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1.
Chemosphere ; 362: 142456, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38878982

RESUMO

The ecologically friendly properties, low-cost, and readily available titanium dioxide (TiO2) materials have made them a subject of considerable interest for numerous promising applications. Anatase TiO2 nanoparticles were synthesized in the current study through the utilization of a hibiscus leaf extract and the advent of TiO2-doped g-C3N4(TiCN) nanocomposites (varying 0.5 mM, 1.0 mM, 1.5 mM, and 2.0 mM) by thermal polymerization. Here, the proposed study utilized multiple analytical techniques, including UV-Vis spectroscopy, a diffraction pattern (XRD), SEM coupled with EDX analysis, TGA, and EPR, to characterize the as-prepared TiO2 nanoparticles and TiCN nanocomposites. BET analysis the adsorption-desorption isotherms of the TiCN(1.5 mM) nanocomposite, the surface area of the prepared nanocomposite is 112.287 m2/g, and the pore size is 7.056 nm. The XPS spectra support the development of the TiCN(1.5 mM) nanocomposite by demonstrating the presence of C and N elements in the nanocomposite in addition to TiO2. HRTEM images where the formation of stacked that indicates a planar, wrinkled graphitic-like structure is clearly visible. The TiCN (1.5 mM) specimen exhibited enhanced morphology, enhanced surface area, greater capacity to take in visible light, and lowered band gap when compared to g-C3N4 following z-scheme heterojunction. The sample denoted as TiCN (1.5 mM) exhibited superior performance in terms of adsorption and photocatalytic activity using rhodamine B and Bisphenol A. Furthermore, the TiCN (1.5 mM) composite exhibited satisfactory stability over four cyclic runs, indicating its potential application in minimizing the impact of organic wastewater contaminants when compared to g-C3N4.

2.
ACS Appl Mater Interfaces ; 14(37): 42628-42634, 2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36082439

RESUMO

In this study, we used a new series of highly polar three-ring-based bent-core liquid crystals (BCLCs) to stabilize a wide temperature range of blue phase III (BPIII), including room temperature. A significant finding is the implementation of electro-optical (E-O) switching at room temperature in the current BPIII system. The observed Kerr constant (K) has an extraordinarily high value (K ≈ 9.2 × 10-9m V-2) that exceeds all previously reported values in the category of BPIII materials. The extremely high value of K realizes the lowest operating voltage (Von ≈ 3.3 Vrms/µm) for BPIII. The measured values of K and Von in BPIII set a new limit for the experimentalist. The millisecond (ms) order response times are explained based on rotational viscosity. The present binary system of BPIII materials is an excellent choice for device application.

3.
Braz J Med Biol Res ; 54(10): e11391, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34406209

RESUMO

Nonalcoholic fatty liver disease (NAFLD), characterized by hepatosteatosis and steatohepatitis, is intrinsically related to obesity. Our previous study reported on the anti-obese activity of α,ß-amyrin (AMY), a pentacyclic triterpene isolated from Protium heptaphyllum. This study investigated its ability to prevent fatty liver and the underlying mechanism using the mouse model of NAFLD. NAFLD was induced in male Swiss mice fed a high fat diet (HFD) for 15 weeks. The controls were fed a normal chow diet (ND). The mice were simultaneously treated with AMY at 10 and 20 mg/kg or fenofibrate at 50 mg/kg. Lipid levels along with metabolic and inflammatory parameters were assessed in liver and serum. The liver sections were histologically examined using H&E staining. RT-qPCR and western blotting assays were performed to analyze signaling mechanisms. Mice fed HFD developed severe hepatic steatosis with elevated triglycerides and lipid droplets compared with ND controls. This was associated with a decrease in AMP-activated protein kinase (AMPK) activity, an increase of mechanistic target of rapamycin complex 1 (mTORC1) signaling, and enhanced sterol regulatory element binding protein 1 (SREBP1) expression, which have roles in lipogenesis, inhibition of lipolysis, and inflammatory response. AMY treatment reversed these signaling activities and decreased the severity of hepatic steatosis and inflammatory response, evidenced by serum and liver parameters as well as histological findings. AMY-induced reduction in hepatic steatosis seemed to involve AMPK-mTORC1-SREBP1 signaling pathways, which supported its beneficial role in the prevention and treatment of NAFLD.


