840 research outputs found
Microfluidic Device for Continuous Magnetophoretic Separation of Red Blood Cells
This paper presents a microfluidic device for magnetophoretic separation red
blood cells from blood under contionous flow. The separation method consist of
continous flow of a blood sample (diluted in PBS) through a microfluidic
channel which presents on the bottom "dots" of feromagnetic layer. By appling a
magnetic field perpendicular on the flowing direction, the feromagnetic "dots"
generates a gradient of magnetic field which amplifies the magnetic force. As a
result, the red blood cells are captured on the bottom of the microfluidic
channel while the rest of the blood is collected at the outlet. Experimental
results show that an average of 95 % of red blood cells are trapped in the
deviceComment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/handle/2042/16838
An analysis of MRI derived cortical complexity in premature-born adults : regional patterns, risk factors, and potential significance
Premature birth bears an increased risk for aberrant brain development concerning its structure and function. Cortical complexity (CC) expresses the fractal dimension of the brain surface and changes during neurodevelopment. We hypothesized that CC is altered after premature birth and associated with long-term cognitive development.
One-hundred-and-one very premature-born adults (gestational age <32 weeks and/or birth weight <1500 ​g) and 111 term-born adults were assessed by structural MRI and cognitive testing at 26 years of age. CC was measured based on MRI by vertex-wise estimation of fractal dimension. Cognitive performance was measured based on Griffiths-Mental-Development-Scale (at 20 months) and Wechsler-Adult-Intelligence-Scales (at 26 years).
In premature-born adults, CC was decreased bilaterally in large lateral temporal and medial parietal clusters. Decreased CC was associated with lower gestational age and birth weight. Furthermore, decreased CC in the medial parietal cortices was linked with reduced full-scale IQ of premature-born adults and mediated the association between cognitive development at 20 months and IQ in adulthood.
Results demonstrate that CC is reduced in very premature-born adults in temporoparietal cortices, mediating the impact of prematurity on impaired cognitive development. These data indicate functionally relevant long-term alterations in the brain’s basic geometry of cortical organization in prematurity
On a three-dimensional and two four-dimensional oncolytic viro-therapy models
We revisit here and carry out further works on tumor-virotherapy
compartmental models of [Tian, 2011, Wang et al., 2013, Phan and Tian, 2017,
Guo et al., 2019]. The results of these papers are only slightly pushed
further. However, what is new is the fact that we make public our electronic
notebooks, since we believe that easy electronic reproducibility is crucial in
an era in which the role of the software becomes very important.Comment: 41 pages, 15 figure
The smart home: how consumers craft new service networks by combining heterogeneous smart domestic products
Service research suggests homes are becoming increasingly connected as consumers automate and personalize new forms of service provision. Yet large-scale empirical evidence on how and why consumers automate smart domestic products is lacking. To address this knowledge gap we analyze 13,905 consumer-crafted, automated combinations of smart domestic products, totaling 1,144,094 installations, across 253 separate service providers on the Web service IFTTT.com. An exploratory network analysis examines the topology of the network and an interpretive coding exercise reveals how consumers craft different styles of human-computer interaction to co-create value. The results reveal the smart domestic product network is disassortative, imbalanced, has a long-tailed degree distribution, and that popular services have high centrality across all product category combinations. We show that popular combinations of smart domestic products are primarily motivated by utilitarian value seeking enacted through a preference for automated tasks outside of conscious attention, though more individualistic combinations are slightly more likely to be hedonistically inclined. We conclude by showing how these consumer-crafted forms of service provision within domestic environments reveal design redundancy and opportunities for service innovation
Recommended from our members
Childhood Adversity is Associated with Left Basal Ganglia Dysfunction During Reward Anticipation in Adulthood
Background: Childhood adversity increases the risk of psychopathology, but the neurobiological mechanisms underlying this vulnerability are not well-understood. In animal models, early adversity is associated with dysfunction in basal ganglia regions involved in reward processing, but this relationship has not been established in humans.
Methods: Functional magnetic resonance imaging was used to examine basal ganglia responses to (a) cues signaling possible monetary rewards and losses, and (b) delivery of monetary gains and penalties, in 13 young adults who experienced maltreatment before age 14 and 31 non-maltreated controls.
Results: Relative to controls, individuals exposed to childhood adversity reported elevated symptoms of anhedonia and depression, rated reward cues less positively, and displayed a weaker response to reward cues in the left globus pallidus. There were no group differences in right hemisphere basal ganglia response to reward cues, or in basal ganglia response to loss cues, no-incentive cues, gains, or penalties.
