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As nitric oxide (NO) plays significant roles in a variety of physiological processes, the capability for real-time and accurate detection of NO in live organisms is in great demand. Traditional assessments of NO rely on indirect colorimetric techniques or electrochemical sensors that often comprise rigid constituent materials and can hardly satisfy sensitivity and spatial resolution simultaneously. Here, we report a flexible and highly sensitive biosensor based on organic electrochemical transistors (OECTs) capable of continuous and wireless detection of NO in biological systems. By modifying the geometry of the active channel and the gate electrodes of OECTs, devices achieve optimum signal amplification of NO. The sensor exhibits a low response limit, a wide linear range, high sensitivity, and excellent selectivity, with a miniaturized active sensing region compared with a conventional electrochemical sensor. The device demonstrates continuous detection of the nanomolar range of NO in cultured cells for hours without significant signal drift. Real-time and wireless measurement of NO is accomplished for 8 d in the articular cavity of New Zealand White rabbits with anterior cruciate ligament (ACL) rupture injuries. The observed high level of NO is associated with the onset of osteoarthritis (OA) at the later stage. The proposed device platform could provide critical information for the early diagnosis of chronic diseases and timely medical intervention to optimize therapeutic efficacy.
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Técnicas Biossensoriais , Óxido Nítrico , Osteoartrite , Tecnologia sem Fio , Animais , Técnicas Biossensoriais/métodos , Doença Crônica , Diagnóstico Precoce , Técnicas Eletroquímicas/métodos , Eletrodos , Óxido Nítrico/análise , Osteoartrite/diagnóstico , CoelhosRESUMO
The application of an external magnetic field has been shown to improve the Cd phytoremediation efficiency of F. arundinacea by leaf harvesting. However, the influencing mechanisms of the promoting effect have not yet been revealed. This study evaluated variations in the Cd subcellular allocation and fractions in various F. arundinacea leaves, with or without magnetized water irrigation. Over 50 % of the metal were sequestered within the cell wall in all tissues under all treatments, indicating that cell wall binding was a critical detoxification pathway for Cd. After magnetized water treatment, the metal stored in the cytoplasm of roots raised from 33.1 % to 45.3 %, and the quantity of soluble Cd in plant roots enhanced from 53.4 % to 59.0 %. The findings suggested that magnetized water mobilized Cd in the roots, and thus drove it into the leaves. In addition, the proportion of Cd in the organelles, and the concentration of ethanol-extracted Cd in emerging leaves, decreased by 13.0 % and 47.1 %, respectively, after magnetized water treatment. These results explained why an external field improved the phytoextraction effect of the plant through leaf harvesting.
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Biodegradação Ambiental , Cádmio , Festuca , Folhas de Planta , Raízes de Plantas , Folhas de Planta/metabolismo , Cádmio/toxicidade , Cádmio/metabolismo , Raízes de Plantas/metabolismo , Festuca/metabolismo , Festuca/efeitos dos fármacos , Irrigação Agrícola/métodos , Poluentes do Solo/metabolismo , Poluentes do Solo/toxicidade , Água/químicaRESUMO
Implementing an external magnetic field of suitable strength has been reported to increase Cd uptake by Noccaea caerulescence. However, only a few mechanisms promoting this efficiency have been reported. A series of culture experiments was conducted to explore how Cd subcellular distribution and speciation vary within the tissue of N. caerulescens when subjected to external magnetic fields of different intensities. Without a magnetic field, over 80% of the Cd was deposited in the cell wall and cytoplasm, indicating that cell wall retention and cytoplasm isolation are significant mechanisms for the detoxification of Cd. An external magnetic field (120 mT) increased the Cd concentrations deposited in the cytoplasm and water-soluble inorganic Cd in the roots, increasing the cell wall-bound Cd and undissolved Cd phosphate in the shoots. Meanwhile, the magnetic field increased carbonic anhydrase activity in plant shoots, except at 400 mT. These results indicated that an external field can elevate the Cd decontamination capacity of N. caerulescens by changing the subcellular compartmentalization and speciation of Cd in different tissues.
