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1.
Abdom Radiol (NY) ; 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38831075

RESUMO

OBJECTIVE: To investigate the feasibility and accuracy of predicting locoregional recurrence (LR) in elderly patients with esophageal squamous cell cancer (ESCC) who underwent radical radiotherapy using a pairwise machine learning algorithm. METHODS: The 130 datasets enrolled were randomly divided into a training set and a testing set in a 7:3 ratio. Clinical factors were included and radiomics features were extracted from pretreatment CT scans using pyradiomics-based software, and a pairwise naive Bayes (NB) model was developed. The performance of the model was evaluated using receiver operating characteristic (ROC) curves and decision curve analysis (DCA). To facilitate practical application, we attempted to construct an automated esophageal cancer diagnosis system based on trained models. RESULTS: To the follow-up date, 64 patients (49.23%) had experienced LR. Ten radiomics features and two clinical factors were selected for modeling. The model demonstrated good prediction performance, with area under the ROC curve of 0.903 (0.829-0.958) for the training cohort and 0.944 (0.849-1.000) for the testing cohort. The corresponding accuracies were 0.852 and 0.914, respectively. Calibration curves showed good agreement, and DCA curve confirmed the clinical validity of the model. The model accurately predicted LR in elderly patients, with a positive predictive value of 85.71% for the testing cohort. CONCLUSIONS: The pairwise NB model, based on pre-treatment enhanced chest CT-based radiomics and clinical factors, can accurately predict LR in elderly patients with ESCC. The esophageal cancer automated diagnostic system embedded with the pairwise NB model holds significant potential for application in clinical practice.

2.
J Am Chem Soc ; 145(16): 8751-8756, 2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-36943737

RESUMO

This study describes an instantaneously gas-induced dynamic transition of an industrial Cu/ZnO/Al2O3 catalyst. Cu/ZnO clusters become "alive" and lead to a promotion in reaction rate by almost one magnitude, in response to the variation of the reactant components. The promotional changes are functions of either CO2-to-CO or H2O-to-H2 ratio which determines the oxygen chemical potential thus drives Cu/ZnO clusters to undergo reconstruction and allows the maximum formation of Cu-Zn2+ sites for CH3OH synthesis.

3.
Angew Chem Int Ed Engl ; 58(27): 9083-9087, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31074080

RESUMO

The commercial high-temperature water-gas shift (HT-WGS) catalyst consists of CuO-Cr2 O3 -Fe2 O3 , where Cu functions as a chemical promoter to increase the catalytic activity, but its promotion mechanism is poorly understood. In this work, a series of iron-based model catalysts were investigated with in situ or pseudo in situ characterization, steady-state WGS reaction, and density function theory (DFT) calculations. For the first time, a strong metal-support interaction (SMSI) between Cu and FeOx was directly observed. During the WGS reaction, a thin FeOx overlayer migrates onto the metallic Cu particles, creating a hybrid surface structure with Cu-FeOx interfaces. The synergistic interaction between Cu and FeOx not only stabilizes the Cu clusters, but also provides new catalytic active sites that facilitate CO adsorption, H2 O dissociation, and WGS reaction. These new fundamental insights can potentially guide the rational design of improved iron-based HT-WGS catalysts.

