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1.
Angew Chem Int Ed Engl ; 63(12): e202319815, 2024 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-38299255

RESUMEN

Piezochromic materials that exhibit pressure-dependent luminescence variations are attracting interest with wide potential applications in mechanical sensors, anticounterfeiting and storage devices. Crystalline porous materials (CPMs) have been widely studied in piezochromism for highly tunable luminescence. Nevertheless, reversible and high-contrast emission response with a wide pressure range is still challenging. Herein, the first example of hierarchical porous cage-based πOF (Cage-πOF-1) with spring structure was synthesized by using aromatic chiral cages as building blocks. Its elastic properties evaluated based on the bulk modulus (9.5 GPa) is softer than most reported CPMs and the collapse point (20.0 GPa) significantly exceeds ever reported CPMs. As smart materials, Cage-πOF-1 displays linear pressure-dependent emission and achieves a high-contrast emission difference up to 154 nm. Pressure-responsive limit is up to 16 GPa, outperforming the CPMs reported so far. Dedicated experiments and density functional theory (DFT) calculations illustrate that π-π interactions-dominated controllable structural shrinkage and porous-spring-structure-mediated elasticity is responsible for the outstanding piezofluorochromism.

2.
Angew Chem Int Ed Engl ; 62(47): e202312733, 2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-37819157

RESUMEN

Chiral induction has been an important topic in chemistry, not only for its relevance in understanding the mysterious phenomenon of spontaneous symmetry breaking in nature but also due to its critical implications in medicine and the chiral industry. The induced chirality of fullerenes by host-guest interactions has been rarely reported, mainly attributed to their chiral resistance from high symmetry and challenges in their accessibility. Herein, we report two new pairs of chiral porous aromatic cages (PAC), R-PAC-2, S-PAC-2 (with Br substituents) and R-PAC-3, S-PAC-3 (with CH3 substituents) enantiomers. PAC-2, rather than PAC-3, achieves fullerene encapsulation and selective binding of C70 over C60 in fullerene carbon soot. More significantly, the occurrence of chiral induction between R-PAC-2, S-PAC-2 and fullerenes is confirmed by single-crystal X-ray diffraction and the intense CD signal within the absorption region of fullerenes. DFT calculations reveal the contribution of electrostatic effects originating from face-to-face arene-fullerene interactions dominate C70 selectivity and elucidate the substituent effect on fullerene encapsulation. The disturbance from the differential interactions between fullerene and surrounding chiral cages on the intrinsic highly symmetric electronic structure of fullerene could be the primary reason accounting for the induced chirality of fullerene.

3.
Environ Sci Technol ; 56(9): 5775-5785, 2022 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-35465657

RESUMEN

Despite increasing sustainable water purification, current desalination membranes still suffer from insufficient permeability and treatment efficiency, greatly hindering extensive practical applications. In this work, we provide a new membrane design protocol and molecule-level mechanistic understanding of vapor transport for the treatment of hypersaline waters via a membrane distillation process by rationally fabricating more robust metal-based carbon nanotube (CNT) network membranes, featuring a superhydrophobic superporous surface (80.0 ± 2.3% surface porosity). With highly permeable ductile metal hollow fibers as substrates, the construction of a superhydrophobic (water contact angle ∼170°) CNT network layer endows the membranes with not only almost perfect salt rejection (over 99.9%) but a promising water flux (43.6 L·m-2·h-1), which outperforms most existing inorganic distillation membranes. Both experimental and molecular dynamics simulation results indicate that such an enhanced water flux can be ascribed to an ultra-low liquid-solid contact interface (∼3.23%), allowing water vapor to rapidly transport across the membrane structure via a combined mechanism of Knudsen diffusion (more dominant) and viscous flow while efficiently repelling high-salinity feed via forming a Cassie-Baxter state. A more hydrophobic surface is more in favor of not only water desorption from the CNT outer surface but superfast and frictionless water vapor transport. By constructing a new superhydrophobic triple-phase interface, the conceptional design strategy proposed in this work can be expected to be extended to other membrane material systems as well as more water treatment applications.


