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1.
Mater Sci Eng C Mater Biol Appl ; 128: 112326, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474877

RESUMO

Bone defects remain a challenging problem for doctors and patients in clinical practice. Processed pyritum is a traditional Chinese medicine that is often used to clinically treat bone fractures. It contains mainly Fe, Zn, Cu, Mn, and other elements. In this study, we added the extract of processed pyritum to ß-tricalcium phosphate and produced a porous composite TPP (TCP/processed pyritum) scaffold using digital light processing (DLP) 3D printing technology. Scanning electron microscopy (SEM) analysis revealed that TPP scaffolds contained interconnected pore structures. When compared with TCP scaffolds (1.35 ± 0.15 MPa), TPP scaffolds (5.50 ± 0.24 MPa) have stronger mechanical strength and can effectively induce osteoblast proliferation, differentiation, and mineralization in vitro. Meanwhile, the in vivo study showed that the TPP scaffold had better osteogenic capacity than the TCP scaffold. Furthermore, the TPP scaffold had good biosafety after implantation. In summary, the TPP scaffold is a promising biomaterial for the clinical treatment of bone defects.


Assuntos
Fosfatos de Cálcio , Tecidos Suporte , Humanos , Porosidade , Impressão Tridimensional
2.
Oncol Lett ; 21(2): 146, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33552265

RESUMO

Substantial evidence suggests that cancer stem cells (CSCs) are the main cause of the initiation, progression and recurrence of tumors. Benzidine has been identified as a risk factor for bladder cancer. The aim of the present study was to investigate the effects of benzidine on bladder CSCs (BCSCs) and the possible mechanism underlying its action. The bladder cancer cell lines UM-UC-3 and EJ were maintained in serum-free medium and cells forming three-dimensional spheres were characterized as BCSCs. The sphere-forming cells were exposed to different concentrations of benzidine and vismodegib, and western blotting was performed to evaluate the expression of markers associated with CSCs and the Sonic hedgehog (SHH) signaling pathway. Flow cytometry was used to detect the distribution of cells in different phases of the cell cycle, and immunofluorescence staining was used to detect the protein expression of CD44. The results revealed that the levels of BCSC markers, namely CD133, CD44, aldehyde dehydrogenase 1-A1, Nanog and octamer-binding transcription factor-4, in the cell spheres were markedly elevated compared with those in cells cultured in serum-supplemented medium. Furthermore, benzidine increased the expression of BCSC markers and promoted the sphere-forming ability of the cells. In addition, it was observed that benzidine activated the SHH pathway, while inhibition of the Shh pathway using vismodegib diminished the promoting effects of benzidine on BCSCs. The findings of the present study indicate that benzidine promoted the stemness of BCSCs via activation of the SHH pathway, which may support further exploration of the molecular basis of the association between benzidine exposure and bladder oncogenesis.

3.
Nutr Cancer ; 73(7): 1157-1167, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32586140

RESUMO

AIMS: Renal cell cancers typically exhibit high metastasis and recurrence, and this is thought to be due to renal cancer stem cells (CSCs). Meanwhile, aberrant activation of Sonic hedgehog (Shh) signaling is linked with CSCs. Resveratrol has direct or indirect impacts on the pathological activities of CSCs. However, the effects of resveratrol on renal CSCs remain to be elucidated. METHODS: We cultured renal CSCs in serum-free medium. Western blotting was used to analyze the expression levels of related proteins. The mRNA changes were detected by qRT-PCR after resveratrol treatment. The CD133+ cells were quantified by flow cytometry analysis. Immunofluorescence staining images showed the changes in CD44 and Smoothened expression in the cell spheres. RESULTS: Renal CSCs were enriched by tumorsphere formation assays of ACHN and 786-O cells. Resveratrol treatments markedly decreased the size and number of cell spheres and downregulated the expression of the Shh pathway-related proteins and CSCs markers. Moreover, we observed that resveratrol inhibited cell proliferation and induced cell apoptosis, while purmorphamine upregulated the Shh pathway and weakened the effects of resveratrol on renal CSCs. CONCLUSIONS: These results suggested that resveratrol is a potential novel therapeutic agent that targets inactivation of renal CSCs by affecting the function of the Shh pathway.

