Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
1.
Mikrochim Acta ; 190(1): 39, 2022 12 30.
Artigo em Inglês | MEDLINE | ID: mdl-36585487

RESUMO

Zeolitic imidazolate framework (ZIF-8) base-aptamer "gate-lock" biomaterial probes have been synthesized for monitoring intracellular deoxynivalenol (DON) and cytochrome c (cyt c) levels. The aptamer and organic fluorescent dye were regarded as a recognition element and a sensing element, respectively. In the presence of DON, the aptamers of DON and cyt c were specifically bound with the DON and induced cyt c, leading to the dissociation of aptamers from the porous surface of the probes. The gate was subsequently opened to release methylene blue (MB) and Rhodamine 6G (Rh6G), and their fluorescence (emission of MB at 700 nm and Rh6G at 550 nm) significantly recovered within 6 h. Cell imaging successfully monitored the exposure of DON and the biological process of cyt c discharge triggered by the activation of the DON-induced apoptosis pathway. In addition, the response between DON and cyt c was observed during the apoptosis process, which is of high significance for the comprehensive and systematic development of mycotoxins cytotoxicity.


Assuntos
Aptâmeros de Nucleotídeos , Tricotecenos , Zeolitas , Citocromos c/metabolismo , Tricotecenos/toxicidade
2.
Acta Biochim Biophys Sin (Shanghai) ; 53(12): 1650-1661, 2021 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-34687203

RESUMO

Papillary thyroid cancer (PTC) usually has favorable prognosis; however, distant metastasis is a leading cause of death associated with PTC. MicroRNA-99a-3p (miR-99a-3p) is a member of the miR-99 family that is shown to be a tumor suppressor in various human cancers including the anaplastic thyroid cancer, another type of thyroid cancer. The Cancer Genome Atlas database and our previous study reported that miR-99a-3p is downregulated in human PTC tissues as well as human papillary thyroid carcinoma B-CPAP and TPC-1 cell lines. However, its pathological role in PTC remains unclear, especially its impact on PTC metastasis. In the present study, the role of miR-99a-3p in PTC metastasis was molecularly evaluated in in vitro and in vivo models. Our functional study revealed that overexpressing miR-99a-3p significantly suppresses epithelial-mesenchymal transition (EMT) and anoikis resistance as well as migration and invasion of B-CPAP and TPC-1 cells. The mechanical study indicated that glucose-regulated protein 94 (GRP94) is the direct target of miR-99a-3p. Moreover, GRP94 overexpression reverses the inhibitory effect of miR-99a-3p on PTC metastasis. In addition, the miR-99a-3p/GRP94 axis exerts its effect via inhibiting the expression and cytoplasmic relocation of integrin 2α (ITGA2). Furthermore, in vivo experiments confirmed that miR-99a-3p significantly inhibits tumor growth and lung metastasis in PTC xenograft mice. Overall, our findings suggested that the miR-99a-3p/GRP94/ITGA2 axis may be a novel therapeutic target for the prevention of PTC metastasis.


Assuntos
Integrina alfa2/metabolismo , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Câncer Papilífero da Tireoide/genética , Neoplasias da Glândula Tireoide/genética , Animais , Anoikis/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Regulação para Baixo , Transição Epitelial-Mesenquimal/genética , Feminino , Xenoenxertos/metabolismo , Humanos , Camundongos Nus , Metástase Neoplásica/genética , Câncer Papilífero da Tireoide/metabolismo , Câncer Papilífero da Tireoide/patologia , Neoplasias da Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/patologia
3.
Mol Cancer ; 18(1): 110, 2019 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-31228940