4.
Basic Clin Pharmacol Toxicol ; 123(6): 670-677, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29924913

RESUMO

Chemotherapy is one of the most effective forms of cancer treatment. It has been widely used in the treatment of various malignant tumours. To investigate molecular mechanisms responsible for the chemoresistance of anaplastic thyroid cancer (ATC), we established the doxorubicin (Dox) resistance of human ATC SW1736 and 8305C cells and named them SW1736/Dox and 8305C/Dox, respectively. We evaluated the expression of various micro-RNAs (miRNAs) between control and Dox-resistant ATC cells and found that the expression of miR-27b-3p was significantly increased in Dox-resistant ATC cells. Targeted inhibition of miR-27b can increase the sensitivity of SW1736/Dox and 8305C/Dox cells. Bioinformatics analysis revealed that miR-27b can directly target peroxisome proliferator-activated receptor gamma (PPARγ) within the 3' untranslated region (UTR). This was proved by the results that miR-27b-3p down-regulated the protein and mRNA levels of PPARγ. While the mutant in the core binding sites of PPARγ abolished miR-27b-3p-induced down-regulation of luciferase activity. Over-expression of PPARγ can increase the Dox sensitivity of SW1736/Dox and 8305C/Dox cells. Basic fibroblast growth factor (bFGF) might be involved in miR-27b-3p/PPARγ-regulated Dox resistance of ATC cells. The activation of p65 nuclear factor-κB (NF-κB) regulated the up-regulation of miR-27b-3p in Dox-resistant ATC cells. Collectively, our data revealed that miR-27b-3p/PPARγ is involved in the Dox resistance of human ATC cells. It suggested that targeted inhibition of miR-27b-3p might be helpful to overcome the drug resistance of ATC cells.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Doxorrubicina/farmacologia , MicroRNAs/fisiologia , PPAR gama/efeitos dos fármacos , Carcinoma Anaplásico da Tireoide/dietoterapia , Neoplasias da Glândula Tireoide/tratamento farmacológico , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , MicroRNAs/genética , PPAR gama/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Regulação para Cima/efeitos dos fármacos , Áreas Alagadas
5.
Antonie Van Leeuwenhoek ; 111(4): 485-491, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29134394

RESUMO

A Gram-stain negative, aerobic, motile and ovoid- to rod-shaped bacteria strain, designated XC0140T, was isolated from soil samples near the sewage treatment tank of a chemical factory in Zhejiang Province, China, and subjected to polyphasic taxonomic investigation. Strain XC0140T grew at 10-37 °C and pH 6.0-9.0 (optimum, 35 °C and pH 7.5) and with 0-17% (w/v) NaCl (optimum, 1%). According to phylogenetic analysis based on 16S rRNA gene sequences, strain XC0140T was assigned to the genus Pararhizobium with high 16S rRNA gene sequence similarity of 95.97% to "Pararhizobium helanshanense CCNWQTX14T", followed by Pararhizobium sphaerophysae CCNWGS0238T (95.95%). Chemotaxonomic analysis showed that strain XC0140T contains ubiquinone-10 as the predominant respiratory quinone and possessed summed feature 8 (comprising C18: 1 ω7c and/or ω6c), 11-methyl C18:1 ω7c, C18: 0 and C16: 0 as predominant forms of fatty acids. The polar lipids of strain XC0140T consisted of seven phospholipids (PL), two aminolipids (AL), one glycolipid (GL) and three unidentified lipids (L1, L2 and L3). The DNA G+C content was 62.7 mol%. Based on the polyphasic taxonomic characterization, strain XC0140T is considered to represent a novel species of the genus Pararhizobium, for which the name Pararhizobium haloflavum sp. nov. is proposed. (type strain XC0140T = MCCC 1K03228T = KCTC 52582T).


Assuntos
Filogenia , Rhizobiaceae/classificação , Microbiologia do Solo , Aerobiose , Composição de Bases , China , Ácidos Graxos/análise , Genes Bacterianos/genética , Genoma Bacteriano/genética , Glicolipídeos/análise , Concentração de Íons de Hidrogênio , Fosfolipídeos/análise , RNA Ribossômico 16S/genética , Rhizobiaceae/química , Rhizobiaceae/genética , Esgotos/microbiologia , Cloreto de Sódio , Especificidade da Espécie , Ubiquinona
6.
Oncol Rep ; 38(5): 3085-3093, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28901486

