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In current work, Prussian blue (PB)- and hydroxyapatite (HAp)-embedded micro-adsorbents (PB-HAp-MAs) were rationally fabricated through an easy and flexible custom-made micronozzle system as a novel bifunctional adsorbent. The adsorption performance of the as–prepared samples was conducted based on the removal of cesium (Cs+) and strontium (Sr2+) ions. Adsorption behaviors of the PB-HAp-MAs were also evaluated as function extrusion dimensions and adsorbate concentration. The adsorption isotherm was well fitted by the Langmuir model with adsorption capacities of 24.688 mg g−1 and 29.254 mg g−1 for Cs+ and Sr2+, respectively. Specially, the enhanced adsorption activity can be synergistically attributed to the porous nature of the developed alginate backbone with a high surface area of encapsulated functional nanoparticles, thus leading to rapid saturation within 1 min. In addition, the as-synthesized PB-HAp-MAs were successfully separated from the aqueous solution within 10 s by applying a magnetic field. We expect that our findings will provide valuable guidelines towards developing highly efficient adsorbents for environmental remediation.

In the present study, spinel cobalt ferrite hierarchical flower-like microspheres (CoFe2O4-MS) are fabricated using a hydrothermal method and utilized as a biocompatible anode in microbial fuel cells (MFCs) for power generation. A maximum power density of 1964 mW m−2 is achieved with CoFe2O4-MS in a mediator-less MFC using Escherichia coli as a biocatalyst and glucose as a fuel. The unprecedented power generation by CoFe2O4-MS can be attributed to (i) the morphology of the flower-like CoFe2O4-MS, with a rough surface and large surface area suitable for biofilm formation, (ii) the rapid immobilization of negatively charged E. coli cells on the positively charged CoFe2O4-MS, facilitating stronger bacterial adhesion between the bacterial cells and CoFe2O4-MS, which leads to lower contact resistance and advantageous interfacial properties with rapid electron transfer, and, more importantly, (iii) enhanced interfacial charge transfer due to the presence of multi-valent cations and multiple valence states in the highly electrocapacitive CoFe2O4-MS. Thus, the enrichment of electroactive E. coli on CoFe2O4-MS produces a large number of electron-shuttling endogenous redox mediators, which promotes efficient extracellular electron transfer between E. coli and the electrocapacitive CoFe2O4-MS during the oxidation of the substrate, thus generating higher power output.

A cytocompatible method of surface-initiated, activator regenerated by electron transfer, atom transfer radical polymerization (SI-ARGET ATRP) is developed for engineering cell surfaces with synthetic polymers. Dopamine-based ATRP initiators are used for both introducing the ATRP initiator onto chemically complex cell surfaces uniformly (by the material-independent coating property of polydopamine) and protecting the cells from radical attack during polymerization (by the radical-scavenging property of polydopamine). Synthetic polymers are grafted onto the surface of individual yeast cells without significant loss of cell viability, and the uniform and dense grafting is confirmed by various characterization methods including agglutination assay and cell-division studies. This work will provide a strategic approach to the generation of living cell-polymer hybrid structures and open the door to their application in multitude of areas, such as sensor technology, catalysis, theranostics, and cell therapy.

Dry cleaning process has been limited to particular field of removing native oxide because it has low etching selectivity for various oxide films. To increase etching selectivity, we added H2O steam feeding step before NF3 feeding step. From the experimental, we can change selectivity between oxide films from tens to hundreds.

The control of marine biofouling has gained significant attention because the uncontrolled adhesion of marine organisms onto synthetic surfaces leads to serious problems. Here, we demonstrate a facile method to inhibit the adhesion of marine organisms using the sulfated polysaccharide, heparin. Heparin was conjugated with an adhesive molecule, catechol, and the resulting adhesive heparin was used as a surface coating for stainless steel, a material commonly used for marine vessels. Immersion of stainless steel surfaces in a solution of adhesive heparin resulted in a stable heparin coating. The marine antifouling property of the surface was confirmed using marine diatom adhesion assays, which revealed that the adhesive heparin coating reduced diatom adhesion by ~75%, as compared with untreated surfaces.

Chemosensors have attracted increasing attention for their usefulness on-site detection and monitoring. In this study, we elucidated a novel, facile, and highly selective Chemo-Paper-Sensor (CPS) for detection and monitoring of strontium (Sr(2+)) ions, which means a potent colorimetric sensor based on a Chrysoidine G (CG)-coated paper strip. The CPS for highly selective colorimetric detection of strontium ion was handily analyzed to determine the red-green-blue (RGB) value using portable devices such as desktop digital scanner and mobile phone camera, quantitatively. Interestingly, an orange to dark orange color transition was observed when the aqueous and solid paper colorimetric sensor was introduced to Sr(2+) ion, respectively. It was demonstrated that the value of the signal has a linear relationship with concentrations of the strontium in the 500 ppm to 100 ppb range with a detection limit of 200 ppb. We believe that a newly developed Chemo-Paper-Sensor will be useful in a wide range of sensing applications.