RESUMO

BACKGROUND: METTL3 is known to be involved in all stages in the life cycle of RNA. It affects the tumor formation by the regulation the m6A modification in the mRNAs of critical oncogenes or tumor suppressors. In bladder cancer, METTL3 could promote the bladder cancer progression via AFF4/NF-κB/MYC signaling network by an m6A dependent manner. Recently, METTL3 was also found to affect the m6A modification in non-coding RNAs including miRNAs, lincRNAs and circRNAs. However, whether this mechanism is related to the proliferation of tumors induced by METTL3 is not reported yet. METHODS: Quantitative real-time PCR, western blot and immunohistochemistry were used to detect the expression of METTL3 in bladder cancer. The survival analysis was adopted to explore the association between METTL3 expression and the prognosis of bladder cancer. Bladder cancer cells were stably transfected with lentivirus and cell proliferation and cell cycle, as well as tumorigenesis in nude mice were performed to assess the effect of METTL3 in bladder cancer. RNA immunoprecipitation (RIP), co-immunoprecipitations and RNA m6A dot blot assays were conducted to confirm that METTL3 interacted with the microprocessor protein DGCR8 and modulated the pri-miR221/222 process in an m6A-dependent manner. Luciferase reporter assay was employed to identify the direct binding sites of miR221/222 with PTEN. Colony formation assay and CCK8 assays were conducted to confirm the function of miR-221/222 in METTL3-induced cell growth in bladder cancer. RESULTS: We confirmed the oncogenic role of METTL3 in bladder cancer by accelerating the maturation of pri-miR221/222, resulting in the reduction of PTEN, which ultimately leads to the proliferation of bladder cancer. Moreover, we found that METTL3 was significantly increased in bladder cancer and correlated with poor prognosis of bladder cancer patients. CONCLUSIONS: Our findings suggested that METTL3 may have an oncogenic role in bladder cancer through interacting with the microprocessor protein DGCR8 and positively modulating the pri-miR221/222 process in an m6A-dependent manner. To our knowledge, this is the first comprehensive study that METTL3 affected the tumor formation by the regulation the m6A modification in non-coding RNAs, which might provide fresh insights into bladder cancer therapy.


Assuntos
Adenosina/análogos & derivados , Metiltransferases/metabolismo , MicroRNAs/genética , Neoplasias da Bexiga Urinária/patologia , Adenosina/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Metiltransferases/genética , Camundongos , Transplante de Neoplasias , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Proteínas de Ligação a RNA/metabolismo , Análise Serial de Tecidos , Regulação para Cima , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/metabolismo
4.
Mol Cancer ; 17(1): 19, 2018 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-29386015

RESUMO

BACKGROUND: Circ-ITCH is a circRNA generated from several exons of itchy E3 ubiquitin protein ligase (ITCH) and tumor suppressor served as a sponge for certain miRNAs targeting their parental transcripts of ITCH. However, the role of circ-ITCH in bladder cancer (BCa) was not reported. In the present study, we investigated the role of circ-ITCH in BCa. METHODS: Quantitative real-time PCR was used to detect the expression of circ-ITCH and survival analysis was adopted to explore the association between circ-ITCH expression and the prognosis of BCa. BCa cells were stably transfected with lentivirus approach and cell proliferation, migration, invasion, cell cycle and cell apoptosis, as well as tumorigenesis in nude mice were performed to assess the effect of circ-ITCH in BCa. Biotin-coupled probe pull down assay, Biotin-coupled miRNA capture, Fluorescence in situ hybridization and Luciferase reporter assay were conducted to confirm the relationship between the circ-ITCH and the microRNA. RESULTS: In the present study, we found that circ-ITCH, is down-regulated in BCa tissues and cell lines. BCa patients with low circ-ITCH expression had shortened survival. Enforced- expression of circ-ITCH inhibited cells proliferation, migration, invasion and metastasis both in vitro and in vivo. Mechanistically, we demonstrated that circ-ITCH up-regulates the expression of miR-17 and miR-224 target gene p21 and PTEN through 'sponging' miR-17 and miR-224, which suppressed the aggressive biological behaviors of BCa. CONCLUSIONS: circ-ITCH acts as a tumor suppressor by a novel circ-ITCH/miR-17, miR-224/p21, PTEN axis, which may provide a potential biomarker and therapeutic target for the management of BCa.


