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A patient-specific phantoms, which are equivalent to human tissues, is needed in the experimental dosimetric verification before radiotherapy treatments. Most of the shape of gel phantoms have been structurally limited because of the fabrication method using mold technique. The present study focuses on direct freeform fabrication of gel phantom with the customized optical 3D gel printing system. Life-sized gel phantoms were replicated using conventional mold techniques, the 3D printer with two-step sequential free-radical polymerization process and inter cross-linking network gels as 3D printing materials. The gel phantoms are ultraviolet light-sensitive instead of radiation. The ultraviolet sensitivity of the gel phantoms (using mold techniques) with different molar ratios were experimentally evaluated with transmittance measurements, and were theoretically estimated by curve fitting to the observed data. This measurement gave us the insight that more vinyl monomers in the gel phantoms caused rapid polymerization and visibly opaque as well as conventional gel dosimeters. We confirmed that inter cross-linking network gel was 3D printable with the customized 3D printer, with resolution of fabrication 500 μm, as pre-finger-shaped phantom. The cross section of 3D printed gel phantom showed the distribution of opacity, that is, the distribution of UV irradiation. We expect that the 3D printer specialized gel materials and ICN gels are feasible for practical fabrication method of 3D gel phantom.

Hydrogels are known as a soft and water-rich material, and they are widely applied in the medical and industrial fields. On the other hand, when a liquid material is poured into a mold to make a gel, it is generally difficult to form a complicated shape due to the shape restriction included in the mold. To overcome this challenge, we have independently developed the 3D gel printer "SWIM-ER". This gel printing can make very complex structures that is unable to create by the hydrogel molding process. The our previous works includes soft robots for teaching, research, and surgical simulation and applications of 3D-printed organ models in hydrogel. However, it should be pointed out that due to the high economic cost, this printer is not popular. This study proposes an inexpensive gel printing technology using a commercially available stereolithography 3D printer equipped with liquid crystal display (LCD) or digital light processing (DLP) technology for UV irradiation. The price of a commercial 3D printer for general use ($500) is much cheaper than the price of a 3D gel printer. We have confirmed that our proposed method can perform three-dimensional modeling of gel by photopolymerization reaction under excitation of 405 nm. Figure 1

Soft hydrogel, which contains a amount of water and also has a unique touch feeling, will be required for practical applications around soft-matter robotics including the medical field because it has an unique softness that is close to the living body and has a biocompatibility. Among them, our SWEL developed RepRap SWIM-ER, a desktop type 3D gel printer that enables 3D free-formation of soft hydrogels. The RepRap SWIM-ER is a device that can shape the soft hydrogels into a desired shape by moving a laser pointer as the light source and irradiating the gel solution in the bathtub with ultraviolet light for photo-induced gelation. This 3D gel printer can be realized at low cost because it utilizes the results of the RepRap open source project to design the device and control it with software. Furukawa established the “Soft 3D Co-creation Consortium” (URL: https://soft3d-c.jp) in April 2018. Considering the members of this consortium as test users, we will provide a desktop type 3D gel printer RepRap SWIM-ER. First, in the field of research and development, we will use the 3D printing of soft hydrogel materials and share the practical use cases among the consortium members At the same time, we are planning to standardize the several methods concerning both the material design of 3D gel printers and the evaluation of shaped objects. Figure 1

