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1.
Environ Monit Assess ; 194(12): 848, 2022 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-36195805

RESUMO

A novel synergistic effect of TiO2 and ZnO incorporation in the PES-based thin-film nanocomposite nanofiltration membranes was developed for the treatment of common effluent treatment plant (CETP) textile wastewater. PES@TiO2 membranes were developed by phase inversion via the immersion precipitation method followed by the addition of zinc oxide nanoparticles prepared by the rapid microwave-assisted hydrothermal process via interfacial polymerization. p-Phenylenediamine was used as a monomer for the IP process that was coated on the PES@TiO2 support layer. Various techniques have been applied to characterize the developed thin-film nanocomposite membranes such as Fourier transform infrared (FTIR) microscopy, field emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), and contact angle measurement to examine the presence of vibrational modes, surface morphology, the crystal structure of nanoparticles, and hydrophilicity of the membrane, respectively. Membrane properties include porosity, salt rejection, mean pore radius, pure water flux, and industrial effluent rejection efficiency that were studied. The thin-film nanocomposite membrane T5-PES@TiO2(2%)-ZnO(0.3%) was prepared with a combination of 17 wt% PES, 78 wt% DMF, 3 wt% PVP K30, 2% TiO2, 2.5 wt% PPD, 0.3 wt% ZnO, and 1.0 wt% TMC that exhibited high water permeability, porosity, higher industrial effluent rejection, and salt rejection efficiency compared to the neat PES membrane.


Assuntos
Nanocompostos , Óxido de Zinco , Monitoramento Ambiental , Membranas Artificiais , Nanocompostos/química , Polímeros/química , Sulfonas , Têxteis , Titânio , Águas Residuárias , Água/química
2.
Cytokine ; 137: 155341, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33128919

RESUMO

The adipokine, leptin exerts inhibitory effect on both spontaneous and oxytocin-induced contractions in myometrium. However, the mechanisms involved in leptin-induced effect are not clear. In the present study, we studied the altered characteristics of uterine contractions in the presence of leptin and the possible mechanisms of its effect in late pregnant (18.5 day) mouse uterus. We conducted functional, biochemical and molecular biology studies to demonstrate the mechanism of leptin-induced response. Leptin exerted an inhibitory response (Emax 40.5 ± 3.99%) on basal uterine contractions. The extent of inhibition was less than that obtained with known uterine relaxants, salbutamol (Emax103 ± 8.66%) and BRL-37344 (Emax 84.79 ± 8.12%). Leptin-induced uterine response was inhibited by leptin receptor antagonist SHLA and JAK-STAT pathway inhibitor, AG-490. The relaxant response was also subdued by NO-cGMP-PK-G pathway blockers L-NAME, 1400W, ODQ and KT-5823. Further, leptin enhanced the levels of NO and cGMP in uterine tissues. Also, SHLA, AG-490 and a combination of 1400 W and L-NAME prevented leptin-induced increase in NO. Similar effect was observed on cGMP levels in presence of leptin and SHLA. However, leptin did not influence CaCl2-induced response in potassium-depolarized tissues. We also detected leptin receptor protein in late pregnant mouse uterus located in endometrial luminal epithelium and myometrial layers. Real-time PCR studies revealed significantly higher expression of short forms of the receptor (ObRa and ObRc) in comparison to the long form (ObRb). In conclusion, the results of the present study suggest that leptin inhibits mouse uterine contraction by stimulating short forms of the leptin receptors and activating NO pathway in a JAK-STAT-dependent manner.