Asunto(s)
Nanotubos de Carbono , Purificación del Agua , Destilación , Gases , Membranas , Vapor
4.
Arch Gynecol Obstet ; 306(4): 1161-1169, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35320389

RESUMEN

PURPOSE: High-risk human papillomavirus (HR-HPV)-positive but cytology-negative cervical cancer screening results are not uncommon. This study aimed to investigate colposcopy's accuracy and diagnostic value in patients with cytology-negative HR-HPV-positive screening results. METHODS: This retrospective study included patients with HR-HPV-positive cytology-negative screening results who underwent electronic colposcopy with acetic acid and multi-point cervical biopsy, HPV typing (24 HPV subtypes), and quantitative HPV detection. RESULTS: Among 229 patients, 130 had chronic cervicitis, and 99 had cervical lesions (CIN1, n = 37; CIN2/3, n = 55; invasive carcinoma, n = 7). Using colposcopy as a reference, the cervical cytology false-negative rate was 43.2% (99/229). Colposcopy was more accurate in patients with HR-HPV16/18 or high viral loads. Multivariable analyses showed HPV viral load and childbearing history were the independent factors affecting the accuracy of colposcopy (P < 0.05). CONCLUSION: Colposcopy in HR-HPV-positive cytology-negative patients has a moderate diagnostic accuracy. The type of cervical transformation zone and HPV viral load are independent factors affecting the accuracy of colposcopy-based diagnosis.


Asunto(s)
Infecciones por Papillomavirus , Neoplasias del Cuello Uterino , Colposcopía , Detección Precoz del Cáncer/métodos , Femenino , Papillomavirus Humano 16 , Papillomavirus Humano 18 , Humanos , Papillomaviridae , Embarazo , Estudios Retrospectivos , Neoplasias del Cuello Uterino/patología
5.
Inorg Chem ; 60(10): 7364-7371, 2021 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-33891407

RESUMEN

Photocatalytic carbon dioxide reduction (CO2RR) is considered to be a promising sustainable and clean approach to solve environmental issues. Polyoxometalates (POMs), with advantages in fast, reversible, and stepwise multiple-electron transfer without changing their structures, have been promising catalysts in various redox reactions. However, their performance is often restricted by poor thermal or chemical stability. In this work, two transition-metal-modified vanadoborate clusters, [Co(en)2]6[V12B18O54(OH)6]·17H2O (V12B18-Co) and [Ni(en)2]6[V12B18O54(OH)6]·17H2O (V12B18-Ni), are reported for photocatalytic CO2 reduction. V12B18-Co and V12B18-Ni can preserve their structures to 200 and 250 °C, respectively, and remain stable in polar organic solvents and a wide range of pH solutions. Under visible-light irradiation, CO2 can be converted into syngas and HCOO- with V12B18-Co or V12B18-Ni as catalysts. The total amount of gaseous products and liquid products for V12B18-Co is up to 9.5 and 0.168 mmol g-1 h-1. Comparing with V12B18-Co, the yield of CO for V12B18-Ni declines by 1.8-fold, while that of HCOO- increases by 35%. The AQY of V12B18-Co and V12B18-Ni is 1.1% and 0.93%, respectively. These values are higher than most of the reported POM materials under similar conditions. The density functional theory (DFT) calculations illuminate the active site of CO2RR and the reduction mechanism. This work provides new insights into the design of stable, high-performance, and low-cost photocatalysts for CO2 reduction.

