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1.
Appl Radiat Isot ; 200: 110949, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37582315

RESUMO

Activation and off-line γ-ray spectrometric methods were used to measure the ground and isomeric state (n,2n) reaction cross section for 103Rh at two different neutron energies. The standard 27Al (n,α)24Na reference reaction was used to normalise neutron flux. The proton beam from the 14UD BARC-TIFR Pelletron facility in Mumbai, India, was utilised to create high-energy quasi-monoenergetic neutrons via the 7Li (p,n) reaction. Statistical model calculations including the level density, pre-equilibrium and optical potential model were performed using the TALYS (ver. 1.95) and EMPIRE (ver. 3.2.3) reaction codes. In addition, because of considerable discrepancies in measured data, the literature (n,p) reaction cross section of 52Cr and 48Ti targets were examined theoretically in the present work. The measured cross sections are discussed and compared with the latest evaluated data of the FENDL-3.2b, CENDL-3.2, TENDL-2019, JENDL-5.0, and ENDF/B-VIII.0 libraries, and experimental data based on the EXFOR compilation. The theoretical investigation of the (n,2n) reaction cross section was performed for the ground and isomeric state for the first time from reaction threshold to 25 MeV energies. The experimental data corresponding to the ground, isomeric state and isomeric ratio were reproduced consistently by the theoretical calculations. The present experimental results are good with certain literature data and theoretical values.

2.
Front Microbiol ; 13: 841666, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35464920

RESUMO

The utility of fungi as stabilizing and reducing agents in the biogenic synthesis of silver nanoparticles is striking due to the production of large quantities of biomolecules of minute toxic residuals. During the current study, sunlight- and dark-assessed silver nanoparticles were synthesized from wasp nest fungus, Paecilomyces variotii, at different pHs. Synthesized silver nanoparticles (AgNPs) at 6 pH were found to be more prominent than at 7 and 8 pHs. AgNPs were within the 20- to 90-nm range and were polygonal and elongated in shape. FTIR spectra of light-mediated AgNPs showed diverse transmittance bands than the silver nanoparticles synthesized in the dark. The synthesized AgNPs were found with diverse antimicrobial activities against pathogenic MTCC bacterial strains, i.e., Staphylococcus aureus, Vibrio parahaemolyticus, Escherichia coli, Shewanella putrefaciens, and fungus, Candida albicans. Aqueous filtrate and filtrate-mediated AgNPs combined with methanol solvent extract of yeast extract manitol broth (YEMB) had more inhibitory effects on all bacteria and Candida albicans. Furthermore, the combined effect of AgNPs and methanol solvent extract from YEMB culture filtrate was found more effective against E. coli, while AgNPs combined with methanol solvent of aqueous filtrate had inhibitory effects on E. coli and Candida albicans.

3.
Appl Radiat Isot ; 143: 72-78, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30390503

RESUMO

The neutron capture cross sections of 232Th and 238U at the average neutron energies of 5.08 ±â€¯0.17, 8.96 ±â€¯0.77, 12.47 ±â€¯0.83, and 16.63 ±â€¯0.95 MeV have been measured by using the activation technique and off-line γ-ray spectroscopy. The 232Th and 238U were irradiated with neutrons produced from the 7Li(p, n) reaction using the proton energies of 7, 11, 15 and 18.8 MeV from the 14UD BARC-TIFR Pelletron facility in Mumbai, India. Detailed covariance analysis was also performed to evaluate the uncertainties in the measured cross-sections. The excitation function of the 232Th(n, γ) and 238U(n, γ) reactions were calculated using the theoretical model code TALYS-1.9. The experimental and theoretical results from the present work were compared with the ENDF/B-VII-1 and JENDL-4.0 nuclear data libraries and were found to be in good agreement.

