Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 137
Filtrar
1.
Nanoscale ; 12(3): 1994-2001, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31912077

RESUMO

As a single-elemental system, tellurium can exist stably in the form of layers with an intriguing multivalence character, which constructs a new member of the 2D family. However, the growth and electronic structure of tellurium films are still far from known at present. Here, combined with molecular beam epitaxy, scanning tunneling microscopy/spectroscopy measurements and density functional theory calculations, we report the geometric and electronic structures of tellurium grown on NbSe2 from sub-monolayer to few-layer films. At the sub-monolayer coverage, we obtain two types of adatom-induced ordered superstructures that are strongly coupled with NbSe2. With the increase in coverage, the few-layer tellurium films adopt the α-phase form, showing internal strain-induced ripple patterns in the few-layers and bulk-like in thick layers with distinct edge geometries. The band gap of α-tellurium films decreases with the increase in thickness, which is associated with notable in-gap states. These observations, corroborated with DFT calculations, emphasize the important role of the NbSe2 substrate in modulating the structural and electronic properties of tellurium films. Moreover, the interaction between tellurium adatoms and tellurium films leads to √2 × âˆš2 surface reconstruction prior to a new monolayer, conforming to our theoretical calculations. Our work clarifies the kinetic growth of tellurium films on NbSe2 and reveals the tunability of electronic properties via substrate modulation or surface decoration.

2.
Nanoscale ; 12(2): 1144-1154, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31850436

RESUMO

MoS2 is a promising anode candidate for high-performance lithium-ion batteries (LIBs) due to its unique layered structure and high specific capacity. However, the poor conductivity and unsatisfactory structural stability limit its practical application. Recently, a new class of 2D materials, V4C3-Mxene, has been found to combine metallic conductivity, high structural stability and rich surface chemistries. Herein, a facile method has been developed to fabricate V4C3-MXene/MoS2/C nanohybrids. Ultrasmall and few-layered MoS2 nanosheets are uniformly anchored on the surface of V4C3-MXene with a thin carbon-coating layer. The ultrasmall and few-layered MoS2 nanosheets can enlarge the specific areas, reduce the diffusion distance of lithium ions, and accelerate the transfer of charge carriers. As a supporting substrate, V4C3-MXene endows the nanohybrid with high electrical conductivity, strong structural stability, and fast reaction kinetics. Moreover, the carbon-coating layer can further enhance the electrical conductivity and structural stability of the hybrid material. Benefiting from these advantages, the V4C3-MXene/MoS2/C electrode shows an excellent cycling stability with a high reversible capability of 622.6 mA h g-1 at 1 A g-1 after 450 cycles, and a superior rate capability of 500.0 mA h g-1 at 10 A g-1. Thus, the V4C3-MXene/MoS2/C nanohybrid could become a promising anode material for high rate LIBs.

3.
Inorg Chem ; 58(24): 16818-16822, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31756094

RESUMO

Materials with a low coefficient of thermal expansion (CTE) are extremely demanded in many fields, varying from microelectronics to space technology. Here we report a novel method to achieve low CTE, which differs essentially from the conventional way that uses additives with negative thermal expansion (NTE) to compensate for the positive CTE of the matrix. The stoichiometric Hf0.87Ta0.13Fe2+x (x = 0) shows a giant NTE, which is gradually suppressed with increasing x and finally changed to near-zero thermal expansion (ZTE) at x ≈ 0.4. The excess Fe was suggested to form anti-site defects by occupying the 4f sites. As revealed by electron spin resonance (ESR) spectra, the weakened NTE is closely related to a slower ferromagnetic (FM) ordering process than observed at x = 0. In addition, the CTE can be further tuned by introducing an extra α-Fe phase to achieve a low CTE (e.g., 3.3 ppm/K for x = 1.0) with markedly enhanced mechanical properties, beneficial to applications.

