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1.
J Phys Condens Matter ; 36(31)2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38653258

RESUMO

Ferroic orders and their associated structural phase transitions are paramount in the understanding of a multitude of unconventional condensed matter phenomena. On this note, our investigation focuses on the polymorphic ferroelectric (FE) phase transitions of Copper(II) hydroxide, Cu(OH)2, considering an antiferromagnetic ground state. By employing the first-principles studies and group theory analysis, we have provided a systematic theoretical investigation of vibrational properties in the hypotheticalCmcmhigh-symmetry phase to unveil the symmetry-allowed ferroic phases. We identified a non-polar to polar (Cmc21) phase transition, in which the displacive transformation is primarily responsible for the phase change induced by twoB1u(i.e.Γ2-) phonon modes within the centrosymmetric phase. We also observed the existence of two polar structures with the same space group and different degrees of polarization (i.e.Ps= 3.06µC·cm-2andPs= 42.41µC·cm-2), emerging from the high symmetry non-polar structure. According to the structural analysis the FE order, of a geometric nature, is driven by theΓ2-mode in which the O- and H-sites displacements lead the polar distortion with a minor contribution from the Cu-sites. Interestingly, the 3d9:Cu2+Jahn-Teller distortion coupled with the orientational shifts of O-H atoms enhances the polarization.

2.
Ann Oncol ; 35(3): 293-301, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38092228

RESUMO

BACKGROUND: Sacituzumab govitecan (SG), a novel antibody-drug conjugate (ADC) targeting TROP2, is approved for pre-treated metastatic triple-negative breast cancer (mTNBC). We conducted an investigator-initiated clinical trial evaluating neoadjuvant (NA) SG (NCT04230109), and report primary results. PATIENTS AND METHODS: Participants with early-stage TNBC received NA SG for four cycles. The primary objective was to assess pathological complete response (pCR) rate in breast and lymph nodes (ypT0/isN0) to SG. Secondary objectives included overall response rate (ORR), safety, event-free survival (EFS), and predictive biomarkers. A response-guided approach was utilized, and subsequent systemic therapy decisions were at the discretion of the treating physician. RESULTS: From July 2020 to August 2021, 50 participants were enrolled (median age = 48.5 years; 13 clinical stage I disease, 26 stage II, 11 stage III). Forty-nine (98%) completed four cycles of SG. Overall, the pCR rate with SG alone was 30% [n = 15, 95% confidence interval (CI) 18% to 45%]. The ORR per RECIST V1.1 after SG alone was 64% (n = 32/50, 95% CI 77% to 98%). Higher Ki-67 and tumor-infiltrating lymphocytes (TILs) were predictive of pCR to SG (P = 0.007 for Ki-67 and 0.002 for TILs), while baseline TROP2 expression was not (P = 0.440). Common adverse events were nausea (82%), fatigue (76%), alopecia (76%), neutropenia (44%), and rash (48%). With a median follow-up time of 18.9 months (95% CI 16.3-21.9 months), the 2-year EFS for all participants was 95%. Among participants with a pCR with SG (n = 15), the 2-year EFS was 100%. CONCLUSIONS: In the first NA trial with an ADC in localized TNBC, SG demonstrated single-agent efficacy and feasibility of response-guided escalation/de-escalation. Further research on optimal duration of SG as well as NA combination strategies, including immunotherapy, are needed.


Assuntos
Anticorpos Monoclonais Humanizados , Camptotecina/análogos & derivados , Imunoconjugados , Neoplasias de Mama Triplo Negativas , Humanos , Pessoa de Meia-Idade , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia , Terapia Neoadjuvante , Antígeno Ki-67 , Antígenos de Neoplasias/genética , Imunoconjugados/efeitos adversos
3.
Phys Chem Chem Phys ; 25(21): 14992-14999, 2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37211874

