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1.
Adv Mater ; 32(7): e1905764, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31850652

RESUMO

Neuromorphic computing consisting of artificial synapses and neural network algorithms provides a promising approach for overcoming the inherent limitations of current computing architecture. Developments in electronic devices that can accurately mimic the synaptic plasticity of biological synapses, have promoted the research boom of neuromorphic computing. It is reported that robust ferroelectric tunnel junctions can be employed to design high-performance electronic synapses. These devices show an excellent memristor function with many reproducible states (≈200) through gradual ferroelectric domain switching. Both short- and long-term plasticity can be emulated by finely tuning the applied pulse parameters in the electronic synapse. The analog conductance switching exhibits high linearity and symmetry with small switching variations. A simulated artificial neural network with supervised learning built from these synaptic devices exhibited high classification accuracy (96.4%) for the Mixed National Institute of Standards and Technology (MNIST) handwritten recognition data set.

2.
ACS Appl Mater Interfaces ; 11(46): 43473-43479, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31702891

RESUMO

The development of artificial synapses has enabled the establishment of brain-inspired computing systems, which provides a promising approach for overcoming the inherent limitations of current computer systems. The two-terminal memristors that faithfully mimic the function of biological synapses have intensive prospects in the neural network field. Here, we propose a high-performance artificial synapse based on oxide tunnel junctions with oxygen vacancy migration. Both short-term and long-term plasticities are mimicked in one device. The oxygen vacancy migration through oxide ultrathin films is utilized to manipulate long-term plasticity. Essential synaptic functions, such as paired pulse facilitation, post-tetanic potentiation, as well as spike-timing-dependent plasticity, are successfully implemented in one device by finely modifying the shape of the pre- and postsynaptic spikes. Ultralow femtojoule energy consumption comparable to that of the human brain indicates its potential application in efficient neuromorphic computing. Oxide tunnel junctions proposed in this work provide an alternative approach for realizing energy-efficient brain-like chips.

3.
ACS Appl Polym Mater ; 1(4): 657-663, 2019 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-31650131

RESUMO

Here, we demonstrate the anionic polymerization and the high reactivity of the novel monomer diethyl methylene malonate (DEMM). At room temperature and under atmospheric conditions, water and anionic functional groups (i.e., carboxyl, boronic, and phenol) quickly initiate DEMM. The polymerization of DEMM in water and the final molecular weight of the polymer were both demonstrated to be pH-dependent. Systematically, investigations were conducted to study the conversion rate of DEMM with various functional groups, and the polymerization was verified to occur with anionic groups using a carboxylate-initiated DEMM system. For coating applications, we also investigated a multifunctional derivative monomer called (DEMM)6 that is an oligomeric polyester of DEMM esterified with butanediol that contains on average six repeat units of reactive DEMM (commercially known as Forza B3000 XP). The incorporation of 15 wt % (DEMM)6 into latex containing methacrylate acid as a functional monomer yielded cross-linked coatings with a gel content of 76.25 wt % that had a 289% improvement in rub-resistance performance compared to controls (without (DEMM)6). This study provides a facile methodology to synthesize cross-linked latex coatings at room temperature.

4.
iScience ; 16: 368-377, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31220760

RESUMO

Oxide-based resistive switching devices, including ferroelectric tunnel junctions and resistance random access memory, are promising candidates for the next-generation non-volatile memory technology. In this work, we propose a ferroionic tunnel junction to realize a giant electroresistance. It functions as a ferroelectric tunnel junction at low resistance state and as a Schottky junction at high resistance state, due to interface engineering through the field-induced migration of oxygen vacancies. An extremely large electroresistance with ON/OFF ratios of 5.1×107 at room temperature and 2.1×109 at 10 K is achieved, using an ultrathin BaTiO3-δ layer as the ferroelectric barrier and a semiconducting Nb-doped SrTiO3 substrate as the bottom electrode. The results point toward an appealing way for the design of high-performance resistive switching devices based on ultrathin oxide heterostructures by ionic controlled interface engineering.