4.
Small ; : e1903663, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31729163

RESUMO

Bismuth ferrite (BiFeO3 ) has recently become interesting as a room-temperature multiferroic material, and a variety of prototype devices have been designed based on its thin films. A low-cost and simple processing technique for large-area and high-quality BiFeO3 thin films that is compatible with current semiconductor technologies is therefore urgently needed. Development of BiFeO3 thin films is summarized with a specific focus on the chemical solution route. By a systematic analysis of the recent progress in chemical-route-derived BiFeO3 thin films, the challenges of these films are highlighted. An all-solution chemical-solution deposition (AS-CSD) for BiFeO3 thin films with different orientation epitaxial on various oxide bottom electrodes is introduced and a comprehensive study of the growth, structure, and ferroelectric properties of these films is provided. A facile low-cost route to prepare large-area high-quality epitaxial BFO thin films with a comprehensive understanding of the film thickness, stoichiometry, crystal orientation, ferroelectric properties, and bottom electrode effects on evolutions of microstructures is provided. This work paves the way for the fabrication of devices based on BiFeO3 thin films.

5.
Cancer Sci ; 110(12): 3663-3676, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31597217

RESUMO

Increasing evidence indicates that human forkhead box C1 (FOXC1) plays important roles in tumor development and metastasis. However, the underlying molecular mechanism of FOXC1 in non-small cell lung cancer (NSCLC) metastasis remains unclear. Here, we identified FOXC1 as an independent prognostic factor in NSCLC and showed clear biological implications in invasion and metastasis. FOXC1 overexpression enhanced the proliferation, migration and invasion of NSCLC cells, whereas FOXC1 silencing impaired the effects both in vitro and in vivo. Importantly, we found a positive correlation between FOXC1 expression and lysyl oxidase (LOX) expression in NSCLC cells and patient samples. Downregulation of LOX or LOX activity inhibition in NSCLC cells inhibited the FOXC1-driven effects on cellular migration and invasion. Xenograft models showed that inhibition of LOX activity by ß-aminopropionitrile monofumarate decreased the number of lung metastases. Mechanistically, we demonstrated a novel FOXC1-LOX mechanism that was involved in the invasion and metastasis of NSCLC. Dual-luciferase assay and ChIP identified that FOXC1 bound directly in the LOX promoter region and activated its transcription. Collectively, the present study offered new insight into FOXC1 in the mediation of NSCLC metastasis through interaction with the LOX promoter and further revealed that targeted inhibition of LOX protein activity could prevent lung metastasis in murine xenograft models. These data implicated FOXC1 as a potential therapeutic strategy for the treatment of NSCLC metastasis.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Fatores de Transcrição Forkhead/fisiologia , Neoplasias Pulmonares/patologia , Regiões Promotoras Genéticas , Proteína-Lisina 6-Oxidase/genética , Adulto , Idoso , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Humanos , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/secundário , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Prognóstico , Proteína-Lisina 6-Oxidase/fisiologia
7.
Biomed Pharmacother ; 120: 109444, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31562978

RESUMO

Tumor-infiltrating immune cells (TICs) are highly relevant to tumor development and are promising prognostic biomarkers. However, the precise assessment of TICs is limited by the deficiencies of traditional measurements, such as the lack of phenotypic markers. Here, we analyzed the composition of TICs in cervical cancer based on RNA expression data with a metagene approach called CIBERSORT and evaluated the prognostic value of TICs. The immune infiltration profiles functioned as intrinsic features to distinguish cervical cancer from normal tissue. According to the Cox regression analysis, higher levels of activated memory CD4+ T cells were independently associated with favorable overall survival (OS) (hazard ratio [HR] = 0.71, 95% confidence interval [CI]: 0.57-0.89; p = 0.003), whereas a higher fraction of activated mast cells was independently associated with adverse outcomes (HR = 1.53, 95% CI: 1.23-1.91; p < 0.001). Furthermore, a novel prognostic model named aTMNs (activated memory CD4+ T cells, activated mast cells and activated natural killer [NK] cells) was constructed to predict OS in cervical cancer with high accuracy (area under the curve [AUC] = 0.723, concordance index [C-index] = 0.738): risk score = -0.34508 × (proportion of activated memory CD4+ T cells) + 0.426841 × (proportion of activated mast cells) + 0.272202 × (proportion of activated NK cells). The aTMNs model outperformed the immunomodulator model (AUC = 0.673, C-index = 0.693). Overall, TICs are important prognostic determinants in cervical cancer and may be a useful resource for the development of effective immunotherapy.