We present a simple synthetic approach for the preparation of monodisperse thermosensitive gelatin microspheres in a microfluidic system. Based on the mechanism of shear force-driven break-off, aqueous droplets of a gelatin solution were continuously produced in an immiscible continuous fluid. Under cooling conditions, the gelatin droplets solidified into hydrogel microspheres, which resulted from the aggregation or crystallization of collagen folds. The produced gelatin microspheres possess a high monodispersity and fast response to environmental temperature. In addition, the size of the prepared microspheres can be manipulated by altering the flow rate of the continuous phase or aqueous phase, and the physical strength of the gelatin microspheres can be controlled by simply changing the gelatin concentration. Furthermore, this approach enables the preparation of monodisperse microspheres with the ability to exhibit different thermosensitivities and encapsulate colloidal particles under mild conditions, which demonstrate sequential release of the desired encapsulants according to the responsive temperature.

The exceptional mechanical properties of the byssus—the fibrous holdfast of mussels that provides underwater adhesion—have potential applications in medicine and technology. The catechol–Fe3+–catechol interaction underlies the unique properties of mussel byssus and has emerged as a tool for developing functional hybrid materials such as pH-responsive, self-healing gels. Herein, the construction of functional alginate (Alg) film on a solid substrate inspired by mussel byssus is reported. The approach consists of spin-coating-assisted deposition of Alg catechols onto a solid substrate and their subsequent crosslinking via catechol–Fe3+–catechol interactions. This yields robust and multilayered Alg films that are resistant to protein adsorption and suppress bacterial adhesion. This method can be used to create antibacterial films for coating implanted medical devices.

Most agricultural traits are controlled by quantitative trait loci (QTLs); however, there are few studies on QTL mapping of horticultural traits in pepper (Capsicum spp.) due to the lack of high-density molecular maps and the sequence information. In this study, an ultra-high-density map and 120 recombinant inbred lines (RILs) derived from a cross between C. annuum ‘Perennial’ and C. annuum ‘Dempsey’ were used for QTL mapping of horticultural traits. Parental lines and RILs were resequenced at 18× and 1× coverage, respectively. Using a sliding window approach, an ultra-high-density bin map containing 2,578 bins was constructed. The total map length of the map was 1,372 cM, and the average interval between bins was 0.53 cM. A total of 86 significant QTLs controlling 17 horticultural traits were detected. Among these, 32 QTLs controlling 13 traits were major QTLs. Our research shows that the construction of bin maps using low-coverage sequence is a powerful method for QTL mapping, and that the short intervals between bins are helpful for fine-mapping of QTLs. Furthermore, bin maps can be used to improve the quality of reference genomes by elucidating the genetic order of unordered regions and anchoring unassigned scaffolds to linkage groups.

Three-dimensional (3D) in vitro model systems such as spheroids and organoids provide an opportunity to extend our physiological understanding using recapitulated tissues that mimic physiological characteristics of in vivo microenvironments. Unlike two-dimensional (2D) systems, 3D in vitro systems can bridge the gap between inadequate 2D cultures and the in vivo environments, providing novel insights on complex physiological mechanisms at various scales of organization, ranging from the cellular, tissue-, to organ-levels. To satisfy the ever-increasing need for highly complex and sophisticated systems, many 3D in vitro models with advanced microengineering techniques have been developed to answer diverse physiological questions. This review summarizes recent advances in engineered microsystems for the development of 3D in vitro model systems. We highlight and discuss in detail the relationship between the underlying physics behind the microengineering techniques, and their ability to recapitulate distinct 3D cellular structures and functions of diverse types of tissues and organs. We also introduce a number of 3D in vitro models and their engineering principles. Finally, we summarize current limitations, and provide perspectives for future directions in guiding the development of 3D in vitro model systems using microengineering techniques.

MXenes have very recently emerged as an intriguing family of graphene-like two-dimensional (2D) layer-structured transition metal carbides and/or nitrides with a high specific surface area, a large interlayer spacing, hydrophilicity, and abundant highly active surface sites, and they have found a niche in environmental remediation, as materials capable of efficiently removing and sequestering heavy metals, dyes, and radioactive nuclides. With exceptional surface tunable chemical compatibility and compositional flexibility, MXenes are resistant to radiation-induced damage and show high chemical compatibility and excellent thermal stability. They are thought to have the potential to serve as ideal adsorbents for a plethora of radionuclides such as uranium (238U), thorium (232Th), cesium (137Cs), and strontium (90Sr) with respect to technology and the economy. In this article, we comprehensively review state-of-the-art research progress on and the promising potential of MXenes as an adsorbent for the removal of radioactive nuclides from the environment. First, we discuss the structure, synthesis, intercalation/delamination and properties of MXenes. Subsequently, we emphasize their radionuclide removal applications. Finally, we present an outlook on the current challenges in the use of MXene materials for the adsorptive remediation of radionuclides and outline future opportunities for these materials. This article presents a timely and systematic review of MXenes as efficient and cost-effective radionuclide adsorbents. Furthermore, it highlights the main challenges in their use for environmental remediation and provides possible research directions.

In this research, we successfully synthesized a reduced graphene oxide/tin oxide (rGO/SnO2) composite for the electrochemical detection of fungal contaminant, patulin (PAT) that does not require a biological or chemical receptor or specific antibodies. The resulting rGO/SnO2 composite exhibited promising electrochemical properties and demonstrated outstanding performance in the direct measurement of PAT levels in contaminated apple juice samples. The differential pulse voltammetric response of the rGO/SnO2 composite electrode exhibited a linear relationship with PAT concentration in the 50–600 nM range and had a lower detection limit of 0.6635 nM. The sensor electrode exhibited high sensitivity, reliable reproducibility, and good selectivity. The designed electrochemical sensor was also tested against the time-consuming and conventional high-performance liquid chromatography (HPLC) approach for the detection of PAT in spiked apple juice samples. We found that the electrochemical sensor had ability to rapidly detect PAT in apple juice samples without the need of extraction or clean-up steps and achieved a higher recovery rate (74.33 ± 0.70 to 99.26 ± 0.70%) within a short-time analysis than did by the HPLC (61.97 ± 1.78 to 84.31 ± 1.96%), thus illustrating its feasibility for use in agricultural and food safety industries.