6.
Nanotechnology ; 32(7): 075602, 2021 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-33241790

RESUMEN

The mercury ions in waste water have threatened public health and environmental protection. In this sense, novel materials with outstanding performances for removal of Hg2+ are imperative. Herein, we demonstrate a thiol-functionalized zirconium metal-organic cage (MOC-(SH)2) with excellent dispersion displays ideal properties for Hg2+ capture. MOC-(SH)2 exhibits the ability of removing Hg2+ in aqueous solutions with a capacity of 335.9 mgHg2+/gMOC-(SH)2, which surpasses that of classical Zr-based metal-organic framework Uio-66-(SH)2 by 1.89 folds. The higher loading capacity of MOC-(SH)2 is probably owing to the excellent dispersion of the discrete cage, which makes the accessibility of binding sites (thiol) easier. Additionally, 99.6% of Hg2+ can be effectively captured by MOC-(SH)2 with the concentration decreased from 5 to 0.02 ppm reaching the permissible limit for Hg2+, outperforming the performance of Uio-66-(SH)2. The excellent absorption property of MOC-(SH)2 is also achieved in terms of superior selectivity under the presence of competitive metal ions. Meanwhile, the regenerated MOC-(SH)2 can be reused without apparent loss of Hg2+ loading capacity. UV-vis absorption spectra, IR spectra and emission spectra further verified the strong chemical affinity between Hg2+ and the thiol of MOC-(SH)2. The study lays the groundwork for using Zr-MOCs in the removal of toxic metal ions and environmental sustainability.

7.
BMC Womens Health ; 21(1): 353, 2021 10 08.
Artículo en Inglés | MEDLINE | ID: mdl-34625069

RESUMEN

BACKGROUND: The significance of HPV viral load in the detection of cervical lesions is still controversial. This study analyzed the correlation between the high-risk HPV viral load and different cervical lesion degrees. METHODS: This retrospective study included women positive for high-risk HPV DNA and screened for cervical lesions between 01/2015 and 06/2018. The high-risk HPV DNA load was measured by the second-generation Hybrid Capture technology and classified as low, moderate, and high. Colposcopy and biopsy were performed in all patients. The patients were grouped as normal, cervical intraepithelial neoplasia (CIN) grade 1, CIN grade 2, CIN grade 3, and cervical cancer. Multivariable logistic regression was performed to explore the association between high-risk HPV DNA load and cervical lesions. The odds ratios (ORs) represent the odds for increasing from low to high viral load. RESULTS: Finally, 265 patients were grouped as normal (n = 125), CIN 1 (n = 51), CIN 2 (n = 23), CIN 3 (n = 46), and cervical cancer (n = 20). Among them, 139 (52.5%) had a low viral load, 90 (34.0) had a moderate viral load, and 36 (13.4%) had a high viral load. Taking the normal control group as a reference, a high viral load was an independent factor for CIN 1 (OR = 3.568, 95% CI: 1.164-10.941, P = 0.026), CIN 2 (OR = 6.939, 95% CI: 1.793-26.852, P = 0.005), CIN 3 (OR = 7.052, 95% CI: 2.304-21.586, P = 0.001), and cervical cancer (OR = 8.266, 95% CI: 2.120-32.233, P = 0.002). CONCLUSIONS: Among women who underwent cervical biopsy, higher high-risk HPV viral load in cervical lesions was associated with a higher risk of high-grade cervical lesions.


Asunto(s)
Infecciones por Papillomavirus , Displasia del Cuello del Útero , Neoplasias del Cuello Uterino , Femenino , Humanos , Infecciones por Papillomavirus/complicaciones , Infecciones por Papillomavirus/diagnóstico , Estudios Retrospectivos , Neoplasias del Cuello Uterino/diagnóstico , Carga Viral , Displasia del Cuello del Útero/diagnóstico
8.
Chemistry ; 26(12): 2735-2740, 2020 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-31808202

RESUMEN

At present, the fixation of CO2 always requires it to be extracted from the atmosphere first, which leads to more energy consumption. Thus, direct photoreduction of low-concentration CO2 to useful chemicals (e.g., syngas) under sunlight is significant from an energy-saving and environmentally friendly perspective. Here, the design and fabrication of a [Ru(bpy)3 ]/[Co20 Mo16 P24 ] composite is demonstrated for visible-light-driven syngas production from diluted CO2 (3-20 %) gas with a high yield of approximately 1000 TONs (turnover number of syngas). This activity is an order of magnitude higher than the reported system with [Ru(bpy)3 ]2+ participation. With evidence from ultrafast transient absorption, GC-MS, 1 H NMR spectroscopy and in situ transient photovoltage tests, a clear and fundamental understanding of the highly efficient photoreduction of CO2 by the [Ru(bpy)3 ]/[Co20 Mo16 P24 ] composite is achieved. Making use of the structure and property designable polyoxometalates towards the photo-fixation of CO2 is a conceptually distinct and commercially interesting strategy for making useful chemicals and environmental protection.