4.
Onco Targets Ther ; 13: 9689-9700, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33061449

RESUMO

Background: So far, little research has been conducted regarding the underlying mechanism of renal carcinogenesis at molecular level. Epithelial-mesenchymal transition (EMT) exerts an important part during tumor genesis as well as the development through mitogen-activated protein kinase (MAPK) pathways. Therefore, we hypothesized that EMT could promote renal cell carcinoma (RCC) progression via the ERK5/AP-1pathway. Materials and Methods: The RCC cell lines were utilized to be the models with in vitro exposure to cigarette smoke extract (CSE). We used the curcumin for the EMT intervention study. In the present study, immunohistochemistry (IHC), Western blotting, and real-time quantitative reverse transcription PCR had been used to determine the experimental results. EMT phenotypic alterations were assessed by changes in cell morphology, invasion and transfer ability, as well as expression of epithelial and mesenchymal markers. Results: In human renal cell carcinoma tissue, E-cadherin expression within the smoking renal cancer patients was down-regulated compared with that among the non-smokers. However, Vimentin, N-cadherin, and TWIST levels increased (P<0.05). Significantly, we clarified that ERK5/AP-1 exerted positive regulation on the renal cell carcinoma EMT mediated by CS, which was suggested based on the results of CS activating the ERK5/AP-1 pathway, as well as ERK5 inhibition via XMD8-92 reversed AP-1 protein levels and the EMT process. Furthermore, curcumin showed the same inhibitory effect as XMD8-92 and significantly reversed CS-induced EMT through inhibiting the ERK5/AP-1 signaling pathway. Conclusion: The above results indicated that ERK5/AP-1 signaling pathway exerts a vital part for CS-associated RCC development and cancer intervention.

5.
Langmuir ; 36(35): 10528-10536, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32791839

RESUMO

Protein purification is of vital importance in the food industry, drug discovery, and other related fields. Among many separation methods, polyelectrolyte (PE)-based phase separation was developed and recognized as a low-cost purification technique. In this work, spherical polyelectrolyte brushes (SPBs) with a high specific surface area were utilized to study the protein accessibility and selective protein binding on highly charged nanoparticles (NPs) as well as the selective phase separation of proteins. The correlation between charge anisotropy, protein binding, and phase separation was investigated on various protein systems including those proteins with similar isoelectric points (pI) such as bovine serum albumin (BSA) and ß-lactoglobulin (BLG), proteins with similar molecular weights such as BSA and hemoglobin (HB), and even protein variants (BLG-A and -B) with a tiny difference of amino acids. The nonspecific electrostatic interaction studied by turbidimetric titrations and isothermal calorimetry titration (ITC) indicates a specific binding between proteins and SPBs arising from the charge anisotropy of proteins. An optimized output based on selective protein binding on SPBs could be correlated for efficient protein separation through tuning external conditions including pH and ionic strength. These findings, therefore, proved that phase separation based on selective protein adsorption by SPBs was an efficient alternative for protein separation compared with the traditional practice.


Assuntos
Soroalbumina Bovina , Adsorção , Anisotropia , Concentração Osmolar , Polieletrólitos , Termodinâmica
7.
Fuel (Lond) ; 278: 118263, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32536702

RESUMO

Dimethoxymethane (DMM)-diesel blended fuels can simultaneously reduce exhaust emissions of soot and nitrogen oxide (NOX); several studies have been conducted in this regard. However, the influence of additive DMM on the production of inception and precursors of particulates, especially the relation between oxidation, morphology, and the nanostructure of soot particles has not been extensively investigated. In this study, a transmission electron microscope (TEM) and a thermogravimetric analyzer are introduced to acquire TEM images and conduct temperature-programmed-oxidation experiments. Aiming to study the influence of DMM addition on soot oxidation, morphology, and nanostructure, tests are conducted at different rotational speeds (1400 rpm and 2200 rpm), two engine loads (0.6 MPa and 1.2 MPa), and three fuels (D100, DMM6.4, and DMM13). The results show that the diameter distributions of all samples display a similar distribution, with the range of sample diameters being from 10 to 45 nm, and the addition of DMM reduces the dp (primary particle diameters) and the Df (fractal dimension), indicating a decreased structural compactness of aggregates, compared with diesel. Moreover, with increasing load and speed, La (the length of the fringe) increases and d (the distance between adjacent layer planes) decreases. Furthermore, with the addition of DMM, a more regular and higher degree of graphitization within soot particles can be observed in comparison to D100. The nanostructure influences the oxidation reaction of graphene segments with a line relation, leading to a difference in soot oxidation property.