The increasing prevalence of Alzheimer&rsquo, s disease (AD) has become a global phenomenon presenting serious social and health challenges. For detecting early molecular changes in the disease, several techniques to measure varied species of amyloid beta in the peripheral blood have been recently developed, but the efforts to associate them with cognitive assessments have yet to produce sufficient data. We prospectively collected participants from the consecutive population who visited our center for brain health screening. In total, 97 participants (F:M = 58:39) aged 69.4 &plusmn, 7.52 were assessed. Participants performed the Korean version of the Consortium to Establish a Registry for Alzheimer&rsquo, s disease (CERAD-K), the clinical dementia rating (CDR), plasma oligomeric amyloid-&beta, (OA&beta, ) level tests, routine blood tests, ApoE genotype, and brain MRI. Among total population, 55.7% had a CDR of 0, and 40.2% had a CDR of 0.5. The results showed that word memory and word recall, and the total scores of the CERAD-K were negatively correlated with the plasma OA&beta, level. With a cut-off value of 0.78 ng/mL for the OA&beta, level and a &minus, 1.5 standard deviation of age/sex/education adjusted norms for the CERAD-K, naming, word memory, word recall, word recognition, and total score were significantly correlated with the OA&beta, level. No correlation between the OA&beta, level and mini-mental status examination was found. Our results demonstrate that the level of plasma OA&beta, was well correlated with the measure of cognitive function through the CERAD-K in the field data collected from consecutive populations. Studies on longitudinal comparisons with large cohorts will further validate the diagnostic value of plasma OA&beta, as a useful biomarker for screening AD and predicting progression.

Inorganic perovskite nanocrystals (NCs) of cesium lead mixed halides (CsPb(X/Y)3, X = Br, Y = Cl and I) are promising optical materials for developing the high-performance photonic devices. Traditionally, anion-exchange reaction in perovskite halide NCs provides a simple substitutional way to tune the composition and emitting color with good luminescence properties in the human eye detectable visible spectral regions. However, prior synthetic procedures of perovskite NCs have employed conventional flask-based reactions which limit the fine control of perovskite NCs because of extremely fast anion-exchange kinetics. To overcome such problems, we demonstrate a droplet-based microfluidic system with simple, fast, and high-throughput parametric screening for the synthesis of perovskite NCs. By using the customized microfluidic operational system consisting of serially integrated two microfluidic reactors and heating block, we have successfully synthesized CsPbX3 perovskite NCs. In addition, we can finely control the anion-exchange reaction which can generate the formation of CsPb(X/Y)3 perovskite NCs with a wide range of visible spectrum (410–630 nm). Ultimately, we have established their potential applications in the development of solid-state lighting-based flexible display systems.

Development of advanced cell culture methods has gained increasing attention because it allows for efficient genetic engineering and precise regulation of animal reproduction on a cellular basis. Numerous studies have attempted to develop an advanced cell culture method. Previous studies have altered cell culture media and pretreated culture plates with functional molecules. Among them, a mussel-inspired polymer coating has been extensively utilized owing to its wide applicability. For instance, adhesion of human embryonic stem cells and neuronal cells on solid surfaces has been improved. Despite the excellent capability of the mussel-inspired polymer coating, most studies have primarily focused on mammalian cells. However, the efficacy of these coatings on the adhesion of other cell lines is yet unclear. This study aimed to assess the potential of the mussel-inspired polymer coating in the regulation of the adhesion of fish ovarian germline stem cells on solid surfaces. Solid surfaces were coated by polydopamine and poly-L-lysine, and the effect of the coatings on cellular behaviors was investigated.

The qualitative and quantitative evaluation of the physicochemical parameters associated with the pathogenicity of high-aspect-ratio nanomaterials is important for comprehensive regulation efforts and safety-by-design approaches. Here, we report quantitative data on the correlations between the rigidity of these nanomaterials and toxicity endpoints in vitro and in vivo. As measured by new ISO standards published in 2017, rigidity shows a strong positive correlation with inflammogenic potential, as indicated by inflammatory cell counts and IL-1β (a biomarker for frustrated phagocytosis) levels in both the acute and chronic phases. In vitro experiments using differentiated THP-1 cells find that only highly rigid multiwalled carbon nanotubes (MWCNTs) and asbestos fibers lead to piercing and frustrated phagocytosis. Thus, this study suggests a bending ratio of 0.97 and a static bending persistence length of 1.08 as threshold rigidity values for asbestos-like pathogenicity. However, additional research using MWCNTs with rigidity values that lie between those of non-inflammogenic ( Db = 0.66 and SBPL = 0.87) and inflammogenic fibers ( Db = 0.97 and SBPL = 1.09) is required to identify more accurate threshold values, which would be useful for comprehensive regulation and safety-by-design approaches based on MWCNTs.

