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1.
PLoS One ; 18(6): e0285720, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37267373

RESUMO

The manufacturing sector's adherence to managing natural resources from the environment still needs to be improved. This study's objective is to determine how Corporate Social Responsibility (CSR) influences the financial performance of manufacturing firms featured in the LQ45 Index, as measured by Return on Assets (ROA), Return on Equity (ROE), and Net Profit Margin (NPM). All manufacturing companies that are included in the LQ45 Index's population for this study were sampled using the purposive sampling method. This study uses secondary data from the CSRI based on the Global Reporting Initiative (GRI) G4 standard for 2018-2020 and the annual reports of companies in the manufacturing industry sector listed on the LQ45 Index. Moreover, applying a quantitative methodology, descriptive statistical methods, conventional assumption tests, and simple linear regression analysis were applied in this study's data analysis. The results of the study proved that CSR has a significant effect on ROA but does not affect the ROE and NPM of LQ45 manufacturing companies. In accordance with the signaling theory, CSR disclosure sends a favourable message to outsiders, which stakeholders and shareholders will respond to through changes in business earnings. CSR implementation can establish a positive image for the company, but it can also improve the company's image in both the commodity and capital markets. Investors will be more attracted to a company with a positive corporate image since a positive corporate image increases consumer loyalty. As consumer loyalty rises, the company's sales will likewise rise, and its profitability will increase as a result. This paper opens a new research path in corporate social responsibility and financial performance for possible links among variables; a matter that has not been previously explored in Indonesia Manufacturing Public Companies.


Assuntos
Comércio , Revelação , Indonésia , Indústria Manufatureira , Renda , Responsabilidade Social
2.
Heliyon ; 8(9): e10556, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36148275

RESUMO

Purpose: Palm oil is the leading commodity of the plantation sub-sector in Indonesia, providing a tremendous economic impact for the people and the government. However, the development of oil palm plantations raises the issue of environmental damage because oil palms use large quantities of water. The purpose of this study is to explore circular water management accountability practices through disclosures issued by each company and the effectiveness of water management voluntary disclosure under the Global Reporting Initiative (GRI) standards on increasing stakeholder trust and reducing information asymmetry. Design/methodology/approach: This study used secondary data collected from reports published by plantation sub-sector companies listed on the Indonesia Stock Exchange (IDX) and accessible online. Analysis was performed using the method of Miles and Huberman (1992): data reduction, data presentation, conclusion drawing, and verification. Data reduction was conducted by identifying plantation sub-sector companies that reported water management practices consecutively from 2018 to 2020 and seeking all disclosures related to water management and circular water management practices with 3R indicators. Data presentation was carried out by presenting findings from circular water management disclosures and comparing inter-year circular water management accountability practices to examine reporting routines. Finally, conclusions were drawn and verified. Findings: The results of this study show that only six of the 20 plantation sub-sector companies reported circular water management with 3R indicators for three consecutive years (2018-2020). Two of these six companies attached GRI index references to their reports consisting of GRI 303 (Water and Effluents) and GRI 306 (Waste), while the other four did not. In addition, water management voluntary disclosure under the GRI standards was shown to increase stakeholder trust and reduce information asymmetry. Originality/value: This study raises the concepts of water accounting and circular water management accountability practices in plantation sub-sector companies listed on Indonesia Stock Exchange (IDX).

3.
Zhongguo Zhong Yao Za Zhi ; 47(10): 2643-2651, 2022 May.
Artigo em Chinês | MEDLINE | ID: mdl-35718482

RESUMO

Despite the development of HPV vaccines and screening programs, cervical cancer is still a serious threat to women's health. Early-stage cervical cancer is mainly treated by surgery. However, considering the serious complications after surgery, hyperthermia is recommended to enhance the effect of chemotherapy, retain the integrity of cervix, improve the treatment effect, which provides a therapeutic basis for the early treatment of cervical cancer. The photosensitive liposomes containing harmine and dye IR-780 were prepared by thin-film dispersion method and separated by Sephadex G-50 dextran gel column. The preparation conditions were optimized as the mass ratio of phospholipid to cholesterol membrane material being 8∶1 and that of drug to lipid being 1∶20. The results of HPLC showed that the encapsulation efficiency of harmine was 55.6%±0.18%. The prepared photosensitive liposomes were round and evenly distributed under transmission electron microscope, with the particle size of(125.2±0.62) nm determined by Marvin particle size analyzer and the Zeta potential of(-2.55±0.76) mV. Additionally, the photosensitive liposomes had the photothermal conversion efficiency, an important property of photothermal agent, of 27.1%±0.86%. The photosensitive liposomes stored at 4 ℃ showed stable encapsulation efficiency in the first 14 days without flocculation. The sulforhodamine B(SRB) assay was employed to determine the inhibitory effect of the liposomes on the proliferation of HeLa cells under near-infrared(NIR) irradiation or not, which showcased stronger inhibitory effect under NIR irradiation. The results of Transwell assay indicated that the prepared liposomes significantly inhibited the invasion and migration of HeLa cells in vitro. The findings of this study provide a basis for the treatment of cervical cancer with harmine.


