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1.
Neuroscience ; 560: 397-405, 2024 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-39265802

RESUMO

Auditory spatial attention detection (ASAD) aims to decipher the spatial locus of a listener's selective auditory attention from electroencephalogram (EEG) signals. However, current models may exhibit deficiencies in EEG feature extraction, leading to overfitting on small datasets or a decline in EEG discriminability. Furthermore, they often neglect topological relationships between EEG channels and, consequently, brain connectivities. Although graph-based EEG modeling has been employed in ASAD, effectively incorporating both local and global connectivities remains a great challenge. To address these limitations, we propose a new ASAD model. First, time-frequency feature fusion provides a more precise and discriminative EEG representation. Second, EEG segments are treated as graphs, and the graph convolution and global attention mechanism are leveraged to capture local and global brain connections, respectively. A series of experiments are conducted in a leave-trials-out cross-validation manner. On the MAD-EEG and KUL datasets, the accuracies of the proposed model are more than 9% and 3% higher than those of the corresponding state-of-the-art models, respectively, while the accuracy of the proposed model on the SNHL dataset is roughly comparable to that of the state-of-the-art model. EEG time-frequency feature fusion proves to be indispensable in the proposed model. EEG electrodes over the frontal cortex are most important for ASAD tasks, followed by those over the temporal lobe. Additionally, the proposed model performs well even on small datasets. This study contributes to a deeper understanding of the neural encoding related to human hearing and attention, with potential applications in neuro-steered hearing devices.


Assuntos
Atenção , Percepção Auditiva , Encéfalo , Eletroencefalografia , Humanos , Atenção/fisiologia , Eletroencefalografia/métodos , Encéfalo/fisiologia , Percepção Auditiva/fisiologia , Masculino , Adulto , Feminino , Estimulação Acústica/métodos , Adulto Jovem
2.
Hear Res ; 453: 109104, 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39255528

RESUMO

Auditory spatial attention detection (ASAD) seeks to determine which speaker in a surround sound field a listener is focusing on based on the one's brain biosignals. Although existing studies have achieved ASAD from a single-trial electroencephalogram (EEG), the huge inter-subject variability makes them generally perform poorly in cross-subject scenarios. Besides, most ASAD methods do not take full advantage of topological relationships between EEG channels, which are crucial for high-quality ASAD. Recently, some advanced studies have introduced graph-based brain topology modeling into ASAD, but how to calculate edge weights in a graph to better capture actual brain connectivity is worthy of further investigation. To address these issues, we propose a new ASAD method in this paper. First, we model a multi-channel EEG segment as a graph, where differential entropy serves as the node feature, and a static adjacency matrix is generated based on inter-channel mutual information to quantify brain functional connectivity. Then, different subjects' EEG graphs are encoded into a shared embedding space through a total variation graph neural network. Meanwhile, feature distribution alignment based on multi-kernel maximum mean discrepancy is adopted to learn subject-invariant patterns. Note that we align EEG embeddings of different subjects to reference distributions rather than align them to each other for the purpose of privacy preservation. A series of experiments on open datasets demonstrate that the proposed model outperforms state-of-the-art ASAD models in cross-subject scenarios with relatively low computational complexity, and feature distribution alignment improves the generalizability of the proposed model to a new subject.

3.
Waste Manag ; 187: 119-127, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39003881

RESUMO

Lithium supply risk is increasing and driving rapid progress in lithium recovery schemes from spent lithium-ion batteries (LIBs). In this study, a facile recycling process consisting mainly of reduction roasting and NaHCO3 leaching was adopted to improve lithium recovery. The Li of spent LiNixCoyMn1-x-yO2 powder were converted to Li2CO3 and LiAlO2 with the reduction effect of C and residual Al in the roasting process. NaHCO3 leaching was utilized to selectively dissolve lithium from Li2CO3 and water-insoluble LiAlO2. The activation energy of NaHCO3 leaching was 9.31 kJ∙mol-1 and the leaching of lithium was a diffusion control reaction. More than 95.19 % lithium was leached and recovered as a Li2CO3 product with a purity of 99.80 %. Thus, this approach provides a green path to selective recovery of lithium with good economics.


