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1.
Stem Cell Res Ther ; 15(1): 281, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39227965

RESUMO

BACKGROUND: Primary human hepatocytes (PHHs) are highly valuable for drug-metabolism evaluation, liver disease modeling and hepatocyte transplantation. However, their availability is significantly restricted due to limited donor sources, alongside their constrained proliferation capabilities and reduced functionality when cultured in vitro. To address this challenge, we aimed to develop a novel method to efficiently expand PHHs in vitro without a loss of function. METHODS: By mimicking the in vivo liver regeneration route, we developed a two-step strategy involving the de-differentiation/expansion and subsequent maturation of PHHs to generate abundant functional hepatocytes in vitro. Initially, we applied SiPer, a prediction algorithm, to identify candidate small molecules capable of activating liver regenerative transcription factors, thereby formulating a novel hepatic expansion medium to de-differentiate PHHs into proliferative human hepatic progenitor-like cells (ProHPLCs). These ProHPLCs were then re-differentiated into functionally mature hepatocytes using a new hepatocyte maturation condition. Additionally, we investigated the underlying mechanism of PHHs expansion under our new conditions. RESULTS: The novel hepatic expansion medium containing hydrocortisone facilitated the de-differentiation of PHHs into ProHPLCs, which exhibited key hepatic progenitor characteristics and demonstrated a marked increase in proliferation capacity compared to cells cultivated in previously established expansion conditions. Remarkably, these subsequent matured hepatocytes rivaled PHHs in terms of transcriptome profiles, drug metabolizing activities and in vivo engraftment capabilities. Importantly, our findings suggest that the enhanced expansion of PHHs by hydrocortisone may be mediated through the PPARα signaling pathway and regenerative transcription factors. CONCLUSIONS: This study presents a two-step strategy that initially induces PHHs into a proliferative state (ProHPLCs) to ensure sufficient cell quantity, followed by the maturation of ProHPLCs into fully functional hepatocytes to guarantee optimal cell quality. This approach offers a promising means of producing large numbers of seeding cells for hepatocyte-based applications.


Assuntos
Diferenciação Celular , Hepatócitos , Regeneração Hepática , Humanos , Hepatócitos/metabolismo , Hepatócitos/citologia , Proliferação de Células , Células Cultivadas , Animais , Técnicas de Cultura de Células/métodos
2.
Neural Regen Res ; 2024 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-39104173

RESUMO

Neuronal cell death is a common outcome of multiple pathophysiological processes and a key factor in neurological dysfunction after subarachnoid hemorrhage. Neuronal ferroptosis in particular plays an important role in early brain injury. Bromodomain-containing protein 4, a member of the bromo and extraterminal domain family of proteins, participated in multiple cell death pathways, but the mechanisms by which it regulates ferroptosis remain unclear. The primary aim of this study was to investigate how bromodomain-containing protein 4 affects neuronal ferroptosis following subarachnoid hemorrhage in vivo and in vitro. Our findings revealed that endogenous bromodomain-containing protein 4 co-localized with neurons, and its expression was decreased 48 hours after subarachnoid hemorrhage of the cerebral cortex in vivo. In addition, ferroptosis-related pathways were activated in vivo and in vitro after subarachnoid hemorrhage. Targeted inhibition of bromodomain-containing protein 4 in neurons increased lipid peroxidation and intracellular ferrous iron accumulation via ferritinophagy and ultimately led to neuronal ferroptosis. Using cleavage under targets and tagmentation analysis, we found that bromodomain-containing protein 4 enrichment in the Raf-1 promoter region decreased following oxyhemoglobin stimulation in vitro. Furthermore, treating bromodomain-containing protein 4-knockdown HT-22 cell lines with GW5074, a Raf-1 inhibitor, exacerbated neuronal ferroptosis by suppressing the Raf-1/ERK1/2 signaling pathway. Moreover, targeted inhibition of neuronal bromodomain-containing protein 4 exacerbated early and long-term neurological function deficits after subarachnoid hemorrhage. Our findings suggest that bromodomain-containing protein 4 may have neuroprotective effects after subarachnoid hemorrhage, and that inhibiting ferroptosis could help treat subarachnoid hemorrhage.