8.
Adv Mater ; 32(17): e2000399, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32173931

RESUMO

Ceramic/polymer hybrid solid electrolytes (HSEs) have attracted worldwide attentions because they can overcome defects by combining the advantages of ceramic electrolytes (CEs) and solid polymer electrolytes (SPEs). However, the interface compatibility of CEs and SPEs in HSE limits their full function to a great extent. Herein, a flexible ceramic/polymer HSE is prepared via in situ coupling reaction. Ceramic and polymer are closely combined by strong chemical bonds, thus the problem of interface compatibility is resolved and the ions can transport rapidly by an expressway. The as-prepared membrane demonstrates an ionic conductivity of 9.83 × 10-4 S cm-1 at room temperature and a high Li+ transference numbers of 0.68. This in situ coupling reaction method provides an effective way to resolve the problem of interface compatibility.

9.
Cancer Manag Res ; 12: 177-187, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32021434

RESUMO

Background: Cervical cancer (CC) is the 4th most common malignancy and cancer-related fatality in women worldwide. Circular RNA is a newly recognized noncoding RNA form. More reports have confirmed their important regulatory functions in diverse physiological and cancer processes. However, the function and mechanisms of circ-HIPK3 in CC remain unknown. Methods: circ-HIPK3 expression status was verified between 45 paired CC and normal adjacent tissues from 45 CC patients, also the 6 CC cell lines and a normal human cervical epithelial End1/E6E7 cell line by qRT-PCR. Effects of circ-HIPK3 silence on CC cell phenotypes were estimated. Circular RNA interactome was applied to forecast binding site between circ-HIPK3 and miRNAs. Pearson correlation analysis was used to confirm the relationship between genes. Point mutation, RNA pull-down, luciferase assay and rescue experiments were applied for molecular mechanism exploration. Results: circ-HIPK3 expression was significantly elevated in CC cells and tissues. circ-HIPK3 silence repressed growth and metastasis, while induced apoptosis in CC cells. circ-HIPK3 sponged miRNA-338-3p (miR-338-3p); miR-338-3p to up-regulate hypoxia-inducible factor-1α (HIF-1α) and CC progress. MiR-338-3p silence or HIF-1α over-expression rescued circ-HIPK3 knockdown caused inhibition of CC malignant characteristics. Conclusion: circ-HIPK3 acts as a competing endogenous RNA of miR-338-3p to promote cell growth and metastasis in CC, via regulating HIF-1α mediated EMT. Therefore, targeting circ-HIPK3/miR-338-3p/HIF-1α axis may be a novel therapeutic strategy for CC.

10.
Urol Int ; 102(4): 399-405, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30712036

RESUMO

OBJECTIVE: To evaluate the efficacy and safety of early unclamping laparoscopic partial nephrectomy (LPN) for complex renal tumor relative to the standard artery clamping technique (SCT). METHODS: Sixty-one patients with complex renal tumor (RENAL score ≥7) underwent LPN at our institution from January 2013 to April 2017. LPN was performed via SCT in 32 patients and via the early unclamping technique (EUT) in 29 patients. Operation time, warm ischemia time (WIT), blood loss, bleeding requiring transfusion, tumor volume, excisional volume loss (EVL), complications, and renal function before and after operation of the affected kidney were compared between the groups. RESULTS: All surgeries were successful without conversion to open or nephrectomy. EUT reduced the WIT (p < 0.001) but did not increase the complication rate (p = 0.322). Although the tumor volume and EVL were larger in the EUT than in the SCT group (p = 0.011, p = 0.001), glomerular filtration rate (GFR) reduction in the affected kidney did not significantly differ between the groups (p = 0.120). CONCLUSION: Early unclamping LPN for complex renal tumor is safe and efficient. Additionally, the EUT could expand the application of LPN in complex renal tumors, and make this challenging surgery easier and safer.


