188 research outputs found
Computational haemodynamics in stenotic internal jugular veins
Stenosis in internal jugular veins (IJVs) are frequently associated to pathological venous circulation and insufficient cerebral blood drainage. In this work, we set up a computational framework to assess the relevance of IJV stenoses through numerical simulation, combining medical imaging, patient-specific data and a mathematical model for venous occlusions. Coupling a three-dimensional (3D) description of blood flow in IJVs with a reduced one-dimesional model (1D) for major intracranial veins, we are able to model different anatomical configurations, an aspect of importance to understand the impact of IJV stenosis in intracranial venous haemodynamics. We investigate several stenotic configurations in a physiologic patient-specific regime, quantifying the effect of the stenosis in terms of venous pressure increase and wall shear stress patterns. Simulation results are in qualitative agreement with reported pressure anomalies in pathological cases. Moreover, they demonstrate the potential of the proposed multiscale framework for individual-based studies and computer-aided diagnosis
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Computational haemodynamics in stenotic internal jugular veins
Stenosis in internal jugular veins (IJVs) are frequently associated to
pathological venous circulation and insufficient cerebral blood drainage. In
this work, we set up a computational framework to assess the relevance of IJV
stenoses through numerical simulation, combining medical imaging,
patient-specific data and a mathematical model for venous occlusions.
Coupling a three-dimensional (3D) description of blood flow in IJVs with a
reduced one-dimesional model (1D) for major intracranial veins, we are able
to model different anatomical configurations, an aspect of importance to
understand the impact of IJV stenosis in intracranial venous haemodynamics.
We investigate several stenotic configurations in a physiologic
patient-specific regime, quantifying the effect of the stenosis in terms of
venous pressure increase and wall shear stress patterns. Simulation results
are in qualitative agreement with reported pressure anomalies in pathological
cases. Moreover, they demonstrate the potential of the proposed multiscale
framework for individualbased studies and computer-aided diagnosis
Capacidade de combinação e heterose em híbridos intervarietais de milho adaptados às condições de cerrado.
Quatro experimentos foram conduzidos em 1982/83, com o objetivo de estimar os efeitos das capacidades geral (CGC) e específica (CEC) de combinação, além dos valores da heterose na produção deespigas de cruzamentos dialélicos entre cinco populações de milho tZea mays L.) que estão sendo submetidas a um processo de seleção para as condições de solo sob vegetação" de cerrado. A avaliação foi feita nos locais de Jataí (GO), Goiânia (GO), Jaciara (MT) e Sete Lagoas (MG). Utilizou-se um delineamento em blocos casualizados, com 16 tratamentos e cinco repetições, tendo como testemunha o híbrido duplo comercial Cargill 111. Os tratamentos compreenderam as populações CMS-04,CMS-13, CMS-14, CMS-30 é CMS-36, além dos dez híbridos intervarietais entre elas. Com relação à capacidade geral de combinação, as populações CMS-36 e CMS-30 apresentaram os maiores valores para CGC (361,47 e 66,53). As melhores combinações expressas em relação à CEC foram entre os cruzamentos CMS-04 x CMS-30, CMS-04 x CMS-13 e CMS-D4 x CMS-36, evidenciando que, para este grupo de cruzamentos, epistasia e dominância prevalecem sobre os efeitos génicos aditivos. Os valores percentuais de heterose em relação à média.do pai mais produtivo foram de 5,3%; 3,5% e 8,6% para os cruzamentos citados. A maior heterose (15,7%) foi obtida do cruzamento entre CMS-13 x CMS-36
Long-term effects of bariatric surgery on meal disposal and beta-cell function in diabetic and nondiabetic patients.