Assuntos
GMP Cíclico/metabolismo , Leptina/farmacologia , Óxido Nítrico/metabolismo , Receptores para Leptina/metabolismo , Contração Uterina/efeitos dos fármacos , Útero/efeitos dos fármacos , Albuterol/farmacologia , Animais , Relação Dose-Resposta a Droga , Etanolaminas/farmacologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Camundongos , Gravidez , Isoformas de Proteínas/agonistas , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Receptores para Leptina/agonistas , Receptores para Leptina/genética , Útero/metabolismo , Útero/fisiologia
3.
Reproduction ; 159(1): 49-58, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31705794

RESUMO

The aim of the present study was to reveal the effect of hyperlipidemia on ß2- and ß3-adrenergic signaling in late pregnant rat uterus. Hyperlipidemia was induced in female Wistar rats by feeding a high-fat high-cholesterol diet for 8 weeks before and after mating upto the 21st day of gestation. The effect of hyperlipidemia on ß-adrenergic signaling was studied with the help of tension experiments, real-time PCR and cAMP ELISA in 21-day pregnant rat uterus. In tension experiments, hyperlipidemia neither altered the spontaneous contractility nor the oxytocin-induced contractions. However, it decreased the -logEC50 values of ß2-adrenoceptor agonist, salbutamol and ß3-adrenoceptor agonist, BRL37344. It also decreased the efficacy of adenylyl cyclase activator, forskolin. Further, there was a significant decrease in salbutamol and BRL37344-stimulated cAMP content in uterine tissues. However, there was no alteration in mRNA expressions of ß2-adrenoceptor (Adrb2), ß3-adrenoceptor (Adrb3) and Gs protein (Gnas) though there was a significant increase in the mRNA expression of Gi protein (Gnai). In conclusion, reduced cAMP content after beta-adrenergic receptor stimulation, which correlates with an increase in Gnai mRNA, may explain the mechanism of the impairment of uterine ß-adrenergic signaling in hyperlipidemic pregnant rats. The clinical implication of the present study may relate to reduced myometrial relaxant response to ß-adrenergic agonists in high fat-induced uterine dysfunction.


Assuntos
AMP Cíclico/metabolismo , Hiperlipidemias/fisiopatologia , Receptores Adrenérgicos beta 2/metabolismo , Receptores Adrenérgicos beta 3/metabolismo , Útero/patologia , Agonistas Adrenérgicos beta/farmacologia , Animais , Feminino , Gravidez , Ratos , Ratos Wistar , Receptores Adrenérgicos beta 2/química , Receptores Adrenérgicos beta 2/genética , Receptores Adrenérgicos beta 3/química , Receptores Adrenérgicos beta 3/genética , Transdução de Sinais , Útero/efeitos dos fármacos , Útero/metabolismo
4.
Sci Rep ; 12(1): 5374, 2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-35354882

RESUMO

This report is on the observation and analysis of nonlinear magnetoelectric effects (NLME) for in-plane currents perpendicularly to the hexagonal axis in single crystals and liquid phase epitaxy grown thin films of barium hexaferrite. Measurements involved tuning of ferromagnetic resonance (FMR) at 56-58 GHz in the multidomain and single domain states in the ferrite by applying a current. Data on the shift in the resonance frequency with input electric power was utilized to estimate the variations in the magnetic parameter that showed a linear dependence on the input electric power. The NLME tensor coefficients were determined form the estimated changes in the magnetization and uniaxial anisotropy field. The estimated NLME coefficients for in-plane currents are shown to be much higher than for currents flowing along the hexagonal axis. Although the frequency shift of FMR was higher for the single domain resonance, the multi-domain configuration is preferable for device applications since it eliminates the need for a large bias magnetic field. Thus, multidomain resonance with current in the basal plane is favorable for use in electrically tunable miniature, ferrite microwave signal processing devices requiring low operating power.

