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1.
Nat Mater ; 23(7): 912-919, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38605196

RESUMO

Polar metals have recently garnered increasing interest because of their promising functionalities. Here we report the experimental realization of an intrinsic coexisting ferromagnetism, polar distortion and metallicity in quasi-two-dimensional Ca3Co3O8. This material crystallizes with alternating stacking of oxygen tetrahedral CoO4 monolayers and octahedral CoO6 bilayers. The ferromagnetic metallic state is confined within the quasi-two-dimensional CoO6 layers, and the broken inversion symmetry arises simultaneously from the Co displacements. The breaking of both spatial-inversion and time-reversal symmetries, along with their strong coupling, gives rise to an intrinsic magnetochiral anisotropy with exotic magnetic field-free non-reciprocal electrical resistivity. An extraordinarily robust topological Hall effect persists over a broad temperature-magnetic field phase space, arising from dipole-induced Rashba spin-orbit coupling. Our work not only provides a rich platform to explore the coupling between polarity and magnetism in a metallic system, with extensive potential applications, but also defines a novel design strategy to access exotic correlated electronic states.

2.
Phys Chem Chem Phys ; 26(8): 6717-6725, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38321974

RESUMO

Here we present a detailed analysis of the structure, bonding character, and electronic structure of anti-anatase ß-Mo2N using density functional theory calculations. We analyze the crystal orbital Hamilton populations, phonon band structure, and electronic structure calculations to explain its low energy transport behavior. We further examine the electronic structures of (anti-)rutile and (anti-)anatase M3-nXn (X = N,O; n = 1,2) M = Ti and Mo nitrides and oxides to show that the atomic structure of anti-anatase leads to metallic behavior independent of the metal and ligand chemistry. Finally, we assess whether these anti-anatase compounds are viable electrides using electron density maps and electron localization functions. Our work shows anti-structures of known binary compounds can expand the phase space of available metallic ceramics beyond layered, hexagonal carbides and nitrides, e.g., Mn+1An (MAX) where n = 1-4.

3.
Stud Health Technol Inform ; 310: 1458-1459, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38269695

RESUMO

Natural Language Processing can be used to identify opioid use disorder in patients from clinical text1. We annotate a corpus of clinical text for mentions of concepts associated with unhealthy use of opiates including concept modifiers such as negation, subject, uncertainty, relation to document time and illicit use.


Assuntos
Processamento de Linguagem Natural , Transtornos Relacionados ao Uso de Opioides , Humanos , Transtornos Relacionados ao Uso de Opioides/epidemiologia , Incerteza
4.
J Exp Child Psychol ; 236: 105742, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37481987

RESUMO

Previous research suggests that mnemonic discrimination (i.e., the ability to discriminate between previously encountered and novel stimuli even when they are highly similar) improves substantially during childhood. To further understand the development of mnemonic discrimination during childhood, the current study had 4-year-old children, 6-year-old children, and young adults complete the forced-choice Mnemonic Similarity Task (MST). The forced-choice MST offers a significant advantage in the context of developmental research because it is not sensitive to age-related differences in response criteria and includes three test formats that are theorized to be supported by different cognitive processes. A target (i.e., a previously encountered item) is paired with either a novel item (A-X), a corresponding lure (A-A'; i.e., an item mnemonically similar to the target), or a non-corresponding lure (A-B'; i.e., an item mnemonically similar to a different previously encoded item). We observed that 4-year-olds performed more poorly than 6-year-olds on the A-X and A-A' test formats, whereas both 4- and 6-year-olds performed more poorly than young adults on the A-B' test format. The MINERVA 2.2 computational model effectively accounted for these age-related differences. The model suggested that 4-year-olds have a lower learning rate (i.e., probability of encoding stimulus features) than 6-year-olds and young adults and that both 4- and 6-year-olds have greater encoding variability than young adults. These findings provide new insight into possible mechanisms underlying memory development during childhood and serve as the basis for multiple avenues of future research.