RESUMO

The function of miRNA­148a in lymphatic metastases of papillary thyroid cancer and its mechanism were tested. In this investigation, miRNA­148a expression of lymphatic metastases of papillary thyroid cancer patients was inhibited, compared with normal group. We found that miRNA­148a overexpression was effectively reduced cell cell proliferation and metastases, and induced apoptosis of papillary thyroid cancer in vitro. Overexpression of miRNA­148a significantly induced Bax protein expression and caspase­3/9 levels, and suppressed phosphorylation STAT3 (p­STAT3), PI3K and p­Akt protein expression of papillary thyroid cancer in vitro. Next, si­STAT3, could inhibit p­STAT3 protein expression, reducing cell-cell proliferation and metastases, and inducing apoptosis of papillary thyroid cancer following miRNA­148a overexpression. Then, the PI3K inhibitor was able to inhibit PI3K and p­Akt protein expression, reduced cell cell proliferation and metastases, and induced apoptosis of papillary thyroid cancer following miRNA­148a overexpression. Taken together, our results suggest that miRNA­148a inhibits lymphatic metastases of papillary thyroid cancer through STAT3 and PI3K/AKT signaling pathways.


Assuntos
Carcinoma Papilar/genética , MicroRNAs/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fator de Transcrição STAT3/genética , Neoplasias da Glândula Tireoide/genética , Carcinoma Papilar/metabolismo , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Metástase Linfática , Fosforilação , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Câncer Papilífero da Tireoide , Neoplasias da Glândula Tireoide/metabolismo
7.
CNS Neurosci Ther ; 21(12): 953-61, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26507365

RESUMO

AIMS: Fibrillar aggregates of ß-amyloid protein (Aß) are the main constituent of senile plaques and considered to be one of the causative events in the pathogenesis of Alzheimer's disease (AD). Compounds that could inhibit Aß fibrils formation, disaggregate preformed Aß fibrils as well as reduce their associated neurotoxicity might have therapeutic values for treating AD. In this study, the inhibitory effects of bis (heptyl)-cognitin (B7C), a multifunctional dimer derived from tacrine, on aggregation and neurotoxicity of Aß1-40 were evaluated both in vitro and in vivo. METHODS: Thioflavin T fluorescence assay was carried out to evaluate Aß aggregation, MTT and Hoechst-staining assays were performed to investigate Aß-associated neurotoxicity. Fluorescent probe DCFH-DA was used to estimate the accumulation of intracellular reactive oxygen stress (ROS). Morris water maze was applied to determine learning and memory deficits induced by intracerebroventricular infusion of Aß in rats. RESULTS: B7C (0.1-10 µM), but not tacrine, effectively inhibited Aß fibrils formation and disaggregated preformed Aß fibrils following co-incubation of B7C and Aß monomers or preformed fibrils, respectively. In addition, B7C markedly reduced Aß fibrils-associated neurotoxicity in SH-SY5Y cell line, as evidenced by the increase in cell survival, the decrease in Hoechst-stained nuclei and in intracellular ROS. Most encouragingly, B7C (0.1 and 0.2 mg/kg), 10 times more potently than tacrine (1 and 2 mg/kg), inhibited memory impairments after intracerebroventricular infusion of Aß in rats, as evidenced by the decrease in escape latency and the increase in the spatial bias in Morris water maze test along with upregulation of choline acetyltransferase activity and downregulation of acetylcholinesterase activity. CONCLUSION: These findings provide not only novel molecular insight into the potential application of B7C in treating AD, but also an effective approach for screening anti-AD agents.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/toxicidade , Amiloide/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/toxicidade , Tacrina/análogos & derivados , Doença de Alzheimer/patologia , Doença de Alzheimer/fisiopatologia , Amiloide/metabolismo , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Humanos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/fisiopatologia , Fármacos Neuroprotetores/química , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Tacrina/química , Tacrina/farmacologia
8.
J Mol Neurosci ; 56(4): 977-987, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25982925