RESUMO

Magnetic antiperovskites, having chiral noncollinear antiferromagnetic ordering, have shown remarkable properties that range from negative thermal expansion to anomalous Hall effects. Nevertheless, details on the electronic structure, related to the oxidation states and the octahedral center's site effects, are still scarce. Here, we show a theoretical study, based on first-principles calculations in the framework of density-functional theory (DFT), on the electronic properties associated with the nitrogen site effects on the structural, electronic, magnetic, and topological degrees of freedom. Thus, we show that the nitrogen vacancy increases the value of the anomalous Hall conductivity and retains the chiral Γ4g antiferromagnetic ordering. Moreover, we reveal, based on the Bader charges and the electronic structure analysis, the negative and positive oxidation states of the Ni- and Mn-sites, respectively. This is in agreement with the expected A3α+Bß-Xδ- oxidation states to satisfy charge neutrality in antiperovskites, but the negative charge is rare for transition metals. Finally, we extrapolate our findings on the oxidation states to several Mn3BN compounds, showing that the antiperovskite structure is an ideal platform to encounter negative oxidation states for metals sitting at the corner B-sites.

4.
Phys Chem Chem Phys ; 24(34): 20152-20163, 2022 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-35993971

RESUMO

Structural phase transitions drive several unconventional phenomena including some illustrious ferroic attributes which are relevant for technological advancements. On this note, we have investigated the ferroelastic structural transition of perovskite-type trigonal Ba2ZnTeO6 across Tc ∼ 150 K. With the help of Raman spectroscopy and density-functional theory (DFT)-based calculations, we report new intriguing observations associated with the phase transition in Ba2ZnTeO6. We observed the presence of a central peak (quasi-elastic Rayleigh profile), huge softening in the soft mode, hysteretic phonon behavior, and signatures of coexistent phases. The existence of a central peak in Ba2ZnTeO6 is manifested by a sharp rise in the intensity of the Rayleigh profile concomitant with the huge damping (or softening) of the soft mode (at ∼31 cm-1) near Tc, shedding light on the lattice dynamics during the phase transition. This is further corroborated by our phonon calculations that show that the soft mode (Eg) in the high-symmetry structure involving TeO6 octahedral rotation (with Ba and Zn translation) condenses into Ag and Bg modes in the C2/m low-symmetry phase. While most of the phonon bands split below Tc confirming the phase transition, we observed thermal hysteretic behavior of phonon modes, which signifies the first-order nature of the transition and the presence of coexisting phases as corroborated by our temperature-dependent X-ray diffraction and specific heat measurements.

5.
Phys Chem Chem Phys ; 23(32): 17142-17149, 2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34179906

RESUMO

Oxynitride perovskites of the type ABO2N have attracted considerable attention thanks to their potential ferroelectric behavior and tunable bandgap energy, making them ideal candidates for photocatalysis processes. Therefore, in order to shed light on the origin of their ferroelectric response, here we report a complete analysis of the structural and vibrational properties of SrNbO2N and SrTaO2N oxynitrides. By employing first-principles calculations, we analyzed the symmetry in-equivalent structures considering the experimentally reported parent I4/mcm space group (with a phase a0a0c- in Glazer's notation). Based on the I4/mcm reference within the 20-atoms unit-cell, we found and studied the ensemble of structures where different octahedral anionic orderings are allowed by symmetry. Thus, by exploring the vibrational landscape of the cis- and trans-type configuration structures and supported by the ionic eigendisplacements and the Born effective charges, we explained the mechanism responsible for the appearance of stable ferroelectric phases in both anionic orderings. The latter goes from covalent-driven in the trans-type ordering to the geometrically-driven in the cis-type configuration. Finally, we found in both cases that the biaxial xy epitaxial strain considerably enhances such ferroelectric response.

