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1.
J Phys Condens Matter ; 36(4)2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37802068

RESUMO

This work presents the results of a theoretical study of the electronic structure of two actinide metals,α-U andδ-Pu. We compare ourab-initioresults obtained with the recently developed self-consistent Vertex corrected GW approach with previously published experimental measurements such as photo-electron spectroscopy, for the occupied density of states, and bremsstralung isochromat spectroscopy (BIS) and inverse photo-electron spectroscopy (IPES), for the unoccupied density of states. Ourab-initioapproach includes all important relativistic effects (it is based on Dirac's equation) and it represents the first application of the Vertex corrected GW approach in the physics of actinides. Overall, our theoretical results are in good agreement with the experimental data, which supports the level of approximations which our theoretical method is based upon. By comparing our vertex corrected GW results with our results obtained with less sophisticated approaches (local density approximation and self-consistent GW) we differentiate the strength of correlation effects in Uranium and Plutonium. Also, our theoretical results allow us to elucidate the subtle differences between the previously published experimental BIS and IPES data on the unoccupied density of states inα-U.

2.
J Phys Condens Matter ; 33(48)2021 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-34488212

RESUMO

The question of spatial locality of electronic correlations beyond GW approximation is one of the central issues of the famous combination of GW and dynamical mean field theory, GW + DMFT. In this work, the above question is addressed directly (for the first time) by performing calculations with and without assumption of locality of the corresponding diagrams. For this purpose we use sc(GW + G3W2) approach where the higher order part (G3W2) is evaluated with fully momentum dependent Green's function G and screened interaction W and with 'local' variant, where the single site approximation is assumed for both G and W. For all three materials studied in this work (NiO,α-Ce, LiFeAs), we have found the spatial non-locality effects to be strong. For NiO and LiFeAs they, in fact, are decisive for the proper evaluation of vertex corrections. The results of this study have direct impact on our understanding of approximations made in practical implementations of GW + DMFT method, where all diagrams beyond GW (DMFT part) are assumed to be local. Taking into account the fact that the first diagrams beyond GW represent the most important contribution also in GW + DMFT calculations, we conclude that the basic assumption of GW + DMFT, namely the locality of diagrams evaluated in the DMFT part, is not as good as it is believed to be.

3.
Khirurgiia (Mosk) ; (9): 93-99, 2021.
Artigo em Russo | MEDLINE | ID: mdl-34480461

RESUMO

The authors report surgical treatment of a 59-year-old female with a giant solitary-fibrous tumor of the left hip. Previous excision of hip hemangioma was performed in 2016. Recurrent tumor with fast growth has occurred since 2018. The neoplasm consisted of 2 tumors connected by vascular structures. CT revealed soft tissue neoplasms in the upper third of the left thigh (anterior, medial and dorsal regions). Large tumors with an isthmus along the inner surface had tuberous contours and internal septa. The last ones and walls accumulated contrast agent. No structural damage to femoral muscles was observed. The patient underwent resection of tumor and vascular ligation (great saphenous vein and its tributaries along the anterior surface, arteries from the deep femoral artery system along the posterior surface of tumor). There were no early postoperative complications. There are no complaints within 6 month after surgery. There is no lower limb dysfunction.


Assuntos
Recidiva Local de Neoplasia , Tumores Fibrosos Solitários , Feminino , Humanos , Pessoa de Meia-Idade , Tumores Fibrosos Solitários/diagnóstico por imagem , Tumores Fibrosos Solitários/cirurgia
4.
J Phys Condens Matter ; 33(23)2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-33784637

RESUMO

The atomic forces formulation based on the Dirac-Kohn-Sham equation and the flexible (APW + lo/LAPW) + LO basis set is presented. The formulation was implemented in the code FlapwMBPT and allows a user to easily switch between different basis functions of the augmentation type (APW or LAPW) and between different kind of local orbitals. Similar to the work (2015Phys. Rev. B91035105), the implementation takes into account small discontinuities of the wave functions, density, and potential at the muffin-tin sphere boundaries. Applications to the materials with strong relativistic effects, such asα-uranium, PuCoGa5, and FePt, demonstrate robustness of the method. The comparison of the calculated forces with the ones obtained by numerical differentiation of electronic free energy shows close agreement with deviations about 0.1% or less.

5.
Khirurgiia (Mosk) ; (4): 72-76, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31120451

RESUMO

It is presented diagnosis and treatment of 53-year-old man with multiple echinococcosis of the lungs and mediastinum. The diagnosis was confirmed by chest CT. Patient previously underwent surgery for liver echinococcosis. Excision of echinococcosis lesions in the lungs and mediastinum was performed. Chest wall repair was made by using of pedicled flap from the right lateral surface of the thorax followed by donor site plasty by polypropylene mesh. There were no intraoperative complications. In the postoperative period, intermediate bronchus occlusion mas made by occluder due to persistent air output through the pleural drains. The device was removed after 4 days. The patient was discharged. Multidisciplinary approach is useful to achieve good results in these patients.