9.
Nanotechnology ; 31(25): 255402, 2020 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-32143193

RESUMEN

A system containing polyoxometalate ([Co-POM]2-) and [Ru(bpy)3]2+ as constructed for visible-light-induced CO2 conversion to syngas. In diluted CO2, high efficiency of 56.8 mmol g-1 h-1 in syngas production was gained, exceeding that of reported systems with [Ru(bpy)3]2+ participation in similar conditions. Mechanism studies revealed efficient photo-induced charge separation is achieved in the system and CO2 reduction tends to occur on [Ru(bpy)3]2+.

10.
Nanotechnology ; 31(21): 215605, 2020 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-32018234

RESUMEN

Halide perovskites have been employed as photocatalysts for CO2 photoreduction due to their excellent optical properties and unique electronic structure. However, their photocatalytic performance is relatively poor. Herein, we demonstrate a new strategy with Mn-doped CsPb(Br/Cl)3 mixed-halide perovskites as catalysts to enhance the efficiency of CO2 photoreduction. By tuning the content of Mn, a series of CsPb(Br/Cl)3:Mn perovskites are obtained and show high efficiency in CO2 conversion to CO and CH4. For the optimum catalyst sample, especially, the yields of CO and CH4 reach 1917 µmol g-1 and 82 µmol g-1 which are 14.2 and 1.4 times higher than those of CsPbBr3. This work provides new insights into improving the reactivity of perovskites in CO2 photoreduction.

11.
Environ Sci Technol ; 54(14): 9074-9082, 2020 07 21.
Artículo en Inglés | MEDLINE | ID: mdl-32544323

RESUMEN

Treatment of highly saline wastewaters via conventional technology is a key challenging issue, which calls for efficient desalination membranes featuring high flux and rejection, low fouling, and excellent stability. Herein, we report a high-strength and flexible electro-conductive stainless steel-carbon nanotube (SS-CNT) membrane, exhibiting significantly enhanced anticorrosion and antifouling ability via a microelectrical field-coupling strategy during membrane distillation. The membrane substrates exhibited excellent mechanical strength (244.2 ± 9.8 MPa) and ductility, thereby overcoming the critical bottleneck of brittleness of traditional inorganic membranes. By employing a simple surface activation followed by self-catalyzed chemical vapor deposition, CNT was grown in situ on SS substrates via a tip-growth mechanism to finally form robust superhydrophobic SS-CNT membrane. To address the challenging issues of significant corrosion and fouling, using a negative polarization microelectrical field-coupling strategy, simultaneously enhanced antifouling and anticorrosion performance was realized for treatment of organic high salinity waters while exhibiting stable high flux and rejection via an electrostatic repulsion and electron supply mechanism. This application-oriented rational design protocol can be potentially used to extend toward high performance composite membranes derived from other electro-conductive metal substrates functionally decorated with CNT network and to other applications in water treatment.


Asunto(s)
Nanotubos de Carbono , Purificación del Agua , Interacciones Hidrofóbicas e Hidrofílicas , Membranas Artificiales , Metales
12.
Angew Chem Int Ed Engl ; 59(49): 22034-22038, 2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-32896078

RESUMEN

Systematic design and self-assembly of metal-organic polyhedra with predictable configurations has been a long-standing challenge in crystal engineering. Herein a concave polyoxovanadate cluster, [V6 O6 (OCH3 )9 (SO4 )4 ]5- , which can be generated in situ under specific reaction conditions, is reported. Based on this cluster, a potential trivalent molecular building block, [V6 O6 (OCH3 )9 (SO4 )(CO2 )3 ]2- , can be obtained by the bridging-ligand-substitution strategy and it possesses appropriate angle information for the design of molecular cubes. Utilizing the face-directed assembly of the trivalent molecular building block and a diverse set of tetratopic carboxylate linkers, a series of metal-organic cubes (VMOC-1-VMOC-5) with the same topology but different functionalities and dimensions were designed and constructed. An inclusion study using VMOC-3 shows that they are potential molecular receptors for selective capture of size-matching polycyclic aromatic hydrocarbon guest molecules.

