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Salmonella enterica is a major food-borne pathogen that affects cattle-rearing systems worldwide. Little information is available on the epidemiology and pathology of salmonellosis and the virulence genes (VGs) carried by Salmonella in spontaneous outbreaks in cattle. We describe epidemiological findings in 15 fatal outbreaks of salmonellosis in Uruguayan dairy farms and the age, clinical signs, and pathology in 20 affected calves. We also describe the serotypes and frequencies of 17 VGs in the causative Salmonella strains and explore their associations with epidemiological, clinical, and pathological findings. Salmonella Typhimurium and Dublin were identified in 11/15 and 4/15 outbreaks, respectively. The most frequent reason for consultation was digestive disease (8 outbreaks caused by S. Typhimurium), followed by sudden death (4 outbreaks, 3 caused by S. Dublin). Morbidity, mortality, and lethality ranged 4.8-100%, 3.8-78.9%, and 10-100%, without significant differences between serotypes. Diarrhea, the most common clinical sign (14 cases), was associated with the Typhimurium serotype (OR = 26.95), especially in ≤ 30-day-old calves with fibrinous enteritis as the main autopsy finding. The Dublin serotype affected ≥ 50-day-old calves and was associated with fibrinosuppurative splenitis (p = 0.01) and tubulointerstitial nephritis (OR = 48.95). The chances of the Dublin serotype increased significantly with age. There was low variability of VG across serotypes. The pefA gene was associated with the Typhimurium serotype (OR = 21.95), macroscopic enteritis (p = 0.03), and microscopic fibrinosuppurative splenitis (p = 0.04). Understanding the epidemiology, pathology, and virulence of S. enterica at the farm level is key to delineating prevention and control strategies to mitigate its impact on animal and human health.
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Doenças dos Bovinos , Intoxicação Alimentar por Salmonella , Salmonelose Animal , Salmonella enterica , Humanos , Animais , Bovinos , Salmonella typhimurium , Virulência , Salmonelose Animal/microbiologia , Doenças dos Bovinos/microbiologia , Surtos de DoençasRESUMO
Weak multiplex percolation generalizes percolation to multi-layer networks, represented as networks with a common set of nodes linked by multiple types (colors) of edges. We report a novel discontinuous phase transition in this problem. This anomalous transition occurs in networks of three or more layers without unconnected nodes, [Formula: see text]. Above a critical value of a control parameter, the removal of a tiny fraction [Formula: see text] of nodes or edges triggers a failure cascade which ends either with the total collapse of the network, or a return to stability with the system essentially intact. The discontinuity is not accompanied by any singularity of the giant component, in contrast to the discontinuous hybrid transition which usually appears in such problems. The control parameter is the fraction of nodes in each layer with a single connection, [Formula: see text]. We obtain asymptotic expressions for the collapse time and relaxation time, above and below the critical point [Formula: see text], respectively. In the limit [Formula: see text] the total collapse for [Formula: see text] takes a time [Formula: see text], while there is an exponential relaxation below [Formula: see text] with a relaxation time [Formula: see text].
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Oral tolerance blocks the development of specific immune responses to proteins ingested by the oral route. One of the first registries of oral tolerance showed that guinea pigs fed corn became refractory to hypersensitivity to corn proteins. Mice fed with chow containing corn are tolerant to zein, and parenteral injection of zein plus adjuvant blocks immunization to unrelated proteins injected concomitantly and reduces unspecific inflammation. Extensive and prolonged inflammatory infiltrate in the wound bed is one of the causes of pathological wound healing. Previous research shows that intraperitoneal injection of zein concomitant with skin injuries reduces the inflammatory infiltrate in the wound bed and improves wound healing. Herein, we tested if one subcutaneous injection of zein before skin injury improves wound healing. We also investigated how long the effects triggered by zein could improve skin wound healing. Mice fed zein received two excisional wounds on the interscapular skin under anesthesia. Zein plus Al(OH)3 was injected at the tail base at 10 min, or 3, 5, or 7 days before skin injuries. Wound healing was analyzed at days 7 and 40 after injury. Our results showed that a zein injection up to 5 days before skin injury reduced the inflammatory infiltrate, increased the number of T-cells in the wound bed, and improved the pattern of collagen deposition in the neodermis. These findings could promote the development of new strategies for the treatment and prevention of pathological healing using proteins normally found in the common diet.