Assuntos
MicroRNAs/genética , PTEN Fosfo-Hidrolase/genética , RNA , Proteínas Repressoras/genética , Ubiquitina-Proteína Ligases/genética , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia , Idoso , Idoso de 80 Anos ou mais , Animais , Apoptose/genética , Linhagem Celular Tumoral , Modelos Animais de Doenças , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Xenoenxertos , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Prognóstico , RNA/sangue , RNA Circular , Neoplasias da Bexiga Urinária/sangue , Neoplasias da Bexiga Urinária/mortalidade
5.
Cell Physiol Biochem ; 46(4): 1606-1616, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29694981

RESUMO

BACKGROUND/AIMS: CircRNAs regulate gene expression in different malignancies. However, the role of Cdr1as in the tumourigenesis of bladder cancer and its potential mechanisms remain unknown. METHODS: qRT-PCR was used to detect Cdr1as and target miRNA expression in bladder cancer tissues and cell lines. Biological functional experiments were performed to detect the effects of Cdr1as on the biological behaviour of bladder cancer cells in vivo and in vitro. Bioinformatic analysis was utilised to predict potential miRNA target sites on Cdr1as. Ago2 RNA binding protein immunoprecipitation assay, RNA antisense purification assay, biotin pull down assay and RNA FISH were performed to detect the interaction between Cdr1as and target miRNAs. Western blot was used to determine the expression level of p21 in bladder cancer cells. RESULTS: Cdr1as was significantly down-regulated in bladder cancer tissues compared with adjacent normal tissues. Overexpression of Cdr1as inhibited the proliferation, invasion and migration of bladder cancer cells in vitro and slowed down tumour growth in vivo. Cdr1as sponged multiple miRNAs in bladder cancer. Moreover, Cdr1as directly bound to miR-135a and inhibited its activity in bladder cancer. CONCLUSION: Cdr1as is down-regulated and sponges multiple miRNAs in bladder cancer. It exerts anti-oncogenic functions by sponging microRNA-135a.


Assuntos
MicroRNAs/metabolismo , RNA Longo não Codificante/metabolismo , Neoplasias da Bexiga Urinária/patologia , Animais , Antagomirs/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Feminino , Humanos , Hibridização in Situ Fluorescente , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , RNA Longo não Codificante/genética , Transplante Heterólogo , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/metabolismo
6.
Cell Physiol Biochem ; 41(3): 921-932, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28222430

RESUMO

BACKGROUND/AIMS: MicroRNA-218 (miR-218) is down-regulated in many malignancies that have been implicated in the regulation of diverse processes in cancer cells. However, the involvement of miR-218 in chemo-sensitivity to cisplatin and the precise mechanism of this action remained unknown in bladder cancer. METHODS: qRT-PCR was used to detect miR-218 and its target Glut1 expression in bladder cancer cell lines T24 and EJ. CCK-8 method was utilized to measure the cell viability. IC 50 was calculated via a probit regression model. Glut1 was detected by western blotting for analysis of potential mechanism. Luciferase reporter assay was utilized to validate Glut1 as a direct target gene of miR-218. The intracellular level of GSH and ROS were determined using a commercial colorimetric assay kit and 2', 7'-dichlorodihydro-fluorescein diacetate, respectively. RESULTS: Over-expression of miR-218 significantly reduced the rate of glucose uptake and total level of GSH and enhanced the chemo-sensitivity of bladder cancer to cisplatin. Mechanistically, Glut1 was found to be a direct and functional target of miR-218. Up-regulation of Glut1 could restore chemo-resistance in T24 and EJ cells. On the contrary, knockdown of Glut1 could generate a similar effect as up-regulating the expression of miR-218. CONCLUSIONS: MiR-218 increases the sensitivity of bladder cancer to cisplatin by targeting Glut1. Restoration of miR-218 and repression of glut1 may provide a potential strategy to restore chemo-sensitivity in bladder cancer.


Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , Células Epiteliais/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Transportador de Glucose Tipo 1/genética , MicroRNAs/genética , Sequência de Bases , Sítios de Ligação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Genes Reporter , Glucose/antagonistas & inibidores , Glucose/metabolismo , Transportador de Glucose Tipo 1/antagonistas & inibidores , Transportador de Glucose Tipo 1/metabolismo , Glutationa/agonistas , Glutationa/metabolismo , Humanos , Concentração Inibidora 50 , Luciferases/genética , Luciferases/metabolismo , MicroRNAs/agonistas , MicroRNAs/metabolismo , Transdução de Sinais , Bexiga Urinária/efeitos dos fármacos , Bexiga Urinária/metabolismo , Bexiga Urinária/patologia
7.
Nanomaterials (Basel) ; 14(3)2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38334539

