RESUMO
The recently observed abnormal bifurcation of the double binding energy differences δV_{pn} between the odd-odd and even-even nuclei along the N=Z line from Ni to Rb has challenged the nuclear theories. To solve this problem, a shell-model-like approach based on the relativistic density functional theory is established, by treating simultaneously the neutron-neutron, proton-neutron, and proton-proton pairing correlations both microscopically and self-consistently. Without any ad hoc parameters, the calculated results well reproduce the observations, and the mechanism for this abnormal bifurcation is found to be due to the enhanced proton-neutron pairing correlations in the odd-odd N=Z nuclei, compared with the even-even ones. The present results provide an excellent interpretation for the abnormal δV_{pn} bifurcation, and provide a clear signal for the existence of the proton-neutron pairing correlations for nuclei close to the N=Z line.
RESUMO
The rotational properties of the transfermium nuclei are investigated in the full deformation space by implementing a shell-model-like approach in the cranking covariant density functional theory on a three-dimensional lattice, where the pairing correlations, deformations, and moments of inertia are treated in a microscopic and self-consistent way. The kinematic and dynamic moments of inertia of the rotational bands observed in the transfermium nuclei ^{252}No, ^{254}No, ^{254}Rf, and ^{256}Rf are well reproduced without any adjustable parameters using a well-determined universal density functional. It is found for the first time that the emergence of the octupole deformation should be responsible for the significantly different rotational behavior observed in ^{252}No and ^{254}No. The present results provide a microscopic solution to the long-standing puzzle on the rotational behavior in No isotopes, and highlight the risk of investigating only the hexacontetrapole (ß_{60}) deformation effects in rotating transfermium nuclei without considering the octupole deformation.
RESUMO
In the exothermic process of fission decay, an atomic nucleus splits into two or more independent fragments. Several aspects of nuclear fission are not properly understood, in particular the formation of the neck between the nascent fragments, and the subsequent mechanism of scission into two or more independent fragments. Using an implementation of time-dependent density functional theory, based on a relativistic energy density functional and including pairing correlations, we analyze the final phase of the process of induced fission of ^{240}Pu, and show that the timescale of neck formation coincides with the assembly of two α-like clusters. Because of its much larger binding energy, the dynamical synthesis of ^{4}He in the neck predominates over other light clusters, e.g., ^{3}H and ^{6}He. At the instant of scission the neck ruptures exactly between the two α-like clusters, which separate because of the Coulomb repulsion and are eventually absorbed by the two emerging fragments. The mechanism of light charged clusters formation at scission could also be linked to ternary fission.
RESUMO
The g factor of the 56 ns half-life isomeric state in ^{128}Cs has been measured using the time-differential perturbed angular distribution method. This state is the bandhead of the positive-parity chiral rotational band, which emerges when an unpaired proton, an unpaired neutron hole, and an even-even core are coupled such that their angular momentum vectors are aplanar (chiral configuration). g-factor measurements can give important information on the relative orientation of the three angular momentum vectors. The measured g factor g=+0.59(1) shows that there is an important contribution of the core rotation in the total angular momentum of the isomeric state. Moreover, a quantitative theoretical analysis supports the conclusion that the three angular momentum vectors lie almost in one plane, which suggests that the chiral configuration in ^{128}Cs demonstrated in previous works by characteristic patterns of electromagnetic transitions appears only above some value of the total nuclear spin.
RESUMO
Isomer shifts have been determined in ^{111-129}Cd by high-resolution laser spectroscopy at CERN-ISOLDE. The corresponding mean square charge-radii changes, from the 1/2^{+} and the 3/2^{+} ground states to the 11/2^{-} isomers, have been found to follow a distinct parabolic dependence as a function of the atomic mass number. Since the isomers have been previously associated with simplicity due to the linear mass dependence of their quadrupole moments, the regularity of the isomer shifts suggests a higher order of symmetry affecting the ground states in addition. A comprehensive description assuming nuclear deformation is found to accurately reproduce the radii differences in conjunction with the known quadrupole moments. This intuitive interpretation is supported by covariant density functional theory.
