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1.
Nanotechnology ; 34(49)2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37669646

RESUMO

We report observation of more than an order of magnitude jump in saturation magnetization in BiFeO3/Ag nanocomposite at room temperature compared to what is observed in bare BiFeO3nanoparticles. Using transmission electron microscopy together with energy dispersive x-ray spectra (which maps the element concentration across the BiFeO3/Ag interface) and x-ray photoelectron spectroscopy, we show that both the observed specific self-assembly pattern of BiFeO3and Ag nanoparticles and the charge transfer between Ag and O are responsible for such an enormous rise in room-temperature magnetization. The BiFeO3/Ag nanocomposites, therefore, could prove to be extremely useful for a variety of applications including biomedical.

2.
Homeopathy ; 112(3): 184-197, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36442593

RESUMO

OBJECTIVES: This study aimed to evaluate whether individualized homeopathic medicines have a greater adjunctive effect than adjunctive placebos in the treatment of moderate and severe cases of coronavirus disease 2019 (COVID-19). METHODS: The study was a randomized, single-blind, prospective, placebo-controlled clinical trial set in the clinical context of standard care. INTERVENTION: Patients of either sex, admitted in a tertiary care hospital, suffering from moderate or severe COVID-19 and above 18 years of age were included. In total, 150 patients were recruited and then randomly divided into two groups to receive either individualized homeopathic medicines or placebos, in addition to the standard treatment of COVID-19. OUTCOME MEASURES: The primary outcome was time taken to achieve RT-PCR-confirmed virus clearance for COVID-19. Secondary outcomes were changes in the Clinical Ordinal Outcomes Scale (COOS) of the World Health Organization, the patient-reported MYMOP2 scale, and several biochemical parameters. Parametric data were analyzed using unpaired t-test. Non-parametric data were analyzed using the Wilcoxon signed rank test. Categorical data were analyzed using Chi-square test. RESULTS: In total, 72 participants of the add-on homeopathy (AoH) group showed conversion of RT-PCR status to negative, in an average time of 7.53 ± 4.76 days (mean ± SD), as compared with 11.65 ± 9.54 days in the add-on placebo (AoP) group (p = 0.001). The mean COOS score decreased from 4.26 ± 0.44 to 3.64 ± 1.50 and from 4.3 ± 0.46 to 4.07 ± 1.8 in the AoH and AoP groups respectively (p = 0.130). The mortality rate for the AoH group was 9.7% compared with 17.3% in the AoP group. The MYMOP2 scores between the two groups differed significantly (p = 0.001), in favor of AoH. Inter-group differences in the pre- and post- mean values of C-reactive protein, fibrinogen, total leukocyte count, platelet count and alkaline phosphatase were each found to be statistically significant (p <0.05), favoring AoH; six other biochemical parameters showed no statistically significant differences. CONCLUSION: The study suggests homeopathy may be an effective adjunct to standard care for treating moderate and severe COVID-19 patients. More rigorous, including double-blinded, studies should be performed to confirm or refute these initial findings.


Assuntos
COVID-19 , Homeopatia , Humanos , COVID-19/terapia , SARS-CoV-2 , Estudos Prospectivos , Método Simples-Cego , Método Duplo-Cego , Resultado do Tratamento
3.
PLoS Biol ; 11(11): e1001720, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24302887

RESUMO

Planar cell polarity (PCP) regulates cell alignment required for collective cell movement during embryonic development. This requires PCP/PCP effector proteins, some of which also play essential roles in ciliogenesis, highlighting the long-standing question of the role of the cilium in PCP. Wdpcp, a PCP effector, was recently shown to regulate both ciliogenesis and collective cell movement, but the underlying mechanism is unknown. Here we show Wdpcp can regulate PCP by direct modulation of the actin cytoskeleton. These studies were made possible by recovery of a Wdpcp mutant mouse model. Wdpcp-deficient mice exhibit phenotypes reminiscent of Bardet-Biedl/Meckel-Gruber ciliopathy syndromes, including cardiac outflow tract and cochlea defects associated with PCP perturbation. We observed Wdpcp is localized to the transition zone, and in Wdpcp-deficient cells, Sept2, Nphp1, and Mks1 were lost from the transition zone, indicating Wdpcp is required for recruitment of proteins essential for ciliogenesis. Wdpcp is also found in the cytoplasm, where it is localized in the actin cytoskeleton and in focal adhesions. Wdpcp interacts with Sept2 and is colocalized with Sept2 in actin filaments, but in Wdpcp-deficient cells, Sept2 was lost from the actin cytoskeleton, suggesting Wdpcp is required for Sept2 recruitment to actin filaments. Significantly, organization of the actin filaments and focal contacts were markedly changed in Wdpcp-deficient cells. This was associated with decreased membrane ruffling, failure to establish cell polarity, and loss of directional cell migration. These results suggest the PCP defects in Wdpcp mutants are not caused by loss of cilia, but by direct disruption of the actin cytoskeleton. Consistent with this, Wdpcp mutant cochlea has normal kinocilia and yet exhibits PCP defects. Together, these findings provide the first evidence, to our knowledge, that a PCP component required for ciliogenesis can directly modulate the actin cytoskeleton to regulate cell polarity and directional cell migration.


