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The impact of the Olympics has long been under question as cities have been left in an inescapable detriment to their economy and environment while others experienced an overall profit. Therefore, it is important to analyze how some cities were so successful in hosting the Olympics while others were left with a giant bill that still holds an impact on them today. To maximize the true effects the Olympics can hold onto a city’s production of infrastructure while minimizing the debt they are left with, it is important to reflect on cities that have hosted the Olympics in the past. The objective of this paper is to analyze factors such as infrastructure, environment, economy, etc. to conclude the true overall impact an Olympic Series could cause on a host city. The findings of this paper are intended to help perceive the true effective procedures to profit the most from hosting the Olympic Games, while also being a catalyst to what could be altered in the process to make the process as cost-efficient and effective as possible. Keywords: Olympics; Olympic Games; environment; host city; economy; infrastructure. Title: Olympic Structures and their Effect on the Host City’s Environment, Economy, and Infrastructure Author: Junoh Kim International Journal of Civil and Structural Engineering Research ISSN 2348-7607 (Online) Vol. 11, Issue 1, April 2023 - September 2023 Page No: 52-61 Research Publish Journals Website: www.researchpublish.com Published Date: 22-May-2023 DOI: https://doi.org/10.5281/zenodo.7961040 Paper Download Link (Source) https://www.researchpublish.com/papers/olympic-structures-and-their-effect-on-the-host-citys-environment-economy-and-infrastructure, International Journal of Civil and Structural Engineering Research, ISSN 2348-7607 (Online), Research Publish Journals, Website: www.researchpublish.com

Natural products and their derivatives historically represent alternatives to conventional synthetic molecules for pharmacotherapy, ranging from cancer chemotherapeutics to cosmetic ingredients that exert anti-aging activities. Cellular senescence is considered a main driver of skin aging, yet natural products that target skin senescence in a specific manner are not thoroughly explored. Here, we performed a focused compound screen to identify natural products that exert anti-senescence effects. We found that

In this paper, we propose an advanced double layered multi-agent system to reduce learning time, expressing a state space using a 2D grid. This system is based on asynchronous advantage actor-critic systems (A3C) and reduces the state space that agents need to consider by hierarchically expressing a 2D grid space and determining actions. Specifically, the state space is expressed in the upper and lower layers. Based on the learning results using A3C in the lower layer, the upper layer makes decisions without additional learning, and accordingly, the total learning time can be reduced. Our method was verified experimentally using a virtual autonomous surface vehicle simulator. It reduced the learning time required to reach a 90% goal achievement rate by 7.1% compared to the conventional double layered A3C. In addition, the goal achievement by the proposed method was 18.86% higher than that of the traditional double layered A3C over 20,000 learning episodes.

Several studies have reported that a drug nanocarrier conjugated with ligands having cell binding ability improves drug delivery performance, but multiple cell-targeting and the resultant activation in designated cells has not been investigated yet. This study reports a skin cell multi-targeting vesicular nanocargo system. We selectively conjugated several skin protein-derived cell-targeting peptides (CTPs), including KTTKS, NAP-amide, and Lam332, to amphiphilic polymer-reinforced lipid nanovesicles (PLNVs) to specifically target fibroblasts, melanocytes, and keratinocytes, respectively, through effective association with the corresponding cell membrane receptors. We then showed that CTP-conjugated PLNVs specifically bind to the designated skin cells, even in a mixture of different types of skin cells, eventually leading to skin cell multi-targeting and consequent activation. These results highlight that this CTP-conjugated PLNV system has significant potential for developing an intelligent cellular drug delivery technology for dermatological applications.

Vertically aligned two-dimensional (2D) molybdenum disulfide nanoflowers (MoS

Senescent fibroblasts progressively deteriorate the functional properties of skin tissue. Senescent cells secrete senescence-associated secretory phenotype (SASP) factor, which causes the aging of surrounding non-senescent cells and accelerates aging in the individuals. Recent findings suggested the senomorphic targeting of the SASP regulation as a new generation of effective therapeutics. We investigated whether Isatis tinctoria L. leaf extract (ITE) inhibited senescence biomarkers p53, p21CDKN1A, and p16INK4A gene expression, and SASP secretions by inhibiting cellular senescence in the replicative senescent human dermal fibroblast (RS-HDF). ITE has been demonstrated to inhibit the secretion of SASP factors in several senomorphic types by regulating the MAPK/NF-κB pathway via its inhibitory effect on mTOR. ITE suppressed the inflammatory response by inhibiting mTOR, MAPK, and IκBα phosphorylation, and blocking the nuclear translocation of NF-κB. In addition, we observed that autophagy pathway was related to inhibitory effect of ITE on cellular senescence. From these results, we concluded that ITE can prevent and restore senescence by blocking the activation and secretion of senescence-related factors generated from RS-HDFs through mTOR-NF-κB regulation.