5.
Adv Mater ; 31(19): e1900379, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30924206

RESUMO

Hardware implementation of artificial synaptic devices that emulate the functions of biological synapses is inspired by the biological neuromorphic system and has drawn considerable interest. Here, a three-terminal ferrite synaptic device based on a topotactic phase transition between crystalline phases is presented. The electrolyte-gating-controlled topotactic phase transformation between brownmillerite SrFeO2.5 and perovskite SrFeO3- δ is confirmed from the examination of the crystal and electronic structure. A synaptic transistor with electrolyte-gated ferrite films by harnessing gate-controllable multilevel conduction states, which originate from many distinct oxygen-deficient perovskite structures of SrFeOx induced by topotactic phase transformation, is successfully constructed. This three-terminal artificial synapse can mimic important synaptic functions, such as synaptic plasticity and spike-timing-dependent plasticity. Simulations of a neural network consisting of ferrite synaptic transistors indicate that the system offers high classification accuracy. These results provide insight into the potential application of advanced topotactic phase transformation materials for designing artificial synapses with high performance.

6.
Ind Eng Chem Res ; 58(2): 908-916, 2019 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-30679886

RESUMO

Epoxy-based powder coatings are an attractive alternative to solvent-borne coatings. Here, in-house synthesized low glass transition temperature (Tg) particles containing epoxy resin and polymethyl methacrylate formed coatings at room temperature upon impact with a surface. Suspension polymerization was used to prepare particles as a function of diglycidyl ether of bisphenol A (DGEBA) and methyl methacrylate ratios. Higher incorporation of DGEBA decreased the Tg to below ~20°C and eliminated the need to heat the particles and/or aluminum substrates to form coatings. Using an electrostatic powder coating apparatus, a ~70% particle deposition efficiency was achieved on aluminum substrates heated to 200°C. Whereas, at room temperature, high-speed single particle impact experiments proved that particle bonding occurred at a critical velocity of 438 m/s, comparable to commercial cold spray technologies. The in-house synthesized particles used in this study hold potential in traditional and emerging additive manufacturing applications.

7.
ACS Appl Mater Interfaces ; 10(50): 43792-43801, 2018 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-30474948

RESUMO

Exploring and manipulating domain configurations in ferroelectric thin films are of critical importance for the design and fabrication of ferroelectric heterostructures with a novel functional performance. In this study, BiFeO3 (BFO) ultrathin films with various Bi/Fe ratios from excess Bi to deficient Bi have been grown on (La0.7Sr0.3)MnO3 (LSMO)-covered SrTiO3 substrates by a laser molecular beam epitaxy system. Atomic force microscopy and piezoresponse force microscopy measurements show that both the surface morphology and ferroelectric polarization of the films are relevant to Bi nonstoichiometry. More significantly, a Bi-excess thin film shows an upward (from substrate to film surface) uniform ferroelectric polarization, whereas a Bi-deficient thin film exhibits a downward uniform polarization, which means the as-grown polarization of BFO thin films can be controlled by changing the Bi contents. Atomic-scale structural and chemical characterizations and second-harmonic generation measurements reveal that two different kinds of structural distortions and interface atomic configurations in the BFO/LSMO heterostructures can be induced by the change of Bi nonstoichiometry, leading to the two opposite as-grown ferroelectric polarizations. It has also been revealed that the band gap of BFO thin films can be modulated via Bi nonstoichiometry. These results demonstrate that Bi nonstoichiometry plays a key role on the ferroelectric domain states and physical properties of BFO thin films and also open a new avenue to manipulate the structure and ferroelectric domain states in BFO thin films.

8.
Adv Mater ; : e1801548, 2018 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-29974526

RESUMO

Considering that the human brain uses ≈1015 synapses to operate, the development of effective artificial synapses is essential to build brain-inspired computing systems. In biological synapses, the voltage-gated ion channels are very important for regulating the action-potential firing. Here, an electrolyte-gated transistor using WO3 with a unique tunnel structure, which can emulate the ionic modulation process of biological synapses, is proposed. The transistor successfully realizes synaptic functions of both short-term and long-term plasticity. Short-term plasticity is mimicked with the help of electrolyte ion dynamics under low electrical bias, whereas the long-term plasticity is realized using proton insertion in WO3 under high electrical bias. This is a new working approach to control the transition from short-term memory to long-term memory using different gate voltage amplitude for artificial synapses. Other essential synaptic behaviors, such as paired pulse facilitation, the depression and potentiation of synaptic weight, as well as spike-timing-dependent plasticity are also implemented in this artificial synapse. These results provide a new recipe for designing synaptic electrolyte-gated transistors through the electrostatic and electrochemical effects.