8.
J Transl Med ; 17(1): 322, 2019 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-31547811

RESUMO

BACKGROUND: Recently, numerous biological experiments have indicated that microRNAs (miRNAs) play critical roles in exploring the pathogenesis of various human diseases. Since traditional experimental methods for miRNA-disease associations detection are costly and time-consuming, it becomes urgent to design efficient and robust computational techniques for identifying undiscovered interactions. METHODS: In this paper, we proposed a computation framework named weighted bipartite network projection for miRNA-disease association prediction (WBNPMD). In this method, transfer weights were constructed by combining the known miRNA and disease similarities, and the initial information was properly configured. Then the two-step bipartite network algorithm was implemented to infer potential miRNA-disease associations. RESULTS: The proposed WBNPMD was applied to the known miRNA-disease association data, and leave-one-out cross-validation (LOOCV) and fivefold cross-validation were implemented to evaluate the performance of WBNPMD. As a result, our method achieved the AUCs of 0.9321 and [Formula: see text] in LOOCV and fivefold cross-validation, and outperformed other four state-of-the-art methods. We also carried out two kinds of case studies on prostate neoplasm, colorectal neoplasm, and lung neoplasm, and most of the top 50 predicted miRNAs were confirmed to have an association with the corresponding diseases based on dbDeMC, miR2Disease, and HMDD V3.0 databases. CONCLUSIONS: The experimental results demonstrate that WBNPMD can accurately infer potential miRNA-disease associations. We anticipated that the proposed WBNPMD could serve as a powerful tool for potential miRNA-disease associations excavation.

9.
Nanoscale ; 11(28): 13343-13353, 2019 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-31271407

RESUMO

Revealing the electrochemical property-structure relationship and observing the dynamic structural evolution of electrode materials are critically important for battery performance improvement and the corresponding mechanistic understanding. Here, highly crystalline VS2 nanosheets/carbon nanotubes (CNTs) with a core/branch structure were synthesized, exhibiting reversible discharge capacity of ∼850 mA h g-1 at 200 mA g-1, high coulombic efficiency of ∼98%, good cycling stability and superior rate capability. The relationship between the electrochemical properties and the corresponding dynamic microstructural evolution was further revealed with the in situ electron microscopy technique. Our results showed that the intercalation process with the formation of amorphous LixVS2 and the subsequent conversion reactions with the formation of crystalline Li2S and V nanocrystals occurred during the discharging process. Crystalline Li2S was oxidized in the charging process. The core/branched structure ensured a large exposed surface area of the VS2 nanosheets and provided extra space to accommodate the volume expansion. Meanwhile, the CNTs surrounded by VS2 nanosheets not only provided a continuous and fast conducting pathway for carriers throughout the electrodes, but also enhanced the mechanical stability of the electrode material. These factors finally contributed to the superior electrochemical performance of the core/branch-structured VS2/CNTs electrode.

10.
Inorg Chem ; 58(14): 9036-9042, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31246443

RESUMO

An excitonic insulating (EI) state is a fantastic correlated electron phase in condensed matter physics, driven by screened electron-hole interaction. Ta2NiSe5 is an excitonic insulator with a critical temperature (TC) of 328 K. In the current study, temperature-dependent Raman spectroscopy is used to investigate the phonon vibrations in Ta2NiSe5. The following observations were made: (1) an abnormal blue shift around TC is observed, which originates from the monoclinic to orthorhombic structural phase transition; (2) the splitting of a mode and two new Raman modes at 147 and 235 cm-1 have been observed with the formation of an EI state. With the help of first-principles calculations and temperature-dependent X-ray diffraction (XRD) experiments, it is found that the TaSe6 octahedra are "frozen" and the NiSe4 tetrahedra are greatly distorted below TC. Thus, it seems that the distortion of NiSe4 tetrahedra plays an important role in the strong electron-phonon coupling (EPC) in Ta2NiSe5, while the strong EPC, coupled with electron-hole interaction, opens the energy gap to form the EI state in Ta2NiSe5.

