability and affects disability-adjusted life years (DALY) globally. Intervertebral disc degeneration (IDD) and subsequent discogenic pain composed major causes of low back pain. Recent studies have identified several important risk factors contributing to IDD's development, such as inflammation, mechanical imbalance, and aging. Based on these etiology findings, three categories of animal models for inducing IDD are developed: the damage-induced model, the mechanical model, and the spontaneous model. These models are essential measures in studying the natural history of IDD and finding the possible therapeutic target against IDD. In this review, we will discuss the technical details of these models, the duration between model establishment, the occurrence of observable degeneration, and the potential in different study ranges. In promoting future research for IDD, each animal model should examine its concordance with natural IDD pathogenesis in humans. We hope this review can enhance the understanding and proper use of multiple animal models, which may attract more attention to this disease and contribute to translation research.
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STUDY DESIGN: Retrospective case series. OBJECTIVES: To present outcomes concerning patients with early-onset mixed-type congenital scoliosis (EOMTCS) treated with the traditional single growing rod (TSGR), focusing on the growth of unsegmented levels (USLs). METHODS: Patients with EOMTCS who underwent TSGR and had a minimum of 4 USLs, 4 distractions, and 3-year follow-up were enrolled. Spine radiographs before and after index surgery and at the latest follow-up were evaluated. The length of the concave and convex side of USLs and thoracic parameters were measured. The absolute value and percentage of growth were calculated. RESULTS: Fourteen patients (mean age, 7.3 ± 2.8 years) were enrolled. The average follow-up duration was 4.9 ± 1.2 years, during which time 84 distractions and 8 final fusions were performed. The average number of USLs was 6.3 ± 2.2. The total and annual percent growth of concave side of USLs was significantly higher than convex side (32.2 ± 13.3% vs. 23.9 ± 9.5%, p = 0.007; 6.8 ± 2.7%/year vs. 5.1% ± 2.2%/year, p = 0.007, respectively). The concave-to-convex ratio of USLs increased from 58.6 ± 6.4 ± 7.6% at baseline to 68.8 ± 9.3% at the latest follow-up (p < 0.001). The Campbell's space available for lung ratio increased from 74.9 ± 11.1% at baseline to 89.6 ± 7.0% at the latest follow-up (p < 0.001). CONCLUSIONS: In patients with EOMTCS, unilateral repetitive lengthening with TSGR can accelerate the growth of the concave side of USLs and improve the symmetry of the thorax.
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STUDY DESIGN: A prospective study. OBJECTIVE: The aim of this study was to investigate the factors associated with cardiopulmonary exercise testing (CPET) measurements in patients with adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: Patients with AIS display restrictive pulmonary dysfunction on pulmonary function testing (PFT). It remains unknown whether thoracic spinal deformity affects exercise performance. METHODS: One hundred and sixty-eight patients with AIS from January 2014 to December 2019 were included. They underwent preoperative spinal radiological assessment, PFT, and CPET. The effects of the thoracic curve magnitude, body mass index, physical activity level and history of bracing on pulmonary function and exercise performance were analyzed. The Student t test and two-tailed Pearson test were used in data analysis. RESULTS: We found significantly reduced forced expiratory volume in 1second (FEV1) in patients with a larger magnitude of the proximal thoracic curve (Pâ<â0.001) and the main thoracic curve (Pâ<â0.001). There was a negative correlation between forced vital capacity (FVC) and the magnitude of the main thoracic curve (Pâ<â0.001) and thoracic hypokyphosis (Pâ<â0.001). In CPET, exercise capacity indicators such as the work rate, peak oxygen intake, and heart rate were not affected by the thoracic curve magnitude. Patients with moderate or severe pulmonary dysfunction had decreased tidal volume (Pâ=â0.01) and ventilatory reserve (Pâ<â0.001), as well as increased respiratory frequency at maximal exercise (Pâ=â0.01). Patients with a moderate or high physical activity level had better exercise capacity, which was reflected by a higher work rate (Pâ=â0.009) and oxygen intake (Pâ<â0.001). CONCLUSION: There was no significant correlation between radiographic parameters and exercise capacity indicators. When the thoracic curve increased, patients had restrictive ventilatory dysfunction, which led to a tachypneic breathing pattern and reduction of ventilatory reserve during exercise. A physiological change of improved peak oxygen intake was demonstrated in patients with a moderate or high physical activity level.Level of Evidence: 3.