9.
ACS Appl Mater Interfaces ; 10(12): 10211-10219, 2018 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-29510620

RESUMO

Structure determines material's functionality, and strain tunes the structure. Tuning the coherent epitaxial strain by varying the thickness of the films is a precise route to manipulate the functional properties in the low-dimensional oxide materials. Here, to explore the effects of the coherent epitaxial strain on the properties of SrCoO2.5 thin films, thickness-dependent evolutions of the structural properties and electronic structures were investigated by X-ray diffraction, Raman spectra, optical absorption spectra, scanning transmission electron microscopy (STEM), and first-principles calculations. By increasing the thickness of the SrCoO2.5 films, the c-axis lattice constant decreases, indicating the relaxation of the coherent epitaxial strain. The energy band gap increases and the Raman spectra undergo a substantial softening with the relaxation of the coherent epitaxial strain. From the STEM results, it can be concluded that the strain causes the variation of the oxygen content in the BM-SCO2.5 films, which results in the variation of band gaps with varying the strain. First-principles calculations show that strain-induced changes in bond lengths and angles of the octahedral CoO6 and tetrahedral CoO4 cannot explain the variation band gap. Our findings offer an alternative strategy to manipulate structural and electronic properties by tuning the coherent epitaxial strain in transition-metal oxide thin films.

10.
Biochimie ; 146: 28-34, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29158005

RESUMO

The aim of this study was to evaluate the effects of 1,25(OH)2D3 on the apoptosis of human hepatocellular carcinoma (HCC) cells. The effects of 1,25(OH)2D3 on the proliferation and apoptosis of human HCC cells by regulating histone deacetylase 2 (HDAC2) were assessed by MTT assay and flow cytometry. The effects of 1,25(OH)2D3 on the expressions of related proteins in the apoptosis pathway by regulating HDAC2 as well as the mechanism were studied by Western blot and quantitative real-time PCR. A nude mouse model of HCC xenograft was established. A control group, a 1,25(OH)2D3 treatment group, a 1,25(OH)2D3 + HDAC2 overexpression group, an HDAC2 interference group and an HDAC2 overexpression group were set. The tumor volume was recorded, and histopathological changes were observed by HE staining. 1,25(OH)2D3 inhibited the proliferation of HepG2 cells and induced their apoptosis. Overexpression of HDAC2 attenuated the inhibitory effects of 1,25(OH)2D3 on the proliferation of HepG2 cells and its ability to induce apoptosis. In the 1,25(OH)2D3 + HDAC2 overexpression group, the expressions of p53, Bax, DR5 and caspase 8 were significantly lower but the expression of Bcl-2 was significantly higher than those of the 1,25(OH)2D3 treatment group (P < 0.05). Compared with the control group, 1,25(OH)2D3 treatment and HDAC2 interference groups had significantly decreased tumor volumes and promoted apoptosis of HCC cells in tumor tissues. Overexpression of HDAC2 weakened the inhibitory effects of 1,25(OH)2D3 on tumor volume and its ability to induce apoptosis in tissues. A large area of tumor cells underwent necrosis in 1,25(OH)2D3 treatment and HDAC2 interference groups. In the 1,25(OH)2D3 + HDAC2 overexpression group, both the area of necrosis and cell volume decreased. In conclusion, 1,25(OH)2D3 inhibited the proliferation of HCC cells and induced their apoptosis by down-regulating the expression of HDAC2, up-regulating p53, and regulating its downstream mitochondria-mediated pathway and the exogenous DR-mediated pathway.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Calcitriol/farmacologia , Carcinoma Hepatocelular/patologia , Histona Desacetilase 2/metabolismo , Neoplasias Hepáticas/patologia , Ensaios Antitumorais Modelo de Xenoenxerto , Animais , Caspase 8/genética , Caspase 8/metabolismo , Proliferação de Células/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , Camundongos , Camundongos Nus , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
11.
Toxicol Mech Methods ; 28(5): 345-352, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29254411

RESUMO

Melamine is a nitrogen-containing heterocyclic organic compound with a triazine skeleton, which has been widely applied in industrial and chemical fields. Previous toxicity studies of melamine mainly focused on renal toxicity and hepatic pathological changes, but its toxicity against the reproductive system has seldom been assessed. We investigated the effects of melamine on the reproductive system of male mice. Forty healthy male Kunming mice were randomly divided into a normal saline negative control group, a low-dose melamine group, a medium-dose melamine group and a high-dose melamine group (n = 10). The mice were administered for five consecutive days and killed on the 35th day after first administration. In melamine administration groups, seminiferous tubules had disordered, loose arrangement, and spermatogenic cells at all levels obviously decreased. The sperm count and motility decreased significantly, and the sperm deformity rate increased significantly. Melamine induced apoptosis of testicular spermatogenic cells. To further explore the mechanism, we detected metabolism-related enzymes sorbitol dehydrogenase (SDH) and lactate dehydrogenase (LDH) as well as oxidative stress indices superoxide dismutase (SOD) and malondialdehyde (MDA). The activities of SDH, LDH and SOD in melamine treatment groups decreased significantly, and the MDA level increased obviously. The expressions of apoptosis-related proteins Bcl-2, Bax and caspase-3 were detected by immunohistochemistry. The expression of Bcl-2 significantly increased, but those of Bax and caspase-3 significantly reduced (p < 0.05). In conclusion, melamine damaged the reproductive system of mice via the oxidative stress pathway and by inducing cell apoptosis.


