196 research outputs found

    Lab-on-a-chip based integrated hybrid technologies for biofluids manipulation and characterization

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    [EN] The goal of this work is to develop an original and high performance hybrid lab-on-a-chip, coupling actuators and biosensors for the active control and broad range characterization of biofluids samples. These biofluids will be controlled (moved and mixed) actively by Rayleigh-Surface Acoustic Wave (R-SAW) and analysed in real-time by combining Love-SAW (L-SAW) and Surface Plasmon Resonance (SPR) technologies. A microfluidic chamber and specific transducer were designed for this application to interact efficiently with the liquid sample entrapped in the chamber and to detect modifications of its physical properties such as viscosity. AT-cut quartz and LiNbO3 36Y-X substrates were used to generate both Rayleigh and Shear-Horizontal waves and ZnO material as guiding layer. The whole system has proven is full efficiency to interact with the fluid and to detect the signal perturbations with no significant loss compared with the measurements carried out with a probe station.The authors wish to thank the ANR for its financial support through the AWESOM project (ANR-12-BS09-021); the operators Laurent Bouvot, Jean Georges Mussot and Emmanuel Vatoux, for their support and assistance in the fabrication of the cell and the SAW devices; and the engineering students, Olivier Bettoni and Bastien Lafont, for their contribution to the cell design.Rocha Gaso, MI.; Renaudin, A.; Sarry, F.; Beyssen, D. (2015). Lab-on-a-chip based integrated hybrid technologies for biofluids manipulation and characterization. Procedia Engineering. 120:687-690. https://doi.org/10.1016/j.proeng.2015.08.75068769012

    Biosensors to diagnose Chagas disease: A review

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    International audienceChagas disease (CD), which mostly affects underprivileged people, has turned into one 9 of Latin America's main public health problems. Prevention of the disease requires early diagnosis, 10 initiation of therapy, and regular blood monitoring of the infected individual. However, the majority 11 of the infections go undiagnosed because of general mild symptoms and lack of access to medical 12 care. Therefore, more affordable and accessible detection technologies capable of providing early 13 diagnosis and parasite load measurements in settings where CD is prevalent are needed to enable 14 enhanced intervention strategies. This review discusses currently available detection technologies 15 and emerging biosensing technologies for a future application to CD. Even if biosensing 16 technologies still require further research efforts to develop portable systems, we arrive to the 17 conclusion that biosensors could improve diagnosis and the patients' treatment follow-up, in terms 18 of rapidity, small sample volume, high integration, ease of use, real-time and low cost detection 19 compared to current conventional technologies. 2

    A mutual reference shape based on information theory

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    International audienceIn this paper, we propose to consider the estimation of a refer-ence shape from a set of different segmentation results using both active contours and information theory. The reference shape is defined as the minimum of a criterion that benefits from both the mutual information and the joint entropy of the input segmentations and called a mutual shape. This energy criterion is here justified using similarities between informa-tion theory quantities and area measures, and presented in a continuous variational framework. This framework brings out some interesting evaluation measures such as the speci-ficity and sensitivity. In order to solve this shape optimization problem, shape derivatives are computed for each term of the criterion and interpreted as an evolution equation of an active contour. Some synthetical examples allow us to cast the light on the difference between our mutual shape and an average shape. Our framework has been considered for the estimation of a mutual shape for the evaluation of cardiac segmentation methods in MRI

    Cut-Off Values of Anthropometric Indices for the Prediction of Hypertension in a Sample of Egyptian Adults

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    Background: Obesity, particularly abdominal adiposity, is closely associated with premature atherosclerosis and many metabolic modifications including insulin resistance dyslipidemia hypertension and diabetes. Cut-off values for abdominal obesity predicting future cardiovascular disease are known to be population specific.Objective: To identify cut-off points of some anthropometric measurements (BMI, WC, WHR and WHtR) that associated with hypertension in a sample of Egyptian adults.Subjects and Methods: This is a cross-sectional analysis. The blood pressure of 5550 Egyptian adults was measured (2670 females – 2880 males).The subjects represented different geographic localities and different social classes. Anthropometric measurements including height, weight, waist circumferences, and hip circumferences were also measured by practitioners.Results: The cut-off values to detect hypertension in females were 30.08 for BMI, 87.75 for WC , 0.81 for WHR and 0.65 for WHtR, and the corresponding sensitivity and specificity were 69.1; 60.7- 80.9; 48.6 -65.3; 53.4 and 61.4; 58.9, respectively. The cut-off values to detect hypertension in males were 27.98 for BMI, 95.75 for WC, 0.92 for WHR, and 0.57 for WHtR and the corresponding sensitivity and specificity were 62.8; 59.9 -71.9; 51.9 -64.6; 55.8 and 59.7; 55.8, respectively.Conclusion: The BMI, Waist circumference, WHR and WHtR values can predict the presence of hypertension risk in adult Egyptians