6.
Braz. j. biol ; 79(2): 311-320, Apr.-June 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-989459

RESUMO

Abstract The present paper addresses the feeding activity of Trachinotus cayennensis, collected in Lençóis Bay (1°18'S - 1°19'S; 44°51'W - 44°53'W) on the western coast of the state of Maranhão, Brazil. Sampling was conducted between June 2012 and June 2013 using driftnets with stretch mesh sizes from 95 to 100 mm. A total of 205 individuals (114 females and 91 males) were analyzed. Statistically significant differences in the sex ratio were found in June, September and December 2012. Food items were analyzed based on frequency of occurrence and volumetric method, with the subsequent calculation of the alimentary importance index. Three size groups were defined to determine possible ontogenetic changes in eating habits based on the size range of the individuals collected: I (˂ 29 cm), II (29.1 to 37.0) and III (≥ 37.1). Eleven food item categories were identified: mollusks, polychaetes, crustaceans, nematodes, insects, algae, bryozoans, ophiuroids, fishes, vegetal matter and sediments. The variety of items in the diet of T. cayennensis indicates considerable feeding plasticity and opportunistic behavior. Seasonal variations influenced the feeding pattern of the species, with greater feeding activity in the dry season. The considerable availability of resources in estuarine habitats of the western coast of Maranhão constitutes another factor that influences the feeding behavior of this species.


Resumo Atividade alimentar do pampo Trachinotus cayennensis (Cuvier 1832) (Perciformes, Carangidae) em estuários na costa ocidental do Maranhão, Brasil. O presente trabalho descreve a atividade alimentar do Trachinotus cayennensis , coletado na Baía de Lençóis (1°18'S - 1°19'S; 44°51'W - 44°53'W) na costa oeste do Maranhão. Amostragens foram realizadas entre junho de 2012 e junho de 2013, utilizando redes de emalhar à deriva com tamanho de malha de 95 a 100 mm. Foram analisados ​​205 indivíduos (114 fêmeas e 91 machos). Encontraram-se diferenças estatisticamente significativas na proporção sexual nos meses de junho, setembro e dezembro de 2012. Os itens alimentares foram analisados ​​com base na frequência de ocorrência e utilizando o método volumétrico, com o subsequente cálculo do índice de importância alimentar. Três grupos de tamanho foram definidos para determinar possíveis mudanças ontogenéticas nos hábitos alimentares com base na faixa de tamanho dos indivíduos coletados: I (˂ 29 cm), II (29,1 a 37,0) e III (≥ 37,1). Foram identificadas 11 categorias de alimentos: moluscos, poliquetas, crustáceos, nematoides, insetos, algas, briozoários, ophiuro, peixes, matéria vegetal e sedimentos. A variedade de itens na dieta de T. cayennensis indica uma plasticidade alimentar considerável e um comportamento oportunista. As variações sazonais influenciaram o padrão alimentar da espécie, com maior atividade de alimentação na estação seca. A considerável disponibilidade de recursos nos habitats estuarinos da costa oeste do Maranhão constitui outro fator que exerce influência sobre o comportamento alimentar desta espécie.


Assuntos
Animais , Masculino , Feminino , Perciformes/fisiologia , Comportamento Alimentar/fisiologia , Brasil , Estuários
7.
Braz J Biol ; 79(2): 311-320, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30133557

RESUMO

The present paper addresses the feeding activity of Trachinotus cayennensis, collected in Lençóis Bay (1°18'S - 1°19'S; 44°51'W - 44°53'W) on the western coast of the state of Maranhão, Brazil. Sampling was conducted between June 2012 and June 2013 using driftnets with stretch mesh sizes from 95 to 100 mm. A total of 205 individuals (114 females and 91 males) were analyzed. Statistically significant differences in the sex ratio were found in June, September and December 2012. Food items were analyzed based on frequency of occurrence and volumetric method, with the subsequent calculation of the alimentary importance index. Three size groups were defined to determine possible ontogenetic changes in eating habits based on the size range of the individuals collected: I (˂ 29 cm), II (29.1 to 37.0) and III (≥ 37.1). Eleven food item categories were identified: mollusks, polychaetes, crustaceans, nematodes, insects, algae, bryozoans, ophiuroids, fishes, vegetal matter and sediments. The variety of items in the diet of T. cayennensis indicates considerable feeding plasticity and opportunistic behavior. Seasonal variations influenced the feeding pattern of the species, with greater feeding activity in the dry season. The considerable availability of resources in estuarine habitats of the western coast of Maranhão constitutes another factor that influences the feeding behavior of this species.


