Colloidal photonic crystals possess inimitable optical properties of iridescent structural colors and unique spectral shape, which render them useful for security materials. This work reports a novel method to encrypt graphical and spectral codes in polymeric inverse opals to provide advanced security. To accomplish this, this study prepares lithographically featured micropatterns on the top surface of hydrophobic inverse opals, which serve as shadow masks against the surface modification of air cavities to achieve hydrophilicity. The resultant inverse opals allow rapid infiltration of aqueous solution into the hydrophilic cavities while retaining air in the hydrophobic cavities. Therefore, the structural color of inverse opals is regioselectively red-shifted, disclosing the encrypted graphical codes. The decoded inverse opals also deliver unique reflectance spectral codes originated from two distinct regions. The combinatorial code composed of graphical and optical codes is revealed only when the aqueous solution agreed in advance is used for decoding. In addition, the encrypted inverse opals are chemically stable, providing invariant codes with high reproducibility. In addition, high mechanical stability enables the transfer of the films onto any surfaces. This novel encryption technology will provide a new opportunity in a wide range of security applications.

Photonic microdisks with a multilayered structure are designed from photocurable suspensions by step-by-step photolithography. In each step of photolithography, either a colloidal photonic crystal or a magnetic-particle-laden layer is stacked over the windows of a photomask. Sequential photolithography enables the creation of multilayered photonic microdisks that have brilliant structural colors that can be switched by an external magnetic field.

reactions of color pigments whose rate strongly depends on temperature lead to temperature-and time-dependent color change. [13][14][15][16] The plasmonic color of metal nanoparticles can be varied by temperature-and time-dependent shape change for nonspherical nanoparticles [17] and shell growth. [18] However, these approaches require a liquid medium, which severely restricts their uses. To overcome these limitations, the thermal recorders have been designed in a liquid-free film format. For example, dewetting of polymer film on an inorganic substrate causes noticeable color contrast, where the rate of the dewetting is temperature-dependent. [19] Mechanically embossed liquid crystal polymer film returns to its original form, showing a structural-color change when heated above the glass transition temperature. [20] Phase separation of fluorescent molecules in a polymer film by heating above the glass transition temperature induces dye aggregation and forms excimers that exhibit an irreversible fluorescent-color change. [21,22] These approaches are free from a liquid medium and provide a wider range of recordable thermal input. However, it is elusive to decouple temperature and time from the color change.Here, we use thermal creep behavior of polymeric inverse opals whose matrix is made of negative photoresist. The inverse opals, attached on a solid substrate, show shrinkage along the thickness direction through thermal creep while maintaining regularity of their cavity array. This anisotropic compression leads to a blueshift of the structural color. The magnitude of the blueshift is influenced by both temperature and time whose coupling is described by the superposition principle. As the matrix of the inverse opals is made of negative photoresist, their cross-linking density can be simply adjusted by ultraviolet (UV) dose, which determines the rate of the blueshift. Therefore, an invisible pattern with regioselective UV doses on the inverse opals turns into a multicolor pattern for thermal input. From the multiple structural colors on the single pattern, temperature and time can be decoupled with multiple superposition equations and separately estimated for isothermal condition. This patch-type inverse opal is potentially useful as disposable indicators.Inverse opals are composed of spherical cavities that are arranged to have a close-packed face-centered cubic (fcc) lattice in a solid matrix. When the inverse opals are heated up, the cavities isotopically shrink to minimize surface energy, finally forming a dense body in the absence of any regular pores. [23] Recording thermal conditions, i.e., temperature and time, is of great importance for various applications. Although thermometers can measure temperature and record its temporal change with electronic devices, they are nondisposable and not patch-type, restricting their uses. Here, photonic films are designed that record thermal condition through irreversible structural deformation and intuitively report it with color patterns. The photonic films are inverse...

Melt-spun poly(trimethylene terephthalate) (PTT) fibers were zone-drawn and the structures and properties of the fibers were investigated in consideration of the spinning and zone-drawing conditions. The draw ratio increased up to 4 with increasing drawing temperature to 180°C, at a maximum drawing stress of 220 MPa. Higher take-up velocity gave lower drawability of the fiber. The PTT fiber taken up at 4000 rpm was hardly drawn, in spite of using maximum drawing stress, because a high degree of orientation had been achieved in the spinning procedure. However, an additional enhancement of birefringence was observed, indicating a further orientation of PTT molecules by zone drawing. The exotherm peak at 60°C disappeared and was shifted to a lower temperature with an increase in the take-up velocity, which means that the orientation and crystallinity of the fiber increased. The d-spacing of (002) plane increased with increasing take-up velocity and draw ratio, whereas those of (010) and (001) planes decreased. In all cases, the crystal size increased with take-up velocity and draw ratio. The cold-drawn PTT fiber revealed a kink band structure, which disappeared as the drawing temperature was raised. The physical properties of zone-drawn PTT fibers were improved as the draw ratio and take-up velocity increased.

Lower survival rates were observed for the implant placed in the anterior maxilla. The purpose of this study was to investigate the influence of different implant lengths on the stress distribution around osseointegrated implants under a static loading condition in the anterior maxilla using a three-dimensional finite element analysis. The diameter of 4.0 mm external type implants of different lengths (8.5 mm, 10.0 mm, 11.5 mm, 13.0 mm, 15.0 mm) was used in this study. The anterior maxilla was assumed to be D3 bone quality. All the material was assumed to be homogenous, isotropic and linearly elastic. The implant-bone interface was constructed using a rigid element for simulating the osseointegrated condition. Then, 176 N of static force was applied on the middle of the palatoincisal line angle of the abutment at a 120°angle to the long axis of abutment. The von Mises stress value was measured with an interval of 0.25 mm along the bone-implant interface. Incremental increase in implant length causes a gradual reduction of maximum and average von Mises stress at the labial portion within the implant. In the bone, higher stress was concentrated within cortical bone area and more distributed at the labial cortex, while cancellous bone showed relatively low stress concentration and even distribution. An increase in implant length reduced stress gradients at the cortical peri-implant region. Implant length affects the mechanisms of load transmission to the osseointegrated implant. On the basis of this study the biomechanical stress-based performance of implants placed in the anterior maxilla improves when using longer implants.