5.
Glycobiology ; 21(9): 1161-72, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21507905

RESUMO

GD3 (CD60a) and its 9-O-acetylated variant (CD60b) are intracellular regulators of apoptosis in T lymphocytes. Surface expressed 9-O-acetyl- and 7-O-acetyl-GD3 (CD60b and CD60c) may have a functional impact on activated T and B cells. In order to investigate the balance between surface and intracellular expression and synthesis and degradation of these glycosphingolipids in human lymphocytes of various differentiation stages, we analyzed (i) expression of GD3 molecules on native T and B cells and thymocytes by flow cytometry and (ii) activity and regulation of possible key enzymes for CD60a,b,c synthesis and degradation at the transcriptional level. Both, surface and cytoplasmic expression of CD60a and CD60c was highest in tonsillar T cells. In thymocytes, CD60c outweighs the other CD60 variants and was mainly found in the cytoplasm. All lymphocyte preparations contained sialate O-acetyltransferase activity producing 7-O-acetyl-GD3. Sialidase activity was highest in peripheral blood lymphocytes followed by thymocytes and tonsillar T and B cells. Transcription of GD3 synthase (ST8SiaI), the key enzyme for GD3 synthesis, was highest in tonsillar T cells, whereas transcriptional levels of sialidase NEU3 and O-acetylesterase H-Lse were lowest in activated T cells. This balance between enzymes of sialic acid metabolism may explain the strong overall staining intensity for all GD3 forms in T cells. Both CASD1, presumably encoding a sialic acid-specific O-acetyltransferase, and H-Lse showed highest transcription in peripheral B lymphocytes corresponding to the low expression of CD60b and c in these cells. Our data point to regulatory functions of these anabolic and catabolic key enzymes for the expression of GD3 and its O-acetylated variants in lymphocytes at a given differentiation stage.


Assuntos
Linfócitos B/metabolismo , Gangliosídeos/metabolismo , Regulação Enzimológica da Expressão Gênica/imunologia , Linfócitos T/metabolismo , Acetilação , Acetilesterase/genética , Acetilesterase/metabolismo , Acetiltransferases/genética , Acetiltransferases/metabolismo , Apoptose/genética , Apoptose/imunologia , Linfócitos B/citologia , Linfócitos B/imunologia , Diferenciação Celular/imunologia , Citosol/metabolismo , Citometria de Fluxo , Gangliosídeos/genética , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Neuraminidase/genética , Neuraminidase/metabolismo , Tonsila Palatina/citologia , Tonsila Palatina/imunologia , Sialiltransferases/genética , Sialiltransferases/metabolismo , Linfócitos T/citologia , Linfócitos T/imunologia , Timo/citologia , Timo/imunologia , Transcrição Gênica
6.
Indian J Tuberc ; 68(4): 457-463, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34752313

RESUMO

BACKGROUND: Drug Resistant Tuberculosis (DR-TB) is an emergent issue in the recent decades. Multidrug resistant (MDR-TB) and Extensive drug resistant (XDR-TB) tuberculosis are the common type of DR-TB. Psychological issues like depression and anxiety are common among the chronic illnesses like tuberculosis. This study aimed at estimating the prevalence of depression and anxiety among these patients. METHODS: Our study is conducted in a tertiary care teaching hospital in North India. This study aimed at identifying the prevalence of depression and anxiety among the drug resistant tuberculosis patients attending DOTS clinic. The depression and anxiety were screened using PHQ-9 and HAM-A inventories. Binomial and multinomial regression analysis were done to identifying the predictors of depression and anxiety. RESULTS: The prevalence rate of depression in MDR-TB and XDR-TB is 68% and 78% respectively. The prevalence of anxiety is 54% in MDR-TB and 66% in XDR-TB respectively in our study. Duration of illness and literacy were the significant predictors of depression and anxiety. CONCLUSION: Patients with DR-TB faces huge psychological burden and this study highlighted the toll of depression and anxiety among them. Adequate screening, identification and treatment for these disorders among DR-TB patients at their earlier treatment stage helps in improving the adherence to treatment and functionality.


Assuntos
Tuberculose Extensivamente Resistente a Medicamentos , Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Antituberculosos/uso terapêutico , Ansiedade/epidemiologia , Depressão/epidemiologia , Tuberculose Extensivamente Resistente a Medicamentos/tratamento farmacológico , Humanos , Índia/epidemiologia , Prevalência , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia
7.
Sci Rep ; 11(1): 8733, 2021 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-33888824

