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With its outstanding performance characteristics, the SOFC represents a promising technology for integration into the current energy supply system. For cell development and optimization, a reliable quantitative description of the transport mechanisms and the resulting losses are relevant. The local transport processes are calculated by a 1D model based on the non-equilibrium thermodynamics (NET). The focus of this study is the mass transport in the gas diffusion layers (GDL), which was described as simplified by Fick's law in a previously developed model. This is first replaced by the Dusty-Gas model (DGM) and then by the thermal diffusion (Soret effect) approach. The validation of the model was performed by measuring U,j-characteristics resulting in a maximum deviation of experimental to simulated cell voltage to up to 0.93%. It is shown that, under the prevailing temperature, gradients the Soret effect can be neglected, but the extension to the DGM has to be considered. The temperature and heat flow curves illustrate the relevance of the Peltier effects. At T=1123.15 K and j=8000 A/m2, 64.44% of the total losses occur in the electrolyte. The exergetic efficiency for this operating point is 0.42. Since lower entropy production rates can be assumed in the GDL, the primary need is to investigate alternative electrolyte materials.
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While combination of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) cures most patients with diffuse large B-cell lymphoma (DLBCL), those with high-risk international prognostic index disease have inferior survival. Enzastaurin as a potent inhibitor of PKC-ß and PI3K/AKT pathway suppressor has been tested in many clinical trials including two key studies in DLBCL: Phase III maintenance study (Preventing Relapse in Lymphoma Using Daily Enzastaurin [PRELUDE]) and a first-line Phase II study (S028). DNA extracted from PRELUDE patients' blood samples was retrospectively genotyped identifying a novel genetic biomarker, DGM1 that showed high correlation with response to enzastaurin. A similar finding observed in the S028 study suggested that addition of enzastaurin to R-CHOP may significantly improve outcomes as frontline therapy for high-risk DGM1 positive DLBCL patients. ENGINE is a global, multicenter, placebo-controlled and randomized study to compare the effect of R-CHOP/enzastaurin as frontline treatment in high-risk DLBCL patients. The primary end point for this study is overall survival in patients who are DGM1 positive. Clinical Trial Registration Identifier: NCT03263026.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores Tumorais/genética , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/genética , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Ciclofosfamida/efeitos adversos , Ciclofosfamida/uso terapêutico , Doxorrubicina/efeitos adversos , Doxorrubicina/uso terapêutico , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Indóis/administração & dosagem , Linfoma Difuso de Grandes Células B/diagnóstico , Linfoma Difuso de Grandes Células B/mortalidade , Masculino , Prednisona/efeitos adversos , Prednisona/uso terapêutico , Projetos de Pesquisa , Rituximab/efeitos adversos , Rituximab/uso terapêutico , Vincristina/efeitos adversos , Vincristina/uso terapêuticoRESUMO
OBJECTIVES: Fossils have been linked to Alouatta based on shared cranial morphology and small brain size. However, the relationship between endocranial volume and cranial shape is unclear; it is possible that any platyrrhine with a small brain may exhibit "Alouatta-like" features due to being "de-encephalized." We test two hypotheses: (a) there are aspects of cranial shape related to encephalization common to all platyrrhines; (b) it is these cranial traits that unite the small-brained "Alouatta-like" fossils. MATERIALS AND METHODS: Three-dimensional cranial shape and endocranial volume (ECV) were measured on 350+ extant platyrrhine crania, Cartelles, Paralouatta, and Antillothrix. Encephalization quotient (EQ) was calculated using regressions of ECV on cranial centroid size. Multivariate regressions were performed using the shape coordinates and EQ and shape changes associated with EQ were visualized. Cranial shape was predicted for a hypothetical primate with an EQ matching the fossils and this shape was compared to the Alouatta mean. RESULTS: There is a significant proportion of cranial shape variation explained by EQ in some taxa. The aspects of shape that are correlated with EQ are shared by several taxa and some have parallel regression vectors, but there is no overall pattern of shape change common to all platyrrhines. However, all taxa look more similar to Alouatta when their EQ is decreased, particularly Pithecia. DISCUSSION: Given that a decrease in encephalization can cause a more Alouatta-like cranial shape in many extant platyrrhines, it should not be automatically assumed that Alouatta-like cranial traits in a small-brained fossil are evidence of a phylogenetic link to the alouattin clade.