In this paper, a liquid lenticular lens with correct focal length was designed by controlling the width of the electrode and analyzing the microfluidic phenomena at boundary between oil and salted water in the liquid lenticular lens. A liquid lenticular lens that has inaccurate focal length results in serious crosstalk and three-dimensional (3-D) image distortion. Therefore, to reduce the crosstalk, the liquid lenticular lens should be fabricated in such a way that the image plane of the LCD is at the focal plane of the lens. To do so, the width of the electrode was adjusted and saturation angle between two liquids and the sidewall of the chamber was measured. The optimum width of the electrode was derived by applying the saturation angle and a final sample having a short focal length was fabricated. When the width of the electrode was optimized, the crosstalk was measured at 21.95% and the value was 10% less than when not being optimized. Also, the viewing angle was increased up to 45°. As a result, this crosstalk reduction led to 3-D image enhancement.

This letter deals with a 2D and 3D convertible device implemented using a liquid lens. The electro-wetting on dielectric (EWOD) phenomenon was used to operate the liquid lens. The research aimed to display 3D images clearly by achieving the highest dioptric power. The 2D state and the 3D state were switched by a meniscus of two immiscible liquids, and concave to convex lens states were formed by the meniscus. In a previous iteration, during EWOD operation, the oil phase moved in unexpected directions. This movement degraded the total quality of the lenticular system when displaying the 3D state. Here, a method is suggested to avoid the phenomenon by controlling the area of the electrode. Since the dioptric power of the lens is determined by the contact angle of the oil and the water, the electrode location, which determines the volume of the oil phase, was investigated to obtain the maximum dioptric power range. The two liquids were dosed into transparent chambers where the dielectric layer and the electrode were deposited. Finally, the highest diopter was achieved, which showed improved 3D image quality.

Focus-tunable liquid lens arrays have been used to improve depth in glass-free three-dimensional devices where high fill factor is required. For high fill factors, polygonal apertures should be used, but due to the difficulty of controlling aberrations during focus tuning, polygonal aperture focus-tunable lenses have rarely been studied. This Letter proposes a new structure with walls at the lens boundaries using a square parabolic lens model to control the quadrafoil aberration induced by the square aperture. ANSYS simulation confirmed that the lens surface was closest to the parabolic lens model when the wall thickness was 1.4 mm. A fabricated lens array demonstrated the quadrafoil inhibitory effect and confirmed the utility of the new structure.

In this paper, we introduce a method for improving the lens diopter of 2D/3D convertible devices using electro-wetting. For stable operation, an electro-wetting device requires high dioptric performance and this was achieved using bi-convex liquid-liquid-solid phases. 1-Chloronaphthalene with a refractive index of 1.633 was used as an oil phase to achieve high diopters. ETPTA (trimethylolpropane ethoxylate triacrylate), a UV-sensitive material with low chemical reactivity to the 1-Chloronaphthalene, was used as a chamber material. This resulted in a diopter of 3030D for high quality multi-view images without unstable oil movement or trembling. The ETPTA was molded on a 0.3mm thick glass substrate that was coated with UV adhesive (NOA 81). The maximum diopter capable of stable operation was 3425D. 2D and 3D conversion and parallax motion were demonstrated.

Recently, a planoconvex structure electrowetting lenticular lens capable of 2D/3D conversion through a varifocal property by an electrowetting phenomenon has been developed. However, even though it has a similar planoconvex structure to that of a commercial solid lenticular lens, comparable 3D performance could not be realized because the refractive index difference between nonconductive liquid and conductive liquid was not large. Therefore, the goal of the present study is to obtain better 3D performance compared to the conventional planoconvex structure by introducing a novel biconvex structure using ETPTA. The newly developed biconvex structure electrowetting lenticular lens showed greatly improved characteristics compared to the planoconvex structure: dioptric power (171.69D → 1,982.56D), viewing angle (26degrees → 46degrees), and crosstalk ratio (27.27% → 16.18%). Thanks to these improvements, a fine 3D image and a natural motion parallax could be observed with the biconvex structure electrowetting lenticular lens. In addition, the novel biconvex structure electrowetting lenticular lens was designed to achieve a plane lens state with a no voltage applied condition, and as such it could show a clean 2D image at 0 V. In conclusion, a novel biconvex structure electrowetting lenticular lens showed 2D/3D switchable operation as well as excellent 3D performance compared to a solid lenticular lens.

