Intense Orange Research Articles

Intense Orange Red Emission from Sm3+-Activated Ca3Al2O6 Phosphor for Display Device Application

Intense Orange Red Emission from Sm3+-Activated Ca3Al2O6 Phosphor for Display Device Application

Judd–Ofelt Intensity Parameters and Optical Properties of Eu/Li Co‐Doped CeO2 Phosphor

AbstractIn this work, the intense orange‐red emission of Eu3+ singly and Eu3+/Li+ co‐doped CeO2 phosphors synthesized by solution combustion using urea as fuel was investigated experimentally and theoretycally. X‐ray diffraction and high‐resolution transmission electron microscope analysis confirmed the formation of a single‐phase CeO2 cubic with high crystallinity. Under 360 nm excitation, the phosphors emitted an intense orange–red region of Eu3+ as a function of Li+ doping content. Significantly, it was enhanced 12/10 times by Li+ co‐doping due to the increased crystallinity of the host lattice. The energy transfer proccesse associated with cross‐relaxation is responsible for decreasing the experimental lifetime of Eu3+. The influence of Li+ doping content on the characterization properties of CeO2:Eu, Li phosphors was further explained using Judd‐Ofelt (J−O) theory, from which branching ratios (βr), transition probability (A), radiative lifetime (τcal), and stimulated cross‐section (σe) emission of the phosphors were estimated. The results indicate that an effectively improved crystallinity by Li+ co‐doped CeO2:Eu can significantly enhance its luminescence intensity, making it suitable for optoelectronic and display applications.

Photoinduced enhancement of intraligand charge-transfer of a crystalline 3,3′-diindolyl(3-pyridyl)methane

The photoexcitation facilitating the efficient charge-transfer in a crystalline solid of 3,3′-diindolyl(3-pyridyl)methane with solvated methanol.

Energy transfer-based color tunability, thermal quenching, and quantum yield of Sm3+/Eu3+ codoped lithium zinc borophosphate glasses

Lithium zinc borophosphate (LZBP) glasses, imbedded with Sm3+, Eu3+, & Sm3+/Eu3+ ions in solely and combinedly were synthesized using melt-quenching technique, and their energy-transfer-dependent photoluminescence (PL)-related characteristics were explored. LZBP: 0.5 % Sm3+ and LZBP: 0.5 % Eu3+ glasses exhibited intense orange and red emissions under 404 and 394 nm excitation wavelengths, respectively. When the Sm3+/Eu3+ codoped glass systems were excited with Sm3+ excitation (404 nm), has lead to a noticeable drop in the emission intensity of Sm3+ peaks at 562 nm (4G5/2 → 6H5/2; yellow), 602 nm (4G5/2 → 6H7/2, orange), and 645 nm (4G5/2 → 6H9/2, red) whereas the emission intensity of Eu3+ peaks at 591 nm (5D0→7F1; orange) and 617 nm (5D0→7F2; red) has enhanced. At the same time, the decay lifetime of singly doped Sm3+ decreased from 1.54 to 0.91 ms, with codoping different concentrations of Eu3+ ions. The decrease in both PL intensity and lifetimes of Sm3+ in the presence of Eu3+ suggests an efficient energy transfer (ET) from Sm3+→Eu3+, which is facilitated by dipole-dipole interaction. The ET from Sm3+→Eu3+ achieved through the channels, Sm3+:4G5/2 + Eu3+:7F1 → Sm3+:6H7/2 + Eu3+:5D0 and Sm3+:4G5/2 + Eu3+:7F2 → Sm3+:6H5/2 + Eu3+:5D1. Furthermore, ET from Sm3+ to Eu3+ is supported by the spectral overlay between Sm3+ emission and Eu3+ absorption, ET parameters (η(Sm3+⟶Eu3+) = 40.91 % and P(Sm3+⟶Eu3+) = 1098.9 S-1). The shift in color coordinated from orange to red, with an increase in Eu3+ doping content in the codoped glasses at 404 nm excitation demonstrates the promising application of the Sm3+/Eu3+ codoped glass system in orange-red light-emitting diodes. LZBP: 0.5 Sm3+/1.0 Eu3+ codoped glass exhibited good thermal stability (Ea = 0.19 eV), depending on temperature-dependent PL properties. The quantum yield (η) for the LZBP glass containing 0.5 Sm3+/1.0 Eu3+ codoped ions is evaluated to be 44.6 %.