Polymer gels containing a large amount of water have biocompatibility and appropriate softness close to living biological tissue. For this reason, many studies focus on how to use the polymer gels in medical field. The generally organ model is made of a silicone resin and is transparent and hard. Therefore, excellent in confirming the position of blood vessels and the like. But it is not suitable for practice or simulation using medical device. So, we aim to develop the gel organ model that overcomes these problems. We developed the desktop type 3D gel printer “RepRap SWIM-ER” which enables three-dimensional(3D) free printing of gels. RepRap SWIM-ER can move a light source at 405nm and form gels in the desired shape by localized photopolymerization. This gel printer irradiates a gel solution layer by layer with UV light. In the conventional printing process of RepRap SWIMER, it was difficult to change the photo polymerization reaction locally because constant speed, scan time and so on. There was also problem that it could use only one gel solution because it was bathtub type 3D gel printer. Here, we developed new printing process of RepRap SWIMER that can change the transparency and mechanical properties of printed gels locally by changing the printing parameters such as the scan times of UV light. It can control gel turbidity which was previously only printed in a single color. This method can print two types of gel (transparent and white) only using RepRap SWIM-ER. By changing the printing conditions with RepRap SWIM-ER, a transparent gel with length and breadth of 20 mm, thickness of 2 mm and a white gel lattice can be printed at about 10 minutes. The transmittances of printed transparent gels and white gels were measured by a spectrophotometer to examine the color change (Figure 1). It can be seen from Fig.1, The white turbidity of the gel changes when the printing conditions are changed. This result showed that the appearance of color varied depending on the concentration of the hydrophobic initiator TPO used in the gel solution. At the prototype, we tried to print using kidney data. From previous research, we have known that the gel prepared by soaking in pure water swells 1.5 to 2.0 times. In consideration of this result, when printing kidney data using RepRap SWIM-ER, it was printed at 70% of the size of the data, the color was entirely white. After swelling, this model became to be about the same size as the actual data. The kidney 70% data can be printed at 2h30min. We can create new gel organ models by using RepRap SWIM-ER and the above gel printing method. Gel organ models makes it possible to use medical devices and makes the touch feeling more realistic. For example, soft-transparent gel (organ model) and hard-white gel (blood vessel, tumor) can make the model with high precision and complexity. In addition, this technology can let the production spend lower cost and less time. Figure 1

In order to construct the artificial cells and to understand the physicochemical properties of living cells, it is important to clarify the cell-sized confinement effect on the behaviours of bio-inspired polymers. We report the dynamic behaviours of aqueous hydroxypropyl cellulose (HPC) solution coated with phospholipids in oil (water-in-oil droplets, W/O droplets), accompanied by an increase in the temperature. We directly observed the beginning of phase separation of HPC solution using a fluorescence microscope and confirmed the dependence of such phenomena on droplet size. The results indicate that the start time of phase separation is decreased with an increase in droplet size. The experimental results suggest that the confinement situation accelerates the phase separation of aqueous HPC solutions.

United Nations set the goal to maintain the richness of the sea in SDGs. In Japan, they are aiming for broad spectrum and real time of ocean information collection. Various kinds of underwater exploration techniques have been developed. For instance, submersible research vehicles and autonomous underwater vehicle (AUV) have been used for observation of underwater conditions, in addition to the technique of fixed-point observation. However, such research vehicles and conventional AUV are difficult to control, are expensive, and are usually made with non-biodegradable materials such as metals. For this problem, we came up with the robot composed by only organic material. This idea realizes the recycling society. Jellyfish is the most efficient swimmers, traveling for long distance with saving energy by drifting in the ocean, its body can be decomposed after death, and safe for surrounding creatures. Therefore, we are developing the jellyfish-mimic AUV using a hydrogel. For designing a Jellyfish-mimic AUV robot, it is preferable to introduce a soft actuator driven by water pressure, as it requires low electric power and it is eco-friendly. Here, we report a 3D printing hydrogel hydraulically-driven soft actuator that can make a bending motion of umbrella-shaped bell of artificial Jellyfish. We utilized the Pneunets Bending Actuator for designing the actuator, and the detailed information of this actuator is shown in the website of Soft Robotics Toolkit (see https://softroboticstoolkit.com/book/pneunets-bending-actuator). We changed the parameters of 3D print speed and UV light power gel concentration when we make some gel actuators. In addition, we measured and evaluated these performances. Finally, we are making the robot to use it and be composed by only organic materials so that we can release many robots at the same time.

The 3D Gel Printer Soft and Wet Industrial Materials・Easy Realizer (SWIM-ER) developed by Furukawa et al. It can only perform modeling with monochrome. Therefore, it is thought that new elements will be born by developing a new 3D Gel Printer. However, there are many problems in developing it. In this study, we aim to develop a system that displays the composition of gels for obtaining color gels of target color, and apply it to gel printer. The color gels used pigments, and mixing them showed the change of color of the gels. Moreover, by mixing the pigments, gels with a wide range of color variations could be obtained.In the future, we will study the improvement of accuracy by collecting more samples and the technology to actually color the gels.

3D printing technology has been becoming more common and diverse for various researches and developments. Here we focus on 3D printing of soft-matter, especially introducing the latest progress of our 3D gel printing. We are developing various 3D gel printers, including bath-tub type, dispenser type and brick-building type. These printers can 3d-print finger tips for robotics, medical models for surgery, and fun foods for playing and nursing. The minimum and maximum dimensions of 3D printed objects depend on both the type and the materials used in printing. We will discuss what we need to study for leading Soft-matter 3D Innovation.