In this paper, the drawbacks of the conventional electrowetting lenticular lens such as unstable operation, low dioptric power, high operating voltage, and low fill factor were resolved through a biconvex structure. In our previous study, there was only one interface between DI water and oil. However, an interface between ETPTA and oil was added to form a biconvex structure. The biconvex structure was fabricated by exploiting the phenomenon that the liquid ETPTA changes into a solid upon exposure to UV light. The amount of ETPTA was adjusted to control the curvature of the interface between the ETPTA and oil. Also, the volume of oil was controlled to realize zero dioptric power at 0V. The biconvex electrowetting lenticular lens has powerful optical properties, showing the highest dioptric power of 2000D with a 414.7um aperture diameter, and operating with a voltage 0-17V. The dioptric power was 0D at 0V, which means the shape of the lens is flat, and 2000D at 17V, which means the shape of the lens is sufficiently convex to view a 3D image. The viewing angle was measured as 46 degrees and the response time was measured as 0.83ms. Also, crosstalk of 16.18 % was measured. A 24- view image was tested by combining the fabricated 5-inch lenticular lens with a display (G Pro 2).

Liquid lenticular lens array can solve the disadvantages of currently available lenticular type three-dimensional (3D) display with solid lenses in that it enables 2D-3D conversion and has no complex calculations to fabricate. Liquid lenticular lens array needs a chamber which contains liquids and this chamber is usually made of a polymer-based plastic such as poly methyl methacrylate (PMMA) and poly carbonate (PC). However, oil acting as a lens permeates into these plastics because they are porous. For this reason, although the liquid lenticular lens array has many advantages, it is not easy to apply to 3D display system because of its short life time. In this paper, the liquid lenticular lens array with a new chamber using Pyrex glass is presented. A multilayer of metal, Cr/Au/Cr/Au, in combination with AZ2070 photoresist was used for wet etching of glass which was conducted in concentrated hydrofluoric acid (HF). The metal multilayer was deposited by using the thermal evaporator and serves as a mask for glass etching and another Cr/Au/Cr/Au multilayer was deposited on the opposite part of the glass. The Pyrex glass was etched at a rate of 7.5μm/s in 49% HF solution. With the completed Pyrex chamber, the liquid lenticular lens array was fabricated and operation tests were done. We also compared the new liquid lenticular lens array with the Pyrex glass chamber to one with the polymer-based plastic chamber in regard to reliability.

In this study, Polygonum aviculare L. extract, which has superior antioxidative and cellular membrane protective activity, was loaded onto cell penetrating peptide (CPP) conjugated liposomes to enhance transdermal delivery. The physical characteristics of typical liposomes and CPP-conjugated liposomes containing P. aviculare extract were evaluated. The particle sizes of both liposomes were approximately 150 nm. Whereas the zeta potential of typical liposomes was -45 mV, that of CPP-conjugated liposomes was +42 mV. The loading efficiency of P. aviculare extract in both liposomes was calculated to be about 83%. Fluorescent-labeled liposomes were prepared to evaluate cellular uptake and skin permeation efficiency. Using flow cytometry, we found that CPP-conjugated liposomes improved cellular uptake of the fluorescent dye as compared with the typical liposomes. In addition, the skin permeation of CPP-conjugated liposomes was proved higher than that of typical liposomes by confocal laser scanning microscopy studies and Franz diffusion cell experiments. The improved cellular uptake and skin permeation of the CPP-conjugated liposomes were due to the cationic arginine-rich peptide. In vivo studies also determined that the CPP-conjugated liposomes were more effective in depigmentation and anti-wrinkle studies than typical liposomes. These results indicate that the CPP-conjugated liposomes could be effective for transdermal drug delivery of antioxidant and anti-aging therapeutics.

Liquid lenticular multi-view system has great potential of three dimensional image realization. This paper aims to introduce a novel fabrication method of electro-wetting liquid lenticular lens using diffuser. The liquid lenticular device consists of a Ultraviolet (UV) adhesive chamber, two immiscible liquids and a sealing plate. The diffuser makes UV light spread slantly not directly to negative photoresist on a glass substrate. In this process, Su-8, the suitable material to fabricate a structure in high stature, is selected for negative photoresist. After forming a Su-8 chamber, the UV adhesive chamber is made through a PDMS sub-chamber that is made from the Su-8 chamber. As such, this research shows a result of a liquid lenticular lens having slanted side walls with an angle of 75 degrees. The UV adhesive chamber having slanted side walls is more advantageous for electro-wetting effect achieving high diopter than the chamber having vertical side walls. After that, gold is evaporated for electrode, and Parylene C and Teflon AF1600 is deposited for dielectric and hydrophobic layer respectively. For two immiscible liquids, DI water and a blend of 1-Chloronaphthalene and Dodecane with specific portions are used. Two immiscible liquids are injected in underwater environment and a glass that is coated with ITO on one side is sealed by UV adhesive. The completed tunable lenticular lens can switch two and three dimensional images by using electro-wetting principle that changes surface tensions by applying voltage. Also, dioptric power and response time of the liquid lenticular lens array are measured.