A terbium-sensitized Eu3+-activated deep-red-emitting phosphor for plant growth LED application

Traditional Eu3+-activated inorganic phosphors are habitually used for general lighting and display because they generally emit either intense orange (5D0-7F1) or red (5D0-7F2) light whose wavelength is shorter than 630 nm. However, less known nor focused is that Eu3+ at sites with specific symmetry can intensify its 5D0-7F4 transition, enabling Eu3+ itself to emit deep red light (>700 nm) even stronger than the above orange and red ones. Herein, a novel Eu3+-activated phosphor, Ca2TbSn2Al3O12:Eu3+, is developed from the garnet structure. Differing from other Eu3+-activated phosphors, the 5D0-7F4 transition of Eu3+ in the host is dominant and the orange, red and deep red emissions are balanced. Such special features of Eu3+ luminescence mainly meet the need of phytochromes (PFR and PR) in plants. Additionally, bridge style energy transfer from the host composition element Tb3+ to the activator Eu3+ can be observed. It is found the Tb3+-Eu3+ energy transfer here takes through the mechanism of dipole-dipole interaction and the simulation on decay curve of Eu3+ upon Tb3+ excitation, for the first time, confirms the existence of terbium bridge energy transfer. For the Ca2Tb0.60Sn2Al3O12:0.40Eu3+, the energy transfer efficiency is as high as 94.4% and the emission color is totally red. Thermal quenching studies reveal that the emission intensity of the phosphor at 425 K sustains 80% of its initial intensity at room temperature. By fabricating the phosphor with a 380 nm LED chip, a plant-growth LED device can be obtained.

A novel orange-red Sm3+-doped CaSiO3 nanostructured phosphor derived from agro food waste materials for white light applications

Trivalent samarium activated β-Wollastonite (β-CaSiO3:Sm3+) nanostructured phosphor powders have been synthesized by modified sol-gel method at various concentrations (0.0, 0.2, 0.4, 0.6, 0.8 and 1 mol %) employing rice husk ash (RHA) and eggshell (ES) as the precursors for SiO2 and CaO respectively. The powder x-ray diffraction peaks disclose structure of sintered samples as monoclinic structure with space group P1 21/c1. The average crystallite sizes were determined by Debye scherrer's formula in the range of 26–34 nm. The average particle size was 84.5 nm found from TEM images. The photoluminescence excitation (PLE) spectra recorded high intensity peak at 400 nm was owing to 6H5/2 → 4K11/2 transition. The emission (PL) spectra of prepared samples exhibit intense orange–red color emission peak at 602 nm due to 4G5/2→6H7/2 transition. All the prepared samples emission tuned towards white region of the CIE diagram with the increment of Sm3+ content. This new nanostructured phosphor material could be a probable candidate for white light display and solid-state lighting (SSL) applications.

Orange–red fluorescence features of SrAl2O4: Sm3+ phosphors

A series of SrAl2O4: [Formula: see text]Sm[Formula: see text] ([Formula: see text] = 0, 0.1, 0.5, 1.0 and 2.0 mol.%) nanophosphors were synthesized by the conventional solid-state reaction method and characterized. The structural and morphological properties were analyzed through powder X-ray diffraction (PXRD), Fourier transform infrared, Fourier transform Raman, scanning electron microscopy and transmission electron microscopy studies. The fluorescence features were examined through photoluminescence-excitation and emission studies. The investigated phosphor materials show intense orange–red fluorescence at 400 nm excitation. For intense and effective fluorescence, the Sm[Formula: see text] -doping concentration was optimized as 1.0 mol.%. The cross-relaxation mechanism responsible for fluorescence quenching beyond the optimum concentration was discussed. The color perception of emitted fluorescence was analyzed by evaluating Commission International de I’Eclairage (CIE) 1931 coordinates. The experimental results confirmed the candidature of orange–red emitting SrAl2O4: 1.0 Sm[Formula: see text] nanophosphor for various lighting applications.