RESUMO

This report is on the observation and theory of electric field E induced non-linear magnetoelectric (NLME) effects in single crystal platelets of ferrimagnetic M-type strontium aluminum hexagonal ferrite. Using microwave measurement techniques, it was found that a DC electric field along the hexagonal c-axis results in significant changes in the saturation magnetization and uniaxial magneto-crystalline anisotropy field and these changes are proportional to the square of the applied static electric field. The NLME effects were present with or without an external bias magnetic field. The E-induced variation in magnetic order parameters is attributed to weakening of magnetic exchange and spin-orbit interactions since conduction electrons in the ferrite are effectively excluded from both interactions while being in transit from one Fe ion to another. We present a phenomenological theory which considers magneto-bielectric effects characterized by a quadratic term in electric field E in the free energy density. The coefficients for the NLME coupling terms have been calculated from experimental data and they do show variations with the Al substitution level and the largest rates of change of the saturation magnetization and anisotropy constant change with the applied power were observed for x = 0.4. It was also clear from the study that strength of the NLME effect does not depend on the amount Al substitution, but critically depends on the electrical conductivity of the sample with the highest NLME coefficients estimated for the sample with the highest conductivity. Results of this work are of importance for a new family of electric field tunable, miniature, high frequency ferrite devices.

8.
J Environ Health Sci Eng ; 19(1): 515-529, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34150255

RESUMO

OBJECTIVE: In this article, monomers (tannic acid (TA) and m- phenylenediamine (MPD)) were used in the fabrication of a novel PES based thin-film composite nanofiltration (TFC-NF) membrane for the treatment of a common effluent treatment plant (CETP) of textile industrial wastewater. MEMBRANE SYNTHESIS: PES support sheets and TFC layers were fabricated via non-solvent induced phase inversion and in-situ interfacial polymerization (IP) process. The ultra-thin active layer was synthesized via the IP process with monomers such as tannic acid (TA) and m- phenylenediamine (MPD). T and M series membranes correspond to (PES/x wt% TA, x = 2, 4, 6) as T1, T2, T3 -TA and (PES/x wt% MPD, x = 2, 4, 6) as M1, M2, M3-MPD respectively. M0 corresponds to PES which is the virgin membrane. RESULTS: The chemical structure, surface morphology, surface roughness and surface properties were explored using fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and contact angle, respectively. The filtration performance of the thin-film composite nanofiltration (TFC-NF) membranes was investigated by various properties like pure water flux, salt rejection, porosity, mean pore radius and antifouling analysis. CONCLUSION: T1-TA membrane showed better water permeability, high salt rejection and better industrial effluent rejection with 94.4% of TDS that are suitable for industrial reuse and agricultural irrigation. Moreover, for T1-TA membrane, the water flux, porosity, mean pore radius, salt rejection, surface roughness and contact angle of 43.5lm- 2 h - 1, 47.1%, 16.7nm, 72.7%, 11.7nm and 41.48°was achieved respectively that was found to be higher than that of all the other fabricated membranes. Further, the rejection efficiency rate of textile effluent characteristics such as pH, turbidity, TDS, alkalinity, total hardness, BOD and COD were also achieved with maximum deduction in the T1-TA TFC-NF membrane compared to the M0-Virgin PES membrane. From the results, it can be confirmed that the T1-TA membrane significantly reduced the alkalinity, total hardness, BOD and COD rejections of 78%, 77.3%, 58.5% and 67.5% respectively, present in the effluent. Water flux recovery ratio (FRR) was improved from 74.6% for M0-Virgin PES membrane to 94.8% for T1-TA membrane. The modified TFC-NF membranes especially T1-TA, had better anti-fouling property and excellent hydrophilicity than the unmodified M0-Virgin PES membrane. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40201-021-00624-x.

9.
J Nanosci Nanotechnol ; 10(9): 6195-9, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21133173

RESUMO

We report the metalorganic chemical vapor deposition of crystalline BiFeO3 films on platinized silicon substrates using n-butylferrocene, triphenylbismuth and oxygen. Based on thermogravimetric analysis data, the suitability of these two precursors for depositing BiFeO3 is discussed. The deposited films were characterized for structure and morphology using X-ray diffraction and scanning electron microscopy. Composition analysis using X-ray photoelectron spectroscopy revealed that the films were stoichiometric BiFeO3. Electrostatic force microscopy indicated that the film had polarizable domains that showed no deterioration in polarization over time long after electric poling. The film showed a saturation magnetization of 10 +/- 1 emu/cm3 at room temperature.