RESUMO

The reactivity of Al nanoparticles is significantly higher than that of micron Al particles, and the thermal reaction properties exhibit notable distinctions. Following the previous studies on micron Al particles, the shell-breaking response of Al nanoparticles under vacuum conditions was analyzed using COMSOL simulation. Relationships between thermal stabilization time, shell-breaking cause, shell-breaking response time, and particle size were obtained, and a systematic analysis of the differences between micrometer and nanometer-sized particles was conducted. The results indicate that the thermal stabilization time of both micrometer and nanometer particles increases with the enlargement of particle size. The stress generated by heating Al nanoparticles with sizes ranging from 25-100 nm is insufficient to rupture the outer shell. For particles within the size range of 200 nm to 70 µm, the primary cause of shell-breaking is compressive stress overload, while particles in the range of 80-100 µm experience shell rupture primarily due to tensile stress overload. These results provide an important basis for understanding the shell-breaking mechanism of microns and nanoparticles of Al and studying the oxidation mechanism.

8.
Sci Rep ; 14(1): 4710, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38409463

RESUMO

A rotary motor combined with fibrous string demonstrates excellent performance because it is powerful, lightweight, and prone to large strokes; however, the stiffness range and force-generating capability of twisted string transmission systems are limited. Here, we present a variable stiffness artificial muscle generated by impregnating shear stiffening gels (STGs) into a twisted string actuator (TSA). A high twisting speed produces a large impact force and causes shear stiffening of the STG, thereby improving the elasticity, stiffness, force capacity, and response time of the TSA. We show that at a twisting speed of 4186 rpm, the elasticity of an STG-TSA reached 30.92 N/mm, whereas at a low twisting speed of 200 rpm, it was only 10.51 N/mm. In addition, the STG-TSA exhibited a more prominent shear stiffening effect under a high stiffness load. Our work provides a promising approach for artificial muscles to coactivate with human muscles to effectively compensate for motion.

9.
ACS Appl Mater Interfaces ; 15(1): 591-598, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36542734

RESUMO

Encoded microparticles (EMPs) have shown demonstrative value for multiplexed high-throughput bioassays such as drug discovery and diagnostics. Herein, we propose for the first time the incorporation of thermally activated delayed fluorescence (TADF) dyes with low-cost, heavy metal-free, and long-lived luminescence properties into polymer matrices via a microfluidic droplet-facilitated assembly technique. Benefiting from the uniform droplet template sizes and polymer-encapsulated structures, the resulting composite EMPs are highly monodispersed, efficiently shield TADF dyes from singlet oxygen, well preserve TADF emission, and greatly increase the delayed fluorescence lifetime. Furthermore, by combining with phase separation of polymer blends in the drying droplets, TADF dyes with distinct luminescent colors can be spatially separated within each EMP. It eliminates optical signal interference and generates multiple fluorescence colors in a compact system. Additionally, in vitro studies reveal that the resulting EMPs show good biocompatibility and allow cells to adhere and grow on the surface, thereby making them promising optically EMPs for biolabeling.


Assuntos
Micropartículas Derivadas de Células , Corantes Fluorescentes , Luminescência , Polímeros
10.
Chemosphere ; 312(Pt 1): 137171, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36370755

RESUMO

Bisphenol A (BPA), an important environmental pollutant, is known to damage reproductive development. However, the underlying epigenetic mechanism in Leydig cells during BPA exposure has not been explored in detail. In this study, TM3 Leydig cells were treated with BPA (0, 20, 40 and 80 µM) for 72 h. The differentially expressed TET1 cell model was constructed to explore the mechanism of BPA-induced cytotoxicity. Results showed that BPA exposure significantly inhibited cell viability and increased apoptosis of TM3 Leydig cells. Meanwhile, the mRNA of TET1, Cav3.2 and Cav3.3 decreased significantly with the increase of BPA exposure. Importantly, TET1 significantly promoted proliferation of TM3 Leydig cells and inhibited apoptosis. Differentially expressed TET1 significantly affected BPA-induced toxicity in TM3 Leydig cells. Notably, TET1 elevated the mRNA levels of Cav3.2 and Cav3.3. MeDIP and hMeDIP confirmed that TET1 regulated the expression of Cav3.3 through DNA hydroxymethylation. Our study firstly presented that TET1 participated in BPA-induced toxicity in TM3 Leydig cells through regulating Cav3.3 hydroxymethylation modification. These findings suggest that TET1 acts as a potential epigenetic marker for reproductive toxicity induced by BPA exposure and may provide a new direction for the research on male reproductive damage.