Gastric bypass surgery leads to marked improvements in glucose tolerance and insulin sensitivity in obese type 2 diabetes; the impact on glucose fluxes in response to a physiological stimulus - such as a mixed meal (MTT) - has not been determined. We administered an MTT to 12 obese type 2 diabetic patients (T2D) and 15 obese nondiabetic subjects (ND) before and one year after surgery (10 T2D and 11 ND) using the double-tracer technique and modeling of ß-cell function. In both groups postsurgery, tracer-derived appearance of oral glucose was biphasic, a rapid increase followed by a sharp drop, a pattern that was mirrored by postprandial glucose levels and insulin secretion. In diabetic patients, surgery lowered fasting and postprandial glucose levels; peripheral insulin sensitivity increased in proportion to weight loss (∼30%), ß-cell glucose sensitivity doubled but did not normalize (viz. 21 nonsurgical obese and lean controls). Endogenous glucose production, however, was less suppressed during the MMT as the combined result of a relative hyperglucagonemia and the rapid fall in plasma glucose and insulin levels.We conclude that, in type 2 diabetes bypass surgery changes the postprandial response to a dumping-like pattern, improves glucose tolerance, ß-cell function, and peripheral insulin sensitivity but worsens endogenous glucose output in response to a physiological stimulus
Bilateral Primary Spontaneous Pneumothorax. A Case Report
El neumotórax espontáneo primario bilateral simultáneo es una entidad poco frecuente
que representa el 1,3% de los neumotórax espontáneos. La mayoría de los neumotórax
espontáneos bilaterales se consideran secundarios. Se ha descrito en la literatura un número
limitado de casos de neumotórax espontáneo bilateral de naturaleza primaria. Se presenta
el caso de un paciente con neumotórax espontáneo primario bilateral, con una revisión de
la función de las imágenes diagnósticas en este escenario clínico.Simultaneous Bilateral Primary Spontaneous Pneumothorax is a very rate condition,
representing 1.3% of all spontaneous pneumothoraces. Most bilateral spontaneous
pneumothoraces are considered secondary. Very limited cases of bilateral spontaneous
pneumothoraces of a primary nature have been described in literature. We present a case
of a patient with bilateral primary spontaneous pneumothorax, reviewing the sequence of
diagnostic images of this clinical scenario
Attributes of climate resilience in fisheries: from theory to practice
In a changing climate, there is an imperative to build coupled social-ecological systems—including fisheries—that can withstand or adapt to climate stressors. Although resilience theory identifies system attributes that supposedly confer resilience, these attributes have rarely been clearly defined, mechanistically explained, nor tested and applied to inform fisheries governance. Here, we develop and apply a comprehensive resilience framework to examine fishery systems across (a) ecological, (b) socio-economic and (c) governance dimensions using five resilience domains: assets, flexibility, organization, learning and agency. We distil and define 38 attributes that confer climate resilience from a coupled literature- and expert-driven approach, describe how they apply to fisheries and provide illustrative examples of resilience attributes in action. Our synthesis highlights that the directionality and mechanism of these attributes depend on the specific context, capacities, and scale of the focal fishery system and associated stressors, and we find evidence of interdependencies among attributes. Overall, however, we find few studies that test resilience attributes in fisheries across all parts of the system, with most examples focussing on the ecological dimension. As such, meaningful quantification of the attributes’ contributions to resilience remains a challenge. Our synthesis and holistic framework represent a starting point for critical application of resilience concepts to fisheries social-ecological systems
Prevalence of oral cancer self-examination among elderly people treated under Brazil's Unified Health System: household health survey