10.
IUCrdata ; 5(Pt 2): x200212, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36340833

RESUMO

The title naphthalene derivative, C24H20O2, features 4-methy-oxy-substituted benzene rings in the 1 and 4 positions of the naphthalene ring system. There are two crystallographically independent mol-ecules (A and B) in asymmetric unit. The independent mol-ecules have very similar conformations in which the naphthalene ring systems are only slightly bent, exhibiting dihedral angles between the constituent benzene rings of 3.76 (15) and 3.39 (15)° for A and B, respectively. The pendent 4-methyoxybenzene rings are splayed out of the plane through the naphthalene ring system to which they are connected [range of dihedral angles = 59.63 (13) to 67.09 (13)°]. In the crystal, the mol-ecular packing is consolidated by inter-molecular C-H⋯π inter-actions, leading to supra-molecular chains along the b axis. The chains assemble without directional inter-actions between them.

11.
Talanta ; 208: 120408, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31816733

RESUMO

A paper-based device (PBD) for the detection of chlorpyrifos pesticide at field application was fabricated based on the principles of enzyme inhibition and image processing. Rhizopus niveus lipase, p-nitrophenol palmitate and Whatman No.1 paper were used as an enzyme, substrate and support matrix, respectively. The performance of functionalized PBD was tested for lateral flow assay reaction in pure water (negative control), artificial pesticide water (positive control) and selected fruits and vegetables wash water (test). The digital image of the PBD after the test was captured using an android smartphone and analyzed in MATLAB software. Different colour space models such as, grey, RGB, HSV and YCbCr were studied and the Cb coordinate was chosen for its higher linearity (R2 = 0.988) with pesticide concentration. Experimental variations such as paper length, relative concentration ratio of the substrate and enzyme were investigated to minimize the product cost and analysis time. The developed PBD showed a significant response over wide range of sample solution's pH and operational temperature. Further, a long-term storage stability was measured for developed PBD. The LOD and LOQ were found to be 0.065 mgL-1 and 0.198 mgL-1. The results obtained from newly developed image processing method showed 92.8% accuracy with microtiter plate assay. Higher MRL was determined in the wash water of cauliflower, grapes, coriander leaves, brinjal and bitter guard. Overall, the developed paper biosensor was precise, cost effective and most suitable for field applications.


Assuntos
Clorpirifos/análise , Contaminação de Alimentos/análise , Processamento de Imagem Assistida por Computador , Resíduos de Praguicidas/análise , Brassica , Coriandrum , Frutas , Lipase/química , Palmitatos/química , Papel , Folhas de Planta , Smartphone , Solanum melongena , Vitis , Água/análise
12.
Glycoconj J ; 26(8): 935-44, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18566887

RESUMO

The O-acetylation of sialic acids is one of the most frequent modifications of these monosaccharides and modulates many cell biological and pathological events. Sialic acid-specific O-acetyltransferases and O-acetylesterases are responsible for the metabolism of esterified sialic acids. Assays were developed for the analysis of the activities and specificities of these enzymes. The methods had to be varied in dependence on the substrate assayed, the kind of biological source, and the state of enzyme purity. With the new techniques the primary site of O-acetyl incorporation at C-7, catalyzed by the animal sialate-O-acetyltransferases studied, was ascertained. Correspondingly, this enzyme, for example from bovine submandibular gland, can be denominated as AcCoA:sialate-7-O-acetyltransferase (EC 2.3.1.45). Methods for assaying the activity of esterases de-O-acetylating sialic acids and their metabolic cooperation with the O-acetyltransferases are presented.