Assuntos
Lipossomos , Neoplasias do Colo do Útero , Feminino , Harmina/farmacologia , Células HeLa , Humanos , Tamanho da Partícula , Neoplasias do Colo do Útero/tratamento farmacológico
4.
Medicine (Baltimore) ; 97(50): e13344, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30557983

RESUMO

BACKGROUND: Lymph node detection in prostate cancer is challenging and critical to determine treatment policy. Choline PET/CT (positron emission tomography/computed tomography) and magnetic resonance imaging (MRI) have been used for the evaluation of lymph node metastasis in patients with prostate cancer for the past decade. However, only limited patients underwent direct comparison studies. PURPOSE: To evaluate the diagnostic performance of choline PET/CT compared with MRI imaging for detecting lymph node metastases in prostate cancer patients. MATERIAL AND METHODS: Relevant English-language articles published before February 2018 were searched in PubMed database, Embase database, and Cochrane Library databases search using the keywords: (Prostate Neoplasm OR Prostate Cancer OR prostate carcinoma) and (Lymph Node) and (PET/CT OR positron emission tomography/computed tomography) and (choline or 2-hydroxy-N,N,N-trimethylethanaminium) and (magnetic resonance imaging OR MRI). Articles were included that directly compare the diagnostic performance and clinical utility of choline PET/CT and MRI for detecting lymph node metastases in prostate cancer patients. Study quality was assessed with QUADAS criteria. Analyses were performed on a per patient and a per node basis. The pooled sensitivity, specificity, diagnostic odds ratio (DOR), positive likelihood ratio (LR+), and negative likelihood ratio (LR-) were calculated using Meta-Disc 1.4 software. Summary receiver-operating characteristic (SROC) curves constructed. RESULTS: A total of 362 patients from 8 studies involving fulfilled the inclusion criteria. On patient-based analysis, the pooled sensitivity, specificity, and DOR with a 95% confidence interval (CI) for choline PET/CT imaging were 0.59 (95%CI, 0.50-0.67), 0.92 (95%CI, 0.87-0.96), 17.37 (95%CI, 4.42-68.33), and for MRI imaging, they were 0.52 (95%CI, 0.44-0.61), 0.87 (95%CI, 0.81-0.92), 6.05 (95%CI, 3.09-11.85), respectively. On node-based, the corresponding values for choline PET/CT imaging were 0.51 (95%CI, 0.46-0.57), 0.99 (95%CI, 0.98-0.99), 65.55 (95%CI, 23.55-182.45), and for MRI imaging, they were 0.39 (95%CI, 0.34-0.44), 0.97 (95%CI, 0.96-0.97), 15.86 (95%CI, 8.96-28.05), respectively. CONCLUSION: Choline PET/CT performed better than MRI imaging in evaluating the lymph nodes metastasis of prostate cancer patients and had the potential to be broadly applied in clinical practice.


Assuntos
Metástase Linfática/diagnóstico , Imageamento por Ressonância Magnética/normas , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/normas , Neoplasias da Próstata/complicações , Idoso , Colina/uso terapêutico , Humanos , Metástase Linfática/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Curva ROC
5.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 24(5): 1416-1420, 2016 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-27784367