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Brassicaceae , Poluentes do Solo , Cádmio/análise , Biodegradação Ambiental , Poluentes do Solo/análise , Campos Magnéticos , Raízes de Plantas/químicaRESUMO
OBJECTIVE: We aimed to evaluate the clinical efficacy and prognostic significance of intensity-modulated radiotherapy (IMRT)-based salvage concurrent chemoradiotherapy (CCRT) for patients with locoregional recurrence cervical cancer after radical hysterectomy and evaluated two salvage radiotherapy modes-regional RT (involved-field RT combined with regional lymph nodes) and local RT (involved-field RT). METHODS: Patients were enrolled retrospectively from January 2011 to January 2022 in three medical centers. Clinical outcomes were analyzed using the Kaplan-Meier method and a Cox proportional hazards model. Propensity score (PS) matching analysis was used to compare the two RT groups. RESULTS: There were 72 patients underwent IMRT-based salvage CCRT. The 5-year overall survival and progression-free survival rates were 65.9% and 57.6%, respectively. Univariate analysis showed that patients with stump recurrence, a lower systemic inflammation response index (SIRI), only one metastatic lesion, and received regional RT had better prognosis than their counterparts. In multivariate analysis, recurrence site was the independent prognostic factor of OS, and SIRI was that of PFS. After PS matching, there were 15 patients each in the regional RT group and local RT group. The 5-year OS rate of regional RT group was better than that of local RT group (90.9 vs. 42.4, p = 0.021). However, there was no significant difference between them in terms of PFS rate (47.1 vs. 38.1, p = 0.195). CONCLUSION: Locoregional recurrent cervical cancer treated with IMRT-based salvage therapy has a good prognosis. Recurrence site and SIRI were independent prognostic factors. Regional RT may be a better option for patients with locoregional recurrent.
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Radioterapia de Intensidade Modulada , Neoplasias do Colo do Útero , Feminino , Humanos , Prognóstico , Estudos Retrospectivos , Neoplasias do Colo do Útero/radioterapia , Neoplasias do Colo do Útero/cirurgia , Estadiamento de Neoplasias , Recidiva Local de Neoplasia/patologia , Quimiorradioterapia , HisterectomiaRESUMO
In this study, the phytoremediation efficiency of Arabidopsis halleri L. in response to mechanical injury were compared between those irrigated with magnetized water and those irrigated with normal water. Under normal irrigation treatment, wounding stress increased malondialdehyde (MDA) concentrations and hydrogen peroxide (H2O2) levels in A. halleri leaves significantly, by 46.7-86.1% and 39.4-77.4%, respectively, relative to those in the intact tissues. In addition, wounding stresses decreased the content of Cd in leaves by 26.8-52.2%, relative to the control, indicating that oxidative damage in plant tissues was induced by mechanical injury, rather than Cd accumulation. There were no significant differences in MDA and H2O2 between A. halleri irrigated with magnetized water and with normal water under wounding conditions; however, the activities of catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) in the leaves of plants treated with magnetized water were significantly increased by 25.1-56.7%, 47.3-183.6%, and 44.2-109.4%, respectively. Notably, under the magnetic field, the phytoremediation effect of 30% wounded A. halleri nearly returned to normal levels. We find that irrigation with magnetized water is an economical pathway to improve the tolerance of A. halleri to inevitable mechanical injury and may recover its phytoremediation effect.
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Botrytis cinerea is listed among the most important fungal pathogens infecting strawberries. The use of biological control agents, such as Bacillus species, offers an alternative and effective way to reduce airborne pathogens. The aim of this research was to select the macrolactin R produced by Bacillus siamensis with potential for using as biological agents against the pathogenetic fungi (Botrytis cinerea) of strawberries, and to assess the mechanisms involved. Macrolactin R had significant inhibitory effects on spore germination, germ tube elongation, and mycelial growth of Botrytis cinerea. The MICs of macrolactin R inhibitions in vitro was 12.5 mg/L and The EC50 value of NJ08-3 to Botrytis cinerea spores and mycelial was 1.93 and 2.88 mg/L, respectively. Macrolactin R impacted the membrane structure of Botrytis cinerea, resulting in changes in membrane permeability and leakage of proteins and nucleic acids, then cell death. The application of the macrolactin R of Bacillus siamensis reduced the disease severity index of gray mold on strawberries. This study demonstrated that the production of macrolactin R produced by Bacillus siamensis are involved in the antifungal activity against Botrytis cinerea.
