215 research outputs found

    Primate modularity and evolution: first anatomical network analysis of primate head and neck musculoskeletal system

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    Network theory is increasingly being used to study morphological modularity and integration. Anatomical network analysis (AnNA) is a framework for quantitatively characterizing the topological organization of anatomical structures and providing an operational way to compare structural integration and modularity. Here we apply AnNA for the first time to study the macroevolution of the musculoskeletal system of the head and neck in primates and their closest living relatives, paying special attention to the evolution of structures associated with facial and vocal communication. We show that well-defined left and right facial modules are plesiomorphic for primates, while anthropoids consistently have asymmetrical facial modules that include structures of both sides, a change likely related to the ability to display more complex, asymmetrical facial expressions. However, no clear trends in network organization were found regarding the evolution of structures related to speech. Remarkably, the increase in the number of head and neck muscles – and thus of musculoskeletal structures – in human evolution led to a decrease in network density and complexity in humans

    Partitioning optimization of proteins from Zea mays malt in ATPS PEG 6000/CaCl2

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    This work aimed to establish the relationship between the compositions and pH of ATPS PEG 6000/CaCl2 and the proteins partition from maize malt and also to simplify the process optimization in ATPS for a statistical model, established by response surface methodology (RSM). Results showed that these were no influence of pH on the phase diagrams and on the composition of tie line length of PEG 6000/CaCl2 ATPS. SRM analyses showed that elevated pH and larger tie line length were the best conditions for recovering of maize malt proteins. The maximum partition coefficient by PEG 6000/CaCl2 ATPS was about 4.2 and was achieved in ATPS in a single purification step. The theoretical maximum partition coefficient was between 4.1-4.3. The process was very suitable for continuous aqueous two phase purification due to the stability of proteins (e.g. alpha and beta-amylases) and could increase their content into middle.50355756

    Study of scattered radiation during fluoroscopy in hip surgery

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    Objetivo: Medir a intensidade da dose de radiação espalhada em diferentes posições simulando uma intervenção cirúrgica no quadril. Materiais e Métodos: Simulou-se uma intervenção cirúrgica no quadril com apoio da fluoroscopia para estudar a distribuição da radiação espalhada no bloco operatório. Para simular o paciente foi utilizado um simulador antropomórfico de corpo inteiro e para medir a radiação utilizou-se um detector específico para medir raios X. Realizaram-se incidências com um equipamento de raios X tipo arco em C móvel, em modo de escopia contínua, com a ampola a 0° (configuração 1) e a 90° (configuração 2). Os parâmetros operacionais utilizados (voltagem, corrente, tempo de exposição) foram determinados por meio de um estudo estatístico resultante da observação de cirurgias ortopédicas de quadril. Resultados: Em todas as medições observaram-se exposições mais elevadas na configuração 2. Nas medições em função da altura, observaram-se os valores máximos da taxa de dose de 1,167 (± 0,023) µSv/s e 2,278 (± 0,023) µSv/s nas configurações 1 e 2, respectivamente, correspondendo à altura do tórax dos profissionais. No estudo em torno do paciente os valores máximos registraramse na posição ocupada pelo médico cirurgião. Conclusão: Concluiu-se que a exposição à radiação dos profissionais é baixa, podendo ainda ser reduzida mediante o uso de equipamentos de proteção individualObjective: To measure the scattered radiation dose at different positions simulating hip surgery. Materials and Methods: We simulated fluoroscopy-assisted hip surgery in order to study the distribution of scattered radiation in the operating room. To simulate the patient, we used a anthropomorphic whole-body phantom, and we used an X-ray-specific detector to quantify the radiation. Radiographs were obtained with a mobile C-arm X-ray system in continuous scan mode, with the tube at 0° (configuration 1) or 90° (configuration 2). The operating parameters employed (voltage, current, and exposure time) were determined by a statistical analysis based on the observation of orthopedic surgical procedures involving the hip. Results: For all measurements, higher exposures were observed in configuration 2. In the measurements obtained as a function of height, the maximum dose rates observed were 1.167 (± 0.023) µSv/s and 2.278 (± 0.023) µSv/s in configurations 1 and 2, respectively, corresponding to the chest level of health care professionals within the operating room. Proximal to the patient, the maximum values were recorded in the position occupied by the surgeon. Conclusion: We can conclude that, in the scenario under study, health care professionals workers are exposed to low levels of radiation, and that those levels can be reduced through the use of personal protective equipmen

