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1.
Sensors (Basel) ; 20(2)2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31936790

RESUMO

The basic phenomena of a cantilever energy harvesting device based on iron-gallium alloy magnetostrictive material for low frequency were systematically studied. The results highlighted how the physical parameters, geometric structure and bias conditions affected the vibration harvesting capacity through a thorough experimental aimed at enhancing the vibration energy harvesting capacity through an optimal design. How the performance is affected by the configuration of the multi-layers composite beam, material and dimensions of the elastic layer, arrangement position and number of bias magnets, the matching load resistance and other important design parameters was studied in depth. For the first time, it was clearly confirmed that the magnetic field of bias magnets and electromagnetic vibration shaker have almost no effect on the measurement of the voltage induced from the harvester. A harvesting power RMS up to 13.3 mW and power density RMS up to 3.7 mW/cm3/g was observed from the optimized prototype. Correspondingly, the DC output power and power density after the two-stage signal processing circuit were up to 5.2 mW and 1.45 mW/cm3/g, respectively. The prototype successfully powered multiple red light emitting diode lamps connected in a sinusoidal shape and multiple red digital display tubes, which verified the vibration harvesting capability or electricity-generating capability of the harvester prototype and the effectiveness of the signal converter.

2.
Sensors (Basel) ; 19(15)2019 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-31382645

RESUMO

Vibration energy harvesting attempts to generate electricity through recycling the discarded vibration energy that is usually lost or dissipated, and represents an alternative to traditional batteries and may even lead to reliable self-powered autonomous electronic devices. Energy harvesting based on magnetostrictive materials, which takes advantage of the coupling characteristics of the Villari effect and the Faraday electromagnetic induction effect, is a recent research field of great interest. Aiming to develop a new type of magnetostrictive energy harvester using Fe-Ga alloy, which is suitable for harvesting the vibration energy from base excitations and free excitations, a Fe-Ga based cantilever harvester was proposed. The energy harvesting performance of the harvester prototype, including its resonance characteristics, open-circuit output voltage-frequency response and amplitude characteristic under base excitation, influence of external resistance, energy harvesting performance under free excitation, the function of pre-magnetization and so on was studied systematically and carefully by experiments. In terms of the volume power density, the harvester prototype without pre-magnetized magnet when in series with the optimal resistor load displays a value of 2.653 mW/cm3. The average conversion efficiency without a pre-magnetic field is about 17.7% when it is in series with a 200 resistance. The energy harvesting and converting capability can therefore be improved greatly once the Fe-Ga beam is highly pre-magnetized. The prototype successfully lit up multi-LEDs and digital display tubes, which validates the sustainable power generation capacity of the fabricated prototype.

3.
Chem Commun (Camb) ; 54(93): 13107-13110, 2018 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-30398241

RESUMO

5-Formyluracil (5fU) based probes were designed and synthesized to detect Al3+ ions in vitro and in biological systems. These probes were synthesised using furan-2-carbohydrazide (fr) and 5fU derivatives. We also selectively labelled 5-formyluracil in DNA with the help of Al3+.


Assuntos
Alumínio/análise , Corantes Fluorescentes/química , Uracila/análogos & derivados , Cromatografia Líquida de Alta Pressão , Corantes Fluorescentes/síntese química , Células HeLa , Humanos , Imagem Óptica , Uracila/síntese química , Uracila/química
4.
Medicine (Baltimore) ; 95(36): e4613, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27603352

RESUMO

To evaluate the safety and efficacy of Ex-PRESS (R50) implantation combined with phacoemulsification in primary angle-closure glaucoma (PACG) patients with cataract.Twenty-four eyes of 24 patients with unregulated PACG underwent combined cataract and glaucoma surgery. After phacoemulsification and intraocular lens implantation, the Ex-PRESS (R-50) was inserted into the anterior chamber under a scleral flap. The intraocular pressure (IOP), best corrected visual acuity (BCVA), number of medications, and complications were recorded preoperatively as well as postoperatively on day 7 and at 1, 3, 6, and 12 months.The mean follow-up was 16.4 ±â€Š2.5 months (range 14-21 months) and the mean age of the patients was 64.7 ±â€Š6.8 years (range 56-78 years). The mean IOP was 20.4 ±â€Š5.4 mm Hg preoperatively and decreased to 10.2 ±â€Š2.8, 13.1 ±â€Š2.7, 14.9 ±â€Š4.1, 14.3 ±â€Š3.9, and 14.0 ±â€Š3.6 mm Hg on day 7 and at 1, 3, 6, and 12 months after surgery (all P < 0.005). At 12 months, the mean BCVA was 0.62 ±â€Š0.33 and the number of medications was 0.3 ±â€Š0.6. Most of complications were resolved spontaneously and conservatively.The Ex-PRESS implantation combined with phacoemulsification cataract extraction is safe and effective for reducing IOP and antiglaucoma medications in PACG patients with cataract.