4.
Appl Radiat Isot ; 141: 10-14, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30144772

RESUMO

The neutron capture cross-sections have been measured for the 159Tb(n, γ)160Tb reaction at the spectrum average peak neutron energies of 5.08 ±â€¯0.165, 12.47 ±â€¯0.825, and 16.63 ±â€¯0.95 MeV respectively. The experiment has been carried out using the standard neutron activation technique and off-line γ-ray spectrometry. The present measurement has been done for the energies where very few measured results are available in the data library. The results have been compared with ENDF/B-VII.1 and JENDL-4.0 data libraries. The present results have also been supported by theoretical predictions of nuclear model code TALYS 1.9. Detailed covariance analysis was carried out to find the uncertainty and the correlations among the measured cross-sections.

5.
Colloids Surf B Biointerfaces ; 165: 182-190, 2018 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29482129

RESUMO

Spray drying had been used to synthesize silica-carbon black nanocomposite micrometric granules with a uniform distribution of the two components. This was achieved by hindering the preferential diffusion of hydrophobic carbon and hydrophilic silica particles in the water droplets during evaporative assembly by introducing gum arabic as a stabilizing agent and network former. Both positive and negatively charged silica nanoparticles were used to check the stability of the sol and its effect on the morphology of the spray dried granules. X-ray and neutron scattering, complemented with electron microscopy, were used to investigate the correlation and distribution of the nanoparticles within the granules. Porous silica granules, having surface area of 157 m2/g, were obtained after removal of carbon black by calcination. An environment-friendly solar absorbing coating had been prepared using as synthesized granules.


Assuntos
Carbono/química , Goma Arábica/química , Nanocompostos/química , Nanopartículas/química , Dióxido de Silício/química , Dessecação , Difusão , Interações Hidrofóbicas e Hidrofílicas , Nanocompostos/ultraestrutura , Nanopartículas/ultraestrutura , Tamanho da Partícula , Porosidade , Eletricidade Estática
7.
Phys Rev Lett ; 110(17): 172504, 2013 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-23679714

RESUMO

Two distinct sets of chiral-partner bands have been identified in the nucleus 133Ce. They constitute a multiple chiral doublet, a phenomenon predicted by relativistic mean field (RMF) calculations and observed experimentally here for the first time. The properties of these chiral bands are in good agreement with results of calculations based on a combination of the constrained triaxial RMF theory and the particle-rotor model.

8.
Oncogene ; 32(26): 3147-55, 2013 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-22869144

RESUMO

Hypoxia inducible factor-2α (HIF-2α) has a critical role in renal tumorigenesis. HIF-2α is stabilized in von Hippel-Lindau (VHL)-deficient renal cell carcinoma through mechanisms that require ongoing mRNA translation. Mammalian target of rapamycin (mTOR) functions in two distinct complexes: Raptor-associated mTORC1 and Rictor-associated mTORC2. Rictor-associated mTORC2 complex has been linked to maintaining HIF-2α protein in the absence of VHL; however, the mechanisms remain to be elucidated. Although Raptor-associated mTORC1 is a known key upstream regulator of mRNA translation, initiation and elongation, the role of mTORC2 in regulating mRNA translation is not clear. Complex assembly of the mRNA cap protein, eukaryotic translation initiation factor 4 (eIF4)E, with activators (eIF4 gamma (eIF4G)) and inhibitors (eIF4E-binding protein 1 (4E-BP1)) are rate-limiting determinants of mRNA translation. Our laboratory has previously demonstrated that reactive oxygen species, mediated by p22(phox)-based Nox oxidases, are enhanced in VHL-deficient cells and have a role in the activation of Akt on S473, a site phosphorylated by the mTORC2 complex. In this study, we examined the role of Rictor-dependent regulation of HIF-2α through eIF4E-dependent mRNA translation and examined the effects of p22(phox)-based Nox oxidases on TORC2 regulation. We demonstrate for the first time that mTORC2 complex stability and activation is redox sensitive, and further defined a novel role for p22(phox)-based Nox oxidases in eIF4E-dependent mRNA translation through mTORC2. Furthermore, we provide the first evidence that silencing of p22(phox) reduces HIF-2α-dependent gene targeting in vitro and tumor formation in vivo. The clinical relevance of these studies is demonstrated.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Carcinoma de Células Renais/metabolismo , Complexos Multiproteicos/metabolismo , NADPH Oxidases/metabolismo , Biossíntese de Proteínas , RNA Mensageiro/genética , Serina-Treonina Quinases TOR/metabolismo , Animais , Carcinoma de Células Renais/genética , Linhagem Celular Tumoral , Transformação Celular Neoplásica , Ativação Enzimática , Fator de Iniciação 4E em Eucariotos/metabolismo , Humanos , Alvo Mecanístico do Complexo 2 de Rapamicina , Camundongos , NADPH Oxidases/genética , Transplante de Neoplasias , Oxirredução , Transplante Heterólogo , Proteína Supressora de Tumor Von Hippel-Lindau/metabolismo
9.
Oncogene ; 32(16): 2027-36, 2013 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-22733130