13.
Chemistry ; 25(72): 16617-16624, 2019 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-31631411

RESUMEN

Hybrid materials have obtained well-deserved attention for energy storage devices, because they show high capacitances and high energy densities induced by the synergistic effect between complementary components. Polyoxometalate-based metal-organic frameworks (POMOFs) possess the abundant redox-active sites and ordered structures of polyoxometalates (POMs) and metal-organic frameworks (MOFs), respectively. Here, an asymmetric supercapacitor (ASC) NENU-5/PPy/60//FeMo/C was fabricated in which both its electrodes are prepared from POMOF precursors. A typical POMOF material, NENU-5, was first connected with polypyrrole (PPy) through electrodeposition to form the cathode material NENU-5/PPy. Another representative POMOFs material, PMo12 @MIL-100, was carbonized to obtain the anode material FeMo/C. Cathode NENU-5/PPy exhibited an extraordinary capacitance of 508.62 F g-1 (areal capacitance: 2034.51 mF cm-2 ). In addition, anode FeMo/C shows excellent cyclic stability attributed to its unique structure. Finally, benefiting from the outstanding capacitances and structural merits of the anode and cathode, assembled asymmetric supercapacitor NENU-5/PPy/60//FeMo/C achieves an energy density of 1.12 mWh cm-3 at a power density output of 27.78 mW cm-3 , as well as a notable life of 10 000 cycles with an capacity retention of 80.62 %. Thus, the unique ASC is strongly competitive in high capacitance, long cycle life, and high energy-required energy storage devices.

14.
Chemistry ; 25(1): 379-385, 2019 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-30353588

RESUMEN

As the main component of syngas, reducing CO2 to CO with high selectivity through photocatalysis could provide a sustainable way to alleviate energy shortage issues. Developing a photocatalytic system with low cost and high performance that is environmentally friendly is the ultimate goal towards CO2 photoreduction. Herein, an efficient and economic three-component heterojunction photocatalyst is designed and fabricated for converting CO2 to CO in the absence of organic sacrificial agents. The heterojunction is made of Cu2-x S nanotubes coated with a carbon layer (C-Cu2-x S) and g-C3 N4 . By using the classical MOF material HKUST-1 as a precursor, hollow tubular-like metal sulfides (C-Cu2-x S) with carbon coating were synthesized and further loaded on g-C3 N4 , forming a three-component heterojunction C-Cu2-x S@g-C3 N4 . The carbon coat in C-Cu2-x S@g-C3 N4 acts as an electron reservoir, which facilitates electron-hole pair separation. The optimized C-Cu2-x S@g-C3 N4 acted as a photocatalyst in CO2 reduction with a high reactivity of 1062.6 µmol g-1 and selectivity of 97 %. Compared with bare g-C3 N4 (158.4 µmol g-1 ) and C-Cu2-x S, the reactivity is nearly 7 and 23-fold enhanced and this CO generation rate is higher than most of the reported Cu2 S or g-C3 N4 composites under similar conditions. The prominent activity may result from enhanced light adsorption and effective charge separation. This work might open up an alternative method for the design and fabrication of high-performance and low-cost photocatalysts for efficiently and durably converting CO2 to CO with high selectivity.

15.
Chemistry ; 25(11): 2824-2830, 2019 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-30575148

RESUMEN

Metal-organic polyhedra (MOPs) are promising candidates for many potential applications; however, their use as photocatalysts for hydrogen production has yet to be developed. Herein, the photocatalytic performance of a water-stable Zr-MOP, ZrT-1-NH2 , was evaluated, for the first time, through photocatalytic hydrogen evolution under visible-light irradiation. ZrT-1-NH2 shows clearly enhanced photocatalytic activity (510.42 µmol g-1 h-1 ) for hydrogen production, in comparison with that of other homogeneous crystalline materials. If platinum nanoparticles were introduced into the photocatalytic system, the hydrogen production efficiency of ZrT-1-NH2 could be further improved. For ZrT-1-NH2 , the conspicuous improvement in photocatalysis can be attributed to efficient electron-hole separation, targeted electron transfer, and excellent recombination suppression. Furthermore, ZrT-1-NH2 shows excellent stability during photocatalytic hydrogen evolution over five continuous runs. This work illustrates that MOP-based photocatalysts hold promise for broad applications in the domain of clean energy.

