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1.
Artigo em Inglês | MEDLINE | ID: mdl-38584233

RESUMO

The presence of sulfur-containing compounds in fuel oil has become a major global issue due to their release of toxic sulfur dioxide. Hydrodesulfurization is a commonly used method for removing sulfur from fuel. However, new desulfurization techniques have been developed recently as hydrodesulfurization (HDS) is ineffective in removing refractory sulfur, e.g., BT, DBT, 4-MDBT. In this study, a series of deep eutectic solvent (DES) using ChCl, salicylic acid, oxalic acid, citric acid, and adipic acid as hydrogen bond acceptors and MeOH, EtOH, BuOH, EG, DEG, and TEG as hydrogen bond donors on different mole ratios were synthesized and then investigated the efficiency of these DESs in extracting sulfur from model and diesel fuel. Densities, viscosity, refractive index, and FTIR spectra of synthesized DESs were recorded. It also included oxidative desulfurization, which is a promising approach offering high selectivity, mild reaction conditions, low cost, and high efficiency. Hydrogen peroxide was selected as the oxidant in this study due to its excellent performance, commercial availability, and high proportion of active oxygen. [Citric acid: TEG] [1:7] and [adipic acid: TEG] [1:8] were found to be the most effective, removing up to 44.07% and 42.53% sulfur from model oil during single-stage extraction at 30 °C using a solvent-to-feed ratio of 1.0 and was increased to 86.87% and 85.06% using successive extraction up to the fourth stage. On oxidation, extraction efficiencies were reported to be 98.98%, 87.79%, and 56.25% and 96.96%, 81.22%, and 44.51% for model oil containing DBT and diesel 1 and diesel 2 with DES [citric acid: TEG] [1:7] and [adipic acid: TEG] [1:8] respectively at 30 °C using a solvent-to-feed ratio of 1.0. The study found that [citric acid: TEG] [1:7] exhibits better extraction performance in the deep desulfurization of fuels at an extraction temperature of 30 °C.

2.
Cell Death Dis ; 12(10): 864, 2021 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-34556638

RESUMO

Rewiring of host cytokine networks is a key feature of inflammatory bowel diseases (IBD) such as Crohn's disease (CD). Th1-type cytokines-IFN-γ and TNF-α-occupy critical nodes within these networks and both are associated with disruption of gut epithelial barrier function. This may be due to their ability to synergistically trigger the death of intestinal epithelial cells (IECs) via largely unknown mechanisms. In this study, through unbiased kinome RNAi and drug repurposing screens we identified JAK1/2 kinases as the principal and nonredundant drivers of the synergistic killing of human IECs by IFN-γ/TNF-α. Sensitivity to IFN-γ/TNF-α-mediated synergistic IEC death was retained in primary patient-derived intestinal organoids. Dependence on JAK1/2 was confirmed using genetic loss-of-function studies and JAK inhibitors (JAKinibs). Despite the presence of biochemical features consistent with canonical TNFR1-mediated apoptosis and necroptosis, IFN-γ/TNF-α-induced IEC death was independent of RIPK1/3, ZBP1, MLKL or caspase activity. Instead, it involved sustained activation of JAK1/2-STAT1 signalling, which required a nonenzymatic scaffold function of caspase-8 (CASP8). Further modelling in gut mucosal biopsies revealed an intercorrelated induction of the lethal CASP8-JAK1/2-STAT1 module during ex vivo stimulation of T cells. Functional studies in CD-derived organoids using inhibitors of apoptosis, necroptosis and JAKinibs confirmed the causative role of JAK1/2-STAT1 in cytokine-induced death of primary IECs. Collectively, we demonstrate that TNF-α synergises with IFN-γ to kill IECs via the CASP8-JAK1/2-STAT1 module independently of canonical TNFR1 and cell death signalling. This non-canonical cell death pathway may underpin immunopathology driven by IFN-γ/TNF-α in diverse autoinflammatory diseases such as IBD, and its inhibition may contribute to the therapeutic efficacy of anti-TNFs and JAKinibs.


Assuntos
Caspase 8/metabolismo , Células Epiteliais/patologia , Interferon gama/metabolismo , Intestinos/patologia , Janus Quinase 1/metabolismo , Fator de Transcrição STAT1/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Apoptose , Biópsia , Morte Celular , Linhagem Celular Tumoral , Colo/patologia , Citoproteção , Células Epiteliais/metabolismo , Humanos , Janus Quinase 2/metabolismo , Mitocôndrias/metabolismo , Organoides/patologia , Interferência de RNA , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Transdução de Sinais
3.
Bioelectrochemistry ; 132: 107400, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31812875

RESUMO

An ethanolic extract of Heterophragma adenophyllum (HA) was investigated as a corrosion inhibitor for Fe-C steel in hydrochloric acid. The inhibition effect of the HA extract was examined using weight deterioration, electrochemical impedance spectroscopy (EIS) and polarization techniques. EIS showed enhanced charge transfer resistance with a maximum protection value of ~96% at 600 ppm concentration. Tafel extrapolation results revealed that corrosion was restricted by mixed inhibition. The icorr values reduced considerably from 53.63 µA cm-2 at 100 ppm to 20.11 µA cm-2 at 600 ppm of HA extract. Interaction intensity was further examined through Langmuir, Freundlich, D-R, Frumkin, and Flory-Huggins adsorption isotherms. The computational study, statistical modelling and surface morphology by XPS, AFM, and SEM-EDX, indicated an excellent adsorption capability of HA on Fe-C steel.


