Recent advances in microfluidic devices for single-cell cultivation: methods and applications.

Single-cell analysis is essential to improve our understanding of cell functionality from cellular and subcellular aspects for diagnosis and therapy. Single-cell cultivation is one of the most important processes in single-cell analysis, which allows the monitoring of actual information of individual cells and provides sufficient single-cell clones and cell-derived products for further analysis. The microfluidic device is a fast-rising system that offers efficient, effective, and sensitive single-cell cultivation and real-time single-cell analysis conducted either on-chip or off-chip. Here, we introduce the importance of single-cell cultivation from the aspects of cellular and subcellular studies. We highlight the materials and structures utilized in microfluidic devices for single-cell cultivation. We further discuss biological applications utilizing single-cell cultivation-based microfluidics, such as cellular phenotyping, cell-cell interactions, and omics profiling. Finally, present limitations and future prospects of microfluidics for single-cell cultivation are also discussed.

Indonesian Student Nurses' E-Health Literacy Skills.

BACKGROUND: Nurses should have a good level of e-health literacy to help patients utilize e-health information. OBJECTIVE: To measure e-health literacy skills and contribute factors. METHODS: A cross-sectional study of 2209 nursing student in Indonesia (October-November 2019) using eHeals. RESULT: The overall eHealth literacy was 4 (Scale 1-5). There were statistically significant differences between e-Heals score with contribute factors (<0.001). CONCLUSION: Indonesian nursing students already have basic necessary skills of e-health.

Focusing of Particles in a Microchannel with Laser Engraved Groove Arrays.

Continuous microfluidic focusing of particles, both synthetic and biological, is significant for a wide range of applications in industry, biology and biomedicine. In this study, we demonstrate the focusing of particles in a microchannel embedded with glass grooves engraved by femtosecond pulse (fs) laser. Results showed that the laser-engraved microstructures were capable of directing polystyrene particles and mouse myoblast cells (C2C12) towards the center of the microchannel at low Reynolds numbers (Re < 1). Numerical simulation revealed that localized side-to-center secondary flows induced by grooves at the channel bottom play an essential role in particle lateral displacement. Additionally, the focusing performance proved to be dependent on the angle of grooves and the middle open space between the grooves based on both experiments and simulation. Particle sedimentation rate was found to critically influence the focusing of particles of different sizes. Taking advantage of the size-dependent particle lateral displacement, selective focusing of micrometer particles was demonstrated. This study systematically investigated continuous particle focusing in a groove-embedded microchannel. We expect that this device will be used for further applications, such as cell sensing and nanoparticle separation in biological and biomedical areas.

Hydrodynamic particle focusing enhanced by femtosecond laser deep grooving at low Reynolds numbers.

Microfluidic focusing of particles (both synthetic and biological), which enables precise control over the positions of particles in a tightly focused stream, is a prerequisite step for the downstream processing, such as detection, trapping and separation. In this study, we propose a novel hydrodynamic focusing method by taking advantage of open v-shaped microstructures on a glass substrate engraved by femtosecond pulse (fs) laser. The fs laser engraved microstructures were capable of focusing polystyrene particles and live cells in rectangular microchannels at relatively low Reynolds numbers (Re). Numerical simulations were performed to explain the mechanisms of particle focusing and experiments were carried out to investigate the effects of groove depth, groove number and flow rate on the performance of the groove-embedded microchannel for particle focusing. We found out that 10-µm polystyrene particles are directed toward the channel center under the effects of the groove-induced secondary flows in low-Re flows, e.g. Re < 1. Moreover, we achieved continuous focusing of live cells with different sizes ranging from 10 to 15 µm, i.e. human T-cell lymphoma Jurkat cells, rat adrenal pheochromocytoma PC12 cells and dog kidney MDCK cells. The glass grooves fabricated by fs laser are expected to be integrated with on-chip detection components, such as contact imaging and fluorescence lifetime-resolved imaging, for various biological and biomedical applications, where particle focusing at a relatively low flow rate is desirable.

Neural signatures of reinforcement learning correlate with strategy adoption during spatial navigation.

Human navigation is generally believed to rely on two types of strategy adoption, route-based and map-based strategies. Both types of navigation require making spatial decisions along the traversed way although formal computational and neural links between navigational strategies and mechanisms of value-based decision making have so far been underexplored in humans. Here we employed functional magnetic resonance imaging (fMRI) while subjects located different objects in a virtual environment. We then modelled their paths using reinforcement learning (RL) algorithms, which successfully explained decision behavior and its neural correlates. Our results show that subjects used a mixture of route and map-based navigation and their paths could be well explained by the model-free and model-based RL algorithms. Furthermore, the value signals of model-free choices during route-based navigation modulated the BOLD signals in the ventro-medial prefrontal cortex (vmPFC), whereas the BOLD signals in parahippocampal and hippocampal regions pertained to model-based value signals during map-based navigation. Our findings suggest that the brain might share computational mechanisms and neural substrates for navigation and value-based decisions such that model-free choice guides route-based navigation and model-based choice directs map-based navigation. These findings open new avenues for computational modelling of wayfinding by directing attention to value-based decision, differing from common direction and distances approaches.

Diarrhea among hospitalized children under five: A call for inclusion of rotavirus vaccine to the national immunization program in Indonesia.

CONTEXT: Rotavirus diarrhea is a common disease worldwide which mostly affects children under five years old. Rotavirus infection causes severe diarrhea and leads to substantial health care costs. In Indonesia the rotavirus vaccine has been available since 2011, however it has not been included into the National Immunization Program. This study aims to describe the proportion of rotavirus in children under 5 in Indonesia, the clinical characteristics of rotavirus infections, and the rotavirus strains circulating in the country during 2010-2015. METHODS: Children under five years of age with acute watery diarrhea were prospectively identified and enrolled through the active diarrhea surveillance system in 5 sites in four provinces in Indonesia during 2010-2015. The rotavirus specimens were tested using Enzyme Immunoassay. Bivariate logistic regression tests were performed to compare rotavirus positive and negative results with respect to the collected demographic and clinical variables. RESULTS: From January 2010 to December 2015, the average annual rotavirus prevalence among children hospitalized with acute watery diarrhea in four provinces in Indonesia was 47.5%. Rotavirus diarrhea occurred mostly in children under 2 years of age. Of all age groups, children aged 6-11 and 12-23 months had the highest prevalence of rotavirus diarrhea in all years (54.2% and 50.6%, respectively). This study found that the most prevalent of G and P genotypes were G1P8 in 2010 (63.2%), 2011 (64.1%) and 2012 (74.6%) and G3P8 in 2013 (49.7%), 2014 (82.5%) and 2015 (84.4%) CONCLUSIONS: This study demonstrates that rotavirus is a major cause of diarrhea in hospitalized children in Indonesia. These findings highlight the need for inclusion of the rotavirus vaccine to the National Immunization Program in Indonesia.