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1.
Neoplasma ; 70(4): 566-579, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37789781

RESUMO

Existing evidences have revealed the crucial roles of E2 promoter binding factor-1 (E2F1) during the tumorigenesis and progression process of multiple human tumors. However, the expression patterns, biological functions, as well as the underlying molecular mechanism of E2F1 in endometrial carcinoma yet remain largely unclear. The expression patterns and clinical prognostic value of E2F1 in endometrial carcinoma were evaluated using bioinformatics methods. Protein and mRNA, miRNA expression levels in tissues and cells were measured using immunohistochemistry, western blotting, and qRT-PCR assays. Cell viability and cell cycle distribution were examined using CCK-8 assay and flow cytometry, respectively. Scratch healing assay and Transwell assay were applied to measure cell migration and invasion ability. Bioinformatic analysis and luciferase reporter assays were conducted to confirm the targeting relationship between E2F1 and miR-329-3p. Moreover, a series of in vitro and in vivo functional experiments were employed to evaluate the effect of the miR-329-3p/E2F1 axis on cell growth and metastasis. Clinically, E2F1 was aberrantly expressed in endometrial carcinoma tissues and was correlated with advanced FIGO stage, histological type, p53 mutation, poor survival, and degree of tumor cell differentiation. ROC curves analysis also reveals that E2F1 has a high AUC value (up to 0.952, 95% CI: 0.915-0.988), indicating the promising diagnostic value of E2F1 level in endometrial carcinoma. In addition, in vitro gain and loss-of-functional experiments verified that high E2F1 can promote cell proliferation, cell cycle, migration, invasion, and EMT process. In-depth mechanism studies revealed that E2F1 was a downstream target gene of miR-329-3p, and miR-329-3p overexpression could effectively abrogate its promotion of cell malignant biological behavior. Collectively, our findings suggested that the miR-329-3p/E2F1 axis plays a crucial role in the progression of endometrial carcinoma, indicating that E2F1 can be considered a promising diagnostic and prognostic biomarker for endometrial carcinoma patients.


Assuntos
Neoplasias do Endométrio , MicroRNAs , Feminino , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Linhagem Celular Tumoral , Transformação Celular Neoplásica/genética , Proliferação de Células/genética , Movimento Celular/genética , Neoplasias do Endométrio/genética , Regulação Neoplásica da Expressão Gênica , Fator de Transcrição E2F1/genética
2.
Oncol Rep ; 49(5)2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37052291

RESUMO

Uterine corpus endometrial carcinoma (UCEC) is a common gynecological malignancy with high rates of mortality and morbidity. The expression of long non­coding RNA bladder cancer­associated transcript 2 (BLACAT2) has been previously found to be aberrantly upregulated in UCEC. However, the regulatory consequences of this in UCEC progression remain poorly understood. In the present study, human UCEC cell lines AN3CA and HEC­1­A were infected with lentiviruses to overexpress BLACAT2 (Lv­BLACAT2) or knock down BLACAT2 using short hairpin RNA (Lv­shBLACAT2). BLACAT2 overexpression was found to promote the G1/S transition of cell cycle progression and UCEC cell proliferation. In addition, BLACAT2 overexpression was observed to facilitate UCEC cell migration and invasion. By contrast, BLACAT2 knockdown resulted in inhibitory effects in UCEC cell physiology. BLACAT2 overexpression also contributed to the activation of the MEK/ERK pathway. Subsequently, BLACAT2 was demonstrated to bind to microRNA (miR)­378a­3p according to dual­luciferase assays, where it appeared to function as a sponge of miR­378a­3p in 293T cells. miR­378a­3p overexpression was found to suppress UCEC cell proliferation, invasion, and ERK activation. Lentivirus­mediated knockdown of its target, the transcription factor Yin Yang­1 (YY1), was observed to reverse the oncogenic effects of BLACAT2 overexpression. Furthermore, YY1 was found to bind to the promoter of BLACAT2, suggesting that YY1 can regulate BLACAT2 expression. To conclude, results from the present study suggest that BLACAT2, miR­378a­3p and YY1 can form a feedback loop instead of an unidirectional axis, which can in turn regulate UCEC tumorigenesis through the MEK/ERK pathway. The present study furthered the understanding of UCEC tumorigenesis and may provide novel therapeutic targets for UCEC treatment.