RESUMO

Neurodegenerative disorders are one of the leading causes of death among the elderly. Therapeutic approaches with a single target have proven unsuccessful in treating these diseases. Structural combination of multi-functional compounds may lead to a molecule with multiple properties. In this study, we designed and synthesized T-006, a novel analog derived from two multi-functional neuroprotective chemicals, tetramethylpyrazine and J147. The methoxyphenyl group of J147 was replaced by tetramethylpyrazine. Bioactivity evaluation showed that T-006 at very low concentrations had multi-functional neuroprotective effects including rescuing iodoacetic acid-induced neuronal loss, preventing oxidative stress-induced neurotoxicity and reducing glutamate-induced excitotoxicity in vitro. Most importantly, T-006 significantly ameliorated memory impairments in APP/PS1 transgenic mice. These multiple functions of a single molecule suggest that T-006 is a promising novel neuroprotective agent for treating various neurodegenerative disorders, including and in particular Alzheimer's disease.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Antioxidantes/farmacologia , Hidrazonas/farmacologia , Fármacos Neuroprotetores/farmacologia , Pirazinas/farmacologia , Animais , Antioxidantes/síntese química , Antioxidantes/uso terapêutico , Células Cultivadas , Hidrazonas/síntese química , Camundongos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/uso terapêutico , Células PC12 , Pirazinas/síntese química , Pirazinas/química , Ratos , Ratos Sprague-Dawley
9.
CNS Neurosci Ther ; 21(1): 61-70, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25310912

RESUMO

AIM: Nerve growth factor (NGF) regulates neuronal survival and differentiation by activating extracellular signal-regulated-kinases (ERK) 1/2 and phosphoinositide-3-kinase (PI3K)/Akt pathways in two distinct processes: latency process and neurite extension process. This study was designed to investigate whether botanical drug C-glucosylated isoflavone puerarin coordinates with NGF to regulate neuritogenesis via activating ERK1/2 and PI3K/Akt in neurite extension process. METHODS: We investigated the neuroprotective and neurotrophic activities of puerarin in MPTP-lesioned mice and dopaminergic PC12 cells. The effects of puerarin on ERK1/2, Akt, Nrf2, and HO-1 were assessed by Western blotting. The neurite outgrowth was assayed by neurite outgrowth staining kit. RESULTS: Puerarin protected dopaminergic cells and ameliorated the behavioral impairments in MPTP-lesioned mice. Puerarin potentiated the effect of NGF on neuritogenesis in PC12 cells by >10-fold. Mechanistic studies revealed: (1) puerarin rapidly activated ERK1/2 and Akt, leading to the activation of Nrf2/heme oxygenase-1 (HO-1) pathways; (2) ERK1/2, PI3K/Akt, and HO-1 inhibitors attenuated the neuritogenic activity of puerarin. Notably, puerarin enhanced NGF-induced neuritogenesis in a timing-dependent manner. CONCLUSION: Puerarin effectively coordinated with NGF to stimulate neuritogenesis via activating ERK1/2 and PI3K/Akt pathways in neurite extension process. These results demonstrated a general mechanism supporting the therapeutic application of puerarin-related compounds in neurodegenerative diseases.


Assuntos
Isoflavonas/farmacologia , Neuritos/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Animais , Crescimento Celular , Sobrevivência Celular/efeitos dos fármacos , Heme Oxigenase-1/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fator de Crescimento Neural/metabolismo , Neuritos/fisiologia , Neurogênese/fisiologia , Neurônios/fisiologia , Células PC12 , Fosfatidilinositol 3-Quinases/metabolismo , Distribuição Aleatória , Ratos
10.
Neurochem Int ; 78: 76-85, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25217805