Este estudo objetivou identificar a prevalência do autoexame bucal entre idosos e constatar se essa prevalência foi maior entre usuários de serviços odontológicos prestados pelo Sistema Único de Saúde (SUS). Estudo transversal conduzido a partir de amostragem probabilística complexa por conglomerados, entre idosos (65-74 anos) de um município brasileiro de grande porte populacional. Foi realizada regressão logística binária, as estimativas foram corrigidas pelo efeito de desenho e por ponderações, utilizando-se o SPSS(r). Dentre os 740 avaliados, atenderam aos critérios de inclusão 492 idosos e, destes, 101 (22,4%) relataram a prática do autoexame bucal. Esta prática foi maior entre idosos usuários dos serviços odontológicos prestados no SUS, entre aqueles com maior renda per capita, os com maior escolaridade, aqueles que utilizavam prótese dentária removível e entre os que não tiveram impactos decorrentes das desordens bucais; foi menor entre os que usaram serviços odontológicos por rotina e os que não possuíam hábito etilista. A prevalência do autoexame bucal entre idosos foi baixa e maior entre aqueles usuários do SUS. O estímulo à adesão a este autocuidado deve ser considerado nas políticas de saúde do idoso vigentes, especialmente entre usuários de serviços particulares, supletivos e filantrópicos20410851098The aim of this study was to examine the prevalence of oral cancer self-examinationamong the elderly and confirm whether prevalence was higher among users of the dental services provided by Brazil's Unified Health System (SUS, acronym in Portuguese). A transversal study of elderly people aged between 65 and 74 years living in a large-sized Brazilian municipality was conducted using simple random sampling. Logistic regression was conducted and results were corrected for sample design and unequal weighting using the SPSS(r) software. The study assessed 740 individuals. A total of 492 met the inclusion criteria, of which 101 (22.4%) reported having performed an oral cancer self-examination. Prevalence was higher among users of the dental services provided by the SUS, higher-income individuals, people with higher levels of education, individuals that used a removable dental prosthesis, and people who had not experienced discomfort attributed to oral condition, and lower among people who sought regular and periodic dental treatment and individuals who did not have a drinking habit. This type of self-care should be encouraged by public health policies which respond to the needs of the elderly, with emphasis on users of private and philanthropic services, and other services outside the public health networ
Association between the use of total dental prosthesis (denture) and the type of oral health care service used by toothless elderly individuals
A reabilitação protética foi prevista pela política nacional de saúde bucal em função da alta prevalência de perda de todos os dentes e do baixo uso de prótese dentária entre idosos. Há necessidade de se avaliar o impacto dessa política de reabilitação. Portanto, objetivou-se investigar se o tipo de serviço odontológico utilizado foi um dos fatores associados ao uso de prótese dentária total entre idosos. Trata-se de um estudo transversal conduzido em uma amostra probabilística de idosos (60 anos ou mais) residentes na zona urbana de um município brasileiro de pequeno porte populacional por examinadores calibrados. Realizaram-se análises descritiva, bivariada e múltipla (Regressão logística - odds ratio - OR). Participaram 287 idosos, destes, 186 (64,8%) faziam uso de prótese dentária total. O uso de prótese dentária total foi associado a maiores chances de uso de serviços odontológicos supletivos ou particulares (OR = 4,19; p < 0,001) e a presença de lesão no palato (OR = 7,52; p = 0,002) e, também, a menores chances em idades maiores ou iguais a 73 anos (OR = 0,52; p = 0,023) e entre os com comprometimento na dimensão incapacidade física do OHIP-14 (OR = 0,20; p = 0,002). O uso de prótese dentária total foi associado ao tipo de serviço odontológico entre idosos, sendo maior o uso entre usuários dos serviços supletivos ou particulares24933453356Oral rehabilitation with dental prosthesis was mandated by national oral health policy in Brazil, due to the high prevalence of total teeth loss and low use of dental prosthesis among the elderly. There is a pressing need to assess the impact of this rehabilitation policy. An attempt was therefore made to investigate if the dental service used was one of the factors associated with the use of total dental prosthesis among the elderly. To achieve this, a cross-sectional study using a probabilistic sample of elderly (60 years and above) urban-area residents of a small city was conducted by qualified examiners. Descriptive, bivariate and multiple (logistic regression/odds ratio - OR) analyses were conducted on 287 elderly people, of which 186 (64.8%) used dental prosthesis. The use of total dental prosthesis was associated with a higher probability of being attended by private dental services (OR = 4.19; p < 0.001) and the presence of lesions on the palate (OR = 7.52; p = 0.002). Conversely, it was associated with lower probability in ages greater than or equal to 73 years (OR = 0.52; p = 0.023) and among those with impairment of OHIP-14 (OR = 0.20; p = 0.002) in the physical disability dimension. The use of total dental prosthesis was associated with the type of dental service used by the elderly, it being greater among private service user
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