Lenticular type multi-view display is one of the most popular ways for implementing three dimensional display. This method has a simple structure and exhibits a high luminance. However, fabricating the lenticular lens is difficult because it requires optically complex calculations. 2D-3D conversion is also impossible due to the fixed shape of the lenticular lens. Electrowetting based liquid lenticular lens has a simple fabrication process compared to the solid lenticular lens and the focal length of the liquid lenticular lens can be changed by applying the voltage. 3D and 2D images can be observed with a convex and a flat lens state respectively. Despite these advantages, the electrowetting based liquid lenticular lens demands high driving voltage and low breakdown voltage with a single dielectric layer structure. A certain degree of thickness of the dielectric layer is essential for a uniform operation and a low degradation over time. This paper presents multilayer dielectric structure which results in low driving voltage and the enhanced dielectric breakdown. Aluminum oxide (Al2O3), silicon oxide (SiO2) and parylene C were selected as the multilayer insulators. The total thickness of the dielectric layer of all samples was the same. This method using the multilayer dielectric structure can achieve the lower operating voltage than when using the single dielectric layer. We compared the liquid lenticular lens with three kinds of the multilayer dielectric structure to one with the parylene C single dielectric layer in regard to operational characteristics such as the driving voltage and the dielectric breakdown.

These days micro lens array is used in various fields such as fiber coupling, laser collimation, imaging and sensor system and beam homogenizer, etc. One of important thing in using micro lens array is, choice of its pitch. Especially imaging systems like integral imaging or light-field camera, pitch of micro lens array defines the system property and thus it could limit the variability of the system. There are already researches about lens array using liquid, and droplet control by electrowetting. This paper reports the result of combining them, the liquid lens array that could vary its pitch by electrowetting. Since lens array is a repeated system, realization of a small part of lens array is enough to show its property. The lens array is composed of nine (3 by 3) liquid droplets on flat surface. On substrate, 11 line electrodes are patterned along vertical and horizontal direction respectively. The width of line electrodes is 300um and interval is 200um. Each droplet is positioned to contain three electrode lines for both of vertical and horizontal direction. So there is one remaining electrode line in each of outermost side for both direction. In original state the voltage is applied to inner electrodes. When voltage of outermost electrodes are turned on, eight outermost droplets move to outer side, thereby increasing pitch of lens array. The original pitch was 1.5mm and it increased to 2.5mm after electrodes of voltage applied is changed.

This study introduces a 3D lenticular system and its fabrication method operating with liquids. The lenses of the lenticular system consists of two immiscible liquids requiring a good uniformity of their amount. The amount is controlled by an opened structures fabricated by silicon KOH etching process. For the fabrication, a low pressure silicon nitride (LSN) is deposited on a bare silicon wafer followed by a photolithography and a reactive ion etching (RIE) remaining a 200nm LSN layer. A KOH etching process is done for 2 hours with a KOH solution of 40wt% in deionized water. To fabricate the opened structure, a time controlling is required not to be fully etched. The finalized silicon wafer is sputtered by a copper layer as a seed layer for an electroplating. By the electroplating with nickel, a master mold is made. To get the high transparency, poly methyl methacrylate (PMMA) is chosen for the substrate and a hot embossing process is done by fabricated nickel mold with PMMA. The PMMA is coated by gold as an electrode and parylene C and Teflon multi-layer as dielectric layers. For two immiscible liquids, deionized water and a mixture of dodecane and 1-Chloronaphthalene are used. The dosing process is done in underwater environment and the mixed oil is dosed uniformly as the oil has tendency to spread onto the substrate. After sealing the active liquid lenticular devices is fabricated and good uniformity is achieved.

In this paper, we analyze the crosstalk of the liquid lenticular lens array and reduce the crosstalk by blocking light leakages from the top and wall parts of the chamber. A variety of factors affecting the crosstalk of the liquid lenticular lens array are proposed. The ratio of the unnecessary light from the top and wall parts of the chamber are theoretically calculated and compared with the measured values. By using laminating foil and increasing the thickness of the electrode layer compared to the conventional sample, the light leakages from the top and wall parts of the chamber are blocked, and thus, the crosstalk is reduced to 21.23%, which is similar to that of the solid lenticular lens array. Image tests were conducted to demonstrate that crosstalk is reduced using a new sample.