    Sensor characterization for multisensor odor-discrimination system

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    In recent years, with the advent of new and cheaper sensors, the use of olfactory systems in homes, industries, and hospitals has a new start. Multisensor systems can improve the ability to distinguish between complex mixtures of volatile substances. To develop multisensor systems that are accurate and reliable, it is important to take into account the anomalies that may arise because of electronic instabilities, types of sensors, and air flow. In this approach, 32 metal oxide semiconductor sensors of 7 different types and operating at different temperatures have been used to develop a multisensor olfactory system. Each type of sensor has been characterized to select the most suitable temperature combinations. In addition, a prechamber has been designed to ensure a good air flow from the sample to the sensing area. The multisensor system has been tested with good results to perform multidimensional information detection of two fruits, based on obtaining sensor matrix data, extracting three features parameters from each sensor curve and using these parameters as the input to a pattern recognition system. (C) 2012 Elsevier B.V. All rights reserved.Cueto Belchí, AD.; Rothpfeffer, N.; Pelegrí Sebastiá, J.; Chilo, J.; García Rodríguez, D.; Sogorb Devesa, TC. (2013). Sensor characterization for multisensor odor-discrimination system. Sensors and Actuators A: Physical. 191:68-72. doi:10.1016/j.sna.2012.11.039S687219

    Hexokinase 3 enhances myeloid cell survival via non-glycolytic functions.

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    The family of hexokinases (HKs) catalyzes the first step of glycolysis, the ATP-dependent phosphorylation of glucose to glucose-6-phosphate. While HK1 and HK2 are ubiquitously expressed, the less well-studied HK3 is primarily expressed in hematopoietic cells and tissues and is highly upregulated during terminal differentiation of some acute myeloid leukemia (AML) cell line models. Here we show that expression of HK3 is predominantly originating from myeloid cells and that the upregulation of this glycolytic enzyme is not restricted to differentiation of leukemic cells but also occurs during ex vivo myeloid differentiation of healthy CD34+ hematopoietic stem and progenitor cells. Within the hematopoietic system, we show that HK3 is predominantly expressed in cells of myeloid origin. CRISPR/Cas9 mediated gene disruption revealed that loss of HK3 has no effect on glycolytic activity in AML cell lines while knocking out HK2 significantly reduced basal glycolysis and glycolytic capacity. Instead, loss of HK3 but not HK2 led to increased sensitivity to ATRA-induced cell death in AML cell lines. We found that HK3 knockout (HK3-null) AML cells showed an accumulation of reactive oxygen species (ROS) as well as DNA damage during ATRA-induced differentiation. RNA sequencing analysis confirmed pathway enrichment for programmed cell death, oxidative stress, and DNA damage response in HK3-null AML cells. These signatures were confirmed in ATAC sequencing, showing that loss of HK3 leads to changes in chromatin configuration and increases the accessibility of genes involved in apoptosis and stress response. Through isoform-specific pulldowns, we furthermore identified a direct interaction between HK3 and the proapoptotic BCL-2 family member BIM, which has previously been shown to shorten myeloid life span. Our findings provide evidence that HK3 is dispensable for glycolytic activity in AML cells while promoting cell survival, possibly through direct interaction with the BH3-only protein BIM during ATRA-induced neutrophil differentiation

    VarGoats project: a dataset of 1159 whole-genome sequences to dissect Capra hircus global diversity

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    Background: Since their domestication 10,500 years ago, goat populations with distinctive genetic backgrounds have adapted to a broad variety of environments and breeding conditions. The VarGoats project is an international 1000-genome resequencing program designed to understand the consequences of domestication and breeding on the genetic diversity of domestic goats and to elucidate how speciation and hybridization have modeled the genomes of a set of species representative of the genus Capra. Findings: A dataset comprising 652 sequenced goats and 507 public goat sequences, including 35 animals representing eight wild species, has been collected worldwide. We identified 74,274,427 single nucleotide polymorphisms (SNPs) and 13,607,850 insertion-deletions (InDels) by aligning these sequences to the latest version of the goat reference genome (ARS1). A Neighbor-joining tree based on Reynolds genetic distances showed that goats from Africa, Asia and Europe tend to group into independent clusters. Because goat breeds from Oceania and Caribbean (Creole) all derive from imported animals, they are distributed along the tree according to their ancestral geographic origin. Conclusions: We report on an unprecedented international effort to characterize the genome-wide diversity of domestic goats. This large range of sequenced individuals represents a unique opportunity to ascertain how the demographic and selection processes associated with post-domestication history have shaped the diversity of this species. Data generated for the project will also be extremely useful to identify deleterious mutations and polymorphisms with causal effects on complex traits, and thus will contribute to new knowledge that could be used in genomic prediction and genome-wide association studies
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