Various kind of gel materials for example tough double network hydrogels [1], shape memory hydrogels [2] and ionic gels [3] have been developed with potential in numerous sectors. The transparent, flexible and low friction properties of these gels have added different prospects in scientific and technological areas. Utilization of 3D printing in fabrication of gel materials is still in its infancy and thus hindering rapid prototyping and design freedom. In this work, we have fabricated smart gels like thermos-responsive gels and conductive gels etc. using both customized optical gel 3D printers named SWIM-ER and commercial printer named Acculas. This process of 3D printing enabled rapid and moldless fabrication of smart gels with variety of 3D design from macro to micro scale. Robust thermos-responsive Poly (dimethyl acrylamide-co-stearyl acrylate and/or Lauryl Acrylate) (PDMMAm-co-SA and/or LA)-based shape memory gels (SMGs) with tunable mechanical, thermal, swelling, and optical properties are obtained by optimizing their critical conditions during 3d printing. The superior physiochemical properties of such smart gels widen the range of applications for soft robotics, biomedicine, flexible electronics, mimicking organ structure, bioinspired lens and sensing applications. References Gong, J. P., Katsuyama, Y., Kurokawa, T., Osada, Y., “Double-Network Hydrogels with Extremely High Mechanical Strength,” Adv. Mater., 15, 1155-1158 (2003). Kabir, M.H., Ahmed, K. Furukawa, H., Microelectron. Eng. 150, 43–46 (2016). Ahmed, K., Watanabe, Y., Higashihara, T. Arafune, H. Kamijo, T., Morinaga, T. Sato, T., Makino, M. Kawakami, M., Furukawa, H. Microsyst Technol 22, 17 (2016).

Today, intravascular catheter surgeries, which are kind of minimally invasive procedures, are widely used surgical techniques. As compared to conventional open surgery, incision size is small, and burden on patients is reduce. Therefore, the wounds associated with pain is small, and time to heal is also short. On the other hand, since operative field was restricted during surgery, operators need to have sufficient skill for intravascular catheter surgeries. To obtain it, operators must practice using artificial surgical simulators. Materials for surgical simulators are requires having physical properties as like human organs. Although lab animals have similar physical properties, they are not appropriate from an ethical perspective. Moreover, recently, silicone-based materials are used for surgical simulators, but their physical properties do not mimic those of human organs. Gel materials are expected for materials of surgical simulators, because their mechanical properties are similar to human organs and they contain large amounts of moisture. Besides, gel material can apply for fabrication of the complicate shape of human organs using 3D printer. The issue of practice using conventional surgical simulators is quantitative evaluation of operator skill. In the case of intravascular catheter surgeries, measurement of applied force to vessel wall by catheter and guide wire is an important function. Since vessel walls of patients are delicate, if devices applied excess force, and unexpected accidents such as vascular occlusion are attracted. In this study, we focused on the photoelasticity of gel materials. If vessel models are made of these gel materials, it is possible them to evaluate quantitative score of operator skill. To realize these surgical simulators, we developed the stress measurement system for photoelasticity of gel materials. Besides, we evaluated the physical properties such as mechanical properties and photoelastic coefficient of several gel materials using our developed system. We constructed new stress measurement system for photoelasticity of gel materials Our system consisted of several polarizers and wave plates, and it could measure the value of stress and direction of stress in X-Y plane from RGB values on color map. In order to minimize the overlap ratio of the same color in the color map, two 1 wave plates were insert to conventional observation system of circularly polarized wave and the insertion angle of two 1 wave plates is 30 degrees. We suggested analysis algorithm which enables to eliminate the effects of incident light and ambient light. As the results, we succeed to measure the tensile stress by our system during the tensile test of PVA hydrogel. Measurement error was less than 6.3% at the stress range from 0 to 80 kPa, and it is sufficient measurement resolution for evaluate stress during practice of intravascular catheter surgeries. Generally, Young’s moduli of human vessels depend on the organ and/or symptoms, and they are ranged from 0.02 to 3 MPa. Although mechanical properties of gel material can be adjusted by changing kinds of formulas and their concentrations, it is difficult that only one type gel coverall the range of Young’s moduli of human vessels. Therefore, the materials of surgical simulators are selected on demand from patient of case history. Finally, we investigated the Young’s moduli and photoelastic coefficients of two types of designable gels such as inter cross-linking network gels and double networks gels. As the results, two type gels exhibited photoelasticity. Young’s moduli of inter cross-linking network gels are approximately 1 MPa and the effect of formula concentration was slightly. On the other hand, the range of Young’s modulus of double networks gels was 0.12 to 0.77 MPa for strain range from 0 to 15%, and it was within the range of Young’s modulus of human vessels. Their photoelastic coefficients were 0.012 to 0.022 ×10-9 Pa-1. The measurement error of our system was 7.3%, and was acceptable.