Assuntos
Compostos Benzidrílicos , Células Intersticiais do Testículo , Masculino , Humanos , Compostos Benzidrílicos/metabolismo , Fenóis/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
11.
Environ Pollut ; 321: 121144, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36702435

RESUMO

Bisphenol S (BPS) causes reproductive adverse effects on humans and animals. However, the detailed mechanism is still unclear. This research aimed to clarify the role of RNA binding protein YTHDF1 in Leydig cell damage induced by BPS. The mouse TM3 Leydig cells were exposed to BPS of 0, 20, 40, and 80 µmol/L for 72 h. Results showed that TM3 Leydig cells apoptosis rate markedly increased in BPS exposure group. Meanwhile, the apoptosis-related molecule BCL2 protein level decreased significantly, and Caspase9, Caspase3, and BAX increased significantly. Moreover, the cell cycle was blocked in the G1/S phase, CDK2 and CyclinE1 were considerably down-regulated in BPS exposure groups, and the protein level of RNA binding protein YTHDF1 decreased sharply. Furthermore, after overexpression of YTHDF1, the cell viability significantly increased, and the apoptosis rate significantly decreased in TM3 Leydig cells. In the meantime, BCL2, CDK2, and CyclinE1 were significantly up-regulated, and BAX, Caspase9, and Caspase3 were significantly down-regulated. Conversely, interference with YTHDF1 decreased cell proliferation and promoted apoptosis. Importantly, overexpression of YTHDF1 alleviated the cell viability decrease induced by BPS, and interference with YTHDF1 exacerbated the situation. RIP assays showed that the binding of YTHDF1 to CDK2, CyclinE1, and BCL2 significantly increased after overexpressing YTHDF1. Collectively, our study suggested that YTHDF1 plays an essential role in BPS-induced TM3 Leydig cell damage by regulating CDK2-CyclinE1 and BCL2 mitochondrial pathway at the translational level.


Assuntos
Células Intersticiais do Testículo , Fenóis , Animais , Humanos , Masculino , Camundongos , Apoptose , Proteína X Associada a bcl-2/metabolismo , Quinase 2 Dependente de Ciclina/metabolismo , Fenóis/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/farmacologia
12.
Environ Pollut ; 325: 121393, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36878272

RESUMO

Studies have shown that Bisphenol F (BPF) as an emerging bisphenol pollutant also has caused many hazards to the reproductive systems of humans and animals. However, its specific mechanism is still unclear. The mouse TM3 Leydig cell was used to explore the mechanism of BPF-induced reproductive toxicity in this study. The results showed BPF (0, 20, 40 and 80 µM) exposure for 72 h significantly increased cell apoptosis and decreased cell viability. Correspondingly, BPF increased the expression of P53 and BAX, and decreased the expression of BCL2. Moreover, BPF significantly increased the intracellular ROS level in TM3 cells, and significantly decreased oxidative stress-related molecule Nrf2. BPF decreased the expression of FTO and YTHDF2, and increased the total cellular m6A level. ChIP results showed that AhR transcriptionally regulated FTO. Differential expression of FTO revealed that FTO reduced the apoptosis rate of BPF-exposed TM3 cells and increased the expression of Nrf2, MeRIP confirmed that overexpression of FTO reduced the m6A of Nrf2 mRNA. After differential expression of YTHDF2, it was found that YTHDF2 enhanced the stability of Nrf2, and RIP assay showed that YTHDF2 was bound to Nrf2 mRNA. Nrf2 agonist enhanced the protective effect of FTO on TM3 cells exposure to BPF. Our study is the first to demonstrate that AhR transcriptionally regulated FTO, and then FTO regulated Nrf2 in a m6A-modified manner through YTHDF2, thereby affecting apoptosis in BPF-exposed TM3 cells to induce reproductive damage. It provides new insights into the importance of FTO-YTHDF2-Nrf2 signaling axis in BPF-induced reproductive toxicity and provided a new idea for the prevention of male reproductive injury.