Assuntos
Fontes de Energia Elétrica , Lítio , Reciclagem , Lítio/química , Reciclagem/métodos , Bicarbonato de Sódio/química
4.
Dalton Trans ; 53(25): 10603-10617, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38855983

RESUMO

Due to their novel spin and valley properties, two-dimensional (2D) ferrovalley materials are expected to be promising candidates for next-generation spintronic and valleytronic devices. However, they are subject to various defects in practical applications. Therefore, the electronic, valley, and magnetic properties may be modified in the presence of the defects. In this work, utilizing first-principles calculations, we systematically studied the effects of defects on the electronic, valley, and magnetic properties of the 2D ferrovalley material VSi2N4. It has been found that C doping, O doping, and N vacancies result in the half-metallic feature, Si vacancies result in the metallic feature, and V vacancies result in a bipolar gapless semiconductor. These defect-induced electronic properties can be effectively tuned by changing defect concentration and layer thickness. Since the impurity bands do not affect the K and K' valleys, valley polarization is well maintained in O-doped and N-defective systems. Importantly, these defects play a crucial role in modifying the magnetic properties of the pristine VSi2N4, especially the magnitude of local magnetic moments and the magnetic anisotropy energy. Detailed analysis of the density of states demonstrates that the variations of the total magnetic moment and magnetic anisotropy energy with biaxial strain are determined by the electronic states near the Fermi level rather than the type of defect, which provides a new understanding of the effects of defects on the magnetic properties of 2D materials. Moreover, the layer thickness can affect the magnetic coupling between defects and surrounding V atoms. Our results offer insight into the electronic, valley, and magnetic properties of VSi2N4 in the presence of various point defects.

5.
J Cell Mol Med ; 28(8): e18285, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38597406

RESUMO

Microglial polarization and associated inflammatory activity are the key mediators of depression pathogenesis. The natural Smilax glabra rhizomilax derivative engeletin has been reported to exhibit robust anti-inflammatory activity, but no studies to date have examined the mechanisms through which it can treat depressive symptoms. We showed that treatment for 21 days with engeletin significantly alleviated depressive-like behaviours in chronic stress social defeat stress (CSDS) model mice. T1-weighted imaging (T1WI), T2-weighted imaging (T2WI) imaging revealed no significant differences between groups, but the bilateral prefrontal cortex of CSDS mice exhibited significant increases in apparent diffusion coefficient and T2 values relative to normal control mice, with a corresponding reduction in fractional anisotropy, while engeletin reversed all of these changes. CSDS resulted in higher levels of IL-1ß, IL-6, and TNF-a production, enhanced microglial activation, and greater M1 polarization with a concomitant decrease in M2 polarization in the mPFC, whereas engeletin treatment effectively abrogated these CSDS-related pathological changes. Engeletin was further found to suppress the LCN2/C-X-C motif chemokine ligand 10 (CXCL10) signalling axis such that adeno-associated virus-induced LCN2 overexpression ablated the antidepressant effects of engeletin and reversed its beneficial effects on the M1/M2 polarization of microglia. In conclusion, engeletin can alleviate CSDS-induced depressive-like behaviours by regulating the LCN2/CXCL10 pathway and thereby altering the polarization of microglia. These data suggest that the antidepressant effects of engeletin are correlated with the polarization of microglia, highlighting a potential avenue for future design of antidepressant strategies that specifically target the microglia.


Assuntos
Antidepressivos , Flavonóis , Glicosídeos , Microglia , Camundongos , Animais , Microglia/metabolismo , Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Depressão/tratamento farmacológico , Depressão/etiologia , Transdução de Sinais
6.
J Neural Eng ; 21(2)2024 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-38588700