RESUMO
The anomalous rod shape in carbon isotopes has been investigated in the framework of the cranking covariant density functional theory, and two mechanisms to stabilize such a novel shape with respect to the bending motion, extreme spin, and isospin are simultaneously discussed for the first time in a self-consistent and microscopic way. By adding valence neutrons and rotating the system, we have found the mechanism stabilizing the rod shape; i.e., the σ orbitals (parallel to the symmetry axis) of the valence neutrons, important for the rod shape, are lowered by the rotation due to the Coriolis term. The spin and isospin effects enhance the stability of the rod-shaped configuration. This provides a strong hint that a rod shape could be realized in nuclei towards extreme spin and isospin.
RESUMO
Berberine (BBR) is a natural alkaloid with significant anti-tumor activity against many types of cancer cells. In this study, we investigated the molecular mechanisms employed by BBR to repress the proliferation and growth of skin squamous cell carcinoma A431 cells. Berberine was reported to inhibit the proliferation of A431 cells in a dose- and time-dependent manner and was observed to induce a series of biochemical events, including the loss of mitochondrial membrane potential, release of cytochrome-c to cytosol, induction of proteins of the Bcl-2 family and caspases, and the cleavage of poly(ADP)-ribose polymerase. This suggested its ability to induce apoptosis. The results of a wound healing test revealed that berberine inhibited the migration of A431 cells. Ezrin was transfected into A431 cells by RNA interference. The level of expression of Ezrin in the transfected A431 cells was observed to decrease with berberine treatment, which suggested that berberine might inhibit the invasion of A431 cells through Ezrin. The results of this study demonstrated that berberine could potentially inhibit proliferation, induce apoptosis, and inhibit the invasion of A431 cells.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Berberina/farmacologia , Proteínas do Citoesqueleto/genética , Células Epiteliais/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Caspase 3/genética , Caspase 3/metabolismo , Caspase 9/genética , Caspase 9/metabolismo , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citocromos c/genética , Citocromos c/metabolismo , Proteínas do Citoesqueleto/metabolismo , Relação Dose-Resposta a Droga , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Poli(ADP-Ribose) Polimerases/genética , Poli(ADP-Ribose) Polimerases/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais , Pele/efeitos dos fármacos , Pele/metabolismo , Pele/patologia , Transgenes , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismoRESUMO
IgA nephropathy (IgAN) diagnosis remains largely based upon immunohistologic detection of IgA- and IgG-containing glomerular deposits in renal mesangial cells, and little is known about the underlying pathogenic mechanisms. This study examines the putative contribution of B cell types, including the Breg type, to IgAN pathogenesis. Twenty-four patients with IgAN and proteinuria (Group A: <3.5 g/24 h, n = 13; Group B: >3.5 g/24 h, n = 11) and 10 healthy controls were enrolled. The frequencies of B cell subtypes in venous blood were measured by flow cytometry. Galactose-deficient IgA1 was measurement by ELISA. Needle biopsies were analysed by histology and immunofluorescence microscopy. Correlation between clinical features and B cell subtypes, including the regulatory B (Breg) cells, and Breg cell-derived immunomodulatory cytokine IL-10 was assessed by Spearman's rank correlation test. IgAN patients had significantly higher frequencies of CD27(+) CD19(+) , CD38(+) CD19(+) , CD86(+) CD19(+) and CD5(+) CD19(+) B cells than the healthy controls, but significantly lower levels of Breg cells and intracellular expression of IL-10 protein in the Breg subtype. Serum IgA concentration positively correlated with CD27(+) CD19(+) B cell frequency and negatively correlated with IL-10(+) Breg cell frequency in IgAN patients, and the percentage of CD19(+) CD5(+) CD1d(+) in CD19(+) cells was negatively correlated with the level of serum Gd-IgA1. Furthermore, the frequencies of CD19(+) CD38(+) and CD19(+) CD86(+) in the CD19(+) subpopulation negatively correlated with the estimated glomerular filtration rate of IgAN patients. Several of the CD19(+) B cell subtypes and the IL-10(+) Breg cells are differentially expressed in IgAN patients and may contribute to the disease pathogenesis.