RESUMO

OBJECTIVE: To investigate the PET/CT features of primary central nervous system lymphoma(PCNSL). METHODS: A retrospective analysis of PET/CT imaging manifestations and clinical data was performed in 4 PCNSL cases which were confirmed by surgery or stereotactic pathologic biopsy. RESULTS: The pathologic biopsy in 4 patients all showed diffuse large B cell lymphoma with a total of 8 lesions. All cases were performed with 18F-FDG PET/CT imaging except 1 patient simultaneously with 18F-FLT PET/CT imaging in the brain. Single lesion was found in 2 cases which both were located in the left frontal lobe. Multiple lesions were found in 2 cases, out of them 1 case located in the corpus callosum and the right lateral ventricle Angle, and the other 1 located in dual lateral ventricle and pineal region. In 18F-FDG PET/CT image, 4 patients were characterized by high metabolism, even higher than the surrounding brain tissue. The patient which underwent 18F-FLT PET/CT imaging was also presented with high metabolism and had better Target and non-target ratio(T/N). 3 cases with surrounded by edema and 2 cases with area of cystic necrosis. CONCLUSION: PCNSL are characterized by high metabolism in 18F-FDG PET/CT images and can better contrast with the surrounding normal brain. Combined use of other tracer such as 18F-FLT can improve the diagnostic value of PET/CT in PCNSL.


Assuntos
Neoplasias do Sistema Nervoso Central , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Biópsia , Fluordesoxiglucose F18 , Humanos , Linfoma Difuso de Grandes Células B , Tomografia por Emissão de Pósitrons , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Receptor 1 de Fatores de Crescimento do Endotélio Vascular
6.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(2): 336-9, 2016 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-27209726

RESUMO

X-ray imaging has a very important role in life sciences and material microstructure analysis and other applications. One of the core components of X-ray imaging equipment is the X-rays-visible light conversion screen. Flashing transparent film is an effective way to achieve high spatial resolution X-ray imaging. M'-type LuTaO4: Eu³+ is an excellent scintillation material. It has high light yield, high density, good radiation hardness and good chemical stability. Therefore, to research and develop the transparent conversion screen with M'-type LuTaO4: Eu+ is very important for the application of X-ray detector in high spatial resolution X-ray imaging. In this paper, the M'-type LuTaO4:Eu³+ transparent scintillator films were successfully prepared from the inorganic salt and 2-methoxyethanol solution containing polyvinylpyrrolidone (PVP) via sol-gel technique, and transmittance, photoluminescence, X-ray excitation emission spectral and spatial resolution, and a series of film properties were characterized. A film thickness of about 2.1 µm was achieved after 8 coatings. The thick film was homogeneous and crack free, and the transmittance was approximately 70% in its emission region. The spatial resolution of the thick film was 1.5 µm, which measured by the standard spatial resolution panels. An X-ray imageof fruit fly was obtained by using this thick film. Additionally, thesol-gel derived M'-type LuTaO4:Eu³+ thick film revealed excellent photoluminescence and X-ray excited luminescence per- formances. All results indicated that the M'-type LuTaO4:Eu³+ thick films have satisfied the essential requirements for applications in high-spatial-resolution X-ray imaging.


Assuntos
Diagnóstico por Imagem/instrumentação , Luminescência , Animais , Drosophila , Raios X
7.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(4): 1079-83, 2015 Apr.
Artigo em Japonês | MEDLINE | ID: mdl-26197605

RESUMO

Micro-columnar structured γ-CuI scintillation conversion screen with columnar diameter in the micrometer and thickness about 17 µm were prepared by thermal evaporation method on quartz substrates with different temperatures. X-ray excited luminescence spectra of the screens show two peaks located at 430 nm and near 700 nm, which correspond to the fast and slow emission components, respectively. The fast one dominated. The intensity of 430 nm peak decreased as the substrate temperature rose from 170 °C to 210 °C. At the same time the intensity of 700 nm band increased. The changes may be attributed to the iodine loss from screen caused by the substrate temperature. The phenomenon of iodine loss was observed by the Rutherford backscattering experiment. The crystal structure of the screens presents (111) preferred orientation, which is independent of the substrate temperature. As the temperature rose to 210 °C, two weak additional peaks of (220) and (420) γ-CuI crystal planes in X-ray diffraction patterns appeared due to the increase in kinetic energy of CuI molecules. The scanning electron microscopy images of the screens showed that the columnar structure was improved when the substrate temperature increased from 170 °C to 190 °C, but it would be degenerated when the temperature continued to rise to 210 °C because of the surface and bulk diffusion effects of the depositing molecules. Finally, the spatial resolution of the γ-CuI scintillation screens was measured by knife-edge method, and they are 4.5, 7.2 and 5.6lp · mm(-1) for the screens prepared at the substrates temperatures of 170, 190 and 210 °C, respectively. The result shows that micro-column structure could improve the spatial resolution of γ-CuI scintillation screen.

8.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(11): 3036-40, 2015 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-26978903

RESUMO

Hydrophobic, monodisperse LaPO4: Ce³âº nanoparticles, LaPO4:Ce³âº/LaPO4 and LaPO4:Ce³âº/LaPO4: Ce³âº/ LaPO4 core/shell structure nanocrystals were synthesized via a high-temperature organic solution approach. The as-synthesized samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and photoluminescence spectroscopy (PL). The results show that: all the samples are a monoclinic phase, Because of the size small nanoparticles, the diffraction peaks of the sample occurs width phenomenon. The LaPO4:Ce³âº nano- crystals exhibits the characteristic emission of Ce³âº ions, the photoluminescence intensity increases first and then decreases with the increasing doping concentration of Ce³âº ions, and the best doping amount is 6 at %, with the increasing doping amount, the photoluminescence intensity decreases which may caused by the concentration quenching. Compared to LaPO4:Ce³âº nanoparti- cles, the photoluminescence intensity of LaPO4:Ce³âº/LaPO4 and LaPO4: Ce³âº/LaPO4: Ce³âº/LaPO4 core/shell structure nanocrystals improves about 41% and 95% respectively, this may be a synergy of larger particle size of nanocrystals and surface passivation effect. FTIR spectra data shows that the absorption peak at 1545 and 1461 cm⁻¹ corresponded to the asymmetric and symmetric stretching vibration of --COO⁻, the separation, Δ, between the two peaks is 84 cm⁻¹, The mechanism of the sample surface modification by the organics might be that the oxygen atoms of the carboxyl are coordinated with the lanthunum ions by a bidentate mode.

9.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(3): 625-9, 2014 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-25208378

RESUMO

In-doped ZnO nanopowders were prepared by precipitation. The influence of the processing parameters, such as In doping concentration, calcination temperature, reactant ratio and type of precipitant on the grain size, structure and photolumines cence (PL) of In/ZnO nanopowders was detailed analyzed by using X-ray diffraction (XRD) and photoluminescence spectrum. The experimental results indicated that with the increase in the In doping level (the molar ratio of In3+ /Zn2+ increased from 0%. to 5%), the crystallization and the UV emission of ZnO nanopowders were reduced because of the increase of impurity defects. And the UV emission band would have a red-shift from 389 to 419 nm, which could be resulted from the effects of merging of donor and conduction bands, and potential fluctuations of impurity energy level. The calcination temperature will play an important role in synthesis of luminescence materials. When the calcination temperature was raised from 500 to 600 degrees C, the grain size of In/ZnO nanopowder increased gradually, and the dominated UV emission band was improved due to the enhanced crystallization of the nanopowder. If the temperature was raised up to 800 degrees C, the crystallization of the sample was further improved, leading to an enhanced intensity of UV emission Additionally, near this temperature, the oxygen vacancy is easier to be produced owing to the improvement of the kinetic energy for the ions in lattice, which induces in the enhancement of the green emission band peaking at 525 nrn. For the temperature up to 1,000 degrees C, the UV emission band was suppressed due to the production of excessive oxygen vacancy, and the In/ZnO nanopowder exhibited a dominated green emission. The luminescence performance of the In/ZnO nanopowder is also much affected by the reactant ratio. The reaction rate is improved by the increase of the NH4 HCO3 / Zn(NO3)2 molar ratio, which will decrease both grain size of In/ZnO nanopowder and emission intensity of UV band. Furthermore, the effect of the precipitant on the luminescence was examined. It is obviously that the NH4 HCO3 and NaOH precipitants will remarkably affect the crystallization of the precursor powder, but nearly have no effect on the luminescence property of the final nanopowder products.

10.
Luminescence ; 29(2): 132-7, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23703841

RESUMO

Red-emitting Li(2)Sr(1-3x/2)Eux SiO4 0 ≤ x ≤ 0.5) phosphors were synthesized at 900 °C in air by a solid-state reaction. The synthesized phosphors were characterized by X-ray powder diffraction, photoluminescence (PL) excitation (PLE) and PL spectra. The results from the PLE spectra suggest that the strong 394 nm excitation peak associated with the (5) L6 state of Eu(3+) ions is of significance for near ultraviolet pumped white light-emitting diodes and solid-state lighting. It is also noted that the position of the charge transfer state of Eu(3+) ions shifts towards the higher energy side (blue shift) by increasing the content of Eu(3+) ions. The predominant emissions of Eu(3+) ions under 394 nm excitation are observed at 580, 593, 614, 656 and 708 nm, which are attributed to the (5) D0 → (7)FJ (J = 0, 1, 2, 3 and 4), respectively. The PL results reveal that the optimal content of the red-emitting Li2 Sr(1-3x/2)Eux SiO4 phosphors is x = 0.475. Simulation of the white light excited by 394 nm near ultraviolet light has also been carried out for its potential white light-emitting diode applications.


Assuntos
Európio/química , Lítio/química , Luminescência , Substâncias Luminescentes/análise , Substâncias Luminescentes/química , Silicatos/química , Estrôncio/química , Medições Luminescentes
11.
Int J Clin Exp Med ; 7(12): 5170-80, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25664019

RESUMO

OBJECTIVES: Renal transplantation is the preferred method for most patients with end-stage renal disease, however, acute renal allograft rejection is still a major risk factor for recipients leading to renal injury. To improve the early diagnosis and treatment of acute rejection, study on the molecular mechanism of it is urgent. METHODS: MicroRNA (miRNA) expression profile and mRNA expression profile of acute renal allograft rejection and well-functioning allograft downloaded from ArrayExpress database were applied to identify differentially expressed (DE) miRNAs and DE mRNAs. DE miRNAs targets were predicted by combining five algorithm. By overlapping the DE mRNAs and DE miRNAs targets, common genes were obtained. Differentially co-expressed genes (DCGs) were identified by differential co-expression profile (DCp) and differential co-expression enrichment (DCe) methods in Differentially Co-expressed Genes and Links (DCGL) package. Then, co-expression network of DCGs and the cluster analysis were performed. Functional enrichment analysis for DCGs was undergone. RESULTS: A total of 1270 miRNA targets were predicted and 698 DE mRNAs were obtained. While overlapping miRNA targets and DE mRNAs, 59 common genes were gained. We obtained 103 DCGs and 5 transcription factors (TFs) based on regulatory impact factors (RIF), then built the regulation network of miRNA targets and DE mRNAs. By clustering the co-expression network, 5 modules were obtained. Thereinto, module 1 had the highest degree and module 2 showed the most number of DCGs and common genes. TF CEBPB and several common genes, such as RXRA, BASP1 and AKAP10, were mapped on the co-expression network. C1R showed the highest degree in the network. These genes might be associated with human acute renal allograft rejection. CONCLUSIONS: We conducted biological analysis on integration of DE mRNA and DE miRNA in acute renal allograft rejection, displayed gene expression patterns and screened out genes and TFs that may be related to acute renal allograft rejection.

12.
Guang Pu Xue Yu Guang Pu Fen Xi ; 33(2): 293-6, 2013 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-23697096

RESUMO

Transparent gamma-Cu I crystal with size about 9 mm x 9 mm x 1 mm was grown by using optimized solvent evaporation method with gamma-Cu I powders as raw material and acetonitrile as solvent. The results of Rutherford backscattering spectrometry (RBS) showed that the proportions of copper and iodine in as-grown gamma-Cu I crystal were 53.1 and 46.9 mol%, respectively. By iodine doping into growth solution, the proportions of copper and iodine were adjusted to 50.4 and 49.6 mol%, respectively. Photoluminescence (PL) showed that the as-grown gamma-Cu I crystal had an emission at 410 nm and an emission band around 720 nm. After iodine doping, the emission band around 720 nm was suppressed while other two weak emissions at 424 and 474 nm appeared. X-ray excited luminescence (XEL) showed that the as-grown gamma-Cu I crystal had an emission at 435 nm and an emission band around 720 nm. After iodine doping, the emission band around 720 nm was suppressed. Comparing the emission spectra before and after iodine doping, it is clear that red luminescence in gamma-Cu I crystal could be suppressed by iodine doping. The effect originated from the reduction of iodine vacancy in the crystal, but not from the iodine adsorbtion on the surface.

13.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(2): 411-4, 2012 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-22512180

RESUMO

To investigate the origin of the thermoluminescence at high temperature, Lu2SiO5 : Ce0.006 (LSO : Ce) phosphors were prepared by sol-gel chemistry in air and graphite respectively. The patterns of X-ray diffraction, excitation and emission spectra and thermoluminescence curves of these samples were analyzed. In comparison with the phosphors prepared in the air, the luminescence intensity was improved and the thermoluminescence peak at 598 K was restrained for the sample prepared in graphite. It was found that the thermoluminescence peak at 598 K was relevant to Ce4+. In order to achieve more evidences, LSO : Ce0.006, K(x) (x = 0.01-0.08) phosphors were prepared. The structures and spectra of K(+) -codoped samples were also studied. By codoping with K+ ions, the luminescence intensity of LSO : Ce phosphor could be enhanced distinctly, but the crystallinity was not improved. The results of the K(+) -codoped LSO: Ce exhibited that K(+) -codoping could improve the concentration of oxygen vacancy and restrain the peak at 598 K. When K+ ion occupied the position of Lu3+, more oxygen vacancies could be created and Ce4+ turned into Ce3+ simultaneously due to the balance of electric charge, which was consistent with the result of the thermoluminescence. So it can also come to the conclusion that the thermoluminescence peak at 598 K was relevant to Ce4+. The reason for K+ ions enhancing the intensity of LSO : Ce can be attributed to the improvement of concentration ratio for Ce3+/Ce4+.

14.
Opt Express ; 19(23): 23460-8, 2011 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-22109223

RESUMO

For practical application of x-ray in-line phase contrast imaging, a high-quality image is essential for object perceptibility and quantitative imaging. The existing approach to improve image quality is limited by high cost and physical limitations of the acquisition hardware. A useful image restoration algorithm based on fast wavelet transform is proposed. It takes advantage of degradation model and extends the modulation transform function (MTF) compensation algorithm from Fourier domain to wavelet domain. The modified algorithm is evaluated through comparison with the conventional MTF compensation algorithm. Its deblurring property is also characterized with the evaluation parameters of image quality. The results demonstrate that the modified algorithm is fast and robust, and it can effectively restore both the lost detail and edge information while ringing artifacts are reduced.

15.
Guang Pu Xue Yu Guang Pu Fen Xi ; 31(6): 1720-2, 2011 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-21847966

RESUMO

Tb(3+)-doped silicate scintillating glass was made by high temperature melt-quenching method and the energy response to hard X-ray (from 5 to 80 keV) was measured. The response of photocurrent of silicate scintillating glass to X-ray (with various energy) is nonlinear. It was noted that the change in nonlinearity around 8 and 50 keV is obvious. This phenomenon is concerned with the production of abundant electrons when the scintillating glass absorbed X-ray and the energy response of scintillating glass to electrons.

16.
Guang Pu Xue Yu Guang Pu Fen Xi ; 31(2): 344-8, 2011 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-21510377

RESUMO

To achieve high-spatial-resolution for X-ray imaging and flat panel display, transparent thin-film phosphors have been attracted much attention in recent years. In comparison with conventional powder phosphors, the transparent thin-film phosphors have some outstanding advantages such as high contrast and resolution, superior thermal conductivity and better adhesion. Cerium-doped lutetium oxyorthosilicate Lu2 SiO5 (LSO) is one promising candidate due to its high density (7.4 g x cm(-3)), high light yield (27 300 photons x MeV(-1)), short decay time (40 ns), and excellent chemical stability. The sol-gel method is one of the most important techniques for deposition of functional thin films, because it possesses a number of advantages over conventional film formation techniques, such as low processing temperature, easy coating of large surfaces, homogenous multicomponent films, and cheap equipments. In X-ray imaging application, the thickness of the thin-film phosphor is the most important factor, which can increase X-ray absorption of the film and then strengthen its luminescence intensity. In the present work, transparent LSO : Ce film was successfully prepared using sol-gel method and spin-coating technique by using inorganic salts as raw materials, 2-methoxyethanol as solvent, and poly (ethylene glycol) (PEG) as modifier without inert atmosphere. The effect of PEG on the luminescence properties of the film was investigated in detail. The results indicated that PEG200 played an important role in the formation of LSO : Ce film, improving its quality and luminescent intensity. The film thickness of 0.9 microm was achieved after 5 times of coating. The luminescence properties of the film were studied. Their performances were good, which implied that the film would have promising applications in high-spatial-resolution X-ray imaging and flat panel display devices.

17.
Nanoscale Res Lett ; 5(12): 1977-81, 2010 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-21170406

RESUMO

Porous alumina films had been fabricated by anodizing from aluminum films after an electropolishing procedure. Alumina stripes without pores can be distinguished on the surface of the porous alumina films. The width of the alumina stripes increases proportionally with the anodizing voltage. And the pores tend to be initiated close to the alumina stripes. These phenomena can be ascribed to the electric field distribution in the alumina barrier layer caused by the geometric structure of the aluminum surface.

18.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(9): 2317-20, 2010 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-21105386

RESUMO

The XRD, emission and IR transmission spectra of Li-doped GdTaO4:Eu3+ phosphors were measured. Judd-Ofelt theory was applied, and the intensity parameters omega2 of Eu3+ for optical transition were calculated. The results show that Li+ codoping can enhance the luminescence intensity of GdTaO4:Eu3+. The intensity can be improved up to 1.7 and 1.5 times, respectively, when x = 0.06 and 0.10. The phenomenon results not from the assumption that Li+ codopant can reduce the crystal symmetry of GdTaO4:Eu3+ so as to relax the parity forbidden transition, but from the flux effect of Li+ codopant which can improve the crystallinity of GdTaO4:Eu3+ and suppress the Gd2O3 and Ta2O5 hetero phases. Gd(0.92-x)Li(x)TaO4:Eu0.08(3+) has not only quite a good crystallinity but also less Gd2O3 and Ta2O5 hetero phases when x = 0.06 or 0.10. Therefore, their luminescence intensities can be improved evidently.

19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(3): 603-6, 2010 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-20496669

RESUMO

High-resolution X-ray imaging systems require materials with good scintillation performances, especially X-ray absorption performance. Compared with powder phosphors display devices, those with transparent crystalline phosphors are very interesting due to their higher contrast and resolution for having no optical scattering, superior thermal conductivity as well as high degree of uniformity and better adhesion. Europium-doped gadolinlum oxide is a promising candidate due to its high density (7.62 g x cm(-3)), good light yield (18.5 x 10(3) photons/MeV), and the red emission of Eu3+ ion. The sol-gel method is one of the most important techniques for deposition of functional films, because it possesses a number of advantages over conventional film formation techniques, such as low processing temperature, easy coating of large surfaces, and homogenous multicomponent oxide films. In X-ray imaging application, the thickness of the film is the most important factor for commercial use, which can increase X-ray absorption of the film and then strengthen its luminescence yield. In the present work, transparent Gd2 O3 : Eu3+ thick film was successfully prepared using sol-gel method and spin-coating technique by choosing Ln2 O3 (Ln = Gd, Eu) as raw materials, 2-methoxyethanol as solvent, PVP as adhesive and PEG200 as surface modifier. The film was homogeneous and crack free. The thickness of the film could achieve 1.5 microm after 2 times of coating, and its transmittance was approximately 80% in visible region. It was shown that PVP played an important role in film preparation, which could suppress stress and increase viscidity of the sol. In addition, the excitation, emission and decay time of the Gd2 O3 : Eu3+ scintillator film were studied. Their performances were quite good, which implied that the film would have promising applications in high-spatial-resolution X-ray imaging and flat panel display devices.

20.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(2): 308-12, 2010 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-20384113

RESUMO

In the present work, the SnF2 powder was modified by silane coupling agent KBM403. The Fourier transform infrared spectrum (FTIR) of the modified powder showed that KBM403 was absorbed on the surface of SnF2 particles through physical absorption besides a weak chemical absorption. Then the SnF2 powder was modified by the solution dissolved with stilbene 3. The modified SnF2 powder could improve the decentralization of stilbene 3 dopant. An organic-inorganic hybrid luminescence glass was prepared by doping the modified SnF2 powder with stilbene 3 into the low melting lead-tin-fluorophosphate (PTFP) glass. The excitation, emission and transmission (absorption) spectra were used to characterize the hybrid glass. The results showed that introducing KBM403 could improve solubility and decentralization of stilbene 3 in PTFP glass, reduce the concentration of stilbene 3 dimers, and increase the transparency and homogeneity of the glass. Meanwhile, the luminescence intensity of stilbene 3 in this hybrid glass increased evidently compared with that of the stilbene 3 doped glass. The effect was assumed to be the reduction of the quenching of luminescence from stilbene 3 dimer and the enhancement of the rigidity of stilbene 3 molecules due to the interaction between KBM403 and stilbene 3.

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