RESUMO

Objective. The instability of the EEG acquisition devices may lead to information loss in the channels or frequency bands of the collected EEG. This phenomenon may be ignored in available models, which leads to the overfitting and low generalization of the model.Approach. Multiple self-supervised learning tasks are introduced in the proposed model to enhance the generalization of EEG emotion recognition and reduce the overfitting problem to some extent. Firstly, channel masking and frequency masking are introduced to simulate the information loss in certain channels and frequency bands resulting from the instability of EEG, and two self-supervised learning-based feature reconstruction tasks combining masked graph autoencoders (GAE) are constructed to enhance the generalization of the shared encoder. Secondly, to take full advantage of the complementary information contained in these two self-supervised learning tasks to ensure the reliability of feature reconstruction, a weight sharing (WS) mechanism is introduced between the two graph decoders. Thirdly, an adaptive weight multi-task loss (AWML) strategy based on homoscedastic uncertainty is adopted to combine the supervised learning loss and the two self-supervised learning losses to enhance the performance further.Main results. Experimental results on SEED, SEED-V, and DEAP datasets demonstrate that: (i) Generally, the proposed model achieves higher averaged emotion classification accuracy than various baselines included in both subject-dependent and subject-independent scenarios. (ii) Each key module contributes to the performance enhancement of the proposed model. (iii) It achieves higher training efficiency, and significantly lower model size and computational complexity than the state-of-the-art (SOTA) multi-task-based model. (iv) The performances of the proposed model are less influenced by the key parameters.Significance. The introduction of the self-supervised learning task helps to enhance the generalization of the EEG emotion recognition model and eliminate overfitting to some extent, which can be modified to be applied in other EEG-based classification tasks.


Assuntos
Eletroencefalografia , Emoções , Aprendizado de Máquina Supervisionado , Aprendizado de Máquina Supervisionado/normas , Conjuntos de Dados como Assunto , Humanos
8.
Mol Ther ; 32(5): 1561-1577, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38454607

RESUMO

Inflammation resolution is an essential process for preventing the development of chronic inflammatory diseases. However, the mechanisms that regulate inflammation resolution in psoriasis are not well understood. Here, we report that ANKRD22 is an endogenous negative orchestrator of psoriasiform inflammation because ANKRD22-deficient mice are more susceptible to IMQ-induced psoriasiform inflammation. Mechanistically, ANKRD22 deficiency leads to excessive activation of the TNFRII-NIK-mediated noncanonical NF-κB signaling pathway, resulting in the hyperproduction of IL-23 in DCs. This is due to ANKRD22 being a negative feedback regulator for NIK because it physically binds to and assists in the degradation of accumulated NIK. Clinically, ANKRD22 is negatively associated with IL-23A expression and psoriasis severity. Of greater significance, subcutaneous administration of an AAV carrying ANKRD22-overexpression vector effectively hastens the resolution of psoriasiform skin inflammation. Our findings suggest ANKRD22, an endogenous supervisor of NIK, is responsible for inflammation resolution in psoriasis, and may be explored in the context of psoriasis therapy.


Assuntos
Modelos Animais de Doenças , Interleucina-23 , Psoríase , Transdução de Sinais , Psoríase/metabolismo , Psoríase/patologia , Psoríase/terapia , Psoríase/etiologia , Psoríase/imunologia , Psoríase/genética , Psoríase/induzido quimicamente , Animais , Camundongos , Interleucina-23/metabolismo , Interleucina-23/genética , Humanos , Inflamação/metabolismo , Inflamação/patologia , Camundongos Knockout , Pele/patologia , Pele/metabolismo , Quinase Induzida por NF-kappaB , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , NF-kappa B/metabolismo
9.
Sci Rep ; 14(1): 1070, 2024 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-38212657

RESUMO

SLMO2 is a lipid transporter that transports phosphatidylserine to the interior of mitochondria, also known as PRELID3B, which plays an important role in lipid metabolism. It has also been reported to be involved in the growth process of breast and lung tumors. However, its functions and underlying mechanisms in cancer progress remain elusive, and the potential as pan-cancer biomarker and therapeutic target remains unexplored. Using the TCGA project and GEO database, we performed pan-cancer analysis of SLMO2, which including the expression pattern, prognostic value, mutation landscape, methylation modification, protein-protein interaction network and the relationship between SLMO2 expression and immune infiltration. KEGG enrichment analysis was also performed to predict function and relevant cellular pathways of SLMO2. In addition, proliferation and migration assays were performed to detect the proliferation and metastasis capacity of breast cancer and lung cancer cells. In our study, we found that SLMO2 was overexpressed in pan-cancer and the elevated expression of SLMO2 was correlated with poorer prognosis. SLMO2 mutations were distributed in a variety of tumors and correlated with prognosis. Promoter methylation analysis showed that SLMO2 methylation levels were lower in most tumors compared with normal tissues, while a few tumors showed increased methylation levels of SLMO2. SLMO2 expression was also positively correlated with immune infiltration of MDSCs. Further pathway enrichment analysis indicated that SLMO2 was involved in regulating of cytoplasmic transport and other oncogenic processes. In vitro experiments have shown that SLMO2 promotes the proliferation and migration of breast cancer and lung cancer cells. In conclusion, our findings suggested that SLMO2 was a potential prognostic and immunological marker in pan-cancer. This study suggested a potential strategy for targeting SLMO2 to treat tumors, including manipulating tumor growth or the tumor microenvironment, especially the infiltration of MDSC.


