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A nanopore device is capable of providing single-molecule level information of an analyte as they translocate through the sensing aperture-a nanometer-sized through-hole-under the influence of an applied electric field. In this study, a silicon nitride (Si

Reconfigurable modular robots, which can actively assemble and disassemble on command, offer the possibility of mesoscale (milliscale and microscale) manufacturing with robustness and controllability. In this study, we present a design of a scalable modular subunit with embedded permanent magnets in a 3-D printed cubic body. The subunit can be wirelessly controlled by an external uniform magnetic field. We also present controlled assembly–disassembly techniques for these subunits. Our modular robotic platform is highly reconfigurable and can create programmable, predetermined patterns based on open-loop control. The 2-D motion planner computes all reachable polyomino shapes from an arbitrary initial configuration and provides the shortest movement sequences to form each shape. Experimental results match computational modeling, demonstrating robust and reproducible behavior of the modular robotic platform that is promising for mesoscale manufacturing applications. Two cube sizes were tested: 10-mm edge lengths and 2.8-mm edge lengths.

In this study, the motion characteristics of soft alginate microrobots were investigated with wireless magnetic fields in complex fluidic environments. Our aim is to explore the various motion modes that arise as a result of shear forces in viscoelastic fluids. Polyacrylamide (PAA), a water-soluble polymer, was characterized to produce a dynamic environment with a non-Newtonian fluid. The robots were fabricated by an extrusion-based microcentrifugal droplet method. We successfully demonstrated the feasibility of both wiggling and tumbling motions using snowman-shaped microbots. It is found that wiggling motion is primarily influenced by the interaction between the viscoelastic fluid environment and the non-uniform magnetization of the microbots. Additionally, it is discovered that modifying the viscoelasticity properties of the fluid can affect the motion behavior of the microbots. Furthermore, we observed that swarms of microbots exhibit non-uniform behavior within complex environments. Our velocity analysis has provided valuable insights into the relationship between applied magnetic fields and motion characteristics, enabling a more realistic understanding of surface locomotion in the context of targeted drug delivery.

PURPOSE This study aimed to identify the decision-making process for consumers participating in sports centers based on an extended goal-directed behavior model (EMGB), and to provide empirical data for establishing effective operation strategies for sports centers, including additional risk perception of consumers during pandemic.METHODS A total of 446 surveys were used as the final sample. For data analysis, SPSS 21.0 and AMOS 21.0 were used for frequency analysis, correlation analysis, confirmatory factor analysis, and structural equation model analysis.RESULTS Except for hypothesis 2 and 9, all of the hypothesis were chosen.CONCLUSIONS The findings suggested that extended goal-oriented behavior models can increase consumers' cognitive and emotional factors through emotional aspirations, suggesting that a lower risk perception of COVID19 increases their desire to participate in sports centers, and provides academic fundamental data on how to increase and activate sports centers.

Pancreatic islet transplantation is a promising strategy for the treatment of type I diabetes. High-mobility group box-1 (HMGB1), highly expressed in islet cells, is a potent immune stimulator in immune rejection. Heme oxygenase-1 (HO1) gene therapy can modulate the release of HMGB1 by altering intracellular molecules for successful cell transplantation. After delivery of the heme oxygenase-1 (HO1) gene to islet cells using an adeno-associated viral vector (AAV), it was evaluated the changes in cytoplasmic Ca

Electrolyte chemistry plays an important role in the transport properties of analytes through nanopores. Here, we report the translocation properties of the protein human serum transferrin (hSTf) in asymmetric LiCl salt concentrations with either positive (C