Assuntos
Bignoniaceae/metabolismo , Carbono/química , Simulação por Computador , Técnicas Eletroquímicas/métodos , Concentração de Íons de Hidrogênio , Ferro/química , Adsorção , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Simulação de Dinâmica Molecular , Solubilidade , Análise Espectral/métodos , Propriedades de Superfície
4.
Burns Trauma ; 3: 10, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-27574656

RESUMO

BACKGROUND: Regional anaesthesia has been proposed to reduce intraoperative blood loss, duration of hospital stay and in-hospital complications with improved postoperative pain control. General anaesthesia is advantageous for prolonged surgeries. We hypothesized that combined regional and general anaesthesia would offer advantages of both in pelvi-acetabular fracture surgeries. METHODS: We identified 71 patients who underwent open reduction and internal fixation of pelvi-acetabular fractures from May 2012 to 2013 in our trauma centre. We excluded patients with incomplete records (n = 4) and other injuries operated along (n = 8). Hence, 59 patients were divided into three groups: G group (general anaesthesia), R group (regional anaesthesia) and GR group (combined regional and general anaesthesia). Main outcome measurements studied were intraoperative blood loss, duration of hospital stay, duration of surgery and intraoperative and postoperative complications. RESULTS: No differences were obtained in between the groups in terms of age, gender, Injury Severity Score, number of comorbidities, or duration from injury to surgery. No significant differences were found between the three groups for intraoperative blood loss, days of hospital stay and duration of surgery. Intraoperative and postoperative complications were also comparable between the groups (p > 0.05). CONCLUSIONS: There is no specific significant advantage of the technique of anaesthesia on the observed perioperative complications in pelvi-acetabular fracture surgeries.

6.
Dalton Trans ; 42(14): 4994-5003, 2013 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-23389482

RESUMO

Magnetic resonance (MR) imaging is widely used in clinical research to map the structural and functional organization of the brain. We have designed and synthesized a Gd-based specific MR contrast agent that binds to regions in the brain. The presented compound {4-[(4-benzothiazol-2-yl-phenylcarbamoyl)-methyl]-7,10-bis-carboxymethyl-1,4,7,10-tetraazacyclododec-1-yl} acetic acid (DO3A-BT) was synthesized by conjugating the chloroacetylated product of 4-benzothiazol-2-yl-phenylamine with a trisubstituted cyclen. The lanthanide complex (Ln-DO3A-BT) was evaluated in vitro for both MR (Gd-DO3A-BT) and optical (Eu-DO3A-BT) imaging applications. The complex Gd-DO3A-BT displays a relaxivity of r1 = 4.18 mM(-1) s(-1) at 4.7 T which is 1.2 times greater than Dotarem and significantly higher than the brain specific MR contrast agent Luxol Fast Blue (LFB). The protonation constant of the ligand (pKa1 = 9.91, pKa2 = 8.22, pKa3 = 5.01) and the stability constant of the complex formed between Gd(III), Eu(III) and Ca(II) and ligand DO3A-BT (log ßGdL = 18.4, log ßEuL = 18.3, log ßZn2L = 7.1, log ßCa2L = 6.3) were recorded by potentiometric titration. The constants reflect the high stability of the ligand with lanthanides compared with endogenous metal ions. The transmetalation stability of Gd-DO3A-BT toward Zn proved to be excellent with a rate constant of 3.07 × 10(-5) s(-1) which is in line with other tetraazatetraacetic acid (DOTA)-monoamide complexes. The hydration number (q) was found to be 0.92, and is calculated from the difference in the luminescence lifetime of Eu-DO3A-BT in H2O and D2O solutions to determine the coordination state of this complex. The in vivo biodistribution of (99m)Tc-DO3A-BT in BALB/c mice showed a brain uptake of 1.2% ID g(-1) at 2 min post injection when injected with mannitol which disrupts the blood-brain-barrier (BBB) due to osmotic shock. In vitro binding on the brain homogenate revealed a high uptake by the neuronal/glial cells for in vivo applications.