Assuntos
Citoesqueleto de Actina/metabolismo , Movimento Celular , Cílios/fisiologia , Proteínas do Citoesqueleto/fisiologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Polaridade Celular , Células Cultivadas , Análise Mutacional de DNA , Adesões Focais/metabolismo , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único , Transporte Proteico , Septinas/metabolismo , Imagem com Lapso de Tempo , Via de Sinalização Wnt , Peixe-Zebra
4.
Am J Pathol ; 179(5): 2589-600, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21933655

RESUMO

Tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) belongs to a small family of endogenous proteins that inhibits a group of enzymes, the matrix metalloproteinases (MMPs). TIMP-2 inhibits endothelial cell proliferation and migration in vitro and angiogenesis in vivo, through MMP-dependent and -independent mechanisms. However, little is known regarding the contribution of these mechanisms to the antitumor effects of TIMP-2. Using a retroviral delivery system, we stably overexpressed TIMP-2 and its mutant Ala+TIMP-2 (devoid of MMP inhibitory activity) in human adenocarcinoma A549 cells. Using real time PCR, and enzyme-linked immunosorbent assay (ELISA), we confirmed enhanced TIMP-2 expression and its MMP inhibitory activity by reverse zymography. In vitro, growth assays suggested that TIMP-2 and Ala+TIMP-2 did not alter basal cell proliferation rates, however, tumor cell migration and invasion were inhibited. In vivo, both TIMP-2 and Ala+TIMP-2 A549 xenografts exhibited reduced growth rate, CD31 immunostaining indicated decreased intratumoral microvascular density, and TUNEL demonstrated enhanced tumor cell apoptosis. Immunoblotting and immunohistochemical analyses of A549 xenograft tissues with either phospho-FAK (Tyr397) or phospho-AKT (Ser473) showed decreased activation in both TIMP-2 and Ala+TIMP-2 tumor cells. We conclude that TIMP-2-mediated inhibition of tumor growth occurs, at least in part, independently of MMP inhibition, and is a consequence of both direct effects of TIMP-2 on tumor cells and modulation of the tumor microenvironment.


Assuntos
Adenocarcinoma/irrigação sanguínea , Neoplasias Pulmonares/irrigação sanguínea , Inibidores de Metaloproteinases de Matriz , Neovascularização Patológica/enzimologia , Inibidor Tecidual de Metaloproteinase-2/fisiologia , Microambiente Tumoral/fisiologia , Adenocarcinoma/enzimologia , Animais , Apoptose/fisiologia , Movimento Celular , Proliferação de Células , Feminino , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Humanos , Neoplasias Pulmonares/enzimologia , Camundongos , Camundongos Nus , Microvasos , Invasividade Neoplásica , Transplante de Neoplasias , Proteínas Proto-Oncogênicas c-akt/metabolismo , Inibidor Tecidual de Metaloproteinase-2/metabolismo , Transplante Heterólogo , Células Tumorais Cultivadas
5.
Environ Technol ; 32(13-14): 1503-14, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22329141

RESUMO

Chitosan hydrogel beads (CSB) formed by sodium dodecyl sulphate (SDS) gelation were used for the removal of a cationic dye, methylene blue (MB), from aqueous solutions. The adsorption capacity of chitosan beads (CB) formed by alkali gelation was low because of charge repulsions between the chitosan (CS) and the MB. The adsorption capacity of CSB (4 g/L SDS gelation) for MB (100 mg/L) was 129.44 mg/g, and it decreased significantly with increasing SDS concentration during gelation. This decrease was a result of increased density of the CSB membrane materials. The CSB membrane materials formed with the 4 g/L SDS gelation showed the highest volumetric adsorption capacity. The MB adsorption on to CB and CSB increased with increasing values for the initial pH of solution. Data from both CB and CSB showed good fit to Sips isotherm models, and the maximum adsorption capacity of CSB (226.24 mg/g) was higher than that of CB (99.01 mg/g).