11.
Mol Genet Genomics ; 294(6): 1477-1486, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31250107

RESUMO

Long noncoding RNAs play a significant role in the occurrence of diseases. Thus, studying the relationship prediction between lncRNAs and disease is becoming more popular. Researchers hope to determine effective treatments by revealing the occurrence and development of diseases at the molecular level. However, the traditional biological experimental way to verify the association between lncRNAs and disease is very time-consuming and expensive. Therefore, we developed a method called LLCLPLDA to predict potential lncRNA-disease associations. First, locality-constrained linear coding (LLC) is leveraged to project the features of lncRNAs and diseases to local-constraint features, and then, a label propagation (LP) strategy is used to mix up the initial association matrix and the obtained features of lncRNAs and diseases. To demonstrate the performance of our method, we compared LLCLPLDA with five methods in the leave-one-out cross-validation and fivefold cross-validation scheme, and the experimental results show that the proposed method outperforms the other five methods. Additionally, we conducted case studies on three diseases: cervical cancer, gliomas, and breast cancer. The top five predicted lncRNAs for cervical cancer and gliomas were verified, and four of the five lncRNAs for breast cancer were also confirmed.


Assuntos
Algoritmos , Doença/genética , RNA Longo não Codificante/metabolismo , Neoplasias da Mama/genética , Feminino , Glioma/genética , Humanos , Modelos Genéticos , Neoplasias do Colo do Útero/genética
12.
Lancet Oncol ; 20(6): 806-815, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31036468

RESUMO

BACKGROUND: Tucidinostat (formerly known as chidamide) is an oral subtype-selective histone deacetylase inhibitor. In an exploratory study, the combination of tucidinostat with exemestane showed preliminary signs of encouraging anti-tumour activity in patients with advanced hormone receptor-positive breast cancer. To build on these findings, we aimed to assess the efficacy and safety of this combination in a randomised trial in a larger population of postmenopausal patients with advanced, hormone receptor-positive breast cancer. METHODS: We did the randomised, double-blind, placebo-controlled, phase 3 ACE trial at 22 specialist cancer centres in China. Eligible patients were postmenopausal women (aged ≥60 years or aged <60 years if their serum follicle-stimulating hormone and oestradiol concentrations were within postmenopausal ranges) with hormone receptor-positive, HER2-negative breast cancer, whose disease had relapsed or progressed after at least one endocrine therapy (either in advanced or metastatic or adjuvant setting), and who had at least one measurable lesion, adequate organ function, Eastern Cooperative Oncology Group (ECOG) performance status of 0-1, and adequate haematological and biochemical parameters. Endocrine therapy did not have to be the most recent therapy before randomisation, but recurrence or progression after the most recent therapy was a prerequisite. Patients were randomly assigned (2:1) by a dynamic randomisation scheme via an interactive web-response system to receive 30 mg oral tucidinostat or placebo twice weekly. All patients in both groups also received 25 mg oral exemestane daily. Randomisation was stratified according to the presence of visceral metastases (yes vs no). Patients, investigators, study site staff, and the sponsor were masked to treatment assignment. The primary endpoint was investigator-assessed progression-free survival. Efficacy analyses were done in the full analysis set population, comprising all patients who received at least one dose of any study treatment, and safety analyses were done in all patients who received at least one dose of any study treatment and for whom at least one safety case report form was available. This study is registered with ClinicalTrials.gov, number NCT02482753. The study has reached the required number of events for final analysis of the primary endpoint. The trial is no longer enrolling patients, but follow-up for investigation of overall survival is ongoing. FINDINGS: Between July 20, 2015, and June 26, 2017, 365 patients were enrolled and randomly assigned, 244 to the tucidinostat group and 121 to the placebo group. The median duration of follow-up was 13·9 months (IQR 9·8-17·5). Investigator-assessed median progression-free survival was 7·4 months (95% CI 5·5-9·2) in the tucidinostat group and 3·8 months (3·7-5·5) in the placebo group (HR 0·75 [95% CI 0·58-0·98]; p=0·033). The most common grade 3 or 4 adverse events in either group were neutropenia (124 [51%] of 244 patients in the tucidinostat group vs three [2%] of 121 patients in the placebo group), thrombocytopenia (67 [27%] vs three [2%]), and leucopenia (46 [19%] vs three [2%]). Serious adverse events of any cause occurred in 51 (21%) of 244 patients in the tucidinostat group and seven (6%) of 121 patients in the placebo group. No treatment-related deaths were reported. INTERPRETATION: Tucidinostat plus exemestane improved progression-free survival compared with placebo plus exemestane in patients with advanced, hormone receptor-positive, HER2-negative breast cancer that progressed after previous endocrine therapy. Grade 3-4 haematological adverse events were more common in the tucidinostat plus exemestane group than in the placebo plus exemestane group. Tucidinostat plus exemestane could represent a new treatment option for these patients. FUNDING: Chipscreen Biosciences.