Assuntos
Carcinoma Endometrioide , Neoplasias do Endométrio , MicroRNAs , RNA Longo não Codificante , Neoplasias da Bexiga Urinária , Feminino , Humanos , RNA Longo não Codificante/genética , Retroalimentação , Carcinoma Endometrioide/genética , Proliferação de Células/genética , Neoplasias da Bexiga Urinária/genética , Carcinogênese/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Neoplasias do Endométrio/patologia , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Fator de Transcrição YY1/genética , Fator de Transcrição YY1/metabolismo
3.
Water Sci Technol ; 87(4): 834-851, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36853765

RESUMO

The experimental and theoretical studies on the adsorption of Cu(II) on the surface of Na-montmorillonite (Na-Mt) were reported. Effects of batch adsorption experimental parameters were studied. Density functional theory and molecular dynamics simulations were used to study the adsorption of Cu(II) on montmorillonite (001) surface. The adsorption reached equilibrium within 80 min and the adsorption capacity was 35.23 mg·g-1 at 25 °C. The adsorption data of Cu(II) were consistent with pseudo-second-order kinetics and Langmuir isotherm models. The adsorption process was dominated by physical adsorption (Ea was 37.08 kJ·mol-1) with spontaneous endothermic behavior. The influence of coexisting cations on the adsorption capacity of Cu(II) was Mg(II) > Co(II) > Ca(II) > Na(I). The simulation results demonstrated that there were no significant differences in the adsorption energy of Cu(II) at the four adsorption sites on the montmorillonite (001) surface. Cu(II) had more electron transfer than Na(I). The diffusion coefficient of Cu(II) in the aqueous solution system containing montmorillonite was 0.85×10-10 m2·s-1. Considerable amounts of Cu(II) ions were adsorbed at a distance of 0.26 and 2.25 Å from the montmorillonite (001) surface. The simulation results provided strong supporting evidence for experimental conclusions.


Assuntos
Bentonita , Íons , Adsorção , Simulação por Computador , Cinética
4.
Artigo em Inglês | MEDLINE | ID: mdl-35897506

RESUMO

In view of the pedestrian space violation in an advance right-turn lane, the pedestrian crossing paths are divided by collecting the temporal and spatial information of pedestrians and motor vehicles, and the characteristics of different pedestrian crossing behaviors are studied. Combined with the time and speed indicators of conflict severity, the K-means method is used to divide the level of conflict severity. A multivariate ordered logistic regression model of the severity of pedestrian-vehicle conflict was constructed to quantify the effects of different factors on the severity of the pedestrian-vehicle conflict. The study of 1388 pedestrians and the resulting pedestrian-vehicle conflicts found that the type of spatial violation has a significant impact on pedestrian crossing behavior and safety. The average crossing speed and acceleration variation values of spatially violated pedestrians were significantly higher than those of other pedestrians; there is a significant increase in the severity of pedestrian-vehicle conflicts in areas close to the oncoming traffic; the average percentage of pedestrian-vehicle conflicts due to spatial violations increased by 12%, and the percentage of serious conflicts due to each type of spatial violation increased from 18% to 87%, 74%, 30%, and 63%, respectively, compared with those of non-violated pedestrians. In addition, the decrease in the number of lanes and the increase in speed and vehicle reach all lead to an increase in the severity of pedestrian-vehicle conflicts. The results of the study will help traffic authorities to take measures to ensure pedestrian crossing safety.