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Pele , Cicatrização , Animais , Colágeno , Cobaias , Injeções Intraperitoneais , Injeções Subcutâneas , CamundongosRESUMO
Oral tolerance blocks the development of specific immune responses to proteins ingested by the oral route. One of the first registries of oral tolerance showed that guinea pigs fed corn became refractory to hypersensitivity to corn proteins. Mice fed with chow containing corn are tolerant to zein, and parenteral injection of zein plus adjuvant blocks immunization to unrelated proteins injected concomitantly and reduces unspecific inflammation. Extensive and prolonged inflammatory infiltrate in the wound bed is one of the causes of pathological wound healing. Previous research shows that intraperitoneal injection of zein concomitant with skin injuries reduces the inflammatory infiltrate in the wound bed and improves wound healing. Herein, we tested if one subcutaneous injection of zein before skin injury improves wound healing. We also investigated how long the effects triggered by zein could improve skin wound healing. Mice fed zein received two excisional wounds on the interscapular skin under anesthesia. Zein plus Al(OH)3 was injected at the tail base at 10 min, or 3, 5, or 7 days before skin injuries. Wound healing was analyzed at days 7 and 40 after injury. Our results showed that a zein injection up to 5 days before skin injury reduced the inflammatory infiltrate, increased the number of T-cells in the wound bed, and improved the pattern of collagen deposition in the neodermis. These findings could promote the development of new strategies for the treatment and prevention of pathological healing using proteins normally found in the common diet.
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Message-passing theories have proved to be invaluable tools in studying percolation, nonrecurrent epidemics, and similar dynamical processes on real-world networks. At the heart of the message-passing method is the nonbacktracking matrix, whose largest eigenvalue, the corresponding eigenvector, and the closely related nonbacktracking centrality play a central role in determining how the given dynamical model behaves. Here we propose a degree-class-based method to approximate these quantities using a smaller matrix related to the joint degree-degree distribution of neighboring nodes. Our findings suggest that in most networks, degree-degree correlations beyond nearest neighbor are actually not strong, and our first-order description already results in accurate estimates, particularly when message-passing itself is a good approximation to the original model in question, that is, when the number of short cycles in the network is sufficiently low. We show that localization of the nonbacktracking centrality is also captured well by our scheme, particularly in large networks. Our method provides an alternative to working with the full nonbacktracking matrix in very large networks where this may not be possible due to memory limitations.
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Compression, filtering, and cryptography, as well as the sampling of complex systems, can be seen as processing information. A large initial configuration or input space is nontrivially mapped to a smaller set of output or final states. We explored the statistics of filtering of simple patterns on a number of deterministic and random graphs as a tractable example of such information processing in complex systems. In this problem, multiple inputs map to the same output, and the statistics of filtering is represented by the distribution of this degeneracy. For a few simple filter patterns on a ring, we obtained an exact solution of the problem and numerically described more difficult filter setups. For each of the filter patterns and networks, we found three key numbers that essentially describe the statistics of filtering and compared them for different networks. Our results for networks with diverse architectures are essentially determined by two factors: whether the graphs structure is deterministic or random and the vertex degree. We find that filtering in random graphs produces much richer statistics than in deterministic graphs, reflecting the greater complexity of such graphs. Increasing the graph's degree reduces this statistical richness, while being at its maximum at the smallest degree not equal to two. A filter pattern with a strong dependence on the neighbourhood of a node is much more sensitive to these effects.