The primary objective of this review article is to summarize the development and structural diversity of 2D/3D molybdenum disulfide (MoS2) based modified electrodes for electrochemical sensors and biosensor applications. Hydrothermal, mechanical, and ultrasonic techniques and solution-based exfoliation have been used to synthesize graphene-like 2D MoS2 layers. The unique physicochemical properties of MoS2 and its nanocomposites, including high mechanical strength, high carrier transport, large surface area, excellent electrical conductivity, and rapid electron transport rate, render them useful as efficient transducers in various electrochemical applications. The present review summarizes 2D/3D MoS2-based nanomaterials as an electrochemical platform for the detection and analysis of various biomolecules (e.g., neurotransmitters, NADH, glucose, antibiotics, DNA, proteins, and bacteria) and hazardous chemicals (e.g., heavy metal ions, organic compounds, and pesticides). The substantial improvements that have been achieved in the performance of enzyme-based amperometry, chemiluminescence, and nucleic acid sensors incorporating MoS2-based chemically modified electrodes are also addressed. We also summarize key sensor parameters such as limits of detection (LODs), sensitivity, selectivity, response time, and durability, as well as real applications of the sensing systems in the environmental, pharmaceutical, chemical, industrial, and food analysis fields. Finally, the remaining challenges in designing MoS2 nanostructures suitable for electroanalytical applications are outlined. Graphical abstract • MoS2 based materials exhibit high conductivity and improved electrochemical performance with great potential as a sensing electrode. • The role of MoS2 nanocomposite films and their detection strategies were reviewed. • Biomarkers detection for disease identification and respective clinical treatments were discussed. • Future Challenges, as well as possible research development for "MoS2 nanocomposites", are suggested.

In this work, we elucidate polymer-layered hollow Prussian blue-coated magnetic nanocomposites as an adsorbent to remove radioactive cesium from environmentally contaminated water. To do this, Fe3O4 nanoparticles prepared using a coprecipitation method were thickly covered with a layer of cationic polymer to attach hollow Prussian blue through a self-assembly process. The as-synthesized adsorbent was confirmed through various analytical techniques. The adsorbent showed a high surface area (166.16 m2/g) with an excellent cesium adsorbent capacity and removal efficiency of 32.8 mg/g and 99.69%, respectively. Moreover, the superparamagnetism allows effective recovery of the adsorbent using an external magnetic field after the adsorption process. Therefore, the magnetic adsorbent with a high adsorption efficiency and convenient recovery is expected to be effectively used for rapid remediation of radioactive contamination.

Current trends in the application of nanomaterials are emerging in the nano-biotechnological sector for development of medicines. Cyanobacteria (blue-green algae) are photosynthetic prokaryotes that have applications to human health and numerous biological activities as dietary supplements. Cyanobacteria produce biologically active and chemically diverse compounds such as cyclic peptides, lipopeptides, fatty acid amides, alkaloids, and saccharides. More than 50% of marine cyanobacteria are potentially exploitable for the extraction of bioactive substances, which are effective in killing cancer cells by inducing apoptotic death. The current review emphasizes that not even 10% of microalgal bioactive components have reached commercialized platforms due to difficulties related to solubility. Considering these factors, they should be considered as a potential source of natural products for drug discovery and drug delivery approaches. Nanoformulations employing a wide variety of nanoparticles and their polymerized forms could be an emerging approach to the development of new cancer drugs. This review highlights recent research on microalgae-based medicines or compounds as well as their biomedical applications. This review further discusses the facts, limitations, and commercial market trends related to the use of microalgae for industrial and medicinal purposes.

The control of biofouling, which is the unwanted adsorption of biomolecules and organisms on solid surfaces, is a prerequisite for wider applicability of the functional materials that are currently being used in biomedical industries. One of the frequently used methods for controlling biofouling is the use of surface coatings with antifouling materials. Herein, fucoidan, which is a marine-derived polysaccharide, is reported as a new type of antifouling material that is safe and broadly applicable. Fucoidan is conjugated with catechols, which are known to act as adhesives for grafting functional molecules onto solid substrates. Fucoidan catechol (FD-C) is subsequently utilized for robust fucoidan coatings of solid substrates, and the FD-C-coated surfaces show excellent antifouling capability for fouling organisms, including platelets and bacteria. The FD-C coating is also confirmed to be nonirritating upon skin contact, demonstrating its potential use in public places for inhibiting contagions.

In this paper, we propose frequency allocation and path selection scheme in underlay cognitive radio (CR) networks using network coding. In the proposed scheme, we choose the path with consideration of network coding and interference temperature in underlay CR networks and propose an optimization problem to maximize the system throughput of secondary users (SUs). Then, we represent the proposed optimization problem as the multi-dimensional multiple-choice knapsack problem and give the theoretical upper bound for the system throughput of SUs by using linear programming. Finally, we compute the system throughput of SUs by using brute-force search (BFS) and link quality first (LQF) scheme in underlay CR networks. Simulation results show that the system throughput of SUs with BFS is higher than that with LQF in underlay CR networks with and without application of network coding, respectively.

The advanced technologies available for micro/nanofabrication have opened new avenues for interdisciplinary approaches to solve the unmet medical needs of regenerative medicine and biomedical devices. This review highlights the recent developments in micro/nanostructured adhesives and films for biomedical applications, including waterproof seals for wounds or surgery sites, drug delivery, sensing human body signals, and optical imaging of human tissues. We describe in detail the fabrication processes required to prepare the adhesives and films, such as tape-based adhesives, nanofilms, and flexible and stretchable film-based electronic devices. We also discuss their biomedical functions, performance in vitro and in vivo, and the future research needed to improve the current systems.