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Evolução Biológica , Fósseis , Platirrinos/anatomia & histologia , Crânio/anatomia & histologia , Animais , Antropologia Física , Encéfalo/anatomia & histologia , Cefalometria , Feminino , MasculinoRESUMO
Iron is considered to play a key role in the development and progression of Multiple Sclerosis (MS). In particular, iron that accumulates in myeloid cells after the blood-brain barrier (BBB) seals may contribute to chronic inflammation, oxidative stress and eventually neurodegeneration. Magnetic resonance imaging (MRI) is a well-established tool for the non-invasive study of MS. In recent years, an advanced MRI method, quantitative susceptibility mapping (QSM), has made it possible to study brain iron through in vivo imaging. Moreover, immunohistochemical investigations have helped defining the lesional and cellular distribution of iron in MS brain tissue. Imaging studies in MS patients and of brain tissue combined with histological studies have provided important insights into the role of iron in inflammation and neurodegeneration in MS.
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Encéfalo/metabolismo , Ferro/metabolismo , Imageamento por Ressonância Magnética/métodos , Esclerose Múltipla/metabolismo , Animais , Biomarcadores/metabolismo , Encéfalo/patologia , Humanos , Esclerose Múltipla/patologiaRESUMO
In this work, we present the release of a novel easy to use software package called DGM or Directed-Graph-Mapping. DGM can automatically analyze any type of arrhythmia to find reentry or focal sources if the measurements are synchronized in time. Currently, DGM requires the local activation times (LAT) and the spatial coordinates of the measured electrodes. However, there is no requirement for any spatial organization of the electrodes, allowing to analyze clinical, experimental or computational data. DGM creates directed networks of the activation, which are analyzed with fast algorithms to search for reentry (cycles in the network) and focal sources (nodes with outgoing arrows). DGM has been mainly optimized to analyze atrial tachycardia, but we also discuss other applications of DGM demonstrating its wide applicability. The goal is to release a free software package which can allow researchers to save time in the analysis of cardiac data. An academic license is attached to the software, allowing only non-commercial use of the software. All updates of the software, user and installation guide will be published on a dedicated website www.dgmapping.com . Graphical Abstract Direct-Graph-Mapping is a method to automatically analyze a given arrhythmia by converting measured data of the electrodes in a directed network. DGM requires the local activation times (LAT) and the spatial coordinates of the measured electrodes. There is no requirement for any spatial organization of the electrodes, allowing to analyze clinical, experimental or computational data (see left). An example could be the LATs and coordinates from a CARTO file. DGM creates a directed network of the activation by (1) determining the neighbors of each node, 2 (2) allowing a directed arrow between two neighbors if propagation of the electrical wave is possible, (3) repeating this process for all nodes, (4) if necessary, redistributing the nodes more uniformly and repeating step (1)-(3). Two possible steps are (5) to visualize the wavefront by creating an average graph or (6) find the cycles in the network which represent the reentry loops. Focal sources are nodes with only outgoing arrows.
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Taquicardia Supraventricular , Algoritmos , Eletrodos , Humanos , SoftwareRESUMO
OBJECTIVES: Directed graph-mapping (DGM) is a novel operator-independent automatic tool that can be applied to the identification of the atrial tachycardia (AT) mechanism. In the present study, for the first time, DGM was applied in complex AT cases, and diagnostic accuracy was evaluated. BACKGROUND: Catheter ablation of ATs still represents a challenge, as the identification of the correct mechanism can be difficult. New algorithms for high-density activation mapping (HDAM) render an easier acquisition of more detailed maps; however, understanding of the mechanism and, thus, identification of the ablation targets, especially in complex cases, remains strongly operator-dependent. METHODS: HDAMs acquired with the latest algorithm (COHERENT version 7, Biosense Webster, Irvine, California) were interpreted offline by 4 expert electrophysiologists, and the acquired electrode recordings with corresponding local activation times (LATs) were analyzed by DGM (also offline). Entrainment maneuvers (EM) were performed to understand the correct mechanism, which was then confirmed by successful ablation (13 cases were centrifugal, 10 cases were localized re-entry, 22 cases were macro-re-entry, and 6 were double-loops). In total, 51 ATs were retrospectively analyzed. We compared the diagnoses made by DGM were compared with those of the experts and with additional EM results. RESULTS: In total, 51 ATs were retrospectively analyzed. Experts diagnosed the correct AT mechanism and location in 33 cases versus DGM in 38 cases. Diagnostic accuracy varied according to different AT mechanisms. The 13 centrifugal activation patterns were always correctly identified by both methods; 2 of 10 localized reentries were identified by the experts, whereas DGM diagnosed 7 of 10. For the macro-re-entries, 12 of 22 were correctly identified using HDAM versus 13 of 22 for DGM. Finally, 6 of 6 double-loops were correctly identified by the experts, versus 5 of 6 for DGM. CONCLUSIONS: Even in complex cases, DGM provides an automatic, fast, and operator-independent tool to identify the AT mechanism and location and could be a valuable addition to current mapping technologies.