Assuntos
Comportamento Alimentar/fisiologia , Perciformes/fisiologia , Animais , Brasil , Estuários , Feminino , Masculino
8.
Phys Rev Lett ; 121(11): 117601, 2018 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-30265112

RESUMO

Herewith, first-principles calculations based on density functional theory are used to describe the ideal magnetization reversal through polarization switching in BaCuF_{4} which, according to our results, could be accomplished close to room temperature. We also show that this ideal coupling is driven by a single soft mode that combines both polarization, and octahedral rotation. The later being directly coupled to the weak ferromagnetism of BaCuF_{4}. This, added to its strong Jahn-Teller distortion and its orbital ordering, makes this material a very appealing prototype for crystals in the ABX_{4} family for multifunctional applications. The described mechanism behaves ideally as it couples the ferroelectric and the magnetic properties naturally and it has not been reported previously.

9.
Sci Rep ; 8(1): 14313, 2018 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-30254275

RESUMO

The Mn valence in thin film La0.7Sr0.3MnO3 was studied as a function of film thickness in the range of 1-16 unit cells with a combination of non-destructive bulk and surface sensitive X-ray absorption spectroscopy techniques. Using a layer-by-layer valence model, it was found that while the bulk averaged valence hovers around its expected value of 3.3, a significant deviation occurs within several unit cells of the surface and interface. These results were supported by first principles calculations. The surface valence increases to up to Mn3.7+, whereas the interface valence reduces down to Mn2.5+. The change in valence from the expected bulk value is consistent with charge redistribution due to the polar discontinuity at the film-substrate interface. The comparison with theory employed here illustrates how this layer-by-layer valence evolves with film thickness and allows for a deeper understanding of the microscopic mechanisms at play in this effect. These results offer insight on how the two-dimensional electron gas is created in thin film oxide alloys and how the magnetic ordering is reduced with dimensionality.

10.
Phys Chem Chem Phys ; 20(26): 17799-17808, 2018 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-29922777

RESUMO

Geometrical and vibrational characterization of magnesium hydroxide was performed using density functional theory. Four possible crystal symmetries were explored: P3[combining macron] (No. 147, point group -3), C2/m (No. 12, point group 2), P3m1 (No. 156, point group 3m) and P3[combining macron]m1 (No. 164, point group -3m) which are the currently accepted geometries found in the literature. While a lot of work has been performed on Mg(OH)2, in particular for the P3[combining macron]m1 phase, there is still a debate on the observed ground state crystal structure and the anharmonic effects of the OH vibrations on the stabilization of the crystal structure. In particular, the stable positions of hydrogen are not yet defined precisely, which have implications in the crystal symmetry, the vibrational excitations, and the thermal stability. Previous work has assigned the P3[combining macron]m1 polymorph as the low energy phase, but it has also proposed that hydrogens are disordered and they could move from their symmetric position in the P3[combining macron]m1 structure towards P3[combining macron]. In this paper, we examine the stability of the proposed phases by using different descriptors. We compare the XRD patterns with reported experimental results, and a fair agreement is found. While harmonic vibrational analysis shows that most phases have imaginary modes at 0 K, anharmonic vibrational analysis indicates that at room temperature only the C2/m phase is stabilized, whereas at higher temperatures, other phases become thermally competitive.