RESUMO

The cyclin-dependent kinase inhibitor p27 is a key regulator of cell-cycle progression. Its expression and localization are altered in several types of malignancies, which has prognostic significance in cancers such as renal cell carcinoma (RCC). S-phase kinase-associated protein 2 (SKP-2) is an F-box protein that is part of the SKP-1/Cul1/F-box ubiquitin ligase complex that targets nuclear p27 among many other cell-cycle proteins for proteosomal degradation. Its overexpression has been observed in several tumor types. Signaling by phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) has previously been shown to regulate the SKP-2/p27 axis. Recent evidence suggests that PI3K signaling may activate mammalian target of rapamycin complex 2 (mTORC2) activity. As PI3K signaling is known to regulate SKP-2 and p27, we sought to determine whether these effects were mediated by mTORC2. Here we provide additional genetic evidence that PI3K signaling activates mTORC2 kinase activity. We also demonstrate a novel role for mTORC2 in the modulation of nuclear p27 levels. In particular, mTORC2 signaling promotes the reduction of nuclear p27 protein levels through the increased protein expression of SKP-2. These are the first data to demonstrate a role for mTOR in the regulation of SKP-2. In concordance with these findings, mTORC2 activity promotes cell proliferation of RCC cells at the G1-S interphase of the cell cycle. Collectively, these data implicate mTORC2 signaling in the regulation of the SKP-2/p27 axis, a signaling node commonly altered in cancer.


Assuntos
Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Complexos Multiproteicos/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Carcinoma de Células Renais/enzimologia , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Processos de Crescimento Celular/fisiologia , Inibidor de Quinase Dependente de Ciclina p27/genética , Células HEK293 , Humanos , Neoplasias Renais/enzimologia , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Alvo Mecanístico do Complexo 2 de Rapamicina , Complexos Multiproteicos/antagonistas & inibidores , Proteína Oncogênica v-akt/metabolismo , Proteínas Quinases Associadas a Fase S/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/antagonistas & inibidores , Transfecção
11.
Indian J Ophthalmol ; 57(2): 99-103, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19237781

RESUMO

AIM: We conducted this study to evaluate and compare corneal endothelial cell loss between phacoemulsification with continuous anterior chamber infusion using anterior chamber maintainer (ACM) and phacoemulsification using ophthalmic viscosurgical device (OVD). MATERIALS AND METHODS: This was a prospective, randomized controlled trial. Fifty eyes of 47 patients of senile cataract undergoing phacoemulsification were included. Patients were randomly allocated into two groups of 25 eyes each. Cataract surgery was performed by phacoemulsification with anterior chamber (AC) continuous infusion with balanced salt solution (BSS) plus and ACM without OVD in Group A, and in Group B, phacoemulsification was performed using OVD with BSS plus. Corneal endothelial cell count and pachymetry were performed preoperatively and postoperatively on day 1, day 7, and day 30. The mean increase in pachymetry was 4.86%, 2.94%, and 1.94%, (Group A) and 5.95%, 3.94%, and 0.51%, (Group B) on first, seventh, and 30 th postoperative day respectively. The difference between the percentage increase in pachymetry between the two groups was not significant at day 1 ( P = 0.441), day 7 ( P = 0.298), and day 30 ( P =0.174) postoperatively. The density of endothelial cells decreased postoperatively (day 30) by 7.38% (Group A) and 7.47% (Group B) without any significant statistical difference ( P = 0.983) between two groups. CONCLUSION: Use of ACM for continuous AC infusion and omission of OVD during phacoemulsification did not cause significant difference in corneal swelling or endothelial cell loss in the immediate postoperative period up to one month.


