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1.
Opt Express ; 32(5): 6945-6962, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38439388

RESUMO

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.

2.
Acta Biochim Biophys Sin (Shanghai) ; 56(5): 776-788, 2024 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-38495003

RESUMO

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.


Assuntos
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 & derivados
3.
Brief Bioinform ; 22(2): 1291-1296, 2021 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-33190150

RESUMO

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.


Assuntos
Enzima de Conversão de Angiotensina 2/metabolismo , COVID-19/metabolismo , Atrofia Muscular Espinal/complicações , Proteína 1 de Sobrevivência do Neurônio Motor/metabolismo , COVID-19/virologia , Suscetibilidade a Doenças , Humanos , Atrofia Muscular Espinal/metabolismo , Atrofia Muscular Espinal/prevenção & controle , Ligação Proteica , Mapas de Interação de Proteínas , Sistema Renina-Angiotensina , SARS-CoV-2/isolamento & purificação , Transdução de Sinais , Proteína 1 de Sobrevivência do Neurônio Motor/genética
4.
BMC Musculoskelet Disord ; 23(1): 918, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36243704

RESUMO

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.


Assuntos
Escoliose , Terapia por Exercício/métodos , Humanos , Modalidades de Fisioterapia , Estudos Retrospectivos , Escoliose/diagnóstico por imagem , Escoliose/terapia , Resultado do Tratamento
5.
BMC Musculoskelet Disord ; 23(1): 775, 2022 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-35964038

RESUMO

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.


Assuntos
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 Jovem
6.
J Cell Mol Med ; 25(6): 2909-2917, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33497543

RESUMO

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.


Assuntos
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/patologia
7.
BMC Surg ; 21(1): 106, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33648467

RESUMO

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.


Assuntos
Estado Nutricional , Escoliose , China , Seguimentos , Humanos , Escoliose/cirurgia , Resultado do Tratamento
8.
J Cell Mol Med ; 24(12): 7015-7022, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32394619

RESUMO

Congenital scoliosis (CS) is a form of spinal curvature resulting from anomalous development of vertebrae. Recent studies demonstrated that circRNAs could serve as potential biomarkers of disease diagnosis. Genome-wide circRNAs expression in seven CS patients and three healthy controls was initially detected. Bioinformatics analysis was conducted to explore the potential pathological pathway of CS. Quantitative PCR (qPCR) was performed to validate the selected circRNAs in the replication cohort with 32 CS patients and 30 healthy controls. Logistic regression controlling for gender was conducted to compare the expression difference. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic value. Twenty-two differentially expressed circRNAs were filtered from genome-wide circRNA sequencing. Seven circRNAs were validated by qPCR. Only hsa_circ_0006719 was confirmed to have a higher expression level in the CS group than the healthy control group (P = 0.036). Receiver operating characteristic curve also suggested that hsa_circ_0006719 had significant diagnostic value for CS (AUC = 0.739, P = 0.001). We described the first study of circRNAs in CS and validated hsa_circ_0006719 as a potential novel diagnostic biomarker of CS.


Assuntos
Genoma Humano , RNA Circular/genética , Escoliose/congênito , Escoliose/genética , Sequência de Bases , Biomarcadores/metabolismo , Estudos de Casos e Controles , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Ontologia Genética , Humanos , Modelos Logísticos , Masculino , RNA Circular/metabolismo , Curva ROC , Reprodutibilidade dos Testes , Escoliose/diagnóstico
9.
J Cell Mol Med ; 23(7): 4582-4591, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31044535

RESUMO

Congenital scoliosis (CS) is the result of anomalous vertebrae development, but the pathogenesis of CS remains unclear. Long non-coding RNAs (lncRNAs) have been implicated in embryo development, but their role in CS remains unknown. In this study, we investigated the role and mechanisms of a specific lncRNA, SULT1C2A, in somitogenesis in a rat model of vitamin A deficiency (VAD)-induced CS. Bioinformatics analysis and quantitative real-time PCR (qRT-PCR) indicated that SULT1C2A expression was down-regulated in VAD group, accompanied by increased expression of rno-miR-466c-5p but decreased expression of Foxo4 and somitogenesis-related genes such as Pax1, Nkx3-2 and Sox9 on gestational day (GD) 9. Luciferase reporter and small interfering RNA (siRNA) assays showed that SULT1C2A functioned as a competing endogenous RNA to inhibit rno-miR-466c-5p expression by direct binding, and rno-miR-466c-5p inhibited Foxo4 expression by binding to its 3' untranslated region (UTR). The spatiotemporal expression of SULT1C2A, rno-miR-466c-5p and Foxo4 axis was dynamically altered on GDs 3, 8, 11, 15 and 21 as detected by qRT-PCR and northern blot analyses, with parallel changes in Protein kinase B (AKT) phosphorylation and PI3K expression. Taken together, our findings indicate that SULT1C2A enhanced Foxo4 expression by negatively modulating rno-miR-466c-5p expression via the PI3K-ATK signalling pathway in the rat model of VAD-CS. Thus, SULT1C2A may be a potential target for treating CS.


