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1.
BMC Health Serv Res ; 20(1): 344, 2020 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-32321489

RESUMO

BACKGROUND: to understand if patients seen at Centro Hospitalar Psiquiátrico de Lisboa (CHPL) live in geographical clusters or randomly throughout the city, as well as determine their access to the psychiatric hospital and primary care facilities (PCF). METHODS: spatial autocorrelation statistics were performed (queen criterion of contiguity), regarding all patients observed at CHPL in 2017 (at the census subsection level), and considering not only their overall number but also main diagnosis, and admission to the psychiatric ward - voluntary or compulsory. Distance to the hospital and to the closest PCF was measured (for each patient and the variables cited above), and the mean values were compared. Finally, the total number of patients around each PCF was counted, considering specified radius sizes of 656 and 1000 m. RESULTS: All 5161 patients (509 psychiatric admissions) were geolocated, and statistical significance regarding patient clustering was found for the total number (p-0.0001) and specific group of disorders, namely Schizophrenia and related disorders (p-0.007) and depressive disorders (p-0.0002). Patients who were admitted in a psychiatric ward live farther away from the hospital (p-0.002), with the compulsory admissions (versus voluntary ones) living even farther (p-0.004). Furthermore, defining a radius of 1000 m for each PCF allowed the identification of two PCF with more than 1000 patients, and two others with more than 800. CONCLUSIONS: as patients seem to live in geographical clusters (and considering PCFs with the highest number of them), possible locations for the development of programs regarding mental health treatment and prevention can now be identified.


Assuntos
Serviços Comunitários de Saúde Mental , Acessibilidade aos Serviços de Saúde , Atenção Primária à Saúde , Adulto , Feminino , Hospitalização/estatística & dados numéricos , Hospitais Psiquiátricos/estatística & dados numéricos , Humanos , Masculino , Transtornos Mentais/epidemiologia , Transtornos Mentais/terapia , Portugal/epidemiologia , Estudos Retrospectivos , Análise Espacial
2.
J Mater Sci Mater Med ; 31(12): 121, 2020 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-33247774

RESUMO

Avulsion of the nail plate is the most accomplished surgical procedure among the nail apparatus surgeries. Since it is not possible to use the removed nail to cover the nail bed, some materials have been suggested, however, they are generally not available for use and often at a high cost. To evaluate the use of Bacterial Cellulose (BC) dressing as a biological nail (Bio-Nail) after partial or total avulsion of the nail plate. Twenty-six candidates for nail avulsion, were randomized into two groups: Control, using Vaseline with gauze (11 patients) and Experimental group, BC group, using the Bio-Nail (15 patients). The patients were followed up during the 180-day period. The distribution of the patients in the groups was homogeneous for both sociodemographic and clinical data. The occurrence of infection (1 case in the control group) was not statistically relevant. The BC group had lower pain intensity (p = 0.011) with earlier temporal resolution when compared to the control group (p = 0.003). The BC group presented earlier reepithelization (p = 0.022) and better quantitative (p = 0.021) and qualitative conditions (p = 0.011) for the exudate. Regarding satisfaction, all the patients were satisfied. Good preservation of the nail plate area was observed in the BC group at the end of the 180-day period (p = 0.024). Average time of BC dressing permanence was 16.4 ± 7.1 days. BC showed to be appropriate as a dressing after partial or total avulsion of the nail plate. BC is a Bio-Nail promising for nail bed healing.


Assuntos
Curativos Biológicos , Celulose/química , Avulsões Cutâneas/terapia , Unhas/lesões , Unhas/cirurgia , Adolescente , Adulto , Idoso , Bactérias/química , Brasil , Celulose/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Unhas/patologia , Resultado do Tratamento , Cicatrização/fisiologia , Adulto Jovem
3.
Exp Parasitol ; 192: 46-51, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30031122

RESUMO

The cross-reaction in the diagnosis results is a serious problem, leading to an incorrect treatment and several injuries to patients. The Trypanosoma rangeli and Trypanosoma cruzi belong to the genus Trypanosoma, but the Trypanosoma rangeli is a non-pathogenic parasite to humans. While Trypanosoma cruzi is the etiological agent of Chagas' disease, which affects circa 2-3 million people and more than 6000 deaths annually in Brazil. The Leishmania chagasi causes infectious disease known as visceral leishmaniasis. This diseases have in common the crossed antigenic reaction promoted by serological tests and its differentiation is relevant for epidemiological studies and clinical practice. In this study the Fourier Transform Infrared (FT-IR) Spectroscopy was used to differentiate these microorganisms, which were cultivated and the spectra analyzed. Data analysis were performed by Gaussian curve fitting and multivariate statistical analysis. The cluster analysis have shown four specific regions to identify the microorganisms. The first three PCs of principal component analysis associated to linear discriminant were able to classify 95.6% of the parasites using cross-validation. The curve fitting method showed the quantitative differentiation among L. chagasi, T. cruzi, and T. rangeli species in the vibrational regions of polysaccharides, amide III, lipid esters, and fatty acid.