Assuntos
Neoplasias Renais/cirurgia , Laparoscopia/métodos , Nefrectomia/métodos , Isquemia Quente , Adulto , Idoso , Perda Sanguínea Cirúrgica , China , Feminino , Seguimentos , Taxa de Filtração Glomerular , Humanos , Rim/patologia , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Segurança do Paciente , Estudos Retrospectivos , Robótica , Resultado do Tratamento
11.
J Appl Toxicol ; 38(9): 1251-1261, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29781141

RESUMO

Oxidative stress and inflammation are critically implicated in ambient fine particulate matter (mean diameter < 2.5 µm; PM2.5 )-induced lung injury. Autophagy, playing a crucial role in various physiopathological conditions, modulates cellular homeostasis and stress adaptation. Resveratrol is a phytoalexin that exerts potent antioxidant effects on cardiopulmonary diseases. To date, the mechanisms by which resveratrol protects against PM2.5 remain to be elucidated. In the present study, we investigated the effect of resveratrol on PM2.5 -induced oxidative injury. The potential role of nuclear factor erythroid-2-related factor 2 and autophagy in this progress was explored. Human bronchial epithelial cells were treated with PM2.5 and the cytotoxicity and oxidative stress markers were determined. The results showed that PM2.5 decreased cell viability and elevated the level of lactate dehydrogenase. The levels of malondialdehyde and reactive oxygen species were increased by PM2.5 exposure. PM2.5 also induced a significant increase of the inflammatory cytokines including interleukin (IL)-6, IL-8, IL-1ß and tumor necrosis factor α. Meanwhile, PM2.5 triggered autophagy formation and alteration of the nuclear factor erythroid-2-related factor 2 pathway. Furthermore, human bronchial epithelial cells were co-treated with PM2.5 and resveratrol in the presence or absence of 3-methylamphetamine, an inhibitor of autophagic formation. It was revealed that resveratrol intervention abolished PM2.5 -induced oxidative injury partially through the suppression of autophagy deregulation. Findings from this study could provide new insights into the molecular mechanisms of pulmonary intervention during PM2.5 exposure.


Assuntos
Antioxidantes/farmacologia , Autofagia/efeitos dos fármacos , Brônquios/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Material Particulado/toxicidade , Resveratrol/farmacologia , Brônquios/metabolismo , Brônquios/patologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Citocinas/metabolismo , Citoproteção , Relação Dose-Resposta a Droga , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Humanos , Mediadores da Inflamação/metabolismo , L-Lactato Desidrogenase/metabolismo , Malondialdeído/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Tamanho da Partícula , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
12.
ACS Appl Mater Interfaces ; 10(22): 18726-18733, 2018 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-29762008

RESUMO

A N,O-codoped hierarchical porous nanocomposite consisting of binary reduced graphene oxide and pyrolytic carbon (rGO/PC) from chitosan is fabricated. The optimized rGO/PC possesses micropores with size distribution concentrated around 1.1 nm and plenty of meso/macropores. The Brunauer-Emmett-Teller specific surface area is 480.8 m2 g-1, and it possesses impressively large pore volume of 2.14 cm3 g-1. On the basis of the synergistic effects of the following main factors: (i) the confined space effect in the hierarchical porous binary carbonaceous matrix; (ii) the anchor effects by strong chemical bonds with codoped N and O atoms; and (iii) the good flexibility and conductivity of rGO, the rGO/PC/S holding 75 wt % S exhibits high performance as Li-S battery cathode. Specific capacity of 1625 mA h g-1 can be delivered at 0.1 C (1 C = 1675 mA g-1), whereas 848 mA h g-1 can be maintained after 300 cycles at 1 C. Even at high rate of 5 C, 412 mA h g-1 can be restrained after 1000 cycles.