NIPA-Bis gels with low fraction of cross-linkers undergo discontinuous volume change at the specified temperature in water (Volume phase transition). Concerning the critical behavior of gels, NIPA hydro-gels with BIS (NIPA-BIS gels) are the most well studied gels. Y. Li et al. (1) and K. D. Arai et al. (2) obtained the critical exponents of NIPA-BIS gel. One of the most extreme gel with multi-functional crosslinker is a hydrogel crosslinked with small crystals of Laponite reported by K. Haraguchi et al. (3); single Laponite crystal consists of about 2000 unit cells on average, and it has discotic form with diameter of about 30 nm and thickness of about 1.0 nm in aqueous solution. When the Laponite crystals are used as cross-linker, each crystal crosslinks a few thousand of chains due to the silanol groups on the surface of the crystal. The NIPA-Laponite gels change the volume drastically by the temperature change and these gels are tough against external force. However, discrete volume change (volume phase transition) was not observed even at the very low fraction of crosslinker. This fact indicates that the number of the crosslinkers are very small compared to the BIS crosslinker, and the structure of the gels become very inhomogeneous. Using the inhomogeneity as the keyword, we will discuss about the hysteresis loop and minor loops observed from NIPA-Lapomite gel. References (1) Y.Li and T.Tanaka, J.Chem.Phys.,90, 5161,(1989). (2) K. D. Arai, A. Saito, K. Ito, Y. Uematsu, T. Ueno, Y. Fujii, and I.Nishio, Phys. Rev. E 87, 022603, (2013). (3) K. Haraguchi, T. Takehisa, and S. Fan, Macromolecules, 35, 10162 (2002). Figure 1

In recent years, various high-strength gels having strength of several MPa have been developed one after another by devising the internal structure of the gel. They have attracted attention as a new material. High-strength double network gel (DN gel) is a gel consisting of a hard 1st network and a soft 2nd network and have excellent properties such as super low friction, flexibility and biocompatibility. Particle double network gel (P-DN gel) consisting of powdered 1st network and 2nd network is a high strength gel capable of 3D free form fabrication by using 3D gel printer. Utilizing these advantages, there are expectations for soft robot materials and mechanical materials. It is also important to grasp the number of deformation of the gel and how much fatigued it is when the gel material is industrially used. Specifically, by attaching a fatigue sensor to a soft robot, it is possible to predict the optimum time to replace the parts. When it is used for mechanical materials, we need to judge on the necessity of emergency treatment. It will be considered to lead to comfortable use of things. In this study, we aimed to develop a gel fatigue sensor with reference to the internal structure and destruction phenomenon of P-DN gel. P-DN gels of various compositions were prepared and mechanical tests and evaluation of internal structure by dynamic light scattering were carried out to investigate the physical properties of these gels. As a result, the P-DN gel using super absorbent polymer (SAP) as the 1st gel showed the most suitable physical properties for use as a fatigue sensor.