Assuntos
Implantes para Drenagem de Glaucoma , Glaucoma de Ângulo Fechado/cirurgia , Facoemulsificação , Implantação de Prótese , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
5.
Exp Cell Res ; 343(2): 208-217, 2016 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-27060196

RESUMO

TNF-α is known to induce osteoblasts apoptosis, whereas mechanical stimulation has been shown to enhance osteoblast survival. In the present study, we found that mechanical stimulation in the form of fluid shear stress (FSS) suppresses TNF-α induced apoptosis in MC3T3-E1 cells. Extracellular signal-regulated kinase 5 (ERK5) is a member of the mitogen-activated protein kinase (MAPK) family that has been implicated in cell survival. We also demonstrated that FSS imposed by flow chamber in vitro leads to a markedly activation of ERK5, which was shown to be protective against TNF-α-induced apoptosis, whereas the transfection of siRNA against ERK5 (ERK5-siRNA) reversed the FSS-medicated anti-apoptotic effects. An initial FSS-mediated activation of ERK5 that phosphorylates AKT to increase its activity, and a following forkhead box O 3a (FoxO3a) was phosphorylated by activated AKT. Phosphorylated FoxO3a is sequestered in the cytoplasm, and prevents it from translocating to nucleus where it can increase the expression of FasL and Bim. The inhibition of AKT-FoxO3a signalings by a PI3K (PI3-kinase)/AKT inhibitor (LY294002) or the transfection of ERK5-siRNA led to the nuclear translocation of non-phosphorylated FoxO3a, and increased the protein expression of FasL and Bim. In addition, the activation of caspase-3 by TNF-α was significantly inhibited by aforementioned FSS-medicated mechanisms. In brief, the activation of ERK5-AKT-FoxO3a signaling pathways by FSS resulted in a decreased expression of FasL and Bim and an inhibition of caspase-3 activation, which exerts a protective effect that prevents osteoblasts from apoptosis.


Assuntos
Apoptose/efeitos dos fármacos , Proteína 11 Semelhante a Bcl-2/metabolismo , Proteína Ligante Fas/metabolismo , Proteína Forkhead Box O3/metabolismo , Proteína Quinase 7 Ativada por Mitógeno/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Reologia , Estresse Mecânico , Fator de Necrose Tumoral alfa/farmacologia , Animais , Apoptose/genética , Caspase 3/metabolismo , Linhagem Celular , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Regulação para Baixo/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Inativação Gênica/efeitos dos fármacos , Camundongos , Fosforilação/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , RNA Interferente Pequeno/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transfecção
6.
Connect Tissue Res ; 57(4): 299-306, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27115838

RESUMO

Fluid shear stress (FSS) is a ubiquitous mechanical stimulus that potently promotes osteoblast proliferation. Previously, we reported that extracellular signal-regulated kinase 5 (ERK5) is essential for FSS-induced osteoblast proliferation. However, the precise mechanism by which FSS promotes osteoblast proliferation via ERK5 activation is poorly understood. The aim of this study was to determine the critical role of Gαq in FSS-induced ERK5 phosphorylation and osteoblast proliferation, as well as the downstream targets of the Gαq-ERK5 pathway. MC3T3-E1 cells were transfected with 50 nM Gαq siRNA, treated with 5 mM XMD8-92 (a highly selective inhibitor of ERK5 activity), and/or exposed to FSS (12 dyn/cm(2)). Cell proliferation was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The protein expression levels of Gαq, P-ERK5, ERK5, Cyclin B1, and CDK1 were analyzed by Western blot. Physiological FSS exposure for 60 min remarkably promoted MC3T3-E1 cell proliferation, however, this effect was suppressed by siRNA-mediated Gαq knockdown or inhibition of ERK5 activity by XMD8-92 treatment, suggesting that Gαq and ERK5 might modulate FSS-increased osteoblast proliferation. Furthermore, ERK5 phosphorylation was dramatically inhibited by Gαq siRNA. In addition, our study further revealed that FSS treatment of MC3T3-E1 cells for 60 min markedly upregulated the protein expression levels of Cyclin B1 and CDK1, and this increased expression was predominantly blocked by Gαq siRNA or XMD8-92 treatment. We propose that FSS acts on the Gαq-ERK5 signaling pathway to upregulate Cyclin B1 and CDK1 expression, thereby resulting in MC3T3-E1 cell proliferation. Thus, the Gαq-ERK5 signaling pathway may provide useful information regarding the treatment of bone metabolic disease.


