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1.
Small ; : e2311217, 2024 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-38396321

RESUMEN

Amidst the escalating quest for clean energy, the hydrogen evolution reaction (HER) in acidic conditions has taken center stage, catalyzing the search for advanced electrocatalysts. The efficacy of these materials is predominantly dictated by the active site density on their surfaces. The propensity is leveraged for monolayer architectures to introduce defects, enhancing surface area, and increasing active sites. Doping enhances defects and fine-tunes catalyst activity. In this vein, defect-enriched monolayer nanosheets doped with nickel and a trace amount of ruthenium in VS2 (SL-Ni-Ru-VS2 ) are engineered and characterized. Evaluation in 0.5 m H2 SO4 solution unveils that the catalyst achieves overpotentials as low as 20 and 41 mV at current densities of -10 and -100 mA cm⁻2 . Impressively, the catalyst maintains a mass activity of 13.08 A mg⁻¹Ru , even with minimal Ru incorporation, indicating exceptional catalytic efficiency. This monolayer catalyst sustains its high activity at lower overpotentials, demonstrating its practical applicability. The comprehensive analysis, which combines experimental data and computational simulations, indicates that the co-doping of Ni and Ru enhances the electrocatalytic properties of VS2 . This research offers a strategic framework for crafting cutting-edge electrocatalysts specifically designed for enhanced performance in the HER.

2.
Angew Chem Int Ed Engl ; 63(15): e202400582, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38308672

RESUMEN

Large-scale deployment of proton exchange membranes water electrolysis (PEM-WE) requires a substantial reduction in usage of platinum group metals (PGMs) as indispensable electrocatalyst for cathodic hydrogen evolution reaction (HER). Ultra-fine PGMs nanocatalysts possess abundant catalytic sites at lower loading, but usually exhibit reduced stability in long-term operations under corrosive acidic environments. Here we report grafting the ultra-fine PtRu crystalline nanoalloys with PtxRuySez "amorphous skin" (c-PtRu@a-PtxRuySez) by in situ atomic layer selenation to simultaneously improve catalytic activity and stability. We found that the c-PtRu@a-PtxRuySez-1 with ~0.6 nm thickness amorphous skin achieved an ultra-high mass activity of 26.7 A mg-1 Pt+Ru at -0.07 V as well as a state-of-the-art durability maintained for at least 1000 h at -10 mA cm-2 and 550 h at -100 mA⋅cm-2 for acid HER. Experimental and theoretical investigations suggested that the amorphous skin not only improved the electrochemical accessibility of the catalyst surface and increasing the intrinsic activity of the catalytic sites, but also mitigated the dissolution/diffusion of the active species, thus resulting in improved catalytic activity and stability under acidic electrolyte. This work demonstrates a direction of designing ultra-fine PGMs electrocatalysts both with high utilization and robust durability, offers an in situ "amorphous skin" engineering strategy.

3.
J Nanosci Nanotechnol ; 14(7): 5542-6, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24758063

RESUMEN

Hexagonal BN crystals have been synthesized from a facile one-step solid state reaction route by sodium tetraphenylborate, hydrazine, zinc powder and sulphur powder as the reactants. The SEM and TEM results showed the BN crystals had the morphology of one-dimensional rod-like shape and with diameters in the range of 100-200 nm and lengths up to several micrometers. Compared with the other reported methods, this route has greatly reduced the reaction temperature. In addition, the growth mechanism of the BN nanorods was discussed in detail. Meanwhile, thermal gravimetric analysis results indicated that the as-prepared BN nanorods have the excellent thermal stability and anti-oxidation properties.

4.
Acta Crystallogr Sect E Struct Rep Online ; 69(Pt 4): m204, 2013 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-23634001

RESUMEN

In the title complex, [Mn(C22H14N3O2)2]·3H2O, the Mn(II) ion is coordinated by two N,N',O-tridentate 2-(2,2':4',2''-terpyridin-6'-yl-κ(2) N (1),N (1'))benzoate ligands in a distorted cis-MnO2N4 octa-hedral geometry. In one ligand, the dihedral angles between the central pyridine ring, the other bonded pyridine ring, the terminal pyridine ring and the benzene ring are 14.3 (15), 18.3 (18) and 43.9 (16)°, respectively. The equivalent angles in the second ligand are 5.8 (18), 6.3 (18), and 47.0 (17)°, respectively. In the crystal, the complex molecules and lattice water molecules are linked by O-H⋯O and O-H⋯N hydrogen bonds, generating a three-dimensional network.

5.
Phytochemistry ; 215: 113833, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37625681

RESUMEN

Chemical investigation of the EtOAc extract of the leaves of Pittosporum lenticellatum led to the isolation of twenty-five previously undescribed eudesmane sesquiterpenoid glycosides, pitlencosides A-Y (1-25); their structures were elucidated by extensive spectroscopic analysis, including 1D and 2D NMR, HR-ESI-MS, ECD spectra, and X-ray crystallographic analysis. Among them, compounds 4, 5, 7, 8, 15 and 16 exhibited significant inhibitory effects on the production of nitric oxide in lipopolysaccharide-induced BV-2 microglial cells by suppressing the expression of inducible nitric oxide synthase and cyclooxygenase-2, with IC50 values ranging from 7.95 to 25.88 µM, which showed stereo-chemical and substituent dependents. Western blot analysis and molecular docking simulation confirmed the anti-inflammatory activity of compounds 4, 5, 7, 8, 15 and 16.


Asunto(s)
Sesquiterpenos de Eudesmano , Sesquiterpenos , Estructura Molecular , Simulación del Acoplamiento Molecular , Sesquiterpenos de Eudesmano/farmacología , Sesquiterpenos de Eudesmano/química , Espectroscopía de Resonancia Magnética , Sesquiterpenos/química , Óxido Nítrico , Glicósidos/farmacología
6.
Pest Manag Sci ; 79(10): 3471-3485, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37139845

RESUMEN

BACKGROUND: Plants from the genus Pittosporum are traditionally used as antibacterial, antifungal and antiviral agents. A bioassay evaluation of the extract of Pittosporum subulisepalum revealed antibacterial activity. This study focused on the discovery of the antibacterial metabolism in P. subulisepalum, as well as the modes of action of its active components. RESULTS: A chemical investigation of an ethyl acetate (EtOAc) extract of the aerial parts of P. subulisepalum led to the isolation of 12 previously undescribed eudesmane sesquiterpenoid glycoside esters (ESGEs), pitsubcosides A-L (1-12). Their structures were elucidated by extensive spectroscopic analysis, including one- and two-dimensional NMR, high-resolution electrospray ionization mass spectrometry, electronic circular dichroism spectra and single-crystal X-ray crystallography analysis or by comparing with authentic samples. The new ESGEs were characterized by their highly esterified glycoside moieties. Among them, compounds 1-3, 5 and 8 showed a moderate inhibitory effect against Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Bacillus cereus, Bacillus subtilis, Pseudomonas syringae pv. actinidiae (Psa) and Erwinia carotovora with minimum inhibitory concentrations (MICs) ranging from 3.13 to 100 µm. Among them, compounds 3 and 5 showed remarkable antibacterial activity against S. aureus and Psa with MIC values of 6.25 and 3.13 µm, respectively. Live bacterial mass and the biofilms of S. aureus and Psa were quantified using methyl tetrazolium and crystal violet assays. Fluorescence microscopy and scanning electron microscopy experiments revealed an antibacterial mechanism of cell membrane architectural disruption. CONCLUSION: The results suggest that ESGEs possess great potential for the development of antibacterial agents to control plant pathogens. © 2023 Society of Chemical Industry.


Asunto(s)
Glicósidos Cardíacos , Staphylococcus aureus Resistente a Meticilina , Sesquiterpenos de Eudesmano , Sesquiterpenos , Staphylococcus aureus , Glicósidos/farmacología , Extractos Vegetales/farmacología , Antibacterianos/farmacología , Antibacterianos/química , Pruebas de Sensibilidad Microbiana , Glicósidos Cardíacos/farmacología , Sesquiterpenos/farmacología , Sesquiterpenos de Eudesmano/farmacología
7.
Sci Rep ; 12(1): 20205, 2022 11 23.
Artículo en Inglés | MEDLINE | ID: mdl-36418371

RESUMEN

With continuous population growth and farmland decrease, the food security is seriously threatened. Farmland reclamation has been used as a means of raising the agricultural productivity and improving the ecological environment. However, the lack of reclaimed soil represents a serious problem. To verify the feasibility and effect of using large amounts of iron tailings to construct farmland, ten treatments (T1-T10) were designed to represent different soil profiles of regional normal farmland and constructed profiles using iron tailings. All treatments involving an iron tailings layer below topsoil exhibited higher soil water contents. The field capacity under T3 (20-cm iron tailings layer below cinnamon soil (b)) was 19.20% higher than that under T7 (20-cm red clay layer below cinnamon soil (b)), and the field capacity under T5 (20-cm iron tailings layer below cinnamon soil (a)) was 2.26% higher than that under T9 (20-cm red clay layer below cinnamon soil (a)). The soil water contents under T3 and T5 were almost the same as those under T7 and T9, respectively. The water-holding capacity of the 30-cm iron tailings layer (T6) was better than that of the 20-cm iron tailings layer (T2). Additionally, none of the treatments caused salt injury to maize. The maize height and stem thickness under the treatments employing iron tailings layers below topsoil were significantly greater than those in normal farmland; the maize height and stem thickness under T3 were 136.82% and 32.02% greater, respectively, than those under T7, and the values under T5 were 9.13% and 9.56% greater, respectively, than those under T9. The maize yields matched or even surpassed those in normal farmland, namely, the maize yield under T5 was equal to that under T9, and the maize yield under T3 was 12.69% higher than that under T7. In general, the application of an iron tailings layer below topsoil to construct farmland is a feasible and environmentally friendly way to realize sustainable farmland utilization and is beneficial to soil quality and crop yield improvement. Collectively, these results provide insight into the efficient utilization of iron tailings and environmental protection.


Asunto(s)
Hierro , Suelo , Granjas , Arcilla , Zea mays , Agua
8.
J Biomed Nanotechnol ; 18(2): 352-368, 2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-35484752

RESUMEN

The construction of high-efficiency tumor theranostic platform will be of great interest in the treatment of cancer patients; however, significant challenges are associated with developing such a platform. In this study, we developed high-efficiency nanotheranostic agent based on ferroferric oxide, manganese dioxide, hyaluronic acid and doxorubicin (FMDH-D NPs) for dual targeting and imaging guided synergetic photothermal-enhanced chemodynamic/chemotherapy for cancer, which improved the specific uptake of drugs at tumor site by the dual action of CD44 ligand hyaluronic acid and magnetic nanoparticles guided by magnetic force. Under the acidic microenvironment of cancer cells, FMDH-D could be decomposed into Mn2+ and Fe2+ to generate •OH radicals by triggering a Fenton-like reaction and responsively releasing doxorubicin to kill cancer cells. Meanwhile, alleviating tumor hypoxia improved the efficacy of chemotherapy in tumors. The photothermal properties of FMDH generated high temperatures, which further accelerated the generation of reactive oxygen species, and enhanced effects of chemodynamic therapy. Furthermore, FMDH-D NPs proved to be excellent T1/T2-weighted magnetic resonance imaging contrast agents for monitoring the tumor location. These results confirmed the considerable potential of FMDH-D NPs in a highly efficient synergistic therapy platform for cancer treatment.


Asunto(s)
Compuestos de Manganeso , Neoplasias , Doxorrubicina/farmacología , Humanos , Ácido Hialurónico , Imagen por Resonancia Magnética , Compuestos de Manganeso/farmacología , Neoplasias/diagnóstico por imagen , Neoplasias/tratamiento farmacológico , Óxidos , Microambiente Tumoral
9.
Front Bioeng Biotechnol ; 10: 1005520, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36177188

RESUMEN

The combination of photothermal therapy (PTT) and immune tumor therapy has emerged as a promising avenue for cancer treatment. However, the insufficient immune response caused by inefficient immunogenic cell death (ICD) inducers and thermal resistance, immunosuppression, and immune escape resulting from the hypoxic microenvironment of solid tumors severely limit its efficacy. Herein, we report an ultrasound and laser-promoted dual-gas nano-generator (calcium carbonate-polydopamine-manganese oxide nanoparticles, CPM NPs) for enhanced photothermal/immune tumor therapy through reprogramming tumor hypoxic microenvironment. In this system, CPM NPs undergo reactive decomposition in a moderately acidic tumor, resulting in the generation of calcium, manganese ions, carbon dioxide (CO2), and oxygen (O2). Calcium and manganese ions act as adjuvants that trigger an immune response. The cancer cell membrane rupture caused by sudden burst of bubbles (CO2 and O2) under ultrasound stimulation and the photothermal properties of PDA also contributed to the ICD effect. The generation of O2 alleviates tumor hypoxia and thus reduces hypoxia-induced heat resistance and immunosuppressive effects, thereby improving the therapeutic efficacy of combination PTT and immune therapy. The present study provides a novel approach for the fabrication of a safe and effective tumor treatment platform for future clinical applications.

10.
Dalton Trans ; 47(4): 1202-1213, 2018 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-29297915

RESUMEN

Hydrothermal reactions of aromatic terphenyl-4,2'',5'',4'-tetracarboxylic acid (H4tta) and transitional metal cations in the presence of two flexible N-donor ancillary ligands afforded four novel coordination polymers, namely, {[Zn(tta)0.5(m-bimb)]·H2O}n (1), [Ni2(tta)(m-bimb)2(H2O)]n (2), [Ni(H2tta)(o-bimb)·H2O]n (3), and [Cd(tta)0.5(o-bimb)]n (4), from solvothermal reactions in the presence of bis(imidazole) bridging linkers (m-bimb = 1,3-bis(imidazol-1-ylmethyl)benzene, and o-bimb = 1,2-bis(imidazol-1-ylmethyl)benzene). Their structures were determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses (EA), powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. Compound 1 displayed a 2-fold 3D → 3D parallel entangled (4,4)-connected bbf net with the point symbol of (64·82)(66)2. Compound 2 featured a predocumented 3D (4,8)-connected (32·53·6)(34·44·59·611) net. Compound 3 exhibited a 2D 4-connected sql sheet with the point symbol of (44·62), and compound 4 showed a 2D 4-connected (32·62·72) kgm sheet. To our delight, fluorescence measurements showed that compound 1 could selectively and sensitively detect Cr3+ cations and nitrobenzene derivatives (nitrobenzene (NB), p-nitrotoluene (PNT), and p-nitroaniline (PNA)), which suggested that CPs of 1 was a promising bifunctional luminescence sensor material that could sense metal ions and small organic molecules. Moreover, 1 showed excellent photocatalytic activity.

11.
J Nanosci Nanotechnol ; 7(12): 4567-70, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18283845

RESUMEN

Ultra-long (several millimeters) tin dioxide SnO2 nanobelts were prepared by chemical vapor deposition at 850 degrees C. The X-ray powder diffraction (XRD) indicated that the as-prepared sample is tetragonal phase SnO2; field emission scanning electron microscopy (FESEM) reveals the as-prepared SnO2 is uniform nanobelts; transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) studies show the nanobelts is monocrystalline with width of hundreds of nanometers and growth along [101] crystal direction; X-ray energy-dispersive spectrometer (EDS) and photoluminescence (PL) spectrum were used to detail its composition and optical properties. The possible formation mechanism of these ultra-long nanobelts was also proposed on the basis of experiments.

12.
Medicine (Baltimore) ; 95(37): e4897, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27631263

RESUMEN

BACKGROUND: Oncocytic carcinoma (OC) arising in the submandibular gland is an unusual malignant neoplasm, with <20 cases previously reported. The cancer is characterized by numerous morphologically abnormal mitochondria present in the cytoplasm and marked cellular pleomorphism. At its most severe, the tumor may invade into the surrounding tissues, including intravascular, lymphatic, or perineural invasion, and lead to regional nodal or distant metastasis. METHODS: The current study describes a novel OC case in a 46-year-old male, the youngest case of the review. The patient presented with a 5-month history of an intermittently painful mass. RESULTS: Following magnetic resonance imaging, excisional biopsy, hematoxylin-eosin staining, phosphotungstic acid-hematoxylin staining, and immunohistochemical examination, an OC of the submandibular gland was diagnosed. CONCLUSION: The current study summarizes the pathogenesis, diagnosis, therapeutics, and the prognosis of OC. The literature review regarding this rare disease is also presented to emphasize the lack of specific markers of OC and the risk of cervical lymph metastasis.


Asunto(s)
Carcinoma/patología , Células Oxífilas , Neoplasias de la Glándula Submandibular/patología , Glándula Submandibular/patología , Adulto , Humanos , Masculino
13.
Dalton Trans ; 44(5): 2380-9, 2015 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-25534253

RESUMEN

Four new coordination polymers, namely [Co(H2O2abtc)(bibp)]n (), {[Mn1.5(Oabtc)(H2O)2]·(H2bmib)0.5·H2O}n (), {[Cd1.5(O2abtc)]·(H2bmib)0.5·2H2O}n (), and {[Cd(nip)(bibp)]·0.5H2O}n (),were constructed under solvothermal conditions in the presence of two bis(imidazole) bridging linkers (bimb = 1,4-bis(2-methylimidazol-1-ylmethyl)benzene, bibp = 4,4'-bis(imidazol-1-yl)biphenyl). The unstable azo ligand of 3,3',5,5'-azobenzenetetracarboxylic acid (H4abtc) could be oxidized and resulted in three oxidized derivatives of H4Oabtc (one N atom was oxidized), H4O2abtc (two N atoms were oxidized), and H2nip (one H4abtc was oxidized to two 5-nitroisophthalic acids). Their structures were determined by single-crystal X-ray diffraction and further characterized by elemental analyses, IR spectroscopy, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analysis. Complex exhibited an interestingly 2D + 2D → 3D parallel entangled network based on 4-connected (4(4)·6(2))-sql sheets. Complex was found to be a {Mn3(COO)6} trinuclear SBU based 2D (3,6)-connected (4(3))2(4(6)·6(6)·8(3))-kgd sheet. While complex displays a {Cd3(COO)8} trinuclear SBUs based 3D (4,8)-connected (4(6))2(4(12)·6(12)·8(4))-flu network. Complex can be regard as a {Cd2(COO)2} binuclear SBUs based 6-connected (4(4)·6(11))-6T8 framework. In addition, the magnetic property of complexes , and the luminescence properties of complexes , were investigated.

14.
Nanoscale Res Lett ; 4(6): 558-64, 2009 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-20596475

RESUMEN

One-dimensional (1D) CdS@ZnS core-shell nanocomposites were successfully synthesized via a two-step solvothermal method. Preformed CdS nanowires with a diameter of ca. 45 nm and a length up to several tens of micrometers were coated with a layer of ZnS shell by the reaction of zinc acetate and thiourea at 180 °C for 10 h. It was found that uniform ZnS shell was composed of ZnS nanoparticles with a diameter of ca. 4 nm, which anchored on the nanowires without any surface pretreatment. The 1D CdS@ZnS core-shell nanocomposites were confirmed by XRD, SEM, TEM, HR-TEM, ED, and EDS techniques. The optical properties and photocatalytic activities of the 1D CdS@ZnS core-shell nanocomposites towards methylene blue (MB) and 4-chlorophenol (4CP) under visible light (λ > 420 nm) were separately investigated. The results show that the ZnS shell can effectively passivate the surface electronic states of the CdS cores, which accounts for the enhanced photocatalytic activities of the 1D CdS@ZnS core-shell nanocomposites compared to that of the uncoated CdS nanowires.

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