3.
Acta Psychol (Amst) ; 248: 104393, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39018783

RESUMO

Collaborative programming is being increasingly used to overcome the difficulties of the individual programming process. In this study, we investigated the effect of collaborative perception on cognitive engagement and learning outcomes in collaborative programming. We used a quasi-experimental research to determine the differences in cognitive engagement and learning outcomes of three groups with different levels of collaborative perception. The findings highlight several important conclusions. First, there were significant differences in cognitive engagement and learning outcomes across collaborative perception groups. Students with high levels of collaborative perception demonstrate more comprehensive and diverse cognitive engagement, resulting in higher learning outcomes compared to those with lower perception. Second, students in the low collaborative perception group had more Clarification-Elaboration cognitive connections, and students in the high collaborative perception group had stronger Clarification-Positioning and Clarification-Verification cognitive connections. Third, collaborative perception positively moderated the relationship between cognitive engagement and learning outcomes. In particular, three cognitive engagement, Clarification, Elaboration, and Positioning, had a greater impact on performance when moderated by collaborative perceptions. These findings have practical implications for educators and course designers, emphasizing the importance of considering students' collaborative perception when forming groups and promoting effective collaborative programming.


Assuntos
Cognição , Comportamento Cooperativo , Aprendizagem , Estudantes , Humanos , Feminino , Estudantes/psicologia , Masculino , Cognição/fisiologia , Aprendizagem/fisiologia , Adulto Jovem , Adulto , Percepção/fisiologia , Adolescente
4.
Vaccines (Basel) ; 12(7)2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39066412

RESUMO

Herpes zoster (HZ) is an infectious disease caused by the reactivation of varicella zoster virus (VZV), with 68% of cases occurring in adults over 50 years of age. HZ/su (Shingrix®) was approved by the Food and Drug Administration in 2017 for the prevention of HZ in individuals ≥ 50 years of age and showed very good protection from HZ. However, due to the use of the adjuvant AS01B, adverse reactions caused by Shingrix are a concern. Aluminum hydroxide is the most commonly used adjuvant and is widely used in a variety of vaccines. We developed a recombinant zoster vaccine (code: LZ901) consisting of a tetramer of VZV glycoprotein E (gE) and a human Fc fusion protein expressed in CHO cells, an immune complex-like molecule that can be adsorbed with an aluminum hydroxide adjuvant. We compared the immunogenicity of LZ901 with that of HZ/su in BALB/c mice. The results showed that LZ901 induced levels of gE-specific IgG antibodies comparable to those induced by HZ/su, and the results of FAMA titers further demonstrated their similar neutralizing antibody abilities. Most importantly, LZ901 induced higher levels of cell-mediated immunity (CMI) (which plays a decisive role in the efficacy of zoster vaccines) than HZ/su in BALB/c mice. The numbers of cytokine-producing T cells in LZ901-vaccinated mice were significantly greater than those in v-vaccinated mice, and the proportions of CD4+ and CD8+ T cells producing at least two types of cytokines in LZ901-vaccinated mice were significantly greater than those in HZ/su-vaccinated mice.

5.
Neurobiol Dis ; 199: 106583, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38942324

RESUMO

After ischemic stroke (IS), secondary injury is intimately linked to endoplasmic reticulum (ER) stress and body-brain crosstalk. Nonetheless, the underlying mechanism systemic immune disorder mediated ER stress in human IS remains unknown. In this study, 32 candidate ER stress-related genes (ERSRGs) were identified by overlapping MSigDB ER stress pathway genes and DEGs. Three Key ERSRGs (ATF6, DDIT3 and ERP29) were identified using LASSO, random forest, and SVM-RFE. IS patients with different ERSRGs profile were clustered into two groups using consensus clustering and the difference between 2 group was further explored by GSVA. Through immune cell infiltration deconvolution analysis, and middle cerebral artery occlusion (MCAO) mouse scRNA analysis, we found that the expression of 3 key ERSRGs were closely related with peripheral macrophage cell ER stress in IS and this was further confirmed by RT-qPCR experiment. These ERS genes might be helpful to further accurately regulate the central nervous system and systemic immune response through ER stress and have potential application value in clinical practice in IS.