Assuntos
Desenvolvimento Infantil , Comportamento de Escolha , Aprendizagem por Discriminação , Psicologia da Criança , Humanos , Pré-Escolar , Criança , Adulto Jovem , Tempo de Reação , Masculino , Feminino , Modelos Psicológicos , Envelhecimento
5.
J Food Compost Anal ; 1182023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36844472

RESUMO

Euterpe oleracea Mart., commonly known as açaí, is a fruit that grows on a palm tree native to the Amazon region. Quantitation of bioactive constituents is a crucial preliminary step before utilizing extracts for biological assays so they may be normalized and administered according to a specific constituent concentration. Açaí has four main anthocyanin analytes: cyanidin 3-glucoside, cyanidin 3-sambubioside, cyanidin 3-rutinoside, and peonidin 3-rutinoside. This is the first comparison of açaí anthocyanin profiles between fresh fruits, processed powders, and botanical dietary supplement capsules. The materials examined shared a similar anthocyanin profile, with cyanidin 3-rutinoside being the most abundant (0.380 ± 0.006 - 15.1 ± 0.01 mg/g), followed by cyanidin 3-glucoside (0.0988 ± 0.0031 - 8.95 ± 0.01 mg/g). Among the botanical dietary supplement capsules, the two formulations varied greatly in anthocyanin concentration despite both being aqueous extracts (0.650 ± 0.011 - 0.924 ± 0.010 mg/g versus 1.23 ± 0.01 - 1.27 ± 0.02 mg/g). Previous LC-MS methods range from 35-120 min per injection, while we report a 10 min quantitative method for analysis of anthocyanins in various açaí materials that is fast, reproducible, and accurate. The method produced is useful to assure the quality, efficacy and safety of food and dietary supplement materials containing açaí.

6.
J Phys Chem Lett ; 13(26): 6236-6243, 2022 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-35770969

RESUMO

We formulate the maximum driving force (MDF) parameter as a descriptor to capture the thermodynamic stability of aqueous surface scale creation over a range of environmental conditions. We use free energies of formation, ΔfG's, sourced from high-throughput density functional theory (DFT) calculations and experimental databases to compute the maximum driving force for a range of materials, including oxides and hydroxides of varying compositions. We show how to use the MDF to describe trends in the aqueous corrosion of nickel thin films determined from experimental linear sweep voltammetry data. We also show how to account for subsurface oxidation behavior using depth-dependent effective chemical potentials. We anticipate this approach will increase the overall understanding of oxide formation on chemically complex multielement alloys, where competing oxide phases can form during transient aqueous corrosion.

7.
J Am Chem Soc ; 144(6): 2569-2579, 2022 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-35113569

RESUMO

Although BiAgOSe, an analogue of a well-studied thermoelectric material BiCuOSe, is thermodynamically stable, its synthesis is complicated by the low driving force of formation from the stable binary and ternary intermediates. Here we have developed a "subtraction strategy" to suppress byproducts and produce pure phase BiAgOSe using hydrothermal methods. Electronic structure calculations and optical characterization show that BiAgOSe is an indirect bandgap semiconductor with a bandgap of 0.95 eV. The prepared sample exhibits lower lattice thermal conductivities (0.61 W·m-1·K-1 at room temperature and 0.35 W·m-1·K-1 at 650 K) than BiCuOSe. Lattice dynamical simulations and variable temperature diffraction measurements demonstrate that the low lattice thermal conductivity arises from both the low sound velocity and high phonon-phonon scattering rates in BiAgOSe. These in turn result primarily from the soft Ag-Se bonds in the edge-sharing AgSe4 tetrahedra and large sublattice mismatch between the quasi-two-dimensional [Bi2O2]2+ and [Ag2Se2]2- layers. These results highlight the advantages of manipulating the chemistry of homoleptic polyhedra in heteroanionic compounds for electronic structure and phonon transport control.