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Ablação por Cateter , Taquicardia Supraventricular , Algoritmos , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/cirurgia , Humanos , Estudos Retrospectivos , Taquicardia Supraventricular/diagnóstico , Taquicardia Supraventricular/cirurgiaRESUMO
BACKGROUND AND PURPOSE: The comparative detection rates of deep gray matter (GM) multiple sclerosis (MS) lesions using double inversion recovery (DIR) and fluid-attenuated inversion-recovery (FLAIR) on 3T MR imaging remain unknown. We aimed to assess the detectability of cortical and deep GM MS lesions using DIR and FLAIR on 3T clinical exams and evaluate the relationship between deep GM lesions and brain atrophy. METHODS: One hundred fifty consecutive MS patients underwent routine brain MRI that included 3D DIR and 2D T2 FLAIR on the same 3T scanner. Three neuroradiologists independently reviewed all exams for cortical and deep GM lesions. Statistical parametric mapping (SPM) and FMRIB software library (FSL)-FIRST pipelines were used to determine normalized whole brain and deep GM volumes. RESULTS: A total of 65 cortical and 98 deep lesions were detected on DIR versus 24 and 20, respectively, on FLAIR. Among all 150 patients, the number and percentage of patients with GM lesions on DIR and FLAIR were as follows: cortical 43 (28.7%) versus 24 (16.0%) (P < .001), thalamus 47 (31.3%) versus 20 (13.3%) (P < .001), putamen 10 (6.7%) versus 3 (2.0%) (P = .02), globus pallidus 9 (6.0%) versus 3 (1.3%) (P = .02), and caudate 5 (3.3%) versus 1 (0.7%) (P = .125). Presence of deep GM lesions weakly correlated with deep GM volume fractions. CONCLUSION: Deep GM MS lesions can be detected using routine clinical brain MRI including DIR and FLAIR at 3T. Future studies to optimize these sequences may improve the detection rates of cortical and deep GM lesions. The presence of GM lesions showed weak correlation with GM atrophy.
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Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/patologia , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Imageamento por Ressonância Magnética , Esclerose Múltipla/diagnóstico por imagem , Esclerose Múltipla/patologia , Adulto , Atrofia , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Atrial fibrillation (AF) is the most frequently encountered arrhythmia in clinical practise. One of the major problems in the management of AF is the difficulty in identifying the arrhythmia sources from clinical recordings. That difficulty occurs because it is currently impossible to verify algorithms which determine these sources in clinical data, as high resolution true excitation patterns cannot be recorded in patients. Therefore, alternative approaches, like computer modelling are of great interest. In a recent published study such an approach was applied for the verification of one of the most commonly used algorithms, phase mapping (PM). A meandering rotor was simulated in the right atrium and a basket catheter was placed at 3 different locations: at the Superior Vena Cava (SVC), the Crista Terminalis (CT) and at the Coronary Sinus (CS). It was shown that although PM can identify the true source, it also finds several false sources due to the far-field effects and interpolation errors in all three positions. In addition, the detection efficiency strongly depended on the basket location. Recently, a novel tool was developed to analyse any arrhythmia called Directed Graph Mapping (DGM). DGM is based on network theory and creates a directed graph of the excitation pattern, from which the location and the source of the arrhythmia can be detected. Therefore, the objective of the current study was to compare the efficiency of DGM with PM on the basket dataset of this meandering rotor. The DGM-tool was applied for a wide variety of conduction velocities (minimal and maximal), which are input parameters of DGM. Overall we found that DGM was able to distinguish between the true rotor and false rotors for both the SVC and CT basket positions. For example, for the SVC position with a CVmin=0.01cmms, DGM detected the true core with a prevalence of 82% versus 94% for PM. Three false rotors where detected for 39.16% (DGM) versus 100% (PM); 22.64% (DGM) versus 100% (PM); and 0% (DGM) versus 57% (PM). Increasing CVmin to 0.02cmms had a stronger effect on the false rotors than on the true rotor. This led to a detection rate of 56.6% for the true rotor, while all the other false rotors disappeared. A similar trend was observed for the CT position. For the CS position, DGM already had a low performance for the true rotor for CVmin=0.01cmms (14.7%). For CVmin=0.02cmms the false and the true rotors could therefore not be distinguished. We can conclude that DGM can overcome some of the limitations of PM by varying one of its input parameters (CVmin). The true rotor is less dependent on this parameter than the false rotors, which disappear at a CVmin=0.02cmms. In order to increase to detection rate of the true rotor, one can decrease CVmin and discard the new rotors which also appear at lower values of CVmin.