Assuntos
Subpopulações de Linfócitos B/imunologia , Linfócitos B Reguladores/imunologia , Glomerulonefrite por IGA/imunologia , ADP-Ribosil Ciclase 1/imunologia , ADP-Ribosil Ciclase 1/metabolismo , Adolescente , Adulto , Idoso , Antígenos CD19/imunologia , Antígenos CD19/metabolismo , Subpopulações de Linfócitos B/metabolismo , Linfócitos B Reguladores/metabolismo , Antígeno B7-2/imunologia , Antígeno B7-2/metabolismo , Feminino , Citometria de Fluxo , Galactose/deficiência , Glomerulonefrite por IGA/sangue , Glomerulonefrite por IGA/metabolismo , Humanos , Imunoglobulina A/sangue , Interleucina-10/imunologia , Interleucina-10/metabolismo , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , Proteinúria/sangue , Proteinúria/imunologia , Proteinúria/metabolismo , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologia , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismo , Adulto JovemRESUMO
Three sets of chiral doublet band structures have been identified in the ^{103}Rh nucleus. The properties of the observed chiral doublet bands are in good agreement with theoretical results obtained using constrained covariant density functional theory and particle rotor model calculations. Two of them belong to an identical configuration and provide the first experimental evidence for a novel type of multiple chiral doublets, where an "excited" chiral doublet of a configuration is seen together with the "yrast" one. This observation shows that the chiral geometry in nuclei can be robust against the increase of the intrinsic excitation energy.
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.
RESUMO
Covariant density functional theory and the tilted axis cranking method are used to investigate antimagnetic rotation (AMR) in nuclei for the first time in a fully self-consistent and microscopic way. The experimental spectrum as well as the B(E2) values of the recently observed AMR band in (105)Cd are reproduced very well. This gives a further strong hint that AMR is realized in specific bands in nuclei.
RESUMO
Ovarian cancer is one of the most common causes of death from gynecologic tumors and is an important public health issue. Ghrelin is a recently discovered bioactive peptide that acts as a natural endogenous ligand of the growth hormone secretagogue receptor (GHSR). Several studies have identified the protective effects of ghrelin on the mammalian reproductive system. However, little research has been done on the effects of ghrelin on ovarian cancer cells, and the underlying mechanisms of these effects. We sought to understand the potential involvement of mitogen-activated protein kinases (MAPKs) in ghrelin-mediated inhibition of growth of the ovarian line HO-8910. We applied different concentrations of ghrelin and an inhibitor of the ghrelin receptor (D-Lys3-GHRP-6) to HO-8910 cells and observed the growth rate of cells and changes in phosphorylation of the MAPKs ERK1/2, JNK and p38. We discovered that ghrelin-induced apoptosis of HO-8910 cells was though phosphorylated ERK1/2, and that this phosphorylation (as well as p90rsk phosphorylation) was mediated by the GHSR. The ERK1/2 pathway is known to play an essential part in the ghrelin-mediated apoptosis of HO-8910 cells. Hence, our study suggests that ghrelin inhibits the growth of HO-8910 cells primarily through the GHSR/ERK pathway.