Various kinds of cell model systems have been utilized for fundamental studies on physical properties of cells. Water-in-Oil (W/O) droplet system coated with phospholipids is one of the beneficial simple model systems of living cells. For instance, a biomimetic phase-separated membrane was constructed in the W/O systems with phospholipid mixture (Hamada et al., J. Phys. Chem. Lett., 2010) since phase separation in lipid membrane system corresponds to the separation between lipid raft domains and other soft domains in the living cell membranes. Phase transition of a polymer has been studied for many years, such as coil-globule transition (Nishio et al., Nature, 1979), and helix-coil transition (Tanaka et al., J. Chem. Phys., 1973). In addition to the phase transition of polymers, phase separation in a binary polymer solution was also reported (Yanagisawa et al., J. Mol. Liq., 2014). However, cell-sized confinement effects on polymer solutions have been poorly confirmed. To clarify the cell-sized confinement effects on polymer solutions, we previously observed the dynamic behavior of polymer droplets (Yoshida et al., Polymers, 2017). The previous study revealed that droplet size influences the start time of phase separation in the case of temperature change from 10 to 65 degrees Celsius. In this study, we observed the dynamic behavior of hydroxypropyl cellulose (HPC) solution droplets in response to temperature change from 10 to 65 degrees Celsius using a fluorescence microscope. The droplets were coated with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) or 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE). As a control, we observed non-coated water droplets. DPPC and DPPE are widely used for studies on model cell membranes. Using time-lapse images, we confirmed the water/HPC distribution using a spatial autocorrelation function. The results revealed that water-rich region appeared in the case of lipid coated droplets with increase in temperature while such phenomenon was not observed in the case of non-coated droplets.

Since the gel has soft physical properties, it was difficult to process by conventional cutting or casting, but 3D gel printer was developed, and three-dimensional free modeling of the gel became possible. In this study, it is presented that the relationship between printing parameters of a 3D gel printer "Soft and Wet Intelligent Matter-Easy Realizer (SWIM-ER)" and mechanical properties of the fabricated gel objects by SWIM-ER. The printer can fabricate hydrogel objects by scanning of ultra-violet (UV) light irradiation (photopolymerization). Various hydrogels objects were printed with different scanning velocity of UV light. We measured the water content and mesh sizes of gel objects utilizing Scanning Microscopic Light Scattering (SMILS). Furthermore, we also printed the gel objects with multiple scan rates with constant UV light irradiation energy, and measured sizes of gel objects, and performed the compression test. It was observed that the physical properties of printed hydrogel objects are strongly related with 3D printing parameters due to difference in crosslinking density of polymer network.[1] Ref. [1] Takafumi Ota, et al., Mechanical Engineering Journal, 5, 1, 17-00538 (2018).

Catheterization procedure is a typical example of minimally invasive medical treatment. This has the advantage that the physical burden on the patient can be remarkably reduced as compared with the conventional medical treatment method involving craniotomy or hemorrhage etc. However, on the other hand, since visual and tactile restrictions are limited at the time of surgery, physicians are required to have expert skill and many experiences. To raise the success rate of surgery irrespective of the amount of surgical experience, we have conducted a simple model using a glass tube and a simulation operation using an experimental animal, but they have low bio-reproducibility and ethical problems was there. In recent years, due to the development of new materials and the appearance of 3D printers, shape reproducibility has improved. A more desirable function of the surgical simulator is to visualize the force applied to the vessel wall surface by the catheter. This is because there is a danger of attracting vascular occlusion etc. when a large force is applied to the wall surface of the blood vessel. Therefore, it is considered important to quantitatively evaluate the operational feeling for simulated surgery. Therefore, we aim to manufacture a vascular surgical simulator with high bio-reproducibility that enables real-time stress measurement. In this research, stress visualization method using photoelastic effect is applied to surgical simulator. By using the photoelastic effect, it becomes possible to check the stress state of the entire field of view, and it is possible to obtain a stress state when a medical instrument such as a coil or a stent is inserted. Therefore, it is useful not only for training but also for the development of medical instruments. Heretofore, examples using PDMS and polyurethane elastomer as a surgical simulator material have been reported, but the longitudinal modulus of elasticity is high and it is unsuitable for a blood vessel model. Therefore, we focused on PVA hydrogel as surgical simulator material. PVA (polyvinyl alcohol) hydrogel is a material that can be expected to reproduce vascular tissue because its physical properties can be easily changed by changing the compounding ratio and degree of polymerization of powdered PVA. By changing the compounding ratio of powdered PVA in the range of 4-15 wt.%, We realized PVA hydrogel's longitudinal elastic modulus of 60-450 kPa. Since the longitudinal elastic modulus of human vascular tissue is 20-3000 kPa, PVA hydrogel is useful for reproducing soft vascular tissue. Further, the average photoelastic coefficient of PVA hydrogel is 2.30 × 10-9 Pa-1, which has a photoelastic coefficient greater than that of polyurethane elastomer which is a photoelastic material useful for photoelastic stress measurement. (photoelastic coefficient of polyurethane elastomer is 1.45 × 10-9 Pa-1.) Therefore, it was confirmed that it is a useful material for stress measurement using photoelastic effect. In this study, a simple blood vessel model was prepared using PVA hydrogel and simulated surgery using a catheter was performed. In addition, a photoelastic observation system was constructed for stress measurement, and a method for correcting the influence due to the presence of incident light, ambient light, and initial stress was examined. As a result, we successfully extracted and visualized the stress applied to the simple blood vessel model.

