Graphene Inkjet Integrated Intelligent Sensors and Systems

Increasing awareness of personal health conditions has emerged as a key driver in point-of-care breath analysis for early diagnosis. This also demands real-time monitoring of air pollution based on internet of things (IoT) networks. Both systems rely on the development of scalable mobile-embeddable devices. Conventional devices face challenges like high power consumption, severe baseline drifts, and cross-analyte interferences, compromising the detection accuracies. Recently, 2D nanomaterials and their functionalization with metal oxides (MOx) have become attractive for high performing sensors. Solution processing of these materials coupled with inkjet printing can be promising for fabricating low-cost devices. I have addressed the abovementioned challenges from the perspectives of materials, device fabrication, and algorithmic approaches. I develop an inkjet-printed array of graphene-ZnO and graphene-WO$_{3}$ system integrated onto miniaturized CMOS platforms to detect NH$_{3}$ and acetone for potential diagnosis of diseases. I also develop a machine-intelligent classification system based on inkjet-integrated $\alpha$-Fe$_{2}$O$_{3}$-rGO CMOS devices to selectively measure NO$_{2}$ air pollutants. The ink formulation and the theoretical model I develop facilitate uniform printed morphology, achieving excellent device reproducibility. Coupled with temperature modulation (TM) algorithms I develop, the devices achieve high responsivity, eliminated baseline drift, reduced response/recovery time, high SNR, and extraordinary repeatability. Moreover, a sensor array is established for compensation of cross-analyte interference. The influences of interferents are addressed by machine learning (ML) approaches. The predictive system quantifies NO$_{2}$ concentrations under different humidity conditions, with excellent separation between classes. Furthermore, the fully inkjet-printed room temperature NO$_{2}$ sensors assembled within the developed multi-sensory hub have performed reliable measurements in a real-world environment. My strategy to combine the sensing material, inkjet printing onto the CMOS platform, and TM/ML algorithms promises a robust system that outperforms conventional devices. The versatile technologies enable reliable multi-material array for potential multi-disease diagnostics. The systems developed also pave the way for ubiquitous implementation of adaptive wireless-connected monitoring systems

Methods for simultaneously identifying coherent local clusters with smooth global patterns in gene expression profiles

<p>Abstract</p> <p>Background</p> <p>The hierarchical clustering tree (HCT) with a dendrogram <abbrgrp><abbr bid="B1">1</abbr></abbrgrp> and the singular value decomposition (SVD) with a dimension-reduced representative map <abbrgrp><abbr bid="B2">2</abbr></abbrgrp> are popular methods for two-way sorting the gene-by-array matrix map employed in gene expression profiling. While HCT dendrograms tend to optimize local coherent clustering patterns, SVD leading eigenvectors usually identify better global grouping and transitional structures.</p> <p>Results</p> <p>This study proposes a flipping mechanism for a conventional agglomerative HCT using a rank-two ellipse (R2E, an improved SVD algorithm for sorting purpose) seriation by Chen <abbrgrp><abbr bid="B3">3</abbr></abbrgrp> as an external reference. While HCTs always produce permutations with good local behaviour, the rank-two ellipse seriation gives the best global grouping patterns and smooth transitional trends. The resulting algorithm automatically integrates the desirable properties of each method so that users have access to a clustering and visualization environment for gene expression profiles that preserves coherent local clusters and identifies global grouping trends.</p> <p>Conclusion</p> <p>We demonstrate, through four examples, that the proposed method not only possesses better numerical and statistical properties, it also provides more meaningful biomedical insights than other sorting algorithms. We suggest that sorted proximity matrices for genes and arrays, in addition to the gene-by-array expression matrix, can greatly aid in the search for comprehensive understanding of gene expression structures. Software for the proposed methods can be obtained at <url>http://gap.stat.sinica.edu.tw/Software/GAP</url>.</p

Endoscopic Balloon Dilatation for Esophageal Strictures in Children Younger Than 6 Years: Experience in a Medical Center