A Novel Approach to Design Luminomagnetic Pigment Formulated Security Ink for Manifold Protection to Bank Cheques against Counterfeiting

AbstractA new strategy for formulating a high‐security anti‐counterfeiting ink by synthesizing a pigment having both luminescent and magnetic features is demonstrated. The as‐synthesized pigment (Zn0.98Mn0.02S @ Gd1.7Yb0.2Er0.1O3 @ Fe3O4) emits intense orange (580 nm wavelength) and red (660 nm wavelength) color upon excitation with 351 and 980 nm wavelength, respectively. Moreover, the room temperature M–H curve of as‐synthesized pigment shows a typical ferromagnetic behavior. Due to the magnetic behavior of multi‐functional security ink along with dual‐mode luminescence, it can potentially be suitable to use for the printing of bank cheques (logos, magnetic ink character recognition codes), smart tags, etc., where the important information needs to be delicately encrypted and can be authenticated without being getting decoded. The security ink has been also studied using magnetic force microscopy for magnetic behavior and photoluminescence mapping to examine the uniform distribution of emission intensity over the printed pattern. Further, the patterns printed from the synthesized security ink are highly stable against the various bleaching agents and atmospheric conditions like hot, cold, and humid for the investigated period of six months. Hence, the new exceptional outcome of multi‐functional pigment formulated security ink offers a set of new distinctive features against counterfeiting.

Oxidation of diclofenac in the presence of iron(II) octacarboxyphthalocyanine

This paper presents the results of the research on the influence of catalytic activity of iron(II) octacarboxyphthalocyanines (FePcOC) on the transformation of diclofenac (DCF) which is the most popular anti-inflammatory analgesic. Diclofenac poses a serious threat to the natural environment. The paper demonstrates that diclofenac, in the presence a monomeric form of iron octacarboxyphthalocyanine and hydroxyl radicals (HO•) (from H2O2), undergoes a transformation into diclofenac-2,5-iminoquinone (DCF-2,5-IQ), causing distinct changes in the UV–Vis absorption spectrum. In the presence of iron octacarboxyphthalocyanine and H2O2, the previously colourless diclofenac solution becomes intense orange. As a result, a new band at approx. 450 nm appears in the absorption spectrum. HPLC analysis has shown that the concentration of diclofenac decreases with time. TD-DFT calculations using the CAM-B3LYP/6-31+G (d, p) method have been conducted to confirm experimental data concerning the formation of a new band at λmax = 450 nm.

Design and realization of an orange–red phosphor samarium-activated diphosphate Na5Bi1−xSmx(P2O7)2

Recently, rare-earth-activated phosphors have been excessively studied for applications in field of white light-emitting diodes (W-LEDs). In this work, a series of Sm3+-doped Na5Bi(P2O7)2 phosphors have been synthesized via traditional high-temperature solid-state reaction method. The purity and phase structure were verified by powder X-ray diffraction (XRD) analysis. Owing to the 4G5/2→6H7/2 transition of Sm3+, Na5Bi1−xSmx(P2O7)2 phosphors show intense orange–red emission centered at 600 nm under near-UV light (403 nm) excitation. The 4% Sm3+ ion is the optimum doping concentration. The concentration quenching dominant mechanism is the d−d interaction. Moreover, phosphors Na5Bi0.96Sm0.04(P2O7)2 show good thermal stability, restraining 79.4% at 150 °C of that measured at 25 °C. The CIE coordinates of phosphor Na5Bi0.96Sm0.04(P2O7)2 were calculated to be (0.573, 0.414). Therefore, phosphor Na5Bi1−xSmx(P2O7)2 could be potentially used as an orange–red phosphor for W-LEDs.

Waveguide laser potency of samarium doped BaSO4-TeO2-B2O3 glasses: Evaluation of structural and optical qualities

A series of samarium ions (Sm3+) doped barium-sulfur-telluro-borate glasses of composition (70-x)B2O3-15BaSO4-15TeO2-xSm2O3 (x ranged from 0.0 to 2.5 mol%) was prepared by melt-quenching method and examined via diverse analytical tools. Influence of changing Sm3+ doping contents on the structures and optical attributes of the proposed glasses was determined. The XRD pattern of as-quenched samples verified their glassy states. The FTIR spectra displayed the vibrational modes of tellurites and borates functional groups in the corresponding range of 460–850 cm−1 and 700–1650 cm−1. The EDX elemental maps confirmed the homogeneous distribution of the traced elements in the glass matrix. The UV–Vis–NIR absorption spectra of glasses exhibited nine distinct bands compatible with the transition from lower 6H5/2 state to the excited 6P3/2, 4I11/2, 6F11/2, 6F9/2, 6F7/2, 6F5/2, 6F3/2, 6H15/2 and 6F1/2 states of Sm3+. The photoluminescence spectra showed four emission bands allotted to magnetic dipole 4G5/2 → 6H5/2 (moderate green at 562 nm), electric dipole dominated 4G5/2 → 6H7/2 (intense orange at 598 nm), electric dipole 4G5/2 → 6H9/2 (moderate red at 645 nm) and 4G5/2 → 6H11/2 (weak red at 703 nm) transitions in Sm3+, respectively. Glasses containing Sm2O3 contents above 1.0 mol% disclosed luminescence intensity quenching. Evaluated Judd-Ofelt intensity parameters Ω2, Ω4, and Ω6 were discerned to range from 1.48 × 10−20–4.2 × 10−20 cm2, 2.31 × 10−20–4.31 × 10−20 cm2 and 1.26 × 10−20–1.99 × 0−20 cm2 respectively. Furthermore, the lifetime of the samples decreases with increase in Sm3+ contents as unraveled by decay curve analysis. The achieved excellent spectroscopic properties of the proposed glass composition suggested their effectiveness as visible laser for waveguide applications.

