Size and shape of Mott regions for fermionic atoms in a two-dimensional optical lattice

We investigate the harmonic-trap control of size and shape of Mott regions in the Fermi Hubbard model on a square optical lattice. The use of Lanczos diagonalization on clusters with twisted boundary conditions, followed by an average over 50-80 samples, drastically reduce finite-size effects in some ground state properties; calculations in the grand canonical ensemble together with a local-density approximation (LDA) allow us to simulate the radial density distribution. We have found that as the trap closes, the atomic cloud goes from a metallic state, to a Mott core, and to a Mott ring; the coverage of Mott atoms reaches a maximum at the core-ring transition. A `phase diagram' in terms of an effective density and the on-site repulsion is proposed, as a guide to maximize the Mott coverage. We also predict that the usual experimentally accessible quantities, the global compressibility and the average double occupancy (rather, its density derivative) display detectable signatures of the core-ring transition. Some spin correlation functions are also calculated, and predict the existence N\'eel ordering within Mott cores and rings.Comment: 5 pages, 6 figure

Numerical modeling of strain rate hardening effects on viscoplastic behavior of metallic materials

The main goal of the present work is to provide a finite strain elasticviscoplastic framework to numerically account for strain, strain rate hardening, and viscous effects in cold deformation of metallic materials. The aim is to provide a simple and robust numerical framework capable of modeling the main macroscopic behavior associated with high strain rate plastic deformation of metals. In order to account for strain rate hardening effects at finite strains, the hardening rule involves a rate dependent saturation hardening, and it accounts for linear hardening prevailing at latter deformation stages. The numerical formulation, finite element implementation, and constitutive modeling capabilities are assessed by means of decremental strain rate testing and constant strain rate loading followed by stress relaxation. The numerical results have demonstrated the overall framework can be an efficient numerical tool for simulation of plastic deformation processes where strain rate history effects have to be accounted for

Some numerical verification examples for plane stress elasto-viscoplasticity

This paper presents analytical, semi-analytical and numerical reference examples which can be employed for code verification of elasto-viscoplastic models under plane stress conditions. Mainly because of the overstress function the algorithms traditionally employed in elasto-plastic implementations must be rewritten to correctly impose the plane stress state along with the viscoplastic flow. The viscoplastic formulation presented here considers the strain-rate hardening effects by means of a hardening law that are assumed to have terms depending on the strain rate, which removed can represent a Voce type hardening. The proposed verification tests were employed for the numerical verification of an in-house implementation of the so-called stress-projected procedure inside the finite element method context. Although the focus of this paper is on the stressprojected algorithms the examples presented here can be employed for the verification of other algorithms intended to impose the plane stress state in viscoplasticit

Mono- and dicationic DABCO/Quinuclidine composed nanomaterials for the loading of steroidal drug: 32 factorial design and physicochemical characterization

Oil-in-water nanoemulsions (NEs) are considered a suitable nanotechnological approach to improve the eye-related bioavailability of lipophilic drugs. The potential of cationic NEs is prominent due to the electrostatic interaction that occurs between the positively charged droplets with the negatively charged mucins present in the tear film. This interaction offers prolonged NEs residence at the ocular surface, increasing the drug absorption. Triamcinolone acetonide (TA) is one of the first pharmacologic strategies applied as an intravitreal injection in the treatment of age-related macular degeneration (AMD). Newly synthesized quaternary derivatives of 1,4-diazabicyclo[2.2.2]octane (DABCO) and quinuclidine surfactants have been screened with the purpose to select the best compound to formulate long-term stable NEs that combine the best physicochemical properties for the loading of TA intended for ocular administration.This work was funded by the Portuguese Science and Technology Foundation (FCT) from the Ministry of Science and Technology (MCTES), European Social Fund (FSE) of EU, for the scholar ship SFRH/BD/130555/2017 granted to A. R. Fernandes, and for the projects UIDB/04469/2020 (CEB strategic fund) and UIDB/04033/2020 (CITAB), co-funded by European Funds (PRODER/COMPETE) and FEDER, under the Partnership Agreement PT2020.info:eu-repo/semantics/publishedVersio

DABCO-customized nanoemulsions: characterization, cell viability and genotoxicity in retinal pigmented epithelium and microglia cells