Esophageal strictures in children may be caused by congenital anomaly, caustic agent or foreign body ingestion, complication of reflux esophagitis, and after esophageal surgery. Accidental ingestion of alkaline fluid is the most common cause of corrosive esophagitis in children in Taiwan. In this article, we studied 10 pediatric patients who had esophageal strictures and required endoscopic balloon dilatation (EBD) therapy under general anesthesia from January 2003 to June 2009. The median age of the studied children who received their first EBD treatment was 36.2 months (13.4–60.9 months), with a dilator size of 8.0mm (5–12 mm). The interval between injury and initial EBD was 3.0 months (1.3–60.8 months). The treatment duration averaged 16.7 months (3.0–69.3 months), with 13.5 (4–31) instances of EBD therapy per patient. The greater the length of stricture, the more number of times EBD was needed. In these cases, no severe complication was found after the procedure. The result indicated that EBD under general anesthesia was a safe and effective method to resolve the symptom of dysphagia and diet condition. Because of the limited number of study cases, long-term studies are required to further confirm the clinical effect of EBD under general anesthesia

Lasing on nonlinear localized waves in curved geometry

The use of geometrical constraints opens many new perspectives in photonics and in fundamental studies of nonlinear waves. By implementing surface structures in vertical cavity surface emitting lasers as manifolds for curved space, we experimentally study the impacts of geometrical constraints on nonlinear wave localization. We observe localized waves pinned to the maximal curvature in an elliptical-ring, and confirm the reduction in the localization length of waves by measuring near and far field patterns, as well as the corresponding dispersion relation. Theoretically, analyses based on a dissipative model with a parabola curve give good agreement remarkably to experimental measurement on the transition from delocalized to localized waves. The introduction of curved geometry allows to control and design lasing modes in the nonlinear regime.Comment: 6 pages, 6 figure

Effects of Angelica dahurica

The main objective of wound treatments is to restore the functional skin properties and prevent infection. Traditional Chinese medicine provides alternative anti-inflammatory, antimicrobial, and wound healing therapies. Both Angelica dahurica extract (AE) and Rheum officinale extract (RE) possess antimicrobial activity. In this study, AE and RE were applied in wound treatment to investigate their healing effects. Thirty Sprague-Dawley rats with dorsal full-thickness skin excision were divided into normal saline (NS), AE, RE, AE plus RE (ARE), and Biomycin (BM) groups. The treatment and area measurement of wounds were applied daily for 21 days. Wound biopsies and blood samples were obtained for histology examinations and cytokine analysis. Results showed that wound contraction in ARE group was significantly higher than that in NS and BM groups (P 0.05), and plasma TGF-β1 levels were significantly lower than those in the NS group on days 3-4 (P < 0.05). In conclusion, ARE accelerates wound healing during inflammation and proliferation phases

Antioxidant activity and growth inhibition of human colon cancer cells by crude and purified fucoidan preparations extracted from Sargassum cristaefolium

AbstractFucose-containing sulfated polysaccharides, also termed “fucoidans”, which are known to possess antioxidant, anticoagulant, anticancer, antiviral, and immunomodulating properties, are normally isolated from brown algae via various extraction techniques. In the present study, two methods (SC1 and SC2) for isolation of fucoidan from Sargassum cristaefolium were compared, with regard to the extraction yields, antioxidant activity, and inhibition of growth of human colon cancer cells exhibited by the respective extracts. SC1 and SC2 differ in the number of extraction steps and concentration of ethanol used, as well as the obtained sulfated polysaccharide extracts, namely, crude fucoidan preparation (CFP) and purified fucoidan preparation (PFP), respectively. Thin layer chromatography, Fourier transform infrared analysis, and measurements of fucose and sulfate contents revealed that the extracts were fucoidan. There was a higher extraction yield for CFP, which contained less fucose and sulfate but more uronic acid, and had weaker antioxidant activity and inhibition of growth in human colon cancer cells. In contrast, there was a lower extraction yield for PFP, which contained more fucose and sulfate but less uronic acid, and had stronger antioxidant activity and inhibition of growth in human colon cancer cells. Thus, since the difference in bioactive activities between CFP and PFP was not remarkable, the high extraction yield of SC1 might be favored as a method in industrial usage for extracting fucoidan