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Antifúngicos , Bacillus , Antifúngicos/farmacologia , Micélio , Botrytis , Doenças das Plantas/prevenção & controle , Doenças das Plantas/microbiologiaRESUMO
AIM: Cervical cancer has attracted increasing attention in recent years, and the incidence has shown a trend of younger age. Therefore, it is an effective method to regulate the progression of cervical cancer through new prognostic biomarkers. The purpose of this study was to evaluate the potential of lncRNA LAMTOR5-AS1 (LAMTOR5-AS1) as a prognostic biomarker and reveal its regulatory role in cervical cancer. METHODS: A total of 120 patients with cervical cancer were selected as research subjects to verify the prognostic effect of LAMTOR5-AS1 in a series of experiments. The expression of LAMTOR5-AS1 in cervical cancer tissues and cells was determined by polymerase chain reaction assay. The proliferation, migration, and invasion ability of cervical cancer cells were evaluated by Cell Counting Kit-8 (CCK-8) and Transwell assay. Luciferase reporter gene detection was used to determine the mechanism of LAMTOR5-AS1 targeting miR-210-3p, and to reflect the prognostic value of LAMTOR5-AS1 according to statistical methods. RESULTS: LAMTOR5-AS1 decreased in cervical cancer tissues, while miR-210-3p expression increased. In the study of cervical cancer cells, it was found that the LAMTOR5-AS1 sponge miR-210-3p was associated with the malignant progression of cervical cancer. Overexpression of LAMTOR5-AS1 could effectively inhibit the development of cervical cancer cells and might be chosen as a prognostic biomarker of cervical cancer. CONCLUSIONS: LAMTOR5-AS1 sponges miR-210-3p and modulates the progression of cervical cancer, which predict the prognosis of cervical cancer patients.
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MicroRNAs , RNA Longo não Codificante , Neoplasias do Colo do Útero , Feminino , Humanos , RNA Longo não Codificante/genética , Neoplasias do Colo do Útero/patologia , MicroRNAs/metabolismo , Regulação Neoplásica da Expressão Gênica , Movimento Celular/genética , Proliferação de Células/genética , Linhagem Celular Tumoral , BiomarcadoresRESUMO
OBJECTIVE: To explore the molecular mechanisms of a Chinese pedigree with hereditary factor â ª (Fâ ª) deficiency. METHODS: All of the 15 exons, flanking sequences of the Fâ ª gene and the corresponding mutation sites of family members were analyzed by the Sanger sequencing, followed by the extraction of the peripheral blood genomic DNA. And all the results were verified by the reverse sequencing. The conservation of the mutated sites was analyzed by the ClustalX-2.1-win. Three online bioinformatics software tools, including Mutation Taster, PolyPhen2 and the PROVEAN, were used to assess the possible impact of the mutations. Swiss-pdbviewer software was used to analyze the effects of mutant amino acids on protein structure. RESULTS: Genetic analysis revealed that the proband had compound heterozygous mutations including a nonsense mutation of c.1107C>A (Tyr369stop) in exon 10 and missense mutation of c.1562A>G (Tyr521Cys) in exon 13. The same c.1107C>A (Tyr369stop) was present in her father, the same c.1562A>G (Tyr521Cys) was present in both her mother and daughter. Conservation analysis indicated that Tyr521 was a highly conserved site during evolution. The prediction of pathogenicity showed that both c.1107C>A and c.1562A>G were pathogenic mutations. Protein structure prediction showed that in the wild type Fâ ª protein structure, Tyr521 formed a hydrogen bond with the Lys572 and Ile388, respectively. When Tyr521 was replaced by Cys521, the original benzene ring structure disappeared, and side chains of Lys572 added a hydrogen bond with the Cys521, which may change protein catalytic domain structure. When Tyr369 was mutated to a stop codon, resulting in the truncated protein. CONCLUSION: The compound heterozygous mutations including the c.1107C>A heterozygous missense variant in exon 10 and the c.1562A>G heterozygous nonsense mutation in exon 13 may be responsible for the hereditary factor â ª deficiency in this Chinese pedigree.