13.
Oncogenesis ; 7(3): 24, 2018 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-29540668

RESUMO

Cancer stem cells (CSCs) are essentially responsible for tumor initiation, growth, progression, metastasis and recurrence, and cigarette smoke (CS) is closely involved in the occurrence and development of kidney cancer. However, the effect of CS on renal CSCs has not been elucidated yet. In the present study, tumorsphere formation assay was used to enrich renal CSCs from 786-O and ACHN cells. We illustrated that CS effectively promoted renal CSCs stemness by enhancing tumorsphere formation, increasing the expression of renal CSCs markers (CD133, CD44, ALDHA1, Oct4, and Nanog) and elevating CD133+ cell population. Moreover, our results showed that CS triggered the activation of Sonic Hedgehog (SHH) pathway, while inhibition of SHH pathway dampened the promotive effects of CS on renal CSCs. Finally, higher levels of renal CSCs markers and SHH pathway-related proteins were observed in kidney cancer tissues from smokers than non-smoking cancer tissues. Taken together, these results demonstrated the important role of SHH pathway in regulating CS-induced renal CSCs stemness augment. Findings from this study could provide new insight into the molecular mechanisms of CS-elicited stemness of renal CSCs.

14.
Sci Rep ; 8(1): 2863, 2018 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-29434228

RESUMO

Hierarchical nanoporous N-doped carbon ZNC-1000 was prepared by facile pyrolysis of well-designed nanosized ZIF-8 precursor with optimized reaction temperature and time. It possesses large surface areas leading to sufficient exposed electrochemical active sites. Meanwhile, its moderate graphitization degree and suitable nanosized hierarchical porosity distributions would lead to the sufficient interaction between O2 and the electrocatalyst surface which would benefit the transports of electrons and the electrolyte ions for ORR. As an electrocatalyst for oxygen reduction reaction, the ZNC-1000 presents a better catalytic property than the commercial Pt/C with 6/1 mV positive shifts for onset/half-wave potentials and 1.567 mA cm-2 larger for limiting current density respectively. The stability of ZNC-1000 is also much better than that of Pt/C with negative shifts of 0/-2 mV (vs 5/31 mV) for onset/half-wave potentials and 6.0% vs 29.2% loss of limiting current density after 5000 cycles of accelerated durability test, as well as the relative current of 87.5% vs 40.2% retention after 30,000 s continuous chronoamperometric operation.

15.
Biol Res ; 50(1): 26, 2017 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-28870240

RESUMO

BACKGROUND: CCL2 was up-regulated in neurons and involved in microglia activation and neurological decline in mice suffering from hepatic encephalopathy (HE). However, no data exist concerning the effect of neuron-derived CCL2 on microglia activation in vitro. METHODS: The rats were pretreated with CCL2 receptor inhibitors (INCB or C021, 1 mg/kg/day i.p.) for 3 days prior to thioacetamide (TAA) administration (300 mg/kg/day i.p.) for inducing HE model. At 8 h following the last injection (and every 4 h after), the grade of encephalopathy was assessed. Blood and whole brains were collected at coma for measuring CCL2 and Iba1 expression. In vitro, primary neurons were stimulated with TNF-α, and then the medium were collected for addition to microglia cultures with or without INCB or C021 pretreatment. The effect of the medium on microglia proliferation and activation was evaluated after 24 h. RESULTS: CCL2 expression and microglia activation were elevated in the cerebral cortex of rats received TAA alone. CCL2 receptors inhibition improved neurological score and reduced cortical microglia activation. In vitro, TNF-α treatment induced CCL2 release by neurons. Medium from TNF-α stimulated neurons caused microglia proliferation and M1 markers expression, including iNOS, COX2, IL-6 and IL-1ß, which could be suppressed by INCB or C021 pretreatment. The medium could also facilitate p65 nuclear translocation and IκBα phosphorylation, and NF-κB inhibition reduced the increased IL-6 and IL-1ß expression induced by the medium. CONCLUSION: Neuron-derived CCL2 contributed to microglia activation and neurological decline in HE. Blocking CCL2 or inhibiting microglia excessive activation may be potential strategies for HE.


