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1.
Pain Physician ; 26(3): E203-E211, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37192243

RESUMO

BACKGROUND: Although several studies have examined the epidemiological features of vertebral compression fractures (VCF) among elderly patients, few studies have reported the epidemiology of VCF among younger individuals. OBJECTIVE: To examine trends in the incidence and mortality of VCF in both the old (>= 65 years) and young (< 65 years) age groups. This study aimed to investigate the incidence and mortality of VCF among all age groups in Korea. STUDY DESIGN: Population-based cohort study. SETTING: A nationwide, population-based setting. METHODS: Using the Korean National Health Insurance database, which has complete population coverage, we identified patients diagnosed with VCF between 2005 to 2018. Differences in incidence, survival and mortality were compared across groups using Kaplan-Meier analysis and Cox regression for all age groups and both genders. RESULTS: We identified a total of 742,993 VCF patients and the annual incidence was 140.09/100,000 individuals. Although the incidence of VCF was significantly higher in the older age compared to younger age group (556.38/100,000 vs. 44.09/100,000 individuals), the mortality rate ratio for VCF patients was higher among younger compared to older individuals (old: 1.59 vs. young: 2.87). In our multivariable-adjusted analysis, the hazard ratio for multiple fractures, traumatic injury and osteoporosis were higher in patients aged < 65 years compared to patients aged >= 65 years, suggesting that the impact of these clinical variables on mortality is more significant in the younger age group. LIMITATION: A limitation of this study was its lack of information on clinical features, such as disease severity and laboratory data. The precise cause of death of VCF patients could not be confirmed from the study database. CONCLUSIONS: The mortality rate ratio and hazard ratio were significantly higher among younger patients with VCF, indicating the need for further research on VCF in younger age groups.


Assuntos
Fraturas por Compressão , Osteoporose , Fraturas da Coluna Vertebral , Idoso , Humanos , Masculino , Feminino , Fraturas por Compressão/epidemiologia , Estudos de Coortes , Incidência , Fraturas da Coluna Vertebral/epidemiologia , Fraturas da Coluna Vertebral/etiologia , Osteoporose/complicações , República da Coreia/epidemiologia
2.
J Nanosci Nanotechnol ; 20(9): 5804-5807, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32331185

RESUMO

Ti-SBA-15 catalysts doped with cerium ion were synthesized using conventional hydrothermal method and they were characterized by XRD, FT-IR, DRS, BET and PL. We also examined the activity of these materials on the photocatalytic decomposition of orange II. Ti-SBA-15 catalysts doped with cerium ions maintained the mesoporous structure regardless of the doping amount of cerium ion. 5 mole% Ce/Ti-SBA-15 catalysts showed the highest photocatalytic activity on the decomposition of orange II, however, the catalysts doped with less than 3 mole% Ce/Ti-SBA-15 showed lower activity compared to pure Ti-SBA-15 catalyst. The PL peaks appeared at about 410 nm at all catalysts and the excitonic PL signal was proportional to the photocatalytic activity for the decomposition of orange II.

3.
J Clin Microbiol ; 58(2)2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31748320

RESUMO

There are several convenient and accurate molecular assays to detect respiratory bacterial infection. The NeoPlex RB-8 detection kit (NeoPlex RB-8) is a new multiplex real-time PCR assay that simultaneously detects Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydophila pneumoniae, Legionella pneumophila, Haemophilus influenzae, Bordetella pertussis, Bordetella parapertussis, and Moraxella catarrhalis in a single test. This study compared the clinical concordance of NeoPlex RB-8 with another method, Seeplex PneumoBacter ACE detection assay (Seeplex PB ACE), which simultaneously detects S. pneumoniae, M. pneumoniae, C. pneumoniae, L. pneumophila, H. influenzae, and B. pertussis We tested 2,137 nasopharyngeal swab and sputum specimens using both assays. For discordant Bordetella parapertussis and M. catarrhalis specimens, we also performed bidirectional sequencing. For S. pneumoniae, M. pneumoniae, C. pneumoniae, L. pneumophila, H. influenzae, and B. pertussis, which are detected by both NeoPlex RB-8 and Seeplex PB ACE, the positive and negative agreement between the two assays ranged from 91.7 to 100% (κ = 0.918 to 1). S. pneumoniae and H. influenzae were the most discordant targets and measured with higher sensitivity and specificity by NeoPlex RB-8 than Seeplex PB ACE. For Bordetella parapertussis and M. catarrhalis, which are not detected by Seeplex PB ACE, NeoPlex RB-8 sensitivity and specificity were >99%. Overall, NeoPlex RB-8 was highly comparable to Seeplex PB ACE, but NeoPlex RB-8 was more clinically accurate, with higher throughput and more convenience.