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Deficiência do Fator XI , Fator XI , Códon sem Sentido , Fator XI/genética , Deficiência do Fator XI/genética , Feminino , Heterozigoto , Humanos , Mutação , LinhagemRESUMO
Chinese government adopted a new environmental program during "Eleventh Five-Year Plan" period. Whether this program can achieve its goal of pollution reduction and quality improvement for exports is of vital importance for China's sustainable development. This paper constructs a quasi-difference-in-difference (DID) framework to identify the effects of the new environmental policy on export product quality by using highly disaggregated trade transaction data at the product level. Empirical results show that the implementation of pollution reduction targets is negatively correlated with export product quality. This negative impact is more profound in western regions, capital-intensive industries, privately owned firms and firms exporting to countries which are not members of Organization for Economic Co-operation and Development group. In addition, our extended analysis shows that the negative effects can be mitigated through product switching within the firms. The major policy implication is that local governments should take proper measures to strengthen the effects of innovation offsets caused by environmental regulation and effectively utilize the induced effects of environmental regulation on product switching. The goal is to achieve a win-win outcome for environmental protection and improvement in export product quality.
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Política Ambiental , Poluição Ambiental , China , Conservação dos Recursos Naturais , Poluição Ambiental/análise , IndústriasRESUMO
The current study explored the protective effect of leucine on antioxidant status, apoptosis and tight junction damage in the gill of grass carp (Ctenopharyngodon idella Val.). The trial was conducted by feeding grass carp with six graded level of leucine (7.1, 8.9, 11.0, 13.3, 15.2 and 17.1 g kg-1 diet) for 8 weeks. The fish were fed to apparent satiation 4 times per day. The results indicated that compared with the leucine deficiency group, 8.9-11.3 g leucine kg-1 diet supplementations decreased protein carbonyl (PC), malondialdehyde (MDA) and ROS contents, which may be partially attributed to the improvement of antioxidant status in the gill by increasing hydroxyl radical capacity and anti-superoxide radicals, glutathione contents and the activities and mRNA levels of Cu/Zn superoxide dismutase (SOD1), glutathione peroxidase (GPx), catalase (CAT), glutathione-S-transferase (GST) and glutathione reductase (GR), that referring to the up-regulation of nuclear factor erythroid 2-related factor 2 (Nrf2) mRNA expression. Moreover, leucine deficiency induced DNA fragmentation via the up-regulation of caspase-3, caspase-8 and caspase-9 expressions and down-regulation of target of rapamycin and ribosomal S6 protein kinase 1 expressions. Furthermore, leucine deficiency increased interleukin-1ß (IL-1ß), interleukin-8 (IL-8) and tumor necrosis factor-α (TNF-α) mRNA expression and decreased IL-10 and transforming growth factor ß (TGF-ß), which was partly related to nuclear factor κB (NF-κB) and its inhibitor (IκB). In contrast, the relative mRNA expression of IL-1, IL-8 and TNF-α was down-regulated with 8.9-11.3 g leucine kg-1 diet supplementations. Finally, the relative mRNA expression of tight junction protein, including occludin, zonula occludens-1, claudin b, claudin 3 and claudin 12 was up-regulated with leucine diet supplementations. Our results indicate that leucine protected the fish gill structural integrity partially because of the inhibition of apoptosis, the improvement of antioxidant status, the regulation of tight junction protein and related signalling molecules mRNA expressions in the fish gill.