Assuntos
Neoplasias da Mama , Neoplasias Pulmonares , Humanos , Feminino , Prognóstico , Neoplasias da Mama/genética , Neoplasias Pulmonares/genética , Biomarcadores Tumorais/genética , Transporte Biológico , Microambiente Tumoral
10.
Phys Chem Chem Phys ; 26(3): 2341-2354, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38165967

RESUMO

Polarization, as an important characterization of the symmetry breaking systems, has attracted tremendous attention in two-dimensional (2D) materials. Due to their significant symmetry breaking, Janus 2D ferrovalley materials provide a desirable platform to investigate the charge, spin, and valley polarization, as well as their coupling effects. Herein, using first-principles calculations, the polarization properties of charge, spin, and valley in Janus VSiGeZ4 (Z = N, P, and As) monolayers are systematically studied. The mirror symmetry breaking leads to a non-zero dipole moment and surface work function difference, indicating the presence of out-of-plane charge polarization. Magnetic properties calculations demonstrate that VSiGeN4 is a 2D-XY magnet with a Berezinskii-Kosterlitz-Thouless temperature of 342 K, while VSiGeP4 and VSiGeAs4 have an out-of-plane magnetization with a Curie temperature below room temperature. The magnetization can be rotated by applying biaxial strain, allowing manipulation of the spin polarization via nonmagnetic means. The spontaneous valley polarization is predicted to be 46, 49, and 70 meV for VSiGeN4, VSiGeP4, and VSiGeAs4, respectively, whose physical origin can be elucidated by employing the model analysis. In particular, the biaxial strain can induce the valley polarization switching from the valence (conduction) band to conduction (valence) band, but it hardly changes the valley polarization strength. Meanwhile, the valley extremum is transformed from the K' (K) to K (K') points. The present work not only provides an underlying insight into the polarization properties of Janus VSiGeZ4 but also offers a class of promising materials for spintronic and valleytronic devices.

11.
Neurosci Lett ; 818: 137534, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37871827

RESUMO

Music-oriented auditory attention detection (AAD) aims at determining which instrument in polyphonic music a listener is paying attention to by analyzing the listener's electroencephalogram (EEG). However, the existing linear models cannot effectively mimic the nonlinearity of the human brain, resulting in limited performance. Thus, a nonlinear music-oriented AAD model is proposed in this paper. Firstly, an auditory feature and a musical feature are fused to represent musical sources precisely and comprehensively. Secondly, the EEG is enhanced if music stimuli are presented in stereo. Thirdly, a neural network architecture is constructed to capture nonlinear and dynamic interactions between the EEG and auditory stimuli. Finally, the musical source most similar to the EEG in the common embedding space is identified as the attended one. Experimental results demonstrate that the proposed model outperforms all baseline models. On 1-s decision windows, it reaches accuracies of 92.6% and 81.7% under mono duo and trio stimuli, respectively. Additionally, it can be easily extended to speech-oriented AAD. This work can open up new possibilities for studies on both brain neural activity decoding and music information retrieval.


Assuntos
Música , Humanos , Percepção Auditiva , Eletroencefalografia , Encéfalo , Redes Neurais de Computação , Estimulação Acústica/métodos
12.
Cell Rep ; 42(8): 112910, 2023 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-37531255

RESUMO

Amino acid (aa) metabolism is closely correlated with the pathogenesis of psoriasis; however, details on aa transportation during this process are barely known. Here, we find that SLC38A5, a sodium-dependent neutral aa transporter that counter-transports protons, is markedly upregulated in the psoriatic skin of both human patients and mouse models. SLC38A5 deficiency significantly ameliorates the pathogenesis of psoriasis, indicating a pathogenic role of SLC38A5. Surprisingly, SLC38A5 is almost exclusively expressed in dendritic cells (DCs) when analyzing the psoriatic lesion and mainly locates on the lysosome. Mechanistically, SLC38A5 potentiates lysosomal acidification, which dictates the cleavage and activation of TLR7 with ensuing production of pro-inflammatory cytokines such as interleukin-23 (IL-23) and IL-1ß from DCs and eventually aggravates psoriatic inflammation. In summary, this work uncovers an auxiliary mechanism in driving lysosomal acidification, provides inspiring insights for DC biology and psoriasis etiology, and reveals SLC38A5 as a promising therapeutic target for treating psoriasis.