This study introduces a useful approach for fabrication of hollow-structured hydrogel microparticles and for encapsulation of biomacromolecules in the hollow core of the particles. Monodisperse hollow-structured poly(vinyl amine) hydrogel particles were fabricated without using templates that combines the dispersion polymerization and the sequential hydrolysis/crosslinking. The hydrogel shell showed pH-dependent mesh sizes; ∼2 nm at a normal condition (pH 3–12) and ∼11 nm at an expanded condition (pH 2). By taking advantage of pH-responsive mesh property, we demonstrated that dextran macromolecules, whose hydrodynamic radius is between the mesh sizes of the normal and expanded pH conditions, could be encapsulated and stored inside of the shell. Moreover, our hydrogel particles showed strong adhesion to human cells. Some of them were even engulfed by the cell membrane and drawn into the cell even with no aid of site-specific moieties. From these results, it is expected that the hydrogel hollow microcapsules synthesized in this study could be used for delivery of macromolecules into the cells.

Lenticular multi-view system has great potential of three dimensional image realization. This paper introduces a fabrication of liquid lenticular lens array and an idea of increasing view points with a same resolution. Tunable liquid lens array can produce three dimensional images by using electro-wetting principle that changes surface tensions by applying voltage. The liquid lenticular device consists of a chamber, two different liquids and a sealing plate. To fabricate the chamber, an silicon wafer is wet-etched by KOH solution and a trapezoid shaped chamber can be made after a certain time. The chamber having slanted walls is advantageous for electro-wetting achieving high diopter. Electroplating is done to make a nikel mold and poly methyl methacrylate (PMMA) chamber is fabricated through an embossing process. Indium tin oxide (ITO) is sputtered and parylene C and Teflon AF1600 is deposited for dielectric and hydrophobic layer respectively. Two immiscible liquids are injected and a glass plate as a sealing plate is covered with polycarbonates (PC) gaskets and sealed by UV adhesive. Two immiscible liquids are D.I water and a mixture of 1-chloronaphthalene and dodecane. The completed lenticular lens shows 2D and 3D images by applying certain voltages. Dioptric power and operation speed of the lenticular lens array are measured. A novel idea that an increment of viewpoints by electrode separation process is also proposed. The left and right electrodes of lenticular lens can be induced by different voltages and resulted in tilted optical axis. By switching the optical axis quickly, two times of view-points can be achieved with a same pixel resolution.

Liquid-filled square lens array has been developed for an alternative to solid lens array because of its advantage in variable focus length. In addition, the square lens array has advantage with high fill factor compared to liquid circular lens array which is another alternative. However, one of the main limitations of conventional square lens array is the distortion. In this paper, distortion-free liquid square lens array is proposed. The partition walls of the proposed square lens array is fabricated into hemispherical shape to reduce the distortion, and then additional vertical walls are set up on the hemispherical structures to unify the height of partition walls and divide chamber sections. UV lithography techniques are used to fabricate this structure, and diffuser which has an angle of 80 degrees is used in the process. Photoresist is exposed to scattered ultraviolet rays which pass through the diffuser, and hemispherical lens-shaped structures of photoresist remains after development process. Supplementary vertical partition walls are obtained by additional photoresist patterning process on the structure. In this structure, the interface between oil and water comes into contact with the surface of the hemispherical walls, and the refractive index of oil and the walls are equally matched to maximize the part which acts as lens in the chamber. The proposed liquid square lens array can provide us with aberration-free 3D images with high fill factor.

Conventionally, poly (dimethylsiloxane) lens array is fabricated by replica molding. In this paper, we describe simple method for fabricating lens array with expanding property of PDMS. The PDMS substrate is prepared by spin coating on cleaned glass. After spin coating PDMS, substrate is treated with O2 plasma to promote adhesion between PDMS substrate and photoresist pattern on it. Positive photoresist az-4330 and AZ 430K developer is used for patterning on PDMS. General photolithography process is used to patterning. Then patterned PDMS substrate is dipped to 1- Bromododecane bath. During this process, patterned photoresist work as a barrier and prevent blocked PDMS substrate from reaction with 1-Bromododecane. Unblocked part of PDMS directly react with 1-Bromododecane and results in expanded PDMS volume. The expansion of PDMS is depends on absorbed 1-Bromododecane volume, dipping time and ratio of block to open area. The focal length of lens array is controlled by those PDMS expansion factors. Scale of patterned photoresist determine a diameter of each lens. The expansion occurs symmetrically at center of unblocked PDMS and 1-Bromododecane interface. As a result, the PDMS lens array is achieved by this process.

This paper aims to describe a slanted liquid microlens array using diffusers. Ordinary liquid microlens has vertical side walls. The shape of it, however, has several weaknesses such as a low value of diopter and a difficulty in evaporating electrode. The diffuser causes UV light to spread slantly not straightly. This research shows a result of a slanted liquid micro lens having side walls with an angle of 74 degrees and verifies a high value of diopter and a well-filmed electrode. In order to achieve a high percentage of fill factor, it also presents matching values for refractive indices of the two media, oil and chamber.