Quaternary derivatives of 1,4-diazabicyclo[2.2.2]octane (DABCO) and of quinuclidine surfactants were used to develop oil-in-water nanoemulsions with the purpose of selecting the best long-term stable nanoemulsion for the ocular administration of triamcinolone acetonide (TA). The combination of the best physicochemical properties (i.e., mean droplet size, polydispersity index, zeta potential, osmolality, viscoelastic properties, surface tension) was considered, together with the cell viability assays in ARPE-19 and HMC3 cell lines. Surfactants with cationic properties have been used to tailor the nanoemulsions surface for site-specific delivery of drugs to the ocular structure for the delivery of TA. They are tailored for the eye because they have cationic properties that interact with the anionic surface of the eye.Portuguese Science and Technology Foundation (FCT) from the Ministry of Science and Technology (MCTES), European Social Fund (FSE) of the EU, for the scholarship SFRH/BD/130555/2017 granted to A. R. Fernandes, and for the projects UIDB/04469/2020 (CEB strategic fund) and UIDB/04033/2020 (CITAB), co-funded by European Funds (PRODER/COMPETE) and FEDER, under the Partnership Agreement PT2020info:eu-repo/semantics/publishedVersio

Regulation of histone H2A.Z expression is mediated by sirtuin 1 in prostate cancer

Histone variants seem to play a major role in gene expression regulation. In prostate cancer, H2A.Z and its acetylated form are implicated in oncogenes’ upregulation. SIRT1, which may act either as tumor suppressor or oncogene, reduces H2A.Z levels in cardiomyocytes, via proteasome-mediated degradation, and this mechanism might be impaired in prostate cancer cells due to sirtuin 1 downregulation. Thus, we aimed to characterize the mechanisms underlying H2A.Z and SIRT1 deregulation in prostate carcinogenesis and how they interact. We found that H2AFZ and SIRT1 were up- and downregulated, respectively, at transcript level in primary prostate cancer and high-grade prostatic intraepithelial neoplasia compared to normal prostatic tissues. Induced SIRT1 overexpression in prostate cancer cell lines resulted in almost complete absence of H2A.Z. Inhibition of mTOR had a modest effect on H2A.Z levels, but proteasome inhibition prevented the marked reduction of H2A.Z due to sirtuin 1 overexpression. Prostate cancer cells exposed to epigenetic modifying drugs trichostatin A, alone or combined with 5-aza-2’-deoxycytidine, increased H2AFZ transcript, although with a concomitant decrease in protein levels. Conversely, SIRT1 transcript and protein levels increased after exposure. ChIP revealed an increase of activation marks within the TSS region for both genes. Remarkably, inhibition of sirtuin 1 with nicotinamide, increased H2A.Z levels, whereas activation of sirtuin 1 by resveratrol led to an abrupt decrease in H2A.Z. Finally, protein-ligation assay showed that exposure to epigenetic modifying drugs fostered the interaction between sirtuin 1 and H2A.Z. We concluded that sirtuin 1 and H2A.Z deregulation in prostate cancer are reciprocally related. Epigenetic mechanisms, mostly histone post-translational modifications, are likely involved and impair sirtuin 1-mediated downregulation of H2A.Z via proteasome-mediated degradation. Epigenetic modifying drugs in conjunction with enzymatic modulators are able to restore the normal functions of sirtuin 1 and might constitute relevant tools for targeted therapy of prostate cancer patient

Antimicrobial and Photoantimicrobial Activities of Chitosan/CNPPV Nanocomposites

Multidrug-resistant bacteria represent a global health and economic burden that urgently calls for new technologies to combat bacterial antimicrobial resistance. Here, we developed novel nanocomposites (NCPs) based on chitosan that display different degrees of acetylation (DAs), and conjugated polymer cyano-substituted poly(p-phenylene vinylene) (CNPPV) as an alternative approach to inactivate Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria. Chitosan's structure was confirmed through FT-Raman spectroscopy. Bactericidal and photobactericidal activities of NCPs were tested under dark and blue-light irradiation conditions, respectively. Hydrodynamic size and aqueous stability were determined by DLS, zeta potential (ZP) and time-domain NMR. TEM micrographs of NCPs were obtained, and their capacity of generating reactive oxygen species (ROS) under blue illumination was also characterized. Meaningful variations on ZP and relaxation time T2 confirmed successful physical attachment of chitosan/CNPPV. All NCPs exhibited a similar and shrunken spherical shape according to TEM. A lower DA is responsible for driving higher bactericidal performance alongside the synergistic effect from CNPPV, lower nanosized distribution profile and higher positive charged surface. ROS production was proportionally found in NCPs with and without CNPPV by decreasing the DA, leading to a remarkable photobactericidal effect under blue-light irradiation. Overall, our findings indicate that chitosan/CNPPV NCPs may constitute a valuable asset for the development of innovative strategies for inactivation and/or photoinactivation of bacteria. Keywords: photoantimicrobial activity; blue-light irradiation; chitosan; CNPPV; nanocomposites; E. coli; S. aureu