Assuntos
Sistemas de Transporte de Aminoácidos Neutros , Psoríase , Animais , Camundongos , Humanos , Células Dendríticas/metabolismo , Pele/patologia , Psoríase/patologia , Inflamação/patologia , Modelos Animais de Doenças , Lisossomos/patologia , Concentração de Íons de Hidrogênio
13.
Clin Cosmet Investig Dermatol ; 16: 1287-1301, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37223217

RESUMO

Purpose: Psoriasis is a systemic inflammatory disease, and the mechanism that links psoriasis to depression is still elusive. Hence, this study aimed to elucidate the potential pathogenesis of psoriasis and depression comorbidity. Methods: The gene expression profiles of psoriasis (GSE34248, GSE78097 and GSE161683) and depression (GSE39653) were downloaded from the Gene Expression Omnibus (GEO) DataSets. Functional annotation, protein-protein interaction (PPI) network and module construction, and hub gene identification and co-expression analysis were performed, following identification of the common differentially expressed genes (DEGs) of psoriasis and depression. Results: A total of 115 common DEGs (55 up-regulated and 60 down-regulated) were identified between psoriasis and depression. Functional analysis indicated that T cell activation and differentiation were predominantly implicated in the potential pathogenesis of these two diseases. In addition, Th17 cell differentiation and cytokines is closely related to both. Finally, 17 hub genes were screened, including CTLA4, LCK, ITK, IL7R, CD3D, SOCS1, IL4R, PRKCQ, SOCS3, IL23A, PDGFB, PAG1, TGFA, FGFR1, RELN, ITGB5 and TNXB, which re-emphasized the importance of the immune system in psoriasis and depression. Conclusion: Our study reveals the common pathogenesis of psoriasis and depression. These common pathways and hub genes may apply to a molecular screening tool for depression in psoriasis patients, which could help dermatologists optimize patient management in routine care.

14.
Elife ; 122023 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-37104115

RESUMO

Transplantation of neural stem cells (NSCs) has been proved to promote functional rehabilitation of brain lesions including ischemic stroke. However, the therapeutic effects of NSC transplantation are limited by the low survival and differentiation rates of NSCs due to the harsh environment in the brain after ischemic stroke. Here, we employed NSCs derived from human induced pluripotent stem cells together with exosomes extracted from NSCs to treat cerebral ischemia induced by middle cerebral artery occlusion/reperfusion in mice. The results showed that NSC-derived exosomes significantly reduced the inflammatory response, alleviated oxidative stress after NSC transplantation, and facilitated NSCs differentiation in vivo. The combination of NSCs with exosomes ameliorated the injury of brain tissue including cerebral infarction, neuronal death, and glial scarring, and promoted the recovery of motor function. To explore the underlying mechanisms, we analyzed the miRNA profiles of NSC-derived exosomes and the potential downstream genes. Our study provided the rationale for the clinical application of NSC-derived exosomes as a supportive adjuvant for NSC transplantation after stroke.


Assuntos
Isquemia Encefálica , Exossomos , Células-Tronco Pluripotentes Induzidas , AVC Isquêmico , Camundongos , Humanos , Animais , Isquemia Encefálica/terapia , Infarto Cerebral , Diferenciação Celular/fisiologia
15.
Spectrochim Acta A Mol Biomol Spectrosc ; 294: 122558, 2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-36863083

RESUMO

Hydrazine (N2H4) can cause serious damage to human health, while intracellular viscosity is highly associated with many diseases and cellular dysfunctions. Herein, we report the synthesis of a dual-responsive organic molecule-based fluorescent probe with excellent water solubility being capable of detection of N2H4 and viscosity through dual-fluorescence channels in "turn on" manner for both. Besides sensitive detection of N2H4 in aqueous solution with detection limit of 0.135 µM, this probe could be used for vapor N2H4 detection in colorimetric and fluorescent manners. In addition, the probe demonstrated viscosity-dependent fluorescence enhancement behavior, and as high as 150-fold enhancement could be obtained at 95% glycerol aqueous solution. Cell imaging experiment revealed that the probe could be used for the discriminating of living and dead cells.