Tunable liquid lens arrays can produce three dimensional images by using electrowetting principle that alters surface tensions by applying voltage. This method has advantages of fast response time and low power consumption. However, it is challenging to fabricate a high fill factor liquid lens array and operate three dimensional images which demand high diopter. This study describes a hybrid structure lens array which has not only a liquid lens array but a solid lens array. A concave-shape lens array is unavoidable when using only the liquid lens array and some voltages are needed to make the lens flat. By placing the solid lens array on the liquid lens array, initial diopter can be positive. To fabricate the hybrid structure lens array, a conventional lithographic process in semiconductor manufacturing is needed. A negative photoresist SU-8 was used as chamber master molds. PDMS and UV adhesive replica molding are done sequentially. Two immiscible liquids, DI water and dodecane, are injected in the fabricated chamber, followed by sealing. The fabricated structure has a 20 by 20 pattern of cylindrical shaped circle array and the aperture size of each lens is 1mm. The thickness of the overall hybrid structure is about 2.8mm. Hybrid structure lens array has many advantages. Solid lens array has almost 100% fill factor and allow high efficiency. Diopter can be increased by more than 200 and negative diopter can be shifted to the positive region. This experiment showed several properties of the hybrid structure and demonstrated its superiority.

In this paper, we used a thin polycarbonate (PC) chamber to improve the performance of an electrowetting lenticular lens array. The polycarbonate chamber changed the radius of curvature (ROC) of the oil acting as a lens, which increased the dioptric power of the liquid lens to 1666.7D. The increase in dioptric power required a reduction in the distance between the optical center of the lens and the display pixels under the chamber, which was accomplished by reducing the thickness of the chamber. The optimal thickness of the chamber was determined to be 0.5mm. Using this thin PC chamber, transmittance and viewing angle were measured and compared with an electrowetting lenticular lens with a conventional 1mm poly methyl methacrylate (PMMA) chamber was done. Crosstalk which degrades clear 3D images, is an inevitable factor in lenticular lens type multi-view systems. With the 0.5mm PC chamber, the viewing zone was expanded and the ratio of the crosstalk area was reduced, which resulted in a clear 3D image. The new method of depositing the electrode layer also ensured the uniform operation of the liquid lens array. (C) 2016 Optical Society of America

This study has established a robust and straightforward method for the fabrication of uniform poly(vinylamine) hydrogel capsules without using templates that combines the dispersion polymerization and the sequential hydrolysis/cross-linking. The particle sizes are determined by the degree of cross-linking as well as by the cross-linking reaction time, while the shell thickness is independent of these variables. Diffusion-limited reactions occur at the periphery of the particles, leading to the formation of hydrogel shells with a constant thickness. The treatment of the surfaces of hollow hydrogel capsules with oppositely charged biopolymers limits the permeability through the shell of species even with low molecular weights less than 400 g/mol. Furthermore, we demonstrated that the hydrogel shell phase decorated with Au nanoparticles can be optically ruptured by exposure to laser pulse, a feature that has potential uses in optically responsive drug delivery.

Corneocytes represents the main water reservoir of stratum corneum, and that ability intimately arises from their architecture and total composition. Here we describe a novel method for fabricating a microgel-in-liposome (M-i-L) structure consisting of a sodium hyaluronate microgel and a lipid membrane envelop in order to mimic corneocyte cell structures. The essence of our approach is to use a lecithin-based microemulsion with a very low interfacial tension between the water droplet and oil continuous phase. Using this emulsion enables us to stabilize a dispersion of microgel particles without phase separation or aggregation. The addition of excess water produced single-core or multicore microgel particles enveloped in a lipid layer. To demonstrate the applicability of this unique vesicle system, we encapsulated a high concentration of natural moisturizing factor (NMF) in the microgel core and investigated how the M-i-L structure affected the water retention in comparison with other control systems. We have observed that our M-i-L particles with the NMF in the core, which mimicked the corneocyte cell structure, showed an excellent ability to retain water in the system. This experimental result inspired us to investigate how corneocyte cells, which feature a lipid-enveloped hydrogel structure, provide such long-lasting hydration to the skin.

This study reports a facile and practical means to non-invasively deliver biologically active ingredients through the skin using polymer-based nanocarriers. For this, polymer nanocapsules were fabricated with different surface charges as well as glass transition temperatures and we observed their ability to deliver the encapsulated active ingredient, coenzyme Q10, through the skin layer. Direct imaging of a probe molecule, Nile Red, and a matrix polymer labeled with fluorescence moiety, Lucifer Yellow, allowed us to demonstrate that the probe molecule readily permeates into the deep skin, while the matrix polymer stays in the stratum corneum layer due to electrostatic interactions. Quantitative characterization of the penetrating amount of coenzyme Q10 using the Frantz cell method proved that, to achieve improved delivery efficiency, the nanocapsule should have a low glass transition temperature as well as positive surface charges.