Assuntos
Reprodução/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Testículo/efeitos dos fármacos , Triazinas/toxicidade , Animais , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Relação Dose-Resposta a Droga , Metabolismo Energético/efeitos dos fármacos , L-Iditol 2-Desidrogenase/metabolismo , L-Lactato Desidrogenase/metabolismo , Masculino , Malondialdeído/metabolismo , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Túbulos Seminíferos/efeitos dos fármacos , Túbulos Seminíferos/metabolismo , Túbulos Seminíferos/patologia , Contagem de Espermatozoides , Motilidade Espermática/efeitos dos fármacos , Espermatozoides/metabolismo , Espermatozoides/patologia , Superóxido Dismutase/metabolismo , Testículo/metabolismo , Testículo/patologia , Fatores de Tempo , Proteína X Associada a bcl-2/metabolismo
12.
Appl Opt ; 56(30): 8348-8352, 2017 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-29091611

RESUMO

Analogous with scanning electron microscopy, we use an oblique-incidence reflectivity difference (OIRD) approach for morphology detection. By scanning the active carbon clusters in a one-dimensional way and the reservoir rocks in a two-dimensional way, the morphology of the samples' surface can be revealed in OIRD signal images. High OIRD signals of active carbon samples refer to the centralized distribution areas of carbon, and the fluctuations are caused by the uneven distribution of carbon pellets. OIRD intensity is proportional to the thickness of materials. In terms of rocks, the trough areas with smaller values refer to the low-lying fields. The areas with relatively large OIRD intensities correspond to the protuberance areas of rocks. Consequently, OIRD is a sensitive yet rapid measure of surface detection in material and petrogeology science.

13.
Oncotarget ; 8(37): 61048-61056, 2017 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-28977845

RESUMO

Pregnancies complicated by pre-gestational diabetes (PGD) are associated with a higher rate of adverse outcomes, including an increased rage of preterm delivery, pregnancy-induced hypertension, pre-eclampsia, caesarean section, perinatal mortality, stillbirth, shoulder dystocia, macrosomia, small for gestational age, large for gestational age, low birth weight, neonatal hypoglycemia, neonatal death, low Apgar score, NICU admission, jaundice and respiratory distress. In the past two decades, numerous reports have been published regarding associations between PGD and risk of adverse outcomes. However, study results are inconsistent. To provide a synopsis of the current understanding of PGD for risk of adverse pregnancy outcomes, a random-effects meta-analysis over 40 million subjects from 100 studies was performed to calculate the pooled ORs. Potential sources of heterogeneity were systematically explored by multiple strata analyses and meta-regression. Overall, PGD were significantly associated with increased risk of preterm delivery (OR=3.48), LGA (OR=3.90), perinatal mortality (OR=3.39), stillbirth (OR=3.52), pre-eclampsia (OR=3.48), caesarean section (OR=3.52), NICU admission (OR=3.92), and neonatal hypoglycemia (OR=26.62). Significant results were also observed for 7 adverse outcomes with OR range from 1.54 to 2.82, while no association was found for SGA and respiratory distress after Bonferroni correction. We found that women with T1DM had higher risks for most of adverse pregnancy outcomes compared with women with T2DM. When stratified by study design, sample size, type of diabetes, geographic region, and study quality, significant associations remains. Our findings demonstrated that PGD is a strong risk-conferring factor for adverse maternal, perinatal and neonatal outcomes.