Assuntos
Fatores de Transcrição Forkhead/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Longo não Codificante/metabolismo , Escoliose/congênito , Escoliose/genética , Transdução de Sinais , Regiões 3' não Traduzidas/genética , Animais , Sequência de Bases , Regulação para Baixo/genética , Embrião de Mamíferos/metabolismo , Fatores de Transcrição Forkhead/genética , Regulação da Expressão Gênica no Desenvolvimento , Genes Reporter , Células HEK293 , Humanos , Luciferases/metabolismo , MicroRNAs , Modelos Biológicos , Organogênese/genética , RNA Longo não Codificante/genética , Ratos Sprague-Dawley , Somitos/embriologia , Deficiência de Vitamina A/embriologia , Deficiência de Vitamina A/genética
10.
Cell Physiol Biochem ; 48(5): 2134-2146, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30110682

RESUMO

BACKGROUND/AIMS: Congenital scoliosis (CS) is a result of anomalous development of vertebrae and is frequently associated with somitogenesis malformation. Although noncoding RNAs (ncRNAs) have been recently determined to be involved in the pathogenesis of CS, the competing endogenous RNA (ceRNA) regulatory networks in CS remain largely unknown. METHODS: Sequencing was conducted to explore the ncRNA expression profiles in rat embryos (gestation day 9) following vitamin A deficiency (VAD) (n = 9 for the vitamin A deficiency-induced congenital scoliosis (VAD-CS) group and n = 4 for the control group). Real-time reverse transcriptase polymerase chain reaction (RT-PCR) was conducted to verify the expression levels of selected mRNAs, long noncoding RNAs (lncRNAs), circular RNAs (circRNAs), and microRNAs (miRNAs). Bioinformatics analysis was used to discover the possible relationships and functions of the ceRNAs. RESULTS: A total of 749 mRNAs, 56 miRNAs, 685 lncRNAs, and 70 circRNAs were identified to have significantly different expression levels in the two groups. Wnt, PI3K-ATK, FoxO, EGFR, and mTOR were found to be the most significant pathways involved in VAD-CS pathogenesis. The circRNA/miRNA/mRNA and lncRNA/miRNA/mRNA networks of CS were built, and the gene expression mechanisms regulated by ncRNAs were unveiled via the ceRNA regulatory networks. CONCLUSION: We comprehensively identified ceRNA regulatory networks of embryonic somite development in VAD-CS as well as revealed the contribution of different ncRNA expression profiles. Our data demonstrate the association between mRNAs and ncRNAs in the pathogenic mechanism of CS.


Assuntos
Redes Reguladoras de Genes , RNA/metabolismo , Escoliose/patologia , Animais , Biologia Computacional , Modelos Animais de Doenças , Regulação para Baixo/genética , Embrião de Mamíferos/metabolismo , Feminino , Redes Reguladoras de Genes/genética , MicroRNAs/metabolismo , RNA/química , RNA Circular , RNA Longo não Codificante/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Escoliose/etiologia , Escoliose/genética , Regulação para Cima/genética , Deficiência de Vitamina A/complicações , Deficiência de Vitamina A/patologia
11.
Appl Opt ; 56(3): B58-B63, 2017 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-28157865

RESUMO

The collaborative development of infrared detector materials by the Army Research Laboratory and Stony Brook University has led to new fundamental understandings of materials, as well as new levels of control and flexibility in III-V semiconductor crystal growth by molecular beam epitaxy. Early work on mid-wave strained layer superlattice (SLS) cameras led to a subsequent focus on minority carrier lifetime studies, which resulted in the proposal of the Ga-free SLS on GaSb substrates. The later demonstration of virtual substrate technology allowed the lattice constant to become a design parameter and enabled growth of undistorted bulk InAsSb. When grown in that manner, InAsSb has a bandgap bowing parameter large enough to cover absorption wavelengths across the entire long-wavelength band (8-12 µm). Even longer wavelengths are achieved with a general Ga-free SLS approach, with a virtual substrate having a lattice constant significantly larger than that of GaSb and with InAsSb in both bi-layers in the period. Since these layers can also be made very thin, the general Ga-free SLS does not suffer from the relatively low optical absorption and poor hole transport, which is characteristic of the special Ga-free SLS on GaSb for long-wavelength designs. Finally, the general Ga-free InAsSb SLS provides a method to induce and control sustained atomic ordering, which is yet another new design parameter.

