Localized surface plasmon effects on the photophysics of perovskite thin films embedding metal nanoparticles

Herein we provide direct experimental evidence that proves that the photophysical properties of thin methylammonium lead iodide perovskite films are significantly enhanced by localized surface plasmon resonances (SPRs). Observations are well supported by rigorous calculations that prove that improved light harvesting can be unequivocally attributed to plasmonic scattering and near field reinforcement effects around silver nanoparticles embedded within the semiconductor layer. Adequate design of the localized SPR allows raising the absorptance of a 300 nm thick film at well-defined spectral regions while minimizing the parasitic absorption from the metallic inclusions. Measured enhancements can be as large as 80% at specific wavelengths and 20% when integrated over the whole range at which SPR occurs, in agreement with theoretical estimations. Simultaneously, the characteristic quenching effect that the vicinity of metals has on the photoluminescence of semiconductors is largely compensated for by the combined effect of the enhanced photoexcitation and the higher local density of photon states occurring at SPR frequencies, with a two fold increase of the perovskite photoemission efficiency being measuredThe research leading to these results has received funding from the Spanish Ministry of Economy and Competitiveness under grant MAT2017-88584-R (AEI/FEDER,UE). A. B. was supported by the U. S. Department of State through the Fulbright Program. S. C. P. is grateful for the support of the AEI under the Juan de la Cierva Incorporación programme (IJCI-2016-28549

Prosthetic bypass for restenosis after endarterectomy or stenting of the carotid artery

OBJECTIVE: The objective of this study was to evaluate the results of prosthetic carotid bypass (PCB) with polytetrafluoroethylene (PTFE) grafts as an alternative to carotid endarterectomy (CEA) in treatment of restenosis after CEA or carotid artery stenting (CAS). METHODS: From January 2000 to December 2014, 66 patients (57 men and 9 women; mean age, 71 years) presenting with recurrent carotid artery stenosis ≥70% (North American Symptomatic Carotid Endarterectomy Trial [NASCET] criteria) were enrolled in a prospective study in three centers. The study was approved by an Institutional Review Board. Informed consent was obtained from all patients. During the same period, a total of 4321 CEAs were completed in the three centers. In these 66 patients, the primary treatment of the initial carotid artery stenosis was CEA in 57 patients (86%) and CAS in nine patients (14%). The median delay between primary and redo revascularization was 32 months. Carotid restenosis was symptomatic in 38 patients (58%) with transient ischemic attack (n = 20) or stroke (n = 18). In this series, all patients received statins; 28 patients (42%) received dual antiplatelet therapy, and 38 patients (58%) received single antiplatelet therapy. All PCBs were performed under general anesthesia. No shunt was used in this series. Nasal intubation to improve distal control of the internal carotid artery was performed in 33 patients (50%), including those with intrastent restenosis. A PTFE graft of 6 or 7 mm in diameter was used in 6 and 60 patients, respectively. Distal anastomosis was end to end in 22 patients and end to side with a clip distal to the atherosclerotic lesions in 44 patients. Completion angiography was performed in all cases. The patients were discharged under statin and antiplatelet treatment. After discharge, all of the patients underwent clinical and Doppler ultrasound follow-up every 6 months. Median length of follow-up was 5 years. RESULTS:No patient died, sustained a stroke, or presented with a cervical hematoma during the postoperative period. One transient facial nerve palsy and two transient recurrent nerve palsies occurred. Two late strokes in relation to two PCB occlusions occurred at 2 years and 4 years; no other graft stenosis or infection was observed. At 5 years, overall actuarial survival was 81% ± 7%, and the actuarial stroke-free rate was 93% ± 2%. There were no fatal strokes. CONCLUSIONS: PCB with PTFE grafts is a safe and durable alternative to CEA in patients with carotid restenosis after CEA or CAS in situations in which CEA is deemed either hazardous or inadvisable

Pilares mistos parcialmente revestidos: resistência e rigidez em situação de incêndio

Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do ParanáOs pilares mistos parcialmente revestidos de aço e concreto possuem uma grande resistência quando comparados com os pilares puros de aço. Contudo não é possivel calcular a resistencia de todos os membros de sua composição tendo em consideração somente a temperatura do aço. A resistência destes elementos quando submetidos a situações de incêndio depende da evolução da temperatura durante o período exposto ao fogo. O anexo G do Eurocódigo EN 1994-1-2 [1], através do método da soma pesada das quatro componentes, permite calcular a carga resistente à encurvadura de pilares mistos parcialmente revestidos em situação de incêndio, para diferentes tempos de resistência quando submetidos ao fogo padrão. Uma nova proposta foi apresentada para melhorar os resultados deste método [2], procurando utilizar novas fórmulas para o cálculo da carga plástica de compressão e rigidez de flexão de cada componente da seção transversal. Este trabalho visa avaliar e investigar as novas fórmulas propostas, e quando necessário propor um aperfeiçoamento das mesmas. As novas formulações propostas para determinar a carga resistente à encurvadura permitem avaliar de forma mais precisa a temperatura, e consequentemente a resistência das componentes da seção transversal, sendo estes a temperatura média dos banzos e do aço do reforço, a temperatura média e a altura residual da alma baseada na isotérmica de 400ºC e a temperatura média e a área residual do concreto baseado na isotérmica de 500ºC. O método de cálculo avançado, será realizado através de um programa de elementos finitos ANSYS ®, tendo seus resultados utilizados para investigar estas novas formulações, com base na análise da seção transversal totalmente envolvida pelo fogo. O método simplificado de cálculo é baseado no efeito da temperatura nas quatro componentes do perfil (banzos, alma, aço do reforço e concreto) para tempos específicos de resistência ao fogo: R30, R60, R90 e R120 minutos. Os resultados obtidos pelas simulações numéricas serão utilizados para comparar com as formulações proposta pelo método simplificado de cálculo - nova proposta [2], assim como as formulações dispostas no anexo G do Eurocódigo EN 1994-1-2 [1].Partially encased columns of steel and concrete have a high resistance when compared to steel columns. However it is not possible to measure the resistance of all members of its composition taking into account only the temperature of the steel. The resistance of these elements under fire conditions depends on the temperature evolution during the period exposed to fire. The annex G of Eurocode EN 1994-1-2 [1], through the balanced summation method allows to calculate the buckling resistance of partially encased columns when submitted to standard fire for different rating time of exposure. A new proposal was presented to be used with this methodology [2]. New formulas were presented to calculate the plastic resistance to axial compression and the flexural stiffness of each component of the cross section. This work aims to evaluate and investigate the new proposal, and when necessary improve it. The new formulae was developed to determine the buckling resistance load, taking into consideration the average temperature of all components of the cross section, the residual height of the web based on 400ºC isothermal and the residual concrete area based on the 500ºC isothermal. The advanced calculation method will be carried out using the finite element program ANSYS ®, being the results used to investigate these new formulations, taking into consideration a cross section totally surrounded by fire. The simplified method is based on the temperature effect on four components (flanges, web, reinforcement and concrete) for specific fire resistance: R30, R60, R90, R120 minutes. The results obtained by the numerical simulations will be used to compare with the formulae from new proposal [2] as well as the formulae from EN 1994-1-2 annex G [2]

Phylogeny of helieae (gentianaceae): resolving taxonomic chaos in a neotropical clade

The monophyletic and Neotropical tribe Helieae of the worldwide family Gentianaceae (Gentianales, Asterids, Angiospermae) is well known for its problematic generic classifications. An initial phylogenetic analysis of Helieae shed light onto the relationships between genera, and indicated that traditional generic limits did not correspond to monophyletic groups. In order to obtain a more thorough understanding of generic relationships within the group, we enhanced sampling within the so-called Symbolanthus clade and performed phylogenetic analyses from DNA sequences from one plastid region (matK) and two nuclear regions (ITS and 5S-NTS), plus 112 morphological characters, which were analyzed separately and in combination, using parsimony and Bayesian approaches. A total of 83 individuals representing 20 genera and 51 species of Helieae were sampled; 13 species were included in this study solely based on their morphological characters. Ancestral character reconstructions were performed to identify potential synapomorphies of clades and patterns of homoplasy in the morphological dataset. Our results demonstrate that Prepusa is sister to the remainder of Helieae. Furthermore, the Macrocarpaea clade, the Irlbachia clade and the Symbolanthus clade were also recovered. Within the Symbolanthus clade, our results confirm that Calolisianthus and Chelonanthus are not monophyletic, and also contest the monophyly of Irlbachia as currently circumscribed. Specifically, two species of Calolisianthus group with the type species of Chelonanthus, while the other Calolisianthus species are more closely related to Tetrapollinia and Symbolanthus. Moreover, the green-white-flowered Chelonanthus species and Adenolisianthus are undoubtedly related to Helia and several analyses support Irlbachia pratensis as more closely related to the lineage including the type species of Chelonanthus described above The addition of new characters and taxa led to higher confidence in the relative position of some clades, as well as provided further support for a new generic circumscription of Calolisianthus, Chelonanthus, and Helia. Even though several morphological characters traditionally used in the taxonomy of the group were shown to be homoplasious, most clades can be diagnosed by a combination of morphological character states10619220