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Fibrilação Atrial , Ablação por Cateter , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Catéteres , Átrios do Coração , Sistema de Condução Cardíaco/cirurgia , Humanos , Veia Cava SuperiorRESUMO
An enigmatic feature of tropical pitcher plants belonging to the genus Nepenthes is their dimorphic prey-capturing pitfall traps. In many species, the conspicuously shaped upper and lower pitchers grow from a swollen leaf tendril tip until finally opening as insect-alluring devices. Few have studied the ontogeny of these traps from an anatomical and quantitative morphological perspective. We investigated whether the anatomy and development of lower and upper type pitchers of N. rafflesiana differ or overlap in terms of 3D geometric morphology and microstructure progression and presence. We hypothesized that there is an overlap in the initial, but not all, developmental stages of the two pitcher types and that one pitcher type is suspended in development. We identified four important morphological changes of pitcher ontogeny and defined these as curvation, elongation, inflation and maturation phases. Pitcher length indicated progress through developmental phases, and we propose to use it as a tool for indication of developmental stage. Microstructure development coincided with the developmental phases defined. Additionally, we discovered a new anatomical feature of extrafloral nectariferous peristomal glands between the inner peristome ridges of upper and lower pitchers being hollow and analyze the chemistry of the sugars on the outside of these glands. Ontogenetic shape analysis indicated that upper and lower pitcher types develop with similar phase progression but have no directly overlapping morphology. This means that upper pitchers are not a derived state from lower pitchers. Independent developmental programs evolved to produce distinctly shaped upper and lower pitchers in Nepenthes, likely to exploit different food sources.
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The fate and transport of Hg species in natural aquatic environment are strongly affected by photochemical transformation of Hg0, Hg2+, and MeHg. Migration of Hg is determined by its complexation with organic and inorganic ligands that are widely present in the water. The presence of dissolved organic matter (DOM) is closely related to photochemical reactions of Hg. DOM can strongly bind to mercury (e.g., Hg2+ and MeHg), thus affecting its speciation, mobility and toxicity, eventually dominating its bioavailability. This review summarizes extensive studies on photochemical behaviors of Hg including: (1) photo-oxidation; (2) photo-reduction; (3) photochemical methylation; and (4) MeHg photo-degradation. Photo-oxidation of Hg0 is mostly caused by oxidative free radicals (e.g., â¢OH, CO3â¢-, O3, and 1O2), while photo-reduction of Hg2+ is more complicated and it involves two pathways: (1) primary processes (direct photolysis of Hg2+ or ligand-metal charge transfer of Hg2+-DOM complex); and (2) secondary processes (reduction of Hg2+-DOM complex induced by free radicals derived from DOM photolysis). Photochemical methylation of inorganic Hg occurs as follows: (1) Hg2+ complexes with methyl donors (e.g., acetic acid, tert-butyl, alcohols, etc.) to form intermediates, followed by (2) an intramolecular methyl transfer. MeHg photo-degradation is the leading pathway for MeHg demethylation and it primarily proceeds via four different pathways. The information on DOM was also mentioned, but DOM is not the only factor that affects the photochemical behaviors of Hg. Other influencing factors such as: (1) pH value; (2) dissolved oxygen; (3) cations (Fe3+, K+) and anions (NO3-, HCO3-, CO32-, Cl-); and (4) suspended substance cannot be ignored.