16.
Angew Chem Int Ed Engl ; 58(3): 780-784, 2019 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-30475444

RESUMEN

A rational synthetic strategy to construct two supramolecular isomers based on polyoxovanadate organic polyhedra with tetrahedral symmetries is presented. VMOP-α, a low-temperature product, has an extremely large cell volume (470 842 Å3 ), which is one of the top three for well-defined MOPs. The corner-to-corner packing of tetrahedra leads to a quite low density of 0.174 g cm-3 with 1D channels (ca. 5.4 nm). The effective pore volume is up to 93.6 % of cell volume, nearly the largest found in MOPs. For the high-temperature outcome, VMOP-ß, the cell volume is only 15 513 Å3 . The packing mode of tetrahedra is corner-to-face, giving rise to a high-density architecture (1.324 g cm-3 ; channel 0.8 nm). Supramolecular structural transformation between VMOP-α and VMOP-ß can be reversibly achieved by temperature-induced solvent-mediated transformation. These findings give a good opportunity for understanding 3D supramolecular aggregation and crystal growth based on large molecular tectonics.

17.
Cell Physiol Biochem ; 45(4): 1654-1662, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29486472

RESUMEN

BACKGROUND/AIMS: Ovarian cancer is one of the most common malignancies with a high rate of mortality in women. However, current therapies for ovarian cancer treatment are ineffective. Therefore, novel target identification is an urgent requisite. The present study aimed to investigate the role of microRNA-214 (miR-214) in ovarian cancer. METHODS: The expression of miR-214, ß-catenin, cyclin D1, c-myc, and TCF-1 at the transcriptional level was measured by real-time PCR, while that of ß-catenin, Cyclin D1, and c-Myc at the protein level were detected by western blot. Colony formation assay and transwell assay were used to explore the invasion ability of the cancer cells. Cell cycle was measured by flow cytometry. RESULTS: Real-time PCR showed that miR-214 expression in ovarian cancer cell lines was lower than that in the human normal ovarian epithelial cells, IOSE80. Furthermore, the low expression of miR-214 was correlated with high pathological grade. The rate of colony formation and invasion of miR-214 overexpression in SKOV-3 cells were weaker than that in control cells. Moreover, miR-214 overexpression led to the G0/G1 phase arrest. The expression of ß-catenin, Cyclin D1, and c-Myc was suppressed by the overexpression of miR-214. CONCLUSION: These results suggested that miR-214 may serve as a tumor suppressor of ovarian cancer by targeting the ß-catenin pathway.


Asunto(s)
MicroARNs/metabolismo , Neoplasias Ováricas/patología , beta Catenina/metabolismo , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Ciclina D1/genética , Ciclina D1/metabolismo , Regulación hacia Abajo , Femenino , Puntos de Control de la Fase G1 del Ciclo Celular , Humanos , MicroARNs/genética , Neoplasias Ováricas/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Puntos de Control de la Fase S del Ciclo Celular , Factor 1 de Transcripción de Linfocitos T/genética , Factor 1 de Transcripción de Linfocitos T/metabolismo , Vía de Señalización Wnt , beta Catenina/antagonistas & inhibidores , beta Catenina/genética
18.
Chemistry ; 24(56): 15089-15095, 2018 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-30051935

