Printable and Rewritable Full Block Copolymer Structural Color

Structural colors (SCs) of photonic crystals (PCs) arise from selective constructive interference of incident light. Here, an ink‐jet printable and rewritable block copolymer (BCP) SC display is demonstrated, which can be quickly written and erased over 50 times with resolution nearly equivalent to that obtained with a commercial office ink‐jet printer. Moreover, the writing process employs an easily modified printer for position‐ and concentration‐controlled deposition of a single, colorless, water‐based ink containing a reversible crosslinking agent, ammonium persulfate. Deposition of the ink onto a self‐assembled BCP PC film comprising a 1D stack of alternating layers enables differential swelling of the written BCP film and produces a full‐colored SC display of characters and images. Furthermore, the information can be readily erased and the system can be reset by application of hydrogen bromide. Subsequently, new information can be rewritten, resulting in a chemically rewritable BCP SC display.     

Exploiting Colloidal Metamaterials for Achieving Unnatural Optical Refractions

The scaling down of meta-atoms or metamolecules (collectively denoted as metaunits) is a long-lasting issue from the time when the concept of metamaterials was first suggested. According to the effective medium theory, which is the foundational concept of metamaterials, the structural sizes of meta-units should be much smaller than the working wavelengths (e.g., << 1/5 wavelength). At relatively low frequency regimes (e.g., microwave and terahertz), the conventional monolithic lithography can readily address the materialization of metamaterials. However, it is still challenging to fabricate optical metamaterials (metamaterials working at optical frequencies such as the visible and near-infrared regimes) through the lithographic approaches. This serves as the rationale for using colloidal self-assembly as a strategy for the realization of optical metamaterials. Colloidal self-assembly can address various critical issues associated with the materialization of optical metamaterials, such as achieving nanogaps over a large area, increasing true 3D structural complexities, and cost-effective processing, which all are difficult to attain through monolithic lithography. Nevertheless, colloidal self-assembly is still a toolset underutilized by optical engineers. Here, the design principle of the colloidally self-assembled optical metamaterials exhibiting unnatural refractions, the practical challenge of relevant experiments, and the future opportunities are critically reviewed.     

Cuproptosis-Inducible Chemotherapeutic/Cascade Catalytic Reactor System for Combating with Breast Cancer

Cascade hydroxyl radical generating hydrogel reactor structures including a chemotherapeutic agent are invented for multiple treatment of breast cancer. Glucose oxidase (GOx) and cupric sulfate (Cu) are introduced for transforming accumulated glucose (in cancer cells) to hydroxyl radicals for starvation/chemodynamic therapy. Cu may also suppress cancer cell growth via cuproptosis-mediated cell death. Berberine hydrochloride (BER) is engaged as a chemotherapeutic agent in the hydrogel reactor for combining with starvation/chemodynamic/cuproptosis therapeutic modalities. Moreover, Cu is participated as a gel crosslinker by coordinating with catechol groups in hyaluronic acid-dopamine (HD) polymer. Controlling viscoelasticity of hydrogel reactor can extend the retention time following local injection and provide sustained drug release patterns. Low biodegradation rate of designed HD/BER/GOx/Cu hydrogel can reduce dosing frequency in local cancer therapy and avoid invasiveness-related inconveniences. Especially, it is anticipated that HD/BER/GOx/Cu hydrogel system can be applied for reducing size of breast cancer prior to surgery as well as tumor growth suppression in clinical application.     

Admissibility and stabilization of singular continuous 2D systems described by Roesser model

Multidimensional Systems and Signal Processing - The paper considers first, the admissibility conditions for continuous 2D systems represented by Roesser model by dealing with non-strict LMIs....     

Towards Media Inter-cloud Standardization – Evaluating Impact of Cloud Storage Heterogeneity

Digital media has been increasing very rapidly, resulting in cloud computing’s popularity gain. Cloud computing provides ease of management of large amount of data and resources. With a lot of devices communicating over the Internet and with the rapidly increasing user demands, solitary clouds have to communicate to other clouds to fulfill the demands and discover services elsewhere. This scenario is called inter-cloud computing or cloud federation. Inter-cloud computing still lacks standard architecture. Prior works discuss some of the architectural blue-prints, but none of them highlight the key issues involved and their impact, so that a valid and reliable architecture could be envisioned. In this paper, we discuss the importance of inter-cloud computing and present in detail its architectural components. Inter-cloud computing also involves some issues. We discuss key issues as well and present impact of storage heterogeneity. We have evaluated some of the most noteworthy cloud storage services, namely: Dropbox, Amazon CloudDrive, GoogleDrive, Microsoft OneDrive (formerly SkyDrive), Box, and SugarSync in terms of Quality of Experience (QoE), Quality of Service (QoS), and storage space efficiency. Discussion on the results shows the acceptability level of these storage services and the shortcomings in their design.     