14.
Sci Rep ; 7(1): 9051, 2017 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-28831169

RESUMO

For ferroelectric materials, where the polar state breaks the inversion symmetry, second harmonic generation is a useful tool to prove their ferroelectric properties. However, the correlation between the anisotropy patterns and the polarization orientation of the ferroelectric domains has not been clarified yet. In this work, we systematically investigated this correlation in a typical perovskite oxide ferroelectric, Barium Titanate (BaTiO3) crystal, by second harmonic generation and the piezoresponse force microscopy technique. The evolution of polarization-dependent anisotropy patterns proves that there is a linear relationship between the rotation angle of second harmonic generation anisotropy patterns and the polarization angle of BaTiO3 single crystals. It is a direct evidence illustrating that the polarization of BaTiO3 crystal can be qualitatively identified in 0°-180° by second harmonic generation technology. This work gives a glance at improving a nonintrusive and convenient method to identify the polarization of perovskite ferroelectric materials.

15.
Sci Rep ; 7(1): 7693, 2017 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-28794426

RESUMO

Artificial superlattices constructed with ferromagnetic La0.7Sr0.3MnO3 layer and ferroelectric Ba0.7Sr0.3TiO3 layer were designed and fabricated on SrTiO3 substrates. An epitaxial growth with sharp interfaces between La0.7Sr0.3MnO3 and Ba0.7Sr0.3TiO3 layers was confirmed by scanning transmission electron microscopy and x-ray diffraction. An unambiguous charge transfer involving an electron transferring from the La0.7Sr0.3MnO3 layers to Ba0.7Sr0.3TiO3 layers (Mn3+→Mn4+; Ti4+→Ti3+) across the interface were resolved by electron energy loss spectra analysis. These observations are attributed to the possible modification in the stereochemistry of the Ti and Mn ions in the interfacial region. The out-of-plane lattice parameter, Curie temperature, and magnetoresistance are strongly affected by the thicknesses of the La0.7Sr0.3MnO3 and Ba0.7Sr0.3TiO3 layers. Huge magnetoresistance subsisting to low temperature was also observed in the La0.7Sr0.3MnO3/Ba0.7Sr0.3TiO3 superlattices. All spectral changes identified at a nanometer scale and their potential effect on the degradation of magnetic and transport properties at a macroscopic level. These findings highlight the importance of dependence on sublayer thickness, illustrating the high degree of tenability in these artificially low-dimensional oxide materials.

16.
Oncol Lett ; 14(1): 217-223, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28693156

RESUMO

The aim of the present study was to identify the appropriate DNA sequence and design high-quality primers for methylation-specific polymerase chain reaction (MSP). These primers may be used to examine and identify patients with early-stage epithelial ovarian carcinoma (EOC). Opioid binding protein/cell adhesion molecule like (OPCML), Runt-related transcription factor 3 and tissue factor pathway inhibitor 2 were selected as possible molecular markers. MSP primer sets were designed to monitor the methylation of the three markers. Free circulating DNA (fcDNA) from 194 patients with epithelial ovarian carcinoma and healthy donors were templates in the nested MSP. OPCML MSP was effective with respect to screening methylated fcDNA. One-way ANOVA P-values indicated that the difference in cancer antigen 125 (CA125), a biomarker for EOC diagnosis, level between early EOC and healthy donors was not significant. The methylation of OPCML was significantly altered in early-stage EOC compared with healthy donors (P<0.0001), and this supported the hypothesis that specific fcDNA methylation was able to distinguish patients with early-stage EOC from healthy donors. With respect to detecting early EOC, compared with the results of the CA125 test, MSP increased the κ coefficient from 0.140 to 0.757. Therefore, OPCML combined with fcDNA may be used to establish an improved clinical assay compared with the current CA125 test.

17.
Oncol Rep ; 38(3): 1845-1850, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28737824

RESUMO

The inhibitory effects of 1,25(OH)2D3 on the proliferation of a variety of cancer cell lines have been extensively reported. However, the underlying mechanisms remain largely unknown. In the present study, the effects of 1,25(OH)2D3 on the in vitro proliferation of human hepatocellular carcinoma HepG2 cells and the mechanism involved were investigated. Flow cytometry and MTT assay revealed that 1,25(OH)2D3 inhibited cell proliferation in vitro. Western blotting and real-time PCR indicated that 1,25(OH)2D3 upregulated the expression of phosphatase and tensin homologue deleted on chromosome 10 (PTEN) and attenuated that of histone deacetylase 2 (HDAC2). Knockdown of HDAC2 completely mimicked the effects of 1,25(OH)2D3 on PTEN gene expression. The influence of 1,25(OH)2D3 on PTEN expression was reversed in the cells treated with a recombinant pEGFP-LV2-HDAC2 plasmid. Akt phosphorylation, which was downregulated by 1,25(OH)2D3 treatment, was promoted by HDAC2 overexpression. These findings revealed that 1,25(OH)2D3 inhibited cell growth possibly by HDAC2-mediated PTEN upregulation, Akt deactivation, and inhibition of the PI3K/Akt signaling pathway.