Many consumers are interested in three-dimensional (3-D) technologies that make display images as real as possible. In response, a number of fairly mature 3-D technologies have already been introduced in various studies. Among them, we reviewed the integral imaging system and the multiview system, which can realize 3-D, from the past to the present. Those systems, however, suffer from problems such as depth range, two-dimensional (2-D) and 3-D conversions, and 3-D resolution. Therefore, a liquid lens is proposed as a technique to resolve the drawbacks. Using a liquid lens with variable focal length, the depth range was enhanced using a time-division multiplexing technique in an integral imaging system, and the function of 2-D and 3-D switching was enabled in a multiview system. Furthermore, methods were introduced to solve the problems of 3-D resolution reduction in multiview systems and vergence–accommodation conflicts in VR systems.

In this study, we demonstrate the role of a pH-sensitive polymer–liposome complex in enhancing the delivery and the efficiency of bioactive drugs into cells. For this purpose, we made vesicles composed of poly(methacrylic acid-co-stearyl methacrylate), phosphatidylcholine, and cholesterol. The complex is stable at pH values above 6, but the structure becomes slightly disorganized at pH 5. Below pH 5, the complex readily precipitates. We made drugs-containing (calcein or α-ketoglutaric acid) vesicle dispersions and examined its cellular uptake and biological activity in vitro. Our results indicated that the polymer–liposome complex effectively enhances calcein delivery into human keratinocytes compared to liposome, but both vesicles showed an equal distribution of calcein inside melanocytes. Also, treatment of human dermal fibroblasts by using αKG-containing polymer–liposome complex dispersion significantly enhanced their production of procollagen compared to cells treated with αKG-containing liposome dispersion. The results are discussed by connecting the pH-dependent structural change of this carrier with the acidic environment of endosomes in the cells. Overall, the pH-sensitive polymer–liposome complex prepared in this study appears to be promising for the cytoplasmic delivery of bioactive agents.

We demonstrate that the surface morphology and surface-wetting behavior of layer-by-layer (LbL) films can be controlled using different deposition methods. Multilayer films based upon hydrogen-bonding interactions between hydrophobically modified poly(ethylene oxide) (HM-PEO) and poly(acrylic acid) (PAA) have been prepared using the dip- and spin-assisted LbL methods. A three-dimensional surface structure in the dip-assisted multilayer films appeared above a critical number of layer pairs owing to the formation of micelles of HM-PEO in its aqueous dipping solution. In the case of spin-assisted HM-PEO/PAA multilayer films, no such surface morphology development was observed, regardless of the layer pair number, owing to the limited rearrangement and aggregation of HM-PEO micelles during spin deposition. The contrasting surface morphologies of the dip- and spin-assisted LbL films have a remarkable effect on the wetting behavior of water droplets. The water contact angle of the dip-assisted HM-PEO/PAA LbL films reaches a maximum at an intermediate layer pair number, coinciding with the critical number of layer pairs for surface morphology development, and then decreases rapidly as the surface structure is evolved and amplified. In contrast, spin-assisted HM-PEO/PAA LbL films yield a nearly constant water contact angle due to the surface chemical composition and roughness that is uniform independent of layer pair number. We also demonstrate that the multilayer samples prepared using both the dip- and spin-assisted LbL methods were easily peeled away from any type of substrate to yield free-standing films; spin-assisted LbL films appeared transparent, while dip-assisted LbL films were translucent.

We report the fabrication of free-standing multilayered thin films based on the layer-by-layer (LbL) deposition method. The isolation of multilayer thin film allows us to characterize the materials properties of such films in great detail. Poly(acrylic acid) (PAA) and hydrophobically modified poly(ethylene oxide) (HM-PEO) multilayer films have been prepared using the LbL method based upon hydrogen-bonding interactions. The LbL film composition and thermal properties were obtained as a function of the number of layer pairs using thermal gravimetric analysis (TGA) as well as differential scanning calorimetry (DSC). Above the critical number of layer pairs, the HM-PEO/PAA multilayer films exhibit complex surface structure owing to the hydrophobic nature of HM-PEO (i.e., micelle formation). The unique surface morphology was studied using optical microscopy and fluorescence microscopy, where pyrene dyes incorporated into the hydrophobic cores of HM-PEO micelles allowed us to monitor the sites of HM-PEO micelle...