11.
Clin Microbiol Infect ; 24 Suppl 2: S41-S52, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29426804

RESUMO

BACKGROUND: The present review is part of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Infections in Compromised Hosts (ESGICH) consensus document on the safety of targeted and biologic therapies. AIMS: To review, from an infectious diseases perspective, the safety profile of therapies targeting cell surface receptors and associated signaling pathways among cancer patients and to suggest preventive recommendations. SOURCES: Computer-based Medline searches with MeSH terms pertaining to each agent or therapeutic family. CONTENT: Vascular endothelial growth factor (VEGF)-targeted agents (bevacizumab and aflibercept) are associated with a meaningful increase in the risk of infection, likely due to drug-induced neutropaenia, although no clear benefit is expected from the universal use of anti-infective prophylaxis. VEGF tyrosine kinase inhibitors (i.e. sorafenib or sunitinib) do not seem to significantly affect host's susceptibility to infection, and universal anti-infective prophylaxis is not recommended either. Anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (cetuximab or panitumumab) induce neutropaenia and secondary skin and soft tissue infection in cases of severe papulopustular rash. Systemic antibiotics (doxycycline or minocycline) should be administered to prevent the latter complication, whereas no recommendation can be established on the benefit from antiviral, antifungal or anti-Pneumocystis prophylaxis. A lower risk of infection is reported for anti-ErbB2/HER2 monoclonal antibodies (trastuzumab and pertuzumab) and ErbB receptor tyrosine kinase inhibitors (including dual-EGFR/ErbB2 inhibitors such as lapatinib or neratinib) compared to conventional chemotherapy, presumably as a result of the decreased occurrence of drug-induced neutropaenia. IMPLICATIONS: With the exception of VEGF-targeted agents, the overall risk of infection associated with the reviewed therapies seems to be low.


Assuntos
Terapia Biológica/efeitos adversos , Doenças Transmissíveis/terapia , Terapia de Alvo Molecular/efeitos adversos , Transdução de Sinais/efeitos dos fármacos , Antineoplásicos Imunológicos/administração & dosagem , Antineoplásicos Imunológicos/efeitos adversos , Terapia Biológica/métodos , Ensaios Clínicos como Assunto , Controle de Doenças Transmissíveis , Consenso , Inibidores Enzimáticos/efeitos adversos , Inibidores Enzimáticos/uso terapêutico , Humanos , Hospedeiro Imunocomprometido , Terapia de Alvo Molecular/métodos , Receptores de Superfície Celular/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/efeitos dos fármacos
12.
Food Chem ; 246: 48-57, 2018 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-29291876

RESUMO

Oil extraction from green coffee seeds generates residual mass that is discarded by agribusiness and has not been previously studied. Bioactive secondary metabolites in coffee include antioxidant phenolic compounds, such as chlorogenic acids. Coffee seeds also contain caffeine, a pharmaceutically important methylxanthine. Here, we report the chemical profile, antioxidant activity, and cytotoxicity of hydroethanolic extracts of green Coffea arabica L. seed residue. The extracts of the green seeds and the residue have similar chemical profiles, containing the phenolic compounds chlorogenic acid and caffeine. Five monoacyl and three diacyl esters of trans-cinnamic acids and quinic acid were identified by ultra-performance liquid chromatography/electrospray ionization-quadruple time of flight mass spectrometry. The residue extract showed antioxidant potential in DPPH, ABTS, and pyranine assays and low cytotoxicity. Thus, coffee oil residue has great potential for use as a raw material in dietary supplements, cosmetic and pharmaceutical products, or as a source of bioactive compounds.


Assuntos
Antioxidantes/farmacologia , Coffea/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Sementes/química , Antioxidantes/química , Sulfonatos de Arila/química , Cafeína/análise , Linhagem Celular , Ácido Clorogênico/análise , Suplementos Nutricionais , Manipulação de Alimentos , Humanos , Fenóis/análise , Ácido Quínico/análise , Resíduos/análise , Xantinas/análise
13.
Neotrop Entomol ; 47(4): 433-439, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28600642