Theoretical and numerical results about some weakly singular Volterra-Fredholm equations

In this paper existence, uniqueness results for the solution of some weakly singular linear Volterra and Volterra-Fredholm integral equations are given. For these equations, a numerical model is proposed and its convergence and rate of convergence are analyzed. Numerical results on some polynomial test functions are given

Spatio-temporal evolution of the catuaba clade in the Neotropics: morphological shifts correlate with habitat transitions

Aim: The biotic assembly of one of the most species-rich savannas, the Brazilian Cerrado, has involved recruitment of lineages from several surrounding regions. However, we lack a clear understanding about the timing and pathways of biotic exchanges among these regions and about the role those interchanges had in the assembly of Neotropical biodiversity. We investigated the timing and routes of species movements between wet or seasonally dry habitats across Neotropical regions and assessed the potential for ecological adaptation by evaluating the habitat transitions correlated with morphological shifts. Location: Neotropics. Taxon: The plant genus Anemopaegma (Bignonieae, Bignoniaceae). Methods: We inferred a Bayesian molecular phylogeny of Anemopaegma using one nuclear and two chloroplast markers. We sampled more than 90% of the known species diversity of Anemopaegma, covering its full geographical range. We estimated divergence times using a Bayesian relaxed-clock approach and inferred ancestral ranges as well as shifts in habitat and morphological characters. Results: Phylogenetic analyses recovered seven main clades within Anemopaegma. The genus likely originated in Amazonia in the late Oligocene. Early-diverging lineages diversified in situ in Amazonia, particularly during the Miocene, with independent dispersal events to the Andes, Atlantic Forest and Cerrado. Shifts from seasonally dry forest to savanna habitats were correlated with shifts from liana to shrub and the loss of tendrils. Main Conclusions: The timing of diversification of major lineages within Anemopaegma is consistent with major geological and climatic events that occurred during the late Palaeogene and Neogene, such as the Andean uplift and the Middle Miocene Climatic Optimum. Movements across different regions within the Neotropics were relatively common but shifts between habitats were not. The correlation in the evolution of the shrubby habit, the loss of tendrils and the shifts from forest to savanna are consistent with a scenario of ecological adaptation

Transplantation of bone marrow mesenchymal stem cells decreases oxidative stress, apoptosis, and hippocampal damage in brain of a spontaneous stroke model

Stroke is the most common cause of motor disabilities and is a major cause of mortality worldwide. Adult stem cells have been shown to be effective against neuronal degeneration through mechanisms that include both the recovery of neurotransmitter activity and a decrease in apoptosis and oxidative stress. We chose the lineage stroke-prone spontaneously hypertensive rat (SHRSP) as a model for stem cell therapy. SHRSP rats can develop such severe hypertension that they generally suffer a stroke at approximately 1 year of age. the aim of this study was to evaluate whether mesenchymal stem cells (MSCs) decrease apoptotic death and oxidative stress in existing SHRSP brain tissue. the results of qRT-PCR assays showed higher levels of the antiapoptotic BcI-2 gene in the MSC-treated animals, compared with untreated. Our study also showed that superoxide, apoptotic cells, and by-products of lipid peroxidation decreased in MSC-treated SHRSP to levels similar those found in the animal controls, Wistar Kyoto rats. in addition, we saw a repair of morphological damage at the hippocampal region after MSC transplantation. These data suggest that MSCs have neuroprotective and antioxidant potential in stroke-prone spontaneously hypertensive rats. (c) 2014 the Authors. Published by Elsevier Inc.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, Dept Biofis, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Ctr Desenvolvimento Modelos Expt Med & Biol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Morfol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Fisiol, BR-04023062 São Paulo, BrazilUniv Santa Cecilia, Dept Odontol, Santos, SP, BrazilUniversidade Federal de São Paulo, Dept Nefrol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biofis, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Ctr Desenvolvimento Modelos Expt Med & Biol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Morfol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Fisiol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Nefrol, BR-04023062 São Paulo, BrazilFAPESP: 05/60630-1FAPESP: 10/00106-5Web of Scienc

Flora da Serra do Cipó, Minas Gerais: Rubiaceae

O estudo da família Rubiaceae é parte do levantamento da "Flora da Serra do Cipó, Minas Gerais, Brasil". Esta família é representada na área por 36 gêneros, totalizando 91 espécies. Uma nova espécie de Psyllocarpus é descrita e ilustrada. São apresentadas chave para gêneros e espécies, descrições e ilustrações, além de comentários sobre a distribuição geográfica e hábitat das espécies