Assuntos
Pedestres , Acidentes de Trânsito , Humanos , Veículos Automotores , Segurança , Caminhada
5.
J Am Chem Soc ; 144(13): 6091-6099, 2022 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-35316600

RESUMO

Synthesis of hierarchically porous structures with uniform spatial gradient and structure reinforcement effect still remains a great challenge. Herein, we report the synthesis of zeolite@mesoporous silica core-shell nanospheres (ZeoA@MesoS) with a gradient porous structure through a micellar dynamic assembly strategy. In this case, we find that the size of composite micelles can be dynamically changed with the increase of swelling agents, which in situ act as the building blocks for the modular assembly of gradient mesostructures. The ZeoA@MesoS nanospheres are highly dispersed in solvents with uniform micropores in the inner core and a gradient tubular mesopore shell. As a nanoreactor, such hierarchically gradient porous structures enable the capillary-directed fast mass transfer from the solutions to inner active sites. As a result, the ZeoA@MesoS catalysts deliver a fabulous catalytic yield of ∼75% on the esterification of long-chain carboxylic palmitic acids and high stability even toward water interference, which can be well trapped by the ZeoA core, pushing forward the chemical equilibrium. Moreover, a very remarkable catalytic conversion on the C-H arylation reaction of large N-methylindole is achieved (∼98%) by a Pd-immobilized ZeoA@MesoS catalyst. The water tolerance feature gives a notable enhancement of 26% in catalytic yield compared to the Pd-dendritic mesoporous silica without the zeolite core.


Assuntos
Nanosferas , Catálise , Micelas , Nanosferas/química , Porosidade , Dióxido de Silício/química
6.
Opt Express ; 29(21): 34166-34174, 2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34809213

RESUMO

Broadband emission was obtained over 2.6 to 4.1 µm (Pr3+: 1G4→3F4, 3F3) in AlF3-based glass samples doped with different concentrations of praseodymium and 1 mol% ytterbium using a 976 nm laser pump. An efficient energy transfer process from Yb3+: 2F5/2 to Pr3+: 1G4 was analyzed through emission spectra and fluorescence lifetime values. The absorption and emission cross-sections were calculated by Füchtbauer-Ladenburg and McCumber theories and a positive gain can be obtained when P>0.3. To the best of the authors' knowledge, this work represents the first report of broadband mid-infrared emission of Pr3+ in an AlF3-based glass. The results show that praseodymium doped AlF3-based glass sensitized by ytterbium could be a promising candidate for fiber lasers operating in mid-infrared region.

7.
J Am Chem Soc ; 143(35): 14097-14105, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34379403

RESUMO

Surface redox pseudocapacitance, which enables short charging times and high power delivery, is very attractive in a wide range of sites. To achieve maximized specific capacity, nanostructuring of active materials with high surface area is indispensable. However, one key limitation for capacitive materials is their low volumetric capacity due to the low tap density of nanomaterials. Here, we present a promising mesoscale TiO2 structure with precisely controlled mesoporous frameworks as a high-density pseudocapacitive model system. The dense-packed mesoscopic TiO2 in micrometer size offers a high accessible surface area (124 m2 g-1) and radially aligned mesopore channels, but high tap density (1.7 g cm-3) that is much higher than TiO2 nanoparticles (0.47 g cm-3). As a pseudocapacitive sodium-ion storage anode, the precisely designed mesoscopic TiO2 model achieved maximized gravimetric capacity (240 mAh g-1) and volumetric capacity (350 mAh cm-3) at 0.025 A g-1. Such a designed pseudocapacitive mesostructure further realized a commercially comparable areal capacity (2.1 mAh cm-2) at a high mass loading of 9.47 mg cm-2. This mesostructured electrode that enables fast sodiation in dense nanostructures has implications for high-power applications, fast-charging devices, and pseudocapacitive electrode design.