Assuntos
Bactérias/classificação , Infecções Bacterianas/diagnóstico , Reação em Cadeia da Polimerase Multiplex/normas , Kit de Reagentes para Diagnóstico/normas , Infecções Respiratórias/microbiologia , Bactérias/patogenicidade , Infecções Bacterianas/microbiologia , Humanos , Reação em Cadeia da Polimerase Multiplex/métodos , Nasofaringe/microbiologia , Infecções Respiratórias/diagnóstico , Sensibilidade e Especificidade , Escarro/microbiologia
4.
Medicine (Baltimore) ; 98(35): e16601, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31464895

RESUMO

BACKGROUND: Lactobacillus paracasei and Glycyrrhiza glabra have been reported as having beneficial effects on Helicobacter pylori infection. We aimed to assess the efficacy and safety of fermented milk containing L paracasei HP7 and G glabra in patients with H pylori infection. METHODS: This multicenter, prospective, randomized, double-blind, placebo-controlled clinical trial was conducted in 2 hospitals from April to December 2017. Patients with H pylori infection were randomized into either the treatment group (fermented milk with L paracasei HP7 and G glabra) or placebo group (fermented milk only) once daily for 8 weeks. The primary endpoint was the gastric load of H pylori measured by C-urea breath test (UBT). Secondary endpoints were histologic and clinical improvement. RESULTS: A total of 142 patients were randomly allocated to the treatment (n = 71) or placebo groups (n = 71). Compared to baseline data, the quantitative value of C-UBT at 8 weeks was significantly reduced in the treatment group (from 20.8 ±â€Š13.2% to 16.9 ±â€Š10.8%, P = .035), but not in the placebo group (P = .130). Chronic inflammation improved significantly only in the treatment group (P = .013), whereas the neutrophil activity deteriorated significantly only in the placebo group (P = .003). Moreover, the treatment group had significant improvement in gastrointestinal symptoms (P = .049) and quality of life (P = .029). No serious adverse events were observed. CONCLUSION: The combination of fermented milk containing L paracasei and G glabra reduced H pylori density and improved histologic inflammation. However, their mechanisms of action should be elucidated in further studies.


Assuntos
Glycyrrhiza/fisiologia , Infecções por Helicobacter/tratamento farmacológico , Lacticaseibacillus paracasei/fisiologia , Leite/microbiologia , Probióticos/administração & dosagem , Adulto , Idoso , Animais , Testes Respiratórios , Método Duplo-Cego , Feminino , Fermentação , Infecções por Helicobacter/imunologia , Infecções por Helicobacter/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Probióticos/efeitos adversos , Estudos Prospectivos , Qualidade de Vida/psicologia , Resultado do Tratamento , Adulto Jovem
5.
J Nanosci Nanotechnol ; 19(12): 7696-7701, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31196277

RESUMO

A highly crystallized monoclinic-scheelite type BiVO4 powder was successfully synthesized using the solvothermal method. The as-synthesized BiVO4 powder was characterized by XRD, FE-SEM, Raman spectroscopy, UV-Vis DRS spectroscopy, and TA-PL. Based on the XRD data and Raman spectra, the monoclinic-scheelite type BiVO4 samples can be obtained at solvothermal synthesis temperatures higher than 140 °C. The preparation conditions, such as the Bi/V molar ratio and synthesis temperature, play an important role in controlling the morphologies of the BiVO4 samples. The BVO 2 sample shows the highest photocatalytic activity, as well as the highest formation rate of OH radicals and the highest PL peak. This result suggests that the formation rate of OH radicals is well correlated with the photocatalytic activity.

6.
Nanomaterials (Basel) ; 9(2)2019 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-30744163

RESUMO

Chloramphenicol (CAP) is commonly employed in veterinary clinics, but illegal and uncontrollable consumption can result in its potential contamination in environmental soil, and aquatic matrix, and thereby, regenerating microbial resistance, and antibiotic-resistant genes. Adsorption by efficient, and recyclable adsorbents such as mesoporous carbons (MPCs) is commonly regarded as a "green and sustainable" approach. Herein, the MPCs were facilely synthesized via the pyrolysis of the metal⁻organic framework Fe3O(BDC)3 with calcination temperatures (x °C) between 600 and 900 °C under nitrogen atmosphere. The characterization results pointed out mesoporous carbon matrix (MPC700) coating zero-valent iron particles with high surface area (~225 m²/g). Also, significant investigations including fabrication condition, CAP concentration, effect of pH, dosage, and ionic strength on the absorptive removal of CAP were systematically studied. The optimal conditions consisted of pH = 6, concentration 10 mg/L and dose 0.5 g/L for the highest chloramphenicol removal efficiency at nearly 100% after 4 h. Furthermore, the nonlinear kinetic and isotherm adsorption studies revealed the monolayer adsorption behavior of CAP onto MPC700 and Fe3O(BDC)3 materials via chemisorption, while the thermodynamic studies implied that the adsorption of CAP was a spontaneous process. Finally, adsorption mechanism including H-bonding, electrostatic attraction, π⁻π interaction, and metal⁻bridging interaction was proposed to elucidate how chloramphenicol molecules were adsorbed on the surface of materials. With excellent maximum adsorption capacity (96.3 mg/g), high stability, and good recyclability (4 cycles), the MPC700 nanocomposite could be utilized as a promising alternative for decontamination of chloramphenicol antibiotic from wastewater.

7.
RSC Adv ; 9(41): 23526-23534, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-35530596

RESUMO

We investigated the fabrication of Co-doped BiVO4 (Bi1-x Co x VO4+δ , 0.05 < x < 0.5) by the substitution of Co ions for Bi sites in BiVO4. The X-ray diffraction (XRD), Raman, and X-ray photoelectron spectroscopy (XPS) results indicated that the substitution of Co2+ ions for Bi3+ sites in BiVO4 was successful, although a change in the crystal phase of BiVO4 did not occur. UV-vis DRS and PL results suggested that the Co-incorporation could slightly improve the visible light absorption of BiVO4 and induce the separation of photoinduced electron-hole pairs; therefore, a significant enhancement of photocatalytic performance was achieved. The Bi0.8Co0.2VO4+δ sample showed superior photocatalytic activity in comparison with other samples, achieving 96.78% methylene blue (MB) removal within 180 min. In addition, the proposed mechanism of improved photocatalytic activities and the stability of the catalyst were also investigated.

8.
J Nanosci Nanotechnol ; 19(2): 1204-1207, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30360235

RESUMO

Pure and lead-doped SrTiO3 perovskite type oxides were successfully synthesized by sol-gel method and characterized by XRD, SEM and DRS. From the results of XRD, the metal replacement with the Pb ion on the crystal lattice does not change the high crystallinity of the perovskite structure. UV-vis DRS analysis shows that Pb was in situ doped in the lattice of SrTiO3 and the absorption band shifted to a higher wavelength on the Pb-doped SrTiO3 sample compared to the pure SrTiO3 sample. We also investigated the photocatalytic activity of Pb-doped SrTiO3 for the decomposition of Rhodamine B under visible light irradiation. From the results of photocatalytic decomposition of RhB, a doping of lead into SrTiO3 perovskite oxides enhanced the photocatalytic activity under visible light irradiation.

9.
Lab Anim Res ; 34(4): 216-222, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30671108

RESUMO

The efficacy of standard therapeutic strategies for Helicobacter pylori (H. pylori) infection is decreasing over time due to the emergence of drug-resistant strains. As an alternative, the present study investigated the capacity of Lactobacilllus paracasei (L. paracasei) HP7, isolated from kimchi, to inhibit H. pylori growth. The effects of L. paracasei HP7 on H. pylori adhesion and H. pylori-induced inflammation were examined in AGS human gastric adenocarcinoma epithelial cells and a mouse model of H. pylori SS1 infection. L. paracasei HP7 reduced H. pylori adhesion to AGS cells and suppressed the inflammatory response in infected cells by downregulating interleukin-8. H. pylori colonization in the stomach of C57BL/6 mice was demonstrated by rapid urease test, and results showed significant decrease in mice post-treated with L. paracasei HP7. Additionally, L. paracasei HP7 decreased gastric inflammation and epithelial lesions in the stomach of H. pylori-infected mice. These results demonstrate that L. paracasei HP7 treatment can inhibit H. pylori growth and is thus a promising treatment for patients with gastric symptoms such as gastritis that are caused by H. pylori infection.

10.
J Nanosci Nanotechnol ; 17(4): 2690-694, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-29664582

RESUMO

A solvothermal method assisted by microwave technique has been developed for the synthesis of highly crystalline and monoclinic BiVO4 powders with ellipsoidal structure, using Bi(NO3)3 · 5H2O and Na3VO4 · 12H2O as raw materials, and oleic acid as surfactant. The phase structure and morphology of as-prepared BiVO4 samples were characterized by XRD, SEM and DRS. We have also investigated the photocatalytic activity of these materials for the decomposition of Rhodamine B under visible light irradiation. From DRS results, BiVO4 samples showed the absorption spectrum up to the visible region and then their photocatalytic activity was shown higher than commercial P-25 TiO2 materials. BiVO4 prepared by the microwave-assisted solvothermal method showed highest photocatalytic activity due to a small particle-size effect.

11.
J Nanosci Nanotechnol ; 17(4): 2751-755, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29664597

RESUMO

Lead molybdate (PbMoO4) materials were successfully synthesized using a facile surfactant-assisted microwave process and characterized by XRD, Raman, PL, BET and DRS. We also investigated the photocatalytic activity of these materials for the decomposition of Rhodamine B under UV-light irradiation. The XRD and Raman results revealed the successful synthesis of 42­69 nm, well-crystallized PbMoO4 crystals with a facile surfactant-assisted microwave process. The PbMoO4 catalysts prepared using microwave process enhanced the photocatalytic activity compared to PbMoO4 catalyst prepared by hydrothermal method. The PbMoO4 catalyst prepared at 100 °C showed the highest photocatalytic activity. The PL peak was appeared at about 540 nm for all catalysts and the excitonic PL signal was proportional to the photocatalytic activity for the decomposition of Rhodamine B.

12.
J Nanosci Nanotechnol ; 16(5): 4576-9, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27483793

RESUMO

Catalytic combustion of benzene over CuO-CeO2 mixed oxides has been investigated. The CuO-CeO2 mixed oxides were prepared using various methods and characterized by XRD, BET and TPR. For the CuO-CeO2 catalysts with a Cu/(Cu + Ce) molar ratio of more than 0.5, highly dispersed copper oxide species were shown at 2θ = 35.5 degrees and 38.8 degrees. The CuO-CeO2 catalyst prepared using co-precipitation method showed the highest activity. In addition, the highest activity is shown on Cu0.35 (the index denotes the molar ratio Cu/(Cu + Ce)) sample and then it decreases on Cu0.5 and Cu0.6 samples.

13.
J Nanosci Nanotechnol ; 16(2): 1911-5, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27433699

RESUMO

In this study, TiO2 and metal ion-doped TiO2 nanoparticles were successfully synthesized by solvothermal reaction of titanium butoxide precursor in the presence of oleic acid, oleylamine and vapor water and they were characterized by XRD, Raman, TEM and DRS. We also investigated the photocatalytic activity of these oxides for the decomposition of Rhodamine B. From XRD and Raman results, doping of the metal ion in the crystal lattice did not change the high crystallinity of the TiO2 structure, and all the metal ions were incorporated into the structures of titania as well as replaced titanium ion or located at interstitial site. The absorption band shifted to a higher wavelength on the metal ion-doped TiO2 samples compared to the pure TiO2 sample. The Ce ion- doped TiO2 catalysts showed the higher photocatalytic activity compared to the pure TiO2 and a commercial P-25 catalysts and 1% Ce-doped TiO2 showed the highest photocatalytic activity.


Assuntos
Luz , Nanopartículas/química , Processos Fotoquímicos , Titânio/química , Catálise
14.
J Microbiol Biotechnol ; 26(6): 1035-45, 2016 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-26975767

RESUMO

To evaluate the effects of lactic acid bacteria (LAB) on Peyer's patch cells, mice were treated with a high dose of kanamycin to disturb the gut microbial environment. The overarching goal was to explore the potential of LAB for use as a dietary probiotic that buffers the negative consequences of antibiotic treatment. In vitro, LAB stimulated the production of immunoglobulin A (IgA) from isolated Peyer's patch cells. Inflammation-related genes (TNF-α, IL-1ß, and IL-8) were up-regulated in Caco-2 cells stimulated with lipopolysaccharide (LPS), while tight-junction-related genes (ZO-1 and occludin) were down-regulated; the effects of LPS on inflammatory gene and tight-junction gene expression were reversed by treatment with LAB. Mice treated with a high dose of kanamycin showed increased serum IgE levels and decreases in serum IgA and fecal IgA levels; the number of Peyer's patch cells decreased with kanamycin treatment. However, subsequent LAB treatment was effective in reducing the serum IgE level and recovering the serum IgA and fecal IgA levels, as well as the number of Peyer's patch cells. In addition, ZO-1 and occludin mRNA levels were up-regulated in the ileum tissues of mice receiving LAB treatment. Lactic acid bacteria can enhance the intestinal immune system by improving the integrity of the intestinal barrier and increasing the production of IgA in Peyer's patches. Lactic acid bacteria should be considered a potential probiotic candidate for improving intestinal immunity, particularly in mitigating the negative consequences of antibiotic use.


Assuntos
Microbioma Gastrointestinal , Lactobacillus/fisiologia , Nódulos Linfáticos Agregados/imunologia , Nódulos Linfáticos Agregados/fisiologia , Probióticos/uso terapêutico , Junções Íntimas/genética , Animais , Antibacterianos/administração & dosagem , Antibacterianos/efeitos adversos , Células CACO-2 , Humanos , Imunoglobulina A/biossíntese , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina E/sangue , Interleucina-1beta/genética , Interleucina-8/genética , Canamicina/administração & dosagem , Canamicina/efeitos adversos , Lipopolissacarídeos/farmacologia , Camundongos , Ocludina/genética , Nódulos Linfáticos Agregados/citologia , Nódulos Linfáticos Agregados/microbiologia , Fator de Necrose Tumoral alfa/genética , Proteína da Zônula de Oclusão-1/genética
15.
J Microbiol Biotechnol ; 26(3): 483-7, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26699746

RESUMO

The triglyceride-lowering effect of probiotics Lactobacillus plantarum KY1032 and Lactobacillus curvatus HY7601 were investigated. Male SD Wistar rats were randomly divided into three groups and fed high-fat diet (HFD), HFD and probiotics (5 X 10(9) CFU/day of L. plantarum KY1032 and 5 X 10(9) CFU/day of L. curvatus HY7601), or normal diet for 6 weeks. Probiotic treatment significantly lowered the elevated plasma triglyceride and increased plasma free fatty acid, glycerol, and plasma apolipoprotein A-V (ApoA-V) levels. The probiotic-treated group showed elevated hepatic mRNA expression of PPARα, bile acid receptor (FXR), and ApoA-V. These results demonstrate that L. plantarum KY1032 and L. curvatus HY7601 lower triglycerides in hypertriglyceridemic rats by upregulating ApoA-V, PPARα, and FXR.


Assuntos
Hipertrigliceridemia/tratamento farmacológico , Lactobacillus plantarum/fisiologia , Lactobacillus/fisiologia , Probióticos/administração & dosagem , Triglicerídeos/metabolismo , Animais , Dieta Hiperlipídica/efeitos adversos , Suplementos Nutricionais , Modelos Animais de Doenças , Humanos , Hipertrigliceridemia/metabolismo , Fígado/metabolismo , Masculino , Ratos , Ratos Wistar
16.
J Nanosci Nanotechnol ; 15(7): 5450-4, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26373158

RESUMO

Iron-based MIL-53 crystals with uniform size were successfully synthesized using a microwave-assisted solvothermal method and characterized by XRD, FE-SEM and DRS. We also investigated the photocatalytic activity of MIL-53(Fe) for the decomposition of methylene blue using H2O2 as an electron acceptor. From XRD and SEM results, the fully crystallized MIL-53(Fe) materials were obtained regardless of preparation method. From DRS results, MIL-53(Fe) samples prepared using microwave-assisted process displayed the absorption spectrum up to the visible region and then they showed the high photocatalytic activity under visible light irradiation. The MIL-53(Fe) catalyst prepared by two times microwave irradiation showed the highest activity.


Assuntos
Ferro/química , Luz , Azul de Metileno/química , Micro-Ondas , Processos Fotoquímicos , Catálise
17.
J Nanosci Nanotechnol ; 15(1): 290-4, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26328347

RESUMO

Succinic acid (SA) produced from hydrogenation of maleic anhydride (MAN) is used widely in manufacturing of pharmaceuticals, agrochemicals, surfactants and detergent, green solvent and biodegradable plastic. In this study, we performed that liquid hydrogenation of MAN to SA with 5 wt% Pd supported on activated carbon (Pd/C) at low pressure and temperature. The synthesis of SA was performed in aqueous solution while varying temperature, pressure, catalytic amount and agitation speed. We confirmed that the composition of the products consisting of SA, maleic acid (MA), fumaric acid (FA) and malic acid (MLA) depends on the process. The catalytic characteristics were analyzed by TGA, TEM.


Assuntos
Carbono/química , Anidridos Maleicos/química , Anidridos Maleicos/metabolismo , Paládio/química , Técnicas de Química Sintética , Química Verde , Hidrogenação , Pressão , Ácido Succínico/química , Ácido Succínico/metabolismo , Temperatura
18.
J Nanosci Nanotechnol ; 15(1): 652-5, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26328419

RESUMO

LaCoO3 perovskite type oxides were successfully prepared using microwave-assisted method, characterized by TG/DTA, XRD, XPS and H2-TPR and their catalytic activities for combustion of benzene were determined. Almost of catalyst showed perovskite crystalline phase and 13-84 nm particle size. LaCoO3 catalysts prepared by microwave-assisted method showed the highest activity and the conversion reached almost 100% at 360 degrees C. In the LaCoO3-type catalyst, the partial substitution of Sr into site A enhanced the catalytic activity on the combustion of benzene. The higher amount of the chemisorbed oxygen was, the better the performance of the combustion catalyst. The catalytic activity of perovskite-type oxides showed a good relationship with the results of H2-TPR and XPS measurement.

19.
J Nanosci Nanotechnol ; 15(1): 656-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26328420

RESUMO

Cu-Zn-Al catalysts were prepared using microwave-assisted process and co-precipitation methods. The prepared catalysts were characterized by XRD, BET, XPS and TPD of ammonia and their catalytic activity for the hydrogenolysis of glycerol to propylene glycol was also examined. The XRD patterns of Cu/Zn/Al mixed catalysts show CuO and ZnO crystalline phase regardless of preparation method. The highest glycerol hydrogenolysis conversion is obtained with the catalyst having a Cu/Zn/Al ratio of 2:2:1. Hydrogen pre-reduction of catalysts significantly enhanced both glycerol conversions and selectivity to propylene glycol. The glycerol conversion increased with an increase of reaction temperature. However, the selectivity to propylene glycol increased with an increase of temperature, and then declined to 30.5% at 523 K.


Assuntos
Glicerol/química , Metais Pesados/química , Nanoestruturas/química , Propilenoglicol/química , Catálise , Técnicas de Química Sintética , Temperatura Alta , Hidrogênio , Micro-Ondas , Tamanho da Partícula , Difração de Raios X
20.
J Nanosci Nanotechnol ; 14(11): 8502-6, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25958553

RESUMO

Lead molybdate (PbMoO4) was successfully synthesized using a microwave-assisted method and characterized by XRD, Raman spectroscopy, SEM, PL and DRS. We also investigated the photocatalytic activity of these materials for the decomposition of Rhodamin B under UV-light irradiation. The XRD and Raman results revealed the successful synthesis of 42-52 nm, well-crystallized PbMoO4 crystals with the microwave-assisted hydrothermal method. The PbMoO4 catalysts prepared using the microwave-assisted process enhanced the photocatalytic activity compared to that prepared by hydrothermal method and the catalysts prepared at a solution pH = 11 and temperature of 105 degrees C showed the highest photocatalytic activity. The PL peaks appeared at about 540 nm for all catalysts and the excitonic PL signal was proportional to the photocatalytic activity for the decomposition of Rhodamin B.


Assuntos
Chumbo/química , Nanopartículas Metálicas/química , Molibdênio/química , Óxidos/química , Micro-Ondas , Nanotecnologia , Tamanho da Partícula , Processos Fotoquímicos , Rodaminas/análise , Rodaminas/química
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