RESUMO

The larval parasitoid Cotesia flavipes (Cameron) (Hymenoptera: Braconidae) is an important biological control agent of the sugarcane borer, Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae). This exotic parasitoid has been mass reared for field release since its introduction in the 1970s. Insects are exchanged between labs or introduced from the field, but without basic studies or criteria. Thus, the objective of this study was to evaluate the genetic variability of insects from six Brazilian States (São Paulo, Minas Gerais, Paraná, Goiás, Maranhão, and Alagoas) using microsatellites. Analysis of five loci using at least 22 females from each location was performed. The molecular analysis made possible to verify that four out of the five loci analyzed were polymorphic. The allele frequencies of three loci were in agreement with the Hardy-Weinberg Equilibrium for all insects of all regions. It was also observed that five alleles were exclusively presented in only two loci. The variation among and within populations was 24.65 and 75.34%, respectively. The estimated shared genotypes between the C. flavipes individuals showed that K = 2 was the most likely number of genetic groups causing the current variation, as well as high shared genotypes from these groups of the individuals. Considering all the analyzed loci, the genetic differentiation was at a moderate level. We suggest a possible mixture of biological materials based on genetic distances and the degree of structuring displayed.


Assuntos
Variação Genética , Genética Populacional , Repetições de Microssatélites , Vespas/genética , Animais , Brasil , Feminino , Frequência do Gene , Loci Gênicos , Genótipo , Mariposas , Controle Biológico de Vetores , Saccharum
14.
Arq. bras. med. vet. zootec. (Online) ; 70(3): 731-740, maio-jun. 2018. tab, ilus
Artigo em Português | LILACS, VETINDEX | ID: biblio-911212

RESUMO

O estudo dos dados anatômicos é fundamental para possibilitar ao médico veterinário o reconhecimento de pequenas estruturas, como os nervos nos animais, oferecendo subsídio para construção do conhecimento do profissional principalmente em técnicas anestésicas e cirúrgicas. Para investigar e mapear os nervos do plexo braquial (nervo radial, nervo musculocutâneo, nervo ulnar, nervo mediano), nervo isquiático, nervo tibial, nervo femoral e os nervos para bloqueio paravertebral, foram utilizados um cadáver canino adulto, de peso aproximado de 8kg, e um cadáver de bezerro Holandês, de peso aproximado de 40kg. O mapeamento dos nervos é de grande importância, já que conhecer bem essas estruturas permite ao veterinário um bom desenvolvimento de suas atividades profissionais a fim de exercer funções mais complexas durante a anestesia e cirurgia veterinária, uma vez que, identificados os pontos de referência anatômicos, é possível trabalhar com mais clareza nas técnicas de bloqueios dos nervos periféricos.(AU)


Knowledge of animal anatomy is essential for the veterinarian to identify small structures such as nerves, thus providing a solid background for the professional especially for surgical and anesthetic techniques. To investigate and map the nerves of the brachial plexus (radial, musculocutaneous, ulnar, median), sciatic, tibial, femoral and the nerves for paravertebral blocking in bovine, embalmed specimens were used. One adult male dog weighing approximately 8kg and one 40kg male calf were used. Nerve mapping is fundamental due to its interdisciplinary nature, thus providing the veterinarian with a major improvement in his/her professional activities which permits allows one to perform complex tasks in anesthesia and veterinary surgery. Knowledge ofanatomical reference points increases clarity and precision in techniques involving peripheral nerve blocks.(AU)


Assuntos
Animais , Bovinos , Cães , Bovinos/anatomia & histologia , Cães/anatomia & histologia , Nervos Periféricos/diagnóstico por imagem , Anestesia Local/veterinária
15.
Sci Rep ; 7(1): 7182, 2017 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-28775384

RESUMO

The NaMnF3 fluoride-perovskite has been found, theoretically, to be ferroelectric under epitaxial strain becoming a promising alternative to conventional oxides for multiferroic applications. Nevertheless, this fluoroperovskite has not been experimentally verified to be ferroelectric so far. Here we report signatures of room temperature ferroelectricity observed in perovskite NaMnF3 thin films grown on SrTiO3. Using piezoresponse force microscopy, we studied the evolution of ferroelectric polarization in response to external and built-in electric fields. Density functional theory calculations were also performed to help understand the strong competition between ferroelectric and paraelectric phases as well as the profound influences of strain. These results, together with the magnetic order previously reported in the same material, pave the way to future multiferroic and magnetoelectric investigations in fluoroperovskites.