Prevention and early management of carotid blowout syndrome for patients receiving head and neck salvage boron neutron capture therapy (BNCT)

Background/purpose The incidence rate of oral and pharyngeal cancers in Taiwan has increased gradually over the past few decades. The standard treatment strategy for oral and pharyngeal cancers includes surgery or radiotherapy, with concurrent chemotherapy in certain types of tumors. Unfortunately, in-field recurrence is sometimes inexorable. Furthermore, re-irradiation of the recurrence site may cause severe complications due to the tolerance of normal tissue to radiation therapy. One fatal complication is carotid blowout syndrome (CBS). Boron neutron capture therapy (BNCT) is a new modality of radiation therapy, which is also mentioned as targeted radiotherapy. It is a feasible treatment that has the potential to spare normal tissue from being damaged by irradiation while simultaneously treating the primary tumor. In this presentation, we will share our experience with BNCT in treating recurrent head and neck cancers, as well as the prevention and management of CBS. Materials and methods We evaluated 4 patients with head and neck cancers treated by BNCT in Taiwan. All patients had undergone surgery previously and had received postoperative concurrent chemoradiotherapy. Results The 4 patients in this study were diagnosed with head and neck malignancies. The median follow-up period after the first course of BNCT was 15.1 months. After BNCT, 2 patients developed impending CBS, and 1 of them died. The remaining 3 patients survived until the last date of follow-up. Conclusion Pre-BNCT carotid artery evaluation through computed tomography angiography and early intervention if necessary is crucial when treating patients with recurrent head and neck cancers by BNCT

High ambient-contrast-ratio display using tandem reflective liquid crystal display and organic light-emitting device

A high ambient-contrast-ratio (A-CR) and large aperture-ratio display is conceptually demonstrated and experimentally validated by stacking a normally black reflective liquid crystal display (NB-RLCD) and an organic light-emitting device (OLED). Such a tandem device can be switched between the NB-RLCD mode and the OLED mode under bright and dark ambient light, respectively. The normally black characteristic of the RLCD also helps to boost the A-CR under OLED-mode operation. To obtain a better image quality in the RLCD mode, a bumpy and transmissive structure is used to eliminate the specular reflection and to increase the viewing angle performance that results in CR \u3e 2:1 over 55 degrees viewing cone. Besides, such a structure can also increase the external quantum efficiency of the OLED by 49.4%. In our experiments, regardless of the ambient intensity the A-CR is kept higher than 100:1

Inkjet-printed CMOS-integrated graphene–metal oxide sensors for breath analysis

Abstract: Early diagnosis in exhaled breath is a key technology for next-generation personal healthcare monitoring. Current chemiresistive sensors, primarily based on metal oxide (MOx) thin films, have limited applicability in such portable systems due to their high power consumption, long recovery time, poor device-to-device consistency, and baseline drifts. To address these challenges for ammonia (NH3) detection in exhaled breath, a critical biomarker for a variety of kidney and liver problems, we present a formulation of a graphene–MOx functional ink-based sensing platform. We integrate our sensing layer directly onto miniaturized CMOS microhotplates (μHP) via inkjet printing, potentially enabling scalability and device-to-device performance repeatability. Using stage-by-stage temporal analysis, and a temperature-pulsed modulation (TM) strategy, we achieve ultrahigh responsivity (1500% at 10 ppm pure NH3), fast response and recovery time (28 and 43 s), ultralow power consumption (~6 mW), negligible baseline drift (<0.67%), excellent cross-device and cross-cycle consistency (<0.5% and <0.41% variation in responsivity) and long-term stability (<1% variation) in our graphene–zinc oxide (ZnO) formulation, outperforming conventional MOx chemiresistive sensors. We further mitigate the effect of humidity through our measurement protocols, while interference from acetone is compensated through the parallel deployment of an additional inkjet printed graphene–tungsten oxide (WO3) device as part of the sensor array. Our dual graphene–MOx formulations and their integration with ultralow power CMOS through inkjet printing represent a significant step towards reliable and portable multi-analyte breath diagnostics