Various kinds of underwater exploration techniques have been developed. For instance, submersible research vehicles and autonomous underwater vehicle (AUV) have been used for observation of underwater conditions, in addition to the technique of fixed-point observation. However, such research vehicles and conventional AUV are difficult to control, are expensive, and are usually made with non-biodegradable materials such as metals. In contrast, jellyfish is the most efficient swimmers, traveling for long distance with saving energy by drifting in the ocean, its body can be decomposed after death, and safe for surrounding creatures. Therefore, we are developing the jellyfish-mimic AUV using a hydrogel. For designing a Jellyfish-mimic AUV robot, it is preferable to introduce a soft actuator driven by water pressure, as it requires low electric power and it is eco-friendly. In this study, we prototyped a Jellyfish-AUV robot using a soft material and a soft actuator. While it is ideal to make a robot body with hydrogel it is difficult to make the actuator with hydrogel. Here, we report a silicone-based hydraulically-driven soft actuator that can make a bending motion of umbrella-shaped bell of artificial Jellyfish. We utilized the Pneunets Bending Actuator for designing the actuator, and the detailed information of this actuator is shown in the website of Soft Robotics Toolkit (see https://softroboticstoolkit.com/book/pneunets-bending-actuator). The actuator is composed of inflation parts, basis, and copy paper placed between them. We poured into the 3D printed mold made with polylactic acid (PLA) and preserved at room temperature for 4 h to cure the silicone parts (inflation parts and basis). Copy paper was sandwiched between inflation parts and basis. The size of copy paper was 30 mm × 5 mm. Then, we poured additional silicone resin to combine the parts. By inserting a toothpick into the mold, we made the insertion port of the silicon tube. Before curing, we removed the air bubbles for 20 minutes with a vacuum de-foaming device. Finally, we inserted a silicon tube into the fuselage and attached a syringe for air supply. The behavior of the actuator in salt water was evaluated by image analysis, and the shrinkage factors of gel robots were compared with that of real jellyfish. The results were obtained as shown in Figs.1, 2 and 3. The shrinkage ratio of the jellyfish robot was 46.4 % at the maximum in the case of air injection of 2.8 cm³. The ratio did not reach 56.3 % at the maximum shrinkage ratio of the real jellyfish. To achieve the 56.3 % shrinkage ratio, we have to improve the maximum volume of injection air. Consequently, we have concluded there is a possibility that this actuator can reproduce jellyfish movement.

Recently, several full-color 3D printers have been proposed. However, there is no full-color 3D printer using gel as a material yet. The 3D gel printer Soft and Wet Industrial Materials Easy Realizer (SWIM-ER) also performs modeling with monochrome only. To realize a full-color 3D gel printer, there are many problems such as a color gel material, a printing system with multi-material, etc. In this study, we examined pigmented color gel materials. First, several pigments were mixed to prepare a gel solution, which were measured for color. It was found that the addition of the surfactant dispersed the pigment and the fracture from the aggregated part was also improved. For some pigments, the relation between pigment concentration and color gel’s brightness or their saturation was clarified. The color of the neutral color gel made by mixing the specific two pigments was measured. The relation between the ratio and the color when the mixture ratio of the two color pigments was changed became clear. To make all color gel materials, a large amount of sample data of color gel is required. Therefore, we used pipetting robot “Andrew” to automatically prepare color gel materials to improve the efficiency of data collection. We propose an algorithm to determine the recipe for synthesizing the gel of the target color by using this database and a system to automatically synthesize the gel of the target color.

The purpose of this study is to evaluate effect of hypoxic water and blue tide on macrobenthos in artificial tidal flat, Omaehama in inner part of Osaka bay. Hypoxic water influences on macrobenthos to survive under to 1m water depth. In addition, it was revealed that bule tide influences on the amount of filtered water by Ruditapes philippinarum in DL±0m water depth. Blue tide decreased individual of R. philippinarum and the amount of filtered water by them. It is found that the creating artificial tidal flat enhances the number of R. philippinarum and filtaration, but occurrence of blue tide causes disappearance of purification function. These result indicated that it is necessary to consider the method for mitigation of blue tide impact when creating artificial tidal flat.