Lentinula edodes have been cultivated extensively not only in South Korea but also in other Asian countries. In terms of taste and nutrition, it is a valuable mushroom that is comparable to other mushrooms. L. edodes contains various physiologically active compounds that promote human health. One compound, ergothioneine, exerts a powerful antioxidant function that inhibits cellular senescence. As it is not biosynthesized by plants or animals, L. edodes is very important for ergothioneine supply. The L. edodes cultivars Bambithyang (NIFoS 3404) and Sansanhyang (NIFoS 3420) of the National Institute of Forest Science (NIFoS) had higher ergothioneine content than the other cultivars, and 11 strains were obtained using mono-mono hybridization between them. The strains were inoculated into sawdust media to obtain fruiting bodies, and the ergothioneine content of each hybrid strain was confirmed using high-performance liquid chromatography (HPLC) analysis. Among the 11 strains, NIFoS 5108 had a higher ergothioneine content than the parental strains, Bambithyang (NIFoS 3404) and Sansanhyang (NIFoS 3420). This study revealed that it is possible to develop cultivars with improved specific functions using mono-mono hybridization.

This study was systematically conducted to investigate the dependence of mechanical behaviors of double-lap bi-material joints on various environmental conditions, including room temperature dry (R...

Magnetic achiral planar microswimmers can be massively fabricated at low cost and are envisioned to be useful for in vivo biomedical applications. To understand locomotion in representative in vivo environments, we investigated the swimming performance of achiral planar microswimmers in methylcellulose solutions. We observed that these microswimmers displayed very similar swimming characteristics in methylcellulose solutions as in water. Furthermore, this study indicated that the range of precession angles increased as the concentration of MC solution increased. Last, it was demonstrated that achiral planar microswimmers with similar precession angles exhibited nearly the same dimensionless speeds in different concentrations of the methylcellulose solutions. Upon understanding swimmer kinematics, more effective control over the achiral planar microswimmers can be achieved to perform multiple biomedical tasks in in vivo environments.

Chemically coated micro/nanoparticles are often used in medicine to enhance drug delivery and increase drug up-take into specific areas of the body. Using a recently discovered spontaneous symmetry breaking propulsion mechanism, we demonstrate that chemically coated microparticles can swim through mucus solution under precise navigation and that certain functionalizations can dynamically change propulsion behavior. For this investigation biotin, Bitotin-PEG3-amine, and biotin chitosan were chemically functionalized onto the surfaces of magnetic microparticles using an avidin–biotin complex. These chemicals were chosen because they are used prolifically in drug delivery applications, with PEG and chitosan having well known mucoadhesive effects. Coated microparticles were then suspended in mucus synthesized from porcine stomach mucins and propelled using rotating magnetic fields. The relationship between different chemical coatings, microparticle velocity, and controllability were thoroughly explored and discussed. Results indicate that the biotinylated surface coatings altered the propulsion behavior of microparticles, with performance differences interlinked to both magnetic field properties and localized mucus properties. Precisely controlled drug carrying microparticles are envisioned to help supplant traditional drug delivery methods and enhance existing medical techniques utilizing micro/nanoparticles.

Objectives : The adsorption characteristics of Fe, Cd, and Mn in aqueous solution using zeolite and FeS media were investigated by the adsorption isotherm and kinetic model analysis.Methods : The adsorption characteristics of the heavy metals (Fe, Mn, Cd) were investigated using Langmuir or Freundlich adsorption isotherm. The analysis of pseudo-first or pseudo-second order reaction was also attempted to evaluate the rate limiting factor such as molecular diffusion or chemical adsorption on the absorbents.Results and discussion : The adsorption of the heavy metals on the zeolite and FeS media was more suitable for the Langmuir adsorption isotherm, representing that mono-layer absorption on the surface and no interaction between the absorbed solutes. The order of adsorption preference to zeolite was Fe > Cd > Mn, whereas the order of adsorption preference to FeS media was Cd > Fe > Mn. The adsorption kinetics of zeolite and FeS media were more suitable for pseudo-secondary reactions than for pseudo-primary reaction.Conclusions : The absorption capacity of FeS media for the heavy metals (Fe, Cd and Mn) in aqueous solution was higher than that of zeolite. The adsorption pattern was suitable for the Langmuir adsorption isotherm, and has kinetic characteristic by chemisorption.