    Intra-abdominal pressure in patients with abdominal trauma

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    Objetivos: Pacientes com trauma abdominal tratados cirurgicamente são muito suscetíveis ao desenvolvimento de hipertensão intra-abdominal e síndrome do compartimento abdominal, cujo diagnóstico é baseado na medição da pressão intraabdominal associada a parâmetros clínicos. Este estudo teve por objetivos avaliar prospectivamente o comportamento da pressão intra-abdominal de pacientes com trauma abdominal cirurgicamente tratados e identificar se há relação entre tal comportamento e parâmetros clínicos destes pacientes. Método: A técnica de Kron foi utilizada para medir a pressão intra-abdominal. A casuística foi composta por 17 homens e três mulheres com média de idade de 36,9 anos (D.P. 12,943). O mecanismo de trauma mais freqüente foi contusão abdominal 12 (60%) contra oito (40%) pacientes com ferimentos penetrantes. Os dados foram coletados em 6 e 18 horas de pós-operatório. Resultados: As médias de pressão intra-abdominal foram 10,4 cmH2O (D.P. 3,939) em 6 horas e 10,263 cmH2O (D.P. 3,445) em 18 horas de pós operatório. A análise dos resultados mostrou correlação estatisticamente significante entre o volume de colóides infundidos e a pressão intra-abdominal em 6 e 18 horas pós-operatórias (p = 0,0380 e p = 0,0033 respectivamente). É provável que tal correlação se deva ao edema visceral causado pelo extravasamento capilar de soluções, aumentando a pressão intra-abdominal. Conclusões: Os achados deste estudo ratificam a idéia de relação entre grandes volumes de infusão venosa, sobretudo colóides, e o aumento da pressão intra-abdominal e destacam a importância da avaliação da pressão intra-abdominal em pacientes com trauma abdominal submetidos a grandes reposições volêmicas, sobretudo as soluções coloidais. _________________________________________________________________________________________ ABSTRACT: Bacjground: Patients with significant abdominal traumatism submitted to surgical treatment are susceptible to develop intra-abdominal hypertension and abdominal compartment syndrome. Those diagnosis are based on intra-abdominal pressure measurement associated with clinical parameters. The aims of this study were: to study prospectively the behavior of intra-abdominal pressure in patients with abdominal trauma submitted to surgical treatment; to identify if there is association between that behavior and clinical parameters. Methods: There were 17 males and three females with an average age of 36.9 years (S.D. 12.9). The data was collected in two times, six and 18 hours in the immediate postoperative period. The averages of intra-abdominal pressures found were 10.4 cmH2O (S.D. 3.9) in the first six hours and 10.3 cmH2O (S.D. 3.5) in 18 hours of postoperative period. Results: There was significant statistical correlation between the volume of infused colloids and intra-abdominal pressure at six and 18 hours of postoperative period (p = 0.0380 and p = 0.0033, respectively). These correlations are probably explained by visceral edema caused by the capillary leak of solutions, increasing intra-abdominal pressure. Conclusions: Our findings confirm the relationship between large volumes of fluid infusion, mainly colloid solutions, and the increase of intra-abdominal pressure and detach the importance of intraabdominal pressure monitorization in patients with abdominal trauma submitted to massive replacement of liquids, mainly when this replacement was done with colloids solutions

    Anomalous visual experience is linked to perceptual uncertainty and visual imagery vividness

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    An imbalance between top-down and bottom-up processing on perception (specifically, over-reliance on top-down processing) can lead to anomalous perception, such as illusions. One factor that may be involved in anomalous perception is visual mental imagery, which is the experience of “seeing” with the mind’s eye. There are vast individual differences in self-reported imagery vividness, and more vivid imagery is linked to a more sensory-like experience. We, therefore, hypothesized that susceptibility to anomalous perception is linked to individual imagery vividness. To investigate this, we adopted a paradigm that is known to elicit the perception of faces in pure visual noise (pareidolia). In four experiments, we explored how imagery vividness contributes to this experience under different response instructions and environments. We found strong evidence that people with more vivid imagery were more likely to see faces in the noise, although removing suggestive instructions weakened this relationship. Analyses from the first two experiments led us to explore confidence as another factor in pareidolia proneness. We, therefore, modulated environment noise and added a confidence rating in a novel design. We found strong evidence that pareidolia proneness is correlated with uncertainty about real percepts. Decreasing perceptual ambiguity abolished the relationship between pareidolia proneness and both imagery vividness and confidence. The results cannot be explained by incidental face-like patterns in the noise, individual variations in response bias, perceptual sensitivity, subjective perceptual thresholds, viewing distance, testing environments, motivation, gender, or prosopagnosia. This indicates a critical role of mental imagery vividness and perceptual uncertainty in anomalous perceptual experience. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00426-020-01364-7) contains supplementary material, which is available to authorized users

    The Congenital Cataract-Linked G61C Mutation Destabilizes γD-Crystallin and Promotes Non-Native Aggregation

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    γD-crystallin is one of the major structural proteins in human eye lens. The solubility and stability of γD-crystallin play a crucial role in maintaining the optical properties of the lens during the life span of an individual. Previous study has shown that the inherited mutation G61C results in autosomal dominant congenital cataract. In this research, we studied the effects of the G61C mutation on γD-crystallin structure, stability and aggregation via biophysical methods. CD, intrinsic and extrinsic fluorescence spectroscopy indicated that the G61C mutation did not affect the native structure of γD-crystallin. The stability of γD-crystallin against heat- or GdnHCl-induced denaturation was significantly decreased by the mutation, while no influence was observed on the acid-induced unfolding. The mutation mainly affected the transition from the native state to the intermediate but not that from the intermediate to the unfolded or aggregated states. At high temperatures, both proteins were able to form aggregates, and the aggregation of the mutant was much more serious than the wild type protein at the same temperature. At body temperature and acidic conditions, the mutant was more prone to form amyloid-like fibrils. The aggregation-prone property of the mutant was not altered by the addition of reductive reagent. These results suggested that the decrease in protein stability followed by aggregation-prone property might be the major cause in the hereditary cataract induced by the G61C mutation
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