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Plastic pollution and the subsequent entanglement of marine animals is a global and increasing problem. In this study we present an analysis of the seabirds recorded as entangled by a rehabilitation centre and an associated marine animal stranding network, along the central coast of Portugal, between 2008 and 2018. Results show a high annual rate of entangled seabirds (average 6.9%) compared to other studies and fisheries related materials are a relevant cause of seabird entanglement (82%) compared to other debris. When comparing age classes, juveniles were more vulnerable to entanglement than other age classes in the species studied. Regarding the rehabilitation of entangled seabirds, the release rate was higher in non-fishing material entanglement cases. In conclusion, this study highlights the impact of fisheries related material on marine fauna and the need for reinforcement of the existing legislation for protecting seabirds and the implementation of mitigation measures associated with fishing activities.
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Pesqueiros , Plásticos , Animais , Aves , Portugal , Prevalência , Resíduos/análiseRESUMO
The structure of an evolving network contains information about its past. Extracting this information efficiently, however, is, in general, a difficult challenge. We formulate a fast and efficient method to estimate the most likely history of growing trees, based on exact results on root finding. We show that our linear-time algorithm produces the exact stepwise most probable history in a broad class of tree growth models. Our formulation is able to treat very large trees and therefore allows us to make reliable numerical observations regarding the possibility of root inference and history reconstruction in growing trees. We obtain the general formula ãlnNãâ NlnN-cN for the size dependence of the mean logarithmic number of possible histories of a given tree, a quantity that largely determines the reconstructability of tree histories. We also reveal an uncertainty principle: a relationship between the inferability of the root and that of the complete history, indicating that there is a tradeoff between the two tasks; the root and the complete history cannot both be inferred with high accuracy at the same time.
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We describe the critical behavior of weak multiplex percolation, a generalization of percolation to multiplex or interdependent networks. A node can determine its active or inactive status simply by referencing neighboring nodes. This is not the case for the more commonly studied generalization of percolation to multiplex networks, the mutually connected clusters, which requires an interconnecting path within each layer between any two vertices in the giant mutually connected component. We study the emergence of a giant connected component of active nodes under the weak percolation rule, finding several nontypical phenomena. In two layers, the giant component emerges with a continuous phase transition, but with quadratic growth above the critical threshold. In three or more layers, a discontinuous hybrid transition occurs, similar to that found in the giant mutually connected component. In networks with asymptotically powerlaw degree distributions, defined by the decay exponent γ, the discontinuity vanishes but at γ=1.5 in three layers, more generally at γ=1+1/(M-1) in M layers.
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Calcinose enzoótica, causada por Nierembergia rivularis, no Uruguai, e Nierembergia veitchii, no Brasil, é uma doença caracterizada por mineralização de tecidos moles, hiperplasia das células parafoliculares da tireoide e elevação nos níveis de cálcio e fósforo. Descreve-se um caso de hiperplasia e carcinoma de células parafoliculares bilateral em um ovino de quatro anos, com calcinose enzoótica associada à intoxicação por Nierembergia rivularis. O diagnóstico histológico de hiperplasia e carcinoma de células parafoliculares é suportado pelas marcações imuno-histoquímicas positivas para calcitonina, peptídeo relacionado ao gene da calcitonina e enolase neurônio específica. Como a hiperplasia de células parafoliculares é uma lesão pré-neoplásica induzida por hipercalcemia, sugere-se que a hipercalcemia crônica causada pela intoxicação por N. rivularis pode ter induzido hiperplasia de células parafoliculares seguida de transformação em carcinoma, neste caso. Os efeitos carcinogênicos das plantas calcinogênicas no sistema endócrino devem ser melhor explorados.(AU)
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Animais , Intoxicação por Plantas/veterinária , Calcinose/veterinária , Ovinos , Neoplasias da Glândula Tireoide/veterinária , Células Epiteliais da Tireoide/patologia , Plantas TóxicasRESUMO