16.
Phys Rev Lett ; 116(11): 117202, 2016 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-27035320

RESUMO

In this study we show from first principles calculations the possibility to induce multiferroic and magnetoelectric functional properties in the Pnma NaMnF_{3} fluoroperovskite by means of epitaxial strain engineering. Surprisingly, we found a very strong nonlinear polarization-strain coupling that drives an atypical amplification of the ferroelectric polarization for either compression or expansion of the cell. This property is associated with a noncollinear antiferromagnetic ordering, which induces a weak ferromagnetism phase and makes the strained NaMnF_{3} fluoroperovskite multiferroic. The magnetoelectric response was calculated and it was found to be composed of linear and nonlinear components with amplitudes similar to the ones of Cr_{2}O_{3}. These findings show that it is possible to move the fluoride family toward functional applications with unique responses.

17.
Lupus ; 23(10): 1073-8, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25118052

RESUMO

Neuropsychiatric manifestations can be a serious complication of systemic lupus erythematosus, affecting nearly 56% of these patients. Frequently, acceptable clinical outcome is observed in neurolupus with immunosuppressive therapy. Different metabolites identified with MR spectroscopy may be associated with modifications in the natural history of this disease, specifically in the central nervous system. We report a case of neurolupus with progressive neurologic impairment despite aggressive immunosuppressive treatment. We describe clinical features, laboratory and MRI results, as well as characteristic findings on MR spectroscopy. Serial MRI identified atrophy of the left temporal lobe. MR spectroscopy showed an increase of myo-inositol/creatine ratio intensity, accompanied by a decrease of N-acetylaspartate/creatine ratio in both parietal white and gray matter. During follow-up, the patient developed progressive cognitive deficiency despite the intensification of therapy. Neurolupus manifestations are common and immunosuppressive treatment often avoids severe complications. Characteristic findings on MR spectroscopy may be useful for clinicians to determine poor prognosis and resistance to therapy.


Assuntos
Substância Cinzenta/metabolismo , Inositol/metabolismo , Vasculite Associada ao Lúpus do Sistema Nervoso Central/metabolismo , Lobo Parietal/metabolismo , Substância Branca/metabolismo , Atrofia , Biomarcadores/metabolismo , Cognição , Progressão da Doença , Feminino , Humanos , Imunossupressores/uso terapêutico , Vasculite Associada ao Lúpus do Sistema Nervoso Central/diagnóstico , Vasculite Associada ao Lúpus do Sistema Nervoso Central/tratamento farmacológico , Vasculite Associada ao Lúpus do Sistema Nervoso Central/psicologia , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Espectroscopia de Prótons por Ressonância Magnética , Lobo Temporal/patologia , Fatores de Tempo , Regulação para Cima
18.
J Oral Rehabil ; 41(5): 323-9, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24612404

RESUMO

Temporomandibular joint (TMJ) disorders are divided by the American Academy of Orofacial Pain into five categories. The most common ones are joint pain, as arthralgia and joint disorders, as disc displacements. An important clinical presentation of arthralgia is the painful tenderness to manual palpation or decreased pressure pain threshold (PPT). The authors conducted a study to determine the appropriate PPT value to discriminate asymptomatic TMJ individuals from those with moderate to severe arthralgia. Forty-nine individuals was evaluated and divided into groups: TMJ arthralgia, asymptomatic disc displacement and control group. Magnetic resonance images were obtained for all the groups, and algometry was performed on the TMJ lateral pole. Patients with arthralgia filled out a visual analogue scale (VAS). anova test with 1% of significance analysed the data. Specificity, sensitivity and ROC curve were also determined. Arthralgia group had significant lower PPT (mean of 1.07 kgf cm(-2) ) than the others. Asymptomatic disc displacement group (mean of 1.64 kgf cm(-2) ) has shown significant lower PPT than the control (mean of 2.35 kgf cm(-2) ). 89.66% of specificity and 70% of sensitivity were obtained when 1.36 kgf cm(-2) was applied to the TMJ (ROC area = 0.90). This value was considered to be the most appropriate to detected moderate to severe TMJ arthralgia. Indeed, the presence of disc displacement seems to significantly decrease PPT levels in asymptomatic subjects. The PPT value of 1.36 kgf cm(-2) can be used in the calibration procedures of the professionals involved with temporomandibular disorders and orofacial pain.