Assuntos
Células Intersticiais do Testículo , Fator 2 Relacionado a NF-E2 , Animais , Masculino , Camundongos , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Células Intersticiais do Testículo/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/farmacologia
13.
Polymers (Basel) ; 14(7)2022 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-35406299

RESUMO

A family of half-titanocene complexes bearing π,π-stacked aryloxide ligands and their catalytic performances towards ethylene homo-/co- polymerizations were disclosed herein. All the complexes were well characterized, and the intermolecular π,π-stacking interactions could be clearly identified from single crystal X-ray analysis, in which a stronger interaction could be reflected for aryloxides bearing bigger π-systems, e.g., pyrenoxide. Due to the formation of such interactions, these complexes were able to highly catalyze the ethylene homopolymerizations and copolymerization with 1-hexene comonomer, even without any additiveson the aryloxide group, which showed striking contrast to other half-titanocene analogues, implying the positive influence of π,π-stacking interaction in enhancing the catalytic performances of the corresponding catalysts. Moreover, it was found that addition of external pyrene molecules was capable of boosting the catalytic efficiency significantly, due to the formation of a stronger π,π-stacking interaction between the complexes and pyrene molecules.

14.
Chempluschem ; 87(11): e202200249, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36357010

RESUMO

Inspired by the formation of microspheres by hexachlorocyclotriphosphazene and 4, 4'-sulfonyldiphenol, polyphosphazene-functionalized microspheres were developed. Benefits from the supported supper basic phosphazene, the yield exceeded 99 % at room temperature in the manner of second-order reaction kinetics toward Knoevenagel reaction and was still maintained at 99 % after 16 runs. In the experimental temperature from 0 °C to 90 °C, the yield increased from 92 % to 99 %, reflecting that the catalyst had strong applicability under mild conditions. This behavior was conducive to energy conservation. Meanwhile, simple separation and recovery further enhanced this advantage. In addition, the catalyst was also found to be insensitive to aqueous solution or organic solvents such as toluene, THF, EtOH and CH3 CN. This property gave the Knoevenagel reaction a vast choice. All these features exhibit that this novel catalyst is an attractive and applicable alternative in organic synthesis.


Assuntos
Compostos Organofosforados , Polímeros , Microesferas , Catálise
15.
Environ Pollut ; 296: 118739, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34953956

RESUMO

Bisphenol A (BPA) exposure has many adverse effects on the reproductive system in animals and humans. Ten-eleven translocation 1 (TET1) is closely related to a variety of biological processes through regulating the dynamic balance of DNA demethylation and methylation. However, the role and mechanism of TET1 during BPA induced reproductive toxicity are largely unknown. In this study, mouse spermatogonia cell line GC-2 was treated with BPA in the final concentration of 0, 20, 40 and 80 µM for 72 h. The cell model of differential TET1 gene expression was established to explore the role and mechanism. We found that the growth rate of GC-2 cells, and the intracellular calcium level decreased significantly with the increase of BPA dose, while TET1 and Catsper1-4 expression level decrease with a dose-dependent relationship. Furthermore, TET1 overexpression promoted the proliferation of GC-2 cell, the increase of calcium ion concentration, and the expression level of Catsper1-4, while knockdown of TET1 leads to the opposite results. Mechanistically, TET1 expression promoted the hydroxymethylation of Catsper1-4 and reduced their methylation level. In addition, the expression level of Catsper1-4 was positively correlated with TET1 gene expression level in semen samples of the population. Our study revealed for the first time that TET1 gene regulates the expression of related molecules in the Catsper calcium signal pathway through its hydroxymethylation modification to affect the calcium level, thereby participating in the process of BPA induced damage. These results indicated that TET1 gene may be a potential biomarker of BPA induced male reproductive toxicity.