Assuntos
Compostos de Anilina/química , Benzotiazóis/química , Meios de Contraste/síntese química , Complexos de Coordenação/síntese química , Gadolínio/química , Animais , Barreira Hematoencefálica/metabolismo , Encéfalo/diagnóstico por imagem , Meios de Contraste/farmacocinética , Complexos de Coordenação/farmacocinética , Estabilidade de Medicamentos , Compostos Heterocíclicos com 1 Anel/química , Humanos , Imageamento por Ressonância Magnética , Camundongos , Camundongos Endogâmicos BALB C , Cintilografia , Tecnécio/química , Distribuição Tecidual
7.
Expert Opin Drug Deliv ; 10(3): 397-409, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23289421

RESUMO

INTRODUCTION: Gold nanoparticles have been efficiently and effectively used for the delivery of biomolecules and genes along with the potential to offer extremely sensitive diagnostics and imaging methods. AREAS COVERED: This review discusses the historical aspects, synthesis of gold nanoparticles, gold nanoparticles as drug delivery vehicles, photothermal effect of gold nanoparticles and the applications of gold nanoparticles. Gold nanoparticles with their unique optical properties may be useful as biosensors in living cells and has application in the field of drug delivery and photothermal therapy. Depending on the size, shape and degree of aggregation and nature of the protecting organic shells on their surface, gold nanoparticles can appear red, blue and other colors and emit bright resonance light of various wavelengths, which falls under visible region. Because of this property, gold nanoparticles have been extensively used as probes for sensing/imaging a wide range of analysts/targets such as proteins, cells and nucleic acids. EXPERT OPINION: Gold nanoparticles provide an admirable platform for the delivery of biomolecules and genes.


Assuntos
Sistemas de Liberação de Medicamentos , Ouro/química , Nanopartículas/química , Diagnóstico por Imagem/métodos , Humanos , Nanotecnologia
8.
J Anaesthesiol Clin Pharmacol ; 27(1): 74-8, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21804711

RESUMO

BACKGROUND: Laryngeal mask airway is a non invasive supraglottic device which has led to a radical change in the management of modern general anaesthesia. Propofol as a single agent is unsatisfactory and to overcome problems associated with LMA insertions. In the present study, we evaluated the haemodynamic changes and laryngeal mask airway insertion conditions comparing ketamine and opioids as adjuncts to propofol. PATIENTS AND METHODS: 90 patients were randomly divided into 3 groups of 30 each. In Group PK-ketamine 0.5mg kg(-1), in Group PF-fentanyl 1ug kg(-1) and in Group PB - butorphanol 20ug kg(-1) was given intravenously immediately before induction with propofol 2.5 mg kg(-1). Jaw relaxation was assessed according to Young's criteria and the overall conditions according to modified Scheme of Lund and Stovener. RESULTS: The mean total dose of propofol required in Group PK was 160.37 ± 15.75mg, in Group PF 156.22 ± 17.18 mg and in Group PB 140.08 ± 18.97 mg. The incidence of absolute jaw relaxation was highest in Group PB (93.33%) patients, intermediate in Group PF (53.33%) patients and lowest in Group PK i.e. 36.66% patients. Excellent insertion conditions were observed in 12 (40%) patients in Group PK and 13 (43.33%) patients in Group PF and in 26 (86.67%) patients in Group PB. Group PK showed more rise in systolic and diastolic blood pressure and heart rate post LMA insertion as compared to Group PF and Group PB. CONCLUSION: It is concluded that addition of butorphanol to propofol for LMA insertion provided absolute jaw relaxation and excellent insertion conditions with stable haemodynamics Side effects like coughing, gagging, lacrimation and laryngospasm were lower as compared to the other two groups.

9.
Cancer Biother Radiopharm ; 25(5): 571-5, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20874487

RESUMO

The imaging of the distribution of ß-amyloid plaques in the brain is becoming an important diagnostic modality in Alzheimer's disease. The present study reports the synthesis of novel benzothiazole derivatives. The final products were characterized by spectral techniques such as FTIR, (1)H NMR, and electrospray ionization-mass spectrometry. The structure-activity relationship of these benzothiazole derivatives is also reported. The K(i) values of these derivatives were evaluated by competitive binding assay studies. The analogs were labeled with (99m)Tc for the potential diagnostic imaging of Alzheimer's disease using stannous chloride as a reducing agent. The radiochemical stability was found to be ≥ 90% for both the compounds and they were stable for 10-12 hours in human serum. Biodistribution studies of the (99m)Tc complex in normal mice were performed after intravenous injection through the tail vein. The data showed high initial brain uptakes at 2 minutes (2.2% ± 0.1% ID/g), and brain activities washed out to 0.3% ± 0.02% ID/g at 6 hours. In conclusion, benzothiazole derivatives showed excellent binding affinities for ß-amyloid aggregates and high initial brain uptakes in normal mice.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Peptídeos beta-Amiloides/análise , Benzotiazóis/síntese química , Placa Amiloide/diagnóstico por imagem , Compostos Radiofarmacêuticos/síntese química , Animais , Benzotiazóis/farmacocinética , Fluorescência , Humanos , Marcação por Isótopo , Camundongos , Camundongos Endogâmicos BALB C , Relação Quantitativa Estrutura-Atividade , Coelhos , Cintilografia , Compostos Radiofarmacêuticos/farmacocinética , Tecnécio
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