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Apoptose , Carpas/imunologia , Imunidade Inata , Leucina/deficiência , Estresse Oxidativo , Proteínas de Junções Íntimas/genética , Ração Animal/análise , Animais , Antioxidantes/metabolismo , Carpas/genética , Dieta/veterinária , Suplementos Nutricionais/análise , Relação Dose-Resposta a Droga , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Brânquias/imunologia , Brânquias/patologia , Leucina/administração & dosagem , Leucina/metabolismo , Distribuição Aleatória , Proteínas de Junções Íntimas/metabolismoRESUMO
BACKGROUND: To investigate the diagnostic value of dual-source computed tomography (DSCT) in the evaluation of tetralogy of Fallot (TOF)-associated extracardiac vascular abnormalities in pediatric patients compared with transthoracic echocardiography (TTE). METHODS: One hundred and twenty-three pediatric patients diagnosed with TOF were included in this retrospective study. All patients underwent DSCT and TTE preoperatively. All associated extracardiac vascular abnormalities and their percentages were recorded. The diagnostic performances of DSCT and TTE were compared based on the surgical results. The image quality of DSCT was rated, and the effective radiation dose (ED) was calculated. RESULTS: A total of 159 associated extracardiac vascular deformities were confirmed by surgery. Patent ductus arteriosus (36, 22.64%), right-sided aortic arch (29, 18.24%), and pulmonary valve stenosis (23, 14.47%) were the most common associated extracardiac vascular abnormalities. DSCT was superior to TTE in demonstrating associated extracardiac anomalies (diagnostic accuracy: 99.13% vs. 97.39%; sensitivity: 92.45% vs. 77.07%; specificity: 99.81% vs. 99.42%). The agreement on grading the image quality of DSCT was excellent (κ = 0.80), and the mean score of the image quality was 3.39 ± 0.50. The mean ED of DSCT was 0.86 ± 0.47 mSv. CONCLUSIONS: Compared to TTE, low-dose DSCT has high diagnostic accuracy in the depiction of associated extracardiac vascular anomalies in pediatric patients with TOF, and could provide more morphological details for surgeons.
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Ecocardiografia , Doses de Radiação , Tetralogia de Fallot/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Malformações Vasculares/diagnóstico por imagem , Fatores Etários , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Valor Preditivo dos Testes , Exposição à Radiação/efeitos adversos , Exposição à Radiação/prevenção & controle , Reprodutibilidade dos Testes , Estudos Retrospectivos , Fatores de Risco , Tomografia Computadorizada por Raios X/efeitos adversosRESUMO
OBJECTIVE: To study the clinical characteristics of childhood Henoch-Schonlein purpura (HSP) on the Tibetan Plateau, China. METHODS: One hundred and twenty-five HSP children admitted to Shannan People's Hospital, Tibet, were assigned to the observation group, and 96 HSP children admitted to Wuhan Children's Hospital were assigned to the control group. The disease characteristics, clinical manifestations, treatment, and prognosis in both groups were retrospectively analyzed and compared. RESULTS: The mean age of HSP onset and the female-to-male ratio in the observation group were both significantly higher than in the control group (P<0.05). There was a significant difference in seasonal onset between two groups. Significant differences in the etiological factors were observed between the two groups (P<0.05). The gastrointestinal manifestation was more prominent in the observation group compared with that in the control group (P<0.05). Laboratory findings showed that the mean erythrocyte sedimentation rate, counts of white blood cells and platelets, and percentage of neutrophil leucocytes were significantly lower, while the hemoglobin level was significantly higher in the observation group than in the control group (P<0.05). A total of 124 HSP patients (99.2%) in the observation group had a full recovery or improvement, and the overall cure rate and improvement rate showed no significant differences between two groups (P>0.05). Only 2.4% of the patients (3 cases) in the observation group had recurrent attack during follow-up, which was significantly lower than that in the control group (16.7%; P<0.05). CONCLUSIONS: Childhood HSP on the Tibetan Plateau shows partial differences in disease characteristics, clinical manifestations, and laboratory measurements compared with that in the plain area. The overall prognosis is better and the recurrent rate is lower among HSP children on the Tibetan Plateau.