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A discontinuous Galerkin formulation of the Contrast Source Inversion algorithm (DGM-CSI) for microwave breast imaging employing a frequency-cycling reconstruction technique has been modified here to include a set of automated stopping criteria that determine a suitable time to shift imaging frequencies and to globally terminate the reconstruction. Recent studies have explored the use of tissue-dependent geometrical mapping of the well-reconstructed real part to its imaginary part as initial guesses during consecutive frequency hops. This practice was shown to improve resulting 2D images of the dielectric properties of synthetic breast models, but a fixed number of iterations was used to halt DGM-CSI inversions arbitrarily. Herein, a new set of stopping conditions is introduced based on an intelligent statistical analysis of a window of past iterations of data error using the two-sample Kolmogorov-Smirnov (K-S) test. This non-parametric goodness-of-fit test establishes a pattern in the data error distribution, indicating an appropriate time to shift frequencies, or terminate the algorithm. The proposed stopping criteria are shown to improve the efficiency of DGM-CSI while yielding images of equivalent quality to assigning an often liberally overestimated number of iterations per reconstruction.
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Reduced birth weight (RBW) and reduced head circumference (RHC) are adverse birth outcomes (ABOs), often linked to environmental exposures. However, spatial identification of specific health hazards, associated with these ABOs, is not always straightforward due to presence of multiple health hazards and sources of air pollution in urban areas. In this study, we test a novel empirical approach to the spatial identification of environmental health hazards potentially associated with the observed RHC and RBW patterns. The proposed approach is implemented as a systematic search, according to which alternative candidate locations are ranked based on the strength of association with the observed birth outcome patterns. For empirical validation, we apply this approach to the Haifa Bay Area (HBA) in Israel, which is characterized by multiple health hazards and numerous sources of air pollution. We identified a spot in the local industrial zone as the main risk source associated with the observed RHC and RBW patterns. Multivariate regressions, controlling for personal, neighborhood, and geographic factors, revealed that the relative risks of RHC and RBW tend to decline, other things being equal, as a function of distance from the identified industrial spot. We recommend the proposed identification approach as a preliminary risk assessment tool for environmental health studies, in which detailed information on specific sources of air pollution and air pollution dispersion patterns is unavailable due to limited reporting or insufficient monitoring.
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Peso ao Nascer , Cabeça/anatomia & histologia , Exposição Materna/efeitos adversos , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , Monitoramento Ambiental , Feminino , Humanos , Indústrias , Israel , Gravidez , Análise de Regressão , Fatores de RiscoRESUMO
Recently, we developed a method for obtaining the Knudsen diffusion coefficient from the results of tracer experiments with a binary gas system and a porous medium in a column. The developed method employs dusty gas model (DGM) equations that consider molecular diffusion, nonequimolar fluxes, and Knudsen diffusion. The equations derived from the DGM equations for the calculation of the Knudsen diffusion coefficient can also be used to obtain the molecular diffusion coefficient and the ratio of the Knudsen diffusion coefficients of the two chemicals composing the binary gas system. We performed an inversion simulation to fit the advection-diffusion equation to the distribution of molar fractions determined by mathematically solving the advection-diffusion equation. The results confirmed that our method of obtaining the Knudsen diffusion coefficient from tracer experiment results yielded accurate values.
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Atrophy of the brain grey matter (GM) is an accepted and important feature of multiple sclerosis (MS). However, its accurate measurement is hampered by various technical, pathological and physiological factors. As a consequence, it is challenging to investigate the role of GM atrophy in the disease process as well as the effect of treatments that aim to reduce neurodegeneration. In this paper we discuss the most important challenges currently hampering the measurement and interpretation of GM atrophy in MS. The focus is on measurements that are obtained in individual patients rather than on group analysis methods, because of their importance in clinical trials and ultimately in clinical care. We discuss the sources and possible solutions of the current challenges, and provide recommendations to achieve reliable measurement and interpretation of brain GM atrophy in MS.