Assuntos
Quimiocina CCL2/metabolismo , Encefalopatia Hepática/metabolismo , Microglia/metabolismo , Neurônios/metabolismo , Receptores de Quimiocinas/antagonistas & inibidores , Animais , Quimiocina CCL2/antagonistas & inibidores , Meios de Cultura/farmacologia , Modelos Animais de Doenças , Expressão Gênica , Encefalopatia Hepática/induzido quimicamente , Encefalopatia Hepática/terapia , Interleucina-6/metabolismo , Microglia/efeitos dos fármacos , Doenças do Sistema Nervoso , Ratos , Tioacetamida
16.
Biochem Biophys Res Commun ; 493(1): 521-527, 2017 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-28870814

RESUMO

Cancer stem cells (CSCs) is responsible for the recurrence of human cancers. Thus, targeting CSCs is considered to be a valid way for human cancer treatment. Curcumin is a major component of phytochemicals that exerts potent anticancer activities. However, the effect of curcumin on bladder cancer stem cells (BCSCs) remains to be elucidated. In this study, we investigated the mechanism of curcumin suppressing bladder cancer stem cells. In this study, UM-UC-3 and EJ cells were cultured in serum-free medium (SFM) to form cell spheres that was characterized as BCSCs. Then cell spheres were separately treated with different concentrations of curcumin and purmorphamine. Cell cycle analysis were used to determine the percentage of cells in different phases. Western blot and quantitative real-time PCR analysis were used to detect the expression of relative molecules. Immunofluorescence staining analysis were also utilized to measure the protein level of CD44. We found that CSC markers, including CD44, CD133, ALDH1-A1, OCT-4 and Nanog, were obviously highly expressed in cell spheres. Moreover, we observed that curcumin reduced the cell spheres formation, decreased the expression of CSC markers, suppressed cell proliferation and induced cell apoptosis. We also found that curcumin inhibited the activation of Shh pathway, while the inhibitory effects of curcumin on BCSCs could be weakened by upregulation of Sonic Hedgehog (Shh) pathway. Altogether, these data suggested that curcumin inhibited the activities of BCSCs through suppressing Shh pathway, which might be an effective chemopreventive agent for bladder cancer intervention.


Assuntos
Curcumina/administração & dosagem , Proteínas Hedgehog/metabolismo , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/metabolismo , Antineoplásicos/administração & dosagem , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Humanos , Células-Tronco Neoplásicas/patologia , Transdução de Sinais/efeitos dos fármacos , Resultado do Tratamento , Neoplasias da Bexiga Urinária/patologia
17.
ACS Appl Mater Interfaces ; 9(34): 28366-28376, 2017 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-28766930

RESUMO

Unusual three-dimensional mesoporous carbon/reduced graphene oxide (MP-C/rGO) matrix possessing graphene nanolayer pore walls built up by three to five graphene monosheets and some carbon particles with the sizes of about 5 nm located between the graphene nanolayers was prepared by facile freeze-drying and then carbonization of the poly(vinyl alcohol) and graphene oxide mixture. The mesoporous carbonaceous MP-C/rGO sample has a high specific surface area of 661.6 m2 g-1, large specific pore volume of 1.54 m3 g-1, and focused pore size distribution of 2-10 nm. About 64 wt % sulfur could be held in the pores of the MP-C/rGO matrix. As the cathode of a Li-S battery, the MP-C/rGO/S composite showed excellent electrochemical property including a high initial specific capacity of 919 mA h g-1 at 1 C with the capacity retention ratio of 63.3% and the Coulombic efficiency above 90% after 500 cycles. Meanwhile, the initial specific capacity of 602 mA h g-1 at 5 C and remaining capacity of 391 mA h g-1 after 500 cycles with an outstanding Coulombic efficiency of 97% indicate its exceptionally stable rate performance.