BACKGROUND: Pelvic floor muscles (PFM) and rectus abdominis muscles (RAM) of pregnant diabetic rats exhibit atrophy, co-localization of fast and slow fibers and an increased collagen type I/III ratio. However, the role of similar PFM or RAM hyperglycemic-related myopathy in women with gestational diabetes mellitus (GDM) remains poorly investigated. This study aims to assess the frequency of pelvic floor muscle disorders and pregnancy-specific urinary incontinence (PS-UI) 12 months after the Cesarean (C) section in women with GDM. Specifically, differences in PFM/RAM hyperglycemic myopathy will be evaluated. METHODS: The Diamater is an ongoing cohort study of four groups of 59 pregnant women each from the Perinatal Diabetes Research Centre (PDRC), Botucatu Medical School (FMB)-UNESP (São Paulo State University), Brazil. Diagnosis of GDM and PS-UI will be made at 24-26 weeks, with a follow-up at 34-38 weeks of gestation. Inclusion in the study will occur at the time of C-section, and patients will be followed at 24-48 h, 6 weeks and 6 and 12 months postpartum. Study groups will be classified as (1) GDM plus PS-UI; (2) GDM without PS-UI; (3) Non-GDM plus PS-UI; and (4) Non-GDM without PS-UI. We will analyze relationships between GDM, PS-UI and hyperglycemic myopathy at 12 months after C-section. The mediator variables to be evaluated include digital palpation, vaginal squeeze pressure, 3D pelvic floor ultrasound, and 3D RAM ultrasound. RAM samples obtained during C-section will be analyzed for ex-vivo contractility, morphological, molecular and OMICS profiles to further characterize the hyperglycemic myopathy. Additional variables to be evaluated include maternal age, socioeconomic status, educational level, ethnicity, body mass index, weight gain during pregnancy, quality of glycemic control and insulin therapy. DISCUSSION: To our knowledge, this will be the first study to provide data on the prevalence of PS-UI and RAM and PFM physical and biomolecular muscle profiles after C-section in mothers with GDM. The longitudinal design allows for the assessment of cause-effect relationships between GDM, PS-UI, and PFMs and RAMs myopathy. The findings may reveal previously undetermined consequences of GDM.
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Diabetes Gestacional/fisiopatologia , Doenças Musculares/fisiopatologia , Incontinência Urinária/fisiopatologia , Adulto , Brasil , Cesárea , Estudos de Coortes , Feminino , Idade Gestacional , Ganho de Peso na Gestação , Humanos , Idade Materna , Contração Muscular/fisiologia , Força Muscular/fisiologia , Palpação , Diafragma da Pelve/fisiopatologia , Período Pós-Parto , Gravidez , Reto do Abdome/fisiopatologia , VaginaRESUMO
BACKGROUND: The European Organization for Research and Treatment of Cancer (EORTC) QLQ-BR23 was one of the first disease-specific questionnaires developed in 1996 to assess quality of life (QoL) in patients with breast cancer (BC). However, since 1996 major changes in BC treatment have occurred, requiring an update of the EORTC BC module. This study presents the results of the phase I-III update of the QLQ-BR23 questionnaire. PATIENTS AND METHODS: The update of the EORTC QLQ-BR23 module followed standard EORTC guidelines. A systematic literature review revealed 83 potential relevant QoL issues during phases I and II. After shortening the issues list and following interviews with patients and health care providers, 15 relevant issues were transformed into 27 items. The preliminary module was pretested in an international, multicentre phase III study to identify and solve potential problems with wording comprehensibility and acceptability of the items. Descriptive statistics are provided. Analyses were qualitative and quantitative. We provide a psychometric structure of the items. RESULTS: The phase I and II results indicated the need to supplement the original QLQ-BR23 with additional items related to newer therapeutic options. The phase III study recruited a total of 250 patients (from 12 countries). The final updated phase III module contains a total of 45 items: 23 items from the QLQ-BR23 and 22 new items. The new items contain two multi-item scales: a target symptom scale and a satisfaction scale. The target symptom scale can be divided into three subscales: endocrine therapy, endocrine sexual and skin/mucosa scale. CONCLUSION: Our work has led to the development of a new EORTC QLQ-BR45 module that provides a more accurate and comprehensive assessment of the impact of new and scalable treatments on patients' QoL. The final version of the EORTC QLQ-BR45 is currently available for use in clinical practice. The final phase IV study is underway to confirm psychometric properties of the module.