Projeto piloto para disseminar o conceito de propriedade intelectual: aplicado nas bibliotecas da Universidade Eestadual de Santa Ccruz e da Universidade Estadual de Feira de Santana, situadas na Bahia-Brasil

Buscando a inovação e ampliação dos serviços oferecidos às bibliotecas da Universidade Estadual de Feira de Santana e a Universidade Estadual de Santa Cruz, estão em fase de desenvolvimento de um projeto piloto que tem como objetivo disseminar o conceito de propriedade intelectual. Este apresentará uma metodologia ativa e participativa, tanto dos ministrantes do curso, assim como do público alvo. Para desenvolver o mesmo, formar-se-á uma equipe por profissionais a qual serão capacitadas e auxiliadas pelo Núcleo de Inovação Tecnológica (NIT).Seeking to innovate and expand the services offered to the libraries of the State University of Feira de Santana and the Santa Cruz State University, they are in the process of developing a pilot project that aims to disseminate the concept of intellectual property. This will present an active and participative methodology, both of the course's attendees, as well as the target audience. To develop the same, a team will be formed by professionals who will be trained and assisted by the Nucleus of Technological Innovation (NIT).Ibero-American Science and Technology Education Consortiu

Projeto piloto para disseminar o conceito de propriedade intelectual: aplicado nas bibliotecas da Universidade Eestadual de Santa Ccruz e da Universidade Estadual de Feira de Santana, situadas na Bahia-Brasil

Buscando a inovação e ampliação dos serviços oferecidos às bibliotecas da Universidade Estadual de Feira de Santana e a Universidade Estadual de Santa Cruz, estão em fase de desenvolvimento de um projeto piloto que tem como objetivo disseminar o conceito de propriedade intelectual. Este apresentará uma metodologia ativa e participativa, tanto dos ministrantes do curso, assim como do público alvo. Para desenvolver o mesmo, formar-se-á uma equipe por profissionais a qual serão capacitadas e auxiliadas pelo Núcleo de Inovação Tecnológica (NIT).Seeking to innovate and expand the services offered to the libraries of the State University of Feira de Santana and the Santa Cruz State University, they are in the process of developing a pilot project that aims to disseminate the concept of intellectual property. This will present an active and participative methodology, both of the course's attendees, as well as the target audience. To develop the same, a team will be formed by professionals who will be trained and assisted by the Nucleus of Technological Innovation (NIT).Ibero-American Science and Technology Education Consortiu

Projeto piloto para disseminar o conceito de propriedade intelectual: aplicado nas bibliotecas da Universidade Eestadual de Santa Ccruz e da Universidade Estadual de Feira de Santana, situadas na Bahia-Brasil

Buscando a inovação e ampliação dos serviços oferecidos às bibliotecas da Universidade Estadual de Feira de Santana e a Universidade Estadual de Santa Cruz, estão em fase de desenvolvimento de um projeto piloto que tem como objetivo disseminar o conceito de propriedade intelectual. Este apresentará uma metodologia ativa e participativa, tanto dos ministrantes do curso, assim como do público alvo. Para desenvolver o mesmo, formar-se-á uma equipe por profissionais a qual serão capacitadas e auxiliadas pelo Núcleo de Inovação Tecnológica (NIT).Seeking to innovate and expand the services offered to the libraries of the State University of Feira de Santana and the Santa Cruz State University, they are in the process of developing a pilot project that aims to disseminate the concept of intellectual property. This will present an active and participative methodology, both of the course's attendees, as well as the target audience. To develop the same, a team will be formed by professionals who will be trained and assisted by the Nucleus of Technological Innovation (NIT).Ibero-American Science and Technology Education Consortiu