RESUMO

INTRODUCTION: The natural product tetramethylpyrazine (TMP) has a variety of biologic activities, including neuroprotection. Nitrones are powerful free radical scavengers. We have designed and synthesized a TMP derivative, TN-2, which is armed with two nitrone moieties. AIMS: In this study, we investigated the neuroprotective effect of TN-2 against 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in vitro and in zebrafish. METHODS: PC12 cells, zebrafish and rats were exposed to 6-OHDA challenge. MTT assay, LDH release, Hoechst staining, DAF-FM staining, luciferase reporter construct transfection, and western blotting were applied to detect cell viability, apoptosis, intracellular nitric oxide (NO), NF-κB transcriptional activity and proteins expression. In zebrafish, whole-mount staining and real-time PCR were performed to quantify dopaminergic neurons and mRNA expression. Hematoxylin and eosin staining and immunohistochemistry for glial fibrillary acidic protein were used to detect the astrocyte activation in the unilateral 6-OHDA rat model. RESULTS: TN-2 but not TMP exhibited potent neuroprotective effect against 6-OHDA-induced apoptosis in PC12 cells. Moreover, TN-2 prevented dopaminergic neuron loss and suppressed mRNA expression of pro-inflammatory genes, including IL-1ß, TNF-α and COX-2, in 6-OHDA-treated zebrafish. TN-2 remarkably attenuated microglial/astrocyte activation in the unilateral 6-OHDA rat model. The mechanistic study demonstrated that TN-2 inhibited over-production of intracellular NO and protein expression of inducible nitric oxide synthase through down-regulating NF-κB activity. Additionally, the PKCα/PI3-K/Akt pathway was also involved in the neuroprotection of TN-2. CONCLUSION: These results suggest that TN-2 protected against 6-OHDA-induced neurotoxicity via modulating the NF-κB-medicated neuroinflammation and PKCα/PI3-K/Akt pathways.


Assuntos
NF-kappa B/fisiologia , Oxidopamina/toxicidade , Fosfatidilinositol 3-Quinases/fisiologia , Proteína Quinase C-alfa/fisiologia , Proteínas Proto-Oncogênicas c-akt/fisiologia , Pirazinas/farmacologia , Animais , Masculino , Fármacos Neuroprotetores/farmacologia , Células PC12 , Pirazinas/química , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Peixe-Zebra
11.
CNS Neurosci Ther ; 20(3): 244-52, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24393200

RESUMO

BACKGROUND: Sunitinib is an inhibitor of the multiple receptor tyrosine kinases (RTKs) for cancer therapy. Some sunitinib analogues could prevent neuronal death induced by various neurotoxins. However, the neuroprotective effects of sunitinib have not been reported. METHODS: Cerebellar granule neurons (CGNs) and SH-SY5Y cells were exposed to low-potassium and MPP(+) challenges, respectively. MTT assay, FDA/PI staining, Hoechst staining, DAF-FM, colorimetric nitric oxide synthase (NOS) activity assay, and Western blotting were applied to detect cell viability, NO production, NOS activity, and neuronal NOS (nNOS) expression. Short hairpin RNA was used to decrease nNOS expression. In vitro NOS enzyme activity assay was used to determine the direct inhibition of nNOS by sunitinib. RESULTS: Sunitinib prevented low-potassium-induced neuronal apoptosis in CGNs and MPP(+) -induced neuronal death in SH-SY5Y cells. However, PTK787, another RTK inhibitor, failed to decrease neurotoxicity in the same models. Sunitinib reversed the increase in NO levels, NOS activity, and nNOS expression induced by low potassium or MPP(+) . Knockdown of nNOS expression partially abolished the neuroprotective effects of sunitinib. Moreover, sunitinib directly inhibited nNOS enzyme activity. CONCLUSIONS: Sunitinib exerts its neuroprotective effects by inhibiting NO overproduction, possibly via the inhibition of nNOS activity and the decrease in nNOS expression.