8.
ACS Nano ; 15(4): 7713-7721, 2021 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-33821624

RESUMO

Two-dimensional carbon materials, incorporating a large mesoporosity, are attracting considerable research interest in various fields such as catalysis, electrochemistry, and energy-related technologies owing to their integrated functionalities. However, their potential applications, which require favorable mass transport within mesopore channels, are constrained by the undesirable and finite mesostructural configurations due to the immense synthetic difficulties. Herein, we demonstrate an oriented monomicelle assembly strategy, for the facile fabrication of highly ordered mesoporous carbon thin films with vertically aligned and permeable mesopore channels. Such a facile and reproducible approach relies on the swelling and fusion effect of hydrophobic benzene homologues for directional monomicelle assembly. The orientation assembly process shows precise controllability and great universality, affording mesoporous carbon films with a cracking-free structure over a centimeter in size, highly tunable thicknesses (13 to 85 nm, an interval of ∼12 nm), mesopore size (8.4 to 13.5 nm), and switchable growth substrates. Owing to their large permeable mesopore channels, electrochemical sensors based on vertical mesoporous carbon films exhibit an ultralow limit of detection (50 nmol L-1) and great sensitivity in dopamine detection.

9.
Opt Lett ; 46(9): 2031-2034, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33929411

RESUMO

The use of Eu3+ codoping for enhancing the Ho3+:5I5→5I6 emission in fluoroindate glasses shows that Eu3+ could depopulate the lower laser state Ho3+:5I6 while having little effect on the upper state Ho3+:5I5, resulting in greater population inversion. The Ho3+/Eu3+ codoped glass has high spontaneous transition probability (6.31s-1) together with large emission cross section (7.68×10-21cm2). This study indicates that codoping of Ho3+ with Eu3+ is a feasible alternative to quench the lower energy level of the 3.9 µm emission and the Ho3+/Eu3+ codoped fluoroindate glass is a promising material for efficient 3.9 µm fiber lasers.

10.
Front Oncol ; 11: 622805, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33763357

RESUMO

Alternative splicing (AS) is significantly related to the development of tumor and the clinical outcome of patients. In this study, our aim was to systematically analyze the survival-related AS signal in ovarian serous cystadenocarcinoma (OV) and estimate its prognostic validity in 48,049 AS events out of 21,854 genes. We studied 1,429 AS events out of 1,125 genes, which were significantly related to the overall survival (OS) in patients with OV. We established alternative splicing features on the basis of seven AS events and constructed a new comprehensive prognostic model. Kaplan-Meier curve analysis showed that seven AS characteristics and comprehensive prognostic models could strongly stratify patients with ovarian cancer and make them distinctive prognosis. ROC analysis from 0.781 to 0.888 showed that these models were highly efficient in distinguishing patient survival. We also verified the prognostic characteristics of these models in a testing cohort. In addition, uni-variate and multivariate Cox analysis showed that these models were superior independent risk factors for OS in patients with OV. Interestingly, AS events and splicing factor (SFs) networks revealed an important link between these prognostic alternative splicing genes and splicing factors. We also found that the comprehensive prognosis model signature had higher prediction ability than the mRNA signature. In summary, our study provided a possible prognostic prediction model for patients with OV and revealed the splicing network between AS and SFs, which could be used as a potential predictor and therapeutic target for patients with OV.

11.
Opt Lett ; 45(15): 4272-4275, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32735278

RESUMO

Intense mid-infrared emission at 3.9 µm in Ho3+-doped ZBYA glasses with direct upper laser level (Ho3+:5I5) pumping at a wavelength of 888 nm is reported for the first time, to the best of our knowledge. Spectroscopic parameters were determined using the Judd-Ofelt theory and the measured absorption spectrum. The maximum emission cross section of the Ho3+-doped ZBYA glass is estimated to be 2.7×10-21cm2 at 3906 nm. Additionally, fluorescence spectra and lifetimes of ZBYA glasses with different Ho3+ ion doping concentrations were measured. The results provide theoretical and experimental basis for better selection of rare-earth-doped matrix glasses to achieve a fluorescence output centered on a wavelength of 3.9 µm.

