Two-staged guillotine cut,two-dimensional bin packing optimisation with flexible bin size for steel mother plate design

This paper looks into the steel mother plate design problem. A slab, which is an intermediate work in process, is subsequently rolled into a mother plate with the specific dimensions of thickness, length, and width. The mother plate is then cut into customer order plates. As a slab is rolled into a mother plate through a series of horizontal and vertical rolling processes, different-sized mother plates can be generated from a single-slab type. This flexibility allows for the size of a mother plate to be determined according to the order plates assigned to it. Furthermore, when the order plates are cut from a mother plate, a guillotine cut is required to reduce the production cost. The steel mother plate design problem involves the placing of order plates on the mother plates in a guillotine cut pattern and determining the sizes of the mother plates with the objective of minimising the number of slabs; thus it may be considered as a two-staged guillotine cut, two-dimensional bin packing problem with flexible bin size. This paper introduces the problem, presents several mathematical models, and proposes an iterative two-phase heuristic method consisting of several algorithms to solve the problem. Computational results for the benchmark problems show the effectiveness of the proposed method.     

Integrity and cell-monolayer permeability of chitosan nanoparticles in simulated gastrointestinal fluids

The objective of this study was to assess the integrity and intestinal permeability of chitosan nanoparticles (CNPs) in simulated gastrointestinal fluids (SGIF). The cell-associated and transported chitosan was quantified and visualized after incubation of the CNPs with Caco-2 cell monolayer with/without SGIF treatment. In order to establish the role of proteins in the SGIF, CNPs were incubated with 4 proteins having different isoelectric points (pI). CNPs incubated with the fluids did not attach to the cell monolayer in contrast to the intact CNPs. Negatively-charged protein formed the complex with CNPs leading to particle size increase, but protected CNPs from disintegration. In contrary, positively-charged protein interacted with cross-linker causing disintegration of CNPs. CNPs incubated with the fluids did not attach to the cell monolayer in contrast to the intact CNPs. The results suggested that the surface charges of CNPs and proteins play a critical role in structural changes of CNPs in biological environment.     

Chemosensors for pyrophosphate

The selective detection of the anion pyrophosphate (PPi) is a major research focus. PPi is a biologically important target because it is the product of ATP hydrolysis under cellular conditions, and because it is involved in DNA replication catalyzed by DNA polymerase, its detection is being investigated as a real-time DNA sequencing method. In addition, within the past decade, the ability to detect PPi has become important in cancer research. In general, the sensing of anions in aqueous solution requires a strong affinity for anions in water as well as the ability to convert anion recognition into a fluorescent or colorimetric signal. Among the variety of methods for detecting PPi, fluorescent chemosensors and colorimetric sensors for PPi have attracted considerable attention during the past 10 years. Compared with the recognition of metal ions, it is much more challenging to selectively recognize anions in an aqueous system due to the strong hydration effects of anions. Consequently, the design of PPi sensors requires the following: an understanding of the molecular recognition between PPi and the binding sites, the desired solubility in aqueous solutions, the communicating and signaling mechanism, and most importantly, selectivity for PPi over other anions such as AMP and ADP, and particularly phosphate and ATP. This Account classifies chemosensors for PPi according to topological and structural characteristics. Types of chemosensors investigated and reported in this study include those that contain metal ion complexes, metal complexes combined with excimers, those that function with a displacement approach, and those based on hydrogen-bonding interaction. Thus far, the utilization of a metal ion complex as a binding site for PPi has been the most successful strategy. The strong binding affinity between metal ions and PPi allows the detection of PPi in a 100% aqueous solution. We have demonstrated that carefully designed receptors can distinguish between PPi and ATP based on their different total anionic charge densities. We have also demonstrated that a PPi metal ion complex sensor has a bioanalytical application. This sensor can be used in a simple and quick, one-step, homogeneous phase detection method in order to confirm DNA amplification after polymerase chain reaction (PCR).     

Activatable Photosensitizers: Agents for Selective Photodynamic Therapy

Recent developments in the design of bifunctional and activatable photosensitizers rejuvenate the aging field of photodynamic sensitization and photodynamic therapy. While systematic studies have uncovered new dyes that can serve as potential photosensitizers, the most promising results have come from studies aimed at gaining precise control over the location and rate of cytotoxic singlet oxygen generation. As a consequence, higher selectivities and efficiencies in photodynamic treatment protocols are now within reach. This feature article highlights the variety of approaches that have been pursued to improve photodynamic therapy and to transform simple photosensitizers into smarter theranostic agents.     