Assuntos
Acetiltransferases/metabolismo , Hidrolases de Éster Carboxílico/metabolismo , Ensaios Enzimáticos/métodos , Acetilação , Acetilesterase , Animais , Bovinos , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Fluorometria , Humanos , Gammainfluenzavirus/enzimologia , Linfócitos/enzimologia , Ácido N-Acetilneuramínico/metabolismo
13.
Glycoconj J ; 26(1): 57-73, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18677580

RESUMO

Previous studies had established an over-expression of 9-O-acetylated sialoglycoproteins (Neu5,9Ac(2)-GPs) on lymphoblasts of childhood acute lymphoblastic leukaemia (ALL). Here, we report the discovery and characterization of sialate-O-acetyltransferase enzyme in ALL-cell lines and lymphoblasts from bone marrow of children diagnosed with B- and T-ALL. We observed a positive correlation between the enhanced sialate-O-acetyltransferase activity and the enhanced expression of Neu5,9Ac(2)-GPs in these lymphoblasts. Sialate-O-acetyltransferase activity in cell lysates or microsomal fractions of lymphoblasts of patients was always higher than that in healthy donors reaching up to 22-fold in microsomes. Additionally, the V (max) of this enzymatic reaction with AcCoA was over threefold higher in microsomal fractions of lymphoblasts. The enzyme bound to the microsomal fractions showed high activity with CMP-N-acetylneuraminic acid, ganglioside GD3 and endogenous sialic acid as substrates. N-acetyl-7-O-acetylneuraminic acid was the main reaction product, as detected by radio-thin-layer chromatography and fluorimetrically coupled radio-high-performance liquid chromatography. CMP and coenzyme A inhibited the microsomal enzyme. Sialate-O-acetyltransferase activity increased at the diagnosis of leukaemia, decreased with clinical remission and sharply increased again in relapsed patients as determined by radiometric-assay. A newly-developed non-radioactive ELISA can quickly detect sialate-O-acetyltransferase, and thus, may become a suitable tool for ALL-monitoring in larger scale. This is the first report on sialate-O-acetyltransferase in ALL being one of the few descriptions of an enzyme of this type in human.


Assuntos
Acetiltransferases/metabolismo , Medula Óssea/enzimologia , Microssomos/enzimologia , Proteínas de Neoplasias/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/enzimologia , Leucemia-Linfoma Linfoblástico de Células T Precursoras/enzimologia , Acetilcoenzima A/metabolismo , Adolescente , Medula Óssea/patologia , Linhagem Celular Tumoral , Criança , Pré-Escolar , Monofosfato de Citidina/metabolismo , Humanos , Lactente , Masculino , Microssomos/patologia , Ácido N-Acetilneuramínico/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia
14.
J Phys Condens Matter ; 21(30): 306004, 2009 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-21828560

RESUMO

Multilayer superlattices consisting of multiferroic Bi(2)NiMnO(6) (BNMO) and La(2)NiMnO(6) (LNMO) have been grown heteroepitaxially on pure and Nb-doped SrTiO(3) substrates using the pulsed laser deposition technique. In a series of superlattice structures grown with a fixed BNMO layer thickness of ten unit cells, we find that the c-axis lattice parameter, Curie temperature and magnetocapacitance are strongly dependent upon the number of stacked LNMO unit cells in the repeating units. The thickness-dependent magnetodielectric effect is attributed to the fluctuations in electric and magnetic dipole ordering due to the substrate and interface induced stress in the superlattice structures. An enhanced magnetodielectric effect in multilayers with LNMO thicknesses larger than six unit cells is explained based on possible canting of spin at the interfaces of LNMO and BNMO.