12.
Angew Chem Int Ed Engl ; 59(40): 17676-17683, 2020 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-32632999

RESUMO

By introducing a compatible reducing agent (2-ethylimidazole) into a mono-micelle assembly process, we present a type of ordered mesoporous TiO2 microspheres that combines radially aligned mesostructure with Ti3+ defects in mesoporous frameworks. Such reductant acts as a building block of mesostructured frameworks and reduces Ti4+ in situ to generate defects during calcination, giving rise to the coexistence of bulk Ti3+ defects and an ordered mesostructure. The mesoporous TiO2 has both excellent mesoporosity (a high surface area of 106 m2 g-1 , a mean pore size of 18.4 nm) and stable defects with an extended photoresponse. Such integration of unique mesoscopic architecture and atomic vacancies provide both effective mass transportation and enhanced light utilization, leading to a remarkable increase in H2 generation rate. A maximum H2 evolution rate of 19.8 mmol g-1 h-1 can be achieved, along with outstanding stability under solar light.

13.
Nature ; 580(7803): 386-390, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32296174

RESUMO

The aetiology of inflammatory bowel disease (IBD) is a multifactorial interplay between heredity and environment1,2. Here we report that deficiency in SETDB1, a histone methyltransferase that mediates the trimethylation of histone H3 at lysine 9, participates in the pathogenesis of IBD. We found that levels of SETDB1 are decreased in patients with IBD, and that mice with reduced SETDB1 in intestinal stem cells developed spontaneous terminal ileitis and colitis. SETDB1 safeguards genome stability3, and the loss of SETDB1 in intestinal stem cells released repression of endogenous retroviruses (retrovirus-like elements with long repeats that, in humans, comprise approximately 8% of the genome). Excessive viral mimicry generated by motivated endogenous retroviruses triggered Z-DNA-binding protein 1 (ZBP1)-dependent necroptosis, which irreversibly disrupted homeostasis of the epithelial barrier and promoted bowel inflammation. Genome instability, reactive endogenous retroviruses, upregulation of ZBP1 and necroptosis were all seen in patients with IBD. Pharmaceutical inhibition of RIP3 showed a curative effect in SETDB1-deficient mice, which suggests that targeting necroptosis of intestinal stem cells may represent an approach for the treatment of severe IBD.


Assuntos
Instabilidade Genômica , Histona-Lisina N-Metiltransferase/metabolismo , Doenças Inflamatórias Intestinais/metabolismo , Necroptose , Células-Tronco/metabolismo , Animais , Histona-Lisina N-Metiltransferase/genética , Humanos , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/patologia , Camundongos , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Células-Tronco/citologia
14.
J Am Chem Soc ; 141(42): 16755-16762, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31564098

RESUMO

Two-dimensional (2D) heterostructures endowed with mesoporosities offer exciting opportunities in electrocatalysis, photocatalysis, energy storage, and conversion technologies due to their integrated functionalities, abundant active sites and shortened diffusion distance. However, layered mesostructures have not been combined due to the immense difficulties by conventional chemical, mechanical exfoliation or self-assembly approaches. Herein, we explore a bottom-up strategy, carried out under mild conditions, for the facile synthesis of monolayered mesoporous-titania-mesoporous-carbon vertical heterostructure with uniform mesopore size, which enables ultrahigh rate capability and cycling longevity for pseudocapacitive sodium-ion storage in nonaqueous electrolyte. Such a brand-new type of heterostructure consists of well-ordered monolayered mesoporous titania nanosheets and surrounding two mesoporous carbon monolayers assembled at both sides. Remarkably, the combination of interconnected large mesoporosity and heterointerface leads to highly promoted reversible pseudocapacitance (96.4% of total charge storage at a sweep rate of 1 mV s-1), and it enables the material to retain strong mechanical stability during the rapid sodiation and desodiation processes. This study reveals the importance of incorporating mesopores into heterointerface as a strategy for enhancing charge storage kinetics of electroactive materials.