Assuntos
Indóis/farmacologia , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Óxido Nítrico/metabolismo , Pirróis/farmacologia , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Animais , Animais Recém-Nascidos , Apoptose/efeitos dos fármacos , Células Cultivadas , Cerebelo/citologia , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Indazóis/farmacologia , Neurotoxinas/toxicidade , Ratos , Ratos Sprague-Dawley , Sunitinibe , ômega-N-Metilarginina/farmacologia
12.
J Am Chem Soc ; 135(43): 16058-61, 2013 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-24124647

RESUMO

An iron oxychloride (FeOCl) catalyst was developed for oxidative degradation of persistent organic compounds in aqueous solutions. Exceptionally high activity for the production of hydroxyl radical (OH·) by H2O2 decomposition was achieved, being 2-4 orders of magnitudes greater than that over other Fe-based heterogeneous catalysts. The relationship of catalyst structure and performance has been established by using multitechniques, such as XRD, HRTEM, and EPR. The unique structural configuration of iron atoms and the reducible electronic properties of FeOCl are responsible for the excellent activity. This study paves the way toward the rational design of relevant catalysts for applications, such as wastewater treatment, soil remediation, and other emerging environmental problems.


Assuntos
Poluentes Ambientais/química , Peróxido de Hidrogênio/química , Radical Hidroxila/química , Compostos de Ferro/química , Ferro/química , Compostos Orgânicos/química , Catálise , Compostos Férricos , Filtração , Concentração de Íons de Hidrogênio , Cinética , Espécies Reativas de Oxigênio , Difração de Raios X
13.
Biopharm Drug Dispos ; 32(3): 140-50, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21271607

RESUMO

The objective of the present study was to elucidate the mechanisms of intestinal transport of bis(12)-hupyridone (B12H) to predict its oral bioavailability. The effect of the B12H concentration and the contribution of the drug efflux transporters, P-glycoprotein (P-gp or ABCB1) and multidrug resistance-associated proteins (MRPs or ABCC) on B12H absorption were measured and evaluated using the human intestinal epithelial Caco-2 cell monolayer in the presence of transporter inhibitors. The results indicated that B12H was absorbed in a dose-dependent manner at concentrations ranging from 132 to 264 µM. However, only apical efflux was observed in the directional transport studies for B12H below 88 µM (P(app) (AP-to-BL): virtually zero; P(app) (BL-to-AP): 1.591 ± 0.071 × 10(-5) cm s(-1) ). P-gp and mixed P-gp/MRP inhibitors significantly increased the absorptive transport (P(app) (AP-to-BL)) to 0.619 ± 0.018 × 10(-5) and 0.608 ± 0.025 × 10(-5) cm s(-1) , respectively, while decreasing secretory transport (P(app) (BL-to-AP)) by >75%. A multiple-MRP inhibitor, probenecid, increased the P(app) (AP-to-BL) to 0.329 ± 0.015 × 10(-5) cm s(-1) while decreasing the P(app) (BL-to-AP) by 50%. Another multiple-MRP inhibitor, indomethacin, only modestly decreased the P(app) (BL-to-AP) by ∼30% and had no effect on the absorptive transport (P(app) (AP-to-BL): virtually zero). In addition, the effect of various pharmaceutical excipients (e.g. Pluronic F-68, Tween-80 and Brij-35) on B12H transport was determined and compared. Among them, Brij-35 effectively enhanced B12H absorption at a concentration lower than its critical micelle concentration (CMC, 60 µM). Therefore, Brij-35 can be used as a potential enhancer to improve intestinal absorption of B12H for oral administration.


Assuntos
Polietilenoglicóis/metabolismo , Quinolonas/metabolismo , Tensoativos/metabolismo , Transporte Biológico/fisiologia , Células CACO-2 , Células Epiteliais/metabolismo , Humanos , Mucosa Intestinal/citologia , Mucosa Intestinal/metabolismo , Estrutura Molecular , Polietilenoglicóis/química , Quinolonas/química , Tensoativos/química
14.
J Am Chem Soc ; 132(38): 13172-3, 2010 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-20815345

RESUMO

The excellent performance of hydroxyapatite, a novel non-precious metal catalyst, for formaldehyde (HCHO) combustion at room temperature is reported. Temperature-programmed surface reaction results indicated that hydroxyl groups bonded with the channel Ca(2+) may be responsible for adsorption/activation of HCHO.


Assuntos
Durapatita/química , Formaldeído/química , Catálise , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Temperatura
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