Assuntos
Sondas Moleculares , Água , Humanos , Viscosidade , Espectrometria de Fluorescência/métodos , Corantes Fluorescentes , Hidrazinas , Células HeLa
16.
Small ; 19(17): e2206982, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36703527

RESUMO

Intracerebral hemorrhage (ICH) remains a significant cause of morbidity and mortality around the world, and surgery is still the most direct and effective way to remove ICH. However, the potential risks brought by surgery, such as normal brain tissue damage, post-operative infection, and difficulty in removing deep hematoma, are still the main problems in the surgical treatment of ICH. Activation of the peroxisome proliferator-activated receptor gamma (PPARγ) is reported to show a good therapeutic effect in hematoma clearance. Herein, a magnetic targeting nanocarrier loaded with a PPARγ agonist (15d-PGJ2-MNPs) is synthesized, which could be magnetically targeted and enriched in the area of the hematoma after intravenous injection. Subsequent application of focusing ultrasound (FUS) could enhance drug diffusion, which activates the PPARγ receptors on macrophages around the hematoma for better hematoma clearance. The 15d-PGJ2-MNP treatment alleviates brain injury, accelerates hematoma clearance, attenuates neuroinflammation, reduces brain edema and significantly improves the deficits in sensory and motor function and spatial learning ability in the ICH mouse model. This work proposes an effective magnetic targeting plus FUS method to treat ICH, highlighting its great potential in the treatment of hemorrhagic stroke.


Assuntos
Hemorragia Cerebral , PPAR gama , Camundongos , Animais , PPAR gama/agonistas , PPAR gama/metabolismo , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/terapia , Hemorragia Cerebral/complicações , Encéfalo/metabolismo , Hematoma/terapia , Hematoma/tratamento farmacológico , Modelos Animais de Doenças , Fenômenos Magnéticos
17.
Materials (Basel) ; 15(18)2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36143644

RESUMO

The effect of target phosphorus (P) content on the precipitates, microstructure, texture, magnetic properties, and mechanical properties of low-carbon (C) and low-silicon (Si) non-oriented electrical steel (NOES) was investigated and the influence mechanism was clarified. The results indicate that the precipitates in the steels are mainly aluminum (Al)-manganese (Mn)-Si-bearing complex nitrides ((Al,Si,Mn)xNy) and P-bearing complex nitrides ((Al,Si,Mn)xNy-P). Increasing target phosphorus content in the steels decreases (Al,Si,Mn)xNy, and increases (Al,Si,Mn)xNy-P. The number density of the precipitates is the lowest, and the average size of the precipitates and grain size of the finished steel is the largest in the samples with target P content at the 0.14% level (0.14%P-targeted). The average grain size and microstructure homogeneity of the steels are influenced by the addition of phosphorus. The content of the {111}<112> component decreases, and the favorable texture increases after phosphorus is added to the steel. The magnetic induction of the steel is improved. Grain refinement and microstructure inhomogeneity lead to an iron loss increase after target phosphorus content increases in the steel. The best magnetic induction B50 is 1.765 T in the 0.14%P-targeted samples. The tensile strength and yield strength are improved owing to solid solution strengthening and the grain refinement effect of phosphorus added to the steels.

18.
Adv Sci (Weinh) ; 9(30): e2201069, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36026580

RESUMO

Gas-mediated sonodynamic therapy (SDT) has the potential to become an effective strategy to improve the therapeutic outcome and survival rate of cancer patients. Herein, titanium sulfide nanosheets (TiSX NSs) are prepared as cascade bioreactors for sequential gas-sonodynamic cancer therapy. TiSX NSs themselves as hydrogen sulfide (H2 S) donors can burst release H2 S gas. Following H2 S generation, TiSX NSs are gradually degraded to become S-defective and partly oxidized into TiOX on their surface, which endows TiSX NSs with high sonodynamic properties under ultrasound (US) irradiation. In vitro and in vivo experiments show the excellent therapeutic effects of TiSX NSs. In detail, large amounts of H2 S gas and reactive oxygen species (ROS) can simultaneously inhibit mitochondrial respiration and ATP synthesis, leading to cancer cell apoptosis. Of note, H2 S gas also plays important roles in modulating and activating the immune system to effectively inhibit pulmonary metastasis. Finally, the metabolizable TiSX NSs are excreted out of the body without inducing any significant long-term toxicity. Collectively, this work establishes a cascade bioreactor of TiSX NSs with satisfactory H2 S release ability and excellent ROS generation properties under US irradiation for programmed gas-sonodynamic cancer therapy.