The purple pigmentation in the epidermis of swollen roots of 'Tsuda' turnip (Brassica rapa subsp. rapa) is induced by light, providing a good system to investigate the genetic mechanism of light-dependent anthocyanin biosynthesis in B. rapa. Here, we identified the R2R3 MYB transcription factor gene PRODUCTION OF ANTHOCYANIN PIGMENT1 (BrPAP1a) as the critical gene in the anthocyanin-defective mutant w68. A nucleotide mutation in the turn region of the R3 domain was screened, which caused an amino acid substitution from glycine to serine (G94S). Functional analysis showed that the interaction of BrPAP1a with two bHLH factors ENHANCER OF GLABRA 3 (BrEGL3) and TRANSPARENT TESTA 8 (BrTT8) were impaired by the mutation. Expression of BrTT8 was activated by BrPAP1a and enhanced by MYB-bHLH-WDR (MBW) complexes, but blocked by the mutation. Furthermore, BrPAP1a directly bound the MYB-recognizing element (MRE) in the BrTT8 promoter, while the G94S substitution caused a loss of DNA-binding activity. Our findings indicate that G94 is required for protein interaction with BrTT8 and BrEGL3 and DNA-binding of BrPAP1a to activate BrTT8 expression, which leads to anthocyanin biosynthesis. Collectively, our data indicate the importance of the highly conserved amino acids within R2R3 MYB proteins in regulating anthocyanin biosynthesis and could aid programs to increase anthocyanins in turnip roots.

Untethered mobile microrobots controlled by an external magnetic gradient field can be employed as advanced biomedical applications inside the human body such as cell therapy, micromanipulation, and noninvasive surgery. Haptic technology and telecommunication, on the other hand, can extend the potentials of untethered microrobot applications. In those applications, users can communicate with the robot operating system remotely to manipulate microrobots with haptic feedback. Haptic sensations artificially constructed by the wirelessly communicated information can assist human operators to experience forces while controlling the microrobots. The proposed system is composed of a haptic device and a magnetic tweezer system, both of which are integrated through a teleoperation technique based on network communication. Users can control the microrobots remotely and feel the haptic interactions with the remote environment in real-time. The 3D haptic environment is reconstructed dynamically by a model-free haptic rendering algorithm using a 2D planar image input of the microscope. The interaction between microrobots and environmental objects is haptically rendered as 3D objects to achieve spatial haptic operation with obstacle avoidance. Moreover, path generation and path guidance forces provide virtual interaction for human users to manipulate the microrobot by following the near-optimal path in path-following tasks. The potential applications of the presented system are medical remote treatment in different sites, remote drug delivery by avoiding physically penetrating through the skin, remotely-controlled cell manipulations, and biopsy without a biopsy needle.

Accomplishing slow translocation speed with high sensitivity has been the most critical mission for solid-state nanopore (SSN) device to electrically detect nucleobases in ssDNA. In this study, a method to detect nucleobases of ssDNA using a 2D SSN is introduced by considerably reducing the translocation speed and effectively increasing its sensitivity. The ultra-thin titanium dioxide coated hexagonal boron nitride nanopore was fabricated, along with an ionic-liquid 1-butyl-3-methylimidazolium hexafluorophosphate/2.0 M KCl aqueous (cis/trans) interface, for increasing both the spatial and the temporal resolutions. As the ssDNA molecules entered the nanopore, a brief surge of electrical conductivity occurred, which was followed by multiple resistive pulses from nucleobases during the translocation of ssDNA and another brief current surge flagging the exit of the molecule. The continuous detection of nucleobases using a 2D SSN device is a novel achievement: the water molecules bound to ssDNA increased the molecular conductivity and amplified electrical signals during the translocation. Along with the experiment, computational simulations using COMSOL Multiphysics are presented to explain the pivotal role of water molecules bound to ssDNA to detect nucleobases using a 2D SSN.