15.
Phys Rev E ; 97(3-1): 033304, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29776097

RESUMO

Fractures form the main pathways for flow in the subsurface within low-permeability rock. For this reason, accurately predicting flow and transport in fractured systems is vital for improving the performance of subsurface applications. Fracture sizes in these systems can range from millimeters to kilometers. Although modeling flow and transport using the discrete fracture network (DFN) approach is known to be more accurate due to incorporation of the detailed fracture network structure over continuum-based methods, capturing the flow and transport in such a wide range of scales is still computationally intractable. Furthermore, if one has to quantify uncertainty, hundreds of realizations of these DFN models have to be run. To reduce the computational burden, we solve flow and transport on a graph representation of a DFN. We study the accuracy of the graph approach by comparing breakthrough times and tracer particle statistical data between the graph-based and the high-fidelity DFN approaches, for fracture networks with varying number of fractures and degree of heterogeneity. Due to our recent developments in capabilities to perform DFN high-fidelity simulations on fracture networks with large number of fractures, we are in a unique position to perform such a comparison. We show that the graph approach shows a consistent bias with up to an order of magnitude slower breakthrough when compared to the DFN approach. We show that this is due to graph algorithm's underprediction of the pressure gradients across intersections on a given fracture, leading to slower tracer particle speeds between intersections and longer travel times. We present a bias correction methodology to the graph algorithm that reduces the discrepancy between the DFN and graph predictions. We show that with this bias correction, the graph algorithm predictions significantly improve and the results are very accurate. The good accuracy and the low computational cost, with O(10^{4}) times lower times than the DFN, makes the graph algorithm an ideal technique to incorporate in uncertainty quantification methods.

16.
Materials (Basel) ; 10(8)2017 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-28817089

RESUMO

The current surge of interest in multiferroic materials demands specialized measurement techniques to support multiferroics research. In this review article we detail well-established measurement techniques of the magneto-electric coupling coefficient in multiferroic materials, together with newly proposed ones. This work is intended to serve as a reference document for anyone willing to develop experimental measurement techniques of multiferroic materials.

18.
Oncogene ; 18(2): 525-32, 1999 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-9927209

RESUMO

O6-methylguanine-DNA methyltransferase (MGMT), a ubiquitous DNA repair protein, removes the mutagenic DNA adduct O6-alkylguanine, which is synthesized both endogenously and after exposure to alkylnitrosamines and alkylating antitumor drugs such as 2-chloroethyl-N-nitrosourea (CNU). The MGMT gene is highly regulated in mammalian cells and its overexpression, observed in many types of tumor cells, is often associated with cellular resistance to CNU. Dexamethasone, a synthetic glucocorticoid hormone, was found to increase MGMT expression in HeLa S3 cells, concomitant with their increased resistance to CNU. Two putative glucocorticoid responsive elements (GREs) were identified in the human MGMT (hMGMT) promoter. Transient expression of the luciferase reporter gene driven by an hMGMT promoter fragment containing these GREs was activated by dexamethasone. DNase I footprinting assays demonstrated the binding of glucocorticoid receptor to these sequences. In vitro transcription experiment showed that these DNA sequences are functional in glucocorticoid receptor signal-mediated activation of transcription. These results suggest glucocorticoid-mediated induction of the MGMT gene contributes to high level expression of MGMT.


Assuntos
Dexametasona/farmacologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , O(6)-Metilguanina-DNA Metiltransferase/genética , Pegada de DNA , Células HeLa , Humanos , Regiões Promotoras Genéticas , Receptores de Glucocorticoides/genética , Proteínas Recombinantes/genética , Deleção de Sequência
19.
J Am Coll Cardiol ; 33(3): 678-86, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10080468

RESUMO

OBJECTIVES: In this study we determined whether 13N-ammonia uptake measured late after injection provides additional insight into myocardial viability beyond its value as a myocardial blood flow tracer. BACKGROUND: Myocardial accumulation of 13N-ammonia is dependent on both regional blood flow and metabolic trapping. METHODS: Twenty-six patients with chronic coronary artery disease and left ventricular dysfunction underwent prerevascularization 13N-ammonia and 18F-deoxyglucose (FDG) positron emission tomography, and thallium single-photon emission computed tomography. Pre- and postrevascularization wall-motion abnormalities were assessed using gated cardiac magnetic resonance imaging or gated radionuclide angiography. RESULTS: Wall motion improved in 61 of 107 (57%) initially asynergic regions and remained abnormal in 46 after revascularization. Mean absolute myocardial blood flow was significantly higher in regions that improved compared to regions that did not improve after revascularization (0.63+/-0.27 vs. 0.52+/-0.25 ml/min/g, p < 0.04). Similarly, the magnitude of late 13N-ammonia uptake and FDG uptake was significantly higher in regions that improved (90+/-20% and 94+/-25%, respectively) compared to regions that did not improve after revascularization (67+/-24% and 71+/-25%, p < 0.001 for both, respectively). However, late 13N-ammonia uptake was a significantly better predictor of functional improvement after revascularization (area under the receiver operating characteristic [ROC] curve = 0.79) when compared to absolute blood flow (area under the ROC curve = 0.63, p < 0.05). In addition, there was a linear relationship between late 13N-ammonia uptake and FDG uptake (r = 0.68, p < 0.001) as well as thallium uptake (r = 0.76, p < 0.001) in all asynergic regions. CONCLUSIONS: These data suggest that beyond its value as a perfusion tracer, late 13N-ammonia uptake provides useful information regarding functional recovery after revascularization. The parallel relationship among 13N-ammonia, FDG, and thallium uptake supports the concept that uptake of 13N-ammonia as measured from the late images may provide important insight regarding cell membrane integrity and myocardial viability.