본 연구는 미세유체 장치를 통해 제조가 이루어진 펙틴 하이드로겔 입자의 수거 방법을 다르게 하였을 때 각 방법에따른 하이드로겔의 물리적 특성을 비교한 것이다. 펙틴 하이드로겔 입자는 미세유체 채널 내에서 미네랄 오일에 분산된 칼슘 이온에 의해 겔화되고 이후 각각 파이펫팅법, 튜브법, 침전법을 통해 수거하였다. 각 방법으로 수거된 펙틴 하이드로겔 입자의 단분산성을 분석한 결과 침전법의 변동 계수(Coefficient of variation)는 3.46으로 파이펫팅법(18.60)과 튜브법(14.76)의 변동 계수보다 월등히 낮아 가장 우수한 단분산성 하이드로겔 입자를 만들 수 있었다. 상기 침전법을 이용한 조건에서 분산상과 연속상의 부피유속 및 펙틴 용액의 점도를 조절함으로써 30 μm에서 180 μm까지의 다양한 크기를 갖는 단분산성 펙틴 하이드로겔을 제조할 수 있었다. 본 논문에서 제시한 펙틴 하이드로겔 입자는 생체 물질을 손쉽게 함입할 수 있으므로 이는 향후 약물전달, 식품, 그리고 생체적합성 재료 등으로 활용 가능할 것으로 기대된다.

Large-scale petrochemical and power plants has increased demanting wireless technology for continuous monitoring. However, the current USN technologies, such as ZigBee and Bluetooth, are lackof reliability and security. Therefore, there is a strong need to apply a new wireless technology standard of the ISA. In this study, a petrochemicalplant safety management system based on the ISA wireless transmitter isdeveloped. ISA100.11a communication module and LTE communication module equippedwith an explosion-proof wireless transmitter are developed. A petrochemicalplant safety management system is built based on the IoT technologies. Thedeveloped system is verified through a wide range of testing and thus, on-siteapplicability is proved.

Renal tubular acidosis (RTA) refers to a group of disorders involving transport defects in bicarbonate reabsorption or hydrogen excretion. Features like metabolic acidosis with a normal anion gap, neurological symptoms, and electrolyte imbalances indicate RTA. Kidney transplantation, cirrhosis, sickle cell anemia, medications, and autoimmune diseases, particularly Sjogren’s syndrome and rheumatoid arthritis, are related to RTA. We encountered a rare case of a patient with systemic lupus erythematosus accompanied by RTA secondary to tacrolimus administration, who had muscle weakness and paralysis. Her symptoms improved after discontinuing tacrolimus and correcting the acidosis and potassium levels. Here, we report on this case and review the relevant literature. (Korean J Med 2015;89:478-481)

Despite scientific progress in the study of Alzheimer's disease (AD), it is still challenging to develop a robust and sensitive methodology for the early diagnosis of AD due to the lack of a decisive biomarker in blood. Recent reports on the oligomer amyloid β (Aβ) as a biomarker demonstrated its possibility for identifying early onset of AD in patients, but its low concentration in blood requires highly reliable detection techniques. To overcome the low reliability and labor-intensive procedures of conventional enzyme-linked immunosorbent assay (ELISA), we present a magnetic bead-droplet immunoassay platform for simple and highly sensitive detection of oligomer Aβ for the diagnosis of AD. This microchip consists of chambers that contain water-based reagents or oil for consecutive assay procedures, and there are arrays of micro-pillars fabricated between the two adjacent chambers to form robust water-oil interfaces. With the aid of these micro-pillars, magnetic beads can stably pass through each chamber by linearly actuating a magnet along the microchip. The robust water-oil interface and simple procedures of the assay make it possible to obtain reliable results from this microchip. The intensity of the fluorescence at the read-out chamber increased quantitatively and linearly, depending on the amount of serially-diluted standard Aβ solution. The results of the assay indicated that the limit of detection was about 10 pg/mL even though it was done with manual manipulation of the magnet. This platform simplified the complicated ELISA procedure and achieved high sensitivity that was no lower than that of the conventional magnetic bead immunoassay. The magnetic bead-droplet platform reduced the assay time to 45 min, and it also reduced the amount of antibody usage in a single diagnosis significantly (10-30 ng of antibody per single assay). Consequently, this microfluidic chip has strong potential as a feasible system for use in the diagnosis of AD with a fast and easy immunoassay process, since the suggested platform can be automated with ease for point-of-care testing as well as high-throughput diagnostic equipment.