Assuntos
Resistência à Insulina , Hepatopatia Gordurosa não Alcoólica , Proteínas Quinases Ativadas por AMP , Animais , Dieta Hiperlipídica/efeitos adversos , Fígado , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Ácido Oleanólico/análogos & derivados , Proteína de Ligação a Elemento Regulador de Esterol 1
4.
Braz. j. med. biol. res ; 54(10): e11391, 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1285650

RESUMO

Nonalcoholic fatty liver disease (NAFLD), characterized by hepatosteatosis and steatohepatitis, is intrinsically related to obesity. Our previous study reported on the anti-obese activity of α,β-amyrin (AMY), a pentacyclic triterpene isolated from Protium heptaphyllum. This study investigated its ability to prevent fatty liver and the underlying mechanism using the mouse model of NAFLD. NAFLD was induced in male Swiss mice fed a high fat diet (HFD) for 15 weeks. The controls were fed a normal chow diet (ND). The mice were simultaneously treated with AMY at 10 and 20 mg/kg or fenofibrate at 50 mg/kg. Lipid levels along with metabolic and inflammatory parameters were assessed in liver and serum. The liver sections were histologically examined using H&E staining. RT-qPCR and western blotting assays were performed to analyze signaling mechanisms. Mice fed HFD developed severe hepatic steatosis with elevated triglycerides and lipid droplets compared with ND controls. This was associated with a decrease in AMP-activated protein kinase (AMPK) activity, an increase of mechanistic target of rapamycin complex 1 (mTORC1) signaling, and enhanced sterol regulatory element binding protein 1 (SREBP1) expression, which have roles in lipogenesis, inhibition of lipolysis, and inflammatory response. AMY treatment reversed these signaling activities and decreased the severity of hepatic steatosis and inflammatory response, evidenced by serum and liver parameters as well as histological findings. AMY-induced reduction in hepatic steatosis seemed to involve AMPK-mTORC1-SREBP1 signaling pathways, which supported its beneficial role in the prevention and treatment of NAFLD.


Assuntos
Animais , Masculino , Coelhos , Resistência à Insulina , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Ácido Oleanólico/análogos & derivados , Proteína de Ligação a Elemento Regulador de Esterol 1 , Proteínas Quinases Ativadas por AMP , Dieta Hiperlipídica/efeitos adversos , Alvo Mecanístico do Complexo 1 de Rapamicina , Fígado , Camundongos Endogâmicos C57BL
6.
Braz J Med Biol Res ; 50(1): e5630, 2017 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-28076453

RESUMO

Previous studies have reported on the glucose and lipid-lowering effects of ferulic acid (FA) but its anti-obesity potential has not yet been firmly established. This study investigated the possible anti-obesitogenic effects of FA in mice fed a high-fat diet (HFD) for 15 weeks. To assess the antiobesity potential of FA, 32 male Swiss mice, weighing 20-25 g (n=6-8 per group) were fed a normal diet (ND) or HFD, treated orally or not with either FA (10 mg/kg) or sibutramine (10 mg/kg) for 15 weeks and at the end of this period, the body weights of animals, visceral fat accumulation, plasma levels of glucose and insulin hormone, amylase and lipase activities, the satiety hormones ghrelin and leptin, and tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein-1 (MCH-1) were analyzed. Results revealed that FA could effectively suppress the HFD-associated increase in visceral fat accumulation, adipocyte size and body weight gain, similar to sibutramine, the positive control. FA also significantly (P<0.05) decreased the HFD-induced elevations in serum lipid profiles, amylase and lipase activities, and the levels of blood glucose and insulin hormone. The markedly elevated leptin and decreased ghrelin levels seen in HFD-fed control mice were significantly (P<0.05) reversed by FA treatment, almost reaching the values seen in ND-fed mice. Furthermore, FA demonstrated significant (P<0.05) inhibition of serum levels of inflammatory mediators TNF-α, and MCH-1. These results suggest that FA could be beneficial in lowering the risk of HFD-induced obesity via modulation of enzymatic, hormonal and inflammatory responses.


Assuntos
Fármacos Antiobesidade/farmacologia , Ácidos Cumáricos/farmacologia , Ciclobutanos/farmacologia , Gordura Intra-Abdominal/efeitos dos fármacos , Obesidade/tratamento farmacológico , Tecido Adiposo/patologia , Animais , Dieta Hiperlipídica , Modelos Animais de Doenças , Masculino , Camundongos , Obesidade/patologia
7.
Indian J Pharm Sci ; 76(1): 1, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24799732
8.
Neuroradiol J ; 26(6): 636-8, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24355181

RESUMO

Dural-based B cell lymphomas are rare and have a female preponderance. A 60-year-old Asian man with a history of trivial trauma presented with generalised tonic clonic seizures and headache. Imaging and clinical work-up was done. A temporoparietal subdural lesion with no evidence of systemic lymphoma was detected. Intraoperatively, a dural-based mass lesion was seen with thickened dura and biopsy-proven B cell lymphoma, and the patient was then kept on chemotherapy. A suspicion of this rare entity should be considered in imaging of dural-based lesions.