8.
J Pediatr ; 227: 231-238.e14, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32717230

RESUMO

OBJECTIVE: To investigate the frequency of genetic diagnoses among infants with critical congenital heart disease (CHD) using a comprehensive cardiovascular genetics approach and to identify genotype-phenotype correlations. STUDY DESIGN: A retrospective chart review of patients evaluated by cardiovascular genetics in a pediatric cardiac intensive care unit from 2010 to 2015 was performed. Infants with CHD who were <1 month of age were included. CHD was classified using structured phenotype definitions. Cardiac and noncardiac phenotypes were tested for associations with abnormal genetic testing using χ1 and Fisher exact tests. RESULTS: Genetic evaluation was completed in 293 infants with CHD, of whom 213 had isolated congenital heart disease (iCHD) and 80 had multiple congenital anomalies. Overall, the yield of abnormal genetic testing was 26%. The multiple congenital anomalies cohort had a greater yield of genetic testing (39%) than the iCHD cohort (20%) (OR 2.7). Using a non-hierarchical CHD classification and excluding 22q11.2 deletion and common aneuploidies, right ventricular obstructive defects were associated with abnormal genetic testing (P = .0005). Extracardiac features associated with abnormal genetic testing included ear, nose, and throat (P = .003) and brain (P = .0001) abnormalities. A diagnosis of small for gestational age or intrauterine growth retardation also was associated with abnormal genetic testing (P = .0061), as was presence of dysmorphic features (P = .0033, OR 3.5). Infants without dysmorphia with iCHD or multiple congenital anomalies had similar frequencies of abnormal genetic testing. CONCLUSIONS: The present study provides evidence to support a comprehensive cardiovascular genetics approach in evaluating infants with critical CHD while also identifying important genotype-phenotype considerations.


Assuntos
Estudos de Associação Genética , Cardiopatias Congênitas/diagnóstico , Cardiopatias Congênitas/genética , Estado Terminal , Feminino , Testes Genéticos , Humanos , Recém-Nascido , Masculino , Estudos Retrospectivos
9.
Phys Rev Lett ; 123(23): 236402, 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31868440

RESUMO

Using a first-principles approach, we design the heteroanionic oxynitride MoON to exhibit a first-order isosymmetric thermally activated Peierls-type metal-insulator transition (MIT). We identify a ground state insulating phase (α-MoON) with monoclinic Pc symmetry and a metastable high temperature metallic phase (ß-MoON) of equivalent symmetry. We find that ordered fac-MoO_{3}N_{3} octahedra with edge and corner connectivity stabilize the twisted Mo-Mo dimers present in the α phase, which activate the MIT through electron localization within the 4d a_{1g} manifold. By analyzing the temperature dependence of the soft zone-boundary instability driving the MIT, we estimate an ordering temperature T_{MIT}∼900 K. Our work shows that electronic transitions can be designed by exploiting multiple anions, and heteroanionic materials could offer new insights into the microscopic electron-lattice interactions governing unresolved transitions in homoanionic oxides.

10.
Hum Mol Genet ; 19(22): 4353-72, 2010 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-20739296

RESUMO

Abnormalities in the development of enteric neural crest-derived progenitors (ENPs) that generate the enteric nervous system (ENS) can lead to aganglionosis in a variable portion of the distal gastrointestinal tract. Cumulative evidence suggests that variation of aganglionosis is due to gene interactions that modulate the ability of ENPs to populate the intestine; however, the developmental processes underlying this effect are unknown. We hypothesized that differences in enteric ganglion deficits could be attributable to the effects of genetic background on early developmental processes, including migration, proliferation, or lineage divergence. Developmental processes were investigated in congenic Sox10(Dom) mice, an established Hirschsprung disease (HSCR) model, on distinct inbred backgrounds, C57BL/6J (B6) and C3HeB/FeJ (C3Fe). Immuno-staining on whole-mount fetal gut tissue and dissociated cell suspensions was used to assess migration and proliferation. Flow cytometry utilizing the cell surface markers p75 and HNK-1 was used to isolate live ENPs for analysis of developmental potential. Frequency of ENPs was reduced in Sox10(Dom) embryos relative to wild-type embryos, but was unaffected by genetic background. Both migration and developmental potential of ENPs in Sox10(Dom) embryos were altered by inbred strain background with the most highly significant differences seen for developmental potential between strains and genotypes. In vivo imaging of fetal ENPs and postnatal ganglia demonstrates that altered lineage divergence impacts ganglia in the proximal intestine. Our analysis demonstrates that genetic background alters early ENS development and suggests that abnormalities in lineage diversification can shift the proportions of ENP populations and thus may contribute to ENS deficiencies in vivo.