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Neoplasias da Mama , Qualidade de Vida , Neoplasias da Mama/tratamento farmacológico , Ensaios Clínicos como Assunto , Humanos , Psicometria , Reprodutibilidade dos Testes , Inquéritos e QuestionáriosRESUMO
INTRODUÇÃO: As doenças cardiovasculares estão entre as principais causas de mortalidade global e, dentre elas, destaca-se a doença arterial coronariana (DAC), cujo diagnóstico precoce e prevenção ainda continuam sendo a melhor forma de tratamento. O conhecimento do perfil clínico e angiográfico dos pacientes portadores de DAC é extremamente importante para a avaliação de risco, a partir da quantificação da extensão e gravidade da doença, assim como para o planejamento terapêutico e sucesso do tratamento. O nosso objetivo foi avaliar o perfil clínico e angiográfico dos pacientes submetidos a exame diagnóstico de cineangiocoronariografia em centro clínico de alto volume. MÉTODOS: Foi realizado um estudo retrospectivo e descritivo do perfil clínico-angiográfico dos pacientes >18 anos submetidos à cineangiocoronariografia diagnóstica no Instituto Dante Pazzanese de Cardiologia de janeiro de 2011 a dezembro de 2018, excluindo os pacientes com cirurgia de revascularização prévia e doença valvar associada. Os dados foram obtidos por meio de um banco de dados institucional. RESULTADOS: Um total de 25649 pacientes foram incluídos, sendo 59,4% do sexo masculino, com média das idades de 66,1 anos. Os fatores de risco cardiovasculares mais frequentemente encontrados foram: hipertensão arterial sistêmica (80,5%), dislipidemia (60,5%), diabetes mellitus (32,3%), tabagismo (40,9%), e doença renal crônica (21,5%). O quadro clínico era de angina estável em 32,5%, síndrome coronariana aguda (SCA) sem supra de ST em 20,4% incluindo SCA com supra de ST em 6,1%, e isquemia silenciosa/assintomáticos em 37,5%. Em relação ao perfil angiográfico, a doença arterial coronariana obstrutiva significativa (>50%) foi uni-, bi- ou tri arterial em, respectivamente, 25,7%, 17,5% e 12,22%, além do tronco da coronária esquerda em 1,4%. A partir do exame diagnóstico, a intervenção coronária percutânea (ICP) foi realizada em 14,7% dos pacientes, predominantemente naqueles com apresentação clínica de SCA. Os vasos coronários tratados mais frequentes foram descendente anterior em 40,9%, coronária direita em 29,5% e circunflexa em 23,2%. O sucesso angiográfico foi evidenciado em 99,2% dos casos. Em relação aos desfechos clínicos na fase intra-hospitalar, foi reportado a ocorrência de óbito em 0,3% dos pacientes. CONCLUSÃO: A população estudada apresentou elevada prevalência de fatores de risco cardiovasculares e de doença coronária obstrutiva significativa. Já os pacientes submetidos a ICP subsequente, apresentaram elevada taxa de sucesso no procedimento. (AU)
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Humanos , Cineangiografia , DiagnósticoRESUMO
BACKGROUND: Osteoglycin (OGN, a.k.a. mimecan) belongs to cluster III of the small leucine-rich proteoglycans (SLRP) of the extracellular matrix (ECM). In vertebrates OGN is a characteristic ECM protein of bone. In the present study we explore the evolution of SLRP III and OGN in teleosts that have a skeleton adapted to an aquatic environment. RESULTS: The SLRP gene family has been conserved since the separation of chondrichthyes and osteichthyes. Few gene duplicates of the SLRP III family exist even in the teleosts that experienced a specific whole genome duplication. One exception is ogn for which duplicate copies were identified in fish genomes. The ogn promoter sequence and in vitro mesenchymal stem cell (MSC) cultures suggest the duplicate ogn genes acquired divergent functions. In gilthead sea bream (Sparus aurata) ogn1 was up-regulated during osteoblast and myocyte differentiation in vitro, while ogn2 was severely down-regulated during bone-derived MSCs differentiation into adipocytes in vitro. CONCLUSIONS: Overall, the phylogenetic analysis indicates that the SLRP III family in vertebrates has been under conservative evolutionary pressure. The retention of the ogn gene duplicates in teleosts was linked with the acquisition of different functions. The acquisition by OGN of functions other than that of a bone ECM protein occurred early in the vertebrate lineage.