Assuntos
Regulação Neoplásica da Expressão Gênica/genética , Grelina/farmacologia , Sistema de Sinalização das MAP Quinases/fisiologia , Neoplasias Ovarianas/genética , Apoptose/efeitos dos fármacos , Feminino , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Pessoa de Meia-Idade , Oligopeptídeos/metabolismo , Neoplasias Ovarianas/metabolismo , Fosforilação/efeitos dos fármacos , Receptores de Grelina/antagonistas & inibidores , Receptores de Grelina/metabolismo , Células Tumorais CultivadasRESUMO
Ovarian cancer is one of the most common causes of death from gynecologic tumors and is an important public health issue. Ghrelin is a recently discovered bioactive peptide that acts as a natural endogenous ligand of the growth hormone secretagogue receptor (GHSR). Several studies have identified the protective effects of ghrelin on the mammalian reproductive system. However, little research has been done on the effects of ghrelin on ovarian cancer cells, and the underlying mechanisms of these effects. We sought to understand the potential involvement of mitogen-activated protein kinases (MAPKs) in ghrelin-mediated inhibition of growth of the ovarian line HO-8910. We applied different concentrations of ghrelin and an inhibitor of the ghrelin receptor (D-Lys3-GHRP-6) to HO-8910 cells and observed the growth rate of cells and changes in phosphorylation of the MAPKs ERK1/2, JNK and p38. We discovered that ghrelin-induced apoptosis of HO-8910 cells was though phosphorylated ERK1/2, and that this phosphorylation (as well as p90rsk phosphorylation) was mediated by the GHSR. The ERK1/2 pathway is known to play an essential part in the ghrelin-mediated apoptosis of HO-8910 cells. Hence, our study suggests that ghrelin inhibits the growth of HO-8910 cells primarily through the GHSR/ERK pathway.
Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Regulação Neoplásica da Expressão Gênica/genética , Grelina/farmacologia , Sistema de Sinalização das MAP Quinases/fisiologia , Neoplasias Ovarianas/genética , Apoptose/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Oligopeptídeos/metabolismo , Neoplasias Ovarianas/metabolismo , Fosforilação/efeitos dos fármacos , Receptores de Grelina/antagonistas & inibidores , Receptores de Grelina/metabolismo , Células Tumorais CultivadasRESUMO
This study compared the clinical results of surgical treatment of high complex anal fistula with a conventional seton and a new type of seton consisting of an elastic sheath and alloy core tube for irrigation of the wound track. A total of 438 patients were included in the study; 215 were treated with a conventional seton and 223 with the new-type seton. In patients treated with the new-type seton, the wound track was irrigated daily with 100 ml physiological saline, 100 ml hypertonic saline and 0.5 g metronidazole gel from the second postoperative day until seton removal. The new-type seton was associated with significant reductions in recurrence rate, length of stay and healing time compared with the conventional seton, but there were no significant differences in operation time or postoperative incontinence rates. It is concluded that the new-type seton with irrigating tube can improve the treatment of high complex anal fistula.
Assuntos
Fístula Retal/cirurgia , Técnicas de Sutura/instrumentação , Irrigação Terapêutica/instrumentação , Adolescente , Adulto , Incontinência Fecal/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Técnicas de Sutura/efeitos adversos , Irrigação Terapêutica/efeitos adversos , Resultado do Tratamento , Adulto JovemRESUMO
Thymosin-α(1) (TA(1)) has been shown to be effective treatment for chronic hepatitis B virus (HBV) infection. This study investigated the immune response after TA(1) monotherapy in 25 HBV e antigen (HBeAg)-positive patients randomized to receive either 1.6 mg active TA(1) (group A), 1.6 mg recombinant TA(1) (group B) or 3.2 mg recombinant TA(1) (group C) monotherapy for 52 weeks. The percentages of T-helper 1 (T(h)1) cytokine-producing T-cells (interleukin-2 [IL-2], interferon-γ [IFN-γ], tumour necrosis factor-α) and T(h)2 cytokine-producing T-cells (IL-4) were analysed using flow cytometry. In all patients treated with TA(1), cytokine levels and the proportion of peripheral blood mononuclear cells producing these cytokines were significantly increased, compared with baseline and healthy controls. The proportions of each cytokine-producing cell increased gradually over time and were restored to normal levels, and proportions of IFN-γ and IL-4-producing cells reached higher levels than in normal (healthy) controls. The results showed that treatment with TA(1) increased cytokine production, especially IFN-γ, and higher-dose TA(1) exhibited better efficacy against HBV, compared with other treatments studied.