Assuntos
Neoplasias Encefálicas/patologia , Dura-Máter/patologia , Linfoma de Células B/patologia , Humanos , Imuno-Histoquímica , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
9.
Beilstein J Org Chem ; 9: 26-35, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23400045

RESUMO

Non-symmetrically substituted four-ring achiral bent-core compounds with polar substituents, i.e.., chloro in the bent or transverse direction in the central core and cyano in the lateral direction at one terminal end of the molecule, are designed and synthesized. These molecules possess an alkoxy chain attached at only one end of the bent-core molecule. The molecular structure characterization is consistent with data from elemental and spectroscopic analysis. The materials thermal behaviour and phase characterization have been investigated by differential scanning calorimetry and polarizing microscopy. All the compounds exhibit a wide-ranging monotropic nematic phase.

10.
IEEE J Biomed Health Inform ; 17(1): 183-9, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23193312

RESUMO

Coronary heart disease (CHD) caused by hardening of artery walls due to cholesterol known as atherosclerosis is responsible for large number of deaths world-wide. The disease progression is slow, asymptomatic and may lead to sudden cardiac arrest, stroke or myocardial infraction. Presently, imaging techniques are being employed to understand the molecular and metabolic activity of atherosclerotic plaques to estimate the risk. Though imaging methods are able to provide some information on plaque metabolism they lack the required resolution and sensitivity for detection. In this paper we consider the clinical observations and habits of individuals for predicting the risk factors of CHD. The identification of risk factors helps in stratifying patients for further intensive tests such as nuclear imaging or coronary angiography. We present a novel approach for predicting the risk factors of atherosclerosis with an in-built imputation algorithm and particle swarm optimization (PSO). We compare the performance of our methodology with other machine learning techniques on STULONG dataset which is based on longitudinal study of middle aged individuals lasting for twenty years. Our methodology powered by PSO search has identified physical inactivity as one of the risk factor for the onset of atherosclerosis in addition to other already known factors. The decision rules extracted by our methodology are able to predict the risk factors with an accuracy of 99:73% which is higher than the accuracies obtained by application of the state-of-theart machine learning techniques presently being employed in the identification of atherosclerosis risk studies.


Assuntos
Aterosclerose/diagnóstico , Modelos Estatísticos , Simulação por Computador , Bases de Dados Factuais , Árvores de Decisões , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Fatores de Risco
11.
ISA Trans ; 51(3): 400-9, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22405751

RESUMO

In this article, two methods of designing a centralized control system for multi-input, multi-output (MIMO) processes are presented. Centralized proportional-integral (PI) controllers are designed based on a direct synthesis method. The inverse of the process transfer function matrix in the direct synthesis method is approximated based on the relative gain array concept. The method is further improved by using a relative normalized gain array, and an equivalent transfer function for each element in the process transfer function matrix is derived for the closed-loop control system. The transpose of the effective transfer function is used to approximate the inverse of the process transfer function matrix. The simulation studies demonstrate the effectiveness of this method. The proposed centralized controllers reduce the interactions better than recently reported decentralized controllers do. A centralized controller designed based on a relative normalized gain array (RNGA) gives a better performance than a centralized controller designed based on a relative gain array (RGA).

13.
J Surg Oncol ; 105(8): 745-9, 2012 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-22161989

RESUMO

BACKGROUND: Circumferential resection margin (CRM) is widely recognized as an important prognostic factor in esophageal cancer. The aim of this study was to evaluate the clinical significance of CRM according to the current criteria of the Royal College of Pathologists (RCP) and the College of American Pathologists (CAP). METHODS: Patients (115) who underwent esophagectomy between 2000 and 2006 were included in this retrospective study. Factors such as neo-adjuvant therapy, site, histological type, size, and lymph node involvement were tested to determine predictability of CRM involvement. Along with these, age, sex, CRM, and adjuvant therapy were analyzed to determine influence on survival. RESULTS: On the basis of CRM, patients were divided into three groups (involved, 0.1-1 mm and >1mm). Size (T) was the only factor strongly predictive of CRM involvement (P < 0.001). Size (T; P = 0.04) and lymph node involvement (N; P = 0.0003) were found to significantly influence overall survival (OS). When patients with CRM (involved and 0.1-1mm) were compared with those with CRM > 1 mm, OS was significantly prolonged in the latter (P = 0.02). CONCLUSION: This study appears to lend credence to the RCP criteria for definition of CRM over the CAP criteria.


