Materials and processing of polymer-based electrochromic devices Wang, Hongfeng; Barrett, Matthew; Duane, Brett ...
Materials science & engineering. B, Solid-state materials for advanced technology,
February 2018, 2018-02-00, 20180201, Letnik:
228
Journal Article
Recenzirano
•State-of-the-art research activities on the materials and assembly techniques for polymer based electrochromic devices.•Roll to roll compatible processing methods such as spray coating are critical ...for large scale manufacturing.•Edge sealant and encapsulation methods are key issues for devices assembly for commercial applications.
The demand for polymer based electrochromic device is increasing in recent years due to not only the advantages of conjugated electrochromic polymers such as high color versatility, large optical contrasts, but also their potential applications in flexible devices. In this review, we focus on the state-of-the-art research activities related to the materials and assembly techniques developed for polymer based electrochromic devices. More specifically, we will give an overview of the whole fabrication process including transparent conductive substrate, processing of electrochromic polymer, electrolyte formulation, as well as edge sealant materials and possible encapsulation methods.
Changes in the human gastrointestinal microbiome are associated with several diseases. To infer causality, experiments in representative models are essential, but widely used animal models exhibit ...limitations. Here we present a modular, microfluidics-based model (HuMiX, human-microbial crosstalk), which allows co-culture of human and microbial cells under conditions representative of the gastrointestinal human-microbe interface. We demonstrate the ability of HuMiX to recapitulate in vivo transcriptional, metabolic and immunological responses in human intestinal epithelial cells following their co-culture with the commensal Lactobacillus rhamnosus GG (LGG) grown under anaerobic conditions. In addition, we show that the co-culture of human epithelial cells with the obligate anaerobe Bacteroides caccae and LGG results in a transcriptional response, which is distinct from that of a co-culture solely comprising LGG. HuMiX facilitates investigations of host-microbe molecular interactions and provides insights into a range of fundamental research questions linking the gastrointestinal microbiome to human health and disease.
To compile a list of genes that have been reported to be affected by external ionizing radiation (IR) and to assess their performance as candidate biomarkers for individual human radiation dosimetry.
...Eligible studies were identified through extensive searches of the online databases from 1978 to 2017. Original English-language publications of microarray studies assessing radiation-induced changes in gene expression levels in human blood after external IR were included. Genes identified in at least half of the selected studies were retained for bio-statistical analysis in order to evaluate their diagnostic ability.
24 studies met the criteria and were included in this study. Radiation-induced expression of 10,170 unique genes was identified and the 31 genes that have been identified in at least 50% of studies (12/24 studies) were selected for diagnostic power analysis. Twenty-seven genes showed a significant Spearman's correlation with radiation dose. Individually, TNFSF4, FDXR, MYC, ZMAT3 and GADD45A provided the best discrimination of radiation dose < 2 Gy and dose ≥ 2 Gy according to according to their maximized Youden's index (0.67, 0.55, 0.55, 0.55 and 0.53 respectively). Moreover, 12 combinations of three genes display an area under the Receiver Operating Curve (ROC) curve (AUC) = 1 reinforcing the concept of biomarker combinations instead of looking for an ideal and unique biomarker.
Gene expression is a promising approach for radiation dosimetry assessment. A list of robust candidate biomarkers has been identified from analysis of the studies published to date, confirming for example the potential of well-known genes such as FDXR and TNFSF4 or highlighting other promising gene such as ZMAT3. However, heterogeneity in protocols and analysis methods will require additional studies to confirm these results.
The decellularization of plant-based biomaterials to generate tissue-engineered substitutes or in vitro cellular models has significantly increased in recent years. These vegetal tissues can be ...sourced from plant leaves and stems or fruits and vegetables, making them a low-cost, accessible, and sustainable resource from which to generate three-dimensional scaffolds. Each construct is distinct, representing a wide range of architectural and mechanical properties as well as innate vasculature networks. Based on the rapid rise in interest, this review aims to detail the current state of the art and presents the future challenges and perspectives of these unique biomaterials. First, we consider the different existing decellularization techniques, including chemical, detergent-free, enzymatic, and supercritical fluid approaches that are used to generate such scaffolds and examine how these protocols can be selected based on plant cellularity. We next examine strategies for cell seeding onto the plant-derived constructs and the importance of the different functionalization methods used to assist in cell adhesion and promote cell viability. Finally, we discuss how their structural features, such as inherent vasculature, porosity, morphology, and mechanical properties (i.e., stiffness, elasticity, etc.) position plant-based scaffolds as a unique biomaterial and drive their use for specific downstream applications. The main challenges in the field are presented throughout the discussion, and future directions are proposed to help improve the development and use of vegetal constructs in biomedical research.