13.
Front Genet ; 10: 343, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31057602

RESUMO

According to the latest research, lncRNAs (long non-coding RNAs) play a broad and important role in various biological processes by interacting with proteins. However, identifying whether proteins interact with a specific lncRNA through biological experimental methods is difficult, costly, and time-consuming. Thus, many bioinformatics computational methods have been proposed to predict lncRNA-protein interactions. In this paper, we proposed a novel approach called Long non-coding RNA-Protein Interaction Prediction based on Improved Bipartite Network Recommender Algorithm (LPI-IBNRA). In the proposed method, we implemented a two-round resource allocation and eliminated the second-order correlations appropriately on the bipartite network. Experimental results illustrate that LPI-IBNRA outperforms five previous methods, with the AUC values of 0.8932 in leave-one-out cross validation (LOOCV) and 0.8819 ± 0.0052 in 10-fold cross validation, respectively. In addition, case studies on four lncRNAs were carried out to show the predictive power of LPI-IBNRA.

14.
Curr Med Sci ; 39(2): 243-249, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31016517

RESUMO

EN: Summary]This study aimed to test the effects of five single nucleotide polymorphisms within SLC2A9 on uric acid level in a special ethnic population, the Uygurs in Xinjiang, China. According to our inclusion and exclusion criteria, Uygur adults from Xinjiang constituted the study population. There were 1053 Uygur adults with hyperuricemia and 1373 normal Uygur adults who served as controls. Five single nucleotide polymorphisms within SLC2A9 (rs938557, rs7679916, rs7349721, rs13101785, and rs13137343) were selected with the HapMap dataset and TaqMan assays. We found that, in normouricemia group, rs938557 was significantly correlated with uric acid (ß=11.39±3.74, P=0.0024) adjusting for age, gender and BMI; rs7679916 and rs13137343 were marginally associated with uric acid concentration (ß=5.77±3.09, P=0.0626; ß= 5.99±3.08, P=0.0520). In the hyperuricemia group, no SNP was found to possibly influence uric acid concentration. None of these SNPs showed significant association with hyperuricemia after controlling for age, gender and BMI. There were significant or marginal correlations between certain single nucleotide polymorphisms in the SLC2A9 region and uric acid concentration in Uygur normouricemia samples. In turn, some of these single nucleotide polymorphisms in SLC2A9 may increase the risk of hyperuricemia.


Assuntos
Predisposição Genética para Doença/genética , Proteínas Facilitadoras de Transporte de Glucose/genética , Hiperuricemia/genética , Polimorfismo de Nucleotídeo Único/genética , Adulto , Grupo com Ancestrais do Continente Asiático/genética , China , Estudos Transversais , Feminino , Frequência do Gene/genética , Humanos , Hiperuricemia/metabolismo , Masculino , Pessoa de Meia-Idade , Ácido Úrico/metabolismo
15.
Int J Syst Evol Microbiol ; 69(6): 1760-1766, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30950783