Assuntos
Biologia Computacional , Estresse do Retículo Endoplasmático , Aprendizado de Máquina , Humanos , Estresse do Retículo Endoplasmático/genética , Estresse do Retículo Endoplasmático/fisiologia , Camundongos , Animais , Acidente Vascular Cerebral/genética , AVC Isquêmico/genética , AVC Isquêmico/metabolismo , Masculino
6.
Phys Rev Lett ; 132(6): 060601, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38394571

RESUMO

Quantum systems usually feature a rich multilevel structure with promising resources for developing superior quantum technologies compared with their binary counterpart. Single-shot readout of these high-dimensional quantum systems is essential for exploiting their potential. Although there have been various high-spin systems, the single-shot readout of the overall state of high-spin systems remains a challenging issue. Here we demonstrate a reliable single-shot readout of spin qutrit state in a low-temperature solid-state system utilizing a binary readout scheme. We achieve a single-shot readout of an electron spin qutrit associated with a single nitrogen-vacancy center in diamond with an average fidelity of 87.80%. We use this spin qutrit system to verify quantum contextuality, a fundamental test of quantum mechanics. We observe a violation of the noncontextual hidden variable inequality with the developed single-shot readout in contrast to the conventional binary readout. These results pave the way for developing quantum information processing based on spin qutrits.

7.
Natl Sci Rev ; 10(12): nwad100, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37954192

RESUMO

High-sensitivity detection of the microscopic magnetic field is essential in many fields. Good sensitivity and high spatial resolution are mutually contradictory in measurement, which is quantified by the energy resolution limit. Here we report that a sensitivity of 0.5 nT/[Formula: see text] at the nanoscale is achieved experimentally by using nitrogen-vacancy defects in diamond with depths of tens of nanometers. The achieved sensitivity is substantially enhanced by integrating with multiple quantum techniques, including real-time-feedback initialization, dynamical decoupling with shaped pulses and repetitive readout via quantum logic. Our magnetic sensors will shed new light on searching new physics beyond the standard model, investigating microscopic magnetic phenomena in condensed matters, and detection of life activities at the sub-cellular scale.

8.
Proc Natl Acad Sci U S A ; 120(36): e2302145120, 2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37639592

RESUMO

How to illuminate dark matter has become the foremost open question in fundamental science nowadays, which is of great significance in understanding the laws of nature. Exploring exotic interactions beyond the standard model is one of the essential approaches to searching for dark matter particles. Although it has been explored in a variety of lab-scale and tabletop-scale setups over the past years, no such interactions have been observed, and improving the sensitivity significantly becomes of paramount importance, but challenging. Here, we formulate the conception of a spin-mechanical quantum chip compatible with scalable on-chip detectors. Utilizing the prototype chip realized by the integration of a mechanical resonator and a diamond with single nitrogen vacancy at the microscale, the constraints of spin-velocity-dependent interactions have been improved by two orders of magnitude, where there is no evidence for new bosons in the force range below 100 nm, i.e., in the rest-mass window of 2-10 electronvolts. Based on the proof-of-principle experiment, this promising chip can be scaled up to meet the requirements of searching for exotic interactions at preeminent sensitivity. Low-cost and high-yield chip-scale setups will accelerate the process of dark matter exploration, providing a path toward on-chip fundamental physics experiments.

9.
Neuroscience ; 524: 220-232, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37290684

RESUMO

Apolipoprotein E (apoE, protein; APOE, gene), divided into three alleles of E2, E3 and E4 in humans, is associated with the progression of white matter lesion load. However, mechanism evidence has not been reported regarding the APOE genotype in early white matter injury (WMI) under subarachnoid hemorrhage (SAH) conditions. In the present study, we investigated the effects of APOE gene polymorphisms, by constructing microglial APOE3 and APOE4-specific overexpression, on WMI and underlying mechanisms of microglia phagocytosis in a mice model of SAH. A total of 167 male C57BL/6J mice (weight 22-26 g) were used. SAH and bleeding environment were induced by endovascular perforation in vivo and oxyHb in vitro, respectively. Multi-technology approaches, including immunohistochemistry, high throughput sequencing, gene editing for adeno-associated viruses, and several molecular biotechnologies were used to validate the effects of APOE polymorphisms on microglial phagocytosis and WMI after SAH. Our results revealed that APOE4 significantly aggravated the WMI and decreased neurobehavioral function by impairing microglial phagocytosis after SAH. Indicators negatively associated with microglial phagocytosis increased like CD16, CD86 and the ratio of CD16/CD206, while the indicators positively associated with microglial phagocytosis decreased like Arg-1 and CD206. The increased ROS and aggravating mitochondrial damage demonstrated that the damaging effects of APOE4 in SAH may be associated with microglial oxidative stress-dependent mitochondrial damage. Inhibiting mitochondrial oxidative stress by Mitoquinone (mitoQ) can enhance the phagocytic function of microglia. In conclusion, anti-oxidative stress and phagocytosis protection may serve as promising treatments in the management of SAH.