Assuntos
Leishmania infantum/isolamento & purificação , Espectroscopia de Infravermelho com Transformada de Fourier , Trypanosoma cruzi/isolamento & purificação , Trypanosoma rangeli/isolamento & purificação , Amidas/análise , Análise por Conglomerados , Reações Cruzadas , Análise Discriminante , Ésteres/análise , Ácidos Graxos/análise , Leishmania infantum/química , Leishmania infantum/classificação , Leishmania infantum/genética , Modelos Lineares , Análise Multivariada , Distribuição Normal , Polissacarídeos/análise , Análise de Componente Principal , Trypanosoma cruzi/química , Trypanosoma cruzi/classificação , Trypanosoma cruzi/genética , Trypanosoma rangeli/química , Trypanosoma rangeli/classificação , Trypanosoma rangeli/genética
4.
Andrologia ; 49(5)2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27401787

RESUMO

Male fertility can be evaluated through complete semen analysis. Plants belonging to the Tribulus genus are known for their role in enhancing sex hormone levels and semen quality. The aim of this study was to evaluate the effects of T. terrestris on semen quality and physiological parameters. Sixty-five men with abnormal semen evaluation were included in this study, in which they were prescribed with oral administration of Androsten® (250 mg of Tribulus terrestris dried extract per capsule). Body fat percentage, lean muscle mass gain, fluctuation in steroid hormone levels and all semen parameters were analysed during the period of treatment. The results demonstrated that decrease in the percentage of body fat and increase in lean mass were significant, as well as increase in dihydrotestosterone levels. Complete semen analysis evaluated at the end of treatment showed significant enhancement in sperm concentration, motility and liquefaction time. Protodioscin, the main phytochemical agent of the Tribulus genus, acts on sertoli cells, germ cell proliferation and growth of seminiferous tubules. This component is known to convert testosterone into dihydrotestosterone, which plays important roles in male attributes. Our results indicate the therapeutic use of Tribulus terrestris by men presenting altered semen parameters, and/or undergoing infertility treatment.


Assuntos
Composição Corporal/efeitos dos fármacos , Infertilidade Masculina/tratamento farmacológico , Extratos Vegetais/administração & dosagem , Sêmen/efeitos dos fármacos , Sêmen/fisiologia , Tribulus/química , Adulto , Di-Hidrotestosterona/sangue , Humanos , Infertilidade Masculina/fisiopatologia , Masculino , Pessoa de Meia-Idade , Análise do Sêmen , Contagem de Espermatozoides , Motilidade dos Espermatozoides , Espermatozoides/efeitos dos fármacos , Espermatozoides/fisiologia
5.
Nano Lett ; 15(4): 2517-25, 2015 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-25723908

RESUMO

Stable and high-performance nanoporous "black silicon" photoelectrodes with electrolessly deposited Pt nanoparticle (NP) catalysts are made with two metal-assisted etching steps. Doubly etched samples exhibit an ∼300 mV positive shift in photocurrent onset for photoelectrochemical proton reduction compared to oxide-free planar Si with identical catalysts. We find that the photocurrent onset voltage of black Si photocathodes prepared from single-crystal planar Si wafers by an Ag-assisted etching process increases in oxidative environments (e.g., aqueous electrolyte) owing to a positive flat-band potential shift caused by surface oxidation. However, within 24 h, the surface oxide layer becomes a kinetic barrier to interfacial charge transfer that inhibits proton reduction. To mitigate this issue, we developed a novel second Pt-assisted etch process that buries the Pt NPs deep into the nanoporous Si surface. This second etch shifts the onset voltage positively, from +0.25 V to +0.4 V versus reversible hydrogen electrode, and reduces the charge-transfer resistance with no performance decrease seen for at least two months. PEC performance was stable owing to Pt NP catalysts that were buried deeply in the photoelectrode by the second etch, below a thick surface layer comprised primarily of amorphous SiO2 along with some degree of remaining crystalline Si as observed by scanning and transmission electron micrographs. Electrochemical impedance studies reveal that the second etch leads to a considerably smaller interfacial charge-transfer resistance than samples without the additional etch, suggesting that burying the Pt NPs improves the interfacial contact to the crystalline silicon surface.