Assuntos
Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Proteína Quinase 7 Ativada por Mitógeno/metabolismo , Osteoblastos/citologia , Osteoblastos/metabolismo , Reologia , Resistência ao Cisalhamento , Transdução de Sinais , Estresse Mecânico , Animais , Benzodiazepinonas/farmacologia , Proteína Quinase CDC2 , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Ciclina B1/metabolismo , Quinases Ciclina-Dependentes/metabolismo , Camundongos , Proteína Quinase 7 Ativada por Mitógeno/antagonistas & inibidores , Modelos Biológicos , Osteoblastos/efeitos dos fármacos , Osteoblastos/enzimologia , Fosforilação/efeitos dos fármacos , RNA Interferente Pequeno/metabolismo , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
7.
Biochem Biophys Res Commun ; 466(1): 117-23, 2015 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-26325467

RESUMO

Fluid shear stress (FSS) is a potent mechanical stimulus and prevents cells from TNF-a-induced apoptosis. Recently, Extracellular-signal-regulated kinase 5 (ERK5) has been found to be involved in regulation of cell survival. However, little is known about the role of ERK5 signaling pathway in FSS-mediated anti-apoptotic effects in osteoblast. In this study, we show that FSS blocks TNF-a-induced apoptosis of MC3T3-E1 cells via ERK5 signaling pathway. We found that physiological FSS for 1 h significantly decreased TNF-α-induced MC3T3-E1 cells apoptosis. After inhibition of ERK5 activity by XMD8-92, a highly-selective inhibitor of ERK5 activity, the ability of FSS to inhibit TNF-α induced apoptosis was significantly decreased. Analysis of anti-apoptotic mechanisms indicated that exposure of MC3T3-E1 cells to FSS for 1 h increased phosphorylation of Bad and inhibited caspase-3 activity. After treatment with XMD8-92, phosphorylation of Bad by FSS was significantly blocked, but caspase-3 activity was increased. In summary, these findings indicated that FSS inhibits TNF-α-mediated signaling events in osteoblast by a mechanism dependent on activation of ERK5, and Bad is a crucial downstream target for ERK5. Those results implied that ERK5 signaling pathway play a crucial role in FSS-mediated anti-apoptotic effect in osteoblast. Thus, ERK5 signaling pathway may be a new drug treatment target of osteoporosis and related bone-wasting diseases.


Assuntos
Apoptose , Proteína Quinase 7 Ativada por Mitógeno/metabolismo , Osteoblastos/citologia , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo , Animais , Linhagem Celular , Camundongos , Osteoblastos/metabolismo , Fosforilação , Estresse Mecânico
8.
Med Sci Monit ; 20: 2106-8, 2014 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-25358601

RESUMO

Tumor local immune escape is one of the "hallmarks" of cancer leading to poor prognosis. The effects of local radiotherapy on tumors are rapidly emerging as opportunities to remodel and enhance immunity against cancer. However, this immunity remodeling and enhancing are not permanent after local radiotherapy. High expression of HIF-1α following local radiotherapy for tumor cell reoxygenation has been confirmed, and recently accumulating evidence shows the tumor immune suppression effects. These research findings suggest a new direction in the investigation of methods to enhance the efficacy of local radiotherapy. We speculate that by blocking HIF-1α, the immune effects of radiotherapy might be prolonged and enhanced.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/antagonistas & inibidores , Radioterapia , Evasão Tumoral , Humanos
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