RESUMEN

Luminescent organogold(III) complex AuIII with highly emissive triplet excited state was encapsulated in two metal-organic frameworks (MOFs) with different pore sizes and structures (MOF1 and ZJU-28). Compared with the AuIII complex in solution, the resultant composites AuIII @MOF1 and AuIII @ZJU-28 exhibit enhanced emission intensity, lifetime, and quantum yield. Under irradiation, AuIII @MOFs are efficient, selective, and recyclable catalysts for light-induced aerobic C-N bond formation. When used as a heterogeneous catalyst for oxidizing secondary amines to the corresponding imines, AuIII @ZJU-28 achieved high TONs of 876-1548, which are about 2.8-3.5 times higher than that of the homogenous AuIII complex. In addition, different selectivities in oxidizing mixed substrates is realized by means of different host MOFs, and thus encapsulating the AuIII complex in an appropriate MOF allowed the desired product to be obtained. Inherent shortcomings of homogeneous catalysts in cyclic use are also overcome by using composite catalysts, and high conversion of the AuIII @ZJU-28 catalyst was still observed after ten cycles.

19.
Nanotechnology ; 29(28): 284003, 2018 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-29648546

RESUMEN

Metal-organic frameworks (MOFs) are well-known porous materials able to adsorb CO2, and their performance in CO2 reduction has attracted much attention from researchers. A classical Co-MOF, Co-ZIF-9, has been proposed as a novel photocatalyst for reducing CO2 into chemical feedstocks. Herein, Co-ZIF-9 with a rod-like structure was obtained through reflux. Ultra-small silver nanoparticles (Ag NPs, smaller than 5 nm) were doped into Co-ZIF-9 by the photodeposition method. With the assistance of a photosensitizer, the resultant composite Ag@Co-ZIF-9 shows catalytic reactivity in converting CO2 into CO under visible light irradiation. Compared with bare Co-ZIF-9, the photocatalytic performance of Ag@Co-ZIF-9 increases by more than twofold (around 28.4 µmol CO) and the selectivity is enhanced by about 20% (22.9 µmol H2) for 0.5 h of irradiation. This demonstrates that Ag NPs doping may provide a possible way to promote the efficiency and selectivity of MOF materials in CO2 photoreduction.

20.
Tumour Biol ; 37(6): 8239-48, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26718213

RESUMEN

Ovarian cancer is one of the most common human malignancies in women. MiR-214 and semaphorin 4D (sema 4D) were found to be abhorrently expressed and involved in the progress of several kinds of malignant cancers. This study is aimed to investigate the cellular role of miR-214 and demonstrate that miR-214 negatively regulated sema 4D in ovarian cancer cells. The data showed that miR-214 expression was consistently lower in ovarian cancer tissues and cells than those in the normal controls. Over-expression of miR-214 in ovarian cancer SKOV-3 cells inhibited cell proliferation and induced apoptosis. It was suggested that miR-214 functioned as the tumor suppressor in ovarian cancer. Bioinformatic analysis indicated that miR-214 possibly regulated sema 4D by binding the sema 4D messenger RNA (mRNA) 3'-untranslated region (UTR). Sema 4D mRNA and protein levels were up-regulated in ovarian cancer tissues and SKOV-3 cells. Up-regulation of miR-214 in SKOV-3 cell line suppressed the sema 4D expression in both protein and nucleic acid levels. While, down-regulation of miR-214 in SKOV-3 cells would increase sema 4D protein and nucleic acid expression levels. The effects of miR-214 up- and down-regulation on luciferase activities of wild-type (WT) sema 4D 3'-UTR were completely removed upon introduction of mutation in 3'-UTR of WT sema 4D. Therefore, the data also demonstrated that sema 4D was the direct target of miR-214 and was negatively regulated by miR-214 in ovarian cancer cells.


Asunto(s)
Antígenos CD/genética , Regulación Neoplásica de la Expresión Génica/fisiología , MicroARNs/genética , Neoplasias Ováricas/genética , Semaforinas/genética , Antígenos CD/metabolismo , Apoptosis/genética , Western Blotting , Línea Celular Tumoral , Proliferación Celular/genética , Regulación hacia Abajo , Femenino , Humanos , Inmunohistoquímica , Neoplasias Ováricas/patología , Reacción en Cadena en Tiempo Real de la Polimerasa , Semaforinas/metabolismo
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