Jitter reduction technique for acoustic radiation force impulse microscopy via photoacoustic detection

We demonstrate a jitter noise reduction technique for acoustic radiation force impulse microscopy via photoacoustic detection (PA-ARFI), which promises to be capable of measuring cell mechanics. To reduce the jitter noise induced by Q-switched pulsed laser operated at high repetition frequency, photoacoustic signals from the surface of an ultrasound transducer are aligned by cross-correlation and peak-to-peak detection, respectively. Each method is then employed to measure the displacements of a target sample in an agar phantom and a breast cancer cell due to ARFI application, followed by the quantitative comparison between their performances. The suggested methods for PA-ARFI significantly reduce jitter noises, thus allowing us to measure displacements of a target cell due to ARFI application by less than 3 μm. © 2015 Optical Society of America.1

Deep Learning-based Synthetic High-Resolution In-Depth Imaging Using an Attachable Dual-element Endoscopic Ultrasound Probe

Endoscopic ultrasound (EUS) imaging has a trade-off between resolution and penetration depth. By considering the in-vivo characteristics of human organs, it is necessary to provide clinicians with appropriate hardware specifications for precise diagnosis. Recently, super-resolution (SR) ultrasound imaging studies, including the SR task in deep learning fields, have been reported for enhancing ultrasound images. However, most of those studies did not consider ultrasound imaging natures, but rather they were conventional SR techniques based on downsampling of ultrasound images. In this study, we propose a novel deep learning-based high-resolution in-depth imaging probe capable of offering low- and high-frequency ultrasound image pairs. We developed an attachable dual-element EUS probe with customized low- and high-frequency ultrasound transducers under small hardware constraints. We also designed a special geared structure to enable the same image plane. The proposed system was evaluated with a wire phantom and a tissue-mimicking phantom. After the evaluation, 442 ultrasound image pairs from the tissue-mimicking phantom were acquired. We then applied several deep learning models to obtain synthetic high-resolution in-depth images, thus demonstrating the feasibility of our approach for clinical unmet needs. Furthermore, we quantitatively and qualitatively analyzed the results to find a suitable deep-learning model for our task. The obtained results demonstrate that our proposed dual-element EUS probe with an image-to-image translation network has the potential to provide synthetic high-frequency ultrasound images deep inside tissues.Comment: 10 pages, 9 figure

Micro solid oxide fuel cell fabricated on porous stainless steel: a new strategy for enhanced thermal cycling ability

Miniaturized solid oxide fuel cells (micro-SOFCs) are being extensively studied as a promising alternative to Li batteries for next generation portable power. A new micro-SOFC is designed and fabricated which shows enhanced thermal robustness by employing oxide-based thin-film electrode and porous stainless steel (STS) substrate. To deposit gas-tight thin-film electrolyte on STS, nano-porous composite oxide is proposed and applied as a new contact layer on STS. The micro-SOFC fabricated on composite oxide- STS dual layer substrate shows the peak power density of 560 mW cm−2 at 550 °C and maintains this power density during rapid thermal cycles. This cell may be suitable for portable electronic device that requires high power-density and fast thermal cycling.1111Ysciescopu

Cell Deformation by Single-beam Acoustic Trapping: A Promising Tool for Measurements of Cell Mechanics

We demonstrate a noncontact single-beam acoustic trapping method for the quantification of the mechanical properties of a single suspended cell with label-free. Experimentally results show that the single-beam acoustic trapping force results in morphological deformation of a trapped cell. While a cancer cell was trapped in an acoustic beam focus, the morphological changes of the immobilized cell were monitored using bright-field imaging. The cell deformability was then compared with that of a trapped polystyrene microbead as a function of the applied acoustic pressure for a better understanding of the relationship between the pressure and degree of cell deformation. Cell deformation was found to become more pronounced as higher pressure levels were applied. Furthermore, to determine if this acoustic trapping method can be exploited in quantifying the cell mechanics in a suspension and in a non-contact manner, the deformability levels of breast cancer cells with different degrees of invasiveness due to acoustic trapping were compared. It was found that highly-invasive breast cancer cells exhibited greater deformability than weakly-invasive breast cancer cells. These results clearly demonstrate that the single-beam acoustic trapping technique is a promising tool for non-contact quantitative assessments of the mechanical properties of single cells in suspensions with label-free.1

Silicon carbide-free graphene growth on silicon for lithium-ion battery with high volumetric energy density

Silicon is receiving discernable attention as an active material for next generation lithium-ion battery anodes because of its unparalleled gravimetric capacity. However, the large volume change of silicon over charge-discharge cycles weakens its competitiveness in the volumetric energy density and cycle life. Here we report direct graphene growth over silicon nanoparticles without silicon carbide formation. The graphene layers anchored onto the silicon surface accommodate the volume expansion of silicon via a sliding process between adjacent graphene layers. When paired with a commercial lithium cobalt oxide cathode, the silicon carbide-free graphene coating allows the full cell to reach volumetric energy densities of 972 and 700 Whl(-1) at first and 200th cycle, respectively, 1.8 and 1.5 times higher than those of current commercial lithium-ion batteries. This observation suggests that two-dimensional layered structure of graphene and its silicon carbide-free integration with silicon can serve as a prototype in advancing silicon anodes to commercially viable technology.

spatio temporal contextualization of queries for microtexts in social media mathematical modeling

Abstract In this paper, we present our ongoing project on query contextualization by integrating all possible IoT-based data sources. Most importantly, mobile users are regarded as the IoT sensors which can be the textual data sources with spatio-temporal contexts. Given a large amount of text streams, it has been difficult for the traditional information retrieval systems to conduct the searching tasks. The goal of this work is i ) to understand and process microtexts in social media (e.g., Twitter and Facebook), and ii ) to reformulate the queries for searching for relevant microtexts in these social media

Social intelligence and pathological gaming: a longitudinal study of the associations among negative emotions, social intelligence, aggression, and pathological gaming in adolescents

IntroductionPathological gaming continues to be highlighted as one of the most critical issues concerning adolescents. Numerous studies have aimed to elucidate the relationships between adolescents' negative emotions (e.g., peer stress, anxiety, loneliness) and social factors (e.g., social skills and relationships) with pathological gaming. Despite the recognition of social intelligence as a crucial factor related to social factors in adolescents, there is a paucity of research examining pathological gaming and social intelligence through longitudinal analyses.MethodThis study focuses on exploring the factors that induce or inhibit pathological gaming among adolescents by analysing three-year longitudinal data from Korean adolescent gamers (N=968). Using a structural equation model, the study examines the relationships between adolescents' negative emotions (e.g., peer stress, anxiety, loneliness), social intelligence, and pathological gaming to elucidate their associations.ResultsThe results indicate that negative emotions can potentially reduce levels of social intelligence and increase aggression. Increased aggression, in turn, appears to be associated with higher levels of pathological gaming. Social intelligence was found to impact pathological gaming potentially negatively and may exert a significantly stronger influence on aggression compared to negative emotions.DiscussionThe study's findings suggest that bolstering adolescents' social aptitude and addressing mental health concerns could serve as beneficial interventions in tackling issues associated with excessive media engagement among youth. These findings suggest that, within the context of adolescent pathological gaming, social intelligence could significantly affect aggression and emerge as a key variable that may lead to pathological gaming