Conclusions: Results indicate that childhood adversity in humans is associated with blunted subjective responses to reward-predicting cues as well as dysfunction in left basal ganglia regions implicated in reward-related learning and motivation. This dysfunction may serve as a diathesis that contributes to the multiple negative outcomes and psychopathologies associated with childhood adversity. The findings suggest that interventions that target motivation and goal-directed action may be useful for reducing the negative consequences of childhood adversity.Psycholog
BCL11B is required for positive selection and survival of double-positive thymocytes
Transcriptional control of gene expression in double-positive (DP) thymocytes remains poorly understood. We show that the transcription factor BCL11B plays a critical role in DP thymocytes by controlling positive selection of both CD4 and CD8 lineages. BCL11B-deficient DP thymocytes rearrange T cell receptor (TCR) α; however, they display impaired proximal TCR signaling and attenuated extracellular signal-regulated kinase phosphorylation and calcium flux, which are all required for initiation of positive selection. Further, provision of transgenic TCRs did not improve positive selection of BCL11B-deficient DP thymocytes. BCL11B-deficient DP thymocytes have altered expression of genes with a role in positive selection, TCR signaling, and other signaling pathways intersecting the TCR, which may account for the defect. BCL11B-deficient DP thymocytes also presented increased susceptibility to spontaneous apoptosis associated with high levels of cleaved caspase-3 and an altered balance of proapoptotic/prosurvival factors. This latter susceptibility was manifested even in the absence of TCR signaling and was only partially rescued by provision of the BCL2 transgene, indicating that control of DP thymocyte survival by BCL11B is nonredundant and, at least in part, independent of BCL2 prosurvival factors
Recommended from our members
Individual Differences in Reinforcement Learning: Behavioral, Electrophysiological, and Neuroimaging Correlates
During reinforcement learning, phasic modulations of activity in midbrain dopamine neurons are conveyed to the dorsal anterior cingulate Cortex (dACC) and basal ganglia (BG) and serve to guide adaptive responding. While the animal literature supports a role for the dACC in integrating reward history over time, most human electrophysiological Studies of dACC function have focused on responses to single positive and negative outcomes. The present electrophysiological study investigated the role of the dACC in probabilistic reward learning in healthy subjects using a task that required integration of reinforcement history over time. We recorded the feedback-related negativity (FRN) to reward feedback in subjects who developed a response bias toward a more frequently rewarded ("rich") stimulus ("learners") versus subjects who did not ("non-learners"). Compared to non-learners, learners showed more positive (i.e., smaller) FRNs and greater dACC activation upon receiving reward for correct identification of the rich stimulus. In addition, dACC activation and a bias to select the rich Stimulus were positively correlated. The same participants also completed a monetary incentive delay (MID) task administered during functional magnetic resonance imaging. Compared to non-learners, learners displayed stronger BG responses to reward in the MID task. These findings raise the possibility that learners in the probabilistic reinforcement task were characterized by stronger dACC and BG responses to rewarding outcomes. Furthermore, these results highlight the importance of the dACC to probabilistic reward learning in humans.Psycholog
Measuring latency distribution of transcallosal fibers using transcranial magnetic stimulation
Background: Neuroimaging technology is being developed to enable non-invasive mapping of the latency distribution of cortical projection pathways in white matter, and correlative clinical neurophysiological techniques would be valuable for mutual verification. Interhemispheric interaction through the corpus callosum can be measured with interhemispheric facilitation and inhibition using transcranial magnetic stimulation. Objective: To develop a method for determining the latency distribution of the transcallosal fibers with transcranial magnetic stimulation. Methods: We measured the precise time courses of interhemispheric facilitation and inhibition with a conditioning-test paired-pulse magnetic stimulation paradigm. The conditioning stimulus was applied to the right primary motor cortex and the test stimulus was applied to the left primary motor cortex. The interstimulus interval was set at 0.1 ms resolution. The proportions of transcallosal fibers with different conduction velocities were calculated by measuring the changes in magnitudes of interhemispheric facilitation and inhibition with interstimulus interval. Results: Both interhemispheric facilitation and inhibition increased with increment in interstimulus interval. The magnitude of interhemispheric facilitation was correlated with that of interhemispheric inhibition. The latency distribution of transcallosal fibers measured with interhemispheric facilitation was also correlated with that measured with interhemispheric inhibition. Conclusions: The data can be interpreted as latency distribution of transcallosal fibers. Interhemispheric interaction measured with transcranial magnetic stimulation is a promising technique to determine the latency distribution of the transcallosal fibers. Similar techniques could be developed for other cortical pathways
Spectrum of Magnetic Resonance Imaging Findings in Acute Pediatric Traumatic Brain Injury - A Pictorial Essay
Cristina-Mihaela Popescu,1 Virginia Marina,2 Georgiana Avram,3 Carmen Laura Cristescu Budala3 1Dental-Medicine Department, Faculty of Medicine and Pharmacy, “dunărea de Jos” University, GalaČ›i, 800201, Romania; 2Medical Department of Occupational Health, Faculty of Medicine and Pharmacy, “Dunărea de Jos” University, GalaČ›i, 800201, Romania; 3“sf. Ioan” Clinical Emergency Children’s Hospital, GalaČ›i, 800487, RomaniaCorrespondence: Virginia Marina, Tel +40-770-89-82-74, Email [email protected]: Head trauma (HT) in pediatric patients is the number one cause of mortality and morbidity in children. Although computer tomography (CT) imaging provides ample information in assessing acute traumatic brain injuries (TBIs), there are instances when magnetic resonance imaging (MRI) is needed. Due to its high sensitivity in diagnosing small bleeds, MRI offers a well-documented evaluation of primary acute TBIs. Our pictorial essay aims to present some of the latest imaging protocols employed in head trauma and review some practical considerations. Injury mechanisms in accidental HT, lesions’ topography, and hematoma signal variability over time are also discussed. Acute primary intra- and extra-axial lesions and their MRI aspect are showcased using images from patients in our hospital. This pictorial essay has an educational purpose. It is intended to guide young emergency and intensive care unit doctors, neurologists, and neurosurgeons in diagnosing acute primary TBIs on MRI while waiting for the official radiologist’s report. The presentation focuses on the most frequent traumatic lesions encountered in acute pediatric head trauma.Keywords: paediatric head trauma, traumatic brain injury, diffuse axonal injury, haemorrhagic cortical contusions, epidural haematom
- …