Assuntos
Amônia , Circulação Coronária , Doença das Coronárias/fisiopatologia , Revascularização Miocárdica , Disfunção Ventricular Esquerda/fisiopatologia , Adulto , Idoso , Amônia/farmacocinética , Velocidade do Fluxo Sanguíneo , Doença das Coronárias/metabolismo , Doença das Coronárias/cirurgia , Feminino , Fluordesoxiglucose F18/farmacocinética , Imagem do Acúmulo Cardíaco de Comporta , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Radioisótopos de Nitrogênio/farmacocinética , Curva ROC , Volume Sistólico/fisiologia , Radioisótopos de Tálio/farmacocinética , Tomografia Computadorizada de Emissão , Tomografia Computadorizada de Emissão de Fóton Único , Resultado do Tratamento , Disfunção Ventricular Esquerda/metabolismo , Disfunção Ventricular Esquerda/cirurgia
20.
Br J Ophthalmol ; 89(10): 1241-4, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16170108

RESUMO

AIM: To ascertain utility values and associated quality of life with different severity and duration of glaucoma among Indian patients. METHODS: Utility values of 105 consecutive patients with primary glaucoma of at least 12 months' duration were evaluated in a cross sectional study. Utility values were ascertained in five groups using both the time-trade off and standard gamble methods: group 1 (best corrected visual acuity in the better eye of 6/9 or better), group 2 (best corrected visual acuity in the better eye of 6/18 to 6/12), group 3 (best corrected visual acuity in the better eye of 6/36 to6/24), group 4 (best corrected visual acuity in the better eye of 3/60 to 6/60), and group 5 (best corrected visual acuity in the better eye of 3/60 or worse). RESULTS: The mean utility value for the glaucoma group as a whole was 0.64 (SD 0.69; 95% confidence interval (CI), 0.58 to 0.70) with the time-trade off method and 0.86 (SD 1.00; 95% CI, 0.81 to 0.90) with the standard gamble method for a gamble of death and 0.97 (SD 1.00; 95% CI, 0.94 to 0.99) for a gamble of blindness. The mean utility results by the time-trade off method were as follows: group 1 = 0.66, group 2 = 0.66, group 3 = 0.62, group 4 = 0.55, and group 5 = 0.61. The utility value was much lower (0.46) in those with no formal education or only primary education compared to those with postgraduate education (0.75) (p = 0.038). Those patients with glaucoma of less than 5 years' duration had a utility score of 0.62 while those with glaucoma for more than 10 years had a score of 0.74 (p = 0.40). CONCLUSIONS: Visual acuity loss occurring secondary to glaucoma is associated with a substantial decrease in patient utility value (and quality of life) in a developing country like India. The utility value is directly dependent on the degree of visual acuity loss associated with the disease and educational status and not on the duration of disease, the number of medications, or the visual field indices.


Assuntos
Glaucoma/psicologia , Indicadores Básicos de Saúde , Qualidade de Vida , Adulto , Idoso , Estudos Transversais , Países em Desenvolvimento , Feminino , Glaucoma/fisiopatologia , Glaucoma/reabilitação , Humanos , Índia , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Participação do Paciente/métodos , Anos de Vida Ajustados por Qualidade de Vida , Acuidade Visual
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