RESUMO

A motile, Gram-stain-negative, fusiform-shaped bacterium, designated strain T3T, was isolated from rhizosphere soil of Alhagi sparsifolia, collected from Xinjiang, PR China. Strain T3T grew at 15-42 °C, pH 4-9 and 1-6 % (w/v) NaCl concentrations. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain T3T belonged to the genus Pseudomonas and showed highest similarity of 98.6 % to Pseudomonas azotifigens JCM 12708T, followed by Pseudomonas balearica DSM 6083T (97.8 %), Pseudomonas matsuisoli JCM 30078T (97.7 %), Pseudomonas furukawaii KF707T (97.7 %), Pseudomonas tarimensis CCTCC AB 2013065T (97.3 %) and Pseudomonas indica DSM 14015T (97.1 %). Analysis based on concatenated gene sequences of 16S rRNA, rpoB and gyrB further confirmed the phylogenetic assignment of strain T3T. The Genome-to-Genome Distance Calculator results for P. azotifigens JCM12708T and P. balearica DSM 6083T were 28.7±4.4% and 24.1±2.4 %, and the average nucleotide identity scores were 81.3 and 78.1 %. The major polar lipids of strain T3T were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The predominant quinone was Q-9. The major fatty acids comprised summed feature 8 (C18 : 1ω6c/C18 : 1ω7c; 37.7 %), summed feature 3 (C16 : 1ω6c/C16 : 1ω7c; 28.2 %), C16 : 0 (15.6 %), C12 : 0 (7.8 %), C10 : 03-OH (3.0 %) and C12 : 03-OH (2.6 %). The G+C content of the genomic DNA of the type strain was 65.3 mol%. It is obvious from the phylogenetic, phenotypic and chemotaxonomic data that strain T3T represents a novel species of the genus Pseudomonas, for which the name Pseudomonasurumqiensis sp. nov., is proposed. The type strain is T3T (=ACCC 60124T=JCM 32830T).


Assuntos
Fabaceae/microbiologia , Filogenia , Pseudomonas/classificação , Rizosfera , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Genes Bacterianos , Fosfolipídeos/química , Pseudomonas/isolamento & purificação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
16.
Int J Oncol ; 54(6): 1943-1954, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30942436

RESUMO

Immunoglobulin­like transcript (ILT) 4, a negative regulator of immune response in allograft rejection, autoimmunity and infectious diseases, has recently been determined to serve important roles in tumor development. In the present study, the co­expression of ILT4 and human leukocyte antigen­G (HLA­G) in tissues of human primary colorectal cancer (CRC) was revealed, and its association with older age, advanced stage, regional lymph node involvement and poor overall survival time was identified. In CRC cell lines, ILT4 and HLA­G co­expression and their autocrine regulation was demonstrated. ILT4 interference affected HLA­G expression and regulated the cell proliferation, invasion and migration of CRC. HLA­G fusion protein treatment also increased ILT4 expression in a dose­dependent manner, thereby activating protein kinase B (AKT) and extracellular signal­regulated kinase (ERK) signaling, and facilitating the proliferation, migration and invasion of CRC cells. Additionally, the AKT and ERK activation, and CRC cell malignant characteristics induced by HLA­G may be suppressed by blocking ILT4. The present results indicated that the interaction of ILT4 and its ligand HLA­G promotes CRC progression through AKT and ERK signal activation, providing a novel strategy of blocking ILT4/HLA­G for the treatment of CRC.


Assuntos
Neoplasias Colorretais/patologia , Antígenos HLA-G/metabolismo , Metástase Linfática/patologia , Glicoproteínas de Membrana/metabolismo , Receptores Imunológicos/metabolismo , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral , Colo/patologia , Neoplasias Colorretais/mortalidade , Progressão da Doença , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Humanos , Ligantes , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Proteínas Proto-Oncogênicas c-akt/metabolismo , Reto/patologia , Transdução de Sinais , Análise de Sobrevida , Fatores de Tempo , Adulto Jovem
17.
Phys Chem Chem Phys ; 21(14): 7288-7297, 2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-30892328