15.
ChemSusChem ; 12(15): 3541-3549, 2019 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-31116496

RESUMO

Facile synthesis of ultrahigh surface area porous carbons with well-defined functionalities such as N-doping remains a formidable challenge as extensive pore creation results in significant damage to the active sites. Herein, an ultrahigh surface area, N-doped hierarchically porous carbon was prepared through a multicomponent co-assembly approach. The resultant N-doped hierarchically porous carbon (N-HPC) possessed an ultrahigh surface area (≈1960 m2 g-1 ), a uniform interpenetrating micropore (≈1.3 nm) and large mesopore (≈7.6 nm) size, and high N-doping in the carbon frameworks (≈5 wt %). The N-HPC exhibited a high specific capacitance (358 F g-1 at 0.5 A g-1 ) as a supercapacitor electrode in aqueous alkaline electrolyte with a stable cycling performance after10 000 charge/discharge cycles. Moreover, as a CO2 absorbent, N-HPC displayed an adsorption capacity of 29.0 mmol g-1 at 0 °C under a high pressure of 30 bar.

16.
J Am Chem Soc ; 140(11): 4135-4143, 2018 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-29505721

RESUMO

Two-dimensional (2D) nanomaterials have been the focus of substantial research interest recently owing to their fascinating and excellent properties. However, 2D porous materials have remained quite rare due to the difficulty of creating pores in 2D nanostructures. Here, we have synthesized a novel type of single-layered 2D mesoporous TiO2 nanosheets with very uniform size and thickness as well as ordered mesostructure from an unprecedented hydrothermal-induced solvent-confined assembly approach. The F127/TiO2 spherical monomicelles are first formed and redispersed in ethanol and glycerol, followed by a hydrothermal treatment to assemble these subunits into single-layered 2D mesostructure owing to the confinement effect of highly adhered glycerol solvent. The obtained 2D mesoporous TiO2 nanosheets have a relative mean size at around 500 × 500 nm and can be randomly stacked into a bulk. The TiO2 nanosheets possess only one layer of ordered mesopores with a pore size of 4.0 nm, a very high surface area of 210 m2 g-1 and a uniform thickness of 5.5 nm. The thickness can be further manipulated from 5.5 to 27.6 nm via simply tuning precursor concentration or solvent ratio. Due to the well-defined 2D morphology and large mesoporosity as well as crystalline anatase mesopore walls, these uniform TiO2 nanosheets are capable of providing large accessible voids for sodium ion adsorption and intercalation as well as preventing volume expansion. As expected, these mesoporous TiO2 nanosheets have exhibited an excellent reversible capacity of 220 mAh g-1 at 100 mA g-1 as sodium-ion battery anodes, and they can retain at 199 mAh g-1 after numerous cycles at different current densities. The capacity is retained at 44 mAh g-1 even at a large current density of 10 A g-1 after 10 000 cycles, demonstrating a remarkable performance for energy storage.

17.
Soft Matter ; 13(44): 8136-8143, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-29075702

RESUMO

Polymers exhibiting an abnormal thermoresponsive behaviour, in which increase in the polymer concentration in water leads to an increase in the phase transition temperature, are few, and no plausible strategy has been addressed to prepare these polymers. For illuminating a feasible common strategy to prepare polymers with an abnormal thermoresponsive behaviour, in this study, we systematically prepared a series of hyperbranched polyglycerol (HPG) derivatives through a facile esterification reaction between HPG and aliphatic acids having different carbon numbers (X). Turbidimetry measurements demonstrate that thermoresponsive HPGs can be obtained only when HPGs are conjugated with aliphatic units of X ≤ 8. The conjugation of HPG with aliphatic units of X ≤ 4 resulted in thermoresponsive HPGs with a normal thermoresponsive behaviour. For the preparation of thermoresponsive HPGs with an abnormal thermoresponsive behaviour, X should be controlled in the range of 5-8. Fluorescence measurements with nile red as the fluorescent probe demonstrate that the existence of relatively strong hydrophobic interaction is a key factor to ensure that the polymer exhibits an abnormal thermoresponsive behaviour in water. Moreover, turbidimetry and fluorescence techniques are complementary for measuring the phase transition behaviour and suitable for different polymer concentration regions.