Assuntos
Sulfeto de Hidrogênio , Neoplasias , Humanos , Espécies Reativas de Oxigênio/metabolismo , Reatores Biológicos , Trifosfato de Adenosina
19.
Bioact Mater ; 18: 569-582, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35845318

RESUMO

Spinal cord regeneration after a spinal cord injury (SCI) remains a difficult challenge due to the complicated inflammatory microenvironment and neuronal damage at the injury sites. In this study, retinoic acid (RA) and curcumin (Cur) were co-loaded with bovine serum albumin (BSA) self-assembly to obtain RA@BSA@Cur nanoparticles (NPs) for SCI treatment. Cur, as an antioxidant drug, facilitated reactive oxygen species (ROS) scavenging, and decreased the amount of inflammatory factors secreted by macrophages, while RA could enhance neurite extensions and neural differentiation. The constructed RA@BSA@Cur NPs not only induced polarization of macrophages toward pro-regenerative phenotypes and markedly reduced the inflammatory response of macrophages or microglia, but also increased neurite length in PC12 cells and neuronal differentiation of bone marrow mesenchymal stem cells, improved the differentiation of neural stem cells (NSCs) into ß3-tubulin+ neurons, and reversed the pro-astrocyte differentiation effect of inflammatory cytokines on NSCs. In vivo experiments revealed that RA@BSA@Cur NPs regulated the phenotypic polarization of macrophages, inhibited the release of inflammatory mediators, promoted functional neuron regeneration and motor function, and further inhibited scar tissue formation. This study highlighted that the BSA-based biomimetic nanomaterials could be used as ROS scavengers and nerve regeneration promoters for treating SCI.

20.
Theranostics ; 12(8): 3834-3846, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35664066

RESUMO

Rationale: Oxidative stress, resulting from excessive reactive oxygen species (ROS), plays an important role in the initiation and progression of inflammatory bowel disease (IBD). Therefore, developing novel strategies to target the disease location and treat inflammation is urgently needed. Methods: Herein, we designed and developed a novel and effective antioxidant orally-administered nanoplatform based on simulated gastric fluid (SGF)-stabilized titanium carbide MXene nanosheets (Ti3C2 NSs) with excellent biosafety and multiple ROS-scavenging abilities for IBD therapy. Results: This broad-spectrum and efficient ROS scavenging performance was mainly relied on the strong reducibility of Ti-C bound. Intracellular ROS levels confirmed that Ti3C2 NSs could efficiently eliminate excess ROS against oxidative stress-induced cell damage. Following oral administration, negatively-charged Ti3C2 NSs specifically adsorbed onto the positively-charged inflamed colon tissue via electrostatic interaction, leading to efficient therapy of dextran sulfate sodium salt (DSS)-induced colitis. The therapeutic mechanism mainly attributed to decreased ROS levels and pro-inflammatory cytokine secretion, and increased M2-phenotype macrophage infiltration and anti-inflammatory cytokine secretion, efficiently inhibiting inflammation and alleviating colitis symptoms. Due to their excellent ROS-scavenging performance, Ti3C2-based woundplast also promoted skin wound healing and functional vessel formation. Conclusions: Our study introduces redox-mediated antioxidant MXene nanoplatform as a novel type of orally administered nanoagents for treating IBD and other inflammatory diseases of the digestive tract.


Assuntos
Colite , Doenças Inflamatórias Intestinais , Animais , Anti-Inflamatórios/uso terapêutico , Antioxidantes/uso terapêutico , Colite/induzido quimicamente , Colite/tratamento farmacológico , Citocinas/uso terapêutico , Sulfato de Dextrana/efeitos adversos , Modelos Animais de Doenças , Inflamação/tratamento farmacológico , Doenças Inflamatórias Intestinais/tratamento farmacológico , Espécies Reativas de Oxigênio/metabolismo , Titânio
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