Assuntos
Câmara Anterior/efeitos dos fármacos , Bicarbonatos/administração & dosagem , Doenças da Córnea/etiologia , Endotélio Corneano/patologia , Glutationa/administração & dosagem , Ácido Hialurônico/administração & dosagem , Complicações Intraoperatórias , Facoemulsificação/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Contagem de Células , Combinação de Medicamentos , Feminino , Humanos , Implante de Lente Intraocular , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Viscossuplementos/administração & dosagem
14.
Phys Rev Lett ; 99(16): 162503, 2007 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-17995244

RESUMO

The strength distributions of the giant monopole resonance (GMR) have been measured in the even-A Sn isotopes (A=112-124) with inelastic scattering of 400-MeV alpha particles in the angular range 0 degrees -8.5 degrees . We find that the experimentally observed GMR energies of the Sn isotopes are lower than the values predicted by theoretical calculations that reproduce the GMR energies in 208Pb and 90Zr very well. From the GMR data, a value of Ktau = -550 +/- 100 MeV is obtained for the asymmetry term in the nuclear incompressibility.

16.
Radiat Res ; 165(6): 645-54, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16802864

RESUMO

The objective of this study was to investigate whether exposure of human monocytes to a pulsed ultra-wideband electromagnetic field (EMF) of 1 kV/cm average peak power triggers a signaling pathway responsible for the transcriptional regulation of NFKB (NF-kappaB)-dependent gene expression. Human Mono Mac 6 (MM6) cells were exposed intermittently to EMF pulses for a total of 90 min. The pulse width was 0.79+/-0.01 ns and the pulse repetition rate was 250 pps. The temperature of the medium was maintained at 37 degrees C in both sham- and EMF-exposed flasks. Total NFKB DNA-binding activity was measured in the nuclear extracts by the electrophoretic mobility shift assay. Cells exposed to the EMFs and incubated for 24 h postexposure showed a 3.5+/-0.2-fold increase in the NFKB DNA-binding activity. Since activation of NFKB was observed, the possibility of kappaB-dependent gene expression in response to exposure to the EMFs was investigated using NFKB signal-specific gene arrays. The results revealed no difference in the NFKB-dependent gene expression profiles at 8 or 24 h postexposure, indicating that activated NFKB does not lead to the differential expression of kappaB-dependent target genes. To determine whether the absence of the kappaB-dependent gene expression was due to compromised transcriptional regulation of NFKB, the functional activity of NFKB was examined in cells transiently transfected with Mercury Pathway constructs containing 4x NFKB binding sites associated either with the luciferase reporter system or a control vector. Pulsed EMF exposure did not induce NFKB-driven luciferase activity in these cells, indicating that the activation of NFKB at 24 h after the 1 kV/cm EMF exposure is functionally inactive. From these results, it is clear that the EMF-induced NFKB activation is only a transient response, with minimal or no downstream effect.