We have studied how the hydrophobic character of amphiphilic polyelectrolytes influences their behavior in aqueous media. Specifically, we examined the association behaviors in aqueous media of poly(methacrylic acid) (PMAAc) and poly(methacrylic acid- co - n -alkyl methacrylate) with varying the alkyl chain length (12 and 18) and the mole percentage of the hydrophobic moiety (0–30 mol.%) in the polymer, and compared the microscopic and macroscopic behaviors of these polymers in deionized water and phosphate buffered saline (PBS) solutions (pH 3–7.4). Fluorescence studies showed that the amount of hydrophobic domain in the polymer aqueous solution increases as the mole concentration of the hydrophobic moiety in the polymer is increased, and that a long alkyl chain (C 18 ) has a higher hydrophobicity than a short alkyl chain (C 12 ). In measurements of the particle sizes in the aqueous polymer dispersions using photocorrelation spectroscopy (PCS), the results showed that the formation of nanoparticles, the size and pH-sensitivity of nanoparticles depend on the mole concentration and alkyl chain length of the alkyl methacrylate moiety.

This paper proposes an enhanced integral imaging system with an electrically controllable image plane to address the issue of the limited depth problem in integral imaging. For implementation of the variable image plane, a varifocal liquid lens array and driving device are adopted instead of an ordinary solid lens array. The position of the central depth plane is varied by adjusting the focal length of the lens array. The proposed system enables matching between the object position and depth plane electrically, and thus an object moving from 5.15 to 11.72 cm is clearly displayed with this method.

This study describes easy fabrication method for micro-lens array which has desired focal length in such a way that without the use of reflow technique. The process includes conventional lithographic process only which can be compatible with general semiconductor process. As constituent material, Negative photo-resist SU-8 with its developer PGMEA is used. Two main phenomena during lithography process are adjusted to expand the volume of the PR. During UV exposure, hardening proceeds from the top of the PR. Just after first exposure, using this property, very thin membrane on the top of the surface of the PR can be formed by short time exposure. In the development process, unexposed area of the PR is removed by chemical reaction with developer which causes the volume expansion if the unexposed area is covered with thin cured film. This method is to form the lens as the molecules in the volume are not easily escaped from the covered region. The thickness of the thin film depends on the exposure dose of 2mJ cm-2 μm-1 which determines the degree of expansion. The symmetrical volume expansion creates the membrane of lens shape and the focal length is directly related with second exposure dose. An extended research of affecting the change of the focal length of lens using volume expansion method by changing any other elements is discussed. This process can achieve a focal length selective for the applications of micro-optics.

This communication describes an enzyme stabilization method that allows the use of enzymes irrespective of environmental factors, especially heat, while maintaining their activity for a long time. We have designed enzyme microcapsules that consist of papain enzyme cores, poly (propylene glycol) interlayers, and poly(e-caprolactone) walls. By confocal laser scanning microscopy measurements and the thermal stability of papain-loaded microcapsules, it is demonstrated that the papain is surrounded by a hydrophobic polyol layer and stabilized by the exclusive volume effect. In our study, improved thermal stability can be obtained by using more hydrophobic long-chained polyols, which is understood to be attributed to the effective formation of a hydrophobic polyol layer between the papain and the polymer wall by means of conformational anchoring in the interface.

This study presents a different colloidal silver (Ag)/polymer system where Ag nanoparticles are deposited uniformly onto surface-functional porous poly(ethylene glycol dimethacrylate-co-acrylonitrile) (poly(EGDMA-co-AN)) microspheres. The formation and morphology of the composite microspheres were characterized from electron microscopy and X-ray diffraction analyses. The significance of the present report is that owing to the high affinity between Ag and nitrile group (CN) on the large surface of the microspheres, the Ag nanoparticles having a face-centered cubic phase were incorporated evenly into the deep pores of the microspheres with fine size and size distribution. In the preservation test, the Ag/poly(EGDMA-co-AN) composite microspheres obtained showed an excellent anti-bacterial performance, elucidating a high applicability for a new preservative.

In this study, a different UV (ultra-violet) ray absorption system is presented in which butyl methoxydibenzoylmethane (BMDM, a model UV-A absorbent, 320–400 nm) is stabilized in phase-controlled poly(methyl methacrylate) (PMMA) microspheres. The photochemistry of BMDM in the microspheres was investigated considering its phase characteristics therein. Analysis by differential scanning calorimetry and X-ray diffraction showed that the BMDM in the microspheres was present in a non-crystalline state. The phase control of BMDM in the polymer microspheres has an excellent ability to protect against UV-A, whilst maintaining its photostability and thermal stability. The results obtained in this study illustrate well that the phase control of the UV absorbents in polymer microspheres is another key factor that determines their photochemistry and photostability in the final formulations.