Sensory Properties and Consumer Acceptance of Cantaloupe Melon Cultivars.

This research measured the sensory characteristics and consumer acceptance of 15 cultivars of cantaloupe. Eleven trained panelists assessed melons by descriptive analysis. Northern California consumers (n = 171) evaluated the melons for overall, appearance, flavor, and texture liking on the 9-point hedonic scale and the adequacy of ripeness, sweetness, and firmness on a 5-point just-about-right (JAR) scale. Twenty-two sensory attributes differed significantly among the melons. CaldeoDF, Caldeo, Globstar, RML0499, and Caribbean Gold showed higher firmness, crunchiness, and denser textures. Impac presented higher watermelon flavor, bitterness, and sourness. Caldeo, CaldeoDF, Globstar, Magellan, and Sol Real had higher overall intensity, sweetness and oversweet flavor, longer-lasting aftertaste, and salivating mouthfeel. Consumers liked Magellan, Acclaim, and Primo most, and Aphrodite and Impac least, and the harvesting period was not critical to consumer acceptance. Sweet, oversweet flavor, and intense orange and richness of color were drivers of overall liking. Preference clustering identified three groups of consumers with distinct sensory preferences and favorite cultivars. JAR data showed Acclaim, Magellan, Primo, and Saguaro were just right for ripeness and so was Acclaim for firmness. All melons were judged not sweet enough. Growers and distributors could use the information from this research to improve the quality and appeal of the cantaloupe melon offering in the United States. PRACTICAL APPLICATION: We profiled the sensory attributes and measured consumer liking of 15 cantaloupe cultivars. Our findings should benefit producers and consumers equally as they identified those cultivars with the most promising sensory traits and they uncovered preference segments among a population of Northern California consumers as well as drivers of liking for those segments.

Synthesis and Study of Fluorescent Forest-like Carbon Nanotubes Doped with Oxides of Rare-earth Elements

Background: Methods for obtaining the hybrids of multi-wall carbon nanotubes (MWCNTs) and rare earths are in progress. Such composites may possess luminescent properties, which could be of interest for various areas, in particular, medicine (imaging), engineering (fluorescent polymers, LED and relative materials), among other applications. Lanthanide oxides, additionally, can serve as catalysts for MWCNTs formation and catalysts of several organic reactions. Objective: The goal of this work is to obtain the composites of MWCNTs with strontium aluminate, doped with several lanthanides (Eu, Ce, La, Nd, and Sm), via the spray pyrolysis method and to study the properties of the formed hybrids. Methods: The spray pyrolysis method in the temperature range from 780 to 850oC, starting from toluene as a carbon source and ferrocene as a catalyst precursor. SrAl12O19 doped with rare-earths were added to carbon matter in the ultrasonic field. Methods: Among various structures, the forest-like nanostructures have been observed in some cases. The formed coated carbon nanotubes possess fluorescent properties due to the attachment of lanthanide- doped ceramic compound (SrAl12O19) to their surface, allowing the emission control for each dopant: yellow (Nd2O3), blue (Eu2O3 and Sm2O3), intense orange (La2O3), light orange (Ce2O3). Conclusion: MWCNTs decorated with strontium aluminate (SrAl12O19), doped with a series of lanthanide oxides (Nd2O3, Eu2O3, La2O3, Ce2O3, Sm2O3), were obtained by the spray pyrolysis technique on the surface of optical fibers. Lanthanum- and cerium-containing coatings were found to show a better deposition on the MWCNTs surface, exhibiting uniform coating. MWCNTs, coated with Nd-, Ce-, and Eu-doped SrAl12O19 were shown to reveal the best conductive properties.

Highly efficient orange–red electroluminescence enabled by fluorenone-based thermally activated delayed fluorescent emitter

A butterfly shaped orange–red thermally activated delayed fluorescent (TADF) emitter, named ACFO, is developed by integrating electron-donating (D) 9,9-dimethyl-9,10-dihydroacridine units into γ-positions of an electron-accepting (A) fluorenone core to form a D-A-D configuration. ACFO emits intense orange–red light peaking at 600 nm in toluene solution, which is significantly red-shifted compared with its benzophenone-based counterpart. Imparted with a small singlet–triplet splitting energy of 0.13 eV, ACFO exhibits distinct TADF feature with a short delayed fluorescent lifetime of 3.8 μs and displays a moderate photoluminescence quantum yield of 31%. Consequently, employing ACFO as an emitter results in orange–red organic light-emitting diodes that exhibit a maximum external quantum efficiency of nearly 11%, corresponding to a nearly 100% exciton utilization efficiency in electroluminescence process. Our finding demonstrates for the first time that fluorenone derivatives can be employed as TADF emitters for high-efficiency fluorescent organic light-emitting diodes.

Influence of morphology on luminescence properties of xenotime-type phosphors NaYP2O7:Eu3+ synthesized via solid state and citrate-gel routes

A series of Eu3+ activated xenotime type rare earth phosphate NaYP2O7 based orange–red emitting phosphors have been prepared via solid state (SS) and citrate gel (CG) methods. The morphological variation of the developed phosphors concerning synthesis method and heat treatment has significantly influenced the luminescence properties. The phosphors synthesized by the CG route reveals the formation of homogeneous powder with small particles along with uniform size. The developed phosphors exhibit intense orange–red emission under 394 nm near UV excitation with a full width half maximum ~ 2 nm. Compared with the phosphors synthesized by SS route, the phosphors obtained by CG method possess enhanced and sharper orange–red emission with longer lifetimes due to the 5D0–7F1–2 transitions. The developed narrow red emitting phosphors have better emission intensity in comparison with commercially available Y2O3:Eu3+ red phosphors. Thus, these phosphors could be a suitable candidate for solid state lighting applications for the fabrication of white light emitting diodes.

Simultaneous Spectrophotometric Determination of Salbutamol by Coupling with Diazotized 4-Aminobenzoic acid

A simple, rapid and sensitive spectrophotmetric method for trace determination of salbutamol (SAL) in aqueous solution and in pharmaceutical preparations is described. The method is based on the diazotization coupling reaction of the intended compound with 4-amino benzoic acid (ABA) in alkaline medium to form an intense orange, water soluble dye that is stable and shows maximum absorption at 410 nm. A graph of absorbance versus concentration indicates that Beer’s law is obeyed over the concentration range of 0.5-30 ppm, with a molar absorbtivity 3.76×104 L.mol-1 .cm-1 depending on the concentration of SAL. The optimum conditions and stability of the colored product have been investigated and the method was applied successfully to the determination of SAL in dosage forms.

Structural and photoluminescence investigations of Sm3+ doped BaY2ZnO5 nanophosphors

BaY2ZnO5:Sm3+ nanophosphor was successfully synthesized using solution combustion process. XRD and photoluminescence (PL) techniques were used to analyze the structural and photoluminescence properties. Morphological study of the thermally stable powder was carried out using transmission electron microscope (TEM). Rietveld refinement technique has been used to analyze the samples qualitatively as well as quantitatively. X-Ray diffraction analysis confirms that the highly crystalline single phased Sm3+ doped BaY2ZnO5 nanophosphor crystallizes in orthorhombic lattice with Pbnm space group. The average particle size lies in the range 80–90nm with spherical morphology. The photoluminescence excitation at 411nm yields an intense orange–red emission centered at 610nm due to 4G5/2–6H7/2 transition. The concentration dependent luminescent behavior of BaY2(1−x)Sm2xZnO5 nanophosphor shows that the optimum concentration for best luminescence is 3mol%. These results indicate that these nanophosphors find potential applications in the field of phosphor-converted white LED systems.

PM 7/124 (1) Spodoptera littoralis, Spodoptera litura, Spodoptera frugiperda, Spodoptera eridania

Contents Specific scope 410 1. Introduction 411 2. Identity 411 3. Detection 411 4. Identification 412 4.1. Morphological identification 412 4.1.1. Eggs 412 4.1.2. Larvae 412 4.1.2.1. Introduction 412 4.1.2.2. General description Spodoptera larvae 413 4.1.2.3. Spodoptera littoralis and S. litura 414 4.1.2.4. Spodoptera eridania 417 4.1.2.5. Spodoptera frugiperda 419 4.1.2.6. Possible confusion with Spodoptera exigua 421 4.1.3. Pupae 422 4.1.3.1. General description 422 4.1.3.2. Possible confusion with Spodoptera exigua 422 4.1.4. Adults 422 4.1.4.1. Introduction 422 4.1.4.2. Spodoptera littoralis 424 4.1.4.3. Spodoptera litura 425 4.1.4.4. Spodoptera eridania 427 4.1.4.5. Spodoptera frugiperda 429 4.2. Molecular methods 430 5. Reference material 430 6. Reporting and documentation 430 7. Performance criteria 430 8. Further information 431 9. Feedback on this diagnostic protocol 431 10. Protocol revision 431 11. Acknowledgements 431 12. References 431 Appendix 1: Features of Lepidoptera larvae 433 Appendix 2: Keys to adults based on external morphology 434 Appendix 3: Information on genitalia 435 Appendix 4: Identification of Spodoptera eridania and S. frugiperda using real‐time PCR 441 Appendix 5: Identification of Spodoptera littoralis and S. litura using real‐time PCR 442 Specific scopeThis Standard provides guidance for the identification of S. littoralis, S. litura, S. frugiperda and S. eridania.Specific approval and amendmentThis Standard was approved in 2015‐09.

Uniform KCaY(PO4)2:Eu3+ phosphors: sol–gel method, morphology and luminescence properties

Eu3+ doped KCaY(PO4)2 (KCYP) phosphors with irregular, hemispherical and spherical morphologies are successfully synthesized via a sol–gel method. The crystalline structure, morphology and luminescence properties of these phosphors are characterized by powder X-ray diffraction, scanning electron microscopy and photoluminescence spectroscopy. Under the excitation wavelength of near-ultraviolet (n-UV) 392 nm, the as-prepared KCYP:0.03Eu3+ phosphor exhibits an intense orange–red emission at 588 nm corresponding to 5D0 → 7F1 transition of Eu3+. The effect of synthesis conditions such as the dose of citric acid and pH of the precursor solution on the morphology and luminescence intensity of the phosphors is discussed in detail. The morphologies of KCYP:0.03Eu3+ phosphors vary from a small amount of spheres to aggregated hemispheres and then to smooth spheres by increasing the molar ratio of citric acid to metal ions in the host. The highest emission intensity can be obtained at the molar ratio of citric acid to metal ions 2:1 and pH = 8.0, respectively.

Anticancer Effect and Apoptosis Induction of Gambogic Acid in Human Leukemia Cell Line K562 In Vitro.

BackgroundThe aim of this study was to investigate the anticancer effect and related mechanisms of gambogic acid (GA), a traditional Chinese medicine, on human leukemia cell line K562, together with the effect on bone marrow mononuclear cells (MNCs).Material/MethodsK562 cells and MNCs were treated with various concentrations and treatment times of GA. Inhibitory rate was detected by use of the Cell Counting Kit-8 (CCK-8) assay. Apoptosis was analyzed by morphological detection, Annexin-V/PI doubling staining, and TUNEL assays. The expression changes of pivotal proteins were evaluated by Western blotting.ResultsGA not only suppressed cell proliferation, but also induced apoptosis of K562 cells in a dose-dependent manner. While it did not significantly inhibit cell proliferation of MNCs, it did induce apoptosis in a dose-dependent manner. CCK-8 assay revealed that the proliferation of K562 cells was significantly inhibited when the concentration of GA was more than 0.5 μM. Morphological detection showed the nuclei became denser and more intense orange in K562 cells after GA treatment compared with the untreated group. The expression levels of BCL-2, nuclear factor-κB (NF-κB), c-myc, phosphatidylinositol3-kinase (PI3K), and phosphorylation of serine-threonine kinase (p-AKT) were down-regulated by GA.ConclusionsGA significantly suppressed the proliferation of K562 cells, but has less effect on MNCs. The inhibition of K562 cells proliferation and apoptosis induced by GA might be related to the down-regulation of BCL-2, NF-κB, c-myc, PI3K, and p-AKT.