6.
J Mater Sci Mater Med ; 25(1): 229-37, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24072391

RESUMO

It is of current interest the identification of appropriate matrices for growing mesenchymal stem cells (MSC). These cells are able not only to regenerate themselves but also to differentiate into other type of functional cells, and so they have been extensively used in tissue engineering. In this work, we have evaluated the use of electric impedance spectroscopy (EIS) to follow the adhesion of MSC from Wharton's jelly of the human umbilical cord (hWJMSC) on sugarcane biopolymers (SCB). Impedance spectra of the systems were obtained in the frequency range of 10(2)-10(5) Hz. An EIS investigation showed that when deposited on a metallic electrode SCB films prevent the passage of electrons between the solution and the metallic interface. The impedance spectra of hWJMSCs adhered on SCB revealed that there is a significant increase in the magnitude of the impedance when compared to that of pure SCB. The corresponding resistance (real part of the impedance) was even higher for the SCB-hWJMSC system than for SCB without cells on their surface, in an indication of an increased blockage to the electron transfers. The resistance charge transfer is extracted by curve-fitting the impedance spectra to an equivalent circuit model. Also, a shift of the phase angle to higher frequencies was obtained for SCB-hWJMSC system as a result from hWJMSC adhesion. Our study demonstrates that EIS is an appropriate method to evaluate the adhesion of MSC. SCB can be considered as a promising biomaterial for tissue engineering.


Assuntos
Materiais Biocompatíveis/química , Biopolímeros/química , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/fisiologia , Saccharum/química , Cordão Umbilical/citologia , Adesão Celular , Células Cultivadas , Impedância Elétrica , Feminino , Humanos , Teste de Materiais , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Gravidez , Engenharia Tecidual , Geleia de Wharton/citologia
7.
J Phys Chem Lett ; 15(9): 2573-2579, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38417042

RESUMO

Surface superconductivity, wherein electron pairing occurs at material surfaces or interfaces, has attracted a remarkable amount of attention since its discovery. Recent theoretical predictions have unveiled increased critical temperatures, especially at the surfaces of certain compounds and/or structures. The notion of "surface ordering" has been advanced to elucidate this phenomenon. Employing the framework of self-consistent Bogoliubov-de Gennes equations and a model incorporating correlated disorder, our study demonstrates the persistence of the surface ordering effect in the presence of weak to moderate bulk disorder. Intriguingly, our findings indicate that under moderate disorder conditions the surface critical temperature can be further increased, depending on the intensity and correlation of the disorder.

8.
J Phys Condens Matter ; 36(25)2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38498947

RESUMO

To describe the way complexity emerges in seemingly simple systems of nature, requires one to attend to two principal questions: how complex patterns appear spontaneously and why a single system can accommodate their inexhaustible variety. It is commonly assumed the pattern formation phenomenon is related to the competition of several types of interactions with disparate length scales. These multi-scale interactions also lead to frustration within the system, resulting in the existence of a manifold of configurations-patterns with qualitatively distinct morphologies. This work explores an alternative approach through a mechanism that leads to a wide range of intricate and topologically non-trivial patterns. The mechanism is described by the self-dual Ginzburg-Landau theory and, possibly, other Maxwell-Higgs models. It gives rise to unique spatial flux and condensate spatial profiles observed in superconductors between the two conventional superconductivity types I and II.

9.
Phys Rev Lett ; 111(8): 087202, 2013 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-24010469

RESUMO

We observe interfacial ferromagnetism in superlattices of the paramagnetic metal LaNiO3 and the antiferromagnetic insulator CaMnO3. LaNiO3 exhibits a thickness dependent metal-insulator transition and we find the emergence of ferromagnetism to be coincident with the conducting state of LaNiO3. That is, only superlattices in which the LaNiO3 layers are metallic exhibit ferromagnetism. Using several magnetic probes, we have determined that the ferromagnetism arises in a single unit cell of CaMnO3 at the interface. Together these results suggest that ferromagnetism can be attributed to a double exchange interaction among Mn ions mediated by the adjacent itinerant metal.