Cancer‐Associated,Stimuli‐Driven,Turn on Theranostics for Multimodality Imaging and Therapy

Advances in bioinformatics, genomics, proteomics, and metabolomics have facilitated the development of novel anticancer agents that have decreased side effects and increased safety. Theranostics, systems that have combined therapeutic effects and diagnostic capabilities, have garnered increasing attention recently because of their potential use in personalized medicine, including cancer‐targeting treatments for patients. One interesting approach to achieving this potential involves the development of cancer‐associated, stimuli‐driven, turn on theranostics. Multicomponent constructs of this type would have the capability of selectively delivering therapeutic reagents into cancer cells or tumor tissues while simultaneously generating unique signals that can be readily monitored under both in vitro and in vivo conditions. Specifically, their combined anticancer activities and selective visual signal respond to cancer‐associated stimuli, would make these theranostic agents more highly efficient and specific for cancer treatment and diagnosis. This article focuses on the progress of stimuli‐responsive turn on theranostics that activate diagnostic signals and release therapeutic reagents in response to the cancer‐associated stimuli. The present article not only provides the fundamental backgrounds of diagnostic and therapeutic tools that have been widely utilized for developing theranostic agents, but also discusses the current approaches for developing stimuli‐responsive turn on theranostics.     

NapWell: An EOG-based Sleep Assistant Exploring the Effects of Virtual Reality on Sleep Onset

Virtual Reality - We present NapWell, a Sleep Assistant using virtual reality (VR) to decrease sleep onset latency by providing a realistic imagery distraction prior to sleep onset. Our proposed...     

A data-driven generic simulation model for logistics-embedded assembly manufacturing lines

Simulation has been used to evaluate various aspects of manufacturing systems. However, building a simulation model of a manufacturing system is time-consuming and error-prone because of the complexity of the systems. This paper introduces a generic simulation modeling framework to reduce the simulation model build time. The framework consists of layout modeling software and a data-driven generic simulation model. The generic simulation model was developed considering the processing as well as the logistics aspects of assembly manufacturing systems. The framework can be used to quickly develop an integrated simulation model of the production schedule, operation processes and logistics of a system. The framework was validated by developing simulation models of cellular and conveyor manufacturing systems.     

Colloidal Photonic Crystal Strain Sensor Integrated with Deformable Graphene Phototransducer

Flexible, architectured, photonic nanostructures such as colloidal photonic crystals (CPCs) can serve as colorimetric strain sensors, where external applied strain leads to a noticeable color change. However, CPCs' response to strain is difficult to quantify without the use of optical spectroscopy. Integration of flexible electrical readout of CPCs' color change is a challenge due to a lack of flexible/stretchable electrical transducers. This work details a colorimetric strain sensor with optoelectrical quantification based on an integrated system of CPCs over a crumpled graphene phototransducer, which optoelectrically quantifies CPCs, response to strain. The hybrid system enables direct visual perception of strain, while strain quantification via electrical measurement of the hybrid system outperforms that of crumpled graphene strain sensors by more than 100 times. The unique combination of a photonic sensing element with a deformable transducer will allow for the development of novel, electrically quantifiable colorimetric sensors with high sensitivity.     

Enhanced efficiency of organic photovoltaic cells with Sr2SiO4:Eu2+ and SrGa2S4:Eu2+ phosphors

We report the effect of yellow Sr₂SiO₄:Eu²⁺ and green SrGa₂S₄:Eu²⁺ phosphors on the efficiency of organic photovoltaic (OPV) cells. Each phosphor was coated on the back side of indium tin oxide (ITO)/glass substrates by spin coating with poly(methyl methacrylate) (PMMA). The maximum absorption wavelength of the active layer in the OPV cells was ～512 nm. The emission peaks of Sr₂SiO₄:Eu²⁺ and SrGa₂S₄:Eu²⁺ were maximized at 552 nm and 534 nm, respectively. The short circuit current density (J_sc) and power conversion efficiency (PCE) of the OPV cells with Sr₂SiO₄:Eu²⁺ (8.55 mA/cm² and 3.25%) and with SrGa₂S₄:Eu²⁺ (9.29 mA/cm² and 3.3%) were higher than those of the control device without phosphor (7.605 mA/cm² and 3.04%). We concluded that phosphor tuned the wavelength of the incident light to the absorption wavelength of the active layer, thus increasing the J_sc and PCE of the OPV cells.