Assuntos
Adenocarcinoma/cirurgia , Carcinoma de Células Escamosas/cirurgia , Neoplasias Esofágicas/cirurgia , Esofagectomia/mortalidade , Linfonodos/patologia , Linfonodos/cirurgia , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida
14.
Case Rep Surg ; 2011: 509806, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22606582

RESUMO

Perforation of the gastrointestinal tract by ingested foreign body is rare. The majority of patients do not recall ingestion of the foreign body, and dietary foreign bodies are most commonly involved. We present an interesting case where the offending foreign body gave rise to a diagnostic dilemma masquerading as a pancreatic mass. A high index of suspicion is indicated especially when dealing with atypical presentation and nonspecific symptoms as highlighted in this case.

15.
Mutat Res ; 701(2): 153-63, 2010 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-20599626

RESUMO

Kaurane diterpenes are considered important compounds in the development of new highly effective anticancer chemotherapeutic agents. Genotoxic effects of anticancer drugs in non-tumour cells are of special significance due to the possibility that they induce secondary tumours in cancer patients. In this context, we evaluated the genotoxic and mutagenic potential of the natural diterpenoid kaurenoic acid (KA), i.e. (-)-kaur-16-en-19-oic acid, isolated from Xylopia sericeae St. Hill, using several standard in vitro and in vivo protocols (comet, chromosomal aberration, micronucleus and Saccharomyces cerevisiae assays). Also, an analysis of structure-activity relationships was performed with two natural diterpenoid compounds, 14-hydroxy-kaurane (1) and xylopic acid (2), isolated from X. sericeae, and three semi-synthetic derivatives of KA (3-5). In addition, considering the importance of the exocyclic double bond (C16) moiety as an active pharmacophore of KA cytotoxicity, we also evaluated the hydrogenated derivative of KA, (-)-kauran-19-oic acid (KAH), to determine the role of the exocyclic bond (C16) in the genotoxic activity of KA. In summary, the present study shows that KA is genotoxic and mutagenic in human peripheral blood leukocytes (PBLs), yeast (S. cerevisiae) and mice (bone marrow, liver and kidney) probably due to the generation of DNA double-strand breaks (DSB) and/or inhibition of topoisomerase I. Unlike KA, compounds 1-5 and KAH are completely devoid of genotoxic and mutagenic effects under the experimental conditions used in this study, suggesting that the exocyclic double bond (C16) moiety may be the active pharmacophore of the genetic toxicity of KA.


Assuntos
Diterpenos/química , Diterpenos/toxicidade , Mutagênicos/toxicidade , Extratos Vegetais/toxicidade , Animais , Linhagem Celular Tumoral , Humanos , Masculino , Camundongos , Testes de Mutagenicidade , Relação Estrutura-Atividade
16.
Phytomedicine ; 17(10): 740-3, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20149612

RESUMO

The anti-inflammatory effect of physalin E, a seco-steroid isolated from Physalis angulata L. was evaluated on acute and chronic models of dermatitis induced by 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and oxazolone, respectively, in mouse ear. The changes in ear edema/thickness, production of pro-inflammatory cytokines (TNF-alpha and IFN-gamma), myeloperoxidase (MPO) activity, and histological and immunohistochemical findings were analysed, as indicators of dermal inflammation. Similar to dexamethasone, topically applied Physalin E (0.125; 0.25 and 0.5 mg/ear) potently inhibited the TPA and oxazolone-induced dermatitis, leading to substantial reductions in ear edema/thickness, pro-inflammatory cytokines, and MPO activity. These effects were reversed by mifepristone, a steroid antagonist and confirmed by immunohistochemical and histopathological analysis. The data suggest that physalin E may be a potent and topically effective anti-inflammatory agent useful to treat the acute and chronic skin inflammatory conditions.


Assuntos
Anti-Inflamatórios/uso terapêutico , Dermatite de Contato/tratamento farmacológico , Physalis/química , Secoesteroides/uso terapêutico , Animais , Imuno-Histoquímica , Masculino , Camundongos , Oxazolona/toxicidade , Acetato de Tetradecanoilforbol/toxicidade
17.
Res Pharm Sci ; 5(1): 57-63, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21589769

RESUMO

Polarographic methods have been developed for the determination of two cephalosporins namely cefotaxime (CTX) and ceftriaxone (CTR) in pharmaceutical formulations. Well defined peaks at potentials -1.432 V vs. SCE for CTX and -1.627 V vs. SCE for CTR were obtained in the presence of tungsten (VI). The method has been successfully applied for the determination of above mentioned cephalosporins in commercial dosage forms. The salient features of this investigation are presented in this communication.