10.
J Periodontal Res ; 48(2): 151-8, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22891744

RESUMO

BACKGROUND AND OBJECTIVE: Stress and anxiety have been associated with chronic periodontitis, but few studies examining the effects of psychotropic drugs on periodontal health have been performed. Therefore, we aimed to investigate the effects of diazepam on the progression of periodontitis in chronically stressed rats. MATERIAL AND METHODS: Fourteen Wistar rats were submitted to ligature-induced periodontal disease and were divided into four groups . Two groups were not stressed, whereas two groups were submitted to a conditioned fear stress paradigm for 38 d. Daily diazepam treatment (2 mg/kg, orally) was administered to one unstressed group and to one group submitted to a conditioned fear stress paradigm from day 2 to the day 39, at which point the rats were submitted to an open field test and were killed on day 40. Brains and mandibles were removed for histological and immunohistochemical analyses. RESULTS: Animals exposed to conditioned fear stress presented an increase in freezing behavior, a decrease in locomotor activity, enhanced alveolar bone loss and higher levels of hippocampal interleukin-1beta (IL-1ß) and interleukin-6 (IL-6), compared with the control group. Diazepam, at the dose used in the current study, had no effect on freezing behavior but reversed the decrease in locomotor activity provoked by stress. Additionally, the treatment reduced the levels of hippocampal IL-1ß and IL-6 and alveolar bone loss in Wistar rats. Neither conditioned fear stress nor diazepam treatment had an effect on periodontal IL-1ß or IL-6 levels in animals. CONCLUSION: Our results suggest that diazepam treatment reduces bone loss in rats submitted to conditioned fear stress. In addition, diazepam treatment led to decreased IL-1ß and IL-6 levels in the hippocampus.


Assuntos
Perda do Osso Alveolar/prevenção & controle , Ansiolíticos/uso terapêutico , Diazepam/uso terapêutico , Medo/fisiologia , Hipocampo/metabolismo , Interleucina-1beta/análise , Interleucina-6/análise , Perda do Osso Alveolar/metabolismo , Animais , Ansiolíticos/administração & dosagem , Condicionamento Operante , Diazepam/administração & dosagem , Progressão da Doença , Medo/psicologia , Reação de Congelamento Cataléptica/fisiologia , Hipocampo/patologia , Locomoção/fisiologia , Masculino , Ligamento Periodontal/metabolismo , Ligamento Periodontal/patologia , Periodontite/prevenção & controle , Periodontite/psicologia , Ratos , Ratos Wistar , Estresse Psicológico/metabolismo , Estresse Psicológico/psicologia
11.
J Periodontal Res ; 48(5): 632-7, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23425324

RESUMO

BACKGROUND AND OBJECTIVE: Recent evidence suggests that the use of fluoxetine could reduce periodontal disease severity. However, the effect of fluoxetine on periodontal disease has not been tested in the context of conditioned fear stress (CFS). We hypothesized that inhibition of chronic stress by fluoxetine might decrease the levels of bone loss in periodontal disease. The aim of the present study was to analyze the effect of fluoxetine on bone loss in chronic periodontitis. MATERIAL AND METHODS: Fourteen Wistar rats were submitted to ligature-induced periodontal disease and divided into four groups (A-D). Groups A (n = 3) and B (n = 4) were not stressed, while Groups C (n = 3) and D (n = 4) were submitted to a CFS paradigm for 38 d. Daily fluoxetine (20 mg/kg) was administered to Groups B and D from day 20 to day 39, at which point the rats were submitted to an open field test and killed on day 40. Mandibles were removed for histological and immunohistochemical analyses. RESULTS: Stress was associated with a higher level of bone loss in Group C compared with Group A. Additionally, no differences in bone loss were observed among Groups A, B and D. CONCLUSION: We showed that stress is associated with the progression of bone loss in a CFS model in rats and that fluoxetine treatment reduces the bone loss.


Assuntos
Periodontite Crônica/prevenção & controle , Medo/psicologia , Fluoxetina/uso terapêutico , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Estresse Psicológico/psicologia , Perda do Osso Alveolar/patologia , Perda do Osso Alveolar/prevenção & controle , Perda do Osso Alveolar/psicologia , Animais , Ansiedade/psicologia , Periodontite Crônica/patologia , Periodontite Crônica/psicologia , Condicionamento Psicológico , Modelos Animais de Doenças , Progressão da Doença , Reação de Congelamento Cataléptica/fisiologia , Interleucina-1beta/análise , Interleucina-6/análise , Locomoção/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar
12.
J Phys Chem Lett ; 14(24): 5657-5664, 2023 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-37311195