Assuntos
Compostos Benzidrílicos , Proteínas Proto-Oncogênicas , Animais , Compostos Benzidrílicos/toxicidade , Canais de Cálcio/genética , Canais de Cálcio/metabolismo , Metilação de DNA , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Masculino , Camundongos , Fenóis/toxicidade , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Transdução de Sinais
16.
Front Neurorobot ; 15: 751642, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34899229

RESUMO

The lower limb exoskeleton is playing an increasing role in enabling individuals with spinal cord injury (SCI) to stand upright, walk, turn, and so on. Hence, it is essential to maintain the balance of the human-exoskeleton system during movements. However, the balance of the human-exoskeleton system is challenging to maintain. There are no effective balance control strategies because most of them can only be used in a specific movement like walking or standing. Hence, the primary aim of the current study is to propose a balance control strategy to improve the balance of the human-exoskeleton system in dynamic movements. This study proposes a new safety index named Enhanced Stability Pyramid Index (ESPI), and a new balance control strategy is based on the ESPI and the Dynamic Movement Primitives (DMPs). To incorporate dynamic information of the system, the ESPI employs eXtrapolated Center of Mass (XCoM) instead of the center of mass (CoM). Meanwhile, Time-to-Contact (TTC), the urgency of safety, is used as an automatic weight assignment factor of ESPI instead of the traditional manual one. Then, the balance control strategy utilizing DMPs to generate the gait trajectory according to the scalar and vector values of the ESPI is proposed. Finally, the walking simulation in Gazebo and the experiments of the human-exoskeleton system verify the effectiveness of the index and balance control strategy.

17.
Dalton Trans ; 50(28): 9871-9880, 2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34195721

RESUMO

Cyclometalated iridium(iii) complexes have been investigated as promising electron donor (D) materials in organic solar cells (OSCs) due to their unique octahedral configuration for optimized morphology and their significantly long lifetimes potentially for enhanced exciton dissociation. However, the application as electron acceptor (A) materials has never been reported. In order to fill this blank, herein, two cyclometalated heteroleptic Ir complexes, TRIr and 2TRIr, based on electron donating-accepting type organic ligands with different π-conjugation lengths are reported as electron acceptor materials in comparison with their corresponding main organic ligands. The two Ir complexes exhibit suitable HOMO/LUMO energy levels of -5.55/-3.47 eV and -5.44/-3.48 eV, which are ∼0.1 eV higher in the HOMO and ∼0.15 eV deeper in the LUMO than the TR and 2TR ligands, respectively. 2TRIr with extended ligand π-conjugation displays a poor triplet feature, while TRIr demonstrates obvious metal-to-ligand charge transfer (MLCT) transition absorption, with a triplet component photoluminescence (PL) lifetime of 85 ns in neat films. When blended with PBDB-T in bulk heterojunction (BHJ) OSCs, the power conversion efficiencies (PCEs) are 2-3 times higher than their relevant ligands, with values of 1.20% and 1.62% for TRIr and 2TRIr, and 0.58% and 0.47% for the TR and 2TR ligand-based devices, respectively. TRIr and 2TRIr based active layer blends exhibit poorer hole and electron mobilities, whereas compared with their relatively linear planar ligands, both of the two octahedral Ir complexes exhibit an optimized surface morphology for less bimolecular recombination and more efficient exciton dissociation, thus contributing to improved photovoltaic performance.

18.
J Hazard Mater ; 404(Pt B): 124119, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33075625

RESUMO

This work presents an overview about the suppressant enhanced explosion parameter (SEEP) phenomenon in aluminum dust explosion moderation. The SEEP phenomenon can be attributed to either the flammable gas produced by decomposition of insufficient chemical suppressant so as to form an explosible hybrid mixture, or to the improvement in dust dispersibility caused by small amounts of thermal inhibitor so as to form better dispersed dust clouds. Aluminum (Al) and four particle sizes of alumina (Al2O3) were used to confirm a physically caused SEEP phenomenon by performing flame propagation experiments. Higher flame spread velocities (FSVs) in Al dust clouds were found in the presence of 5 or 10% <150 and <45-µm Al2O3 powder. Adding micro-sized Al2O3 disrupted inter-particle contact in combustible dusts, decreased inter-particle forces, and formed dust clouds with better dispersibility, thereby decreasing the effective particle size distribution (PSD) of Al dust. A strong thermal effect brought about by 2.5 µm Al2O3 overcame the negative effect of improved dispersion, preventing SEEP from occurring. The addition of 50 nm Al2O3 increased cohesion of powder mixtures, and decreased dust dispersibility. With benefits from both dispersion suppression and the thermal effect, Al flame propagation was well quenched.