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Atrofia/patologia , Mapeamento Encefálico , Substância Cinzenta/patologia , Imageamento por Ressonância Magnética , Esclerose Múltipla/patologia , Atrofia/fisiopatologia , Humanos , Imageamento por Ressonância Magnética/métodos , Esclerose Múltipla/fisiopatologia , Substância Branca/patologiaRESUMO
RESEARCH BACKGROUND: Childhood asthma is a chronic disease, known to be linked to prolonged exposure to air pollution. However, the identification of specific health hazards, associated with childhood asthma is not always straightforward, due to the presence of multiple sources of air pollution in urban areas. In this study, we test a novel approach to the spatial identification of environmental hazards that have the highest probability of association with the observed asthma morbidity patterns. METHODS: The effect of a particular health hazard on population morbidity is expected to weaken with distance. To account for this effect, we rank potential health hazards based on the strength of association between the observed morbidity patterns and wind-direction weighted proximities to these locations. We validate this approach by applying it to a study of spatial patterns of childhood asthma in the Greater Haifa Metropolitan Area (GHMA) in Israel, characterised by multiple health hazards. RESULTS: We identified a spot in the local industrial zone as the primary risk source for the observed asthma morbidity patterns. Multivariate regressions, controlling for socio-economic and geographic variables, revealed that the observed incidence rates of asthma tend to decline as a function of distance from the identified industrial location. CONCLUSION: The proposed identification approach uses disease patterns as its main input, and can be used by researches as a preliminary risk assessment tool, in cases in which specific sources of locally elevated morbidity are unclear or cannot be identified by traditional methods.
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Poluição do Ar/efeitos adversos , Asma/epidemiologia , Exposição Ambiental/efeitos adversos , Adolescente , Criança , Cidades , Feminino , Humanos , Israel/epidemiologia , Masculino , Análise EspacialRESUMO
Clear cell renal cell carcinoma (ccRCC) is the most common and most aggressive form of renal cell cancer (RCC). The incidence of RCC has increased steadily in recent years. The pathogenesis of renal cell cancer remains poorly understood. Many of the tumor suppressor genes, oncogenes, and dysregulated pathways in ccRCC need to be revealed for improvement of the overall clinical outlook of the disease. Here, we developed a systems biology approach to prioritize the somatic mutated genes that lead to dysregulation of pathways in ccRCC. The method integrated multi-layer information to infer causative mutations and disease genes. First, we identified differential gene modules in ccRCC by coupling transcriptome and protein-protein interactions. Each of these modules consisted of interacting genes that were involved in similar biological processes and their combined expression alterations were significantly associated with disease type. Then, subsequent gene module-based eQTL analysis revealed somatic mutated genes that had driven the expression alterations of differential gene modules. Our study yielded a list of candidate disease genes, including several known ccRCC causative genes such as BAP1 and PBRM1, as well as novel genes such as NOD2, RRM1, CSRNP1, SLC4A2, TTLL1 and CNTN1. The differential gene modules and their driver genes revealed by our study provided a new perspective for understanding the molecular mechanisms underlying the disease. Moreover, we validated the results in independent ccRCC patient datasets. Our study provided a new method for prioritizing disease genes and pathways.
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INTRODUCTION: Cerebral small vessel disease (cSVD) is associated with microvascular and parenchymal alterations. Intravoxel incoherent motion (IVIM) MRI has been proposed to simultaneously measure both the microvascular perfusion and parenchymal diffusivity. This study aimed to evaluate the application of IVIM in cSVD to assess the microvasculature and parenchymal microstructure. METHODS: Seventy-three patients with cSVD (age 70 ± 11 y) and thirty-nine controls (age 69 ± 12 y) underwent IVIM imaging (3T). Group differences of the perfusion volume fraction f and the parenchymal diffusivity D were investigated using multivariable linear regression accounted for age, sex and cardiovascular factors. To examine the relation between the IVIM measures and the disease severity on structural MRI, white matter hyperintensity (WMH) load served as surrogate measure of the disease severity. RESULTS: Patients had a larger f (p < 0.024) in the normal appearing white matter (NAWM) than controls. Higher D (p < 0.031) was also observed for patients compared with controls in the NAWM and grey matter. Both f (p < 0.024) and D (p < 0.001) in the NAWM and grey matter increased with WMH load. CONCLUSIONS: The increased diffusivity reflects the predicted microstructural tissue impairment in cSVD. Unexpectedly, an increased perfusion volume fraction was observed in patients. Future studies are needed to reveal the precise nature of the increased perfusion volume fraction. IVIM imaging showed that the increases of f and D in cSVD were both related to disease severity, which suggests the potential of IVIM imaging to provide a surrogate marker for the progression of cSVD.
