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1.
Sci Rep ; 13(1): 3847, 2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36890187

RESUMO

Interface engineering in complex oxide superlattices is a growing field, enabling manipulation of the exceptional properties of these materials, and also providing access to new phases and emergent physical phenomena. Here we demonstrate how interfacial interactions can induce a complex charge and spin structure in a bulk paramagnetic material. We investigate a superlattice (SLs) consisting of paramagnetic LaNiO3 (LNO) and highly spin-polarized ferromagnetic La2/3Ca1/3MnO3 (LCMO), grown on SrTiO3 (001) substrate. We observed emerging magnetism in LNO through an exchange bias mechanism at the interfaces in X-ray resonant magnetic reflectivity. We find non-symmetric interface induced magnetization profiles in LNO and LCMO which we relate to a periodic complex charge and spin superstructure. High resolution scanning transmission electron microscopy images reveal that the upper and lower interfaces exhibit no significant structural variations. The different long range magnetic order emerging in LNO layers demonstrates the enormous potential of interfacial reconstruction as a tool for tailored electronic properties.

2.
Artigo em Inglês | MEDLINE | ID: mdl-34769539

RESUMO

This study explores the level and frequency of anxiety about COVID-19 infection in some Middle Eastern countries, and differences in this anxiety by country, gender, workplace, and social status. Another aim was to identify the predictive power of anxiety about COVID-19 infection, daily smartphone use hours, and age in smartphone addiction. The participants were 651 males and females from Jordan, Saudi Arabia, the United Arab Emirates, and Egypt. The participants' ages ranged between 18 and 73 years (M 33.36, SD = 10.69). A questionnaire developed by the authors was used to examine anxiety about COVID-19 infection. Furthermore, the Italian Smartphone Addiction Inventory was used after being translated, adapted, and validated for the purposes of the present study. The results revealed that the percentages of participants with high, average, and low anxiety about COVID-19 infection were 10.3%, 37.3%, and 52.4%, respectively. The mean scores of anxiety about COVID-19 infection in the four countries were average: Egypt (M = 2.655), Saudi Arabia (M = 2.458), the United Arab Emirates (M = 2.413), and Jordan (M = 2.336). Significant differences in anxiety about COVID-19 infection were found between Egypt and Jordan, in favor of Egypt. Significant gender differences were found in favor of females in the Jordanian and Egyptian samples, and in favor of males in the Emirati sample. No significant differences were found regarding workplace and social status. The results also revealed a significant positive relationship between anxiety about COVID-19 infection, daily smartphone use hours, and age on the one hand, and smartphone addiction on the other. The strongest predictor of smartphone addiction was anxiety about COVID-19 infection, followed by daily use hours. Age did not significantly contribute to the prediction of smartphone addiction. The study findings shed light on the psychological health and cognitive aspects of anxiety about COVID-19 infection and its relation to smartphone addiction.


Assuntos
Comportamento Aditivo , COVID-19 , Adolescente , Adulto , Idoso , Ansiedade/epidemiologia , Comportamento Aditivo/epidemiologia , Demografia , Feminino , Humanos , Transtorno de Adição à Internet , Masculino , Pessoa de Meia-Idade , SARS-CoV-2 , Smartphone , Adulto Jovem
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 136 Pt C: 1698-701, 2015 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-25467659

RESUMO

During illumination of the MgB2:Cr2O3 films it was established substantial spectral shift of the infrared spectra in the vicinity of 20-50cm(-1). The excitations were performed by nanosecond Er:glass laser operating at 1.54µm and by microsecond 10.6µm CO2 laser. The spectral shifts of the IR maxima were in opposite spectral directions for the two types of lasers. This one observed difference correlates well with spectral shift of their critical temperatures. The possible explanation is given by performance of DFT calculations of the charge density redistribution and the time kinetics of the photovoltaic response. To understand the kinetics of the photoinduced processes the time kinetics of photoresponse was done for the particular laser wavelengths.

4.
Nat Mater ; 11(8): 675-81, 2012 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-22797829

RESUMO

The electron-phonon interaction is of central importance for the electrical and thermal properties of solids, and its influence on superconductivity, colossal magnetoresistance and other many-body phenomena in correlated-electron materials is the subject of intense research at present. However, the non-local nature of the interactions between valence electrons and lattice ions, often compounded by a plethora of vibrational modes, presents formidable challenges for attempts to experimentally control and theoretically describe the physical properties of complex materials. Here we report a Raman scattering study of the lattice dynamics in superlattices of the high-temperature superconductor YBa(2)Cu(3)O(7) (YBCO) and the colossal-magnetoresistance compound La(2/3)Ca(1/3)MnO(3) that suggests a new approach to this problem. We find that a rotational mode of the MnO(6) octahedra in La(2/3)Ca(1/3)MnO(3) experiences pronounced superconductivity-induced line-shape anomalies, which scale linearly with the thickness of the YBCO layers over a remarkably long range of several tens of nanometres. The transfer of the electron-phonon coupling between superlattice layers can be understood as a consequence of long-range Coulomb forces in conjunction with an orbital reconstruction at the interface. The superlattice geometry thus provides new opportunities for controlled modification of the electron-phonon interaction in complex materials.