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Evolução Molecular , Genes Duplicados , Peptídeos e Proteínas de Sinalização Intercelular/genética , Família Multigênica , Dourada/genética , Proteoglicanos Pequenos Ricos em Leucina/genética , Adipócitos/citologia , Adipócitos/metabolismo , Animais , Diferenciação Celular/genética , Células Cultivadas , Sequência Conservada , Perfilação da Expressão Gênica , Ligação Genética , Genoma , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Monócitos/citologia , Monócitos/metabolismo , Filogenia , Regiões Promotoras Genéticas , Alinhamento de Sequência , Proteoglicanos Pequenos Ricos em Leucina/metabolismo , Sintenia/genéticaRESUMO
Salmonellosis is an enteric or multisystemic disease of global distribution that affects numerous animal species. Although Salmonella enterica has been associated with urinary tract lesions in man, information on urocystitis/ureteritis in cattle caused by salmonellae is lacking. This communication describes lesions of the inferior urinary tract in four Holstein calves with septicaemia caused by S. enterica subsp. enterica serotype Dublin. Examination of the urinary bladder revealed either diffuse irregular thickening (three cases) or petechiation (one case) of the mucosa. On histopathological examination, urocystitis with submucosal histiocytic, lymphocytic and plasmacytic infiltration and neutrophil transmigration through the urothelium was noted in all cases. In one case, a fibrinosuppurative ureteritis was detected. Salmonella Dublin was identified by culture, 16S rDNA sequencing and serotyping and Salmonella antigen was detected intralesionally by immunohistochemistry. Other lesions, indicative of septicaemia included hepatitis, enteritis, pericarditis, splenitis, lymphadenitis and pneumonia. We conclude that S. Dublin can be uropathogenic in cattle with septicaemia.
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Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/patologia , Salmonelose Animal/patologia , Sepse/veterinária , Infecções Urinárias/veterinária , Animais , Bovinos , Salmonella entericaRESUMO
INTRODUÇÃO: Recentemente, o conceito dos chamados balões farmacológicos tem sido testado no tratamento da reestenose intra stent, como uma alternativa de tratamento sem implante adicional de outra camada de metal no sítio previamente tratado. Ainda que os balões farmacológicos com paclitaxel tenham se mostrado eficazes para esta finalidade, esta tecnologia ainda apresenta alguns desafios: o paclitaxel é sabidamente menos efetivo e mais tóxico que outros fármacos anti-proliferativos, em especial quando comparado ao sirolimus e seus análogos/derivados. No presente estudo avaliamos um novo balão-farmacológico (Magic Touch), que utiliza sirolimus na dose de 1,27µg/mm2 , depositado em solução excipiente (nano partícula), na concentração de 1:1. MÉTODOS: Estudo prospectivo, multicêntrico, de braço único, incluindo pacientes com reestenose tanto de stents nãofarmacológicos como farmacológicos, tratados com balão Magic Touch. Não foram incluídas reestenoses do tipo oclusiva. Os pacientes foram submetidos a avaliação angiográfica e com ultrassom (USIC) aos seis meses. O desfecho primário foi a avaliação do grau de supressão neointinamal aos seis meses pela angiografia (perda luminal) e USIC (% de obstrução luminal). RESULTADO: Um total de 17 pacientes foram incluídos, sendo a maioria do sexo masculino (59%), com média de idade de 58 anos e com 60% de diabéticos. Metade da população tratada apresentava reestenose de stents farmacológicos e em 62% dos casos a reestenose era do tipo difusa/proliferativa. Sucesso angiográfico foi obtido em 100% dos casos. Aos 6 meses, a mediana da perda luminal tardia intra stent foi de 0,21mm [0,07; 0,51] ao passo que ao USIC, o% de obstrução luminal foi de 20% [18; 24]. Do ponto de vista clínico, ocorreu apenas um óbito, de causa não cardíaca. CONCLUSÃO: Neste estudo inicial em humanos, o balão farmacológico com sirolimus e nano partículas mostrou-se eficaz em reduzir a proliferação neointimal em pacientes com reestenose prévia de stents não-farmacológicos e/ou farmacológicos. (AU)