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Vasculite por IgA/tratamento farmacológico , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Vasculite por IgA/diagnóstico , Vasculite por IgA/etiologia , Masculino , Prognóstico , TibetRESUMO
To investigate the critical role of the S gene in determining pathogenesis of TW-like avian infectious bronchitis virus (IBV), we generated two recombinant IBVs (rGDaGD-S1 and rGDaGD-S2) by replacing either the S1 or S2 region of GD strain with the corresponding regions from an attenuated vaccine candidate aGD strain. The virulence and pathogenicity of these recombinant viruses was assessed both in vitro and in vivo. Our results indicated the mutations in the S2 region led to decreased virulence, as evidenced by reduced virus replication in embryonated chicken eggs and chicken embryonic kidney cells as well as observed clinical symptoms, gross lesions, microscopic lesions, tracheal ciliary activity, and viral distribution in SPF chickens challenged with recombinant IBVs. These findings highlight that the S2 subunit is a key determinant of TW-like IBV pathogenicity. Our study established a foundation for future investigations into the molecular mechanisms underlying IBV virulence.
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Infecções por Coronavirus , Vírus da Bronquite Infecciosa , Doenças das Aves Domésticas , Vacinas Virais , Embrião de Galinha , Animais , Galinhas , Infecções por Coronavirus/veterinária , Glicoproteína da Espícula de Coronavírus/genética , OligopeptídeosRESUMO
Tumor-associated macrophages of the M2 phenotype promote cancer initiation and progression. Importantly, M2 macrophage-derived exosomes play key roles in the malignancy of cancer cells. Here, we report that circTMCO3 is upregulated in ovarian cancer patients, and its high expression indicates poor survival. M2-derived exosomes promote proliferation, migration, and invasion in ovarian cancer, but these effects are abolished by knockdown of circTMCO3. Furthermore, circTMCO3 functions as a competing endogenous RNA for miR-515-5p to reduce its abundance, thus upregulating ITGA8 in ovarian cancer. miR-515-5p inhibits ovarian cancer malignancy via directly downregulating ITGA8. The decreased oncogenic activity of circTMCO3-silencing exosomes is reversed by miR-515-5p knockdown or ITGA8 overexpression. Exosomal circTMCO3 promotes ovarian cancer progression in nude mice. Thus, M2 macrophage-derived exosomes promote malignancy by delivering circTMCO3 and targeting the miR-515-5p/ITGA8 axis in ovarian cancer. Our findings not only provide mechanistic insights into ovarian cancer progression, but also suggest potential therapeutic targets.
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Exossomos , Cadeias alfa de Integrinas , Macrófagos , MicroRNAs , Neoplasias Ovarianas , RNA Circular , Animais , Feminino , Humanos , Camundongos , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Exossomos/metabolismo , Exossomos/genética , Regulação Neoplásica da Expressão Gênica , Cadeias alfa de Integrinas/genética , Cadeias alfa de Integrinas/metabolismo , Macrófagos/metabolismo , Camundongos Nus , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/metabolismo , RNA Circular/genética , RNA Circular/metabolismoRESUMO
The incorporation of engineered muscle-tendon junction (MTJ) with organ-on-a-chip technology provides promising in vitro models for the understanding of cell-cell interaction at the interface between muscle and tendon tissues. However, developing engineered MTJ tissue with biomimetic anatomical interface structure remains challenging, and the precise co-culture of engineered interface tissue is further regarded as a remarkable obstacle. Herein, an interwoven waving approach is presented to develop engineered MTJ tissue with a biomimetic "M-type" interface structure, and further integrated into a precise co-culture microfluidic device for functional MTJ-on-a-chip fabrication. These multiscale MTJ scaffolds based on electrospun nanofiber yarns enabled 3D cellular alignment and differentiation, and the "M-type" structure led to cellular organization and interaction at the interface zone. Crucially, a compartmentalized co-culture system is integrated into an MTJ-on-a-chip device for the precise co-culture of muscle and tendon zones using their medium at the same time. Such an MTJ-on-a-chip device is further served for drug-associated MTJ toxic or protective efficacy investigations. These results highlight that these interwoven nanofibrous scaffolds with biomimetic "M-type" interface are beneficial for engineered MTJ tissue development, and MTJ-on-a-chip with precise co-culture system indicated their promising potential as in vitro musculoskeletal models for drug development and biological mechanism studies.