The design and development of fluorescent chemosensors have recently been the focus of considerable attention for the sensitive and specific detection of environmentally and biologically relevant metal ions in aqueous solutions and in living cells. Herein, we report photophysical results for a 1 H -pyrrole-2-carboxaldehyde-substituted rhodamine 6G derivative (RCS) that possesses specific binding affinity toward Al 3+ and Cu 2+ at micromolar concentration levels. In an N , N -dimethylformamide (DMF) and water (v/v = 2/8) medium, the RCS chemosensor exhibits a substantially enhanced absorbance intensity at 532 nm and a color change from colorless to pink for Cu 2+ ; it also exhibits significant “off–on” fluorescence at 557 nm, accompanied by a color change from colorless to fluorescent-yellow upon binding to Al 3+ . The RCS sensor exhibits extremely high fluorescence enhancement upon complexation with Al 3+ , and it can be used as a “naked eye” sensor. Through fluorescence titration at 557 nm, we confirmed that RCS exhibits a fluorescence response with a remarkable enhancement in emission intensity resulting from the complexation between RCS and Al 3+ , whereas no emission appeared in the case of competitive metal ions (Cu 2+ , Al 3+ , Li + , Na + , K + , Cs + , Mg 2+ , Ca 2+ , Fe 2+ , Co 2+ , Ag + , Zn 2+ , Cd 2+ , Hg 2+ and Pb 2+ ) in a DMF and water (v/v = 2/8) solution. The reversible ring-opening mechanism of the rhodamine spirolactam induced by Al 3+ /Cu 2+ binding and the 1:1 stoichiometric structure between RCS and Al 3+ were adequately supported by Job-plot evaluation, optical titration and FT-IR analysis. The lowest detection limit for Al 3+ is 3.20 × 10 6 M −1 in a DMF and water (v/v = 2/8) solution. Al 3+ -induced chelation-enhanced fluorescence (CHEF) is associated with spirolactam ring opening of the rhodamine unit. Finally, RCS was successfully applied for the bio-imaging of Al 3+ in living HeLa cells and for fluorescence imaging of a microfluidic system.

We report a perfluoroaryl azide-based photoreaction for synthesizing functionalizable and nonbiofouling poly[oligo(ethylene glycol) methacrylate] (pOEGMA) films on a chemically inert COC substrate, and an estimation of a surface coverage of the antibody immobilized onto the surface with the immuno-gold nanoparticles. The processes were confirmed by water contact angle measurement, FT-IR spectroscopy, and FE-SEM. The strategy demonstrated in this work could be applied to functionalizations of other polymeric materials and determination of the binding capacity of analytes in biosensors and microfluidic devices.

We report a facile method for surface-initiated ring opening polymerization (ROP) and atom transfer radical polymerization (ATRP) via a poly(norepinephrine) coating. Solid substrates were modified by poly(norepinephrine) under alkaline conditions, with concurrent co-adsorption of an ATRP initiator. The poly(norepinephrine) layer acted as a ROP initiator due to the presence of hydroxyl groups in its side chain, resulting in a surface that was able to initiate ATRP and ROP simultaneously. ε-Caprolactone (ε-CL) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) were grafted onto the surface via ROP and ATRP, respectively, and the polymers subsequently grown from the surfaces were characterized in detail using Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), contact angle goniometry, and atomic force microscopy (AFM).

The three-dimensional (3D) clustering of Janus cylinders is controlled by simply tuning the cylinder geometry and hydrophobic interactions. Janus cylinders were prepared by combining two approaches: micromolding and initiated chemical vapor deposition (iCVD). Hydrophilic cylinders with a flat- or convex-top curvature were prepared by micromolding based on surface tension-induced flow. The iCVD process then provides a hydrophobic domain through the simple and precise deposition of a polymer film on the top surface, forming monodisperse Janus microcylinders. We use these Janus cylinders as building blocks to form 2D or 3D clusters via hydrophobic interactions in methanol. We investigate how cylinder geometry or degree of hydrophobic interaction affects the resulting cluster geometries. The convex-top Janus cylinders lead to 3D clustering through tip-to-tip interactions, and the flat-top Janus cylinders lead to 2D clustering through face-to-face attraction. The number of Janus cylinders in 3D clusters is tuned by controlling the degree of hydrophobic (or hydrophilic) interaction.

In the present study, we successfully synthesized a porous three-dimensional Prussian blue-cellulose aerogel (PB-CA) composite and used it as a decorporation agent for the selective removal of ingested cesium ions (Cs+) from the gastrointestinal (GI) tract. The safety of the PB-CA composite was evaluated through an in vitro cytotoxicity study using macrophage-like THP-1 cells and Caco-2 intestinal epithelial cells. The results revealed that the PB-CA composite was not cytotoxic. An adsorption study to examine the efficiency of the decorporation agent was conducted using a simulated intestinal fluid (SIF). The adsorption isotherm was fitted to the Langmuir model with a maximum Cs+ adsorption capacity of 13.70 mg/g in SIF that followed pseudo-second-order kinetics. The PB-CA composite showed excellent stability in SIF with a maximum Cs+ removal efficiency of 99.43%. The promising safety toxicology profile, remarkable Cs+ adsorption efficacy, and excellent stability of the composite demonstrated its great potential for use as an orally administered drug for the decorporation of Cs+ from the GI tract.

We report an effective and versatile approach to control marine fouling on artificial surfaces based on specific chemical interactions found in marine mussels. The approach consists of mussel-inspired polydopamine coating, spin-coating-assisted deposition of poly(ethylene glycol) (PEG) catechols, and their cross-linking via catechol–Fe3+–catechol interactions. Using this approach, multilayered PEG films that were highly resistant to marine diatom adhesion were successfully constructed on various substrates, such as stainless steel, nylon, titanium oxide, and silicon oxide. We believe that our results will provide a basis for the construction of a marine antifouling agent that can be applied by a large variety of industries owing to its applicability to different types of substrates and stability under marine environments.

The surface coating of solid substrates using dextrans has gained a great deal of attention, because dextran-coated surfaces show excellent anti-fouling property as well as biocompatibility behavior. Much effort has been made to develop efficient methods for grafting dextrans on solid surfaces. This led to the development of catechol-conjugated dextrans (Dex-C) which can adhere to a number of solid surfaces, inspired by the underwater adhesion behavior of marine mussels. The present study is a systematic investigation of the characteristics of surface coatings developed with Dex-C. Various Dex-C with different catechol contents were synthesized and used as a surface coating material. The effect of catechol content on surface coating and antiplatelet performance was investigated.

Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis, which triggers severe pulmonary diseases. Recently, multidrug/extensively drug-resistant tuberculosis strains have emerged and continue to threaten global health. Because of the development of drug-resistant tuberculosis, there is an urgent need for novel antibiotics to treat these drug-resistant bacteria. In light of the clinical importance of M. tuberculosis, 2067 structures of M. tuberculsosis proteins have been determined. Among them, 52 structures have been solved and studied using solution nuclear magnetic resonance (NMR). The functional details based on structural analysis of M. tuberculosis using NMR can provide essential biochemical data for the development of novel antibiotic drugs. In this review, we introduce diverse structural and biochemical studies on M. tuberculosis proteins determined using NMR spectroscopy.

Curry stains on clothes and dishes in daily life inspired us to investigate the potential use of turmeric powder, the major ingredient in curry, as a universal coating material. After condition optimization, the coating solution was made by boiling and filtering a turmeric slurry, and the coating was formed at pH 3, leading to the formation of ultrathin, transparent films. Various inorganic and polymeric substrates were successfully coated with turmeric-based materials, including gold, TiO2, SiO2, glass, stainless steel, indium tin oxide, nylon, polyethylene, polycarbonate, polypropylene, acryl, and poly(ethylene terephthalate). The turmeric-based coating was also applied to poly(tetrafluoroethylene) (PTFE, Teflon) and cyclic olefin copolymer (COC), and after double dip-coating, the water contact angle was changed from 118.2° to 49.1° for PTFE and from 91.2° to 44.7° for COC. The water contact angles for the other substrates converged to 35° after coating, confirming the substrate-independent universal co...

Toxin-antitoxin (TA) systems are essential for bacterial persistence under stressful conditions. In particular, Mycobacterium tuberculosis express VapBC TA genes that encode the stable VapC toxin and the labile VapB antitoxin. Under normal conditions, these proteins interact to form a non-toxic TA complex, but the toxin is activated by release from the antitoxin in response to unfavorable conditions. Here, we present the crystal structure of the M. tuberculosis VapBC26 complex and show that the VapC26 toxin contains a pilus retraction protein (PilT) N-terminal (PIN) domain that is essential for ribonuclease activity and that, the VapB26 antitoxin folds into a ribbon-helix-helix DNA-binding motif at the N-terminus. The active site of VapC26 is sterically blocked by the flexible C-terminal region of VapB26. The C-terminal region of free VapB26 adopts an unfolded conformation but forms a helix upon binding to VapC26. The results of RNase activity assays show that Mg2+ and Mn2+ are essential for the ribonuclease activity of VapC26. As shown in the nuclear magnetic resonance spectra, several residues of VapB26 participate in the specific binding to the promoter region of the VapBC26 operon. In addition, toxin-mimicking peptides were designed that inhibit TA complex formation and thereby increase toxin activity, providing a novel approach to the development of new antibiotics.

Herein we demonstrate a systematic investigation of chemically functionalizable, non-biofouling agarose films over large-area glass surfaces. Agarose films, prepared with various concentrations of aqueous agarose, were activated by using periodate oxidation to generate aldehyde groups at the termini of the agarose chains. The non-biofouling efficacy and binding capabilities of the activated films were evaluated by using protein and cellular patterning, performed by using a microarrayer, microcontact printing, and micromolding in capillaries. Characterization by using a fluorescence slide scanner and a scanning-probe microscope revealed that the pore sizes of the agarose films played an important role in achieving desirable film performance; the 0.2 wt % agarose film exhibited the optimum efficacy in this work.

본 연구의 목적은 우리나라 중고령자 자산빈곤층의 특성을 이해하고 이 계층의 자산빈곤이행에 영향을 미치는 요인을 이해하는 것이다. 이러한 연구목적을 위해 본 연구에서는 고령화연구패널조사의 1차~4차년도 자료를 활용하여 자산빈곤선을 절대적 자산빈곤선(유동자산이 최저생계비 3개월 이하)과 상대적 자산빈곤선(중위순자산의 50%)으로 설정하고 중고령자 특성 중 어떤 요인이 자산빈곤이행에 영향을 미치는지를 이항 및 다항로짓분석을 실시하여 분석하였다. 본 연구를 통해 얻은 결과와 연구결과로부터 도출한 정책적 제언은 다음과 같다. 첫째, 다항로짓분석 결과 자가 보유, 고소득, 건강상태양호, 독신가구, 대도시권, 아파트 거주자, 비경활, 자영업일 경우에 계속자산빈곤층일 가능성이 낮은 것으로 나타났다. 이는 중고령층을 위한 제도 설계시 상용직의 안정적인 고용제공 보다는 건강관리 지원정책 등이 더 의미 있을 것으로 판단된다. 둘째, 상대적자산빈곤의 기준인 순자산의 비중을 차지하는 중요한 요인인 주택, 토지 등의 부동산은 소득과 비교하여 빠른 시간 내에 축적하기 어렵다는 점을 감안하여 청장년기부터 중장기적으로 자산 형성을 할 수 있는 정책적 지원이 필요하다. 셋째, 중고령자의 재취업, 창업을 위한 직업 교육 및 건강관리 등 중고령자에 특화된 정책적 지원이 필요하다. 마지막으로 한국 사회에서 자산 형성을 지원하는 정책에는 안정적인 주거 환경으로 이전 할 수 있는 기회를 제공하는 노력이 포함되어야 할 것이다.