RESUMO

Circularly polarized luminescence molecules with both thermally activated delayed fluorescence (TADF) and aggregation-induced emission (AIE) have been reported recently and are thought as potential candidates for circular polarized organic light-emitting diodes. Since the study of these kinds of systems is quite limited, it is of great importance to reveal the relationship between the geometry and the light-emitting mechanism. In this paper, the TADF and AIE mechanisms were studied based on the study of a series of binaphthalene-containing luminogenic enantiomers in both toluene and solid phases. It was found that there was no influence on the light-emitting properties of enantiomers except for the electronic circular dichroism (ECD). The radiative rates for both molecules were enhanced in the solid phase, while the non-radiative rates were significantly suppressed. Both factors can induce the AIE phenomenon. Based on the calculation of the decay rates and adiabatic excitation energy of the excited states, we found that the TADF mechanisms of the two molecules were different. One is realized by the up-conversion process between S1 and T1, while a two-step process is involved for the other. Our theoretical research successfully elucidates the experimental measurement and illustrates the AIE and TADF mechanism, which could provide valuable insights for the design of highly efficient CPL emitters.

18.
Nanomaterials (Basel) ; 9(3)2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30875915

RESUMO

A low-cost and high-performance gas sensor was fabricated by the in-situ growing of ZnO nanoclusters (NCs) arrays on the etched fluorine-doped tin dioxide (FTO) glass via a facile dip-coating and hydrothermal method. Etched FTO glass was used as a new-type gas-sensing electrode due to its advantages of being low cost and having excellent thermal and chemical stability. ZnO NCs are composed of multiple ZnO nanorods and can provide adequate lateral contacts to constitute the paths required for the gas-sensing tests simultaneously, which can provide many advantageous point junctions for the detection of low-concentration gases. The gas-sensing tests indicate that the ZnO NCs gas sensor has good selectivity and a high response for the low-concentration H2S gas. The sensing response has reached 3.3 for 500 ppb H2S at 330 °C. The excellent gas-sensing performances should be attributed to the large specific surface area of in-situ grown ZnO NCs, the perfect ohmic contact between ZnO NCs and FTO electrode and the variation of grain boundary barrier at the cross-linked junctions of multiple nanorods. In addition, the detailed effect of work temperature and gas concentration on gas-sensing, the stability of gas sensors and the corresponding response mechanism are also discussed in the present paper.

19.
Small ; 15(14): e1805420, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30848553

RESUMO

1T phase MoS2 possesses higher conductivity than the 2H phase, which is a key parameter of electrochemical performance for lithium ion batteries (LIBs). Herein, a 1T-MoS2 /C hybrid is successfully synthesized through facile hydrothermal method with a proper glucose additive. The synthesized hybrid material is composed of smaller and fewer-layer 1T-MoS2 nanosheets covered by thin carbon layers with an enlarged interlayer spacing of 0.94 nm. When it is used as an anode material for LIBs, the enlarged interlayer spacing facilitates rapid intercalating and deintercalating of lithium ions and accommodates volume change during cycling. The high intrinsic conductivity of 1T-MoS2 also contributes to a faster transfer of lithium ions and electrons. Moreover, much smaller and fewer-layer nanosheets can shorten the diffusion path of lithium ions and accelerate reaction kinetics, leading to an improved electrochemical performance. It delivers a high initial capacity of 920.6 mAh g-1 at 1 A g-1 and the capacity can maintain 870 mAh g-1 even after 300 cycles, showing a superior cycling stability. The electrode presents a high rate performance as well with a reversible capacity of 600 mAh g-1 at 10 A g-1 . These results show that the 1T-MoS2 /C hybrid shows potential for use in high-performance lithium-ion batteries.

20.
ACS Nano ; 13(2): 1694-1702, 2019 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-30649862

RESUMO

The phase-controlled synthesis of metallic and ambient-stable 2D MX2 (M is Mo or W; X is S) with 1T octahedral coordination will endow these materials with superior performance compared with their semiconducting 2H coordination counterparts. We report a clean and facile route to prepare 1T-MoS2 and 1T-WS2 through hydrothermal processing under high magnetic fields. We reveal that the as-synthesized 1T-MoS2 and 1T-WS2 are ambient-stable for more than 1 year. Electrochemical measurements show that 1T-MoS2 performs much better than 2H-MoS2 as the anode for sodium ion batteries. These results can provide a clean and facile method to prepare ambient-stable 1T-phase MX2.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA