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1.
ACS Appl Mater Interfaces ; 12(26): 29302-29315, 2020 Jul 01.
Article in English | MEDLINE | ID: mdl-32525302

ABSTRACT

Selenium-enriched nickel selenide (NiSe-Se) nanotubes supported on highly conductive nickel foam (NiSe-Se@Ni foam) were synthesized using chemical bath deposition with the aid of lithium chloride as a shape-directing agent. The uniformly grown NiSe-Se@Ni foam, with its large number of electroactive sites, facilitated rapid diffusion and charge transport. The NiSe-Se@Ni foam electrode exhibited a superior specific capacitance value of 2447.46 F g-1 at a current density value of 1 A g-1 in 1 M aqueous KOH electrolyte. Furthermore, a high-energy-density pouch-type hybrid supercapacitor (HSC) device was fabricated using the proposed NiSe-Se@Ni foam as the positive electrode, activated carbon on Ni foam as the negative electrode, and a filter paper separator soaked in 1 M KOH electrolyte solution. The HSC delivered a specific capacitance of 84.10 F g-1 at a current density of 4 mA cm-2 with an energy density of 29.90 W h kg-1 at a power density of 594.46 W kg-1 for an extended operating voltage window of 1.6 V. In addition, the HSC exhibited excellent cycling stability with a capacitance retention of 95.09% after 10,000 cycles, highlighting its excellent potential for use in the hands-on applications. The real-life practicality of the HSC was tested by using it to power a red light-emitting diode.

2.
Cancer Lett ; 419: 222-232, 2018 04 10.
Article in English | MEDLINE | ID: mdl-29355658

ABSTRACT

Autophagy is a conserved catabolic process involving large protein degradation by a ubiquitous autophagosomic signaling pathway, which is essential for cellular homeostasis. It is triggered by environmental factors such as stress, lack of nutrients, inflammation, and eliminating intracellular pathogens. Although the mechanisms underlying autophagy are still unclear, increasing evidence illuminates the magnitude of autophagy in a wide range of physiological processes and human diseases. Simultaneously, research community has focused on the triggering of autophagy by the internalization of engineered nanomaterials, which indicates a new line of revolution in cancer cure. However, most studies on nanoparticle-induced autophagy focus on brain, breast, and cervical cancers; limited reports are available on gastrointestinal (GI) cancers. Therefore, the aim of this mini review is to discuss in detail the role of autophagy in GI malignancy and the status of research on nanoparticle-induced autophagy.


Subject(s)
Antineoplastic Agents/administration & dosage , Autophagy/drug effects , Drug Delivery Systems/methods , Gastrointestinal Neoplasms/drug therapy , Nanostructures/administration & dosage , Animals , Antineoplastic Agents/chemistry , Apoptosis/drug effects , Gastrointestinal Neoplasms/pathology , Humans , Nanostructures/chemistry , Signal Transduction/drug effects
3.
Chem Commun (Camb) ; 54(7): 747-750, 2018 Jan 18.
Article in English | MEDLINE | ID: mdl-29308475

ABSTRACT

We report a facile and large-scale synthesis of size-tunable and nontoxic mesoporous silica-coated Gd2O3:Eu3+ (Gd@mSi) core-shell nanostructures using a TPAOH assisted modified UHP technique. The role of TPAOH in controlling the particle size was evaluated. The potentiality of these Gd@mSi core-shell nanoparticles before and after folic acid conjugation was established by in vitro fluorescence microscopy of the U2OS cell lines for cancer imaging and therapy.


Subject(s)
Europium/chemistry , Gadolinium/chemistry , Hydroxides/chemistry , Microscopy, Fluorescence , Nanostructures/chemistry , Quaternary Ammonium Compounds/chemistry , Biomedical Research/methods , Cell Line, Tumor , Humans , Particle Size , Porosity , Silicon Dioxide/chemistry , Surface Properties
4.
Chem Commun (Camb) ; 51(68): 13248-59, 2015 Sep 04.
Article in English | MEDLINE | ID: mdl-26234539

ABSTRACT

Although much progress has been made in treating cancers, cancer death rates in and around the United States are still high. Current treatments are either ineffective against some cancers or detrimental to patients, which decreases their quality of life. The use of nanotechnology in cancer therapy can potentially increase patient survival, reduce side effects, and reduce mortality rates because nanoparticles (NPs) have the potential to target only tumors and bypass healthy cells. NPs possess many features, including size, shape, charge, and composition, which allow them to carry chemotherapeutics to cancer cells. NPs can also be used in radiotherapy as radiosensitizers and in imaging as contrast agents. Many studies have performed in vitro and/or in vivo experiments on these particles in human and animal cell lines. This review discusses recent studies on different NPs and their potential use in cancer therapy.


Subject(s)
Antineoplastic Agents/therapeutic use , Nanoparticles/therapeutic use , Dendrimers/therapeutic use , Gold , Humans , Liposomes/therapeutic use , Magnetite Nanoparticles/therapeutic use , Micelles , Nanotubes, Carbon , Quantum Dots/therapeutic use , Silicon Dioxide/therapeutic use
5.
Sci Rep ; 5: 10296, 2015 May 20.
Article in English | MEDLINE | ID: mdl-25993044

ABSTRACT

White light-emitting diode (WLED) products currently available on the market are based on the blue LED combined with yellow phosphor approach. However, these WLEDs are still insufficient for general illumination and flat panel display (FPD) applications because of their low color-rendering index (CRI < 75) and high correlated color temperature (CCT = 6000 K). Although near-ultraviolet (UV) LED chips provide more efficient excitation than blue chips, YAG:Ce(3+) phosphors have very weak excitation in the near-UV spectral region. Hence, there is an increasing demand for novel yellow phosphor materials with excitation in the near-UV region. In this work, we report novel self-activated yellow Ca(5)Zn(3.92)In(0.08)(V(0.99)Ta(0.01)O(4))(6) (CZIVT) phosphors that efficiently convert near-UV excitation light into yellow luminescence. The crystal structure and lattice parameters of these CZIVT phosphors are elucidated through Rietveld refinement. Through doping with In(3+) and Ta(5+) ions, the emission intensity is enhanced in the red region, and the Stokes shift is controlled to obtain good color rendition. When a near-UV LED chip is coated with a combination of CZIVT and commercial blue Ba(0.9)Eu(0.1)MgAl(10)O(17) phosphors, a pleasant WLED with a high CRI of 82.51 and a low CCT of 5231 K, which are essential for indoor illumination and FPDs, is achieved.

6.
Dalton Trans ; 44(4): 1790-9, 2015 Jan 28.
Article in English | MEDLINE | ID: mdl-25474240

ABSTRACT

Red color-emitting CaGd2ZnO5:Eu(3+) (CGZO:Eu(3+)) nanophosphors were synthesized by a facile sol-gel process. The structural and luminescent properties of these phosphors were investigated as a function of annealing temperature and Eu(3+) ion concentration. The orthorhombic phase was confirmed at different annealing temperatures, showing an irregular morphology within the nanoscale range. Photoluminescence (PL) excitation spectra of CGZO:Eu(3+) showed host absorption band (HAB), charge transfer band (CTB), and intense f-f transitions of Eu(3+) in the violet and blue wavelength regions. The CTB intensity increased and the HAB intensity decreased with increasing annealing temperature or Eu(3+) ion concentration. The CGZO:Eu(3+) exhibited a strong absorption in the blue region as compared to the CTB and had a superior property compared to available commercial phosphors. This feature facilitates the fabrication of high color rendering index white light-emitting diodes for display systems. In PL spectra, an intense red emission was observed due to the hypersensitive (5)D0→(7)F2 transition with good asymmetry ratio and chromaticity coordinates. Optimized annealing temperature and concentration of Eu(3+) ions were observed for CGZO host lattice based on the 466 nm excitation wavelength. The cathodoluminescent properties were also similar to the PL results.


Subject(s)
Calcium/chemistry , Europium/chemistry , Gadolinium/chemistry , Nanostructures/chemistry , Zinc Oxide/chemistry , Drug Stability , Lighting , Luminescence , Microscopy, Electron, Scanning , Nanostructures/ultrastructure , Optics and Photonics , Temperature , X-Ray Diffraction
7.
Phys Chem Chem Phys ; 16(34): 18124-40, 2014 Sep 14.
Article in English | MEDLINE | ID: mdl-25052006

ABSTRACT

Trivalent lanthanide (Eu(3+), Tb(3+) and Dy(3+)) ions activated tunable color emitting BaGd2O4 (BG) phosphors were synthesized by a facile Pechini-type sol-gel process. The X-ray diffraction pattern confirmed the orthorhombic phase after annealing at 1300 °C for 5 h. Morphological studies were performed based on the analysis of transmission electron microscopy images, which showed needle type nanorods. The BG phosphor exhibited good photoluminescence (PL) properties in the respective regions when doped with Eu(3+), Tb(3+) and Dy(3+) ions. The Eu(3+) co-activated BG:Tb(3+) phosphor yielded tunable emissions including tri-band established white light emission based on the co-activator concentration and excitation wavelength. The energy transfer from Tb(3+) to Eu(3+) ions was controlled by selecting a suitable excitation wavelength and the decay measurements were carried out for analyzing the energy transfer efficiency. The cathodoluminescence properties of these phosphors were almost similar to PL properties when doped with individual Eu(3+), Tb(3+), and Dy(3+) ions, but were different when co-doped with Eu(3+)/Tb(3+) or Eu(3+)/Dy(3+) ions. In the case of Eu(3+)/Tb(3+) doped samples, the energy transfer process occurred unlike the PL channel. The calculated Commission International de l'Eclairage chromaticity coordinates of individual ion doped BG phosphors confirmed red, green, and white emissions and for co-doped samples they showed tunable emission.

8.
Dalton Trans ; 43(25): 9766-76, 2014 Jul 07.
Article in English | MEDLINE | ID: mdl-24846293

ABSTRACT

Tm(3+), Er(3+), Tm(3+)/Er(3+), Tm(3+)/Er(3+)/Eu(3+) single, double and triple activator ion/ions doped nanocrystalline BaGd2O4 (BG) phosphors were prepared by a Pechini type sol-gel process. After annealing at 1300 °C, X-ray diffraction patterns confirmed their orthorhombic structure. Field-emission transmission electron microscope images of the BG sample indicated a nanoneedle-type morphology. Photoluminescence (PL) and cathodoluminescence (CL) measurements were utilized to establish the emission properties of rare-earth ions doped nanocrystalline BG host lattice. Under near-ultraviolet (NUV) excitations, BG:Tm(3+) and BG:Er(3+) exhibited their characteristic emissions in the blue and green regions, respectively, while BG:Tm(3+)/Er(3+) and BG:Tm(3+)/Er(3+)/Eu(3+) showed cyan and white light emissions, respectively, when doped with appropriate amounts of activator ions. In the PL, the cross-relaxation process is dominant rather than the energy transfer process. Due to the different mechanism from PL, the CL spectra showed different emission features of BG:Tm(3+)/Er(3+)/Eu(3+) phosphor. The CL spectra of BG:Tm(3+) and BG:Er(3+) established the high purity blue and green emissions, respectively. From the PL and CL investigations, the white-light emission was realized from the single-phase BG:Tm(3+)/Er(3+)/Eu(3+) phosphor under NUV and low voltage electron beam excitations.

9.
Dalton Trans ; 43(8): 3330-8, 2014 Feb 28.
Article in English | MEDLINE | ID: mdl-24366050

ABSTRACT

Mesoporous particles are emerging as multifunctional biomaterials for imaging and drug delivery in several disease models, including cancer. We developed PEGylated α-Gd2(MoO4)3 marigold flower-like mesoporous particles for the purpose of drug delivery and, more specifically, evaluated their ability to deliver curcumin. The obtained mesoporous particles significantly conjugated the curcumin particles on their surfaces by inducing the formation of curcumin nanoparticles. In vitro studies of the PEGylated mesoporous particles filled with curcumin demonstrated that these particles could considerably facilitate the continuous and sustained release of curcumin into the cytoplasm and nucleus. As a result, the intracellular release of curcumin can inhibit proliferation in two human pancreatic cancer cell lines: MIA PaCa-2 and PANC-1. Additionally, the particles showed the increased inhibition of pIKKα, pIKKα/ß and NF-κB-DNA binding activity as compared to pure curcumin. The curcumin conjugated mesoporous particles are concentrated in the cytoplasm and nucleus of the treated cancer cell lines. Consequently, these mesoporous particles are an effective method for drug delivery that can cross the biological barriers of the body targeting the cellular nucleoplasm.


Subject(s)
Coordination Complexes/chemistry , Curcumin/chemistry , Drug Carriers/chemistry , Gadolinium/chemistry , Polyethylene Glycols/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Coordination Complexes/chemical synthesis , Curcumin/toxicity , Humans , Metal Nanoparticles/chemistry , Metal Nanoparticles/ultrastructure , Microscopy, Confocal , Pancreatic Neoplasms/metabolism , Pancreatic Neoplasms/pathology , Particle Size , Porosity
10.
Dalton Trans ; 42(32): 11400-10, 2013 Aug 28.
Article in English | MEDLINE | ID: mdl-23817306

ABSTRACT

Trivalent rare-earth (RE(3+) = Eu(3+), Tb(3+), Dy(3+), and Sm(3+)) ions activated Gd2O(CO3)2·H2O chrysanthemum-like flowers are prepared by a modified urea-based homogeneous precipitation via a template free hydrothermal synthesis route. Subsequently, Gd2O3 monodispersed spheres were obtained after calcining at 750 °C. The growth mechanism of the Gd2O(CO3)2·H2O:RE(3+) chrysanthemum-like morphology (homogeneous precipitation) and their transformation to monodispersed spheres (heterogeneous nucleation) are established by taking scanning electron microscope and transmission electron microscope images of the intermediate products. The thermogravimetric analysis, Fourier transform infrared analyses confirmed the decomposition of CO2 and OH groups, and the corresponding XRD patterns exhibited the Gd2O(CO3)2·H2O and cubic Gd2O3 phases. The photoluminescence measurements are used to explore the emission behavior of different RE(3+) ions activated Gd2O3 spheres. The Gd2O3:Eu(3+) shows gorgeous red emission with high purity red color as compared to the commercial Y2O3:Eu(3+) phosphors. Gd2O3:Tb(3+), Gd2O3:Dy(3+) and Gd2O3:Sm(3+) exhibit green, yellow and rich orange emissions, respectively. The Tb(3+)/Eu(3+) co-doped sample shows warm white light by controlling the energy transfer. At minimal parameters, the cathodoluminescence intensity of Gd2O3:Eu(3+) is beyond the experimental limit for 5 kV of accelerating voltage. The CIE chromaticity coordinates were also calculated from the PL and CL spectra of RE(3+) ions to establish their color richness.


Subject(s)
Gadolinium/chemistry , Luminescent Measurements , Nanostructures/chemistry , Rhenium/chemistry , Chemistry Techniques, Synthetic , Temperature , Urea/chemistry
11.
Phys Chem Chem Phys ; 14(32): 11296-307, 2012 Aug 28.
Article in English | MEDLINE | ID: mdl-22782022

ABSTRACT

Trivalent rare-earth (RE) ions (Eu(3+), Tb(3+) and Sm(3+)) activated multicolor emitting SrY(2)O(4) phosphors were synthesized by a sol-gel process. The structural and morphological studies were performed by the measurements of X-ray diffraction profiles and scanning electron microscope (SEM) images. The pure phase of SrY(2)O(4) appeared after annealing at 1300 °C and the doping of RE ions did not show any effect on the structural properties. From the SEM images, the closely packed particles were observed due to the roughness of each particle tip. The photoluminescence (PL) analysis of individual RE ions activated SrY(2)O(4) phosphors exhibits excellent emission properties in their respective regions. The Eu(3+) co-activated SrY(2)O(4):Tb(3+) phosphor creates different emissions by controlling the energy transfer from Tb(3+) to Eu(3+) ions. Based on the excitation wavelengths, multiple (green, orange and white) emissions were obtained by Sm(3+) ions co-activated with SrY(2)O(4):Tb(3+) phosphors. The decay measurements were carried out for analyzing the energy transfer efficiency and the possible ways of energy transfer from donor to acceptor. The cathodoluminescence properties of these phosphors show similar behavior as PL properties except the energy transfer process. The obtained results indicated that the energy transfer process was quite opposite to the PL properties. The calculated CIE chromaticity coordinates of RE ions activated SrY(2)O(4) phosphors confirmed the red, green, orange and white emissions.

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