Assuntos
Sistema Nervoso Entérico/embriologia , Doença de Hirschsprung/genética , Crista Neural/citologia , Fatores de Transcrição SOXE/genética , Células-Tronco/citologia , Animais , Antígenos CD57/metabolismo , Modelos Animais de Doenças , Sistema Nervoso Entérico/citologia , Sistema Nervoso Entérico/metabolismo , Gânglios/embriologia , Gânglios/patologia , Doença de Hirschsprung/embriologia , Doença de Hirschsprung/metabolismo , Humanos , Imuno-Histoquímica , Intestino Delgado/metabolismo , Intestino Delgado/patologia , Intestinos/citologia , Intestinos/embriologia , Camundongos , Camundongos Congênicos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Mutação , Crista Neural/embriologia , Especificidade da Espécie
11.
Pediatr Res ; 52(3): 437-42, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12193681

RESUMO

Exposure of rats and mice to hyperoxia decreases lung coenzyme A (CoASH) contents, with a decrease of 50% observed in adult male Fischer-344 rats exposed to >95% O(2) for 48 h. Decreases in lung CoASH levels are not accompanied by increases in contents of the mixed glutathione disulfide of CoA, as might be expected of a primary oxidative stress on CoASH status. Animals exposed to hyperoxia exhibit decreased food intake, and the present studies were to test the hypothesis that fasting would decrease lung CoASH contents, thereby suggesting a mechanism for the effects of hyperoxia. Adult male Fischer-344 rats were examined after 0, 24, or 48 h of fasting (n = 5, 6, and 6, respectively). Fasting for 24 or 48 h did not affect lung CoASH levels or lung weights, despite 6 and 12% losses in body weight. Lung glutathione concentrations (nanomoles per gram of tissue) and contents (nanomoles per whole organ) and glutathione disulfide contents were 10 to 20% lower in rats fasted for 48 h than in fed rats. Liver weights and glutathione and glutathione disulfide contents and concentrations were 30 to 70% lower in rats fasted for 24 or 48 h than in fed rats. Hepatic CoASH concentrations increased during fasting, but hepatic contents of CoASH remained remarkably constant. Liver protein contents (milligrams of protein per whole organ) decreased after 24 and 48 h of fasting, but protein concentrations (milligrams of protein per gram of tissue) were higher in rats fasted 48 h than in fed rats. Overall, glutathione, glutathione disulfide, and protein contents in liver and skeletal muscle decreased with fasting, but significant changes in CoASH contents were not observed. Diminished food intake in animals does not explain the effects of hyperoxia on lung CoASH contents. CoASH and derived thioesters participate in many cellular functions, and if depletion of lung CoASH during hyperoxia proves to be relevant to mechanisms of lung injury, support of mechanisms needed to sustain CoA levels could be helpful in prematurely born infants and in adults.


Assuntos
Coenzima A/metabolismo , Jejum/fisiologia , Pulmão/metabolismo , Oxigênio/metabolismo , Alanina Transaminase/sangue , Animais , Nitrogênio da Ureia Sanguínea , Peso Corporal , Coenzima A/química , Creatinina/sangue , Glutationa/química , Glutationa/metabolismo , Humanos , Fígado/metabolismo , Masculino , Músculo Esquelético/metabolismo , Ratos , Ratos Endogâmicos F344 , Distribuição Tecidual
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