18.
Radiat Res ; 172(6): 725-36, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19929419

RESUMO

Intracellular calcium oscillations have long been recognized as a principal mediator of many vital cellular activities. Furthermore, Ca(2+) dynamics can be modulated by external physical cues, including electromagnetic fields. While cellular responses to low-frequency electric fields have been established, the possible non-thermal effects of millimeter-wave (MMW) radiation are still a subject of discussion and debate. We used mouse embryonic stem cell-derived neuronal cells and a custom-built 94 GHz applicator to examine in real time the altered Ca(2+) oscillations associated with MMW stimulation. MMW irradiation at 18.6 kW/m(2) nominal power density significantly increased the Ca(2+) spiking frequency in the cells exhibiting Ca(2+) activity. The N-type calcium channels, phospholipase C enzyme, and actin cytoskeleton appear to be involved in mediating increased Ca(2+) spiking. Reorganization of the actin microfilaments by a 94 GHz field seems to play a crucial role in modulating not only Ca(2+) activity but also cell biomechanics. Many but not all observed cellular responses to MMW were similar to thermally induced effects. For example, cell exposure to a 94 GHz field induced nitric oxide production in some morphologically distinct neuronal cells that could not be reproduced by thermal heating of the cells up to 42 degrees C. The highest observed average temperature rise in the MMW exposure chamber was approximately 8 degrees C above the room temperature, with possible complex non-uniform microscopic distribution of heating rates at the cell level. Our findings may be useful to establish quantitative molecular benchmarks for elucidation of nociception mechanisms and evaluation of potential adverse bioeffects associated with MMW exposure. Moreover, control of Ca(2+) dynamics by MMW stimulation may offer new tools for regulation of Ca(2+)-dependent cellular and molecular activities, for example, in tissue engineering applications.


Assuntos
Cálcio/metabolismo , Neurônios/efeitos da radiação , Animais , Linhagem Celular Tumoral , Camundongos , Microscopia de Força Atômica , Microscopia Confocal , Neurônios/metabolismo , Óxido Nítrico/biossíntese
19.
Bioorg Med Chem Lett ; 18(23): 6054-7, 2008 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-18948000

RESUMO

A series of N-2-(4-(4-(2-substitutedthiazol-4-yl) piperazin-1-yl)-2-oxoethyl)acetamides were synthesized in an effort to prepare novel atypical antipsychotic agents. The compounds were synthesized by either microwave irradiation technique or by conventional synthesis and were characterized by spectral data (IR, (1)H NMR, and MS) and the purity was ascertained by microanalysis. All the synthesized compounds were screened for their in vivo pharmacological activity in Swiss albino mice. D(2) antagonism studies were performed using climbing mouse assay model and 5-HT(2A) antagonism studies were performed using quipazine induced head twitches in mice. It was observed that none of the new chemical entities exhibited catalepsy. AG 3 was found to be the most active compound.


Assuntos
Acetamidas/síntese química , Acetamidas/farmacologia , Antipsicóticos/síntese química , Antipsicóticos/farmacologia , Piperazinas/síntese química , Piperazinas/farmacologia , Antagonistas do Receptor 5-HT2 de Serotonina , Acetamidas/química , Animais , Antipsicóticos/química , Técnicas de Química Combinatória , Modelos Animais de Doenças , Movimentos da Cabeça/efeitos dos fármacos , Camundongos , Estrutura Molecular , Atividade Motora/efeitos dos fármacos , Piperazinas/isolamento & purificação , Quipazina/farmacologia
20.
Opt Lett ; 33(14): 1587-9, 2008 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-18628806

RESUMO

The waveguide-length sensitivity on modified spontaneous emission in finite-size planar photonic crystal (PC) waveguides is investigated by numerically computing the exact Purcell (enhanced emission) factor. An unusual dependence on the number of waveguide unit cells and on the waveguide facet truncation is found, allowing one to nanoengineer large Purcell factors in excess of several hundred. Besides having important applications for single-photon sources, these results offer physical insight into the nature of light-matter interactions in miniaturized finite-size PC waveguides, where periodic Bloch-wave analysis breaks down.

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