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Doenças de Pequenos Vasos Cerebrais/diagnóstico por imagem , Microvasos/diagnóstico por imagem , Tecido Parenquimatoso/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Imagem de Difusão por Ressonância Magnética , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Movimento (Física) , Perfusão , Estudos Retrospectivos , Substância Branca/diagnóstico por imagemRESUMO
OBJECTIVE Previous meta-analysis has demonstrated that the most important factor in seizure freedom following surgery for focal cortical dysplasia (FCD) is completeness of resection. However, intraoperative detection of epileptogenic dysplastic cortical tissue remains a challenge, potentially leading to a partial resection and the need for reoperation. The objective of this study was to determine the role of intraoperative MRI (iMRI) in the intraoperative detection and localization of FCD as well as its impact on surgical decision making, completeness of resection, and seizure control outcomes. METHODS The authors retrospectively reviewed the medical records of pediatric patients who underwent iMRI-assisted resection of FCD at the Children's National Health System between January 2014 and April 2015. Data reviewed included demographics, length of surgery, details of iMRI acquisition, postoperative seizure freedom, and complications. Postsurgical seizure outcome was assessed utilizing the Engel Epilepsy Surgery Outcome Scale. RESULTS Twelve consecutive pediatric patients (8 females and 4 males) underwent iMRI-guided resection of FCD lesions. The mean age at the time of surgery was 8.8 years ± 1.6 years (range 0.7 to 18.8 years), and the mean duration of follow up was 3.5 months ± 1.0 month. The mean age at seizure onset was 2.8 years ± 1.0 year (range birth to 9.0 years). Two patients had Type 1 FCD, 5 patients had Type 2A FCD, 2 patients had Type 2B FCD, and 3 patients had FCD of undetermined classification. iMRI findings impacted intraoperative surgical decision making in 5 (42%) of the 12 patients, who then underwent further exploration of the resection cavity. At the time of the last postoperative follow-up, 11 (92%) of the 12 patients were seizure free (Engel Class I). No patients underwent reoperation following iMRI-guided surgery. CONCLUSIONS iMRI-guided resection of FCD in pediatric patients precluded the need for repeat surgery. Furthermore, it resulted in the achievement of complete resection in all the patients, leading to a high rate of postoperative seizure freedom.
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Imageamento por Ressonância Magnética , Malformações do Desenvolvimento Cortical/diagnóstico por imagem , Malformações do Desenvolvimento Cortical/cirurgia , Monitorização Intraoperatória , Procedimentos Neurocirúrgicos/métodos , Adolescente , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Imageamento Tridimensional , Lactente , Masculino , Malformações do Desenvolvimento Cortical/complicações , Estudos Retrospectivos , Convulsões/etiologia , Resultado do Tratamento , Adulto JovemRESUMO
This work was carried out to evaluate the effect of different particle size corn on the performance, egg quality and intestinal morphology of Hisex Brown laying hens. A total of 128 birds were used, in a completely randomized design with four treatments, four replicates and eight birds per experimental unit. Experimental rations had corn with different particle size: 565, 620, 781 and 1085 µm of mean geometric diameter (MGD). Feeding was ad libitum at 8:00 am and 4:00 p.m. The variables analyzed were: feed consumption, laying percentage, egg mass and weight, food conversion (was calculated by dividing the feed consumed by the total egg weight (kg.kg-1) and the number of eggs produced (kg.dozen-1)), shell percentage and thickness, Haugh unit, yolk color index and morphometry analysis of the intestinal mucosa. The use of corn with MGD until to 1085 µm in rations does not affect the performance and eggs quality of Hisex Bronw laying hens. However, there are indications that the intestinal morphometry of laying hens is negatively influenced by the increase in particle size of corn.(AU)