Background Trauma-focused cognitive behavioral therapy is used to treat children who have experienced traumatic events and suffer from trauma-related disorders. Its effectiveness has been demonstrated in several randomized controlled studies. However, most of these studies have been performed in the United States, with few studies conducted in Asian countries. Therefore, we aimed to evaluate the feasibility of trauma-focused cognitive behavioral therapy in children who have experienced traumatic events and who suffer from trauma-related disorders in Japan. Findings Thirty-five traumatized children (mean age = 10.9 years; range = 3–17 years; 74.3% girls) who received trauma-focused cognitive behavioral therapy were included. The effectiveness of the program was evaluated in each case using the University of California at Los Angeles Post-Traumatic Stress Disorder Reaction Index for DSM-IV for trauma-related symptoms and the Children’s Global Assessment Scale for social functioning. Pre- and post-treatment outcome measures were analyzed using two-tailed paired t tests. The results for 35 participants indicate that post-traumatic stress symptoms were significantly improved following therapy [t(35) = 8.27; p

3D printing is getting quite attractive now and this technology will be useful to make new micro devices and systems for life-innovation. Recently our research group has developed several types of 3D gel printers and now focuses on the application of the 3D gel printers to create new soft and wet systems. We believe the 3D gel printers and their applications will give a huge breakthrough in industrial and mechanical engineering in future.

Various laboratory experiments were performed to examine the effects of H2S (Hydrogen Sulfide) on R. philippinarum in this study. These results were as follows. 1) Most of clam closed its shell, in case was placed in the anoxic water. However, the number of clam that opened its shell increased with time. 20 hours later, the dying clam appeared after the clam extended the siphon and pelecypod. 2) H2S exposure had an insignificant effect on the clam, they closed shells. However, the clam was significantly affected by H2S exposure when they opened its shell and extended siphon and pelecypod. 3) When the water was hypoxic or anoxic before Blue tide occurrence (Aoshio), the clam would directly suffer severe effects of H2S because the extended soft tissue from the inside of shell was exposed.

Purpose: Mobility disorders of the alimentary tract including irritable bowel syndrome (IBS) is now increasing worldwide. Measurement of intracolonic pressure has been conventionally employed for assessment of colonic motility. However, it is very laborious and burdensome for a routine examination. Therefore, in this study, we performed electrocolonography (ECoG), an easy and simple methodology, and investigated its usefulness for evaluation of colonic motility in comparison with the conventional methodology. Method: Twenty-five well-informed healthy volunteers were enrolled. ECoG was performed using a portable electrogastrograph (NIPRO EGG, A&D, Tokyo, Japan). After detecting a sigmoid colon using external ultrasonography, 4 electrodes of ECoG were attached to the abdomen. The ECoG was recorded by a bipolar lead between the central electrode and 3 surface probe electrodes (Ch1-3) at 1-second interval with frequencies of 1.5-6.0 cpm. Mosapride (10mg) or butylscopolamine (10mg) was orally administered during the examinations. For the analysis of ECoG data, the dominant frequencies and peak powers in 3 channels were calculated using a Fast Fourier Transform. In the 3 subjects, intracolonic pressure was measured using mobility visualization system (ManoScan 360, Sierra Scientific Instruments, CA) concurrently with ECoG. A catheter with 36 pressure sensors was introduced through the anus to the sigmoid colon, and the change of the pressure at each point was recorded. Results: Colonic peristalsis at about 2 cpm (1.95 0.41 cpm) was observed by mobility measuring system. The pressure was significantly increased by administration of mosapride, and was decreased by butylscopolamine, consistent with the previous reports. While, a dominant frequency at 2 cpm, which represented action potential of colonic peristalsis, was observed in all channels of ECoG. The peak power of the dominant frequency was significantly increased by mosapride (pre 15.0 ± 7.38uV, after 52.0 ± 50.3uV) and was significantly decreased by butylscopolamine (pre 15.2 ± 6.27uV, after 0.35 ± 0.24uV), corresponding to the change of intracolonic pressure. The dominant frequency did not change after administration of mosapride or butylscopolamine in ECoG. Conclusion:We could detect action potential of colonic peristalsis by ECoG, an easy and simple methodology, and showed the usefulness of ECoG for assessing colonic motility.