5.
BJOG ; 118(6): 719-25, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21429067

RESUMO

OBJECTIVE: To compare the effectiveness of prostaglandin E2 (dinopristone) vaginal gel versus vaginal tablets for the induction of labour at term. DESIGN: Randomised controlled clinical trial. SETTING: University maternity hospital in London. POPULATION: Pregnant women with cephalic presentation undergoing induction of labour after 37 weeks of gestation. METHODS: Prostaglandin E2 vaginal tablets (3 mg) or vaginal gel (1 mg/ 2 mg) was administered at 6-hourly intervals until the cervix was suitable for amniotomy. MAIN OUTCOME MEASURES: Induction to delivery interval, in minutes; rate of failed induction of labour requiring caesarean delivery. RESULTS: Eighty-two women received prostaglandin gel; 83 women received vaginal tablets. There were significant differences between the two treatment groups in the primary outcomes. The mean induction to delivery interval was significantly shorter in women who received the gel (1400 minutes, 690-2280 minutes, versus 1780 minutes, 960-2640 minutes; P = 0.03). The rate of failed induction of labour was significantly higher in women who received tablets (10.84 versus 1.22%; P = 0.01). Subanalysis showed that these differences were only representative of differences in the groups of primigravid women. There were no significant differences in any of the secondary outcomes, including the number of women who required syntocinon augmentation, the rate of uterine hyperstimulation, the need for epidural analgesia, meconium staining of liquor, the need for fetal blood sampling, or delivery by caesarean section. There were no differences in adverse maternal and neonatal outcomes. CONCLUSION: Prostaglandin E2 vaginal gel is superior to vaginal tablets for the induction of labour.


Assuntos
Dinoprostona , Trabalho de Parto Induzido/métodos , Ocitócicos , Administração Intravaginal , Adulto , Cesárea/estatística & dados numéricos , Feminino , Humanos , Complicações do Trabalho de Parto/etiologia , Paridade , Gravidez , Resultado da Gravidez , Comprimidos , Nascimento a Termo , Cremes, Espumas e Géis Vaginais
6.
Folia Microbiol (Praha) ; 45(3): 211-6, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11271802

RESUMO

A strain of bacteria able to detoxicate the herbicide diuron in pure culture was isolated from sites contaminated with different urea herbicides. Diuron was used as a sole source of carbon and energy by this isolate which is a Gram-negative, aerobic, rod-shaped bacterium with a single polar flagellum, and grows at 40 degrees C. The strain has been identified as Pseudomonas sp.


Assuntos
Diurona/metabolismo , Herbicidas/metabolismo , Pseudomonas/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Biodegradação Ambiental , Meios de Cultura , Pseudomonas/crescimento & desenvolvimento , Pseudomonas/isolamento & purificação
8.
Anesteziol Reanimatol ; (1): 43-8, 1996.
Artigo em Russo | MEDLINE | ID: mdl-8686942

RESUMO

Clinical and physiological effects of pressure-regulated ventilation of the lungs using the inverse rate of inhalation to exhalation (PCV-IR) were studied in two groups of patients. No appreciable advantages of this mode of pulmonary ventilation in comparison with common ("volumic") method were observed in group 1 patients (following open-heart surgery) with moderately expressed respiratory disorders (PaO2/FIO2 = 340c13 and index of lung comprometation 0.7c0.04). At the same time, the level of the peak inhalation pressure in the airways at PCV-IR was reliably lower than during common artificial ventilation of the lungs (AVL). In patients with grave respiratory disturbances (PaO2/FIO2 = 93c10 and index of lung comprometation 6.88c0.56) application of this scheme brought about an improvement of pulmonary biomechanics and gas exchange, but the hemodynamics was virtually the same. It is noteworthy that the process of PCV-IR adaptation required a thorough preliminary "adjustment" of the ventilation parameters and took rather a long time in the majority of patients. Positive effects of PCV-IR may be due to several mechanisms: a slowing down (ramp-like) flow, limitation of the upper pressure during inhalation, prolongation of exhalation in comparison with inhalation, and a regulated level of internal positive end expiratory pressure. PCV-IR is recommended as a variant of respiratory support in the treatment of patients with severe involvement of the lungs, when the potentialities of common AVL are exhausted.


Assuntos
Respiração com Pressão Positiva/métodos , Adolescente , Adulto , Análise de Variância , Procedimentos Cirúrgicos Cardíacos , Cuidados Críticos , Hemodinâmica , Humanos , Recém-Nascido , Pulmão/fisiopatologia , Pessoa de Meia-Idade , Respiração com Pressão Positiva/estatística & dados numéricos , Cuidados Pós-Operatórios , Complicações Pós-Operatórias/fisiopatologia , Complicações Pós-Operatórias/terapia , Síndrome do Desconforto Respiratório do Recém-Nascido/fisiopatologia , Síndrome do Desconforto Respiratório do Recém-Nascido/terapia , Testes de Função Respiratória/estatística & dados numéricos
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