Este trabalho foi realizado com o objetivo de avaliar o efeito de diferentes tamanhos de partículas de milho no desempenho, qualidade dos ovos e morfologia intestinal de poedeiras Hisex Brown. Foram utilizadas 128 aves, distribuídas em delineamento inteiramente casualizado, com quatro tratamentos, quatro repetições e oito aves por unidade experimental. As rações experimentais apresentaram milho de diferentes tamanhos de partículas: 565, 620, 781 e 1085 µm de diâmetro geométrico médio (DGM). A alimentação foi ad libitum às 8:00 e 16:00h. As variáveis analisadas foram: consumo de ração, porcentagem de postura, massa e peso dos ovos, conversão alimentar (calculada dividindo-se a ração consumida pelo peso total de ovos (kg/kg) e número de ovos produzidos (kg/dúzia)), porcentagem e espessura da casca, unidade de Haugh, índice e coloração de gema e análise morfométrica da mucosa intestinal. O uso de milho com DGM até 1085 µm nas rações não afeta o desempenho e a qualidade dos ovos de poedeiras Hisex Brown. No entanto, há indicações de que a morfometria intestinal de poedeiras é influenciada negativamente pelo aumento no tamanho das partículas do milho.(AU)
Este estudio ha sido desarrollado con el objetivo de evaluar el efecto de diferentes tamaños de partículas de maíz en el rendimiento, calidad de los huevos y la morfología intestinal de gallinas ponedoras Hisex Brown. Se utilizaron 128 aves, distribuidas en un experimento completamente al azar, con cuatro tratamientos, cuatro repeticiones y ocho aves por unidad experimental. Las raciones experimentales fueron elaboradas con maíz de diferentes tamaños de partículas: 565, 620, 781, 1085 µm de diámetro geométrico medio (DGM). La alimentación fue ad libitum a las 8:00 y a las 16:00h. Las variables analizadas fueron: consumo de ración, porcentaje de postura, masa y peso de los huevos, conversión alimenticia (se calculó dividiendo el alimento consumido por el peso total de huevos (kg/kg) y el número de huevos producidos (kg/docena)), porcentaje y espesor de cáscara, unidad Haugh, índice y coloración de yema, y análisis morfométrica de la mucosa intestinal. La utilización de maíz con DGM de hasta 1085 µm en las raciones no perjudica el rendimiento y la calidad de los huevos de las ponedoras Hisex Brown. Sin embargo, hay indicaciones de que la morfometría intestinal de gallinas ponedoras es influenciada de forma negativa por el aumento del tamaño de las partículas del maíz.(AU)
Assuntos
Animais , Feminino , Óvulo , Aves , Zea mays , Ração Animal/análise , Tamanho da Partícula , EficiênciaRESUMO
Three-dimensional geometric morphometric (3DGM) methods for placing landmarks on digitized bones have become increasingly sophisticated in the last 20 years, including greater degrees of automation. One aspect shared by all 3DGM methods is that the researcher must designate initial landmarks. Thus, researcher interpretations of homology and correspondence are required for and influence representations of shape. We present an algorithm allowing fully automatic placement of correspondence points on samples of 3D digital models representing bones of different individuals/species, which can then be input into standard 3DGM software and analyzed with dimension reduction techniques. We test this algorithm against several samples, primarily a dataset of 106 primate calcanei represented by 1,024 correspondence points per bone. Results of our automated analysis of these samples are compared to a published study using a traditional 3DGM approach with 27 landmarks on each bone. Data were analyzed with morphologika(2.5) and PAST. Our analyses returned strong correlations between principal component scores, similar variance partitioning among components, and similarities between the shape spaces generated by the automatic and traditional methods. While cluster analyses of both automatically generated and traditional datasets produced broadly similar patterns, there were also differences. Overall these results suggest to us that automatic quantifications can lead to shape spaces that are as meaningful as those based on observer landmarks, thereby presenting potential to save time in data collection, increase completeness of morphological quantification, eliminate observer error, and allow comparisons of shape diversity between different types of bones. We provide an R package for implementing this analysis.