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Humanos , Reestenose Coronária , Nanocompostos , Stents FarmacológicosRESUMO
Three-dimensional shells can be synthesized from the spontaneous self-folding of two-dimensional templates of interconnected panels, called nets. However, some nets are more likely to self-fold into the desired shell under random movements. The optimal nets are the ones that maximize the number of vertex connections, i.e., vertices that have only two of its faces cut away from each other in the net. Previous methods for finding such nets are based on random search, and thus, they do not guarantee the optimal solution. Here, we propose a deterministic procedure. We map the connectivity of the shell into a shell graph, where the nodes and links of the graph represent the vertices and edges of the shell, respectively. Identifying the nets that maximize the number of vertex connections corresponds to finding the set of maximum leaf spanning trees of the shell graph. This method allows us not only to design the self-assembly of much larger shell structures but also to apply additional design criteria, as a complete catalog of the maximum leaf spanning trees is obtained.
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Message passing equations yield a sharp percolation transition in finite graphs, as an artifact of the locally treelike approximation. For an arbitrary finite, connected, undirected graph we construct an infinite tree having the same local structural properties as this finite graph, when observed by a nonbacktracking walker. Formally excluding the boundary, this infinite tree is a generalization of the Bethe lattice. We indicate an infinite, locally treelike, random network whose local structure is exactly given by this infinite tree. Message passing equations for various cooperative models on this construction are the same as for the original finite graph, but here they provide the exact solutions of the corresponding cooperative problems. These solutions are good approximations to observables for the models on the original graph when it is sufficiently large and not strongly correlated. We show how to express these solutions in the critical region in terms of the principal eigenvector components of the nonbacktracking matrix. As representative examples we formulate the problems of the random and optimal destruction of a connected graph in terms of our construction, the nonbacktracking expansion. We analyze the limitations and the accuracy of the message passing algorithms for different classes of networks and compare the complexity of the message passing calculations to that of direct numerical simulations. Notably, in a range of important cases, simulations turn out to be more efficient computationally than the message passing.
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This study evaluated the effects of environmental pollution on decreasing great tit (Parus major) breeding parameters in an industrial area in the west coast of Portugal. Several great tit breeding parameters were monitored in the industrial area, as well as in a rural area not affected by industrial emissions. Low levels of air pollution in both industrial and rural areas were confirmed by assessing trace element concentrations in pine needles. Concentrations of Cd and Hg in pine needles from the industrial area (Cd = 0.05 ppm; Hg = 0.005 ppm) were significantly lower than those found in needles collected from the reference area (Cd = 0.07 ppm; Hg = 0.007 ppm). Additionally, the breeding success of great tits increased in the industrial area in comparison to the reference area (0.93 ± 0.08 and 0.62 ± 0.22, respectively). The changes on great tit breeding parameters were probably related with changes in the breeding density of other competitive species, together with a decreasing frass-fall biomass. Further long-term ecological studies in industrial areas are necessary to understand the changing breeding performance and strategies used by great tits in response to pollution shifts in the environment.