Assuntos
Calcitriol/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Histona Desacetilase 2/metabolismo , Neoplasias Hepáticas/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , Neoplasias Hepáticas/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
18.
Sci Rep ; 7(1): 1359, 2017 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-28465509

RESUMO

Growing evidence has shown that gut microbiome is a key factor involved in liver health. Therefore, gut microbiota modulation with probiotic bacteria, such as Saccharomyces boulardii, constitutes a promising therapy for hepatosis. In this study, we aimed to investigate the protective effects of S. boulardii on D-Galactosamine-induced liver injury in mice. Liver function test and histopathological analysis both suggested that the liver injury can be effectively attenuated by S. boulardii administration. In the meantime, S. boulardii induced dramatic changes in the gut microbial composition. At the phylum level, we found that S. boulardii significantly increased in the relative abundance of Bacteroidetes, and decreased the relative abundance of Firmicutes and Proteobacteria, which may explain the hepatic protective effects of S. boulardii. Taken together, our results demonstrated that S. boulardii administration could change the gut microbiota in mice and alleviate acute liver failure, indicating a potential protective and therapeutic role of S. boulardii.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/microbiologia , Galactosamina/toxicidade , Microbioma Gastrointestinal , Saccharomyces boulardii , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Células 3T3 BALB , Doença Hepática Induzida por Substâncias e Drogas/dietoterapia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Galactosamina/análogos & derivados , Camundongos , Probióticos
19.
Cancer Biother Radiopharm ; 32(3): 101-110, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28414550

RESUMO

Cisplatin resistance is still one of the main reasons for failure of clinical therapy for cervical cancer. But the underlying molecular mechanisms involved in cisplatin resistance of cervical cancer have still remained unclear. Recent studies reported that long noncoding RNAs (lncRNAs) are novel nonprotein-coding transcripts, which might play a key role in cancer biogenesis and prognosis. One of the lncRNAs, urothelial cancer associated 1 (UCA1), has been shown to promote different types of cancer cell proliferation, migration, and invasion. This study showed that overexpression of UCA1 confers cisplatin resistance by promoting cancer cell proliferation and inhibiting apoptosis. In addition, knockdown of UCA1 remarkably decreased cisplatin resistance in cervical cancer cells. Moreover, results also indicated that UCA1 was involved in signaling pathways modulating cell apoptosis and proliferation. UCA1 suppressed apoptosis by downregulating caspase 3 and upregulating CDK2, whereas enhanced cell proliferation by increased level of survivin and decreased level of p21. This study reports for the first time that UCA1 might play an important role in the cisplatin resistance in cervical cancer, and also explain partially how UCA1 promotes cisplatin resistance in cancer cells. These results provide evidence to support that UCA1 can be used as a potential target for a novel therapeutic strategy for cervical cancer.


Assuntos
Cisplatino/farmacologia , RNA Longo não Codificante/biossíntese , Neoplasias do Colo do Útero/tratamento farmacológico , Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Feminino , Células HeLa , Humanos , Prognóstico , RNA Longo não Codificante/genética , Transdução de Sinais , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/metabolismo
20.
Sci Rep ; 6: 38268, 2016 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-27905565

RESUMO

BiFeO3 thin films have drawn much attention due to its potential applications for novel magnetoelectric devices and fundamental physics in magnetoelectric coupling. However, the structural evolution of BiFeO3 films with thickness remains controversial. Here we use an optical second-harmonic generation technique to explore the phase-related symmetry evolution of BiFeO3 thin films with the variation of thickness. The crystalline structures for 60 and 180-nm-thick BiFeO3 thin films were characterized by high-resolution X-ray diffractometry reciprocal space mapping and the local piezoelectric response for 60-nm-thick BiFeO3 thin films was characterized by piezoresponse force microscopy. The present results show that the symmetry of BiFeO3 thin films with a thickness below 60 nm belongs to the point group 4 mm. We conclude that the disappearance of fourfold rotational symmetry in SHG s-out pattern implies for the appearance of R-phase. The fact that the thinner the film is, the closer to 1 the tensor element ratio χ31/χ15 tends, indicates an increase of symmetry with the decrease of thickness for BiFeO3 thin films.

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