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Cifose , Escoliose , Adolescente , Exercício Físico , Volume Expiratório Forçado , Humanos , Pulmão/diagnóstico por imagem , Estudos Prospectivos , Escoliose/diagnóstico por imagem , Capacidade VitalRESUMO
BACKGROUND: There have been no report about the association between physical capacity and health-related quality of life in patients with adolescent idiopathic structural scoliosis (AIS). This study aims to investigate the correlation between dynamic cardiopulmonary capacity and quality of life in AIS patients. METHODS: This retrospective study involved 63 patients. Correlations between cardiopulmonary exercise test parameters and Scoliosis Research Society (SRS)-22 scores were evaluated using Spearman's correlation test. RESULTS: Fifty-four female patients [mean age: 14.1 (range, 10-19) years] and 9 male patients [15.9 (range, 14-19) years] with AIS (Cobb angle: 28°-86°) were included. Significant correlations were found between the peak oxygen uptake normalized by body weight and the SRS-22 scores in female patients, as reflected by the function (r=0.511, P<0.001), pain (r=0.418, P=0.002), mental health (r=0.536, P<0.001) and subtotal (r=0.618, P<0.001) scores. Significant correlations were also found between oxygen uptake at anaerobic threshold normalized by body weight and the SRS-22 scores in female patients, as reflected by the function (r=0.404, P=0.002), pain (r=0.455, P=0.001), and subtotal (r=0.501, P<0.001) scores, along with respiratory exchange ratio reflected by subtotal (r=0.464, P<0.001) score. CONCLUSIONS: The physical capacity and capacity for the exercise intensity and endurance correlated with quality of life among patients with AIS. Exercise may better the quality of life of patients with AIS.
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Qualidade de Vida , Escoliose , Adolescente , Feminino , Humanos , Masculino , Saúde Mental , Dor , Estudos RetrospectivosRESUMO
Tool wear is the main factor of tool failure in cutting difficult-to-machine materials. This paper aims to analyze the anti-friction mechanism of laser machining micro-groove cemented carbide. Firstly, micro-grooves were prepared on the cemented carbide surface by laser processing. Secondly, we conducted an analysis of the mechanical properties of laser texturing by measuring hardness. Finally, we studied the anti-friction mechanism of micro-grooves by a wear test (ASTM G133-05). Results show that surface hardness increases after laser treatment. The friction coefficient and surface wear of micro-groove cemented carbide are significantly reduced compared with the conventional surface. The friction coefficient of PE and OB decreased by 20.6% and 10.7%, respectively. It is found that the direction of micro-grooves determines whether metal debris can be removed-the stronger the ability to remove metal debris, the better the tribological properties of the micro-groove surface.
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BACKGROUND: Early onset scoliosis (EOS) may cause malnutrition in affected patients. Growing-rod treatment has been an effective protocol for treating EOS. The objective of this study is to demonstrate whether growing-rod treatment improves nutritional status of EOS patients. METHODS: Fifty-two EOS patients who had dual growing-rod surgery was enrolled. The minimum follow-up was 3-years. Their body weights were normalized based on the data of two National Population Census of China. Z-scores were used to indicate the standard deviation from the median body weight-for-age. RESULTS: The median follow-up time was 6 years. Preoperatively, the prevalence of malnutrition (Z < - 2) was 21.2%, and reduced to 9.6% at the end of the follow-up. Preoperatively, the average Z-score was - 0.94, and it increased to - 0.65 at the latest follow-up (p < 0.05). Patients with preoperative Z-score below - 1 had more significant increase of Z-scores (- 2.15 vs - 1.26, p < 0.001). A significant negative correlation between the change of Z-score and the preoperative Z-score (correlation coefficient - 0.65, p < 0.001). CONCLUSIONS: The growing rod surgery and lengthening procedures significantly improves the nutrition status of EOS patients. The body weight gains are more significant in patients with lower body weights.