Assuntos
Lesões Encefálicas , Hemorragia Subaracnóidea , Substância Branca , Camundongos , Humanos , Animais , Masculino , Apolipoproteína E4/genética , Apolipoproteína E4/metabolismo , Microglia/metabolismo , Hemorragia Subaracnóidea/genética , Hemorragia Subaracnóidea/metabolismo , Substância Branca/patologia , Camundongos Endogâmicos C57BL , Apolipoproteínas E/genética , Lesões Encefálicas/patologia , Apolipoproteína E3/metabolismo , Fagocitose/genética
11.
Phys Rev Lett ; 130(3): 030601, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36763408

RESUMO

Inevitable interactions with the reservoir largely degrade the performance of entangling gates, which hinders practical quantum computation from coming into existence. Here, we experimentally demonstrate a 99.920(7)%-fidelity controlled-not gate by suppressing the complicated noise in a solid-state spin system at room temperature. We found that the fidelity limited at 99% in previous works results from considering only static classical noise, and, thus, in this work, a complete noise model is constructed by also considering the time dependence and the quantum nature of the spin bath. All noises in the model are dynamically corrected by an exquisitely designed shaped pulse, giving the resulting error below 10^{-4}. The residual gate error is mainly originated from the longitudinal relaxation and the waveform distortion that can both be further reduced technically. Our noise-resistant method is universal and will benefit other solid-state spin systems.

12.
ACS Appl Mater Interfaces ; 14(28): 32218-32226, 2022 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-35816115

RESUMO

Lead-free relaxor ferroelectric ceramics are potential for energy storage applications due to their comprehensive energy storage properties. However, the energy efficiency of many relaxor ceramics is not high enough, leading to high Joule heat during the charge-discharge cycles, thus lowering their energy storage performance. In this work, tantalum (Ta) dopants were introduced into sodium niobate-based relaxor ceramics to improve the resistivity and energy efficiency. The leakage current was reduced by Ta doping, especially at the high electric field. The enhanced resistivity is attributed to the increased bandgap induced by Ta doping. The impedance spectroscopy shows that both the grain and grain boundary resistivities are improved in the high temperature region. As a result, the optimal recoverable energy density and energy efficiency are 6.5 J/cm3 and 94% at 450 kV/cm, respectively. In addition, the energy storage properties exhibit satisfactory temperature stability and cycling reliability. All these merits demonstrate that the Ta modified sodium niobate-based relaxor ceramic a potential candidate for high-power energy storage applications.

13.
Educ Inf Technol (Dordr) ; 27(6): 8265-8288, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35261550

RESUMO

The MOOCs (Massive Open Online Courses) forum carries rich discussion data that contains multi-level cognition-related behavior patterns, which brings the potential for an in-depth investigation into the development trend of the group and individual cognitive presence in discourse interaction. This paper describes a study conducted in the context of an introductory astronomy course on the Chinese MOOCs platform, examining the relationship between discussion pacings (i.e., instructor-paced or learner-paced discussion), cognitive presence, and learning achievements. Using content analysis, lag sequential analysis, logistic regression, and grouped regression approaches, the study analysed the online discussion data collected from the Astronomy Talk course involving 2603 participants who contributed 24,018 posts. The findings of the study demonstrated the significant cognitive sequential patterns, and revealed the significant differences in the distribution of cognitive presence with different discussion pacings and learning achievement groups, respectively. Moreover, we found that the high-achieving learners were mostly in the exploration, integration, and resolution phase, and learner-paced discussion had a greater moderating effect on the relationship between cognitive presence and learning achievements. Based on the findings and discussion, suggestions for improving the learners' cognitive presence and learning achievements in the MOOC environment are discussed.

14.
RNA Biol ; 18(sup2): 866-880, 2021 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-34843419

RESUMO

Subcellular localization of transcripts is highly associated with regulation of gene expression, synthesis of protein, and also the development of the human brain cortex. Although many mechanisms are prevalent in the occurrence of neuroinflammation, the mechanisms based on differences in subcellular localization of transcripts have not been explored. To characterize the dynamic profile of nuclear and cytoplasmic transcripts during the progress of haemorrhage-induced neuroinflammation, we isolated nucleo-cytoplasmic RNA fractions of oxyhaemoglobin (oxy-Hb) treated microglia cells and sequenced both fractions. We discovered that cytoplasmic retained genes were the major forces to maintain the neuroinflammatory microenvironment with 10 hub genes and 40 conserved genes were identified. Moreover, antisense RNA Gm44096 and lincRNA Gm47270, which co-expressed with a crowd of inflammatory genes in the cytoplasm, were discovered as regulatory strategies for sustaining the neuroinflammatory microenvironment. Thus, our study provides a new perspective on understanding haemorrhage-induced neuroinflammation and also reveals a mechanism of lncRNA responsible for maintaining the neuroinflammatory microenvironment.