Nanopore probing of molecular level transport of proteins is strongly influenced by electrolyte type, concentration, and solution pH. As a result, electrolyte chemistry and applied voltage are critical for protein transport and impact, for example, capture rate (CR), transport mechanism (i.e., electrophoresis, electroosmosis or diffusion), and 3D conformation (e.g., chaotropic vs. kosmotropic effects). In this study, we explored these using 0.5–4 M LiCl and KCl electrolytes with holo-human serum transferrin (hSTf) protein as the model protein in both low (±50 mV) and high (±400 mV) electric field regimes. Unlike in KCl, where events were purely electrophoretic, the transport in LiCl transitioned from electrophoretic to electroosmotic with decreasing salt concentration while intermediate concentrations (i.e., 2 M and 2.5 M) were influenced by diffusion. Segregating diffusion-limited capture rate (Rdiff) into electrophoretic (Rdiff,EP) and electroosmotic (Rdiff,EO) components provided an approach to calculate the zeta-potential of hSTf (ζhSTf) with the aid of CR and zeta potential of the nanopore surface (ζpore) with (ζpore–ζhSTf) governing the transport mechanism. Scrutinization of the conventional excluded volume model revealed its shortcomings in capturing surface contributions and a new model was then developed to fit the translocation characteristics of proteins., Figure shows hSTf protein translocating through a solid-state nanopore under an applied electric field and the resulting current traces. The transport mechanism is determined by the interplay of electrophoretic and electroosmotic force.

Alloying is one of the powerful methods to exceed the intrinsic properties of pure metals, however, it is challenging to understand the exact alloying effect without altering other parameters, such...

최근 1980년대에 지어진 학교건물에 대한 내진보강을 위한 신공법 개발 및 그 적용에 관한 연구가 활발히 진행 중이다. RC 골조에 압출성형 콘크리트 패널 등을 적용하는 경우에도 조적채움벽과 마찬가지로 RC 골조의 휨 및 전단성능, 이력거동이 달라지질 수 있으므로 면밀한 구조검토가 필요하다. 이 연구에서는 기존 콘크리트 블록 및 경량 콘크리트 블록으로 채움벽을 시공한 비내진 상세 RC 골조에 대한 면내방향 반복가력실험을 수행하였으며, 실험체의 하중-변위 관계, 변위연성비, 에너지 소산량, 변형률 분포의 비교를 통해 조적 객체 종류에 따른 RC 골조의 구조성능을 평가하였다. 실험결과, 조적 객체의 종류에 상관없이 조적채움벽의 시공을 통해 비내진 상세를 가지는 RC 골조의 최대내력과 연성능력이 증진되었으며, 콘크리트 압축강도가 낮더라도 조적 객체의 단위부피가 커지면 RC 골조에 발생하는 균열의 개수와 폭이 상대적으로 감소하여 전체 골조의 수평하중 저항성능이 향상되는 것을 확인하였다. 또한, 비교연구의 결과로부터 새로이 개발한 경량 콘크리트 블록을 적용한 RC 골조는 기존 콘크리트 블록을 적용한 RC골조와 비교해 동등 이상의 내진성능을 가지는 것을 확인하였다.

An external magnetic field can be used in remotely controlling magnetic microrobots, making them promising candidates for diverse biomedical applications, including cell manipulation and therapy. This paper presents a teleoperation scheme to control magnetically actuated microrobots. The system was developed to allow human operators to control the motion for magnetically actuated microrobots and feel their interactions with the environment. The potential applications of the presented system will be in targeted drug delivery, micro-assembly, and biopsy procedures. A haptic interface constituted the core of the teleoperation system. It was used to provide the operator with force feedback to control the microrobots. In particular, virtual interaction forces were computed and transmitted to the human operators to guide them in performing path following tasks. The operating field of the microrobots was haptically rendered to avoid contacts with obstacles. Finally, a basic set of experimental trials were conducted, demonstrating that the average path tracking error was reduced by 67% when haptic feedback was used.