18.
J Am Chem Soc ; 139(1): 517-526, 2017 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-27936657

RESUMO

Constructing three-dimensional (3-D) hierarchical mesostructures with unique morphology, pore orientation, single-crystal nature, and functionality remains a great challenge in materials science. Here, we report a confined microemulsion self-assembly approach to synthesize an unprecedented type of 3-D highly ordered mesoporous TiO2 superstructure (Level-1), which consists of 1 spherical core and 12 symmetric satellite hemispheres epitaxially growing out of the core vertices. A more complex and asymmetric TiO2 superstructure (Level-2) with 13 spherical cores and up to 44 symmetric satellite hemispheres can also be well manipulated by increasing the size or content of impregnated TiO2 precursor emulsion droplets. The obtained 3-D mesoporous TiO2 superstructures have well-defined bouquet-posy-like topologies, oriented hexagonal mesochannels, high accessible surface area (134-148 m2/g), large pore volume (0.48-0.51 cm3/g), and well single-crystalline anatase walls with dominant (001) active facets. More interestingly, all cylindrical mesopore channels are highly interconnected and radially distributed within the whole superstructures, and all TiO2 nanocrystal building blocks are oriented grown into a single-crystal anatase wall, making them ideal candidates for various applications ranging from catalysis to optoelectronics. As expected, the bouquet-posy-like mesoporous TiO2 superstructure supported catalysts show excellent catalytic activity (≥99.7%) and selectivity (≥96%) in cis-semihydrogenation of various alkynes, exceeding that of commercial TiO2 (P25) supported catalyst by a factor of 10. No decay in the activity was observed for 25 cycles, revealing a high stability of the mesoporous TiO2 superstructure supported catalyst.

19.
Mol Phylogenet Evol ; 100: 80-94, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27058122

RESUMO

Sinopotamon Bott, 1967 is the most speciose and widely distributed freshwater crab genus in East Asia. Our extensive sampling includes about 76% of the known Sinopotamon taxa, and nearly covers its entire distribution area. Based on mitochondrial cytochrome oxidase I (COI) and 16S rRNA, as well as nuclear 28S rRNA and histone H3, we reconstructed the Sinopotamon phylogeny using maximum likelihood and Bayesian approaches. The divergence time was estimated and multiple methods were used to conduct diversification analyses. The ancestral geographic distribution and character state were reconstructed. Three main clades (Clades I, II and III) that roughly correspond to their main geographic distribution ranges were recovered. Our results challenge the current view of the four major species groups based on the morphological differences in the male first gonopod (G1). The most recent common ancestor of Sinopotamon most likely originated from the Sichuan Basin and surrounding mountains (SBSM) and subsequently dispersed throughout central and eastern China. The exceptionally rapid, recent diversification was detected in Clade II. The high incidence of species-level non-monophyly found in Clade II can be explained by recent rapid radiation. Climatic changes, morphological innovations, range expansion and geographical heterogeneity may all contribute to the diversification in Sinopotamon. This study contributes to our knowledge on diversification of freshwater benthic macro-invertebrates in the East Asian inland ecosystem.


Assuntos
Braquiúros/classificação , Água Doce , Animais , Núcleo Celular/genética , China , Variação Genética , Geografia , Funções Verossimilhança , Mitocôndrias/genética , Filogenia , Especificidade da Espécie , Fatores de Tempo
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