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Estado Nutricional , Escoliose , China , Seguimentos , Humanos , Escoliose/cirurgia , Resultado do TratamentoRESUMO
Tool wear is a major cause of accelerated tool failure during the milling of aluminum alloy. The periodically cutting force directly affect the cutting heat and tool wear due to the intermittent cutting characteristics of the milling process. The focus of this paper is to analyze the influence of the variation of cutting force on tool wear behavior. The change law of cutting force by cutting parameters was analyzed firstly. Secondly, the variation of the wear land width (VB) of tool flank face by the milling length was analyzed. Thirdly, the wear morphology and the energy dispersive spectrometer (EDS) results of tool rake face and flank face in different cutting parameters were observed by tungsten filament scanning electron microscope. Finally, considering the cutting force effect, the tool wear mechanism during high-speed milling of Aluminum-Alloy Die Castings 12 (ADC12, 12 means aluminum number 12) was analyzed. The cutting force in tangential direction is predominant during high-speed milling aluminum alloy, which decreases gradually with the increase of cutting speed but increases gradually with the feed rising. The adhesion-oxidation wear was main wear mechanism of tool rake face during high-speed milling. While adhesive wear was the main wear mechanism of the tool flank face during high-speed milling. It is found that the formation of adhesive wear is the process from particle adhesion to melting until the formation of adhesive layer, which related to the change of cutting force.
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Melatonin is well-documented to have the ability of reducing nerve inflammation and scavenging free radicals. However, the therapeutic effect of melatonin on spinal cord injury has not been fully described. In this study, we assessed the effect of melatonin on T9 spinal cord injury established by Allen method in rats. Melatonin deficiency significantly delayed the recovery of sensory and motor functions in SCI rats. Treatment with melatonin significantly alleviated neuronal apoptosis and accelerated the recovery of spinal cord function. These results suggest that melatonin is effective to ameliorate spinal cord injury through inhibition of neuronal apoptosis and promotion of neuronal repair.
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Melatonina/metabolismo , Traumatismos da Medula Espinal/etiologia , Traumatismos da Medula Espinal/metabolismo , Animais , Apoptose/efeitos dos fármacos , Biomarcadores , Modelos Animais de Doenças , Suscetibilidade a Doenças , Expressão Gênica , Imuno-Histoquímica , Melatonina/farmacologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Corpos de Nissl/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Ratos , Recuperação de Função Fisiológica/efeitos dos fármacos , Traumatismos da Medula Espinal/tratamento farmacológico , Traumatismos da Medula Espinal/patologiaRESUMO
Methylprednisolone (MP) is the drug of choice for treating spinal cord injury (SCI), but the aggressive dosage regimen used often results in adverse side effects. Therefore, MP should be combined with other drugs to lower the required dose. Melatonin is effective in alleviating nerve damage and inhibiting axonal degeneration. The combination of melatonin and half-dose methylprednisolone (HMP) for spinal cord injury treatment has never been reported. In this study, we established a rat model of T9 spinal cord injury by the Allen's method and assessed the synergistic therapeutic effects of melatonin and HMP by factorial design. Our results demonstrated that melatonin could synergize with HMP to ameliorate acute SCI through PI3K-AKT1 pathway. Combining melatonin with HMP significantly reduced the standard-dose of methylprednisolone and limited its adverse reactions, representing a promising option for treating acute SCI.
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Patients with spinal muscular atrophy (SMA) are susceptible to the respiratory infections and might be at a heightened risk of poor clinical outcomes upon contracting coronavirus disease 2019 (COVID-19). In the face of the COVID-19 pandemic, the potential associations of SMA with the susceptibility to and prognostication of COVID-19 need to be clarified. We documented an SMA case who contracted COVID-19 but only developed mild-to-moderate clinical and radiological manifestations of pneumonia, which were relieved by a combined antiviral and supportive treatment. We then reviewed a cohort of patients with SMA who had been living in the Hubei province since November 2019, among which the only 1 out of 56 was diagnosed with COVID-19 (1.79%, 1/56). Bioinformatic analysis was carried out to delineate the potential genetic crosstalk between SMN1 (mutation of which leads to SMA) and COVID-19/lung injury-associated pathways. Protein-protein interaction analysis by STRING suggested that loss-of-function of SMN1 might modulate COVID-19 pathogenesis through CFTR, CXCL8, TNF and ACE. Expression quantitative trait loci analysis also revealed a link between SMN1 and ACE2, despite low-confidence protein-protein interactions as suggested by STRING. This bioinformatic analysis could give hint on why SMA might not necessarily lead to poor outcomes in patients with COVID-19.