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Objective: Compare the spine's stability after laminectomy (LN) and laminoplasty (LP) for two posterior surgeries. Simultaneously, design a new vertebral titanium porous mini plate (TPMP) to achieve firm fixation of the open-door vertebral LP fully. The objective is to enhance the fixation stability, effectively prevent the possibility of "re-closure," and may facilitate bone healing. Methods: TPMP was designed by incorporating a fusion body and porous structures, and a three-dimensional finite element cervical model of C2-T1 was constructed and validated. Load LN and LP finite element models, respectively, and analyze and simulate the detailed processes of the two surgeries. It was simultaneously implanting the TPMP into LP to evaluate its biomechanical properties. Results: We find that the range of motion (ROM) of C4-C5 after LN surgery was greater than that of LP implanted with different plates alone. Furthermore, flexion-extension, lateral bending, and axial rotation reflect this change. More noteworthy is that LN has a much larger ROM on C2-C3 in axial rotation. The ROM of LP implanted with two different plates is similar. There is almost no difference in facet joint stress in lateral bending. The facet joint stress of LN is smaller on C2-C3 and C4-C5, and larger more prominent on C5-C6 in the flexion-extension. Regarding intervertebral disc pressure (IDP), there is little difference between different surgeries except for the LN on C2-C3 in axial rotation. The plate displacement specificity does not significantly differ from LP with vertebral titanium mini-plate (TMP) and LP with TPMP after surgery. The stress of LP with TPMP is larger in C4-C5, C5-C6. Moreover, LP with TMP shows greater stress in the C3-C4 during flexion-extension and lateral bending. Conclusion: LP may have better postoperative stability when posterior approach surgery is used to treat CSM; at the same time, the new type of vertebral titanium mini-plate can achieve almost the same effect as the traditional titanium mini-plate after surgery for LP. In addition, it has specific potential due to the porous structure promoting bone fusion.
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Background: The treatment of patellar tendon injury has always been an unsolved problem, and mechanical characterization is very important for its repair and reconstruction. Elastin is a contributor to mechanics, but it is not clear how it affects the elasticity, viscoelastic properties, and structure of patellar tendon. Methods: The patellar tendons from six fresh adult experimental pigs were used in this study and they were made into 77 samples. The patellar tendon was specifically degraded by elastase, and the regional mechanical response and structural changes were investigated by: (1) Based on the previous study of elastase treatment conditions, the biochemical quantification of collagen, glycosaminoglycan and total protein was carried out; (2) The patellar tendon was divided into the proximal, central, and distal regions, and then the axial tensile test and stress relaxation test were performed before and after phosphate-buffered saline (PBS) or elastase treatment; (3) The dynamic constitutive model was established by the obtained mechanical data; (4) The structural relationship between elastin and collagen fibers was analyzed by two-photon microscopy and histology. Results: There was no statistical difference in mechanics between patellar tendon regions. Compared with those before elastase treatment, the low tensile modulus decreased by 75%-80%, the high tensile modulus decreased by 38%-47%, and the transition strain was prolonged after treatment. For viscoelastic behavior, the stress relaxation increased, the initial slope increased by 55%, the saturation slope increased by 44%, and the transition time increased by 25% after enzyme treatment. Elastin degradation made the collagen fibers of patellar tendon become disordered and looser, and the fiber wavelength increased significantly. Conclusion: The results of this study show that elastin plays an important role in the mechanical properties and fiber structure stability of patellar tendon, which supplements the structure-function relationship information of patellar tendon. The established constitutive model is of great significance to the prediction, repair and replacement of patellar tendon injury. In addition, human patellar tendon has a higher elastin content, so the results of this study can provide supporting information on the natural properties of tendon elastin degradation and guide the development of artificial patellar tendon biomaterials.