Cancer is one of the most common causes of death globally. Despite extensive research and considerable advances in cancer therapy, the fundamentals of the disease remain unclear. Understanding the key signaling mechanisms that cause cancer cell malignancy may help to uncover new pharmaco-targets. Cyclic adenosine monophosphate (cAMP) regulates various biological functions, including those in malignant cells. Understanding intracellular second messenger pathways is crucial for identifying downstream proteins involved in cancer growth and development. cAMP regulates cell signaling and a variety of physiological and pathological activities. There may be an impact on gene transcription from protein kinase A (PKA) as well as its downstream effectors, such as cAMP response element-binding protein (CREB). The position of CREB downstream of numerous growth signaling pathways implies its oncogenic potential in tumor cells. Tumor growth is associated with increased CREB expression and activation. PKA can be used as both an onco-drug target and a biomarker to find, identify, and stage tumors. Exploring cAMP effectors and their downstream pathways in cancer has become easier using exchange protein directly activated by cAMP (EPAC) modulators. This signaling system may inhibit or accelerate tumor growth depending on the tumor and its environment. As cAMP and its effectors are critical for cancer development, targeting them may be a useful cancer treatment strategy. Moreover, by reviewing the material from a distinct viewpoint, this review aims to give a knowledge of the impact of the cAMP signaling pathway and the related effectors on cancer incidence and development. These innovative insights seek to encourage the development of novel treatment techniques and new approaches.

The purpose of this study was to compare the accuracy of impression taking method using the encoded healing abutment, scan body and pick-up impression coping with different implant angulations. Materials and Methods: Master model was fabricated by 3D printer and three implants were placed into the model with 0°, 10° and 20° mesial angulation. The abutments were secured to each implants and master model was scanned to make a reference model. Group P model was fabricated using pick-up impression copings and model was scanned after securing the abutments. Encoded healing abutment (Group E) and scan body (Group S) were secured on the master model and digital impression was taken using intraoral scanner 15 times each. Each STL files of test groups were superimposed with reference model using best fit alignment and root mean square (RMS) value was analyzed. Results: The RMS values were lowest in Group P, followed by Group S and Group E. Group P showed significant difference with Group S and E (P < 0.05) while there was no significant difference between Group S and E. Correlation between implant angulation and RMS value was significant in Group E (P < 0.05). Conclusion: The pick-up impression coping method showed higher accuracy and there was no significant difference in accuracy between the healing abutment and the scan body. The clinical use of the encoded healing abutment is possible, but it should be used with caution in the case of angulated implant.

monodisperse colloids are limited to polystyrene (PS), poly(methyl methacrylate), silica, and few others. [17][18][19][20] Inverse opals, the negative replica of the opals, have been prepared to overcome the limitations of opal structures. [21][22][23][24] As the air cavities with fcc lattice are embedded in a monolithic matrix, the inverse opals show enhanced mechanical stability. Moreover, the matrix materials can be selected from the abundant as long as infiltration process in interstitial voids of opal templates is available; colloidal materials should be carefully selected for their selective removal process. [21,23,[25][26][27][28] Therefore, a high contrast of refractive index and new functionality beyond the bandgap property can be achieved with inverse opals, which have served as useful motifs in diverse applications, including sensors, optical devices, anticounterfeiting patches, catalysts, and porous electrodes. [5,20,27,[29][30][31][32][33] The inverse opals whose matrix is made of biodegradable polymers are expected to show time-dependent discoloration upon slow degradation of the periodic structures. Such a material is potentially useful as indicators of effective periods for drug and cosmetic products, and edible anticounterfeiting materials for drugs and foods. However, it is still challenging to prepare inverse opals with biodegradable polymers in a robust and reproducible manner because controlled infiltration of the target matrix materials into narrow interstitial voids is elusive.In this work, we report a pragmatic approach to fabricating inverse opals with the biodegradable matrix for controlled discoloration. To prepare the inverse opals in a reproducible manner, we use a capillary wetting of opal templates by underlying polymer film above glass transition temperature. The opal template composed of monodisperse silica particles is formed on the film of biodegradable polymer, poly(lactic-coglycolic acid) (PLGA), by two steps of deposition: monolayer formation by spin coating and opal formation by dip coating; the spin coating is important for the succeed dip coating process as the dip coating requires hydrophilic substrate. The opals are embedded into the molten PLGA film at elevated temperature through capillary wetting of silica particles, which ceases when the top layer of the opal reaches the interface between air and the molten film. The composite film is solidified at room temperature, which is then subjected to selective etching of silica using hydrofluoric (HF) acid, finally resulting in the inverse opals made of PLGA. The inverse opals display a pronounced structural color. When the inverse opals are incubated in aqueous solution, they slowly lose structural colors as the Colloidal crystals and their derivatives possess photonic bandgap property, being useful in various applications, including structural coloration and colorimetric sensing. In this work, inverse opals made of a biodegradable polymer, poly(lactic-co-glycolic acid) (PLGA), are prepared to provide a controlled discolora...