Assuntos
Transporte Ativo do Núcleo Celular/fisiologia , DNA/metabolismo , Campos Eletromagnéticos , Expressão Gênica/fisiologia , Monócitos/metabolismo , Monócitos/efeitos da radiação , NF-kappa B/metabolismo , Ativação Transcricional/fisiologia , Transporte Ativo do Núcleo Celular/efeitos da radiação , Células Cultivadas , Proteínas de Ligação a DNA/metabolismo , Exposição Ambiental , Expressão Gênica/efeitos da radiação , Humanos , Doses de Radiação , Ativação Transcricional/efeitos da radiação
17.
Phys Rev Lett ; 91(13): 132501, 2003 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-14525299

RESUMO

High-spin states in 135Nd were populated with the 110Pd(30Si,5n)135Nd reaction at a 30Si bombarding energy of 133 MeV. Two DeltaI=1 bands with close excitation energies and the same parity were observed. These bands are directly linked by DeltaI=1 and DeltaI=2 transitions. The chiral nature of these two bands is confirmed by comparison with three-dimensional tilted axis cranking calculations. This is the first observation of a three-quasiparticle chiral structure and establishes the primarily geometric nature of this phenomenon.

18.
Phys Rev Lett ; 88(12): 122501, 2002 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-11909451

RESUMO

We have determined the energy of the J(pi) = 1/2(+), T = 3/2 resonance in 32S(p,p) to be E(p) = 3374.7+/-0.8 keV. This disagrees with the previously accepted value of E(p) = 3370+/-1 keV by Abbondanno et al. [Nuovo Cimento 70A, 391 (1970)] and solves a problem raised by recent observations of unexpected deviations from the isobaric multiplet mass equation. This resonance is also important in calibrating the beta-delayed proton spectra from 33Ar and 32Ar, and our findings may modify previous conclusions.

19.
Tumour Biol ; 20(6): 341-6, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10567880

RESUMO

Few reports are available on mutations in the promoter of tumour suppressor genes like p16, WT1 and Rb in cancers. However, the involvement of p53 promoter in cancers is not clearly known. Further, methylation of CpG sites is a major contributor of mutations in several genes. So an attempt has been made to determine the mutation and methylation status of p53 promoter in breast tumours. Results have demonstrated absence of mutations and deletions in p53 promoter, leading us to conclude that mutation of p53 promoter is probably not a significant factor in breast tumorigenesis. Methylation analysis has shown that the CCGG sites in the p53 promoter are unmethylated unlike that of its exons. Further, it has been shown that there is no change in the methylation profile of the CCGG sites in breast tumours. However, such studies are to be conducted in different types of tumours to define the role of p53 promoter mutation and methylation in the process of tumorigenesis.


Assuntos
Neoplasias da Mama/genética , Metilação de DNA , Genes p53 , Mutação , Regiões Promotoras Genéticas , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Éxons , Feminino , Humanos , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Mapeamento por Restrição
20.
Mol Biol Rep ; 26(4): 223-30, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10634504

RESUMO

Different transcription factors activate and repress the p53 gene expression. Recently, a tissue specific binding of NF1/YY1 to p53 promoter has been reported and further, it has been demonstrated that NF1/YY1 activates p53 promoter activity. The deregulated expression of p53 appears to be a central feature of malignant transformation and the basis of this deregulation is not well defined. Hence, an attempt has been made to know the binding of NF1/YY1 to p53 promoter taking breast tumour as a model system. Results have indicated a differential binding of NF1 to p53 promoter and a depletion or low level of NF1 in majority of breast tumour samples. Further, a correlation between NF1 and p53 has indicated the presence of p53 RNA even without NF1. Hence it is assumed that p53 expression is not NF1-dependent in breast tumours. However, the results clearly demonstrate a deregulation of NF1 transcription factor in breast tumours.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Proteínas de Ligação a DNA/metabolismo , Genes p53/genética , Regiões Promotoras Genéticas/genética , Fatores de Transcrição/metabolismo , Pegada de DNA , Proteínas de Ligação a DNA/genética , Desoxirribonuclease I/metabolismo , Eletroforese/métodos , Regulação Neoplásica da Expressão Gênica , Humanos , Fatores de Transcrição NFI , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/genética , Proteína Supressora de Tumor p53/biossíntese , Proteína Supressora de Tumor p53/genética
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