This study presents a micromolding for the synthesis of Janus particles with reconfigurable shape by pH stimuli. First, we use acrylic acid (AA) as pH responsive monomer in the hydrophilic part and trimethylolpropane triacylate (TMPTA) in the hydrophobic part, respectively. The change of acidity in solvent induces the swelling of hydrophilic part in the Janus particles. The pH-responsive Janus particles show different swelling ratio of hydrophilic part in according to composition of acrylic acid in diverse range (0-70% v/v) and pH (3-11). As the concentration of acrylic acid in the hydrophilic part and environmental pH increase, the hydrophilic part in the Janus particles is proportionally swelled. Second, we fabricate novel type of Janus particles with two different hydrophilicities. As a proof of concept, we have applied acrylic acid (AA) and 2-(dimethylamino)ethyl methacrylate (DAEMA) into each part because the monomers provide reverse responsive activity. As expected, these Janus particles show different shape anisotropies with reconfigurable property in accordance with the polarity of each part at same acidity of environ- mental solvent. We envision that the stimuli responsive Janus particles have a wide application from fundamental science to diagnostic apparatus.

Polydopamine (pDA), a mussel-inspired polymer, has been extensively utilized in various areas because of its versatile and multifunctional properties. However, the poor chemical stability of pDA under harsh reaction conditions has hampered its wider applicability, and therefore, enhancement of its chemical stability is required. In this study, we report a facile method for enhancing the chemical stability of pDA layers. The simple immersion of pDA-coated substrates in an iron chloride solution resulted in the production of pDA layers complexed with Fe III , and these layers showed highly enhanced stability even in the presence of a strong alkali (1 M NaOH).

Lung cancer, which can be divided into two major clinical–pathological categories, small cell lung cancer and non-small cell lung cancer, is the leading cause of cancer-related death worldwide. MicroRNAs (miRNAs), small non-coding RNAs approximately 22 nucleotides in length, have been reported to be upregulated or downregulated in disease states and specific cell types. Recently, miRNAs have gained recognition as major regulators of human gene expression. MiRNAs can control highly complex signal transduction pathways and other biological pathways by targeting and controlling gene expression, accounting for their important role in lung cancer. Findings from recent studies on the roles of miRNAs in lung cancer are summarized in this review. Understanding miRNA functions in lung cancer will bring molecular-level insight leading to better prognosis, diagnosis, and therapeutic approaches.

We present a facile and inexpensive approach without any fluorinated chemistry to create superhydrophobic surface with exceptional liquid repellency, transportation of oil, selective capture of oil, optical bar code, and self-cleaning. Here we show experimentally that the control of evaporation is important and can be used to form superhydrophobic surface driven by Marangoni instability: the method involves in-situ photopolymerization in the presence of a volatile solvent and porous PDMS cover to afford superhydrophobic surfaces with the desired combination of micro- and nanoscale roughness. The porous PDMS cover significantly affects Marangoni convection of coating fluid, inducing composition gradients at the same time. In addition, the change of concentration of ethanol is able to produce versatile surfaces from hydrophilic to superhydrophobic and as a consequence to determine contact angles as well as roughness factors. In conclusion, the control of evaporation under the polymerization provides a convenient parameter to fabricate the superhydrophobic surface, without application of fluorinated chemistry and the elegant nanofabrication technique.

Controllable generation of complex emulsions comprising exceptional features such as several compartments and shape anisotropy is becoming increasingly important. Complex emulsions are attracting great interest due to their significant potential in many applications, including foods, pharmaceuticals, cosmetics, materials, and chemical separations. Microfluidics is emerging as a promising route to the generation of complex emulsions, providing precise control over emulsion shape, size, and compartments. The aim of this Minireview is to mainly describe the progress of microfluidic approaches to design complex emulsions using hydrodynamic control and phase separation. The emulsions formed are classified according to their morphology, anisotropy, and internal structure. Emerging applications of complex emulsions formed using these microfluidic techniques are discussed.

FolC plays important roles in the folate metabolism of cells by attaching l-Glu to dihydropteroate (DHP) and folate, which are known activities of dihydrofolate synthetase (DHFS) and folylpolyglutamate synthetase (FPGS), respectively. Here, we determined the crystal structure of Helicobacter pylori FolC (HpFolC) at 1.95 &Aring, resolution using the single-wavelength anomalous diffraction method. HpFolC has globular N- and C-terminal domains connected by a single loop, and a binding site for ATP is located between the two domains. Apo-HpFolC was crystallized in the presence of citrate in a crystallization solution, which was held in the ATP-binding site. Structural motifs such as the P-loop and &Omega, loop of HpFolC for binding of ATP and two magnesium ions are well conserved in spite of the low overall sequence similarity to other FolC/FPGSs. The &Omega, loop would also recognize a folate molecule, and the DHP-binding loop of HpFolC is expected to exhibit a unique recognition mode on DHP, compared with other FolCs. Because human FolC is known to only exhibit FPGS activity, the DHFS activity of bacterial FolC is an attractive target for the eradication of pathogenic bacteria. Consequently, our structural analyses of HpFolC provide a valuable foundation for a universal antibacterial strategy against H. pylori as well as other pathogenic bacteria.