Assuntos
Artralgia/diagnóstico , Dor Facial/diagnóstico , Limiar da Dor , Transtornos da Articulação Temporomandibular/diagnóstico , Adolescente , Adulto , Análise de Variância , Artralgia/complicações , Artralgia/fisiopatologia , Brasil , Calibragem , Dor Facial/etiologia , Dor Facial/fisiopatologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Palpação , Valor Preditivo dos Testes , Pressão , Curva ROC , Amplitude de Movimento Articular , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Transtornos da Articulação Temporomandibular/complicações , Transtornos da Articulação Temporomandibular/fisiopatologia
19.
Genet Mol Res ; 12(4): 4586-94, 2013 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-24222234

RESUMO

This is the first study to examine the genetic diversity of mandacaru cactus (Cereus jamacaru P. DC.). Plants of spineless mandacaru are commonly found in gardens and parks of urban areas in northeastern Brazil. In addition to exploring their ornamental potential, morphological, and genetic characterization may contribute to the development of plant materials that can be used as a source of macromolecules of potential economic interest. The goal of this study was to estimate the genetic variability of spineless mandacaru accessions using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) molecular markers, and to characterize their morphology. Ten samples of newly emitted shoots with differentiated areolas and ribs were collected from each accession from the Cactaceous Germplasm Collection of Embrapa Agroindústria Tropical, in Fortaleza, CE. Shoot shape and aspects of spine primordia (presence, location, grouping, and size of spines) were evaluated. The morphological analysis showed that the spineless mandacaru presented spine primordia. Twenty-six RAPD and 15 ISSR primers were polymorphic. A total of 262 markers were obtained, 129 of which were polymorphic. The average polymorphism of ISSR markers was higher than that of RAPD markers. The dendrograms for both analyses showed differentiation between accessions. Nevertheless, the molecular markers detected higher levels of diversity and a different pattern of diversity than those found using morphological markers. The molecular results revealed significant genetic variability both within and between groups.


Assuntos
Cactaceae/genética , Repetições de Microssatélites , Polimorfismo Genético , Cactaceae/anatomia & histologia , Genes de Plantas , Marcadores Genéticos , Filogenia , Análise de Sequência de DNA
20.
PPAR Res ; 2013: 401274, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23983677

RESUMO

Obesity and type 2 diabetes mellitus (T2D) are two major public health problems that have motivated the scientific community to investigate the high contribution of genetic factors to these disorders. The peroxisome proliferator activated by gamma 2 (PPARγ2) plays an important role in the lipid metabolism. Since PPARγ2 is expressed mainly in adipose tissue, a moderate reduction of its activity influences the sensitivity to insulin, diabetes, and other metabolic parameters. The present study aims to contribute to the elucidation of the impact of the Pro(12)Ala polymorphism associated with T2D and obesity through a meta-analysis study of the literature that included approximately 11500 individuals, from which 3870 were obese and 7625 were diabetic. Statistical evidence supports protective effect in T2D of polymorphism Pro(12)Ala of PPARγ2 (OR = 0.702 with 95% CI: 0.622; 0.791, P < 0.01). Conversely the same polymorphism Pro(12)Ala of PPARγ2 seems to favor obesity since 1.196 more chance than nonobese was found (OR = 1.196 with 95% CI: 1.009; 1.417, P < 0.004). Our results suggest that Pro(12)Ala polymorphism enhances both adipogenic and antidiabetogenic physiological role of PPARγ. Does Pro(12)Ala polymorphism represent an evolutionary step towards the stabilization of the molecular function of PPARγ transcription factor signaling pathway?

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