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Porous titanium alloy implants with simulated trabecular bone fabricated by 3D printing technology have broad prospects. However, due to the fact that some powder adheres to the surface of the workpiece during the manufacturing process, the surface roughness in direct printing pieces is relatively high. At the same time, since the internal pores of the porous structure cannot be polished by conventional mechanical polishing, an alternative method needs to be found. As a surface technology, plasma polishing technology is especially suitable for parts with complex shapes that are difficult to polish mechanically. It can effectively remove particles and fine splash residues attached to the surface of 3D printed porous titanium alloy workpieces. Therefore, it can reduce surface roughness. Firstly, titanium alloy powder is used to print the porous structure of the simulated trabecular bone with a metal 3D printer. After printing, heat treatment, removal of the supporting structure, and ultrasonic cleaning is carried out. Then, plasma polishing is performed, consisting of adding a polishing electrolyte with the pH set to 5.7, preheating the machine to 101.6 °C, fixing the workpiece on the polishing fixture, and setting the voltage (313 V), current (59 A), and polishing time (3 min). After polishing, the surface of the porous titanium alloy workpiece is analyzed by a confocal microscope, and the surface roughness is measured. Scanning electron microscopy is used to characterize the surface condition of porous titanium. The results show that the surface roughness of the whole porous titanium alloy workpiece changed from Ra (average roughness) = 126.9 µm to Ra = 56.28 µm, and the surface roughness of the trabecular structure changed from Ra = 42.61 µm to Ra = 26.25 µm. Meanwhile, semi-molten powders and ablative oxide layers are removed, and surface quality is improved.
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Ligas , Materiais Biocompatíveis , Próteses e Implantes , Titânio , Porosidade , Pós , Impressão Tridimensional , Propriedades de Superfície , Próteses e Implantes/normas , Osso Esponjoso , Materiais Biocompatíveis/normasRESUMO
Palmitic acid (PA), the most common statured fatty acid in diets, is involved in peripheral as well as central inflammation. The M1 polarization of microglia plays an important role in PA-induced neuroinflammation. However, it is still unclear on the key factor and molecule mechanism of microglial polarization among it. Thus, we investigated whether the release of self-DNA into the cytoplasm of microglia was a consequence of PA treatment, as in aortic endothelial cells and adipocytes. RT-qPCR and immunofluorescence were performed to detect the status of cytosolic DNA and microglial polarization after PA treatment. We found that the content of cytosolic nDNA rather than mtDNA increased after PA treatment and the M1 polarization of microglia was associated with this. Moreover, the knockdown of cGAS in BV2 microglial cells demonstrated that the cGAS-STING pathway is involved in polarization process. Our results revealed that nDNA and cGAS-STING pathway are critically involved in PA-induced microglial M1 polarization. This mechanism may pose a new insight on targeting microglia may be a promising way to mitigate diet-induced early neuroinflammation.
Assuntos
Microglia , Ácido Palmítico , Microglia/metabolismo , Ácido Palmítico/farmacologia , Ácido Palmítico/metabolismo , Células Endoteliais/metabolismo , Citosol/metabolismo , Transdução de Sinais , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , DNA Mitocondrial/metabolismoRESUMO
Objective: To evaluate the biomechanical effects of Poller screws (PS) combined with small-diameter intramedullary nails in the treatment of distal tibial fractures at different locations and on different planes. Methods: Nine finite element (FE) models were used to simulate the placement of the intramedullary nail (IMN) and the PS for distal tibial fractures. Structural stiffness and interfragmentary motion (IFM) through the fracture were investigated to assess the biomechanical effects of the PS. The allowable stress method was used to evaluate the safety of the construct. Results: With the axial load of 500 N, the mean axial stiffness of IMN group was 973.38 ± 95.65 N/mm, which was smaller than that at positions A and B of the coronal group and sagittal group (p < 0.05). The shear IFM of the IMN group was 2.10 ± 0.02 mm, which were smaller than that at positions A and B of the coronal group and sagittal group (p < 0.05). Under physiological load, the stresses of all internal fixation devices and the nail-bone interface were within a safe range. Conclusion: In the treatment of distal tibial fractures, placing the PS in the proximal fracture block can obtain better biomechanical performance. The IMN fixation system can obtain higher structural stiffness and reduce the IFM of the fracture end by adding PS.