The use of plant-based biomaterials for tissue engineering has recently generated interest as plant decellularization produces biocompatible scaffolds which can be repopulated with human cells. The ...predominant approach for vegetal decellularization remains serial chemical processing. However, this technique is time-consuming and requires harsh compounds which damage the resulting scaffolds. The current study presents an alternative solution using supercritical carbon dioxide (scCO
). Protocols testing various solvents were assessed and results found that scCO
in combination with 2% peracetic acid decellularized plant material in less than 4 h, while preserving plant microarchitecture and branching vascular network. The biophysical and biochemical cues of the scCO
decellularized spinach leaf scaffolds were then compared to chemically generated scaffolds. Data showed that the scaffolds had a similar Young's modulus, suggesting identical stiffness, and revealed that they contained the same elements, yet displayed disparate biochemical signatures as assessed by Fourier-transform infrared spectroscopy (FTIR). Finally, human fibroblast cells seeded on the spinach leaf surface were attached and alive after 14 days, demonstrating the biocompatibility of the scCO
decellularized scaffolds. Thus, scCO
was found to be an efficient method for plant material decellularization, scaffold structure preservation and recellularization with human cells, while performed in less time (36 h) than the standard chemical approach (170 h).
Abstract The human microbiome is the collection of microorganisms in the body that exist in a mutualistic relationship with the host. Recent studies indicate that perturbations in the microbiome may ...be implicated in a number of diseases, including cancer. More specifically, changes in the gut and vaginal microbiomes may be associated with a variety of gynecologic cancers, including cervical cancer, uterine cancer, and ovarian cancer. Current research and gaps in knowledge regarding the association between the gut and vaginal microbiomes and the development, progression, and treatment of gynecologic cancers are reviewed here. In addition, the potential use of probiotics to manage symptoms of these gynecologic cancers is discussed. A better understanding of how the microbiome composition is altered at these sites and its interaction with the host may aid in prevention, optimization of current therapies, development of new therapeutic agents and/or dosing regimens, and possibly limit the side effects associated with cancer treatment.
Currently, the standard method for identifying biological agents of potential threats to national security and public health, such as pathogens, virus, and toxins, mainly rely on microbiological ...cultivation. This method is time-consuming and it requires sophisticated equipment and well-trained personnel, which are often unavailable in remote areas or at point-of-need. Therefore, an alternative rapid, simple, and sensitive method for detecting bio-threat agents is in crucial need. We report a paper-based Vertical Flow Immunoassay (VFI) device that can overcome these limitations. The VFI device utilizes a nanoporous nitrocellulose membrane encapsulated in a stainless steel filter holder. As the sample is pushed through the membrane, which is pre-functionalized with capture antibody, a sandwich assay is formed and colorimetric signal is generated to reflect the presence of target antigens. Through theoretical analyses of antigen-antibody binding process inside a porous membrane, we identified two critical factors – membrane pore size and sample flow rate that can be optimized to improve the assay sensitivity. Then, the effects were demonstrated through experimental studies using Burkholderia pseudomallei (the causative agent of melioidosis) as a model pathogen. The B. pseudomallei VFI was based on an immunoassay targeting the B. pseudomallei surface capsular polysaccharide (CPS). The experimental results agreed well with the theory showing that increasing the flow speed (up to 1.06 mm/s) and reducing the membrane pore size (down to 0.1 µm) could improve the sensitivity by at least 5 times. The VFI's limit-of-detection for CPS spiked in buffer solution was determined to be 0.02 ng/mL. The developed VFI shows great potential as a point-of-care tool for detection of bio-threat agents in a variety of clinical and resource-restricted conditions.
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•Paper-based vertical flow device was developed to detect bio-threat pathogens.•Limit-of-detection for B. pseudomallei surface capsular polysaccharide was 0.02 ng/mL.•Sample flow rate and membrane pore size was studied in theory and experiment.•Multiplexing diagnostic of melioidosis and anthrax was demonstrated.
We report a shipping container that enables a disruptive logistics for cytogenetic biodosimetry for radiation countermeasures through pre-processing cell culture during transportation. The container ...showed precise temperature control (< 0.01 °C) with uniform sample temperature (< 0.1 °C) to meet the biodosimetry assay requirements. Using an existing insulated shipping box and long shelf life alkaline batteries makes it ideal for national stockpile. Dose curve of cytogenetic biodosimetry assay using the shipping container showed clear dose response and high linear correlation with the control dose curve using a laboratory incubator (Pearson's correlation coefficient: 0.992). The container's ability of pre-processing biological samples during transportation could have a significant impact on radiation countermeasure, as well as potential impacts in other applications such as biobanking, novel molecular or cell-based assays or therapies.
A high porosity micropore arrayed parylene membrane is a promising device that is used to capture circulating and exfoliated tumor cells (CTCs and ETCs) for liquid biopsy applications. However, its ...fabrication still requires either expensive equipment or an expensive process. Here, we report on the fabrication of high porosity (>40%) micropore arrayed parylene membranes through a simple reactive ion etching (RIE) that uses photoresist as the etching mask. Vertical sidewalls were observed in etched parylene pores despite the sloped photoresist mask sidewalls, which was found to be due to the simultaneous high DC-bias RIE induced photoresist melting and substrate pedestal formation. A theoretical model has been derived to illustrate the dependence of the maximum membrane thickness on the final pore-to-pore spacing, and it is consistent with the experimental data. A simple, yet accurate, low number (<50) cell counting method was demonstrated through counting cells directly inside a pipette tip under phase-contrast microscope. Membranes as thin as 3 μm showed utility for low number tumor cell capture, with an efficiency of 87-92%.
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