12.
BMC Surg ; 17(1): 83, 2017 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-28716073

RESUMO

BACKGROUND: Hyperlordosis is common in facioscapulohumeral muscular dystrophy (FSHD), which cannot be controlled by bracing. While the surgical treatment is neither reported nor recommended in previous studies, we report the first corrective surgery for hyperlordosis in one wheelchair-dependent FSHD patient. CASE PRESENTATION: A 15-year-old, wheelchair-dependent girl complaining of hyperlordosis and lower extremity weakness was diagnosed as FSHD. Preoperative examination showed hyperlordosis of 116° with scoliosis of 44°. Posterior correction and bone graft fusion was performed. Postoperatively, the hyperlordosis was corrected to 72° and better sitting posture was gotten. 12 months' follow-up showed favorable correction with improvement in SF-36 and ODI score. CONCLUSIONS: The correction for hyperlordosis in FSHD is controversial. We report the first successful case of operative treatment by corrective spine surgery in these rare and demanding patient collective. Corrective surgery for spinal deformity, such as hyperlordosis and scoliosis, could do some help in posture and improve the quality of life especially in wheelchair-dependent patients.


Assuntos
Lordose/cirurgia , Distrofia Muscular Facioescapuloumeral/cirurgia , Escoliose/cirurgia , Fusão Vertebral/métodos , Adolescente , Feminino , Humanos , Qualidade de Vida , Resultado do Tratamento
13.
Eur Spine J ; 25(10): 3180-3185, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-26980603

RESUMO

PURPOSE: Study of patients with adolescent idiopathic scoliosis. OBJECTIVE: To examine the correlation between pulmonary arterial pressure and coronal Cobb angle of idiopathic scoliosis. METHODS: A total of 338 patients (82.8 % female) with idiopathic scoliosis (average age 15.6 years; range 14-20 years) were included. Preoperatively, the coronal Cobb angle of curvature and the apex location and direction were determined from radiographic records. Tricuspid regurgitation velocity (TRV) and inferior vena cava diameter were also measured using Doppler echocardiography. Pulmonary arterial systolic pressure (sPAP) was calculated from the TRV according to the modified Bernoulli equation and correlations between sPAP and the features of scoliosis were identified by statistical analysis. RESULTS: Among the 338 patients, there were 305 thoracic curves, 276 (90.5 %) of which were right curves, and 265 thoracolumbar/lumbar curves. sPAP varied from 5.0 to 37.6 mmHg. Pulmonary hypertension could not be excluded in the case of one patient. A mild correlation (Spearman test, correlation coefficient = 0.187, P = 0.001) between sPAP and coronal Cobb angle of the main thoracic (MT) curves was identified. Correlations between sPAP and the degree of other curves were not significant. Patients with sPAP >20 mmHg also had larger thoracic curve angles (mean MT 42.16° vs. 52.45°; U test, P = 0.002). There were no differences in sPAP levels between patients with right and left thoracic curves. CONCLUSIONS: A mild positive correlation was identified between sPAP and the coronal Cobb angle of the MT curves. There was no relationship between sPAP and the direction of the curvature.


Assuntos
Pressão Sanguínea/fisiologia , Artéria Pulmonar/fisiologia , Escoliose/patologia , Adolescente , Adulto , Criança , Feminino , Humanos , Cifose/fisiopatologia , Masculino , Estudos Retrospectivos , Escoliose/fisiopatologia , Vértebras Torácicas/patologia , Adulto Jovem
14.
Spine J ; 24(2): 317-324, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37844628

RESUMO

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.


Assuntos
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/epidemiologia
15.
Materials (Basel) ; 16(2)2023 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-36676552

RESUMO

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.

16.
Micromachines (Basel) ; 14(1)2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36677285

RESUMO

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.

17.
Stem Cells Dev ; 32(5-6): 115-130, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36647682

RESUMO

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.


Assuntos
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/metabolismo
18.
Global Spine J ; 12(5): 922-930, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33203246

RESUMO

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.

20.
Front Surg ; 9: 1089244, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36969323

RESUMO

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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