Assuntos
Quitosana/química , Hidrogéis/química , Azul de Metileno/química , Azul de Metileno/isolamento & purificação , Tensoativos/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Adsorção , Ânions , Cátions , Corantes/química , Corantes/isolamento & purificação , Poluentes Químicos da Água/química
6.
Bioresour Technol ; 102(6): 4402-9, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21277770

RESUMO

The adsorption performance of chitosan (CS) hydrogel beads (CSBs) generated by sodium dodecyl sulfate (SDS) gelation with multi-walled carbon nanotube (CNT) impregnation was investigated for Congo red removal as a model anionic dye. CNT-impregnated CSBs were prepared by four different strategies for dispersing CNTs: (a) in CS solution (CSBN1), (b) in SDS solution (CSBN2), (c) in CS solution containing cetyltrimethylammonium bromide (CTAB) (CSBN3), and (d) in SDS solution for gelation with CTAB-containing CS solution (CSBN4). It was observed from FE-SEM study that depending on nature of CNT dispersion, CNTs were found on the outer surface of CSBN2 and CSBN4 only. The adsorption capacity of the CSBs varied with the strategy used for CNT impregnation, and CSBN4 exhibited the highest maximum adsorption capacity (375.94 mg/g) from the Sips model. The lowest Sips maximum adsorption capacity by CSBN3 (121.07 mg/g) suggested significant blocking of binding sites of CS by CNT impregnation.


Assuntos
Quitosana/química , Vermelho Congo/isolamento & purificação , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Microesferas , Nanotubos de Carbono/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Modelos Químicos , Dodecilsulfato de Sódio/química , Soluções , Temperatura , Água/química
7.
Bioresour Technol ; 101(11): 3853-8, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20129778

RESUMO

A new type of chitosan hydrogel beads (CSB) with a core-shell membrane structure was generated by sodium dodecyl sulfate (SDS) gelation process. CSB exhibited higher mechanical strength and acid stability than chitosan hydrogel beads (CB) formed by alkali gelation. The effect of SDS concentration variation during gelation on the adsorption capacity of CSB for congo red (CR) as a model anionic dye showed that CSB formed by 4gl(-1) SDS gelation had the highest adsorption capacity. The maximum adsorption capacity of CSB (208.3mgg(-1)) obtained from the Sips model was found slightly higher than that of CB (200.0mgg(-1)). Membrane materials of CSB obtained after squeezing core water from the beads showed approximately 25 times higher volumetric adsorption capacity than CB.


Assuntos
Hidrogéis/química , Tensoativos/química , Adsorção , Ânions , Quitosana/química , Géis , Dodecilsulfato de Sódio/química
8.
Chemosphere ; 75(10): 1307-14, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19345394

RESUMO

Effective coagulation and separation of particles in a soil-washed solution is required for a successful soil washing process. The effectiveness of chitosan (CS), a polycationic biodegradable polymer, as a coagulant was compared to polyacrylamide (PAA) and polyaluminium chloride (PAC) for the coagulation of a soil suspension (5 gL(-1)). The effect of surfactants in the coagulation process was investigated using Triton X-100 (TX-100), a nonionic surfactant, and sodium dodecyl sulfate (SDS), an anionic surfactant. CS (5 mgL(-1)) removed 86% and 63% of the suspended soil in the presence of TX-100 (5 gL(-1)) and SDS (5 gL(-1)), respectively, after 30 min at a pH of 6. The results prove that coagulation in the presence of TX-100 is more effective than with SDS. CS was found to be more efficient compared to PAA and PAC under all coagulation conditions. The optimum concentration of CS required for maximum coagulation of soil suspension was 5 mgL(-1). PAA and PAC could not achieve the same degree soil removal as CS even after increasing their concentrations up to 50 mgL(-1). Maximum levels of 50% and 60% soil removal were achieved using PAA (50 mgL(-1)) and PAC (50 mgL(-1)), respectively, after 30 min from a 5 gL(-1) suspension containing TX-100 (5 gL(-1)). The soil coagulation process was found to decrease with an increase in the pH of the suspension, and maximum coagulation was achieved with an acidic pH.


Assuntos
Resinas Acrílicas/química , Hidróxido de Alumínio/química , Quitosana/química , Recuperação e Remediação Ambiental/métodos , Poluentes do Solo/química , Solo , Tensoativos/química , Precipitação Química , Concentração de Íons de Hidrogênio , Octoxinol/química , Dodecilsulfato de Sódio/química , Fatores de Tempo
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