Assuntos
Equinococose/cirurgia , Doenças do Mediastino/cirurgia , Procedimentos Cirúrgicos Torácicos/efeitos adversos , Parede Torácica/cirurgia , Fístula Anastomótica/terapia , Brônquios/cirurgia , Equinococose/diagnóstico , Equinococose Pulmonar/diagnóstico , Equinococose Pulmonar/cirurgia , Humanos , Masculino , Doenças do Mediastino/diagnóstico , Pessoa de Meia-Idade , Implantação de Prótese/métodos , Recidiva , Retalhos Cirúrgicos , Procedimentos Cirúrgicos Torácicos/métodos , Tomografia Computadorizada por Raios X
6.
J Phys Condens Matter ; 27(31): 315603, 2015 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-26199232

RESUMO

Self-consistent solutions of Hedin's equations (HE) for the two-site Hubbard model (HM) have been studied. They have been found for three-point vertices of increasing complexity (Γ = 1 (GW approximation), Γ1 from the first-order perturbation theory, and the exact vertex Γ(E)). Comparison is made between the cases when an additional quasiparticle (QP) approximation for Green's functions is applied during the self-consistent iterative solving of HE and when QP approximation is not applied. The results obtained with the exact vertex are directly related to the present open question-which approximation is more advantageous for future implementations, GW + DMFT or QPGW + DMFT. It is shown that in a regime of strong correlations only the originally proposed GW + DMFT scheme is able to provide reliable results. Vertex corrections based on perturbation theory (PT) systematically improve the GW results when full self-consistency is applied. The application of QP self-consistency combined with PT vertex corrections shows similar problems to the case when the exact vertex is applied combined with QP sc. An analysis of Ward Identity violation is performed for all studied in this work's approximations and its relation to the general accuracy of the schemes used is provided.

7.
Appl Opt ; 50(28): 5499-502, 2011 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-22016217

RESUMO

Several approaches to the solution of the radiative transfer equation assume either Curtis-Godson average or linear change of the source function across grid segments. When such solutions are used for calculating limb radiances, the peak radiance response to the source function perturbation at tangent point i is displaced down to the tangent point i+1. This effect is explained through a geometric argument. Temperature profile retrievals performed by applying the ratio of signals at level i+1 for correcting temperature at level i demonstrate dramatic convergence acceleration of the iterative relaxation scheme.

8.
Bull Exp Biol Med ; 150(4): 485-9, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22268050

RESUMO

Ultrastructural characteristics of cell populations in the gastric tube mucosa were studied after plastic surgery for benign esophageal disease. The foveolar epithelium mainly consisted of secretory active mucocytes with small changes in cytoplasmic organelles. Functionally immature parietal cells and gland cells in the epithelium of fundal glands were characterized by atrophy and degeneration. Ultrastructural features of the epithelial compartment attest to adaptive cellular hypersecretion of the mucoid against the background of impaired acid production and enzyme secretion. The stromal compartment was characterized by low pinocytotic activity of endothelial cells in blood vessels and polymorphism of smooth muscle cells. Hypertrophic leiomyocytes were shown to dominate in the population of these cells. Some cells had signs of biosynthesis and reduction of filaments. Single leiomyocytes were degenerated. The observed ultrastructural modification of epithelial and connective cells can be interpreted as structural adaptation of the gastric transplant.


Assuntos
Epitélio/ultraestrutura , Esofagoplastia , Mucosa Gástrica/citologia , Mucosa Gástrica/ultraestrutura , Adulto , Células Endoteliais/citologia , Células Endoteliais/ultraestrutura , Esôfago/citologia , Esôfago/patologia , Esôfago/cirurgia , Feminino , Humanos , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/ultraestrutura , Células Parietais Gástricas/ultraestrutura
9.
Bull Exp Biol Med ; 149(5): 650-4, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21165410

RESUMO

Structural modifications of the gastric tube transplant were studied during the delayed period after esophagoplasty carried out for benign diseases of the esophagus. Adaptive and pathological reactions manifesting in atrophic and sclerotic changes in the mucosa formed the basis for transplant reorganization. The leading morphological markers were degeneration and hypersecretion of the foveolar epithelium, focal atrophy of the fundal glands with foci of pyloric metaplasia, hypertrophy and fibrosis of the muscle plate, and stromal sclerosis. Abundant polymorphonuclear infiltration of the mucosa with lymphoid follicular hyperplasia were observed in H. pylori contamination of the gastric transplant.


Assuntos
Órgãos Bioartificiais , Esofagoplastia , Esôfago/patologia , Mucosa Gástrica/patologia , Estômago/transplante , Adulto , Órgãos Bioartificiais/microbiologia , Feminino , Helicobacter pylori/isolamento & purificação , Humanos , Hiperplasia/patologia , Mucosa Intestinal/patologia , Masculino , Pessoa de Meia-Idade
10.
Biosens Bioelectron ; 20(6): 1177-84, 2004 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-15556364

RESUMO

By means of microgravimetry, UV-Vis spectroscopy and optic microscopy, sorption of pyridine, primary aliphatic amines and benzylamine by the Langmuir-Blodgett (LB) films of tetra-4-tert-butyl- and tetra-(3-nitro-5-tert-butyl)-substituted cobalt phthalocyanines (CoPc' and CoPc*, respectively) was studied over a broad concentration range. In general, sorption occurs as stepwise intercalation of the sorbate molecules into the supramolecular 3D structure of the phthalocyanine assembly followed by formation of the donor-acceptor complexes. Both intercalation depth and stoichiometry of the complexes are determined by the molecular structure of amines. The supramolecular factor allows discrimination between amines in air but not in aqueous solutions because of concurrent intercalation of water.


Assuntos
Indóis/química , Membranas Artificiais , Nanotubos/química , Compostos Organometálicos/química , Adsorção , Materiais Biocompatíveis/química , Substâncias Macromoleculares/química , Teste de Materiais , Conformação Molecular , Nanotubos/ultraestrutura , Tamanho da Partícula , Solubilidade
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