RESUMO

Using the tight-binding Bogoliubov-de Gennes formalism, we describe the influence of the surface potential on the superconducting critical temperature at the surface. Surface details are taken into account within the framework of the self-consistent Lang-Kohn effective potential. The regimes of strong and weak coupling of superconducting correlations are considered. Our study reveals that, although the enhancement of the surface critical temperature, originating from the enhancement of the localized correlation due to the constructive interference between quasiparticle bulk orbits, can be sufficiently affected by the surface potential, this influence, nonetheless, strongly depends on the bulk material parameters, such as the effective electron density parameter and Fermi energy, and is likely to be negligible for some materials, in particular for narrow-band metals. Thus, superconducting properties of a surface can be controlled by the surface/interface potential properties, which offer an additional tuning knob for the superconducting state at the surface/interface.

13.
Mol Biol Rep ; 39(4): 4455-9, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21947840

RESUMO

Allele frequencies for the high polymorphic short tandem repeats (STR) loci PentaE, PentaD, D18S51, D21S11, TH01, D3S1358, FGA, D16S539, D7820, D13S317, vWA and D81179 were analysed in an native Amerindian population from Mato Grosso do Sul state named Terena. Deviations from Hardy-Weinberg expectations were evaluated and the results showed no differences from equilibrium in all loci. The combined power of discrimination and the combined power of exclusion for the 12 tested STR loci were 0.99999999 and 0.999999 respectively. The Terena population data were compared to other from 11 Brazilian populations (Amazônia, Pernambuco, Mato Grosso do Sul, São Paulo, Rio Grande do Sul, Alagoas, Sergipe, Rio Grande do Norte, Santa Catarina, Rondônia and Rio de Janeiro) representing the major Brazilian geographic regions. The F(ST) comparative analysis showed no significant differences between all those populations except when comparing Terena with the remained ones.


Assuntos
Cromossomos Humanos/genética , Etnicidade/genética , Genética Populacional , Indígenas Sul-Americanos/genética , Repetições de Microssatélites/genética , Brasil , Genética Forense , Frequência do Gene/genética , Geografia , Humanos
14.
Artigo em Inglês | MEDLINE | ID: mdl-22675382

RESUMO

Libidibia ferrea has been used in folk medicine throughout Brazil, and this study evaluated the biological activities of crude extract (CE) as well as a partially purified fraction (F80) obtained from its pods. Results from the MTT assay revealed that only F80 inhibited NCI-H292 cell growth; however, neither CE nor F80 reduced HEp-2 cell growth or sarcoma 180 tumor weight with the in vivo assay. Acute oral toxicity of the extract and fraction was evaluated following the steps of Guideline 423, using female mice; LD(50) for both preparations was determined as 2,500 mg/kg body weight. CE and F80 promoted a reduction of the leukocyte number and nitrite level in inflammatory exudates when the anti-inflammatory assay (carrageenan-induced peritonitis) was performed. CE and F80 inhibited writhing regarding antinociceptive activity (acetic acid-induced writhing response in mice). In conclusion, CE and F80 have no significant cytotoxic or antitumor activities in cell lines showing low toxicity and no action against tumors in vivo. Both preparations revealed anti-inflammatory and antinociceptive activities, corroborating the pharmacological basis of L. ferrea for ethnomedical use.

15.
J Phys Chem Lett ; 12(17): 4172-4179, 2021 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-33896186

RESUMO

Cluster formation is a focus of interdisciplinary research in both chemistry and physics. Here we discuss the exotic example of this phenomenon in the vortex matter of a thin superconductor. In superconducting films, the clustering takes place because of particular properties of the vortex interactions in the crossover or intertype regime between superconductivity types I and II. These interactions are controlled by the two parameters that are responsible for the crossover, Ginzburg-Landau parameter κ, which specifies the superconducting material of the film, and film thickness d, which controls effects due to stray magnetic fields outside the sample. We demonstrate that their competition gives rise to a complex spatial dependence of the interaction potential between vortices, favoring the formation of chainlike vortex clusters.