18.
Sci Rep ; 7: 43352, 2017 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-28233857

RESUMO

A novel kind of Pt/N-rGO hybrid possessing of low content 5.31 wt.% Pt anchored on the surface of nitrogen doped reduced graphene oxide (N-rGO) evenly was prepared. The Pt has uniformed 2.8 nm diameter and exposed (111) crystal planes; meanwhile, the N works as the bridge between Pt and rGO with the Pt-N and N-C chemical bonds in Pt/N-rGO. The Pt/N-rGO material has a very high electrocatalytic activity in oxygen reduction reaction with the mass catalytic activity more than 1.5 times of the commercial Pt/C due to the synergistic catalytic effect of both N-doped carbon matrix and Pt nanoparticles. Moreover, the Pt/N-rGO exhibits an excellent stability with hardly loss (only 0.4%) after accelerated durability tests of 5000 cycles based on the stable Pt-N-C chemical bonds in Pt/N-rGO, which can prevent the detachment, dissolution, migration and aggregation of Pt nanoparticles on the matrix during the long-term cycling.

19.
Biol. Res ; 50: 26, 2017. graf
Artigo em Inglês | LILACS | ID: biblio-950876

RESUMO

BACKGROUND: CCL2 was up-regulated in neurons and involved in microglia activation and neurological decline in mice suffering from hepatic encephalopathy (HE). However, no data exist concerning the effect of neuron-derived CCL2 on microglia activation in vitro. METHODS: The rats were pretreated with CCL2 receptor inhibitors (INCB or C021, 1 mg/kg/day i.p.) for 3 days prior to thioacetamide (TAA) administration (300 mg/kg/day i.p.) for inducing HE model. At 8 h following the last injection (and every 4 h after), the grade of encephalopathy was assessed. Blood and whole brains were collected at coma for measuring CCL2 and Iba1 expression. In vitro, primary neurons were stimulated with TNF-α, and then the medium were collected for addition to microglia cultures with or without INCB or C021 pretreatment. The effect of the medium on microglia proliferation and activation was evaluated after 24 h. RESULTS: CCL2 expression and microglia activation were elevated in the cerebral cortex of rats received TAA alone. CCL2 receptors inhibition improved neurological score and reduced cortical microglia activation. In vitro, TNF-α treatment induced CCL2 release by neurons. Medium from TNF-α stimulated neurons caused microglia proliferation and M1 markers expression, including iNOS, COX2, IL-6 and IL-1ß, which could be suppressed by INCB or C021 pretreatment. The medium could also facilitate p65 nuclear translocation and IκBα phosphorylation, and NF-κB inhibition reduced the increased IL-6 and IL-1ß expression induced by the medium. CONCLUSION: Neuron-derived CCL2 contributed to microglia activation and neurological decline in HE. Blocking CCL2 or inhibiting microglia excessive activation may be potential strategies for HE.


Assuntos
Animais , Ratos , Encefalopatia Hepática/metabolismo , Microglia/metabolismo , Quimiocina CCL2/metabolismo , Receptores de Quimiocinas/antagonistas & inibidores , Neurônios/metabolismo , Tioacetamida , Expressão Gênica , Encefalopatia Hepática/induzido quimicamente , Encefalopatia Hepática/terapia , Interleucina-6/metabolismo , Microglia/efeitos dos fármacos , Quimiocina CCL2/antagonistas & inibidores , Meios de Cultura/farmacologia , Modelos Animais de Doenças , Doenças do Sistema Nervoso
20.
Sci Rep ; 6: 26460, 2016 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-27217201

RESUMO

A novel one-step hydrothermal and calcination strategy was developed to synthesize the unique 1D oriented Co3O4 crystal nanofibers with (220) facets on the carbon matrix derived from the natural, abundant and low cost wool fibers acting as both carbon precursor and template reagent. The resultant W2@Co3O4 nanocomposite exhibited very high specific capacity and favorable high-rate capability when used as anode material of lithium ion battery. The high reversible Li(+) ion storage capacity of 986 mAh g(-1) was obtained at 100 mA g(-1) after 150 cycles, higher than the theoretical capacity of Co3O4 (890 mAh g(-1)). Even at the higher current density of 1 A g(-1), the electrode could still deliver a remarkable discharge capacity of 720 mAh g(-1) over 150 cycles.

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