Assuntos
Núcleo Celular/metabolismo , Microambiente Celular/genética , Citoplasma/metabolismo , Doenças Neuroinflamatórias/etiologia , Transporte de RNA , Animais , Linhagem Celular , Núcleo Celular/genética , Biologia Computacional/métodos , Citoplasma/genética , Modelos Animais de Doenças , Suscetibilidade a Doenças , Perfilação da Expressão Gênica , Ontologia Genética , Hemorragia/complicações , Camundongos , Microglia/metabolismo , Doenças Neuroinflamatórias/metabolismo , RNA Longo não Codificante/genética
15.
Sci Adv ; 7(32)2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34362736

RESUMO

The use of entangled sensors improves the precision limit from the standard quantum limit (SQL) to the Heisenberg limit. Most previous experiments beating the SQL are performed on the sensors that are well isolated under extreme conditions. Here, we demonstrate a sub-SQL interferometer at ambient conditions by using a multispin system, namely, the nitrogen-vacancy (NV) defect in diamond. We achieve two-spin interference with a phase sensitivity of 1.79 ± 0.06 dB beyond the SQL and three-spin interference with a phase sensitivity of 2.77 ± 0.10 dB. Besides, a magnetic sensitivity of 0.87 ± 0.09 dB beyond the SQL is achieved by two-spin interference for detecting a real magnetic field. Particularly, the deterministic and joint initialization of NV negative state, NV electron spin, and two nuclear spins is realized at room temperature. The techniques used here are of fundamental importance for quantum sensing and computing, and naturally applicable to other solid-state spin systems.

16.
Environ Toxicol ; 36(10): 1969-1980, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33073888

RESUMO

Long non-coding RNAs have important roles in the occurrence and progression of various cancers. However, the molecular mechanism of lncRNAs in colorectal cancer (CRC) is not well illustrated. Thus, we used bioinformatics methods to find potential lncRNAs associated with CRC progression, and chose SH3PXD2A-AS1 as a candidate for further analysis. The roles of SH3PXD2A-AS1 in CRC cells were determined by CCK-8, transwell invasion, wound healing and flow cytometry assays. Besides, we established the CRC tumor models in nude mice to study the effect of SH3PXD2A-AS1 on the tumor growth. Based on the ceRNA hypothesis, we used miRDB and miRTarBase websites to identify the SH3PXD2A-AS1-related ceRNA regulatory network, and measured the roles of this network in CRC cells. The results revealed that the expression profiles of SH3PXD2A-AS1 from GEO and TCGA databases showed an aberrant high level in CRC tissues compared with colorectal normal tissues. SH3PXD2A-AS1 over-expression was also found in CRC cells. SH3PXD2A-AS1 knockdown inhibited the CRC cellular proliferation, invasion and migration but induced apoptosis. Besides, SH3PXD2A-AS1 knockdown also suppressed the growth of CRC tumors. Furthermore, SH3PXD2A-AS1 could function as a ceRNA of miR-330-5p. Additionally, UBA2 was proved to be a target gene of miR-330-5p. Moreover, SH3PXD2A-AS1 knockdown downregulated UBA2 expression through sponging miR-330-5p to inactivate the Wnt/ß-catenin signaling pathway, thereby inhibiting the cell growth and promoting apoptosis. Therefore, the SH3PXD2A-AS1/miR-330-5p/UBA2 network could regulate the progression of CRC through the Wnt/ß-catenin pathway. These findings offer new sights for understanding the pathogenesis of CRC and provide potential biomarkers for CRC treatment.