16.
J Phys Condens Matter ; 33(10): 105902, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33285526

RESUMO

We demonstrate that the presence of edges in a superconducting film made of a type-I/type-II bilayer stabilizes type-II/type-I hybrid (inter-type) flux patterns, as vortex clusters, chains, and gel phase. These patterns are very sensitive to primary parameters such as applied magnetic field, layer coupling, and temperature. Thus, the magnetization versus temperature curves, M(T), for many values of coupling were used to estimate the strength of the layer couplings, and also as a guide for obtaining sequentially the flux patterns. We also show that the effect of the borders on the unrestricted states is to shift them to states of higher density, since they introduce extra compression on the vortex matter. For a low layer coupling regime, we observe an unusual magnetic response where few partial vortices (partial in a sense they miss the contribution of the type I part), repelling each other and bounded to the surfaces, populate one layer leaving the other empty. We expect that the predicted flux configurations can stimulate experimentalists in trying to observe them by direct imaging techniques.

17.
J Phys Condens Matter ; 32(45): 455702, 2020 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-32688355

RESUMO

There is a tacit assumption that multiband superconductors are essentially the same as multigap superconductors. More precisely, it is usually assumed that the number of excitation gaps in the single-particle energy spectrum of a uniform superconductor (i.e. number of peaks in the density of states of the superconducting electrons) determines the number of contributing bands in the corresponding superconducting model. Here we demonstrate that contrary to this widely accepted viewpoint, the superconducting magnetic properties are sensitive to the number of contributing bands even when the spectral gaps are degenerate and cannot be distinguished. In particular, we find that the crossover between superconductivity types I and II-the intertype regime-is strongly affected by the difference between characteristic lengths of multiple contributing condensates. The reason for this is that condensates with diverse characteristic lengths, when coexisting in one system, interfere constructively or destructively, which results in multi-condensate magnetic phenomena regardless of the presence/absence of the multigap spectrum of a superconducting multiband material.

18.
J Phys Condens Matter ; 32(7): 075403, 2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-31675734

RESUMO

Superconducting films are usually regarded as type II superconductors even when they are made of a type I material. The reason is the presence of stray magnetic fields that stabilize the vortex matter by inducing long-range repulsive interactions between vortices. While very thin films indeed reach this limit, there is a large interval of thicknesses where magnetic properties of superconducting films cannot be classified as either of the two conventional superconductivity types. Recent calculations revealed that in this interval the system exhibits spontaneous formation of magnetic flux-condensate patterns and superstructures appearing due to the interplay between the long-range stray field effects and proximity to the Bogomolnyi self-duality point. These calculations were based on the periodic in-plane boundary conditions which, as is well known from classical electrodynamics, for systems with long-range interactions can lead to field distortions and considerable discrepancies between results of different calculation methods. Here we demonstrate that similar spontaneous patterns are obtained for superconducting films with open in-plane boundary conditions (vanishing in-plane currents perpendicular to the edges of the finite film) and thus the phenomenon is not an artefact of chosen boundary conditions.

19.
Waste Manag ; 94: 39-48, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31279394

RESUMO

The construction sector has been using supplementary materials in concrete production worldwide, such as coal fly ash. Nowadays, several sub/products or wastes have been studied to be incorporated in construction materials, and one of those wastes is biomass fly ash. However, using high volumes of these materials has some drawbacks, one of them being carbonation. In order to understand phenomena such as this, it is important to study the interaction between the additions and hydration of cement. This paper focuses on the study of hydration and carbonation of cementitious pastes containing biomass fly ash and/or coal fly ash by using thermogravimetric analysis and X-ray diffraction analysis and by accelerated carbonation tests. BFA present different chemical and mineralogical composition than CFA. The results show that incorporating biomass fly ash into construction materials has a similar carbonation behaviour to coal fly ash. Biomass fly ash seems to give some extra alkalinity to the mixtures, and this may present benefits to the construction materials and for the ash management.


Assuntos
Cinza de Carvão , Carvão Mineral , Biomassa , Carbono , Materiais de Construção , Reciclagem
20.
Sci Adv ; 5(10): eaaw1949, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31976364

RESUMO

While machine learning has been making enormous strides in many technical areas, it is still massively underused in transmission electron microscopy. To address this, a convolutional neural network model was developed for reliable classification of crystal structures from small numbers of electron images and diffraction patterns with no preferred orientation. Diffraction data containing 571,340 individual crystals divided among seven families, 32 genera, and 230 space groups were used to train the network. Despite the highly imbalanced dataset, the network narrows down the space groups to the top two with over 70% confidence in the worst case and up to 95% in the common cases. As examples, we benchmarked against alloys to two-dimensional materials to cross-validate our deep-learning model against high-resolution transmission electron images and diffraction patterns. We present this result both as a research tool and deep-learning application for diffraction analysis.

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