The optical characteristics in the layers of Compact Disc-Recordable

The optical characteristics of the laser beam in the layers of Compact Disc Recordable (CD-R) has been studied. The optical disk which is compatible with currently used CD-drive consists of transparent polycarbonate (PC) substrate, organic dye recording layer, reflective gold layer, and ultra-violet (UV) cured protecting layer. For proper design of the layer structure, modeling of the optical characteristics in each layer is necessary. The reflection and local absorption of the laser beam energy in the layers of the disk were numerically calculated. The reflection of the disk oscillates with the thickness of dye layer due to the interference in the multilayers. The oscillation magnitude and period depend on the complex refractive index of the material. The energy absorption profile in the recording layer is dependent on the thickness of the layer.     

Crack-tip constraints of through-wall cracked pipes and its similarity to curved wide plates

In the present study, the effects of pipe geometries, material properties and loading conditions on crack-tip constraints of pipes with circumferential Through-wall crack (TWC) were investigated via systematic 3-dimensional (3-D) Finite element (FE) analyses. The crack-tip constraints were quantified by Q-stress, and to characterize the elastic-plastic strain hardening material behavior, Ramberg-Osgood (R-O) material was employed. Based on the FE results, it was observed that crack-tip constraints of pipes with TWC were dependent on crack length and thickness of pipe, however, the effects of each variables decreased as either thickness of pipe becomes thinner or crack length becomes longer. Moreover, the effects loading modes on Q-stresses for thin-walled pipes with TWC are negligible. Finally, the present Q-stresses of pipes were compared with those of Curved wide plate (CWP) in tension to address the similarity of crack-tip constraints between pipe and CWP, which could be used to produce the CWP to measure the fracture toughness of pipes accurately.     

Effect of Molecular Weight of Poly(Ethylene Glycol) Dicarboxylate on the Properties of Cross-Linked Hydrogel Film as an Antiadhesion Barrier

Poly(ethylene glycol) dicarboxylate (PEGDC)/poly(ethylene oxide) (PEO) cross-linked hydrogel films were developed as an antiadhesion barrier using an e-beam. The effects of molecular weight of PEGDC on hydrogel properties were investigated. The decrease in molecular weight of PEGDC increased the gel fraction and tissue adhesion, whereas the mechanical strength did not change considerably. On the other hand, the swelling ratio decreased rapidly with decreasing molecular weight of PEGDC. The cytotoxicity of PEGDC (2000 or 3000) was low, whereas that of PEGDC (1000) was higher. In animal studies, all hydrogels showed a better antiadhesive effect compared to the control.     

Rod-Like Structure of Cotton Cellulose/Polyvinyl Alcohol/Tellurium Dioxide (TeO2) Hybrid Nanocomposite and Antimicrobial Properties

We report on the in situ synthesis through sol-gel processing of a tellurium dioxide (TeO₂)–cellulose–polyvinyl alcohol (PVA) hybrid composite. The cellulose–PVA hybrid composite was synthesized through chemical graft in the presence of aqueous sodium hydroxide. Field emission scanning electron microscopy, SEM-EDX, high-resolution transition microscopy (FE-TEM) revealed that polycrystalline nanorods were uniformly distributed with sizes of 20?nm in the cotton cellulose–PVA–TeO₂ hybrid nanocomposite. The average size of TeO₂ crystallite was calculated to be 0.292?nm, as shown in the FE-TEM, SAED, and X-ray diffraction analysis. Furthermore, the hybrid nanocomposites were studied for their antimicrobial activity against Bacillus cereus and Escherichia coli strains, which was inhibited at a size of 10–12?mm after 24?h of incubation.     

Magnetic sensitivity enhanced novel fluorescent magnetic silica nanoparticles for biomedical applications

We synthesized novel fluorescent magnetic silica nanoparticles (FMSNPs) containing large magnetic components for biomedical application. By employing assemblies of magnetic nanoparticles as kernels against FMSNPs, both the saturation of magnetization and the magnetic resonance (MR) signal intensity were significantly enhanced. Furthermore, the cellular binding of FMSNPs was improved by introducing a positive charge on the surface of the FMSNPs, and fluorescent dyes on the surface of FMSNPs enable optical imaging of sub-cellular regions.