19.
ACS Appl Mater Interfaces ; 13(41): 49215-49223, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34628847

RESUMO

A novel chiral separation membrane was fabricated by assembling l-cysteine (l-Cys)-modified graphene oxide sheets. l-Cys modification leads to an enantiomer separation membrane with an accessible interlayer spacing of 8 Å, which allows high solvent permeability. In the racemate separation experiments under isobaric conditions, the enantiomeric excess (ee) values of alanine (Ala), threonine (Thr), tyrosine (Tyr), and penicillamine (Pen) racemates in the permeation solution were 43.60, 44.11, 27.43, and 46.44%, respectively. In the racemate separation experiments under negative pressure, the separation performances of Ala, Thr, and Tyr were still maintained, and the enantiomeric excess (ee) values of the filtrate after separation were 56.80, 54.57, and 32.34%, respectively. These results indicate that the as-prepared GO-Cys membrane has a great practical value in the field of enantiomer separation.

20.
Front Oncol ; 11: 798425, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35047409

RESUMO

Interferon-induced protein 44-like (IFI44L), a type I interferon-stimulated gene (ISG), has been reported to be involved in innate immune processes and to act as a tumor suppressor in several cancers. However, its immune implication on lung cancer remains unclear. Here, we systemically analyzed the immune association of IFI44L with multiple tumor-infiltrating immune cells (TIICs) and immunomodulators through bioinformatics methods in The Cancer Genome Atlas (TCGA) lung cancer cohorts. Then, the IFI44L-related immunomodulators were selected to construct the prognostic signatures in the lung adenocarcinoma (LUAD) cohort and the lung squamous cell carcinoma (LUSC) cohort, respectively. Concordance index and time-dependent receiver operating characteristics (ROC) curves were applied to evaluate the prognostic signatures. GSE72094 and GSE50081 were used to validate the TCGA-LUAD signature and TCGA-LUSC signature, respectively. A nomogram was established by risk score and clinical features in the LUAD cohort. Finally, the prognostic value and biological function of IFI44L were verified in a real-world cohort and in vitro experiments. The results indicated that IFI44L showed significant correlation with TIICs in LUAD and LUSC samples. Functional enrichment analysis showed that IFI44L may participate in various cancer/immune-related pathways, including JAK/STAT signaling pathway and NF-κB signaling pathway. A total of 44 immunomodulators presented obvious association with IFI44L in the TCGA-LUAD cohort and a robust 10-immunomodulator signature was constructed. Patients in the higher-risk group presented worse prognosis than those in the lower-risk group. Notably, the risk signature was successfully validated in GSE72094. Multivariate Cox regression suggested that the risk signature could act as independent prognostic factors in both TCGA-LUAD and GSE72094 cohorts. Besides, a 17-immunomodulator signature was established in the TCGA-LUSC cohort and similar results were presented through analysis. The nomogram exhibited good accuracy in predicting overall survival (OS) outcome among TCGA-LUAD patients than the risk signature and other clinical features, with the area under curve values being 0.782 at 1 year, 0.825 at 3 years, and 0.792 at 5 years. Finally, tissue microarray analysis indicated that higher expression of IFI44L presented opposite relationship with pathological stage (p = 0.016) and a better outcome among lung cancer patients (p = 0.024). Functional experiments found that IFI44L overexpression significantly inhibited the proliferation, migration, and invasion in LUAD and LUSC cells; RT-qPCR experiments verified the correlation between the expression level of IFI44L with multiple immunomodulators in SPC-A-1 and NCI-H520 cells. In conclusion, our research highlighted that IFI44L is associated with tumor immune infiltration and provided information on IFI44L's immune implication, which indicates that IFI44L has potential clinical immunotherapeutic value and the proposed nomogram is a promising biomarker for non-small cell lung cancer patients.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA