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1.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 49(3): 364-368, 2018 May.
Artigo em Zh | MEDLINE | ID: mdl-30014635

RESUMO

OBJECTIVE: To determine the effects of arsenic and estrogen receptor antagonist (ICI182, 780) on the expression of estrogen receptor beta (ERß) in alveolar Ⅱ epithelial cells (AECⅡ) of female and male mice. METHODS: Nineteen or twenty day fetus mice were obtained through caesarean section of ICR mice. Purified AECⅡ cells were separated from the female and male fetus,respectively,and confirmed using immunofluorescence staining. The cells were exposed to sodium arsenite (NaAsO2) at a low,medium,or high dosage determined by MTT and cultured for 24 h. The NaAsO2 (5 µmol/L) exposed cells were compared with those treated (for 24 h) with dimethyl sulfoxide (DMSO) or ICI182, 780 (1×10-4 mol/L). Apoptosis rates of the cells were measured by flow cytometry. Real-time fluorescence quantitative PCR method and Western blot technique were used to detect the expression ofERßmRNA and protein in AECⅡ. RESULTS: Purity of AECⅡ cells reached (87.0±2.5)%. NaAsO2 exposure was set at a concentration of 0.5 (low),1.25 (medium),and 5 (high) µmol/L. The cells exposed to medium and high dosage of NaAsO2 had higher apoptosis rates than the blank controls (P<0.05),without sex differences. Female cells exposed to medium and high dosage of NaAsO2 had higher levels of expressions ofERßmRNA and protein than the blank controls (P<0.05) and male cells exposed to the same dosage of NaAsO2 (P<0.05). No significant differences were found in the expressions ofERßmRNA and protein between the exposed male cells and the blank controls. ICI182, 780 lowered the expression levels ofERßmRNA and protein in the female exposed cells (P<0.01). CONCLUSION: Arsenic exposure increases expressions of AECⅡ's ERß,more so in female cells than in male cells. This can be blocked by estrogen receptor antagonists.


Assuntos
Células Epiteliais Alveolares/metabolismo , Arsênio/toxicidade , Antagonistas do Receptor de Estrogênio/toxicidade , Receptor beta de Estrogênio/metabolismo , Fatores Sexuais , Células Epiteliais Alveolares/efeitos dos fármacos , Animais , Apoptose , Receptor alfa de Estrogênio , Feminino , Masculino , Camundongos , Camundongos Endogâmicos ICR , Gravidez
2.
Toxicol Appl Pharmacol ; 285(1): 41-50, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-25791921

RESUMO

Arsenic trioxide (ATO) is a multi-target drug approved by the Food and Drug Administration as the first-line chemotherapeutic agent for the treatment of acute promyelocytic leukemia. In addition, several clinical trials are being conducted with arsenic-based drugs for the treatment of other hematological malignancies and solid tumors. However, ATO's modest clinical efficacy on some cancers, and potential toxic effects on humans have been reported. Determining how best to reduce these adverse effects while increasing its therapeutic efficacy is obviously a critical issue. Previously, we demonstrated that the JNK-induced complex formation of phosphorylated c-Jun and TG-interacting factor (TGIF) antagonizes ERK-induced cyclin-dependent kinase inhibitor CDKN1A (p21(WAF1/CIP1)) expression and resultant apoptosis in response to ATO in A431 cells. Surprisingly, at low-concentrations (0.1-0.2 µM), ATO increased cellular proliferation, migration and invasion, involving TGIF expression, however, at high-concentrations (5-20 µM), ATO induced cell apoptosis. Using a promoter analysis, TGIF was transcriptionally regulated by ATO at the FOXO3A binding site (-1486 to -1479bp) via the c-Src/EGFR/AKT pathway. Stable overexpression of TGIF promoted advancing the cell cycle into the S phase, and attenuated 20 µM ATO-induced apoptosis. Furthermore, blockage of the AKT pathway enhanced ATO-induced CDKN1A expression and resultant apoptosis in cancer cells, but overexpression of AKT1 inhibited CDKN1A expression. Therefore, we suggest that TGIF is transcriptionally regulated by the c-Src/EGFR/AKT pathway, which plays a role as a negative regulator in antagonizing ATO-induced CDKN1A expression and resultant apoptosis. Suppression of these antagonistic effects might be a promising therapeutic strategy toward improving clinical efficacy of ATO.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Arsenicais/farmacologia , Fatores de Transcrição Forkhead/metabolismo , Proteínas de Homeodomínio/metabolismo , Neoplasias/enzimologia , Neoplasias/patologia , Óxidos/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Repressoras/metabolismo , Transcrição Gênica/efeitos dos fármacos , Antineoplásicos/toxicidade , Trióxido de Arsênio , Sítios de Ligação , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Relação Dose-Resposta a Droga , Proteína Forkhead Box O3 , Fatores de Transcrição Forkhead/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Proteínas de Homeodomínio/genética , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Células MCF-7 , Invasividade Neoplásica , Neoplasias/genética , Óxidos/toxicidade , Fosforilação , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Repressoras/genética , Transdução de Sinais/efeitos dos fármacos , Transfecção
3.
Adv Healthc Mater ; 13(12): e2303600, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38303119

RESUMO

Bone regenerative scaffolds with a bionic natural bone hierarchical porous structure provide a suitable microenvironment for cell migration and proliferation. Here, a bionic scaffold (DP-PLGA/HAp) with directional microchannels is prepared by combining 3D printing and directional freezing technology. The 3D printed framework provides structural support for new bone tissue growth, while the directional pore embedded in the scaffolds provides an express lane for cell migration and nutrition transport, facilitating cell growth and differentiation. The hierarchical porous scaffolds achieve rapid infiltration and adhesion of bone marrow mesenchymal stem cells (BMSCs) and improve the expression of osteogenesis-related genes. The rabbit cranial defect experiment presents significant new bone formation, demonstrating that DP-PLGA/HAp offers an effective means to guide cranial bone regeneration. The combination of 3D printing and directional freezing technology might be a promising strategy for developing bone regenerative biomaterials.


Assuntos
Regeneração Óssea , Células-Tronco Mesenquimais , Osteogênese , Impressão Tridimensional , Alicerces Teciduais , Regeneração Óssea/fisiologia , Animais , Coelhos , Alicerces Teciduais/química , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Osteogênese/efeitos dos fármacos , Osteogênese/fisiologia , Porosidade , Diferenciação Celular , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Engenharia Tecidual/métodos , Proliferação de Células , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Durapatita/química
4.
Adv Mater ; 36(19): e2310876, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38321645

RESUMO

Structural and physiological cues provide guidance for the directional migration and spatial organization of endogenous cells. Here, a microchannel scaffold with instructive niches is developed using a circumferential freeze-casting technique with an alkaline salting-out strategy. Thereinto, polydopamine-coated nano-hydroxyapatite is employed as a functional inorganic linker to participate in the entanglement and crystallization of chitosan molecules. This scaffold orchestrates the advantage of an oriented porous structure for rapid cell infiltration and satisfactory immunomodulatory capacity to promote stem cell recruitment, retention, and subsequent osteogenic differentiation. Transcriptomic analysis as well as its in vitro and in vivo verification demonstrates that essential colony-stimulating factor-1 (CSF-1) factor is induced by this scaffold, and effectively bound to the target colony-stimulating factor-1 receptor (CSF-1R) on the macrophage surface to activate the M2 phenotype, achieving substantial endogenous bone regeneration. This strategy provides a simple and efficient approach for engineering inducible bone regenerative biomaterials.


Assuntos
Regeneração Óssea , Durapatita , Fator Estimulador de Colônias de Macrófagos , Osteogênese , Polímeros , Receptor de Fator Estimulador de Colônias de Macrófagos , Alicerces Teciduais , Regeneração Óssea/efeitos dos fármacos , Alicerces Teciduais/química , Animais , Camundongos , Durapatita/química , Fator Estimulador de Colônias de Macrófagos/metabolismo , Fator Estimulador de Colônias de Macrófagos/farmacologia , Receptor de Fator Estimulador de Colônias de Macrófagos/metabolismo , Receptor de Fator Estimulador de Colônias de Macrófagos/química , Polímeros/química , Diferenciação Celular , Quitosana/química , Indóis/química , Transdução de Sinais , Engenharia Tecidual/métodos , Macrófagos/metabolismo , Macrófagos/citologia , Células RAW 264.7
5.
Transl Cancer Res ; 12(1): 13-30, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36760384

RESUMO

Background: Long noncoding RNA (lncRNA) can regulate tumorigenesis, angiogenesis, proliferation, and other tumor biological behaviors, and is closely related to the growth and progression of glioma. The purpose of this research was to investigate the role of angiogenesis-related lncRNA in the prognosis and immunotherapy of glioblastoma multiforme (GBM). Methods: Differential analysis was carried out to acquire angiogenesis-related differentially expressed lncRNAs (AR-DElncRNAs). The AR-DElncRNAs were then subjected to univariate Cox and least absolute shrinkage and selection operator (LASSO) analyses to construct a prognostic model. Based on the median risk score, patients were classified into high-risk and low-risk groups. Kaplan-Meier survival analysis was conducted to estimate the prognostic value of the prognostic model. In addition, a nomogram was built to predict individual survival probabilities by combining clinicopathological characteristics and a prognostic model. Furthermore, immune infiltration, immunotherapy, and drug sensitivity analyses were administered to investigate the differences between the high- and low-risk groups. Results: We identified 3 lncRNAs (DGCR5, PRKAG2-AS1, and ACAP2-IT1) that were significantly associated with the survival of GBM patients from the 255 AR-DElncRNAs based on univariate Cox and LASSO analyses. Then, a prognostic model was structured according to these 3 lncRNAs, from which we found that high-risk GBM patients had a worse prognosis than that of low-risk patients. Moreover, the risk score was determined to be an independent prognostic factor [hazard ratio (HR) =1.444; 95% confidence interval (CI): 1.014-2.057; P<0.05]. The immune microenvironment analysis revealed that the immune score, stromal score, and Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data (ESTIMATE) score were significantly higher in the high-risk group than in the low-risk group. Neutrophils, macrophages, immature dendritic cells (iDCs), natural killer (NK) CD56dim cells, activated DCs (aDCs), and uncharacterized cells were different in the high- and low-risk groups. In addition, the high-risk group had a stronger sensitivity to immunotherapy. Furthermore, the sensitivity of 28 potential chemotherapeutic drugs differed significantly between the high- and low-risk groups. Conclusions: A novel angiogenesis-related lncRNA signature could be used to predict the prognosis and treatment of GBM.

6.
Bioprocess Biosyst Eng ; 35(6): 953-62, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22249784

RESUMO

A new approach to the lipase-catalyzed hydrolytic resolution of (R,S)-azolyl carbamates for obtaining chiral azolyl carbamates and alcohol is described. With (R,S)-1-phenylethyl azolyl carbamates as the model substrates, the best reaction condition of using (R,S)-1-phenylethyl 4-bromopyrazole carbamate (1) as the substrate in water-saturated diisopropyl ether at 45 °C is selected. The kinetic constants, and hence enantiomeric ratio of 124, are then estimated from the kinetic analysis by considering the alcohol inhibition effect, with which theoretical time-course conversions for both enantiomers are numerically solved and agree with the experimental data. The thermodynamic parameters -ΔΔH and -ΔΔS satisfying a linear enthalpy-entropy compensation relationship of -ΔΔS = -38.84 + 3.29(-ΔΔH) are further estimated. An extension of the resolution platform to (R,S)-4-bromopyrazole carbamates derived from other (R,S)-alcohols (4, 5, 7) is also addressed.


Assuntos
Carbamatos/química , Álcoois Graxos/química , Lipase/química , Modelos Químicos , Enzimas Imobilizadas , Proteínas Fúngicas , Cinética , Especificidade por Substrato , Termodinâmica
7.
Genes (Basel) ; 10(4)2019 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-31010100

RESUMO

This article explores the mechanism of miR-194 on the proliferation and apoptosis of Aß1-42-transduced hippocampal neurons. Aß1-42-transduced hippocampal neuron model was established by inducing hippocampal neurons with Aß1-42. MTT assay and flow cytometry were used to detect the viability and apoptosis of hippocampal neurons, respectively. qRT-PCR was used to detect changes in miR-194 and Nrn1 expression after Aß1-42 induction. Aß1-42-transduced hippocampal neurons were transfected with miR-194 mimics and/or Nrn1 overexpression vectors. Their viability and neurite length were detected by MTT assay and immunofluorescence, respectively. Western blot was used to detect protein expression. Aß1-42 inhibited Aß1-42-transduced hippocampal neuron activity and promoted their apoptosis in a dose-dependent manner. miR-194 was upregulated and Nrn1 was downregulated in Aß1-42-transduced hippocampal neurons (p < 0.05). Compared with the model group, Aß1-42-transduced hippocampal neurons of the miR-194 mimic group had much lower activity, average longest neurite length, Nrn1, p-AkT, and Bcl-2 protein expression and had much higher Bax, Caspase-3, and Cleaved Caspase-3 protein expression. Compared with the model group, Aß1-42-transduced hippocampal neurons of the LV-Nrn1 group had much higher activity, average longest neurite length, Nrn1, p-AkT, and Bcl-2 protein expression and had much lower Bax, Caspase-3, and Cleaved Caspase-3 protein expression. Nrn1 is a target gene of miR-194. miR-194 inhibited apoptosis of Aß1-42-transduced hippocampal neurons by inhibiting Nrn1 and decreasing PI3K/AkT signaling pathway activity.


Assuntos
Peptídeos beta-Amiloides/genética , Hipocampo/citologia , MicroRNAs/genética , Neuropeptídeos/genética , Fragmentos de Peptídeos/genética , Doença de Alzheimer/genética , Doença de Alzheimer/terapia , Peptídeos beta-Amiloides/farmacologia , Animais , Apoptose , Proliferação de Células , Células Cultivadas , Relação Dose-Resposta a Droga , Proteínas Ligadas por GPI/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Hipocampo/química , Hipocampo/efeitos dos fármacos , Potencial da Membrana Mitocondrial , Modelos Biológicos , Neurônios/química , Neurônios/citologia , Neurônios/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Transdução de Sinais , Transdução Genética
8.
Toxicol In Vitro ; 56: 133-140, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30684567

RESUMO

Arsenic is a confirmed human lung carcinogen with estrogenic activity. There are gender differences in the incidence of lung cancer. Estrogen receptors (ER) play an important role in the process of the development of lung cancer. In order to understand the gender difference effects of ER during carcinogenesis of lung induced by arsenic, the effects of arsenic and estrogen receptor antagonist (ICI182780) on expression levels of estrogen receptor beta (ERß), extracellular regulated protein kinase (ERK1/2) and nuclear factor κB (NF-κB/P65) in type II alveolar epithelial cells (AECII) from different sex ICR fetal mice lung were detected. Results showed that arsenic increased the expression levels of mRNA and protein of ERß, ERK1/2 and NF-κB/P65, and ICI182780 inhibited the increase. Furthermore, there remains a gender difference in these changes. To summarize, the observations here strongly suggested that estrogen receptor and its mediated signal pathway molecules might have critical roles of the gender difference of incidence of lung cancer in arsenic induced.


Assuntos
Células Epiteliais Alveolares/efeitos dos fármacos , Arsênio/toxicidade , Disruptores Endócrinos/toxicidade , Receptor beta de Estrogênio/metabolismo , Estrogênios/toxicidade , Células Epiteliais Alveolares/metabolismo , Animais , Células Cultivadas , Receptor beta de Estrogênio/genética , Feminino , Feto , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Camundongos Endogâmicos ICR , NF-kappa B/genética , Caracteres Sexuais
9.
Bioresour Technol ; 260: 413-416, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29655897

RESUMO

This work concerns the adsorption of aromatic organic matter from river water using various doses of a simulated biochar. The water yielded five UV254 peaks associated with organic matters in size exclusion chromatography (SEC), corresponding to molecular weights (MW) of 10,000, 6500, 4800, 3000, and 1500 Da. Biochar removes all of these peaks with an overall adsorption of 6.4 mg-DOC/g-C, and preferentially removes organic matter with high MW. Physisorption control in a pseudo-second-order type model fits the adsorption kinetics. Biochar can therefore be used as an efficient adsorbent of organic matter in water.


Assuntos
Carvão Vegetal , Poluentes Químicos da Água , Adsorção , Cinética , Peso Molecular
11.
Clin Biochem ; 40(1-2): 30-6, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16996047

RESUMO

BACKGROUND: The potential benefits of hyperbaric oxygen therapy (HBOT) have been reported in diabetic patients with foot ulcers. However, the roles of HBOT on wound healing-associated growth factors and inflammatory mediators are not completely understood in diabetes mellitus (DM). OBJECTIVES: The aim of this study was to investigate the effects of HBOT on circulating cytokines, NO, and insulin-like growth factors (IGF) in patients with type 2 DM. DESIGN AND METHODS: Serum samples were collected from patients with type 2 DM (n=31) and healthy subjects (n=29) before (baseline) and after the first and third exposure. RESULTS: Before HBOT, body mass index (BMI) and serum HbA1c were significantly greater, whereas serum IGF-I was significantly lower in diabetic patients compared to healthy subjects (one-way ANOVA, p<0.05). After adjusting for age, gender, and BMI, serum insulin, growth hormone (GH), IGF-II, IGF-binding protein (IGFBP)-1, IGFBP-3, leptin, interleukin (IL)-8, and NO were not significantly altered by HBOT in diabetic patients and healthy subjects (repeated-measures ANOVA). Change in serum insulin (baseline to the third exposure) was a positive predictor of changes in leptin and NO in healthy subjects and diabetic patients, respectively. CONCLUSIONS: Our results suggest that short-term HBOT may not alter the circulating insulin, IGF, leptin, IL-8, and NO levels. In addition, healthy subjects and diabetic patients showed differential responses to HBOT in the relationships of leptin, insulin, and NO. Further studies are needed to clarify the mechanism of HBOT-improved wound healing in diabetic patients with foot ulcers.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/terapia , Oxigenoterapia Hiperbárica/efeitos adversos , Interleucina-8/sangue , Óxido Nítrico/sangue , Somatomedinas/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Índice de Massa Corporal , Feminino , Hemoglobinas Glicadas/análise , Hormônio do Crescimento/sangue , Humanos , Insulina/sangue , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/sangue , Leptina/sangue , Masculino , Pessoa de Meia-Idade , Análise de Regressão
13.
Toxicol Sci ; 121(1): 101-9, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21278055

RESUMO

Arsenic trioxide (ATO) has been effectively used as a therapeutic agent to treat acute promyelocytic leukemia and solid tumors, via induction of cell cycle arrest or apoptosis. In our previous studies, we suggest that c-Jun might act as an adapter to regulate p21(WAF1/CIP1) (p21) expression in response to ATO. Therefore, how to regulate the c-Jun to bind to the p21 promoter was further elucidated. It has been reported that glycogen synthase kinase-3ß (GSK-3ß) can phosphorylate the C-terminus (Ser243) of c-Jun to decrease its protein stability and DNA-binding ability and can also increase the degradation of p21 in resting condition or under ultraviolet irradiation. Therefore, we hypothesized that ATO-induced p21 expression might be through the inhibition of GSK-3ß. Using the DNA affinity precipitation assay, ATO could dephosphorylate the C-terminus (Ser243) of c-Jun to enhance its binding to the p21 promoter and resultant p21 expression. ATO, as well as LiCl (GSK-3ß inhibitor), could induce GSK-3ß(Ser9) phosphorylation and p21 expression in a time- and dose-dependent manner. Constitutively active GSK-3ß, FlagGSKCA, and constitutively inactive GSK-3ß, FlagGSKCI, were constructed to further confirm the involvement of GSK-3ß in the ATO-induced p21 expression. However, the stability of p21 protein was increased by ATO, but not LiCl treatment using cycloheximide. Furthermore, ATO-induced GSK-3ß(Ser9) phosphorylation was through the ERK pathway, but not the PI3K/Akt pathway. We suggest that, taken together, ATO-induced ERK phosphorylation could inhibit GSK-3ß activity to dephosphorylate the C-terminus (Ser243) of c-Jun to increase p21 expression and resultant cell death.


Assuntos
Inibidor de Quinase Dependente de Ciclina p21/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Quinase 3 da Glicogênio Sintase/metabolismo , Óxidos/toxicidade , Trióxido de Arsênio , Arsenicais , Sequência de Bases , Linhagem Celular Tumoral , Primers do DNA , Glicogênio Sintase Quinase 3 beta , Humanos , Imunoprecipitação , Fosforilação , Regiões Promotoras Genéticas
14.
Bioresour Technol ; 102(1): 82-7, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20627550

RESUMO

The Scenedesmus obliquus FSP-3, a species with excellent potential for CO(2) capture and lipid production, was harvested using dispersed ozone flotation. While air aeration does not, ozone produces effective solid-liquid separation through flotation. Ozone dose applied for sufficient algal flotation is similar to those used in practical drinking waterworks. The algae removal rate, surface charge, and hydrophobicity of algal cells, and fluorescence characteristics and proteins and polysaccharides contents of algogenic organic matter (AOM) were determined during ozonation. Proteins released from tightly bound AOM are essential to modifying the hydrophobicity of bubble surfaces for easy cell attachment and to forming a top froth layer for collecting floating cells. Humic substances in the suspension scavenge dosed ozone that adversely affects ozone flotation efficiency of algal cells.


Assuntos
Técnicas de Cultura de Células/métodos , Ozônio/química , Scenedesmus/fisiologia , Ingestão de Líquidos , Fluorescência , Gases/química , Substâncias Húmicas/análise , Interações Hidrofóbicas e Hidrofílicas , Compostos Orgânicos/análise , Polissacarídeos/análise , Proteínas/análise
15.
Bioresour Technol ; 101(23): 9092-6, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20675123

RESUMO

Flotation separation of Chlorella vulgaris, a species with excellent potential for CO(2) capture and lipid production, was studied using dispersed ozone gas. Pure oxygen aeration did not yield flotation. Conversely, applying ozone effectively separation algae from broth through flotation. The ozone dose applied for sufficient algal flotation is <0.05 mg/g biomass, much lower than those used in practical drinking waterworks (0.1-0.3 mg/g suspended solids). Main products, lipid C16:0, was effectively collected in the flotage phase. The algae removal rate, surface charge, and hydrophobicity of algal cells, and proteins and polysaccharides contents of algogenic organic matter (AOM) were determined. Certain quantities of proteins were present in the cultivated algal suspension, hence, minimal quantity of ozone was required to release intracellular proteins as surfactants to lead to effective flotation.


Assuntos
Biotecnologia/métodos , Chlorella vulgaris/efeitos dos fármacos , Ozônio/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/metabolismo , Aderência Bacteriana/efeitos dos fármacos , Hidrocarbonetos/análise , Hidrocarbonetos/farmacologia , Nefelometria e Turbidimetria , Nitrogênio/metabolismo , Polissacarídeos/metabolismo
16.
J Phys Chem B ; 113(47): 15550-7, 2009 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-19921953

RESUMO

We studied the anchoring of 6CB on a series of self-assembled monolayers (SAMs) with a functional group that mimics that of the nematic liquid crystal (LC). The SAMs were first characterized by wetting, Fourier-transform infrared spectroscopy, and surface potential measurements. We found that, in two of these SAMs, the end group dipoles were oriented close to the normal of the surface and that these promoted homeotropic anchoring. In the case of the other SAM, the dipole was oriented parallel to the surface, and planar anchoring was obtained. Raman scattering by adsorbates on thin metal films is enhanced by the electromagnetic fields of surface plasmon polaritons (SPPs). Despite the inherent polarization of SPPs, there have been few reports in which SPP Raman scattering has been used to study molecular orientation. We have developed optical instrumentation to provide efficient excitation and collection of SPP Raman scattered light using attenuated total reflection geometry. The Kretschmann prism coupling configuration was used to excite SPPs on thin (500 A) gold films with adsorbed SAMs of alkanethiols in contact with thin films (50 microm) of the nematic liquid crystal 4'-hexylbiphenyl-4-carbonitrile (6CB, Merck). The anchoring and orientational wetting of the LC 6CB at the interface with omega-functionalized SAMs was studied using this arrangement. In agreement with the results of previous studies, a high-energy surface (-COOH) was found to promote planar anchoring, whereas a low-energy surface (-CF(3)) was found to induce homeotropic anchoring.

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