Assuntos
Neoplasias Colorretais , MicroRNAs , RNA Longo não Codificante , Animais , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Neoplasias Colorretais/genética , Regulação Neoplásica da Expressão Gênica , Camundongos , Camundongos Nus , MicroRNAs/genética , RNA Longo não Codificante/genética , Via de Sinalização Wnt
17.
Artigo em Inglês | MEDLINE | ID: mdl-33133218

RESUMO

The gut microbiota is important in metabolism and immune modulation, and compositional disruption of the gut microbiota population is closely associated with inflammation caused by ionizing radiation (IR). Guiqi Baizhu decoction (GQBZD) is a medicinal compound used in traditional Chinese medicine with anti-inflammatory and antioxidation effects, especially in the process of radiotherapy. However, the effect of GQBZD on reducing the damage to the normal immune system in radiotherapy remains unclear. Here, we show that GQBZD reduces body weights, water intake, food intake, diarrhea level and quality of life score, and inflammation and enhances immunity function in rats treated with X-ray radiation. Meanwhile, our data indicate that GQBZD not only reverses IR-induced gut dysbiosis as indicated change of α-diversity and ß-diversity of microbiota, the composition of Desulfovibrio, Bacteroides, and Parabacteroides, except for Roseburia and Lachnoclostridium, but also maintains intestinal barrier integrity and promoting the formation of short-chain fatty acids (SCFAs). GQBZD can also reduce the level of phosphorylation P65 (p-P65). Our results demonstrate that GQBZD can significantly alleviate the inflammatory responses and improve the immune damage against IR, and may be used as prebiotic agents to prevent gut dysbiosis and radiation-related metabolic disorders in radiotherapy.

18.
Cell Cycle ; 19(22): 3195-3207, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33121344

RESUMO

The purpose of this study was to investigate the effects of astragalus polysaccharides (APS) on the proliferation and apoptosis of bone marrow mesenchymal stem cells (BMSCs) induced by X-ray radiation-induced A549 cells bystander effect (RIBE), and to explore their mechanisms. In this study, APS increased the reduced cell proliferation rate induced by RIBE and inhibiting the apoptosis of bystander cells. In terms of mechanism, APS up-regulates the proteins Bcl-2, Bcl-xl, and down-regulates the proteins Bax and Bak, which induces a decrease in mitochondrial membrane potential, which induces the release of Cyt-c and AIF, which leads to caspase-dependent and caspase-independent pathway to cause apoptosis. In addition, we believe that ROS may be the main cause of these protein changes. APS can inhibit the generation of ROS in bystander cells and thus inhibit the activation of the mitochondrial pathway, further preventing cellular damage caused by RIBE.


Assuntos
Apoptose/efeitos dos fármacos , Astragalus propinquus/química , Efeito Espectador/efeitos dos fármacos , Efeito Espectador/efeitos da radiação , Células-Tronco Mesenquimais/metabolismo , Extratos Vegetais/farmacologia , Polissacarídeos/farmacologia , Células A549 , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Cocultura , Regulação para Baixo/efeitos dos fármacos , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Raios X , Proteína X Associada a bcl-2/metabolismo
19.
ACS Appl Mater Interfaces ; 12(29): 32834-32841, 2020 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-32583659

RESUMO

Sodium niobate (NaNbO3)-based lead-free ceramics have been actively studied for energy storage applications because of their antiferroelectric and/or relaxor features achieved in modified systems. The P-E loops of NaNbO3-based ceramics are usually hysteretic because of the existence of a metastable ferroelectric phase at room temperature. In this study, by introducing aliovalent cations and A-site vacancies, the relaxor characteristics are greatly enhanced in (Na1-2xBix)(Nb1-xZrx)O3 ceramics, leading to a high energy storage efficiency of above 90%. In addition, sintering aid CuO and a special ramp-to-spike sintering profile were employed to decrease the sintering temperature and reduce the grain size. The modified ceramic exhibits improved insulating properties and hence a higher breakdown strength, leading to a high recoverable energy density of 4.9 J/cm3 and a high energy efficiency of 88% at 430 kV/cm. The ceramic also exhibits satisfactory temperature stability over a wide temperature range from 25 to 125 °C and charge-discharge performance, making it a promising candidate for high-power dielectric energy storage applications.

20.
Materials (Basel) ; 13(1)2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31906408

RESUMO

Due to the enhanced demand for numerous electrical energy storage applications, including applications at elevated temperatures, dielectric capacitors with optimized energy storage properties have attracted extensive attention. In this study, a series of lead-free strontium bismuth titanate based relaxor ferroelectric ceramics have been successfully synthesized by high temperature solid-state reaction. The ultrahigh recoverable energy storage density of 4.2 J/cm3 under 380 kV/cm, with the high efficiency of 88%, was obtained in the sample with x = 0.06. Of particular importance is that this ceramic composition exhibits excellent energy storage performance over a wide work temperature up to 150 °C, with strong fatigue endurance and fast discharge speed. All these merits demonstrate the studied ceramic system is a potential candidate for high-temperature capacitors as energy storage devices.

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